Expression of CXCL8 (IL-8) in the Pathogenesis of T-Cell Acute Lymphoblastic Leukemia Patients.

Background Inflammation plays a very important role in the pathogenesis of a wide range of diseases, such as atherosclerosis myocardial infarction, sepsis, rheumatoid arthritis, and cancer. This study aimed to investigate the association of IL-8 in T-cell acute lymphoblastic leukemia (T-ALL) patients. Methodology IL-8 levels were estimated in 52 individuals. Of the study population, 26 were T-ALL patients (all phases of leukemia were included in the study) and 26 were disease-free healthy volunteers. In this study, we employed flow cytometry, enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction test, and western blot analysis. Results IL-8 was significantly higher in all T-ALL patients than in healthy volunteers. IL-8 levels showed a significant positive correlation in T-ALL patients at the genomic and proteomic levels. Conclusions Higher serum IL-8 levels were associated with the advanced disease stage of the clinicopathological parameters. Our results indicate that monitoring IL-8 has a role in modulating disease sensing in T-ALL and may represent a target for innovative diagnostic and therapeutic strategies.

Plasma Levels of Organochlorine Pesticides and Tumor Necrosis Factor-Alpha: A Potential Risk Factor for Developing Acquired Aplastic Anemia in the North Indian Population.

Background Pesticide exposure might have a contributory role in the development of acquired aplastic anemia (AA). However, the precise mechanisms of pesticide-induced AA remain unknown. In this case-control study, we conducted a comparative analysis of plasma levels of organochlorine pesticides (OCP) and tumor necrosis factor-alpha (TNF-alpha) between Indian patients diagnosed with AA and an age- and sex-matched control group. Methods This is an observational case-control study conducted at a tertiary care hospital in North India. In this study, 90 subjects were included, out of which 45 were diagnosed with AA according to the criteria of the International Agranulocytosis and Aplastic Anemia Study. Cases were compared with 45 controls. A trained interviewer gave all study subjects a questionnaire to collect data regarding demographic details, exposure to pesticides, and clinical history. Physical examination and routine laboratory investigations of each subject were performed. Both cases and controls were tested for their plasma levels of organochlorines as per established protocol by gas chromatography-mass spectrometry. TNF-alpha level was measured by enzyme-linked immunosorbent assay in each subject. Results There was a significant increase in plasma levels of delta hexachlorocyclohexane (delta HCH) (p = 0.02) and heptachlor (p = 0.00) in patients with AA as compared to controls. We observed nonsignificant trends towards higher levels of beta HCH (p = 0.643), aldrin (p = 0.399), and p,p'-Dichlorodiphenyltrichloroethane (p,p'-DDT) (p = 0.453) in patients with AA when compared to the controls. There were significantly higher TNF-alpha levels (p = 0.024) in cases as compared to the controls. Conclusion Our study concludes that patients with AA exhibited higher levels of delta-HCH, heptachlor, and TNF-alpha in comparison to the control group. There is a significant positive correlation of TNF alpha with OCPs (alpha HCH, lindane, delta HCH, heptachlor, aldrin, p,p'- DDD, and methoxychlor pesticides). These organochlorines may have accumulated in the fatty tissue of bone marrow because of their lipophilic nature. This suggests that they might have served as a neoantigen to trigger an increase in TNF-alpha production, which may have led to disrupted bone marrow function through cell-mediated immunity, leading to AA.

Re-emerging human monkeypox: A major public-health debacle.

A multicountry outbreak of the monkeypox virus has gained global attention. As of May 25, 250 confirmed human monkeypox cases have been reported globally. Monkeypox is caused by the Monkeypox virus, which belongs to the Orthopoxvirus genus and Poxviridae family. Monkeypox is often a self-limiting infection, with symptoms lasting 2-4 weeks with the case fatality ratio around 3%-6%. Monkeypox is transmitted to humans by direct contact with an infected person or animal or contact with virus-contaminated material. Human monkeypox infections may lead to various medical complications such as fever, rash, and lymphadenopathies. Pneumonitis, encephalitis, sight-threatening keratitis, and subsequent bacterial infections are all possible complications of monkeypox. An antiviral agent developed to treat smallpox has also been approved for use in the treatment of monkeypox in the United States. Vaccines used in the smallpox eradication program also provided immunity to monkeypox. Newer vaccines have been developed, one of which has been approved for monkeypox prevention. In this study, we provide information about the recent outbreaks of human monkeypox, epidemiology, transmission pattern, possible diagnosis techniques, therapeutics, and available preventive strategies.

