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Biomedical subjects

M Hoffman

Publications and source records attributed to M Hoffman.

At least 343 records · Page 19Linked to original sources
PubMed1983

Alpha 2-macroglobulin 'fast' forms inhibit superoxide production by activated macrophages.

Mouse peritoneal macrophages activated by bacillus Calmette-Guerin (BCG) were incubated with human alpha 2-macroglobulin converted to its 'fast' form with either trypsin or methylamine before being stimulated with phorbol myrystate acetate. Both alpha 2-macroglobulin-trypsin and alpha 2-macroglobulin-methylamine inhibited macrophage production of superoxide anion (O2-) while native alpha 2-macroglobulin had little effect except at high concentration. The alpha 2-macroglobulin 'fast' forms, which bind with a Kd of about 8 nM, inhibited 50% generation of O2- (ID50) at a concentration of 7 nM while alpha 2-macroglobulin inhibited O2- production with an ID50 of 141 nM. The 'fast' forms of alpha 2-macroglobulin may play a role in the feedback regulation of inflammatory reactions.

Animals↗
PubMed1983

[Non-invasive methods in the diagnosis of latent heart rhythm disorders].

In the investigations carried out the value of the noninvasive methods (routine-, three-minute-, 24-hour-, and load-ECG) for the diagnostics of latent ventricular disturbances of cardiac rhythm was controlled. 114 registrations of ventricular arrhythmias according to the Lown-classes with increasingly prolonged periods (1, 6, 12, and 24 hours) show that for the establishment of a ventricular extrasystolia of the classes IV and V a registrations lasting at least 24 hours is necessary. 1- and 3-minute-ECG are not suited for this. The load-ECG has a limited value in the diagnostics of the ventricular arrhythmias. In 155 persons by means of the transoesophageal diagnostic atrial stimulation additionally the sinus node recovery time and the sinuatrial conduction time were determined. In 33 patients of the group with sinus node syndrome the 24-hour-ECG was registered. The sensitivity for the sinuatrial conduction time is 75% and for the sinus node recovery time is 82%. Altogether the two investigation methods, the non-invasive electrophysiology and the long-term ECG, allowed to make a correct diagnosis in 94% of the patients with sinus node syndrome.

Adult↗
PubMed1983

Cytomegalovirus-infected cell polypeptides immune-precipitated by sera from children with congenital and perinatal infections.

Congenital or perinatally acquired human cytomegalovirus (CMV) infections in children may be symptomatic or asymptomatic. In this study, we characterized the electrophoretic properties of CMV-infected cell polypeptides immune-precipitated by sera from children with different types of CMV infections from birth to 4 years of age. Sodium dodecyl sulfate-polyacrylamide gel analysis of immune precipitates formed with radiolabeled extracts of cells infected with CMV strain AD169 showed the following. (i) Electrophoretic profiles of CMV polypeptides immune-precipitated by sera from children with perinatal and congenital infections were similar. At least 11 polypeptides with apparent molecular weights of 150,000, 140,000, 110,000, 100,000, 74,000, 66,000, 50,000, 49,000, 34,000, 25,000, and 20,000 were precipitated. Antibody titer in anticomplement immunofluorescence tests and virus titer in urine correlated with the intensity of polypeptide profiles in autoradiograms. (ii) The initial immune response of children with symptomatic congenital infections was delayed as compared to that of children with asymptomatic congenital and perinatal CMV infections. Sera obtained serially from symptomatic children for years after birth continued to precipitate CMV polypeptides, whereas sera from children with subclinical congenital infections precipitated lesser amounts over time. (iii) Immune precipitates obtained with sera from CMV-infected patients and with monoclonal antibodies to CMV contained polypeptides with comparable electrophoretic and immunological properties.

Antibodies, Monoclonal↗
PubMed1982

Acute haemorrhagic conjunctivitis.

An extensive outbreak of acute haemorrhagic conjunctivitis is being experienced in South Africa. This is part of a pandemic affecting Africa, Asia and the Americas. It is thought to be caused by enterovirus 70 and is highly contagious, the main mode of transmission being direct contact. The disease is usually confined to the eye and is self-limiting, requiring only symptomatic treatment. Sequelae have been reported, most concern being caused by the neurological complications.

Acute Disease↗
PubMed1982

Effect of cyclooxygenase inhibitors and protease inhibitors on phorbol-induced stimulation of oxygen consumption and superoxide production by rat pulmonary macrophages.

