Low oxygen levels caused by Noctiluca scintillans bloom kills corals in Gulf of Mannar, India

Coral reefs around the world are undergoing severe decline in the past few decades. Mass coral mortalities have predominantly been reported to be caused by coral bleaching or disease outbreaks. Temporary hypoxic conditions caused by algal blooms can trigger mass coral mortalities though are reported rarely. In this study in Gulf of Mannar (GoM), southeast India, we report a significant coral mortality caused by a bloom of the ciguatoxic dinoflagellate Noctiluca scintillans during September–October 2019. Dissolved oxygen levels declined below 2 mg l⁻¹ during the bloom causing temporary hypoxia and mortality (up to 71.23%) in the fast growing coral genera Acropora, Montipora and Pocillopora. Due to global climate change, more frequent and larger algal blooms are likely in the future. Hence, it is likely that shallow water coral reefs will be affected more frequently by episodic hypoxic conditions driven by algal blooms. More studies are, however, required to understand the mechanism of coral mortality due to algal blooms, impacts on community composition and the potential for subsequent recovery.

Marine debris - An emerging threat to the reef areas of Gulf of Mannar, India

Underwater survey was conducted to assess the accumulation and impact of marine debris in the reef areas of Gulf of Mannar in southeast India. A combination of roving diver technique and belt transect method was applied for the assessment, which was conducted during the period between February 2018 and March 2019. An estimated total reef area of 1152 m² has been affected by marine debris. Abandoned fishing nets were found to constitute the major portion of 43.17 ± 5.48% of the marine debris. Live corals were found to be dominant substrates for marine debris with 39.11%. The average prevalence of coral colonies in contact with marine debris was 3.28 ± 0.27%. Prevalence of corals in contact with debris was very high in genus Acropora with 8.23 ± 1.29% followed by Montipora with 4.63 ± 1.29% due to their complex growth form. Of the corals in contact with debris, 47.56% were fragmented and 34% were found with tissue loss.

Marine debris - An emerging threat to the reef areas of Gulf of Mannar, India

Underwater survey was conducted to assess the accumulation and impact of marine debris in the reef areas of Gulf of Mannar in southeast India. A combination of roving diver technique and belt transect method was applied for the assessment, which was conducted during the period between February 2018 and March 2019. An estimated total reef area of 1152 m² has been affected by marine debris. Abandoned fishing nets were found to constitute the major portion of 43.17 ± 5.48% of the marine debris. Live corals were found to be dominant substrates for marine debris with 39.11%. The average prevalence of coral colonies in contact with marine debris was 3.28 ± 0.27%. Prevalence of corals in contact with debris was very high in genus Acropora with 8.23 ± 1.29% followed by Montipora with 4.63 ± 1.29% due to their complex growth form. Of the corals in contact with debris, 47.56% were fragmented and 34% were found with tissue loss.

Seagrass restoration in Gulf of Mannar, Tamil Nadu, Southeast India: a viable management tool

Seagrass beds are important marine ecosystems that provide significant ecological services. The global decline of seagrass beds is becoming severe due to the increasing pressure of human-induced factors and changing climatic conditions. Restoration of seagrasses is an evolving science that started in 1939. In this study, we report a remarkably successful restoration activity carried out in the Gulf of Mannar (GoM), Southeast India. This is the first wide-scale effort in Indian waters. After the initial experimentation, manual transplantation of seagrass sprigs was carried out near Vaan and Koswari islands in GoM. Transplantation was performed with PVC quadrats and jute twines in areas of 800 m² in both the islands during February to May 2014. An increase from 16.4 ± 0.3 to 32.3 ± 0.6% in Vaan and from 15.1 ± 0.2 to 35.1 ± 0.9% in Koswari was observed in seagrass percentage cover during the period from June 2014 to May 2016. Area cover, shoot density, macrofaunal density and fish density increased at the restoration sites after the transplantation. Bottom trawling was found to be the most serious threat to the seagrass beds in these islands. This method of transplantation can be replicated in other areas of degraded seagrass in India to carry out wide-scale restoration of seagrasses.

