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PubMed2003

Mitochondrial diversity of a northeast German population sample.

Mitochondrial DNA sequences of the hypervariable regions HV I and HV II were analyzed in 300 unrelated individuals born and living in the northeast corner of Germany (Western Pomerania) to generate a database for forensic identification purposes in this region. Sequence polymorphism were detected using PCR and direct sequencing analysis. A total of 242 different haplotypes were found as determined by 147 variable positions. The most frequent haplotype (263G, 315.1C) was found in 10 individuals and is also the most common sequence in Europe. Three other haplotypes were shared by 5 individuals, 2 sequences by 4, 8 haplotypes by 3, 15 sequences by 2 persons, and 213 sequences were unique. The genetic diversity was estimated to be 0.99 and the probability of two random individuals showing identical mitochondrial DNA (mtDNA) haplotypes is 0.6%. A comparison with other studies from Germany showed only little differences in the distribution of haplogroups. Nevertheless, one frequent haplotype in northeast Germany (five unrelated individuals) could only rarely be found in other German and European regions. Our results may indicate that despite a high admixture proportion in the German population some regions could demonstrate certain characteristic features.

DNA Fingerprinting↗

PubMed2005

Quantitative analysis of functional clustering of neurons in the macaque inferior temporal cortex.

Neurons with similar preferences for two-dimensional shapes of intermediate complexity cluster in area TE of the monkey inferior temporal cortex. To further characterize the functional structure of area TE, we quantitatively analyzed various aspects of the visual responses of closely located neurons by applying multiple single-unit recording techniques in anesthetized monkeys. Examination of the visual responses elicited with a large, predetermined set of visual stimuli confirmed previous findings that nearby neurons, on average, exhibited positively correlated preferences for a set of visual stimuli. Nearby neurons also tended to be similar in their receptive-field organization and contrast-polarity preference. In contrast, no correlation was found in the size tuning of neighboring neurons. Pooling or subtraction of activities between a pair of nearby neurons was shown to improve stimulus discriminability, if the neuron pair had positively or negatively correlated stimulus preferences, respectively. These results indicate that nearby TE neurons share some aspects of stimulus preference, but their response selectivity differ in other aspects. Both pooling and subtraction between nearby neurons can reduce across-trial response variability, if these decoding strategies are applied to appropriate neuronal pools.

Action Potentials↗

PubMed1998

Children experiencing violence. I: Parental use of corporal punishment.

OBJECTIVE: This study was undertaken to reveal the prevalence of corporal punishment in Alexandria and its' correlates with family background and child's behavior and characteristics. METHODS: A cross sectional survey targeting preparatory and secondary school children was conducted. The multistage random sample technique was adopted to select a representative sample of this population. Subjects were requested to complete a self-administered questionnaire to collect relevant information. Data were analyzed using the univariate and multivariate analyses. RESULTS: This study revealed that more than one-third (37.47%) of children were disciplined physically in the form of beating and a few were also burned or tied. In 25.83% of them, this harsh discipline led to physical injuries of variable degrees of severity amounting to fractures, loss of consciousness, and permanent disability. Predictive family background for the use of corporal punishment were: living in an apartment shared with strangers; high crowding index; constant fights and quarrels between family members; lack of regular relation with relatives and acquaintance as well as an income insufficient to meet the family basic needs. Predictive child's characteristics and behavior included young age; disobedience; telling lies; destroying others' belongings; acting disrespectfully to parents; communicating poorly with their parents; running away from home; and poor school achievement, in addition to other determinants. CONCLUSION: A proportion of children are subjected to extreme physical brutality amounting to abuse in a disciplinary context. Parents' education and the establishment of effective parent-child communication are deemed essential to combat this phenomenon.

Adolescent↗

PubMed2025

Cell fate specification modes shape transcriptome evolution in the highly conserved spiral cleavage.

