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Biomedical subjects

M Kamm

Publications and source records attributed to M Kamm.

15 recordsLinked to original sources
PubMed2006

Chemical and biochemical generation of carbohydrates from lignocellulose-feedstock (Lupinus nootkatensis)--quantification of glucose.

Different chemical and enzymatic methods were applied for the hydrolysis of main stems from Lupinus nootkatensis (harvest November 2002). The whole process (all steps) is based on the lignocellulose-feedstock biorefinery regime. The acid hydrolysis of L. was performed with concentrated hydrochloric acid; advantages in this process are exothermic hydrolysis and the possibility of acid recovery. Enzymatic hydrolysis achieved high yields of fermentable carbohydrates (regarding to input cellulose) with high selectivity. However, this way requires the generation of cellulose from L. by chemical pulping. Monosaccharide derivatives thus obtained were identified by their GC retention times and the corresponding MS fragmentation. Hexamethyldisilazane was used as derivatization reagent to prepare the trimethylsilyl derivatives of the carbohydrates and of the degradations products of cellulose from the different fractions. The glucose content was quantified by GC peak integration with respect to an internal standard.

Biomass↗
PubMed2004

Polycarnitine--a new biomaterial.

The natural product L-carnitine is--due to its biotechnological accessibility and specific properties--on the way to becoming an attractive biobased bulk product. L-carnitine is a natural betaine with vitamin properties. Carnitine is an essential part of the fatty acid metabolism of human beings and animals. Carnitine was first isolated in 1905 from meat extract and important recent developments include the biosyntheses of L-carnitine from L-lysine or gamma-butyrobetaine. Our synthesis routes are designed to maintain the primary structure and specific properties of carnitine, such as hydrophilicity and "stiffening" effects for polymeric structures and applications. L-carnitine is converted via lactonization or olefinization into polymerizable basic molecules. The properties and the applications of carnitine polymers are described.

Biotechnology↗
PubMed2004

Principles of biorefineries.

Sustainable economic growth requires safe, sustainable resources for industrial production. For the future re-arrangement of a substantial economy to biological raw materials, completely new approaches in research and development, production and economy are necessary. Biorefineries combine the necessary technologies between biological raw materials and industrial intermediates and final products. The principal goal in the development of biorefineries is defined by the following: (biomass) feedstock-mix + process-mix --> product-mix. Here, particularly the combination between biotechnological and chemical conversion of substances will play an important role. Currently the "whole-crop biorefinery", "green biorefinery" and "lignocellulose-feedstock biorefinery" systems are favored in research and development.

Bioelectric Energy Sources↗
PubMed2001

Survey of children supported by long-term mechanical ventilation in Switzerland.

OBJECTIVE: The aim of the present study was to identify the number of children, from birth to 16 years of age, on long-term mechanical ventilation in Switzerland, and to establish their current location, underlying diagnoses and ventilatory needs. METHODS: Postal questionnaires were sent to all chest physicians (pulmonologists), intensive care specialists, neurologists, national health care organisations, rehabilitation services and ventilator suppliers known or thought to be involved in paediatric long-term ventilation in Switzerland. RESULTS: Detailed information was obtained on 32 children from 7 centers. Underlying disorders included congenital central hypoventilation syndrome (CCHS, 41%), neuromuscular disorders (41%), spinal cord injury (6%), craniofacial anomalies (6%) and others (6%). 10 children received positive pressure ventilation by tracheostomy and 19 children by nasal mask. Two children were ventilated by phrenic nerve pacing and one child with the help of a pneumatic belt. Children with CCHS were almost equally divided into nasal mask and tracheostomy users. Ventilation for 16-24 hours a day was necessary in 5 children, exclusively during sleep in 24 children and only episodically in 3 children. All but 2 children were cared for at home. The majority of families received home care support. The most common reasons for readmission into hospital were regular follow-up examinations and respiratory tract infections. The children were mainly admitted to paediatric intensive care units. CONCLUSIONS: There are few ventilator-supported children in Switzerland and most of them are cared for at home. Nevertheless, there is a need to establish a system for continuing data collection in this particular patient population to assess outcome and quality of home care support and to follow incidence trends.

Adolescent↗
PubMed1998

Quality of Life in Reflux and Dyspepsia patients. Psychometric documentation of a new disease-specific questionnaire (QOLRAD).

