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Biomedical subjects

M Neumann

Publications and source records attributed to M Neumann.

At least 55 records · Page 3Linked to original sources
PubMed1990

[The course of extravascular lung water in severely injured patients in intensive care with and without thoracic trauma].

In patients with multiple injuries, the development of permeability edema can be assumed. However, no uniform shape of this fluid accumulation can be found even in the presence of severe injuries. Based on the first clinical observations, our aim was to search for correlations between the development of extravascular lung water (EVLW) and the individual injury pattern in severely traumatized ICU patients. PATIENTS and METHODS. Our investigations were performed in 48 artificially ventilated ICU patients. According to the prevailing injury pattern patients were divided into three groups: group A: 18 patients (mean age: 32 years, mean Injury Severity Score (ISS) = 29) with isolated thoracic trauma; group B: 10 patients (mean age: 27 years, mean ISS = 42) with severe multiple trauma but without any thoracic injury; group C: 20 patients (mean age: 33 years, mean ISS = 43) with severe multiple trauma and concomitant thoracic trauma. In all patients (group A, B, C), EVLW was determined by means of a double indicator method on a daily basis from the patient's admission to the ICU (day of trauma) until day 10. Additionally, the hemodynamic parameters (heart rate, mean arterial pressure, mean pulmonary arterial pressure, pulmonary capillary wedge pressure and cardiac index) were determined at the same time. RESULTS. As shown in Fig 1, EVLW was slightly elevated on day 1. However, on day 2 EVLW decreased within normal values and remained in that range until the end of the observation period. On day 3 a slight and fleeting increase of EVLW, but within normal range, can be seen. In group B (Fig.2), EVLW can be observed within normal range within a period of 4 days. Starting from day 5 until day 7 a marked increase (p greater than 0.01) in EVLW can be seen. From that maximum point EVLW development reverses slightly until day 10--however, without returning to the normal range. In group C, a marked biphasic pattern can be seen due to EVLW maximum values on post-traumatic days 3 and 7. However, in this group the EVLW was in the pathological range during the whole observation period. No statistically significant differences could be seen, when looking at hemodynamic variables. CONCLUSION. Isolated thoracic trauma will not lead to a marked pathological elevation of EVLW within the lungs. Moreover, EVLW decreases rapidly within a short time period. Based on our results, it seems that severe extrathoracic injuries will intensify microvascular injury in the initial period, as shown in our patients in group C. Increase of EVLW at a later time (day 7), as observed in groups B and C, is possibly the expression of a mediator and activator-induced "septiformal" injury of the microvascular endothelium. This may be caused by the underlying massive peripheral soft-tissue trauma. Specific elevations of EVLW subsequent to the individual injury pattern can indicate that that process has begun and is responsible for the origin of the microvascular injuries.

Adolescent↗
PubMed1990

[Myoglobin release and renal function in polytraumatized patients in intensive care].

The excessive release of myoglobin following extensive skeletal muscle trauma, burns, and myopathies may result in renal dysfunction. Due to its molecular size, myoglobin is filtered through the glomerulus and is in part reabsorbed by the tubular system. intraluminal deposition of myoglobin following renal hypoperfusion and the impact of endogenous mediators on cell function contribute to the pathogenesis of acute renal failure. The present study was aimed to investigate the relation between myoglobin and renal function in polytraumatized patients. Thirty-four patients with an Injury Severity Score (ISS) of 28 +/- 3.1 (SEM) and a mean age of 39.5 years (range 18-70) were studied prospectively. Myoglobin, sodium, and creatinine concentrations in plasma and urine were determined 8-hourly. Myoglobin excretion, fractional myoglobin excretion, myoglobin clearance, creatinine clearance, and fractional excretion of sodium were calculated. The mean concentration of plasma myoglobin on the 1st day post-trauma was 3087 ng/ml. A continuous decrease in plasma myoglobin concentration could be observed, with a mean value of 497 ng/ml on day 7. The myoglobin concentration in urine showed marked fluctuations: the mean values were 3.37-4.12 mg/ml on day 1 and 0.78-1.34 mg/ml on day 7. There was no correlation between plasma and urine myoglobin concentrations. The myoglobin concentration increased during the period of observation, but there was no correlation with the creatinine clearance. The fractional excretion of myoglobin was in the range of 1% to 14%. There was no correlation between the fractional excretions of myoglobin and sodium.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Proton-mediated liberation of aldophosphamide from a nontoxic prodrug: a strategy for tumor-selective activation of cytocidal drugs.

