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PubMedDate not supplied

Inheritance of two HFE mutations in African Americans: cases with hemochromatosis phenotypes and estimates of hemochromatosis phenotype frequency.

PURPOSE: Two unrelated African Americans had hemochromatosis phenotypes and genotypes. We sought to identify origins of their HFE mutations and estimate frequencies of similar cases. METHODS: HFE and HLA genotyping were performed in index cases and family members. HFE genotypes of 1,373 African American controls in five regions were tabulated. RESULTS: Index cases had C282Y/C282Y and C282Y/H63D, respectively; each corresponding Ch6p was likely of Caucasian origin. In controls, frequencies of hemochromatosis-associated genotypes were as follows: C282Y/C282Y, 0.00011; C282Y/H63D, 0.00067; and H63D/H63D, 0.00101. CONCLUSIONS: Penetrance-adjusted estimates indicate that approximately 9 African Americans per 100,000 have a hemochromatosis phenotype and two common HFE mutations. Hemochromatosis-associated genotype frequencies varied 11.7-fold across regions.

Adult↗
PubMedDate not supplied

Molecular, histologic, and gross phenotype of skin wound healing in red Duroc pigs reveals an abnormal healing phenotype of hypercontracted, hyperpigmented scarring.

This study examined dermal wound healing in juvenile red Duroc pigs and determined that these animals exhibit a unique healing phenotype at multiple levels. Gross and histologic analysis revealed that full-thickness and deep dermal (1.8 mm deep) wounds both heal via formation of hypercontracted, hyperpigmented scars. Molecular analysis using reverse-transcriptase polymerase chain reaction and porcine-specific primer sets revealed that types I and III collagen, heat shock protein 47, bone morphogenetic protein-1, several proteoglycans, and tissue inhibitor of metalloproteinases 1-3 all showed a unique biphasic pattern of mRNA expression compared to previous results with Yorkshire pigs. This pattern was characterized by an initial peak of expression early after wounding, followed by a return to near-normal levels by days 28-42, and then a second increase in mRNA levels at days 56-70. The second phase of increased gene expression correlated with an increased collagen deposition as observed by picrosirius red staining and polarizing light microscopy. Reverse-transcriptase polymerase chain reaction analysis also revealed a prolonged expression of matrix metalloproteinase-2 compared to previous findings in the Yorkshire strain. Further characterization of the genetics and molecular biology associated with the red Duroc phenotype may provide insight into aberrant human wound healing.

Animals↗
PubMed1986

A family demonstrating inheritance of the Leach phenotype: a Gerbich-negative phenotype associated with elliptocytosis.

The proposita of a Canadian family and 2 of her sibs have the rare Leach phenotype and provide the first evidence that the Leach phenotype is an inherited condition. Their red cells are Ge: -2, -3 and fail to react, by the antiglobulin test, with the monoclonal antibodies GERO, BRIC 4 and BRIC 10. The minor sialoglycoproteins beta, beta 1 and gamma are apparently absent from their red cell membranes. A proportion of their red cells are elliptocytes indicating that beta and/or beta 1 and/or gamma have a function in maintaining normal red cell shape.

Antibodies, Monoclonal↗
PubMed1990

Investigation of Lewis phenotypes in Polynesians: evidence of a weak secretor phenotype.

The salivary ABH and Lewis antigens of Polynesians were measured using a standardised red cell agglutination microplate assay and compared with the red cell defined Lewis phenotypes. Salivary ABH substances were detected in almost all saliva samples tested, with low levels (partial secretion) of ABH substances in the saliva from Le(a+b-) and Le(a+b+) individuals. Salivary Leb substance was detected in all Le(a-b+) and Le(a+b+) samples and in almost all Le(a+b-) samples. It is evident from the results obtained that Polynesian red cell phenotypes cannot be used to predict the presence or absence of salivary substances. If the presence of a coding secretor gene is presumed responsible for salivary ABH antigens and salivary Leb antigen expression, then the incidence of a coding secretor gene in Polynesians is 98%. These results indicate that the recessive non-secretor gene is absent or rare in a Polynesian derived gene pool. Two variants of secretor individuals are found among Polynesians, secretors with expression of normal amounts of the product of the secretor gene, similar to Caucasians, and partial secretors with weak expression of the secretor gene products.

