Low implantation rate after in-vitro fertilization in patients with hydrosalpinges diagnosed by ultrasonography

The purpose of this study was to assess whether patients with tubal infertility and a hydrosalpinx have a reduced implantation rate after in-vitro fertilization. The study included 741 patients who had 1190 consecutive oocyte aspirations. The presence or absence of hydrosalpinges was assessed by transvaginal ultrasonography on day 2 of all cycles. In 62 patients treated in 104 cycles a hydrosalpinx was diagnosed, whereas 493 patients treated in 813 cycles had no hydrosalpinx and eight patients treated in 16 cycles had uncertain hydrosalpinx. The results show that the presence of a hydrosalpinx is associated with a reduced pregnancy rate per aspiration (19.2 versus 32.6%; P < 0.01), reduced implantation rate (2.9 versus 10.3%, P < 0.0005), reduced delivery rate per aspiration (5.8 versus 20.9%, P < 0.0005), reduced delivery rate per embryo transfer (6.6 versus 22.8%, P < 0.0005) and increased early pregnancy loss (70 versus 36%, P < 0.005). Among 178 patients with unexplained infertility or other infertility factors treated with 257 aspirations the results were similar to those in patients with tubal infertility without a hydrosalpinx. In conclusion, the presence of a hydrosalpinx does not impair the number of embryos transferred but seems to impair the implantation process. We hypothesize that this may be due to leakage of fluid into the uterine cavity which may disturb the receptivity of the endometrium and/or the developing embryos.

[Intrauterine insemination with donor semen. Treatment of involuntary childlessness caused by male infertility]

Intrauterine insemination with cryopreserved donor semen was performed in 114 women in a total of menstrual 381 cycles during the period 1.2.1991 to 15.5.1993. Eighty-one pregnancies were recorded corresponding to a conception rate of 21% per insemination cycle. After ten cycles the probability of conception and expected delivery was respectively 96% and 86%. The results show that intrauterine insemination with donor semen is a good treatment for couples with male infertility. Ultrasonic measurement of the follicles and timing of hCG injection were used for optimal timing of intrauterine donor insemination. The quality of the semen used for insemination is important. It is recommended to inseminate with at least two million of spermatozoa where at least 20% have normal motility.

Vasoactive intestinal polypeptide and peptide histidine methionine. Presence in human follicular fluid and effects on DNA synthesis and steroid secretion in cultured human granulosa/lutein cells

Vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM) originate from the same precursor molecule, prepro VIP. In the present study we examined the concentrations of VIP and PHM in human follicular fluid and their effects on cultured human granulosa/lutein cells. Follicular fluid and cells were obtained from patients undergoing in-vitro fertilization for tubal infertility. The concentrations of VIP and PHM in pre-ovulatory human follicular fluid were measured radioimmunochemically. Granulosa/lutein cells isolated from follicular fluid were cultured under serum-free conditions with VIP and PHM in varying concentrations (0.1, 10, 1000 nmol/l). [3H]Thymidine incorporation in the cells and oestradiol as well as progesterone concentrations in the culture medium were measured. The mean (+/- SEM) concentrations of VIP and PHM were 6.8 +/- 0.1 and 7.7 +/- 0.8 pmol/l, respectively. VIP at a concentration of 10 nmol/l caused a significant increase in [3H]thymidine incorporation, and at 1000 nmol/l a significant increase in oestradiol secretion was observed. VIP had no effect on progesterone secretion. PHM at the concentrations tested did not influence any of the activities. We conclude that VIP and PHM are present in human preovulatory follicular fluid and that VIP stimulates DNA synthesis and oestradiol secretion in cultured human granulosa/lutein cells. This indicates that VIP and perhaps PHM participate in the local nervous regulation of human ovarian function.

[Heterotopic pregnancy after in vitro fertilization]

Until December 1991, 1171 pregnancies had been established in Denmark after in vitro fertilization and embryo transfer (IVF-ET). Thirteen of these pregnancies were heterotopic (1.1%). Three patients were asymptomatic, four patients presented with an acute abdomen, five had abdominal pain and only two patients had vaginal bleeding. In five cases the diagnosis of heterotopic pregnancy was made by ultrasound, while eight cases were diagnosed at the time of surgery. Eleven patients were treated in the first trimester, while two patients were treated at 23 and 38 weeks of gestation, respectively. In nine of the thirteen cases the intrauterine pregnancy resulted in term delivery. Heterotopic pregnancy occurred in 1% of pregnancies following IVF-ET. Abdominal pain was the predominant symptom, while vaginal bleeding was absent in the majority of women. In most cases removal of the ectopic gestation allowed the intrauterine pregnancy to proceed until term.

