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Biomedical subjects

T Schmid

Publications and source records attributed to T Schmid.

At least 37 records · Page 2Linked to original sources
PubMed2003

Biofilm monitoring by photoacoustic spectroscopy.

The use of photoacoustic spectroscopy (PAS) as a new biofilm monitoring technique is presented. Growth and detachment of biofilms at three different positions inside a flow channel were monitored by photoacoustic measurements in the visible spectral range (lambda = 532 nm). The experimental approach allows the investigation of the influence of various process parameters (e.g. pH or flow conditions) on growth and detachment of biofilms. In addition, the distribution of the attached biomass can be monitored by depth-resolved photoacoustic measurements.

Acoustics↗
PubMed2002

A photoacoustic technique for depth-resolved in situ monitoring of biofilms.

Biofilms occur in natural and engineered water systems. Biofouling in technical processes lowers the water quality and increases the frictional resistance in tubes. In wastewater treatment plants, biofilms are used for removal of organic an inorganic pollutants. For improvement of antifouling strategies and for process optimization in wastewater treatments plants, an analytical technique for online monitoring of biofilms is needed. In this article, a new setup for in situ monitoring of biofilms by photoacoustic spectroscopy is presented. To produce a biofilm, a mixture of microorganisms was grown in a nutrient solution inside a tube reactor. The content of the tube reactor was pumped through a flow channel, and biofilms were generated at the inner surfaces. Three photoacoustic sensor heads were integrated at different positions into the base plate of the flow channel. By photoacoustic spectroscopy, growth, thickness, and detachment of biofilms can be monitored on-line and nondestructively. Experiments presented in this article showed that the flow conditions influence the structure and thickness of biofilms. By changing the pH value, electrostatic interactions inside the biofilm matrix were influenced, and the subsequent detachment processes were observed online. The interaction of iron(III) oxide particles with biofilms led to particle adsorption on the outer and inner surfaces of the biofilm. Afterwards, biofilm flocs were sloughed off from the base biofilm.

Acoustics↗
PubMed2002

Determination of vitellogenin kinetics in male fathead minnows (Pimephales promelas).

A lack of knowledge persists concerning the combination of kinetics on protein and mRNA levels of the most commonly used biomarker for estrogenic influences-vitellogenin (VTG). Consequently, male fathead minnows were exposed to 17alpha-ethinylestradiol (EE(2)) for 35 days, followed by an equally long depuration period in a flow-through system. VTG mRNA levels reached a plateau after 3 days of exposure, which remained stable until 3 days after EE(2) removal. Control levels were re-attained within 7 days of the depuration phase. VTG protein accumulated in the plasma following a two-phased model. The first phase depicting an exponential increase lasted 15 days and was followed by a saturation phase approaching a plateau of approximately 47 mg VTG/ml plasma. Clearance kinetics could be described by a two-compartment open model, with half-lives of 2.17 and 21.32 days for the alpha- and beta-phases, respectively. In addition, a high VTG protein synthesis rate seemed to adversely affect fitness and mortality of the fish.

Animals↗
PubMed2001

An evaluation of Choose to Move 1999: an American Heart Association physical activity program for women.

BACKGROUND: Rates of physical inactivity and poor nutrition, which are 2 of the most important modifiable risk factors for cardiovascular disease in women, are substantial. Even so, studies of interventions designed to improve lifestyle behaviors in women have been limited and often confined to particular geographical areas. OBJECTIVE: To evaluate the effect of Choose to Move on increasing women's physical activity, improving their knowledge of heart disease and stroke, and improving their nutrition. PARTICIPANTS AND METHODS: A prospective, nonrandomized, 12-week educational intervention designed by the American Heart Association for women across the United States. Participants received a welcome kit and manual with weekly information about how to manage cardiovascular disease risk factors and how to build a support system for lifestyle change. Women (N = 23 171) aged 25 years or older were recruited by direct mail, the media, health care providers, and other means. Follow-up evaluations were returned from 6389 women at 2 weeks, 5338 at 4 weeks, 4209 at 8 weeks, 3916 at 10 weeks, and 3775 at 12 weeks. Participants self-reported their physical activity, diet, and knowledge about heart disease, stroke, and related symptoms. RESULTS: Ninety percent of the participants were white and 56% were aged between 35 and 54 years. Among the participants who completed the week 12 follow-up evaluation, the percentage who reported being active (at least moderate exercise > or =5 times per week or >2(1/2) hours per week for the past 1 to 6 months) increased from 32% at baseline to 67% at the program's end (P =.001). Participants currently limiting excess calories or fat increased from 72% to 91% at week 10 follow-up evaluation (P =.001). The proportion correctly identifying heart disease as the leading cause of death increased from 84% to 91% at week 10 follow-up evaluation (P<.001). CONCLUSIONS: Women who completed the Choose to Move program evaluation reported that they significantly increased their levels of physical activity, reduced their consumption of high-fat foods, and increased their knowledge and awareness of cardiovascular disease risk and its symptoms. This program provides an important model for public health, voluntary, and other health organizations of population-based, targeted low-cost self-help programs that support the Healthy People 2010 objectives for physical activity, nutrition, and cardiovascular health.

