Clinical evaluation of QuantiFERON®-TB Gold Plus directly compared with QuantiFERON®-TB Gold In-Tube and T-Spot®.TB for active pulmonary tuberculosis in the elderly

BackgroundReduced sensitivity of tuberculosis (TB) interferon-γ release assays (IGRAs) among the elderly has been reported, which is presumably due to diminished immune function. We evaluated the clinical performance of QuantiFERON®-TB Gold plus (QFT-Plus) compared with QuantiFERON®-TB Gold In-Tube (QFT-GIT) and T-Spot®.TB (T-SPOT) in the elderly.MethodsBlood samples for all three IGRAs were drawn at the same time from all the participants. Both CD4 and CD8 T-cell counts in patients’ peripheral blood were also measured.ResultsA total of 142 active pulmonary TB patients (median age: 84, interquartile range; 76–89 years) were recruited. The sensitivities of the tested IGRAs (excluding invalid/indeterminate cases) were as follows: QFT-Plus, 93.6%; QFT-GIT, 91.4%; and T-SPOT 68.1%. QFT-Plus displayed significantly higher sensitivity than T-SPOT (p < 0.00001). All three IGRAs exhibited the same specificity (100%), as assessed using blood samples from healthy, low TB-risk individuals (n = 118; median age: 39, IQR; 32–47 years). Positivity in 43 active TB patients with CD4 T-cell counts <200/μL, 39 of whom were ≥80 years of age, was as follows: QFT-Plus, 83.7%; QFT-GIT, 74.4%; and T-SPOT, 58.1%. The difference between TB2-TB1 of the QFT-Plus assay was statistically correlated with CD8 but not CD4 T-cell counts in blood (r = 0.193, p = 0.0298).ConclusionsQFT-Plus showed high performance in the detection of TB infection in patients irrespective of their advanced age (≥80 years) or lower CD4 counts. QFT-Plus can be useful for the diagnosis of TB infection in all patients, including those who are elderly and/or immunocompromised.     

Genetic polymorphism of human leucocyte antigen and susceptibility to multidrug‐resistant and rifampicin‐resistant tuberculosis in Han Chinese from Hubei Province

We determined the high‐resolution allele and haplotype frequencies at the human leucocyte antigen (HLA)A, B and DRB1 loci in the Han population of Hubei province, the TB endemic area of Central China, with pulmonary tuberculosis (PTB), and established the relationship between HLA‐A, B and DRB1 alleles as well as haplotypes and susceptibility to multidrug‐resistant and rifampicin‐resistant tuberculosis (MDR/RR‐TB). Blood samples were drawn from 174 patients with MDR/RR‐TB and 838 patients with drug‐susceptible PTB in ethnic Han population from Hubei province (central China). Four‐digit allele genotyping of HLA‐ A, B and DRB1 loci was performed using polymerase chain reaction with sequence‐specific oligonucleotide probes (PCR‐ SSOP). The allele and haplotype frequencies of HLA‐A, B and DRB1 were determined and compared between patients with MDR/RR‐TB and patients with drug‐susceptible PTB. Statistical analysis of the generated data indicated no departure from expectation of Hardy–Weinberg equilibrium (HWE) at all loci of the control group. Multivariate analysis identified allele DRB1*08:01 (p < .0001; OR = 174.5, 95% CI 15.3–1987.2) as independent predictor of MDR/RR‐TB, except for old age (p < .0001; OR = 10. 9, 95% CI 7.6–15.8), previous treatment history (p < .0001; OR = 11.0, 95% CI 7.2–16.7) and poor compliance to treatment (p < .0001; OR = 12.9, 95% CI 8.4–20.0). While in the subgroup of new TB cases, DRB1*08:01 (p < .0001; OR = 80.3, 95% CI 7.0–917.1) and older age (p < .0001; OR = 3.9, 95% CI 2.4–6.4) were independent susceptibility factors for primary MDR/RR‐TB. Our results suggest that a combination of clinical and host genetic information about tuberculosis patients may contribute to prediction and early detection of MDR/RR‐TB.     

