Argon plasma coagulation treatment of anal high-grade squamous intraepithelial lesions in men who have sex with men living with HIV: results of a 2-year prospective pilot study.

OBJECTIVES: Men who have sex with men (MSM) living with HIV are at high risk for anal high-grade squamous intraepithelial lesions (HSILs) and cancer. The best management of anal HSIL remains unclear. Our objective was to assess whether argon plasma coagulation (APC) could be safe, well tolerated and efficient to treat anal HSILs in MSM living with HIV. METHODS: A prospective phase II, open-label, pilot study was conducted to evaluate APC to treat anal HSILs in 20 HIV-positive MSM. Participants were followed for 2 years after their first treatment. RESULTS: Twenty men with persistent HSILs completed the 2-year study. Their baseline median CD4 count was 490 cells/µL and 85% had undetectable HIV viral loads. Overall, 65% (13/20) of participants were clear of HSILs at their 24-month visit. The initial response rates after the first, second and third APC treatments were 45%, 44% and 67%, respectively, but recurrences were common. The main side effect was pain during and within 1 week after the treatments. There were no long-term side effects, nor serious adverse events related to the procedure. Cost is a drawback. CONCLUSIONS: APC can be used to treat anal HSILs in HIV-seropositive MSM, and requires repeated treatment because of a high recurrence rate. As successful treatment of human papillomavirus (HPV) infection or eradication of the anal transitional zone remains impossible, HSIL treatment is challenging and requires long-term follow-up.

Differential actinodin1 regulation in zebrafish and mouse appendages.

The fin-to-limb transition is an important evolutionary step in the colonization of land and diversification of all terrestrial vertebrates. We previously identified a gene family in zebrafish, termed actinodin, which codes for structural proteins crucial for the formation of actinotrichia, rigid fibrils of the teleost fin. Interestingly, this gene family is absent from all tetrapod genomes examined to date, suggesting that it was lost during limb evolution. To shed light on the disappearance of this gene family, and the consequences on fin-to-limb transition, we characterized actinodin regulatory elements. Using fluorescent reporters in transgenic zebrafish, we identified tissue-specific cis-acting regulatory elements responsible for actinodin1 (and1) expression in the ectodermal and mesenchymal cell populations of the fins, respectively. Mutagenesis of potential transcription factor binding sites led to the identification of one binding site crucial for and1 expression in ectodermal cells. We show that these regulatory elements are partially functional in mouse limb buds in a tissue-specific manner. Indeed, the zebrafish regulatory elements target expression to the dorsal and ventral ectoderm of mouse limb buds. Absence of expression in the apical ectodermal ridge is observed in both mouse and zebrafish. However, cells of the mouse limb bud mesoderm do not express the transgene, in contrast to zebrafish. Altogether these results hint for a change in regulation of and1 during evolution that led to the downregulation and eventual loss of this gene from tetrapod genomes.

Corticosterone effects on postnatal cerebellar development in mice.

Glucocorticoids administered early in infancy can affect the architectonic organization of brain structures, particularly those with a postnatal development and resulting in long-term deficits of neuromotor function and cognition. The present study was undertaken to study the effects of daily corticosterone (CORT) injections at a pharmacological dose from postnatal days 8-15 on cerebellar and hippocampal development in mouse pups. Gene expression status for trophic factors involved in synaptic development and function as well as measures of layer thickness associated with cytochrome oxidase labelling were analyzed in the hippocampus, hypothalamus, and specific cerebellar lobules involved in motor control. Repeated CORT injections dysregulated the HPA axis with increased Crh and Nr3c1 mRNA levels in the hypothalamus and a resulting higher serum corticosterone level. The CORT treatment altered the morphology of the hippocampus and down-regulated gene transcription for corticotropin-releasing hormone (Crh) and its type-1 receptor (Crhr1), glucocorticoid receptor (Nr3c1), and brain-derived neurotrophic factor Bdnf and its receptor Ntrk2 (neurotrophic receptor tyrosine kinase 2). Similar mRNA expression decreases were found in the cerebellum for Crhr1, Crhr2, Nr3c1, and Grid2 (glutamatergic δ2 receptor). Morphological alterations and metabolic activity variations were observed in specific cerebellar lobules involved in motor control. The paramedian lobule, normally characterized by mitotic activity in the external germinative layer during the second postnatal week, was atrophic but metabolically hyperactive in its granule cell and molecular layers. On the contrary, lobules with an earlier cell proliferation displayed neurogenesis but a hypoactivated granule cell layer, suggesting a developmental delay in synaptogenesis. The results indicate that glucocorticoid, administered daily during the second postnatal week modulated the developmental programming of the hippocampus and cerebellum. These growth and metabolic alterations may lead possibly to morphological and functional changes later in life.