ABO Blood-Group System↗
PubMed1973

Genetics and physiology of a tolE mutant of Escherichia coli K-12 and phenotypic suppression of its phenotype by galactose.

The tolE mutation causes tolerance to colicins E2 and E3 as well as other effects on the phenotype of Escherichia coli K-12. The lipopolysaccharide of the mutant shows a reduction in the content of galactose, glucose, and rhamnose. The phenotype of the mutant, including the composition of the lipopolysaccharide, is suppressed by galactose. The map position is shown by the gene order trp-purB-tolE-tolD-galKETO.

Chloramphenicol↗
PubMed2004

Six1 and Eya1 expression can reprogram adult muscle from the slow-twitch phenotype into the fast-twitch phenotype.

Muscle fibers show great differences in their contractile and metabolic properties. This diversity enables skeletal muscles to fulfill and adapt to different tasks. In this report, we show that the Six/Eya pathway is implicated in the establishment and maintenance of the fast-twitch skeletal muscle phenotype. We demonstrate that the MEF3/Six DNA binding element present in the aldolase A pM promoter mediates the high level of activation of this promoter in fast-twitch glycolytic (but not in slow-twitch) muscle fibers. We also show that among the Six and Eya gene products expressed in mouse skeletal muscle, Six1 and Eya1 proteins accumulate preferentially in the nuclei of fast-twitch muscles. The forced expression of Six1 and Eya1 together in the slow-twitch soleus muscle induced a fiber-type transition characterized by the replacement of myosin heavy chain I and IIA isoforms by the faster IIB and/or IIX isoforms, the activation of fast-twitch fiber-specific genes, and a switch toward glycolytic metabolism. Collectively, these data identify Six1 and Eya1 as the first transcriptional complex that is able to reprogram adult slow-twitch oxidative fibers toward a fast-twitch glycolytic phenotype.

Animals↗
PubMed2003

Quantitative analysis of Escherichia coli metabolic phenotypes within the context of phenotypic phase planes.

In silico models of Escherichia coli metabolism have been developed to predict metabolic behavior and propose experimentally testable hypotheses. However, a thorough assessment of the metabolic phenotype requires well-designed experimentation and reproducible experimental techniques. A method for the quantitative analysis of E. coli metabolism in vivo within the framework of in silico phenotypic phase plane analysis is presented. Using this approach, we have quantitatively studied E. coli metabolism in various environmental conditions and nutritional media. Our experimental methodology, in combination with steady-state metabolic models, can be used to study biological properties and evaluate the metabolic capabilities of microbes.

Aerobiosis↗
PubMed1987

Study of familial alpha-1-proteinase inhibitor deficiency including a rare proteinase inhibitor phenotype (IZ). I. Alpha-1-phenotyping and clinical investigations.

Proteinase inhibitor (PI) phenotyping and clinical investigations were performed on 20 persons in three generations of a family with alpha 1-antitrypsin deficiency. Two persons were homozygotes and 9 were heterozygotes for the Z allele; one is the first reported IZ phenotype; 11 were common M-types. Both homozygotes and 5 of the heterozygotes, including the IZ individual, had suffered from recurring or chronic respiratory diseases. However, only mild to moderate impairment in lung function tests was observed in some of these patients (DLCO steady state, 3 subjects; FEV1, 3 subjects; FEF25-75, 2 subject; elevation of RV, 2 subjects). The rare IZ type, a 35-year-old female, smoker, showed normal lung function except for an elevated RV. Our results indicate that PI deficiency is not necessarily associated with severe lung destruction if noxious inhalants are absent.

