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Biomedical subjects

J Straub

Publications and source records attributed to J Straub.

At least 19 recordsLinked to original sources

International Staging System required standardization of biochemical laboratory testing in multiple myeloma.

The standardization of biochemical measurement procedures in multiple myeloma is necessary for reliable prognostic stratification of patients in multicentric trials. The new prognostic index International Staging System for multiple myeloma uses only two laboratory markers, albumin and beta-2 microglobulin. Our study compared results of albumin, beta-2 microglobulin and monoclonal immunoglobulin measurements from six centers which provide treatment for multiple myeloma in the Czech Republic and attempted to standardize the analytic procedures. We have found that the measurement of albumin is well standardized and the results from all laboratories were comparable. The measurement of beta-2 microglobulin achieved comparability only after a partial unification of analytical methods. The determination of monoclonal immunoglobulin concentration provided comparable results for concentrations higher than 20 g/l with higher variability for lower values.

Antibodies, Monoclonal↗

[Schistosomiasis in a leiomyoma of the uterus].

This case report deals with an, in our regions, unusual diagnosis of coincidence of a genital schistosomiasis of a 30-year-old woman, coming from Africa. The female patient presented herself by a specialist because of longer lasting hypermenorrhoe. After clinical examination the patient underwent an operation because of an uterus myomatosus. The histopathological evaluation showed beside a leimyoma an expanded infestation with schistosomiasis haematobium. After pathological diagnosis the patient underwent the standard therapy with a single injection of praziquantel. We report about the clinic, epidemiology, morphology and diagnostic.

Adult↗

[Pilot study of echocardiographic studies using color- and pulsed-wave spectral Doppler methods in blue-crowned amazons (Amazona ventralis) and blue-fronted amazons (Amazona a. aestiva)].

Colour-flow and pulsed-wave spectral Doppler echocardiography was performed on 6 healthy, adult Hispaniolan amazon parrots (Amazona ventralis) and 6 blue-fronted amazon parrots (Amazona a. aestiva) to establish normal reference values. Birds were anesthetized with isoflurane in oxygen and placed in dorsal recumbency. An electrocardiogram was recorded continuously and birds were imaged with a micro-phased-array scanner with a frequency of 7.0 MHz. After assessment of cardiac function in 2-D-echocardiography, blood flow across the left and the right atrioventricular valve and across the aortic valve was determined using color-flow and pulsed-wave spectral Doppler echocardiography. Diastolic inflow (mean value +/- standard deviation) into the left ventricle was 0.17 +/- 0.02 m/s (Hispaniolan amazons) and 0.18 +/- 0.03 m/s (Blue fronted amazons). Diastolic inflow into the right ventricle was 0.22 +/- 0.05 m/s (Hispaniolan amazons) and 0.22 +/- 0.04 m/s (Blue fronted amazons). Velocity across the aortic valve was 0.84 +/- 0.07 m/s (Hispaniolan amazons) and 0.83 +/- 0.08 m/s (Blue fronted amazons). Systolic pulmonary flow could not be detected in any of the birds in this study. No significant differences were evident between the two species examined. Results of this study indicate that Doppler echocardiography is a promising technique to determine blood flow in the avian heart. Further studies in other avian species are needed to establish reference values for assessment of cardiac function in diseased birds.

Amazona↗

[Bortezomib (Velcade) in relapsed/refractory multiple myeloma--the first experience in the Czech Republic].

BACKGROUND: Multiple myeloma is the second most prevalent and mostly fatal hematologic cancer. Further advances have been made in understanding the mechanisms involved in the myeloma pathogenesis and elucidation of critical signalling pathways as therapeutical targets. Proteasome inhibitors are the example of this new approach and bortezomib is the first agent in this class to enter clinical trials. METHODS AND RESULTS: In 6 hematological centers in Czech Republic 29 patients with refractory/relapsed myeloma had been treated with bortezomib (Velcade, Millennium Pharmaceuticals) in 2004. The initial dose 1.3 mg/m2 of Velcade was given, in 1 case the dose was adjusted due to pre-existing renal failure to 1 mg/m2. The response was achieved in 17 patients (59%). Four patients had complete, 11 partial and two minor responses. In 5 cases stabilization of disease was observed and 6 patients progressed during the therapy. CONCLUSIONS: Unfortunately, one patient died immediately after the start of therapy due to sepsis. The most common adverse events were thrombocytopenia, anaemia, neuropathy, gastrointestinal complication, renal failure and fatigue. Grade 4 adverse events occurred in 37.9% of patients (4x thrombocytopenia, 2x gastrointestinal, 2x renal failure, 1x sepsis, leucopenia, hepatopathy and anaemia, respectively). Peripheral neuropathic pain of grade 3 was reported in 4 cases, in one patient therapy had to be interrupted due to this complication. We confirmed promising results of phase II trials.

