Potentials of MicroRNA in Early Detection of Ovarian Cancer by Analytical Electrical Biosensors.

The importance of nanotechnology in medical applications especially with biomedical sensing devices is undoubted. Several medical diagnostics have been developed by taking the advantage of nanomaterials, especially with electrical biosensors. Biosensors have been predominantly used for the quantification of different clinical biomarkers toward detection, screening, and follow-up the treatment. At present, ovarian cancer is one of the severe complications that cannot be identified until it becomes most dangerous as the advanced stage. Based on the American Cancer Society, 20% of cases involved in the detection of ovarian cancer are diagnosed at an early stage and 80% diagnosed at the later stages. The patient just has a common digestive problem and stomach ache as early symptoms and people used to ignore these symptoms. Micro ribonucleic acid (miRNA) is classified as small non-coding RNAs, their expressions change due to the association of cancer development and progression. This article reviews and discusses on the currently available strategies for the early detection of ovarian cancers using miRNA as a biomarker associated with electrical biosensors. A unique miRNA-based biomarker detections are specially highlighted with biosensor platforms to diagnose ovarian cancer.

Determination and benchmarking of 27Al(d,α) and 27Al(d,p) reaction cross sections for energies and angles relevant to NRA.

The cross-sections of deuteron-induced nuclear reactions suitable for ion beam analysis, measured in different laboratories, are often significantly different. In the present work, differential cross-sections of 27Al(d,p) and 27Al(d,α) reactions were measured, and the cross sections benchmarked with thick target spectra obtained from pure aluminium for the first time in two independent laboratories. The 27Al(d,p) and (d,α) differential cross-sections were measured between 1.4 and 2 MeV at scattering angles of 165°, 150°, and 135° in the VDGT laboratory in Tehran (Iran), and the same measurements for detector angle of 150° were repeated from scratch, including target making, with independent equipment on the SAFIR platform at INSP in Paris (France). The results of these two measurements at 150° are in good agreement, and for the first time a fitted function is proposed to describe the Al-cross sections for which no suitable theoretical expression exists. The obtained differential cross-sections were validated through benchmarking, by fitting with SIMNRA deuteron-induced particle spectra obtained from a high purity bulk Al target at both labs for deuteron incident energies between 1.6 and 2 MeV. The thick target spectra are well-reproduced. The evaluated and benchmarked cross sections have been uploaded to the ion beam analysis nuclear data library database (www-nds.iaea.org/ibandl/).

Synthesis and characterization of reduced graphene oxide using the aqueous extract of Eclipta prostrata.

In this study, biological deoxygenation of graphene oxide (GO) using an Eclipta prostrata phytoextract was performed via the infusion method. The presence of oxide groups on the surface of graphene and removal of oxides groups by reduction were characterized through morphological and structural analyses. Field emission scanning electron microscopy images revealed that the synthesized GO and rGO were smooth and morphologically sound. Transmission electron microscopy images showed rGO developing lattice fringes with smooth edges and transparent sheets. Atomic force microscopy images showed an increase in the surface roughness of graphite oxide (14.29 nm) compared with that of graphite (1.784 nm) due to the presence of oxide groups after oxidation, and the restoration of surface roughness to 2.051 nm upon reduction. Energy dispersive X-ray analysis indicated a difference in the carbon/oxygen ratio between GO (1.90) and rGO (2.70). Fourier-transform infrared spectroscopy spectrum revealed peak stretches at 1029, 1388, 1578, and 1630 cm-1 for GO, and a decrease in the peak intensity after reduction that confirmed the removal of oxide groups. X-ray photoelectron microscopy also showed a decrease in the intensity of oxygen peak after reduction. In addition, thermogravimetric analysis suggested that rGO was less thermally stable than graphite, graphite oxide, and GO, with rGO decomposing after heating at temperatures ranging from room temperature to 600 °C.

Study of DOK4 gene expression and promoter methylation in sporadic breast cancer.

