[Incidence of postoperative complications in Chinese patients with gastric or colorectal cancer based on a national, multicenter, prospective, cohort study]

Objective: To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications. Methods: This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression. Results: The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion: Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.

[Improvement of China's legal system for public health emergency management from the perspective of lifecycle management]

A crucial lesson gained through the pandemic preparedness and response to COVID-19 is that all measures for epidemic control must be law-based. The legal system is related not only to public health emergency management per se but also to all aspects of the institutional supporting system throughout the lifecycle. Based on the lifecycle emergency management model, this article analyses the problems of the current legal system and the potential solutions. It is suggested that the lifecycle emergency management model shall be followed to establish a more comprehensive public health legal system and to gather the intelligence and consensus of experts with different expertise, including epidemiologists, sociologists, economists, jurist and others, which will collaboratively promote the science-based legislation in the field of epidemic preparedness and response for the establishment of a comprehensive legal system for public health emergency management and with Chinese characteristics.

Radiomics combined with clinical characteristics predicted the progression-free survival time in first-line targeted therapy for advanced non-small cell lung cancer with EGFR mutation

Objective

This study was to explore the most appropriate radiomics modeling method to predict the progression-free survival of EGFR-TKI treatment in advanced non-small cell lung cancer with EGFR mutations. Different machine learning methods may vary considerably and the selection of a proper model is essential for accurate treatment outcome prediction. Our study were established 176 discrimination models constructed with 22 feature selection methods and 8 classifiers. The predictive performance of each model were evaluated using the AUC, ACC, sensitivity and specificity, where the optimal model was identified.

Results

There were totally 107 radiomics features and 7 clinical features obtained from each patient. After feature selection, the top-ten most relevant features were fed to train 176 models. Significant performance variations were observed in the established models, with the best performance achieved by the logistic regression model using gini-index feature selection (AUC = 0.797, ACC = 0.722, sensitivity = 0.758, specificity = 0.693). The median R-score was 0.518 (IQR, 0.023–0.987), and the patients were divided into high-risk and low-risk groups based on this cut-off value. The KM survival curves of the two groups demonstrated evident stratification results (p = 0.000).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06019-x.

[Standardized implementation of minimally invasive surgery for Siewert Ⅱ esophagogastric junction adenocarcinoma]

The incidence of Siewert type II adenocarcinoma of the esophagogastric junction (AEG) is increasing year by year. Due to its special anatomical location and biological behavior, the treatment of AEG is still controversial in terms of lymph node dissection, the esophageal resection margin, range of gastrectomy, and the choice of reconstruction modality for postoperative gastrointestinal tract. The advent of the minimally invasive era has brought the treatment of Siewert type II AEG to a stage of gradual improvement and standardization. Experts of China are also actively exploring the value of minimally invasive surgery in the treatment of AEG through multicenter trials (CLASS-10, etc.). It is believed that based on the active development of many clinical studies, basic experimental studies and large prospective clinical studies, the strengthening of communication and cooperation among various disciplines and the innovative application of new technologies can bring greater survival benefits to patients.

[Research progress in endoluminal treatment of urethral stricture]

Urethral stricture is regarded as a common disease in urology whose treatment modalities usually include open surgery and endoluminal treatment. Endoluminal techniques have gradually become one of the essential treatments in urethral stricture due to easier operation, less trauma, faster recovery, higher safety and fewer complications. The popularity of plasma knife and laser, and the application of new urethral stents and grafts, make endoscopic surgery easier and less invasive. However, due to its anatomical particularity and diverse etiologies of urethral stricture, the endoluminal treatment is still not satisfactory and a considerable number of patients still experience poor long-term treatment effect. Non-operative managements, such as intracavitary brachytherapy, intracavitary injection of drugs or stem cells and new urinary catheters are also being explored in treating urethral stricture, which would improve the effect of endoscopic surgery. This review summarizes the clinical application and new progress of various kinds of endoluminal treatments and pharmacotherapy in urethral stricture at home and abroad. More prospective randomized controlled studies are needed to confirm its feasibility, effectiveness and optimal time of operation.

[Minimally invasive treatment with function preservation for submucosal tumors in the gastric cardia]

The detection rate of submucosal tumors in the gastric cardia increases year by year. Most of these tumors are benign or borderline tumors, among which leiomyoma and gastrointestinal stromal tumor are more common. The functional preservation of the gastric cardiac region is closely related to the anatomical structure of the esophagogastric junction. The esophageal reflux is mainly evaluated directly or indirectly by upper gastrointestinal radiography, gastroscopy, CT examination and manometric measurements of the lower esophagus. For tumors at this specific region, the risk of lymph node metastasis is very low, and according to the tumor free principle, usually only complete removal of the tumor is required. We aim to introduce the minimally invasive and function preserving procedures, including endoscopic therapy alone, laparoscopic and endoscopic cooperative surgery, and totally laparoscopic surgery. The selection of this tailored treatment should be based on the tumor location, size, shape and growth pattern (intraluminal or extraluminal), and the experience of the surgical team, so as to improve postoperative quality of life of the patients.

