[Efficacy and safety of low-dose rasburicase for refractory chronic gouty arthritis]

Objective: To explore the efficacy and safety of low-dose rasburicase for refractory chronic gouty arthritis. Methods: A cohort study. The clinical data of patients with refractory chronic gouty arthritis who were treated with rasburicase at Sun Yat-sen Memorial Hospital, Sun Yat-sen University between January 2021 and July 2022 were retrospectively analyzed. Refractory chronic gouty arthritis was defined as serum uric acid (sUA)>360 μmol/L and urate volume>10 cm³ under dual-energy computed tomography after tolerable maximal oral urate-lowering therapy for at least 3 months. The administration of low-dose rasburicase was applied intravenously with total dosage ranging from 4.5 to 7.5 mg each dose, at 4-week intervals for a maximum of three doses. Efficacy was evaluated by the changes of sUA level, tophus and urate volume. Results: A total of 22 patients were included for analysis, with 95.4% (21/22) male, the mean age was (44±15) years, and the median duration of gout was 11 (6-15) years. The mean sUA at baseline was (667±112) μmol/L. The levels of sUA significantly decreased after each dose of rasburicase (P<0.001), and the median reduction of sUA after each dose of rasburicase was 568 (471-635), 187 (66-335) and 123 (49-207) μmol/L, respectively. At week 12, nine patients (40.9%) exhibited sUA<360 μmol/L and tophus disappeared in one patient. The urate volume significantly decreased at week 12 when compared with that before the first dose of rasburicase in all the patients [40 (16-172) cm³ vs 17 (7-134) cm³, P<0.001], with a median reduction rate of 41.6% (22.9%-58.5%). The everall safety of rasburicase was good, and no serious adverse reactions occurred. Conclusions: Low-dose rasburicase is well-tolerated and effective for decreasing the urate burden in patients with refractory chronic gouty arthritis. Further prospective randomized controlled trials are needed to validate these findings.

[Predictive performance for prognosis of aneurysmal subarachnoid hemorrhage with ventricular hemorrhage by imaging combined with clinical and laboratory quantitative index model]

Objective: To explore the predictive performance of image quantitative index model, clinical-laboratory index model and image-clinical multi-dimensional fusion model in predicting the prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH) with intraventricular hemorrhage (IVH). Methods: A total of 349 patients with aSAH and IVH, including 122 males and 227 females, aged 22 to 85 (59±11) years underwent CT scan in the General Hospital of Eastern Theater Command from January 2010 to December 2019 were used as dataset 1 to construct a prognostic model. A prognostic model was constructed for data set 1, and the functional recovery of patients 12 months after discharge was evaluated using the modified Rankin Scale (mRS). According to the results, those patients were divided into two groups: good outcome group (n=267) and poor outcome group (n=82). In addition, 63 aSAH patients with IVH, including 27 males and 36 females, aged 32 to 87 (61±12) years who were admitted to the General Hospital of Eastern Theater Command from January 2020 to December 2021 were collected as dataset 2 for independent verification of the model, including 30 patients with poor prognosis. Clinical information (age and gender), laboratory indicators (blood routine and blood biochemistry), and imaging quantitative indicators (such as volume, density, shape of each ventricle hemorrhage area outlined and extracted on head CT scan etc.) were recorded for all patients (dataset 1 and 2). The clinical, laboratory and imaging quantitative indicators of dataset 1 were screened by using L1 regularization and multiple logistic regression method was used to construct the clinical-laboratory index model, image quantitative index model and image-clinical multi-dimensional fusion model, according to the weight coefficient of features in the clinical-laboratory index model and image quantitative index model, screen out the main features. The model was trained and internally validated by 5-fold cross-validation. The model was validated independently in dataset 2. Results: The AUC (area under the ROC curve) of clinical-laboratory index model, image quantitative index model and multidimensional fusion model constructed based on dataset 1 were 0.75 (95%CI: 0.69-0.81), 0.68 (95%CI: 0.61-0.74) and 0.86 (95%CI: 0.82-0.91). The Delong test showed that there were statistically significant differences between the performance of the multi-dimensional fusion model and the clinical-laboratory index model or image quantitative index model (all P<0.05). The AUC of clinical-laboratory index model, image quantitative index model and multidimensional fusion model of dataset 2 were 0.79 (95%CI: 0.68-0.91), 0.70 (95%CI: 0.57-0.83) and 0.81 (95%CI: 0.70-0.92). In addition, in the clinical-laboratory index model and imaging quantitative index model constructed based on data 1, age, Hunt-Hess grade on admission, Neutrophil/Lymphocyte (N/L) (the weight coefficients in the clinical-laboratory index model were 1.00, -0.59 and 0.44) and the standard deviation of third ventricle hemorrhage density, minimum hemorrhage density of the fourth ventricle, and left ventricle hemorrhage sphericity (the weight coefficients in the image quantitative index model were -1.00, 0.85 and -0.84) were the main features of the screening. Conclusions: Quantitative imaging indicators of ventricular hemorrhage (standard deviation of third ventricular hemorrhage density, minimum density of fourth ventricular hemorrhage, and left ventricular sphericity) are helpful to predict the poor prognosis of patients with aSAH with ventricular hemorrhage. Dimensional fusion model has greater value in predicting poor prognosis of patients.

Baicalein ameliorates ulcerative colitis by improving intestinal epithelial barrier via AhR/IL-22 pathway in ILC3s

Ulcerative colitis (UC) is a chronic inflammatory disease of the gastrointestinal tract, which is closely related to gut barrier dysfunction. Emerging evidence shows that interleukin-22 (IL-22) derived from group 3 innate lymphoid cells (ILC3s) confers benefits on intestinal barrier, and IL-22 expression is controlled by aryl hydrocarbon receptor (AhR). Previous studies show that baicalein protects the colon from inflammatory damage. In this study we elucidated the molecular mechanisms underlying the protective effect of baicalein on intestinal barrier function in colitis mice. Mice were administered baicalein (10, 20, 40 mg·kg-1·d-1, i.g.) for 10 days; the mice freely drank 3% dextran sulfate sodium (DSS) on D1-D7 to induce colitis. We showed that baicalein administration simultaneously ameliorated gut inflammation, decreased intestinal permeability, restored tight junctions of colons possibly via promoting AhR/IL-22 pathway. Co-administration of AhR antagonist CH223191 (10 mg/kg, i.p.) partially blocked the therapeutic effects of baicalein in colitis mice, whereas AhR agonist FICZ (1 μg, i.p.) ameliorated symptoms and gut barrier function in colitis mice. In a murine lymphocyte line MNK-3, baicalein (5-20 μM) dose-dependently increased the expression of AhR downstream target protein CYP1A1, and enhanced IL-22 production through facilitating AhR nuclear translocation, these effects were greatly diminished in shAhR-MNK3 cells, suggesting that baicalein induced IL-22 production in AhR-dependent manner. To further clarify that, we constructed an in vitro system consisting of MNK-3 and Caco-2 cells, in which MNK-3 cell supernatant treated with baicalein could decrease FITC-dextran permeability and promoted the expression of tight junction proteins ZO-1 and occluding in Caco-2 cells. In conclusion, this study demonstrates that baicalein ameliorates colitis by improving intestinal epithelial barrier via AhR/IL-22 pathway in ILC3s, thus providing a potential therapy for UC.

