[Current status of pubertal sexual characteristics development of 2 704 girls aged 6-18 years in Tongzhou District of Beijing]

Objective: To understand the current status of pubertal sexual characteristics development of girls aged 6-18 years in Tongzhou District of Beijing and to compare the differences in sexual characteristics development among girls characterized as thin, normal, overweight, and obese. Methods: A cross-sectional survey was conducted among 2 844 girls aged 6-18 years in Tongzhou District of Beijing from September 2022 to July 2023. The developmental stages of breast and pubic hair were assessed on site, and menarche status was inquired. Weight and height were measured. The girls were subsequently characterized into thin, normal, overweight and obese groups. Basic information (including family and personal history) was obtained through questionnaires. Probit probability unit regression was applied to calculate the age of each Tanner stage of sexual characteristics development and the age of menarche. The χ2 test was applied to compare the counting data between two or multiple groups. Results: A total of 2 844 girls were surveyed and 2 704 girls met the inclusion criteria, resulting in a valid response rate of 95.1%. Among these girls, 1 105 (40.9%) were aged 6-9 years, 1 053 (38.9%) were aged 10-13 years, and 546 (20.2%) were aged 14-18 years. The of height-for-age Z-score (HAZ), weight-for-age Z-score (WAZ), and body mass index-for-age Z-score (BAZ) were 0.46(-0.23,1.16), 0.69(-0.16,1.67), and 0.67(-0.27,1.73) respectively. The prevalences of thin, overweight, and obesity were respectively 1.7% (45/2 704), 17.3% (467/2 704), and 19.9% (538/2 704), respectively. There were 45 girls in the thin group, 1 654 girls in the normal weight group, 1 005 girls in the overweight and obesity group. The age of Tanner stage breast 2 (B2), Tanner stage pubic hair 2 (P2), and menarche was 9.0 (95%CI 8.9-9.1), 10.5 (95%CI 10.4-10.6), and 11.4 (95%CI 11.3-1.5) years, respectively. The current status of breast and pubic hair maturity in girls with pubertal development shows that 64.6% (1 211/1 874) of these girls had breast development preceding pubic hair development, 32.4% (607/1 874) had concurrent breast and pubic hair development, and 3.0% (56/1 874) had pubic hairs development preceding breast development. The interval age between B2 and B5 was 4.7 (95%CI 4.6-4.8) years, between P2 and P5 was 4.5 (95%CI 4.4-4.6) years, and between B2 and menarche was 2.4 (95%CI 2.3-2.5) years. The ages of sexual characteristics development in overweight and obese groups were earlier than that in normal and thin groups. The ages of B2 in thin, normal, overweight, and obese groups were 10.0 (95%CI 9.5-10.6), 9.3 (95%CI 9.2-9.4), and 8.6 (95%CI 8.4-8.7) years, respectively. The age of menarche in thin, normal, overweight, and obese groups were 13.1 (95%CI 12.4-13.7), 11.6 (95%CI 11.4-11.7), and 11.1 (95%CI 11.0-11.2) years, respectively. The interval ages between B2 and B5 and between P2 and P5 was 4.5 and 4.1 years, respectively in the overweight and obese groups, and those in normal group and thin group was 4.7 and 4.5 years, 4.6 and 4.7 years, respectively. Conclusions: The ages of sexual characteristics development and menarche tend in Tongzhou District of Beijing to be earlier than that being reported of Beijing's survey 20 years ago. Girls characterized as overweight and obese not only start puberty at an earlier age than girls of normal weight, but also have a shorter developmental process.

