Mechanistic studies on bioremediation of dye using Aeromonas veronii immobilized peanut shell biochar.

Recalcitrant chemicals in the environment not only present obstacles to living organisms but also contribute to the degradation of natural resources. One contribution to environmental pollution is the discharge of synthetic dyes from the textile sector. This study investigates the combined effect of microbial cells and biochar on eliminating methyl orange (MO) dye. The immobilization of Aeromonas veronii on peanut shell biochar (APSB) was conducted to investigate its efficacy in removing MO dye from water. PSB synthesized by pyrolysis at 300 °C for 120 min showed maximum bacterial immobilization potential. The highest degradation rate of 96.19 % was achieved in APSB within 96 h using MO dye concentration of 100 mg L-1, incubation temperature of 37 °C, pH 7, and biocatalyst dosage of 1g L-1. In comparison, free cells achieved degradation rates of 72.53 % and 61.56 % for PSB. Moreover, the adsorption process was primarily controlled by PSB, with subsequent dye mineralization by A. veronii, as supported by FTIR and LC-MS studies. Moreover, this innovative approach exhibited the reusability of the biocatalyst, giving 76.23 % removal after fifth cycle, suggesting sustainable alternative in dye remediation and potential option for real-time applications.

Imaging Features Differentiating Between Cardiac Sarcomas and Hematologic Neoplasms.

PURPOSE: The aim of the study is to assess the efficacy of computed tomography (CT) and positron emission tomography (PET)/CT findings in differentiating between cardiac sarcoma and cardiac hematologic neoplasms, which are rare but potentially lethal primary cardiac malignancies. MATERIALS AND METHODS: We searched the electronic medical record for pathology-proven cases from 2012 to 2023, finding 69 patients (46 sarcomas, 23 cardiac hematologic neoplasms). Imaging features including tumor size, atrioventricular (AV) groove involvement, right coronary artery (RCA) encasement by 180°, pericardial effusion, lymphadenopathy, and metabolic activity on fluorodeoxyglucose PET were reviewed by a radiology fellow. Statistical analysis was performed using Fisher exact test and Wilcoxon test. RESULTS: Cardiac sarcoma patients were younger (median age 49 years) compared to patients with cardiac hematologic malignancies (66 years, P = 0.006). While tumor size and chamber involvement were similar between the 2 categories, hematologic malignancies exhibited a notable predilection for AV groove involvement (70% vs 43%, P = 0.04) and RCA encasement (52% vs 26%, P = 0.02). Pulmonary metastases were more frequent in sarcoma cases (33% vs 4%, P = 0.006). There was no significant difference in fluorodeoxyglucose uptake. Lymphadenopathy was similar between the 2 disease groups. A decision tree constructed using AV groove involvement and patient age achieved 75% accuracy in predicting the diagnosis of the mass. CONCLUSIONS: Overall, there is a substantial overlap in imaging features of cardiac sarcomas and hematologic malignancies involving the heart. Involvement of the AV groove and RCA encasement can allow a radiologist to favor hematologic malignancy. Ultimately, biopsy is required to establish a diagnosis.

Bounding box-based 3D AI model for user-guided volumetric segmentation of pancreatic ductal adenocarcinoma on standard-of-care CTs.