OBJECTIVE: To develop a disease-specific QOL instrument (QOLRAD) addressing patient concerns in gastroesophageal reflux disease (GERD) and dyspepsia. Patients. 759 male (45%) and female (55%) patients with a mean age of 48.4 years (sd 15.2) were used in the psychometric evaluation. MAIN OUTCOME MEASURES: A pilot version of QOLRAD, the Gastrointestinal Symptoms Rating Scale (GSRS) and the SF-36 were completed prior to endoscopy. Items with a high ceiling effect, items measuring a different construct, i.e. with a low squared multiple correlation (R < 0.5) with the other items, items that showed redundancy by a high correlation (>0.80) with another item were removed. A confirmatory factor analysis was also performed. RESULTS: The final questionnaire included 25 items depicting problems with emotions, vitality, sleep, eating/drinking, and physical/social functioning. The internal consistency reliability was high (alpha value overall 0.97, dimensions 0.89-94). Construct validity, i.e. the associations between similar constructs in the QOLRAD, the SF-36 and the GSRS scores was confirmed. Pain and symptom severity were markers of impaired QOL. The impact on health-related QOL was similar across the functional gastrointestinal disorders with the exception of patients with a normal endoscopy, who did slightly worse. CONCLUSION: The QOLRAD is a short and user-friendly instrument with excellent psychometric properties. Its responsiveness to change in (AVMC1) clinical trials is currently being explored.

Adolescent↗
PubMed1997

[The first manifestations of Schönlein-Henoch purpura in a 74-year-old female patient with hyperthyroidism].

HISTORY AND CLINICAL FINDINGS: A 74-year-old woman had for 3 weeks suffered from watery diarrhoea and diffuse abdominal pain. She felt restless, had a subfebrile temperature (37.8 degrees C), tachycardia and a blood pressure of 190/90 mmHg. Shortly after admission petechiae were found over the lower legs and she complained of joint pains. INVESTIGATIONS: Laboratory tests established hyperthyroidism. Skin biopsy showed leukocytoclastic vasculitis. Tests for antinuclear antibodies, antistreptolysin titre, rheumatoid factors, cryoglobulins and TSH-receptor antibodies were negative, immunoglobulin A (IgA) was raised. TREATMENT AND COURSE: As a drug-induced vasculitis was suspected treatment was started with methylprednisolone, 100 mg daily. Proteinuria (5.6 g daily) indicated renal biopsy, which revealed focal glomerulonephritis with deposits of IgA, fibrin/fibrinogen and complement factor 3. Gastroscopic biopsy, performed after an episode of gastrointestinal bleeding, demonstrated necrotizing vasculitis, confirming the diagnosis of Schönlein-Henoch-purpura (SHP). As the patient's condition rapidly worsened, cyclophosphamide was started additionally (2 mg/kg). She died on the 17th hospital day from acute cardiac failure. CONCLUSION: The lethal course of the disease in this elderly patient illustrates a previously not reported close temporal and clinical relationship between SHP and hyperthyroidism.

Abdominal Pain↗
PubMed1992

Anti-neutrophil antibodies in inflammatory bowel disease: prevalence and diagnostic role.

Anti-neutrophil antibodies have been shown in sera from patients with a variety of inflammatory diseases. Those reacting with components of neutrophil cytoplasm are associated with systemic vasculitis. Both nuclear and perinuclear staining patterns on human neutrophils have been reported using sera from patients with inflammatory bowel disease. We have evaluated the reactivity against human neutrophils of sera from 100 patients with inflammatory bowel disease, 14 disease controls, and 20 normal volunteers. Altogether 27/50 (54%) sera from patients with ulcerative colitis contained antibodies that reacted with cytospun ethanol fixed neutrophils compared with 5/50 (10%) from Crohn's disease (p less than 0.001) and 0/34 control sera (p less than 0.001). All seven sera from patients with proctitis alone were negative (p less than 0.01). There was no correlation between presence or titre of anti-neutrophil antibodies and either disease activity or treatment. Positive sera gave three different staining patterns on human neutrophils. The predominant pattern was perinuclear (17/32); 12 sera gave a cytoplasmic and three a homogeneous nuclear staining pattern. None of the patients or the controls had antibodies to myeloperoxidase, elastase, or serine proteinase 3, all of which are recognised by anti-neutrophil cytoplasmic antibodies. Only 2/27 sera positive by indirect immunofluorescence reacted with an extract of neutrophil primary granules. In conclusion, anti-neutrophil antibodies occur more commonly in ulcerative colitis than in Crohn's disease or control subjects and the anti-neutrophil antibodies found in inflammatory bowel disease are different from those associated with vasculitis.

Adult↗
PubMed1991

The design of a two-phase radiolabelled meal for gastric emptying studies.

A meal intended for use in gastric emptying studies must be highly reproducible, must provide a normal physiological stimulus in terms of bulk, calorie content and composition and must employ stable radiotracers which accurately reflect in their biodistribution, the fate of the two phases. This is particularly important in a field, such as gastric emptying, where so many variables may influence the results. A conventional pancake and orange juice were chosen as suitable vehicles for the solid and liquid phases. 111In-labelled resin beads were used as the solid-phase marker and a variety of 99Tcm-labelled radiopharmaceuticals including pertechnetate, DTPA and colloid forms were investigated as liquid-phase markers. Prior to administration to patients, the stability of the phases and their interactions in vitro were investigated. The use of 99Tcm-DTPA resulted in a loss of 111In from solid to liquid phase. All non-colloidal markers exhibited a tendency for adsorption onto solid phase. Colloidal markers including rhenium and antimony sulphide colloids showed the truest delineation of the liquid phase.

