Predictive factors for identifying macrolide responder in treating chronic rhinosinusitis.

BACKGROUND: Low-dose macrolides (LDM) are anti-inflammatory agents with antineutrophilic activity, but patient selection for LDM therapy in treating chronic rhinosinusitis (CRS) is controversial. This study aimed to assess factors which predict LDM responders. METHODOLOGY: A prospective cohort study was performed. Patients with CRS received roxithromycin (150 mg) once daily for 12 weeks. Nasal secretions and serology were collected. Nine predictors for LDM response were assessed: nasal secretion IgE, nasal secretion IL-5, serum IgE, serum eosinophils, serum neutrophils, nasal polyps, asthma, allergy, and aspirin hypersensitivity, using receiver-operating curve analysis and multivariable logistic regression. Macrolide responders were those with sino-nasal outcome test-22 improvement, symptoms visual analogue scale decreased to ≤ ≤ ≤5, and no rescue medication. RESULTS: One hundred CRS patients (mean age 47.4 +- 14.1 years, 45% male) were enrolled. Univariable logistic regression showed local total IgE less than 5.21; and serum eosinophils less than 2.2% associated with macrolide response. Multivariate models showed local total IgE maintained an independent association with macrolide response, with an ability to discriminate between responders and non-responders of 63%. Serum total IgE, nasal secretion IL-5, serum neutrophil, nasal polyp, asthma, allergy, and aspirin hypersensitivity showed no association with LDM response. CONCLUSIONS: Low total IgE level in the nasal secretion but not in the serum, predict LDM response.

Chronic occupational exposure to lead leads to significant mucocutaneous changes in lead factory workers.

BACKGROUND: Chronic lead toxicity is a worldwide public health problem. Lead possesses deleterious effects on many organ systems. However, little is known regarding its clinical and biophysical effects on the skin. OBJECTIVE: To investigate mucocutaneous signs and biophysical property changes in skin after chronic lead toxicity. METHODS: One hundred and eighty-seven patients who were car battery workers participated in the study. Complete history and physical examination were performed. Blood was collected for laboratory analyses. Thorough skin examination by dermatologists was carried out in 134 subjects. Additionally, 96 patients with blood lead levels (BLL) >70 µg/dL were further evaluated for skin elasticity, sebum content, transepidermal water loss (TEWL), hydration, pH and pigmentation. An equal number of age-, sex- and skin-type-matched subjects were recruited as controls. RESULTS: The mean BLL of all subjects was 74.15 ± 11.58 µg/dL. The most frequently observed signs were gingival brown pigmentation in 112 (83.6%), gingivitis in 111 (82.8%) and lead line in 66 (49.3%) patients. The lead line was found in subjects with significantly higher BLLs (adjusted mean difference 6.45, 95% CI 2.30-10.60 µg/dL, P = 0.003) and in association with gingivitis (adjusted OR 7.32, 95% CI 2.08-25.74, P = 0.002). Mean BLL of the patients who underwent biophysical assessment was 82.77 ± 9.80 µg/dL. Patients exhibited a statistically significant lower skin hydration observed by corneometer as well as elasticity. The adjusted ORs of having dry skin and lower elasticity were 15.32 (95% CI 4.41-53.24), P < 0.001) and 1.96 (95% CI 1.06-3.60), P = 0.031), respectively. These differences were not significant for sebum content, TEWL, pH and pigmentation. CONCLUSION: Importantly, even in normal-appearing skin, level of hydration and elasticity decreased in lead-intoxicated patients. These results suggest that lead might possess harmful effects on the skin at measurable levels.

Life expectancy of HIV-positive people after starting combination antiretroviral therapy: a meta-analysis.