OBJECTIVES: To develop a bounding-box-based 3D convolutional neural network (CNN) for user-guided volumetric pancreas ductal adenocarcinoma (PDA) segmentation. METHODS: Reference segmentations were obtained on CTs (2006-2020) of treatment-naïve PDA. Images were algorithmically cropped using a tumor-centered bounding box for training a 3D nnUNet-based-CNN. Three radiologists independently segmented tumors on test subset, which were combined with reference segmentations using STAPLE to derive composite segmentations. Generalizability was evaluated on Cancer Imaging Archive (TCIA) (n = 41) and Medical Segmentation Decathlon (MSD) (n = 152) datasets. RESULTS: Total 1151 patients [667 males; age:65.3 ± 10.2 years; T1:34, T2:477, T3:237, T4:403; mean (range) tumor diameter:4.34 (1.1-12.6)-cm] were randomly divided between training/validation (n = 921) and test subsets (n = 230; 75% from other institutions). Model had a high DSC (mean ± SD) against reference segmentations (0.84 ± 0.06), which was comparable to its DSC against composite segmentations (0.84 ± 0.11, p = 0.52). Model-predicted versus reference tumor volumes were comparable (mean ± SD) (29.1 ± 42.2-cc versus 27.1 ± 32.9-cc, p = 0.69, CCC = 0.93). Inter-reader variability was high (mean DSC 0.69 ± 0.16), especially for smaller and isodense tumors. Conversely, model's high performance was comparable between tumor stages, volumes and densities (p > 0.05). Model was resilient to different tumor locations, status of pancreatic/biliary ducts, pancreatic atrophy, CT vendors and slice thicknesses, as well as to the epicenter and dimensions of the bounding-box (p > 0.05). Performance was generalizable on MSD (DSC:0.82 ± 0.06) and TCIA datasets (DSC:0.84 ± 0.08). CONCLUSION: A computationally efficient bounding box-based AI model developed on a large and diverse dataset shows high accuracy, generalizability, and robustness to clinically encountered variations for user-guided volumetric PDA segmentation including for small and isodense tumors. CLINICAL RELEVANCE: AI-driven bounding box-based user-guided PDA segmentation offers a discovery tool for image-based multi-omics models for applications such as risk-stratification, treatment response assessment, and prognostication, which are urgently needed to customize treatment strategies to the unique biological profile of each patient's tumor.

Clinical and Radiographic Evaluation of Various Herbal Products Used with Zinc Oxide as an Obturating Material in Primary Teeth: An In Vivo Study.

AIM: To compare the clinical and radiographically mixture of zinc oxide with Aloe vera, Curcumin and neem as an obturating material for pulpectomy. MATERIALS AND METHODS: The study comprised of age group 4-8 years children requiring endodontic treatment for at least a single primary molar tooth. Sixty primary molar teeth from 43 children were divided equally and randomly into four study groups. The materials used for obturation were zinc oxide powder (ZnO) and Eugenol (ZOE) (group I), ZnO and Aloe vera Gel (group II), ZnO and Curcumin Powder (group III), ZnO and neem extract (group IV). They were evaluated clinically and radiographically at immediate postoperative and then at 1-, 3-, 6-, and 9-month intervals. RESULTS: At the end of 9 months, the Chi-square test revealed 100% success rate for recovery of pain in group I and III, 66.66% in group II and 93.3% in group IV. The success rates for absence of abscess and for periradicular radiolucency in group I, III, and group IV were 100% and 66.6% for group II. The success rate for periapical radiolucency in group I and group III was 100%, in group II 66.6% and in group IV 93.35%. The success rate for all the groups shows 100% success in terms of pathological root resorption. CONCLUSION: Zinc oxide eugenol has proven to be the best obturating material. ZnO with Aloe vera showed a success rate which is significantly lower than the other medicaments. ZnO with Curcumin and ZnO with neem had shown promising clinical and radiographical results. CLINICAL SIGNIFICANCE: ZnO with Curcumin and ZnO with neem can be used as a root canal filling material in primary teeth with further follow-up studies.

Overlooked contributions of Ayurveda literature to the history of physiology of digestion and metabolism.

Ayurveda is a traditional system of healthcare that is native to India and has a rich documented literature of its own. Most of the historians agree that the documentation of core Ayurveda literature took place approximately in between 400 BCE and 200 CE, while acknowledging that the roots of its theoretical framework can be traced back to a much earlier period. For multiple reasons many significant contributions of Ayurveda literature to various streams of biological and medical sciences have remained under-recognized while recounting the historical milestones of development. This is true in the context of the physiology of digestion and metabolism too. In this communication we try to reconstruct a picture of the processes of digestion and metabolism as had been understood by ancient Ayurveda scholars. Though this understanding was primitive and insufficient in many ways, we argue that this deserves to be documented and acknowledged. To help with grasping the importance of these contributions, we juxtapose them with the corresponding insights pertaining to this subject reported by prominent western scientists. The major contributions of Ayurveda that have been recounted in this paper are those related to the description of three distinct phases of digestion (Avasthapaka), multiple sets of transformative entities acting at different levels of metabolism (Agni), and the roles ascribed to various internal and external factors in executing these physiological functions.

Transcriptome analysis of Leucojum aestivum and identification of genes involved in norbelladine biosynthesis.

