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Biomedical subjects

W Collins

Publications and source records attributed to W Collins.

At least 19 recordsLinked to original sources
PubMed1991

Ovarian morphology, endocrine function and intra-follicular blood flow during the peri-ovulatory period.

Transvaginal ultrasonography with colour flow mapping has been used to study changes in intra-follicular morphology and blood flow during a peri-ovulatory period in one volunteer. Aspects of uterine morphology and blood flow were also recorded. The intervals from a defined luteinizing hormone (LH) rise and peak to the mean time of follicular rupture were 37.5 and 17.5 h, respectively. Blood flow velocity waveforms were observed clearly at the time of the LH rise and blood vessels were visible when the hormone level reached a peak. Concurrently, the wall of the follicle became less clear, crenated, thicker and more echogenic. A structure resembling the detached cumulus and oocyte was seen before the follicle had ruptured. Peak systolic blood velocity was highest immediately after ovulation had occurred. Blood flow impedance in the uterine arteries suggested the presence of a circadian rhythm, but no pronounced daily changes were observed over the study period. In contrast, flow velocity waveforms were clearly visible in the endometrium around the time of ovulation. These preliminary data suggest that intra-follicular vascularization or angiogenesis may be critical processes that might be used to predict ovulation and could possibly be modified to help achieve or avoid a pregnancy.

Adult↗
PubMed1990

Influence of superovulation on endometrial and embryonic development.

The authors have studied the temporal relationship between follicular rupture and endometrial development in 13 women during a natural ovarian cycle (length 25 to 35 days), and subsequently after standard treatment with clomiphene citrate, human menopausal gonadotropin and human chorionic gonadotropin (hCG) to induce multiple folliculogenesis for oocyte recovery, in vitro fertilization, and embryo freezing (cycle length 23 to 27 days). An endometrial biopsy was taken during both cycles 1.5 to 2.0 days after the oocytes had been released or removed. The samples were examined by light and transmission electron microscopy. Samples of peripheral blood were taken at defined times for hormone analysis. After treatment 11 subjects (85%) had advanced morphological development of the endometrium (8 women by 3 to 4 days, 3 women by 1 to 2 days). The concentrations of plasma estradiol (E2) and progesterone (P) on the days of follicular rupture and endometrial biopsy were significantly raised in the treatment cycles. The concentration of total urinary estrogens on the day of hCG administration and the mean change in the concentration of plasma E2 (treatment/control) on the days of endometrial biopsy were positively correlated with the extent of endometrial advancement. In addition, the mean change in the concentration of plasma P (treatment/control) was markedly increased on the days of follicular rupture and endometrial biopsy in those subjects with an advanced endometrium. Embryonic development was not so obviously related to the extent of superovulation. Asynchronous endometrial and embryonic development may therefore contribute to the low pregnancy rate in these patients.

Adult↗
PubMed1989

Studies on folliculogenesis and in vitro fertilization outcome after the administration of follicle-stimulating hormone at different times during the menstrual cycle.

The authors have undertaken a prospective, randomized clinical trial of six treatments to optimize folliculogenesis in patients prior to oocyte collection, in vitro fertilization, and embryo transfer. All treatments involved the administration of the same daily dose of follicle-stimulating hormone (FSH), but at different times during the antecedent and/or current menstrual cycle. There was a significant difference (P less than 0.01, chi-square test) between treatments in the clinical pregnancy rate/patient (19 clinical pregnancies, 67 patients). No advantages were observed for regimens that involved starting treatment during the antecedent cycle. The study was continued with the three treatments that started during the current cycle (24 clinical pregnancies, 58 patients). The most cost-effective regimen was clomiphene citrate, 100 mg/day for days 2 to 6 inclusive; FSH, 150 units/day for days 1 to 4 inclusive; and human menopausal gonadotropin, 150 units/day from day 5 until the day of human chorionic gonadotropin administration.

Adult↗
PubMed1989

A nonseparation, time-resolved fluoroimmunoassay to monitor ovarian function and predict potential fertility in women.

