Four zona pellucida glycoproteins are expressed in the human.

BACKGROUND: The zona pellucida (ZP) is an extracellular glycoprotein matrix which surrounds all mammalian oocytes. Recent data have shown the presence of four human zona genes (ZP1, ZP2, ZP3 and ZPB). The aim of the study was to determine if all four ZP proteins are expressed and present in the human. METHODS: cDNA derived from human oocytes were used to amplify by PCR the four ZP genes. In addition, isolated native human ZP were heat-solubilized, trypsin-digested and subjected to tandem mass spectrometry (MS/MS). RESULTS: All four genes were expressed and the respective proteins present in the human ZP. Moreover, a bioinformatics approach showed that the mouse ZPB gene, although present, is likely to encode a non-functional protein. CONCLUSIONS: Four ZP genes are expressed in human oocytes (ZP1, ZP2, ZP3 and ZPB) and preliminary data show that the four corresponding ZP proteins are present in the human ZP. Therefore, this is a fundamental difference with the mouse model

Blastocyst transfer for patients with multiple assisted reproduction treatment failures: preliminary experience.

This preliminary study reports the results obtained from a patient group in which blastocyst culture and transfer were performed, and discusses the advantages and disadvantages of introducing blastocyst transfer in a clinic. Twenty-six patients who had failed to achieve a pregnancy in previous in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatments were offered the choice of a fresh cycle with culture to the blastocyst stage. Of the 26 patients who elected to attempt blastocyst culture, 11 opted to have transfer on day 2 or day 3 due to low numbers of embryos. Of the 15 patients who proceeded to blastocyst culture, 46.2% of the embryos cultured reached the blastocyst stage or later and eight of the patients achieved a clinical pregnancy. More oocytes were collected in this patient group, hence the chances of obtaining blastocysts were higher. Offering blastocyst culture to patients with a reasonable chance of success who have had previous multiple assisted reproduction failures is an acceptable way of introducing blastocyst culture into practice.

Reducing the dose of gonadotrophin-releasing hormone agonist on starting ovarian stimulation: effect on ovarian response and in-vitro fertilization outcome.

The aim of this study was to examine if lowering the dose of gonadotrophin-releasing hormone agonist (GnRHa) on starting ovarian stimulation could be beneficial in in-vitro fertilization (IVF) programmes. A total of 64 normally ovulating patients entering an IVF programme were randomized to receive GnRHa (nafarelin acetate/Synarel) as an intranasal spray commencing in the midluteal phase, either at a dosage of 200 microg three times daily until the day of human chorionic gonadotrophin (HCG) administration, or to be reduced to 200 microg twice daily as ovarian stimulation was initiated. Patients in both groups were below 35 years with a body mass index below 30. All patients received three ampoules of Metrodin HP per day. Blood samples were taken on the day of HCG administration to measure luteinizing hormone (LH), oestradiol, and progesterone. LH and oestradiol were found to be significantly higher in the lower Synarel dose group. Our results show that reducing the GnRHa dose during ovarian stimulation in IVF might be beneficial in terms of significantly more oocytes recovered, and significantly greater number of embryos available for transfer and freezing, with no incidence of premature luteinization.

Transmyometrial embryo transfer after difficult immediate mock transcervical transfer.

OBJECTIVE: To evaluate the place of ultrasound-directed transvaginal transmyometrial ET in a protocol using both the transcervical and transmyometrial routes in a step-wise fashion. DESIGN: A prospective descriptive clinical study. SETTING: A university-based assisted conception unit. PATIENTS: Thirteen patients who had difficult or impossible mock transcervical ET immediately before the real transfer. INTERVENTION: Ultrasound-directed transvaginal transmyometrial ET. MAIN OUTCOME MEASURES: Pregnancy and clinical pregnancy. RESULTS: Four patients became pregnant, including three with clinical pregnancies. CONCLUSIONS: In cases in which transcervical ET isd difficult or impossible, transvaginal transmyometrial ET is a viable option. The use of mock transcervical ET immediately before the real transfer would identify patients needing transmyometrial ET.

Mock embryo transfer with a full bladder immediately before the real transfer for in-vitro fertilization treatment: the Birmingham experience of 113 cases.

