Strong larvicidal potential of Artemisia annua leaf extract against malaria (Anopheles stephensi Liston) and dengue (Aedes aegypti L.) vectors and bioassay-driven isolation of the marker compounds

Malaria and dengue are the two most important vector-borne human diseases caused by mosquito vectors Anopheles stephensi and Aedes aegypti, respectively. Of the various strategies adopted for eliminating these diseases, controlling of vectors through herbs has been reckoned as one of the important measures for preventing their resurgence. Artemisia annua leaf chloroform extract when tried against larvae of A. stephensi and A. aegypti has shown a strong larvicidal activity against both of these vectors, their respective LC50 and LC90 values being 0.84 and 4.91 ppm for A. stephensi and 0.67 and 5.84 ppm for A. aegypti. The crude extract when separated through column chromatography using petroleum ether-ethyl acetate gradient (0–100 %) yielded 76 fractions which were pooled into three different active fractions A, B and C on the basis of same or nearly similar R _f values. The aforesaid pooled fractions when assayed against the larvae of A. stephensi too reported a strong larvicidal activity. The respective marker compound purified from the individual fractions A, B and C, were Artemisinin, Arteannuin B and Artemisinic acid, as confirmed and characterized through FT-IR and NMR. This is our first report of strong mortality of A. annua leaf chloroform extract against vectors of two deadly diseases. This technology can be scaled up for commercial exploitation.     

PICC-associated Bloodstream Infections: Prevalence,Patterns, and Predictors

Background

Growing use of peripherally inserted central catheters (PICCs) has led to recognition of the risk of PICC-associated bloodstream infection. We sought to identify rates, patterns, and patient, provider, and device characteristics associated with this adverse outcome.

Methods

A retrospective cohort of consecutive adults who underwent PICC placement from June 2009 to July 2012 was assembled. Using multivariable logistic and Cox-proportional hazards regression models, covariates specified a priori were analyzed for their association with PICC-associated bloodstream infection. Odds ratios (OR) and hazard ratios (HR) with corresponding 95% confidence intervals (CI) were used to express the association between each predictor and the outcome of interest.

Results

During the study period, 966 PICCs were inserted in 747 unique patients for a total of 26,887 catheter days. Indications for PICC insertion included: long-term antibiotic administration (52%, n = 503), venous access (21%, n = 201), total parenteral nutrition (16%, n = 155), and chemotherapy (11%, n = 107). On bivariate analysis, intensive care unit (ICU) status (OR 3.23; 95% CI, 1.84-5.65), mechanical ventilation (OR 4.39; 95% CI, 2.46-7.82), length of stay (hospital, OR 1.04; 95% CI, 1.02-1.06 and ICU, OR 1.03; 95% CI, 1.02-1.04), PowerPICCs (C. R. Bard, Inc., Murray Hill, NJ; OR 2.58; 95% CI, 1.41-4.73), and devices placed by interventional radiology (OR 2.57; 95% CI, 1.41-4.68) were associated with PICC-bloodstream infection. Catheter lumens were strongly associated with this event (double lumen, OR 5.21; 95% CI, 2.46-11.04, and triple lumen, OR 10.84; 95% CI, 4.38-26.82). On multivariable analysis, only hospital length of stay, ICU status, and number of PICC lumens remained significantly associated with PICC bloodstream infection. Notably, the HR for PICC lumens increased substantially, suggesting earlier time to infection among patients with multi-lumen PICCs (HR 4.08; 95% CI, 1.51-11.02 and HR 8.52; 95% CI, 2.55-28.49 for double- and triple-lumen devices, respectively).

Conclusions

PICC-associated bloodstream infection is most associated with hospital length of stay, ICU status, and number of device lumens. Policy and procedural oversights targeting these factors may be necessary to reduce the risk of this adverse outcome.     

Phosphorylation of the insulin receptor by AMP-activated protein kinase (AMPK) promotes ligand-independent activation of the insulin signalling pathway in rodent muscle

Aims/hypothesis  

Muscle may experience hypoglycaemia during ischaemia or insulin infusion. During severe hypoglycaemia energy production is blocked, and an increase of AMP:ATP activates the energy sensor and putative insulin-sensitiser AMP-activated protein kinase (AMPK). AMPK promotes energy conservation and survival by shutting down anabolism and activating catabolic pathways. We investigated the molecular mechanism of a unique glucose stress defence pathway involving AMPK-dependent, insulin-independent activation of the insulin signalling pathway.     

Gastrointestinal mucormycosis—four cases with different risk factors, involving different anatomical sites

Mucormycosis of the gastrointestinal tract is a rare infection that usually occurs in patients who are immunocompromised and carries a high mortality. We report four cases of gastrointestinal mucormycosis seen over a one year period with different presentations, risk factors and different anatomical sites of involvement. A preoperative diagnosis was made only in one patient. All underwent surgery, three survived and one died postoperatively from multiorgan failure.     

Proposed guidelines for the management of nodding syndrome

Nodding Syndrome is a poorly understood neurologic disorder of unknown aetiology that affects children and adolescents in Africa. Recent studies have suggested that the head nods are due to atonic seizures and Nodding Syndrome may be classified as probably symptomatic generalised epilepsy. As part of the Ugandan Ministry of Health clinical management response, a multidisciplinary team developed a manual to guide the training of health workers with knowledge and skills to manage the patients. In the absence of a known cause, it was decided to offer symptomatic care. The objective is to relieve symptoms, offer primary and secondary prevention for disability and rehabilitation to improve function. Initial management focuses on the most urgent needs of the patient and the immediate family until ‘stability’ is achieved. The most important needs were considered as seizure control, management of behavioural and psychiatric difficulties, nursing care, nutritional and subsequently, physical and cognitive rehabilitation. This paper summarises the processes by which the proposed guidelines were developed and provides an outline of the specific treatments currently being provided for the patients.     

Comparison of periodontal open flap debridement versus closed debridement with Er,Cr:YSGG laser

Background

Traditional periodontal open flap debridement (OFD) results in reduced pocket depth (PD), clinical attachment loss (CAL), gingival recession (GR) and postoperative pain and discomfort. The quest to overcome these shortcomings has led to research into Er,Cr:YSGG laser assisted pocket therapy (ELAPT). This study was designed to compare the clinical outcomes of ELAPT versus OFD.

Methods

Fifteen patients with a PD of ≥5 mm and ≤8 mm at two sites were selected. Test sites (Group 1) were treated by ELAPT and the control (Group 2) by OFD. Clinical parameters were recorded at baseline, 3 and 6 months and included Plaque Index (PI), Gingival Index (GI), modified Sulcular Bleeding Index (mSBI), PD, CAL and GR.

Results

Both treatments produced a reduction in PI, GI, mSBI and PD, an increase in GR, and a gain in CAL at 3 and 6 months. The mean gain of CAL in Group 1 at 3 and 6 months (1.60 ± 0.78 and 1.80 ± 0.63) was similar (p > 0.05) to the value of Group 2 (1.93 ± 0.88 and 2.00 ± 0.54). GR increased significantly (p < 0.05) only in Group 2 at 3 and 6 months (1.80 ± 0.56 and 1.87 ± 0.64) compared to Group 1 (0.50 ± 0.68 and 0.60 ± 0.74).

Conclusions

ELAPT compared with OFD results in similar CAL gains with less GR and significant reductions in PD, GI and mSBI, and may be considered as an alternative to surgical therapy.