SERS Platform for Dengue Diagnosis from Clinical Samples Employing a Hand Held Raman Spectrometer.

Dengue is a serious global health concern especially in tropical and subtropical countries. About 2.5 billion of the world's population is at risk for dengue infection. Early diagnosis is the key to prevent the deterioration of health of the patient to severe illness. Laboratory diagnosis of dengue is essential for providing appropriate supportive treatment to dengue patients with febrile illness, which is difficult to diagnose clinically. Here, we demonstrate surface enhanced Raman scattering (SERS) based diagnosis of dengue virus in clinical blood samples collected from total of 102 subjects. All of the samples were well characterized by conventional NS1 antigen and IgM antibody ELISA kits. The silver nanorods array fabricated by glancing angle deposition technique were employed as SERS substrates. A small amount of patient blood serum (5 µL) was taken for analysis and the report was prepared within a minute. SERS spectra of pure NS1 protein as well as spiked in serum was also recorded separately. Principal component analysis (PCA) was employed as the statistical tool to differentiate dengue positive, dengue negative, and healthy subjects on the basis of their respective SERS spectra. This method provides a sensitive, rapid, and field deployable diagnosis of dengue at the early stage (within 5 days of the onset of symptoms).

Smartphone based dual mode in situ detection of viability of bacteria using Ag nanorods array.

The in-situ and rapid detection of live and dead bacteria is essential for human and environmental care. It has become one of the biggest needs in the biological and medical sciences to prevent infectious diseases, which usually occur in hospitals and field clinics. In the current scenario, antibiotic resistance is one of the severe public health problems, which requires a quick and efficient solution. Here, we report a facile sensitive, portable, user-friendly, cost-effective and time saving approach for detection of live, dead and drug-resistant bacteria. The endogenous H2S evolution was targeted to differentiate between live and dead as well as antibiotic resistant bacteria. The silver nanorods (AgNRs) arrays sensors were fabricated by glancing angle deposition technique. The colorimetric and water wettability features of as-synthesized AgNRs are found to be highly sensitive and selective for H2S. E. coli. P. aeruginosa, B. subtilis and S. aureus were used as a model organism in this study. All the bacteria were found to produce H2S by their metabolism process. In order to detect the antibiotic resistant E. coli were grown in the presence of different concentration of ampicillin in Luria broth. A drastic visible change in color as well as wetting of AgNRs array was observed. To make the technique easy, a user-friendly and field deployable mobile app 'Colorimetric Detector' was developed. This technique takes only 4-6 h whereas the conventional methods need around 24 h for the same. This dual mode facile and, inexpensive method can be easily scaled up in the field of diagnostics.

Chronic estrogen deficiency causes gastroparesis by altering neuronal nitric oxide synthase function.

BACKGROUND: Gastroparesis affects predominantly females; however, the biological basis for this gender bias is completely unknown. Several lines of evidence suggest that nitrergic dependent stomach motility function is reduced in diabetic gastroparesis and that nNOS is estrogen-regulated. AIMS: The purpose of this study was to investigate whether reduced levels of estradiol-17ß (E2) down-regulates tetrahydrobiopterin (BH4, a cofactor for nNOS dimerization and enzyme activity) biosynthesis and therefore nNOS mediated gastric motility would be impaired in a mouse model of chronic estrogen deficiency, follicle stimulating hormone receptor knock-out female mice (FORKO). METHODS: In-bred 12-week-old female FORKO mice were obtained from our FORKO breeding colony. Gastric emptying was measured in overnight fasting mice. Nitrergic relaxation (AUC/mg tissue) was measured at 2 Hz through electric field stimulation using gastric antrum strips prepared from WT and FORKO mice. Protein expression for nNOSα, BH4 biosynthesis enzymes (GCH-1, DHFR) and estrogen receptors (α, ß) were measured in gastric antrum by western blotting. Levels of BH4 and oxidized BH2, B biopterin levels were determined by HPLC. RESULTS: In FORKO, compared to wild type (WT) stomachs we indentified (1) reduced (%) gastric emptying (64 ± 2.5 vs. 77.6 ± 0.88), (2) greater reduction in nitregic relaxation (-0.13 ± 0.012 vs. -0.28 ± 0.012), (3) increased nNOS dimerization (0.48 ± 0.02 vs. 0.34 ± 0.05), (4) decreased NO release whether measured at 24 h (0.6 ± 0.04 vs. 1.7 ± 0.22, p < 0.05) or at 48 h (3.4 ± 0.26 vs. 5.0 ± 0.15, p < 0.05) of incubation, (5) decreased GCH-1 (1.9 ± 0.06 vs. 2.3 ± 0.04), DHFR (1.8 ± 0.14 vs. 2.4 ± 0.07) and ERα (2.7 ± 0.4 vs. 3.9 ± 0.4) and (6) increased oxidized biopterin levels and decreased ratio of BH4 versus BH2 + B. CONCLUSION: We conclude that chronic estrogen deficiency negatively modifies the function of both BH4 and nNOS thereby contributing to the development of gastroparesis in a FORKO mouse model.

