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Biomedical subjects

B Kraus

Publications and source records attributed to B Kraus.

At least 19 recordsLinked to original sources
PubMed2002

DNA array analysis in a Microsoft Windows environment.

Microsoft Windows-based computers have evolved to the point that they provide sufficient computational and visualization power for robust analysis of DNA array data. In fact, smaller laboratories might prefer to carry out some or all of their analyses and visualization in a Windows environment, rather than alternative platforms such as UNIX. We have developed a series of manually executed macros written in Visual Basic for Microsoft Excel spreadsheets, that allows for rapid and comprehensive gene expression data analysis. The first macro assigns gene names to spots on the DNA array and normalizes individual hybridizations by expressing the signal intensity for each gene as a percentage of the sum of all gene intensities. The second macro streamlines statistical consideration of the confidence in individual gene measurements for sets of experimental replicates by calculating probability values with the Student's t test. The third macro introduces a threshold value, calculates expression ratios between experimental conditions, and calculates the standard deviation of the mean of the log ratio values. Selected columns of data are copied by a fourth macro to create a processed data set suitable for entry into a Microsoft Access database. An Access database structure is described that allows simple queries across multiple experiments and export of data into third-party data visualization software packages. These analysis tools can be used in their present form by others working with commercial E. coli membrane arrays, or they may be adapted for use with other systems. The Excel spreadsheets with embedded Visual Basic macros and detailed instructions for their use are available at http://www.ou.edu/microarray.

Databases, Nucleic Acid↗
PubMed2001

Entanglement criteria for all bipartite Gaussian states.

We provide a necessary and sufficient condition for separability of Gaussian states of bipartite systems of arbitrarily many modes. The condition provides an operational criterion since it can be checked by simple computation. Moreover, it allows us to find a pure product-state decomposition of any given separable Gaussian state. We also show that all bipartite Gaussian states with nonpositive partial transpose are distillable.

Journal Article↗
PubMed2001

Ruptured papillary muscle after mitral valve replacement with preservation of chordae tendineae.

Many cardiac surgeons believe strongly that every effort should be made to preserve the continuity of the mitral anulus, chordae tendineae, and papillary muscles during mitral valve replacement in order to maximize ventricular function and maintain normal ventricular geometry. We treated a patient with spontaneous papillary muscle rupture after mitral valve replacement in whom efforts had been made to preserve continuity of the mitral mechanism.

Adult↗
PubMed2001

Significant reduction of air microbubbles with the dynamic bubble trap during cardiopulmonary bypass.

Air microbubbles mostly occur unnoticed during cardiopulmonary bypass and are predominantly responsible for serious postoperative psychoneurological dysfunction. A dynamic bubble trap (DBT), which removes air microbubbles from the arterial blood, was tested in a clinical study. The aim was to evaluate the efficiency of microbubble removal under clinical conditions. As blood passes through the DBT, which is placed in the arterial line between the arterial filter and arterial cannula, it is converted into a rotating stream. The bubbles are directed to the centre of the blood flow and are collected in the distal end of the DBT, from where they are returned to the cardiotomy reservoir. Doppler ultrasonography was used to detect the microbubbles before and after the DBT, and also the number of high-intensity transient signals (HITS) in the right and left middle cerebral artery during extracorporeal circulation. A significant reduction of microbubbles in the arterial line (3,990 before DBT, 537 after, p < 0.001) and HITS in the brain (51 in the DBT group, 77 in the placebo group, p = 0.04) was measured.

Adult↗
PubMed2000

[Symptomatic true aneurysm of a venous bypass with compression of the right atrium].

A symptomatic true aneurysm of a saphenous vein graft to the right coronary artery in a female patient twelve years after bypass surgery is presented. Beating heart surgery included resection of the aneurysmatic saphenous vein graft, reconstruction of the right atrium and coronary artery bypass grafting to the right coronary artery. The symptoms of aneurysms of vein grafts, the diagnostic procedures and the surgical treatment are discussed.

Aged↗
PubMed2000

Progressive muscle pain, weight gain, fatique and unusual body shape change.

Multiple symmetrical lipomatosis (MSL) is a rare syndrome characterized by symmetric unencapsulated lipomas around the axial region and frequently associated with neurological involvement, particularly myopathy and neuropathy (Klopstock et al., 1994). Here we present a typical image of a patient with MSL, explaining this disease for neurologists who might care for these patients in an average day at the neuromuscular consultation unit.

Fatigue↗
PubMed2000

The effect of leukocyte-depleted blood cardioplegia in patients with severe left ventricular dysfunction: a randomized, double-blind study.