Oxygen consumption and superoxide anion production by pulmonary macrophages are both increased by phorbol myristate acetate (PMA) but the two processes have been separated using protease inhibitors and cyclooxygenase inhibitors. Pretreatment with the protease inhibitors (L-1-tosylamido-2-phenylethylchloromethyl ketone (TPCK) and N-alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK), as well as with the cyclooxygenase inhibitors acetylsalicylic acid (ASA) and ibuprofen (IBU), inhibited the stimulation of superoxide production and oxygen consumption by phorbol myristate acetate. However, whereas the order of potency for inhibition of stimulation of superoxide production was TPCK greater than TLCK greater than IBU greater than ASA, the order of potency for inhibition of stimulation of oxygen consumption was ASA greater than IBU greater than TPCK = TLCK. Although all four agents were effective inhibitors of PMA-stimulated superoxide production and oxygen consumption when added before PMA, in contrast to the cyclooxygenase inhibitors. TPCK was unable to inhibit oxygen consumption by more than 70-80% regardless of the concentration used, although superoxide generation could be inhibited completely. When added after PMA, ASA did not suppress either oxygen consumption or superoxide production and ibuprofen was only one-half as effective as an inhibitor. TPCK and TLCK, when added after PMA, accelerated the return to basal rates of both oxygen consumption and superoxide production. None of the four agents had any effect on basal superoxide production or oxygen consumption at the concentrations used. The data support the interpretation that both prostaglandin biosynthesis and protease activity may be associated with the activation of the superoxide-generating system of pulmonary macrophages. The consumption of molecular oxygen following stimulation of the cells with phorbol myristate acetate is not due solely to the generation of superoxide, however, since each process is inhibited with different potency by the same group of inhibitors. There appears to be a component of oxygen consumption which results from the activation of cyclooxygenase and, unlike superoxide production, cannot be completely inhibited by treatment with protease inhibitors.

Animals↗
PubMed1982

Ibuprofen-induced meningitis in mixed connective tissue disease.

A young Black woman with mixed connective tissue disease (MCTD) developed an aseptic meningitis after receiving ibuprofen. The meningeal reaction, reported infrequently in systemic lupus erythematosus (SLE) and only once previously in MCTD, was characterized by a predominantly polymorphonuclear cerebrospinal fluid (CSF) pleocytosis and depression of CSF glucose. Reversible renal insufficiency also occurred. Features suggestive of a hypersensitivity reaction included pruritus, conjunctivitis, facial oedema, desquamation of the palms and soles, and subsequent near total alopecia. Meningeal signs responded rapidly to systemic corticosteroid therapy. Patients with MCTD as well as those with SLE may be at peculiar risk of developing this uncommon reaction to ibuprofen.

Adult↗
PubMed1982

Hall effect transducer for apexcardiography and sphygmography.

Recording of mechanograms (Recording of mechanical activity of internal organs and vessels, often non-invasively eg. apex cardiogram) can be performed by applying different kinds of mechano-electric transducers. In this paper the idea and construction of a new transducer with Hall-generator are presented. This transducer is self-adjusting in the range of its linear characteristics, and exerts practically constant touching pressure independent of the configuration of the patients thorax. This facilitates the measuring process and allows for calibration of the obtained records. The sensitivity of the transducer is 250 mV/mm, frequency bandwidth 0-45 Hz and it has a linearity of +/- 1.5% in the range of displacements +/- 1.5 mm. The transducer also generates the signal of the first derivative of the investigated vibrations. Assessment of the transducer was carried out in a cardiology clinic on 27 patients with a normal heart and with different kind and degree of heart damage. The mechanograms obtained from different transducers for each patient were compared in respect of the essential time intervals and morphological elements. The comparison shows a good detecting capability, correctness and reproducibility of the data obtained by means of the Hall-effect transducer. Some recordings of mechanograms (apexcardiograms and different kinds of pulse) from patients with normal heart, valvular aortic stenosis and atrial heart defect are shown and discussed in the paper.

Heart Diseases↗
PubMed1982

Monoclonal antibodies to human cytomegalovirus: three surface membrane proteins with unique immunological and electrophoretic properties specify cross-reactive determinants.