[Laparoscopic circular stapled gastrointestinal anastomosis using novel device of sealed cap access after total laparoscopic gastrectomy]

Intracorporeal classic gastrointestinal anastomosis using circular stapler in totally laparoscopic gastrectomy (TLG) for gastric cancer requires intracorporeal anvil placement and suitable access for introduction of the circular stapler to the abdominal cavity without gas leak. The novel techniques for anvil placement have been updated, but there is no progress for proper access for circular stapler. In the study, intracorporeal circular-stapled gastrointestinal anastomosis were successfully accomplished using a novel device of sealed cap access with a central hole (WLB-60/70-60/100, Wuhan Widerep Medical Instrument Co.,Ltd, China) customized to the incision protection retractor for the simple and accessible introduction of the circular stapler and anvil under the optimal maintenance of pneumoperitoneum pressure in TLG. In these 3 cases, there was no gas leakage and the pneumoperitoneum was well maintained when performing the gastrointestinal anastomosis, and there was no transition to laparotomy or other anastomosis techniques. The result suggests that the sealed cap access could be a novel choice for introduction of the circular stapler to the abdominal cavity in order to obtain laparoscopic circular-stapled gastroin-testinal anastomosis in TLG.

Inhibition of miR-126 protects chondrocytes from IL-1β induced inflammation via upregulation of Bcl-2

OBJECTIVES

The aim of this study was to investigate the role of miR-126 in the development of osteoarthritis, as well as the potential molecular mechanisms involved, in order to provide a theoretical basis for osteoarthritis treatment and a novel perspective for clinical therapy.

METHODS

Human chondrocyte cell line CHON-001 was administrated by different doses of interleukin (IL)-1β to simulate inflammation. Cell viability, migration, apoptosis, IL-6, IL-8, and tumour necrosis factor (TNF)-α expression, as well as expression of apoptosis-related factors, were measured to assess inflammation. miR-126 expression was measured by quantitative polymerase chain reaction (qPCR). Cells were then transfected with miR-126 inhibitor to assess the effect of miR-126 on IL-1β-injured CHON-001 cells. Expression of B-cell lymphoma 2 (Bcl-2) and the activity of mitogen-activated protein kinase (MAPK) / Jun N-terminal kinase (JNK) signaling pathway were measured by Western blot to explore the underlying mechanism through which miR-126 affects IL-1β-induced inflammation.

RESULTS

After IL-1β administration, cell viability and migration were suppressed while apoptosis was enhanced. Expression of IL-6, IL-8, and TNF-α were all increased, and miR-126 was upregulated. In IL-1β-administrated CHON-001 cells, miR-126 inhibitor suppressed the effect of IL-1β on cell viability, migration, apoptosis, and inflammatory response. Bcl-2 expression was negatively regulated with miR-126 in IL-1β-administrated cells, and thus affected expressions of phosphorylated MAPK and JNK.

CONCLUSION

IL-1β-induced inflammatory markers and miR-126 was upregulated. Inhibition of miR-126 decreased IL-1β-induced inflammation and cell apoptosis, and upregulated Bcl-2 expression via inactivating the MAKP/JNK signalling pathway.Cite this article: C. D. Yu, W. H. Miao, Y. Y. Zhang, M. J. Zou, X. F. Yan. Inhibition of miR-126 protects chondrocytes from IL-1β induced inflammation via upregulation of Bcl-2. Bone Joint Res 2018;7:414-421. DOI: 10.1302/2046-3758.76.BJR-2017-0138.R1.

Fibroblast growth factor receptor 4 Gly388Arg polymorphism associated with severity of gallstone disease in a Chinese population

The etiology of gallstone disease is multifactorial; supersaturation of bile with cholesterol is a primary cause for gallstone formation. In previous studies, we found that fibroblast growth factor receptor 4 (FGFR4) plays an important role in maintaining bile acid homeostasis by regulating the expression of cholesterol 7α-hydroxylase (CYP7A1), a rate-limiting enzyme for bile acid biosynthesis. The Gly388Arg (G-388R) polymorphism of FGFR4 affects stabilization and activation of FGFR4. Consequently, we studied the FGFR4 gene as a candidate gene for genetic susceptibility to gallstone disease. We found that overexpression of FGFR4, especially the G-388R mutant of FGFR4, inhibits luciferase activity of CYP7A1 reporter in HepG2 cells, indicating that the G-388R mutant of FGFR4 may have greater inhibitory activity against bile acid biosynthesis. To investigate the association of FGFR4 polymorphism with gallstone disease, 117 patients with gallstone disease and 457 controls were genotyped for FGFR4 polymorphism G-388R by PCR-RFLP. Although the incidence of gallstone disease was not greater in patients with the FGFR4 RR genotype, the ratio of gallstone patients with acute cholecystitis in the FGFR4 RR genotype (42%) was significantly higher than that in other genotypes of FGFR4 (P = 0.019). In conclusion, the FGFR4 polymorphism is a genetic risk factor contributing to aggravation of gallstone disease.