Asymmetric pore occupancy in crystal structure of OmpF porin from Salmonella typhi

OmpF is a major general diffusion porin of Salmonella typhi, a Gram-negative bacterium, which is an obligatory human pathogen causing typhoid. The structure of S. typhi Ty21a OmpF (PDB Id: 3NSG) determined at 2.8 Å resolution by X-ray crystallography shows a 16-stranded β-barrel with three β-barrel monomers associated to form a trimer. The packing observed in S. typhi Ty21a rfOmpF crystals has not been observed earlier in other porin structures. The variations seen in the loop regions provide a starting point for using the S. typhi OmpF for structure-based multi-valent vaccine design. Along one side of the S. typhi Ty21a OmpF pore there exists a staircase arrangement of basic residues (20R, 60R, 62K, 65R, 77R, 130R and 16K), which also contribute, to the electrostatic potential in the pore. This structure suggests the presence of asymmetric electrostatics in the porin oligomer. Moreover, antibiotic translocation, permeability and reduced uptake in the case of mutants can be understood based on the structure paving the way for designing new antibiotics.

Refolding, purification and characterization of replication-initiator protein from soybean-infecting geminivirus

The replication-initiator protein (Rep) from a soybean-infecting geminivirus was overexpressed in E. coli as a fusion protein with maltose binding protein (MBP). In spite of the presence of the highly soluble MBP as the fusion partner, the overexpressed MBP-Rep fusion protein formed insoluble inclusion bodies. The protein was solubilized from the inclusion bodies and refolded. The refolded MBP-Rep protein was purified using ion exchange and amylose affinity chromatography. The activity of the purified MBP-Rep was assessed using an in vitro cleavage assay. Soluble and stable MBP-Rep protein was obtained in high abundance, providing the feasibility of large-scale production of active Rep protein for functional characterization and X-ray crystallographic structure determination.

Overexpression, refolding, and purification of the major immunodominant outer membrane porin OmpC from Salmonella typhi: characterization of refolded OmpC

The major immunodominant integral outer membrane protein C (OmpC) from Salmonella typhi Ty21a was overexpressed, without the signal peptide, in Escherichia coli. The protein aggregates as inclusion bodies (IBs) in the cytoplasm. OmpC from IBs was solubilized with 4 M urea and refolded. This involved rapid dilution of unfolded OmpC into a refolding buffer containing polyoxyethylene-9-lauryl ether (C(12)E(9)) and glycerol. The refolded OmpC (rfOmpC) was shown to be structurally similar to the native OmpC by SDS-PAGE, Western blotting, tryptic digestion, ultrafiltration, circular dichroism, and fluorescence spectroscopic techniques. Crystals of rfOmpC were obtained in preliminary crystallization trials. The rfOmpC also sets a stage for rational design by recombinant DNA technology for vaccine design and high resolution structure determination.

Huntingtin interacting protein 1 Is a clathrin coat binding protein required for differentiation of late spermatogenic progenitors

Huntingtin-interacting protein 1 (HIP1) interacts with huntingtin, the protein whose gene is mutated in Huntington's disease. In addition, a fusion between HIP1 and platelet-derived growth factor beta receptor causes chronic myelomonocytic leukemia. The HIP1 proteins, including HIP1 and HIP1-related (HIP1r), have an N-terminal polyphosphoinositide-interacting epsin N-terminal homology, domain, which is found in proteins involved in clathrin-mediated endocytosis. HIP1 and HIP1r also share a central leucine zipper and an actin binding TALIN homology domain. Here we show that HIP1, like HIP1r, colocalizes with clathrin coat components. We also show that HIP1 physically associates with clathrin and AP-2, the major components of the clathrin coat. To further understand the putative biological role(s) of HIP1, we have generated a targeted deletion of murine HIP1. HIP1(-/-) mice developed into adulthood, did not develop overt neurologic symptoms in the first year of life, and had normal peripheral blood counts. However, HIP1-deficient mice exhibited testicular degeneration with increased apoptosis of postmeiotic spermatids. Postmeiotic spermatids are the only cells of the seminiferous tubules that express HIP1. These findings indicate that HIP1 is required for differentiation, proliferation, and/or survival of spermatogenic progenitors. The association of HIP1 with clathrin coats and the requirement of HIP1 for progenitor survival suggest a role for HIP1 in the regulation of endocytosis.

Tracheoesophageal fistula and massive pneumoperitoneum after prolonged mechanical ventilation

We describe a patient who had two unusual complications of prolonged mechanical ventilation-tracheoesophageal fistula and pneumoperitoneum-with a fatal outcome. Recurrent pulmonary aspirations and massive abdominal distention in the setting of longstanding artificial ventilation should alert the physician to these possibilities.

Cholesterol embolism causing delayed healing of a foot ulcer

A cholesterol embolism presents with various systemic and local manifestations giving rise to a diagnostic dilemma. We report a case of cholesterol embolism of the leg that delayed the healing of a foot ulcer, necessitating a toe amputation. This report points to the potential of cholesterol emboli to cause a significant compromise in the vascular supply.

