The Crystal Structure of Calmodulin Bound to the Cardiac Ryanodine Receptor (RyR2) at Residues Phe4246-Val4271 Reveals a Fifth Calcium Binding Site.

Calmodulin (CaM) regulates the activity of a Ca2+ channel known as the cardiac ryanodine receptor (RyR2), which facilitates the release of Ca2+ from the sarcoplasmic reticulum during excitation-contraction coupling in cardiomyocytes. Mutations that disrupt this CaM-dependent channel inactivation result in cardiac arrhythmias. RyR2 contains three different CaM binding sites: CaMBD1 (residues 1940-1965), CaMBD2 (residues 3580-3611), and CaMBD3 (residues 4246-4275). Here, we report a crystal structure of Ca2+-bound CaM bound to RyR2 CaMBD3. The structure reveals Ca2+ bound to the four EF-hands of CaM as well as a fifth Ca2+ bound to CaM in the interdomain linker region involving Asp81 and Glu85. The CaM mutant E85A abolishes the binding of the fifth Ca2+ and weakens the binding of CaMBD3 to Ca2+-bound CaM. Thus, the binding of the fifth Ca2+ is important for stabilizing the complex in solution and is not a crystalline artifact. The CaMBD3 peptide in the complex adopts an α-helix (between Phe4246 and Val4271) that interacts with both lobes of CaM. Hydrophobic residues in the CaMBD3 helix (Leu4255 and Leu4259) form intermolecular contacts with the CaM N-lobe, and the CaMBD3 mutations (L4255A and L4259A) each weaken the binding of CaM to RyR2. Aromatic residues on the opposite side of the CaMBD3 helix (Phe4246 and Tyr4250) interact with the CaM C-lobe, but the mutants (F4246A and Y4250A) have no detectable effect on CaM binding in solution. We suggest that the binding of CaM to CaMBD3 and the binding of a fifth Ca2+ to CaM may contribute to the regulation of RyR2 channel function.

Membrane-acting bacteriocin purified from a soil isolate Pediococcus pentosaceus LB44 shows broad host-range.

Bacteriocin LB44 was purified from cell-free supernatant (CFS) of Pediococcus pentosaceus LB44 using activity-guided chromatography techniques. It was stable up to 121 °C, pH 2.0-6.0, sensitive to proteinase K, papain and trypsin, and retained complete activity in the presence of organic solvents tested. The molecular weight of bacteriocin was ∼6 kDa and initial ten amino acid residues (GECGMCXECG) suggested a new compound. The loss in viable cell count and K+ ion efflux of target cells of Micrococcus luteus suggested bactericidal activity. The cell membrane of bacteriocin-treated cells was found to be ruptured which was further confirmed by Fourier Transform Infrared (FTIR) analysis suggesting interaction of bacteriocin with phospholipids in cell membrane. It showed broad host-range and inhibited the growth of Lactobacillus delbrueckii NRRL B-4525, L. plantarum NRRL B-4496, L. acidophilus NRRL B-4495, Enterococcus hirae LD3, Weissella confusa LM85, Staphylococcus aureus, Salmonella typhi ATCC 13311, Serratia marcescens ATCC 27137, Pseudomonas aeruginosa ATCC 27853, Proteus vulgaris ATCC 29905, Haloferax larsenii HA1, HA3, HA8, HA9 and HA10. These properties suggested a new bacteriocin from soil isolate P. pentosaceus LB44 which may offers possible applications in food-safety and therapeutics.

Augmenting nursing care quality and implementing change management in India: an amalgamated approach.

BACKGROUND AND AIM: High dependency on nursing care in healthcare delivery systems in recent times has made the quality appraisal of nursing care even more imperative for nursing administrators. This study demonstrates the utility of a two-phase technique to identify the most significant shortcomings pertaining to nursing care delivery in general wards of a tertiary care hospital. The same could be used to set priorities. METHODS: The first phase involved the use of the Delphi technique facilitating the experts to identify the major problems. The mean rank score was used for grading the problems. The second phase of the study involved getting direct feedback from the ward nurses. The sample size was 147 at a level of significance of 5%. RESULTS: Consensus was reached among experts on four problems that should galvanize nursing administration vis-à-vis quality improvement. The responses of ward nurses in the second phase gave a better insight into these problems. CONCLUSION AND IMPLICATIONS FOR NURSING MANAGEMENT: Identifying the existing problems and fostering a team spirit among all stakeholders hold the key in strategizing quality improvement in nursing care. Nursing administrators worldwide, after making suitable situation-specific customizations, may use this approach to realize both these objectives.

