Case 4. Diagnosis: Tufted angioma (angioblastoma).
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Female↗
Biomedical subjects
A Mukherjee
Publications and source records attributed to A Mukherjee.
Management of colonic perforation during percutaneous nephrolithotomy in horseshoe kidney.
Few cases of colonic injury during percutaneous nephrolithotomy (PCNL) have been reported in orthotopic kidneys and none in horseshoe kidney, and the management protocol has not been standardized. A plain film on postoperative day 1 following PCNL showed contrast medium in the descending colon, leading to the diagnosis of colonic injury in a 53-year-old male patient with horseshoe kidney and multiple bilateral stones. He was asymptomatic and was treated successfully by minimally invasive techniques. An asymptomatic patient with a colonic injury following PCNL can be treated by minimal manipulations. Computed tomography imaging is necessary prior to percutaneous surgery on a horseshoe kidney.
Colon↗
Assembly of an FtsZ mutant deficient in GTPase activity has implications for FtsZ assembly and the role of the Z ring in cell division.
FtsZ, the ancestral homologue of eukaryotic tubulins, assembles into the Z ring, which is required for cytokinesis in prokaryotic cells. Both FtsZ and tubulin have a GTPase activity associated with polymerization. Interestingly, the ftsZ2 mutant is viable, although the FtsZ2 mutant protein has dramatically reduced GTPase activity due to a glycine-for-aspartic acid substitution within the synergy loop. In this study, we have examined the properties of FtsZ2 and found that the reduced GTPase activity is not enhanced by DEAE-dextran-induced assembly, indicating it has a defective catalytic site. In the absence of DEAE-dextran, FtsZ2 fails to assemble unless supplemented with wild-type FtsZ. FtsZ has to be at or above the critical concentration for copolymerization to occur, indicating that FtsZ is nucleating the copolymers. The copolymers formed are relatively stable and appear to be stabilized by a GTP-cap. These results indicate that FtsZ2 cannot nucleate assembly in vitro, although it must in vivo. Furthermore, the stability of FtsZ-FtsZ2 copolymers argues that FtsZ2 polymers would be stable, suggesting that stable FtsZ polymers are able to support cell division.
Bacterial Proteins↗
Molecular characterization of global regulatory RNA species that control pathogenicity factors in Erwinia amylovora and Erwinia herbicola pv. gypsophilae.
rsmB(Ecc) specifies a nontranslatable RNA regulator that controls exoprotein production and pathogenicity in soft rot-causing Erwinia carotovora subsp. carotovora. This effect of rsmB(Ecc) RNA is mediated mostly by neutralizing the function of RsmA(Ecc), an RNA-binding protein of E. carotovora subsp. carotovora, which acts as a global negative regulator. To determine the occurrence of functional homologs of rsmB(Ecc) in non-soft-rot-causing Erwinia species, we cloned the rsmB genes of E. amylovora (rsmB(Ea)) and E. herbicola pv. gypsophilae (rsmB(Ehg)). We show that rsmB(Ea) in E. amylovora positively regulates extracellular polysaccharide (EPS) production, motility, and pathogenicity. In E. herbicola pv. gypsophilae, rsmB(Ehg) elevates the levels of transcripts of a cytokinin (etz) gene and stimulates the production of EPS and yellow pigment as well as motility. RsmA(Ea) and RsmA(Ehg) have more than 93% identity to RsmA(Ecc) and, like the latter, function as negative regulators by affecting the transcript stability of the target gene. The rsmB genes reverse the negative effects of RsmA(Ea), RsmA(Ehg), and RsmA(Ecc), but the extent of reversal is highest with homologous combinations of rsm genes. These observations and findings that rsmB(Ea) and rsmB(Ehg) RNA bind RsmA(Ecc) indicate that the rsmB effect is channeled via RsmA. Additional support for this conclusion comes from the observation that the rsmB genes are much more effective as positive regulators in a RsmA(+) strain of E. carotovora subsp. carotovora than in its RsmA(-) derivative. E. herbicola pv. gypsophilae produces a 290-base rsmB transcript that is not subject to processing. By contrast, E. amylovora produces 430- and 300-base rsmB transcripts, the latter presumably derived by processing of the primary transcript as previously noted with the transcripts of rsmB(Ecc). Southern blot hybridizations revealed the presence of rsmB homologs in E. carotovora, E. chrysanthemi, E. amylovora, E. herbicola, E. stewartii and E. rhapontici, as well as in other enterobacteria such as Escherichia coli, Salmonella enterica serovar Typhimurium, Serratia marcescens, Shigella flexneri, Enterobacter aerogenes, Klebsiella pneumoniae, Yersinia enterocolitica, and Y. pseudotuberculosis. A comparison of rsmB sequences from several of these enterobacterial species revealed a highly conserved 34-mer region which is predicted to play a role in positive regulation by rsmB RNA.
