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PubMed1992

Comparison of five tandem repeat loci between humans and chimpanzees.

Five tandem repeat loci were studied in humans and chimpanzees using VNTR probes derived from human DNA. Shared alleles were found at three loci and were often the modal allele in one species but never in both. There was no difference in the mean number of alleles per locus. However, these species exhibited substantially different levels of gene diversity, with chimpanzees monomorphic at two loci. Evidence of reduced variability in chimpanzees corroborates earlier comparisons using isozymes and plasma proteins. Molecular mechanisms, population dynamics, or both may be responsible for these differences. Equal numbers of alleles per locus may reflect high mutation rates. By one test, chimpanzees were out of equilibrium at one locus, which may reflect a typing error or population substructure. The long divergence time, and the high probability of backward mutations, precludes accurate estimation of genetic distance between these species.

Alleles↗
PubMed1995

Sequence variation of the human Y chromosome.

We have generated over 100 kilobases of sequence from the nonrecombining portion of the Y chromosomes from five humans and one common chimpanzee. The human subjects were chosen to match the earliest branches of the human mitochondrial tree. The survey of 18.3 kilobases from each human detected only three sites at which substitutions were present, whereas the human and chimpanzee sequences showed 1.3% divergence. The coalescence time estimated from our Y chromosome sample is more recent than that of the mitochondrial genome. A recent coalescence time for the Y chromosome could have been caused by the selected sweep of an advantageous Y chromosome or extensive migration of human males.

Animals↗
PubMed2006

Diversity of microRNAs in human and chimpanzee brain.

We used massively parallel sequencing to compare the microRNA (miRNA) content of human and chimpanzee brains, and we identified 447 new miRNA genes. Many of the new miRNAs are not conserved beyond primates, indicating their recent origin, and some miRNAs seem species specific, whereas others are expanded in one species through duplication events. These data suggest that evolution of miRNAs is an ongoing process and that along with ancient, highly conserved miRNAs, there are a number of emerging miRNAs.

Animals↗
PubMed2006

'Chumanzee' evolution: the urge to diverge and merge.

A recent analysis of the human and chimpanzee genomes compared with portions of other primate genomes suggests that the divergence of the human and chimpanzee lineages beginning around 6 million years ago was not a simple clean split.

Animals↗
PubMed2006

Functionality of intergenic transcription: an evolutionary comparison.

Although a large proportion of human transcription occurs outside the boundaries of known genes, the functional significance of this transcription remains unknown. We have compared the expression patterns of known genes as well as intergenic transcripts within the ENCODE regions between humans and chimpanzees in brain, heart, testis, and lymphoblastoid cell lines. We find that intergenic transcripts show patterns of tissue-specific conservation of their expression, which are comparable to exonic transcripts of known genes. This suggests that intergenic transcripts are subject to functional constraints that restrict their rate of evolutionary change as well as putative positive selection to an extent comparable to that of classical protein-coding genes. In brain and testis, we find that part of this intergenic transcription is caused by widespread use of alternative promoters. Further, we find that about half of the expression differences between humans and chimpanzees are due to intergenic transcripts.

Animals↗
PubMed1983

Studies in chimpanzees of live, attenuated hepatitis A vaccine candidates.

Human hepatitis A virus was attenuated in virulence for chimpanzees by passage in FRhK6 and human diploid lung fibroblast cell cultures. A number of variants were developed by passage in cell cultures which showed different levels of virulence/attenuation for chimpanzees. These results were compared to those obtained with marmosets and reported previously. In general, most variants behaved similarly in the two animal types. Two chimpanzees which gave vaccine-like responses following inoculation with HAV cell culture variants were challenged with virulent HAV. Both animals were immune to HAV infection. These findings provide further evidence for the feasibility of developing live, attenuated vaccines against human hepatitis A.

Animals↗
PubMed1997

Perceived need to alter eating habits among representative samples of adults from all member states of the European Union.

