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At least 343 records · Page 19Linked to original sources
PubMed1997

Transcription initiation sites and promoter structure of the mouse type 2 inositol 1,4,5-trisphosphate receptor gene.

Transcription initiation sites and the promoter sequence of the ubiquitously expressed mouse type 2 inositol 1,4,5-trisphosphate receptor (IP3R2) gene were determined. In contrast to the nervous system-enriched IP3R1, the IP3R2 gene had multiple (seven major) transcription initiation sites located 334 to 269 bp upstream from the first ATG codon. Transient luciferase assay revealed promoter activity of the IP3R2 sequence upstream from the transcription initiation sites. The IP3R2 promoter was GC-rich and had no conventional TATA box, but had a GC box in the proximal promoter. Multiple transcription start sites were flanked by CpG islands, and various cis elements were located in the promoter. These structural features are considered to be responsible for a profile of IP3R2 gene expression.

Animals↗
PubMed1991

[The effects of furcation morphology on periodontal disease].

Enamel spurs projecting from the cemento-enamel junction into the furcation as well as small islands and droplets of enamel deposited on furcational root surfaces are characteristic morphological features of human maxillary and mandibular molars. The furrows and recesses created by these structures form pathways for bacterial invasion and predispose for local periodontitis. Furthermore, the furcations are often covered by thick central cementum ridges, with steplike or tongue-like deepenings around enamel droplets. In the cementum, there is a variable number of small and large openings, representing either cementum-inherent channels or large open connections between pulp chamber and furcation. These structures offer ample opportunities for uncontrollable bacterial retention and colonisation, and the possibility for pulpal infections to spread into the furcation. The literature covering these issues is summarized.

Dental Cementum↗
PubMedDate not supplied

The head circumference growth curve for Japanese children between 0-4 years of age: comparison with Caucasian children and correlation with stature.

Controversy exists regarding possible international and interracial differences in head circumferences of children. We undertook the present study in order to see if there was a difference in head circumference between Japanese and Caucasian children. The subjects consisted of a total of 42,392 Japanese children between 0 and 4 years of age surveyed from 1940 to 1980, and these data were compared with those of American and British children. We conclude that there is a significant ethnic difference in head circumference, as large as one channel of usual percentiles, between Japanese and Caucasian children. The results indicate that smaller head circumference in Japanese children primarily reflects smaller stature of the Japanese.

Cephalometry↗
PubMed2006

Preliminary evaluation of the use of a CDMA-based emergency telemedicine system.

We have conducted a preliminary evaluation of the use of a code division multiple access (CDMA)-based emergency telemedicine system to be used by emergency rescuers providing first-aid treatment for patients. The prototype system included five instrumentation modules for measuring non-invasive arterial blood pressure (NIBP), arterial oxygen saturation (SpO(2)), six-channel electrocardiogram (ECG), blood glucose concentration and body temperature. The patient data were transferred to a doctor's PC through CDMA and TCP/IP networks using an embedded personal digital assistant (PDA) phone. Performance tests in the laboratory showed that the system provided reliable values with error ranges within +/-1% for heart rate, +/-5 mmHg for NIBP, +/-2% for SpO(2) and +/-1% for glucose. The feasibility of the prototype system was then evaluated with 15 real emergency patients on Jeju Island over a two-month period. Measured data were transmitted from a moving ambulance to the emergency medical centre without significant CDMA connection loss or transmission errors. The average transfer time was 8 min. Four emergency doctors and 11 rescuers completed a questionnaire. There were favourable reviews from the users.

Cell Phone↗
PubMed2006

Epigenetic allele silencing unveils recessive RYR1 mutations in core myopathies.