Adult↗
PubMed2001

Spontaneous remission in a secondary acute myelogenous leukaemia following invasive pulmonary aspergillosis.

Spontaneous remission of adult acute myelogenous leukaemia (AML) represents a rare event. We report a 60-year-old female patient suffering from secondary AML M1 and severe invasive pulmonary hyalohyphomycosis highly suggestive of aspergillosis. Two months after the diagnosis of leukaemia, she achieved a spontaneous remission lasting 3 months, although neither cytostatic drugs nor corticoids were administered because of a septic condition. At the time of remission, a chronic hepatitis C virus infection and a polyclonal hypergammaglobulinaemia were present, and the patient received granulocyte colony-stimulating factor once. This report represents the first documentation of a spontaneous remission in AML following invasive pulmonary hyalohyphomycosis. Possible mechanisms of this phenomenon are discussed.

Aspergillosis↗
PubMed2001

Detection of superficial zone protein in human and animal body fluids by cross-species monoclonal antibodies specific to superficial zone protein.

In this report we describe the purification of human superficial zone protein (SZP), the generation of cross-species monoclonal antibodies (MAbs) and the detection of this protein in human and animal body fluids. Human SZPs, used as immunizing antigens, were purified either from culture media of human cartilage organ cultures or from human synovial fluids. The immunizing antigens were mixed with RIBI adjuvant in one of three forms: nonmodified SZP, superficial zone protein-keyhole limpet hemocyanin conjugate (SZP-KLH), or a mixture of superficial zone protein and hyaluronic acid (SZP-HA). A panel of MAbs including GW4.23, S6.79, S13.52, S13.233, and S17.109 were generated and characterized. Monoclonal antibody (MAb) S6.79, an IgG2b with K(D) 3.14 x 10(-9) M from SZP-KLH immunization, is of particular interest. It reacts strongly to a large molecular weight form of SZP in both enzyme-linked immunosorbent assay (ELISA) and Western blotting. It stains the most superficial layer of articular cartilage in immunohistochemistry, whereas the middle and deep zones of cartilage are not stained. When MAb S6.79 was applied to Western blots of human body fluids, a strong 345-kDa band was detected in samples of synovial fluid and weaker bands of similar size were detected in samples of plasma and serum. MAb S6.79 also showed cross-species immunoreactivity with SZP in samples of synovial fluids harvested from bovine, dog, guinea pig, and rabbit, as demonstrated by Western blotting and antibody absorption experiments. This cross-species MAb will be a useful tool in human and animal model studies for monitoring SZP levels and tissue distribution. It may help define the roles of SZP in normal articular joints and may be of diagnostic or prognostic value for the measurement of SZP in pathological conditions such as osteoarthritis, rheumatoid arthritis, and camptodactyly-arthropathy-coxa vara-pericarditis.

Animals↗
PubMed2001

A mutation in the human MPDU1 gene causes congenital disorder of glycosylation type If (CDG-If).

We describe a new congenital disorder of glycosylation, CDG-If. The patient has severe psychomotor retardation, seizures, failure to thrive, dry skin and scaling with erythroderma, and impaired vision. CDG-If is caused by a defect in the gene MPDU1, the human homologue of hamster Lec35, and is the first disorder to affect the use, rather than the biosynthesis, of donor substrates for lipid-linked oligosaccharides. This leads to the synthesis of incomplete and poorly transferred precursor oligosaccharides lacking both mannose and glucose residues. The patient has a homozygous point mutation (221T-->C, L74S) in a semiconserved amino acid of MPDU1. Chinese hamster ovary Lec35 cells lack a functional Lec35 gene and synthesize truncated lipid-linked oligosaccharides similar to the patient's. They lack glucose and mannose residues donated by Glc-P-Dol and Man-P-Dol. Transfection with the normal human MPDU1 allele nearly completely restores normal glycosylation, whereas transfection with the patient's MPDU1 allele only weakly restores normal glycosylation. This work provides a new clinical picture for another CDG that may involve synthesis of multiple types of glycoconjugates.

Adolescent↗
PubMed2001

Transportation for maternal emergencies in Tanzania: empowering communities through participatory problem solving.