COVID-19 Vaccine Acceptance During Pregnancy, Women's Views, and Influencing Factors.

BACKGROUND: COVID-19 vaccination is advised for pregnant women all over the world; however, vaccine acceptance is variable across the globe. METHODS: This study was conducted by enrolling 292 antenatal women attending the outpatient department (OPD) in a tertiary care hospital in Delhi, India, between August 1, 2022 and October 31, 2022, with the aim to determine the acceptability of vaccination against COVID-19 disease in pregnancy, women's views regarding the vaccine and to ascertain reasons for acceptance or denial during pregnancy. RESULT: Of the 292 pregnant women who completed the questionnaire, 39.73% had received both doses of vaccination against COVID-19 disease before pregnancy, and 39.04% had received a single dose. Twenty-one percent of women did not receive any vaccine. Eighty-four percent of the unvaccinated and 35% of the women with a single dose of the vaccine refused further doses during pregnancy. The most common concern was the fear that the vaccine might cause harm to the fetus (35.3%), followed by the fear of vaccine-related reactions (25.4%). Also, 14.6% of women feared that the vaccine might cause them to abort the ongoing pregnancy. Thirteen percent of women stated their intent to receive the vaccine after they were informed regarding its safety and requirement. No difference was found in the acceptability of the vaccine based on the educational status of women or on the monthly income of the families. CONCLUSION: Adequate communication regarding safety information on COVID-19 vaccines is a must for pregnant women and their families to provide reassurance about the need and safety of the vaccines. It would facilitate making informed decisions and is likely to be helpful in increasing vaccine acceptance.

LC-MS/MS identification and structural characterization of isolated cyclotides from precursor sequences of Viola odorata L. petiole tissue using computational approach.

Viola odorata L., known for its pharmacological properties, produces a plethora of structurally stable peptides called cyclotides. Cyclotides are macrocyclic peptides with a unique topology containing a cyclic cystine knot motif. The objective of the present study was to identify the precursor sequences and respective cyclotide domains from the petiole tissue of V. odorata. The study is based on the isolation, identification, and characterization of the cyclic peptides using LC-MS/MS followed by database searching and processing. Our study detected 47 precursor sequences encoded for 15 reported cyclotides, 4 putative novel cyclotides, and 3 acyclotides from the petiole tissue. The novel sequences identified were based on the hydrophobic nature, disulfide bonds, conserved cysteine residues, and presence of cyclic peptide backbone. Four putative novel and three acyclotides were also characterized for their sequence and subfamilies. A protein diversity wheel was used to reveal the variation in the amino acid sequence and cysteine residue conservation in the isolated cyclotides. The results provide information about the number of cyclotides and acyclotides from the petiole tissue and their sequence diversity, which may constitute novel tools for future research on this plant species.

Effect of amino acid on the surface adsorption and micellar properties of surface active ILs varying in cationic head groups.

The interfacial along with bulk characteristics of the aqueous solutions of ILs with dissimilar cationic head group viz. 1-dodecyl-3-methylimidazolium bromide ([C12mim][Br]), and N-dodecyl-N-methylmorpholinium bromide ([Mor1,12][Br]) in the absence and the presence of an amino acid L-Methionine as an external additive have been examined by electrical conductivity, UV-Visible, surface tension, and DLS measurements. The CMC values, and the lowest maximum surface excess concentration (Гmax) achieved from all three techniques, and surface tension measurements respectively displayed more surface activity of the [C12mim][Br] than the [Mor1,12][Br]. Also, the morpholinium head group is less hazardous than imidazolium, it can be utilised to design ILs that are greener, mainly in combination with polar, small, and non-toxic side chains and anions.

Genotyping-by-Sequencing Based Investigation of Population Structure and Genome Wide Association Studies for Seven Agronomically Important Traits in a Set of 346 Oryza rufipogon Accessions.

