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Biomedical subjects

A Martin

Publications and source records attributed to A Martin.

At least 595 records · Page 33Linked to original sources
PubMed1990

Action of a mycotoxin (diacetoxyscirpenol) on the immune response of the mouse--interaction with an immunomodulator (OM-89).

The action of diacetoxyscirpenol (DAS)--a mycotoxin that belongs to the family of trichothecenes--on the immune system of the mouse was investigated. Two experimental models were used: 1) bacterial infection with Salmonella typhimurium and 2) the PFC (plaque-forming cells) test on the splenic lymphocytes of the mouse. The results obtained showed that these were dependent on the chronological order of the administration of DAS. When the toxin was administered after a bacterial infection or antigenic stimulation, it was observed an increase in the mortality rate and a very significant decrease in the antibody response. By contrast, when this mycotoxin was administered before the bacterial infection or antigenic stimulation, the results obtained were close to those from the controls. The importance of the administration of an immunomodulator of bacterial origin OM-89 before the immunodepression with DAS was shown.

Adjuvants, Immunologic↗
PubMed1990

Production traits and alloantigen systems in lines of chickens selected for high or low antibody responses to sheep erythrocytes.

The selection of chickens for high (HA) and for low (LA) antibody titers to sheep erythrocytes has produced differences in the selected trait and in the correlated responses in body weight, egg production, and erythrocyte antigens. The response to selection continued through 14 generations. There was considerable divergence between lines for erythrocyte alloantigen systems, including the major histocompatibility complex. Females from Line LA were heavier as juveniles and lighter as adults, matured at a younger age, and had higher egg production than those from Line HA. There were no differences between lines for the incidence of defective eggs laid-except for the percentage of eggs with double-yolks, which was greater for Line LA than HA. The phenotypic correlations of antibody response with growth and with reproductive traits were very low; the genetic correlations were moderate to high for most of these traits.

Alleles↗
PubMed1990

Cholestatic jaundice as the presenting symptom of small cell lung cancer.

Small-cell lung cancer is an infrequent (10%) form of lung cancer which may rarely become apparent with signs of distant metastases. A case is presented where a cholestatic syndrome was the presenting feature of a small-cell lung cancer which was not suspected clinically. The misleading clinical picture, the inaccurate results of ultrasound, ERCP and chest x-ray did not allow the correct diagnosis to be made until post mortem examination. Even according to the published experience, which is reviewed here, this presentation and clinical course appear exceedingly rare.

Bile Duct Neoplasms↗
PubMed1990

Intestinal glycosyl-transferase activities. Nutritional regulation by a chemically-modified protein: methionyl-casein.

In order to estimate the effect of a chemically modified casein, glycosylation processes were studied in rats fed a diet containing this protein. Two groups of rats were fed either a methionyl-casein diet or a normal casein diet. The methionyl-casein was enriched in methionine by covalent linkage of this amino-acid. The nutritional data (growth, protein intake...) were not modified by the diet. The microsomal N-acetylgalactosaminyl- and fucosyl-transferase activities were unaffected by the diet. On the contrary, the soluble fucosyl-transferase activity was enhanced and the activation of fucose transfer in cytosol from methionyl-casein-diet fed rats disappeared after enzyme purification by DEAE-cellulose chromatography. The activation was not explained by changes in some interfering reactions (glycosyl-nucleotide pyrophosphatase, oxidase, protease activities).

Animals↗
PubMed1990

Phase I study of combination recombinant interleukin-2 and interferon gamma in patients with advanced malignancies.

A phase I trial of interleukin-2 and interferon gamma combination treatment in patients with advanced malignancies was performed based on preclinical in vitro and in vivo data which demonstrated synergistic antitumor effect. The toxicities, immune parameters, and tumor responses are described. The clinical and biologic maximal tolerated doses were extrapolated from these data.

Adolescent↗
PubMed1990

[Bleeding of gastric ulcers. Epidemiologic, clinical and functional characteristics].

The frequency of gastrointestinal haemorrhage due to gastric ulcer has been assessed in 254 personally observed patients suffering from this endoscopically verified pathology. 56 patients, namely 22% of the cases, presented haematemesis and/or melena of the ulcerative lesion. This subgroup was compared with 65 patients with endoscopically verified gastric ulcer without previous bleeding episodes from the lesion in their clinical history, in respect of certain epidemiological, clinical and biohumoral features. The purpose of the study was to check the possible existence of clinical and/or physiopathological differences between subjects with bleeding gastric ulcer and the population of non-bleeding ulcer patients. In 80% of patients studied, the gastric ulcerous disease started with digestive haemorrhage and it was not accompanied by dyspeptic-painful symptomatology in 20% of cases. The pain symptomatology does not appear to be influenced by the intake of non-steroid anti-phlogistic drugs. No significant difference emerges between the two groups considered as regards epidemiological features and biohumoral data (PG I, gastrin, B.A.O. and M.A.O.).