The analysis of DNA methylation patterns in circulating cell-free DNA in body fluids is an analyte of great interest in clinical research. Downstream of Kinase (DOK) proteins represent a multigenic family of adaptors that includes negative regulators of immune cell signaling and plays important roles in signaling, cellular growth, and survival. The aim of the present study was to investigate the pattern of promoter methylation and expression of the DOK4 gene in breast cancer, and its possible association with histoclinical characteristics. The mRNA expression of the DOK4 gene was evaluated in 164 breast tissues using Real-Time RT-PCR. The promoter methylation of this gene was evaluated in breast tissues and plasma free nucleic acids by MS-PCR. The associations of gene expression and DNA methylation with histoclinical characteristics of the patients were studied. The data indicated that DOK4 mRNA expression was significantly downregulated in breast tumors compared with normal control in all the stages. About 40% of breast tumors showed DOK4 promoter methylation, which somehow confirms the DOK4 promoter methylation rate in the plasma. The data revealed that the reduction in DOK4 expression in all breast cancer groups could well endorse this gene as a candidate possible marker for future investigations on breast cancer management. The DOK4 methylation pattern in breast tissue was correlated with plasma free nucleic acids but the state of DOK4 promoter methylation alone may not be sufficient to differentiate between the two cancerous and normal groups.

Asymptotic solutions of fractional interval differential equations with nonsingular kernel derivative.

Realizing the behavior of the solution in the asymptotic situations is essential for repetitive applications in the control theory and modeling of the real-world systems. This study discusses a robust and definitive attitude to find the interval approximate asymptotic solutions of fractional differential equations (FDEs) with the Atangana-Baleanu (A-B) derivative. In fact, such critical tasks require to observe precisely the behavior of the noninterval case at first. In this regard, we initially shed light on the noninterval cases and analyze the behavior of the approximate asymptotic solutions, and then, we introduce the A-B derivative for FDEs under interval arithmetic and develop a new and reliable approximation approach for fractional interval differential equations with the interval A-B derivative to get the interval approximate asymptotic solutions. We exploit Laplace transforms to get the asymptotic approximate solution based on the interval asymptotic A-B fractional derivatives under interval arithmetic. The techniques developed here provide essential tools for finding interval approximation asymptotic solutions under interval fractional derivatives with nonsingular Mittag-Leffler kernels. Two cases arising in the real-world systems are modeled under interval notion and given to interpret the behavior of the interval approximate asymptotic solutions under different conditions as well as to validate this new approach. This study highlights the importance of the asymptotic solutions for FDEs regardless of interval or noninterval parameters.

The relation of serum prolactin levels and Toxoplasma infection in humans.

BACKGROUND: Toxoplasma gondii is an intracellular protozoan parasite distributed worldwide. Although the infection is benign in immunocompetent individuals, it is life threatening and complicated in immunocompromised patients and fetuses of pregnant women who received their first exposure to T. gondii during the pregnancy. Prolactin (PRL) is a hormone that is secreted by the pituitary gland, and it is confirmed that it plays a role in the immune system. The present study was carried out to assess the possible relation between serum PRL levels and Toxoplasma infection frequency in human. METHODS: In this cross-sectional study, 343 serum samples (240 from women and 103 from men) were collected from individuals who were referred for PRL checking in laboratories of Karaj, Iran. Blood samples were collected, and sera were separated and analyzed for the detection of anti-Toxoplasma IgG antibody by ELISA method. The levels of PRL were measured by Roche Elecsys 2010 analyzer, electrochemiluminescence technology. RESULTS: Of 343 sera, 110 samples (32%) consisting of samples from 42 men and 68 women had anti-T. gondii IgG antibody. The prevalence of T. gondii infection in women with high PRL levels was lower than that in the comparison group with normal levels of PRL and the relationship between these two parameters was statistically significant (P=0.016). In women with hyperprolactinemia, by increasing of PRL levels, the prevalence of T. gondii infection was reduced. CONCLUSION: The results of the current study confirmed the previous studies based on immunoregulatory role of PRL and indicated that high levels of PRL could be related to Toxoplasma seronegativity in women.

Design of a dual-promoter expression vector harboring Sag1 and Gra7 genes from Toxoplasma gondii (RH strain).

