Search PubMed⌕ Search

Biomedical subjects

M Muller

Publications and source records attributed to M Muller.

At least 109 records · Page 6Linked to original sources
PubMed2000

The quality of nursing service management in South African hospitals.

The purpose of this study is to determine--explore and describe--the quality of nursing service management in South African hospitals. A combined qualitative and quantitative pre- and post-test research strategy, in accordance with the COHSASA programme, was utilised. The hospitals implement the national standards during the preparatory phase, after having entered into an agreement with COHSASA. They determine their baseline status by means of an assisted self-evaluation. This is followed by an external survey phase where the hospital's compliance with the standards is evaluated. The nursing service is one of the professional services included in the accreditation programme. Their performance is compared with selected other professional services and their compliance with the core elements is also evaluated. The nursing services in South Africa are compliant with the national standards. The deficiencies are mainly within the quality improvement programmes that require further development and refinement.

Accreditation↗
PubMed2000

Transformation management of primary health care services in two selected local authorities in Gauteng.

The transformation of health services in South Africa today is governed by the political, policy and legislative frameworks. This article focuses on the transformation of a primary health care service within a local authority in Gauteng. The purpose with this article is to explore and describe the perceptions (expectations and fears) of selected managers employed in this primary health care service. The results are utilised to compile a strategy (framework) for transformation management and leadership within the primary health care service. A qualitative research design was utilised and the data was collected by means of individual interviews with selected managers in the service, followed by a content analysis. The expectations and fears of managers focus mainly on personnel matters, community participation/satisfaction, salaries and parity, inadequate stocks/supplies and medication, the deterioration of quality service delivery and the need for training and empowerment. These results are divided into structure, process and outcome dimensions and are embodied in the conceptual framework for the transformation and leadership strategy. It is recommended that standards for transformation management be formulated and that the quality of transformation management be evaluated accordingly.

Adaptation, Psychological↗
PubMed2000

[Isolated sphenoiditis treated with endoscopic surgery in a child].

Isolated sphenoiditis in childhood is a rare entity which is often very difficult to diagnose with conventional techniques. The authors present a case of sphenoiditis in nine years old boy, where chronic rhinitis and persistent cephalqia where the main symptoms. The diagnosis was made on the base of computed tomography and nasal endoscopy. Because of lack of effect after pharmacological treatment the child was submitted to endoscopic surgery--sphenoethmoidectomy, which resulted it total recovery. The diagnosis, indications to computed tomography of paranasal sinuses in children, options of both conservative and surgical treatment and possible complications of the diseases are discussed.

Child↗
PubMed2000

The effectiveness of osteopathic manipulative treatment as complementary therapy following surgery: a prospective, match-controlled outcome study.

CONTEXT: Osteopathic manipulative treatment has been reported to relieve a variety of conditions, but no studies have examined the outcome effects of osteopathic manipulative treatment as a complementary modality for treating musculoskeletal problems during postoperative recovery. OBJECTIVE: To assess osteopathic manipulative treatment as a complementary therapy for patients undergoing elective knee or hip arthroplasty. DESIGN: Prospective, single-blinded, 2-group, match-controlled outcome study. SETTING: Osteopathic teaching hospital. PATIENTS: Of 166 eligible patients, 38 were assigned to a treatment group and matched with 38 control subjects. INTERVENTION: The treatment group received osteopathic manipulative treatment on postoperative days 2 through 5. MAIN OUTCOME MEASURES: Days to independent negotiation of stairs, distance ambulated, supplemental intramuscular analgesic use, length of hospital stay, and patients' perceptions of treatment. RESULTS: Compared to control subjects, the intervention group negotiated stairs 20% earlier (mean = 4.3 postoperative days, SD = 1.2; control subjects 5.4, SD = 1.6, P = .006) and ambulated 43% farther on the third postoperative day (mean = 24.3 m, SD = 18.3; controls = 13.9, SD = 14.4, P = .008). The intervention group also required less analgesia, had shorter hospital stays, and ambulated farther on postoperative days 1, 2, and 4. CONCLUSIONS: Patients receiving osteopathic manipulative treatment in the early postoperative period negotiated stairs earlier and ambulated greater distances than did control group patients.

