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Service technology is a component-oriented SOAP based interoperable technology widely adopted in Enterprise Application Integration (EAI) and Business to Business (B2B). The decoupling is one of the most important features of service components that make Web services successful in the future. Software measurement plays an important role in today's software development. Decoupling metrics can be used to measure and evaluate the decoupling attributes of a distributed service oriented software architecture that has very significant impacts on the understandability, maintainability, reliability, testability, and reusability of software components. The decoupling metrics can also be used as a criterion for selection of existing service components for compositions. Many measurement metrics for decoupling have been proposed, however most measures are not specific for service component decoupling. This paper provides a practical guide for evaluating decoupling between service-oriented components in the service composition such as Business Process Execution Language (BEPL). A lower decoupled distributed software application will be much easy to understand, update, and expand in the future Coupling was originally defined as the measure of the strength of association established by a connection from one module to another. Most of the existing techniques and measuring coupling metrics are classified by procedural programming and object-oriented programming. In this paper we propose a decoupling metrics based on the black-box parameters of service stateness (stateless/stateful), interaction (one-way, twoway), service interface required(, service interface provided(supporting/supported interface), invocation modes(sync/async), self-containment(stand-alone/indirect dependent), implicit invocation (blocking/non-blocking), and binding modes(static/dynamic).

Introduction The aim of this study was to develop a rat model of chronic irreversible rejection, which is a major causes of late graft loss and retransplantation after orthotopic liver allotransplantation. Methods Allogeneic liver transplantation was performed in a rat combination of Dark Agouti (DA) to Brown Norway (BN). Group A was left without treatment, group B received cyclosporine’ (CsA; 1 mg/kg/d) and group C, CsA (4 mg/kg/d). Animals were followed for 6 months. Liver tissue was harvested to construct a time course of histological changes after liver transplantation using histopathological and morphometric techniques. We compared the total histological score of rejection activity index and survival rates. Results In untreated animals, irreversible acute rejection developed, all animals died within 15 days. In the low-dose CsA group, all animals that survived more than 30 days developed moderate to severe manifestations of chronic liver rejection, with graft infiltration, ductular damage or proliferation, obliterative arteriopathy, and liver fibrosis. No apparent histological alterations were observed in group C. Survival analysis showed significant differences between the three groups. Conclusions In the rat strain combination of DA → BN with low-dose immunosuppression, early mild inflammation was followed by the development of chronic rejection.

Instantaneous frequency (IF) is very important in signal communications and methods, such as Hilbert transform and more recently wavelet ridges, have been developed to extract them. The importance of IF for 2D images has often been ignored. For example, in moire interferometry, IF can directly provide strain contours, which usually is the desired parameter in experimental mechanics. In this paper, the method of wavelet ridges is first extended from a 1D signal to 2D images with carrier fringes. In cases where the carrier fringes is not available, the phase shift approach is proposed, to extract the instantaneous frequency (IF) using wavelet ridges. Both methodologies are introduced and applied to real fringe patterns.

With the authors' diaphragm pump and pulsatile as well as nonpulastile impeller pumps, and the clinically used Sarns Roller, both left ventricular assist and biventricular assist experiments were performed on mini pigs and calves. The results demonstrate that the pulsatile impeller pump is the best assist pump for recovering the heart function, because it maintains the pulsatility of aortic pressure by heart failure and thus increases the circulation volume, and it enlarges the diastolic pressure so as to increase the perfusion in coronary artery because it has no backflow.

The authors' impeller pump as a left ventricular or biventricular assist device was evaluated in animal experiments and clinical trial. Three calves survived over 6 weeks in left ventricular assist experiments and neither blood damage nor organ dysfunction of the animals was detected. In clinical trial, the pump supported both the greater and lesser circulation of a 6-year-old child with trilogy of Fallot and low output syndrome after open heart surgery. In 43 hours the pump worked properly. The pump weighing 240 g can perform either in pulsatile or in nonpulsatile mode. In pulsatile pumping, the impeller changes its rotating speed periodically by introducing a square wave form voltage into the motor coil.