Adolescent↗
PubMed1999

Genotype-phenotype analysis in X-linked Emery-Dreifuss muscular dystrophy and identification of a missense mutation associated with a milder phenotype.

Direct sequencing of the emerin gene in 22 families with Emery-Dreifuss muscular dystrophy (EMD) revealed mutations in 21 (95%), confirming that emerin mutations can be identified in the majority of families with X-linked EMD. Most emerin mutations result in absence of the protein. In this study three mutations (a missense mutation Pro183Thr and two in-frame deletions removing residues 95-99 and 236-241, respectively) were unusual in being associated with expression of mutant protein. The phenotype in these families was compared in detail with the clinical features in cases with typical null mutations. For the in-frame deletions there were no significant differences. In the family with the missense mutation the phenotype was milder. Age at onset was later for first symptoms and for development of ankle contractures and muscle weakness. These findings have diagnostic implications as well as pointing to functionally important regions of the emerin protein.

Amino Acid Substitution↗
PubMed2000

Co-receptor usage was more predictive than NSI/SI phenotype for HIV replication in macrophages: is NSI/SI phenotyping sufficient?

A monocyte-derived macrophage (MDM) culture assay was used to define the replication kinetics of HIV isolates. Ten-day-old MDMs were infected with HIV. Supernatants were collected and assayed for HIV p24 on days 3, 7, 10, and 14 post-infection (PI). In this assay, SF162 (macrophage tropic, NSI) produced increasing amounts of HIV p24 antigen with increasing time in culture. BRU (nonmacrophage tropic, SI) infection resulted in low levels of HIV p24 antigen with no increase in production during the culture period. A panel of 12 clinical isolates was evaluated. All isolates produced detectable levels of HIV p24 antigen in MDMs. However, the NSI viruses had significantly higher log10 HIV p24 antigen values at all times PI (P < 0.01). Co-receptor usage was determined for all 12 isolates (8 NSI and 4 SI). All SI isolates used CXCR4 for entry; two used CXCR4 only, one used CXCR4, CCR5, and CCR3, and one was a mixture of two isolates using CXCR4 and CCR5. None of the NSI viruses used CXCR4 for entry. All used CCR5 as their predominant co-receptor. Of the eight NSI isolates, three used CCR5 only, two used CCR5 and CCR2b, one used CCR5 and CCR3, and one used CCR5, CCR3, and CCR2b. Log10 HIV p24 antigen production on day 14 PI for viruses that used CCR5+CCR3 (3.79 + 1.40) was greater than for viruses that used CCR5+CCR2b (3.22 + 1.55) or CCR5 (3.32 + 1.49), and all were greater than those that used CXCR4 only (1.69 + 0.28), regardless of SI phenotype (P < 0.05). Thus, in these primary isolates, macrophage tropism and replication kinetics were closely linked to CCR5 utilization, whereas SI capacity was closely linked to CXCR4 utilization. Furthermore, viruses, which could use CCR5 and CCR3 for entry, had a replication advantage in macrophages, regardless of SI phenotype.

Amino Acid Sequence↗
PubMed2006

[Accurate description of the phenotype: the clinician's contribution to the clarification of genotype-phenotype correlations].

Utility of genomics in medical practice highly depends on the knowledge of genotype-phenotype correlations. So far, severity, natural course, drug-sensitivity, etc. belonging to a given mutation have been clarified in only a part of diseases. Concerning such research, the main difficulty is that the objectively determined genotype is often related to the more or less superficially or even subjectively described phenotype. Detailed, accurate, possibly objective recording of the clinical picture and the findings during follow-up by the clinician may make the protracted and heterogeneous collection of data much quicker and more reliable.

Genetics, Medical↗
PubMed1993

[Phenotyping: personal contribution to research on increased susceptibility of individual HLA phenotype combinations in predisposition to contact allergies].