Organic trace minerals improve eggshell quality by improving the eggshell ultrastructure of laying hens during the late laying period

The objective of this study was to investigate the effects of low inclusion levels of organic trace minerals (iron, copper, manganese, and zinc) on performance, eggshell quality, serum hormone levels, and enzyme activities of laying hens during the late laying period. A total of 405 healthy hens (HY-Line White, 50-week-old) were randomly divided into 3 treatments, with 9 replications per treatment and 15 birds per replication. The dietary treatments included a basal diet supplemented with inorganic trace minerals at commercial levels (CON), a basal diet supplemented with inorganic trace minerals at 1/3 commercial levels (ITM), and a basal diet supplemented with proteinated trace minerals at 1/3 commercial levels (TRT). The trial lasted 56 D (8 wk). Compared with the CON group, the ITM group showed decrease in (P < 0.05) egg production, eggshell strength, eggshell palisade layer, palisade layer ratio, serum estrogen, luteinizing hormone, glycosaminoglycan concentration, and carbonic anhydrase activity and increase in (P < 0.05) egg loss and mammillary layer ratio. However, the TRT group almost kept all the indices close to the CON group (P > 0.05). Furthermore, hens fed with low inclusion levels of organic trace minerals had smaller mammillary knobs (P < 0.05) than those in the CON and ITM groups. In conclusion, hens fed with low inclusion levels of proteinated trace minerals had better performance and eggshell strength than those fed with identical levels of inorganic compounds; organic trace minerals improved eggshell quality by improving the eggshell ultrastructure of laying hens during the late laying period.

Optofluidic differential colorimetry for rapid nitrite determination

Nitrite detection plays a very important role in environmental monitoring and for industrial purposes. The commonly used colorimetric analysis requires the measurement of a system's calibration curve by asynchronously preparing and detecting a dozen standard samples, leading to time-consuming, slow and cumbersome procedures. Here, we present a differential colorimetry method that determines the nitrite level based on the paired chromaticity gradient, formed by coupling the colour reaction into the microfluidic network. The two gradients reshape each other and contain enough information for the quantitative analysis of the sample being tested, without the need for a calibration curve. The independence of the two gradients of the absorbance change caused by the detecting system and water quality results in a high stability and anti-interference performance, with the assistance of its self-correcting ability. This differential colorimetry method requires little time and energy consumption as only one sample is needed. Standard nitrite solutions of 0.50 mM and 0.33 mM have been determined with an error of 1.16% and 0.50%, respectively. These measurements are advantageous in terms of greater stability by up to 10 times and accuracy by 6 times, compared with the calibration curve approaches. It is foreseeable that this differential colorimetry method will find a wide range of applications in the field of chemical detection.

Optofluidic marine phosphate detection with enhanced absorption using a Fabry-Pérot resonator

Real-time detection of phosphate has significant meaning in marine environmental monitoring and forecasting the occurrence of harmful algal blooms. Conventional monitoring instruments are dependent on artificial sampling and laboratory analysis. They have various shortcomings for real-time applications because of the large equipment size and high production cost, with low target selectivity and the requirement of time-consuming procedures to obtain the detection results. We propose an optofluidic miniaturized analysis chip combined with micro-resonators to achieve real-time phosphate detection. The quantitative water-soluble components are controlled by the flow rate of the phosphate solution, chromogenic agent A (ascorbic acid solution) and chromogenic agent B (12% ammonium molybdate solution, 80% concentrated sulfuric acid and 8% antimony potassium tartrate solution with a volume ratio of 80 : 18 : 2). Subsequently, an on-chip Fabry-Pérot microcavity is formed with a pair of aligned coated fiber facets. With the help of optical feedback, the absorption of phosphate can be enhanced, which can avoid the disadvantages of the macroscale absorption cells in traditional instruments. It can also overcome the difficulties of traditional instruments in terms of size, parallel processing of numerous samples and real-time monitoring, etc. The absorption cell length is shortened to 300 μm with a detection limit of 0.1 μmol L^-1. The time required for detection is shortened from 20 min to 6 seconds. Predictably, microsensors based on optofluidic technology will have potential in the field of marine environmental monitoring.

[Experience of Sun's procedure for chronic type B dissection with aortic arch involvement]

