To Evaluate the Effect of Vitamin B Complex on Wound Healing - A Clinical and Microbiological Study.

Background: The purpose of this study is to explore the effect of vitamin B complex supplementation following periodontal flap surgery on clinical and microbiological parameters. Materials and Methods: A randomized controlled trial on 10 patients with periodontitis in split-mouth design was undertaken to find the effect of vitamin B complex supplementation with open flap debridement on periodontal wound healing. Multiplex polymerase chain reaction (PCR) for Tannerella forsythus and Porphyromonas gingivalis was done using subgingival plaque samples at 0 and 90th day. Results: The results showed a significant reduction (P < 0.01) of clinical (plaque index, gingival index, gingival bleeding index, probing pocket depth, and relative attachment level) and microbial profile in both treatment groups, whereas on intergroup analysis, more reduction in all clinical parameters were observed in the test group, but statistically, the results were insignificant.

Amniotic membrane versus platelet-rich fibrin in treatment of gingival recession- a randomized control trial.

Objective: To determine the efficacy of latelet-rich fibrin (PRF) and Amniotic membrane (AM) along with the coronally advanced flap (CAF) technique in treating Miller's class I gingival recession (GR) defects. Material and methods: A total of 32 sites with Miller's class I GR defects were distributed into Group A (CAF + PRF, n = 16) and Group B (CAF + AM, n = 16). Clinical parameters like gingival index (GI), plaque index (PI), gingival bleeding index (GBI), gingival sulcus depth (GSD), relative attachment level (RAL), and gingival marginal level (GML) were measured at baseline and at 3, 6 and 9 months after surgical intervention. Results: PRF and AM with CAF were effective treatment modalities for treating Miller's class I GR defects, with an average root coverage value of 2.00 ± 0.75 mm in Group A and 1.5 ± 0.3 mm in Group B. Complete coverage (100 %) was obtained in 57 % sites of group A and 49 % sites of group B. At the 9-month follow-up, there was a significant increase in relative attachment levels in both groups when compared to baseline. Conclusion: In the present study it was observed that there was a clinically and statistically significant improvement in root coverage with both groups. PRF-treated sites showed > 50 % complete coverage and hence were superior. AM showed comparable results to PRF and could be used as an alternative.

Variational mode decomposition-based EEG analysis for the classification of disorders of consciousness.

Aberrant alterations in any of the two dimensions of consciousness, namely awareness and arousal, can lead to the emergence of disorders of consciousness (DOC). The development of DOC may arise from more severe or targeted lesions in the brain, resulting in widespread functional abnormalities. However, when it comes to classifying patients with disorders of consciousness, particularly utilizing resting-state electroencephalogram (EEG) signals through machine learning methods, several challenges surface. The non-stationarity and intricacy of EEG data present obstacles in understanding neuronal activities and achieving precise classification. To address these challenges, this study proposes variational mode decomposition (VMD) of EEG before feature extraction along with machine learning models. By decomposing preprocessed EEG signals into specified modes using VMD, features such as sample entropy, spectral entropy, kurtosis, and skewness are extracted across these modes. The study compares the performance of the features extracted from VMD-based approach with the frequency band-based approach and also the approach with features extracted from raw-EEG. The classification process involves binary classification between unresponsive wakefulness syndrome (UWS) and the minimally conscious state (MCS), as well as multi-class classification (coma vs. UWS vs. MCS). Kruskal-Wallis test was applied to determine the statistical significance of the features and features with a significance of p < 0.05 were chosen for a second round of classification experiments. Results indicate that the VMD-based features outperform the features of other two approaches, with the ensemble bagged tree (EBT) achieving the highest accuracy of 80.5% for multi-class classification (the best in the literature) and 86.7% for binary classification. This approach underscores the potential of integrating advanced signal processing techniques and machine learning in improving the classification of patients with disorders of consciousness, thereby enhancing patient care and facilitating informed treatment decision-making.

Contextualizing the experiences of Black pregnant women during the COVID-19 pandemic: 'It's been a lonely ride'.

