[Influence of thromboelastography-guided hemostatic algorithm on allogeneic transfusion requirements during pediatric hemispherectomy].

Objective: To evaluate the influence of thromboelastography-guided hemostatic algorithm on allogeneic transfusion requirements during pediatric hemispherectomy. Methods: Clinical data of 38 children who underwent hemispherectomy from January 1, 2011 to October 31, 2023 at Xuanwu Hospital of Capital Medical University were retrospective collected. Patients were divided into study group (n=17) and control group (n=21) according to whether thromboelastography was employed to guide hemostatic algorithm. Demographic data and surgical data were recorded. The primary outcomes were allogeneic transfusion rates, including RBC transfusion rate, plasma transfusion rate, and platelets transfusion rate. The second outcomes were estimated blood loss, postoperative seizures during hospitalization, thromboembolic events, and length of hospital stay. Results: There were 13 boys and 4 girls with mean age of (5.7±3.3) years old in study group, and 16 boys and 5 girls with mean age of (7.4±3.4) years old in control group. The surgery duration, anesthesia duration and the proportion of prophylactic administration of tranexamic acid in study group were (424.5±98.5) min, (542.8±106.9) min, and 94.1% (16/17), which were higher than (353.1±85.3) min, (445.3±87.9) min, and 47.6% (10/21) in control group (all P<0.05). The rates of intra- and perioperative allogeneic plasma transfusion in study group were 52.9% (9/17) and 64.7% (11/17) respectively, which were lower than 90.5% (19/21) and 95.2% (20/21) in control group (all P<0.05). The ratio of fibrinogen concentrates administration in study group was 58.8% (10/17), which was higher than that in control group [4.8% (1/21), P=0.001]. There were no statistically differences in intra- and perioperative allogeneic RBC transfusion rates between the two groups (all P>0.05). No platelets were transfused in both groups. There were no statistically differences in estimated blood loss, postoperative seizures during hospitalization and the length of hospital stay between the two groups (all P>0.05). No postoperative thromboembolic events were observed. Conclusion: Thromboelastography-guided hemostatic algorithm can reduce allogeneic plasma transfusion requirements but not RBC transfusion requirements during pediatric hemispherectomy.

[Correlation between postoperative microstructural changes in cerebral white matter and early postoperative cognitive function in patients undergoing meningioma resection].

Objective: To analyze the correlation between microstructure changes in cerebral white matter before and after surgery and early postoperative cognitive function in patients undergoing meningioma resection. Methods: A total of 17 patients who underwent their first meningioma resection at Xuanwu Hospital of Capital Medical University from April 2022 to April 2023 were prospectively included as observation group, with 5 males and 12 females, aged (56.4±7.3) years. Another 15 age- and education-matched patients with cerebral benign tumor were recruited as control group during the same period, with 5 males and 10 females, aged (55.2±8.0) years. Neuropsychological tests (NST), mainly including auditory verbal learning test of Huashan version (AVLT-H), the Montreal cognitive assessment-basic (MoCA-B), clock drawing task-30 (CDT-30), shape trails test-B (STT-B) and animal fluence test (AFT), were conducted at 1 day before surgery, 1 day and within 3-4 days after surgery in the observation group. Simultaneously, magnetic resonance imaging (MRI) scans were performed to collect diffusion tensor imaging (DTI) images at 1 day before surgery and within 3-4 days after surgery. The same NST were conducted at 1 day, 3 days and 6 days after admission in the control group to adjust for learning effects from repeated tests. The microstructure changes of the whole brain white matter were evaluated at the group level by using tract-based spatial statistics (TBSS) technology, including changes of fractional anisotropy (FA), mean diffusion (MD), axial diffusion (AD), and radial diffusion (RD). Then, correlation was performed between DTI indicators with statistically significant and cognitive function. Results: After adjusting for the learning effects, the AVLT-H (R), MoCA-B, and CDT-30 scores decreased, and the evaluation time of STT-B prolonged after surgery in patients with meningioma. And their perioperative decreased values were -0.78 (95%CI:-3.28--0.28) points, -2.22 (95%CI:-4.22--0.72) points, -2.74 (95%CI:-5.29--0.19) points, and 61.49 (95%CI: 5.71-117.27) seconds, respectively, with statistically significant differences (all P<0.05). Group level analysis of TBSS based on DTI images showed decreased FA mainly in the right superior cerebellar peduncle, left posterior limb of internal capsule and genu of corpus callosum, and increased RD mainly in the left anterior corona radiata in patients undergoing meningioma resection, with statistically significant differences (all PFWE<0.05). Linear correlation showed that the perioperative decreased values of FA in genu of corpus callosum and right superior cerebellar peduncle were positively correlated with the perioperative decreased values of AVLT-H (L) after adjusting for learning effects (r=0.72, 0.52, all PFWE<0.05). Conclusions: Patients undergoing meningioma resection are at risk of postoperative cognitive decline. Perioperative decreased values of FA in genu of corpus callosum and right superior cerebellar peduncle based on DTI images are positively correlated with the perioperative decreased values of AVLT-H (L) after adjusting for learning effects.

