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Biomedical subjects

G Schmidt

Publications and source records attributed to G Schmidt.

At least 253 records · Page 14Linked to original sources
PubMed1990

Suppression of blastogenic transformation of lymphocytes by Bacteroides fragilis in vitro and in vivo.

Bacteroides species and Enterobacteriaceae are known to cause synergistic infections. However, the mechanisms behind this synergy are not completely understood. Several authors have shown that Bacteroides species may inhibit the phagocytosis of Enterobacteriaceae by polymorphonuclear leukocytes as well as by macrophages. With the present study we have addressed the question of whether Bacteroides fragilis (BF) is also capable of suppressing specific immune functions. When incubated together with murine lymphocytes, BF significantly inhibited the blastogenic transformation of these cells stimulated by Escherichia coli-lipopolysaccharide (LPS) or concanavalin A. This effect was dose dependent and was not mediated by prostaglandins. Other bacteria such as E. coli or Listeria monocytogenes did not show such an extensive suppression, while Streptococcus pneumoniae was equally active. BF also inhibited the pokeweed mitogen induced blastogenic transformation of human lymphocytes. Moreover, lymphocytes from BF-injected animals obtained 3 to 12 hours after infection proved to be partly refractory for LPS-stimulation. Finally, BF injections also affected T-cell dependent immunity as judged from the aggravation of an experimental listeriosis in mice.

Animals↗
PubMed1990

[The extent of bacterial contamination of keratoplasty donor eyes post mortem].

In order to determine the initial bacterial contamination of corneal donor material the abraded epithelia from 125 donors, i.e., 250 globes, were examined immediately after enucleation. Of these, 49 (19.6%) were sterile, while 201 (80.4%) were contaminated. Monoinfection was identified in 174 globes and mixed infection in 27. The pathogen most frequently isolated was Pseudomonas aeruginosa. Neither the donor's age not the time elapsed between death and enucleation had any influence on the contamination rate. Prolonged hospitalization of donors leads to an increase in gram-negative bacteria. The necessity of antibacterial prophylaxis prior to keratoplasty is pointed out.

Adolescent↗
PubMed1990

Surgical and electrophysiological observations during clipping of 134 aneurysms with evoked potential monitoring.

Somatosensory evoked potentials (SEPs) were monitored during 113 operations for the clipping of 134 cerebral aneurysms. Changes in peak latency and amplitude of early cortical SEP as well as central conduction time were evaluated. In 58 cases surgical occlusion of arterial vessels or other events occurred, and in 17 of these cases such events were associated with SEP changes or loss. Arterial occlusions resulted from temporary clipping of a feeding blood vessel (22), accidental clipping of a vessel (12), and intentional permanent vessel occlusion (8). A total SEP loss was seen in 2 cases of accidental vessel occlusion and in 6 cases of temporary vessel clipping. Significant SEP changes were found in 6 patients with temporary clipping, and once each with retraction of the cerebellum, retraction of the middle cerebral artery, and after intentional permanent vessel occlusion. Response to these changes included reapplication of aneurysm clips, repositioning of retractors, or removal of temporary clips. Stable SEP signals during 13 cases allowed the surgeon to proceed with the surgical course. Despite the limitations of SEP monitoring in certain anatomical locations, it has been found to be helpful in the operative management of some cases such as multilobed aneurysms of the middle cerebral artery, giant aneurysms, trapping procedures, and procedures requiring temporary vessel occlusion.

Adolescent↗
PubMed1990

Determination of capillary perfusion pattern in rat brain by timed plasma labeling.

The pattern of capillary perfusion was studied in the brain of anesthetized rats. Two plasma labels were used to demonstrate the density of capillaries perfused during a 10-min period [fluorescein isothiocyanate (FITC) globulin], as well as during a 10-, 3-, or 1-s period [lissamine-rhodamine B 200 (RB200) globulin, infused into the left heart chamber], respectively. A special biopsy cutting-freezing system was used to withdraw brain tissue via a cranial window for histological analysis of dye distribution at the end of the infusion period. Complete labeling of all capillaries was already found after 10 s of dye circulation. However, intra-arterial dye infusion for 3 and 1 s led to reduced filling of capillaries: cortex 86.6 +/- 5.2 and 6.8 +/- 1.8%, hippocampus 95.0 +/- 1.6 and 9.9 +/- 2.1%, and thalamus 97.9 +/- 1.0 and 11.7 +/- 1.8%, respectively. The period of 1 s was found to be the circulation time from left heart chamber to brain capillaries. It can thus be concluded that in the studied brain areas greater than 85% of capillaries are reached by a plasma flow within 2 s and that the remaining small fraction completely fills within 10 s.