Adult↗

Echocardiographic examinations of 60 African grey parrots and 30 other psittacine birds.

The aim of this study was to establish reference values for the assessment of cardiac function in birds by measuring structures in the heart of healthy psittacine birds; 60 grey parrots, 10 Amazon parrots, 10 cockatoos and 10 Senegal parrots were anaesthetised with isoflurane and examined echocardiographically. The heart was visualised in two planes (vertical and horizontal views). Depending on the quality of the images, several dimensions of the heart could be measured and various parameters calculated. On the basis of these values, it was possible to establish reference values for each parrot genus. Some relative parameters showed no significant difference between the genera, independent of the bird's size.

Animals↗

Pulsed-wave Doppler echocardiography in birds of prey.

Pulsed-wave spectral Doppler echocardiography was applied to 111 diurnal and nocturnal raptors of both sexes weighing between 190 and 4200 g. In the first stage, 40 birds were examined without special preparation; in the second stage, 15 birds were examined first when they were not anaesthetised and then when they were anaesthetised; in the third stage, 41 birds were examined after they had been fasted for different periods of time; and finally 15 birds, in which echocardiography had not been possible by using standard (dorsal) restraint and positioning, were examined after being placed in lateral and ventral recumbency. Doppler-derived diastolic inflow into the ventricles was detectable in approximately 80 per cent of the birds weighing between 190 and 2300 g independently of their weight, heart rate and whether they had been anaesthetised or fasted, and aortic blood flow was detected in about 50 per cent of them. It was possible to apply the technique under standard conditions of dorsal recumbency to only one of the birds weighing more than 3000 g and to about 80 per cent of those weighing between 190 and 2300 g. In 11 of 15 birds in which the technique could not be applied under standard conditions, blood flow could be detected in the ventricles and/or the aorta after the birds had been repositioned. No systolic blood flow through the pulmonary artery was detectable in any of the birds.

Anesthesia↗

Effect of handling-induced stress on the results of spectral Doppler echocardiography in falcons.

In order to evaluate the effects of habituation to handling on the Doppler-derived velocity of diastolic ventricular inflow and systolic aortic outflow, falcons that were accustomed to regular handling were compared with falcons that had been handled very little. The mean heart rate of the frequently handled birds was 111 beats per minute less than the non-habituated birds. All the mean blood flow velocities recorded were much higher in the non-habituated birds than those accustomed to handling. Taking into account the difficulty of objectively quantifying the level of stress suffered by any individual bird, the question is, if meaningful clinical or reference values for Doppler-derived blood flow velocities may be obtained in unsedated or non-anaesthetized birds?

Animals↗

Morphometry of the heart of budgerigars (Melopsittacus undulatus), Alisterus parrots (Alisterus s scapularis) and common buzzards (Buteo buteo).

In order to establish data and reference values for the thickness of the myocardium and the length of the left and the right ventricle of the avian heart, the hearts of 14 budgerigars (Melopsittacus undulatus), five Alisterus parrots (Alisterus s scapularis) (also known as Australian king parrot) and 10 common buzzards (Buteo buteo) of both sexes were examined according to a standard protocol. In order to compare the results of birds of different sizes all data were related to the size of the bird's body (length of the sternum) and the results of the measurements of the myocardial thickness in relation to the length of the heart. Results of different zones were compared by means of statistical methods within one species. Besides that a comparison between the different species was performed. Only minor significant differences were noted.

Animals↗

Thermocapillary convection around gas bubbles: an important natural effect for the enhancement of heat transfer in liquids under microgravity.

In the presence of a temperature gradient at a liquid-gas or liquid-liquid interface, thermocapillary or Marangoni convection develops. This convection is a special type of natural convection that was not paid much attention in heat transfer for a long time, although it is strong enough to drive liquids against the direction of buoyancy on Earth. In a microgravity environment, however, it is the remaining mode of natural convection and supports heat and mass transfer. During boiling in microgravity it was observed at subcooled liquid conditions. Therefore, the question arises about its contribution to heat transfer without phase change. Thermocapillary convection was quantitatively studied at single gas bubbles in various liquids, both experimentally and numerically. A two-dimensional mathematical model described in this article was developed. The coupled mechanism of heat transfer and fluid flow in pure liquids around a single gas bubble was simulated with a control-volume FE-method. The simulation was accompanied and compared with experiments on Earth. The numerical results are in good accordance with the experiments performed on Earth at various Marangoni numbers using various alcohols of varying chain length and Prandtl numbers. As well as calculations on Earth, the numerical method also allows simulations at stationary spherical gas bubbles in a microgravity environment. The results demonstrate that thermocapillary convection is a natural heat transfer mechanism that can partially replace the buoyancy in a microgravity environment, if extreme precautions are taken concerning the purity of the liquids, because impurities accumulate predominantly at the interface. Under Earth conditions, an enhancement of the heat transfer in a liquid volume is even found in the case where thermocapillary flow is counteracted by buoyancy. In particular, the obstructing influence of surface active substances could be observed during the experiments on Earth in water and also in some cases with alcohols.

