Outcome of Different Endometrial Preparation Protocols Prior to Frozen-Thawed Embryo Transfer on Pregnancy Outcomes in Women with Repeated Implantation Failure

Aim

To compare the pregnancy outcomes of frozen-thawed embryo transfer (FET) cycles among women with repeated implantation failure (RIF) treated with various endometrial preparation protocols.

Methods

A total of 605 women with RIF were retrospectively recruited between January 2017 and December 2020 from Northern Theater General Hospital. Patients were divided into natural cycles, hormone replacement therapy (HRT) cycles, depot gonadotropin-releasing hormone (GnRH) agonist-HRT, and endometrial scratching (ES) plus depot GnRH agonist-HRT. The primary endpoint was clinical pregnancy rate, while secondary endpoints included live birth rate and pain assessment.

Results

Of the 605 recruited patients, 63 were undergoing natural cycles, 281 were treated with HRT cycles, 141 treated with depot GnRH agonist-HRT, and 120 treated with ES combined with depot GnRH agonist-HRT. There were significant differences among protocols on clinical pregnancy rate (P=0.029), while no significant difference was observed among protocols on live birth rates (P=0.108). Multivariate analyses suggested that HRT (odds ratio [OR]: 0.50; 95% confidence interval [CI]: 0.28-0.89; P=0.019) and depot GnRH agonist-HRT (OR: 0.49; 95% CI: 0.27-0.91; P=0.021) cycles were associated with a lower clinical pregnancy rate as compared with natural cycles, while no significant difference between ES combined with depot GnRH agonist-HRT and natural cycles for clinical pregnancy rates (OR: 0.72; 95% CI: 0.38-1.36; P=0.313). Moreover, the HRT (OR: 0.70; 95% CI: 0.39-1.28; P=0.239), depot GnRH agonist-HRT (OR: 0.67; 95% CI: 0.35-1.29; P=0.229), and ES combined with depot GnRH agonist-HRT (OR: 1.11; 95% CI: 0.58-2.14; P=0.754) cycles had no significant effects on live birth rate as compared with natural cycles. A total of 87.50% patients treated with ES combined with depot GnRH agonist-HRT reported pain during the procedure.

Conclusion

ES and depot GnRH agonists could be considered for RIF women with high-quality blastocysts, 14 days after verified transplantation failure.

[Association between cardiometabolic diseases and quality of life and the mediation effect of perceived stress]

Objective: To explore the association between cardiometabolic diseases (CMD) and quality of life, the association between CMD and perceived stress, and the mediation effect of perceived stress on the association between CMD and quality of life, and to provide evidence for the prevention and treatment of CMD and the improvement of quality of life in these patients. Methods: This is a cross-sectional study. Data were collected by the employees' physical examination of a company in Xi'an in 2021. Multiple linear regression models were used to analyze the association between the status of CMD (divided into three categories: no CMD, presence of one kind of CMD, and with≥2 kinds of CMD (≥2 kinds of CMD were defined as cardiometabolic multimorbidity (CMM)), quality of life, and perceived stress. Mediation analysis with a multi-categorical independent variable was conducted to determine the mediation effect of perceived stress on the association between CMD and quality of life. Results: Among all 4 272 participants, 1 457 (34.1%) participants had one kind of CMD and 677 (15.8%) participants had CMM. The average scores for quality of life and perceived stress were (57.5±15.7) and (16.9±7.9), respectively. Compared with participants without CMD, after adjusting for demographic and lifestyle factors, no statistically significant associations were observed between one kind of CMD and perceived stress or quality of life (both P>0.05). Perceived stress did not mediate the association between one kind of CMD and quality of life. However, participants with CMM had lower quality of life and higher perceived stress than participants without CMD. The relative total effect coefficient c (95%CI) and the relative direct effect coefficient c' (95%CI) between CMM and quality of life were -3.71 (-5.04--2.37) and -2.52 (-3.81--1.24) (both P<0.05), respectively. The relative indirect effect coefficient a₂b (95%CI) of perceived stress on the association between CMM and quality of life was -1.18 (-1.62--0.77) (P<0.05). The mediation effect size was 31.8%. Conclusions: CMM is negatively associated with quality of life and positively associated with perceived stress. Perceived stress partially mediates the association between CMM and quality of life. Our results suggest that, in addition to preventing and treating CMM actively, efforts should be taken to relieve the perceived stress of people with CMM to improve their quality of life.

[Immunogenicity and safety of revaccination of 23-valent pneumococcal polysaccharide vaccine in people aged 60 years and above]

Objective: To evaluate the immunogenicity and safety of revaccination of 23-valent pneumococcal polysaccharide vaccine (PPV23) in elderly people aged ≥60 years. Methods: The elderly aged ≥60 years with 1 dose of PPV23 vaccination were selected as revaccination group and those without history of pneumococcal vaccine immunization were selected as the first vaccination group. One dose of PPV23 was administered to both groups, and the first blood samples were collected before vaccination while the second blood samples were collected on day 28-40 after vaccination. ELISA was used to detect the concentrations of anti-specific serotype Streptococcus pneumoniae podocyte polysaccharide immunoglobulin G, and the safety of the vaccination was evaluated after 30 days. Results: The geometric mean concentration (GMC) of antibody to 23 serotypes before the vaccination (0.73-13.73 μg/ml) was higher in revaccination group than in the first vaccination group (0.39-7.53 μg/ml), the GMC after the vaccination (1.42-31.65 μg/ml) was higher than that before the vaccination (0.73-13.73 μg/ml) in the revaccination group, and the GMC after the vaccination (1.62-43.76 μg/ml) was higher than that before the vaccination (0.39-7.53 μg/ml) in the first vaccination group; the geometric mean growth multiple in revaccination group (2.16-3.60) was lower than that in the first vaccination group (3.86-16.13); The mean 2-fold antibody growth rate was lower in revaccination group (53.68%, 95%CI: 52.30%-55.06%) than in the first vaccination group (93.16%, 95%CI: 92.18%- 94.15%), all differences were significant (P<0.001). After the vaccination, 13 serotypes of GMC were higher in the first vaccination group than in revaccination group (P<0.001), the differences were not significant for 10 serotypes of GMC (P>0.05). The incidence of local adverse reaction was 19.20% and 13.27% in revaccination group and the first vaccination group, respectively (P=0.174). Conclusions: The antibody level in ≥60 years people who received one dose of PPV23 after a 5-year interval was still higher than that in unvaccinated people. The antibody level decreased after 5 years of the first vaccination, and the antibody level could be rapidly increased by one more dose vaccination, but the overall immune response was lower than that of the first vaccination; revaccination with PPV23 has a good safety.

