Drug-resistant Mycobacterium tuberculosis among Nepalese patients at a tuberculosis referral center.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB), characterized by isoniazid and rifampicin resistance, is caused by chromosomal mutations that restrict treatment options and complicate tuberculosis management. This study sought to investigate the prevalence of pre-extensively drug-resistant (pre-XDR) and extensively drug-resistant (XDR) tuberculosis, as well as mutation pattern, in Nepalese patients with MDR/rifampicin-resistant (RR)-TB strains. METHODS: A cross-sectional study was conducted on MDR/RR-TB patients at the German Nepal Tuberculosis Project from June 2017 to June 2018. The MTBDRsl line probe assay identified pre-XDR-TB and XDR-TB. Pre-XDR-TB included MDR/RR-TB with resistance to any fluoroquinolone (FLQ), while XDR-TB included MDR/RR-TB with resistance to any FLQ and at least one additional group A drug. Mutation status was determined by comparing bands on reaction zones [gyrA and gyrB for FLQ resistance, rrs for SILD resistance, and eis for low-level kanamycin resistance, according to the GenoType MTBDRsl VER 2.0, Hain Lifescience GmbH, Nehren, Germany definition of pre-XDR and XDR] to the evaluation sheet. SPSS version 17.0 was used for data analysis. RESULTS: Out of a total of 171 patients with MDR/RR-TB, 160 had (93.57%) had MTBC, of whom 57 (35.63%) had pre-XDR-TB and 10 (6.25%) had XDR-TB. Among the pre-XDR-TB strains, 56 (98.25%) were FLQ resistant, while 1 (1.75%) was SLID resistant. The most frequent mutations were found at codons MUT3C (57.14%, 32/56) and MUT1 (23.21%, 13/56) of the gyrA gene. One patient had SLID resistant genotype at the MUT1 codon of the rrs gene (100%, 1/1). XDR-TB mutation bands were mostly detected on MUT1 (30%, 3/10) of the gyrA and rrs, MUT3C (30%, 3/10) of the gyrA, and MUT1 (30%, 3/10) of the rrs. CONCLUSIONS: Pre-XDR-TB had a significantly higher likelihood than XDR-TB, with different specific mutation bands present in gyrA and rrs genes.

Mapping the Intersubunit Interdomain FMN-Heme Interactions in Neuronal Nitric Oxide Synthase by Targeted Quantitative Cross-Linking Mass Spectrometry.

Nitric oxide synthase (NOS) in mammals is a family of multidomain proteins in which interdomain electron transfer (IET) is controlled by domain-domain interactions. Calmodulin (CaM) binds to the canonical CaM-binding site in the linker region between the FMN and heme domains of NOS and allows tethered FMN domain motions, enabling an intersubunit FMN-heme IET in the output state for NO production. Our previous cross-linking mass spectrometric (XL MS) results demonstrated site-specific protein dynamics in the CaM-responsive regions of rat neuronal NOS (nNOS) reductase construct, a monomeric protein [Jiang et al., Biochemistry, 2023, 62, 2232-2237]. In this work, we have extended our combined approach of XL MS structural mapping and AlphaFold structural prediction to examine the homodimeric nNOS oxygenase/FMN (oxyFMN) construct, an established model of the NOS output state. We employed parallel reaction monitoring (PRM) based quantitative XL MS (qXL MS) to assess the CaM-induced changes in interdomain dynamics and interactions. Intersubunit cross-links were identified by mapping the cross-links onto top AlphaFold structural models, which was complemented by comparing their relative abundances in the cross-linked dimeric and monomeric bands. Furthermore, contrasting the CaM-free and CaM-bound nNOS samples shows that CaM enables the formation of the intersubunit FMN-heme docking complex and that CaM binding induces extensive, allosteric conformational changes across the NOS regions. Moreover, the observed cross-links sites specifically respond to changes in ionic strength. This indicates that interdomain salt bridges are responsible for stabilizing and orienting the output state for efficient FMN-heme IET. Taken together, our targeted qXL MS results have revealed that CaM and ionic strength modulate specific dynamic changes in the CaM/FMN/heme complexes, particularly in the context of intersubunit interdomain FMN-heme interactions.

Probing calmodulin-NO synthase interactions via site-specific infrared spectroscopy: an introductory investigation.

