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Biomedical subjects

B Mishra

Publications and source records attributed to B Mishra.

At least 55 records · Page 3Linked to original sources
PubMed2000

Comparison of Vitek Yeast Biochemical Card with conventional methods for speciation of Candida.

The ability of the Vitek Yeast Biochemical Card to identify yeast isolates was compared with conventional methods. Of the fifty yeast isolates tested same species identification was obtained in thirty-four isolates. The Vitek yeast biochemical card identified 13 isolates which could not be identified by the conventional tests. Though the Vitek Yeast biochemical card gave a good rapid identification the high cost of each test severely limits its routine use in most of the laboratories.

Candida↗
PubMed1999

Whole-genome shotgun optical mapping of Deinococcus radiodurans.

A whole-genome restriction map of Deinococcus radiodurans, a radiation-resistant bacterium able to survive up to 15,000 grays of ionizing radiation, was constructed without using DNA libraries, the polymerase chain reaction, or electrophoresis. Very large, randomly sheared, genomic DNA fragments were used to construct maps from individual DNA molecules that were assembled into two circular overlapping maps (2.6 and 0.415 megabases), without gaps. A third smaller chromosome (176 kilobases) was identified and characterized. Aberrant nonlinear DNA structures that may define chromosome structure and organization, as well as intermediates in DNA repair, were directly visualized by optical mapping techniques after gamma irradiation.

Chromosomes, Bacterial↗
PubMed1999

Elf3 encodes a novel 200-kD beta-spectrin: role in liver development.

beta-spectrins are crucial for the maintenance of cell shape, the establishment of cell polarity, and the formation of distinct membrane domains. Our strategy for identifying genes important for hepatocyte polarity has been to utilize subtractive hybridization of early embryonic mouse cDNA liver libraries. As a result, we have cloned three isoforms of a novel beta-spectrin elf (embryonic liver beta-fodrin), and here we report the analysis of elf3, the longest isoform (8172 nt). ELF3 comprises 2154 residues with an overall similarity of 89.0% and 95.3% to mouse beta-spectrin (betaSpIIsigma1) at the nucleotide and amino acid level, respectively. ELF3 is characterized by an actin-binding domain, a long repeat domain, and a short regulatory domain remarkable for the absence of a PH domain. Linkage analysis reveals that elf3 maps to mouse chromosome 11 between D11Bir6 and D11Xrf477, a different chromosomal locus from that of the other four spectrin genes. Northern blot analysis utilizing an elf3 3'-UTR probe demonstrates an abundant 9.0-kb transcript in brain, liver, and heart tissues. Western blot with a polyclonal antibody against ELF identifies a 200 kD protein in mouse liver, brain, kidney, and heart tissues. Immunohistochemical studies demonstrate ELF labeling of the basolateral or sinusoidal membranes surface as well as a granular cytoplasmic pattern in hepatocytes. Antisense studies utilizing cultured liver explants show a vital role of elf3 in hepatocyte differentiation and intrahepatic bile duct formation. The differential expression, tissue localization, and functional studies demonstrate the importance of elf3 in modulating interactions between various components of the cytoskeleton proteins controlling liver and bile duct development.

Amino Acid Sequence↗
PubMed1999

Genomic structure, chromosomal mapping, and muscle-specific expression of a PH domain-associated intronless gene, cded/lior.

The aim of our study was to isolate novel gene(s) involved in cell differentiation and embryonic liver development. Mouse cded/lior was identified from subtraction hybridization of embryonic liver cDNA libraries as well as an adult mouse liver genomic DNA library. The full open reading frame of cded/lior encodes a 131-amino acid protein with 71.88% overall similarity to the PH domain of rat PLC-gamma1. A gapped search with the C-terminal region of CDED/LIOR revealed a 36-41% similarity to several proteins related to signal transduction and cell replication, such as ORC1 and KSR. Northern blot analysis of adult mouse tissues shows a strong 2.6-kb transcript restricted to heart and skeletal muscle. RT-PCR utilizing cded/lior-specific primers demonstrates cded/lior mRNAs in heart, brain, and liver tissue throughout mid-embryonic mouse gestation. cded/lior maps to the distal end of mouse Chromosome (Chr) 2. Analysis of the genomic structure for cded/lior demonstrated a single exon gene that is not an alternatively spliced isoform of PLC-gamma1. Analysis of the cded/lior promoter region revealed a high GC-content, high ratio of CpG/GpC, multiple GC-boxes, the lack of a TATA box, CTF/NFI element, and two MyoD-MCK binding sites. These characteristics are also found in several genes important in the regulation of cell growth or DNA synthesis, such as transforming growth factor-beta1, c-Ha-ras, nerve growth factor, epidermal growth factor receptor, and DNA polymerase beta. These results suggest that cded/lior is a mesoderm/muscle-specific transcript that may be involved in the mesodermal inductive and regulatory interactions required for liver formation and embryonic development.

Amino Acid Sequence↗
PubMed1999

Optical PCR: genomic analysis by long-range PCR and optical mapping.

