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Biomedical subjects

L Joseph

Publications and source records attributed to L Joseph.

At least 145 records · Page 8Linked to original sources
PubMed1993

The pathogenesis and prognosis of lupus nephritis: information from repeat renal biopsy.

Of an inception cohort of 87 patients with lupus nephritis who underwent a renal biopsy, 42 underwent second biopsies a median of 25 months later. From first to second biopsy, focal and diffuse proliferative nephritis (World Health Organization classes III and IV) became less frequent, and mesangial hypercellularity (class II) and a membranous pattern (class V) increased. The National Institutes of Health activity index and mesangial and subendothelial deposits declined while the chronicity index, a tubulointerstitial index, and subepithelial deposits increased. The biopsy improvement in urinary protein excretion was best explained by decreases in the activity index score and the amount of subendothelial deposits. A decrease in the amount of subendothelial deposits tended to predict an improvement in the serum creatinine level from first to second biopsy. With follow-up from second biopsy in excess of 7 years, the best predictors of long-term outcome were the ultrastructural variables mesangial, subendothelial and subepithelial deposits. When the change in biopsy predictors from first to second biopsy was evaluated, a decrease in the amount of mesangial or subendothelial deposits was best at predicting a lower risk of renal impairment, renal insufficiency, and mortality. The results confirm the importance of immune complex deposition as measured by electron microscopy in the pathogenesis of lupus nephritis and suggest that control of this process may alter renal function and prognosis.

Biopsy↗
PubMed1993

Phylogeny and historical aspects of the ecology of eastern Australian scrubwrens Sericornis spp.--evidence from mitochondrial DNA.

A phylogeny of mainland eastern Australian scrubwrens (Sericornis citreogularis, S. frontalis, S. keri, S. magnirostris and S. beccarii) was constructed using presence or absence of phylogenetically informative restriction sites in 15 mitochondrial DNA (mtDNA) haplotypes. MtDNA sequence divergences between species were generally large (mostly between 10 and 18%) emphasizing the antiquity of this radiation. Phylogenetic analysis of the mtDNA resulted in a strongly supported phylogeny concordant with relationships suggested by a previous study of allozyme variation, but conflicting with concepts based on morphological similarity. The mtDNAs grouped the species into two lineages, one containing beccarii and magnirostris and the other comprising citreogularis, frontalis and keri. The mtDNAs of beccarii and magnirostris were paraphyletic with a northern variant of magnirostris being more similar to beccarii than other magnirostris. The mtDNA from keri was most closely related to that of frontalis and then citreogularis. The strongly corroborated molecular phylogeny confirms and extends the previous (Christidis et al. 1988; Auk 105: 616) reinterpretation of morphological and ecological shifts in the group. This suggests considerable plasticity and parallelism in the plumage characters previously used to associate species. The low divergence and close relationship between the montane rain-forest specialist keri and the widely distributed generalist frontalis demonstrate the capacity for evolutionarily rapid and dramatic shifts in habitat use. This contrasts with the assumption of fixed habitat preference that underlies refuge-based models of diversification of rain-forest fauna.

Animals↗
PubMed1993

Multilocular cystadenoma of the liver with mural nodules.

Hepatobiliary cystadenoma, characterised by the interposition of a mesenchymal stroma beneath the epithelium and the connective tissue layer, is a tumor described exclusively in women. These tumors have a potential for malignant transformation. Complete surgical excision is mandatory. We report a case cystadenoma with mesenchymal stroma (CMS), with mural nodules in the cyst wall, similar to those described in ovarian mucinous cystadenoma.

Cystadenoma↗
PubMed1993

Chest radiographs as a screening test for diffuse idiopathic skeletal hyperostosis.

OBJECTIVE: To evaluate the sensitivity, specificity, predictive value, interrater reliability and intrarater reliability of using chest radiographs as a screening tool for the diagnosis of diffuse idiopathic skeletal hyperostosis (DISH). METHODS: After review of thoracic spine radiographs by 2 "gold standard" physicians, 45 patients with DISH meeting the criteria of Resnick and Niwayama were contrasted with 106 control patients consisting of 45 with thoracic spondylosis, 45 who lacked spondylosis and whose thoracic spine radiographs were otherwise normal for the age of the patient, and 16 with ankylosing spondylitis. The chest radiographs on the 151 subjects were placed in random order and read independently using an ordinal diagnostic certainty scale by 2 "test" radiologists, experienced in reading bone radiographs. Two months later the order of chest radiographs was rerandomized and the films reassessed by the same test radiologists. RESULTS: The averages for the diagnostic and population test characteristics were sensitivity = 77%; specificity = 97%; positive predictive value = 91%; and, negative predictive value = 91%. The area under the receiver operating characteristic curves was 0.975 and 0.976 for the radiologists, and kappa was 0.93, demonstrating that interrater reliability was high. On rereading the chest radiographs, intrarater reliability was exceptional (weighted kappa of 0.90 and 0.96 for the two test radiologists). DISH patients whose chest radiographs were read as not demonstrating DISH had significantly less extensive disease. CONCLUSIONS: We conclude that chest radiographs are a reliable and valid screening tool for the diagnosis of DISH.

