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Biomedical subjects

S Lai

Publications and source records attributed to S Lai.

At least 91 records · Page 5Linked to original sources
PubMed1998

Implication of HLA-DMA alleles in corsican IDDM.

The HLA-DM molecule catalyses the CLIP/antigen peptide exchange in the classical class II peptide-binding groove. As such, DM is an antigen presentation regulator and may be linked to autoimmune diseases. Using PCR derived methods, a relationship was revealed between DM gene polymorphism and IDDM, in a Corsican population. The DMA*0101 allele was observed to confer a significant predisposition to this autoimmune disease while the DMA*0102 allele protected significantly. Experiments examining polymorphism of the HLA-DRB1 gene established that these relationships are not a consequence of linkage disequilibrium with HLA-DRB1 alleles implicated in this pathology. The study of the DMA gene could therefore be an additional tool for early IDDM diagnosis in the Corsican population.

Adolescent↗
PubMed1998

Effectiveness of HIV interventions among women drug users.

A prospective cohort study was conducted among chronic injecting and crack cocaine drug using women. The hypothesis tested was that participation in a standard-plus-innovative intervention was more likely to produce behavior change than participation in a standard intervention. Standardized intervention protocols and corresponding instruments were designed. Data were collected on drug and sex risk behaviors at baseline and six-month follow-up intervals. The level of behavioral change in two intervention arms--standard and a standard-plus-innovative intervention--was measured by composite sex risk and drug risk scores using the generalized estimating equation approach. The results show that on four risk measures the enhanced intervention was significantly associated with positive change in both drug use and sexual behavior: less frequent drug use, less drug use during sex, and more frequent condom use during particular frequencies for specific types of sexual activities. Public health interventions are effective when targeting specific risk behaviors through interventions tailored to prevent HIV and reduce risk behaviors among specific cultural and gender groups.

Adult↗
PubMed1998

Risk Factors for HTLV-I Mother to Child Transmission: Influence of Genetic Markers.

This study was designed to evaluate the influence of genetic markers on the seropositivity of offspring of HTLV-I positive mothers in Tumaco, Colombia, an endemic area for HTLV-I infection and a site where there exists a racially mixed population of Black and Caucasian ancestors. 33 HTLV-I seropositive women with at least one offspring were studied. A total of 111 offspring were tested using hemaglutination-inhibition for testing sera for the allotypic markers G1m (1, 2, 3, 17) and G3m (5, 6, 13, 21). Potential risk factors such as mother s age at child's birth, mother's age at the time of the study, breastfeeding months, TSP vs. asymptomatic HTLV-I carrier, sibship's size, children's age and sex, were not found to be associated with mother to child transmission. Mother's Negroid genetic marker genotype (1, 17, 5, 13/1, 17, 5, +/- 13) was marginally associated with mother to child transmission of HTLV-I (P=0.0057; OR=11.97; CI=0.92-155.96)

Journal Article↗
PubMed1998

[Studies on the polysaccharide of Fomes marginatus].

This paper reports that polysaccharose was prepared by ethanol precipitation of water extracted and by deproteinization with sevage method, purification obtain Fomes marginatus. The polysaccharose which was determined by using sephadex-G, PAGE, ACTME, TLC and PC is single composition. [alpha]D20 = 28.89, it content of polysaccharose is 22.62 percent. It was hydrolied of periodate oxidation, smith degradation and IR analysis, the results show that the main chain is composed of B-(1-->4), (1-->6) linkage.

Chromatography, Paper↗
PubMed1998

Hospitalization, inpatient physical therapy and institutionalization after hospital discharge of prostate cancer patients in south Florida.

