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S Lee

Publications and source records attributed to S Lee.

At least 1,045 records · Page 58Linked to original sources
PubMed1994

Decreased regional cortical gray matter volume in schizophrenia.

OBJECTIVE: The authors hypothesized that cortical gray matter volume reduction in schizophrenia is greatest in the heteromodal association cortex. This area comprises a highly integrated, reciprocally interconnected system that coordinates higher order cortical functions. METHOD: Total brain and regional gray matter volumes were calculated in 46 schizophrenic patients and 60 age and sex-matched comparison subjects by using magnetic resonance images. Disease specificity was examined by assessing 27 patients with bipolar disorder. Approximations to the dorsolateral prefrontal cortex, inferior parietal lobule, and superior temporal gyrus were selected as regions of interest for the heteromodal association cortex. Occipital and sensorimotor areas were used as comparison regions to test the hypothesis for regional specificity. RESULTS: Gray matter volume was reduced in schizophrenic patients in index regions even after covariance for overall brain volume, sex, and age. Bipolar disorder patients did not exhibit heteromodal gray matter reduction. Comparison regions did not differ among the three groups. Global gray matter volume was not different among groups after covariance for global brain volume. Comprehensive individual region post hoc analysis found no additional gray matter differences. CONCLUSIONS: These findings support the theory of disproportionate reduction of gray matter volume in the heteromodal association cortex specific to schizophrenia.

Adult↗
PubMed1994

1,25-Dihydroxyvitamin D3 and pancreatic beta-cell function: vitamin D receptors, gene expression, and insulin secretion.

Previous studies have indicated that the pancreas has receptors specific for 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and that 1,25-(OH)2D3 increases insulin secretion in vitamin D-deficient rats. In this study we report that in vitamin D-replete, but calcium-deficient, rats in which 1,25-(OH)2D3 levels are elevated, insulin secretion is not altered. In addition, in in vitro studies 1,25-(OH)2D3 at concentrations of 10(-10)-10(-7) M was consistently found to inhibit insulin secretion from islets of vitamin D-replete rats or from the rat insulinoma beta-cell line RIN 1046-38. The RIN cell line was found to contain both vitamin D receptors and calbindin-D28k (CaBP-D28k) protein and mRNA. In RIN cells, treatment with sodium butyrate (2 mM for 3 days) induces a more islet phenotype, as indicated by increased insulin content and secretion and increased insulin gene expression. 1,25-(OH)2D3 treatment (50-100 nM for 48 or 72 h) had no effect on the enhanced levels of insulin secreted in the presence of butyrate. However, 2 mM sodium butyrate induced CaBP-D28k protein (4-fold; control, 0.8 +/- 0.2; sodium butyrate, 3.5 +/- 0.1 microgram/mg protein) and mRNA (3-fold) in the RIN cell line, in accord with the induction by butyrate of insulin content and secretion and beta-cell differentiation, suggesting a possible role for CaBP-D28k in these processes. Although 1,25-(OH)2D3, unlike butyrate, did not enhance insulin secretion, both 1,25-(OH)2D3 (100 nM) and butyrate (2 mM) inhibited RIN cell growth (to 69% and 28% of the control, respectively), and butyrate and 1,25-(OH)2D3 in combination led to a further inhibition of cell growth (to 13% of the control). In response to 1,25-(OH)2D3 (10 nM for 72 h), vitamin D receptors were up-regulated 313% in RIN cells [control, 37 +/- 2; 1,25-(OH)2D3 treated, 115 +/- 5 fmol/mg protein]. In conclusion, 1) contrary to previous studies in the vitamin D-deficient rat, our findings indicate that 1,25-(OH)2D3 action does not necessarily result in enhanced insulin secretion; 2) inhibition of cell growth and up-regulation of vitamin D receptors by 1,25-(OH)2D3 suggest that parameters in addition to insulin secretion can be affected by 1,25-(OH)2D3 in the beta-cell; 3) the RIN beta-cell line provides a novel in vitro system for studying the effect of the vitamin D endocrine system on pancreatic islet physiology.

Aging↗
PubMed1994

Long-term efficacy of acute thrombolytic therapy for myocardial infarction.

