Higher sustained virological response rates at 12 weeks in HIV-HCV co-infection; a tertiary centre experience.

OBJECTIVES: The advent of direct-acting antivirals (DAAs) has revealed high rates of sustained virological response at 12 weeks (SVR 12) in Hepatitis C (HCV) treatment. Since the introduction of DAAs, in our centre, 42% of patients treated for HCV are HIV co-infected. Our study aimed to identify the SVR 12 rates between this group and HCV mono-infected patients. METHODS: Retrospective data analysis of HCV mono-infection and HIV-HCV co-infection patients between 1st July 2015 and 30th November 2018, who had a SVR at 12 weeks post treatment. Co-infected patients were only referred for HCV treatment if they had well controlled HIV. Patients treated with Pegylated Interferon and Ribavirin were excluded. RESULTS: During this period, 724 patients were treated for HCV and had data on SVR 12. Of those, 303 (41.8%) were co-infected with HIV. The SVR 12 was achieved in 386 (91.6%) of the HIV negative patients and 288 (95%) of the HIV positive patients (χ²= 3.10 p = 0.078). Cirrhotic patients had poorer SVR 12 in both groups (90% in co-infection and 88.4% in HCV mono-infection). CONCLUSIONS: Our results demonstrate a higher SVR 12 in co-infected patients compared to patients with HCV mono-infection. We hypothesise that adherence to HIV treatment could increase compliance and success of HCV treatment.

Assessing Heterodera glycines-Resistant and Susceptible Cultivar Yield Response.

The soybean cyst nematode Heterodera glycines (SCN) is of major economic importance and widely distributed throughout soybean production regions of the United States where different maturity groups with the same sources of SCN resistance are grown. The objective of this study was to assess SCN-resistant and -susceptible soybean yield responses in infested soils across the north-central region. In 1994 and 1995, eight SCN-resistant and eight SCN-susceptible public soybean cultivars representing maturity groups (MG) I to IV were planted in 63 fields, either infested or noninfested, in 10 states in the north-central United States. Soil samples were taken to determine initial SCN population density and race, and soil classification. Data were grouped for analysis by adaptation based on MG zones. Soybean yields were 658 to 3,840 kg/ha across the sites. Soybean cyst nematode-resistant cultivars yielded better at SCN-infested sites but lost this superiority to susceptible soybean cultivars at noninfested sites. Interactions were observed among initial SCN population density, cultivar, and location. This study showed that no region-wide predictive equations could be developed for yield loss based on initial nematode populations in the soil and that yield loss due to SCN in our region was greatly confounded by other stress factors, which included temperature and moisture extremes.

A comparative study of two powered toothbrushes and one manual toothbrush in young adults.

The aim of this 3-group, 3-treatment, single-blind, parallel group study was to evaluate and compare the efficacies of the Philips/Jordan HP735 powered toothbrush, the Braun/Oral-B D7 powered toothbrush, and the Oral-B Advantage B35 manual toothbrush in young adults (18-25 years). Full mouth mean (SD) modified Turesky Plaque Index (PI) and the Löe & Silness Gingival Index (GI) were recorded at baseline. After 24 hours abstinence from oral hygiene, the PI was recorded and each subject was given one of the test brushes with detailed instructions for use. Each subject then brushed under supervision for 90 seconds, during which time mean (SD) toothbrushing forces (TBF) were recorded. PIs were recorded immediately after brushing, and the subjects were then discharged for 6 weeks to use the allocated toothbrush at home. After 6 weeks, PI, GI and TBF were again recorded. There were no significant differences (ANOVA) for PI and GI between groups at baseline, or for PI following brushing at 24 hours. After 6 weeks, the powered brushes produced lower mean PI (SD) scores than the manual brushes, but the differences were significant only at interproximal sites. Mean GI scores for the HP735 group were similar at baseline and at 6 weeks, although for the other brushes the GI scores actually increased over this period. Mean (SD) TBF (grams/force) at baseline and 6 weeks, respectively, for the brushes were; HP735 233 (205), D7 159 (58), B35 279 (122) (p = 0.026): HP735 194 (86), D7 141 (57), B35 297 (113) (p = 0.0001). The within-group variability for the HP735 TBF reduced considerably over 6 weeks, which is possibly because of the click-force threshold feature of this brush.

DNA sequence of both chromosomes of the cholera pathogen Vibrio cholerae.

