Repair of severed peripheral nerves: Comparison of the “de Medinaceli” and standard microsuture methods

The return of function following transection of the rat sciatic nerve has been assessed after repair by either standard microsurgical techniques (i.e., the use of microsutures to coapt the severed ends) or the new repair technique introduced by de Medinaceli and coworkers. The regeneration after transection was compared with that following sciatic nerve crush, i.e., a lesion in which the return of function is near optimal. Return of function was monitored serially using walking track analysis (i.e., the sciatic functional index, which indicates overall functional performance), the ability to spread the toes (which indicates intrinsic function in the foot), and the determination of muscle twitch tension of the middle digit. Function in the nerve crush group returned to within the normal range by 53 days, but function in the transection and repair groups did not return to normal before the rats were perfused at 85 postoperative days. However, the function regained when nerves were repaired with the de Medinaceli technique was significantly superior to that regained after repair with microsutures. Histological examination of the repair site (at 85 days) revealed that the regenerated nerve fibers in the de Medinaceli group crossed the site of anastomosis in a relatively orderly fashion, whereas they were more randomly arranged when microsutures were used. However, there was no statistical difference between the two groups in the number of regenerated fibers present in the distal stump. The increase in function in the de Medinaceli group may therefore arise primarily from an increase in the proportion of regenerating fibers which reach appropriate targets.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pharmacokinetics of peptide T in patients with Acquired Immunodeficiency Syndrome (AIDS)

1. The pharmacokinetics of Dalal-peptide T-NH2 (peptide T) was determined during phase I clinical trials in patients with acquired immunodeficiecy disease (AIDS) and AIDS related complex (ARC). Drug levels were determined by specific RIA, and in some cases with HPLC analysis, after intraveneous (i.v.) or intranasal (i.n.), via metered sprayer, administration.

2. The plasma kinetics appeared to be bi-phasic with a first compartment half-life of 30 to 60 minutes and a second plasma clearence rate of 4 to 6 hours, observed for both routes of administration. Peptide T, in one individual was confirmed to be present at 6 hrs in plasma, determined after HPLC isolation followed by specific RIA.

3. Bioavailabilty, determined for a 2 mg test dose in six individuals was 9.3 ± 6.9 nmol/L. Peak plasma levels of 41 ± 30 nmol/L after 10 mg i.n., 2.8 ± 5.9 nmol/L after 2mg i.n., and 0.13 ± 0.07 nmol/L after 0.4 mg i.n. were observed. In two individuals tested, peptide T was detected in CSF at levels 20% of the corresponding plasma level 90 and 145 minutes post i.v. administration. Peptide T was not detected in urine. I.N. administration was well tolerated for times up to 21 months.     

Family History of Alcoholism Does Not Predict Neuropsychological Performance in Alcoholics

We examined the relationship of history of alcoholism in first-degree relatives to neuropsychological performance of alcoholics abstinent from several weeks to several years. Eighty-four men were assigned to four groups based on "strength" of family history of alcoholism. The groups were: (1) "strong history," a parent plus another first-degree relative positive; (2) "moderate," parent only positive; (3) "weak," nonparent first-degree relative only positive; and (4) "negative," no first-degree relative positive. There were no significant between-group differences in NP performance. In other analyses there were no NP differences between alcoholics classified positive or negative purely on basis of paternal alcoholism, and no differences between subjects who had multigenerational versus unigenerational versus negative familial histories of alcoholism. It is concluded that genetic loading for alcoholism does not significantly affect the NP status of abstinent alcoholic groups equated for education, drinking history, and medical risk.     

Fibula osteoseptocutaneous flap for mandible reconstruction

The fibula free flap has become an established flap for mandible reconstruction when vascularized bone is desirable. Recreating mandibular contour, providing soft tissue coverage, and restoring masticatory function are equally important in mandible reconstruction, and these can be provided by the fibula osteoseptocutaneous flap. This article is a summary of the anatomy, indications, and operative technique of the fibula osteoseptocutaneous flap accumulated from 49 consecutive mandible reconstructions. © 1994 Wiley-Liss, Inc.     

Transformation of immortal, non-tumorigenic osteoblast-like human osteosarcoma cells to the tumorigenic phenotype by nickel sulfate

Epidemiological studies have indirectly linked compounds ofchromium, nickel and arsenic to human carcinogenesis. However,there is no evidence that metal compounds can transform humancells to the tumorigenic phenotype in culture. We show herethat exposure to 36 µM NiS0₄ for 48–96 h resultsin transformation of an immortal, non-tumorigenic, osteoblast-likecell line, HOS TE85, to the tumorigenic phenotype. Continuouspassaging following treatment leads to the formation of a fewdense foci. The cells isolated and expanded from the foci aremorphologically transformed, and form anchorage-independentcolonies of the size and abundance comparable to that formedby Kirsten murine sarcoma virus transformed HOS TE85 cells.The transformed cells from tumors in nude mice, have enhancedlevels of plasminogen activators and have lost the ability toform model bone matrix on extended culture in the presence ofascorbic acid and ß-glycerophosphate. A number ofcell lines have been established from nude mouse tumors. Cytogeneticanalysis reveals 16 marker chromosomes and an aberrant chromosome16. This is the first report of the transformation of a humancell line to tumorigenic phenotype by a metal carcinogen.     

Nurses' Logs as an Evaluation Tool for School-Based Violence Prevention Programs

ABSTRACT: Programs for preventing violence among youth should be evaluated to determine if they are effective. Nurses' logs appear to be a useful tool for evaluating school-based violence prevention programs. The logs provide a record of students' visits to the school nurse that can be used to determine if a violence prevention program is associated with a reduction in fighting—and other injury-related nurse visits. This method has many strengths: it is simple and inexpensive, it does not interrupt the school routine, it permits school-level rather than student-level data collection, it provides a ready "baseline," and it allows continuous data collection. However, potential limitations do exist. For example, the method may provide insufficient information and may be affected by factors unrelated to the intervention. School officials can increase the usefulness of the logs by encouraging standardization and providing training in their use.