Phenotypic discordance upon paternal or maternal transmission of duplications of the 11p15 imprinted regions

We report on two families in which the parental origin of duplications of the BWS imprinted regions on chromosome 11p15 influences the phenotype.In family A the transmission of a t(4; 11)(q35; p15.5) translocation results in duplication of BWSIC1 and BWSIC2. If this duplication is transmitted from the father, the extra chromosomal material has the paternal imprint. This results in overexpression of IGF2 and consequently an overgrowth phenotype. If the duplication is transmitted from the mother, the extra chromosomal material has the maternal imprint, resulting in overexpression of CDKN1C and a growth retardation phenotype.In family B an interstitial duplication of BWSIC1 results in an overgrowth phenotype when inherited from the father, similar to family A. However, no change in phenotype is observed if the duplication is transmitted through the mother suggesting that increased dosage of maternally expressed genes in the duplicated region has limited effect on the phenotype.     

Adenosine receptor activation promotes macrophage class switching from LPS-induced acute inflammatory M1 to anti-inflammatory M2 phenotype

Lipopolysaccharide induced monocytes/macrophages exhibit a pro-inflammatory M1 phenotype. Elevated levels of the purine nucleoside adenosine play a major role in this response. The role of adenosine receptor modulation in directing the macrophage phenotype switch from proinflammatory classically activated M1 phenotype to an anti-inflammatory alternatively activated M2 phenotype is investigated in this study. The mouse macrophage cell line RAW 264.7 was used as the experimental model and stimulated with Lipopolysaccharide (LPS) at a dose of 1 μg/ml. Adenosine receptors were activated by treating cells with the receptor agonist NECA (1 μM). Adenosine receptor stimulation in macrophages is found to suppress LPS-induced production of proinflammatory mediators (pro-inflammatory cytokines, Reactive Oxygen Species and nitrite levels). M1 marker CD38 (Cluster of Differentiation 38) and CD83 (Cluster of Differentiation 83) were significantly decreased while M2 markers Th2 cytokines, Arginase, TIMP (Tissue Inhibitor of Metalloproteinases) and CD206 (Cluster of Differentiation 206) exhibited an increase. Hence from our study we observed that activation of adenosine receptors can program the macrophages from a pro-inflammatory classically activated M1 phenotype to an anti-inflammatory alternatively activated M2 phenotype. We report the significance and a time course profile of phenotype switching by receptor activation. Adenosine receptor targeting may be explored as a therapeutic intervention strategy in addressing acute inflammation.     

Rh血型弱D和DEL表型的基因突变分析

目的研究Rh血型弱D和DEL表型的基因突变基础。方法用间接抗人球蛋白方法(IAT)和吸收放散的血清学方法鉴定弱D表型和DEL表型,然后用RHD基因特异的聚合酶链反应-序列特异性(PCR-SSP)和序列分析方法鉴定Rh血型弱D和DEL表型RHD基因的外显子中可能存在的变异。结果 Rh血型弱D表型个体的第6外显子有845G>A突变,Rh DEL表型个体的第9外显子有1227G>A突变。结论所应用的RHD基因测序方法可以用于弱D和DEL表型分子基础的研究,并为发现新的D变异表型和新的RHD等位基因奠定基础。     

Survey of the human acetylator polymorphism in spontaneous disorders.

There is ample evidence that the human acetylator phenotypes are associated with drug induced phenomena. It is principally the slow acetylators who exhibit toxic adverse effects because of their relative inability to detoxify the original drug compounds. In rare instances, however, it is the rapid acetylators who are at a disadvantage. In the matter of association of spontaneous disease with either acetylator phenotype, there are two groups of disorders to consider. First, disorders in which carcinogenic amines are known to be an aetiological factor. This is because these amines are substrates for the polymorphic N-acetyltransferase activity and hence there is a possible rational basis for searching for an association. Secondly, other disorders where searches for associations are based more on hunches. In the first group there is a definite statistical association between cancer of the bladder and the slow acetylator phenotype. In prevalence studies the slow phenotype is 39% more associated with bladder cancer than is the rapid phenotype. On the basis of the evidence now available it is not possible to say whether this association is because slow acetylators develop the disease more frequently or whether they survive longer. In the second group the relevant studies show (1) a greatly increased prevalence of slow acetylators in Gilbert's disease; (2) a confirmed association between the rapid acetylator phenotype and diabetes; (3) a possible association between the rapid acetylator phenotype and breast cancer; (4) a possible association between the slow acetylator phenotype and leprosy in Chinese patients; (5) an earlier age of onset of thyrotoxicosis (Graves' disease) in slow acetylators than in rapid acetylators; (6) no evidence of an association between either phenotype and spontaneous systemic lupus erythematosus.     