Epigenetic regulation of gene expression is a source of genetic variation, which can mimic recessive mutations by creating transcriptional haploinsufficiency. Germline epimutations and genomic imprinting are typical examples, although their existence can be difficult to reveal. Genomic imprinting can be tissue specific, with biallelic expression in some tissues and monoallelic expression in others or with polymorphic expression in the general population. Mutations in the skeletal-muscle ryanodine-receptor gene (RYR1) are associated with malignant hyperthermia susceptibility and the congenital myopathies central core disease and multiminicore disease. RYR1 has never been thought to be affected by epigenetic regulation. However, during the RYR1-mutation analysis of a cohort of patients with recessive core myopathies, we discovered that 6 (55%) of 11 patients had monoallelic RYR1 transcription in skeletal muscle, despite being heterozygous at the genomic level. In families for which parental DNA was available, segregation studies showed that the nonexpressed allele was maternally inherited. Transcription analysis in patients' fibroblasts and lymphoblastoid cell lines indicated biallelic expression, which suggests tissue-specific silencing. Transcription analysis of normal human fetal tissues showed that RYR1 was monoallelically expressed in skeletal and smooth muscles, brain, and eye in 10% of cases. In contrast, 25 normal adult human skeletal-muscle samples displayed only biallelic expression. Finally, the administration of the DNA methyltransferase inhibitor 5-aza-deoxycytidine to cultured patient skeletal-muscle myoblasts reactivated the transcription of the silenced allele, which suggests hypermethylation as a mechanism for RYR1 silencing. Our data indicate that RYR1 undergoes polymorphic, tissue-specific, and developmentally regulated allele silencing and that this unveils recessive mutations in patients with core myopathies. Furthermore, our data suggest that imprinting is a likely mechanism for this phenomenon and that similar mechanisms could play a role in human phenotypic heterogeneity.

Alleles↗
PubMed2002

Corepressor-dependent silencing of chromosomal regions encoding neuronal genes.

The molecular mechanisms by which central nervous system-specific genes are expressed only in the nervous system and repressed in other tissues remain a central issue in developmental and regulatory biology. Here, we report that the zinc-finger gene-specific repressor element RE-1 silencing transcription factor/neuronal restricted silencing factor (REST/NRSF) can mediate extraneuronal restriction by imposing either active repression via histone deacetylase recruitment or long-term gene silencing using a distinct functional complex. Silencing of neuronal-specific genes requires the recruitment of an associated corepressor, CoREST, that serves as a functional molecular beacon for the recruitment of molecular machinery that imposes silencing across a chromosomal interval, including transcriptional units that do not themselves contain REST/NRSF response elements.

Animals↗
PubMed2003

The expression of the tumor suppressor gene connexin 26 is not mediated by methylation in human esophageal cancer cells.

Gap junctional intercellular communication is thought to play an important role in cell differentiation and tissue homeostasis. Gap junctional intercellular communication is mediated by intercellular channels connecting adjacent cells and composed of connexin (Cx) proteins. Until now, approximately 20 different Cx have been characterized in mammals, and they are expressed in a tissue-specific manner. The downregulation of Cx expression is often observed in tumors and transformed cell lines and is believed to contribute to the loss of proliferating control. Connexin 26 (Cx26) is a Cx constitutively expressed in the normal epithelial esophageal tissue. In the majority of esophageal tumors, Cx26 expression is low or totally absent. CpG island hypermethylation is known to be associated with gene silencing in cancer. Because the promoter and exon 1 region of Cx26 are rich in CpG dinucleotides, we examined whether the loss of Cx26 expression in human esophageal TE cell lines was related to the hypermethylation of this region. We analyzed several TE cell lines derived from different human esophageal carcinomas and exhibiting different levels of Cx26 expression by using methylation-sensitive restriction digestion and Southern blot analysis. We did not find any correlation between the Cx26 expression and the methylation level of the promoter region of the Cx26 gene. Our results suggest that methylation was probably not involved as a primary mechanism of Cx26 regulation in human esophageal cancer cell lines.

Connexin 26↗
PubMed2005

An unusual distribution of the kdr gene among populations of Anopheles gambiae on the island of Bioko, Equatorial Guinea.

In West Africa, Anopheles gambiae exists in discrete subpopulations known as the M and S molecular forms. Although these forms occur in sympatry, pyrethroid knock-down resistance (kdr) is strongly associated with the S molecular form. On the island of Bioko, Equatorial Guinea we found high frequencies of the kdr mutation in M form individuals (55.8%) and a complete absence of kdr in the S form. We also report the absence of the kdr allele in M and S specimens from the harbour town of Tiko in Cameroon, representing the nearest continental population to Bioko. The kdr allele had previously been reported as absent in populations of An. gambiae on Bioko. Contrary to earlier reports, sequencing of intron-1 of this sodium channel gene revealed no fixed differences between M form resistant and susceptible individuals. The mutation may have recently arisen independently in the M form on Bioko due to recent and intensive pyrethroid application.