Based on the findings that the pH in malignant tumors can be preferentially decreased by stimulation of their aerobic glycolysis, acid-sensible prodrugs, which are nearly nontoxic at physiological pH, were synthesized. At lower pH, however, these compounds are cleaved with liberation of a cytotoxic species. The prototypic drug compound 2-hexenopyranoside of aldophosphamide was prepared, which releases aldophosphamide by acid-catalyzed hydrolysis. Exposure of cultured M1R rat mammary carcinoma cells to this agent at pH 7.4 only resulted in slight toxicity. However, when drug treatment was performed at pH 6.2, the mean pH in malignant tumors of hyperglycemic hosts, the colony-forming fraction of M1R cells decreased to 0.05 and 0.0001 of controls treated at pH 7.4 after exposure for 24 h and 48 h, respectively. The synthesis of the 2-hexenopyranoside of aldophosphamide is described in detail.

Animals↗
PubMed1989

Size and density of glial and neuronal cells within the cerebral neocortex of various insectivorian species.

Morphometric measurements were done on frontal sections through the somatosensory neocortex of various insectivorian species. All measured parameters varied with the size of animals; there was a better correlation with the ventriculartopial brain wall thickness than with the brain weight. The following rules were evaluated: with increasing brain wall thickness, 1) lamina I becomes thinner; 2) the nuclei of both neuronal and glial cells become larger; 3) the volume density of neuronal cells decreases greatly; 4) the volume density of glial cells increases slightly; and 5) as a result, the glia:neuron index increases markedly. There was no equal number of neurons under a unit surface area in the cortices of any species studied. Developmental processes that might account for the above-mentioned rules are discussed in this report.

Animals↗
PubMed1989

Stimulation of human neutrophilic granulocytes by two monocyte-derived cytokines.

Human monocytes upon stimulation with bacterial lipopolysaccharide release two cytokines which modulate the functions of neutrophilic granulocytes (PMN), a monocyte-derived chemotaxin (MOC) and tumor necrosis factor (TNF). Both cytokines stimulated the adherence of PMN on protein-coated nylon-fibers. Whereas MOC is one of the four most potent chemoattractants known, TNF was a most powerful inhibitor of PMN chemotactic migration towards several chemotactic factors including MOC. Neither cytokine stimulated the release of superoxide anion (O2-) or hydrogen peroxide (H2O2) from PMN in suspension. However, TNF, but not MOC, caused the release of considerable amounts of H2O2 and O2- from PMN attached to nylon fibers. The two cytokines have similar effects on the adherence, opposing effects on chemotactic migration and different effects on the oxidative burst of PMN.

Biological Factors↗
PubMed1989

The effect of adherence on the generation of reactive oxygen species by human neutrophilic granulocytes.

Human neutrophilic granulocytes (PMN) suspended in protein containing salt solution or adherent on protein coated nylon fibers were tested for the production of H2O2 and O2- in response to various PMN stimulants. Upon stimulation with the chemotactic factors formyl-methionyl-leucyl-phenylalanine, C5a and platelet activating factor, the non-chemotactic ionophore A23187, and the chemotaxis inhibitors tumor necrosis factor (TNF alpha) and lymphotoxin (TNF beta) adherent PMN produced considerably more reactive oxygen metabolites than suspended cells. The relative amounts of the two metabolites varied with the stimulus and its concentration, TNF alpha and TNF beta favoring H2O2 production, C5a eliciting more O2- than H2O2 and the other active stimulants being in between. Leukotriene B4 and a novel monocyte-derived chemotaxin were inactive in releasing either oxygen derivative from adherent or suspended PMN. The data indicate that attachment of PMN to endothelial cells or to connective tissue substances can strongly enhance its ability to respond to a given stimulus with the production of reactive oxygen metabolites. The findings may in part explain the "priming" phenomenon since many PMN-priming mediators increase the cells' adherence.

Calcimycin↗
PubMed1989

The dangerous psychiatric patient. Part III: Long-term treatment and management and responsibility considerations.

