Impact of Opiate–HIV-1 Interactions on Neurotoxic Signaling

Opiate drug abuse exacerbates the pathogenesis of human immunodeficiency virus-1 (HIV-1) in the central nervous system through direct actions on glia and neurons. Opiate abuse causes widespread disruption of astroglial and microglial function, and significant increases in astroglial-derived proinflammatory cytokines and chemokines, which likely contributes to neuronal dysfunction, death, and HIV encephalitis. Neurons are also directly affected by opiate–HIV-1 interactions. HIV-1 and the viral proteins gp120 and Tat activate multiple caspase-dependent and caspase-independent proapoptotic pathways in neurons involving phosphatidylinositol 3-kinase (PI3 kinase)/Akt, as well as p38, c-Jun N-terminal kinase (JNK) and/or other mitogen-activated protein kinases (MAPKs). Opiates appear to decrease the threshold for HIV-1-mediated neurotoxicity by sending convergent signals that exacerbate proapoptotic events induced by viral and cellular toxic products. The synergistic proinflammatory and neurotoxic effects of opiate drugs on glia and neurons are largely mediated through μ opioid receptors, which are expressed by subpopulations of astroglia, microglia, and neurons. Opiate abuse intrinsically modifies the host response to HIV-1. Identification of how this occurs is providing considerable insight toward understanding the mechanisms underlying HIV-1-associated dementia.     

Lipopolysaccharide fever is initiated via a capsaicin-sensitive mechanism independent of the subtype-1 vanilloid receptor

As pretreatment with intraperitoneal capsaicin (8-methyl-N-vanillyl-6-nonenamide, CAP), an agonist of the vanilloid receptor known as VR1 or transient receptor potential channel-vanilloid receptor subtype 1 (TRPV-1), has been shown to block the first phase of lipopolysaccharide (LPS) fever in rats, this phase is thought to depend on the TRPV-1-bearing sensory nerve fibers originating in the abdominal cavity. However, our recent studies suggest that CAP blocks the first phase via a non-neural mechanism. In the present work, we studied whether this mechanism involves the TRPV-1. Adult Long-Evans rats implanted with chronic jugular catheters were used. Pretreatment with CAP (5 mg kg(-1), i.p.) 10 days before administration of LPS (10 microg kg(-1), i.v.) resulted in the loss of the entire first phase and a part of the second phase of LPS fever. Pretreatment with the ultrapotent TRPV-1 agonist resiniferatoxin (RTX; 2, 20, or 200 microg kg(-1), i.p.) 10 days before administration of LPS had no effect on the first and second phases of LPS fever, but it exaggerated the third phase at the highest dose. The latter effect was presumably due to the known ability of high doses of TRPV-1 agonists to cause a loss of warm sensitivity, thus leading to uncontrolled, hyperpyretic responses. Pretreatment with the selective competitive TRPV-1 antagonist capsazepine (N-[2-(4-chlorophenyl)ethyl]-1,3,4,5-tetrahydro-7,8-dihydroxy-2H-2-benzazepine-2-carbothioamidem, CPZ; 40 mg kg(-1), i.p.) 90 min before administration of LPS (10 microg kg(-1), i.v.) or CAP (1 mg kg(-1), i.p.) did not affect LPS fever, but blocked the immediate hypothermic response to acute administration of CAP. It is concluded that LPS fever is initiated via a non-neural mechanism, which is CAP-sensitive but RTX- and CPZ-insensitive. The action of CAP on this mechanism is likely TRPV-1-independent. It is speculated that this mechanism may be the production of prostaglandin E(2) by macrophages in LPS-processing organs.     

A national survey in England of the routine examination of the newborn baby

OBJECTIVE: To identify current practices for the initial routine examination of healthy newborn babies, and determine the extent to which midwives are carrying out this examination. DESIGN AND PARTICIPANTS: Postal questionnaires were sent to consultant paediatricians and midwifery managers in all maternity units in England. Questionnaires were also sent to the 12 universities in England which run the N96 post-registration course in the examination of the newborn baby. FINDINGS: Questionnaires were returned from 197 (86%) maternity units. Senior house officers examined in 83% (160/193) a median of 92% of babies; 44% (74/167) had at least one midwife (median of two) with qualifications to carry out the examination and in 31% (51/167) some examinations were conducted by a midwife. However, a third of midwives with this qualification carried out no examinations, and nationally only about 2% of babies were examined by a midwife. Rates of referral by midwives and senior house officers were similar. Examinations were carried out between four and 48 hours from birth; most units considered six hours an acceptable minimum. An estimated 1% of babies were transferred home without routine examination; the GP was responsible for most (83-93%) of these babies' examinations; midwives for 10-23%; and senior house officers in hospital for 4-7%. Twelve per cent (23/194) of units carried out a second examination prior to discharge. Most respondents were in favour of midwives carrying out the examinations provided they were adequately trained. CONCLUSIONS: Many of the consultant paediatricians and midwifery managers stated that suitably trained midwives could routinely examine the healthy newborn baby; however, many currently N96 trained midwives were examining few or no babies. An extension of training would be needed were midwife examination to become general policy.     