Early animal development can be remarkably variable, influenced by lineage-specific reproductive strategies and adaptations. Yet, early embryogenesis is also strikingly conserved in certain groups, such as Spiralia. In this clade, a shared cleavage program (i.e., spiral cleavage) and similar cell lineages are ancestral to at least seven phyla. Why early development is so conserved in specific groups and plastic in others is not fully understood. Here, we investigated two annelid species (Owenia fusiformis and Capitella teleta) with spiral cleavage but different modes of specifying their primary progenitor cells. By generating high-resolution transcriptomic time courses from the oocyte to gastrulation, we demonstrate that transcriptional dynamics differ markedly between these species during spiral cleavage and instead reflect their distinct timings of embryonic organiser specification. However, the end of cleavage and gastrulation exhibit high transcriptomic similarity, when orthologous transcription factors share gene expression domains, suggesting this period is a previously overlooked mid-developmental transition in annelid embryogenesis. Together, our data reveal hidden transcriptomic plasticity during spiral cleavage, indicating an evolutionary decoupling of morphological and transcriptomic conservation during early embryogenesis.

Animals↗

PubMed1977

The microstructure of dual task interaction. 3. Incompatibility and attention switching.

This report is the third in a series of reports concerned with close analysis of a dual task situation in which a five-choice serial task is combined with an auditory--verbal response task. A situation is described in which 'incompatibility' is incorporated into the five-choice task in order to increase the information processing load and thus explore the effect on the mechanism believed to control the microstructure of the time-sharing process. Results supported the notion that subjects were continuing to operate a sequential processing strategy in combining the two tasks. The structure of the interval generated by the occurrence of the auditory--verbal task was different in comparison with the compatible five-choice condition reported earlier, suggesting that the introduction of incompatibility causes a change in the characteristics of the time-sharing process. The structure of the interval remained organised and consistent, suggesting that the mechanism which controlled the time-sharing process was not disrupted by increased main task load and therefore was likely to involve a process which did not compete for attention space with task variables. Results also revealed an effect of the digit task response on the following two serial responses. It was suggested that these were probably best described as two independent effects: one arising from the sequential processing strategy adopted, and the other arising perhaps as a function of perception of overall task difficulty.

Adult↗

PubMed1987

Allelic variation in the DR subregion of the human major histocompatibility complex.

Allelic variation in the DR subregion of the human major histocompatibility complex has been analyzed by nucleic acid sequencing of cDNA clones obtained from cell lines homozygous by consanguinity for all the common serological types DR1-9. Two expressed loci were identified in the haplotypes DR2, -3, -4, -7, and -9; one locus being present at a much lower frequency (4-7%) than the other. The low-frequency allele was highly conserved between each of the DRw53 (DR4, -7, -9) and the DRw52 (DR3, -5, -6) haplotypes. Analysis of the variation between alleles confirms the presence of three allelic hypervariable regions. At each variable residue, a limited range of amino acid substitutions are found, distinguishing them from immunoglobulin hypervariable regions. Dinucleotide substitutions are extremely common. Individual hypervariable regions are often shared between haplotypes. Much of the variation in these alleles can be attributed to the shuffling of these regions between haplotypes, possibly by the mechanism of gene conversion.

Alleles↗

PubMedDate not supplied

Involuntary exposure to tobacco smoke in adolescents: urinary cotinine and environmental factors.

The relationship between environmental tobacco smoke exposure and urinary cotinine was studied in 434 14-y-old schoolchildren. To estimate the independent contribution of physiological and environmental variables to cotinine concentrations, we conducted a multiple regression analysis of log-transformed cotinine (R(2) = .21, p < .0001). Environmental tobacco smoke exposure was associated with sharing a household with members who smoked. The most profound associations were linked to (a) the smoking habits of the mother (beta = 5.135, p = .0397); (b) the combined smoking habits of the mother and other family members (beta = 8.201, p = .0020); and (c) the total number cigarettes smoked each day by family members in the household (beta = 0.217, p = .0008). Passive smoke exposure of adolescents is a preventable risk that could be reduced by improving ventilation and by increasing the living space available to each family member. Parents should avoid smoking at home in the presence of their children.

Adolescent↗

PubMed1995

The evaluation of some factors influencing the sexual life of women affected by breast cancer.

Although there is clinical evidence that cancer patients become less interested in sexuality and develop some difficulties in sharing feelings and thoughts with their spouses, systematic information on the factors influencing intimacy are lacking. The aim of this study is to explore the importance of variables such as reaction to illness and scarring, and marital satisfaction on the patients' capability to resume an enjoyable sexual life following surgery and radiation for the treatment of their tumors.

