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Biomedical subjects

H Gerlach

Publications and source records attributed to H Gerlach.

At least 73 records · Page 4Linked to original sources
PubMed1993

Long-term inhalation with evaluated low doses of nitric oxide for selective improvement of oxygenation in patients with adult respiratory distress syndrome.

OBJECTIVE: To evaluate the lowest dose of inhaled nitric oxide (NO) in patients with adult respiratory distress syndrome (ARDS), which is able to improve arterial oxygenation more than 30% compared to baseline data. DESIGN: Prospective, clinical study. SETTING: Anesthesiological ICU in a university hospital. PATIENTS: 3 consecutive patients with severe ARDS according to clinical and radiological signs. INTERVENTIONS: Pressure-controlled ventilation with positive end-expiratory pressure of 8-12 cm H2O. Inhalation of NO was performed with a blender system and a Servo 300 ventilator. The lowest effective NO dose was defined by titrating the inspiratory NO dose until reaching a 30% improvement of PaO2/FiO2. This dose was used for the following continuous long-term NO inhalation; controls of efficacy by investigation of hemodynamics and blood gas exchange were performed initially and 2 times per patient after intervals of 3-5 days. MEASUREMENTS AND RESULTS: Initial NO concentrations were found to be effective at 60, 100, and 230 parts per billion (ppb). In all measurements, arterial oxygenation was found to be elevated by NO inhalation with the initially evaluated dose compared to baseline data; in parallel, the venous admixture (Qva/Qt) was reduced. The O2 delivery increased, although O2 consumption and hemodynamics did not change. In 1 patient, interruption of NO inhalation caused remarkable increase of pulmonary resistance. CONCLUSIONS: The improvement of oxygenation by NO inhalation in ARDS does not require reduction of pulmonary resistance and can be performed using low doses in the ppb range, which has to be considered as probably non-toxic.

Administration, Inhalation↗
PubMed1993

Retrospective statistical analysis of coagulation parameters after 250 liver transplantations.

Extensive transfusion of blood components as a typical feature of OLT has been described by many authors. The perioperative requirement for transfusion, however, follows a downward trend, although the indications for OLT have been extended. Functional disturbances such as hyperfibrinolysis or platelet dysfunction, demonstrated by laboratory tests, such as platelet counts, PT, aPTT, TT, fibrinogen, and ATIII are often used to direct the transfusion of blood components, although preoperative data give insight only into the insufficient function of the old liver, which will be explanted and replaced by the donor graft. We have described a retrospective statistical analysis of laboratory data, clinical data, and perioperative blood requirements from 250 liver transplantations performed in our hospital from 1988 to 1992. The OLT was performed according to the usual surgical methods using a venovenous bypass system. Intraoperatively, volume was restored with packed RBC and FFP according to hemodynamic data, hemoglobin, and diuresis; clotting data were not used as indications for blood replacement. This analysis demonstrated that neither preoperative nor intraoperative clotting parameters were able to allow a prediction of the intraoperative requirement for transfusion of blood components; these findings parallel those of previous reports. With respect to other studies showing that perioperative transfusion rates correlated with postoperative infections and mortality, we strongly suggest that perioperative clotting measures as indicators for transfusion requirement should be analyzed with caution. Whether other diagnostic methods such as TEG are useful alternatives has to be determined.

Adult↗
PubMed1993

"Goal-directed" transfusion management leads to distinct reduction of fluid requirement in liver transplantation.

Complications in patients undergoing OLT, such as hemorrhagic events, are caused not only by surgical problems but also by the profound functional disturbances arising from hepatic insufficiency, which are at least partially cured by the procedure itself. Preoperative clotting data give insight only into the dysfunction of the explanted organ. Hence, we tried to perform a standardized, "goal-directed" anesthesiologic management in the perioperative phase in OLT, following strict indications for blood replacement according to diuresis, hemoglobin level, and hemodynamic parameters. We performed 200 OLTs in 185 patients, according to usual methods. The mean intraoperative fluid requirement was 884 ml of balanced salt solution, 8.1 units of RBC, and 9.4 units of FFP. During the first 24 hours postoperatively, an average of 2.4 units of RBC and 5.6 units of FFP had to be transfused. Currently, 170 of the 185 patients (91.9%) are alive and well. Our data demonstrate that a distinct reduction of transfusion rates in OLT is possible, neglecting clotting data and improving clotting function by avoiding hemodilution.