Toxoplasmosis, a parasitic disease caused by Toxoplasma gondii, has possible irreparable consequences in immunocompromised patients and fetuses. Finding an effective method of prevention, such as vaccination, is crucial because of the global distribution of the parasite and the lack of effective anti-toxoplasmosis drugs. The Sag1 and Gra7 antigens of T. gondii can induce strong humoral and cell-mediated immune responses. Therefore, to develop a novel DNA vaccine against toxoplasmosis, we prepared a eukaryotic construct expressing the Sag1 and Gra7 genes of T. gondii (RH strain). We then verified the ability of this construct to produce the corresponding Sag1 and Gra7 antigens in mammalian cells. Using specific primers, the complete coding sequences of Sag1 and Gra7 genes were amplified by polymerase chain reaction (PCR) from the genomic DNA of T. gondii. Then, both genes were subcloned into pVitro2-neo-mcs plasmid. The pVitro-Sag1-Gra7 construct was subjected to colony PCR, enzymatic digestion, and sequencing to confirm successful subcloning. Sag1 and Gra7 expression in HeLa cells was investigated. Sag1 and Gra7 were successfully subcloned in pVitro2-neo-mcs plasmid. The expression of Sag1 and Gra7 in HeLa cells was confirmed through Western blot analysis. The recombinant pVitro-Sag1-Gra7 construct that simultaneously produces Sag1 and Gra7 antigens in one mammalian cell may be used to develop a novel protective vaccine against toxoplasmosis.

Effects of morphine on the biomass and development rate of Chrysomya albiceps (Diptera: Calliphoridae), a forensically important species.

The aim of this study was to determine the effects of morphine on the biomass and development rate of Chrysomya albiceps (Diptera: Calliphoridae). C. albiceps, a well-known forensically important species which is among the first wave of faunal succession on human cadavers, which makes it a valuable source of information for the estimation of postmortem interval (PMI). Antemortem exposure to substances such as drugs and toxins may have an effect on the biomass and/or on the development rate of insects that feed on carcass, which may directly affect PMI estimation. In this study, three rabbits were administered 12.5, 25 or 50 mg/ml of morphine sulfate via ear perfusion over a period of 3 hours, and a fourth rabbit, which did not receive morphine, was used as a control. The rabbits were sacrificed using chloroform 30 minutes after morphine administration. The tissues were analyzed for the presence of morphine using HPLC-UV. Morphine was detected in all tissues of rabbits that received morphine, except in the bile and spleen of the rabbit which received 12.5 mg/ml dose of morphine. The presence of morphine in rabbit tissues retarded larval development rate, but accelerated the puparial development rate. The rate of development of C. albiceps larvae that fed on rabbits which received 25 and 50 mg/ml dosages of morphine was 9 days each. However, the rate of larval development was similar in the 12.5 mg/ml morphine group and the control; 6 days. Results of this study show that an underestimation of the postmortem interval of 72 h based on larval development and an overestimation of 24 to 48 h based on puparial development is possible if the presence of morphine in tissues is not considered. Moreover, the decreased larval development rate caused an increase larval length and weight compared with the control group. In this study, we found a strong correlation between the concentration of morphine administered and concentrations in rabbit tissues. In the estimation of PMI, it is recommended that effects of drugs such as morphine on the development of carcass colonizers be considered.

Deficiency of filaggrin regulates endogenous cysteine protease activity, leading to impaired skin barrier function.

BACKGROUND: Atopic dermatitis (AD) is a common inflammatory skin disorder, characterized by skin barrier defects and enhanced allergen priming. Null mutations in the filaggrin gene (FLG) are strongly associated with moderate to severe AD, but the pathways linking barrier dysfunction and cutaneous inflammation are still largely unknown. AIM: To assess alteration of endogenous cysteine protease activity in FLG-deficient keratinocytes, and to determine whether the alteration in cysteine protease activity affects epidermal barrier function and associated gene and protein expression. METHODS: We established a stable FLG knockdown cell line, and reconstructed epidermal equivalents in vitro. Barrier function of the reconstructed epidermis, the barrier-associated genes and proteins, and the activity of endogenous cysteine proteases were tested. Inhibitors of cysteine proteases were used to further evaluate the role of endogenous cysteine proteases in epidermal barrier function. RESULTS: FLG knockdown induced impaired epidermal barrier function. Microarray, western blotting and fluorescence staining showed reduced expression of K10, ZO-1, E-cadherin, claudin-1 and occludin in FLG knockdown keratinocytes. Compared with cysteine protease activity in control cells, protease activity was dramatically enhanced in FLG knockdown keratinocytes. Furthermore, administration of cysteine protease inhibitors significantly recovered expression of K10 and tight junction proteins, and the barrier defect induced by FLG deficiency. CONCLUSIONS: This is the first observation of elevated endogenous cysteine protease activity in FLG-deficient keratinocytes, which may play an important role in impaired barrier function in AD skin. Modulation of cysteine protease activity might be a novel therapeutic approach for AD treatment.