Computerized testing augments pencil-and-paper tasks in measuring HIV-associated mild cognitive impairment(*).

BACKGROUND: Existing tools for rapid cognitive assessment in HIV-positive individuals with mild cognitive deficits lack sensitivity or do not meet psychometric requirements for tracking changes in cognitive ability over time. METHODS: Seventy-five nondemented HIV-positive patients were evaluated with the Montreal Cognitive Assessment (MoCA), a brief battery of standardized neuropsychological tests, and computerized tasks evaluating frontal-executive function and processing speed. Rasch analyses were applied to the MoCA data set and subsequently to the full set of data from all tests. RESULTS: The MoCA was found to adequately measure cognitive ability as a single, global construct in this HIV-positive cohort, although it showed poorer precision for measuring patients of higher ability. Combining the additional tests with the MoCA resulted in a battery with better psychometric properties that also better targeted the range of abilities in this cohort. CONCLUSION: This application of modern test development techniques shows a path towards a quick, quantitative, global approach to cognitive assessment with promise both for initial detection and for longitudinal follow-up of cognitive impairment in patients with HIV infection.

Treatment durability, effectiveness, and safety with atazanavir/ritonavir-based HAART regimen in treatment-naïve HIV-infected patients.

PURPOSE: To describe the durability of treatment, virological and immunological response, and safety of an atazanavir/ritonavir (ATV/RTV)-based highly active antiretroviral therapy (HAART) regimen in treatment-naïve HIV-infected patients. METHODS: This was a multicentre retrospective study. Medical charts of antiretroviral-na'i've HIV-infected adults who initiated ATV/RTV (300/100 mg) from January 2004 to December 2007 in 10 Canadian clinics were reviewed. Data were collected from time of ATV/RTV treatment initiation until discontinuation of ATV. Durability of treatment and time to virological response were estimated with Kaplan-Meier functions. Change in viral load, CD4 cell counts, and lipid parameters were assessed with linear regression analyses. RESULTS: 176 patients were enrolled, 153 (86.9%) were male, and the majority (52.3%) were 40 to 54 years old. Duration of observation ranged from 1.6 to 56 months. The mean (SE) durability of treatment was 33.5 (0.7) months. There were 37 (21.0%) patients who discontinued ATV/ RTV, among whom 18 (10.2%) discontinued due to toxicity, suboptimal virological response, loss to follow-up, or death. The mean (SE) time to HIV viral load of <50 and <400 copies/mL was 6.6 (0.4) and 4.3 (0.3) months, respectively. At 96 weeks of treatment, least squares mean (LSM) estimated change in log10(HIV copies/mL) was -2.94 (P < .001) and +245 cells/mL (P < .001) for CD4 cell count. A significant LSM increase in HDL-C of 0.24 mmol/L (P = .007 for trend over time) was also observed; total cholesterol, triglycerides, and LDL-C increased over time but their change did not reach statistical significance. The most frequently reported adverse event was increased bilirubin (16.5%). CONCLUSIONS: ATV/RTV-based first-line HAART regimen demonstrated durability and effectiveness and was well tolerated in treatment-naïve HIV-infected patients.

Successful implementation of a national HLA-B*5701 genetic testing service in Canada.

Abacavir is a nucleoside reverse transcriptase inhibitor (NRTI) that is used in combination antiretroviral therapy in HIV-infected patients. It is currently recommended as a preferred or an alternative NRTI in antiretroviral-naïve patients. The major toxicity of abacavir is a hypersensitivity reaction (HSR), which occurs in approximately 5% of treated patients. There is a strong association between the human leukocyte antigen (HLA)-B*5701 allele and abacavir HSR, which has allowed for rapid acceptance of genetic screening for HLA-B*5701 in clinical use. Canadian clinicians working in hospital centers with HLA typing capacity opted to launch a pilot project in 2006 to offer the screening test as standard of care to HIV-infected patients. Currently, more than 11,000 HLA-B*5701 tests have been performed, among which 6.3% are positive. Continued efforts have been made to ensure that testing is available to all HIV-infected patients to widen the patients' therapeutic options. HLA-B*5701 screening shows clinical use and preliminary data suggest cost-effectiveness.