Adult↗

PubMedDate not supplied

Microsatellite DNA markers from HLA region (D6S105, D6S265 and TNFa) in autochthonous Basques from Northern Navarre (Spain).

BACKGROUND: The extent of the genetic polymorphism of the HLA complex is becoming well characterized in Basque population and their subpopulations. This level of knowledge mainly concerns HLA class I loci. However, Basque population surveys dealing with HLA class II genes and/or microsatellites in the HLA region are still very scarce. AIM: The population genetics of three highly polymorphic short tandem repeat (STR) loci, D6S105, D6S265 and TNFa, from HLA region has been analysed in autochthonous (indigenous) Basques from Northern Navarre (Spain). The same blood samples have been typed for HLA class II genes from DQ/DR/DP regions and some findings from that information can be found therein. SUBJECTS AND METHODS: Blood samples were taken from 107 unrelated autochthonous Basques from Northern Navarre. The criterion used to define Northern Navarrese identity was that of three generations of Basque surnames and birthplaces. RESULTS: The main features observed in Navarrese Basques were the rather high frequencies of alleles D6S105*4 and D6S265*7. A novel allele has been detected at the D6S265 locus (13: 145 bp). The most frequent haplotype was D6S105*8-D6S265*4 with a highly significant linkage disequilibrium being presented. The high frequency of allele TNFa*1 in Basques is noteworthy and this characteristic is not shared by other European populations, where TNFa*1 is absent or shows negligible values. The multidimensional scaling analysis (MDS) for TNFa allele frequencies has shown a high variability among populations and that alleles TNFa*1 (F(ST) = 0.0615) and TNFa*12 (F(ST) = 0.0424) seem to have significant influence over the spatial population configuration. TNFa*2 showed the lowest FST value (0.0077) because of its conspicuous homogeneous distribution all over the European populations. CONCLUSIONS: Findings shown here on HLA microsatellites and their relationships with other HLA class I and class II genes in Basques can be helpful for those studies mainly addressed at detecting associations between HLA genes and diseases in the Basque area as a whole, and particularly in its autochthonous population, settled there since remote times.

Alleles↗

PubMed2006

Nonverbal estimation during numerosity judgements by adult humans.

On an automated task, humans selected the larger of two sets of items, each created through the one-by-one addition of items. Participants repeated the alphabet out loud during trials so that they could not count the items. This manipulation disrupted counting without producing major effects on other cognitive capacities such as memory or attention, and performance of this experimental group was poorer than that of participants who counted the items. In Experiment 2, the size of individual items was varied, and performance remained stable when the larger numerical set contained a smaller total amount than the smaller numerical set (i.e., participants used numerical rather than nonnumerical quantity cues in making judgements). In Experiment 3, reports of the number of items in a single set showed scalar variability as accuracy decreased, and variability in responses increased with increases in true set size. These data indicate a mechanism for the approximate representation of numerosity in adult humans that might be shared with nonhuman animals.

Adult↗

PubMed1999

The ancestry of a sample of sequences subject to recombination.

In this article we discuss the ancestry of sequences sampled from the coalescent with recombination with constant population size 2N. We have studied a number of variables based on simulations of sample histories, and some analytical results are derived. Consider the leftmost nucleotide in the sequences. We show that the number of nucleotides sharing a most recent common ancestor (MRCA) with the leftmost nucleotide is approximately log(1 + 4N Lr)/4Nr when two sequences are compared, where L denotes sequence length in nucleotides, and r the recombination rate between any two neighboring nucleotides per generation. For larger samples, the number of nucleotides sharing MRCA with the leftmost nucleotide decreases and becomes almost independent of 4N Lr. Further, we show that a segment of the sequences sharing a MRCA consists in mean of 3/8Nr nucleotides, when two sequences are compared, and that this decreases toward 1/4Nr nucleotides when the whole population is sampled. A measure of the correlation between the genealogies of two nucleotides on two sequences is introduced. We show analytically that even when the nucleotides are separated by a large genetic distance, but share MRCA, the genealogies will show only little correlation. This is surprising, because the time until the two nucleotides shared MRCA is reciprocal to the genetic distance. Using simulations, the mean time until all positions in the sample have found a MRCA increases logarithmically with increasing sequence length and is considerably lower than a theoretically predicted upper bound. On the basis of simulations, it turns out that important properties of the coalescent with recombinations of the whole population are reflected in the properties of a sample of low size.

