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Biomedical subjects

A Beck

Publications and source records attributed to A Beck.

At least 289 records · Page 16Linked to original sources
PubMed1987

A comparison of the teaching effectiveness of the didactic lecture and the problem-oriented small group session: a prospective study.

A prospective study was designed to assess the teaching effectiveness of active learning in problem-oriented small group sessions (POSGS) compared with passive learning in didactic lectures (DL). Third-year medical students participated in a POSGS on breast disease and a standardized DL on thyroid disease (N = 23) or participated in a POSGS on thyroid disease and a DL on breast disease (N = 19). Students were tested with a multiple-choice examination (MCQ) and a highly structured oral examination (OE) administered by faculty members blinded about student group. Results of a between-within analysis of variance performed separately for breast and thyroid disease yielded significant group differences because of instructional method for thyroid disease (p = 0.003) and approached significance for breast disease (p = 0.095). Although no significant interactions were detected with percentage scores, a significant interaction between group membership and test type was noted for thyroid disease when the percentage scores were transformed to Z scores. We conclude that regardless of topic or testing method, students in POSGS tended to perform better than students in a DL and that the POSGS offers significant advantages over the DL in teaching surgery to third-year medical students.

Breast Diseases↗
PubMed1987

Twins: prophylactic hospitalization and ward rest at early gestational age.

One hundred eighty-nine twin pregnancies were delivered at Wilford Hall United States Air Force Medical Center from July 1977 through December 1985. Among these, 57 were referred from distant bases and were excluded from further analysis. The remaining 132 pregnancies from our local population make up the study group. Sixty-seven women (51%) followed our advice to be hospitalized at or before 28 weeks' gestation for prophylactic ward rest. The remaining 65 women (49%) were not hospitalized until after 28 weeks' gestational age or until a pregnancy complication or labor occurred. Only three of 134 infants (2%) whose mothers were admitted died, versus 11 of 130 infants (8.5%) whose mothers were not admitted (P less than .03). The results suggest that prophylactic ward rest, implemented at or before 28 weeks' gestational age, may reduce perinatal mortality in this condition.

Bed Rest↗
PubMed1986

Parental reactions to the onset of adolescence.

This paper documents the common changes associated with the onset of puberty and examines parents' reactions to these changes. Nine hundred questionnaires were sent to the parents of sixth and seventh graders (11-13 years old) in four communities. The questionnaire requested information on the perception of recent behavioral changes and the parents' emotional responses to them. Four hundred parents responded. Parents reported significant changes, both positive and negative, in their children in the year prior to the study. Reported changes were not significantly related to community locations, demographic or education variables, and, with one exception, to the sex of the child. First-born children were perceived more negatively and generated more negative feelings in parents. Younger parents (less than or equal to 38 years of age) perceived more negative changes and experienced more negative and anxious feelings toward their children than did older parents (greater than or equal to 39 years). These findings suggest that a primary cause of stress for parents with children in this age group may be a lack of knowledge about the developmental process. Physicians may be able to reduce the stress by providing anticipatory guidance to parents about the physical growth and psychologic aspects of early adolescence.

Adolescent↗
PubMed1986

[Analysis of indirect maternal mortality cases].

Among 145 cases of maternal deaths from the period 1975 to 1983, whose data had been collected in a nationwide survey, 30 cases (21%) were classified as associated causes of maternal deaths. 10 deaths (33%) occurred at the birth of the child, 11 (37%) within 6 weeks after delivery, 4 (13%) within the first trimester and 5 (17%) within the second trimester. The disease that was in causal relation to the complication leading to death was known in 16 cases (53%), unknown in 13 cases (43%); in one case information is missing. In 11 cases (37%) it was a cardiac disease, in 6 cases (20%) a cerebrovascular disease and in 4 cases (13%) a disease of the lung. All other diseases leading to the death of the mother were rare diseases. It can be concluded that more emphasis should be given to the diagnosis of cardiovascular diseases during pregnancy and further to the clarification of uncertain conditions in the postnatal period. In case of a disease with high maternal risk, sterilisation should be considered.

Abortion, Spontaneous↗
PubMed1986

Isolation and nucleotide sequence analysis of a cloned cDNA encoding the beta-subunit of bovine follicle-stimulating hormone.

Two different cDNAs containing sequences coding for the beta-subunit of bovine follicle stimulating hormone (FSH-beta) have been isolated from a phage lambda gt11 bovine pituitary cDNA library. The complete nucleotide sequence of both clones was determined, and the combined sequence represents most of FSH-beta mRNA. The combined sequence contains 46 nucleotides of 5'-untranslated sequence followed by 387 nucleotides of coding sequence. The coding sequence predicts a 19-amino-acid amino-terminal precursor segment followed by the 110-amino-acid sequence of mature bovine FSH-beta. The cDNA sequence demonstrates the presence of a long 3'-untranslated region containing 1295 bases followed by a segment representing the poly(A) portion of the mRNA. Thus, the combined sequence of the cDNAs suggests a minimal size of 1.7 kb for FSH-beta mRNA. Analysis of FSH-beta sequences present in bovine pituitary mRNA demonstrated the presence of an mRNA with a size of about 2.0 kb. This apparent discrepancy is probably due to the presence of a several-hundred nucleotide tract of poly(A) at the 3' terminus of the mRNA. Comparison of the amino acid sequence predicted from the cDNA with the known amino acid sequence of the beta-subunit of FSH from several different species demonstrates that the protein has been highly conserved.

