Unravelling geospatial distribution and genetic diversity of greenhouse whitefly, Trialeurodes vaporariorum (Westwood) from Himalayan Region

The Greenhouse whitefly (GWF), Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae), is a destructive pest that affects protected cultivation worldwide. The Indian Himalayan region is particularly vulnerable to GWF introduction, invasion, and spread due to the expansion of protected cultivation and climate change. In this study, we collected 32 naturally occurring GWF populations, mainly from the Uttarakhand state in the Indian Himalayan region, to investigate the distribution pattern and genetic diversity of T. vaporariorum. Our sampling was representative of the region's vegetation diversity and geographical location, and we collected samples from multiple sites within each locality to account for local variations. The mtCOI gene was used to accurately detect and identify GWF and to sequence haplotypes prevalent in the Uttarakhand state. The maximum likelihood method used for phylogenetic studies revealed that all 32 whitefly samples in this study belonged to T. vaporariorum and were prevalent in all the collected localities. Our population genetic study using mtCOI showed variation within T. vaporariorum populations, with 20 distinct haplotypes present. Notably, haplotype 2 (H2) was the most dominant haplotype among the sampled populations. These results provide fundamental knowledge for understanding the geographical distribution and ecology of T. vaporariorum in the Uttarakhand state of the Indian Himalayan region. The discovery of geospatial and genetic diversity of GWF in the Himalayan region underscores the importance of pest alertness, research prioritization, and the development of sustainable management strategies to protect crops.

Virulence and genetic analysis of Puccinia graminis tritici in the Indian sub-continent from 2016 to 2022 and evaluation of wheat varieties for stem rust resistance

Wheat stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), has re-emerged as one of the major concerns for global wheat production since the evolution of Ug99 and other virulent pathotypes of Pgt from East Africa, Europe, Central Asia, and other regions. Host resistance is the most effective, economic, and eco-friendly approach for managing stem rust. Understanding the virulence nature, genetic diversity, origin, distribution, and evolutionary pattern of Pgt pathotypes over time and space is a prerequisite for effectively managing newly emerging Pgt isolates through host resistance. In the present study, we monitored the occurrence of stem rust of wheat in India and neighboring countries from 2016 to 2022, collected 620 single-pustule isolates of Pgt from six states of India and Nepal, analyzed them on Indian stem rust differentials, and determined their virulence phenotypes and molecular genotypes. The Ug99 type of pathotypes did not occur in India. Pathotypes 11 and 40A were most predominant during these years. Virulence phenotyping of these isolates identified 14 Pgt pathotypes, which were genotyped using 37 Puccinia spp.-specific polymorphic microsatellites, followed by additional phylogenetic analyses using DARwin. These analyses identified three major molecular groups, demonstrating fewer lineages, clonality, and long-distance migration of Pgt isolates in India. Fourteen of the 40 recently released Indian wheat varieties exhibited complete resistance to all 23 Pgt pathotypes at the seedling stage. Twelve Sr genes were postulated in 39 varieties based on their seedling response to Pgt pathotypes. The values of slow rusting parameters i.e. coefficient of infection, area under disease progress curve, and infection rates, assessed at adult plant stage at five geographically different locations during two crop seasons, indicated the slow rusting behavior of several varieties. Six Sr genes (Sr2, Sr57, Sr58, Sr24, Sr31, and Sr38) were identified in 24 wheat varieties using molecular markers closely linked to these genes. These findings will guide future breeding programs toward more effective management of wheat stem rust.

Evaluation of Psychological Impact of COVID-19 on Health-Care Workers

BACKGROUND

Little information is available from India about the psychological impact of COVID-19 on helath-care workers.

AIM

The current study aimed to evaluate the psychological issues among the health-care workers (HCW) during the COVID-19 pandemic.

MATERIALS AND METHODS

An online survey using Survey Monkey® platform was carried out to evaluate depression (using Patient Health Questionnaire-9), anxiety (using Generalized Anxiety Disorder Questionnaire-7), and other psychological issues (using a self-designed questionnaire).

