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At least 991 records · Page 55Linked to original sources
PubMed2005

Genetic variation at the ACE gene is associated with persistent microalbuminuria and severe nephropathy in type 1 diabetes: the DCCT/EDIC Genetics Study.

The development and progression of microvascular complications have been extensively documented in a cohort of type 1 diabetic subjects enrolled in the Diabetes Control and Complications Trial (DCCT) and followed in the Epidemiology of Diabetes Interventions and Complications (EDIC) study. We describe the association of genetic variation in the ACE gene in 1,365 DCCT/EDIC subjects with incident persistent microalbuminuria (n = 312) and severe nephropathy (n = 115). We studied three markers (rs1800764, insertion/deletion, and rs9896208) in the ACE gene that allowed us to capture genetic variation in the common haplotypes occurring at frequencies of >5% in Caucasians. Compared with the more frequent genotype (D/I) for the insertion/deletion polymorphism, in multivariate models, the I/I genotype conferred a lower risk for persistent microalbuminuria (hazard ratio [HR] 0.62 [95% CI 0.43-0.89], P = 0.009) and severe nephropathy (0.56 [0.32-0.96], P = 0.033). Variation at the two other markers, rs1800764 and rs9896208, were also associated with these renal outcomes. In addition, homozygosity for the common haplotype TIC (which corresponded to the T, insertion, and C alleles at the three markers, rs1800764, insertion/deletion, and rs9896208, respectively) versus the CDT/TIC haplotype pair was associated with lower risk for development of persistent microalbuminuria (HR 0.49 [0.32-0.75], P = 0.0009) and severe nephropathy (0.41 [0.22-0.78], P = 0.006). Our findings in the DCCT/EDIC cohort provide strong evidence that genetic variation at the ACE gene is associated with the development of nephropathy in patients with type 1 diabetes.

Albuminuria↗
PubMed1991

Hepatitis E virus genome. Molecular features, expression of immunoreactive proteins and sequence divergence.

The strategy for molecular cloning of hepatitis E virus (HEV), the major etiologic agent of enterically-transmitted non-A, non-B hepatitis, is briefly described. The organization of the HEV genome is discussed and compared to those of two other vertebrate viruses that contain single-stranded, positive-sense, polyadenylated RNA genomes with three overlapping ORFs. Serologic cross-reactivity of expressed proteins and genetic divergence of HEV isolates are also described within the context of sequence variation, type-common epitopes, and type-specific epitopes.

Cloning, Molecular↗
PubMed2001

Determinant factors of pain after ambulatory inguinal herniorrhaphy: a multi-variate analysis.

Pain is common after inguinal herniorrhaphy. The objective of our study was to evaluate the significance of various clinical factors on the level of post-operative pain after ambulatory inguinal herniorrhaphy. Between January, 1996 and December, 1998, 239 ambulatory inguinal hernia repair patients were recruited. Operative techniques included nylon darn (n = 152), modified Bassini repair (n = 56), and prolene mesh hernioplasty (n = 30). Linear analogue pain scores--ranging in value from 0 to 10--were assessed by telephone interviews on the first and third post-operative days. Uni-variate and multi-variate analyses were performed to identify the significant independent determinant factors affecting the severity of post-operative pain. Clinical factors studied were age, sex, operative technique, hernia anatomy and post-operative complication(s). By uni-variate analysis, patients of age < or = 50 years and indirect inguinal hernia were associated with a significantly higher pain score on the first postoperative day 1. On post-operative day 3, patients of age < or = 50 years, with an indirect inguinal hernia and modified Bassini repair reported a significantly higher pain score. Following inguinal herniorrhaphy, multiple regression analysis showed that age was the only independent predictive factor of pain score on post-operative days 1 and 3. In conclusion, post-operative pain was not affected by surgical technique, sex, hernia anatomy and post-operative morbidity. Only age had a significant influence on the post-operative pain score following ambulatory inguinal herniorrhaphy. Therefore, the age of a patient should be taken into consideration when prescribing post-operative analgesics.