Unravelling intrinsic descriptors based on a two-stage activity regulation of bimetallic 2D c-MOFs for CO2RR

The bimetallic 2D conductive MOFs of M₁Pc-M₂-O, possessing dual metal sites to realize flexible molecular-level structural modification, are brilliant catalysts for electrochemical CO₂ reduction. However, the bimetallic centers bring about the complex regulatory mechanism of catalytic activity and obscure principles for catalyst design. Herein, systematical theoretical investigation unravels intrinsic descriptors to design favorable M₁Pc-M₂-O catalysts based on the discovered coarse-fine two-stage activity regulation mechanism. The reaction site controls the M-COOH distance of the key intermediate and therefore affects the reaction kinetics for the first stage of coarse regulation. The other metal site influents the d-band center of the reaction site and thus constitutes the second stage of fine regulation. The coarse and fine regulation are related to the valence electrons (V), electronegativity (E), and bond length (L_M-N/O) between the metal and coordination atoms. The intrinsic descriptor ϕ = (4 × V_M1 × (E_M1 + E_N/O)/E_N/O + V_M2 × (E_M2 + E_N/O)/E_N/O) × L_M1-N/O (with a coefficient ratio of 4 : 1) was eventually established and correlated well with the reported experiments. On this basis, the favorable catalysts CoPc-Zn-O and CoPc-Co-O were located. The research results could contribute to the diversity of bimetallic 2D c-MOFs in CO₂RR.

Application of digital positioning guide plates for the surgical extraction of multiple impacted supernumerary teeth: A case report and review of literature

BACKGROUND

An extra tooth in the normal tooth sequence in any region of the dental arch is regarded as a supernumerary tooth (SNT). Due to the large variation in location and morphology, the extraction of impacted SNTs is an extensive and complex procedure with high risks of several complications. This report presents a rare case of seven impacted SNTs in the bilateral upper and lower arch that were successfully extracted with the use of digital positioning guide plates.

CASE SUMMARY

In January 2022, a 21-year-old male was referred to our department with a chief complaint of pain in relation to tooth #36. Clinical examination showed a deep carious lesion with pulpal involvement in tooth #36 and lingual swelling of the bilateral mandibular posterior area. Radiographic examination revealed seven deeply impacted SNTs in the bilateral posterior area and bilateral impacted mandibular third molars. Based on these findings, the patient was diagnosed with bilateral, multiple impacted SNTs and tooth #36 chronic pulpitis. A root canal treatment and an all-ceramic crown restoration for tooth #36 were performed. An individualized digital positioning guide plate was designed by computer-aided design/computer-aided manufacturing technology and cone-beam computed tomography for extraction of the impacted SNTs. During the operation, the digital positioning guide plate allowed rapid positioning and exposure of the SNTs while avoiding adjacent important anatomical structures. At 3-month follow-up, regeneration of bone and soft tissues was visible.

CONCLUSION

The application of digital positioning guide plates is useful for the individualized and minimalized extraction of impacted supernumerary teeth.

Upregulation of mitochondrial dynamics is responsible for osteogenic differentiation of mesenchymal stem cells cultured on self-mineralized collagen membranes

Collagen membranes crosslinked with high molecular weight polyacrylic acid (HPAA) are capable of self-mineralization via in situ intrafibrillar mineralization. These HPAA-crosslinked collagen membranes (HCM) have been shown to promote osteogenic differentiation of mesenchymal stem cells (MSCs) and enhance bone regeneration in vivo. Nevertheless, the biological triggers involved in those processes and the associated mechanisms are not known. Here, we identified the contribution of mitochondrial dynamics in HCM-mediated osteogenic differentiation of MSCs. Mitochondriogenesis markers were significantly upregulated when MSCs were cultured on HCM, committing the MSCs to osteogenic differentiation. The mitochondria fused to form an interconnected mitochondrial network in response to the high energy requirements. Mitochondrial fission in MSCs was also triggered by HCM; fission slightly declined at 14 days to restore the equilibrium in mitochondrial dynamics. Mitophagy, another event that regulates mitochondrial dynamics, occurred actively to remove dysfunctioned mitochondria and isolate damaged mitochondria from the rest of network. The mitophagy level of MSCs was significantly elevated in the presence of HCM. Taken together, the present findings indicate that upregulation of mitochondrial dynamics via mitochondriogenesis, fusion, fission and mitophagy is responsible for HCM-mediated osteogenic differentiation of MSCs. STATEMENT OF SIGNIFICANCE: High molecular weight polyacrylic acid (HPAA)-crosslinked collagen membrane (HCM) was found to promote in-situ bone regeneration because of it can stimulate osteogenic differentiation of mesenchymal stem cells (MSCs). Nevertheless, the biological triggers involved in those processes and associated mechanisms are not known. This study identifies that activation of mitochondrial dynamics is centrally involved in HCM-mediated osteogenic differentiation of MSCs. The HCM accelerates mitochondriogenesis and regulates homeostasis of the mitochondrial network in response to the increased energy demand for osteogenic differentiation. Concomitantly, mitophagy actively occurs to remove dysfunctioned mitochondria from the rest of the mitochondrial network. Identification of the involvement of mitophagy in HCM-mediated osteogenic differentiation of MSCs opens new vistas in the application of biomimetic mineralization in bone tissue regeneration.

[Immunogenicity and safety of a boost dose of measles, mumps, and rubella combined vaccine for 4-6 years old children]

Objective: To investigate the immunogenicity and safety of a boost dose of measles, mumps, and rubella combined vaccine (MMR) for children 4 to 6 years old. Methods: Children, aged 4 to 6 years old, had vaccinated with 1 dose of measles and rubella combined vaccine(MR) at the age of 8 months and 1 dose of MMR vaccine at 18-months, were recruited in Shanxi, Inner Mongolia, and Beijing, respectively. All children were assigned into 4, 5 and 6-year-old group. The children who met inclusion and exclusion criteria were vaccinated with 1 dose MMR vaccine, and were collected blood samples before vaccination and 35 to 42 d after the vaccination. During the study period, adverse events were collected at 30 min, 1 d, 2 d, 3 d, 4-12 d, and 13 to 42 days after vaccination. Serum was tested for IgG antibodies against measles, mumps and rubella. Geometric mean concentrations (GMC) of measles, mumps, and rubella antibodies were compared among groups by analysis of variance or non-parametric test. Seropositive rates and adverse event rates were compared among groups by Chi-square test or Fisher exact test. Results: A total of 500 children were included in immunogenicity analysis and 535 children were included in safety analysis. The overall adverse event rate was 20.37%, the most of severity for adverse events was mild. The rates of local and systemic adverse events were 0.37% and 20.00%, respectively. Symptoms of local adverse events were redness. The main systemic adverse events were fever, followed by cough, rash and runny nose. Received a dose of MMR vaccine for booster immunization, the seropositive rates of measles antibody, mumps antibody and rubella antibody were above 99% for all 3 age groups, and there was no significant difference between groups. There were significant differences in mumps antibody GMC among groups (P=0.042), but no significant differences in measles and rubella antibodies GMC. Conclusion: The immunogenicity and safety of a boosted MMR vaccintion in children aged 4, 5 and 6 years were all similar good.

A novel dentin bonding scheme based on extrafibrillar demineralization combined with covalent adhesion using a dry-bonding technique

Dentin bonding is a dynamic process that involves the penetration of adhesive resin monomers into the extrafibrillar and intrafibrillar demineralized collagen matrix using a wet-bonding technique. However, adhesive resin monomers lack the capacity to infiltrate the intrafibrillar space, and the excess water that is introduced by the wet-bonding technique remains at the bonding interface. This imperfectly bonded interface is inclined to hydrolytic degradation, severely jeopardizing the longevity of bonded clinical restorations. The present study introduces a dentin bonding scheme based on a dry-bonding technique, combined with the use of extrafibrillar demineralization and a collagen-reactive monomer (CRM)-based adhesive (CBA). Selective extrafibrillar demineralization was achieved using 1-wt% high-molecular weight (MW) carboxymethyl chitosan (CMCS) within a clinically acceptable timeframe to create a less aggressive bonding substance for dentin bonding due to its selectively extrafibrillar demineralization capacity. CMCS demineralization decreased the activation of in situ collagenase, improved the shrinking resistance of demineralized collagen, and thus provided stronger and more durable bonding than traditional phosphoric acid etching. The new dentin bonding scheme that contained CMCS and CBA and used a dry-bonding technique achieved an encouraging dentin bonding strength and durability with low technical sensitivity. This bonding scheme can be used to improve the stability of the resin-dentin interface and foster the longevity of bonded clinical restorations.

