Biomedical subjects
Publications and source records attributed to J C Simon.
Experienced clinicians were interviewed to explore the criteria utilized in intentional therapist self-disclosure. Three themes emerged: the psychotherapy relationship, therapist self-awareness, and most significant, theoretical orientation. Five categories of criteria were identified: modeling, fostering the therapeutic alliance, validating reality, encouraging the patient's autonomy, and the therapist's satisfaction.
One case of traumatic aortic valve regurgitation operated upon is reported, and published cases of cardiac valve regurgitation caused by non-penetrating traumas are reviewed. This study demonstrates the relatively high frequency of traumatic heart diseases and among these, valve lesions. The dynamic disturbance occurs suddenly in a heart that is usually healthy and therefore without adaptation mechanism. This explains why such lesions are poorly tolerated and accounts for some peculiarities of semiology and haemodynamics. Plastic surgery seems to be successful in mitral valve lesions, whereas lesions of the aortic valve are such that valve replacement is required. The same applies to the tricuspid valve. The medico-legal aspects of the subject are mentioned.
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Knowledge of changes in patients' symptoms during hospitalization is crucial in planning treatment for acute psychotic exacerbation of chronic schizophrenia. Biweekly assessment of symptoms in 44 schizophrenic patients during the first 4 weeks of hospitalization showed that rapid recovery from psychotic symptoms occurred early in hospitalization; recovery from depression and anxiety was less complete. The rapid recovery in the first few weeks of hospital treatment supports the use of brief hospitalization for psychotic relapse. It is important to focus follow-up treatment on patients' relative lack of recovery in the hospital from depression and anxiety.
Because of neuroleptics' potential long-term side effects, the authors conducted a pilot study of an alternative to maintenance medication for stable schizophrenic outpatients. The doses of 19 patients were gradually reduced to zero over 8 weeks, and medication was then given only when a patient experienced early signs of relapse. The patients attended weekly group therapy and were closely monitored for prodromal signs, especially at times of stress; significant others helped observe patients. Five patients experienced increased symptoms during the drug washout period and were dropped from the study; of the remaining 14, 10 remained stable on the intermittent medication protocol.
The treatment of hemorrhoids by cryosurgery is fairly new. Cryogenic hemorrhoidectomy, a painless technique, can be performed on an ambulatory basis without anesthesia or hospitalisation. Using a nitrous oxide cryoprobe operating at -90 degrees C 65 cases (34 women and 31 men) are subjected to the minor treatment of hemorrhoids by cryotherapy. Although the maximum follow-up is only 14 months, so far the first results have been encouraging. Of the 10 bad results (15%), 4 have been cured by a repeated cryosurgery.
A thrombosis of the axillary artery was discovered in a 36 year old man, four days after electrocution. It was treated successfully by venous bypass. The case was then compared with five similar cases in the literature. The damaged arteries were situated in the area crossed by the electric current. The artery was normal above and below the thrombosis. The thrombosis was accompanied by parietal lesions. The development of the collateral circulation explains the absence of signs of acute ischemia. The pathogenic medico-legal and therapeutic aspects of these thromboses by electrocution are then discussed.
