Showing papers by "Churchill Hospital published in 2003"

Insulin granule dynamics in pancreatic beta cells

Abstract: Glucose-induced insulin secretion in response to a step increase in blood glucose concentrations follows a biphasic time course consisting of a rapid and transient first phase followed by a slowly developing and sustained second phase. Because Type 2 diabetes involves defects of insulin secretion, manifested as a loss of first phase and a reduction of second phase, it is important to understand the cellular mechanisms underlying biphasic insulin secretion. Insulin release involves the packaging of insulin in small (diameter ≈0.3 µm) secretory granules, the trafficking of these granules to the plasma membrane, the exocytotic fusion of the granules with the plasma membrane and eventually the retrieval of the secreted membranes by endocytosis. Until recently, studies on insulin secretion have been confined to the appearance of insulin in the extracellular space and the cellular events preceding exocytosis have been inaccessible to more detailed analysis. Evidence from a variety of secretory tissues, including pancreatic islet cells suggests, however, that the secretory granules can be functionally divided into distinct pools that are distinguished by their release competence and/or proximity to the plasma membrane. The introduction of fluorescent proteins that can be targeted to the secretory granules, in combination with the advent of new techniques that allow real-time imaging of granule trafficking in living cells (granule dynamics), has led to an explosion of our knowledge of the pre-exocytotic and post-exocytotic processes in the beta cell. Here we discuss these observations in relation to previous functional and ultra-structural data as well as the secretory defects of Type 2 diabetes.

Itch: scratching more than the surface.

Abstract: In origin, itch can be cutaneous ("pruritoceptive", e.g. dermatitis), neuropathic (e.g. multiple sclerosis), neurogenic (e.g. cholestasis), mixed (e.g. uraemia) or psychogenic. Although itch of cutaneous origin shares a common neural pathway with pain, the afferent C-fibres subserving this type of itch are a functionally distinct subset: they respond to histamine, acetylcholine and other pruritogens, but are insensitive to mechanical stimuli. Histamine is the main mediator for itch in insect bite reactions and in most forms of urticaria, and in these circumstances the itch responds well to H(1)-antihistamines. However, in most dermatoses and in systemic disease, low-sedative H(1)-antihistamines are ineffective. Opioid antagonists relieve itch caused by spinal opioids, cholestasis and, possibly, uraemia. Ondansetron relieves itch caused by spinal opioids (but not cholestasis and uraemia). Other drug treatments for itch include rifampicin, colestyramine and 17-alpha alkyl androgens (cholestasis), thalidomide (uraemia), cimetidine and corticosteroids (Hodgkin's lymphoma), paroxetine (paraneoplastic itch), aspirin and paroxetine (polycythaemia vera) and indometacin (some HIV+ patients). If the remedies specified fail, paroxetine and mirtazapine should be considered. Ultraviolet B therapy, particularly narrow-band UVB, may be superior to drug treatment for itch in uraemia.

Loss of kindlin-1, a human homolog of the Caenorhabditis elegans actin-extracellular-matrix linker protein UNC-112, causes Kindler syndrome

Abstract: Kindler syndrome is an autosomal recessive disorder characterized by neonatal blistering, sun sensitivity, atrophy, abnormal pigmentation, and fragility of the skin. Linkage and homozygosity analysis in an isolated Panamanian cohort and in additional inbred families mapped the gene to 20p12.3. Loss-of-function mutations were identified in the FLJ20116 gene (renamed “KIND1” [encoding kindlin-1]). Kindlin-1 is a human homolog of the Caenorhabditis elegans protein UNC-112, a membrane-associated structural/signaling protein that has been implicated in linking the actin cytoskeleton to the extracellular matrix (ECM). Thus, Kindler syndrome is, to our knowledge, the first skin fragility disorder caused by a defect in actin-ECM linkage, rather than keratin-ECM linkage.

BTS guidelines for the management of pleural infection

Abstract: These guidelines have been replaced by BTS Pleural Disease Guideline 2010 Superseded By BTS Pleural Disease Guideline 2010: BTS Guidelines for the Management of Pleural Disease. Thorax 2003 May; 58(Suppl 2): 1–59.

BTS guidelines for the investigation of a unilateral pleural effusion in adults.