Evaluation of Toxoplasma gondii soluble, whole and excretory/secretary antigens for diagnosis of toxoplasmosis by ELISA test.

The present study was performed to compare the soluble, whole and excretory/secretary antigens of Toxoplasma gondii (RH strain) in diagnosis of toxoplasmosis by ELISA method. Tachyzoites of T. gondii, RH strain were injected in intra-peritoneal cavity of BALB/c mice, after 4 days tachyzoites were harvested by peritoneal washing of the mice. For soluble antigen, exudates were centrifuged and sediment sonicated and then centrifuged at 4 °C, 1 h, supernatant collected and density of protein determined by Bradford method. For whole antigen after collecting, washing and centrifuging of peritoneal fluid the tachyzoites sediment was counted. In excretory/secretary antigen 1.5 × 108 tachyzoites were transferred in 1 ml tube of saline and incubated under mild agitation and after centrifuging, supernatant was collected and protein density determined by Bradford method. 176 human serum samples were evaluated for T. gondii IgG antibody with prepared antigens, and finally serum samples were evaluated by commercial ELISA kit (Trinity, USA) which was considered as gold standard method. In this study sensitivity and specificity of prepared antigens compared with commercial kit in ELISA method. Sensitivity and specificity of soluble antigen was 91.4 and 74.5 %, in whole antigen these parameters were 77.1 and 77.3 % and in excretory/secretary antigen were 28.5 and 74.5 % respectively. Soluble antigen had high levels of sensitivity and specificity in ELISA method and the results were rather resemble to commercial kit (Trinity, USA).

PCR-RFLP analysis of Plasmodium vivax reticulocyte binding protein2c gene in field isolates of Iran.

A family of reticulocyte-binding proteins of Plasmodium vivax (PvRBP) is localised at the apical pole of the merozoites and appears to bind to reticulocytes specifically and has also been involved in identifying host cells. Protein component produced by the Pvrbp2c gene is highly antigenic. The aim of this study was to detect the genetic diversity in the Pvrbp2c gene of Iranian P. vivax field isolates using the polymerase chain reaction- restricted fragment length polymorphism (PCR-RFLP) technique. A total of 79 P. vivax malaria patients with fever participated in the study. Alu1 and Apo1 restriction enzymes were independently used to identify allelic variants of the Pvrbp2c gene. All of the samples exhibited a single band of about 2 Kb in nested PCR. Among 79 P. vivax field isolates in the RFLP with Apo1 and Alu1 restriction enzymes, 15 and nine patterns were observed, respectively. In total, 24 various patterns were detected from the combined findings of both Alu1 and Apo1 fragments in RFLP. This study revealed that Pvrbp2c has genetic diversity in southeast Iran. Genotyping of Pvrbp2c not only shows the heterogeneity of P. vivax but also provides important information that could be used to control vivax malaria.

Comparison of the Toxoplasma gondii mice and cell culture derived antigens in ELISA assay.

Toxoplasmosis is an infectious disease caused by the coccidian parasite Toxoplasma gondii. Diagnosis is based on serological methods with detection of specific IgG and IgM antibodies. The present study was performed to compare the sensitivity and specificity of soluble antigen of T. gondii, RH strain obtained from mice and cell culture in ELISA method. Tachyzoites of T. gondii, RH strain that inoculated in mice peritoneum were collected. At the same time, tachyzoites were harvested from HeLa cell culture that infected with the parasite. Soluble antigen was prepared and ELISA method performed on 100 serum samples that were collected from different laboratories in Tehran, Iran. Commercial Trinity kit was used as gold standard. The sensitivity and specificity of T.gondii soluble antigen were higher in antigens that obtained from cell culture in comparison with mice peritoneum. T. gondii cell culture derived antigen has high sensitivity and specificity in ELISA test.