Objective: To study the surgical treatment of chronic type B dissection with aortic arch involvement using Sun's procedure. Methods: Between February 2009 and December 2015, 29 patients [20 males, 9 females, with a mean age of (41±12) years, range 24-64 years] with type B dissection with aortic arch involvement underwent Sun's procedure. Sixteen patient had a history of hypertension. Marfan syndrome was observed in 9 cases, coronary artery disease in 3 cases, mitral regurgitation in 3 patients, cerebrovascular disease in one patient. Twenty-two patients suffered proximal aortic arch disease, 4 cases experienced history of aortic root procedure and 2 subjects had history of pregnancy. Four patients had aortic arch malformation. Results: One case suffered from massive cerebral infarction after surgery and died in another hospital. Concomitant procedures included mitral valve replacement in 3 cases, coronary artery bypass grafting in 3 patients, reconstruction of the right aberrant subclavian artery in one patient. Ventilator support exceeding 24 hours obseved in 2 patients. One of them recieved continuous renal replacement therapy and recovered before discharge. Spinal cord injury was obseved in one case, brain infarction in one patient and pericardial drainage in one case. Two patients required tracheotomy. During 12-94 (43±23) months' follow-up, thoracoabdominal aortic replacment was performed in 4 patients, thoracic endovascular aortic repair (TEVAR) in 2 subjects and repair of perivalvular leakage in one patient. Conclusions: Sun's procedure obtained satisfactory results in patients with chronic type B dissection with aortic arch involvement. Concomitant repair of proximal aortic arch lesions and distal type B dissection can be adopted using Sun's procedure.

[Treatment strategies of complex lesions in patients with acute Stanford type A dissection of important branches involvement]

Acute Stanford type A aortic dissection with important branches involved is more complex, could lead to organ malperfusion syndrome even organ failure. The understanding of pathological anatomy, classification, staging, and the pathophysiological change has increasingly mature, but not complete. In addition, the treatment strategy for complex lesions is diversified, some questions may not reach consensus. Fully understanding of the anatomical and pathophysiology is very important for surgeons to choose reasonable treatment strategy. As the rapid development of the basic research, imaging techniques and the concept of surgery procedures, the manage technique of Stanfrod type A dissection and branch vessels at the same time is getting seriously, the related issues also need further discussions.

[Expression and significance of EPCR in plasma and placenta of patients with early onset severe preeclampsia]

Objective: To investigate the expression of endothelial protein C receptor(EPCR)and its roles in plasma and placenta of patients with early onset severe preeclampsia. Methods: Sixty cases of severe preeclampsia women who delivered in Xuzhou Maternity and Child Health Care Hospital from March 2014 to February 2016, were recruited, which included 30 cases with early onset severe preeclampsia(early onset group, gestational week <34 weeks)and 30 patients with late onset severe preeclampsia(late onset group, gestational week ≥34 weeks). Thirty cases of healthy late pregnant women at the same period(gestational week ≥34 weeks)were selected as control group. Immunohistochemistry SP method was applied to detect the expression of in EPCR placenta. Reverse transcription(RT)- PCR was used to detect the expression of EPCR mRNA in placenta. ELISA method was used to detect the levels of soluble EPCR(sEPCR)level in plasma of the pregnant women of the three groups. Results: The expression of EPCR in placenta mainly distributed in the membrane and cytoplasm of placental syncytiotrophoblasts and vascular endothelial cells, a few in the cell nucleus. The expression of EPCR in early onset group(57%, 17/30)was significantly lower than that in late onset group(93%, 28/30; χ²=25.165, P=0.001). The expression of EPCR in late onset group had no significant difference from that in control group(97%, 29/30; χ²=0.540, P= 0.910). The expression of EPCR mRNA in placenta of early onset group(0.40±0.07)was significantly lower than that in late onset group(0.91±0.06; t=-30.044, P=0.001), while there was no statistical difference of the expression of EPCR mRNA between the late onset group and the control group(0.92±0.07; t=-0.631, P=0.538). Plasma sEPCR level in early onset group, late onset group and control group were(231 ± 11),(124±6)and(121±4)μg/L respectively, which is higher in early onset group than that in late onset group(t=48.080, P=0.001). There was no statistical difference of plasma sEPCR level between the late onset group and the control group(t=2.534, P=0.100). Conclusions: The pathogenesis of early onset and late onset severe preeclampsia may be different. Decreased expression of EPCR in placenta may be associated with the pathogenesis of early onset severe preeclampsia.

[An investigation for standardized diagnosis and treatment of idiopathic normal-pressure hydrocephalus]

OBJECTIVE

To investigate some important issues for diagnosis and treatment of idiopathic normal-pressure hydrocephalus (iNPH), such as standardized pre-operative assessment, initial pressure value of diverter pump, and pressure regulation during follow-up.

METHODS

Twenty six iNPH patients (21 males) who treated in Department of Neurosurgery of 2nd Affiliated Hospital of Zhejiang University School of Medicine from 2011 to 2015 were analyzed retrospectively. The average age was 60.5 year. The analysis focused on the treatment process of iNPH, initial pressure value of diverter pump, choice of diverter pump, and pressure regulation during follow-up.

RESULTS

As a result, 24 cases (92.3%) had a good prognosis based on their imaging and clinical manifestations. Based on the literature and their clinical experiences, this department established a diagnosis and treatment procedure of iNPH and a pressure regulation procedure for the follow-up of iNPH. Moreover, it is proposed that choosing an anti-gravity diverter pump and making an initial pressure value 20 mmH2O less than pre-surgical cerebrospinal pressure may be beneficial for the prognosis.

CONCLUSION

This standardized diagnosis and treatment procedure for iNPH is practical and effective.