Animals↗
PubMed1998

Frequency analysis of autosomal dominant cerebellar ataxias in Japanese patients and clinical characterization of spinocerebellar ataxia type 6.

Using a molecular diagnostic approach, we investigated 101 kindreds with autosomal dominant cerebellar ataxias (ADCAs) from the central Honshu island of Japan, including spinocerebellar ataxia type 1 (SCA1), spinocerebellar ataxia type 2 (SCA2), Machado-Joseph disease (MJD), dentatorubral and pallidoluysian atrophy (DRPLA) and spinocerebellar ataxia type 6 (SCA6). In our unselected series, MJD was the most common type of ADCA, accounting for 33.7% followed by DRPLA (19.8%), SCA2 (5.9%) and SCA6 (5.9%). No SCA1 mutations were identified. We analysed the clinical features of six molecular confirmed SCA6 kindreds: in each family, there was an expanded allele in the alpha1A-voltage dependent calcium channel comprising between 23 and 25 CAG repeats. The mean age at onset of symptoms was 43+/-13 years. The clinical features consisted predominantly of cerebellar ataxia, dysarthria and horizontal nystagmus, which was generally consistent with ADCA type 3. However several new clinical features were found in some patients: dramatic anticipation, rapid disease progression, severe ataxia associated with action tremor or action myoclonus, and very early onset, which are not described as the classical features of ADCA type 3.

Adult↗
PubMed2000

Genetic analysis of the ycgJ-metB-cysK-ygaG operon negatively regulated by the VirR/VirS system in Clostridium perfringens.

The 5'-flanking region of the metB-cysK-ygaG operon, whose expression is negatively regulated by the VirR/VirS system in C. perfringens, was analyzed. The region contained the ycgJ, mscL, and colA genes encoding a hypothetical protein, a large conductance mechanosensitive channel protein, and kappa-toxin (collagenase), respectively. Northern analysis revealed that the ycgJ gene was transcribed as a 4.9-kb operon together with the metB-cysK-ygaG genes and that this operon was negatively regulated by the VirR/VirS system. It is indicated that the pfoA (theta-toxin or perfringolysin O), colA, and ycgJ-metB-cysK-ygaG genes that belong to the VirR/VirS regulon are situated very close together in a 26.5-kb region of the chromosome, but do not form a pathogenic island.

Bacterial Proteins↗
PubMed2005

Home health care nurses as a new channel for smoking cessation treatment: outcomes from project CARES (Community-nurse Assisted Research and Education on Smoking).

BACKGROUND: Clinical guidelines for smoking cessation may not be sufficient for helping some subgroups of smokers quit. Incorporating smoking cessation into home-based medical care can proactively reach high-risk smokers who may not have access to (or spontaneously seek) smoking cessation. METHOD: Home health care nurses (N = 98) were randomly assigned to deliver either Motivational Enhancement (ME; Motivational Interviewing + Carbon Monoxide Feedback) or Standard Care (AHCPR Guidelines for smoking cessation) to their patients. Seventy percent of patients were eligible and willing to participate (N = 273; 54% female, mean age = 57 years, 83% Caucasian, 41% < high school education). The study was conducted in Providence, RI, USA from 1998 to 2003. RESULTS: Biochemically verified continuous abstinence rates at the 12-month follow-up were 4.2% (SC) and 8.7% (ME) for intent to treat analyses, and 5.2% (SC) and 11.8% (ME) using all available cases (P > 0.05). ME reported more quit attempts and significantly greater reductions in the number of cigarettes smoked per day at all follow-ups through 12 months of post-treatment (all P values < 0.05). CONCLUSIONS: Use of an existing public health channel such as home health care to reach smokers who vary in their motivation to quit could have the potential for large public health impact.

Adult↗
PubMed1997

Enzyme-histochemical study on postnatal development of rat stomach lymphatic vessels.

