Summary Dengue disease encompasses various clinical manifestations including dengue fever (DF) and dengue hemorrhagic fever (DHF). In this article, we aimed to systematically review and analyze the association between different blood groups and severity of dengue. We searched nine databases for eligible papers reporting prevalence, distribution, and frequency of blood group type among dengue patients. Network meta‐analysis using R software was used to analyze the data. Of a total of 63 reports screened, we included 10 studies with total sample size 1977 patients (1382 DF and 595 DHF). Blood group O was found to have the worst outcome with the highest risk of developing DF (P‐score = 0.01) followed by group B (P‐score = 0.34), group A (P‐score = 0.64), and group AB (P‐score = 1), respectively. Blood group O also had the worst outcome with highest risk of developing DHF (P‐score = 0.1) followed by group B (P‐score = 0.29), group A (P‐score = 0.61), and group AB (P‐score = 1), respectively. There was a significant increase (P‐value <.001) in the overall odds risk of dengue infection among patients with Rhesus‐positive blood groups [OR = 540.03; (95% CI = 151.48‐1925.18)]. However, there was no significant difference in the odds risk of DF when compared to DHF according to Rhesus status (P‐value = .954). This study identified the O blood group as a potential risk factor in predicting clinical severity in dengue patients which may be helpful in evaluating patients for their likely need for critical care.

Globally, the discipline of neurosurgery has evolved remarkably fast. Despite being one of the latest medical specialties, which appeared only around hundred years ago, it has witnessed innovations in the aspects of diagnostics methods, macro and micro surgical techniques, and treatment modalities. Unfortunately, this development is not evenly distributed between developed and developing countries. The same is the case with neurosurgical education and training, which developed from only traditional apprentice programs in the past to more structured, competencebased programs with various teaching methods being utilized, in recent times. A similar gap can be observed between developed and developing counties when it comes to neurosurgical education. Fortunately, most of the scholars working in this field do understand the coherent relationship between neurosurgical education and neurosurgical practice. In context to this understanding, a symposium was organized during the World Federation of Neurological Surgeons (WFNS) Special World Congress Beijing 2019. This symposium was the brain child of Prof. Yoko Kato-one of the eminent leaders in neurosurgery and an inspiration for female neurosurgeons. Invited speakers from different continents presented the stages of development of neurosurgical education in their respective countries. This paper summarizes the outcome of these presentations, with particular emphasis on and the challenges faced by developing countries in terms of neurosurgical education and strategies to cope with these challenges.

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Faecal contamination of groundwater from pit latrines is widely perceived as a major threat to the 22 safety of drinking water for several billion people in rural and peri-urban areas worldwide. On the 23 floodplains of the Ganges-Brahmaputra-Meghna delta in Bangladesh, we constructed latrines and 24 monitored piezometer nests monthly for two years. We detected faecal coliforms (FC) in 3.3 -25 23.3% of samples at four sites. We differentiate a near-field, characterised by high concentrations 26 and frequent, persistent and contiguous contamination in all directions, and a far-field characterised 27 by rare, impersistent, discontinuous low-level detections in variable directions. Far-field FC 28 concentrations at four sites exceeded 0 and 10 cfu/100ml in 2.4 -9.6% and 0.2 -2.3% of sampling 29 events respectively. The lesser contamination of in-situ groundwater compared to water at the point-30 M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPTof-collection from domestic wells, which itself is less contaminated than at the point-of-31 consumption, demonstrates the importance of recontamination in the well-pump system. We present 32 a conceptual model comprising four sub-pathways: the latrine-aquifer interface (near-field); 33 groundwater flowing from latrine to well (far-field); the well-pump system; and post-collection 34 handling and storage. Applying a hypothetical dose-response model suggests that 1 -2% of the 35 diarrhoeal disease burden from drinking water is derived from the aquifer, 29% from the well-pump 36 system, and 70% from post-collection handling. The important implications are (i) that leakage 37 from pit latrines is a minor contributor to faecal contamination of drinking water in alluvial-deltaic 38 terrains; (ii) fears of increased groundwater pollution should not constrain expanding latrine 39 coverage, and (iii) that more attention should be given to reducing contamination around the well-40 head. 41 42

Mammalian sperm chromatin is highly condensed, so isolating DNA from such chromatin can be a formidable task. The procedures that produce high quality DNA from somatic cells fail to yield quality sperm DNA. In this study we have modified the previously used guanidinium method to make it simple and efficient in isolating human sperm DNA. In our method, the lysis buffer contained guanidinium, sodium citrate, sarkosyl, proteinase K and mercaptoethanol. Proteinase K was not used in the original guanidinium method but was included in our protocol. CsCl centrifugation of the lysate, as described in the original procedure, was omitted. Instead, isopropyl alcohol was added directly to the lysis buffer to harvest the DNA. This modified guanidinium method generated high molecular weight DNA while the other two methods resulted in considerable DNA degradation. There was no difficulty in restriction enzyme digestion of DNA prepared by the modified method as revealed by Southern blot analysis. Since the modified guanidinium method is a simple one-step procedure which avoids homogenization, organic solvents, centrifugation and, more importantly, produces degradation-free DNA, it could be the method of choice when DNA from mature germ cells is needed.

The hypo-osmotic swelling test (HOST or HOS test) usually takes into consideration the total HOS response value with no emphasis either on the value of the response subtypes or the response evaluation time. This study investigated the time course of HOS responses and analysed their physiological relevance. Raw semen spermatozoa and Percoll washed spermatozoa were used in the experiment. The morphological changes in the sperm tail were monitored by incubating the spermatozoa in the hypo-osmotic solution for 16 different time periods. The HOS reactive spermatozoa and the type of HOS reaction (swelling subtypes) of the samples subjected to different duration of treatment were identified under a phase contrast microscope. Also the fate of individual spermatozoa in a hypo-osmotic environment were monitored for 30 min. In spermatozoa exposed to a hypo-osmotic solution, the motility lasted usually less than 2 min and motility characteristics were uniquely different from that of the spermatozoa under iso-osmotic conditions. The HOS response development was permanent but the motility loss due to hypo-osmotic shock was reversible up to 1 min of incubation. There was an indication of ordered transition among the HOS swelling subtypes apparently initiating with subtype b destined to c, d, e, f and g. Further, the subtypes a and g showed gradual decrease and increase, respectively, while subtype b showed abrupt initial increase and then gradual decrease. Transition from b to g could be direct or via one or more than one subtypes. Ultrastructure based analysis indicated that HOS response subtypes are the apparent reflection of the differences in the cytoskeletal assembly of the sperm tail and thus may be identifying different physiological variants in the sperm population. These results indicate that shorter incubation is essential to document the kinetics of various HOS responses but the conventional HOS test misses these important HOS features because of lengthy incubation. Since the time course of ordered transition of HOS responses will vary more than the total HOS response in semen of different aetiologies, the importance of HOS response subtypes and response evaluation time should be taken into consideration when applying HOS test.