An evaluation of transient elastography in the discrimination of HBeAg-negative disease from inactive hepatitis B carriers

Liver biopsy is frequently required in HBeAg-negative disease to determine the stage of fibrosis. It can be difficult to distinguish cohorts with undetectable HBeAg who may have varying degrees of fibrosis due to different stages of disease. We have assessed the utility of transient elastography (TE) to evaluate differences in HBeAg-negative patients. A total of 220 HBsAg-positive individuals were studied: 125 (group 1) had an inactive HBsAg carrier state and 95 (group 2) were HBeAg-negative, anti-HBe-positive patients with persistently or intermittent elevation of alanine aminotransferase (ALT) and/or HBV DNA >10(5) copies/mL. Mean stiffness was 4.83 +/- 1.2 kPa in group 1 vs 8.53 +/- 6 kPa in group 2 (P < 0.001); statistically significant differences were also found between AST/ULN ALT/ULN ratios, HBV DNA in group 1 vs group 2, respectively (P < 0.001). In the multivariate analysis, the only variable independently associated with the stage of fibrosis was the stiffness. This study shows that mean hepatic stiffness by elastography is significantly lower in patients with inactive hepatitis B compared to those with HBeAg-negative disease. The procedure is a useful adjunct to diagnosis to confirm a clinical pattern of disease, and for more selective use of liver biopsy before considering antiviral therapy.

Outcome predictors for non-invasive positive pressure ventilation in acute respiratory failure

BACKGROUND

Noninvasive positive pressure ventilation (NIPPV) has emerged as a significant advancement in the management of acute respiratory failure.

OBJECTIVE

To identify factors, based on clinical and laboratory parameters, for predicting the outcome of NIPPV in patients with acute respiratory failure.

MATERIALS AND METHODS

Fifty patients were included in the study. Inclusion criteria were RR>30 breaths/ min, PaO2<60mmHg, PaO2/FiO2<300, pCO2< or = 45mmHg and signs of increased work of breathing. Baseline clinical parameters and arterial blood gas (ABG) were recorded before initiating NIPPV. Clinical parameters including heart rate, respiratory rate, oxygen saturation and ABG was revaluated at 1, 4, 12, 24 hrs after initiation of NIPPV. Change in these parameters and need for intubation was evaluated.

RESULTS

Of the 50 patients, 37 (74%) showed clinical and ABG improvement. Out of 13 (26%) patients who failed to respond, 7 (52%) needed endotracheal intubation within 1 hr. There was significant improvement in clinical and ABG parameters within 1st hr in success group and these parameters continues to improve even after 4 hrs of NIPPV treatment (p<0.05). Failure group had higher baseline heart rate than success group (p<0.05).

CONCLUSION

Determination of baseline clinical factors such as heart rate and respiratory rate, available at the time of initiation and after a short period, can predict the likelihood of success or failure of NIPPV. As a result, delay in intubation can be avoided which itself is associated with significant mortality.

Techno-economic evaluation of soil-aquifer treatment using primary effluent at Ahmedabad, India

A pilot study was carried out in Sabarmati River bed at Ahmedabad, India for renovation of primary treated municipal wastewater through soil aquifer treatment (SAT) system. The infrastructure for the pilot SAT system comprised of two primary settling basins, two infiltration basins and two production wells located in the centre of infiltration basins for pumping out renovated wastewater. The performance data indicated that SAT has a very good potential for removal of organic pollutants, nutrients as well as bacteria and viruses. The SAT system was found to be more efficient and economical than the conventional wastewater treatment systems and hence recommended for adoption. A salient feature of the study is the introduction of biomat concept and its contribution in the overall treatment process.

Organization of the multiple coenzymes and subunits and role of the covalent flavin link in the complex heterotetrameric sarcosine oxidase