Amino Acid Sequence↗
Time-variant increase in methylprednisolone clearance in patients with acute respiratory distress syndrome: a population pharmacokinetic study.
Methylprednisolone (MP) disposition was evaluated in 20 individuals who participated in an ongoing randomized, double-blind, placebo-controlled study designed to evaluate the efficacy of MP in the treatment of acute respiratory distress syndrome (ARDS). MP (1 mg/kg) was given as a loading infusion over 30 minutes followed by a 1 mg/kg/day continuous i.v. infusion. Patients were switched to oral MP upon restoration of oral intake. MP plasma concentrations (n = 110) were determined using a specific HPLC method. Population pharmacokinetic analysis was performed using nonlinear mixed-effects models, implemented in NONMEM, version V. MP plasma concentration data were described by a one-compartment open model with a time-dependent, non-linear increase in the clearance (CL) of MP during the course of therapy. Initial clearance of MP (CLo) in ARDS patients at the start of therapy increased to a maximal value (CLmax) after approximately 7 days. The estimate of CLmax was similar to the CL of MP in healthy individuals reported previously. Population mean estimates (+/- SE) of parameters in the model were as follows: CLo = 13.2 +/- 2.4 L/h, CLmax = 25.0 +/- 3.6 L/h, time of half-maximal increase in CL (T50) = 41.1 +/- 8.2 h, gamma (Hill coefficient) = 3.8 +/- 0.6, and volume of distribution (Vd) = 137 +/- 30.2 L. Disease progression indices and patient demographics were evaluated as covariates, and no significant correlation was found. Means (+/- SD) of plasma protein binding differed between healthy individuals (72% +/- 4%) and ARDS patients (46% +/- 11%) (p < 0.001). The pharmacokinetics of MP in ARDS patients has not been described previously.
Administration, Oral↗
Developmental regulation of mitogen-activated protein kinase-activated kinases-2 and -3 (MAPKAPK-2/-3) in vivo during corpus luteum formation in the rat.
The current study investigates the activation in vivo and regulation of the expression of components of the p38 mitogen-activated protein kinase (MAPK) pathway during gonadotropin-induced formation and development of the rat corpus luteum, employing a sequential PMSG/human CG (hCG) treatment paradigm. We postulated that the p38 MAPK pathway could serve to promote phosphorylation of key substrates during luteal maturation, since maturing luteal cells, thought to be cAMP-nonresponsive, nevertheless maintain critical phosphoproteins. Both p38 MAPK and its upstream activator MAPK kinase-6 (MKK6) were found to be chronically activated during the luteal maturation phase, with activation detected by 24 h post hCG and maintained through 4 days post hCG. The p38 MAPK downstream protein kinase target termed MAPK-activated protein kinase-3 (MAPKAPK-3) was newly induced at both mRNA and protein levels during luteal formation and maturation, while mRNA and protein expression of the closely related MAPKAPK-2 diminished. Two potential substrates for MAPKAPKs, the small heat shock protein HSP-27 and the cAMP regulatory element binding protein CREB, were monitored in vivo for phosphorylation. HSP-27 phosphorylation was not modulated during luteal maturation. In contrast, we observed sustained luteal-phase CREB phosphorylation in vivo, consistent with upstream MKK6/p38 MAPK activation and MAPKAPK-3 induction. MAPKAPK-3-specific immune complex kinase assays provided direct evidence that MAPKAPK-3 was in an activated state during luteal maturation in vivo. Cellular inhibitor studies indicated that an intact p38 MAPK path was required for CREB phosphorylation in a cellular model of luteinization, as treatment of luteinized granulosa cells with the p38 MAPK inhibitor SB 203580 strongly inhibited CREB phosphorylation. Transient transfection studies provided direct evidence that MAPKAPK-3 was capable of signaling to activate CREB transcriptional activity, as assessed by means of GAL4-CREB fusion protein construct coexpressed with GAL4-luciferase reporter construct. Introduction of wild-type, but not kinase-dead mutant, MAPKAPK-3 cDNA, into a mouse ovarian cell line stimulated GAL4-CREB- dependent transcriptional activity approximately 3-fold. Thus MAPKAPK-3 is indeed uniquely poised to support luteal maturation through the phosphorylation and activation of the nuclear transcription factor CREB.