Calmodulin (CaM) binds to a linker between the oxygenase and reductase domains of nitric oxide synthase (NOS) to regulate the functional conformational dynamics. Specific residues on the interdomain interface guide the domain-domain docking to facilitate the electron transfer in NOS. Notably, the docking interface between CaM and the heme-containing oxygenase domain of NOS is isoform specific, which is only beginning to be investigated. Toward advancing understanding of the distinct CaM-NOS docking interactions by infrared spectroscopy, we introduced a cyano-group as frequency-resolved vibrational probe into CaM individually and when associated with full-length and a bi-domain oxygenase/FMN construct of the inducible NOS isoform (iNOS). Site-specific, selective labeling with p-cyano-L-phenylalanine (CNF) by amber suppression of CaM bound to the iNOS has been accomplished by protein coexpression due to the instability of recombinant iNOS protein alone. We introduced CNF at residue 108, which is at the putative CaM-heme (NOS) docking interface. CNF was also introduced at residue 29, which is distant from the docking interface. FT IR data show that the 108 site is sensitive to CaM-NOS complex formation, while insensitivity to its association with the iNOS protein or peptide was observed for the 29 site. Moreover, narrowing of the IR bands at residue 108 suggests the C≡N probe experiences a more limited distribution of environments, indicating side chain restriction apparent for the complex with iNOS. This initial work sets the stage for residue-specific characterizations of structural dynamics of the docked states of NOS proteins.

Differential superoxide production in phosphorylated neuronal nitric oxide synthase mu and alpha variants.

Neuronal nitric oxide synthase (nNOS) is regulated by phosphorylation in vivo, yet the underlying biochemical mechanisms remain unclear, primarily due to difficulty in obtaining milligram quantities of phosphorylated nNOS protein; detailed spectroscopic and rapid kinetics investigations require purified protein samples at a concentration in the range of hundreds microM. Moreover, the functional diversity of the nNOS isoform is linked to its splice variants. Also of note is that determination of protein phosphorylation stoichiometry remains as a challenge. To address these issues, this study first expanded a recent genetic code expansion approach to produce phosphorylated rat nNOSµ and nNOSα holoproteins through site-specific incorporation of phosphoserine (pSer) at residues 1446 and 1412, respectively; this site is at the C-terminal tail region, a NOS-unique regulatory element. A quantitative mass spectrometric approach was then developed in-house to analyze unphosphorylated peptides in phosphatase-treated and -untreated phospho-nNOS proteins. The observed pSer-incorporation efficiency consistently exceeded 80%, showing high pSer-incorporation efficiency. Notably, EPR spin trapping results demonstrate that under l-arginine-depleted conditions, pSer1412 nNOSα presented a significant reduction in superoxide generation, whereas pSer1446 nNOSµ exhibited the opposite effect, compared to their unphosphorylated counterparts. This suggests that phosphorylation at the C-terminal tail has a regulatory effect on nNOS uncoupling that may differ between variant forms. Furthermore, the methodologies for incorporating pSer into large, complex protein and quantifying the percentage of phosphorylation in recombinant purified protein should be applicable to other protein systems.

Case Report: Survival from Clinical Rabies in a Young Child from Maharashtra, India, 2022.

A 3.5-year-old male child from Maharashtra, India, presented with features of meningoencephalitis approximately 1 month after sustaining severe bite injuries on the right hand from a stray dog. He had received four doses of post-exposure intradermal rabies vaccination (on days 0, 3, and 7 of the bite and erroneously on day 20, instead of day 28 as recommended in the updated Thai Red Cross regimen) as well as local and systemic injections of equine rabies immune globulin. The child was initially diagnosed with and treated for acute encephalitis syndrome before rabies encephalitis was confirmed by detection of rabies virus neutralizing antibodies in the cerebrospinal fluid. During the emergent period, he also received the antimalarial drug artesunate, recently reported to have antiviral effects against rabies virus. With intensive and supportive care, the child showed substantial clinical improvement over the next few weeks. He has now survived for more than 10 months after disease onset, albeit with severe neurological sequelae including diffuse cerebral and cerebellar atrophy.

Probing Protein Dynamics in Neuronal Nitric Oxide Synthase by Quantitative Cross-Linking Mass Spectrometry.