Aged↗
PubMed2000

[Standards for performance appraisal of academic staff at a nursing college].

The purpose with this research is to formulate standards for performance appraisal of academic staff within a nursing college. A qualitative exploratory and descriptive research strategy was utilized, within the context of Gauteng nursing colleges. The conceptual framework on which the standards are based, was developed by exploring and describing existing job descriptions of academic staff (Chief Professional Nurse) employed in nursing colleges, as well as the expectations of academic staff regarding performance appraisal in the college. These results were exposed to a literature control prior to the writing of final statements and a conceptual framework for the formulation of these standards. The standards are divided into three main dimensions, viz. the organisational climate within the nursing college, the purpose of performance appraisal and finally the process of performance appraisal. It is recommended that these standards be implemented in nursing colleges and exposed to further validity studies.

Employee Performance Appraisal↗
PubMed2000

[The vestibular system and migraine in children].

Migraine in childhood is relatively common disease. Although clinical practice and scientific publications recognize frequent association of migraine and vestibular disorders, relationships have yet to be well defined. In present study the vestibular function was extensively tested in 20 children suffering from migraine. All the patients underwent complete neurootological examination including tonal threshold audiometry, testing of vestibulo-spinal reflexes--Romberg and Unterberger-Fukuda tests, Dix-Halpike test for BPPV, videonystagmography. On videonystagmography each patient was evaluated regarding: calibration, spontaneous nystagmus, gaze nystagmus, eye tracking test, optokinetic and positional nystagmus, and caloric testing. The same procedure have been performed regarding control group comprised of 15 healthy. All the patients with migraine presented abnormalities in vestibular testing. Analysis of the results showed that: functional state of structures forming both visuo-ocular and vestibulo-ocular structures was altered in all the migraine patients evaluated in the study, pathological findings suggest mainly central localisation of vestibular dysfunction in children suffering from migraine, the number of pathological VNG findings seems not to be correlated with the type of migraine.

Adolescent↗
PubMed2000

[Perceptions of nursing service managers in the South African Military Health Service on their level of motivation].

The process of transformation in the South African Military Health Services, has influenced the nursing service managers' level of motivation and the following research question is applicable: what are the perceptions of the nursing service managers within the South African Military Health Services on their level of motivation? The purpose with this study was to explore and describe the perceptions of nursing service managers on their level of motivation within these health services. A qualitative research design was utilized and four focus group interviews were conducted with 33 nursing service managers country wide. The transcribed interviews were exposed to a content analysis. The results confirm that the level of motivation amongst these nursing service managers is low. The demotivators relate mainly to the following: inadequate acknowledgement, job insecurity in relation to the future, problems with the process of integration, transformation and rationalization, problems with management, many labour related issues, poor/inadequate communication, inadequate support, increased work load, poor physical environment, negative publicity and poor self motivation. Although there were a few motivators identified, they were of less importance. These results were interpreted within Herzberg's motivation theory to identify the hygiene/maintenance factors and to assess whether the important motivators were in place. During any process of change, and/or when the level of motivation amongst employees is low, it is important to adequately manage the environment (hygiene/maintenance factors within the Herzberg theory). But it is even more important to ensure that the motivators are in place or to intensify them. It is therefore recommended that a motivation strategy, based on the Herzberg theory as well as the Hackman-Oldham job enrichment model, be developed, implemented and evaluated.

Attitude of Health Personnel↗
PubMed1999

Transcription factor pit-1 expression is modulated upon seasonal acclimatization of eurythermal ectotherms: identification of two pit-1 genes in the carp.

