An exploration of patient perceptions of adherence to tuberculosis treatment in Tanzania.

In this study, we aimed to explore patient perceptions of adherence to tuberculosis (TB) treatment and construct a theoretical model of treatment adherence behavior. We conducted semistructured interviews with 11 adherent patients from Tanzania whom we recruited by purposive sampling. The interview data were analyzed by content analysis. We found that the patient's intention to adhere is the most important determinant of adherence behavior. This intention is preceded by the decision to seek biomedical health care, and based on knowledge and beliefs about TB treatment and the motivation to be cured. The intention to adhere helps patients to cope with perceived barriers to adherence, such as socioeconomic difficulties, and to create an adherence-enabling environment in which the presence of social support plays an important role. Our preliminary adherence behavior model should be validated in larger, nonadherent patient populations and evaluated for its applicability to the development of adherence-promoting strategies.

Categorisation of dental care provided in the Netherlands.

OBJECTIVE: To describe the dental care provided in the Netherlands and investigate to what extent variations can be explained in accordance with certain general characteristics of patients. METHOD: Besides the more usual classification of treatment into groups of dental procedures, in this study it is done using constructed categorisation of dental care based on characteristics such as 'preventive', 'curative', 'new', 'time-consuming', 'complicated' and 'lucrative' treatment. The data were collected from various groups of dentists. Two smaller groups of dentists-informants were asked to categorise dental procedures: 16 out of 55 (29%) and 57 out of 150 (38%). Finally this resulted in six type-scores for each procedure. From another larger group of dentists (n = 607) data were collected about the procedures they performed on a 25% random sample of their patients. Categorisations of dental care per patient were calculated by combining the data on the factual procedures performed with the six 'type-scores' for the procedures concerned. Furthermore, the financial returns dentists generated per patient were calculated from the care they provided. RESULTS: Multilevel analysis shows that considerable variation exists in the categorisations of dental care provided according to age, gender, insurance situation and income level of patients. In youths, for example, relatively more 'preventive' and less 'curative', 'complicated' and 'lucrative' treatment is done and 'older' adults receive relatively less 'preventive' and more 'curative', 'time-consuming' and 'complicated' treatment. CONCLUSIONS: By classifying the dental care provided in certain categories, a general view is obtained of the variations between patients in the care provided. The age of patients appears to be the most critical factor, but there are differences among dentists in the way the age of patients influences their conduct in the provision of dental care.

Do students have sufficient knowledge of clinical anatomy?

INTRODUCTION: Comparisons of anatomy knowledge levels of students from various curricula show either no differences or small differences to the detriment of innovative schools. To pass judgement on the general level of students' anatomy knowledge, we need an absolute standard. The purpose of this study was to compare students' levels of anatomy knowledge as measured by a case-based anatomy test with standards set by different groups of experts. METHODS: A modified Angoff procedure was used to establish an absolute standard against which the students' results could be evaluated. Four panels of 9 anatomists, 7 clinicians, 9 recent graduates and 9 Year 4 students, respectively, judged 107 items of an anatomy test. The students' results on these items were compared with the standards obtained by the panels. RESULTS: If the standard established by the panel of Year 4 students was used, 64% of the students would fail the test. The standards established by the anatomists, clinicians and recent graduates would yield failure rates of 42%, 58% and 26%, respectively. CONCLUSION: According to the panels' standards, many students did not know enough about anatomy. The high expectations that the Year 4 students appeared to have of their peers may contribute to students' uncertainty about their level of anatomy knowledge.

Patient orientation and professional orientation of Dutch dentists.

By providing dental health care, dentists dedicate themselves to the preservation and/or improvement of oral health in their patients. By adequately carrying out this care providers' role, dentists will gain recognition, esteem and respect from both patients and colleagues. This analysis aims to assess the patient and professional orientation of dentists and investigate which of their personal and practice characteristics can be regarded determining for these two aspects of their role as care providers. In the year 2000, data was collected via a written questionnaire sent to a random, stratified sample of 790 dentists, of whom 607 (77%) responded. Multivariate regression analysis shows that the preventive treatment concept, professional satisfaction and the number of hours per week that household tasks are performed are positive determinants for dentists' patient orientation. Also, the longer dentists are active in their profession, the more patient oriented they will be, and with more hours per week support from oral hygienists they are less patient oriented. As for professional orientation, dentists' preventive treatment concept and their professional satisfaction can also be considered positive determinants. Furthermore, dentists are more profession oriented when their partner works in the practice, with more hours per week support from oral hygienist(s) and with more collaboration contacts with other care providers. Compared to men, women are on average less profession oriented. Among Dutch dentists, there exist clear differences in the way they take on their role as care providers with regard to patient orientation and professional orientation.

The effect of combined arterial hemodynamics on saphenous venous endothelial nitric oxide production.

