Subtle Rise Research Articles

Numerical Study on the Impact of the Richardson Number on Convection in an Enclosure, with Moving Sidewalls for Three Aspect Ratios: A = 1, 2 and 0.5

Using mathematical models, this research investigation seeks to explore how varying aspect ratios and the Richardson number impact the mixing effectiveness, fluid flow velocity, and heat transfer characteristics in a rectangle-shaped space where cooling occurs along the sides and warm with a steady temperature exists throughout the 80% of the bottom section's center. Discretizing the governing equations through the finite volume approach, we solved them iteratively using the Tri-diagonal Matrix Algorithm, where pressure-velocity coupling was successfully implemented via the SIMPLER procedure. Innovative approaches for convection and diffusion terms involved employing a power-law difference scheme alongside a central differential scheme. In various simulations with specified parameters (Re = 100, Pr = 0.71), we visualized results in forms like streamlines, isothermal lines, and temperature/velocity profiles, along with local and average Nusselt numbers. We observe five unique structure formations during flow behavior by analyzing how Richardson numbers impact heat transmission within a specific geometric configuration (enclosure size A = 1). A change in aspect ratio leads to improved control over fluid movement while minimizing structural distortion. A subtle rise in heat transmission emerged as the average Nusselt number and Richardson number intersection strengthened force convection's domination while experiencing significant escalation under conditions conductive to natural convection. Decreasing the aspect ratio increased heat transfer efficiency when the Richardson number rose.

‘Panda diplomacy’ and the subtle rise of a Chinese language ecology in Qatar

ABSTRACT Over the past two decades, the Chinese language has emerged as a global language. Gulf Cooperation Council countries, such as Bahrain, Saudi Arabia, and the United Arab Emirates, have integrated Chinese language into their educational systems and established Confucius Institutes to promote Chinese language and culture. In Qatar, interest in Chinese language education has risen, though not as pronounced as its neighbouring countries. This article, grounded in a Critical Cultural Political Economy of Education (CCPEE) approach, provides a comprehensive overview of Chinese language and education policy in Qatar, utilising a mix of primary and secondary sources, and insights from the second author’s role as a Chinese language coordinator in Qatar. The article examines cultural, political, and economic aspects related to Qatar-China ties and the Chinese community in Qatar, the role of China during the World Cup, Chinese language in the linguistic landscape, Chinese language education policies, and the state of a Confucious Institute in Qatar. Finally, it offers some implications in terms of the future of Chinese language education in the country and some fruitful directions for further research.

Effect of Sound Genre on Emotional Responses for Adults With and Without Hearing Loss.

Adults with permanent hearing loss exhibit a reduced range of valence ratings in response to nonspeech sounds; however, the degree to which sound genre might affect such ratings is unclear. The purpose of this study was to determine if ratings of valence covary with sound genre (e.g., social communication, technology, music), or only expected valence (pleasant, neutral, unpleasant). As part of larger study protocols, participants rated valence and arousal in response to nonspeech sounds. For this study, data were reanalyzed by assigning sounds to unidimensional genres and evaluating relationships between hearing loss, age, and gender and ratings of valence. In total, results from 120 adults with normal hearing (M = 46.3 years, SD = 17.7, 33 males and 87 females) and 74 adults with hearing loss (M = 66.1 years, SD = 6.1, 46 males and 28 females) were included. Principal component analysis confirmed valence ratings loaded onto eight unidimensional factors: positive and negative social communication, positive and negative technology, music, animal, activities, and human body noises. Regression analysis revealed listeners with hearing loss rated some genres as less extreme (less pleasant/less unpleasant) than peers with better hearing, with the relationship between hearing loss and valence ratings being similar across genres within an expected valence category. In terms of demographic factors, female gender was associated with less pleasant ratings of negative social communication, positive and negative technology, activities, and human body noises, while increasing age was related to a subtle rise in valence ratings across all genres. Taken together, these results confirm and extend previous findings that hearing loss is related to a reduced range of valence ratings and suggest that this effect is mediated by expected sound valence, rather than sound genre.

