Effects of Stamm gastrostomy on gastric emptying rate in rats

AIM: Although frequency of gastroesophageal reflux (GER) increases after gastrostomy, the role of gastric emptying in GER has not been evaluated. In this study, we examined the effects of Stamm gastrostomy on gastric emptying rate in rats and whether Stamm gastrostomy induces GER or not. METHODS: Sprague-Dawley rats were divided into three groups. Stamm gastrostomy was done in the first group (SG). Sham operation was carried out in group 2 and the 3rd group served as control. Gastric emptying was assessed using both liquid and solid meals in each group at postoperative 14th day. For solid meal emptying, after fasting of 16 h, the rats were fed for 3 h and gastric emptying rate was measured at the fifth hour. Methylcellulose was used for emptying of liquids and it was given after the animals were fasted for 16 h and gastric emptying rate was measured 30 min later. Histological evaluation for GER was performed in all groups. RESULTS: GER was observed pathophysiologically in 5 of the 7 rats in SG group. Gastric emptying rates of liquid and solid meals were found to be similar in control, SG or sham groups. CONCLUSION: Surgical gastrostomy does not affect the gastric emptying of solid and liquid meals in rats. Other mechanisms should be considered in the development of GER observed following gastrostomy.     

Sost downregulation and local Wnt signaling are required for the osteogenic response to mechanical loading

Sclerostin, the Wnt signaling antagonist encoded by the Sost gene, is secreted by osteocytes and inhibits bone formation by osteoblasts. Mechanical stimulation reduces sclerostin expression, suggesting that osteocytes might coordinate the osteogenic response to mechanical force by locally unleashing Wnt signaling. To investigate whether sclerostin downregulation is a pre-requisite for load-induced bone formation, we conducted experiments in transgenic mice (TG) engineered to maintain high levels of SOST expression during mechanical loading. This was accomplished by introducing a human SOST transgene driven by the 8 kb fragment of the DMP1 promoter that also provided osteocyte specificity of the transgene. Right ulnae were subjected to in vivo cyclic axial loading at equivalent strains for 1 min/day at 2 Hz; left ulnae served as internal controls. Endogenous murine Sost mRNA expression measured 24 h after 1 loading bout was decreased by about 50% in TG and wild type (WT) littermates. In contrast, human SOST, only expressed in TG mice, remained high after loading. Mice were loaded on 3 consecutive days and bone formation was quantified 16 days after initiation of loading. Periosteal bone formation in control ulnae was similar in WT and TG mice. Loading induced the expected strain-dependent increase in bone formation in WT mice, resulting from increases in both mineralizing surface (MS/BS) and mineral apposition rate (MAR). In contrast, load-induced bone formation was reduced by 70-85% in TG mice, due to lower MS/BS and complete inhibition of MAR. Moreover, Wnt target gene expression induced by loading in WT mice was absent in TG mice. Thus, downregulation of Sost/sclerostin in osteocytes is an obligatory step in the mechanotransduction cascade that activates Wnt signaling and directs osteogenesis to where bone is structurally needed.     

Scale‐up of MSC under hypoxic conditions for allogeneic transplantation and enhancing bony regeneration in a rabbit calvarial defect model

To realize the therapeutic potential of mesenchymal stem cells (MSCs), we aimed to develop a method for isolating and expanding New Zealand rabbit MSCs in a great scale. Rabbit MSCs expanded under hypoxic and normoxic conditions were compared in terms of replication capacity, differentiation potential, and the capacity for allogeneic transplantation in a calvarial defect model. The cells from all tested rabbits were expanded more rapidly when plated at low‐density under hypoxic conditions compared to under normoxic conditions. Moreover, cells expanded under hypoxic conditions increased in the potential of osteoblastic, adipocytic, and chondrocytic differentiation. More importantly, radiographic analysis and micro‐CT measurement of bone volume revealed the hypoxic cells when transplanted in the calvarial defects of another rabbit increased in the ability to repair bone defect compared to the normoxic cells. Six weeks after allogeneic transplantation of hypoxic MSCs, histological analysis revealed a callus spanned the length of the defect, and several bone tissues spotted in the implant. At 12 weeks, new bone had formed throughout the implant. Using BrdU labeling to track the transplanted cells, the hypoxic cells were more detected in the newly formed bone compared to the normoxic cells. For defects treated with allogeneic MSCs, no adverse host response could be detected at any time‐point. In conclusion, we have developed a robust method for isolation and expansion of rabbit MSCs by combining low‐density with hypoxic culture, which can be applied for the design of clinical trials in allogeneic transplantation of MSCs for bone healing. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1213–1220, 2012     

