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Biomedical subjects

J C Rose

Publications and source records attributed to J C Rose.

At least 145 records · Page 8Linked to original sources
PubMed1981

Effect of verapamil on the pulmonary vasoconstrictor action of prostaglandin F2 alpha and a synthetic PGH2 analogue.

1 The vasopressor response to prostaglandin F2 alpha (PGF2 alpha) and to ((15S)-hydroxy-11 alpha, 9 alpha-(epoxymethano)-prosta-5Z, 13E-dienoic acid) (U-46619) in the canine isolated lung lobe was significantly attenuated following the administration of verapamil. 2 The pressor response to arachidonic acid (AA) was not affected by the presence of verapamil. 3 The pulmonary pressor effect of PGF2 alpha and U-46619 is dependent, at least in part, on Ca2+ influx into vascular smooth muscle cells. 4 The pulmonary pressor response to AA cannot be attributed to PGF2 alpha or to endoperoxide intermediates but to some other product dependent on intracellular calcium stores.

Animals↗
PubMed1981

Hemorrhage in newborn lambs: effects on arterial blood pressure, ACTH, cortisol, and vasopressin.

Arterial blood pressure, central venous pressure, and plasma concentrations of ACTH, cortisol, and vasopressin (AVP) were monitored in chronically prepared, unanesthetized newborn and weanling lambs at rest and during and after hemorrhage of 15% of estimated blood volume at 1.5%/min. Differences in the endocrine and blood pressure responses to hypovolemia were noted in the two groups of animals. Hemorrhage did not change arterial mean pressure, reduced central venous pressure, and caused a delayed increase in the plasma concentrations of ACTH, cortisol, and AVP in the newborn lambs. In weanling lambs, hemorrhage reduced arterial mean pressure and central venous pressure and promptly increased plasma ACTH and cortisol levels while plasma AVP concentrations again showed a delayed increase. The data indicate that certain hormonal mechanisms for the defense of blood volume are present and operational within 3 days of birth and that age-related differences in the responses to hemorrhage exist in the lamb.

Adrenocorticotropic Hormone↗
PubMed1981

Ontogeny of endocrine (ACTH, vasopressin, cortisol) responses to hypotension in lamb fetuses.

We studied the ACTH, vasopressin (AVP), and cortisol responses to nitroprusside-induced hypotension in 27 chronically cannulated lamb fetuses between 0.53 and 0.98 gestation. Age-related differences in the hormonal responses to hypotension were found. Hypotension was associated with peak AVP levels of 7.8 +/- 2.7 pg/ml (mean +/- SE) in animals less than 0.68 gestation and 63.5 +/- 20 pg/ml in animals 0.89-0.98 gestation (P less than 0.05). The peak ACTH response was 95 +/- 20 pg/ml in the youngest animals and 380 +/- 111 pg/ml in animals 0.83-0.88 gestation (P less than 0.05). These observations suggest that maturation of the systems (possibly neuroendocrine) subserving the hormonal responses occurs in utero. Fetal plasma cortisol levels did not increase in response to the increase in ACTH except in animals 0.89-0.98 gestation. At this time, the basal plasma cortisol levels were high (58.8 +/- 16.8 pg/ml) and the ACTH response to hypotension was attenuated. Taken together, these findings suggest functional negative feedback regulation of ACTH by cortisol in the late gestation fetus.

Adrenocorticotropic Hormone↗
PubMed1981

Catheterization of the pulmonary artery in the closed-chest rat.

A simple technique has been devised to catheterize the pulmonary artery in rats for measurement of pulmonary artery pressure. A no. 3 1/2 French umbilical vessel catheter (Argyle), angled to 90 degrees over the distal 1 cm, was introduced into the right external jugular vein of the anesthetized (50 mg/kg pentobarbital sodium, ip) rat (male Wistar, 250-350 g). With the angle directed anteriorly, the catheter was inserted 2.5 cm proximally, which placed the catheter in the right atrium. The catheter was rotated 90 degrees counterclockwise and inserted 1.0 cm further, which placed the catheter in the right ventricle. Advancement of the catheter an additional 1.5 cm allowed placement in the pulmonary artery. Placement at each stage was confirmed by the respective pressure contours. This technique is easily and rapidly performed and has many potential applications in measuring parameters of the pulmonary circulation in a variety of small laboratory animals.

