Chronic kidney disease associated cardiomyopathy: recent advances and future perspectives

PURPOSE OF REVIEW

Cardiomyopathy in chronic kidney disease (CKD) is a complex condition with multiple triggers and poor prognosis. This review provides an overview of recent advances in CKD-associated cardiomyopathy, with a focus on pathophysiology, newly discovered biomarkers and potential therapeutic targets.

RECENT FINDINGS

CKD is associated with a specific pattern of myocardial hypertrophy and fibrosis, resulting in diastolic and systolic dysfunction, and often triggered by nonatherosclerotic processes. Novel biomarkers, including amino-terminal type III procollagen peptide (PIIINP), carboxy-terminal type I procollagen peptide (PICP), FGF23, marinobufagenin, and several miRNAs, show promise for early detection and risk stratification. Treatment options for CKD-associated cardiomyopathy are limited. Sodium glucose cotransporter-2 inhibitors have been shown to reduce left ventricle hypertrophy and improve ejection fraction in individuals with diabetes and mild CKD, and are currently under investigation for more advanced stages of CKD. In hemodialysis patients calcimimetic etelcalcetide resulted in a significant reduction in left ventricular mass.

SUMMARY

CKD-associated cardiomyopathy is a common and severe complication in CKD. The identification of novel biomarkers may lead to future therapeutic targets. Randomized clinical trials in individuals with more advanced CKD would be well posed to expand treatment options for this debilitating condition.

Culturing the unculturables: strategies, challenges, and opportunities for gut microbiome study

Metagenome sequencing techniques revolutionized the field of gut microbiome study. However, it is equipped with experimental and computational biases, which affect the downstream analysis results. Also, live microbial strains are needed for a better understanding of host-microbial crosstalks and for designing next-generation treatment therapies based on probiotic strains and postbiotic molecules. Conventional culturing methodologies are insufficient to get the dark gut matter on the plate; therefore, there is an urgent need to propose novel culturing methods that can fill the limitations of metagenomics. The current work aims to provide a consolidated evaluation of the available methods for host-microbe interaction with an emphasis on in vitro culturing of gut microbes using organoids, gut on a chip, and gut bioreactor. Further, the knowledge of microbial crosstalk in the gut helps us to identify core microbiota, and key metabolites that will aid in designing culturing media and co-culturing systems for gut microbiome study. After the deeper mining of the current culturing methods, we recommend that 3D-printed intestinal cells in a multistage continuous flow reactor equipped with an extended organoid system might be a good practical choice for gut microbiota-based studies.

Proteomic, biochemical, histopathological, and elevated plus maze analysis reveals the gut damaging role of ketoprofen with Yersinia enterocolitica and altered behavior in Wistar rats

The long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) is known to damage the intestinal epithelial cells (IECs) that play numerous important roles, including nutrient absorption and barrier protection. In the current study, we determined the effect of ketoprofen on the rat gut when administered with Yersinia enterocolitica. On performing the label-free quantitation of the rat gut proteins, the expression of 494 proteins out of 1628 proteins was altered, which has a profound effect on NF-kB signaling pathway, immune system, dysbiosis, and gut injury. Further, the biochemical [enhanced malondialdehyde (MDA) & hepatic enzyme activities and reduced serotonin & antioxidants levels i.e., catalase (CAT) and superoxide dismutase (SOD)] and histopathological analysis suggested the significant damage in treated rats, compared to control rats. Lastly, the elevated plus maze (EPM) study confirmed high levels of anxiety in treated rats in comparison to the control group. Altogether, results suggest that the co-administration of ketoprofen with Y. enterocolitica damages gut, alters hepatic enzyme activities, and affects behavioral responses in the treated rats.

Lepidopteran insects: emerging model organisms to study infection by enteropathogens

The in vivo analysis of a pathogen is a critical step in gaining greater knowledge of pathogen biology and host-pathogen interactions. In the last two decades, there has been a notable rise in the number of studies on developing insects as a model for studying pathogens, which provides various benefits, such as ethical acceptability, relatively short life cycle, and cost-effective care and maintenance relative to routinely used rodent infection models. Furthermore, lepidopteran insects provide many advantages, such as easy handling and tissue extraction due to their large size relative to other invertebrate models, like Caenorhabditis elegans. Additionally, insects have an innate immune system that is highly analogous to vertebrates. In the present review, we discuss the components of the insect's larval immune system, which strengthens its usage as an alternative host, and present an updated overview of the research findings involving lepidopteran insects (Galleria mellonella, Manduca sexta, Bombyx mori, and Helicoverpa armigera) as infection models to study the virulence by enteropathogens due to the homology between insect and vertebrate gut.