Aprotinin↗
PubMed1993

Time-course and dose-response of nitric oxide inhalation for systemic oxygenation and pulmonary hypertension in patients with adult respiratory distress syndrome.

Inhalation of nitric oxide (NO), an endogenous vasodilator, was recently described to reduce pulmonary vascular resistance, and to improve arterial oxygenation by selective vasodilation of ventilated areas in patients with adult respiratory distress syndrome (ARDS). We describe the time-course and dose-response of initial short-term NO inhalation in 12 patients with ARDS. Enhanced oxygenation was achieved within 1-2 min after starting NO inhalation; after inhalation, baseline conditions were re-achieved within 5-8 min. Effective doses for improvement of oxygenation [baseline: PaO2 = 10.2 +/- 2.5 KPa (76.4 +/- 18.7 mmHg)] were low: ED50 was about 100 ppb--a concentration similar to the atmosphere. NO doses of more than 10 ppm [10 ppm NO: PaO2 = 17.3 +/- 3.3 KPa (129.4 +/- 25.1 mmHg)] re-worsen the arterial oxygenation. The ED50 for reduction of mean pulmonary artery pressure was 2-3 ppm. This indicates that inhalation of NO for improvement of oxygenation in severe ARDS should be performed using lower doses, with lower risk of toxic side effects.

Administration, Inhalation↗
PubMed1993

Investigations on the antibacterial effect of conifer needle oils on bacteria isolated from the feces of captive Capercaillies (Tetrao urogallus L., 1758).

In winter, free-living Capercaillies feed almost exclusively upon needles of various conifer species. An important part of the energy and protein requirements of captive Capercaillies, however, is supplied by food rich in starch and proteins. The fecal flora of captive Capercaillies is considerably different from the flora of free-living Capercaillies. Bacterial diseases are frequent in captivity. The aim of the present study is to determine whether the essential oils from conifer needles possess antibacterial properties against several bacteria, some of which are facultatively pathogenic for Capercaillies. Needles of Pinus sylvestris contain few tannins, which could be a reason for the Capercaillies' preference for these needles. The needles of Abies alba contain high amounts of tannins and essential oils, which could explain the refusal of Capercaillies to eat these needles. The antibacterial effect of commercially available essential oils on the bacteria is investigated with a filter paper disc method and in a liquid medium. The essential oils possess a bacteriostatic or a bactericidal effect against some of the tested bacteria. Feeding on natural forage plants may help prevent the colonization of the intestines by facultatively pathogenic bacteria. The authors discuss why Capercaillies, especially young birds that are to be released, should be fed with natural forage plants.

Animal Feed↗
PubMed1993

Investigations on the aerobic flora and Clostridium perfringens in fecal specimens from free-living and captive capercaillies (Tetrao urogallus L., 1758).

173 fecal specimens from captive Capercaillies and 92 fecal specimens from free-living Capercaillies were examined bacteriologically. With all specimens the bacteriological examination was limited to the aerobic bacteria which can be isolated by the usual methods and to Clostridium perfringens. The occurrence of fungi and parasites was examined as well. The present paper compares the results of these examinations. The identifiable fecal flora of free-living Capercaillies consists of few species with low colony numbers. In about half of the specimens Bacillus spp. are the main aerobic component while only a small number of the fecal specimens contain Escherichia coli and Streptococcus spp. None of the literature to date has stated that Streptococcus spp. do not belong to the autochthonous fecal or intestinal flora of an avian species. Clostridium perfringens cannot be isolated. The identifiable fecal flora of captive Capercaillies consists of many species with high colony numbers. Almost all fecal specimens contain Escherichia coli and various Bacillus spp. Streptococcus spp. can be isolated frequently, other enterobacteriaceae and Clostridium perfringens are present. The results of the examinations for fungi and parasites only differ slightly from those in wild birds.

Animals↗
PubMed1993

Inhaled nitric oxide: its effects on pulmonary circulation and airway smooth muscle cells.

Nitric oxide (NO), an endothelium-derived relaxing factor synthesized from L-arginine by the enzyme NO synthase, has been identified as an important, short-acting, endogenous vasodilator. In patients with pulmonary hypertension, inhaling a low dose of NO as a gaseous vasodilator has been shown to induce selective vasodilation in ventilated lung areas. It achieves this without the disadvantages attributed to systemically infused vasodilators e.g. systemic vasodilation and an increase in pulmonary right-to-left shunt with a consecutive fall in PaO2. Thus, inhaled NO reduces pulmonary hypertension in the severe adult respiratory distress syndrome and in persistent pulmonary hypertension of the newborn, and improves arterial oxygenation by redistributing pulmonary blood flow away from the shunt and towards areas with almost normal ventilation/perfusion ratios. The bronchodilatory effect of NO may be an alternative therapy for treating asthma and bronchospasm.

