Erythrocyte deformability in naïve HIV-infected patients

HIV-infected patients are at increased cardiovascular risk. Although several studies have analyzed the hemorheological profile in these patients, studies dealing with erythrocyte deformability are scarce. Moreover, studies have been performed in HIV patients on antiretroviral treatment which may influence this rheological parameter. We analyzed erythrocyte deformability (Elongation Index) at 12, 30 and 60 Pa by means of the Rheodyn SSD in 34 naïve HIV-infected patients (22 males and 12 females) and 34 HIV negative control subjects (24 males and 10 females). Erythrocyte indices (MCV, MCH, MCHC), reticulocytes, plasma lipids, iron, folic acid, vitamin B12 and hepatic enzymes were also determined. When compared with controls, naïve HIV-infected patients showed lower total cholesterol, iron, bilirubin and folic acid (p = 0.009, p = 0.003, p = 0.004, p = 0.004, respectively) and higher triglycerides (TG), aspartate aminotransferase (AST) and gamma glutamyl transferase (γGt) levels (p = 0.017, p = 0.042, p = 0.004, respectively). In the multivariate regression analysis, MCV, γGt and triglycerides were independent predictors of EI60. Neither erythrocyte indices nor reticulocyte count showed differences (p > 0.05). No differences in the Elongation Index at any of the shear stresses tested (12, 30, 60 Pa) were found (p > 0.05). The results of the present study indicate that naïve HIV-infected patients not on antiretroviral treatment do not present decreased erythrocyte deformability when compared with HIV negative control subjects.

Bacterial stimulation of the TLR-MyD88 pathway modulates the homeostatic expression of ileal Paneth cell α-defensins

Paneth cell α-defensins are antimicrobial peptides involved in the control of the intestinal microbiota and immunological homeostasis. In mice, they are encoded by multiple, highly homologous genes (Defa). The transcriptional activity of ileal Defa genes was studied in response to pharmacological and genetic perturbations of the intestinal environment of C57BL/6 mice. Defa gene transcription was sensitive to oral antibiotic administration suggesting that commensal microbes regulate Defa expression. Ileal microbiota analysis showed that decreased transcription of Defa genes correlated with depletion of Lactobacillus. Defa expression was partially restored in vivo by lactobacillus administration to antibiotic-treated mice. Defa transcripts were less abundant in ex vivo, microbiota-free intestinal explants but recovered after explant exposure to UV-killed bacteria, Toll-like receptor (TLR)-2 or TLR4 agonists. Genetic deficiency of several TLRs or MyD88 led to dramatic drops in Defa transcription in vivo. These results show that Paneth cell Defa genes are regulated by commensal bacteria through TLR-MyD88 signaling and provide a further understanding of the dysregulation of intestinal homeostasis that occurs as a result of imbalances in the populations of commensal bacteria.

Daily or monthly ibandronate prevents or restores deteriorations of bone mass, architecture, biomechanical properties and markers of bone turnover in androgen-deficient aged rats

AIM

The aim of this study was to investigate the effects of the bisphosphonate ibandronate (IBN) in a male osteoporosis animal model.

METHODS

Two studies were performed in 9-month-old orchidectomised (ORX) or sham-operated rats. In prevention study, subcutaneous IBN was administered daily (1 μg/kg) or monthly (28 μg/kg every 28 days) starting on day of surgery for 5 months. In treatment study, the same treatment started 6 months after ORX. After sacrifice, bone analyses by dual-energy X-ray absorptiometry, 3-dimensional micro-computed tomography, and 3-point bending were performed in femora or vertebrae. Serum tartrate-resistant acid phosphatase 5b (TRAP-5b) and aminoterminal propeptide of collagen I (PINP) were analysed for resorption and osteocalcin (BGP) for bone formation.

RESULTS

In both studies, ORX resulted in significant femoral and vertebral bone loss and microarchitectural deterioration after 5 months of ORX, and became more pronounced after 11 months. Biomechanical strength was also decreased. Serum levels for TRAP-5b and BGP increased while PINP levels were reduced or unchanged. Both daily and monthly IBN prevented or even restored ORX-induced changes in both studies, with the intermittent regimen showing a improvement in efficacy with respect to many of the biomechanical parameters.