Balancing reactive oxygen species generation by rebooting gut microbiota

Reactive oxygen species (ROS; free radical form O₂ ^•‾ , superoxide radical; OH^• , hydroxyl radical; ROO^• , peroxyl; RO^• , alkoxyl and non-radical form ¹ O₂ , singlet oxygen; H₂ O₂ , hydrogen peroxide) are inevitable companions of aerobic life with crucial role in gut health. But, overwhelming production of ROS can cause serious damage to biomolecules. In this review, we have discussed several sources of ROS production that can be beneficial or dangerous to the human gut. Microorganisms, organelles and enzymes play crucial role in ROS generation, where, NOX1 is the main intestinal enzyme, which produce ROS in the intestine epithelial cells. Previous studies have reported that probiotics play significant role in gut homeostasis by checking the ROS generation, maintaining the antioxidant level, immune system and barrier protection. With current knowledge, we have critically analyzed the available literature and presented the outcome in the form of bubble maps to suggest the probiotics that help in controlling the ROS-specific intestinal diseases, such as inflammatory bowel disease (IBD) and colon cancer. Finally, it has been concluded that rebooting of the gut microbiota with probiotics, postbiotics or fecal microbiota transplantation (FMT) can have crucial implications in the structuring of gut communities for the personalized management of the gastrointestinal (GI) diseases.

Yersinia enterocolitica and Lactobacillus fermentum induces differential cellular and behavioral responses during diclofenac biotransformation in rat gut

Non-steroidal anti-inflammatory drugs (NSAIDs) can induce small-intestinal injuries through inhibition of prostaglandin synthesis. Gut has an important role in building and maintaining the barriers to avoid the luminal gut microbiota from invading the host, and cytoskeleton plays a crucial role in the maintenance of cellular barrier. The recent advances suggest a bi-directional interaction between the drugs and gut microbiota, where gut microbes can metabolize the drugs, and in response drugs can alter the composition of gut microbiota. In the present study, we evaluated the effect of diclofenac on rat gut, when co-administrated with either Yersinia enterocolitica strain 8081 (an enteropathogen) or Lactobacillus fermentum strain 9338 (a probiotic). The LC-MS/MS based label-free quantitation of rat gut proteins revealed 51.38% up-regulated, 48.62% down-regulated in diclofenac-Y. enterocolitica strain 8081 (D*Y), and 74.31% up-regulated, 25.69% down-regulated in diclofenac-L. fermentum strain 9338 (D*L) experiments. The identified proteins belonged to cytoskeleton, metabolism, heme biosynthesis and binding, stress response, apoptosis and redox homeostasis, immune and inflammatory response, and detoxification and antioxidant defence. Further, the histopathological and biochemical analysis indicated more pronounced histological alterations and oxidative stress (enhanced malonaldehyde and altered antioxidant levels) in D*Y rats than D*L rats, compared to control rats. Elevated plus maze (EPM) test performed to determine the behavioral changes, suggested increased anxiety in D*Y rats than D*L rats, compared to control rats. These results together suggest the differential role of either bacterium in biotransformation of diclofenac, and inflammatory and cellular redox response.

Infected insect gut reveals differentially expressed proteins for cellular redox, metal resistance and secretion system in Yersinia enterocolitica-Helicoverpa armigera pathogenic model

OBJECTIVE

Mouse infection models are frequently used to study the host-pathogen interaction studies. However, due to several constraints, there is an urgent need for a simple, rapid, easy to handle, inexpensive, and ethically acceptable in vivo model system for studying the virulence of enteropathogens. Thus, the present study was performed to develop the larvae of Helicoverpa armigera as a rapid-inexpensive in vivo model system to evaluate the effect of Yersinia enterocolitica strain 8081 on its midgut via a label-free proteomic approach.

RESULTS

Helicoverpa armigera larvae fed with Yersinia enterocolitica strain 8081 manifested significant reduction in body weight and damage in midgut. On performing label-free proteomic study, secretory systems, putative hemolysin, and two-component system emerged as the main pathogenic proteins. Further, proteome comparison between control and Yersinia added diet-fed (YADF) insects revealed altered cytoskeletal proteins in response to increased melanization (via a prophenoloxidase cascade) and free radical generation. In concurrence, FTIR-spectroscopy, and histopathological and biochemical analysis confirmed gut damage in YADF insects. Finally, the proteome data suggests that the mechanism of infection and the host response in Y. enterocolitica-H. armigera system mimics Yersinia-mammalian gut interactions.

CONCLUSIONS

All data from current study collectively suggest that H. armigera larva can be considered as a potential in vivo model system for studying the enteropathogenic infection by Y. enterocolitica strain 8081.

Inflammatory bowel disease: tri-directional relationship between microbiota, immune system and intestinal epithelium

Human gut microbiota contributes to host nutrition and metabolism, sustains intestinal cell proliferation and differentiation, and modulates host immune system. The alterations in their composition lead to severe gut disorders, including inflammatory bowel disease (IBD) or inflammatory bowel syndrome (IBS). IBD including ulcerative colitis (UC) and Crohn's disease (CD) are gamut of chronic inflammatory disorders of gut, mediated by complex interrelations among genetic, environmental, and internal factors. IBD has debateable aetiology, however in recent years, exploring the central role of a tri-directional relationship between gut microbiota, mucosal immune system, and intestinal epithelium in pathogenesis is getting the most attention. Increasing incidences and early onset explains the exponential rise in IBD burden on health-care systems. Industrialization, hypersensitivity to allergens, lifestyle, hygiene hypothesis, loss of intestinal worms, and gut microbial composition, explains this shifted rise. Hitherto, the interventions modulating gut microbiota composition, microfluidics-based in vitro gastrointestinal models, non-allergic functional foods, nutraceuticals, and faecal microbiota transplantation (FMT) from healthy donors are some of the futuristic approaches for the disease management.

