Assessment of cardiac diastolic dysfunction in HIV-infected people without cardiovascular symptoms in China

This study assessed cardiac diastolic dysfunction (DD) in HIV-infected subjects without cardiovascular symptoms in China. Eighty-four HIV-infected patients without cardiovascular symptoms were recruited and compared with 30 HIV-negative control subjects. Cardiac DD was evaluated using echocardiography including tissue Doppler imaging. DD was detected in 47.6% of AIDS patients and 42.8% of HIV-positive patients, which was significantly higher than in HIV-negative controls. After logistic regression analysis, HIV infection was independently correlated with cardiac DD (P < 0.05). Among HIV-positive subjects, logistic regression analysis showed that zidovudine exposure was associated with higher prevalence of DD (P < 0.05). Asymptomatic cardiac DD was observed frequently in HIV-infected subjects. HIV infection itself and zidovudine exposure were correlated with a higher prevalence of cardiac DD.

Magnetic resonance volumetric assessments of brains in fetuses with ventriculomegaly correlated to outcomes

OBJECTIVES

The purpose of this study was to correlate 2-dimensional magnetic resonance (MR) measurements of lateral ventricular width and 3-dimensional measurements of lateral ventricular and supratentorial parenchymal volumes to postnatal outcomes in fetuses with ventriculomegaly.

METHODS

A total of 307 fetuses (mean gestational age, 26.0 weeks; range, 15.7-39.4 weeks) had MR volumetry after referral for ventriculomegaly. Fetuses were grouped into those with (n = 114) and without (n = 193) other central nervous system (CNS) anomalies. Pregnancy and postnatal neurodevelopmental outcomes up to 3 years of age were obtained. A subgroup analysis was performed excluding fetuses with other CNS anomalies. Logistic regression analysis was performed to assess which measurement was most predictive of outcomes.

RESULTS

There were 50 terminations, 2 stillbirths, and 255 live births. Seventy-five cases were lost to follow-up. Among 180 live-born neonates with follow-up, 140 had abnormal and 40 had normal outcomes. Atrial diameter (P < .0001), frontal horn diameter (P < .0001), and ventricular volume (P = .04) were predictive of live birth, with 92% specificity at 60% sensitivity. Among fetuses without other CNS anomalies, 180 of 193 pregnancies (93%) resulted in live deliveries, with atrial diameter (P < .0001), frontal horn diameter (P = .003), and ventricular volume (P = .008) associated with live birth and atrial diameter having the highest specificity (>99% at 60% sensitivity). Parenchymal volume was not associated with normal or abnormal outcomes (either live birth versus death or normal versus abnormal neurodevelopmental outcome). Among live-born neonates, no age-adjusted threshold for any of the measurements reliably distinguished between normal and abnormal neurodevelopmental outcomes.

CONCLUSIONS

Ventricular volume and diameter, but not parenchymal volume, correlate with live birth in fetuses with ventriculomegaly. However, once live born, neither 2- nor 3-dimensional measurements can distinguish a fetus that will have a normal outcome.

Ursolic acid promotes robust tolerance to cardiac allografts in mice

Nuclear factor (NF)-κB is an important molecule in T cell activation. Our previous work has found that T cell-restricted NF-κB super-repressor (IκBαΔN-Tg) mice, expressing an inhibitor of NF-κB restricted to the T cell compartment, can permanently accept fully allogeneic cardiac grafts and secondary donor skin grafts. In this study, we explore if transient NF-κB inhibition by a small molecular inhibitor could induce permanent graft survival. Ursolic acid, a small molecular compound, dose-dependently inhibited T cell receptor (TCR)-triggered NF-κB nuclear translocation and T cell activation in vitro. In vivo, ursolic acid monotherapy prolonged significantly the survival of cardiac allograft in mice. Assisted with donor-specific transfusion (DST) on day 0, ursolic acid promoted 84·6% of first cardiac grafts to survive for more than 150 days. While the mice with long-term surviving grafts (LTS) did not reject the second donor strain hearts for more than 100 days without any treatment, they all promptly rejected the third-party strain hearts within 14 days. Interestingly, this protocol did not result in an increased proportion of CD4(+) CD25(+) forkhead box P3(+) regulatory T cells in splenocytes. That adoptive transfer experiments also did not support regulation was the main mechanism in this model. Splenocytes from LTS showed reduced alloreactivity to donor antigen. However, depletion of CD4(+) CD25(+) regulatory T cells did not alter the donor-reactivity of LTS splenocytes. These data suggest that depletion of donor-reactive T cells may play an important role in this protocol.