[The ventilation efficacy and safety of new nasopharyngeal airway applied in left atrial appendage occlusion].

Objective: The present retrospective study aimed to analyses the ventilation efficacy and safety of new nasopharyngeal airway applied in left atrial appendage occlusion. Methods: A total of 37 advanced aged patients diagnosed with atrial fibrillation(>65 years)who underwent left atrial appendage occlusion (LAAO) in Xuanwu Hospital of Capital Medical University from March 2021 to March 2022 were enrolled in this study. All patients received supplemental oxygen by a new nasopharyngeal airway to ensure intraoperative ventilation. The primary outcome was the occurrence of hypoxemia. The secondary outcomes included the incidence of hypotension after anesthesia, the incidence of body movement during surgery, significant fluctuations of the vital signs such as mean arterial pressure (MAP), heart rate (HR), saturation of pulse oxygen (SpO2) and respiratory rate (RR) at different time points (T1: pre-operation; T2: at the time of placing nasopharyngeal airway; T3: at the time of placing transesophageal echocardiography(TEE); T4: at the time of TEE intraoperative exploration; T5: end of the surgery; T6: at the time of patient woke up), and the incidence of postoperative adverse events. Results: There were 24 males and 13 females with a mean age of (73.8±7.7) years. The incidence of hypoxemia was 16.2% (6/37), which could return to normal after simple treatment. The incidence of hypotension was 27.0% (10/37), occurred after anesthesia induction mainly.32.4% (12/37) of the patients experienced movements, but no adverse events led to surgical termination. MAP at different time points was significantly different (P=0.001), but other vital signs of HR, SpO2 and RR were not significantly different(all P>0.05), without serious hemodynamic fluctuations. The incidence of postoperative adverse cardiovascular events was 10.8% (4/37), and delirium was 2.7% (1/37). All patients successfully completed the surgery and were safely discharged from the hospital. Conclusion: The new nasopharyngeal airway can meet the requirements of airway management during left atrial appendage occlusion under intravenous anesthesia without serious adverse events.

[Histopathological diagnosis of pulmonary sclerosing pneumocytoma in needle biopsy specimens].

