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Biomedical subjects

R Irvine

Publications and source records attributed to R Irvine.

At least 19 recordsLinked to original sources
PubMed1999

Cardiovascular changes during morphine administration and spontaneous withdrawal in the rat.

Morphine maintenance doses of 10 mg kg(-1) day(-1), 20 mg kg(-1) day(-1) and 30 mg kg(-1) day(-1) were administered to three groups of rats via miniosmotic pumps for 7 days to induce physical dependence. They were then allowed to undergo spontaneous withdrawal. Radiotelemetric blood pressure measurements showed that morphine increased systolic and diastolic blood pressure on the first day of morphine treatment and produced a dose dependent decrease in heart rate, systolic and diastolic blood pressure thereafter. After the peak depressive effect, development of tolerance to morphine was observed in systolic and diastolic blood pressure, but not in the heart rate. During spontaneous withdrawal, both systolic and diastolic blood pressure increased beyond pre-morphine levels for all doses and there was a rebound increase in heart rate at the 30 mg kg(-1) day(-1) dose. These results suggest that the improved sensitivity of telemetric measures combined with the use of minipumps for morphine treatment provide an animal model of spontaneous opioid withdrawal.

Analgesics, Opioid↗
PubMed1997

Pulmonary aspergillosis in acquired immune deficiency syndrome: autopsy study of an emerging pulmonary complication of human immunodeficiency virus infection.

Pulmonary aspergillosis has recently been described as an emerging infection in patients with acquired immune deficiency syndrome (AIDS), but the pathological changes have not been well documented. In this autopsy study, 17 cases of AIDS-related pulmonary aspergillosis were identified from the files of two institutions. With the exception of hypersensitivity reactions, the entire spectrum of pulmonary aspergillosis was represented. Thirteen patients exhibited acute invasive aspergillosis, and seven patients had evidence of subacute or chronic invasive infection, four of whom also had areas of acute invasion. One patient had necrotizing bronchial aspergillosis as well as acute invasive infection, and one individual had saprophytic colonization of a cavity caused by previous Pneumocystis carinii pneumonia (PCP) without evidence of invasive aspergillosis. The same conditions known to predispose immunocompromised individuals without human immunodeficiency virus (HIV) infection to invasive pulmonary aspergillosis were also identified in these patients with AIDS and included neutropenia, steroid therapy, and underlying lung disease. Additional pulmonary conditions were identified in all but one case and consisted mainly of infection or some form of chronic lung disease. In particular, half of the cases were associated with pulmonary fibrosis related to prior PCP. All cases occurred in or after 1990, confirming the perception of the recent emergence of aspergillosis in AIDS. As suggested by this study, one reason for this may be that patients with AIDS are now living long enough to develop one or more of the predisposing conditions for pulmonary aspergillosis.

AIDS-Related Opportunistic Infections↗
PubMed1996

Inositol phosphates - whither bound? Intracellular signalling.

Many proteins are being found to bind inositol phosphates with varying degrees of specificity; the variety of domains that can bind inositol phosphates suggests convergent evolution, but the functions of most of the binding sites are not yet clear.

Amino Acid Sequence↗
PubMed1996

Ectopia cordis. Ethical dilemma in a developing country.

Ectopia Cordis is a rare congenital abnormality affecting the heart which is present either totally or partially outside the thorax. Because of associated cardiac defects, survival beyond birth is uncommon. One such case in whom death occurred on the 23rd post-operative day from heart failure is described and the management and ethical considerations discussed. This is the first case which has survived beyond birth in Jamaica.

Cause of Death↗
PubMed1995

Insulin-related growth factor binding protein-1 levels in ovum donation pregnancies.

The finding that endometrial maturation may be delayed following hormone replacement therapy has suggested that a generalised endometrial dysfunction may exist in ovum recipients. In order to investigate this suggestion further, circulating levels of IGFBP-1 were measured in samples taken throughout pregnancies conceived either spontaneously or following ovum donation. When analysed at two-weekly intervals, the serum levels of IGFBP-1 in ovum donation pregnancies failed to show the expected peak towards the end of the first trimester and were significantly reduced at week ten (U = 364.5, p = 0.0002) and twelve (U = 138.0, p = 0.0047). For the remainder of pregnancy, circulating IGFBP-1 levels were similar in both groups. The birth weight of children born to the ovum donation group was not significantly different from a normal control group, suggesting that circulating levels of IGFBP-1 in early pregnancy do not reflect local function and that IGFBP-1 does not have an essential function (in relation to birth weight) in early pregnancy.

