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Biomedical subjects

J A Bombi

Publications and source records attributed to J A Bombi.

At least 19 recordsLinked to original sources
PubMed1996

Localization of monoamine oxidases in human peripheral tissues.

Localization of monoamine oxidases (MAO) A and B and beta-adrenoceptors, was studied in aged human peripheral tissues (age 68-80 years) by quantitative autoradiography. The tissues analyzed were heart, lung, liver, kidney, spleen and duodenum. [3H]Ro41-1049 and [3H]lazabemide, two recently characterized selective radioligands were used to map MAO-A and MAO-B respectively. The regional pattern of distribution of MAO-A and MAO-B did not differ markedly, except in kidney and especially in duodenum. Highest levels of MAOs were measured in liver, and lowest in spleen. MAO-A was more abundant than MAO-B in lung and duodenal mucosa, and the reverse was true in myocardium. These results show marked differences in the abundance and patterns of distribution of MAOs, particularly MAO-B, in human and rodent peripheral tissues.

Aged↗
PubMed1996

Effects of prolonged ethanol intake and malnutrition on rat pancreas.

Nutritional factors, especially the protein and fat content of the diet, may change pancreatic morphology after ethanol induced injury. This study was performed to delineate the combined effects of a low fat diet and longterm ethanol ingestion on the rat pancreas. Male Sprague-Dawley rats were maintained with five different diets for 12 weeks and the pancreas removed on the day they were killed. Rats fed a very low fat diet without ethanol (5% of total calories as lipid) developed malnutrition, pancreatic steatosis, and reduction in zymogen granules content. Animals fed a 35% lipid diet with ethanol also developed pancreatic steatosis but changes in zymogen granules content were not detected. Both malnutrition and longterm ethanol consumption increased pancreatic cholesterol ester content, and their effects were additive. Pancreatic steatosis was accompanied with hypercholesterolaemia. Amylase, lipase, and cholesterol esterase content were reduced in malnourished rats; but longterm ethanol ingestion, regardless of the nutritional state, increased lipase content and decreased amylase. It is suggested that high serum cholesterol concentrations and increased pancreatic lipase activity could cause accumulation of cholesterol esters in acinar cells. Fat accumulation in the pancreas has been reported as the earliest histopathological feature in alcoholic patients and may be responsible for cytotoxic effects on the acinar cells at the level of the cell membrane. Although it is difficult to extrapolate results in this animal study to the human situation, the results presented in this work might explain the higher incidence of pancreatitis is malnourished populations as well as in alcoholic subjects that is reported in dietary surveys.

Animals↗
PubMed1995

Cyclospora in patients with traveller's diarrhea.

Following the description in 1986 of a new enteropathogen called Cyanobacteria-like body (CLB), several outbreaks caused by this microorganism have been described. Since then several research teams have agreed to place CLB in the genus Cyclospora and to establish the epidemiological, pathogenical and clinical features of the illness. This paper describes and assesses those features in 20 travellers diagnosed with CLB and reviews the main literature concerning this enteropathogen. CLB was found in 2.8% of all cases of traveller's diarrhea in our series.

Adult↗
PubMed1994

Spectrum of glandular differentiation in experimental carcinoma of the esophagus induced by 2,6-dimethylnitrosomorpholine under the influence of esophagojejunostomy.

To investigate the influence of reflux esophagitis (RE) on the glandular differentiation of carcinomas of the esophagus induced by 2,6-dimethylnitrosomorpholine (2,6-DMNM), a study was carried out using 4 experimental groups and 2 control groups of 8-week-old Sprague-Dawley rats, each consisting of 20 males and 20 females. An esophagojejunostomy (EJ) with gastric preservation was performed in two groups of animals. Fifteen days thereafter the potent esophagotropic carcinogen 2,6-DMNM was subcutaneously injected, once a week for life, at doses of 1/100 and 1/10 of the 50% lethal dose in each group respectively. The result was a spectrum of carcinomatous tumors mainly developing in the lower half of the esophagus, which were thoroughly investigated by serial sectioning, staining for mucins, and in selected cases by electron microscopy. They were classified as follows: 16 pure squamous cell carcinomas (SCC), 5 SCC with focal mucous or glandular differentiation (FGD), 11 pure adenocarcinomas (ADC), and 12 ADC with areas of squamous cell differentiation (SCD). By contrast, in 2 similar experimental groups in which the previous EJ was not performed, 15 animals showed SCC of the pure type, without evidence of mucous or glandular differentiation. No tumors were observed in the two control groups without carcinogen treatment. Of these, the group that underwent EJ showed reflux esophagitis. In conclusion, the tumors of the esophagus induced by 2,6 DMNM under the influence of EJ are not only pure ADC and pure SCC, as we have previously reported, but also intermediate tumors showing either SCC with focal mucous or glandular differentiation (SCC + FGD) or ADC with areas of squamous cell differentiation (ADC + SCD).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

Cyanobacteria-like body (CLB) in travellers with diarrhea.