Mutator natural Escherichia coli isolates have an unusual virulence phenotype

A small percentage of natural Escherichia coli isolates (both commensal and pathogenic) have a mutator phenotype related to defects in methyl-directed mismatch repair (MR) genes. We investigated whether there was a direct link between the mutator phenotype and virulence by (i) studying the relationships between mutation rate and virulence in a mouse model of extraintestinal virulence for 88 commensal and extraintestinal pathogenic E. coli isolates and (ii) comparing the virulence in mice of MR-deficient and MR-proficient strains that were otherwise isogenic. The results provide no support for the hypothesis that the mutator phenotype has a direct role in virulence or is associated with increased virulence. Most of the natural mutator strains studied displayed an unusual virulence phenotype with (i) a lack of correspondence between the number of virulence determinants and pathogenicity in mice and (ii) an intermediate level of virulence. On a large evolutionary scale, the mutator phenotype may help parasites to achieve an intermediate rate of virulence which mathematical models predict to be selected for during long-term parasite-host interactions.     

Balanced reciprocal translocation mosaicism associated with an abnormal phenotype

Balanced reciprocal translocation mosaicism is rarely reported in humans. Only two previous cases have been associated with an abnormal phenotype. We report on a third case of apparently balanced reciprocal translocation mosaicism associated with an abnormal phenotype, largely different from those reported previously. Since low levels of mosaicism may not be detected in routine cytogenetic analyses, balanced reciprocal translocation mosaicism may be associated with an abnormal phenotype more often than has been recognized to date. © 1993 Wiley-Liss, Inc.     

Phenotype of cultured fetal perivascular cells from human placenta studied by scanning electron microscopy

The phenotype of perivascular placental cells has previously been studied using tissue sections from the fetal villi. The examination of these cells in culture by scanning electron microscopy gives us the opportunity to observe their three-dimensional phenotypes and associations outside their normal constraints. Human umbilical endothelial cells, which have a phenotype comparable to that observed in other sutdies, seem more flattened in culture than in their usual environment. Microvascular endothelial cells did not attain an epithelioid phenotype with close contacts between cells but formed a network of branched, elongated cells with phagocytotic activity. Some circular associations were observed when using a gelatinized matrix. Microvascular pericytes were large, flattened cells with an irregular border that pushed up nodular associations on a gelatin matrix. Chorioplacental myocytes adopted a network template comparable to that developed by microvascular endothelial cells. However, these elongated cells were thicker, without microvilli, and superficial filaments could be observed. In culture, confluent endothelial cells from the umbilical cord or microvascular pericytes associated as nodules reached a cell phenotype close to their in vivo counterparts. This attainment of an in vivo phenotype remains questionable for chorioplacental myocytes. Microvascular endothelial cells, however, though there was sparse formation of circular associations, remained far from their in vivo phenotype.     

Familial atypical multiple mole-melanoma syndrome.

A family is described showing concordance for malignant melanoma and a cutaneous phenotype characterised by multiple large moles of variable size and colour (reddish-brown to bright red) with pigmentary leakage. Transmission of the cutaneous phenotype in the subject family, and in several others currently under investigation, shows an inheritance pattern consistent with a simple autosomal dominant factor. This cutaneous phenotype signifying melanoma risk may now be added to an increasing body of knowledge dealing with cancer-related genodermatoses.     