RESULTS

The study sample comprised 303 participants with a mean age of 41.2 (standard deviation: 11.1) years. A majority of them were male (69%) and married (79.9%). Nearly half (46.2%) of the participants had either anxiety disorder or depression or both and 12.9% of HCW had suicidal behavior. Higher level of anxiety and depression scores were associated with being female, having undergone quarantine, directly involved in the care of COVID-19 patients, and younger age (<30 years). Higher prevalence of depression and anxiety disorder was seen in younger (<30 years) age group, being a doctor (compared to paramedics). In addition, higher prevalence of depression was seen in those who were directly involved in the care of patients with COVID-19 infection.

CONCLUSION

About half of the HCWs are suffering from psychiatric morbidity, specifically anxiety, in the wake of the COVID-19 pandemic. There is a need to assess all the HCWs for psychiatric morbidity and provide them with psychological support.

Advanced Object Detection in Bio-Medical X-Ray Images for Anomaly Detection and Recognition

The human vision system is mimicked in the format of videos and images in the area of computer vision. As humans can process their memories, likewise video and images can be processed and perceptive with the help of computer vision technology. There is a broad range of fields that have great speculation and concepts building in the area of application of computer vision, which includes automobile, biomedical, space research, etc. The case study in this manuscript enlightens one about the innovation and future scope possibilities that can start a new era in the biomedical image-processing sector. A pre-surgical investigation can be perused with the help of the proposed technology that will enable the doctors to analyses the situations with deeper insight. There are different types of biomedical imaging such as magnetic resonance imaging (MRI), computerized tomographic (CT) scan, x-ray imaging. The focused arena of the proposed research is x-ray imaging in this subset. As it is always error-prone to do an eyeball check for a human when it comes to the detailing. The same applied to doctors. Subsequently, they need different equipment for related technologies. The methodology proposed in this manuscript analyses the details that may be missed by an expert doctor. The input to the algorithm is the image in the format of x-ray imaging; eventually, the output of the process is a label on the corresponding objects in the test image. The tool used in the process also mimics the human brain neuron system. The proposed method uses a convolutional neural network to decide on the labels on the objects for which it interprets the image. After some pre-processing the x-ray images, the neural network receives the input to achieve an efficient performance. The result analysis is done that gives a considerable performance in terms of confusion factor that is represented in terms of percentage. At the end of the narration of the manuscript, future possibilities are being traces out to the limelight to conduct further research.

Psychological impact of COVID-19 lockdown: An online survey from India

BACKGROUND

The COVID-19 pandemic has led to a complete shut-down of the entire world and almost all the countries are presently in a "lockdown" mode. While the lockdown strategy is an essential step to curb the exponential rise of COVID-19 cases, the impact of the same on mental health is not well known.

AIM

This study aimed to evaluate the psychological impact of lockdown due to COVID-19 pandemic on the general public with an objective to assess the prevalence of depression, anxiety, perceived stress, well-being, and other psychological issues.

MATERIALS AND METHODS

It was an online survey conducted under the aegis of the Indian Psychiatry Society. Using the Survey Monkey platform, a survey link was circulated using the Whatsapp. The survey questionnaire included perceived stress scale, Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Warwick-Edinburgh Mental Well-being Scale to assess perceived stress, anxiety, depression, and mental well-being, respectively. The survey link was circulated starting from April 6, 2020 and was closed on April 24, 2020.

RESULTS

During the survey, a total of 1871 responses were collected, of which 1685 (90.05%) responses were analyzed. About two-fifth (38.2%) had anxiety and 10.5% of the participants had depression. Overall, 40.5% of the participants had either anxiety or depression. Moderate level of stress was reported by about three-fourth (74.1%) of the participants and 71.7% reported poor well-being.

CONCLUSIONS

The present survey suggests that more than two-fifths of the people are experiencing common mental disorders, due to lockdown and the prevailing COVID-19 pandemic. This finding suggests that there is a need for expanding mental health services to everyone in the society during this pandemic situation.