The cyanobacteria-like body (CLB) is a recently described agent, causing a travellers' disease (TD) syndrome characterized mainly by diarrhea. It has been described in travellers who have visited Asia and Latin America. We report 6 cases seen over a 16-month period among those attending a travellers' clinic. All patients suffered from fatigue, watery diarrhea and abdominal cramps; some also lost weight. The episodes were recurrent.

Adult↗
PubMed1992

A one-minute oxidase test to detect Vibrio strains isolated from cultures on thiosulphate-citrate-bile salts-sucrose (TCBS) medium.

Vibrio cholerae is oxidase positive, a primary characteristic used to differentiate it from Enterobacteriaceae. But false negative oxidase test results have been obtained with colonies from thiosulphate-citrate-bile salts-sucrose (TCBS) agar medium. A rapid oxidase test procedure is described here. This takes 1 min, avoids false negative results and the necessity to grow the bacteria in a general-purpose medium. The bacteria may be recovered after the test and used for further investigations.

Culture Media↗
PubMed1992

Pathology of bone marrow transplantation.

For evaluating the therapeutic approaches in the follow-up and complications of patients treated with bone marrow transplantation (BMT), the histopathology is important on many occasions. The authors describe the different morphological changes that have an important role for treatment of these patients, classified according to their target organs of localization: skin, digestive tract, liver, and bone marrow. Graft-versus-host disease (GVHD) mainly affects the skin, gastrointestinal tract, and liver, and is sometimes difficult to differentiate from radiochemotherapy or infectious diseases. In the liver, the most frequent complications are GVHD, veno-occlusive disease, and infections. In the bone marrow, it is most important to evaluate the elimination of hemopathy and the reconstitution of normal hematopoiesis.

Bone Marrow Transplantation↗
PubMed1992

[Role of the amniotic fluid in gastroschisis. An experimental study].

The short and thick bowel found in gastroschisis has been attributed to contact with amniotic fluid, among other factors. We designed an original animal model in order to isolate the effect of amniotic fluid on the fetal bowel. We created experimental gastroschisis in fetal rabbits. Extruded bowel was kept out of the amniotic sac in half of the operated fetuses. At term, seven days after surgery, 21 surviving fetuses--12 intra-amniotic (GIA) and nine extra-amniotic (GEA)--and 16 control littermates were harvested for study. Five parameters were measured in each animal: body weight, intestinal weight, intestinal length, bowel diameter and bowel wall thickness. We found no statistically significant difference in body weight, intestinal weight or bowel wall thickness. An enormous difference was found in intestinal length among the three groups. Bowel diameter was significantly different in the extreme groups (GIA and controls), with the intestine being more dilated in GIA than in GEA and controls. Gastroschisis in the absence of amniotic fluid has not been as damaging to the fetal intestine as "natural" intraamniotic gastroschisis.

Abdominal Muscles↗
PubMed1992

In vitro spontaneous synthesis of beta 2-microglobulin amyloid fibrils in peripheral blood mononuclear cell culture.

beta 2-microglobulin-related amyloidosis (A beta 2M), in long-term dialysis patients, is a new and frequent complication for which the pathogenesis remains unknown. The authors documented, by light and high resolution electron microscopy, the spontaneous polymerization of beta 2-microglobulin to amyloid fibrils in mononuclear cell culture supernatants from dialysis patients. These data provide significant information about the pathogenesis of dialysis-amyloidosis, revealing an unusual and different fibrillogenic mechanism for beta 2-microglobulin and dialysis-amyloidosis than for other forms of amyloidosis. beta 2-microglobulin does not appear to require a proteolytic process before polymerization into amyloid fibrils and deposits. This study represents the first cell culture system in which beta 2-microglobulin amyloid fibrils have been spontaneously created.

Amyloid↗
PubMed1991

Primary localized cutaneous amyloidosis and familial medullary thyroid carcinoma.