Heterotetrameric (alphabetagammadelta) sarcosine oxidase from Corynebacterium sp. P-1 (cTSOX) contains noncovalently bound FAD and NAD(+) and covalently bound FMN, attached to beta(His173). The beta(His173Asn) mutant is expressed as a catalytically inactive, labile heterotetramer. The beta and delta subunits are lost during mutant enzyme purification, which yields a stable alphagamma complex. Addition of stabilizing agents prevents loss of the delta but not the beta subunit. The covalent flavin link is clearly a critical structural element and essential for TSOX activity or preventing FMN loss. The alpha subunit was expressed by itself and purified by affinity chromatography. The alpha and beta subunits each contain an NH(2)-terminal ADP-binding motif that could serve as part of the binding site for NAD(+) or FAD. The alpha subunit and the alphagamma complex were each found to contain 1 mol of NAD(+) but no FAD. Since NAD(+) binds to alpha, FAD probably binds to beta. The latter could not be directly demonstrated since it was not possible to express beta by itself. However, FAD in TSOX from Pseudomonas maltophilia (pTSOX) exhibits properties similar to those observed for the covalently bound FAD in monomeric sarcosine oxidase and N-methyltryptophan oxidase, enzymes that exhibit sequence homology with beta. A highly conserved glycine in the ADP-binding motif of the alpha(Gly139) or beta(Gly30) subunit was mutated in an attempt to generate NAD(+)- or FAD-free cTSOX, respectively. The alpha(Gly139Ala) mutant is expressed only at low temperature (t(optimum) = 15 degrees C), but the purified enzyme exhibited properties indistinguishable from the wild-type enzyme. The much larger barrier to NAD(+) binding in the case of the alpha(Gly139Val) mutant could not be overcome even by growth at 3 degrees C, suggesting that NAD(+) binding is required for TSOX expression. The beta(Gly30Ala) mutant exhibited subunit expression levels similar to those of the wild-type enzyme, but the mutation blocked subunit assembly and covalent attachment of FMN, suggesting that both processes require a conformational change in beta that is induced upon FAD binding. About half of the covalent FMN in recombinant preparations of cTSOX or pTSOX is present as a reversible covalent 4a-adduct with a cysteine residue. Adduct formation is not prevented by mutating any of the three cysteine residues in the beta subunit of cTSOX to Ser or Ala. Since FMN is attached via its 8-methyl group to the beta subunit, the FMN ring must be located at the interface between beta and another subunit that contains the reactive cysteine residue.

Characterization of the FAD-containing N-methyltryptophan oxidase from Escherichia coli

N-Methyltryptophan oxidase (MTOX) is a flavoenzyme that catalyzes the oxidative demethylation of N-methyl-L-tryptophan and other N-methyl amino acids, including sarcosine, which is a poor substrate. The Escherichia coli gene encoding MTOX (solA) was isolated on the basis of its sequence homology with monomeric sarcosine oxidase, a sarcosine-inducible enzyme found in many bacteria. These studies show that MTOX is expressed as a constitutive enzyme in a wild-type E. coli K-12 strain, providing the first evidence that solA is a functional gene. MTOX expression is enhanced 3-fold by growth on minimal media but not induced by N-methyl-L-tryptophan, L-tryptophan, or 3-indoleacrylate. MTOX forms an anionic flavin semiquinone and a reversible, covalent flavin-sulfite complex (K(d) = 1.7 mM), properties characteristic of flavoprotein oxidases. Rates of formation (k(on) = 5.4 x 10(-3) M(-1) s(-1)) and dissociation (k(off) = 1.3 x 10(-5) s(-1)) of the MTOX-sulfite complex are orders of magnitude slower than observed with most other flavoprotein oxidases. The pK(a) for ionization of oxidized FAD at N(3)H in MTOX (8.36) is two pH units lower than that observed for free FAD. The MTOX active site was probed by characterization of various substrate analogues that act as competitive inhibitors with respect to N-methyl-L-tryptophan. Qualitatively similar perturbations of the MTOX visible absorption spectrum are observed for complexes formed with various aromatic carboxylates, including benzoate, 3-indole-(CH(2))(n)-CO(2)(-) and 2-indole-CO(2)(-). The most stable complex with 3-indole-(CH(2))(n)-CO(2)(-) is formed with 3-indolepropionate (K(d) = 0.79 mM), a derivative with the same side chain length as N-methyl-L-tryptophan. Benzoate binding is enhanced upon protonation of a group in the enzyme-benzoate complex (pK(EL) = 6.87) but blocked by ionization of a group in the free enzyme (pK(E) = 8.41), which is attributed to N(3)H of FAD. Difference spectra observed for the aromatic carboxylate complexes are virtually mirror images of those observed with sarcosine analogues (N,N'-dimethylglycine, N-benzylglycine). Charge-transfer complexes are formed with 3-indoleacrylate, pyrrole-2-carboxylate, and CH(3)XCH(2)CO(2)(-) (X = S, Se, Te).

