Clenbuterol Prevents Mechanical Unloading-Induced Myocardial Atrophy via Upregulation of Transient Receptor Potential Channel-3

Left ventricular assist device in combination with clenbuterol has been demonstrated to significantly improve heart function in patients with advanced heart failure. However, the roles of clenbuterol in mechanical unloading and its underlying mechanism are poorly understood. A rat abdominal heart transplantation model has been developed to mimic mechanical unloading of the heart. The recipient rats were randomly segregated into experimental groups for the daily administration of either saline (the "Trans" group; n = 13) or clenbuterol (2 mg/kg, the "Trans + CB" group; n = 12). Another group of 10 rats served as a treatment mimic control/sham animals (the "Sham" group). All interventions were performed via intraperitoneal injections once daily for 4 weeks. The Trans group animals exhibited myocardial atrophy and dysfunction with decreased expression levels of transient receptor potential channel 3 (TRPC3) and phospholipase C-β1 (PLC-β1) at 4 weeks post-transplantation. Administration of clenbuterol improved cardiac function, prevented myocardial atrophy, and restored expression of TRPC3 and PLC-β1 in the unloaded hearts of the "Trans + CB" animals at 4 weeks post-transplantation. Silencing of the TRPC3 gene by siRNA inhibited the pro-hypertrophic effect of clenbuterol in the rat primary cardiomyocytes in vitro. Furthermore, U73122, an inhibitor of the PLC-β1/diacylglycerol (DAG) pathway, significantly attenuated clenbuterol-induced upregulation of TRPC3 in cardiomyocytes. These findings suggest that the anti-atrophic effect of clenbuterol may be dependent on the upregulation of TRPC3 through the activation of the PLC-β1/DAG pathway during mechanical unloading. The results of our study reveal a potential target for the prevention and treatment of mechanical unloading-induced myocardial atrophy.

Transitional Dynamics of Sarcopenia and Associations of Nutritional Indices with State Transitions in Chinese aged ≥ 50

OBJECTIVES

Sarcopenia's temporal profile can be regarded as a dynamic process with distinct states, in which malnutrition plays an important role. This study aimed to address two research gaps: sarcopenia's transitional dynamics and associations of nutritional indices with state transitions in community-dwelling Chinese adults aged 50 and older.

DESIGN

A prospective population-based cohort study.

SETTING

Community-based setting in western China.

PARTICIPANTS

The analytic sample included data from 1910 participants aged ≥ 50 in the West China Health and Aging Trend study between 2018-2022.

MEASUREMENTS

We defined three states: the initial normal state (normal muscle strength, physical performance and muscle mass), the worst sarcopenia state (low muscle mass plus low muscle strength and/or low physical performance) and the intermediate subclinical state (the other scenarios). The relevant measurement methods and cut-off points were based on the 2019 AWGS consensus. Using a continuous-time multistate Markov model, we calculated probabilities of transitions between different states over 1, 2 and 4 years; we also examined associations between nutritional indices and transitions, including body mass index (BMI), calf circumference (CC), mid-arm circumference (MAC), triceps skinfold thickness (TST), albumin (ALB), geriatric nutrition risk index (GNRI), vitamin D (VitD) and prealbumin (PA).

RESULTS

For individuals in the normal state, their probabilities of remaining stable versus progressing to a subclinical state were 53.4% versus 42.1% at 2 years, and 40.6% versus 49.0% at 4 years. In the subclinical population, their 2- and 4-year chances were 60.2% and 51.2% for maintaining this state, 11.8% and 16.2% for developing sarcopenia, 28.0% and 32.6% for reverting to normal. For sarcopenic individuals, the likelihood of staying stable versus retrogressing to the subclinical state were 67.0% versus 26.3% at 2 years, and 48.3% versus 36.3% at 4 years. Increased BMI, CC, MAC, TST, ALB, GNRI and PA correlated with reversion from the subclinical state, among which increased TST, ALB and PA were also paralleled with reversion from sarcopenia, while decreased BMI, CC, MAC, TST and GNRI were associated with progression to sarcopenia. VitD was not significantly associated with any transitions.

CONCLUSION

This study reveals how sarcopenia changes over time in a Chinese population. It also highlights the usefulness of simple and cost-effective nutritional status indices for indicating state transitions, which can help identify individuals at risk of sarcopenia and guide targeted interventions within the optimal time window.

Cohort Profile: West China Health and Aging Trend (WCHAT)

OBJECTIVES

The West China Health and Aging Trends study (WCHAT) is intended to focus on the research that will guide efforts to reduce disability, maximize health and independent functioning, and enhance quality of life at older ages in different ethnicities. And provide the basis for understanding trends and dynamics in late-life functioning, how these differ in various ethnic subgroups, and the economic or social consequences of aging and disability in western China.

PARTICIPANTS

The cohort enrolled 7536 participants and 7439 participants aged 50 years and older in the baseline in 2018 and every year would be followed up. Finding to date: The data in WCHAT were prospectively collected from Yunnan, Guizhou, Sichuan and Xinjiang by 7 medical institutions. A number of age-related outcome measures were collected though corresponding geriatric assessments. Blood testing, saliva, urine and feces testing are available for all cohort participants. Future plans: The data in WCHAT can be used for various types of epidemiological research, particularly for examining how the culture specific life styles and diet influences geriatrics related outcomes. We are initially planning cohort studies and established a sample biobank in relation to the risk and prognosis of frailty, sarcopenia and other geriatric syndromes. Strengths and limitations of this study: It is a first multi-ethnic cohort study in West China that aimed to investigate the influence of culture specific life styles, diet and living environment on the prevalence of geriatric syndromes like frailty, sarcopenia and so on. This is a prospective multi-center observational study, which will be conducted in various ethnic groups gathering places. This study collected information that related to fatigue, falls, and cognition were obtained through self-reports, which might have recall bias and grouping errors. This study has problems such as the interviewees' refusal to visit, death, going out, and large population mobility may lead to high loss of visit rates. This study collected information from a comparatively healthier elderly population in which external validity was limited.

