Identification of promising CD8 and CD4 T cell epitopes for peptide vaccine formulation against SARS-CoV-2

The novel virus “severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)” has been responsible for the worldwide pandemic causing huge devastation and deaths since December 2019. The disease caused by this virus is known as COVID-19. The present study is based on immuno-informatics approach to develop a multi-epitope-loaded peptide vaccine to combat the COVID-19 menace. Here, we have reported the 9-mer CD8 T cell epitopes and 15-mer CD4 T cell epitopes, free from glycosylation sites, belonging to three proteins, viz. surface glycoprotein, membrane glycoprotein and envelope protein of this virus. Immunogenicity, aliphatic amino acid, antigenicity and hydrophilicity scores of the predicted epitopes were estimated. In addition, other physicochemical parameters, namely net charge, Boman index and amino acid contents, were also accounted. Out of all the epitopes, three CD8 T cell epitopes viz. PDPSKPSKR, DPSKPSKRS and QTQTNSPRR and three CD4 T cell epitopes viz. ASYQTQTNSPRRARS, RIGNYKLNTDHSSSS and RYRIGNYKLNTDHSS were found to be efficient targets for raising immunity in human against this virus. With the help of our identified potent epitopes, various pharma industries might initiate efforts to incorporate those epitopes with carrier protein or adjuvant to develop a multi-epitope-loaded peptide vaccine against SARS-CoV-2. The peptide vaccines are usually cost-effective and therefore, could be administered as a preventive measure to combat the spread of this disease. Proper clinical trials must be conducted prior to the use of identified epitopes as vaccine candidates.

Binding sites of miRNA on the overexpressed genes of oral cancer using 7mer-seed match

The microRNAs having a length of ~ 19-22 nucleotides are the small, non-coding RNAs. The evolution of microRNAs in many disorders may hold the key to tackle complex challenges. Oral cancer belongs to the group of head and neck cancer. It occurs in the mouth region that appears as an ulcer. In this study, we collected information on the overexpressed genes of oral cancer. The coding sequences of the genes were derived from NCBI and the entire set of human microRNAs present in miRBASE 21 was retrieved. The human microRNAs that can target the overexpressed genes of oral cancer were determined with the aid of our in-house software. The interaction between microRNAs and the overexpressed genes was evaluated with 7mer-m8 model of microRNA targeting. The genes DKK1 and APLN paired with only one miRNA i.e., miR-447 and miR-6087, respectively. But the genes INHBA and MMP1 were found to be targeted by 2 miRNAs, while the genes FN1, FAP, TGFPI, COL4A1, COL4A2, and LOXL2 were found to be targeted by 16, 5, 9, 18, 29, and 11 miRNAs. Subsequently, several measures such as free energy, translation efficiency, and cosine similarity metric were used to estimate the binding process. It was found that the target region's stability was higher than the upstream and downstream zones. The overexpressed genes' GC contents were calculated, revealing that the codons in target miRNA region were overall GC rich as well as GC3 rich. Lastly, gene ontology was performed to better understand each gene's involvement in biological processes, molecular function, and cellular component. Our study showed the role of microRNAs in gene repression, which could possibly aid in the prognosis and diagnosis of oral cancer.

Compositional features and pattern of codon usage for mitochondrial CO genes among reptiles

The phenomenon of non-random occurrence of synonymous nucleotide triplets (codons) in the coding sequences of genes is the codon usage bias (CUB). In this study, we used bioinformatic tool kit to analyze the compositional pattern and CUB of mitogenes namely COI, COII and COIII across different orders of reptiles. Estimation of overall base composition in the protein-coding sequences of COI, COII and COIII genes of the reptilian orders revealed an uneven usage of nucleotides. The overall count of A nucleotide was found to be the highest while the overall count of G nucleotide was the least. The CO genes across the three reptilian orders were prominently AT biased. Comparison of the GC proportion at each codon position displayed that GC1 percentage ranked the highest in all the three CO genes of the reptilian orders. SCUO values indicated weaker CUB, while considerable variation of SCUO values existed in the three CO genes across the studied reptiles. Relative synonymous codon usage (RSCU) values indicated that mostly the A ending codons were preferred. Based on the parameters namely neutrality plot, mutational responsive index and translational selection, we could conclude that natural selection was the major evolutionary force in COI, COII and COIII genes in the studied reptilian orders. However, correspondence analysis, parity plot and correlation studies indicated the existence of mutation pressure as well on the CO genes.

[Involvement of intestinal dysbiosis in the etiopathogenesis and treatment of autism spectrum disorder: a bibliographic review]

INTRODUCTION

Autism spectrum disorder is a neurodevelopmental disorder with phenotypic heterogeneity and variable symptomatic course of partly unknown etiology. The prevalence of gastrointestinal disorders in autism leads to investigate the role that intestinal microbiota may have as a causal factor and to propose specific therapeutic interventions. The role of microbiota in brain development and function, demonstrated in animal models, justifies its investigation in this neuropsychiatric disorder.