N-methyltryptophan oxidase from Escherichia coli: reaction kinetics with N-methyl amino acid and carbinolamine substrates

N-Methyltryptophan oxidase (MTOX), a flavoenzyme from Escherichia coli, catalyzes the oxidative demethylation of N-methyl-L-tryptophan (k(cat) = 4600 min(-1)). Other secondary amino acids (e.g., sarcosine) are oxidized at a slower rate. We have identified carbinolamines as a new class of alternate substrate. MTOX oxidation of the carbinolamine formed with L-tryptophan and formaldehyde yields N-formyl-L-tryptophan in a relatively slow reaction that does not compete with turnover of MTOX with N-methyl-L-tryptophan. Double reciprocal plots with N-methyl-L-tryptophan as the varied substrate are nearly parallel, but the slopes show a small, systematic variation depending on the oxygen concentration. N-Benzylglycine, a dead-end competitive inhibitor with respect to N-methyl-L-tryptophan, acts as a noncompetitive inhibitor with respect to oxygen. The results are consistent with a modified ping pong mechanism where oxygen binds to the reduced enzyme prior to dissociation of the imino acid product. MTOX is converted to a 2-electron reduced form upon anaerobic reaction with N-methyl-L-tryptophan, sarcosine, or the carbinolamine formed with L-tryptophan and formaldehyde. No evidence for a detectable intermediate was obtained by monitoring the spectral course of the latter two reactions. MTOX reduction with thioglycolate does, however, proceed via a readily detectable anionic, flavin radical intermediate. The reductive half-reaction with sarcosine at 4 degrees C exhibits saturation kinetics (k(lim) = 6.8 min(-1), K = 39 mM) and other features consistent with a mechanism in which a nearly irreversible reduction step (E(ox).S --> E(red).P) (k(lim)) is preceded by a rapidly attained equilibrium (K) between free E and the E.S complex. The 21 degrees C temperature difference can reasonably account for the 3.6-fold lower value obtained for k(lim) as compared with turnover at 25 degrees C (k(cat) = 24.5 min(-1)), suggesting that sarcosine is oxidized at a kinetically significant rate under anaerobic conditions and the reductive half-reaction is rate-limiting during turnover. These conclusions are, however, difficult to reconcile with steady-state kinetic patterns obtained with sarcosine that are consistent with a rapid equilibrium ordered mechanism with oxygen as the first substrate. The basis for the apparent stability of the MTOX.oxygen complex (K(d) = 72 microM) is unknown.

Isolation and characterization of a Pseudomonas sp. strain PH1 utilizing meta-aminophenol

Pseudomonas sp. strain PH1 was isolated from soil contaminated with pharmaceutical and dye industry waste. The isolate PH1 could use m-aminophenol as a sole source of carbon, nitrogen, and energy to support the growth. PH1 could degrade up to 0.32 mM m-aminophenol in 120 h, when provided as nitrogen source at 0.4 mM concentration with citrate (0.5 mM) as a carbon source in the growth medium. The presence of ammonium chloride as an additional nitrogen source repressed the degradation of m-aminophenol by PH1. To identify strain PH1, the 16S rDNA sequence was amplified by PCR using conserved eubacterial primers. The FASTA program was used to analyze the 16S rDNA sequence and the resulting homology patterns suggested that PH1 is a Pseudomonas.

Amputations associated with arteriovenous access

This study was performed to investigate the common characteristics of hemodialysis patients who need upper limb amputations. An index case was identified and involved questioning physicians and reviewing hospital and office records. Hemodialysis patients who have diabetes and leg amputations are at high risk for ischemic episodes that may lead to amputation of the arm, distal to the arteriovenous access site.

Structure of the flavocoenzyme of two homologous amine oxidases: monomeric sarcosine oxidase and N-methyltryptophan oxidase

