Showing papers by "Catholic University of the Sacred Heart published in 1991"

Early orientation of attention toward the half space ipsilateral to the lesion in patients with unilateral brain damage

Abstract: Posner has suggested that unilateral spatial neglect could be due to a difficulty in disengaging attention from its current focus to orient it toward the neglected half space. Clinical and experimental data suggest, however, that this disengaging difficulty could be only one aspect of a more complex disturbance also characterized by an early automatic orienting of attention toward the half space ipsilateral to the lesion. To test this hypothesis, two different investigations in unselected groups of patients with right and left brain-damage were carried out. The first investigation, to evaluate forms of lateral orienting of attention severe enough to provoke an overt gaze deviation, consisted of the systematic assessment of the phenomenon of "magnetic gaze attraction". The second investigation, to detect milder forms of automatic orienting of attention, analysed the temporal sequence followed in identifying the pictures represented in an "Overlapping Figures task", to see if patients tended to identify first figures lying in the half space ipsilateral to the lesion. In both investigations results consistently showed: a) that patients with right brain damage tend to orient attention automatically toward the ipsilateral half space more than patients with left brain damage; b) that this tendency is tightly linked to the presence of behavioural manifestations of hemi-neglect. These results are therefore consistent with the hypothesis that hemi-neglect is a multi-component syndrome with an early orienting of attention toward the half space ipsilateral to the lesion as the first of these components.

Dissociation between knowledge of living and nonliving things in dementia of the Alzheimer type

Abstract: Patients who survive herpes simplex encephalitis (HSE) sometimes present a category-specific disorder for living things. Since HSE specifically involves the temporolimbic structures of both hemispheres, these structures could play a critical role in processing and storing information about living things. If this were the case, a category-specific disorder for the same items should also be observed in the early stages of dementia of the Alzheimer type (DAT) as the temporolimbic structures are often severely affected in this condition. To test this hypothesis, we administered to 15 DAT patients and to 10 normal controls a confrontation-naming task and a verbal associates recognition task, with both living and nonliving items as stimuli. The hypothesis was confirmed, since DAT patients performed worse with living than with nonliving items, and scored worse than normal controls on the living but not the nonliving items.

Dominantly inherited mitochondrial myopathy with multiple deletions of mitochondrial DNA Clinical, morphologic, and biochemical studies

Abstract: We studied a large family with a dominantly inherited mitochondrial myopathy characterized by progressive external ophthalmoplegia, dysphagia, cataract, lactic acidosis, exercise intolerance, and early death. Morphologic studies of muscle biopsies suggested mitochondrial heteroplasmy and revealed ragged-red fibers and decreased histochemical reactions for cytochrome c oxidase and succinate dehydrogenase. Biochemistry showed a partial defect of cytochrome c oxidase and a mild generalized reduction of other mitochondrial enzymes requiring mitochondrial DNA-encoded subunits. Southern blot analysis and PCR amplification showed mitochondrial DNA deletions in muscle of all affected members, but not in lymphocytes or fibroblasts, suggesting a tissue-specific distribution. Deletions were multiple and seemed to increase with time and to correlate with the severity of the disease.

Enalapril prevents cardiac fibrosis and arrhythmias in hypertensive rats.

