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Biomedical subjects

P Segal

Publications and source records attributed to P Segal.

At least 37 records · Page 2Linked to original sources
PubMed1991

The Wisconsin age-related maculopathy grading system.

A new system for grading age-related maculopathy is described and measures of reliability are reported. A number of characteristics of age-related maculopathy are graded in a semiquantitative fashion from stereoscopic 30 degrees color fundus photographs, using a grid to define subfields, standard circles printed on plastic to assess size and area, and a specially designed lightbox to allow better discrimination of subtle drusen. The degree of exact agreement achieved between two trained graders across a variety of lesions ranged from 67.1% for drusen size to 99.6% for geographic atrophy. Kappa scores ranged from 0.55 (for drusen confluence) to 0.95 for geographic atrophy. This system will be useful in epidemiologic studies and clinical trials.

Aging↗
PubMed1991

A common Lithuanian mutation causing familial hypercholesterolemia in Ashkenazi Jews.

Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the low-density-lipoprotein (LDL) receptor. Here we characterize an LDL-receptor founder mutation that is associated with a distinct LDL-receptor haplotype and is responsible for FH in 35% of 71 Jewish-Ashkenazi FH families in Israel. Sixty four percent (16/25) of the Ashkenazi patients who carry this mutant allele were of Lithuanian origin. The mutation was not found in 47 non-Ashkenazi FH families. This mutation was prevalent (8/10 FH cases) in the Jewish community in South Africa, which originated mainly from Lithuania. The mutation, a 3-bp in-frame deletion that would result in the elimination of Gly197, has been previously designated FH-Piscataway. PCR amplification of a DNA fragment that includes the mutation in heterozygous individuals results in the formation of a heteroduplex that can be demonstrated by PAGE and used for molecular diagnosis.

Alleles↗
PubMed1990

Maternal serum lipid profile in pregnancies complicated by hypertensive disorders.

Plasma lipoprotein, cholesterol and triglycerides were determined in 34 hypertensive pregnant patients and in 17 healthy full term pregnant women. Pregnancy induced hypertension was diagnosed in 21 patients and chronic hypertension in the remaining 13 women. Serum triglyceride levels were significantly elevated in the hypertensive patients. This elevation was not influenced by either the severity or the etiology of the hypertension. The total cholesterol/HDL and the LDL/HDL ratios were significantly elevated in the severely hypertensive patients, and furthermore the LDL/HDL ratio was elevated in patients receiving anti-hypertensive treatment. The lipid profiles found in hypertensive pregnant patients could be associated with enhancement of pathological lipid deposition in predisposed vessels such as the uterine spiral arteries. Furthermore, the hypertriglyceridemia found in the hypertensive patients may be associated with the hypercoagulability reported in pregnancy induced hypertension.

Cholesterol↗
PubMed1990

The association of corneal arcus with coronary heart disease and cardiovascular disease mortality in the Lipid Research Clinics Mortality Follow-up Study.

The relationship between corneal arcus (arcus senilis) and mortality from coronary heart disease (CHD) and cardiovascular disease (CVD) is examined in a prospective study of White men (n = 3,930) and women non-hormone users (n = 2,139), ages 30-69, followed for an average of 8.4 years as part of the Lipid Research Clinics Mortality Follow-up Study. After excluding those with clinically manifest CHD at baseline, corneal arcus was strongly associated with CHD and CVD mortality only in hyperlipidemic men ages 30-49 years, for whom the relative risk for CHD and CVD death was 3.7 and 4.0, respectively, after adjusting for age, total cholesterol, HDL cholesterol, and smoking status using a Cox proportional hazards model. Among 30-49 year old males, corneal arcus appears to be a prognostic factor for CHD, independent of its association with hyperlipidemia in this age-group, of about the same magnitude as other common risk factors, underscoring the usefulness of corneal arcus as a prognostic factor to the practicing clinician.

Adult↗
PubMed1987

Do beta-blockers alter lipids and what are the consequences?

