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Biomedical subjects

M Biernat

Publications and source records attributed to M Biernat.

18 recordsLinked to original sources
PubMed2003

Exogenous leptin controls the development of the small intestine in neonatal piglets.

Leptin, a hormone produced and secreted by adipose tIssue, muscles and stomach, is involved in the regulation of adipose tIssue mass, food intake and body weight in neonatal animals. It is also produced in the mammary glands and secreted into the colostrum and milk. Since leptin receptors are widely distributed in the small intestine mucosa, the aim of the present study was to investigate the effect of exogenous leptin on the development of the small intestine in neonatal piglets. Male neonatal piglets were fed with sow's milk or artificial milk formula. Every 8 h the latter received either vehicle or leptin (2 or 10 microg/kg body weight). The animals were either killed after 6 days of treatment and the small intestine sampled for histology and brush border enzyme activities or were tested for marker molecule (Na-fluorescein and BSA) absorption in vivo. Feeding milk formula slowed the maturation of small intestinal mucosa compared with feeding sow's milk. However, after leptin treatment the length of the small intestine was increased, and intestinal villi length, but not crypt size, was reduced compared with controls. The mitotic index was increased and the percentage of vacuolated enterocytes was reduced in the entire small intestine. Enterocyte brush border protease and lactase activities were reduced in the jejunum. Na-fluorescein marker molecule absorption did not change but that of BSA was reduced 3.8-fold. In conclusion, exogenous leptin administered in physiological doses reversed the maturation of the small intestinal mucosa to the range found in sow-reared piglets.

Aminopeptidases↗
PubMed2001

Enteral exposure to crude red kidney bean lectin induces maturation of the gut in suckling pigs.

The present investigation characterized the effect of red kidney bean lectin exposure on gut maturation and function in young piglets. Eleven suckling pigs were given by stomach tube a crude red kidney bean lectin preparation (containing about 25% lectin, 400 mg/kg BW) (lectin-treated pigs) at 10, 11, and 12 d of life, and an additional 16 pigs (control pigs) were given saline instead. On the next day, the intestinal absorptive capacity was determined in vivo, and on the 14th d of life the piglets were killed and organs and small intestine samples were collected for analyses and in vitro permeability experiments. The lectin-treated pigs showed an increase in stomach weights and mucosa thickness, whereas no weight effect was found for the small intestine, spleen, liver, or adrenals. Morphometric analyses of the small intestine in lectin-treated pigs showed a decrease in villus heights, an increase in crypt depths and crypt cell mitotic indices, and fewer vacuolated enterocytes per villus and reduced vacuole size. Lectin treatment also resulted in a decrease in the absorption of different-sized marker molecules after gavage feeding, a decrease in intestinal marker permeability, and a change in small intestinal disaccharidase activities, with increased maltase and sucrase activities. The size of the pancreatic acini was also greater in the lectin-treated pigs, but no increases in enzyme content or pancreatic weight could be determined. In addition, the blood plasma levels of cholecystokinin were higher in the lectin-treated than in the control pigs. The results indicate that exposure to crude red kidney bean lectin induces structural and functional maturation of the gut and pancreatic growth in young suckling piglets. This possibility of inducing gut maturation may lead to an improvement in the piglets' ability to adapt to weaning and to an increase in the growth and health of these animals.

Animals↗
PubMed2001

[Risk of hypertension after heart transplantation in the follow-up period].

From October 1988 to March 2000, 58 patients underwent orthotopic heart transplantation (HTX). Data of 220 heart recipients with the follow up > or = 3 months after HTX were analyzed using the average values of blood pressure measured with the sphigmo-manometer. 65% of patients were diagnosed with the hypertension (HA). 39.9% of those patients (NTA group) had the systolic blood pressure < or = 140 mmHg and diastolic blood pressure < or = 90 mmHg during pharmacotherapy. 60.1% of hypertensive patients (NTB group) had the systolic pressure > 140 mmHg and/or diastolic pressure > 90 mmHg despite pharmacotherapy. 35% of all patients had normal blood pressure after HTX (HNA group). Patients with hypertension were older and the end stage ischemic cardiomyopathy was more frequently indication for HTX. Significantly more females were in NTA group. We observed no influence of the daily dose of cyclosporine or other immunosuppressive drugs on HA. The average blood concentration of cyclosporine A and mycophenolate mofetil was similar in all groups. The calcium channel blockers and inhibitors of angiotensin converting enzyme were main tool of pharmacotherapy used. In NTA group calcium channels blockers were used more frequently. In NTB group there was a statistically significant higher blood level of creatinine. After HTX there is a high risk of HA, which: increases with age, with the ischemic cardiomyopathy as indication to HTX, is significantly higher in males, there is no correlation between HA and the dosage and blood level of cyclosporine, increases with kidney insufficiency. In monotherapy calcium channel blockers seem to be especially effective.