Animals↗
PubMed1990

Effects of Escherichia coli hemolysin on human monocytes. Cytocidal action and stimulation of interleukin 1 release.

This study reports on the potent cytocidal and interleukin-1 releasing properties of Escherichia coli hemolysin (ECH) on human monocytes. Nanomolar concentrations of purified ECH (250-2,000 ng/ml) caused rapid and irreversible depletion of cellular ATP to levels below 20% of controls within 60 min. Subcytocidal doses (10-200 ng/ml) of ECH induced rapid release within 60-120 min of large amounts of interleukin 1 beta (IL-1 beta) from cultured monocytes. IL-1 beta release occurred in the presence of actinomycin D and cycloheximide, and was thus probably due to processing and export of intracellular IL-1 beta precursor. Incubation of toxin-producing E. coli at ratios of only 0.3-3 colony-forming units per monocyte evoked approximately 50% depletion of total cellular ATP within 90 min. Toxin producers also stimulated synthesis and release of large amounts of interleukin 1, but not of tumor necrosis factor within the same time span. In contrast, non-toxin producers caused neither cell death nor rapid interleukin 1 release. Stimulation of rapid interleukin 1 release coupled with potent cytocidal effects on cells of monocytic origin may represent pathogenetically significant events incurred by bacterial strains that produce ECH and related cytolysins.

Adenosine Triphosphate↗
PubMed1990

Vasoactive intestinal polypeptide in the PMSG-primed immature rat ovary and its effect on ovulation in the isolated rat ovary perfused in vitro.

The immature rat ovary contains VIP immunoreactive nerve fibres sparsely distributed around blood vessels, in the interstitial gland and around follicles. The VIP concentration, measured radioimmunologically, decreased significantly after PMSG treatment (10 i.u.), probably due to ovarian enlargement and oedema, while the total VIP content (total of 0.12 pmol in both ovaries) did not change after PMSG priming. The ovulatory effect of VIP was studied using in-vitro perfused ovaries from immature 28-day-old rats primed with 10 i.u. PMSG. In all ovaries perfused, VIP (10(-7) M) induced ovulations with a rate of 2.33 +/- 0.56. The ovulation rate was significantly lower than that of ovaries stimulated by LH (0.1 microgram/ml) (5.20 +/- 0.86 ovulations per ovary). No synergistic effect on the ovulation rate was seen when LH and VIP were administered together (5.20 +/- 0.49 ovulations per ovary). The results suggest that the neuropeptide VIP may represent one of the local factors involved in the ovulation process.

Animals↗
PubMed1990

[Spontaneous variability of ventricular arrhythmias in follow-up of anti-arrhythmia therapy].