Genome, Human↗

PubMed1986

Promoters of Agrobacterium tumefaciens Ti-plasmid virulence genes.

The DNA sequences of the promoter and 5' upstream regions of six Agrobacterium tumefaciens Ti-plasmid encoded virulence (vir) genes were determined. The transcription initiation sites were mapped by the S1 nuclease protection assay. In the -10 region, the vir promoters share a consensus sequence that is homologous to a DNA sequence found in the same region of E. coli promoters. In contrast, the -35 region sequences are variable. Several vir genes contain two common hexanucleotide sequences, 5'CGAGTA3' and 5'GCAATT3'. Translation initiation codons for all vir genes, except virG, are preceded by sequences homologous to the ribosome binding site sequences found in E. coli.

Base Sequence↗

PubMed2005

Immunophenotypic comparison of salivary gland oncocytoma and metastatic renal cell carcinoma.

OBJECTIVES/HYPOTHESIS: The differential diagnosis of oncocytic neoplasms of salivary glands includes both primary and metastatic tumors, one of which is renal cell carcinoma. This study compared immunohistochemical staining characteristics of oncocytomas arising from salivary gland to metastatic renal cell carcinoma using a panel of markers. STUDY DESIGN: Immunohistochemistry for cytokeratin 7 (CK7), cytokeratin 20 (CK20), epithelial membrane antigen (EMA), vimentin, CD10, and renal cell carcinoma marker (RCC) was performed on 10 oncocytomas and compared with ten metastatic renal cell carcinomas. RESULTS: There were overlapping histologic findings in the oncocytomas and metastatic renal cell carcinomas, with oncocytomas displaying clear cell changes in 2 of 10 cases. CK7 was positive in 9 of 10 oncocytomas and CK20 in 8 of 10 (7/10 stained for both), and vimentin was only weakly positive in 4 of 10 oncocytomas. All oncocytomas were EMA positive, with membranous staining, and all were negative for CD10 and RCC. Metastatic renal cell carcinoma was strongly positive for vimentin, EMA, and CD10 in most cases. RCC and CK7 were variably positive in metastatic renal cell carcinomas (4/10), and only 1 of 10 showed weak staining with CK20. CONCLUSIONS: Salivary gland oncocytomas and metastatic renal cell carcinomas share some similar histologic and immunohistochemical characteristics. CD10 and CK20 were the most useful markers to distinguish metastatic renal cell carcinoma from oncocytomas in the salivary gland, whereas RCC, EMA, CK7, and vimentin are not as useful.

Adenoma, Oxyphilic↗

PubMed1995

Distribution of HLA and haplotypes of Colombian and Jamaican black populations.

To investigate the genetic background of the black populations of Colombia and Jamaica, we determined HLA types of 78 Colombian and 98 Jamaican blacks from 2 different socioeconomic groups (Jamaican #1 and Jamaican #2) and estimated the frequencies of HLA genes and haplotypes. A phylogenetic tree based on the HLA gene frequencies revealed that Jamaican #1 and Jamaican #2 were distinct from each other, Jamaican #1 being closely related to the Colombian blacks and the Jamaican #2 being closely related to Senegalese and Zairean populations. Three-locus HLA haplotypes of Colombian and Jamaican #1 blacks were an admixture between Africans and Caucasians or South American Indians, while Jamaican #2 blacks were relatively homogeneous and appeared to conserve African lineages. The major five-locus HLA haplotypes were not shared among Colombian, Jamaican #1 and Jamaican #2 blacks. These results indicated that the black populations of Colombia and Jamaican were originated from African blacks and admixed variably with Caucasians and South American Indians to make genetic subpopulations in Colombia and Jamaica.

Black People↗

PubMed2002

Molecular identification and genetic diversity within species of the genera Hanseniaspora and Kloeckera.