Adolescent↗
PubMed1999

Small intestinal and pancreatic microstructures are modified by an intraduodenal CCK-A receptor antagonist administration in neonatal calves.

The aim of the present study was to investigate the role of CCK on the upper gut and pancreas microstructure and on pancreatic juice secretion in neonatal calves assessed by a repetitive intraduodenal administration of FK480, a CCK-A receptor antagonist, during the first 6 days of life. The experiment was performed on 10 neonatal calves surgically fitted with a pancreatic accessory duct catheter and duodenal cannulas. Calves were sacrificed on day 7 for tissue sampling. Treatment with FK480 resulted in: reduction of preprandial pancreatic juice secretion at days 1-3, smaller size of pancreatic acini and number of cells per acinus, reduction in intestinal crypt depth (except in the duodenal bulb), numerous modifications of intestinal villi length and width, lower mitotic index of crypt cells, and increased number and size of enterocytes with 'empty vacuoles'. In conclusion, the blockade of CCK-A receptors during early life both reduced pancreatic exocrine secretion and induced complex changes in pancreatic microstructure. The influence of CCK on the upper gut microstructure in neonatal calves could be either direct via activation of CCK-A receptors located in the mucosa of the upper gut or indirect by modulation of the secretion of pancreatic juice.

Animals↗
PubMed1998

All that you can be: stereotyping of self and others in a military context.

The authors tested the shifting standards model (M. Biernat, M. Manis, & T. E. Nelson, 1991) as it applies to sex- and race-based stereotyping of self and others in the military. U. S. Army officers attending a leadership training course made judgments of their own and their groupmates' leadership competence at 3 time points over a 9-week period. We examined the effects of officer sex and race on both subjective (rating) and objective/common-rule (ranking/Q-sort) evaluations. Stereotyping generally increased with time, and in accordance with the shifting standards model, pro-male judgment bias was more evident in rankings than in ratings, particularly for White targets. Self-judgments were also affected by sex-based shifting standards, particularly in workgroups containing a single ("solo") woman. Differential standard use on the basis of race was less apparent, a finding attributed to the Army's explicit invocation against the use of differential race-based standards.

Adult↗
PubMed1998

The incidence of malignancy in heart transplant recipients.

OBJECTIVES AND METHODS: 219 heart transplant recipients with survival over 3 months were retro- and prospectively analysed for the incidence of primary neoplasms. Patients received immunosuppressive drugs (cyclosporine A, azathioprine, steroids) with a 4-5 days induction course of Rabbit Anti-Thymocyte Immunoglobulin (RATG) or monoclonal antibodies induction /OKT3/ in some cases. Anti-rejection treatment consisted of pulse doses of methyloprednisolon or RATG. RESULTS: 9 cases of malignancy (4.1%) with one case of pre-malignant liver condition (dysplasia gigantocellulare, 0.45%) were found (8M; 1F; age: 45-67 y.o., x57.7). Symptoms of neoplasms occurred 7-79 months (x31.4) postoperatively. Skin carcinomas: planoepitheliale, spinocellulare, soft tissue neoplasms/mesenchymal sarcoma, larynx Ca planoepitheliale, lung: adenocarcinoma and Ca microcellulare, kidney Ca clarocellulare and post transplant non-Hodgkin lymphoma were diagnosed. Chemo- and radiotherapy, surgery and reduction of immunosuppression did not change the outcome of malignancy in 6 pts.; (regression-1 pt was., remission-2 pts). Patients died 7-86 months after Htx (x41), 4-25 mos. (x12.5) after suffering from first symptoms and 0-10 months (x4.9) after pathology-based diagnosis of neoplasm. CONCLUSIONS: Heart transplant recipients have an increased risk of carcinogenesis. The incidence of malignancies in the studied group is similar or even lower than in other reports.

