The meaning and use of the cumulative rate of potential life lost. (9/48457)

BACKGROUND: The 'years of potential life lost' (YPLL) is a public health measure in widespread use. However, the index does not apply to the comparisons between different populations or across different time periods. It also has the limit of being cross-sectional in nature, quantifying current burden but not future impact on society. METHODS: A new years-lost index is proposed-the 'cumulative rate of potential life lost' (CRPLL). It is a simple combination of the 'cumulative rate' (CR) and the YPLL. Vital statistics in Taiwan are used for demonstration and comparison of the new index with existing health-status measures. RESULTS: The CRPLL serves the purpose of between-group comparison. It can also be considered a projection of future impact, under the assumption that the age-specific mortality rates in the current year prevail. For a rare cause of death, it can be interpreted as the expected years (days) of potential life lost during a subject's lifetime. CONCLUSIONS: The CRPLL has several desirable properties, rendering it a promising alternative for quantifying health status.  (+info)

A review of statistical methods for estimating the risk of vertical human immunodeficiency virus transmission. (10/48457)

BACKGROUND: Estimation of the risk of vertical transmission of human immunodeficiency virus (HIV) has been complicated by the lack of a reliable diagnostic test for paediatric HIV infection. METHODS: A literature search was conducted to identify all statistical methods that have been used to estimate HIV vertical transmission risk. Although the focus of this article is the analysis of birth cohort studies, ad hoc studies are also reviewed. CONCLUSIONS: The standard method for estimating HIV vertical transmission risk is biased and inefficient. Various alternative analytical approaches have been proposed but all involve simplifying assumptions and some are difficult to implement. However, early diagnosis/exclusion of infection is now possible because of improvements in polymerase chain reaction technology and complex estimation methods should no longer be required. The best way to analyse studies conducted in breastfeeding populations is still unclear and deserves attention in view of the many intervention studies being planned or conducted in developing countries.  (+info)

Cluster survey evaluation of coverage and risk factors for failure to be immunized during the 1995 National Immunization Days in Egypt. (11/48457)

BACKGROUND: In 1995, Egypt continued to experience endemic wild poliovirus transmission despite achieving high routine immunization coverage with at least three doses of oral poliovirus vaccine (OPV3) and implementing National Immunization Days (NIDs) annually for several years. METHODS: Parents of 4188 children in 3216 households throughout Egypt were surveyed after the second round of the 1995 NIDs. RESULTS: Nationwide, 74% of children are estimated to have received both NID doses, 17% one NID dose, and 9% neither NID dose. Previously unimmunized (47%) or partially immunized (64%) children were less likely to receive two NID doses of OPV than were fully immunized children (76%) (P < 0.001). Other risk factors nationwide for failure to receive NID OPV included distance from residence to nearest NID site >10 minute walk (P < 0.001), not being informed about the NID at least one day in advance (P < 0.001), and residing in a household which does not watch television (P < 0.001). Based on these findings, subsequent NIDs in Egypt were modified to improve coverage, which has resulted in a marked decrease in the incidence of paralytic poliomyelitis in Egypt. CONCLUSIONS: In selected situations, surveys can provide important information that is useful for planning future NIDs.  (+info)

Identification and characterization of a novel Ibe10 binding protein that contributes to Escherichia coli invasion of brain microvascular endothelial cells. (12/48457)

The molecular basis of Escherichia coli traversal of the blood-brain barrier in the development of E. coli meningitis is not well understood. We have previously shown that a novel Ibe10 protein found in cerebrospinal fluid isolates of E. coli is necessary for invasion of the brain microvascular endothelial cells (BMEC) that constitute the blood-brain barrier both in vitro and in a newborn rat model of hematogenous meningitis. Here we identified a novel Ibe10 binding molecule/receptor (Ibe10R) on both bovine BMEC (HBMEC) and human BMEC (HBMEC) that is responsible for invasion by E. coli. Ibe10R, an approximately 55-kDa protein, was purified from BBMEC by Ibe10-Ni-Sepharose affinity chromatography. Bovine Ibe10R, as well as polyclonal antibodies to Ibe10R, blocked E. coli invasion of BBMEC very effectively. The N-terminal amino acid sequence of Ibe10R showed 75% homology to serum albumin. However, the amino acid sequence of an Ibe10R fragment generated by limited enzymatic digestion did not reveal homology to any other proteins, suggesting that Ibe10R represents a novel albumin-like protein. Immunocytochemical analysis of BBMEC using anti-Ibe10R antibody suggested that only a subset of cultured BBMEC express Ibe10R on their surface. Enrichment of Ibe10R-positive BBMEC by fluorescence-activated cell sorting with anti-Ibe10R antibody resulted in enhanced invasion by E. coli. The anti-Ibe10R antibody raised against bovine Ibe10R also blocked E. coli invasion of HBMEC very effectively. Interestingly, anti-Ibe10R antibody affinity chromatography of HBMEC membrane proteins revealed a smaller protein with an approximate molecular mass of 45 kDa. These results suggest that the Ibe10 of E. coli interacts with a novel BMEC surface protein, Ibe10R, for invasion of both BBMEC and HBMEC.  (+info)

Obstetric and neonatal outcome following chronic hypertension in pregnancy among different ethnic groups. (13/48457)

