Linear mitochondrial DNAs of yeasts: closed-loop structure of the termini and possible linear-circular conversion mechanisms.

The terminal structure of the linear mitochondrial DNA (mtDNA) from three yeast species has been examined. By enzymatic digestion, alkali denaturation, and sequencing of cloned termini, it was shown that in Pichia pijperi and P. jadinii, both termini of the linear mtDNA were made of a single-stranded loop covalently joining the two strands, as in the case of vaccinia virus DNA. The left and right loop sequences were in either of two orientations, suggesting the existence of a flip-flop inversion mechanism. Contiguous to the terminal loops, inverted terminal repeats were present. The mtDNA from Williopsis mrakii seems to have an analogous structure, although terminal loops could not be directly demonstrated. Electron microscopy revealed the presence, among linear molecules, of a small number of circular DNAs, mostly of monomer length. Linear and circular models of replication are considered, and possible conversion mechanisms between linear and circular forms are discussed. A flip-flop inversion mechanism between the inverted repeat sequences within a circular intermediate may be involved in the generation of the linear form of mtDNA.

Linear mitochondrial DNAs of yeasts: frequency of occurrence and general features.

In most yeast species, the mitochondrial DNA (mtDNA) has been reported to be a circular molecule. However, two cases of linear mtDNA with specific termini have previously been described. We examined the frequency of occurrence of linear forms of mtDNA among yeasts by pulsed-field gel electrophoresis. Among the 58 species from the genera Pichia and Williopsis that we examined, linear mtDNA was found with unexpectedly high frequency. Thirteen species contained a linear mtDNA, as confirmed by restriction mapping, and labeling, and electron microscopy. The mtDNAs from Pichia pijperi, Williopsis mrakii, and P. jadinii were studied in detail. In each case, the left and right terminal fragments shared homologous sequences. Between the terminal repeats, the order of mitochondrial genes was the same in all of the linear mtDNAs examined, despite a large variation of the genome size. This constancy of gene order is in contrast with the great variation of gene arrangement in circular mitochondrial genomes of yeasts. The coding sequences determined on several genes were highly homologous to those of the circular mtDNAs, suggesting that these two forms of mtDNA are not of distant origins.

"Alternative self-diploidization" or "ASD" homothallism in Saccharomyces cerevisiae: isolation of a mutant, nuclear-cytoplasmic interaction and endomitotic diploidization.

A mutant of Saccharomyces cerevisiae representing a novel life cycle, named "alternative self-diploidization" or "ASD" homothallism, was obtained fortuitously. In this life cycle, MAT alpha (or MATa) haplophase and MAT alpha/MAT alpha (or MATa/MATa) diplophase alternate. Germinated cells are haploid and mating. They soon become nonmating and sporogenous as they vegetatively grow. They sooner or later diploidize presumably via endomitosis. The diploid cells haploidize via normal meiosis. A single recessive nuclear mutation, named asd 1-1, is responsible for "ASD" homothallism. In the rho 0 cytoplasm, asd 1-1 cells mate even if at a low efficiency and fail to diploidize. Since pet mutations do not have such effects, we conclude that a certain mitochondrial function other than respiration is required for manifestation of "ASD" homothallism. That is, "ASD" homothallism is the result of some sort of nuclear-cytoplasmic interaction.

The inhibitory effect of 1,25-dihydroxyvitamin D3 on the secretion of platelet-activating factor acetylhydrolase by human decidual macrophages.

