Is recovery enhancement after gastric cancer surgery really a safe approach for elderly patients?

BACKGROUND: This study aimed to evaluate the safety of enhanced recovery after surgery (ERAS) in elderly patients with gastric cancer (GC). AIM: To evaluate the safety of ERAS in elderly patients with GC. METHODS: The PubMed, EMBASE, and Cochrane Library databases were used to search for eligible studies from inception to April 1, 2023. The mean difference (MD), odds ratio (OR) and 95% confidence interval (95%CI) were pooled for analysis. The quality of the included studies was evaluated using the Newcastle-Ottawa Scale scores. We used Stata (V.16.0) software for data analysis. RESULTS: This study consists of six studies involving 878 elderly patients. By analyzing the clinical outcomes, we found that the ERAS group had shorter postoperative hospital stays (MD = -0.51, I2 = 0.00%, 95%CI = -0.72 to -0.30, P = 0.00); earlier times to first flatus (defecation; MD = -0.30, I² = 0.00%, 95%CI = -0.55 to -0.06, P = 0.02); less intestinal obstruction (OR = 3.24, I2 = 0.00%, 95%CI = 1.07 to 9.78, P = 0.04); less nausea and vomiting (OR = 4.07, I2 = 0.00%, 95%CI = 1.29 to 12.84, P = 0.02); and less gastric retention (OR = 5.69, I2 = 2.46%, 95%CI = 2.00 to 16.20, P = 0.00). Our results showed that the conventional group had a greater mortality rate than the ERAS group (OR = 0.24, I2 = 0.00%, 95%CI = 0.07 to 0.84, P = 0.03). However, there was no statistically significant difference in major complications between the ERAS group and the conventional group (OR = 0.67, I2 = 0.00%, 95%CI = 0.38 to 1.18, P = 0.16). CONCLUSION: Compared to those with conventional recovery, elderly GC patients who received the ERAS protocol after surgery had a lower risk of mortality.

Early postoperative complications after transverse colostomy closure, a retrospective study.

BACKGROUND: Ostomy is a common surgery usually performed to protect patients from clinical symptoms caused by distal anastomotic leakage after colorectal cancer (CRC) surgery and perforation or to relieve intestinal obstruction. AIM: To analyze the complications after transverse colostomy closure. METHODS: Patients who underwent transverse colostomy closure from Jan 2015 to Jan 2022 were retrospectively enrolled in a single clinical center. The differences between the complication group and the no complication group were compared. Logistic regression analyses were conducted to find independent factors for overall complications or incision infection. RESULTS: A total of 102 patients who underwent transverse colostomy closure were enrolled in the current study. Seventy (68.6%) patients underwent transverse colostomy because of CRC related causes. Postoperative complications occurred in 30 (29.4%) patients and the most frequent complication occurring after transverse colostomy closure was incision infection (46.7%). The complication group had longer hospital stays (P < 0.01). However, no potential risk factors were identified for overall complications and incision infection. CONCLUSION: The most frequent complication occurring after transverse colostomy closure surgery in our center was incision infection. The operation time, interval from transverse colostomy to reversal, and method of anastomosis might have no impact on the postoperative complications. Surgeons should pay more attention to aseptic techniques.

[Risk factors for hemorrhagic cystitis in children with ß-thalassemia major after allogeneic hematopoietic stem cell transplantation]. / 重型ßåœ°ä¸­æµ·è´«è¡€å„¿ç«¥å¼‚åŸºå› é€ è¡€å¹²ç»†èƒžç§»æ¤åŽå¹¶å‘å‡ºè¡€æ€§è†€èƒ±ç‚Žçš„å±é™©å› ç´ åˆ†æž.

