Detection of in vivo hepatitis B virus surface antigen mutations-A comparison of four routine screening assays.

An important requirement for a state-of-the-art hepatitis B surface antigen (HBsAg) screening assay is reliable detection of mutated HBsAg. Currently, there is a striking shortage of data regarding the detection rates of in vivo HBsAg mutations for these clinically important assays. Therefore, we compared the detection rates of four commercial HBsAg screening assays using a global cohort of 1553 patients from four continents with known HBV genotypes. These samples, which represent the broadest spectrum of known and novel HBsAg major hydrophilic region (MHR) mutations to date, were analyzed for the presence of HBsAg using the Roche Elecsys® HBsAg II Qualitative, Siemens ADVIA Centaur XP HBsAg II, Abbott Architect HBsAg Qualitative II and DiaSorin Liaison® HBsAg Qualitative assays, respectively. Of the 1553 samples, 1391 samples could be sequenced; of these, 1013 (72.8%) carried at least one of the 345 currently known amino acid substitutions (distinct HBsAg mutation) in the HBsAg MHR. All 1553 patient samples were positive for HBsAg using the Elecsys® HBsAg II Qual assay, with a sensitivity (95% confidence interval) of 99.94% (99.64%-100%), followed by the Abbott Architect 99.81% (99.44%-99.96%), Siemens ADVIA 99.81% (99.44%-99.96%) and DiaSorin Liaison® 99.36% (98.82%-99.69%) assays, respectively. Our results indicate that the Elecsys® HBsAg II Qual assay exhibits the highest sensitivity among the commercial HBsAg screening assays, and demonstrate that its capacity to detect HBV infection is not compromised by HBsAg MHR mutants.

Analysis of the PKR-eIF2alpha phosphorylation homology domain (PePHD) of hepatitis C virus genotype 1 in HIV-coinfected patients by ultra-deep pyrosequencing and its relationship to responses to pegylated interferon-ribavirin treatment.

Chronic coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) is among the greatest challenges facing public health worldwide. In this population, the response to hepatitis C therapy by treatment with pegylated interferon plus ribavirin (PEG-IFN+RBV) is lower than in HCV-monoinfected patients, particularly in those infected by HCV genotype 1. A PKR/eIF-2α phosphorylation homology domain (PePHD) within the E2 protein has been found to interact with PKR and inhibit PKR in vitro, suggesting a possible mechanism for HCV to evade the antiviral effects of IFN. The aim of this work was to analyze the amino acid conservation in the HCV-E2-PePHD and quasispecies diversity among HCV-HIV-coinfected patients exhibiting sustained virological response, non-response, or partial response with viral relapse to PEG-IFN+RBV by ultra-deep pyrosequencing. For this purpose, HCV-E2-PePHD PCR products were generated and sequenced directly for four patients with a sustained response, seven patients with no virological response, and four patients with viral relapse before and after treatment with PEG-IFN+RBV. HCV-E2-PePHD amino acid sequences were obtained for isolates from serum collected before and during treatment (24 h, 4 weeks, and 12 weeks). Quasispecies analysis of the HCV-E2-PePHD and flanking genomic regions was performed using 454/Roche pyrosequencing, analyzing 39,364 sequence reads in total. The HCV-E2-PePHD sequence at the amino acid and nucleotide level was highly conserved among HCV genotype 1 strains, irrespective of the PEG-IFN+RBV response. This high degree of amino acid conservation and sporadic mutations in the HCV-E2-PePHD domain do not appear to be associated with treatment outcome. The HCV-E2-PePHD sequence before or during treatment cannot be used to predict reliably the outcome of treatment in patients coinfected with HCV genotype 1 and HIV.

A comparative study of aimed throwing by monkeys and humans.