The effects of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and 25-hydroxyvitamin D3 on the secretion of a platelet-activating factor (PAF)-inactivating enzyme, PAF-acetylhydrolase (PAF-AH), by decidual macrophage populations were examined. 1,25-(OH)2D3 inhibited PAF-AH secretion by either decidual cells or flow cytometrically purified decidual macrophages. 25-Hydroxyvitamin D3 also decreased the enzyme secretion but at higher concentrations than those required for 1,25-(OH)2D3. The 1,25-(OH)2D3-induced inhibition was partially blocked by protein kinase C (PKC) inhibitors, sphingosine and 1-(5-isoquinolinesulfonyl)-2-metylpiperazine (H-7). An intracellular calcium channel blocker, bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid, tetra(acetoxymethyl)-ester (BAPTA/AM), also partially blocked the inhibition by 1,25-(OH)2D3, whereas extracellular calcium channel blockers, verapamil and nifedipine, failed to prevent the inhibition. H-7 and BAPTA/AM additively blocked the 1,25-(OH)2D3-induced inhibition. A PKC activator, 12-O-tetradecanoylphorbol 13-acetate, also decreased PAF-AH secretion. The decrease was abolished by sphingosine or H-7. It is suggested that 1,25-(OH)2D3 may increase the concentration of PAF in the decidua via its inhibitory effect on PAF-AH secretion by decidual macrophages and that the inhibitory action may be mediated by intracellular calcium and PKC-dependent signal transduction. PAF and 1,25-(OH)2D3 may, therefore, play a cooperative role in the regulation of PAF metabolism at the maternal-fetal interface.

The effect of pregnancy on cytochrome P4501A2, xanthine oxidase, and N-acetyltransferase activities in humans.

OBJECTIVE: Our objective was to evaluate the activity of cytochrome P4501A2 (CYP1A2), xanthine oxidase (XO), and N-acetyltransferase 2 (NAT2) from early to late pregnancy and after delivery. METHODS: Twelve women were studied on three occasions during pregnancy (early, 8-16 weeks' gestation; middle, 20-28 weeks' gestation; and late, 32-39 weeks' gestation) and about 1 month after delivery. Caffeine was used as a metabolic probe. After the women ingested a can or a bottle of caffeine-containing soft drink, urine samples were collected for 12 hours. The caffeine metabolites measured were 5-acetylamino-6-amino-3-methyluracil (AAMU), 1-methylxanthine (1X), 1-methyl-uric acid (1U), 1,7-dimethyl-uric acid (17U), and 1,7-dimethylxanthine (17X). The hepatic enzyme activities were estimated by the urinary caffeine metabolic ratios as follows: CYP1A2 = (AAMU + 1X + 1U)/17U; XO = 1U/(1X + 1U); NAT2 = AAMU/(AAMU + 1X + 1U). RESULTS: Statistically significant differences were found in CYP1A2 (P < .0001) and NAT2 (P < .01). The mean metabolic ratios for CYP1A2 during pregnancy (6.80, 5.18, and 4.97 for the early phase, middle phase, and late phase, respectively) were significantly lower than the ratio after delivery (10.39). The mean metabolic ratio for NAT2 in the early phase (0.57) was significantly lower than after delivery (0.66). There was no significant difference in metabolic ratios for XO during pregnancy and after delivery. CONCLUSION: The data demonstrate that pregnancy influences CYP1A2 and NAT2 activity. CYP1A2 activity decreases not only in late pregnancy but also in early and middle pregnancy.

Id1 expression is associated with histological grade and invasive behavior in endometrial carcinoma.

Basic helix-loop-helix (bHLH) DNA-binding proteins have been reported to regulate tissue-specific transcription of cellular differentiation within multiple cell lineages. The Id family of helix-loop-helix proteins does not possess a basic DNA-binding domain and functions as a negative regulator of bHLH proteins by forming high-affinity heterodimers with bHLH proteins. Id proteins were originally characterized as inhibitors of DNA binding and cell differentiation. Thus, overexpression of Id proteins correlates with cell proliferation and arrested differentiation in many cell lineages. To elucidate the involvement of Id1 in endometrial carcinogenesis, we analyzed serial frozen sections for Id1 protein expression in 20 cases of endometrial carcinoma and 20 cases of normal endometria by fluorescent immunohistochemistry. We analyzed the relationship between the percentages of Id1-stained cells and the patient's characteristics, including histological grade, clinical stage, presence of invasion to >1/2 myometrium, and clinical outcome. In normal endometria, Id1 was not detected in either the proliferative or the secretory phase. There was, however, abundant Id1 immunoreactivity in the endometrial carcinoma cells. Moreover, Id1 was strongly expressed in the inflammatory cells. Scoring on the basis of the percentage of positive cells indicated that Id1 expression is significantly associated with histological grade (P<0.05) and the presence of invasion to >1/2 myometrium (P<0.05). Our results demonstrate that increased Id1 expression in endometrial carcinoma correlates with the malignant potential of this tumor.

