Biomedical subjects

J Hart

Publications and source records attributed to J Hart.

At least 145 records · Page 8Linked to original sources

PubMed1995

Contractile effects of diaspirin cross-linked hemoglobin (DCLHb) on isolated porcine blood vessels.

The effects of diaspirin cross-linked hemoglobin (DCLHb) on vascular tone were examined in arterial and venous rings isolated from mesenteric, renal, femoral, and pulmonary blood vessels. Rings were placed in organ baths at optimal passive tension in Krebs' solution (37 degrees C) and aerated with a mixture of 95% O2/5% CO2. Vessels were treated with increasing concentrations of DCLHb or an iso-osmotic serum albumin solution. All artery and vein rings contracted in the presence of DCLHb. With the exception of the pulmonary vein, the magnitude of the tension increase with DCLHb was greater in the arteries than in the veins. Removal of the endothelium by scraping or the addition of a nitric oxide synthase inhibitor blocked the DCLHb-induced contraction in the pulmonary artery and vein. DCLHb also significantly reduced basal cyclic guanosine-3-5'-monophosphate in the pulmonary vein. These studies suggest that the constrictor activity of DCLHb is due primarily to inhibition of basal nitric oxide-induced relaxation of the vascular smooth muscle.

Acetylcholine↗

PubMed1995

Prognostic value of bcl-2 oncoprotein expression in stage II colon carcinoma.

The bcl-2 proto-oncogene encodes a Mr 25,000 protein that has been shown to prevent apoptosis or programmed cell death. The bcl-2 protein is detectable in basal cells of normal colonic epithelium, and an altered topographic distribution of this protein is found in colonic neoplasms. However, the clinical significance of abnormal bcl-2 expression in colon carcinomas remains unknown. We examined the prognostic value of the bcl-2 protein in TNM stage II colon carcinomas and its relationship to DNA ploidy, cell proliferation indices, p53 expression, and clinicopathological features. We analyzed 119 resected and otherwise untreated, paraffin-embedded stage II colon carcinomas for bcl-2 and p53 protein expression using immunohistochemistry. DNA ploidy and proliferative index (% S-phase + % G2-M) were determined by flow cytometry, and tumor grade and vascular microinvasion were assessed on histological sections. Cytoplasmic expression of the bcl-2 protein was detected in 72 (66%) of 110 carcinomas, and a high level of expression was significantly correlated with diploid DNA content (P = 0.02) and low proliferative activity (P = 0.005). bcl-2 was not associated with nuclear p53 expression. In a univariate analysis, a higher fraction of bcl-2-positive tumor cells was associated with better relapse-free survival (P = 0.02) and overall survival (P = 0.05) rates. Moreover, a high level of bcl-2 expression was an independent predictor of better relapse-free survival (P = 0.04), but not overall survival (P = 0.14), after adjustment for other variables, including proliferative index, DNA ploidy, and race. In conclusion, bcl-2 overexpression is associated with favorable prognostic features and may predict clinical outcome in stage II colon carcinomas.

Adult↗

PubMed1994

Relationship of P-glycoprotein and carcinoembryonic antigen expression in human colon carcinoma to local invasion, DNA ploidy, and disease relapse.

BACKGROUND: The clinical significance of expression of the MDR1 gene product P-glycoprotein (P-gp) in relation to the intrinsic drug resistance and progression of human colon cancer is largely unknown. To elucidate the role of P-gp in these cancers further, the frequency and intensity of P-gp and carcinoembryonic antigen (CEA) immunostaining were measured at the single-cell level and correlated with known prognostic indices (i.e., DNA ploidy, vessel/lymphatic microinvasion, histologic grade, and disease relapse). METHODS: Fifty-two untreated Dukes' Stage B2 colon cancers were immunostained with the anti-P-gp monoclonal antibodies JSB-1 and HYB-241, and anti-CEA. DNA content and cell proliferation were measured by flow cytometry. RESULTS: JSB-1 and HYB-241 detected P-gp in 44 and 42 of 52 carcinomas, respectively, and CEA was found in 50 of the 52 tumors. The level of P-gp expression was not associated with DNA ploidy, indices of local invasiveness, or histologic grade. In a multivariate analysis, however, a high level of P-gp expression (as assessed by JSB-1), DNA aneuploidy, microinvasion, and single carcinoma cell invasion individually predicted disease relapse (P < 0.05). CONCLUSIONS: The results indicate that diffuse P-gp immunostaining is present in the majority of Stage B2 human colon cancers and therefore may be an important contributor to their intrinsic drug resistance. The association between a high level of P-gp expression and disease relapse suggests that P-gp can be of prognostic value in Stage B2 colon cancers.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1994

The only way is up.