OBJECTIVES: To explore the risk factors for hemorrhagic cystitis (HC) in children with ß-thalassemia major (TM) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: A retrospective analysis was conducted on clinical data of 247 children with TM who underwent allo-HSCT at Shenzhen Children's Hospital from January 2021 to November 2022. The children were divided into an HC group (91 cases) and a non-HC group (156 cases) based on whether HC occurred after operation. Multivariable logistic regression analysis was used to explore the risk factors for HC, and the receiver operating characteristic curve was used to analyze the predictive efficacy of related factors for HC. RESULTS: Among the 247 TM patients who underwent allo-HSCT, the incidence of HC was 36.8% (91/247). Univariate analysis showed age, incompatible blood types between donors and recipients, occurrence of acute graft-versus-host disease (aGVHD), positive urine BK virus deoxyribonucleic acid (BKV-DNA), and ≥2 viral infections were associated with the development of HC after allo-HSCT (P<0.05). Multivariable analysis revealed that incompatible blood types between donors and recipients (OR=3.171, 95%CI: 1.538-6.539), occurrence of aGVHD (OR=2.581, 95%CI: 1.125-5.918), and positive urine BKV-DNA (OR=21.878, 95%CI: 9.633-49.687) were independent risk factors for HC in children with TM who underwent allo-HSCT. The receiver operating characteristic curve analysis showed that positive urine BKV-DNA alone or in combination with two other risk factors (occurrence of aGVHD, incompatible blood types between donors and recipients) had a certain accuracy in predicting the development of HC after allo-HSCT (area under the curve >0.8, P<0.05). CONCLUSIONS: Incompatible blood types between donors and recipients, occurrence of aGVHD, and positive urine BKV-DNA are risk factors for HC after allo-HSCT in children with TM. Regular monitoring of urine BKV-DNA has a positive significance for early diagnosis and treatment of HC.

Quality and educational content of Douyin and TikTok short videos on early screening of rectal cancer.

Background and Aim: The aim of this study was to assess the quality and content of videos on Douyin and TikTok for their educational role on early screening of rectal cancer (RC). Methods: We conducted a search for videos related to RC on the Douyin and TikTok applications on 20 April 2023. The search was conducted in Chinese on Douyin and in English and Japanese on TikTok. A sample of the first 100 videos recommended by the software was selected for each language group. The content of the videos was evaluated using a content scorecard, while the quality of the videos was assessed using DISCERN. Subsequently, we conducted two partial correlations: one between the DISCERN score and the number of likes, and another between the video content score and the number of likes. Results: This study encompassed a total of 89 Chinese, 54 English, and 51 Japanese videos. After selection, 78 Chinese, 38 English, and 25 Japanese videos were identified to contain content related to early screening for RC, prompting further quality assessment. Notably, videos in the Chinese language showed the highest DISCERN score (P < 0.05). In terms of partial correlation analysis, it was observed that both the content score and DISCERN score did not show a significant correlation with the number of likes (P > 0.05). Conclusion: In terms of quality score and content score, the Chinese videos on Douyin show superiority over the English and Japanese videos on TikTok. However, there is potential for improving the overall appeal of the Chinese videos.

Reduced delay in diagnosis of odontogenic keratocysts with malignant transformation: A case report.

BACKGROUND: In rare cases, odontogenic keratocysts (ODs) transform into squamous cell carcinoma. Intervals between the first attendance of a patient and the diagnosis of OD with malignant transformation vary from weeks to years. In this article, we report a case of malignancy derived from OD with a five-day delay in diagnosis. CASE SUMMARY: A 54-year-old woman was referred to Tongji Hospital in Wuhan, China with complaints of moderate pain, recurrent swelling, and pus discharge around her left maxillary lateral incisor for over 10 years. Physical examination revealed a fistula at the palatine-side mucoperiosteum of the left maxillary lateral incisor and enlarged lymph node in the left neck. Cone beam computed tomography revealed a cystic lesion with massive bone destruction from the left maxillary central incisor to the left secondary maxillary premolar and local bony destruction in the left first mandibular molar. The patient was clinically diagnosed with OD. Enucleation rather than marsupialization was performed given the risk factors of long history, recent aggravated pain, and massive bony destruction. Malignant transformation of OD was confirmed by pathologists 3 d after the operation. Radical surgery was performed, and lymph node metastasis was observed. The patient was subjected to postoperative radiotherapy and synchronous chemotherapy, and no local recurrence or distant metastasis was noted at one-year follow-up. CONCLUSION: Our case suggests that clinicians should be aware of the malignant transformation of OD, especially when patients present with a long history, massive cyst, chronic inflammation, recent persistent infections, aggravated pain, numbness around the cystic lesion, and lymph node enlargement.