Tracing the origin of Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2): A systematic review and narrative synthesis.

The aim of the study was to trace and understand the origin of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through various available literatures and accessible databases. Although the world enters the third year of the coronavirus disease 2019 pandemic, health and socioeconomic impacts continue to mount, the origin and mechanisms of spill-over of the SARS-CoV-2 into humans remain elusive. Therefore, a systematic review of the literature was performed that showcased the integrated information obtained through manual searches, digital databases (PubMed, CINAHL, and MEDLINE) searches, and searches from legitimate publications (1966-2022), followed by meta-analysis. Our systematic analysis data proposed three postulated hypotheses concerning the origin of the SARS-CoV-2, which include zoonotic origin (Z), laboratory origin (L), and obscure origin (O). Despite the fact that the zoonotic origin for SARS-CoV-2 has not been conclusively identified to date, our data suggest a zoonotic origin, in contrast to some alternative concepts, including the probability of a laboratory incident or leak. Our data exhibit that zoonotic origin (Z) has higher evidence-based support as compared to laboratory origin (L). Importantly, based on all the studies included, we generated the forest plot with 95% confidence intervals (CIs) of the risk ratio estimates. Our meta-analysis further supports the zoonotic origin of SARS/SARS-CoV-2 in the included studies.

ß-Lactam Resistance in Azospirillum baldaniorum Sp245 Is Mediated by Lytic Transglycosylase and ß-Lactamase and Regulated by a Cascade of RpoE7→RpoH3 Sigma Factors.

Bacterial resistance to ß-lactam antibiotics is often mediated by ß-lactamases and lytic transglycosylases. Azospirillum baldaniorum Sp245 is a plant-growth-promoting rhizobacterium that shows high levels of resistance to ampicillin. Investigating the molecular basis of ampicillin resistance and its regulation in A. baldaniorum Sp245, we found that a gene encoding lytic transglycosylase (Ltg1) is organized divergently from a gene encoding an extracytoplasmic function (ECF) σ factor (RpoE7) in its genome. Inactivation of rpoE7 in A. baldaniorum Sp245 led to increased ability to form cell-cell aggregates and produce exopolysaccharides and biofilm, suggesting that rpoE7 might contribute to antibiotic resistance. Inactivation of ltg1 in A. baldaniorum Sp245, however, adversely affected its growth, indicating a requirement of Ltg1 for optimal growth. The expression of rpoE7, as well that of as ltg1, was positively regulated by RpoE7, and overexpression of RpoE7 conferred ampicillin sensitivity to both the rpoE7::km mutant and its parent. In addition, RpoE7 negatively regulated the expression of a gene encoding a ß-lactamase (bla1). Out of the 5 paralogs of RpoH encoded in the genome of A. baldaniorum Sp245, RpoH3 played major roles in conferring ampicillin sensitivity and in the downregulation of bla1. The expression of rpoH3 was positively regulated by RpoE7. Collectively, these observations reveal a novel regulatory cascade of RpoE7-RpoH3 σ factors that negatively regulates ampicillin resistance in A. baldaniorum Sp245 by controlling the expression of a ß-lactamase and a lytic transglycosylase. In the absence of a cognate anti-sigma factor, addressing how the activity of RpoE7 is regulated by ß-lactams will unravel new mechanisms of regulation of ß-lactam resistance in bacteria. IMPORTANCE Antimicrobial resistance is a global health problem that requires a better understanding of the mechanisms that bacteria use to resist antibiotics. Bacteria inhabiting the plant rhizosphere are a potential source of antibiotic resistance, but their mechanisms controlling antibiotic resistance are poorly understood. A. baldaniorum Sp245 is a rhizobacterium that is known for its characteristic resistance to ampicillin. Here, we show that an AmpC-type ß-lactamase and a lytic transglycosylase mediate resistance to ampicillin in A. baldaniorum Sp245. While the gene encoding lytic transglycosylase is positively regulated by an ECF σ-factor (RpoE7), a cascade of RpoE7 and RpoH3 σ factors negatively regulates the expression of ß-lactamase. This is the first evidence showing involvement of a regulatory cascade of σ factors in the regulation of ampicillin resistance in a rhizobacterium.