Physicians from various medical specialties have the opportunity to encounter once in a while a dangerous psychiatric patient, an encounter which in many cases generates confusion and embarrassment. An attempt is made to identify the typical characteristics of such a patient, and to give some practical guidance to the physician 'in the field'. A number of examples of management of dangerous or even violent patients is presented. The objective of this contribution is to increase awareness of this issue, even among non-psychiatric medical personnel. Part III deals with long-term treatment and management of dangerous psychiatric patients and responsibility issues.

Commitment of Persons with Psychiatric Disorders↗
PubMed1989

The dangerous psychiatric patient. Part I: Epidemiology, etiology, prediction.

Physicians from various medical specialties have the opportunity to encounter once in a while a dangerous psychiatric patient, an encounter which in many cases generates confusion and embarrassment. An attempt is made to identify the typical characteristics of such a patient and to give some practical guidance to the physician "in the field'. A number of examples of the management of dangerous or even violent patients is presented. The objective of this contribution is to increase awareness of this issue, even among non-psychiatric medical personnel. Part I deals with epidemiology, etiology and prediction of dangerousness.

Chronic Disease↗
PubMed1989

[Comparative studies of the acid-base status in venous, capillary and mixed blood from the ear of the dog].

Ten experimental dogs were tested in twelve experimental arrangements, with a view to finding out the extent to which results of acid-base determination or blood gas analysis could be significantly affected by induced hyperaemia of the ear or by the choice of a site for blood collection, including puncture of an ear vein. No difference was secured. Hence, ear vein puncture may be used to collect so-called capillary blood. Reference is made to the author's own values for use as criteria.

Acid-Base Equilibrium↗
PubMed1988

Community psychiatric rehabilitation in Israel.

This paper describes the development of community-based rehabilitation services for persons with mental illness in Israel. It describes current provision for occupational, social and residential programs. It is argued that developments in all of these spheres have been both slow and piecemeal, and that they have been influenced unduly by models imported from psychiatric hospitals. The authors conclude that more adequate provision is needed, and that this should be more attuned to the philosophy and objectives of community psychiatry.

Community Mental Health Services↗
PubMed1988

New bacteriophages active on strains of Hyphomicrobium.

Fifty-five lytic bacteriophages isolated from water and soil samples were active on many strains of the genus Hyphomicrobium. The optimal isolation procedure was an adsorption method in which samples from a habitat similar to that of the respective host bacterium were used as the phage inoculum. According to the morphology and nucleic acid type these bacteriophages belonged to different families: Myoviridae (type A1: five phages); Styloviridae (type B1: 33 phages; type B2: eight phages) and Podoviridae (type C1: nine phages). The Styloviridae (type B1) appeared in two morphological variants (tails flexible or rigid). All phages investigated were specific for the genus Hyphomicrobium and were unable to lyse members of other genera of hyphal, budding bacteria (e.g. Hyphomonas, Pedomicrobium, genus D, genus T). The host specificity of 42 phages was tested with 156 Hyphomicrobium strains: 122 strains were lysed by at least one of these phages, but 34 Hyphomicrobium strains were not susceptible. Morphotype B1 phages with identical morphology could be distinguished according to their host-range properties on prophage-containing Hyphomicrobium strains. With regard to differences in morphology and host range, 25 phages were selected for more detailed investigations. From these phages DNA was isolated; the melting transition midpoints (Tm) ranged from 67 to 93 degrees C. The upper and higher values suggested the presence of DNA modifications. Six different adsorption patterns could be distinguished among the Hyphomicrobium phages. Preferred attachment sites were the proximal pole of the mother cell, the hyphal tip, the distal pole of the bud, and the distal pole of the swarmer cell.

Bacteria↗
PubMed1988

[Lung function findings in workers in the rubber industry].

Chronic obstructive lung disease is common in workers in the rubber industry. Because of the close relation between hyperreactivity of the airways (HR) and the annual decline in FEV1 we measured HR in 89 healthy workers of a big rubber plant. Three groups were formed (control, latex production, rubber production). The prevalence of HR was that of a healthy general population (PC 20 FEV1 less than 0.2% Methacholin in 3 cases). In the lower Methacholin range a separation between all groups was possible.

Adult↗