The MTT assays of bovine retinal pericytes and human microvascular endothelial cells on DLC and Si-DLC-coated TCPS.

MTT (Tetrazolium)-assay suggests that diamond-like carbon (DLC) and silicon-doped DLC (Si-DLC) films obtained under appropriate deposition parameters are not toxic to bovine retinal pericytes, and human microvascular endothelial cells (HMEC). The observed frequency distributions of the optical density (OD) values indicative of cell viability are near Gaussian-normal distribution. One-way ANOVA indicates that at 0.05 levels the population means are not significantly different for the coated and control samples. The observed OD values depend on the cell line (cell growth/metabolic rate), possibly cell cycle stage, the deposition parameters-bias voltage, ion energy, pressure, argon precleaning, and the dopant. For colored thin films like DLC with room temperature photoconductivity and photoelectric effects, it is important to account for the OD contribution from the coating itself. MTT assay, not surprisingly, seems not to be highly sensitive to interfacial cellular interaction resulting from the change in the film's nanostructure, because the tetrazolium metabolism is mainly intracellular and not interfacial. The thin films were synthesized by 13.56 MHz RF-PECVD using argon and acetylene as source gases, with tetramethylsilane (TMS) vapor introduced for silicon doping. This study could be relevant to biomedical application of the films in the eye, peri-vascular, vascular compartments, and for cell-tissue engineering.

Follow up of fetal outcome in cases of maternal phenylketonuria in Northern Ireland.

BACKGROUND: Maternal phenylketonuria (PKU) can result in multiple congenital anomalies. In Northern Ireland, the prevalence of PKU is relatively high at 1 in 4000. OBJECTIVE: To assess the outcome of 39 pregnancies in 20 mothers. RESULTS: Dietary control was established before conception in 17 pregnancies (44%). Five mothers with hyperphenylalaninaemia had 11 pregnancies. There were no congenital anomalies in this group, and all appear to be developing normally. Fifteen women with classical PKU had 28 pregnancies. One pregnancy ended in a first trimester miscarriage. Twelve out of 27 (44%) completed pregnancies produced babies with a congenital anomaly and/or developmental delay. CONCLUSIONS: Most problems occurred when dietary control was not established until after the 2nd trimester. As the cohort of young women with treated PKU is growing steadily, maternal PKU is going to become an even greater cause for concern.

Segregation distortion in myotonic dystrophy.

Myotonic dystrophy (DM) is an autosomal dominant disease which, in the typical pedigree, shows a three generation anticipation cascade. This results in infertility and congenital myotonic dystrophy (CDM) with the disappearance of DM in that pedigree. The concept of segregation distortion, where there is preferential transmission of the larger allele at the DM locus, has been put forward to explain partially the maintenance of DM in the population. In a survey of DM in Northern Ireland, 59 pedigrees were ascertained. Sibships where the status of all the members had been identified were examined to determine the transmission of the DM expansion from affected parents to their offspring. Where the transmitting parent was male, 58.3% of the offspring were affected, and in the case of a female transmitting parent, 68.7% were affected. Studies on meiotic drive in DM have shown increased transmission of the larger allele at the DM locus in non-DM heterozygotes for CTGn. This study provides further evidence that the DM expansion tends to be transmitted preferentially.

De novo direct duplication 2 (p12-->p21) with paternally inherited pericentric inversion 2p11.2 2q12.2.

We report a 4-year-old girl with a previously undescribed de novo duplication of 2p12->2p21 on the same homologue as a paternally inherited pericentric inversion of region 2p11.2-->2q12.2, resulting in dysmorphic features, cardiac abnormality, cleft palate, respiratory problems, severe growth retardation and developmental delay. This case raises an important question--did the paternal pericentric inversion influence the occurrence of the de novo duplication?

Ullrich-Turner syndrome: seven pregnancies in an apparent 45,X woman.

A 37-year-old woman was referred for genetic counseling after termination of her probable seventh pregnancy. Ultrasound examination at 13 weeks of gestation had shown a fetus with bilateral cystic hygromas. A transabdominal amniocentesis confirmed 45,X karyotype in the fetus. The patient had marked short stature and a 45,X chromosome constitution in blood lymphocytes. Subsequently she had a hysterectomy and oophorectomy. Tissue of representative sites of the pathological specimen showed a 45,X chromosome constitution. However, molecular analysis of 8 sites from the uterus and ovaries, and of skin fibroblasts with X-chromosome microsatellites showed the presence of only one allele, except for the microsatellite DXS996 which demonstrated 2 alleles (155 bp and 161 bp) in ovarian tissue. The lymphocytes from the mother and her only son demonstrated the same single allele (161 bp). We conclude that molecular analysis of lymphocytes and of tissue is necessary for detecting low-level mosaicism in apparently homogeneous 45,X women.

Cross-reactivity of antibodies raised to Pseudomonas fluorescens protease with extracellular proteins produced by meat-spoiling pseudomonads.

The cross-reactivity patterns of antibodies to Pseudomonas fluorescens protease with the extracellular proteins produced by a number of meat-spoiling pseudomonads were studied. Immunoblotting studies showed that purified IgG to Ps. fluorescens protease cross-reacted with extracellular proteins in the cell culture supernatant fluids of Pseudomonas spp., including Ps. fragi and Ps. lundensis. In the case of Ps. lundensis and Pseudomonas spp. 11390, the cross-reactive moieties were of similar molecular weight to the Ps. fluorescens protease (46 kDa). However, in Ps. fragi the cross-reactive moiety was a lower molecular weight protein (8 kDa). This may represent a fragment of the active enzyme. These results indicate the presence of common antigenic determinants among the proteases of meat spoiling pseudomonads.

A new method for the detection of proteolytic activity in Pseudomonas lundensis after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

A new method for the visualization of proteolytic activity in cell culture supernatant from Pseudomonas lundensis after sodium dodecyl sulfate (SDS)--gel electrophoresis is described. Following conventional electrophoresis, the gel is washed in a methanol-containing buffer to facilitate partial removal of SDS. After incubation with 0.5% casein the gel is stained for protein with Coomassie Brilliant Blue R-250. Bands with proteolytic activity appear as clear areas in the gel against a blue-stained background. Molecular weight standards electrophoresed in the same gel stain more intensely than the background and allow determination of the molecular weights of the proteolytic components. The sensitivity of post-electrophoretic reactivation in SDS-gels was determined using trypsin as standard. A slight modification of the technique allowed detection of proteolytic activity in nondenaturing and in isoelectric focusing gels.

Congenital heart disease and urinary tract abnormalities in two siblings with DOOR syndrome.

The acronym DOOR was first used by Cantwell in 1975 to describe a syndrome comprising sensorineural deafness, osteodystrophy, onychodystrophy, and mental retardation. To date, 16 cases of the syndrome have been documented in the literature. We present two sisters who died in early infancy with the clinical features of DOOR syndrome, both of whom in addition had cardiac defects and urinary tract abnormalities. Both infants had the classical clinical features of sensorineural deafness, seizures, hypoplastic nails, finger-like thumbs, and the characteristic facies of the syndrome. Autopsy in each case revealed the additional findings of a membranous ventricular septal defect and a septum secundum atrial septal defect. The first child had left-sided hydronephrosis and hydroureter, and the second sibling had bilateral hydronephrosis, hydroureter, and dilatation of the bladder. Congenital heart disease and renal abnormalities have not to our knowledge been previously described in association with the DOOR syndrome.