The line-shaped filaments Sp-Z(L) were isolated and cultured from Spirulina platensis Sp-Z. The growth rate of Sp-Z(L) was only 64% as much as that of Sp-Z when the light intensity was 4000 Lux. The contents (x 10(-3) g/g dry weight) of chlorophylls, carotenoids and phycobilins of Sp-Z(L) and Sp-Z were 20.6, 0.343, 5.00 and 24.1 0.297, 4.46, respectively. Moreover, as to the absorption spectra of the three photopigments of Sp-Z(L), red shifts were observed. Therefore, after the spiral Sp-Z breeded or changed into Sp-Z(L), The contents of carotenoids and phycobilins raised 23% and 12%, respectively, but the contents of chlorophylls dropped 14.5%, and the growth rate dropped 36% too. The results probably showed that the decrease of chlorophylls was one of the main reasons that caused the remarkable decrease of the growth rate of Sp-Z(L).

This paper presents an approximation method for numerically solving general Markov modulated fluid models which are widely used in modelling communications and computer systems. We show how the superposition of a group of heterogeneous sources (normally modeled by a multidimensional Markov process) can be approximated by a one-dimensional Markov process, which is then used as the modulating process of the buffer content process. The method effectively reduces the computation that is usually required to find exact (or asymptotic) solutions of fluid models.

Objective. To test the validity of an animal model in selecting anti-motion sickness drugs, and compare the effects of two drugs. Method. Anti-motion sickness effects of two drugs (Cyclizine and Scopolamin-d-amphetamin compound) were observed in rats with motion sickness (MS) induced by rotatory stimulation and the amount of Kaolin ate by rats was taken as an evaluation criterion. Result. The consumption of Kaolin by the rats decreased significantly after administration of both drugs, and the effect of Scopolamin-d-amphetamin compound was better than those of Cyclizine under the same condition. Conclusion. It suggests that the rat model of motion sickness is practical and useful in studying anti-motion sickness drugs.

To observe pharmacokinetic changes under simulated weightlessness in relevant to body flood flow changes.Gentamicin was selected as probe drug in the present study, and rabbits exposed to Head-Down Tilt (HDT, -20 degrees) immobilization were selected as simulated weightlessness animal model. Seven rabbits were treated inf. with 3 mg/kg of gentamicin sulfate pre-HDT and 7 d after HDT. Gentamicin blood samples within 4 h after administration were analyzed by TDxFLx.The distribution of gentamicin postponed significantly: a significant decrease in alpha from (0.1838 +/- 0.1076) min-1 before HDT to (0.0591 +/- 0.0334) min-1 after HDT; a significant increase in t1/2 alpha from (5.30 +/- 3.55) min to (15.04 +/- 7.49) min; a significant decrease in k12 from (0.1025 +/- 0.0721) min-1 to (0.0181 +/- 0.0161) min-1, a increase trend in V(C) and V(D). After HDT, CL(S) of gentamicin increased from (2.2 +/- 0.5) ml min-1 kg-1 to (2.7 +/- 0.3) ml min-1 kg-1.Simulated weightlessness might induce pharmacokinetic changes.

In this paper, several methods of output estimation of artificial heart are introduced briefly, and the authors put forward a method for the application of neural network to the output estimation of an impeller artificial heart. According to the laboratory results, the application of neural network can solve the problem successfully.