Changes in ventilatory function following surgery for bilateral abductor paralysis.

Management of bilateral vocal fold immobility continues to remain a challenge for the Otolaryngologist who attempts to create a balance between creation of an adequate airway and preservation of voice. The flow volume loop obtained by spirometry provides an ideal objective assessment tool to evaluate the results of surgery for this condition. Our experience in using peak inspiratory flow rate (PIFR) and forced inspiratory flow with 50% of vital capacity (FIF(50)) in the lung in assessing the results of surgery is described. Seventeen patients were included in the study. The surgical procedures performed included laser posterior cordectomy with partial arytenoidectomy, endoscopic arytenoidectomy and posterior cordectomy-Kashima's technique. Twelve out of 17 patients were successfully decannulated, a success rate of 70.6%. All patients except one showed an increase in mid-inspiratory flow rates and peak inspiratory flow rates. The mean increase in FIF(50) was 0.44 l/sec (52.6%) and the mean increase in PIFR was 0.41l/sec (39.77%). No statistically significant difference in improvement of inspiratory flow rates was observed between the three surgical procedures used in the study.

Endoscopic sphenopalatine artery ligation for refractory posterior epistaxis.

Intractable posterior epistaxis remains a challenging problem for our specialty. Conventional management options in the form of anterior and posterior packing, arterial ligation of the internal maxillary or the external carotid artery and embolization, are not entirely satisfactory because of morbidity, high failure rates and occasional significant complication. Our experience with endoscopic sphenopalatine artery ligation for four patients with posterior epistaxis is described. All patients had epistaxis refractory to anterior and posterior nasal packing, which was rapidly controlled following the procedure. The technique of spheno-palatine artery ligation is described.The technique is simple and effective and prevents the morbidity and complications of nasal packing. It is especially useful in systemically compromised individuals who otherwise tolerate nasal packing poorly. and should be one of the treatment options to be considered relatively early in the management of epistaxis refractory to anterior and posterior nasal packing.

Identification and characterization of a transcriptional silencer upstream of the human BRCA2 gene.

Expression of the breast cancer susceptibility tumor-suppressor protein BRCA2, a protein potentially involved in DNA recombination repair, is tightly regulated throughout development. We have identified a transcriptional silencer at the distal end of the human BRCA2 gene promoter. This silencer is involved in the negative regulation of the expression of this gene in breast cell lines tested but not in HeLa or HepG2 cells. The 221-base-pair silencer region is characterized by a full-length Alu-repeat. Presence of specific BRCA2 silencer-binding proteins in the breast cell extracts indicates the potential regulation of BRCA2 gene expression by these proteins.

Chromosomal mapping and nucleotide sequence of a human DNA autonomously replicating sequence.

A 1.1-kb human DNA fragment (ARSH1) capable of functioning as a putative origin of replication in yeast cells has been characterized both by in situ hybridization to human metaphase chromosomes and by DNA sequencing. Our hybridization studies show a preferential localization of ARSH1 in chromosome regions 1p34-36 and 2q34-37. DNA sequence analysis indicates that in addition to the consensus sequence required for ARS function in yeast cells, nuclear matrix-associated DNA motifs are also present in the 1.1-kb fragment. These results suggest that ARSH1 sequences may serve as points of anchorage to the nuclear matrix for chromosomes 1 and 2.