Objective: To investigate the diagnostic features of pulmonary sclerosing pneumocytoma (PSP) in needle biopsy specimens so as to improve the preoperative diagnostic accuracy and to prevent misdiagnoses. Methods: A total of 79 needle biopsy cases confirmed as PSP in surgical resection specimens were collected in the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China from January 2015 to January 2023. A retrospective analysis was conducted to investigate the clinical, pathological, and immunohistochemical characteristics of PSP. Results: Among the 79 cases, there were 8 males and 71 females, with an age range of 14 to 67 years (median 47 years). Among the 79 needle biopsy cases of PSP, 5 cases were initially misdiagnosed as adenocarcinoma and 1 as carcinoid preoperatively, while the remaining 73 cases were correctly diagnosed. 84.8% (67/79) of the PSP presented with well-defined, homogeneous, solitary solid tumors on chest imaging. Morphologically, 26.6% (21/79) of the PSP mainly showed a single histological component, 67.1% (53/79) contained two histological components, and 6.3% (5/79) contained three histological components. There were no cases containing all four histological components simultaneously. The tumor was composed of cuboidal cells on the surface and round cells in the stroma and lacked significant cytological atypia and mitotic figures. Some cases exhibited variations in histology and cellular morphology, such as glandular spaces (58.2%, 46/79), sclerotic papillae (46.8%, 37/79), hypercellularity (16.5%, 13/79), and cytological atypia (24.1%, 19/79). Immunophenotyping indicated that both tumor cell types expressed TTF1, EMA and ß-catenin, while surface cells expressed pan-cytokeratin and Napsin A, and stromal cells expressed vimentin. In some cases, ER and PR were also expressed. Conclusions: When diagnosing PSP in needle biopsy specimens, the key to avoiding misdiagnosis is recognizing the presence of dual-cell populations within the tumor. The useful clues include presence of cellular papillae, mild cellular atypia, morphological diversity, interstitial foam-like cell aggregates, and prominent background hemorrhage and sclerosis. The characteristic immunophenotype and middle-aged female predilection are also helpful for the diagnosis of PSP.

[Accelerating the transformation from anesthesia clinic to comprehensive anesthesia and multi-disciplinary evaluation, consultation, pre-rehabilitation and follow-up center in outpatient under aged society].

The acceleration of aging process in China bring challenges for the anesthesia management of elderly patients. The co-morbidity, decreased function and high risk of postoperative severe complications and mortality are the main reasons of resultant lower anesthesia and surgery rate,higher medical expenses for elderly patients. The transformation from anesthesia clinic service to comprehensive anesthesia and multi-disciplinary evaluation, consultation,pre-rehabilitation and follow-up center in outpatient is a new medical mode to resolve the problem, which depends on the collaboration among hospital, disciplines and government to undertake the task.

[The applications and challenges of combined monitoring of macro/micro-circulation and mitochondrial homeostasis in early warning of perioperative organ injury].

Perioperative organ injury is a leading risk factor for mortality in surgical patients. Given the current limitations in the timeliness and accuracy of markers for perioperative organ injury, this article proposes a comprehensive early-warning assessment system that jointly monitors the macro-circulation, micro-circulation, and mitochondrial homeostasis. Macro-circulation monitoring allows for real-time evaluation of key indicators such as blood pressure and cardiac output, while micro-circulation monitoring aids in assessing the status of microvascular perfusion. Monitoring of mitochondrial homeostasis provides timely insights into cellular energy metabolism. These three facets are interconnected and collectively determine the balance between tissue oxygenation and energy supply and demand. This article will elucidate commonly used monitoring methods and clinically valuable assessment models within this system, offering theoretical and technical guidance to deepen our understanding of the pathological processes of perioperative organ injury, enhance surgical safety and success rates, and improve patient prognosis and quality of life.

[Campaigning the innovation and practice of anesthesia and perioperative management for elderly patients in China].

The aged population in China is rapidly increasing, but there is a relative lower anesthesia rate with surgical indication for elderly patients because of worry for higher morbidity and mortality. In past five years, Chinese anesthesiologists have made the tremendous efforts to change this situation in as follow aspects. Firstly, establishing the anesthesia and multidisciplinary evaluation system for elderly patients to improve preoperative functional status, and accelerating the postoperative rehabilitation process. Secondly, releasing the publications of perioperative experts consensus for elderly patients based on the high level clinical researches to highlight clinical practice in China. Thirdly, implementing online virtual MDT discussion of anesthesia and perioperative management for critical elderly patients to improve perioperative diagnosis and treatment level. Fourthly, making the innovation of clinical practice and management pathway to adopt to the ERAS' clinical requests for elderly patients, especially advanced aged patients.

[Considerations on pathological diagnosis of inherited metabolic liver disease].

A liver biopsy has an important suggestive role in the diagnosis of inherited metabolic liver disease (IMLD). This article introduces the IMLD pathological diagnosis considerations, five types of classification of liver biopsy based on the morphological characteristics (basic normal liver tissue morphology, steatosis, cholestatic disease, storage/deposition, and hepatitis), and a summary of the pathological characteristics of different injury patterns and common diseases in order to provide clues for the correct diagnosis.