BACKGROUND: The propensity for leukocytes to cause reperfusion injury in patients undergoing heart surgery is widely accepted. Reperfusion injury may result in myocardial damage and unfavorable operative outcome, especially in patients with severely reduced ejection fractions. This study was performed to evaluate the impact of leukocyte filtration on the postoperative course of patients undergoing coronary bypass surgery. METHODS: Thirty-two patients with coronary artery disease and left ventricular ejection fraction less than 35% were included in this double-blind, randomized study. Two serial leukocyte removal filters (Pall BC1B filter [Pall Biomedical, Portsmouth, England], group F, 15 patients) or two dummy filters (group C, 17 patients) were connected to the blood cardioplegia line. Leukocyte count, hemodynamic measurement, and transesophageal echocardiography were performed before and after cardiopulmonary bypass. Cardiac-specific enzymes were analyzed from arterial blood during the first 72 hours and from coronary sinus blood 30 and 60 minutes after aortic unclamping. RESULTS: Patient characteristics were similar in the two groups (ejection fraction 20.9% +/- 4.3% in group C and 21.1% +/- 4.8% in group F; P =.773). No early death or perioperative myocardial infarction occurred. Leukocyte count, hemodynamic parameters, cardiac troponin T, cardiac troponin I, and creatine kinase MB mass levels in arterial blood were similar in the two groups. Group F showed lower release of cardiac troponin T from the coronary sinus 30 minutes after unclamping of the aorta (group F, 0.263 +/- 0.12 ng/mL; group C, 0.6 +/- 0.32 ng/mL; P =.005). Lower doses of dopamine were necessary after cardiopulmonary bypass (group F, 0.36 +/- 0.11 mg x kg(-1) x min(-1); group C, 0.49 +/- 0.14 mg x kg(-1) x min(-1); P =.003). A moderate increase in ejection fraction was observed at 30 minutes in both groups (group F, 30.3% +/- 6.2%; group C, 28.0% +/- 6.3%; P =.239) and a significant increase at 60 minutes in group F (group F, 32.5% +/- 6.0%; group C, 27.4% +/- 7.5%; P =.012). CONCLUSIONS: These results indicate that serial leukocyte filters connected to the blood cardioplegia line decrease myocardial cell injury and may therefore help to improve outcome of patients with severely depressed ejection fractions undergoing coronary artery bypass grafting.

Aged↗
PubMed1997

Quantification of MyoD, myogenin, MRF4 and Id-1 by reverse-transcriptase polymerase chain reaction in rat muscles--effects of hypothyroidism and chronic low-frequency stimulation.

A highly sensitive method of reverse-transcriptase polymerase chain reaction (RT-PCR) was established to quantify transcript levels of the myogenic regulatory factors MyoD, myogenin and MRF4 (muscle regulatory factor 4) and for Id-1 (inhibitor of differentiation), a putative negative regulator of myogenesis. The method was sensitive enough to detect mRNA amounts as low as 20 molecules. Measurements in 10 different skeletal muscles of the rat revealed that the amounts of the four factors differ by almost three orders of magnitude. Id-1 is expressed at lowest levels (approximately 4x10(5) molecules/microg RNA) and MRF4 at highest levels (approximately 9x10(7) molecules/microg RNA). In general, myogenin and MyoD mRNAs were inversely distributed in slow and fast muscles. A correlation seemed to exist between the levels of MyoD and myosin heavy chain (MHC) IIb, the fastest MHC isoform. However, as revealed by changes in the expression levels of these two regulatory factors under conditions of hypothyroidism and chronic low-frequency stimulation (CLFS), MyoD and myogenin did not seem to be strictly correlated with fast and slow myosins, respectively. Hypothyroidism led to pronounced depressions of MyoD, but only to small increases in myogenin mRNA in fast muscles. These changes were only slightly increased by CLFS. However, as previously shown, CLFS in combination with hypothyroidism induces in rat muscle pronounced fast to slow transitions in myosin expression [Kirschbaum, B. J., Kucher. H.-B., Termin, A., Kelly, A. M. & Pette, D. (1990) J. Biol. Chem. 265, 13974-13980]. These findings suggest that MyoD and myogenin may not be causally related to the development and maintenance of fiber-type diversities.

Animals↗
PubMed1996

Myocardial extraction of bupivacaine in anaesthetized sheep and by hearts of sheep and rats in vitro.

