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Biomedical subjects

C A Price

Publications and source records attributed to C A Price.

At least 37 records · Page 2Linked to original sources
PubMed1998

Post-war immigration: 1947-98.

This is the text of the 1998 "W. D. Borrie Lecture [presented at the] Australian Population Association National Conference.... Post-war immigration to Australia is a truly vast subject, covering more than 50 years with over ten Prime Ministers and numerous Ministers of Immigration.... I cannot possibly treat the whole topic and, as I have been asked to make this talk both non-technical and entertaining, I will deal with it in a very general way." Aspects considered include migration policy, ethnic composition, and age distribution.

Age Distribution↗
PubMed1998

Effects of in utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on serum androgens and steroidogenic enzyme activities in the male rat reproductive tract.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been shown to impair reproductive function of males in animal models, possibly due to a reduction in serum androgen levels. Thus, TCDD may alter the testosterone biosynthetic pathway in the testis or the conversion of testosterone to 5alpha-dihydrotestosterone (DHT) in androgen target tissues. Pregnant Sprague Dawley rats were gavaged with TCDD (0, 0.2 or 1.0 microg/kg) on day 15 of gestation only. TCDD caused a reduction in the body weight gain of the dams in both dose groups and a significant reduction in litter size in the higher dose group. Litters delivered normally and TCDD exposed male offspring grew at the same rate as controls. Males were sacrificed at 15, 30, 45, 60, 90 and 120 d of age. Steroidogenic enzyme activities were determined in testicular microsomes and androgen target tissue nuclear fractions. Serum androgens were measured by radioimmunoassay (RIA). At 30 d of age, rats exposed to 1.0 microg/kg TCDD exhibited lower 17-hydroxylase activity (P < 0.05) and lower caput-corpus epididymal weights (P < 0.05). At 45 d of age, the same treatment resulted in testicular 3beta-HSD, 17beta-HSD and 5alpha-reductase activities that were significantly greater (P < 0.05) but, conversely, serum androgens were one quarter the values evident in controls (P < 0.05). At the other ages, no differences were observed in serum androgens and, with the exception of lower 17beta-HSD activity at 90 d of age (P < 0.05), no other differences in testicular steroidogenic enzyme activities were found. 5Alpha-reductase activities in the androgen target tissues were also unchanged. Histological examination of testes showed that the spermatogenic profile was identical to controls at all ages.

3-Hydroxysteroid Dehydrogenases↗
PubMed1998

Lipid-based delivery systems for improving the bioavailability and lymphatic transport of a poorly water-soluble LTB4 inhibitor.

Ontazolast is a potent inhibitor (IC50 = 1 nm) of calcium ionophore A23187-stimulated leukotriene B4 (LTB4) biosynthesis in human peripheral blood leukocytes. The compound is practically insoluble in water (0.14 microgram/mL) and previous studies in animals have demonstrated extensive presystemic drug clearance through hepatic first-pass metabolism. Bioavailability of a suspension formulation in rats was less than 1%, but increased to approximately 9% when administered as a 20% soybean oil-in-water emulsion. The emulsion formulation and three additional lipid-based formulations were administered by gavage to conscious, minimally restrained rats in a novel, double-cannulated model to determine the effects of formulation on systemic blood absorption and mesenteric lymph transport of ontazolast. The bioavailability of ontazolast was significantly and substantially enhanced by all of the lipid-based formulations. While these formulations also significantly increased the amount of ontazolast transported by the lymph, the total amounts transported were insufficient to account for the improvement in bioavailability, which may be due to the elimination or reduction of the barriers of poor aqueous solubility and slow dissolution to absorption of ontazolast from the gastrointestinal tract, or the effects of lipid on the gastrointestinal membrane permeability, transit time, or metabolism of ontazolast. Semisolid SEDDS formulations, composed of Peceol and Gelucire 44/14, produced bioavailability similar to the emulsion formulation. The total amount of ontazolast transported by the lymph varied directly with the amount of concurrent triglyceride transport and appeared to be favored by formulations that prolong gastric emptying time or promote rapid absorption of ontazolast from the gastrointestinal tract.

Administration, Oral↗
PubMed1998

Levels of messenger RNA encoding ovarian receptors for FSH and LH in cattle during superovulation with equine chorionic gonadotrophin versus FSH.