OBJECTIVE

The aim was to investigate the relationship between altered microbiota composition and autism spectrum disorder, and to assess the therapeutic role of prebiotics, probiotics and fecal transplantation in this neurodevelopmental disorder.

DEVELOPMENT

A literature review was conducted in PubMed, Cochrane Library and Google Scholar to select relevant articles related to the topic that were published between January 2012 and April 2020. Thirty-five relevant articles were selected. In 23 of them, significant differences were found in the composition and diversity of the microbiota in children with ASD, as well as in the biomolecules involved in certain metabolic pathways. The other 12 investigations reported gastrointestinal and behavioral improvements after therapeutic intervention.

CONCLUSIONS

It is reasonable to state that there is enough evidence to support the existence of a relationship between intestinal microbiota and autism spectrum disorders. This fact should be explored in depth to assess the etiopathogenic burden of dysbiosis and the possible therapeutic tools.

Dementia Symptoms among Senior Citizens Living in Geriatric Homes of Kathmandu Valley

Background With increasing age, the older population becomes more susceptible to mental disorders. It is important to recognize and develop an understanding of psychiatric morbidity particularly among the residents of geriatric homes in resource-poor settings. Objective To assess the prevalence and associated factors of dementia symptoms among Nepalese senior citizens living in geriatric homes of Kathmandu valley. Method A cross-sectional study was conducted among 304 senior citizens living in geriatric homes of Kathmandu valley. Cognitive Impairment Test (CIT), was used to assess dementia symptoms. Bivariate and multivariate logistic regressions were performed. All the variables that were significant at p < 0.05 level in the bivariate analysis were included in the multivariate regression model and statistical significance was declared at p < 0.05 with a 95.00% confidence interval (CI). Result This study showed 75.65%, of the participants, had dementia symptoms. In the multivariate logistic regression analysis, female respondents (AOR=2.94, 95% CI=1.31-6.57), respondents never received geriatric allowances (AOR=2.46, 95% CI=1.22-4.98), respondent's history of alcohol consumption habits (AOR=2.04, 95% CI=1.01-4.11) and non-vegetarian diet habits (AOR= 2.31, 95% CI=1.12-4.76) were found more likely to had higher dementia symptoms whereas, literate participants (AOR=0.19, 95% CI=0.08-0.43) were less likely to had dementia symptoms. Conclusion The high prevalence of dementia symptoms among senior citizens living in geriatric homes in the Kathmandu valley indicates an urgent need for early diagnosis and treatment of mental disorders among senior citizens to improve their quality of life and well-being.

Drug resistant Tuberculosis: A review

Tuberculosis (TB) was announced as a global emergency in 1993. There was an alarming counter attack of TB worldwide. However, when it was known that TB can be cured completely, the general public became ignorant towards the infection. The pathogenic organism Mycobacterium tuberculosis continuously evolved to resist the antagonist drugs. This has led to the outbreak of resistant strain that gave rise to "Multi Drug Resistant-Tuberculosis" and "Extensively Drug Resistant Tuberculosis" that can still be cured with a lower success rate. While the mechanism of resistance proceeds further, it ultimately causes unmanageable totally drug resistant TB (TDR-TB). Studying the molecular mechanisms underlying the resistance to drugs would help us grasp the genetics and pathophysiology of the disease. In this review, we present the molecular mechanisms behind Mycobacterium tolerance to drugs and their approach towards the development of multi-drug resistant, extremely drug resistant and totally drug resistant TB.

Synonymous codon usage and context analysis of genes associated with pancreatic cancer

Pancreatic cancer is a fatal disorder which originates in pancreas. Its mortality rate is increasing with time. Some studies also reported that pancreatic cancer would be ranked 2nd by the year 2030. Codon usage bias (CUB) arises when synonymous codons for each amino acid are not used randomly in the coding sequences of genes. We used bioinformatic methods to analyze the compositional properties, codon context and codon usage trend of the genes associated with pancreatic cancer as no work was reported yet. From the base composition analysis, the pancreatic cancer genes were found to be GC-rich and at the 3rd codon position the G/C ending codons were more preferred to A/T ending ones. The CUB was low in genes associated with pancreatic cancer. Correspondence analysis proposed that other than base constraints, CUB might also be affected by some other factors such as natural selection. Moreover, results of correlation analysis indicated that CUB and various GC contents i.e. GC, GC1, GC2, GC3 played important role in the release of free energy by transcripts of the genes associated with pancreatic cancer. The low compAI values of coding sequences suggested a low translation rate of the genes.

Chronic obstructive pulmonary disease: A crosstalk on nucleotide compositional dynamics and codon usage patterns of the genes involved in disease

Chronic obstructive pulmonary disease (COPD), a lung disease, affects a large number of people worldwide, leading to death. Here, we analyzed the compositional features and trends of codon usage of the genes influencing COPD to understand molecular biology, genetics, and evolutionary relationships of these genes as no work was reported yet. Coding sequences of COPD genes were found to be rich in guanine-cytosine (GC) content. A high value (34-60) of the effective number of codons of the genes indicated low codon usage bias (CUB). Correspondence analysis suggested that the COPD genes were distinct in their codon usage patterns. Relative synonymous codon usage values of codons differed between the more preferred codons and the less-preferred ones. Correlation analysis between overall nucleotides and those at third codon position revealed that mutation pressure might influence the CUB of the genes. The high correlation between GC12 and GC3 signified that directional mutation pressure might have operated at all the three codon positions in COPD genes.