Journal Article↗

[About type and incidence of heart disease in psittacines kept in captivity in Germany].

It was the aim of the study to get an overview about spectrum and incidence of pathological aberrations in hearts and proximal vessels of psittacines which are kept in captivity in Germany. 107 psittacines which had been sent for routine necroscopy were examined especially for evidence of pathological alterations of the heart and/or the proximal vessels. In 36.4% of these birds macroscopic alterations could be verified. 99.0% of all hearts examined resp. proximal vessels showed at least mild histological alterations. This study allocates that especially noninfectious heart disease is of markedly importance in psittacines and that their evidence is much higher than it might be suspected on the basis of publications.

Animals↗

[Long-term culture of plasma cells from patients with myeloma and establishment of a permanent cell line].

UNLABELLED: Multiple myeloma plasma cells are actively dividing cells with the long surviving ability in the ex-vivo culture. In the effort for better understanding of the proliferative potential of malignant myeloma cells and establishment of permanent myeloma cell lines we performed long term cultures of human myeloma cells ex-vivo. During the last two years we cultured 41 bone marrow samples from 39 patients with multiple myeloma. Cells were cultured in the RPMI 1640 culture medium with 15% fetal calf serum at 37 degrees C in 5% CO2 and approximately one third of the culture medium was changed regularly twice a week. Most of the marrows cultures died by apoptosis within 30 days. Four bone marrow samples were cultured for more than 11 months, however, no culture can be qualified as an established cell line. In three cases permanent B-lymphoblastoid cell lines were established (UHKT-55, UHKT-56 a UHKT-57) but secondary immortalization by Epstein-Barr virus was suggested. CONCLUSIONS: Presented results suggest that myeloma plasma cells can survive and are able to proliferate in the ex-vivo culture for several months up to one year independently on the addition of any external growth factor without spontaneous apoptosis or necrosis. The probability of the establishment of a permanent cell line of plasma cell origin is, however, low. Presence of accessory bone marrow cells was the most important factor for the long-term survival of myeloma cells.

Adult↗

Antibody targeting studies in a transgenic murine model of spontaneous colorectal tumors.

Monoclonal antibodies (mAbs) have been used to treat malignancies in humans with varying degrees of success. Progress has been hindered by the lack of suitable animal models, which would ideally consist of immunocompetent animals that are tolerant to tumor-associated antigens. Suitable models would allow the study and optimization of anti-tumor immunotherapy. We describe a murine model for the study of immunotherapy in colorectal cancers. Carcinoembryonic antigen (CEA) is a cell-surface glycoprotein that is expressed on normal human intestinal epithelium and that is overexpressed in intestinal tumors. Mice that are transgenic for the human CEA gene (CEA.Tg) were crossed with multiple intestinal neoplasia (MIN) mice. MIN mice carry a germline APC mutation and are prone to the development of intestinal adenomas. The offspring from the MIN x CEA.Tg cross developed intestinal adenomas that were shown by immunohistochemistry to overexpress CEA. Pharmacokinetic studies by using (125)I-labeled anti-CEA mAb PR1A3 showed rapid localization of antibody to tissues expressing CEA, especially the gastrointestinal tract. Macroscopic and microscopic radioautographic analysis of the gastrointestinal tracts from MIN/CEA.Tg mice indicated that PR1A3 targeted and was retained in tumors at levels higher than in areas of normal gut. These results demonstrate the utility of the MIN/CEA.Tg mouse as a model for the study of anti-CEA immunotherapy and, furthermore, demonstrate the efficiency of tumor localization by PR1A3.

Animals↗

Alkaline-mediated differential interaction (AMDI): a simple automatable single-nucleotide polymorphism assay.

The key requirements for high-throughput single-nucleotide polymorphism (SNP) typing of DNA samples in large-scale disease case-control studies are automatability, simplicity, and robustness, coupled with minimal cost. In this paper we describe a fluorescence technique for the detection of SNPs that have been amplified by using the amplification refractory mutation system (ARMS)-PCR procedure. Its performance was evaluated using 32 sequence-specific primer mixes to assign the HLA-DRB alleles to 80 lymphoblastoid cell line DNAs chosen from our database for their diversity. All had been typed previously by alternative methods, either direct sequencing or gel electrophoresis. We believe the detection system that we call AMDI (alkaline-mediated differential interaction) satisfies the above criteria and is suitable for general high-throughput SNP typing.

Alkalies↗