Testing for induction of clindamycin resistance in erythromycin-resistant isolates of Staphylococcus aureus

Disk diffusion and broth microdilution (BMD) were used to perform clindamycin (CLI) induction testing on 128 selected nonduplicate isolates of Staphylococcus aureus. Disk diffusion testing involved placing CLI and erythromycin (ERY) disks approximately 12 mm apart (measured edge to edge) on a Mueller-Hinton agar plate that had been inoculated with an S. aureus isolate; the plate was then incubated for 16 to 18 h. Two distinct induction phenotypes (labeled D and D(+)) and four noninduction phenotypes (designated as negative [Neg], hazy D zone [HD], resistant [R], and susceptible [S]) were observed in disk diffusion results. A clear, D-shaped zone of inhibition around the CLI disk was designated as the D phenotype and was observed for 21 isolates while a D-shaped zone containing inner colonies growing up to the CLI disk was designated as D(+) (17 isolates). In addition, 10 isolates were CLI susceptible and ERY resistant but were not inducible and showed no blunting of the CLI zone (Neg phenotype). Isolates that were CLI and ERY resistant (constitutive macrolide-lincosamide-streptogramin B resistance) demonstrated either a double zone of inhibition with an inner ring of reduced growth up to the edge of the disks (HD phenotype; 33 isolates) or solid growth around the CLI and ERY disks (R phenotype; 16 isolates). Finally, 31 isolates were susceptible by disk testing to both CLI and ERY (S phenotype). PCR results showed that isolates with a D phenotype harbored ermA, isolates with a D(+) phenotype contained either ermC (16 isolates) or ermA and ermC (one isolate), and all 10 isolates with a Neg phenotype contained msrA. All isolates with an HD or R phenotype harbored at least one erm gene. Isolates showing the D(+) phenotype by disk diffusion were also detected by BMD using a variety of CLI and ERY concentrations; however, isolates with the D phenotype were more difficult to detect by BMD and will likely require optimization of ERY and CLI concentrations in multilaboratory studies to ensure adequate sensitivity. Thus, at present, disk diffusion is the preferred method for testing S. aureus isolates for inducible CLI resistance.     

Phenotype of cultured fetal perivascular cells from human placenta studied by scanning electron microscopy

 The phenotype of perivascular placental cells has previously been studied using tissue sections from the fetal villi. The examination of these cells in culture by scanning electron microscopy gives us the opportunity to observe their three-dimensional phenotypes and associations outside their normal constraints. Human umbilical endothelial cells, which have a phenotype comparable to that observed in other sutdies, seem more flattened in culture than in their usual environment. Microvascular endothelial cells did not attain an epithelioid phenotype with close contacts between cells but formed a network of branched, elongated cells with phagocytotic activity. Some circular associations were observed when using a gelatinized matrix. Microvascular pericytes were large, flattened cells with an irregular border that pushed up nodular associations on a gelatin matrix. Chorioplacental myocytes adopted a network template comparable to that developed by microvascular endothelial cells. However, these elongated cells were thicker, without microvilli, and superficial filaments could be observed. In culture, confluent endothelial cells from the umbilical cord or microvascular pericytes associated as nodules reached a cell phenotype close to their in vivo counterparts. This attainment of an in vivo phenotype remains questionable for chorioplacental myocytes. Microvascular endothelial cells, however, though there was sparse formation of circular associations, remained far from their in vivo phenotype. Accepted: 24 June 1996     

Characterization of Saccharomyces cerevisiae natural populations for pseudohyphal growth and colony morphology

In this work we have analyzed the colony and cellular morphologies of natural populations of Saccharomyces cerevisiae strains in response to different environmental stimuli. Among one thousand strains grown on YPD medium, 2.5% exhibited a rough (R) colony phenotype versus a smooth (S) phenotype. When grown on the ammonium-deficient medium SLAD, 56% of the strains showed a filamentous phenotype, often associated (43.8%) with an invasive phenotype, while 4.7% of the strains exhibited only an invasive phenotype. The rough phenotype on YPD was always associated with the filamentous phenotype on SLAD. A subset of 52 strains was further characterized for the growth phenotype under different stimuli (nitrogen deprivation, addition of alcohols, growth on proline as sole nitrogen source). On 27 strains, genetic analysis of the spore products was also performed. The entire set of data showed a wide distribution of dimorphism in the yeast population and great variability with respect to the dimorphic switch capability. Some strains grew with peculiar colony morphologies under different environmental stimuli and some showed colony morphology variations. Ecological implications of the wide spreading of dimorphic behavior and the occurrence of peculiar colony morphologies in natural yeasts are discussed.     

