Motor nerve conduction velocity distributions in man: results of a new computer-based collision technique

A new computer-based collision technique for direct measurement of the human motor nerve conduction velocity distribution is described. In contrast to previous collision techniques, the test muscle response is progressively cancelled to a null using an arrangement of proximal and distal stimuli which eliminates distortion of the test response caused by transient changes in nerve and muscle fibre conduction. The increased sensitivity of this new technique permits accurate measurement of the slowest 1% of alpha motor nerve fibres. We have used our modified collision technique to determine motor nerve conduction velocity distributions for the median nerve in 20 normal subjects aged between 19 and 59 (mean 35) years. 150% maximal stimulus intensities were used, with a controlled limb temperature of 35 degrees C. Group mean velocities (+/- S.D.) for the fastest (95%), mean (50%) and slowest (5% and 1%) motor fibres were 59.1 +/- 3.0, 56.9 +/- 2.9, 52.7 +/- 3.1 and 51.2 +/- 3.7 m/sec respectively. Data are also presented for the ulnar and peroneal nerves.     

Salvage immunotherapy of malignant glioma

We present the preliminary results of a phase I trial of adoptive immunotherapy for recurrent or residual malignant glioma. The protocol is based on surgical debulking followed by implantation into the tumor bed of autologous lymphocytes that have been stimulated with phytohemagglutinin-P and then cultured in vitro in the presence of interleukin 2. Fifty-five patients with a mean Karnofsky rating of 64 were treated between February 1985 and March 1987. No significant toxicity was associated with the immunotherapy. Fifty patients had a positive initial response to therapy, nine patients had early recurrence (two to four months after treatment), and 22 patients died. We comment on major differences between the protocol described and other immunotherapy protocols.     

Firearm and nonfirearm homicide among persons 15 through 19 years of age. Differences by level of urbanization, United States, 1979 through 1989.

OBJECTIVE--To examine trends (1979 through 1989) and current status in firearm and nonfirearm homicide rates by level of urbanization among persons 15 through 19 years of age. DESIGN--The Compressed Mortality File, a county-level mortality and population database maintained by the National Center for Health Statistics, Centers for Disease Control, Hyattsville, Md, and the 1980 Human Resource Profile County Codes are used to analyze age-, sex-, and race-specific firearm and nonfirearm homicide rates by urbanization level. SETTING--United States, 1979 through 1989. SUBJECTS--Black and white males and females 15 through 19 years of age whose underlying cause of death was either firearm homicide (E965.0 through E965.4 or E970) or nonfirearm homicide (E960 through E964, E965.5 through E969, or E971 through E978) in the ICD-9 (International Statistical Classification of Diseases, Injuries, and Causes of Death, Ninth Revision). MAIN OUTCOME MEASURES--Urbanization level-specific firearm and nonfirearm homicide rates. RESULTS--The 1989 firearm homicide rate in metropolitan counties was nearly five times the rate in nonmetropolitan counties (13.7 vs 2.9 deaths per 100,000 population). Firearm homicide rates were highest in core metropolitan counties, 27.7 per 100,000 population; rates were higher for black males than for any other race-sex group in each of five county urbanization strata for 1979 through 1989. Nonfirearm homicide rates are considerably lower, with smaller urban differentials; the rate in metropolitan counties was 1.4 times the rate in nonmetropolitan counties (2.6 vs 1.8 per 100,000 population). From 1979 through 1984, firearm homicide rates declined in each of the county strata. From 1984 through 1987, firearm homicide rates increased, and from 1987 through 1989 they increased rapidly, from 23% to 35% per year in the four metropolitan strata. From 1979 through 1989, nonfirearm homicide rates declined or remained stable. CONCLUSIONS--Large urbanization differentials in firearm homicide and smaller differentials in nonfirearm homicide are identified. Firearm homicide rates are highest and increasing the fastest among black teenage males in the core, fringe, and medium metropolitan strata.