MAIN CONCLUSION: Transcriptome analysis of Leucojum aestivum led to the identification of 50 key genes associated with Amaryllidaceae alkaloid biosynthesis including norbelladine synthase which localized in the cytosol and catalyzed norbelladine formation. The Amaryllidaceae alkaloids (AAs) are a large group of plant specialized metabolites, which are known for their biological activities. Although the general chemical reactions in the AA biosynthetic pathway have been proposed, the genes and enzymes of the pathway remain largely unstudied. All AAs are synthesized from a common precursor, norbelladine, by the condensation of tyramine and 3,4-dihydroxybenzaldehyde. The enzyme norbelladine synthase (NBS) which catalyzes the condensation reaction has only been characterized at a molecular level from one species, and the subcellular localizations have not been explored. Hence, the intracellular compartments wherein the AAs are biosynthesized remain unknown. In this study, a first comprehensive transcriptomic analysis of summer snowflake (Leucojum aestivum) was done to identify key genes associated with AA biosynthesis. Fifty orthologous genes were identified and deposited into GenBank. In addition, we identified and further characterized NBS from the transcriptome of L. aestivum and previously reported Narcissus papyraceus. Phylogenetic analysis showed that LaNBS, NpNBS1 and NpNBS2 shared high amino acid identity. The heterologous expression of LaNBS produced a recombinant protein with NBS activity. Bioinformatic prediction and C-terminal GFP tagging in transiently transformed Nicotiana benthamiana showed that LaNBS, NpNBS1 and NpNBS2 were likely localized to the cytosol which suggests that the AA biosynthesis starts in the cytosol. This study provides an Amaryllidaceae transcriptome that will be very helpful to identify genes for characterization studies in AA metabolism in planta or using heterologous systems. In addition, our study will facilitate the bioengineering of AA biosynthetic pathway in plants or in microorganisms.

A Comparative Analysis of Voids and Sealing Ability of Different Obturating Techniques Using CBCT.

AIM: To evaluate voids and sealing ability using a disposable syringe, endodontic pressure syringe, and Skinni syringe with NaviTip in primary molars with cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The 15 extracted primary mandibular molars with at least one root ≥8 mm length and an equal number of mesiobuccal canals were divided into three groups, i.e., obturation using a disposable syringe, an endodontic pressure syringe, and a Skinni syringe with NaviTip, respectively. The evaluation of the apical seal was determined as the measurement between the apical end of the filling material and the radiographic apex. The quality of the filling was determined by the size, number, type, and location of voids present. Statistical analysis was done using the Chi-square test and post-hoc test. RESULTS: The endodontic pressure syringe score was the highest and statistically significant in obtaining apical seal (p = 0.013). Disposable syringe shows highest size of voids (p = 0.01) in which type I-voids (p = 0.04) and type S-voids (p = 0.07) were statistically significant. The location of voids was maximum at the middle third of the root (p = 0.016). CONCLUSION: The endodontic pressure syringe provided the best root canal obturation of primary molars, whereas the disposable syringe was least effective with the maximum number and size of voids. CLINICAL SIGNIFICANCE: Comparing the voids and sealing abilities of different obturating techniques with CBCT would help the pediatric practitioners for better outcome of obturation in primary teeth.

The genetics of Cannabis-genomic variations of key synthases and their effect on cannabinoid content.

Despite being a controversial crop, Cannabis sativa L. has a long history of cultivation throughout the world. Following recent legalization in Canada, Cannabis is emerging as an important plant for both medicinal and recreational purposes. Recent progress in genome sequencing of both cannabis and hemp varieties allow for systematic analysis of genes coding for enzymes involved in the cannabinoid biosynthesis pathway. Single-nucleotide polymorphisms in the coding regions of cannabinoid synthases play an important role in determining plant chemotype. Deep understanding of how these variants affect enzyme activity and accumulation of cannabinoids will allow breeding of novel cultivars with desirable cannabinoid profiles. Here we present a short overview of the major cannabinoid synthases and present the data on the analysis of their genetic variants and their effect on cannabinoid content using several in-house sequenced Cannabis cultivars.

Disrupting the quorum sensing mediated virulence in soft rot causing Pectobacterium carotovorum by marine sponge associated Bacillus sp. OA10.