Adult↗
PubMed1997

Assessment of PTSD symptoms in a community exposed to serial murder.

This study examined the presence of PTSD symptoms across time in a community exposed to serial murder. One hundred eighty four subjects (48% response rate) responded to the initial survey while 64 and 30 subjects, respectively, participated in the 9- and 18-month follow-up studies. Results indicated widespread endorsement of PTSD symptoms following the murders. The most severe reactions were found among residents demographically similar to the victims. PTSD symptoms, while not transient, appeared to decrease over time with few subjects still reporting symptoms at 18 months. These data suggest that violent acts such as serial murder can have far reaching psychological consequences for the community and result in vicarious victimization.

Adult↗
PubMed1997

Perceptions of the media in a community exposed to serial murder.

This study examined resident perceptions of the media in a community exposed to serial murder. Residents were surveyed regarding the popularity, accuracy and trust of various information sources. One hundred eighty-four residents (48% response rate) responded to mailed questionnaires. Results indicated that traditional sources of news (television, radio, and newspapers) were the most popular sources of information. However, police press conferences were judged to be the most accurate and trustworthy. Residents viewed media reports on methods of reducing personal risk as beneficial and enhancing feelings of safety. However, details of mutilations and sensational reporting were judged to increase personal fears and led to widespread dissatisfaction with the media.

Adult↗
PubMed1997

Gender- and race-based standards of competence: lower minimum standards but higher ability standards for devalued groups.

Stereotypes may influence judgment via assimilation, such that individual group members are evaluated consistently with stereotypes, or via contrast, such that targets are displaced from the overall group expectation. Two models of judgment--the shifting standards model and status characteristics theory--provide some insight into predicting and interpreting these apparently contradictory effects. In 2 studies involving a simulated applicant-evaluation setting, we predicted and found that participants set lower minimum-competency standards, but higher ability standards, for female than for male and for Black than for White applicants. Thus, although it may be easier for low- than high-status group members to meet (low) standards, these same people must work harder to prove that their performance is ability based.

Female↗
PubMed1997

Simultaneous assimilation and contrast effects in judgments of self and others.

Judgments of self and referent others tend to be positively related, as evident in the false consensus effect, but others may also be contrasted from the self, as noted in the false uniqueness literature. In 3 studies that examined the domains of attitudes and traits, evidence of both assimilative and contrastive associations between self- and other-judgements were noted, depending on the form of judgment (objective vs. subjective) and the relevant judgment scale anchor (self vs. others). When self-judgments were made first, objective appraisals of reference groups were contrasted from subjective self-appraisals (after controlling for individual differences in participants' behavioral reports). When judgments of others were made first, objective self-ratings were contrasted from subjective other-judgments. Implications for the false consensus literature and the shifting standards model (M. Biernat, M. Manis, & T. E. Nelson, 1991) are discussed.

Adult↗
PubMed1996

Selective self-stereotyping.

In an examination of group members' responses to the threat of negative in-group characterizations, sorority/fraternity members were asked to rate themselves, their own sorority/fraternity, sororities/ fraternities in general, and students in general on attributes that were stereotypic of sororities/ fraternities. Results showed that individuals selectively self-stereotyped-they embraced positive stereotypes as highly descriptive of themselves and their closest in-groups but rejected negative stereotypes. They did not, however, deny that negative stereotypes were accurate or valid-they continued to accept them as typical of sororities/fraternities in general. This represents a protective, creative response to the threat posed by exposure to negative group attributes, in which self-stereotyping as a result of self-categorization is selective rather than complete.

Analysis of Variance↗
PubMed1994

Shifting standards and stereotype-based judgments.

Four studies tested a model of stereotype-based shifts in judgment standards developed by M. Biernat, M. Manis, and T. E. Nelson (1991). The model suggests that subjective judgments of target persons from different social groups may fail to reveal the stereotyped expectations of judges, because they invite the use of different evaluative standards; more "objective" or common rule indicators reduce such standard shifts. The stereotypes that men are more competent than women, women are more verbally able than men, Whites are more verbally able than Blacks, and Blacks are more athletic than Whites were successfully used to demonstrate the shifting standards phenomenon. Several individual-difference measures were also effective in predicting differential susceptibility to standard shifts, and direct evidence was provided that differing comparison standards account for substantial differences in target ratings.

