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Biomedical subjects

P Kraus

Publications and source records attributed to P Kraus.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Mechanical properties of new low viscosity bone cements--can be improved by vacuum mixing].

With the objective of improving mechanical properties by using a new catalyst, a new bone cement (Sulfix-60) and a new low-viscosity cement with added gentamycin (Allofix-G) were developed. Dynamic weakness was the major disadvantage of the older Sulfix-6 cement, especially in comparison with high-viscosity bone cement. Although static strength could be improved, investigations into improved fatigue strength and the effect of vacuum-mixing on the static and fatigue strength had yet to be carried out. To investigate fatigue stability specimens of the new bone cements were tested using loads under wet conditions until breakage or 20 million cycles. In a first series the cement was hand-mixed in a second series vacuum-mixed alone, and in a third series vacuum-mixed under pressure. Additionally, the ultimate static bending strength was investigated using the standard four-point bending test for the three series of bone cement. Vacuum-mixing brought about an improvement in the dynamic strength of Sulfix-60 from 6.3 MPa, to 9.1 MPa and for Allofix-G from 6.3 MPa to 8.2 MPa; additional pressure brought no further improvement. A 200% increased fatigue stability was detectable in comparison with the older cement. The ultimate bending strength was also significantly improved by vacuum-mixing for both bone cements.

Biomechanical Phenomena↗
PubMed1994

Paralytic ileus as a complication of atropine therapy following severe organophosphate poisoning.

A 32-year-old man presented with symptoms of severe organophosphate poisoning and required an atropine infusion for 5 weeks. We believe the development of a paralytic ileus occurred as a rare feature of atropine toxicity when other signs were masked by the underlying condition. The onset of a paralytic ileus coincided with a spontaneous increase in red cell cholinesterase levels and may be an early sign of recovery from organophosphate poisoning.

Adult↗
PubMed1993

High-dose adrenaline in adult in-hospital asystolic cardiopulmonary resuscitation: a double-blind randomised trial.

Forty intensive care unit patients requiring cardiopulmonary resuscitation were randomised to receive either the standard dose of adrenaline (1 mg every five minutes) or high-dose adrenaline (10 mg every five minutes). In the majority of patients, overwhelming sepsis was the major contributing factor leading to cardiac arrest. In this group of patients no difference could be detected in response to high-dose adrenaline compared with the standard dose. Although no side-effects were noted with this high dose of adrenaline, more investigation is required prior to its routine use in cardiopulmonary resuscitation.

Adult↗
PubMed1993

Intensive care utilisation: the Baragwanath experience.

Intensive care medicine is an expensive service whose impact on health care has been questioned. South Africa is a country undergoing rapid social and political change and the role of intensive care medicine in the health care system of this country needs to be assessed. In this paper we evaluated the quality, cost-effectiveness and utilisation of technology in the intensive care unit of Baragwanath Hospital, a hospital serving the black community of Soweto.

Adult↗
PubMed1993

Hydrocortisone and tumor necrosis factor in severe community-acquired pneumonia. A randomized controlled study.

BACKGROUND: Community-acquired pneumonia is a major cause of death in third world countries. Antimicrobial therapy may have little impact on the natural history of patients with severe pneumonia. We hypothesized that the intrapulmonary production of tumor necrosis factor-alpha (TNF-alpha) may be responsible for the progressive lung injury and shock commonly seen in patients with severe pneumonia after commencing antibiotic therapy. AIM: To investigate the effects of a single bolus of hydrocortisone on the clinical course and serum TNF-alpha levels of patients with severe community-acquired pneumonia. DESIGN: Randomized placebo-controlled study. SETTING: Multidisciplinary ICU of a tertiary care teaching hospital. PATIENTS AND METHODS: Patients with three or more British Thoracic Society criteria of severe pneumonia were studied. Patients were randomized to receive either a single dose of hydrocortisone (10 mg/kg) or placebo 30 min prior to commencing antibiotic therapy. Patients were treated with cefotaxime and other antibiotics as clinically indicated. Blood for TNF-alpha was taken at the time of hospital admission and repeated 2, 6, and 12 h after starting antibiotic therapy. RESULTS: Thirty patients were studied: 16 received placebo and 14 received hydrocortisone. The patients who received placebo tended to be sicker than the patients who received hydrocortisone. The baseline TNF-alpha value was 989 +/- 374 pg/ml in the placebo group and 827 +/- 394 pg/ml in the hydrocortisone group. In both groups of patients, the TNF-alpha levels did not change significantly with time. There was no correlation between the TNF-alpha levels and the APACHE II score, lung injury score, or outcome. The only variable that predicted outcome was the APACHE II score. CONCLUSION: Bactericidal antibiotics do not increase serum TNF-alpha levels in patients with severe pneumonia. Hydrocortisone given prior to antibiotic treatment had no effect on the serum TNF-alpha levels or the clinical course of patients with severe community-acquired pneumonia.

Adult↗
PubMed1993

Persistent bronchopleural fistula in a patient with adult respiratory distress syndrome. Treatment with pressure-controlled ventilation.

Bronchopleural fistula (BPF) continues to present a treatment problem in mechanically ventilated patients. We report a patient with a traumatic BPF, pneumonia, and adult respiratory distress syndrome (ARDS) who was successfully ventilated with pressure-controlled ventilation (PCV). This mode, by allowing the use of lower inspiratory airway pressures, may promote closure of the fistula.