Being one of the most important staple dietary constituents globally, genetic enhancement of cultivated rice for yield, agronomically important traits is of substantial importance. Even though the climatic factors and crop management practices impact complex traits like yield immensely, the contribution of variation by underlying genetic factors surpasses them all. Previous studies have highlighted the importance of utilizing exotic germplasm, landraces in enhancing the diversity of gene pool, leading to better selections and thus superior cultivars. Thus, to fully exploit the potential of progenitor of Asian cultivated rice for productivity related traits, genome wide association study (GWAS) for seven agronomically important traits was conducted on a panel of 346 O. rufipogon accessions using a set of 15,083 high-quality single nucleotide polymorphic markers. The phenotypic data analysis indicated large continuous variation for all the traits under study, with a significant negative correlation observed between grain parameters and agronomic parameters like plant height, culm thickness. The presence of 74.28% admixtures in the panel as revealed by investigating population structure indicated the panel to be very poorly genetically differentiated, with rapid LD decay. The genome-wide association analyses revealed a total of 47 strong MTAs with 19 SNPs located in/close to previously reported QTL/genic regions providing a positive analytic proof for our studies. The allelic differences of significant MTAs were found to be statistically significant at 34 genomic regions. A total of 51 O. rufipogon accessions harboured combination of superior alleles and thus serve as potential candidates for accelerating rice breeding programs. The present study identified 27 novel SNPs to be significantly associated with different traits. Allelic differences between cultivated and wild rice at significant MTAs determined superior alleles to be absent at 12 positions implying substantial scope of improvement by their targeted introgression into cultivars. Introgression of novel significant genomic regions into breeder's pool would broaden the genetic base of cultivated rice, thus making the crop more resilient.

Purification and Characterization of a New Halocin HA4 from Haloferax larsenii HA4 Isolated from a Salt Lake.

Halocins are antimicrobial peptides secreted by different members of haloarchaea. Halocin HA4 was purified from Haloferax larsenii HA4 using combination of ultrafiltration and chromatographic techniques. It was found to be ~ 14 kDa with unique N-terminal sequence, H2N-AEEEIFXPDX, which did not show homology with the known sequence suggesting a new/novel compound. It was found to be heat resistant up to 100 °C, stable at pH 2.0-10.0, and retained complete activity in the presence of different organic compounds such as methanol, ethanol, acetone, isopropanol, ethyl acetate, Tween 80, acetonitrile, SDS, Triton X-100, and urea. However, complete activity was reduced after the treatment with trypsin, papain, and proteinase K suggesting proteinaceous nature of the compound. The cytocidal nature of halocin HA4 was evidenced with complete loss of viable count of indicator strain, H. larsenii HA10. The change in FTIR spectrum of halocin-treated cells suggested halocin HA4 interacts with cell membrane and nucleic acids of the target cells. Thus, we report a new halocin inhibitory to related strains and may be applied in the preservation of salted foods and leather hides in the respective industries.

Regulation of secondary antioxidants and carbohydrates by gamma-aminobutyric acid under salinity-alkalinity stress in rice (Oryza sativa L.).

Gamma-aminobutyric acid (GABA) is known to improve tolerance against abiotic stresses but less studied for salinity-alkalinity stress (SAS). In the present study, GABA regulation of secondary antioxidants and carbohydrates was studied in rice in the presence and absence of SAS. About 1.5 mM GABA, 200 mM SAS, GABA + SAS were applied to 5-day old seedlings, and thereafter measurements were done in shoots and roots at 24, 48, 72 h in rice cultivars CSR 43 (tolerant) and Pusa 44 (susceptible). SAS was applied in molar ratio of 1:9:9:1 of NaCl:Na2SO4:NaHCO3:Na2CO3. Peroxidases (POX), polyphenol oxidases (PPO), lignin, flavonoids and phenolics from secondary metabolism and invertases, hexoses, sucrose and starch from carbohydrate metabolism were studied. Pusa 44 increased soluble POX, lignin, flavonoids in shoots but deficient in roots during stress period but improved under GABA + SAS. CSR 43 increased soluble POX, lignin, flavonoids in roots consistently throughout the stress period and also improved under GABA + SAS. Early increase in cell wall POX/PPO under SAS was seen in CSR 43 only, while Pusa 44 improved this under GABA + SAS. During stress period, CSR 43 showed an increasing trend of cell wall invertase activity, sucrose, sucrose-to-hexose ratio and starch in roots but Pusa 44 showed poor such response but Pusa 44 improved starch, sucrose, sucrose-to-hexose ratio by significant amount in both shoots and roots under GABA + SAS. The overall study indicated GABA as an important regulator of secondary and carbohydrate metabolisms. Besides improving secondary antioxidants, GABA under stress may improve cellular reserves like starch and protective sugars like sucrose.

Isolation and characterization of cyclotides from the leaves of Viola odorata L. using peptidomic and bioinformatic approach.

