Secular trends in pediatric antiretroviral treatment programs in rural and urban Zambia: a retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>Since 2003 pediatric antiretroviral treatment (ART) programs have scaled-up in sub-Saharan Africa and should be evaluated to assess progress and identify areas for improvement. We evaluated secular trends in the characteristics and treatment outcomes of children in three pediatric ART clinics in urban and rural areas in Zambia.</p> <p>Methods</p> <p>Routinely collected data were analyzed from three ART programs in rural (Macha and Mukinge) and urban (Lusaka) Zambia between program implementation and July 2008. Data were obtained from electronic medical record systems and medical record abstraction, and were categorized by year of program implementation. Characteristics of all HIV-infected and exposed children enrolled in the programs and all children initiating treatment were compared by year of implementation.</p> <p>Results</p> <p>Age decreased and immunologic characteristics improved in all groups over time in both urban and rural clinics, with greater improvement observed in the rural clinics. Among children both eligible and ineligible for ART at clinic enrollment, the majority started treatment within a year. A high proportion of children, particularly those ineligible for ART at clinic enrollment, were lost to follow-up prior to initiating ART. Among children initiating ART, clinical and immunologic outcomes after six months of treatment improved in both urban and rural clinics. In the urban clinics, mortality after six months of treatment declined with program duration, and in the rural clinics, the proportion of children defaulting by six months increased with program duration.</p> <p>Conclusions</p> <p>Treatment programs are showing signs of progress in the care of HIV-infected children, particularly in the rural clinics where scale-up increased rapidly over the first three years of program implementation. However, continued efforts to optimize care are needed as many children continue to enroll in ART programs at a late stage of disease and thus are not receiving the full benefits of treatment.</p

Dual spacecraft observations of lobe magnetic field perturbations before, during and after plasmoid release

This study examines a data set returned by IMP 8 and Geotail on January 29, 1995 during a substorm which resulted in the ejection of a plasmoid. The two spacecraft (s/c) were situated in the north lobe of the tail and both observed a traveling compression region (TCR). We show that in this instance dual s/c measurements can be used to model all three dimensions of the underlying plasmoid and to estimate its rate of expansion. For this event plasmoid dimensions of ΔX ∼18, ΔY ∼30, and ΔZ ∼10 Re are determined from the IMP 8 and Geotail observations. Furthermore, a factor of ∼2 increase in the amplitude of the TCR occurred in the 1.5 min it took to move from IMP 8 to Geotail. Modeled using conservation of magnetic flux, this increase in lobe compression implies that the underlying plasmoid was expanding at a rate of ∼140 km/s. Finally, a reconfiguration of the lobe magnetic field followed plasmoid ejection which moved magnetic flux tubes into the wake behind the plasmoid where they would become available to feed the reconnection region

Simultaneous resection of colorectal cancer and synchronous liver metastases: what determines the risk of unfavorable outcomes? An international multicenter retrospective cohort study

BACKGROUND: The use of a simultaneous resection (SIMR) in patients with synchronous colorectal liver metastases (sCRLM) has increased over the past decades. However, it remains unclear when a SIMR is beneficial and when it should be avoided. The aim of this retrospective cohort study was therefore to compare the outcomes of a SIMR for sCRLM in different settings, and to assess which factors are independently associated with unfavorable outcomes. METHODS: To perform this retrospective cohort study, patients with sCRLM undergoing SIMR (2004-2019) were extracted from an international multicenter database, and their outcomes were compared after stratification according to the type of liver and colorectal resection performed. Factors associated with unfavorable outcomes were identified through multivariable logistic regression. RESULTS: Overall, 766 patients were included, encompassing colorectal resections combined with a major liver resection (n=122), minor liver resection in the anterolateral (n=407), or posterosuperior segments ('Technically major', n=237). Minor and technically major resections, compared to major resections, were more often combined with a rectal resection (29.2 and 36.7 vs. 20.5%, respectively, both P=0.003) and performed fully laparoscopic (22.9 and 23.2 vs. 6.6%, respectively, both P = 0.003). Major and technically major resections, compared to minor resections, were more often associated with intraoperative transfusions (42.9 and 38.8 vs. 20%, respectively, both P = 0.003) and unfavorable incidents (9.6 and 9.8 vs. 3.3%, respectively, both P≤0.063). Major resections were associated, compared to minor and technically major resections, with a higher overall morbidity rate (64.8 vs. 50.4 and 49.4%, respectively, both P≤0.024) and a longer length of stay (12 vs. 10 days, both P≤0.042). American Society of Anesthesiologists grades ≥3 [adjusted odds ratio (aOR): 1.671, P=0.015] and undergoing a major liver resection (aOR: 1.788, P=0.047) were independently associated with an increased risk of severe morbidity, while undergoing a left-sided colectomy was associated with a decreased risk (aOR: 0.574, P=0.013). CONCLUSIONS: SIMR should primarily be reserved for sCRLM patients in whom a minor or technically major liver resection would suffice and those requiring a left-sided colectomy. These findings should be confirmed by randomized studies comparing SIMR with staged resections