Explore the source record for details and available documents.

Employee Performance Appraisal↗

PubMed1994

Hepatitis C virus-associated glomerulonephritis. Effect of alpha-interferon therapy.

Hepatitis C virus (HCV) infection may present as a primary glomerular disease. We report 34 adult patients who presented with proteinuria and had circulating anti-HCV antibodies. Primary risk factors included a history of intravenous drug abuse (56%) or blood transfusion (18%). Patients presented with nephrotic syndrome (71%) or with non-nephrotic proteinuria (29%) and had membranoproliferative or acute proliferative glomerulonephritis on renal biopsy. Signs of clinical liver disease were infrequent (18%), though elevated liver function tests were common (66%) and liver biopsy in 16 of 18 patients showed chronic active hepatitis. Cryoglobulinemia was frequent (59%), but only 44% had extrarenal manifestations. In 100% of cases tested, HCV RNA could be found in the serum or cryoprecipitates. Fourteen patients received interferon alpha for 6 to 12 months with a significant reduction in proteinuria but no improvement in renal function. A good clinical response correlated with disappearance of HCV RNA from the serum during treatment; however, relapse of viremia and renal disease was common after completing therapy. Evidence for HCV infection should be sought in all patients with primary glomerular disease. The optimal treatment strategy, however, remains to be defined.

Adult↗

PubMed1994

Assessment of hepatitis C virus RNA levels by quantitative competitive RNA polymerase chain reaction: high-titer viremia correlates with advanced stage of disease.

A quantitative competitive RNA polymerase chain reaction (QC-PCR) assay was developed for measuring absolute levels of hepatitis C virus (HCV) RNA in the sera of 121 viremic persons, including 64 asymptomatic blood donors, 39 symptomatic patients referred for treatment of chronic hepatitis C, and 18 patients with end-stage liver disease referred for liver transplantation. Mean HCV RNA levels (log molecules per milliliter) were lowest among blood donors with normal alanine aminotransferase (ALT) values (5.8 +/- 1.5), higher among blood donors with elevated ALT (6.9 +/- 0.8) and clinic patients with chronic active hepatitis (6.9 +/- 0.7), and highest among patients with cirrhosis (7.1 +/- 0.8) or end-stage liver disease (7.6 +/- 1.0). High-titer viremia ( > or = 7.5 logs/mL) was more frequent among patients with end-stage liver disease (14/18; 78%) than either blood donors (10/64; P < .001) or patients with chronic active hepatitis (7/26; P < .001). Thus, 121 (94.5%) of 128 anti-HCV-positive persons were viremic. QC-PCR may be valuable for monitoring HCV infection status and selecting individuals for therapy.

Base Sequence↗

PubMed1994

A report using a hybrid ICD system: the need for compatibility among implanted defibrillator components.

The successful implantation of an ICD system with hardware from three different manufacturers is described. This case exemplifies the need for compatibility of components among different manufacturers. This is most relevant at a time when rapidly changing technology and hardware availability may require a mixing, by informed practitioners, of ICD system components. The parallel to the development of the uniform IS-1 standard for bradycardia devices is made.

Defibrillators, Implantable↗

PubMed1994

IN vitro cell-mediated immune reactions in herpes zoster patients treated with cimetidine.

In a double-blind placebo-control study the immunomodulating effect of cimetidine treatment for one week and placebo was investigated for cell-mediated immune reactions of 22 patients with herpes zoster (HZ). The mitogen induced leukocyte migration inhibition test (LMIT) and the in vitro proliferation of the patients' lymphocytes to exogenous IL-2 were used. Before any treatment, the mitogen induced leukocyte migration inhibition capacity (LMIC) of HZ patients was found to be significantly reduced (p < 0.02) as compared to healthy blood bank donors (controls). After one week, within the same treatment, the LMIC was significantly improved (p < 0.01). The patients' lymphoproliferative response to IL-2, before any treatment, was not significantly different from that of controls (p < 0.05). However, significantly higher values (p < 0.001) were found in patients tested 7 days after the disease onset as compared to those tested after 12 days. One-week cimetidine treatment significantly improved (p < 0.05) the lymphoproliferative response to IL-2 of initially low responders and had no effect on higher responder patients. In contrast to this, after one week of placebo treatment, a significant decrease in the patients' lymphoproliferative response to IL-2 could be observed as compared to patients' initial responses (p < 0.05) or to those of controls (p < 0.05). Although the number of cases is very small. The data suggest that after cimetidine treatment, as compared to placebo, healing from skin rash and pain was achieved in a significantly shorter time (p < 0.01).