Characterization of beta-lactam-resistant Klebsiella oxytoca isolated in a neonatal intensive care unit

The occurrence of Klebsiella oxytoca resistant to ampicillin, piperacillin, aztreonam and cefuroxime in a neonatal intensive care unit, including two cases of septicemia, was shown to consist of a spread on three consecutive occasions caused by three different biochemical Klebsiella oxytoca phenotypes. All isolates, except six surface isolates from one infant belonging to phenotype 1, were sensitive to cefotaxime (MIC 0.5-4 mg/l) and ceftazidime (MIC 0.25-1 mg/l). Isolates of phenotypes 1 and 2 produced a beta-lactamase with an isoelectric point of 5.5 and isolates of phenotype 3, a beta-lactamase with an isoelectric point of 7.9. The beta-lactamases of all three phenotypes hydrolysed benzylpenicillin and more slowly cephalothin. All phenotype 1 isolates carried a 2.9 Md plasmid and most isolates also a 36 Md plasmid. All phenotype 2 isolates carried a 4.8 Md plasmid and one isolate also a 30 Md plasmid. The phenotype 3 isolates carried only one 85 Md plasmid.     

microMRI-HREM pipeline for high-throughput, high-resolution phenotyping of murine embryos

Rapid and precise phenotyping analysis of large numbers of wild-type and mutant mouse embryos is essential for characterizing the genetic and epigenetic factors regulating embryogenesis. We present a novel methodology that permits precise high-throughput screening of the phenotype of embryos with both targeted and randomly generated mutations. To demonstrate the potential of this methodology we show embryo phenotyping results produced in a large-scale ENU-mutagenesis study. In essence this represents an analysis pipeline, which starts with simultaneous micro-magentic resonance imaging (microMRI) screening (voxel size: 25.4 x 25.4 x 24.4 microm) of 32 embryos in one run. Embryos with an indistinct phenotype are then cut into parts and suspect organs and structures are analysed with HREM (high-resolution episcopic microscopy). HREM is an imaging technique that employs 'positive' eosin staining and episcopic imaging for generating three-dimensional (3D) high-resolution (voxel size: 1.07 x 1.07 x 2 microm) digital data of near histological contrast and quality. The results show that our method guarantees the rapid availability of comprehensive phenotype information for high numbers of embryos in, if necessary, histological quality and detail. The combination of high-throughput microMRI with HREM provides an alternative screening pipeline with advantages over existing 3D phenotype screening methods as well as traditional histology. Thus, the microMRI-HREM phenotype analysis pipeline recommends itself as a routine tool for analysing the phenotype of transgenic and mutant embryos.     

Expression and prognostic significance of epithelial-mesenchymal transition-related markers and phenotype in serous ovarian cancer

