Shedding of Mycobacterium bovis in the nasal mucus of cattle infected experimentally with tuberculosis by the intranasal and intratracheal routes.

Four groups of six calves were infected experimentally with either a low dose of approximately 10(4) colony-forming units (cfu) or a high dose of approximately 10(6) cfu of Mycobacterium bovis. Each dose was delivered by the intranasal and intratracheal routes. More severe disease was observed in the groups inoculated with the high dose. Visible lesions were identified in 21 of the 24 animals, all of which also gave positive skin tests and interferon-gamma (IFN-gamma) responses. Nasal shedding was detected in 15 of the 24 animals and the frequency of shedding was influenced by both the route and the dose of infection; no shedding was observed in the group infected intratracheally with the low dose. Two of the 15 confirmed shedders had no visible lesions at postmortem examination; both of these calves gave IFN-gamma responses but only one was skin test positive.

Mycobacterium nonchromogenicum in nasal mucus from cattle in a herd infected with bovine tuberculosis.

Skin test negative cattle from a herd containing an unusually high proportion (194/382) of tuberculin skin test positive cattle were investigated for remaining Mycobacterium bovis infected animals. Blood samples from the skin test negative cattle, analysed by an antibody ELISA and an interferon-gamma assay, were mostly test negative for M. bovis. Radiometric culture of nasal mucus samples from 48 of the cattle yielded 22 culture positives with acid-fast bacilli and cording in 6 of these. Subculture on solid media was successful for 7, including 2 with cording of the 22 radiometric culture positives. Mycobacterium tuberculosis complex DNA probe testing using the Accuprobe (Gen-Probe, Inc.) and M. tuberculosis complex-specific PCR amplification, performed on the solid media subcultures, were negative. 16S rRNA PCR and sequence analysis were successful for 6 of the 7 solid media subcultures obtained and revealed the presence of Mycobacterium nonchromogenicum in all 6 subcultures. This is the first report of M. nonchromogenicum in nasal mucus of cattle. The observation highlights the importance of integrating definitive tests such as the PCR for diagnosis of bovine tuberculosis and indicates a possible zoonotic risk.

Thyroid releasing hormone test in schizophrenic patients with post-psychotic depression.

1. TSH response to TRH was assessed in 25 patients meeting operationalized criteria for the post-psychotic depression syndrome and in an age and sex matched control group of 34 primary depressed patients. 2. A blunted TSH response was observed in 36% of the patients with post-psychotic depression. 3. The rate of blunted TSH response was similar for patients with secondary post-psychotic depression to those patients with primary depressions. 4. Demographic and clinical parameters did not distinguish those post-psychotic depressed patients who had a blunted response from those who did not. 5. A blunted TSH response to TRH did not predict which patients were more likely to have a favorable response when adjunctive imipramine was added to their on-going fluphenazine decanoate and benztropine regimen.

Adjunctive imipramine maintenance in post-psychotic depression/negative symptoms.

Fourteen schizophrenic or schizoaffective patients, who had had operationalized syndromes of post psychotic depression or negative symptoms unresponsive to adjunctive benztropine but responsive to adjunctive imipramine, completed a double-blind maintenance treatment trial of adjunctive imipramine vs. placebo. All patients were maintained on standing doses of fluphenazine decanoate and benztropine throughout. All six patients tapered to placebo relapsed into their depression-like, negative symptom state, whereas only 2 of 8 patients maintained on imipramine had such a course (p = .009, favoring imipramine maintenance). No patients maintained on imipramine relapsed into psychosis. These results suggest the advisability of maintaining adjunctive imipramine treatment, in conjunction with appropriate neuroleptic and antiparkinsonian regimens, in stable, syndromally defined, postpsychotic depressed or negative symptom patients initially responsive to adjunctive imipramine.