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Biomedical subjects

A Bremer

Publications and source records attributed to A Bremer.

52 records · Page 3Linked to original sources
PubMedDate not supplied

Native talin is a dumbbell-shaped homodimer when it interacts with actin.

Electron microscopy of glycerol-sprayed and rotary metal-shadowed talin from human platelets reveals a dumbbell-shaped molecule with an average length of approximately 51 nm. Analytical ultracentrifugation of native talin yields a single molecular species with an apparent molecular mass of 412 (+/- 28.6) kDa and a sedimentation coefficient of S20w = 11.2. Chemical cross-linking with glutaraldehyde (GA) and corresponding SDS-PAGE analysis show that the monomer band of talin can be quantitatively converted to a dimer band at GA concentrations > or = 0.45%, indicating that there is no significant amount of monomer present in solution. These structural and biophysical data are compatible with native talin being an antiparallel homodimer. Length measurements and viscometric and fluorescent assays of actin filaments polymerized in the presence of native talin and of covalently cross-linked talin dimers all yield similar effects: namely, increased nucleation and polymerization rates and an overall reduction of actin filament length. Hence, we conclude that talin in its native biological state is a dimer when promoting nucleation of actin filaments.

Actins↗
PubMedDate not supplied

Experimental regional cerebral ischemia in the middle cerebral artery territory in primates. Part 2: Effects on brain water and electrolytes in the early phase of MCA stroke.

Acute regional cerebral ischemia was produced in the middle cerebral artery (MCA) territory in monkeys (Macaca mulatta) by selective embolization of the internal carotid (ICA) bifurcation with minimum surgical intervention in the neck under sedated conditions. Two of five hours after embolization, brain water (measurement of dry weight) and tissue concentration of sodium and potassium were determined in the tissues of the sylvian cortex, putamen and subcortical white matter in the affected MCA territory. As early as three hours, initial increase in brain water was detected in the samples of the putament without noticeable change in tissue electrolytes in two of three animals. Gross ischemic swelling of the gray matter, in both the sylvian cortex and putamen, became obvious in six of eight animals after four to five hours. This swollen gray matter showed marked increase in brain water (up to 36% swelling), increase in tissue sodium (up to 100% of the control value), and decrease in tissue potassium (down to 55%). On the other hand, edema in the white matter, if present at all, was minimal without detectable change in tissue electrolytes and was always accompanied by much greater ( greater than two to seven times) edema in the gray matter. Thus, the gray matter edema, in both the deep subcortical structures and the cortex, appeared to play the major role in the development of hemispheric swelling of the brain which may begin within hours of the onset of the MCA stroke in monkeys. Microscopically, the swollen gray matter which showed more than 10% swelling with a definite shift of tissue sodium and potassium content appeared to be dead tissue. However, early edema in the gray matter which showed less than 10% swelling without detectable change in electrolytes might be caused by simple diffusion of water through the dysfunctional capillary wall or cell membrane with or without a permeability gradient between the intravascular cerebrospinal fluid and cerebral tissue compartment and might possibly be reversible.

Animals↗
PubMedDate not supplied

[Biliary hemorrhage due to a false aneurysm of the hepatic and gastroduodenal arteries (author's transl)].

Two cases of biliary hemorrhage due to false aneurysms are presented, one on an abnormal hepatic artery, the other on the gastroduodenal artery. Half of the cases of biliary hemorrhage have an intrahepatic etiology. Extrahepatic cases are equally divided between the main biliary duct and the gallbladder. Among the diagnostic investigations most authors agree on the choice of selective arteriography of the coeliac trunk. Controle of intrahepatic biliary bleeding can be obtained by partial hepatectomy or by ligation of the hepatic artery which is well tolerated. Treatment of extrahepatic bleeding is more diverse and takes into account both anatomical and surgical possibilities.

Aneurysm↗
PubMedDate not supplied

[About 35 cases of perforated colon diverticulitis (author's transl)].

Thirty-five cases of perforated colon diverticulitis were treated by us between 1960 and 1977. An overall mortality of 34% reveals the seriousness of this disease. Perforation in open peritoneum doubles the mortality and morbidity rate of covered perforations and of secondary fistulisation. The surgical operations used--immediate resection or colostomy and a drainage--were imposed by the status of the patient and the local state of the lesion. The resection of the pathological colon segment, when feasable, caused no death in this series although a mortality of 48% was noted for multiple procedures. The diagnostical and surgical difficulties associated to profound biological and hemodynamic alterations in these old patients, justifies the multiple stage surgery in a large number of cases. Resection of the perforated segment remains the treatment of choice.

Adult↗
PubMedDate not supplied

[Long-term results of the surgical treatment of hiatal hernia using the Boerema technic].

The authors analyse the results of the surgical treatment of "symptomatic hiatus hernia" by the Boerema anterior gastropexy, in 69 patients. As compared to other techniques, the observed mortality and morbidity rates are similar. The postoperative delay is greater than 2 years in 95% of the patients and 83% of them are satisfied with the treatment. Better results are actually obtained with other techniques. Nevertheless, anterior gastropexy which remains the easiest and fastest technique, may still be used in elderly or high risk patients. The Nissen fundoplication is recommended for the majority of the patients suffering from "symptomatic hiatus hernia", especially when ulcerative reflux esophagitis is present.

Adult↗