Assessing the impact of hybrid teaching on students’ academic performance via multilevel propensity score-based techniques

This study employs multilevel propensity score techniques in an innovative analysis pipeline to assess the impact of hybrid teaching – a blend of face-to-face and online learning – on student performance within engineering programs at Politecnico di Milano implemented in response to Covid-19 pandemic. Analyzing students’ credits earned and grade point average, the investigation compares outcomes of students engaged in hybrid teaching against those solely in face-to-face instruction preceding the Covid-19 waves. Tailored multilevel models for earned credits and grade point averages are fitted onto meticulously constructed dataframes, minimizing potential biases stemming from variables such as gender, age, previous instruction, admission scores, and student origins across the two groups. Accounting for program variations in the methodology, our findings suggest marginal overall disparities in student performance, indicating, on average, a subtle rise in earned credits and a slight decrease in grade point averages for those exposed to hybrid teaching. Multilevel models reveal significant program-specific variations, offering valuable insights into the effectiveness of hybrid teaching in diverse educational contexts.

Sociodemographic Determinants and Types of Employment in Tanzania: Evidence from Integrated Labour Force Survey Data

This study scrutinises the link between sociodemographic factors and types of employment in Tanzania, leveraging data from the 2020-2021 Integrated Labour Force Survey collected by the Tanzania National Bureau of Statistics. Age, gender, education, and geographical area (rural or urban) are analysed for their influence on employment outcomes. The Integrated Labour Force Survey dataset, offering a national representative sample, forms the foundation for this research, facilitating a comprehensive investigation of employment types and sociodemographic characteristics. Two analytical techniques are employed – cross-tabulation analysis and the Chi-Square test of independence – allowing for exploring employment distribution across sociodemographic categories and the significance of the observed relationships. A key finding is the predominance of self-employment across all education levels, ages, gender and regions, with a subtle rise in wage employment correlating with higher education. Rural areas predominantly rely on self-employment, indicating their economic reliance on agriculture and small businesses. Urban areas show increased wage employment, indicating a wider array of job opportunities. Gender disparities are evident, with self-employment slightly more common among men while women engage more in unpaid work, reflecting traditional gender roles. Age-related analysis reveals a tendency for self-employment to increase, suggesting older individuals shift towards entrepreneurship, while unpaid work is more common among the younger population. Although the study design identifies associations, not causality, it offers more profound insights into the intricate relationship between sociodemographic characteristics and employment types in the Tanzanian context. This research enriches our understanding of Tanzania’s employment landscape, underlining the importance of sociodemographic determinants in shaping types of employment in the population.

Serum Progesterone Levels on the Day of Human Chorionic Gonadotrophin Trigger, and its effects on the Outcome of In Vitro Fertilization, and Embryo Transfer: A Two-Center Study

Abstract Introduction: Gonadotrophin-releasing hormone analogs were expected to make preovulatory progesterone (P4) elevation rare during in vitro fertilization (IVF) cycles, but despite its widespread use, subtle rise in P4 levels on the day of ovulation trigger has a documented prevalence of 5%–38%. The effect of preovulatory progesterone levels on IVF outcomes is still controversial and published data from West Africa is sparse. Materials and Methods: This was a prospective observational study of 107 women who underwent IVF in both Garki and Nisa hospitals in Abuja, Nigeria. A serum sample was obtained from participants on the day of human chorionic gonadotrophin administration for a single determination of progesterone level. Oocytes retrieved, biochemical pregnancy, and clinical pregnancy were the primary outcomes. Results: The mean P4 on human chorionic gonadotrophin (hCG) trigger day was 2.07 ± 0.24 ng/mL and 48 (44.9%) had P4 > 1.5 ng/mL. There was no relationship between P4, and the number of oocytes retrieved but implantation, biochemical pregnancy, and clinical pregnancy were significantly diminished when P4 >1.5 and <1 ng/mL: biochemical pregnancy (27.3% vs. 61.5% vs. 14.6%, χ2 = 17.896; P < 0.0001), clinical pregnancy (24.2% vs. 50.0% vs. 14.6%, χ2 = 11.041; P = 0.004). Conclusion: Pregnancy rates are diminished when P4 on hCG trigger day is elevated.

