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Biomedical subjects

R Talbot-Wright

Publications and source records attributed to R Talbot-Wright.

At least 19 recordsLinked to original sources

Loss of heterozygosity in renal and hepatic epithelial cystic cells from ADPKD1 patients.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the commonest genetic diseases in man, affecting 1:1000 individuals in the Caucasian population. It is caused by mutations in the PKD1 or PKD2 genes. Recently, controversial data regarding the mutational mechanism underlying cyst initiation have been reported: genetic analyses have shown that second somatic mutations may lead to cyst formation (detected as microsatellite loss of heterozygosity, LOH, and point mutations), but immunohistochemical studies show strong immunoreactivity for polycystin in some cysts. In order to further characterise this matter we have analysed 211 cysts from seven different patients for LOH, we have detected a 13.3% LOH for PKD1. This loss was specific to PKD1 as no LOH was detected when other chromosomal regions were studied. Whenever linkage analysis has been possible, it has been proved that the lost allele corresponded to the wild-type. Our data supports previous results in the two-hit theory for ADPKD due to the large number of cysts studied. ADPKD would occur through a recessive cellular mechanism. The probability of cyst development would depend on the probability of mutation in the second allele. The different phenotypical expression of the same mutation reported in ADPKD could be due to the different tendency of inactivation in the second allele in each individual.

Cells, Cultured↗

Urodynamic evaluation in simultaneous insulin-dependent diabetes mellitus and end stage renal disease.

PURPOSE: We evaluated the urodynamic changes produced by insulin-dependent diabetes mellitus with end stage renal disease. MATERIALS AND METHODS: A urodynamic evaluation was performed on 51 young patients (mean age plus or minus standard deviation 35 +/- 6 years) with long-term diabetes mellitus (average 21 +/- 6 years) and end stage renal disease (86% on dialysis). RESULTS: The urodynamic study was abnormal in 84% of the patients. The bladder was hypersensitive in 39% and hyposensitive in 30% of the cases, and maximum vesical capacity was greater than 600 ml. in 33%. An acontractile detrusor was noted in 6% of the patients, while 4% had detrusor hyperreflexia and 35% had bladder outlet obstruction. CONCLUSIONS: A high frequency of vesical alterations was observed, which were modified by association of progressive vesical dysfunction and diabetes mellitus. In diabetes mellitus dialysis protects against detrusor hypocontractility but predisposes the patients to have bladder obstruction.

Adult↗

[Is there an age limit for cadaveric kidney donors currently?].

OBJECTIVES: The insufficient number of kidney transplants has gradually raised the age limit to the cadaver kidney donor. The use of grafts harvested from older donors has been debated due to the existing structural and functional changes that might influence renal function and long-term graft survival. The foregoing aspects are discussed herein. METHODS: The anatomical, histological and functional changes in the kidney associated with ageing are analyzed. The clinical experience with renal grafts from older donors before and after cyclosporine became available are reviewed. The ethical issues on whether grafts from very old donors should be used and who should receive these grafts are discussed. RESULTS: The use of grafts from donors over 60 years old had no significant short and medium term differences in comparison with younger donors in terms of graft survival, although a higher incidence of acute tubular necrosis and poor renal function have been observed. There are no conclusive studies on the long-term effects on graft survival when kidneys from donors aged over 65 are utilized. In our experience, the results achieved with grafts from donors over 70 has been unsatisfactory. The guidelines utilized in the selection of grafts derived from older donors are presented. CONCLUSIONS: Grafts from donors aged 60 to 70 may be utilized in renal transplantation following precise selection criteria. Graft survival has been satisfactory, although a higher incidence of acute tubular necrosis and higher creatinine levels have been observed. We do not advocate the use of grafts from donors over 70, except in very exceptional cases. Long-term multicenter studies on grafts from very old donors and trials using alternative immunosuppressor modalities that might permit optimal use of these grafts are warranted.

Age Factors↗

[Congenital urethral diverticulum].

Presentation of two cases of congenital diverticula of the bulbar urethra. The objective of this paper is to discuss the etiopathogenic theories, sings and symptoms, current diagnostic methods and therapeutic indications, and to conclude that this type of diverticula do not present a florid symptomatology, endoscopy being the best diagnostic and therapeutic method. Finally, a review of the literature is made based on two clinical cases.

Adult↗

[Beneficial effect of oxygen-free radical blockers in experimental kidney transplantation in rats].

UNLABELLED: The clinical potential of free radical (OFR) ablative therapy is dependent upon the proportion of the total injury caused by the reperfusion mechanism compared with the proportion resulting from ischemic injury itself. Prostaglandin cascade can both activate and be activated by OFR. AIM: to investigate the influence of different periods of cold ischemis in renal tissue (cortex and medulla) -regarding superoxide dismutase (S.O.D.) activity, the amount of erythrocyte trapping and prostaglandin synthesis. Also, to evaluate the effect of exogenous S.O.D. in the prevention of reperfusion injury. MATERIAL AND METHODS: 48 Lewis male rats (200-250 g) received renal isografts (RTx) preserved in Collins solution at 4 C for different periods: control group (8) non operated; group I (8) immediate RTx; group II (8) 12 hrs; group III (8) 18 hrs; group IV (8) 12 hrs+S.O.D. (13 mg/kg e.v.); group V (8) 18 hrs+S.O.D. (13 mg/kg e.v.). Before reperfusion all recipients received 1 ml of 51-Cr labelled erythrocytes. After 15 min. reperfusion grafts were removed and samples (cortex and medulla) obtained for measuring trapping of erythrocytes. S.O.D. activity and prostaglandins (PGe2, TxB2, 6-Keto-PGF1). RESULTS: A strong correlation was found between the duration of cold ischemia and the amount of trapping both in cortex and in medulla. S.O.D. administration induced a significant drop of trapping. In non-operated rats S.O.D. activity in cortex was two fold medulla content. However, after reperfusion, a significant decrease in cortex was found in all groups. S.O.D. administration raised S.O.D. activity in cortex similar to control values.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗

Vesical tumors in patients under 25 years of age.

Behavior of transitional cell carcinoma of the bladder during the third decade of life remains a controversial subject. During the period 1980-1988, we treated 7 patients (4 male and 3 female), 25 years of age or less (mean age 19.3, range 14-25), with transitional cell carcinoma of the bladder. Until now, all patients are alive and without disease during 12-50 months after surgery. In 6 of the 7 patients, endoscopic resection was the choice treatment for superficial stage A/O. The seventh patient underwent a partial cystectomy for a B1 Jewet stage cell carcinoma. We conclude that transitional cell carcinoma of the bladder in patients under 25 years of age has a less aggressive biological behavior. Therefore, ultrasonographic examinations and serial urine cytology represent the elective test for follow-up. Cystoscopy would only be performed in doubtful cases.

Adolescent↗