Switching from zidovudine/lamivudine to tenofovir/emtricitabine improves fat distribution as measured by fat mass ratio

OBJECTIVES

Fat mass ratio (FMR) has been suggested as an objective indicator of abnormal body fat distribution in HIV infection. Although it could provide more comprehensive information on body fat changes than limb fat mass, FMR has scarcely been used in clinical trials examining body fat distribution in HIV-infected patients.

METHODS

A subanalysis of a controlled, randomized clinical trial in virologically suppressed HIV-1-infected men switching from zidovudine (ZDV)/lamivudine (3TC) to emtricitabine (FTC)/tenofovir (TDF) versus continuing on ZDV/3TC was carried out. FMR was assessed by dual X-ray absorptiometry (DEXA) for a period of 72 weeks. Lipoatrophy was defined as FMR ≥ 1.5. Multivariate linear regression models for the change in FMR from baseline were fitted.

RESULTS

Sixty-five men were randomized and treated (28 in the FTC/TDF arm and 37 in the ZDV/3TC arm), and 57 completed the study (25 and 32 in each arm, respectively). In the FTC/TDF arm, adjusted mean FMR decreased by 0.52 at week 72 (P = 0.014), and in the ZDV/3TC arm it increased by 0.13 (P = 0.491; P between arms = 0.023). Among subjects with lipoatrophy (baseline FMR ≥ 1.5), adjusted FMR decreased by 0.76 (P = 0.003) in the FTC/TDF arm and increased by 0.21 (P = 0.411; P between arms = 0.009) in the ZDV/3TC arm. Baseline FMR and treatment group were significant predictors (P < 0.05) of post-baseline changes in FMR.

CONCLUSIONS

Switching from ZDV/3TC to FTC/TDF led to an improvement in FMR, compared with progressive worsening of FMR in subjects receiving ZDV/3TC, showing that fat mass not only increased but was also distributed in a healthier way after the switch.

Prevalence of R5 and X4 HIV variants in antiretroviral treatment experienced patients with virologic failure

BACKGROUND

Antiretroviral therapy (ART) inhibits virus replication. Nevertheless, ART has the disadvantage of generate selective resistance and adverse events. Coreceptor antagonists are a family of antiretroviral drugs that are used with the prior knowledge of patients HIV tropism.

OBJECTIVES

The purpose of this work was to estimate the prevalence of R5 and X4 variants among Chilean patients under antiretroviral therapy and virological failure and investigate variables such as plasma viral load (pVL) and CD4 cell count in the population studied.

STUDY DESIGN

HIV RNA or proviral DNA was extracted from 454 consecutives patients and tropism testing was performed using a genotypic method performed with Geno2pheno setting a cutoff value for FPR 5.75%.

RESULTS

Among 454 individuals analyzed, 299 (66%) harbouring exclusively R5 variants. They not displayed a better clinical profile than individuals harbouring X4 strains (22%). For R5 patients the median of pVL and CD4 cell count were 268,000copies/mL, and 223cells/μL respectively. For X4 samples the values were 368,000copies/mL and 214cells/μL [P>0.05]). Only, 53 patients (12%) could not be analyzed and were categorized as non-reportable.

CONCLUSIONS

The genotypic method confirmed that R5 strains were more prevalent despite the fact that patients were treatment-experienced for several years. The genotypic strategy proved to be a faster and cost-effective option as compared to phenotypic assays. According to our results, two of every three patients under antiretroviral therapy and with virologic failure harbour R5 strains, and may be candidates for use of a CCR5 antagonist.