Bioengineering and regeneration of gastrointestinal tissue: where are we now and what comes next?

Introduction: The field of tissue engineering and regenerative medicine has been applied to the gastrointestinal (GI) tract for a couple decades. Several achievements have been accomplished that provide promising tools for treating diseases of the GI tract.

Areas covered: The work described in this review covers the traditional aspect of using cells and scaffolds to replace parts of the tract. Several studies investigated different types of biomaterials and different types of cells. A more recent approach involved the use of gut-derived organoid units that can differentiate into all gut cell layers. The most recent approach introduced the use of organ-on-a-chip concept to understand the physiology and pathophysiology of the GI system.

Expert opinion: The different approaches tackle the diseases of the GI tract from different perspectives. While all these different approaches provide a promising and encouraging future for this field, the translational aspect is yet to be studied.     

Effect of subinhibitory concentrations of ciprofloxacin on Mycobacterium fortuitum mutation rates

OBJECTIVES: Fluoroquinolones have found a place in the management of mycobacterial diseases including tuberculosis. It has been previously shown that subinhibitory concentrations of quinolones increase the mutation rate in Escherichia coli and staphylococci. The purpose of this study is to extend this observation to mycobacteria and to quantify mutation rates. METHODS: The mutation rate in Mycobacterium fortuitum to ciprofloxacin, levofloxacin, moxifloxacin, rifampicin, erythromycin and gentamicin resistance was determined when grown with and without various sub-MIC concentrations of ciprofloxacin. RESULTS: M. fortuitum exposed to 1/2 MIC ciprofloxacin had an increase in the mutation rate of between 72- and 120-fold when selected on quinolones or other antimycobacterial antibiotics. Smaller, but significant increases in mutation rate were seen when the organism was exposed to lower concentrations (1/4 MIC and 1/8 MIC). CONCLUSIONS: These data show that sub-MIC concentrations of fluoroquinolone significantly increase mutation rates and these data suggest that care must be taken to ensure that bacteria are not exposed to subinhibitory concentrations when adding quinolones to a regimen used to treat mycobacterial infection.     

The role of pore size on vascularization and tissue remodeling in PEG hydrogels

Vascularization is influenced by the physical architecture of a biomaterial. The relationship between pore size and vascularization has been examined for hydrophobic polymer foams, but there has been little research on tissue response in porous hydrogels. The goal of this study was to examine the role of pore size on vessel invasion in porous poly(ethylene glycol) (PEG) hydrogels. Vascularized tissue ingrowth was examined using three-dimensional cell culture and rodent models. In culture, all porous gels supported vascular invasion with the rate increasing with pore size. Following subfascial implantation, porous gels rapidly absorbed wound fluid, which promoted tissue ingrowth even in the absence of exogenous growth factors. Pore size influenced neovascularization, within the scaffolds and also the overall tissue response. Cell and vessel invasion into gels with pores 25-50 μm in size was limited to the external surface, while gels with pores larger pores (50-100 and 100-150 μm) permitted mature vascularized tissue formation throughout the entire material volume. A thin layer of inflammatory tissue was present at all PEG-tissue interfaces, effectively reducing the area available for tissue growth. These results show that porous PEG hydrogels can support extensive vascularized tissue formation, but the nature of the response depends on the pore size.     