Adult↗

PubMed1994

Analysis of clinicopathologic prognostic features in patients with gastric adenocarcinoma.

BACKGROUND: We evaluated the influence of several clinicopathologic variables on 5-year actuarial survival rate after curative resection of gastric adenocarcinoma. METHODS: Clinical characteristics were retrieved from the records of all patients who underwent gastric resection for curative intent between 1965 and 1986 at The University of Chicago Medical Center, and follow-up was obtained from our tumor registry. Pathologic characteristics were determined from a detailed review of all available histopathologic slides. RESULTS: One hundred seventy-eight patients underwent a curative resection during the study period at our institution. Overall 5-year actuarial survival rate was 29%. The relationship between clinicopathologic variables and 5-year survival rate was evaluated by Kaplan-Meier survival curve construction and chi-squared analysis. Lymphatic and/or capillary microinvasion (absent vs present, p < 0.001), tumor location (antrum and body vs gastroesophageal junction, p = 0.05), local extent of disease (limited to the gastric wall versus involving adjacent organs, p = 0.003), stage (absence versus presence of lymph node metastases, p < 0.001), Lauren type (intestinal versus diffuse, p < 0.01), and Ming type (expanding versus infiltrative, p < 0.02) significantly influenced survival. When a multivariate analysis with logistic regression of 5-year survival was performed, lymphatic and/or capillary microinvasion emerged as the only statistically significant, independent prognostic factor associated with long-term survival (p = 0.039). If microinvasion was omitted from the analysis, lymph node metastases (p < 0.05) and the extension to adjacent organs (p < 0.04) became the only statistically significant variables. Multiple correlation analyses suggested that microinvasion is an early histopathologic finding that correlates with a more aggressive natural history. CONCLUSIONS: Lymphatic and/or capillary microinvasion is a more powerful predictor of 5-year survival than lymph node metastases or tumor extension to adjacent organs. Correlation among clinicopathologic variables suggests that microinvasion may represent an early finding, serving as a potential marker for a biologically more aggressive tumor.

Adenocarcinoma↗

PubMed1994

Consultants' complaints about the quality of referrals from primary care physicians: tempest in a teapot?

OBJECTIVE: To determine whether consultants' general impressions of the quality of referrals from family physicians are consistent with their evaluations of the quality of specific referrals. METHODS: Data were gathered using two questionnaires, completed separately by the same group of consultants working in a Health Maintenance Organization (HMO). Both questionnaires contained the same items and were designed to cover the following topics: (a) the general impression of the consultants about the quality of referrals received from family physicians; (b) their specific evaluation of all consecutive patient referrals by family physicians over a one-week period. Forty consultants employed in an outpatient regional multidisciplinary clinic of the largest HMO in Israel participated in the study. Of the 3136 referrals received over a one-week period, 1466 fulfilled the inclusion criteria, and 1416 were evaluated (response rate, 97%). RESULTS: Most of the estimates of the number of unnecessary/inappropriate referrals obtained in the general impression questionnaire were 2 to 5 times higher (p < or = 0.001) than those obtained in the consultants' evaluation questionnaire about specific referrals. CONCLUSIONS: This study suggests that consultants' complaints of unjustified and inappropriate referrals from family physicians must be taken with great reservation, at least within the framework of health systems that do not encourage physicians to produce a large number of services.

Family Practice↗

PubMed1994

Liver allograft pathology.

Complications following orthotopic liver transplantation are often difficult to differentiate from each other. Based on their experience with more than 1,800 transplantations, the authors strive to describe the varied histologic appearances of allograft injuries and how they differ.

Graft Rejection↗

PubMed1993

Divergent age-associated patterns of high density lipoprotein cholesterol and its percentage in Jewish and Moslem Arab Israeli children and adolescents: the Petach Tikva Project.