The epithelial-mesenchymal transition (EMT) is known to be associated with carcinoma invasion and metastasis. Previous studies have demonstrated that the expression of EMT-related proteins in carcinoma cells in many organs is associated with a higher histologic grade and a poor prognosis. However, the clinical significance of EMT in ovarian cancers is controversial.Formalin-fixed and paraffin-embedded tumor samples of 198 high-grade serous carcinomas (HGSCs) and 13 serous borderline tumors or low-grade serous carcinomas (SBT/LGSCs) of the ovary were analyzed. EMT phenotype marker expression, including claudin 4, E-cadherin, N-cadherin, α-smooth muscle actin (α-SMA) and vimentin, and EMT related transition factor expression, including paired-related homeobox 1 (PRRX1), SLUG, SNAI1, and TWIST1, were evaluated by immunohistochemistry. EMT phenotype was classified into three groups including complete EMT phenotype, incomplete EMT phenotype, and epithelial phenotype according to epithelial and mesenchymal marker expression.EMT phenotypes varied in HGSC (Complete phenotype, 32.3%; Incomplete phenotype, 42.9%; epithelial phenotype, 24.7%) compared with SBT/LGSC. EMT phenotype and each EMT phenotype markers were not significantly associated with patient survival of HGSCs in multivariate analysis. However transition factor, SLUG expression, correlated with advanced disease and SLUG expression was an independent predictor of poor overall survival in HGSC.EMT related transition factor expression like SLUG is more important in association with clinical outcome than EMT phenotype itself in HGSC.     

Fragile X mutation and FG syndrome-like phenotype

We present data on 4 mentally retarded brothers, 2 of whom were dizygotic twins with congenital hypotonia, constipation, head size disproportionately large for length or height, and a combination of minor anomalies suggestive of FG syndrome. These brothers have a mentally retarded full sister with similar minor anomalies and an older half-brother with the Martin-Bell syndrome. The mother is mentally retarded; 4 of 7 individuals are positive for fragile X, but all have a CGG expansion ranging from 0.2–2 to 4 kb. Although the phenotype is not completely typical of the FG syndrome and the coincidence of the FMR1 mutation and segregation of the MCA/MR phenotype are highly unlikely, the FMR1 mutation may affect morphogenesis more extensively and differently than the Martin-Bell syndrome does to effect an FG syndromelike phenotype in certain families. This phenotype does not appear to be a contiguous gene syndrome, but an effect of the FMR1 mutation on an adjacent gene must be considered. © 1996 Wiley-Liss, Inc.     

Revision joint replacement, wear particles, and macrophage polarization

Currently, younger, more active patients are being offered total joint replacement (TJR) for end-stage arthritic disorders. Despite improved durability of TJRs, particle-associated wear of the bearing surfaces continues to be associated with particulate debris, which can activate monocyte/macrophages. Activated macrophages then produce pro-inflammatory factors and cytokines that induce an inflammatory reaction that activates osteoclasts leading to bone breakdown and aseptic loosening. We hypothesized that activated macrophages in tissues harvested from revised joint replacements predominantly express an M1 pro-inflammatory phenotype due to wear-particle-associated cell activation, rather than an M2 anti-inflammatory phenotype. We further questioned whether it is possible to convert uncommitted monocyte/macrophages to an M2 phenotype by the addition of interleukin-4 (IL-4), or whether it is necessary to first pass through an M1 intermediate stage. Retrieved periprosthetic tissues demonstrated increased M1/M2 macrophage ratios compared to non-operated osteoarthritic synovial tissues, using immunohistochemical staining and Western blotting. Uncommitted monocyte/macrophages with/without polymethyl-methacrylate particles were transformed to an M2 phenotype by IL-4 more efficiently when the cells were first passed through an M1 phenotype by exposure to endotoxin. Wear particles induce a pro-inflammatory microenvironment that facilitates osteolysis; these events may potentially be modulated favorably by exposure to IL-4.     

Phenotypes and genotypes in cystinuria

Quantitative data are presented on the cystine, lysine and arginine excretion in patients with cystine stone formation and in their relatives in twenty-five families.
It is suggested that two distinct abnormal phenotypes can be differentiated. Phenotype 1 is characterized by a greatly increased excretion of cystine, lysine, arginine and ornithine. Because of the high cystine concentration in the urine cystine stone formation is fairly frequent. Phenotype 2 is characterized by a moderately increased cystine and lysine excretion, whilst the arginine and ornithine excretion is normal or only slightly raised. In this phenotype stone formation occurs only very rarely.
The families fall into two groups with regard to the occurrence of phenotype 2. In one group of families phenotype 2 is not found. In these families the segregation of phenotype 1 is consistent with the hypothesis that it represents the homozygote for a rare recessive gene. This type has been called 'recessive cystinuria'. In the other group of families phenotype 2 is frequently found. Most of the propositi are of phenotype 1. The distribution of the two abnormal phenotypes in such families is consistent with the hypothesis that phenotype 1 represents the homozygote, and phenotype 2 the heterozygote, of a rare abnormal gene. Two families have propositi of phenotype 2 who, in this instance, happen to have formed stones. These families contain no individuals of phenotype 1. Phenotype 2 again segregates in a manner which suggests that it represents the heterozygote of an abnormal gene. In all families in which phenotype 2 is found the condition has been called 'incompletely recessive cystinuria'.     