The authors describe a nonseparation, time-resolved fluoroimmunoassay involving the use of monoclonal antibodies for the measurement of estrone-3-glucuronide in urine. The method has appropriate sensitivity (12 nmol/l), better specificity than a conventional radioimmunoassay with polyclonal antibodies, and the advantages of speed, simplicity, less imprecision, and improved clinical effectiveness. The labeled antigen is a novel fluorescent europium chelate covalently linked to estrone glucuronide at carbon 6 of the glucuronide moiety. The antibodies were raised against estrone-3-glucuronyl-6-bovine serum albumin. The antibody binding reaction is performed in microtiter wells (or tubes) and involves the addition of labeled antigen in buffer (2 ng/100 microliters), a limited concentration of antibodies in buffer (100 microliters), and standard or urine sample (10 microliters). The mixture is incubated for 15 minutes at room temperature. Time-resolved fluorescence from the unbound label is proportional to the concentration of estrone glucuronide. The method may be used to monitor ovarian function and potential fertility in women.

Estrone↗
PubMed1989

Method for home monitoring of urinary amylase after pancreas transplantation.

Urinary amylase activity (UAA) is used for diagnosis of rejection in bladder-drained pancreas grafts. Unfortunately, most rejection episodes occur after the patient has been discharged. In those cases, an early diagnosis is often difficult, and a method for home UAA monitoring is needed. We have developed a method that can be used for this purpose. The method, based on Kodak dry-film technology, is shown to have good response to the wide range of UAA seen in these patients compared with responses to standard laboratory kinetic methods. The analysis (performed by the patient) involves 1) collecting urine for 24 h in a 4-L container, 2) diluting the urine with tap water to a total urine of 4 L, and 3) placing a drop of this dilution onto a slide. The slide is read by a handheld spectrophotometer that displays the UAA in secreted units per hour. The reliability of this system has been tested for wide changes of urine pH, volume of the drop applied to the slide, and tap water from different sources. Temperature coefficients have been determined to correct changes in ambient temperatures. The final handheld prototype is being developed based on these preliminary studies. This device could be of benefit for the early diagnosis of rejection episodes in recipients of bladder-drained pancreas grafts after hospital discharge.

Amylases↗
PubMed1988

The sequential use of a luteinizing hormone-releasing hormone (LH-RH) agonist and human menopausal gonadotropins to stimulate folliculogenesis in patients with resistant ovaries.

The diagnostic response toward the administration of a luteinizing hormone-releasing hormone (LH-RH) analogue in the early follicular phase has been used sequentially with conventional human menopausal gonadotropin (hMG) treatment in patients who had previously failed to develop multiple follicles in response to a combination of hMG and clomiphene citrate. Nine of fourteen patients (64%) showed an increase in the number of preovulatory follicles and five subjects reached oocyte recovery for the first time. Two patients (22%) became pregnant after in vitro fertilization and embryo transfer during the treatment cycle and had healthy babies. It is suggested that this treatment regimen may be advantageous in some patients with resistant ovaries.

Adult↗
PubMed1987

Interference in the measurement of red cell glycogen by glycogen from white cells.

An enzymatic method for determining red cell glycogen was developed and its recovery and precision ascertained. Initial red cell glycogen values in 24 healthy volunteers ranged from 11-60 micrograms/g haemoglobin which compares with 20-105 micrograms/g haemoglobin previously reported. More thorough removal of leucocytes suggested however that variations in the determined red cell glycogen were due to glycogen derived from leucocytes. In 34 red cell preparations with varying leucocyte numbers, the glycogen concentration correlated positively with leucocyte count (r = +0.81, p less than 0.001), whereas glycogen concentration showed poor correlation with red cell count (r = -0.30, 0.1 greater than p greater than 0.05). The results question the reported presence of glycogen in normal red cells and suggest that contamination by leucocytes has been responsible for the previously reported normal range.

Erythrocytes↗
PubMed1987

Studies on the measurement and pharmacodynamics of human follicle-stimulating hormone.

The levels of immunoreactive follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), cortisol, and estradiol (E2) have been determined in serial samples of peripheral plasma from four subjects during the continuous, subcutaneous administration of Buserelin (Hoechst [UK] Ltd., Hounslow, UK) (250 micrograms/day) and after the intramuscular injection of purified, urinary FSH (Metrodin, Serono Laboratories [UK] Ltd., Welwyn Garden City, UK) (150 IU). During Buserelin administration the geometric mean levels of FSH and LH as measured by immunoradiometric assay were reduced by 87% and 37%, respectively, when compared with the corresponding values for days 1 and 2 of the menstrual cycle. After the intramuscular injection of FSH, peak levels (from 3.4 to 6.2 IU/l) occurred in peripheral plasma between 6 and 18 hours later. The levels were significantly elevated after 72 hours (P less than 0.01, Student's paired t-test). There was no obvious effect of the drugs on the circadian rhythms of plasma PRL or cortisol, and no significant effect on the circulatory levels of LH or E2.

