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E J Watson

Publications and source records attributed to E J Watson.

15 recordsLinked to original sources
PubMed2005

Insect succession and decomposition of wildlife carcasses during fall and winter in Louisiana.

Fourteen fresh animal carcasses were monitored throughout decomposition in a mixed flatwood forest in East Baton Rouge Parish, LA, from 5 October to 7 December 1999 (fall) and from 18 January to 30 March 2000 (winter). Species composition and residency patterns of necrophilous insects were documented for four animal species per seasonal experiment: one Louisiana black bear (threatened species), two white-tailed deer, two alligators, and two swine (experimental reference). Results suggested variation in species composition associated with temperature (fall versus winter conditions) and carcass type. In total, 89 species from 39 families and three classes were manually collected from the seven fall carcasses. Ninety-five species from 38 families and three classes were collected at the seven winter carcasses. Overall arthropod diversity was greatest for fall deer and winter swine carrion. Fall alligator carcasses were associated with fewer taxa than the three mammal species during both seasons. The hairy maggot blow fly, Chrysomya rufifacies (Macquart), was the dominant species of the fall study, impacting developmental rates and overall carrion community structure. The winter study was characterized by prolonged carcass decomposition and reduced insect activity due to fluctuating ambient temperatures.

Alligators and Crocodiles↗
PubMed2003

Spring succession of necrophilous insects on wildlife carcasses in Louisiana.

Seven fresh animal carcasses were monitored throughout decomposition in a mixed flatwood forest in East Baton Rouge Parish, LA from 1 April to 1 July 1999. Succession patterns of necrophilous insects were documented for the following: one Louisiana black bear (threatened species), two white-tailed deer, two alligators, and two swine as the experimental reference. Our results suggest variation in the species composition of necrophilous insects among animal carcass types. A total of 93 arthropod species, from 46 families and three classes, were manually collected from the seven carcasses. Only 19 insect species were collected on all four animal types and were represented by eight families: Coleoptera: Histeridae, Nitidulidae, Silphidae, Staphylinidae; Diptera: Calliphoridae, Muscidae, Piophilidae, Sepsidae. Eleven of the 46 families were not collected at either alligator site but were observed at bear, deer, and swine carrion: Coleoptera: Cleridae, Dermestidae, Geotrupidae, Scarabaeidae; Diptera: Micropezidae, Sarcophagidae, Syrphidae; Hymenoptera: Apidae; Lepidoptera: Nymphalidae; and Odonata: Libellulidae. Residency and succession patterns of necrophilous insects are presented for each animal type with particular emphasis on selected fly (Calliphoridae, Muscidae, Piophilidae, Stratiomyidae) and beetle species (Cleridae, Dermestidae, Histeridae, Nitidulidae, Silphidae, Staphylinidae).

Alligators and Crocodiles↗
PubMed2000

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Breast Diseases↗
PubMed1989

Timely detection of colorectal cancer in the elderly. Implications of the aging process.

Increased age is a risk factor for colorectal cancer; however, there is a lack of literature that focuses on the early detection of colorectal cancer in the elderly. The nursing process provides the conceptual basis for this article, which discusses normal bowel function, aging changes in the bowel, and colorectal cancer. A nursing care plan for alterations in bowel elimination/constipation is presented as a model.

Aged↗
PubMed1987

Ouabain and low extracellular potassium inhibit PTH secretion from bovine parathyroid cells by a mechanism that does not involve increases in the cytosolic calcium concentration.

We have previously found that high extracellular calcium (Ca++) concentrations inhibit PTH release in association with a threefold to fourfold rise in cytosolic Ca++ concentration. Recent data have also shown that low extracellular potassium (K+) concentration or ouabain also inhibits PTH release to an extent comparable to that seen with high Ca++ and produce a marked rise in the intracellular sodium (Na+) content. These results suggested that low K+ and ouabain might modulate PTH release through increases in cytosolic Ca++ related to alterations in Na+-Ca++-exchange. In the present studies, we have examined further the mechanism(s) by which inhibition of the Na+-K+-ATPase regulates PTH release. Exposure of cells loaded with the Ca++-sensitive dye QUIN-2 to low K+ produced a 10% to 17% increase in cytosolic Ca++ at 0.5 to 1.0 mmol/L extracellular Ca++, which was statistically significant only at 0.75 mmol/L Ca++. In contrast, low K+ caused a statistically significant decrease in cytosolic Ca++ at 1.5 to 2 mmol/L Ca++, while ouabain lowered cytosolic Ca++ significantly by 23% to 46% at all Ca++ concentrations examined (0.5 to 2 mmol/L). Low K+ or ouabain had no effect on cellular levels of ATP or GTP or intracellular pH measured using the pH-sensitive dye BCECF [2', 7'-bis(carboxyethyl)-5,6-carboxyfluorescein]. The inhibition of secretion by low K+ or ouabain, unlike that due to high extracellular Ca++, was not reversed by TPA (12-O-tetradecanoyl phorbol 13-acetate), an activator of protein kinase C. Low K+ did produce a modest (30% to 40%) lowering of agonist-stimulated but not basal cAMP content.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1987

Partial hydatidiform moles: a review.

