Biomedical subjects
Publications and source records attributed to M Hartmann.
1. The authors elaborated and tested a computer method for assessment of vision. This method is compatible with the basic procedure for assessment of vision and its variability. 2. The authors recommend to supplement values of vision by the parameter of line steepness. This parameter is independent on the value of vision and gives the number of normalized lines on which the number of correctly assessed optotypes declines from 95 to 5%.
Examination of the contrast sensitivity in aphakic eyes corrected by glasses and in artephakias provides information which cannot be obtained by measurement of visual acuity and is thus a suitable supplement of the basic test of visual functions. Contrast sensitivity declines significantly with advancing age. Contrast sensitivity of aphakic eyes corrected by glasses corresponds to values of contrast sensitivity of phakic eyes of the same age group. Artephakias with an iris clip lens have a contrast sensitivity reduced by cca one half as compared with a control group, while in artephakias with a posterior chamber lens there is a decline by one third, as compared with a control groups of the same median age.
The authors deal with the relationship between changes of components of the electroretinogram, i.e. their reduction, and the degree of affection of the retina in diabetes mellitus. The group of 145 examined subjects was divided into 5 sub-groups with regard to the severity of retinal affection, and electroretinographic examinations were made. For evaluation logistic functions and other statistical methods were used. From the results it was concluded that the validity of the relationship applies only to advanced affections of the retina, while in early cases this relationship is uncertain.
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Ischemic spinal cord injury after aortic cross-clamping may be produced by a steal phenomenon. The present study investigates this possibility by directly measuring the oxygen tension on the spinal cord surface in pigs. After simple clamping of the aorta, oxygen tension decreased significantly distal to the clamping site both after occlusion of the thoracic aorta at T3-4 (group 1) and after occlusion of the abdominal aorta at L-1 (group 2). Exclusion of the thoracic aorta by a second clamp at T-13 restored oxygen tension almost to the original level, whereas segmentation of the abdominal aorta up to S-1 hardly affected oxygen tension in the area of the artery of Adamkiewicz in most of the animals. We conclude that after aortic cross-clamping, blood tends to drain away from the spinal cord rather than supplying it longitudinally. Without knowledge of the position of the Adamkiewicz artery in humans as well as of the competence of the collateral circulation in the excluded segment, it is necessary to develop a new strategy for repair of the aorta. We describe and discuss two surgical techniques for the prevention of paraplegia after aortic cross-clamping: the counterocclusion technique and the bypass fractionated technique.
The effects of H+, K(+)-ATPase inhibitor BY 1023/SK&F 96022 on pentagastrin-stimulated acid secretion have been studied in healthy male volunteers (n = 12). The gastric acid response to submaximal pentagastrin-stimulation (0.6 micrograms/h/kg b.w.) was dose-dependently inhibited. A single dose of 5 mg decreased acid output by 22% while after 60 mg and 80 mg secretion was almost completely abolished. A good dose linearity was observed for AUC (0, infinity) and Cmax over the dose range from 5 to 80 mg. Elimination half-life, total clearance and volume of distribution of the parent compound were independent of the dose. The drug was well tolerated up to the highest dose of 80 mg. No clinically relevant influence was found on either laboratory screen or cardiovascular parameters.
This study aimed to describe the distribution of a membrane protein called Gz-1-Ag in embryonal rat tissues using monoclonal antibodies. Three monoclonal antibodies recognizing different antigenic determinants of Gz-1-Ag were tested on different stages of rat embryos-fertilized oocytes, two-cell stages, morulae, blastocysts and embryos up to 17.5 days old. The embryos were fixed by different methods; the Tokuyasu method was the most convenient. It yielded very good morphological conservation, good preservation of antigenicity and weak background fluorescence. Gz-1-Ag was detected in practically all early epithelial structures, but the intensity of fluorescence varied. Fluorescence was not associated with the germ layer from which the epithelium derived. The uninterrupted presence of Gz-1-Ag from the fertilized oocyte to all subsequently arising epithelial structures suggests a role of Gz-1-Ag in cell adhesion, secretory processes or the intercellular exchange of information or substances.