We determined the A and B locus antigenic phenotype structure by means of the lymphocytotoxic test (Terasaki) in 43 subjects with allergic contact dermatitis verified by the Patch test, as well as in 103 healthy subjects (control group). Statistical fashioning was carried out by counting all of the phenotypes in the group examined by using the 2 x 2 table the X2 test with -correction according to Yates. In a case of an existing difference in frequency, the relative risk (RR) (Svejgaard) was determined. When RR was greater relation with the disease exists with the antigen which was found to have a greater EF value (Bengtsson). A statistically significant increase of A1 antigen frequency and decrease of A28 antigen frequency, as well as the absence of B13 and BW41 antigens in the group examined can be considered as a contribution in clarifying the genetic component in contact allergy etiopathogenesis.

Adolescent↗
PubMed1993

Epstein-Barr virus-latent gene expression and tumor cell phenotype in acquired immunodeficiency syndrome-related non-Hodgkin's lymphoma. Correlation of lymphoma phenotype with three distinct patterns of viral latency.

We investigated 49 acquired immunodeficiency syndrome-related lymphomas (ARLs) for Epstein-Barr virus (EBV) by Southern blotting and in situ hybridization and, in positive cases, used cryostat immunohistology to compare EBV-latent gene expression (EBV encoded small RNA-1 [EBER-1], EBV nuclear antigen-2 [EBNA-2], latent membrane protein-1 [LMP-1] and host cell immunophenotype (CD11a, CD18, CD54, CD58, CD21, CD23, CD30, CD39, CDw70, immunoglobulin) patterns with those reported in other EBV infections. EBV+ immunoblast-rich/large cell ARLs (n = 22) showed three patterns of latency: broad (EBER+EBNA-2+/LMP-1+; n = 9), reminiscent of a lymphoblastoid cell line phenotype; restricted (EBER+/EBNA-2-/LMP-1-; n = 6), similar to endemic Burkitt's lymphoma; and intermediate (EBER+/EBNA-2-/LMP-1+; n = 7), a pattern rarely described in vitro but seen in certain EBV-related malignancies. EBNA-2 expression was associated with extranodal lymphomas. EBV+ Burkitt-type ARLs (n = 11) usually showed the restricted latency pattern (n = 8), but some expressed the intermediate form (n = 3). Adhesion (CD54, CD58) and activation (CD30, CD39, CDw70) molecule expression varied with morphology (immunoblast-rich/large cell versus Burkitt-type), but was not independently correlated with EBV-positivity. CD30 and LMP-1 expression were associated. ARLs show heterogeneity regarding both the presence of EBV and latency pattern. Comparison of these phenotypically distinct lymphoma groups with known forms of EBV infection provides clues to their possible pathogenesis.

Adult↗
PubMed2004

Extreme variability of phenotype in patients with an identical missense mutation in the lamin A/C gene: from congenital onset with severe phenotype to milder classic Emery-Dreifuss variant.

BACKGROUND: Mutations of the LMNA gene, encoding the nuclear envelope proteins lamins A and C, have been associated with 7 distinct pathologic conditions. OBJECTIVE: To report 5 cases with the same missense mutation in exon 6 of the LMNA gene, resulting in an E358K substitution in the central rod domain. DESIGN: Case report. SETTING: Three muscle centers in England. PATIENTS: Five patients with missense mutations of the LMNA gene. RESULTS: All 5 individuals had muscle involvement, but the onset, severity, distribution of muscle weakness, and presence of associated features were highly variable. Three patients had humeroperoneal distribution of weakness and typical features of Emery-Dreifuss muscular dystrophy. Two other patients showed additional novel features. One had congenital onset and predominant axial weakness, with poor neck control and inability to sit independently at the age of 21 months. Another patient presented in childhood with an unusual pattern of muscle weakness, short stature, and midface hypoplasia with striking fat accumulation around the face and neck, in contrast to wasting of adipose tissue and muscle in the limbs. She developed both respiratory failure and cardiac arrhythmias in her late 20s. CONCLUSION: Our cases expand the clinical spectrum associated with mutations in the LMNA gene and further illustrate the overlapping phenotypes of the laminopathies.

