Choroid plexus papilloma. I. Proof of cerebrospinal fluid overproduction.

Utilizing a ventricular perfusion technique, the rate of CSF formation was determined in a 2-year-old child before and after removal of a 74 g choroid plexus papilloma from the left lateral ventricle. Preoperatively, the CSF formation rate was 1.05 +/- SD 0.01 ml/min (1,656 ml/day). Postoperatively, the CSF formation rate was reduced fivefold to 0.20 +/- SD 0.01 ml/min (288 ml/day). Whereas these data are regarded as conclusive evidence of CSF overproduction by a choroid plexus papilloma, the pathogenesis of generalized ventricular enlargement in this case was due to part to obstruction of the subarachnoid pathways.     

Sodium cholate extraction of rat liver nuclear xenobiotic-metabolizing enzymes

DNA is the purported target of several carcinogenic and mutagenic agents. Nuclear enzymes which could generate or detoxify reactive metabolites are of major concern. Several such enzymes have been identified within nuclei, but obtaining samples with enriched content or activity is difficult, time-consuming, and uses harsh isolation techniques. Extraction of rat liver nuclear suspensions with cholate-containing buffer results in solubilization of 25-30% of the protein. Linear extraction was obtained for total protein and cytochromes P-450 and b5, NADPH-cytochrome P-450 reductase, NADH-cytochrome b5 reductase, DT-diaphorase, and microsomal-like epoxide hydrolase with specific activities comparable to values reported for isolated nuclear membrane, while the yield was five to ten times greater. Detergent extracts of rat liver nuclei were employed to study the comparative response of microsomal and nuclear enzymes to chemical treatment. While the responses to acute inductive (phenobarbital and 3-methylcholanthrene) and toxic (carbon tetrachloride and dibromochloropropane) treatments were qualitatively similar, an initiation-promotion protocol (diethylnitrosamine with phenobarbital promotion) resulted in divergent responses between the enzymes in the two subcellular fractions. Detergent extracts of nuclei offer an efficient means of recovering xenobiotic-metabolizing enzymes from rat liver nuclei, and have been utilized to demonstrate a differential response of nuclear enzymes during preneoplastic development.     

Cytosolic epoxide hydrolase in human placenta

It has been shown that cytosol from human term placenta contains cytosolic epoxide hydrolase activity. This cytosolic epoxide hydrolase was enriched more than 700-fold by affinity chromatography and appears similar to the enzyme from mouse and human liver in terms of molecular mass (Mr 59,000) and antigenic reactivity.     

Fine-needle aspiration biopsy with a vacuum test tube

A simple, low-cost, automatic aspiration system that makes use of vacuum test tubes designed for the drawing of venous blood has been used for real-time ultrasound (US)-guided fine-needle aspiration biopsy of 13 cysts (breast), an abscess (liver), and five solid (breast, liver, thyroid) masses. Because it allows the operator to perform aspiration with one hand while holding the real-time US transducer with the other, and because creation of the suction is associated with no significant displacement of the needle, this approach has allowed sampling of lesions less than 1 cm in diameter. No complications have occurred.     

Normal rate of cerebrospinal fluid formation five years after bilateral choroid plexectomy. Case report.

A ventricular perfusion technique was used to determine the rate of cerebrospinal fluid (CSF) formation in a 5-year-old child who had undergone bilateral choroid plexectomy for communicating hydrocephalus during infancy. At the time of the study, the patient had a failed ventriculoperitoneal shunt and was suffering from progressive ventriculomegaly. The calculated rate of CSF formation, 0.35 ml/min +/- 0.02 standard deviation, was within normal limits.     

Intraluminal calcifications in the small bowel of newborn infants with total colonic aganglionosis

Intraluminal calcifications were found in the small bowel of 4 newborns with total colonic aganglionosis. Abdominal radiography demonstrated circular aggregations of small punctate calcific densities in the right lower quadrant and evidence of bowel obstruction. There was a microcolon in each case. The calcifications, which resemble those seen in small intestinal atresia and stenosis, are probably related to fetal intestinal stasis, and may be differentiated from those due to meconium peritonitis.     

Use of carboxylesterase activity to remove pyrethroid-associated toxicity to Ceriodaphnia dubia and Hyalella azteca in toxicity identification evaluations

Increases in the use and application of pyrethroid insecticides have resulted in concern regarding potential effects on aquatic ecosystems. Methods for the detection of pyrethroids in receiving waters are required to monitor environmental levels of these insecticides. One method employed for the identification of causes of toxicity in aquatic samples is the toxicity identification evaluation (TIE); however, current TIE protocols do not include specific methods for pyrethroid detection. Recent work identified carboxylesterase treatment as a useful method for removing/detecting pyrethroid-associated toxicity. The present study has extended this earlier work and examined the ability of carboxylesterase activity to remove permethrin- and bifenthrin-associated toxicity to Ceriodaphnia dubia and Hyalella azteca in a variety of matrices, including laboratory water, Sacramento River (CA, USA) water, and Salinas River (CA, USA) interstitial water. Esterase activity successfully removed 1,000 ng/L of permethrin-associated toxicity and 600 ng/L of bifenthrin-associated toxicity to C. dubia in Sacramento River water. In interstitial water, 200 ng/L of permethrin-associated toxicity and 60 ng/L of bifenthrin-associated toxicity to H. azteca were removed. The selectivity of the method was validated using heat-inactivated enzyme and bovine serum albumin, demonstrating that catalytically active esterase is required. Further studies showed that the enzyme is not significantly inhibited by metals. Matrix effects on esterase activity were examined with municipal effluent and seawater in addition to the matrices discussed above. Results confirmed that the esterase retains catalytic function in a diverse array of matrices, suggesting that this technique can be adapted to a variety of aquatic samples. These data demonstrate the utility of carboxylesterase treatment as a viable step to detect the presence of pyrethroids in receiving waters.