The question of the reliability of ambulatory Holter monitoring for assessment of antiarrhythmic treatment has not been adequately resolved. Even though treatment efficacy had been individually assessed with Holter monitoring in the CAST study, during long-term treatment with class IC antiarrhythmic drugs, there were more deaths among patients receiving active drug than in those in the placebo group. Basic biostatistical considerations: Due to the spontaneous variability of frequency and complexity of ventricular arrhythmias, parametric models were developed with the aid of which normal ranges for spontaneous variability of singular ventricular premature complexes (VPC), couplets and salvos can be calculated. We designed a model which enables rapid visual analysis of the results: spontaneous variability = log (EE Day 2 + 0.01/EE Day 1 + 0.01) where EE is the number of ectopic events. For both days, the mean values per hour are applied. The use of parametric models prerequisites normal distribution of the data which can be achieved with logarithmic transformation. A constant is added to all mean values to preclude the mathematically-inadmissible form of log 0. The magnitude of the constant results in some degree of underestimation of the spontaneous variability. We chose the smallest constant, c = 0.01, consistent with a normal distribution of data. Figure 1 shows the normal range of the variability quotients for VPC in patients with cardiac disease and complex ventricular arrhythmias. The contiguous regions above and below the normal range designate active areas indicative of reduction or aggravation. Determinants of spontaneous variability: Frequency of arrhythmias: The number of VPC per unit of time exerts considerable influence on the spontaneous variability. The more infrequent an arrhythmia, the greater is the fluctuation to be anticipated. The differences in the variability of VPC, couplets and salvos are almost exclusively due to their differing frequencies since, in the presence of comparable frequency, they cannot be distinguished statistically from each other (Figure 2). Type and extent of underlying cardiac disease: In our patient population, there were no differences in spontaneous variability of arrhythmias between patients with coronary artery disease and those with dilated cardiomyopathy (Figure 3). Although in patients with coronary artery disease, as compared to those with noncoronary disease, a higher degree of spontaneous variability has been reported for VPC but, due to the inhomogeneity of the latter group, valid comparison is encumbered. The ejection fraction, the left ventricular filling pressure and the end-diastolic volume do not exert meaningful influence on the spontaneous variability (Figures 4 to 6).(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-Arrhythmia Agents↗
PubMed1990

[Microbial colonization of the upper respiratory tracts of day care children in relation to acute morbidity episodes].

The upper respiratory tracts of 20 children attending a crèche were studied for bacteria up to the 128th day of crèche attendance. To this end nose and throat swabs as well as double blood withdrawals were to determine antibodies against various respiratory viruses. The germ spectrum thus obtained was correlated with the acute pathological processes occurring during the period of investigation. In addition to the normal flora, the nasopharynx of infection-stable children was, with one exception, only populated with gram-positive pathopotent bacteria during the first four months of crèche attendance. In infection-labile children, however, gram-negative pathopotent bacteria, blastomycetes of the Candida group as well as Mycoplasma, virus and mixed infections were discovered apart from gram-positive bacteria. This broad germ spectrum should be taken into wider consideration in the chemotherapy of respiratory infections.

Bacteria↗
PubMed1990

[Growth parameters of female athletes during periods of high training load].

Studies of children participating in elite sport training programmes revealed growth disorders. Longitudinal analyses of female gymnasts (whose bone age was distinctly below chronological age) over a period of two years do not suggest a general tendency to growth inhibition. However, the marked variation in the longitudinal data may indicate retardation in individual cases. An evaluation of the growth parameters is of practical importance for the medical care of children participating in intensive training programmes.

Adolescent↗
PubMed1990

[Albert Reder Ritter von Schellmann (1826-1904)].

Albert Reder von Schellmann (1826-1904) was an important syphilidologist of the Vienna Medical School in the second half of the nineteenth century. He went in for the dualistic concept of the origin of syphilis and ulcer caused by soft chancre. In 1870 - Reder became head of a third dermato-syphilidologic department in the "Josephinum" in Vienna, where military surgeons got their medical education. At the same time the two full professorships of dermatosyphilidology in the Vienna General Hospital were held by Ferdinand von Hebra (1816-1880) and Carl Ludwig Sigmund von Ilanor (1810-1883).

Austria↗
PubMed1990

[Injuries of the occipital condyles in fatal traffic accidents].

Among 600 deaths of traffic accidents we found injuries of the occipital condyles in 10 cyclists, 12 car drivers and 3 pedestrians. In most cases the collision speed ranged from 70 to 100 km/h. In 18 cases of direct head impact the more severe injury was on the opposite side, in 4 cases of indirect side impact (whiplash injury) on the same side. Most types of fractures were 12 horizontal disconnections and 4 fractures of the inner edges. In 9 cases the condyle fractures were on one side, in 16 cases on both sides.

Accidents, Traffic↗
PubMed1990

[Urolithiasis in 2,8-dihydroxyadeninuria: presentation of 3 additional cases].

