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Biomedical subjects

J Baron

Publications and source records attributed to J Baron.

At least 181 records · Page 10Linked to original sources
PubMed1985

Presenting conditions of 1539 population-based lung cancer patients by cell type and stage in New Hampshire and Vermont.

The authors identified all newly diagnosed lung cancer cases in New Hampshire and Vermont for the period 1973 through 1976 and abstracted clinical data on presenting symptoms and findings from their hospital records. Microscopy slides were also reviewed, when possible, to confirm cell type. The most frequent presenting symptoms were weight loss (46%) and cough (45%). Other common symptoms were dyspnea (37%), weakness (34%), chest pain (27%), and hemoptysis (27%). The presence of symptoms and findings was in general related to disease stage but bore little relationship to cell type. These results differ from those of previously reported case series that were based on surgical, radiation therapy, or Veterans Hospital groups, but the current data agree closely with those from another population-based series in Finland.

Adenocarcinoma↗
PubMed1985

Localization of a cytochrome P-450 isozyme (cytochrome P-450 PB-B) and NADPH-cytochrome P-450 reductase in rat nasal mucosa.

Antibodies raised against cytochrome P-450 PB-B, the major phenobarbital-inducible isozyme of rat hepatic microsomal cytochrome P-450, and NADPH-cytochrome P-450 reductase (EC 1.6.2.4) were employed to determine the cellular localizations of these enzymes within the nasal mucosa of untreated rats. Immunohistochemical staining for each enzyme was detected at the light microscopic level within the respiratory and olfactory epithelia, duct and acinar cells of seromucous glands in the respiratory region, and duct and acinar cells of Bowman's glands in the olfactory region. These findings demonstrate that a number of different cell types in rat nasal mucosa contain enzymes which participate in the monooxygenations of chemical carcinogens and other xenobiotics.

Animals↗
PubMed1985

Processes underlying formal thought disorder in psychiatric inpatients.

Three theories about the cognitive processes underlying symptoms of formal thought disorder in psychiatric inpatients were tested. Chapman and Chapman's "excessive yielding to normal bias" theory and a response competition theory were tested by using two ambiguity tasks. Chapman and Chapman's bias theory predicts a smaller ambiguity effect for thought-disordered patients; a response competition hypothesis predicts a larger ambiguity effect. Results showed no difference between thought-disordered and non-thought-disordered patients. To test a distractibility theory of thought disorder, subjects performed a Stroop-type task in which they counted the number of digits (e.g., 3333) or symbols (####) in a set. Thought-disordered patients did show an increased effect of the presence of the digits, and this finding was replicated in a second inpatient sample. Thus, results were consistent with the distractibility theory and with a reformulation of the bias theory, in which the bias shown by thought-disordered patients is not a tendency toward a particular response, but rather toward a particular rule, or set, for responding.

Adult↗
PubMed1984

Localization of epoxide-metabolizing enzymes in rat testis.

Antibodies raised against rat hepatic epoxide hydrolase (EC 3.3.2.3) and glutathione S-transferases (EC 2.5.1.18) B, C and E were used to determine the presence and localizations of these epoxide-metabolizing enzymes in testes of sexually immature and mature Wistar and Holtzman rats. Unlabeled antibody peroxidase-antiperoxidase staining for each enzyme was readily detected in rat testes at the light microscopic level. Although significant strain-related differences were not apparent, staining intensity for certain enzymes differed markedly between Leydig cells and seminiferous tubules. Leydig cells of immature and mature rats were stained much more intensely for epoxide hydrolase and glutathione S-transferases B and E than were seminiferous tubules, whereas Sertoli cells, spermatogonia, spermatocytes and spermatids, as well as Leydig cells, were stained intensely by the anti-glutathione S-transferase C. Age-related differences in staining for glutathione S-transferase B were not obvious, while the anti-glutathione S-transferase C stained seminiferous tubules more intensely in immature rats, and antibodies to epoxide hydrolase and glutathione S-transferases C and E stained Leydig cells much more intensely in mature rats. These observations thus demonstrate that testes of both sexually immature and mature rats contain epoxide hydrolase and glutathione S-transferases. Except for glutathione S-transferase C in immature rats, Leydig cells appear to contain much higher levels of enzymes than do seminiferous tubules. During sexual maturation, the testicular level of glutathione S-transferase B appears to remain constant, while levels of epoxide hydrolase and glutathione S-transferases C and E increase within Leydig cells and the level of glutathione S-transferase C decreases within seminiferous tubules.