Age Factors↗
PubMed2001

Hepatomesenteric trunk.

An hepatomesenteric trunk, formed by the common hepatic and superior mesenteric arteries, was found in a 50-year-old male cadaver. The left gastric and splenic arteries arose as a common trunk, the gastrosplenic trunk, from the abdominal aorta; no typical celiac trunk was present. In addition, the hepatomesenteric trunk passed posterior to the portal vein. A knowledge of variations of the common hepatic artery may be important in pancreaticoduodenectomy, as well as during hepatic artery infusion chemotherapy.

Arteries↗
PubMed2006

Capsular polysaccharide phase variation in Vibrio vulnificus.

Commonly found in raw oysters, Vibrio vulnificus poses a serious health threat to immunocompromised individuals and those with serum iron overload, with a fatality rate of approximately 50%. An essential virulence factor is its capsular polysaccharide (CPS), which is responsible for a significant increase in virulence compared to nonencapsulated strains. However, this bacterium is known to vary the amount of CPS expressed on the cell surface, converting from an opaque (Op) colony phenotype to a translucent (Tr) colony phenotype. In this study, the consistency of CPS conversion was determined for four strains of V. vulnificus. Environmental conditions including variations in aeration, temperature, incubation time, oxidative stress, and media (heart infusion or modified maintenance medium agar) were investigated to determine their influence on CPS conversion. All conditions, with the exception of variations in media and oxidative stress, significantly affected the conversion of the population, with high ranges of CPS expression found even within cells from a single colony. The global quorum-sensing regulators RpoS and AI-2 were also examined. While RpoS was found to significantly mediate phenotypic conversion, quorum sensing was not. Finally, 12 strains that comprise the recently found clinical (C) and environmental (E) genotypes of V. vulnificus were examined to determine their rates of population conversion. C-genotype strains, which are most often associated with infection, had a significantly lower rate of population conversion from Op to Tr phenotypes than did E-genotype strains (ca. 38% versus ca. 14%, respectively). Biofilm capabilities of these strains, however, were not correlated with increased population conversion.

Animals↗
PubMed2005

The contribution of genetic and environmental factors to quantitative variability of erythrocyte membrane proteins in primary hypotension.

Our previous studies have shown that, compared with healthy individuals, patients with primary arterial hypotension (PAH) have significant quantitative changes in erythrocyte membrane proteins. The purpose of the present study was to evaluate the contribution made by genetic and environmental factors to quantitative variation of erythrocyte membrane proteins in PAH. We studied 109 hypotensive patients, 124 normotensive subjects, 222 of their first-degree relatives and 24 twin pairs by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis. The decomposition of total phenotypic variance of erythrocyte membrane proteins to genetic and environmental components was performed on the basis of correlations among first-degree relatives by the least squares method. The genetic dominance and shared environmental factors were found to influence the variability of cytoskeletal membrane proteins whose contents were changed in PAH. Furthermore, variations in alpha-spectrin, actin and anion exchanger in hypotensives were substantially influenced by major gene and maternal effects. Ankyrin 2.1 and actin content was under the control of common underlying genes. Variations in membrane-associated glutathione-S-transferase and tropomyosin were predominantly affected by polygenes. These findings suggest that the putative major genes with pleiotropic effects appear to be involved in the control of quantitative disorders of erythrocyte membrane proteins in primary hypotension.

Actins↗
PubMed1982

Primary malignant tumors of bone: incidence in Ibadan, Nigeria.

An account of primary malignant bone tumors in Africans is presented in this series. The study analyzes 170 Nigerians with bone neoplasms diagnosed over the 17-year period 1960-1976. It accounted for 1.28 percent of tumors registered in the Cancer Registry of the University College Hospital, Ibadan. There were 119 male and 51 female patients, with ages ranging from 4 to 75 years. The most common symptom was painful swelling. Trauma was associated with this condition. The pattern of behavior of these tumors conforms with other reports in the literature, but it showed some geographical variations. The most common tumor in the series was osteosarcoma, although there was no association of Paget's disease, which is very rare in Nigerians. Attention is also called to the presence of osteolytic conditions in the metaphysical region of a long bone, which may be due to osteomyelitis caused by Histoplasma duboisii and which has been confused with a malignant bone tumor in this environment.

