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Biomedical subjects

A Kunz

Publications and source records attributed to A Kunz.

At least 19 recordsLinked to original sources
PubMed2005

De Quervain's subacute thyroiditis -- colour Doppler sonography findings.

AIM: De Quervain's subacute nonsuppurative thyroiditis has been well characterised clinically: there usually is pain in the region of the thyroid due to local pressure. Typically, the patient feels generally ill with fever. Signs of inflammation (raised ESR and CRP) are measurable laboratory parameters. Occasionally, there is transient hyperthyroidism followed by hypothyroidism. Little data is available on the vascularisation of the thyroid in this clinical entity. PATIENTS AND METHODS: Twenty-one patients with confirmed De Quervain's subacute thyroiditis were investigated and the findings were analysed retrospectively (clinical features, sonography, cytology in some cases). Ultrasound devices (Siemens Elegra and Acuson Sequoia) with 7 and 12 MHz ultrasound transducers and modern technology (harmonic imaging, panorama imaging and sensitive colour Doppler units with standardised instrument settings) were used. RESULTS: The structures of the thyroid was found to be inhomogeneous. The hypoechoic to nonechoic areas corresponded to the inflamed areas. An alteration in the morphology and topographic distribution was observed in the course of the illness. Normal or slightly increased vascularisation in the echogenically "healthy" regions of the thyroid were found in colour Doppler sonography. The peak systolic velocity (PSV) in the afferent arteries (superior and inferior thyroid arteries) was in the normal range (< 40 cm/s). The hypoechoic/nonechoic map-like areas showed a reduction or complete absence of blood flow. CONCLUSION: De Quervain's subacute thyroiditis can be conclusively diagnosed by sonography in more than 90 % of cases based on the history, typical clinical features and clinical test parameters indicating signs of inflammation. Colour Doppler sonography can be useful in differential diagnosis of unclear cases.

Acute Disease↗
PubMed2004

[Prevalence of hantavirus infections in Germany].

Hantaviruses belong to the group of "emerging" viruses. Pathogenic European hantaviruses can cause a human disease designated "hemorrhagic fever with renal syndrome" of varying severity. In general, diagnostics of hantavirus infections are based on immunofluorescence assays using virus-infected cells or enzyme immunoassays and Western blot tests using recombinant nucleocapsid proteins. For highly sensitive detection of hantavirus-specific antibodies in the enzyme immunoassay, a homologous hantavirus nucleocapsid protein is needed as a diagnostic antigen. Serological typing of hantavirus infections can be obtained by neutralization assays, which in certain cases require the use of late convalescent sera. The seroprevalence in the normal German population is about 1%. In professionally exposed risk groups, e. g., forest workers, a seroprevalence higher than that in the normal population was observed. Endemic regions for hantavirus infections are located mainly in Baden-Württemberg. In the years 2001-2003 an annual number of about 200 clinically apparent hantavirus infections were registered in Germany. Neutralization assays detected almost exclusively human infections caused by Puumala and Dobrava viruses, only very rarely by Tula virus. Until this day in Germany mainly mild to moderate courses of human hantavirus infections have been documented. Besides infections caused by "German" hantaviruses, up to 10% of the clinically apparent hantavirus infections registered annually in Germany are caused by infections imported from other countries, mainly from Europe. So far only very limited molecular genetic data about the circulating hantaviruses in Germany are available. Additional investigations are needed to get a more precise picture about the distribution of hantaviruses in Germany and to calculate the resulting risk for the human population.

Communicable Disease Control↗
PubMed2003

Acute double-blind, placebo-controlled sleep laboratory and clinical follow-up studies with a combination treatment of rr-L-dopa and sr-L-dopa in restless legs syndrome.

In a double-blind, placebo-controlled randomized crossover trial, the acute efficacy of a combination treatment of 100 mg regular-release (rr) and 100 mg sustained-release (sr) L-dopa/benserazide in RLS was investigated by means of sleep laboratory methods, with a subsequent open clinical follow-up for 4 weeks. 21 RLS patients classified according to ICSD and IRLSSG criteria were included; 18 completed the study. Objective sleep quality was determined by polysomnography (PSG) in 3 subsequent nights (adaptation/screening, placebo and drug night), subjective sleep and awakening quality was evaluated by rating scales, objective awakening quality by psychometric tests. Clinical follow-up consisted of daily ratings of subjective sleep and awakening quality (SSA) and VAS for RLS symptomatology ratings, completion of the RLS (IRLSSG) Scale weekly and the Zung Depression (SDS) and Anxiety (SAS) Scale, Quality of Life Index, Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale before and after therapy. Acute L-dopa/benserazide significantly (p < 0.001) and markedly (75%) decreased the target variable PLM/h of sleep as well as all other RLS/PLM variables, but failed to improve objective sleep efficiency and subjective sleep quality in comparison to placebo. After 4 weeks of therapy, however, subjective sleep and awakening quality also improved significantly. While RLS/PLM measures showed an immediate significant and marked response to the combination therapy subjective sleep quality only improved after chronic treatment.