Nitric oxide synthase (NOS) is responsible for the biosynthesis of nitric oxide (NO), an important signaling molecule controlling diverse physiological processes such as neurotransmission and vasodilation. Neuronal NOS (nNOS) is a calmodulin (CaM)-controlled enzyme. In the absence of CaM, several intrinsic control elements, along with NADP+ binding, suppress electron transfer across the NOS domains. CaM binding relieves the inhibitory factors to promote the electron transport required for NO production. The regulatory dynamics of nNOS control elements are critical to governing NO signaling, yet mechanistic questions remain, because the intrinsic dynamics of NOS thwart traditional structural biology approaches. Here, we have employed cross-linking mass spectrometry (XL MS) to probe regulatory dynamics in nNOS, focusing on the CaM-responsive control elements. Quantitative XL MS revealed conformational changes differentiating the nNOS reductase (nNOSred) alone, nNOSred with NADP+, nNOS-CaM, and nNOS-CaM with NADP+. We observed distinct effects of CaM vs NADP+ on cross-linking patterns in nNOSred. CaM induces striking global changes, while the impact of NADP+ is primarily localized to the NADPH-binding subdomain. Moreover, CaM increases the abundance of intra-nNOS cross-links that are related to the formation of the inter-CaM-nNOS cross-links. Taken together, these XL MS results demonstrate that CaM and NADP+ site-specifically alter the nNOS conformational landscape.

Depression, anxiety, and stress among undergraduate health sciences students during COVID-19 pandemic in a low resource setting: a cross-sectional survey from Nepal.

Mental health is an important issue for students during the time of the COVID-19 pandemic and uncertainty. Students suffer from mental health issues due to delayed academic years and prolong stay at home during the lockdown. This study aimed to identify factors associated with depression, anxiety, and stress among undergraduate health sciences students of different medical institutions in Nepal. Materials and Methods: A web-based cross-sectional survey was conducted among 493 health sciences students between 14 July and 16 August 2020. Depression, anxiety, and stress were measured using the Depression, Anxiety, Stress Scale-21 (DASS-21). Multivariable logistic regression analysis was performed to determine the risk factors of mental health outcomes. Results: Overall, 50.5, 52.5, and 44.6% of students had symptoms of depression, anxiety, and stress, respectively. Significantly higher odds of experiencing stress symptoms [adjusted odds ratio (AOR): 2.166; 95% CI: 1.075-4.363] were found with the participants whose relatives were infected with COVID-19. Participants with age less than or equal to 21 years among undergraduate health sciences students were significantly associated with higher odds of experiencing symptoms of stress (AOR: 1.626; 95% CI: 1.110-2.383) and anxiety (AOR: 1.6251; 95% CI: 1.110-2.379) in comparison with age above 21. Staying in quarantine was significantly associated with higher odds of experiencing depressive symptoms (AOR: 2.175; 95% CI: 1.142-4.143). Participants who had internet facilities at the residence had less likely to have depressive symptoms than those who are lacking internet services (AOR: 0.420; 95% CI: 0.195-0.905). Conclusions: Staying in quarantine had higher odds of having depression and students who had internet facilities had lower odds of having depression. While staying in quarantine or isolation, it would be better to provide things to engage like the internet. A focus on improving the mental well-being of health sciences students should be initiated immediately after such a pandemic and lockdown.

Vitamin D Deficiency among Patients Visiting Outpatient Departments in a Tertiary Care Centre: A Descriptive Cross-sectional Study.

Introduction: Vitamin D deficiency is a global health issue affecting billions of people. Its deficiency results in abnormal homeostasis of calcium and phosphorous levels in an individual and results in reduced bone mineral density, which further makes them more prone to develop osteogenic disorders, such as fractures. The aim of this study is to find out the prevalence of vitamin D deficiency among patients visiting the outpatient departments in a tertiary care centre. Methods: This was a descriptive cross-sectional study done among 582 patients visiting outpatient departments in a tertiary care centre between January 1, 2019 and July 31, 2020. The study was approved by the Institutional Review Committee (Reference number: 076/077/17) of a tertiary care centre. A convenience sampling method was used. Patients' demographic detail and serum vitamin D level were determined. Data were collected retrospectively from hospital records and analysis was performed using the Statistical Package for the Social Sciences software version 17.0. Point estimate at 95% Confidence Interval was calculated along with frequency, the proportion for binary data, and mean with standard deviation for continuous data. Results: Among 582 patients enrolled in this study, 328 (56.35%) (52.32-60.38 at 95% Confidence Interval) patients were vitamin D deficient. Vitamin D deficiency was found in 238 (72.56%) females and 257 (78.35%) aged 16 to 59 years. Finally, there were 102 (31.09%) cases of vitamin D deficiency over the winter season. Conclusions: The prevalence of serum vitamin D deficiency in the current study was lower when compared to similar studies done in similar settings and similar to the prevalence from international literature. Keywords: deficient; prevalence; vitamin D.