OBJECTIVES: Life expectancy is an important indicator informing decision making in policies relating to HIV-infected people. Studies estimating life expectancy after starting combination antiretroviral therapy (cART) have noted differences between income regions. The objective of our study was to perform a meta-analysis to assess life expectancy of HIV-positive people after starting cART, and to quantify differences between low/middle- and high-income countries. METHODS: Eight cohort studies estimating life expectancy in HIV-positive people initiating cART aged ≥ 14 years using the abridged life table method were identified. Random effects meta-analysis was used to pool estimated outcomes, overall and by income region. Heterogeneity between studies was assessed with the I2 statistic. We estimated additional years of life expected after starting cART at ages 20 and 35 years. RESULTS: Overall life expectancy in high-income countries was an additional 43.3 years [95% confidence interval (CI) 42.5-44.2 years] and 32.2 years (95% CI 30.9-33.5 years) at ages 20 and 35 years, respectively, and 28.3 (95% CI 23.3-33.3) and 25.6 (95% CI 22.1-29.2) additional years, respectively, in low/middle-income countries. In low/middle-income countries, life expectancy after starting cART at age 20 years was an additional 22.9 years (95% CI 18.4-27.5 years) for men and 33.0 years (95% CI 30.4-35.6 years) for women, but was similar in the two sexes in high-income countries. In all income regions, life expectancy after starting cART increased over calendar time. CONCLUSIONS: Our results suggest that the life expectancy of HIV-positive people after starting cART has improved over time. Monitoring life expectancy into the future is important to assess how changes to cART guidelines will affect patient long-term outcomes.

In-vivo and ex-vivo tests for culprit drugs identification in severe cutaneous adverse drugs reactions.

Drug causality assessment in severe cutaneous adverse reactions (SCARs) remains challenging. We investigated the usefulness of in-vivo drug patch tests (PT), ex-vivo interferon (IFN)-γ enzyme-linked immunospot (ELISpot) assay, and lymphocyte transformation test (LTT) in 30 SCARs patients within the past 36 months. Drug PT yielded a 20% positivity rate (n = 6), while IFN-γ ELISpot and LTT showed positive rates of 56.67% (n = 17) and 41.38% (n = 12), respectively. Combining the three tests resulted in an overall positive rate of 66.67% (n = 20) of cases. IFN-γ ELISpot offered additional positivity, especially with oxypurinol. Employing a combined diagnostic approach may enhance the chances of obtaining a positive result.

Dynamics of cognitive change in HIV-infected individuals commencing three different initial antiretroviral regimens: a randomized, controlled study.

BACKGROUND: Improvements in neurocognitive (NC) function have been associated with commencing antiretroviral therapy in HIV-infected subjects. However, the dynamics of such improvements are poorly understood. METHODS: We assessed changes in NC function via a validated computerized battery (CogState™, Melbourne, Victoria, Australia) at baseline and after 24 and 48 weeks in a subset of therapy-naïve neuro-asymptomatic HIV-infected subjects, randomized to commence three different antiretroviral regimens. RESULTS: Of 28 subjects enrolled in the study, nine, eight and 11 were randomly allocated to commence tenofovir/emtricitabine with efavirenz (arm 1), atazanavir/ritonavir (arm 2) and zidovudine/abacavir (arm 3), respectively. Overall improvements in NC function were observed at week 24 and function continued to improve at week 48 (changes in z-score for overall cognitive global score of 0.16 and 0.18 at weeks 24 and 48, respectively). Within the NC speed domains, generally greater improvements were observed in arms 2 and 3, compared with arm 1 (changes in z-score for composite speed scores at weeks 24/48 of 0.16/0.16, -0.29/-0.24 and -0.15/-0.31 in arms 1, 2 and 3, respectively; P = 0.04 for change at week 48 in arm 3 versus arm 1). Finally, improvements in executive function occurred later (only observed at week 48) and were driven by improvements in arm 3 (z-score changes of 0.23, 0.06 and -0.78 in arms 1, 2 and 3, respectively; P = 0.02 for change in arm 3 versus arm 1). CONCLUSION: Improvements in NC function continue over the first year after initiating antiretroviral therapy in neuro-asymptomatic HIV-infected subjects.

Tunable stiffness enables fast and efficient swimming in fish-like robots.

Fish maintain high swimming efficiencies over a wide range of speeds. A key to this achievement is their flexibility, yet even flexible robotic fish trail real fish in terms of performance. Here, we explore how fish leverage tunable flexibility by using their muscles to modulate the stiffness of their tails to achieve efficient swimming. We derived a model that explains how and why tuning stiffness affects performance. We show that to maximize efficiency, muscle tension should scale with swimming speed squared, offering a simple tuning strategy for fish-like robots. Tuning stiffness can double swimming efficiency at tuna-like frequencies and speeds (0 to 6 hertz; 0 to 2 body lengths per second). Energy savings increase with frequency, suggesting that high-frequency fish-like robots have the most to gain from tuning stiffness.