Adult↗
PubMed2002

2,3,7,8-tetrachlorodibenzo-p-dioxin-dependent release from contact inhibition in WB-F344 cells: involvement of cyclin A.

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is the most potent tumor promoter ever tested in rodents. Although it is known that most of TCDD actions are mediated by binding to the aryl hydrocarbon receptor (AhR), the mechanisms leading to tumor promotion still remain to be elucidated. Loss of contact inhibition is one characteristic hallmark in tumorigenesis. In rat liver epithelial WB-F344 cells, TCDD induces a release from contact inhibition, which is manifested by a twofold increase in cell number when TCDD (1 nM for 48 h) is added to confluent cells in the presence of serum, but not when given to exponentially growing or subconfluent, serum-deprived WB-F344 cells. Loss of G1 arrest was also shown by flow cytometric analysis. We demonstrate that TCDD treatment significantly increases cyclin D2 and cyclin A protein levels and show by immunofluorescence that these proteins accumulate in the nucleus. Although TCDD treatment leads to a strong increase in cyclin D2/cdk4 and cyclin A/cdk2 complex formation, we could only detect an elevation of cyclin A/cdk2 activity. In accordance with a lack of elevated cdk4 activity, no decrease in the amount of hypophosphorylated retinoblastoma protein could be shown after TCDD treatment. The importance of increased cyclin A/cdk2 activity for TCDD-dependent release from contact inhibition was shown by the fact that the cdk2/cdc2-specific inhibitor olomoucine (25 microM) abolished TCDD response. These data indicate cyclin A-dependent loss of G1 arrest after TCDD treatment mainly downstream of the retinoblastoma protein.

Animals↗
PubMed2002

[Epidemic nephropathy. An important differential diagnosis of acute renal failure in Reutlingen, an endemic area].

BACKGROUND AND OBJECTIVE: Hantavirus ("epidemic") nephropathy (HN), or hemorrhagic fever with renal syndrome (WHO nomenclature), is an infection caused by strains (e.g. Puumala) of Hantavirus, which is often accompanied by acute renal failure. Although its typical symptomatology has been fully reported, it is rarely included in the differential diagnosis of renal nephropathy. This study investigated whether, in the presence of typical symptoms, specific search for a certain constellation of laboratory values in association with a typical history can more often provide the diagnosis of HN. PATIENTS AND METHODS: 18 patients (4 females, 14 males; average age 41 years) fulfilled the following inclusion criteria: abnormal values for creatinine, LDH and C-reactive protein, proteinuria and hematuria, as well as thrombocytopenia in conjunction with fever, back- and headache. After the diagnosis had been confirmed by demonstrating antibodies against the Puumala strain of hantavirus, follow-up included laboratory tests and clinical observation. RESULTS: All patients fully recovered without any sequelae. There was a clearly increased frequency of cases at the Reutlingen Clinic compared with the previous years (maximally 7 cases per year in 1995-1999). The incidence in the Reutlingen region was probably at least 6.5/100 000 inhabitants. CONCLUSION: At least in endemic regions HN is one of the most common causes of acute renal failure. The increase of cases can, among other reasons, be explained by the described prospective diagnostic schema. But climatic factors with changes in the density of the vector (bank vole) cannot be excluded.

Acute Kidney Injury↗
PubMed2002

A degradation and toxicity study of three textile reactive dyes by ozone.

Textile reactive dyes are very recalcitrant to biodegradation, causing aesthetic, acute and chronic toxicity problems in receiving waters. In this study, we present the degradation of three different reactive dyes (Reactive Black 5, Reactive Blue 19 and Reactive Blue 21) by ozone, at two different pH conditions. The ozonation process achieved a very fast decoloration rate for the studied dyes. The influence of pH in the ozonation of these dyes was only significant for Reactive Black 5. The toxicity of dyes, after pre-treatment, was evaluated using Vibrio fisheri (microtox). There was little change in toxicity for Reactive Black 5, but there was a reduction for Reactive Blue 19. A significant increase in toxicity for Reactive Blue 21 was verified, caused by the increase in the bioavailability of th e cooper ion that was in the complexed form before the treatment with ozone.