Amino Acid Sequence↗
PubMed1986

[Sonographic diagnosis of the gastrointestinal tract].

Ultrasound examination is an established screening procedure for illdefined abdominal complaints and is complementary to the abdominal plain film. The bull's eye phenomenon due to bowel wall thickening is the characteristic feature of bowel pathology. Ultrasound is the method of proof for hypertrophic pyloric stenosis, imperforate anus or ascites. Findings of edematous (intussusception), inflammatory (Crohn disease) and neoplastic stomach or bowel disease require confirmation by radiology or endoscopy. Ultrasound of the gastrointestinal tract allows the selection of further diagnostic procedures and thus accelerates the diagnostic work-up.

Anus, Imperforate↗
PubMed1986

[Experiences with alloplasty repair of defects of the skull calotte with modern artificial materials].

There are controversial views on alloplastic repair of skull cap defects. This has prompted the authors to report their own experience from indirect cranioalloplasty, using polymethylmethacrylates (PMMA). Seventy-two implantations were performed on patients, within 13 years, most of them for traumatic defects. Immediate repair was carried out in four cases, following neurosurgical interventions. Two implants had to be removed for cosmetic reasons and four for infections. Hence, the rate of complications amounted to six per cent. The brain-dura region was improved, accompanied by positive effects on seizure problems. Cosmetic results were good to very good in 54 patients. Ten patients could move from part-time to full-time employment, following plastic repair. Benefits and setbacks of the method are discussed.

Adolescent↗
PubMed1985

Chlamydial endocervical infections and cytologic findings in sexually active female adolescents.

The association of infection with Chlamydia trachomatis and cytologic changes on Papanicolaou smear was examined in 148 sexually active postmenarchial++ female subjects, aged 13 to 21 years (mean = 17.2) attending a teen clinic. Endocervical samples for micro-organisms (C. trachomatis and Neisseria gonorrhoeae) and a cervical sample for cytologic examination were taken. A detailed evaluation of the cytologic results was made independently of the C. trachomatis status. In 23 (15.5%) subjects tests for isolation of C. trachomatis were positive. Inflammatory changes in epithelial cells, nuclear changes in metaplastic cells, and lymphocytes in the inflammatory exudate were associated with C. trachomatis isolation but suspected "chlamydial inclusions" and cytoplasmic vacuoles in metaplastic cells were not. The results reported here do not support the use of cervical cytologic examination as a definitive diagnostic test for presence of an endocervical chlamydial infection. However, it may be possible to use the cytologic pattern described here to identify a population with a high prevalence of C. trachomatis.

Adolescent↗
PubMed1985

Restriction endonuclease digest patterns of chromosomal DNA from nitrate-negative Campylobacter jejuni-like organisms.

High molecular weight chromosomal DNA was isolated from ten nitrate-negative campylobacters of human origin (gastric biopsies and faecal specimens). The DNA was digested with various restriction endonucleases and the patterns obtained were compared with those of Campylobacter coli, C. fetus subsp. fetus, C. jejuni and C. laridis reference strains. Electrophoresis of Hae III digests of DNA in 0.5% agarose gave excellent patterns which comprised at least 25 well-resolved bands with fragment sizes between about 4 and 40Kb. There were distinct differences between strains from different geographical locations. The six gastric strains from West Germany formed a relatively homogeneous group with respect to their band patterns (type I and II), whereas the U.K. gastric isolate had a slightly different pattern (type III) as did the three Australian faecal isolates (types IV, V and VI). No plasmids were detected in these nitrate-negative campylobacters and differences in DNA digest patterns between strains and representatives of allied species were attributed to variations in the distributions of Hae III recognition sequences within the genome. The patterns provided further evidence that the strains were atypical C. jejuni.

Campylobacter fetus↗
PubMed1985

Studies on the fibrinolytic activity of the human female genital tract.

The success of a fibrin glue depends on the correct admixture of fibrinogen, thrombin, and the proteinase inhibitor aprotinin. Using a modification of Astrups method we measured the fibrinolytic activity of surgical specimens of human fallopian tube and uterus. Increasing concentrations of aprotinin were added until there was complete inhibition of fibrinolysis. The fallopian tube and the uterus had higher intrinsic fibrinolytic activity than peripheral nerve tissue. At concentrations of between 10 and 20 KIU of aprotinin, fibrinolysis was blocked in all tissues studied.

Aprotinin↗
PubMed1985

Microbiology of the lower genital tract in postmenarchal adolescent girls: differences by sexual activity, contraception, and presence of nonspecific vaginitis.