Regional brain evaluation of acetylcholinesterase activity in PS1/A246E transgenic mice.

Human presenilin-1 (PS1) mutations are a major cause of autosomal dominant Alzheimer's disease. Forebrain cholinergic innervation was estimated in transgenic mice with the A246E mutation by measuring the activity of the non-specific catabolic enzyme, acetylcholinesterase (AChE). In the model, Abeta(42) concentrations increase without neuritic plaques or cell degeneration. PS1/A246E transgenic mice had altered AChE activity in several regions also vulnerable in Alzheimer pathology. In particular, AChE activity was upregulated in major cholinergic cell nuclei (medial septum, vertical diagonal band, substantia inominata) and in cortical and thalamic regions (eye field, posterior parietal and visual cortices, posterior thalamic and lateral geniculate nuclei) responsible for selective attention and visuomotor coordination, as well as limbic structures (hippocampal formation and amygdala) with related regions (midline, periventricular, reticular thalamic nuclei, and lateral prefrontal, agranular insular cortices) involved in cognition, arousal, emotion, and plasticity. As the murine model caused no apparent learning defects, cholinergic network changes in forebrain seem to be an early event caused by soluble Abeta peptides. PS1/A246E mice mimic to some extent pre-symptomatic Alzheimer's disease neuropathology, useful for studying early neurochemical changes often inaccessible in clinical studies.

Brain regions and genes affecting postural control.

Postural control is integrated in all facets of motor commands. The role of cortico-subcortical pathways underlying postural control, including cerebellum and its afferents (climbing, mossy, and noradrenergic fibers), basal ganglia, motor thalamus, and parieto-frontal neocortex has been identified in animal models, notably through the brain lesion technique in rats and in mice with spontaneous and induced mutations. These studies are complemented by analyses of the factors underlying postural deficiencies in patients with cerebellar atrophy. With the gene deletion technique in mice, specific genes expressed in cerebellum encoding glutamate receptors (Grid2 and Grm1) and other molecules (Prkcc, Cntn6, Klf9, Syt4, and En2) have also been shown to affect postural control. In addition, transgenic mouse models of the synucleinopathies and of Huntington's disease cause deficiencies of motor coordination resembling those of patients with basal ganglia damage.

Discrimination learning in Rora(sg) and Grid2(ho) mutant mice.

Rora(sg) mutants with mild cerebellar granule cell degeneration were compared to Grid2(ho) mutants with more severe granule cell degeneration as well as Purkinle cell atrophy for left-right and dark-light discrimination learning tasks in a water-filled T-maze. The acquisition rate of both cerebellar mutants was slowed down during light-dark but not left-right discrimination learning. However, the mutants were impaired in reversal training in both tasks. In contrast, neither mutant differed from controls in passive avoidance learning. These results indicate that mice with cerebellar damage are affected in some instrumental learning tasks and have perseverative tendencies.

Relations between open-field, elevated plus-maze, and emergence tests as displayed by C57/BL6J and BALB/c mice.

The relations between open-field, elevated plus-maze, and emergence tests were examined in two strains of mice. In the open-field, C57BL/6J mice had more ambulatory movements and rears but not stereotyped movements relative to BALB/c. In addition, C57BL/6J mice entered more often than BALB/c into enclosed and open arms of the elevated plus-maze. When placed inside a large enclosure, C57BL/6J mice emerged more quickly than BALB/c from a small toy object. In the entire series of mice, ambulation and rears in the open-field were linearly correlated with open and enclosed arm visits in the elevated plus-maze. Ambulatory movements and rears were also correlated with emergence latencies. In contrast, stereotyped movements were correlated with emergence latencies, but not with any elevated plus-maze value. These results specify the extent and limits of association between the three tests.

Effects of a B-vitamin-deficient diet on exploratory activity, motor coordination, and spatial learning in young adult Balb/c mice.

