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Biomedical subjects

M Baumann

Publications and source records attributed to M Baumann.

At least 145 records · Page 8Linked to original sources
PubMed1998

[Behavior linked to orodental health in 12-year-old students in the province of Kadiogo, Burkina Faso].

The authors present the results of a study carried out within the context of a diagnosis of the state of dental health among 300 twelve years old students in school in the province of Kadiogo (Burkina Faso). The data collected by questionnaires explore the range of behaviours linked to dental health: dental hygiene, eating habits, use of fluoride and use of dental health services. Half of students report that they brush their teeth at least once a day. Among them, there are 2 girls out of three, and one boy out of two. For half of the children, their mothers are the main people who teach them how to brush their teeth. For three children out of four, a tooth brush and tooth paste are the most common methods. Roughly 17% understand the usefulness of fluoride and 70% have never heard of it. Four children out of five consume sugared drinks on a daily basis. 85% say they have never been to the dentist. The information collected could serve as a base for the development and implementation of health promotion and education programmes for dental health within schools.

Beverages↗
PubMed1997

[CHARTWEL-Bronchus (ARO 97-1): a randomized multicenter trial to compare conventional fractionated radiotherapy with CHARTWEL radiotherapy in inoperable non-small-call bronchial carcinoma].

BACKGROUND: The CHART-bronchus trial sponsored by the Medical Research Council showed an improvement in survival of 10% compared to conventional fractionation to 60 Gy when patients with inoperable non-small-cell lung cancer (NSCLC) were treated with CHART to 54 Gy. At present it is not known whether this survival advantage holds when the dose of conventional treatment is increased and whether CHART can be replaced by the more practicable CHARTWEEL (CHART-weekend less). PROTOCOL OF THE TRIAL: A randomized multicenter trial of definite radiotherapy in locally advanced inoperable NSCLC was designed (ARO 97-1, Arbeitsgemeinschaft Radioonkologie der Deutschen Krebsgesellschaft). Conventional fractionation to 66 Gy (5 weekly fractions of 2 Gy) is compared with CHARTWEEL to 60 Gy (15 weekly fractions of 1.5 Gy, Monday to Friday, interval between fractions > or = 6 hours, overall treatment time 2.5 weeks). The main endpoint of the trial is overall survival. It was calculated that an entry of 665 patients is needed to detect an improvement in 2-year survival of 10%, the actual time is estimated to be 5 years or less. The trial was activated on 1.9.1997.

Adult↗
PubMed1997

[The therapeutic management of radiogenic oral mucositis].

BACKGROUND: Acute reactions of oral mucosa are a frequent side effect of radiotherapy, which often necessitates interruption of the treatment. Marked proliferation of tumor stem cells during treatment interruptions may occur in squamous cell carcinomata, which represent the majority of tumors in the head and neck area. Hence a fatal consequence of treatment breaks may be a significant decrease in tumor cure rates. Furthermore, marked acute responses frequently result in increased late sequelae ("consequential damage"). Therefore, amelioration of the mucosal response aiming at avoiding treatment breaks and at reduction of late reactions could definitely increase the therapeutic success of radiation treatment. PATIENTS AND METHOD: Various possibilities for the therapeutic management of radiation-induced oral mucositis with a symptomatic or radio- and epithelial biological background are summarized and presented systematically. RESULTS: A variety of prophylactic and therapeutic methods have been proposed for the management of acute radiation reactions of the oral mucosa. Frequently, their efficacy has been established for chemotherapy or in combination with other immunosuppressive treatments. Hence, systematical rather than local effects have to be considered. CONCLUSIONS: In general, prophylaxis of oral mucositis is mainly based on dental restoration or edentation, in combination with frequent oral hygienic measures after the meals and with antiseptic mouthwashes. Intensive personal care is recommended. The necessity of a percutaneous endoscopic gastrostoma is dependent on the status of the patient and on size and localization of the treatment area, i.e. the impairment of food uptake which is to be expected. Therapeutic intervention is restricted to local or systemic treatment of pain and local application of antimycotics and antibiotics.

Acute Disease↗
PubMed1997

Effect of irradiated volume on lung damage in pigs.

