Demonstration of enhanced nutrient removal at two full-scale SBR plants.

The efficacy of sequencing batch reactors (SBRs) to provide high levels of biological nutrient removal has been extensively demonstrated around the world. Environmental Solutions International (ESI) has now constructed over 20 full-scale SBR plants and has confirmed that nutrient removal is enhanced via the process of simultaneous nitrification and denitrification. Over 18 months of operational data from two plants, operating in distinctly different catchments, processing an average of between 2,000 and 2,500 m3/d of wastewater, has clearly shown the efficacy and robustness of the ESI SBR-BNR process. Median effluent total nitrogen and total phosphorus values of 3 mg/L and <0.6 mg/L, respectively, were demonstrated over the 18-month period. This high level of nutrient removal is attributed to the design of the bio-selector which maximises carbon storage for the subsequent denitrification reactions, the effective aeration control which ensures no over-aeration during the air-on cycle as well as the level of operational control provided at these two plants.

Effects of bradykinin receptor agonists, and captopril and thiorphan in ferret isolated trachea: evidence for bradykinin generation in vitro.

Bradykinin B2 receptor agonists, but not a B1 receptor agonist, were potent spasmogens of ferret isolated trachea. Bradykinin-induced contractions were unaffected by several pharmacological agents, indicating a direct effect on airway smooth muscle B2 receptors. Captopril plus thiorphan caused contractions in approximately 70% of preparations that were abolished by B2 receptor antagonists, but not by B1 receptor antagonist. Thus, ferret tracheal tissues appear capable of releasing and degrading kinins in vitro. Inhibition of peptide degradation with captopril and thiorphan may allow the endogenous kinins to accumulate in concentrations sufficient to elicit tracheal contraction via activation of B2 receptors.

ADP-ribosylation is involved in the integration of foreign DNA into the mammalian cell genome.

The most commonly used DNA transfection method, which employs the calcium phosphate co-precipitation of the donor DNA, involves several discrete steps (1,2). These include the uptake of the donor DNA by the recipient cells, the transport of the DNA to the nucleus, transient expression prior to integration into the host cell genome, concatenation and integration of the transfected DNA into the host cell genome and finally the stable expression of the integrated genes (2,3). Both the concatenation and the integration of the donor DNA into the host genome involve the formation and ligation of DNA strand-breaks. In the present study we demonstrate that the nuclear enzyme, adenosine diphosphoribosyl transferase (ADPRT, E.C. 2.4.2.30), which is dependent on the presence of DNA strand breaks for its activity (4,5) and necessary for the efficient ligation of DNA strand-breaks in eukaryotic cells (4,6), is required for the integration of donor DNA into the host genome. However, ADPRT activity does not influence the uptake of DNA into the cell, its episomal maintenance or replication, nor its expression either before or after integration into the host genome. These observations strongly suggest the involvement of ADPRT activity in eukaryotic DNA recombination events.

The effect of transferring pronuclear embryos on pregnancy outcome after in vitro fertilization.

In a prospective clinical trial the pregnancy rate in patients matched for infertility status, degree of hyperstimulation, and number of oocytes recovered was unaffected by whether embryos were transferred while still pronuclear (day 1) or after they had undergone cleavage (day 2). The pregnancy rates per transfer were 27% and 22%, respectively, for the two transfer times. Unlike results of a previous study, no difference was detected in the outcome of pregnancies from the two groups.

Special uses of a gas chromatograph-mass spectrometer in endocrinology.

Based on the isotope dilution principle, and using deuterium-labelled steroids as tracers combined with GC-MS analysis, clinically acceptable procedures for the measurement of daily urinary production rates (UPR's) and metabolic clearance rates (MCR's), of hormonal steroids, have been developed. In clinical tests, using progesterone and androstenedione as models the UPR's and MCR's obtained compared favourably with values obtained using radioisotope-labelled tracers. The heavy isotope procedure proved, however, to be superior to the radioisotope methods in accuracy, speed and patient safety.

The effect of clomid induced superovulation on human follicular and luteal function for extracorporeal fertilization and embryo transfer.