The unpredictable effect of antihypertensive therapy on coronary risk resulting from changes in lipid levels is an increasingly recognized problem. Different drugs have been shown to exert varying effects on lipids. This problem is particularly evident in young hypertensive patients who may be candidates for lifelong therapy. The effects of chlorthalidone and metoprolol on fasting plasma lipids and lipoprotein levels were compared in two similar nonrandomized groups of patients with mild hypertension. Chlorthalidone therapy was associated with an increase in serum cholesterol of 8.1% (17 mg/dl), mainly reflecting an increase in low-density lipoprotein (LDL) cholesterol. Serum triglycerides increased by 16% (20 mg/dl) and high-density lipoprotein (HDL) cholesterol levels decreased by 10% (3 mg/dl, not significant). Metoprolol therapy induced no changes in total, low, very low, or high-density lipoprotein. Serum triglyceride concentration increased by 22% (28 mg/dl). Application of the Israel Ischemic Heart Disease Study data to these findings indicates a slight decrease at most in the 5-year estimated probability of myocardial infarction in the chlorthalidone-treated group, whereas a clearly favorable influence on the calculated risk of coronary heart disease was observed for those treated with metoprolol. These data suggest that the different forms of therapy for mild hypertension carry varying degrees of significance in terms of risk of coronary heart disease, which should be considered when choosing medication.

Adrenergic beta-Antagonists↗
PubMed1987

Hyperinsulinemia--a link between glucose intolerance, obesity, hypertension, dyslipoproteinemia, elevated serum uric acid and internal cation imbalance.

A representative sample (n = 1211) of the Jewish population in Israel age 40-70 (excluding known diabetics), underwent a glucose tolerance test. Insulin response was found to be independently and positively associated with the GOH conditions--glucose intolerance (p less than 0.001), obesity (p less than 0.001), and hypertension (p less than 0.01) and with elevated serum uric acid (p less than 0.001) after accounting for the effects of sex, age, serum creatinine and use of antihypertensive medications. In a representative subgroup of 542 individuals, total VLDL and LDL fractions were estimated by standardized values (based on the reference group--individuals free of the GOH conditions), of their cholesterol and triglyceride components. Hyperinsulinemia was characterized by jointly elevated VLDL and LDL with reduced HDL. The risk ratio for this pattern (adjusted for the effects of age, sex, smoking and presence of any of the GOH conditions) was 3.4 (p less than 0.001). There was no further association of this disturbed lipoprotein profile with the GOH conditions. Cation concentrations were determined in a stratified subsample (n = 89) of the study group. The subsample comprised 30 individuals in the reference group, and 59 representing each of the seven possible combinations of abnormal glucose tolerance, obesity and hypertension (GOH group). Rate of cation imbalance defined as presence of at least one of three cation concentration--red blood cell sodium greater than or equal to 7.0 mEq/l, red blood cell potassium less than 92.5 mEd/l or plasma potassium greater than or equal to 4.5 mEq/l was 88.1% in the GOH, compared to 40.0% in the reference group (p greater than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Comparison of plasma lipids, lipoproteins and dyslipoproteinemia in Israel and the United States. The Lipid Research Clinics Program Prevalence Study.

Based on the common study design, protocol, and laboratory techniques used by the Lipid Research Clinics (LRCs), the study reported here compared the adult study populations examined by the U.S. LRCs and the LRC located in Jerusalem, Israel. A number of 2388 residents of Jerusalem were contrasted with 6528 examinees of the U.S. LRCs regarding their plasma lipid and lipoprotein cholesterol distributions. Marked differences between the U.S. and Jerusalem LRCs were observed in the plasma levels of lipids and lipoprotein cholesterol fractions. Mean total cholesterol concentrations were 2-8% higher in the U.S. compared to the Jerusalem sample. Low density lipoprotein cholesterol levels were higher by approximately 5-15% in the U.S. LRCs, a phenomenon more marked in men than women and in older compared to younger study participants. High density lipoprotein cholesterol values were also higher in the U.S. compared to the Jerusalem LRC, by approximately 10-14% in men and women. These differences were also more pronounced in older compared to younger participants. By contrast, median plasma total triglycerides (and by implication very low density lipoprotein cholesterol) were higher in the Jerusalem compared to the U.S. study participants. This difference ranged from 10-21% by age and sex. The correlations between the plasma lipid/lipoprotein measurements were similar in the two study populations. Only the degree of linear association between plasma total triglyceride and very low density lipoprotein cholesterol was different between the U.S. and Jerusalem, with a correlation coefficient of greater magnitude in the latter. Employing common cutpoints to define dyslipoproteinemia (DLP) observed differences in plasma lipid/lipoprotein distributions determined differences in the frequency of DLP categories between the U.S. and the Jerusalem samples. Higher proportions of Type IV and hypo-HDL were observed in Jerusalem compared to the U.S. By contrast, fewer individuals were classified as Type IIa, Type IIb, and hyper-HDL in Jerusalem relative to the U.S.

