Determination of serotypes of dengue viruses involved in sequential infections is important since, according to a theory of the pathogenesis of dengue haemorrhagic fever, a particular serotype may be a risk factor. It has been reported in Asia that at least the serotypes involved in the first infections could be serologically identified by the plaque reduction neutralization test (PRNT) because the highest PRNT titres after the second infections corresponded to the serotypes in the first infections. We re-examined the application of this theory of 'original antigenic sin' in Puerto Rico to evaluate its utility in serodiagnosis. Our results showed that it could not be applied reliably because of discrepant results.

Adolescent↗

PubMedDate not supplied

Validation of the VITEK2 and the Advance Expert System with a collection of Enterobacteriaceae harboring extended spectrum or inhibitor resistant beta-lactamases.

The susceptibility testing accuracy of the VITEK2 system and the ability of the Advance Expert System (AES) to provide interpretive readings were evaluated against 86 extended spectrum (ESBL) and 6 inhibitor-resistant-TEM (IRT) beta-lactamases producing Enterobacteriaceae clinical isolates. VITEK2 MICs of 12 beta-lactams were compared with those obtained by the standard NCCLS microdilution technique. The overall essential agreement ( +/- 1 log dilution) was 87.8%. Discrepancies were mainly observed with cefepime (30.3% of total number of discrepancies), ceftazidime (21.2%), and cefotaxime (15.1%). MIC discrepancies were slightly higher in CTX-M- (14.4%) than in TEM- (12.5%) or SHV- (11.9%) type ESBL producers and were rare in IRT producers (1.4%). Overall interpretive agreement was 92.5% and minor, major, and very major errors were 5.4%, 1.7%, and 2.1%, respectively. The AES was able to identify an ESBL phenotype in 85 out of 86 isolates (98.8%) and an IRT phenotype in all 6 isolates harboring these enzymes, thus reducing very major errors to 0.9%. The VITEK2 system, in conjunction with the AES software, is a reliable tool for detection of ESBL or IRT producing Enterobacteriaceae isolates.

Anti-Bacterial Agents↗

PubMedDate not supplied

Economic evaluations relating to diabetes: a descriptive review and their compliance with guidance.

From a search of the Health Economics Evaluations Database (HEED), 301 studies relating to diabetes-related interventions were identified. Of these, 223 studies contained some original data, i.e., were applied studies. Over the 1990s, the number of studies undertaken in this area appears to be increasing year on year, and more of the studies are applicable to the USA than to all other countries combined. Most studies are peer reviewed, the main type of analysis is cost-consequence, and the interventions most often assessed are pharmaceutical and care services. Both the public and the private sectors sponsor many of these studies. However, only a fraction of these studies appear to accord with guidance for good economic evaluation. For example, when the search criteria were tightened to capture only those studies that consider both outcomes and costs, 173 studies were identified. Narrowing the search criteria to capture only those studies that were based on randomized controlled trial (RCT) or modeling data-the methods recommended by the US Panel and the National Institute of Clinical Excellence (NICE)-reduced the sample to 56 studies. With specific focus on those studies that evaluated pharmaceuticals, only the modeling approach appeared to show any compliance at all with another key recommendation of the existing guidance on methods; that of using outcome measures that are applicable to a long-term time horizon. Though modeling does offer certain advantages over RCTs (for example, a larger range of comparators can be more readily incorporated, long-term outcome measures can be more easily and inexpensively estimated), modeling results have less internal validity. Also, modeling in itself relies on good RCT data. Therefore, the results of economic evaluations should be interpreted with care, irrespective of whether they are principally based on RCT or model-based methods.

Diabetes Mellitus, Type 2↗

PubMedDate not supplied

[Segmental analysis of the movement of the posterior mitral valve in mitral stenosis].

We have analyzed independently, both, early diastolic and end diastolic (A wave) movements of the posterior mitral leaflet in 302 cases of mitral stenosis with sinus rhythm, as well as in a control group of 100 subjects without mitral stenosis. Studied patients were separated into two groups: 275 that were not treated surgically, and 27 studied after mitral commisurotomy. We described 4 patterns of posterior mitral leaflet early diastolic movement, and 3 patterns of A wave motion. Only those patterns that showed anterior drift of the studied segment of the posterior mitral leaflet, were considered diagnostic of mitral stenosis. The sensitivity found was 49% for the anterior early diastolic movement; 89,5% for the anterior A wave, and 95,3% for both signs considered together. The specificity was 99% for anterior A wave, with a predictive value of 99,6%. When surgical and non surgical groups were compared, the absence of anterior drift in early diastole in the former group, showed to have statistical significance when the Chi square test was employed, while A wave pattern (anterior drift) did not show any difference between both groups. It is concluded that the most sensitive and specific sign for M-mode echocardiagraphic diagnosis of mitral stenosis in patients with sinus rhythm is the anterior drift of posterior mitral leaflet's A wave.

Diastole↗

PubMedDate not supplied

Serum erythropoietin in the diagnosis of polycythemia vera. A follow-up study.

BACKGROUND AND OBJECTIVE: It has been suggested that the determination of serum erythropoietin (sEpo) may be useful in distinguishing between polycythemia vera (PV), relative polycythemia and secondary polycythemia (SP), but no conclusive evidence has yet been provided for this. In the present work, we evaluated the role of sEpo in the differential diagnosis of polycythemia vera and its usefulness in the follow-up of PV patients. METHODS: sEpo was assessed in 190 patients with polycythemia of different etiologies. A follow-up study was carried out in some of these patients (27 with secondary polycythemia and 17 with polycythemia vera). RESULTS: sEpo levels were higher in SP than in PV and relative polycythemia. There were, however, differences with regard to the various etiologies of SP. Polycythemia related to congenital heart disorders showed the highest levels of sEpo of the SP. When a study was conducted, sEpo alone as a diagnostic parameter displayed an efficiency of more than 90% and the most discriminating value was 5 U/L. Using lower levels (below 2 U/L) and higher levels (above 12 U/L), it was possible to distinguish between SP and PV, although an important overlap was detected between these limits (approximately 50% of cases). The follow-up study showed that in half the patients with SP the levels of sEpo were at times < 12 U/L and at other times greater than this value. At least three determinations were necessary to detect an elevated reading. In PV after venesection there was an increase in sEpo in some cases, although most of the time there was no change. INTERPRETATION AND CONCLUSIONS: Using sEpo, it was possible to differentiate between PV and SP, despite an important overlap. A follow-up study demonstrated that the increase in sEpo was intermittent in SP and that in many of these cases more than one determination could be helpful.

Adult↗