Disseminated infection due to Nocardia transvalensis coincident with Cryptococcus neoformans variety gattii meningitis.

A case of meningitis due to Cryptococcus neoformans var. gattii coincident with disseminated Nocardia transvalensis infection is reported. Nocardia infection initially progressed despite high-dose antimicrobial therapy. Although a specific immunologic defect could not be defined, in vitro lymphocyte proliferation in response to stimulation with the Nocardia isolate was reduced. It is proposed that coinfection with Cryptococcus neoformans may have contributed to the observed impairment of lymphocyte function, leading to disseminated Nocardia disease and a suboptimal treatment response.

Molecular cloning of genes involved in purine biosynthetic and salvage pathways of Salmonella typhimurium.

Genes have been cloned from Salmonella typhimurium which when present on the multicopy plasmid pBR322 in the E. coli strain NT31 confer a Gua+ phenotype on this strain. NT31 is a purE gpt double mutant and it was expected that a Gua+ phenotype could be conferred on it by the cloning of either gpt or purE. It was, however found that in addition to these two loci the molecular cloning of another gene, which has been identified as hpt, in pBR322 confers a Gua+ phenotype on NT31. This result is explained by the overproduction of the hpt gene product, hypoxanthine phosphoribosyl transferase, which compensates for the lack of the gpt product guanine-xanthine phosphoribosyl transferase. Restriction analysis of the three loci, gpt, hpt and purE is also presented.

Pharmacokinetics of lithium: elimination half-time, renal clearance and apparent volume of distribution in schizophrenia.

The elimination half-time and renal clearance of lithium was measured in 12 schizophrenic patients. Minimum plasma lithium concentrations during alternate dosage intervals in 5 patients increased rapidly during the first 2 to 3 days of treatment and reached a steady state level after 5 to 6 days. After the establishment of the remaining 7 patients on lithium the decline in plasma lithium concentration when treatment was stopped was monoexponential. Elimination half-times ranged from 19.3 to 41.3 hours (mean +/- SD = 28.9 +/- 7.9h) and were significantly correlated with renal creatinine clearance (p less than 0.01). Renal lithium clearances ranged from 13.5 to 36.8 ml/min (mean +/- SD = 24.4 +/- 8.0 ml/min) and the apparent volumes of distribution ranged from 0.39 to 1.39 L/kg (mean +/- SD = 0.79 +/- 0.34 L/kg). There was no evidence that the elimination parameters of lithium in schizophrenic patients were significantly different from those in healthy individuals or manic-depressive patients.

A recombination-dependent replicating instability in Salmonella typhimurium.

The aromatic amino acid-requiring mutant of Salmonella typhimurium aroD321 has a stable requirement for phenylalanine and tyrosine but is highly unstable in its requirement for tryptophan. Tryptophan requiring cells derived from this strain are themselves unstable and revert back to a requirement for only phenylalanine and tyrosine. This instability is cotransducible with the aroD region and is totally dependent on the presence of a rec+ gene in the cell. These observations are interpreted in terms of a gene duplicating and excising mechanism which is itself dependent upon the normal (rec+) recombinational ability of the cell.

Benign self-limiting sarcoidosis with skin and joint involvement.

Three cases of sarcoidosis presenting with both erythema nodosum and erythema diffusion as well as with an arthritis and pulmonary involvement are described. The simultaneous occurrence of nodose and diffuse skin lesions would suggest that a clinical distinction between Lofgren's syndrome (Lofgren, 1953) and the syndrome described by Caplan, Katz, Rubenstein (1970) is not justified.