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Biomedical subjects

J R Davis

Publications and source records attributed to J R Davis.

At least 271 records · Page 15Linked to original sources
PubMed1980

The establishment and morphologic characterization of finite cell lines from normal human endometrium.

Twenty-nine samples of normal human endometrium have been initiated in tissue culture. Twenty cultures (69%) demonstrated sufficient growth in vitro to allow establishment of finite cell lines. Morphologic characterization by means of conventional light microscopy as well as scanning and transmission electron microscopy was performed. Differences between stromal and epithelial cell lines indicated several similarities with in vivo observations. Ultrastructural studies of stromal cell lines revealed cells virtually devoid of microvilli and exhibiting poorly specialized cell junctions. Epithelial cell lines were characterized by numerous microvilli and highly specialized "junctional complexes" typical of glandular epithelium. Cytogenetic analysis utilizing a variety of banding techniques revealed no karyotypic alterations through several subpassages. Our observations suggest that simple explant tissue culture of human endometrium can be manipulated in order to achieve separation of stromal from epithelial elements, allowing critical examination of each.

Cell Line↗
PubMed1980

Further observations on a 13qXp translocation associated with retinoblastoma.

In a patient with a 13qXp translocation and retinoblastoma the band associated with retinoblastoma (13q14) was clearly translocated intact to the X chromosome rather than being the breakpoint of the translocation. Genetic inactivation of the derivative X chromosome shown by late labeling and cell hybridization techniques in the predominance of cells indicated a functional monosomy for this segment as the most likely predisposing factor in producing retinoblastoma.

Chromosomes, Human, 13-15↗
PubMed1980

Metrizamide sagittal tomography: adjunct to CT cisternography of the sellar region.

A total of 30 patients with pituitary adenoma was studied by sagittal polytomography en route to coronal and axial computed tomography (CT) cisternography after a low FDA-approved dose of 6 ml of 170 mg I/ml metrizamide via lumbar injection. The requirement for defining the relation of the optic nerves and chiasm to the intrasellar contents or suprasellar mass before proton beam irradiation or certain surgical approaches was satisfied. Pneumoencephalography as a supplemental procedure to CT and CT cisternography was replaced. The concomitant elimination of conventional sellar polytomography and pneumoencephalography results in decreased total radiation exposure and a more comfortable, expeditious workup.

Adenoma↗
PubMed1979

Sensitivity of mammography and physical examination of the breast for detecting breast cancer.

Mammography and physical examination of the breast are evaluated as screening instruments for detecting breast cancer based on local biopsy data obtained from women enrolled in a national breast cancer screening program. One hundren thirteen cancers (15.5%) of women who underwent biopsy) were detected. The individual sensitivities of mammography and physical examination for detecting breast cancer are 62% and 24%, respectively. The sensitivity of the two methods combined is 75% (85 of 113). Thirty-seven cancers were in situ or minimally invasive (less than or equal to 1 cm in greatest dimension). Eighty-one percent (30 of 37) of these small cancers were detected by screening, and they comprised 35% (30 of 85) of all cancers detected by mammography, physical examination, or both. Improved survival is anticipated due to this high rate of discovery of small cancers.

Adult↗
PubMed1979

Weight loss, slower growth and lower fasting heat production rates following LH lesions in female rats.

Lesions in the lateral hypothalamus (LH) can result in a permanent loss of body weight and slower growth in female rats, but do not do so invariably. Weight and growth rate changes were always accompanied by lower rates of fasting heat production (FHP) independent of changes in activity. The thyroids of these animals were significantly below normal in size. None of the traditional deficits of the "LH syndrome" were present: the animals ate when deprived of water: drank when deprived of food (although less than the control animals) and increased their food intakes when injected systemically with insulin, at least on the initial test. With repeated tests the food intake following insulin-induced hypoglycemia declined both in the animals with lesions and in the animals whose body compositions and weights had been lowered to the same levels.

Animals↗
PubMed1979

Weight loss following LH lesions independent of changes in motor activity or metabolic rate.

