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D Leslie

Publications and source records attributed to D Leslie.

18 recordsLinked to original sources
PubMed1992

Gene probe assays on a fibre-optic evanescent wave biosensor.

This report describes experiments to detect oligonucleotide hybridization at the surface of a fibre-optic evanescent wave biosensor. Conditions were optimized and the time course of hybridization reactions were found to be very rapid compared to conventional hybridization assays. Binding was easily reversed by heating and the sensor surface could be reused many times. Short (16- and 20-mer) oligonucleotides bound to the waveguide surface could be used to detect fluorescein-labelled complementary sequences at the nanomolar level. Polymerase chain reaction was used to generate a 204-base oligomer that was attached to the waveguide surface. Fluorescein-labelled oligos bound at either the proximal or distal ends of this probe were found to give similar outputs.

Base Sequence↗
PubMed1989

Phospholipase C and haemolytic activities of Clostridium perfringens alpha-toxin cloned in Escherichia coli: sequence and homology with a Bacillus cereus phospholipase C.

The Clostridium perfringens alpha-toxin (phospholipase C) gene (cpa) has been cloned and expressed in Escherichia coli. The biological activities of the cloned gene product have been analysed and the complete nucleotide sequence of the cpa gene has been determined. The cloned cpa gene product, which is exported to the periplasm in E. coli, possesses both phospholipase C and haemolytic activities. Haemolysis is not apparent when cell extracts are incubated with isotonic suspensions of sheep erythrocytes, but can be detected and quantified readily when dilutions of the same extracts are placed in wells in sheep-blood agar plates. Like other sequenced clostridial genes, the cpa gene has a high AT content (66.4%), exhibits a strong bias for using codons with A or T in the wobble position, and the 350 base pairs upstream from the gene have a significantly higher AT content (79.5%) than the coding region. The cpa gene encodes a 398 amino acid polypeptide with a deduced molecular weight of 45,481 D. This is very similar to the estimated molecular weight (Mr) of the cpa primary gene product expressed in an in vitro transcription-translation system (Mr 46,000), but larger than the cpa gene product detected in E. coli minicells, E. coli whole cells or in C. perfringens cells (Mr 43,000), suggesting post-translational processing. The 28 N-terminal residues of the deduced alpha-toxin sequence possess the consensus features of a signal peptide and may be removed during secretion. The deduced alpha-toxin sequence shares significant structural homology with the phosphatidylcholine-preferring phospholipase C of Bacillus cereus.

Amino Acid Sequence↗
PubMed1988

Diagnosis of skin cancer in the general population: clinical accuracy in the Nambour survey.

The accuracy and validity of diagnoses of skin cancer that were made by experienced dermatologists in a Queensland community survey have been investigated. Histological examination confirmed 54% of 100 clinical diagnoses of basal-cell carcinoma, squamous-cell carcinoma or intraepidermal carcinoma. Clinical accuracy was higher for basal-cell carcinoma (59%) than for squamous-cell carcinoma (39%) or intraepidermal carcinoma (38%). Such levels of diagnostic accuracy are to be expected when an unselected population is surveyed because of the relatively low prevalence of skin cancer compared with that in the patient population of a specialist practice. This reduction in diagnostic accuracy is unrelated to clinical skills, and should be borne in mind when conducting any skin-cancer screening programme in the general community.

Adult↗
PubMed1988

Skin cancer in a Queensland population.

In the present study we have estimated the current prevalence of actinic skin disease in young and middle-aged adults in Queensland, Australia by surveying a representative community. It was found that 4.6% of persons aged 20 to 69 years had skin cancer, mostly basal cell carcinoma, and 40% had solar keratoses. The age distribution and site distribution of actinic lesions in this population were not as classically described; persons below age 40 years exhibited substantial sun-related skin damage, and a large proportion of actinic lesions occurred on sites other than the head, backs, of hands, or forearms. Allowing for age and sex, the strongest risk factors for skin cancer and solar keratoses were fair skin, as assessed by a dermatologist, and clinical signs of solar damage such as solar lentigines, facial telangiectasia, and actinic elastosis of the neck. Associations with self-reported tendencies toward sunburn, frequent painful sunburns, occupational sun exposure, and a previous history of skin cancer were confirmed.

Adult↗
PubMed1986

Choledochoscopy.

Explore the source record for details and available documents.

Common Bile Duct↗
PubMed1985

Hairy cell leukemia: a tumor of pre-plasma cells.

Monoclonal antibodies defining B-, T-, and myeloid-restricted cell surface antigens were used to characterize the lineage and state of differentiation of tumor cells isolated from 22 patients with hairy cell leukemia (HCL). These tumors were shown to be of B lineage because they strongly expressed the B cell-restricted antigens B1 and B4 and lacked T cell- and monocyte-restricted antigens. Moreover, the strong expression of the plasma cell-associated PCA-1 antigen on the majority of hairy cells suggested that these tumors correspond to later stages of B cell ontogeny. Dual fluorescence experiments further confirmed that HCL splenocytes that coexpressed B1 and PCA-1 demonstrated both the morphology and tartrate-resistant acid phosphatase positivity of hairy cells. The observation that some hairy cells either spontaneously produce immunoglobulin (Ig) or could be induced to proliferate and secrete Ig provides complementary support for the view that HCL is a pre-plasma cell tumor. However, staining of hairy cells with anti-IL2R1 monoclonal antibody, which is directed to the T cell growth factor receptor and/or with the anti-Mo1 reagent, directed to C3bi complement receptor, distinguish these cells from currently identified B cells.

Antibodies, Monoclonal↗
PubMed1978

The "yo-yo" operation for inguinal hernia.

This article presents a new principle in the repair of difficult inguinal herniae. The testis is mobilized from the scrotum, returned to the abdominal cavity, brought down again through a new canal constructed through the rectus abdominis muscle, and then restored to the scrotum. The original inguinal canal can then be completely obliterated.

Hernia, Inguinal↗
PubMed1978

Normal alkaline phosphatase in primary biliary cirrhosis.

A patient with primary biliary cirrhosis is described. Throughout her illness the serum alkaline phosphatase remained normal and this unique feature emphasizes the importance of histology in diagnosing the disease.

Alkaline Phosphatase↗
PubMedDate not supplied

Hemifacial spasm: MR imaging features.

MR imaging was used to evaluate the relationship of the root exit zone of the seventh cranial nerve to surrounding vascular structures in 13 patients with clinically documented hemifacial spasm and in 70 asymptomatic patients. MR imaging clearly demonstrated the course of the seventh nerve from the root exit zone of the brainstem to the internal auditory canal and its relationship to the surrounding vertebrobasilar system. The presence of a vascular structure at the root exit zone of the seventh nerve was identified in all 13 patients with hemifacial spasm. In the 70 asymptomatic patients, examination of 140 seventh nerves revealed that 21% had contact by a vascular structure at the root exit zone of the seventh nerve. Our results indicate that although neurovascular contact may be asymptomatic, MR demonstration of a vascular structure at the root exit zone of the seventh cranial nerve in a patient with hemifacial spasm may implicate neurovascular compression as the cause of symptomatology. This finding may alter therapeutic management. Because of the inherent limitations of CT in the visualization of posterior fossa structures, MR imaging should be considered the initial screening procedure in the assessment of patients with hemifacial spasm.

Adult↗