Electrical stimulation of the cochlear nerve in rats: analysis of c-Fos expression in auditory brainstem nuclei

We investigated functional activation of central auditory brainstem nuclei in response to direct electrical stimulation of the cochlear nerve using c-Fos immunoreactivity as a marker for functional mapping. The cochlear nerve was stimulated in the cerebellopontine angle of Lewis rats applying biphasic electrical pulses (120-250 muA, 5 Hz) for 30 min. In a control group, bilateral cochlectomy was performed in order to assess the basal expression of c-Fos in the auditory brainstem nuclei. The completeness of cochlear ablations and the response of auditory brainstem nuclei to electrical stimulation were electrophysiologically verified. C-Fos immunohistochemistry was performed using the free floating method. In anaesthetized animals with unilateral electrical stimulation of the cochlear nerve, increased expression of c-Fos was detected in the ipsilateral ventral cochlear nucleus (VCN), in the dorsal cochlear nucleus bilaterally (DCN), in the ipsilateral lateral superior olive (LSO) and in the contralateral inferior colliculus (IC). A bilateral slight increase of c-Fos expression in all subdivisions of the lateral lemniscus (LL) did not reach statistical significance. Contralateral inhibition of the nuclei of the trapezoid body (TB) was observed. Our data show that unilateral electrical stimulation of the cochlear nerve leads to increased expression of c-Fos in most auditory brainstem nuclei, similar to monaural auditory stimulation. They also confirm previous studies suggesting inhibitory connections between the cochlear nuclei. C-Fos immunoreactivity mapping is an efficient tool to detect functional changes following direct electrical stimulation of the cochlear nerve on the cellular level. This could be particularly helpful in studies of differential activation of the central auditory system by experimental cochlear and brainstem implants.     

Effects of oral administration of levamisole on non-specific immunity, serum proteins and health in normal colostrum-fed neonatal dairy calves

Soon after levamisole became widely used as a veterinary anthelmintic, it was recognised that concurrent enhancement of immune responsiveness sometimes accompanied anthelmintic treatment, especially in old or chronically ill animals. There are many reports concerning the immunomodulatory effects of levamisole in immunocompromised and vaccinated animals, but information about the effects of levamisole in immunocompetent animals is limited and controversial. Thirty Holstein dairy calves were randomly divided into two groups: test (n=15) and control (n=15). Blood samples were taken from the jugular vein, between 24 h and 48 h after birth, and put into EDTA-containing tubes and plain tubes; levamisole was then administrated orally at a dose of 2 mg/kg body weight three times at 1-day intervals in test groups. Blood sampling from all the calves was continued at days 7, 14, 21 and 28. The weight of calves was measured only at days 1 and 28 (before feeding). The levels of packed cell volume (PCV) (microhaematocrit), total white blood cells (WBCS) and differential leukocyte count (manual standard methods), total serum protein (colorimetry), beta and gamma globulins (electrophoresis), albumin:globulin (A:G) (calculated) and disease occurrence were measured and recorded. Appropriate statistical methods were used for data analysis, and P0.05 was considered as significant. No significant differences were seen for PCV, total serum protein, WBC count and health between groups. In the test group, neutrophil level at day 14 and monocyte level at day 21 were significantly higher than in the control group (P<0.05). Electrophoresis showed no significant differences for beta globulin level and A:G between groups, but gamma globulin level at day 28 was significantly higher in the test group (P<0.05).     

Metal levels in fodder, milk, dairy products, and tissues sampled in ovine farms of Southern Italy

We measured Cd, Cr, Hg, Mn, and Pb levels in samples of fodder, milk, dairy products, and tissues collected from 12 ovine farms in the regions of Campania and Calabria (Southern Italy). The areas in which the farms are located show different levels of anthropogenic pressure. The main purpose of this study is the identification and the analysis of relationships among metal concentrations observed in samples representative of different links in the food chain. Particularly, we apply univariate, bivariate, and multivariate statistical techniques to identify the correlation structure of our data set and to evaluate the influence of anthropogenic activity. We discuss the results, focusing the analysis on the spatial and the temporal patterns of metal concentrations.     

