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Biomedical subjects

J Manning

Publications and source records attributed to J Manning.

At least 91 records · Page 5Linked to original sources
PubMed1981

Early closure of the patent ductus arteriosus in very low-birth-weight infants: a controlled trial.

A controlled clinical trial comparing early closure (mean = 48.8 hours) of the patent ductus arteriosus using indomethacin to conventional medical management, with intervention only after cardiopulmonary decompensation (mean = 167.4 hours), was undertaken in 24 preterm infants with severe respiratory distress syndrome and evidence of PDA. An interval analysis of one-half the projected sample revealed that infants undergoing early closure of the PDA had significantly reduced occurrence of BPD or mortality by 6 months of age. A comparison of birth weight, Apgar scores, gestational age, age of initial PDA diagnosis, and fluid therapy during the first seven days of life showed no significant differences between early intervention and control groups. At the time of the interval analysis, there were no differences between the groups in duration of intermittent mandatory ventilation or oxygen exposure. Studies will be required to determine whether these and other variables can be altered by early closure of the PDA.

Bronchial Diseases↗
PubMed1980

Mixed mesodermal tumors of urinary bladder: prognosis and management.

Three cases of mixed mesodermal tumors of the urinary bladder characterized by the simultaneous occurrence of malignant epithelial and mesenchymal elements in the same tumor are reported. Integrated therapy consisting of preoperative radiotherapy followed by radical cystectomy is recommended. Chemotherapy is best withheld until the nature of any metastatic disease has been confirmed histologically in order that the appropriate drugs can be administered.

Aged↗
PubMed1979

Strand-specific attachment of avidin-spheres to double-stranded poliovirus RNA.

Poliovirus-specific double-stranded RNA molecules containing covalently attached protein were coupled with a biotin ester through the protein moiety. Subsequent interaction of the RNA-biotin with avidin attached to electronopaque plastic spheres led to the formation of complexes that were easily visualized in the electron microscope. Avidinspheres were associated only with one end of the RNA-biotin molecules, as seen in the electron microscope. Avidin-sphere attachment to poliovirus double-stranded RNA is strand specific, as shown by molecular hybridization of strand-specific probes to the separated strands of denatured complexes. [3H]DNA complementary to polio virion RNA hybridized exclusively to the strands bearing associated spheres [(+) strands] whereas 125I-labeled virion RNA hybridized predominantly with strands without spheres [(-)strands]. This biotin-avidin labeling technique provides a means for the isolation of full-length poliovirus (-) strands and may provide a general means for isolation of double-stranded polynucleotides containing tightly attached protein.

Avidin↗
PubMed1979

A collaborative study of infective endocarditis in the 1970s. Emphasis on infections in patients who have undergone cardiovascular surgery.

Twenty-six major cardiovascular centers participated in a cooperative study of all cases of infective endocarditis occurring during a single calendar year to obtain an overview of infective endocarditis. The study was designed to learn which patients appear to be at highest risk to develop this infection after palliative or reparative cardiovascular surgery. Of 278 patients developing infective endocarditis during the year at these medical centers, 63 (23%) had had previous cardiovascular surgery and 215 had not. Seventy percent of the 278 patients had recognized congenital or acquired heart disease before developing the infection. Rheumatic heart disease accounted for over half of the patients with underlying structural heart disease. A majority (55%) of the 63 patients who had been operated on before developing endocarditis had prosthetic valves inserted. Of those who did not require prosthetic valves, the majority had congenital heart disease with systemic artery-to-pulmonary artery shunts. Although these data were obtained from a selected group of patients, they confirm a significant risk of endocarditis in patients with prosthetic valves and suggest that in postoperative patients with non-valvular congenital heart disease, the highest risk appears to be in cyanotic patients with palliative pulmonary artery-to-systemic artery shunts.

Adolescent↗
PubMed1978

Current results with construction and interruption of the Waterston anastomosis.

The Waterston anastomosis was constructed in 21 infants and neonates between 1973 and 1977. Sixteen neonates were 1 week old or less and 8 were less than 24 hours old. There were 2 operative deaths, giving a hospital survival of 90%. There were 3 late deaths. All surviving infants received satisfactory palliation except 1 who required a Potts anastomosis one year later. During the same time interval, 9 other patients who had had a Waterston anastomosis underwent complete intracardiac repair. Seven of them had significant angulation of the right pulmonary artery necessitating patch reconstruction. All patients survived operation, and follow-up pulmonary angiograms demonstrated only a slight persistent narrowing of the right pulmonary artery in 2 patients. We conclude that the Waterston anastomosis can be constructed with a low operative mortality even in the severely cyanotic neonate and that it can be taken down at the time of complete repair with minimal morbidity and no mortality even if it has significantly angulated the right pulmonary artery.