Animals↗
PubMed1984

Lipase turbidimetric assay and acute pancreatitis.

The simplified turbidimetric assay for lipase activity was used for the differential diagnosis of acute pancreatitis. Serum lipase levels were found to be increased in a group of 17 patients in whom acute pancreatitis was clinically suspected and confirmed by a high ACCR and decreased uptake of the radionuclide in the pancreas scan. The lipase levels were within normal limits in a control group of 14 patients suffering from diseases other than acute pancreatitis. The turbidimetric test was helpful for rapid quantitative determination of serum lipase and thus for the early and accurate diagnosis of acute pancreatitis.

Acute Disease↗
PubMed1984

Immunohistochemical localization of carcinogen-metabolizing enzymes within the rat and hamster exocrine pancreas.

The P-450 cytochromes, reduced nicotinamide adenine dinucleotide phosphate-cytochrome P-450 reductase, epoxide hydrolase, and glutathione S-transferases all play important roles in the bioactivation and detoxication of various classes of chemical mutagens and carcinogens. The present investigation was undertaken to determine if and where these enzymes are located within the exocrine pancreas, a tissue that is a target for chemically induced neoplasia. In this study, reduced nicotinamide adenine dinucleotide phosphate-cytochrome P-450 reductase, two isozymes of cytochrome P-450 (cytochromes P-450 PB-B and BNF-B), epoxide hydrolase, and glutathione S-transferases B, C/A, and E were each localized at the light microscopic level within exocrine pancreases of untreated rats and hamsters utilizing the unlabeled antibody peroxidase-antiperoxidase staining technique. Immunohistochemical staining for each of these enzymes was apparent within acinar cells in pancreases of Holtzman, Sprague-Dawley, Wistar, and Fischer 344 rats. Staining for the reductase, the epoxide hydrolase, and the glutathione S-transferases was also observed within the epithelia of both interlobular and intralobular ducts in the exocrine pancreases of these rat strains, whereas staining for cytochromes P-450 PB-B and BNF-B was not readily detectable within epithelial cells of the rat pancreatic duct system. In the exocrine pancreas of the Syrian golden hamster, immunohistochemical staining for reduced nicotinamide adenine dinucleotide phosphate-cytochrome P-450 reductase, epoxide hydrolase, and glutathione S-transferases B and C/A was similar to that observed within the rat exocrine pancreas. In contrast, acinar and duct cells in the hamster pancreas both appeared to be stained for cytochrome P-450 PB-B, whereas staining for cytochrome P-450 BNF-B could not be readily detected within either acinar or duct cells, and staining for glutathione S-transferases E did not appear to be present within duct cells in the hamster pancreas. The results of this investigation therefore suggest that highly reactive and toxic electrophilic metabolites of procarcinogens may be generated to the greatest extent within acinar cells in the rat pancreas, whereas these metabolites may be produced within both acinar and duct cells in the hamster pancreas. Regardless of where they are formed, reactive metabolites may be enzymatically detoxicated within both acinar and duct cells in the rat and hamster exocrine pancreas.

Animals↗
PubMed1983

Effects of phenobarbital, trans-stilbene oxide, and 3-methylcholanthrene on epoxide hydrolase within centrilobular, midzonal, and periportal regions of rat liver.