Adolescent↗
PubMed1999

Structural modules in actin-binding proteins: towards a new classification.

The number of actin binding proteins for which (part of) the three-dimensional structure is known, is steadily increasing. This has led to a picture in which defined structural modules with actin binding capacity are shared between different actin binding proteins. A classification of these based on their common three-dimensional modules appears a logical future step and in this review we provide an initial list starting from the currently known structures. The discussed cases illustrate that a comparison of the similarities and variations within the common structural actin binding unit of different members of a particular class may ultimately provide shortcuts for defining their actin target site and for understanding their effect on actin dynamics. Within this concept, the multitude of possible interactions by an extensive, and still increasing, list of actin binding proteins becomes manageable because they can be presented as variations upon a limited number of structural themes. We discuss the possible evolutionary routes that may have produced the present array of actin binding modules.

Actins↗
PubMed2006

Common celiaco-mesenterico-phrenic trunk and renal vascular variations.

The knowledge of vascular variations like other anatomical variations, is important during the operative, diagnostic, and endovascular procedures in abdomen. This report describes multiple variations in the upper abdominal vessels as found during the routine dissection in a 60-year-old male cadaver. The variations found were; presence of a celiaco-mesenterico-phrenic trunk, a common inferior phrenic trunk, 2 right renal arteries originating from abdominal aorta, 2 suprarenal arteries originating from the lower right renal artery, 3 right renal veins opening separately into inferior vena cava, and termination of right testicular vein into the lowest vein among the 3 right renal veins. The existence of a celiaco-mesenterico-phrenic trunk has not been reported yet. Although, other variations reported in this case exist as individual variations, a concomitant variation of them has not been reported yet. The knowledge of such variations is quite useful in planning any upper abdominal surgery.

Abnormalities, Multiple↗
PubMedDate not supplied

Control of protein topology at the endoplasmic reticulum.

I have described recent work that supports several conclusions that might not have been previously expected: first, that stop transfer, like the initiation of translocation, is receptor-mediated; second, that at least some of the topology-determining events at the ER membrane can be regulated (an example is provided where regulation may occur developmentally [PrP] and a possible example where receptor interactions for stop transfer seem to have been dissociated from those of integration in the membrane, in the course of evolution [apo B]); third, that these variations on the universal mechanism of eukaryotic secretory and transmembrane protein biogenesis can occur either through the variations in sequences presented to the common machinery of translocation or through variations in the machinery with which these sequences interact. Thus, on the one hand, at least some of these variations are directed by signal and stop transfer sequence subtypes and, on the other hand, in at least one case, a special cytoplasmic factor distinct from the core machinery for chain translocation also seems to be involved (RRL cytosolic factor effect on PrP topology) in the special handling of the STE stop transfer sequence subtype. In another case, the conserved universal machinery is engaged by a protein (apo B) to carry out an unusual, if not unique, mechanism presumably related to the lipid carrying role of this soluble secretory protein. Whether stop transfer sequence subtypes are involved here remains to be demonstrated, but it is a tempting hypothesis. Taken together, these findings suggest that the ER is more than a barrier to be overcome in protein export. In some cases, it plays a regulatory role in gene expression (e.g., alternate fates of PrP), and in other cases, it plays a role as a specialized assembly line for biogenesis of proteins with unusual properties. It seems likely that many other examples of proteins using these two mechanisms will be found, as well as entirely different variations on the mechanisms of protein biogenesis. A common conceptual theme is likely to be that they are all directed by discrete sequences within the particular newly synthesized proteins engaging both/either the common and/or distinctive component of the cellular machinery for protein biogenesis.