Prevention of spinal cord injury after transient aortic clamping with tissue factor pathway inhibitor

BACKGROUND

Lower limb paralysis that occurs in 11% of patients after treatment of thoracic and thoracoabdominal aortic aneurysms is unpredictable and at present not preventable. The proposed cause for the neurologic changes is believed to be spinal cord ischemia combined with ischemia/reperfusion injury. Recombinant tissue factor pathway inhibitor (rTFPI), a multivalent Kunitz-type inhibitor that binds to tissue factor-VIIa complex, was evaluated.

METHODS

The effectiveness of rTFPI as an agent to limit spinal cord ischemia/reperfusion injury was studied in a rabbit spinal cord made ischemic for 20 minutes. rTFPI or phosphate-buffered saline solution (control) was given in randomized blinded fashion at the onset and conclusion of ischemia. Animals underwent neurologic evaluation at 24 hours in a blinded fashion with a modified Tarlov Scale to rate the lower limb paralysis (score of 4 = normal function, score of 0 = complete paralysis).

RESULTS

Seventy-five percent of the TFPI-treated animals had Tarlov scores of 3 to 4, whereas only 29% of the animals treated with phosphate-buffered saline solution had such scores (p < 0.0014). Spinal cord histologic findings correlated with the neurologic findings.

CONCLUSIONS

We believe that TFPI has unique inhibitory properties that make it an effective agent in limiting postoperative paraplegia associated with spinal ischemia.

Effect of cryoprotectants on freezing, lyophilization, and storage of lyophilized recombinant alpha 1-antitrypsin formulations

Stabilizing effect of several commonly used cryoprotectants, namely lactose, sucrose, and polyvinyl-pyrrolidone (PVP), on recombinant alpha 1-antitrypsin (rAAT) were studied. A solution of rAAT in a phosphate/citrate buffer (pH 7.0) was made with and without a given cryoprotectant and filled into small vials. The vials were frozen on shelf, at -40 degrees C in a lyophilizer. At the end of the freezing cycle, half of the batch was thawed at ambient temperature and the other half was continued to the completion of lyophilization. Sample vials taken before freezing, after thawing, and after lyophilization were analyzed for total rAAT protein, monomeric content, and elastase-inhibitory activity. Results indicated that neither freeze-and-thaw nor lyophilization caused any damage to rAAT, contrary to what was generally believed. The control formulation (i.e., without a cryoprotectant) performed as good as those containing cryoprotectants. Freezing rates and protein concentration in formulation did not influence the stability of rAAT either. Lyophilized rAAT samples retained the activity and purity during the 12 month stability period, at room temperature and 2-8 degrees C.

Transforming growth factor-alpha (TGF-alpha) in a semisolid dosage form: preservative and vehicle selection

The selection of an ideal semisolid vehicle for growth factors presents a challenge. Some antimicrobial agents are known to delay wound healing. The objective of this investigation was to identify appropriate preservatives and vehicles for TGF-alpha. Criteria for acceptance are noninterference with the mitogenic activity of TGF-alpha as well as adequate product preservation. Vehicles considered were o/w creams, ointments, and a gel. Combinations of six preservatives were tested. Selection was determined using both microbial preservative challenge and TGF-alpha mitogenic assay. In the former, 10 species of microorganisms were inoculated into formulation samples. At selected time intervals, it was determined whether colonies decreased, increased, or remained constant. In the mitogenic assay, samples of either preservatives or formulation prototypes were introduced to TGF-alpha-stimulated fibroblast cell cultures. Mitogenesis was determined by measuring 3H-dThd uptake into newly synthesized DNA. As preservatives, sorbic acid and quaternium-15 appear to satisfy both selection criteria. A thermosetting gel appears most promising as vehicle.