Animals↗
PubMed2001

[Autoimmune pancreatitis (AIMP) - a clinical entity of its own?].

HISTORY AND ADMISSION FINDINGS: A 34-year-old man with chronic inflammation of both tear glands for 10 years was admitted because of severe upper abdominal pain and jaundice. INVESTIGATIONS: Transaminase and cholestasis parameters were raised, as were gamma-globulins on electrophoresis. Ultrasound revealed an echo-poor diffusely enlarged pancreas with hypervascularity on colour-Doppler. Endoscopic retrograde cholangiopancreatography (ERCP) indicated chronically changed pancreatic ducts of varying diameter and stenosis, as well as a filiform distal stenosis of the common bile duct. A pancreatic biopsy showed chronic sclerosing pancreatitis with broad periductal lymphocytic infiltration. TREATMENT AND COURSE: ERCP and a guide-wire papillotomy were performed, followed by placement of a nasobiliary catheter. All findings markedly improved on oral prednisone. CONCLUSION: This case supports the supposition that in idiopathic chronic pancreatitis autoimmune processes may be responsible for the changes in the pancreatic ducts. Immunosuppressive treatment is thus recommended in these cases.

Administration, Oral↗
PubMed2001

Combined treatment of textile effluent using the sequence Phanerochaete chrysosporium-ozone.

Textile effluents cause a high environmental impact when released into the environment without correct treatment. In this work, we have evaluated the capacity of treatment of a textile effluent using a biological and a chemical method using the sequence Phanerochaete chrysosporium-ozone. The fungal treatment was performed by direct incubation of a fungus spore suspension in textile effluent for nine days. Then, the effluent was ozonized at pH 11 and room temperature. Color, total organic carbon, molecular mass distribution and total phenols were determined. In biological experiments, enzymatic activity (lignin peroxidase, manganese peroxidase and laccase) were also monitored. Toxicity tests were carried out with Scenedesmus subspicatus and with Escherichia coli. Good decoloration, total phenols reduction and textile effluent molecular mass reduction were obtained during the process. No significant total organic carbon reduction was observed. The toxicity of the textile effluent was reduced with both test organisms showing no inhibition at the end of the treatment.

Biodegradation, Environmental↗
PubMed2001

Kinetic studies on veratryl alcohol transformation by horseradish peroxidase.

A number of peroxidases, such as lignin peroxidase and manganese peroxidase have proved to be useful for industrial applications. Some studies on the effects of temperature and pH stability have been carried out. It is known that veratryl alcohol increases their stability in the range 28-50 degrees C and is oxidized, leading to veratryl aldehyde formation. Similar results with horseradish peroxidase (HRP) in the presence of cofactors were found, but the oxidation of veratryl alcohol in the absence of cofactors was extremely labile at acid pH and inactivated in a few minutes. Considering the growing industrial application of HRP, knowledge of its stability and denaturation kinetics is required. In this study, horseradish peroxidase pool (HRP-VI) and its isoenzymes HRP-VIII (acid) and HRP-IX (basic) have been shown to catalyze the oxidation of veratryl alcohol to veratryl aldehyde in the presence of hydrogen peroxide at pH 5.8 in the 35-45 degrees C range and in the absence of any cofactors. Heat and pH denaturation experiments in the presence and absence of veratryl alcohol incubation were conducted with HRP-VI and HRP-IX isoenzymes. HRP-IX was the most active isoenzyme acting on veratryl alcohol but HRP-VI was the most stable for the temperature range tested. At 35 degrees C the HRP pool presented decay constant (Kd) values of 5.5 x 10(-2) h(-1) and 1.4 10(-2) h(-1) in the absence and presence of veratryl alcohol, respectively, with an effective ratio of 3.9. These results present a new feature of peroxidases that opens one more interesting application of HRP to industrial processes.

Benzyl Alcohols↗
PubMed2001

Nitric oxide from perivascular nerves modulates cerebral arterial pH reactivity.