A total of 234 urogenital specimens were investigated with a radioactive and a nonradioactive rRNA:cDNA-hybridization test for the direct detection of Chlamydia trachomatis (Gen-Probe, San Diego, Calif.). The results were compared with those yielded by the conventional cell culture technique (McCoy cells). Using cell culture a urogenital C. trachomatis infection could be detected in 37 of 234 patients (15.8%) at two outpatient sexually transmitted disease clinics. Referred to the detection rate, cell culture sensitivity was 83.8% for the radioactive test and 86.5% for the nonradioactive DNA-hybridization test. The specificity of the radioactive test was 94.8% and that of the nonradioactive test, 93.4%.
The therapy of choice for oral hairy leucoplakia in HIV-infected patients is treatment with acyclovir. During treatment the replication of Epstein-Barr Virus (EBV) in cells scraped from the epithelium of hairy leucoplakia was investigated using filter-in-situ hybridization. On the 2nd day of treatment a slight and on the 5th day a marked reduction of the replication was observed, and on the 8th day of treatment replication of EBV could hardly be detected. At that time a marked regression of leucoplakia was seen. Within another 7 days the lesions had completely disappeared. These findings demonstrate the relationship between treatment with acyclovir and inhibition of EBV replication in hairy leucoplakia and the relationship between inhibition of EBV replication and remission of hairy leucoplakia.
The GZ100 series comprises a panel of monoclonal antibodies which seem to be specific for human trophoblast antigens (with the exception of GZ111, which reacts with a number of other tissues). The GZ antibodies show different reaction patterns with different trophoblast cell types. As a panel the GZ antibodies recognize all trophoblast populations (Table 2). Thus these antibodies provide a means to distinguish between trophoblast cells and maternal cells. GZ112 might be used to sort out HLA-class I positive trophoblast cells of the basal plate without blocking the HLA antigenic determinant, since GZ112 is not an anti HLA-class I antibody. At present the antigens detected by the GZ antibodies seem to be proteins, most of them with molecular weights between 50 kD and 80 kD. The function of these antigens is unclear and will be studied in future.
Carrier experiments using Echo- and Influenza-viruses on denture basis resins and fragments of orthodontic appliances resulted in good and even very good virucidal effects of disinfectant sprays Desident and Fesia-sept. The application of the disinfectant as spray seem to be advantageous, but is not recommendable. The diverse causes of this conclusion are discussed and an alternative way is proposed.
The objective of the study was to investigate the pharmacodynamics and pharmacokinetics of the gastric H+, K(+)-ATPase inhibitor pantoprazole in man following repeated i.v. dosing. 8 healthy male volunteers aged from 25 to 31 years (median: 29 years), body weight between 72 and 95 kg (median: 82 kg) entered this single-blind two-period cross-over study. Each subject underwent two treatment periods of 5 days each with daily infusion of 15 mg or 30 mg pantoprazole, respectively. A placebo day preceeded the trial. On the placebo day as well as on days 1, 4 and 5 of each treatment period, gastric secretion was stimulated submaximally by a pentagastrin infusion of 0.6 micrograms/h/kg over a period of 4 h, starting one hour before administration of drug or placebo. Repeated once-daily infusion (15 min) of pantoprazole resulted in a rapidly increasing pharmacodynamic effect: as compared to placebo the mean percent inhibition of acid output measured from 1 to 3 h after start of infusion was 22%, 63% and 78% for the 15 mg dose, and 56%, 97% and 99% for the 30 mg dose on days 1, 4 and 5, respectively. The pH also increased in relation to the dose and the duration of treatment. Mean fasting gastrin serum concentrations increased by about 50%, yet remained within the normal range. Only in one subject, one of the individual values was above the upper limit of the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)
In an open prospective study we investigated the efficacy of the supplementation of analgosedation by clonidine. 40 patients with oesophagus malignancy and definite alcohol abuse were on respiration therapy postoperatively after having been treated with oesophago-gastro anastomoses. With regard to manifestation intensity and development of withdrawal symptoms we found that during basic medication with piritramid-diazepam continuously i.v. administered clonidine can eliminate haemodynamic and psychovegetative symptoms related to alcohol withdrawal. The clonidine group required less analgosedation. The measurement of the urinary catecholamine output showed a normalised endogenous output. As a finding of importance the gastrovolume was reduced, and the haemodynamically firm, stable and less sedated patients of the clonidine group required fewer days of respiration therapy. Hence, the hazard of aspiration pneumonia and insufficienty anastomosis was lower. Risk of bradycardia of high potential danger did not occur with a median daily dosage of 1.09 mg/d clonidine. We consider clonidine to be a potent supplement to analgosedation for the surgical patient who is at high risk of alcohol withdrawal.