Abstract: To evaluate the effects of hypertension on cardiac hypertrophy, on myocardial structure, and on ventricular arrhythmias, 27 3-month-old spontaneously hypertensive rats were treated with enalapril (10 mg/kg) daily for 11 months and compared with 26 untreated control rats. Systolic arterial pressure was significantly decreased in treated rats, and at the end of the experiment, it was 199 +/- 3 mm Hg (treated) versus 237 +/- 3 mm Hg (controls) (p less than 0.001). At this time, spontaneous arrhythmias and induced arrhythmias either by programmed electrical stimulation (train of stimuli +1 or 2 extrastimuli) or by trains of eight stimuli at decreasing coupling intervals were observed in isolated heart preparations. Comparing enalapril-treated and control rats, spontaneous arrhythmias (9 of 27 versus 20 of 26, respectively; p less than 0.01), programmed stimulation-induced arrhythmias (3 of 26 versus 12 of 23, respectively; p less than 0.01), and trains of stimuli-induced arrhythmias (4 of 26 versus 14 of 19, respectively, p less than 0.001) were less frequent in the enalapril group. Left ventricular weight was decreased in treated rats by 18% (p less than 0.001). Enalapril administration diminished the fraction of myocardium occupied by foci of replacement fibrosis normally occurring in control rats by 59% (p less than 0.001). Finally, a significant correlation was found between left ventricular weight, the extent of myocardial fibrosis, and the occurrence of ventricular fibrillation. It was concluded that chronic treatment with enalapril, which resulted in attenuation of systemic arterial pressure by limiting cardiac hypertrophy and myocardial fibrosis, decreases the propensity of the heart of hypertensive rats to arrhythmogenesis.

Differential diagnosis of fatal and benign cytochrome c oxidase-deficient myopathies of infancy: an immunohistochemical approach.

Abstract: To differentiate the 2 major myopathies of infancy due to cytochrome c oxidase (COX) deficiency, we studied muscle biopsies from 4 patients with fatal myopathy and 4 with benign myopathy using biochemical, histochemical, and immunohistochemical techniques. Immunohistochemistry with antibodies directed against individual subunits of COX differentiated the 2 phenotypes: the fatal infantile myopathy was characterized by absence of the nuclear DNA (nDNA)-encoded subunit VIIa,b of COX, while in the benign myopathy both VIIa,b and the mitochondrial DNA (mtDNA)-encoded subunit II were absent. Early differential diagnosis between fatal and benign COX-deficient myopathies is of critical importance for prognosis and management of these infants, because the benign form is initially life-threatening but ultimately reversible.

Cerebrospinal fluid shunting for hydrocephalus in the adult: factors related to shunt revision.

Abstract: Cerebrospinal fluid shunting procedures are widely employed in the treatment of hydrocephalus and other disturbances of the dynamics of cerebrospinal fluid. In spite of its popularity, this operation frequently requires surgical revision. A retrospective analysis of a series of 356 adults who underwent the insertion of a cerebrospinal fluid shunt between January 1970 and December 1988 was performed. The incidence of revision was analyzed, and an attempt was made to identify possible causal factors. The overall incidence of surgical revisions was 28.65%; the number of revisions in the same patient ranged between one and eight. The most frequent causes of revision were distal malposition, obstruction, and infection. A statistically significant difference (P less than 0.05) was found in both the risk of revision in patients who had undergone previous operations and those who had not and in the incidence of revision before and after January 1985. Meticulous surgical technique as well as perioperative antibiotic prophylaxis appear responsible for the latter. The differences in the incidence of revision among patients treated with different types of shunts and valves, though remarkable, is not statistically significant.

Detection of Inner Retina Dysfunction by Steady-State Focal Electroretinogram Pattern and Flicker in Early IDDM

Abstract: The effects of diabetes on the neural retina before the onset of clinically detectable retinopathy can be investigated with electrophysiological methods. Our aim was to detect early retinal dysfunctions in 60 patients with insulin-dependent diabetes mellitus (IDDM) and with a short duration of disease. We used the steady-state focal (9 degrees field size) electroretinogram (ERG) of the macula in response to luminance modulation of a uniform field (flicker ERG) or to counterphase-modulated sinusoidal gratings (pattern ERG). The harmonic analysis of flicker ERG and pattern ERG yielded three main components: a first and a second harmonic to flicker (1F and 2F, respectively) and a second harmonic to pattern (2P). The 1F is believed to be correlated to photoreceptor activity, whereas 2F and 2P represent different subsets of generators in the inner retina. Results of focal ERG in IDDM patients with no or early retinopathy were compared with age-matched control subjects. Mean 2F and 2P amplitudes were significantly reduced in IDDM patients compared with the control group (P = 0.0001 by analysis of variance). 2P but not 2F amplitude was significantly more reduced in patients with retinopathy than in those without retinopathy (P less than 0.05). 2F but not 2P phase abnormalities were observed in some patients. 2F and 2P alterations were slightly correlated with metabolic control (r = 0.22, P = 0.02) and disease duration (r = 0.28, P = 0.003). 1F was not significantly altered in IDDM patients. Our results suggest that early diabetes causes selective neurosensory deficits of inner retina layers, whereas the photoreceptors appear unaffected.

