PubMed Health⌕ Search

Biomedical subjects

B Hofmann

Publications and source records attributed to B Hofmann.

At least 163 records · Page 9Linked to original sources
PubMed1984

[Possible regulatory importance of cellular sulfhydryl groups and reduction metabolic pathways for the activation of human blood platelets].

The activation of the blood platelets is the prerequisite for their participation in physiological and pathological intravasal processes. An aimed influence on the distinct functions of the blood platelets presumes an exact knowledge about course and regulation of the activation of the platelets. Investigations on glucose-6-phosphate-dehydrogenase-deficient platelets and on the effect of glutathione-oxidizing substances on normal platelets showed references to a regulatory significance of the cellular thiol/disulphide state in the process of activation. In this case particularly the arachidonic acid balance and the SH/SS-state of platelet proteins seem to be in close connection with reductive ways of metabolism.

Arachidonic Acids↗
PubMed1983

Diamide mediated deaggregation of activated blood platelets is not caused by changes in adenine nucleotide pattern.

Studies on the effect of diamide (azodicarboxyl-bis-dimethylamide), a glutathione oxidizing agent, on platelet functions revealed an initial acceleration of aggregation followed by a pronounced deaggregation. The whole pattern of adenine nucleotides was followed up during both, arachidonic acid and arachidonic acid + diamide induced aggregation to prove whether the diamide mediated deaggregation is caused by changes in one of the parameters of the energy metabolism, i. e. ATP level, adenylate energy charge or ATP/ADP ratio.

Adenine Nucleotides↗
PubMed1983

Evidence for glutathione-S-transferase activity in human blood platelets.

Data will be presented pointing to the presence of glutathione-S-transferase activity in human blood platelets and the possible involvement of this enzyme in the process of platelet activation. Using 1-chloro-2,4-dinitrobenzene as a synthetic substrate of the glutathione-S-transferase a rapid dose-dependent depletion of platelet glutathione was measured. The formed GSH-CDNB conjugate was separated by thin-layer chromatography. Hints to the formation of leukotriene-like substances by glutathione-S-transferase catalysed reaction were obtained using the specific leukotriene C antagonist FPL 55 712 in aggregation studies.

Arachidonic Acid↗
PubMed1983

Effect of compounds causing reversible perturbation of the cellular thiol-disulfide status on the aggregation of human blood platelets.

Diamide, cumene hydroperoxide, t-butyl hydroperoxide and divicine are compounds which cause a reversible oxidation of cellular SH groups. They influence the aggregation of human platelets in a common manner when added to platelet rich plasma, simultaneously with different types of aggregation inducer: (1) The initial phase of aggregation becomes accelerated. This is accompanied by a more sensitive response to the inducer. (2) The aggregation becomes reversible. The accelerated initial phase of aggregation is followed by a switchover to deaggregation. Addition of diamide to platelet suspensions results in an immediate and fast diminution of the platelet GSH level. Extent and duration of the GSH fall depend on the diamide concentration used. The time courses found for the platelet GSH level suggest a causal connection with the altered aggregation response. Therefore, the conclusion is drawn that perturbation of the cellular thiol-disulfide status influences a fundamental and common part of the platelet activation sequence.

Arachidonic Acid↗
PubMed1983

Differences in morphology and protein pattern of human blood platelets during irreversible and diamide mediated reversible aggregation.

Morphological alterations of platelets during reversible aggregation mediated by diamide are compared with those observed during irreversible aggregation. Diamide prevents cell fusion and the formation of loop-like structures which probably arise from fusing plasma membranes. Differences in the protein pattern of platelets after reversible and irreversible aggregation suggest a specific involvement of SH-proteins in irreversible platelet aggregation. The diamide mediated alterations of platelet aggregation behaviour are transitory, i.e. reversibly aggregated platelets respond normally to a new addition of aggregation inducers without and with diamide, respectively.

Arachidonic Acid↗
PubMed1983

[Conservation of the mandible by osteotomy-osteosynthesis in "trans-mandibular" oropharyngectomy. 34 case reports].

Trans-mandibular oropharyngectomy was performed in 34 patients, as initial treatment in 20 cases and following tumoral recurrence after radiotherapy in the other 14 cases. Results indicate that mandibular conservation is possible when bone is not affected by the neoplastic process and when an oropharyngoplasty ensures perfect covering of the mandible. The site of choice for osteotomy-osteosynthesis appears to be the parasymphysial region, as this provides a very satisfactory route of approach, the mental nerve and innervation of the lip are respected, it is situated outside of the irradiation field (before or after surgery), and there are no dental articulation complications.

Humans↗
PubMed1983

[Ligation of the external carotid in the parotid space. Its surgical significance].

The classical procedure of external carotid artery ligature in the carotid sulcus presents certain difficulties: The subdiagastric lymph nodes and branches of farabeuf's venous trunk must be avoided, and major nerves and vessels, including the hypoglossal nerve, internal carotid artery, and internal jugular vein, identified and protected. An approach to the external carotid artery at its entry into the parotid space, as employed in parotidectomy, avoids such problems due to major anatomical elements. This technique appears to be simpler, less restrictive, and more rapidly accomplished than the classical method of ligature, when its objective, the most frequent one, is arrest or prevent ion of hemorrhage in the region supplies by the internal maxillary artery.