Stabilization-destabilization and redox properties of laccases from medicinal mushroom Ganoderma lucidum and human pathogen Yersinia enterocolitica

Laccases or benzenediol oxygen oxidoreductases (EC 1.10.3.2) are polyphenol multicopper oxidases that are known for their structural and functional diversity in various life forms. In the present study, the molecular and physico-chemical properties (redox-potential and secondary structures) of fungal laccase isozymes (FLIs) isolated from a medicinal mushroom Ganoderma lucidum were analyzed and compared with those of the recombinant bacterial laccases (rLac) obtained from different Yersinia enterocolitica strains. It was revealed that the FLIs contained His-Cys-His as the most conserved residue in its domain I Cu site, while the fourth and fifth residues were variable (Ile, Leu, or Phe). Evidently, the cyclic voltammetric measurements of Glac L2 at Type 1 Cu site revealed greater E° for ABTS/ABTS⁺ (0.312 V) and ABTS⁺/ABTS²⁺ (0.773 V) compared to the E° of rLac. Furthermore, circular dichroism-based conformational analysis revealed structural stability of the FLIs at acidic pH (3.0) and low temperature (<30 °C), while the isozymes were destabilized at neutral pH (7.0) and high-temperature conditions (>70 °C). The zymographic studies further confirmed the functional inactivation of FLIs at high temperatures (≥70 °C), predominantly due to domain unfolding. These findings provide novel insight into the evolution of the catalytic efficiency and redox properties of the FLIs, contributing to the existing knowledge regarding stress responses, metabolite production, and the biotechnological utilization of metabolites.

Immunological co-ordination between gut and lungs in SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved into a major pandemic called coronavirus disease 2019 (COVID-19) that has created unprecedented global health emergencies, and emerged as a serious threat due to its strong ability for human-to-human transmission. The reports indicate the ability of SARS-CoV-2 to affect almost any organ due to the presence of a receptor known as angiotensin converting enzyme 2 (ACE2) across the body. ACE2 receptor is majorly expressed in the brush border of gut enterocytes along with the ciliated cells and alveolar epithelial type II cells in the lungs. The amino acid transport function of ACE2 has been linked to gut microbial ecology in gastrointestinal (GI) tract, thereby suggesting that COVID-19 may, to some level, be linked to the enteric microbiota. The significant number of COVID-19 patients shows extra-pulmonary symptoms in the GI tract. Many subsequent studies revealed viral RNA of SARS-CoV-2 in fecal samples of COVID-19 patients. This presents a new challenge in the diagnosis and control of COVID-19 infection with a caution for proper sanitation and hygiene. Here, we aim to discuss the immunological co-ordination between gut and lungs that facilitates SARS-CoV-2 to infect and multiply in the inflammatory bowel disease (IBD) and non-IBD patients.

Gut-organ axis: a microbial outreach and networking

Human gut microbiota (GM) includes a complex and dynamic population of microorganisms that are crucial for well-being and survival of the organism. It has been reported as diverse and relatively stable with shared core microbiota, including Bacteroidetes and Firmicutes as the major dominants. They are the key regulators of body homeostasis, involving both intestinal and extra-intestinal effects by influencing many physiological functions such as metabolism, maintenance of barrier homeostasis, inflammation and hematopoiesis. Any alteration in GM community structures not only trigger gut disorders but also influence other organs and cause associated diseases. In recent past, the GM has been defined as a 'vital organ' with its involvement with other organs; thus, establishing a link or a bi- or multidirectional communication axis between the organs via neural, endocrine, immune, humoral and metabolic pathways. Alterations in GM have been linked to several diseases known to humans; although the exact interaction mechanism between the gut and the organs is yet to be defined. In this review, the bidirectional relationship between the gut and the vital human organs was envisaged and discussed under several headings. Furthermore, several disease symptoms were also revisited to redefine the communication network between the gut microbes and the associated organs.

A practical criterion for focusing of unstained cell samples using a digital holographic microscope