Monomeric sarcosine oxidase (MSOX) and N-methyltryptophan oxidase (MTOX) are homologous enzymes that catalyze the oxidative demethylation of sarcosine (N-methylglycine) and N-methyl-L-tryptophan, respectively. MSOX is induced in various bacteria upon growth on sarcosine. MTOX is an E. coli enzyme of unknown metabolic function. Both enzymes contain covalently bound flavin. The covalent flavin is at the FAD level as judged by electrospray mass spectrometry. The data provide the first evidence that MTOX is a flavoprotein. The following observations indicate that 8alpha-(S-cysteinyl)FAD is the covalent flavin in MSOX from Bacillus sp. B-0618 and MTOX. FMN-containing peptides, prepared by digestion of MSOX or MTOX with trypsin, chymotrypsin, and phosphodiesterase, exhibited absorption and fluorescence properties characteristic of an 8alpha-(S-cysteinyl)flavin and could be bound to apo-flavodoxin. The thioether link in the FMN-containing peptides was converted to the sulfone by performic acid oxidation, as judged by characteristic absorbance changes and an increase in flavin fluorescence. The sulfone underwent a predicted reductive cleavage reaction upon treatment with dithionite, releasing unmodified FMN. Cys315 was identified as the covalent FAD attachment site in MSOX from B. sp. B-0618, as judged by the sequence obtained for a flavin-containing tryptic peptide (GAVCMYT). Cys315 aligns with a conserved cysteine in MSOX from other bacteria, MTOX (Cys308) and pipecolate oxidase, a homologous mammalian enzyme known to contain covalently bound flavin. There is only one conserved cysteine found among these enzymes, suggesting that Cys308 is the covalent flavin attachment site in MTOX.

Reduction of 4-hydroxynonenal and 4-hydroxyhexenal by retinal aldose reductase

Aldose reductase has been purified to homogeneity from bovine retina. It has an apparent molecular weight of 32,000 daltons and shares immunological and kinetic properties with the much studied aldose reductases purified from various sources. Retinal aldose reductase displays a K(m) of approximately 40 microM with 4-hydroxynonenal and 4-hydroxyhexenal, the oxidation end products of arachidonic and docosahexanoeic acids, respectively. It therefore appears that aldose reductase may constitute a major detoxification route of these toxic aldehydes in the retina.

Oxidative defense enzyme activity and mRNA levels in lenses of diabetic rats

This study examines the mRNA expression and enzyme activity of oxidative defense enzymes during the course of streptozotocin-induced hyperglycemic cataract development. Diabetes was produced in 5-wk-old male Sprague-Dawley rats by administering streptozotocin ip and mRNA expression and enzyme activity were monitored on d 4, 8, 12, 16, 20, 40, 60, and 80; concomitantly, the onset and progress of cataract was followed by digital image analysis. Peak enzyme activity and mRNA expression were attained between d 20 and 40. Although catalase and glutathione peroxidase maintained high levels of mRNA expression through d 60, induction of CuZu-superoxide dismutase was transient, with the activity and mRNA levels returning to baseline values by d 40. There was a pronounced increase in aldose reductase activity, which gradually declined to basal levels by d 60; however, the mRNA levels remained unaltered. Other changes included a progressive loss of lenticular transparency, which declined to 40% of control by d 80. The role of antioxidant defense enzymes and, more interestingly, aldose reductase in combating oxidative stress in diabetic cataractogenesis is discussed.

Diabetes-induced apoptosis in rat kidney

Oxidative stress has been suggested to play a crucial role in the pathogenesis of diabetic complications including nephropathy. However, the exact mechanism of diabetic nephropathy is still not clearly understood. Since oxidative stress in known to be a major component in the induction of apoptosis, we investigated the occurrence of apoptosis in diabetic rat kidney. The status of oxidative stress was determined as thiobarbituric acid reactive substances (TBARS). The TBARS in the control and diabetic rat kidney were 2.00 +/- 0.963 and 3.83 +/- 0.715 mumol/mg protein, respectively (P < 0.05). Apoptosis was determined by evaluating the DNA fragmentation using an enzyme-linked immunoassay and in situ end labeling. DNA fragmentation increased approximately fourfold in diabetic rat kidney compared to the normal kidney (P < 0.05). Apoptag in situ labeling displayed negligible apoptosis in nondiabetic kidney while significant areas of apoptosis were observed in diabetic kidney. Our results suggest that increased oxidative stress in diabetic kidney could induce apoptosis, which may contribute to the development of diabetic nephropathy.

