Collagenase: localization in polymorphonuclear leukocyte granules in the rabbit.

Polymorphonuclear leukocyte granules were submitted to zonal fractionation through a discontinuous sucrose gradient. Azurophilic and specific granules were enzymatically characterized by peroxidase and alkaline phosphatase activity, respectively. The enzymes formed modal distributions like those reported by others. Collagenase activity was consistently associated with the specific granules containing alkaline phosphatase.

Hypothalamic monoaminergic mechanisms of aspirin-induced analgesia in monkeys.

Microinjection of sodium acetylsalicylate (aspirin, 0.2-0.6 mg) into the preoptic anterior hypothalamic area, but not the dorsal raphe region or the periaqueductal central gray matter, produced a dose-related analgesia in conscious monkeys. The analgesia induced by intrahypothalamic administration of aspirin was antagonized by pretreatment of monkeys with either a serotoninergic receptor blocker (cyproheptadine) or two catecholaminergic receptor blockers (haloperidol and yohimbine). These suggest the existence of a monoaminergic pain-inhibitory mechanism in the preoptic anterior hypothalamic area activated by aspirin.

The inhibitory effect of oral administration of garlic on experimental carcinogenesis in hamster buccal pouches by DMBA painting.

The inhibitory effect of oral administration of garlic on experimental carcinogenesis in buccal pouches induced by painting 9,10-dimethyl-1,2-benz(a)anthracene (DMBA) was studied on 40 golden Syrian hamsters. The animals were grouped at random into four experimental groups (oral administration of garlic, NTP, BP or mineral oil followed by DMBA painting on buccal pouches), three chemical control groups (oral administration of garlic, NTP or BP without DMBA painting) and a DMBA control group (only painted DMBA on buccal pouches). Starting from the fourth week after DMBA painting, the pouch mucosae were examined biweekly for its tumor formation and blood vessel architecture. Animals were sacrificed 25 weeks after DMBA application. Tumors and pouch mucosae were dissected to examine tumor nature and biochemical reactions of DNA synthesis and GGTase activity. The inhibitory efficacy of garlic, BP and NTP were evaluated according to the results of these examinations. Garlic was found to have a higher inhibitory efficacy than BP and NTP through the probable mechanism of competitive binding with nuclear DNA and diminishing the opportunity of DMBA to initiate carcinogenesis. Other factors related to cancer inhibition included insufficient local blood flow, low GGTase activity and lesser DNA synthesis. The inhibitory effect of fractions of garlic on experimental carcinogenesis should be a reasonable and necessary continuation in future studies of the series of cancer prevention by garlic.

Inhibition of experimental carcinogenesis by painting with garlic extract.

The inhibitory effect of topical garlic extract on 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in Syrian hamsters was studied to define the local anticarcinogenicity of garlic. Two other chemicals, benzo[a]pyrene (BP) and 5-nitroso-2,4,6-triaminopyrimidine (NTP), were also testing materials. All chemicals were applied topically to the cheek pouches of hamsters. The tumorigenesis and architecture of blood vessels on pouch mucosa were examined periodically. The amount of DNA synthesis and gamma-glutamyl transpeptidase activity of the pouch mucosa was detected when the animals were killed. The anticarcinogenicity of garlic and other chemicals was determined by comparing the data obtained from all the examinations with each other and with those shown in the control animals. The apparent local inhibitory effect of garlic on DMBA-induced carcinogenesis was demonstrated, which was even stronger than those of BP and NTP. It suggests that garlic could be developed as a potential chemopreventive agent for oral cancer. This study also disclosed that the examination parameters used were reliable and reproducible. Therefore, they might be utilized for screening the anticarcinogenicity of materials or for early diagnosis of carcinogenesis. The animal model could also be adopted appropriately in evaluating the inhibitory effect of other materials on experimental carcinogenesis because of its comparability.

Possible role of central serotoninergic neurons in the development of dental pain and aspirin-induced analgesia in the monkey.

The effects of aspirin or 5-hydroxytryptamine (5-HT)-related drugs on the dental pain induced by electrical stimulation of tooth pulp afferent fibers were assessed in conscious monkeys. The electrical current required for producing jaw opening is referred to as the pain threshold. Both systemic (25 to 75 mg/kg, i.p.) or central (0.5 to 1.5 mg, third cerebral ventricle) administration of aspirin produced analgesia in monkeys. In addition, activation of central 5-HT receptors with central injection of either 5-HT or its precursor, 5-hydroxytryptophan, also produced analgesia. On the other hand, inhibition of central 5-HT receptors with central administration of either cyproheptadine (a blocking agent of 5-HT receptors), p-chlorophenylalanine (PCPA, an inhibitor of 5-HT synthesis) or 5,7-dihydroxytryptamine (5,7-DHT, a depletor of central 5-HT nerve fibers) produced an enhancement in pain sensitivity (or a decrease in pain threshold). Furthermore, the analgesia induced by aspirin was antagonized by pretreatment of monkeys with either cyproheptadine, PCPA, or 5,7-DHT. The results indicate that increases in the activity of central 5-HT neurons are associated with reduced dental pain and enhanced aspirin-induced analgesia, whereas decreases in the activity of those neurons correlate with dental hyperalgesia and diminished aspirin-induced analgesia in monkeys.

Desmoplastic amelanotic melanoma of palate: a case report with immunohistochemistry and electron microscopic studies.

A 24 year-old male with painful swelling over the right side of his palate for about two weeks was presented. An incisional biopsy was performed. In a routine hematoxylin and eosin examination by light microscopy, spindle and epithelioid cells with a bizarre appearance were discernible in the submucosal area. A pagetoid pattern was found in areas of the epithelium. Since this is not a remarkable finding, further examinations, such as the Trichrome-Masson and silver stain, immunohistochemistry using cytokeratin, vimentin, S-100, leukocyte common antigen, factor VIII, and alpha-1-antichymotrypsin detection kits, and electron microscopy were all carried out. According to the histological pattern of cells and the positive findings from the special stains, immunohistochemistry, and electron microscopy, a diagnosis of desmoplastic amelanotic melanoma was made. This variant of melanoma is a rare disorder with unremarkable, non-specific clinical manifestations in the oral cavity, which makes the diagnosis of this disease more difficult. We, therefore, report one case of this disease. Owing to the fact that diagnosis of this variant was mainly based on the positive findings of vimentin and S-100 in the immunohistochemistry examination and intracellular premelanosome detected by electron microscopy, immunodiagnosis and electron microscopy seem to be essential for differential diagnosis.