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Biomedical subjects

C Schmidt

Publications and source records attributed to C Schmidt.

At least 253 records · Page 14Linked to original sources
PubMed1996

Recruitment during infectious mononucleosis of CD3+CD4+CD8+ virus-specific cytotoxic T cells which recognise Epstein-Barr virus lytic antigen BHRF1.

Epstein-Barr virus (EBV) is the aetiological agent of infectious mononucleosis (IM) which is a common sequel to primary EBV infection. Thereafter, the virus is maintained as a lifetime latent infection. Although the proteins expressed during the latent EBV infection provide a rich source of immunogenic epitopes, very little is known about cytotoxic T lymphocyte (CTL) control of primary EBV infection. The present report is based on an analysis of CTL clones derived from a patient suffering from acute IM. An intriguing feature of six CTL clones that displayed an HLA-restricted pattern of cell lysis was their initial coexpression of the T cell markers CD3, CD4, and CD8. Detailed analysis of one of these clones, which was restricted through the class II MHC antigen DR2, revealed reactivity with an epitope within the EBV lytic cycle early antigen, BHRF-1, which corresponds to the C-terminal region of the protein (AGLTLSLLVICSYLFISRG) (residues 171-189). There have been no previously published reports describing a CTL response during acute IM directed against an EBV lytic antigen. Interestingly, the coexpression of CD4 and CD8 by these CTLs during acute IM suggests that CD3+CD4+CD8+ cortical thymocytic precursor cells are recruited in order to overcome the EBV infection.

Acute Disease↗
PubMed1996

Comparison of leg compression stocking and oral horse-chestnut seed extract therapy in patients with chronic venous insufficiency.

BACKGROUND: Diseases of the venous system are widespread disorders sometimes associated with modern civilisation and are among the major concerns of social and occupational medicine. This study was carried out to compare the efficacy (oedema reduction) and safety of compression stockings class II and dried horse chestnut seed extract (HCSE, 50 mg aescin, twice daily). METHODS: Equivalence of both therapies was examined in a novel hierarchical statistical design in 240 patients with chronic venous insufficiency. Patients were treated over a period of 12 weeks in a randomised, partially blinded, placebo-controlled, parallel study design. FINDINGS: Lower leg volume of the more severely affected limb decreased on average by 43.8 mL (n = 95) with HCSE and 46.7 mL (n = 99) with compression therapy, while it increased by 9.8 mL with placebo (n = 46) after 12 weeks therapy for the intention-to-treat group (95% CI: HCSE: 21.1-66.4; compression: 30.4-63.0; placebo: 40.0-20.4). Significant oedema reductions were achieved by HCSE (p = 0.005) and compression (p = 0.002) compared to placebo, and the two therapies were shown to be equivalent (p = 0.001); in this design, however, compression could not be proven as standard with regard to oedema reduction in the statistical test procedure. Both HCSE and compression therapy were well tolerated and no serious treatment-related events were reported. INTERPRETATION: These results indicate that compression stocking therapy and HCSE therapy are alternative therapies for the effective treatment of patients with oedema resulting from chronic venous insufficiency.

Bandages↗
PubMed1996

CD9 of mouse brain is implicated in neurite outgrowth and cell migration in vitro and is associated with the alpha 6/beta 1 integrin and the neural adhesion molecule L1.

We describe here a novel monoclonal antibody (mab H6) which recognizes CD9, an integral cell surface constituent previously described in cells of the hematopoietic lineage and involved in the aggregation of platelets. Mab H6 was raised against membranes of immature mouse astrocytes and reacted with a protein of 25-27 kD in detergent extracts of adult mouse brain membranes. Sequence analysis of the N-terminal amino acids revealed an identity of 96% with CD9 from mouse kidney. CD9 was localized in the central and peripheral mouse nervous systems: in the spinal cord of 11-day-old mouse embryos, CD9 was strongly expressed in the floor and roof plates. In the adult mouse sciatic nerve, myelin sheaths were highly CD9-immunoreactive. Mab H6 reacted with the cell surfaces of both glial cells and neurons in culture and inhibited migration of neuronal cell bodies, neurite fasciculation and outgrowth of astrocytic processes from cerebellar microexplants. Neurite outgrowth from isolated small cerebellar neurons was increased in the presence of mab H6 on substrate-coated laminin, but not on substrate-coated poly-L-lysine. Addition of mab H6 elicited an increase in intracellular Ca2+ concentration in these cells on substrate-coated laminin. Immunoprecipitates of CD9 from cultured mouse neuroblastoma N2A cells contained the alpha 6/beta 1 integrin. Moreover, preparations of CD9 immunoaffinity-purified from adult mouse brain using a mab H6 column contained the neural adhesion molecule L1, but not other neural adhesion molecules. CD9 bound to L1, but not to NCAM or MAG. Both the alpha 6/beta 1 integrin and L1 could be induced to coredistribute with CD9 on the surface of cultured neuroblastoma N2A cells. The combined observations suggest that CD9 can associate with L1 and alpha 6/beta 1 integrin to influence neural cell interactions in vitro.