[Ovum donation. A review of and a suggestion to unified guidelines for treatment at public fertility clinics in Denmark]

The most common indication for oocyte donation is ovarian insufficiency due to premature menopause or resistant ovarian syndrome and ovarian dysgenesis with either normal or abnormal (e.g. Turner's syndrome) karyotype. In Denmark, oocyte donation must be anonymous, and the donors have to be other infertile patients undergoing in vitro fertilisation (IVF), treatment. It is suggested, that the National Health Service offers oocyte donation to hypergonadotropic women with ovarian insufficiency, as well as to a few other groups who fulfil the criteria for IVF treatment, but where this treatment cannot be completed. Oocyte donors must be less than 35 years old, physically and mentally healthy and without major genetic diseases in the family. The donor must be screened for HIV, hepatitis, syphilis, chlamydia and gonorrhoea. We propose that those patients who have more than six oocytes aspirated, allowing "surplus" oocytes to be donated. It is also proposed that the departmental order from the Ministry of Health be changed, so that normally fertile women are allowed to donate oocytes. Oocyte donation should be reported to a central authority.

[Fertilization in vitro. A review over the medical indications and suggestion to unified guidelines for public fertility clinics in Denmark]

Medical indications for in vitro fertilization and embryo transfer (IVF-ET) internationally and in Denmark are reviewed. Reports from large international centres document that tubal infertility, unexplained infertility, endometriosis and male infertility are equally good indications for IVF. Traditionally, tubal infertility has been the only medical indication qualifying for IVF treatment within the National Health Service in Denmark. Thus, in this country, couples with unexplained and male infertility and with endometriosis have to pay up to 25,000 D.Kr. per IVF-ET treatment in private fertility clinics. Since there is no scientific basis for this discrimination, it is urged that the present rules are changed, so that couples with unexplained and male infertility and endometriosis are also allowed IVF treatment free of charge in the public fertility clinics.

[Freezing of human embryos. A review of and a suggestion to unified guidelines for treatment at public fertility clinics in Denmark]

In Denmark, legislation has made cryopreservation of human oocytes and embryos possible since October 1992. The legislation is reviewed. Cryopreservation of embryos constitutes a significant improvement of infertility treatment. The number of oocyte pick-ups and the number of embryos transferred can be reduced without compromising the total likelihood of success of in-vitro fertilization (IVF) treatment. According to Danish law, frozen embryos can only be stored for one year. This limit will interfere with patient expectations in numerous cases, and the time limit should be expanded. Moreover, freezing of embryos should be allowed in connection with oocyte donation programmes.

Ant Communities in the Gulf Region of Australia Semiarid Tropics - Species Composition, Patterns of Organization, and Biogeography

The ant communities of nine sites near Lawn Hill (540 mm mean annual rainfall) in semi-arid north-western Queensland are documented, and compared with the known faunas of arid, semi-arid and seasonally arid sites elsewhere in Australia. The sites were surveyed primarily by pitfall trapping, during April (end of wet season) 1991, September (late dry season) 1991, and February (mid-wet season) 1992. A total of 111 ant species was recorded, with the most common being Iridomyrmex spp. and Rhytidoponera rufithorax. The richest genera were Melophorus (26 species), Monomorium (17), Iridomyrmex (16) and Camponotus (10) and Pheidole (10). The maj or functional groups were Dominant Dolichoderinae (Iridomyrmex spp.; 14% of the total number of species, 47% of the total number of ants in traps), Hot-climate specialists (mostly Melophorus spp.; 39%, 22%) and Generalised Myrmicinae (mostly Monomorium and Pheidole spp.; 20%, 11%). Multivariate analysis indicated that site differences in species composition were related primarily to landform, geology and soil type. Comparisons with other ant faunas show the Lawn Hill fauna to have closer affinities with those of the central arid zone than with those of high rainfall areas of the seasonal tropics. The arid-zone characteristics of the Lawn Hill fauna include a high proportion (38%) of Eyrean species, a high mean number of species per genus (6.5), and a very high combined representation of Iridomyrmex, Melophorus and Camponotus (45% of the total number of species, 69% of the total number of ants in traps).