To assess retrospectively the clinical characteristics and cell immune function of infections caused by Flavimonas oryzihabitans (F. oryzihabitans).We indentified 11 cases of F. oryzihabitans positive cultures from all microbial cultures collected in our hospital from November 1994 to December 1998. Relevant clinical information was collected, including demographic data, underlying disease, and clinical manifestations of the F. oryzihabitans infections. Minimal inhibitory concentrations (MICs) of 15 antimicrobial agents against the 11 F. oryzihabitans isolates were determined. Cell immune function tests were determined by flow cytometry including T lymphocyte subsets (CD3, CD4, CD8 and ratio CD4/CD8) and NK cells (CD16 + 56) from peripheral blood.Six of these patients with infections caused by F. oryzihabitans were male, 5 were female and the mean age was 47.64 years (range, 5 to 69 years). All but 1 patients had severe underlying diseases. 9 (81.8%) of these patients developed infection while hospitalization and 2 (18.2%) before hospitalization (Cases 2 and 5). 8 (72.7%) of these patients manifested primary F. oryzihabitans bacteremia and one each (9.1%) had pleurisy, soft tissue infection and peritonitis. All these isolates were susceptible to amikacin, gentamicin and ciprofloxacin, but resistance to cefazolin, nitrofurantoin, penicillin and piperacillin. CD3, CD4, CD4/CD8 and CD16 + 56 value (mean +/- s) of these patients were significantly lower than normal values (P0.01). The mean time of body temperature fellor = 37 degrees C after antibiotic treatment in these patients was 3.5 days (range, 1 to 6 days). All clinical symptom caused F. oryzihabitans after antibiotic treatment disappeared and all patients recovered.Infections caused by F. oryzihabitans was very few clinically, and relative to underlying diseases and the presence of foreign material. Immune function abnormality was among mostly factor for the F. oryzihabitans infections.

Objective. To observe the improved effect of syndromes of blood stasis by taking Chinese medicine during bed-rest simulated weightlessness. Method. Ten subjects were randomly divided into two groups: Chinese medicine group and control group. Both of them were exposed to HDBR -6 degrees for a week. The Chinese medicine group took Chinese medicine during the bed rest, and the control group took sugar water. Result. Syndromes of blood stasis of Chinese medicine group had a significant relief. And some physiological parameters, such as blood pressure, pulse graph, and amount of urine, maintained the level of pre-bed rest. While the control group was more severe than the Chinese medicine group in syndromes of blood stasis. Conclusion. Chinese medicine can be a measure in preventing the effect of weightlessness.

Objective. To observe the counteracting effect of a Chinese herb-compound on "insufficiency of spleen qi" induced by simulated weightlessness. Methods. Animal and human experiment were carried out to the Chinese herb-compound (Dangshen, Baizhu, Fuling etc). Result. This compound protected the tail suspended rats from atrophy of spleen, thymus, soleus and gastrocnemius muscles, prevented excessive decrease of body weight effectively; at the same time it relieved the symptoms of the subjects greatly. Conclusion. It demonstrated that the compound decreased the "insufficiency of spleen qi" of both animals and human subjects.

As is well known, a pulsatile flow is important in assisted-circulation but it is difficult to produce a pulsatile flow with rotary pump, because excessive hemolysis will be generated. The authors have found that the turbulent shear is the main factor for red cell damage and therefore the key point of pulsatile rotary pumps is to reduce the turbulence by producing a pulsatile flow. In the authors' pulsatile axial pump, the pulsatile flow is obtained by axial reciprocation of constant rotating impeller; the rotation and reciprocation of the impeller are driven separately by a DC motor and a pneumatic device. Though a physiological pulsatile flow could be achieved and turbulence would not increase remarkably because the impeller rotates constantly, a second driver except a DC motor is nevertheless necessary, thus the system will become complicated. In the authors' pulsatile radial pump, a pulsatile flow is achieved by changing the rotating speed of the impeller periodically. Turbulence is minimized by a special design of twisted vanes which enable the blood flow to change its direction rather than its dimension during periodic change of rotating speed. Hemolysis tests demonstrated that the index of hemolysis(IH) of the author's pulsatile radial pump is 0.020, with is slightly more than that of the author's nonpulsatile radial pump(IH = 0.015). Animal experiments indicated that the pulsatile radial pump can assist the circulation of calves for several months without harm to blood elements and organ functions of the recipients.