The administration of clomiphene citrate (Clomid) 150 mg/day from days 5-9 of the menstrual cycle to spontaneously ovulatory women in order to induce adequate multiple follicular development followed by timed laparoscopic aspiration of mature oocytes does not appear to impair luteal phase length or the steroid pattern of oestradiol-17 beta (E2) or progesterone (P) production as reflected by their peripheral blood concentrations. In Clomid stimulated cycles where preovular oocyte pickup (OPU) and embryo transfer (ET) occurred but no recognizable pregnancy resulted, the cycle length was 30.0 (s.e.m. = 0.3) days, the follicular phase length was 15.6 (s.e.m. = 0.3) days and the luteal phase length was 14.4 (s.e.m. = 0.3) days, which did not differ from a group of women having spontaneous ovular cycles. Following Clomid stimulation the dominant follicle was similar in size to the pre-ovulatory follicle in spontaneous uniovular cycles, but the second, third, fourth and fifth order follicles were significantly larger (P less than 0.0001). The ultimate test of luteal competence was the successful implantation of 11 concepti in 7 women (4 sets of twins) from 49 laparoscopies (14%) or 33 embryo transfers (21%). Comparisons between conceptual and non-conceptual embryo transfers following identical Clomid regimes showed no difference between plasma E2 concentrations at the time of hCG administration or the start of an endogenous LH rise; follicle volume, follicular fluid E2, P and testosterone concentrations were also not different. However, there was a trend for follicular P to be higher in the non-conceptual group indicating that advanced luteinization may hinder successful implantation. The follicular fluid androstenedione (A4) concentration was significantly lower in the conceptual group and the total androgen concentration (A4 + T) was also lower which was indicative of active aromatase activity in these follicles. It was concluded from this study that there was no indication to give exogenous hormonal support to the luteal phase, provided there was both optimal follicular growth and steroidogenic function following Clomid stimulation and that exogenous hCG was administered very close to the expected rise of LH. This observation was supported by the finding that timing of OPU based on a knowledge of the start of the LH surge was associated with a higher pregnancy rate than when hCG was administered and indicates that the endogenous mid-cycle events may permit superior maturation of the oocyte and/or permit better synchronization of endometrial maturation for implantation.

Applications of heavy isotope tracers to clinical studies: progesterone urinary production rate determination in the menstrual cycle and pregnancy.

A method for the in vivo determination of progesterone production rate using progesterone labeled with deuterium as the tracer and gas chromatography-mass spectrometry for assessing isotope dilution in a urinary metabolite is described. By measuring the ratio of labeled to unlabeled free progesterone in a 24-h urine sample, the problem of identifying a unique metabolite appears to have been avoided. Median progesterone production rates on day 7 of the follicular phase and day 7 of the luteal phase were 3.5 mumol/24 h and 72.6 mumol/24 h, respectively. Where repeated determinations were performed through the luteal phase in two nonconceptual cycles, the familiar midluteal plateau of progesterone production was noted. The MCR of progesterone calculated from luteal phase data was 2051 1/24 h (SD, 275 1/24 h). When determined in pregnancy, progesterone production varied from 250 mumol/24 h at 6 weeks in a singleton pregnancy, to 1565 mumol/24 h at 35 weeks in a triplet pregnancy. Repeated determinations before term in a twin pregnancy detected no evidence of decreasing progesterone production before labor. The value of urinary pregnanediol and plasma progesterone to indirectly monitor progesterone production were confirmed.

Human luteal phase function following oocyte aspiration from the immediately preovular graafian follicle of spontaneous ovular cycles.

Human luteal phase function as evaluated by peripheral venous blood steroid levels does not appear to be impaired following the aspiration of follicular fluid together with a cumulus enclosed oocyte and a number of granulosal cells from the immediate preovular follicle in women having otherwise spontaneous ovular cycles. The day to day levels of luteinising hormone, oestradiol-17 beta, 17 alpha-hydroxy-progesterone, progesterone and basal temperatures in 14 women who had their preovular follicle aspirated were compared with a control group of 28 spontaneously ovulating women. It was concluded that a carefully performed single aspiration of the contents of a preovular follicle, for the purpose of extra-corporeal fertilisation of the mature oocyte, did not lead to impaired steroid function of the subsequent corpus luteum, although the prolactin levels were increased due to the effects of the relaxant anaesthetic and/or the laparoscopic procedure. A safe and simple laparoscopic procedure is also described, which is particularly suitable for women with a likelihood of extensive pelvic adhesions.

Endocrine profiles and fertility status of human menstrual cycles of varying follicular phase length.

Assessment of the relationship between ovarian endocrine function and follicular phase length was made in 48 patients (51 cycles) with spontaneous ovular cycles of varying length. On the basis of follicular phase length when measured from the first day of menstruation to, and including, the day of the luteinizing hormone (LH) peak, cycles were grouped into short (less than 21 days), medium (12 to 16 days), and long (more than 6 days). Daily serum LH, androstenedione, 17 beta-estradiol, progesterone, and 17 alpha-hydroxyprogesterone concentrations were determined in the periovular period. The overall pattern of serum steroid concentrations in medium and long cycles was similar to that previously described for normal women. However, cycles with a short follicular phase had lower mean concentrations of androstenedione and estradiol. In order to assess the fertility potential of cycles with follicular phases of varying length, the prior 265 cycles of 92 consecutive patients who conceived with artificial insemination by donor (AID) were studied. In all cases, insemination occurred on day 0 and day + 1 with respect to the LH peak, and all cycles were assumed to have equal fertility potential. Statistical analysis revealed no significant difference in fertility potential among cycles with follicular phases of differing length.