Administration, Inhalation↗
PubMed1993

Relevance of tumour necrosis factor-alpha and interleukin-1-alpha in the pathogenesis of hypoxia-related organ failure.

Tumour necrosis factor-alpha (TNF) and Interleukin-1-alpha (IL-1) are both cytokines which are known to be released by stimulated macrophages during septic events. Because of their influence on the function of the vascular endothelium, TNF and IL-1 contribute to the pathogenesis of hypoperfusion and organ dysfunction. The finding of elevated cytokine levels in patients with hypoxic organ failure, suggesting a relation between systemic oxygen supply and humoral mechanisms, led us to perform laboratory investigations on the relevance of TNF and IL-1 for the pathogenesis of hypoxia-related deterioration of the microcirculation. In vivo studies with anaesthetized rats demonstrated a synergism between hypoxaemia and endotoxaemia on the development of lethal organ failure. In vitro studies with human monocytes showed that a hypoxic atmosphere was not able to induce synthesis or release of TNF and IL-1, whereas re-oxygenation after hypoxia initiated a significant increase in TNF and IL-1 synthesis, probably mediated by oxygen radicals. Finally, experiments with human endothelial cells established that hypoxia is able to induce high affinity receptors for TNF in a time- and dose-dependent manner. These studies demonstrate that hypoxia influences humoral mechanisms which are known to contribute to the pathogenesis of vessel dysfunction, probably through a cytokine-dependent pathway of hypoxia-related organ dysfunction.

Animals↗
PubMed1992

Further investigations on Pasteurella multocida infections in feral birds injured by cats.

A total of 64 Pasteurella multocida strains (46 out of 11 different feral bird species, partly injured by cat bites, and 18 strains originating from clinically healthy cats) were biochemically differentiated. As a result, 67.4% of the strains from feral birds and 61.1% from the cats were classified as the subspecies multocida, whilst 21.7% and 27.8% were identified as the subspecies septica. The percentage of frequency for both the subspecies was of a comparable order of magnitude from the birds injured by cat bites and from cats (58.6% and 61.1%, 24.1% and 27.8% resp.), whereas the frequency from other feral birds differed considerably (82.4% and 17.6%). Maltose-positive strains were only demonstrable in birds with wounds inflicted by cats. To date, maltose-positive strains have only been obtained from one cat and one human being with an injury caused by a cat. The results of this investigation confirm the possibility of the direct transmission of Pasteurella multocida via cat bites. 19 strains from feral birds and 15 strains from cats were tested for their capability to produce toxins. The results of these tests were negative. The present paper also describes the pathologic-anatomical and histopathological lesions caused by the infection in feral birds.

Animals↗
PubMed1992

[The aerobic bacterial flora of songbird nests].

In the area around Ober- and Unterschleissheim, a medium term decrease in the singing bird population appears to be happening. Therefore, material from nesting-boxes (used for nesting or sleeping) was examined for bacterial contamination. Mainly gram positive bacteria were isolated which were considered to belong to the normal flora. The occurrence of Streptomyces spp. is described in the nesting material of Passeres probably for the first time. Enterobacteriaceae represent only a fraction of the total isolates, but are demonstrated relatively frequently in the nests of the Nuthatch (Sitta europaea) and nests of other non-identified bird spp., so that colonization of the intestinal tract with Enterobacteriaceae cannot be excluded. Surprisingly, bacteria of the aquatic habitats such as Alcaligenes, Bordetella, Aeromonas, Non-Cholera (NC)-Vibrio were isolated, although in small amounts. The occurrence of NC-Vibrio has not yet been described in singing birds. Nests with high numbers of gram negative rods were successful in most instances, therefore, there was no proof that aerobic bacteria are responsible for the decrease in the population.

Animals↗
PubMed1992

[An epidemiologic study of the value and limits of physical therapy/exercise therapy in Fontaine stage II arterial occlusive disease].