Elevated homocysteine levels resulting from vitamin B deficiencies have been hypothesized to contribute to functional decline. To investigate the effects of elevated serum homocysteine on neurobehavioral performances, young adult Balb/c mice consumed a vitamin-B-deficient diet or a control diet under free-feeding and pair-fed conditions. The B-deficient diet decreased body weight and food intake but increased water ingestion. Relative to either control group, vitamin-B-deficient mice were more active in the open field and in enclosed arms of the elevated plus-maze. However, vitamin-B-deficient mice were not impaired on sensorimotor coordination and spatial learning tests, swimming to a visible platform even faster than either control group. The main effect of this diet restriction was hyperactivity with no change in anxiety, coordination, and memory. It remains to be determined whether severer deficits are demonstrable in older mice.

Sensitivity of N170 and late positive components to social categorization and emotional valence.

Previous experiments have shown that categorization of people into two distinct fictive groups has an impact on cognitive processes. The main objective of the present study was to examine whether this mere categorization improves information processing speed and alters early and late onset ERPs during a social judgment task. In a group membership situation, in-group evaluation enhanced information processing speed and occipito-temporal N170 amplitudes, associated with orthographic processing, compared to out-group evaluation, more so for positive than negative attributes. Moreover, negative adjectives elicited larger N170 amplitudes and faster information processing speed than positive adjectives. In contrast, positive adjectives in a non-membership context enhanced a late positive component in prefrontal regions. These results reflect the existence of a motivational top-down influence due to social categorization in early perceptual stages of word processing. These findings are also in accord with the existence of two distinct systems of evaluation, the first implicating an automatic processing represented in occipito-temporal neocortex and the other a more controlled processing represented in PFC.

Nontraditional approaches to first-in-human studies to increase efficiency of drug development: will microdose studies make a significant impact?

Much has been written recently about low productivity in the pharmaceutical industry and the high cost of drug development. Over a 10-year period ending in 2000, only approximately 11% of compounds tested in humans across 10 large pharmaceutical companies were eventually approved for marketing in the United States and/or Europe. Attrition was highest during phase II (62%) but still significant in phase III (45%) and at the time of registration (23%). Clearly, given the high cost and time required for clinical development, these late-stage failures are unsustainable.

Model-based drug development.

The low productivity and escalating costs of drug development have been well documented over the past several years. Less than 10% of new compounds that enter clinical trials ultimately make it to the market, and many more fail in the preclinical stages of development. These challenges in the "critical path" of drug development are discussed in a 2004 publication by the US Food and Drug Administration. The document emphasizes new tools and various opportunities to improve drug development. One of the opportunities recommended is the application of "model-based drug development (MBDD)." This paper discusses what constitutes the key elements of MBDD and how these elements should fit together to inform drug development strategy and decision-making.

Role of iron in Trypanosoma cruzi infection of mice.

The role of iron in experimental infection of mice with Trypanosoma cruzi was investigated. B6 mice had a transient parasitemia and a transient anemia, both of maximal intensity 28 d after the inoculation of T. cruzi. There was a biphasic hypoferremic host response to infection with T. cruzi with the peak hypoferremia also occurring 28 d after inoculation of the parasite. The mortality rate from infection was increased from 23% in phosphate-buffered saline-treated B6 mice to 50% in a group of B6 mice receiving iron-dextran (P less than or equal to 0.025), whereas depletion of iron stores with the iron chelator desferrioxamine B and an iron-deficient diet provided complete protection of B6 mice (P less than or equal to 0.05). The mortality rate in the highly susceptible C3H strain was reduced from 100% in the control group to 45% (P less than or equal to 0.025) in the iron-depleted group. The tissue iron stores were altered in mice receiving either iron-dextran or desferrioxamine B and an iron-deficient diet. In vitro, T. cruzi was shown to require both a heme and a nonheme iron source for an optimal growth rate. The effects of iron excess or depletion on the outcome of infection with T. cruzi correlated both with the growth requirements of the parasite for iron and with the availability of intracellular iron. Thus, it was suggested that the hypoferremic response, by sequestering iron within intracellular stores, potentially enhanced the pathogenicity of the intracellular parasites. Furthermore, the in vivo effects of iron excess and depletion correlated with an effect of iron on the growth rate and pathogenicity of the parasite.

Regional variations of cytochrome oxidase activity in the central auditory system of Relnrl-Orl (reeler) mutant mice.