We conducted a retrospective study (1981-1990) to determine whether the efficacy of intracoronary thrombolysis (ICT) could be evaluated from data obtained solely after recanalization. We investigated 55 successful ICT patients (38 with anterior and 17 with inferior myocardial infarction (MI)), and 31 control infarct patients without recanalization. The total serum creatine phosphokinase release (sigma CPK), the extent of infarction measured by T1-201 single photon emission computed tomography (total DS) and the disturbance of regional wall motion (asyn.%) were investigated as parameters for distinguishing the successful ICT and control groups. Discriminatory ability for the two groups was highest with the total DS in all patients. Only the total DS differed significantly between the two groups in patients with inferior infarction. Misidentification of control patients as successful patients was least frequent (25.5%) when using the total DS. These findings suggest that the effectiveness of ICT for acute MI may be assessed on the basis of data obtained solely after recanalization, with the total DS being particularly useful.

Adult↗
PubMed1994

Naked megakaryocyte nuclei in bone marrows of patients with acquired immunodeficiency syndrome: a somewhat specific finding.

Naked megakaryocyte nuclei (NMN) were studied retrospectively in 100 bone marrow biopsy sections and aspirates from patients with acquired immunodeficiency syndrome (AIDS) and 124 non-AIDS controls. An NMN score was developed to semiquantitate the NMN. The AIDS bone marrows had an incidence of 97% and a mean NMN score of 2.24 which was a higher incidence and score than the control groups and was statistically significant. The control groups consisted of 20 chronic myeloproliferative disorders (incidence of 70% and score of 1.4); 24 cases of acute myelogenous leukemia and myelodysplastic syndrome (incidence of 29.2% and 0.46 score); 22 cases of non-AIDS immune thrombocytopenic purpura (incidence of 50% and 0.82 score); 11 cases of acute lymphocytic leukemia (0% incidence); 21 cases of anemia (52.4% incidence and 0.7 score); and 26 cases of lymphoma staging (35% incidence and 0.35 score). It is concluded that NMN are a very frequent and, with a high score, a specific finding in AIDS bone marrow examinations.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Cardiovascular and metabolic changes in spontaneously hypertensive rats following streptozotocin administration.

OBJECTIVES: To investigate whether the high mortality rate that occurs in streptozotocin (STZ)-diabetic spontaneously hypertensive rats (SHR) is related to abnormalities in glycemic control, in hemodynamics and cardiac function, or in susceptibility to the occurrence of ventricular arrhythmias. METHODS: Diabetes was induced in SHR and Wistar-Kyoto (WKY) rats by the intravenous injection of STZ 55 mg/kg. Intraperitoneal glucose tolerance tests were performed after six and 11 weeks. Blood pressure was measured in conscious rats at weeks 0 and 11 with a tail-cuff method and in anesthetized animals at week 12 through a cannulated artery. Response of myocardial function to rapid intravenous infusion of saline 10 mL/kg/min and the times of onset of ventricular arrhythmias during intravenous infusion of aconitine 20 micrograms/kg/min were determined in anesthetized rats at week 12. Plasma samples from the rats were assayed for glucose, insulin, triglycerides and carnitine. RESULTS: STZ injection caused hyperglycemia, hypoinsulinemia and glucose intolerance equally in SHR and WKY. Diabetic SHR exhibited significant hypertriglyceridemia, depletion in plasma carnitine, impaired responses of blood pressure and myocardial function to rapid intravenous infusion of saline and a 37.5% mortality rate, whereas diabetic WKY did not exhibit these changes. SHR and WKY, diabetic or nondiabetic, were equally sensitive to the induction of ventricular arrhythmias by aconitine infusion. CONCLUSION: Mortality of the STZ-diabetic SHR is not due to an exaggeration of the impaired glycemic control, but may be attributed to the occurrence of cardiac dysfunction. The development of life-threatening cardiac arrhythmias, while unlikely, cannot be completely excluded.

Aconitine↗
PubMed1994

Primary malignant mesothelioma of the pericardium. Case report and literature review.