Semi-quantitation of mRNA by polymerase chain reaction. Levels of oxidative defense enzymes and aldose reductase in rat lenses cultured in hyperglycemic or oxidative medium

The high sensitivity of reverse transcriptase-polymerase chain reaction for detecting low copy number mRNA transcripts has been standardized to analyze the mRNA profiles of catalase, glutathione peroxidase, CuZn-superoxide dismutase and aldose reductase, with respect to the housekeeping gene cyclophilin, in rat lenses cultured in hyperglycemic (50mM glucose) or oxidative (100 microM H2O2) media for 24, 40 and 60 hr. In response to hyperglycemia mRNA expression of catalase appeared to be inhibited at 24 hr but attained normal levels by 40 hr. On the other hand, mRNA levels of catalase were higher than normal between 40 and 60 hr in the presence of H2O2. Glutathione peroxidase mRNA abundance although enhanced in response to both hyperglycemia as well as H2O2-induced stress, displayed opposite trends with time-an increase from 24-60 hr due to hyperglycemia and a decrease to normal by 60 hr in the presence of H2O2. In contrast, CuZn-superoxide dismutase was inhibited at 50 mM glucose achieving baseline levels by 60 hr, while H2O2 elicited an induction at 24 hr which waned to basal levels by 60 hr. Interestingly, aldose reductase was unaffected by hyperglycemia but showed an appreciable increase with time upon exposure of the lens to H2O2. The role of these enzymes in cataractogenesis with regard to their respective mRNA levels is discussed.

A simple device for the concentration and detection of enterovirus, hepatitis E virus and rotavirus from water samples by reverse transcription-polymerase chain reaction

A simultaneous concentration of enteroviruses, hepatitis E virus, and rotavirus from drinking water samples through a filtration column filled with granular activated carbon (GAC) was achieved. Urea-arginine phosphate buffer (UAPB) as an eluent at pH 9.0 was used for effective desorption and elution of viruses from GAC. Further concentration of viruses with magnesium chloride enabled nucleic acid extraction, cDNA synthesis, amplification with a specific set of primers for enterovirus, hepatitis E virus and rotavirus. Polymerase chain reaction (PCR) products were then confirmed by Southern transfer and hybridization with the relevant probes. The efficacy of the protocol was established with 100 1 of water samples seeded with poliovirus-1, providing 74% recovery in granular activated carbon based UAPB-RT-PCR. The GAC-based method for concentration of viruses from water samples was preferred, despite its somewhat lower efficacy compared to 80% in membrane filter based UAPB-RT-PCR protocol, due to the specific requirements of short-time and savings in cost of analyses. The protocol was used for the detection of waterborne viruses from 24 drinking water sources in urban areas of New Delhi. Direct isolation of viruses from water samples revealed that the 4 samples were positive for enteroviruses, two for hepatitis E virus, and 10 samples for rotavirus. One sample was positive for both hepatitis E virus and rotavirus, and another for all the 3 types of viruses.

Calcium-mediated disintegrative globulization of isolated ocular lens fibers mimics cataractogenesis

Single viable fiber cells have been isolated from the cortex of rat ocular lens by proteolytic digestion of the intact lens in calcium-free media. In isomolar sucrose, the isolated cells maintain their fiber-shaped morphology and exclude trypan blue. The surface morphology of the isolated fiber cells appears to be largely unaffected by the isolation procedure. The concentrations of adenine nucleotides, GSH, GSSG and the rate of glycolysis in the isolated fiber cells were comparable to those in the cortex. Upon perfusion of the tissue chamber with Ringer's solution, the fiber cells undergo a series of transformations, beginning with cell swelling, periodic blebbing along the longitudinal cellular axis, and eventual disintegration of the fiber into a number of resealed globules or round cells which resemble light-scattering areas in human cortical and supranuclear cataract. This disintegrative globulization of the fiber cells appears to be mediated by calcium influx, as it was prevented or delayed by a reduction in extracellular calcium concentration, verapamil or lanthanum. Since disturbances in calcium homeostasis are associated with various forms of cataract, such Ca(2+)-mediated disintegrative globulization of the fiber cells may be responsible for the formation of light scattering centers during cataractogenesis.

ATP synthase subunit C storage in the polymorphonucleocytes of late infantile and juvenile batten patients

In late infantile and juvenile forms of neuronal ceroid lipofuscinosis, commonly known as Batten disease (BD). ATP synthase subunit c accumulates in the lysosomes of neural cells. By using polyclonal antibodies, raised against bovine liver subunit c and an image analysis system for the quantification of antibody-linked alkaline phosphatase reaction, we have demonstrated that polymorphonucleocytes (PMN) from a late infantile and a juvenile BD patient stored several-fold more subunit c as compared to normal PMN.