Surveillance of women at high risk for hereditary ovarian cancer is inefficient

To determine the effectiveness of annual gynaecological screening (pelvic examination, transvaginal ultrasound, and CA-125), a prospective cohort study of women at high risk for hereditary ovarian cancer was conducted. Women were offered DNA analysis followed by either annual screening or prophylactic bilateral salpingo-oophorectomy (BSO). Study population consisted of 512 high-risk women (median follow-up 2.07 years, range 0–9.4 years): 265 women (52%) had a BRCA mutation. Persisting abnormalities indicated diagnostic surgery in 24 women resulting in one primary ovarian cancer FIGO stage IIIc was found. The effectiveness of screening was studied by calculating the probability of finding ovarian cancers in the BRCA-1 and BRCA-2 carrier group and comparing this to the identified number of ovarian cancers. The number of ovarian cancer patients found at surveillance was in accordance with the predicted number of ovarian cancers. A total number of 169 women underwent prophylactic BSO: one ovarian cancer stage IIb was found. In conclusion, the surveillance programme for hereditary ovarian cancer does identify patients with ovarian cancer but is very inefficient considering the high number of surveillance visits and the advanced stage of ovarian cancer in the identified patient. For prevention of advanced stage ovarian cancer, prophylactic BSO from age 35–40 years is a more efficient alternative

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Severe morbidity and mortality in untreated HIV-infected children in a paediatric care programme in Abidjan, Côte d'Ivoire, 2004-2009

<p>Abstract</p> <p>Background</p> <p>Clinical evolution of HIV-infected children who have not yet initiated antiretroviral treatment (ART) is poorly understood in Africa. We describe severe morbidity and mortality of untreated HIV-infected children.</p> <p>Methods</p> <p>All HIV-infected children enrolled from 2004-2009 in a prospective HIV programme in two health facilities in Abidjan, Côte d'Ivoire, were eligible from their time of inclusion. Risks of severe morbidity (the first clinical event leading to death or hospitalisation) and mortality were documented retrospectively and estimated using cumulative incidence functions. Associations with baseline characteristics were assessed by competing risk regression models between outcomes and antiretroviral initiation.</p> <p>Results</p> <p>405 children were included at a median age of 4.5 years; at baseline, 66.9% were receiving cotrimoxazole prophylaxis, and 27.7% met the 2006 WHO criteria for immunodeficiency by age. The risk of developing a severe morbid event was 14% (95%CI: 10.7 - 17.8) at 18 months; this risk was lower in children previously exposed to any prevention of mother-to-child-transmission (PMTCT) intervention (adjusted subdistribution hazard ratio [sHR]: 0.16, 95% CI: 0.04 - 0.71) versus those without known exposure. Cumulative mortality reached 5.5% (95%CI: 3.5 - 8.1) at 18 months. Mortality was associated with immunodeficiency (sHR: 6.02, 95% CI: 1.28-28.42).</p> <p>Conclusions</p> <p>Having benefited from early access to care minimizes the severe morbidity risk for children who acquire HIV. Despite the receipt of cotrimoxazole prophylaxis, the risk of severe morbidity and mortality remains high in untreated HIV-infected children. Such evidence adds arguments to promote earlier access to ART in HIV-infected children in Africa and improve care interventions in a context where treatment is still not available to all.</p

Initial Mutations Direct Alternative Pathways of Protein Evolution

Whether evolution is erratic due to random historical details, or is repeatedly directed along similar paths by certain constraints, remains unclear. Epistasis (i.e. non-additive interaction between mutations that affect fitness) is a mechanism that can contribute to both scenarios. Epistasis can constrain the type and order of selected mutations, but it can also make adaptive trajectories contingent upon the first random substitution. This effect is particularly strong under sign epistasis, when the sign of the fitness effects of a mutation depends on its genetic background. In the current study, we examine how epistatic interactions between mutations determine alternative evolutionary pathways, using in vitro evolution of the antibiotic resistance enzyme TEM-1 β-lactamase. First, we describe the diversity of adaptive pathways among replicate lines during evolution for resistance to a novel antibiotic (cefotaxime). Consistent with the prediction of epistatic constraints, most lines increased resistance by acquiring three mutations in a fixed order. However, a few lines deviated from this pattern. Next, to test whether negative interactions between alternative initial substitutions drive this divergence, alleles containing initial substitutions from the deviating lines were evolved under identical conditions. Indeed, these alternative initial substitutions consistently led to lower adaptive peaks, involving more and other substitutions than those observed in the common pathway. We found that a combination of decreased enzymatic activity and lower folding cooperativity underlies negative sign epistasis in the clash between key mutations in the common and deviating lines (Gly238Ser and Arg164Ser, respectively). Our results demonstrate that epistasis contributes to contingency in protein evolution by amplifying the selective consequences of random mutations

What Will It Take to Eliminate Pediatric HIV? Reaching WHO Target Rates of Mother-to-Child HIV Transmission in Zimbabwe: A Model-Based Analysis

Using a simulation model, Andrea Ciaranello and colleagues find that the latest WHO PMTCT (prevention of mother to child transmission of HIV) guidelines plus better access to PMTCT programs, better retention of women in care, and better adherence to drugs are needed to eliminate pediatric HIV in Zimbabwe