In the isolated rat middle cerebral artery (MCA) we investigated the role of nitric oxide (NO)/cGMP in the vasodilatory response to extraluminal acidosis. Acidosis increased vessel diameter from 140 +/- 27 microm (pH 7.4) to 187 +/- 30 microm (pH 7.0, P < 0.01). NO synthase (NOS) inhibition by N(omega)-nitro-L-arginine (L-NNA, 10 microM) reduced baseline diameter (103 +/- 20 microm, P < 0.01) and attenuated response to acidosis (9 +/- 8 microm). Application of the NO-donors 3-morpholinosydnonimine (1 microM) or S-nitroso-N-acetylpenicillamine (1 microM), or of 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP, 100 microM) reestablished pre-L-NNA diameter at pH 7.4 and reversed L-NNA-induced attenuation of the vessel response to acidosis. Restoration of pre-L-NNA diameter (pH 7.4) by papaverine (20 microM) or nimodipine (30 nM) had no effect on the attenuated response to acidosis. Guanylyl cyclase inhibition with 1H-[1,2,4]oxadiazolo[4,3-a]-quinoxalin-1-one (5 microM) or NOS-inhibition with 7-nitroindazole (7-NI, 100 microM) reduced baseline vessel diameter (109 +/- 8 or 127 +/- 11 microm, respectively) and vasodilation to acidosis, and restoration of baseline diameter with 8-BrcGMP (30 microM) completely restored dilation to pH 7.0. Chronic denervation of NOS-containing perivascular nerves in vivo 14 days before artery isolation significantly reduced pH-dependent reactivity in vitro (diameter increase sham: 48 +/- 14 microm, denervated: 14 +/- 8 microm), and 8-BrcGMP (30 microM) restored dilation to pH 7.0 (denervated: 49 +/- 31 microm). Removal of the endothelium did not change vasodilation to acidosis. We conclude that NO, produced by neuronal NOS of perivascular nerves, is a modulator in the pH-dependent vasoreactivity.

Acidosis↗
PubMed2001

Echo-enhanced transcranial color-coded duplexsonography to study collateral blood flow in patients with symptomatic obstructions of the internal carotid artery and limited acoustic bone windows.

We prospectively evaluated 30 consecutive patients with echo-enhanced transcranial color-coded duplexsonography (TCCD) and correlative transfemoral digital subtraction angiography to assess the diagnostic efficacy of echo-enhanced TCCD for evaluation of collateral pathways through the circle of Willis in patients with limited acoustic bone windows and critical symptomatic carotid disease. Echo-enhanced TCCD detected collateral blood flow through the anterior communicating artery in 16 of 18 patients (sensitivity 89%, 95% CI 65-99%) and was false positive in one out of 12 patients without collateral flow (specificity 92%, 95% CI 59-100%). For the posterior communicating artery, sensitivity was 11/14 (79%, 95% CI 49-95%) and specificity was 15/16 (94%, 95% CI 70-100%). Echo-enhanced TCCD enables to study collateral blood flow through the communicating arteries of the circle of Willis with high sensitivity and specificity in patients with obstructions of the internal carotid artery and limited acoustic bone windows.

Aged↗
PubMed1999

Degradation of reactive dyes I. A comparative study of ozonation, enzymatic and photochemical processes

The environmental problems associated with textile activities are represented mainly by the extensive use of organic dyes. A great number of these compounds are recalcitrant and shown carcinogenic or mutagenic character. In this work three processes were studied for degradation of an anthraquinone dye (C.I. reactive blue-19). The ozonation process leads to complete decolorization with a very short reaction time; however, effective mineralization of the dye was not observed. The enzymatic process promotes quick decolorization of the dye; nevertheless, maximum decolorization degrees of about 30% are insignificant in relation to the decolorization degree achieved by the other processes. The best results were found for the photocatalytical process. The use of ZnO or TiO2 as photocatalysts, permits total decolorization and mineralization of the dye with reaction times of about 60 min.

Journal Article↗
PubMed1998

Dihydroramulosin from Botrytis sp.

Botrytis sp., isolated from the inner bark of the Pacific yew, Taxus brevifolia, was shown to produce ramulosin (1), 6-hydroxyramulosin (2), and the new compound 8-dihydroramulosin (3). The structure of dihydroramulosin was deduced from the NMR spectra and confirmed by chemical conversion from ramulosin.

Anti-Bacterial Agents↗
PubMed1997

Calicheamicin derivatives conjugated to monoclonal antibodies: determination of loading values and distributions by infrared and UV matrix-assisted laser desorption/ionization mass spectrometry and electrospray ionization mass spectrometry.