The emergence of the COVID-19 pandemic significantly changed the prenatal care experience, specifically regarding medical appointments and social opportunities. It is critical to capture this change through the narratives of pregnant people, particularly those of marginalized populations, whose voices may often be underrepresented in the literature. This mixed-methods paper summarizes the experiences of 40 pregnant Black/African American (AA) women during the COVID-19 pandemic. A cross-sectional, online survey was administered between 2020 and 2021 to assess prenatal health and the impacts of the COVID-19 pandemic on patients' pregnancy experience. Coping behaviors during the pandemic were self-reported using the COPE-IS. Univariate analyses were conducted. An additional analysis of participants (n = 4) was explored through a week-long qualitative exercise using a photo documentation procedure. Photo-Elicitation Interviews (PEI) were conducted to capture and center their pandemic pregnancy experiences. Sources of stress during the pandemic varied, with the most common being financial concerns (n = 19, 47.5%). Over half of the sample (n = 18, 54.5%) self-reported increases in their positive coping behaviors during the pandemic, such as communicating with friends and family, talking to healthcare providers, listening to music, and engaging in spiritual practices-such as prayer. The four PEI study participants reflected on the impacts of social distancing on their prenatal experience and mentioned hospital and provider-related weariness due to their race. The findings of this study suggest that during the COVID-19 pandemic, Black/AA pregnant women in Charlotte, NC used social support, mindfulness practices, self-advocacy, and health literacy to navigate challenges present during their prenatal health experience. This paper highlights the personal, social, and structural experiences of pregnant women during a public health crisis so that responsive and effective programs or policies can be planned in the future.

Colorimetric determination of cysteine and copper based on the peroxidase-like activity of Prussian blue nanocubes.

Prussian blue nanocubes were synthesized via a hydrothermal method. Significantly, the redox couple Ni3+/Ni2+ provided rich oxidation and reduction reactions, which enhance catalytic activity. Furthermore, PBNCs mimic peroxidase activity which could oxidise colourless tetramethyl benzidine (TMB) to a blue colour (TMB+) in the presence of H2O2. Thus, it can be used as a colorimetric sensing platform for detecting cysteine and Cu2+. The addition of cysteine to a TMB + PBNCs sensing system decreases the intensity of the blue colour in the solution with a decrease in the absorption peak at 652 nm in the UV visible spectrum. Subsequently, the addition of Cu2+ into the TMB + PBNCs + Cys sensing system increases the intensity of the blue colour due to complex formation of Cu and cysteine. Therefore, the change in intensity of the blue colour of TMB is directly proportional to the concentration of Cys and Cu2+. As a result, this sensing system is highly sensitive and selective with an effective low detection limit of 0.002 mM for cysteine and 0.0181 mM for Cu2+. Furthermore, this method was applied to the detection of cysteine and copper in spiked real samples and gave satisfactory results.

Evaluation of Periodontal Status among Men Undergoing Infertility Treatment.

AIMS: It has been estimated that >30% of male infertility cases are of idiopathic etiology. Recent studies revealed a positive connection between periodontal pockets and sperm submotility, which proposes that periodontitis may have a role in male infertility and inadequate semen quality. The aim of the present investigation was to inspect the relationship between male fertility parameters and the periodontal status of male patients attending in vitro treatment (IVF) clinic. MATERIALS AND METHODS: The study participants comprised 85 men going to the facility for sperm investigation before semen insemination. The nature of sperm was surveyed by the WHO 2010 criteria. On the same day, male patients were examined for periodontal parameters. RESULTS: The patients were determined to have either gingivitis (24.7%) or periodontitis (75.3%). Normospermia was credited to 23.5% and oligozoospermia to 43.5%. Sperm submotility was seen in 76.4% of patients. A higher number of sites with clinical attachment loss showed a positive correlation with sperm submotility and sperm count. CONCLUSIONS: The findings of the present study showed a conceivable relationship between male infertility, decreased semen quality, and periodontal diseases in men visiting IVF centers. Periodontitis may subsequently play a role in male infertility.

Repertoire of noncoding RNAs in corpus luteum of early pregnancy in buffalo (Bubalus bubalis).