PURPOSE: Explaining survival variation in prostate cancer requires the identification of new predictive factors, of which physical function is attractive hypothetically. To understand physical dysfunction in prostate cancer better, we examined medical claims. Our aims were to describe the consumption of inpatient resources, examine the association of physical therapy with institutionalization after hospital discharge and determine the association of disease stage with frequency of hospitalization, inpatient physical therapy and discharge to a skilled nursing facility. MATERIALS AND METHODS: We used 1994 Medicare claims for patients in South Florida who had prostate cancer. To examine the association of disease stage with use of health services, we inferred disease stage from stage specific treatment. Multiple linear regression was used to examine the interaction of inferred disease stage with health services while adjusting for age. RESULTS: A total of 22,279 residents of South Florida a mean of 78.3 years old with prostate cancer billed Medicare in 1994. Of these patients 2,507 were admitted to a hospital 4,606 times, resulting in total charges of $70 million. Many claims indicated physical dysfunction, including 1,896 charges for physical therapy, which was associated with more institutionalization after hospital discharge. Disease stage and patient age were individually associated with the frequency of hospitalization, inpatient physical therapy and discharge to a skilled nursing facility. CONCLUSIONS: Inpatients with prostate cancer have substantial stage dependent physical dysfunction. If the hypothesized interaction of physical dysfunction with mortality is confirmed in prospective studies and outpatient settings, theoretically the door will have been opened to new interventions for prolonging survival in patients with prostate cancer.

Aged↗
PubMed1998

The significance of changing trends in prostate cancer incidence and mortality.

The increasing incidence of prostate cancer stood for years as a seemingly unshakable axiom of modern medicine. Recent evidence illustrates that the incidence of prostate cancer may have peaked and raises questions about the relative meaning of prostate cancer in the future. This article reviews the many antagonistic factors that will affect prostate cancer incidence and mortality. No projections are offered about incidence and mortality, but it is believed that the number of patient-years with prostate cancer will increase and present new clinical challenges.

Humans↗
PubMed1997

High risk of HIV-related mortality is associated with selenium deficiency.

To determine the independent contribution of specific immunologic and nutritional factors on survival in HIV-1 disease, CD4 cell count, antiretroviral treatment, plasma levels of vitamins A, E, B6, and B12 and minerals selenium and zinc were considered in relation to relative risk for HIV-related mortality. Immune parameters and nutrients known to affect immune function were evaluated at 6-month intervals in 125 HIV-1-seropositive drug-using men and women in Miami, FL, over 3.5 years. A total of 21 of the HIV-1-infected participants died of HIV-related causes during the 3.5-year longitudinal study. Subclinical malnutrition (i.e., overly low levels of prealbumin, relative risk [RR] = 4.01, p < 0.007), deficiency of vitamin A (RR = 3.23, p < 0.03), vitamin B12 deficiency (RR = 8.33, p < 0.009), zinc deficiency (RR = 2.29.1, p < 0.04), and selenium deficiency (RR = 19.9, p < 0.0001) over time, but not zidovudine treatment, were shown to each be associated with HIV-1-related mortality independent of CD4 cell counts <200/mm3 at baseline, and CD4 counts over time. When all factors that could affect survival, including CD4 counts <200/mm3 at baseline, CD4 levels over time, and nutrient deficiencies were considered jointly, only CD4 counts over time (RR = 0.69, p < 0.04) and selenium deficiency (RR = 10.8, p < 0.002) were significantly associated with mortality. These results indicate that selenium deficiency is an independent predictor of survival for those with HIV-1 infection.

Adult↗
PubMed1997

Survival after radical prostatectomy.

CONTEXT: The generalizability of currently available estimates of survival after radical prostatectomy is theoretically limited. OBJECTIVE: To obtain generalizable estimates of survival after radical prostatectomy. DESIGN: A population-based retrospective cohort study. SETTING: Nine regions of the United States. PATIENTS: Patients who were diagnosed with prostate cancer between 1983 and 1987 and underwent radical prostatectomy and lymph node dissection. MAIN OUTCOME MEASURES: Proportional hazards models incorporating geographical region, age, race, pathological stage, lymph node involvement, and tumor grade to identify independent correlates of disease-specific and overall survival and life table analyses to estimate 10-year survival distributions. RESULTS: A total of 3626 patients with a mean age of 65 years were included in the study; 92.6% were white, 54.2% had moderate-grade cancer, 60.4% had no extension beyond the prostate, and 91.2% had no lymph node involvement. Using San Francisco-Oakland, Calif, as a reference region, no other region was significantly associated with a risk of disease-specific or overall mortality. Older age and black race were independently associated with worse overall but not disease-specific survival. Higher grade, extension beyond the prostate, and lymph node involvement were independently associated with worse disease-specific and overall survival. Estimates of 10-year disease-specific survival ranged from 75% to 97% for patients with well-differentiated and moderately differentiated cancers and from 60% to 86% for patients with poorly differentiated cancers. CONCLUSIONS: Neither disease-specific nor overall survival varied by region, suggesting geographically uniform assessments of risk in patient selection for radical prostatectomy. Across regions, overall survival varied by patient and prostate cancer characteristics while disease-specific survival varied substantially by prostate cancer but not patient characteristics. The present analyses provide the most generalizable current estimates of survival after radical prostatectomy.

