51 research outputs found
Bivalent Vaccine Effectiveness Against Type-Specific HPV Positivity: Evidence for Cross-Protection Against Oncogenic Types Among Dutch STI Clinic Visitors.
Observational postmarketing studies are important to assess vaccine effectiveness (VE). We estimated VE from the bivalent human papillomavirus (HPV) vaccine against HPV positivity of vaccine and nonvaccine types in a high-risk population
Haemodynamic consequences of changing potassium concentrations in haemodialysis fluids
<p>Abstract</p> <p>Background</p> <p>A rapid decrease of serum potassium concentrations during haemodialysis produces a significant increase in blood pressure parameters at the end of the session, even if effects on intra-dialysis pressure are not seen. Paradoxically, in animal models potassium is a vasodilator and decreases myocardial contractility. The purpose of this trial is to study the precise haemodynamic consequences induced by acute changes in potassium concentration during haemodialysis.</p> <p>Methods</p> <p>In 24 patients, 288 dialysis sessions, using a randomised single blind crossover design, we compared six dialysate sequences with different potassium profiles. The dialysis sessions were divided into 3 tertiles, casually modulating potassium concentration in the dialysate between the value normally used K and the two cut-off points K+1 and K-1 mmol/l. Haemodynamics were evaluated in a non-invasive manner using a finger beat-to-beat monitor.</p> <p>Results</p> <p>Comparing K-1 and K+1, differences were found within the tertiles regarding systolic (+5.3, +6.6, +2.3 mmHg, p < 0.05, < 0.05, ns) and mean blood pressure (+4.3, +6.4, -0.5 mmHg, p < 0.01, < 0.01, ns), as well as peripheral resistance (+212, +253, -4 dyne.sec.cm<sup>-5</sup>, p < 0.05, < 0.05, ns). The stroke volume showed a non-statistically-significant inverse trend (-3.1, -5.2, -0.2 ml). 18 hypotension episodes were recorded during the course of the study. 72% with K-1, 11% with K and 17% with K+1 (p < 0.01 for comparison K-1 vs. K and K-1 vs. K+1).</p> <p>Conclusions</p> <p>A rapid decrease in the concentration of serum potassium during the initial stage of the dialysis-obtained by reducing the concentration of potassium in the dialysate-translated into a decrease of systolic and mean blood pressure mediated by a decrease in peripheral resistance. The risk of intra-dialysis hypotension inversely correlates to the potassium concentration in the dialysate.</p> <p>Trial Registration Number</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01224314">NCT01224314</a></p
Treatment of hepatic encephalopathy by on-line hemodiafiltration: a case series study
<p>Abstract</p> <p>Background</p> <p>It is thought that a good survival rate of patients with acute liver failure can be achieved by establishing an artificial liver support system that reliably compensates liver function until the liver regenerates or a patient undergoes transplantation. We introduced a new artificial liver support system, on-line hemodiafiltration, in patients with acute liver failure.</p> <p>Methods</p> <p>This case series study was conducted from May 2001 to October 2008 at the medical intensive care unit of a tertiary care academic medical center. Seventeen consecutive patients who admitted to our hospital presenting with acute liver failure were treated with artificial liver support including daily on-line hemodiafiltration and plasma exchange.</p> <p>Results</p> <p>After 4.9 ± 0.7 (mean ± SD) on-line hemodiafiltration sessions, 16 of 17 (94.1%) patients completely recovered from hepatic encephalopathy and maintained consciousness for 16.4 ± 3.4 (7-55) days until discontinuation of artificial liver support (a total of 14.4 ± 2.6 [6-47] on-line hemodiafiltration sessions). Significant correlation was observed between the degree of encephalopathy and number of sessions of on-line HDF required for recovery of consciousness. Of the 16 patients who recovered consciousness, 7 fully recovered and returned to society with no cognitive sequelae, 3 died of complications of acute liver failure except brain edema, and the remaining 6 were candidates for liver transplantation; 2 of them received living-related liver transplantation but 4 died without transplantation after discontinuation of therapy.</p> <p>Conclusions</p> <p>On-line hemodiafiltration was effective in patients with acute liver failure, and consciousness was maintained for the duration of artificial liver support, even in those in whom it was considered that hepatic function was completely abolished.</p
The Effect of Tuberculosis on Mortality in HIV Positive People: A Meta-Analysis
Tuberculosis is a leading cause of death in people living with HIV (PLWH). We conducted a meta analysis to assess the effect of tuberculosis on mortality in people living with HIV. Meta-analysis of cohort studies assessing the effect of tuberculosis on mortality in PLWH. To identify eligible studies we systematically searched electronic databases (until December 2008), performed manual searches of citations from relevant articles, and reviewed conference proceedings. Multivariate hazard ratios (HR) of mortality in PLWH with and without tuberculosis, estimated in individual cohort studies, were pooled using random effect weighting according to "Der Simonian Laird method" if the p-value of the heterogeneity test was <0.05. Fifteen cohort studies were systematically retrieved. Pooled overall analysis of these 15 studies estimating the effect of tuberculosis on mortality in PLWH showed a Hazard Ratio (HR) of 1.8 (95% confidence interval (CI): 1.4-2.3). Subanalysis of 8 studies in which the cohort was not exposed to highly active antiretroviral therapy (HAART) showed an HR of 2.6 (95% CI: 1.8-3.6). Subanalysis of 6 studies showed that tuberculosis did not show an effect on mortality in PLWH exposed to HAART: HR 1.1 (95% CI: 0.9-1.3). These results provide an indication of the magnitude of benefit to an individual that could have been expected if tuberculosis had been prevented. It emphasizes the need for additional studies assessing the effect of preventing tuberculosis or early diagnosis and treatment of tuberculosis in PLWH on reducing mortality. Furthermore, the results of the subgroup analyses in cohorts largely exposed to HAART provide additional support to WHO's revised guidelines, which include promoting the initiation of HAART for PLWH co-infected with tuberculosis. The causal effect of tuberculosis on mortality in PLWH exposed to HAART needs to be further evaluated once the results of more cohort studies become availabl