To determine the heterogeneity of viral quasispecies and its clinical significance in patients with hepatitis C.Quasispecies in the sera from 76 patients infected with hepatitis C virus were detected using single stranded conformational polymorphism (SSCP) analysis of the HCV E2 hypervariable region 1 (HVR1).HVR1 was amplified in 72 (94.7%) of the 76 patients. The average number of SSCP bands was 5.8, with a range from 2 to 11. The numbers of quasispecies in acute hepatitis, chronic hepatitis and liver cirrhosis and/or primary hepatocellular carcinoma were 3.1 +/- 1.2, 6.0 +/- 2.3 and 8.4 +/- 4.1, respectively. There was a statistically significant difference among them (P0.01). Patients with infection acquired by blood transfusion and i.v. drug use had greater number of quasispecies than those acquired by other transmission pathway (sporadic) (P0.05). Patients with genotype 1 a and 1 b infection had increased quasispecies compared with those infected with HCV type 2 and 3(P0.05). Increased quasispecies heterogeneity was significantly correlated with serum HCV RNA levels (P0.01).SSCP is a simple, rapid and reliable method for the analysis of HCV viral quasispecies heterogeneity. Quasispecies heterogeneity plays an important role in HCV persistent infection and in the progress of hepatitis C. The duration of HCV infection, HCV genotype and HCV viremia are important determinants for the evolution of HCV quasispecies heterogeneity.

The author's implantable pulsatile impeller pump can assist the circulation of the calves for several months. The termination of the experiments was related to wear of the mechanical bearing, which resulted in vibration of the rotor and pump failure. It seemed as if the experiments could have lasted indefinitely if the bearing had not failed. To solve the problem of bearing wear, a specially devised rolling bearing was investigated and applied to the impeller pump. Its service life is more than 10 years due to the wear-proof roller made of ultra-highmolecular weight polythene. This newly devised impeller heart promises to have long-term and permanent applications. Compared with the magnetic bearing, the rolling bearing has the advantages of simpler construction and control, no consumption of energy, and better reliability.

Determination of chloramphenicol in the ear drops by first derivative spectrometry was studied. The detecting wavelength was 303.0 nm. The linear range was 0-65.2 micrograms.ml-1 (r = 0.9999). The average recovery was 99.84%, RSD = 0.37% (n = 8). The method is simple and accurate.

254 patients with cervical cancer were treated by radiotherapy from Jan 1979 to Dec 1984. All the patients were followed up at least for more than 3 years, of them 180 for over 5 years. According to various symptoms, picture of the tongue and pulse condition, the disease was classified into 4 types, namely: 1) deficiency of liver-yin and kidney-yin, 2) deficiency of splenic qi, 3) internal retention of damp-heat, and 4) stagnation of qi and blood or stagnation of liver qi. The survival rate of the various types was quite different. The patients of type 4 had the worst prognosis. The prognosis of patients with type 1 was significantly better than that of patients with type 4. The difference was of statistical significance (P less than 0.01).

Three PCR methods based on the GB virus-C/hepatitis G virus (GBV-C/HGV) 5'UTR and NS3 genomic region were used for the detection of GBV-C/HGV RNA in serum of 62 patients with chronic hepatitis C virus (HCV) infection. Ten of 62 (16%) patients were found to have GBV-C/HGV RNA, which was confirmed by sequence analysis of the 5'UTR PCR amplicon. All methods appear to be specific, but methods based on the 5'UTR appear to be more sensitive.

In this paper, we explore the potential of applying sojourn-time analysis in QoS metrics specification and in CAC algorithm design for ATM networks. We propose using the probability a link overflow occurs during a connection’s life as a measure of its QoS. Such sojourn-time based QoS metrics have big impacts on many network traffic management components, eg., CAC and routing. A CAC policy is accordingly designed which guarantees the so specified QoS for the entire life of each connection in the system. For a basic model, simple formulas are obtained for the estimate of the probability that a link overflow occurs within certain time interval. The analytical approach used and presented in the paper is a set of general results for estimating the probability distribution function and the mean of the sojourn-time of a Markov process being in a subset of its state space, which may correspond to a system’s underload status.