OBJECTIVE: To examine the perceived need to alter eating habits among nationally-representative samples from each member state of the European Union (EU). DESIGN: A cross-sectional study in which quota-controlled, nationally-representative samples of approximately 1000 adults from each country completed a face-to-face interview-assisted questionnaire. SETTING: The survey was conducted between October 1995 and February 1996 in the 15 member states of the European Union. SUBJECTS: 14,331 subjects (aged 15 y upwards) completed the questionnaire. Data were weighted by population size for each country and by sex, age and regional distribution within each member state. RESULTS: 71% of EU subjects agreed with the statement 'I do not need to make changes to the food I eat, as it is already healthy enough'. There was wide variation between the member states ranging from 47% in Finland to 87% in Italy indicating agreement. Overall there was little difference between the sexes except in Austria, Belgium, Germany, Greece and Ireland, but the proportions of subjects agreeing with the statement generally increased with advancing age and decreased with higher levels of education. The effects of demographics were not consistent across member states. A total of 49% of EU subjects agreed with the statement 'I usually do not think of the nutritional aspects of the food I eat'. Significantly more females than males disagreed with the statement in all countries except Portugal. In all member states there were widespread beliefs that people in general should decrease their consumption of savoury snacks and increase their consumption of fruit and vegetables. CONCLUSIONS: The results of this study demonstrate that dietary advice may not be perceived as personally relevant among EU subjects. In addition important target groups for the promotion of healthy eating have been identified for example, males or subjects with low levels of education. Because of the variation in attitudes a single pan-EU healthy eating programme is unlikely to be effective for all countries or for different demographic groups.

Adolescent↗
PubMed1993

Genetic analysis of hematological traits in chimpanzees (Pan troglodytes).

Hematological traits are commonly assessed markers of health status that have been used in a large number of anthropological studies, especially those focusing on high-altitude adaptation. Despite the wealth of literature on environment-associated variation in these traits, relatively few studies have dealt with the underlying genetic components of hematological measures. The purpose of this study is to estimate heritabilities for eight hematological traits using data obtained from a large pedigreed chimpanzee colony. Seven of the eight hematological traits exhibited significant heritabilities, ranging from h2 = 0.308 for mean cell volume to h2 = 0.834 for red blood cell count. The use of multiple measures per individual proved to be essential for the accurate estimation of heritabilities. We conclude that the underlying genetic variation in hematological traits should be considered when these measures are used in study protocols.

Animals↗
PubMed2003

The Neanderthal taxonomic position: models of intra- and inter-specific craniofacial variation.

The Neanderthal taxonomic position is a matter of wide disagreement among paleoanthropologists. Some workers consider this fossil human group to represent a different species, Homo neanderthalensis, while others see it as a subspecies of Homo sapiens. This study developed two models of morphological variation to be applied to a comparison between Neanderthals and modern humans: modern human populations provided a measure of intra-specific variation, while the species and subspecies of Pan provided measures of both intra- and inter-specific morphological differences. Although such an approach has been advocated strongly, it has not been systematically undertaken until recently. The techniques of geometric morphometrics were used to collect data in the form of three-dimensional coordinates of craniofacial landmarks. The data were processed using generalized procrustes analysis, and analyzed by an array of multivariate statistical methods, including principal components analysis, canonical variates analysis and Mahalanobis D(2). The morphological distances between Neanderthals and modern humans, and between Neanderthals and Late Paleolithic/early anatomically modern specimens, are consistently greater than the distances among recent human populations, and greater than the distances between the two chimpanzee species. Furthermore, no strong morphological similarities were found between Neanderthals and Late Paleolithic Europeans. This study does not find evidence for Neanderthal contribution to the evolution of modern Europeans. Results are consistent with the recognition of Neanderthals as a distinct species.

Anatomy, Comparative↗
PubMed2005

Movement of different-shaped particles in a pan-coating device using novel video-imaging techniques.

