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Biomedical subjects

C Driver

Publications and source records attributed to C Driver.

11 recordsLinked to original sources
PubMed2001

The Gompertz function does not measure ageing.

The Gompertz transform of the distribution function for the age at death expresses mortality in a form R = R0e(alphat) where R0 is the mortality at time zero and alpha is the rate of increase of mortality, frequently taken as the rate of ageing. The slope of the line alpha is frequently used as a measure of the rate of ageing. It is argued that it is incorrect to use alpha in this way. To support this contention, a paradox is produced whereby selection for longevity increases alpha, which could lead to the absurd conclusion that selection for longevity increases the rate of ageing.

Aging↗
PubMed2001

Trans-pyeloureteric anastomosis in the management of pelviureteric junction obstruction.

BACKGROUND: The application of pyeloureteric anastomoses in the management of pelviureteric junction obstruction is described. METHODS: Two patients, one requiring a ureterocystoplasty for bladder augmentation but with a coexistent contralateral pelviureteric junction (PUJ) obstruction and the other with gross hydronephrosis but an atretic ipsilateral ureter, underwent trans-pyeloureteric anastomosis to relieve the obstruction. RESULTS: Both patients demonstrated satisfactory drainage of the upper tracts on postoperative imaging. CONCLUSIONS: Transureteropyeloplasty represents a novel and valid technique of urinary tract reconstruction in complex cases of PUJ obstruction.

Anastomosis, Surgical↗
PubMed2000

Cytoplasmic genomes that confer additional longevity in Drosophila melanogaster.

The mitochondrial genome has been proposed as a principal site of somatic mutation during ageing. A variation of the error catastrophe model has been proposed, in which ROS damages the mitochondrial genome, which leads to additional ROS production in a positive feed back cycle. This leads to major DNA damage, bioenergy crisis, and reduced functional capacity in old age and contributes to mortality. Therefore it might be expected that in strains in which the mitochondrial genomes vary, ROS and bioenergy crisis should covary and negatively correlate with longevity. Strains of Drosophila were produced which differed in their mitochondria by breeding maternally inherited genomes onto a common nuclear background. The donor strains included two long lived and two control strains. Those strains that had the cytoplasmic genomes from the long-lived strains were also long lived. In these strains ROS production in young flies negatively correlated with longevity supporting a role for ROS in ageing and/or the death process. Ageing Drosophila show a failure in bioenergy, but the relative strength of this phenotype does not segregate with longevity. These data do not support the error catastrophe model, but suggests that the principal outcome of ROS damage that leads to death is not bioenergy failure, and that bioenergy failure is at least partly due to non-ROS processes.

Animals↗
PubMed2000

The circadian clock in old Drosophila melanogaster.

A growing body of evidence indicates that one of the age-associated changes in the central nervous system that affect most old people is the loss of function of the circadian clock system. This loss results in impaired timing and quality of sleep, with consequent cognitive and other behavior problems. Failure of the clock contributes to the difficulties encountered with Alzheimer's disease. It also results in adverse changes in the hormonal regulation of intermediary metabolism, stress resistance and sexual function. Drosophila melanogaster is proposed as a model organism where this age-related change may be studied more readily. Circadian patterns are disrupted in Drosophila, with considerable differences between strains. In addition a fusion gene product of a key gene involved in the clock (per), and Green Fluorescent Protein, shows a 50% fall with age.

Aging↗
PubMed1999

Immigration and tuberculosis among children on the United States-Mexico border, County of San Diego, California.

OBJECTIVE: To identify factors contributing to a 400% increase in tuberculosis among children in San Diego County, California, from 1985 to 1993. DESIGN: Review of medical records of reported cases in 1989, 1991, and 1993 and their source case. RESULTS: Of 192 children with tuberculosis, the largest increase was observed in children younger than 5 years old, of whom 77.4% were born in the United States, 67.8% had a foreign-born parent, 73.1% came from a non-English-speaking household, and 46.2% were known to visit Mexico. Of 28 source cases, 82.1% were born outside the United States, primarily in Mexico (67.9%). Resistance to at least one first-line antituberculous drug was identified in 27.5% of isolates from children and in 33.3% of isolates from source cases. CONCLUSIONS: The increase in tuberculosis and high level of drug-resistance among children born in the United States may be attributed to transmission outside of the United States or within the United States from household contacts born in countries in which tuberculosis is highly endemic.

Adolescent↗
PubMed1999

Removal of ear wax.

Explore the source record for details and available documents.

Carbamide Peroxide↗
PubMed1985

Nephrogenic adenoma.

Nephrogenic adenoma is an uncommon, benign, apparently metaplastic response of urothelium to chronic infection or irritation. Endoscopically, these lesions easily can be mistaken for malignant tumors, and their scarcity only heightens the possibility of this error. A case report of nephrogenic adenoma accompanied by endoscopic photographs is presented to improve awareness and avoid inappropriate therapy.

Adenoma↗