A method for the simultaneous determination of eight kinds of conjunct bile acids in human bile was developed by HPLC. They were separated on a YWG-C18 (3 microns) column at 30 degrees C, with methanol/water (65/35, V/V, pH3.0) as mobile phase, and detection wavelength at UV 210 nm. The linear ranges were 50-1,000 microns.ml-1, the recoveries were 91.2%-108.6%. The biles of 30 cases with cholelithiasis cholecystolithiasis and 20 cases without gallstone were detected by HPLC. The results showed that the constitution of bile acids was different between patients with cholelithiasis cholecystolithiasis and patients without gallstone.

The purpose of this study was to evaluate the effect of Nd:YAG laser irradiation on the phase velocity of surface acoustic waves (SAWs) of human enamel. A pulsed Nd:YAG laser at 1064 nm wavelength was used to irradiate the human enamel from extracted human premolars. The output power and repetition rate were 250 mJ and 5 Hz, respectively. The SAW phase velocities before and after laser irradiation were determined using a laser photoacoustic method. The laser-treated enamel surface exhibited a higher velocity value for frequencies higher than 3 MHz. The result of this study suggests that there is an important correlation between the elastic properties of human enamel and the pulsed Nd:YAG laser fluence, which increases the SAW phase velocity, and this may help shed some light on the mechanism of laser treatment in dental research.

To determine the clinical significance of viral quasispecies heterogeneity, 59 patients with chronic hepatitis C were studied using singlestranded conformational polymorphism (SSCP) analysis of the HCV E2 hypervariable region 1 (HVR1); of these, 48 were subsequently treated with interferon-alpha. The SSCP method was validated using clones of known nucleotide sequence. HVR1 was amplified in 54 of 59 (92%) patients. The median number of SSCP bands per sample was 6 (range: 2-12). Increased quasispecies heterogeneity correlated with the estimated duration of HCV infection (P0.05), parenteral-acquired HCV infection (vs. sporadic, P0.05), serum HCV RNA levels (P0.05), and HCV genotype 1 infection (P0.05), but not with age, serum AST, ALT, or Knodell score. Patients who had complete and sustained response to interferon-alpha (n = 11) had lower pre-treatment quasispecies heterogeneity compared to patients who had complete response with relapse (n = 18, P0.05) or no complete response (n = 16, P0.01). However, multivariate analysis revealed that HCV viremia was a stronger predictor of response to interferon-alpha. These findings indicate that the estimated duration of HCV carriage, serum HCV RNA levels, and HCV type 1 are important determinants for the evolution of HCV quasispecies heterogeneity; and that increased HCV quasispecies heterogeneity is another marker associated with a poor subsequent response to interferon-alpha.

When traffic sources are statistically multiplexed over a common link, the sum of the peak rates of the sources exceeds the throughput of the link. The excess may be stored in a buffer, but when this overflows, information is lost. When a source is bursty, the peak rate is attained only for very short periods of time, whereas between bursts the source is idle. Because the sources are independent, the chance that many bursts arrive simultaneously is small, but these rare events do occur and the mean time until overload is a key design parameter. Here we model the multiplexor as a multidimensional Markov process with a set of forbidden states that represent the exceedance of the link capacity. We use the theory of induced Dirichlet forms to estimate the Laplace transform of the hitting time of this forbidden set. We obtain an upper bound on the probability that the link capacity is exceeded during a fixed time interval along with a lower bound for the mean time until the link capacity is exceeded. This provides the network designer with a degree of assurance about the probability and frequency of overloads.

We have investigated the effect of ginseng on antiperoxidation in myocardium and erythrocytes of streptozocin-induced diabetic rats. In the group of ginseng administration (ginseng solution 0.2g/200g/day, lasting 15-16 days), there was a significant decrease in the level of fasting blood-glucose and lipid peroxide (LPO) in myocardium and erythrocytes, in comparing with that of model group, P0.05. The activity of superoxide dismutase (SOD) in myocardium and erythrocytes in group of ginseng administration was increased, P0.05, compared with that of model group and vitamin E treatment group. The mechanisms of antiperoxidation effect of ginseng might include the following: 1) By lowering the level of fasting blood-glucose, decreasing the rate of monosaccharide auto-oxidation and partially protecting the production of free radicals; 2) Elevating the activity of enzymatic free radicals scavenger in cells, such as SOD; 3) directly eliminating the superfluous free radicals.

