Search PubMed⌕ Search

Biomedical subjects

J M Mason

Publications and source records attributed to J M Mason.

137 records · Page 8Linked to original sources
PubMed1975

Cancer-related aspects of regeneration research: a review.

Tissue regeneration is simply the replacement of lost cells of a tissue by those remaining. Epimorphic regeneration involves dedifferentiation of many tissues and their organization into a blastema which eventually differentiates into the missing part, usually an appendage. A detailed comparison of the cell membrane changes occurring in epimorphic regeneration, tissue regeneration and cancer can contribute to greater understanding of the differences between normal and tumor cells. Further, there is evidence that epimorphic regeneration fields may in some instances suppress tuomr induction and control existing tumors. This influence may be mediated by bioelectric fields, which are ubiquitous in nature and appear to control many cellular events. Disruption of these bioelectric fields suppresses epimorphic regeneration and may lead to cancer in mammals, while applied electric fields alter regenerative events and cause tumor regression.

Amphibians↗
PubMed1974

Protein patterns during regeneration and wound healing in the adult newt: a comparative study using gel electrophoresis.

Gel electrophoresis was performed on tissue extracts made from regenerating tails, limbs and deep razor blade wounds to the back of adult newts. In general, 3 types of changes appeared in posttrauma gels: decrease in density of some bands, increase in others, and "new" bands. Patterns were very similar in limb and tail regeneration suggesting that the two processes do not differ significantly with regard to alterations in the major soluble proteins. The patterns further indicated that certain wound-healing events also occur in regeneration. Some of these events are prolonged in the latter, while others are long-lasting in both. The results also suggest the existence of a regeneration-specific protein.

Amputation, Surgical↗
PubMed1972

The effects of vasopressin on the diuretic response to left atrial distension.

1. The diuretic response to left atrial distension was studied during infusion of saline or during infusion of vasopressin at four different dose rates.2. During infusion of saline left atrial distension caused an increase in free water clearance and an increase in osmolal clearance.3. During infusion of vasopressin at a rate of 0.025 m-u./kg.min and 0.1 m-u./kg.min there was no statistically significant increase in free water clearance during left atrial distension but there were variations in free water clearance in individual experiments.4. During infusion of vasopressin in doses of 0.4 m-u./kg.min and 1.0 m-u./kg.min changes in free water clearance were dependent upon changes in osmolal clearance indicating that these doses of vasopressin provided a maximum antidiuretic effect.5. Infusion of vasopressin had no effect on the increase in osmolal clearance which occurred in response to left atrial distension.6. The results allow the view that a part of the diuretic response to left atrial distension could depend upon a decrease in the concentration of antidiuretic hormone in the circulating blood.

Animals↗
PubMedDate not supplied

Current status of aneuploidy testing in Drosophila.

Based on the literature on file at EMIC, 181 papers contained material on aneuploidy testing. Initial screening rejected papers providing no data, no negative control and/or poorly designed genetic schemes; 67 papers representing tests of 76 compounds were reported on. Statistical classifications were established as follows: (+)=a statistically significant difference at the 5% level between the treated and control frequencies; (-)=no significant difference at the 5% level when the number of offspring tested was sufficient to have identified an increase of 0.2% over the control with a power of 75%; I=inconclusive= (a) no significant difference at the 5% level but the number of offspring tested was below that necessary to detect an increase of 0.2% with a power of 75%; (b) the nature of apparent complete loss is undetermined; or (c) the nature of the germ cells sampled is not determined. Of the 76 compounds analyzed, calls were made on 34 compounds. 17/34 compounds were positive for chromosome gain (11/34 for chromosome gain and chromosome loss, 6/34 for chromosome gain only). 17/34 compounds were negative for chromosome gain (11/34 for chromosome gain and chromosome loss and 6 for chromosome gain only). Are any fo the compounds found to induce aneuploidy specific for aneuploid induction? 7 or the compounds positive for chromosome gain were positive in one or more tests assaying for other genetic endpoints, and no reliable data exists regarding results in other tests for the remaining 10 compounds; accordingly, the answer to the question awaits further work.

Aneuploidy↗
PubMedDate not supplied

Effectiveness and safety of fexofenadine, a new nonsedating H1-receptor antagonist, in the treatment of fall allergies.

Fexofenadine HCl is a new, nonsedating H1-receptor antagonist approved for treatment of seasonal allergic rhinitis (SAR). In a double-blind, randomized, placebo-controlled, multicenter trial, 588 patients with fall SAR rated the severity of their symptoms using a scoring system at a screening visit and during a 3-day placebo lead-in period. Patients who did not respond to placebo and met symptom severity criteria were randomized to receive placebo or fexofenadine HCl at 40, 60, or 120 mg bid at 7:00 a.m. and 7:00 p.m. for 14 days. Patients continued to rate the severity of their symptoms immediately before receiving each dose (at trough). A total of 545 patients were included in an intent-to-treat analysis. The change from baseline in the primary efficacy variable (average daily 7:00 p.m. reflective symptom scores) was significantly greater in patients receiving all dosages of fexofenadine HCl than placebo (p < 0.01). All active dosages produced significant decreases (p < 0.05) in secondary end points: 7:00 a.m. reflective symptom scoring; 7:00 a.m. and 7:00 p.m. scoring 1-hour before dose; and bedtime scoring 1-3 hours after the 7:00 p.m. dose. All dosages of fexofenadine HCl were well tolerated, and no effect on QTc was observed. In conclusion, fexofenadine HCl is safe and effective in the treatment of fall SAR, with 60 mg bid being the optimal therapeutic dosage.

Administration, Oral↗