Microvesicles from malaria-infected red blood cells activate natural killer cells via MDA5 pathway.

Natural killer (NK) cells provide the first line of defense against malaria parasite infection. However, the molecular mechanisms through which NK cells are activated by parasites are largely unknown, so is the molecular basis underlying the variation in NK cell responses to malaria infection in the human population. Here, we compared transcriptional profiles of responding and non-responding NK cells following exposure to Plasmodium-infected red blood cells (iRBCs) and identified MDA5, a RIG-I-like receptor involved in sensing cytosolic RNAs, to be differentially expressed. Knockout of MDA5 in responding human NK cells by CRISPR/cas9 abolished NK cell activation, IFN-γ secretion, lysis of iRBCs. Similarly, inhibition of TBK1/IKKε, an effector molecule downstream of MDA5, also inhibited activation of responding NK cells. Conversely, activation of MDA5 by liposome-packaged poly I:C restored non-responding NK cells to lyse iRBCs. We further show that microvesicles containing large parasite RNAs from iRBCs activated NK cells by fusing with NK cells. These findings suggest that NK cells are activated through the MDA5 pathway by parasite RNAs that are delivered to the cytoplasm of NK cells by microvesicles from iRBCs. The difference in MDA5 expression between responding and non-responding NK cells following exposure to iRBCs likely contributes to the variation in NK cell responses to malaria infection in the human population.

Association of rotavirus strains and severity of gastroenteritis in Indian children.

Rotavirus is the leading cause of severe and dehydrating diarrhea in children aged under 5 years. We undertook this hospital-based surveillance study to examine the possible relationship between the severity of diarrhea and the various G-group rotaviruses circulating in India. Stool samples (n = 2,051) were systematically collected from 4,711 children aged <5 years admitted with severe acute gastroenteritis to 12 medical school centers from April 2011 to July 2012. Rotavirus testing was undertaken using a commercially available enzyme immunoassay kit for the rotavirus VP6 antigen (Premier Rotaclone Qualitative ELISA). Rotavirus positive samples were genotyped for VP7 and VP4 antigens by reverse-transcription polymerase chain reaction at a central laboratory. Of the stool samples tested for rotavirus antigen, 541 (26.4%) were positive for VP6 antigen. Single serotype infections from 377 stool samples were compared in terms of gastroenteritis severity. Among those with G1 rotavirus infection, very severe diarrhea (Vesikari score ≥ 16) was reported in 59 (33.9%) children, severe diarrhea (Vesikari score 11-15) in 104 (59.8%), moderate (Vesikari score 6-10) and mild diarrhea (Vesikari score 0-5) in 11 (6.3%). Among those with G2 infection, very severe diarrhea was reported in 26 (27.4%) children, severe diarrhea in 46 (48.4%), and moderate and mild diarrhea in 23 (24.2 %). Among those with G9 infection, very severe diarrhea was reported in 47 (54.5%) children, severe diarrhea in 29 (33.6%), and moderate and mild diarrhea in 10 (11.9%). Among those with G12 infection, very severe diarrhea was reported in 9 (40.9%) children and severe diarrhea in 13 (59.1%). The results of this study indicate some association between rotavirus serotypes and severity of gastroenteritis.

Isotonic intravenous maintenance fluid reduces hospital acquired hyponatremia in young children with central nervous system infections.

OBJECTIVE: To find the appropriate type of intravenous fluid (isotonic vs. hypotonic saline in 5 % dextrose) for empiric maintenance fluid therapy in children with central nervous system (CNS) infections that reduces the incidence of hospital acquired hyponatremia. METHODS: This blinded randomized controlled trial included hospitalized children aged 3 mo to 5 y with suspected CNS infections requiring intravenous maintenance fluid for at least 24 h. The subjects were randomized to receive 0.9 % saline (Group-A), 0.45 % saline (Group-B) and 0.18 % saline (Group-C) at standard maintenance rate. The outcome measures were proportion of patients developing hyponatremia (serum sodium < 135 mmol/L) after 24 h and serum sodium values at 6, 12, 18, 24 h of receiving maintenance fluids. RESULTS: Of the 92 patients enrolled, 31, 30 and 31 patients were randomized to Group A, B and C, respectively. Majority (60.7 %) of the patients in Group-C developed hyponatremia compared with 7.1 % of the children in Group-A and 46.1 % in Group-B. During first 24 h of fluid administration successive fall in the serum sodium values was observed in patients receiving hypotonic fluids. The risk of developing hyponatremia was nearly 6½ (95 % confidence interval (CI) 1.6-26) to 8.5 (95 % CI 2.16-33.39) times more in patients who received hypotonic saline compared to those who received isotonic saline. CONCLUSIONS: Administration of 0.9 % saline in 5 % dextrose as intravenous maintenance fluid in children with CNS infection leads to significantly less incidence of hyponatremia when compared to that with hypotonic fluids.