AIM: The present study was designed to identify other noncoding RNAs (ncRNAs) in the corpus luteum (CL) during early pregnancy in buffalo. MATERIALS AND METHODS: For this study, CL (n=2) from two buffalo gravid uteri, obtained from the slaughter house, was transported to laboratory after snap freezing in liquid nitrogen (-196°C). The stage of pregnancy was determined by measuring the crown-rump region of the fetus. This was followed by isolation of RNA and deep sequencing. Post-deep sequencing, the obtained reads were checked and aligned against various ncRNA databases (GtRNA, RFAM, and deep guide). Various parameters, namely, frequency of specific ncRNAs, length, mismatch, and genomic location target in several model species were deciphered. RESULTS: Frequency of piwi-interacting RNAs (piwi-RNAs), having target location in rodents and human genomes, were significantly higher compared to other piwi-RNAs and ncRNAs. Ribosomal RNAs (rRNAs) deduced had nucleotides (nts) ranging from 17 to 50 nts, but the occurrence of small length rRNAs was more than lengthier fragments. The target on 16S rRNA species confirms the conservation of 16S rRNA across species. With respect to transfer RNA (tRNA), the abundantly occurring tRNAs were unique with no duplication. Small nucleolar RNAs (snoRNAs), identified in this study, showed a strong tendency for coding box C/D snoRNAs in comparison to H/ACA snoRNAs. Regulatory and evolutionary implications of these identified ncRNAs are yet to be delineated in many species, including buffaloes. CONCLUSION: This is the first report of identification of other ncRNAs in CL of early pregnancy in buffalo.

Identification of microRNAs in corpus luteum of pregnancy in buffalo (Bubalus bubalis) by deep sequencing.

This study was aimed to identify miRNAs of corpus luteum (CL) in buffaloes during pregnancy. For this study, CL (n=2) were collected from gravid uteri of buffalo and RNA was isolated. Following this, the purity and integrity of RNA was checked and used for deep sequencing using Illumina Hiseq 2500 platform. The reads' quality was checked prior to in silico analyses viz. identification of conserved, novel and target of miRNAs. In this study, out of identified miRNAs (3018), 3013 were known and 5 were novel miRNAs on alignment with reference genomes. In addition, prediction of putative target genes for identified abundant miRNAs revealed several genes viz. HOX, KLF4, NCOR2, CDKN2Z, MAPK7, COX2, PPARA, PTEN, ASS3A, ELK1, CASP3, BCL211, MCL1, CCND2, Cyclin A2 and CDC25A during early pregnancy in buffalo. These predicted target genes have been associated with various cellular house-keeping processes including apoptosis. In conclusion, this study reports the identification of conserved and novel microRNAs (miRNAs) in CL during pregnancy in buffalo by deep sequencing.

Retracted: Evaluation of the incidence of microcracks caused by Mtwo and ProTaper NEXT rotary file systems versus the Self Adjusting File: a scanning electron microscopic study.

The following article from International Endodontic Journal, 'Evaluation of the incidence of microcracks caused by Mtwo and ProTaper NEXT rotary file systems versus the Self Adjusting File: a scanning electron microscopic study' by S. G. Saha, N. Vijaywargiya, S. Dubey, D. Saxena & S. Kala, published online on 24 November 2015 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief, Prof. Paul Dummer, and John Wiley & Sons Ltd. The retraction has been agreed due to the consideration that the SEM methodology used by the authors has the potential to cause cracks and is thus is not suitable for the evaluation of micro-cracks in roots.

An evaluation of microbial profile in halitosis with tongue coating using PCR (polymerase chain reaction)- a clinical and microbiological study.

BACKGROUND: Medline search using key words halitosis, tongue coating, polymerase chain reaction, microbial profile did not reveal any study. Hence, the purpose of the present investigation was to assess the malodor using the organoleptic method and tanita device; to quantify odoriferous microorganisms using Polymerase Chain Reaction technique in chronic periodontitis patients. MATERIALS AND METHODS: The study included 30 chronic periodontitis patients. Halitosis was detected using organoleptic assessment & tanita breath alert. Microbial analysis of Pg, Tf & Fn was done using PCR. Plaque index (PI), gingival index (GI), gingival bleeding index (GBI) were recorded. RESULT: The maximum score of 3 for tongue coating was found in 60% of selected subjects. The tanita breath alert measured VSC level of score 2 in 60% of selected subjects while organoleptic score of 4 was found in 50% of subjects. The maximum mean value of 31.1±36.5 was found to be of F. nucleatum (Fn) followed by P. gingivalis (Pg) (13±13.3) & T. forsythia (Tf) (7.16±8.68) in tongue samples of selected patients. A weak positive correlation was found between VSC levels (tanita score & organoleptic score) and clinical parameters. CONCLUSION: The halitosis assessment by measuring VSC levels using organoleptic method and tanita breath alert are clinically feasible. Maximum tongue coating was found in 60% of patients. Fn was found comparatively more than the Pg & Tf. A weak positive correlation was found between VSC levels and clinical parameters such as PI, GI & GBI. Thus,the dentist/ periodontist should emphasise on tongue cleaning measures that would reduce the odoriferous microbial load.