Using a questionaire the members of the German Society for Angiology (DGA) were interrogated on the use of physical training for the treatment of peripheral arterial occlusive disease; from a total of n = 431 as much as n = 156 responded, i.e. making up a response of 36%. 104 of them conduct physical training either on their own or assign patients to it (67%). In most of the institutions exclusively walking/interval training (83%) or medical exercise (74%) are performed. In most cases the training is conducted by physiotherapeutists (71%). 13% of the patients are admitted exclusively to physical training, 34% undergo combined therapy, i.e. physical training and vaso-active medication. 22% receive mere medical, 31% surgical treatment. A general evaluation on the success of the different therapies applied turned out following frequency: 1. combined therapy (medical treatment/physical training); 2. surgical procedures as a therapeutic measure; 3. physical training; 4. medical treatment. A further study performed at three ambulatory centres offering physical training were to show what kind and to which extent such training is useful. In 34% of the cases (from a total of n = 201 patients with peripheral arterial occlusive disease in state II according to Fontaine) contraindications argue against the application of physical training. From a rest of 66% as much as 36% of the patients refuse to undergo physical training the reasons of which were stated with large transport distances and time problems. The remaining rest accepts the offer, although 24% attend such training only sporadically. The results show that mainly contraindications and insufficient patient compliance account for the fact that only one third of the patients attend physical training. The results are discussed and proposals are made to improve patient compliance.

Aged↗
PubMed1992

[A rare complication of shunt therapy. Metastasis of brain tumors by cerebrospinal fluid drainage].

Shunting of cerebrospinal fluid to extracranial spaces has been a common and effective procedure for symptomatic therapy of hydrocephalus since the fifties. In 1954 the first spreading of tumor cells via a ventriculo-pleural shunt was reported. We are presenting a case of a 10 month old girl with a medulloblastoma of the lower brain stem with spreading of the intracranial tumor through a ventriculoperitoneal shunt. Further 43 cases of the world literature with shunt-associated metastasizing of brain tumors are analysed. The extraneural spreading of tumor cells through shunt tubes must be considered as a possible complication of the shunting procedure.

Cerebellar Neoplasms↗
PubMed1991

[Mycobacteriosis in the hermit ibis (Geronticus eremita)].

The present paper reports on a case of mycobacteriosis in a colony of Hermit-Ibises, in which a so far unknown serovar of Mycobacterium avium-intracellulare has been isolated. The serologic findings in the birds disagree with those of the isolate, a fact that has been mentioned in the literature several times. The hematological and clinical-chemical parameters can hardly be interpreted without knowledge of normal values. However, the high numbers of eosinophiles in the differential smears are striking. The autopsy shows the typical picture of a granulomatous inflammation. The small subserous granulomata of the intestinal wall can be found--in contrast to other birds--lying closely together. Histopathological findings indicate a certain weakness of the defense system which, together with the good state of nutrition in some of the Hermit-Ibises, is interpreted as a possible high susceptibility of this bird species to infections with Mycobacterium spp.

Animals↗
PubMed1991

[Hygienic measures against avian mycobacteriosis in the pheasantry of the Cologne Zoo].

Endemic avian tuberculosis is a constant threat to any bird collection. Controlling measures by serological tests must be supported by both euthanization of positive birds and removal of all contaminated material from the affected enclosures. Quarantine and strict hygienic measures should control reinfection. Reinfection of captive populations through wild birds is comparatively unlikely.

Animals↗
PubMed1991

Endothelium and regulation of coagulation.

Endothelial cells form the luminal vascular surface and thus have a central role in the regulation of coagulation. One important way in which endothelial cells control the clotting system is by regulating the expression of binding sites for anticoagulant and procoagulant factors on the cell surface. In the quiescent state, endothelial cells maintain blood fluidity by promoting the activity of numerous anticoagulant pathways, including the protein C/protein S pathway. After activation, as can be brought about by cytokines, the balance of endothelial properties can be tipped to favor clot formation through coordinated induction of procoagulant and suppression of anticoagulant mechanisms. Tumor necrosis factor suppresses the endothelial anticoagulant cofactor thrombomodulin and induces expression of the procoagulant cofactor tissue factor. Working in concert, these changes can allow fibrin formation to proceed in an inflamed focus but maintain blood fluidity in the surrounding area of normal vasculature. Recent studies suggest that similar changes in endothelial coagulant properties can be induced by advanced glycosylation end products, proteins modified by glucose that accumulate in the vasculature at a rapid rate in diabetic subjects, indicating the potential relevance of these mechanisms in diabetic vascular disease.

Animals↗