Inadequate health care and long delays in obtaining care during obstetric emergencies are major contributors to high maternal death rates in Tanzania. Formative research conducted in the Mwanza region identified several transportation-related reasons for delays in receiving assistance. In 1996, the Cooperative for Assistance and Relief Everywhere (CARE) and the Centers for Disease Control and Prevention (CDC) began an effort to build community capacity for problem-solving through participatory development of community-based plans for emergency transportation in 50 villages. An April 2001 assessment showed that 19 villages had begun collecting funds for transportation systems; of 13 villages with systems available, 10 had used the system within the last 3 months. Increased support for village health workers and greater participation of women in decision making were also observed.

Community Health Planning↗
PubMed1999

Gemcitabine--a novel immunosuppressive agent--prevents rejection in a rat cardiac transplantation model.

BACKGROUND: 2',2' -difluorodeoxycytidine (dFdC, gemcitabine) is a pyrimidine antimetabolite with antineoplastic activity against a wide range of solid tumors. The immunosuppressive activities of this compound have not been described to date. METHODS: The in vitro effects on activated T lymphocytes were studied with a lymphocyte colony-forming assay in a microagar culture system. Heart transplantations were performed in the fully allogeneic Lewis/ Brown Norway combination. dFdC was administered once daily at various dosages from the time of surgery until day 50. RESULTS: Phytohemagglutinin-induced lymphocyte proliferation was inhibited 50% by dFdC at a concentration of 3.25+/-0.9 nmol/L. Allografts of untreated animals survived for 7.5 (7-8) days and those with 25, 50, and 75 microg/kg body weight dFdC for 7.3 (7-8), 9.3 (8-10), and 16.3 (10-38) days, respectively. Treatment with 100 or 125 microg/kg body weight of dFdC, however, prolonged allograft survival until day 152.8 (129-178). Dose-dependent leukopenia was the main toxicity. CONCLUSIONS: DFdC is a new immunosuppressive agent that can successfully prevent cardiac rejection in a rat transplantation model.

Animals↗
PubMed1999

The use of ultrasound to differentiate rectus sheath hematoma from other acute abdominal disorders.

BACKGROUND: Rectus sheath hematoma (RSH) is a rare entity that can mimic an acute abdomen. Therefore, we designed a study to analyze the etiology, frequency, diagnosis using ultrasound, and treatment of RSH. METHODS: A total of 1,257 patients admitted for abdominal ultrasound for acute abdominal pain or unclear acute abdominal disorders were evaluated. RESULTS: In 23 (1.8%) patients, an RSH was diagnosed; three of them were not diagnosed preoperatively by ultrasound. Of 13 men and 10 women (mean age, 57 +/- 23 years), 13 developed RSH after local trauma, three after severe coughing, two after defecation, and five spontaneously. Fifteen had nonsurgical therapy, and eight underwent surgery. The use of anticoagulants was accompanied by a larger diameter of the RSH (p <.012), and surgical therapy was more frequently required in these patients. In the surgically treated group, more intraabdominal free fluid could be detected by ultrasound (p <.0005), patients required less analgesics (p <.001), and the mean hospital stay was shorter (p <.001). CONCLUSIONS: RSH is a rare condition that is usually associated with abdominal trauma and/or anticoagulation therapy. Ultrasound is a good screening technique. Nonsurgical therapy is appropriate but leads to a greater need for analgesics. Surgery should be restricted to cases with a large hematoma or free intraabdominal rupture.

Abdomen, Acute↗
PubMed1999

Pulmonary Aspergillus colonization in humans and its impact on management of critically ill patients.

Samples of lung tissues were obtained and analysed for Aspergillus carriage in 56 patients undergoing thoracic surgical intervention and 18 people who had an unexpected death. Out of 74 samples, 46 (63%) had evidence of pulmonary fungal colonization. The surgery population had a rate of 62% of fungal growth. Aspergillus was present in 39%. The autopsy population had a rate of 61% of fungal colonization. Aspergillus was present in 41%. In these cases eradication of fungal spores residing in the lung prior to aggressive chemotherapy and prevention of further spore uptake during hospitalization is indispensable in preventing pulmonary aspergillosis.

Aspergillosis↗
PubMed1999

[Aneuploidy detection by multi-color fluorescence in situ hybridization in mouse sperm].

Multi-color fluorescence in situ hybridization (FISH) was employed to evaluate the frequency of aneuploid sperm in young adult mice after treated by 2-(4'-thiazolyl) benzimidazole or thiabendazole (TB). The animals were given TB (100 200 300 mg/kg) by oral incubation daily for 11 days, and sacrificed 22 days after the last treatment of TB. Three-chromosome FISH was applied to determine the frequencies of diploid, disomic and nullisomic sperm with DNA probes specific for the chromosomes X, Y and 8. The aneuploid frequencies were not significantly different between the sperm in 100 mg/kg group and solvent control. The frequencies aneuploid and diploid sperm in middle dose group were significantly higher than the solvent control (P < 0.001-0.05). There were no significant aneuploid frequency increases were found in 300 mg/kg group excepting the frequency of diploid sperm. It is conclude that TB is a potential germinal aneugen in mammalian, which may block the cleavage during the meiosis. Epididymal sperm aneuploidy can be reliably determined by sperm FISH analysis in mice.