Sulfone "Geländer" Helices: Revealing Unexpected Parameters Controlling the Enantiomerization Process.

The two sulfonyl-bridged Geländer helices 1a and 2a are obtained by oxidation of the corresponding sulfide bridged precursors 1b and 2b. Both Geländer structures are fully characterized by NMR, high-resolution mass spectrometry, and optical spectroscopies. X-ray diffraction with a single crystal of 2a provides its solid-state structure. Both Geländer helices 1a and 2a are separated into enantiomers, and their racemizations are monitored by circular dichroism. For 1a, consisting of two equally sized macrocycles, a substantial increase in the enantiomerization barrier is observed upon going from the sulfide to the sulfone, and only a subtle rise is detected for the constitutional isomer 2a with two macrocycles of different size during the same transformation. This results not only in 1a with the highest configurational stability in the series of hitherto investigated Geländer structures but also challenges the so far hypothesized correlations between bridging structures and the Gibbs free energy of enantiomerization. The simulation of the enantiomerization process in the macrocyclic subunits suggests the proximity of the endotopic hydrogens as parameter responsible for the heights of the enantiomerization barrier.

Double diabetes: the cardiovascular implications of combining type 1 with type 2 diabetes

Double diabetes: the cardiovascular implications of combining type 1 with type 2 diabetes

Maternal 27-hydroxycholesterol concentrations during the course of pregnancy and in pregnancy pathologies

BackgroundThe oxysterol 27-hydroxycholesterol (27-OHC) plays an important role in the regulation of cholesterol homeostasis. Pregnancy pathologies like preeclampsia (PE), HELLP-syndrome (HELLP), intrauterine growth restriction (IUGR) and intrahepatic cholestasis in pregnancy (ICP) are linked to disturbances in lipid metabolism. In the present study, we hypothesized a specific gestational regulation of 27-OHC and compromised 27-OHC levels due to placental and hepatic diseases in pregnancy resulting in a dysregulation of lipid metabolism.MethodsThe 27-OHC was measured by gas-chromatography-mass spectrometry (GC-MS) and related to cholesterol concentrations. In the longitudinal cohort, a complete set of samples of healthy patients (n = 33) obtained at three different time points throughout gestation and once post-partum was analyzed. In the cross sectional cohort, patients with pregnancy pathologies (IUGR n = 14, PE n = 14, HELLP n = 7, ICP n = 7) were matched to a control group (CTRL) of equal gestational ages.ResultsThe 27-OHC levels already increased in the first trimester despite lower TC concentrations (p < 0.05). During the course of pregnancy, a subtle rise in 27-OHC concentrations results in an overall decrease of 27-OHC/TC ratio in between the first (p < 0.05) and second trimester. The ratio remains stable thereafter including the post-partum period. No significant differences have been observed in pregnancy pathologies as compared to the CTRL group.ConclusionIn conclusion, 27-OHC may have a compensatory role in cholesterol metabolism early in pregnancy. The conserved 27-OHC/TC ratio in pregnancy pathologies suggest that neither the placenta nor the liver is majorly involved in the regulation of 27-OHC metabolism.

The frequency of a slightly increased serum progesterone (P) range of 1.6 to 1.9 ng/mL at peak follicular maturation prior to the luteinizing (LH) surge in natural cycles

Recently high powered studies from well known in vitro fertilization (IVF) centers have presented data showing that if the serum P is in the range of 1.6 to 1.9 ng/mL immediately prior to the human chorionic gonadotropin (hCG) injection, the pregnancy rates following embryo transfer (ET) will be reduced. The objective of the present study was to determine how frequent does this subtle rise in P occurs in natural cycles and does this range of P, presumably by advancing the window of implantation, have a negative impact on pregnancy outcome.

Reversed takotsubo cardiomyopathy in a patient with new-onset multiple sclerosis: Cause, link, or just coincidence?

