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Biomedical subjects

C M Niederau

Publications and source records attributed to C M Niederau.

11 recordsLinked to original sources

Screening for hemochromatosis and iron deficiency in employees and primary care patients in Western Germany.

BACKGROUND: Many physicians still believe that iron overload (hemochromatosis) is an uncommon disorder. OBJECTIVE: To estimate the frequency of iron overload and iron deficiency in a group of employees and a group of outpatients. DESIGN: Prospective screening study. SETTING: Western Germany. PARTICIPANTS: 3012 asymptomatic employees and 3027 outpatients of nine practitioners. MEASUREMENTS: Serum ferritin levels and transferrin saturation were measured. Participants with repeatedly abnormal results had thorough clinical evaluations to identify the cause of iron deficiency or overload. RESULTS: Gross iron overload (elevated transferrin saturation and ferritin levels) was proven by liver biopsy and phlebotomy treatment in 28 participants (0.4% of female outpatients, 0.7% of male outpatients, 0.2% of female employees, and 0.4% of male employees) and in six siblings of these participants. Of the 34 participants with iron overload, 30 were precirrhotic. Because 60% of an unselected group of employees with elevated transferrin saturation but normal ferritin levels were assumed to have early hemochromatosis, the prevalence of hemochromatosis was estimated to be 1.8% among patients (1.9% in women and 1.6% in men) and 1.0% among employees (1.1% in women and 1.0% in men). Iron deficiency was found in 6.8% of female patients, 2.4% of male patients, 6.0% of female employees, and 0.5% of male employees. CONCLUSIONS: Iron deficiency was more common in women, and iron overload was more common in men. Among male employees, iron overload was almost as common as iron deficiency.

Adult↗

Elecsys CEA, PSA and AFP. Clinical results of a multicentre evaluation.

Three tumormarker assays, Elecsys CEA, PSA and AFP, have been evaluated in an international multicentre study to characterize their clinical performance and to verify the comparability with the corresponding tests of the Enzymun-Test product line and other methods. For each of the markers results were obtained from four laboratories. On the basis of 314 and 199 specimens respectively, (preliminary) reference ranges could be established for CEA and PSA. For the prostate marker, the age dependence of the antigen level could be clearly confirmed. Mean concentrations range between 0.51 ng/ml (< 40 years) and 3.57 ng/ml (> 70 years). Referring to CEA, 95th percentiles of 4.31 ng/ml and 2.69 ng/ml were elaborated for smokers and nonsmokers. In general, good to excellent correlations (r > 0.98) were found between the Elecsys and Enzymun-Tests. Regarding the systematic comparability of both systems, most of the slopes derived from the individual method comparison studies are within the +/- 10% range of the respective standardization results. The specific distribution pattern of the individual tumormarker values elaborated with sample material of known clinical background, reflects the well established categorization of different benign and malignant diseases according to their characteristic marker levels. Of utmost importance, however, is the excellent comparability of the Elecsys assays with the corresponding Enzymun-Tests and the FDA approved AIA 1200 tests from TOSOH in follow-up studies. Almost superimposable concentration curves guarantee that identical diagnostic information is derived from all three methods. Especially for PSA, a series of measurements on sera of prostatectomized patients proved the usability and clinical value of the test also for this particular indication. For either one of the Elecsys tests, the feasibility of using plasma as sample material was verified.

Adult↗

Long-term follow-up of HBeAg-positive patients treated with interferon alfa for chronic hepatitis B.

