Search PubMed⌕ Search

Biomedical subjects

R K Vinson

Publications and source records attributed to R K Vinson.

At least 19 recordsLinked to original sources
PubMed2001

Nucleotide excision repair gene expression in the rat conceptus during organogenesis.

DNA repair may be a determinant of the susceptibility of the conceptus to DNA damaging teratogens. The nucleotide excision repair (NER) pathway repairs a substantial amount of chemically induced DNA damage. The goals of this study were to assess the coordinate expression of NER genes in the midorganogenesis-stage rat conceptus and determine the consequences of exposure to the genotoxic teratogen, 4-hydroperoxycyclophosphamide (4-OOHCPA), on NER gene expression. Most NER genes were expressed at low levels in both yolk sac and embryo on gestational day (GD) 10, with the exception of XPD, XPE and PCNA. No significant alterations in gene expression occurred between GDs 10 and 11; in the yolk sac XPB expression increased on GD12 compared to either GD10 or 11. In the embryo, XPE expression increased between GDs 10 and 12, while hHR23B, XPB, ERCC1, and DNA polymerase epsilon expression increased on GD12 relative to both GDs 10 and 11. Contrary to gene expression data, XPB protein was found at high levels and XPD at low levels in GDs 10-12 embryos and yolk sacs. Mirroring gene expression, high levels of PCNA protein were found in both tissues; XPA protein levels were minimal in yolk sac from GDs 10-12 but increased in the embryo from moderate on GD10 to high on GD12. Therefore, NER gene expression during organogenesis was regulated in a developmental stage- and tissue-specific manner. Exposure of the conceptus to a teratogen, 4-OOHCPA, induced malformations without affecting NER transcript levels. Thus, NER gene expression in the conceptus was unresponsive to regulation by DNA alkylation.

Animals↗
PubMed2001

Expression of base excision, mismatch, and recombination repair genes in the organogenesis-stage rat conceptus and effects of exposure to a genotoxic teratogen, 4-hydroperoxycyclophosphamide.

BACKGROUND: DNA repair capability may influence the outcome of genotoxic teratogen exposure. The goals of this study were to assess the expression of base excision repair (BER), mismatch repair (MMR), and recombination repair (RCR) genes in the mid-organogenesis rat conceptus and to determine the effects on expression of exposure to the genotoxic teratogen, 4-hydroperoxycyclophosphamide (4-OOHCPA). METHODS: The expression of 17 BER, MMR, and RCR genes was examined in gestational day (GD) 10-12 rat conceptuses using the antisense RNA (aRNA) technique. Embryos were cultured with 10 microM 4-OOHCPA to examine effects on gene expression. RESULTS: Yolk sacs and embryos had similar gene expression patterns for all three DNA repair pathways from GD10-12. Transcripts for APNG, PMS1, and RAD54 were present at high concentrations in both tissues. The remainder of the genes were expressed at low levels in yolk sac, with a few not detected on GD10 and 11. In the embryo, transcripts for most genes were low on GD10 and 11; several increased by GD12. After exposure to 4-OOHCPA for 24 hr, XRCC1 and RAD57 expression decreased in yolk sac, whereas only RAD51 transcripts decreased in the embryo. By 44 hr, transcripts for all BER genes decreased in yolk sac; in the embryo, most BER, MMR, and RCR genes decreased, many below the level of detection. CONCLUSIONS: The expression of DNA repair genes in the mid-organogenesis rat conceptus is varied and subject to down-regulation by 4-OOHCPA. DNA repair gene expression may determine the consequences of genotoxicant exposure during development.

Alkylation↗
PubMed1992

Percutaneous renal biopsy of the solitary kidney: a contraindication?