In vitro susceptibility of different erythromycin-resistant phenotypes of Streptococcus pyogenes to moxifloxacin and other fluoroquinolones

The aim of the present study was to evaluate the in vitro activity of moxifloxacin (BAY 12-8039) compared with ciprofloxacin, ofloxacin and sparfloxacin against 156 Group A beta-haemolytic Streptococcus (GABHS) strains. Sixty strains were macrolide- lincosamide- and streptogramin B susceptible; 16 strains exhibited a constitutive resistance phenotype; 32 strains exhibited an inducible phenotype; and 48 strains were characterized by the M-type efflux-dependent phenotype. The MICs were determined by an agar dilution method according to NCCLS-approved guidelines. Moxifloxacin showed an enhanced activity compared with the other fluoroquinolones against all the different macrolide-resistant phenotypes.     

Role of lipooligosaccharide in virulence of the Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius for infant rats.

Clonally related strains of Haemophilus influenzae biogroup aegyptius have recently been associated with Brazilian purpuric fever (BPF), a fulminant, systemic disease in children. Using an infant rat bacteremia model for BPF, we found that a rat blood-passaged BPF isolate of H. influenzae biogroup aegyptius was more virulent than the original strain was. When compared with the original strain, the animal-passaged variant was found to display an altered lipooligosaccharide (LOS) phenotype and to lack pili. To examine the role of LOS phenotype and pili in virulence, we isolated isogenic variants differing in LOS phenotype or expression of pili. The virulence of variants was compared by examining the results of blood cultures obtained 24 h after intraperitoneal inoculation with 10(5) CFU. Our results indicate that the LOS phenotype is a critical determinant of BPF clone virulence for infant rats. To a lesser extent, the absence of piliation and an undefined additional factor(s) contribute to virulence.     

Gonococcal sensitivity to fecal lipids can be mediated by an Mtr-independent mechanism.

Various factors affect the sensitivity of Neisseria gonorrhoeae to physiological levels of hydrophobic molecules. A total of 98 N. gonorrhoeae strains from rectal, cervical, and urethral cultures of homosexual men and heterosexual men and women were examined for their sensitivities to fecal lipids. Isolates were characterized according to cell envelope phenotype, auxotype, and protein I serogroup. Although cell envelope phenotype was an important factor in the resistance of this organism to fecal lipids (Mtr phenotype greater than wild type greater than Env phenotype), other factors were also of importance. AHU- strains (strains having a requirement for arginine, hypoxanthine, and uracil) uniformly exhibited a wild-type envelope phenotype but were as sensitive to fecal lipids as were Env strains. The protein I serogroup was not a factor in determining the sensitivity of wild-type envelope phenotype non-AHU- strains to fecal lipids. However, sexual preference and site of isolation were important factors. Wild-type envelope phenotype (non-AHU-) strains from homosexual men and heterosexual women were more resistant to fecal lipids than were similar isolates from heterosexual men. When these strains were compared by isolation site, it was observed that rectal isolates from homosexual men and heterosexual women were more resistant than were cervical isolates from heterosexual women or urethral isolates from heterosexual men. Urethral isolates from homosexual men were also more resistant to fecal lipids than were urethral isolates from heterosexual men. These data suggest that the host environment can select for increased resistance to hydrophobic molecules by an Mtr-independent mechanism. The basis for this Mtr-independent resistance is presently unknown, but it is likely that it involves an alteration of the target site(s) for fecal lipid inhibition.