Calicheamicin derivatives (MW approximately 1500) and monoclonal antibodies (MoAbs) conjugated to calicheamicin derivatives (MW approximately 150,000) were analyzed by UV-MALDI/MS, IR-MALDI/MS, and ESI/MS. These materials are potent anticancer agents. Calicheamicin derivatives and conjugates rapidly degrade upon UV irradiation but are relatively stable during IR irradiation and under ESI conditions. A unique feature of IR-MALDI/MS is a 2 times enhancement in resolution relative to UV-MALDI/MS for masses above approximately 50,000 Da resulting in a molecular ion envelope containing a series of partially resolved peaks of the calicheamicin-MoAb conjugates. The mass shift difference between the peak maxima corresponded to the mass change due to the covalent addition of calicheamicin derivatives to the monoclonal antibody. The distribution of the calicheamicin derivatives in the monoclonal antibodies was computed by deconvoluting the partially resolved peak envelope. A unique feature of the ESI mass spectra, under unit resolution conditions, is that the distribution of the carbohydrates can be well resolved for pure MoAbs and can be only partially resolved for conjugated MoAbs. Average loading values for calicheamicia derivatives when conjugated to MoAbs were computed from UV-MALDI/MS, IR-MALDI/MS, and ESI/MS data and the results compared with the average loading values obtained by UV absorption spectrometry. Very low average loading values were computed from UV-MALDI/MS data due to the degradation of the conjugated calicheamicin derivatives during the UV irradiation process. The IR-MALDI/MS average loading values, obtained with glycerol as the matrix, were consistent with the UV absorption spectrometry values for conjugates having hydrolytically stable linkers, but not when the linker contained a hydrolytically labile hydrazone. ESI/MS average loading values were generally lower than the corresponding values obtained by IR-MALDI/MS. The average loading values and distributions obtained using IR-MALDI/MS were more reliable than the corresponding ESI/MS values because the partially resolved, singly and doubly charged peaks in the IR-MALDI spectra can be mathematically deconvoluted, while the overlapping, highly multiply charged peaks of the electrospray spectra can only be partially deconvoluted.

Aminoglycosides↗
PubMed1992

Microheterogeneity of a purified IgG1 due to asymmetric Fab glycosylation.

A murine monoclonal anti-granulocyte IgG1, IMMU-MN3, was seen to exhibit heterogeneity. On reduced SDS-PAGE, the purified antibody appeared as two heavy-chain bands of unequal intensity, and only one light-chain band. Hydrophobic interaction chromatography (HIC) also resolved two populations of the IMMU-MN3 antibody. Based on Concanavalin A affinity chromatography, enzymatic digestion with Endoglycosidase F and carbohydrate analysis, it was found that the heterogeneity detected by SDS-PAGE and HIC was due to differences in glycosylation. Furthermore, sequential gel analysis (non-reduced/reduced) demonstrated that the upper heavy-chain band was asymmetrically glycosylated.

Animals↗
PubMed1991

[Glycosylated hemoglobin and diabetes--self monitoring (compliance) in depressed and non-depressed type I diabetic patients].

128 type I diabetics were examined in view of connections between psychosocial factors and metabolic control. Indications of a direct interaction between depressivity, incidence of complaints and the level of hyperglycemia were found. The prevalence of manifest depression ranges at a total of 25 percent. The results further show connections between coping with the disease and behavior. High recording frequency, frequent measurements and medical consultations are found in active coping. Changes in relations to close persons and frequent change of job are psychosocial effects of the disease manifesting themselves in poorer metabolic control. In conclusion, high-risk groups of depressive diabetes patients and those under particular stress are defined.

Adaptation, Psychological↗
PubMed1990

Preclinical evaluation of an "instant" 99mTc-labeling kit for antibody imaging.

This communication presents information on the quality and stability of a new conjugate of 99mTc to an anticancer antibody fragment and results of animal imaging and distribution studies. Clinical studies have proved that this labeled antibody can image tumors within 2 hours of i.v. injection. It is produced using an "instant kit," merely requiring addition of [99mTc]pertechnetate to a lyophilized vial containing the fragment and a pertechnetate-reducing agent. Within 5 min of addition of pertechnetate to the vial containing the fragment, [99mTc]pertechnetate is reduced and quantitatively bound to an intrinsic high-affinity receptor present in the Fab'. The Fab'-bound 99mTc is completely stable to challenge with diethylenetriaminepentaacetic acid and human serum albumin. Minimal oxidation and release of 99mTc bound to the fragment were observed when the labeled fragment was incubated for 24 h at 37 degrees C. Animal biodistribution studies were consistent with the known metabolic elimination of a radiolabeled Fab' fragment by the kidney. Tumor localization studies in athymic nude mice bearing xenografts of human colonic carcinoma (GW-39) predicted the positive results later demonstrated in clinical studies.

Animals↗