Phonon and magnetoelastic coupling in Al0.5Ga0.5FeO3: Raman, magnetization and neutron diffraction studies

The intriguing coupling phenomena among spin, phonon, and charge degrees of freedom in materials having magnetic, ferroelectric and/or ferroelastic order have been of research interest for the fundamental understanding and technological relevance. We report a detailed study on structure and phonons of Al_0.5Ga_0.5FeO₃ (ALGF), a lead-free magnetoelectric material, carried out using variable temperature dependent powder neutron diffraction and Raman spectroscopy. Neutron diffraction studies suggest that Al³⁺ ions are distributed in one tetrahedrally (BO₄) and three octahedrally (BO₆) coordinated sites of the orthorhombic (Pc2₁n) structure and there is no structural transition in the temperature range of 7-800 K. Temperature dependent field-cooled and zero-field-cooled magnetization studies indicate ferrimagnetic ordering below 225 K (T_N), and that is reflected in the low temperature powder neutron diffraction data. An antiferromagnetic type arrangement of Fe³⁺ ions with net magnetic moment of 0.13 μ_B/Fe³⁺ was observed from powder neutron diffraction analysis and it corroborates the findings from magnetization studies. At the magnetic transition temperature, no drastic change in lattice strain was observed, while significant changes in phonons were observed in the Raman spectra. The deviation of several mode frequencies from the standard anharmonicity model in the ferrimagnetic phase (below 240 K) is attributed to coupling effect between spin and phonon. Spin-phonon coupling effect is discernable from Raman bands located at 270, 425, 582, 695, 738, and 841 cm^-1. Their coupling strengths (λ) have been estimated using our phonon spectra and magnetization results. BO_n (n = 4, 6) libration (restricted rotation) mode at 270 cm^-1 has the largest coupling constant (λ∼ 2.3), while the stretching vibrations located at 695 and 738 cm^-1 have the lowest coupling constant (λ∼ 0.5). In addition to the libration mode, several internal stretching and bending modes of polyhedral units are strongly affected by spin ordering.

Genetic analysis of maydis leaf blight resistance in subtropical maize (Zea mays L.) germplasm

Knowledge on the genetics of maydis leaf blight (MLB) is crucial to breed the resistant maize cultivars to combat disease epidemics as a sustainable and cost-effective approach. The present investigation was framed to understand the genetics of MLB resistance in subtropical maize. Two contrasting genotypes CM119 (susceptible) and SC-7-2-1-2-6-1 (resistant) were used to generate six genetic populations, namely P₁, P₂, F₁, F₂, BC₁P₁ and BC₁P₂, and evaluated in three target environments for MLB resistance under artificial epiphytotic condition. The CM119 and SC-7-2-1-2-6-1 showed susceptible and resistant reactions with mean disease reaction of 3.89-3.98 and 1.88-2.00, respectively. The derived generations, namely F₁, F₂, BC₁P₁ and BC₁P₂ showed mean disease reaction of 2.15-2.28, 2.44-2.51, 2.19-2.24 and 2.22-2.28, respectively in the test locations. The segregating generations (F₂: 0.35-0.37; BC₁P₁: 0.24-0.29 and BC₁P₂: 0.17-0.20) showed variation for MLB disease resistance over the parental and first filial generations (P₁: 0.11-0.17; P₂: 0.08-0.13 and F₁: 0.12-0.14). The genetic analysis of MLB resistance revealed the nonallelic interactions of duplicate epistasis type across the test locations. Among the gene interactions, dominance x dominance [l] effect was predominant over additive x additive [i] and additive x dominance [j] effects. The segregation analysis and the prediction of the number of major loci revealed at least two major genes associated with MLB tolerance in subtropical maize. Our investigation paved the foundation for the improvement of subtropical maize germplasm of MLB resistance.