This research examined hand preference and postural characteristics of aimed throwing in capuchin monkeys and humans. We sought to directly compare the throwing performances of these primates, particularly the extent to which target distance influences hand preference, throwing posture, and throwing accuracy. For both species we found positive correlations between target distances for throwing accuracy, direction and strength of hand preference, percentage of bipedal vs tripedal throws, and percentage of overarm vs underarm throws. Throwing accuracy did not vary as a function of right vs left hand use although for monkeys throwing accuracy was positively associated with hand preference strength. We noted a sex difference among humans as males threw more accurately than did females. Between-species analysis indicated that humans exhibited greater right- vs left-hand use, greater hand preference strength, a greater relative percentage of bipedal vs tripedal throws, and a lower relative percentage of overarm vs underarm throws than did monkeys. We believe that the capuchin monkey is an informative nonhuman primate model of aimed throwing in humans and that research examining the throwing behavior of capuchins provides insight into the neurological and behavioral characteristics that underlie coordinated multi-joint movements across the primate order.

Between-species variation in the development of hand preference among macaques.

This research examined between-species variation in the development of hand preference among Macaca. Specifically, we examined hand preference using juveniles and adults of three macaque species that differ in social and reactive tendencies in order to examine whether the correlation between temperament and handedness that has been noted within Macaca mulatta occurs between closely related species. Each of the species studied exhibited a different pattern of hand preference development. Both juvenile and adult M. mulatta exhibited group-level left-hand bias. Juvenile Macaca nemestrina were not biased towards either hand at the group-level, whereas adults exhibited a group-level left-hand bias. Neither juvenile nor adult Macaca fascicularis exhibited manual bias at the group-level. Analysis of variance indicated statistically significant main effects of species and age class on hand preference measures. Post-hoc analysis indicated greater use of the left- versus right-hand, and greater hand preference strength independent of direction, among M. mulatta and M. nemestrina than among M. fascicularis, and among adults than among juveniles. These results indicate significant between-species variation in the development of hand preference within the genus Macaca, and are inconsistent with any one single-factor theory yet offered to explain the etiology of primate laterality. We hypothesize that the relationship between handedness and temperament that has been shown within M. mulatta may generalize across closely related primate species.

Hormonal correlates of hand preference in free-ranging primates.

In this research we examined hormonal correlates of hand preference in free-ranging primates. Specifically, we tested the hypothesis that levels of the stress hormone cortisol and the male sex hormone testosterone are correlated with handedness in male rhesus macaques (Macaca mulatta). We found significant positive relationships between cortisol and testosterone levels sampled during adolescence and the frequency of right- versus left-hand use sampled during adulthood. These data indicate that adolescent measures of cortisol and testosterone are correlated with hemispheric specialization in adult free-ranging primates.

CSF 5-HIAA and nighttime activity in free-ranging primates.

Men with low CNS serotonin turnover, as measured by cerebrospinal fluid 5-hydroxyindoleacetic acid (CSF 5-HIAA) concentrations, exhibit aberrant circadian activity patterns characterized by disrupted sleep rhythms and daytime hyperactivity. To assess whether similar patterns are found in nonhuman primates we examined the relationships between CSF 5-HIAA and nighttime activity in free-ranging monkeys. CSF samples were obtained from 16 adult male rhesus macaques living on a 475 acre, heavily forested sea island. Each subject was captured, fitted with a radio-telemetry motion-detector collar, and then released back into its group. A receiver placed near the sleeping trees of the study subjects recorded activity between 2100 hrs and 0600 hrs. Trained observers recorded behavioral data during the day. The animals followed a typical diurnal activity pattern, as they were active 74% of the sampled time during the day and 37% of the sampled time during the night. CSF 5-HIAA concentrations were inversely correlated with total duration of nighttime activity as well as mean duration of all active events. Nighttime activity was inversely correlated with daytime activity. CSF 3-methoxy-hydroxyphenylglycol (MHPG) concentrations were positively correlated with total nighttime activity, and inversely correlated with daytime sleep frequency. We conclude that male rhesus with low CSF 5-HIAA concentrations have higher total nighttime activity, longer mean periods of nighttime activity, and sleep more during the day than do males with high CSF 5-HIAA concentrations. This suggests that low serotonergic neurotransmission is associated with aberrant diurnal activity, as evidenced by a disruption of nighttime sleep patterns and a compensatory higher rate of inactivity during the day.