We recently were presented with a patient from the nephrology service, with the request to perform open renal biopsy because of a solitary functioning kidney. We performed the open biopsy and the patient subsequently had a wound infection, leading us to question the recommendation in the literature stating that a solitary kidney is an absolute contraindication for percutaneous renal biopsy. In a review of the literature from 1951 to 1990, a total of 19,459 percutaneous renal biopsies has been reported with an overall complication rate of 2.1 to 10.8%, the majority (90%) of which did not require definitive treatment. Only 13 nephrectomies (0.06%) were required secondary to complications. The overall mortality rate was 0.08%. We reviewed 157 percutaneous renal biopsies done at this institution from 1985 to 1990 with a minor complication rate of only 5% and no major complications or loss of kidney function. The mortality rate was 0. Based on our study and a review of the literature, both showing an extremely small percentage of permanent loss of kidney function or mortality, we propose that a solitary kidney no longer be recommended as an absolute contraindication to percutaneous renal biopsy.

Biopsy↗
PubMed1986

Acute obstructive renal failure secondary to granulocytic sarcoma (chloroma).

We report an unusual case of bilateral ureteral obstruction secondary to granulocytic sarcoma of the uterine cervix. Proximal urinary diversion followed by radiation therapy to the tumor relieved the obstruction. The need for prompt diagnosis and treatment of this rare neoplasm is stressed.

Acute Kidney Injury↗
PubMed1984

Endoscopic vesicourethropexy for stress urinary incontinence. Experience at the Medical Center Hospital of Vermont.

Forty-eight women with stress urinary incontinence underwent endoscopic vesicourethropexy between December, 1978, and December, 1982, at the Medical Center Hospital of Vermont or its affiliates. Four patients were lost to follow-up within six weeks, and 44 patients were followed for four to forty-one months. The overall success rate was 79.2 per cent. Failures occurred as late as fourteen months. The major complication rate was 33.3 per cent. Major complications included suprapubic abscess formation and prolonged urinary retention for up to six months. Though an obviously effective therapy for the correction of stress urinary incontinence, our success with endoscopic vesicourethropexy is less than that generally reported. Further, the incidence and nature of postoperative complications in our series provoke a greater awareness of the potential shortcomings of this procedure.

Abscess↗
PubMed1981

Urachal leiomyosarcoma.

A case of urachal leiomyosarcoma in a twenty-eight-year-old man is presented. His treatment and a review of the literature are discussed.

Adult↗
PubMed1979

Urolithiasis from stapler anastomosis.

The simplicity of operation and versatility and speed of automatic stapling devices in the creation of ileal loops have been amply documented. Three cases of stone formation in the ileal loop, secondary to encrustation about the staples, are reported herein, and the modification to the surgical technic which would obviate this problem is presented.

Adult↗
PubMed1979

Cystometry in upright position: accurate identification of decompensated bladder.

Cystometrograms obtained in the physiologic erect position have been found to picture accurately the classic decompensated bladder in women with recurrent urinary tract infections. The standard supine cystometrogram, however, may be inaccurate or normal in females with a history of infrequent voiding and prolonged vesical overdistention.

Adolescent↗
PubMed1979

Testicular tumor in male pseudohermaphrodite with X/XY chromosomal mosaicism.

A case of testicular tumor in an intersex patient is presented. Knowledge of the potential of gonadal malignancy is important in the management of disorders of sexual differentiation. These patients, in whom the fields of oncology, embryology, endocrinology, and genetics intersect, provide a fruitful ground for clinical investigation.

Adult↗
PubMed1978

Interstitial cell tumor. Profile of hormone-producing tumor.

Interstitial cell tumor of the testis in an adult male can present with feminization and psychologic changes. The feminization and psychologic changes most likely reflect production of estrogen by the interstitial cell tumor. Removal of the tumor causes rapid return of the pituitary-testicular axis to normal, loss of feminization, and development of male psychosocial characteristics.

Adult↗
PubMed1977

Pseudoureterocele: a uroradiologic entity.

An analysis of 5 patients with an acquired dilatation of the distal ureter, simulating a simple ureterocele, is herein reported. Radiologically, pseudoureteroceles are more likely to be associated with ipsilateral upper tract obstruction and have asymmetric intravesical dilatation. The urologist should be aware of this urographic deformity, for the majority of pseudoureteroceles are related to malignancy involving or invading the bladder.

Aged↗