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Biomedical subjects

R J Duma

Publications and source records attributed to R J Duma.

At least 55 records · Page 3Linked to original sources
PubMed1975

Experimental pneumonitis and encephalitis caused by acanthamoeba in mice: pathogenesis and ultrastructural features.

For a more precise definition of the clinicopathological features of experimental acanthamoebic infection in mice, trophozoites of Acanthamoeba castellanii and Acanthamoeba polyphaga were instilled intranasally into adult white mice. Eight to 20 days after inoculation, severe pulmonary disease developed; one to two days later, neurological signs ensued. On pathologic examination an amebic broncho-pneumonia associated with encephalitis was found. Trophozoites and cysts were seen in lung and brain. Although Naegleria is spread by the olfactory route, cerebral lesions produced by Acanthamoeba might result principally from hematogenous carriage from the lungs. Other differences between infections caused by Naegleria and those caused by Acanthamoeba in mice also exist and serve to emphasize that when natural infections with Acanthamoeba occur, a distinct clinicopathological entity may be produced.

Amebiasis↗
PubMed1975

Therapy of cryptococcosis with a combination of flucytosine and amphotericin B.

In a prospective study from May 1971 to November 1973, 20 consecutive patients with a diagnosis of disseminated cryptococcosis were treated for six weeks with a combination of amphotericin B (20 mg daily) intravenously and flucytosine (150 mg/kg daily) orally. Fifteen patients has culturally docummented Cryptococcus neoformans meningitis, and three died of infection early in therapy. Of the remaining 12 patients, eight were alive and well eight to 34 months after therapy, and four died of other causes. None of the surviving patients has relapsed. Hematologic complications developed in nine patients, three of whom had no underlying lymphoreticular disorder or therapy with known cytotoxic agents. Renal insufficiency of mild degree occurred in only six patients. A shorter period of hospitalization and reduction in toxicity of amphotericin B suggest that combined therapy is a safe and efficacious alternative to other regimens.

Adult↗
PubMed1975

Effect of inoculum and of beta-lactamase on the anti-staphylococcal activity of thirteen penicillins and cephalosporins.

Because there are few persuasive data for selecting one semisynthetic penicillin or cephalosporin over another for treatment of serious staphylococcal infections, 118 recent clinical isolates of Staphylococcus aureus were studied to determine to what extent the presence of beta-lactamase affected the relative anti-staphylococcal activity of six penicillins and seven cephalosporins. In addition, the effect of inoculum was studied for its possible effect on the anti-staphylococcal activity of the 13 beta-lactam antibiotics. By all criteria, methicillin and nafcillin were clearly more resistant to both the inoculum effect and the production of staphylococcal beta-lactamase, whereas benzylpenicillin and cephaloridine (especially benzyl-penicillin) were the most susceptible to these effects. Cephazolin was clearly more susceptible to staphylococcal beta-lactamase and heavy inocula than the other cephalosporins (with the exception of cephaloridine), whereas cephalothin was the most resistant cephalosporin to these factors. The minimal inhibitory concentration for benzylpenicillin for tests with undiluted inoculum, compared to results with inoculum diluted 10(-4), differed by a factor up to 16,384, whereas with methicillin and nafcillin the differences were rarely more than twofold. Ratios for the other 10 antibiotics fell between these extremes. These results suggest that methicillin or nafcillin is most stable to staphylococcal beta-lactamase, and that benzylpenicillin and cephaloridine are the most susceptible.

Amidohydrolases↗
PubMed1973

Clinical and laboratory evaluation of amoxicillin (BRL 2333) in the treatment of urinary tract infections.

Amoxicillin (alpha-amino-p-hydroxybenzyl penicillin) is a new oral semisynthetic penicillin with antibacterial activity similar to that of ampicillin; however, it is more completely absorbed and urinary concentrations are higher. Twenty-seven patients during 28 episodes of urinary tract infection were treated with oral amoxicillin given either as 250- or 500-mg doses. Clinical cure or improvement occurred in 23 of 27 infections (85%); eradication of the responsible organisms occurred in 23 of 26 infections (88%); and both clinical cure or improvement and eradication occurred in 20 of 25 infections (80%). Three infections relapsed. Failure to respond bacteriologically was associated with resistant organisms in two patients and with chronic pyelonephritis (Proteus mirabilis) is one. Concentrations of amoxicillin in serum obtained 2 h after administration were more variable than those previously reported for reasons which were obscure. In vitro studies revealed amoxicillin to be comparable to ampicillin when tested against most gram-negative bacilli; however, in this situation amoxicillin may be more effective than ampicillin against enterococci.

Administration, Oral↗