Epidemiological study of tuberculosis in the area of Angers,France, as studied by 3 PCR-based fingerprinting methods

The new genotyping methods efficiently complement classical epidemiological investigation in order to attempt a global approach to TB control. In the present work, we have studied the genomic diversity of Mycobacterium tuberculosis isolated during the year 1998 within the district of Angers, France (260,000 inhabitants distributed in 29 districts), in order to identify recent transmission events and any related risk factors. The methods used included "spacer oligonucleotide typing" or spoligotyping, "variable number of DNA tandem repeats" or VNTR, and "double repetitive element PCR" or DRE-PCR. The resulting spoligotyping and VNTR results were also feeded to international databases and compared with >10,000 isolates for spoligotyping and 500 isolates for VNTR, representative of about 60 countries. The results obtained underlined that most of the TB cases in our setting probably reflected reactivation cases, as clustered cases indicative of potential events of recent transmission were rare. Furthermore, interrogation of international databases showed that most of the isolates from the Angers region belonged to major conserved families of TB isolates representative of Europe, with only rare cases of Asian origin, or those previously reported in specific epidemies reported from elsewhere.     

Replacement of immunoglobulin receptors by lymphocytes contained in the mouse spleen at the peak of the primary immune response

Spleen cells obtained from mice on the fifth day after injection of sheep's red cells (SRBC) irreversibly lose 50% of their surface immunoglobulin receptors during culture in vitro for 4 h. On incubation of spleen cells obtained on the ninth day after injection of the antigen no changes were observed in the total quantity of surface immunoglobulins. Metabolism of the antigen-binding receptors of immune splenic lymphocytes was studied by rosette formation. Culture of spleen cells obtained on the fifth day after injection of SRBC for 20 h showed that 70% of the rosette-forming cells (RFC) were lost. The remaining RFC belonged to -positive lymphocytes. The half-replacement time of their antigen-binding receptors was approximately 4 h. Replacement of receptors of RFC in the mouse spleen on the ninth day after antigenic stimulation takes place at the same rate. During culture of spleen cells for 20 h no decrease in the number of RFC was observed. It is postulated that the decrease in the number of RFC obtained at the peak of the primary immune response may be the result of inability of the immune lymphocytes to synthesize new receptors or the result of blocking the newly formed receptors by a soluble factor produced by immune lymphocytes during culture in vitro.N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR O. V. Baroyan.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 5, pp. 574–576, May, 1977.     

Mechanisms of polyploidization of mouse cardiomyocytes

Most ventricular cardiomyocytes in mice aged 5–6 days are polyploid cells. By this time 60% of the cardiomyocytes have become binuclear and a further 10% have become mononuclear polyploid cells. Binuclear cardiomyocytes are formed as a result of acytokinetic mitosis, mononuclear tetraploid cells as a result of termination of mitosis in the initial phases.Laboratory of Cytology, N. K. Kol'tsov Institute of Developmental Biology, Academy of Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 219–222, February, 1980.     

The involvement of glutamatergic transmission in the mechanism of movement disorders induced by reversive rotation of white mice

The ability of the selective non-competitive NMDA receptor blocker MK-801 and a series of new glutamate antagonists—the adamantane derivatives IEM-1754 and IEM-1857 and phencyclidine (IEM-1925)—to prevent movement disorders induced by reversive rotation in mice was studied. I.p. MK-801 at a dose of 0.15 ml and IEM-1754 at a dose of 5.0 mg/kg prevented the development of akinesia in response to reversive rotation, as effectively as scopolamine, a known agent which provides effective prophylaxis for movement diseases. IEM-1857, the quaternary analog of IEM-1754, was not effective. IEM-1925 significantly increased the responses of mice to reversive rotation, possibly because of its high activity in relation to other subtypes of glutamate receptors. These data provide evidence for the involvement of glutamatergic transmission in the mechanism of movement disorders of vestibular origin. Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 85, No. 4, pp. 497–501, May, 1999.     

Correlation between homovanillic acid concentration in the rat brain and sensitivity of dopamine receptors to the agonist after neuroleptic administration

Experiments on male Wistar rats showed that 6–12 h after a single injection of haloperidol in a dose of 1 mg/kg the intensity of apomorphine stereotypy increased gradually, to exceed the control level after 24 h. After injection of this neuroleptic the intensity of apomorphine stereotypy showed negative correlation with the homovanillic acid concentration in the rats' forebrain. It is suggested that the homovanillic acid concentration reflects the sensitivity of dopamine receptors to agonists.Laboratory of Psychopharmacology and Department of Pharmacology, Tartu University. (Presented by Academician of the Academy of Medical Sciences of the USSR, S. V. Anichkov). Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 6, pp. 559–560, June, 1979.