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Biomedical subjects

P Schmid

Publications and source records attributed to P Schmid.

At least 91 records · Page 5Linked to original sources

Biological monitoring of the fungicide epoxiconazol during application.

A method was developed for the biological monitoring of the fungicide epoxiconazol (Opus; BASF). Comparison of the urine levels of a hydroxylated metabolite after dermal application to the levels after oral intake revealed a dermal absorption of 1-2.5% of the dose. In a field study with 10 applicators a dermal exposure ranging between 60 and 10,000 microgram/person/day was determined from the urine levels of a hydroxylated metabolite; the contribution of the inhalation exposure was found to be negligible. From these data an incorporation of 1 to 100 microgram epoxiconazol/person/day could be derived. The measured exposure was compared to two commonly used exposure models. The model calculation resulted in a dermal exposure of 555 microgram/person/day (German BBA model) and 2115 microgram/person/day (British POEM), respectively, which is in accordance with the actually measured exposure.

Adult↗

The transfer of polychlorinated dibenzo-p-dioxins and dibenzofurans from soil into eggs of foraging chicken.

The levels of the 2,3,7,8-chlorosubstituted PCDD/Fs (polychlorinated dibenzo-p-dioxins and dibenzofurans) were determined in eggs of foraging chicken and in the corresponding soils. Compared to eggs from hens kept without soil contact the determined levels were clearly elevated. These increased levels were attributed to soil related PCDD/F uptake and were used to deduce congener specific factors describing the transfer from soil into the eggs by the foraging. Based on these transfer factors an calculation method allowing the prediction of the 2,3,7,8-TCDD toxic equivalent (I-TEq) levels in eggs based on the PCDD/F concentrations in soil was developed. The comparison of predicted and determined PCDD/F levels was used to discuss limitations and uncertainties of the model. Based on a given soil contamination, this approach allows a conservative prediction of the I-Teq levels in eggs of foraging chicken.

Animal Feed↗

Long-term follow-up of patients with chronic hepatitis B treated with interferon alfa.

BACKGROUND & AIMS: Therapy with interferon alfa (IFN-alpha) leads to remission of disease in one third of patients with chronic hepatitis B. The aim of this study was to better define the long-term prognosis of this outcome. METHODS: One hundred three patients with chronic hepatitis B who underwent IFN-alpha therapy in three clinical trials between 1984 and 1991 were followed up for serological status, biochemical evidence of liver disease, and liver complications or mortality through 1994. RESULTS: Among 103 patients, 31 (30%) responded to therapy with loss of hepatitis B e antigen and viral DNA from serum. Responders were more likely than nonresponders to be women, black, and to have more severe liver disease including cirrhosis (P < 0.05). Up to 11 years (mean, 6.2 years) after therapy, a higher percentage of responders than nonresponders were still negative for hepatitis B e antigen (94% vs. 40%; P < 0.001) and hepatitis B surface antigen (71% vs 8.3%; P < 0.001). Overall, the rate of liver-related complications and death did not differ by IFN-alpha response, but with adjustment for cirrhosis, nonresponders had higher rates of liver-related complications and mortality (hazard ratio, 13.7; 95% confidence interval, 3.0-63.5). CONCLUSIONS: The response to IFN-alpha therapy in chronic hepatitis B is usually a sustained improvement in disease markers and, when cirrhosis is considered, patient outcome.

Adult↗

The Conconi test.

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Anaerobic Threshold↗

Heart rate performance curve during incremental cycle ergometer exercise in healthy young male subjects.

