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Biomedical subjects

H Breithaupt

Publications and source records attributed to H Breithaupt.

At least 73 records · Page 4Linked to original sources
PubMed1979

Electron spin resonance (esr) investigations on blood of patients with leukemia.

ESR investigations of lyophilized blood of patients with acute lymphatic leukemia exhibit an increase in spin concentration and an additional peak not present in control samples. This peak disappears almost completely concomittantly with a reduction in spin concentration after treating the patients with prednisolone, vincristine, and doxorubicin or after addition of 5mM of CuCl2 to blood samples. The results show that the ESR spectra of lyophilized blood samples can be utilized to follow the effect of therapy. Moreover, they suggest that the leukemic blood possesses a high concentration of antioxidants.

Adult↗
PubMed1978

HLA-B27, antinuclear antibodies and drug-induced agranulocytosis.

Eight female patients with drug-induced agranulocytosis (five patients with definite seropositive rheumatoid arthritis (RA), three patients with upper respiratory infections) were studied for the presence of HLA-B27 and antinuclear antibodies (ANA). Five of eight patients were found to be HLA-B27 positive and all RA patients had ANA in their serum. The frequency of HLA-B27 and ANA was found to be significantly different from control groups. It is concluded that the occurrence of HLA-B27 and ANA was found to be significantly different from control groups. It is concluded that the occurrence of HLA-B27 in female patients with seropositive RA (especially in those with ANA) and of HLA-B27 alone in other individuals could reflect an increased risk for drug-induced agranulocytosis.

Adolescent↗
PubMed1976

Neurotoxic and myotoxic effects of crotalus phospholipase A and its complex with crotapotin.

1. The acidic peptide crotapotin potentiated the toxicity of the basic crotalus phospholipase A in all species tested. The order of sensitivity to the lethal action of the phospholipase was: chick greater than mouse larger than or equal to rabbit greater than rat. After a latency period of a least 20 min the animals died of respiratory paralysis. Rabbits survived for more than 10 h, if they were artificially respired. The animals recovered very slowly from respiratory depression. 2. In rabbits even high doses of the basic crotalus phospholipase A or its complex with crotapotin did not affect the respiratory center nor its reactivity to asphyxia. Conduction of action potentials in the phrenic nerve was not changed. 3. Phospholipase-crotapotin complexes decreased the contractile response of isolated phrenic-hemidiaphragms of rats to direct and indirect stimulation in an irreversible manner. A latency period 20-100 min preceded the paralysis. 4. A similar block of neuromuscular transmission developed in vivo. After i. v. injection of PC-complexes the contractile response of isolated rat phrenic diaphragms to nerve stimulation was considerably lower than to direct stimulation. 5. Crotalus phospholipase A alone as well as its complex with crotapotin reduced the contractions of the isolated chick biventer cervicis muscle but did not cause a contracture, thus indicating that the phospholiphase PC-complexes act not as depolarizing blockers. 6. Blood pressure, heart rate and electrocardiogram were not substantially altered, when phospholipase A or PC-complex were injected slowly i.v. into rabbits or rats. No cardiotoxic effect was observed in the Langendorff preparation of rat hearts perfused with phospholipase A alone (6 x 10(-6) M) or together with crotapotin (10(-5) M). Rapid i.v. injection of the venom produced hypotension. The degree of haemolysis correlated with the enzymatic activity, and was low for the highly toxic PC-complexes.

Action Potentials↗
PubMed1975

Isolation and characterization of three phospholipases A from the crotoxin complex.

1. Three phospholipases A (phosphatide acyl-hydrolase, EC 3.1.1.4) have been isolated from the crotoxin complex, the main toxic compound of the Crotalus durissus terrificus venom. 2. Two basic phospholipases A were highly purified from the crotoxin complex by single chromatography on carboxymethyl cellulose. The yields were 10% and 38% (w/w), respectively. They showed no differences with regard to isoelectric point, enzymatic activity, immunological properties, and toxicity. One acidic phospholipase A, purified to a final yield of 1-3% by chromatography on carboxymethyl cellulose, gel filtration on Sephadex G-50, and chromatography on DEAE-cellulose, was found to have one third of the specific enzymatic activity of the basic enzymes. The acidic phospholipase A was nontoxic and antigenically different from the basic enzymes. 3. Crotapotin, an acidic peptide of the crotoxin complex (31% yield, w/w), potentiated the toxicity and inhibited the enzymatic activity of the basic phospholipase A isoenzymes, but did not interact with the acidic phospholipase A. 4. The purified enzymes were homogeneous with respect to cellogel electrophoresis, polyacrylamide gel electrophoresis, dodecyl sulfate-gel electrophoresis, immunoelectrophoresis, and isoelectric focusing. 5. The molecular weights of the three phospholipases were found to be in the same range as determined by gel filtration in 6 M guanidine - HCl (14 500) and dodecyl sulfate-gel electrophoresis (15 800). The isoelectric points of these enzymes were at 9.7 and 4.8 for the first two and the third, respectivlar. The acidic enzyme contained more acidic instead of basic amino acid residues. The two methionine residues of each phospholipase were found to be positioned nearby the NH2 - and the C-terminal of the protein chains. A third methionine residue was demonstrated in the acidic phospholipase A. Fingerprint maps of the basic enzymes showed only slight differences. 7. NH2 - and C-terminal sequence analyses indicated a striking homology between the three Crotalus phospholipase A isoenzymes and several phospholipases from other sources.

Amino Acid Sequence↗