Cyclotides are true gene products characterized by the presence of six conserved cysteine residues and knotted arrangement of three disulfide bonds. These macrocyclic peptides show exceptional resistance to thermal, chemical and enzymatic degradation which is defined due to their three-dimensional folding. The current study describes an efficient strategy involving reduction, enzymatic digestion and mass spectroscopy sequencing for the identification of the precursor sequences and the cyclotide domains present in the leaf tissue of Viola odorata. We observed 122 partial peptide sequences containing 31 cyclotide domains along with 19 unique sequences consisting of putative novel cyclotides and acyclotides. Four precursor sequences consisting of putative new and already reported domains were further characterized for cyclotide domains, their structure and subfamilies. The sequences revealed the presence of classic knotted cyclotide folds with similar six characteristic loops but different amino acid residues. Molecular modeling indicated that the secondary structures present in the cyclotides are mainly α-helix and random coils. Variation in the sequences and conservation in cysteine residues in the cyclotides was revealed by protein diversity wheel. The significant information observed in the current study expands our knowledge about the structure and type of cyclic peptides in V. odorata leaves. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02763-2.

Molecular characterization of PgUFGT gene and R2R3-PgMYB transcription factor involved in flavonoid biosynthesis in four tissues of wild pomegranate (Punica granatum L.).

The diversity on fruit colouration in plants directly depends on the flavonoids that explain the development of different pigmentation patterns. Anthocyanins are the major class of flavonoid pigments that are synthesized through flavonoid biosynthetic pathway. In the present study, two genes: PgUFGT gene and R2R3-PgMYB gene, involved in anthocyanin biosynthesis were analysed in four tissues of wild pomegranate. The structural genes, UDP-glucose: flavonoid-3-O-glucosyl transferase (PgUFGT; GenBank accession number: MK058491) and its myeloblastosis transcription factor (R2R3-PgMYB; GenBank accession number: MK092063) were isolated and their expression pattern were studied. Molecular modelling indicated that the main secondary structures of PgUFGT and R2R3-PgMYB genes are α-helix and random coil. In addition, expression profiling of PgUFGT and R2R3-PgMYB by quantitative-real time PCR indicated a positive correlation between anthocyanin content and their expression in leaves, flowers, green and red fruits of wild pomegranate. Among all the tissues, the red fruit exhibited high transcripts levels of PgUFGT as well as R2R3-PgMYB transcription factor. An extensive homology with UFGTs from other plants was revealed on comparative and bioinformatic analyses. Present study reveals that PgUFGT plays a predominant role in anthocyanin content in wild pomegranate fruits. Further, it is strongly suggested that R2R3-PgMYB transcription factor regulates the anthocyanin biosynthesis in wild pomegranate via expression of PgUFGT gene. This is the first study which provides an insight on expression profile of PgUFGT and R2R3-PgMYB that are involved in colour development and fruit ripening in wild pomegranate.

A Preliminary Attempt to Profile Tympanometric Measures in Infants Using High Frequency Probe Tones.

There is dearth of published data on high frequency tympanometric measures for infants in Indian context. Aim of present study was to profile Peak compensated static acoustic admittance (Ytm), Tympanometric peak pressure (TPP), Tympanometric width (TW) and Equivalent ear canal volume (Vea) in infants. Cross-sectional study on 50 infants with present TEOAEs and with risk indicators for hearing loss. Tympanometry was performed using GSI-Tympstar for 678 and 1000 Hz probe tones. Descriptive statistics were used to determine mean, SD and minimum and maximum for both genders. Using 678 Hz, Ytm ranged from 0.09 to 1. 48 mmho (males) and 0.11 to 1.14 mmho (females), while with 1000 Hz ranged from 0.15 to 1.49 (males) and 0.13-1.61 mmho (females). Using 678 Hz, TPP ranged from -95 to 70 daPa (males) and -155 to 80 daPa (females), while with 1000 Hz ranged from -75 to 95 daPa (males) and -145 to 50 daPa (females). Using 678 Hz, TW ranged from 30 to 190 daPa (males) and 40-23 daPa (females), while with 1000 Hz ranged from 60 to 210 daPa (males) and 40-183 daPa (females). Using 678 Hz, Vea ranged from 0.11 to 1.7 mmho (males) and 0.14-2.5 mmho (females), while with 1000 Hz ranged from 0.14 to 2.0 mmho (males) and 0.14-3.6 mmho (males). This study was a preliminary attempt to profile the tympanic measures. Ytm values were lesser or similar to other studies, TPP and Vea values had lower and narrow range, while TW were more than previous studies.

Epidemiological profile of snake-bite cases from Haryana: A five year (2011-2015) retrospective study.