Cloning of a cDNA encoding a novel marmoset CYP2C enzyme, expression in yeast cells and characterization of its enzymatic functions

We cloned a cDNA encoding a novel CYP2C enzyme, called P450 M-2C, from a marmoset liver. The deduced amino acid sequence showed high identities to those of human CYP2C8 (87%), CYP2C9 (78%) and CYP2C19 (77%). The P450 M-2C enzyme expressed in yeast cells catalyzed p-methylhydroxylation of only tolbutamide among four substrates tested, paclitaxel as a CYP2C8 substrate, diclofenac and tolbutamide as CYP2C9 substrates and S-mephenytoin as a CYP2C19 substrate. p-Methylhydroxylation of tolbutamide by marmoset liver microsomes showed monophasic kinetics, and the apparent K(m) value (1.2 mM) for the substrate was similar to that of the recombinant P450 M-2C (1.8 mM). Although all of the recombinant human CYP2C8, CYP2C9 and CYP2C19 expressed in yeast cells catalyzed tolbutamide p-methylhydroxylation, the kinetic profile of CYP2C8 was most similar to that of P450 M-2C. Tolbutamide oxidation by the marmoset liver microsomes and the recombinant P450 M-2C was inhibited most effectively by quercetin, a CYP2C8 inhibitor, followed by omeprazole, a CYP2C19 inhibitor, whereas sulfaphenazole, a CYP2C9 inhibitor, was less potent under the conditions used. These results indicate that P450 M-2C is the major tolbutamide p-methylhydroxylase in the marmoset liver.     

The clinical utility of cycle of threshold value of GeneXpert MTB/RIF (CBNAAT) and its diagnostic accuracy in pulmonary and extra-pulmonary samples at a tertiary care center in India

Background

There are knowledge gaps in the in-depth analysis of the most promising and robust diagnostic tool, GeneXpert MTB/RIF (CBNAAT). The cycle of threshold (CT) value of the CBNAAT test and its clinical implications has not been explored much.

Topographic principles in the spinal projections of serotonergic and non-serotonergic brainstem neurons in the rat

The spinal projections from the raphe-associated brainstem areas containing serotonergic neurons were studied with aldehyde-induced fluorescence in combination with the retrograde fluorescent tracer True Blue in the rat. This technique makes it possible to determine simultaneously the projections of individual neurons and to detect whether serotonin is present in the same neurons. After tracer injections into the spinal cord retrogradely labeled serotonergic and non-serotonergic neurons were found in the medullary raphe nuclei and adjacent regions and to a lesser extent in association with the dorsal and median raphe nuclei in the mesencephalon. Large True Blue injections that covered one side of the spinal cord at mid-cervical level labeled about 60% of the ipsilaterally situated serotonergic neurons in the medullary raphe regions while the corresponding figure contralaterally was about 25%. On both sides a larger number of labeled non-serotonergic neurons were found; these were sometimes located dorsal to, but often intermingled with, the serotonergic cells. While the serotonergic projection from the mesencephalon could not be labeled from injections below cervical levels, the labeling in more caudal brainstem regions exhibited only minor variations depending on the rostrocaudal level of the spinal segment injected. Furthermore, quantitative data from injections at different levels indicate that the majority of the spinal-projecting neurons traverse most of the length of the cord. Summarizing the results obtained from small injections restricted to subregions of the cord we feel that it is possible to distinguish three fairly distinct pathways for spinal projections from the medullary raphe and adjacent regions: The dorsal pathway originates mainly from cells in the caudal pons and rostral medulla oblongata (rostral part of nucleus raphe magnus, nucleus raphe magnus proper, nucleus reticularis gigantocellularis pars alpha and nucleus paragigantocellularis). This pathway, which contains a large non-serotonergic component, descends through the dorsal part of the lateral funiculus and terminates mainly in the dorsal horn at all spinal cord levels. The intermediate pathway is largely serotonergic with its cell bodies located within the arcuate cell group (situated just ventral and lateral to the pyramids very close to the ventral surface of the brainstem) and in the nucleus raphe obscurus and pallidus and terminates in the intermediate grey at thoracolumbar and upper sacral levels.(ABSTRACT TRUNCATED AT 400 WORDS)