We studied three groups of Israeli Jewish schoolchildren in and surrounding Petach Tikva, Israel, cross-sectionally, at ages 9-10, 13-14, and 16-18 years, and compared lipid and lipoprotein levels and age-associated lipoprotein patterns in the same age groups of boys and girls in neighboring Israeli Moslem Arab schools during 1986-1987. Moslem children displayed striking differences in the levels of lipids and age-associated patterns of lipoproteins compared with Jewish schoolchildren. The mean total cholesterol levels were lower in the Moslem children, in both sexes, in every age grouping. High density lipoprotein cholesterol (HDL-C) levels were significantly higher at age 16-18 in the Moslem boys than in the Jewish boys. While the Jewish boys displayed a previously reported "typical" pattern of lower HDL-C levels postpuberty compared with prepuberty, the Moslem boys had markedly higher mean HDL-C levels at age 16-18 compared with those at age 9-10. The Moslem girls also had higher HDL-C levels at age 16-18 than those observed in the age 9-10 group. Concomitantly higher HDL-C levels (HDL-C/total cholesterol (%)) were seen in the Moslem boys and girls, at age 16-18 compared with age 9-10, but were not observed in the Jewish children. The identification of an ethnic group in whom HDL-C appears to increase at or near puberty could provide opportunities to elucidate factors that may increase HDL-C in individuals or in populations.

Adolescent↗

PubMed1993

Membranoproliferative glomerulonephritis associated with hepatitis C virus infection.

BACKGROUND AND METHODS: Hepatitis C virus (HCV) infection causes both acute and chronic liver disease and is also associated with mixed cryoglobulinemia. Whether HCV is also associated with renal disease, as is the hepatitis B virus, is not known. We describe the clinical, pathologic, virologic, and immunologic features of eight patients with HCV infection who were referred to nephrologists for glomerulonephritis. Four patients were treated with interferon alfa. RESULTS: All eight patients had proteinuria, and seven had decreased renal function. Renal biopsy in all patients revealed membranoproliferative glomerulonephritis, characterized by the deposition of IgG, IgM, and C3 in glomeruli. Electron microscopy of the biopsy specimens showed cryoglobulin-like structures in three of four patients. All eight patients had HCV RNA detected in their serum, elevated serum aminotransferase concentrations, and hypocomplementemia, and the majority had cryoglobulins and circulating immune complexes in their serum. Cryoprecipitates from the three patients who were tested contained HCV RNA and IgG anti-HCV antibodies to the nucleocapsid core antigen (HCVc or c22-3). IgM rheumatoid factors, present in all patients, bound anti-HCV IgG in all six patients tested. Four patients received interferon alfa for 2 to 12 months; all had evidence of decreased HCV replication and improvement of their renal and liver disease. CONCLUSIONS: Chronic HCV infection is associated with cryoglobulinemia and membranoproliferative glomerulonephritis. The pathogenesis is unknown, but may relate to deposition within glomeruli of immune complexes containing HCV, anti-HCV IgG, and IgM rheumatoid factors.

Adult↗

PubMed1993

Anatomic correlates of memory from intracarotid amobarbital injections with technetium Tc 99m hexamethylpropyleneamine oxime SPECT.

OBJECTIVE: To better identify regions of the brain affected by intracarotid amobarbital injections and to more precisely predict whether resections of specific brain regions will cause postoperative memory deficits. DESIGN: We modified the standard intracarotid amobarbital procedure by adding a radioactive tracer to the amobarbital injection, thereby providing better correlation between behavior and deactivated brain region. SETTING: Tertiary-care hospital center with a dedicated program for medical and surgical treatment of epilepsy. PATIENTS: We studied 39 patients with medically intractable epilepsy drawn from a regional referral base. INTERVENTION: Intracarotid injection of 125 mg of sodium amobarbital with 37 MBq of technetium Tc 99m hexamethylpropyleneamine oxime (HMPAO), followed by language and memory testing. MAIN OUTCOME MEASURES: The distribution of amobarbital as measured by single photon emission computed tomographic imaging of HMPAO and patient performance on memory tasks. RESULTS: Medial temporal regions were irrigated by the amobarbital in only 28% of the injections. Overall, findings suggest that medial temporal and lateral neotemporal cortex play a role in memory. CONCLUSIONS: The regions involved in memory function vary by individual, as does the distribution of amobarbital. Thus, the most accurate method of determining correlation of brain region with memory function during intracarotid amobarbital injection involves the use of a tracer such as HMPAO.