[Clinicopathological analysis of 11 cases of hepatic amyloidosis].

Objective: Hepatic amyloidosis is a metabolic disease with a low incidence rate. However, because of its insidious onset, the rate of misdiagnosis is high, and it usually progresses to a late stage when it is diagnosed. This article analyzes the clinical features of hepatic amyloidosis by combining clinical pathology in order to improve the clinical diagnosis rate. Methods: Clinical and pathological data of 11 cases of hepatic amyloidosis diagnosed at the China-Japan Friendship Hospital from 2003 to 2017 were summarized and analyzed retrospectively. Results: The clinical manifestations of 11 cases mainly included abdominal discomfort (4/11), hepatomegaly (7/11), splenomegaly (5/11), fatigue (6/11), etc. Biochemical test results showed that most patients' alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transferase, total bilirubin, direct bilirubin, and total bile acids, accompanied by hypoalbuminemia were elevated, while some patients' 24-h urinary protein, creatinine, and blood urea nitrogen were elevated. Conclusion: All patients had slightly elevated aspartate transaminase levels (within 5 times the upper limit of normal), and 72% had slightly elevated alanine transaminase. Alkaline phosphatase and γ-glutamyl transferase levels were significantly raised in all cases, with the highest result for γ-glutamyl transferase being 51 times the upper limit of normal. Damage to the hepatocytes has an effect on the biliary system as well, leading to symptoms such as portal hypertension and hypoalbuminemia [(0.54~0.63) × upper limit of normal value, 9/11]. Amyloid deposits within the artery wall (54.5% of patients) and portal vein (36.4% of patients) were also indicative of vascular injury. A liver biopsy should be recommended for patients with unexplained elevated transaminases, bile duct enzymes, and portal hypertension in order to establish a definitive diagnosis.

[Histological regression and clinical benefits in patients with liver cirrhosis after long-term anti-HBV treatment].

Objective: Our study aims to determine histological regression and clinical improvement after long-term antiviral therapy in hepatitis B virus-related cirrhosis patients. Methods: Treatment-naïve chronic hepatitis B patients with histologically or clinically diagnosed liver cirrhosis were enrolled. Liver biopsies were performed after 5 years entecavir-based antiviral treatment. Patients were followed up every 6 months. Cirrhosis regression was evaluated based on Metavir system and P-I-R score. Clinical improvement was evaluated before and after the long-term treatment. Kruskal Wallis test and Wilcoxon signed-rank test were used for continuous variables, Fisher's exact test was used for categorical variables and multivariate analysis was performed using logistic regression analysis. Results: Totals of 73 patients with HBV-related liver cirrhosis were enrolled. Among them, 30 (41.1%) patients were biopsy proved liver cirrhosis and the remaining 43 (58.9%) cirrhotic patients were diagnosed by clinical features. Based on Metavir system and P-I-R score, 72.6% (53/73) patients attained histological regression. Furthermore, 30.1% (22/73) were defined as significant regression (Metavir decrease ≥2 stage), 42.5% (31/73) were mild regression (Metavir decrease 1 stage or predominantly regressive by P-I-R system if still cirrhosis after treatment) and 27.4% (20/73) were the non-regression. Compared to levels of clinical characteristics at baseline, HBV DNA, ALT, AST, liver stiffness(decreased from 12.7 to 6.4 kPa in significant regression, from 18.1 to 7.3 kPa in mild regression and from 21.4 to 11.2 kPa in non-regression)and Ishak-HAI score significantly decreased after 5 years of anti-HBV treatment, while serum levels of platelets and albumin improved remarkably (P<0.05). In multivariate analysis, only the pre-treatment liver stiffness level was associated with significant regression (OR=0.887, 95%CI: 0.802-0.981, P=0.020). Conclusions: After long-term antiviral therapy, patients with HBV-related cirrhosis are easily to attain improvements in clinical parameters, while a certain percentage of these patients still cannot achieve histological reversal.