Polo-like kinase (PLK) expression in endometrial carcinoma.

Polo-like kinase (PLK) is a cell cycle-regulated, cyclin-independent serine/threonine protein kinase. Recent reports have shown a critical role for PLK during tumorigenesis. To explore whether PLK plays a general role as a tumor marker of endometrial carcinomas, we examined the expression of PLK mRNA and protein in endometrial carcinomas and normal endometrium, and analyzed the relationship between PLK protein expression and malignant potential. We found that PLK mRNA was expressed in all specimens from endometrial carcinoma patients using RT-PCR methods, although some specimens from normal endometria were negative. Immunohistochemically, most of the PLK was found in the cytoplasm (around the nucleus), and partly in the nucleus of endometrial carcinoma glands and also secreted tissues from endometrial carcinoma glands. PLK was expressed at the basement membrane of carcinoma glands and partly expressed in the head portion of papillary carcinoma tissues. There was a significant correlation between percentages of PLK-positive cells and histological grade of endometrial carcinoma (P<0.0001). However, the expression of proliferating cell nuclear antigen and Ki-67 was independent of PLK expression. Moreover, we noted that PLK is strongly expressed in invading carcinoma cells. PLK expression could reflect the degree of malignancy and proliferation in endometrial carcinoma. Thus, in addition to being of diagnostic value, modulation of PLK activity in the tumors by chemotherapeutic agents or gene therapy may prove to be of therapeutic value.

Expression of polo-like kinase in ovarian cancer is associated with histological grade and clinical stage.

Polo-like kinase (PLK), a cell cycle-regulated, cyclin-independent serine/threonine protein kinase, has been shown in recent reports to play a critical role during tumorigenesis. To investigate whether PLK plays a general role as a tumor marker of ovarian cancers, we examined the expression of PLK protein in ovarian cancers, and analyzed the relationship between PLK protein expression and histological grade. Immunohistochemically, the majority of PLK was found in the cytoplasm (around the nucleus), and a portion was found in the nucleus of ovarian cancer glands and also in the fluid secreted from these glands. PLK was expressed at the basement membrane of cancer glands and partly expressed in the head portion of papillary cancer tissues. A significant correlation was found between percentages of PLK-positive cells and histological grade of ovarian cancer (P<0.001). However, the expression of proliferating cell nuclear antigen, Ki-67, and cyclin B1 was independent of PLK expression. Taken together, these findings suggest that PLK expression may reflect the degree of malignancy rather than the degree of proliferation in ovarian cancer. Thus, in addition to being of diagnostic value, PLK activity in ovarian tumors may be modulated by chemotherapeutic agents or gene therapy to therapeutic effect.

Effect of intravenous or intra-amniotic injection of dehydroepiandrosterone sulphate on oestrogen levels in urine and serum in late pregnancy with live anencephalic foetuses.