Abstract: These guidelines have been replaced by BTS Pleural Disease Guideline 2010 Superseded By BTS Pleural Disease Guideline 2010: BTS Guidelines for the Management of Pleural Disease. Thorax 2003 May; 58(Suppl 2): 1–59.

Consensus perspectives on prophylactic therapy for haemophilia: summary statement.

Abstract: Participants in an international conference on prophylactic therapy for severe haemophilia developed a consensus summary of the findings and conclusions of the conference. In the consensus, participants agreed upon revised definitions for primary and secondary prophylaxis and also made recommendations concerning the need for an international system of pharmacovigilance. Considerations on starting prophylaxis, monitoring outcomes, and individualizing treatment regimens were discussed. Several research questions were identified as needing further investigation, including when to start and when to stop prophylaxis, optimal dosing and dose interval, and methods for assessment of long-term treatment effects. Such studies should include carefully defined cohorts, validated orthopaedic and quality-of-life assessment instruments, and cost-benefit analyses.

Angiogenesis in endocrine tumors.

Abstract: Angiogenesis is the process of new blood vessel development from preexisting vasculature. Although vascular endothelium is usually quiescent in the adult, active angiogenesis has been shown to be an important process for new vessel formation, tumor growth, progression, and spread. The angiogenic phenotype depends on the balance of proangiogenic growth factors such as vascular endothelial growth factor (VEGF) and inhibitors, as well as interactions with the extracellular matrix, allowing for endothelial migration. Endocrine glands are typically vascular organs, and their blood supply is essential for normal function and tight control of hormone feedback loops. In addition to metabolic factors such as hypoxia, the process of angiogenesis is also regulated by hormonal changes such as increased estrogen, IGF-I, and TSH levels. By measuring microvascular density, differences in angiogenesis have been related to differences in tumor behavior, and similar techniques have been applied to both benign and malignant endocrine tumors with the aim of identification of tumors that subsequently behave in an aggressive fashion. In contrast to other tumor types, pituitary tumors are less vascular than normal pituitary tissue, although the mechanism for this observation is not known. A relationship between angiogenesis and tumor size, tumor invasiveness, and aggressiveness has been shown in some pituitary tumor types, but not in others. There are few reports on the role of microvascular density or angiogenic factors in adrenal tumors. The mechanism of the vascular tumors, which include adrenomedullary tumors, found in patients with Von Hippel Lindau disease has been well characterized, and clinical trials of antiangiogenic therapy are currently being performed in patients with Von Hippel Lindau disease. Thyroid tumors are more vascular than normal thyroid tissue, and there is a clear correlation between increased VEGF expression and more aggressive thyroid tumor behavior and metastasis. Although parathyroid tissue induces angiogenesis when autotransplanted and PTH regulates both VEGF and MMP expression, there are few studies of angiogenesis and angiogenic factors in parathyroid tumors. An understanding of the balance of angiogenesis in these vascular tumors and mechanisms of vascular control may assist in therapeutic decisions and allow appropriately targeted treatment.

Prior short-term consumption of resistant starch enhances postprandial insulin sensitivity in healthy subjects.

Abstract: Diets rich in insoluble-fibre are linked to a reduced risk of both diabetes and cardiovascular disease; however, the mechanism of action remains unclear. The aim of this study was to assess whether acute changes in the insoluble-fibre (resistant starch) content of the diet would have effects on postprandial carbohydrate and lipid handling. Ten healthy subjects consumed two identical, low-residue diets on separate occasions for 24 h (33% fat; <2 g dietary fibre). Of the diets one was supplemented with 60 g resistant starch (Novelose 260). On the following morning a fibre-free meal tolerance test (MTT) was carried out (59 g carbohydrate; 21 g fat; 2.1 kJ) and postprandial insulin sensitivity (SIORAL) assessed using a minimal model approach. Prior resistant starch consumption led to lower postprandial plasma glucose (p=0.037) and insulin (p=0.038) with a higher insulin sensitivity(44±7.5 vs 26±3.5×10−4 dl kg−1 min−1 per µUml−1; p=0.028) and C-peptide-to-insulin molar ratio (18.7±6.5 vs 9.7±0.69; p=0.017). There was no effect of resistant starch consumption on plasma triacylglycerol although non-esterified fatty acid and 3-hydroxybutyrate levels were suppressed 5 h after the meal tolerance test. Prior acute consumption of a high-dose of resistant starch enhanced carbohydrate handling in the postprandial period the following day potentially due to the increased rate of colonic fermentation.