Response to HAART in treatment-naive HIV-infected patients with a prior diagnosis of tuberculosis or other opportunistic infections

We aimed to evaluate immunological, virological and clinical response to HAART, as well as all-cause mortality, in treatment-naive patients with a diagnosis of tuberculosis (TB) in the prior 6 months, compared to subjects with another AIDS-defining illness (ADI) or event-free individuals in an open, prospective and multicenter hospital-based cohort of HIV-infected naive adults (2004-2008). All cause mortality rates were calculated by Cox regression models. Among 4407 patients, 2400 (54.5%) started HAART: 110 (4.6%) had had previous TB and 414 (17.3%) another ADI. Median time from TB diagnosis to inititation of HAART was 53 days (IQR: 25.75-83.25), and for other ADI was 22 days (IQR: 8-42). Overall, 151 (6.3%) patients developed a new ADI during follow-up; 63% reached virological suppression and 69.4% had increases of ≥50 CD4+/µl, at 6 months. No statistically significant differences were found according to a previous history of TB or another ADI. Overall, 85 subjects died in 4031 person-years of follow-up with a mortality rate of 2.1 (95%CI: 1.7-2.6). When compared to subjects who started HAART in the absence of a previous ADI (HR 1), a prior diagnosis of an ADI other than TB was significantly associated with an increased risk of death. (HR 1.6; 95%CI: 1.1-2.3), but not a diagnosis of TB (HR 1.15; 95%CI: 0.5-2.5). In conclusion, a previous diagnosis of TB or another ADI before HAART did not compromise short-term virological and immunological response to treatment. A prior diagnosis of an ADI different to TB significantly increased all cause mortality.

Colonic microbiota alters host susceptibility to infectious colitis by modulating inflammation, redox status, and ion transporter gene expression

Individuals vary in their resistance to enteric infections. The role of the intestinal microbiota in altering susceptibility to enteric infection is relatively unknown. Previous studies have identified that C3H/HeOuJ mice suffer 100% mortality during Citrobacter rodentium-induced colitis, whereas C57BL/6 mice recover from infection. The basis for their differences in susceptibility is unclear and has been mainly attributed to differences in host genetics. This study investigated the role of the intestinal microbiota in altering susceptibility to C. rodentium-induced colitis. When the feces of C57BL/6 mice were gavaged into antibiotic treated C3H/HeOuJ mice, the C57BL/6 microflora led to a complete reversal in mortality patterns where 100% of the C3H/HeOuJ mice survived infection. This protection corresponded with reduced colonic pathology and less systemic pathogen load and was associated with increased inflammatory and redox responses with reduced epithelial cell death. C3H/HeOuJ mice are normally susceptible to infection-induced dehydration due to defective expression of colonic ion transporters such as Dra, CA IV, and CA I; expression of these genes was normalized when C3H/HeOuJ mice were colonized with the C57BL/6 microflora. Together, these data reveal that the colonic microbiota play a critical role in protecting against intestinal infection by inducing proinflammatory and prooxidant responses that control pathogen load as well as ion transporter gene expression previously shown to prevent fatal dehydration. Protection of mice from lethal colitis was associated with higher levels of bacteria from Bacteroidetes. This study reveals that the microbiota is sufficient to overcome inherent genetic susceptibility patterns in C3H/HeOuJ mice that cause mortality during C. rodentium infection.

The effectiveness of intermittent rat parathyroid hormone (1-34) treatment on low bone mass due to oestrogen or androgen depletion in skeletally mature rats

Rat parathyroid hormone (PTH) 1-34 (4 microg/kg/day) was applied for 2.5 months to 9 month-old rats immediately after ovariectomy or orchidectomy or to 15 month-old rats with low bone mass which had been castrated 6 months before in order to know the effects on serum biochemistry parameters, lumbar and femoral bone mineral density, histology, cancellous and cortical bone histomorphometry, mineralisation content profile in cortical bone by backscattered-electron microscopy, and femoral torsion biomechanical testing. In ovariectomised rats, preventive PTH treatment avoided cancellous bone loss in tibial metaphysis and partially in lumbar vertebra, while in cortical bone, PTH increased endosteal resorption and periosteal formation. In intervention study, PTH did not restore cancellous bone but a strong endosteal and periosteal new bone formation was detected. In orchidectomised rats, PTH, in preventive study, avoided cancellous bone loss in metaphysis and lumbar vertebra, and a mild new bone formation in cortical bone was found. In intervention study, PTH maintained baseline cancellous bone mass, but in cortical bone a strong endosteal and periosteal new bone formation was detected. The PTH-induced new bone formation was confirmed by histology and by mineral content profiles. After castration, biomechanical properties were affected in females but not in male rats and PTH reverted this effect.

Effectiveness and safety of colistin for the treatment of multidrug-resistant Pseudomonas aeruginosa infections

PURPOSE

To describe the clinical and microbiological outcomes of patients infected with multidrug-resistant Pseudomonas aeruginosa (MDRP) treated with colistin (colistimethate sodium) and the adverse events observed with this treatment.