Bio-efficacy of chitinolytic Bacillus thuringiensis isolates native to northwestern Indian Himalayas and their synergistic toxicity with selected insecticides

Pesticidal properties of Bacillus thuringiensis and its associated toxic proteins is an ever-growing science with potential implications in biological pest management. In the present study 80 Bacillus thuringiensis isolates native to Uttarakhand Himalayas were evaluated for chitinolytic activity and potent ones (11 isolates) were further subjected to multiphasic characterization for their antifungal, insecticidal and synergistic properties with selected chemical insecticides. Although all the 11 potent isolates were biologically active, only three isolates (VLBt27, VLBt109 and VLBt238) showed >90% inhibition in radial growth of 3 out of 4 tested plant pathogenic fungi (Rhizoctonia solani, Fusarium oxysporum, Alternaria pori and Pyricularia oryzae). The key antagonism was manifested in the form of disruptions in growing tips and uneven mycelial thickenings. In insect bioassays (against Helicoverpa armigera, Mythimna separata and Thysanoplusia orichalcea), no considerable direct mortality was observed. However, the larval weight reduction was prominent in four isolates (VLBt27, VLBt38, VLBt109 and VLBt135) which accounts to >75% in first instar larvae of H. armigera. Joint action of these four isolates with chemical insecticides showed an overall additive interaction against Brevicoryne brassicae and synergism against H. armigera. All the isolates were compatible with tested insecticides at their field recommended doses except for chlorpyriphos with around 130 kDa protein as chitinase. The study identified VLBt27 and VLBt109, two native isolates of B. thuringiensis with potential antagonistic activity and synergism as well. These isolates have possible implications as single strategy against two diverse pest problems (pathogenic fungi and phytophagous insect) of agriculture with a view of reduced pesticide application.

An Innovative Technique to Encrypt Videos for Authenticity or Ownership Protection Using PCA Applied in E-Commerce

Whenever there is a copywrite protection an article or official material it is usually encrypted with specific information that can only be decrypted by the person who created the document and the owner can claim the ownership of the original document. This type of encryption is called watermarking. This can be used by different e-commerce sites like Netflix, Amazon Prime, who can protect their media through the process of watermarking. As computational power is increasing along with applied mathematics, the application area is now available for multimedia files. This article focuses on encryption of video files so that the owner can claim the ownership of the created video file. The technology also enables the secrecy of the encryption between the sender and the receiver so that receiver can decrypt the file and receive the ownership that is being transferred from the user. In another way, any e-commerce site can claim the ownership of their media if it is pirated.

Structural transformations and physical properties of (1 - x) Na0.5Bi0.5TiO3 - x BaTiO3 solid solutions near a morphotropic phase boundary

Piezoelectric and other physical properties are significantly enhanced at (or near) a morphotropic phase boundary (MPB) in ferroelectrics. MPB materials have attracted significant attention owing to both fundamental physics as well as the possibility of well-regulated energy and information storage devices which are dominated by lead (Pb)-based materials. Here, we report the crystal structure, Raman spectra, dielectric constant and polarization near the MPB of lead free (1  -  x) Na_0.5Bi_0.5TiO₃  -  x BaTiO₃ (0.00  ⩽  x  ⩽  0.10) solid-solution, prepared by sol-gel auto combustion technique and sintered by microwave sintering technique. With the addition of BaTiO₃ into Na_0.5Bi_0.5TiO₃, it induces a structural phase transition from R3c (a single phase) to R3c  +  P4mm (a dual phase) close to x  =  0.06 and 0.07 and transform to a high symmetry tetragonal phase P4mm at higher compositions (x  =  0.08 to 0.10) as evident from our x-ray Rietveld refinement and Raman spectroscopic results. We perform first-principles calculations based on density functional theory that confirm a structural transition from a rhombohedral to a tetragonal phase under increasing x. In the prepared solid solution, an anomalous enhancement of remnant polarization ([Formula: see text]) was observed for x  =  0.06 and 0.07, which has been explained based on the existence of the MPB. On the other hand, the value of coercive field [Formula: see text] was found to be decreased linearly from x  =  0.00 to 0.06; it is constant for higher compositions. Further details of the ferroelectric properties on the electric field poled samples have been studied and compared with the as-grown (unpoled) samples.