The current study was undertaken in an effort to identify the clinical characteristics and natural history of partial moles. Three cases recently managed at Tripler Army Medical Center and 52 cases collected from the medical literature were reviewed. The mean age of the women at diagnosis was 25.6 years. The mean gestational age at diagnosis was 23.8 weeks. The most common presenting symptom was vaginal bleeding in 69 per cent of women. Although triploidy was the most frequent karyotype (68 per cent), normal 46,XY or XX karyotypes were present, and phenotypically normal infants were delivered of mothers with a coexisting molar pregnancy. Malignant trophoblastic disease occurred in 14.5 per cent of the women. All of them achieved remission with adjuvant therapy. Partial moles are considered a less virulent form of molar pregnancy. The clinical characteristics and natural history are not entirely dissimilar from the complete mole. Malignant sequelae can occur after the evacuation of a partial mole. These women should be followed with serial serum beta-HCG.

Chorionic Gonadotropin↗
PubMed1984

Extracellular calcium potentiates the inhibitory effects of magnesium on parathyroid function in dispersed bovine parathyroid cells.

We studied the relative potencies of extracellular calcium and magnesium in inhibiting PTH release and dopamine-stimulated cAMP accumulation in dispersed bovine parathyroid cells. At 1.0 mmol/L calcium, PTH release was half-maximally suppressed by 1.8 mmol/L magnesium. At calcium concentrations in the subphysiologic range (less than or equal to 100 mumol), on the other hand, magnesium was markedly less potent as an inhibitor of these parameters. With 1.0 mmol/L EGTA and no added calcium (free calcium less than 10(-8) mol/L), half-maximal inhibition of PTH release accumulation occurred at 10 to 15 mmol/L magnesium. Extracellular calcium also markedly potentiated the inhibitory effects of extracellular magnesium on dopamine-stimulated cyclic adenosine monophosphate (cAMP) accumulation. Low magnesium concentrations (less than 1 mmol/L), on the other hand, had little effect on the sensitivity of parathyroid cells to calcium. These results do not fit a model in which calcium and magnesium independently and additively inhibit PTH release in dispersed bovine parathyroid cells. Instead, they demonstrate that the inhibition of PTH release and agonist-stimulated cAMP accumulation by magnesium are critically dependent on the presence of extracellular calcium but not vice versa. These data suggest that extracellular calcium may play an important role in the mechanism(s) by which extracellular magnesium modulates parathyroid function, perhaps through a magnesium-induced uptake of extracellular calcium.

Animals↗
PubMed1983

Extracellular calcium is not necessary for acute, low calcium- or dopamine-stimulated PTH secretion in dispersed bovine parathyroid cells.

Although elevated extracellular calcium concentrations inhibit PTH release, little is known about the necessity of extracellular calcium for the secretory process in this cell type. In the studies reported here, we examined the effects of low extracellular calcium concentrations on basal and agonist-stimulated immunoreactive PTH (iPTH) release in dispersed bovine parathyroid cells. There was a difference of 15% or less in the rate of iPTH release from cells exposed for 30-60 minutes to calcium concentrations varying from less than 10(-8) mol/L to 1 mmol/L. Low calcium concentrations likewise had no effect on dopamine-stimulated iPTH secretion. We employed high performance liquid chromatography (HPLC) to demonstrate directly that EGTA did not alter the degradation of PTH in the medium and that the release of intact PTH was stimulated slightly by very low extracellular calcium concentrations. Like iPTH release, both the basal and dopamine-stimulated cAMP content in parathyroid cells were unchanged by extracellular calcium concentrations as low as 10(-8) mol/L. Following exposure of cells to EGTA for two or more hours, there was a 50% to 60% inhibition of iPTH secretion. This reduction in secretory rate was not reversible, however, by the readdition of 0.1-1.0 mmol/L calcium for one hour. These results demonstrate that the secretion of PTH differs from that of many other exocytotic systems not only in that hormonal release is inhibited at high extracellular calcium concentrations but also in that extracellular calcium is not needed for acute hormonal release.

Animals↗