It is expected that the majority of developed follicles contain a competent and mature oocyte at the time of oocyte retrieval. However, different size of follicles are generally observed and most of the follicles need to be aspirated. The aim of this study was to assess the impact of stimulation with gonadotropins on follicular development, fertilization, implantation, chemical and clinical pregnancy rates. Retrospective study. Statistical analysis was performed using Levene's Test for Equality of Variances. Ovarian stimulation was performed under a GnRH analog (SUPREFACT, Berry Technologies Inc.) down regulation utilizing a long, short or micro-flare protocol with recombinant FSH (Gonal F, Serono) and LH (Luvesis, Serono) or human menopausal gonadotrophin (Pergonal, Serono), dose adjusted according to body mass index. During the ovarian stimulation regimen, the patients underwent transvaginal ultrasonographic evaluation of endometrial thickness and measurement of follicular number and size. Retrived oocytes were inseminated either by classical IVF or by ICSI. The results are given in Table 1 and 2. The proportion of large follicles in the group (ovary with <18 follicles) are significantly higher than that in the group (ovary with ≥ 18 follicles), while the proportions of small follicles in the group (<18) are significantly lower than that in the group (≥ 18). There were no significant differences in fertilization and chemical pregnancy rates between two groups with ≥ or < 18 follicles in the ovary on the day of HCG administration. However, the clinical pregnancy and implantation rates in the group (<18) were significantly higher than those in the group (≥ 18), respectively.Tabled 1 Tabled 1 Our findings show that excessive ovarian stimulation can decrease the survival of embryos at later stages after transfer. Techniques that avoid excessive follicular recruitement, such as using insulin sensitizing agent to reduce the basal follicular count in polycystic ovary in insulin-resistant patients, oral contraceptive for a few months prior to cycle initiation, or better gonadotrophin dose adjustment will have to be evaluated.

The aim of this study was to examine the effect of partial cumulus removal on the fertilization and the day 3 embryo quality. Results indicated that fertilization and grade (G) 4/3 embryo (86.7% and 61.4%) rates in the large oocyte–cumulus complex (OCC, ≥2 mm) were significantly greater compared with the small OCC (<2 mm) (73.1% and 42.0%). Removal of cumulus cells decreased the fertilization rate and subsequent embryo quality. The cumulus cells of OCCs should be excised as little as possible at the time of blood removal.

OBJECTIVE:To provide standards for the diagnosis and treatment of patients with hydatidiform mole and gestational trophoblastic tumours (GTT).OPTIONS:Prognostic factors useful for treatment decisions in GTT are defined with patients classified as low-, medium-, and high-risk groups.OUTCOMES:Improved mortality and morbidity.EVIDENCE:Evidence was gathered using Medline for relevant studies and articles from 1980 to 2001 with specific reference to diagnosis, treatment options, and outcomes. The quality of evidence of Recommendations has been described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam.RECOMMENDATIONS:1. Suction curettage is the preferred method of evacuation of the hydatidiform mole (III-C). Post-operative surveillance with hCG assays is essential (II-3B). 2. Low-risk patients with both non-metastatic and metastatic disease should be treated with single-agent chemotherapy, either methotrexate or dactinomycin (II-3B). 3. Medium-risk patients should usually be treated with multi-agent chemotherapy, either MAC or EMA (III-C); single-agent chemotherapy may also be used (III-C). 4. High-risk patients should be treated with multi-agent chemotherapy EMA/CO, with selective use of surgery and radiotherapy (II-3B). Salvage chemotherapy with EP/EMA and surgery should be employed in resistant disease (III-C). 5. Placental site trophoblastic tumour that is non-metastatic should be treated with hysterectomy (III-C). Metastatic disease should be treated with chemotherapy, most commonly EMA/CO (III-C).6. Women should be advised to avoid pregnancy until hCG levels have been normal for six months following evacuation of a molar pregnancy and for one year following chemotherapy for gestational trophoblastic tumour. The combined oral contraceptive pill is safe for use by women with GTT (III-C).VALIDATION:These guidelines have been reviewed and approved by the Policy and Practice Guidelines Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC), the Gynaecologic Oncologists of Canada (GOC), the Society of Canadian Colposcopists (SCC), and by Executive and Council of the SOGC.SPONSOR:The Society of Obstetricians and Gynaecologists of Canada.

