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J M Carson

Publications and source records attributed to J M Carson.

7 recordsLinked to original sources
PubMed1995

Genetic analysis of dermatophilus spp. using multilocus enzyme electrophoresis.

Multilocus enzyme electrophoresis was used to examine a collection of 41 mainly Australian isolates of Dermatophilus congolensis that had been cultured from sheep, cattle, horses, a goat, a marsupial and Chelonids. Allelic variation was examined at 16 enzyme loci. The isolates were divided into eight distinct electrophoretic types (ETs) with a mean genetic diversity per locus of 0.41. The three isolates from Chelonids represented a distinct clone in ET 1 which was separated from the remaining cluster of isolates of D. congolensis by a genetic distance of 0.852. These findings supported a previous proposal that the isolates from Chelonids represent a new species of Dermatophilus. The other 38 D. congolensis isolates were separated into two divisions (I and II) by a genetic distance of 0.560. The divisions were both subdivided into groups that either only contained alpha-hemolytic or beta-hemolytic isolates, but all isolates in each ET had only one hemolytic pattern. Isolates originating from the same animal species, or from the same geographic location, were not all closely related genetically. The allocation of isolates into ETs correlated well with their distribution into DNA restriction endonuclease analysis patterns previously established for the collection. Although relatively few distinct strains of D. congolensis were identified amongst the collection, significant genetic diversity existed within this population.

Actinomycetales↗
PubMed1995

Dermatophilus chelonae sp. nov., isolated from chelonids in Australia.

Three isolates of a previously undescribed Dermatophilus sp. obtained from chelonids (two strains obtained from turtles and one strain obtained from a tortoise) were compared with 30 Dermatophilus congolensis isolates obtained from Australian mammals. The microscopic appearance, the colony morphology, and most biochemical test results for the chelonid isolates were characteristic of the genus Dermatophilus. Our isolates differed from the mammalian D. congolensis isolates in a number of cultural characteristics, including faster growth at 27 degrees C than at 37 degrees C, formation of two hemolysis zones around colonies on blood agar at 37 degrees C in the presence of 10% CO2, poor motility, and production of a distinctive odor. The DNA restriction enzyme digestion and protein electrophoresis patterns of our strains were distinct. The electrophoretic mobilities of 11 enzymes differed from the mobilities observed with D. congolensis strains. A monoclonal antibody to a surface antigen of an ovine isolate did not react with zoospores or filaments of the chelonid isolates. Biochemical differences between our isolates and D. congolensis included the ability of the chelonid isolates to reduce nitrate to nitrate and the fact that the chelonid isolates exhibit collagenase activity in vitro. We propose that the chelonid isolates should be placed in a new species, Dermatophilus chelonae. Strain W16, which was isolated from a nose scab on a snapping turtle, is the type strain; a culture of this strain has been deposited in the American Type Culture Collection as strain ATCC 51576.

Actinomycetales↗
PubMed1993

Variation in cultural, morphological, biochemical properties and infectivity of Australian isolates of Dermatophilus congolensis.

Recent vaccination studies with Dermatophilus congolensis showed that variation of challenge strains had a considerable influence on protection afforded by the vaccines. In this study cultural, morphological and biochemical properties of 30 D. congolensis isolates from throughout Australian were investigated. The infective dose required to produce lesions of equivalent severity by these isolates for sheep, rabbits and guinea pigs was also examined and the isolates were grouped into four clusters of similar infectivity ranking. Analysis of the relationship between cultural, morphological and biochemical characteristics and infectivity rankings of clusters was undertaken to determine if certain properties were linked to infectivity. Considerable variability was found in haemolytic activity on blood agar, mucoid nature of colonies, motility, flagella density and polarity, capsule width, restriction enzyme profiles of bacterial DNA, protein electropherotype, carbohydrate content, and enzymic activity against proteins, maltose, chondroitin-4-sulphate, phospholipids and lipids. Of these properties haemolytic activity and enzyme activity against casein, chondroitin-4-sulphate and lipids showed some link with infectivity ranking for these isolates.

Actinomycetales↗
PubMed1985

Conformational analysis and active site modelling of angiotensin-converting enzyme inhibitors.

The discovery of captopril as a potent, orally active inhibitor of angiotensin-converting enzyme (ACE) led to the recent development of many series of novel structures with similar biological activity. To date, however, all of these inhibitors are flexible or semiflexible molecules, and there is therefore no clear definition of the conformational requirements for ACE inhibition. In an effort to solve this problem, we have carried out conformational energy calculations on a series of eight structurally diverse ACE inhibitors. Comparison of the low-energy conformations available to these molecules leads to the conclusion that there is a common low-energy conformation throughout the series. The calculations thus define the structural and conformational requirements for ACE inhibition. Expansion of this model to the receptor level has been achieved by considering possible alternative receptor sites for each of the molecules in its proposed biologically active conformation and leads to an active-site model for ACE which may be useful for the design of further inhibitors.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1982

Surgical treatment of low grade soft tissue sarcomas.

Nineteen patients who have undergone surgical resection of low grade soft tissue sarcomas were retrospectively reviewed. Four patients received additional radiation therapy, and 15 did not. Of the 15 patients treated by surgery alone, 4 had positive margins in the original specimen; all 4 had local recurrence within a mean of 42 months. Eleven patients had negative margins. Ten have had no recurrence in a mean of 40 months. One patient had local recurrence at 36 months. Two of the four patients with positive margins were reoperated on and in achieving negative margins have remained disease-free a mean of 84 months. Three patients receiving additional postoperative radiation therapy had positive margins, and all had recurrence in a mean of 36 months. One patient with negative margins who also received radiation therapy is disease-free at 144 months. It appears that tumor-positive margins are associated with a high likelihood of local recurrence, whereas negative margins appear associated with a long disease-free interval and possible cure. Radiation therapy to positive margins did not prevent local recurrence.

Adolescent↗
PubMed1982

Preoperative determination of susceptibility to malignant hyperthermia.

A careful individual and family history is of utmost importance in evaluating MH susceptibility. Patients having myopathy with or without a significant family history of MH must be suspected of having the condition. The initial evaluation should include routine blood studies and CPK determinations in addition to an electrocardiogram. Full evaluation differentiating rigid from nonrigid types must include a muscle biopsy for microscopic and contraction studies. Platelet ATP depletion with exposure to halothane shows promise as a prescreening test. Susceptible patients can be given both general and local anesthetics if the surgeon and support personnel have a thorough understanding of MH and if proper precautions have been taken and preparation of facilities has been made.

Adolescent↗