Dehydroepiandrosterone sulphate (DHAS) was injected intravenously or intra-amniotically into eight volunteers carrying live anencephalic foetuses (including one microcephalic foetus). Urinary and unconjugated serum oestrone, oestradiol and oestriol were measured before and after DHAS administration. In seven pregnant women with live anencephalic foetuses the urinary excretion of oestriol was very low, and the ratio of oestriol to oestrone + oestradiol was much less than that during normal pregnancy. Increases of urinary oestrone and oestradiol but no significant change in the ratio of oestriol to oestrone + oestradiol were observed 24 h after i.v. administration of DHAS to five patients. In three patients, between 1 and 12 h after i.v. administration of DHAS (100-200 mg), the concentrations of serum oestrone, oestradiol and oestriol increased to 13-5, 6-8 and 3-1 times the control values, respectively. After injection of DHAS (200 mg) intra-amniotically into two patients, the urinary excretion of all three oestrogens increased much more on day 2 than on day 1, and the ratio of urinary oestriol to oestrone + oestradiol rose greatly. On the other hand, the concentrations of unconjugated serum oestrogens in these patients increased progressively between 1 and 12 h or more after DHAS administration, and the maximal level of serum oestriol was 9-8 times the control value while those of oestrone and oestradiol were 4-6 times and 5-0 times the control values, respectively. These results suggest that in late human pregnancy DHAS in the circulation of the mother is converted to oestriol largely via the phenolic pathway (DHAS leads to oestrone leads to oestriol), whereas DHAS circulating within the foeto-placental compartment is converted to oestriol via both the phenolic and the neutral intermediates.

Plasma levels of human chorionic somatomammotrophin, progesterone, unconjugated oestradiol and oestriol, and alpha-foetoprotein in patients with hydatidiform moles.

Human chorionic somatomammotrophin (HCS), progesterone, and unconjugated oestradiol and oestriol were measured in the plasma of 13 patients with intact hydatidiform moles from week 9 to 19 of pregnancy and in 89 normal women from week 5 to 20 of pregnancy. Plasma alpha-foetoprotein (AFP) was also measured in 9 out of 13 patients and in 23 of the normal women from week 13 to 20 of pregnancy. All the compounds were measured by radioimmunoassay. The plasma HCS concentration in 35 samples from 13 patients with hydatidiform moles ranged from 10 to 910 ng/ml; this was lower than that in normal pregnancy of corresponding duration in eight patients; within the normal range in four patients and high in one patient. The plasma progesterone concentration ranged from 17-5 to 79-2 ng/ml; it was higher than that in normal pregnancy in eight patients and within the normal range in five patients. The plasma unconjugated oestradiol concentration ranged from 1-82 to 8-10 ng/ml; it was higher than normal in six patients and within the normal range in seven patients. The plasma unconjugated oestriol concentration ranged from 0-168 to 1-37 ng/ml, the levels at 15-19 weeks of gestation being significantly lower than those in normal pregnancy at this time (P less than 0-005). Plasma AFP was not detectable in the nine patients (less than 10 ng/ml) whereas it ranged from 10 to 80 ng/ml in 18 out of 23 women in week 13-20 of normal pregnancy. The present results suggest that both plasma oestriol and AFP could be helpful in the diagnosis of hydatidiform mole at about 12-14 weeks though diagnosis could not be made with absolute certainty.

Production of interleukin (IL)-6 and IL-8 by a choriocarcinoma cell line, BeWo.

To clarify the biological and pathological features of choriocarcinoma, we evaluated the in vitro production of cytokines by a choriocarcinoma cell line, BeWo. We measured the concentration of interleukin (IL)-6 and IL-8 in the culture media of BeWo cells after stimulation with various modulatory agents of cytokine expression by enzyme-linked immunosorbent assays. Northern blot analysis was used to examine the expression of IL-6 and IL-8 mRNA in these cells. A weak expression of IL-6 and IL-8 was detected in unstimulated BeWo cells by both methods. IL-6 transcription and secretion were dose-dependently enhanced by stimulation with IL-1beta, tumour necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1 and 12-O-tetradecanoyl phorbol-13-acetate (TPA). Forskolin, lipopolysaccharide and interferon-gamma had no effect on these cytokines production. The TNF-alpha-induced secretion of IL-6 was inhibited by dexamethasone. The TPA-induced production of IL-6 was inhibited by 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine and sphyngosine, suggesting the involvement of a protein kinase C-dependent pathway. Levels of IL-8 mRNA and protein were also dose-dependently increased by stimulation with IL-1beta, TNF-alpha and TPA. In contrast to IL-6, the expression of IL-8 was not affected by TGF-beta1. It is suggested that, in addition to the production of steroidal and non-steroidal hormones, these cytokines may serve as part of a cytokine network that modulates the proliferation and angiogenesis of choriocarcinomas.