Biomineralization Precursor Carrier System Based on Carboxyl-Functionalized Large Pore Mesoporous Silica Nanoparticles.

Bone and teeth are derived from intrafibrillarly mineralized collagen fibrils as the second level of hierarchy. According to polymer-induced liquid-precursor process, using amorphous calcium phosphate precursor (ACP) is able to achieve intrafibrillar mineralization in the case of bone biomineral in vitro. Therefore, ACP precursors might be blended with any osteoconductive scaffold as a promising bone formation supplement for in-situ remineralization of collagens in bone. In this study, mesoporous silica nanoparticles with carboxyl-functionalized groups and ultra large-pores have been synthesized and used for the delivery of liquid like biomimetic precursors (ACP). The precursor delivery capacity of the nanoparticles was verified by the precursor release profile and successful mineralization of 2D and 3D collagen models. The nanoparticles could be completely degraded in 60 days and exhibited good biocompatibility as well. The successful translational strategy for biomineralization precursors showed that biomineralization precursor laden ultra large pore mesoporous silica possessed the potential as a versatile supplement in demineralized bone formation through the induction of intrafibrillar collagen mineralization.

[Randomized controlled trial of internal heat-type acupuncture needle therapy in the treatment of post-stroke shoulder pain].

OBJECTIVE: To evaluate the effectiveness and safety of internal heat-type acupuncture needle (IHTAN) the-rapy in the treatment of post-stroke shoulder pain in apopletic patients. METHODS: According to the random number table, 96 patients with post-stroke shoulder pain were divided into IHTAN group and warm needle moxibustion group (n＝48 in each one). Jianyu (LI15), Jianliao (TE14), Jianzhen (SI9), Binao (LI14) and Ashi points (Extra) on the affected side were selected in the two groups. For patients of the IHTAN group, internal warmth controllable acupuncture needles were inserted into the above-mentioned acupoints, and then connected to an internal heat acupuncture apparatus for stimulating the acupoints at 42 ℃， 20 min every time, once a week, for 4 weeks. For patients of the warm needle moxibustion group, the above mentioned acupoints were stimulated with filiform needles attached with an ignited moxa-stick, once every other day, for 4 weeks. If the shoulder pain disappeared or basically disappeared, it was considered to be healed, if the pain was relieved, it was considered to be effective, ot-herwise, it was considered to be ineffective. The incidence of local skin injury including burn, empyrosis, silt blue, hematoma and infection, the heart rate, respiration, blood pressure, oxyhemoglobin saturation, blood routine (hemoglobin level, white blood cell [WBC] count, platelet count), creatase and dipolymer levels were recorded or detected. Additionally, the patients' satisfaction rate about the treatment environment was recorded. RESULTS: Following the treatment, of the 45 and 47 cases in the warm needle moxibustion and IHTAN groups, 5 (11.11%) and 20 (42.55%) were cured, 26(57.78%) and 21(44.68%) experienced marked improvement, and 14 (31.11%) and 6 (12.77%) had no apparent changes in their shoulder pain severity, with the total effective rates being 68.89% and 87.23%, respectively. The curative rate and total effective rate of the IHTAN group were significantly higher than those of the warm needle moxibustion group (P<0.01，P<0.05). The incidence of skin injury of the IHTAN group was evidently lower than that of the warm needle moxibustion group (P<0.01), and the patients' therapeutic environment satisfaction rate was remarkably higher in the IHTNA group than in the warm needle moxibustion group (P<0.05). No significant differences were found between the two groups and between pre- and post-treatment in each group in the heart rate, respiration frequency, systolic and diastolic pressures, oxyhemoglobin saturation, hemoglobin content, WBC count, platelet count, and plasma dipolymer, creatine kinase, lactic dehydrogenase, and beta-hydroxybutyrate dehydrogenase levels (P>0.05). CONCLUSION: The IHTAN therapy is effective, safe and reliable in the treatment of post-stroke shoulder pain. In terms of the incidence of skin injury and the satisfaction degree of therapeutic environment, the internal heat-type acupuncture needle therapy is obviously superior to the warm needle moxibustion therapy.