Three-dimensional assessment of root migration and rotation patterns after coronectomy: bone-embedded roots versus soft tissue-covered roots

In this study, a three-dimensional evaluation was performed to explore differences between bone-embedded and soft tissue-covered roots after mandibular third molar (M3M) coronectomy. Patients were recruited according to the results of cone-beam computed tomography, 6 months after coronectomy. Completely bone-embedded M3Ms were assigned to group B, while completely soft tissue-covered M3Ms were assigned to group S. Data were recorded using digital software. A total of 213 M3Ms in 181 patients were investigated, of which 170 were assigned to the two study groups. Age was the primary factor influencing root migration (P<0.001). The smaller the degree of angulation of the M3M, the more likely was the root complex to rotate distally (r=-0.37, P<0.001). The depth of the impacted M3M contributed to the regeneration of new bone (P≤0.008). The length of the root complex (odds ratio 0.82, P=0.048) and distance from the root to the alveolar crest (odds ratio 1.23, P=0.026) were two critical factors influencing whether the root complex was bone-embedded. Ensuring that the length of the root complex is <7.6mm and the distance between the root and alveolar crest is ≥5mm were both found to be critical to the remaining root being completely bone-embedded and thus preventing eruption and the need for secondary surgery.

[Comparison of short-term and long-term outcomes between thoracoscopic pneumonectomy and open pneumonectomy for non-small cell lung cancer: a study based on propensity score matching]

Objective: To compare the short-term and long-term results of thoracoscopic and open pneumonectomy for non-small cell lung cancer. Methods: The clinical data of patients with non-small cell lung cancer who underwent pneumonectomy in the Department of Thoracic Surgery, Qingdao University Hospital from January 2008 to December 2016 were collected. Totally 142 patients (55 in the thoracoscopic group and 87 in the open group) were included in the study. A total of 29 pairs of patients were successfully matched by propensity score matching (PSM). Perioperative outcomes and overall survival were compared between the two groups using t test, χ(2) test, Kaplan-Meier curve and Log-rank test, respectively. Results: Camparion with open group, the thoracoscopic group had longer operative time ((209.7±70.2) minutes vs. (171.3±43.5) minutes, t=2.50, P=0.02), more mediastinal lymph node dissection (M(Q(R)): 17(9) vs. 11(10), W=388, P=0.02) and shorter postoperative hospital stay (7.0(3.5) vs. 9.0(3.0), W=285, P=0.03). There was no significant difference in estimated blood loss, postoperative drainage time, dissected lymph node number, dissected lymph node station and perioperative complications. After PSM, there were no signifificant differences found in 3-year survival (71.4% vs. 48.1%, P=0.10) and 3-year disease-free survival (67.4% vs. 47.2%, P=0.13) between the two groups. Conclusion: Thoracoscopic pneumonectomy is safe and feasible for the treatment of non-small cell lung cancer with more mediastinal lymph node dissection and accelerating recovery, and equivalent long-term prognosis when compared with open approach.

Sarcopenia, Obesity and Sarcopenia Obesity in Comparison: Prevalence, Metabolic Profile, and Key Differences: Results from WCHAT Study

OBJECTIVE

To identify the prevalence, lifestyle factors, chronic disease status, and assessing the metabolic profile, comparing key differences in a cohort of subjects with non-sarcopenia/non-obesity (H), sarcopenia/non-obesity (S), non-sarcopenia/obesity (O) and sarcopenia obesity (SO) in a multi-ethnic population in west China.

DESIGN

A cross-sectional study.

SETTING

The communities in Yunnan, Guizhou, Sichuan, and Xinjiang provinces.

PARTICIPANTS

We included 4,500 participants aged 50 years or older who did bioelectrical impedance in our analysis from West China Health and Aging Trend (WCHAT) study.

MEASUREMENTS

We measured gait speed, handgrip strength and muscle mass by using bioelectrical impedance analysis (BIA) for all participants. We defined sarcopenia using the diagnostic algorithm recommended by the Asian Working Group for Sarcopenia (AWGS). Obesity was defined as the highest sex-specific quintile of the percentage body fat. Different variables like anthropometry measures, life styles, chronic disease and blood test were collected. Analysis of variance and a multinomial logistic regression analysis adjusting for covariates were used to assess the differences of metabolic profiles among different groups.

RESULTS

Of 4500 participants aged 50 years old or older, the proportions of H, O, S, SO were 63.0%, 17.7%, 16.7% and 2.6%, respectively. And the prevalence of S subjects in men was 18.3% and 15.7% in women, while the prevalence of SO was 3.7% in men and 2.0% in women. Data showed that the prevalence of S and SO has an aging increase pattern which was opposite with O. Both S and SO tends to be older, lower educational level, without spouse, smoking, comorbidity of chronic disease, poor nutrition status, depression and cognitive decline compared to H and S seems to be worse than SO. Compared to H, S cohort showed a decrease in Vitamin D, triglyceride, albumin, fasting glucose, insulin, creatinine, ALT, nutrition scores and increase in HDL. SO cohort were observed for an increase in cholesterol, LDL, total protein and decrease in vitamin D. While O cohort showed an increase in triglyceride, cholesterol, LDL, total protein, glucose, insulin, WBC, uric acid, ALT and nutrition scores, but a decrease in HDL and vitamin D level.

CONCLUSIONS

Among individuals aged 50 years old or older in West China. S, O and SO participants demonstrate distinct differences in the life-styles, chronic disease profile, and metabolic profiles. The prevalence of S and SO has an aging increase pattern contrary to O. Both S and SO tend to be older, lower educational level, without spouse, smoking, comorbidity of chronic disease, poor nutrition status, depression and cognitive decline compared to H and S looks like to be worse than SO. Besides, the S subjects seem to have more metabolic index changes than SO compared to H. While O subjects have some contrary metabolic index to S subjects.

Prevalence and Its Associated Factors of Physical Frailty and Cognitive Impairment: Findings from the West China Health and Aging Trend Study (WCHAT)

OBJECTIVES

Previous literature has reported that physical frailty (PF) closely associated with cognitive impairment (CI). In this study, we aim to describe and evaluate the prevalence and associated factors with different patterns of PF and cognitive impairment.