The antibacterial effect and physical performance of pit and fissure sealants based on an antibacterial core-shell nanocomposite

The application of pit and fissure sealants is a well-established method to prevent and treat early childhood caries. Resin-based sealants with antibacterial properties provide additional benefits for caries prevention in a cariogenic oral environment. The objective of this study was to evaluate the effect of an antibacterial core-shell AgBr/cationic polymer nanocomposite (AgBr/BHPVP) on the properties of a resin-based pit and fissure sealant. A commercialized pit and fissure sealant without fluoride, Concise (3M, ESPE, USA), was used as the parent material and negative control. Experimental antibacterial sealants were formulated by the addition of AgBr/BHPVP nanoparticles at mass fractions of 0.5, 1.0, and 1.5 wt% to the parent material. A fluoride-releasing sealant, Clinpro (3M, ESPE), was used as the positive control. Bacterial colony-forming unit (CFU) counts, metabolic activity tests, field emission-scanning electron microscopy (FE-SEM), and confocal laser scanning microscopy (CLSM) observations were used to evaluate the antibacterial properties of AgBr/BHPVP-modified sealants against Streptococcus mutans before and after five months of aging. The Vickers microhardness, degree of conversion, and microleakage level of the sealants were also investigated. According to the results of CFU counts and metabolic tests, sealants containing AgBr/BHPVP showed better contact-killing bactericidal activity against S. mutans than the two commercial sealants, irrespective of aging conditions (both P < 0.05). The AgBr/BHPVP-modified sealants also showed a significant inhibitory effect on the planktonic S. mutans around the cured sealant surfaces. In addition, the Vickers microhardness, degree of conversion, and microleakage level of the parent material were not damaged by modification with AgBr/BHPVP (P > 0.05). AgBr/BHPVP-modified pit and fissure sealant with a dual bactericidal mechanism is a promising option for the prevention of pit and fissure caries.

[Anatomical relationship between fascia propria of the rectum and visceral pelvic fascia in the view of continuity of fasciae]

Objective: To perform an anatomical observation on the extension of the mesocolon to the mesorectum and the continuity of the fasciae lining the abdomen and pelvis, in order to clarify the appropriate surgical plane of total mesorectal excision. Methods: This is an descriptive study. The operation videos of 61 cases (28 males, 33 females, median age of 61) were collected. All the patients underwent laparoscopic colorectal surgery from January 2018 to December 2018 in Yangpu Hospital, including low anterior resection for rectal cancer in 25 cases, left hemicolectomy for descending colon cancer in 15 cases, and subtotal resection of the colon for intractable constipation in 21 cases. Among these 21 constipation patients, 8 received additional modified Duhamel surgeries. Gross anatomy was performed on 24 adult cadavers provided by Department of Anatomy, Shanghai Jiaotong University School of Medicine, including 23 formalin-fixed and 1 fresh cadaver (12 males, 12 females). Sixty-one patients and 24 cadavers had no previous abdominal or pelvic surgical history. The anatomy and extension of fasciae related to descending colon, sigmoid colon and rectum, especially the morphology of Toldt fascia, and the continuities of mesocolon and mesorectum were observed carefully. The distribution characteristics of the fasciae and anatomical landmarks during laparoscopic surgery were recorded and described. Results: The anatomical study on 24 cadavers showed that visceral fascia was the densest connective tissue in the pelvic, posterolateral to the rectum, and stretched as a hammock to lift all pelvic organs. Among 61 patients undergoing laparoscopic surgery, 36 (59.0%) needed to free the left colon during operation, and Toldt fascia in the descending colon segment presented as potential, avascular and extensible loose connective tissue plane between the mesocolon and posterior Gerota fascia; 33 (54.1%) needed to free the rectum during operation, and Toldt fascia extended downward to pelvis as loose connective tissue between the fascia propria of the rectum and visceral fascia; the fascia propria of the rectum exposed completely in 32 (32/33, 97.0%) cases, which ran downward and fused with visceral fascia at the level of the fourth sacral vertebra. The anatomy of 24 cadavers also showed that fascia propria of the rectum fused with visceral fascia at the level of Waldeyer fascia. The fusion line of these two fasciae was supposed to be the extension of Waldeyer fascia. There were two avascular planes behind the rectum: one between the fascia propria of the rectum and visceral fascia, and the other between the visceral fascia and parietal fascia. In 8 constipation cases undergoing laparoscopic subtotal colon resection plus modified Duhamel operation, both mesocolon and mesorectum needed to be mobilized. It was obvious that the mesocolon of descending colon extended and became the mesocolon of sigmoid colon, and ran further into the pelvic and became the mesorectum. The colon fascia of descending colon served as the natural boundary of mesocolon extended downward as the fascia of sigmoid colon and the fascia propria of the rectum, respectively. Toldt fascia locating between mesocolon of descending colon and Gerota fascia extended to pelvis as the 'presacral space' between the fascia propria of the rectum and visceral fascia. Gerota fascia in descending colon segment extended as urogenital fascia in sigmoid colon segment and visceral fascia in the pelvis, respectively. In the cadaver anatomy study, the visceral fascia served as a corridor carrying the hypogastric nerve, and ureter was observed in 23 (23/24, 95.8%) cases. The visceral fascia passed from posterior to anterior lateral of rectum, fusing with Denonvilliers fascia in a fan shape. The pelvic plexus located exactly external to the junction of visceral fascia and Denonvilliers fascia. Pelvic splanchnic nerves went through the parietal fascia toward to the inferolateral of the pelvic plexus. Conclusion: Fascia propria of the rectum and the visceral pelvic fascia are two independent layers of fascia, and the TME surgical plane is between the fascia propria of the rectum and visceral pelvic fascia instead of between the visceral and the parietal pelvic fascia.