[Application of evoked potentials monitoring in total thoracoabdominal aorta aneurysm repair]

OBJECTIVE

To evaluate the application value of evoked potentials (EP) monitoring in patients undergoing aorta-iliac bypass for total thoracoabdominal aorta aneurysm repair (tTAAAR).

METHODS

A prospective study, with a total of 31 patients undergoing tTAAAR and intraoperative EP monitoring from June 2014 to April 2015 was carried out. The results of intraoperative evoked potentials, clinical outcomes and follow-up data of patients were collected for further evaluation.

RESULTS

The EP wave disappeared [motor evoked potentials for (55.6±18.1) min, somatosensory evoked potentials for (50.3±18.7) min] after proximal descending aorta being clamped, and gradually recovered after the segment arteries of spine cord were reconstructed. The EP wave was restored to normal level at the end of operation in all the cases. The somatosensory evoked potentials remained unchanged in 2 cases (false negative). One case died after operation. No spinal cord injury occurred. The median follow-up after operation was 10 months (5-14 months). There was no delayed neurological deficit.

CONCLUSION

EP provided an on-line monitoring of the condition of spinal cord function, which become an intraoperative protocol to avoid the irreversible injury of spinal cord.

Low levels of free testosterone correlated with bone mineral densities of femoral necks in aged healthy Shanghainese men

The aim of the study was to investigate the influence of serum testosterone concentrations on bone mineral densities (BMDs) in healthy aged men in Shanghai area. Eighty-four participants, registered in the physical examination center of our hospital were included. Liquid chromatography tandem mass spectrometry (LC-MS/MS) was used to measure concentrations of total testosterone (TT) and free testosterone (FT) in serum. BMDs of the lumbar spine, femoral neck, the trochanter major, and Ward's triangle were determined with dual energy X-ray absorptiometry (DXA). The correlations of TT and FT with BMDs at the different skeleton sites were analyzed; stratified analyses by age were performed with 10-year range groups and the changing trends of TT and FT with increasing age were further investigated. In addition, we performed a stratified quartile TT and FT analysis of their correlations with BMDs of different bones in each group. The average age of the participants was 71.8 ± 9.6 years (50-90 years). In a stratified analysis by age, no significant TT changes with increasing age was found, but there was a significant decrease of FT in men older than 80 years (p<0.05). In a stratified FT quartile analysis, FT in the first quartile group correlated significantly with BMDs of the lumbar spine, femoral neck and Ward's triangle; however, there was only a significant correlation between FT and BMD of the femoral neck after adjustment for age and body mass index (BMI). FT blood serum concentrations decreased significantly in healthy men aged over 80 and positively correlated with BMDs of femoral necks.

Hybrid lasing in an ultra-long ring fiber laser

In this paper, we reported the realization of an ultra-long ring fiber laser (RFL) with hybrid emission related to both random lasing and cavity resonance. Compared with a linear random fiber laser (LRFL), the Rayleigh scattering (RS) inducting distributed feedback effect and the cavity inducting resonance effect exist simultaneously in the laser, which reduces the lasing threshold considerably and provides a hybrid way to form random lasing (RL). The laser output can be purely modeless RL when pump power is high enough. It is also discovered that the laser is insensitive to temperature variation and mechanical disturbance, this is unique and quite different from conventional RFLs which are environmentally unstable due to existence of the cavity modes.

Decreased CD27 on B lymphocytes in patients with primary hepatocellular carcinoma

OBJECTIVES

Hepatitis B virus (HBV) replicates in the liver and can lead to hepatocellular carcinoma (HCC). The B lymphocytes may provide a means for HBV to persist although the mechanism remains unknown. This study aimed to characterize B lymphocyte subset phenotypes and measure levels of B lymphocyte-related cytokines in HCC patients.

METHODS

The study population included 38 HCC patients and 30 healthy control subjects. Phenotyping of B lymphocytes was performed by flow cytometry. Serum cytokine levels were measured using a cytometric bead array immunoassay.

RESULTS

The ratio of naïve (CD29+CD27-) to memory (CD19+CD27+) B lymphocytes was significantly higher in HCC patients compared with healthy controls. The percentage of memory B lymphocytes decreased with the progression of HCC. Levels of interleukin (IL)-6 and IL-10 were significantly increased in HCC patients compared with healthy controls.

CONCLUSIONS

The depletion of memory B lymphocytes may contribute to unresponsiveness to HBV or to HCC. This humoral defect might be related to raised production of IL-6 and IL-10.

Synthesis of crystalline beta-FeSi2 under high-temperature and high-pressure

In this paper, we report the synthesis of crystalline beta-FeSi2 via the reaction of Si and Fe powders under high-temperature and high-pressure. X-ray diffraction and Raman scattering results confirm formation of the beta-FeSi2 phase. Scanning electron microscopy, high-resolution transmission electron microscopy, and selected-area electron diffraction patterns show that the beta-FeSi2 phase coexists with Si phase with small nanocrystal sizes. The formation of the beta-FeSi2 phase is a result of Si diffusion into Fe region. The obtained results suggest that the removal of Si phase can be reached through increasing Fe content and prolonging the duration of high-pressure thermal treatment.