Asymptomatic carriage of Pneumocystis jiroveci in subjects undergoing bronchoscopy: a prospective study

Abstract: Background: The opportunistic fungus Pneumocystis jiroveci is a common cause of respiratory infection in immunocompromised patients. By contrast, pneumocystis pneumonia (PCP) occurs only rarely in immunocompetent individuals. Asymptomatic colonisation with P jiroveci has recently been described in patients who are either minimally immunosuppressed or who have underlying lung disorders such as bronchiectasis. We sought to determine the prevalence of asymptomatic colonisation by P jiroveci in a cohort of adult patients undergoing diagnostic bronchoscopy. Methods: A prospective observational cohort study was performed in patients who required bronchoscopy and bronchoalveolar lavage (BAL) as part of their routine clinical assessment. All the samples underwent standard microbiological analysis and a Grocott methenamine silver stain was performed where clinically indicated to detect the presence of P jiroveci. Polymerase chain reaction for detection of P jiroveci specific DNA was also performed. Results: Ninety three consecutive BAL fluid samples were analysed, 17 (18%) of which contained P jiroveci DNA. Of the potential predictors examined, only glucocorticoid use was significantly associated with detectable P jiroveci DNA. Eighteen patients were receiving oral glucocorticoids (equivalent to >20 mg/day prednisolone) at the time of bronchoscopy, of whom eight (44%) had detectable P jiroveci DNA. In contrast, P jiroveci was detected in only nine of 75 patients (12%) who were not receiving glucocorticoids (difference between proportions 32%, 95% CI 8 to 57; p=0.004, two tailed Fisher's exact test). Conclusions: P jiroveci colonisation, as determined by detection of P jiroveci DNA in BAL fluid, is common in HIV negative patients with primary respiratory disorders undergoing bronchoscopy and BAL. The higher prevalence in patients receiving corticosteroids suggests that oral glucocorticoid therapy is an independent risk factor for colonisation. In contrast, underlying lung cancer or COPD did not appear to be risk factors.

Radiation-therapy effects on bone density.

Abstract: Only limited data are available on the effects of radiation-therapy on the mineral content of the bone of children treated for malignancy. The incidence of osteopenia varies between 8 and 23%, but confounding factors were the use of chemotherapy and the effects of prophylactic cranial irradiation. The factors influencing bone atrophy are no more clearly defined in adults treated for cancer by high dose local radiation-therapy. Pathological observed in patient tissues, indicates a clear role for vascular changes in the development of osteopenia, although there remains some uncertainty as to the effects of osteoblast cell loss. Reduced blood flow in bone is clearly dose-related in experimental animal studies and after single doses of >20 Gy changes in bone mineral content have been found. However, this was only at late times (>/=30 weeks) after irradiation. The relationship between these changes and bone strength remains unproven because of the limited nature of many of the animal studies. Radiation dose fractionation data for rib-fracture in breast cancer patients suggests an alpha/beta ratio is in the range 1.8-2.8 Gy, comparable to values obtained for other late responding normal human tissues.

Prognostic indicators for gastrointestinal stromal tumours: a clinicopathological and immunohistochemical study of 108 resected cases of the stomach.

Abstract: Aims Whether immunohistochemical markers increase accuracy in predicting prognosis for gastrointestinal stromal tumours (GISTs) remains uncertain. However, past studies have used only small, heterogeneous patient groups. Our aim was to test previously studied and more novel morphological features as well as four immunohistochemical markers as prognostic indicators amongst a large cohort of surgically resected, gastric GISTs. Methods and results Tissues from 127 gastric mesenchymal tumours were collected retrospectively and subjected to repeat histological assessment and immunophenotyping. Further immunohistochemistry was performed for Ki67, p53, Bcl-2 and cyclin D1. Complete follow-up data were collected for 108 patients with immunophenotyped diagnoses of GIST (i.e. c-kit+ tumours). At the census point, 52 patients were alive, 24 had died from their GISTs and the remainder of other causes. Univariate analysis showed the following predicted for shorter disease-specific survival: size > or =50 mm; necrosis, no intratumoral lymphocytes; mitotic count > or =5/50 high power fields; Ki67 labelling index > or =5%; p53 immunopositivity. Of these variables, multivariate analyses showed only mitotic count and, to a lesser extent, Ki67 labelling to be independent prognostic indicators. Conclusions Mitotic count remains the best predictor of outcome following surgical resection of gastric GISTs. Ki67 immunohistochemistry does not provide better prognostication and p53, Bcl-2 and cyclin D1 immunohistochemistry provide no additional prognostication.