DNA compositional dynamics and codon usage patterns of M1 and M2 matrix protein genes in influenza A virus

Influenza A virus subtype H3N2 has been a serious health issue across the globe with approximately 36 thousand annual casualties in the United States of America only. Co-circulation in avian, swine and human hosts has led to frequent mutations in the virus genome, due to which development of successful antivirals against the virus has become a formidable challenge. Recently, focussed research is being carried out targeting the matrix proteins of this strain as vaccine candidates. This study is carried out to unravel the key features of the genes encoding the matrix proteins that manoeuvre the codon usage profile in the H3N2 strains. The findings reveal differential codon choice for both matrix protein 1 and matrix protein 2. The overall codon usage bias is less pronounced in both the datasets which is evident from higher value of effective number of codons (>55). Comparison of the codon usage for both the genes under study with that of humans revealed that the viral codon usage is not fully optimized for the human host conditions. Both the genes enrolled in the study showed variation which was reflected in almost all the indices used for codon usage studies. Neutrality analysis revealed a weak role of mutation pressure while selection was the major contributor towards codon usage.

Alteration of goat sperm ecto-phosphoprotein phosphatase activity and its distribution on the sperm surface during epididymal maturation

Phosphoprotein phosphatase (ecto-PPase) of goat epididymal sperm outer surface showed a significant increase in its activity at the initial stage of epididymal sperm maturation (up to the proximal corpus region) followed by a sharp fall towards the terminal phase of the maturation event. PPase activity showed nearly the same profile when estimated in intact cells as well as in isolated sperm plasma membrane. The ecto-PPase was purified to apparent homogeneity by using various biochemical fractionation procedures, such as solubilization with Triton X-100, sephadex gel filtration chromatography, concanavalin A-sepharose affinity chromatography and diethylaminoethyl-cellulose ion-exchange chromatography. The isolated PPase has a molecular mass of approximately 36 kDa and an isoelectric point of 5.95. Sperm surface topography of the enzyme was investigated using fluorescein isothiocyanate-conjugated antibody of the purified PPase. The immunofluorescent studies have demonstrated that the isolated PPase is localized on the external surface of viable sperm. Immunocytochemical studies also revealed a marked topographical alteration of ecto-PPase during epididymal transit of the male gametes. Immunoreactivity was observed all over the surface of caput sperm, but was restricted primarily to the anterior tip of the head in the corpus sperm and to the posterior part of the head in cauda sperm cells. The maturation-dependent decrease in PPase activity was also confirmed by immunofluorescent studies. This remarkable maturation-dependent modification of ecto-PPase activity, as well as its distribution on sperm surface, suggest that the ecto enzyme may play an important role in sperm function by regulating the phosphorylation states of the membrane-associated and reproductive fluid phosphoprotein substrates.

An autosomal recessive syndrome of choanal atresia, hypothelia/athelia and thyroid gland anomalies overlapping bamforth syndrome, ANOTHER syndrome and methimazole embryopathy

Two sibs from an inbred Arab family are described with an autosomal syndrome of choanal atresia, hypothelia/athelia and thyroid gland anomalies overlapping Bamforth syndrome, ANOTHER syndrome and methimazole embryopathy. In one case the syndrome described was lethal. Cases with similar features are reviewed and genetic mutations discussed.

Acid-induced partly folded conformation resembling a molten globule state of xylanase from an alkalothermophilic Bacillus sp

Nonnative protein structures having a compact secondary, but not rigid tertiary structure, have been increasingly observed as intermediate states in protein folding. We have shown for the first time during acid-induced unfolding of xylanase (Xyl II) the presence of a partially structured intermediate form resembling a molten globule state. The conformation and stability of Xyl II at acidic pH was investigated by equilibrium unfolding methods. Using intrinsic fluorescence and CD spectroscopic studies, we have established that Xyl II at pH 1.8 (A-state) retains the helical secondary structure of the native protein at pH 7.0, while the tertiary interactions are much weaker. At variance, from the native species (N-state), Xyl II in the A-state binds 1-anilino-8-sulfonic acid (ANS) indicating a considerable exposure of aromatic side chains. Lower concentration of Gdn HCl are required to unfold the A-state. For denaturation by Gdn HCl, the midpoint of the cooperative unfolding transition measured by fluorescence for the N-state is 3.5 +/- 0.1 M, which is higher than the value (2.2 +/- 0.1 M) observed for the A-state at pH 1.8. This alternatively folded state exhibits certain characteristics of the molten globule but differs distinctly from it by its structural stability that is characteristic for native proteins.