Immunotechnological trends in radioimmunotargeting: from 'magic bullet' to 'smart bomb'

The impact of recent advances in the chemical and genetic engineering manipulations of antibodies on radioimmunotargeting is reviewed both in relation to radioimmunoscintigraphy and radioimmunotherapy. The resulting trends are: (1) the linking of parts of the mouse/rat and human antibody molecule; (2) the creation of molecules with dual antigen or multiple antigen recognition capabilities; (3) the making of smaller and smaller antigen recognition molecules; and (4) the development of molecules with dual capabilities, e.g. antigen recognition and enzyme activity. The various methods of creating antibodies in vitro are reviewed with reference to bacteria, using phage selection and a combinatorial library, mammalian cells, yeast cells and, finally, mice containing giant yeast artificial chromosomes. The advantages and disadvantages of smaller fragments as well as of the human anti-mouse antibody (HAMA) reaction are discussed and the need for early clinical evaluation and widespread availability of the newer antibodies is emphasized. It is envisaged that these immunotechnological advances will permit the large-scale production of precisely engineered humanized antibodies, and the specificity and affinity rate constant of these antibodies can be optimized using in vitro phage selection as well as by computer modelling where the stereo chemistry of the antigen is known precisely.

ATP-dependent transport of glutathione-N-ethylmaleimide conjugate across erythrocyte membrane

Prevailing controversies regarding the identity and nature of S-(2,4-dinitrophenyl) glutathione (Dnp-SG) and GSSG transport system(s) led us to examine xenobiotic-SG transport from human erythrocytes and into inside-out vesicles (IOV) using N-ethyl-maleimide-glutathione conjugate (NEM-SG) as substrate. Efflux of NEM-SG from intact erythrocytes was linear over a period of 4 h, occurred against a concentration gradient, and required energy. No transport of NEM-SG was observed when endogenous ATP was exhausted by preincubation of the erythrocytes for 8 h at 37 degrees C in the absence of glucose. When cellular GSH was partially conjugated with NEM to form 1.5 and 1.0 mM NEM-SG, and the remaining GSH was oxidized with t-butylhydroperoxide to generate 0.2 and 0.4 mM GSSG, respectively, the extrusion of NEM-SG from erythrocytes was not inhibited. The kinetics of NEM-SG transport in intact erythrocytes were monophasic; the Km NEM-SG was 0.62 mM +/- 0.24. However, in IOV two components of NEM-SG transport with respect to NEM-SG and ATP were discernible. The low Km for NEM-SG was 5.6 +/- 1.51 microns with a Vmax of 7.30 +/- 0.69 nmol/mg protein/h and the high Km for NEM-SG was 1.35 +/- 0.14 mM with a Vmax of 65.1 +/- 3.5 nmol/mg protein h. With respect to ATP, the NEM-SG transport had a low Km of 0.12 +/- 0.004 mM and a high Km of 0.52 +/- 0.052 mM. Both components of NEM-SG transport were inhibited by fluoride, o-vanadate, p-hydroxymercuribenzoate and 5,5'-dithiobis(2-nitrobenzoic acid). However, NEM (1 mM) inhibited only the high Km transport. GSH stimulated the low Km transport 1.7-fold. Both low and high Km components of NEM-SG transport significantly declined when ATP was substituted with CTP, UTP, or GTP. GSSG and Dnp-SG competitively inhibited the low Km NEM-SG transport (Ki = 18.5 +/- 2.9 and 1.32 +/- 0.16 microns, respectively) whereas the high Km transport was inhibited by Dnp-SG but not by GSSG. These findings suggest that glutathione S-conjugates may be transported out of erythrocytes by both the high and the low Km mechanisms, the latter being shared by GSSG.

High-performance liquid chromatography method for the determination of protein-glutathione mixed disulfide

We have developed an efficient and sensitive method for the quantification of picomole quantities of protein-glutathione and protein-cysteine mixed disulfides in ocular lens. Performic acid oxidation releases glutathione and cysteine from the protein-mixed disulfides as glutathione sulfonic acid and cysteic acid, respectively. The sulfonic acids are derivatized with phenylisothiocyanate, and the phenylthiocarbamyl derivatives are separated by HPLC using a reversed-phase ODS column, equilibrated with 0.14 M sodium acetate, containing 0.1% triethylamine and 6% acetonitrile.

