Hydrogen sulfide: an emerging component against abiotic stress in plants.

As a result of climate change, abiotic stresses are the most common cause of crop losses worldwide. Abiotic stresses significantly impair plants' physiological, biochemical, molecular and cellular mechanisms, limiting crop productivity under adverse climate conditions. However, plants can implement essential mechanisms against abiotic stressors to maintain their growth and persistence under such stressful environments. In nature, plants have developed several adaptations and defence mechanisms to mitigate abiotic stress. Moreover, recent research has revealed that signalling molecules like hydrogen sulfide (H2 S) play a crucial role in mitigating the adverse effects of environmental stresses in plants by implementing several physiological and biochemical mechanisms. Mainly, H2 S helps to implement antioxidant defence systems, and interacts with other molecules like nitric oxide (NO), reactive oxygen species (ROS), phytohormones, etc. These molecules are well-known as the key players that moderate the adverse effects of abiotic stresses. Currently, little progress has been made in understanding the molecular basis of the protective role of H2 S; however, it is imperative to understand the molecular basis using the state-of-the-art CRISPR-Cas gene-editing tool. Subsequently, genetic engineering could provide a promising approach to unravelling the molecular basis of stress tolerance mediated by exogenous/endogenous H2 S. Here, we review recent advances in understanding the beneficial roles of H2 S in conferring multiple abiotic stress tolerance in plants. Further, we also discuss the interaction and crosstalk between H2 S and other signal molecules; as well as highlighting some genetic engineering-based current and future directions.

Self-assembly of tetrahedral and trigonal antiprismatic clusters [Fe4(L4)4] and [Fe6(L5)6] on the basis of trigonal tris-bidentate chelators.

In a one-pot reaction, the tetranuclear iron chelate complex [Fe4(L4)4] 6 was generated from benzene-1,3,5-tricarboxylic acid trichloride (4), bis-tert-butyl malonate (5a), methyllithium, and iron(II) dichloride under aerobic conditions. Alternatively, hexanuclear iron chelate complex [Fe(L5)6] 7 was formed starting from bis-para-tolyl malonate (5b) by employing identical reaction conditions to those applied for the synthesis of 6. The clusters 6 and 7 are present as racemic mixtures of homoconfigurational (delta,delta,delta,delta)/(lambda,lambda,lambda,lambda)-fac or (delta,delta,delta,delta,delta,delta)/(lambda,lambda,lambda,lambda,lambda,lambda)-fac stereoisomers. The structures of 6 and 7 were unequivocally resolved by single-crystal X-ray analyses. The all-iron(III) character of 6 and 7 was determined by Mössbauer spectroscopy.

Childhood tuberculosis (Part-I). Epidemiology, pathogenesis, clinical profile.

PIP: This paper focuses on the pathogenesis and clinical profile of tuberculosis (TB), a bacterial infection caused by Mycobacterium tuberculosis characterized by granuloma formation in infected tissues and by cell-mediated hypersensitivity. TB remains a major cause of morbidity and mortality worldwide and is the most common cause of death from a single infectious disease, particularly in children. Nearly 40 million children are likely to be exposed to the risk of TB and nearly 3-4 million children below age 5 years are estimated to be infected and may progress to disease. TB accounts for 10-15% of all pediatric deaths in a number of Indian hospitals. Factors such as low socioeconomic status, infections, drugs such as steroids, and age predisposes a person to TB. Childhood TB is classified as follows: 1) asymptomatic mantoux positive, 2) symptomatic mantoux positive, 3) primary pulmonary complex, 4) progressive pulmonary disease, 5) disseminated TB, 6) cervical and abdominal TB, 7) tubercular meningitis, 8) progressive bacillus Calmette-Guerin (BCG) disease, and 9) congenital tuberculosis. Among the various symptom complexes of childhood TB are failure to gain weight or weight loss, sudden onset of fever with erythema nodosum and phlyctenular conjunctivitis, failure to gain weight with respiratory wheezing. The direct and indirect impact of HIV infection on the development of TB in children is also discussed.^ieng

Childhood tuberculosis (part-II) (diagnosis and management).

PIP: This article focuses on the diagnosis and management of childhood tuberculosis (TB). Diagnostic tests for childhood TB can be classified into five groups: 1) intradermal skin tests; 2) mycobacterial detection and isolation; 3) immune diagnosis; 4) nonspecific tests; and 5) radiologic investigation. Of the intradermal skin tests, the Mantoux test is the most accurate, definitive, and reliable. The three diagnostic scoring systems discussed in this article are 1) WHO Provisional Guidelines for Diagnosis of TB in Children, 2) Udanis Simple Scoring Technique Criteria, and c) Kenneth Jones Scoring. Moreover, TB has been classified into five groups based on clinical types to optimize treatment protocol. These groups are presented in the article together with the treatment indications.^ieng

Gastric cancer profile in kashmiri population with special dietary habits.