Artificial chaperone mediated refolding of xylanase from an alkalophilic thermophilic Bacillus sp. Implications for in vitro protein renaturation via a folding intermediate

To gain insight into the molecular aspects of unfolding/refolding of enzymes from extremophilic organisms, we have used xylanase from an alkalophilic thermophilic Bacillus as the model system. Kinetics of denaturation/renaturation were monitored using intrinsic fluorescence studies. The protein fluorescence measurements suggested a putative intermediate state present in 0.08 M guanidine hydrochloride with an emission maximum of 345 nm; the far-UV circular dichroism spectra revealed content of secondary structure similar to the native enzyme. Studies with the fluorescent apolar probe 1-anilinonapthalene-8-sulfonate (1,8-ANS) were consistent with the presence of increased hydrophobic surfaces as compared with the native or fully unfolded protein. The refolding of Xyl II, was attempted by a relatively new strategy using an artificial chaperone assisted two-step method. The unfolded xylanase was found to bind to the detergent transiently and the subsequent addition of methyl-beta-cyclodextrin helped to strip the detergent and assist in the folding. Our findings suggested that the detergent stabilized a putative intermediate in the folding pathway seemingly equivalent to the folding state described as molten globule. The reactivation of Xyl II was affected by ionic as well as nonionic detergents. However, the cationic detergent cetyltrimethylammonium bromide (CTAB) provided a maximum reactivation (threefold) of the enzyme. The 'delayed detergent addition' experiments revealed that the detergent acts by suppressing the initial aggregate formation and not by dissolving aggregates. The relevance of our findings to the role of artificial chaperones in vivo is discussed.

Novel bifunctional inhibitor of xylanase and aspartic protease: implications for inhibition of fungal growth

A novel bifunctional inhibitor (ATBI) from an extremophilic Bacillus sp. exhibiting an activity against phytopathogenic fungi, including Alternaria, Aspergillus, Curvularia, Colletotricum, Fusarium, and Phomopsis species, and the saprophytic fungus Trichoderma sp. has been investigated. The 50% inhibitory concentrations of ATBI ranged from 0.30 to 5.9 microg/ml, whereas the MIC varied from 0.60 to 3.5 microg/ml for the fungal growth inhibition. The negative charge and the absence of periodic secondary structure in ATBI suggested an alternative mechanism for fungal growth inhibition. Rescue of fungal growth inhibition by the hydrolytic products of xylanase and aspartic protease indicated the involvement of these enzymes in cellular growth. The chemical modification of Asp or Glu or Lys residues of ATBI by 2,4,6-trinitrobenzenesulfonic acid and Woodward's reagent K, respectively, abolished its antifungal activity. In addition, ATBI also inhibited xylanase and aspartic protease competitively, with K(i) values 1.75 and 3.25 microM, respectively. Our discovery led us to envisage a paradigm shift in the concept of fungal growth inhibition for the role of antixylanolytic activity. Here we report for the first time a novel class of antifungal peptide, exhibiting bifunctional inhibitory activity.

The technical efficiency of hospitals under a single payer system: the case of Ontario community hospitals

Using DEA, we investigated the impact of ownership, size, and location on the relative technical efficiency of community hospitals in Ontario, which has a single payer system. Consistent with Hansmann's theory of non-profit organizations and contrary to US-based research, we find no significant differences in efficiency across ownership types (government, religious or secular non-profit). Nor do we find significant differences in efficiency by size or location. Our findings suggest that model formulation and differences in payer mix across types of hospitals in the US have a strong influence on the measurement of the hospital ownership-efficiency relationship.

Shedding of c-Met is regulated by crosstalk between a G-protein coupled receptor and the EGF receptor and is mediated by a TIMP-3 sensitive metalloproteinase

A wide repertoire of transmembrane proteins are proteolytically released from the cell surface by a process known as ‘ectodomain shedding’, under both normal and pathophysiological conditions. Little is known about the physiological mechanisms that regulate this process. As a model system, we have investigated the metalloproteinase-mediated cleavage of the hepatocyte growth factor receptor, Met. We show that epidermal growth factor (EGF) receptor activation, either directly by EGF or indirectly via the G-protein coupled receptor (GPCR) agonist lysophosphatidic acid (LPA), induces cleavage of Met through activation of the Erk MAP kinase signalling cascade. The tyrosine kinase activity of the EGFR was a prerequisite for this stimulation, since treatment of cells with a synthetic inhibitor of this receptor, AG1478, completely abrogated shedding. The metalloproteinase mediating Met cleavage was specifically inhibited by the tissue inhibitor of metalloproteinases (TIMP)-3, but not by TIMP-1 or TIMP-2. Furthermore, the level of Met shedding could be modulated by different cell-matrix interactions. Our results indicate that ectodomain shedding is a highly regulated process that can be stimulated by EGFR signalling pathways and integrin ligation.

