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Biomedical subjects

G Arnold

Publications and source records attributed to G Arnold.

259 records · Page 15Linked to original sources
PubMedDate not supplied

Myocardial oxygen consumption and regulation of coronary blood flow during stepped relief of the left ventricle.

In 25 calves an atrio-ventriculo-aortic bypass was performed and the metabolism and the regulation of coronary blood flow during stepped assistance of the left ventricle was studied. With mean aortic blood pressure kept constant stepped decrease in left ventricular pressure from 120 to 0 mmHg diminished myocardial oxygen consumption from 7.7 to 1.9 ml O2/min X 100 g. Increasing right ventricular pressure by banding the pulmonary artery with left ventricular pressure and mean aortic pressure kept constant the oxygen uptake of the left ventricle increased about 20.7 +/- 32.% when measured by Fick's principle but remained unchanged when calculated from hemodynamic parameters of the left ventricle (-1.5 +/- 3.5%). At constant coronary perfusion pressure coronary blood flow decreased when left ventricular pressure was reduced from 120 to 100 mmHg. Further decrease in left ventricular pressure to 0 mmHg showed no effect on coronary blood flow. Increasing heart rate from 152 +/- 9 to 208 +/- 8 b.p.m. enhanced myocardial oxygen uptake of the assisted heart about 59.0 +/- 11.4% while resistance to flow decreased about 40.4 +/- 2.8%. These results show that the metabolic regulation of coronary blood flow is still acting even in the assisted left heart.

Animals↗
PubMedDate not supplied

Identification and developmental profiles of hexamerins in antenna and hemolymph of the honeybee, Apis mellifera.

Four distinct hexamerin subunits (referred to as "hexamerins" in the following text) have been identified in the developing honeybee, Apis mellifera, by N-terminal protein sequencing. Hexamerins are abundant in the hemolymph of late larval and early pupal stages, and gradually decline during metamorphosis and adult development. Three hexamerins in the 70 kDa range have been found (Hex70a, Hex70b, Hex70c). In worker and drone, Hex70a is the only hexamerin present in large amount in later adult stages. Hex70b and c exhibit a similar developmental profile, disappearing in the drone just before adult emergence, and in the worker just after. Hex70b or Hex70c are still detectable in the adult queen. Hex80/110 likely exist in at least 3 different subunits, 1 of 110 kDa, and 2 of around 80 kDa, which all share a common N-terminus. They disappear during metamorphosis earlier than Hex70b and c. All these hexamerins have been found also in the antenna, suggesting their utilization in building up of antennal cuticle structures.

Amino Acid Sequence↗
PubMedDate not supplied

Relaxin induces vascular endothelial growth factor expression and angiogenesis selectively at wound sites.

Relaxin is a reproductive hormone that has historically been characterized as being responsible for pubic ligament loosening and cervical ripening. Recently, relaxin has been associated with neovascularization of the endometrial lining of the uterus, potentially via specific induction of vascular endothelial growth factor. Previously conducted clinical studies using partially purified porcine relaxin have described relaxin's ability to stimulate the healing of ischemic wounds, suggesting that relaxin may also have angiogenic effects at sites of ischemic wound healing. In the present study, relaxin's angiogenic effects in the context of wound repair were tested in rodent models of angiogenesis and wound healing. Relaxin showed an ability to stimulate new blood vessel formation, particularly at ischemic wound sites, and to induce both vascular endothelial growth factor and basic fibroblast growth factor specifically in cells, presumably including macrophages, collected from wound sites. Resident macrophages collected from nonwound sites, such as the lung, did not show altered expression of these cytokines following relaxin administration. Because angiogenic wound cells are frequently macrophages, THP-1 cells, a cell line of monocyte lineage that binds relaxin specifically, were tested for and shown to induce vascular endothelial growth factor and basic fibroblast growth factor in response to relaxin. In conclusion, relaxin may be useful in the treatment of ischemic wounds by stimulating angiogenesis via the induction of vascular endothelial growth factor and basic fibroblast growth factor in wound macrophages.

Animals↗
PubMedDate not supplied

Subtyping of coagulation factor XIIIA.

An extended polymorphism of the coagulation factor XIIIA can routinely be detected in human plasma samples and white cell lysates by isoelectric focusing in polyacrylamide gels containing 3 M urea in the pH range 5-8. Analyses of 184 families with 513 children confirmed the formal model proposed by Suzuki et al. [Am J Hum Genet 1988;43:170-174]. Four common alleles, F XIIIA*1A, 1B, 2A, 2B, at an autosomal locus control the expression of ten phenotypes. On the basis of the population sample from southwest Germany the frequencies of the common alleles F XIIIA*1A, 1B, 2A, 2B were calculated as 0.175, 0.609, 0.011, and 0.205, respectively.

Child↗
PubMedDate not supplied

Coagulation factor XIIIA subtypes in Brazilian Indians.

A total of 340 individuals living in seven localities of two Brazilian Indian groups (Macushi and Icana River Indians) were studied with respect to coagulation factor XIIIA subtypes. No inter- or intra-tribal differences were observed. The most striking finding was that FXIII*1A, an allele which is fairly common among Asiatic Mongoloids like the Japanese (27%), was nearly absent in these Indians.

Alleles↗
PubMedDate not supplied

Cytology of ascitic fluid in a patient with metastasizing malignant Brenner tumor of the ovary. A case report.

BACKGROUND: Transitional cell ("Brenner") tumors represent about 2% of all ovarian neoplasms. Brenner tumors are almost always benign. Malignant Brenner tumors of the ovary resemble urothelial carcinomas and are extremely rare. CASE: A 77-year-old, white female presented with malignant Brenner tumor in both ovaries as well as lung and abdominal metastases. The cytology of the ascitic fluid revealed many activated mesothelial cells and three-dimensional cell clusters arranged in a papillary pattern. The round to oval nuclei displayed mild anisokaryosis and hyperchromasia but had a quite evenly dispersed opaque or finely granular nucleoplasm. Enfoldings of the nuclear membrane gave them the appearance of so-called coffee bean nuclei. The cytoplasm stained light bluish. CONCLUSION: Knowledge of the cytologic features of ascitic fluid might allow a preoperative diagnosis of malignant, or at least proliferating, ovarian Brenner tumor.

Abdominal Neoplasms↗