Trolox protects hyperglycemia-induced cataractogenesis in cultured rat lens

Hyperglycemia-induced cataractogenesis has been studied in rat lenses cultured in 50 mM glucose using an inverted microscope connected with a Universal C-mount and a CCD camera. Digital images were acquired and the opacity was determined by quantitating the transmitted light. Antioxidants, butylated hydroxy toluene (BHT) and 6-hydroxy-2,5,7,8-tetramethenyl-chroman-2-carboxylic acid (Trolox) provided good protection against 50 mM glucose-induced cataractogenesis in rat lenses for upto 8 days. Sorbitol levels in the 50 mM glucose+antioxidant groups were approximately 1.5 mM fold higher than in 50 mM glucose. The results, besides further demonstrating that oxidative damage is the major mechanism of sugar-induced cataractogenesis, show that Trolox or related amphipathic compounds could be of therapeutic use in the prevention of diabetic cataracts.

The effects of self-hypnosis for children with cystic fibrosis: a pilot study

This pilot study assessed the effects of self-hypnosis on psychological and physiological functioning of children ages 7 to 18 with Cystic Fibrosis (N = 12). The study used a pre- and posttest design, repeated measures, and control group. Control and experimental groups were matched for age and clinical severity. The experimental group demonstrated significant changes in locus of control, health locus of control, and self-concept. State anxiety scores did not differ significantly, but changes in trait anxiety distinguished the experimental group from the control group. The experimental group also demonstrated significant increase in peak expiratory flow rates using an air flow meter immediately after self-hypnosis when compared to the control group. Generalizability of the results is discussed in terms of the small sample size. Recommendations are offered for future studies with larger samples and variations in procedure.

Linking radiosilver to monoclonal antibodies reduced by ascorbic acid. Comparison of results with stable silver using gravimetric technique and silver 110-M using radiotracer technique

Radiosilver-111 and Radiogold-199 were proposed by us (1) as suitable isotopes for radioimmunotherapy in areas such as India by reason of their suitable half-lives and B-emissions (Ag-111 T1/2 = 7.45 d and Au-199 T1/2 = 3.15 d). Since silver is monovalent, it is difficult to link to conventional bifunctional chelates. We therefore explored the use of sulfur-based linkers (2). Encouraged by the Thakur and De Fulvio Technique (3) of linking technetium to disulfide groups in antibodies reduced by ascorbic acid that is eminently biocompatible, we have explored the linkage of silver to immunoglobulin reduced by ascorbic acid. The linkage of silver was assessed with stable Ag-108 using dialysis to quantify the free silver after the reaction of silver and reduced immunoglobulins in various molar ratios (1:1, 1:2, 1:5, 1:10). The silver quantity was estimated gravimetrically after precipitation as chloride. It was observed that using these molar ratios there was negligible silver efflux into the dialysate, suggesting stable linkage. We also assessed the linkage using Ag-110M as radiotracer. The comparative results with the two techniques are described.

Removal of endotoxin from antibody preparations for clinical use. Assessment of polymyxin-sepharose CNBr affinity chromatography

Despite attempts to maintain asepsis, good manufacturing practices, and the use of terminal sterilization by millipore filtration, the nuclear practitioner is always worried about the possibility of endotoxin contamination. Methods, such as ion-exchange chromatography, have been tried for removing endotoxins during the preparation of radiolabeled antibodies, and so on. As suggested by Stevenson (1990), we evaluated the Issekutz technique (1) of endotoxin removal by affinity chromatography using a polymyxin cyanogen bromide (CNBr) Sepharose column. The endotoxin content of millipore filtrates of heat killed/sonicated suspensions of Pseudomonas pyocyaneus, E. coli were measured using a Sigma (St. Louis, MO) Endotoxin Assay Kit before and after filtration through such columns and compared with the results obtained using gel exclusion and ion-exchange columns of the same length and diameter. Reduction of endotoxin content to undetectable levels by the polymyxin column was observed. The use of such columns for terminal endotoxin removal analogous to terminal sterilization is advocated especially when developing a radiopharmaceutical such as radiolabeled antibodies for in house use.

Detection of hepatitis E virus in raw and treated wastewater with the polymerase chain reaction

The main objective of this study was to determine the applicability of the polymerase chain reaction (PCR) to detection of hepatitis E virus (HEV) in sewage treatment plants and establishment of the prevalence of hepatitis viral diseases in a population. Epidemics of HEV infection because of inadequate public sanitation have been reported in several developing countries. A procedure for concentration of HEV in sewage samples through adsorption to membrane filters, elution with urea-arginine phosphate buffer, and subsequent reconcentration with magnesium chloride enabled us to concentrate HEV to volumes in the microliter range. HEV-specific cDNA was prepared by reverse transcription of the total RNA extracted from samples. Specific DNA amplification by PCR in combination with slot blot hybridization was used to demonstrate the presence of HEV in sewage samples from the inlets and outlets of three sewage treatment plants. The assay was specific for HEV, and a 240-bp amplified product was visualized by ethidium bromide fluorescence. Sewage samples adjusted to pH 5.0 for adsorption of viruses to membrane filters were PCR positive, while samples adjusted to pH 3.5 were PCR negative.