Adult↗
PubMed1992

Erythropoietin in a patient following multiple trauma.

We report on a Jehovah's Witness who had severe blood loss following major trauma. The problems of her management without blood transfusion, and with the use of recombinant human erythropoietin therapy for severe anaemia, are described.

Anemia↗
PubMed1991

Vasoconstrictor effects of adrenaline in human septic shock.

In an open prospective study, adrenaline administration in ten patients with eleven episodes of septic shock was studied. Appropriate supportive therapy (antibiotics, laparotomies, parenteral alimentation, ventilation) was given as needed. Haemoglobin was kept at or about 12 g%, pulmonary capillary wedge pressure kept at approximately 15 mmHg, and cardiac index at greater than 4.5 l/min/m2. Only when systemic vascular resistance (SVR) dropped below 600 dyn. s. cm-5 was adrenaline given to raise the latter to no higher than 800 dyn. s. cm-5 and the adrenaline was titrated to this end point. Adrenaline was used at doses up to 0.47 microgram/kg/min for up to nineteen days. There was no reliable dose response curve for adrenaline: each septic insult needed different dosages. However, if high enough doses were given, SVR eventually increased. There was no deterioration in cardiac index nor further increase in pulse rate and no renal damage was demonstrated. Only one patient died in septic shock. Two others died from causes not directly related to sepsis and another two while still in hospital, but again not septic. Five patients were eventually discharged from hospital. Adrenaline can thus be used as a vasoconstrictor in septic shock without adverse effects, but initial doses have to be high and the effects measured and titrated carefully. Used this way, adrenaline provides time for the eradication of sepsis.

Adult↗
PubMed1991

Acetazolamide in the treatment of metabolic alkalosis in critically ill patients.

Metabolic alkalosis is a common acid-base disturbance in critically ill patients. In many patients correction of fluid and electrolyte status does not fully correct the metabolic derangement. In this study we examined the effect of 500 mg of intravenous acetazolamide, after correcting for fluid and electrolyte abnormalities, on the acid-base status of 30 ventilated patients. In all patients studied there was a fall of total serum bicarbonate; the mean reduction at 24 hours was 6.4 mmol/L, with a normalization of the base excess and pH. The onset of action was rapid (within 2 hours), and the maximal effect occurred at a mean of 15.5 hours, although there was wide variation. The effect of acetazolamide was still apparent at 48 hours. No adverse effects were noted. We conclude that in patients with metabolic alkalosis, once fluid and electrolyte abnormalities have been corrected, acetazolamide is an effective and safe form of therapy with a quick onset and long duration of action.

Acetazolamide↗
PubMed1990

Effects of hypolipidemic drugs nafenopin and clofibrate on phenotypic expression and cell death (apoptosis) in altered foci of rat liver.

Phenotypically altered liver foci were produced in female Wistar rats by a single dose of N-nitrosomorpholine followed by promotion with phenobarbital (PB) for 20 or 28 weeks. Then treatment was changed to either hexachlorocyclohexane (HCH), or cyproterone acetate (CPA), or nafenopin (Naf) or clofibrate (Clof), two hypolipidemic drugs. Foci were identified by a positive reaction for gamma-glutamyl-transpeptidase (GGT) and other cytological markers. HCH and CPA could substitute for PB as foci promoters; in contrast, Naf and Clof decreased expression of GGT in foci resulting in a decline of number and area of detectable foci, effects particularly pronounced with Naf. Immunohistochemical investigations of serial sections revealed that Naf also reduced expression of the altered phenotype when cytochrome P450-PB and pyruvate kinase (type L) were used as foci markers, but not when glutathione-S-transferase B (GST-B) was used. Thus, the number of foci with enhanced GST-B did not decline significantly after the change from PB to Naf treatment. Furthermore, the reduction of GGT and the decrease of foci number during Naf treatment were not associated with increased evidence of cell death by apoptosis in foci, in contrast to the situation after PB withdrawal. These findings strongly suggest that the disappearance of GGT-positive foci after Naf is due to a phenotypic change resulting in a suppression of GGT expression rather than to physical elimination of foci.

Animals↗
PubMed1989

Autosomal recessive intestinal lymphangiectasia and lymphedema, with facial anomalies and mental retardation.

We report on two male and two female relatives with intestinal lymphangiectasia; severe lymphedema of limbs, genitalia, and face; facial anomalies; seizures; mild growth retardation; and moderate mental retardation. Main facial anomalies are a flat face, flat nasal bridge, hypertelorism, small mouth, tooth anomalies, and ear defects. Their parents are consanguineous. This disorder probably is an hitherto undescribed autosomal recessive syndrome.

Abnormalities, Multiple↗
PubMed1989

The effect of R-(-)-deprenyl in de novo parkinsonian patients pretreated with levodopa and decarboxylase inhibitor correlated to depression and MHPG, HIAA and HVA levels in the cerebrospinal fluid.

1. The effectiveness and tolerability of deprenyl as an adjunct in the therapy of parkinsonism was studied in a double-blind trial comprising 30 de novo patients. 2. Two thirds of the cases that could be evaluated showed a statistically significant improvement while on adjuvant deprenyl therapy. 3. The improvements are shown in the replugging test, a subtest of the Motor Performance Test, and on the Columbia University Rating Scale. 4. There is no statistically significant correlation between improvement of motor response and depression. 5. Deprenyl seems to be less effective in patients with low contents of HIAA and HVA in the cerebrospinal fluid.

Benserazide↗