Semen pathology, consistency and relationship to FSH in males attending an infertility service.

PIP: A simple classification of the usual microscopic features of seman analysis was used to separate the seminal findings of 330 male patients of infertile unions attending the infertility service in order to demonstrate the spectrum of pathology present. Plasma FSH was also measured in 261 subjects. Normal semen findings were present in 31% of the subjects, and azoospermic men constituted 20% of the group. The most common abnormality underlying the remaining males was severely reduced semen density (or= 15 million sperm/ml) which was found in 24% of the men (79). In only 1/2 of the men with density defects, were there additional defects of motility and/or morphology. A specific defective pattern of motility in the presence of normal morphology was found in 14% of the subjects and only about 1/2 of such men had an additional defect of sperm density. A small percentage (2%) of men had defects of morphology and motility without a density defect and 1% of the subjects demonstrated an isolated morphological abnormality. The exercises served to correct attention to the exact pathology of semen and to focus attention on the possible different underlying causes of the defects seen. Using the classification, a 2nd group of 144 men from a similar source, but who provided 2 semen samples at varying time intervals, allowed both the effect of time and the consistency of semen findings to be investigated. About 1/3 of samples were found to retain their original classification on repeat analysis, a further 1/3 had relatively small changes, and the remainder varied markedly. The time interval between analyses was not an important determinant of change. Elevation of plasma gonadotropins were principally found in association with the gross defects of sperm density and not with defects of motility or morphology.^ieng

Predicting the luteinizing hormone surge: relationship between the duration of the follicular and luteal phases and the length of the human menstrual cycle.

Determination of blood serum levels of luteinizing hormone (LH) are used to detect the day of the midcycle surge. This information, collected over several menstrual cycles of numerous women, is used to derive mathematical expressions relating the day of the surge to the length of the cycle. The equations are subsequently employed to predict the most likely day of the LH surge, and hence the time of ovulation, solely from knowledge of the average length and variability of a woman's cycles, without the need for determinations of LH. A convenient table is provided for making this prediction.

Optimal features of basal body temperature recordings associated with conceptional cycles.

Oral basal body temperature (BBT) recordings of 46 women that conceived by donor insemination and who had midcycle monitoring of luteinising hormone (LH) were analysed to establish features associated with an optimal cycle. All cycles exhibited a biphasic temperature shift associated with the follicular (mean + SD, 36.5 degrees C +/- 0.22) and luteal phases (36.8 degrees C +/- 0.19). Whilst a mean body temperature rise occurred on Day +1 when all cycles were analysed, individual patterns were seen at ovulation including no change or a decrease in BBT between Day 0 and Day +1. The BBT of the postovulatory phase was stable and only 4.5% of the 644 observations made showed a change of more than 0.2 degrees C from day to day. It was concluded that the BBT charting has limitations when used to recognize the day of ovulation, and that some variable patterns of the early luteal phase are consistent with conception. Finally, optimal luteal phases demonstrated remarkable stability.

PIP: Oral BBT (basal body temperature) recordings were made for 46 women who conceived by donor insemination. The BBT records were analyzed with conceptional cycles during which the time of ovulation was identified by assays of luteinizing hormone (LH). All cycles exhibited biphasic temperature shifts, with a definite rise following ovulation. The BBT nadir during the periovulatory period was identifiable. BBT postovulatory was stable. However, while the mean rise in temperature occurred on Day +1 for all cycles, there were individual variations including no change or a decreased BBT. It was concluded that neither the nadir nor the rise in BBT was clear enough to provide a reliable guide to ovulation detection when measured against accepted endocrinological markers.

The influence of insemination timing and semen characteristics on the efficiency of a donor insemination program.

The analysis of accumulated data from conceptional and nonconceptional ovulatory menstrual cycles of patients undertaking artificial donor insemination has allowed some observations to be made on the practical aspects which may influence the efficiency of the program. The evidence suggests that with the use of preserved semen, accurate timing of insemination is essential, and that days 0 and +1 with respect to the luteinizing hormone surge appear to be advantageous as compared with closely related days. When the numbers of motile spermatozoa which were inseminated over a critical 4-day interval were analyzed, the results also suggested that improved conception rates occurred when larger numbers of active spermatozoa were used. A comparison was made between those patients who had been inseminated on a single occasion and those inseminated on more than one occasion during the periovulatory period. The results obtained from those cycles inseminated on a single occasion were inferior to those obtained from cycles inseminated more than once. Finally, some limited comparison is drawn between the established insemination programs of bovine husbandry and the relatively inefficient human experience. One explanation may lie in the wider spectrum of donor semen desirable for the human programs.