Transmission dynamics and mutational prevalence of the novel Severe acute respiratory syndrome coronavirus-2 Omicron Variant of Concern.

The novel Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variant, Omicron (PANGO lineage B.1.1.529) is being reported from all around the world. The WHO has categorized Omicron as a Variant of Concern (VOC) considering its higher transmissibility and infectivity, vaccine breakthrough cases. As of January 6, 2022, Omicron has been reported in at least 149 countries. Therefore, this study was planned to investigate the transmission dynamics and mutational prevalence of the novel SARS-CoV-2 Omicron variant. The transmission dynamics and Omicron SARS-CoV-2 divergence was studied using GISAID and Nextstrain which provides information about the genetic sequences, epidemiological, geographical, and species-specific data of human, avian, and animal viruses. Further, the mutation prevalence in spike glycoprotein of Omicron was studied, and the frequency of the crucial mutations was compared with the other prevalent VOCs. The transmission dynamics suggest that the Omicron was first identified in South Africa and then it was reported in the United Kingdom followed by the United States and Australia. Further, our phylogenetic analysis suggests that Omicron (BA.1) was clustered distinctly from the other VOCs. In the Spike glycoprotein, the Omicron (B.1.1.529) demonstrates critical 32 amino acid changes. This study may help us to understand mutational hotspots, transmission dynamics, phylogenetic divergence, effect on testing and immunity, which shall promote the progress of the clinical application and basic research.

Characterization of the novel SARS-CoV-2 Omicron (B.1.1.529) variant of concern and its global perspective.

As the latest identified novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concern (VOC), the influence of Omicron on our globe grows promptly. Compared with the last VOC (Delta variant), more mutations were identified, which may address the characteristics of Omicron. Considering these crucial mutations and their implications including an increase in transmissibility, COVID-19 severity, and reduction of efficacy of currently available diagnostics, vaccines, and therapeutics, Omicron has been classified as one of the VOC. Notably, 15 of these mutations reside in the receptor-binding domain of spike glycoprotein, which may alter transmissibility, infectivity, neutralizing antibody escape, and vaccine breakthrough cases of COVID-19. Therefore, our present study characterizes the mutational hotspots of the Omicron variant in comparison with the Delta variant of SARS-CoV-2. Furthermore, detailed information was analyzed to characterize the global perspective of Omicron, including transmission dynamic, effect on testing, and immunity, which shall promote the progress of the clinical application and basic research. Collectively, our data suggest that due to continuous variation in the spike glycoprotein sequences, the use of coronavirus-specific attachment inhibitors may not be the current choice of therapy for emerging SARS-CoV-2 VOCs. Hence, we need to proceed with a sense of urgency in this matter.

Progress and Challenges Toward Generation and Maintenance of Long-Lived Memory T Lymphocyte Responses During COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing the coronavirus disease 2019 (COVID-19) pandemic is a serious global threat until we identify the effective preventive and therapeutic strategies. SARS-CoV-2 infection is characterized by various immunopathological consequences including lymphocyte activation and dysfunction, lymphopenia, cytokine storm, increased level of neutrophils, and depletion and exhaustion of lymphocytes. Considering the low level of antibody-mediated protection during coronavirus infection, understanding the role of T cell for long-term protection is decisive. Both CD4+ and CD8+ T cell response is imperative for cell-mediated immune response during COVID-19. However, the level of CD8+ T cell response reduced to almost half as compared to CD4+ after 6 months of infection. The long-term protection is mediated via generation of immunological memory response during COVID-19. The presence of memory CD4+ T cells in all the severely infected and recovered individuals shows that the memory response is predominated by CD4+ T cells. Prominently, the antigen-specific CD4+ and CD8+ T cells are specifically observed during day 0 to day 28 in COVID-19-vaccinated individuals. However, level of antigen-specific T memory cells in COVID-19-vaccinated individuals defines the long-term protection against forthcoming outbreaks of SARS-CoV-2.

