Biomedical subjects
L Williams
Publications and source records attributed to L Williams.
Rates of progression to end stage renal failure in nephropathy secondary to type 1 and type 2 diabetes mellitus.
BACKGROUND: Diabetic nephropathy is now the commonest single cause of end-stage renal failure (ESRF) in New Zealand. AIMS: To investigate differences in the natural history of established nephropathy in Type 1 and 2 diabetes. METHODS: Retrospective analysis of the rate of progression to ESRF in 17 subjects with Type 1 diabetes (predominantly European) compared to 29 subjects with Type 2 diabetes (all Polynesian). The rate of decline of renal function was determined from serial creatinine measurements (median 5, range 3-8) during progression of chronic renal failure to end stage. Glomerular filtration rate (GFR) was estimated from creatinine measurements using the Cockcroft Gault equation, and the regression slope of these measurements against time was used to determine rate of change of renal function. RESULTS: GFR fell significantly more rapidly in the group with Type 2 diabetes than in those with Type 1 diabetes: median 1.7 (interquartile range 1.2 to 2.3) mL min-1 month-1 vs 1.1 (interquartile range 0.4 to 1.5) mL min-1 month-1, p = 0.017. During the study period the mean reduction in diastolic blood pressure in subjects with Type 1 diabetes (15 mmHg) was greater than that in the Type 2 subjects (8 mmHg), but the stage at which antihypertensives were commenced was similar in the two groups. Glycaemic control was worse in the subjects with Type 1 diabetes (p < 0.005). The differences in blood pressure control were not significant on analysis of covariance which indicated that ethnicity was the major determinant of the different rates of decline of GFR between the groups. We conclude that in subjects with diabetic nephropathy the rate of progression to ESRF is more rapid in Polynesians with Type 2 diabetes than in Europeans with Type 1 diabetes. This could contribute to the apparent excess of Type 2 diabetic subjects of Polynesian origin on renal replacement programmes in New Zealand.
Relation of boron to the composition and mechanical properties of bone.
A review of the experimental studies relating boron to biological effects on appendicular and axial bones in animal models suggests that numerous influences, known and unknown, affect the responsiveness of bone to dietary boron. Degrees of skeletal response to boron are modified by other nutritional variables that include calcium, magnesium, vitamin D, and fluoride. Evidence suggests that appendicular and axial bones may differ in their responses. Tests of the mechanical properties of bones may provide useful criteria for assessing the impacts of boron status on bone. These tests might resolve questions about optimal intakes of boron because mechanical properties sometimes respond to boron when composition of bones does not. Difficulty in interpreting some of the existing research arises because of the incipient state of knowledge regarding boron nutriture, to analytical problems associated with determining accurately the small quantities of boron in feed and tissues, and to technological difficulties in controlling extraneous exposure of experimental animals to boron. Yet there is considerable evidence that both compositional and functional properties of bone are affected by boron status.
Seroprevalence of human T-lymphotropic virus in blacks from a selected central Brooklyn population.
Human T-cell leukemia virus type I (HTLV-I) has been causally linked to adult T-cell leukemia/lymphoma and tropical spastic paraparesis/HTLV-I-associated myelopathy. Few seroprevalence studies have been carried out in the United States. Because of the number of reports of adult T-cell leukemia/lymphoma and tropical spastic paraparesis/HTLV-I-associated myelopathy in blacks from central Brooklyn, New York, we decided to initiate a seroprevalence study in this community. Intravenous drug users and male homosexuals were excluded. A total of 480 individuals from medical clinics and health fairs were surveyed via questionnaire, and their sera were assayed for HTLV-I/II antibody by two laboratories. An overall seroprevalence rate was 21/480 (4.4%). This is almost 200 times greater than a study of a national sample of U.S. blood donors. Rates were similar for individuals originating from the United States and the Caribbean. Nine of the 21 seropositive individuals returned for further testing. Polymerase chain reaction assays revealed that 8 were positive for HTLV-I and 1 for HTLV-II. Although this group may not be representative of the "normal" black population of central Brooklyn, the high seroprevalence rate necessitates that the incidence of HTLV-I-associated illnesses be determined in this community.
Psychosocial, alcohol/other drug use, and delinquency differences between urban black and white male high risk youth.