[Comparison on the clinical characteristics of patients with Takotsubo syndrome from China and from Europe/North America]

Objective: To summarize the clinical characteristics of patients with Takotsubo syndrome (TTS) from China and compare these features with patients from Europe/North America. Methods: We reviewed case reports published between 1990 and 2020 with the key words of "Takotsubo syndrome" "stress cardiomyopathy" "apical balloon syndrome" and "broken heart syndrome", in Wanfang, CNKI, Pubmed and Web of Science databases, and 1 294 articles were identified, including 128 articles reporting 163 cases in China and 1 166 articles reporting 1 256 cases in Europe/North America. The characteristics of demographics, triggers, symptoms, electrocardiogram, echocardiography, left ventriculogram,coronary angiography, treatment and prognosis were analyzed and compared between Chinese and European/North American cases. Results: A total of 1 294 articles (1 419 cases: 163 from China, 1 256 from Europe/North America) were included in the final analysis. The characteristics of Chinese cases included: (1) demographic:the age was (59.6±16.9) years, which was similar with that of European/North American ((59.7±17.4) years, P=0.90), and female accounting for 78.5% (128/163), which was lower than that of European/North American (85.4% (1 073/1 256), P=0.02). (2) Triggers:mental triggers accounted for 48.5% (79/163), physical triggers accounted for 43.6% (71/163), and no triggers accounted for 7.9% (13/163), respectively. Compared with Europe/North America, the ratio of patients with mental triggers was higher in China, while the ratio of patients with physical triggers and no triggers was lower (P<0.05). (3) Symptoms: chest pain (52.8% (86/163)), chest tightness (35.0% (57/163)), shortness of breath (33.1% (54/163)), dizziness (16.0% (26/163)), sweating (15.3% (25/163)), palpitations (12.3% (20/163)), syncope (9.2% (15/163)) abdominal pain/diarrhea (8.6% (14/163)), hypotension (7.4% (12/163)), and fatigue (1.2% (2/163)) were illustrated in sequence. Compared with patients in Europe/North America, the ratio of patients with chest tightness, dizziness, sweating, palpitations, abdominal pain/diarrhea was higher in Chinese patients, while the ratio of patients with hypotension was lower in Chinese patients (P<0.05). (4) Electrocardiogram: main manifestations were myocardial ischemia symptoms, such as ST-segment elevation (63.8% (104/163)), T wave inversion (46.0% (75/163)), ST-segment depression (8.6% (14/163)). Compared with European/North American, the ratio of patients with ST-segment elevation, T wave inversion, and atrioventricular block was higher in Chinese patients (P<0.05). (5) Echocardiography and imaging:apical dyskinesia (59.5% (97/163)) and apical/left ventricular bulbar dilation (36.2%(59/163)) dominated the echocardiography findings. Compared with European/North American, the ratio of patients with apical dyskinesia, apical/left ventricular bulbar dilation, and mitral regurgitation was higher in Chinese patients, while the ratio of patients with dyskinesia in other parts and left ventricular ejection fraction<50% was lower in Chinese patients (P<0.05). Left ventricular angiography showed 36.2% (59/163) of apical dyskinesia in Chinese patients, which was higher than that reported in European/North American patients, and 38.7% (63/163) of apical/left ventricular bulbar dilation was reported in Chinese patients, which was similar to that reported in European/North American patients. Coronary angiography showed percent of no stenosis or stenosis less than 50% was 87.1% (142/163), which was similar to that reported in European/North American patients (P>0.05). The typical type of TTS accounted for 96.3% (157/163), which was significantly higher than that reported in European/ American patients, while the ratio of basal type and midventricular type was lower (P<0.01). (6) Treatment and prognosis:the applied drugs in China were listed in order as following, β-blockers (41.1% (67/163)), antiplatelet agents (37.4%(61/163)), ACEI/ARB (36.2%(59/163)), anticoagulants (27.0%(44/163)), diuretics (19.6% (32/163)), etc. Compared with Europe/North America, the ratio of antiplatelet agents, anticoagulants, statins, diuretics, and nitrates use was higher in China (P<0.05), while the use of oxygen therapy and IABP was similar (P>0.05). The hospital mortality in China was 5.5% (9/163), during 1-year follow-up the recurrence rate was 3.7% (6/163) and the mortality was 0. The prognosis was similar with that in Europe/North America. Conclusions: Compared with TTS cases in Europe/North America, TTS cases in China also occur usually in middle-aged and elderly women, most of whom have mental/physical triggers and typical imaging manifestations, followed by a low hospital mortality rate and recurrence rate.

Actinostephanus (Gesneriaceae), a new genus and species from Guangdong, South China

Actinostephanus, a new genus from southern China, is described and colorfully illustrated with a single species, A.enpingensis. This new genus is morphologically most similar to Boeica and Leptoboea, nevertheless, it can be easily distinguished from the latter two by the following characteristics, such as leaves in whorls of three, all closely clustered at the top; corolla bowl-shaped, 5-lobed, actinomorphic; capsule hard, oblong-ovoid, short, 3-4 mm long, densely appressed villous, wrapped by persistent densely pubescent calyx lobes, style persistent. The new genus and related genera were sequenced using the next-generation sequencing technique. The whole plastid genome of the new genus is 154, 315 - 154, 344 bp in length. We reconstructed phylogenetic trees using the dataset of 80 encoded protein genes of the whole plastid genome from 47 accessions based on ML and BI analyses. The result revealed that the new genus was recovering in a polytomy including Boeica, Rhynchotechum, and Leptoboea with strong support, congruent to the morphological evidence. A global conservation assessment was also performed and classifies A.enpingensis as Least Concern (LC). In addition, after a review of recently described species of Gesneriaceae, we propose that plant enthusiasts, especially Gesneriad fans, have been playing an increasingly important role in the process of new taxa-discoveries.

Dynamic biomechanical effect of lower body positive pressure treadmill training for hemiplegic gait rehabilitation after stroke: A case report

BACKGROUND

Lower body positive pressure (LBPP) treadmill has potential applications for improving the gait of patients after stroke, but the related mechanism remains unclear.

CASE SUMMARY

A 62-year-old male patient suffered from ischemic stroke with hemiplegic gait. He was referred to our hospital because of a complaint of left limb weakness for 2 years. The LBPP training was performed one session per day and six times per week for 2 wk. The dynamic plantar pressure analysis was taken every 2 d. Meanwhile, three-digital gait analysis and synchronous electromyography as well as clinical assessments were taken before and after LBPP intervention and at the 4-wk follow-up. During LBPP training, our patient not only improved his lower limb muscle strength and walking speed, but more importantly, the symmetry index of various biomechanical indicators improved. Moreover, the patient’s planter pressure transferring from the heel area to toe area among the LBPP training process and the symmetry of lower body biomechanical parameters improved.