Cutting edge: CD43 functions as a T cell counterreceptor for the macrophage adhesion receptor sialoadhesin (Siglec-1)

Sialoadhesin (Siglec-1) is a macrophage-restricted sialic acid-binding receptor that mediates interactions with hemopoietic cells, including lymphocytes. In this study, we identify sialoadhesin counterreceptors on T lymphocytes. Several major glycoproteins (85, 130, 240 kDa) were precipitated by sialoadhesin-Fc fusion proteins from a murine T cell line (TK-1). Binding of sialoadhesin to these glycoproteins was sialic acid dependent and was abolished by mutation of a critical residue (R97A) of the sialic acid binding site in the membrane distal Ig-like domain of sialoadhesin. The 130- and 240-kDa sialoadhesin-binding glycoproteins were identified as the sialomucins CD43 and P-selectin glycoprotein ligand 1 (CD162), respectively. CD43 expressed in COS cells supported increased binding to immobilized sialoadhesin. Finally, sialoadhesin bound different glycoforms of CD43 expressed in Chinese hamster ovary cells, including unbranched (core 1) and branched (core 2) O:-linked glycans, that are normally found on CD43 in resting and activated T cells, respectively. These results identify CD43 as a T cell counterreceptor for sialoadhesin and suggest that in addition to its anti-adhesive role CD43 may promote cell-cell interactions.

pH dependent conformational and structural changes of xylanase from an alkalophilic thermophilic Bacillus sp (NCIM 59)

The pH induced conformational and structural changes of Xyl II have been investigated from the alkalophilic thermophilic Bacillus sp. using kinetic, circular dichroism and fluorescence spectroscopy studies. The systematic studies on the folding and stability of cellulase-free xylanases are important, since their biotechnological applications require them to function under extremes of pH and temperature. The Trp fluorescence and the kinetic constants were found dependent on the pH. Above pH 8, the enzyme exhibited unfolding transitions as revealed by a red shift in the emission maximum as well as decreases in the fluorescence intensity. Circular dichroism studies revealed a decrease in the CD ellipticity at 222 nm at pH 9 and 10. The reduced catalytic activity of Xyl II at alkaline pH is correlated to the pH induced unfolding and ionization or protonation of key protein residues. The pH profile of Xyl II showed apparent pK values of 5.5 and 7 for the free enzyme and 5.6 and 6.7 for the enzyme-substrate complex. The abnormally high pK of 6.7 indicated the participation of a carboxyl group present in a non-polar environment. The pH dependence of inactivation kinetics of Xyl II with Woodward's reagent K corroborates evidence for the presence of a catalytically important carboxyl residue. The sequence alignment studies of Xyl II, in combination with kinetic and chemical modification data provide strong evidence for the participation of Asp94 in the catalytic function. The Xyl II produced from an alkalophilic source, was stable at pH 10 with a t(1/2) of 24 h. However, the enzyme exhibited pH optimum at near neutral values, which can be explained by the ionization and microenvironment of the active site residues.

Micromelic dwarfism--humerus, femur and tibia type

We report a baby with severe micromelic dwarfism characterized by severe shortening of the humeri, femora and tibiae with hypoplastic radii, ulnae and fibulae which are of normal shape. We suggest that this case is similar to the case reported by Baxova et al [(1993), Paediatr Radiol 23:446-449] confirming the identity of this new bone dysplasia.

Meltrin gamma(ADAM-9) mediates cellular adhesion through alpha(6)beta(1)integrin, leading to a marked induction of fibroblast cell motility

The ADAMs (A Disintegrin and Metalloprotease Domains) are a family of membrane-anchored proteins that play a role in fertilisation, myoblast fusion and ectodomain shedding of cell surface proteins. Meltrin gamma (ADAM-9) is a widely expressed member of this family and is involved in the shedding of heparin binding epidermal growth factor. Here we report that meltrin gamma can function as a cell adhesion molecule via its disintegrin domain. Using solid-phase binding assays and antibody inhibition experiments, we demonstrate that a murine meltrin gamma-Fc (Mel gamma -Fc) fusion protein binds to the integrin alpha(6)beta(1) on the surface of fibroblast cell lines, HT1080 and Wehi 164 in a specific manner. Since alpha(6)beta(1) is important for the motility of several cell types on laminin, cell migration studies using time-lapse video microscopy were performed. Cells adhering to Mel gamma-Fc displayed a rounded morphology and a marked increase (eight- to tenfold) in their motility compared to that on laminin. Furthermore, the p160 ROCK kinase inhibitor Y-27632 specifically reduced the migration of cells on meltrin gamma but had no effect on migration of cells on laminin, whilst the general tyrosine phoshorylation inhibitor, genistein, inhibited cell migration on both substrates. These results together suggest that meltrin gamma may play a role in regulating the motility of cells by binding to alpha(6)beta(1) integrin and this may be important during a variety of biological and pathological processes.