Trichobezoar without a clear manifestation of trichotillomania.

Trichophagia is a compulsive condition characterized by eating hair, mostly seen in adolescent females. Persistence of ingestion of hair over many years results in the formation of trichobezoar. Surgical intervention is often needed in the management of large trichobezoars. We present a case of a 23 year old female with trichophagia which led to the formation of gastric trichobezoar. The patient reported with complaints of pain in abdomen for past 1-2 years, and loss of appetite and vomiting post meals for 6 months. On detailed examination, a diagnosis of trichobezoar was formed which was removed by laparotomy with gastrotomy under general anaesthesia. Psychiatric evaluation revealed a history of fluctuating mood symptoms during her childhood and depressive symptomatology presently without any associated urge of plucking hair and subsequent gratification. Hence, the management of the disease requires proper liaison between the surgeon, psychiatrist, and caregivers of the patient; and regular psychiatric follow-up and treatment of the underlying psychopathology to prevent the recurrent formation of bezoar.

Essential Thrombocythemia Presenting with Recurrent Priapism: A Case Report and Review of Literature.

BACKGROUND Priapism is rarely reported as a complication in patients with essential thrombocythemia at presentation. We could find very few such cases of essential thrombocythemia while searching the literature. A combined modality of treatment is used in the form of chemotherapy and procedures like repeated aspiration and instillation of phenylephrine to treat essential thrombocythemia presenting with recurrent priapism. CASE REPORT A 31-year-old man presented to the Urology Department with priapism for the last 24 h. He had previously had multiple similar episodes in the last 20 days and 1 episode of prolonged penile erection 5 months ago. On examination, his penis was erect, swollen, and painful. There was no organomegaly. The priapism was managed with repeated aspiration and instillation of phenylephrine. Routine investigations showed marked thrombocytosis. Subsequent investigations done in the Clinical Hematology Department revealed increased megakaryocytes in bone marrow and presence of JAK2V617F mutation. After confirmation of diagnosis, cytoreductive therapy (hydroxyurea 500 mg twice a day) and acetyl salicylic acid 75 mg once a day was initiated. With this treatment, the platelet count normalized over a period of 2 months and no further episodes of priapism were noted; however, the patient developed erectile dysfunction. CONCLUSIONS Essential thrombocythemia can present with priapism as the first manifestation. Early suspicion, diagnosis, and management is needed to prevent erectile dysfunction. Erectile dysfunction is usually irreversible after long-standing priapism.

Down-Regulation of the Alternative Sigma Factor SigJ Confers a Photoprotective Phenotype to Anabaena PCC 7120.

Alternative sigma factors belonging to Group 3 are thought to play an important role in the adaptation of cyanobacteria to environmental challenges by altering expression of genes needed for coping with such stresses. In this study, the role of an alternative sigma factor, SigJ, was analyzed in the filamentous nitrogen-fixing cyanobacterium, Anabaena sp. PCC 7120 by knocking down the expression of the sigJ gene (alr0277) employing an antisense RNA-mediated approach. In the absence of any stress, the knock-down (KD0277) or the wild-type strain both grew similarly. Upon exposure to high-intensity light, KD0277 showed substantially reduced bleaching of its pigments, higher photosynthetic activity and consequently better survival than the wild type. KD0277 also showed an enhanced accumulation of two carotenoids, which were identified as myxoxanthophyll and keto-myxoxanthophyll. Further, KD0277 was more tolerant to ammonium-triggered photodamage than the wild type. Moreover, PSII was better protected against photodamage in KD0277 than in the wild type. Down-regulation of sigJ in Anabaena PCC 7120, however, reduced its ability to cope with desiccation. This study demonstrates that down-regulation of the sigJ gene in Anabaena PCC 7120 differentially affects its ability to tolerate two environmentally relevant stresses, i.e. high-intensity light and desiccation.

Association of TNF-α -308G>A and TNF-ß +252A>G genes polymorphisms with primary immune thrombocytopenia: a North Indian study.

