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Biomedical subjects

W Schroder

Publications and source records attributed to W Schroder.

12 recordsLinked to original sources
PubMed2002

Antiserum raised against the Epstein-Barr virus BARF0 protein reacts to HLA-DR beta chain.

The role that Epstein-Barr virus plays in nasopharyngeal carcinoma and Burkitt's lymphoma has been under intense study for many years. With only a limited set of viral genes being expressed in these tumours it has been difficult to understand how the virus could cause/aid in the generation of the tumours. In 1997 a paper was published by Fries et al. [Fries et al. (1997) Identification of a novel protein encoded by the BamH1 A region of the Epstein-Barr virus. J Virol 71: 2765-2771.] in which a rabbit serum was generated and used to identify protein products (RK-BARF0) encoded from the BamH1 A region of EBV. In this paper we have isolated these proteins from two-dimensional gels and identified them, using mass spectrometry, as components of HLA DR.

Amino Acid Sequence↗
PubMed2001

The Escherichia coli orthologue of the Salmonella ushB gene (ushB(c)) produces neither UDP-sugar hydrolase activity nor detectable protein, but has an identical sequence to that of Escherichia coli cdh.

Salmonella ushB, which encodes a membrane-bound UDP-sugar hydrolase, has an Escherichia coli orthologue (ushB(c)) which does not detectably produce this activity. In this report, we show that ushB(c) does not produce any detectable protein either, despite being transcribed normally. Remarkably, ushB(c) is shown to have 100% sequence identity with E. coli cdh, previously characterised as encoding an active CDP-diglyceride hydrolase, an apparent contradiction with implications regarding enzyme evolution. We suggest that a useful gene designation is cdh (ushB(c)) rather than either ushB(c) or cdh, alone.

Blotting, Southern↗
PubMed2001

Native aortic valve tissue systemic embolization complicating bacterial endocarditis.

Systemic embolic events are known complications of bacterial endocarditis. Embolization of prosthetic valves has previously been reported in the literature. We report a case of embolization of native aortic valve tissue to the popliteal artery as the presenting event in a patient with subacute bacterial endocarditis. To our knowledge, this rare complication has not been previously reported.

Adult↗
PubMed2000

Factor VIII gene polymorphisms in the Asian Indian population.

Little is known about the heterozygous frequency of factor VIII gene markers in the Asian Indian population. The objective of this study was to establish the heterozygous frequency of polymorphic markers within and flanking the factor VIII gene in Indians and identify those most informative for carrier screening and prenatal diagnosis. Factor VIII gene polymorphism analysis at intragenic and extragenic sites was carried out by the polymerase chain reaction (PCR) method and Southern blot procedure. Sixty-three Asian Indian haemophiliacs and their families were screened. A control group of 150 women from nonhaemophilic families were screened for two markers, HindIII and BclI. Among the intragenic markers studied, the HindIII restriction fragment length polymorphism (RFLP) showed the highest heterozygous frequency (0.52) followed by the intron 13 (0.47) and intron 22 (0. 44) short tandem repeats (STRs). Among extragenic markers, TaqI had the highest heterozygous frequency (0.75) followed by BglII (0.54). The intron 22 inversion mutation was observed in eight (40%) of 20 severe cases. In the population studied the most diagnostic polymorphisms were the intragenic markers, intron 22 (70%) STR followed by the intron 13 (52%) STR and HindIII (52%) RFLP, and the TaqI (50%) extragenic marker. Application of HindIII, BclI and the intron 22 dinucleotide repeat combined were diagnostic in 87.2% of haemophilia A families studied.

Alleles↗
PubMed1991

Interleaved magnetic resonance and ultrasound by electronic synchronization.

Increasing attention has been directed toward using magnetic resonance imaging (MRI) to assess blood flow velocity. Complete acceptance of this application requires validation of MRI-derived flow measurements against an accepted flow measurement technique such as Doppler ultrasound in an in vivo situation. To provide an accurate correlation in the presence of rapid changes in blood flow, the MR acquisition should be made nearly simultaneously with the ultrasonic measurements. Unfortunately, standard ultrasound equipment generates radio frequency signal which interferes with MRI. Near-simultaneous acquisition of MR data and ultrasonic blood flow data should be possible if the two measurements are properly synchronized. In the technique presented, ultrasound is made to peacefully coexist with MRI by gating the ultrasound so that it is disabled during the time of MR data acquisition. Phantom and animal experiments confirm the use of this procedure. Although we did not specifically test new fast-scan MR techniques, our technique is completely general and should work equally well with spin-echo as well as newer fast scanning MRI techniques.

Animals↗
PubMed1989

Utilization and outcome in the medical patient referred to surgery.

The objective of this study was to test the hypothesis that hospitalized patients referred to a general surgical service from a medical service for a surgical procedure would have higher hospital costs and longer lengths of stay per diagnosis-related group (DRG) than patients admitted directly to the general surgical service. Hospital costs by DRG, exclusive of physician's fees, were analyzed for all adult general surgical admissions treated at our hospital from January 1, 1985 to March 31, 1986 (3,028 patients) to yield a population of patients in those DRGs with patients referred to general surgery from medicine (1,495 patients). Patients within each DRG were then disaggregated by either direct admission to general surgery (1,412 patients) or referral to the general surgical service from the medical service (83 patients). Mean cost per patient was 146.5 percent higher for referral patients than for direct admission patients, as was the total length of stay. Mortality was higher for referral patients than for direct admission patients. Factors analyzed which contributed to this greater resource utilization and higher mortality were (1) a greater severity of illness, (2) higher diagnostic costs, and (3) delays in diagnosis or treatment. The DRG payment for referral patients also produced a substantial deficit for the hospital, whereas direct admission patients produced a profit of +1,105,596. This data suggests that direct admission to the surgical service of patients likely to need surgery might lower their hospital costs and improve the quality of their care.

