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M Armbruster

Publications and source records attributed to M Armbruster.

10 recordsLinked to original sources
PubMed2001

Numerical modelling of dynamic sludge blanket behaviour in secondary clarifiers.

New developments in numerical modelling of turbulent and density-affected flow in secondary clarifiers are reported. The sludge blanket is included in the computation domain which allows us to account for sedimentation and resuspension of sludge as well as the growth and diminution of the sludge blanket and at the same time respecting mass conservation. It is shown how strongly the prediction of the sludge-blanket height depends on the approaches to describe the settling behaviour of the sludge and the rheological properties within the sludge blanket. Further, an example of dynamic simulation is presented and discussed. This demonstrates how the sludge blanket behaves during load variation and that instabilities may occur at the interface of sludge blanket and supernatant, potentially resulting in sludge wash-off during transient phases, which is not only during load increase but also during load decrease.

Chemical Precipitation↗
PubMed1997

Psychiatric disorders in adult patients with early-treated phenylketonuria.

OBJECTIVE: To determine psychiatric disorders in patients with phenylketonuria (PKU) and to test whether biochemical control, intellectual functioning, white matter abnormalities visible on magnetic resonance imaging (MRI), and/or style of parenting influence psychopathology. DESIGN AND SUBJECTS: This cross-sectional study consisted of 35 PKU patients 17 to 33 years of age (mean: 22.2). From a total of 67 patients, 3 patients were selected because of other causes of possible brain damage. Then 35 patients were randomly drawn with comparison with a control sample (n = 181) from an epidemiologic study. METHODS: We used a standardized, highly structured, face-to-face interview; intelligence quotient (IQ) test; cranial MRI (n = 26); and monitoring of plasma phenylalanine. RESULTS: The overall rate of psychiatric disorders was 25.7% in PKU patients and 16.1% in controls. This difference was not statistically significant. The pattern of psychiatric disturbances was different for PKU patients and controls (Fisher's exact test): in PKU patients, externalizing disorders were reduced (PKU: not present, controls: 7.8%), whereas internalizing disorders (PKU: 25.7%, controls: 8.3%) were increased. International Classification of Diseases, version 10, diagnoses were predominantly those of the depressive category and more frequent in women (8 of 18 females and 1 of 17 males). A correlation between IQ and both biochemical control up to 12 years of age and school education of parents was confirmed. No correlation was found between the severity or pattern of psychiatric disturbances and school education of parents, biochemical control, IQ, or the extension of MRI-visible, white matter abnormalities. It was found that a restrictive controlling style of parenting is a risk factor for the development of psychiatric symptoms. CONCLUSIONS: Our results support a psychological perspective for the development of psychiatric symptoms in PKU. Thus, optimizing medical treatment necessary to prevent brain damage should be accompanied by psychiatric monitoring and psychological support for the families.

Adolescent↗
PubMed1994

Intestinal B cell defects in common variable immunodeficiency.

The humoral immune system of the small intestine of 17 patients with common variable immunodeficiency (CVID) was studied by immunohistology using antibodies specific for IgA1,2, IgM, IgG1-4, the J chain and the secretory component (SC). IgA1,2+, IgG2+ and IgM+ lamina propria B cells were totally lacking in 65% (11/17), 41% (7/17) and 18% (3/17) of CVID patients, respectively. One patient exhibited an isolated IgA1 subclass deficiency. The proportion of plasma cells in conventionally stained histological sections of the same intestinal biopsies showed a close correlation with the numbers of IgA+ and IgM+ cells. Considerable numbers of J chain-synthesizing cells were present in all patients with CVID, indicating the presence of early B cells unable to differentiate into immunoglobulin-producing plasma cells. Most of the patients with intestinal IgA and/or IgM defects strongly expressed the SC in their enterocytes, suggesting an immunoglobulin-independent regulation of the SC. Clinically, only CVID patients with intestinal IgA defects developed intestinal infections with Giardia lamblia, Campylobacter jejuni or Candida albicans. The outcome of in vitro immunoglobulin synthesis assays with peripheral blood lymphocytes did not predict the presence or absence of the respective isotype-producing B cells in the intestinal lamina propria. Thus, immunohistological examinations of intestinal biopsies are required to determine the extent of mucosal immunodeficiency in CVID patients.

Adolescent↗
PubMed1994

Psychopathology of patients treated early for phenylketonuria: results of the German collaborative study of phenylketonuria.

At the age of 13 years, 60 adolescents, suffering from phenylalaninemia due to hydroxylase deficiency, and their mothers were simultaneously investigated with a standardized psychiatric interview in order to determine the adolescents' psychiatric status. Forty symptoms related to emotional disorders, antisocial and conduct disorders, hyperkinetic syndromes, and specific symptoms like psychophysiological pains, enuresis, encopresis, tics, stereotypies, and eating disorders were examined. Severity level was rated as undisturbed, mild, moderate, and severe disturbance. Comparison with a representative sample of 191 age mates revealed a double rate of moderate disturbances for the PKU sample. There was no association between severity level and sex as well as mean phenylalanine level during the first 13 years of the patients' lives. No PKU specific diagnosis could be determined. WISC-R-IQ below 90 was associated with a threefold risk of more severe disturbance and patients with more than three adverse familial circumstances had a 50% chance of getting a psychiatric diagnosis. It is concluded that the observed disturbances result from stress associated more with the chronic condition than with the increased phenylalanine level.

Adolescent↗
PubMed1991

[Immunologic defects in the lymphatic system of the intestinal mucosa in common variable immunodeficiency (CVID) syndrome].

The humoral immune system of the intestinal mucosa of patients with common variable immuno deficiency (CVID) syndrome was studied immunohistologically using antibodies against immunoglobulin (Ig) A1-2, M and G1-4, against the J chain and the secretory component. In 9/13 CVID-patients IgA-positive cells were totally absent whereas a total IgM-defect was found only in 3/14 patients. Considerable numbers of J chain-positive cells were present in all CVID-patients irrespective of the extent of the Ig-defect indicating the presence of early B-cells unable to differentiate and to produce Ig. There was a strong expression of the secretory component in the cytoplasm and at the surface of enterocytes even in those CVID-patients who were totally defective in IgA- and IgM-positive cells.

Humans↗
PubMedDate not supplied

A diabetes control program in a public health care setting.

The Houston Diabetes Control Program is part of an effort by the State of Texas and approximately 30 other programs throughout the United States to ensure that persons with diabetes-related complications receive ongoing state-of-the-art preventive care and treatment. For the past 5 years, this program has served an urban, high-risk patient population with special cultural, ethnic, and economic challenges. The intervention has included the development and implementation of protocols for the prevention and care of diabetes-related complications of the eyes, lower extremities, and cardiovascular system, as well as general management of diabetes and patient and professional education. The program is ongoing in nine community health centers located in low-income neighborhoods of a large metropolitan area. The results thus far indicate an increase in sensitive eye examinations from 8 percent to 26 percent of the patient population, a reduction in incidence of legal blindness from 9.5 to 2.7 per 1,000 during a 4-year period, an increase in foot examinations from 18 percent to 44 percent of the patient population, and 77 percent of hypertensive patients in good control of blood pressure at less than 160 over 95 mmHg (millimeters of mercury). On the average, there have not been significant long-term improvements in weight reduction or blood glucose control. The major challenges for this program are (a) improvement in control of glycemia, hypertension, and cholesterol; (b) more effective diet and physical activity interventions; and (c) more effective education approaches that help patients to understand metabolic and cardiovascular functions. These challenges will require collaboration of health care professionals in constructive and imaginative ways through their unselfish commitment toward common goals.

Aged↗