Digital holographic microscopy (DHM) is an important technique that may be used for quantitative phase imaging of unstained biological cell samples. Since the DHM technology is not commonly used in clinics or bioscience research labs, at present there is no well-accepted focusing criterion for unstained samples that users can follow while recording image plane digital holograms of cells. The usual sharpness metrics that are useful for auto-focusing of stained cells do not work well for unstained cells as there is no amplitude contrast. In this work, we report a practical method for estimating the best focus plane for unstained cells in the digital hologram domain. The method is based on an interesting observation that for the best focus plane the fringe pattern associated with individual unstained cells predominantly shows phase modulation effect in the form of bending of fringes and minimal amplitude modulation. This criterion when applied to unstained red blood cells shows that the central dip in the doughnut-like phase profile of cells is maximal in this plane. The proposed methodology is helpful for standardizing the usage of DHM technology across different users and application development efforts. LAY DESCRIPTION: Digital holographic microscopy (DHM) is slowly but steadily becoming an important microscopy modality and gaining acceptability for basic bio-science research as well as clinical usage. One of the important features of DHM is that it allows users to perform quantitative imaging of unstained transparent cells. Instead of using dyes or fluorescent labelling, DHM systems use quantitative phase as a contrast mechanism which depends on the natural refractive index variation within the cell samples. Since minimal wet lab processing is required in order to image cell samples with a DHM, cells can be imaged in their natural state. While DHM is gaining popularity among users, the imaging protocols across the labs or users need to be standardized in order to make sure that the same quantitative phase parameters are used for tasks such as quantitative phased based cell classification. One of the important operational tasks for any microscopy work is to focus the sample under study. While focusing comes naturally to users of brightfield microscopes based on image contrast, the focusing is not straightforward when samples are unstained so that they do not offer any amplitude contrast. When performing quantitative phase imaging, defocus can actually change the phase profile of the cell due to near-zone (Fresnel) diffraction effects. So unless a standardized focusing methodology is used, it will be difficult for multiple DHM users (potentially at different sites) to agree on quantitative results out of their phase images. DHM literature has prior works which perform numerical focusing of recovered complex wave-field in the hologram plane to find the best focus plane. However such methods are not user friendly and do not allow user the same focusing experience as in a brightfield microscope. The numerical focusing is therefore a reasonably good method for an optics researcher but not necessarily so for a microscopy technician looking at cell samples with a DHM system in a clinical setting. The present work provides a simple focusing criterion for unstained samples that works directly in the hologram domain. The technique is based on an interesting observation that the when an unstained cell sample is in the best-focus plane, its corresponding hologram (or fringe pattern) predominantly shows phase modulation manifested by bending of fringes at the location of the cell. This criterion can be converted into a simple numerical method as we have used to find the best-focus plane using a stack of through focus holograms. We believe that the technique can be used manually by visually observing the holograms or can be converted to an auto-focus algorithm for a motorized DHM system.

Molecular modeling and MD-simulation studies: Fast and reliable tool to study the role of low-redox bacterial laccases in the decolorization of various commercial dyes

Synthetic dyes are toxic and carcinogenic in nature, which also causes environmental pollution. The present study was aimed to decolorize various commercial dyes using purified recombinant bacterial laccases. Laccase gene from Yersinia enterocolitica strain 8081 (yacK), Y. enterocolitica strain 7 (yacK) and Bacillus pumilus DSKK1 was cloned in vector pET28a and overproduced in host Escherichia coli BL21. The high yield of recombinant laccase protein resulted in the formation of inclusion bodies, which were further solubilized, refolded, and purified. The purified recombinant laccases were alkali-tolerant and thermostable, with pH optima at 7-8, temperature optima at 60-70 °C and low redox potential. For in silico studies, laccase protein models of B. pumilus DSKK1, Y. enterocolitica strain 7 and Y. enterocolitica strain 8081 were docked with commercial dyes. This is the first and foremost study where the stability of docked complexes of pathogenic and non-pathogenic microorganism has been explored via molecular dynamics (MD) simulations using Gromacs version 4.5.5 with the gromos96 43a force field. Finally, the in silico results were validated experimentally and it was found that purified laccases from B. pumilus DSKK1 and Y. enterocolitica strain 7 efficiently decolorized rose bengal (90.4%), malachite green (77.7%), and congo red (74.5%) dyes.

Differential promoter methylation of DAZL gene in bulls with varying seminal parameters

In India, cross-breeding of indigenous cattle with exotic cattle such as Holstein Friesian and Jersey has been going on since last four decades to improve milk production. Although it has led to increased milk yield, the subfertility in male cross-bred progeny has remained a significant problem. Epigenetic modifications (DNA methylation, histone modifications and chromatin remodelling) are regarded as key players influencing gene expression. DAZL gene plays an important role in germline development and gametogenesis. The methylation and mRNA expression level of this gene have been significantly negatively correlated in the testes of cattle-yak hybrids and their parents. This study analysed the methylation profile of DAZL gene promoter in bull spermatozoa in an attempt to speculate its role in cross-bred cattle subfertility. Semen samples from Sahiwal, Holstein Friesian and Frieswal bulls (Sahiwal X Holstein Friesian) with varying semen motility parameters were collected, and DNA was isolated. Methylation-specific primers were used to amplify part of promoter and exon 1 of DAZL gene using bisulphite-converted DNA. The amplified products were sequenced after cloning in pTZ57R/T vector. Sequence analysis revealed significantly higher DNA methylation of DAZL gene in Frieswal bulls with poor motility (28.26%) as compared to medium (15.21%) and high motility phenotype (6.52%). In pure-bred counterparts, Sahiwal and Holstein Friesian, epigenetic marks were more in the former (15.21%) than the latter (4.34%), but in both cases, the values were lower as compared to the poor motility Frieswal bulls. This suggests that differential hypermethylation of the CpG islands could possibly influence reproductive parameters in bovines.