The present study is a comprehensive retrospective analysis of 1341 gastric neoplasms out of 10 733 individuals subjected to upper gastrointestinal endoscopy at the main teaching cum referral hospital in the Kashmir Valley. Of these 78% were males and 22% females, majority being in the age group of 41-60 years with 60% of the patients being smokers. On endoscopy, the commonest site of cancer was the body of stomach 40.7%, followed by the antrum 35.5% and the cardiac region 23.8%. Endoscopic features revealed nodular masses 39%, polypoid masses 21%, malignant ulcers 11%, infiltrative masses 12%, rounded tumor masses 9%, linitus plastica 5% and early gastric carcinoma 3%. Histology revealed adenocarcinoma 91%, (including mucoid carcinoma 9%, and schirrous carcinoma 7%), leiomyosarcoma 7%, and reticulum cell sarcoma 2%. No significant association between Helicobacter pylori infection and gastric cancer was observed in a short study out of these patients. The peculiar geography and some special dietary habits with a possible familial predisposition may have a bearing on the high risk of gastric cancer in the valley.

Helicobacter pylori Infection in Endoscopic Biopsy Specimens of Gastric Antrum: Laboratory Diagnosis and Comparative Efficacy of Three Diagnostic Tests.

Aims and objectives The present study was undertaken to compare the diagnostic yield of three available test procedures for detecting Helicobacter pylori (H. pylori) infection in endoscopic biopsies.Methods H. pylori infection was sought in 150 patients referred for upper gastrointestinal (GI) endoscopy. Multiple (about six) biopsy specimens were taken from pyloric antrum in each patient. Two biopsy specimens were subjected to one minute endoscopy room test - OMERT (a modified form of urease test), two were sent for histopathological analysis, where multiple sections were subjected to Giemsa staining and two were sent for microbiological evaluation after Gram's staining of heat fixed biopsy material.Results H. pylori positivity using histology, microbiology and OMERT was observed to be 33%, 30% and 27% respectively. However, overall 40% patients were infected when the results from three test procedures were combined, as H. pylori positivity was repeated more than once by these procedures separately. Histology was found to be superior to other two tests in our study, especially when multiple sections were examined, for the distribution of the organism was patchy. Amongst the infected, H. pylori was seen in only 30% of all 3-8 sections cut from a biopsy, whereas in 70% it was noted in a single section only.Conclusion The study revealed that histology has the highest detection rate and can be chosen as the "gold standard" amongst the three low cost test procedures available at present in our setup.

Water-borne hepatitis E virus epidemic in Islamabad, Pakistan: a common source outbreak traced to the malfunction of a modern water treatment plant.

During December 1993 and in the first three months of 1994, an explosive water-borne epidemic of hepatitis E virus (HEV) occurred in two sectors of Islamabad, Pakistan. In a survey of a population of 36,705 individuals, a total of 3,827 cases of acute icteric hepatitis were recorded with an overall attack rate (AR) of 10.4%. The etiologic role of HEV in the epidemic was proven by demonstrating anti-HEV IgG and HEV IgM in the tested serum samples. The water-borne nature of the epidemic was suggested by a study of the case distribution according to water supply. Prior to the epidemic, there had been an operational breakdown in a water treatment plant that distributed water to the affected areas while transforming its purification system from slow sand to rapid sand filtration. The primary source of water for the plant was derived from a heavily contaminated stream. The highest AR (16.3%) was observed in the areas where the source of drinking water was exclusively from the purification plant, followed by ARs of 12.4% and 5.3% for those receiving 50% and 30% or less of their water supply from the treatment plant, respectively, while the lowest AR (1.8%) was observed in the neighboring areas that did not receive water from this source. The AR was significantly higher in the group 11-30 years of age (15.3%) as compared with children less than 11 years of age (1.4%) and also relative to the group greater than 30 years of age (10.5%). The AR among the 162 recorded pregnant females was 21.6%, which was higher than that found among nonpregnant females of child-bearing age (10.9%). All four reported adult deaths occurred among females in their third trimester of pregnancy with a case fatality rate of 11.4%, while the other four fatal cases were newborn infants of mothers with acute icteric hepatitis. Although the aggregation of cases within households was significantly related to family size, the temporal relationship between cases in households with two or more cases revealed that 83.7% of 1,463 presumed secondary cases occurred within one month of the first case in the same household, which is not suggestive of person-to-person transmission of disease. The termination of providing water from the source was effected, which was followed by an apparent decrease in cases.