Aged↗
PubMed1997

Functional magnetic resonance imaging in schizophrenia: initial methodology and evaluation of the motor cortex.

The purpose of the present study was to evaluate the differential activation of the motor cortex during finger tapping in patients with schizophrenia using the newly available imaging method of functional magnetic resonance imaging (fMRI). Nine patients with DSMIII-R schizophrenia and 9 well-matched healthy volunteer subjects underwent fMRI examination on a conventional MR unit; activation of the primary motor cortex was evaluated during performance of a finger motion task. Localized activation of the motor cortex was observed in 17 of 18 subjects during fMRI. Patients and controls were, however, indistinguishable with respect to signal intensity or area thereof within the motor cortex. fMRI did not reveal motor cortical dysfunction in schizophrenia. Despite its infancy, fMRI holds considerable promise to advance understanding of the neurodynamics of psychiatric disorders, particularly schizophrenia.

Adult↗
PubMed1997

Loss of retinoblastoma gene function and heterozygosity at the RB locus in renal cortical neoplasms.

Alteration of the retinoblastoma (RB) gene, located on chromosome 13q14, has been implicated in the pathogenesis and biological behavior of several human cancers. We investigated the RB gene status by Western blotting and immunohistochemical analysis, as well as loss of heterozygosity (LOH) at the RB locus in 21 primary human renal neoplasms (including 3 oncocytomas). In only 1 of 21 tumors was there a discrepancy between Western blot and immunochemical staining. Overall, LOH was noted in 6 of 12 informative cases. However, only one of the tumors with LOH at the RB locus had loss of RB protein expression by both Western blot and immunohistochemical analysis. Loss of RB function was found in 4 of 18 carcinomas and in none of 3 oncocytomas as determined by absent RB nuclear staining in tumor cells. LOH at chromosome 13q14 was more noted in high-grade, DNA aneuploid, high-stage tumors and in patients with poor outcome. These results imply that (1) there is likely another tumor-suppressor gene on chromosome 13 involved in renal carcinogenesis, (2) LOH at chromosome 13q loci may be associated with aggressive behavior, and (3) the loss of RB function may have a role in a subset of renal carcinomas.

Adult↗
PubMed1997

HLA-DM polymorphisms do not associate with multiple sclerosis: an association study with analysis of myelin basic protein T cell specificity.

The MHC region on 6p harbors at least one susceptibility gene for multiple sclerosis (MS). Within this region, HLA-DM loci are of interest being involved in class II antigen processing. We investigated the association of HLA-DM polymorphisms with MS. Sixty-three patients with MS and 46 healthy controls from continental Italy were typed for HLA-DM polymorphisms and HLA-DRB1 alleles. Besides, among the donors characterized for the DM polymorphisms, we considered 6 MS patients previously studied for the fine specificity of their MBP-specific T lymphocyte lines (TLL). The frequencies of allelic variants at the DMA and DMB loci were similar between MS patients and controls, even when HLA-DRB1*1501 positive and negative donors were analyzed separately. Patients with predominant responses to different MBP epitopes did not differ for their HLA-DM haplotype while patients with predominant responses to the same MBP epitope could present different HLA-DM haplotypes. HLA-DM polymorphisms do not associate with MS and may not affect specific patterns of T cell responses to MBP.

Adult↗
PubMed1997

Intraimage reproducibility of measurements in the macular area using a computerized system.