Postnatal development of rat gastric lymphatics was studied by an enzyme-histochemical method to elucidate the morphological changes of lymphatics and their relationship to maturation and function, especially in the glandular portion. The significant features of 5'-Nase-positive lymphatics in distribution and structure were examined in different stages (within 24 hr, 4-21 days, and 2 months). Lymphatics in the greater curvature and anterior wall grew much slower than those in the lesser curvature and posterior wall of the stomach in newborn and infant rats. Lymphatic islands isolated from the primary lymphatic networks in the submucosa and subserosa underwent a morphological change during this early period. This is considered one of the basic steps in lymphatic development. Occurrence of lymphatic networks in the deep lamina propria indicates that development in the gastric wall is well characterized from Day 10. With further growth and modification of lymphatics, the networks in the different layers formed an extensive communication network and many lymphatic valves were found in the submucosa and subserosa. Pinocytotic vesicles, open junctions, and intraendothelial channels were frequently detected in the mucosal and submucosal lymphatic networks of the corpus-antrum and antrum-duodenum divisional zones in the adult rats. These findings suggest that developing lymphatics in the rat stomach may represent rapidly growing tissue not only with high 5'-Nase activity but also with high adaptability for future physiological demands.

5'-Nucleotidase↗
PubMed1999

Lead suit: an immodest proposal.

Rhode Island's Attorney General Whitehorse has announced that Rhode Island will sue the lead paint industry for its contribution to the epidemic of health problems caused by lead paint. The suit asserts that the paint industry was negligent because it marketed a harmful product; since it caused the problem, it should contribute to paying for it. We need a lead trust fund to provide for primary abatement upkeep and maintenance of housing. The attorney general's action can, if successful, help implement such a fund. Personal lead injury cases, which have a minimal public health impact, can be channeled to do so. Whenever personal injury cases are settled--either through negotiated settlement or full jurisprudence--a percentage of the settlement could be earmarked for a public lead trust fund.

Journal Article↗
PubMed2001

Ultrafast source-to-surface movement of melt at island arcs from 226Ra-230Th systematics.

Island arc lavas have radium-226 excesses that extend to higher values than those observed in mid-ocean ridge or ocean island basalts. The initial ratio of radium-226 to thorium-230 is largest in the most primitive lavas, which also have the highest barium/thorium ratios, and decreases with increasing magmatic differentiation. Therefore, the radium-226 excesses appear to have been introduced into the base of the mantle melting column by fluids released from the subducting plate. Preservation of this signal requires transport to the surface arguably in only a few hundreds of years and directly constrains the average melt velocity to the order of 1000 meters per year. Thus, melt segregation and channel formation can occur rapidly in the mantle.

Journal Article↗
PubMed2002

Spiders of medical importance in the Asia-Pacific: atracotoxin, latrotoxin and related spider neurotoxins.

1. The spiders of medical importance in the Asia-Pacific region include widow (family Theridiidae) and Australian funnel-web spiders (subfamily Atracinae). In addition, cupboard (family Theridiidae) and Australian mouse spiders (family Actinopodidae) may contain neurotoxins responsible for serious systemic envenomation. Fortunately, there appears to be extensive cross-reactivity of species-specific widow spider antivenom within the family Theridiidae. Moreover, Sydney funnel-web antivenom has been shown to be effective in the treatment of mouse spider envenomation. 2. alpha-Latrotoxin (alpha-LTx) appears to be the main neurotoxin responsible for the envenomation syndrome known as "latrodectism" following bites from widow spiders. This 120 kDa protein binds to distinct receptors (latrophilin 1 and neurexins) to induce neurotransmitter vesicle exocytosis via both Ca2+-dependent and -independent mechanisms, resulting in vesicle depletion. This appears to involve disruption to a process that normally inhibits vesicle fusion in the absence of Ca2+. Precise elucidation of the mechanism of action of alpha-LTx will lead to a major advancement in our understanding of vesicle exocytosis. 3. delta-Atracotoxins (delta-ACTX) are responsible for the primate-specific envenomation syndrome seen following funnel-web spider envenomation. These peptides induce spontaneous repetitive firing and prolongation of action potentials in excitable cells. This results from a hyperpolarizing shift of the voltage-dependence of activation and a slowing of voltage-gated Na+ channel inactivation. This action is due to voltage-dependent binding to neurotoxin receptor site-3 on insect and mammalian voltage-gated Na+ channels in a manner similar, but not identical, to scorpion alpha-toxins and sea anemone toxins. delta-Atracotoxins provide us with highly specific tools to study Na+ channel structure and function 4. omega- and Janus-faced ACTX, from funnel-web spider venom, are novel neurotoxins that show selective toxicity to insects. In particular omega-ACTX define a new insecticide target due to a specific action to block insect voltage-gated Ca2+ channels. Both these ACTX show promise for the development of baculoviral recombinant biopesticides expressing these toxins for the control of insecticide-resistant agricultural pests. In addition, they should provide valuable tools for the pharmacological and structural characterization of insecticide targets.