CONCLUSION

In this study, we documented a dynamic improvement of gait performance in a stroke patient under LBPP training, which included lower limb muscle strength, walking speed, and symmetry of lower limb biomechanics. Our study provides some crucial clues about the potential dynamic mechanism for LBPP training on gait and balance improvement, which is related to rebuilding foot pressure distribution and remodeling symmetry of biomechanics of the lower limb.

[Potential mechanism of transcription factor peroxisome proliferator-activated receptor-gamma coactivator-1 beta on promoting osteoclastogenesis]

Objective: To investigate the role of transcription factor peroxisome proliferator-activated receptor-gamma coactivator-1 beta (PGC-1β) on osteoclastogenesis and related regulatory mechanism in the mouse monocyte-macrophage cell line (RAW264.7). Methods: PGC-1β expression and location in RAW264.7 cells was detected by immunofluorescence, flow cytometry and western blot analysis with nuclear protein extraction. RAW264.7 cells were transfected with lentivirus for gene silencing or over-expression of PGC-1β and cultured with macrophage colony-stimulating factor and receptor activator for nuclear factor-κB ligand. Cell viability was detected by cell counting kit-8. Cell apoptosis and cell cycle were detected by flow cytometry. Mature osteoclasts and their bone resorption activity were determined by tartrate-resistant acid phosphatase (TRAP) expression and toluidine blue staining. Western blot analysis was performed for detecting dendritic cell-specific transmembrane protein (DC-STAMP), cathepsin K, TRAP and matrix metalloproteinase (MMP)-9 expression, as well as cytoplasmic NF-κB-inducing kinase (NIK) and nuclear RelB. Results: PGC-1β expression was observed in the nuclei of RAW264.7 cells. Down-regulation or overexpression of PGC-1β in RAW264.7 cells did not affect cell viability, apoptosis or cell cycle. Down-regulation of PGC-1β decreased the count of mature osteoclasts (49±21 cells vs. 147±42 cells, P=0.004) and the pit area of bone resorption lacunae (42.11μm(2)±11.30 μm(2) vs. 204.80μm(2)±31.09 μm(2), P<0.001), as well as the expression of cathepsin K, TRAP and MMP-9, but not DC-STAMP. Overexpression of PGC-1β promoted osteoclast differentiation and bone resorption activity, as well as the expression of cathepsin K, TRAP and MMP-9. Down-regulation of PGC-1β suppressed the protein expression of cytoplasmic NIK and nuclear RelB in RAW264.7 cells. Conclusion: PGC-1β can promote the differentiation of RAW264.7 into osteoclasts and improve the bone resorption ability of the cells via activation of NIK/RelB pathway, which might be a promising therapeutic target for osteoporosis.

[Characteristics and clinical significance of body composition in gout patients]

Objective: To investigate the characteristics of body composition (BC) in gout patients and its clinical significance. Methods: Consecutive gout patients were recruited between August 2017 and December 2018. Demographic information, clinical characteristics and comorbidities were collected. BC was assessed by bioelectric impedance analysis including body fat percentage (BF%), trunk and limb BF%, appendicular skeletal muscle index. Overfat was defined by BF% ≥25% for male and ≥35% for female. The association between BC and serum uric acid (sUA) was evaluated by multiple linear regression. Results: A total of 362 gout patients were recruited with median age 38 (30, 52) years, 96.1% (348/362) were male. Mean sUA was (551±133) μmol/L. The mean BF% was (25.8±6.4)% with 53.6%(194/362) patients overfat. Male gout patients with overfat showed more affected joints [4(2, 6) vs. 2(2, 5)], higher sUA [(576±126)μmol/L vs. (523±134) μmol/L], higher prevalence of dyslipidemia [70.1%(131/187) vs. 54.0%(87/161)], metabolic syndrome [60.8%(118/187) vs. 28.0%(47/161)], fatty liver [58.2%(113/187) vs. 35.1%(59/161)] and hypertension [44.4%(83/187) vs. 25.5%(41/161)] than male patients with normal fat (all P<0.05). Their BF%, trunk BF% and limb BF% were positively correlated with the numbers of affected joints, sUA, metabolic syndrome, fatty liver, and hypertension, respectively (r=0.154-0.435, all P<0.05). Multivariable linear regression suggested that BF% (β=4.29, P=0.020) and trunk BF% (β=9.11, P=0.007), but not limb BF%, were positively correlated with sUA. Conclusion: Overfat is very common in gout patients. The proportion of trunk fat in male patients is positively correlated with sUA. When assessing obesity in gout patients clinically, body composition analysis should be performed simultaneously.

[Influence of antiretroviral prophylaxis on growth of HIV-exposed uninfected infants]

Objective: To evaluate the influence of antiretroviral prophylaxis on the growth and development of HIV-exposed uninfected infants in Guangzhou. Methods: Data were from the national information system for prevention of mother-to-child transmission of HIV infection, syphilis and hepatitis B. After excluding death and perinatal HIV infection cases, 564 HIV-exposed uninfected infants were included. The infants were divided into three groups, nevirapine (NVP) group, zidovudine (AZT) group and untreated group. The influences of antiretroviral prophylaxis on the body weight and height of the HIV-exposed uninfected infants were analyzed by using generalized estimating equations. Results: The HIV-exposed uninfected infants at 1-month old had lower Z scores of body weight-for-age and body height-for-age than the World Health Organization's reference standard. The prevalence of wasting in AZT group (17.5%) was higher than that in NVP group (6.2%) for 1-month old infants. Taking NVP or AZT was a protective factor for Z score of body length-for-age (P<0.05). Intrauterine exposure to triple antiviral drugs was a risk factor for the Z scores of body weight-for-age and body length-for-age (P<0.05). Conclusion: The physical growth and development of HIV-exposed uninfected infants at 1-month old was not well, and HIV-exposed uninfected infants who taking AZT had a higher incidence of wasting. Attention should be paid to these infants.

[Association between both maternal pre-pregnancy body mass index/gestational weight gain and overweight/obesity children at preschool stage]

Objective: To investigate the association of both maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) with childhood overweight and adiposity in preschool children. Methods: A total of 4 303 preschool children aged 3-5 years were enrolled in our study during June and November 2016 in Guangzhou. Children defined as overweight and obesity were according to the criteria of WHO while weight status during maternal pre-pregnancy was using the China Adult Reference. Gestational weight gain was defined according to the Institute of Medicine guidelines. Results: After adjusting the possible confounding factors, results from the logistic regression analysis showed that both maternal pre-pregnancy overweight and obesity would increase the risk for both childhood overweight and obesity (OR=1.820, 95%CI: 1.368-2.422). The analysis of covariance results also showed that both maternal overweight and obesity before pregnancy and excessive maternal weight gain during pregnancy increased the BMI Z-score in children. Maternal GWG over the recommended level were associated with both the childhood overweight and obesity (OR=1.296, 95%CI: 1.007-1.667). Joint associations of pre-pregnancy BMI and inappropriate GWG were also noticed in the study. Stratified analysis was conducted in three groups according to the pre-pregnancy BMI of the mothers. Result showed that there was no statistical difference in the risks of either overweight or obesity in children (P>0.05). However, when compared to mothers with adequate pre-pregnancy higher BMI and adequate GWG, under the combination of high pre-pregnancy BMI and excessive GWG, their adverse effects on childhood overweight and obesity were much higher (OR=1.574, 95%CI: 1.029-2.409). Conclusions: Both high pre-pregnancy BMI and inappropriate GWG were associated with greater BMI of their offspring. Pregnant women should follow the appropriate weight gain program and help their children to prevent from becoming obese.

