Integrating computational and experimental approaches in discovery and validation of MmpL3 pore domain inhibitors for specific labelling of Mycobacterium tuberculosis.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), continues to pose a significant global health threat. Identifying new druggable targets is crucial for the advancement of drug development. Equally critical is the development of precise methods for monitoring Mtb to effectively combat this disease. Addressing these needs, our study pinpointed the pore domain (PD) of MtbMmpL3 as a new binding site for virtual screening, which led to the discovery of the small molecule ZY27. To confirm the binding site and action mode of ZY27, we employed cosolvent molecular dynamics (CMD), steered molecular dynamics (SMD), and long timescale molecular dynamics (MD) simulations of 5 µs. These in silico studies verified that ZY27 binds to the PD of MtbMmpL3. In antimicrobial activity tests, ZY27 exhibited potent anti-Mtb activity and high selectivity among mycobacterial species. Whole-genome sequencing of spontaneous ZY27-resistant Mtb variants, complemented by acid-fast staining experiments, confirmed that ZY27 specifically targets MtbMmpL3. Utilizing the ligand-protein binding data, we designed and synthesized two solvatochromic fluorescent probes, 27FP1 and 27FP2, based on ZY27. Further investigations through flow cytometry and confocal microscopy confirmed that these probes specifically label Mtb cells via the MtbMmpL3 binding mechanism.

Rational Design of a Novel Class of Human ClpP Agonists through a Ring-Opening Strategy with Enhanced Antileukemia Activity.

The activation of Homo sapiens Casein lysing protease P (HsClpP) by a chemical or genetic strategy has been proved to be a new potential therapy in acute myeloid leukemia (AML). However, limited efficacy has been achieved with classic agonist imipridone ONC201. Here, a novel class of HsClpP agonists is designed and synthesized using a ring-opening strategy based on the lead compound 1 reported in our previous study. Among these novel scaffold agonists, compound 7k exhibited remarkably enhanced proteolytic activity of HsClpP (EC50 = 0.79 ± 0.03 µM) and antitumor activity in vitro (IC50 = 0.038 ± 0.003 µM). Moreover, the intraperitoneal administration of compound 7k markedly suppressed tumor growth in Mv4-11 xenograft models, achieving a tumor growth inhibition rate of 88%. Concurrently, 7k displayed advantageous pharmacokinetic properties in vivo. This study underscores the promise of compound 7k as a significant HsClpP agonist and an antileukemia drug candidate, warranting further exploration for AML treatment.

Discovery and Mechanistic Study of Novel Mycobacterium tuberculosis ClpP1P2 Inhibitors.

Caseinolytic protease P (ClpP) responsible for the proteolysis of damaged or misfolded proteins plays a critical role in proteome homeostasis. MtbClpP1P2, a ClpP enzyme complex, is required for survival in Mycobacterium tuberculosis, and it is therefore considered as a promising target for the development of antituberculosis drugs. Here, we discovered that cediranib and some of its derivatives are potent MtbClpP1P2 inhibitors and suppress M. tuberculosis growth. Protein pull-down and loss-of-function assays validated the in situ targeting of MtbClpP1P2 by cediranib and its active derivatives. Structural and mutational studies revealed that cediranib binds to MtbClpP1P2 by binding to an allosteric pocket at the equatorial handle domain of the MtbClpP1 subunit, which represents a unique binding mode compared to other known ClpP modulators. These findings provide us insights for rational drug design of antituberculosis therapies and implications for our understanding of the biological activity of MtbClpP1P2.

Development speed of sibling embryo positively reflects live birth rate after fresh day 3 embryo transfer.

The ability of sibling embryos to form blastocysts may reflect the developmental potential of the embryos that were transferred into the uterus. The purpose of the study was to investigate whether the development speed of sibling embryos positively reflects the live birth rate following fresh embryo transfer. We examined 1262 cycles of women who underwent day 3 (D3) cleavage embryo transfer in the Peking Union Medical College Hospital in 2015-2020, who were divided into three groups (D5, D5 + D6, and D6) according to blastocyst formation. The live birth rate in patients with blastocysts that formed on D6 was significantly lower than the other two groups (36.1%, 45.6% and 44.7%, P < 0.05). For women with blastocysts that formed on D6, the live birth rate was higher in those with more good quality blastocysts than poor-quality blastocysts (42.4 vs 32.3%, P < 0.05). Multiple regression analysis showed that the blastocyst development speed of sibling embryos was an independent factor affecting live birth after fresh embryo transfer (P < 0.05). We concluded that the blastocyst development speed of sibling embryos may reflect live birth rate following the transfer of D3 cleavage embryos.