Adult↗
PubMed1986

Efficiency of the cervical lead shield during intraoral radiography.

The cervical lead shield was compared with the conventional lead apron with regard to efficiency of protection against radiation during a full-month survey (fourteen periapical and two bitewing radiographs). The study was performed on a Temex tissue-equivalent human phantom, and thermoluminescent dosimetry was used to measure radiation absorption in the ovaries, testes, and thyroid gland areas. Results showed that the cervical shield significantly reduces the amount of radiation to the skin in all three areas and is equally as effective as the combination of lead apron and thyroid shield. It is therefore recommended as a protective measure during intraoral radiography.

Equipment Design↗
PubMed1986

Malignant fibrous histiocytoma complicating mitral valve replacement.

A 67 year old woman developed a fatal febrile illness 8 years after mitral valve replacement for rheumatic valvular heart disease. The final disease persisted for 1 year and was characterized clinically by weakness, weight loss, congestive heart failure and multiple embolic events to the central nervous system and abdominal organs. The source of the emboli was a tumor, malignant fibrous histiocytoma of the left atrium, originating from the anulus fibrosus around the covered base of the prosthetic valve. This unique case suggests the possibility that chronic exposure to materials, such as Dacron, covering prosthetic valves may induce local malignant tumors.

Aged↗
PubMed1986

[Synovial cysts of unusual localization. 2 cases and review of the literature].

Two patients with true synovial cysts in atypical sites (internal compartment of knee and inguinal hollow) were investigated by radioarthrography, ultrasound and computed tomography imaging. The cyst in the hip region originated from a dilated serous bursa of the iliopsoas muscle that did not communicate or was no longer in communication with the joint. In contrast, the cyst of the knee appeared to be a lateral synovial capsule hernia. Positive diagnosis in both cases was dependent on combined ultrasound-CT scan imaging, this eliminating a tumor (sarcoma) of soft tissues. However, affirmation of the synovial origin (mesothelial covering of the wall) of the lesion was obtained by histology only, this allowing differentiation from a "capsular" (fibrous wall) cyst, which probably provokes similar ultrasound and CT scan images.

Aged↗
PubMed1986

The association of dyslipoproteinemia with corneal arcus and xanthelasma. The Lipid Research Clinics Program Prevalence Study.

The prevalence rates of xanthelasma and corneal arcus were computed for normolipidemic and dyslipoproteinemic participants in the Lipid Research Clinics population surveys. The prevalence of both xanthelasma and corneal arcus increased with age, was highest in persons with type II phenotype, and usually low in those with type IV phenotype. The relative effects of age and use of gonadal hormones were different in the two lesions. Both xanthelasma and corneal arcus were associated with increased levels of plasma cholesterol and low-density lipoprotein cholesterol (LDL-C), especially in young males. In general, persons with either lesion had increased odds of having type IIa dyslipoproteinemia but decreased odds of having type IV. Xanthelasma and corneal arcus were highly associated with each other, especially in young people. There was no consistent univariate association of xanthelasma and corneal arcus with smoking, alcohol consumption, blood pressure, obesity, sedentary lifestyle, family history of ischemic heart disease, or glucose and uric acid plasma concentrations. Adjusted odds ratios for ischemic heart disease in participants with xanthelasma and corneal arcus were generally increased, except in older female nonusers of gonadal hormones, in whom they were significantly decreased. Neither xanthelasma nor corneal arcus showed a consistent association with manifestations of peripheral arterial disease. Thus the clinical findings of xanthelasma or corneal arcus, especially in young people, seem to identify persons with plasma lipoprotein abnormalities.

Adult↗
PubMed1986

Dyslipoproteinemias and manifestations of coronary heart disease. The Lipid Research Clinics Program Prevalence Study.