A second Pit-1 gene in carp (Cyprinus carpio), including the complete structural gene and 1.1 kb of promoter region, was identified and completely sequenced. The exon-intron structure was determined, and reverse transcription-polymerase chain reaction (RT-PCR) experiments suggest that only one Pit-1 splice variant is present in carp pituitary. The effect of seasonal acclimatization on the extent of Pit-1 gene expression was studied in summer- and winter-acclimatized carp. Quantitative RT-PCR analysis revealed a clear increase of Pit-1 mRNA in the pituitaries from summer-acclimatized carp compared with the winter-adapted fish. In situ hybridization of pituitary gland sections with riboprobes representing the complete 5'-transactivating region of carp Pit-1 depicted a significantly higher Pit-1 mRNA level in the rostral pars distalis of the summer-acclimatized fish where prolactin is expressed in a manner that resembles the seasonal increase observed in the proximal pars distalis and the pars intermedia. The cell- and temporal-specific transcription of Pit-1 supports its role in the molecular mechanisms that underly the acclimatization process undergone by eurythermal fish as a result of the physical effects of seasonal changes on their habitat.

Amino Acid Sequence↗
PubMed1999

The functions of the flavin contact residues, alphaArg249 and betaTyr16, in human electron transfer flavoprotein.

Arg249 in the large (alpha) subunit of human electron transfer flavoprotein (ETF) heterodimer is absolutely conserved throughout the ETF superfamily. The guanidinium group of alphaArg249 is within van der Waals contact distance and lies perpendicular to the xylene subnucleus of the flavin ring, near the region proposed to be involved in electron transfer with medium chain acyl-CoA dehydrogenase. The backbone amide hydrogen of alphaArg249 is within hydrogen bonding distance of the carbonyl oxygen at the flavin C(2). alphaArg249 may modulate the potentials of the two flavin redox couples by hydrogen bonding the carbonyl oxygen at C(2) and by providing delocalized positive charge to neutralize the anionic semiquinone and anionic hydroquinone of the flavin. The potentials of the oxidized/semiquinone and semiquinone/hydroquinone couples decrease in an alphaR249K mutant ETF generated by site directed mutagenesis and expression in Escherichia coli, without major alterations of the flavin environment as judged by spectral criteria. The steady state turnover of medium chain acyl-CoA dehydrogenase and glutaryl-CoA dehydrogenase decrease greater than 90% as a result of the alphaR249Ks mutation. In contrast, the steady state turnover of short chain acyl-CoA dehydrogenase was decreased about 38% when alphaR249K ETF was the electron acceptor. Stopped flow absorbance measurements of the oxidation of reduced medium chain acyl-CoA dehydrogenase/octenoyl-CoA product complex by wild type human ETF at 3 degrees C are biphasic (t(1/2)=12 ms and 122 ms). The rate of oxidation of this reduced binary complex of the dehydrogenase by the alphaR249K mutant ETF is extremely slow and could not be reasonably estimated. alphaAsp253 is proposed to function with alphaArg249 in the electron transfer pathway from medium chain acyl-CoA dehydrogenase to ETF. The steady state kinetic constants of the dehydrogenase were not altered when ETF containing an alphaD253A mutant was the substrate. However, t(1/2) of the rapid phase of oxidation of the reduced medium chain acyl-CoA dehydrogenase/octenoyl-CoA charge transfer complex almost doubled. betaTyr16 lies on a loop near the C(8) methyl group, and is also near the proposed site for interflavin electron transfer with medium chain acyl-CoA dehydrogenase. The tyrosine residue makes van der Waals contact with the C(8) methyl group of the flavin in human ETF and Paracoccus denitrificans ETF (as betaTyr13) and lies at a 30 degrees C angle with the plane of the flavin. Human betaTyr16 was substituted with leucine and alanine residues to investigate the role of this residue in the modulation of the flavin redox potentials and in electron transfer to ETF. In betaY16L ETF, the potentials of the flavin were slightly reduced, and steady state kinetic constants were modestly altered. Substitution of an alanine residue for betaTyr16 yields an ETF with potentials very similar to the wild type but with steady state kinetic properties similar to betaY16L ETF. It is unlikely that the beta methyl group of the alanine residue interacts with the flavin C(8) methyl. Neither substitution of betaTyr16 had a large effect on the fast phase of ETF reduction by medium chain acyl-CoA dehydrogenase.