To the now 17 case reports in caucasian patients of an urolithiasis in a rare purine metabolism disorder 2,8-dihydroxyadeninuria due to missing activity of adenine phosphoribosyltransferase 3 further cases are presented. Firstly, a monozygotic twin pair is afflicted (13-year-old boys). All calculi be composed of pure 2,8-DHA, except a mixed calculus in a 38-year-old man containing of 80% 2,8-DHA and 20% calcium oxalate. The actual literature is reviewed.

Adenine↗
PubMed1990

[Massive pulmonary brain tissue embolism].

A 20 year old woman with a severe head injury and rapidly increasing brain edema died 46 hours after the accident. There was clinical evidence of protracted shock and disseminated intravascular coagulation. The autopsy revealed a macro-embolization of brain tissue of the lungs with many central and intermediate lung artery branches occluded by cerebral tissue. Preconditions of the brain tissue embolism were a severe fracture of the skull including a traumatic rupture of the right sigmoid sinus, together with a local brain laceration and an extremely elevated intracranial pressure. Fibrin precipitations were prominent at the surfaces of the brain tissue emboli as well as in peripheral blood vessels of the lung; in the systemic circulation, intravascular coagulation was much less pronounced.

Accidents, Traffic↗
PubMed1990

[Experience after one year's computer-assisted determination and evaluation at the alcohol dehydrogenase laboratory].

The processing of blood alcohol measurements by alcohol dehydrogenase method (ADH) was improved by using a tailored software program. The program is written in Turbo BASIC and requires an IBM Personal Computer (PC/XT/AT) or compatible with at least 640K memory and a graphic adapter (EGA or Hercules). All features of the program are available from the menu bar with pull down menus. The program stores on disk or harddisk the optical density values measured with an HITACHI spectrophotometer. After the measurement the calculation of alcohol concentration is accomplished by the program. The results can be transferred and further handled with database systems (e.g. DBASE III). Stored values are used to calculate the reproducibility of calibration and the precision of single determinations.

Alcohol Dehydrogenase↗
PubMed1990

Amiodarone--efficacy and late potentials during long-term therapy.

This prospective study was intended to examine the influence of long-term amiodarone therapy on the parameters of the signal averaged ECG and their relation to simultaneously derived Holter monitoring data. For this purpose 27 patients with angiographically confirmed dilated cardiomyopathy or coronary heart disease and highgrade ventricular arrhythmias, in whom an average of four class I antiarrhythmic drugs had proven ineffective, were stabilized on amiodarone. Before the beginning of therapy, as well as after two months and subsequently every three months if possible, a resting ECG, a signal averaged ECG by the method of Simson and Holter monitoring were performed. Compared to the initial measurement we found a significant increase in the duration of the total filtered QRS complex, while the change in the voltage did not reach the significance level. The incidence of late potentials remained largely constant under amiodarone. In the long-term follow up Holter monitoring showed a relatively high responder rate of between 46 and 81% under amiodarone. No relation could be detected between the results of the signal averaged ECG and those of 24-h Holter monitoring.

Amiodarone↗
PubMed1990

[Sonographic assessment of gastric emptying. Reliability and validity of the antrum sagittal surface method for fluids].

The reliability and validity of sonographic measurements of gastric emptying employing sagittal antral planimetry were investigated. The intraindividual reproducibility of this procedure was examined in 15 healthy volunteers, who ingested 400 ml of water on two separate study days. Simultaneous studies of gastric emptying by ultrasound and scintigraphy were performed on 17 of 20 patients with suspected gastroparesis (16 diabetics and one patient with disseminated encephalomyelitis), using a caloric liquid test meal (20 g Biloptin-fatty meal in 300 ml water at 37 degrees C, radiolabeled with 0.5 mCi 99mTc-colloid). The expansion of the antral area with increasing amounts of ingested fluid and the emptying times showed a good intraindividual reproducibility from day to day (r = 0.94 vs. r = 0.81). There was a significant correlation between the relative residual volumes calculated by scintigraphy and by ultrasound (r = 0.82). These results imply that the ultrasonic sagittal antral area method is reliable and valid in the assessment of gastric emptying rates in humans.

Adult↗