Modulation of haemodynamics, endogeneous antioxidant enzymes, and pathophysiological changes by selective inhibition of angiotensin II type 1 receptors in pressureoverload rats.

BACKGROUND: Constriction of the thoracic or abdominal aorta provides an experimental model of pressure-overload cardiac hypertrophy. Blockade of AT1 receptors is beneficial in preventing target-organ damage in hypertension. OBJECTIVE: To examine the effect of angiotensin II receptor antagonists on blood pressure, endogenous antioxidant enzyme and histopathological changes in pressure-overload rats. METHODS: Pressure overload was produced by abdominal aortic banding (AAB) using a blunt 22-guage needle in male rats as a model of cardiac hypertrophy. After surgery, the AAB-induced hypertension (AABIH) rats were treated with losartan 40 mg/kg/day, candesartan 10 mg/kg/day, irbesartan 10 mg/kg/day per os for 16 weeks. At 16 weeks of surgery, the rats were observed for general characteristics and mortality, and we determined non-invasive blood pressure (NIBP), endogenous antioxidant enzyme catalase and superoxide dismutase (SOD) activities, and histology of the target organs. RESULTS: In the AABIH group, significant increase in systolic blood pressure was observed from weeks 3 to 16 compared with the control group, along with reduced serum catalase and SOD activities. The treated groups showed significant reduction in systolic BP and increase in serum SOD and catalase activities. The histological changes induced in the target organs, namely heart, liver, kidneys and thoracic aorta in the AABIH rats were attenuated in the treated rats. CONCLUSION: Blockade of the AT1 receptor caused an improvement in the myocardial antioxidant reserve and decreased oxidative stress in the hypertensive rats, which was evidenced by the protection observed in the treatment groups.

In vitro culture and morphological characterization of prepubertal buffalo (Bubalus bubalis) putative spermatogonial stem cell.

PURPOSE: Spermatogonial stem cells (SSCs) have the unique ability both to self-renew and to produce progeny that undergo differentiation to spermatozoa. The present study has been carried out to develop a method to purify and enrich the pure populations of spermatogonial stem cell like cells in buffalo. METHODS: The spermatogonial cells were isolated from testes of 3-7 month old buffalo calves and disaggregated by double enzymatic digestion. Mixed population of isolated cells were then plated on Datura stramonium agglutinin (DSA) lectin coated dishes for attachment of Sertoli cells. The desired cells were obtained from suspension medium after 18 h of incubation and then loaded on discontinuous density gradient using percoll (20-65 %) and different types of spermatogonia cells were obtained at interface of each layer. These cells were cultured in vitro. RESULTS: Spermatogonial cells isolated have spherical outline and two or three eccentrically placed nucleoli, created a colony after proliferation during first week or immediately after passage. After 7-10 days of culture, the resulted developed colonies of spermatogonial cells expressed the spermatogonial specific genes like Plzf and VASA; and other pluripotency related markers viz. alkaline phosphtase, DBA, CD9, CD90, SSEA-1, OCT-4, NANOG and REX-1. CONCLUSION: Our results show that the isolated putative spermatogonial stem cells exhibit the expression of pluripotency related and spermatogonial specific genes. This study may help to establish a long term culture system for buffalo spermatogonia.

Detection of odoriferous subgingival and tongue microbiota in diabetic and nondiabetic patients with oral malodor using polymerase chain reaction.