Murine EMT-6 Carcinoma: High Therapeutic Efficacy of Microbeam Radiation Therapy

Abstract: Microbeam radiation therapy is an experimental modality using parallel arrays of thin ( 75%), not only were the above toxicities lower for the cross-planar microbeams than for the broad beams (P < 0.02), but severe leg dysfunction was also lower (P < 0.003). These findings suggest that single-fraction microbeams can ablate tumors at high rates with relatively little normal-tissue toxicity.

Evidence of oxidative stress in chronic venous ulcers.

Abstract: Reactive oxygen species have been implicated in the impaired healing of chronic leg ulcers but little direct evidence is available. We have observed a significant (p < 0.01) elevation of the allantoin : uric acid percentage ratio, a marker of oxidative stress, in wound fluid from chronic leg ulcers (median 17, range 8–860) compared to both paired plasma (median 2, range 1–8) and acute surgical wound fluid (median 4, range 3–7). However, the allantoin : uric acid percentage ratio did not differ significantly between chronic wounds that healed and those that failed to heal. Neutrophil elastase was elevated 30- to 1300-fold in chronic wound fluid compared to plasma and there was a correlation (r 2 = 0.742) between wound fluid elastase and the allantoin : uric acid percentage ratio. Total antioxidant capacity of wound fluid, as measured with a chemiluminescence assay, did not show a correlation (r 2 = 0.03) with the observed oxidative stress. These observations suggest that conditions of localized oxidative stress, possibly related to neutrophil-associated production of reactive oxygen species, are present in chronic leg ulcers. It is possible that future therapeutic strategies aimed at reducing oxidative stress, in addition to good standard care, could improve healing rates of chronic wounds. (WOUND REP REG 2003;11:172–176)

Live related renal transplantation: psychological, social, and cultural issues.

Abstract: Cadaveric donation rates have remained static, whereas transplant waiting lists continue to rise as demand for renal transplants far exceeds supply. One solution to bridge the supply and demand gap is to increase live donation. If live donation is to increase, it is important to offer evidence-based psychologic and social support to ensure that transplant clinical success is not at the cost of psychologic and social harm. This article reports the findings of two substantive qualitative studies, both examining similar aspects of live donation: study A from a psychologic perspective and study B from a social-cultural perspective. The findings show that living-related renal donors do not express regret after donation and do report enhanced self-esteem. The decision to donate is immediate and altruistic for most parents, although some fathers expressed a degree of ambivalence. The decision to donate is more difficult and complex for siblings and may lead to conflict between family of birth and family of marriage. Reciprocity and feelings of obligation did not appear to cause relationship difficulties for siblings but were reported by some of the adolescent recipients who had received a parental graft, leading to psychologic distress and social-familial alienation. These two qualitative studies have demonstrated psychosocial risks within the live donation process. These risks should be recognized within transplant programs and professional care provided to ensure confidential presurgery donor and recipient advocacy and continuing psychosocial support for the family unit postdonation.

Improvement of chemotherapy efficacy by inactivation of a DNA-repair pathway

Abstract: Summary Tumour resistance and dose-limiting toxic effects restrict treatment with most chemotherapeutic drugs. Elucidation of the mechanisms of these effects could permit the development of ways to improve the effectiveness of currently used agents until better therapeutic agents are developed. Several types of alkylating agents are used in the treatment of cancer. The DNA repair protein, O6-alkylguanine-DNA alkyltransferase (ATase) is an important cellular resistance mechanism to one class of alkylating agents. This enzyme removes potentially lethal damage from DNA and experiments in vitro and in vivo have shown that its inactivation can reverse resistance to such agents. Clinical trials of drugs that inactivate ATase are underway and early results indicate that they are active in tumour tissues. However, the ATase present in normal tissues, particularly bone marrow, is also inactivated, necessitating a reduction in the dose of alkylating agent. An important question is whether, in the absence of any tumour-specific delivery strategy, such drugs will improve therapeutic effectiveness; initial reports are not promising.