[Application of spatial statistics in studying the distribution of food contamination]

Objective: Based on data related to arsenic contents in paddy rice, as part of the food safety monitoring programs in 2017, to discuss and explore the application of spatial analysis used for food safety risk assessment. Methods: One province was chosen to study the spatial visualization, spatial point model estimation, and kernel density estimation. Moran's I statistic of spatial autocorrelation methods was used to analyze the spatial distribution at the county level. Results: Data concerning the spatial point model estimation showed that the spatial distribution of pollution appeared relatively dispersive. From the kernel density estimation, we found that the hot spots of pollution were mainly located in the central and eastern regions. The global Moran's I values appeared as 0.11 which presented low spatial aggregation to the rice arsenic contamination and with statistically significant differences. One "high-high" and two typical "low-low" clustering were seen in this study. Conclusion: Results from our study provided good visual demonstration, identification of pollution distribution rules, hot spots and aggregation areas for research on the distribution of food pollutants. Spatial statistics can provide technical support for the implementation of issue-based monitoring programs.

[Clinical characteristics and renal uric acid excretion in early-onset gout patients]

Objective: To investigate clinical characteristics and renal uric acid excretion in early-onset gout patients. Methods: Consecutive inpatients with primary gout were recruited between 2013 and 2017. The patients with gout onset younger than 30 were defined as early-onset group while the others were enrolled as control group. Clinical characteristics and uric acid (UA) indicators were compared between two groups. Results: Among 202 recruited patients, the early-onset group included 36 patients (17.8%). Compared with control group, the early-onset group presented more patients with obesity [13 patients (36.1%) vs. 22 patients (13.3%), P<0.05], significantly higher serum UA level [(634±124)μmol/L vs.(527±169)μmol/L] and glomerular load of UA[(7.2±2.8)mg·min(-1)·1.73m(-2) vs. (4.4±2.2)mg·min(-1)·1.73m(-2)] and estimated glomerular filtration rate (GFR) [(83±21)ml·min(-1)·1.73m(-2) vs. (67±21)ml·min(-1)·1.73m(-2)] (all P<0.05), lower fractional excretion of UA [4.4% (3.4%,6.1%) vs. 7.2% (5.2%,9.6%),P<0.05], whereas 24h urinary UA excretion was comparable [(2 788±882)μmol/1.73m(2) vs. (2 645±1 140)μmol/1.73m(2), P=0.274]. Subgroup analysis of patients without chronic kidney disease showed significantly lower fractional excretion of UA in the early-onset group [4.5%(3.3%,6.1%) vs. 6.7% (5.1%,8.7%),P<0.05]. Logistic regression analysis showed that obesity (OR=3.25) and fractional excretion of UA less than 7% (OR=9.01, all P<0.05) were risk factors of gout early onset. Conclusion: The gout patients with early-onset younger than 30 present high serum and glomerular load of uric acid which might be due to obesity and relative under-excretion of renal uric acid.

[Influence of coke oven emissions on workers' blood pressure and electrocardiographic findings]

Objective: To investigate the influence of coke oven emissions on workers' blood pressure and electrocardiographic findings, and to provide a basis for the prevention and treatment of cardiovascular diseases. Methods: The concentration of coke oven emissions at the bottom, side, and top of coke ovens was determined in a coking plant. A total of 406 coke oven workers were enrolled as exposure group and 201 office staff members were enrolled as control group. Blood pressure and electrocardiographic findings were compared between the two groups, and the multivariate logistic regression analysis was performed to analyze the influencing factors for hypertension and abnormal electrocardiographic findings. Results: The concentration of coke oven emissions was the highest at the top of coke ovens, followed by the side and bottom of coke ovens, and there was a significant difference between the exposure group and the control group (P<0.01). The exposure group had significantly higher detection rates of hypertension, abnormal electrocardiographic findings, and abnormal chest X-ray findings than the control group (P<0.05). The logistic regression analysis showed that high concentration of coke oven emission and age were risk factors for hypertension and abnormal electrocardiographic findings (P<0.05). The workers exposed to high-concentration coke oven emissions were more likely to experience hypertension and abnormal electrocardiographic findings than those exposed to low-concentration coke oven emissions (OR=1.7 and 1.9). Conclusion: Besides lung injury, coke oven emissions also have adverse effects on the cardiovascular system. Therefore, more effective measures are needed to protect the health of coke oven workers.

[Clinical features of mononucleosis because of Epstein-Barr virus and cytomegalovirus co-infection in adult patients]

Objective: To identify the clinical features of mononucleosis caused by co-infection of Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in adult patients. Methods: A total of 103 inpatients with mononucleosis in Peking University Third Hospital from May 2013 to May 2016 were collected as the study subjects.The patients were divided into three groups according to the responsible pathogens: 33 patients infected with EBV and CMV, 53 infected with EBV alone and 17 infected with CMV alone.Furthermore, a case-control study was employed to retrospectively compare the clinical characteristics and prognosis with χ(2,) t or rank tests. Results: The incidences of sore throat, pharynx congestion, tonsil enlargement, tonsil membrane, lymphadenectasis in co-infected patients were statistically lower than those in EBV-infected patients(χ(2)=19.202-25.492, all P<0.05), and were equivalent to those in CMV-infected patients(χ(2)=0.078-4.381, all P>0.05). The levels of alkaline phosphatase, glutamyl transferase, lactic dehydrogenase, white blood cell count and atypical lymphocyte in co-infected patients were statistically lower than those in EBV-infected patients(t/U=3.471-104.629, all P<0.05), and were similar to those in CMV-infected patients(t/U=0.447-24.330, all P>0.05). The levels of alanine aminotransferase and total bilirubin in co-infected patients were equivalent to those in the other two groups(U=1.695, 6.371, both P>0.05). The duration of fever in co-infected patients[(18±9) d] was between EBV alone [(15±7) d] and CMV alone [(21±7) d]infected patients. Conclusions: Co-infection of EBV and CMV is not uncommon.The clinic manifestation of co-infection is more like CMV infection. Liver injury and duration of fever shows no aggravation.