Canopy Ant Communities in the Semiarid Mallee Region of North-Western Victoria

Ants were collected from the canopies of mallee eucalypts at Wyperfeld National Park in north-western Victoria by beating foliage on ten occasions from September 1979 to December 1980. The study was conducted at two adjacent sites: one that had been burnt by a wildfire during early 1977, and the other long unburnt. Both sites contained a mixture of three mallee eucalypt species: Eucalyptus dumosa, E. foecunda and E. incrassata. In contrast to the canopies of other eucalypt formations elsewhere in southern Australia, abundance and diversity of ants were very high. Ants represented 43-69% of all invertebrates, and a total of 44 ant species from 19 genera was collected. Iridomyrmex and Camponotus respectively contributed 10 and 11 species, and the most abundant ants were species of Iridomyrmex, Monomorium and Crematogaster. Ant composition was broadily similar at the two sites, and on different canopy species, although significant differences in abundance were apparent for some individual ant species. Except for tree-nesting Podomyrma adelaidae and Myrmecorhynchus sp. nr emeryi, the fauna was dominated by ground-nesting species, most of which appeared to forage on vegetation opportunistically. The unusually high abundance and diversity of the canopy ant fauna are attributed to the close proximity of the mallee canopy to the ground, coupled with an exceptionally rich ground ant fauna.

Intrauterine fertilization capsules--a clinical trial

Treatment of 26 women with tubal infertility was attempted using intrauterine capsules loaded with oocytes and spermatozoa. The stimulation protocol was as used for in vitro fertilization and embryo transfer and consisted of short-term use of Buserelin, human menopausal gonadotropin, and human chorionic gonadotropin. Oocytes were collected by ultrasonically guided transvaginal aspiration, and spermatozoa were prepared by swim-up technique. The gametes were placed in agar capsules 4 hr after oocyte collection, and the capsules were introduced to the uterine fundus using an insertion tube and piston from an intrauterine device. Six complete capsules and parts of two other capsules were expelled. None of the women became pregnant, compared with a pregnancy rate of 21% per aspiration following in vitro fertilization and embryo transfer during the same period.

Pulsatile gonadotropin secretion and basal prolactin levels during dopamine D-1 receptor stimulation in normal women

The effect of the specific dopamine D-1 receptor agonist Fenoldopam on pulsatile gonadotropin secretion and prolactin (PRL) secretion was investigated in normal women. The gonadotropin response to subsequent gonadotropin-releasing-hormone (GnRH) administration was also studied. Eight women received 8-hour infusions of either Fenoldopam (0.5 microgram/kg per minute) (Smith Kline and French, Harrow, United Kingdom) or placebo. After 7 hours of infusion, GnRH was given intravenously. The luteinizing hormone (LH) response to GnRH was significantly higher during Fenoldopam compared with placebo (LH; 13.1 +/- 9.0 versus 9.4 +/- 4.3 IU/L). Basal LH levels, pulse amplitude, and pulse frequency during Fenoldopam infusion were not different from placebo. Prolactin levels increased significantly during Fenoldopam (24 +/- 2 micrograms/L) compared with placebo (16 +/- 2). The results suggest that D-1 receptor stimulation does not affect pulsatile gonadotropin secretion but increases the pituitary responsiveness to GnRH. Additionally, dopamine and Fenoldopam have opposite effects on PRL secretion, the latter increasing PRL levels.

Effect of dopamine and a dopamine D-1 receptor agonist on pulsatile thyrotrophin secretion in normal women

The inhibitory effect of a pharmacological dose of dopamine and the specific dopamine D-1 receptor agonist fenoldopam on basal and pulsatile TSH secretion was investigated in normal women. The TSH response to fenoldopam and subsequent releasing hormone administration was also studied. Six women received placebo or dopamine infusion (4.0 micrograms/kg min) for 17 h. After 9 h, blood samples were collected every 10 min between 0800 and 1600 h for measurement of TSH. Eight women received 8-h (0900-1700 h) infusions of either fenoldopam (0.5 micrograms/kg min) or placebo. After 7 h of infusion 10 micrograms TRH, 5 micrograms GnRH and 25 micrograms CRF was given i.v. Blood samples were collected every 10 min. Dopamine infusion as well as fenoldopam infusion significantly reduced both mean basal TSH secretion and TSH pulse frequency compared with corresponding control infusions (P less than 0.05). However, while the effect on TSH pulsatility was comparable (P greater than 0.05), the percentage decrease in basal TSH levels after 16 h of dopamine infusion was 51 +/- 16% (mean +/- SD) and after 7 h of fenoldopam infusion 19 +/- 12% (P less than 0.05). Neither of the drugs affected TSH pulse amplitude and fenoldopam did not influence TRH-stimulated TSH release (P greater than 0.05). The results suggest that dopamine D-1 receptors are involved in modulation of TSH pulsatility probably at the hypothalamic level. It is argued that dopaminergic inhibition of basal TSH secretion and TSH pulsatility is predominantly regulated through dopamine D-2 receptors at the pituitary level, and through D-1 receptors at the hypothalamic level, respectively.

