Comparative dermal carcinogenesis of shale and petroleum-derived distillates

Ten test materials derived from petroleum or hydrotreated shale oils were applied 3 times/week for up to 105 weeks to the shaved skin of 25 male and 25 female C3H/HeN mice per group. Mineral oil and benzo(a) pyrene (0.15%) were control materials. Clinical observations were recorded during the study. At death, histopathologic examination was conducted on skin, internal organs and any gross lesions. Exposures to some materials were ended midway in the study due to severe irritation. Chronic toxicity of all materials was limited to inflammatory and degenerative skin changes. Significant increases over control incidence of skin tumors (squamous cell carcinoma and fibrosarcoma) occurred with both petroleum and shale-derived naphtha (21%, 50%), Jet A (26%, 28%), JP-4 (26%, 50%), and crude oils (84%, 54%). Severely hydrotreated shale oil and petroleum and shale-derived diesel distillates were not considered tumorigenic. Results indicate that toxicity of comparable petroleum and shale-derived fractions was qualitatively similar and confirm earlier findings that hydrotreating reduces or eliminates carcinogenicity of raw shale oil.     

The state of DNA methylation in the promoter and exon 1 regions of the human gene for the interleukin-2 receptor {alpha} chain (IL-2R{alpha}) in various cell types

The gene for the human interleukin-2 receptor     

Parasternal mediastinal sonography: sensitivity in the detection of anterior mediastinal and subcarinal tumors

Twenty-seven patients with anterior mediastinal and subcarinal mediastinal tumors confirmed by CT and 30 control subjects were prospectively investigated by sonography performed via a parasternal approach in both decubitus positions. The sonograms and CT scans were interpreted blindly by two investigators and the results of the two procedures were compared. In the group of 30 controls, sonography via the right parasternal approach showed the anterior mediastinum in 29 (97%) and the subcarinal space in 27 (90%). Fifteen (94%) of 16 anterior mediastinal tumors and 16 (94%) of 17 subcarinal tumors were identified sonographically. These results show that parasternal sonography is a sensitive technique for the detection of tumors in the anterior mediastinal and subcarinal mediastinal spaces.     

Identification of fast spurts of pyridine nucleotide oxidation evoked by light stimulation in the isolated perfused vertebrate retina

Transitory increases of ultraviolet transmission on stimulation with light were recorded simultaneously with electroretinogram on and off effects from isolated vertebrate retina. The spectral distribution of the optical light responses coincided with that of NADH reduction. The correlation of the optical, or respiratory, responses and the electrical responses were very close within a wide range of stimulus parameters, suggesting an interpretation in terms of supply and demand of energy with a tight coupling between the two kinds of evoked activity. Prerequisite to the response behaviour was the preservation of synaptic signal transmission from first- to higher-order retinal neurons.     

Normal intracortical excitability in developmental stuttering.

Persistent developmental stuttering (PDS) shares clinical features with task-specific dystonias. In these dystonias, intracortical inhibition is abnormally weak. We therefore sought to determine intracortical inhibition and intracortical facilitation in PDS. In 18 subjects with PDS since childhood (mean age, 39.4 [SD 13.0] years) and 18 speech-fluent controls (43.6 [14.3] years), we investigated resting and active motor thresholds as well as intracortical inhibition and facilitation of the optimal representation of the abductor digiti minimi of the dominant hand using transcranial magnetic stimulation. In PDS, the resting and active motor thresholds were increased, whereas intracortical inhibition and facilitation were normal. Normal intracortical excitability makes a pathophysiological analogy between focal dystonia and PDS less likely. The enhanced motor threshold suggests reduced motor cortical neuronal membrane excitability in PDS.     

Analgesic profile of the sodium salt of pemedolac

Pemedolac Na, 1-ethyl-1,3,4,9-tetrahydro-4-(phenylmethyl)-pyrano [3,4-b] indole-1-acetic acid sodium salt, exhibited equipotent analgesic effects after oral, iv, and im administration, suggesting that it is well absorbed. In mouse writhing models, the ED₅₀ values ranged from 0.3 mg (0.81 μmol)/kg (vs. acetylcholine) to 4.3 mg (11.6 μmol)/kg (vs. paraphenylbenzoquinone [PBQ]). In the rat Randall-Selitto model, the ED₅₀ o the compound was approximately 0.001 mg (2.7 nmol)/kg, with a flat dose response curve. The peak effects lasted for 7–9 h, 10–18 h, and 5 h following oral, im, and iv injections, respectively. Intracerebroventricular (i.c.v.) injections of pemedolac Na inhibited the PBQ-induced writing in mice with an ED₅₀ of 43.5 μg (0.12 μmol)/mouse, and this effect was not antagonized by naloxone. It was inactive in the hot plate and tail flick tests, demonstrating that pemedolac Na does not act via an opiate mechanism. These results indicate that pemedolac Na is a viable parenteral and oral analgesic, typified by high analgesic potency, a rapid onset and long duration of action, and an extremely wide safety index. © Wiley-Liss, Inc.