OBJECTIVE To provide standards for the diagnosis and treatment of patients with hydatidiform mole and gestational trophoblastic tumours (GTT). OPTIONS Prognostic factors useful for treatment decisions in GTT are defined with patients classified as low-, medium-, and high-risk groups. OUTCOMES Improved mortality and morbidity. EVIDENCE Evidence was gathered using Medline for relevant studies and articles from 1980 to 2001 with specific reference to diagnosis, treatment options, and outcomes. The quality of evidence of Recommendations has been described using the Evaluation of Evidence criteria outlined in the Report of the Canadian Task Force on the Periodic Health Exam. RECOMMENDATIONS 1. Suction curettage is the preferred method of evacuation of the hydatidiform mole (III-C). Post-operative surveillance with hCG assays is essential (II-3B). 2. Low-risk patients with both non-metastatic and metastatic disease should be treated with single-agent chemotherapy, either methotrexate or dactinomycin (II-3B). 3. Medium-risk patients should usually be treated with multi-agent chemotherapy, either MAC or EMA (III-C); single-agent chemotherapy may also be used (III-C). 4. High-risk patients should be treated with multi-agent chemotherapy EMA/CO, with selective use of surgery and radiotherapy (II-3B). Salvage chemotherapy with EP/EMA and surgery should be employed in resistant disease (III-C). 5. Placental site trophoblastic tumour that is non-metastatic should be treated with hysterectomy (III-C). Metastatic disease should be treated with chemotherapy, most commonly EMA/CO (III-C).6. Women should be advised to avoid pregnancy until hCG levels have been normal for six months following evacuation of a molar pregnancy and for one year following chemotherapy for gestational trophoblastic tumour. The combined oral contraceptive pill is safe for use by women with GTT (III-C). VALIDATION These guidelines have been reviewed and approved by the Policy and Practice Guidelines Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC), the Gynaecologic Oncologists of Canada (GOC), the Society of Canadian Colposcopists (SCC), and by Executive and Council of the SOGC. SPONSOR The Society of Obstetricians and Gynaecologists of Canada.

The interactions of Ni2+ ion with calf thymus DNA has been studied in water at metal/DNA phosphate mole ratios ranging from 0.0125 to 6 using Raman spectroscopy. The weighted difference spectra method has been applied to analyze the data. It has been established that Ni2+ ion coordinates mainly at N7 centers of guanine (G) and adenine (A) of DNA at GG, AA and GA sequence places. At the same time the Ni2+ shows outer-sphere interaction, via water molecules, with phosphate groups of DNA.

We have studied by Raman spectroscopy the thermal behavior of associated polyguanylic acid [poly(G)] and polyguanylic–polycytidylic acid [poly(G) · poly(C)] in self-pressurized aqueous solutions contained in sealed capillary tubes. The associated polynucleotides were found to be very resistant to heat, but evidence of thermal degradation was observed after melting of the helical structures. The cooperative melting transition of the four-stranded complex of poly(G) was located at 141°C in 0.5M KCl, 135°C in 0.5M NaCl, 129°C in 0.5M LiCl, 123°C in 0.1M tetramethylammonium perchlorate, and 105°C in 0.1M tetraethylammonium bromide solutions. The transition was observed at 130°C in poly(G) · poly(C) (in 0.5M NaCl). The results in this case show that a four-stranded poly(G) complex is formed following the melting of the double helix. © 1999 John Wiley & Sons, Inc. Biopoly 49: 21–28, 1999