Effect of dopamine, dopamine D-1 and D-2 receptor modulation on ACTH and cortisol levels in normal men and women

The regulation of the hypothalamic-pituitary-adrenal axis by dopamine is not fully understood. Therefore, we have studied the effect of dopamine, metoclopramide, a D-2 receptor antagonist, and fenoldopam, a specific D-1 receptor agonist, on ACTH and cortisol levels in normal subjects. Normal women received 5-h infusions of either glucose (N = 6) or dopamine at rates of 0.04 (N = 6), 0.4 (N = 6) and 4.0 micrograms.kg-1.min-1 (N = 8). After 3 h, 10 mg metoclopramide was given iv. No intergroup differences regarding ACTH and cortisol levels were observed (p greater than 0.05). In a second study six women received dopamine (4.0 micrograms.kg-1.min-1) or glucose for 18 h. During the infusions cortisol and ACTH levels were similar on the two study days. Administration of metoclopramide (10 mg) after 17 h induced a significant increase in cortisol levels during dopamine infusion (p less than 0.05), whereas no effect was observed during placebo infusion. ACTH levels were unaffected by metoclopramide. In a third study, 9 normal women and 9 normal men received fenoldopam (0.5 micrograms.kg-1.min-) or placebo infusions for 3 h. In males, median ACTH and cortisol levels were significantly lower (p less than 0.05) during fenoldopam compared with placebo infusion. In contrast, fenoldopam did not affect ACTH and cortisol levels in normal women. The results suggest that the effect of dopamine D-1 receptor stimulation on ACTH and cortisol secretion is mainly at the hypothalamic level and that this effect is sex-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of fenoldopam, a dopamine D-1 receptor agonist, on pituitary, gonadal and thyroid hormone secretion

The influence of fenoldopam, a dopamine (DA) D-1 receptor agonist, on basal and GnRH/TRH stimulated PRL, GH, LH, TSH, testosterone and thyroid hormone secretion was studied in nine normal men. All men received 4-h infusions of either 0.9% saline or fenoldopam at an infusion rate of 0.5 microgram/kg min, 12-16 ml/h, adjusted according to weight. After 3 h of infusion, 50 micrograms GnRH and 100 micrograms TRH was given i.v. Blood samples were collected every 15 min from 1 h before to 1 h after the infusion for a total of 6 h for measurements of PRL, LH, FSH, GH, TSH, testosterone, T4 and T3. The median PRL concentration increased significantly (P less than 0.01) to 128%, range 87-287, of preinfusion levels, compared to the decline during control infusion (85%, 78-114). Basal TSH levels declined significantly to 71% (60-91) during fenoldopam compared with 82% (65-115) during control infusion (P less than 0.05). Basal LH, FSH, GH and thyroid hormones were similar during fenoldopam and control infusions (P greater than 0.05). The LH response to GnRH/TRH was significantly (P less than 0.02) increased by fenoldopam infusion. Basal and stimulated testosterone concentration was lower during fenoldopam (P less than 0.01) infusion compared with control. Other hormones were similar after GnRH/TRH stimulation during fenoldopam and saline infusions. These results suggest that DA D-1 receptors are involved in the modulation of pituitary hormone secretion. We suggest that the effect of fenoldopam on PRL and TSH is mainly at the hypothalamic level. Regarding the effect on LH concentrations, an additional direct effect of fenoldopam on testosterone regulation can not be excluded.

Cortisol secretion in patients with normoprolactinemic amenorrhea

Patients with functional amenorrhea have raised central dopaminergic activity and opioid-mediated GnRH inhibition leading to inhibition of hypothalamic-pituitary-ovarian function. In the present study, basal serum cortisol and ACTH levels were measured in normoprolactinemic amenorrheic patients with (N = 14) and without (N = 7) insulin-dependent diabetes mellitus. Basal serum cortisol levels was significantly (P less than 0.01) elevated in patients with normoprolactinemic amenorrhea compared with normal women. Basal serum cortisol was significantly (P less than 0.02) elevated in amenorrheic diabetic patients compared with menstruating diabetic women. In the amenorrheic groups both cortisol and ACTH levels increased significantly (P less than 0.01) after dopamine D-2 receptor blockade, whereas no hormonal changes occurred in the control groups. It is concluded that patients with normoprolactinemic amenorrhea have elevated basal serum cortisol, the reason probably being hypersecretion of corticotropin-releasing hormone. Secondly that dopaminergic blockade with metoclopramide stimulates ACTH and cortisol secretion in patients presumed to have raised dopaminergic activity.