Pericardial mesothelioma is a highly lethal and fortunately rare cardiac neoplasm. We present the clinical and pathologic features of a primary sarcomatoid mesothelioma. To better understand the clinical, radiographic, and pathologic features of this entity, we reviewed 27 cases described in the English literature from 1972 through 1992, which, together with our case, provided a total of 28 cases. Findings of the review include a male-female ratio of 2:1, a wide age range (12 to 77 years; mean, 47 years), and documented asbestos exposure in 4 of 28 (14%) patients. Commonly used imaging studies do not appear to offer great sensitivity, for a mass was detected by echocardiography in only 2 of 16 (12%) patients and by computed tomography in 4 of 9 (44%). Pathologic findings revealed a diffuse growth pattern in most cases (18 of 25, or 72%), together with an equal distribution between the biphasic, epithelioid, and sarcomatoid variants. Effusion cytology revealed malignant cells in only 2 of 10 (20%) cases. With or without therapy, prognosis was uniformly poor, since 24 of 27 patients were dead of the disease at the time the reports were published.

Adult↗
PubMed1994

An enhanced surveillance program for adult T-cell leukemia in central Brooklyn.

The Brooklyn Adult T-cell Leukemia/Lymphoma (ATL) study was developed to estimate the incidence of the human T-cell lymphotropic virus type I (HTLV-I)-associated ATL in the Crown Heights/Bedford Stuyvesant community. This central Brooklyn black community is an area which has already been shown in earlier reports to be endemic for HTLV-I-associated ATL. Surveillance has been conducted at seven area hospitals that serve this community, with surveillance already completed at five hospitals. Potential study subjects who are 20 years or older are identified by the review of admission records, discharge summaries, pathology and clinical chemistry reports, or physician referrals. Diagnoses of leukemia or lymphoma, or the presence of leukocytosis or hypercalcemia are used as criteria to identify the subjects. Participating subjects give a sample of blood for the determination of HTLV-I infection by serologic tests. At the time of enrollment, subjects provide demographic information including age, sex and birthplace. After one year of surveillance at five hospitals (39.5% of inpatient beds in the catchment), we have identified 12 cases of HTLV-I-associated ATL. The mean age of the ATL patients was 50 years, with patients being predominantly female (83.3%) and often Caribbean immigrants (83.3%). Interestingly, 42% of our cases were identified solely by findings of hypercalcemia from clinical chemistry reports. The remaining ATL cases were identified by physician referral. This enhanced surveillance program that uses both clinical and laboratory criteria for ATL case ascertainment can serve as a prototype for similar surveillance in other areas endemic for HTLV-I-associated ATL--an important effort because of the strong potential for disease prevention.

Adult↗
PubMed1994

MR volume segmentation of gray matter and white matter using manual thresholding: dependence on image brightness.

PURPOSE: To describe a quantitative MR imaging segmentation method for determination of the volume of cerebrospinal fluid, gray matter, and white matter in living human brain, and to determine the method's reliability. METHODS: We developed a computer method that allows rapid, user-friendly determination of cerebrospinal fluid, gray matter, and white matter volumes in a reliable manner, both globally and regionally. This method was applied to a large control population (N = 57). RESULTS: Initially, image brightness had a strong correlation with the gray-white ratio (r = .78). Bright images tended to overestimate, dim images to underestimate gray matter volumes. This artifact was corrected for by offsetting each image to an approximately equal brightness. After brightness correction, gray-white ratio was correlated with age (r = -.35). The age-dependent gray-white ratio was similar to that for the same age range in a prior neuropathology report. Interrater reliability was high (.93 intraclass correlation coefficient). CONCLUSIONS: The method described here for gray matter, white matter, and cerebrospinal fluid volume calculation is reliable and valid. A correction method for an artifact related to image brightness was developed.

Adult↗
PubMed1994

Psychosocial factors influencing smokeless tobacco use by teen-age military dependents.

