The superoxide dismutase inhibitor diethyldithiocarbamate has antagonistic effects on apoptosis by triggering both cytochrome c release and caspase inhibition.

Tumor necrosis factor-alpha (TNF-alpha) and etoposide both trigger a large and rapid production of reactive oxygen species (ROS) in HeLa cells. This occurs before translocations of the proapoptotic Bax and cytochrome c proteins, the loss of mitochondrial membrane potential (DeltaPsim), and apoptosis. We have used diethyldithiocarbamate (DDC), a well-known inhibitor of Cu, Zn superoxide dismutase to study the role of ROS in this system.

Caspase-9 can antagonize p53-induced apoptosis by generating a p76(Rb) truncated form of Rb.

The tumor suppressor Rb (retinoblastoma protein) is known to regulate p53-dependent apoptosis, but the mechanisms involved are unclear. In a rat fibroblast model, we previously observed that caspase inhibition potentiates p53-dependent apoptosis and prevents the Rb cleavage associated with p53 activation. These results suggested that a caspase(s) can antagonize p53-mediated apoptosis via the production of a protective Rb truncated form.

Bcl-2 can promote p53-dependent senescence versus apoptosis without affecting the G1/S transition.

With the aim to identify events involved in the determination of p53-dependent apoptosis versus growth arrest, we used rat embryo fibroblasts expressing a temperature-sensitive mutant (tsA58) of the SV40 large tumour antigen (LT). Heat-inactivation of LT leads to p53 activation and commitment to a senescent-like state (REtsA15 cell line) or apoptosis (REtsAF cell line). We report that senescence is associated with high levels of the anti-apoptotic Bcl-2 protein and a cell cycle arrest in G1 phase, whereas apoptosis is associated with low levels of Bcl-2 and a cell cycle arrest in G2 phase.

[A joint continuing medical education program for practitioners and radiologists: a positive preliminary experience].

Purpose: A common reflective continuing medical education (CME) approach has been promoted by the French National CME Association (UNAFORMEC) and French Radiologic Organizations to improve imaging prescriptions performed by general practitioners (GP) as well as their relationships with radiologists to fit the best decision resources for an optimal patient care. This new practice based CME is a multidisciplinary learning model.

Materials And Methods: A learning model that could satisfy GP and favor improved communication between them and radiologists was elaborated.

Aeromonas hydrophila adenylyl cyclase 2: a new class of adenylyl cyclases with thermophilic properties and sequence similarities to proteins from hyperthermophilic archaebacteria.

Complementation of an Escherichia coli cya mutant with a genomic library from Aeromonas hydrophila allowed isolation of clones containing two different cya genes. Whereas one of these genes (cyaA) coded for an adenylyl cyclase (AC1) belonging to the previously described class I adenylyl cyclases (ACs), the second one (cyaB) coded for a protein (AC2) that did not match any previously characterized protein when compared to protein sequence databases. In particular, it did not align with any of members of the three known classes of ACs.

Diagnostic Imaging Contribution in the Early Stages of HIV Infection of the Brain.

The neuropathology of full-blown, symptomatic AIDS, established in many large autopsy series, has been described in great detail and is now universally accepted. In contrast, the natural history of the changes occurring in the central nervous system during the earlier states of HIV-1 infection remains poorly understood. With specific regard to MR imaging, structural abnormalities have been reported early in the course of the illness, with variable incidence, making it difficult to appreciate the significance of these findings, in particular for neurologically asymptomatic individuals.

Diagnostic imaging contribution in the early stages of HIV infection of the brain.

The neuropathology of full-blown, symptomatic AIDS, established in many large autopsy series, has been described in great detail and is now universally accepted. In contrast, the natural history of the changes occurring in the central nervous system during the earlier states of HIV-1 infection remains poorly understood. With specific regard to MR imaging, structural abnormalities have been reported early in the course of the illness, with variable incidence, making it difficult to appreciate the significance of these findings, in particular for neurologically asymptomatic individuals.

Comparative analysis of the cya locus in enterobacteria and related gram-negative facultative anaerobes.

Comparison of the cya loci (cya codes for adenylyl cyclase (AC)) from a variety of phylogenetically divergent facultative anaerobic Gram-negative bacteria reveals conserved sequence features. The entire locus structure in enterobacteria is preserved, including two major promoters (a conserved cya strong promoter, P2, and a divergent promoter for a heme biosynthetic operon, hemCD) present in the upstream region of the cya gene. The region between hemC and cya is much longer in Proteus mirabilis than in other enterobacteria, and lacks the P1 upstream cya promoter.

[Primary non-Hodgkin's lymphomas of the liver in human immunodeficiency virus infected patients. Three cases].

The occurrence of primary non Hodgkin's lymphoma of the liver has rarely been reported in patients with the human immunodeficiency virus infection. We report 3 cases in these patients, presenting with a single liver tumor in 2 cases and multiple tumors in one case. Diagnosis was made by guided-biopsy.

[The epidemiology of cerebral lymphoma in AIDS].

Cerebral lymphomas are one of the complications of AIDS. Their increasing frequency, especially in the last decade, has to be correlated with the incidence of systemic lymphomas and especially central nervous system (CNS) lymphomas in non immuno-compromised patients. CNS involvement is found in 40% of systemic lymphomas.

[The epidemiology and cost of AIDS in France].

Throughout the world the AIDS epidemic continues and even seems to accelerate in regions previously thought to be untouched. The number of cases has increased by 60% in one year. With its 15,000 seropositive persons and 35,000 cases of declared AIDS, France is the most affected of all European countries.