Carotid Artery, External↗
PubMed1983

[Treatment of florid oral papillomatosis. Apropos of 10 cases].

Florid oral papillomatosis is a well defined, not exceptionally observed clinical entity of unknown pathogenesis. The exuberant lesions are characterized by their benign appearance on histology, but this is usually associated with a marked capacity for progression and recurrence and a tendency for epitheliomatous degeneration. Based on a review of cases in the published literature and a series of ten patients treated personally, it would appear that radiation therapy should be formally excluded, and that the treatment of choice is by wide excision associated, whenever possible, with reconstructive surgery.

Aged↗
PubMed1982

[Relations between sinus aspergillosis, primary rhinoliths and dental pathology].

Sinus aspergilloses, which can be classified as aspergillar sinusitis and pseudo-tumoral forms, are probably much more prevalent than would appear form the published literature. Many cases of caseous sinusitus reported since the end of the last century were probably unrecognized aspergillosis infections. In the same way, primary rhinoliths can probably be related to aspergillosis. Many cases of sinus aspergillosis appear to be of dental origin, particularly when radiography detects the presence of dental obturation paste in the sinus opacity: this appearance in the sinus opacity: this appearance is almost pathognomic of the affection. Sinus aspergillosis should be recognized as recovery can be obtained in the majority of cases by simple sinus washouts, without the need for chemotherapy.

Adult↗
PubMed1981

[Course and prognosis of pregnancy, delivery and childbirth in patients with congenital heart defects].

On the conditions of an optimal therapy and with reference to certain contraindications the prognosis of patients with congenital heart diseases and their children scarcely differs from that of the normal population during gestation. The rate of decompensation in pregnancy was 4.1%, with 3.9% the rate of gestosis was significantly below that of the other patients. The perinatal mortality of the children of patients with congenital vitium cordis os 2.23%, the rate of newborn of 11.2% and the proportion of hypotrophic children of 8.38% were also not increased compared with the totality. By changed diagnostic and therapeutic conditions the relation of the congenital to the acquired vitia cordis has much altered in favour of the congenital ones. With a high proportion of women who underwent an operation of the heart among our patients the results shows that, apart from the already generally accepted absolute contraindications for a pregnancy, the prognosis for patients with stenoses of the outlet is clearly worse than that of the patients with other congenital heart diseases.

Female↗
PubMed1980

Anticoagulant-free prepared blood platelets and the effect of calcium on their aggregation behaviour.

Human blood platelets were prepared by gel filtration of native blood and subsequent centrifugation in a Ficoll density gradient avoiding any anticoagulant during the preparation. In ADP, ionophore A 23 187 and thrombin induced aggregation an increase in extracellular Ca++ enhanced the velocity of aggregation. From a defined Ca++ concentration threshold on there was a shift from monophasic to biphasic aggregation.

Adenosine Diphosphate↗
PubMed1979

The use of acridine orange for testing blood platelet integrity.

Two processes are involved in the accumulation of acridine orange in human blood platelets. One follows a diffusion like kinetics and is independent of the ATP level whereas the second one can be completely abolished by ATP depletion. The acridine orange incorporation rate seems to be a suitable parameter for testing platelet integrity. It reflects very sensitively the influence of the preparation method as well as of anticoagulating substances used on the stability of platelet suspensions. The rates of acridine orange incorporation and of aggregation were measured in platelet-rich plasma and in saline suspended platelets after gel filtration, respectively, over a period of 120 min storage. Both rates are influenced to a different degree by anticoagulating agents such as citrate, heparin and EDTA. When contact with anticoagulating agents during platelet preparation is avoided, platelets show a constant acridine orange incorporation and aggregation during storage and the smallest morphological alteration.

Acridine Orange↗
PubMed1979

[Preparation of human platelets without the use of anticoagulants and study of the effect of Catt on aggregation].

A method for the preparation of human blood platelets is presented which substitutes the use of anticoagulants by a gelfiltration for the removal of plasma calcium from native blood. In a second step the platelets are separated from the gel filtered blood by a centrifugation on a Ficoll density gradient. The anticoagulant-free platelets reveal an intact morphological feature and a normal aggregation behaviour in response to different aggregation inducers. It was found that in ADP-induced aggregation monophasic aggregation is shifted to a biphasic one by increasing concentrations of extracellular calcium.

Blood Platelets↗
PubMed1977

[Evaluation of diagnostic parameters in chronic recurrent urinary tract infections in children. IV. The isotopic renogram (author's transl)].

The results of isotopic renograms (ING) (n = 73) and renal concentration capacity tests (n = 65) performed at the same time before and during therapy of recurrences have been compared. In 43 children with chronic urinary tract infections. ING done prior to chemotherapy showed pathologic findings in 65% of children with bacteriuria. A significant correlation between normal and pathologic findings of ING and renal concentration capacity tests has been found. Impaired (normal) renal concentration capacity lead to pathologic (normal) ING in 74% of cases. 94% of children with a pathologic ING either had bacteriuria children with pyelonephritis (n = 19) the ING was pathologic, whereas in all children with cystitis (n = 8) it was normal. During therapy the ING became normal before the impaired renal concentration capacity returned to normal.

Adolescent↗