Determination of the Spin and Parity of the Z_{c}(3900)

The spin and parity of the Z_{c}(3900)^{±} state are determined to be J^{P}=1^{+} with a statistical significance larger than 7σ over other quantum numbers in a partial wave analysis of the process e^{+}e^{-}→π^{+}π^{-}J/ψ. We use a data sample of 1.92  fb^{-1} accumulated at sqrt[s]=4.23 and 4.26 GeV with the BESIII experiment. When parametrizing the Z_{c}(3900)^{±} with a Flatté-like formula, we determine its pole mass M_{pole}=(3881.2±4.2_{stat}±52.7_{syst})  MeV/c^{2} and pole width Γ_{pole}=(51.8±4.6_{stat}±36.0_{syst})  MeV. We also measure cross sections for the process e^{+}e^{-}→Z_{c}(3900)^{+}π^{-}+c.c.→J/ψπ^{+}π^{-} and determine an upper limit at the 90% confidence level for the process e^{+}e^{-}→Z_{c}(4020)^{+}π^{-}+c.c.→J/ψπ^{+}π^{-}.

Association of NT-proBNP and interleukin-17 levels with heart failure in elderly patients

Pro-B-type natriuretic peptide (NT-proBNP) and interleukin-17 (IL-17) are involved in the pathophysiological processes of heart failure; however, the exact role of IL-17 is not clear. We explored the relationship between IL-17 and NT-proBNP, as a clinical parameter, in heart failure. The whole blood IL-17 and NT-proBNP levels and the readmission rates in 70 patients with chronic heart failure class III or IV according to the New York Heart Association and 35 patients with normal heart function (control group) were measured and compared. The left ventricle ejection fractions (LVEFs) and NT-proBNP and IL-17 levels in cardiac functional class III (40.38 ± 4.76%, 7780 ± 6393 pg/mL, 8.65 ± 3.05 pg/mL, respectively) and class IV (31.59 ± 4.31%, 13,704 ± 10,945, 21.10 ± 10.60 pg/mL, respectively) were higher than those in the control group (61.27 ± 5.66%, 420 ± 256 pg/mL, 3.53 ± 2.05 pg/mL, respectively). Compared to the cardiac functional class IV, class III showed significantly higher values for LVEF and NT-proBNP and IL-17 levels (P < 0.05). The readmission rates of the patients in cardiac functional class III at 3 and 6 months (15.7 and 34.4%, respectively) and cardiac functional class IV at 3 and 6 months (39.5 and 76.3%, respectively) were significantly higher than those in the control group (0 and 5.7%, respectively) (P < 0.05). The NT-proBNP and IL-17 levels increased as the heart function worsened. NT-proBNP and IL-17 may play essential roles in the process of heart failure.

Observation of the Singly Cabibbo-Suppressed Decay D^{+}→ωπ^{+} and Evidence for D^{0}→ωπ^{0}

Based on 2.93  fb^{-1} e^{+}e^{-} collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report searches for the singly Cabibbo-suppressed decays D^{+}→ωπ^{+} and D^{0}→ωπ^{0}. A double tag technique is used to measure the absolute branching fractions B(D^{+}→ωπ^{+})=(2.79±0.57±0.16)×10^{-4} and B(D^{0}→ωπ^{0})=(1.17±0.34±0.07)×10^{-4}, with statistical significances of 5.5σ and 4.1σ, where the first and second uncertainties are statistical and systematic, respectively.

Observation of a Neutral Structure near the DD[over ¯]^{*} Mass Threshold in e^{+}e^{-}→(DD[over ¯]^{*})^{0}π^{0} at sqrt[s]=4.226 and 4.257 GeV

A neutral structure in the DD[over ¯]^{*} system around the DD[over ¯]^{*} mass threshold is observed with a statistical significance greater than 10σ in the processes e^{+}e^{-}→D^{+}D^{*-}π^{0}+c.c. and e^{+}e^{-}→D^{0}D[over ¯]^{*0}π^{0}+c.c. at sqrt[s]=4.226 and 4.257 GeV in the BESIII experiment. The structure is denoted as Z_{c}(3885)^{0}. Assuming the presence of a resonance, its pole mass and width are determined to be [3885.7_{-5.7}^{+4.3}(stat)±8.4(syst)]  MeV/c^{2} and [35_{-12}^{+11}(stat)±15(syst)]  MeV, respectively. The Born cross sections are measured to be σ[e^{+}e^{-}→Z_{c}(3885)^{0}π^{0},Z_{c}(3885)^{0}→DD[over ¯]^{*}]=[77±13(stat)±17(syst)]  pb at 4.226 GeV and [47±9(stat)±10(syst)]  pb at 4.257 GeV. The ratio of decay rates B[Z_{c}(3885)^{0}→D^{+}D^{*-}+c.c.]/B[Z_{c}(3885)^{0}→D^{0}D[over ¯]^{*0}+c.c.] is determined to be 0.96±0.18(stat)±0.12(syst), consistent with no isospin violation in the process, Z_{c}(3885)^{0}→DD[over ¯]^{*}.

Dynamic left ventricular outflow tract obstruction in apical ballooning syndrome (Takotsubo cardiomyopathy)

Patients with apical ballooning syndrome may develop dynamic left ventricular outflow obstruction due to systolic anterior motion of the mitral valve leaflet and secondary functional mitral regurgitation, causing decreased cardiac output and hypotension. If suspected, bedside echocardiography will quickly confirm this complication. Positive inotropic/chronotropic agents should be avoided as they may exacerbate outflow tract obstruction, resulting in further hemodynamic compromise.

Survival outcomes in patients with early stage, resected pancreatic cancer - a comparison of gemcitabine- and 5-fluorouracil-based chemotherapy and chemoradiation regimens

PURPOSE

We conducted a comparative survival analysis between patients with resected pancreatic cancer who received adjuvant treatment with either gemcitabine- or 5-fluorouracil-based chemotherapy and chemoradiation regimens.

PATIENTS AND METHODS

The Surveillance, Epidemiology and End Results (SEER)-Medicare database was used to identify patients with pancreatic cancer diagnosed from 1998 to 2005 who received curative surgery and adjuvant chemotherapy with either 5-fluorouracil or gemcitabine. These groups were subdivided by treatment with radiotherapy. Patients were followed until death, study end-point or a maximum of 5 years after diagnosis.

RESULTS

Three hundred and fifty-nine patients received 5-fluorouracil and 346 received gemcitabine. Compared with chemoradiation with 5-fluorouracil, outcomes for patients who received chemoradiation with gemcitabine did not differ. Patients who received gemcitabine without radiation had increased hazards (poorly differentiated tumours: HR = 1.50, p = 0.01; moderately differentiated tumours, HR = 1.28, p = 0.11). However, outcomes of patients who received 5-fluorouracil without radiation varied with tumour grade. In moderately differentiated tumours, patients had better outcomes with 5-fluorouracil when compared with chemoradiation with 5-fluorouracil (HR = 0.42, p = 0.02). In poorly differentiated tumours, the opposite was true (HR 2.10, p = 0.09).