[The reliability of using impenem, meropenem, cefoperazone-sulbactam and piperacillin-tazobactam to treat nosocomial Gram-negative bacterial infections with Monte Carlo simulation]

Objective: To evaluate the reliability of using imipenem, meropenem, cefoperazone-sulbactam, piperacillin-tazobactam in the treatment of hospital-acquired Gram-negative bacterial infections with Monte Carlo simulation(MCS). Methods: The MIC of the four agents collected from hospital-acquired infections were detected in accordance with broth dilution method of Clinical and Laboratory Standard Institute (CLSI). MCS were conducted with MICs and the pharmacokinetics parameters of the four agents based on conventional dose regimens.The cumulative fraction of response (CFR) of time over MIC target attainment in different dosing regimen were generated. Results: A total of 2 541 strains, including 2 093 strains of Enterobacteriaceae and 448 strains of glucose non-fermentative bacilli were collected.The MIC(90) of imipenem and meropenem against Enterobacteriaceae were less than 1 mg/L in general, whereas MIC(90) of two agents with β-lactamase inhibitors was around 64 mg/L.As to glucose non-fermenting bacteria, MICs of all the four agents were very high, especially to Acinetobacter baumannii, which indicated MIC(50) more than 32 mg/L.MCS revealed that carbapenems had significantly higher CFR than those with β-lactamase inhibitors.Imipenem and meropenem (1 g, q8 h) obtained CFRs of 74.69% and 81.42%, respectively.The CFR of cefoperazone-sulbactam (2 g, q8 h) and piperacillin-tazobactam (4 g, q6 h) (both excluding β-lactamase inhibitors) were just 49.59% and 27.66% respectively, which increased after excluding A. baumannii in piperacillin-tazobactam. Conclusions: The conventional dose regimens of imipenem and meropenem are reliable for the empiric therapy of Gram-negative hospital-acquired bacterial infections.Piperacillin-tazobactam is suggested to use with higher doses or prolonged infusion time to satisfy the time of drug concentration exceeded the MIC(T>MIC)requirement.More clinical studies of cefoperazone-sulbactam should be conducted to optimize its regimen and guarantee its efficacy.

[Latest Research Advance of Myeloproliferative Diseases Related Genes-Review]

JAK2, MPL and CALR gene mutations play an important role in the onset of myeloproliferative disease(MPD). The latest researches show that the difference of ATP binding ability between the wild type JAK2 protein and mutated JAK2 protein can help us understand the pathogenesis of the MPD further, and the clinical manifestation is related to the mutation burden of the JAK2. In some ET and PMF patients, research find the expression of MPL mutation, which can affects the progress of the disease by collaborating with the JAK2 mutation. CALR mutation is a gene related with the MPD that has been found recently. The pathogenesis of the CALR is similar to that of the JAK2, while there are some features in clinical manifestation comparing with the other mutations.

The antifungal effects and mechanical properties of silver bromide/cationic polymer nano-composite-modified Poly-methyl methacrylate-based dental resin

Poly-methyl methacrylate (PMMA)-based dental resins with strong and long-lasting antifungal properties are critical for the prevention of denture stomatitis. This study evaluated the antifungal effects on Candida albicans ATCC90028, the cytotoxicity toward human dental pulp cells (HDPCs), and the mechanical properties of a silver bromide/cationic polymer nano-composite (AgBr/NPVP)-modified PMMA-based dental resin. AgBr/NPVP was added to the PMMA resin at 0.1, 0.2, and 0.3 wt%, and PMMA resin without AgBr/NPVP served as the control. Fungal growth was inhibited on the AgBr/NPVP-modified PMMA resin compared to the control (P < 0.05), and the antifungal activity increased as the incorporation of the AgBr/NPVP antimicrobial composite increased. Confocal laser scanning microscopy (CLSM) showed that the number of fungal cells attached to the modified PMMA resin was considerably lower than in the control. The relative growth rate of HDPCs of modified groups were higher than 75%. The flexural strength (FS) and flexural modulus (FM) were not significantly different (P > 0.05) between the experimental and control groups. These data indicate that the incorporation of AgBr/NPVP conferred strong and long-lasting antifungal effects against Candida albicans to the PMMA resin, and it has low toxicity toward HDPCs, and its mechanical properties were not significantly affected.

[Comparison of the effects of total hip arthroplasty via direct anterior approach and posterolateral piriformis-sparing approach]

OBJECTIVE

To compare the clinical effects of direct anterior approach (DAA) and posterolateral piriformis-sparing approach (Mis-PLA) for minimally invasive surgery of total hip arthroplasty.

METHODS

The patients who had total hip arthroplasty from March 2015 to February 2016 were randomly divided into 2 groups: DAA group and Mis-PLA group. In the study, 43 patients (45 hips) were performed with total hip replacement via the direct anterior approach (DAA group). As comparison, 39 patients (42 hips) were performed with total hip replacement via the posterolateral piriformis-sparing approach (Mis-PLA group) at the same period. DAA group: 27 male patients (27 hips), and 16 female patients (18 hips), with an average age of (57.4±7.3) years, preoperative Harris score (41.4±8.7), body mass index (BMI) (24.3±2.2) kg/m²; Mis-PLA group: 25 male patients (26 hips), 14 female patients (16 hips), with an average age of (59.2±7.3) years, preoperative Harris score (39.6±8.4), BMI (24.7±2.5) kg/m². The length of incision, operation time, blood loss, postoperative Harris score were observed and specially the hip functional recovery was fully assessed.

RESULTS

(1) All the incisions healed by first intention. No complications were found in both groups. The length of incision:DAA group: (9.2±0.7) cm and Mis-PLA group: (9.5±0.6) cm. No statistical significant differences were found (P=0.053). The operation time:DAA group (74.3±10.1) min and Mis-PLA group (37.5±4.3) min, which showed statistically significant differences (P<0.01). Blood loss: DAA group (229.6±79.2) mL and Mis-PLA group (215.7±56.0) mL. No statistical significant differences were found (P=0.366). (2) The patients in both groups were followed up for 6-12 months. The Harris hip scores for 6 weeks' follow-up: (85.5±4.1) in DAA group and (79.0±4.4) in Mis-PLA group, which indicated statistically significant differences (P<0.01). The Harris scores for the 6-month follow-up: (94.3±2.7) in DAA group and (95.2±1.9) in Mis-PLA group. No statistically significant differences were found (P=0.125). The basic daily hip function analysis for the 6-week follow-up: walking speed: no statistically significant differences were found between the two groups (P=0.298); Climbing stairs: Mis-PLA group' outcome was better than DAA group's with statistical differences (P=0.047); Circling, sitting and wearing shoes and socks: outcomes in DAA group exceeded Mis-PLA group's with statistically significant differences (P<0.01, P=0.016, P<0.01).

CONCLUSION

Total hip arthroplasty through either DAA or Mis-PLA approaches could result in very satisfactory clinical effect. Comparing with DAA, Mis-PLA requires less operation time, shorter learning curve,which indicates that it is a relatively safer approach. The advantages of total hip arthroplasty through direct anterior approach lie in less positional limitation in the early stage of postoperative period, as well as a faster recovery of hip function.

[Utilization of Quality-of-life assessment Questionnaires for Intermittent Exotropia in China]

OBJECTIVE

To evaluate the reliability and validity of Chinese version of Quality-of-life assessment Questionnaires for Intermittent Exotropia (CIXTQ).

METHODS

Cross-sectional study. The original English version of the IXTQ was translated into Chinese. The final Chinese version of the IXTQ (CIXTQ) consists of 3 parts: the 12-item child CIXTQ (for children ≥5 and<8 years old and ≥8 and<18 years old, respectively, to assess their health quality of life (HRQoL)), the 12-item proxy CIXTQ (for parents to assess children's HRQoL), and the 17-item parent CIXTQ (containing functional, psychosocial, and surgery subscales; for parents to assess their HRQoL). 175 IXT children and 151 control children along with one of their parents were recruited to answer the CIXTQ. Cronbach's α coefficient and split-half reliability were used to test the internal consistency reliability of the CIXTQ. Kappa coefficient was used to assess the test-retest reliability. Scale-level content validity index/average (S-CVI/Ave) was used to evaluate the content validity of the CIXTQ. Principal component analysis (PCA) was used to verify the construct validity of the parent CIXTQ. Comparison of different CIXTQ scores in IXT patients with controls was conducted by independent-samples t test to evaluate the discriminate validity of the CIXTQ.