In 1992 Conconi et al. (20) presented an indirect and noninvasive method for the determination of anaerobic threshold (AnT) in an incremental field test for runners. This noninvasive method for the determination of anaerobic threshold is dependent on the occurrence of a deflection of the heart rate performance curve (HRPC). The aim of our study was to evaluate the degree and direction of the deflection of the HRPC and the relationship of the heart rate threshold (HRT) to the lactate turn point in a group of 227 healthy young subjects (age: 23 +/- 4 yr). The subjects were divided into three groups by means of second degree polynomial fitting (GI: regular deflection, kHR > 0.1; G II: no deflection, 0 < kHR < 0.1; G II: inverse deflection, k < -0.1). No significant differences between the groups were found in the anthropometric data or in the power output and the blood lactate concentration at both the first (LTP1) and second (LTP2) lactate turn points and at maximum performance (Pmax). Using the method of Conconi et al. (20), 85.9% of the subjects showed a "regular" deflection, 6.2% showed no deflection at all, and 7.9% showed even an inverted deflection of the HRPC. An HRT could be obtained in both G I and G III, and power output at HRT was not significantly different in comparison to that at the LTP2. No HRT could be assessed in G II. The heart rate at HRT and the LTP2 were significantly lower in G III compared with G I. The phenomenon of heart rate break point may be attractive in training regulation, but its application is limited because a heart rate deflection cannot be found even in young subjects in some cases.

Exercise↗

Left ventricular function in response to the transition from aerobic to anaerobic metabolism.

The purpose of this investigation was to study myocardial function at rest, during three phases of energy supply, and during recovery. Radionuclide angiography was performed during the aerobic phase (phase I, rest-first lactate increase), the aerobic-anaerobic transition phase (phase II, first lactate increase-second lactate increase), the anaerobic phase (phase III, second lactate increase-maximal work performance (Pmax)), and during recovery. Thirty-eight male patients (59 +/- 7 d after myocardial infarction) were compared with 19 healthy control subjects and 21 sport students of comparable age. Left ventricular ejection fraction (LVEF) increased from rest to phase I and from phase I to phase II in sports students and control subjects. During phase III, LVEF did not change significantly in sports students, but it decreased significantly in control subjects. This is in contrast to the patients, who showed an increase of LVEF from resting values (47 +/- 3%) to phase I (50 +/- 1%), no change during phase II (51 +/- 2%), and a decrease to resting values (45 +/- 2) during phase III. All subjects showed an increase in stroke volume (SV) during phase I and II, reaching a maximum at phase II. This was evidenced by an improvement of the systolic function with a constant left ventricular end-diastolic volume (EDV) in control subjects and sports students. In contrast, an improved SV in patients was achieved through an increase in EDV and a less distinct increase in the left ventricular end-systolic volume (ESV). Maximal LVEF values were measured during the first 90 s of recovery in all subjects. Values during recovery are not representative of load dependent myocardial function. This increase in LVEF does not cause an increase in cardiac output but is a consequence of changes in the EDV and ESV, which decrease again immediately after the end of exercise performance.

Adult↗

The anisotropic structure of the human left and right ventricles.

An important determinant of cardiac output derives from the structure of the ventricular wall given by the arrangement of the cardiac muscle fibres. A key feature of this arrangement is both a global and local anisotropy. First, a preparation method necessary for analyzing the main aspects of spatial fibre architecture is outlined. Global anisotropy can be described by a gross band-like structure wrapping both left and right ventricles while local anisotropy results from the arrangement of the individual muscle fibres within the band. In pathologic cases this basic structure may be disturbed leading to cardiac failure. Second, a Finite Element model, formulated on the basis of Magnetic Resonance measurements has been devised which is intended to reflect the global as well as the local anisotropy of the ventricles in order to further the understanding of cardiac performance.

Animals↗

[Contribution to the treatment of acute bovine mastitis with cefquinome].

Cefquinome is the first 4th generation cephalosporin antibiotic developed for use in veterinary medicine. A European multicentre study established a high in vitro activity for this modern antimicrobial drug against a wide spectrum of bovine pathogens. Gram-positive and gram-negative mastitis agents were inactivated even at very low active ingredient concentrations, including Enterobacteriaceae which are often resistant to other drugs. The results of clinical trials using experimental E. coli mastitis as an example demonstrate the efficacy of cefquinome in vivo. Parenteral administration at a dose rate of 1 mg/kg body weight when compared with conventional therapy using a control drug with equally good in vitro activity, produced significantly better therapeutic results.