Removal of troponin C and desensitization of myosin B from ascidian smooth muscle by treatment with ethylene diamine tetraacetate.

On treatment with 10 mM EDTA at 30 degrees C, protein of 18,000 daltons was released from myofibrils, thin filaments and myosin B prepared from the smooth muscle of an ascidian, Halocynthia roretzi. This protein was purified from the EDTA extract of myofibrils by differential centrifugation, freeze-drying and gel-filtration. Based on its molecular weight, electrophoretic mobilities in the presence and absence of Ca2+ and other properties, it was identified as troponin C. By EDTA treatment, ascidian myosin B lost the Ca2+-sensitivity of Mg2+-ATPase, and EDTA-treated myosin B recovered the sensitivity by mixing with the EDTA extract of myosin B in the presence of Mg2+. Gel-electrophoretic patterns indicated that desensitization and resensitization of ascidian myosin B were accompanied by the removal and binding of troponin C. These results indicate that ascidian smooth muscle is regulated by a troponin-tropomyosin system, and desensitization induced by EDTA treatment is due to the removal of troponin C but not the release of the light chains of the myosin molecule. Based on these findings, we have established a simple method for the purification of troponin C from ascidian smooth muscle.

Vaginal fluid hCG levels for detecting premature rupture of membranes.

OBJECTIVE: To determine if the measurement of hCG levels in vaginal fluid is useful for the diagnosis of premature rupture of membranes (PROM). METHODS: After irrigating the posterior vaginal fornix with 3 mL of sterile saline and procuring vaginal washings, we measured hCG levels. Samples were analyzed from 188 normal pregnant women, 42, 61, and 85 during the first, second, and third trimesters, respectively. Levels of hCG were compared with those of 24 women with confirmed PROM. RESULTS: The median and 95% confidence intervals (CIs) of vaginal fluid hCG levels of normal pregnant women were 37.9 (1.9, 725.6), 9.5 (0.8, 95.8), and 6.3 (0.6, 62.2) mIU/mL during the first, second, and third trimesters, respectively. That of women with PROM was 420.6 (216.3, 918.3) mIU/mL. For the second trimester, sensitivity was 100%, specificity 91.8%, positive predictive value 82.8%, negative predictive value 100%, and accuracy 94.1%; and for the third trimester, sensitivity was 100%, specificity 96.5%, positive predictive value 88.9%, negative predictive value 100%, and accuracy 97.2%, using a threshold value of 50 mIU/mL. CONCLUSION: The hCG level in vaginal fluid is a useful marker of PROM during the second and third trimesters.

Can prenatal vitamin K1 (phylloquinone) supplementation replace prophylaxis at birth?

OBJECTIVE: To assess the effect of prenatal vitamin K1 on the coagulation status of newborns. METHODS: We measured noncarboxylated prothrombin and performed the Normotest in two groups of 5-day-old infants whose mothers were given oral vitamin K1, 10 mg/day for 2 weeks at least 10 days before delivery, or were untreated. RESULTS: Noncarboxylated prothrombin was found in one of 74 treated women and 13 of 186 controls, a nonsignificant difference. The mean (+/- standard deviation) Normotest value was 59.6 +/- 10.1% (range 38.9-84.4) for the treated group and 53.4 +/- 9.9% (range 16.3-89.9) for the controls, a statistically significant difference (P < .001). CONCLUSION: Based on the Normotest results, we suggest that vitamin K crosses the placenta and persists to activate the vitamin K-dependent coagulant factors until at least the fifth day of life. Thus, prenatal vitamin K1 administration may replace prophylaxis at birth.