Comparison of the Toxoplasma gondii mice and cell culture derived antigens in ELISA assay

Abstract. Toxoplasmosis is an infectious disease caused by the coccidian parasite Toxoplasma gondii. Diagnosis is based on serological methods with detection of specific IgG and IgM antibodies. The present study was performed to compare the sensitivity and specificity of soluble antigen of T. gondii, RH strain obtained from mice and cell culture in ELISA method. Tachyzoites of T. gondii, RH strain that inoculated in mice peritoneum were collected. At the same time, tachyzoites were harvested from HeLa cell culture that infected with the parasite. Soluble antigen was prepared and ELISA method performed on 100 serum samples that were collected from different laboratories in Tehran, Iran. Commercial Trinity kit was used as gold standard. The sensitivity and specificity of T.gondii soluble antigen were higher in antigens that obtained from cell culture in comparison with mice peritoneum. T. gondii cell culture derived antigen has high sensitivity and specificity in ELISA test.

High-fat diet with stress impaired islets' insulin secretion by reducing plasma estradiol and pancreatic GLUT2 protein levels in rats' proestrus phase.

This study was conducted to determine whether two estrus phases (proestrus and diestrus) in female rats may influence the metabolic response to a high-fat diet and/or stress, focusing on pancreatic insulin secretion and content. Animals were divided into high-fat and normal diet groups, then each group was subdivided into stress and non-stress groups, and finally, each one of these was divided into proestrus and diestrus subgroups. At the end of high-fat diet treatment, foot-shock stress was applied to the animals. Then, blood samples were taken to measure plasma factors. Finally, the pancreas was removed for determination of glucose transporter 2 (GLUT2) protein levels and assessment of insulin content and secretion of the isolated islets. In the normal and high-fat diet groups, stress increased plasma corticosterone concentration in both phases. In both study phases, high-fat diet consumption decreased estradiol and increased leptin plasma levels. In the high-fat diet group in response to high glucose concentration, a reduction in insulin secretion was observed in the proestrus phase compared with the same phase in the normal diet group in the presence and absence of stress. Also, high-fat diet decreased the insulin content of islets in the proestrus phase compared with the normal diet. High-fat diet and/or stress caused a reduction in islet GLUT2 protein levels in both phases. In conclusion, it seems possible that high-fat diet alone or combined with foot-shock, predispose female rats to impaired insulin secretion, at least in part, by interfering with estradiol levels in the proestrus phase and decreasing pancreatic GLUT2 protein levels.

Computational simulation of temperature and velocity distribution in human upper respiratory airway during inhalation of hot air.

The present study provides an accurate simulation of velocity and temperature distributions of inhalation thermal injury in a human upper airway, including vestibule, nasal cavity, paranasal sinuses, nasopharynx, oropharynx, larynx, and upper part of main bronchus. To this end, a series of CT scan images, taken from an adult woman, was used to construct a three dimensional model. The airway walls temperature was adjusted according to existing in vivo temperature measurements. Also, in order to cover all breathing activities, five different breathing flow rates (10, 15, 20, 30, and 40 l/min) and different ambient air temperatures (100, 200, 300, 400, and 500 °C) were studied. Different flow regimes, including laminar, transitional, and turbulence were considered and the simulations were validated using reliable experimental data. The results show that nostrils, vestibule, and nasal cavity are damaged more than other part of airway. Finally, In order to obtain the heat flux through the walls, correlations for Nusselt number for each individual parts of airway (vestibule, main upper airway, nasopharynx etc.,) are proposed.

Enhanced isolation of lymphoid cells from human skin.

Studying skin immune cells under various pathophysiological conditions is vital for understanding the nature of cutaneous inflammatory responses. Available methods of isolating cells from the skin have relatively low yield or require in vitro culture. To increase the effective isolation of skin immune cells, we used collagenase P treatment. The number of T cells obtained ex vivo using this technique was dramatically greater than that obtained with conventional methods, without the need for long-term culture. The phenotype and function of isolated cells were comparable with those of cells isolated by EDTA treatment. Collagenase P-based methods will enhance the ability to investigate lymphoid cell function in both healthy and diseased skin.

Dengue NS1 antigen contributes to disease severity by inducing interleukin (IL)-10 by monocytes.