BACKGROUND: Halitosis has been correlated with the concentration of volatile sulfur compounds (VSCs) produced in the oral cavity by metabolic activity of bacteria colonizing the periodontal pockets and the dorsum of the tongue. It has been assumed that there is a relationship between periodontal disease and diabetes mellitus. OBJECTIVES: The aim of the study was to assess the malodor using the organoleptic method and tanita device; to quantify odoriferous microorganisms of subgingival plaque and tongue coating, such as P. gingivalis (Pg), T. forsythia (Tf), and F. nucleatum (Fn) using polymerase chain reaction (PCR) in nondiabetic and diabetic chronic periodontitis patients. PATIENTS AND METHODS: Thirty chronic periodontitis patients (with and without diabetes) with 5-7 mm pocket depth, radiographic evidence of bone loss, and presence of oral malodor participated in this study. Subjective assessment of mouth air was done organoleptically and by using a portable sulfide monitor. Tongue coating was also assessed. RESULTS: The scores of plaque index, gingival index, gingival bleeding index, VSC levels, and tongue coating between the nondiabetic and diabetic patients were not significant (P>0.5). In nondiabetic patients, Fn was found to be significantly (P<0.5) more in tongue samples, whereas Pg and Tf have not shown significant values (P>0.5). In diabetic patients, Fn and Tf have shown significant (P<0.5) an increase in subgingival and tongue samples, respectively, whereas Pg has not shown significant difference between subgingival and tongue samples. INTERPRETATION AND CONCLUSION: The results confirm that there is no difference in clinical parameters between nondiabetic and diabetic periodontitis patients, but the odoriferous microbial profiles in tongue samples of diabetic patients were found to be high. However, there is a weak positive correlation between VSC levels, clinical parameters, and odoriferous microbial profiles.

Modulation of hemodynamics, endogenous antioxidant enzymes, and pathophysiological changes by Angiotensin-converting enzyme inhibitors in pressure-overload rats.

INTRODUCTION: We sought to assess the role of angiotensin-converting enzyme (ACE) inhibitors on systolic blood pressure (BP), endogenous antioxidant enzymes and histopathological changes in pressure-overload rats. METHODS: Pressure overload was produced in male rats by abdominal aortic banding (AAB) using a blunt 22-gauge needle, as a model of cardiac hypertrophy. After surgery, AAB-induced hypertensive (AABIH) groups were treated with captopril 4 mg and ramipril 10 mg/kg per day p.o. for 16 weeks. At 16 weeks, rats were observed for general characteristics and mortality, non-invasive blood pressure (NIBP) and endogenous antioxidant enzyme catalase and superoxide dismutase (SOD) activity and histological evaluation of target organs. RESULTS: In the AABIH group a significant increase in systolic BP was observed in week 3 (149.3 ± 0.821) and persisted until week 16, along with lower levels of serum catalase (144.7 ± 2.204) and SOD (12.92 ± 0.4601) activity compared to the control group. Captopril and ramipril treated groups showed a significantly smaller increase in systolic BP (25.47 ± 3.685, 20.21 ± 3.306) and greater serum SOD (27.33 ± 2.338, 28.95 ± 1.143) and catalase (181.7 ± 8.407, 187.9 ± 8.497) activity, respectively, than the hypertensive rats. The histological changes induced in target organs (heart, liver, kidneys and thoracic aorta) in AABIH rats were attenuated in treated rats. CONCLUSIONS: ACE-inhibition causes an improvement in myocardial antioxidant reserve, reduces oxidative stress, and prevents pathophysiological alterations, while showing a trend for potential target organ protection in hypertensive rats.

Antioxidant, antihyperlipidaemic and antidiabetic activity of eugenia floccosa bedd leaves in alloxan induced diabetic rats.

The ethanol extract of Eugenia floccosa Bedd (Family: Myrtaceae) leaf was investigated for its antioxidant, antihyperlipidaemic and antidiabetic effect in Wistar Albino rats. Diabetes was induced in Albino rats by administration of alloxan monohydrate (150mg/kg, i.p). The ethanol extracts of E. floccosa at a dose of 150 and 300mg/kg of body weight were administered at single dose per day to diabetes induced rats for a period of 14 days. The effect of ethanol extract of E. floccosa leaf extract on blood glucose, plasma insulin, creatinine, glycosylated haemoglobin, urea serum lipid profile [total cholesterol (TR), triglycerides (TG), low density lipoprotein - cholesterol (LDL-C), very low density lipoprotein - cholesterol (VLDL-C), high density lipoprotein - cholesterol (HDL-C) and phospholipid (PL)] serum protein, albumin, globulin, serum enzymes [serum glutamate pyruvate transaminases (SGPT) and serum glutamate oxaloacetate transaminases (SGOT), and alkaline phosphatase (ALP)], lipoprotein peroxidation (LPO) antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH) and glutathione peroxidase (GPx) were measured in the diabetic rats. The ethanol extract of Eugenia floccosa leaf elicited significant reductions of blood glucose (P<0.05), lipid parameters except HDL-C, serum enzymes and significantly increased HDL-C and antioxidant enzymes. The extracts also caused significant increase in plasma insulin (P<0.05) in the diabetic rats. From the above results, it is concluded that ethanol extract of Eugenia floccosa possesses significant antidiabetic, antihyperlipidaemic and antioxidant effects in alloxan induced diabetic rats.