Birth Weight↗
PubMed1995

Superovulation, IGFBP-1 and birth weight.

In this study, the effect of superovulation on the circulating levels of insulin-like growth factor binding protein-1 (IGFBP-1) has been investigated. IGFBP-1 levels were measured in singleton pregnancies achieved either naturally (n = 203) or following superovulation, in-vitro fertilisation and embryo transfer (IVF-ET) with either pituitary desensitisation with buserelin and superovulation with human menopausal gonadotrophin (b/hMG) followed by IVF-ET (n = 15) or with clomiphene citrate and hMG (CC/hMG) followed by IVF-ET (n = 15, 1st trimester only). The circulating levels of IGFBP-1 were similar in all three groups during the first trimester, and in both normal and b/hMG pregnancies in the second, but were significantly higher during the third trimester in b/hMG pregnancies than in normal pregnancies (P = 0.0002). The birth weights were significantly lower in the b/hMG group (P = 0.04), but not in the CC/hMG group compared with natural conceptions. Gestational age at delivery was similar in control and b/hMG pregnancies, but significantly reduced in CC/hMG pregnancies (P = 0.04). These data suggest that pregnancies achieved following superovulation with b/hMG are associated with elevated levels of IGFBP-1 during the third trimester of pregnancy and reduced birth weight.

Adult↗
PubMed1994

Regulation of corpus luteum function.

The effects have been studied of different ovulation induction regimens [either clomiphene citrate or buserelin in combination with human menopausal gonadotrophin (HMG)] on the circulating concentrations of progesterone, oestradiol, relaxin and human chorionic gonadotrophin (HCG) during the first trimester of pregnancy. Ovulation induction with clomiphene resulted in elevated concentrations of gonadotrophins in both phases of the cycle, while during ovulation induction with buserelin, gonadotrophin concentrations were elevated in the follicular phase only. The concentrations of all corpus luteum products were greater in clomiphene pregnancies compared with spontaneous pregnancies, but only oestradiol and relaxin concentrations were greater in clomiphene pregnancies compared with buserelin pregnancies. The concentrations of HCG were significantly reduced in clomiphene pregnancies compared to natural pregnancies. Relaxin concentrations were significantly higher from 7 weeks gestation in buserelin compared with spontaneous pregnancies, while progesterone, oestradiol and HCG concentrations were not consistently different. Consistent associations were found between relaxin and HCG concentrations in spontaneous pregnancies and between the concentrations of relaxin and both progesterone and oestradiol in pregnancies achieved after ovulation induction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Corpus luteum failure in ectopic pregnancy.

The endocrinology of ectopic pregnancy was studied in order to investigate the origin of the discordance in the circulating amounts of human chorionic gonadotrophin (HCG) and those of oestradiol and progesterone. Serial maternal blood samples were obtained at 4-9 weeks gestation from 93 patients who became pregnant following in-vitro fertilization and embryo transfer including 10 ectopic, 21 anembryonic and 62 normal singleton pregnancies. The samples were analysed for HCG, Schwangerschaft protein-1 (SP-1), pregnancy-associated plasma protein-A (PAPP-A), progesterone and oestradiol. In ectopic pregnancies, concentrations of all substances analysed were significantly reduced compared to singleton pregnancies from 5 weeks gestation (P < 0.05-0.001) but they were not significantly different from those of anembryonic pregnancies. In ectopic pregnancies, associations were found between the concentration of both HCG and SP-1 and those of progesterone and oestradiol. No associations were found between PAPP-A and any other substances analysed. This may be due to insensitivity of the PAPP-A assay; alternatively PAPP-A concentrations may be differentially reduced in ectopic pregnancy. These findings suggest that progesterone and oestradiol are derived from the corpus luteum in early ectopic pregnancy but that the corpus luteum fails rapidly and the dominant source of both hormones becomes the trophoblast as early as 5 weeks.

Chorionic Gonadotropin↗
PubMed1987

Sinusitis in children.

Sixty-eight children with the primary diagnosis of sinusitis have been admitted to the B.C. Children's Hospital since its opening in 1982 until July of 1986. Sinusitis in children under six years differs in presentation and course from sinusitis in older children. Children under six years seem to respond well to antibiotics while some children over six need surgery. Underlying diseases were present in half the cases and should be searched for in children who present with recurrent sinusitis.

Adolescent↗