Drinking↗
PubMed1990

The effect of an antacid and food on the absorption of cimetidine and ranitidine.

The effect of varying doses of a liquid antacid preparation containing magnesium hydroxide, aluminum hydroxide and simethicone on the absorption of the H2-receptor antagonists, cimetidine and ranitidine, was determined in 2 groups of 11 volunteers; one group fasted and one group fed a standardized breakfast. The antacid alone caused a significant decrease in the AUC of cimetidine (24%). Similarly, concomitant antacid caused a 59% decrease in the AUC of ranitidine. There were no effects on any of the other pharmacokinetic parameters examined. The absorption of both drugs was similar in fasted and fed volunteers, but in the fed volunteers the antacid did not produce the decrease in AUC seen in the fasted volunteers. These data suggest that H2-receptor antagonists should not be taken at the same time as antacids.

Adolescent↗
PubMed1987

Studies on the mechanisms of action of activated charcoal on theophylline pharmacokinetics.

Oral administration of repeated doses of activated charcoal to volunteers and dogs significantly increased the systemic clearance of intravenously administered theophylline and decreased its elimination half-life. This effect is most likely to be due to theophylline entering the gut and being adsorbed onto the charcoal. The mechanism by which intravenously administered theophylline enters the gut has been examined. Its biliary excretion after intravenous administration to patients with T-tube biliary drainage accounted for 0.28% of the dose and a similarly small biliary excretion was found in dogs. In the latter total biliary diversion had no effect on the clearance or half-life of theophylline after intravenous administration. In two dogs the theophylline content of jejunal aspirate was comparable with that of simultaneously withdrawn venous plasma samples. These results suggest that the presence of charcoal in the gut represents a sink adsorbing theophylline entering the lumen by diffusion across the intestinal wall, and by this mechanism it increases clearance of the drug even after intravenous administration.

Animals↗
PubMed1986

Controlled clinical trial of ranitidine in bleeding peptic ulcer.

One hundred and two patients were entered into a controlled, randomized clinical trial to assess the value of ranitidine versus placebo, given immediately after entry to hospital to modify the outcome of patients admitted to hospital with acute bleeding from peptic ulceration of the stomach or duodenum. The results indicated that ranitidine could not significantly modify the blood requirements, rebleeding rate or operation rate in this patient population during the initial hospital admission.

Clinical Trials as Topic↗
PubMed1976

[Public hypertension screening and problems of individual long term control].

Four months after public screening for hypertension during the Swiss Trade Fair 1974, a random sample of 302 hypertensives referred to private practitioners were interviewed to determine the impact of the screening on longterm control through private practice. 201 hypertensives went for further blood pressure control: the previously aware did so more frequently than the previously unaware (p less than 0.01). 112 of 201 were confirmed as hypertensives by private practitioners: this occurred in 80% of aware but in only 36% of unaware patients. 94 were started on therapy. 76 of 112 (2/3) received further appointments. Another 101 hypertensives did not seek care. Main determinants were insufficient knowledge about hypertensive disease and a shorter period of formal education; half of them claimed "they felt perfectly well". In summary one third did not seek care, another third were not confirmed as hypertensive or were lost to follow-up, and only one third (50% of the aware and 10% of the unaware) were still under regular care. While community-wide screening provided an opportunity for educational compaigns and positively affected the behaviour of hypertensives who were already aware, the yield in terms of newly identified hypertensives still under control 4 months later was extremely low. Before further developing community screening programs, feasibility studies must define mechanism for improved longterm control.

Follow-Up Studies↗
PubMedDate not supplied

Examination techniques for endosonography of the anal canal.

BACKGROUND: To determine whether patient position or sphincter contraction influences sphincter thickness or defect assessment. METHODS: Anal endosonography was performed on 35 consecutive patients (30 women, five men). Twenty-five were scanned in the left lateral and prone positions, and the internal sphincter thickness was measured. In 10 patients, the internal sphincter, longitudinal muscle, external sphincter, and length of any defect were measured at rest and during anal squeeze. RESULTS: There was no significant difference in internal sphincter thickness measured in the prone and left lateral positions (95% limits of agreement, -0.12 to 0.06). The thickness of the internal sphincter, longitudinal muscle, and external sphincter at rest did not change significantly during straining (95% limits of agreement, -0.44 to 0.3, -0.28 to 0.24, and 0.33 to 0.71, respectively). The squeeze maneuver did not influence defect appearance or length (95% limits of agreement, -2.845 to 2. 379). Greater symmetry of the anterior part of the external sphincter and improved visualization of perineum was achieved in the prone position. CONCLUSION: Examination in the prone position is preferred. Squeeze maneuvers are of no diagnostic benefit.

Adult↗