The prevalence of selected microorganisms in the lower genital tract in postmenarchal adolescent girls was assessed, including vaginal Gardnerella vaginalis, group B streptococcus, lactobacillus, Mycoplasma species, Ureaplasma urealyticum, Staphylococcus aureus, and yeast, and endocervical Mycoplasma species, U. urealyticum, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis. Specific attention was focused on important sexually transmitted disease organisms, and differences in isolations by age, sexual activity, ethnicity, contraception, and the diagnosis of nonspecific vaginitis were measured. Sexually active subjects had a mean of 6.05 organisms (SD = 3.16), compared with 3.12 organisms (SD = 3.92) in non-sexually active subjects (P = 0.001). Sexually active subjects had significantly more vaginal G. vaginalis, lactobacilli, Mycoplasma species, and U. urealyticum, as well as endocervical Mycoplasma species and U. urealyticum, compared with non-sexually active subjects; C. trachomatis, N. gonorrhoea, and T. vaginalis were isolated exclusively from the sexually active group. Significant differences in isolation rates by ethnicity were found in vaginal Mycoplasma species and U. urealyticum, and endocervical Mycoplasma species, U. urealyticum, C. trachomatis, N. gonorrhoeae, and T. vaginalis. In general, organisms were isolated from blacks most frequently; N. gonorrhoea was isolated from blacks exclusively. Differences were found in microbiologic isolations by the presence or absence of nonspecific vaginitis. Vaginal G. vaginalis and Mycoplasma species and endocervical Mycoplasma species and U. urealyticum were found significantly more often in isolates from the group with nonspecific vaginitis. It is important to define the microbial flora of the lower genital tract in adolescent girls in order to understand its role in the pathogenesis of acute salpingitis.

Adolescent↗
PubMed1985

Angiotensin-induced hypertension in conscious dogs: biochemical parameters and baroreceptor reflex.

The effects of a continuous iv infusion (osmotic minipumps) of angiotensin II (80 ng . kg-1 . min-1) and isoprenaline (10 ng . kg-1 . min-1) lasting 28 days were studied in six normotensive, conscious dogs. The parameters measured were systolic and diastolic blood pressure, heart rate, levels of angiotensin II, renin activity, aldosterone and antidiuretic hormone in plasma, baroreceptor reflex sensitivity and body weight. The treatment resulted in an approximately sevenfold increase in plasma angiotensin II level from 62.9 +/- 24.5 pg . ml-1 to 455.3 +/- 95.6 pg . ml-1. Systolic and diastolic blood pressure, measured for the first time 2 days after implanting the minipumps, were markedly increased throughout the infusion period (pretreatment value: 123.8 +/- 5.3/68.3 +/- 3.8 mmHg; after 2 days: 159.8 +/- 12.0/100.5 +/- 9.8 mmHg; after 28 days: 159.8 +/- 7.1/98.3 +/- 6.4 mmHg, whereas the heart rate remained unchanged due to the combined effects of angiotensin II and the concomitantly given isoprenaline. A high correlation was found between angiotensin II level in plasma and mean arterial blood pressure (r = 0.846; p less than 0.001). Furthermore, plasma renin activity was markedly suppressed by the treatment, and aldosterone levels rose. Plasma antidiuretic hormone levels were found to be unchanged at the chosen sampling time. A decrease in baroreceptor reflex sensitivity accompanied the development of the hypertensive state. There was also a loss of body weight during the infusion of angiotensin II and isoprenaline. The data provide evidence for the usefulness of the presented experimental protocol as an alternative model of arterial hypertension in chronically instrumented, conscious dogs.

Aldosterone↗
PubMed1985

[Improvement of arteriography technics by new thin catheters].

New, small, polyurethane French 4 and French 5 sized catheters with a commensurately large lumen are described. In combination with DSA they allow low doses of contrast media in renal insufficiency and facilitate selective and superselective manipulations. The high flow specification also permits use in "conventional" angiography.

Angiography↗
PubMed1985

Characterization of vasodilators by comparison of their effects on blood pressure, counterregulation and myocardial oxygen demand in conscious normotensive dogs.

Vasodilators were characterized on the basis of their first-dose effect on systolic and diastolic blood pressure, heart rate, on the product of heart rate and systolic blood pressure and on plasma renin activity (PRA) in conscious normotensive dogs. The compounds were given orally to the animals and the effects were studied over a period of 4 h. The arterial vasodilators (propyldazine, dihydralazine and labetalol) caused a marked reduction of systolic and diastolic blood pressure with excessive stimulation of the sympathetic nervous system, leading to an increase in myocardial oxygen demand. The blood pressure effect of urapidil and prazosin resembled more the pattern seen with typical venous dilators (molsidomine and nitrates) and was not accompanied by significant increases in heart rate and in PRA. Hence, the magnitude of diastolic blood pressure reduction seems to be an essential determinant of reflex counterregulation. The results prove that some few parameters can give information about the overall pattern of hemodynamic effects of vasodilators.

Animals↗