Varieties of venomous snakes inhabit in the world which accidentally take thousands of human lives every year. This severe medical emergency constantly persuades national and international health agencies to look at efficient epidemiological profiling of snake-bite cases for the proper management of this sympathetic problem. Establishing the accurate database of snake-bite in humans from different localities of India may perhaps lack certainty due to few inevitable reasons such as consideration of this problem as less emergent problem in disparity to pesticide poisoning, difficulty in the accessibility to rural and tribal areas where chances of snake-bite remain ceiling, lack of inspiring models of snake-bite management training, reduced reporting system, and pitiable maintenance of hospital data in India. Therefore, the present modest study was carried out to explore valuable information regarding snake-bite problem in Haryana. Factual data on snake-bite incidences happened from 2011 to 2015 were collected from government hospitals and medical institutes of Haryana. This retrospective study disclosed a few characteristic points related to the frequency of snake-bite cases, gender involved, anti-snake venom (ASV) treatment, and numbers of deaths with snake-bite. Records revealed a total of 6555 cases of snake-bite including 130 deaths reported in Haryana during the study period. A significant variation in the occurrence of snake-bite cases was also recorded in different areas of Haryana. There was a huge database of recorded snake-bite cases from government medical institute but district wise survey disclosed the maximum number of snake-bite incidences, especially amongst males from Panchkula. The present study has provided a more updated and comprehensive record of snake-bite from Haryana during 2011-2015. A huge burden of snake-bite amongst human was found in Haryana; hence, the findings of this study purposely enlighten people about the size of this problem in the selected region. However, this study also remained limited due to lack of information on a few important parameters and availability of homogeneous data.

Sequential MR imaging (with diffusion-weighted imaging) changes in metronidazole-induced encephalopathy.

Metronidazole-induced neuro-toxicity, though rare, is known. A characteristic spatial distribution of lesions in cerebellar dentate nuclei and dorsal pons is known. However, temporal progression of lesions on magnetic resonance imaging (MRI) has not been described previously. We describe two such cases which presented initially with splenial hyperintesity and showed progression to characterstic lesions. Both cases improved with stoppage of metronidazole.

Uterine Rupture: A Seven Year Review at a Tertiary Care Hospital in New Delhi, India.

OBJECTIVE: To identify the obstetric risk factors, incidence, and causes of uterine rupture, management modalities, and the associated maternal and perinatal morbidity and mortality in one of the largest tertiary level women care hospital in Delhi. MATERIALS AND METHODS: A 7-year retrospective analysis of 47 cases of uterine rupture was done. The charts of these patients were analyzed and the data regarding demographic characteristics, clinical presentation, risk factors, management, operative findings, maternal and fetal outcomes, and postoperative complications was studied. RESULTS: The incidence of rupture was one in 1,633 deliveries (0.061%). The vast majority of patients had prior low transverse cesarean section (84.8%). The clinical presentation of the patients with rupture of the unscarred uterus was more dramatic with extensive tears compared to rupture with scarred uterus. The estimated blood loss ranged from 1,200 to 1,500 cc. Hemoperitoneum was identified in 95.7% of the patient and 83% of the patient underwent repair of rent with or without simultaneous tubal ligation. Subtotal hysterectomy was performed in five cases. There were no maternal deaths in our series. However, there were 32 cases of intrauterine fetal demise and five cases of stillbirths. CONCLUSIONS: Uterine rupture is a major contributor to maternal morbidity and neonatal mortality. Four major easily identifiable risk factors including history of prior cesarean section, grand multiparity, obstructed labor, and fetal malpresentations constitute 90% of cases of uterine rupture. Identification of these high risk women, prompt diagnosis, immediate transfer, and optimal management needs to be overemphasized to avoid adverse fetomaternal complications.

Contribution of exotoxin A of Pseudomonas aeruginosa in acute and chronic experimental renal infection.

The role of Pseudomonas aeruginosa exotoxin A was studied in acute and chronic pyelonephritis models employing an exotoxin A-producing strain PAO, and its toxin deficient mutant PAOT1. Interestingly, the mutant strain was found to be at an advantage in its ability to induce acute pyelonephritis and it induced severer renal pathology. No significant differences were observed in the ability of the parent strain and its mutant to induce chronic renal inflammation.

Diatomological mapping of water bodies--a future perspective.

Corpse floating in running or stagnant water may not keep a tail of its exact place of drowning. Disagreement between diatoms recovered from the body and those in the presumed drowning medium may possibly advocate that body has been moved from its exact site of drowning. It emphasizes on the importance of water sampling from where the body is found. Diatomological Mapping (D-Mapping) of water bodies assumes to be an important means to solve this problem even when reference water sample is not available. Information of the present attempt has been exercised to scratch the authenticity of D-maps of these four water bodies after a gap of four years (2007-2011). Current records have been found interesting and significant for the authenticity of D-maps for a prolong characterization of water bodies.