Hypertrichosis in females applying minoxidil topical solution and in normal controls

Abstract: Background Hypertrichosis has been reported more frequently in females than in males who use minoxidil topical solution (MTS) for the treatment of androgenetic alopecia (AGA). This article examines the occurrence of MTS-induced hypertrichosis in females. Methods Data from placebo-controlled clinical trials in females (up to 5% MTS) were analysed based on spontaneous reports of hypertrichosis/facial hair and investigators’ inquiries (solicited) about the presence of any new hair growth on body parts other than the scalp. A postmarketing drug surveillance database for MTS was also examined for reports of hypertrichosis/facial hair. Results In the clinical trials involving a total of 1333 females, spontaneous reports of hypertrichosis/facial hair were noted for 50 (4%) females in a dose-related pattern of response (5% MTS > 2% MTS > placebo). Nine females (seven and two in the 5% MTS and 2% MTS groups, respectively) discontinued treatment because of hypertrichosis/facial hair. Solicited reports of excessive hair growth (primarily facial) also showed a dose-related pattern of response. Post-marketing data showed a lower occurrence (0.5%) of hypertrichosis/facial hair than in the clinical trials. Of interest, in one clinical trial, 27% of the females enrolled (MTS and placebo treated) had facial hair growth reported at baseline. Conclusions Females with some hirsutism are particularly prone to seek treatment for AGA, and this may explain the high occurrence of hypertrichosis/facial hair found in the MTS clinical trials. Furthermore, some demographic groups of females are prone to develop facial hair and the problem of unwanted facial hair growth seems to be underestimated. Some females may have hair follicles that are very sensitive to MTS and should use the lowest strength of MTS (2%) to help avoid unwanted hair growth. The hypertrichotic effect of MTS on other sites than the scalp, including the face, is reversible and does not always require discontinuation of therapy.

Language impairment in dementia: impact on symptoms and care needs in residential homes.

Abstract: Background Impairment of language skills affects the level of functioning of an individual, interferes with effective communication and can result in development of disruptive behaviour. Social skills and capacity for self care may be compromised. Few studies have evaluated the impact of language problems on symptoms and socialization in people with dementia in care environments. Method 315 elderly residents with dementia (29% living in nursing homes, 71% in social care facilities) were assessed using standardized psychiatric schedules including the Sheffield Screening Test for Acquired Language Disorders and Neuropsychiatric Inventory. Dementia Care Mapping was undertaken at random in at least 50% of residents in each facility. Results Expressive language impairment was associated with the presence of delusions even when severity of dementia was controlled for (p=0.02) and showed a tendency of association with depression (p=0.06). Receptive language difficulties were strongly associated with presence of Aberrant Motor Behaviour, even controlling for severity of dementia (p=0.04). Decreased participation in social activities was correlated with both expressive (p=0.048) and receptive aspects of language (p<0.01) but social withdrawal was only correlated with receptive language difficulties (p=0.01). Conclusion Language disorders are associated with both behavioural and psychological symptoms of dementia even when severity of dementia is controlled for. Patients' needs in communication skills should be addressed earlier to help them maintain social interactions and reduce the impact on behavioural problems and patients' quality of life. Copyright © 2003 John Wiley & Sons, Ltd.

Expression of the cell death genes BNip3 and NIX in ductal carcinoma in situ of the breast; correlation of BNip3 levels with necrosis and grade.

Abstract: Ductal carcinoma in situ (DCIS) of the breast is an early, non-invasive lesion and the prognosis is associated with the extent of necrosis and cell death within the tumour. Two cell death genes, BNip3 and NIX, are up-regulated in response to hypoxia in breast carcinoma cells, although any involvement of either gene in disease progression is currently unknown. This study has analysed the expression of BNip3 and NIX in 56 samples of breast DCIS, as well as in adjacent benign and invasive breast tissue. Both genes are strongly expressed in the epithelial component of a subset of DCIS and invasive disease. The data show a correlation between high expression of BNip3 in the DCIS cells and a high-grade, necrotic lesion that is likely to be associated with invasive tumour. BNip3 was present in tumour-associated macrophages and in apocrine metaplastic lesions. Expression of NIX did not correlate with any of the parameters investigated.

