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Biomedical subjects

R Scheuer

Publications and source records attributed to R Scheuer.

13 recordsLinked to original sources
PubMed1999

Comparison of ELISA and HPLC for the determination of histamine in cheese.

A competitive direct enzyme-linked immunosorbent assay (CD-ELISA) for histamine in cheese was compared with a reversed-phase liquid chromatography (RP-HPLC) method. Cheese was homogenized with phosphate-buffered saline (PBS), centrifuged, and filtered, and the supernatant was diluted with PBS for CD-ELISA. For RP-HPLC, biogenic amines (histamine, tyramine, putrescine, and cadaverine) were derivatized with 9-fluorenylmethylchloroformate, followed by reversed-phase chromatography and fluorescence detection. Detection limits and mean recoveries (10-1000 mg/kg) were 2 mg/kg and 93% for CD-ELISA and 1 mg/kg and 99% for RP-HPLC, respectively. Analysis of 50 commercial cheeses according to both methods showed good agreement for histamine (r = 0.979; concentration range = 2-1800 mg/kg). At a threshold level of 10 mg/kg, the ELISA gave no false-negative and three false-positive results. The results show that the ELISA is suitable for the determination of histamine in cheese.

Biogenic Amines↗
PubMed1994

Assessment of soluble adhesion molecules (sICAM-1, sVCAM-1, sELAM-1) and complement cleavage products (sC4d, sC5b-9) in urine. Clinical monitoring of renal allograft recipients.

Increasing evidence exists that inducible adhesion molecules are involved in cell-mediated allograft rejection. In addition, complement activation during rejection has been described. This study investigated, whether specific molecules derived from either pathway are excreted into urine during rejection and whether they can provide useful diagnostic tools for the monitoring of renal transplant recipients. Urinary concentrations of soluble adhesion molecules (sICAM-1, sVCAM-1, sE-selectin) and of complement cleavage products (sC4d and sC5b-9), were determined by standardized ELISA in 30 normal controls and 80 samples from 49 recipients of renal allografts. In contrast to the low amounts of adhesion molecules and complement components uniformly excreted by healthy persons (group 0), marked differences were observed among allograft recipients. To prove the clinical relevance of these differences in excretion, patient samples were assigned to 5 categories according to clinical and histopathological criteria: group I--acute steroid-resistant rejection (n = 10); group II--acute steroid-sensitive rejection (n = 10); group III--chronic rejection (n = 23); group IV--stable graft function (n = 27); and group V--miscellaneous disorders (n = 10), including infections, CsA overdoses, and glomerulonephritis. Urinary levels of sICAM-1, sVCAM-1, and sC4d were significantly higher in group I compared with all other groups (P < 0.01). The difference in sICAM-1 excretion between groups III and IV also reached statistical significance (P < 0.05). Urinary concentrations of sICAM-1, sVCAM-1, and sC4d were reflective of their histological distribution in corresponding graft biopsies. None of the patients excreted E-selectin in detectable amounts. Excretion of the terminal membrane attack complex C5b-9 was not significantly associated with any diagnosis. It is concluded that for clinical purposes the combined evaluation of sICAM-1, sVCAM-1, and sC4d is most useful and can provide valuable information with regard to the severity and the type of allograft rejection.

Cell Adhesion Molecules↗
PubMed1993

High incidence of carpal tunnel syndrome in diabetic patients after combined pancreas and kidney transplantation.

Fifty-eight patients with long-standing type 1 (insulin-dependent) diabetes were studied prospectively after combined pancreas and kidney transplantation for a mean observation period of 47.9 months (range 17-116 months). Thirty-three per cent of these patients (19/58) developed carpal tunnel syndrome after a mean interval of 1.7 years (range 3 months-5 years). This rate is about twice that in type 1 diabetic patients. The manifestation of carpal tunnel syndrome was not significantly associated with worsening of diabetic polyneuropathy or with deterioration of kidney or pancreas function. In all but one patient symptoms improved without surgical intervention. This study suggests that patients after combined pancreas and kidney transplantation have an increased risk of carpal tunnel syndrome for which the etiology and pathophysiology are unknown. In most patients no surgical intervention is necessary.

Adult↗
PubMed1993

Diabetic neuropathy 3 years after successful pancreas and kidney transplantation.

