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Biomedical subjects

J Gosselin

Publications and source records attributed to J Gosselin.

At least 55 records · Page 3Linked to original sources

[Aneurysm of the popliteal vein].

Aneurysms of the popliteal vein are rare. They often seem to be favored by parietal dysplasia, but this is not a consistent finding. From a clinical viewpoint, the lesion is often asymptomatic. It may be detected fortuitously through the occurrence of a popliteal mass. In more severe cases, pulmonary emboli originating at the aneurysmal site will occur. As a rule, diagnosis is based on results from investigations such as phlebography and, more recently, echography which is bound to have a more important role in this field. Management must take the patient's history and background into account, depending upon which treatment will consist of either mere surveillance of asymptomatic patients, or resection possibly followed by restoration of venous circulation--placement of a caval block being restricted to very particular cases.

Aneurysm↗

Differential interleukin-2 and interferon-gamma production by human lymphocyte cultures exceptionally resistant to Epstein-Barr virus immortalization.

Epstein-Barr virus (EBV) readily immortalizes human peripheral blood lymphocytes (PBL) in vitro. However, during the past several years, we found that PBL from two exceptional EBV-seropositive healthy adult individuals were refractory to immortalization by EBV. We report here a study aimed at learning about the immunobiological features which differentiate these EBV-resistant (R) PBL from others which are susceptible (S) to EBV immortalization. Results of this investigation indicate that: (a) Following EBV infection, R-PBL produced significantly higher amounts of interferon gamma (IFN-gamma) than S-PBL. There were however no differences in regard to interferon alpha production between these two types (R and S) of EBV-infected cultures. (b) R-PBL had a maximal interleukin-2 (IL-2) production by S-PBL occurred at least 48 hr later, i.e., at Day 7. (c) The percentage of non-B cells expressing the IL-2 receptor was also higher in EBV-infected R-PBL than S-PBL. (d) In contrast, expression of IL-2 receptors after EBV infection was higher on B cells from S-PBL than on B cells from R-PBL. Interestingly, no differences were noted in regard to IL-2 receptor expression between R-PBL and S-PBL treated with mitogens (i.e., phytohemagglutinin and pokeweed mitogen). (e) Finally, using anti-IL-2 and anti-IFN-gamma antibodies in EBV-infected R-PBL cultures, we were able to obtain EBV-induced immortalization of these cultures. Taken together, these results suggest that an early IL-2 synthesis and high IFN-gamma production by EBV-infected PBL play an important role against lymphocyte immortalization by EBV.

Antigen-Antibody Reactions↗

[The history of Horton's disease or ... 10 centuries of a fascinating adventure].

In 1932, Horton, Magath and Brown reported two cases of a "new form of arteritis affecting the temporal vessels ... which probably represents a new clinical syndrome". In reality, several publications, devoted to the same pathology already preceded this article. The most ancient is that of an ophthalmologist from Baghdad, Ali Ibn Isa (940 to 1010). In his memories, translated and published in english in 1936, the author states that "he undertook excision and cauterisation of arteries to treat patients who were suffering from heat and inflammation of their temporal muscles and which sometimes ended in loss of vision ...". In 1890, J. Hutchinson, an English surgeon, reported a case "... of inflammed and swollen temporal arteries ...". This article was only brought to light in 1946. In 1930, M. Schmidt, published a probable case of temporal arteritis, subsequently reported in 1947. In 1934 and 1936, Horton published new cases of temporal arteritis and defined the clinical characteristics of the disease and its histology. In 1938, Jennings made a particular contribution in reporting the first case of blindness. From this time on, cases of temporal arteritis became increasingly common in the literature. The first French case was described by J. Paviot et al. in 1934, but remained largely unrecognized until 1942. In 1936, J. Chavany was the first to describe the pillow sign, but more particularly in 1948, he prescribed the first treatment with steroids, with spectacular results. It was only in 1950 that R.M. Shick et al. published the effects of steroid therapy in temporal arteritis.(ABSTRACT TRUNCATED AT 250 WORDS)

Bibliographies as Topic↗

Tac expression induced by Epstein-Barr virus is restricted on non-transformable B lymphocytes.

During the course of a comparative study dealing with the immortalization of lymphocytes from a large number of normal healthy donors, we found that B cells of two of these individuals could not be immortalized by Epstein-Barr virus (EBV) under the standard conditions. The expression of the Tac antigen on the membrane of EBV-infected B cells from these two donors was compared with that of B cells from EBV immortalization-susceptible ones. The method used was two-colour immunofluorescence cytofluorometer analysis. We found that the Tac antigen expression was significantly and repeatedly reduced in the case of the two immortalization-resistant donors. This difference might be related to a genetic control of the resistance to EBV-immortalization.

B-Lymphocytes↗

Stimulation of T cells and induction of interferon by toxic shock syndrome toxin 1.