We retrospectively studied pre-eclampsia rate and obstetric outcome in a cohort of 436 pregnancies amongst 318 women of different ethnic backgrounds attending an antenatal hypertension clinic from 1980-1997, identifying 152 women (213 pregnancies) with chronic essential hypertension. The ethnic breakdown was: White, 64 (30.0%) pregnancies in 48 (31.5%) women; Black/Afro-Caribbean, 79 (37.1%) pregnancies in 56 (36.8%) women; and Indo-Asians, 70 (32.3%) pregnancies in 48 (31.6%) women. The prevalences of pre-eclampsia in White, Black and Indo-Asian women were 17.2%, 12.7% and 18.6%, respectively (p = 0.58). Pregnancies of Indo-Asian women were of shorter gestation, and babies in this group also had lower birth weight and ponderal index compared to those of White and Black women (all p < 0.05). The proportions of overall perinatal mortality were 1.6% for Whites (1/64), 3.8% for Blacks (3/79) and 10.0% for Indo-Asians (7/70), suggesting increased risk in the Indo-Asian group. Indo-Asian women with chronic essential hypertension need careful antenatal care and observation during pregnancy.  (+info)

A new alkali-resistant hemoglobin alpha2J Oxford gammaF2 in a Sicilian baby girl with homozygous beta0 thalassemia. (14/48457)

A 10-mo-old baby girl with homozygous beta0 thalassemia and alphaJOxford, presenting the clinical picture of homozygous beta thalassemia is described. Hemoglobin electrophoresis showed three bands: the first two with the mobilities of hemoglobin Hb A2 (1%) and Hb F (69%), respectively, the third migrating a little faster than Hb A (30%). About 30% of her alpha chains were J Oxford which, bound to her gamma chains, produced a new alkali-resistant hemoglobin, alpha2 J Oxford gamma F2, which has not been described previously. Hemoglobin synthesis in vitro showed the absence of beta chain synthesis and an alpha/non-alpha ratio of 2. The patient's father was heterozygous for both the Hb J Oxford and beta0 thalassemia genes, the mother a carrier of beta0 thalassemia; four other relatives were carriers of Hb J Oxford, and one was a carrier of beta thalassemia.  (+info)

Validation of the Rockall risk scoring system in upper gastrointestinal bleeding. (15/48457)

BACKGROUND: Several scoring systems have been developed to predict the risk of rebleeding or death in patients with upper gastrointestinal bleeding (UGIB). These risk scoring systems have not been validated in a new patient population outside the clinical context of the original study. AIMS: To assess internal and external validity of a simple risk scoring system recently developed by Rockall and coworkers. METHODS: Calibration and discrimination were assessed as measures of validity of the scoring system. Internal validity was assessed using an independent, but similar patient sample studied by Rockall and coworkers, after developing the scoring system (Rockall's validation sample). External validity was assessed using patients admitted to several hospitals in Amsterdam (Vreeburg's validation sample). Calibration was evaluated by a chi2 goodness of fit test, and discrimination was evaluated by calculating the area under the receiver operating characteristic (ROC) curve. RESULTS: Calibration indicated a poor fit in both validation samples for the prediction of rebleeding (p<0.0001, Vreeburg; p=0.007, Rockall), but a better fit for the prediction of mortality in both validation samples (p=0.2, Vreeburg; p=0.3, Rockall). The areas under the ROC curves were rather low in both validation samples for the prediction of rebleeding (0.61, Vreeburg; 0.70, Rockall), but higher for the prediction of mortality (0.73, Vreeburg; 0.81, Rockall). CONCLUSIONS: The risk scoring system developed by Rockall and coworkers is a clinically useful scoring system for stratifying patients with acute UGIB into high and low risk categories for mortality. For the prediction of rebleeding, however, the performance of this scoring system was unsatisfactory.  (+info)

Evidence of improving survival of patients with rectal cancer in france: a population based study. (16/48457)

BACKGROUND: Over the past 20 years there have been many changes in the management of rectal cancer. Their impact on the overall population is not well known. AIMS: To determine trends in management and prognosis of rectal cancer in two French regions. SUBJECTS: 1978 patients with a rectal carcinoma diagnosed between 1978 and 1993. METHODS: Time trends in treatment, stage at diagnosis, operative mortality, and survival were studied on a four year basis. A non-conditional logistic regression was performed to obtain an odds ratio for each period adjusted for the other variables. To estimate the independent effect of the period a multivariate relative survival analysis was performed. RESULTS: Over the 16 year period resection rates increased from 66.0% to 80.1%; the increase was particularly noticeable for sphincter saving procedures (+30.6% per four years, p=0.03). The percentage of patients receiving adjuvant radiotherapy increased from 24.0% to 40.0% (p=0.02). The proportion of patients with Dukes' type A cancer increased from 17. 7% to 30.6% with a corresponding decrease in those with more advanced disease. Operative mortality decreased by 31.1% per four years (p=0.03). All these improvements have resulted in a dramatic increase in relative survival (from 35.4% for the 1978-1981 period to 57.0% for the 1985-1989 period). CONCLUSIONS: Substantial advances in the management of rectal cancer have been achieved, but there is evidence that further improvements can be made in order to increase survival.  (+info)