In order to carry out quantitative epidemiological survey of animal schistosomiasis, a sensitive egg-counting method was studied both in the laboratory and in the field. Fecal material was filtered by a copper gauze (60 meshes/inch) into a nylon-tissue bag with 2 layers, 150 and 260 meshes/inch respectively. Thin smears were made from the residue in the bag. The mean recovery rate of mature schistosome eggs by previously adding 100 eggs to 5g of feces from noninfected cattle was 67.5%, ranging from 53 to 81%. To compare the egg-concentration thin smear method mentioned above, with egg-concentration thick smear method after hyalinization, various numbers of eggs, namely, 25, 50 and 100, were added to 5g of feces. The mean recovery rates of fecal eggs were 57.6%, 57.6% and 69.1% respectively, for the thin smear method and 3.2%, 13.8% and 19.5% for the thick smear method. The coefficients of variability in the former were from 12.9% to 17.4% and in the latter, from 30.7% to 98.8%. The total number of schistosome eggs per 5g of feces found in 34 egg-positive cattle in the field were 434 and 178 by the thin smear method and the thick smear method, respectively. A correlation analysis performed on the numbers of detected eggs in a total volume of fecal sediment and from half a volume of fecal sediment multiplied by two, showed a correlation coefficient of 0.98 (P less than 0.01), indicating that half a volume of fecal sediment may be used instead of a whole volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Experiments were carried out on mice and the subjects irradiated for cancer therapy to evaluate the protective efficacy of a Chinese medicinal herb-compound (CMHC). The lethality and the degree of leucopenia caused by radiation in mice medicated with CMHC were significantly less in comparison with control mice (p less than 0.01 and p less than 0.001, respectively). CMHC significantly improved the WBC and the thrombocytes in irradiated workers (p less than 0.01 and p less than 0.001, respectively). The WBC count of 40 patients under radiotherapy while treated with CMHC recovered from 3450 +/- 77/c.mm to 5425 +/- 264/c.mm (p less than 0.001); whereas, in the control group, without any medication, the WBC count dropped significantly (p less than 0.001). Our results revealed the applicabilities of CMHC in protection against radiation damage in spaceflight and in other fields.

The life span and cercaria shedding of infected Oncomelania snails in a mountain region of Shitoudi village, Weishan County, Yunnan Province were observed in simulated local ecological environments. 135 infected snails were isolated for observation 3 months after exposure to miracidia in August, 1987. The snail survival rate from the day of initial cercaria shedding to next June, July, August and September was 27.4, 16.3, 13.3 and 11.9% respectively, and the average number of cercariae shed was 139.9, 29.6, 39.2 and 75 per month respectively. The average life span of infected snails was 171.6 days. The average number of cercariae shed per snail in its whole life was 673.0. It was estimated that the average patent period of infected snails was over half a year. As this is the first report in our country in respect to the life span and cercariae shedding of infected snails in a mountain region, the result might be useful for quantitative analysis of epidemiological factors of schistosomiasis in this kind of endemic areas as well as for formulation of control strategy.