Adult↗
PubMed1975

Studies on an unstable phenotype induced by UV irradiation: the lysine excreting (lex(-)) phenotype of the yeast Saccharomycosis lipolytica.

Unstable clones excreting L-lysine into their growth medium are obtained at a very high frequency following UV irradiation in both haploid and diploid strains of Saccharomycopsis lipolytica, provided they carry a mutation affecting the first enzyme of the lysine pathway and confering resistance to end product inhibition. The phenotype can be stabilized in some sublines; it appears as dominant and coupled with a decrease in spore viability. Excretion in batch cultures is confined to the end of the exponential phase, and seems not to consist in a simple release of the lysine pool content.

Amino Acids↗
PubMed2005

Phenotype dependent differential effects of interleukin-1beta and amyloid-beta on viability and cholinergic phenotype of T17 neuroblastoma cells.

Amyloid-beta accumulation in brains of Alzheimer's disease (AD) victims is accompanied by glial inflammatory reactions and preferential loss of cholinergic neurons. Therefore, the aim of this study was to find out whether proinflamatory cytokine interleukin 1beta (IL1beta) modifies effects of amyloid-beta (Abeta) on viability and cholinergic phenotype of septum derived T17 cholinergic neuroblastoma cells. In nondifferentiated T17 cells (NC) Abeta(25-35) (1 microg/ml) caused no changes in choline acetyltransferase (ChAT) activity, acetylcholine (ACh) release, subcellular distribution of acetyl-CoA, but doubled content of trypan blue positive cells. IL1beta (10 ng/ml) increased ACh release (125%) but did not change other parameters of NC. In the presence of Abeta IL1beta also increased ChAT activity (47%), ACh release (100%) but had no effect on acetyl-CoA distribution and cell viability. Differentiation with retinoic acid and dibutyryl cyclic AMP caused over two-fold increase of ChAT activity and ACh content, four-fold increase of ACh release and about 50% decrease of acetyl-CoA level in the mitochondria. In differentiated cells (DC), Abeta decreased ChAT activity (31%), ACh release (47%) and content of acetyl-CoA (80%) in cell cytoplasmic compartment, whereas IL1beta elevated ChAT activity (54%) and ACh release (32%). IL1beta totally reversed Abeta-evoked inhibition of ChAT activity and ACh release and restored control level of cytoplasmic acetyl-CoA but increased fraction of nonviable cells to 25%. Thus, IL1beta could compensate Abeta-evoked cholinergic deficits through the restoration of adequate expression of ChAT and provision of acetyl-CoA to cytoplasmic compartment in cholinergic neurons that survive under such pathologic conditions. These data indicate that IL1beta possess independent cholinotrophic and cholinotoxic activities that may modify Abeta effects on cholinergic neurons.

Acetyl Coenzyme A↗
PubMed2001

Unique phenotypic profile of monocytoid B cells: differences in comparison with the phenotypic profile observed in marginal zone B cells and so-called monocytoid B cell lymphoma.