Here we determine the complete genomic sequence of the gram negative, gamma-Proteobacterium Vibrio cholerae El Tor N16961 to be 4,033,460 base pairs (bp). The genome consists of two circular chromosomes of 2,961,146 bp and 1,072,314 bp that together encode 3,885 open reading frames. The vast majority of recognizable genes for essential cell functions (such as DNA replication, transcription, translation and cell-wall biosynthesis) and pathogenicity (for example, toxins, surface antigens and adhesins) are located on the large chromosome. In contrast, the small chromosome contains a larger fraction (59%) of hypothetical genes compared with the large chromosome (42%), and also contains many more genes that appear to have origins other than the gamma-Proteobacteria. The small chromosome also carries a gene capture system (the integron island) and host 'addiction' genes that are typically found on plasmids; thus, the small chromosome may have originally been a megaplasmid that was captured by an ancestral Vibrio species. The V. cholerae genomic sequence provides a starting point for understanding how a free-living, environmental organism emerged to become a significant human bacterial pathogen.

Soybean Cyst Nematode Reproduction in the North Central United States.

An experiment was conducted in Heterodera glycines-infested fields in 40 north central U.S. environments (21 sites in 1994 and 19 sites in 1995) to assess reproduction of this nematode. Two resistant and two susceptible soybean cultivars from each of the maturity groups (MG) I through IV were grown at each site in 6.1 m by 4 row plots. Soil samples were collected from each plot at planting and harvest and processed at Iowa State University to determine H. glycines initial (Pi) and final (Pf) population densities as eggs per 100 cm3 of soil. Overall, reproduction (Pf/Pi) of H. glycines on susceptible cultivars in all MG was similar. Reproduction was higher on MG III and IV susceptible cultivars than on those in MG I and II. Resistant MG I and II cultivars reduced nematode population densities more consistently than those in MG III and IV. Reproduction of the nematode was similar among sites within the same maturity zone (MZ), defined as the areas of best adaptation of the corresponding MG. Nonetheless, careful monitoring of nematode population densities is necessary to assess changes that occur over time in individual fields.

A comparative study of the Philips HP 735, Braun/Oral B D7 and the Oral B 35 Advantage toothbrushes.

The aim of this 3-group, 3-treatment, single-blind, parallel group study was to evaluate and compare the efficacies of the Philips/Jordan HP 735 powered toothbrush, the Braun/Oral B D7 powered toothbrush and the Oral B Advantage B35 manual toothbrush in a cohort of 75 young adults (18-25 years). Following an appointment for screening, full mouth mean (+/-sd) modified Turesky plaque index (PI) and Löe & Silness gingival index (GI) were recorded at baseline. After 24 h abstinence from all oral hygiene measures, PI was recorded and each subject was given one of the test brushes with detailed instructions for use. The subject then brushed under supervision for 90 s, during which time mean (+/-sd) toothbrushing forces (TBF) were recorded. PI were recorded immediately after supervised brushing and the subjects were then discharged for 6 weeks to use the allocated toothbrush at home. After 6 weeks, PI, GI and TBF were again recorded. Comparisons between the brushing groups for all parameters, at baseline, 24 h and 6 weeks were tested using ANCOVA. There were no significant differences for PI and GI between groups at baseline, or for PI following supervised brushing at 24 h. After 6 weeks subjects using the powered brushes had lower mean PI (+/-sd) scores than those using manual brushes but the differences were significant only at interproximal sites; HP 735 1.44 (0.52), D7 1.44 (0.53), B35 1.75 (0.51) (p=0.05). At 6 weeks, mean (+/-sd) GI were; HP 735 1.49 (0.21), D7 1.61 (0.21), B35 1.64 (0.22) (p=0.033). Mean GI scores for the HP 735 group were similar at baseline and at 6 weeks although for the other brushes, the GI scores actually increased over this period. Mean (+/-sd) TBF (grammes/force) at baseline and 6 weeks respectively for the brushes were; HP 735 233 (205), D7 159 (58), B35 279 (122) (p=0.026): HP 735 194 (86), D7 141 (57), B35 297 (113) (p=0.0001). The within-group variability for the HP 735 TBF reduced considerably over 6 weeks, a likely consequence of the click-force threshold feature of this brush.

Enumeration of flux routes through complex biochemical reactions.