CONCLUSION

Patients with low-grade resected pancreatic cancer may have better outcomes with 5-fluorouracil-based chemotherapy without radiation when compared with 5-fluorouracil with radiation.

Genetic relationship between lodging and lodging components in barley (Hordeum vulgare) based on unconditional and conditional quantitative trait locus analyses

Lodging (LD) is a major constraint limiting the yield and forage quality of barley. Detailed analyses of LD component (LDC) traits were conducted using 246 F2 plants generated from a cross between cultivars ZQ320 and 1277. Genetic relationships between LD and LDC were evaluated by unconditional and conditional quantitative trait locus (QTL) mapping with 117 simple sequence repeat markers. Ultimately, 53 unconditional QTL related to LD were identified on seven barley chromosomes. Up to 15 QTL accounted for over 10% of the phenotypic variation, and up to 20 QTL for culm strength were detected. Six QTL with pleiotropic effects showing significant negative correlations with LD were found between markers Bmag353 and GBM1482 on chromosome 4H. These alleles and alleles of QTL for wall thickness, culm strength, plant height, and plant weight originated from ZQ320. Conditional mapping identified 96 additional QTL for LD. Conditional QTL analysis demonstrated that plant height, plant height center of gravity, and length of the sixth internode had the greatest contribution to LD, whereas culm strength and length of the fourth internode, and culm strength of the second internode were the key factors for LD-resistant. Therefore, lodging resistance in barley can be improved based on selection of alleles affecting culm strength, wall thickness, plant height, and plant weight. The conditional QTL mapping method can be used to evaluate possible genetic relationships between LD and LDC while efficiently and precisely determining counteracting QTL, which will help in understanding the genetic basis of LD in barley.

Spontaneous coronary artery dissection: is there a metabolic association?

Spontaneous coronary artery dissection is an uncommon cause of chest pain and acute myocardial infarction, occurring most classically in young women without cardiovascular risk factors. We present a case of a man presenting with chest pain and arrhythmia found to have multivessel spontaneous coronary artery dissection and hyperhomocysteinemia and we raise the possibility of a potential link between the two conditions.

Haemophilus parainfluenzae prosthetic valve endocarditis complicated by septic emboli to brain

A 51-year-old man with a history of injection drug use presented to the emergency roomwith fevers, chills and headaches. Five months earlier, he had undergone bioprosthetic aortic valve replacement for infective endocarditis owing to Corynebacterium auricumosum involving a bicuspid aortic valve. Blood cultures obtained during current hospitalisation grew Haemophilus parainfluenzae and patient underwent a transesophageal echocardiogram that revealed a large mitral valve vegetation. Owing to persistent headache and right lower extremity weakness, MRI of the brain was performed which demonstrated multifocal, acute infarctions secondary to septic embolisation. He was initiated on parenteral antibiotics and experienced no further neurological setbacks. After 2 weeks of antibiotic therapy, he underwent bioprosthetic aortic and mitral valve replacement, aortic root debridement and replacement, and reconstruction of the intravalvular fibrosa without complication. He was discharged to a skilled nursing facility to complete six more weeks of intravenous ceftriaxone.

Conformational study of N(epsilon)-(carboxymethyl)lysine adducts of recombinant gammaC-crystallin

N(epsilon)-(carboxymethyl)lysine, an advanced glycation end product, is present in the human lens. The effects of CML formation on protein conformation and stability were studied using the recombinant gammaC-crystallin as a model. Conformational change was studied by spectroscopic measurements such as fluorescence and circular dichroism. Conformational stability was determined by unfolding with heat. The results indicated that no conformational change was observed due to CML formation, but conformational stability decreased. These observations can be explained in terms of the relatively stable structure of gamma-crystallin, especially when compared with other crystallins. The lens nucleus is rich in gamma-crystallin and its stable conformation can assist gamma-crystallin sustained insults and remain soluble.

Spectroscopic analysis of lens recombinant betaB2- and gammaC-crystallin

PURPOSE

To compare the spectroscopic and unfolding properties of human lens [beta]B2- and [gamma]C-crystallin with those of [alpha]A-crystallin.

METHODS

Human lens [beta]B2- and [gamma]C-crystallin were cloned and measured spectroscopically. The unfolding curves in response to guanidine HCl (GdnHCl) and heat were also obtained by measuring Trp fluorescence emission intensity or emission maximum wavelength with increasing perturbation.

RESULTS

Very similar spectroscopic and unfolding properties were seen with [beta]B2- and [gamma]C-crystallin, but both demonstrated great differences compared with [alpha]A-crystallin. Unlike [alpha]A-crystallin, [beta]B2- and [gamma]C-crystallin showed very little binding to Bis-ANS (4,4'-dianilino-1,1'-binaphthalene-5,5'-disulfonic acid), a hydrophobic fluorescence probe. Both [beta]B2- and [gamma]C-crystallin were more resistant than [alpha]A-crystallin to GdnHCl-induced unfolding, but [alpha]A-crystallin was more resistant than [beta]B2- and [gamma]C-crystallin to heat induced unfolding.

CONCLUSIONS

It was observed that [beta]B2- and [gamma]C-crystallin showed more similar spectroscopic and unfolding properties with each other than each of them showed with [alpha]A-crystallin.

Examining multicultural counseling competence and race-related attitudes among white marital and family therapists

This study investigates the relative contributions of social desirability attitudes, previous number of multicultural counseling courses taken, and racism and White racial identity attitudes together in predicting marital and family therapists' self-reported multicultural counseling competence. Results revealed that, when controlling for social desirability attitudes and the number of multicultural courses taken, racism and White racial identity attitudes in consort accounted for a significant amount of the variance in self-perceived multicultural counseling competence. Implications for marital and family therapy training, practice, and research are discussed.

Oxidation of human lens recombinant alphaA-crystallin and cysteine-deficient mutants

Disulfide cross-linking, one of the results of oxidative stress, has been thought to play an important role in cataractogenesis. High molecular mass (HMM) protein aggregation also contributes to cataract development, and a prevailing speculation is that disulfide cross-linking induces HMM aggregation. However, there is no direct evidence to support this speculation. Dimerization is an effect of disulfide cross-linking but cannot explain the size of HMM aggregates observed in the lens. alphaA-crystallin has two cysteine residues (Cys131 and Cys142) and we have prepared three Cys-deficient mutants, two single mutants (C131I and C142I) and one double mutant (C131I/C142I). They were subjected to H202 oxidation in an ascorbate-FeCl(3)-EDTA-H202 system. The effects of oxidation on the mutants, including changes in aggregate size and conformation, were compared with those of the wild-type alphaA-crystallin by FPLC gel filtration, absorption, fluorescence, and circular dichroism measurements. The results indicated that other amino acid residues besides Cys, such as Trp and Tyr, were also oxidized by H202. Disulfide dimerization alone seems to play a less important role in HMM aggregation than does the secondary conformational change resulting from the combined effect of the oxidation of Trp and Tyr as well as Cys.