Macrophage-tumour cell interactions: identification of MUC1 on breast cancer cells as a potential counter-receptor for the macrophage-restricted receptor, sialoadhesin

In many carcinomas, infiltrating macrophages are commonly found closely associated with tumour cells but little is known concerning the nature or significance of adhesion molecules involved in these cellular interactions. Here we demonstrate in primary human breast cancers that sialoadhesin (Sn), a macrophage-restricted adhesion molecule, is frequently expressed on infiltrating cells that often make close contact with breast carcinoma cells. To determine whether Sn could act as a specific receptor for ligands on breast cancer cell lines, binding assays were performed with a recombinant form of the protein fused to the Fc portion of human immunoglobulin G1 (IgG1) (Sn-Fc). Sn-Fc was found to bind specifically and in a sialic acid-dependent manner to the breast cancer cell lines MCF-7, T47.D and BT-20 both in solid- and solution-phase binding assays. To investigate the nature of the sialoglycoproteins recognized by Sn on breast cancer cells, MCF-7 cells were labelled with [6-3H]glucosamine. Following precipitation with Sn-Fc, a major band of approximately 240000 MW was revealed, which was shown in reprecipitation and Western blotting experiments to be the epithelial mucin, MUC1.

Interaction of metargidin (ADAM-15) with alphavbeta3 and alpha5beta1 integrins on different haemopoietic cells

Metargidin (ADAM-15) is a type I transmembrane glycoprotein belonging to the ADAM (A Disintegrin and Metalloprotease Domain) family of proteins and is widely expressed in different tissues and cell types. Members of this family contain an amino-terminal metalloprotease domain followed by a disintegrin domain, a cysteine-rich region and a membrane proximal EGF-like domain. The disintegrin domain of metargidin contains an RGD tripeptide sequence, suggesting that it may potentially interact with the integrin family of proteins. Here we identify integrin ligands for metargidin on haemopoietic cells, by using a chimeric protein containing the extracellular domain of metargidin fused to the Fc portion of human IgG. Binding activity to a panel of human cell lines was analysed by solid-phase cell-adhesion assays. Metargidin bound to a monocytic cell line, U937, and a T cell line, MOLT-4, in a specific manner. Adhesion was divalent cation- and temperature- dependent and strongly enhanced by Mn2+, all features of integrin-mediated binding. Using a panel of anti-integrin antibodies we show that alphavbeta3 is a ligand for metargidin on U937 cells. In contrast, for MOLT-4 cells, the integrin alpha5beta1 contributes to cell binding. Adhesion was mediated by the disintegrin domain of metargidin as RGD-based peptides inhibited cell binding to both cell lines. The specificity of the interaction between both alphavbeta3 and alpha5beta1 and metargidin was further confirmed by solid-phase adhesion assays using purified recombinant integrins. These results together indicate that metargidin can function as a cell adhesion molecule via interactions with alphavbeta3 and alpha5beta1 integrins.

Maturation-dependent modification of the protein phosphorylation profile of isolated goat sperm plasma membrane

Highly purified plasma membranes, isolated by an aqueous two-phase polymer method from goat epididymal spermatozoa, were found to possess a kinase activity that causes phosphorylation of serine and threonine residues of several endogenous plasma membrane proteins. Cyclic AMP, cyclic GMP, Ca(2+)-calmodulin, phosphatidylserine-diolein, polyamines and heparin had no appreciable effect on this kinase. Autoradiographic analysis showed that the profile of the phosphorylation of membrane proteins by this endogenous cAMP-independent protein kinase underwent marked modulation during the transit of spermatozoa through the epididymis. In caput sperm plasma membrane, 18, 21, 43, 52, 74 and 90 kDa proteins were phosphorylated, whereas, in the corpus and cauda epididymal spermatozoa, a differential phosphorylation pattern was observed with respect to the 90, 74, 21 and 18 kDa proteins. The rate of phosphorylation of the 74 kDa protein decreased markedly during the early phase of sperm maturation (caput to distal corpus epididymides) whereas there was little change in kinase activity in sperm plasma membrane. In contrast, the rates of phosphorylation of the 18 and 21 kDa proteins increased during the terminal phase (distal corpus to distal cauda epididymides) of sperm maturity, although the kinase activity of membrane decreased significantly during this phase. The modulation of the phosphorylated states of these specific membrane proteins may play an important role in the maturation of epididymal spermatozoa.

Structural and functional role of tryptophan in xylanase from an extremophilic Bacillus: assessment of the active site

Microenvironment and conformation of the active site of xylanase from an extremophilic Bacillus was deciphered for the first time using fluorescence spectroscopy. NBS modified enzyme showed complete inactivation and the kinetic analysis implicated the presence of an essential tryptophan at the active site of xylanase. Xylan (0.5%) protected the enzyme completely from inactivation with NBS, whereas it afforded 35% protection against the loss of fluorescence, suggesting that not all the tryptophans are involved at the substrate binding site. Quenching studies revealed that acrylamide was more efficient than KI and CsCl as indicated by the higher Stern-Volmer quenching constants (Ksv). The steric factor represented by the percentage accessibility of the tryptophan residues of XylII was higher with the positively charged Cs+ (80) than with the negatively charged I- (10), suggesting that the tryptophan residues are located in a relatively electronegative environment. In the presence of 6 M Gdn HCl the fluorescence shifted to 350 nm with increased accessibility of the fluorophore to the quenchers. The proximity of the essential carboxyl groups with a high pKa value of 6.9 [Chauthaiwale and Rao (1994) Biochim. Biophys. Acta] probably contributes to the electronegative environment of the tryptophan residue. Our results on sequence analysis of the gene encoding for XylII (Accession Number U83602 in the GenBank database) have shown that Trp 61 is highly conserved and may play a role in the structure-function relationship of the enzyme.