Adult↗
PubMed1987

A comparison of treatments with exogenous FSH to promote folliculogenesis in patients with quiescent ovaries due to the continued administration of an LH-RH agonist.

The circulating levels of plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH) and oestradiol (E2) have been determined in three groups of three subjects during the continuous, subcutaneous administration of an LH-RH agonist (250 micrograms/day) and after the intramuscular injection of urinary FSH (group I, 150 IU daily for 8 days, total 1200 IU; group II, 300 IU on alternate days for four injections, total 1200 IU; and group III, 150 IU on alternate days for four injections, total 600 IU). The level of circulating FSH in group I rose steadily from a geometric mean of 1.11 (pre-injection) to 8.76 U/l (at day 8), while the corresponding levels in groups II and III fluctuated according to the time and dose of the injected material. Twenty-four hours after the injection the mean level of FSH in group II was significantly higher (7.31 U/l) than the corresponding value for group I (2.79 U/l) or group III (3.48 U/l). Only those subjects in group II showed a resumption of folliculogenesis (leading, mean maximum follicular diameters of 16, 13 and 14 mm, respectively) and a corresponding increase in the concentration of plasma E2 (from 22, 43 and 103 to 906, 1477 and 2362 pmol/l, respectively).

Adult↗
PubMed1987

Determination of iron in cardiac and liver tissues by plasma emission spectroscopy.

A simple plasma emission spectroscopic method for the determination of iron in liver and cardiac tissue is described. Using this technique, iron was extracted quantitatively from liver tissue of mass 14.2 to 65.4 mg wet weight, and heart tissue of mass 5.9 to 27.4 mg wet weight. Iron added to liver as aqueous ferric nitrate was recovered in the range 93 to 108%. Reference ranges for liver and myocardial iron on post mortem tissue gave respectively mean values of 0.841 mg/g dry weight (Range 0.310 to 1.600, n = 37) and 0.340 mg/g dry weight (Range 0.290 to 0.470, n = 8). Data on patients with haemochromatosis and transfusion siderosis are also presented.

Aged↗
PubMed1984

Vaccine prophylaxis of abattoir-associated Q fever.

Q fever is an important cause of morbidity in Australian meatworkers; recently there have been sharp outbreaks of Q fever in abattoirs in several states. In an attempt to control Q fever by vaccination, 924 nonimmune volunteers at two South Australian abattoirs were inoculated with one dose of a purified, formalin-inactivated, Coxiella burneti, Henzerling strain, phase 1 vaccine. Some 56% of workers in one abattoir, and 64% in the other, seroconverted after vaccination. In the 18 months after vaccination, no Q fever occurred in fully vaccinated subjects, whereas there were 34 cases in 1349 unvaccinated workers. Transient local reactions were noted in most vaccinated subjects; only a few had mild general reactions. No cases of vaccine-enhanced disease were observed. Vaccination of susceptible individuals with a purified C burneti phase 1 vaccine appears to be safe and effective in preventing Q fever in the abattoir.

Abattoirs↗
PubMed1984

Headaches after childbirth.

71 women were examined daily for the presence of headache in their first post partum week. Post natal headache (PNH) occurred in 27, (39%) of the women and was most frequent on days 4-6 post partum. PNH was significantly associated with a previous or family history of migraine and pre-menstrual migraine. Although 83% of those with PNH had a migraine diathesis, they did not describe their headache as one of their usual migraines as it was considerably milder. Headaches were more frequent among multigravida but as rather more multigravida had a previous migraine diathesis this may reflect a sampling bias. PNH subjects had significantly more tension and depression suggesting that at least some PNH may be tension headache. Around 3 or 4 days post partum, women began to lose weight and the onset of headache often coincided with the start of this weight loss. 12 women with, and 12 without PNH took part in a metabolic study, and collected sequential 24 h urine samples from days 2-7 post partum. Potassium and oestrogen excretion were increased on day 3, and progesterone on days 3, 4 and 5. Differences in the excretion pattern of these hormones might reflect small changes in renal function and further work measuring plasma hormone levels could help to clarify this. PNH, like pre-menstrual headache and pill withdrawal headache may represent a further example of the triggering effect that a fall in sex hormone level has on the migraine diathesis.

Adolescent↗