Adolescent↗
PubMed1991

Sharing of home responsibilities between professionally employed women and their husbands.

A sample of 139 married couples with young children and with relatively equal status careers (wives were university professors or businesswomen) were interviewed about work and home life. Considerable, traditional inequity in the distribution of child-care tasks and chore responsibility was noted, but women were generally satisfied with their husbands' home involvement. In the academic sample, the longer hours each spouse worked, the more child care the other performed; in the business sample, child-care involvement was largely determined by the husband's work hours, income, and education. Overall, women were more self-critical than were men about their performance in home roles, and women's role performance was rated more highly by husbands than by themselves. Women professionals' continued use of traditional sex role standards and the importance of attending to both partners' perspectives in studies of married life are discussed.

Adaptation, Psychological↗
PubMed1991

Comparison and expectancy processes in human judgment.

This work explored a judgment model proposed by Manis and Paskewitz (1984a). The model suggests that prior experience with the members of a given category affects the assessment of other category members in 2 ways: (a) by providing a basis for comparison and (b) by leading the judge to expect that new exemplars will resemble those previously encountered. In 4 experiments, respondents judged the height of different people on the basis of full-length photographs. The height of the models in an induction series constituted the main independent variable. The effects of contrasting inductions (e.g., short vs. tall women) affected the judges' subsequent assessments in a test series. Both comparison and expectancy processes played a significant role, sometimes opposing one another and sometimes acting in parallel (i.e., supporting one another).

Female↗
PubMed1991

Gender stereotypes and the relationship between masculinity and femininity: a developmental analysis.

This study investigated developmental shifts in (a) the use of global gender stereotypes (base rates) and individuating gender-relevant information when making social judgments and (b) the perceived association between masculinity and femininity. Interviews/surveys of kindergartners, 3rd graders, 7th graders, 10th graders, and college students (N = 491) were conducted, in which Ss were presented with descriptions of boys or girls with stereotypical or counterstereotypical attributes and asked to judge other characteristics these boys or girls might have. The data indicated that (a) reliance on gender labels as judgment cues remains stable developmentally, (b) use of individuating information (particularly masculine individuating information) increases with age, and (c) the relationship between masculinity and femininity becomes increasingly negative with age, suggesting that gender may initially be viewed in dualistic terms but later as a unidimensional construct.

Adolescent↗
PubMed1991

Prostaglandin E2 inhibits secretagogue-induced enzyme secretion from rat pancreatic acini.

Prostaglandins of the E type may have a potential role in pancreatic physiology and pathophysiology. Because prostaglandins of the E type inhibit HCl secretion in parietal cells via a specific receptor by inhibition of adenylylcyclase, we studied whether a similar mechanism exists in the exocrine pancreas. Isolated rat pancreatic acini were incubated with various concentrations of secretagogues, such as cholecystokinin-octapeptide (CCK-8), bombesin, carbachol, and vasoactive intestinal peptide (VIP), in the absence or presence of prostaglandin E2 (PGE2), and amylase secretion was measured. For receptor binding studies, acini and pancreatic membranes were incubated with [3H]PGE2 and either unlabeled PGE2 or other types of prostaglandins. PGE2 (10(-13) to 10(-5) M) did not inhibit basal amylase secretion. However, CCK-8-stimulated secretion was significantly inhibited. Stimulation of secretion by bombesin, carbachol, VIP, and secretin was also inhibited by PGE2, but not as pronounced as CCK-8-stimulated secretion. The formation of inositol 1,4,5-trisphosphate induced by CCK-8 was markedly inhibited by simultaneous incubation with PGE2. Furthermore, PGE2 slightly but significantly reduced the CCK-8-induced efflux of 45Ca2+ from prelabeled acini. Intact acini and a membrane fraction bound [3H]PGE2 and this function could be equally competed by either unlabeled PGE2 or PGE1 in contrast to less-related prostaglandins such as PGF2 alpha, PGD2, and prostacyclin. We conclude that prostaglandins of the E type inhibit pancreatic enzyme secretion stimulated by various secretagogues. This function is mediated via specific receptors for PGE. With regard to CCK-8-stimulated secretion this function may be mediated by an inhibition of formation of inositol 1,4,5-trisphosphate.

Amylases↗