Disseminated Pseudomonas aeruginosa and necrotizing pneumonia with complete recovery

Pseudomonas aeruginosa pneumonia and recovery with treatment are rare in healthy individuals. We report the case of a 59-year-old man with P aeruginosa skin infection and sepsis, later giving rise to necrotizing pneumonia by hematogenous spread. He responded to prolonged intensive care and 3 weeks of piperacillin-tazobactam and tobramycin therapy. There was no evidence of immunosuppression other than that caused by alcoholism in this unusual case. The resulting cavity healed completely by fibrosis in 1 year.

Unilateral internuclear ophthalmoplegia and recovery with thiamine in Wernicke syndrome

Internuclear ophthalmoplegia is usually caused by multiple sclerosis, tumors, or vascular lesions of the brain stem. We report a patient with Wernicke syndrome who presented with a right-sided internuclear ophthalmoplegia. He recovered completely with intravenous thiamine (vitamin B1). There were no lesions in the magnetic resonance image (MRI) of the brain, suggesting a derangement at the cellular level as the cause.

Supernumerary nipple as a cutaneous marker of mitral valve prolapse in Asian Indians

We studied 68 Asian Indians from South India with supernumerary nipple (SN) and 49 age- and sex- matched controls without SN for evidence of mitral valve prolapse (MVP) and associated features. We found that MVP and its forme fruste were more common in the SN group (odds ratio 6.0, 95% confidence intervals 2.16 to 16.63), indicating an association of SN with MVP.

Focal bacterial nephritis (lobar nephronia) presenting as renal mass

A focal infection of the kidney can cause a diagnostic dilemma by mimicking a neoplasm. We describe a case of focal bacterial nephritis (acute lobar nephronia) caused by Escherichia coli in which the diagnosis was confirmed only after surgical exploration. Although the patient had fever on admission, urine and blood cultures were negative and fine needle aspiration of the kidney could not rule out a well-differentiated carcinoma.

Is mitral valve prolapse a manifestation of adolescent growth spurt?

The exact aetiology of mitral valve prolapse (MVP) is unknown, although this is the most common cardiac valvular abnormality currently detected. MVP has high incidence in young individuals, particularly during the second and third decades. These individuals are usually of a slender body habitus indicating higher rates of linear growth, reflective of the adolescent growth spurt. MVP might represent the imbalance in the growth dynamics of the mitral valve apparatus especially between the leaflets, chordae tendineae and the rest of the heart. Several reports suggest the transient nature of MVP and even complete disappearance. MVP with systolic click, but without a systolic murmur signifying regurgitation may be considered as a manifestation of adolescent growth spurt and a normal variant transiently occurring during particular periods of lives of otherwise normal individuals. Strategies of identification of subsets of individuals likely to harbor the more sinister and progressive form of MVP are important and need to be developed.

How do peer reviewers of journal articles perform? Evaluating the reviewers with a sham paper

Peer review process is widely used to assess the quality of scientific research and select papers for publication in biomedical journals. The method lacks standardization and objectivity. To standardize the peer review process, evaluation and rating of the performance of individual peer reviewers using a sham paper is suggested. The present study of 7 reviewers revealed ratings ranging from 0.34 (SD 0.33) to 0.45 (SD 0.5), widely differing from the set standard (ideal 0). This indicates less than optimal performance by the peer reviewers. Feedback to the peer reviewers might help in improving the standards.

The role of coconut and coconut oil in coronary heart disease in Kerala, south India

Coronary heart disease (CHD) is common in India and, recently, an increase in the incidence of CHD was reported from the South Indian state of Kerala. The traditional Indian diet is low in fat content. The high incidence of CHD in Indians is, therefore, in contrast to western studies that have correlated high fat, saturated fat and cholesterol intake to CHD. Consumption of coconut and coconut oil that contain high amounts of saturated fat and are thought to be strongly atherogenic, are believed to be one of the main reasons for the high incidence of CHD in Kerala. To explore this presumed link, we studied 32 CHD patients and 16 age and sex matched healthy controls. Consumption of coconut and coconut oil was found to be similar in both groups. The groups did not differ in the fat, saturated fat and cholesterol consumption. The results imply no specific role for coconut or coconut oil in the causation of CHD in the present set of Indian patients from Kerala. The exact reason for the high and increasing incidence of CHD among Indians is still unknown.