RESULTS

For all scales and subscales of the CIXTQ in different age groups, the Cronbach's α ranged from 0.804 to 0.963; the split-half reliability ranged from 0.658 to 0.963 and was higher than 0.7 except for the proxy CIXTQ for children aged ≥5 and<8 years old; the test-retest reliability ranged from 0.569 to 0.944. The S-CVI/Ave of the child, proxy and parent CIXTQ was 0.988, 0.988 and 0.966, respectively. Principal factors identified by PCA for the parent CIXTQ could be regrouped into the originally described 3 subscales which was functional, social psychology and surgery in different age groups. The mean scores of all the scales and subscales among IXT children and their parents (8.0±12.5-81.6 ±15.1) were significantly lower than these among control children and their parents (83.1±11.3-99.6±1.2) (t values range from -50.36 to -6.93, P<0.001).

CONCLUSIONS

The CIXTQ are useful tools to evaluate the influence of IXT on HRQoL among Chinese children and their parents. (Chin J Ophthalmol, 2016, 52: 596-603).

[Three dimensional reconstruction measurement study of palatal contour changes in different bone ages after rapid maxillary expansion]

Objective: To compare dental and skeletal changes after rapid maxillary expansion in patients with different bone ages. Methods: Thirty-seven patients in different growth period were divided into three groups according to cervical vertebral maturation (CVM). There were 13 patients in the growth acceleration group, 13 patients in growth peak group, and 11 patients in growth deceleration group. Cone-beam computed tomography (CBCT) images were segmented and reconstructed using Mimics image processing software to assess the change of palatal morphology before and after treatment. Statistical analysis was carried out using SPSS 17.0 software. Results: After the expansion the posterior teeth and alveolar bone were tilted and the mid-palatal suture was opened in all three groups. The first molar angle in the three groups decreased by 2.66°±1.04°, 3.53°±0.81° and 12.32°±1.64°, respectively and no significant difference was found between the acceleration group and the peak group (P >0.05), but the changes in the acceleration group and the peak groups were significantly less than that in the deceleration group (P<0.05). The palatal angle in the three groups increased by 6.01° ± 2.06°, 4.79° ± 1.31° and 6.73° ± 1.71°, respectively and no significant difference was found between the acceleration group and the deceleration group (P>0.05), but the changes in the acceleration group and the deceleration group were significantly greater than that in the peak group (P<0.05). The palatal cemento-enamel junction (CEJ) width, the middle palate width and the mid-palatal suture width in the three groups increased by (7.37 ± 1.31), (6.68 ± 0.72) and (5.13 ± 1.42) mm; (5.72±1.68), (4.82±1.66) and (3.42±1.15) mm; (3.14±0.45), (2.98±0.51) and (0.96±0.83) mm, respectively and no significant difference was found between the acceleration group and the peak group (P >0.05), but the changes in the acceleration group and the peak group were significantly greater than that in the deceleration group (P <0.05). Conclusions: The mid-palatal suture could be opened in patients in different CVM period. More skeletal and less dental effects were found in patients in the growth acceleration and peek group than in those in the growth deceleration group and the inclination of the alveolar bone could be avoided to a greater degree in patients in the growth peek group.

[Modification of the composite resin with the hyperbranched polyester and evaluation of the mechanical properties of the modified composite resin]

OBJECTIVE

To study the effect of hyperbranched polyester(HBP)on mechanical properties of the conventional resin matrix.

METHODS

Two hyperbranched monomers(HBP2-X and HBP2-Y)were synthesized and incorporated at 40%(by mass)into a 2∶1(by mass)bisphenol-A diglycidyl methacrylate(Bis-GMA): triethylene glycol dimethacrylate(TEGDMA)resin. Bis-GMA/TEGDMA without the incorporation of hyperbranched polyester was used as control(n=8 per group). The mechanical properties of the modified neat resin, including polymerization volumetric shrinkage, Vickers hardness, water absorption and dissolution rate, as well as the flexural strength, compressive strength and diametral tensile strength of the composite resin with different content of filler(0%, 30%, 50%, 70%)were measured. Mechanical properties of the composite resin were measured by universal testing machine. The results were analyzed by the ANOVA and LSD-t-test.

RESULTS

The resin with HBP greatly decreased the polymerization shrinkage of the composite resin, and the value of group X was(6.32±0.49)%, and that of group Y was(6.31±0.68)%, whereas that of the control group was(8.14 ± 0.53)%. The value of volumetric shrinkage of the modified groups were significantly lower than that of the control group(P<0.05). By adding HBP, the hardness value of group X([198 ± 5]MPa)and group Y([177 ± 4]MPa)were significantly lower than that of the control group([214±6]MPa)(P<0.05). The HBP significantly influenced the water sorption and solubility of the neat resin(P<0.05). For the composite materials, with 70% inorganic filler, there were no significant difference in the value of flexural strength among the groups(P>0.05). There was no significant difference in the value of compressive strength, between group X([244 ± 13]MPa)and the standard group([234 ± 17]MPa)(P>0.05). However, they were significantly higher than that in group Y([204 ± 24]MPa)(P<0.05). For the value of diametral tensile strength, there was no significant difference between group Y([36.4 ± 2.1]MPa)and the control group([34.4 ± 2.9]MPa)(P>0.05), but both were significantly lower than that in group X([41.1 ± 3.0]MPa)(P<0.05).

CONCLUSIONS

Although there were certain effect on the mechanical properties of the resin that was modified with the HBP, we should make further analysis and study based on the property of low volumetric shrinkage, to strive for the development of low volumetric shrinkage of HBP, without affecting its mechanical properties.

Development of indirect ELISAs for differential serodiagnosis of classical and highly pathogenic porcine reproductive and respiratory syndrome virus

The objective of this study was to develop two indirect enzyme-linked immunosorbent assays (iELISAs) for detection of serum antibodies against classical vaccine strain of porcine reproductive and respiratory syndrome virus (PRRSV) and highly pathogenic PRRSV (HP-PRRSV). To detect the common antibodies against classical and HP-PRRSV, the coating antigen used in the iELISA (designated iELISA-180) was the antigen of Nsp2-180, the 180aa at amino terminal of Nsp2. To detect the different antibodies against classical and HP-PRRSV, the coating antigen in the second iELISA (designated iELISA-D29) was Nsp2-D29, the deleted 29aa in Nsp2 of HP-PRRSV. The antigen concentration and serum dilutions were optimized using a draughtboard titration. The cut-off values of 0.361 at OD(450nm) for the iELISA-180 and 0.27 at OD(450nm) for the iELISA-D29 were determined by testing a panel of 120 classical PRRSV positive and 198 PRRSV negative pig serum samples, which generated the specificity of 97.1% and 96.7%, the sensitivity of 96.9% and 96.3% for iELISA-180 and iELISA-D29, respectively. The agreements between the Western blot and iELISA-180 and iELISA-D29 were 98%, 96.7%, respectively. The developed iELISAs can be used to differentiate serologically HP-PRRSV from the vaccinated or classical PRRSV in clinical serum samples.