METHODS

Retrospective study of MDRP infections treated with colistin from 1997 to 2006.

RESULTS

121 episodes were identified. The median daily intravenous dose was 240 mg/day; 28.9% of patients received intravenous and nebulized colistin. Clinical outcome was favorable in ten cases of bacteremia (62.5%, n = 16), 43 cases of bronchial infection (72.9%, n = 59), 13 cases of pneumonia (65%, n = 20), 11 cases of urinary infection (84.6%, n = 13), eight cases of skin and soft tissues (72.7%, n = 11), and in the one case of arthritis and one case of otitis. Eradication was achieved in 31 (34.8%) of the 89 patients with available bacteriologic data. Factors associated with bacteriological failure were smoking, chronic obstructive pulmonary disease (COPD), and previous infection with P. aeruginosa. Nephrotoxicity occurred in ten cases (8.3%), with the associated factors being previous chronic renal insufficiency, diabetes mellitus, and aminoglycoside use. Crude mortality was 16.5%, and related MDRP was 12.4%, and was higher in patients with pneumonia or bacteremia (36.1%) than in other types of infections (8.2%).

CONCLUSIONS

Colistin is a safe option for the treatment of MDRP infections, with acceptable clinical outcomes. However, bacteriological eradication is difficult to achieve, especially in COPD patients.

Impact of different patterns of nonadherence on the outcome of highly active antiretroviral therapy in patients with long-term follow-up

OBJECTIVES

The aim of the study was to evaluate the impact of different patterns of nonadherence on treatment outcomes in patients with long-term follow-up.

METHODS

This cohort study included patients who began highly active antiretroviral therapy during 1996-1999, with the last follow-up in 2007. Adherence was evaluated every 2 months by monitoring of pharmacy refills and by using self-reports. Patients were considered nonadherent at a specific visit when less than 90% of the prescribed drugs had been taken. Adherence was categorized as follows. (A) Continuous adherence: a patient had to be adherent in all of the evaluations throughout the period of follow-up. (B) Treatment interruption: drugs were not taken for more than 3 days, for any reason. Treatment failure was defined as viral load >500 HIV-1 RNA copies/mL or death. Cox proportional risk models were used to calculate adjusted relative hazards (ARHs) of treatment failure.

RESULTS

A total of 540 patients were included in the study, with a median follow-up of 8.3 years. Only 32.78% of patients achieved and maintained continuous adherence, and 42.78% of patients had treatment interruptions. Noncontinuous adherence [ARH 1.48; 95% confidence interval (CI) 1.02-2.14] and treatment interruptions (ARH 1.39; 95% CI 1.04-1.85) were associated with treatment failure for the overall cohort; however, for patients with more than 3 years of follow-up, only treatment interruptions were independently associated with treatment failure.

CONCLUSIONS

Only one-third of patients managed to achieve continuous adherence, and almost half of the patients had treatment interruptions, which have a particularly marked effect on treatment outcomes over the long term.

Mortality of COPD patients infected with multi-resistant Pseudomonas aeruginosa: a case and control study

BACKGROUND

The incidence of infections caused by multiresistant Pseudomonas aeruginosa (MDRP) is increasing, especially in critically ill patients. The relevance of MDRP in the prognosis of chronic obstructive pulmonary disease (COPD) acute exacerbation in patients admitted to the hospital's general ward is not well known.

PATIENTS AND METHODS

Case and control study. Cases were patients admitted for COPD acute exacerbation in which a MDRP was isolated from spontaneous sputum. MDRP was defined as the absence of susceptibility to three or more antibiotic families (betalactams, quinolones, carbapenems and aminoglycosides). Patients currently or previously admitted to the intensive care unit (ICU), who had a recent surgery, neoplasia or immunosuppressive treatment were excluded from the study. Patients from the control group were admitted for COPD acute exacerbation and matched 1:1 with each case-patient in terms of age, sex, date of admission and degree of airway obstruction. Pseudomonas aeruginosa susceptible to all antimicrobials or other microorganisms was isolated from sputum.

RESULTS

During the study period (2000-2005), 50 case-patients and 50 controls were included. Crude mortality at 2 years was 60% for the case-patients and 28% for the control group. In the logistic regression analysis adjusted for age, FEV(1) and number of previous hospital admissions, MDRP infection was associated to an increased mortality in comparison to patients without MDRP (OR = 6.2; IC 95%: 1.7-22.1; p < 0.01).

CONCLUSIONS

In COPD patients admitted to the general ward, acute exacerbation with MDRP in sputum was associated with higher mortality.