Toxic shock syndrome toxin 1 (TSST-1) is a potent immunomodulating substance isolated from Staphylococcus aureus strains associated with toxic shock syndrome (TSS). Flow cytometric analysis was used to compare scatter changes in several cell-surface phenotype markers on human mononuclear cells exposed in vitro to TSST-1 or to phytohemagglutinin, a lectin with similar effects on the immune response. The results showed differences between PHA and TSST-1 in the appearance of the tested T cell subset markers and of interleukin 2 receptors. In general, the stimulation of mononuclear cells by TSST-1 was slower than that by phytohemagglutinin. TSST-1 induced the production of interferon in cultures of murine spleen cells. By means of inhibition studies with specific antibodies to interferon, the interferon produced was characterized as the gamma type. Human mononuclear cells exposed to the toxin also produced gamma interferon, with levels similar to those induced by staphylococcal enterotoxin A, a known potent interferon inducer. The induction of gamma interferon by TSST-1 may play a role in the immunosuppression caused by TSST-1.

Adult↗

Human herpesvirus 8 viral FLICE-inhibitory protein inhibits Fas-mediated apoptosis through binding and prevention of procaspase-8 maturation.

Viral FLICE-inhibitory proteins (v-FLIPs) encoded by several herpesviruses and poxviruses share the ability to inhibit apoptosis after engagement of death receptors. In the current article, we provide insights into the mechanisms by which the v-FLIP of human herpesvirus 8 (HHV-8) (also referred to as Kaposi's sarcoma-associated virus) protects cells from apoptosis after Fas-induced signaling. Using v-FLIP expression vectors, our results clearly show that HHV-8 v-FLIP reduces the cleavage of procaspase-8 into its active p18 and p10 protease subunits upon Fas-induced cell death. These results were confirmed by lower caspase-8 and caspase-3 protease activities in extracts of HeLa cells expressing HHV-8 v-FLIP. Coimmunoprecipitation studies further indicate that HHV-8 v-FLIP physically interacts with procaspase-8, but not with Fas-associated protein with death domain in the cellular cytoplasm. These results suggest that binding of HHV-8 v-FLIP to procaspase-8 affects the recruitment and the activation of the latter at the death-induced signaling complex, resulting in diminished apoptotic cascade initiation. Because cellular FLIP was recently reported to modulate promoter containing NF-kappaB motifs and that both HHV-8 and human immunodeficiency virus type 1 (HWV-1) can infect monocytes, we studied the effects of v-FLIP on HIV-1 gene expression. Cotransfection experiments indicated that v-FLIP expression is associated with activation of HIV long terminal repeats: events that were strictly dependent on the presence of NF-kappaB consensus elements. In conclusion, HHV-8 v-FLIP can possibly contribute to the pathogenesis of both HHV-8 and HIV-1 through impaired Fas-dependent killing of infected cells by cytotoxic T cells and through activation of HIV gene expression.

Amino Acid Sequence↗

[Return to work after surgical treatment of varicosities of the lower limb].

Factors which the duration of time off work after surgical treatment of venous insufficiency of the legs were studied in 3000 patients undergoing surgery in our institution between 1985 and 1990. Three variables significantly influenced return to work at 2 weeks (RW2w). The first was socio-professional group. All patients in the first was socio-professional group. All patients in the professions and 95 per cent of tradesmen or freelance workers had returned to work after 2 weeks, while 40 per cent of civil servants and 35 per cent of employees in private organisations were still off work. Time spent of work was 23 +/- 10 days in civil servants, 4 +/- 3 days in the professions and 5 +/- 2 days in tradesmen of freelance workers. The second was the type of anesthesia with or without hospitalisation, local or general. The final variable was the physical effort involved in work, the RW2w was 72 par cent in patients in whom such effort was mild or moderate, and 56 per cent in effort was considerable. The second was the type of anesthesia with or without hospitalisation, local or general. The final variable was the physical effort involved in work. The RW2w was 72 percent in patients in whom such effort was mild or moderate, and 56 per cent in effort was considerable. It is concluded that the rapidity of return to work was not as good as could legitimately be expected following an operation with nil mortality and extremely limited morbidity.(ABSTRACT TRUNCATED AT 250 WORDS)

Absenteeism↗

[The value of velocimetric investigation of the uterine arteries in retro-placental hematoma. 3 cases].

Retro-placental hematoma is a sudden event with a serious prognosis which is aggravated by the very frequent absence of premonitory clinical, biological or ultrasonic signs. Does a velocimetric investigation of the uterine arteries have any predictive value in this disorder? The apparatus used was a continuous Doppler with spectral analysis and a 4 MHz probe no ultrasonic location. Each examination involved the exploration of 2 uterine arteries and of the umbilical flow. The method of recording the uterine arteries is described. Three cases of retro-placental hematoma are reported. In these three cases, an increase in the resistance index of one of the uterine arteries (the right artery in 2 cases and the left in 1 case) was detected with the presence of a protodiastolic notch on the trace, whereas the umbilical index itself was normal and no other sign was present which could predict the placental event. The value of the Doppler recording is already established in many obstetric indications, and these should be extended yet further, particularly if this preliminary study is confirmed on a larger scale.

Adult↗

[A case of complex angiodysplasia of the lower limb. Attempted treatment by embolization].

The authors report a case of complex angiodysplasia of the right lower limb, complicated by an ulcer of the ankle, and associated with a venous dysplasia, arteriovenous fistulae, and malformations in the distal arterial system. A deliberately partial embolization of the arteriovenous communications of the right foot helped to achieve scarring of the trophic disturbance.

Adult↗