Physical stability of a recombinant alpha 1-antitrypsin injection

Physical stability of a recombinant alpha 1-antitrypsin (rAAT) injection solution, namely, loss of rAAT to particulate formation was studied. The rAAT injection solution (1.0 mg/ml, pH 7.5, triple buffer of phosphate, Tris, and glycine, 0.075 M each) was filtered through a 0.2-micron filter and packaged in individual vials with rubber stoppers and aluminum seals. The vials were stored at 90, 80, 60, 45, 35, and 25 degrees C, and samples taken at predetermined time intervals for each storage condition. Each sample was then filtered through a 0.2-micron filter to remove particulates. The filtrate was then assayed for total protein by the biuret-phenol method. A typical first-order loss of rAAT was observed. Data were fitted to a first-order kinetics, and the shelf life (defined as t90, the time for the product to reach 90% remaining) was calculated from the resultant rate constant. The shelf lives were plotted against reciprocals of storage temperatures (a modified Arrhenius plot). A linear regression line (r = 0.9831) was drawn through the data points and extrapolated to 4 degrees C. At 4 degrees C, the predicted shelf life of the rAAT solution is 5.1 months. In real life, a batch of the rAAT solution showed that 61% of the rAAT remained in the filtrate after 18 months of storage at 4 degrees C. The observed stability compares fairly well with the predicted value of 69% for the same duration of storage at 4 degrees C. From the slope of the linear regression line, the activation energy for the particulate formation of the rAAT was calculated to be 19 kcal. This value is comparable to the activation energy of 20 kcal for ovalbumin denaturation reaction reported by Simpson and Kauzmann.

Cascade impactor method for the droplet size characterization of a metered-dose nasal spray

A relatively rapid and simple method was developed to characterize the droplet size of a metered-dose nasal spray. The study primarily concerned the measurement of the relative proportion of small to large droplets. A small droplet could potentially reach bronchi or alveoli, depending on its size, and was therefore undesirable for the topical corticosteroid therapy of rhinal disease. The nasal spray was a solution of flunisolide, a topically active anti-inflammatory corticosteroid, administered by a manually operated, metered-dose pump spray system. The method utilized a cascade impactor fitted with a glass chamber; the cascade impactor collected and sized droplets into six fractions 0.5-16 micron in diameter, while the glass chamber collected droplets greater than 16 micron in diameter as another fraction. Results showed that the majority of the spray droplets deposited in the glass chamber. Less than 0.5% by weight of the spray dose was delivered in droplets less than 8 micron aerodynamic diameter. These results are in good agreement with the droplet size distribution obtained by laser holography. The cascade impactor method showed that the number of undesirable small droplets produced by the flunisolide nasal spray unit was negligible. The method can be used with other aerosols where there is a similar concern for the inhalation of small particles.

Physical model evaluation of topical prodrug delivery--simultaneous transport and bioconversion of vidarabine-5'-valerate III: Permeability differences of vidarabine and n-pentanol in components of hairless mouse skin

The permeation behavior of 3H-vidarabine (3H-9-beta-D-ara-binofuranosyladenine) and 14C-n-pentanol through different strata of hairless mouse skin was studied using a diffusion cell at 37 degrees under steady-state conditions. Partition coefficients for the skin components verus 0.9% aqueous NaCl solution also were obtained. Various skin preparations including full-thickness skin, cellophane-stripped skin, and dermis membranes of different thicknesses were employed. The dermis membranes were considered to be diffusionally homogenous, and the product of the permeability coefficient and the thickness was taken as the apparent diffusivity. The apparent diffusivities for both compounds investigated were independent of thickness. Therefore, it was concluded that the molecular diffusivity is constant throughout the dermis. Comparisons of permeability coefficients in various strata of the skin revealed that, while the stratum corneum is the major diffusional barrier, the epidermis appears to be significantly less permeable than the dermis.