Recycling of cathode from spent lithium iron phosphate batteries.

We demonstrate the concept of fabricating new lithium ion batteries from recycled spent 18650 lithium ion batteries (LIB). LiFePO4 cathode was extracted from these spent LIB using combined approach of pre-treatment, mechanical treatment and hydrometallurgical process wherein weak organic acids, such as methyl sulfonic acid (MSA) and p-toluene sulfonic acid (TSA), were employed for the first time for leaching at room temperature of metal ions instead of conventional strong acids. High leaching efficiencies (95%) were obtained for extraction of Li and Fe using these acids from black mass. Reuse of these extracted metal ions is also demonstrated by precipitating them and synthesizing LiFePO4 cathode. Structural characterization showed the formation of single-phase LiFePO4 and electrochemical evaluation of this cathode in a LiFePO4/Li half-cell exhibited a capacity of 93 mA h/g and 80 mA h/g at 0.2C and 1C rate respectively with good cycle stability.

Temporal Trend of Aedes albopictus in Local Urban Parks of the Republic of Korea.

Aedes albopictus (Skuse) was first reported in the Republic of Korea in 1941 (Suwon, Gyeonggi Province). Recently, a mosquito-monitoring program was established in response to the potential development of autochthonous infections of dengue, chikungunya, and Zika viruses, to identify the regional characteristics of Ae. albopictus in Suwon. Daily collections of adult mosquitoes were conducted using Blackhole UV-LED traps and BG-Sentinel traps baited with octenol, carbon dioxide or both at five sites in Suwon (Sungkyunkwan University, Manseok, Seoho, Olympic, and Jungang parks) from 1 July to 1 November 2016. Based on the ecological cycle of mosquitoes, an estimated association between the daily mean temperatures [2 wk prior to the collection date (lag 2 wk)] and relative population abundance were developed using a generalized linear model. The overall proportion of female mosquitoes collected from all traps was 88.3%. Higher female trap indices were observed for mosquitoes collected at BG-Sentinel traps. Additionally, the BG-sentinel trap was more effective collecting Ae. albopictus. Culex pipiens (Coquillett) was the most frequently collected mosquito using UV-LED traps, followed by Ae. vexans nipponii (Theobald), Ochlerotatus koreicus (Edwards), Cx. inatomi (Kamimura and Wada), and members of the Anopheles Hyrcanus Group. Within a certain temperature range, daily mean temperatures 2 wk prior to the collection period was significantly associated with a maximum abundance of Ae. albopictus (P < 0.05) at 26.2°C (95% confidence interval: 24.3-29.4°C). The BG-Sentinel trap is an effective trap for monitoring relative population abundance of Ae. albopictus, and trap catches are significantly correlated with daily mean temperatures.

The influence of climatic factors on the development of hemorrhagic fever with renal syndrome and leptospirosis during the peak season in Korea: an ecologic study.

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) and leptospirosis are seasonal rodent-borne infections in the Republic of Korea (Korea). The occurrences of HFRS and leptospirosis are influenced by climatic variability. However, few studies have examined the effects of local climatic variables on the development of these infections. The purpose of this study was to estimate the effect of climatic factors on the occurrence of HFRS and leptospirosis in Korea. METHODS: Daily records on human cases of HFRS and leptospirosis between January 2001 to December 2009 were analyzed. The associations of climatic factors with these cases in high incidence provinces were estimated using the time-series method and multivariate generalized linear Poisson models with a maximal lag of 12 weeks. RESULTS: From 2001 to 2009, a total of 2912 HFRS and 889 leptospirosis cases were reported, with overall incidences of 0.67 and 0.21 cases per 100,000, respectively, in the study areas. The increase in minimum temperature (1 °C) at a lag of 11 weeks was associated with 17.8% [95% confidence interval (CI): 15.1, 20.6%] and 22.7% (95% CI: 16.5, 29.3%) increases in HFRS and leptospirosis cases, respectively. A 1-h increase in the daily sunshine was related to a 27.5% (95% CI: 18.2, 37.6%) increase in HFRS at a lag of 0 week. A 1% increase in daily minimum relative humidity and a 1 mm increase in daily rainfall were associated with 4.0% (95% CI:1.8, 6.1) and 2.0% (95% CI: 1.2, 2.8%) increases in weekly leptospirosis cases at 11 and 6 weeks later, respectively. A 1 mJ/m2 increase in daily solar radiation was associated with a 13.7% (95% CI: 4.9, 23.2%) increase in leptospirosis cases, maximized at a 2-week lag. CONCLUSIONS: During the peak season in Korea, climatic factors play a significant role in the development of HFRS and leptospirosis. The findings of this study may be applicable to the forecasting and prediction of disease outbreaks.