Multilevel Arthroplasty for Cervical Spondylosis: More Heterotopic Ossification at 3 Years of Follow-up

STUDY DESIGN.: Retrospective cohort study. OBJECTIVE.: To investigate the differences between single- and multilevel degenerative disc diseases (DDDs) treated with cervical arthroplasty. SUMMARY OF BACKGROUND DATA.: The US Food and Drug Administration clinical trials compared arthroplasty with anterior cervical discectomy and fusion for single-level DDD. However, cervical arthroplasty for multilevel DDD is rarely addressed in the literature. METHODS.: A total of 102 consecutive patients who underwent Bryan arthroplasty were divided into either a single- or multilevel group. Clinical outcomes were measured by the visual analogue scale (VAS) of neck and arm, and by the neck disability index with a minimum follow-up of 25 months. Every patient had radiographical evaluations, and computed tomography. RESULTS.: Eighty-six patients (84.3%) completed the follow-up with a mean time of 38.3 ± 8.7 months. Postoperatively, there were significant improvements in clinical outcomes (i.e., VAS neck, VAS arm, and neck disability index) at each time point of evaluation (i.e., 3-, 6-, 12-, and 24 mo postoperation). The sex composition and clinical outcome improvements between the single- and multilevel groups were not significantly different. The multilevel group was older (51.3 ± 8.6 vs. 46.3 ± 11.2 yr; P = 0.02), had more intraoperative blood loss (218.0 ± 182.4 vs. 102.8 ± 79.2 mL; P = 0.001), and demonstrated a higher rate of heterotopic ossification (HO) than the single-level group (66.0% vs. 25.0%; P < 0.001). The majority (97.7%) of the artificial discs in this series remained mobile despite HO. CONCLUSION.: Clinical outcomes of cervical arthroplasty in multilevel spondylosis are similar to single-level outcomes. However, the significantly higher rate of HO found in multilevel arthroplasty and its long-term effect warrant further investigation.     

连续性肾脏替代治疗中滤器后加热法对患者体温的影响

目的探讨连续性肾脏替代治疗(CRRT)中滤器后加热法对患者体温的影响。方法将60例行CRRT治疗的患者随机分为对照组和观察组各30例,对照组按常规将加温装置连接到置换液的管路上,观察组将加温装置连接到滤器后静脉端血液回输管路上。两组均于CRRT治疗开始3h、6h、12h时测量患者体温及深静脉置管的动、静脉端的血液温度;比较两组治疗前后溶血反应相关检验结果。结果在CRRT治疗不同时段,两组深静脉置管的动、静脉端的血液温度比较,干预主效应均P<0.05;治疗12h时观察组低体温发生率显著低于对照组(P<0.05)。两组治疗前后溶血反应相关检验结果比较,差异无统计学意义(均P>0.05)。结论滤器后加热血液回输管路的方式可安全有效地补充CRRT治疗中循环热量,降低CRRT治疗中低体温发生率。     