The potential role of sialoadhesin as a macrophage recognition molecule in health and disease

Sialoadhesin is a macrophage-restricted transmembrane glycoprotein of 185 kDa that mediates cell-cell interactions through recognition of Neu5Ac alpha2,3Gal in glycoconjugates. The extracellular region of sialoadhesin is composed of seventeen immunoglobulin-like domains, of which the amino-terminal two are highly-related structurally and functionally to the amino-terminal domains of CD22, myelin associated glycoprotein and CD33. These proteins, collectively known as the sialoadhesin family, are able to mediate sialic acid-dependent binding with distinct specificities for both the type of sialic acid and its linkage to subterminal sugars. In this review we discuss our recent studies on sialoadhesin and suggest how this molecule may contribute to a range of macrophage functions, both under normal conditions as well as during inflammatory reactions.

The amino-terminal immunoglobulin-like domain of sialoadhesin contains the sialic acid binding site. Comparison with CD22

Sialoadhesin and CD22 are members of a recently characterized family of sialic acid-dependent adhesion molecules belonging to the immunoglobulin superfamily. Sialoadhesin is a macrophage-restricted receptor containing 17 extracellular Ig-like domains which recognizes oligosaccharides terminating in NeuAc alpha 2-3Gal in N- and O-linked glycans. CD22 is a B cell-restricted receptor with seven Ig-like domains which selectively recognizes oligosaccharides terminating in NeuAc alpha 2-6Gal in N-glycans. Sequence similarity between these proteins is highest within their first four amino-terminal Ig-like domains. Here we identify the domain(s) containing the binding sites of both molecules by generating a series of extracellular domain deletion mutants fused to the Fc portion of human IgG1. Binding activity was analyzed by solid phase cell adhesion assays and also by surface plasmon resonance using purified glycophorin and CD45 as ligands for sialoadhesin and CD22, respectively. For sialoadhesin, the amino-terminal V-set Ig-like domain was both necessary and sufficient to mediate sialic acid-dependent adhesion of the correct specificity. In contrast, for murine CD22, only constructs containing both the V-set domain and the adjacent C2-set domain were able to mediate sialic acid-dependent binding. These results are consistent with the sialic acid binding site for both proteins residing in the membrane distal V-set domain, but for CD22 a direct contribution in binding from the neighboring C2-set domain cannot be excluded.

Purification and characterization of a protein kinase from goat sperm plasma membrane

A protein kinase that causes phosphorylation of serine and threonine residues of casein has been partially purified from goat cauda-epididymal sperm plasma membrane and characterized. The kinase, solubilized from the membrane with 1.0% Triton X-100, was purified to 480-fold by using DEAE-cellulose and casein-Sepharose affinity chromatographic techniques. The kinase is a strongly basic protein with pI of 9.5. The enzyme has a molecular mass of 310 kilodaltons as estimated by Sephacryl S-300 gel exclusion. The kinase showed affinity for protein substrates in the order membrane proteins > casein > phosvitin > histone > protamine. The apparent Km values of the kinase for casein and membrane proteins were 1 and 0.15 mg/mL, respectively. The synthetic peptides Kemptide and poly(Glu80Tyr20) did not serve as substrates of the enzyme. ATP, rather than GTP or PP(i), is the donor of phosphate for the phosphorylation reaction. Cyclic AMP and GMP, NaCl (0.25 M), KCl (0.25 M), Ca2+, calmodulin, phosphatidylserine, and muscle protein kinase inhibitor had no appreciable effect on the kinase activity. Heparin (0.5 microgram/mL) showed high affinity for inhibiting only 40% of the kinase activity, whereas polyamines at a relatively high concentration (5 mM) inhibited 40-50% of the enzymic activity. The kinase appears to be distinct from other protein kinases including casein kinases. The activity of the kinase derived from the purified sperm plasma membrane was markedly (approximately 90%) lost when the intact spermatozoa were pretreated with diazonium salt of sulfanilic acid, a membrane nonpenetrating surface probe.(ABSTRACT TRUNCATED AT 250 WORDS)

X-ray kinematography as a tool for investigations of distal limb movements of the cat

X-ray kinematography was used to investigate the kinematics of cat distal forelimb joints during motor behaviour. These joints are not accessible for instrumentation with external markers normally used in conventional motion analysis systems. To trace the movements in space two X-ray systems positioned rectangularly to each other illuminated the forelimb quasi-simultaneously with pulsed X-ray shots (time resolution: 20 ms). A mathematical model was developed for 3-dimensional reconstruction of the object and includes procedures for correction of image distortions, e.g., pincushion distortions and rotation of the image due to interaction of the earth's magnetic field with the electron optics of the image amplifiers. Accuracy of image correction and object reconstruction is +/- 1 pixel, corresponding to +/- 0.5 mm in space which is sufficient for investigation of the kinematics of cat distal forelimb joints. The approach described is of general relevance and useful in kinematic investigations where the structures under study are not directly accessible to external instrumentation with markers.

