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Biomedical subjects

J M Manners

Publications and source records attributed to J M Manners.

At least 55 records · Page 3Linked to original sources

Inheritance of random amplified polymorphic DNA markers in an interspecific cross in the genus Stylosanthes.

The inheritance of random amplified polymorphic DNA (RAPD) markers generated via the polymerase chain reaction amplification of genomic DNA sequences in an F2 family of an interspecific cross between Stylosanthes hamata and S. scabra was investigated. An initial comparison between the parental species, S. hamata cv. Verano and S. scabra cv. Fitzroy, demonstrated that 34% of detected RAPD bands were polymorphic. Of 90 primers tested, 35 showed relatively simple and reliably scorable polymorphisms and were used for segregation analysis. Sixty F2 individuals were scored for the segregation of 73 RAPD markers and 55 of these markers fit a 3:1 ratio. Segregation of eight other RAPD markers deviated significantly from a 3:1 ratio. There was no bias in the inheritance of RAPD markers regarding parental origin of the segregating RAPD markers. Linkage analysis revealed 10 linkage groups containing a total of 44 RAPD loci. Another 10 RAPD markers (7 of maternal origin) that were polymorphic between the parents did not segregate in the F2 population. One of the maternally inherited RAPD bands hybridized to chloroplast DNA. Analysis of RAPD loci by DNA hybridization indicated that mainly repeated sequences were amplified. These data indicate that RAPDs are useful genetic markers in Stylosanthes spp. and they may be suitable for genetic mapping.

Base Sequence↗

Induction of beta-1,3-glucanase in barley in response to infection by fungal pathogens.

The sequence of a partial cDNA clone corresponding to an mRNA induced in leaves of barley (Hordeum vulgare) by infection with fungal pathogens matched almost perfectly with that of a cDNA clone coding for beta-1,-3-glucanase isolated from the scutellum of barley. Western blot analysis of intercellular proteins from near-isogenic barley lines inoculated with the powdery mildew fungus (Erysiphe graminis f. sp. hordei) showed a strong induction of glucanase in all inoculated lines but was most pronounced in two resistant lines. These data were confirmed by beta-1,3-glucanase assays. The barley cDNA was used as a hybridization probe to detect mRNAs in barley, wheat (Triticum aestivum), rice (oryza sativus), and sorghum (Sorghum bicolor), which are induced by infection with the necrotrophic pathogen Bipolaris sorokiniana. These results demonstrate that activation of beta-1,3-glucanase genes may be a general response of cereals to infection by fungal pathogens.

Ascomycota↗

Genes from Cellvibrio mixtus encoding beta-1,3 endoglucanase.

Two genes encoding beta-1,3 glucanase activity were cloned from the gram-negative soil bacterium Cellvibrio mixtus. The two clones, designated cwd (cell wall degradation) and lam (laminarin degradation), had distinct endonuclease restriction patterns and encoded enzymes with distinct substrate specificities. The 3.7-kilobase cwd insert encoded an enzyme which degraded yeast cell walls as well as the soluble beta-1,3 glucan laminarin and the insoluble beta-1,3 glucans zymosan and pachyman. The 1.8-kilobase lam insert encoded an enzyme which degraded laminarin only. Both enzymes degraded laminarin in an endohydrolytic manner to yield laminarobiose, laminarotriose, and laminarotetraose as major end products. Radiolabeled translation products of the cwd and lam transcripts were identified.

Bacterial Proteins↗

Open heart surgery in the first 24 hours of life.

The results of open heart surgery in infants have steadily improved. The performance of corrective surgery very early in life has thereby been encouraged. We report four patients who underwent successful surgical correction within 24 h of birth. Two patients with total anomalous pulmonary venous drainage and one patient with pulmonary atresia and intact septum were corrected with the aid of profound hypothermia by the combined surface and bypass cooling technique. Cardiopulmonary bypass alone was used for the fourth patient with aortic stenosis. The usual surgical techniques can be applied successfully to infants even within 24 h of life.

Aortic Valve Stenosis↗

Decrease in Three Messenger RNA Species Coding for Chloroplast Proteins in Leaves of Barley Infected with Erysiphe graminis f. sp. hordei.

Cloned hybridization probes have been used to investigate the effect of infection of susceptible Hordeum vulgare cv Prior by Erysiphe graminis f. sp. hordei on the abundance of host mRNAs coding for the large (LSU) and precursor to the small (SSU) subunits of ribulose 1,5-bisphosphate carboxylase/oxygenase and the rapidly metabolized 32kD thylakoid protein (32kDP). In leaf RNA preparations from control (noninoculated) plants the amount of mRNA for the LSU and SSU declined from 7 to 11 days after sowing, whereas that for the 32kDP increased over this period. Following inoculation at 6 days after sowing, the abundance of each of the mRNA species was significantly reduced below that of controls at 1, 3, and 5 days later. Results indicate that infection causes a rapid and extensive reduction in host mRNA species coding for proteins with important photosynthetic functions.

Journal Article↗

Left ventricular aneurysm. The Wessex experience.

One hundred patients with left ventricular aneurysms were operated on between February 1973 and January 1983. The principal indications for operation were left ventricular failure in 58, angina in 23, both in 17, with arrhythmia and systemic emboli accounting for one case each. Eighty five had had anterior infarction causing 82 anteroapical and three lateral aneurysms, while the remainder had had inferior infarcts resulting in 14 inferior aneurysms and one lateral aneurysm. Coronary angiography detected a single coronary lesion in 46%. Three patients had aneurysmal plication and the remainder had aneurysmectomy. Eleven mitral valve replacements were performed. Forty patients underwent coronary artery bypass grafting with a mean number of grafts per patients of 1.4. The early mortality was 7% with no early deaths since 1978. The actuarial five year survival was 68%, and 82% of survivors are in New York Heart Association class I or II (mean follow up three years). Left ventricular aneurysmectomy may be performed with a low operative mortality and good long term results.