Microbial examination of anaerobic sludge adaptation to animal slurry

The objective of this study was to evaluate changes in the microbial population of anaerobic sludge digesters during the adaptation to pig slurry (PS) using quantitative real-time polymerase chain reaction (qPCR) and qualitative scanning electron microscopy (SEM). Additionally, the relationship between microbial parameters and sludge physicochemical composition and methane yield was examined. Results showed that the addition of PS to an unadapted thermophilic anaerobic digester caused an increase in volatile fatty acids (VFA) concentration, a decrease in removal efficiency and CH4 yield. Additionally, increases in total bacteria and total archaea were observed using qPCR. Scanning electron micrographs provided a general overview of the sludge's cell morphology, morphological diversity and degree of organic matter degradation. A change in microbial morphotypes from homogeneous cell morphologies to a higher morphological diversity, similar to that observed in PS, was observed with the addition of PS by SEM. Therefore, the combination of qPCR and SEM allowed expanding the knowledge about the microbial adaptation to animal slurry in thermophilic anaerobic digesters.

The use of agricultural substrates to improve methane yield in anaerobic co-digestion with pig slurry: effect of substrate type and inclusion level

Anaerobic co-digestion of pig slurry with four agricultural substrates (tomato, pepper, persimmon and peach) was investigated. Each agricultural substrate was tested in co-digestion with pig slurry at four inclusion levels: 0%, 15%, 30% and 50%. Inclusion levels consisted in the replacement of the volatile solids (VS) from the pig slurry with the VS from the agricultural substrate. The effect of substrate type and inclusion level on the biochemical methane potential (BMP) was evaluated in a batch assay performed at 35 °C for 100 days. Agricultural substrate's chemical composition was also analyzed and related with BMP. Additionally, Bacteria and Archaea domains together with the four main methanogenic archaeal orders were quantified using quantitative real-time TaqMan polymerase chain reaction (qPCR) at the end of the experiment to determine the influence of agricultural substrate on sludge's microbial composition. Results showed that vegetable substrates (pepper and tomato) had higher lipid and protein content and lower carbohydrates than fruit substrates (persimmon and peach). Among substrates, vegetable substrates showed higher BMP than fruit substrates. Higher BMP values were obtained with increasing addition of agricultural substrate. The replacement of 50% of VS from pig slurry by tomato and pepper increased BMP in 41% and 44%, respectively compared with pig slurry only. Lower increments in BMP were achieved with lower inclusion levels. Results from qPCR showed that total bacteria and total archaea gene concentrations were similar in all combinations tested. Methanomicrobiales gene concentrations dominated over the rest of individual archaeal orders.

HIV-1 tropism: a comparison between RNA and proviral DNA in routine clinical samples from Chilean patients

Background

HIV in Chile has a notification rate of 0.01%. Coreceptor antagonists are a family of antiretroviral drugs that are used with the prior knowledge of patients HIV-1 tropism. Viral RNA-based tropism detection requires a plasma viral load ≥1000 copies/mL, while proviral DNA-based detection can be performed regardless of plasma viral load. This test is useful in patients with low or undetectable viral loads and would benefit with a proper therapy. The aim of this study was to determine the correlation between HIV RNA and proviral genotypic DNA tropism tests.

Findings

Forty three Chilean patients were examined using population-based V3 sequencing, and a geno2pheno false-positive rate (FPR) cutoff values of 5, 5.75, 10 and 20%. With cutoff 5.75% a concordance of 88.4% in tropism prediction was found after a simultaneous comparison between HIV tropism assessment by RNA and DNA. In total, five discrepancies (11.6%) were found, 3 patients were RNA-R5/DNA-X4 and two were RNA-X4/DNA-R5. Proviral DNA enabled the prediction of tropism in patients with a low or undetectable viral load. For cutoff 5 and 5.75% genotypic testing using proviral DNA showed a similar sensitivity for X4 as RNA. We found that the highest sensitivity for detecting the X4 strain occurred with proviral DNA and cutoff of 10 and 20%. Viral loads were higher among X4 strain carriers than among R5 strain carriers (p < 0.05).

Conclusions

A high degree of concordance was found between tropism testing with RNA and testing with proviral DNA. Our results suggest that proviral DNA-based genotypic tropism testing is a useful option for patients with low or undetectable viral load who require a different therapy.