Aorta↗
PubMed1978

Sequence arrangement of the 16S and 26S rRNA genes in the pathogenic haemoflagellate Leishmania donovani.

Kinetic and chemical analysis show that the haploid genome of Leishmania donovani has between 4.6 and 6.5 X 10(7) Kb pairs of DNA. Cot analysis shows that the genome contains 12% rapidly reassociating DNA, U3% middle repetitive DNA with an average reiteration frequency of 77 and 62% single copy DNA. Saturation hybridization experiments show that 0.82% of the nuclear DNA is occupied by rRNA coding sequences. The average repetition frequency of these sequences is determined to be 166. Sedimentation velocity studies indicate the two major rRNA species have sedimentation values of 26S and 16S, respectively. The arrangement of the rRNA genes and their spacer sequences on long strands of purified rDNA has been determined by the examination of the structure of rRNA:DNA hybrids prepared for electron microscopy by the gene 32-ethidium bromide technique. Long DNA strands are observed to contain several gene sets (16S + 26S). One repeat unit contains the following sequences in the order given: (a) A 16S gene of length 2.12 Kb, (b) An internal transcribed spacer (Spl) of length 1.23 Kb, which contains a short sequence that may code for a 5.8S rRNA, (C) 26S gene with a length of 4.31 Kb which contains an internal gap region of length 0.581 Ib, (d) An external spacer of average length 5.85 Kb.

Animals↗
PubMed1977

A method for gene enrichment based on the avidin-biotin interaction. Application to the Drosophila ribosomal RNA genes.

A method of enriching, from the total DNA of an organism, for long DNA strands carrying a particular gene is described. The purified RNA corresponding to the gene is covalently attached to biotin via a cytochrome c bridge. This modified RNA is hybridized to the total DNA. Those DNA strands which hybridize are separated from all the other DNA, using the avidin-biotin interaction, by one of two methods. Avidin is covalently attached to submicroscopic polymer spheres; the complexes of avidin spheres with the DNA: RNA-biotin hybrids band in CsCl at a much lower buoyant density than does free DNA. Alternatively, the DNA:RNA-biotin hybrids are isolated by affinity chromatography on an avidin-solid support column. These methods have been used to prepare long single strands of Drosophila ribosomal DNA (rDNA) in high yield and 42 to 80% pure.

Animals↗
PubMed1977

Sequence arrangement of the rDNA of Drosophila melanogaster.

The sequence arrangement of genes coding for stable rRNA species and of the interspersed spacers on long single strands of rDNA purified from total chromosomal DNA of Drosophila melanogaster has been determined by a study of the structure of rRNA:DNA hybrids which were mounted for electron microscope observation by the gene 32-ethidium bromide technique. One repeat unit contains the following sequences in the order given. First, an 18 S gene of length 2.13 +/- 0.17 kb. Second, an internal transcribed spacer (Spl) of length 1.58 +/- 0.15 kb. A short sequence coding for the 5.8S and perhaps the 2S rRNA species is located within this spacer. Third, the 28S gene with a length of 4.36 +/- 0.23 kb. About 55% of the 28S genes are unbroken or continuous (C genes). However, about 45% of the 28S genes contain an insertion of an additional segment of DNA that is not complementary to rRNA (l genes). The insertion occurs at a reproducible point 2.99 +/- 0.26 kb from the junction with Spl. The insertions are heterogeneous in length and occur in three broad size classes: 1.42 +/- 0.47, 3.97 +/- 0.55, and 6.59 +/- 0.62 kb. Fourth, an external spacer between the 28S gene and the next 18S gene which is presumably mainly nontranscribed and which has a heterogeneous length distribution with a mean length and standard deviation of 5.67 +/- 1.92 kb. Short inverted repeat stems (100-400 nucleotide pairs) occur at the base of the insertion. It is known from other studies that I genes occur only on the X chromosome. The present study shows that the I and C genes on the X chromosomes are approximately randomly assorted. The sequence arrangement on the plasmid pDm103 containing one repeat of rDNA (Glover et al., 1975) has been determined by similar methods. The I gene on this plasmid contains an inverted repeat stem. The occurrence of inverted repeat sequences flanking the insertion supports the speculation that these sequences are translocatable elements similar to procaryotic translocons.

