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Biomedical subjects

R Lev

Publications and source records attributed to R Lev.

At least 37 records · Page 2Linked to original sources
PubMed1993

Neutropenic enterocolitis. Two unusual cases with review of the literature.

Cases of neutropenic enterocolitis associated with Clostridium septicum infection have been reported with increasing frequency in the past decade. We report two such cases involving unusual hosts and briefly discuss possible pathogenetic mechanisms such as ischemia, mucosal damage related to chemotherapy and neutropenia, and immunosuppression. One case involved a young man with chronic Epstein-Barr infection who developed extensive gas gangrene of the right side of his trunk and thigh and who died within 12 hours of presentation to the emergency department. Diagnosis was only made at postmortem examination. The second, middle-aged patient was admitted with an acute abdomen shortly after he completed chemotherapy for pleural mesothelioma. A right hemicolectomy was performed, but the patient developed antibiotic-associated pseudomembranous colitis and died. These cases indicate that neutropenic enterocolitis may arise in a variety of underlying conditions and that prompt diagnosis and therapy will be required to salvage more patients with this disorder.

Adult↗
PubMed1992

Relationship of polyps to cancer of the large intestine.

BACKGROUND: Pathologic and epidemiologic evidence indicates that patients with sporadic (nonfamilial) adenomatous polyps of the large intestine are at high risk of developing colorectal cancer. PURPOSE: Our primary goal in this study was to evaluate the colorectal cancer mortality rate among persons who have had a histologically confirmed benign colorectal polyp. METHODS: We used the retrospective follow-up method to evaluate the risk of death from colorectal cancer in 2872 Rhode Island men and women who were 24 through 79 years of age at the time of surgery for benign polyps in the years 1959 through 1975. RESULTS: Among 2872 subjects, the mortality from colorectal cancer, standardized for age, sex, and calendar time, was estimated as 1.74 (95% confidence interval = 1.44-2.09) times the rate in the general population of Rhode Island residents. Colorectal cancer mortality was higher in the first 5 years of follow-up than it was later. There was little relationship between the numbers of polyps and colorectal cancer mortality, and there was only a modest association between the size of polyps and mortality. Colorectal cancer mortality was more than twice as high in subjects whose polyps were proximal to the sigmoid compared with those with sigmoid or rectal polyps. The observed elevation of risk of colorectal cancer was almost entirely confined to subjects who had an adenomatous polyp. The risk increased strongly with the percentage of villous features in the polyp and was about twice as high in subjects with villous adenoma than in those with other adenomatous polyps. CONCLUSIONS: Our results support the suspected relationship between colorectal polyps and cancer incidence and extend the association to colorectal cancer mortality.

Adult↗
PubMed1992

Prevalence and properties of the intestinal alkaline phosphatase identified in serum by cellulose acetate electrophoresis.

We investigated the prevalence and characteristics of intestinal alkaline phosphatase (ALP; EC 3.1.3.1) identified in human serum by cellulose acetate electrophoresis in 8% of fasting serum samples from hospital patients (n = 500) and in 35% of fasting serum samples from patients with diabetes mellitus (n = 106; not differentiated between types 1 and 2). The intestinal ALP electrophoretic band was usually heterogeneous and contained two major subtypes of ALP. Isoelectric focusing of intestinal-ALP-positive serum treated with levamisole and neuraminidase (EC 3.2.1.18) revealed two distinct regions of enzymatic activity that comigrated with ALP extracted from small intestinal and colonic mucosa. Anodic intestinal ALP was resistant to treatment with levamisole and neuraminidase and comigrated with ALP from small intestinal mucosa. The more-cathodic intestinal ALP, which comigrated with ALP from colonic mucosa, was completely inhibited by levamisole and converted by neuraminidase to a species with a more basic pI than that of neuraminidase-digested tissue-nonspecific form. This component of intestinal ALP may be of vascular origin.

Alkaline Phosphatase↗
PubMed1991

Colonic oligosaccharide structures deduced from lectin-binding studies before and after desialylation.

Dolichos biflorus agglutinin (DBA) binds N-acetylgalactosamine (GalNAc), and peanut agglutinin (PNA) binds Gal beta(1-3)GalNAc residues (Gal = galactose). We used these lectins with neuraminidase to probe colonic oligosaccharides. Tissues included normal epithelium, adenocarcinomas (T) with contiguous transitional (TM) and normal mucosae (RM), and adenomatous polyps. Except for DBA binding in carcinomas, neuraminidase digestion increased DBA and PNA binding in all epithelia. In untreated specimens, reciprocal gradients for binding by DBA (T less than TM and TM less than RM) and PNA (T greater than TM and T greater than RM) were seen. After neuraminidase, all gradients were abolished except for T less than TM and T less than RM with DBA. We conclude that (1) qualitative as well as quantitative differences may exist between the mucins of benign and neoplastic colonic epithelium, (2) the NeuAc-GalNAc dimer is a widely prevalent terminal oligosaccharide in benign epithelium at all stages of differentiation (NeuAc = sialic acid), and (3) in contrast with evidence from recent biochemical studies, the Gal beta(1-3)GalNAc dimer is a common masked oligosaccharide in benign epithelium.