Role of zinc in severe pneumonia: a randomized double bind placebo controlled study.

BACKGROUND: Pneumonia is a leading cause of morbidity and mortality in children. OBJECTIVE: The aim of study was to evaluate the efficacy of Zinc supplementation in treatment of severe pneumonia in hospitalized children. DESIGN/METHODS: A double blind randomized, placebo- controlled clinical trial conducted at a tertiary care centre of a teaching hospital. Children with diagnosis of severe pneumonia were randomly assigned to receive supplementation with either elemental zinc or placebo by mouth at the time of enrollment. From day 2, they received 10 mg of their assigned treatment by mouth twice a day for 7 days along with standard antimicrobial therapy. RESULTS: The baseline characteristics like age, sex, weight, weight Z score, height, height Z score, weight for height Z score and hemoglobin were comparable in both study groups. The respiratory rate, chest indrawing, cyanosis, stridor, nasal flaring, wheeze and fever in both groups recorded at enrollment and parameters did not differ significantly between the two groups. The outcome measures like time taken for resolution of severe pneumonia, pneumonia, duration of hospital stay, nil per oral, intravenous fluid, oxygen use, treatment requiring 2nd line of drug and 3rd line drug were evaluated and found to be same. CONCLUSION: The present study did not show a statistically significant reduction in duration of severe pneumonia, or reduction in hospital stay for children given daily zinc supplementation along with standard antimicrobial therapy. Therefore, zinc supplementation given during the acute episode does not help in short term clinical recovery from severe pneumonia.

Home-based newborn care how effective and feasible.

Neonatal mortality in developing countries is one of the most important problems that need immediate attention in order to achieve Millennium Development Goals. About 4 million newborns die in the world every year, 90% of them in the developing world. Most of these deaths are preventable by simple interventions in the community. However, in most of the target countries, the implementation of essential newborn care has been very poor. The home based or community care packages include maternal care, essential newborn care, improving the behavior change communication of the community, resuscitation of newborn babies at the time of home delivery, and management of sick newborns with antibiotics at home. Studies have reported one-third to two-third reduction of mortality among newborns after home based care interventions. However, when translated into scaling up of home based newborn care in the worst affected districts of the country, the results are not very rewarding. Identification of limiting factors and effective up scaling of the home-based packages will prove to be of enormous benefit in reducing neonatal mortality.

Kimura's disease: an unusual glandular involvement with blood and tissue eosinophilia.

Kimura's disease is a rare cause of a progressive neck swelling associated with blood and tissue eosinophilia. Though it is a benign disease, however, its unrelating course and unpredictable response to the therapeutic interventions, poses a great challenge to the treating physician, the patients and the caregiver. Here is one such case of Kimura's disease.

A comparison of immunogenicity and safety of indigenously developed liquid (DTwPHB-Hib) pentavalent combination vaccine (Shan 5) with Easyfive (liq) and TritanrixHB + Hiberix (lyo) in Indian infants administered according to the EPI schedule.

The study was planned to assess and compare the immune response and safety of an indigenous DTPwHB-Hib pentavalent liquid combination vaccine (Shan 5) with Easyfive and TritanrixHB+ Hiberix, the two available pentavalent combination vaccines. Four hundred infants were randomized to receive three doses of either Shan 5 or one of the two comparators. Antibody analysis was performed prior to and four to six weeks post third vaccine dose. Solicited local and systemic events upto three days and unsolicited adverse events in the 30 days follow up period after each dose were recorded. A total of 365 subjects completed the study. Four to six weeks after third dose, 98.32% of the subjects in Shan 5 group had seroprotective Anti PRP-T IgG antibody concentrations (> or =0.15 microg/mL) as compared to 100% and 98.94% subjects in TritanrixHB + Hiberix and Easyfive groups respectively. Seroprotective levels for Anti-HBs (> or =10 mIU/mL) were observed in 97.77%, 97.83% and 98.94% subjects in Shan 5, TritanrixHB + Hiberix and Easyfive groups respectively. Comparable immune responses were observed for the three other components (D, T and P) in all the groups. Four Serious Adverse Events (SAEs) were reported (three with Shan 5 and one with Easyfive), all unrelated to the respective vaccines. Most commonly reported adverse events in all the groups were pain at injection site, mild fever (<103 degrees F) and minor swelling at injection site. The study proved that Shan 5 was safe and immunogenic compared to the two other licensed vaccines.