Single-dose administration of a short-acting gonadotropin-releasing hormone agonist does not affect cycle outcome in frozen-thawed embryo transfer cycles.

OBJECTIVE: This prospective study aimed to assess the effect of short-acting gonadotropin-releasing hormone agonist (GnRHa) administration on pregnancy outcomes in frozen-thawed embryo transfer (FET) cycles. METHODS: Patients who planned to have FET in Peking Union Medical College Hospital (China) were recruited for this study and randomly assigned into two groups. Patients in the experimental group (n = 460) received triptorelin acetate on the day of embryo transfer along with routine luteal support. Patients in the control group (n = 433) only received luteal support. One dose (0.1 mg) of a short-acting GnRHa was administered on the day of blastocyte transfer. The rates for clinical pregnancy, biochemical pregnancy, implantation, miscarriage, and ectopic pregnancy were compared between the groups. RESULTS: There were no significant differences in the number and quality of blastocytes transferred between the two groups. In the experimental and control groups, the clinical pregnancy rate was 56.3% and 50.58%, the biochemical pregnancy rate was 15.78% and 18.94%, and the median implantation rate was 39.98% and 38.01%, respectively, with no significant difference between the groups. Biochemical pregnancy and abortion and the ectopic pregnancy rate were not significantly different between the two groups. CONCLUSION: In FET cycles, a GnRHa does not affect the pregnancy outcome.

Antimicrobial activities of a small molecule compound II-6s against oral streptococci.

Background: The side effects of present antimicrobials like chlorhexidine (CHX) and the emergence of drug resistance necessitate the development of alternative agents to control dental caries. Aim: This study developed a novel small molecule, namely II-6s, and investigated its antimicrobial activities against common oral streptococci associated with dental caries. Methods: The susceptibility of streptococci to II-6s was evaluated by the microdilution method, time-kill assay and scanning electron microscopy. The exopolysaccharides, dead/live bacteria and bacterial composition of the II-6s-treated Streptococcus mutans/Streptococcus gordonii/Streptococcus sanguinis 3-species biofilms were analyzed by confocal laser scanning microscopy, fluorescent in situ hybridization and quantitative PCR. The anti-demineralization effect and cytotoxicity of II-6s were evaluated by transverse microradiography and CCK-8 assay, respectively. Repeated exposure of S. mutans to II-6s was performed to assess if II-6s could induce drug resistance. Results: II-6s exhibited antimicrobial activity similar to CHX against S. mutans, S. gordonii and S. sanguinis and significantly inhibited exopolysaccharides production, live bacteria and the demineralizing capability of the 3-species streptococcal biofilms. Besides, II-6s showed reduced cytotoxicity relative to CHX and did not induce drug resistance in S. mutans after 15 passages. Conclusion: - II-6s may serve as a promising part of a successful caries management plan.

Human ClpP protease, a promising therapy target for diseases of mitochondrial dysfunction.

Human caseinolytic protease P (HsClpP), an ATP-dependent unfolding peptidase protein in the mitochondrial matrix, controls protein quality, regulates mitochondrial metabolism, and maintains the integrity and enzyme activity of the mitochondrial respiratory chain (RC). Studies show that abnormalities in HsClpP lead to mitochondrial dysfunction and various human diseases. In this review, we provide a comprehensive overview of the structure and biological function of HsClpP, and the involvement of its dysexpression or mutation in mitochondria for a panel of important human diseases. We also summarize the structural types and binding modes of known HsClpP modulators. Finally, we discuss the challenges and future directions of HsClpP targeting as promising approach for the treatment of human diseases of mitochondrial origin.

Structure-activity relationship study of DEL-22379: ERK dimerization inhibitors with increased safety.

Aberrant activation of ERK signaling pathway usually leads to oncogenesis, and small molecular agents targeting this pathway are impeded by the emergence of drug resistance due to reactivation of ERK signaling. Compound DEL-22379 has been reported to inhibit ERK dimerization which was unaffected by drug-resistant mechanism reactivating the ERK signaling. Here, we discussed a structure-activity relationship study of DEL-22379. Forty-seven analogues were designed and synthesized. Each synthesized compound was biologically evaluated for their inhibitory rates on several tumor cell lines and compounds with high inhibitory rates were further evaluated for IC50 values. The structure-activity relationship of idolin-2-one scaffold and the impact of Z/E configuration on potency were discussed. Potential safety of two synthesized analogues was investigated and in silico docking study of five compounds was performed to understand the structural basis of ERK dimerization inhibition.

