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Biomedical subjects

W Brock

Publications and source records attributed to W Brock.

9 recordsLinked to original sources
PubMed1989

Persistent cloaca and phallic urethra.

During the last 8 years 54 children with a persistent cloaca have been treated by one of us (A. P.). The most common associated anomalies involved the urinary tract, with renal agenesis, renal dysplasia, vesicoureteral reflux and megaureter encountered most frequently. Four patients demonstrated the rare entity of an opening at the tip of a pseudophallus and 2 also had an accessory urethra in association with the cloacal malformation. These children exhibited some form of masculinization of the external genitalia with the accessory urethra or cloacal channel assuming a phallic position in an enlarged clitoris. No adrenal, metabolic or chromosomal abnormalities were detected and virilization was limited to the genitalia. These cases illustrate the greater predilection of these patients to more complex congenital malformations than patients with an isolated cloaca. The posterior sagittal approach has been used effectively for repair of these congenital malformations.

Abnormalities, Multiple↗
PubMed1987

Comparison between clinical response and in vitro drug sensitivity of primary human tumors in the adhesive tumor cell culture system.

The newly described adhesive tumor cell culture system (ATCCS) offers a distinct advantage over other assays in that it has a high plating efficiency requiring low cell inoculum, it affords workable assays in approximately 70% of specimens from the heterogenous tumor types, and it has the ability to assay up to nine drugs at four different concentrations. Clinical correlations based on the ATCCS were obtained in 65 patients undergoing 71 clinical trials. Patients with melanoma, lung cancer, and sarcoma dominated the group. The most active in vitro drug was correlated per clinical trial. Thirteen of 17 (76%) sensitive in vitro predictions and 51 of 54 (94%) resistant in vitro predictions were accurate. The assay in this study had a sensitivity of 81% and specificity of 93%. These preliminary results are encouraging and warrant prospective trials to establish the true value of this assay to patients.

Adolescent↗
PubMed1985

Predicting radiocurability.

Several predictors of tumor radiocurability are already integrated into clinical practice, e.g., tumor size, gross morphologic features (i.e., infiltrative or exophytic), histologic type, and grade. These are relatively imprecise, however, and none is specific. The aim of research into predictive assays is not only to refine the discrimination of existing predictors but also to suggest specific experimental approaches for overcoming tumor radioresistance in individual patients. Two broad categories of predictive assays can be defined: direct and indirect measurements of tumor cell survival and/or repair capability following irradiation and measurement of cellular and extracellular parameters affecting radiosensitivity. Examples from ongoing research at the University of Texas M. D. Anderson Hospital using one technique from each category (the micronucleus assay and flow cytometric analysis of tumor cell proliferation kinetics and ploidy) are used to illustrate potential methods of selecting patients for fast neutron radiotherapy.

Animals↗
PubMed1984

Radical removal of lipomas of the conus and cauda equina with laser microneurosurgery.

Ten patients with ages ranging from 4 weeks to 21 years presented with a subcutaneous lumbosacral mass noted at birth. After spinal high resolution ultrasonography or computed tomography to determine the extent of neural involvement and the length of the tumor mass in the spinal canal, the patients underwent operation. Rectal electromyographic continuous monitoring was used in all for assessment of the S-2 and S-3 function during dissection. Carbon dioxide laser microneurosurgery was used in all operations. Radiating energy was used for the subcutaneous mass removal (40 to 60 W), the intracanalicular dissection (1 to 5 W), and the intraconus dissection (1 to 3 W). A radical removal was obtained in all. Postoperative cerebrospinal fluid fistula occurred in 1 patient and was successfully treated. Wound dehiscence that healed with secondary closure occurred in 2 patients. Would infection that required treatment with systemic antibiotics and topical therapy occurred in 1 patient. Paraplegia occurred in 1 patient. This was the single very significant complication of this series. It was thought to have occurred because of the polymer used to seal the tenuous dura mater at the time of closure. We conclude that, with carbon dioxide laser microneurosurgery, the lipomatous tumors can be removed safely from the neural structures of the conus and cauda.

Adolescent↗
PubMedDate not supplied

Determination of serum acid and alkaline phosphatase using 4-methylumbelliferyl phosphate.

The present report compares the performance of several colorimetric substrates presently employed in clinical laboratories for the determination of serum acid and alkaline phosphatase with that of the fluorogenic phosphatase reagent 4-methylumbelliferyl phosphate. Acid and alkaline phosphatase assays were performed on reference hospital populations in Nigeria and the United States. The results of both acid and alkaline phosphatase determinations indicate that the coefficient of variation is smaller for the fluorometric assay than for the colorimetric methods that employ either phenyl phosphate or p-nitrophenyl phosphate as the substrate. Furthermore, serum acid phosphatase determinations using 4-methylumbelliferyl phosphate identified increased serum enzyme levels in 6/6 cases of prostatic carcinoma and 9/9 cases of Gaucher's disease. The occurrence of elevated serum alkaline phosphatase levels in 24/24 cases involving liver and bone disease was also confirmed by the fluorometric alkaline phosphatase assay. In addition, sera from eight patients with the connective tissue disease, osteogenesis imperfecta, were found to contain normal levels of acid and alkaline phosphatase by the fluorometric assays. From these results it appears that the sensitive and rapid fluorometric assay procedures can be readily employed in the clinical pathology laboratory for the determination of serum acid and alkaline phosphatase levels.

Acid Phosphatase↗