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Biomedical subjects

J J Roth

Publications and source records attributed to J J Roth.

At least 19 recordsLinked to original sources
PubMed1992

A single ovary of Anolis carolinensis responds more to exogenous gonadotropin if the contralateral ovary is absent.

The lizard Anolis carolinensis exhibits asymmetric ovarian growth. At any given time, the larger ovary (LO) contains a larger follicle than does the smaller ovary (SO). Physiologically hypophysectomized females with quiescent ovaries were treated with gonadotropin (ovine FSH) or saline vehicle after either surgical removal of the LO or sham operation. The smaller ovaries of initial control, sham-operated, and hemiovariectomized (HO) females were similar in weight and follicular size. Therefore, endogenous gonadotropin secretion remained at subthreshold levels during the experiment and after HO. FSH significantly stimulated ovarian follicular growth in both sham-operated and HO females. However, the response of the SO of HO females to FSH was significantly greater than that in sham-operated females. These results demonstrate a greater sensitivity of the SO to FSH if the LO is absent.

Animals↗
PubMed1980

Nonpineal melatonin in the alligator (Alligator mississippiensis).

All living and most fossil representatives of the reptilian subclass Archosauria lack pineal bodies. Arrhythmic, low-level, nonpineal melatonin is present, however, in the blood of Alligator mississippiensis. Although pineal bodies have been implicated in circadian phenomena, these results suggest that arrhytmic melatonin in alligators may not be involved incircadian events and indicate that the pineal is not the only source of the hormone melatonin. The evolutionary loss of the pineal in Archosauria occurred during the Mesozoic, and era noted for its seasonal stability. Arrhythmic melatonin titers inalligators and pineal loss in alligators and other archosaurs may be related to Mesozoic seasonal stability.

Alligators and Crocodiles↗
PubMed1980

Clinical evaluation of gingival recession treated by coronally repositioned flap technique.

Thirty-four areas of gingival recession in ten patients were treated by a coronally repositioned flap procedure. All but four of these areas had received a free gingiva graft previously. The postoperative evaluations of the wound healing were made at 2 weeks and at 1, 2, 4, 6 and 12 months after the final surgery. In most cases the amount of gingival recession was reduced with the average tissue gain being 1.82 mm. The gingival sulcus depth was unaffected by the procedure. Several cases showed total root coverage. Although the procedure described has many advantages, the authors feel these must be carefully weighed against the disadvantages before subjecting patients to such surgery.

Adult↗
PubMed1976

Body temperature of the lizard (Anolis carolinensis): effect of parietalectomy.

Thermal behavior of parietalectomized, sham-parietalectomized or intact lizards (Anolis carolinensis) was recorded in a test chamber containing moving photothermal gradients. Following parietalectomy, animals chose significantly higher temperatures than sham-parietalectomized or intact control animals, which chose lower and statistically identical temperatures. When pre-surgical and post-surgical means are compared within groups, the eccritic temperature was 2.10 degrees C higher following parietalectomy, 0.72 degrees C higher following sham-parietalectomy, and 0.31 degrees C higher in intact controls during the post-operative measurements. The effects of parietalectomy indicate that the parietalpineal complex may be involved in behavioral thermoregulation by precisely regulating exposure to heat sources (e.g. sunlight).

Animals↗
PubMed1976

Thymidylate synthetase activity in the Novikoff hepatoma.

The mechanism by which injected methotrexate increases thymidylate synthetase activity in the Novikoff hepatoma has been studied. Folic acid injection causes a similar increase in enzyme activity in hepatoma after 16 hr but the action of folic acid and methotrexate is not additive. The increase in activity of thymidine 5'-phosphate synthetase in the hepatoma caused by methotrexate is not affected by actinomycin D, but is inhibited 50% by puromycin and 100% by cycloheximide. High-speed supernatent fraction prepared from hepatoma of animals treated with methotrexate has, initially, one-half the specific thymidine 5'-phosphate synthetase activity of untreated controls. Upon addition of increasing amounts of tetrahydrofolate, the specific enzyme activity in the supernatant fraction from the methotrexate-treated animals rises to double that of the controls. Puromycin added to homogenates of Novikoff hepatoma consistently increases enzyme activity by approximately 20%. One hypothesis consistent with these results and results reported by others is presented.

Animals↗
PubMed1975

Mast cell histamine and ovarian follicular growth in the lizard Anolis carolinensis.

The hypothesis is proposed that histamine released from mast cells in the theca of ovarian follicles increases thecal hyperemia and vessel permeability, and thus plays a role in follicular growth in Anolis carolinensis. Mast cells are present in the stroma and theca, and the number of thecal mast cells increases as follicles grow. The levels of histamine in follicular walls varies with follicular size. Histamine causes vasodilatation of thecal vessels. Antihistamine blocks the effects of histamine and, when given alone, stimulates vasoconstriction. Antihistamine also blocks estradiol-induced growth of large follicles. These findings are consistent with the above hypothesis.

Animals↗