Strains of genus Pectobacterium are major cause of soft rot diseases in fruits and vegetables worldwide. Traditional control methods have not been very successful in combating the pathogenesis. As a result there has been an emerging need for developing an alternative ecofriendly and economical strategy. The pathogenesis of Pectobacterium sp. is mediated by quorum sensing (QS) and approaches based on inhibition of QS system to shut down the virulence genes without affecting growth of the pathogen may serve the purpose. Bacillus sp. OA10 associated with purple sponge Haliclona sp. was found to possess extracellular quorum quenching activity. The OA10 extract inhibited QS dependent virulence of Pectobacterium carotovorum subsp. carotovorum BR1 (PccBR1) at low concentrations (0.2 mg) as evident from 77.56 ± 6.17% reduction in potato maceration with complete inhibition by 0.8 mg. Inhibition of plant cell wall degrading enzymes (PCWDE) and carbapenem production by PccBR1 in presence of OA10 extract indicated disruption of the two QS pathways ExpI/ExpR and CarI/CarR in PccBR1. Bacillus sp. OA10 was not found to degrade acyl homoserine lactone (AHL), instead exhibited QSI activity by probably inhibiting AHL synthesis in PccBR1. Absence of enzymatic principle in quorum sensing inhibitor (QSI) is beneficial as enzymes may get inhibited by various factors during their application. OA10 extract did not affect growth of PccBR1, thereby reducing the chance of developing resistance against the QSI. Thus, Bacillus sp. OA10 can prove to be a good prospective candidate for QSI based novel biocontrol formulations.

A Comparative Quantitative Assessment of Salivary Iga and Alpha Amylase in Caries Free and Caries Active Children.

OBJECTIVES: The aim of the study was to assess the salivary IgA (immunoglobulin A) and alpha amylase levels in the unstimulated whole saliva samples of caries-free and caries-active children and correlate it with the caries status and age. STUDY DESIGN: The salivary IgA and amylase was investigated in 100 children in the range of 8-12 years divided in two groups, control group (DMFT and/or deft = 0) and study group (DMFT/deft score ≥5). The salivary IgA was measured using kit based on two-site sandwich enzyme immunoassay principle and amylase was estimated using the vitro amyl slides. RESULTS: The mean salivary IgA and amylase levels in the saliva of the children in the control group was found to be significantly increased (p=.001 and p=.014 respectively) whereas the relationship between salivary IgA and amylase levels in the saliva of the children was found to be insignificant with the age (p=.392 and p=.306 respectively). CONCLUSIONS: The results indicated that salivary IgA and amylase levels in saliva increased significantly in caries free children and the level of salivary IgA and alpha amylase has no significant relation with the age of the children.

Functional interrelation of MYC2 and HY5 plays an important role in Arabidopsis seedling development.

Arabidopsis MYC2 bHLH transcription factor plays a negative regulatory role in blue light (BL)-mediated seedling development. HY5 bZIP protein works as a positive regulator of multiple wavelengths of light and promotes photomorphogenesis. Both MYC2 and HY5, belonging to two different classes of transcription factors, are the integrators of multiple signaling pathways. However, the functional interrelations of these two transcription factors in seedling development remain unknown. Additionally, whereas HY5-mediated regulation of gene expression has been investigated in detail, the transcriptional regulation of HY5 itself is yet to be understood. Here, we show that HY5 and MYC2 work in an antagonistic manner in Arabidopsis seedling development. Our results reveal that HY5 expression is negatively regulated by MYC2 predominantly in BL, and at various stages of development. On the other hand, HY5 negatively regulates the expression of MYC2 at various wavelengths of light. In vitro and in vivo DNA-protein interaction studies suggest that MYC2 binds to the E-box cis-acting element of HY5 promoter. Collectively, this study demonstrates a coordinated regulation of MYC2 and HY5 in blue-light-mediated Arabidopsis seedling development.

In Vitro: Cytotoxicity, Apoptosis and Ameliorative Potential of Lawsonia inermis Extract in Human Lung, Colon and Liver Cancer Cell Line.