Primary immune thrombocytopenia (ITP) is manifested by platelet autoantibodies that are not only responsible for platelet destruction by phagocytosis but also inhibit their production. Bleeding is the most common clinical manifestation of thrombocytopenia. ITP is a multifactorial disease in which both environmental and genetic factors have been implicated. It has been reported that several gene polymorphisms influence host susceptibility to ITP. This study was aimed to investigate the association of polymorphisms in tumor necrosis factor-alpha (TNF-α) 308 G>A and TNF-ß +252 A>G genes with primary ITP in Indian patients. Genotyping for the TNF-α -308 G>A and TNF-ß +252 A>G was performed in 80 ITP patients and 100 controls by polymerase chain reaction and restriction fragment length polymorphism. We found no significant difference in distribution of TNF-α heterozygous variant genotype (GA) among patients and controls. Homozygous variant genotype (AA) was absent both in patients and controls. No statistical difference was observed in the distribution of heterozygous variant (AG) and homozygous variant (GG) genotypes of TNF-ß, between patients and controls. Heterozygous (AG) genotype of TNF-ß -308G>A was associated with persistent ITP. The study showed that heterozygous variant (AG) genotype of TNF-ß was associated with persistent ITP, when compared with controls. We could not find any association of TNF-α with susceptibility in developing ITP. Furthermore, no association was observed with respect to different categories of ITP. In addition, additive model showed two-fold increased susceptibility to ITP. We conclude that single nucleotide polymorphism in TNF-ß +252 A>G gene may have impact on susceptibility to ITP.

An invasive Mimosa in India does not adopt the symbionts of its native relatives.

BACKGROUND AND AIMS: The large monophyletic genus Mimosa comprises approx. 500 species, most of which are native to the New World, with Central Brazil being the main centre of radiation. All Brazilian Mimosa spp. so far examined are nodulated by rhizobia in the betaproteobacterial genus Burkholderia. Approximately 10 Mya, transoceanic dispersal resulted in the Indian subcontinent hosting up to six endemic Mimosa spp. The nodulation ability and rhizobial symbionts of two of these, M. hamata and M. himalayana, both from north-west India, are here examined, and compared with those of M. pudica, an invasive species. METHODS: Nodules were collected from several locations, and examined by light and electron microscopy. Rhizobia isolated from them were characterized in terms of their abilities to nodulate the three Mimosa hosts. The molecular phylogenetic relationships of the rhizobia were determined by analysis of 16S rRNA, nifH and nodA gene sequences. KEY RESULTS: Both native Indian Mimosa spp. nodulated effectively in their respective rhizosphere soils. Based on 16S rRNA, nifH and nodA sequences, their symbionts were identified as belonging to the alphaproteobacterial genus Ensifer, and were closest to the 'Old World' Ensifer saheli, E. kostiensis and E. arboris. In contrast, the invasive M. pudica was predominantly nodulated by Betaproteobacteria in the genera Cupriavidus and Burkholderia. All rhizobial strains tested effectively nodulated their original hosts, but the symbionts of the native species could not nodulate M. pudica. CONCLUSIONS: The native Mimosa spp. in India are not nodulated by the Burkholderia symbionts of their South American relatives, but by a unique group of alpha-rhizobial microsymbionts that are closely related to the 'local' Old World Ensifer symbionts of other mimosoid legumes in north-west India. They appear not to share symbionts with the invasive M. pudica, symbionts of which are mostly beta-rhizobial.

An extracytoplasmic function sigma factor cotranscribed with its cognate anti-sigma factor confers tolerance to NaCl, ethanol and methylene blue in Azospirillum brasilense Sp7.