This study tested the hypothesis that luteal LH receptor (LHr) and follicular LHr and FSH receptor (FSHr) steady-state mRNA levels are greater during superovulation with equine chorionic gonadotrophin (eCG) compared with that with FSH. Heifers were stimulated with eCG (n = 10) or FSH (n = 10), and ovaries were recovered the day before and at 12 and 24 h after luteolysis was induced with prostaglandin F2 alpha (PGF2 alpha). Total RNA was purified from individual follicles and corpora lutea. Steady-state levels of LHr and FSHr mRNA were assessed by slot blot analysis employing homologous cDNA probes. There were no differences in luteal LHr between FSH- and eCG-stimulated animals before luteolysis, and hybridization signals were detected in only one of six animals by 12 h after injection of PGF2 alpha. After PGF2 alpha injection, steady-state levels of follicular LHr were 4-fold lower (P < 0.05) and follicular FSHr mRNA levels were 2.4-fold lower (P < 0.05) in eCG- compared with FSH-treated cattle. In eCG-treated animals, induction of luteolysis led to a significant increase in follicular LHr mRNA levels (P < 0.01) and a significant decrease in follicular FSHr mRNA levels (P < 0.01). There was no such effect of luteolysis in FSH-treated animals. We conclude that superovulation with eCG, compared with FSH, results in lower follicular levels of LHr and FSHr mRNA but does not affect luteal LHr mRNA levels.

Animals↗
PubMed1998

Net settler migration to Australia by birthplace: 1947-98.

"Between 1947 and 1998 there was a net inflow of 4.8 million migrants to Australia. Only 29.6 per cent were born in Britain and Ireland. Other surprising findings are that more were born in Indo China than Greece and Cyprus and that more were born in New Zealand than Italy."

Australia↗
PubMed1997

Ovarian follicular steroidogenic acute regulatory protein, low-density lipoprotein receptor, and cytochrome P450 side-chain cleavage messenger ribonucleic acids in cattle undergoing superovulation.

Ovarian hyperstimulation with eCG in cattle results in increased plasma estradiol and progesterone concentrations, whereas hyperstimulation with FSH increases only estradiol concentrations. This study tested the hypothesis that eCG, compared to FSH, increases mRNA abundance for steroidogenic acute regulatory protein (StAR), low-density lipoprotein receptor (LDL-R), and/or cytochrome P450 cholesterol side-chain cleavage (P450scc), the main elements of the progesterone biosynthetic pathway. Heifers were stimulated with eCG (n = 10) or commercial FSH (n = 10), and ovaries were removed by colpotomy the day before and at 12 and 24 h after luteolysis was induced with prostaglandin (PG) F2alpha. RNA was extracted from individual follicles, and relative abundance of StAR, LDL-R, and P450scc mRNA was assessed by slot blots. In ovaries of abattoir origin, StAR mRNA was detected in all follicles and was present in the theca but not the granulosa cell layer, as shown by Northern blotting. Levels of StAR mRNA increased 2-fold (p < 0.05) after PGF2alpha injection in small (< 6 mm) follicles from eCG-treated but not from FSH-treated animals. After PGF2alpha, injection, StAR mRNA levels were 2- to 3-fold higher (p < 0.01) in large (> 9 mm) and medium (6-9 mm) follicles in eCG- compared with FSH-treated heifers. In contrast, P450scc and LDL-R mRNA levels did not consistently differ according to treatments. We show that StAR is expressed in the theca cells of bovine follicles and that stimulation with eCG increases follicular accumulation of StAR mRNA in comparison to stimulation with FSH.

Animals↗
PubMed1997

Follicle-stimulating hormone stimulates circulating gonadotropin surge-attenuating/inhibiting factor bioactivity in cows.