Animals↗
PubMed1981

Alcohol and fetal endocrine function.

Maternal alcohol abuse during pregnancy represents a significant risk to normal perinatal growth and development. The mechanisms involved in the deleterious effects of alcohol on the fetus are unknown but may involve perturbations in fetal endocrine function. Consequently, we have begun to examine the effects of alcohol exposure on thyroid and adrenal cortical function in the chronically cannulated ovine fetus. Our results indicate alcohol exposure in utero affects both the pituitary-thyroid and the adrenal cortical system in the fetus. Fetal pituitary-thyroid function appears depressed and fetal adrenal cortical function increased by alcohol.

Animals↗
PubMed1981

Acute and chronic effects of maternal ethanol administration on the ovine maternal-fetal unit.

The purpose of this study was to examine, in the pregnant ewe and its fetus, some of the physiological consequences of acute and chronic ethanol exposure. Ethanol was infused intravenously (2 g/kg/day over 2 h) to pregnant ewes from day 100 of pregnancy to term. Control animals received isocaloric infusions of 5% dextrose. Animals were pair-fed and allowed water ad lib. Maternal (n = 5) systolic, diastolic, and mean blood pressures and heart rate rose significantly by 1 h after starting ethanol, whereas fetal (n = 4) blood pressure and heart rate did not change during ethanol infusion. Maternal ethanol infusion produced a significant rise (p less than 0.01) in both fetal (n = 8) and maternal (n = 10) plasma cortisol levels. Peak blood ethanol concentration was significantly higher in the ewe (240 +/- 6 mg.dl-1, n = 7) than in the fetus (190 +/- 9 mg.dl-1, n = 6) at the end of the 2-hour infusion. Maternal rate of elimination after ethanol infusion was terminated was 40 mg.dl-1 per hour, while fetal elimination was 10 mg.dl-1 per hour. Body weights and crown-rump lengths of fetuses from 0.82 to 1.0 gestation were significantly less in ethanol-treated animals than in age-matched control animals. Fetal plasma thyroxine and triiodothyronine increments following thyrotrophin-releasing hormone administration were significantly less in alcohol-treated than in control animals. Thus, chronic exposure to ethanol during the latter part of gestation impaired fetal growth and altered fetal endocrine function in these animals.

Animals↗
PubMed1980

Containing the labor costs of food service.

The productivity of hospital food service employees can be increased by improving methods, identifying and eliminating unproductive practices, and reevaluating various policies.

Administrative Personnel↗
PubMed1980

Effects of nitroglycerin and nitroprusside on the uterine vasculature of gravid ewes.

The effects of nitroglycerin (TNG) and sodium nitroprusside (SNP) on mean aortic pressure (MAP), uterine blood flow (UBF), uterine vascular conductance (UVC), and pulse rate (PR) were compared when the two agents were infused to prevent and treat hypertension induced by norepinephrine (NE) in gravid ewes. When infused alone, TNG, 19 microgram/kg/min, decreased MAP 19 per cent and increased PR 33 per cent from control values (P less than 0.05), but did not significantly change UBF or UVC. In comparison, SNP, 3 microgram/kg/min, decreased MAP 20 per cent and increased PR 43 per cent (P less than 0.05), and did not significantly change UBF or UVC. When given alone, four successive 2-min infusions of NE produced dose-related increase in MAP and decreases in UBF, UVC, and PR; values were significantly different from control with the two higher doses of NE. Although MAP, UBF, and UVC were still significantly changed from control levels when NE was given in the presence of the above infusions of TNG or SNP, MAP was lower and UBF and UVC were higher compared with when NE was given alone (P less than 0.05). When given to control hypertension induced by a continuous infusion of NE, TNG or SNP produced uterine vasodilatation and significantly increased UBF. Nitroglycerin and SNP were equally effective in counteracting the maternal hypertension and antagonizing the uterine vascular effect of NE. It is concluded that TNG and SNP counteract uterine vasoconstriction resulting from alpha-adrenergic stimulation and do not produce a shunt of blood flow away from the uterine vasculature when used to control hypertension in gravid ewes.