Electric-field-induced phase transitions in bent-core mesogens determined by x-ray diffraction

The changes in the x-ray diffraction diagram induced by an electric field have been studied in four bent-core liquid crystals. Two of the compounds present columnar B1 phases and the other two show dark conglomerate (DC) structures. In the B1 materials the electric field gives rise to switchable phases whose diffraction pattern is that of the smectic C polar (SmCP) phase. In the DC structures the positions of the Bragg reflections remain essentially unaltered, but in one of the compounds the peaks become narrower under field, indicating that the correlation length of the smectic order increases. A slight enhancement of the smectic spacing is found in the DC phases upon field application.

[Quality improvement of the filling medication trolleys process, for an unit-dose drug distribution system]

OBJECTIVE

To assess the quality of filling medication trolleys process for an unit-dose drug distribution system, after the implantation of a protocol.

METHOD

Five criteria were defined: four were related to the medication given to the patient, and one criterion was related to the patient's identification. At the same time, it was designed a standardized protocol of filling medication trolleys process and it was evaluated the degree of compliance with the criteria on all the hospitalized patients medication drawers in two clinical units. The fulfilment of the criteria was measured both before and after the implantation of the protocol, for fourteen and seven days respectively.

RESULTS

In the first evaluation the number of errors was 0.84/medication drawer. After the implantation of the protocol, the total number of errors after correction for sample size decreased at 0.22/medication drawer. The degree of compliance improved for all the criteria, and differences were statistically significant for the criteria with most errors.

CONCLUSIONS

The implantation of a protocol significantly improved two of the five quality criteria studied in the filling medication trolleys process. The patient's identification has been revealed as a fundamental aspect of intervention in the dispensation quality.

Recombinant production of serine hydroxymethyl transferase from Streptococcus thermophilus and its preliminary evaluation as a biocatalyst

The glyA gene encoding a serine hydroxymethyl transferase (SHMT) with threonine aldolase activity was isolated from Streptococcus thermophilus YKA-184 chromosomal DNA. This aldolase is a pyridoxal 5'-phosphate-dependent enzyme that stereospecifically catalyzes the interconversion of L-threonine to glycine and acetaldehyde. The enzyme was overexpressed in Escherichia coli M15 as a recombinant protein of 45 kDa with a His6-tag at its N-terminus. The recombinant enzyme was purified to homogeneity by a single chromatographic step using Ni-nitrilotriacetic acid affinity, obtaining a high activity-recovery yield (83%). Lyophilized and precipitated enzymes were stable at least for 10 weeks when stored at -20 degrees C and 4 degrees C. It was observed that the Km for L-allo-threonine was 38-fold higher than that for L-threonine, suggesting this enzyme can be classified as a specific L-allo-threonine aldolase. The optimum pH range of threonine aldolase activity for the recombinant SHMT was pH 6-7. When tested for aldol addition reactions with non-natural aldehydes, such as benzyloxyacetaldehyde and (R)-N-Cbz-alaninal, two possible beta-hydroxy-alpha-amino acid diastereoisomers were produced, but with moderate stereospecificity. The enzyme showed potential as a biocatalyst for the stereoselective synthesis of beta-hydroxy-alpha-amino acids.

MR-myelography as an adjunct to the MR examination of the degenerative spine

Our objective was to analyse the usefulness of single-slice MR-myelography images as a complementary test to conventional MR of the spine in patients with clinically suspected degenerative spine disease. A prospective analysis of 1022 consecutive patients studied with conventional MR and MR-myelography (four acquisitions: one coronal plane, one sagittal plane, and two oblique lateral, right and left planes) examinations was performed. Conventional MR and MR-myelography studies were classified as positive when morphological or structural alterations were noted. Positive MR-myelography information was also categorized as relevant if findings were considered important and radiologically significative to the final diagnosis (either by increasing the radiologists confidence in the diagnosis or because the findings were not observed in the conventional study). Other positive findings were considered non- relevant. There were 62% cases considered positive in the MR-myelography examination. Of them, 3% revealed no alterations on the conventional MR examination. Of the negative MR-myelography studies, 75% had a positive conventional MR examination. Considered as diagnostic techniques, their Kappa concordance was poor. However, MR-myelography complemented the information obtained with the conventional MR examination of the spine, this information being relevant to the final MR diagnosis in 22% of the total number of cases. The contribution of MR-myelography was not different in the three spinal levels. In conclusion, MR-myelography complements the information obtained with conventional MR in a large number of cases.