Interaction between beta-amyloid and lens alphaB-crystallin

In Alzheimer's disease, beta-amyloid peptides (betaA(1-40) and betaA(1-42)) are deposited on the brain cell surfaces as neurotoxic plaques. Some reports indicate that small heat shock proteins, Hsp27 and alphaB-crystallin, colocalize in the plaques, but their functions are not known. Interaction between betaA and alphaB-crystallin must be determined in order to understand the role of alphaB-crystallin in betaA fibril formation. We used a pyrene (Pyr)-labeled betaA(1-40) in a fluorescence energy transfer experiment. Upon incubation together at 37 degrees C, energy transfer between Trp of alphaB-crystallin and Pyr of Pyr-labeled betaA was observed, indicating that betaA participated in subunit exchange of alphaB-crystallin, which promoted fibril formation.

Human lens high-molecular-weight alpha-crystallin aggregates

Alpha-crystallin high-molecular-weight (HMW) aggregates can be formed in vitro by many mechanisms, but the mechanism of in vivo aggregation has not been clearly established. HMW and LMW (low-molecular-weight) alpha-crystallins were isolated from human lenses 50-60 years of age and some spectroscopic measurements were performed. Conformational differences were suggested based on data of increased bis-ANS (4,4'-dianilino-1,1'-binaphthalene-5, 5'-disulfonic acid) and ThT (thioflavin T) fluorescence as well as increased far-UV and decreased near-UV circular dichroism (CD). These results indicated that HMW alpha-crystallin was more hydrophobic than LMW alpha-crystallin, possibly resulting from partial unfolding of alpha-crystallin. On the other hand, the increased ThT fluorescence and far-UV CD intensities indicate that an increased amount of beta-sheet conformation was involved in aggregation. These data, along with little difference in chaperone-like activity between the LMW and HMW alpha-crystallins, strongly suggest that HMW alpha-crystallin aggregates resulted from partial unfolding and disassembling-reassembling of LMW alpha-crystallin caused by posttranslational modification rather than chaperone complex formation.

RGS7 complex formation and colocalization with the Gbeta5 subunit in the adult rat brain and influence on Gbeta5gamma2-mediated PLCbeta signaling

This study describes the colocalized distribution and dimeric complex formation between RGS7, a GTPase-activating protein for several heterotrimeric Galpha protein families, and the Gbeta5 subunit in the adult rat brain. Confocal dual immunofluorescence labeling studies indicated a broad regional specificity in the cellular coexpression between RGS7 and Gbeta5 within the cerebral cortical layers I and V-VI, hippocampal formation, caudate-putamen, medial habenula, most thalamic nuclei, and cerebellar molecular and granular layers. In all instances, Gbeta1-beta4 immunoreactivities exhibited no observable colocalization with RGS7, despite their widespread codistribution throughout similar neuronal networks. Coimmunoprecipitation studies confirmed the selective protein-protein interaction between RGS7 and Gbeta5 within brain regions that displayed immunohistochemical colocalization. The influence of RGS7 to modulate Gbeta5gamma2-mediated phosphatidyl inositol (PI) production was examined in COS-7-cotransfected cells. In the presence of Gbeta5gamma2 only, intracellular PI accumulation was increased by 25% above basal levels; addition of RGS7 produced no significant alteration in Gbeta5gamma2-mediated PI accumulation. A similar trend was exhibited when full-length RGS7 was substituted with an RGS7 construct lacking the Gbeta5-interacting region (G protein gamma-like domain; GGL domain) or with RGS4. In conclusion, RGS7/Gbeta5 dimers occurred within most brain regions in which both proteins were cellularly coexpressed. However, an influence of RGS7 on Gbeta5gamma2-mediated PLCbeta signaling activity was not apparent, athough this was in COS-7 cell transfection studies.

Heat-induced conformational change of human lens recombinant alphaA- and alphaB-crystallins

PURPOSE

To determine which component of lens alpha-crystallin is responsible for heat-induced transition, conformational change and high molecular weight (HMW) aggregation.

METHODS

Recombinant alphaA- and alphaB-crystallins were used. Temperature dependent changes were probed by Trp fluorescence and circular dichroism (CD) measurements. HMW aggregates were induced by heating at 62 degrees C for 1-2 h and then cooling to room temperature. The nature of HMW aggregation was studied with fluorescent probes, 4,4'-dianilino-1, 1'-binaphthalene-5,5'-disulfonic acid (bis-ANS) and thioflavin T (ThT).

RESULTS

CD and Trp fluorescence revealed that alphaB-crystallin was more susceptible than alphaA-crystallin to heat-induced conformational change and aggregation. At temperatures greater than 70 degrees C, alphaB-crystallin precipitated but alphaA-crystallin remained soluble. Both bis-ANS and ThT probes displayed increased fluorescence intensity with HMW aggregation, but the increase for bis-ANS was greater with alphaB-crystallin than with alphaA-crystallin, while the reverse was true for ThT.

CONCLUSIONS

These results indicate that alphaB-crystallin is more susceptible than alphaA-crystallin to heat-induced conformational change and aggregation and are consistent with the notion that alphaA- and alphaB-crystallins have different biochemical and biophysical properties in spite of their high degree of homology.

Spectral contribution of the individual tryptophan of alphaB-crystallin: a study by site-directed mutagenesis

There are two tryptophan residues in the lens alphaB-crystallin, Trp9 and Trp60. We prepared two Trp --> Phe substituted mutants, W9F and W60F, for use in a spectroscopic study. The two tryptophan residues contribute to Trp fluorescence and near-ultraviolet circular dichroism (UV CD) differently. The major difference in the near-UV CD is the contribution of 1La of Trp: it is positive in W60F but becomes negative in W9F. Further analysis of the near-UV CD shows an increased intensity in the region of 270-280 nm for W60F, suggesting that the Tyr48 is affected by the W60F mutation. It appears that Trp60 is located in a more rigid environment than Trp9, which agrees with a recent structural model in which Trp60 is in a beta-strand.

Thermodynamic stability of human lens recombinant alphaA- and alphaB-crystallins

Lens alpha-crystallin is a 600-800-kDa heterogeneous oligomer protein consisting of two subunits, alphaA and alphaB. The homogeneous oligomers (alphaA- and alphaB-crystallins) have been prepared by recombinant DNA technology and shown to differ in the following biophysical/biochemical properties: hydrophobicity, chaperone-like activity, subunit exchange rate, and thermal stability. In this study, we studied their thermodynamic stability by unfolding in guanidine hydrochloride. The unfolding was probed by three spectroscopic parameters: absorbance at 235 nm, Trp fluorescence intensity at 320 nm, and far-UV circular dichroism at 223 nm. Global analysis indicated that a three-state model better describes the unfolding behavior than a two-state model, an indication that there are stable intermediates for both alphaA- and alphaB-crystallins. In terms of standard free energy (DeltaG(NU)(H(2)(O))), alphaA-crystallin is slightly more stable than alphaB-crystallin. The significance of the intermediates may be related to the functioning of alpha-crystallins as chaperone-like molecules.