An accurate analysis of the morphological changes which take place during pathological processes of the posterior pole is important for a correct diagnosis and therapeutic approach. The purpose of the study was to determine the intraobserver and interobserver reproducibility of the Image-net system 100 (Topcon, Japan) to take measurements on the retina. The program 'Linear/Areal Measurement functions' of Image-net system 100 which is an image digitalization technique, was tested. Twelve patients were consecutively selected from the patients of the Retina Center of the Department of Ophthalmology, University of Genoa. Three images of each eye were taken from each subject and only the best image was used in this study. The intraobserver and interobserver reproducibility of both the distance between two pre-set points (linear measurement), and the perimeter and area of preselected retinal zones were calculated. The repeatability (or intraobserver reproducibility) of the linear sizes was measured by the coefficient of variation and ranged from 0.32% to 7.38%, while the interobserver reproducibility ranged from 0.46% to 5.22%. The repeatability and reproducibility of the perimeters ranged from 0.72% to 9.63% and from 0.6% to 5.7%, respectively, while the repeatability and reproducibility of the areas ranged from 0.72% to 9.63% and from 0.6% to 5.7%, respectively. Although the results were quite good, the quality of the image of the fundus and the number of observers influenced the coefficient of variation; furthermore, the anatomy of the areas to be measured and the computer 'mouse' could increase the value of the coefficient of variation.

Angiography, Digital Subtraction↗
PubMed1997

Multidrug-resistant gene expression in small-cell lung cancer.

The development of drug resistance can contribute to treatment failure in small-cell lung cancer (SCLC). In this report, we investigate p-glycoprotein-mediated multidrug resistance (MDR) in these patients. Tumor tissue was obtained prior to treatment and at relapse if possible, short-term culture was carried out, and these tumor cells were analyzed for MDR gene expression by slot blot and reverse transcriptase polymerase chain reaction (RT-PCR) and northern blot analysis. Three cell lines were also established from short-term cultures. Twenty-four patients with MDR(-) and seven with MDR +(++) were available for survival analysis. Median survival for MDR (-) patients was 10 months, whereas for MDR +(++) patients it was 2 months. This was statistically significance (p < 0.0007). The presence of MDR1 gene expression also correlated with the lack of response to chemotherapy (p < 0.001). Increased MDR1 gene expression is usually present in patients with more tumor burden at initial diagnosis. Furthermore, loss of MDR1 gene expression can occur in intrinsically MDR(+) SCLC cells after multiple passages in drug-free media. We concluded that increased MDR1 gene expression is present in a small number of SCLC both before and after chemotherapy and usually signifies poor survival and no response to chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Competing risks of mortality in prostate cancer.

PURPOSE: We have observed that in prostate cancer older age, black race, high stage and no treatment are independently associated with higher disease specific and overall mortality. Because disease nonspecific mortality was not examined one cannot reasonably infer that higher overall mortality is largely due to higher disease specific mortality. To understand better the interactions of independent prognostic variables with overall mortality we jointly evaluated their effects on type of death and time to death. MATERIALS AND METHODS: Using the prostate cancer patients of the 1973 to 1990 public use tape of the Surveillance, Epidemiology and End Results program, we performed competing risks analysis with multivariate accelerated failure time model to examine if the prognostic factors were associated with type of death and time to death. RESULTS: Older age, black race and no treatment were independently associated with higher relative risk of disease specific and nonspecific mortality. Localized stage was associated with lower and higher disease specific and nonspecific mortality than regional stage, respectively. The relative risks of disease specific and nonspecific mortality were significantly different from each other for all prognostic factors. CONCLUSIONS: To our knowledge, a competing risks analysis in prostate cancer has not been done previously. While all prognostic factors were associated with disease specific and nonspecific mortality, the relative contribution of disease specific and nonspecific mortality to overall mortality varied by prognostic factor, with some prognostic factors associated with relatively high disease specific mortality while others were associated with relatively high disease nonspecific mortality. The similarity of the associations of age, race and treatment with disease specific and nonspecific mortality suggests that they mark an unidentified factor(s) that affects patient health nonspecifically. Such a factor(s) may partly or completely explain the association of treatment with lower disease specific mortality.

Aged↗
PubMed1997

[A comparative study of skeletal cephalometric of normal occlusion between the middle-old-aged and young people].

In this study the skeletal cephalometric data of normal occlusion between 39 middle-old-aged people and 30 young people were compared. The results indicated: the growth and reconstruction of the skeletal tissues of skull and jaws and face could still maintain for a period of time after grown-up. It mainly showed that skeletal tissues increased in vertical direction, the declination of occlusion plane became flat along with the increasing of ages.

Adult↗