[Determination of heavy metal by AAS in railway rock-cut slope soil]

Heavy metal contents in railway rock-cut slope soil have directly influenced ecosystem on rock-cut slope and eco-envi- ronment safety of farmland nearby. In the study heavy metal Pb, Cd, Zn, Cu and Mn was determined by AAS in railway rock-cut slope and control soil samples on Cheng-Da Railway crossing purple soil in Sichuan province. The results showed that Pb and Mn were significantly higher in rock-cut soil than in control soil, that is 29.7%-35.4%, while Cd, Zn and Cu were similar in both soils.

[Influence of nano-silica content on flexural properties of the aluminum borate whisker and silica filler composite resins]

OBJECTIVE

To discuss the influence of nano-silica content which was hydrolyzed by tetraethyl orthosioate (TEOS) on the aluminum borate whisker (AlBw) and silica filler composite resins on flexural properties.

METHODS

The nanometer-size silicon dioxide (SiO2) particles were prepared by sol-gel method based on tetraethyl orthosioate. Different proportion of AlBw and SiO2 were fused and attached onto the surface of AlBw through high temperature, then polymerized with resin matrix after surface siliconization and their flexural strength and flexural modulus were determined. The effects of heat treatment to the surface morphology of AlBw and the shapes of the mixture at various proportions were characterized by TEM.

RESULTS

The flexural properties of dental composite resins with AlBw-SiO2 compound as inorganic fillers were significantly improved. The flexural property of a new type of dental composite resins was(130.29 +/- 8.38) MPa, when the mass ratio of AlBw and nano-SiO2 particle was 3:1.

CONCLUSION

Nano-silica content which was hydrolyzed by tetraethyl orthosioate improved flexural properties of the aluminum borate whisker and silica filler composite resins.

Bacterial resistance surveillance in China: a report from Mohnarin 2004-2005

The aim of this study was to establish a nationwide antimicrobial resistant surveillance network and obtain information on bacterial resistance in China. A total of 4075 clinical bacterial isolates were collected from 17 hospitals in 15 cities throughout China. Antibacterial minimal inhibitory concentrations (MICs) were determined by the standard agar dilution method recommended by Clinical and Laboratory Standards Institute. The results of the MICs revealed the following bacterial resistance characteristics. Oxacillin resistance was shown by 62.9% of Staphylococcus aureus and 82.89% of Staphylococcus epidermidis strains. Penicillin non-sensitivity was show by 40.7% of the Streptococcus pneumoniae strains, which included 10.5% penicillin-resistant strains and 30.2% penicillin-intermediate strains. Five strains of Enterococci were vancomycin-intermediate, but all Enterococci strains were sensitive to teicoplanin. All Staphylococci were susceptible to glycopeptides. A high resistance to macrolides was a predominant characteristic of the Gram-positive cocci. Enterobacteriaceae strains were clearly resistant to the third generation cephalosporins, with the exception of ceftazidime, and the resistance rates ranged from 20 to 70%. About 65% of the Escherichia coli strains were resistant to fluoroquinolones. Carbapenems remained highly active against all the target bacteria. Latamoxef, piperacillin/tazobactam, cefoperazone/sulbactam and cefepime were all active against Enterobacteriaceae, which showed resistant rates of less than 10%. Imipenem resistance was found in 10.6% of Pseudomonas aeruginosa and 10.4% of Acinetobacter baumannii strains, most of which were multidrug resistant isolates. Combinations of beta-lactam/beta-lactamase inhibitor and fluoroquinolones also had potent antibacterial activity against non-fermenters. Amikacin was active against Enterobacteriaceae and P. aeruginosa. In conclusion, methicillin-resistant Staphylococci, penicillin-insensitive S. pneumoniae, macrolides-resistant Gram-positive cocci, cephalosporin-resistant Enterobacteriaceae, multidrug-resistant nonfermenters and fluoroquinolone-resistant E. coli were revealed to be the most serious problems in terms of bacteria resistance in China. No glycopeptides-resistant Staphylococcus strains were isolated, and the appearance of glycopeptides-resistant Enterococci was seldom.

Methyl 3-(4-{6-methyl-4-[3-(trifluoromethyl)phenyl]pyridazin-3-yloxy}phenyl)propanoate

In the title compound, C₂₂H₁₉F₃N₂O₃, the benzene rings of the trifluoro­methyl­phenyl and benzoyl­phenyl groups form dihedral angles of 41.89 (10) and 67.44 (10)°, respectively, with the pyridazine ring. The methyl­propanoate group is nearly coplanar with the attached benzene ring [dihedral angle = 3.9 (2)°]. The trifluoro­methyl group is disordered over two positions; the site-occupancy factors are ca 0.64 and 0.36. In the crystal structure, inversion-related mol­ecules are linked through C—H⋯O hydrogen bonds and C—H⋯π inter­actions.

[Preparation and antibacterial activity of quaternary ammonium salt monomers]

OBJECTIVE

To prepare three quaternary ammonium salt (QAS) monomers, and to compare their antibacterial activities against four oral bacterial strains.

METHODS

Three antibacterial monomers [methacryloxyethyl benzyl dimethyl ammonium chloride (DMAE-BC), methacryloxyethyl m-chloro benzyl dimethyl ammonium chloride (DMAE-m-CBC), methacryloxyethyl cetyl dimethyl ammonium chloride (DMAE-CB)] were synthesized according to the general structure of target monomers. Their antibacterial effects were investigated using the broth dilution test on Gram-positive and Gram-negative bacterial strains (Streptococcus mutans, Streptococcus sanguis, Porphyromonas gingivalis, Prevotella melaninogenica ).

RESULTS

Three different monomers were successfully obtained. All the tested bacterial strains were susceptible to the three monomers, among which DMAE-CB exhibited the lowest minimal inhibitory concentrations (MIC) ranging from 1.2 to 4.8 mg/L.

CONCLUSIONS

All these three QAS monomers have different antibacterial activities against four oral bacteria strains. The data indicate that DMAE-CB may be a candidate antibacterial agent for oral infectious diseases.

The first molecular analysis of clinical isolates of VanA-type vancomycin-resistant Enterococcus faecium strains in Mainland China

AIMS

The aim of this study was to examine two VanA-type vancomycin-resistant Enterococcus faecium (VRE) strains that had been isolated from patients resident in mainland China. This is the first molecular analysis of clinical VRE strains being isolated in mainland China.

METHODS AND RESULTS

Two VanA-type VRE isolates were isolated from in-patients at hospitals located in the Chinese cities Beijing and Dalian and were designated C264 and I125. The plasmids pC264V (40 kbp) and pI125V (370 kbp) that were isolated from C264 and I125, respectively, carried a Tn1546-like element encoding VanA resistance. The vancomycin-resistant plasmids pC264V and pI125V were transferred by filter mating at frequencies of 10(-7) and 10(-4) respectively. Sequence analysis of pC264V revealed that two IS1216V sequences and an IS1542 sequence were present within the Tn1546-like element. pI125V had two IS1216V insertions in the Tn1546-like element.

CONCLUSIONS

The two VanA-type vancomycin-resistant E. faecium (VRE) strains C264 and I125 were isolated from in-patients in Chinese hospitals. The vancomycin-resistant conjugative plasmids pC264V and pI125V plasmids isolated from these strains carried the Tn1546-like element. The Tn1546-like element was found to contain the insertion sequences IS1216V and IS1542.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first molecular analysis of VanA-type VRE strains from patients resident in mainland China.