A 29-year-old man with no prior medical history presented to the emergency department with acute chest pain and sudden onset of severe headache. He was alert and oriented. Physical examination revealed hypertension (192/100 mmHg). The patient underwent an urgent computed tomography (CT) scan of the head, which demonstrated a hypodense lesion in the right frontal lobe of the brain, which was later confirmed to be a demyelination lesion related to multiple sclerosis (MS) (Supplementary Fig. 1). The ECG showed no significant abnormalities (Fig. 1A). Patient laboratory findings demonstrated elevated troponin T levels (0.082 μg/L, reference < 0.014 μg/L) and normal CK–MB. Transthoracic echocardiography (TTE) displayed normal left ventricular function with no wall motion abnormalities (Supplementary Video 1). The combination of normal ECG and TTE, and his young age, the subtle rise in troponin was suspected to be related to hypertension. After pharmacological treatment of hypertension, his chest pain resolved, and after 10 days the patient was discharged in good clinical condition.

Characterization of Blood Glucose & Glycosuria following IV Trehalose (Cabaletta) administration for OPMD

CharaCTerizaTioN of Blood GluCoSe & GlyCoSuria followiNG iV TrehaloSe (CaBaleTTa) admiNiSTraTioN for oPmd H. Vornovitzki; S. Blotnick; I. Gliko-Kabir; Z. Argov; and Y. Caraco Clinical Pharmacology Unit, Hadassah University Hospital, Jerusalem, Israel; and Bioblast-Pharma Ltd., Tel-Aviv, Israel Background: Trehalose is a naturally occurring disaccharide that is currently being evaluated for the treatment of Oculopharyngeal Muscular Dystrophy (OPMD) and spinocerebellar ataxia 3. Objective: The purpose of this sub-study (part of OPMD phase 2 therapy trial) was to evaluate the extent of increase in blood glucose and the extent and duration of glycosuria associated with the intravenous administration of Trehalose. Methods: Fourteen OPMD patients received weekly intravenous 30 gr trehalose over a period of approximately 80 minutes. Just prior to and following the administration of the 3rd dose, blood were taken periodically over 5 hours for the evaluation of plasma concentration of trehalose using a validated high performance liquid chromatographic tandem mass spectrometry. On a different dosing day, plasma and urine samples were taken periodically over 8 hours for the evaluation of glucose concentration using hexokinase enzyme method on a chemistry analyzer. Results: Plasma concentration of trehalose exhibited more than 2-fold variation with AUC0→ 5 ranging from 2698 to 6103 μg*h/mL. A mild rise in plasma glucose was noted in 11 patients reaching a peak of (mean ± SD) 11.28 ± 7.27 mg% within 1-2 hours following Trehalose infusion. The rise in blood glucose was transient and it reverted back to pre-Trehalose concentrations within 1-4 hours (2.10 ± 1.29 hours). Some degree of glycosuria was noted in all patients. Maximal glucose urinary concentration varied ranging from 42 mg% and up to 1031 mg% (358 ± 341 mg%). Peak glycosuria was noted within 1-3 hours and it was evident only in 1 patient in the urine sample taken after 8 hours. Conclusions: The intravenous administration of 30 gr trehalose (Cabaletta) is associated with a subtle rise in blood glucose concentration and transient glycosuria. The presence of urinary glucose represents most probably in-situ renal activity of trehalase.