INTRODUCTION: Evidence exists that an ideal bypass conduit should have a functional endothelial cell surface combined with mechanical properties similar to those of native arteries. We hypothesized that the effect of combined arterial levels of pulsatile shear stress, flow, and cyclic strain would enhance saphenous venous endothelial cell nitric oxide (NO) production, and that variations in these "ideal" conditions could impair this function. We studied NO production as a measure of endothelial function in response to different hemodynamic conditions. METHODS: Human adult saphenous venous endothelial cells were cultured in 10-cm silicone tubes, similar in diameter (5 mm) and compliance (6%) to a medium-caliber peripheral artery (eg, popliteal). Tube cultures were exposed to arterial conditions: a combined pressure (120/80 mm/Hg; mean, 100 mm/Hg), flow (mean, 115 mL/min) and cyclic strain (2%), with a resultant pulsatile shear stress of 4.8 to 9.4 dyne/cm2 (mean, 7.1). Identical tube cultures were used to study variations in these conditions. Modifications of the system included a noncompliant system, a model with nonpulsatile flow, and a final group exposed to pulsatile pressure with no flow. NO levels were measured with a fluorometric nitrite assay of conditioned media collected at 0, 0.25, 0.5, 1, 2, and 4 hours. Experimental groups were compared with cells exposed to nonpulsatile, nonpressurized low flow (shear stress 0.1 dyne/cm2) and static cultures. RESULTS: All experimental groups had greater rates of NO production than cells under static conditions (P <.05). Cells exposed to ideal conditions produced the greatest levels of NO. Independent decreases in compliance, flow, and pulsatility resulted in significantly lower rates of NO production than those in the group with these conditions intact (vs noncompliant P <.05, vs nonflow P <.05, and vs nonpulsatile P <.05). CONCLUSIONS: Our results show that in the absence of physiologically normal pulsatility, cyclic strain, and volume flow, endothelial NO production does not reach the levels seen under ideal conditions. Pulsatile flow and compliance (producing flow with cyclic stretch) play a key role in NO production by vascular endothelium in a three-dimensional hemodynamically active model. This correlates biologically with clinical experience linking graft inflow and runoff and the mechanical properties of the conduit to long-term patency.

trans-acting inhibition of genomic RNA dimerization by Rous sarcoma virus matrix mutants.

The genomic RNA of retroviruses exists within the virion as a noncovalently linked dimer. Previously, we identified a mutant of the viral matrix (MA) protein of Rous sarcoma virus that disrupts viral RNA dimerization. This mutant, Myr1E, is modified at the N terminus of MA by the addition of 10 amino acids from the Src protein, resulting in the production of particles containing monomeric RNA. Dimerization is reestablished by a single amino acid substitution that abolishes myristylation (Myr1E-). To distinguish between cis and trans effects involving Myr1E, additional mutations were generated. In Myr1E.cc and Myr1E-.cc, different nucleotides were utilized to encode the same protein as Myr1E and Myr1E-, respectively. The alterations in RNA sequence did not change the properties of the viral mutants. Myr1E.ATG- was constructed so that translation began at the gag AUG, resulting in synthesis of the wild-type Gag protein but maintenance of the src RNA sequence. This mutant had normal infectivity and dimeric RNA, indicating that the src sequence did not prevent dimer formation. All of the src-containing RNA sequences formed dimers in vitro. Examination of MA-green fluorescent protein fusion proteins revealed that the wild-type and mutant MA proteins Myr1E.ATG-, Myr1E-, and Myr1E-.cc had distinctly different patterns of subcellular localization compared with Myr1E and Myr1E.cc MA proteins. This finding suggests that proper localization of the MA protein may be required for RNA dimer formation and infectivity. Taken together, these results provide compelling evidence that the genomic RNA dimerization defect is due to a trans-acting effect of the mutant MA proteins.

RNA dimerization defect in a Rous sarcoma virus matrix mutant.

The retrovirus matrix (MA) sequence of the Gag polyprotein has been shown to contain functions required for membrane targeting and binding during particle assembly and budding. Additional functions for MA have been proposed based on the existence of MA mutants in Rous sarcoma virus (RSV), murine leukemia virus, human immunodeficiency virus type 1, and human T-cell leukemia virus type 1 that lack infectivity even though they release particles of normal composition. Here we describe an RSV MA mutant with a surprising and previously unreported phenotype. In the mutant known as Myr1E, the small membrane-binding domain of the Src oncoprotein has been added as an N-terminal extension of Gag. While Myr1E is not infectious, full infectivity can be reestablished by a single amino acid substitution in the Src sequence (G2E), which eliminates the addition of myristic acid and the membrane-binding capacity of this foreign sequence. The presence of myristic acid at the N terminus of the Myr1E Gag protein does not explain its replication defect, because other myristylated derivatives of RSV Gag are fully infectious (e.g., Myr2 [C. R. Erdie and J. W. Wills, J. Virol. 64:5204-5208, 1990]). Biochemical analyses of Myr1E particles reveal that they contain wild-type levels of the Gag cleavage products, Env glycoproteins, and reverse transcriptase activity when measured on an exogenous template. Genomic RNA incorporation appears to be mildly reduced compared to the wild-type level. Unexpectedly, RNA isolated from Myr1E particles is monomeric when analyzed on nondenaturing Northern blots. Importantly, the insertional mutation does not lie within previously identified dimer linkage sites. In spite of the dimerization defect, the genomic RNA from Myr1E particles serves efficiently as a template for reverse transcription as measured by an endogenous reverse transcriptase assay. In marked contrast, after infection of avian cells, the products of reverse transcription are nearly undetectable. These findings might be explained either by the loss of a normal function of MA needed in the formation or stabilization of RNA dimers or by the interference in such events by the mutant MA molecules. It is possible that Myr1E viruses package a single copy of viral RNA.