Associations between Meteorological Factors and Aseptic Meningitis in Six Metropolitan Provinces of the Republic of Korea.

We assessed the association between climate factors and a number of aseptic meningitis cases in six metropolitan provinces of the Republic of Korea using a weekly number of cases from January 2002 to December 2012. Generalized linear quasi-Poisson models were applied to estimate the effects of climate factors on the weekly number of aseptic meningitis cases. We used generalized additive and generalized additive mixed models to assess dose-response relationships. A 1 °C increase in mean temperature was associated with an 11.4% (95% confidence interval (CI): 9.6%-13.3%) increase in aseptic meningitis with a 0-week lag; a 10 mm rise in rainfall was associated with an 8.0% (95% CI: 7.2%-8.8%) increase in aseptic meningitis with a 7-week lag; and a 1 mJ/m² increase of solar radiation was associated with a 5.8% (95% CI: 3.0%-8.7%) increase in aseptic meningitis with a 10-week lag. Nino3 showed positive effects in all lags, and its one unit increase was associated with an 18.9% (95% CI: 15.3%-22.6%) increase of aseptic meningitis at lag 9. The variability in the relationship between climate factors and aseptic meningitis could be used to initiate preventive measures for climate determinants of aseptic meningitis.

Single-layer graphene-assembled 3D porous carbon composites with PVA and Fe3O4 nano-fillers: an interface-mediated superior dielectric and EMI shielding performance.

In this study, a novel composite of Fe3O4 nanofiller-decorated single-layer graphene-assembled porous carbon (SLGAPC) with polyvinyl alcohol (PVA) having flexibility and a density of 0.75 g cm(-3) is explored for its dielectric and electromagnetic interference (EMI) response properties. The composite is prepared by the solution casting method and its constituents are optimized as 15 wt% SLGAPC and 20 wt% Fe3O4 through a novel solvent relaxation nuclear magnetic resonance experiment. The PVA-SLGAPC-Fe3O4 composite shows high dielectric permittivity in the range of 1 Hz-10 MHz, enhanced by a factor of 4 as compared to that of the PVA-SLGAPC composite, with a reduced loss by a factor of 2. The temperature dependent dielectric properties reveal the activation energy behaviour with reference to the glass transition temperature (80 °C) of PVA. The dielectric hysteresis with the temperature cycle reveals a remnant polarization. The enhanced dielectric properties are suggested to be the result of improvement in the localized polarization of the integrated interface system (Maxwell-Wagner-Sillars (MWS) polarization) formed by the uniform adsorption of Fe3O4 on the surface of SLGAPC conjugated with PVA. The EMI shielding property of the composite with a low thickness of 0.3 mm in the X-band (8.2-12.4 GHz) shows a very impressive shielding efficiency of ∼15 dB and a specific shielding effectiveness of 20 dB (g cm(-3))(-1), indicating the promising character of this material for flexible EMI shielding applications.

Hollow Co(0.85)Se nanowire array on carbon fiber paper for high rate pseudocapacitor.

A supercapacitor electrode is fabricated with Co0.85Se hollow nanowires (HNW) array, which is synthesized by wet chemical hydrothermal selenization of initially grown cobalt hydroxyl carbonate nanowires on conductive CFP. The dense self-organized morphology of Co0.85Se HNWs is revealed by scanning/transmission electron microscopy. The as-synthesized Co0.85Se HNWs possess high pseudocapacitive property with high capacitance retention and high durability. The areal capacitance value is seen to vary from 929.5 to 600 mF cm(-2) (60% retention) as the current density is increased from 1 to 15 mA cm(-2), an increase of a factor of 15. Based on mass loading, this corresponds to a very high gravimetric capacitance of 674 (for 2 mA cm(-2) or 1.48 Ag(-1)) and 444 Fg(1-) (for 15 mA cm(-2) or 11 A g(-1)) in a full-cell configuration with the Co0.85Se HNWs as cathode and activated carbon as anode (asymmetric configuration) promising results are obtained.

Linkage of presumptive multidrug resistant tuberculosis (MDR-TB) patients to diagnostic and treatment services in Cambodia.