DNA↗
PubMed1977

Automated identification of cardiac conduction tissue in L-TGV and Ebstein's anomaly.

The specialized cardiac conduction tissue was identified quickly and easily at operation in 2 patients with corrected transposition (L-TGV) and 1 with Ebstein's anomaly. In each of the former cases the tissue was located along the upper rim of the VSD, beneath the pulmonary outflow tract; in neither patient was there a disturbance in cardiac rhythm as a result of operation. In the patient with Ebstein's anomaly the bundle of His descended onto the ventricular septum more directly than was anticipated. There was only a transitory disturbance in atrioventricular conduction following tricuspid valve replacement. Accurate identification of the cardiac conduction tissue is a prerequisite to the safe repair of certain forms of complex congenital heart disease.

Adolescent↗
PubMed1977

Application of the avidin-biotin method of gene enrichment to the isolation of long double-stranded DNA containing specific gene sequences.

A method of enriching for long double-stranded segments of eukaryotic DNA carrying particular genes is described. A purified RNA coded for by the gene is covalently attached to biotin via the protein, cytochrome c. This modified RNA is hybridized to total nuclear, double-stranded DNA under conditions that allow the formation of R-loops. Avidin, which has a high affinity for biotin, is covalently attached to polymer spheres. The complexes of avidin-spheres with DNA:RNA-biotin R-loop hybrids band in CsCl at a much lower bouyant density than does free DNA. This density is a function of the length of DNA coupled per avidin-sphere. This method was used to prepare very long double-strands of DNA highly enriched in the coding sequences for the large rRNAs of D. melanogaster and L. donovani and the histone mRNAs of S. purpuratus.

Animals↗
PubMed1976

Urinary outputs of oxalate, calcium, and magnesium in children with intestinal disorders. Potential cause of renal calculi.

24-hour urinary outputs of oxalate, calcium, and magnesium have been determined in a total of 62 children aged 3 months to 17 years who fell into the following groups: (i) 16 normal controls, (ii) 3 with primary hyperoxaluria, (iii) 9 with small and/or large intestinal resections, (iv) 9 with untreated coeliac disease, (v) 5 with pancreatic dysfunction, and (vi) a miscellaneous group of 20 children with a variety of intestinal disorders. Taken as a whole, 58% of patients with intestinal disorders had hyperoxaluria, and of these 7% had urinary outputs of oxalate which fell within the range seen in primary hyperoxaluria. The proportion of children with hyperoxaluria in the different diagnostic groups was as follows: intestinal resections (78%), coeliac disease (67%), pancreatic dysfunction (80%), and miscellaneous (45%). 35% of the patients with hyperoxaluria had hypercalciuria, whereas magnesium excretion was normal in all subjects studied. In 2 patients treatment of the underlying condition was accompanied by a return of oxalate excretion to normal. These results indicate that hyperoxaluria and hypercalciuria are common in children with a variety of intestinal disorders, and that such children may be at risk of developing renal calculi without early diagnosis and treatment.

Adolescent↗
PubMed1976

The Waterston anastomosis with no deaths in the neonate.

The Waterston anastomosis has been performed with no deaths in 11 consecutive neonates during the past 24 months. Seven neonates had pulmonary atresia with either single ventricle or hypoplastic right ventricle, 3 had tetralogy of Fallot, and one had severe pulmonary stenosis with a normal right ventricle. Six neonates were one day old and only one was older than 7 days. All have obtained symptomatic and documented (increase Po2) benefit. This level of success is attributed to (1) minimal delay between the recognition of cyanosis and operation (mean time between hospital admission and catheterization was 3 hours and between catheterization and operation, 4 hours); (2) correction of any base deficit prior to, during, and after operation; (3) accurate construction of the anastomosis to avoid excessive size, and (4) careful postoperative management of the pulmonary subsystem by experienced personnel. We have demonstrated that the high mortality rate previously reported for the Waterston anastomosis in the neonate can be markedly improved by an appropriate patient management program.

Aorta, Thoracic↗