Bactericidal activity of oxacillin against beta-lactamase-hyperproducing Staphylococcus aureus.

The bactericidal activity of oxacillin against beta-lactamase-hyperproducing strains of Staphylococcus aureus for which the MIC by MicroScan was 1 or 2 micrograms/ml after incubation for 24 h was evaluated by MBC studies and kill kinetics methods. MBC and kill kinetics tests were both performed using Mueller-Hinton broth (MHB), with and without 2% NaCl supplementation, and incubation at 30 and 35 degrees C. When MBC testing was performed with salt-supplemented MHB, the oxacillin MBC/MIC ratio was greater than 8 for 17 and 16 of 17 S. aureus isolates at 30 and 35 degrees C, respectively. With unsupplemented MHB, the MBC/MIC ratio was greater than 8 for nine and six strains at 30 and 35 degrees C, respectively. Five representative strains were selected for kill kinetics studies under the four different test conditions. Oxacillin appeared more bactericidal by the kill kinetics method than by MBC testing. Moreover, salt supplementation did not affect the results of kill kinetics studies as dramatically as it did the MBC results. Thus, bactericidal testing results are markedly influenced by the technique employed, and further in vivo studies are necessary to fully evaluate the efficiency of oxacillin against beta-lactamase-hyperproducing strains of S. aureus.     

Acute transmural myocardial infarction associated with active Coxsackie virus B infection.

Out of a total of 233 patients suffering from transmural myocardial infarction, 20 patients were found to have serologic evidence of a concurrent active Coxsackie virus B infection. While the infection may have been coincidental, it is also possible that the virus may have played some part in the illness. Conceivably, myocarditis could be mistaken for infarction or, by some mechanism as yet unknown, the virus might precipitate infarction in susceptible subjects.     

Leukemia cutis treated with total skin irradiation

An infant with acute monoblastic leukemia who presented with an extramedullary mass and involvement of the bone marrow, cerebrospinal fluid, and skin is described. After achieving remission, she later developed a relapse that was isolated in the skin. Superficial electron beam irradiation to the total skin surface was administered as therapy for the relapse. She remains in remission 12 months following this treatment. The isolated nature of the skin relapse, in addition to the fact that the relapse did not involve a previously irradiated field, suggests that the skin may have harbored the leukemic cells since the time of diagnosis. Cytogenetic data is presented that lends further support to this hypothesis.     

Initiation of labor with a moderately favorable cervix: a comparison between prostaglandin E2 gel and oxytocin

This study compares prostaglandin E2 (PGE2) gel and oxytocin for the initiation of labor in term pregnancies with a moderately favorable cervix (Bishop score 5-8). Compared with a matched group, 48 cases treated with PGE2 gel (2.5 mg intravaginally) required significantly less or no oxytocin, had shorter first stages of active labor, and had no increased risk of uterine hyperstimulation or cesarean section. Initiation of labor with low dose PGE2 when the cervix is moderately favorable is less labor intensive and meets with more patient satisfaction.     

Discriminative stimulus effects of N-substituted analogs of phencyclidine in rhesus monkeys

In daily sessions of a two-lever, discrete-trial, food-reinforced procedure, rhesus monkeys were trained to discriminate between subcutaneous injections of ketamine (1.0 or 1.8 mg/kg) and control injections. In tests of stimulus generalization, cumulative doses of drugs were administered in single sessions and either control- or ketamine-appropriate responding produced food. Ketamine (1.8 and 3.2 mg/kg) and phencyclidine (0.32 mg/kg) produced an average of more than 90% ketamine-appropriate responding. In contrast, d-amphetamine, atropine, chlorpromazine, codeine, diazepam and quipazine, tested at doses up to and including those that markedly reduced response rates, produced exclusively control-appropriate responding. Dose-related ketamine-appropriate responding was produced by each of ten 1-phenylcyclohexylamines, the potencies of which varied with the length, electronegativity, and number of N-alkyl chains present. The most potent analog of phencyclidine, N-ethyl-1-phenylcyclohexylamine, was approximately equipotent with phencyclidine. These data are consistent with previous reports that the discriminative stimulus effects produced by phencyclidine are representative of a unique class of drugs, and that alkyl substitutions in the region of the piperidine ring alter the potency, but not the characteristic pharmacological activity, of the resulting analogs. The potencies of some of these analogs compared to phencyclidine in rhesus monkeys, however, differed from their relative potencies in rodents. Thus, there appear to be species differences in the role of the nitrogen pharmacophore of these compounds in producing phencyclidine-like behavioral effects.     

Adjunctive therapy in treatment for head and neck cancer.

Improvement in tumor-free intervals and cure rates of patients with cancer of the head and neck will almost certainly come from utilization of more than one type of treatment in the same patient. For example, in treatment for formidable lesions this might take the form of a short course of preoperative chemotherapy followed by surgery. Postoperative chemotherapy might then be employed in preoperative responders, with the addition of radiation according to the usual postoperative indications. Specific or nonspecific immunotherapy might be used on a long-term basis, preoperatively and postoperatively. In selected patients, utilization of multiple modalities early in a careful long-term plan may bring improvement over current results from employment of adjuvant measures only after recurrence or metastatic spread is clinically obvious.     

Myasthenia gravis-associated antibodies in asymptomatic thymoma

Serum antibodies associated with myasthenia gravis were evaluated before and after therapy in an asymptomatic patient having a malignant thymoma. The case illustrates that myasthenia-associated antibodies may also be useful as a tumor marker of thymoma in the work-up of mediastinal masses, in evaluating therapy of thymoma, and possibly in detecting recurrence of thymoma and potential for developing myasthenia gravis.