Adolescent↗

PubMed1993

Effect of long-term colchicine therapy on jejunal mucosa.

Colchicine is recommended as daily prophylactic therapy in patients with familial Mediterranean fever (FMF) to prevent febrile paroxysms. The drug is known to be a potent inhibitor of mitotic activity and might therefore be expected to have a significant adverse effect on tissues that undergo rapid turnover. We studied small bowel biopsies from nine patients with FMF who were receiving daily low-dose oral colchicine therapy. In each patient the lengths of 20 crypts and villi were measured and the number of mitotic figures in 20 crypts were counted. The data were compared with similar measurements from histologically normal-appearing biopsies obtained from 14 patients with a variety of mild gastrointestinal complaints. The mean crypt length was found to be significantly greater (0.197 mm vs 0.186 mm, P < 0.0001) and the mean villous length significantly smaller (0.369 mm vs. 0.442 mm, P < 0.0001) in the FMF patients than in the control population. In addition, the mean number of mitotic figures per crypt was significantly higher in the FMF patients (2.58 vs 1.00, P < 0.001). The data reveal a pattern of mucosal injury in the colchicine-treated FMF patients characterized by a hyperplastic crypt-villous atrophy pattern with increased mitotic rate, which is indicative of an increase in cell turnover and opposite to what we anticipated based on colchicine's known effect on mitotic activity.

Adult↗

PubMed1993

Distortion in the parental transmission of HLA-A2 haplotypes (locus A,B).

The parental transmission of HLA-2 antigen in association with the epitopes BW4 and BW6 (class I HLA haplotypes locus A,B) was analyzed in sons and daughters from 42 families in which one of the parents carried the HLA-A2 antigen. When the parental transmission of A2 BW4 and A2 BW6 was compared, it was observed that a significantly higher number of siblings inherited the haplotype A2 BW4 from the paternal than from the maternal haplotype. Although the number of cases is small, the mode of inheritance of haplotype A2 BW6 was completely different. The genetic distortion in the transmission of HLA-2 BW4 and HLA-2 BW6 was observed in children of both sexes.

Cytotoxicity, Immunologic↗

PubMed1993

Mirth, laughter and gelastic seizures.

Little is known about what pathways subserve mirth and its expression laughter. We present three patients with gelastic seizures and laughter elicited by electrical stimulation of the cortex who provide some insight into the mechanisms of laughter and its emotional concomitants. The first patient had seizures manifested by laughter without a subjective feeling of mirth. Magnetic resonance imaging showed a cavernous haemangioma in the left superior mesial frontal region. Ictal subdural electrode recording showed the seizure onset to be in the left anterior cingulate gyrus. Removal of the lesion and of the seizure focus rendered the patient virtually seizure free over 16 months of follow-up. The other two patients had complex partial seizures of temporal lobe origin. Electrical stimulation of the fusiform gyrus and parahippocampal gyrus produced bursts of laughter accompanied by a feeling of mirth. These cases reveal a high likelihood of cingulate and basal temporal cortex contribution to laughter and mirth in humans, and suggest the possibility that the anterior cingulate region is involved in the motor act of laughter, while the basal temporal cortex is involved in processing of laughter's emotional content in man.

Adult↗

PubMed1993

Mode of inheritance of HLA haplotypes locus A,B in siblings of different sexes.

METHOD: Forty-eight parents and 172 children were typed for class I HLA antigens, locus A,B. RESULTS: Although the number of cases is small, we observed: (1) a significantly decreased number of sons born after a first delivery of a son, as compared to a first delivery of a daughter; (2) significantly increased sharing of maternal class I HLA antigens between the firstborn son and his brothers from higher birth orders, as compared to his sisters; and (3) HLA-A2 antigen, which is known to be involved in HLA restricted cytotoxic reactions in the recognition of minor histocompatibility antigens, was inherited in subsequent deliveries of sons as compared to daughters in a significantly higher frequency from the paternal than from maternal HLA haplotype. The results suggest that sharing of identical maternal HLA haplotypes between brothers may aid to decrease the degree of maternal sensitization to fetal antigens, and lack of HLA-2 antigen in maternal cells from sons as compared to daughters may avoid maternal HLA-A2 restricted cytotoxic reactions toward the male fetus.

Adult↗