Mechanism of action of Tripterygium Wilfordii polyglycoside on experimental endometriosis

PURPOSE OF INVESTIGATION

This study was designed to examine the therapeutic effectiveness and mechanism of action of Tripterygium Wilfordii polyglycoside (TWP) in the treatment of endometriosis.

METHODS

An experimental endometriosis model was developed using New Zealand White rabbits where endometrial tissue was autotransplanted into the peritoneum. Six weeks after transplantation, a total of 22 rabbits were randomly placed into two groups: Group I (n=17) was treated with TWP (10 mg/kg/day) and Group 2 (n=5) served as the water-fed control for three successive months. The volume of endometrial implants was measured before and after administration of TWP and water. Immune and endocrine systems were investigated in the normal phase, six weeks after induction of endometriosis, and three months after TWP treatment and water administration.

RESULTS

After treatment with TWP, the average volume of endometrial implants significantly decreased (p < 0.0001), and the antiendometrial antibody (EmAb) level decreased (p < 0.05) to near normal levels, but it did not decrease in the untreated controls. Serum FSH and LH levels also decreased after TWP treatment. Furthermore, electron microscopic examination of the pituitary ultrastructure revealed morphological changes in gonadotropic cells (G-cell) after treatment with TWP, and changes gradually disappeared four weeks after withdrawal of TWP.

CONCLUSION

This study indicates that TWP has both hormonal and immune system action that is effective as a medical treatment for experimental endometriosis by modulating both reproductive endocrine functions and immunosuppression that results in remission of the disease.

[An AFLP marker related to fibrogenesis in upland cotton (Gossypium hirsuturm L.)]

By using AFLP technique polymorphism analysis was performed between a fuzzlesslintless mutant line and its isogenic wild-type line, Xuzhou 142. Out of 6,360 bands produced by 64 pairs primers, a fragment, named as CF1, appearing stably in wild-type line, Xuzhou 142. This polymorphism was further verified using several normal fiber varieties and F2, F3 populations from the cross of fuzzless-lintless mutant line with a high-lint-percentage variety Yumian No. 1. The cosegregation of CF1 and fibrogenesis was proved, which suggested that CF1 can be used as a molecular marker for cotton fibrogenesis. The CF1 segment was cloned into PUCm-T Vector and then sequenced. The putative amino acid sequences, is an analogue to phenol hydroxylase alpha subunit, outer surface protein C, NADH dehydrogenase subunit 1, NADH-ubiquinone oxidoreductase, 2-oxoacid ferredoxin oxidoreduct and hypothetical 14.5kD protein.

Usefulness of PCR in situ hybridization as a technique for morphological detection of human papillomavirus in uterine cervical neoplasia

This study was designed in order to devise fitting conditions in polymerase chain reaction (PCR)-in situ hybridization (ISH) for observing human papillomavirus (HPV) infection morphologically in uterine cervical neoplasias and to compare the detection rates of HPV by PCR-ISH and solution phase PCR (S-PCR) as well as fluorescence ISH (FISH). Tissues were obtained from 23 patients with cervical intraepithelial neoplasia 3, who visited our hospital between 1994 and 1997. To detect HPV-16, a HPVpF forward primer and a HPVp 16 reverse primer were used. Compared with the traditional methods, the PCR-ISH technique performed in this study was contrived as follows. To prevent detachment, the specimens were attached to silane-coated slides at 90 degrees C and successively left at room temperature for 36 hours. In proteopepsis, pepsin was used. PCR products were fixed with 4% paraformaldehyde. PCR-ISH, S-PCR, and FISH showed HPV-16 positivity in 52.2%, 56.5% and 21.7%, respectively. The positive rate of HPV-16 detected by PCR-ISH as well as S-PCR was significantly higher than that by FISH (p<0.01, respectively). There was no significant difference between the positive rates of HPV-16 detected by PCR-ISH and S-PCR. HPV-16 was detected by S-PCR in all 12 specimens in which HPV-16 expression was judged as positive using PCR-ISH. Similarly, HPV-16 was found by PCR-ISH in all five specimens in which HPV-16 expression was regarded as positive using FISH. While the FISH technique detected HPV-16 signals only in the superficial and middle layers of squamous cells, the PCR-ISH technique demonstrated them in all the layers including the parabasal and basal layers. The PCR-ISH technique contrived in this study has a high sensitivity to HPV-16 equal to that of S-PCR. The difference in detection rate and distribution of HPV DNA between PCR-ISH and FISH might suggest that HPV does not infect the superficial layer but rather the parabasal layer.

Primary non-Hodgkin's lymphoma of the uterine cervix

We present a patient with primary malignant lymphoma of the uterine cervix, which is extremely rare. She had a complete remission with a combination of chemotherapy and radiotherapy. Measurement of the serum soluble interleukin-2 receptor level was a useful index of the effectiveness of treatment.

[Action of fengsuidan granules on experimental anti-oral ulcer]

OBJECTIVE

To explore the anti-oral ulcer action, anti-inflammatory and analgesic effect of Fengsuidan Granules(FSDG).

METHODS

FSDG(0.5, 5.0, 10.0 g.kg-1) were administered to experimental animals. The oral ulcer in experimental animals was effected by means of white staphylococcus (sc) and carbolic acid (buming).

RESULTS

Such as acetic acid body turning, hot-plate, auricle inflammation by dimethylbenzene and foot swelling by egg white were used.

CONCLUSION

Following certain regularities of dose-effect relationship, FSDG has anti-oral ulcer effect, helps reduce and heal the ulcer and works efficaciously in analgesic and anti-inflammatory cases.

Central nervous system sodium channels are significantly suppressed at clinical concentrations of volatile anesthetics

BACKGROUND

Although voltage-dependent sodium channels have been proposed as possible molecular sites of anesthetic action, they generally are considered too insensitive to be likely molecular targets. However, most previous molecular studies have used peripheral sodium channels as models. To examine the interactions of volatile anesthetics with mammalian central nervous system voltage-gated sodium channels, rat brain IIA sodium channels were expressed in a stably transfected Chinese hamster ovary cell line, and their modification by volatile anesthetics was examined.

METHODS

Sodium currents were measured using whole cell patch clamp recordings. Test solutions were equilibrated with the test anesthetics and perfused externally on the cells. Anesthetic concentrations in the perfusion solution were determined by gas chromatography.

RESULTS

All anesthetics significantly suppressed sodium currents at clinical concentrations. This suppression occurred through at least two mechanisms: (1) a potential-independent suppression of resting or open sodium channels, and (2) a hyperpolarizing shift in the voltage-dependence of channel inactivation resulting in a potential-dependent suppression of sodium currents. The voltage-dependent interaction results in IC50 values for anesthetic suppression of sodium channels that are close to clinical concentrations at potentials near the resting membrane potential.