Discovery of Novel Peptidomimetic Boronate ClpP Inhibitors with Noncanonical Enzyme Mechanism as Potent Virulence Blockers in Vitro and in Vivo.

Caseinolytic protease P (ClpP) is considered as a promising target for the treatment of Staphylococcus aureus infections. In an unbiased screen of 2632 molecules, a peptidomimetic boronate, MLN9708, was found to be a potent suppressor of SaClpP function. A time-saving and cost-efficient strategy integrating in silico position scanning, multistep miniaturized synthesis, and bioactivity testing was deployed for optimization of this hit compound and led to fast exploration of structure-activity relationships. Five of 150 compounds from the miniaturized synthesis exhibited improved inhibitory activity. Compound 43Hf was the most active inhibitor and showed reversible covalent binding to SaClpP while did not destabilize the tetradecameric structure of SaClpP. The crystal structure of 43Hf-SaClpP complex provided mechanistic insight into the covalent binding mode of peptidomimetic boronate and SaClpP. Furthermore, 43Hf could bind endogenous ClpP in S. aureus cells and exhibited significant efficacy in attenuating S. aureus virulence in vitro and in vivo.

Efficient discovery of novel antimicrobials through integration of synthesis and testing in crude ribosome extract.

By coupling in situ [2+3] Huisgen cycloaddition with an in vitro transcription/translation luminescence assay in a crude ribosomal extract, a robust and accurate high-throughput platform was successfully developed and applied for efficient identification of novel structural types of ribosomal inhibitors with antimicrobial activity against drug-resistant bacteria.

A Novel Small Molecule, ZY354, Inhibits Dental Caries-Associated Oral Biofilms.

Biofilm control is a critical approach to the better management of dental caries. Antimicrobial small molecules have shown their potential in the disruption of oral biofilm and control of dental caries. The objectives of this study were to examine the antimicrobial activity and cytotoxicity of a newly designed small-molecule compound, ZY354. ZY354 was synthesized, and its cytotoxicity was evaluated in human oral keratinocytes (HOK), human gingival epithelial cells (HGE), and macrophages (RAW) by CCK-8 assays. Minimal inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), minimum biofilm inhibition concentrations (MBICs), and minimum biofilm reduction concentrations (MBRCs) of ZY354 against common oral streptococci (i.e., Streptococcus mutans, Streptococcus gordonii, and Streptococcus sanguinis) were determined by microdilution method. The exopolysaccharide (EPS)/bacterium ratio and the dead/live bacterium ratio in the ZY354-treated multispecies biofilms were determined by confocal laser scanning microscopy, and the microbial composition was visualized and quantified by fluorescent in situ hybridization and quantitative PCR (qPCR). The demineralizing activity of ZY354-treated biofilms was evaluated by transverse microradiography. The results showed that ZY354 exhibited low cytotoxicity in HOK, HGE, and RAW cells and exhibited potent antimicrobial activity against common oral streptococci. The EPS and the abundance of S. mutans were significantly reduced after ZY354 treatment, along with an increased dead/live microbial ratio in multispecies biofilms compared to the level with the nontreated control. The ZY354-treated multispecies biofilms exhibited reduced demineralizing activity at the biofilm/enamel interface. In conclusion, the small-molecule compound ZY354 exhibits low cytotoxicity and remarkable antimicrobial activity against oral streptococci, and it may have a great potential in anticaries clinical applications.

Discovery of hybrids of indolin-2-one and nitroimidazole as potent inhibitors against drug-resistant bacteria.