Proton-assisted amino-acid transporters are conserved regulators of proliferation and amino-acid-dependent mTORC1 activation.

The phosphoinositide3-kinase (PI3K)/Akt and downstream mammalian target of rapamycin complex 1 (mTORC1) signalling cascades promote normal growth and are frequently hyperactivated in tumour cells. mTORC1 is also regulated by local nutrients, particularly amino acids, but the mechanisms involved are poorly understood. Unexpectedly, members of the proton-assisted amino-acid transporter (PAT or SLC36) family emerged from in vivo genetic screens in Drosophila as transporters with uniquely potent effects on mTORC1-mediated growth. In this study, we show the two human PATs that are widely expressed in normal tissues and cancer cell lines, namely PAT1 and PAT4, behave similarly to fly PATs when expressed in Drosophila. Small interfering RNA knockdown shows that these molecules are required for the activation of mTORC1 targets and for proliferation in human MCF-7 breast cancer and HEK-293 embryonic kidney cell lines. Furthermore, activation of mTORC1 in starved HEK-293 cells stimulated by amino acids requires PAT1 and PAT4, and is elevated in PAT1-overexpressing cells. Importantly, in HEK-293 cells, PAT1 is highly concentrated in intracellular compartments, including endosomes, wherein mTOR shuttles upon amino-acid stimulation. Therefore our data are consistent with a model in which PATs modulate the activity of mTORC1 not by transporting amino acids into the cell but by modulating the intracellular response to amino acids.

Therapeutic class-specific signal detection of bradycardia associated with propranolol hydrochloride.

BACKGROUND: Propranolol hydrochloride, one of the most widely used beta-blocker in the treatment of hypertension since 1960s, shows a number of serious and non-serious adverse events. OBJECTIVE: Major objectives of this study were to extract the Canadian Adverse Drug Reaction Monitoring Program (CADRMP) database for possible toxic signal detection (SD) of propranolol hydrochloride, evaluate the frequency of the bradycardia associated with it in different stratified groups for a putative signal, and generate awareness in healthcare professionals regarding usefulness of SD. MATERIALS AND METHODS: Appropriate statistical methods were used for adverse drug reaction (ADR) signal detection such as, proportional reporting ratio (PRR); reporting odds ratio (ROR); the Chi-square (chi(2)) statistic method; the 95% confidence interval (CI); the observed to expected ratio (O/E); and Du Mouchel method were used to calculate the possible signals. Significance of chi(2) and other calculated statistics, e.g., PRR and ROR, was based on a composite criterion of regulatory guidelines and not on any particular statistical level of significance. RESULTS: Calculated statistics by different methods were compared with the regulatory criteria of a statistic value >/=4.0 for chi(2), and >/=3.0 for the rest for SD to be declared significant. The PRR statistic was found to be 2.5054; by the ROR method it was 2.5820; the chi(2) statistic was 3.2598, whereas the lower and upper limits of 95% CI of PRR were found to be 0.0778 and 1.9104, respectively, by the O/E ratio was found to be 2.3978, and PRR with the help of Du Mouchel was found to be 2.3979. Thus, the bradycardia-propranolol signals calculated in this study were not significant. CONCLUSIONS: The therapeutic class specific signal of bradycardia associated with propranolol hydrochloride was not found potent enough to cause bradycardia. However, since the calculated statistics were very high albeit not significant, the possibility of bradycardia-propranolol pairing should still be analyzed from larger databases.

A dual-deposition setup for fabricating nanoparticle-thin film hybrid structures.

This report describes a dual-deposition setup for fabricating well-defined nanoparticles-thin film structures. The setup consists of a particle synthesis section for the gas phase generation of size-selected nanoparticles and a deposition section for the sequential growth of thin film and nanoparticle layers on substrates using vacuum evaporation and atmospheric pressure electrostatic precipitator techniques, respectively. The setup has been used to deposit Pd nanoparticles-Pr thin film structures. Average sizes and size distributions of Pd nanoparticles measured online during the particle synthesis by means of electrical mobility analysis have been compared with those of nanoparticle samples deposited on Pr thin film and other substrates and measured by high resolution scanning electron microscopy and transmission electron microscopy techniques. The setup is useful for depositing a variety of nanoparticles-thin film structures.