[Prognostic value of the ultrasound and diuretic renogram in the evolution of ureteropelvic junction obstruction]

INTRODUCTION

The congenital obstruction of the pieloureteral junction (UPJ) is the most frequent cause of hydronephrosis in children. Sometimes, establishing the convenience of a surgical procedure is difficult, mainly if we consider the literature published on the spontaneous resolution of the slight, moderate and even severe hydronephrosis in newborns.

OBJECTIVE

To determine the prognostic value of ultrasound in the evolution of the unilateral hydronephrosis, by assesing the size of the contralateral kidney. To verify if the "supranormal" renal function (SRF) is real or an artefact.

PATIENTS AND METHODS

We have performed a descriptive observational study over a 10 years period (1995-2005). The study included all patients with the only diagnosis of obstructive unilateral hydronephrosis that underwent pieloplasty, and were controlled for 1 year period after the surgical treatment.

RESULTS

Of the 66 patients in the study, 42 were boys (63.6%) and 24 girls (36.4%). After the first diuretic renogram (DR), in 57 of the patients (86.4%) the clearance half-time (T1/2) was over 20 minutes, in 6 cases (9.1%) it was 10-20 minutes and only in 3 cases it was shorter than 10 minutes. A similar differential renal function (FRD) was observed in the moderate and severe hydronephrosis. Supranormal function (FRD > 52%) was detected on DR in 11 patients, predominating in left hidronefrosis, and in more than 50% of the cases this value it did not agree with the renal function measured by dimercapto-succinic acid (DMSA), Pearson's correlation coefficient: 0.19. These kidneys experienced a greater reduction of the postoperative renal function.

CONCLUSIONS

In the unilateral obstructive hydronephrosis, the healthy contralateral kidney experiences hypertrophy detectable by ultrasound, but these ecographic diameters are within the band of individual confidence of the healthy children of reference. The supranormal function exists, but in most cases it is an artefact.

[Sex influence in lipodystrophy of HIV-infected patients and its association with cardiovascular risk factors]

OBJECTIVE

To evaluate the influence of sex in human immunodeficiency virus (HIV)-infected patients with lipodystrophy and its association with cardiovascular risk factors.

PATIENTS AND METHOD

A cross-sectional study was conducted in HIV-infected patients aged 20 or over managed at the outpatient Infectious Disease Unit in 2003. Clinical and epidemiological characteristics of HIV infection, lipodystrophy and cardiovascular risk factors were evaluated.

RESULTS

Of the 760 patients included in the study, women comprised 28%. Men with lipodystrophy had a higher prevalence of hypertension, hypercholesterolemia, hypoalphalipoproteinemia and hypertriglyceridemia than those without lipodystrophy. Women with lipodystrophy had a higher prevalence of central obesity and hypertriglyceridemia compared with those without lipodystrophy (22.8 vs. 11.2%, p = 0.000; 20.6 vs. 9.3%, p = 0.001; 39.7 vs. 30%, p = 0.03 y 56.6 vs. 40.9%, p = 0.0001, respectively). The lipoatrophy pattern was predominant in men (24.9 vs. 12.6%, p = 0.0001) and lipoaccumulation forms in women (12.3 vs. 22.6%, p = 0.0001). Furthermore, women were younger, had a higher prevalence of smoking, family history of premature coronary heart disease and central obesity, and a lower prevalence of hypertension and hypoalphalipoproteinemia than men with lipodystrophy (42.1 +/- 8 years vs. 44.8 +/- 9.9 years, p = 0.03; 77.5 vs. 64%, p = 0.04; 22.5 vs. 9%, p = 0.003; 31 vs. 8.5%, p = 0.0001; 9.9 vs. 22.8%, p = 0.01; 25.4 vs. 39.7%, p = 0.03).

CONCLUSIONS

This study demonstrated that the influence of sex in lipodystrophy in HIV-infected patients affects not only the lipodystrophy pattern, but also the cardiovascular risk profile.

Cloning and characterization ofbgn16·3, coding for a β-1,6-glucanase expressed duringTrichoderma harzianummycoparasitism

AIMS

To clone and characterize the gene coding for BGN16.3, a beta-1,6-glucanase putatively implicated in mycoparasitism by Trichoderma harzianum, a biocontrol agent used against plant pathogenic fungi.

METHODS AND RESULTS

Using degenerate primed PCR and cDNA library screening, we have cloned the cDNA coding BGN16.3. bgn16.3 showed a significant sequence identity (50%) to bgn16.1; however, they both have low identity to the previously cloned bgn16.2, allowing the identification of amino acid sequences putatively involved in the common catalytic activity of the three proteins. bgn16.3 is a single-copy gene and highly homologous sequences are present in all tested Trichoderma species. bgn16.3 expression pattern is analysed by Northern blot, finding that it is expressed during the interaction of T. harzianum CECT 2413 with Botrytis cinerea, supporting the implication of the enzyme in the mycoparasitic process.