DESIGN

A cross-sectional study.

SETTING AND PARTICIPANTS

Community-dwelling older adults aged ≥60 from the West China Health and Aging Trend (WCHAT) study were included in this study.

MEASUREMENTS

Participants were assessed the PF and cognitive impairment. PF was assessed using the physical phenotype as defined by Fried's criteria. Cognitive impairment was identified using the Short Portable Mental Status Questionnaire (SPMSQ). According different patterns of PF and cognitive impairment, participants were divided into 4 groups: not-PF and cognitive intact ( "neither" group), not-PF and cognitive impairment ("CI only" group), PF and cognitive intact ("PF only" group), and PF and cognitive impairment ("both" group). Multinomial logistic regression was used to explore the association between medical conditions and different patterns of PF and cognitive impairment after adjusting the demographic characteristics.

RESULTS

Among 4,103 participants (age 67.8 + 5.9 years, female 58.3%), 78.8%, 3.9%, 14.5% and 2.9% were "neither", "PF only", "CI only", and "both", respectively. The prevalence of "PF only", "CI only" and "both" were associated with age, lower education level and single status. In addition, there was substantial ethnicity heterogeneity in the prevalence of different patterns of PF and cognitive impairment. Comparing with "neither", PF and/or cognitive impairment had higher association with depression, ADLs impairment, and malnutrition. Of note, obesity was only significantly associated with "PF only", but not associated with "CI only" or "both".

CONCLUSIONS

We found the substantial demographic and medical conditions disparities in different patterns of PF and cognitive impairment. Further research should focus on the efficient and practical screen to predict the risk of "PF only", "CI only" and "both".

Tumour stiffness associated with tumour response to conventional transarterial chemoembolisation for hepatocellular carcinoma: preliminary findings

AIM

To evaluate whether elastic (stiffness) characteristics of tumours were associated with treatment responses and survival of patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolisation (TACE).

MATERIALS AND METHODS

A retrospective cohort study of 59 HCC patients with unresectable HCC who underwent TACE was undertaken. Acoustic radiation force impulse imaging (ARFI) was used to measure tissue stiffness of the index tumours and non-tumoural liver before TACE treatment. The correlation between the parameters of tumour stiffness and treatment response to TACE was assessed using mRECIST criteria as well as according to patient survival.

RESULTS

Tumour stiffness and its stiffness difference between tumour and non-tumoural liver were significantly associated with tumour response to TACE (p=0.019 and 0.010, respectively). Patients with tumour stiffness of <2 m/s or stiffness difference between tumour and non-tumoural liver of <0.5 were more likely to have treatment response to TACE. Univariate analysis showed that the difference in stiffness between tumour and non-tumoural livers (p=0.039) was one of the significant predictors of overall survival (OS). In multivariate analysis, alpha-fetoprotein (AFP) (p=0.006) and Barcelona Clinic Liver Cancer (BCLC) stage (p=0.017) were identified as independent predictors of survival.

CONCLUSION

Tumour stiffness characteristics might be an added predictive marker of treatment response to TACE in patients with HCC.

Lymphatic system identification, pathophysiology and therapy in the cardiovascular diseases

The mammalian circulatory system comprises both the cardiovascular system and the lymphatic system. In contrast to the closed, high-pressure and circular blood vascular circulation, the lymphatic system forms an open, low-pressure and unidirectional transit network from the extracellular space to the venous system. It plays a key role in regulating tissue fluid homeostasis, absorption of gastrointestinal lipids, and immune surveillance throughout the body. Despite the critical physiological functions of the lymphatic system, a complete understanding of the lymphatic vessels lags far behind that of the blood vasculatures due to the challenge of their visualization. During the last 20 years, discoveries of underlying genes responsible for lymphatic vessel biology, combined with state-of-the-art lymphatic function imaging and quantification techniques, have established the importance of the lymphatic vasculature in the pathogenesis of cardiovascular diseases including lymphedema, obesity and metabolic diseases, dyslipidemia, hypertension, inflammation, atherosclerosis and myocardial infraction. In this review, we highlight the most recent advances in the field of lymphatic vessel biology, with an emphasis on the new identification techniques of lymphatic system, pathophysiological mechanisms of atherosclerosis and myocardial infarction, and new therapeutic perspectives of lymphangiogenesis.

Relieving phantom limb pain with multimodal sensory-motor training

OBJECTIVE

The causes for the disabling condition of phantom limb pain (PLP), affecting 85% of amputees, are so far unknown, with few effective treatments available. Sensory feedback based strategies to normalize the motor commands to control the phantom limb offer important targets for new effective treatments as the correlation between phantom limb motor control and sensory feedback from the motor intention has been identified as a possible mechanism for PLP development.

APPROACH

Ten upper-limb amputees, suffering from chronic PLP, underwent 16 days of intensive training on phantom-limb movement control. Visual and tactile feedback, driven by muscular activity at the stump, was provided with the aim of reducing PLP intensity.

MAIN RESULTS

A 32.1% reduction of PLP intensity was obtained at the follow-up (6 weeks after the end of the training, with an initial 21.6% reduction immediately at the end of the training) reaching clinical effectiveness for chronic pain reduction. Multimodal sensory-motor training on phantom-limb movements with visual and tactile feedback is a new method for PLP reduction.

SIGNIFICANCE

The study results revealed a substantial reduction in phantom limb pain intensity, obtained with a new training protocol focused on improving phantom limb motor output using visual and tactile feedback from the stump muscular activity executed to move the phantom limb.

[Accuracy and reliability of three-dimensional craniofacial cone-beam CT superimposition method based on voxel registration]

OBJECTIVE

To set up a three-dimensional(3D)craniofacial cone-beam CT(CBCT)superimposition method based on voxel registration, and evaluate the accuracy and reliability of different reference superimposition areas.

