Showing papers by "University of Puerto Rico, Medical Sciences Campus published in 2001"

Family cancer history and susceptibility to oral carcinoma in Puerto Rico.

Abstract: BACKGROUND Use of alcohol and tobacco are the major risk factors for cancers of the oral cavity and pharynx in most of the world. A heritable component to oral carcinoma risk also has been suggested, although only limited data are available on familial aggregation of this disease. METHODS A population-based case–control study of 342 subjects with carcinomas of the oral cavity and pharynx (oral carcinoma) and 521 controls was conducted in Puerto Rico. The relation between family history of carcinomas of the oral cavity, the upper aerodigestive tract (UADT), and other selected sites with risk of oral carcinoma was explored using logistic regression modeling techniques. RESULTS Risk of oral carcinoma was elevated for subjects reporting a first-degree relative with carcinoma of the oral cavity (odds ratio [OR], 2.5; 95% confidence interval [CI], 0.8–8.0) or any UADT carcinoma (OR, 2.6; 95% CI, 1.4–4.8). The increased risk associated with family history of UADT carcinoma tended to be greatest for subjects with known risk factors (i.e., heavy consumption of alcohol and/or tobacco and infrequent intake of raw fruits and vegetables) and with oral carcinoma diagnoses at ages younger than 65 years. CONCLUSIONS These findings are consistent with a heritable component to oral carcinoma, although shared lifestyle risk factors may be partially involved. Cancer 2001;92:2102–8. © 2001 American Cancer Society.

Content and construct validity of a Spanish translation of the Pediatric Evaluation of Disability Inventory for children living in Puerto Rico

Abstract: Although Puerto Rican children with disabilities are at high risk for poor developmental outcomes, no standardized measures are validated for use with these children. In this study, we evaluated the content and construct validity of a Spanish translation of the Pediatric Evaluation of Disability Inventory (PEDI) for use with children living in Puerto Rico. Methods included expert content review, surveys of parents, and the evaluation of 44 children with and without disabilities, who were matched for socio-economic status, age, and gender. The results demonstrated that the translated version of the PEDI is valid; yet additional research is warranted to identify socio-cultural influences on the performance and capability of typically developing Puerto Rican children.

Cembranoid and long-chain alkanol sites on the nicotinic acetylcholine receptor and their allosteric interaction.

Abstract: Long-chain alkanols are general anesthetics which can also act as uncharged noncompetitive inhibitors of the peripheral nicotinic acetylcholine receptor (AChR) by binding to one or more specific sites on the AChR. Cembranoids are naturally occurring, uncharged noncompetitive inhibitors of peripheral and neuronal AChRs, which have no demonstrable general anesthetic activity in vivo. In this study, [3H]tenocyclidine ([3H]TCP), an analogue of the cationic noncompetitive inhibitor phencyclidine (PCP), was used to characterize the cembranoid and long-chain alkanol sites on the desensitized Torpedo californica AChR and to investigate if these sites interact. These studies confirm that there is a single cembranoid site which sterically overlaps the [3H]TCP channel site. This cembranoid site probably also overlaps the sites for the cationic noncompetitive inhibitors, procaine and quinacrine. Evidence is also presented for one or more allosteric cembranoid sites which negatively modulate cembranoid affinity for th...

Sociocultural influences on disability status in Puerto Rican children.

Abstract: BACKGROUND AND PURPOSE: This article describes culturally defined meanings of childhood function and disability in Puerto Rico to provide a context for the interpretation of test scores from the Spanish translation of the Pediatric Evaluation of Disability Inventory (PEDI). SUBJECTS AND METHODS: More than 600 Puerto Rican teachers, parents and caregivers of children with and without disabilities, and members of the general community participated in ethnographic interviews, which were designed to describe their beliefs, attitudes, and knowledge about childhood function and disability. RESULTS: Qualitative and quantitative data analysis confirmed that differences exist between Puerto Ricans and the norms established in the United States for the performance of functional skills by children, and the analysis also described Puerto Rican beliefs and attitudes toward disability. DISCUSSION AND CONCLUSION: Puerto Rican values of interdependence, anonar (pampering or nurturing behaviors), and sobre protectiva (overprotectiveness) influence parental expectations for the capability of children with disabilities and should be considered when interpreting scores from the PEDI and establishing plans of care. Additional research is needed on the influence of contextual variables on child development and behavioral adaptations to disability.