Optical mapping is an approach for the rapid, automated, non-electrophoretic construction of ordered restriction maps of DNA from ensembles of single molecules. Previously, we used optical mapping to make high-resolution maps of large insert clones such as bacterial artificial chromosomes (BAC) and large genomic DNA molecules. Here, we describe a combination of optical mapping and long-range polymerase chain reaction (PCR), in a process we term optical PCR, which enables automated construction of ordered restriction maps of long-range PCR products spanning human genomic loci. Specifically, we amplified three long PCR products, each averaging 14.6 kb in length, which span the 37-kb human tissue plasminogen activator (TPA) gene. PCR products were surface mounted in gridded arrays, and samples were mapped in parallel with either ScaI, XmnI, HpaI, ClaI, or BglII. A contig of overlapping high-resolution maps was generated, which agreed closely with maps predicted from sequence data. The data demonstrate an approach to construct physical maps of genomic loci where very little prior sequence information exists, since the only sequence needed is that required to anchor PCR primers. Large segments of genomic DNA (within the practical limits imposed by long-range PCR) can be mapped quickly and to high resolution without the use of cloning vectors.

DNA Restriction Enzymes↗
PubMed1999

Optical mapping and its potential for large-scale sequencing projects.

Physical mapping has been rediscovered as an important component of large-scale sequencing projects. Restriction maps provide landmark sequences at defined intervals, and high-resolution restriction maps can be assembled from ensembles of single molecules by optical means. Such optical maps can be constructed from both large-insert clones and genomic DNA, and are used as a scaffold for accurately aligning sequence contigs generated by shotgun sequencing.

Base Sequence↗
PubMed1999

A shotgun optical map of the entire Plasmodium falciparum genome.

The unicellular parasite Plasmodium falciparum is the cause of human malaria, resulting in 1.7-2.5 million deaths each year. To develop new means to treat or prevent malaria, the Malaria Genome Consortium was formed to sequence and annotate the entire 24.6-Mb genome. The plan, already underway, is to sequence libraries created from chromosomal DNA separated by pulsed-field gel electrophoresis (PFGE). The AT-rich genome of P. falciparum presents problems in terms of reliable library construction and the relative paucity of dense physical markers or extensive genetic resources. To deal with these problems, we reasoned that a high-resolution, ordered restriction map covering the entire genome could serve as a scaffold for the alignment and verification of sequence contigs developed by members of the consortium. Thus optical mapping was advanced to use simply extracted, unfractionated genomic DNA as its principal substrate. Ordered restriction maps (BamHI and NheI) derived from single molecules were assembled into 14 deep contigs corresponding to the molecular karyotype determined by PFGE (ref. 3).

Animals↗
PubMed1999

Design, development, and biopharmaceutical properties of buccoadhesive compacts of pentazocine.

Buccoadhesive compacts (BCs) of pentazocine (PZ) were prepared by the direct compression method using polymers like carbopol 974P (CP 974P) and hydroxypropyl methylcellulose (HPMC K4M) in ratios of 1:0 (batch B1), 1:1 (B2), 1:2 (B3), 1:4 (B4), and 0:1 (B5). The compacts were evaluated for thickness uniformity, weight variation, drug content uniformity, and swelling index. Swelling was increased with an increase in HPMC K4M content in the compacts. An in vitro assembly was developed to measure and compare the bioadhesive strength of compacts. The maximum bioadhesive strength was observed in compacts formulated with a combination of CP 974P and HPMC K4M. The compacts were evaluated in vitro for 24 hr in pH 6.6 phosphate buffer using a standardized dissolution apparatus. The data were evaluated by a simple power equation (Mt/M infinity = Ktn); it was observed that all the compacts followed non-Fickian release kinetics. Some of the buccoadhesive compacts were evaluated in vivo in rabbits. The compacts gave controlled blood level profiles with a twofold to threefold increase in area-under-the-curve (AUC) values in comparison to oral administration of aqueous drug solution.

Adhesives↗
PubMed1999

Surgical outcome in patients with coexisting multiple sclerosis and spondylosis.

OBJECTIVES: Multiple sclerosis (MS) is a neuro-degenerative disease of unknown etiology which results in destruction of myelin. A variety of neurologic signs and symptoms are associated with MS and include myelopathy, extremity weakness, low back pain, sciatica and paresthesias. Many of these signs and symptoms are identical to those experienced by patients with spondylosis (e.g. spinal stenosis, disc herniations). The coexistence of MS with spondylosis can be problematic both for diagnosis and treatment. MATERIALS AND METHODS: During the period 1992 to 1996 we identified 7 patients with previously diagnosed MS who developed new syndromes which were thought to be related to a variety of degenerative spine conditions. The diagnosis of MS was based on standard clinical, immunological and neuroradiological criteria. RESULTS: Five of 7 patients demonstrated significant improvement after surgery. One patient experienced a transient MS exacerbation after surgery. CONCLUSIONS: From our series we concluded that surgery for degenerative spine conditions can be performed in a safe and effective manner in patients with coexisting multiple sclerosis.

Adult↗
PubMed1999

Optical mapping of Plasmodium falciparum chromosome 2.