CSF 5-HIAA and aggression in female macaque monkeys: species and interindividual differences.

RATIONALE: While the relationship among CSF 5-HIAA, impulsivity, and aggression is well characterized in males, its investigation in females is limited, and no studies have assessed its generalizability across primates by making simultaneous comparisons between and within closely-related species. OBJECTIVES: We tested three hypotheses. First, that female rhesus macaques would have lower CSF 5-HIAA concentrations and be more aggressive than would female pigtailed macaques. Second, that females of both macaque species would exhibit an inverse relationship between interindividual differences in CSF 5-HIAA concentrations and rates of severe aggression. Third, that subjects with high CSF 5-HIAA concentrations would be higher in social dominance within their respective groups than would subjects with low CSF 5-HIAA concentrations. METHODS: We obtained CSF samples from 61 individually housed female primates of two closely related species: rhesus macaques (Macaca mulatta) and pigtailed macaques (Macaca nemestrina). We later placed subjects in unisex social groups, and correlated interindividual differences in CSF 5-HIAA with aggression, wounding, and acquisition of social dominance rank. RESULTS: Between-species analyses indicated higher CSF 5-HIAA concentrations in pigtailed macaques, and higher rates of high-intensity aggression, escalated aggression, and wounds requiring medical treatment in rhesus macaques. Within-species analyses indicated that interindividual differences in CSF 5-HIAA concentrations were inversely correlated with escalated aggression and positively correlated with social dominance rank. CONCLUSIONS: These findings show that agonistic and social differences between closely-related species are correlated with CNS serotonin activity, as species that show relatively high rates of severe aggression also tend to have low concentrations of CSF 5-HIAA. We conclude that serotonergic functioning plays an important role in controlling impulses that regulate severe aggression and social dominance relationships in both male and female primates, and that between-species differences in agonistic temperament can be predicted by species typical CNS serotonin functioning.

Familial influences on hand preference: genotypic variation between closely related primate species.

The emergence of hemispheric specialization has important implications for the development of higher order cognitive processes, including language and spatial skills. In this research we sought to further understand psychobiological processes associated with the development of hemispheric specialization by examining and comparing familial influences on hand preference in two closely related macaque species: rhesus macaques (Macaca mulatta) and pigtailed macaques (Macaca nemestrina). The results of our study indicate contrasting patterns of familial influence on hand preference in each species. For the rhesus macaque we found a positive correlation in the direction of hand preference between mothers and their juvenile offspring, and for the pigtailed macaque we found a negative mother-offspring correlation in the direction of hand preference. Fathers did not contribute significantly to the direction of hand preference in either species. There was a trend toward a positive correlation for strength and consistency of hand preference between parents and offspring in rhesus macaques but not in pigtailed macaques. These findings indicate that maternal influences on offspring hand preference vary between closely related primate species and lead us to question the generalizability of universal single-factor theories used to explain intergenerational transmission of hand preference in humans.

Object manipulation and the use of tools by infant baboons (Papio cynocephalus anubis).

Infant baboons (Papio cynocephalus anubis) in a captive peer group used objects as containers, drinking utensils, and sponges in the context of play. The baboons later used paper, browse, and other materials as tools to extract sweet liquids from apparatus designed to accommodate sponging and probing behavior. The results of this study demonstrate flexible combinatorial manipulation and spontaneous use of tools by infant baboons. These data are consistent with hypotheses that (a) an evolutionary history of omnivorous extractive foraging is associated with the use of tools and (b) free play in an object-enriched captive environment may facilitate combinatorial manipulation in nonhuman primates.