METHODS

CBCT scans were taken on a dry skull for three times with a time-interval of two weeks, and CBCT scans were taken on ten adult volunteers twice with a time-interval of one month. The 3D superimposition based on voxel registration was set up by means of Analyze 12.0. The bilateral-zygomatic bone and anterior cranial base were selected as different reference areas for voxel overlapping. The 3D overlapping images were output into Geomagic Qualify 2013, and the surface distances on different craniofacial regions were measured. Three operators repeated three times of these superimposition and measurement. SPSS 19.0 were used to analyze the accuracy and reliability.

RESULTS

When bilateral-zygomatic bone used as superimposition reference, the mean surface distance range of dry skull were from 0.035 to 0.064 mm, and volunteers from 0.099 to 0.182 mm. When the anterior cranial base used as superimposition reference, the mean surface distance range of dry skull were from 0.038 to 0.071 mm, and volunteers from 0.127 to 0.218 mm. All these mean values were less than the CBCT voxel size 0.25 mm(P<0.05), and got sub-pixel precision. No significant difference was found between the different operators at different times(P>0.05).

CONCLUSIONS

This study showed the high accuracy and reliability of 3D CBCT superimposition based on voxel registration, either the anterior cranial base or the bilateral-zygomatic bone as reference. This method could be used for evaluating 3D craniofacial treatment effects.

Partial sialoadenectomy for the treatment of benign tumours in the submandibular gland

The conventional treatment for benign tumours arising in the submandibular gland (SMG) has always involved whole gland excision with the tumour. In light of developments in parotid gland functional surgery, this prospective study was performed to evaluate the effectiveness and safety of partial sialoadenectomy (PS) for benign tumours in comparison with conventional total sialoadenectomy (TS). Thirty-one consecutive patients with a preoperative diagnosis of benign tumour in the SMG were included in the study from December 2008 to December 2010. Eleven patients were treated with PS and 20 patients underwent conventional TS. Salivary gland function and surgery-related complications were assessed. No difference in resting saliva flow was found between the two groups before the operation, while this was significantly higher in the PS group than in the TS group at 1 year after surgery (P=0.009). With regard to complications, there was less deformity in facial appearance in the PS group. There was no recurrence in any of the 31 patients during the follow-up period (range 41-82 months). It is believed that this modification to SMG surgery is consistent with the idea of functional and minimal invasive salivary gland surgery. This technique represents a good choice for the management of benign tumours of the SMG for appropriately selected cases.

Ligation-assisted endoscopic enucleation for the treatment of colorectal submucosal tumours originating in the muscularis propria

AIM

A ligation-assisted endoscopic enucleation (EE-L) technique was developed and was evaluated to determine its efficacy and safety for treating colorectal submucosal tumours (< 10 mm) originating in the muscularis propria.

METHOD

EE-L was used to treat 13 patients between January 2011 and January 2014. The tumour was sucked into a transparent cap and ligated at its base by a rubber band ligature attached to the tip of the endoscope. With the creation of a pseudo-stalk, the tumour was then enucleated using endoscopic dissection and the wound was closed with clips.

RESULTS

All tumours [median diameter 6.8 (4-10) mm] were successfully enucleated [procedure time 19 (11-27) min]. Histopathological examination identified 11 (84.6%) to be leiomyoma and 2 (15.4%) low-risk gastrointestinal stromal tumours. No perforations or massive haemorrhage occurred and there were no recurrences during a follow-up of 3-39 months.

CONCLUSION

EE-L is a successful technique for the removal of small colorectal tumours in the muscularis propria with few complications and enables a histopathological diagnosis. In this study, all the resected lesions had a benign pathology.

A new oxovanadium complex enhances renal function by improving insulin signaling pathway in diabetic mice

AIM

Since vanadium complexes have insulin-mimetic effects and can be used to treat complications of diabetes, we aimed to screen a new oxovanadium complex with a low toxicity, and investigate its insulin-mimetic effects, as well as the mechanism of improvement to diabetic mouse renal function.

METHODS

Cells were treated with oxovanadium complexes, and viability was assessed by MTT assay. Diabetic mouse model was established using alloxan. Blood urea nitrogen (BUN) and serum creatinine (SCr) in the mice were measured using an automatic biochemical analyzer, and blood glucose was measured using a Glucoval Compact meter. Expression of proteins related to the insulin signaling pathway in the renal cortex of mice was measured by Western blot analysis.

RESULTS

Diabetic mice developed high blood glucose, BUN and SCr levels compared with control mice. The new oxovanadium complex with 3,5-dimethyl-pyrazolyl ligand, VO(HB(3,5-Me2pz)3)(3,5-Me2pz)(SCN)(SCNH)2, showed low toxicity and significantly reduced blood glucose, BUN and SCr levels in the diabetic mice. Additionally, p42/p44MAPK and Akt phosphorylation was markedly increased in diabetic mice and was decreased by treatment with the new oxovanadium complex. Caveolin-1 (Cav-1) expression was greatly decreased in diabetic mice and significantly increased after treatment with the new oxovanadium complex.

CONCLUSIONS

The new oxovanadium complex, with 3,5-dimethyl-pyrazolyl ligand, improves kidney function in diabetic mice, and its mechanism may involve regulation of the insulin signaling pathway.

Ligation-assisted endoscopic enucleation for treatment of esophageal subepithelial lesions originating from the muscularis propria: a preliminary study

An innovative ligation-assisted endoscopic enucleation (EE-L) technique was developed for the diagnosis and treatment of esophageal subepithelial lesions (smaller than 12 mm) originating from muscularis propria by combining endoscopic band ligation and endoscopic enucleation techniques. The aim of the study was to evaluate efficacy and safety of EE-L technique in the treatment of esophageal subepithelial lesions (smaller than 12 mm) originating from muscularis propria. Forty-seven esophageal subepithelial lesions (smaller than 12 mm) originating from the muscularis propria in 44 patients were treated with EE-L between September 2010 and September 2012. The lesion was first aspirated into the transparent cap attached to the tip of endoscope. The elastic band was then released around its base. The purpose of ligation was to force the lesion to assume a polypoid form with a pseudostalk. Endoscopic enucleation was then performed until the tumor was completely enucleated from muscularis propria using a hook knife and forceps. All tumors (median diameter: 8.2 ± 2.3 mm, range: 4-12 mm) were enucleated completely. Histopathology identified 45 tumors (95.7%) as leiomyoma, 2 (4.3%) tumors as gastrointestinal stromal tumor with very low risk. The mean time of the EE-L procedure was 12.5 ± 4.6 minutes (range: 6-23 minutes). Two patients experienced self-limiting, non-life-threatening hemorrhage after EE-L. No perforation and massive hemorrhage requiring further endoscopic or surgical intervention occurred. There were no recurrences during the 6-24 months follow-up period. EE-L offers the option of localized treatment of small esophageal muscularis propria tumors (smaller than 12 mm) with relatively few complications and low mortality, and provides the advantage of allowing a histopathological diagnosis. All the resected lesions in this study had a benign pathology.