With antibiotics resistance developing rapidly, new antibacterial agents are needed to be discovered. We readily synthesized 11 indolin-2-one compounds and found a hybrid of indolin-2-one and nitroimidazole 3-((1-methyl-5-nitro-1H-imidazol-2-yl)methylene)indolin-2-one to be effective on Staphylococcus aureus strains. Six derivatives of this compound were further designed and synthesized in order to enhance its efficacy. After a second turn of structural refinement, a novel hybrid of indolin-2-one and nitroimidazole 3-((1-methyl-5-nitro-1H-imidazol-2-yl)methylene)-5-nitroindolin-2-one with a nitro group on C-5 position of indolin-2-one was shown to exhibit remarkable antibacterial activities with a low MIC value against MRSA ATCC 33591. Besides, this molecule demonstrated its potency on Gram-negative bacteria and VRE strain. The time-killing curve experiment showed its good bactericidal activity. Low hemolytic rate suggested its promising safety profile.

Effects of fifth day (D5) or sixth day (D6) frozen-thawed blastocysts on neonatal outcomes.

This study aimed to compare the neonatal outcomes of transplanted fifth day (D5) or sixth day (D6) frozen-thawed blastocysts, aiming to provide guidance when choosing blastocyst recovery methods. The clinical data of 1109 patients that were performed for recovered blastocyst transplantation, as well as the data of 515 patients who had already delivered were analyzed retrospectively. The patients were divided into single- or twins-birth groups according to blastocyst formation time (D5 or D6) and the number of fetus(es). The implantation rate, clinical pregnancy rate and live birth rate of the D5 group were all significantly higher than those in the D6 group (P 0.05). In conclusion, the implantation rate, clinical pregnancy rate and live birth rate in the D5 group were all significantly higher than that in the D6 group. The birth weight at D6 was prone to be heavier no matter the birth group, and the sex ratio in the D5 group was higher than that at D6, the difference in neonatal outcomes between the two groups was not statistically significant.

Pregnancy Outcomes of In Vitro Fertilization with or without Ovarian Hyperstimulation Syndrome: A Retrospective Cohort Study in Chinese Patients.

BACKGROUND: The effect of ovarian hyperstimulation syndrome (OHSS) on pregnancy outcomes of in vitro fertilization (IVF) patients is still ambiguous. This study aimed to analyze pregnancy outcomes of IVF with or without OHSS in Chinese patients. METHODS: A retrospective cohort study was undertaken to compare pregnancy outcomes between 190 women with OHSS and 197 women without OHSS. We examined the rates of clinical pregnancy, multiple pregnancies, miscarriage, live birth, preterm delivery, preterm birth before 34 weeks' gestation, cesarean delivery, low birth weight (LBW), and small-for-gestational age (SGA) between the two groups. Odds ratios (OR s) and 95% confidence intervals (CI s) of measure of clinical pregnancy were also analyzed. RESULTS: The clinical pregnancy rate of OHSS patients was significantly higher than that of non-OHSS patients (91.8% vs. 43.5%, P < 0.001). After controlling for drug protocol and causes of infertility, the adjusted OR s of moderate OHSS and severe/critical OHSS for clinical pregnancy were 4.65 (95% CI, 1.86-11.61) and 5.83 (95% CI, 3.45-9.86), respectively. There were no significant differences in rates of multiple pregnancy (4.0% vs. 3.7%) and miscarriage (16.1% vs. 17.5%) between the two groups. With regard to ongoing clinical pregnancy, we also found no significant differences in the rates of live birth (82.1% vs. 78.8%), preterm delivery (20.9% vs. 17.5%), preterm birth before 34 weeks' gestation (8.6% vs. 7.9%), cesarean delivery (84.9% vs. 66.3%), LBW (30.2% vs. 23.5%), and SGA (21.9% vs. 17.6%) between the two groups. CONCLUSION: OHSS, which occurs in the luteal phase or early pregnancy in IVF patients and represents abnormal transient hemodynamics, does not exert any obviously adverse effect on the subsequent pregnancy.

Factors Associated with Effectiveness of Treatment and Reproductive Outcomes in Patients with Thin Endometrium Undergoing Estrogen Treatment.

