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PubMed2006

Variation in Xi chromatin organization and correlation of the H3K27me3 chromatin territories to transcribed sequences by microarray analysis.

The heterochromatin of the inactive X chromosome (Xi) is organized into nonoverlapping bands of trimethylated lysine-9 of histone H3 (H3K9me3) and trimethylated lysine-27 of histone H3 (H3K27me3). H3K27me3 chromatin of the Xi is further characterized by ubiquitylated H2A and H4 monomethylated at lysine-20. A detailed examination of the metaphase H3K9me3 pattern revealed that banding along the chromosome arms is not a consistent feature of the Xi in all cell lines, but instead is generally restricted to the centromere and telomeres. However, H3K9me3 does form a reproducible band centered at Xq13 of the active X. In contrast, H3K27me3 banding is a feature of all Xi, but the precise combination and frequency of bands is not consistent. One notable exception is a common band at Xq22-23 that spans 12-15 Mb. The detailed examination of the chromatin territory by microarray analysis refined the H3K27me3 band as well as revealed numerous less extensive clusters of H3K27me3 signals. Furthermore, the microarray analysis indicates that H3K27me3 bands are directly correlated with gene density. The reexamination of the chromosome wide banding indicates that other major H3K27me3 bands closely align with regions of highest gene density.

Cell Line↗
PubMedDate not supplied

[The scent marking of territory of gerbils: a comparative analysis exemplified by 4 species of the genus Meriones].

Sex-age and seasonal variability of the ventral glands and different stereotypes of scent marking behaviour in four Meriones species (M. unguiculatus, M. meridianus, M. libycus, M. tamariscinus) have been studied in nature and under semi-natural conditions. Two major ways of olfactory marking are considered: by secretion of the ventral glands and by "signal heaps" with urine and feces. Intraspecific and inter-species variability of marking activity is investigated. The ventral glands start to function at the period of preparation of a generative system to reproduction. The peak of secretary activity of gland and maximum of two types of marking activity is observed in spring and early summer, i.e. the period of active reproduction. The maximum of two types of the marking activity is observed during this period. In M. tamariscinus and M. meridianus the marking by the ventral gland is prevailing mode of the territory scent marking, while Mongolian gerbils (M. unguiculatus) prefer to use "signal heaps" Libyan gerbils (M. libycus) in this relation take an intermediate position. At the non-productive period a level of marking activity is on 10-20 times lower than at the reproductive season. Besides hormonal, social factors were also important for regulation of marking activity. By influence of these factors the differences in the level of marking activity in high-rank and low-rank individuals and differences in patterns of a spatial distribution of scent marks in individuals of different hierarchical rank is explained. Functional significance of various ways of territory scent marking is discussed.

Animals↗
PubMed1992

Efferent connections of the centromedian and parafascicular thalamic nuclei in the squirrel monkey: a light and electron microscopic study of the thalamostriatal projection in relation to striatal heterogeneity.