[The low-dose opioids therapy of perioperative multi-mode analgesia is pivotal to the enhanced recovery after surgery for elderly patients].

The implementation of enhanced recovery after surgery in elderly patients should be under the premise of adequate perioperative analgesia/anti-stress. The aims of perioperative multimodal low-dose opioids analgesia therapy are reducing opioid-related adverse reactions and the impact on process of postoperative recovery.

[Clinicopathological analysis of 16 cases of pyrrolizidine alkaloids-associated hepatic sinusoidal obstruction syndrome].

Objective: To observe the histopathological manifestations of liver biopsy in patients with hepatic sinusoidal obstruction syndrome (HSOS) induced by pyrrolizidine alkaloid (PA). Methods: Patients diagnosed with PA-HSOS from 2012 to 2017 were selected, and the general conditions, liver function indexes, medication history, liver biopsy time, histopathological slides of liver biopsy, and follow-up data of clinical prognosis after 6 months of onset were collected. Clinical staging with clinical data was used to observe the histopathological manifestations of patients at different clinical stages. Wilcoxon rank-sum test, unpaired t-test and univariate linear regression analysis were used for data analysis. Results: A total of 16 cases were collected. Alanine transaminase and aspartate transaminase was 59.25 U/L and 25.50 U/L, 108 U/L and 45 U/L, respectively, after 6 months of onset and follow-up, and the differences were statistically significant. Moreover, total bile acids and albumin was 35 µmol/L and 36.15 µmol/L, and 32.45 g/L and 31 g/L, respectively, and the differences were not statistically significant. PA-HSOS pathological development process was divided into early, middle and late stages. In the early stage, the central lobular sinusoidal endothelium integrity was impaired and the entry of erythrocytes had interspersed thin reticular fibers and perisinusoidal space. In the middle stage (hemorrhagic zone), erythrocytes, reticular fibers and collagen fibers were lysed, densely collapsed and deposited. The cavity of the bloodstream was hyperemic and dilated, and the cavity was covered with sinus endothelial cells. The hepatic plate regenerated around the hemorrhagic zone and some of the hepatic sinuses were decompensated. In the late stage, deposited collagen in the hemorrhagic zone had formed a large fibrous scar, and most of the dilated cavity in the bloodstream was covered with vascular endothelium. The marginal zone hepatic cells were regenerated in two rows and gradually inserted into the fibrous septum. Different hepatic lobular lesions obtained from the same patients liver biopsy tissues were changed at different stages. Hepatic lobule injury proportion with severe internal bleeding in liver biopsy tissue had no relation with the prognosis of patients. Conclusion: In the early stage of PA-HSOS, erythrocytes in the central zone of lobules enter the perisinusoidal space through the damaged sinus endothelium, which is manifested as hepatic plate hemorrhagic necrosis. In the middle and late stage, liver plate regeneration and vascular remodeling occurred, so most of the patients' clinical course was self-limited. Pathological staging and liver biopsy time have an apparent correlation, but the prognosis of patients cannot be judged based on the extent of hemorrhage and injury of biopsy samples.

[Continuous fascia iliaca compartment block combined with oral analgesics for pre-operative pain control in elderly hip fracture patients].