Urinary estradiol-17-beta-glucuronide assay for gonadotropin therapy.

To investigate the possibility of using urinary estradiol-17 beta-glucuronide (E2-17G) measured by direct radioimmunoassay to monitor ovulation induction with human menopausal gonadotropin (hMG), serum estrogen and urinary E2-17G levels were determined daily by 21 women treated with hMG for a total of 32 treatment cycles. Urinary E2-17G was measured in 24-hour and overnight specimens. A significant correlation was found between serum estrogens (primarily estradiol) measured by radioimmunoassay without preceding chromatography and urinary E2-17G excretion measured at 24 hours and overnight. The correlation was not significantly improved by correcting the 24-hour and overnight urinary E2-17G excretion levels with creatinine measurements. Although there was significant correlation between serum estrogens and urinary E2-17G measured by direct radioimmunoassay, the urinary E2-17G concentrations observed when serum estrogens levels indicated preovulatory follicle maturation (ie, at serum estrogens levels between 500 and 1000 pg/ml) varied so much that a clinical decision to trigger or not to trigger ovulation with human chorionic gonadotropin could not be reached in each case. These data indicate that significant correlation is not the only prerequisite for a new method to replace a proved procedure. Further studies are required to determine the reliability of monitoring hMG therapy with direct E2-17G radioimmunoassays in overnight urine collections.

Amniotic fluid embolism and leukotrienes--the role of amniotic fluid surfactant in leukotriene production.

Surfactant rich lipid (lipid) was extracted from cell free 10,000 x g pellets of amniotic fluid. White blood cells (WBC) were isolated from human donors. 36 x 10(7) WBC and 5 g rabbit lung were incubated with pretreated lipid or dipalmitoyl lecithin (lecithin). Leukotrienes (LTs) were identified by high performance liquid chromatography (HPLC) and bioassay, and quantified by radioimmunoassay. Peaks of LTC4 and LTD4 on HPLC and guinea-pig ileum contraction could be identified in lipid and lecithin groups, but not in the control group. LTC4 production by lipid and lecithin groups was significantly higher than that by the control group. An involvement of amniotic fluid surfactant in leukotriene production is suggested.

Lecithins enhance leukotriene production from white cells.

36 x 10(7) WBC were isolated from 120 ml heparinized venous blood by 5% dextran T-500 sedimentation. 20 mg egg lecithin and 20 mg dipalmitoyl lecithin were respectively pretreated in 2 ml 0.15 M Tris buffer by vibration and sonication. WBC were incubated with the pretreated lecithins for 20 min. Leukotrienes (LTs) were identified by HPLC and bioassay, and quantified with an RIA Kit. Crude incubation medium of both lecithin groups caused guinea pig ileum contractions which were antagonized with FPL55712. Incubation media were partially purified with Bond elut C18. Purified samples of both lecithin groups showed LTC4 and LTD4 peaks on HPLC. LTC4 production (pg/10(7) WBC, M +/- SD) was 194.5 +/- 61.7 (n = 5) in control group, 348.9 +/- 95.4 (n = 6) in dipalmitoyl lecithin group, 543.8 +/- 105.6 (n = 6) in egg lecithin group and 105.62 +/- 63.2 (n = 6) in AA-861 + dipalmitoyl lecithin group. LTC4 production of both lecithin groups was significantly higher than that of control group (P less than 0.01 in dipalmitoyl lecithin group and P less than 0.001 in egg lecithin group). Both egg lecithin and dipalmitoyl lecithin enhanced LT production from WBC. LT production was suppressed in the presence of AA-861. The mechanism of the enhancement in LT production is unclear, but these lecithins are apparently not substrates because dipalmitoyl lecithin contains no arachidonic acid.