Diagnosis-Related Groups↗
PubMed1988

XY sex reversal syndrome in the mare: clinical and behavioral studies, H-Y phenotype.

An inherited genetic disorder causes XY embryos of the horse to develop as mares. On the basis of our study of 38 such mares, we have identified four grades or classes of XY sex reversal according to this scheme: class I, nearly normal female, of which some are fertile; class II, female with gonadal dysgenesis, normal mullerian development; class III, intersex mare with gonadal dysgenesis, abnormal mullerian development, enlarged clitoris; class IV, virilized intersex characterized by high levels of testosterone. In general, class I and class II mares were typed H-Y antigen-negative whereas class III and class IV mares were typed H-Y antigen-positive.

Animals↗
PubMed1988

Activation of rabbit aortic elastase by nonaortic intraabdominal surgery.

The purpose of this study was to determine whether aortic elastase could be activated by distant operative trauma unrelated to direct aortic injury. One hundred rabbits were divided into five groups: group I - anesthesia only; group II - laparotomy only; group III - cecal resection; group IV - aortic mobilization; and group V - aortotomy with repair. Animals were sacrificed at one hour, three hours, six hours, one day, two days, and five days after surgery, and the aorta was analyzed for elastase activity. Operative trauma such as laparotomy, bowel resection, and mobilization of the aorta without direct aortic injury resulted in a significant increase in rabbit aortic elastase. The pattern of activation of rabbit aortic elastase within the laparotomy, aortic mobilization, and aortotomy groups was one of a slow rise to peak activation at 6-24 hours with a subsequent fall towards baseline at five days after surgery. This pattern differed in the cecal resection group in which activation occurred immediately with a slow fall towards baseline at five days. In none of the four surgical groups did the elastase activity return to baseline by five days after surgery. These data suggest that aortic elastase in rabbits can be activated by intraabdominal surgery unrelated to direct aortic injury.

Abdomen↗
PubMed1988

Mesenteric shunting during thoracoabdominal aortic clamping to prevent disseminated intravascular coagulation in dogs.

The current study was undertaken to determine if cold crystalloid perfusion of the mesenteric circulation or continuous arterial shunting into the superior mesenteric artery would prevent the subsequent development of disseminated intravascular coagulation in a dog model. Twenty-two dogs were divided into four groups: those with distal aortic occlusion; those with isolated washout of the mesenteric circulation via the superior mesenteric artery with cold crystalloid; those with continuous isolated arterial perfusion of the superior mesenteric artery via an open proximal aorta; and those with shunting of blood into the superior mesenteric artery from the proximal aorta with an Inahara-Pruitt shunt. Coagulation parameters were measured for 24 hours and compared to the results with 32 dogs in the following groups: sham operation; supraceliac aortic occlusion for 30 minutes, 60 minutes, 90 minutes; superior mesenteric occlusion for 90 minutes; and celiac axis occlusion for 90 minutes. Shunting or direct arterial perfusion of the superior mesenteric artery prevented disseminated intravascular coagulation from occurring. Infrarenal aortic occlusion resulted in no change in any of the coagulation factors, whereas crystalloid perfusion of the superior mesenteric artery resulted in death in all animals. These results indicate that the disseminated intravascular coagulation that occurs with supraceliac aortic occlusion or superior mesenteric occlusion of greater then one hour can be prevented by continuous arterial perfusion of the superior mesenteric artery during proximal aortic clamping.

Animals↗
PubMed1988

Age, resource consumption, and outcome for surgical patients at an academic medical center.

Many changes are under way in the payment for physician and hospital care of the surgical patient. Relatively little data have been analyzed on resource consumption for hospitalized surgical patients. The purpose of this study was to characterize hospital resource consumption and outcome by age for surgical patients. All surgical admissions at a large academic medical center from Jan. 1, 1985, through March 31, 1986, were analyzed by means of the diagnostic related group (DRG) format. Total costs (exclusive of physician fees) for the 7341 surgical patients studied were $58,206,815. Mean cost per patient, length of stay, percent of outliers, and mortality increased with age. DRG case-mix index and the number of procedures per patient peaked at age 69 and then decreased. Emergency admission was high for the young (i.e., aged 18 to 24 years) and for very elderly patients (i.e., aged over 75 years). Blood transfusions increased steadily as the age of the patient increased; use of surgical intensive care units increased until age 64 years, then plateaued. This study demonstrated a number of trends in surgical patient age and use of resources. Under prospective payment systems (i.e., DRG reimbursement) financial risk increased with the age of the patient. Length of hospital stay and mortality increased with age; however, DRG case-mix index and the number of procedures per patient peaked at age 69, which suggests that elderly surgical patients (i.e., those above 70 years of age) may be more severely ill on average than younger patients.

Academic Medical Centers↗