Nitric oxide and beta-adrenergic stimulation are major regulators of preprandial and postprandial subcutaneous adipose tissue blood flow in humans.

Abstract: Background— Blood flow mediates the metabolic and endocrine roles of adipose tissue. We have previously shown that the postprandial adipose tissue blood flow (ATBF) increase is dependent on insulin sensitivity. However, subcutaneous local insulin delivery had no demonstrable effect on either preprandial or postprandial ATBF. We hypothesized that insulin may act indirectly via sympathetic activation, mainly in the postprandial period, and that nitric oxide may be an overall major regulator of subcutaneous ATBF. Methods and Results— We investigated the endogenous preprandial and postprandial regulation of ATBF by applying local tissue blockade of β-adrenergic (propranolol), α-adrenergic (phentolamine and yohimbine), and nitric oxide (NG-monomethyl-l-arginine, L-NMMA) regulation of blood flow. Healthy subjects (body mass index, 18 to 31 kg/m2) were challenged with 75 g glucose for endogenous stimulation of ATBF. We used the novel “microinfusion” technique, which allows for simultaneous local delivery of phar...

Parathyroid adenomas and cardiovascular risk.

Abstract: In recent decades, primary hyperparathyroidism (pHPT) has changed its clinical presentation from a disease with bone and renal involvement to a frequently asymptomatic disorder detected on routine biochemistry. Nevertheless, it remains unclear whether patients with untreated mild asymptomatic hyperparathyroidism are at risk for other complications such as increased morbidity and mortality from cardiovascular diseases. There are limited data on the incidence of cardiovascular abnormalities in mild pHPT. However, pHPT has been associated with increased risk of death from cardiovascular disease, hypertension, left ventricular hypertrophy (LVH), valvular and myocardial calcifications, impaired vascular reactivity, alterations in cardiac conduction, impaired glucose metabolism, dyslipidaemia, and alterations in body composition. The nature of some of these associations is in question, because cure of pHPT does not lead to improvement of the cardiovascular disorder e.g. hypertension. In contrast, currently available data suggest that LVH, impaired glucose metabolism and dyslipidaemia may improve after surgery and that successful parathyroidectomy could decrease the excess mortality in patients with pHPT due to cardiovascular disease.

Single dose oral celecoxib for postoperative pain.

Abstract: Background Celecoxib is a selective cyclooxygenase-2 (COX-2) inhibitor prescribed for the relief of chronic pain in osteoarthritis and rheumatoid arthritis. The drug is believed to be associated with fewer adverse effects than conventional non-steroidal anti-inflammatory drugs (NSAIDs). However, the effectiveness of celecoxib in the treatment of acute pain has not yet been assessed by systematic review. Objectives To assess the analgesic efficacy and adverse effects of a single oral dose of celecoxib for moderate to severe postoperative pain. Search strategy We searched the Cochrane Library Controlled Trials Register, MEDLINE, Biological Abstracts, PubMed and the Oxford Pain database. Date of the most recent search: May 2002. Selection criteria Randomised controlled trials (RCTs) of adults prescribed any dose of oral celecoxib or placebo for acute postoperative pain were included. Data collection and analysis Two trials (418 subjects) met the inclusion criteria for this review. The trials were assessed for quality and the data extracted by two independent reviewers. Summed pain relief (TOTPAR) or pain intensity difference (SPID) was extracted and converted into dichotomous information yielding the number of patients with at least 50% pain relief over 4-6 hours. These derived results were used to calculate the relative benefit (RB) and number-needed-to-treat (NNT) for one patient to achieve at least 50% pain relief. Main results The number-needed-to-treat for celecoxib 200 mg compared with placebo was 4.5 (CI 3.3 to 7.2). For every 4.5 patients experiencing moderate to severe acute pain treated with celecoxib 200 mg one more will experience at least 50% pain relief that would not have done had they received placebo. The median time to remedication over 24 hours was 5.1 hours with celecoxib 200 mg and 1.5 hours with placebo. Quantitative analysis of adverse effects was not possible but no serious or unexpected adverse effects were reported. Reviewer's conclusions Single dose oral celecoxib is an effective means of postoperative pain relief, similar in efficacy to aspirin 600/650 mg, and paracetamol 1000 mg. The two trials included used celecoxib 200 mg, a dose 50% less than is recommended for acute pain. More trials are needed to estimate efficacy for recommended dose of 400 mg, and to reinforce current findings for 200 mg, and provide data for pooled quantitative estimates of adverse effects.

