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Biomedical subjects

M R Buhl

Publications and source records attributed to M R Buhl.

At least 19 recordsLinked to original sources
PubMed1989

[Results of treatment of meningitis during a 10-year period].

A review of 131 cases of purulent meningitis is presented. The patients are mainly non-pediatric and, because of that, meningitis caused by Streptococcus pneumoniae predominates. This is the main reason for the high overall mortality of 15.6%. The main etiological cause of lethal meningitis was Streptococcus pneumoniae, and it is discussed whether chloramphenicol, previously shown to exert an antagonistic effect on beta-lactam antibiotics, contributes to the relatively high mortality. It is suggested that chloramphenicol should be withdrawn from meningitis treatment and replaced by cefuroxime.

Adult↗
PubMed1985

Urinary hypoxanthine and pseudouridine as indicators of tumor development in mesothelioma-transplanted nude mice.

A human mesothelioma was heterotransplanted to nude mice, and the urinary excretions of hypoxanthine, xanthine, pseudouridine, orotic acid, 7-methylguanine, and 1-methylhypoxanthine have been followed before and after the tumor transplantation. The compounds were measured by means of isotachophoresis, which has been found a rapid and precise method. The tumor reached maximum size within 30 days, and at this time a significantly increased excretion of pseudouridine and hypoxanthine was observed. Tumor growth was stopped by chemotherapy (vincristine, cyclophosphamide, prednisolone, and Adriamycin), and corresponding to this, a decrease occurred in both pseudouridine and hypoxanthine excretion to normal values.

Animals↗
PubMed1979

Urid acid accumulated in isolated kidney grafts: an assessment of agonal ischaemia.

Hypoxanthine-xanthine washed out from kidney tissue during preservation has previously been found to be a reliable measure of the in vitro assessment of the deleterious effect of ischaemia on the functional regenerative ability of the graft. We have now studied the question: can uric acid accumulation in the isolated kidney graft be employed as a retrospective measure of the agonal ischaemia? We have found that uric acid alone accumulates in renal tissue during the agonal phase, in an amount that remains unchanged during the subsequent in vitro ischaemia. The determination of hypoxanthine-xanthine and uric acid in kidney perfusate samples during preservation must thus be presumed to be an optimal clinical-chemical method of assessing the graft ischaemia.

Adenosine Diphosphate↗
PubMed1979

The predictive value of 5'-adenine nucleotide depletion and replenishment in ischaemic rabbit kidney tissue.

Renal ischaemia produced by clamping of the blood vessels in situ for periods of 10 to 150 minutes resulted in a progressive depletion of the total content of adenylates in the kidney tissue (sigma ATP, ADP, AMP). Initial dephosphorylation of ATP and ADP, resulting in further catabolism of AMP to hypoxanthine and xanthine, accumulated in the ischaemic tissue. The postischaemic ability of the kidney tissue to functional regeneration was in correlation with the ischaemic adenylate loss (r = +0.94, P less than 0.001) as well as the accumulation of hypoxanthine and xanthine (r = -0.90, P less than 0.001). The initial adenylate resynthesis rate was constant during recovery (0.5--0.8 mumol/g . h-1), independent of the duration of the preceding ischaemia. Determination of the postischaemic adenylate regeneration thus gave no additional prediction of the reversibility of the ischaemic parenchymal damages.

Adenosine Diphosphate↗
PubMed1976

Hypoxanthine excretion during preservation of rabbit kidneys for transplantation. An assessment of the ischaemic damage.

The loss of 5'-adenine nucleotides from kidney tissue subjected to acute ischaemia can be indirectly estimated by washing out the end product of catabolism, hypoxanthine, from the ischaemic tissue to the perfusate. As a correlation has previously been demonstrated between the duration of the previous normothermic ischaemia and the washout of hypoxanthine during preservation, hypoxanthine has been studied as a prospective measurement of ischaemic renal damage, by transplantation of rabbit kidneys. The results were compared to the already established parameters L-lactate and lactate dehydrogenase. Different ischaemic traumata and methods of preservation have been employed in order to determine the relationship of these parameters to the ischaemic kidney damage as evaluated by the functional regeneration of the grafts after autotransplantation. The wash-out of hypoxanthine was found to be correlated to such a degree to the reversibility of the ischaemic cell degeneration that a certain in vitro exclusion of the irreversibly damaged kidney grafts was possible. It is concluded that hypoxanthine can function as a reliable and sensitive measurement for the in vitro establishment of the ischaemic kidney parenchymal damage, and that it can be employed clinically with advantage.

Animals↗
PubMed1976

The postanoxic regeneration of 5'-adenosine nucleotides in rabbit kidney tissue during in vitro perfusion.

The adenylate metabolism in rabbit kidney tissue was investigated, by isolated normothermic bloodless perfusion, during anoxic cell deterioration and postanoxic recovery in vitro. The amounts of hypoxanthine washed out during continuous anaerobic perfusion were shown to represent a definite loss of intracellular purine. No salvage of the endogenic liberated oxypurine was found to occur during postanoxic reoxygenation. The ability to restore the content of 5'-adenosine nucleotides failed after 60-120 min of anaerobic perfusion. Adenosine, adenine, inosine, hypoxanthine, and D-ribose added to the perfusate during reoxygenation were investigated with regard to their ability to stimulate postanoxic adenylate regeneration. Adenosine alone added in a concentration of more than 1 mmol/l showed a significant stimulation of the adenylate synthesis, with complete regeneration of the adenylate content after 180 min of preceding anoxia. In can be concluded that anoxia kidney deterioration is associated with a progressive loss of intracellular oxypurine, and a decreasing ability to regenerate adenylates after reoxygenation, which could be prevented by exogenic addition of adenosine. It appears reasonable to assume that the results obtained reflect the adenylate metabolism of a kidney graft during the postischaemic phase immediately after implantation.

Adenine↗
PubMed1976

Oxypurine excretion during kidney preservation: an indicator of ischaemic damage.

The loss of 5'-adenine nucleotides in ischaemic kidney tissue is related to the postischaemic survival of the organ. It has previously been demonstrated that the catabolism of 5'-adenine nucleotides in ischaemic tissue can be evaluated indirectly by the washout of the final products: hypoxanthine, xanthine, and inosine. The present study indicates a relationship between postischaemic renal function and the duration of normothermic ischaemia. It further demonstrates a linear correlation between the duration of normothermic ischaemia and the quantity of hypoxanthine/xanthine recovered from the perfusate. Thus the method may be used for the evaluation of possible renal grafts.

Adenine Nucleotides↗