Natural history and incidence of premature thelarche in Puerto Rican girls aged 6 months to 8 years diagnosed between 1990 and 1995.

Abstract: OBJECTIVE To describe the natural history and estimate the incidence of premature thelarche in girls aged 6 months to 8 years living in Puerto Rico and diagnosed between 1990 and 1995. BACKGROUND In the 1970s and 1980s, several pediatric endocrinologists, based on their clinical experience, acknowledged a dramatic increase in the number of cases of precocious sexual development in Puerto Rico. In 1987, the Puerto Rico Health Department developed the Registry of Premature Thelarche and Precocious Sexual Development, which began to operate in 1989. Data regarding the long-term outcomes of girls diagnosed with premature thelarche are insufficient. Knowledge about the natural history of this condition is relevant for predicting the long-term prognosis and therapeutic management of the affected population. METHODS Of 2,716 cases of precocious sexual development reported to the Premature Thelarche and Precocious Sexual Development Registry, 1,916 (70.5%) were premature thelarche. The clinical characteristics and evolution during follow-up of premature thelarche cases were described and compared by age group at diagnosis. RESULTS Incidences were 6.2 and 1.62 per 1,000 live births for girls aged < 2 years and 2 to 8 years, respectively. These estimates were 10 and 15 times higher than those reported in Olmsted, MN. When the average change in mammary tissue diameter during follow-up was evaluated, a slight reduction in girls aged < 2 years was observed; however, it remained constant for girls aged 2 to 8 years. CONCLUSIONS The results of this study underscore the need to continue an active search of premature thelarche cases and to perform analytical investigations of precocious sexual development to expand the understanding of the etiology of this important public health problem.

Presynaptic effects of biogenic amines modulating synaptic transmission between identified sensory neurons and giant interneurons in the first instar cockroach

Abstract: Intracellular recording was used to investigate the modulatory effects of serotonin and octopamine on the identified synapses between filiform hair sensory afferents and giant interneurons in the first instar cockroach, Periplaneta americana. Serotonin at 10–4 mol l–1 to 10–3 mol l–1 reduced the amplitude of the lateral axon-to-ipsilateral giant interneuron 3 excitatory postsynaptic potentials, and octopamine at 10–4 mol l–1 increased their amplitude. Similar effects were seen on excitatory postsynaptic potentials in dorsal giant interneuron 6. Several lines of evidence suggest that both substances modulate the amplitude of excitatory postsynaptic potentials by acting presynaptically, rather than on the postsynaptic neuron. The fitting of simple binomial distributions to the postsynaptic potential amplitude histograms suggested that, for both serotonin and octopamine, the number of synaptic release sites was being modulated. Secondly, the amplitudes of miniature excitatory postsynaptic potentials recorded in the presence of tetrodotoxin were unaffected by either modulator. Finally, recordings from contralateral giant interneuron 3, which has two identifiable populations of synaptic inputs, showed that each modulator had a more pronounced effect on excitatory postsynaptic potentials evoked by the lateral axon than on those evoked by the medial axon. Immunocytochemistry confirmed that neuropilar processes containing serotonin are present in close proximity to these synapses.

Expression and purification of recombinant hemoglobin I from Lucina pectinata.