MDCT of hand and wrist infections: emphasis on compartmental anatomy

Hand and wrist infections can present with a spectrum of manifestations ranging from cellulitis to deep-space collections. The various infectious processes can be categorised as superficial or deep infections based on their respective locations relative to the tendons. Superficial hand infections are located superficial to the tendons and are comprised of cellulitis, lymphangitis, paronychia, pulp-space infections, herpetic whitlow, and include volar as well as dorsal subcutaneous abscesses. Deep hand infections are located deep to the tendon sheaths and include synovial space infections, such as infectious tenosynovitis, deep fascial space infections, septic arthritis, necrotising fasciitis, and osteomyelitis. Knowledge of hand and wrist compartmental anatomy is essential for the accurate diagnosis and management of hand infections. Although early and superficial infections of the hand may respond to non-surgical management, most hand infections are surgical emergencies. Multidetector computed tomography (MDCT), with its muliplanar reformation (MPR) and three-dimensional (3D) capabilities, is a powerful tool in the emergency setting for the evaluation of acute hand and wrist pathology. The clinical and imaging features of hand and wrist infections as evident on MDCT will be reviewed with emphasis on contiguous and closed synovial and deep fascial spaces. Knowledge of hand compartmental anatomy enables accurate characterisation of the infectious process and localise the extent of disease in the acute setting.

Evidence of positive selection and concerted evolution in the rapidly evolving PRDM9 zinc finger domain in goats and sheep

Meiotic recombination contributes to augmentation of genetic diversity, exclusion of deleterious alleles and proper segregation of chromatids. PRDM9 has been identified as the gene responsible for specifying the location of recombination hotspots during meiosis and is also the only known vertebrate gene associated with reproductive isolation between species. PRDM9 encodes a protein with a highly variable zinc finger (ZF) domain that varies between as well as within species. In the present study, the ZF domain of PRDM9 on chromosome 1 was characterized for the first time in 15 goat breeds and 25 sheep breeds of India. A remarkable variation in the number and sequence of ZF domains was observed. The number of ZF repeats in the ZF array varied from eight to 12 yielding five homozygous and 10 heterozygous genotypes. The number of different ZF domains was 84 and 52 producing 36 and 26 unique alleles in goats and sheep respectively. The posterior mean of dN/dS or omega values were calculated using the codeml tool of pamlx to identify amino acids that are evolving positively in goats and sheep, as positions -1, +3 and +6 in the ZF domain have been reported to experience strong positive selection across different lineages. Our study identified sites -5, -1, +3, +4 and +6 to be experiencing positive selection. Small ruminant zinc fingers were also found to be evolving under concerted evolution. Our results demonstrate the existence of a vast diversity of PRDM9 in goats and sheep, which is in concert with reports in many metazoans.

Description and developmental biology of the predatory diplogastrid Acrostichus nudicapitatus (Steiner, 1914) Massey, 1962 (Nematoda: Rhabditida)

Acrostichus nudicapitatus (Steiner, 1914) Massey, 1962 is redescribed and illustrated along with observations on its developmental biology. Most morphometrics of the present population agree well with those of A. nudicapitatus (Steiner, 1914) Massey, 1962. The largely oviparous females of A. nudicapitatus lay eggs in single-celled or two-celled stage, 1.5 – 2 h after fertilization. In cultured females, the uterine tract was observed to accommodate occasionally as many as 4 – 6 eggs. The eggs are smooth-shelled, oval in shape measuring 45 – 48 x 23 – 26 μm in dimension. The pole of entry of sperm marks the posterior end of the developing embryo. The embryonation time has been recorded to be 20 – 25 h at 25 ± 2 °C. The first moult occurs inside the egg and the juvenile hatches as second stage juvenile. The gonad development follows the trends found in most rhabditids, however, three prime cells of the 12 vulval precursor cells have been observed to be involved in vulva formation.

Exon skipping creates novel splice variants of DMC1 gene in ruminants

Disrupted meiotic cDNA1 (DMC1) recombinase plays a pivotal role in homology search and strand exchange reactions during meiotic homologous recombination. In the present study, full length coding sequence of DMC1 gene was sequence characterized for the first time from four ruminant species (cattle, buffalo, sheep and goat) and phylogenetic relationship of ruminant DMC1 with other eukaryotes was analyzed. DMC1 gene encodes a putative protein of 340 amino acids in cattle, sheep and buffalo and 341 amino acids in goat. A high degree of evolutionary conservation at both nucleotide and amino acid level was observed for the four ruminant orthologs. In cattle and sheep, novel alternatively spliced mRNAs with skipping of exons 7 and 8 (Transcript variant 1, TV1) were isolated in addition to the full length (FL) transcript. Novel transcript variants with partial skipping of exon 7 and complete skipping of exon 8 (Transcript variant 2, TV2) were found in sheep and goat. The presence of these variants was validated by amplifying cDNA isolated from testis tissue of ruminants using two oligonucleotides flanking the deleted region. To accurately estimate their relative proportions, real-time PCR was performed using primers specific for each variant. Expression level of DMC1-FL was significantly higher than that of TV1 in cattle and TV2 in goat (P < 0.05). Relative ratio for expression of DMC1-FL: TV1: TV2 in sheep was 6.78: 1.43: 1. In-silico analysis revealed presence of splice variants of DMC1 gene across other mammalian species underpinning the role of alternative splicing in functional innovation.