Monocyte-to-lymphocyte ratio as a predictor of TB among people living with HIV.

BACKGROUND: Diagnostic tools to identify incipient or subclinical TB stages will be helpful for preventive intervention. A simple biomarker to predict TB may be the monocytes to lymphocytes ratio (ML ratio) in peripheral blood.METHODS: We assessed the relationship between multiple time-updated ML ratio measurements and incidence of TB in people living with HIV (PLWH) after antiretroviral therapy (ART) was initiated. The ML ratio was updated at least every 6 months. TB incidence with corresponding 95% confidence intervals stratified according to time-updated ML ratio was calculated using ML ratio in quartiles.RESULTS: A total of 1305 PLWH were included in the analyses: 46 had incident TB and 1259 remained TB-free. The TB incidence rate was 10.3 (95% CI 7.1-14.9) cases/1000 patient-years (PYR) among participants with ML ratio ≥0.25 compared with 1.1/1000 PYR (95% CI 0.4-2.9) among those with ML ratio <0.15. At cut-point 0.23, the ML ratio provided a diagnostic area under the receiver operating characteristics curve (AROC) of 0.849 (95% CI 0.784-0.914) and a sensitivity of 85% and specificity of 71%.CONCLUSION: Increased ML ratio was predictive of incident TB among PLWH on or after ART. The ML ratio can be a simple tool to stratify the risk of TB in PLWH.

Performance characteristics and optimal cut-off value of triple adenylate nucleotides test versus adenosine triphosphate test as point-of-care testing for predicting inadequacy of duodenoscope reprocessing.

BACKGROUND: Adenosine triphosphate (ATP) test based on one nucleotide has been applied as point-of-care testing (POCT) for bacterial contamination in the medical and food industries. Hypothetically, testing three adenylate nucleotides (A3) may provide better detection of duodenoscope bacterial contamination than ATP test. AIM: To evaluate performance characteristics and optimal cut-off value of A3 and ATP tests in predicting bacterial contamination of duodenoscopes. METHODS: Four hundred duodenoscope samples obtained after 100 endoscopic retrograde cholangiopancreatography procedures were randomized into group A (A3 test) or B (ATP test). Samples were collected from the elevator at the four-step cleaning process of duodenoscope. We defined the new cut-off value of the test for reaching 100% negative predictive value (NPV) from our receiver operating characteristic (ROC). FINDINGS: Using the cultures from the four-step cleaning process as the reference, the areas under ROC (AUROC) were 0.83 and 0.84 for group A (N = 200) and group B (N = 200), respectively. Using the cultures from post-high-level disinfection (HLD) as the reference, the AUROC were 0.35 and 0.74 for group A (N = 50) and group B (N = 50), respectively. We investigated ATP as a POCT after HLD with a new cut-off value of 40 RLU. However, this threshold did not allow detection of low numbers of bacteria. CONCLUSION: A3 and ATP tests provide good performances in predicting bacterial contamination of duodenoscopes for the four-step cleaning process. The ATP <40 RLU is helpful as a POCT after HLD; however, the limitation of this cut-off value is its inability to detect low numbers of bacteria.

Karyotype and tumorigenicity of 1-methylguanine-transformed Chinese hamster cells.

Chinese hamster embryo cells transformed with the tRNA catabolite 1-methylguanine were characterized by Giemsa-banded karyotyping and by their tumorigenic potency in athymic nude mice. All seven 1-methylguanine-transformed cell lines were hyperdiploid with a modal chromosome number of 23. Three of these lines had an additional marker chromosome derived from the long (q) arm of chromosome no. 4, and they had alterations of chromosome no. 5 as well. Two of these three cell lines were tumorigenic. Nonrandom chromosome changes were observed in the other four 1-methylguanine-transformed cell lines, which included the addition of all or a portion of chromosome no. 6. One of these cell lines was also tumorigenic in nude mice, Specific cytogenetic changes were observed in most 1-methylguanine-transformed populations in contrast to the karyotypic heterogeneity of a benzo[a]pyrene-transformed cell line.

Interaction of normal and tumor transfer RNA methyltransferases with ethionine-induced methyl-deficient rat liver transfer RNA.