We studied by infrared and Raman spectroscopy the interaction of calf thymus DNA with various types of silica particles, ranging in size from 7 nm to 60 μm. Preliminary experiments with different samples showed that substantial variations can take place in the 1000–1100 cm−1 region of the attenuated total reflection (ATR) spectrum of silica, where a strong band due to a stretching vibration of the Si-O groups occurs. The position and intensity of this band were found to be dependent on several parameters, such as the size distribution of the solid particles, their proximity to the surface of the ATR crystal, and their degree of packing after sedimentation from the aqueous suspension. Changes observed in the spectra of aqueous solutions of DNA interacting with silica particles are explained by a shift of the main silica band in the mixtures. This interpretation differs from that of a previous study, where important intensity variations of the DNA bands at 1086 and 1053 cm−1 were explained by the formation of hydrogen bonds between the silanol groups of silica and the phosphate groups of DNA. Raman spectra of aqueous solutions of DNA mixed with fumed quartz particles of an average size of 0.007 μm showed but a minor change in intensity (ca. 5%) of the DNA symmetric phosphate band, which supports the conclusion reached in our infrared study. © 1997 John Wiley & Sons, Inc. Biospectroscopy 3: 299–306, 1997

We have studied by Raman and ir spectroscopy the metastable complex formed by the self-association of polyinosinic acid in aqueous solution. The complex is easily prepared by quickly cooling to ca. 0 degrees C a warm solution of the polyribonucleotide to which a small amount of rubidium salt has been added. Upon heating, this metastable form melts cooperatively near 13 degrees C, well below the dissociation temperature of a stable four-stranded complex, which occurs at 47 degrees C in the same conditions. The presence of several components in the stretching-mode region of the carbonyl groups in the vibrational spectra of the metastable complex suggests that it also has a parallel four-stranded structure. The difference in structure between the two forms is believed to be caused by the presence of fewer metal ions in the central channel of the metastable complex, in agreement with conclusions reached in previous investigations. The Raman spectra further show that the ribose units in the metastable form have a C3'-endo conformation, in contrast with the stable form, for which we have previously suggested a mixed C2'-endo/C3'-endo conformation.

We have studied by Raman and ir spectroscopy the structure of self‐associated polyinosinic acid and polyguanylic acid in aqueous solution. The results are consistent with the formation of a four‐stranded complex, which melts cooperatively near 60°C in the case of poly (I) in the presence of K + ions. The conformation of the ribose in both systems is mixed C2′‐ endo /C3′‐ endo , giving a structure that is intermediate between the extremes proposed previously from x‐ray diffraction studies. Characteristic Raman bands for the C2′‐ endo ribose conformation in polyribonucleotides are identified. The four‐stranded structure of poly (I) appears to be very flexible, with ≈15% of the tetrameric segments being disrupted and ≈30% of the ribose units adopting a disordered conformation prior to melting. This disordering process increases to ≈75% above the melting transition, with the remaining ≈25% of the ribose units keeping an ordered C2′‐ endo or C3′‐ endo conformation. © 1994 John Wiley & Sons, Inc.

The various steps needed for the addition of a CCD multichannel detector to a commercial Raman spectrometer are described. Options in the choice of the components required by this transformation are presented and the necessary corrections needed to transform raw spectra obtained in this manner into a more conventional format are discussed. The advantages and limitations of this type of detection are evaluated by comparison with the conventional dispersive method of data recording using a photomultiplier detection system.

Raman spectroscopy was used to study the interaction of various monovalent, divalent and trivalent metal cations with pyridine and maleimide in aqueous solution. The results show that transition-metal ions interact extensively with the nitrogen donor in pyridine. With maleimide, metal binding by the nitrogen atom with displacement of the proton occurs with ions such as Hg2+, Ni2+ and Zn2+. Other ions such as Cu2+, La3+ and Mg2+ cause the deprotonation of maleimide and interact with the resulting enolate anion. Ag+ and Cd2+ ions share both modes of interaction. Relevant conclusions from this study are extended to the special case of metal binding by double-stranded DNA.

