Minocycline attenuates mechanical allodynia and proinflammatory cytokine expression in rat models of pain facilitation

Activated glial cells (microglia and astroglia) in the spinal cord play a major role in mediating enhanced pain states by releasing proinflammatory cytokines and other substances thought to facilitate pain transmission. In the present study, we report that intrathecal administration of minocycline, a selective inhibitor of microglial cell activation, inhibits low threshold mechanical allodynia, as measured by the von Frey test, in two models of pain facilitation. In a rat model of neuropathic pain induced by sciatic nerve inflammation (sciatic inflammatory neuropathy, SIN), minocycline delayed the induction of allodynia in both acute and persistent paradigms. Moreover, minocycline was able to attenuate established SIN-induced allodynia 1 day, but not 1 week later, suggesting a limited role of microglial activation in more perseverative pain states. Our data are consistent with a crucial role for microglial cells in initiating, rather than maintaining, enhanced pain responses. In a model of spinal immune activation by intrathecal HIV-1 gp120, we show that the anti-allodynic effects of minocycline are associated with decreased microglial activation, attenuated mRNA expression of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), IL-1beta-converting enzyme, TNF-alpha-converting enzyme, IL-1 receptor antagonist and IL-10 in lumbar dorsal spinal cord, and reduced IL-1beta and TNF-alpha levels in the CSF. In contrast, no significant effects of minocycline were observed on gp120-induced IL-6 and cyclooxygenase-2 expression in spinal cord or CSF IL-6 levels. Taken together these data highlight the importance of microglial activation in the development of exaggerated pain states.     

Effect of sperm concentration, medium osmolality and oocyte storage on artificial fertilisation success in a myobatrachid frog (Limnodynastes tasmaniensis)

The present study optimised artificial fertilisation and oocyte storage conditions in Limnodynastes tasmaniensis (Myobatrachidae). Data on general reproductive biology, the effect of sperm motility and concentration, medium osmolality and oocyte storage on artificial fertilisation success are presented. Egg number was most strongly correlated with bodyweight (r = 0.819). Sperm yield was correlated with testes weight (r = 0.827), which was strongly correlated with snout-vent length (r = 0.772). Optimal artificial fertilisation occurred in 0-7 mOsm kg(-1) amphibian Ringer, similar to ranid, bufonid and hylid species. High fertilisation rates were achieved using spermatozoa with little forwards progressive motility at comparatively low concentrations (3 x10(4) sperm cells mL(-1)) and with no relationship between percentage sperm motility and fertilisation success (correlation of fertilisation rate with sperm motility after activation: r = -0.145). Oocytes stored in 5 mOsm kg(-1) solutions showed no significant decline in fertilisability after 2 h, showing that swelling of the jelly surrounding the eggs does not prevent sperm from fusing with the oocyte in this species. Fertilisability of oocytes was extended to > 4 h in medium to high osmolality solutions (124-271 mOsm kg(-1)). These data allow for the future use of L. tasmaniensis in developing assisted reproductive technology protocols for foam-nesting myobatrachid species, many of which are now threatened with extinction in the wild.     

Normative data from the CANTAB. I: development of executive function over the lifespan

The study of executive function within a developmental framework has proven integral to the advancement of knowledge concerning the acquisition and decline of higher skill processes. Still in its early stages, there exists a discontinuity in the literature between the exploration of executive capacity in young children and the elderly. Research of age-related differences utilising a lifespan approach has been restricted by the lack of assessment tools for the measurement of executive skills that are applicable across all age levels. This paper addresses these issues using the computer-based Cambridge Neuropsychological Test Automated Battery (CANTAB) to identify periods of development in executive capacities using a normative sample of 194 participants ranging in age from 8 to 64 years. Findings of executive function in children as young as 8 years of age were extended, with functional gains found in the efficiency of working memory capacity, planning and problem-solving abilities, between the ages of 15 and 19 years and again at 20-29 years of age. Cognitive flexibility was assessed at adult-levels in even the youngest children. Declines in performance on all tasks were revealed for the 50-64 year old sample, providing support for the vulnerability of executive skills to normal aging.     