The Lipid Research Clinics Prevalence Study population underwent a noninvasive evaluation to assess the odds of coronary heart disease (CHD) among individuals with various types of dyslipoproteinemia (DLP) relative to the odds for individuals free of DLP in a nonselected population. The noninvasive evaluation included the Rose questionnaire for angina, a resting electrocardiogram, and a graded treadmill exercise test. The presence of manifestations of CHD was assessed by a combination of these findings. Multiple linear regression and multiple logistic regression analyses were used to evaluate associations between CHD and DLP, with adjustments for the following covariates: age, body mass, systolic blood pressure, alcohol consumption, and cigarette use. There were no consistent associations in women or in men 30 to 49 years old. In men 50 to 69 years old, the mean high-density lipoprotein cholesterol (HDL-C) values and HDL-C/cholesterol ratio were significantly lower in the definite CHD and angina categories, compared with the negative (no evidence of CHD) group. Higher odds ratios for CHD were present in those classified as having type IIa, type IV, and hypoHDL DLPs, relative to those classified as normal by the phenotyping algorithm. These associations were consistent across the several categories of CHD manifestations, but did not reach statistical significance after adjustment for multiple testing. A statistically significant lower odds ratio for CHD was observed in men 50 to 69 classified as having hyperHDL when compared with those without DLPs. The associations between CHD and the various forms of DLP were consistent with those observed between CHD and the plasma lipid and lipoprotein-cholesterol concentrations. The Lipid Research Clinics Prevalence Study confirmed the relationship between elevated low-density lipoprotein cholesterol, decreased HDL-C, and noninvasively determined CHD in a free-living asymptomatic population of older men.

Adult↗
PubMed1985

Characterization of plasma lipids and lipoproteins in patients with beta 2-glycoprotein I (apolipoprotein H) deficiency.

The fasting plasma lipids, lipoproteins, and apolipoproteins were evaluated in 5 subjects with undetectable levels of the plasma protein beta 2-glycoprotein I (apolipoprotein H). Family studies confirmed an autosomal co-dominant inheritance pattern for the concentrations of apo H. The total lack of this protein is rare and less than 0.3% of clinic patients demonstrated levels undetectable by radial immunodiffusion. Plasma lipoprotein evaluation in these subjects with beta 2-glycoprotein I absence by analytical ultracentrifugation and compositional analysis demonstrated low concentrations of HDL2b and HDL3. More striking, however, was the lack of a consistent marked effect on the plasma lipoproteins as is found in other apolipoprotein deficiency states. We conclude that the lack of apolipoprotein H does not result in a significant perturbation of normal lipoprotein metabolism as reflected by analysis of fasting plasma lipoproteins. Further study is required to evaluate the role of this glycoprotein in the metabolism of triglyceride-rich lipoproteins.

Adult↗
PubMed1985

Prevalence of chlorpropamide alcohol flush in Jewish Israeli diabetics. The role of serum chlorpropamide concentrations.

Among 53 patients with noninsulin-dependent diabetes (NIDD), chlorpropamide alcohol flushing (CPAF) was more prevalent than among 18 patients with insulin-dependent diabetes (64 vs. 28%, respectively). Among the former, chronic users of chlorpropamide (CP) had a higher prevalence of CPAF than those challenged once with the drug (86 vs. 56%, respectively). Serum CP concentrations were much higher in CP-treated patients, but levels were not different in CPAF-positive compared with CPAF-negative subjects, regardless of the length of their exposure to the drug. Our data confirm the association between CPAF and NIDD in a Jewish Israeli diabetic population and the effect of serum CP levels on the prevalence of this phenomenon.

Adult↗
PubMed1984

Exercise-induced left ventricular dysfunction in young men with asymptomatic diabetes mellitus (diabetic cardiomyopathy).

Radionuclide ventriculographic studies were performed at rest and during exercise on 30 consecutive men, aged 21 to 35 years with diabetes mellitus without evidence of coronary artery or any other cardiovascular disease, and in 20 normal age-matched subjects. Sixteen (53%) were treated with insulin and 14 (47%) were treated with either diet (6 patients) or oral antidiabetic therapy (8 patients). All patients from both groups had normal left ventricular (LV) ejection fraction (EF) at rest. In 5 of the 30 diabetic patients (17%), LVEF decreased after exercise, in 8 (27%) it remained unchanged and in 17 it increased normally. Mean LVEF at rest and after exercise in this group was 66 +/- 7% and 72 +/- 7% (+/- standard deviation), respectively. In all normal subjects, LVEF increased after exercise. Mean LVEF at rest and after exercise in the normal group was 66 +/- 7% and 76 +/- 9%, respectively. No patient had evidence of regional dysfunction at rest or after exercise. LV function was not related to serum glucose levels during the test, modality of treatment, insulin dependency or duration of the disease. Three of 4 patients with diabetic microvascular complications showed LV dysfunction. In 4 of 5 patients in whom LVEF decreased after exercise, thallium studies showed normal perfusion. Thus, diabetes mellitus may cause exercise-induced global LV dysfunction in young men with no evidence of cardiovascular disease. This phenomenon apparently does not seem to follow the known course of diabetic microvascular complications.

Adolescent↗