Dengue-1 virus isolation during first dengue fever outbreak on Easter Island, Chile

Dengue virus was detected for the first time in Chile, in an outbreak of dengue fever on Easter Island. The virus was isolated in tissue culture and characterized by reverse transcription–polymerase chain reaction as being dengue type 1.

Immunoresponse of Coho salmon immunized with a gene expression library from Piscirickettsia salmonis

We have used the expression library immunization technology to study the protection of Coho salmon Oncorhynchus kisutch to the infection with Piscirickettsia salmonis. Purified DNA from this bacterium was sonicated and the fragments were cloned in the expression vector pCMV-Bios. Two libraries were obtained containing 22,000 and 28,000 colonies and corresponding to approximately 8 and 10 times the genome of the pathogen, respectively. On average, the size of the inserts ranged between 300 and 1,000 bp. The plasmid DNA isolated from one of these libraries was purified and 20 micrograms were injected intramuscularly into 60 fish followed by a second dose of 10 micrograms applied 40 days later. As control, fish were injected with the same amount of DNA of the vector pCMV-Bios without insert. The titer of IgM anti-P. salmonis of vaccinated fish, evaluated 60 days post-injection, was significantly higher than that of the control group injected with the vector alone. Moreover, this response was specific against P. salmonis antigens, since no cross reaction was detected with Renibacterium salmoninarum and Yersinia ruckeri. The vaccinated and control fish were challenged 60 days after the second dose of DNA with 2.5 x 10(7) P. salmonis corresponding to 7.5 times the LD50. At 30 days post-challenge, 100% mortality was obtained with the control fish while 20% of the vaccinated animals survived. All surviving fish exhibited a lower bacterial load in the kidney than control fish. The expression library was also tested in Balb/c mice and it was found that the humoral immune response was specific to P. salmonis and it was dependent on the amount of DNA injected.

Production of native and recombinant lipases by Candida rugosa: a review

The yeast Candida rugosa produces multiple lipase isoenzymes sharing high sequence homology but with some differences in their catalytic properties. The regulation of C. rugosa lipase (CRL) synthesis and secretion in C. rugosa obeys a complex pattern. Fermentation processes for both wild-type and mutant C. rugosa strains are available for lipase production. Native CRL preparations have been extensively used for biotransformations. However, their inherent mixture of isoforms with variable profiles complicates interpretation and brings into question the reproducibility achieved between preparations. Although heterologous CRLs gene expression had been hampered owing to a nonuniversal codon usage, recent advances have made heterologous CRLs available. This will expand and improve the industrial utility of CRLs even further. The purpose of this review is to provide a summary of the recent advances on the production of native and recombinant lipases by C. rugosa.

Tolerability and efficacy of almotriptan in the long-term treatment of migraine

BACKGROUND

Almotriptan is a highly specific 5-HT(1B/1D) receptor agonist, which acts selectively on blood vessels of the brain. Short-term studies have demonstrated that almotriptan provides rapid, effective and reliable relief of migraine attacks, while offering excellent tolerability.

PURPOSE

To assess the long-term tolerability and efficacy of oral almotriptan 12.5 mg administered for every migraine attack over a 1-year period.

METHODS

A total of 762 patients treated 13,751 attacks (1-97 per patient); 61.5% of attacks were treated with one 12.5-mg dose, while for 38.5% of attacks, patients took a second dose within 24 h.