Amino Acid Sequence↗
PubMed1996

Trends in photoprotection in American fashion magazines, 1983-1993. will fashion make you look old and ugly?

BACKGROUND: During the past 50 years recreational sun exposure has greatly increased in the United States. OBJECTIVE: The purpose of this study was to examine the photoprotecion message of American fashion magazines and to identify recent trends. METHODS: We evaluated models for tan, skin exposure, and other sun-related criteria in six leading fashion magazines between 1983 and 1993. We also recorded the number of sunscreen advertisements and sun awareness articles. RESULTS: We evaluated 3031 models. Adult models had darker tans and greater skin exposure than adolescents and children. Men had darker tans than women. We noted trends toward lighter tans, more women wearing hats, more sunscreen advertisements, and sun awareness articles. Many sunscreen advertisements glorified tanning. Their models had darker tans and more skin exposure, and fewer wore a hat than did nonadvertisement models. CONCLUSION: The fashion industry and especially sunsreen manufacturers promote excessive sun exposure. Although we found encouraging trends, gains were modest, especially in men's magazines.

Adolescent↗
PubMed1996

Tricuspid valve reconstruction, a treatment option in acute endocarditis.

Tricuspid valve endocardititis is treated surgically by total valve excision or valve replacement. Both procedures are controversial with regard to the hemodynamic consequences and to the long-term prognosis. In the following, results of tricuspid valve repair in acute infective endocarditis are reported and discussed as an additional treatment option. Between January 1988 and December 1993, 118 patients were operated on for acute valve endocarditis at our institution. Eleven of these patients had tricuspid valve endocarditis, isolated (n = 7) or combined with endocarditis of a left-sided valve (n = 4). In the cases with isolated tricuspid valve endocarditis, the indication for surgery was intractable infection in six and hemodynamically relevant tricuspid insufficiency in one out of seven patients. In all patients with associated left-sided endocarditis, the indication was hemodynamic deterioration. In eight patients the tricuspid valve endocarditis was treated as follows: debridement, vegectomy, patch reconstruction of the cusps, reducing the cusps to two. In three patients reconstruction was not possible because of extensive involvement of all parts of the valve, including the valve ring and the papillary muscles. In these patients primary valve replacement (n = 1) or valve excision with secondary replacement (n = 2) was performed. In four patients tricuspid reconstruction was combined with mitral (n = 1), aortic (n = 1) or double valve replacement (n = 2). Postoperatively, signs of infection vanished in all surviving patients (n = 10) and tricuspid valve endocarditis healed without recurrences. Implanted prosthetic material did not lead to recurrent infection. One patient died early postoperatively after valve excision, in septic shock and multi-organ failure. In seven patients late echocardiographic follow-up showed tricuspid regurgitation grade 0 in three patients, I in two, II in one and III in one. Our results suggest that valve repair is a reasonable treatment option for tricuspid valve endocarditis in all cases with localized infection of the valve. Only if extensive valve destruction excludes valve repair, would we now favor primary valve replacement over simple valvulectomy. In all other cases primary valve reconstruction is the treatment of choice for tricuspid valve endocarditis, if surgery is indicated.

Acute Disease↗
PubMed1996

Combining methods to identify new measures of women's drinking problems. Part I: The ethnographic stage.