Dopaminergic regulation of gonadotropin levels and pulsatility in normal women

This study was done to define the concentration of dopamine (DA) that inhibits gonadotropin secretion and to study the effect of DA D-2 receptor blockade during the infusions. Normal women received 5-hour infusions of either glucose (n = 14) or DA at rates of 0.04 (n = 6), 0.4 (n = 6), and 4.0 micrograms/kg X minute (n = 9). After 3 hours, metoclopramide (MTC) was administered. Mean serum luteinizing hormone (LH) concentration declined during 0.4 (P less than 0.01) and 4.0 micrograms/kg X minute (P less than 0.05) infusion doses of DA. This effect of DA was not consistently (P greater than 0.05) antagonized by MTC. Six women received DA (4.0 micrograms/kg X minute) or glucose for 18 hours. After 17 hours, MTC was given. Blood samples were collected every 10 minutes during the last 8 hours. No significant effect on LH pulse frequency and pulse amplitude was observed (P greater than 0.05). A marked (P less than 0.01) rise in LH occurred after MTC administration. The authors conclude that (1) physiologic doses of DA may inhibit LH secretion with only little, if any, effect on the pulsatile release; and (2) low-affinity DA receptors responsive to DA D-2 antagonists may regulate LH secretion.

Insect Inhabitants of Fruits of Leptospermum, Eucalyptus and Casuarina in Southeastern Australia

Insects dissected and reared from the fruits of four species of Leptospermum (myrsinoides, juniperinum, laevigatum and lanigerum), three species of Eucalyptus (baxteri, obliqua and willisil] and four species of Casuarina (pusilla, stricta, littoralis and paludosa), collected from 18 sites over four seasons at Wilsons Promontory in south-eastern Australia, are enumerated and discussed. Fruits of all species supported abundant and diverse assemblages of seed-eating insects and associated parasites. The distribution of phytophagous insects was related to host-plant phylogeny and, in particular, to fruit morphology. When fruit morphology was relatively constant within a host-plant genus (Eucalyptus and Casuarina), that genus supported a characteristic suite of seed-eating insects; when it varied markedly between species (Leptospermum), so did the composition of seed-eating insects. Insect species often occurred widely within a host genus, but were never recorded from different host genera. An extensive radiation of seed-eating Anobiidae (Dryophilodes spp.) in myrtaceous capsules parallels that of weevils known in fruits of Acacia. The major seed-eating insects recorded in each host taxon were: (a) in Eucalyptus spp. (all fruits woody and persistent capsules), Dryophilodes sp. B (Coleoptera : Anobiidae) and chalcidoid wasps, mostly Megastigmus sp. (Torymidae) and Eurytoma sp. (Eurytomidae); (b) in Casuarina spp. (all fruits woody and persistent 'cones'), chalcidoid wasps, mostly Bootanelleus sp. (Torymidae), and unidentified cosmopterigid moths; (c) in Leptospermum juniperinum and L. lanigerum (woody and persistent capsules), Dryophilodes spp. C and D, and unidentified cosmopterigid moths; (d) in L. laevigatum (semi-fleshy and semi-persistent capsules), Dryophilodes sp. E and an unidentified cecidomyiid fly; (e) in L. myrsinoides (fleshy and ephemeral capsules), an unidentified weevil and unidentified carposinid moth.

Prolonged dopamine receptor blockade in normoprolactinemic amenorrhea: a double-blind placebo study

Patients with functional amenorrhea may have a raised central dopaminergic activity, leading to inhibition of pituitary-ovarian function. In a double-blind placebo trial, ten patients with amenorrhea received metoclopramide (MTC) orally in daily doses from 20 to 7.5 mg in a sequential form for 10 weeks. Six patients received placebo. Serum levels for luteinizing hormone (P less than 0.02), follicle-stimulating hormone (P less than 0.05), and prolactin (P less than 0.001) increased significantly during MTC administration, and no (P greater than 0.05) hormonal changes occurred in the placebo group. Six patients observed vaginal bleedings during MTC administration but without postovulatory progesterone levels. Dopamine receptor blockade may activate the hypothalamic-pituitary axis of amenorrheic patients, although an ovulatory response is not achieved.