Impact of urine collection order on the ability of assays to identify Chlamydia trachomatis infections in men

BACKGROUND: Noninvasive urine samples have been used to diagnose Chlamydia trachomatis infections, with the assumption that the first-void urine (FVU), defined as the first 20 to 30 ml at any micturition, would be the optimal collection. We compared testing technologies on first, second, and third volumes for diagnosis. GOAL: The goal was to test in nonculture assays three sequential volumes of urine from men also undergoing urethral swabbing for C trachomatis culture specimens. STUDY DESIGN: A total of 237 men attending an STD clinic (C trachomatis prevalence, 11%) collected three containers of urine (each containing 20-30 mL) for testing in four nonculture assays. A urethral swab specimen was tested in cell culture. RESULTS: The numbers of men positive by testing of FVU with nucleic acid amplification (LCx chlamydia), nucleic acid hybridization (PACE 2), enzyme immunoassay (Chlamydiazyme), and a leukocyte esterase dipstick were 26, 7, 14, and 11, respectively; urethral culture identified 6 of the infected men. Comparative testing of all voids from the 26 men positive by the FVU assays demonstrated a reduction of LCx-positives. Non-amplified-test positivity declined precipitously in subsequent voids, approaching zero in the third void. The presence of symptoms and time of last void up to 8 hours had little effect on the number of positives detected by LCx of FVU. CONCLUSION: Amplified testing of FVU was most effective for diagnosing infection in these men.     

Membrane permeation characteristics of abacavir in human erythrocytes and human T-lymphoblastoid CD4+ CEM cells: comparison with (-)-carbovir

Abacavir, (-)-(1S,4R)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclopentene-1-methanol, is a novel purine carbocyclic nucleoside analogue that has been approved by the FDA for the treatment of HIV (as Ziagen trade mark [abacavir sulfate]). Chemically, abacavir and (-)-carbovir (CBV) differ only at the 6-position of the purine ring; abacavir contains a cyclopropylamino moiety in place of the 6-lactam functionality of CBV. Intracellularly both are ultimately metabolized to CBV triphosphate. We compared the membrane permeation characteristics of these two compounds at 20 degrees C in human erythrocytes and in human T-lymphoblastoid CD4+ CEM cells, using a "papaverine-stop" assay. In erythrocytes, abacavir influx was rapid, nonsaturable (rate constant=200 pmol/s/mM/microl cell water), and unaffected by inhibitors of nucleoside or nucleobase transport. CBV influx was slow, saturable, strongly inhibited by adenine or hypoxanthine, and occurred via both the nucleobase carrier (Vmax=0.67 pmol/s/microl cell water; Km=50 microM) and the nucleoside carrier (Vmax=0.47 pmol/s/microl cell water; Km=440 microM). Similar qualitative results were obtained with CD4+ CEM cells, although CBV influx rates were somewhat higher and abacavir influx rates lower, compared to the corresponding rates in erythrocytes. Equilibrium studies further revealed that both compounds are concentrated intracellularly, but nonmetabolically, in both cell types, apparently due to cytosolic protein binding (absent in erythrocyte ghosts). We conclude that, in both cell types, while CBV influx is slow and carrier-dependent, abacavir influx occurs rapidly by nonfacilitated diffusion. The membrane permeation characteristics of abacavir are consistent with its superior oral bioavailability and its impressive ability to penetrate the central nervous system.     

Studies of enuresis. V. Classification of enuresis and the juvenile urinary incontinence syndrome

Urinary incontinence is a common disorder of childhood and varies in severity through a broad spectrum from occasional nocturnal enuresis to severe daytime wetting. Eight to 10 per cent of all otherwise normal children are affected to some degree. Treatment of the juvenile incontinence syndrome has been approached from a variety of directions, often empirically, and with variable success. This classification of incontinence in children is described with the hope that it will be adopted by investigators and clinicians to describe and quantitate more specifically the nature of their treatment groups and more objectively assess the results of treatment programs. The potential value of such a classification in documentation, communication, and comparison of data is apparent.