Seventy-seven clones of hybridomas selected for reactivity by immunofluorescence with human cytomegalovirus (CMV)-infected cells were produced by fusing mouse myeloma cells with the spleen cells of mice immunized with CMV strain AD169. The clones were classified into seven groups on the basis of the electrophoretic properties of the polypeptides immune precipitated from extracts of CMV-infected cells. Studies on the three groups of monoclonal antibodies directed against CMV surface membrane antigens showed the following. Clones in each group were differentiated by immunoglobulin subclass, neutralizing activity, and reactivity with the antigenic domains of proteins exposed on the surface membranes of intact CMV-infected cells. Monoclonal antibodies in each group precipitated one slowly migrating protein and multiple faster migrating forms which shared antigenic determinants. The first group of monoclonal antibodies precipitated four glycosylated polypeptides with apparent molecular weights of 130,000, 110,000, 100,000, and 60,000. Monoclonal antibody CH51 of this group neutralized infectious virus but failed to react with antigenic domains on the surfaces of infected cells. The second group of monoclonal antibodies precipitated four polypeptides with apparent molecular weights of approximately 66,000, 55,000, 50,000, and 46,000. Monoclonal antibodies CH65 and CH134 in this group had neutralizing activity and reacted with antigenic domains of proteins exposed on the surface of CMV-infected cells. The third group of monoclonal antibodies precipitated four polypeptides with apparent molecular weights of 49,000, 48,000, 34,000, and 25,000. Serological analysis of 15 naturally occurring CMV strains with a panel of monoclonal antibodies to surface membrane proteins showed that the antigenic determinants reactive with the antibodies tested were conserved in all of the strains. Monoclonal antibodies to surface membrane proteins on CMV-infected cells may prove to be valuable reagents for identification of virus isolates.

Antibodies, Monoclonal↗
PubMed1982

Electrophoretic analysis of polypeptides immune precipitated from cytomegalovirus-infected cell extracts by human sera.

Serodiagnosis of cytomegalovirus (CMV) infection by complement fixation tests depends on showing a fourfold rise in antibody titer from acute- to convalescent-phase sera. Freeze-thaw and glycine-extracted, infected cell culture antigens used for these tests give markedly different titers in reactions with the same sera. In this study, we characterized the CMV-infected cell polypeptides contained in freeze-thaw and glycine-extracted antigens and identified the proteins precipitated by 23 pairs of human acute and convalescent sera. Our results were as follows. First, freeze-thaw and glycine-extracted antigens prepared from infected cells radiolabeled with [35S]methionine and subjected to electrophoresis in sodium dodecyl sulfate-polyacrylamide gels yielded similar patterns, and the bulk of the label was contained in late structural proteins and glycoproteins. Glycine-extracted preparations contained a greater proportion of soluble 66,000- and 50,000-molecular-weight proteins than did freeze-thaw antigens. Second, convalescent sera precipitated proteins migrating with apparent molecular weights of 150,000, 130,000, 110,000, 96,000, 74,000, 66,000, 50,000, 34,000, 32,000, and 25,000. Of these the 130,000-, 110,000-, 96,000-, 66,000-, 50,000-, and 25,000-molecular-weight proteins comigrated with glucosamine-labeled polypeptides. Both immunoglobulin G and M antibodies in human sera precipitated these proteins from CMV-infected cell preparations. Implications of the results for serodiagnosis of CMV infections are discussed.

Antibodies, Viral↗
PubMed1982

[Dermatitis of the scrotum].

The scrotal dermatitis is a syndrome with itching, oedema, scales and lichenification. Those symptoms change according to the aetiology agent. In the research of mycological and bacteriological elements was found "Candida" and staphilococus as the most common agent. This aetiology agent on an abnormal skin plus the rubbing and the soaking can explain the pathogenesis of this dermatosis.

Adolescent↗
PubMed1982

Operation for ruptured abdominal aortic aneurysms: a community-wide experience.

From 1975 through 1979, 29 members of The Cleveland Vascular Society operated on 1049 patients with abdominal aortic aneurysms; of these, 152 ruptured aneurysms. The postoperative mortality rate was 38% (58 of 152). In 27% (41 of 152) of the patients, a diagnosis was made prior to rupture, and the average interval from diagnosis rupture was 16 months. A history of diabetes, hypertension, or a single myocardial infarction (MI) prior to rupture was not associated with an increased mortality rate. Patients with a history of more than one MI prior to rupture had a 75% (six of eight) mortality rate. The average time from onset of symptoms to examination was 2 days 10 hours. When the initial diagnosis was correct, or an intra-abdominal disease was at least suspected, the mortality rate was 35% (47 of 135). When the initial diagnosis was incorrect and a cardiopulmonary or cerebral cause was suspected, the mortality rate was 75% (13 of 17). When the diagnosis was incorrect, the interval from diagnosis to surgery was 2 1/2 days. With only intramural bleeding or a small hematoma in the area of rupture, the mortality rate was 17% (4 of 24); when the hematoma was more extensive, the mortality rate was 43% (55 of 128). This study encompassed a large number of operations performed in a metropolitan area during a relatively short period of time, during which there had been few changes in operative technique or supportive measures. It demonstrated that the most critical factors influencing survival were correct initial diagnosis, the extent of the hematoma, and the history of more than one preoperative MI.

Aged↗