Incidence of acute kidney injury in hospitalized children

Objective To investigate the prevalence, missed diagnosis rate and causes of acute kidney injury (AKI) in hospitalized children, and its impact on hospitalization cost, length of stay and outcome. Methods The data of children admitted in Children's Hospital Affiliated to Capital Institute of Pediatrics from December 1st to 31st 2014 were collected, and those whose serum creatinine (Scr) were measured at least two times were selected. Patients were diagnosed as AKI according to the diagnostic criteria of 2012 Kidney Disease: Improving Global Outcomes, then divided into AKI group and non-AKI group, the former of which was further divided into AKI1 group (Scr peak value in normal range) and AKI2 group (Scr peak value above normal range). The causes and impact of AKI on hospitalization cost, length of stay and outcome in different groups were compared and analyzed. Results (1) Among 921 patients with at least two Scr results, 170 patients met with the diagnostic criteria of AKI, including 100 males and 70 females. There were 112(65.9%) in AKI stage 1, 43(25.3%) in stage 2, and 15(8.8%) in stage 3. The overall prevalence of AKI was 18.5%. With only 7 cases getting diagnosed, the diagnostic rate was 4.1%, while 95.9% of patients missed diagnosis. (2) Among AKI patients, 67 cases had pre-renal causes, 103 cases had intra-renal causes and mixed factors. 100(58.8%) cases got complete recovery, 34(20.0%) cases recovered partially and 36(21.2%) cases did not improve, including 4 cases of death. (3) The prevalence of AKI among those below 1-year old was higher than children elder than 1-year (23.0% vs 15.5%, P=0.004). The prevalence of AKI in surgical ward was higher than medical ward (30.7% vs 15.8%, P＜0.001). (4) Compared with those in non-AKI group, there was lower age [1.1(0.2, 3.5) year vs 2.0(0.3, 4.9) year] and higher hospitalization time[12.5(8.0, 20.0) d vs 8.0(6.0, 11.0) d], hospitalization costs [25 279.2(13 822.8, 48 856.7) yuan vs 12 616.9(8680.1, 19 345.1) yuan] and mortality (2.4% vs 0.3%) in AKI group (all P＜0.05). (5) There were 126 cases in AKI1 group and 44 cases in AKI2 group. The costs of hospitalization, outcome and mortality showed no difference between two groups (all P＞0.05). The hospitalization time in AKI2 group was shorter than that in AKI1 group (P=0.038). Conclusions Among hospitalized children the missed diagnosis rate of AKI is high. Pre-renal factor is the main cause of AKI. Children younger than 1-year old are more susceptible to AKI. AKI children have lower age and higher hospitalization time, hospitalization costs and mortality than non-AKI children. The effect of Scr fluctuation within normal levels needs to be further studied.     

母乳哺育支持系统对初产妇产后母乳喂养的影响

目的探讨母乳哺育支持系统对初产妇产后母乳喂养的影响。方法将69例自然分娩的初产妇随机分为观察组35例和对照组34例,观察组新生儿出生后给予持续性母婴皮肤接触1h,由母乳哺育支持团队成员提供母乳喂养护理支持,出院后哺乳顾问持续跟踪并给予帮助;对照组则行皮肤接触至产妇会阴伤口缝合并检查完毕,给予常规产后护理。比较产后不同时间纯母乳喂养率及母乳喂养率。结果观察组出院时、产后7d、4个月及6个月的纯母乳喂养率显著高于对照组(P0.05,P0.01),观察组产后7d、4个月及6个月的母乳喂养率显著高于对照组(均P0.05)。结论医院母乳哺育支持系统能有效提高初产妇产后纯母乳喂养率和母乳喂养率。     

R2: identification of renal potential progenitor/stem cells that participate in the renal regeneration processes of kidney allograft fibrosis

Aim: Many strategies are explored to ameliorate kidney allograft tubular atrophy and interstitial fibrosis (TA/IF), but little progress has been achieved. The latest evidence suggested that CD133+ cell in kidney represent a potential multipotent adult resident stem cell population that may contribute to the renal injury repair. Here we investigate whether the CD133+ cells exist in transplanted renal and exert a growth and self-repair procedure in TA/IF. Methods: Allografts from rat kidney transplant models were harvested at 4 weeks, 8 weeks and 12 weeks post transplantation. We performed immunohistochemistry to detect the CD133+ cells and immunofluorescence to detect the co-expression of CD133 or Pax-2 with Ki-67. We furthermore analysed the E-cadherin using serial sections. Results: CD133+ cells were seldom seen in control kidney, but distributed sporadically in the cortex parenchyma along with the deterioration of TA/IF. The number of CD133+ cell increased after 4 weeks and reached the peak at 8 weeks, then decreased at 12 weeks. From 8 weeks, some new tubules expressing E-cadherin were constructed with CD133+ cells. Almost all the CD133+ cells were Ki-67-positive, but not all the Ki-67+ cells expressed CD133. The rest Ki-67+ cells almost expressed Pax-2. Conclusion: Our study reveals that when majority of the tubules are damaged, a self-repair mechanism is evoked by potential adult stem cells to compensate the renal function. Thus, potential adult resident stem cells offer a new avenue for autologous cell therapies in TA/IF.     

