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Biomedical subjects

R Thompson

Publications and source records attributed to R Thompson.

At least 343 records · Page 19Linked to original sources
PubMed1979

The role of chemotherapy in the management of fungal endocaridits following homograft valve replacement.

Initial intensive combined chemotherapy, with late re-operation when indicated, appears to give better results than immediate excision of the infected valve. The combination chemotherapy used in this series was amphotericin B (up to 100 mg/patient/day) and flucytosine (up to 12 g/patient/day). Serious side effects attributed to this chemotherapy were extremely rare. Candida infections were the most common and the Aspergillus infections were uniformly fatal. Embolectomies and excisions of large mycotic aneurysms were generally successful. Re-operation for late valve malfunction was common and yielded satisfactory results.

Amphotericin B↗
PubMed1979

Genetic and environmental variation in the LH response of ovariectomized sheep to LH-RH.

The influence of breed and season on the sensitivity of the pituitary gland of sheep to LH-RH was assessed. Ovariectomized ewes of 3 breeds (Finnish Landrace, Scottish Blackface and Tasmanian Merino) with differing normal breeding seasons and with differing ovulation rates were injected (i.v.) with 3 doses of LH-RH (1.56, 6.25 or 25.0 micrograms) at 3 different times of the year covering the anoestrous and the breeding seasons of intact ewes; 9 ewes of each breed (3 per sub-class) were examined on the first and third occasions, 6 (2 per sub-class) on the second. The response was measured in terms of the concentration of LH in peripheral plasma 20, 40, 60 and 80 min after injection. Time of year, but not the breed of sheep, affected the magnitude of the response; the data indicated that the duration of LH secretion was greater during the breeding season than during anoestrus. It was concluded that changes in the spontaneous activity of the hypothalamus/hypophysis could contribute to seasonal changes in LH secretion independently of the modifying effects of gonadal steroids. Such variation in unmodulated activity apparently does not contribute to the differences in ovulation rate among the 3 breeds.

Animals↗
PubMed1979

Influence of preoperative left ventricular function on results of homograft replacement of the aortic valve for aortic regurgitation.

The effect of preoperative left ventricular function on eraly and late prognosis was assessed in 69 patients with aortic regurgitation who underwent homograft replacement of the aortic valve. Patients were divided into two groups: Group A (38 patients) had an ejection fraction of 0.46 or more and Group B (31 patients) had an ejection fraction of 0.45 or less. Clinical data, hemodynamic data, and operative results were compared in the two groups. In Group A there was one early death (2.6%) and there were two late deaths (5.3%) compared to two early deaths (6.5%) and seven late deaths (22.6%) in Group B during a follow-up period of 13 to 98 months (mean, 49 months). Actuarial analysis showed a 94% survival at 6 years in Group A compared to 80% in Group B. Twenty-four patients were reinvestigated by repeat cardiac catheterization and coronary angiography at a mean time of 38 months following valve replacement. Left ventricular function was assessed by computerized quantitative radial analysis of segmental wall motion. Improvement in left ventricular function occurred in eight of the 14 patients reinvestigated in Group B, and appeared to be closely related to the etiology of the initial valve lesion. Despite the higher mortality rate in patients with poor left ventricular function, most derived considerable benefit from operation.

Adolescent↗
PubMed1978

The control region of the F sex factor DNA transfer cistrons: restriction mapping and DNA cloning.

A restriction endonuclease map of EcoRI fragment f6 of F sex factor DNA was constructed and aligned with pre-existing physical and genetic maps. Results of genetic complementation tests and analysis of proteins synthesized in minicells from PstI and BglII sub-fragment clones, or from a specific BglII fragment deletion, have allowed mapping of the locations of the origin of DNA transfer and many of the transfer genes known to lie on f6. The proteins detected account for 78% of the coding capacity of fragment f6.

Chromosome Mapping↗
PubMed1978

Ultrasonography of abdominal fluid collections.

Ultrasonic examination of abdominal fluid collections sometimes allows identification of the nature of the contained fluid. Abscesses, hematomas, and lymphoceles tend to be ellipsoidal unless confined by particularly resistant structures. Abscesses often contain fine debris. Hematomas develop coarse clumps of strongly echoing material as they age. Lymphoceles have sharp walls and are echo-free. Ascites has an irregular outline, a sharply defined wall, and is echo-free. There may be bowel loops floating in it. Pseudocysts have a widely variable appearance. Bowel loopes that are distended with fluid often show peristalsis. Ultrasonically directed fine needle puncture allows confirmation of the nature of the fluid.