13509 Background: We evaluated the feasibility, safety, and immunogenicity of mature, apoptosis tumor cells-pulsed dendritic cell (DC) vaccines administered by intradermal injection. Methods: We performed a randomized study in 16 patients with malignant tumors, including 4 cases for gastric cancer, 3 cases for prostate cancer, 2 cases for breast cancers, one case for lung cancer, esophageal carcinoma, liver cancer , colorectal cancer, kidney cancer, ovarian cancer, endometrial cancer respectively.The vaccine used mature DCs (CD11c++, HLA-DR++, CD83+, and CD86+++) generated from peripheral blood monocytes in the presence of GM-CSF and IL-4. After 5 days, DCs were matured with a defined cocktail of cytokines (IL-1+ TNF-a+PGE2) and simultaneously pulsed with apoptosis autologous tumor cells or heterologous tumor cell lines, for 2 days.Patients were administrated four DC vaccinations (5×106 per time) at 7th day, 14th day, 21st day and 42nd day by intradermal injection(ID). Toxicity effect, life quality, immune function and clinical efficacy were monitored during the whole therapy. Results: Fourteen (82.4%) of 17 patients completed all four vaccinations. Vaccinations were well tolerated; a few patients exhibited less than grade 1 toxicities including rash, transient fever, transient debilitation and injection site reaction. The life quality of most patients had improved to certain degree, including sleep, appetite, mental status, and a good recovery from surgery and chemotherapy. Moreover, the serum level of IL-2 of 10/14 patients increased more than several times to twenty times, and 6/10 patients had a long increase for more than forty days. Serum level of IL-12 were increase in 11/14(9/11 patients increased for more than forty days) patients, Serum level of IFN-? were increase in 11/14(5/11 patients increased for more than forty days ) patients. Conclusions: Administration of this apoptosis tumor cell-pulsed mature DC vaccine by ID routes is feasible and safe. This administration seems to result in superior immunological sensitization as measured by in vitro serum level of immune cell factor such as IL-2, IL-12 and IFN-?. No significant financial relationships to disclose.

Phenol mucilage was injected into the uterine cavities of rats to establish a model of endometrial adhesion, and then decoctions promoting blood circulation and dispersing blood stasis were given to them in order to prevent the formation of adhesion in one group and to treat it in another group. The results of the experiment showed that only a few rats suffered from extensive endometrial adhesion in the prevention group and there was only slight pathological change in the treatment group. This suggests that the prescription is useful in preventing and treating endometrial adhesions of rats induced by phenol mucilage, which provides a scientific basis for its clinical application to the treatment of intrauterine adhesions after curettage for induced abortion. The mechanism of action of the prescription in the prevention and treatment of endometrial adhesions is briefly discussed.

Background A crucial event in the development of the vertebrate neuromuscular junction (NMJ) is the postsynaptic enrichment of muscle acetylcholine (ACh) receptors (AChRs). This process involves two distinct steps: the local clustering of AChRs at synapses, which depends on the activation of the muscle-specific receptor tyrosine kinase MuSK by neural agrin, and the global dispersal of aneural or "pre-patterned" AChR aggregates, which is triggered by ACh or by synaptogenic stimuli. We and others have previously shown that tyrosine phosphatases, such as the SH2 domain-containing phosphatase Shp2, regulate AChR cluster formation in muscle cells, and that tyrosine phosphatases also mediate the dispersal of pre-patterned AChR clusters by synaptogenic stimuli, although the specific phosphatases involved in this latter step remain unknown. Results Using an assay system that allows AChR cluster assembly and disassembly to be studied separately and quantitatively, we describe a previously unrecognized role of the tyrosine phosphatase Shp2 in AChR cluster disassembly. Shp2 was robustly expressed in embryonic Xenopus muscle in vivo and in cultured myotomal muscle cells, and treatment of the muscle cultures with an inhibitor of Shp2 (NSC-87877) blocked the dispersal of pre-patterned AChR clusters by synaptogenic stimuli. In contrast, over-expression in muscle cells of either wild-type or constitutively active Shp2 accelerated cluster dispersal. Significantly, forced expression in muscle of the Shp2-activator SIRPα1 (signal regulatory protein α1) also enhanced the disassembly of AChR clusters, whereas the expression of a truncated SIRPα1 mutant that suppresses Shp2 signaling inhibited cluster disassembly. Conclusion Our results suggest that Shp2 activation by synaptogenic stimuli, through signaling intermediates such as SIRPα1, promotes the dispersal of pre-patterned AChR clusters to facilitate the selective accumulation of AChRs at developing NMJs.