Animals↗

[Observations on resistance monitoring in animal health].

This article describes conventional procedures which are used for susceptibility testing of bacteria isolated from food producing animals against anti-infective substances. Interpretation of results obtained from the different test methods and the conditions necessary to conduct these tests in view of a meaningful resistance monitoring are discussed. Currently, published data about the resistance situation in veterinary medicine are either not representative or have been determined under suboptimal conditions. In view of the public and often non-scientifically based discussion about bacterial resistance it is absolutely necessary to generate a scientifically valid database.

Animal Husbandry↗

Detection of metastatic breast cancer by beta-hCG polymerase chain reaction.

Reverse transcriptase-polymerase chain reaction (RT-PCR) for detection of occult malignancies in breast cancer patients is evolving as a useful diagnostic tool. However, no reliable molecular mRNA markers are available. We developed an RT-PCR plus Southern blot assay using beta-hCG (beta-subunit of human chorionic gonadotropin) gene expression as a tumor marker for detection of breast malignancies metastatic to tumor-draining lymph nodes and blood. Breast carcinoma cell lines, primary breast malignancies and human placenta were used as positive controls for establishing the beta-hCG RT-PCR assay. Peripheral blood leukocytes (PBL) from normal volunteer donors, normal breast tissue and lymph nodes from cancer-free patients were used as negative controls. beta-hCG RT-PCR was used to assess tumor cell presence in PBL and tumor-draining axillary nodes from patients with AJCC stage I-IV breast cancer. The assay sensitivity and specificity were enhanced by restriction endonuclease digestion of an Sty I site of the RT-PCR cDNA product followed by Southern blot analysis. beta-hCG mRNA was expressed in all breast cancer cell lines and 80% of primary breast cancers; it was not expressed in negative controls. The assay reliably detected one cancer cell in > 10(7) PBL, with a sensitivity of 10(-5) microgram RNA. Eighty percent of PBL and 61% of tumor-draining axillary nodes from breast cancer patients expressed beta-hCG mRNA. The assay is a sensitive and specific method of identifying breast cancer cells in breast tissues, lymph nodes and blood.

Biomarkers, Tumor↗

Molecular cloning of a human melanoma-associated chondroitin sulfate proteoglycan.

A human melanoma-associated chondroitin sulfate proteoglycan (MCSP), recognized by mAb 9.2.27, plays a role in stabilizing cell-substratum interactions during early events of melanoma cell spreading on endothelial basement membranes. We report here the molecular cloning and nucleotide sequencing of cDNA encoding the entire core protein of human MCSP and provide its deduced amino acid sequence. This core protein contains an open reading frame of 2322 aa, encompassing a large extracellular domain, a hydrophobic transmembrane region, and a relatively short cytoplasmic tail. Northern blot analysis indicated that MCSP cDNA probes detect a single 8.0-kb RNA species expressed in human melanoma cell lines. In situ hybridization experiments with a segment of the MCSP coding sequence localized MCSP mRNA in biopsies prepared from melanoma skin metastases. Multiple human Northern blots with an MCSP-specific probe revealed a strong hybridization signal only with melanoma cells and not with other human cancer cells or a variety of human fetal and adult tissues. These data indicate that MCSP represents an integral membrane chondroitin sulfate proteoglycan expressed by human malignant melanoma cells. The availability of cDNAs encoding MCSP should facilitate studies designed to establish correlations between structure and function of this molecule and help to establish its role in the progression of human malignant melanoma.

Adult↗

Testicular germ cell tumors in patients with human immunodeficiency virus infection.