This study aimed to determine whether superovulation in cattle stimulates gonadotropin surge-attenuating/inhibiting factor (GnSAF/IF) bioactivity, as it does in humans. Blood samples were collected from cows (n = 7 per treatment) at -4, 8, 20, 32, 44, 56, and 68 h after injections of saline, eCG, or FSH. Equal volumes of plasma at each treatment and time point were pooled, and GnSAF/IF and inhibin bioactivities were measured using an established rat pituitary cell culture bioassay. Plasma from saline- and eCG-treated cows had little effect on GnRH-induced LH secretion (116.3 +/- 8.3%-81.6 +/- 6.0% of control), while plasma from FSH-treated cows produced a time-dependent suppression of GnRH-induced LH secretion, falling to 64.6 +/- 4.0% of the control value at 56 h after first FSH injection (p < 0.001). The GnSAF/IF bioactivity from the 56-h plasma eluted at pH 5.73 by pseudochromatofocusing-similar to the GnSAF/IF isoelectric point value of 5.81 determined using serum from superovulated women. Plasma from FSH-treated cows reduced basal FSH secretion more than plasma from eCG-treated cows (to 55.5 +/- 5.7% and 63.2 +/- 6.6% of the control value, respectively, p < 0.01) although immunoreactive inhibin concentrations were similar between the two groups. We conclude that FSH, but not eCG, treatment causes a time-dependent production of circulating GnSAF/IF bioactivity in cattle.

Animals↗
PubMed1997

The value of IDPN as a supplemental therapy when elderly patients fail to thrive--two case studies.

On the last day of his life, H.J. came into the dialysis unit smiling and joking. He spent the time watching a movie and visiting with visitors and staff. He reported feeling better than he had in a long time. His predicted 3-day death watch had become nearly 5 months of improved quality of life and precious time spent with his large extended family. He frequently expressed gratitude for the chance to prolong those few days into such an unexpected extension. He and his family attributed this gift to the nursing care and encouragement he received in the dialysis unit. Everyone was aware that the IDPN therapy, along with improvement in his own daily nutritional intake, was a critical element. Later that night, H.J. had a cardiac arrest, and he died peacefully at home with his family. There is no doubt that without the financial resources available to him to pay for his IDPN, the outcome would not have been the same. As it was, all the intended patient outcomes were achieved.

Aged↗
PubMed1997

Patient, nurses, and physicians collaborating in the management of a patient following autotransplant parathyroidectomy.

The nephrology nurses in collaboration with the nephrologist worked closely to avoid severe symptomatology related to calcium phosphorus imbalance. The surgical team support was discontinued 48 hours after the removal of the autotransplant. The patient exhibited classic signs of secondary hyperparathyroidism, as indicated by laboratory tests, anemia, and pruritus. Despite the level of anemia, the patient did not complain of fatigue or dyspnea. A hypocalcemic crisis was avoided by the ongoing assessment and intervention the patient received from the nursing staff. Four of the five stated goals were met. The patient is free of disability as evidenced by steady gait, normal range of motion, and adequate muscle strength. The calcium and phosphorus levels and the calcium phosphorus product are within acceptable ranges (see Figure 1). J.I. has always had information about diet and medication management but has demonstrated variable adherence to the regimen. However, the nephrology nurses plan to continue with counseling and education as needed.

Adult↗
PubMed1997

ANNA's brief of the response to the report of the taskforce on health care workforce regulation.

In December 1995 the Pew Health Professions Commission, a program of the Pew Charitable Trust, released its report titled "Reforming Health Care Workforce Regulations: Policy Considerations for the 21st Century." One of ANNA's external projects for the 1996-97 year was responding to the Commission's report. Western Region Vice President Christine Mudge was selected to serve as project director. In consultation with President Christy Price, she spearheaded ANNA's formal response. Each of the 10 recommendations was assigned to six to eight ANNA members, plus everyone was invited to comment on any portion of the report that they chose. Letters of request for participation were mailed to 66 nephrology nurses. The Board of Directors, committee chairpersons, past ANNA leaders, ANNA consultants, and members at large were involved. The response rate was 59%, or 39 thoughtful critiques of the Commission's recommendations. As project director, Christine Mudge analyzed all responses and formed a draft document. Every effort was made to include all concerns and issues raised by the ANNA participants. The draft document was reviewed at the November ANNA Board of Directors meeting and accepted with some editorial changes. ANNA's response is a 35-page document. Excerpts from ANNA's full response are included on the following two pages. Any ANNA member who desires to receive a copy of ANNA's full response to the Pew Health Professions Commission report may request a copy from the ANNA National Office by calling (609) 256-2320. The Pew Commission is now in the process of reviewing all responses and recommendations to its report. Stay informed by following the ongoing story in the ANNA Update.