In recent years, some researchers in the alcohol survey field have raised concerns about the shortcomings in severity/frequency scales for drinking and drinking problems used for both clinical and household survey purposes, especially with regard to women. This article reports on Part I of a two-part study that used ethnographic and survey methods to assess indicators of drinking problems among women across various US subcultures. Methodology for the ethnographic component consisted of three steps: analysis of findings in literature on indicators of women's drinking problems, and analysis of indicators addressed in the most commonly used standard instruments for alcohol assessment; semi-structured interviews with 12 specialists in treatment and/or research who focused on alcohol problems of women; and semi-structured interviews with 65 women from four ethnic populations who were clients in alcohol treatment centers. Analysis of these data from the ethnographic component produced a taxonomy of indicators of women's drinking problems and fourteen novel indicators that are not included or are inadequately examined in the most commonly used alcohol assessment instruments. The novel indicators were then incorporated into a questionnaire used for a county-wide survey of men and women that assessed indicators of drinking problems. Report of findings from the survey are presented in the second paper of this series.

Adolescent↗
PubMed1996

Multiple cardiac procedures after heart transplantation: a case report.

We report on a 56-year-old patient who underwent coronary artery bypass grafting, tricuspid valve replacement, and pacemaker implantation within 49 months after heart transplantation. This case readily demonstrates that multiple cardiac procedures can be safely performed after heart transplantation and may thus serve as an alternative to retransplantation.

Cardiac Surgical Procedures↗
PubMed1996

[Liposarcoma of the uterus--a case report].

The case of a 78-year-old patient suffering from a liposarcoma of the uterus is described. This malignant tumour which belongs to the group of mesenchymal tumours is very rare. The patient underwent an abdominal hysterectomy with adnexectomy on the left. Since then she has been regularly controlled for more than three years now and no recurrence or metastasis has been found.

Aged↗
PubMed1996

Increased prostaglandin E2 and leukotriene B4 synthesis in isolated colonic mucosal cells in inflammatory bowel disease. a preliminary report.

The synthesis of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) in colonic mucosal cells was investigated in 7 patients and 10 controls. Biopsies obtained from the descending colon were isolated biochemically by a special technique and the suspension of isolated colonic cells was incubated during 45 min. Compared with healthy subjects, patients with an inflammatory bowel disease showed a significantly increased PGE2 production. The LTB4 synthesis was enhanced as well, but this change was not statistical. We conclude that PGE2 is the dominant eicosanoid during less severe inflammatory bowel disease. Age and gender did not influence PGE2 or LTB4 synthesis.

Adult↗
PubMed1996

Three functions of bacteriophage P1 involved in cell lysis.

Amber and deletion mutants were used to assign functions in cell lysis to three late genes of bacteriophage P1. Two of these genes, lydA and lydB of the dar operon, are 330 and 444 bp in length, respectively, with the stop codon of lydA overlapping the start codon of lydB. The third, gene 17, is 558 bp in length and is located in an otherwise uncharacterized operon. A search with the predicted amino acid sequence of LydA for secondary motifs revealed a holin protein-like structure. Comparison of the deduced amino acid sequence of gene 17 with sequences of proteins in the SwissProt database revealed homologies with the proteins of the T4 lysozyme family. The sequence of lydB is novel and exhibited no known extended homology. To study the effect of gp17, LydA, and LydB in vivo, their genes were cloned in a single operon under the control of the inducible T7 promoter, resulting in plasmid pAW1440. A second plasmid, pAW1442, is identical to pAW1440 but has lydB deleted. Induction of the T7 promoter resulted in a rapid lysis of cells harboring pAW1442. In contrast, cells harboring pAW1440 revealed only a small decrease in optical density at 600 nm compared with cells harboring vector alone. The rapid lysis phenotype in the absence of active LydB suggests that this novel protein might be an antagonist of the holin LydA.

Amino Acid Sequence↗
PubMed1996

The effect of 5-aminosalicylate and para-aminosalicylate on the synthesis of prostaglandin E2 and leukotriene B4 in isolated colonic mucosal cells.