Adult↗
PubMed1993

Antimalarial drug utilization by women in Ethiopia: a knowledge-attitudes-practice study.

A survey was undertaken between December 1991 and February 1992 to assess the knowledge, attitudes, and practices with respect to malaria of 300 women from six randomly selected rural communities in central Ethiopia. A total of 85% were able to recognize one or more of the common symptoms of the disease; however, the modes of transmission were generally misunderstood and only 23% believed that transmission could be prevented. More women preferred to obtain antimalarials from government clinics rather than from private drug shops, mission clinics, unofficial suppliers of injections, open markets, or from leftover sources. Under-5-year-olds were identified as the most malaria-vulnerable group and given priority for treatment; severity of illness was the principal determinant in seeking treatment. Decisions about treatment were generally made jointly by both parents. Knowledge about the transmissibility of malaria decreased with increasing distance from a health unit (odds ratio: 0.48; 95% confidence interval: 0.27, 0.86). A logistic regression analysis indicated that literacy and village were the most important variables associated with knowledge about preventing malaria.

Adolescent↗
PubMed1992

The benefits of treating hyperlipidemia to prevent coronary heart disease. Estimating changes in life expectancy and morbidity.

OBJECTIVE: To evaluate the lifetime benefits of reducing total serum cholesterol levels to prevent coronary heart disease (CHD). DESIGN: We developed a CHD primary prevention computer model to estimate the benefits associated with lifelong risk factor modification. We validated the model by comparing the computer estimates with the observed results of three primary CHD prevention trials. PATIENTS: Men and women age 35 to 65 years who are free of CHD, with total serum cholesterol levels ranging from 5.2 to 7.8 mmol/L (200 to 300 mg/dL), with or without additional CHD risk factors. INTERVENTIONS: Serum cholesterol reduction through dietary modification or diet and medications. MAIN OUTCOME MEASURES: Changes in life expectancy and the delay of symptomatic CHD. RESULTS: The computer forecasts for CHD end points closely matched the observed results of the Lipid Research Clinics Trial, the Helsinki Heart Study, and MRFIT. We then applied the computer model to low-risk and high-risk men and women with total serum cholesterol levels between 5.2 and 7.8 mmol/L (200 and 300 mg/dL) and estimated that, after reducing serum cholesterol levels 5% to 33%, the average life expectancy would increase by 0.03 to 3.16 years. We also forecast that the average onset of symptomatic CHD would be delayed among these patient groups by 0.06 to 4.98 years. CONCLUSION: We conclude that this computer model accurately estimates the results of clinical trials and can be used to forecast the changes in life expectancy and morbidity (the development of CHD) associated with specific CHD risk reduction interventions. The wide variation surrounding these estimates underscores the need to better define which groups of individuals will gain the most from cholesterol reduction.

Adult↗
PubMed1992

Phospholipid composition of cultured human endothelial cells.

Detailed analyses of the phospholipid compositions of cultured human endothelial cells are reported here. No significant differences were found between the phospholipid compositions of cells from human artery, saphenous and umbilical vein. However, due to the small sample sizes, relatively large standard deviations for some of the phospholipid classes were observed. A representative composition of endothelial cells is: phosphatidylcholine 36.6%, choline plasmalogen 3.7%, phosphatidylethanolamine 10.2%, ethanolamine plasmalogen 7.6%, sphingomyelin 10.8%, phosphatidylserine 7.1%, lysophosphatidylcholine 7.5%, phosphatidylinositol 3.1%, lysophosphatidylethanolamine 3.6%, phosphatidylinositol 4,5-bisphosphate 1.8%, phosphatidic acid 1.9%, phosphatidylinositol 4-phosphate 1.5%, and cardiolipin 1.9%. The cells possess high choline plasmalogen and lysophosphatidylethanolamine contents. The other phospholipids are within the normal biological ranges expected. Phospholipids were separated by high-performance liquid chromatography and quantified by lipid phosphorus assay.

Cell Extracts↗
PubMed1992

Underfeeding and body weight regulation in normal-weight young men.