Abstract: Hemoglobin I (HbI) from Lucina pectinata reacts with hydrogen sulfide to form the ferric sulfide complex needed to transport H2S to the bacterial endosymbiont. To further study HbI, expression studies of this protein were performed in Escherichia coli. This is the first time that the recombinant HbI was produced using a recombinant DNA expression system. Hemoglobin I cDNA was amplified and cloned into the TOPO-PBAD expression vector, which contains a fusion tag of six histidine residues (6XHis tag). Plasmid clone sequence analysis was carried out in order to ensure that the insert was in the correct reading frame for proper protein expression in E. coli. The expression of recombinant HbI was optimal when induced for 5 hr with 0.002% of L-arabinose as detected by Western blot analysis. The proto-porphyrin group was inserted into the recombinant HbI. Purification of the heme-bound recombinant protein was performed under native conditions by affinity chromatography using Ni-NTA and Probond resins. The sodium dithionite-reduced recombinant protein presented a shift from the Soret band at 413-435 nm, indicating the presence of the heme group in the adequate amino acid environment of HbI. These results indicate that recombinant HbI from Lucina pectinata can be successfully expressed in a prokaryotic system retaining its activity toward reduction, oxidation, and ligand binding.

Predictors of adverse events after percutaneous transluminal coronary angioplasty in a group of Hispanic patients.

Abstract: OBJECTIVE: To identify predictors of adverse events after PTCA during hospitalization and after hospital discharge in a private hospital in Puerto Rico. BACKGROUND: A review of the literature shows limited information about predictors of adverse events associated to percutaneous transluminal coronary angioplasty (PTCA) in Hispanic patients. METHODS: This is a non-concurrent prospective study. Baseline variables were analyzed using multivariate logistic regression to identify predictors of adverse events. Data were collected from medical charts and telephone reports from referring physicians. RESULTS: Data from 197 subjects undergoing PTCA were analyzed for this study. Median age of patients was 65 years, and 62.9% of patients were male. Angiographic success rate was 81.6%. A total of 8.1% of patients had at least one in-hospital adverse event, and 39.8% had at least one adverse event after hospital discharge. After multivariate analysis, a statistically significant association was found between the presence of at least one lesion with residual stenosis of 50% or greater and the risk of developing adverse events in-hospital (RO 11.75; 95% CI 4.32-31.97). A marginally significant association was found between family history of heart disease (RO 2.75; 95% CI 0.93-8.11) and the risk of adverse events during hospitalization. Family history of heart disease (RO 1.41; 95% CI 0.98-2.04) and the presence of at least one lesion with residual stenosis of 50% or greater (RO 2.87; 95% CI 0.82-10.01) showed marginally significant associations with increased risk for adverse events after discharge. CONCLUSIONS: These findings suggest that the presence of at least one lesion with residual stenosis of 50% or greater and family history of heart disease may be risk factors for adverse events after PTCA during hospitalization and after discharge.

Retrospective analysis of the effects of low-dose, high frequency human growth hormone on serum lipids and prostate specific antigen

Abstract: Background. Elevated serum total cholesterol (TC) and triglycerides (TG) are risk factors for atherosclerosis and ischemic heart disease. Adult growth hormone deficiency (AGHD) is associated with elevated TC and TG. Many treatment protocols for AGHD use relatively high doses of growth hormone (GH) given at low frequency, which is associated with increased incidences of edema, joint pains, and carpal tunnel syndrome. We have treated > 2200 patients using a low-dose high frequency (LDHF) dosing regimen of GH which results in similar beneficial subjective responses, and fewer of the side-effects associated with the higher-dosage treatment at a substantial cost savings. Clinically, in addition to increased insulin-like growth factor I (IGF-I), we observed lower TG and TC levels and no elevation of prostate specific antigen levels in treated patients. Methods. A retrospective analysis of IGF-I, TG, TC, and PSA data from our patient population was performed to test our hypothesis that positive objective responses of IGF-I, TG, and TC occur and that elevation of PSA does not occur in response to LDHF dosing regimen of GH. The mean duration of treatment of the analyzed data ranged from 181 to 259 days. Results. The mean plasma IGF-I level rose significantly (p<.00001) to a level 37% greater than baseline with treatment. TC and TG decreased significantly (p<.001) in those patients with elevated baseline values, and did not change significantly in those with normal baseline values. PSA concentrations decreased non-significantly during treatment, and few cases of edema, joint pain, or carpal tunnel were reported. Conclusions. Treatment of AGHD using the LDHF dosing regimen of GH resulted in significant increases in IGF-I, significant reductions in TC and TG levels in patients with elevated baseline values, no increase in PSA concentrations, and fewer side effects than other dosing regimens.