In the present work, a general algorithm for enumeration of the flux routes via which a chemical species "flows" through a complex biochemical reaction is outlined and presented by way of a biological example, a kinetic model for potassium ion permeation through a voltage-gated ion channel. The algorithm is readily amenable to computer based implementation and when used in conjunction with an existing algorithm provides a convenient means for simulation of the equilibrium and steady-state isotope exchange kinetics of complex biochemical reactions.

Adsorption during Heat Treatment Related to the Thermal Unfolding/Aggregation of beta-Lactoglobulins A and B

Adsorption onto chromium surfaces during heat treatment (65-68°C) of beta-lactoglobulin A and B in phosphate buffer, pH 6.88, was investigated by in situ ellipsometry. Thermal unfolding and in situ heat-induced aggregation under the same conditions were studied by differential scanning calorimetry and dynamic light scattering, respectively. A lag phase was observed for buildup of the thickness of the adsorbed layer of beta-lactoglobulin A and B at 68°C. The lag period was found to increase with decreasing temperature. The difference in adsorption rate between the variants was found to be in agreement with the aggregation difference in solution, that is, the A variant aggregated more rapidly after a somewhat slower beginning. These results could be related to a difference in the thermal unfolding behavior. By applying a non-two state model the second of two transitions was suggested to involve the activation of the free sulfydryl group. The results indicated that fouling proceeds via attachment of aggregates with an activated free sulfydryl group through an interchange reaction with a disulfide bond in the adsorbed protein layer.

Thermal denaturation of beta-lactoglobulin: effect of protein concentration at pH 6.75 and 8.05.

Previous work on the thermal denaturation of beta-lactoglobulin at about neutral pH and concentrations generally above 50 mg/ml has shown that the temperature of the maximum in the thermogram increases only slightly with concentration. Likewise, there is little if any concentration dependence at acid pH over a wide concentration range. However, so far as we are aware, no work has been described on the thermal denaturation of beta-lactoglobulin in the physiological range of protein concentration and pH appropriate to milk. We report measurements at pH 6.75 and 8.05 in the concentration range 2-120 mg/ml and show that below about 50 mg/ml the position of the maximum becomes strongly dependent on concentration, passing through a minimum near 25 mg/ml and increasing towards the lowest concentrations where measurements were practicable. Moreover, the narrow, well defined and nearly symmetrical thermal transition observed at high protein concentrations contrasts with a broader and more asymmetric curve at lower concentrations. An explanation for the behaviour seen at the lower protein concentrations is suggested, based on the temperature- and concentration-dependent dissociation of the beta-lactoglobulin dimer and an associated conformational transition. The position of the maximum in the thermogram has a marked dependence on the rate of heating down to the lowest rate investigated of 10 degrees C per hour, showing the importance of slow kinetic effects in the denaturation of this protein.

A calbindin D9k mutant with reduced calcium affinity and enhanced cooperativity. Metal ion binding, stability, and structural studies.

In the native calcium-binding protein calbindin D9k (M(r) 8.700; 75aa; 2 EF-hands), the backbone carbonyl oxygen of Glu60 coordinates the Ca2+ ion in the C-terminal site (site II). The carboxylate group of the same residue forms a hydrogen bond to a water molecule that constitutes a Ca2+ ligand in the N-terminal site (site I). The mutant E60D, with the charge-conserving substitution Glu60-->Asp, has been prepared to study the role of Glu60 in subjoining the two Ca(2+)-binding sites and its role in the cooperative Ca2+ binding. Ca(2+)-binding studies of the mutant show that the overall affinity for calcium has decreased by a factor of 38 in comparison with wild-type calbindin D9k. The largest reduction is seen in the first macroscopic binding step. The Ca2+ affinities for both sites in the protein are reduced to a similar extent. In contrast, the mutation leads to a large increase in the cooperativity of calcium binding. Differential scanning calorimetry has been used to determine the thermal stability which is almost as high as in the wild-type protein. Cadmium binding has been assessed with 1H and 113Cd NMR. X-ray crystallographic studies of the E60D mutant in its calcium-bound form show very small structural changes relative to the wild-type protein. Almost all differences are within the error limits of the method. The largest crystallographic effects are seen in the crystal packing. Two E60D molecules with slightly different structure are found in the asymmetric unit in contrast to the single molecule in the wild-type crystal.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of tecogalan sodium on the development of the collateral circulation after acute arterial occlusion.

