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Biomedical subjects

K E Schroeder

Publications and source records attributed to K E Schroeder.

7 recordsLinked to original sources
PubMed2000

Personality type and neural circulatory control.

Psychosocial factors, including type A personality, anger, hostility, and anxiety, have been implicated in the pathogenesis of cardiovascular disease. Abnormal sympathetic responses to stress may help explain the link between certain behavior patterns and cardiovascular disease. We tested the hypothesis that in normal humans, type A personality characteristics are associated with exaggerated heart rate, pressor, and sympathetic nerve responses to mental and physical stress. We measured heart rate, blood pressure, and muscle sympathetic nerve activity (obtained with direct intraneural recordings) at rest and during stress in 45 healthy subjects (19 men and 26 women, age 29.2+/-8.7 years) who had no chronic diseases and were taking no medications. Subjects were divided into tertiles based on type A scores. There were no significant differences in sympathetic or hemodynamic reactivity among the 3 different intensity levels of type A characteristics. Baseline measures and responses to stress tests were similar across the 3 groups. Sympathetic and hemodynamic changes during stress tests were also similar in subject groups stratified according to anger scale and cynicism scale. Sympathetic nerve and hemodynamic measurements at rest and during stress were not different in normal subjects with type A characteristics. Abnormalities in sympathetic or cardiovascular reactivity are unlikely to be implicated in any excess of cardiovascular disease in people with type A personality characteristics.

Adult↗
PubMed1999

Spatially regulated translation in embryos: asymmetric expression of maternal Wnt-11 along the dorsal-ventral axis in Xenopus.

Transition from symmetry to asymmetry is a central theme in cell and developmental biology. In Xenopus embryos, dorsal-ventral asymmetry is initiated by a microtubule-dependent cytoplasmic rotation during the first cell cycle after fertilization. Here we show that the cytoplasmic rotation initiates differential cytoplasmic polyadenylation of maternal Xwnt-11 RNA, encoding a member of the Wnt family of cell-cell signaling factors. Translational regulation of Xwnt-11 mRNA along the dorsal-ventral axis results in asymmetric accumulation of Xwnt-11 protein. These results demonstrate spatially regulated translation of a maternal cell-signaling factor along the vertebrate dorsal-ventral axis and represent a novel mechanism for Wnt gene regulation. Spatial regulation of maternal RNA translation, which has been established in invertebrates, appears to be an evolutionarily conserved mechanism in the generation of intracellular asymmetry and the consequential formation of the multicellular body pattern.

Animals↗
PubMed1996

Xenopus poly (A) binding protein maternal RNA is localized during oogenesis and associated with large complexes in blastula.

Maternal mRNAs are synthesized during oogenesis and often stored for use during early embryogenesis, before the onset of zygotic transcription. The temporal and spatial regulation of maternal RNAs is likely to be crucial mechanism for the establishment of the body pattern. In the course of a study that identified a Xenopus maternal mRNA that is translationally regulated along the dorsoventral axis, several RNAs were found to behave anomalously in polysomal analysis and are further characterized here. As controls for polysome analysis, elF4E RNA and D7.1 RNA were equally translated in both dorsal and ventral cells, whereas the cell-cell signaling factor noggin RNA was not translated in either cell type. Maternal RNAs encoding poly (A) binding protein (PABP), Vg1 and Xcat-2 were associated with large complexes that, in contrast to polysomes, were not dissociated in magnesium-free buffer. Vg1 and Xcat-2 maternal mRNAs have been shown to be localized during oogenesis to the vegetal hemisphere of the oocyte [Rebagliati et al., 1985; Mosquera et al., 1993]. In situ hybridization analysis indicated that PABP RNA was also localized during oogenesis, to the animal hemisphere in stage VI oocytes. This suggests that association of maternal mRNAs with large EDTA-insensitive mRNP complexes is correlated with intracellular localization, but the specific localization within the oocyte is dependent upon the RNA species.

Animals↗
PubMed1980

Premature closure of the triradiate cartilage. Report of a case.

A case of early closure of the triradiate cartilage, probably secondary to neonatal septic arthritis of the right hip, is reported. Tomograms of the hip showed the triradiate cartilage closed posteriorly, with the anterior portion still open. These findings were confirmed at operation. An arthrogram and a CT scan of the right hip showed subluxation of the femoral head. This unique complication, after an episode of septic arthritis of the hip, has not before been reported in the literature.

Arthritis, Infectious↗
PubMed1979

Bilateral sacroilac dislocations in an adolescent. A case report.

This is a case report of a 15-year-old female who sustained bilateral closed sacroiliac dislocations. She was successfully treated with bilateral skeletal traction and manual closed reduction. The sacroiliac joints redislocated partially despite further traction. Reduction by traction and pelvic sling was then recovered and further displacement was prevented. She regained full range of motion of her hips. This is an uncommon injury produced only by severe trauma.

Adolescent↗
PubMedDate not supplied

The use of intravenous pentamidine as prophylaxis against Pneumocystis carinii pneumonia in patients with HIV infection.

The purpose of this study is to report on the use of monthly intravenous pentamidine as prophylaxis against Pneumocystis carinii pneumonia (PCP) within a central London HIV unit. A retrospective case note analysis of HIV-seropositive individuals using intravenous pentamidine as PCP prophylaxis was carried out. Aspects examined included reasons for using the regimen, compliance, adverse reactions and episodes of PCP. Eight patients were studied. There was no prophylaxis failure in 5 patients. Three patients developed PCP whilst on the regimen, although their compliance was poor. In patients who are intolerant of established prophylaxis regimens, intravenous pentamidine may be a useful alternative. It is well tolerated, although compliance is the main problem. Further prospective studies are indicated to assess its efficacy.

AIDS-Related Opportunistic Infections↗