Cancer has emerged as a major public health issue in developed as well as in developing countries. Plant-derived molecules are widely being used in the treatment of cancer due to their minimum side effects. Lawsonia inermis (Henna) is one of the medicinal plants containing many therapeutic properties. In the present study, bioactive components of L. inermis extract were analyzed by LCMS/MS method and validated. Lawsone (3.5%) is primarily responsible for cytotoxic and anti-cancerous activities. These properties were studied on human lung carcinoma (A549), colorectal cancer (DLD1) and Hepatocellular carcinoma (HepG2) cancer cell lines. The activities were assessed by MTT assay, evaluation of apoptosis by measuring the production of Reactive Oxygen Species (ROS) and mitochondrial membrane potential of the cancer cell lines. Moreover, apoptosis in the respective cancer cell lines was also determined by chromatin condensation and DNA fragmentation using Hoechst 33528 and propidium iodide (PI) staining. The preliminary in vitro result of MTT showed that the henna extract induces cytotoxic properties against A549, DLD1, HepG2 with IC50values 490, 480 and 610 µg/ml respectively (more than 40% growth inhibition). In addition, the extract induced a concentration-dependent rise in ROS production which was 84, 102, and 110% in HepG2, DLD1 AND A549 respectively at 300 µg/ml, whereas at 400 µg/ml concentration it was 86, 102, and 106% in respective cell lines while decreasing mitochondrial membrane potential was more than 20% in the investigated cell lines. The extract also provoked changes associated with apoptosis and the data indicate that the ROS production leads to a diminution in mitochondrial membrane potential and this correlated with the extract cytotoxicity.

Bacteria associated with marine macroorganisms as potential source of quorum-sensing antagonists.

Samples were collected from different undisturbed areas along the coast of Gujarat like Okha, Diu, Veraval, and Somnath. A total of 68 marine isolates were obtained out of which 53 were associated with various marine macroorganisms like sponges, gastropods, and algae, whereas 15 were free living. Quorum-quenching ability of all the isolates was tested against Chromobacterium violaceum MK by co-culture technique as a way to simultaneously detect signal-degrading as well as nondegrading quorum-sensing inhibitors. Nineteen macroorganism-associated bacteria and eight free-living bacteria were found to possess quorum-sensing inhibitory activity against C. violaceum MK without affecting its growth. Isolate OA22 from grape alga and OA10 from purple sponge (Haliclona sp.) were found to possess the highest C6-HSL degradation activity and extracellular non-N-acyl-homoserine lactone degrading QSI activity, respectively. OA22 was also found to degrade 3-oxo-C12 homoserine lactone. Acid recovery of both the C6- and C12-HSL after degradation by OA22 indicated the presence of lactonase enzyme in the isolate. Cell-free supernatant of OA10 was extracted with ethyl acetate to obtain the quorum-quenching compound. Pigment inhibition in C. violaceum MK treated with OA10 extract was demonstrated in various ways and was indicative of QSI activity of the extract without degradation of the quorum-sensing signaling molecule. The isolates OA22 and OA10 were identified as Desemzia incerta and Bacillus sp., respectively, by 16S ribosomal DNA sequence analysis.

Clinico-Radiological Evaluation and Correlation of CT Chest Images with Progress of Disease in COVID-19 Patients.