Fibrous hyperplasia involving the orifice of Stensen's duct

This study aimed to describe the clinical features and surgical management of fibrous hyperplasia involving the orifice of Stensen's duct. The clinical data of three patients (one male and two females) were collected and analyzed to characterize this lesion. The lesions surrounding the orifice of Stensen's duct were painless and without obvious causes. The patients' clinical features included sensation of a foreign body and an awkward bite during mastication. All patients received surgical management to resect the polyp and reconstruct the orifice of Stensen's duct. The ducts were preserved intact and parotid glands functioned normally after 12-18 months follow-up. In conclusion, the key point for surgical management of fibrous hyperplasia involving Stensen's duct is to keep the duct intact and unobstructed in consideration of its particular location.

Dual-specificity phosphatase 26 is a novel p53 phosphatase and inhibits p53 tumor suppressor functions in human neuroblastoma

Chemoresistance is a major cause of treatment failure and poor outcome in neuroblastoma. In this study, we investigated the expression and function of dual-specificity phosphatase 26 (DUSP26), also known as mitogen-activated protein kinase phophatase-8, in human neuroblastoma. We found that DUSP26 was expressed in a majority of neuroblastoma cell lines and tissue specimens. Importantly, we found that DUSP26 promotes the resistance of human neuroblastoma to doxorubicin-induced apoptosis by acting as a p53 phosphatase to downregulate p53 tumor suppressor function in neuroblastoma cells. Inhibiting DUSP26 expression in the IMR-32 neuroblastoma cell line enhanced doxorubicin-induced p53 phosphorylation at Ser20 and Ser37, p21, Puma, Bax expression as well as apoptosis. In contrast, DUSP26 overexpression in the SK-N-SH cell line inhibited doxorubicin-induced p53 phosphorylation at Ser20 and Ser37, p21, Puma, Bax expression and apoptosis. Using in vitro and in vivo assays, we found that DUSP26 binds to p53 and dephosphorylates p53 at Ser20 and Ser37. In this report, we show that DUSP26 functions as a p53 phosphatase, which suppresses downstream p53 activity in response to genotoxic stress. This suggests that inhibition of this phosphatase may increase neuroblastoma chemosensitivity and DUSP26 is a novel therapeutic target for this aggressive pediatric malignancy.

Endoscopic ultrasound-guided interstitial chemotherapy in the pancreas: results in a canine model

BACKGROUND AND STUDY AIM

Interstitial chemotherapy using surgically implanted, biodegradable polymers has been reported. Our aim in this study was to investigate the feasibility and safety of endoscopic ultrasound- (EUS-) guided interstitial chemotherapy of the pancreas in a canine model.

MATERIALS AND METHODS

A therapeutic 19-gauge needle with a large channel was inserted into the pancreas under EUS guidance. The polymers for sustained intratumoral release of 5-fluorouracil were implanted into the tissue by the needle. After 14 days of clinical observation, the animals were sacrificed and the tissue response to the local chemotherapy was examined.

RESULTS

All the polymers were implanted successfully and no implant migration occurred. Localized tissue fibrous necrosis was achieved in the pancreas, without significant complications. The apoptotic index of the tissue within 1 cm of the focus increased. Biochemical parameters were normal in all the dogs.

CONCLUSIONS

EUS-guided implantation of polymers is a safe, simple, and minimally invasive technique for interstitial chemotherapy in the pancreas.

[Social economical status, behaviors and environment as the risk factors of tuberculosis in Chengdu China]

OBJECTIVE

To study the risk factors of pulmonary tuberculosis in Chengdu, Southwest China.

METHODS

A population-based case-control study was used which included 174 cases selected from 12 communities in Chengdu and 174 controls selected from registered population with normal chest radiograph. Cases were active TB patients which were matched for age, sex with controls, then interviewed by trained interviewers using a standardized questionnaire.

RESULTS

Social economic status measured by education, occupation and income did not show obvions influence to TB; It found that the active smoking, passive smoking, type of cigarettes and alcohol consumption had no significanct effects on TB during logistic regression analysis. The study showed that a person who was smoking and also alcohol intake had a higher risk to get TB (OR = 6.12, 95% CI = 1.15 - 32.49). Significant association was showed in the Dose-Response Analysis (OR = 1.37, 95% CI = 1.30 - 2.30). Crowded living space (OR = 1.14, 95% CI = 1.05 - 1.25), degree of darkness (OR = 2.18, 95% CI = 1.11 - 4.27) and moisture (OR = 4.06, 95% CI = 2.25 - 7.33), poor sanitary (OR = 3.03, 95% CI = 1.22 - 4.44), airpollution of working environment, which were filled with dusts (OR = 2.35, 95% CI = 1.18 - 4.70) and chemical fumes (OR = 5.15, 95% CI = 1.44 - 18.40) were strongly associated with pulmonary tuberculosis. BMI also had strong relationship with TB (OR = 4.72, 95% CI = 2.68 - 8.33).

CONCLUSION

Poor environment and exposure to dust and chemical fume under working condition, low BMI, smoking combining alcohol consumption were the risk factors of adult pulmonary tuberculosis in Chengdu, China.

