A novel protein-free synthetic medium was developed for the culture of normal human oral keratinocytes. This medium, designated PFM-7, supports the serial cultivation of primary or secondary normal oral keratinocytes in protein-free, chemically defined conditions. Normal oral keratinocytes in PFM-7 exhibited nearly equal growth in mass culture without noticeable changes in morphology, response to added growth factors, or gene expression of growth factors and their receptors, compared to cells in Keratinocyte-SFM containing epidermal growth factor and bovine pituitary extract. Furthermore, PFM-7 supported the serial subcultivation of human squamous cell carcinoma cells and enabled both normal and malignant oral squamous cells derived from the same patient to grow under the same protein-free defined conditions. These results indicate that PFM-7 can be used for precise investigations of growth mechanisms, cell products, and gene expression associated with carcinogenesis of human epidermal cells.

Animals↗

PubMedDate not supplied

Electrophysiological studies on the cultured cells obtained from transplantable pancreatic carcinoma in Syrian golden hamsters.

A pancreatic ductal carcinoma was established as a transplantable tumor line in an inbred strain of Syrian golden hamsters. Intracellular recordings of membrane potentials and input resistance were made from cultured cells obtained from the transplanted tumors using indwelling glass microelectrode. The mean value of the resting membrane potential was -46.5 +/- 1.8 mV (S.E.) (n = 13), while the mean resting input resistance was 21.2 +/- 4.3 M omega (S.E.) (N = 13). Dibutyryl cyclic AMP (2 X 10(-3)M) caused a marked hyperpolarization of about 30 mV accompanied by a reduction of input resistance. The transplantable tumor and its cultured cell line developed in this study have demonstrated their effectiveness as a reliable experimental model for use in pancreatic cancer research.

Animals↗

PubMedDate not supplied

Permanent cell culture lines of rat erythroleukemia and growth inhibition by dexamethasone in vitro.

Four erythroleukemia cell lines were established in vitro from rats with primary leukemias induced by a set of intravenous injections of 7,8,12-trimethylbenz[a] anthracene (TMBA). These cell lines were grown in Dulbecco's medium with 20% inactivated fetal calf serum; they were characterized by specific consistent chromosome abnormalities, related to No. 2 chromosome, which were maintained in culture for more than 1 year. Addition of dexamethasone prevented the cell growth of 2 of the cell lines in this medium but failed to alter the growth rate of the other 2 cell lines. These findings are correlated with karyotype abnormalities involving chromosome No. 2.

9,10-Dimethyl-1,2-benzanthracene↗

PubMedDate not supplied

Endoscopic resection of early gastric cancer and other tumors with local injection of hypertonic saline-epinephrine.

Explore the source record for details and available documents.

Aged↗

PubMedDate not supplied

Ocular activity of topically administered anandamide in the rabbit.

Marijuana and its psychoactive constituents, cannabinoids, reduce intraocular pressure (IOP) in humans and animals. Because anandamide, a recently discovered endogenous ligand of cannabinoid receptors, reportedly shows cannabimimetic pharmacological activity, we examined its effect on the eye. Varying amounts of anandamide, in 50 microL of light mineral oil, were topically applied to a rabbit eye and changes in IOP and ocular symptoms were monitored. Anandamide (50 micrograms to 1 mg) induced a significant decrease in IOP within 1 hour after administration; maximum reduction occurred at 2 hours; and there was a return to baseline by 7 hours following administration. A noticeable hyperemia of conjunctival blood vessels was also noted 2 hours after administration. Neither mineral oil alone or with palmitylethanolamide (an analogue of anandamide) caused a significant decrease in IOP or conjunctival hyperemia. This study indicates that anandamide does produce cannabimimetic effect in rabbit eyes.

Administration, Topical↗

PubMedDate not supplied

Treatment parameters for the efficacy of transscleral cyclophotocoagulation in rabbits using a diode laser.

PURPOSE: To determine parameters for the efficacy of transscleral cyclophotocoagulation (TSCPC) using a diode laser. METHODS: We performed TSCPC on 74 pigmented rabbits with different exposure powers and varying number of applications, followed by clinical observation and histological examination up to 24 weeks. RESULTS: Based on observation of the clinical course, the most favorable parameters were 600 mW and 36 or 48 applications, which did not cause severe complications and sufficiently lowered intraocular pressure (IOP). Histological examination revealed coagulation of the epitheliums and stroma of the ciliary body at 600 mW. The stroma of the ciliary body was severely damaged at 900 mW. CONCLUSIONS: Transscleral cyclophotocoagulation at 600 mW with a larger number of applications than previously reported did not cause severe complications and effected greater and more lasting lowering of IOP than TSCPC with more intense coagulation and fewer applications.

Animals↗