Azospirillum brasilense, a plant-growth-promoting rhizobacterium, is exposed to changes in its abiotic environment, including fluctuations in temperature, salinity, osmolarity, oxygen concentration and nutrient concentration, in the rhizosphere and in the soil. Since extra-cytoplasmic function (ECF) sigma factors play an important role in stress adaptation, we analysed the role of ECF sigma factor (also known as RpoE or σ(E)) in abiotic stress tolerance in A. brasilense. An in-frame rpoE deletion mutant of A. brasilense Sp7 was carotenoidless and slow-growing, and was sensitive to salt, ethanol and methylene blue stress. Expression of rpoE in the rpoE deletion mutant complemented the defects in growth, carotenoid biosynthesis and sensitivity to different stresses. Based on data from reverse transcriptase-PCR, a two-hybrid assay and a pull-down assay, we present evidence that rpoE is cotranscribed with chrR and the proteins synthesized from these two overlapping genes interact with each other. Identification of the transcription start site by 5' rapid amplification of cDNA ends showed that the rpoE-chrR operon was transcribed by two promoters. The proximal promoter was less active than the distal promoter, whose consensus sequence was characteristic of RpoE-dependent promoters found in alphaproteobacteria. Whereas the proximal promoter was RpoE-independent and constitutively expressed, the distal promoter was RpoE-dependent and strongly induced in response to stationary phase and elevated levels of ethanol, salt, heat and methylene blue. This study shows the involvement of RpoE in controlling carotenoid synthesis as well as in tolerance to some abiotic stresses in A. brasilense, which might be critical in the adaptation, survival and proliferation of this rhizobacterium in the soil and rhizosphere under stressful conditions.

Gene encoding gamma-carbonic anhydrase is cotranscribed with argC and induced in response to stationary phase and high CO2 in Azospirillum brasilense Sp7.

BACKGROUND: Carbonic anhydrase (CA) is a ubiquitous enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. Gamma class carbonic anhydrases (gamma-CAs) are widespread in prokaryotes but their physiological roles remain elusive. At present, only gamma-CA of Methanosarcina thermophila (Cam) has been shown to have CA activity. Genome analysis of a rhizobacterium Azospirillum brasilense, revealed occurrence of ORFs encoding one beta-CA and two gamma-CAs. RESULTS: One of the putative gamma-CA encoding genes of A. brasilense was cloned and overexpressed in E. coli. Electrometric assays for CA activity of the whole cell extracts overexpressing recombinant GCA1 did not show CO2 hydration activity. Reverse transcription-PCR analysis indicated that gca1 in A. brasilense is co-transcribed with its upstream gene annotated as argC, which encodes a putative N-acetyl-gamma-glutamate-phosphate reductase. 5'-RACE also demonstrated that there was no transcription start site between argC and gca1, and the transcription start site located upstream of argC transcribed both the genes (argC-gca1). Using transcriptional fusions of argC-gca1 upstream region with promoterless lacZ, we further demonstrated that gca1 upstream region did not have any promoter and its transcription occurred from a promoter located in the argC upstream region. The transcription of argC-gca1 operon was upregulated in stationary phase and at elevated CO2 atmosphere. CONCLUSIONS: This study shows lack of CO2 hydration activity in a recombinant protein expressed from a gene predicted to encode a gamma-carbonic anhydrase in A. brasilense although it cross reacts with anti-Cam antibody raised against a well characterized gamma-CA. The organization and regulation of this gene along with the putative argC gene suggests its involvement in arginine biosynthetic pathway instead of the predicted CO2 hydration.

Regulation of expression and biochemical characterization of a beta-class carbonic anhydrase from the plant growth-promoting rhizobacterium, Azospirillum brasilense Sp7.

Carbonic anhydrase (CA; [EC 4.2.1.1]) is a ubiquitous enzyme catalysing the reversible hydration of CO(2) to bicarbonate, a reaction that supports various biochemical and physiological functions. Genome analysis of Azospirillum brasilense, a nonphotosynthetic, nitrogen-fixing, rhizobacterium, revealed an ORF with homology to beta-class carbonic anhydrases (CAs). Biochemical characteristics of the beta-class CA of A. brasilense, analysed after cloning the gene (designated as bca), overexpressing in Escherichia coli and purifying the protein by affinity purification, revealed that the native recombinant enzyme is a homotetramer, inhibited by the known CA inhibitors. CA activity in A. brasilense cell extracts, reverse transcriptase (RT)-PCR and Western blot analyses showed that bca was constitutively expressed under aerobic conditions. Lower beta-galactosidase activity in A. brasilense cells harbouring bca promoter: lacZ fusion during the stationary phase or during growth on 3% CO(2) enriched air or at acidic pH indicated that the transcription of bca was downregulated by the stationary phase, elevated CO(2) levels and acidic pH conditions. These observations were also supported by RT-PCR analysis. Thus, beta-CA in A. brasilense seems to be required for scavenging CO(2) from the ambient air and the requirement of CO(2) hydration seems to be higher for the cultures growing exponentially at neutral to alkaline pH.