[Short-term and long-term therapeutic effects of internal heat-type acupuncture needle therapy combined with acupoint injection of O3 for post-stroke shoulder pain].

OBJECTIVE: To observe the short-term and long-term therapeutic effects of internal heat-type acupuncture needle (IHTAN) therapy combined with acupoint injection of O3for post-stroke shoulder pain in apopletic patients. METHODS: Patients with post-stroke shoulder pain were divided into warm needle moxibustion ＋ acupoint injection group (29 cases), acupoint injection group (30 cases) and IHTAN＋acupoint injection group (29 cases) according to the random number table. For acupoint injection, O3 solution (3 mL, 30 µg/mL) was injected into Jianyu (LI15), Jianliao (SJ14), Jianzhen (LI9), Binao (LI14) and Ashi points (4-6 acupoints every time) on the affected side, once every other day for 4 weeks. For warm needle moxibustion, the above mentioned acupoints were stimulated with filiform needles attached with an ignited moxa-stick, once every other day for 4 weeks. For IHTAN, the internal warmth controllable acupuncture needles were inserted into the above mentioned acupoints on the affected side, and then connected to an internal heat acupuncture apparatus for stimulating the acupoints at 42 ℃， 20 min every time, once a week, for 4 weeks. The severity of shoulder pain was assessed by using visual analogue scale (VAS, 0-10 points), the upper limb joint motion function evaluated using Fugl-Meyer assessment scale (FMA, 0－66 points), and the ability of daily living activities (ADL) evaluated using Barthel index (0－100 points) at the ends of the 2nd and 4th week as well as the 6th month after the treatment. If the shoulder pain disappeared or basically disappeared, it was considered to be healed. If the pain was relieved, it was considered to be effective. Otherwise, it was considered to be ineffective. RESULTS: At the ends of the 2nd and 4th week as well as the 6th month after the treatment, the VAS scores of the IHTAN＋acupoint injection group were significantly lower than those of the warm needle moxibustion＋acupoint injection and acupoint injection groups (P<0.05), and the FMA and ADL scores were significantly higher in the IHTAN＋acupoint injection group than in the other two groups (P<0.05). No significant differences were found between the warm needle moxibustion＋acupoint injection and the acupoint injection groups in the scores of VAS, FMA and ADL (P>0.05). Of the 29, 30 and 29 cases in the warm needle moxibustion＋acupoint injection, acupoint injection and IHTNA＋acupoint injection groups, 1, 0 and 7 cases at the 2nd week, 3, 2 and 12 cases at the 4th week, 4, 2 and 15 cases at the 6th month were cured; 15, 14 and 16 cases at the 2nd week, 17, 17 and 13 cases at the 4th week, and 18, 18 and 12 cases at the 6th month experienced marked improvement; 13, 16 and 6 cases at the 2nd week, 9, 11 and 4 cases at the 4th week, 7, 10 and 2 cases at the 6th month had no apparent changes in their shoulder pain severity, with the total effective rates at the 4th week and 6th month being 68.97% and 75.86%, 63.33% and 66.60%, and 86.21% and 93.10%, respectively. CONCLUSION: The internal heat-type acupuncture needle therapy combined with O3 acupoint injection has obvious short-term and long-term therapeutic effects for post-stroke shoulder pain and is obviously superior to warm needle moxibustion＋ acupoint injection and simple acupoint injection in relieving shoulder pain and improving upper limb motion function.

Bimodal antibacterial system based on quaternary ammonium silane-coupled core-shell hollow mesoporous silica.