Confirmatory Evidence for Linkage of Relative Hand Skill to 2p12-q11

Abstract: To the Editor: We previously reported in the Journal the first genomewide linkage screen for a measure related to handedness in humans (Francks et al. 2002), in which we found evidence for a quantitative trait locus (QTL) influencing relative hand skill on chromosome 2p12-q11 (P=.00007). The screen was performed using 195 reading-disabled (RD) sibling pairs (Fisher et al. 2002), although reading ability was apparently unrelated to handedness in this sample. The 2p12-q11 linkage was the most significant in the screen by 1.5 orders of magnitude and approached the threshold for genomewide significance proposed by Lander and Kruglyak (1995) (threshold P=.00002). However, we failed to replicate the QTL in a second sample of a similar composition (143 sibling pairs). Therefore, the possibility remained that this was a false positive result, brought about by multiple testing of markers across the entire genome. Now, we have found further evidence for the 2p12-q11 QTL in a new sample of 105 pairs of adult brothers drawn from a sample of 168 unrelated male sibships (338 brothers) that was originally collected for investigating X-linked effects on handedness (described by Laval et al. [1998]). As before, we assessed relative hand skill using the test of Annett (1985), which involves measuring the time taken to move, with each hand, a row of pegs from one set of slots on a board to another. A relative hand skill quotient, PegQ, was derived for each subject as (L-R)/[(L+R)/2]; that is, the difference between left and right hand times, adjusted for overall hand skill (fig. 1a). Figure 1 a, PegQ distribution in 222 siblings with RD who appeared normal for this measure and were previously analyzed genomewide for linkage (black) and in 338 left-writing-handed brothers from whom the current study sample was drawn (gray). Positive scores ... The recruitment criterion that all brothers in each sibship should write with their left hands constituted a form of imperfect phenotypic selection for PegQ. This resulted in curtailed PegQ variance in the 338 brothers (fig. 1a) and suggested that quantitative linkage analysis of the whole sample might be underpowered. We therefore selected sibships on the basis of their suitability for linkage analysis with basic DeFries-Fulker regression (Fulker et al. 1991), which can derive power from extreme phenotypic selection. Extreme left handed “probands” were designated as scoring below −1.5 SD (fig. 1a), relative to the sample of reading-disabled siblings (who scored as an unselected population for relative hand skill). This yielded 101 probands in 88 independent sibships. The threshold of −1.5 SD was chosen to balance increased power from increasing severity of selection against diminishing power because of reduced sample size. No other threshold scores for designating probands were used. We genotyped the 88 sibships at seven microsatellite markers spanning 2p16-q14 and obtained multipoint identity-by-descent (IBD) sharing information across this interval, using the software Genehunter 2.1 (Pratt et al. 2000). Allele frequencies were calculated using data from all parents plus one random sibling in each family, and the genetic marker map was the same as used by Francks et al. (2002) (see fig. 1b). We then assessed the regression of PegQ in brothers of extreme left-handers toward the population mean, as a function of proband scores and IBD sharing with probands, using basic DeFries-Fulker regression as implemented in SAS macros by Lessem and Cherny (2001). A double entry procedure was used when a sibship contained more than one proband, as recommended (Fulker et al. 1991). This yielded a total of 91 independent proband-cosib pairs and 105 total proband-cosib pairs. Unbiased pointwise empirical significance levels for multipoint linkage results were obtained by performing 100,000 genotype simulations while fixing the family structures and phenotypes of the real sample (as described by Francks et al. [2002] and Fisher et al. [2002]) and then analyzing these replicates for linkage. The peak linkage t score was −3.51 (fig. 1b), asymptotic pointwise P=.00035, empirical pointwise P=.00090, thus greatly exceeding significance guidelines for confirmation of linkage (guideline P=.01; Lander and Kruglyak [1995]). The new linkage curve was strikingly similar to that found in the genomewide screen, and this concordance provides confirmatory evidence for the QTL over and above the significance level of the linkage (fig. 1b). This linkage evidence confirms that, although handedness variation may be etiologically complex, there is at least one polymorphic genetic influence that is located on 2p12-q11. Epidemiological studies of twins have provided ambiguous data that point either to weak or else to nonsignificant genetic effects on handedness (Bishop 2001), but no large-scale twin studies have used the greater potential power inherent in a continuous description of the trait, whereas PegQ has shown familialities of up to 35% in our samples (Francks et al. 2002). Linkage analysis of handedness as a dichotomous trait is, therefore, likely to be underpowered, but only one study has so far attempted this approach, and for only six genomic regions (not including 2p12-q11), without identifying suggestive or significant linkage (Van Agtmael et al. 2002). Sex-dependent effects on cerebral lateralization and on the inheritance of handedness have pointed to the involvement of an X-linked genetic effect on handedness (Corballis et al. 1996; McKeever 2000), and suggestive or weak evidence for linkage of relative hand skill to a locus on Xq21 has been identified in both our RD siblings and the left-handed brothers (Laval et al. 1998; Francks et al. 2002), although Crow (2002) has suggested that any X-linked effect may be mediated by an epigenetic mechanism. Roughly 90% of individuals perform complex manual tasks preferentially with their right hands, whereas slightly <10% are left-handed, and a small proportion are ambidextrous (McManus and Bryden 1992). No other primates show a population-level bias in handedness, and individual differences in human handedness are correlated with cerebral hemispheric asymmetries that underlie much complex human cognition, including language (McGrew and Marchant 1997; Geschwind et al. 2002), as well as with asymmetries of the motor cortex (Amunts et al. 1996). We predict that genes containing variants that influence handedness have an important role in the development of cerebral lateralization and may have been involved in the evolution of complex human cognition.

