The luteinizing hormone-releasing hormone pathways in rhesus (Macaca mulatta) and pigtailed (Macaca nemestrina) monkeys: New observations on thick,unembedded sections

Immunocytochemical procedures on thick, unembedded tissue sections were used to study the localization of LHRH neurons and fibers in the diencephalon and mesencephalon of rhesus and pigtailed macaques. Cell bodies were visualized in large numbers. Much of their dendritic arborization was also filled with reaction product. Cell bodies were present in the preoptic area, the periventricular hypothalamic zone from the level of the anterior hypothalamus to the premammillary nuclei, the infundibular nucleus, supraoptic nucleus, several septal nuclei, the nervus terminalis, and the amygdala. The localization of LHRH cells in several of these areas represents new observations. LHRH axons were observed to innervate the portal vessels in the median eminence, the organum vasculosum of the lamina terminalis, the medial mammillary nuclei, the epithalamus, and the amygdala. These observations are discussed in relationship to the regulation of gonadotropin secretion in the primate.     

Relation between myelin area and axon diameter in the aortic depressor nerve of spontaneously hypertensive rats

The hypothesis that the aortic depressor nerve (ADN) from spontaneously hypertensive rats (SHR) does not show the expected correlation between myelin sheath area and the axonal diameter of myelinated fibers detected in normotensive rat myelinated fibers was tested by means of regression analysis. Proximal and distal segments of ADN from 13 normotensive Wistar-Kyoto rats (WKY) and nine SHR were prepared for light microscopy study. With an image analysis system, the area of the myelin sheath and the axonal diameter of all myelinated fibers in each nerve were automatically measured. Regression lines were calculated for all nerve segments from each group. Differences between the regression lines were tested for slope and intercept and differences between the correlation coefficients were also tested. Regression lines for WKY data showed no differences between the proximal and distal segments either for slope or intercept. Proximal and distal SHR regression lines were not coincident between segments or when compared to WKY data. These results agree with previous observations that there are morphological differences between WKY and SHR myelinated fibers of the ADN suggesting that the SHR depressor nerve fibers present characteristics of axonal atrophy and/or remyelination.     

Tuberculosis, a re-emergent disease

Tuberculosis (TB) remains a major cause of morbidity and mortality worldwide. In Western Europe, regions with a high incidence of TB usually also have a high incidence of HIV infection; TB and HIV co-infection have increased over the past decade and among HIV infected patients, nearly half also develop TB. In settings where HIV is prevalent, TB drug resistance has also increased and several reports of TB and multi-drug resistant TB outbreaks, especially in health care settings, raise serious concerns about nosocomial transmission. Further research and new developments into more rapid diagnostic methods and sensitivity testing as well as the development of new anti-TB drugs are important to fight the disease. In addition, public health infrastructures have to be strengthened in order to increase adherence to TB treatment, where directly observed treatment strategy is the cornerstone for a successful outcome.     

HIV Infection and non-tuberculous mycobacteria: how important in southern European countries?

Non-tuberculous mycobacteria are considered important opportunistic infections in HIV-infected patients. In a large south-European HIV centre only 10 patients had non-tuberculous mycobacterial infection over a 5-y period. The importance of these infections in some areas, the usefulness of prophylaxis or routine use of mycobacterial blood cultures, may have to be re-considered.     

Control of organ transplant-associated graft-versus-host disease by activated host lymphocyte infusions

BACKGROUND: Prolonged persistence of donor-derived T cells after organ transplantation has been proposed to improve long-term allograft survival. However, surviving transplant-derived T cells are also able to mediate devastating graft-versus-host disease (GvHD). Currently, GvHD after organ transplantation is usually refractory to conventional therapy and the disease outcome fatal. METHODS: Graft-reactive host T cells were generated ex vivo from a patient suffering from a severe and refractory liver-transplant-associated GvHD. To control GvHD, activated alloreactive host T cells were repetitively retransferred into the patient (activated host lymphocyte infusion [aHLI]). RESULTS: Adoptive transfer of ex vivo activated alloreactive host T cells (aHLI) led to the control and complete resolution of severe GvHD without inducing allograft rejection. CONCLUSIONS: aHLI opens a novel therapeutic window to control solid-organ transplant-associated GvHD while preserving allograft integrity.     

Non-toxigenic pattern II and III Bacteroides fragilis strains: coexistence in the same host

Diarrhoeic stool samples from 334 0-5-year-old children were analysed with respect to the incidence of Bacteroides fragilis as well as other enteropathogens. B. fragilis was recovered in 9.3% (31/334) of the samples, and 79 strains were examined for the presence of the bft gene or the BfPAI flanking region using polymerase chain reaction assays. No enterotoxigenic B. fragilis strains were detected. In 29% (9/31) of the samples the coexistence of both II and III non-toxigenic B. fragilis (NTBF) patterns could be seen. In 51.6% (16/31) of the samples there existed a pattern II NTBF only, and in 19.4% (6/31) only pattern III could be detected. Strains from the same patient representing different patterns were submitted to pulsed-field gel electrophoresis assays. Fingerprints obtained by this technique showed that there was strong heterogeneity among strains from different individuals. However, different patterns from the same individual shared 100% similarity.     

NMDA receptor antagonism blocks the cardiovascular responses to microinjection of trans-ACPD into the NTS of awake rats

The possible interaction of glutamatergic metabotropic agonists and N-methyl- d -aspartate (NMDA) receptors was investigated in the nucleus tractus solitarii (NTS) of awake rats. The cardiovascular responses to unilateral microinjection of trans -1-amino-1,3-cyclopentanediocarboxylic acid ( trans -ACPD; 250 pmol/50 nL) into the NTS ( n = 8) produced hypotension (−64 ± 4 mmHg) and bradycardic (−206 ± 11 bpm) responses, which were blocked by previous microinjection of 2-amino-5-phosphonovaleric acid (AP-5; 10 nmol/50 nL), a selective antagonist of NMDA ionotropic receptors, into the same site. Intravenous injection of methyl-atropine blocked both the bradycardic and hypotensive responses to microinjection of trans -ACPD into the NTS, indicating that the hypotension was secondary to the intense bradycardic response. The data also showed that the bradycardic and hypotensive responses to microinjection of an NMDA agonist (10 pmol/50 nL) into the NTS were not affected by previous microinjection of α-methyl-4-carboxyphenylglycine (MCPG; 5 nmol/50 nL), a non-selective antagonist of metabotropic receptors. The results showing that the cardiovascular responses to microinjection of trans -ACPD into the NTS were blocked by AP-5 indicate that the responses to metabotropic agonists in the NTS involves NMDA receptors.