Amino Acid Sequence↗
PubMed2000

Identification of the gene causing mucolipidosis type IV.

Mucolipidosis type IV (MLIV) is an autosomal recessive, neurodegenerative, lysosomal storage disorder characterized by psychomotor retardation and ophthalmological abnormalities including corneal opacities, retinal degeneration and strabismus. Most patients reach a maximal developmental level of 12?15 months. The disease was classified as a mucolipidosis following observations by electron microscopy indicating the lysosomal storage of lipids together with water-soluble, granulated substances. Over 80% of the MLIV patients diagnosed are Ashkenazi Jews, including severely affected and mildly affected patients. The gene causing MLIV was previously mapped to human chromosome 19p13.2-13.3 in a region of approximately 1 cM (ref. 7). Haplotype analysis in the MLIV gene region of over 70 MLIV Ashkenazi chromosomes indicated the existence of two founder chromosomes among 95% of the Ashkenazi MLIV families: a major haplotype in 72% and a minor haplotype in 23% of the MLIV chromosomes (ref. 7, and G.B., unpublished data). The remaining 5% are distinct haplotypes found only in single patients. The basic metabolic defect causing the lysosomal storage in MLIV has not yet been identified. Thus, positional cloning was an alternative to identify the MLIV gene. We report here the identification of a new gene in this human chromosomal region in which MLIV-specific mutations were identified.

Amino Acid Sequence↗
PubMed1999

Mercury contamination associated with artisanal gold mining on the island of Mindanao, the Philippines.

The Agusan River basin of eastern Mindanao, the Philippines, hosts several centres of artisanal gold mining, the most important of which, Diwalwal, is a significant gold producer in global terms. An investigation of the environmental impacts of artisanal mining in the Agusan system, with particular reference to mercury contamination, was initiated in 1995 following reports of several incidents of human Hg poisoning in the province of Davao del Norte. Results show drainage downstream of Diwalwal is characterised by extremely high levels of Hg both in solution (maximum 2906 micrograms/l) and in bottom sediments (> 20 mg/kg). Filtered surface water Hg levels exceed the WHO Drinking Water guideline and the US-EPA Water Quality Criteria for the Protection of Aquatic Life for a downstream distance of more than 14 km, including channel sections utilised for fishing and potable water supply. The Environment Canada sediment quality Hg Toxic Effect Threshold for the Protection of Aquatic Life is exceeded for a downstream distance of 20 km. Hair Hg data indicate that ballmill and CIP plant operators processing Hg contaminated tailings at eastern Mindanao's principal gold beneficiation centre, Apokon, may be subject to enhanced occupational Hg exposure. It appears that the wider population of this area has not been affected.

Geologic Sediments↗
PubMed2000

Hypermethylation of multiple genes in pancreatic adenocarcinoma.

Hypermethylation of CpG islands is a common mechanism by which tumor suppressor genes are inactivated. We studied 45 pancreatic carcinomas and 14 normal pancreata for aberrant DNA methylation of CpG islands of multiple genes and clones using methylation-specific PCR (MSP) and bisulfite-modified sequencing. Using MSP, we detected aberrant methylation of at least one locus in 60% of carcinomas. The genes analyzed included RARbeta (methylated in 20%), p16 (18%), CACNA1G (16%), TIMP-3 (11%), E-cad (7%), THBS1 (7%), hMLH1 (4%), DAP kinase (2%), and MGMT (0%). In addition, aberrant methylation was found in three CpG islands (MINT31, -1, and -2) in 38, 38, and 14% of carcinomas, respectively. Hypermethylation was largely confined to the carcinomas with only three loci (E-cad, DAP kinase, and MINT2) harboring methylation in some normal pancreata (36, 21, and 14%, respectively). Simultaneous methylation of at least four loci was observed in 5 of 36 (14%) pancreatic adenocarcinomas. We defined this subgroup of pancreatic adenocarcinomas as "CpG island-methylator-phenotype positive (CIMP+)." Two of four carcinomas with microsatellite instability harbored promoter hypermethylation of hMLH1, and both cases were CIMP+. Thus, we conclude that many pancreatic carcinomas hypermethylate a small percentage of genes, whereas a subset displays a CIMP+ phenotype.

Adenocarcinoma↗