Both dengue NS1 antigen and serum interleukin (IL)-10 levels have been shown to associate with severe clinical disease in acute dengue infection, and IL-10 has also been shown to suppress dengue-specific T cell responses. Therefore, we proceeded to investigate the mechanisms by which dengue NS1 contributes to disease pathogenesis and if it is associated with altered IL-10 production. Serum IL-10 and dengue NS1 antigen levels were assessed serially in 36 adult Sri Lankan individuals with acute dengue infection. We found that the serum IL-10 levels correlated positively with dengue NS1 antigen levels (Spearman's r = 0·47, P < 0·0001), and NS1 also correlated with annexin V expression by T cells in acute dengue (Spearman's r = 0·63, P = 0·001). However, NS1 levels did not associate with the functionality of T cell responses or with expression of co-stimulatory molecules. Therefore, we further assessed the effect of dengue NS1 on monocytes and T cells by co-culturing primary monocytes and peripheral blood mononuclear cells (PBMC), with varying concentrations of NS1 for up to 96 h. Monocytes co-cultured with NS1 produced high levels of IL-10, with the highest levels seen at 24 h, and then declined gradually. Therefore, our data show that dengue NS1 appears to contribute to pathogenesis of dengue infection by inducing IL-10 production by monocytes.

Decellularized human amniotic membrane: more is needed for an efficient dressing for protection of burns against antibiotic-resistant bacteria isolated from burn patients.

Human amniotic membranes (HAMs) have attracted the attention of burn surgeons for decades due to favorable properties such as their antibacterial activity and promising support of cell proliferation. On the other hand, as a major implication in the health of burn patients, the prevalence of bacteria resistant to multiple antibiotics is increasing due to overuse of antibiotics. The aim of this study was to investigate whether HAMs (both fresh and acellular) are an effective antibacterial agent against antibiotic-resistant bacteria isolated from burn patients. Therefore, a HAM was decellularized and tested for its antibacterial activity. Decellularization of the tissue was confirmed by hematoxylin and eosin (H&E) and 4,6-diamidino-2-phenylindole (DAPI) staining. In addition, the cyto-biocompatibility of the acellular HAM was proven by the cell viability test (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, MTT) and scanning electron microscopy (SEM). The resistant bacteria were isolated from burns, identified, and tested for their susceptibility to antibiotics using both the antibiogram and polymerase chain reaction (PCR) techniques. Among the isolated bacteria, three blaIMP gene-positive Pseudomonas aeruginosa strains were chosen for their high resistance to the tested antibiotics. The antibacterial activity of the HAM was also tested for Klebsiella pneumoniae (American Type Culture Collection (ATCC) 700603) as a resistant ATCC bacterium; Staphylococcus aureus (mecA positive); and three standard strains of ATCC bacteria including Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27833), and S. aureus (ATCC 25923). Antibacterial assay revealed that only the latter three bacteria were susceptible to the HAM. All the data obtained from this study suggest that an alternative strategy is required to complement HAM grafting in order to fully protect burns from nosocomial infections.

The relationship between transcript expression levels of nuclear encoded (TFAM, NRF1) and mitochondrial encoded (MT-CO1) genes in single human oocytes during oocyte maturation.

In some cases of infertility in women, human oocytes fail to mature when they reach the metaphase II (MII) stage. Mitochondria plays an important role in oocyte maturation. A large number of mitochondrial DNA (mtDNA), copied in oocytes, is essential for providing adenosine triphosphate (ATP) during oocyte maturation. The purpose of this study was to identify the relationship between transcript expression levels of the mitochondrial encoded gene (MT-CO1) and two nuclear encoded genes, nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM) in various stages of human oocyte maturation. Nine consenting patients, age 21-35 years old, with male factors were selected for ovarian stimulation and intracytoplasmic sperm injection (ICSI) procedures. mRNA levels of mitochondrial-related genes were performed by singlecell TaqMan® quantitative real-time polymerase chain reaction (qRT-PCR). There was no significant relationship between the relative expression levels in germinal vesicle (GV) stage oocytes (p = 0.62). On the contrary, a significant relationship was seen between the relative expression levels of TFAM and NRF1 and the MT-CO1 genes at the stages of metaphase I (MI) and MII (p = 0.03 and p = 0.002). A relationship exists between the transcript expression levels of TFAM and NRF1, and MT-CO1 genes in various stages of human oocyte maturation.