Increased dopaminergic activity inhibits basal and metoclopramide-stimulated prolactin and thyrotropin secretion

The influence of physiological to pharmacological doses of dopamine (DA) on basal and metoclopramide (MTC)-stimulated PRL and TSH secretion was studied in 11 regularly menstruating women between days 3 and 8 of the cycle. In groups of 6, the women received 5-h infusions of either 5% glucose or DA in a solution of 5% glucose at a rate of 12-16 ml/h, adjusted according to weight. Infusion rates of DA were 0.04 microgram/kg . min (low), 0.4 microgram/kg . min (medium), and 4.0 micrograms/kg . min (high). After 3 h of infusion, 10 mg MTC were given iv. Blood samples were collected every 15 min from 1 h before to 2 h after the infusion, for a total of 8 h, for measurements of PRL and TSH. The mean serum PRL concentrations declined significantly (P less than 0.05) during DA infusions to nadir values of 62 +/- 5% (+/- SEM; low), 43 +/- 3% (medium), and 43 +/- 6% (high) of the basal levels, whereas basal TSH levels declined significantly, to 64 +/- 5% of basal levels (P less than 0.05), during both the medium and high dose DA infusions. On paired comparisons, the hormone responses to MTC were lower (P less than 0.05) during the infusion of high dose DA (PRL, 2286 +/- 495% vs. 891 +/- 328%; TSH, 100 +/- 43% vs. 60 +/- 15%), but were not changed when MTC was given during the low and medium doses of DA. A rebound phenomenon was found for PRL (P less than 0.05) after the medium and high doses of DA and for TSH (P less than 0.05) after the high dose. These results indicate that doses of DA considered physiological inhibit PRL and TSH secretion and larger doses inhibit their responses to the DA antagonist MTC.

Diversity, Seasonality and Community Organization of Ants at Adjacent Heath and Woodland Sites in Southeastern Australia

Adjacent heath and woodland sites at Wilsons Promontory in Victoria support at least 50 species of ants, with the most abundant being Rhytidoponera victoriae, Iridomyrmex spp. (nitidiceps group), Notoncus hickmani, Aphaenogaster longiceps, Camponotus ?intrepidus and Plagiolepis sp. Total numbers of individuals and species in the woodland were twice that in the heath; this was probably caused by the greater structural complexity of vegetation there, which increased the availability of nesting and foraging sites, the level of insolation of the ground, and possibly also food supply. Total ant activity followed seasonal cycles which correlated with changes in temperature and probably also food supply, and, within these constraints, was regulated by prevailing weather conditions. Individual species displayed distinctive foraging schedules which possibly play an important role in species coexistence. Community organization is analysed according to a scheme derived from studies of ants in arid Australia, where taxa are classified according to their physical requirements and their relationships with dominant species. Although the major species in the present study were separated by differences in body size, food type, and time of foraging, interspecific competition appears to be less important than it is in arid regions. At both sites, opportunistic species (Rhytidoponera) predominated, cryptic species (those associated with soil and litter, such as Plagiolepis sp. and Solenopsis sp.) were abundant, and Iridomyrmex appeared to have a relatively weak influence on the abundance of other ants. This contrasts with the situation in arid regions, where species of Iridomyrmex are extremely important, and opportunistic and cryptic species are often rare or absent.

Prolactin and glucose tolerance in normal and gestational diabetic pregnancy

The relationship between the deterioration of glucose tolerance and plasma prolactin (PRL) levels was investigated in 15 normal pregnant women and in 15 women with gestational diabetes mellitus. Oral glucose tolerance tests were performed in late pregnancy and postpartum, and the insulin, glucagon, and PRL responses were measured. In late pregnancy the gestational diabetics revealed significantly elevated fasting glucose levels compared with the normal pregnant women and after the glucose challenge their insulin responses were significantly diminished and the suppression of glucagon less pronounced. These differences in glucose metabolism were markedly reduced early postpartum. There was no difference in basal PRL concentrations between the two groups neither in pregnancy nor postpartum. The PRL levels were not altered during the oral glucose tolerance tests and no correlation between the deterioration of glucose tolerance and the PRL concentrations could be demonstrated in either group. These results indicate that abnormal PRL levels are not of pathophysiologic importance for the development of gestational diabetes mellitus.