Retention of chromosome 3 in extrapulmonary small cell cancer shown by molecular and cytogenetic studies

In small cell lung carcinoma, one of the short arms of chromosome 3 is typically lost. To investigate chromosome 3 in extrapulmonary small cell carcinoma, we used DNA probes that detect restriction-fragment-length polymorphisms at loci on 3p. These probes were used to study DNA extracted from tumors and normal tissues and/or tumor cell lines from five patients with extrapulmonary small cell cancer. Tumor DNA from four of the five patients with extrapulmonary small cell cancer retained heterozygosity at loci on 3p. Cytogenetic studies of the tumor cell lines established from these four patients showed retention of both short arms of chromosome 3. We conclude that the loss of genetic material from 3p observed in small cell lung cancer is not typical in extrapulmonary small cell cancer.     

Studies on the alkaloidal components of the fruits ofLycium chinense

N₉-Formylharman, 1-carbomethoxy-β-carboline and perlolyrine with an unidentified alkaloid (C₁₀H₁₃NO₂, M⁺ 179.094) have been isolated from the fruits ofLycium chinense Miller (Solanaceae) and characterized on the basis of chemical and physical evidence.     

Differential inhibition produced by peripheral conditioning stimulation on noxious mechanical and thermal responses of different classes of spinal neurons in the cat

The effect of conditioning stimulation of a peripheral nerve on responses of spinal neurons (dorsal horn cells and motoneurons) was studied in 16 decerebrate-spinal cats. The activity of dorsal horn cells was recorded with a microelectrode at the lumbosacral spinal cord and the single-unit activity of motoneurons was recorded from a filament of ventral rootlet divided from either the L7 or S1 ventral root. The responses of spinal neurons were evoked by noxious and innocuous mechanical stimuli and by noxious thermal stimuli applied to the receptive fields. The peripheral conditioning stimulation was applied to the tibial nerve with repetitive electrical pulses (2 Hz) at an intensity either suprathreshold for A delta or C fibers for 5 min. Applying conditioning stimulation to a peripheral nerve produced a powerful inhibition of the responses elicited by noxious stimuli, suggesting this inhibition is an antinociceptive effect. The inhibition produced by peripheral conditioning stimulation was differentially greater on the responses to noxious than to innocuous stimuli. Based on the results obtained from conditioning stimulation with graded strengths, afferent inputs from both myelinated and unmyelinated fibers seem to contribute to the production of the antinociceptive effect. The magnitude of the antinociceptive effect is bigger for the responses to noxious thermal than to mechanical stimuli. Furthermore, the reflex activity recorded in motor axons seemed to be more sensitive than in dorsal horn cells to the antinociceptive effect.     

Optimum sample size determination in stratified case-control studies with cost considerations.

We investigate sample size determination for Cochran's test for stratified case-control studies when samples of cases and controls are allocated to maximize the asymptotic efficiency of Cochran's test subject to fixed total cost with cost per control varying by strata. We consider two situations typical of strata-matched case-control studies: when one samples both cases and controls and when cases are given and one samples controls. In each situation we develop and study an asymptotic method for finding the sample size required for a specific power under the optimum allocation proposed by Nam and Fears. Also, for the second situation, we investigate an asymptotic method for determining the common ratio, k, in one-to-k strata-matched case-control studies without cost consideration for a given power. When cases are given, neither the optimum nor the standard control sample sizes appear in a closed form; we present numerical methods for calculating these sample sizes and illustrate them with examples. We find the reduction in total cost obtained under the optimum allocation compared to standard allocation more pronounced as the differences in stratum-specific costs of sampling controls increase.     

Rudimentary Polydactyly

A case of rudimentary polydactyly on the radial aspect of the thumb of a 4-year-old male was examined. Histologic examination revealed hyperkeratosis and acanthosis in the epidermis and large numbers of nerve bundles in the dermis. With immunoperoxidase staining for S-100 protein, the nerve corpuscles were positively stained. We think that rudimentary polydactyly is a kind of congenital traumatic neuroma and that the possible cause may be intrauterine amputation.     

The role of iron in reactive oxygen species generation from diesel exhaust particles.

Diesel exhaust particles (DEP) are known to produce reactive oxygen species (ROS), which induce oxidative stress and inflammation in the lung and respiratory tract. DEP are composed of polycyclic aromatic hydrocarbons (PAH) and their derivatives, redox active semi-quinones, and trace amounts of heavy metals. ROS production was measured by thiobarbituric acid-reactive substances of deoxyribose (TBARS) formation from DEP samples obtained from Korea (DEP-KO), and the Standard Reference Material (SRM) 2975 to explore the role of transition metals. Both DEP-KO and SRM2975 had similar amounts of transition metals, whereas DEP-KO contained more iron, but less copper and zinc, than SRM2975. The water-soluble fraction from SRM2975, but not that from DEP-KO, had a broad absorption in the visible region, but not from DEP-KO, obscuring an accurate absorption measurement of TBARS. Fluorescence measurements of TBARS generation in a water-soluble extract showed that SRM2975 produces more TBARS, but the addition of hydrogen peroxide (H2O2) generated more TBARS in DEP-KO than in SRM2975, consistent with the higher amounts of iron in DEP-KO. The incubation of DEP with iron chelators inhibited the production of TBARS. Finally, a novel use of the fluorogenic spin trap probe, proxyl fluorescamine, enabled the detection of the ROS production from both DEP-KO and SRM2975. Our findings suggested that careful consideration is needed to measure TBARS production in DEP, and that iron in DEP seems to be more important than other transition metals in H2O2-induced ROS generation.