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Biomedical subjects

J Pfeiffer

Publications and source records attributed to J Pfeiffer.

At least 19 recordsLinked to original sources
PubMed2001

Intrahousehold resource allocation and child growth in Mozambique: an ethnographic case-control study.

This study examines the effect of intrahousehold cash income control and decision-making patterns on child growth in the rural town of Sussundenga in Manica Province, Mozambique. A case-control study design was used to examine the influence of men's and women's disaggregated cash incomes on child growth. The research tested whether greater maternal share of household cash income was associated with (1) increased maternal decision-making and bargaining power in the household, and (2) better child growth. Fifty case households, with children 1-4 years old exhibiting poor growth, were matched with 50 control households of similar socioeconomic status in which all children under five demonstrated healthy growth. Data were gathered on gender-specific income generation and expenditure, specific intrahousehold allocation processes, diet, and sociodemographic variables using a formal survey. Key informant interviews, focus groups, and observation over one year provided ethnographic context for the case-control findings. Case-control differences were analyzed using McNemar's test, paired t-test, and conditional logistic regression. In spite of matching households for socioeconomic status, control household incomes were still slightly greater than cases. Male spouse income was also higher among controls while maternal income, and maternal proportion of household income, were not significantly different. Household meat, fish and poultry consumption, and maternal education were significantly greater among control households than cases. Greater maternal share of household income was not associated with greater maternal decision-making around cash. However, mothers must spend what little cash they earn on daily food supplies and usually request additional cash from spouses to cover these costs. There is evidence that if mothers earn enough to cover these socially prescribed costs, they can spend cash for other needs. Above this threshold, women's earnings may confer more bargaining power. The research also revealed a nuclearization of households, attenuation of community bonds of mutual aid, and increasing importance of cash for survival.

Adult↗
PubMed2000

The PDZ-interacting domain of cystic fibrosis transmembrane conductance regulator is required for functional expression in the apical plasma membrane.

Polarization of cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-activated chloride channel to the apical plasma membrane in epithelial cells is critical for vectorial chloride transport. Previously, we reported that the C terminus of CFTR constitutes a PDZ-interacting domain that is required for CFTR polarization to the apical plasma membrane and interaction with the PDZ domain-containing protein EBP50 (NHERF). PDZ-interacting domains are typically composed of the C-terminal three to five amino acids, which in CFTR are QDTRL. Our goal was to identify the key amino acid(s) in the PDZ-interacting domain of CFTR with regard to its apical polarization, interaction with EBP50, and ability to mediate transepithelial chloride secretion. Point substitution of the C-terminal leucine (Leu at position 0) with alanine abrogated apical polarization of CFTR, interaction between CFTR and EBP50, efficient expression of CFTR in the apical membrane, and chloride secretion. Point substitution of the threonine (Thr at position -2) with alanine or valine had no effect on the apical polarization of CFTR, but reduced interaction between CFTR and EBP50, efficient expression of CFTR in the apical membrane as well as chloride secretion. By contrast, individual point substitution of the other C-terminal amino acids (Gln at position -4, Asp at position -3 and Arg at position -1) with alanine had no effect on measured parameters. We conclude that the PDZ-interacting domain, in particular the leucine (position 0) and threonine (position -2) residues, are required for the efficient, polarized expression of CFTR in the apical plasma membrane, interaction of CFTR with EBP50, and for the ability of CFTR to mediate chloride secretion. Mutations that delete the C terminus of CFTR may cause cystic fibrosis because CFTR is not polarized, complexed with EBP50, or efficiently expressed in the apical membrane of epithelial cells.

Animals↗
PubMed2000

Incorporation of chromium carbenes in a silica matrix by sol-gel processing: application to aminolysis of alkoxycarbene complexes

Chromium carbene complexes have been immobilized in a silica matrix by sol-gel processing based on the polycondensation of (trialkoxy)silylethylphosphane ligands and tetraalkoxysilanes. The microstructure of the material obtained depends on the gelation conditions. In situ gelation of alkoxy- or aminocarbene complexes with tetramethoxysilane (TMOS) affords mesoporous materials with a homogeneous distribution of the metal complex. The metal carbene moiety is accessible for small substrates as demonstrated for the aminolysis of the incorporated methoxy(phenyl)carbene complex which slows down with increasing bulk of the amine.

Journal Article↗
PubMed1999

A caspase inhibitor decreases oxidized low-density lipoprotein-induced apoptosis in bovine endothelial cells.