Cannabidiol Targets Mitochondria to Regulate Intracellular Ca2+Levels

Cannabinoids and the endocannabinoid system have attracted considerable interest for therapeutic applications. Nevertheless, the mechanism of action of one of the main nonpsychoactive phytocannabinoids, cannabidiol (CBD), remains elusive despite potentially beneficial properties as an anti-convulsant and neuroprotectant. Here, we characterize the mechanisms by which CBD regulates Ca(2+) homeostasis and mediates neuroprotection in neuronal preparations. Imaging studies in hippocampal cultures using fura-2 AM suggested that CBD-mediated Ca(2+) regulation is bidirectional, depending on the excitability of cells. Under physiological K(+)/Ca(2+) levels, CBD caused a subtle rise in [Ca(2+)](i), whereas CBD reduced [Ca(2+)](i) and prevented Ca(2+) oscillations under high-excitability conditions (high K(+) or exposure to the K(+) channel antagonist 4AP). Regulation of [Ca(2+)](i) was not primarily mediated by interactions with ryanodine or IP(3) receptors of the endoplasmic reticulum. Instead, dual-calcium imaging experiments with a cytosolic (fura-2 AM) and a mitochondrial (Rhod-FF, AM) fluorophore implied that mitochondria act as sinks and sources for CBD's [Ca(2+)](i) regulation. Application of carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP) and the mitochondrial Na(+)/Ca(2+) exchange inhibitor, CGP 37157, but not the mitochondrial permeability transition pore inhibitor cyclosporin A, prevented subsequent CBD-induced Ca(2+) responses. In established human neuroblastoma cell lines (SH-SY5Y) treated with mitochondrial toxins, CBD (0.1 and 1 microm) was neuroprotective against the uncoupler FCCP (53% protection), and modestly protective against hydrogen peroxide- (16%) and oligomycin- (15%) mediated cell death, a pattern also confirmed in cultured hippocampal neurons. Thus, under pathological conditions involving mitochondrial dysfunction and Ca(2+) dysregulation, CBD may prove beneficial in preventing apoptotic signaling via a restoration of Ca(2+) homeostasis.

Recent habitat degradation in karstic Lake Uluabat, western Turkey: A coupled limnological–palaeolimnological approach

The Ramsar site of Lake Uluabat, western Turkey, suffers from eutrophication, urban and industrial pollution and water abstraction, and its water levels are managed artificially. Here we combine monitoring and palaeolimnological techniques to investigate spatial and temporal limnological variability and ecosystem impact, using an ostracod and mollusc survey to strengthen interpretation of the fossil record. A combination of low invertebrate Biological Monitoring Working Party scores (<10) and the dominance of eutrophic diatoms in the modern lake confirms its poor ecological status. Palaeolimnological analysis of recent (last >200 yr) changes in organic and carbonate content, diatoms, stable isotopes, ostracods and molluscs in a lake sediment core (UL20A) indicates a 20th century trend towards increased sediment accumulation rates and eutrophication which was probably initiated by deforestation and agriculture. The most marked ecological shift occurs in the early 1960s, however. A subtle rise in diatom-inferred total phosphorus and an inferred reduction in submerged aquatic macrophyte cover accompanies a major increase in sediment accumulation rate. An associated marked shift in ostracod stable isotope data indicative of reduced seasonality and a change in hydrological input suggests major impact from artificial water management practices, all of which appears to have culminated in the sustained loss of submerged macrophytes since 2000. The study indicates it is vital to take both land-use and water management practices into account in devising restoration strategies. In a wider context, the results have important implications for the conservation of shallow karstic lakes, the functioning of which is still poorly understood.

Subtle progesterone rise in the single-dose gonadotropin-releasing hormone antagonist (cetrorelix) stimulation protocol in patients undergoing in vitro fertilization or intracytoplasmic sperm injection cycles

A subtle rise in serum progesterone during the late follicular phase in patients undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles is a frequent event that can decrease implantation and pregnancy rates in controlled ovarian hyperstimulation (COH) protocols that use a gonadotropin-releasing hormone (GnRH) antagonist. The aim of the present study was to evaluate the prevalence and effect of the subtle progesterone rise during COH with single-dose GnRH antagonist in combination with clomiphene citrate (CC) and human menopausal gonadotropins (hMG) in IVF or ICSI cycles. Ninety-five women undergoing COH with CC, hMG and a single 2.5 mg dose of the GnRH antagonist, cetrorelix, were enrolled in the study. Patients were grouped according to serum progesterone level on the day of human chorionic gonadotropin (hCG) administration (P < 1.2 ng/ml or P ≥ 1.2 ng/ml). The incidence of a subtle progesterone rise was 54.7% (52/95). The group with P ≥ 1.2 ng/ml had significantly higher serum levels of luteinizing hormone (p = 0.002) and estradiol (p < 0.001) on the day of hCG injection than the group with P < 1.2 ng/ml, and more oocytes were retrieved (p = 0.001). However, there was no significant difference in fertilization, clinical pregnancy or implantation rate between the two groups. In conclusion, a subtle progesterone rise during the late follicular phase is common but not associated with pregnancy outcome.