Environmental Adaption Method

This article describes how optimization is a process of finding out the best solutions among all available solutions for a problem. Many randomized algorithms have been designed to identify optimal solutions in optimization problems. Among these algorithms evolutionary programming, evolutionary strategy, genetic algorithm, particle swarm optimization and genetic programming are widely accepted for the optimization problems. Although a number of randomized algorithms are available in literature for solving optimization problems yet their design objectives are same. Each algorithm has been designed to meet certain goals like minimizing total number of fitness evaluations to capture nearly optimal solutions, to capture diverse optimal solutions in multimodal solutions when needed and also to avoid the local optimal solution in multi modal problems. This article discusses a novel optimization algorithm named as Environmental Adaption Method (EAM) foable 3r solving the optimization problems. EAM is designed to reduce the overall processing time for retrieving optimal solution of the problem, to improve the quality of solutions and particularly to avoid being trapped in local optima. The results of the proposed algorithm are compared with the latest version of existing algorithms such as particle swarm optimization (PSO-TVAC), and differential evolution (SADE) on benchmark functions and the proposed algorithm proves its effectiveness over the existing algorithms in all the taken cases.

Effect of dehulling, germination and cooking on nutrients, anti-nutrients, fatty acid composition and antioxidant properties in lentil (Lens culinaris)

The changes in chemical composition, antioxidant activity and fatty acid composition of lentil flour after dehulling, germination and cooking of seeds were investigated. Dehulling showed no significant effect on protein content, however, protein content decreased in most of the varieties after germination and cooking. Total soluble sugars (TSS) content increased significantly after dehulling (2.0-41.64 %) and cooking (2.08-31.07 %) whereas, germination had no significant effect on TSS content. Total lipids increased significantly after dehulling (21.56-42.86 %) whereas, it decreased significantly after germination (2.97-26.52 %) and cooking (23.05-58.63 %). Cooking was more effective than other methods in reducing trypsin inhibitors (80.51-85.41 %). Dehulling was most effective in reducing tannins (89.46-92.99 %) and phytic acid (52.63-60.00 %) content over raw seed. Myristic, palmitic, stearic, oleic and linoleic acid content decreased while linolenic acid content increased after dehulling. Dehulling, germination and cooking decreased the content of antioxidant metabolite (gallic acid, catechin and quercetin) and also antioxidant activities. Raw samples followed by germinated samples showed the highest concentrations of phytochemicals responsible for antioxidant activity and also the antioxidant capacities. Present study showed germination and cooking would be useful in formulation and development of lentil based functional foods for human health benefits.

Breeding high-yielding drought-tolerant rice: genetic variations and conventional and molecular approaches

The increased occurrence and severity of drought stress have led to a high yield decline in rice in recent years in drought-affected areas. Drought research at the International Rice Research Institute (IRRI) over the past decade has concentrated on direct selection for grain yield under drought. This approach has led to the successful development and release of 17 high-yielding drought-tolerant rice varieties in South Asia, Southeast Asia, and Africa. In addition to this, 14 quantitative trait loci (QTLs) showing a large effect against high-yielding drought-susceptible popular varieties were identified using grain yield as a selection criterion. Six of these (qDTY 1.1 , qDTY 2.2 , qDTY 3.1 , qDTY 3.2 , qDTY 6.1 , and qDTY 12.1 ) showed an effect against two or more high-yielding genetic backgrounds in both the lowland and upland ecosystem, indicating their usefulness in increasing the grain yield of rice under drought. The yield of popular rice varieties IR64 and Vandana has been successfully improved through a well-planned marker-assisted backcross breeding approach, and QTL introgression in several other popular varieties is in progress. The identification of large-effect QTLs for grain yield under drought and the higher yield increase under drought obtained through the use of these QTLs (which has not been reported in other cereals) indicate that rice, because of its continuous cultivation in two diverse ecosystems (upland, drought tolerant, and lowland, drought susceptible), has benefited from the existence of larger genetic variability than in other cereals. This can be successfully exploited using marker-assisted breeding.