Adenocarcinoma↗
PubMed1991

Oncogenic potential of tamoxifen on endometria of postmenopausal women with breast cancer--preliminary report.

Tamoxifen (TAM), a nonsteroidal antiestrogen, is used for pre- and postmenopausal patients with breast cancer. Recent reports suggest that TAM may cause endometrial neoplasia. This study is designed to evaluate the oncogenic potential of low-dose TAM on the endometrium. Initially, endometrial screening of patients with breast cancer who had received TAM therapy for at least 12 months was conducted. Seventy patients were interviewed and office endometrial biopsies were obtained from thirty-eight patients. Seven (18%) had hyperplastic changes, ranging from simple hyperplasia through complex hyperplasia with atypia. The following prospective study was conducted: after breast surgery and prior to initiation of TAM therapy, an office endometrial sampling was obtained as a control. After initiation of TAM therapy, biopsies were repeated every 4 to 6 months as long as the patients remained asymptomatic. Nineteen patients were interviewed. Twelve patients were biopsied and followed from 3 to 15 months. One patient refused additional biopsies. Eleven patients had repeat biopsies after initiation of TAM. New hyperplastic changes were found in 3/11 (27%) patients. The preliminary results of this study (although with a small number of patients) indicate that TAM may have some neoplastic effect on the endometrium of postmenopausal patients with breast cancer. This study is still in progress. Additional prospective studies are warranted before a significant correlation between TAM and endometrial neoplasia is confirmed.

Aged↗
PubMed1990

Hanging leg weight--a rapid technique for estimating total body weight in pediatric resuscitation.

The accuracy of two methods of rapidly estimating total body weight in children was assessed. The first method correlated patient length to known total body weight, and the second correlated the weight of both legs weighted together to known total body weight. One hundred children undergoing general anesthesia in the operating rooms of Childrens Hospital of Los Angeles were entered into the study. Each child had a known preoperative body weight. After induction of anesthesia, each child's supine length was measured and hanging (inert) legs were weighted. There was excellent linear correlation between hanging leg weight and total body weight (correlation coefficient [r2], 0.95) for all patients, and good linear correlation between supine length and total body weight, r2, 0.86). Range restriction analysis for both techniques showed poor correlation for total body weights of less than 10 kg and poor correlation for the supine length technique when total body weight was more than 25 kg. The hanging leg weight of an inert child has excellent correlation to total body weight for children weighing more than 10 kg.

Adolescent↗
PubMed1989

Neoplastic Paneth cells in the stomach. Report of two cases and review of the literature.

We report two cases of gastric lesions characterized on endoscopic biopsy specimens by the extensive proliferation of Paneth cells with neoplastic characteristics. One patient with long-standing pernicious anemia developed a large polypoid carcinoma of the stomach in which the majority of malignant glands were lined by Paneth cells showing varying degrees of differentiation. The second patient developed an irregular white patch just proximal to an old gastrojejunostomy anastomosis, which revealed numerous clusters of adenomatous tubules filled with cytoplasmic Paneth granules. The "Paneth" nature of the granules was supported by the morphological, histochemical, and ultrastructural findings. These cases are unusual since neoplastic Paneth cells occur only rarely in frank adenocarcinomas or in premalignant conditions of the stomach.

Adenocarcinoma↗
PubMed1988

Abdominal CT scanning in pediatric blunt trauma.

The use of the emergency IV contrast-enhanced abdominal computed tomography (CT) scanning was evaluated in 90 pediatric patients sustaining blunt abdominal trauma. Medical records, CT scans, and operative and postmortem reports, when applicable, were reviewed retrospectively. By identifying the organs of injury, CT scans of the abdomen, with IV contrast, proved to be useful to the surgeon in deciding whether to operate in the setting of blunt abdominal trauma. The failure rate for conservative, non-operative management (four of 33) in "positive" scans was low, and represented progression of known injuries, not the appearance of unexpected injuries. Similarly, the (unplanned) surgery rate in the "negative" scan cases was low (one of 57). Abdominal CT scans cannot be relied on to consistently diagnose gastrointestinal perforation or pancreatic injury.

Abdominal Injuries↗
PubMed1985

On the difference between colonic and small intestinal alkaline phosphatase.