Acyl-CoA Dehydrogenase↗
PubMed1999

Tissue factor is required for uterine hemostasis and maintenance of the placental labyrinth during gestation.

We employed a novel mouse line that expresses low levels of human tissue factor (TF) in the absence of murine TF to analyze the role of TF in gestation. Low-TF female mice had a 14-18% incidence of fatal postpartum uterine hemorrhage, suggesting that TF plays an important role in uterine hemostasis. Low-TF female mice mated with low-TF male mice had a 42% incidence of fatal midgestational hemorrhage (n = 41), whereas no fatal midgestational hemorrhages were observed in low-TF female mice mated with wild-type male mice (n = 43). Placentas of low-TF embryos from both low-TF and normal (+/-) TF females were abnormal and contained numerous maternal blood pools in the labyrinth. Placentas of TF null embryos surviving beyond embryonic day 10.5 exhibited similar defects. The mouse maternal-embryonic placental barrier consists of four cellular layers (layers I, II, and III and endothelial cells), where layer I lines the maternal lacunae. Comparison of TF-deficient placentas with control placentas by immunohistochemical and ultrastructural analyses revealed thinning of layer I and a reduction in the number of cellular contacts of layer I trophoblasts spanning the maternal blood space between adjacent trabeculae. These structural changes in low-TF and TF null placentas result in enlarged maternal lacunae, as determined by morphometric analysis, and placental hemorrhage, which leads to midgestational death of low-TF female mice. This study demonstrated that TF is required for uterine hemostasis and revealed an unexpected role of TF in the maintenance of the placental labyrinth.

Animals↗
PubMed1999

Pit-1 mediates cell-specific and cAMP-induced transcription of the tilapia GH gene.

Expression of the tilapia growth hormone (tiGH) gene is pituitary-specific and controlled by intracellular cAMP levels. DNaseI protection experiments allowed us to identify four Pit-1 binding sites in the tiGH - 465/ + 19 region. Deletion and mutagenesis analysis revealed that the - 131/+ 19 region, containing two Pit-1 sites, or four copies of the most proximal site tiGHF1 fused to the heterologous Tk promoter, confer high level expression in rat pituitary cells and direct transcription in non-pituitary cells only after expression of rat Pit-1. We show that a tilapia pituitary factor specifically binds to site tiGHF1 and obtained a partial cDNA sequence coding for tilapia Pit-1. The cAMP stimulation is mediated by the proximal (- 131/- 31) promoter region. It is Pit-1-dependent and requires the tiGHF1 site. In addition, four copies of this site confer cAMP inducibility to the Tk promoter in GC cells.