Animals↗
PubMed2000

Some thoughts on choosing a Z-plasty: the Z made simple.

The Z-plasty and its variations are techniques commonly performed in plastic surgery. However, there are few descriptions and comparisons of the various types of Z-plasty. This article examines the mechanics of the Z-plasty and its variations. Understanding the geometry of the different variations will allow selection of the most appropriate Z-plasty for contracture release.

Humans↗
PubMed1992

Restriction site generating-polymerase chain reaction (RG-PCR) for the probeless detection of hidden genetic variation: application to the study of some common cystic fibrosis mutations.

In this report we describe the use of a DNA amplification technique in which modified primers introduce a base substitution adjacent to the codon of interest and create an artificial restriction site for the detection of mutations which do not produce or modify a naturally occurring restriction site (restriction site generating-polymerase chain reaction, RG-PCR). RG-PCR was developed and applied to the screening in an Italian population sample of several relatively common cystic fibrosis mutations which are not amenable to analysis with a known restriction endonuclease: G542X, 2869insG, Y913C, N1303K, and 1717-1GA. This method, which allows the identification of virtually any single base change by restriction enzyme analysis and without the need for molecular probes, is rapid and easy to perform. The combined use of RG-PCR for several different CF mutations in multiplex tests further expands the advantages of this approach.

Base Sequence↗
PubMed1997

A possible role of NAIP gene deletions in sex-related spinal muscular atrophy phenotype variation.

Childhood SMAs are common neuromuscular disorders, due to the occurrence of large genomic deletions encompassing the SMN gene and often extending to involve the NAIP gene. Although NAIP deletions are more frequently observed in patients affected by the acute form of the disease, it is not possible to establish an unambiguous correlation between deletion size and clinical severity. We have investigated the effects of gender on the association between NAIP gene deletion and disease severity. NAIP deletions were screened in 197 Italian SMA patients lacking SMN; the results obtained were correlated with disease severity in male and female samples separately. No significant relationship between deletion size and clinical phenotype was observed among male subjects, whereas in females the absence of NAIP was strongly associated with a severe phenotype (p <0.0001). These results provide a possible molecular explanation for the sex-dependent phenotype variation observed in SMA patients.

Cyclic AMP Response Element-Binding Protein↗
PubMed2002

Genetic diversity of Pneumocystis carinii f. sp. hominis based on variations in nucleotide sequences of internal transcribed spacers of rRNA genes.

A variety of genes have been used to type Pneumocystis carinii. In the present study, nucleotide sequence variations in the ITS1 and ITS2 internal transcribed spacer (ITS) regions of the rRNA genes were used to type Pneumocystis carinii f. sp. hominis DNA obtained from the lungs of 60 human immunodeficiency virus-infected individuals. These regions were amplified by PCR, cloned, and sequenced. Multibase polymorphisms were identified among samples. Several new genotypes are reported on the basis of the nucleotide sequence variations at previously unreported positions of both the ITS1 and the ITS2 regions. Twelve new ITS1 sequences were observed, in addition to the nine sequence types reported previously. The most common was type E, which was observed in 60.5% of the samples. The sequence variations in the ITS1 region were mainly located at positions 5, 12, 23, 24, 45, 53, and 54. Sixteen new ITS2 types were also identified, in addition to the 13 types reported previously. The most common was type g (26.6%). The sequences of the ITS2 regions in most specimens were different from the previously published sequence at bases 120 and 166 through 183. The most common variations observed were deletions at positions 177 through 183. The presence of more than one sequence type in some patients (60%) suggested the occurrence of coinfection with multiple P. carinii strains. The genetic polymorphism observed demonstrates the degree of diversity of Pneumocystis strains that infect humans. Furthermore, the high degree of polymorphism suggests that these genes are evolving faster than other genes. Consequently, the sequence information derived is useful for purposes such as examination of the potential of person-to-person transmission and recurrent infections but perhaps not for other genotyping applications that rely on more stable genetic loci.