Adult↗
PubMed1989

Training physicians in counseling about smoking cessation. A randomized trial of the "Quit for Life" program.

STUDY OBJECTIVE: To test whether physicians who receive a continuing education program ("Quit for Life") about how to counsel smokers to quit would counsel smokers more effectively and have higher rates of long-term smoking cessation among their patients who smoke. DESIGN: Randomized trial with blinded assessment of principal outcomes. SETTING: Four health maintenance organization medical centers in northern California. SUBJECTS: Eighty-one internists assigned by blinded randomization to receive training (40) or serve as controls (41). Consecutive samples of smokers visiting each physician (mean, 25.6 patients per experimental and 25.2 per control physician). INTERVENTIONS: Internists received 3 hours of training about how to help smokers quit. Physicians and their office staff also were given self-help booklets to distribute free to smokers and were urged to use a system of stickers on charts to remind physicians to counsel smokers about quitting. MEASUREMENTS AND MAIN RESULTS: On the basis of telephone interviews with patients after visiting the physician, we determined that internists who attended the Quit for Life program discussed smoking with more patients who smoked, spent more time counseling them about smoking, helped more patients set dates to quit smoking, gave out more self-help booklets, and made more follow-up appointments to discuss smoking than did internists in the control group. One year later, the rate of biochemically confirmed, long-term (greater than or equal to 9 months) abstinence from smoking was 1% higher among all patients of trained internists than among patients of controls (95% CI, -0.1% to +2.3%), and 2.2% (+0.2% to +4.3%) higher among the patients who most wanted to quit smoking. CONCLUSIONS: This continuing education program substantially changed the way physicians counseled smokers. As a result, a few more patients who wanted to quit smoking achieved long-term abstinence.

Attitude of Health Personnel↗
PubMed1989

Predicting the solubility of sulfamethoxypyridazine in individual solvents. I: Calculating partial solubility parameters.

Sulfamethoxypyridazine, a representative model of a drug molecule, is used to test the extended Hansen method for estimating partial solubility parameters of solid compounds. Solubilities are determined in polar and nonpolar solvents. The method provides reasonable partial parameters for the sulfonamide, and it may be useful in obtaining partial parameters for other drug molecules. A four-parameter extended Hansen approach involving proton donor and acceptor parameters is used in fitting the data to a theoretical model. A term, Wh, is introduced as an empirical measure of solute-solvent interactions due to hydrogen bonding. The use of the empirical term Wh allows the researcher to fit experimental solubilities and thus design regression models and equations which provide a reasonable prediction of solubilities of a polar drug in a number of very different solvents. A Flory-Huggins size correction term improves the prediction of sulfamethoxypyridazine solubilities in these irregular solutions.

Chemical Phenomena↗
PubMed1989

Predicting the solubility of sulfamethoxypyridazine in individual solvents. II: Relationship between solute-solvent interaction terms and partial solubility parameters.

In the first paper in the series, an expanded system of parameters was devised to account for orientation and induction effects, and the term Wh was introduced to replace delta 1h delta 2h of the extended Hansen solubility approach. In the present report, a new term, Kh = Wh/delta 1h delta 2h is observed to take on values larger or smaller than unity depending on whether the hydrogen bonded solute-solvent interaction is larger or smaller than predicted by the term delta 1h delta 2h. The acidic delta a and basic delta b solubility parameters are used to represent two parameters, sigma and tau, suggested by Small in his study of proton donor-acceptor properties. The Small equation, including a heat of mixing term for hydrogen bonded species, is shown to be capable of semiquantitative evaluation. A partial molar heat delta H2h of hydrogen bonding is calculated using delta h and Wh terms; delta H2h is found to be correlated with the logarithm of the residual activity coefficient, In alpha R, a term representing strong solute-solvent interaction. The terms Wh, delta H2h, and In alpha 2R may be used to test the deviation from the geometric mean assumed in regular solution theory, and to replace the hydrogen bonding terms of the extended Hansen three-parameter model. The solubility of sulfamethoxypyridazine in 30 solvents is used to test the semiempirical solubility equations. The results are interpreted in terms of partial solubility parameters and the proton donor-acceptor properties of the solvents.