RESULTS

Three hundred and ninety-one patients (51.3%) experienced a total of 1,617 adverse events (AEs). The majority (88.6%) of AEs were of mild-to-moderate intensity, and only 28.8% of AEs were considered to be related to the study drug. Only 2 patients experienced serious AEs possibly related to almotriptan, syncope and chest pain; both recovered without any sequelae. Patients reported at least 1 AE in 11% of attacks treated. The incidence of AEs decreased during the study. Only 6 (0.8%) study withdrawals were due to AEs considered to be related to almotriptan. Tolerability was not compromised in patients taking 2 doses of almotriptan or in those using migraine prophylactics. Patient age or sex did not influence the incidence of AEs. There was no evidence of tachyphylaxis in those patients completing the study. Pain relief at 2 h after the initial dose was achieved in 84.2% of moderate/severe attacks. Patients were pain free at 2 h after dose in 58.2% of all attacks. Older patients (> 40 years) tended to respond better than younger ones (< 40 years). Efficacy was not modified by use of migraine prophylactics or hormonal contraceptives. Efficacy measurements were consistent on treating repeated moderate/severe migraine attacks.

CONCLUSION

This large, open study indicates that the new, specific 5-HT(1B/1D) agonist almotriptan, at a dose of 12.5 mg, is a well tolerated and effective treatment for migraine pain when used over a period of up to 1 year.

Optimization of the high-level production of Rhizopus oryzae lipase in Pichia pastoris

The lipases of the Rhizopus species family are important and versatile enzymes that are mainly used in fat and oil modification due to their strong 1,3-regiospecificity. Inexpensive synthetic medium was used for the production of Rhizopus oryzae lipase in the methylotrophic yeast Pichia pastoris. Methanol accumulation inside the bioreactor has previously been shown to negatively influence the production level. Three different methanol fed-batch strategies for maintaining the methanol concentration within optimal limits have been assayed in high-density cultures. One methanol feeding strategy, which is based on the monitoring of the methanol concentration by gas chromatography, resulted in a 2.5-fold higher productivity compared to an initial cultivation, where the feeding rate was adjusted according to the dissolved oxygen concentration (DO) in the supernatant. Finally, productivity could be further increased by introducing a transition phase that involved the simultaneous feeding of glycerol and methanol followed by a single methanol feed. This optimized strategy resulted in the highest productivity (12888 U l(-1) h(-1)), which is 13.6-fold higher than the DO-based strategy.

Long-term efficacy and safety of oral almotriptan: interim analysis of a 1-year open study

OBJECTIVE

To assess the long-term tolerability and safety of a single, oral 12.5-mg dose of almotriptan and its efficacy in alleviating pain associated with consecutive migraine episodes occurring during a 12-month period.

BACKGROUND

While sumatriptan appears to be effective for treatment of migraine, the drug has several properties that limit its use. Almotriptan, a new selective 5-HT1B/1D agonist, may be better tolerated over the long term.

METHODS

This 1-year study was conducted on 806 adults between the ages of 18 and 65 years suffering from migraine, either with or without aura. The patients met the criteria for study as outlined by the International Headache Society and were instructed on drug use. Oral almotriptan 12.5 mg was used to treat the attack of any pain severity and a second dose was permitted in case of relapse of pain during the first 24 hours. Rescue medication was provided. Efficacy and tolerability were assessed by a combination of patient reporting and clinical visit evaluations.

RESULTS

Overall, almotriptan was well tolerated. At 2 hours, 81% of attacks were relieved; 56% of the subjects were entirely free of pain. These efficacy data are similar for the first as well as the last attack studied. At analysis, 534 patients had treated their migraines for at least 6 months. About half of all patients experienced at least one adverse event, with 87% of the events being mild or moderate in nature. The most frequent adverse events were back pain (7.23% of patients), bronchitis (5.76%), and influenzalike symptoms (5.62%). Seventy-one percent of the adverse events were not related to almotriptan use.

CONCLUSIONS

Almotriptan at an oral dose of 12.5 mg is safe antimigraine treatment. The safety profile results are similar to those obtained in other controlled triptan clinical studies. Almotriptan is efficacious in moderate-to-severe migraine pain and can be used repeatedly in recurrent episodes. The long-term safety data will be reanalyzed when full data become available.