Local recurrence following abdominoperineal excision and anterior resection for rectal carcinoma.

Abstract: The aim of this retrospective study is to compare the outcome of abdominoperineal excision (APE) and anterior resection (AR) for rectal cancer in terms of local tumor recurrence. A further comparison has been carried out between hand-sewn and stapled anastomosis; 147 patients have been followed for at least 2 years: 69 after APE and 78 after AR, 40 being stapled. The following variables potentially related to the risk of recurrence were evaluated: age, grading, staging, and site of the tumor. An overall 2-year local recurrence rate of 11 percent after APE and 12 percent after AR was observed, whereas it was 13 and 11 percent following stapled and hand-sewn sutures, respectively. Both differences were not statistically significant. A similar local recurrence rate was noted after APE and AR when the patients were matched for Dukes' stage and grading of the lesion. A trend toward an increased risk of recurrence following AR (P = 0.07) was shown when comparing the two procedures if mid and upper rectal cancers were grouped together. In the patients with anastomotic leaks after AR, no increase of local recurrence was observed. In conclusion, AR is unlikely to be followed by an increased risk of local recurrence and, therefore, when oncologically indicated, may be considered the operation of choice in the treatment of rectal cancer, although the possible risk of its overuse should be taken into account.

In vitro Susceptibility of 119 Yeast Isolates to Fluconazole, 5-Fluorocytosine, Amphotericin B and Ketoconazole

Abstract: The in vitro activity of fluconazole was tested against 13 yeast species (119 strains) isolated from clinical specimens during a 3-month period. For comparative purposes, three other antifungal compounds (5-fluorocytosine, amphotericin B and ketoconazole) were also tested. The tests were carried out using a microautomated method previously developed in our laboratory. The method allowed us to determine the minimum inhibitory concentration (MIC) of the four antifungal drugs used. For each of the drugs we utilized different media. The MIC ranges (mg/l) of fluconazole were: 0.04–12.5 for Candida albicans, 0.19–6.25 for Candida parapsilosis, 12.5–50 for Candida krusei, 0.04–100 for Candida tropicalis, 0.04–– > 100 for Candida glabrata, 0.09–– > 25 for Cryptococcus neoformans, 0.09–0.78 for Saccharomyces cerevisiae, 6.25–– > 100 for Trichosporon beigelii and 0.09–0.19 for Blastoschizomyces capitatus (Trichosporon capitatum). The MIC value (mg/l) was 0.39 for Candida guilliermondii and Candida lusitaniae, > 100 for Cryptococcus laurentii and 0.09 for the 3 isolates of Torulopsis Candida. These results were obtained using the medium recommended for in vitro testing of fluconazole (high-resolution medium) by Pfizer UK.

Three high-lysine mutations control the level of ATP-binding HSP70-like proteins in the maize endosperm.