Elimination of the differential chemoresistance between the murine B-cell lymphoma LY-ar and LY-as cell lines after arsenic (As2O3) exposure via the overexpression of gsto1 (p28).

PURPOSE: Arsenic, in the form of As(2)O(3), has gained therapeutic importance because it has been shown to be very effective clinically in the treatment of acute promyelocytic leukemia (APL). Via numerous pathways arsenic induces cellular alterations such as induction of apoptosis, inhibition of cellular proliferation, stimulation of differentiation, and inhibition of angiogenesis. Responses vary depending on cell type, dose and the form of arsenic. GSTO1, a member of the glutathione S-transferase superfamily omega, has recently been shown to be identical to the rate-limiting enzyme, monomethyl arsenous (MMA(V)) reductase which catalyzes methylarsonate (MMA(V)) to methylarsenous acid (MMA(III)) during arsenic biotransformation. In this study, we investigated whether arsenic trioxide (As(2)O(3)) induces apoptosis in both chemosensitive and chemoresistant cell lines that varied in their expression of p28 (gsto1), the mouse homolog of GSTO1. METHODS: The cytotoxicity of arsenic in the gsto1- and bcl-2-expressing chemoresistant and radioresistant LY-ar mouse lymphoma cell line, was compared with that of the LY-ar's parental cell line, LY-as. LY-as cells are radiosensitive, apoptotically permissive, and do not express gsto1 or bcl-2. Cell survival, glutathione (GSH) levels, mitochondrial membrane potential, and stress-activated kinase status after arsenic treatment were examined in these cell lines. RESULTS: As(2)O(3) induced an equivalent dose- and time-dependent increase in apoptosis in these cell lines. Cellular survival, as measured after a 24-h exposure, was also the same in each cell line. Reduced GSH was modulated in a similar time- and dose-dependent manner. Apoptosis was preceded by loss of mitochondrial membrane potential that triggered caspase-mediated pathways associated with apoptosis. With a prolonged exposure of As(2)O(3), both cell lines showed decreased activation of ERK family members, ERK1, ERK2 and ERK5. As(2)O(3) enhanced the death signals in LY-ar cells through a decrease in GSH, loss of mitochondrial membrane potential, and abatement of survival signals. This effect is similar to that seen when LY-ar cells are treated with thiol-depleting agents or by the removal of methionine and cysteine (GSH precursor) from the growth medium. This response is also completely contrary to that seen for radiation, actinomycin D, VP-16 and other agents, where LY-ar cells do not succumb to apoptosis. CONCLUSIONS: The overexpression of gsto1 in normally chemoresistant and radioresistant LY-ar cells renders them vulnerable to the cytotoxic effects of As(2)O(3), despite the 30-fold overexpression of the survival factor bcl-2. Gsto1 and its human homolog, GSTO1, may serve as a marker for arsenic sensitivity, particularly in cells that are resistant to other chemotherapeutic agents.

Oxygen-induced pulmonary injury in gamma-glutamyl transpeptidase-deficient mice.

We used mice with a targeted disruption in g-glutamyl transpeptidase (GGT-deficient mice) to study the role of glutathione (GSH) in protection against oxygen-induced lung injury. These mice had reduced levels of lung GSH and restricted ability to synthesize GSH because of low levels of cysteine. When GGT-deficient mice were exposed to 80% oxygen, they developed diffuse pulmonary injury and died within eight days. Ten of 12 wild-type mice were alive after 18 days. Administration of N-acetylcysteine (NAC) to GGT-deficient mice corrected GSH values and prevented the development of severe pulmonary injury and death. Oxygen exposure induced an increase in lung GSH levels in both wild-type and GGT-deficient mice, but induced levels in the mutant mice were <50% of those in wild-type mice. Cysteine levels were approximately 50-fold lower than GSH levels the lungs of both wild-type and GGT-deficient mice. Levels of lung RNA coding for the heavy subunit of g-glutamyl cysteine synthetase rose three- to fourfold after oxygen exposure in both wild-type and GGT-deficient mice. In contrast, oxygen exposure failed to provoke increases in glutathione synthetase, glutathione peroxidase, glutaredoxin, or thioredoxin.