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Exposure to UVB results in the isomerization of trans-urocanic acid (UCA), localized in the stratum corneum, to cis-UCA. Cis-UCA can mediate at least some of the immunosuppressive effects of UVB, though the mechanism of cis-UCA action remains incompletely defined. Alterations in Langerhans cells, and other dendritic antigen presenting cell populations in the skin, may contribute to the loss of skin immune function following UVB exposure. Hence, this study was designed to investigate whether cis-UCA directly can induce changes in the immunostimulatory capacity of dendritic cells (DC) and the development of DC from precursor cells. Murine DC were generated from C57BL/6 bone marrow (BM) using granulocyte-macrophage colony-stimulating factor (GM-CSF), and were used as stimulator cells in mixed lymphocyte reactions (MLR) using BALB/c lymph node cells (LNC) as responders. The addition of cis- and trans-UCA at concentrations ranging from 0.1-500 micrograms/ml to the MLR did not affect proliferative responses. Cis- or trans-UCA (100 micrograms/ml) was added to GM-CSF stimulated mouse BM cells on day 0, day 3 or day 5 of culture, and the phenotype and allo-stimulatory function of the DC were analysed on day 7. Treatment with cis- or trans-UCA did not affect the numbers or the viability of cells in the BM cultures. In addition, the expression on DC of Iab, CD11c or the costimulatory molecules ICAM-1, B7-1, B7-2 and CD40 was not altered by the addition of cis-UCA to BM cultures. The inability of cis-UCA to alter the development of DC in vitro was confirmed by analysing the functional capacity of DC in MLR. DC generated in the presence of cis-UCA were equally efficient in the induction of allo-stimulation, when compared with control DC. These results suggest that cis-UCA does not exert its immunosuppressive activity through direct effects on DC. Such activity may be independent of DC, or alternatively, cis-UCA may influence DC function indirectly, through the induction of secondary mediators.
It is well established that low-dose UVB radiation inhibits the antigen-presenting cell (APC) function of murine Langerhans cells in vivo and converts them from immunogenic to tolerogenic APC. Recently, we have shown that UVB-irradiated murine bone marrow-derived dendritic cells (UVB-DC) suppressed proliferation of naive and primed T cells, but tolerized primed T cells only. To examine the underlying mechanism for these differences, naive OVA(323-339)-peptide-specific, TCR-transgenic T cells from DO11.10 mice were analyzed following coculture with unirradiated DC or UVB-DC. First, we found that UVB-DC inhibit OVA-specific T cell proliferation UVB dose and antigen dose dependently. Analysis of T cells cocultured with both, unirradiated and UVB-DC, revealed an activated T cell phenotype with increased expression of CD25 and CD69 by FACS. Supernatants harvested from cocultures with UVB-DC showed reduced levels of IFN-gamma, IL-2 and IL-4, but not TGF-beta, compared with unirradiated DC as determined by ELISA. Furthermore, these T cells did not proliferate upon restimulation. Interestingly, addition of these nonproliferating T cells to cocultures of naive T cells and freshly prepared unirradiated DC inhibited T cell proliferation depending on the number of added nonproliferating T cells. Also, in supernatants, increased levels of TGF-beta were found. Therefore, our data indicate that UVB-DC propagate T cells with a regulatory function. Since regulatory T cells are characterized by enhanced TGF-beta secretion and increased CTLA-4 expression, we currently investigate the role of CTLA-4 phenotypically and functionally. In conclusion, we have shown that UVB-DC inhibit proliferation of naive OVA-specific T cells. These T cells, exhibiting an activated phenotype and increased TGF-beta production, suppress proliferation of naive T cells cocultured with unirradiated DC. These results suggest that UVB-DC induce nonproliferating, regulatory type T cells.
The photodynamically active plant pigment hypericin, a characteristic metabolite of Hypericum perforatum (St. John's wort), is widely used as an antidepressant. When administered orally, phototoxic symptoms may limit the therapeutic use of hypericin-containing drugs. Here we describe the high-performance liquid chromatographic (HPLC) detection of hypericin and semiquantitative detection of pseudohypericin in human serum and skin blister fluid after oral single-dose (1 x 6 tablets) or steady-state (3 x 1 tablet/day, for 7 days) administration of the Hypericum extract LI 160 in healthy volunteers (n = 12). Serum levels of hypericin and pseudohypericin were always significantly higher than skin levels (p </= 0.01). After oral single-dose administration of Hypericum extract the mean serum level of total hypericin (hypericin + pseudohypericin) was 43 ng/ml and the mean skin blister fluid level was 5.3 ng/ml. After steady-state administration the mean serum level of total hypericin was 12.5 ng/ml and the mean skin blister fluid level was 2.8 ng/ml. These skin levels are far below hypericin skin levels that are estimated to be phototoxic (>100 ng/ml).