C4d deposition is correlated with the level of antivimentin antibody in rat kidneys undergoing chronic allograft nephropathy

Aims

Antivimentin antibody is often produced as an autoantibody after transplantation. C4d deposition, a marker of humoral immunity during transplantation, is believed to reflect alloantibodies. This study investigated the relationship between C4d deposition and humoral immunity to vimentin among rat kidneys undergoing chronic allograft nephropathy (CAN).

Methods

Fisher 344 rat renal grafts were orthotopically transplanted into Lewis rats following the procedure of Kamada with our modification. All recipients were administered cyclosporine (CsA) (10 mg/kg⁻¹ · d⁻¹ × 10 d) before being divided into 3 groups of oral treatments: (1) vehicle, (2) CsA (6 mg/kg⁻¹ · d⁻¹), and (3) mycophenolate mofetil (MMF; 20 mg/kg⁻¹ · d⁻¹). At 4, 8 and 12 weeks after transplantation, the rats were killed, the renal allografts harvested, and the sera collected. Serum creatinine (SCr) was measured and pathologic changes assessed according to the Banff 97 criteria. The antivimentin antibody was quantified by enzyme-linked immunosorbent assay. The deposition of C4d detected by immunofluorescence was analyzed by integrated optical density (IOD).

Results

Antivimentin antibody was observed in sera of all transplanted rats. The level of antivimentin antibody (IgGΔOD) increased gradually during the development of CAN from 4 weeks. Simultaneously, C4d deposition in peritubular capillaries also progressively strengthened. There was a strong positive correlation between the content of antivimentin antibody and C4d deposition (r = 0.892; P = .000). MMF simultaneously decreased antivimentin antibody formation and C4d deposition. In contrast, CsA had no significant effect.

Conclusions

We demonstrated the production of antivimentin antibodies and the deposition of C4d during the development of CAN. There was a positive correlation between them. Whether humoral immunity to vimentin contributes to C4d deposition is not clear and further studies are needed to elucidate this issue.     

硫酸镁抑制经辐射后人脐静脉血管内皮细胞γ-H2AX的表达

目的 探讨不同浓度硫酸镁对照射后人脐静脉血管内皮细胞(human umbilical vein endothelial,HUVEC)存活率及γ-H2AX表达的影响。方法 CCK-8法检测不同浓度的硫酸镁对HUVEC存活率的影响;激光共聚焦显微镜检测4 Gy X射线照射后不同时间HUVEC中γ-H2AX簇集点(foci)的数量;流式细胞术和Western blot检测γ-H2AX蛋白的表达情况。结果 CCK-8法显示,1.25 mg/ml浓度的硫酸镁能提高照射后的细胞存活率(t=-6.34,P<0.05);细胞免疫荧光结果显示,照射后0.5~1 h foci焦点数达到最高值,平均达45个,随着时间的延长foci点数变少,强度减弱,具有时间依赖性,而硫酸镁在照后0.5、1、2、6、12 h均可以明显减少foci的形成(t=12.62、6.36、11.93、5.75、9.43,P<0.05);流式细胞仪检测表明,硫酸镁在照后0.5、1、2 h可以抑制X射线照射后γ-H2AX蛋白表达量的增加(t=6.07、5.32、11.85,P<0.05);Western blot结果与细胞免疫荧光结果一致。结论 硫酸镁可以增加照射后HUVEC的存活率,降低X射线诱导的DNA损伤蛋白γ-H2AX的表达。