Aneuploidy↗
PubMed1998

Intraurethral ultrasound correlated with urethral histology.

OBJECTIVE: To examine the anatomic identity of sonographically visible sphincteric structures of the female urethra. METHODS: The urethra, urinary bladder, and vagina were removed from 11 fresh female cadavers and placed in a water bath. Intraurethral ultrasound was performed with a 360 degrees-rotating 7.5-MHz ultrasound probe. Afterward, the specimens were fixed and cross sections were made transverse to the urethral axis at 5-mm intervals. Corresponding ultrasonograms and histologic images were matched and depicted simultaneously side by side. The anatomic identity of sonographically visible structures was determined by histologic examination and thickness of the longitudinal smooth urethral sphincter measured. RESULTS: Structures visible sonographically were the striated and smooth urethral sphincter muscle layers, vagina, and blood vessels with diameters exceeding 0.2 mm. The longitudinal smooth muscle layer appeared as a well-defined internal hypoechoic ring. The outer circular smooth muscle layers and the striated muscle layers were a more irregular and hyperechoic zone. The circular smooth muscle layers and the striated sphincter muscle layers could not always be differentiated easily. With formalin fixation, tissue shrinkage resulted in a smaller thickness of the longitudinal smooth muscle measured on the histologic specimen. CONCLUSION: With intraurethral ultrasound, the longitudinal smooth muscle layer appears as a well-defined and measurable hypoechoic ring. The region of the circular smooth muscle and the striated muscle emerges as a hyperechoic and less definable outer zone.

Adult↗
PubMed1998

Closure of complex defects in the chest wall with muscle flaps.

Aggressive treatment of thoracic malignancy may be complicated by complex defects in the chest wall. These may be associated with serious complications such as chronic infection, respiratory or cardiac failure, or major haemorrhage. Closure of the defect and restoration of the integrity of the chest wall is important for both functional and cosmetic reasons. Local flaps are often used, but may be inadequate or unavailable. Reconstruction with free flaps is better in these cases, as this provides as much abundant well-vascularised tissue as is required. We present 12 patients treated successfully for complex chest wall defects using various forms of local and free flap reconstruction. There were five complications, three healed spontaneously and two required secondary procedures before they healed.

Adult↗
PubMed1998

2-Chlorodeoxyadenosine (cladribine) in combination with low-dose cyclosporin prevents rejection after allogeneic heart and liver transplantation in the rat.

The purine analogue 2-chlorodeoxyadenosine (2-CDA) has been shown to possess synergistic immunosuppressive properties when given together with cyclosporin (CSA) in a rat small bowel transplant model. The present study investigated the immunosuppressive potency of 2-CDA alone and in combination after liver or heart transplantation in a fully allogeneic rat model with 5 animals in each group. Immunosuppression was provided with CSA 10 mg/kg body weight (BW)/day orally or 2-CDA 0.1 mg/kg/BW day intravenously or both compounds together in the dosages mentioned. Animals were sacrificed on day 10 following transplantation, and graft histology was assessed. In addition, cardiac graft function was evaluated by palpation immediately prior to sacrificing the animal. CSA given alone was able to mitigate but not prevent rejection. 2-CDA alone did not exhibit any detectable immunosuppressive effect. When CSA was combined with 2-CDA, no rejection was seen in 80% of the liver allografts and in 60% of heart allografts, and only mild rejection was observed in the remaining animals. All hearts of the combined treatment group, however, beat strongly. From these findings it is concluded that 2-CDA alone has no, but together with CSA a strong immunosuppressive effect in preventing solid organ allograft rejection.

Animals↗
PubMed1998

[Total thyroidectomy in iodine-deficient goiter--an effective treatment alternative?].

It can be difficult to define the extent of struma resection because of large multinodular transformation. The total thyroidectomy of goiter is refused due to a supposed increase in complications. A high rate of goiter recurrence together with higher risks of complications demonstrates the problems of insufficient resection. This study investigates the rate of complications of total thyroidectomy of goiter. 4767 surgical treatments (partial thyroidectomy, hemithyroidectomy or total thyroidectomy) of goiter were investigated. Retrospectively the rate of postoperative complications (hemorrhage, wound infection, recurrent nerve palsy, hypocalcemia) after strumectomy or hemithyroidectomy was analysed in our patients and compared with the data of the literature. Total thyroidectomy (n = 176) did not cause a higher rate of complications (hemorrhage: 0.6%, hypocalcemia: 0.6%; recurrent nerve palsy: 0.6%) compared to the control group and the literature. Thus, total thyroidectomy can offer an efficient therapeutic option in large multinodular goiter.

Adult↗