Abstract: The synthesis and deposition of seed storage proteins in maize are affected by several dominant and recessive mutants. The effect of three independent mutations, floury-2 (fl2), Defective endosperm-B30 (De-B30), and Mucronate (Mc), that reduce zein level in the endosperm were investigated. These mutations also control the level of b-70, a polypeptide bound to protein bodies, which is separable into the two isoforms b-70I and b-70II by two-dimensional gel electrophoresis. Both isoforms are overexpressed 10-fold in fl2; however, only b-70I is present in De-B30 and Mc, which contain an amount of total b-70 isoforms fivefold higher than in the wild type. Both b-70I and b-70II resemble heat shock protein (HSP70) in that they bind ATP, cross-react with anti-HSP antibodies, and have N-terminal sequence homology to HSP70. All maize protein body-located b-70 characteristics are typical of those of chaperone-like HSPs. A third protein, b-70III, similar in size to but slightly more acidic than b-70I and b-70II, also binds ATP and reacts with the same antibody, providing evidence for the presence in endosperm extracts of a cytosolic chaperone-like protein. The level of b-70III was not altered by the mutations studied. The results suggested that the repression effect of the three mutations on zein accumulation may be mediated by the alteration of a zein transport or zein assembly process involving b-70I and b-70II.

Fibrin-antibiotic mixtures: an in vitro study assessing the possibility of using a biologic carrier for local drug delivery.

Abstract: An in vitro study assessing the kinetics of drug release from antibiotic-fibrin seal compounds and the antibacterial efficacy of the delivered drug has been performed. Antibiotic sensitivity and the amount of drug released was measured by means of agar diffusion test. Standard and experimental curves were established for each antibiotic and each bacterial test in order to evaluate the quantities of the drug released during each 24 h period. The reconstitution of lyophilized human fibrin with an aqueous solution containing an antibiotic resulted in only minor modification of the clotting process, with the exception of those solutions containing cefotaxim and mezlocillin which failed to clot altogether and were excluded from further study. The evaluation of the kinetics of elution of the antibiotics from the fibrin clots showed that all of the antibiotics had been almost completely released by 96 h. The delivered amount of each drug was enough to maintain the Minimal Inhibitory Concentration (MIC) until the 4th day of culture for the most of antibiotics, resulting in a prolonged release of the drug.

Investigations on iron uptake and reduction by excised roots of different grapevine rootstocks and a V. vinifera cultivar

Abstract: Roots from cuttings of grapevine rootstocks V. Berlandieri × V. rupestris 140 Ru, V. Berlandieri × V. riparia S04, V. riparia × V. rupestris 101–14 and a V. vinifera cultivar (Pinot blanc), with a decreasing degree of chlorosis resistance, were excised and tested to quantify physiological and morphological parameters, as follows: 59Fe uptake from an FeEDTA solution; reducing capacity; root diameter and root hair occurrence.

Prognostic factors in colorectal cancer: current status and new trends.

Abstract: The clinical, laboratory, and pathologic data of 361 patients who had curative resections for colorectal cancers were collected and analyzed in a multiple stepwise regression model. In univariate analysis, among clinical factors, bowel obstruction and emergency surgery showed the most significant prognostic value (P = 0.002, P = 0.004, respectively). Vegetating growth, Astler-Coller stage of tumor, intramural spread, lymph node involvement, and synchronous liver metastases resulted in the pathologic variable significantly affecting the prognosis (P = 0.006, P less than 0.001, P = 0.036, P less than 0.001, P less than 0.001, respectively). In the multivariate analysis, stage was the predictive factor with the highest hazard ratio in conjunction with bowel obstruction (P less than 0.0001 in both cases). Processing data excluding stage ("multiparametric factor" itself), hepatic metastases, lymph node involvement, bowel obstruction, and intramural spread appeared as independent predictors of survival (P less than 0.0001, P less than 0.0001, P = 0.0004, P = 0.0316, respectively). Other variables, as biologic and molecular factors, should be more widely tested in order to assess their impact on prognosis.

Spinal cord stimulation and cerebral haemodynamics.