The effects of phenobarbital, trans-stilbene oxide, and 3-methylcholanthrene on epoxide hydrolase (EC 3.3.2.3) within centrilobular, midzonal, and periportal hepatocytes were investigated employing rabbit anti-serum produced against rat hepatic microsomal epoxide hydrolase in unlabeled antibody peroxidase-anti-peroxidase and indirect fluorescent antibody-staining techniques. In livers of control rats, midzonal and periportal hepatocytes bound the anti-epoxide hydrolase to similar extents while centrilobular hepatocytes bound approximately 25% more antibody. 3-Methylcholanthrene did not cause significant alterations in immunohistochemical staining for epoxide hydrolase within any region of the liver lobule, whereas phenobarbital and trans-stilbene oxide produced significant alterations in both the intensity and pattern of intralobular staining for the enzyme. After 4 days of phenobarbital pretreatment, anti-epoxide hydrolase binding to hepatocytes was slightly, but significantly, elevated, especially within midzonal regions. After 7 days of phenobarbital pretreatment, anti-epoxide hydrolase binding was increased by approximately 65% within midzonal regions and by approximately 41 and 24%, respectively, within centrilobular and periportal regions. In livers of trans-stilbene oxide-pretreated rats, anti-epoxide hydrolase binding was increased by approximately 80% within both the midzonal and periportal regions and by approximately 43% within centrilobular regions. These immunohistochemical findings demonstrate that phenobarbital and trans-stilbene oxide both induce epoxide hydrolase nonuniformly within the liver lobule. However, while phenobarbital induces the enzyme to the greatest extent within midzonal hepatocytes and to the least extent within periportal hepatocytes, trans-stilbene oxide induces epoxide hydrolase equally within midzonal and periportal hepatocytes.

Animals↗
PubMed1983

Oral contraceptives and breast cancer: final report of an epidemiological study.

During 1968-1980, 1176 women aged 16-50 years with newly diagnosed breast cancer and a like number of matched controls were interviewed at 9 teaching hospitals in London and Oxford and asked about their use of oral contraceptives. The results were reassuring. A few statistically significant differences in oral contraceptive use were found between the breast cancer and control groups, but the data were subdivided in many ways so that some "significant" differences would have been expected through the play of chance alone. Certainly no patterns of risk emerged which would suggest that any of the associations were causal. It must be stressed, however, that the data are still sparse in some important subcategories--for example, only small numbers of both cases and controls had prolonged oral contraceptive use before their first term pregnancy. For this reason, it is important that information on the possible relationship between pill use and breast cancer should continue to be collected. Women who had never used oral contraceptives presented with appreciably more advanced tumours than those who had been using oral contraceptives during the year before detection of cancer, while past users were in an intermediate position. These differences in staging were reflected in the pattern of survival. Possible explanations for these observations include "surveillance bias" among oral contraceptive users leading to earlier diagnosis and a beneficial biological effect of oral contraceptives on tumour growth and spread. Women with breast cancer reported never having used any method of contraception and heavy cigarette smoking (greater than or equal to 15 per day) significantly less often than controls. We could find no obvious explanation for the former observation, but suspect that the latter reflects the unrepresentative smoking habits of our hospital controls rather than a protective effect of smoking against breast cancer.

Adolescent↗
PubMed1983

Quantitative immunohistochemistry: a comparison of microdensitometric analysis of unlabeled antibody peroxidase-antiperoxidase staining and of microfluorometric analysis of indirect fluorescent antibody staining for nicotinamide adenosine dinucleotide phosphate (NADPH)-cytochrome c (P-450) reductase in rat liver.

The intralobular distribution of nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome c (P-450) reductase (NADPH:ferricytochrome oxidoreductase, EC 1.6.2.4) in rat liver has been investigated by means of two quantitative immunohistochemical techniques: microdensitometric quantitation of unlabeled antibody peroxidase-antiperoxidase staining and microfluorometric analysis of indirect fluorescent antibody staining. Utilizing sheep antiserum elicited against NADPH-cytochrome c (P-450) reductase that had been isolated and purified to apparent homogeneity from rat liver microsomes, the reductase was detected within hepatocytes throughout the liver. However, differences in the intensity of staining of hepatocytes within different regions of the liver lobule were readily apparent after completion of both immunohistochemical staining procedures. These visual findings were verified by microdensitometric and microfluorometric analyses of immunohistochemical staining, both of which revealed that approximately the same degree of staining for NADPH-cytochrome c (P-450) reductase was produced within the centrilobular and midzonal regions of the liver lobule, whereas periportal hepatocytes were stained with significantly less intensity. These results demonstrate that the application of either microdensitometry in conjunction with unlabeled antibody peroxidase-antiperoxidase staining or microfluorometry after indirect fluorescent antibody staining can be used to quantitatively determine the intratissue distributions of antigens.

Animals↗