We have studied a family with an autosomal dominant inheritance of primary localized cutaneous amyloidosis (PLCA) and familial medullary thyroid carcinoma (MTC). Ten family members were screened for multiple endocrine neoplasia (MEN) 2; five were found to have MTC and two had C-cell hyperplasia. None had evidence of phaeochromocytoma or parathyroid abnormalities. Five of these seven patients presented characteristic interscapular hyperpigmented lesions, showing dermal amyloid deposits in two of the four patients in which a biopsy was performed. The data are analysed in the light of two recent reports of MEN 2A associated with identical lesions. We conclude that PLCA should be sought in MTC patients, even if no other endocrinopathies are present. This may be informative of the familial character of MTC in index cases and also of the tumour gene status in family members who are being screened.

Adult↗
PubMed1990

[Multiple familial trichodiscoma].

Trichodiscomas are hamartomas of the pilar apparatus, and have been described alone or associated to other benign proliferations of the pilar complex. Two familial cases of trichodiscomas not associated to pilar alterations or systemic manifestations are described.

Adult↗
PubMed1989

Influence of esophagojejunostomy on the induction of adenocarcinoma of the distal esophagus in Sprague-Dawley rats by subcutaneous injection of 2,6-dimethylnitrosomorpholine.

To study the influence of reflux esophagitis on the carcinogenic response of 2,6-dimethylnitrosomorpholine (2,6-DMNM), an experiment was designed, composed of 6 groups of 8-week-old Sprague-Dawley rats, each consisting of 20 males and 20 females. Group 1 served as untreated controls. All animals of groups 2, 4, and 6 underwent an esophagojejunostomy with gastric preservation to produce a chronic reflux esophagitis. 2,6-DMNM was injected s.c. once weekly for life at doses of 1/100 and 1/10 of the 50% lethal dose to groups 3 and 4 and groups 5 and 6, respectively. Carcinogen exposure began in groups 4 and 6 15 days after the esophagojejunostomy. Squamous cell carcinomas were observed in the esophagus of 36 animals, mainly in those receiving the higher dose. Exophytic squamous cell carcinomas, a variety rarely seen in humans, were mostly seen in the groups receiving 2,6-DMNM alone, whereas endophytic squamous cell carcinomas, the variety most frequently seen in humans, mainly developed in the groups receiving the combined treatment. In addition adenocarcinomas with abundant mucin production were found in the distal esophagus of 23 animals. They were found exclusively in animals of groups 4 and 6 which underwent esophagojejunostomy plus 2,6-DMNM exposure. No adenocarcinomas were encountered in groups without experimental reflux esophagitis. These findings may contribute to further understanding of the association between reflux esophagitis and the various histological types of esophageal carcinoma in humans.

Adenocarcinoma↗
PubMed1989

Comparison of snare and large forceps biopsies in the histologic diagnosis of gastric vascular ectasia in cirrhosis.

To compare snare and large forceps biopsies in the histologic diagnosis of gastric vascular ectasia (GVE) in cirrhosis, two groups of patients were studied: (a) 8 cirrhotic patients in whom endoscopy disclosed multiple gastric red spots (GRS), and (b) 5 cirrhotic patients with no GRS. Histologic examination of snare specimens identified dilated capillaries in the mucosa of the stomach in 75% of the cirrhotic patients with GRS, while large forceps specimens enabled the diagnosis of GVE only in 20% of the cases (p less than 0.05). Morphometric analysis of snare specimens demonstrated a significantly greater mean mucosal capillary cross-sectional area in cirrhotic patients with GRS than in cirrhotic patients without these lesions (p less than 0.05), while no differences in this parameter was observed in large forceps specimens. These findings indicate that gastric mucosal specimens obtained with large forceps are not useful for establishing the histologic diagnosis of GVE in cirrhotic patients with GRS.

Aged↗
PubMed1989

Morphologic and morphometric light and electron microscopic studies of the spleen in patients with hereditary spherocytosis and autoimmune haemolytic anaemia.