Involvement of chemokine receptors in breast cancer metastasis

Breast cancer is characterized by a distinct metastatic pattern involving the regional lymph nodes, bone marrow, lung and liver. Tumour cell migration and metastasis share many similarities with leukocyte trafficking, which is critically regulated by chemokines and their receptors. Here we report that the chemokine receptors CXCR4 and CCR7 are highly expressed in human breast cancer cells, malignant breast tumours and metastases. Their respective ligands CXCL12/SDF-1alpha and CCL21/6Ckine exhibit peak levels of expression in organs representing the first destinations of breast cancer metastasis. In breast cancer cells, signalling through CXCR4 or CCR7 mediates actin polymerization and pseudopodia formation, and subsequently induces chemotactic and invasive responses. In vivo, neutralizing the interactions of CXCL12/CXCR4 significantly impairs metastasis of breast cancer cells to regional lymph nodes and lung. Malignant melanoma, which has a similar metastatic pattern as breast cancer but also a high incidence of skin metastases, shows high expression levels of CCR10 in addition to CXCR4 and CCR7. Our findings indicate that chemokines and their receptors have a critical role in determining the metastatic destination of tumour cells.

Involvement of chemokine receptors in breast cancer metastasis

Breast cancer is characterized by a distinct metastatic pattern involving the regional lymph nodes, bone marrow, lung and liver. Tumour cell migration and metastasis share many similarities with leukocyte trafficking, which is critically regulated by chemokines and their receptors. Here we report that the chemokine receptors CXCR4 and CCR7 are highly expressed in human breast cancer cells, malignant breast tumours and metastases. Their respective ligands CXCL12/SDF-1alpha and CCL21/6Ckine exhibit peak levels of expression in organs representing the first destinations of breast cancer metastasis. In breast cancer cells, signalling through CXCR4 or CCR7 mediates actin polymerization and pseudopodia formation, and subsequently induces chemotactic and invasive responses. In vivo, neutralizing the interactions of CXCL12/CXCR4 significantly impairs metastasis of breast cancer cells to regional lymph nodes and lung. Malignant melanoma, which has a similar metastatic pattern as breast cancer but also a high incidence of skin metastases, shows high expression levels of CCR10 in addition to CXCR4 and CCR7. Our findings indicate that chemokines and their receptors have a critical role in determining the metastatic destination of tumour cells.

[Smoking and alcohol consumption as risk factors of pulmonary tuberculosis in Chengdu: a matched case-control study]

OBJECTIVE

The aim of this study was to assess the relationship between personal behaviors (smoking and alcohol consumption) and contracting pulmonary tuberculosis.

METHODS

346 persons (173 cases and 173 controls) were selected from 12 communities of Chengdu area, all the cases were active TB patients (by WHO criteria) from March 1996 to March 1997. Controls were matched for age, sex and living district. Subjects were interviewed face to face by trained interviewers using questionnaires.

RESULTS

The results of univariate analysis showed that active smoking (OR = 2.12, P = 0.006), passive smoking (OR = 1.55, P = 0.04), type of cigarettes (OR = 1.31, P = 0.005) and alcohol consumption (OR = 1.81, P = 0.008) were significantly associated with TB. Yet, multivariate logistic regression analysis did not find smoking or alcohol consumption being in independent association with TB, but it showed that persons who were smokers with the addition of alcohol consumption had a higher risk to contract TB (OR = 7.729, 95% C.I. = 1.5215-39.2634). Significant association was noted in the dose-response analysis (OR = 1.73, 95% C.I. = 1.300-2.3028).

CONCLUSION

These data indicate that smoking alone or sole alcohol consumption bears no relationship with TB, but smoking plus alcohol abuse is probably a risk factor for pulmonary tuberculosis in Chengdu, and in this connection, a proposal of prospective study to further demonstrate this risk factor is warranted.

Interferon-gamma activates outwardly rectifying chloride channels in the human bronchial epithelial cell line BEAS-2B

The mechanism of increased chloride currents by inflammatory cytokine, interferon-gamma (IFN-gamma), was investigated in cultured a human bronchial epithelial cell line (BEAS-2B) using cell-attached and inside-out patch configurations. The channel sensitive to chloride ion was activated by forskolin, an activator of adenylate cyclase, or 100 microM dibutyryl 5'-cyclic monophosphate in cell-attached configurations. The conductance of this channel was 40 +/- 4 pS in symmetrical 150 mM chloride solution between membrane potentials of 0 to mV, and this channel was blocked by 500 microM 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), suggesting that this channel was an outwardly rectifying chloride channel (ORCC). Treatment of 10-1000 U/ml IFN-gamma for 3 hours, but not IFN-alpha, significantly increased channel activities of ORCC, and this activation was observed at least 24 hours after treatment. Erythromycin, a macrolide antibiotic, at a concentration of 100 microM inhibited the activation of ORCC induced by IFN-gamma. The findings of the present study indicate that increased mucus secretion during inflammation might be partly due to activation of chloride permeability by cytokine and erythromycin might improve oversecretion of mucus from bronchial epithelium by blocking ORCC.

Theoretical elucidation of activity differences of five phenolic antioxidants

AIM

To verify the effectiveness of structure-activity relationship (SAR) and theoretical calculation methods for antioxidants.

METHODS

Preliminary elucidation on the differences of activities of 5 antioxidants was performed by SAR. Then semiempirical quantum chemistry method AM1 was employed to calculate the delta HOF value, the difference between the heat of formation of antioxidant and its free radical, which was used as a theoretical parameter to elucidate the differences of activities of the antioxidants thoroughly.

RESULTS

delta HOF values of antioxidants were obtained as follows: ferulic acid, 150.58 kJ.mol-1; anion of ferulic acid, 122.64 kJ.mol-1; modified ferulic acid, 137.70 kJ.mol-1; anion of modified ferulic acid, 118.99 kJ.mol-1; salvianic acid, 134.17 kJ.mol-1; rutin, 137.83 kJ.mol-1, L-EGCG, 124.39 kJ.mol-1; paeonol, 176.79 kJ.mol-1. The differences of the antioxidant activities were elucidated, and how to further enhance the antioxidant activity was investigated as well.