The survival of tissues distal to major arterial occlusions is critically dependent on the development of collateral blood vessels. The biochemical events fundamental to their evolution remain undefined. To determine the role of endogenous basic fibroblast growth factor in the development of the collateral circulation we evaluated the dose response to Tecogalan Sodium (DS-4152) in a rat model of hind limb ischaemia. Treatment with DS-4152 inhibited the recovery following acute arterial occlusion and impaired limb viability. The inhibitory effects were more pronounced in the calf than in the adductor muscles and tended to be more marked in the groups treated with the higher dose regimens. The results provide further evidence that collateral development and tissue recovery following acute arterial occlusion are dependent on endogenous basic fibroblast growth factor and that this dependence is greater in the more ischaemic, distal tissues.

The role of PDGF-BB on the development of the collateral circulation after acute arterial occlusion.

The survival of tissues in the presence of arterial occlusion is critically dependent on the development of collateral blood vessels. Identification of the biochemical mediators and their mechanism of action is fundamental to an understanding of the evolution of the collateral circulation. The ability of PDGF-BB to promote this was evaluated in an animal model of hind limb ischaemia. In order to obtain significant quantities of this mitogen for use in our animal model, human recombinant PDGF-BB was expressed in a Chinese Hamster Ovary (CHO) cell line. The transfected CHO cells produced 544 micrograms/l of PDGF-BB in serum free medium (SFM). The 30 kDa form of PDGF-BB was purified to homogeneity as judged by silver staining and amino-acid sequencing. Purified PDGF-BB was shown to be bioactive by a cell proliferation assay. The exogenous administration of PDGF-BB enhanced the recovery of blood flow after acute arterial occlusion. The results suggest that PDGF-BB may have therapeutic value in promoting collateral development following arterial occlusion.

Disulfide bonds in homo- and heterodimers of EF-hand subdomains of calbindin D9k: stability, calcium binding, and NMR studies.

The effect of decreased protein flexibility on the stability and calcium binding properties of calbindin D9k has been addressed in studies of a disulfide bridged calbindin D9k mutant, denoted (L39C + P43M + I73C), with substitutions Leu 39-->Cys, Ile 73-->Cys, and Pro 43-->Met. Backbone 1H NMR assignments show that the disulfide bond, which forms spontaneously under air oxidation, is well accommodated. The disulfide is inserted on the opposite end of the protein molecule with respect to the calcium sites, to avoid direct interference with these sites, as confirmed by 113Cd NMR. The effect of the disulfide bond on calcium binding was assessed by titrations in the presence of a chromophoric chelator. A small but significant effect on the cooperativity was found, as well as a very modest reduction in calcium affinity. The disulfide bond increases Tm, the transition midpoint of thermal denaturation, of calcium free calbindin D9k from 85 to 95 degrees C and Cm, the urea concentration of half denaturation, from 5.3 to 8.0 M. Calbindins with one covalent bond linking the two EF-hand subdomains are equally stable regardless if the covalent link is the 43-44 peptide bond or the disulfide bond. Kinetic remixing experiments show that separated CNBr fragments of (L39C + P43M + I73C), each comprising one EF-hand, form disulfide linked homodimers. Each homodimer binds two calcium ions with positive co-operativity, and an average affinity of 10(6) M-1. Disulfide linkage dramatically increases the stability of each homodimer. For the homodimer of the C-terminal fragment Tm increases from 59 +/- 2 without covalent linkage to 91 +/- 2 degrees C with disulfide, and Cm from approximately 1.5 to 7.5 M. The overall topology of this homodimer is derived from 1H NMR assignments and a few key NOEs.

Plasma amyloid precursor protein is decreased in Alzheimer's disease.

Alzheimer's disease is characterized by amyloid deposits whose major protein component is beta A4. beta A4 is a product of the amyloid precursor protein (APP). APP was assayed in partially purified plasma samples from 16 sporadic Alzheimer's disease patients, 12 age-matched controls, 15 Down's syndrome individuals aged 19-36 years and 8 young to middle-aged controls (22-51 years). 14 of the 16 Alzheimer's disease patients had decreased plasma APP when compared with age-matched controls. 14 of the 15 Down's syndrome individuals had similar levels of APP when compared with age-matched and elderly non-demented controls by immunoblotting, whereas one had levels of APP less than controls. Taken together with results from a previous report (Lancet 1992; 340: 453-454), the decreased plasma APP levels mirror the changes observed with cerebrospinal fluid APP levels in Alzheimer's disease.