BACKGROUND: Apoptosis is a pathway of cell death orchestrated by a family of proteases called caspases. Oxidized low density lipoprotein (oxLDL) is a putative cause of atherogenesis. We examined the effect of oxLDL on endothelial cell (EC) apoptosis and the ability of a caspase antagonist to inhibit oxLDL-induced EC injury. METHODS: Bovine ECs were plated at a concentration of 5.0 x 10(5) cells/ml and exposed to LDL oxidized by ultraviolet radiation at a concentration of 100 microgram oxLDL/ml for 20 h. Some ECs were pretreated with an irreversible caspase inhibitor (ZVAD). Samples were analyzed histologically. Apoptosis was measured using the Annexin V assay (flow cytometry) which detects phosphatidylserine on plasma membranes and confirmed by TUNEL assay (flow cytometry). Statistical assessments were performed using ANOVA. RESULTS: ECs treated with LDL were morphologically similar to untreated cells. Cells treated with oxLDL demonstrated cytoplasmic shrinkage, plasma membrane blebbing, chromatin condensation, and loss of adhesion. These effects were diminished after pretreatment with the caspase inhibitor ZVAD. The Annexin V assay showed: (a) cells exposed to LDL had a 12 +/- 1% apoptosis rate, (b) exposure to oxLDL induced apoptosis in 30 +/- 0.3% of the cells, and (c) pretreatment with the caspase inhibitor ZVAD decreased the oxLDL-induced apoptosis to 16 +/- 1% (P < 0.05). This decrease in apoptosis was also reflected by an increase in the percentage of alive cells from 34 +/- 7% after oxLDL exposure to 55 +/- 6% after apoptosis inhibition with ZVAD. TUNEL assay demonstrated a 2.5-fold reduction in mean fluorescence intensity between cells treated with oxLDL alone and those treated with ZVAD, suggesting a significant decrease in apoptosis in the latter group. CONCLUSIONS: We conclude that treatment of bovine ECs with oxLDL induces apoptosis which can be significantly reduced by a specific caspase inhibitor.

Amino Acid Chloromethyl Ketones↗
PubMed1999

Dental CAD/CAM technologies: the optical impression (II).

This article, has explained the principles and characteristics of the optical impression, such as is used in the Cerec dental CAD/CAM system, and discussed the limitations and perspectives for future developments of the technique. Optical methods of measurement are clearly capable of satisfying the basic requirements of a direct CAD/CAM procedure for fabricating restorations for individual teeth. Further improvements in the technique beyond the level that Cerec 2 offers today are conceivable but still in the far future because they require significant improvements of the basic components. These developments can be expected to enhance the accuracy of measurement and ease of operation, as well as permitting the measurement of several teeth at once for the fabrication of fixed partial dentures.

Calibration↗
PubMed1999

Developing a culture of lifelong learning in a library environment.

Between 1995 and 1996, the Annette and Irwin Eskind Biomedical Library (EBL) at Vanderbilt University Medical Center (VUMC) radically revised the model of service it provides to the VUMC community. An in-depth training program was developed for librarians, who began to migrate to clinical settings and establish clinical librarianship and information brokerage services beyond the library's walls. To ensure that excellent service would continue within the library, EBL's training program was adapted for library assistants, providing them with access to information about a wide variety of work roles and processes over a four to eight-month training period. Concurrently, customer service areas were reorganized so that any question--whether reference or circulation--could be answered at any of four service points, eliminating the practice of passing customers from person to person between the reference and circulation desks. To provide an incentive for highly trained library assistants to remain at EBL, management and library assistants worked together to redesign the career pathway based on defined stages of achievement, self-directed participation in library-wide projects, and demonstrated commitment to lifelong learning. Education and training were the fundamental principles at the center of all this activity.

Career Mobility↗
PubMed1995

[Grinding precision and accuracy of the fit of Cerec-2 CAD/CIM inlays].

The grinding precision of one Cerec-1 (C1) and one Cerec-2 (C2) CAD/CIM unit each was evaluated using standardized inlay-like (mod) samples (n = 40) of Vita Cerec Mk II porcelain and Dicor MGC glass ceramic. Typical dimensions (B, E, F, H) of the sampleS were measured and the standard deviations (SD) analysed statistically using the F-test. SD of C2-machined sample dimensions were significantly lower using both Vita, B: p < 0.05; E: p < 0.001; F: p < 0.001; H: p < 0.001, and Dicor MGC, B: p < 0.05; E: p < 0.001; F: p < 0.001; H: p < 0.01, than those machined with C1, indicating a strong improvement of grinding precision of C2 compared to C1. Accuracy of fit to human molar cavities of mod inlays machined with C1 (n = 6) and C2 (n = 6) was evaluated using a scanning electron microscope with 100x magnification. The width of the interfacial luting gap was generally lower in C2 inlays (56 +/- 27 microns) than with C1 (84 +/- 38 microns). Significant differences (t-test) were seen in margin sections "cervical line angles above CEJ" (C1 = 124 +/- 44/C2 = 59 +/- 30 microns, p < 0.05), "cervical line angles at CEJ" (C1 = 109 +/- 55/C2 = 67 +/- 27 microns, p < 0.05) and "gingival margin above CEJ" (C1 = 81 +/- 32 microns/C2 = 31 +/- 18 microns, p < 0.05).

Ceramics↗
PubMed1994

[Deinstitutionalization of psychiatric care: the post-war process in developed countries].

The authors pay their attention to the transformation of the psychiatric care which has formed in many industrial countries after the second world war. It concerns namely the deinstitutionalization process together with a development of the community psychiatric care, or the reduction process of the psychiatric bed number simultaneously with a spread of the community mental health facilities. The authors follow these changes namely in Great Britain, USA and Italy. They also discuss some theoretical problems (functions of the community psychiatry, model programs) and compare the positive and negative influences of the changes mentioned above on the society.