Neonatal abstinence syndrome

Intrauterine exposure to drugs by mothers is not an uncommon finding ine our society. Due to the mother's suppression of a medical history, the diagnosis of neonatal abstinence syndrome is often missed. We report a case of a term, female, newborn, who presented with the following features;e restlessness, inconsolable crying, along with sweating, vigorous sucking; andadiarrhoea. No conclusion was derived from routine investigations. Eventually, with a high degree of suspicion regarding maternal drug addiction, her history was reviewed and it was discovered that the mother was a heroin addict. The baby was diagnosed as a case of Neonatal Abstinence Syndrome. The neonate was successfully managed thereafter and discharged.

Biological and molecular characterization of a begomovirus associated with yellow mosaic vein mosaic disease of pumpkin from Northern India

The biological and molecular properties of Squash leaf curl China virus from Varanasi, India (SLCCNV-IN[IN:Var:Pum]) were characterized. SLCCNV-IN[IN:Var:Pum] could be transmitted by grafting and through whitefly transmission. The complete DNA-A and DNA-B components were amplified through PCR using specific DNA-A and DNA-B primers. The DNA-A of the isolate was comprised of 2,738 nucleotides, encoding typical six open reading frames, and DNA-B of 2,704 nucleotides, encoding two ORFs. Genome organization of the isolate was typical of an old world bipartite begomovirus. Comparisons showed that DNA-A and its intergenic region have the highest sequence identity (97.6 and 97.4%, respectively) with the SLCCNV-IN[IN:Luc:Pum]; (DQ026296). This data suggested that the isolate is a same begomovirus species for which the name Squash leaf curl China virus-India[India:Varanasi:Pumpkin] is proposed. DNA-B showed maximum sequence identity (89.2%) with SLCCNV-IN[IN:Coi:Pum] (AY184488). Phylogenetic analysis of the present isolate showed close relationship to other cucurbit-infecting geminiviruses. This is the first evidence of occurrence of the bipartite Squash leaf curl China virus associated with severe yellow mosaic disease of pumpkin in northern India.

A clinical study on cortisol and certain metabolites in some chronic psychosomatic disorders

Present clinical study involved two groups of psychosomatic disorders, bronchial asthma and rheumatoid arthritis. In the study, the levels of plasma cortisol, blood glucose, total cholesterol and triglycerides were estimated in 125 clinical subjects, (50 normal controls, and 40 having bronchial asthma and 35 suffering from rheumatoid arthritis. The results showed a significant change in the levels of plasma cortisol and blood glucose in both the stressed clinical groups' vis-à-vis normal controls. The levels of atherogenic lipids (total cholesterol and triglycerides) were found quite elevated in both the diseased groups. However, in rheumatoid arthritis, the physiological changes were relatively more pronounced. The findings of this study indicate that rheumatoid arthritis is a relatively more chronic and late onset disorder as the functional performance of hypothalamopituitary-adrenocortical axis gradually declines with passage of time and the ability of the adrenocortical response to return to normalcy becomes impaired.

Antibiotic Susceptibility of Helicobacter pylori Clinical Isolates: Comparative Evaluation of Disk-Diffusion and E-Test Methods

Antimicrobial susceptibility of 25 Helicobacter pylori strains isolated from patients with acid peptic diseases were tested for in vitro sensitivity to commonly used antibiotics using disk-diffusion and E-test, methods. All strains tested were susceptible to tetracycline by E-test, with the minimum inhibitory concentration (MIC) values being <0.125 microg/ml for all strains except for 6 (<0.023 microg/ml). However 1 strain was resistant by disk-diffusion method. One strain was resistant to clarithromycin both by disk diffusion and E-test (MIC <48 microg/ml), and 1 strain was resistant only by disk diffusion. Only one strain was resistant to amoxicillin by disk diffusion and E-test (MIC >256 microg/ml). For ciprofloxacin, three strains were resistant by disk diffusion and two by E-test (MIC <32 microg/ml). Sixteen strains were resistant to metronidazole by disk diffusion and E-test (MIC >or= 8 microg/ml), and 1 was resistant only by E-test (MIC <48 microg/ml). Overall, 64% of the strains were resistant to metronidazole. The MIC for metronidazole was also tested by agar-dilution method, and metronidazole resistant strains had an, MIC >8 microg/ml. The disk-diffusion method showed excellent correlation with E-test results; there was 100% agreement for amoxicillin a other antibiotics showed 90% to 95% accuracy. Disk diffusion is cheaper than E-test (approximately 2.6 cents vs. 2.60 US dollars), is easy to perform, and is a reliable method for testing H. pylori susceptibility to antimicrobial agents in the clinical microbiology laboratory.