We have studied, using Raman and infrared spectroscopy, the interaction of various monovalent, divalent, and trivalent metal cations with the [Formula: see text] group of diethyl phosphate in aqueous solution, at metal: phosphate ratios ranging from 1:40 to 6:1. The results show that the metal cations interact with the phosphate groups in various ways and to different extents. Spectral characteristics for some specific types of interactions are presented, namely, for direct metal binding by one of the oxygen atoms in the [Formula: see text] group, the formation of water-separated ion pairs, and non-specific electrostatic interactions.

The Raman spectra of highly concentrated solutions of 5'-GMP at neutral and acid pH were recorded in order to better characterize the structure of the self-aggregates formed in these solutions and their melting behavior. Vibrational coupling of the C = O stretching vibrations in tetrameric units at neutral pH is shown to yield a characteristics pattern of two Raman bands at ca. 1730 and 1680 cm-1 (1708 and 1664 cm-1 in D2O), and an iractive mode at 1678 cm-1 in D2O. From the intensity of the 1730-cm-1 band, proportional to tetramer concentration, and that at 1485 cm-1, which reflects the stacking of the bases, the thermal stability of the self-associates formed at neutral pH is shown to be higher for stacked tetramers. At acid pH, the melting of the helical aggregates responsible for the formation of a gel is preceded by the freeing of the hydrogen-bonded phosphate groups, accompanied by a change of conformation from C3'-endo to C2'-endo in some of the associated ribose units. Previous spectroscopic results suggesting the formation of tetramers as an intermediate step in the melting of the gel were not reproduced in this study.

A stoichiometric complex of formula maleic acid•2H2O•18-crown-6 has been obtained from maleic acid and the macrocyclic polyether 18-crown-6. Crystals of this complex have been shown by X-ray diffraction crystallography to belong to the Cc space group of the monoclinic system. The acid molecules in the adduct are linked to each other through a water molecule, giving infinite [-acid-H2O-]n chains. They are also linked to the crown ether via water molecules. The infrared and Raman spectra of the complex are presented and compared to those of crystalline maleic acid. Keywords: maleic acid/18-crown-6, structure, X-ray, spectra.

The interaction of Mg 2+ , Ca 2+ , Zn 2 , and Cd 2+ with calf thymus DNA has been investigated by Raman spectroscopy. These spectra reveal that all of these ions, and particularly Zn 2+ , bind to phosphate groups of DNA, causing a slight structural change in the polynucleotide at very small metal: DNA(P) concentration ratio ( ca. 1 : 30). This results in increased base‐stacking interactions, with negligible change of the B conformation of DNA. Contrary to Zn 2+ and Cd 2+ , which interact extensively with the nucleic bases (particularly at the N7 position of guanine), the alkaline‐earth metal ions are bound almost exclusively to the phosphate groups. The affinity of both the Zn 2+ and Cd 2+ ions for G‐C base pairs is comparable, but the Cd 2+ ions interact more extensively with A · T pairs than Zn 2+ ions. Interstrand cross‐linking through the N3 atom of cytosine is suggested in the presence of Zn 2+ , but not Cd 2+ .

The interaction of calf-thymus DNA with Cu(II) and Pb(II) ions has been investigated in H2O and D2O solutions at physiological pH, using laser Raman spectroscopy. The results confirm the destabilizing effect of Cu2+ ions, which are shown to bind strongly to the guanine and cytidine bases, perturbing the A-T base pairs and disrupting the double-helical structure of DNA, whose conformation is markedly altered by these interactions. Earlier claims that Pb2+ ions destabilize DNA are not supported by the present study. These ions are found to interact only weakly with the nucleic bases, binding to the N7 position of the guanine bases and also interacting with the A-T pairs. Both types of ions are found to interact with the charged phosphate groups of DNA, although these sites are preferred over the nucleic bases by Pb2+ ions.