Detailed restriction maps of microbial genomes are a valuable resource in genome sequencing studies but are toilsome to construct by contig construction of maps derived from cloned DNA. Analysis of genomic DNA enables large stretches of the genome to be mapped and circumvents library construction and associated cloning artifacts. We used pulsed-field gel electrophoresis purified Plasmodium falciparum chromosome 2 DNA as the starting material for optical mapping, a system for making ordered restriction maps from ensembles of individual DNA molecules. DNA molecules were bound to derivatized glass surfaces, cleaved with NheI or BamHI, and imaged by digital fluorescence microscopy. Large pieces of the chromosome containing ordered DNA restriction fragments were mapped. Maps were assembled from 50 molecules producing an average contig depth of 15 molecules and high-resolution restriction maps covering the entire chromosome. Chromosome 2 was found to be 976 kb by optical mapping with NheI, and 946 kb with BamHI, which compares closely to the published size of 947 kb from large-scale sequencing. The maps were used to further verify assemblies from the plasmid library used for sequencing. Maps generated in silico from the sequence data were compared to the optical mapping data, and good correspondence was found. Such high-resolution restriction maps may become an indispensable resource for large-scale genome sequencing projects.

Animals↗
PubMed1999

Recent trends in drug delivery systems: intranasal drug delivery.

Nasal route of drug delivery is commonly known for treatment of local ailments like-cold, cough, rhinitis etc. Recently, efforts have been made to deliver various drugs, specially peptides and proteins, through nasal route for systemic use; utilizing the principles and concepts of rate controlled drug delivery and various polymers and absorption promoters. Considering the large number of problems associated with oral, parenteral, rectal and other routes of drug administration and gradual increase in interest of pharmaceutical scientists towards exploring the possibilities of intranasal delivery of various drugs, this article aims at giving an insight into nasal cavity, consideration of factors affecting and strategies to improve drug absorption through nasal route, pharmaceutical dosage forms and delivery systems with examples of some peptides for intra nasal delivery, its advantages and limitations.

Administration, Intranasal↗
PubMed1999

Evaluation of a rapid antigen capture assay for the diagnosis of falciparum malaria.

A study was carried out to evaluate the accuracy of a dipstick antigen capture assay for the detection of Plasmodium falciparum histidine rich protein II antigen (Pf HRP-II) in peripheral blood to diagnose P. falciparum malaria. The sensitivity and specificity of the test was found to be 97 and 100 per cent respectively. The persistence of the antigen varied from 5 to 15 days after initiation of antimalarial therapy. The assay was simple to perform, rapid and easy to interpret. However, infection due to other species of human malaria parasites cannot be detected by this dipstick assay. Use of more sensitive technique like polymerase chain reaction (PCR) would help in diagnosing cases with low parasitaemia and infection due to other plasmodial species.

Adolescent↗
PubMed1999

Genomics via optical mapping. III: Contiging genomic DNA.

In this paper, we describe our algorithmic approach to constructing an alignment of (contiging) a set of restriction maps created from the images of individual genomic (uncloned) DNA molecules digested by restriction enzymes. Generally, these DNA segments are sized in the range of 1-4 Mb. The goal is to devise contiging algorithms capable of producing high-quality composite maps rapidly and in a scaleable manner. The resulting software is a key component of our physical mapping automation tools and has been used to create complete maps of various microorganisms (E. coli, P. falciparum and D. radiodurans). Experimental results match known sequence data.

Algorithms↗
PubMed1999

Quantitative buffy coat: a special adjunct for diagnosis of malaria.

Quantitative buffy coats (QBC) technique was compared with conventional blood film technique for the diagnosis of malaria in a tertiary care hospital. The QBC technique was found to be a rapid technique with a sensitivity of 83% and specificity of 94%. Malaria species identification was also possible. It was essentially very useful to detect parasites below < or = 100 parasites/ul of blood by QBC technique. However, quantification of parasitaemia could not be made using this technique. Many cases of carriers having very few gametocytes in their blood were also identified. It is therefore, concluded that the QBC technique, may be appropriate for screening populations for malaria and for detection of asymptomatic carriers to control further transmission of the disease in the community.

Adolescent↗
PubMed1999

Clinical spectrum of bacteroidaceae in a tertiary care hospital.

Members of Bacteroidaceae family are the most commonly isolated anaerobic pathogens in humans. This study summarises our experience of isolation and antimicrobial susceptibility pattern of these anaerobes from diverse clinical infections in a tertiary care hospital. Over a period of 5 years, 611 samples were received for anaerobic culture. Of these, 53 specimens yielded 62 anaerobic isolates. Thirty of the 62 isolates (48.4%) belonged to Bacteroidacea family obtained from 29 patients. They comprised of 14 (14/32; 43.7%) Prevotella spp., 13 (13/32; 40.6%) Bacteroides spp., 3 (3/32; 9.3%) Porphyromonas spp and Fusobacterium (2/32; 6.2%). In 14 of 27 patients (48%) the infection was polymicrobial. All the isolated strains were sensitive to metronidazole. This study highlights need for adopting anaerobic culture technique as a routine diagnostic procedure and constant monitoring of antimicrobial susceptibility of all anaerobic isolates.

Bacteremia↗