CONCLUSION

The SAR and calculation methods are rather effective to elucidate the differences of antioxidant activities, and present some new clues for structural modification of antioxidants to increase their activities.

Step-down trend tests for identifying the minimum effective dose

Many authors, most recently Tamhane, Hochberg, and Dunnett (18), have studied the problem of determining the minimum effective dose in dose-response studies. Based on past research and on findings from their own extensive simulation study, which covered a wide range of balanced normal homoscedastic situations, Tamhane et al. recommended a procedure they called SD2L, since it exhibited good performance in almost all the situations they studied. This method is a step-down procedure with a simple linear contrast-based trend test at each step. In this paper, we demonstrate that replacing the linear contrast trend test by Bartholomew's test leads to a procedure, SD2B, that consistently outperforms SD2L. In addition to the balanced normal homoscedastic framework, the finite sample performance of these procedures is also explored under unbalanced and/or heteroscedastic conditions. A third procedure, SD2W, which replaces the linear contrast test by Welch's test, offers some improvement over SD2B in a few heteroscedastic situations. In many cases, the increase in efficiency of SD2B and SD2W over SD2L exceeds 10%.

Femtosecond dynamics of electron localization at interfaces

The dynamics of two-dimensional small-polaron formation at ultrathin alkane layers on a silver(111) surface have been studied with femtosecond time- and angle-resolved two-photon photoemission spectroscopy. Optical excitation creates interfacial electrons in quasi-free states for motion parallel to the interface. These initially delocalized electrons self-trap as small polarons in a localized state within a few hundred femtoseconds. The localized electrons then decay back to the metal within picoseconds by tunneling through the adlayer potential barrier. The energy dependence of the self-trapping rate has been measured and modeled with a theory analogous to electron transfer theory. This analysis determines the inter- and intramolecular vibrational modes of the overlayer responsible for self-trapping as well as the relaxation energy of the overlayer molecular lattice. These results for a model interface contribute to the fundamental picture of electron behavior in weakly bonded solids and can lead to better understanding of carrier dynamics in many different systems, including organic light-emitting diodes.

Pathogenesis of HIV-1 associated neurodegeneration

A significant number of people infected with the human immunodeficiency virus (HIV) develop neurologic complications. The AIDS dementia complex is frequently accompanied by HIV encephalitis, which is characterized at the neuropathologic level by loss of neuronal subpopulations in the neocortex, limbic system, and basal ganglia in association with synaptic and dendritic damage, astrogliosis, and formation of microglial nodules and multinucleated giant cells. Recent studies have shown that the extent of neurodegeneration in this condition correlates directly with the amount of HIV-1 antigen in the brain. HIV-1 infection of the brain could result in neurodegeneration via neurotoxic effects of viral products (e.g., gp 120, Nef, Tat) and/or via alterations in the expression of host factors. The latter may include increased production of potentially detrimental factors such as cytokines, excitotoxic amino acids, free oxygen radicals, and bioactive lipid mediators as well as interference with the production or action of neurotrophic/protective factors. Derangements of the neuronal calcium homeostasis, lipid peroxidation, and induction of programmed cell death (apoptosis) may all play a role as final common pathogenetic pathways in HIV-1-induced neurodegeneration. Recent studies in transgenic mice (over)expressing HIV- or host-derived proteins in their central nervous system indicate that distinct neuronal populations may differ in their susceptibility to specific pathogenic factors. For example, glutamate-receptor-bearing pyramidal neurons were particularly susceptible to neurodegeneration promoted by HIV-1 products, whereas interneurons were more sensitive to the neurotoxic effects mediated by cytokines. For the design of effective treatments for the HIV-1-associated cognitive/motor complex, it will be important to determine whether the neurologic deficits in this entity result from global neuronal dysfunction or relate more specifically to the impairment of distinct neuronal subpopulations. It will also be critical to examine diverse in vitro and in vivo models to help decide which of the many pathogenetic processes that may be at work in this complex disease constitute the most promising therapeutic targets.

Neurodegeneration in the central nervous system of apoE-deficient mice

Apolipoprotein E (apoE) is involved in the development and regeneration of the central nervous system (CNS). ApoE may also be necessary to maintain the integrity of the synapto-dendritic complexity. We analyzed the synaptic alterations in the CNS of apoE-deficient (knockout) mice during the aging process. In apoE-deficient homozygous mice, there was an age-dependent 15 to 40% loss of synaptophysin-immunoreactive nerve terminals and microtubule-associated protein 2-immunoreactive dendrites in the neocortex and hippocampus, when compared to controls. Dendritic alterations were observed as early as 4 months of age. Ultrastructural analysis revealed extensive dendritic vacuolization and disruption of the endomembrane system and cytoskeleton in apoE-deficient homozygous mice. Further immunocytochemical studies of the neuronal cytoskeleton showed that in apoE-deficient mice there was a decrease in the immunoreactivity of alpha and beta tubulin (but not kinesin) in the cell bodies and processes. These results support the contention that apoE might play an important role in maintaining the stability of the synapto-dendritic apparatus and that altered or deficient functioning of this molecule could underlie the synaptic and cytoskeletal alterations in Alzheimer's disease.

The inhibitory effect of apolipoprotein E4 on neurite outgrowth is associated with microtubule depolymerization

Evidence is presented for the differential effects of two isoforms of apolipoprotein (apo) E, apoE3 and apoE4, on neurite outgrowth and on the cytoskeleton of neuronal cells (Neuro-2a) in culture. In the presence of a lipid source, apoE3 enhances and apoE4 inhibits neurite outgrowth. Immunocytochemical studies demonstrate that there is a higher concentration of apoE3 than apoE4 in both the cell bodies and neurites. Cells treated with apoE4 showed fewer microtubules and a greatly reduced ratio of polymerized to monomeric tubulin than did cells treated with apoE3. The effect of apoE4 on depolymerization of microtubules was shown by biochemical, immunocytochemical, and ultrastructural studies. The depolymerization of microtubules and the inhibition of neurite outgrowth associated with apoE4 suggest a mechanism whereby apoE4, which has been linked to the pathogenesis of Alzheimer's disease, may prevent normal neuronal remodeling from occurring later in life, when this neurodegenerative disorder develops.