Association of mucoid degeneration of anterior cruciate ligament with knee meniscal and cartilage damage

OBJECTIVE

To assess the prevalence of anterior cruciate ligament (ACL) mucoid degeneration in patients referred for routine knee magnetic resonance (MR) imaging, and its association with age and structural joint damage.

METHOD

Four independent radiologists assessed 413 consecutive knee MR examinations for the presence of a normal or ruptured ACL, or ACL mucoid degeneration. Knees with ACL mucoid degeneration were frequency matched by age, sex, and MR field strength with consecutive control knees with a normal ACL (1:2 ratio). Differences in meniscal and cartilage damage of the tibiofemoral compartments, as determined by the Whole-Organ MR Imaging Score (WORMS) system, were compared by Mann-Whitney U tests. Multivariable logistic regression analysis identified the association of ACL mucoid degeneration with severe MTFC cartilage damage (WORMS≥5).

RESULTS

Patients with ACL mucoid degeneration (n = 36; 36% males; median age 55.5 years, range: 26-81) were older than patients with a normal (P < 0.001) or ruptured ACL (P < 0.001), without sex predilection (P = 0.76), and were more frequently diagnosed at 3 T (12%) compared to 1.5 T (2%). Knees with ACL mucoid degeneration had statistically significantly more medial meniscal (P < 0.001) and central and posterior medial tibiofemoral compartment (MTFC) cartilage (P < 0.001) damage compared with control knees (n = 72), but there were no differences in patients ≤50 years (P = 0.09 and 0.32, respectively). In multivariable logistic regression, severe MTFC cartilage damage (WORMS≥5) was significantly associated with ACL mucoid degeneration (odds ratio 4.09, 95% confidence interval 1.29-12.94, P = 0.016).

CONCLUSION

There is a strong association between ACL mucoid degeneration and cartilage damage in the central and posterior MTFC, especially in patients >50 years.

Novel polymorphism of AA-NAT gene in Indian goat breeds differing in reproductive traits

This is the first description of the polymorphisms of arylalkylamine-N-acetyltransferase (AA-NAT) gene in Indian goats with different reproductive traits (twinning percentage and age of sexual maturity). Based on the important role of AA-NAT in reproduction, it is considered as a possible candidate gene for this trait. Two novel synonymous SNPs, C825T (exon2) and C1249T (exon3) were identified. All three possible genotypes (CC, CT and TT) were identified for C825T mutation whereas two genotypes were observed (CC and CT) for C1249T mutation. SNPs C825T and C1249T changed recognition site of restriction enzyme BtsCI (GGA T G) and AciI (C C GC) and thus can be genotyped by the relatively simple and cost effective technique of PCR-RFLP for establishing further association with reproductive traits. Present results add to the meager existing knowledge and extend the spectrum of genetic variation of caprine candidate genes of reproductive traits, which is another step towards improvement of goat genetic resources and breeding.

Gradient-echo in-phase and opposed-phase chemical shift imaging: role in evaluating bone marrow

Chemical shift imaging (CSI) provides valuable information for assessing the bone marrow, while adding little to total examination time. In this article, we review the uses of CSI for evaluating bone marrow abnormalities. CSI can be used for differentiating marrow-replacing lesions from a range of non-marrow-replacing processes, although the sequence is associated with technical limitations and pitfalls. Particularly at 3 T, susceptibility artefacts are prevalent, and optimal technical parameters must be implemented with appropriate choices for echo times.

High expression of human chorionic gonadotrophin beta-subunit using a synthetic vaccinia virus promoter

We have constructed a recombinant vaccinia virus to express the beta-subunit of human chorionic gonadotrophin (betahCG), a secretory glycoprotein that is used as an antigen for a contraceptive vaccine. The cDNA encoding the subunit was cloned under the control of a synthetic promoter that could be recognised by a vaccinia virus RNA polymerase to direct transcription. The peak expression level of betahCG directed by a late synthetic promoter (Psyn) was 11.5 microg/ml, a level that was at least sixfold higher than that directed by the p7.5 early/late promoter. The expressed protein was correctly processed post-translationally such that it attained a conformation with correctly folded discontinuous epitope(s) similar to that seen in native betahCG.

Enhanced immunogenicity of a contraceptive vaccine using diverse synthetic carriers with permissible adjuvant

A vaccine directed against human chorionic gonadotropin (hCG) has previously undergone clinical testing demonstrating the feasibility of the approach in preventing pregnancy in women. Some individuals, however, did not respond adequately despite employing highly immunogenic bacterial toxoids as carriers. We investigated the potential of three promiscuous pathogen-derived Th peptides as carriers, employing alum as the adjuvant. While conjugation with each peptide improved the antibody response against hCG in mice of different haplotypes, immunisation with a combination of these peptide-conjugates generated anti-hCG responses higher than those achieved with the individual peptides or tetanus toxoid (TT). Antibodies were of high affinity and capable of neutralising the bioactivity of hCG but were devoid of anti-peptide reactivity. These results have implication for the design of hCG vaccine with improved immunogenicity for diverse population.