Animals↗
Escherichia coli heat stable enterotoxin receptors & guanylyl cyclase activity in the intestinal brush border membrane of hamsters & guinea pigs.
BACKGROUND & OBJECTIVES: Although Escherichia coli heat stable enterotoxin (STa) causes diarrhoea in laboratory animals, no studies were done to find out the species specific variation of distribution of the STa receptors in laboratory animals. The present investigation evaluates the density of STa receptors and the guanylyl cyclase (GC) activity in the small intestinal epithelial cells of hamsters and guinea pigs. METHODS: Brush border membrane (BBM) was prepared from the small intestines of hamsters and guinea pigs. Receptor binding assay, GC assay and autoradiography were performed to determine the density of STa receptors, the GC activity and molecular weights of the STa binding proteins respectively. RESULTS: The receptor densities, per mg BBM protein at equilibrium, were found to be 4.1 x 10(9) and 1.5 x 10(12) in hamsters and guinea pigs respectively. The GC activity was found to be lower in STa treated hamster BBM compared to that of guinea pig. Scatchard analysis of the stoichiometric data showed a linear plot, and STa bound with association constants of 0.31 x 10(12) M-1 and 1.04 x 10(12) M-1 in hamsters and guinea pigs respectively. Autoradiographic analysis of the SDS-PAGE, revealed that 125I-STa bound apparently to a 45 kDa membrane protein in hamster and a 115 kDa membrane protein in guinea pig. INTERPRETATION & CONCLUSIONS: It appears that a lower density of STa receptor exists in hamsters compared to that in guinea pigs. STa binds with a single population of STa receptors in each species with different ligand binding affinities. Also, the molecular weights of the STa binding proteins differ in these species. Moreover, the GC activity was found to be lower in hamsters than in guinea pigs.
Animals↗
Morphohistobiochemical characteristics of embryogenic and nonembryogenic callus cultures of sweet potato (Ipomoea batatas L.).
Ipomoea batatas callus culture raised in a medium supplemented with 2,4-D (2,4-dichlorophenoxy acetic acid) alone or 2,4-D in combination with benzyl adenine, were found to be embryogenic. Supplementation of exogenous chemicals, such as 5 g/l NaCI or 0.7 g/l proline together with a mild dose of 0.2 mg/l 2,4-D, enhanced somatic embryogenesis significantly in all the genotypes tested. Morphological, growth, physiological, histological, and biochemical characteristics of the embryogenic callus were different from the nonembryogenic callus. The former was compact, slow growing, and nodular compared with the fast growing, fragile, nonembryogenic callus. The embryogenic callus tissue had more dry matter, protein and reducing sugar contents compared with the less embryogenic callus. The somatic embryogenic response remained steady in the cultures for up to 96 weeks.
2,4-Dichlorophenoxyacetic Acid↗
Clastogenic effects of dietary supplement--Spirulina alga, and some medicinal plant products from Boswellia serrata, Withania somnifera on mice.
Pretreatment of aqueous extracts of Zyrulina (Spirulina), Aswagandha (Withania) and Nopane (Boswellia) on colchicine induced chromosome damage showed weakness of clastogenic activity in Swiss albino mice. None of the treatments increased significantly the number of chromosome aberrations.
Animals↗
Insulysin hydrolyzes amyloid beta peptides to products that are neither neurotoxic nor deposit on amyloid plaques.
Insulysin (EC. 3.4.22.11) has been implicated in the clearance of beta amyloid peptides through hydrolytic cleavage. To further study the action of insulysin on Abeta peptides recombinant rat insulysin was used. Cleavage of both Abeta(1-40) and Abeta(1-42) by the recombinant enzyme was shown to initially occur at the His(13)-His(14), His(14)-Gln(15), and Phe(19)-Phe(20) bonds. This was followed by a slower cleavage at the Lys(28)-Gly(29), Val(18)-Phe(19), and Phe(20)-Ala(21) positions. None of the products appeared to be further metabolized by insulysin. Using a rat cortical cell system, the action of insulysin on Abeta(1-40) and Abeta(1-42) was shown to eliminate the neurotoxic effects of these peptides. Insulysin was further shown to prevent the deposition of Abeta(1-40) onto a synthetic amyloid. Taken together these results suggest that the use of insulysin to hydrolyze Abeta peptides represents an alternative gene therapeutic approach to the treatment of Alzheimer's disease.
Amyloid beta-Peptides↗
Synthesis of a bacteriophage MB78 late protein by novel ribosomal frameshifting.