The technique of embryo transfer can have a great impact on the outcome of in-vitro fertilization (IVF) treatment. Transcervical embryo transfer is a blind procedure and difficulty can unexpectedly arise. Many IVF programmes therefore perform a 'mock' embryo transfer prior to the treatment cycle to determine the most suitable catheter and technique for transfer. This, however, adds an extra separate procedure with time and cost implications. Moreover, as the uterus is mobile, its direction may vary on the day of the embryo transfer from what it was during the mock embryo transfer. Performing mock embryo transfer immediately before the real transfer would circumvent these problems. We report here on 113 embryo transfer procedures where a 'step-wise' mock embryo transfer protocol was performed with a full bladder immediately before the embryo transfer. The number of embryos transferred (mean +/- SD) was 2.6 +/- 0.67, the pregnancy rate per embryo transfer was 45.1%, and the intrauterine implantation rate per embryo transferred was 20.6%.

Do patients need to remain in bed following embryo transfer? The Birmingham experience of 103 in-vitro fertilization cycles with no bed rest following embryo transfer.

Since the early days of human in-vitro fertilization and embryo transfer, rest in bed for hours immediately following the transfer has been advocated and widely practised. However, there is no scientific validation for this practice which is both time-consuming for the patient and increases space occupancy in the hospital or clinic. We report here on a study of 103 in-vitro fertilization cycles with no bed rest in hospital following the embryo transfer. The mean number of embryos transferred was 2.7 (range 1-3) and the clinical pregnancy rate per embryo transfer procedure was 40%. These results suggest that bed rest is not necessary following embryo transfer.

Does resection enhance the response of the intestine to urogastrone-epidermal growth factor in the rat?

1. The objective of this study was to see whether another proliferative stimulus could modify the marked proliferative effect of human epidermal growth factor (urogastrone-epidermal growth factor, URO-EGF) on the gastrointestinal epithelium. 2. The response of the gastrointestinal tract to URO-EGF was investigated in rats maintained on total parenteral nutrition (TPN) with or without 75% small bowel resection. 3. Continuous infusion of 60 micrograms of recombinant beta-urogastrone/day per rat increased proliferation in the stomach by over four times (P less than 0.01), doubled proliferation in the small intestine (P less than 0.001) and increased it by four and a half times in the colon (P less than 0.001) in the control group. No significant effect of urogastrone was observed in the stomach of the resected groups, but proliferation was also increased in the small intestine by one and a half times (P less than 0.001) and by nearly four times in the colon (P less than 0.001). 4. Two-way analysis of variance showed that resection had a significant effect (P less than 0.01) on proliferation below the anastomosis and in the ileum. However, the response of the ileum was only half that observed in orally fed rats, which confirms the importance of 'luminal nutrition' in the response to resection. 5. Intestinal resection in the TPN rat was associated with a small rise in plasma enteroglucagon levels, suggesting that this hormone may be implicated in the adaptive response of the small intestine to resection.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of urogastrone (epidermal growth factor) on the intestinal epithelium.

Recombinant urogastrone (human epidermal growth factor) was infused into rats in which intestinal cell proliferation was reduced to a steady state basal level by feeding them intravenously. Urogastrone elevated the augmented metaphase index and weight of all sections of the gastrointestinal tract in a dose-related manner. Infusion of urogastrone at a dose which has a minimal effect on gastric acid secretion significantly increased crypt cell production and tissue weights throughout the gastrointestinal tract. Intravenous urogastrone was also effective in restoring cell proliferation after the intestine had become hypoproliferative. Urogastrone administered luminally had no significant effect on either intestinal weight, crypt cell production rate, or metaphase collection.

Intravenous but not intragastric urogastrone-EGF is trophic to the intestine of parenterally fed rats.

The effects of beta-urogastrone/human epidermal growth factor (URO-EGF) on intestinal epithelial cell proliferation were studied in rats in which intestinal cell proliferation had been reduced to a steady state basal level, by maintaining the rats on total parenteral nutrition. The accumulation of arrested metaphases over a two hour time period was determined in a dose response study. Increasing doses of URO-EGF progressively raised the two hour collection of metaphases and intestinal weights. Intravenous infusion of URO-EGF was also effective in restoring cell proliferation when it was infused after the intestine had become hypoproliferative. beta-urogastrone/human epidermal growth factor administered through an intragastric cannulae thrice daily had no significant effect on intestinal weight or crypt cell production rate or metaphase collection. It is proposed that one of the in vivo actions of urogastrone-epidermal growth factor is the maintenance of gastrointestinal growth and that this occurs through a systemic rather than a luminal mechanism.