Physical model evaluation of topical prodrug delivery--simultaneous transport and bioconversion of vidarabine-5'-valerate V: Mechanistic analysis of influence of nonhomogeneous enzyme distributions in hairless mouse skin

The mathematical problem of simultaneous transport and metabolism in the case of nonuniform enzyme distributions in the skin was solved, and the solutions were used for analyzing experimental data. Experimental data were obtained from permeation experiments with 3H-vidarabine and its 5'-valerate using cellophane tape-stripped hairless mouse skin. Results of the analyses revealed that the esterase activity was four to nine times higher in the epidermis than in the dermis, whereas the deaminase activity was about the same in the two strata. These results were in good agreement with independent experiments using tissue homogenates. The enzyme distributions and the previously reported diffusivities were employed in generating concentration profiles for the prodrug and the drug in the skin. These results may be used in predicting the possible therapeutic effect of the prodrug when it is topically applied.

Physical model evaluation of topical prodrug delivery--simultaneous transport and bioconversion of vidarabine-5'-valerate IV: Distribution of esterase and deaminase enzymes in hairless mouse skin

A semiquantitative assessment of estrase and deaminase distributions in hairless mouse skin was performed in vitro. The enzyme activities were quantified using 3H-vidarabine and tis 5'-valerate as the substrates. Full-thickness skin of the hairless mouse was cut into two halves, and each half was homogenized in pH 7.4 buffer. BQOTH THE SUPERNATE AND THE RESIDUE OF THE HOMOGENATE were assayed for esterase and deaminase activities. Results show that the outer half-thickness of the skin contained more esterase but slightly less deaminase than the other half. The characteristics of the esterase and the deaminase reactions also were studied employing the crude enzyme extract; these reactions were essentially irreversible. The deaminase reaction was in the linear region of Michaelis-Menten kinetics for substrate concentrations up to 4.5 x 10(-5) M.

Physical model evaluation of topical prodrug delivery-simultaneous transport and bioconversion of vidarabine-5'-valerate II: Parameter determinations

Results of initial studies on methods for determining various model parameters are reported. By employing excised hairless mouse skin in a diffusion cell system, numerous model parameter values were deduced. The stratum corneum permeability was estimated from steadystate fluxes with preparations of heat-separated epidermal membranes. Determinations of dermis diffusivities and enzyme rate constants in situ involved considering the simultaneous transport and the enzyme processes and factoring the diffusivities and enzyme rate constants from the overall kinetics. Dermal diffusivities were on the order of 10-6 cm2/sec for vidarabine and its 5'-valerate ester. The enzyme rate constants were 1.70 x 10-3 sec-1 for the esterase and 8.68 x 10-3 sec-1 for the deaminase.

Physical model evaluation of topical prodrug delivery-simultaneous transport and bioconversion of vidarabine-5'-valerate I: Physical model development

A physical model approach to the topical delivery of a vidarabine ester prodrug was investigated. It involved modeling, theoretical simulations, experimental method development for factoring and quantifying parameters, and, finally, employment of the deduced parameters to determine the steady-state species fluxes and concentration profiles in the target tissue. The present report describes the physical modeling and theoretical simulation aspects. The physical model for the simultaneous transport and bioconversion of a topically delivered prodrug was formulated assuming homogeneous enzyme distributions and constant diffusivities in the membrane. The mathematical problem was solved, and the solution yielded concentration profiles and fluxes of all species in the biomembrane. These results provided the prevailing levels of the prodrug, the drug, and the metabolite at the target site and the transport rates of all species into the bloodstream. Computations of concentration profiles and fluxes were carried out for a reasonable range of the parameters. The relative activities of the esterase and the deaminase enzymes, as well as the stratum corneum permeabilities, were important in influencing the concentration profiles and fluxes of all species.