Using data collected on 286 Black and White male youths entering a juvenile detention center, we examine differences in their psychosocial functioning, substance use, and delinquency/crime. Comparison is made on a wide range of variables, including sociodemographic characteristics, family problems, records of contact with the juvenile court, physical abuse or sexual victimization history, alcohol/other drug use, friends' involvement in substance use and crime, and emotional/psychological functioning problems. Implications of the results for understanding the youths' involvement in the juvenile justice system, and for the development of, and linkage with, appropriate services, are drawn.
The relationships among family problems, friends' troubled behavior, and high risk youths' alcohol/other drug use and delinquent behavior: a longitudinal study.
Data from an ongoing longitudinal study of juvenile detainees are used to test a structural model of the relationships among their alcohol/other drug use and other delinquent behavior, their family problems, and friends' troubled behavior. The hypothesized model fitted the data well. Implications of the results are drawn in regard to theory and program policy.
Cocaine selling among urban black and white adolescent males.
Data from a longitudinal study of juvenile detainees are used to examine the relationships between cocaine selling, substance use, and other delinquency among the Black and White males in the study. A descriptive comparison of rates of cocaine selling among the youths is followed by a descriptive comparison of prevalence of substance use and other delinquency across four subgroups: White and Black males indicating they sold and did not sell cocaine. These comparisons are followed by analyses of variance examining the relationships between involvement in substance use and other delinquency, and ethnicity, cocaine selling, and the interaction of ethnicity and cocaine selling. Important ethnicity and cocaine-selling effects are found, but not ethnicity by cocaine-selling interactions. The implications of our findings for theory and service provision are drawn.
Teleradiology in an urban setting.
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Death certification--a sad state of affairs.
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Influenza A virus infections among hospitalized adult bone marrow transplant recipients.
Although influenza virus continues to cause annual epidemics of respiratory diseases, surprisingly little is known about the frequency and clinical course of influenza among adult patients with cancer. During the 1991-92 influenza epidemic in Houston, Texas, we followed all adult BMT recipients hospitalized at M.D. Anderson Cancer Center. None of these 68 patients had received prophylaxis for influenza. Influenza virus type A was isolated from 8 (29%) of 28 BMT recipients with an acute respiratory illness. Five of these infections were acquired in the hospital. All 8 patients presented with an upper respiratory tract illness. In 6 patients, the infection was complicated by pneumonia. The frequency of influenza was similar among autologous (5 of 18) and allogeneic (3 of 10) BMT recipients. The risk of developing pneumonia was not related to the type of transplant or to the engraftment status. All patients received broad-spectrum antibiotics. The 2 patients who did not develop pneumonia also received amantadine. The mortality with pneumonia was 17%. During community outbreaks, influenza is a frequent cause of acute respiratory illness among hospitalized adult BMT recipients and is frequently complicated by pneumonia. Studies are needed to define the optimal means of preventing and treating influenza in BMT recipients.
Organization of the commissural fibers in the adult brain of the locust.
The brain (supraoesophageal ganglion) is the most complex of the segmental ganglia composing the nerve cord of the locusts Schistocerca gregaria and Locusta migratoria. In this paper, we describe the ground plan of the commissures crossing the midline of the brain and propose a nomenclature with the aim of making a complex neuropil more understandable at the level of individual neurons. For developmental and comparative reasons the neuroarchitecture of the brain is related to the neural axis, not to the body axis. We have identified 73 commissural fiber bundles belonging to the adult brain, and these are named according to their location (ventral, dorsal, anterior, posterior, medial) with respect to the central complex as reference point. Reconstructions of identified neurons from intracellular stainings, cobalt backfills, or immunohistochemical studies demonstrate the various configurations in which fibers cross the brain.
Uridine allows dose escalation of 5-fluorouracil when given with N-phosphonacetyl-L-aspartate, methotrexate, and leucovorin.
