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L Douglas

Publications and source records attributed to L Douglas.

29 records · Page 2Linked to original sources

Cloning and expression of cystolic phospholipase A2 (cPLA2) and a naturally occurring variant. Phosphorylation of Ser505 of recombinant cPLA2 by p42 mitogen-activated protein kinase results in an increase in specific activity.

Full-length cytosolic phospholipase A2 (cPLA2) was cloned from U937 cells and polymorphonuclear leukocytes (PMNLs) while a naturally occurring variant of cPLA2, which lacks residues Val473-Ala749 but has a C-terminal extension of ILMNLSEYMLWMSKVKRFM (DcPLA2) was cloned from PMNLs and mononuclear leukocytes. We were unable to clone DcPLA2 from U937 cells. When cPLA2 and DcPLA2 were expressed in insect cells, both proteins were detected in cell lysates by SDS/PAGE as single bands of apparent molecular masses 100 kDa and 57 kDa, respectively. Full-length cPLA2 was phosphorylated stoichiometrically by p42 mitogen-activated protein (MAP) kinase in vitro at a similar rate to other physiological substrates of this protein kinase and the major site of phosphorylation was identified by amino acid sequencing as Ser505. [32P]Ser(P)505 in cPLA2 was only dephosphorylated at a slow rate by mammalian tissue homogenates. Protein phosphatases 2A, 2B and 2C all contributed significantly to the overall dephosphorylation of cPLA2. The phosphorylation of cPLA2 by p42 MAP kinase correlated with an approximately 1.5-fold increase in specific enzyme activity which was reversed by dephosphorylation.

Amino Acid Sequence↗

Combination alkali/thermal burns caused by 'black liquor' in the pulp and paper industry.

Three patients are presented, who sustained a unique type of burn injury while working in the pulp and paper industry in Canada. These patients suffered combination chemical (pH 11-13) and thermal (85-95 degrees C) injuries, when they were exposed to 'black liquor'--a solution which is used in the pulp and paper industry to convert wood chips to pulp. Black liquor can rapidly cause devastating thermal-corrosive burns to the skin, eyes, lungs, and upper gastrointestinal tract. One patient sustained a relatively minor, full skin thickness 3 per cent body surface area (BSA) injury to both feet and lower legs. The second patient, who was sprayed with the heated black liquor solution, sustained a full skin thickness injury to 40 per cent BSA and also suffered virtual loss of vision in one eye. The third patient, who was also sprayed with the solution, sustained a 98 per cent full skin thickness burn and severe inhalation injury, and died during day 1 postburn. Photographic documentation of all three patients is presented. The principles of treatment of this type of burn injury are reviewed. All of these burns were preventable.

Accidents, Occupational↗

Toxic epidermal necrolysis: a burn-centre challenge.

OBJECTIVE: To describe the clinical features and outcome of patients with toxic epidermal necrolysis. DESIGN: Case series. SETTING: Ross Tilley Burn Centre, Wellesley Hospital, Toronto. PATIENTS: Ten patients (seven women) with toxic epidermal necrolysis referred to the centre from 1984 to 1990. INTERVENTION: Biobrane (Winthrop Pharmaceuticals, New York) was applied to all raw surfaces after the epidermis had been completely separated. It was not removed until the epidermis had regenerated. MAIN RESULTS: The age of the patients varied from 27 to 90 (mean 45) years. The proportion of body surface area involved was 20% to 95% (mean 58.5%). Nine of the patients had received steroids and antibiotics prophylactically before being referred to the burn centre; the steroids were immediately tapered and the antibiotics withdrawn unless there was a specific infection. Urinary tract infection developed in seven patients, respiratory failure in six and systemic sepsis in six. All of the patients ultimately required antibiotics for treatment of systemic infections. Two patients died; both had severe illness before the onset of the toxic epidermal necrolysis. Biobrane provided a marked reduction in pain, eliminated the need for further dressings and allowed early, aggressive physiotherapy. The wounds healed completely within 14 to 21 days, with no significant scarring or need for skin grafting. CONCLUSIONS: The use of a temporary skin substitute is recommended for the treatment of toxic epidermal necrolysis. There is no indication for prophylactic steroid or antibiotic therapy; indeed, such therapy is probably contraindicated.

Adult↗

Penile prostheses in the management of impotence in sickle cell disease.

Priapism lasting more than 24 h in adults with homozygous sickle cell disease usually results in impotence. The dense fibrosis of the corpora cavernosa which destroys the normal vascular erectile system of the penis also complicates insertion of penile prostheses. Our experience in 5 patients is reviewed. Sharp dissection and dilatation were necessary to form a tunnel for the prosthesis, which was more easily excavated anteriorly and posteriorly through a dorsal incision than for the length of the corpora through a traditional perineal-scrotal incision. Damage to the tunica was common and subsequent migration of the prosthesis necessitated an additional 11 procedures under general anaesthesia. Despite these technical difficulties, the procedure allowed satisfactory intercourse. The average interval between onset of impotence and implantation was 4 years. Early implantation before the dense fibrosis develops might give more satisfactory results.

Adult↗

What chance did Mendel's experiments give him of noticing linkage?

The a priori probability of noticeable linkage among all conceivable experiments of the size reported by Mendel cannot reasonably be taken as greater than 24-36 per cent; and therefore, the frequently heard opinion that his chances of encountering linkage were high, approaching 99-4 per cent, appears to be mistaken.

Chromosomes↗

Substance use disorders in young adults with and without LD: predictive and concurrent relationships.

This article reports on young people with and without learning disabilities (LD) and substance use disorders (SUD). Participants were assessed for LD at ages 12 and 19 and for SUD and psychiatric disorders at age 19. Participants with LD at ages 12 and 19 were more likely to develop an SUD or a psychiatric disorder compared to participants without consistent LD. Participants with LD at age 19 were more likely to have a concurrent SUD or psychiatric disorder compared to those without LD at age 19, while participants with LD at age 12 showed only a trend toward increased rates of SUD at age 19 when compared to participants without LD at age 12. Participants with and without LD did not differ in substance use, consumption levels, or onset history. In a multivariate model, adolescent LD was associated with a three-fold increased risk for SUD after behavioral problems and family structure had entered the model. Although these results provide some support for the notion that adolescents with LD are at increased risk for SUD, LD also appears to confer a general risk for adverse outcomes.

Adolescent↗