The effects of a 5-lipoxygenase inhibitor, AA-861, on PGI2-like substance production in guinea-pig lungs.

To determine the effects of AA-861 on PGI2 production in guinea-pig lungs, 3 g of guinea-pig lung was chopped in 4 ml of buffer (control group), in buffer with 4 micrograms/ml indomethacin (indomethacin group) and in buffer with 2.5 x 10(-5)M AA-861 (AA-861 group). The chopped lungs were incubated for 30 min. 250 microliters of incubation medium from each group was assessed before and after 3, 5, 10, 15, 20, 25 and 30 min of incubation. The incubation medium was centrifuged and the supernatant was tested for a PGI2-like substance (PGI2) by platelet aggregation inhibition. PGI2 was produced mainly during the initial 3-5 min of incubation and was decreased thereafter. PGI2 production was almost completely inhibited in the indomethacin group at all of the incubation times and was partially inhibited in the AA-861 group during the initial 3-5 minutes. Endogenous 5-lipoxygenase products generated in the early stages of incubation seem to be involved in PGI2 production in guinea-pig lungs.

Effect of endotoxin-induced reactive oxygen species on sperm motility.

OBJECTIVE: To define the mechanism of infection-induced damage of sperm. DESIGN: The effect of lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) on sperm motility and its modification by scavengers were investigated. SETTING: Research laboratory of a university hospital. PATIENT(S): Normozoospermic semen samples were obtained from 37 healthy volunteers. INTERVENTION(S): The sperms were incubated in the presence of LPS with or without scavengers. MAIN OUTCOME MEASURE(S): Sperm motility was evaluated by a sperm quality analyzer (SQAIIB). ROS formation in semen samples was measured by a Berthold luminometer (LB953). RESULT(S): Motility of spermatozoa was decreased in the LPS-treated samples compared with that in the control groups. ROS was significantly higher in the LPS-treated groups than in the control groups. The addition of ROS scavengers restored the motility index and suppressed ROS production in the LPS-treated semen samples. CONCLUSION(S): These data suggest that endotoxin-induced excessive production of ROS is responsible for the decrease in sperm motility and that antioxidant therapy may be a therapeutic option for infertile men with bacterial genital tract infection.

Platelet-activating factor-acetylhydrolase activity in follicular fluid of patients undergoing in vitro fertilization and embryo transfer.

OBJECTIVE: To examine the role of platelet-activating factor (PAF) metabolism in the periovulatory processes. DESIGN: The PAF-acetylhydrolase activity in the follicular fluid (FF) obtained in conjunction with IVF-ET procedure was assayed and its activity was related to oocyte maturation. The PAF-acetylhydrolase activity also was related to the concentration of various ovarian hormones. SETTING: All patients were managed and treated at Oita Medical University Hospital, Oita, Japan. PATIENTS: The study concerned 30 women between 28 and 36 years of age with tubal infertility. MAIN OUTCOME MEASURE: The activity of PAF-acetylhydrolase in FF was assayed as well as E2 and P. Oocyte maturation also was evaluated. RESULTS: Platelet-activating factor-acetylhydrolase activity was decreased significantly in the FFs of patients with a successful outcome of their pregnancies compared with the nonsuccessful group. Estradiol levels were negatively correlated with PAF-acetylhydrolase activities in the FFs. No correlation was found between the PAF-acetylhydrolase activity and P concentration in the FF. Significantly more mature and less immature oocytes were recovered in the group who subsequently became pregnant compared with the nonpregnant group. CONCLUSIONS: It is suggested that the decrease in PAF-acetylhydrolase activity may result in an increase of PAF in the FFs, which in turn may contribute to a successful pregnancy. The determination of PAF-acetylhydrolase activity in FF may serve as a prognostic marker for the evaluation of oocytes that are utilized in IVF-ET procedure.