BACKGROUND: There has been evidence of a higher incidence of testicular germ cell tumors (GCT) in human immunodeficiency virus (HIV)-seropositive men than in the non HIV-infected male population. Most authors recommend standard therapy for HIV-positive patients with GCT but the immumosuppressive effects of chemotherapy and/or radiotherapy must be considered. METHODS: The records of all patients in whom testicular cancer was diagnosed and/or treated at a single institution between January 1986 and July 1995 were reviewed with regard to HIV seropositivity. Tumor histology, initial staging, treatment, and the patients' outcomes were analyzed in connection with a review of the literature. RESULTS: Six patients with GCT and documented HIV seropositivity at the time of tumor diagnosis (four homosexuals, one bisexual, and one heterosexual former intravenous drug abuser) of 192 documented cases of testicular cancer are reported. In addition, 1 patient proved to be HIV seropositive 34 months after completing chemotherapy (vinblastine, ifosfamide, and cisplatin) for Stage IIB (minimal disease) seminoma. Intensified platinum-based chemotherapy was administered to two patients with clinical Stage IIIC (advanced disease) nonseminomatous germ cell tumors (NSGCT). Both patients achieved a transient partial response but suffered from progressive HIV disease and died 24 and 7 months, respectively, after orchiectomy. One patient with Stage IIIA (moderate disease) seminoma received four courses of chemotherapy (etoposide, ifosfamide, and cisplatin) and has remained in complete remission for 40 months. One patient with bilateral Stage I seminoma underwent adjuvant radiotherapy but was lost to follow-up. One patient with clinical Stage IIA (minimal disease) NSGCT refused any further treatment after hemiorchiectomy, but four courses of chemotherapy (cisplatin, etoposide and bleomycin) had to be given 32 months later because of symptomatic abdominal disease. A partial remission was obtained and there was no evidence of active tumor 16 months after the completion of chemotherapy. A retroperitoneal lymph node dissection was performed in 1 patient with Stage I NSGCT who was free of disease 111 months after diagnosis. The Centers for Disease Control classification for HIV infection and acquired immune deficiency syndrome (AIDS) did not change after therapy in two patients, whereas three patients suffered from progressive HIV disease. CONCLUSIONS: HIV infection should be considered in patients with testicular cancer who belong to an urban population. Oncologic therapy based on a patient's individual situation is recommended.

Adult↗

Passive smoking and platelet thromboxane.

While active smoking is known to enhance platelet thromboxane production, no data on passive smoking is available yet. The influence of single and repeated exposure to passive smoke for 60 minutes in a 18 m3 room was assessed in non-smokers as compared to sex and age matched smokers. All the evaluated measures (malondialdehyde, plasma thromboxane B2, 11-dehydro-thromboxane B2, serum thromboxane B2, conversion of exogenous arachidonic acid to thromboxane B2 and to hydroxy-5, 8,10-heptadecatrienoic acid) were higher in smokers than non-smokers at baseline, immediately and 6 hours after passive exposure to cigarette smoke. Repeated exposure of non-smokers rendered their platelets more activated becoming close to the behaviour of smokers. These results indicate that passive smoking may activate thromboxane A2 release from the platelets, contributing to the development of hemostatic imbalance.

Adult↗

The pattern of prothymosin alpha gene expression coincides with that of myc proto-oncogenes during mouse embryogenesis.

The nuclear protein prothymosin alpha is thought to play a critical role in cellular proliferation. Transcription of the gene encoding prothymosin alpha has been shown to be activated by the proto-oncogene c-myc. Also, prothymosin alpha mRNA expression correlates with that of c-myc in human colon cancer. We compared the previously reported embryonic expression pattern of the proto-oncogene c-myc and the pattern of the prothymosin alpha gene by in situ hybridization. Prothymosin alpha is transcribed in all tissues expressing c-myc, including brown adipose tissue, salivary gland, thymus and liver. In addition, we show that the prothymosin alpha gene is active in tissues expressing specifically N-myc such as the neuronal anlage and hair follicles in skin. Therefore, during mouse foetal development the temporal, spatial and tissue-specific expression patterns of both myc proto-oncogenes coincide with the pattern of prothymosin alpha.

Adipose Tissue, Brown↗