Hand preference in the use and manufacture of tools by tufted capuchin (Cebus apella) and lion-tailed macaque (Macaca silenus) monkeys.

The purpose of this study was to examine hand preference in the use and manufacture of probing tools by tufted capuchin and lion-tailed macaque monkeys (Cebus apella and Macaca silenus). Hand preference for the tool-using sequence was noted in 4 of 5 capuchins (a left-hand preference was noted in 3 ss) and 3 of 4 macaques (a left-hand preference was noted in 2 ss). The monkeys frequently used bimanual action in the initial and final segments of the 3-component task and typically modified tools through coordinated action of the hands and teeth. These data provide evidence consistent with the hypotheses that (a) hemisphere specialization for manual control evolved in primates prior to intensive use of tools by early hominids and (b) monkeys prefer the left hand for precise, visually guided, manipulative actions.

Development of combinatorial manipulation in infant baboons (Papio cynocephalus anubis).

Infant baboons (Papio cynocephalus anubis) housed in individual cages combined objects and used tools in play and food acquisition. The baboons first combined objects at age 2 months, placed objects inside a container at age 4 months, and repeatedly used paper towels as sponges at age 6 months. The results of this investigation demonstrate that infant baboons develop extensive manipulative propensities during the first postnatal semester. These data are consistent with hypotheses that (a) creative recombination facilitates the acquisition of novel behavior patterns and (b) the development of combinatorial manipulation in baboons parallels the development of analogous abilities in human infants.

Lion-tailed macaques (Macaca silenus) manufacture and use tools.

Lion-tailed macaques (Macaca silenus) in captive social groups spontaneously manufactured and used tools to extract syrup from an apparatus that was designed to accommodate probing behavior. An attempt to replicate these findings with mandrills (Mandrillus sphinx) was unsuccessful. This report is the first to describe spontaneous manufacture of tools in any group of Old World monkeys and provides evidence of greater continuity among primates for the expression of complex cognitive abilities. These data are consistent with hypotheses that lion-tailed macaques have extensive propensities for advanced sensorimotor skills and that omnivorous, extractive foraging is associated with the manufacture and use of tools. I present a proximate model that integrates sensorimotor and social factors to account for diverse expression of tool-related behavior.

Hand preference for a bimanual task in tufted capuchins (Cebus apella) and rhesus macaques (Macaca mulatta).

This research examined hand preference for a bimanual task in 45 tufted capuchin (Cebus apella) and 55 rhesus macaque (Macaca mulatta) monkeys. Investigators presented subjects with plastic tubes lined with food and noted which hand the animals used to hold the tubes and which hand the animals used to remove the food. Several significant findings emerged from this investigation. First, rhesus macaques, but not tufted capuchins, exhibited a population-level bias toward use of the right hand (although the difference in direction of hand preference between species was not significant). Second, capuchins exhibited greater hand preference strength than did macaques. Third, among capuchins, but not among macaques, hand preference strength was greater for adults than for immatures. Finally, both species used their index digit to remove food most frequently when compared with other digits. Findings of hand preference direction and strength in this study were compared with other findings noted for chimpanzees which performed a bimanual tube task in a previous study. The authors conclude that using the same procedure to compare hand preference across species represents a powerful research tool that can lead to a more complete understanding of the evolution and ontogenesis of primate handedness.

Lateral bias for rotational behavior in tufted capuchin monkeys (Cebus apella).

This research examined lateral bias for rotational behavior in tufted capuchin monkeys (Cebus apella). A symmetrical distribution of rotational bias was noted, with approximately equal numbers of subjects preferring to turn to the right and to the left. As a group, adults did not exhibit a lateral rotational bias. Immatures preferentially rotated to the left. Across subjects, the strength of rotational bias was positively related to the incidence of right-eyed looking. Rotational bias was not related to hand preference. The finding of analogous age-dependent patterns of rotational bias in capuchins and in humans suggests that the rotational behavior of Cebus apella can be used to model an asymmetric response pattern that has been linked to development in Homo sapiens.

