Is the hepatitis C seroconversion rate higher with dialysis catheters than A-V fistula.
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Adult↗
Biomedical subjects
B Popovich
Publications and source records attributed to B Popovich.
Monozygotic twins discordant for the Russell-Silver syndrome.
Russell-Silver syndrome (RSS) is a pattern of malformation characterized by intrauterine and postnatal growth retardation, limb asymmetry, triangular face, and hypospadias. We report on a patient, from a triplet pregnancy, who was one of identical male twins discordant for RSS. R.B. was a 710-g male born at 33 weeks of gestation, with hypospadias, chordee, and undescended testes. He had a normal 46,XY karyotype and no renal abnormalities. Female triplet A weighed 1,843 g, and male triplet B weighed 1,920 g. Both had normal physical findings and neonatal period. R.B. was first seen by us at age 6 7/12 years with short stature, triangular and asymmetric face, lower limb length discrepancy, and surgically repaired genital anomalies. Growth hormone testing results were normal. At age 8 7/12 years the brothers appeared physically identical except for size, with a height differential of 114.25 vs. 121.5 cm. Testing to establish biological zygosity was performed using VNTR (variable number tandem repeat) DNA probes YNH24 (D2S44), CMM101 (D14S13), EFD52 (D17S26), TBQ7 (D10S28), and 3'HVR (D16S85), PCR loci MCT118 (D1S80), and HLA-DQ alpha. These data indicate a > 99.99% probability of triplets B and C being monozygotic twins. While most occurrences of RSS are sporadic, familial cases suggesting autosomal dominance have been reported. Three other cases of probable monozygotic twins with RSS have been described. The significance of this confirmation of discordance in determining the cause of RSS is discussed.
Abnormalities, Multiple↗
Fluorescent multiplex linkage analysis and carrier detection for Duchenne/Becker muscular dystrophy.
We have developed a fast and accurate PCR-based linkage and carrier detection protocol for families of Duchenne muscular dystrophy (DMD)/Becker muscular dystrophy (BMD) patients with or without detectable deletions of the dystrophin gene, using fluorescent PCR products analyzed on an automated sequencer. When a deletion is found in the affected male DMD/BMD patient by standard multiplex PCR, fluorescently labeled primers specific for the deleted and nondeleted exon(s) are used to amplify the DNA of at-risk female relatives by using multiplex PCR at low cycle number (20 cycles). The products are then quantitatively analyzed on an automatic sequencer to determine whether they are heterozygous for the deletion and thus are carriers. As a confirmation of the deletion data, and in cases in which a deletion is not found in the proband, fluorescent multiplex PCR linkage is done by using four previously described polymorphic dinucleotide sequences. The four (CA)n repeats are located throughout the dystrophin gene, making the analysis highly informative and accurate. We present the successful application of this protocol in families who proved refractory to more traditional analyses.
DNA↗
Reliability and validity of the Popovich Scale in home health care assessments.
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Aged↗
Thyroid hormone induced changes in cardiac proteins and mRNAs.
Contraction of the hypothyroid heart is characterized by delayed diastolic relaxation and decreased velocity of systolic contraction. In order to determine if these alterations could be mediated by the changes in the mRNA coding for the Ca++ ATPase of the sarcoplasmic reticulum and alterations of the mRNAs coding for myosin heavy chain (MHC) alpha and beta, the levels of these specific mRNAs were quantitated using a Northern blotting technique. We find that the Ca++ ATPase mRNA was 3-fold lower in hypothyroid hearts. After T3 administration to hypothyroid rats, Ca++ ATPase mRNA increased to 66% of control levels within 2 hrs and to 100% of control levels 5 hrs after T3 administration. In the hypothyroid heart, MHC beta mRNA was the predominant message with MHC alpha mRNA barely detectable. Administration of 2 mg of T3 led to a significant increase in MHC alpha mRNA levels first detectable 2 hrs after T3 administration. Twenty-four hrs after T3 administration, MHC alpha mRNA levels had normalized. The results of these studies indicate that thyroid hormone mediates significant alterations in the level of the mRNA coding for the Ca++ ATPase of the sarcoplasmic reticulum and of the mRNAs coding for MHC alpha and beta. Changes in the level of these specific mRNAs resulting in lower levels of the corresponding proteins may explain the delayed diastolic relaxation and the decreased velocity of contraction of the hypothyroid heart.
Animals↗
Chromosomal breakage in normal and fragile X subjects using low folate culture conditions.
To investigate whether the fragile X syndrome is associated with a generalised chromosomal instability, we compared the frequency and distribution of chromosomal breakage in lymphocytes grown in low folate medium from normal subjects and from patients with the syndrome. Although low folate conditions increased the rate of chromosome breakage, no difference in frequency or distribution of chromosomal breakage was found between the two groups. This suggests that the fragile X syndrome is not associated with a generalised chromosome instability expressed in folate deficient medium and assessed in terms of chromosomal breakage.
Chromosome Aberrations↗
Methylation analysis of the fragile X syndrome by PCR.
The fragile X syndrome is predominantly caused by a large expansion of a CGG trinucleotide repeat in the promoter region of the FMR1 gene, which is associated with methylation and downregulation of transcription. The molecular diagnosis of this disorder is based on repeat size and methylation analysis of the FMR1 gene usually by Southern blot analysis. We describe a PCR-based method for the analysis of methylation of the FMR1 gene, which involves bisulfite treatment of DNA prior to amplification. Fifty-two normal and 48 affected, premutation, or mosaic males were analyzed in a blinded study by this method. A prospective study of 30 males suspected of fragile X was also performed. Amplification specific for the methylated FMR1 sequence was readily observed in all individuals with a full mutation, whereas all normal and premutation individuals showed only amplification-specific for the unmethylated sequence, thus, allowing affected and unaffected males to be distinguished. A full mutation in the presence of mosaicism was also detectable by this method. Methylation-specific PCR appears to be a rapid and reliable tool for the diagnosis of fragile X males.
Base Sequence↗
Functional assessments in home care.
The Popovich Scale holds great promise for use in home healthcare. Having established reliability and validity makes the tool valuable in promoting high quality nursing care at home. It is applicable to all older adults and their caregivers regardless of medical problems, nursing diagnoses, and regulatory agencies.
Aged↗
Technical standards and guidelines for fragile X: the first of a series of disease-specific supplements to the Standards and Guidelines for Clinical Genetics Laboratories of the American College of Medical Genetics. Quality Assurance Subcommittee of the Laboratory Practice Committee.
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Blotting, Southern↗