BACKGROUND AND PURPOSE: The volume dependence of radiation induced lung damage is of important clinical concern. The aim of the present study was to investigate the effect of irradiated volume on radiation pneumonitis and lung fibrosis in pigs after fractionated irradiation. MATERIALS AND METHODS: Twenty-five animals were irradiated with 10 x 14 cm2 fields to the whole right lung (about 530 cm3), while 19 animals received irradiation only to the lower part of the right lung (10 x 8 cm2 fields, about 260 cm3). The irradiations were given in five fractions over 5 days with total doses ranging from 14.3-38.0 Gy (whole lung) or 21.3-31.2 Gy (half lung) using a 60cobalt unit and an isocentric technique. Early lung damage was assessed during the first 8 weeks after the start of treatment by weekly chest radiographs and by twice weekly determinations of the breathing rate in resting animals. Fibrosis was quantified at autopsy (after 8 weeks or after 5-8 months) by histological evaluation and by determination of the hydroxyproline content of the lung tissue. Based on reference values obtained in 17 untreated control animals the experimental data were converted to quantals for probit analysis. RESULTS: The data did not indicate any significant differences for the incidence of lung damage after half lung and whole lung irradiation when injury was assessed by radiography, histology, or hydroxyproline content. However, using an increase in breathing rate as experimental endpoint, significant differences of radiation induced morbidity were observed. While none of the animals after half lung irradiation showed pathological breathing rates even after doses of 29 Gy and 31 Gy, a clear if shallow dose-response relationship with an ED50-value of 27 +/- 11 Gy (SD) was obtained after whole lung irradiation (P < 0.01). CONCLUSIONS: A volume effect can only be demonstrated for functional lung morbidity whereas induction of structural lung damage is independent of the volume irradiated.

Animals↗
PubMed1997

A pilot study of continuous ambulatory electrocardiography in patients donating blood for autologous use in elective coronary artery bypass grafting.

BACKGROUND: A pilot study was conducted to evaluate the impact of a single autologous blood donation on the presence or absence of myocardial ischemic episodes in patients with coronary artery disease. STUDY DESIGN AND METHODS: Fifty patients scheduled for elective coronary artery bypass grafting underwent two 24-hour periods of ambulatory electrocardiogram monitoring, one before and one after their first autologous blood donation. The presence or absence and the number, duration, and integral area of episodes of ST segment depression for each 24-hour monitoring period were determined. RESULTS: Forty-two patients had legible electrocardiogram recordings for both monitoring periods. Of these, 36 patients (86%) had at least one episode of ST segment depression during any monitoring period. The number of patients who had at least one episode of ST segment depression before donation was not significantly different from the number of those who had at least one episode after donation (31 and 33 patients, respectively; p = 0.73). CONCLUSION: Donating a unit of blood had no demonstrable effect on the presence or absence of myocardial ischemic episodes in this sample of 42 autologous blood donors with coronary artery disease. The results of this study should be validated in further trials.

Adolescent↗
PubMed1997

Sphingolipid activator proteins (SAPs) in neuronal ceroid lipofuscinoses (NCL).

Based on the predominant component of the storage material the neuronal ceroid lipofuscinoses (NCL) can be divided into two categories: one storing mitochondrial ATP synthase subunit c and the other storing sphingolipid activator proteins (SAPs). The latter group is represented by the human infantile NCL (INCL), a congenital ovine NCL, and a canine NCL. Small amounts of SAPs also accumulate in most other forms of NCL. The SAPs, their functions and occurrence in different forms of NCL, as well as the relationship between SAPs and palmitoyl protein thioesterase, an enzyme implicated in INCL, are discussed.

ATP Synthetase Complexes↗
PubMed1997

Variant late infantile neuronal ceroid-lipofuscinosis: pathology and biochemistry.

The neuronal ceroid-lipofuscinoses (NCL) are among the most common inherited neurodegenerative disorders of childhood. The genomic defect causing a variant late infantile neuronal ceroid-lipofuscinosis (vLINCL, also called CLN-5 or variant Jansky-Bielschowsky disease) has recently been localized to chromosome 13q22, thus delineating this disease as a separate entity. This particular form of NCL is clinically well defined, but lacks pathomorphological and biochemical description. The present analyses indicate that subunit c of the mitochondrial ATP synthase is the major protein in vLINCL brain storage cytosomes. These cytosomes also contain minor amounts of sphingolipid activator proteins (SAPs). The immunohistological distribution of subunit c and SAPs in the central nervous system (CNS) and visceral tissues closely resembles that of classical LINCL. Thus, despite clinical differences and the fact that various forms of NCL are caused by different genetic defects, variant and classical LINCL as well as juvenile NCL are all characterized by pronounced lysosomal accumulation of the same hydrophobic protein, subunit c of the mitochondrial ATP synthase.

Adult↗
PubMed1996

Inhibition of Alzheimer's amyloidosis by peptides that prevent beta-sheet conformation.

Amyloid beta-peptide (A beta) is a major fibrillar component of neuritic plaques in Alzheimer's disease (AD) brains and is related to the pathogenesis of the disease. We hypothesized that amyloid formation could be inhibited by peptides homologous to A beta (position 17-21) with a similar degree of hydrophobicity, but with a very low propensity to adopt a beta-sheet conformation by incorporating proline residues (anti-beta-sheet peptides or beta-sheet inhibitors). An 11-residue peptide with these characteristics binds to A beta, inhibits A beta fibril formation and partially disaggregates preformed fibrils in vitro. Shorter anti-beta-sheet peptides and analogs containing D-amino acids are also able to inhibit A beta fibrillogenesis. The latter are more resistant to proteolytic degradation and may serve as a starting point to design more efficient peptides derivatives to inhibit amyloidogenesis in vivo.