Despite preserved cell differentiation, the Reln(rl-Orl) phenotype comprises laminar abnormalities of cell position in auditory cortex and dorsal cochlear nucleus. The metabolic consequences of the cell ectopias were determined by estimating cytochrome oxidase (CO) activity, a marker of neuronal activity. CO activity increased in the granular cell layer of dorsal cochlear nucleus, trapezoid body nucleus, intermediate lateral lemniscus, central and external inferior colliculus, and pyramidal cell layer of primary auditory cortex. On the contrary, CO activity decreased in the superficial molecular layer of dorsal cochlear nucleus as well as in the medioventral periolivary nucleus. These metabolic variations are discussed in terms of their possible relation to morphologic anomalies observed in the mutant.

Exploratory activity, motor coordination, and spatial learning in Mchr1 knockout mice.

Male mice with a null mutation of Mchr1, encoding melanin concentrating hormone receptor-1, were compared to wild-type on two background strains. Mchr1 knockout (KO) mice were more active than 129/SvEv and C57BL/6J wild-type strains in a photocell actimeter. In addition, Mchr1 KO mice on the C57BL/6J background were less anxious in the elevated plus-maze, while on the 129/SvEv background, the mutants were less emotionally reactive as estimated by fecal boli and handling-related vocalization. There was no detrimental impact of the null mutation on motor coordination and spatial learning. Mchr1 KO mice had shorter latencies before reaching the escape platform, but only on the 129/SvEv background. Null mutants were lighter than C57BL/6J controls but heavier than 129/SvEv controls, attributable to interactions with strain-dependent genes.

Spontaneous and induced mouse mutations with cerebellar dysfunctions: behavior and neurochemistry.

Grid2(Lc) (Lurcher), Grid2(ho) (hot-foot), Rora(sg) (staggerer), nr (nervous), Agtpbp1(pcd) (Purkinje cell degeneration), Reln(rl) (reeler), and Girk2(Wv) (Weaver) are spontaneous mutations with cerebellar atrophy, ataxia, and deficits in motor coordination tasks requiring balance and equilibrium. In addition to these signs, the Dst(dt) (dystonia musculorum) spinocerebellar mutant displays dystonic postures and crawling. More recently, transgenic models with human spinocerebellar ataxia mutations and alterations in calcium homeostasis have been shown to exhibit cerebellar anomalies and motor coordination deficits. We describe neurochemical characteristics of these mutants with respect to regional brain metabolism as well as amino acid and biogenic amine concentrations, uptake sites, and receptors.

Chaotic dynamics can select for long-term dormancy.

Extended dormancy in a population is evolutionarily costly unless some variance in season-to-season fitness (usually driven by variance in environmental quality) makes bet hedging useful. Consequently, dormancy in a population is usually accepted as evidence of environmental variance. Using a Ricker-type model with heritable variation in dormancy, we show that this need not be so. Intrinsic population dynamics can generate chaotic fluctuations in the absence of environmental variance. Chaotic dynamics increase the frequency of a range of dormant strategists under natural selection, even when mortality during dormancy is relatively high. The buffering effect of dormant individuals then eliminates chaotic dynamics or generates periodic orbits of relatively low amplitude. These stabilized populations harbor a high frequency of dormant individuals that express a range of propensities to enter dormancy.

Regional brain variations of cytochrome oxidase activity and motor coordination in Girk2(Wv) (Weaver) mutant mice.

The Girk2(Wv) (weaver) phenotype, caused by a mutated inward rectifying potassium channel, is characterized by degeneration of cerebellar granule cell population as well as midbrain dopamine-containing cells of the nigrostriatal pathway. To investigate the regional brain metabolic consequences of this combined pathology, cytochrome oxidase (CO) activity was measured by histochemistry from brain regions of wild-type and homozygous Girk2(Wv) mutant mice and correlated with motor performances. CO activity of Girk2(Wv) mutants was abnormal in cerebellar cortex, dentate nucleus, and brainstem regions (medial and lateral vestibular nuclei, prepositus, superior colliculus, lateral cuneiform nucleus, and reticular nuclei) implicated in the gaze system. CO activity increased in midbrain dopaminergic regions after correcting for tissue density, regions with severe depletion of tyrosine hydroxylase activity. Forebrain regions were relatively spared in term of CO activity, except for subthalamic nucleus, lateral geniculate nucleus, and cortical eye field. Similarly to the Rora(sg) cerebellar mutant, metabolic alterations in cerebellar and vestibular regions were linearly correlated with poor motor coordination, underlining the sensitivity of these tests to cerebellar dysfunction.