[Prevention of Pneumocystis carinii pneumonia associated with HIV infection using pentamidine aerosols. Retrospective study of 465 cases].

Objectives: At least 80% of human immunodeficiency virus (HIV)-positive patients not given prophylaxis therapy against Pneumocystis carinii develop pneumonia, a major cause of morbidity and mortality. We therefore retrospectively evaluated prophylaxis protocols given from March 1988 to July 1991 at the Pasteur Institute Hospital.

Methods: Pentamidine aerosols were prescribed for 456 HIV-positive patients as primary or secondary prophylaxis.

Transcriptional activity in 3T3, F9, and PCC4 embryonal carcinoma cells: a systematic deletion and linker-scanning study of the polyomavirus enhancer.

The polyomavirus (PyV) genome is not expressed in undifferentiated embryonal carcinoma (EC) cells such as PCC4 or F9 EC cells. All the viral mutants that have been selected for their expression in these cells harbor mutations or rearrangements within a region which is important for early and late transcription (as transcriptional enhancer) as well as for viral DNA replication. We have studied the role of the different parts of this enhancer on the transcription driven by early PyV promoter.

[Early involvement of the central nervous system in HIV infection: screening by MRI (a 5-year follow-up)].

A cohort of 50 initially asymptomatic seropositive patients have been followed for five years. Various clinical evolution have been observed: 21 remain stable, 29 underwent complications that take then to AIDS, 11 died. In any case, invariability of the MRI anomalies seems had to be imputed to primary infection scars.

[Lung abscess caused by Rhodococcus (Corynebacterium) equi in HIV infection. Two cases].

Rhodococcus (Corynebacterium) equi is a well-known Gram positive bacillus which is usually pathogenic in farm animals but rarely causes diseases in humans. Only 30 cases of human infection have been reported in the literature. R.

Dipeptidyl peptidase IV (CD 26) gene expression in enterocyte-like colon cancer cell lines HT-29 and Caco-2. Cloning of the complete human coding sequence and changes of dipeptidyl peptidase IV mRNA levels during cell differentiation.

A cDNA (DPCR1) specific for human intestinal dipeptidyl peptidase IV (DPP IV) has been isolated. This 1.7-kilobase cDNA, together with a previously published partial sequence, covers the entire open reading frame of human DPP IV plus 67 base pairs of the 3'-untranslated end.

Severe encephalitis resulting from coinfections with HIV and JC virus.

We observed 3 cases of progressive multifocal leukoencephalopathy (PML) among frozen CNS samples obtained at autopsy from 102 adult AIDS patients. In 2 patients, PML was associated with severe HIV encephalitis. In those 2 cases, the areas of extensive JC-induced demyelination were massively infiltrated by HIV infected macrophages/microglial cells with evidence for localized increase of HIV encephalitis in PML lesions.

Spinal cord lesions in the acquired immune deficiency syndrome (AIDS).

Spinal cord involvement in AIDS is not uncommon. Different types of lesions corresponding to varying pathogenetic mechanisms have been reported. Vacuolar myelopathy is the most frequently found.

MRI pattern of progressive multifocal leukoencephalopathy (PML) in AIDS. Pathological correlations.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease which occurs in immunodepressed subjects and is particularly frequent in AIDS. Some authors having drawn attention to the protean aspect of the disease and claimed that AIDS may lose its basic characteristics and affect the grey matter as well as the white matter, we reviewed a series of 8 patients who had been biopsied and/or autopsied and had been examined at least once by MRI. In this series, contrary to what is regularly observed in toxoplasmic abscesses we did not find any lesion of the grey matter or any mass effect.

Post-pneumonectomy evaluation of the chest: a prospective comparative study of MRI with CT.

A comparative study of 11 pneumonectomized patients was undertaken in order to evaluate the respective advantages and drawbacks of MRI and CT in post-operative follow-up. Nine patients were healthy at the time of the study and two presented with tumor recurrence. MR examination included 500/40 ms axial, and frontal 800/40-80 ms or 1300/60-120 ms nongated spin echo sequences.

[Cerebral MRI in the study of prognostic factors in AIDS. Hypotheses from tests on 15 patients].

In an attempt to determine factors of predictive value in HIV (human immuno-deficiency virus) seropositive patients, particular attention was payed to symptoms indicating early involvement of the central nervous system (CNS). A cohort of healthy carriers was thus constituted. Follow-up will be carried out every six month including clinical, biological as well as CNS imaging by NMR.

[Magnetic resonance imaging: early detection of involvement of the central nervous system in acquired immunodeficiency syndrome].

Central Nervous System (CNS) involvement, whether primary by the Human Immunodeficiency Virus--HIV--itself, or secondary (toxoplasmosis or lymphoma) is remarkably frequent in AIDS, in 40 to 70% of cases, depending upon the author. In order to study the natural history of this illness, a cohort of 25 asymptomatic seropositive patients have been established. Every 6 months these patients undergo biological and clinical examinations, as well as Magnetic Resonance brain scans.

[Double ureter with one blind branch (author's transl)].

The authors report the 22nd case of double ureter to be published in the literature, in which one ureteral branch had a blind ending and did not terminate in any parenchyma. The condition was discovered during on antireflux operation for reflux in the lower pelvis of one Kidney which was known to be duplicated, and reflux in an apparently single contralateral pelvis. The pathological implications of this blind ureter are not well defined.