The mechanisms of energy regulation invoked by moderate dietary restriction were investigated in seven healthy young men of normal body weight leading unrestricted lives. Following a baseline period of weight maintenance, subjects were underfed by 806 +/- 162 (mean +/- SE) kcal/day for 21 days. Changes in total energy expenditure (TEE) and resting energy expenditure (REE) and subsequent voluntary nutrient intakes were measured. The REE, averaged for fasting and fed states, decreased during underfeeding by 100 +/- 29 kcal/day (P less than 0.01). TEE decreased nonsignificantly by 296 +/- 170 kcal/day, equivalent to an average of 37% of the decrease in energy intake. Body energy stores were estimated to decrease by 510 +/- 172 kcal/day (P less than 0.03), thus compensating for 63% of the dietary energy deficit on average. Voluntary energy intake following dietary restriction increased above the initial amount required for body weight maintenance, was proportional to the weight loss during underfeeding (P less than 0.03), and was associated with a rapid regain of weight lost during underfeeding. These results indicate that energy balance is regulated by adaptive variations in both energy intake and energy expenditure in normal-weight young men leading unrestricted lives but do not support the hypothesis that energy-wasting mechanisms contribute substantially to body energy regulation.

Adult↗
PubMed1992

[Psychological distress in persons afflicted with HIV in Montreal].

This paper describes the HIV-related mental health concerns of a sample of 128 persons with HIV infection in Montréal who participated in a larger national survey of HIV-related mental health needs and services in Canada. We examined mental health distress in persons with HIV infection in Montréal compared to other cities in Canada, and in subgroups of HIV-infected Montrealers defined on the basis of sex, age, diagnosis, and risk factor status. Results demonstrate that although HIV infection has a strong and far reaching impact on mental health, there are differences in the types of concerns and issues that are distressing to specific groups of Montréal respondents. Uncertainty about the future and not being able to realize life goals, as well as feelings of helplessness and fears about potential adverse neurological consequences of HIV disease, were major sources of psychological distress. Feelings of depression, anxiety, and anger, as well as concerns about increasing physical disability, pain, infecting others, confidentiality, and finances were predominant concerns among specific subgroups. Differences between respondents in terms of source of income, age, and sex, and to a lesser extent diagnosis and risk factor status, were associated with varying levels of mental health distress. Although respondents in Montreal (and Vancouver) were more distressed than respondents in Toronto and Halifax, these differences appear to be due primarily to differences in age and source of income. Findings from this study will be useful to policy makers and health planners in developing services to meet the mental health needs of HIV infected adults.

Adolescent↗
PubMed1991

Accelerated fractionation for high-grade cerebral astrocytomas. Preliminary treatment results.

A Phase I/II accelerated fractionation study for high-grade cerebral astrocytomas began in October 1987. Forty-two patients, 25 men and 17 women, were entered in the study. Median age was 58.5 years of age (range, 32 to 78 years). Performance status was 0, 1, 2, and 3 on Eastern Cooperative Oncology Group (ECOG) scale for 13, 19, 9, and 1 patients, respectively. Thirty-six patients had undergone partial resection, and six had stereotactic biopsy only. All patients had histologically proven astrocytomas (6 Grade 3, and 36 Grade 4). Treatment consisted of radiation therapy doses of 4400 cGy in 22 daily fractions to the whole brain plus a boost of 1600 cGy in 8 fractions given concomitantly with the last 8 whole-brain treatments using a twice daily schedule with an interfraction interval of 8 hours. Median survival time was 57 weeks from the date of starting irradiation. Survival was 50% and 28% at 1 and 2 years, respectively. Alopecia and scalp erythema were seen in all patients; nine patients had localized areas of moist desquamation in the retroauricular region. Decreased hearing and serous otitis media were seen in five patients within 1 to 2 months from the end of treatment. Increasing somnolence was marked in eight patients with progressive deterioration of performance status; computerized axial tomography (CAT) scan studies in all eight patients showed evidence of disease recurrence with associated brain edema and mass effect. Three patients had a second resection for a recurrent tumor with no evidence of brain necrosis at craniotomy. To date, the accelerated fractionation schedule appears to be well tolerated with valuable shortening of overall treatment time. The preliminary results are encouraging, and longer follow-up time is required to evaluate tumor control and toxicity.

Adult↗
PubMed1990

Early detection and treatment of hyperlipidemia: physician practices in Canada.

We surveyed primary care physicians in Canada to determine their current practices regarding the detection and treatment of hyperlipidemia in asymptomatic adults 20 years of age or more and to determine the role of selected patient characteristics (age, sex and the presence of coronary heart disease [CHD] risk factors) in their management decisions. The self-administered questionnaire was completed by 428 of 804 family physicians and general practitioners. The proportion of physicians who reported having tested at least 50% of their adult patients varied from 29% to 85% and was related to the number of CHD risk factors present and the patient's age. The proportion of respondents who reported starting dietary or drug therapy among patients with a cholesterol level of 6.2 mmol/L or less increased as the number of CHD risk factors increased and was not related to patient age or sex. According to the factors examined our results suggest that primary care physicians in Canada select patients for screening and treatment mainly on the basis of CHD risk factors present and that their approach is more conservative than that recommended by the Canadian and US consensus conferences.

