Protective effect of an egg yolk-derived immunoglobulin (IgY) against Prevotella intermedia-mediated gingivitis.

AIMS: To investigate the effects of an egg yolk-derived immunoglobulin (IgY) specific to Prevotella intermedia in vitro and in vivo. METHODS AND RESULTS: An IgY specific to P. intermedia was produced by immunizing hens with formaldehyde-inactivated P. intermedia and showed high titres when subjected to an ELISA. The obtained IgY inhibited the growth of P. intermedia in a dose-dependent manner at concentrations from 1 to 20 mg ml(-1) in Center for Disease Control and Prevention liquid medium. Forty rats were challenged with P. intermedia on gingivae and then randomly divided into four groups, which were syringed respectively with phosphate-buffered saline, 1 mg ml(-1) of tinidazole, 20 mg ml(-1) of nonspecific IgY and 20 mg ml(-1) of the IgY specific to P. intermedia at a dosage of 300 µl per day. Gingival index (GI), plaque index (PI), bleeding on probing (BOP), counts of white blood cell (WBC) and histopathological slide of the gums were measured after treatment for 15 days. The gingivitis rats treated with the IgY specific to P. intermedia showed significantly decreased GI, PI, BOP and WBC (P < 0·05). Gum histopathology of the treated rats demonstrated a superior protective effect of the specific IgY on P. intermedia-mediated gingivitis. CONCLUSIONS: A new immunoglobulin specific to P. intermedia was developed from egg yolk. This specific IgY can dose-dependently inhibit the growth of P. intermedia and protect rats from gingivitis induced by P. intermedia. SIGNIFICANCE AND IMPACT OF THE STUDY: The new IgY has potential for the treatment of P. intermedia-mediated gingivitis.

[Aesthetic reconstruction of the scar contracture deformity in chin and neck with expanded flaps based on the "MRIS" principle].

Objective: The surgical reconstruction strategy for scar contracture deformity in chin and neck was explored, aiming to obtain better aesthetic outcome. Methods: A retrospective observational study was conducted. From December 2017 to April 2021, 34 patients with scar contracture deformity in chin and neck after burns were hospitalized in the Department of Plastic Surgery of the First Affiliated Hospital of Army Medical University (the Third Military Medical University), aged 12-54 years, including 13 males and 21 females, 4 cases with chin affected only, 7 cases with neck affected only, and 23 cases with both chin and neck affected. The scar areas were 48-252 cm2. All the patients were treated by operation with expanded flaps, following the "MRIS" principle of matching of the color and thickness of the repair flaps (match), reconstructing of the aesthetic features of subunits (reconstruction), design of incision according to the plastic principle (incision), and prevention of the surgical incision scar (scar). The rectangular or kidney shaped skin and soft tissue expander (hereinafter referred to as the expander) with rated capacity of 80-400 mL was embedded in the first stage, which was routinely expanded to 3-5 times of the rated capacity of the expander. In the second stage, scar resection and expanded flap excision were performed to repair the secondary wound, and the flap donor site was sutured directly. The expansion ratio of the expander (with average value being calculated), the type of flaps used, the reconstruction of local aesthetic morphology, the appearance of postoperative incision, the survival of flap, and the situation of donor and recipient sites observed during follow-up were recorded. Results: Among the 34 patients, the average expansion ratio of the implanted expander was 3.82 times of the rated capacity of the expander. Three cases were repaired by the expanded local pedicled flap only, 19 cases by the expanded shoulder and/or chest perforator pedicled flap only, 10 cases by the expanded local pedicled flap combined with the expanded shoulder and/or chest perforator pedicled flap, and 2 cases by the expanded local pedicled flap combined with the expanded free flap of the second intercostal perforator of internal thoracic artery. After scar resection, the shapes of lower lip and chin-lip groove were reconstructed in 10 cases, chin process reconstruction and chin lengthening were performed in 16 cases, and the cervico-mental angle and mandibular margin contour were reconstructed in 28 cases. The surgical incision was concealed, most of which were located at the natural junction or turning point of the chin and neck subunits. The vertical incision of neck was Z-shaped or fishtail-shaped. All the expanded flaps in 34 patients survived after operation, of which 8 patients had minor necrosis at the edge or tip of the expanded flaps 1-3 days after operation and healed after dressing change. During the follow-up of 3-18 months, little difference in color and thickness between the expanded flap and the skin of chin and neck was observed, and the aesthetic shape of chin and neck was significantly improved, with mild scar hyperplasia of surgical incision. Conclusions: Reconstruction of scar contracture deformity in chin and neck by using expanded flaps based on the "MRIS" principle is beneficial to improve the quality of surgery and achieve better aesthetic outcome.

An antifungal protein from the pea Pisum sativum var. arvense Poir.

An antifungal protein with a molecular mass of 11 kDa and a lysine-rich N-terminal sequence was isolated from the seeds of the pea Pisum sativum var. arvense Poir. The antifungal protein was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel blue gel and CM-cellulose. It exerted antifungal activity against Physalospora piricola with an IC50 of 0.62 microM, and also antifungal activity against Fusarium oxysporum and Mycosphaerella arachidicola. It inhibited human immunodeficiency virus type 1 reverse transcriptase with an IC50 of 4.7 microM.

In vitro degradation and mechanical integrity of Mg-Zn-Ca alloy coated with Ca-deficient hydroxyapatite by the pulse electrodeposition process.