Humans↗
PubMed1996

Interrelationship between plasma estradiol concentration and oxytocin-induced PGF2alpha release in heifers.

The objective of this study was to determine if the increase in responsiveness to oxytocin toward the time of luteolysis was correlated with an increase in plasma estradiol in the cow. Six heifers each had a cannula placed in the jugular vein on Day 14 of the estrous cycle. Then, beginning on Day 15, growth of the largest follicles was determined by ultrasonography, and a blood sample was taken via the cannula for the measurement of progesterone and estradiol by radioimmunoassay (RIA). After the first blood sample, 3 more samples were taken at 10-min intervals, 100 IU oxytocin were injected into the vein, and a further 3 blood samples were taken at 15, 30 and 60 min after injection. The concentration of 13,14-dihydro-15-keto prostaglandin F2alpha (PGFM) was measured in these frequent samplings and was used to determine the ability of oxytocin to stimulate PGF2alpha release from the uterus. This procedure was repeated daily for at least 7 d. The results showed that the response to oxytocin increased before luteolysis and that there was a significant increase in the response to oxytocin (P<0.05) before any changes in plasma estradiol or progesterone were detected. These data show that an increase in estradiol secretion from the ovulatory follicle does not appear to initiate luteolysis.

Journal Article↗
PubMed1996

Steroidogenic acute regulatory protein in bovine corpora lutea.

Steroidogenic acute regulatory protein (StAR) transfers cholesterol from the outer to the inner mitochondrial membrane to initiate steroidogenesis. Our purpose was to determine the tissue distribution of StAR mRNA and the occurrence of StAR gene products in the bovine corpus luteum (CL). Tissues were taken from the slaughterhouse or by ovariectomy of cattle at specific times after estrus or ovulation. StAR mRNA was identified by Northern analysis employing a 1.6-kb cDNA mouse StAR probe, and polyclonal antiserum against mouse StAR was used in Western analysis of StAR protein in bovine luteal tissue. The mRNA for cytochrome P450 side-chain cleavage enzyme (P450scc) was also evaluated by means of a homologous cDNA probe. Two isoforms of StAR mRNA, approximately 2.9 and 1.8 kb, were present in bovine CL, adrenal, theca, and granulosa cells and caruncles and cotyledons. One, or sometimes two, protein bands were recognized by the mouse StAR antiserum. P450scc mRNA colocalized in all sites where StAR mRNA was found, and in bovine liver. StAR mRNA was low in developing CL, increased 9- to 15-fold during the mid- to late-luteal phase, and disappeared in CL that had regressed. StAR protein concentrations were highly correlated with StAR mRNA throughout the estrous cycle (r = 0.93, p < 0.05). P450scc mRNA abundance did not vary through the luteal phase except for its disappearance in regressed CL. Corpora lutea from intact animals treated with prostaglandin F2 alpha displayed a 50% decline in StAR mRNA over 12 h while P450scc mRNA remained unchanged. At 24 h StAr mRNA was undetectable, while P450scc mRNA had declined to 50% of pretreatment values. We conclude that StAR mRNA and protein are tightly coupled in the bovine CL, being present at low levels during CL development and in elevated concentrations during the midluteal phase, and disappearing in regressed CL within 24 h of prostaglandin-induced luteolysis. We have further shown, for the first time, that StAR mRNA is present in the mammalian placenta.

Animals↗
PubMed1996

Follicular 3 beta-hydroxysteroid dehydrogenase and cytochromes P450 17 alpha-hydroxylase and aromatase messenger ribonucleic acids in cattle undergoing superovulation.