Monocytoid B cells (MBCs) are a subset of B cells that may be recognized in several reactive and tumoral lymph node conditions, including toxoplasmic lymphadenitis, infectious mononucleosis, and Hodgkin's lymphoma. Although this is a commonly observed cell population, which has even given its name to a type of lymphoma, MBC lymphoma, scarcely any information is available about the function and characteristics of this cell type. A relationship with marginal zone (MZ) B lymphocytes has been claimed for MBCs, but this has not yet been fully proven. Indeed, specific markers for MBCs are still lacking, which has made it difficult to analyze their relationship with other B cell subpopulations and confirm the existence of tumors deriving from this B cell subset. We used a panel of cell cycle markers to explore the characteristics of MBCs and their relationship with MZ B cells, nodal MZ lymphoma, and splenic MZ lymphoma. We therefore compared the phenotypic profile of MBCs in different conditions with normal MZ B cells within the spleen and mesenteric lymph nodes, with a group of seven cases of nodal MZ/MBC lymphoma and another group of five cases of splenic MZ lymphoma. MBCs were mainly in the G(0) to G(1) phases, as deduced from the presence of a proportion of between 10 and 35% Ki67-positive cells, whereas very low expression was observed with cyclin A and cyclin B staining. Nests of MBCs were clearly labeled by the expression of p21(WAF1), a cyclin-dependent kinase inhibitor (CKI), rarely detectable in benign lymphocytes, and by cyclin E. Basically all MBCs were bcl-2-negative, and high cyclin D2 and cyclin D3 were also detected in these cells, at proportions and intensities above expected levels, when the percentage of proliferating cells was taken into account. p27(KIP1) expression was characterized by homogeneous reactivity, higher than that observed in other B cell populations with a relatively high-growth fraction. Immunoglobulin staining showed undetectable light and heavy chains. However, splenic MZ cells, nodal MZ lymphoma, and splenic MZ lymphoma showed a distinct expression of IgM and bcl-2, with high p27 (KIP1) nuclear expression and undetectable or low levels of cyclin A, B, E, or D, or p21(WAF1) expression. The data from this study show an unexpected immunophenotype in MBCs, different from the one observed in splenic and lymph node MZ B cells. This suggests that either MBCs are a unique B cell population from a distinct cell lineage, or if related to MZ cells, they would represent a definite differentiation stage characterized by a distinctive immunophenotype. They also show so-called MZ/MBC lymphoma to be more closely related to lymph node and splenic MZ B cells, as they do not share the most distinctive features of MBCs.

B-Lymphocytes↗
PubMed1999

D2 dopamine receptor gene (DRD2) allele and haplotype frequencies in alcohol dependent and control subjects: no association with phenotype or severity of phenotype.

Possible association between polymorphisms at the D2 dopamine receptor gene (DRD2) and alcohol dependence has been controversial since first proposed in 1990. The most studied polymorphisms to date are the TaqI "A" and "B" systems; they are unlikely to convey a physiological effect directly, and have not been demonstrated to be in linkage disequilibrium with any common polymorphism more likely to convey such an effect, in populations of European ancestry. A recently-described polymorphism in the promoter region of the DRD2 gene with possible effects on gene regulation is the first functional polymorphism described at this locus frequent enough in European-Americans (EAs) to have the potential to explain the positive findings. The goals of this study were to determine if we could replicate any previously reported associations particularly with the "A" and "B" systems and alcohol dependence or severity of alcohol dependence, using a screened control group design. We also studied the promoter system, "D" system, and 3 locus haplotypes. To test the hypothesis of an association rigorously, we studied four DRD2 polymorphic systems in 160 EA alcohol dependent subjects and 136 screened EA control subjects. To increase our potential to detect association with other polymorphisms at the locus, we also constructed 3 locus haplotypes including the DRD2 "A," "D," and promoter systems in both samples. There were no significant differences in allele frequencies between alcohol dependent and screened control subjects for any of the four systems studied. There were also no differences in 3-locus haplotype frequencies between these groups. Analysis based on severity of alcohol dependence also yielded no significant association. The screened control allele frequencies did not differ from allele frequencies we reported previously in unscreened controls. Thus, we replicated previous findings of no association between DRD2 alleles and alcohol dependence. These results can now be extended to include haplotypes containing the possibly-functional promoter system polymorphism. Explanations previously offered to explain lack of association (regarding alcohol dependence severity, and use of screened vs. unscreened controls) were not validated. These results are consistent with no effect of DRD2 polymorphisms on behavioral phenotypes related to alcohol dependence.

Alcoholism↗