MB78 is a virulent phage of Salmonella typhimurium that possesses a number of interesting features, making it a suitable organism to study the regulation of gene expression. A detailed physical map of this phage genome has been constructed and is being extensively studied at the molecular level. Here, we demonstrate the expression of two late proteins of bacteriophage MB78 derived from the same gene as a result of possible ribosomal frameshifting. In vitro transcription-translation yields a major protein that migrates as 28kDa, whereas in vivo expression using pET expression vectors yields two equally expressed proteins of molecular sizes 28 and 26kDa. A putative slippery sequence TTTAAAG and a pseudoknot structure, two essential cis elements required for the classical ribosomal frameshifting, are identified in the reading frame. Mutations created at the slippery sequence resulted in a single 28kDa protein and completely abolished the expression of 26kDa protein. Thus, we have produced the first evidence that ribosomal frameshifting occurs in bacteriophage MB78 of Salmonella typhimurium.
Base Sequence↗
Functional interactions between Drosophila bHLH/PAS, Sox, and POU transcription factors regulate CNS midline expression of the slit gene.
During Drosophila embryogenesis the CNS midline cells have organizing activities that are required for proper elaboration of the axon scaffold and differentiation of neighboring neuroectodermal and mesodermal cells. CNS midline development is dependent on Single-minded (Sim), a basic-helix-loop-helix (bHLH)-PAS transcription factor. We show here that Fish-hook (Fish), a Sox HMG domain protein, and Drifter (Dfr), a POU domain protein, act in concert with Single-minded to control midline gene expression. single-minded, fish-hook, and drifter are all expressed in developing midline cells, and both loss- and gain-of-function assays revealed genetic interactions between these genes. The corresponding proteins bind to DNA sites present in a 1 kb midline enhancer from the slit gene and regulate the activity of this enhancer in cultured Drosophila Schneider line 2 cells. Fish-hook directly associates with the PAS domain of Single-minded and the POU domain of Drifter; the three proteins can together form a ternary complex in yeast. In addition, Fish can form homodimers and also associates with other bHLH-PAS and POU proteins. These results indicate that midline gene regulation involves the coordinate functions of three distinct types of transcription factors. Functional interactions between members of these protein families may be important for numerous developmental and physiological processes.
Animals↗
Synthesis and enzymatic evaluation of modified acceptors of recombinant blood group A and B glycosyltransferases.
The disaccharide alpha-L-Fucp-(1 --> 2)-beta-D-Galp-(1 --> O)-Octyl (1) is an acceptor for the human blood group A and B glycosyltransferases. Seven analogues of 1, containing deoxy, methoxy and arabino modifications of the Fuc residue, were chemically synthesized and kinetically evaluated in radioactive enzymatic assays. Both the enzymes tolerate modification of the 3'-OH on the fucose residue. The 2'-OH was found to be key to the recognition of the acceptors by these enzymes. The arabino derivative was recognized as an acceptor by the A transferase (Km of 200 microM), but not the B transferase and is the first synthetic acceptor capable of distinguishing between the two enzyme activities.
Carbohydrate Sequence↗
Synthesis of the tetrasaccharide related to the repeating unit of the antigen from Shigella dysenteriae type 5.
Starting from L-rhamnose, D-mannose and 2-amino-2-deoxy-D-glucose hydrochloride, two disaccharide blocks, namely, ethyl 2,4-di-O-benzyl-3-O-[(R)-1-(methoxycarbonyl)ethyl]-alpha-L-rhamnopyranos yl-(1-->3)-2-O-acetyl-4,6-di-O-benzyl-1-thio-alpha-D-mannopyranoside and 2-(trimethylsilyl)ethyl 2-O-acetyl-3,6-di-O-benzyl-alpha-D-mannopyranosyl-(1-->3)-4,6-di-O-benzy l-2-deoxy-2-phthalimido-beta-D-glucopyranoside, were synthesised and then allowed to react in the presence of N-iodosuccinimide and trifluoromethane sulfonic acid to give a tetrasaccharide derivative. This compound was converted into 2-(trimethylsilyl)ethyl 2,4-di-O-benzyl-3-O-[(R)-1-(methoxycarbonyl)ethyl]-alpha-L-rhamno- pyranosyl-(1-->3)-2-O-acetyl-4,6-di-O-benzyl-alpha-D-mannopyranosyl-(1-- >4)-2-O-acetyl-3,6-di-O-benzyl-alpha-D-mannopyranosyl-(1-->3)-2-acetamid o-4,6-di-O-benzyl-2-deoxy-beta-D-glucopyranoside, which on hydrogenolysis, afforded the methyl ester 2-(trimethylsilyl)ethyl glycoside of the tetrasaccharide related to the repeating unit of the O-antigen from Shigella dysenteriae type 5.