The tRNA methyltransferases from normal rat liver and Novikoff hepatoma have been compared with respect to their base specificity, capacity to methylate, and reaction kinetics, using mixed Escherichia coli B transfer RNA (tRNA) and ethionine-induced partially methyl-deficient rat liver tRNA. The pattern of base methylation of the two substrates is different with the use of enzymes from either source. In particular, N1-methylguanine methylation is much greater in the methyl-deficient rat liver tRNA. The enzymes from the two sources also show differences in specificity of base methylation in either substrate, particularly in the percentage of N2-methylguanine synthesized. The Novikoff hepatoma enzymes have a greater capacity for methylation with either type of tRNA than do rat liver enzymes. The methyl-deficient rat liver tRNA is a poorer substrate for the enzymes from both sources than is E. coli B tRNA in terms of rate of methylation as well as total acceptance of methyl groups. The affinity constants are somewhat higher for the methyl-deficient rat liver tRNA than for E. coli B tRNA. The Novikoff hepatoma enzymes, in general, have larger affinity constants than the rat liver enzymes. Maximal velocities for the various base-specific enzymes are lower with the methyl-deficient rat liver tRNA, with the exception of the 1-methylguanine specific enzymes. These enzymes from either rat liver or Novikoff hepatoma exhibit approximately a 2.5-fold greater maximal velocity with methyl-deficient rat liver tRNA.

Alteration of glycine N-methyltransferase activity in fetal, adult, and tumor tissues.

Glycine N-methyltransferase activity has been examined in a number of fetal and adult organs, as well as in several rodent hepatomas, using both enzymatic and immunological techniques. In fetal rabbit liver, the activity first appears at a low level at about 20 days postfertilization and rises to high levels after birth, reaching maximum in the adult liver. In fast-growing hepatomas, the activity could not be detected by either enzymatic or immunological assay. It could be detected in the slower-growing hepatomas, but in considerably diminished levels compared with that of normal adult rat liver. Immunoassays gave no evidence for inactive forms of the enzyme in the tissues that had no enzymatic activity. Transfer RNA methyltransferase assays carried out simultaneously showed an inverse relationship to the glycine N-methyltransferase activity. The levels of transfer RNA methyltransferase activity were high in fetal and tumor tissues and lower in normal adult tissues.

Altered growth properties of Chinese hamster cells exposed to 1-methylguanine and 7-methylguanine.

Primary Chinese hamster embryo cell cultures generally yield cell lines with a finite lifetime in culture. However, if early-passage cells are exposed chronically to either of two normal degradation products of transfer RNA, 1-methylguanine or 7-methylguanine, they are converted to continuous lines with altered growth characteristics and morphology. The continuous cell lines have saturation densities 2- to 10-fold higher than did finite control cultures, and some have the ability to grow in soft agar. Certain cultures have the general appearance of fibroblasts while others are more epithelial-like. Quantitative and qualitative alterations in the transfer RNA methyltransferases are early markers for neoplastic transformation in vivo and in vitro. Transfer RNA methyltransferase activity in the continuous lines is elevated compared to that of finite Chinese hamster cells. Neoplastic transformation has been demonstrated for a 1-methylguanine-derived line, and both 1-methylguanine- and 7-methylguanine-treated cell lines exhibit characteristics similar to those of Chinese hamster cells transformed with the carcinogen 3,4-benzopyrene or the DNA tumor virus SV40.

Cervical cytological abnormalities and HPV infection in perinatally HIV-infected adolescents.