The impact of marketing on hospital performance

This study examines the effect of traditional and innovative marketing factors on the overall financial, operations and market performance of 71 not-for-profit hospitals in a metropolitan area. Traditional marketing factors of location, services offered and pricing did influence the financial performance of system-affiliated and non-system hospitals. They also influenced the operating performance of urban hospitals and the market performance of non-teaching institutions. In contrast, the innovative marketing factors of physician relations, community relations and specialized sales forces had no significant influence on performance differences among the hospitals in the entire sample and sub-samples based on geography, teaching involvement and system affiliation.

Attenuation of myocardial reperfusion injury by reducing intracellular calcium overloading with dihydropyridines

The effects of three different dihydropyridine (DHP) calcium channel antagonists, nisoldipine, nimodipine, and nifedipine, on myocardial ischemic and reperfusion injury were studied using isolated rat hearts subjected to ischemia and reperfusion. Hearts were perfused with Krebs-Henseleit bicarbonate buffer containing 0, 4, 16, 64 and 100 nM concentrations of the above dihydropyridines for 15 min. Global ischemia was then induced by terminating the aortic flow for 30 min at 37 degrees, followed by 30 min of reperfusion. Left ventricular (LV) functional (LV developed pressure, its first derivative and coronary flow) and biochemical parameters (creatine kinase release) were monitored prior to ischemia and during reperfusion. In separate group of hearts, intracellular free Ca2+ ([Ca2+]i) was monitored with an intracellular calcium analyzer using a fluorescent Ca2+ indicator (Fura-2 AM). Tissue Ca2+ was also measured by atomic absorption spectroscopy after perfusing the hearts with ion-free cold buffer to wash out extracellular Ca2+. Significant recovery of the coronary flow was observed in all hearts treated with a high concentration (100 nM) of DHPs compared with the control group (P < 0.05), while a lower dose of nisoldipine (16 nM) and nifedipine (64 nM) also improved the coronary flow effectively. Reduction of myocardial creatine kinase release and improvement of the recovery of LV developed pressure, dp/dtmax, were achieved by DHPs in a concentration-dependent manner. A higher concentration of DHPs also decreased the formation of myocardial thiobarbituric acid reactive substances, although these compounds did not possess direct free radical scavenging effects in vitro. Tissue Ca2+ content was reduced significantly in treated groups. The rise of [Ca2+]i during ischemia and reperfusion appeared to be attenuated by these DHPs. The concentration-response study of the three DHPs showed the effective concentrations for reducing [Ca2+]i to be 16, 64 and 100 nM nisoldipine, nifedipine and nimodipine, respectively, in this experimental setting. The above results indicate that pretreatment with DHPs can attenuate the myocardial reperfusion injury by modulating Ca2+ overloading and decreasing the susceptibility of the membrane to free radical attack.

Health care clusters in hospitals: the market audit and frameworks for planning

Many hospitals are turning to cluster relationships to gain the benefits of diversification without the troubles of increased capital costs and management conflicts. The goal of healthcare clusters is to provide a continuum of care to a defined geographic region through integration of referral and payment systems. To aid in successful planning for healthcare clusters, a market audit and frameworks for examining the current healthcare market are presented.

Teratological evaluation of an injectable male antifertility agent, styrene maleic anhydride, in rats

Polymer styrene Maleic anhydride (SMA) dissolved in dimethylsulphoxide (DMSO) was injected into the lumen in each vas deferens of male rats at dose levels of 0.25 mg, 0.50 mg, 1.0 mg, 2.5 mg, and 5.0 mg, while control rats (groups 1) received 0.03 mL DMSO in each vas deferens. After 4 weeks, the lumen was flushed with 0.1 mL DMSO and the animals were left for another 6 weeks to regain fertility. These rats were mated with virgin and coeval females. No anomaly was observed which could be related to teratogenic action of the polymer in pregnant mothers or fetuses.

Macrophages in tissues and in vitro

Macrophages have specialized functions in different tissue microenvironments such as lymphohaemopoietic organs and the nervous system. Recently, progress has been made in defining cellular and molecular properties of isolated and tissue macrophages in the developing and adult animal.

Abortifacient activity of a medicinal plant "moringa oleifera" in rats

Dried powder of leaf extract of common Indian plant Moringa Oleifera of Moringaceae family was tested experimentally in albino rats in our laboratory for its antifertility activity. Cant per cent abortifacient activity was found when administered orally in aqueous solution at dose of 175 mg/kg body weight daily to Charles foster strain albino rats from days 5-10 post mated.