With the aim of contributing to a better understanding of the haemolytic function of the spleen, a morphologic and morphometric study of this organ fixed by arterial perfusion was performed in nine patients with hereditary spherocytosis (HS), three with autoimmune haemolytic anaemia (AHA) and six with Hodgkin's disease without splenic involvement (controls). The spleen weight in HS and AHA (621 +/- 429 g, mean +/- SD) was significantly increased with respect to controls (168 +/- 36 g) (P = 0.003). In HS the red cell retention in the cords of Billroth was significantly increased (203 +/- 68 per 10(4) microns 2) with respect to the cases with AHA (93 +/- 35 per 10(4) microns 2) and to the controls (57 +/- 28 per 10(4) microns 2) (P = 0.004). In HS and AHA the number of macrophages per 10(4) microns 2 of red pulp was significantly increased (5.41 +/- 1.10 and 7.52 +/- 2.91, respectively) with respect to the controls (3.25 +/- 0.58) (P less than 0.003). There was no statistically significant difference between the number of macrophages in HS and AHA. The transmission (TEM) and scanning electron microscopy (SEM) studies demonstrated predominantly red cell retention in the cords of HS spleens, red cell phagocytosis by cordal macrophages in AHA spleens and in a lesser intensity in HS spleens, and phagocytosis of haematic corpuscles by sinus endothelial cells (SEC) in the cases of HS. These quantitative studies allow a better understanding of splenic red cell destruction in haemolytic syndromes.

Adolescent↗
PubMed1988

Polyps of the colon in Barcelona, Spain. An autopsy study.

This study is based on a prospective survey of 212 autopsies that was conducted to determine the prevalence of colon adenomas in Barcelona, Spain. Adenomatous polyps were found in 21.7% of the patients (29.3% of the men and 12.5% of the women); multiple adenomas were found in 40% of the patients. Almost all adenomas were less than 5 mm in diameter, although 6.7% of the ones seen predominantly in the rectosigmoid colon were larger than 1 cm. The prevalence and number of adenomas increases with age. The prevalence of hyperplastic polyps was very low (1.6%). The data shows a relationship between the prevalence of colon adenomas in Spain and the incidence of colon cancer. The prevalence of colon adenomas in Spain is one of the lowest compared with that in other European countries and North America.

Adenoma↗
PubMed1987

Gastric mucosal vascular ectasias causing bleeding in cirrhosis. A distinct entity associated with hypergastrinemia and low serum levels of pepsinogen I.

To characterize bleeding from gastric red spots in patients with cirrhosis, three groups of patients were studied: (a) 11 cirrhotic patients bleeding from gastric red spots, (b) 18 nonbleeding cirrhotic patients without gastric red spots, and (c) 13 noncirrhotic patients with endoscopic normal mucosa (controls). Histologic examination of antral biopsy specimens revealed a diffuse capillary ectasia without inflammation in 8 of the 11 cirrhotic patients with gastric lesions. Morphometric analysis disclosed a significantly greater mean mucosal capillary cross-sectional area in cirrhotic patients with gastric lesions (mean +/- SE, 1371 +/- 320 microns2) than in those without gastric lesions (541 +/- 61 microns2) (p less than 0.005) or controls (353 +/- 20 microns2) (p less than 0.001). Hypergastrinemia was detected in 8 of the 11 cirrhotic patients with lesions, in 2 of the 18 cirrhotic patients without gastric lesions, and in none of the controls (p less than 0.001). Gastrin serum levels correlated significantly (r = 0.80) with mean mucosal capillary cross-sectional area in patients with cirrhosis. Pepsinogen I serum levels below 20 ng/ml were observed in 7 of the 11 cirrhotic patients with lesions, in 1 of the 18 cirrhotic patients without lesions, and in none of the controls. These data indicate that bleeding from gastric red spots in patients with cirrhosis is a distinct entity characterized by vascular ectasia of the gastric mucosa. This condition seems to be associated with hypergastrinemia and low serum levels of pepsinogen I.

Capillaries↗
PubMed1987

[PUVA therapy: long-term degenerative effects. II. Study of ultrastructural changes in the skin induced by PUVA therapy].

The authors studied PUVA induced ultrastructural alterations in a group of 7 patients compared with 6 control subjects of same age. Hyperactivity of melanocytes was observed in all patients. Elastic fibers showed vacuolisation age and dose related. There was a reduplication of the basal layer of dermal capillaries and increased pinocytosis of endothelial cells, age and dose related also. The authors conclude that PUVA therapy induced alterations are degenerative; the target is located in deep dermis (capillaries and elastic fibers). No alterations of keratinocytes nor precancerous epithelial dysplasia was found. This confirms that UVA radiation is less aggressive for keratinocytes than UVB.

Adult↗