Based on encouraging reports of improved response rates with the use of dacarbazine (DTIC) in combination with recombinant interferon alpha-2a (rIFN-alpha-2a) in patients with metastatic malignant melanoma, we conducted a phase II study to determine the efficacy and feasibility of this treatment regimen. 31 patients were treated with an induction dose of rIFN-alpha-2a at 15 MIU/ m2 intravenously (i.v.) daily for 5 days per week for 3 consecutive weeks followed by a continuous maintenance dose of 10 MIU/m2 subcutaneously (s.c.) given 3 days per week; starting on day 22, in conjunction with rIFN-alpha-2a s.c., DTIC was started at a dose of 200 mg/m2 i.v. for 5 continuous days completing a 28-day cycle. Therapy was continued until progression was evidenced. Of the 29 evaluable patients, 7 (24.1%) achieved an objective response (complete plus partial remission) with the highest responses occurring in those patients assessed with pulmonary metastases. The median duration to treatment failure was 2.6 months, while the median survival was 6.9 months. Our data reveal that using rIFN-alpha-2a plus DTIC in combination does not yield better results than those achieved when using DTIC alone. However, 3 of the 7 responders experienced long-term survival ranging up to 42 months. Whether this benefit is achieved by the addition of rIFN-alpha-2a can only be answered by large randomized clinical trials. Conflicting results with some of the current literature are discussed.
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The fate of 15N-labeled cattle (Bos taurus) urine (52 g N m(-2)), applied to a 0.4-m2 surface area on three dates between May and October to three different pasture soils, was studied using 2-m2 lysimeters. Over a period of two years, the sward recovered most of the 15N, but the amount recovered decreased with application date (62% in spring to 17% in fall). However, N uptake by ryegrass (Lolium perenne L.) in Year 2 showed that some nitrogen came from the previous year's urine application. The largest leaching losses of urine N resulted from the late application date. These losses mainly occurred during the first winter despite the small amount of water drainage. Soil type largely determined 15N losses. The granitic Brunisol was the most freely draining and had the greatest leaching (up to 35% recovery of urinary N). In contrast, leaching in the silty loam Neoluvisol remained under 4% of 15N applied. The Calcosol appeared to be susceptible to all kinds of N losses with intermediate unaccounted-for N pool and leaching fractions and lesser utilization of urinary N by grass. Immobilization in soil organic matter, roots and litter, and stubble pools were not markedly influenced by the date of application or soil type. They amounted to 25 to 33, 2, and 2% of N applied as urine, respectively. In these climatic conditions with moderate drainage, leaching of water poor in quality for nitrate only occurred for late-season grazing or on the granitic Brunisol, which was very vulnerable to leaching.
An experiment was performed to better understand to what extent nitrogen fertilization rate and date and amount of urine deposition, when acting in combination, influence nitrate leaching under grassland. Leaching was studied during two successive winters using 2-m2 grassed lysimeters under three levels of N fertilization (0, 150, and 300 kg N ha(-1) yr(-1), referred to as 0N, 150N, and 300N, respectively), two levels of 15N-labeled urine (105 and 165 kg N ha(-1), referred to as A2 and A3, respectively), and three dates of urine application (spring, summer, and fall). During the first winter, total N leaching losses varied between 2 and 50 kg N ha(-1). When tested in combination, N applied as urine to grassland resulted in three times the total N loss by leaching that occurred following N fertilization in the first winter (4.3, 20.8, 34.9, 14.2, 17.1, and 28.7 kg NO3- -N ha(-1) for no urine, A2, A3, ON, 150N, and 300N, respectively). Leaching of 15N urine significantly depended on the date of application: 6.6, 17.3, and 29.1 kg for spring, summer, and fall, respectively. A similar pattern was observed for the contribution of 15N urine to total N leaching with 4.3, 12.9, and 21.4%. However, urine application, both in terms of amount and date, showed very little long-term effect on these N losses in Year 2. In our conditions of low winter rainfall and drainage, grazing management (through season, urinary N amounts, and urine N concentration) resulted in a higher impact on water nitrate quality than moderate N fertilization management.
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