Alzheimer Disease↗
PubMed1996

Structural composition and functional characterization of soluble CD59: heterogeneity of the oligosaccharide and glycophosphoinositol (GPI) anchor revealed by laser-desorption mass spectrometric analysis.

CD59 (protectin) is a glycophosphoinositol (GPI)-anchored inhibitor of the membrane attack complex of complement found on blood cells, endothelia and epithelial cells. In addition to the lipid-tailed CD59, soluble lipid-free forms of CD59 are present in human body fluids. We have investigated the detailed structural composition of the naturally occurring soluble urinary CD59 (CD59u) using peptide mapping, anion-exchange chromatography, sequential exoglycosidase digestion and matrix-assisted laser-desorption mass spectrometry (MALDI-MS). CD59u exhibited an average M(r) of 12444 in MALDI-MS. Mass analysis of the isolated C-terminal peptide (T9) indicated that a GPI-anchor (at Asn-77) without an inositol-associated phospholipid was present in soluble CD59u. By using residue-specific exoglycosidases, chemical modification and MALDI-MS structures of seven different GPI-anchor variants were determined. Variant forms of the anchor had deletions and/or extensions of one or more monosaccharide units. Sialic acid linked to an N-acetylhexosamine-galactose arm was found in two GPI-anchor variants. The N-linked carbohydrate side chain of CD59u (at Asn-18) also displayed considerable heterogeneity. The predominant oligosaccharide chains were fucosylated biantennary and triantennary complexes with variable sialylation. Mono Q anion-exchange chromatography resolved urinary CD59 into nine different fractions that bound equally well to the terminal complement SC5b-8 complexes. Despite binding to C5b-8, soluble CD59u inhibited complement lysis at an approx. 200-fold lower efficiency than erythrocyte CD59. These results document the structural heterogeneity of both the GPI anchor and N-linked oligosaccharide of CD59 and demonstrate that the phospholipid tail is needed for the full functional activity of CD59. The site of cleavage between the diradylglycerol phosphate and inositol suggests that a mammalian phospholipase D could be involved in the solubilization of GPI-anchored proteins.

Amino Acid Sequence↗
PubMed1996

Micropreparative gel electrophoresis of low-molecular-weight peptides: purification of highly insoluble amyloid peptide fragments.

We have used the continuous-elution micropreparative gel electrophoresis device described by Baumann and Lauraeus (Anal. Biochem. 214, 142-148, 1993) to purify low-molecular-weight peptide fragments from in-gel digested standard proteins as well as highly in-soluble amyloid peptides. Alzheimer's amyloid beta-peptide, gelsolin-derived amyloid peptide of the Finnish type, and a novel amyloid of the British type were purified from either homogenized brain or kidney tissue material to a high degree of purity in a single run. Using the high resolving capacity of the Tris-Tricine-SDS buffer system of Schaegger and von Jagow (Anal. Biochem. 166, 368-379, 1978) we were able to isolate two synthetic peptides with M(r)4329 and 3284, differing only by 1045 in mass. The total peptide recovery, as determined by amino acid sequence analysis and scanning densitometry, ranged between 60 and 80%. In order to demonstrate the utility of this technique we subjected some of the purified peptides to direct N-terminal amino acid sequence analysis, mass spectrometry, microbore high-performance liquid chromatography, and immunochemical studies. Our results show that micropreparative gel electrophoresis is an effective tool for the isolation of not only larger polypeptides but also small peptide fragments in a form suitable for further biological use.

Adaptor Proteins, Signal Transducing↗
PubMed1996

HB-GAM is a cytokine present in Alzheimer's and Down's syndrome lesions.

The distribution of heparin binding growth associated molecule (HB-GAM) in the cerebral amyloidoses of Alzheimer's disease (AD) and Down's syndrome (DS), conditions characterized by the deposition of amyloid beta (A beta), was investigated immunohistochemically. Antibodies to HB-GAM, a cytokine which plays an important role in brain development and maturation, showed strong immunoreactivity with senile plaques in both AD and DS. Anti-HB-GAM reacted with pre-amyloid lesions, but only when markers of dystrophic neurites were present. The presence of HB-GAM in AD brains, but not in control brains, was confirmed by Western blotting. We suggest that the presence of HB-GAM in A beta lesions is a marker of neuronal injury.

Adolescent↗
PubMed1996

Morphometry of the aging female rat urethra.