Functional recovery after transplantation of neural stem cells modified by brain-derived neurotrophic factor in rats with cerebral ischaemia

Functional recovery after transplantation of brain-derived neurotrophic factor (BDNF)-modified neural stem cells (NSCs) was evaluated in a rat model of cerebral ischaemia damage induced by temporary middle cerebral artery occlusion (tMCAO). Western blotting and enzyme-linked immunosorbent assay demonstrated upregulated BDNF protein expression by rat embryonic NSCs transfected with the human BDNF gene (BDNF-NSCs). BDNF-NSCs stimulated neurite outgrowth in cocultured dorsal root ganglion neurons, suggesting that BDNF increased neurogenesis in vitro. In vivo, BDNF promoted recovery of tMCAO. Phosphate-buffered saline, untransformed NSCs or BDNF-NSCs were introduced into the penumbra zone of the right striatum of tMCAO rats and neurological function deficit was assessed for up to 12 weeks using the neurological severity score (NSS). The NSS was significantly lower in the BDNF-NSC transfected transplant group than in all the other groups from week 10. BDNF-NSCs recovered 1 week after transplantation expressed BDNF protein. Transplanted NSCs had differentiated into mature neurons 12 weeks after transplantation. Transgenic NSCs have potential as a therapeutic agent for brain ischaemia.

Large Low-Field Magnetoresistance in Nanocrystalline Magnetite Prepared by Sol−Gel Method

Nanocrystalline magnetite Fe3O4 samples with a grain size of about 40 nm have been synthesized by an optimized sol-gel method. The single phase of spinel magnetite was confirmed by both X-ray diffraction and transmission electron microscopy. It has been found that the magnetoresistance of the samples at low field (LFMR) is relatively large, and with the decrease of temperature its value at a field of 0.5 T changes dramatically from -2.5% at 300 K to -17.0% at 55 K. With the further decrease of temperature a sharp drop occurs for the magnitude of the magnetoresistance (MR), regarded as a spin (cluster) glass transition in the surface region of the grains that can be confirmed by the zero-field-cooled and field-cooled magnetization and ac susceptibility measurement. The mechanism of the magnetic and transport properties was discussed.

Electrochemical lithography: fabrication of nanoscale Si tips by porous anodization of Al/Si wafer

Porous anodization of Al/Si wafer in sulfuric acid results in the formation of Si nanotips on the surface of Si substrate with ultrahigh packing density.

Giant room-temperature magnetoresistance in polycrystalline Zn(0.41)Fe(2.59)O4 with alpha-Fe2O3 grain boundaries

A tunneling-type magnetoresistance (MR) as large as 158% is observed at T = 300 K in a polycrystalline Zn0.41Fe2.59O4 sample, in which the Zn0.41Fe2.59O4 grains are separated by insulating alpha-Fe2O3 boundaries. The huge room-temperature MR is attributed to the high spin polarization of Zn(0.41)Fe(2.59)O4 grains and antiferromagnetic correlations between magnetic domains on both sides of the insulating alpha-Fe2O3 boundary. The MR exhibits strong temperature dependence below 100 K and its magnitude is enhanced to reach 1280% at 4.2 K, which may arise from the Coulomb blockade effect.

Supracondylar extension fracture of the humerus in children. Manipulative reduction, immobilisation and fixation using a U-shaped plaster slab with the elbow in full extension

We present a method of manipulative reduction, immobilisation and fixation using a U-shaped plaster with the elbow in extension for extension-type supracondylar fractures of the humerus in children. When the elbow is in full extension, both the extensor and the flexor muscles are neutralised during manipulative reduction and the carrying angle can be easily assessed thus preventing cubitus varus, the most common complication. In order to evaluate the efficiency of this method, we compared the clinical results of the new method with those of conventional treatment. In a group of 95 children who sustained an extension-type supracondylar fracture of the humerus, 49 were treated by the new method and 46 by the conventional method, reduction and immobilisation in a plaster slab with the elbow in flexion. Reduction and immobilisation were easily achieved and reliably maintained by one manipulation for all the children treated by the new method. In 12 children treated by the conventional method, the initial reduction failed and in seven secondary displacement of the distal fragment occurred during the period of immobilisation in plaster. All required a second or third manipulation. Of the 46 children, 28 (60.9%) had developed cubitus varus at a mean follow-up of 4.6 years when treated by the conventional method. None of the children treated by the new method developed cubitus varus. The mean score, according to the Hospital for Special Surgery (HSS) elbow scoring system, was 91 points using the new method and 78 with the conventional method. The results were statistically significant with regard to the incidence of cubitus varus and the elbow score (p < 0.01) suggesting that the new method is reliable and gives a satisfactory outcome.