Effects of an elemental diet, inert bulk and different types of dietary fibre on the response of the intestinal epithelium to refeeding in the rat and relationship to plasma gastrin, enteroglucagon, and PYY concentrations.

Refeeding starved rats with an elemental diet resulted in a marked increase in crypt cell production rate (CCPR) in the proximal small intestine but not in the distal regions of the gut. Little effect on CCPR was noted when inert bulk (kaolin) was added to the elemental diet. Addition of a poorly fermentable dietary fibre (purified wood cellulose) had little effect on intestinal epithelial cell proliferation except in the distal colon where it significantly increased CCPR. A more readily fermentable fibre (purified wheat bran) caused a large proliferative response in the proximal, mid, and distal colon and in the distal small intestine. A gel forming fibre only significantly stimulated proliferation in the distal colon; the rats in this group, however, did not eat all the food given. There was no significant correlation between CCPR and plasma gastrin concentrations, but plasma enteroglucagon concentrations were significantly correlated with CCPR in almost all the sites studied. Plasma PYY concentrations also showed some correlation with CCPR, especially in the colon. Thus while inert bulk cannot stimulate colonic epithelial cell proliferation fermentable fibre is capable of stimulating proliferation in the colon, and especially in the distal colon: it can also stimulate proliferation in the distal small intestine and it is likely that plasma enteroglucagon may have a role to play in this process.

Proliferative effects of 'fibre' on the intestinal epithelium: relationship to gastrin, enteroglucagon and PYY.

Refeeding starved rats with a fibre free 'elemental' diet increased crypt cell production rate (CCPR) in the proximal small intestine but not in the distal regions of the gut. Little effect on CCPR was seen when inert bulk (kaolin) was added to the 'elemental' diet. Addition of a poorly fermentable dietary 'fibre' (purified wood cellulose) had little effect on intestinal epithelial cell proliferation except in the distal colon where it significantly increased CCPR. A more readily fermentable 'fibre' (purified wheat bran) caused a large proliferative response in the proximal, mid and distal colon and in the distal small intestine. A gel forming 'fibre' also stimulated proliferation in the distal colon. There was no significant correlation between CCPR and plasma gastrin concentrations, but plasma enteroglucagon concentrations were significantly correlated with CCPR in almost all the sites studied. Plasma PYY concentrations also showed some correlation with CCPR, especially in the colon. Thus, whilst inert bulk cannot stimulate colonic epithelial cell proliferation, fermentable 'fibre' is capable of stimulating proliferation in the colon, and especially in the distal colon: it can also stimulate proliferation in the distal small intestine and it is likely that plasma enteroglucagon may have a role to play in this process.

Proliferative effects of urogastrone-EGF on the intestinal epithelium.

The effects of B-urogastrone/human epidermal growth factor on intestinal epithelial cell proliferation were studied in rats in which intestinal cell proliferation was reduced to a steady state basal level (by maintaining the rats on total parenteral nutrition). Increasing doses of urogastrone progressively raised the two hour collection of metaphases and intestinal weights. The crypt cell production rate was measured in animals maintained parenterally with or without urogastrone, and in rats fed a standard laboratory ration. Continuous infusion of 15 micrograms per rat per day of recombinant beta urogastrone (a dose which has a minimal effect on gastric acid secretion) significantly increased cell proliferation and intestinal tissue weights throughout the gastrointestinal tract. Intravenous infusion of urogastrone was also effective in restoring cell proliferation when it was infused after the intestine had become hypoproliferative. Urogastrone administered through an intragastric cannula thrice daily had no significant effect on either intestinal weight, crypt cell production rate, or metaphase collection.

Urogastrone-epidermal growth factor is trophic to the intestinal epithelium of parenterally fed rats.

The weight of the stomach, small intestine and colon and the mucosal crypt cell production rate of these tissues were significantly decreased after 10 days on an isocaloric TPN diet when compared to orally fed controls. Continuous infusion of recombinant beta urogastrone, at a dose below that needed to inhibit gastric acid secretion, largely prevented this decrease in crypt cell production rate and gastrointestinal tissue weights.