Coronary Artery Bypass↗

Cardiac surgery in Wessex.

The results of 3000 consecutive operations using cardio-pulmonary bypass show that the overall early mortality was 6.1%, dropping from 8.9% in the first 1000 to 4.4% in the third 1000. Operations for valve disease have been the most common, the early mortality for aortic valve replacement being 3.1% and for mitral valve replacement 2.9%. Combined aortic and mitral valve replacement had an early mortality of 4.4%. The number of patients undergoing isolated coronary artery bypass grafting has increased from 59 in the first 1000 to 292 in the third 1000 operations, with an overall early mortality of 1.3%. Six hundred and ninety seven patients underwent surgery for congenital heart disease with an overall early mortality of 10.9% (7.5% in the last 2000 cases). The patients have been followed up from one to 8.5 years. A high proportion have returned to work and enjoy a normal life. At the time of review, 87% of the 3000 patients were alive. Long waiting times for outpatient and inpatient care indicate underprovision of facilities relative to regional demand.

Adolescent↗

Vascular resistance during cardiopulmonary bypass. Its effect on cardiac performance in the immediate post-bypass period.

A clinical study was undertaken to measure changes in systemic vascular resistance during cardiopulmonary bypass in 56 adults. Forty-five patients showed a rise in systemic vascular resistance and 77% required no inotropic support in the immediate post-bypass period. Eleven of the 33 patients undergoing valve replacement surgery showed only a small increase or an actual decrease in systemic vascular resistance and required inotropic support. These results were statistically significant. Factors affecting cardiac performance are discussed.

Cardiopulmonary Bypass↗

Osmolal excretion after open heart surgery.

Water and osmolal balance was investigated during the peri-operative period in twenty unselected adult patients presenting for open heart surgery. On the day before surgery the mean urine output was 1.13 litres/sq m/24 hours and osmolal output 430 mOs/sq m/24 hours. Using a haemodilution cardiopulmonary bypass technique, patients received 2.62 litres/sq m and 792 mOs/sq m in the operating room. The pattern of excretion of this water and solute load was identified. Patients were still in positive balance on the day following surgery despite a considerable diuresis, with solute retention exceeding water retention.

Adult↗

Acquired ventricular septal defect.

The past 9 years' experience with ventricular septal rupture complicating myocardial infarction has been reviewed. Thirty-six patients were treated surgically, with 10 early deaths (28%) and one late death, for an 8 year actuarial survival rate of 63%. The mortality was highest for those defects which followed inferior infarction, 38% compared with 13% following anterior infarction. The infarction-operation interval also greatly influenced mortality; under 2 weeks, 43%; over 2 weeks, 18%. Concomitant coronary artery bypass grafts (13 patients) or left ventricular aneurysmectomy (14 patients) did not carry an increased mortality. Of 17 patients who presented with cardiogenic shock, eight died (47%). The intra-aortic balloon pump (IABP) was used in 16 patients (44%) and helped greatly in the management of the critically ill. With an estimated 17 acquired septal defects occurring each year in persons under 65 years of age in Wessex, awareness of this complication and of the favorable outcome of operation is essential among those who treat the aftereffects of myocardial infarction.

Aged↗

Magnesium flux during open heart surgery. The effect of St Thomas' Hospital cardioplegia solution.

The Hearse St Thomas' Hospital cardioplegia infusate is one method of preserving the myocardium in the absence of coronary perfusion, during open heart surgery. The infusate contains 16 mmol magnesium/litre and 20 mmol potassium/litre. Peri-operative plasma magnesium levels and urinary excretion of magnesium have been measured, when the infusate was returned to the circulation in 12 patients. The plasma level (+/- SEM) rose to 1.86 mmol/litre (+/- 0.1) 5 minutes after cardiopulmonary bypass commenced, was 1.57 mmol/litre (+/- 0.09) shortly before termination of cardiopulmonary bypass but was normal on the first day after surgery. Urinary excretion of magnesium was 55% of the administered quantity by Day 1 and 77% by the second day. Two patients excreted less than 40% of the administered magnesium within 24 hours probably indicating magnesium depletion. There were no adverse effects from a magnesium load of 16--32 mmol magnesium given during cardiopulmonary bypass.

Adult↗

Corrective cardiac surgery in infants. A review of 136 patients including the contribution of postoperative ventilation.

This is a review of 136 patients who have undergone corrective surgery for congenital heart disease with the aid of profound hypothermia in a 6-year period. Almost all patients were less than one year old and less than 10 kg. In 1979 the average age was 3.4 months and the average weight was 4.1 kg in 34 infants. The hypothermic technique consisted of surface cooling followed by cardiopulmonary bypass cooling and circulatory arrest during definitive surgery. The hospital mortality was 26% for the whole period, having decreased from 53% in 1974 to 15% in 1979. After operation 70% of patients with uncomplicated ventricular septal defect or the tetralogy of Fallot were extubated within 4 hours, 65% of all patients were extubated within 12 hours of operation.

Anesthesia, General↗

Cor pulmonale and the Pierre Robin anomaly. Airway management with a nasopharyngeal tube.

An infant with Pierre Robin anomaly was anaesthetised for cardiac catheterisation. There was cor pulmonale with the pulmonary artery pressure at systemic level, a patent foramen ovale and a persistent ductus arteriosus. The effects of alterations in blood gases on the haemodynamics and intracardiac shunts are considered. Subsequent management of the obstructed airway with a nasopharyngeal tube for 4 weeks is described.

Airway Obstruction↗