Objective: The purpose of this study was to assess the efficacy of ultrasound-guided continuous fascia iliaca compartment block combined with oral analgesics for pre-operative pain control in elderly patients with hip fracture. Methods: One hundred and sixteen patients with hip fractures in Xuan Wu Hospital of Capital Medical University during Dec. 2015 to Dec. 2016 were included. These patients were randomized into 2 groups: control group (group C) (receiving the traditional analgesia: tramadol 50 mg and paracetamol 500 mg tid, po from admission to surgery), study group (group S) (receiving ultrasound-guided continuous fascia iliaca compartment block combined with oral analgesics for pre-operative pain control from admission to surgery). Pain relief or pain intensity was assessed preoperatively at before administration of analgesia (T0), 1 h after administration of analgesia (T1), the second day after admission(T2), in the morning of surgery day (before surgery) (T3) using a visual analog scale. The satisfaction score with the analgesic regimen preoperatively was recorded. The amount of rescue analgesia, occurrence of adverse events (nausea, vomiting, respiratory depression, over sedation) and continuous fascia iliaca compartment block complications were also collected. Results: Pain scores (VAS) at passive movement of group S were significantly lower at T1 (32±8), T2 (32±8) and T3 (34±7) than that at T0 (73±12) (all P<0.05). VAS at rest of group S were significantly lower than those of group C at T3 (t=3.488, P<0.05). VAS at passive movement of group S were significantly lower than those of group C at T1,T2,T3 (P<0.05). The satisfaction score with the analgesic regimen was greater in group S (74±10) than that in group C (46±11) (t=-14.209, P<0.05). The incidence of rescue analgesia was lower in group S (0) than in group C (17.2%) (χ2=5.472, P<0.05). The occurrence of nausea and vomiting was 6.9% and 1.7% in group S, which were lower than that in group C (22.4%, 12.1%) (χ2=6.779, 2.416, all P<0.05). There were no obvious complications of continuous fascia iliaca compartment block in group S. Conclusion: Ultrasound guided continuous fascia iliaca compartment block combined with oral analgesics preoperatively is an effective way of providing analgesia for elderly with hip fracture, which can improve the patient's comfort and satisfaction.

On the manifestation of higher-order nonlinearities in a noble gas medium undergoing strong ionization.

While there is a consensus that higher-order effects beyond χ(3) are present also in high-intensity light-matter interactions, when and how they become apparent needs further study. The central question addressed in this Letter is whether it is possible to design a situation in which they show up before being completely masked by the electrons freed by a high-intensity field. The second question we attempt to answer is how much such observations, if and when feasible, can reveal about the nature of the nonlinear polarization. We answer the first question in the affirmative, but our comparative simulations indicate that distinguishing the higher-order nonlinearity from the third-order polarization can be extremely challenging. We also briefly discuss the implications for the interpretation of the measured values of the nonlinear index.

The role of laminins in cartilaginous tissues: from development to regeneration.

As a key molecule of the extracellular matrix, laminin provides a delicate microenvironment for cell functions. Recent findings suggest that laminins expressed by cartilage-forming cells (chondrocytes, progenitor cells and stem cells) could promote chondrogenesis. However, few papers outline the effect of laminins on providing a favorable matrix microenvironment for cartilage regeneration. In this review, we delineated the expression of laminins in hyaline cartilage, fibrocartilage and cartilage-like tissue (nucleus pulposus) throughout several developmental stages. We also examined the effect of laminins on the biological activities of chondrocytes, including adhesion, migration and survival. Furthermore, we scrutinized the potential influence of various laminin isoforms on cartilage-forming cells' proliferation and chondrogenic differentiation. With this information, we hope to facilitate the understanding of the spatial and temporal interactions between cartilage-forming cells and laminin microenvironment to eventually advance cell-based cartilage engineering and regeneration.

[Qualitative pathological assessment of liver fibrosis regression after antiviral therapy in patients with chronic hepatitis B].

Objective: To investigate the methods for qualitative pathological assessment of dynamic changes in liver fibrosis/cirrhosis after antiviral therapy in patients with chronic hepatitis B (CHB), since antiviral therapy can partially reverse liver fibrosis and cirrhosis caused by hepatitis B and semi-quantitative, rather than qualitative, pathological assessment is often used for the research on liver fibrosis regression. Methods: Previously untreated CHB patients with liver fibrosis and cirrhosis were enrolled, and liver biopsy was performed before treatment and at 78 weeks after the antiviral therapy based on entecavir. The follow-up assessment was performed once every half a year. Based on the proportion of different types of fibrous septum, we put forward the new qualitative criteria called P-I-R classification (predominantly progressive, predominantly regressive, and indeterminate) for evaluating dynamic changes in liver fibrosis. This classification or Ishak fibrosis stage was used to evaluate the change in liver fibrosis after treatment and Ishak liver inflammation score was used to evaluate the change in liver inflammation after treatment. Results: A total of 112 CHB patients who underwent liver biopsy before and after treatment were enrolled, and among these patients, 71 with an Ishak stage of ≥3 and qualified results of live biopsy were included in the final analysis. Based on the P-I-R classification, 58% (41/71) were classified as predominantly progressive, 29% (21/71) were classified as indeterminate, and 13% (9/71) were classified as predominantly regressive; there were no significant differences between the three groups in alanine aminotransferase, aspartate aminotransferase, albumin, HBeAg positive rate, HBV DNA, and liver stiffness (P < 0.05). After treatment, the proportion of predominantly progressive, indeterminate, or predominantly regressive patients changed to 11% (8/71), 11% (8/71), and 78% (55/71), respectively. Among the 35 patients who had no change in Ishak stage after treatment, 72% (25/35) were classified as predominantly regressive and had certain reductions in the Laennec score, percentage of collagen area, and liver stiffness. Conclusion: This new P-I-R classification can be used to assess the dynamic changes in liver fibrosis after antiviral therapy in CHB patients.