UreC PCR based diagnosis of Helicobacter pylori infection and detection of cag A gene in gastric biopsies

Polymerase chain reaction assay using ureC gene specific primers for the detection of Helicobacter pylori in gastric biopsy specimens from 116 dyspeptic patients was compared with other routine invasive diagnostic methods (culture, rapid urease test [RUT] and histology). In parallel, gastric biospy specimens from 54 patients and their corresponding Helicobacter pylori isolates were subjected to PCR with cagA targeting primers using standard protocols. Helicobacter pylori were detected in 53%, 43%, 48% and 50% of patients by PCR, RUT, culture and histological examination respectively. Based on histology and culture positive and at least three test positive result, 44 (37%), 46 (39%) and 26 (22%), and 56 (48%), 52 (44%) and 8 (6%) patients were classified as Helicobacter pylori positive, negative and indeterminate respectively. The sensitivity and specificity of PCR assay was the highest-95% and 100% when compared with both culture and histology positive, and at least any three positive results respectively. The result of cagA positivity in 54 gastric biopsy specimens and their corresponding Helicobacter pylori isolates were identical; 18 of 20 (90%) duodenal ulcer patients and 23 of 28 (82%) patients with chronic gastritis and 2 (40%) of 5 patients with portal hypertension and one gastric biopsy specimens from gastric cancer patients were found to be cagA positive. PCR-based method to detect Helicobacter pylori and the virulence gene cag A directly from gastric biopsy specimens appears to be promising and can curtail the lengthy process of culture-based approaches. The procedure proved to be rapid and reliable and could be utilized for diagnostic purposes.

Comparison of various conventional methods with a polymerase chain reaction assay for detecting methicillin-resistant & susceptible Staphylococcus aureus strains

BACKGROUND & OBJECTIVES

Methicillin-resistant Staphylococcus aureus (MRSA), a major nosocomial pathogen world-wide, is often difficult to detect due to the heterogeneous nature of expression of oxacillin resistance. In the present study, various conventional methods were compared with polymerase chain reaction on 106 clinical isolates of Staph. aureus for detection of oxacillin resistance.

METHODS

A total of 106 clinical isolates of Staph. aureus were tested for oxacillin resistance by disc diffusion, screen agar plates (3 micrograms and 6 micrograms/ml of oxacillin), oxacillin broth (3 micrograms/ml) and mecA based PCR.

RESULTS

PCR detected mecA gene amplified product of 604 bp in 57 strains. Disc diffusion failed to detect 7 mecA positive strains but identified 5 mecA negative strains as oxacillin resistant. Screen agar 3 micrograms, screen agar 6 micrograms and oxacillin broth 3 micrograms detected 55, 53 and 55 respectively of the 57 mecA positive strains; however, they also falsely identified 5, 3 and 3 strains of mecA negative strains respectively as oxacillin resistant. The sensitivity, specificity and accuracy of disc diffusion, 3 micrograms screen agar, 6 micrograms screen agar and 3 micrograms oxacillin broth against PCR as gold standard were as follows: 87.7, 89.9 and 88.7 per cent; 96.5, 89.8 and 93.4 per cent; 93.0, 93.9 and 93.4 per cent; 96.5, 93.9 and 95.3 per cent respectively.

INTERPRETATION & CONCLUSIONS

The present study demonstrated that disc diffusion test was least reliable and 3 micrograms broth had the highest sensitivity and specificity when compared with PCR for detection of oxacillin resistance. Because of variations among the methods, a combination of tests should be used for the accurate detection of MRSA till new guidelines by an appropriate body are formulated.