Twenty-seven patients with successful transplantation and a control group of 14 patients with early rejection of the pancreas graft but functioning kidney graft were examined in a prospective study for 3 yr. Before transplantation, all patients had long-standing type I diabetes with advanced secondary complications, including end-stage diabetic nephropathy. After transplantation in the patients of both groups, kidney function was almost normal. Mean HbA1 levels were normal in the group with pancreas graft survival. In the control group, HbA1 levels were, on average, 1.5% higher compared with the group with pancreas survival (P = 0.00005). After 3 yr, the patients with functioning pancreas graft showed fewer symptoms (mean difference 1.0 in a symptom score ranging from 0 to 16, P = 0.004) compared with the control group. No statistically significant difference between both groups concerning clinical signs of polyneuropathy could be observed. In the pancreas and kidney transplantation group, peroneal and median nerve conduction velocities increased 7.2 m/s (P < 0.01) and 3.5 m/s (P < 0.05), respectively, whereas no increase was registered in the control group. The change of median and sural sensory nerve conduction velocities, peroneal and median compound muscle action potentials, and sural and median sensory action potentials was insignificant. In conclusion, although the improvement of clinical symptoms and neurophysiological signs of polyneuropathy was modest in the pancreas and kidney transplantation group, our data suggest that successful pancreas transplantation is able not only to halt the progression of diabetic polyneuropathy but also to improve it to some extent even at a far advanced stage.

Action Potentials↗
PubMed1993

Research in the hospital setting on human subjects. Protecting the patient and the institution.

A hospital's institutional review board is charged with the responsibility of fully protecting the rights of research subjects. In doing so, the board establishes that research protocols are based on sound scientific principles, that benefits to research subjects outweigh the risks, and that the subject's consent is informed and not coerced. Although it has been argued that risk management has no role in the activities of such boards, the literature indicates that risk management and quality assurance principles apply to all areas of the institution, including the activities of the board. The institution must ensure that its researchers and board members are as fully protected as possible from civil and criminal liability and that the integrity of those conducting the research is established and maintained. The institution must also provide sufficient support for the board to conduct its reviews and educate the research community and board members on current and evolving laws and regulations governing human research. Risk prevention and quality assurance strategies should recognize the rights of the research subject as paramount while protecting the institution, its researchers, and the community served.

Contracts↗
PubMed1991

Effect of pancreatic and/or renal transplantation on diabetic autonomic neuropathy.

Thirty-nine Type 1 (insulin-dependent) diabetic patients were studied prospectively after simultaneous pancreas and kidney (n = 26) and kidney grafting alone (n = 13) by measuring heart rate variation during various maneuvers and answering a standardized questionnaire every 6 to 12 months post-transplant. While age, duration of diabetes, and serum creatinine (168.1 +/- 35.4 vs 132.7 +/- 17.7 mumol/l) were comparable, haemoglobin A1 levels were significantly lower (6.6 +/- 0.2 vs 8.5 +/- 0.3%; p less than 0.01) and the mean observation time longer (35 +/- 2 vs 25 +/- 3 months; p less than 0.05) in the pancreas recipients when compared with kidney transplanted patients. Heart rate variation during deep breathing, lying/standing and Valsalva manoeuver were very similar in both groups initially and did not improve during follow-up. However, there was a significant reduction in heart rate in the pancreas recipient group. Autonomic symptoms of the gastrointestinal and thermoregulatory system improved more in the pancreas grafted subjects, while hypoglycaemia unawareness deteriorated in the kidney recipients. This study suggests that long-term normoglycaemia by successful pancreatic grafting is able to halt the progression of autonomic dysfunction.

Adult↗
PubMed1989

Metabolic control and effect on secondary complications of diabetes mellitus by pancreatic transplantation.

After successful pancreatic transplantation blood glucose can be normalized without exogenous insulin, although oral and intravenous glucose tolerance remains impaired in 10-45% of the patients. There is no significant deterioration of glucose control with time in most patients. Since most recipients of pancreatic grafts have far advanced secondary diabetic lesions and the observation time after grafting is rather short, the effects of pancreatic transplantation on these complications are difficult to interpret. However, the development of diabetic nephropathy can be prevented, skin microcirculation improves significantly, while autonomic and peripheral neuropathy and diabetic retinopathy remain stable or improve slightly in most patients. But these ameliorations may be in part due to elimination of uraemia, since in almost all patients combined pancreas/kidney transplantations were performed. It is concluded that pancreas grafting probably has to be performed much earlier in the course of diabetes, although the improvement in the quality of life is striking even in the end-stage diabetics studied so far.

Blood Glucose↗
PubMed1978

The experiment in medical education at the City College of New York.

Described is a program leading to the B.S. and M.D. degrees in six or seven years which integrates the physical sciences with the basic medical sciences and emphasizes the humanities and social sciences as a necessary component of the physician's education. The selection process is designed to identify young men and women who will become primary care physicians in underserved urban communities. At the end of the fourth year it was shown that the graduates were comparable with second-year medical students as measured by national examinations. It is suggested that the changes made in the premedical curriculum merit general consideration inasmuch as the course work is more pertinent to the practive of medicine and offers a sound education for other health careers for those unable to continue their medical training.

Attitude↗