Risk factors for incidence and case-fatality rates of healthcare-associated infections: a 20-year follow-up of a hospital-based cohort.

Information is lacking on the integrated evaluation of mortality rates in healthcare-associated infections (HAIs). Our aim was to differentiate the risk factors responsible for the incidence from those for the case-fatality rates in association with HAIs. We therefore examined the time trends of both incidence and case-fatality rates over a 20-year period at a tertiary-care teaching medical centre in Taiwan and the mortality rate was expressed as the product of the incidence rate and the case-fatality rate. During the study period the overall mortality rate fell from 0·46 to 0·32 deaths/1000 patient-days and the incidence rate fell from 3·41 to 2·31/1000 patient-days, but the case-fatality rate increased marginally from 13·5% to 14·0%. The independent risk factors associated with incidence of HAIs were age, gender, infection site, admission type, and department of hospitalization. Significant prognostic factors for HAI case-fatality were age, infection site, intensive care, and clinical department. We conclude that the decreasing trend for the HAI mortality rate was accompanied by a significant decline in the incidence rate and this was offset by a slightly increasing trend in the case-fatality rate. This deconstruction approach could provide further insights into the underlying complex causes of mortality for HAIs.

[Expression and mechanism of nitric oxide synthase in cerebral hyperperfusion rats].

OBJECTIVE: To explore the expression and mechanism of different nitric oxide synthase in cerebral hyperperfusion rats. METHODS: Male Wistar rats were anesthetized and a ventral midline incision was made. The bilateral common carotid arteries were gently separated. Each artery was ligated with a 5-0 silk suture. Sham groups underwent the same operation without occlusion two weeks later, the ligature was loosened under a microscope to induce reperfusion. Phenylephrine was administered at concentration of 50 µg/ml via tail vein.After hyperperfusion, the expression of iNOS and eNOS in hippocampus , cortex and common carotid arteries of rats brain was observed by using Western blot of each group. RESULTS: The expression of iNOS in differernt sites were increased significantly after reperfusion of 24 hours. The ratio of iNOS and ß-actin in hippocampus in sham, BCAO, HP, HP 24 and HP 48 groups were 21.10±2.53, 24.37±2.30, 28.34±2.86, 43.76±2.58, 38.90±3.17, respectively. There was significant difference between HP 24 and other groups (F=13.03, all P<0.05). The ratio of iNOS and ß-actin in cortex in each group were 12.98±2.31, 15.00±1.66, 14.71±1.48, 34.76±5.01, 32.60±5.73, respectively (F=8.42, all P<0.05). The ratio of iNOS and ß-actin in common carotid arteries in each group were 7.30±2.55, 8.83±1.45, 4.76±0.71, 28.00±2.21, 26.29±3.33 (F=24.82, all P<0.05). While the levels of eNOS in that three sites presented no significant change(all P>0.05). CONCLUSIONS: Hyperperfusion can induce iNOS ecpression in quantities in hippocamps, cortex and common carotid arteries. These levesl would last until 48 hours after reperfusion. This process suggests that iNOS is the possible mechanism of hyperperfusion.