Voltage- and frequency-dependent pentobarbital suppression of brain and muscle sodium channels expressed in a mammalian cell line

The voltage- and frequency-dependent interactions of pentobarbital with voltage-gated sodium channels were examined in whole-cell patch-clamp recordings. Using rat brain IIA and rat muscle rSkM1 sodium channels expressed in stably transfected Chinese hamster ovary cell lines, it was found that pentobarbital reduced peak inward sodium currents with IC50 values of 1.2 mM (brain) and 1.0 mM (muscle). Analysis of steady state channel availability curves revealed two distinct effects of pentobarbital on both channel isoforms, i.e., a voltage-independent current reduction and an additional hyperpolarizing shift in the voltage dependence of channel availability. The latter effect leads to a voltage dependence of pentobarbital potency. Pentobarbital was also found to slow channel recovery after depolarization, yielding an additional use-dependent component of current suppression. Use-dependent block was enhanced by higher stimulation frequencies, longer pulse durations, and more depolarized holding and pulse potentials. All effects were identical for both channels. These findings can be explained in terms of the modulated receptor hypothesis and are consistent with a preferential interaction of pentobarbital with the inactivated channel state. As a consequence, actual pentobarbital potency would depend largely on experimental conditions or, in vivo, on the physiological parameters of a particular cell.

The PML gene is linked to a megabase-scale insertion/deletion restriction fragment length polymorphism

The PML gene located on chromosome band 15q22 is involved with the RAR alpha locus (17q21) in a balanced reciprocal translocation uniquely observed in acute promyelocytic leukemia. Physical mapping studies by pulsed-field gel electrophoresis revealed that the PML gene is flanked by two CpG islands that are separated by a variable distance in normal individuals. Several lines of evidence demonstrate that this is the consequence of a large insertion/deletion polymorphism linked to the PML locus: (1) overlapping fragments obtained with a variety of rare-cutting restriction enzymes demonstrated the same variability in distance between the flanking CpG islands; (2) mapping with restriction enzymes insensitive to CpG methylation confirmed that the findings were not a consequence of variable methylation of CpG dinucleotides; (3) the polymorphism followed a Mendelian inheritance pattern. This polymorphism is localized 3' to the PML locus. There are five common alleles, described on the basis of BssHII fragments, ranging from 220 to 350 kb with increments of approximately 30 kb between alleles. Both heterozygous (61%) and homozygous (39%) patterns were observed in normal individuals. Megabase-scale insertion/deletion restriction fragment length polymorphisms are very rare and have been described initially in the context of multigene families. Such structures have been also reported as likely regions of genetic instability. High-resolution restriction mapping of this particular structure linked to the PML locus is underway.

Enormous knowledge base of disease diagnosis criteria

One of the problems in the development of the medical knowledge systems is the limitations of the system's knowledge. It is a common expectation to increase the number of diseases contained in a system. Using a high density knowledge representation method designed by us, we have developed the Enormous Knowledge Base of Disease Diagnosis Criteria (EKBDDC). It contains diagnostic criteria of 1,001 diagnostic entities and describes nearly 4,000 items of diagnostic indicators. It is the core of a huge medical project--the Electronic-Brain Medical Erudite (EBME). This enormous knowledge base was implemented initially on a low-cost popular microcomputer, which can aid in the prompting of typical disease and in teaching of diagnosis. The knowledge base is easy to expand. One of the main goals of EKBDDC is to increase the number of diseases included in it as far as possible using a low-cost computer with a comparatively small storage capacity. For this, we have designed a high density knowledge representation method. Criteria of various diagnostic entities are respectively stored in different records of the knowledge base. Each diagnostic entity corresponds to a diagnostic criterion data set; each data set consists of some diagnostic criterion data values (Table 1); each data is composed of two parts: integer and decimal; the integral part is the coding number of the given diagnostic information, and the decimal part is the diagnostic value of this information to the disease indicated by corresponding record number. For example, 75.02: the integer 75 is the coding number of "hemorrhagic skin rash"; the decimal 0.02 is the diagnostic value of this manifestation for diagnosing allergic purpura. TABULAR DATA, SEE PUBLISHED ABSTRACT. The algebraic sum method, a special form of the weighted summation, is adopted as mathematical model. In EKBDDC, the diagnostic values, which represent the significance of the disease manifestations for diagnosing corresponding diseases, were determined empirically. It is of a great economical, practical, and technical significance to realize enormous knowledge bases of disease diagnosis criteria on a low-cost popular microcomputer. This is beneficial for the developing countries to popularize medical informatics. To create the enormous international computer-aided diagnosis system, one may jointly develop the unified modules of disease diagnosis criteria used to "inlay" relevant computer-aided diagnosis systems. It is just like assembling a house using prefabricated panels.

Pulsed-field gel electrophoresis analysis of retinoic acid receptor-alpha and promyelocytic leukemia rearrangements. Detection of the t(15;17) translocation in the diagnosis of acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is characterized cytogenetically by a balanced reciprocal chromosomal translocation t(15;17) (q22;q21). This translocation involves the retinoic acid receptor-alpha (RAR-alpha) on chromosome 17 and the promyelocytic leukemia locus (PML) on chromosome 15 and results in the transcription of novel fusion messenger RNAs. In this study, pulsed-field gel electrophoresis (PFGE) was applied to the detection of the t(15;17) translocation in twenty-six clinical specimens cytologically diagnosed by French-American-British criteria as APL. This technique could readily be applied to both fresh and nonviably frozen tumor samples. In 24 of 26 samples, rearrangements of the PML and RAR-alpha, loci could be detected by Southern blotting after digestion with MluI and BssHII. Furthermore, co-migration of the rearranged fragments, detected by hybridization to probes for the PML and RAR-alpha genes, demonstrated that these loci were juxtaposed. The translocation was detected in specimens at the time of initial diagnosis, on differentiation therapy with retinoic acid and at the time of relapse. The diagnostic accuracy was compared to cytogenetics and the reverse transcriptase-polymerase chain reaction for the novel PML-RAR-alpha fusion transcript. The samples from two patients were negative by all three diagnostic methods, and both of these patients failed to respond to all-trans retinoic acid. In the other 24 APL samples, cytogenetics was positive in only 76.9% of the cases, whereas both reverse transcriptase-polymerase chain reaction and PFGE methods detected the translocation in 100% of the cases. Thus, PFGE can readily detect the t(15;17) translocation in both viable and nonviable clinical specimens and can improve the diagnostic accuracy of morphology and cytogenetics in APL. In contrast to conventional electrophoresis based on rearrangement of RAR-alpha, the ability to demonstrate directly co-migration of the PML and RAR-alpha loci enables this method to distinguish the t(15;17) translocation from variant translocations such as the t(11;15). Because PFGE can be performed on nonviable, frozen tumor samples, it could be diagnostically useful in APL when the RNA-based reverse transcriptase-polymerase chain reaction cannot be performed.

[Plant regeneration from hypocotyl protoplasts of Lycium barbarum L]

The hypocotyl protoplasts of Lycium barbarum L. CV. Ningji No. 1 were isolated in an enzyme mixture solution containing 1% cellulase and 1% pectinase. The protoplasts were cultured in KM 8 p liquid medium containing 0.3 mg/L 2,4-D and 0.3 mg/L BA, The first division of regenerated cells occurred 3 days after culture. The small cell clumps could be observed by naked eyes 20 days after culture. 40 days after culture, microcalli of 1-2 mm in size were transferred to MS solid differentiation medium containing 3% sugar, 0.1-0.4 mg/L BA and 0.05-0.1 mg/L NAA. About 30 days after culture on MS solid medium, the calli with shoots were transferred to 1/2 MS medium containing 0.1 mg/L BA and 0.2 mg/L IBA, from which 80% of them differentiated roots and regenerated whole plantlets.