Colonic and small intestinal alkaline phosphatase extracts were studied biochemically and electrophoretically to elucidate the source of a reported difference in cellulose acetate electrophoretic mobility. Both preparations were inactivated with 0.5 mmol/L L-phenylalanine but retained full activity in the presence of 1.0 mmol/L tetramisole. Treatment with neuraminidase changed a minor fraction of the small intestinal but the major portion of the colonic alkaline phosphatase to a cathodically migrating form. The most likely explanation for our findings is that the colon and small intestinal alkaline phosphatase are mixtures of the same multiple forms but in different proportions.

Alkaline Phosphatase↗
PubMed1985

Histochemical and morphologic studies of mucosa bordering rectosigmoid carcinomas: comparisons with normal, diseased, and malignant colonic epithelium.

Surgically obtained rectosigmoid mucosa ("transitional" mucosa, TM) adjacent to eight primary carcinomas was compared with diseased mucosa (DM) from eight patients without primary carcinoma and mucosa from two normal control subjects by mucin histochemical and morphologic techniques. No differences were found between TM and DM that might have suggested premalignant changes unique to TM. An excess of sialidase-susceptible sialomucins was found in both TM and DM, as was loss of the sulfomucin-sialomucin gradient usually found between normal crypts and surface cells. Increased sialic acid in TM and DM may represent a nonspecific response to injury or inflammation and has been found in other epithelia under similar circumstances. Sialidase also induced substantial reduction of periodic acid-Schiff (PAS) staining, probably due to loss of sialic acid since no other sugars were released during sialidase digestion, as determined by thin-layer chromatography analysis of post-digestion supernatants. Carcinomas generally showed more staining with PAS than with basic dyes; PAS staining was minimally reduced by diastase and sialidase but markedly reduced by phenylhydrazine interposition, suggesting that some type of neutral glycoprotein was responsible. Finally, it was found that overreliance on the high-iron diamine-Alcian blue technique as a single procedure is unwise; this procedure should be accompanied by the use of singly applied dyes, especially high-iron diamine, together with other enzymatic and staining procedures.

Adenocarcinoma↗
PubMed1984

Sodium butyrate-induced alteration of growth properties and glycogen levels in cultured human colon carcinoma cells.

The effect of sodium butyrate on three cultured human colon carcinoma cell lines was studied. Exposure to butyrate caused morphological changes and resulted in the alteration of several growth properties. Doubling times of treated cells were increased five-fold and saturation densities and cloning efficiencies were decreased, compared to untreated cells. Histochemical studies using the periodic acid-Schiff reaction in conjunction with diastase digestion showed that butyrate induced increased glycogen levels in all three cell lines. This increase was confirmed by biochemical techniques. These effects of butyrate were reversed when treated cells were subsequently grown in the absence of butyrate. These changes are consistent with findings from several laboratories that butyrate can induce phenotypic changes in cultured tumour cells.

Butyrates↗
PubMed1982

Colonic and small intestinal alkaline phosphatase. A histochemical and biochemical study.

Colonic and intestinal alkaline phosphatase were studied histoenzymatically and biochemically in normal mucosae from eight hemicolectomy specimens. Histochemically, the most intense reaction was found in the small intestine, followed by vascular endothelium and colonic epithelium, respectively. The reaction was stronger in frozen sections than in acetone-fixed specimens, weakest in formalin-fixed tissues, and best when cold fixatives and low melting point paraffin were used. In the small intestine, the reaction was most marked on the villus tips. In the colon, the crypt necks showed the strongest reaction although good staining of luminal epithelium was found with more prolonged incubation. The addition of phenylalanine to the substrate medium resulted in selective inhibition of epithelial staining, whereas levamisole selectively inhibited the vascular reaction. On cellulose acetate electrophoresis, colonic and intestinal alkaline phosphatase showed slightly different rates of migration suggesting the presence of different isoenzymes. Quantitative analysis indicated that the intestinal enzyme expressed in U/g wet tissue was 7.7 times the colonic enzyme in amount. It is concluded that despite its relatively low biochemical activity, alkaline phosphatase can be demonstrated histochemically in colonic epithelium if tissues are processed at low temperatures and if the appropriate fixatives and adequate times are used.

Alkaline Phosphatase↗
PubMed1981

Precursors of human colon carcinoma: a serial section study of colectomy specimens.

All polyps and strips of colonic mucosa 1 to 15 cm from tumor margins were examined for possible precursors of carcinoma in 24 patients undergoing partial colectomy for primary colorectal adenocarcinoma. Of 114 polyps found, 40.4% were adenomatous, and the remainder were hyperplastic or inflammatory or showed normal mucosa. No primarily dysplastic lesions, which could be interpreted as early de novo carcinomas, were found. Serial sections of mucosal strips revealed minute adenomatous foci in 3 of 24 patients, one of whom also showed several patches of exclusively dysplastic epithelium. This finding suggest that carcinoma may rarely arise de novo, but most carcinomas appear to be accompanied by (? preceded by) adenomatous changes.

Adenocarcinoma↗