Nanostructured copper filaments in electrochemical deposition

In this Letter we report a novel self-organized copper electrodeposition in an ultrathin layer of CuSO4 electrolyte. The macroscopic fingering branches of the deposit consist of long copper filaments covered with periodic corrugated nanostructures. The mechanism of the nanostructure formation is explored and the origin of the significant descent of the branching rate in electrodeposition is discussed. We suggest that this growth phenomenon provides deeper insights into the role of diffusion and migration on pattern formation in electrodeposition.

[Cloning and expression of a synthetic gene encoding magainin-melittin hybrid peptide in Escherichia coli and studies on its antibacterial activity]

A hybrid peptide gene was designed and synthesized. Its encoding peptide is constructed from residues 3-14 of magainin and residues 1-13 of melittin. The MA-E gene was cloned into plasmids pUC18 and pBV220. By DNA sequencing, the whole sequences of this gene is confirmed to be correct. The recombinant plasmid pBMA-E was expressed in E. coli DH5 alpha. A gene product band can be seen with Tricine-SDS-PAGE. The MA-E hybrid peptide was purified by immobilized metal affinity chromatography. Bioactivity assay was carried out in liquid turbidity method. The bactericide value to E. coli K12D31 is 0.182.

[The function of T7 promoter as cis-acting elements for polymerase II in eukaryotic cell]

Using the chlorampheniol acetyltransterase gene as reporter, the function of phage T7 promoter in mammalian cells was studied by inhibition of transcription with alpha-amanitin. The experiment proved that the reporter under T7 promoter was transcribed by RNA polymerase II. Competitive electropho retic mobility shift assay (CEMSA) with TATA box, CAAT box, GC box and octamer showed that the TATA box was competitive molecular for synthetic T7 promoter. It is possible that T7 promoter is bound with TF II D transcription factor. The TATA box and octamer were inserted into Pvu II site upstream from the T7 promoter of pT7CAT. Two recombinant plasmids, pT7TATACAT and pT7OCTCAT, were constructed and transfected into CHO cells. CAT-activity test showed that T7 promoter strength was increased by octamer factor, not by TATA box. These results suggested that T7 promoter functions as cis-acting elements of RNA polymerase II transcriptional system in eucaryotic cells.

[The sequence analysis of the 3' end of intron 15 from human LDL receptor gene and its application in the study of gene diagnosis for familial hypercholesterolaemia]

To understand intron 15 of human LDL receptor gene, the DNA fragments from exon 15 to exon 16 and the 3' end of intron 15 were amplified with long chain PCR and anchored PCR. The 3' end of intron 15 was sequenced with Dynalbeads-Streptavidin Solid Phase technique. The sequence analysis showed that the 3' end of intron 15 contained the 3' splicing site and the branch site at 31 nucleotides upstream of the 3' end. Besides the authentic branch site, it is possible that the 3' end of intron 15 contains a cryptic site (GCCTCAC) at 20 nucleotides upstream of the 3' end. The sequences suggest that the PvuII polymorphism at Intron 15 is caused by the T-C substitution. According to the sequences of the 3' end, the new PCR-RFLP protocol for detection of PvuII polymorphism at intron 15 was developed. Using this protocol a representative familial hypercholesterolaemia family was identified with linkage analysis of PvuII polymorphism at intron 15.

Stimulated anti-echo selection in spatially localized NMR spectroscopy

Spectral localization using the stimulated-echo acquisition mode (STEAM) is one of the most popular methods in volume-localized in vivo NMR spectroscopy. The localized volume signal is generated via stimulated echoes from spins excited by three 90 degrees RF pulses, and the conventional STEAM sequence detects the stimulated-echo signal. From an analysis of the STEAM pulse sequence using the coherence transfer pathway formalism, stimulated anti-echoes are also formed by the same pulse sequence, which constitute the other half of the localized signal in the STEAM experiment. A new scheme of pulsed field gradients for the selection of stimulated anti-echoes was proposed, and localized spectroscopy in the stimulated anti-echo selection mode was achieved on a phantom and from in vivo rat brain.

Studies on atrophic change of soleus muscle and its countermeasures in suspended rat

In the environment of microgravity, the disused atrophy of skeletal muscle, especially leg's muscle, would occur. The three purposes of this study were: 1. To observe the dynamic changes of disused atrophy of skeletal muscle under simulated weightlessness; 2. To approach the mechanism of disused atrophy of muscle; 3. To approach the countermeasures for reducing the degree of atrophy of muscle.

[Measurement of scapho-lunate distance of normal wrist]

The scapho-lunate distance was measured on posteroanterior radiographs of 200 normal wrists of 100 healthy persons. In light of the measuring method by Dr. Cautilli and Wehbe, reference points and lines were marked and drawn on radiograms taken with standard technic. The scapho-lunate distance measured a mean of 3.14 mm +/- SD 0.73 (ranging from 1.5 to 5.0 mm), the variables of age, sex or handedness did not result in significant differences in measurement (P > 0.05).