The organization of the thalamostriatal projections arising from the centromedian (CM) and parafascicular (Pf) thalamic nuclei in the squirrel monkey (Saimiri sciureus) was studied at both light and electron microscopic levels. Following selective injections of the anterograde axonal tracer Phaseolus vulgaris-leucoagglutinin (PHA-L) into the CM or Pf, patterns of terminal arborization within the striatum were compared to the biochemical heterogeneity of the striatum as revealed by immunohistochemical staining for the calcium-binding protein calbindin D-28k (CaBP), and histochemical staining for the enzymes acetylcholinesterase (AChE) and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-diaphorase). The PHA-L-labeled axon terminals within the striatum were further analyzed at the ultrastructural level to characterize their pattern of synaptic organization. Dense and heterogeneous terminal fields occur in the "sensorimotor" territory of the striatum after CM injections, or in the "associative" striatal territory following Pf injections. In the associative territory labeled axons arborize in a diffuse manner predominantly within areas enriched with CaBP, AChE, or NADPH-diaphorase, representing the matrix compartment, and tend to avoid areas poor in these substances, corresponding to the patch/striosome compartment. In the sensorimotor territory labeled axons form bands that occupy a subregion of the NADPH-diaphorase-rich zone in the putamen. The terminal pattern of the CM-striatal projection suggests the existence of a more complex mosaic organization within the sensorimotor territory. Ultrastructural analysis of PHA-L-labeled elements within the striatum reveals that both CM and Pf projections form asymmetric synapses upon dendrites and spines of striatal cells. A total of 339 PHA-L-labeled boutons were examined after CM injections and compared to 293 boutons following Pf injections. After CM injections, 29% of PHA-L-labeled terminals form synapses on dendritic spines and 66% on dendritic shafts, whereas after Pf injections only 12% of synapses occur on dendritic spines compared to 81% on dendritic shafts. Labeled terminals forming axosomatic or axoaxonic synapses were not seen within the striatum following either CM or Pf injections. It is concluded that in the squirrel monkey: 1) Pf-striatal fibers profusely arborize within the matrix compartment of the associative territory, 2) CM-striatal fibers form bands that occupy a subregion of the NADPH-diaphorase-rich zone within the sensorimotor territory, and 3) that both Pf- and CM-striatal projections establish asymmetric synapses with dendrites and spines of medium-sized spiny cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholinesterase↗
PubMed2006

Gaping displays reveal and amplify a mechanically based index of weapon performance.

Physical prowess, a key determinant of fight outcomes, is contingent on whole-organism performance traits. The advertisement of performance, via display, is poorly understood because it is unclear how information about performance is encoded into display characteristics. Previous studies have shown that weapon performance (i.e., bite force) predicts dominance and reproductive success in male lizards. We tested the hypothesis that gaping displays by adult male collared lizards (Crotaphytus) can provide an index of weapon performance by exposing the major jaw-adductor muscle complex and that white patches at the mouth corners amplify this index. For territorial adult males, the breadth of the muscle complex, which is not correlated with body size, was a strong predictor of bite force. For nonterritorial yearling males and females, however, measures of body and head size predicted bite force. The patches are highly conspicuous, exhibit UV-reflecting properties within the visual range of lizards, and provide size-independent information about bite force only in adult males. We conclude that exposure of the muscle complex during gaping displays can provide rival males with a reliable, body-size independent, biomechanically based index of weapon performance, an index that the mouth-corner patches amplify. Indexes that transmit information through mechanistic links to performance are expected to be widespread among animals.

Animal Communication↗
PubMed2001

ESS analysis of mechanistic models for territoriality: the value of scent marks in spatial resource partitioning.

In this paper elements of game theory are used to analyse a spatially explicit home range model for interacting wolf packs. The model consists of a system of nonlinear partial differential equations whose parameters reflect the movement behavior of individuals within each pack and whose solutions describe the patterns of space-use by each pack. By modifying the behavioral parameters, packs adjust their patterns of movement so as to maximize their reproductive output. This involves a tradeoff between maximizing prey intake and minimizing conflict with neighbors. Evolutionarily stable choices of the behavioral parameters yields territories that are immune to invasion by groups with alternate behaviors.

Animals↗
PubMed1995

Origin and evolution of viroids and viroid-like satellite RNAs.

Viroids, the smallest and simplest agents of infectious disease, cause a number of economically important diseases of crop plants. Present evidence indicates that most of these diseases originated recently (in the 20th century) by chance transfer of viroids from endemically infected wild plants or by use of viroid-infected germplasm during plant breeding. Modern agricultural practices, such as widespread monoculture of genetically identical plants, and worldwide distribution of planting material, has made it possible for the pathogens to maintain themselves in the crop plants and to conquer new territories. Phylogenetic analysis of their nucleotide sequences indicates that viroids and satellite RNAs represent a monophyletic group, with all but the two self-cleaving viroids forming one cluster and the satellite RNAs another. The two self-cleaving viroids are phylogenetically distant from either cluster; they may represent ancestral forms. Results from site-directed mutagenesis experiments indicate that, upon exposure to selective pressures, viroids can evolve extremely rapidly, with another, fitter, component of the quasi-species often becoming dominant within days or weeks. This extreme plasticity of their nucleotide sequences establishes viroids as the most rapidly evolving biological system known.