PURPOSE: The present study was undertaken to investigate and quantify the severity of COVID-19 infection on high-resolution chest computed tomography (CT) and to determine its relationship with clinical parameters. This study also aimed to see CT changes with clinical recovery or progression of disease. MATERIALS AND METHODS: In an attempt to provide extensive information pertaining to clinical and radiological characteristics of COVID-19, the present study was undertaken in 80 hospitalized patients. The patients were COVID-19 confirmed positive by genomic analysis through RT-PCR at tertiary care center in Jaipur. Initially all patients were evaluated for their clinical parameters and then correlated with HRCT chest after hospitalization. CT findings correlated with duration of disease to assess progress or recovery. RESULTS: A total of 80 patients of laboratory confirmed COVID-19 test by RT-PCR at SMS Hospitals, Jaipur were assessed. Among the confirmed cases, most of patients were young adults in the fifth and sixth decade of age group with mean age of 50.40 years. There was a male preponderance (59% male and 41% female). Out of total analyzed patients, 39 patients (48.75%) were symptomatic, among them fever (79.47%), cough (74.35%), shortness of breath (36%) and sore throat (17.94%) were the most common presenting clinical manifestations. A few patients (12.82%) also had other symptoms like headache, chest pain, pain abdomen, altered sensorium etc. 54% patients had some underlying co morbid disease in sample population. The most prevalent comorbidities were Diabetes mellitus (56%), Hypertension (48.83%), COPD/K-chest (12%), CAD (9.32%) and others (11.62%) like hypothyroidism, anemia, CVA etc. The lung pathological changes were evaluated by HRCT imaging and by assigning CT severity score. We found Typical COVID findings in 50% patients, Indeterminate in 11%, Atypical in 11% and 28% patients had Negative CT chest for COVID. The clinical status of patients correlated with the CT severity score, with mild cases showing score <15/25 in 45.83% patients and severe cases showing CT severity score >15/25 in 87.50% patients. The CT features varied with duration and course of disease. Proportional GGO was higher (59.37%) in early phase and it was lower (12.5%) in later stage of disease. CONCLUSION: The varied spectra of COVID-19 presentation included fever, cough, shortness of breath, sore throat etc. Diabetes mellitus, hypertension, COPD/K-Chest and CAD were found as major comorbid conditions. Symptomatic presentation of COVID-19 was observed to be higher in patients with co morbid disease, especially if multiple. HRCT chest in COVID-19 patients had a major diagnostic and prognostic importance as positive CT findings were more prominent in symptomatic patients and co-morbid patients. Clinical symptoms of patients directly correlated with CT severity index. CT imaging was found to be useful in predicting clinical recovery of patients or progression of disease.

Intraoral Soft Tissue Fibrosarcoma in a Four-Year-Old Child: An Unusual Case Report.

Fibrosarcoma is a rare soft tissue tumor of connective tissue origin that includes about 0.05% of all the malignancies in the head and neck region of which almost 23% is seen in the oral cavity. This paper describes a rare case of 4-year-old boy who presented with swelling on the right side of face diagnosed as soft tissue fibrosarcoma of the intraoral region. The histopathological and immunohistochemistry confirmed the diagnosis by the presence of spindle-shaped cells arranged in fascicles with mitotic figures and cellular proliferation reproducing fibroblasts. The patient was successfully treated with combination of chemotherapy and surgery with a good clinical outcome. This case report is presented to highlight the rarity of fibrosarcoma in orofacial region of children which requires special attention of pediatric dentist and should be considered as differential diagnose of soft tissue mass in orofacial region of children. Clinical and histopathological features must be correlated with immunohistochemistry in the final diagnosis in fibrosarcoma.

Cloning and characterization of norbelladine synthase catalyzing the first committed reaction in Amaryllidaceae alkaloid biosynthesis.

BACKGROUND: Amaryllidaceae alkaloids (AAs) are a large group of plant-specialized metabolites displaying an array of biological and pharmacological properties. Previous investigations on AA biosynthesis have revealed that all AAs share a common precursor, norbelladine, presumably synthesized by an enzyme catalyzing a Mannich reaction involving the condensation of tyramine and 3,4-dihydroxybenzaldehyde. Similar reactions have been reported. Specifically, norcoclaurine synthase (NCS) which catalyzes the condensation of dopamine and 4-hydroxyphenylacetaldehyde as the first step in benzylisoquinoline alkaloid biosynthesis. RESULTS: With the availability of wild daffodil (Narcissus pseudonarcissus) database, a transcriptome-mining search was performed for NCS orthologs. A candidate gene sequence was identified and named norbelladine synthase (NBS). NpNBS encodes for a small protein of 19 kDa with an anticipated pI of 5.5. Phylogenetic analysis showed that NpNBS belongs to a unique clade of PR10/Bet v1 proteins and shared 41% amino acid identity to opium poppy NCS1. Expression of NpNBS cDNA in Escherichia coli produced a recombinant enzyme able to condense tyramine and 3,4-DHBA into norbelladine as determined by high-resolution tandem mass spectrometry. CONCLUSIONS: Here, we describe a novel enzyme catalyzing the first committed step of AA biosynthesis, which will facilitate the establishment of metabolic engineering and synthetic biology platforms for the production of AAs.

The Chromatin Protein DUET/MMD1 Controls Expression of the Meiotic Gene TDM1 during Male Meiosis in Arabidopsis.