Semiautomated methods for cancellous bone histomorphometry using a general-purpose video image analysis system

Semiautomated methods are used to measure elongated, curved and complex branching profiles and isolated perimeter segments in monochrome video images with a general-purpose analysis system. These methods are used to make the major primary measurements of bone histomorphometry. Accuracy and reproducibility of the image acquisition, processing and measurement system is documented by measuring a semicircular standard of known dimensions. Semiautomated applications of the Ar/Le method for measuring areas and perimeters, and calculating lengths and widths of osteoid seams, lengths of mineralization labels and mineral apposition rate, wall width, indirect measurements of eroded, osteoclastic and osteoblastic perimeters without tracing, and measurement of mineralized or total cancellous bone area and perimeter gave values comparable to measurements of the same parameters by tracing or grid counting techniques with equal or better reproducibility and much greater efficiency. Intraindividual variation in measuring multiple bone biopsies methods. Major sources of variability for semi-automated methods were image magnification and selection of profile edges by thresholding, and sources of variability for manual methods are image magnification, numbers of orthogonal intercepts, tracing speed and accuracy of the algorithm used to measure traced pixels. Semiautomated methods are accurate, reproducible and rapid methods suitable for bone histomorphometry.

[Effect of parathyroidectomy (PTX) on aluminum (Al) induced bone disease]

Al-treated or untreated decalcified sections of bone matrix were implanted subcutaneously into the abdominal wall of parathyroidectomized (PTX) or control rats for 21 or 28 days. The bone remodeling and Al, Ca content in the implants were measured by using histomorphometry and atomic absorption spectrum method. The results showed that bone area, osteoclast number, osteoblast number and bone mineralization rate of Al-treated or untreated bone in PTX rats and of Al-treated bone in control rats were significantly lower than those of untreated bone in control rats (P < 0.05). There was no marked difference between these parameters of Al-treated bone in control rats and untreated bone in PTX rats (P > 0.05), and these of Al-treated bone in PTX rats were the lowest (P > 0.05- < 0.05). Ca contents were consistent with the histological parameters. Bone Al removing rate between PTX and control rats was not markedly different. In conclusion, both PTX and Al impair bone formation and mineralization, bone biopsy and removal of Al from bone is necessary before PTX treatment in uremic patients with secondary hyperparathyroidism.

Impaired recovery of strength in older patients after major abdominal surgery

OBJECTIVE

This study compared changes in muscle strength after major elective abdominal surgery in young and old patients, and related these changes to body composition and nitrogen balance.

SUMMARY BACKGROUND DATA

The breakdown of muscle protein, erosion of lean tissue, and negative nitrogen balance are characteristic metabolic responses to surgical illness. With a substantial loss of muscle mass typical of advancing age, the authors postulated that older patients would be weaker during acute surgical illness and less able to maintain muscle function and meet metabolic demands.

METHODS

Active, community-dwelling individuals undergoing major abdominal procedures who were 70 years of age or older or 50 years of age or younger were studied. Total body water (TBW) was determined preoperatively by deuterium oxide dilution. Maximal voluntary handgrip, respiratory muscle strength, and visual analog pain scores were measured preoperatively and on postoperative days 2, 4, and 6. All urine was collected postoperatively for 7 days for determination of total nitrogen, creatinine, and cortisol.

RESULTS

The young (age, 36 +/- 9 years [mean +/- standard deviation]; n = 20) and old groups (age, 77 +/- 5 years; n = 20) were similar regarding weight, sex distribution, nutritional status, surgical procedures and anesthesia, and postoperative urine cortisol values. Age group, time after operation, and interaction effects were significant for each strength variable (all p < 0.005 by analysis of variance). Older patients had lower preoperative strength (29% to 41%) and mean 24-hour urine creatinine (27%). Postoperative strength was decreased most markedly on postoperative day 2, with similar proportional changes in the two age groups but lower absolute levels in the older patients. The rate of recovery of strength was substantially less rapid and complete in older patients. Older patients had less postoperative pain and received much less parenteral narcotic than younger patients. Postoperative urine nitrogen was similar in each group. Recovery of strength was not related to malignancy, preoperative strength, muscle mass (urine creatinine), lean body mass (TBW), sex, malignancy, pain, or narcotic administration.

CONCLUSIONS

Older patients are weaker preoperatively than younger patients; their strength falls to lower levels after surgery and their postoperative recovery of strength is impaired. The lesser preoperative strength of older patients is due in large part but not totally to diminished muscle mass. Their impaired postoperative recovery appears to be related to more acute factors, such as muscle energetics or substrate availability.

[Histological classification of uremic bone disease and clinical significance of bone biopsy]

Bone biopsy was performed in 429 cases of uremic bone disease and they were classified histologically into 3 groups--high turnover 129 (30%), low turnover 102 (24%) and mixed type 198 (46%) cases. The histological features of the high turnover type were increased corrected mineralization rate (CMR) and osteoclast member and decreased mineralization lay time (MLT), while those of the low turnover type were on the contrary. In the mixed there were decrease of CMR and increase of MLT and osteoclast number. Bone aluminum positive rate was determined; it was 75% and 80% respectively in the low turnover and mixed type and 29% in high turnover. Biochemical study showed that significantly higher levels of serum PTH and alkaline phosphate in the high turnover type and low levels of serum 1,25(OH)2D3 and 25(OH)D3 in the low turnover. These results suggested that high turnover uremic bone disease is caused by secondary hyperthyroidism and low turnover mainly related to aluminum toxicity or other causes such as vitamin D deficiency.