Hollow mesoporous silica (HMS) have been extensively investigated as a biomaterial for drug delivery. The present study developed quaternary ammonium silane-grafted hollow mesoporous silica (QHMS) to create a metronidazole (MDZ) sustained delivery system, MDZ@QHMS, with bimodal, contact-kill and release-kill capability. The QHMS was assembled through a self-templating method. Metronidazole was incorporated within the QHMS core using solvent evaporation. Antibacterial activities of the MDZ@QHMS were investigated using single-species biofilms of Staphylococcus aureus (ATCC25923), Escherichia coli (ATCC25922) and Porphyromonas gingivalis (ATCC33277). The MDZ@QHMS maintained a hollow mesoporous structure and demonstrated sustained drug release and bacteridal actvity against the three bacterial strains at a concentration of 100 µg/mL or above. These nanoparticles were not relatively cytotoxic to human gingival fibroblasts when employed below 100 µg/mL. Compared with HMS, the MDZ@QHMS system at the same concentration demonstrated antibiotic-elution and contact-killing bimodal antibacterial activities. The synthesized drug carrier with sustained, bimodal antibacterial function and minimal cytotoxicity possesses potential for localized antibiotic applications. STATEMENT OF SIGNIFICANCE: The present study develops quaternary ammonium silane-grafted hollow mesoporous silica (QHMS) to create a metronidazole (MDZ) sustained delivery system, MDZ@QHMS, with bimodal, contact-kill and release-kill capability. This system demonstrates sustained drug release and maintained a hollow mesoporous structure. The synthesized drug carrier with sustained, bimodal antibacterial function and excellent biocompatibility possesses potential for localized antibiotic applications.

Translation of a solution-based biomineralization concept into a carrier-based delivery system via the use of expanded-pore mesoporous silica.

Mineralization of collagen fibrils using solution-based systems containing biomimetic analogs of matrix proteins to stabilize supersaturated calcium phosphate solutions have been predictably achieved in vitro. Solution-based systems have limitations when used for in-situ remineralization of human hypomineralized tissues because periodic replenishment of the mineralizing solution is infeasible. A carrier-based platform designed for delivering mineral precursors would be highly desirable. In the present work, mesoporous silica nanoparticles with expanded pores (eMSN; 14.8nm) were synthesized. Polyacrylic acid-stabilized amorphous calcium phosphate (PA-ACP) was generated from a supersaturated calcium and phosphate ion-containing solution, and chosen as the model mineralizing phase. After amine functionalization (AF) of the eMSN through a post-grafting method, the positively-charged AF-eMSN enabled loading of PA-ACP by electrostatic interaction. In-vitro cytotoxicity testing indicated that PA-ACP@AF-eMSN was highly biocompatible. The release kinetics of mineralization precursors from PA-ACP@AF-eMSN was characterized by an initial period of rapid calcium and phosphate release that reached a plateau after 120h. Intrafibrillar mineralization was examined using a 2-D fibrillar collagen model; successful mineralization was confirmed using transmission electron microscopy. To date, this is the first endeavor that employs expanded-pore mesoporous silica to deliver polymer-stabilized intermediate precursors of calcium phosphate for intrafibrillar mineralization of collagen. The carrier-based delivery system bridges the gap between contemporary solution-based biomineralization concepts and clinical practice, and is useful for in-situ remineralization of bone and teeth. STATEMENT OF SIGNIFICANCE: Concepts of collagen biomineralization have been reasonably well established in the past few years and intrafibrillar mineralization of collagen fibrils can be predictably achieved with analogs of matrix proteins using solution-based systems. However, solution-based systems have their limitations in clinical applications that require direct application of mineralization precursors in-situ because periodic replenishment of the mineralizing solution is impossible. The present work presents for the first time, the use of amine-functionalized mesoporous silica with expanded pores for loading and release of polyacid-stabilized amorphous calcium phosphate mineralization precursors, and for intrafibrillar mineralization of type I collagen fibrils. This strategy represents an important step in the translational application of contemporary biomineralization concepts for in-situ remineralization of bone and teeth.

Biomimetic Intrafibrillar Mineralization of Type I Collagen with Intermediate Precursors-loaded Mesoporous Carriers.

Limited continuous replenishment of the mineralization medium is a restriction for in-situ solution-based remineralization of hypomineralized body tissues. Here, we report a process that generated amine-functionalized mesoporous silica nanoparticles for sustained release of biomimetic analog-stabilized amorphous calcium phosphate precursors. Both two-dimensional and three-dimensional collagen models can be intrafibrillarly mineralized with these released fluidic intermediate precursors. This represents an important advance in the translation of biomineralization concepts into regimes for in-situ remineralization of bone and teeth.

One-pot synthesis of antibacterial monomers with dual biocidal modes.