Estimating the burden of selected non-communicable diseases in Africa: a systematic review of the evidence
Background
The burden of non-communicable diseases (NCDs) is rapidly increasing globally, and
particularly in Africa, where the health focus, until recently, has been on infectious diseases. The
response to this growing burden of NCDs in Africa has been affected owing to a poor
understanding of the burden of NCDs, and the relative lack of data and low level of research on
NCDs in the continent. Recent estimates on the burden of NCDs in Africa have been mostly
derived from modelling based on data from other countries imputed into African countries, and
not usually based on data originating from Africa itself. In instances where few data were
available, estimates have been characterized by extrapolation and over-modelling of the scarce
data. It is therefore believed that underestimation of NCDs burden in many parts of Africa cannot
be unexpected. With a gradual increase in average life expectancy across Africa, the region now
experiencing the fastest rate of urbanization globally, and an increase adoption of unhealthy
lifestyles, the burden of NCDs is expected to rise. This thesis will, therefore, be focussing on
understanding the prevalence, and/or where there are available data, the incidence, of four major
NCDs in Africa, which have contributed highly to the burden of NCDs, not only in Africa, but
also globally.
Methods
I conducted a systematic search of the literature on three main databases (Medline, EMBASE and
Global Health) for epidemiological studies on NCDs conducted in Africa. I retained and
extracted data from original population-based (cohort or cross sectional), and/or health service
records (hospital or registry-based studies) on prevalence and/or incidence rates of four major
NCDs in Africa. These include: cardiovascular diseases (hypertension and stroke), diabetes,
major cancer types (cervical, breast, prostate, ovary, oesophagus, bladder, Kaposi, liver, stomach,
colorectal, lung and non-Hodgkin lymphoma), and chronic respiratory diseases (chronic
obstructive pulmonary disease (COPD) and asthma). From extracted crude prevalence and
incidence rates, a random effect meta-analysis was conducted and reported for each NCD. An
epidemiological model was applied on all extracted data points. The fitted curve explaining the
largest proportion of variance (best fit) from the model was further applied. The equation
generated from the fitted curve was used to determine the prevalence and cases of the specific
NCD in Africa at midpoints of the United Nations (UN) population 5-year age-group population
estimates for Africa.
Results
From the literature search, studies on hypertension had the highest publication output at 7680, 92
of which were selected, spreading across 31 African countries. Cancer had 9762 publications and
39 were selected across 20 countries; diabetes had 3701 publications and 48 were selected across
28 countries; stroke had 1227 publications and 19 were selected across 10 countries; asthma had
790 publications and 45 were selected across 24 countries; and COPD had the lowest output with
243 publications and 13 were selected across 8 countries. From studies reporting prevalence
rates, hypertension, with a total sample size of 197734, accounted for 130.2 million cases and a
prevalence of 25.9% (23.5, 34.0) in Africa in 2010. This is followed by asthma, with a sample
size of 187904, accounting for 58.2 million cases and a prevalence of 6.6% (2.4, 7.9); COPD,
with a sample size of 24747, accounting for 26.3 million cases and a prevalence of 13.4% (9.4,
22.1); diabetes, with a sample size of 102517, accounting for 24.5 million cases and a prevalence
of 4.0% (2.7, 6.4); and stroke, with a sample size of about 6.3 million, accounting for 1.94
million cases and a prevalence of 317.3 per 100000 population (314.0, 748.2). From studies
reporting incidence rates, stroke accounted for 496 thousand new cases in Africa in 2010, with a
prevalence of 81.3 per 100000 person years (13.2, 94.9). For the 12 cancer types reviewed, a total
of 775 thousand new cases were estimated in Africa in 2010 from registry-based data covering a
total population of about 33 million. Among women, cervical cancer and breast cancer had 129
thousand and 81 thousand new cases, with incidence rates of 28.2 (22.1, 34.3) and 17.7 (13.0,
22.4) per 100000 person years, respectively. Among men, prostate cancer and Kaposi sarcoma
closely follows with 75 thousand and 74 thousand new cases, with incidence rates of 14.5 (10.9,
18.0) and 14.3 (11.9, 16.7) per 100000 person years, respectively.
Conclusion
This study suggests the prevalence rates of the four major NCDs reviewed (cardiovascular
diseases (hypertension and stroke), diabetes, major cancer types, and chronic respiratory diseases
(COPD and asthma) in Africa are high relative to global estimates. Due to the lack of data on
many NCDs across the continent, there are still doubts on the true prevalence of these diseases
relative to the current African population. There is need for improvement in health information
system and overall data management, especially at country level in Africa. Governments of
African nations, international organizations, experts and other stakeholders need to invest more
on NCDs research, particularly mortality, risk factors, and health determinants to have
evidenced-based facts on the drivers of this epidemic in the continent, and prompt better,
effective and overall public health response to NCDs in Africa
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