Three molecular methods, RAPD-PCR analysis, electrophoretic karyotyping and RFLP of the PCR-amplified ITS regions (ITS1, ITS2 and the intervening 5.8S rDNA), were studied for accurate identification of Hanseniaspora and Kloeckera species as well as for determining inter- and intraspecific relationships of 74 strains isolated from different sources and/or geographically distinct regions. Of these three methods, PCR-RFLP analysis of ITS regions with restriction enzymes DdeI and HinfI is proposed as a rapid identification method to discriminate unambiguously between all six Hanseniaspora species and the single non-ascospore-forming apiculate yeast species Kloeckera lindneri. Electrophoretic karyotyping produced chromosomal profiles by which the seven species could be divided into four groups sharing similar karyotypes. Although most of the 60 strains examined exhibited a common species-specific pattern, a different degree of chromosomal-length polymorphism and a variable number of chromosomal DNA fragments were observed within species. Cluster analysis of the combined RAPD-PCR fingerprints obtained with one 10-mer primer, two microsatellite primers and one minisatellite primer generated clusters which with a few exceptions are in agreement with the groups as earlier recognized in DNA-DNA homology studies.

Animals↗

PubMed1989

Melatonin and pituitary-gonadal function in disorders of eating behavior.

In order to study the possible relationships between melatonin secretion and pituitary-gonadal function, the circadian rhythm of plasma melatonin, the basal levels of estradiol-17beta and testosterone and the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) response to luteinizing hormone-releasing hormone (LH-RH) stimulation were evaluated in normally cycling healthy women and in two groups of women with menstrual dysfunctions related to eating disorders (19 patients with anorexia nervosa and 16 with primary obesity). The circadian rhythm of plasma melatonin reached statistical significance in anorectic patients but not in obese patients. The mean 24 h melatonin level was significantly higher in anorectic than in obese patients and in control subjects. However, both groups of patients shared some abnormalities of melatonin circadian pattern, such as increased ratio between day and night melatonin levels, abnormal secretory peaks during the light hours and great interindividual variability for timing, amplitude, and duration of melatonin nocturnal peak. A selective impairment of LH secretion was observed in both anorectic and obese patients. By considering together the two groups of patients and controls, a linear inverse correlation between the circadian mesor of plasma melatonin and the basal and LH-RH stimulated LH levels was found. The persistence of a certain melatonin secretion during the light hours in both anorectic and obese patients could play an inhibitory role on the pituitary gonadal function in these subjects.

Adolescent↗

PubMed1995

Detection of genetic diversity in tea (Camellia sinensis) using RAPD markers.

Camellia sinensis is a beverage tree crop native to Southeast Asia and introductions have been made into several nonindigenous countries. No systematic assessment of genetic variability in tea has been done anywhere. In this study, random amplified polymorphic DNA (RAPD) analysis was used to estimate genetic diversity and taxonomic relationships in 38 clones belonging to the three tea varieties, assamica, sinensis, and assamica ssp. lasiocalyx. Extensive genetic variability was detected between species, which was partitioned into between and within population components. Seventy percent of the variation was detected within populations. Analyses based on band sharing separated the three populations in a manner consistent with both the present taxonomy of tea and with the known pedigrees of some clones. RAPD analysis also discriminated all of the 38 commercial clones, even those which cannot be distinguished on the basis of morphological and phenotypic traits.

Base Sequence↗

PubMed2002

Two-dimensional femtosecond spectroscopy.

The simplest two-dimensional (2D) spectra show how excitation with one (variable) frequency affects the spectrum at all other frequencies, thus revealing the molecular connections between transitions. Femtosecond 2D Fourier transform (2D FT) spectra are more flexible and share some of the remarkable properties of their conceptual parent, 2D FT nuclear magnetic resonance. When 2D FT spectra are experimentally separated into real absorptive and imaginary refractive parts, the time resolution and frequency resolution can both reach the uncertainty limit set for each resonance by the sample itself. Coherent four-level contributions to the signal provide new molecular phase information, such as relative signs of transition dipoles. The nonlinear response can be picked apart by selecting a single coherence pathway (e.g., specifying the relative signs of energy level difference frequencies during different time intervals as in the photon echo). Because molecules are frozen on the femtosecond timescale, femtosecond 2D FT experiments can separate a distribution of instantaneous molecular environments and intramolecular geometries as inhomogeneous broadening. This review provides an introduction to two-dimensional Fourier transform experiments exploiting second- and third-order vibrational and electronic nonlinearities.

Journal Article↗