Meningococcal meningitis outbreak control strategies

Meningococcal meningitis has been occurring worldwide in both endemic and epidemic forms. Serogroup A accounts for majority of cases of epidemic as well as endemic Meningococcal meningitis in developing nations, whereas group C and group B causes epidemic and endemic meningococcal meningitis in developed countries. Person to person spread of N. meningitides generally occurs through inhalation of droplets of infected nasopharyngeal secretions by direct or indirect oral contact. Incubation period varies from 2 to 10 days. N. meningitides typically causes acute infective illness characterized by sequential development of upper respiratory tract infection, meningococcemia, meningitis and focal neurological deficit. Over 90 per cent cases of adult meningococcal infections have cerebrospinal meningitis, whereas in children prevalence of meningitis is much lower (50 per cent). Acute meningitis manifests with fever, severe headache, vomiting and neck stiffness. Presentations may be non-specific in infants, elderly and in patients with fulminant meningococcemia. Diagnosis is confirmed with cerebrospinal fluid analysis. Overall mortality due to meningitis is usually around 10 per cent. In meningococcal septicemia, the case fatality rate may exceed 50 per cent. Preventive strategies include vaccination, chemoprophylaxis and early detection and treatment. Mass vaccination campaign, if appropriately carried out, has been documented to halt an epidemic of meningococcal disease due to serogroup A or C. In the present review we have discussed the available evidence with regards to prevention at primary, secondary and tertiary level. Public health approach to an outbreak of meningococcal meningitis in a community or an organization is also outlined.

Humoral hyporesponsiveness to a conjugate contraceptive vaccine and its bypass by diverse carriers using permissible adjuvant

A contraceptive vaccine directed against human chorionic gonadotropin (hCG) has previously undergone clinical testing that demonstrated the feasibility of the approach in preventing pregnancy in women. Some immunized volunteers however, did not respond with an adequate anti-hCG antibody response despite employing highly immunogenic bacterial toxoids as carriers. Since there is some evidence that T cell responses to a complex protein typically focus on a few immunodominant epitopes, we investigated the responsiveness to hCG in mice of different haplotypes using the protein carrier diphtheria toxoid (DT). Our data showed a differential carrier effect of DT. With the aim of making a more potent immunogen employing promiscuous pathogen-derived Th peptides as carriers, peptide:antigen stoichiometric ratios were optimized. When tested individually using alum as the adjuvant, three such peptide conjugates improved the anti-hCG response, though not consistently to levels higher than the DT conjugate. Immunization with a combination of these synthetic epitopes generated anti-hCG responses higher than those achieved with DT or with the individual peptides. Antibodies were of high affinity and capable of neutralizing the bioactivity of hCG, but were devoid of anti-peptide reactivity. These results support our view that differential hyporesponsiveness in a diverse population may arise from inadequate carrier effect and that it can be overcome by use of pathogen-derived broadly reactive non-B Th epitopes employing only alum, a permissible adjuvant.

Plasma platelet aggregating factor and platelet aggregation studies in pre-eclampsia

OBJECTIVE

A plasma platelet aggregation factor (PAF) has been implicated in the pathogenesis of platelet activation in thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). Similar mechanism may be operative in pre-eclampsia.

METHODS

Coagulation profile and detailed in vitro platelet aggregation with various agonists were studied. PAF was demonstrated by spontaneous aggregation of normal platelets with test plasma. Non-parametric Wilcoxon's rank sum test and Krauskal Wally's one way analysis of variance were applied.

RESULT

Twenty-two pre-eclamptic patients and 20 normal pregnant controls were studied. Anti-thrombin III levels were within normal range and fibrin degradation products were only border line raised ( > 10 < 40 micrograms/ml) in 14 (65.4%) patients. In vitro platelet aggregation was abnormal in 17 (77.2%) patients. PAF was demonstrable in 10 of 22 (45.5%) patients.

CONCLUSION

Platelet aggregation studies indicated the presence of both activated (hyperaggregable) as well as exhausted (hypoaggregable) platelets in circulation. PAF demonstrable in 45.4% pre-eclampsia patients would suggest its role in the pathogenetic mechanism of platelet activation in this disease.