BACKGROUND: Thin endometrium is associated with poor reproductive outcomes; estrogen treatment can increase endometrial thickness (EMT). The aim of this retrospective cohort study was to investigate the factors influencing the effectiveness of estrogen treatment and reproductive outcomes after the treatment in patients with thin endometrium. METHODS: Relevant clinical data of 101 patients with thin endometrium who had undergone estrogen treatment were collected. Possible factors influencing the effectiveness of treatment were analyzed retrospectively by logistic regression analysis. Eighty-seven infertile women without thin endometrium who had undergone assisted reproduction served as controls. The cases and controls were matched for age, assisted reproduction method, and number of embryos transferred. Reproductive outcomes of study and control groups were compared using Student's t-test and the Chi-square test. RESULTS: At the end of estrogen treatment, EMT was ≥8 mm in 93/101 patients (92.1%). Effectiveness of treatment was significantly associated with maximal pretreatment EMT (P = 0.017) and treatment duration (P = 0.004). The outcomes of assisted reproduction were similar in patients whose treatment was successful in increasing EMT to ≥8 mm and the control group. The rate of clinical pregnancy in patients was associated with the number of good-quality embryos transferred in both fresh (P = 0.005) and frozen-thawed (P = 0.000) embryo transfer cycles. CONCLUSIONS: Thinner EMT before estrogen treatment requires longer treatment duration and predicts poorer treatment outcomes. The effectiveness of treatment depends on the duration of estrogen administration. Assisted reproductive outcomes of patients whose treatment is successful (i.e., achieves an EMT ≥8 mm) are similar to those of controls. The quality of embryos transferred is an important predictor of assisted reproductive outcomes in patients treated successfully with exogenous estrogen.

[Evaluation the efficacy and safety of estradiol and drospirenone tablets in the treatment of menopausal symptoms among postmenopausal Chinese healthy women:a randomized, multi-center, double-blind, placebo-controlled clinical study].

OBJECTIVE: To study the efficacy and safety of estradiol and drospirenone tablets (Angeliq) in treatment of menopausal symptoms among postmenopausal Chinese healthy women. METHODS: Total 244 postmenopausal Chinese healthy women who had moderate to severe hot flushes were randomly assigned into estradiol and drospirenone (observation group, n = 183) or placebo group (n = 61) by the ratio of 3:1 for 16 weeks in this randomized multi-center double-blind placebo-controlled study. During the trial, the follow-up visits were conducted at week 4, 8, 12, 16 of treatment and 2 weeks after treatment respectively. Height, weight, vital signs, hot flushes, other relevant menopausal symptoms and vaginal bleeding were observed in each follow-up visit, while the clinical global impression scale was assessed at 16 weeks as well. RESULTS: It showed that hot flushes were reduced significantly more in observation group than that in placebo group (P < 0.01), although both treatments were effective. The absolute values of mean severity index of total hot flushes decreased by -0.6 ± 0.5 in observation group and -0.4 ± 0.4 in placebo group from baseline respectively, which reached significant difference (P < 0.05). However, the absolute values of mean severity index of moderate to severe hot flushes decreased by -0.6 ± 0.8 in observation group and -0.3 ± 0.6 in placebo group from baseline respectively, which had no significant difference (P > 0.05). After 16 weeks treatment, it also showed that estradiol and drospirenone had significant better efficacy than placebo on moderate to severe sweating, vaginal dryness and clinical global impression scale (P < 0.01). During the trial, blood pressure in observation group was stable. The rate of vaginal bleeding in observation group was higher than that in the placebo group, especially during the week 4 to week 8 when 48.9% (87/178) in observation group and 10.7% (6/56) in placebo group of patients bled. Although the cumulative amenorrhea rate of observation group was lower than that of placebo group in each cycle (28 days), it increased gradually along with duration of the treatment. The commonest adverse event in observation group was breast tenderness which accounted for 12.0% (22/183). The level of serum potassium was in the normal range in observation group mostly.Meanwhile, the other adverse events rate was low. Serious adverse events reported in this trial were assessed as not study drug related or as unlikely study drug related. CONCLUSION: Estradiol and drospirenone tablets which could effectively alleviate menopausal symptoms in postmenopausal Chinese healthy women is a novel hormone replacement therapy regimen with high safety and efficacy.

Gender verification in athletes with disorders of sex development.

Disorders of sex development (DSD) are most controversial issue in gender verification of athletes. To make a more scientific, accurate and humanitarian decision for athletes is the target of gender verification. In this article, we evaluate the used methods of gender verification in athletes, recommend a useful simplified classification of DSD and propose a comprehensive etiological diagnostic system based on this classification for gender verification in athletes.

[Identification of potential neoplastic risk in gonadal development abnormality with Y chromosome of 79 cases].