Base Sequence↗
PubMed1991

Exponential fit of QT interval-heart rate relation during exercise used to diagnose stress-induced myocardial ischemia.

The aim of this study was to analyze the dynamic changes of QT interval--heart rate relation during exercise, fitting their reciprocal variations to an exponential formula (QT = A - B.exp(-k.RR], in order to see whether diagnostic contributions might so be derived. The authors studied 139 patients who underwent a simultaneous assessment of regional myocardial perfusion and ventricular function by means of two injections of 99mTc-methoxy-isobutyl-isonitrile at rest and at peak of a submaximal exercise test, using first pass radionuclide angiography with multielement gamma-camera and single photon emission computerized tomography, in order to detect and localize the presence of stress-induced myocardial ischemia. According to radionuclide results, patients were divided into three groups: group A, 7 individuals with no sign of stress-induced myocardial ischemia; group B, 79 patients with evidence of ischemia in 1 (16.5%), 2 (65.5%), or 3 (17.7%) main coronary territories; and group C, 53 patients with previous infarction and evidence of ischemia in other territories. Conventional analysis of the exercise test (greater than or equal to 0.1 mV ST depression) showed a pathological response in no individual of group A, in 34 patients of group B (43%), and in 27 patients of group C (50.9%); overall sensitivity was 46.2%, specificity 100%, and diagnostic accuracy 48.9%. Exponential coefficients A, B, and k showed wide overlap of values among the three groups, although a significant difference was present in mean k values between groups A and B (p less than 0.001), and group C (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed2006

Two steps forward and one step back? Australian secondary students' sexual health knowledge and behaviors 1992-2002.

PURPOSE: To report on changes in the sexual health knowledge and sexual and risk behaviors of year 10 and 12 Australian school students between 1992 and 2002. METHODS: Surveys were administered at five yearly intervals to a total of 6781 students in 263 government secondary schools in all Australian states and territories. RESULTS: Analysis of data from the three survey administrations shows high levels of knowledge concerning human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS), but a small but consistent decline since 1992. Knowledge about sexually transmitted infections and hepatitis remains poor. In 2002, there was an increase in the number of students reporting ever having had sexual intercourse, and this was most pronounced for year 10 students. The number of young men in year 10 who reported having three or more partners had doubled since 1997 to 33%. More year 10 young women also reported having intercourse with three or more partners. Consistency of condom use has improved over time; however, 39% still report condom use only sometimes. CONCLUSION: School-based sexual health education provides a critical basis for ensuring that young people begin to experience sex safely and with an appropriate knowledge base.

Adolescent↗
PubMed1997

Chemical communication, aggression, and conspecific recognition in the fish Nile tilapia.

The chemical modulation of agonistic behavior and conspecific recognition were tested in juveniles of the fish Nile tilapia, Oreochromis niloticus (L.). After a 7-day isolation period, the fish were grouped (four individuals per aquarium) for 7 days. Then fish of alpha and beta ranks (previously matched for similar size) were paired in a neutral territory for analysis of their agonistic interaction. Pairs composed of alpha and beta fish were established with either fish from the same group (familiar) or from two different groups (unfamiliar). The pairs were tested in contiguous compartments, either with water exchange between the compartments or in the absence of water exchange. In each condition the fish were separated by a transparent glass partition. Twelve pairs were tested in each experimental condition. Fish behavior was videotaped and the following variables were analyzed: (a) frequency of and time spent in agonistic patterns, (b) latency to start fighting, and (c) duration of swimming. Water exchange between compartments decreased agonistic interactions. This effect, however, was more pronounced in pairs of fish coming from the same group (in this case, subordinate fish spent less time in confrontations than dominant ones). We conclude that chemical communication decreases aggression in this species by (1) inducing an alarm reaction and (2) increasing conspecific recognition (thus stabilizing the dominance hierarchy).