Differences in steroidogenic acute regulatory protein expression from the luteinizing-granulosa cells of patients undergoing in vitro fertilization with embryo transfer: Implications for cycle outcomes

Objective: Previous research has suggested a correlation between the subtle rise in progesterone induced by the administration of human chorionic gonadotropin (hCG) and cycle outcome in patients undergoing in vitro fertilization with embryo transfer (IVF-ET). The data suggest that patients who have <2-fold increase in progesterone levels will not conceive as a result of that IVF-ET attempt (poor responders). Further, if the luteinizing-granulosa cells of poor responders are placed in culture, their steroid hormone production will be significantly less than that of the luteinizing-granulosa cells of patients with a normal response to hCG (>3-fold; normal responders). Recent studies have demonstrated that steroidogenic acute regulatory protein (StAR) regulates the rate-limiting step in steroid hormone biosynthesis. The objective of the present study was to determine whether StAR expression differed in normal responders and poor responders undergoing IVF-ET. Study Design: The luteinizing-granulosa cells of 6 patients were isolated after follicular aspiration and assayed for StAR expression. Three sets of cells were from patients exhibiting a normal response to hCG administration and 3 sets were from patients exhibiting a poor response. Results: Data suggest a 17% drop in StAR protein in patients with a poor response to hCG administration when compared with those with a normal response. Conclusions: Although StAR protein was expressed in all 6 cellular extracts, expression appeared greatest in cells recovered from normal responders. Further, although two thirds of the patients with a normal response reported term pregnancies, no pregnancies were reported in the poor responders. Low levels of progesterone and absence of pregnancy may be due to a defect in the mechanism that converts granulosa and theca-lutein cells to luteal cells after the luteinizing hormone surge (or hCG administration). Data from the current study would suggest that the StAR protein may be involved. (Am J Obstet Gynecol 2002;186:872-5.)

Differences in StAR Protein Expression From the Luteinizing-Granulosa Cells of IVF-ET Patients: Implications for Cycle Outcomes

Objectives: Previous research from this and other laboratories has suggested a correlation between the subtle rise in Progesterone (P) induced by the administration of hCG, and cycle outcome in patients undergoing in vitro fertilization with embryo transfer (IVF-FT). The data suggests patients who have <2-fold increase in P following hCG will not conceive on that IVF-ET attempt (Poor responders; PR). Further, if the luteinizing-granulosa cells (LGC) of PR are placed in culture, their steroid hormone production will be significantly less than the LGC of patients with a normal response to hCG (>3-fold; NR). Recent studies have demonstrated steroidogenic acute regulatory protein (StAR) regulates the rate-limiting step in steroid hormone biosynthesis. The objective of the present study was to determine if StAR expression differed in NR and PR patients undergoing IVF-ET.

Sandwich Configuration of Type I Collagen Suppresses Progesterone Production in Primary Cultured Porcine Granulosa Cells by Reducing Gene Expression of Cytochrome P450 Cholesterol Side-Chain Cleavage Enzyme

When porcine granulosa cells were cultured on type I collagen (TIC)-coated dishes, progesterone was continuously secreted in the culture medium. However, when cells were overlaid with a TIC gel, progesterone production was decreased to 34% (day 3) and 16% (day 4) of the value measured for cells without the overlay. The effect of TIC gel overlay on cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), which catalyzes the conversion of cholesterol to pregnenolone and is thought to be the rate-limiting enzyme in the conversion of cholesterol to progesterone, was examined. P450scc gene expression in cells overlaid with a TIC gel was decreased to 62% (day 3) and 36% (day 4) of the value measured for cells without the overlay. Amounts of P450scc were also reduced in the cells overlaid with a TIC gel. When pregnenolone, the direct precursor of progesterone, was added to the culture medium, the increase in progesterone production by cells overlaid with a TIC gel was much greater than that for cells without a TIC gel and a statistical difference in progesterone production was no longer observed between the two groups of cells. Treatment of the cells with human FSH (hFSH) enhanced progesterone production in a dose-dependent manner, irrespective of the presence of a TIC gel overlay. Moreover, hFSH induced P450scc gene expression in cells with and without a TIC gel overlay. These results indicate that a TIC gel overlay reduces progesterone production in granulosa cells via the suppression of P450scc gene expression. This supports the possibility that the existence of a TIC gel on the apical side of granulosa cells prevents the spontaneous luteinization of granulosa cells cultured on TIC-coated dishes. The fact that hFSH overcomes the suppressive effect of the TIC gel overlay on progesterone production may explain the mechanism for the subtle rise in serum progesterone concentration in the late follicle phase of the “in vitro fertilization” program.