Cloning and structural-functional studies for 7.5k promoter of Tiantan strain of vaccinia virus

The 7.5k promoter of vaccinia virus Tiantan strain has been cloned by DNA polymerase chain reaction (PCR) method. Results of DNA sequencing analysis showed that in comparison with P7.5k of WR strain, three site mutations and 7 bp of natural deletion existed in the 155 bp fragment of P7.5k of Tiantan strain; four of 7 base pairs deleted were in the late transcriptional initiation region. Although the total mutation rate was high to 6.45%, these two 7.5k promoters of Tiantan strain & WR strain were all early-late promoters and not obviously different in their activities and functional phases. The results above confirmed further that it is a mechanism to keep their genetic stability that some genes of vaccinia virus have multiple transcriptional initiation sites and produce many mRNA with heterologous 5' ends.

[Bone histology and clinical diagnostic criteria in aluminum-induced bone disease]

Bone remodeling and aluminum (Al) staining were carried out in 429 bone biopsies from patients with uremic bone disease, 273 cases were Al positive (64%). In high-turnover, low-turnover and mixed type of renal osteodystrophy the Al-positive rate was 29%, 75% and 80%, and Al deposition on bone surfaces was 44 +/- 33%, 80 +/- 30% and 62 +/- 35% respectively. Thus the low-turnover and mixed type have a higher Al-positive rate and more Al deposition than the high-turnover type. Animal experiments using decalcified bone matrix implants showed that Al inhibited all bone remodeling processes except cartilage formation. These and other data indicate that Al induces low-turnover bone disease, i.e., osteomalacia or aplastic bone disease. Osteomalacia in our series showed increased osteoid area and mineralization lag time, and decreased calcified bone area, bone mineralization rate and cells number. Aplastic bone disease was similar with that but had reduced osteoid and a normal ratio of steroid to calcified bone. The relationship of these studies to clinical diagnostic criteria of Al-induced bone disease is discussed.

[Calculation of carpal-high index of normal hand]

The carpal-high index was calculated from figures measured on X-ray films of 200 normal hands of 100 healthy persons. In light of the measuring methods by Dr. Youm et al and Dr. Stahelin et al., reference points and lines were marked and drawn on radiograms taken with standard technic. The carpal-high index was 1.0. Its standard deviation was smaller than that of carpal-high ratio. The carpal-high index can be used as a scale to investigate progression or regression of unilateral carpal disease before or under treatment.

Effect of aluminum on bone matrix inductive properties

The effect of aluminum on the bone inductive properties of implanted bone matrix was studied in rats. After decalcification femur sections were placed in either 0.1 or 0.01 M AlCl3 or a solution of similar pH without Al for 24 hours. Following 28 days of implantation in subcutaneous pouches the aluminum content was 3232 +/- 1020 and 51 +/- 6 mg/kg in the matrix pretreated with 0.1 and 0.01 M AlCl3. At the same time period following implantation the matrix calcium content was 794 +/- 539 and 3038 +/- 692 mmol/kg in the 0.1 and 0.01 M AlCl3 pretreated groups versus 4252 +/- 579 mmol/kg in the control group (P less than 0.01). In the control group bone histology showed extensive osteoblastic and osteoclastic remodeling, tetracycline labeling and bone formation. In contrast all of these histological features were virtually absent in aluminum treated matrix. Aluminum-induced resistance of bone matrix to collagenase degradation and restoration of bone inductive properties with chelation suggests that aluminum forms intermolecular cross links between collagen fibrils. Aluminum-induced cross links of collagen fibrils and/or its effects on bone inductive proteins present in bone matrix could explain the mechanism by which aluminum induces osteomalacia.

[Experimental study of the mechanism of aluminum-induced bone disease]

The mechanism of aluminum-induced bone disease was studied by experiments in vitro and in rats. After decalcification femur sections were treated with 0.1 M AlCl3 and implanted with control bone matrices into weanling male rats. After 4 or 8 weeks of implantation the tissue values of calcium(Ca), phosphorus(P) and aluminum(Al) were measured. The results showed that both Ca and P values in Al-treated bones were obviously lower than those of the controls (P less than 0.01), Al level in these bones remained considerably high. Histological examination indicated that aluminum deposited diffusely in Al-treated bones, the bone formation rate and mineralization rate markedly decreased, osteoclastic and osteoblastic activities were also inhibited. In collagenase incubation test the bone matrices pretreated with different concentrations of AlCl3 showed different degrees of resistance to digestion of collagenase. It is considered that aluminum forms tight complexes with bone collagen causing cross linkage and destroying the inductive effect in bone matrix, thus leading to aluminum-induced bone disease. Our study also suggests that the usage of chelating agents can remove aluminum from matrix and recover its abilities of bone formation and mineralization.