In vivo assessment of chitosan/β-glycerophosphate as a new liquid embolic agent

We sought to assess the feasibility of using thermosensitive chitosan/β-glycerophosphate forembolotherapy. The renal arteries in nine rabbits were embolized with chitosan/β-glycero-phosphate. The animals were studied angiographically and sacrificed at one week (n = 3), four weeks (n = 3), and eight weeks (n = 3) after embolotherapy. Histology was obtained at these three time points. Delivery of chitosan/β-glycerophosphate was successful in all cases. Complete occlusion was achieved in all cases. No recanalization was observed in the follow-up angiograms. No untoward inflammatory reactions were observed in the target renal arteries and infarcted kidneys during the histological examinations. Our preliminary feasibility evaluation in rabbit renal arteries indicates that C/GP is a satisfactory embolization agent.

Cancer therapy by targeting hypoxia-inducible factor-1

Tumors are invariably less well-oxygenated than the normal tissues from which they arose. Hypoxia-inducible factor-1 (HIF-1), a key transcriptional regulator, plays a central role in the adaptation of tumor cells to hypoxia by activating the transcription of genes, which regulate several biological processes including angiogenesis, cell proliferation, survival, glucose metabolism and migration. The expression, activity and stability of HIF-1 is not only induced in response to reduced oxygen availability but also modulated through PI-3K, MAPK, autocrine signaling pathways, E3 ubiquitin ligases, and other regulators. The regulators and effects of HIF-1 in cancer have intensively provided us a new clue for the HIF-1 targeting anticancer therapy. This review evaluates the HIF-1 structure, the regulation mechanisms, the functions in cancer and corresponding anticancer strategies.

Genetic variation of chicken MC1R gene in different plumage colour populations

1. Genetic variation in the chicken MC1R gene was analysed through bioinformatic methods after polymerase chain reaction (PCR) amplification and sequencing of the coding region of MC1R gene from 5 different populations with 4 plumage colours (black, grey plumage with black spots, yellow plumage with black spots, red). 2. A total of 11 novel variations were detected in Hebei chickens, of which 8 were non-synonymous. Allele distribution analysis showed that the wild-type e(+) (Brown Leghorn) allele was mainly found in Hy-Line Brown and Lohmann Brown, the dominant Extended black E(AY220304) allele was mainly found in Hebei chicken with black plumage, whereas the Buttercup (e(bc)) allele was rare. 3. Nucleotide diversity (π) within each colour strain of Hebei chickens (0·0047-0·0052) was significantly greater than that of Hy-Line Brown (0·0024) or Lohmann Brown (0·0043). 4. The results indicate that there is abundant polymorphism in the MC1R gene, especially in Hebei chicken, which was associated with its rich plumage colour diversity.

Long-term ginsenoside administration prevents memory loss in aged female C57BL/6J mice by modulating the redox status and up-regulating the plasticity-related proteins in hippocampus

Memory impairment is considered to be one of the most prominent consequences of aging. Deterioration of memory begins in advance of old age in animals, including humans. The generation of reactive oxygen species (ROS) and/or free radicals-induced oxidative stress which is the major age-related changes, can lead to hippocampus damage and increase vulnerability to impaired learning and memory. Ginsenoside, the effective ingredient of ginseng, has been reported to have a neuron beneficial effect. In the present study, C57BL/6J mice aged 12 months were chronically treated with ginsenoside (three dose groups were given ginsenoside in drinking water for 8 months, the concentration of ginsenoside in drinking water was 0.028%, 0.056%, and 0.112% (w/v), respectively). Placebo-treated aged mice and young ones (4 months old) were used as controls. The efficacious effect of ginsenoside was manifested in the amelioration of memory impairment in aged mice by Morris water maze and step-down tests. Total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and thiobarbituric acid reactive substances (TBARS) have been used as the biomarkers of oxidative stress. In ginsenoside treated groups, the activities of T-SOD and GSH-Px markedly increased, and the levels of TBARS and the content of protein carbonyl decreased significantly in serum and in hippocampus. The activation of lipofuscin formation, disruption or loss of cristae in mitochondria, the irregular nucleus and condensed chromatin laid against the nuclear membrane in pyramidal cells of hippocampal CA1 region, which are all related to oxidative stress, were also reduced after ginsenoside treatment. Processes of memory formation and functional plasticity are associated with postsynaptic density-95 (PSD-95), protein kinase Cγ subunit (PKCγ) and brain derived neurotrophic factor (BDNF). In the present study, we found that long-term ginsenoside treatment prevented age-related reductions of PSD-95, PKCγ, and BDNF in the hippocampus. These results demonstrated that long-term ginsenoside administration may prevent memory loss in aged C57BL/6J mice by modulating the redox status and up-regulating the plasticity-related proteins in hippocampus.

Search for effects beyond the born approximation in polarization transfer observables in e(over→)p elastic scattering

Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, G(E)/G(M), obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic H(e[over →],e(')p[over →]) reaction for three different beam energies at a Q(2)=2.5  GeV(2), spanning a wide range of the kinematic parameter ε. The ratio R, which equals μ(p)G(E)/G(M) in the Born approximation, is found to be independent of ε at the 1.5% level. The ε dependence of the longitudinal polarization transfer component P(ℓ) shows an enhancement of (2.3±0.6)% relative to the Born approximation at large ε.