The purpose of this study was to investigate the effects of particle shape on the movement of particles in a pan-coating device using novel video-imaging techniques. An area scan CCD camera was installed inside a 24-in pan coater at the same location as that of a spray nozzle, and the movement of particles was tracked using machine vision. A white tracer particle was introduced inside a bed of black-coated particles. The effects of pan loading, pan speed, and particle shape on the movement of particles was studied. The response variables were circulation time, surface time, projected area of particle per pass, dynamic angle of repose, cascading velocity, and dispersion coefficient. Experiments were conducted at 3 different pan speeds, 6, 9, and 12 rpm, and 2 fill levels (ratio of bed depth to pan diameter), one eighth and one quarter, and data were collected over a 30-minute time period. The differences in circulation times of spheres and tablets, with similar volume equivalent diameter as that of the sphere, were found to be insignificant at the 95% confidence interval. The circulation time ranged from 2.8 to 10.8 seconds depending on the operating condition and increased with increasing pan load and decreasing pan speed. The distributions of circulation time, surface time, and projected surface area were found to be nonnormal. The dynamic angle of repose for tablets was higher than for spheres. Also, the bed surface for spheres was much flatter in comparison with tablets where the bed shape attained a "wave-like" form. The average velocity of tablets in the cascading layer was found to be significantly higher than spheres. A linear model (R(2) > 0.98) best described the variation of velocity as a function of pan speed for all of the operating conditions.

Motion↗
PubMed2002

Identifying metameric variation in extant hominoid and fossil hominid mandibular molars.

Landmark data were collected from cross sections and occlusal images of mandibular molar crowns, and Euclidean distance matrix analysis (EDMA) was used to identify metameric morphological variation between the first and second mandibular molars of living taxa: Gorilla gorilla (n = 30), Pan troglodytes (n = 34), and Homo sapiens (n = 26). Two patterns of metameric variation were identified, one unique to humans and the other shared by chimpanzees and gorillas. In order to assess the utility of this type of analysis for the interpretation of the hominid fossil record, 19 mandibular molars from Sterkfontein Member 4, South Africa, were examined. The pattern of metameric variation of the Sterkfontein molars resembled that of the African great apes, and differed from the modern human pattern. These results demonstrate that data on metameric variation may provide information regarding function or developmental processes previously indiscernible from fossil material.

Animals↗
PubMed1980

Oxygenation and ambient air pressure influences on alcohol-induced nystagmus in rabbits.

The effect of ambient pressure with various inspiratory partial pressures of oxygen on the duration of positional alcohol nystagmus (PAN) was investigated in rabbits. In five groups of rabbits, partial pressures of oxygen were applied. Alcohol was administered intravenously in a dosage of 2.85 g/kg body weight. PAN was recorded by electronystagmography. Neither a change of ambient pressure, nor a variation of the inspired oxygen partial pressure had any influence on the duration of PAN. The blood alcohol concentration did not differ significantly between the groups. The theoretical discussion is completed with the practical message that oxygen therapy does not help sobering up. In 6 out of 46 rabbits followed, there occurred a positional alcohol nystagmus type II, i.e. with reversed beat direction.

Air Pressure↗
PubMed2005

Subspecies composition and founder contribution of the captive U.S. chimpanzee (Pan troglodytes) population.

Chimpanzees are presently classified into three subspecies: Pan troglodytes verus from west Africa, P.t. troglodytes from central Africa, and P.t. schweinfurthii from east Africa. A fourth subspecies (P.t. vellerosus), from Cameroon and northern Nigeria, has been proposed. These taxonomic designations are based on geographical origins and are reflected in sequence variation in the first hypervariable region (HVR-I) of the mtDNA D-loop. Although advances have been made in our understanding of chimpanzee phylogenetics, little has been known regarding the subspecies composition of captive chimpanzees. We sequenced part of the mtDNA HVR-I region in 218 African-born population founders and performed a phylogenetic analysis with previously characterized African sequences of known provenance to infer subspecies affiliations. Most founders were P.t. verus (95.0%), distantly followed by the troglodytes schweinfurthii clade (4.6%), and a single P.t. vellerosus (0.4%). Pedigree-based estimates of genomic representation in the descendant population revealed that troglodytes schweinfurthii founder representation was reduced in captivity, vellerosus representation increased due to prolific breeding by a single male, and reproductive variance resulted in uneven representation among male P.t.verus founders. No increase in mortality was evident from between-subspecies interbreeding, indicating a lack of outbreeding depression. Knowledge of subspecies and their genomic representation can form the basis for phylogenetically informed genetic management of extant chimpanzees to preserve rare genetic variation for research, conservation, or possible future breeding.