OBJECTIVES: The present study reported a method for preparing a blend of antibacterial quaternary ammonium silanes and quaternary ammonium methacryloxy silane (QAMS) based on the sol-gel reaction between dimethyldiethoxy silane and two trialkoxysilanes, one with an antibacterial quaternary ammonium functionality and the other with a methacryloxy functionality. METHODS: Reaction products of the sol-gel reaction were characterised by direct infusion mass spectrometry, FTIR and proton, carbon and silicon NMR. This blend of monomers was incorporated into an experimental universal adhesive for evaluation of antimicrobial activity against Streptococcus mutans biofilms, microtensile bond strength and cytotoxicty. Retention of quaternary ammonium species on polymerised adhesive, leaching of these species from the adhesive and the ability of resin-dentine interfaces to inhibit S. mutans biofilms were evaluated over a 3-month water-ageing period. RESULTS: The antibacterial adhesive version killed bacteria in S. mutans biofilms not only through the release of non-copolymerisable quaternary ammonium silane species (release-killing), but also via immobilised quaternary ammonium methacryloxy silane that are copolymerised with adhesive resin comonomers (contact-killing). Contact-killing was retained after water-ageing. The QAMS-containing universal adhesive has similar tensile bond strength as the control and two commercially available universal adhesives, when it was used for bonding to dentine in the etch-and-rinse mode and self-etching mode. Incorporation of the antimicrobial quaternary ammonium species blend did not adversely affect the cytotoxicity of the universal adhesive formulation. CONCLUSIONS: Instead of using quaternary ammonium dimethacrylates and nanosilver, an alternative bimodal antimicrobial strategy for formulating antimicrobial universal dentine adhesives is achieved using the one-pot sol-gel synthesis scheme. CLINICAL SIGNIFICANCE: The QAMS containing universal dentine adhesives with dual antimicrobial activity is a promising material aimed at preventing second caries and prolonging the longevity of resin composite restorations.

Effects of different sonic activation protocols on debridement efficacy in teeth with single-rooted canals.

OBJECTIVES: The effects of different EndoActivator® (EA) sonic activation protocols on root canal debridement efficacy were examined. METHODS: Root canals in 48 single-rooted teeth were instrumented, irrigated initially with NaOCl and divided into 6 groups (N=8) based on the application time of QMix (antimicrobial calcium-chelating irrigant), and the time and sequence of EA irrigant activation - Positive Control: 90s QMix; Negative Control: 90s saline; Group 1A: 15s QMix+15s QMix with EA-activation; Group 1B: 30s QMix+30s of QMix with EA-activation; Group 2A: 15s QMix with EA-activation+15s QMix; Group 2B: 30s QMix with EA-activation+30s QMix. Split roots were examined with scanning electron microscopy for assignment of smear and debris scores in locations along the coronal, middle and apical thirds of the canals. The overall cleanliness of pooled canal locations in the Positive Control and the 4 experimental groups were compared with chi-square tests. RESULTS: Significant differences were detected among the 5 groups (P<0.001). Post hoc pairwise comparisons indicated that the overall canal cleanliness was in the order (from best to worst): 1B=2B>2A>1A>Positive Control. Completely clean canals could not be achieved due to the absence of continuous irrigant flow for EA to clear intraradicular debris. CONCLUSIONS: Irrespective of the sonic activation sequence, irrigant activation for 30s during a 60-s period of QMix application appears to maximise the smear layer and debris removal potential of the EndoActivator® system. CLINICAL SIGNIFICANCE: Sonic activation of root canal irrigants produces cleaner root canals and reduces the time required for final delivery of a canal wall smear later-removing irrigant when compared to the use of needle irrigation alone.

Noscapine induces mitochondria-mediated apoptosis in gastric cancer cells in vitro and in vivo.