BACKGROUND: Behaviourally HIV-infected adolescent females are at higher risk for abnormal cervical cytology and HPV infection compared to those who are uninfected, but data on perinatally HIV-infected adolescent females are lacking. METHODS: Cervical cytology, HPV infection and E6/E7 mRNA were assessed in sexually active 12-24-year-old adolescent females: perinatally HIV-infected (group 1, n = 40), behaviourally HIV-infected (group 2, n = 10), and HIV-uninfected (group 3, n = 10). RESULTS: Median age was lower in group 1 (18 years) than in groups 2 (24 years) and 3 (20.5 years) (P < 0.001), and median time since sexual debut was shorter: 2 vs 5 vs 4 years (P < 0.001). More trial participants in group 1 than group 2 were on antiretrovirals (90% vs 70%; P <0.001). Abnormal cervical cytology (atypical squamous cells of undetermined significance and higher) was observed in 30% (group 1), 40% (group 2) and 30% (group 3) (P = 0.92), whereas high-risk HPV infection was observed in 45%, 45% and 40%, respectively (P = 1.00). Positive E6/E7 mRNA was found in 28% of group 1, but not in other groups. High-risk HPV infection predicted abnormal cytology in all groups [OR 6.77, 95% confidence interval (CI) 1.99-23.0; P = 0.001). Additionally, plasma HIV RNA ≥50 copies/mL (OR 13.3, 95% CI 1.16-153.06; P = 0.04) predicted abnormal cytology in HIV-infected adolescent females. CONCLUSIONS: Despite the younger age and shorter time since sexual debut, cervical cytological abnormalities and HPV infection were as common in perinatally HIV-infected as in behaviourally infected and uninfected adolescents. HPV vaccination, pre-cancer screening and antiretroviral treatment in HIV-infected female adolescents should be implemented to minimise the risk of cervical cancer.

Chronic exposure of human neurons to quinolinic acid results in neuronal changes consistent with AIDS dementia complex.

OBJECTIVE: Concentrations of quinolinic acid, an N-methyl-D-aspartate agonist, are often elevated for long periods of time in the cerebrospinal fluid (CSF) and brain tissue of patients with AIDS dementia complex (ADC). This study was designed to test the hypothesis that chronic exposure of human neurons to quinolinic acid levels equivalent to those in the CSF of ADC patients is neurotoxic. DESIGN AND METHODS: Human fetal brain 14-16 weeks post-menses was cultured in medium with no detectable levels of quinolinic acid. After 4 weeks, 350 or 1200 nmol/l quinolinic acid was added to the feeding medium for a further 5 weeks. Neurotoxicity was evaluated using immunohistochemistry, transmission and scanning electron microscopy, and image analysis. RESULTS: A total of 1200 nmol/l quinolinic acid caused altered cell associations, a decrease in cell density and decreased microtubule-associated protein (MAP)-2 immunoreactivity compared with cultures exposed to 350 nmol/l quinolinic acid or controls. Image analysis of neurons in randomly selected fields revealed significantly swollen cells (P < 0.0001) compared with those treated with 350 nmol/l quinolinic acid or controls. Dendritic varicosities and discontinuous microtubular arrays were present in neurons exposed to both quinolinic acid concentrations, but not in control cultures. CONCLUSIONS: This study is the first to assess quinolinic acid levels in the experimental medium, and demonstrates that chronic exposure of human neurons to concentrations of quinolinic acid equivalent to those in the CSF of patients with ADC leads to alterations in dendritic ultrastructure and MAP-2 immunoreactivity, which is consistent with ADC pathology.

Quinolinic acid production by macrophages stimulated with IFN-gamma, TNF-alpha, and IFN-alpha.

Quinolinic acid (QUIN) has been associated with several inflammatory neurologic disorders, including AIDS dementia complex (ADC). Recent studies suggest that activation of macrophages with either HIV-1 or interferon-gamma (IFN-gamma) can lead to QUIN production. However, the importance of other cytokines, especially those related to the macrophage and that are especially important in ADC pathogenesis, remains unclear. We, therefore, sought to determine the role of tumor necrosis factor-alpha (TNF-alpha) and IFN-alpha in the production of QUIN. Primary human macrophages were stimulated with two different concentrations of these cytokines alone, in combination with each other, and with IFN-gamma. QUIN concentrations in the supernatants were then measured by mass spectrometry at 24, 48, and 72 hs. Results at 72 h showed significant increases in QUIN production in the cells stimulated with IFN-gamma (10297 +/- 170 nmol/L) and also in those stimulated with IFN-alpha (3600 +/- 113 nmol/L), whereas TNF-alpha-stimulated macrophages produced low levels of QUIN (1108 +/- 23 nmol/L). Macrophages stimulated with the cytokine combinations TNF-alpha and IFN-gamma, IFN-alpha, and IFN-gamma, and TNF-alpha and IFN-alpha also resulted in increases in QUIN production (11471 +/- 77.6 nmol/L, 16656 +/- 184 nmol/L, and 3369 +/- 120.5 nmol/L, respectively). The increases in QUIN production in all of the cytokine treatments approached or exceeded in vivo concentrations of QUIN that have been shown to be neurotoxic. These data further support a role for QUIN in cytokine-mediated neuronal death in inflammatory disorders of the brain, especially ADC.