Pattern visual evoked potentials in cases of ambiguous acuity loss

Thirty patients were referred to our visual evoked potential laboratory with complaints of profound acuity loss in one or both eyes. However, the objective ophthalmologic findings were normal, including pupillary reaction, and anterior segment and fundus examinations. Transient visual evoked potentials to a 2.3-c/deg sinusoidal grating pattern were found to be present in 26 of these 30 patients. Visual evoked potentials may be used as a measure of afferent pathway integrity.

Characteristics of a cytosolic arylacylamidase metabolizing thiacetazone

The N-deacetylation of thiacetazone, an antitubercular drug possessing hepatotoxic side effects, by an exclusively cytosolic arylacylamidase has been identified in the liver and kidney of rat by monitoring the appearance of its metabolite p-aminobenzaldehydethiosemicarbazone spectrophotometrically. Studies toward its characterization in liver cytosol revealed that the hydrolase possesses a broad pH optimum ranging from 6.0 to 9.0. The Km and Vmax values for the N-deacetylation of thiacetazone are 5.7 x 10(-4) M and 0.123 nmol of p-aminobenzaldehydethiosemicarbazone formed/min/mg cytosolic protein, respectively. The ability to metabolize thiacetazone was the same in the livers of cat, mouse and human, but lagged significantly in that of rat. Among the biodegradable esters examined as potential rivals of thiacetazone, only aspirin competitively inhibited thiacetazone hydrolysis (Ki = 2.1 x 10(-4) M). Discrimination of cytosolic thiacetazone N-deacetylase from nonspecific p-nitrophenylacetate esterase on the basis of their differential reactivity toward various inhibitors and activators disclosed that low concentrations of p-chloromercuribenzoate, AgNO3 and CuSO4 selectively undermine the activity of thiacetazone N-deacetylase, whereas SKF 525-A, ZnSO4 and FeCl3 are effective inhibitors of p-nitrophenylacetate esterase. However, divalent ions (Ca++ and Mg++) and EDTA failed to alter the activity of the enzyme. Besides, thiacetazone metabolism was significantly retarded upon exposure to malathion. Notably, Nal/Kl stimulated the N-deacetylase activity as a function of iodide concentration. The hydrolysis of thiacetazone in the liver and kidney remained uninduced by phenobarbital, 3-methylcholanthrene or benzo(a)pyrene (80 mg/kg, p.o., 8 days).(ABSTRACT TRUNCATED AT 250 WORDS)

Anoxygenic degradation of aromatic substances byRhodopseudomonas palustris

Three strains of the phototrophic purple nonsulfur bacterium Rhodopseudomonas palustris were isolated from different environments and were evaluated for their aromatic degradative potential under phototrophic conditions. All three strains (PFR1, PNR4, and MRL1) utilized benzoate, 4-hydroxybenzoate, 4-aminobenzoate, 4-aminophenol, cinnamate, ferulate, phloroglucinol, and 4-dimethylaminobenzaldehyde in the absence of exogenous CO2. 4-Aminobenzoate and 4-aminophenol served as a carbon and nitrogen source for all the three strains. Utilization of 4-aminophenol was enhanced in the presence of 4-hydroxybenzoate. Salicylate was utilized by PFR1 and MRL1 strains, and phenol was utilized by the MRL1 strain only in the presence of exogenous CO2.

Participatory health communication and action through women groups in rural areas

Twelve women groups in 10 villages of block Beri were identified and activized through participatory health communication actions for mother and child development. Women could undertaken responsibilities on key health problems concerning mothers and children. In these villages over 58% of antenatal mothers now used home made clean packets for delivery and chose right place for delivery. Most of them (60%) now initiate breast feeding immediately after delivery as against 23% in the year 1988. Over 54% of women now drink chlorinated water and almost same proportion used sugar salt solution in diarrheal diseases. Thus women have become self reliant in chlorination of wells and pots as also in diarrheal diseases management. Practice of hand washing has been almost universalized.