Africa↗
PubMed2003

Inhibition by heparin of protein kinase C activation and hydroxyl radical generation in puromycin aminonucleoside treated isolated rat hepatocytes.

Heparin has been reported to have many actions similar to calcium-dependent protein kinase (PKC) inhibitors. We have found that puromycin aminonucleoside (PAN) increases hydroxyl radical generation and this was prevented by H-7, a PKC inhibitor in isolated rat hepatocytes. In this study, we investigate the effect of heparin on the increased hydroxyl radical generation as well as PKC activation by PAN in isolated rat hepatocytes. To estimate the amount of hydroxyl radical generation, we measured methylguanidine (MG) and creatol which are the products from the reaction of creatinine and hydroxyl radical. Synthetic rate of MG plus creatol in isolated rat hepatocytes incubated in Krebs-Henseleit bicarbonate buffer containing creatinine and tested reagents were recorded. This rate with or without PAN was 231 +/- 11 or 112 +/- 5.6 nmol/g wet cells/4 h (mean +/- S.E., n = 5), respectively. Heparin concentrations of 3.3, 6.6 and 10 U/ml inhibited MG plus creatol synthesis in the presence of PAN by 30, 38 and 39%, and without PAN by 8.4, 27 and 34%, respectively. Statistical significance was observed except for 3.3 U/ml without PAN. The ratio of PKC in membrane/cytoplasmic fraction, an indicator of PKC activation, increased 2.8- and 3-fold that of the 0 time after 60 and 120 min incubation with PAN while heparin at 10 U/ml almost completely suppressed this increase in the ratio of PKC. The PKC ratio of the membrane/cytoplasmic fraction obtained from hepatocytes with heparin alone or without PAN and heparin was almost unchanged during the tested period. Variation of PKC levels in membrane fraction is similar to that of PKC ratio of the membrane/cytoplasmic fraction. Increased creatol synthesis by PAN and its inhibition by heparin were observed in the same samples as those used for the PKC study. These results indicate that heparin inhibits the increase in hydroxyl radical generation induced by PAN through inhibition of PKC activation in isolated rat hepatocytes.

Animals↗
PubMed2025

The MTORC1 signaling pathway related gene POLR3G serves as a potential prognostic biomarker in Hepatocellular Carcinoma.

This study aims to investigate the prognostic significance and potential biological functions of the MTORC1 signaling pathway-associated gene POLR3G in Hepatocellular carcinoma (HCC). A prognostic risk model for HCC was developed by integrating HCC-related datasets and associated clinical data obtained from The Cancer Genome Atlas (TCGA) database. The GSVA website was employed to analyze the model genes across pan-cancer datasets, focusing on copy number variations (CNV), single nucleotide variations (SNV), methylation differences, drug sensitivity and immune cell infiltration profiles. Subsequently, we examined the expression levels and prognostic significance of POLR3G in HCC. Utilizing Spearman correlation analysis, we identified genes associated with POLR3G. Furthermore, Gene Set Enrichment Analysis (GSEA) was employed to elucidate the potential signaling pathways in which POLR3G may be involved. The relationship between POLR3G expression and immune cell abundance in HCC samples was assessed using the ssGSEA algorithm. Finally, the impact of POLR3G on HCC cell proliferation was validated through CCK-8 and EDU cell proliferation assays. Through univariate Cox regression analysis and LASSO regression analysis, we established a prognostic risk model for HCC comprising 13 genes. The analysis revealed that individuals categorized in the low-risk group had a markedly improved overall survival probability relative to those in the high-risk group. POLR3G exhibited a markedly elevated expression in HCC tissues when compared to adjacent normal tissues. The expression of POLR3G was correlated with tumor grade, and elevated POLR3G expression was associated with poor prognosis in HCC patients. Furthermore, the expression level of POLR3G was found to be correlated with the level of immune cell infiltration. Knockdown of POLR3G significantly inhibited the proliferative capacity of hepatocellular carcinoma cells. The findings suggest that POLR3G may serve as a potential biomarker influencing the prognosis of hepatocellular carcinoma patients by modulating the tumor immune microenvironment.

Humans↗