Adult↗
PubMed1990

Molecular mapping of the mouse db mutation.

Diabetes (db) is an autosomal recessive mutation located in the midportion of mouse chromosome 4 that results in profound obesity with hyperphagia, increased metabolic efficiency, and insulin resistance. To clone this gene and generate a molecular map of the region around this mutation, two genetic crosses were established: an intraspecific backcross between C57BL/6J db/db females and C57BL/6J db/db x DBA/2J +/+ F1 (B6D2 db/+ F1) male mice and an interspecific intercross between B6D2 db/+ F1 males and C57BL/6J db/db x Mus spretus F1 (B6spretus db/+ F1) females. The progeny of both crosses were characterized for genotype at the db locus to map a series of restriction fragment length polymorphisms relative to the db locus. Measurements of body weight, body length, and plasma concentrations of glucose and insulin in the animals allowed the assignment of genotype (db/db vs. db/+ or +/+). A total of 132 progeny of the intraspecific cross and 48 db/db progeny of the interspecific cross were typed for individual restriction fragment length polymorphisms to generate a gene order of: centromere-brown (Mt4)-P lambda Mm3(2)-Ifa (Inta)-Cjun-db-D4Rp1-Glut1-Mtv-13-Lck. Several of the genes that are linked to db [Cjun, glucose transporter (Glut1) and Lck] map to human chromosome 1p, suggesting that db may be part of a syntenic group between human 1p and the distal portion of mouse chromosome 4. In addition, phenotyping of the progeny of these crosses revealed a wide range in plasma concentrations of glucose and insulin among the obese progeny, with some animals developing overt diabetes and other remaining euglycemic. Distributions of age-controlled plasma [glucose] and [insulin] among the intraspecific-cross obese progeny were not bimodal, suggesting a role for polygenic differences between the progenitor strains (C57BL/6J and DBA/2J) in the development of overt diabetes.

Animals↗
PubMed1990

Energy expenditure and subsequent nutrient intakes in overfed young men.

We investigated the mechanisms of body weight regulation in young men of normal body weight leading unrestricted lives. Changes in total and resting energy expenditure, body composition, and subsequent voluntary nutrient intakes in response to overeating by 4,230 +/- 115 (SE) kJ/day (1,011 +/- 27 kcal/day) for 21 days were measured in seven subjects consuming a typical diet. On average, 85-90% of the excess energy intake was deposited (with 87% of this amount in fat and 13% in protein on average). There was no detectable difference between individuals in susceptibility to energy deposition. The resting metabolic rate, averaged for fasting and fed states, increased during overfeeding (mean +/- SE, 628 +/- 197 kJ/day, P less than 0.01), but at least some of this amount was obligatory expenditure associated with nutrient assimilation. No significant increase in energy expenditure for physical activity or thermoregulation resulted from overfeeding. Thus energy expenditure did not substantially adapt to increased energy intake. However, significant decreases in voluntary energy intake (1,991 +/- 824 kJ/day, P less than 0.05) and fat intake (48 +/- 11 g/day, P less than 0.01) followed overeating, indicating that adaptive changes in nutrient intakes can contribute significantly to body weight regulation after overeating.

Adult↗
PubMed1990

Is multiple sclerosis an infectious disease? Inference about an input process based on the output.

The output process of an infinite-server queue with a Poisson process input is observed starting at time 0 with an empty queue. It is assumed that the service time distribution is known. This article discusses statistical inference about the input intensity. A controversial issue in the study of multiple sclerosis is addressed as a motivation for the model and methods developed.

Adolescent↗
PubMed1989

Smoking--the effects on cerebral vascular circulation. A variable in patient decision making.

Stroke, caused by either infartion or subarachnoid haemorrhage, can have devastating and debilitating effect on its victims. Traditional therapy has focused on the risk factors of hypertension, hyperlipidemia, atherosclerotic heart disease and diabetes milletus. More recently, the literature has focused on smoking and the short and long term effects of cerebral blood flow. The purpose of this paper will be to review the most recent research literature on both the chronic and acute effects of smoking on the cerebral vascular system. More specifically, there will be an examination of the effect of smoking on the outcome of a carotid endarterectomy, subarachnoid haemorrhage and the progression of atherosclerosis. Smoking is harmful and its cumulative effects, along with additive effects must be recognized. Despite increased risk, people continue to smoke affecting disease progression and treatment. Two models will be discussed--the health belief model and the health decision model. These models can provide a basis for nursing to develop and assess comprehensive smoking cessation programmes.

Carotid Artery Diseases↗
PubMed1988

Psychiatric disorders in adopted children: a controlled study.

The number of adopted children referred to a Canadian psychiatric service was found to be greater than warranted by their ratio in the community. They presented more with conduct disorders and less with anxiety disorders and were significantly more impaired than the controls.

Adolescent↗