IFN-beta1b induces kynurenine pathway metabolism in human macrophages: potential implications for multiple sclerosis treatment.

Interferon-beta(1b) (IFN-beta(1b)) has limited efficacy in the treatment of relapsing-remitting multiple sclerosis (RRMS). The kynurenine pathway (KP) is chiefly activated by IFN-gamma and IFN-alpha, leading to the production of a variety of neurotoxins. We sought to determine whether IFN-beta(1b) induces the KP in human monocyte-derived macrophages, as one explanation for its limited efficacy. Serial dilutions of IFN-beta(1b) (at concentrations comparable to those found in the sera of IFN-beta(1b)-treated patients) were added to human macrophage cultures. Supernatants were collected at various time points and assayed for the KP end product, quinolinic acid (QUIN). The effect of IFN-beta(1b) on the KP enzymes indoleamine 2,3-dioxygenase (IDO), 3-hydroxyanthranilate dioxygenase (3HAO), and quinolinate phosphoribosyltransferase (QPRTase) mRNA expression was assessed by semiquantitative RT-PCR. IFN-beta(1b) (> or =10 IU/ml) led to increased mRNA expression of both IDO and QUIN production (7901 +/- 715 nM) after 72 h at 50 IU/ml IFN-beta(1b) (p < 0.0001). This study demonstrates that IFN-beta(1b), in pharmacologically relevant concentrations, induces KP metabolism in human macrophages and may be a limiting factor in its efficacy in the treatment of MS. Inhibitors of the KP may be able to augment the efficacy of IFN-beta in MS.

Kynurenine pathway inhibition reduces neurotoxicity of HIV-1-infected macrophages.

The AIDS dementia complex (ADC) is a consequence of excessive immune activation driven at least in part by systemic HIV infection and probably brain infection. Quinolinic acid (QUIN) is a neurotoxic tryptophan metabolite produced by macrophages in response to stimulation with cytokines or infection with HIV-1. Consequently it has been implicated in ADC pathogenesis. However, macrophages infected with HIV-1 synthesize numerous neurotoxic substances. Therefore we conducted experiments using human fetal brain tissue to determine the relative importance of QUIN as a neurotoxin in ADC. Human macrophages were infected with HIV-1 in vitro using a viral isolate from a demented patient. 6-Chloro-D-tryptophan, an inhibitor of QUIN biosynthesis, was added to half the macrophage cultures to block formation of QUIN. Supernatants containing QUIN (SQpos) or in which QUIN biosynthesis had been inhibited (SQneg) were then added to human fetal brain aggregate cultures. Toxicity was evaluated using lactate dehydrogenase efflux, trypan blue exclusion, immunohistochemistry, image analysis, and electron microscopy. Each technique showed a reduction of toxicity in SQneg-treated cultures. These studies confirm the significance of QUIN as a neurotoxin in ADC and suggest that neuroprotective strategies may have a place in the treatment of this disease.

Transfer of the methyl group of methionine to choline and to tRNA in the honeybee Apis mellifica L.

Contrary to some previous reports on the absence of biological transmethylation reactions in some insect species, the transfer of the methyl group of methionine-methyl 14C leading to choline and to methylated bases in tRNA was shown in the honeybee Apis mellifica. The addition of antibiotics to the food of the insect does not diminish the incorporation of radioactivity, proving that intestinal bacteria are not responsible for the methylation reactions observed.

Elevated levels of eukaryotic translation initiation factor eIF-4E, mRNA in a broad spectrum of transformed cell lines.

Translation initiation factor eIF-4E, which binds to the 5' cap structure of eukaryotic mRNAs, is believed to play an important role in the control of cell growth. Over-expression of eIF-4E in fibroblasts results in their malignant transformation. However, no information on eIF-4E expression in established transformed cell lines has been available. We report here that a variety of tumor cell lines, chemically, virally and oncogenically transformed, exhibit elevated levels of eIF-4E mRNA expression as compared to their normal counterparts. Overexpression of eIF-4E, which is normally rate-limiting in protein synthesis, may stimulate the translation of regulatory and oncogenic proteins involved in transformation.