Differential vulnerability of calbindin-immunoreactive neurons in HIV encephalitis

Recent studies have suggested that the neuronal damage during human immunodeficiency virus encephalitis (HIVE) might be mediated by increased intracellular calcium. Since in vitro studies have shown that calcium-binding proteins protect neurons from calcium-mediated toxicity, we hypothesized that calbindin-expressing neurons might be resistant to HIV1-mediated damage. We compared patterns of calbindin immunoreactivity in the cortex and subcortex of autopsied AIDS cases with and without HIVE. Calbindin-immunoreactive neurons in the neocortex were significantly reduced in HIVE (one-way ANOVA, p < 0.001), while these neurons in the basal ganglia and hippocampus were unaffected. The loss of calbindin-immunolabeled neurons in the neocortex was correlated with viral burden (r = -0.45, p < 0.001). Differential loss of calbindin-immunoreactive neurons in HIVE suggests that neuronal damage in different regions of the CNS may be mediated by different pathogenic mechanisms.

Fragmentation of the neuronal cytoskeleton in the Lewy body variant of Alzheimer's disease

We studied neuronal alterations in the Lewy body variant of Alzheimer's disease (LBV) with a monoclonal antibody (SMI32) against non-phosphorylated neurofilament proteins, and compared them with the alterations found in pure Alzheimer's disease (AD). A characteristic granular and fragmented appearance of SMI32-immunolabeled pyramidal neurons in layers 3 and 5 of the neocortex occurred in 78% of the LBV cases and was not found in the pure AD cases. Lewy bodies (LBs) in pyramidal neurons in layers 5 and 6 immunoreacted with SMI32 in 44% of the LBV cases. These alterations may be associated with the cognitive deficits found in LBV and are suggestive of an underlying, widespread pathology that includes both disruption of the neurofilamentous cytoskeleton and formation of LBs.

The precursor protein of non-A beta component of Alzheimer's disease amyloid is a presynaptic protein of the central nervous system

Non-A beta component of Alzheimer's disease amyloid (NAC) is the second component in the amyloid from brain tissue of patients affected with Alzheimer's disease. Its precursor protein (NACP) was shown to be a brain-specific protein. In rat brain, NACP was more abundant in the neocortex, hippocampus, olfactory bulb, striatum, thalamus, and cerebellum and less abundant in the brain stem. Confocal laser microscopy analysis revealed that anti-NACP immunostaining was colocalized with synaptophysin-immunoreactive presynaptic terminals. Ultrastructural analysis showed that NACP immunoreactivity was associated with synaptic vesicles. NACP sequence showed 95% identity with that of rat synuclein 1, a synaptic/nuclear protein previously identified in rat brain, and good homology with Torpedo synuclein from the electric organ synapse and bovine phosphoneuroprotein 14 (PNP-14), a brain-specific protein present in synapses. Therefore, NACP is a synaptic protein, suggesting that synaptic aberration observed in senile plaques might be involved in amyloidogenesis in Alzheimer's disease.

Cytokine receptor alterations during HIV infection in the human central nervous system

Cytokines are potent factors mediating interactions between the immune and nervous systems. Cytokines released by macrophages/microglia, the predominant immune cell within the brain, have been proposed to modulate neuronal survival and death. In human immunodeficiency virus-encephalitis (HIVE), cytokines could modulate neurologic damage if nervous system cells possessed appropriate receptors. We hypothesized that the populations of neurons vulnerable to the toxic effects of cytokines in HIVE might contain specific receptors for these molecules. We examined the distribution of cytokine receptors in the human brain utilizing fluorescent-labeled cytokines combined with confocal laser microscopy imaging. Phycoerythrin-conjugated interleukin-1 beta and phycoerythrin-Avidin/biotin conjugated transforming growth factor beta 1 labeled dendritic processes of neurons in the neocortex. Labeling was abolished by pre-incubation with unlabeled cytokines. In cases with moderate HIVE, an average 35% increase in intensity of labeling was observed compared to cases without HIVE or with cases with severe HIVE. The patterns of interleukin 2 labeling were not altered in HIVE. These results suggest that neurons susceptible to cytokine-mediated damage during the progression of HIVE display abnormal patterns of cytokine receptor labeling.

Phorbol ester-induced neuritic alterations in the rat neocortex. Structural and immunocytochemical studies

In order to explore the effect of aberrant sprouting in the CNS, phorbol 12-myristate 13-acetate (PMA) was administered into the neocortex of adult rats. PMA is a growth-promoting agent that activates and eventually downregulates protein kinase C (PKC), and induces in the rat the expression of several genes, including amyloid precursor protein (APP). We found that multiple injections of 100 nM PMA into the rat neocortex promote, in the first week postinjection, a widespread vacuolization of the neuropil with a subsequent disruption of the synapses in the injection site, followed, at d 15, by the formation of abnormally distended clusters of neurites that resembled aberrant, sprouting axons. At d 30, fewer aberrant sprouts were observed, and many degenerating neurites were found. At the ultrastructural level, the PMA-induced abnormal neurites at d 7-15 resembled growth cones, whereas the dystrophic neurites at d 30 contained abundant dense and laminated bodies. Immunohistochemical analysis indicated that the abnormal neurites in the areas of denervation and PMA administration were positive with antisynaptophysin and antigrowth-associated protein 43 (GAP-43), with an increased APP immunoreactivity surrounding them. APP immunoreactivity around the injection site was mostly associated with pyramidal neurons and glial cells. Control experiments, where saline alone or 4 alpha-phorbol 12, 13-didecanoate (PDD, an inactive phorbol derivative) was injected, failed to show aberrant sprouting neurites. Further immunohistochemical analysis showed that the PMA-treated animals presented increased amyloid beta immunoreactivity in the pyramidal cells at the site of injection, when compared with control injections. These findings suggest that aberrant sprouting induced by overstimulation could be followed by neurodegeneration. Alternatively, PKC downregulation could directly induce the neurodegeneration, with a secondary sprouting response.