Amino Acid Sequence↗
PubMed1999

Size limitations in semicircular duct systems

The present article discusses mechanical requirements and limitations which are applicable to the construction of the system of semicircular ducts, especially to its size. The simplified case of a single, uniform duct system has been considered which can be described by a second order equation of motion. The principal functional quantities for this rotation-sensor are: (1) response speed; (2) sensitivity; and (3) regular flow. The response speed of a single, uniform semicircular duct is characterized by the short time constant (T2) which is dependent on the duct radius (r). Its estimated range is from 0.04 ms in the smallest to 140 ms in the largest known labyrinth. The sensitivity is characterized by the maximal endolymph displacement after a step stimulus (xmax). Its estimated range is from 0.0016 &mgr;m to 5.97 mm (6.56 decades!), assuming an input angular velocity of omega=1 rad s-1. The Reynolds number is a measure for an undisturbed laminar flow. Its estimated range varies from 7.38.10(-4)to 45.1 for omega=1 rad s-1. The above data follow from graphs in which, for a single uniform duct, circuit radius (R) is plotted against duct radius (r) for labyrinths of 233 species belonging to different vertebrate-groups. A relation R =38.9. r1.60was determined. The smallest labyrinth was found in a carp larva (Cyprinus), the largest in a whale shark (Rhincodon). Large whales possess labyrinths of average mammalian size. It is revealed that semicircular duct size is bound by requirements concerning regular flow and by a too low response speed for large labyrinths, and by a too low sensitivity for small labyrinths. Other important quantities are mechanical amplification factors which are a consequence of more complex vestibular constructions than a single uniform duct circuit. Allometric relationships are interpreted as compromises between the quantities mentioned. A hypothesis for the relatively large semicircular duct sizes of fishes, especially Elasmobranchii, compared with mammals and birds is presented. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Duplication of the POMC gene in the paddlefish (Polyodon spathula): analysis of gamma-MSH, ACTH, and beta-endorphin regions of ray-finned fish POMC.

The proopiomelanocortin (POMC) gene, which encodes the common precursor for MSH-related and beta-endorphin-related end products, appeared early in chordate evolution and features a variety of lineage-specific modifications. Key among these has been the apparent degeneration and subsequent deletion of the gamma-MSH region during the evolution of POMC in the ray-finned fish. A second area of increasing focus has been the role of gene duplication in the evolution of POMC in particular and the opioid/orphanin gene family in general. The cloning and phylogenetic analysis of two POMC cDNAs from the paddlefish (Polyodon spathula) is reported here and biochemical data on their processed end products are presented. Based on conceptual amino acid translations, the paddlefish cDNAs encode all functional domains and, in most cases, the flanking paired-basic amino acid cleavage sites characteristic of gnathostome POMCs (i.e., signal sequence, gamma-MSH-like region, ACTH (alpha-MSH and CLIP), gamma-LPH, beta-MSH, and beta-endorphin). Phylogenetic analysis of the paddlefish POMC sequences in the context of the duplicated POMCs of sturgeon and salmonids suggests that degeneration of the gamma-MSH core sequence and its amino-terminal proteolytic cleavage site was initiated prior to divergence of the sturgeon and paddlefish lineages over 150 mya. Finally, a comparison of the relative rates of evolutionary divergence between paralogously related POMC genes within chondrostean and salmonid lineages provides potential support for the hypothesis that some taxa (e.g., the Chondrosteii) represent relic species as a result of an exceptionally slow rate of evolutionary change.

Adrenocorticotropic Hormone↗
PubMed1999

APH-1, a POU homeobox gene expressed in the salt gland of the crustacean Artemia franciscana.

We characterized the first POU-homeoprotein in a crustacean (designated APH-1 for Artemia POU-Homeoprotein, EMBL Y15070). The amino acid sequence of the APH-1 POU-domain is identical, except for two residues, to that of the two class III POU proteins Cf1-a (Drosophila) and POU-M1 (Bombyx mori). Southern blot analysis suggests that crustaceans have only one class III POU gene. RT-PCR and whole-mount in situ hybridization show that APH-1 mRNA is present in larvae specifically in the salt gland, an organ which is involved in osmoregulation, and disappears in the adult.

Amino Acid Sequence↗
PubMed1999

The removal of the smear layer using the Quantec system. A study using the scanning electron microscope.