Bipedal posture and hand preference in humans and other primates.

Hand preference for quadrupedal and bipedal reaching in humans and rhesus macaques (Macaca mulatta) was examined, and the data were compared with postural reaching data that have been reported for 8 other primate species. Population-level biases were found toward use of the right hand for quadrupedal and bipedal reaching in humans and use of the left hand for quadrupedal reaching in rhesus macaques. Rhesus macaques showed a significant shift toward greater use of the right hand for bipedal vs. quadrupedal reaching. Comparisons with other species showed significant variance in the direction and strength of hand preference across reaching postures. The study noted right-hand biases for bipedal reaching in humans, great apes, and tufted capuchins and shifts toward greater use of the right hand for bipedal vs. quadrupedal reaching in great apes, tufted capuchins, and rhesus macaques. These results suggest that posture alters both the direction and strength of primate hand preference and that bipedalism may have facilitated species-typical right-handedness in humans.

Why some capuchin monkeys (Cebus apella) use probing tools (and others do not).

Tufted capuchins (Cebus apella) were provided with a task that facilitated the use and modification of sticks as probing tools. It was found that subjects aged 10 years or older at initial task exposure were less likely to use tools than were younger subjects. Furthermore, juveniles whose mothers died before the subjects were aged 3 years were less likely to use tools than were juveniles whose mothers survived through this period. The ability to use tools was not related to subject sex or to access to the tool site or raw tool materials. Subjects modified tools both before and during their use, and the relative percentage of tools modified increased with subject age. Thus, it appears that capuchins most readily acquire tool use before the age of 10 years and that early disruption of the mother-infant relationship has deleterious effects on the emergence of instrumental behavior.

Hand preference in the use of tools by infant baboons (Papio cynocephalus anubis).

Hand preference in the use of tools was examined in a peer group of five infant baboons, Papio cynocephalus anubis. Hand preference was noted for all subjects on a sponging task and for one subject on a probing task. The baboons exhibited the highest percentage of bimanual actions on the initial segment of each three-component task. These results are consistent with the hypothesis that immature nonhuman primates exhibit lateral asymmetries when they use tools and bimanual coordination when they perform complex manipulative tasks.

Long-term monitoring drug resistance by ultra-deep pyrosequencing in a chronic hepatitis B virus (HBV)-infected patient exposed to several unsuccessful therapy schemes.

The aim of this study was to analyze the spectrum and dynamics of low-prevalent HBV mutations in the reverse transcriptase (rt) and S antigen by ultra-deep pyrosequencing (UDPS). Samples were obtained from a chronically infected patient who was followed throughout a thirteen-year period. This technology enabled simultaneous analysis of 4084 clonally amplified fragments from the patient allowing detecting low prevalent (<1%) mutations during the follow-up. At baseline, HBV sequences were predominately wild-type. Under sequential HBV monotherapies including lamivudine, adefovir and entecavir, a high frequency of rtM204I mutation was detected initially as unique and then coexisting with rtM204V. Both mutations were statistically associated with rtA200V and rtV207I, respectively. Once the entecavir and tenofovir combined therapy was started, polymerase and consequently envelope gene mutations appeared at several positions at a higher frequency than before, including the entecavir resistance-associated mutation rtT184L.

Capuchin monkey (Cebus apella) grips for the use of stone tools.

This research examined capuchin monkey (Cebus apella) grips for the use of throwing, nut-cracking and cutting tools. We provided subjects with stones and apparatus that accommodated the use of stones as tools. Our subjects exhibited five grips, two of which the animals used when force was the primary consideration (power grips) and three of which the animals used when accuracy of sensory judgment and instrumentation was required (precision grips). We believe that the range of contexts in which capuchins use stone tools, combined with the ability of capuchins to employ both power and precision grips as part of their tool repertoire, indicate that Cebus apella can be used to identify grips that facilitated hominid lithic technology.