In this study, we tested the hypothesis that there is altered abundance of transcripts of genes coding for the enzymes cytochrome P450 17 alpha-hydroxylase (P450(17 alpha)), cytochrome P450 aromatase (P450arom), and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) in follicles of cattle hyperstimulated with eCG compared to FSH. Treatments were initiated on Day 10 of the cycle, and all cows received prostaglandin (PG) on Day 12. In experiment 1, blood samples were taken to determine plasma progesterone and estradiol concentrations during ovarian stimulation. In experiment 2, both ovaries were removed from stimulated cows by colpotomy before (n = 4 cows/treatment) and at 12 (n = 3/treatment) and 24 h (n = 3/treatment) after PG injection, and from nonstimulated controls (n = 4) 72 h after PG. The preovulatory follicle from nonstimulated heifers, and all follicles greater than 3 mm in diameter from superovulated heifers, were isolated and classified as small (3-5 mm), medium (6-9 mm), or large (> 9 mm). Steady-state levels of RNA for 3 beta-HSD, P450(17 alpha), and P450arom genes were determined by Northern analysis in the individual follicles. In experiment 1, stimulation with eCG significantly (p < 0.01) increased plasma progesterone concentrations compared to FSH-stimulated and nonstimulated controls, and increased (p < 0.05) plasma estradiol concentrations compared to FSH-stimulated controls. Stimulation with FSH did not alter progesterone concentrations, but significantly increased plasma estradiol concentrations compared to those of controls. In experiment 2, the number of large follicles increased significantly with time (p < 0.01), but there were no differences between eCG and FSH treatments in size distribution of follicles (p > 0.05). Relative abundance of P450(17 alpha) message (per 20 micrograms RNA) was significantly higher in large and small follicles (p < 0.05) in eCG-treated compared to FSH-treated heifers after PG injection. Analysis within this period revealed significant treatment effects at 12 h but not 24 h after PG injection. The bovine P450arom cDNA hybridized to 3 transcripts: a 6.5-kilobase (kb) polyadenylated transcript, and non-polyadenylated messages of 3.4 and 1.8 kilobases (kb), all of which hybridized with an oligonucleotide probe specific for the heme-binding region. In medium and small follicles, the 6.5-kb and 3.4-kb transcripts were present in similar quantities, and the 1.8-kb transcript was 25% less abundant. In large follicles recovered after luteolysis, the 3.4 and 1.8-kb transcripts were 3- to 4-fold more abundant in eCG-treated compared with FSH-treated and nonstimulated animals (p < 0.05). There were no significant differences between eCG and FSH treatments on steady-state 3 beta-HSD mRNA levels. Levels of 3 beta-HSD and P450(17 alpha) mRNA in large follicles in hyperstimulated heifers were not different from those in preovulatory follicles in nonstimulated cows. We conclude that hyperstimulation with eCG results in greater stimulation of follicular P450(17 alpha) message abundance compared to hyperstimulation with FSH, and that this may contribute to increased follicular estradiol secretion.

3-Hydroxysteroid Dehydrogenases↗
PubMed1996

Oocyte quality in small antral follicles in the presence or absence of a large dominant follicle in cattle.

The aim of these experiments was to determine whether the presence of a dominant follicle affects the developmental competence of oocytes from small antral follicles of cattle. In Expt 1, oocytes or follicular fluid samples were collected from follicles 2-7 mm in diameter before (day 3 of the oestrous cycle; n = 4) or after (days 6 and 7 of the oestrous cycle; n = 6) emergence of the first wave dominant follicle (verified by rectal ultrasonography). Five to ten follicles were aspirated for the determination of individual follicular fluid concentrations of oestradiol, progesterone, testosterone and dimeric inhibin; oocytes from the remaining follicles from each cow were pooled and developmental capacity assessed by in vitro fertilization and maturation. In Expt 2, ovaries containing a young corpus luteum and with or without a large oestrogen-active follicle were collected from the abattoir. Follicular aspirates from small follicles in each pair of ovaries were pooled, and oocyte quality and steroid concentrations were determined. In Expt 1, small follicles obtained before emergence of the dominant follicle contained significantly more oestradiol than they did after emergence (19.5 +/- 1.5 versus 0.7 +/- 1.1 ng ml-1, respectively; P < 0.05), but there were no significant differences in concentrations of progesterone, testosterone or dimeric inhibin. The percentage of blastocysts obtained from oocytes collected before (12.1 +/- 9.0) or after emergence (11.8 +/- 7.0) of the dominant follicle did not differ significantly (P > 0.05). In Expt 2, follicular steroid concentrations did not differ in small follicles taken in the presence versus the absence of a large oestrogen-active follicle, and there were no differences in the developmental capacity of the oocytes. There were significant negative correlations between follicular oestradiol concentration and the percentage of blastocysts formed from two-cell (r = -0.90; P < 0.01) and eight-cell embryos (r = -0.65; P < 0.05). These data suggest that in cattle the developmental competence of oocytes from small antral follicles is not adversely affected by the presence of a dominant follicle.

Animals↗