AIM: The aim of this study was to determine the ability of the Quantec Series 2000 rotary nickel-titanium endodontic system to remove dentinal debris and smear layer produced during canal preparation. METHODOLOGY: A first group (control) of 12 curved root canals was prepared using conventional manual instruments and the step-back technique. A second group of 12 curved root canals was instrumented using the complete Quantec sequence according to the manufacturer's instructions. In both groups, irrigation was performed using a 3% NaOCl solution. The canal walls were observed under a scanning electron microscope and the coronal, middle and apical thirds of each canal photographed at a magnification of 500. The views were divided into 10 subareas by overlaying a grid, and the absence or presence of a smear layer was rated and scored on three appearances using the scale described by Ciucchi et al. (1989). RESULTS: The scores were higher (i.e. less debris was present) in the middle third (P < 0.0001) and in the apical third (P < 0.0001) of canals prepared with the Quantec system when compared with those prepared with K-files. Nevertheless, in canals prepared with Quantec instruments, the scores were significantly higher in the coronal third compared with the apical third (P < 0.005). CONCLUSIONS: The Quantec rotary system produced cleaner canal walls than conventional manual instrumentation, particularly in the middle and apical thirds. This finding may imply that stresses applied to the cutting regions of Quantec instruments by accumulation and compression of the smear layer are minimized.

Dental High-Speed Technique↗
PubMed1999

Structure and functional analysis of a tilapia (Oreochromis mossambicus) growth hormone gene: activation and repression by pituitary transcription factor Pit-1.

A gene encoding the Tilapia mossambica (Oreochromis mossambicus) growth hormone (tiGH) was isolated and sequenced. The gene spans 5.6 kb, including 3.7 kb of 5' and 0.2 kb of 3' flanking sequences and a 1.7-kb transcription unit comprised of six exons and five introns. The gene and the 5' flanking region contain several potential binding sites for Pit-1, a key transcription activator of mammalian GH genes. One of these (-57/-42) is highly conserved in fish GH genes. It activates transcription in pituitary cells and binds Pit-1. Transfection of luciferase reporter plasmids containing either the -3602/+19 tiGH sequence or one of its 5' deletion mutants (-2863/, -1292/, and -463/+19) resulted in strong activity in Pit-1-producing rat pituitary GC cells. A dose-dependent activation of the tiGH promoter was achieved in nonpituitary fish EPC and monkey COS cells cotransfected with a rat Pit-1 expression vector, demonstrating the crucial role played by Pit-1 as an activator of the tiGH gene. Fusion of the tiGH promoter with the beta-galactosidase gene led to transient expression specifically in the nervous system of microinjected zebrafish embryos. The activity of the tiGH promoter in GC and EPC cells was strongly repressed by extending its 3' end from +19 to +40, a sequence in which a Pit-1-binding site was identified using gel retardation assays. Point mutations of the site that suppressed Pit-1 binding in vitro restored full tiGH promoter activity. Thus, a Pit-1-binding site located in the 5' untranslated region mediates Pit-1-dependent repression of the tiGH gene.

3' Untranslated Regions↗
PubMed1999

The mcp element from the Drosophila melanogaster bithorax complex mediates long-distance regulatory interactions.

In the studies reported here, we have examined the properties of the Mcp element from the Drosophila melanogaster bithorax complex (BX-C). We have found that sequences from the Mcp region of BX-C have properties characteristic of Polycomb response elements (PREs), and that they silence adjacent reporters by a mechanism that requires trans-interactions between two copies of the transgene. However, Mcp trans-regulatory interactions have several novel features. In contrast to classical transvection, homolog pairing does not seem to be required. Thus, trans-regulatory interactions can be observed not only between Mcp transgenes inserted at the same site, but also between Mcp transgenes inserted at distant sites on the same chromosomal arm, or even on different arms. Trans-regulation can even be observed between transgenes inserted on different chromosomes. A small 800-bp Mcp sequence is sufficient to mediate these long-distance trans-regulatory interactions. This small fragment has little silencing activity on its own and must be combined with other Polycomb-Group-responsive elements to function as a "pairing-sensitive" silencer. Finally, this pairing element can also mediate long-distance interactions between enhancers and promoters, activating mini-white expression.

Animals↗