SETTING: National Tuberculosis Programme, Cambodia. OBJECTIVE: In a cohort of TB patients, to ascertain the proportion of patients who fulfil the criteria for presumptive MDR-TB, assess whether they underwent investigation for MDR-TB, and the results of the culture and drug susceptibility testing (DST). METHODS: A cross sectional record review of TB patients registered for treatment between July-December 2011. RESULTS: Of 19,236 TB patients registered, 409 (2%) fulfilled the criteria of presumptive MDR-TB; of these, 187 (46%) were examined for culture. This proportion was higher among relapse, failure, return after default (RAD) and non-converters at 3 months of new smear positive TB patients (>60%) as compared to non-converters at 2 months of new TB cases (<20%). Nearly two thirds (n = 113) of the samples were culture positive; of these, three-fourth (n = 85) grew Mycobacterium tuberculosis complex (MTBc) and one-fourth (n = 28) grew non-tuberculous Mycobacteria. DST results were available for 96% of the MTBc isolates. Overall, 21 patients were diagnosed as MDR-TB (all diagnosed among retreatment TB cases and none from non-converters) and all of them were initiated on MDR-TB treatment. CONCLUSION: There is a need to strengthen mechanisms for linking patients with presumptive MDR-TB to culture centers. The policy of testing non-converters for culture and DST needs to be reviewed.

CdTe-TiO2 nanocomposite: an impeder of bacterial growth and biofilm.

The resurgence of infectious diseases and associated issues related to antibiotic resistance has raised enormous challenges which may possibly be confronted primarily by nanotechnology routes. One key need of critical significance in this context is the development of an agent capable of inhibiting quorum sensing mediated biofilm formation in pathogenic organisms. In this work we examine the possible use of a nanocomposite, CdTe-TiO2, as an impeder of growth and biofilm. In the presence of CdTe-TiO2, scanning electron microscopy (SEM) analysis shows exposed cells without the surrounding matrix. Confocal laser scanning microscopy shows spatially distributed fluorescence, a typical indication of an impeded biofilm, as opposed to the control which shows matrix-covered cells and continuous fluorescence, typical of biofilm formation. Quantitatively, the inhibition of biofilm was ∼57%. CdTe-TiO2 also exhibits good antibacterial properties against Gram positive and Gram negative organisms by virtue of the generation of reactive oxygen species inside the cells, reflected by a ruptured appearance in the SEM analysis.

Magnetite/CdTe magnetic-fluorescent composite nanosystem for magnetic separation and bio-imaging.

A new synthesis protocol is described to obtain a CdTe decorated magnetite bifunctional nanosystem via dodecylamine (DDA) as cross linker. High resolution transmission electron microscopy (HRTEM), energy-dispersive x-ray spectroscopy (EDAX), vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and fluorescence microscopy are used to characterize the constitution, size, composition and physical properties of these superparamagnetic-fluorescent nanoparticles. These CdTe decorated magnetite nanoparticles were then functionalized with anti-epidermal growth factor receptor (EGFR) antibody to specifically target cells expressing this receptor. The EGFR is a transmembrane glycoprotein and is expressed on tumor cells from different tissue origins including human leukemic cell line Molt-4 cells. The magnetite-CdTe composite nanosystem is shown to perform excellently for specific selection, magnetic separation and fluorescent detection of EGFR positive Molt-4 cells from a mixed population. Flow cytometry and confocal laser scanning microscopy results show that this composite nanosystem has great potential in antibody functionalized magnetic separation and imaging of cells using cell surface receptor antibody.

Cytological dissection and molecular characterization of chromosome 1R derived from 'Burgas 2' common wheat.

Rye chromosome 1R harbors many agronomically important genes such as resistance genes for rusts. Using the gametocidal system, we dissected the 1R chromosome substituted for wheat chromosome 1B in a common wheat cultivar 'Burgas 2'. The gametocidal system induces chromosomal breakage in the 1R chromosome, as well as in wheat chromosomes. We cytologically examined a pool of prescreened common wheat plants that had been shown to have single or multiple rearranged 1R chromosomes and established 95 common wheat lines carrying single 1R segments. We conducted PCR analysis of these lines, termed '1R dissection lines', using 10 PCR-based 1R-specific markers. We mapped the 10 PCR-based markers along the 1R chromosome with the breakpoints of the 1R dissection lines. Based on the PCR result and the positions of the primary and secondary constrictions, we could separate the breakpoints of the rearranged 1R chromosomes into 12 regions along the 1R chromosome. On the other hand, using the breakpoints, we could separate the PCR-based markers from each other except for two markers. These dissection lines are useful in mapping DNA markers and may facilitate the construction of contig maps.