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Biomedical subjects

R Irvine

Publications and source records attributed to R Irvine.

36 records · Page 2Linked to original sources
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↗
PubMed1984

Coronary heart disease: account of a preventive clinic in general practice.

Men between the ages of 25 and 45 years attending a surgery were screened for risk of heart disease. An ;at-risk' group of 188 men were identified and 118 of them (63 per cent) accepted an invitation to attend a coronary heart disease prevention clinic at the practice. A sample of the attending group showed favourable changes in risk factors one year later.Subsamples of 20 men from the attending and non-attending groups were interviewed at the clinic or at home; they showed significant differences with respect to employment status, family history of myocardial infarction and knowledge about coronary heart disease as a cause of death in the United Kingdom. Implications for preventive programmes of this nature are discussed, and the need to utilize routine doctor-patient contacts for health education and prevention is stressed.

Adult↗
PubMed1981

Problem drinkers and their problems.

From general practice records of 9,763 patients, 106 problem drinkers were compared with a control group. The drinkers had a substantially higher number of problems and they consulted their doctor and attended casualty departments frequently. Social and marital problems were especially prevalent in the families of problem drinkers.

Accident Proneness↗
PubMedDate not supplied

Inositol phospholipids: translocation, translocation, translocation...

The pleckstrin homology (PH) domains of a number of proteins have been found to interact in vitro with inositol phospholipids; recent experiments show that these interactions may be important in directing protein translocation to specific parts of the cell following stimulus-induced lipid breakdown or synthesis.

Agammaglobulinaemia Tyrosine Kinase↗
PubMedDate not supplied

Effect of simultaneous pulsed hyperthermia and pulsed radiation treatment on survival of SiHa cells.

Relatively mild temperatures (40-41.5 degrees C) can sensitize human cells to radiation without the development of thermal tolerance to radiosensitization. Therefore there may be a therapeutic benefit to adding mild hyperthermia to brachytherapy regimens for the treatment of cancer. However, the required heating times are long (approximately 48 h) which renders this approach somewhat impractical. A novel alternative is to combine pulsed brachytherapy with pulsed hyperthermia to enable the total radiation dose to be given at an elevated temperature while the total heating time is kept short. A treatment schedule in which 1 Gy radiation pulses were given once per hour during 5-min heating pulses also delivered once per hour, was investigated in vitro in the human cervical carcinoma line, SiHa. The degree of cytotoxicity and thermoradiosensitization of the cells were assessed by cell survival using the colony forming assay. Cells were exposed to pulsed hyperthermia alone (5 min at 45 degrees C, delivered once per hour), acute hyperthermia alone (45 degrees C), pulsed radiation alone (1 Gy per hour), acute radiation alone, and simultaneous pulsed hyperthermia and pulsed radiation. Pulsed heating alone caused little cytotoxicity. However when pulsed heating was added to pulsed radiation, the level of cytotoxicity was greater than for pulsed radiation alone or acute radiation alone. The effect was also greater than would be predicted from a simple additive effect of pulsed radiation and pulsed heating. In conclusion, pulsed heating at 45 degrees C sensitized cells to pulsed radiation without the development of thermal tolerance.

Cell Survival↗
PubMedDate not supplied

Towards a dialogical ethics of interprofessionalism.

Contemporary medical practice brings a diverse range of professions and disciplines together in greater and closer contact. This situation of increasing complexity and changing professional roles gives rise to multifaceted ethical dilemmas and theoretical and practical concerns. In this essay we argue that for multidisciplinary relationships to be facilitated and to progress towards interdisciplinary teamwork, moral agents have to go beyond orthodox ethical systems and appeal to normative theory. We will argue that conceptualising ethics as a shared social practice may provide a useful starting point. This dialogic approach places greater emphasis on open deliberation and the articulation, negotiation, exploration and generation of new ethical perspectives in the here and now of clinical practice.

Ethics, Medical↗