Abstract: After the demonstration that spinal cord stimulation (SCS) can improve peripheral blood flow it was Hosobuchi (’86) who first studied the effect of SCS on cerebral blood flow (CBF) in human beings Our group found that SCS can produce either an increase of CBF or a reduction or no effect In patients studied with both SPECT technique and TCD, the sign of the induced variations, when present in both, was the same Cervical stimulation produces more frequently an increase in CBF (61% of cervical stimulations) Our experimental studies confirm that SCS and CO2 interact with the mechanism of regulation of CBF in a competitive way and produce a reversible functional sympathectomy Further experimental reports suggest that SCS 1) drastically prevents cerebral infarction progression in cats; 2) improves clinical symptoms of patients in persistent vegetative states; 3) suppress headache attacks in migraneous patients; 4) significantly reduces ischemic brain oedema in rats Following these clinical and experimental observations, Hosobuchi first used cervical SCS for the treatment of cerebral ischemia in man (’91) More recently we confirmed the therapeutic effect of SCS on ischemic stroke in humans, experimental brain injury and cerebral vasospasm in rabbits

Guidelines for the preparation and analysis of the fragile X chromosome in lymphocytes.

Abstract: The following guidelines were adopted by an Ad Hoc Committee convened at the Fourth International Workshop on the Fragile X Syndrome and X-Linked Mental Retardation to establish minimum cytogenetic standards for the preparation and analysis of the fragile X chromosome. The intention of the committee was to develop and provide practical standards for the routine cytogenetic detection of the fragile X. The guidelines describe reasonable criteria for effective tissue culture methods for eliciting the Xq27.3 fragile site in vitro and for the analysis of such chromosome preparations.

Inhibition of adenosine 3',5'-cyclic monophosphate phosphodiesterase by flavonoids from licorice roots and 4-arylcoumarins.

Abstract: Isoliquiritigenin, glabridin, licoarylcoumarin and licoricidin were identified as strong inhibitors of adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase in waste materials which were obtained during the industrial extraction of glycyrrhizin from licorice roots. The structure-activity relationships of 12 flavonoids from licorice roots and 34 4-arylcoumarins were studied. In 4-arylcoumarins, 5,7-dihydroxy derivatives were generally highly inhibitory towards cAMP phosphodiesterase.

Proarrhythmic activity of intracoronary endothelin in dogs: relation to the site of administration and to changes in regional flow.

Abstract: The endothelium-derived peptide, endothelin, has been shown to exert powerful constrictor activity in both isolated and in situ coronary arteries. Recent in vitro data on isolated cardiac myocytes suggest that the substance might also possess electrophysiologic properties. We investigated the possibility that endothelin (ET-1) may exert proarrhythmic effects when infused selectively in the coronary circulation of open-chest-anesthetized dogs. Animals were instrumented for the measurement of left anterior descending (LAD) or left circumflex (LCX) coronary artery blood flow, left systolic ventricular pressure (LSVP), dP/dtmax, mean arterial pressure (MAP), and epicardial electrocardiogram (ECG; three leads). Data were recorded during infusion (2 min) of saline (n = 5) or increasing doses of endothelin (5-80 pmol/kg) given selectively in either the LCX (n = 10) or the LAD (n = 10). When infused into the LCX, endothelin produced a dose-dependent decrease in flow (40 +/- 23% at 80 pmol/kg, mean +/- SD, p less than 0.01) with a concomitant increase in coronary resistance and a decrease in dP/dtmax and MAP. ECG changes typical of myocardial ischemia paralleled the decrease in flow and culminated in ventricular fibrillation at the highest dose (80% of dogs). Endothelin caused similar hemodynamic effects when infused in the LAD, but fatal arrhythmias occurred for lower doses and for little or no change in coronary blood flow. Thirty percent of the animals died at 10 and 60% died at 20 pmol/kg, doses that induced only a moderate decrease (8 +/- 7 and 21 +/- 12%, respectively) in LAD total blood flow. Ventricular tachycardia always preceded ventricular fibrillation and death.(ABSTRACT TRUNCATED AT 250 WORDS)

The Noonan-CFC controversy.

Abstract: The Noonan syndrome and the cardio-faciocutaneous (CFC) syndrome have been described as phenotypically and genetically distinct entities. However, the resemblance between them led some authors to question the validity of this separation. We review available clinical evidence to support the opposite view, namely, that the Noonan and CFC syndromes are indeed distinct and separate conditions, both falling within the broad and causally heterogeneous spectrum of the Noonan/congenital lymphedema phenotype.