PURPOSE: Noscapine plays an important role in the regulation of cell growth and death. It has been reported to potentiate the anti-tumor effect by inducing apoptosis in various malignant cells. However, the mechanism of inducing apoptosis in gastric cancer cells by this agent remains to be clarified. METHODS: In the study, we investigated the signaling pathways by which noscapine induces apoptosis in gastric cancer cell lines. Apoptosis of four human gastric cancer cell lines was induced by treatment with noscapine. RESULTS: Our results indicate that noscapine induced a dose-dependent apoptosis of these cells. The treatment with noscapine upregulated Bax and Cytochrome c (Cyt-c) protein, downregulated Bcl-2 protein. Caspase-3 and caspase-9 were activated, suggesting that the apoptosis is mediated by mitochondrial pathways. Moreover, in xenograft tumor mouse model, noscapine injection successfully inhibited the tumor growth via apoptosis induction which was demonstrated by TUNEL assay. CONCLUSIONS: These data of the study suggest that noscapine induces apoptosis in gastric cancer cells via mitochondrial pathways.

[Effect of electroacupuncture of different acupoints on the excitability of detrusor muscle and the expression of BDNF and TrkB in the spinal cord of rats with urinary retention due to spinal cord injury].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of different acupoints on the expression of brain-derived neurotrophic factor (BDNF) and tropomyosine receptor kinase B (TrkB) in the spinal cord and the excitability of detrusor muscle of the uninary bladder in rats with urinary retention owing to spinal cord injury (SCI). METHODS: A total of 100 female SD rats were randomly divided into normal, sham-operation (sham), model, EA-Guanyuan (CV 4), and EA-Shuidao (ST 28) groups, with 20 cases in each. SCI induced urinary retention model was established by using weight dropping method. EA (1 mA, 2 Hz/15 Hz) was applied to "Guanyuan" (CV 4) and "Shuidao" (ST 28) respectively for 20 min, once a day for 10 days. The excitability (tone, contraction frequency) of the detrusor muscle of the bladder was detected in vitro by using electrophysiological method, and the expression of BDNF and TrkB in spinal cord was determined by immunohistochemistry staining. RESULTS: In comparison with normal control and sham groups, the tension and the contraction frequency of detrusor muscle in model group lowered significantly (P<0.05), while compared with model group, both the tension and contraction frequency of detrusor muscle increased pronouncedly in EA-CV 4 and EA-ST 28 groups (P<0.05), and the effect of EA-CV 4 was apparently superior to that of EA-ST 28 (P<0.05). In comparison with normal and sham groups, the BDNF and TrkB immunoreaction positive cells in the spinal cord were significantly more in model group (P<0.05). Compared with model group, those of EA-CV 4 and EA-ST 28 groups were obviously further increased (P<0.05), and the effect of EA-CV 4 group was markedly superior to that of EA-ST 28 group (P<0.05). CONCLUSION: EA of CV 4 and ST 28 can raise the excitability of the smooth muscle of the uninary bladder in rats with SCI-induced urinary retention, which may be related to its effects in upregulating the expression of BDNF and TrkB in the spinal cord. The effects of EA of CV 4 were evidently superior to those of EA of ST 28.

Permeability calculations in three-dimensional isotropic and oriented fiber networks.

Hydraulic permeabilities of fiber networks are of interest for many applications and have been studied extensively. There is little work, however, on permeability calculations in three-dimensional random networks. Computational power is now sufficient to calculate permeabilities directly by constructing artificial fiber networks and simulating flow through them. Even with today's high-performance computers, however, such an approach would be infeasible for large simulations. It is therefore necessary to develop a correlation based on fiber volume fraction, radius, and orientation, preferably by incorporating previous studies on isotropic or structured networks. In this work, the direct calculations were performed, using the finite element method, on networks with varying degrees of orientation, and combinations of results for flows parallel and perpendicular to a single fiber or an array thereof, using a volume-averaging theory, were compared to the detailed analysis. The detailed model agreed well with existing analytical solutions for square arrays of fibers up to fiber volume fractions of 46% for parallel flow and 33% for transverse flow. Permeability calculations were then performed for isotropic and oriented fiber networks within the fiber volume fraction range of 0.3%-15%. When drag coefficients for spatially periodic arrays were used, the results of the volume-averaging method agreed well with the direct finite element calculations. On the contrary, the use of drag coefficients for isolated fibers overpredicted the permeability for the volume fraction range that was employed. We concluded that a weighted combination of drag coefficients for spatially periodic arrays of fibers could be used as a good approximation for fiber networks, which further implies that the effect of the fiber volume fraction and orientation on the permeability of fiber networks are more important than the effect of local network structure.