BACKGROUND: In a previous trial in which methotrexate and N-phosphonacetyl-L-aspartate (PALA) were used to modulate 5-fluorouracil (5-FU), four of six patients could not tolerate treatment at the 600 mg/m2 5-FU dose level because of mucositis, diarrhea, and a decrease in performance status. The current study examines the ability of uridine rescue to prevent such toxic effects in the same regimen and, thereby, allow additional dose escalation of 5-FU. METHODS: Twenty-nine patients with advanced malignant neoplasms received PALA and MTX, each at 250 mg/m2, followed 24 hours later by increasing bolus doses of 5-FU (600-750 mg/m2) with a leucovorin rescue (10 mg orally every 6 hours for eight doses) and uridine rescue (3 g/m2/hour, for a 72-hour infusion, 3 hours on, 3 hours off). Treatment was repeated weekly with either 2 weeks on, 2 weeks off, or 3 weeks on, 1 week off. RESULTS: Mucositis, which occurred in 4 of 12 patients treated at the 750 mg/m2 5-FU dose level, was the only significant chemotherapy-induced toxic effect. However, uridine-related central venous catheter complications (cellulitis in six patients and superior vena cava syndrome in one patient) precluded additional treatment on this protocol. CONCLUSIONS: In the current regimen, uridine allowed dose escalation of 5-FU to 750 mg/m2, which some patients tolerated on a 3-week on, 1-week off schedule. Because of the vascular toxic effects associated with intravenous uridine, the authors recommend additional studies with oral uridine to determine whether the increase in 5-FU dose that uridine allows is associated with improved response rates.
Unique expression pattern of the FGF receptor 3 gene during mouse organogenesis.
The actions of fibroblast growth factors (FGFs) are mediated via a family of four closely related FGF receptor genes (FGFRs 1-4). FGFR1, FGFR2, and FGFR4 have unique patterns of expression during embryogenesis suggesting that these receptors mediate different functions of FGFs during development. In the present study, we used in situ hybridization analysis to show that FGFR3 also has a unique pattern of expression during organogenesis. Like FGFR1 and FGFR2, FGFR3 was expressed in the germinal epithelium of the neural tube (9.5-16.5 days pc). However, at 1 day postpartum and in the adult brain, FGFR3 was expressed diffusely and localized in cells with morphologic characteristics of glia, a pattern distinctly different from the discrete neuronal expression of FGFR1. FGFR3 was also expressed at high levels in differentiating hair cells of the cochlear duct, but was not detected in other sensory epithelia. Outside the nervous system, the highest level of FGFR3 expression was found in the cartilage rudiments of developing bone. During endochondral ossification, FGFR3 was expressed exclusively in resting cartilage, a pattern distinct from FGFR1 and FGFR2 which are also expressed during this process. Unlike FGFR1 and FGFR2, FGFR3 was not detected in most other epithelial or mesenchymal tissues during these stages of organogenesis. The unique expression pattern of FGFR3 compared with the other FGF receptors strongly suggests that FGFR3 performs specific functions during organogenesis.
The influence of food on the absorption and metabolism of drugs.
Food-drug interactions can lead to a loss of therapeutic efficacy or toxic effects of drug therapy. Generally, the effect of food on drugs results from a reduction in the drug's bioavailability; however, an alteration in drug clearance can occur due to the effect of certain foods on drug metabolism. The proportion of adverse drug reactions due to food-drug interactions is not known and unfortunately only when a serious adverse drug reaction follows a food-drug interaction does the matter usually receive any significant attention. In order to improve therapeutic efficacy and to help prevent adverse drug reactions, it is necessary that clinicians be knowledgeable of the important food-drug incompatibilities and risk factors related to the increased likelihood of developing an adverse drug reaction due to food-drug interactions.
Successful resuscitation from sea water drowning.
A case of a 24-year-old male who survived a near drowning despite suboptimal pre-hospital management is reported. The case illustrates the value of continuing resuscitative efforts even in the apparently dead drowning victim.
Recidivism in a cohort of juvenile detainees: a 3 1/2-year follow-up.
We report some results from a longitudinal study of juvenile detainees. In extending previous analyses, we sought to determine whether the youth's alcohol or other drug use and their emotional/psychological problems at entry into the detention center predicted subsequent arrests for new offenses during the 36 months and 42 months following their initial interviews. Statistically significant relationships were found between the youths' demographic characteristics (age, race, gender) and cocaine use at initial interview (as measured by urinalysis), and recidivism. The policy implications of these findings are discussed.