Antigens, Bacterial↗
Chiral nonsteroidal affinity ligands for the androgen receptor. 1. Bicalutamide analogues bearing electrophilic groups in the B aromatic ring.
A series of chiral analogues of bicalutamide bearing electrophilic groups (isothiocyanate, N-chloroacetyl, and N-bromoacetyl) on aromatic ring B of the parent molecule were synthesized. These compounds were designed as affinity ligands for the androgen receptor (AR). We prepared the (R)- and (S)-optical isomers of these compounds as pure enantiomers. The AR binding affinities of these compounds were measured in a competitive binding assay with the radiolabeled high-affinity AR ligand, [(3)H]mibolerone. In accordance with our previous results for the enantiomers of bicalutamide, we found that all (R)-isomers demonstrated much higher binding affinity to the AR as compared to their corresponding (S)-isomers. The para-substituted affinity ligands in ring B bound the AR with higher affinities than the corresponding meta-substituted analogues. Oxidation of thioester affinity ligands to their sulfonyl analogues for the para-substituted compounds decreased AR binding affinities and similar modification increased binding affinities for corresponding meta-analogues. The least potent para-substituted sulfonyl compounds had higher AR binding affinities than the most potent meta-substituted sulfonyl compounds. Overall, the para-substituted unoxidized molecules demonstrated the highest AR binding affinity. Subsequent research using AR exchange assays and Scatchard analyses showed that the isothiocyanate affinity ligands (R)-7, (R)-9, and (R)-10 reported herein are the first specific chemoaffinity ligands for the AR.
Androgen Antagonists↗
The Drosophila sox gene, fish-hook, is required for postembryonic development.
In Drosophila, the fish-hook (fish) gene encodes a Sox protein essential for embryonic segmentation and nervous system organization. In this study we examined potential functional roles of fish in postembryonic developmental processes, including those involved in adult appendage development. We show here that Fish protein is expressed in discrete patterns in the larval eye-antennal and leg imaginal discs, the central nervous system, the hindgut, and salivary glands. Genetic mosaic studies indicated that fish function is required for the growth or survival of imaginal cells, and the expression of engrailed and wingless. Ectopic expression of Fish protein resulted in severe disruption of adult structures; legs and antennae were truncated and eye formation was suppressed. These morphological defects were correlated with altered expression patterns of the wingless, decapentaplegic, and bric-a-brac genes. Finally, analysis of truncated versions of Fish protein indicated that the HMG domain was sufficient for Fish nuclear localization and that removal of the transcriptional activation domain did not eliminate Fish function. While Sox proteins have been shown to be important for eye and limb formation in vertebrates, these data provide the first evidence for Sox protein functions in appendage development in invertebrates.
Animals↗
Clastogenic effect of ginger rhizome in mice.
The present study focuses on the clastogenic effect of ginger rhizome. Crude aqueous extracts of ginger were gavaged at doses of 0. 5, 1, 2, 5, 10 g/kg body weight and ginger oil (0.625, 1.250 and 2. 50 ml/kg body weight) was administered by intraperitoneal injection to male mice. Chromosome damage was studied in a preparation made from bone marrow cells following colchicine injection to all mice and examination of the cells after pretreatment in hypotonic solution, fixation, air drying and staining in Giemsa solution. Attention is drawn to the weakness of the clastogenic activity expressed by the ginger extract. In comparison ginger oil gave a higher frequency of chromosomal aberrations. It is suggested therefore, that the extract may contain substance(s) that suppress clastogenesis in the bone marrow cells of mice.
Animals↗
In vivo cytogenetic studies on blends of aspartame and acesulfame-K.
Aspartame and acesulfame-K, non-nutritive sweeteners, are permitted individually in diets and beverages. These sweeteners of different classes, used in combination, have been found to possess a synergistic sweetening effect. Whether they also have a synergistic genotoxic effect is unknown. Swiss Albino male mice were exposed to blends of aspartame (3.5, 35, 350mg/kg body weight) and acesulfame-K (1.5, 15 and 150mg/kg body weight) by gavage. Bone marrow cells isolated from femora were analysed for chromosome aberrations. Statistical analysis of the results show that aspartame in combination with acesulfame-K is not significantly genotoxic.
Animals↗