Biodegradation of trichloroethylene (TCE) by methanotrophic community.

Laboratory incubation experiments were carried out to assess the potential of methanotrophic culture for degrading TCE. Measurements of the growth rate and TCE degradation showed that the methanotrophs not only grew in presence of TCE but also degraded TCE. The rate of TCE degradation was found to be 0.19 ppm h(-1). The reverse transcriptase-PCR test was conducted to quantify expression of pmoA and mmoX genes. RT-PCR revealed expression of pmoA gene only. This observation provides evidence that the pmoA gene was functionally active for pMMO enzyme during the study. The diversity of the methanotrophs involved in TCE degradation was assessed by PCR amplification, cloning, restriction fragment length polymorphism and phylogenetic analysis of pmoA genes. Results suggested the occurrence of nine different phylotypes belonging to Type II methanotrophs in the enriched cultures. Out of the nine, five clustered with, genera Methylocystis and rest got clustered in to a separate group.

Studies on biomarkers for oxidative stress in patients with chronic myeloid leukemia.

BACKGROUND: Chronic myeloid leukemia (CML) is a myeloproliferative disorder with a unique genetic rearrangement, the Philadelphia chromosome. High reactive oxygen species (ROS) levels favor oxidative stress, which could play a vital role in normal processes and various pathophysiologies including neoplasm. Biomarkers of oxidative stress are measured as products of oxidized proteins and lipids. Plasma levels of protein carbonyl (PC), thiobarbituric acid reactive substances (TBARS) and total lipid hydroperoxide (LOOH) were used as biomarkers of oxidative stress in the past. The aim of this study was to evaluate the products of protein oxidation and lipid peroxidation in plasma as biomarkers of oxidative stress in CML patients. PATIENTS AND METHODS: The study included 40 CML patients and 20 age- and sex-matched healthy volunteers. Of 40 CML patients, 28 were in chronic phase (CML-CP) and 12 in accelerated phase (CML-AP). Plasma levels of PC, TBARS and LOOH as biomarkers of oxidative stress were evaluated by spectrophotometric methods. RESULTS: There were significant differences (P < .05) in plasma levels of PC, TBARS and LOOH in CML, CML-CP and CML-AP patients as compared to controls. CONCLUSION: PC, TBARS and LOOH might reflect oxidative stress in CML patients and might be used as biomarkers in such patients.

Mutation in a gene encoding anti-sigma factor in A. brasilense confers tolerance to elevated temperature, antibacterial peptide and PEG-200 via carotenoid synthesis.

Azospirillum brasilense Sp7 has been shown to overproduce carotenoids if the anti-sigma factor (anti-sigma(E))-encoding gene is inactivated. The anti-sigma mutant (Car-1) of A. brasilense Sp7 was more tolerant to the stresses generated by elevated temperature (40 degrees C), PEG-200 (30 mg mL(-1)) and the antibacterial agent Polymyxin-B (PMB, 25 microg mL(-1)) but not to elevated salinity (15 mg mL(-1)). Inhibition of carotenoid synthesis by diphenylamine inhibited the ability of the mutant to tolerate all the three stresses. Out of the four stress agents, only elevated temperature and salinity induced the rpoE promoter and increased the carotenoid content in Sp7 as well as in the Car-1 mutant. Comparison of the membrane permeability of the parent and the mutant by a PMB-N-phenyl-1-naphthylamine coupled assay showed that the presence of carotenoids in the mutant reduced the permeability of their membranes. Our study indicates that the carotenoid synthesis, which is under the control of extracytoplasmic function sigma factor (sigma(E)) in A. brasilense Sp7, plays a positive role in tolerating elevated temperature, the antibacterial peptide and PEG-200.