Animals↗
PubMed1980

Performance of task functions by A.D.A. dietetic technicians.

To meet the professional demands of their positions, dietitians must delegate less demanding responsibilities and routine tasks to educationally qualified dietetic technicians. This research was conducted to determine the degree to which A.D.A. qualified dietetic technicians were performing identified tasks.

Data Collection↗
PubMed1980

Meal timing alters circadian rhythm of skin surface temperature in non-human primates.

Circadian rhythms of skin surface temperature were demonstrated in a group of African green vervets. Alteration of the timing of a single daily meal of fixed caloric content resulted in a shift of the skin surface temperature acrophase in 7 of the 8 series. The timing of the individual temperature acrophases in relation to the light-dark cycle and the extent of acrophase shift in response to alteration of meal timing showed considerable variation between the individual animals studied.

Animals↗
PubMed1979

The effects of induced prenatal hypothyroidism on lamb mandibular third primary molars.

Intrauterine thyroidectomies were performed on nine lambs on or about the ninety-sixth postconception day. Seven other control and shamoperated lambs, and the cretin lambs were sacrificed immediately after birth. The mandibles were removed and sectioned at the midline. The right side molars were removed by dissection and caliper measured. The distal cusps of the third primary molars were sectioned, dehydrated, and embedded in Bioplastic. A slow speed diamond saw was used to section the plastic blocks and the embedded teeth. Subsequent grinding and polishing produced high quality 75 micrometer sections of the lamb molar cusps. No significant differences in tooth size or enamel thickness existed. Microscopic examinations show that parts of the cretin enamel were poorly calcified, an observation that was correlated to the intrauterine thyroidectomies. The data suggest that hypothyroidism alters ameloblastic activity during the secretory phase of enamel formation.

Amelogenesis↗
PubMed1979

Cardiovascular and pulmonary effects of thromboxane B2 in the dog.

The hemodynamic properties of thromboxane B2 (TxB2), a product of prostaglandin endoperoxide metabolism, have not been thoroughly described. TxB2 is a bronchoconstrictor, but its effects on the systemic circulation and circulating platelets are unknown. Its precursor, thromboxane A2(TxA2), is a potent vasoconstrictor as well as a platelet-aggregating agent. Using intact anesthetized dogs, we investigated the effects of TxB2 on pulmonary artery pressure (PAP), airway pressure (AP), systemic arterial pressure (SAP), and myocardial contractility (MC). Vascular responses were evaluated in relation to changes in platelet population and aggregability. Intravenous TxB2 (25 and 50 micrograms/kg) increased AP (mean 62% and 69%) and PAP (50% and 86%), respectively, whereas SAP and MC responses were inconsistent. Left ventricular injections (25 micrograms/kg) also increased AP (36%) and PAP responses were inconsistent. Left ventricular injections (25 micrograms/kg) also increased AP (36%) and PAP (36%). Intraventricular administration of TxB2 produced a consistent elevation of SAP (10%) with a concomitant fall in MC (11%). These vascular responses were not consistent with alterations in platelet number or aggregability. A tachyphylactic response to TxB2 developed in AP and PAP at both dose levels and with both routes of administration. Intravenous and intraventricular TxB2 (25 micrograms/kg) produced a parallel decreasing response in PAP, suggesting the possible saturation of TxB2 binding sites or the depletion of a catabolic enzyme in the lung.

Animals↗