Icilin-induced wet-dog shakes in rats are dependent on NMDA receptor activation and nitric oxide production

Icilin is a cold channel agonist that produces vigorous wet-dog shaking in rats. The shaking is accompanied by an increase in the level of extracellular glutamate in the brain. Hence, we hypothesized that icilin-induced wet-dog shakes are dependent on increased glutamatergic transmission and nitric oxide (NO) production. Rats injected with icilin (0.5, 1, 2.5, 5 mg/kg, i.p.) displayed a dose-related increase in wet-dog shakes. Pretreatment with LY 235959 (1, 2 mg/kg, i.p.), a NMDA receptor antagonist, or L-NAME (50 mg/kg, i.p.), a NO synthase (NOS) inhibitor, attenuated icilin-induced wet-dog shakes. The shaking was also reduced by intracerebroventricular L-NAME (1 mg/rat, i.c.v.) administration, indicating that the stimulant effect of icilin is dependent on central NO production. Pretreatment with 6,7-dinitroquinoxaline-2,3(1H,4H)-dione (DNQX) (10, 20 mg/kg, i.p.), an AMPA receptor antagonist, or ceftriaxone (200 mg/kg, i.p. for 5 days), a beta-lactam antibiotic and glutamate transporter subtype 1 (GLT-1) activator, did not alter the incidence of icilin-induced shaking. The present data reveal that icilin produces behavioral stimulation by a mechanism requiring NMDA receptor activation and nitric oxide production and suggest that glutamate and NO signaling play important roles in cold channel pharmacology.     

A Comparison of Father and Mother Report of Child Behaviour on the Strengths and Difficulties Questionnaire

To date there has been no comparison of father and mother report on the Strengths and Difficulties Questionnaire (SDQ), a standardised measure of child behaviour used widely in the UK in clinical practice and research. The objectives of the study were to investigate differences and agreement between parents on the various SDQ domains of child behaviour. Parents of 4–6 years olds were recruited via 13 UK general practices, and completed the SDQ and measures on depression, parenting, couple relationship, alcohol use and demographics. Parental SDQ ratings were compared. The SDQ was completed by 248 parent dyads. Mother and father ratings were correlated, however fathers reported higher mean scores than mothers for externalising behaviours. Higher reporting by fathers was related to alcohol misuse, the couple relationship, fathering, and father employment. Fathers did not report significantly more abnormal behaviours than mothers except for hyperactivity. There was high interparental agreement on normal/borderline behaviours (94.8–98.3% agreement), but lower agreement on abnormal behaviours (7.7–37.9%). There was higher interparental agreement on male rather than female children, but fathers were four times more likely to report hyperactivity among their boys compared with girls. Using combined parental reports in clinical settings would enhance the sensitivity of identifying children requiring clinical attention for their problem behaviours.     

Significant differences in alkaloid content of Coptis chinensis (Huanglian), from its related American species

Background  

The growing popularity of Chinese herbal medicine in the United States has prompted large-scale import of raw herbs from Asia. Many of the Asian herbs have phylogenetically related North American species. We compared three phylogenetically related species, namely Coptis chinensis (Huanglian), Hydrastis canadensis and Coptis trifolia to show whether they can be substituted by one another in terms of alkaloid content.     

Somatostatin Receptor SSTR-2a Expression Is a Stronger Predictor for Survival Than Ki-67 in Pancreatic Neuroendocrine Tumors

Somatostatin receptors (SSTR) are commonly expressed by neuroendocrine tumors. Expression of SSTR-2a and SSTR-5 may impact symptomatic management; however, the impact on survival is unclear. The aim of this study is to correlate SSTR-2a and SSTR-5 expression in pancreatic neuroendocrine tumors (PNETs) with survival.This study is designed to determine the prognostic significance of somatostatin receptors SSTR-2a and SSTR-5 in PNETs.This retrospective cohort study included cases of resected PNETs between 1992 and 2014. Clinical data, histopathology, expression of SSTR and Ki-67 by immunohistochemistry, and long-term survival were analyzed.A total of 99 cases were included in this study. The mean age was 57.8 years (18–87 years) and median tumor size was 25 mm (range 8–160 mm). SSTR-2a and SSTR-5 expression was scored as negative (n = 19, 19.2%; n = 75, 75.8%, respectively) and positive (n = 80, 80.1%; n = 24, 24.2%). The median follow-up was 49 months. SSTR-2a expression was associated with improved overall survival, with cumulative survival rates at 1, 3, and 5 years being 97.5%, 91.5%, and 82.9%, respectively. Univariate analysis demonstrated better survival in SSTR-2a positive patients (log rank P = 0.04). SSTR-5 expression was not associated with survival outcomes (log rank P = 0.94). Multivariate analysis showed that positive SSTR-2a expression is a stronger prognostic indicator for overall survival [Hazard Ratio (HR): 0.2, 95% Confidence interval (CI): 0.1–0.8] compared to high Ki-67 (HR: 0.8, 95% CI: 0.1–5.7).Expression of SSTR-2a is an independent positive prognostic factor for survival in PNETs.