Aggression↗
PubMed2026

Temporal Trends and Spatial Variation in Preterm Prelabour Rupture of Membranes: A Population-Based Study.

OBJECTIVE: To describe the temporal trends in Preterm prelabour rupture of membranes (PPROM) in metropolitan France and the geographical distribution at the administrative division level. DESIGN: Exploratory population-based study using administrative data of the French National Health Data System. SETTING: Metropolitan France, 2015 to 2023. POPULATION: Pregnancy with a diagnosis of PROM before 37 SA. METHODS: Annual crude incidence of PPROM was calculated by dividing the number of pregnancies with PPROM diagnosis by the number of live births recorded during the same period. Annual trend was estimated by a binomial negative mixed model. Smoothed standardised incidence ratios were estimated based on a BYM2 model, which accounts for spatial variability between departments. MAIN OUTCOME: PPROM cases, defined as pregnancies with first hospitalizations with a diagnosis of PROM before 37 weeks. RESULTS: Over the study period, we included 150 615 PPROM cases representing 16 735 (±596) per year. Incidence of PPROM cases showed an ascending trend over time (incidence rate ratio 1.023 per year; 95% CI: 1.017-1.030) with an annual crude incidence ranging from 2.2% in 2015 to 2.7% in 2023. A decrease in the incidence was observed in 2020 relative to other years (incidence rate ratio 0.903, 95% CI: 0.887-0.920). A map of smoothed SIRs of PPROM cases at the French administrative division level revealed geographical inequalities. CONCLUSIONS: This first population-based study describing PPROM cases in metropolitan France paves the way for further studies to explore environmental hypotheses. Identifying temporal and geographical disparities in PPROM incidence is relevant to public health policy and practice as such disparities argue for the development of targeted prevention strategies in high-risk areas.

French national health data system↗
PubMed1984

Normal haematological and biochemical values for the swamp buffalo (Bubalus bubalis) in Australia.

Blood samples were collected from 24 immature male, 55 immature female and 99 mature female water buffalo kept at an experimental farm in the Northern Territory. Haematological analysis was performed on blood collected in dipotassium--ethylene diamine tetra acetic acid while biochemical analysis was performed on serum and plasma (for glucose) samples. Haematological values of mature buffalo were similar to those recorded for swamp buffalo in Malaysia. Blood cell appearances were similar to those reported for adult Indian river buffalo though values recorded for red cell components were higher. Statistical analysis revealed no significant differences between immature male and female buffalo. Red cell components, eosinophils, total plasma and serum proteins, albumin, gamma globulins, inorganic phosphate and the enzyme gamma-glutamyl transferase were significantly higher for mature female buffalo when compared to immature females. Reasons for the differences were not fully determined but the effect of age and nutritional status in combination with a variable period of domestication were considered.

Age Factors↗
PubMedDate not supplied

[5-fluorouracil and colorectal tumors: use in clinical practice and the "MISURA" project].