Lesions in the lateral hypothalamus (LH) which resulted in aphagia and a significant loss in body weight, did not reduce either the running wheel activity or the stabilimeter activity of the animals. Following recovery, the animals failed to regain the lost weight. They had normal food and water intakes under ad lib conditions, and ate food when water deprived. They did not drink when deprived of food. Both control and LH animals also had higher than normal oxygen consumption rates. However, the LH group was not higher than the controls postoperatively. These data argue against their being a unitary LH lesion syndrome and suggest that the chronic weight loss seen in animals with LH lesions is not a secondary consequence either of having disrupted the pituitary-thyroid axis, or of having changed the animals' spontaneous activity levels.

Animals↗
PubMed1979

Effect of ageing on the response of the rat isolated testicular capsule to norepinephrine, acetylcholine and prostaglandins.

The response of the rat isolated testicular capsule to norepinephrine (NE), acetylcholine (ACh) and prostaglandins (PG) was found to be age-dependent. The testicular capsular contractions attributable to smooth muscle cells located within the tunica albuginea may be involved in the transport of non-motile spermatozoa from the testis and into the epididymis. With an increase in age of the age of the rat there was a concomitant increase in mass of the testis, thickness of the capsule and the amount of smooth muscle fibers present in the tunica albuginea. The response to the addition of equimolar concentrations of NE and PGA2 became progressively greater as the age of the animal increased. However, the response of the testicular capsule to ACh remained constant throughout adulthood, while PGF2 alpha became progressively less stimulatory as the age of the animal increased. These findings suggest that neurohumoral agents may have an important role in the maintenance of testicular capsular contractions with regard to ageing.

Acetylcholine↗
PubMed1979

Response of the rabbit isolated testicular capsule at hypothermic and hyperthermic temperatures to norepinephrine, acetylcholine and prostaglandin F2 alpha.

Spontaneous contractions of the adult rabbit isolated testicular capsule were found to be influenced by moderate hyperthermic and hypothermic temperature changes. The decrease in testicular capsular spontaneous contractions resulting from an exposure to 32, 40 and 42 degrees C have been shown to be influenced by the addition of NE, ACh and PGF2 alpha. Of the three neurohumoral agents studied, NE was found to cause the greatest increase and re-initiation of testicular capsular tone during both hypothermia and hyperthermia. These data indicate that endogenous levels of neurohumoral agents may play an important role in the maintenance of testicular capsular tone during exposure to hyperthermic or hypothermic conditions.

Acetylcholine↗
PubMed1979

Alpha-thalassemia in blacks is due to gene deletion.

We used molecular hybridization to test if alpha-thalassemia is due to gene deletion in the black. In 10 families with clinically well-defined alpha-thalassemia-1 (alpha-thal-1), hydribization of alpha-globin cDNA was reduced to the same level as that found in Asians with alpha-thal-1, where two of the four normally present alpha-globin genes are deleted. A black child with hemoglobin H (Hb H) disease also has three globin genes deleted, as do Asian patients with Hb H disease. We conclude that alpha-thalassemia in the black is most commonly due to gene deletion.

Black People↗
PubMed1978

Cryocoagulation of the endometrium at the uterine cornua.

A cryoprobe that will produce coagulation necrosis and subsequent scar formation of the cornual areas of the uterus has been tested. A discussion is made of the developmental program, including the design of the instrument, efficacy and safety testing in baboons, and preliminary investigations of the safety of this procedure in man.

Animals↗
PubMed1978

Bilateral primary germ cell testicular tumors: report of four cases and review of the literature.

Bilateral primary germ cell tumors of the testicle are rare. The last comprehensive review of the literature (1955) revealed a 1.6% incidence. However, during the past twenty years, cases have been reported more often, raising the questions of increased frequency due to prolonged survival following surgery and/or roentgen therapy for unilateral tumors. A search of the medical journals during the past two decades fails to show any increased frequency of bilaterality (1.56%). All general combinations of cell types may occur and the tumors may appear simultaneously or sequentially. Successive seminomas are seen more often followed in frequency by concurrent seminomas. Although 50% of the second primaries were diagnosed within five years, 3% of the patients developed the second tumor after 20 years, stressing the need for extended follow-up. Factors affecting the diagnosis, management and prognosis of bilateral testicular tumors are discussed. Four additional cases of bilateral germ cell tumors are described.

Adult↗