BACKGROUND: In patients with chronic hepatitis B, treatment with interferon alfa and the consequent loss of hepatitis B e antigen (HBeAg) from the blood leads to a reduction in inflammatory activity, but the clinical benefits of this treatment have not been established. We evaluated whether HBeAg seroconversion induced by interferon alfa improves clinical outcome. METHODS: We studied prospectively a cohort of 103 patients treated with interferon alfa for chronic hepatitis B; the mean (+/- SD) follow-up was 50.0 +/- 19.8 months. Fifty-three untreated patients served as controls. RESULTS: After treatment with interferon alfa, 53 of 103 patients no longer had detectable HBeAg or hepatitis B virus DNA, although only 10 patients became seronegative for hepatitis B surface antigen (HBsAg) (Kaplan-Meier estimates of cumulative clearance rates at five years, 56.0 percent for HBeAg and 11.6 percent for HBsAg). Of the 53 untreated patients, only 7 spontaneously eliminated HBeAg (28.1 percent at five years), and all remained positive for HBsAg (p < 0.001 for the Comparison with the treated patients, by the proportional-hazards model). During follow-up, 6 of the 103 treated patients died of liver failure, and 2 needed liver transplantation, all 8 were persistently positive for HBeAg. In another eight treated patients, complications of cirrhosis developed; all but one of these patients remained positive for HBeAg. Overall survival and survival without clinical complications were significantly longer in patients who were seronegative for HBeAg after therapy with interferon alfa than in those who remained seropositive (P = 0.004 and P = 0.018, respectively). In a regression analysis, clearance of HBeAg was the strongest predictor of survival. Of the 53 untreated patients, 13 had severe complications (including 4 deaths and 1 need for liver transplantation); all 13 continued to be HBeAg-positive. CONCLUSIONS: In patients with chronic hepatitis B infection, the clearance of HBeAg after treatment with interferon alfa is associated with improved clinical outcomes.

Antiviral Agents↗

[Extra-cardiac risk factors in heart surgery evaluated by the gastroenterologist].

The present review analyzes the main gastroenterologic and hepatologic risk factors that influence the risk of cardiosurgical operations, as well as the prognosis. Gastroenterological or hepatic diseases are only rarely a contraindication for open-heart surgery, but sometimes require further preoperative diagnostic investigations and treatment. Although gastroenterological or hepatic complications of open-heart surgery are present in less than 1% of all cases, up to 30-40% are lethal. The severe complications often require other surgical interventions, especially in case of perforation of ulcer, gastrointestinal bleeding or intestinal ischemia. The postoperative jaundice of unknown origin is a very difficult clinical problem. Its pathogenesis is still incompletely understood.

Gastrointestinal Diseases↗

[Hyperglycemia as a risk factor in pregnancy (author's transl)].

Glycosylated hemoglobins were used for the retrospective assessment of glucose metabolism, for therapy control, and as predictor of the weight of the newborn. Glycosylated hemoglobins were determined with the microcolumn method in 50 pregnant diabetics, in 11 overweight pregnant women, in 11 pregnant women under tocolytic treatment, and in 28 metabolically healthy women. Whereas the levels of glycosylated hemoglobins were found to be reduced in metabolically healthy women, the corresponding levels were increased in tocolytically treated, adipose, and diabetic pregnant women. The HbAI values correlated with the mean values of the daily blood glucose profiles (r = 0.79 - 0.94) and decreased during improvement of the metabolic state. A statistic correlation could not be established between the maternal HbAI and the weight of the newborn as the pregnancy period is shortened by dearrangement of the carbohydrate metabolism.

Blood Glucose↗

[Comparison of analytical methods for the estimation of glycosylated haemoglobins (author's transl)].

The glycosylated haemoglobins of 26 different blood samples were analysed by six different methods; the regression lines and the correlation coefficients were calculated from the analytical data. The best separation and estimation of the fast haemoglobin fractions were achieved by high performance liquid chromatography (HPLC). Therefore HPLC is regarded as the reference method for the analysis of fast haemoglobin fractions. Microcolumn chromatography or the thiobarbituric acid method are recommended for routine analysis in clinical laboratories. Since the labile aldimine (Schiff's base) can be calculated from the analytical data or destroyed by appropriate methods, this glycosylated haemoglobin fraction does not interfere with the results.

Chromatography, Gel↗

Enzymun-Test TG: results from external evaluation.

A new non isotopic assay for determination of thyroglobulin has been developed by Boehringer Mannheim. This assay uses a new international reference material for calibration, that is thought to replace the current manufacturer specific standardization. Several aspects of the technical performance of this assay have been evaluated in a multicenter evaluation, including precision profile, lower detection limit, recovery testing and method comparison. Additionally reference ranges were established. The presented assay fulfils clinical and analytical needs and offers for the first time a calibration according to a new international certified reference material.

Calibration↗