Chemical Phenomena↗
PubMed1989

Study of C. burnetii human and animal seroprevalence in a rural population in Madrid community.

A pilot study on human seroprevalence of antibodies to C. burnetii in the Madrid region, initiated in a small rural population, shows a 15.4% positivity by the indirect immunofluorescence test. An urban sample shows an 8.8% positivity. Animal seroprevalence in livestock located in the village under study is 76.6% in caprine and 17.7% in bovine. A high risk epidemiological situation is detected.

Animals↗
PubMed1989

Characterization of the antigen identified by Po66. A monoclonal antibody raised against a lung squamous cell carcinoma.

The mouse monoclonal antibody (mAb) Po66 has been shown in previous work to be localized in nude mice xenografts of human lung tumours when injected intravenously [Dazord L et al. (1987) Cancer Immunol Immunother 24: 263-268] and to be suitable for the scintigraphic detection of lung cancers in patients [Dazord L, et al. (1987) in Klapdor (ed) New tumour markers and their monoclonal antibodies. Georg Thieme, Stuttgart, New York, pp 444-450]. The nature of the antigen recognized by Po66 has been investigated in the present work and comparisons are made with antigens recognized by other mAbs prepared in the laboratory. These mAbs were raised either against lung squamous cell carcinoma (mAbs Po43, Po60), or against a bronchio-alveolar carcinoma (mAbs BAM33, BAM45, BAM54 and BAM69). Radioiodinated purified Po66 did not compete for cell binding with any other mAb. All Po and BAM mAbs reacted with tumour cells both cultured in vitro and grown in vivo. They recognized cytoplasmic antigens as judged by immunofluorescence examination of fixed cells or by immunoperoxidase staining of cancer tissues, but could never be visualized by immunofluorescence on the surface membrane of culture cells. The mAbs of the BAM series reacted with vimentin as demonstrated by immunofluorescence staining, showing alterations in the aspect of the filaments under the effect of colchicine. Radiolabelled mAbs Po43, BAM33 and BAM45 bound to partially purified cytoplasmic cytoskeleton components. In contrast, Po66 was never seen associated with intermediary filaments. The sensitivity to enzyme digestion of the antigen associated with Po66 was studied in comparison with those associated with Po43, BAM33 and BAM45. All antigens were sensitive to protease digestion while only the Po66-identified antigen was sensitive to periodate, neuraminidase and alpha-fucosidase. Thus, mAb Po66 identified an antigen of 47 kDa (as determined before) present in the cytoplasm but not related to the cytoskeleton, not detected on the cell surface and glycoprotein in nature.

Adenocarcinoma↗
PubMed1989

Distribution of radiolabelled monoclonal antibody Po66 after intravenous injection into nude mice bearing human lung cancer grafts.

Monoclonal antibody Po66, produced by immunization against a patient's lung squamous cell carcinoma was found suitable for the scintigraphic detection of human tumours. Surprisingly, the cellular antigen recognized by Po66 was abundant in the cytoplasm of tumour cells but could not be detected on the surface membrane. In the present work the biodistribution of radiolabelled Po66 and of an unrelated immunoglobulin were studied comparatively after intravenous injection into nude mice bearing lung squamous cell carcinoma grafts. Radioactivity distribution among mouse organs and tumour was analysed by gamma counting and autohistoradiography. After injection, radiolabelled Po66 decreased rapidly from the blood in tumour-bearing animals whereas, in controls, it remained at a level comparable to that of the unrelated immunoglobulin. The antibody seemed slowly trapped by the tumour and, 12 days after its injection, distribution ratios between tumour and mouse organs reached values of 20-30 as against 1 in animals injected with the non-specific immunoglobulin. Autohistoradiographic investigations in the tumour confirmed the slow diffusion rate of the antibody, which remained in the vascular spaces up to the 24th hour after injection and diffused afterwards throughout the clusters of tumor cells. Furthermore, radioactivity was detected in cells which, unexpectedly, seemed morphologically unaltered. These cells, the viability of which remains to be determined, were predominant in the central area of the tumours. The results presented constitute new evidence of the ability of an in vivo injected monoclonal antibody to reach a cytoplasmic target inside non-necrotic cells and suggest that the cells permeable to the antibody might be in defective nutritional conditions.

Animals↗