OBJECTIVE: To identify the potential neoplastic risk in gonadal development abnormality with Y chromosome. METHODS: Inquiries about the illness history were made. Lymphocyte chromosomal karyotype of peripheral blood was analyzed. Sex determining region Y gene and relative steroids and enzymes were detected. Gonadal site was examined through medical imaging. Gonadal excision was performed by laparotomy or laparoscopy. Pathological examinations were done on all of the specimens. RESULTS: Among 41 cases of androgen insensitive syndrome, spermatogenic cell neoplasm occurred in 1 patient, sertoli cell tumor in 2, and interstitial cell hyperplasia in 5. Among 14 cases of 17 alpha-hydroxylase deficiency (XY) syndrome, one was sertoli cell tumor, and one was sertoli cell hyperplasia. In 4 cases of XY pure gonadal dysgenesis, one was gonadoblastoma with dysgerminoma. One of 16 cases of XO/XY gonadal dysgenesis was spermatogenic cell neoplasm with agenda cell tumor. Four cases of testes degeneration were all with dysgenetic testes. All of the gonadoblastoma and germ-cell tumor were located in the pelvis. Tumors occurred mostly during 15 years of age to 32 years. CONCLUSIONS: The gonads of XY pure gonadal dysgenesis has high risks of gonadoblastoma and germ-cell tumor. The older the onset age after puberty, the higher the malignancy risk is. Once diagnosed, bilateral gonads should be excised as soon as possible.

Social and behavior factors related to aged Chinese women with osteoporosis.

BACKGROUND: Women aged >or=65 years are screened routinely for osteoporosis in the developed world and identifying risk factors for osteoporosis should be highlighted in developing countries such as the People's Republic of China. In the present study, possible factors related to the occurrence of primary osteoporosis in aged Chinese women were explored. METHODS: On appointed attendance at a menopausal outpatient clinic, generally healthy Chinese women aged >or=65 years were requested to complete a self-administered questionnaire. Bone mineral density at the left femur region was assessed using dual-energy X-ray absorptiometry, by which subjects were categorized as osteoporotic (group A), osteopenic (group B) or normal (group C). If a prevalent spinal fracture was affirmed, patients in group B were reclassified into group A. Non-conditional logistic regression analysis was applied to the calculate odds ratio (OR) of being in group A against the other two groups in terms of social and behavior factors (including education, past occupation, work quality, marriage status, income, self-rated health status, amount of daily physical activity, cigarette smoking, time watching television, and consumption of milk, soy products and tea). RESULTS: Three hundred and twenty-four participants were eligible (77 in group A, 137 in group B, 110 in group C). There were significant differences in age, height, weight, menopausal age and years since menopause among groups. Compared with subjects with amount of daily physical activity <0.5 h in group A, the OR for women in group C was 0.357 (95% confidence interval (CI) 0.144-0.889) for 0.5-1 h, 0.314 (95% CI 0.126-0.780) for 1-2 h and 0.278 (95% CI 0.080-0.968) for >2 h of daily physical activity. When adjusted for age and weight, however, the difference was not significant. Other factors did not reach statistical significance. CONCLUSION: The development of osteoporosis in aged women was affected by both menopause and aging. The known related factors could help to identify susceptible subjects in aged Chinese women for either further assessment or treatment.

Changes of total content of serum magnesium in elderly Chinese women with osteoporosis.

OBJECTIVE: To explore whether the serum levels of magnesium (Mg) and calcium (Ca) differ between osteoporotic and nonosteoporotic elderly Chinese women. METHODS: Using WHO classification criteria based on bone mineral density (BMD), general healthy Chinese women older than 65 yr were classified as osteoporosis (OP), osteopenia, and normal group according to the T-score of the femur neck. Then their physical characteristics, serum levels of magnesium (sMg), calcium (sCa), and other biochemical measurements were analyzed. RESULTS: Altogether, 324 subjects were included in the final analysis with 77 in OP, 137 in osteopenia, 110 in normal group. The level of sMg in women with OP is significantly higher (0.91+/-0.11 mmol/L) than both the osteopenia (0.88 +/- 0.09 mmol/L) and the normal (0.877+/-0.08 mmol/L) even after being adjusted for both age and body mass index (BMI), which might result from potentially low levels of sCa. sMg inversely related to sCa in subjects with OP (r=-0.240, p=0.038), whereas the total levels of sCa and sMg kept relatively steady. CONCLUSION: High content of sMg and potentially low content of sCa could be a feature of the serum profile of elderly Chinese women with OP, the clinical significance of which needs further elucidation. Supplementation of Mg for elderly Chinese women with OP did not appear to be necessary.