Using bivariate and logistic regression analysis, we explored psychosocial correlates of smokeless tobacco (SLT) use in a sample of 2,257 teenage military dependents. We built separate regression models for males and females to explain triers and users of SLT. Results show female and male triers share five factors regarding SLT use--parental and peer approval, trying smoking, relatives using SLT, and athletic team membership. Male trial of SLT was additionally associated with race, difficulty in purchasing SLT, relatives who smoke, current smoking, and belief that SLT can cause mouth cancer. Male use of SLT was associated with race, seeing a dentist regularly, SLT counseling by a dentist, parental approval, trying and current smoking, and grade level. In all models, trying smoking was the strongest explanatory variable. Relatives and peers exert considerable influence on SLT use. Few triers or users had received SLT counseling from their dentist despite high dental utilization rates.

Achievement↗
PubMed1994

Hepatocarcinogenesis is the sequel to hepatitis in Z#2 alpha 1-antitrypsin transgenic mice: histopathological and DNA ploidy studies.

Z mutant-associated alpha 1-antitrypsin deficiency in human beings leads to hepatitis and, in some cases, hepatocellular carcinoma. To begin to delineate the molecular basis for the development of hepatocellular carcinoma in alpha 1-antitrypsin deficiency, we previously developed transgenic mice using human alpha 1-antitrypsin M and Z genomic clones. High-copy Z lineage mice (12 gene copies/haploid mouse genome; "Z#2") had hepatocytes distended with human alpha 1-antitrypsin deficiency globules. Hepatitis was present, and the morphological changes mimicked those observed in human alpha 1-antitrypsin deficiency-related liver disease. The numbers of hepatocytes containing alpha 1-antitrypsin globules decreased with age, and alpha 1-antitrypsin-negative nodular aggregates of hepatocytes increased in number and size. Hepatocytic dysplasia occurred as early as 6 wk and was almost universally present at 1 yr. Nodules of dysplastic cells demonstrating aneuploidy were seen as early as 10 wks. These became persistent, proliferative lesions. Dysplasia and aneuploidy distinctly increased with time and advancing microscopic stage as lesions progressed to malignancy. Tumors were seen after 1 yr as adenomas, which are aneuploid and most likely well-differentiated hepatocellular carcinoma, and borderline malignant lesions; and, in 82% of Z#2 mice 16 to 20 mo old, as invasive hepatocellular carcinoma. These observations suggest but do not conclusively prove that hepatocellular carcinoma in alpha 1-antitrypsin deficiency and other hepatic disorders arises as a result of a common, endogenously stimulated pathway for hepatocellular carcinogenesis.

Adenoma↗
PubMed1993

TSG-6: a TNF-, IL-1-, and LPS-inducible secreted glycoprotein associated with arthritis.

TSG-6 (TNF-stimulated gene 6) was originally discovered by differential screening of a cDNA library prepared from TNF-stimulated human diploid FS-4 fibroblasts. We show that the 35-kDa protein encoded by TSG-6 was undetectable in the medium of untreated FS-4 cultures, whereas its production reached approximately 1400 and 700 ng/10(6) cells after 24-h treatment with IL-1 or TNF, respectively. Stimulation of TSG-6 protein and mRNA levels was also demonstrated in normal human mononuclear cells by treatment with TNF and, especially, by LPS. In view of the inducibility of TSG-6 by inflammatory cytokines and its earlier demonstrated affinity for hyaluronan, we examined the presence of TSG-6 protein in the synovial fluids from patients with various forms of arthritis. TSG-6 protein was undetectable in the joint fluids of persons with no known history of arthritis, but high levels of TSG-6 oere demonstrated in the synovial fluids of a majority of arthritis patients. TSG-6 protein was also detected in the sera of some of the arthritis patients, albeit at concentrations that were less than in the joint fluids. To investigate the source of TSG-6 in the synovial fluids, we examined the production of TSG-6 protein in cultures of synovial cells. Synoviocytes from rheumatoid arthritis patients produced TSG-6 protein constitutively, and this production was increased by treatment with TNF or IL-1, but not with TGF-beta. Steady-state levels of TSG-6 mRNA were also increased in synoviocytes after treatment with TNF or IL-1. The presence of high levels of TSG-6 protein in the synovial fluids of arthritis patients and its inducibility by inflammatory cytokines in fibroblasts, mononuclear cells, synoviocytes, and chondrocytes suggest a role for TSG-6 in arthritis and inflammation.

Adolescent↗