Muscles in the limbs change with age, but the aging process of urethral muscles is unknown. Therefore, we compared smooth and striated muscle content in the female rat urethra in young (12 month) and old (32 month) animals, using immunochemical techniques. All the striated skeletal fibers at both ages contain slow myosin. Urethral diameter does not change with age (young, 1.44 +/- 0.08 mm; old, 1.46 +/- 0.10 mm, n = 5), nor does the external sphincter width (young, 0.088 +/- 0.016 mm; old, 0.080 +/- 0.017 mm, n = 5). Neither smooth nor skeletal muscle volume in the urethra is changed with age (skeletal: young, 20.72 +/- 2.94%; old, 19.95 +/- 2.35%. Smooth: young, 22.26 +/- 2.98%; old, 26.75 +/- 2.35%, n = 5). The external striated sphincter is separate and distinct from the pubococcygeal region of the levator ani muscle, but is closely apposed to another layer of longitudinally oriented fibers into the vaginal musculature. The morphometric analysis shows no difference in urethral architecture in aging female rats.

Aging↗
PubMed1996

Data management of a pneumonia screening algorithm in Veterans Affairs Medical Centers.

The Veterans Affairs External Peer Review Program (EPRP) reviews patient care episodes in Veterans Affairs Medical Centers (VAMCs) across the United States. This review process uses screening algorithms, followed by peer review, to identify deviations in the care provided by the VAMCs. A schematic model of the case selection, data acquisition at each VAMC, data flow between the VAMCs and the West Virginia Medical Institute (WVMI), data processing at WVMI, and the peer review process are given. A model pneumonia clinical practice guideline was generated by an expert panel of physicians external to the VAMCs. This guideline identifies benchmark criteria that reflect the clinical standards for diagnosing and treating hospitalized pneumonia patients. A screening algorithm was then designed, tested, and implemented to identify deviations in the quality of care delivered by VAMCs to hospitalized pneumonia patients.

Adolescent↗
PubMed1996

Membrane skeleton involvement in cell fusion kinetics: a parameter that correlates with erythrocyte osmotic fragility.

Spectrin levels in erythrocytes have been related to several biomechanical and biophysical membrane properties essential to the survival and function of the cell. Populations of erythrocytes display a natural and finite range of sensitivities to osmotic shock that has been directly correlated, in studies from other laboratories, to the presence of spectrin. We used a procedure to isolate subpopulations of 1) the osmotically most sensitive and 2) the osmotically most resistant erythrocyte membranes in an attempt to select for membranes enriched and depleted in spectrin (and/or a related component). The mechanical function of the spectrin-based membrane skeleton was further explored in these two subpopulations by searching for any effect on the time-dependent increase in fusion zone diameter in pairs of electrofused erythrocyte ghosts as a model for cell fusion. The results clearly show that the diameter expansions in fusions of membranes from osmotically resistant erythrocytes are faster in the early stage (up to 9 to 10 s after fusion) but do not thereafter expand as far as in fusions of membranes from osmotically sensitive membranes.

Animals↗
PubMed1996

Oxymetholone promotes weight gain in patients with advanced human immunodeficiency virus (HIV-1) infection.

The effect of the testosterone derivative oxymetholone alone or in combination with the H1-receptor antagonist ketotifen, which has recently been shown to block tumour necrosis factor alpha (TNF alpha), on weight gain and performance status in human immunodeficiency virus (HIV) patients with chronic cachexia was evaluated in a 30-week prospective pilot study. Thirty patients were randomly assigned to either oxymetholone monotherapy (n 14) or oxymetholone plus ketotifen (n 16). Patients receiving treatment were compared with a group of thirty untreated matched controls, who met the same inclusion criteria. Body weight and the Karnofsky index, which assesses the ability to perform activities of daily life, and several quality-of-life variables were measured to evaluate response to therapy. The average weight gain at peak was 8.2 (SD 6.2) kg (+ 14.5% of body weight at study entry) in the oxymetholone group (P < 0.001), and 6.1 (SD 4.6) kg (+10.9%) in the combination group (P < 0.005), compared with an average weight loss of 1.8 (SD 0.7) kg in the untreated controls. The mean time to peak weight was 19.6 weeks in the monotherapy group and 20.8 weeks in the combination group. The Karnofsky index improved equally in both groups from 56% before to 67% after 20 weeks of treatment (P < 0.05). The quality of life variables (activities of daily life, and appetite/nutrition) improved in 68% (P < 0.05) and 91% (P < 0.01) of the treated patients respectively. Oxymetholone was safe and promoted weight gain in cachectic patients with advanced HIV-1 infection. The addition of ketotifen did not further support weight gain. These results suggest the need for a randomized, double-blind, placebo-controlled multicentre trial.

Acquired Immunodeficiency Syndrome↗