Vinblastine and danazol therapy in steroid resistant childhood chronic idiopathic thrombocytopenic purpura

Various drugs such as vinca alkaloids, immunoglobulins and immunosuppressant drugs have been used with variable benefits in patients with chronic idiopathic thrombocytopenic purpura (CITP) refractory to steroid therapy. Vinblastine and danazol have been shown to decrease the expression of Fc (IgG) receptors on macrophages by different mechanisms. These two drugs were used in combination, with the presumption that they will have an additive effect in the treatment of CITP. Sixteen patients with CITP between 2 and 17 years of age, resistant to steroids, were treated with vinblastine given as an intravenous bolus dose at weekly intervals for 8 weeks (the induction phase), followed at monthly intervals for the next 6 months (the maintenance phase). Danazol was given daily in doses of 2-3 mg/kg body weight during both phases. Ten of the 16 (62.5%) patients had partial to complete response and 5 of these 10 patients had sustained remission after cessation of therapy. The initial outcome with the combination of these two drugs in CITP appears to be quite promising and requires further evaluation in a larger controlled study.

Hypofibrinogenaemia is the commonest congenital fibrinogen abnormality in north India

Congenital abnormalities of fibrinogen are rare disorders and all the cases reported in the literature indicate that the incidence of afibrinogenaemia is much higher than hypofibrinogenaemia. Of the total of 20 cases reported from other parts of India only one was congenital hypofibrinogenaemia. In contrast, the present study showed eight patients with congenital hypofibrinogenaemia among a total of nine unrelated North Indian patients with a fibrinogen abnormality. This disproportionately high incidence of hypofibrinogenaemia suggests the existence of a distinct genetic defect in the North Indian population.

Lipid profile in the first-degree relatives of patients with precocious coronary heart disease in Rohtak area (Northern India)

Twenty-five patients with precocious coronary heart disease (CHD) (aged forty years or less) and 82 first-degree relatives were studied for lipid profile. Eighty-eight age- and sex-matched controls were also studied. The mean serum cholesterol, triglycerides, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, and total cholesterol/high density lipoprotein cholesterol of patients and their first-degree relatives were significantly higher as compared with normal controls. High density lipoprotein cholesterol values were found to be almost identical in the patient group, their first-degree relatives, and normal controls. Hyperlipidemia was found in 68% of patients with CAD, of their first-degree relatives, and 24% of controls. Almost all lipid fractions in relatives of hyperlipidemic patients paralleled those of the patients suffering from CHD. Of 25 families studied, 16 had hyperlipidemia. In conclusion, it can be stated that there is a statistically significant hyperlipidemia in young patients with CHD that has a significant familial clustering, thus delineating a group of high-risk individuals (first-degree relatives of young coronary patients) for possible primary prevention of CHD. This familial clustering could be due to genetic or environmental factors; however, the relative contribution of these two factors requires further investigation.

Role of serum ferritin in assessment of disease activity in acute & chronic leukemia

Serum ferritin (SF) was estimated using double antibody sandwich ELISA in 83 patients of acute and chronic leukemia at various stages of the disease. In 35 patients of acute lymphoblastic leukemia (ALL) in remission, the SF levels fell significantly from 550.63 ng/ml at presentation to 319.56 ng/ml but remained significantly higher than the control values of 46.14 ng/ml. In 28 patients of acute myeloid leukemia (AML), the SF values at 775.0 ng/ml were much higher than those in ALL patients and showed no decline with remission. This pattern was also seen in patients of chronic myeloid leukemia in blast crisis (CML-BC) with SF levels of 804.03 ng/ml at presentation and 717.43 ng/ml at partial remission. The values of SF were lowest in patients of CML in chronic phase ranging from 271.5 ng/ml to 332.12 ng/ml and showed no relationship with variation in total leucocyte count. No correlation was found between SF values and various clinical and laboratory parameters such as age, sex, fever, organomegaly, haemoglobin and total leucocyte count. Thus, while there appeared to be a correlation between remission and SF values in ALL, no such correlation existed between the activity of the disease and SF in other types of leukemia.

Serum & tissue magnesium content in patients of aluminium phosphide poisoning and critical evaluation of high dose magnesium sulphate therapy in reducing mortality

Role of high dose magnesium sulphate therapy was evaluated in 50 patients of Aluminium Phosphide (AIP) poisoning. Simultaneously serum and RBC magnesium levels were studied in these patients at six different points within first 24 hours. In non-survivors magnesium content of various tissues (brain, stomach, kidneys, liver, lungs and heart) was also estimated. Magnesium estimation (tissue as well as serum) was done using atomic absorption spectrophotometer. No significant difference was found in dose related mortality rates in patients treated with and without magnesium sulphate. The immediate causes of death in these patients included intractable shock, shock coupled with arrhythmias and adult respiratory distress syndrome (ARDS). Serum as well as RBC magnesium content was within normal range at all the six points (0, 1, 3, 6, 12 and 24 hours after arrival in hospital). Tissue magnesium content of various organs (in non-survivors) was more (p < 0.01) compared to that of corresponding organs in controls (accidental deaths). No significant alterations were seen in other serum electrolytes (Na, K, Ca, PO4). The data confirmed that neither there was any evidence of hypomagnesemia in these patients nor magnesium sulphate therapy improved survival. Survival can be improved (to some extent) with continuous cardiac monitoring and use of appropriate anti-arrhythmic agents. However, imposition of stringent restrictions on the free supply of AIP and caging of tablets in plastic packs with holes and spikes may yield better results in preventing AIP poisoning rather than treating these patients.