Mechanism of the inhibition by RNA of the RNA polymerases of Histoplasma capsulatum.

4 S RNA isolated from the dimorphic fungus Histoplasma capsulatum inhibited the DNA-dependent RNA polymerase activity of the yeast phase of this fungus. Inhibition was specific for initiation, and resulted from binding of the RNA to the enzyme. Among a variety of synthetic polynucleotides tested, only poly(G) and oligo(dG) were effective inhibitors, suggesting a role for guanines or guanine-rich sequences of RNA in the inhibition reaction.

Aztreonam therapy for gram-negative pneumonia.

Nineteen patients with community- or hospital-acquired gram-negative pneumonia were treated with aztreonam. Other gram-negative antibiotics were withheld. Thirteen patients (68 percent) had clinical cures and 15 (79 percent) had microbiologic cures with aztreonam. No adverse reactions or drug toxicity occurred in this population.

Loa loa: ocular filariasis in an African student in Missouri.

Ocular filariasis was observed in an African student living in Missouri. The adult female Loa loa worm was seen migrating under the conjunctiva. There was 34% eosinophilia and a high microfilaremia. The patient was successfully treated with diethylcarbamazine (Hetrazan) with no appearance of allergic manifestations.

Alteration of tyrosine isoaccepting transfer ribonucleic acid species in wild-type and asporogenous strains of Bacillus subtilis.

The relative amounts of two isoacceping species of tyrosine transfer ribonucleic acid, tRNATyrI and tRNATyrII, determined from reversed phase 5 profiles of tyrosyl-tRNA, prepared from Bacillus subtilis strain W168, were growth phase and medium dependent. The growth phase-dependent alterations in the relative amounts of tRNATyr species were also demonstrated in 11 asporogenous strains of B. subtilis. The proportion of tRNA-Tyr species and the extent of the alteration in their relative amounts during the transition from the exponential to the stationary phase of growth of these strains was not directly correlated with the formation of spores by strain W168 grown in various media or the stage at which the asporogenous strains are blocked in the process of sporulation.

Preservation of the functional above knee stump following hip disarticulation by means of an Austin-Moore prosthesis.

Patients can be provided with a functional above-knee amputation stump when the tumor is not resectable. In order to do this and still remove the entire upper end of the femur a small Austin-Moore prosthesis with drill holes is inserted and enclosed in long anterior and posterior flaps. Muscle attachments are sutured into the distal stem to obtain the balance between abduction and extension of a functional stump.

Inhibition of isolated yeast and mycelial phase RNA polymerases of Histoplasma capsulatum by rifamycin derivatives.

Various derivatives of rifamycin were shown to inhibit the RNA polymerases of the yeast and mycelial phases of Histoplasma capsulatum. The relative potency of each of the derivatives against the isolated polymerases was the same as the potency of each against the viable organism. RNA polymerase PC III from the yeast phase was more susceptible to the rifamycin derivatives than yeast phase polymerases PC I and PC II and the biggest differences in susceptibility were seen with the derivative AF/ABDP (2,6-dimethyl-4-benzyl-4-demethyl-rifamycin). The susceptibility pattern of the mycelial polymerase activity was identical to the yeast polymerase PC III.

Comparison of the ribonucleic acid polymerases from both phases of Histoplasma capsulatum.

The three ribonucleic acid (RNA) polymerases (ribonucleoside triphosphate RNA nucleotidyltransferases, EC 2.7.7.6) of the two phases (yeast and mycelial) of the dimorphic fungus Histoplasma capsulatum have been purified and characterized. The corresponding enzymes from the two phases differ in sensitivity to alpha-amanitin, ion and salt requirements, temperature sensitivity, and subunit structure. This is the first case in which such qualitative differences in RNA polymerases have been demonstrated in two growth states of the same organism.

Inhibition of Histoplasma capsulatum ribonucleic acid polymerases by homologous and heterologous ribonucleic acid.

The ribonucleic acid (RNA) polymerases from the yeast phase of Histoplasma capsulatum are differentially sensitive to RNA isolated from the yeast and mycelial phases of this fungus and from Escherichia coli. Low-molecular-weight RNA from H. capsulatum was the most effective inhibitor.

Instability of vancomycin in Infusaid drug pump model 100.

The implantable Infusaid drug pump model 100 (Shiley Infusaid, Norwood, Mass.) is undergoing trials as a drug delivery system in the treatment of osteomyelitis. This study evaluated the stability of vancomycin (1 mg/ml) incubated at 37 degrees C for 4 weeks in the pump. Both bioassay and high-pressure liquid chromatography data demonstrated a loss of at least 38% of activity over 4 weeks and colloidal precipitation of vancomycin in the pump at the end of the experiment. This study suggests that vancomycin is not stable enough for use in the Infusaid drug pump model 100.

Hypocalcemia and "toxic" syndrome associated with streptococcal fasciitis.

A 35-year-old man suffered a small puncture wound of the right hand and within four days had acute fasciitis of the right upper extremity. Cultures of wound and blood grew a group A beta-hemolytic Streptococcus. Persistent hypocalcemia was recognized daily, and he died ten days after the injury in cardiac failure. Preliminary studies have shown that the organism elaborated two streptococcal pyrogenic exotoxins (SPE-C and a new exotoxin, SPE-D). It is suggested but not proven that the cause of the patient's "toxic" illness may have resulted from the action of these exotoxins.

Treatment of serious gram-negative infections with aztreonam.

Aztreonam (SQ 26,776) is the first parenteral monobactam agent to be used in patient trials. The agent has significant activity in vitro against facultative aerobic gram-negative bacteria but not against gram-positive or anaerobic bacteria. Aztreonam was used for a year to treat 106 hospitalized patients with a total of 131 documented gram-negative infections. Important exclusion criteria included granulocytopenia, hyperbilirubinemia, meningitis, patients less than 13 years of age, pregnancy, and history of anaphylaxis to penicillin. In this study of 35 men and 71 women, there were 67 cases of pyelonephritis (25% bacteremic), 19 of pneumonia (16% bacteremic), 10 of skin or soft-tissue infections, 9 cases of osteomyelitis, and 6 cases of postpartum endometritis. During the study period, 159 facultative aerobic gram-negative bacteria were tested for aztreonam susceptibility, and 144 (91%) were found to be susceptible. Eighty percent of infections were cured by both clinical and microbiological criteria and each of the other 26 infections showed clinical improvement. Eradication of the infecting organism was achieved in 89% of infections without adverse reaction or drug toxicity.