Altering the timing of human chorionic gonadotropin injection according to serum progesterone (P) concentrations improves embryo quality in cycles with subtle P rise

To investigate the effect of earlier administration of hCG according to serum concentrations of P on the outcome of IVF-ET in cycles in which a subtle rise in serum P (1.0 to 2.0 ng/mL; conversion factor to SI unit, 3.180) occurred during the follicular phase. Retrospective study. A total of 110 infertile women underwent 124 cycles of IVF-ET at Tottori University Hospital. Serum was obtained daily or every 12 hours from day 7 until the administration of hCG. Serum E2 and P concentrations were measured by RIA. In 19 of 36 subtle P rise cycles, hCG injection was given when the levels of serum P exceeded 1.0 ng/mL ("rescued" subtle P rise). Parameters of IVF outcomes for the no P rise, the subtle P rise, and the rescued subtle P rise cycles were compared. The mean day of hCG administration in the rescued cycles was 1 day earlier than those of the subtle P rise and no P rise cycles. The mean number of oocytes collected was significantly higher in the subtle P rise and rescued P rise cycles than in the no P rise cycles. The mean follicular diameter on the day of hCG administration was 13.9 mm in the rescued cycles, significantly smaller than those of the no P rise and subtle P rise cycles. However, there was no significant difference in the cleavage rates between the three groups. The rate of embryonic development beyond four-cell stage was increased significantly in the rescued cycles and no P rise cycles versus the subtle P rise cycles. Embryos obtained in the no P rise and rescued cycles were of better morphological quality than those obtained in the P rise cycles. The implantation rate was significantly higher in the rescued cycles than in the P rise cycles. The data suggest that, if hCG is administered when a subtle P rise is detected, embryo quality and subsequent implantation rate can be improved.

Endocrinology: Reduced implantation rate associated with a subtle rise in serum progesterone concentration during the follicular phase of cycles stimulated with a combination of a gonadotrophin-releasing hormone agonist and gonadotrophin

Our objective was to assess the effects of subtle increases in serum progesterone concentration (1.0-2.0 ng/ml) on the outcome of in-vitro fertilization (IVF), particularly on the quality of embryos, during the follicular phase of cycles stimulated with gonadotrophin-releasing hormone agonist (GnRHa) and human menopausal gonadotrophin (HMG). A total of 97 patients underwent 116 cycles of IVF and were stimulated with a combination of HMG and GnRHa. They were divided into two groups: those with a subtle progesterone rise and those with no progesterone rise. The two groups were compared with respect to serum oestradiol, progesterone, immunoreactive luteinizing hormone (I-LH), bioactive LH (B-LH), and results of IVF. The groups did not differ significantly in mean age or in total dose of HMG received. On the day that human chorionic gonadotrophin was administered, concentrations of oestradiol and progesterone were significantly higher in the subtle progesterone rise cycles than in the no progesterone rise cycles. In the no progesterone rise cycles, the percentages for embryos beyond the 4-cell stage, grade 1 embryos, and implantation rates were significantly higher than those in subtle progesterone rise cycles. The combination of GnRHa and HMG eliminated any significant rise in serum I-LH or B-LH concentration during the follicular phase, but did not suppress the subtle rise in progesterone. These results confirm our previous finding that a subtle progesterone rise adversely affects the outcome of IVF. It is also suggested that a reduction in embryo quality may influence the lower rate of implantation in subtle progesterone rise cycles.