2-Generation of finite simple groups and some related topics

Abstract: It is well-known that every finite simple group is 2-generated, i.e. it can be generated by two suitable elements. This is the topic discussed in §1, which centers around Steinberg’s unified treatment of groups of Lie type. In §2 we discuss generation of simple groups by special kinds of generating pairs, namely: 1) the generation of simple groups of Lie type by a cyclic maximal torus and a long root element, with application to the solution of the Magnus-Gorchakov-Levchuk conjecture on residual properties of free groups; 2) the generation of a simple group by an involution and another suitable element. With regard to 1), we also mention similar 2-generation results in connection with Galois groups; with regard to 2), emphasis is put on (2,3)-generation and Hurwitz generation of finite simple groups. Finally, §3 deals with generating sets of involutions of minimal size. Most finite simple groups are generated by three involutions. Generation results, a non-generation criterion, and a relation between (2,3)-generation and generation by three involutions are illustrated.

Antiproliferative activity of quercetin on normal bone marrow and leukaemic progenitors.

Abstract: We used an in vitro clonogenic assay in semi-solid medium to test the sensitivity of normal bone marrow and acute myeloid and lymphoid leukaemia progenitors to the flavonol quercetin. We have studied 14 acute myeloid (AML) and four acute lymphoid (ALL) leukaemias. All ALL and the vast majority of AML (12/14) had a high sensitivity to quercetin with more than 50% growth inhibition at 2 x 10(-6) M quercetin. One M3-AML was partially quercetin-sensitive displaying 60% surviving AML-colony forming units (CFU-AML) at a quercetin concentration of 10(-5) M. One M1-AML was resistant to the growth inhibitory effect of quercetin at a concentration of 2 x 10(-5) M. The clonogenic efficiency of both AML and ALL positively correlated with leukaemic colony-forming unit (CFU-L) sensitivity to quercetin suggesting that this parameter can be useful in predicting quercetin responsiveness of leukaemic cells. We have also studied the effect of various quercetin concentrations on colony formation by normal bone marrow cells. At a quercetin concentration of 10(-5) M, we observed (in five different experiments) a mean recovery of 53% and 65% of erythroid blast-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM), respectively. Thus, normal bone marrow appeared partially resistant to quercetin, being inhibited less than 50% by quercetin concentration higher than 2 x 10(-5). When normal bone marrow were deprived in CD34+ haematopoietic progenitors the resultant population became highly sensitive to quercetin, with a mean recovery of BFU-E and CFU-GM of 5% and 12% of controls respectively in the presence of 2 x 10(-5) M quercetin. Furthermore, CD34 progenitors, positively selected, appeared fully resistant to quercetin concentrations as high as 2 x 10(-5) M. Thus, CD34+ progenitors are a quercetin-resistant component in normal bone marrow. In conclusion, our results further provide a biological basis for the therapeutic use of quercetin, considering that this compound could inhibit leukaemic cell growth without suppressing normal haematopoiesis.

Antibiobodies : antibiotic-like anti-idiotypic antibodies

Abstract: Pathogenic micro-organisms such as Candida albicans may be susceptible to the activity of antimicrobial products like yeast killer toxins due to the presence of specific cell wall receptors for these agents. Anti-idiotypic antibodies (anti-Ids) were produced that competed for these receptors with the yeast killer toxin of a strain of Pichia anomala. We report here that affinity chromatography purified anti-Ids may kill C. albicans cells in vitro which are susceptible to the activity of the yeast killer toxin, as well as P. anomala killer cells which are obviously immune to their own toxin despite possessing specific cell wall receptors which can be detected by indirect immunofluorescence with anti-Ids. We propose that these conceptually new antimicrobial immunoglobulins acting as antibiotics be called ‘antibiobodies’.