Meiosis produces haploid cells essential for sexual reproduction. In yeast, entry into meiosis activates transcription factors which trigger a transcriptional cascade that results in sequential co-expression of early, middle and late meiotic genes. However, these factors are not conserved, and the factors and regulatory mechanisms that ensure proper meiotic gene expression in multicellular eukaryotes are poorly understood. Here, we report that DUET/MMD1, a PHD finger protein essential for Arabidopsis male meiosis, functions as a transcriptional regulator in plant meiosis. We find that DUET-PHD binds H3K4me2 in vitro, and show that this interaction is critical for function during meiosis. We also show that DUET is required for proper microtubule organization during meiosis II, independently of its function in meiosis I. Remarkably, DUET protein shows stage-specific expression, confined to diplotene. We identify two genes TDM1 and JAS with critical functions in cell cycle transitions and spindle organization in male meiosis, as DUET targets, with TDM1 being a direct target. Thus, DUET is required to regulate microtubule organization and cell cycle transitions during male meiosis, and functions as a direct transcription activator of the meiotic gene TDM1. Expression profiling showed reduced expression of a subset comprising about 12% of a known set of meiosis preferred genes in the duet mutant. Our results reveal the action of DUET as a transcriptional regulator during male meiosis in plants, and suggest that transcription of meiotic genes is under stagewise control in plants as in yeast.

Haloarchaea: worth exploring for their biotechnological potential.

Halophilic archaea are unique microorganisms adapted to survive under high salt conditions and biomolecules produced by them may possess unusual properties. Haloarchaeal metabolites are stable at high salt and temperature conditions that are useful for industrial applications. Proteins and enzymes of this group of archaea are functional under salt concentrations at which bacterial counterparts fail to be active. Such properties makes haloarchaeal enzymes suitable for salt-based applications and their use under dehydrating conditions. For example, bacteriorhodopsin or the purple membrane protein present in halophilic archaea has the most recognizable applications in photoelectric devices, artificial retinas, holograms etc. Haloarchaea are also useful for bioremediation of polluted hypersaline areas. Polyhydroxyalkanoates and exopolysccharides produced by these microorganisms are biodegradable and have the potential to replace commercial non-degradable plastics and polymers. Moreover, halophilic archaea have excellent potential to be used as drug delivery systems and for nanobiotechnology by virtue of their gas vesicles and S-layer glycoproteins. Despite of possible applications of halophilic archaea, laboratory-to-industrial transition of these potential candidates is yet to be established.

Antimicrobial Resistance in Salmonella in the United States from 1948 to 1995.

We conducted a retrospective study of 2,149 clinicalSalmonellastrains to help document the historical emergence of antimicrobial resistance. There were significant increases in resistance to older drugs, including ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline, which were most common inSalmonella entericaserotype Typhimurium. An increase in multidrug resistance was observed for each decade since the 1950s. These data help show howSalmonellaevolved over the past 6 decades, after the introduction of new antimicrobial agents.

Investigating the Role of Helicobacter pylori PriA Protein.

BACKGROUND: In bacteria, PriA protein, a conserved DEXH-type DNA helicase, plays a central role in replication restart at stalled replication forks. Its unique DNA binding property allows it to recognize and stabilize stalled forks and the structures derived from them. PriA plays a very critical role in replication fork stabilization and DNA repair in E. coli and N. gonorrhoeae. In our in vivo expression technology screen, priA gene was induced in vivo when Helicobacter pylori infects mouse stomach. MATERIALS AND METHODS: We decided to elucidate the role of H. pylori PriA protein in survival in mouse stomach, survival in gastric epithelial cells and macrophage cells, DNA repair, acid stress, and oxidative stress. RESULTS: The priA null mutant strain was unable to colonize mice stomach mucosa after long-term infections. Mouse colonization was observed after 1 week of infection, but the levels were much lower than the wild-type HpSS1 strain. PriA protein was found to be important for intracellular survival of epithelial cell-/macrophage cell-ingested H. pylori. Also, a priA null mutant was more sensitive to DNA-damaging agents and was much more sensitive to acid and oxidative stress as compared to the wild-type strain. CONCLUSIONS: These data suggest that the PriA protein is needed for survival and persistence of H. pylori in mice stomach mucosa.