The key to manufacturing magnesium-based alloys that are suitable as biodegradable orthopaedic implants is how to adjust their degradation rates and mechanical integrity in the physiological environment. In this study, to solve this challenge, a soluble Ca-deficient hydroxyapatite (Ca-def HA) coating was deposited on an Mg-Zn-Ca alloy substrate by pulse eletrodeposition. This deposition can be demonstrated by X-ray diffractometry and energy dispersion spectroscopy analyses, and the Ca/P atomic ratio of as-deposited coating is about 1.33 (within the range from 1.33 to 1.65). By regulating the appropriate pulse amplitude and width, the Ca-def HA coating shows better adhesion to Mg-Zn-Ca alloy, whose lap shear strength is increased to 41.8+/-2.7 MPa. Potentiodynamic polarization results in Kokubo's simulated body fluid (SBF) indicate that the corrosion potential of Mg alloy increases from -1645 to -1414 mV, while the corrosion current density decreases from 110 to 25 microA/cm(2), which illustrates that the Ca-def HA coating improves the substrate corrosion resistance significantly. Since orthopaedic implants generally serve under conditions of stress corrosion, the mechanical integrity of the Mg-Zn-Ca alloy was measured using the slow strain rate tensile (SSRT) testing technique in SBF. The SSRT results show that the ultimate tensile strength and time of fracture for the coated Mg-Zn-Ca alloy are higher than those of the uncoated one, which is beneficial in supporting fractured bone for a longer time. Thus Mg-Zn-Ca alloy coated with Ca-def HA is be a promising candidate for biodegradable orthopaedic implants, and is worthwhile to further investigate the in vivo degradation behavior.

Purification of a novel low-molecular-mass laccase with HIV-1 reverse transcriptase inhibitory activity from the mushroom Tricholoma giganteum.

A laccase with a novel N-terminal sequence, a low molecular mass of 43 kDa smaller than those of previously reported laccases, a pH optimum of 4, and a temperature optimum at 70 degrees C was isolated from fresh fruiting bodies of the mushroom Tricholoma giganteum. The activity of the enzyme rose steadily from 20 to 50 degrees C, increased very slowly from 50 to 70 degrees C, and fell slightly when the temperature was further increased to 80 degrees C. The activity of the laccase underwent little changes over the pH range 3.0-5.0. However, the enzyme activity dwindled to nothing after exposure to 100 degrees C for 10 min and when the ambient pH was 7 or above. The procedure used for purifying the enzyme included ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-cellulose, and FPLC-gel filtration on Superdex 75. The laccase was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and CM-cellulose. It inhibited HIV-1 reverse transcriptase with an IC(50) of 2.2 microM.

Purification of a novel ribonuclease from dried fruiting bodies of the edible wild mushroom Thelephora ganbajun.

A ribonuclease, with a molecular mass of 30 kDa and a potent inhibitory activity toward HIV-1 reverse transcriptase (IC50=300 nM), was isolated from dried fruiting bodies of the edible wild mushroom Thelephora ganbajun. The ribonuclease exhibited a unique polyhomoribonucleotide specificity, with the highest activity toward poly(U), about 50% and 25% as much activity toward poly(A) and poly(C), respectively, and minimal activity toward poly(G). Unlike other mushroom RNases, the ribonuclease was adsorbed on DEAE-cellulose and Q-Sepharose, and unadsorbed on CM-cellulose. A temperature of 40 degrees C and a pH of 6-7 were required for maximal activity of the enzyme. The enzyme was characterized by an N-terminal sequence without any homology to known proteins.

Discontinuous Percoll gradients enrich X-bearing human spermatozoa: a study using double-label fluorescence in-situ hybridization.

The aim of this study was to evaluate the efficacy of enriching X-bearing human spermatozoa using 12-step (25-80%) discontinuous Percoll gradients. X- and Y-bearing spermatozoa were simultaneously identified in neat semen (controls) and in 80% Percoll fractions from the same samples using double-label fluorescence in-situ hybridization and chromosome-specific DNA probes. Hybridization and labelling efficiencies of 95-99% were obtained in all samples. The mean ratio of X- to Y-bearing spermatozoa in the controls was 49.0:48.2, whereas there was a significant enrichment (P < 0.0001) of X-bearing spermatozoa in the Percoll fractions (mean X:Y ratio was 55.1:41.1 or 1.35). The ratio varied from 1.1-1.5 in individual Percoll samples. There were no significant differences in the proportions of aneuploid spermatozoa (XX, YY, XY) between the control and Percoll fractions. We conclude that 12-step discontinuous Percoll gradients enrich X-bearing spermatozoa, but the degree of enrichment is insufficient for use in preconceptional sex selection.

[Study on the analytical methods of catechins in tea and green tea polyphenol samples by high performance liquid chromatography].

Hypersil BDS C18 and Zorbax SB C18, suitable to separate simultaneously seven kinds of catechins and caffeine, were screened out from seven brands of reversed-phase columns. Mobile phase was a solution of methanol-water-acetic acid (or trifluoro acetic acid). Seven kinds of catechins in tea samples from six places in China and three green tea polyphenol(GTP) samples from different producers were separated and determined in 30 min by isocratic and gradient elutions. The effects of mobile phase components and temperature of column on retention parameters of catechins and caffeine are reviewed. Chromatographic conditions and pretreatment methods of samples were optimized. Gallocatechin gallate(GCG) and (-)-catechin gallate(CG) were identified by electrospray ionization mass spectrometry(ESI-MS) and prepared by high performance liquid chromatography for quantitative analysis. The other catechins, (-)-epigallocatechin (EGC), (+)-catechin (D-C), (-)-epicatechin(EC), (-)-epigallocatechin gallate(EGCG), (-)-epicatechin gallate(ECG) were identified with standards.