Community Mental Health Services↗
PubMed1993

Cytoskeleton of living, unstained cells imaged by scanning force microscopy.

Subsurface cytoskeletal structure can be visualized in either fixed or living mammalian cells in aqueous medium with approximately 50 nm resolution using the Scanning Force Microscope (SFM). In living cells, changes in cell topography, or subsurface cytoskeleton caused by the introduction of drugs (colchicine) or cross-linking of surface receptors (by antibodies against IgE bound to the IgE receptor) can be followed in time. Contrast in SFM images of cell surfaces result from both topographic features of the cell and from variations in cell surface "stiffness". The SFM is therefore capable of measuring local compliance and stress in living cells, and so should make it possible to map the cytoskeletal forces used to generate cell motions and changes in cell shape.

Animals↗
PubMed1991

[Development of psychiatric disability in psychotics and their rehabilitation].

The authors describe the results of a 12-month follow up of a group of patients who had an attack of functional psychosis. They paid attention to their professional work, course of the disease and social sequelae of the disease. The authors assessed also predictors of satisfactory future of professional activities by clinical methods as well as by selected psychological tests. They confirmed the effectiveness of aimed rehabilitation and resocialization care in patients with a chronic course of the disease and with residual postpsychotic symptoms.

Adolescent↗
PubMed1989

[Development and conceptual program in the practice of rehabilitation medicine].

The author draws attention to organizational short-comings in the development of rehabilitation in the CSSR, which are to a considerable extent due to the incorrect use of the term rehabilitation. It is used as a synonym of physiatrics, as regeneration or even recreation and as defined by WHO. Despite many satisfactory instructions and Government decrees quoted by the author, in practice the continuity of therapeutic and occupational rehabilitation is not satisfactory. The author mentions interrelations between assessment of work capacity, orthopaedic prosthetics and rehabilitation medicine. He explains the right to work ensured by the constitution with respect to rehabilitation. He expects favourable results which will ensure from the fusion of the health department and the department of labour and the department of labour and social affairs within the framework of economic reconstruction.

Czechoslovakia↗
PubMed1988

[Mitochondrial encephalomyopathy: clinical aspects, CT morphology and neuropathology].

Basing on the example of two cases, the clinical and morphological variability of mitochondrial encephalomyopathies is demonstrated. Both patients were of short build, and the clinical signs and symptoms were dementia, ataxia, epilepsy and hardness of hearing, whereas signs of myopathy were very mild or absent. Computed tomography showed infratentorial pronounced atrophy of the brain and basal ganglia calcifications, in one case additionally ischemic infarctions, as can be seen in "mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes syndrome" (MELAS). A CT follow-up over 8 years with a progression of the abnormalities parallel to the progressive clinical course is demonstrated. Besides typical "ragged red fibres-myopathy" different abnormalities of mitochondria were seen by the electron microscope. One of the patients died; he had exceptional pathological-anatomical findings with mitochondrial cardiomyopathy, angioma and necrotising encephalopathy of Leigh's type. The two case reports show that in patients with such multisystemic neurological signs and CT-findings mitochondrial encephalomyopathy should be considered and a muscle biopsy should be performed.

Adult↗
PubMed1988

[Methohexital/alfentanil-thiopental/alfentanil for total intravenous anesthesia for direct laryngoscopy with 100% O2 jet ventilation].

For the direct laryngoscopy and microscopic examination of the larynx with exploratory excision and pulpectomy using low frequency jet-ventilation with 100% oxygen we used total intravenous anaesthesia with a strong acting opioid and a barbiturate. Because the achievement of sufficient reflexes and a high degree of vigilance postoperatively are to be aimed, Methohexitone (M) and Thiopentone (T) were investigated in the regard of the suppression of vigilance in the postoperative period. 40 patients were randomly assigned to the group M (n = 20) or T (n = 20). The evening before operation, an intelligence test and a syndrome-short-test (SST) were performed for the measurement of attention and memory (functional psychosis). The patients received 2 mg Flunitrazepam orally and transdermal Scopolamine. On the day of operation the patients received 1 mg Lormetazepam orally for premedication. Anaesthesia was induced with 2 mg Alcuronium, 1 mg Alfentanil, 1.4 mg/kg bodyweight M respectively 5 mg/kg bodyweight T and 1.4 mg/kg bodyweight Succinylcholine. Immediately before laryngoscopy the patients received 2-4 mg Alfentanil. Muscle relaxation was achieved by an infusion with Succinylcholine using relaxometry. Methohexitone respectively Thiopentone were administered by infusion depending on clinical signs indicating insufficient anaesthesia. The following parameters were measured: Blood pressure, heart rate, duration of operation and anaesthesia, parameters of vigilance 30, 60 and 120 minutes after operation (SST) and the ability of performance. The groups were comparable with respect to all data except the parameters of vigilance. The patients receiving M were significantly more vigilant 30 min., 60 min. (SST) and 120 min (SST) after the end of anaesthesia than patients receiving T (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