Effects of Metformin and Rosiglitazone on Peripheral Insulin Resistance and β-Cell Function in Obesity: A Double-Blind, Randomized, Controlled Study

Metformin and rosiglitazone combination therapy is known to improve insulin resistance and postpone diabetes mellitus development in subjects with impaired glucose tolerance. This double-blind, randomized, controlled study assessed this combination therapy for preventing type 2 diabetes in obese subjects with hyperinsulinaemia. Subjects received metformin (500 mg three times daily, orally) plus either rosiglitazone (4 mg once daily, orally; n = 94) or placebo ( n = 95) and were followed for 6 months. Blood pressure, body fat, body mass index (BMI), lipid and insulin levels were recorded pre-and post-treatment. Metformin plus rosiglitazone significantly decreased blood pressure, lipids, BMI, and fasting and postmeal insulin levels. Metformin plus placebo led to a significant decrease in blood pressure, BMI and lipid levels, but fasting and postmeal insulin levels were unchanged. Adverse events were similar between the two groups. The metformin and rosiglitazone combination increased insulin sensitivity and β-cell function recovered. This approach may represent a therapeutic option for preventing development of type 2 diabetes in obese subjects with hyperinsulinaemia.

MiR-148a promotes apoptosis by targeting Bcl-2 in colorectal cancer

Apoptosis has a vital role in maintaining tissue homeostasis, and dysregulation of the apoptotic pathway is now widely recognized as a key step in tumourigenesis. Increasingly, evidence has demonstrated that microRNA (miRNA) can exert various biological functions in tumours by targeting oncogenes or tumour suppressors. Nevertheless, the role of miRNA in apoptosis remains unclear. Here we show that ectopical expression of miR-148a can induce apoptosis in colorectal cancer cells. In addition, MYB can inhibit miR-148a by directly acting on the transcription factor binding site in miR-148a gene and miR-148a can posttranscriptionally silence Bcl-2. Subsequently, the intrinsic apoptosis pathway is activated by releasing cytochrome c, cleaving caspase 9, caspase 3 and PARP, which eventually induce cancer-cell apoptosis. These findings are part of a hitherto undocumented apoptotic regulatory pathway in which a pleiotropic transcription factor controls the expression of a miRNA and the miRNA inhibits the target, leading to activation of an intrinsic mitochondrial pathway and tumour apoptosis.

Functional Effect of Platelet Membrane Glycoprotein Ia Gene Polymorphism in the Pathogenesis of Unstable Angina Pectoris

The functional effect of platelet membrane glycoprotein Ia ( GPIa) gene 807C/T polymorphism in unstable angina pectoris (UAP) pathogenesis was investigated in Chinese Han individuals. Collagen type I-induced platelet aggregation was measured in 33 healthy subjects. Plasma levels of α-granule membrane protein (GMP-140) were measured in 33 healthy subjects and in 35 patients with recentonset angina at rest within 24 h of hospitalization. Platelet membrane GPIa gene 807C/T polymorphism was determined in all subjects. Lag-time before 30% platelet aggregation was significantly longer in CC genotype than in TC genotype healthy subjects, although there was no significant difference in maximal platelet aggregation between healthy subjects with either genotype. Plasma GMP-140 levels were significantly higher in TC genotype patients compared with CC genotype patients or healthy subjects; a significant difference was also observed between the latter two groups. It was concluded that rapid initiation of collagen-induced platelet aggregation may be associated with the platelet membrane GPIa T807 allele, which may be important in UAP pathogenesis.

Detection of rpoB, katG and inhA gene mutations in Mycobacterium tuberculosis clinical isolates from Chongqing as determined by microarray

The emergence of multidrug-resistance Mycobacterium tuberculosis is an increasing threat to tuberculosis control programmes. Susceptibility testing of Mycobacterium tuberculosis complex isolates by traditional methods requires a minimum of 14 days. This can be reduced significantly if molecular analysis is used. DNA sequencing is a good method for detecting mutation, but cannot be used routinely because of its relatively high cost. A sensitive and specific microarray has been designed to detect mutations in the rifampin resistance determining region of rpoB and loci in katG and inhA associated with isoniazid (INH) resistance. A panel of Mycobacterium tuberculosis isolates containing 13 different rpoB genotypes, two mutation genotypes within codon 315 of katG and one mutation genotypes at inhA was used to validate the microarray. The results obtained indicate that 100% of rifampicin-resistant M. tuberculosis strains isolated in Chongqing had rpoB mutations, with 531-Ser and 526-His being the most common positions substituted. Of the total 50 INH resistant isolates, 82% had a katG315 mutation and 18% had an inhA mutation. All the mutations detected by the microarray method were also confirmed by conventional DNA sequencing. It is demonstrated that the microarray is an efficient, specialized technique and can be used as a rapid method for detecting rifampin and isoniazid resistance.