Chemosensitization of human prostate cancer using antisense agents targeting the type 1 insulin‐like growth factor receptor

Abstract: OBJECTIVE To assess the effect of the downregulation of type 1 insulin-like growth factor receptor (IGF1R) on the chemosensitivity of prostate cancer cells. IGF1R is overexpressed by prostate cancer compared with benign prostatic epithelium and IGF1R expression commonly persists in androgen-independent metastatic disease at levels comparable to those in the primary. MATERIALS AND METHODS Human androgen-independent DU145 prostate cancer cells were transfected with IGF1R antisense oligonucleotides or antisense RNA. Transfected cultures were treated with cisplatin, mitoxantrone, paclitaxel or vehicle control, and survival measured using a clonogenic assay. RESULTS Both antisense strategies suppressed IGF1R protein levels to 30–50% of those in control cultures. This was associated with 1.5–2-fold enhancement of sensitivity to cisplatin, mitoxantrone and paclitaxel, and an increase in cisplatin-induced apoptosis. CONCLUSION This approach has potential for development as a clinical treatment for advanced prostate cancer and other chemoresistant tumours.

Successful Palliation and Significant Remission of Cutaneous Calcinosis in CREST Syndrome With Carbon Dioxide Laser

Abstract: Background. There are few satisfactory medical or surgical therapies for cutaneous calcinosis in connective tissue disorders. Objective. Carbon dioxide laser vaporization allows precise ablation of superficial dystrophic calcification. This treatment modality was considered because of the severity of our patient's symptoms and failure to respond to various medical therapies. Methods. Over a 5-year period, six affected digits received a single treatment with carbon dioxide laser vaporization. Results. Treated digits healed over a 6-week period and led to a significant remission in symptoms. The average remission time for affected digits to date is at least 3 years and has allowed our patient to remain in full-time employment. Conclusion. Carbon dioxide laser vaporization may offer effective remission of symptoms in cutaneous calcinosis of CREST syndrome (including cutaneous calcinosis, Raynaud's phenomenon, sclerodactyly, and telangiectasia).