The frequency of chlamydial infections was investigated by means of the McCoy culture technique and a serological procedure using the microimmunofluorescence test in female outpatients showing suspect symptoms; in patients suffering from acute salpingitis, and in women with involuntary infertility. In 18.6% of 290 subjects of the first group, chlamydiae were isolated from cultures. Of 26 patients with acute salpingitis, Chlamydia trachomatis could be detected in 10. The high frequency of positive serological tests suggests chlamydial infection to constitute an important etiological factor in female infertility and extrauterine pregnancies.
A DNA segment covering the signal sequence coding region, the ribosome binding site, and the promoter of the staphylokinase (sak) 42D gene (Behnke and Gerlach 1987) was cloned into pUC19 to form a portable expression-secretion unit (ESU). Fusion of human interferon alpha 1 (hIFN alpha 1) and hybrid hIFN alpha 1/2 genes to this sak ESU resulted in secretory expression of the two gene products in both Escherichia coli and Bacillus subtilis. While most of the IFN alpha was exported to the periplasmic space of E. coli, about 99% was secreted to the culture medium by recombinant B. subtilis strains. The total yield in E. coli was 1.2 x 10(5) IU/ml. This level of expression and export led to instability of the recombinant strains that was spontaneously relieved in vivo by inactivation of the sak ESU through insertion of an IS1 element. No such instability was observed with B. subtilis although expression and secretion levels reached even 3 x 10(6) IU/ml. Proteolytic degradation of IFN alpha by extracellular proteases was avoided by a combination of constitutive expression and secretion during the logarithmic growth phase and the use of exoprotease-reduced host strains. The IFN alpha 1 protein purified from B. subtilis culture supernatant was correctly processed, carried the expected 11 amino acid N-terminal elongation that resulted from DNA manipulations and proved to be homogenous in Western blotting experiments. The same recombinant plasmid that directed efficient secretion of hIFN alpha 1 in B. subtilis gave poor yields when introduced into Streptococcus sanguis.
A radioactive cDNA probe complementary to chlamydial ribosomal RNA was used to detect C trachomatis in urogenital specimens. Of 37 specimens positive with cell culture 31 were confirmed by the rRNA:cDNA hybridisation test, the sensitivity being 83.8%. The specificity of the hybridisation test was 94.4%, as 186 of 197 specimens that were negative by cell culture were also negative when assessed by the hybridisation method. Given a prevalence of 15.8% the predictive values for positive and negative results were 73.8% and 96.9%, respectively. In additional experiments the possible role of microorganisms added to the specimen collection medium was investigated. However, no indication for crosshybridisation was found; at high concentrations microorganisms interfered with the test procedure.
Blood plasma samples from HIV-1-infected persons contain elevated glutamate concentrations up to 6-fold the normal level and relatively low concentrations of acid-soluble thiol (i.e. decreased cysteine concentrations). The intracellular glutathione concentration in peripheral blood-mononuclear cells (PBMC) and monocytes from HIV antibody-positive persons are also significantly decreased. Therapy with azidothymidine (AZT) causes a substantial recovery of the plasma thiol levels; but glutamate levels remain significantly elevated and intracellular glutathione levels remain low. Cell culture experiments with approximately physiological amino-acid concentrations revealed that variations of the extracellular cysteine concentration have a strong influence on the intracellular glutathione level and the rate of DNA synthesis [( 3H]thymidine incorporation) in T cell clones and human and murine lymphocyte preparations even in the presence of several-fold higher cystine and methionine concentrations. Cysteine cannot be replaced by a corresponding increase of the extracellular cystine or methionine concentration. These experiments suggest strongly that the low cysteine concentration in the plasma of HIV-infected persons may play a role in the pathogenetic mechanism of the acquired immunodeficiency syndrome.
Five hundred and seventy-five patients with acute epididymitis were hospitalized between 1979 and 1987, and 149 of them (25.9%) underwent surgery to the epididymis or the testis. For removal of the morphological alterations responsible for the inflammation, secondary operations were required in 157 cases (27.3%). We divided the patients into four age groups (under 15 years, 15-30 years, 31-60 years and more than 60 years), because the operative treatment indicated depends partly on the patient's age. For every age group the value of different follow-up examinations was checked. Prepubertal children have to be considered separately.