Abdomen↗
PubMed1978

Assignment of tra cistrons to EcoRI fragments of F sex factor DNA.

We describe here the cloning of single EcoRI fragments from the tra region of F DNA using ColE1::Tn3 as vector. These plasmids, as well as the series of Skurray et al. (Proc. Natl. Acad. Sci. U.S.A. 73:64-68, 1976), have been used to refine the map positions of tra cistrons on the F factor as well as to define a new DNA transfer cistron, traM. The current map of the tra cistrons is presented. None of the known tra cistrons, with the exception of traG, straddles an EcoRI site. The EcoRI site at 82 kilobases splits the traG cistron into two portions, an operator-proximal portion necessary for F pilus synthesis and an operator distal portion involved in conjugation itself. The operon structure of the tra cistrons was reevaluated, and we found that traI is at least partially independent of transcription of the traA to traD operon.

Conjugation, Genetic↗
PubMed1977

The modern enigma of radiation enteropathy: sequelae and solutions.

With the extended indications for abdominal and pelvic radiation therapy, administered at higher dosage levels, an increased incidence of radiation injury to the intestine can be anticipated. Increased efforts are urgently needed to develop innovative methods in the detection, prevention, and management of radiation-induced intestinal injury. Fifty cases of radiation enteropathy have been reviewed to highlight problems in management and to suggest preventive and therapeutic measures, both surgical and nonsurgical.

Abdominal Neoplasms↗
PubMed1977

Evolutionary changes in the electrocardiogram of severe progressive hypothermia.

A patient is reported who developed progressive hypothermia during therapy for adult respiratory distress syndrome. Electrocardiographic changes (sinus bradycardia, prolonged PR interval, prolonged QTc interval, "Osborn waves") were documented and correlated with body temperature. The significance of these changes is discussed and the relationship between the degree of hypothermia and the presence of "Osborn waves" is noted.

Adult↗
PubMed1977

The use of "fresh" unstented homograft valves for replacement of the aortic valve: analysis of 6 1/2 years experience.

Between August 1969 and January 1976, 561 patients underwent homograft replacement of the aortic valve (AVR). Isolated AVR was performed in 339 patients, ranging in age between 18 months and 74 years. The valves were sterilized in antibiotic solution and preserved at 4 degrees C in tissue culture medium. There were 11 early deaths (3.2%) and 23 late deaths (6.8%). Actuarial analysis showed 88% survival at 5 years and 85% at 6 years. Valve failure occurred in 13 patients (3.8%) due to prolapse of one cusp in five patients (1.5%), infective endocarditis in three and degeneration of the graft in five (1.5%). Degenerative valve failure was encountered after the fourth year with an incidence of 3.5% of patients at risk, and occurred only in grafts from donors over the age of 70 years. Diastolic murmurs were present in 22% of patients followed up for more than one month and increased very slightly with time. The clinical result was judged to be good or excellent in approximately 90% of the surviving patients.

Adolescent↗
PubMed1976

Meningitis due to combined infections. Association of Haemophilus influenzae type B and Clostridium perfringens.

Haemophilus influenzae type B and Clostridium perfringens were recovered simultaneously from the cerebrospinal fluid of a patient with purulent meningitis. No antecedent history of head trauma was present to explain the coexistence of the anaerobe with Haemophilus organisms. A review of the literature on mixed meningitis indicates that no previous cases of anaerobes have been reported in uncomplicated meningitis due to multiple organisms. In addition, the recovery of clostridia is extremely unusual in the absence of an identifiable portal of entry. We have identified two additional cases of clostridia infection in the central nervous system and recommend that anaerobic organisms be considered in selected cases of meningitis.

Ampicillin↗
PubMed1976

The estimation of maternal genetic variances.

The estimation of maternal genetic variances by a multivariate maximum likelihood method is discussed. As an illustration the method is applied to data on Tribolium using a model based on partitioning the maternal genetic effect into additive and dominance components. An alternative model due to Falconer (1965) is also fitted. The method is applied to designs suggested for estimating maternal variances by Eisen [1967]. Modifications required when parents are selected on their phenotypic values are given.

Analysis of Variance↗