AIDS-Related Opportunistic Infections↗
PubMed1986

The stimulants and hallucinogens under consideration: a brief overview of their chemistry and pharmacology.

The substances under review are a heterogeneous set of compounds from a pharmacological point of view, though many have a common phenylethylamine structure. Variations in structure lead to marked changes in potency and characteristic action. The introductory material presented here is meant to provide a set of chemical and pharmacological highlights of the 28 substances under consideration. The most commonly used names or INN names, Chemical Abstract (CA) names and numbers, and elemental formulae are provided in the accompanying figures. This provides both some basic information on the substances and a starting point for the more detailed information that follows in the individual papers by contributors to the symposium.

Animals↗
PubMed1999

Molecular variation in Leymus species and populations.

Icelandic populations of European lymegrass [Leymus arenarius (L.) Hochst.] were examined using amplified fragment length polymorphism (AFLP) and restriction fragment length polymorphism (RFLP) of the major ribosomal genes (18S-5.8S-26S rDNA), in comparison with Alaskan populations of its closely related species L. mollis (Trin.) Pilger. The AFLP profiles emerged as two distinct entities, clearly separating the two species, and based on species-specific bands it was simple to distinguish these two morphologically similar species. The rDNA-RFLPs also differentiated the species. Within species, the Icelandic L. arenarius was more homogeneous than the Alaskan L. mollis, and its variation was dispersed over geographically different populations, suggesting a common gene pool. The variation among the Alaskan L. mollis was more extensive and its interrupted pattern may be the result of gene introgression at subspecies level. Within a 40-year-old population of L. mollis established in Iceland from Alaskan material, the molecular profiles separated old and new genotypes. Both AFLP and rDNA revealed the new genotypes to be extremely similar. This rapid change in allele frequency is thought to be the result of adaptation to a new environment.

Alaska↗
PubMed2000

Both naturally occurring insertions of transposable elements and intermediate frequency polymorphisms at the achaete-scute complex are associated with variation in bristle number in Drosophila melanogaster.

A restriction enzyme survey of a 110-kb region including the achaete scute complex (ASC) examined 14 polymorphic molecular markers in a sample of 56 naturally occurring chromosomes. Large insertions as a class were associated with a reduction in both sternopleural and abdominal bristle number, supporting deleterious mutation-selection equilibrium models for the maintenance of quantitative genetic variation. Two polymorphic sites were independently associated with variation in bristle number measured in two genetic backgrounds as assessed by a permutation test. A 6-bp deletion near sc alpha is associated with sternopleural bristle number variation in both sexes and a 3.4-kb insertion between sc beta and sc gamma is associated with abdominal bristle number variation in females. Under an additive genetic model, the small deletion polymorphism near sc alpha accounts for 25% of the total X chromosome genetic variation in sternopleural bristle number, and the 3.4 kb insertion accounts for 22% of the total X chromosome variation in female abdominal bristle number. The observation of common polymorphisms associated with variation in bristle number is more parsimoniously explained by models that incorporate balancing selection or assume variants affecting bristle number are neutral, than mutation-selection equilibrium models.

Animals↗
PubMed1994

The local distribution of highly divergent mitochondrial DNA haplotypes in toque macaques Macaca sinica at Polonnaruwa, Sri Lanka.

Surveys of mitochondrial DNA (mtDNA) variation in macaque monkeys have revealed extremely high levels of intraspecific divergence among haplotypes. One consistent pattern that has emerged from these studies is that divergent haplotypes are geographically segregated so that sampling a few matrilines from a given region shows them to be identical, or a closely related subset of haplotypes. Geographically structured mtDNA variation has also been commonly observed in other taxa. In this study, haplotype variation and distribution are studied in detail within a local population of toque macaques. The results show that highly divergent haplotypes, differing by 3.1% in their nucleotide sequences, coexist in this population and that they may be spatially segregated even on this micro-geographic scale. Furthermore, these differences are maintained between social groups that exchange male migrants, and thus nuclear genes, frequently.

Animals↗