Safety and immunogenicity of an indigenously developed Haemophilus influenzae type b conjugate vaccine through various phases of clinical trials.

In view of the need for a cost effective Haemophilus influenzae type b (Hib) conjugate vaccine, a lyophilized vaccine as capsular polysaccharide (PRP) conjugated to tetanus toxoid (Sii HibPRO) was indigenously developed by Serum Institute of India Ltd., Pune (SIIL). From 2004-07, this new vaccine underwent a series of clinical studies before its licensure by National Regulatory Authority (NRA). This paper discusses the results obtained during the clinical development of this vaccine. On finding the vaccine to be safe in animal toxicity studies, a Phase I single dose study was carried out to assess the safety profile of Sii HibPRO in healthy adult male volunteers. Subsequently, in Phase III pre-licensure study, immunogenicity and safety of Sii HibPRO was assessed and compared with Hib tetanus conjugate vaccine (Act-HIB) of Aventis, France. Immunogenicity was evaluated based upon serum anti-PRP IgG antibody concentrations by ELISA at prevaccination and one month each after the second and third dose. Safety was evaluated by recording details of adverse events after each dose of the vaccine. Postvaccination after the third dose, there was 100% seroprotection (anti PRP IgG titre >or= 0.15 microg/ml) in both the groups. Long term protection (>or=1 microg/ml) was achieved in 95.2% and 98.06% infants in Sii HibPRO and Act-HIB groups, respectively. At 15 months, prior to booster dose, 30 children in each group were evaluated and all were found to be seroprotected. Post booster, all of them responded with a strong boost response. Safety of Sii HibPRO was re-established in the post marketing surveillance in which 2,739 doses were administered to 1,029 infants, in 23 cities across India.

Safety and immunogenicity of diphtheria-tetanus-pertussis vaccine and hepatitis B vaccine as a new tetravalent combination (DTwP/HB) administered alone and at separate sites (DTwP and HB) including comparison with standard commercially available combination vaccine in Indian infants 6-14 weeks of age.

An open, comparative study was conducted at two tertiary care hospitals in India to assess immunogenicity and reactogenicity following administration of the DTwP/HB combination vaccine (Q-Vac) alone and DTwP and HB (Genevac B) vaccines at separate sites. These vaccines manufactured by Serum Institute of India, Ltd. (SIIL), Pune were compared with DTwP/HB vaccine (Tritanrix HB) manufactured by GlaxoSmithKline (GSK) in infants aged 6-14 weeks. The sample size comprised 447 infants who received DTwP/HB vaccine (Group A-150, SIIL) or DTwP and HB (Group B-147, SIIL) vaccines at separate sites or DTPw/HB vaccine (Group C-150, GSK), in a dose of 0.5 ml intra-muscularly. Pre and postvaccination IgG antibodies were determined by ELISA. Postvaccination, in Group A seroprotection was 99.3%, 100%, 96% and 100% to Diphtheria, Tetanus, Pertussis and HBs components respectively. In Group B (n = 147) it was 98.6%, 100%, 95.9% and 99.3% and in Group C (n = 150), it was 96%, 99.3%, 93.3% and 98.6% to D, T, P and HBs component of the vaccine. Postvaccination, geometric mean titres for each component were comparable across three groups by analysis of variance (ANOVA). Adverse events observed were within the range quoted in literature and no Serious Adverse Event (SAE) was observed. Reactogenicity profile in all three groups was comparable. Q-Vac vaccine manufactured by SIIL was found to be safe and immunogenic. Hepatitis B (HB) component did not interfere with the immune response to DTwP components of the vaccine.