CONCLUSIONS

The cloned bgn16.3 completes the knowledge on the beta-1,6-glucanase isozyme system from T. harzianum CECT 2413. A highly homologous gene is present in all analysed Trichoderma strains. bgn16.3 is expressed under few specific conditions, including the mycoparasitic process.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study contributes to the knowledge of beta-1,6-glucanases. It implicates this group of enzymes in the mycoparasitism by some biocontrol agents such as T. harzianum.

The plasma membrane Na+/Ca2+ exchange inhibitor KB-R7943 is also a potent inhibitor of the mitochondrial Ca2+ uniporter

BACKGROUND AND PURPOSE

The thiourea derivative KB-R7943, originally developed as inhibitor of the plasma membrane Na(+)/Ca(2+) exchanger, has been shown to protect against myocardial ischemia-reperfusion injury. We have studied here its effects on mitochondrial Ca(2+) fluxes.

EXPERIMENTAL APPROACH

[Ca(2+)] in cytosol, mitochondria and endoplasmic reticulum (ER), and mitochondrial membrane potential were monitored using both luminescent (targeted aequorins) and fluorescent (fura-2, tetramethylrhodamine ethyl ester) probes in HeLa cells.

KEY RESULTS

KB-R7943 was also a potent inhibitor of the mitochondrial Ca(2+) uniporter (MCU). In permeabilized HeLa cells, KB-R7943 inhibited mitochondrial Ca(2+) uptake with a Ki of 5.5+/-1.3 microM (mean+/-S.D.). In intact cells, 10 microM KB-R7943 reduced by 80% the mitochondrial [Ca(2+)] peak induced by histamine. KB-R7943 did not modify the mitochondrial membrane potential and had no effect on the mitochondrial Na(+)/Ca(2+) exchanger. KB-R7943 inhibited histamine-induced ER-Ca(2+) release in intact cells, but not in cells loaded with a Ca(2+)-chelator to damp cytosolic [Ca(2+)] changes. Therefore, inhibition of ER-Ca(2+)-release by KB-R7943 was probably due to the increased feedback Ca(2+)-inhibition of inositol 1,4,5-trisphosphate receptors after MCU block. This mechanism also explains why KB-R7943 reversibly blocked histamine-induced cytosolic [Ca(2+)] oscillations in the same range of concentrations required to inhibit MCU.

CONCLUSIONS AND IMPLICATIONS

Inhibition of MCU by KB-R7943 may contribute to its cardioprotective activity by preventing mitochondrial Ca(2+)-overload during ischemia-reperfusion. In addition, the effects of KB-R7943 on Ca(2+) homeostasis provide new evidence for the role of mitochondria modulating Ca(2+)-release and regenerative Ca(2+)-oscillations. Search for permeable and selective MCU inhibitors may yield useful pharmacological tools in the future.

Experimental Study and Detailed Modeling of Toluene Degradation in a Low-Pressure Stoichiometric Premixed CH4/O2/N2 Flame

Temperature and mole fraction profiles have been measured in laminar stoichiometric premixed CH4/O2/N2 and CH4/1.5%C6H5CH3/O2/N2 flames at low pressure (0.0519 bar) by using thermocouple, molecular beam/mass spectrometry (MB/MS), and gas chromatography/mass spectrometry (GC/MS) techniques. The present study completes our previous work performed on the thermal degradation of benzene in CH4/O2/N2 operating at similar conditions. Mole fraction profiles of reactants, final products, and reactive and stable intermediate species have been analyzed. The main intermediate aromatic species analyzed in the methane-toluene flame were benzene, phenol, ethylbenzene, benzylalcohol, styrene, and benzaldehyde. These new experimental results have been modeled with our previous model including submechanisms for aromatics (benzene up to p-xylene) and aliphatic (C1 up to C7) oxidation. Good agreement has been observed for the main species analyzed. The main reaction paths governing the degradation of toluene in the methane flame were identified, and it occurs mainly via the formation of benzene (C6H5CH3 + H = C6H6 + CH3) and benzyl radical (C6H5CH3 + H = C6H5CH2 + H2). Due to the abundance of methyl radicals, it was observed that recombination of benzyl and methyl is responsible for main monosubstitute aromatic species analyzed in the methane-toluene flame. The oxidation of these substitute species led to cyclopentadienyl radical as observed in a methane-benzene flame.