Effect of diazepam sedation on arterial oxygen saturation and patient tolerance during esophagogastroduodenoscopy.

The impact of intravenous (I/V) diazepam sedation on arterial oxygen saturation (SaO(2)) and patient tolerance was studied in 100 patients in the age group of (27-60) years, who were subjected to esophagogastroduodenoscopy (EGD) for different indications. Equal number of patients in the same age group, who did not receive the sedation acted as controls. It was observed that SaO(2) showed a transient fall during the first few minutes of the endoscopic procedure even without sedation and diazepam administration did not significantly (p > 0.05) aggravate this oxygen desaturation. It was also observed that diazepam sedation increased the procedure tolerance of the patients when compared with controls (p < 0.01). In conclusion, it was inferred that I/V diazepam may act as a safe and favourable sedative for EGD.

Helicobacter pylori infection in endoscopic biopsy specimens of gastric cancer: a preliminary evaluation in a high risk population of kashmir valley.

OBJECTIVE: The aim of the present study was to assess the prevalence of Helicobacter pylori (H. pylori) infection in Kashmiri patients with gastric cancer and to compare this with a matched control population. METHODS: Fifty patients with gastric cancer and thirty age/sex matched controls were included in the study. All the subjects were hailing from Kashmir Valley. For detection of H. pylori, biopsy specimens were used both from cases and controls. RESULTS: An insignificant association was shown between H. pylori and both intestinal and diffuse type of gastric cancer. CONCLUSIONS: The data provides support against the significant association between H. pylori and gastric cancer in this part of world, a place where the age standardized incidence of gastric cancer is alarmingly high. We conclude that other factors like personal and special dietary habits of Kashmiri population may be more important for the development of gastric cancer.

Trichophytobezoar without gastrointestinal complaints.

Gastrointestinal complaints may be the presenting symptoms of trichophytobezoar. We report a patient, who had an epigastric lump and enlarged lymph nodes on the left side of the neck, but without any gastrointestinal complaint. The clinical diagnosis suggested lymphoma or gastric cancer with secondary masses in the cervical lymph nodes. The diagnosis ultimately proved to be tubercular lymphadenitis on biopsy and gastric trichophytobezoar on endoscopy and laparotomy.

Endoscopic evaluation of peptic ulcer disease during ramadan fasting.

The effects of fasting on peptic ulcer disease were evaluated in a prospective study, involving 23 fasting patients who underwent endoscopy before and after Ramadan. Eighteen patients took an H(2)-blocker (ranitidine, 150 mg twice daily) regularly at "Suhur" and "Iftar" as prescribed, while 5 were drug defaulters. On the first endoscopy the diagnosis in 4 patients was active acute duodenal ulcer (AADU), in 8 patients was active chronic duodenal ulcer (ACDU) in 8 patients was healed duodenal ulcer (HDU), in 2 patients was erosive duodenitis (ED), and in 1 patient was chronic gastric ulcer (CGU). All of the patients with AADU showed signs of healing on repeat endoscopy. None of the ACDU patients showed signs of healing on repeat endoscopy. Instead, 7 patients in this group bled during fasting. All of the 5 drug defaulters belonged to the ACDU group. One patient in the HDU group had developed an active ulcer near the previous scar, as which was seen on repeat endoscopy. The 2 patients with ED showed signs of healing, while the only patient with CGU had bled from the same ulcer as seen on repeat endoscopy. The results were compared with those of 15 nonfasting control subjects (6 patients with ACDU, 3 with HDU, and 6 with ED as diagnosed on the first endoscopy), who took an H(2)-blocker regularly. The repeat endoscopy did not show any change in these patients. In conclusion, we inferred that Ramadan fasting may prove hazardous in patients with peptic ulcer disease in general and with active chronic ulcers in particular, although the fact that only 23 patients volunteered for this study, of whom 5 were drug defaulters, is a limitation.

Serum immunoglobulin profile in normal Kashmiri adults.

Serum levels of the immunoglobulins IgG, IgA and IgM were estimated in 102 apparently healthy Kashmiri adults in the age group of 16-60 years, using single radial immunodiffusion method of Mancini et al. The mean serum levels of IgG, IgA and IgM were observed to be 1289.19 +/- 234.9, 216.18 +/- 50.70 and 118.97 +/- 41.88 respectively. No significant difference in the mean serum levels was observed between the two sexes as such, but IgM showed a significant increase in females in the age group of 16-30 years. IgA showed a significant increase with age, with no such increase in case of IgG and IgM.