The effect of 5-aminosalicylate (5-ASA) and para-aminosalicylate (PAS) on the synthesis of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) was studied in 24 healthy volunteers. Both drugs are successfully used in the treatment of chronic inflammatory bowel disease, but the biochemical pathway of their anti-inflammatory action is still unknown. Biopsies were taken from the descending colon and were isolated biochemically. 5-ASA, PAS and a control were added to the suspension of isolated colonic mucosal cells and incubated over 0-45 min. Both 5-ASA and PAS did not alter the PGE2 production but, compared with PAS and the control, 5-ASA decreased the LTB4 synthesis in a dose-related fashion. As a result, the LTB4/PGE2 ratio was significantly diminished by 10(-4) mol/l 5-ASA. These findings are consistent with those of other authors, indicating that 5-ASA, at least in part, modulates the colonic eicosanoid synthesis. In contrast, PAS did not influence the mucosal production of PGE2 and LTB4 and therefore must exert some other biochemical action in order to explain its therapeutic effects in the treatment of Crohn's disease or ulcerative colitis.

Adult↗
PubMed1996

Coefficient of variation: a powerful Doppler ultrasonographic parameter for detection of renal artery stenosis.

The aim of our study was to objectively compare the effectiveness of various Doppler parameters in the diagnosis of renal artery stenosis. In three sheep, variable degrees of renal artery stenosis were induced and renal segmental arteries were investigated using pulsed Doppler sonography. In each animal the standard deviation of the instantaneous peak velocity within one cardiac cycle normalized by the mean peak velocity (coefficient of variation) had significantly higher normalized regression coefficients (k* = -0.215, average of three animals) when compared to resistive index (k* = -0.090) and acceleration index (k* = -0.069). In each individual animal, coefficient of variation detected lower pressure gradients (6.3 mm Hg, average value) than did resistive index (13.4 mm Hg) or acceleration index (17.3 mm Hg). The coefficient of variation may detect the presence of pressure gradients in renal artery stenosis more accurately than acceleration index or resistive index.

Animals↗
PubMed1996

[Population development and economic growth. A simulation analysis for Switzerland].

"A simulation exercise of a general equilibrium model for Switzerland makes clear that the macroeconomic impacts of aging populations are not very strong. There is no need for urgent policy actions to avoid severe negative economic consequences....However, the aging of population affects negatively the net income of the active labor force. An increasing share of their gross salaries goes to the retirement system to finance the pension payments of a growing number of pensioners. Attempts to moderate the elderly dependency ratio would lower this burden for the active labor force. Options are an increase of the female participation rate, an increase of the labor participation rate of the elderly--[which] also means a higher retirement age--and an increasing flow of immigrants. But socioeconomic problems might probably generate practical limits on the extent to which immigration can be increased." (SUMMARY IN ENG AND FRE)

Demography↗
PubMed1996

Pharmacologically induced heart failure for the evaluation of circulatory assistance.

For the evaluation of the hemodynamic interaction between the natural heart and an assist device, a reversible pharmacological model based on the channel blocker Verapamil under hyperkalemia, was developed for deterioration of left ventricular function. Four calves weighing 70-90 kg underwent standard implantation for left atrioaortal assist (BioMedicus, BP-80), pump anesthesia (oxygen/isoflurane [1%]; 8 mg/kg of BW/h ketamine), and of ventricular demand pacing at 120 bpm. Left atrial pressure (LAP), ventricular pressure (LVP), aortic pressure (AoP), pulmonary arterial (Qpulm) pressures, and graft flow (Qgraft) were monitored. The hemodynamic effects of anesthetic overdose (2% Isoflurane) were compared with those of Verapamil (Isoptin: 0.2 mg/kg BW/h 5 mmol/kg of BW/h of KCl) medication. Both regimens caused a decreased in AoP to < or = 50%. For Isoflurane, a slight reduction in cardiac output (CO) of 10% at a nearly constant LAP and a strong decrease of the peripheral resistance (Rperi) of 35% could be seen where Isoptin caused a significant reduction in CO of 40% at an increased LAP (+25%) and changes in Rperi of < 10%. Because the vascular tonus remains nearly constant, the hemodynamic effects are controllable and reversible (antagonized with calcium chloride); thus we conclude that Verapamil administration under hyperkalemia conditions is a proper model for mimicking congestive heart failure with low systemic side effects.

Anesthetics, Inhalation↗