A study on physiological changes in certain psychosomatic disorders with reference to cortisol, blood glucose and lipid profile

Plasma cortisol, blood glucose, serum lipids and lipoproteins were estimated in diseased human subjects and normal control volunteers. Serum triglyceride (Tg) total cholesterol (Tc) and cholesterol content of very low density lipoprotein (VLDLc), low density lipoprotein (LDLc) and high density lipoprotein (HDLc) were assayed under lipid profile. Clinical investigations were carried out on 115 subjects which involved 30 control, 25 irritable bowel syndrome (IBS), 30 bronchial asthma and 30 rheumatoid arthritis patients. The results of this preliminary study showed a significant change in the levels of all the biochemical parameters in diseased subjects in comparison with controls. Increased levels of atherogenic lipids, Tg, VLDLc and LDLc were found in rheumatoid arthritis subjects. This suggests that arthritis subjects are relatively at higher risk of developing coronary heart disease. Furthermore hypercholesterolemia may aggravate the risk condition in arthritis patients by artereosclerosis. The significant elevation in the levels of plasma cortisol reveals the fact that rheumatoid arthritis is a stabilized and chronic psychosomatic disorder, since, homeostatic competence is disrupted following decline in the tendency of stress-response to return to normalcy.

A study on physiological changes in essential hypertension and rheumatoid arthritis with reference to the levels of cortisol, blood glucose, triglycerides and cholesterol

The levels of plasma cortisol, blood glucose, serum triglycerides (TG) and total cholesterol (TC) were estimated in 175 human subjects (50 normal controls, 65 having essential hypertension and 60 suffering from rheumatoid arthritis. The results showed a significant elevation in the levels of plasma cortisol and blood glucose in both the stressed clinical groups with respect to controls. Increased levels of atherogenic lipids (TG and TC) were also observed in diseased group. However, in rheumatoid arthritis the biochemical changes were comparatively more pronounced than in hypertensives. The findings in vitro reveal that rheumatoid arthritis is a relatively more chronic and late onset disorder, since the functional performance of hypothalamo-pituitary-adrenocortical (HPA) axis declines with chronicity and the efficacy of adrenocortical response to return to normalcy becomes impaired.

Modulation and recovery of immune response of BALB/c mice to Shigella dysenteriae antigens after cyclophosphamide treatment

We have analysed the suppressive effect of cyclophosphamide, when given in vivo, on the antibody response of BALB/c mice against Shigella dysenteriae antigens using ELISA and immunoblot. Out of various protocols tried, it was found that co-injection of cyclophosphamide at 150 mg/kg bodyweight, i.p., at the time of antigen administration and then after a lapse of 24 h during both primary and secondary immunizations, was the most effective in suppressing antibody response of mice. Analysis of sera by ELISA demonstrated the presence of some antibodies to S. dysenteriae antigens after secondary immunization, but immunoblot analysis using the same sera revealed complete suppression of antibody response. Animals whose antibody response was almost completely suppressed after two immunizations with co-injection of cyclophosphamide, when immunized again after the lapse of 14 days from the date of secondary immunization with Shigella antigens but without administration of cyclophosphamide, partially recovered their ability to respond to the same antigens. This protocol can now be used in mice to analyse the hierarchy of immunogenic epitopes present in a complex mixture of antigens.

Kinetics and mechanism of the oxidation of 1-propane thiol by 2,6-dichlorophenolindophenol in acidic medium

The kinetics of oxidation of 1-propanethiol by 2,6-dichlorophenolindophenol have been studied in acetone–water medium and in the presence of phosphate buffer. The principal reactants interact in a molar ratio of 2:1 forming disulphide and dihydroindophenol. The reaction follows second order kinetics in indophenol while the order is unity in thiol. The rate increases linearly on increasing [H+]. The rate of oxidation increases on increasing the ionic strength as well as the dielectric constant of the reaction system. The addition of reaction products has no effect on the rate. Activation parameters have been evaluated and a suitable mechanism consistent with kinetic data is suggested.