5-fluorouracil, an antimetabolite inhibiting timidilate synthetase, is one of the most used drugs in the treatment of many solid tumor types. In particular it is still central in the treatment of colorectal cancer. Nevertheless 5-FU efficiency is limited, this is due to the rapidity of its metabolism (T1/2 10 min). Many attempts have been done to increase its efficiency: 1) combinations with other antitumor drugs have been tested, but no one showed improved response rates with respect to 5-FU alone; 2) use of biological modifiers such as folinic acid and methotrexate. They interact with the biological actions of 5-FU improving its therapeutic effects. These combinations appear to be more effective than 5-FU alone; 3) continuous infusion increases the percentage of susceptible tumor cells, it makes possible the use of a high intensity dose which is active in patients resistant to 5-FU administered as bolus-injection. There are many schedules and methods of administration of 5-FU in the treatment of CRC, each of them showing different types of toxicities. This explains why there is the need to obtain a profile of 5-FU in clinical practice. The project called MISURA is though to give us this kind of information. It will be a collection of data regarding patients affected by colorectal cancer and treated with 5-FU. The collected information will be about diagnosis; ways of use, schedules, doses and tolerability of the drug; obtained responses. The aims of the study are: 1) to evaluate the use of 5-FU in clinical practice; 2) to collect data about the use of supportive therapy; 3) to know the effective incidence and prevalence of CRC in Italy. The study is retrospective, the sample consists of all patients from the oncological departments chosen to represent the national territory. The analysis of the data will be descriptive.

Antimetabolites, Antineoplastic↗
PubMed2001

Evidence for medial/lateral specification and positional information within the presomitic mesoderm.

In the vertebrate embryo, segmentation is built on repetitive structures, named somites, which are formed progressively from the most rostral part of presomitic mesoderm, every 90 minutes in the avian embryo. The discovery of the cyclic expression of several genes, occurring every 90 minutes in each presomitic cell, has shown that there is a molecular clock linked to somitogenesis. We demonstrate that a dynamic expression pattern of the cycling genes is already evident at the level of the prospective presomitic territory. The analysis of this expression pattern, correlated with a quail/chick fate-map, identifies a 'wave' of expression travelling along the future medial/lateral presomitic axis. Further analysis also reveals the existence of a medial/lateral asynchrony of expression at the level of presomitic mesoderm. This work suggests that the molecular clock is providing cellular positional information not only along the anterior/posterior but also along the medial/lateral presomitic axis. Finally, by using an in vitro culture system, we show that the information for morphological somite formation and molecular segmentation is segregated within the medial/lateral presomitic axis. Medial presomitic cells are able to form somites and express segmentation markers in the absence of lateral presomitic cells. By contrast, and surprisingly, lateral presomitic cells that are deprived of their medial counterparts are not able to organise themselves into somites and lose the expression of genes known to be important for vertebrate segmentation, such as Delta-1, Notch-1, paraxis, hairy1, hairy2 and lunatic fringe.

Animals↗
PubMed1992

Exercise thallium-201 tomographic scintigraphy in the diagnosis of coronary artery disease: emphasis on the effect of exercise level.

Exercise thallium-201 imaging using single-photon emission computed tomography (SPECT) was evaluated in 154 patients with angiographically documented coronary artery disease (CAD) and in 25 normal subjects. Of the 154 patients with CAD, 134 (87%) had abnormal thallium images. By contrast, only 77 (50%) patients had ischemic ST-segment depression (p < 0.001). Among 25 normal subjects, 20 had normal exercise SPECT images. The specificity of exercise SPECT imaging (80% or 20/25) in excluding patients with CAD was not significantly higher than that of exercise electrocardiography (76% or 19/25). For the detection of individual vessel involvement by analysis of territories of perfusion abnormalities, the sensitivity and specificity of exercise SPECT were 72% and 96% for the left anterior descending, 78% and 85% for the right coronary, and 47% and 98% for the left circumflex artery. Ninety (group 1) of the 154 patients with CAD achieved adequate exercise end points (ischemic ST-segment depression or > 85% of maximal predicted heart rate) and 64 (group 2) did not. Exercise SPECT showed significantly more perfusion abnormalities in group 1 than in group 2 (96% vs 75%, p < 0.001). We conclude that: (1) exercise SPECT thallium imaging is more sensitive than exercise electrocardiography for detecting patients with CAD; (2) the sensitivity of the test is affected by the level of exercise; and (3) it is valuable in the identification of individual vessel involvement.

Coronary Disease↗