We observed the in vivo kinetics of bupivacaine in the cardiopulmonary system, particularly in the pulmonary artery, the upper part of the descending aorta and the coronary sinus of anaesthetized sheep, each of which received a high dose infusion into the central vein. In some experiments dilution curves were monitored for the non-extracted dye, indocyanine green. Concentrations of bupivacaine were approximately 20% lower in the aorta than in the pulmonary artery. This gradient of bupivacaine was present across the lung for 5-10 min. Concentrations of bupivacaine in the coronary venous plasma were also markedly lower than at the arterial site. Initially more than 50% of the amount of bupivacaine at the arterial site was removed by the heart. Later, the myocardial extraction ratio decreased and plateaued at a value of 0.30-0.40. At this time, concentrations of bupivacaine in the pulmonary artery were approximately 12 micrograms ml-1. Therefore, approximately 0.3-0.6 mg of bupivacaine were extracted per minute by the sheep heart in vivo. On the other hand, isolated perfused rat hearts did not substantially remove bupivacaine (2 micrograms ml-1) from the medium. Approximately one-third of 14C-bupivacaine was retained in slices of rat and sheep myocardial tissue. However, there was no evidence that metabolism played a substantial role in the cardiac kinetics of bupivacaine.

Anesthetics, Local↗
PubMed1996

[Distribution of lymph nodes and lymph node metastases in esophageal carcinoma].

BACKGROUND: Lymph node metastases are an independent prognostic factor in esophageal cancer. Accurate pathologic work up depends on detailed knowledges of number and anatomic distribution of lymph nodes and metastases. Factors that may determinate metastatic spread are also important. METHODS: One hundred and fifty-six patients with esophageal cancer were included in this study. Number and localization of nodes and metastases were documented and correlated with localization, infiltration deepness and grade of malignancy of the tumor. The effectivity of the search for nodes and metastases was also studied. RESULTS: We found 3869 lymph nodes containing 338 metastases in the 156 specimens (median 25 and 2). 53.2% of the cases exhibited metastases and 15.4% contained only solitary metastasis. The minimal number of lymph nodes for excluding of metastasis was about six nodes. Most of the nodes were found at lower esophagus and on the oral stomach resection. Tumors of the middle and upper thoracal esophagus spread also frequently to the nodes along the lesser curvature of the stomach. Between infiltration deepness and grade of malignancy of the tumors a positive association was found. CONCLUSIONS: Lymph node metastases are a frequent pathological feature in esophageal cancer which depends on infiltration deepness and grade of malignancy of the tumor. This allows the estimation of metastatic spread. For staging a minimum of six nodes must be found in the specimen. In this context the frequent metastases along the lesser curvature of the stomach must be considered.

Adenocarcinoma↗
PubMed1995

Increased incidence of renal cell tumors in a cohort of cardboard workers exposed to trichloroethene.

A retrospective cohort study was carried out in a cardboard factory in Germany to investigate the association between exposure to trichloroethene (TRI) and renal cell cancer. The study group consisted of 169 men who had been exposed to TRI for at least 1 year between 1956 and 1975. The average observation period was 34 years. By the closing day of the study (December 31, 1992) 50 members of the cohort had died, 16 from malignant neoplasms. In 2 out of these 16 cases, kidney cancer was the cause of death, which leads to a standard mortality ratio of 3.28 compared with the local population. Five workers had been diagnosed with kidney cancer: four with renal cell cancers and one with a urothelial cancer of the renal pelvis. The standardized incidence ratio compared with the data of the Danish cancer registry was 7.97 (95% CI: 2.59-18.59). After the end of the observation period, two additional kidney tumors (one renal cell and one urothelial cancer) were diagnosed in the study group. The control group consisted of 190 unexposed workers in the same plant. By the closing day of the study 52 members of this cohort had died, 16 from malignant neoplasms, but none from kidney cancer. No case of kidney cancer was diagnosed in the control group. The direct comparison of the incidence on renal cell cancer shows a statistically significant increased risk in the cohort of exposed workers. Hence, in all types of analysis the incidence of kidney cancer is statistically elevated among workers exposed to TRI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

An imaging filter for biological applications.

A recently developed post-column imaging filter optimized for biological electron microscopy is described. The filter uses a single magnetic prism, four strong quadrupole lenses and five sextupole lenses to form images and spectra free of all important aberrations and distortions of first and second order. The performance of the filter is illustrated with practical applications. It is shown that the filter offers several important advantages over currently existing in-column filters, particularly in the areas of imaging at low magnifications, attainable collection efficiency, energy resolution, and general spectroscopic operation.

Animals↗
PubMed1994

A novel cyclin gene (CCNF) in the region of the polycystic kidney disease gene (PKD1).

The major locus for autosomal dominant polycystic kidney disease (PKD1) is located in a gene-rich region on chromosome 16p13.3. Recently the identification of the gene responsible for PKD1 has been described. While searching for candidate genes in this region, we isolated a new member of the cyclin family. We have characterized the transcript by sequencing, determination of the exon intron boundaries, and Northern blot analysis. Cyclin F is related to A- and B-type cyclins by sequence, but its function is unknown.

Amino Acid Sequence↗