Expression of dopamine receptors in the subthalamic nucleus of the rat: characterization using reverse transcriptase-polymerase chain reaction and autoradiography

We analysed the expression of dopamine receptor subtypes in the subthalamic nucleus by means of reverse transcriptase-polymerase chain reaction. We also studied, using autoradiography, all pharmacologically characterized dopamine receptors in four subregions of the subthalamic nucleus. For comparison, dopamine receptor subtypes were also evaluated in brain regions where they are more abundant and well characterized. The radioligands used were: [3H]SCH-23390, [3H]emonapride and [3H]2-dipropylamino-7-hydroxy-1,2,3,4-tetrahydronaphthalene for dopamine D1, D2 and D3 receptors, respectively; and [3H]YM-09151-2 in the presence of raclopride for dopamine D4 receptors. Finally, we also evaluated the effect of unilateral 6-hydroxydopamine injection into the medial forebrain bundle on dopamine receptor levels expressed in the ipsilateral subthalamic nucleus. The lesion was estimated by decrease in the binding of [3H]WIN-35428, a specific dopamine transporter label. D1, D2 and D3 receptor messenger RNAs and binding sites were present in the subthalamic nucleus, but no messenger RNA for D4 receptors was found, although specific binding sites for these receptors were observed. As compared to the intact side, the 6-hydroxydopamine lesion did not change D1 receptors, increased D2 receptors, and decreased D3 receptors and the dopamine transporter. The results suggest that postsynaptic D1, D2 or D3 receptors can mediate the effect of dopamine on subthalamic nucleus neuronal activity. D4 receptors would mediate exclusively presynaptic effects. These results reinforce the idea that dopamine receptors in the subthalamic nucleus may play an important role in the physiology of the basal ganglia and in the pathophysiology of Parkinson's disease.

Site-directed mutations within the core "alpha-crystallin" domain of the small heat-shock protein, human alphaB-crystallin, decrease molecular chaperone functions

Site-directed mutagenesis was used to evaluate the effects on structure and function of selected substitutions within and N-terminal to the core "alpha-crystallin" domain of the small heat-shock protein (sHsp) and molecular chaperone, human alphaB-crystallin. Five alphaB-crystallin mutants containing single amino acid substitutions within the core alpha-crystallin domain displayed a modest decrease in chaperone activity in aggregation assays in vitro and in protecting cell viability of E. coli at 50 degrees C in vivo. In contrast, seven alphaB-crystallin mutants containing substitutions N-terminal to the core alpha-crystallin domain generally resembled wild-type alphaB-crystallin in chaperone activity in vitro and in vivo. Size-exclusion chromatography, ultraviolet circular dichroism spectroscopy and limited proteolysis were used to evaluate potential structural changes in the 12 alphaB-crystallin mutants. The secondary, tertiary and quaternary structures of mutants within and N-terminal to the core alpha-crystallin domain were similar to wild-type alphaB-crystallin. SDS-PAGE patterns of chymotryptic digestion were also similar in the mutant and wild-type proteins, indicating that the mutations did not introduce structural modifications that altered the exposure of proteolytic cleavage sites in alphaB-crystallin. On the basis of the similarities between the sequences of human alphaB-crystallin and the sHsp Mj HSP16.5, the only sHsp for which there exists high resolution structural information, a three-dimensional model for alphaB-crystallin was constructed. The mutations at sites within the core alpha-crystallin domain of alphaB-crystallin identify regions that may be important for the molecular chaperone functions of sHsps.

Conformational study of N(epsilon)-(carboxymethyl)lysine adducts of recombinant alpha-crystallins

PURPOSE

Lens proteins underwent nonenzymatic glycation, and the advanced glycation end products (AGEs) were detected by immunological assays. One of the major AGE structures is N(epsilon)-(carboxymethyl)lysine (CML). Since the involvement of AGEs in the pathogenesis of diabetic complications is speculated, the effects of CML formation on proteins were studied.

METHODS

CML adducts were generated in recombinant alphaA- and alphaB-crystallins by incubation with glyoxylic acid and NaBH3CN. SDS-PAGE and size exclusion chromatography were used to detect subunit degradation and high-molecular-weight (HMW) aggregation. Conformational change was determined by fluorescence and circular dichroism (CD) measurements. The chaperone function was studied by DTT-induced aggregation of insulin.

RESULTS

Lysine modification was estimated to be 60-90% depending on the conditions of incubation. No subunit degradation or HMW aggregation was observed. Fluorescence and CD measurements detected a conformational change in CML adducts. Measurements of chaperone-like activity, however, indicated that the formation of CML increased the protein's ability to protect insulin against DTT-induced aggregation.

CONCLUSIONS

Although CML adducts of alphaA- and alphaB-crystallins, the major AGE structures formed in vitro, changed protein conformation, no subunit degradation and HMW aggregation were observed. Moreover, the CML adducts increased chaperone-like activity of both alphaA- and alphaB-crystallins. The results suggest that CML formation alone may not play a major role in protein aggregation and lens opacity.

Photooxidized products of recombinant alpha A-crystallin and W9F mutant

Human lenses contain many photosensitizers that absorb light at wavelengths above 300 nm, most notably UVA light (320-400 nm). Kynurenine (Kyn) and 3-hydroxykynurenine (HK), two of the best-known photosensitizers in the human lens, may play a significant role in photooxidation-related changes in lens proteins, such as conformational change and aggregation. In vitro irradiation experiments with proteins indicate that the Trp residue (with maximal absorption at 295 nm) is more susceptible to photooxidation by UVB light (280-320 nm) than by UVA light, but most UVB light below 300 nm is screened by the cornea and little reaches the lens, especially the nuclear region where nuclear color develops. Therefore, if photooxidation is an important contributor to nuclear color or nuclear cataract, it must arise from a photosensitized reaction. In the present study, we use recombinant alpha A- and its Trp-deficient mutant W9F as models to study the effects of UVA irradiation in the presence of HK or Kyn and of UVB (300 nm) irradiation on alpha-crystallins. alpha A-crystallin showed a large decrease in Trp fluorescence and a large increase in non-Trp (blue) fluorescence after the HK-sensitized or 300 nm photooxidation. For the W9F mutant, a smaller decrease in protein fluorescence (lambda ex at 280 nm) and a smaller increase in blue fluorescence than for the wild-type alpha A-crystallin were observed. A decrease in the near-UV CD was also observed for both photooxidized alpha A and the W9F mutant. The effect of Kyn sensitization is smaller than that of HK sensitization. A study of chaperone-like activity indicated that only 300 nm photooxidized alpha A and the W9F mutant increased the ability to protect insulin from dithiothreitol-induced aggregation. Thus, sensitized photooxidation can occur in amino acids other than Trp by UVA in the presence of HK or Kyn with effects similar to, albeit smaller than, those of direct UVB (300 nm) photooxidation.

Immunohistochemical distribution of RGS7 protein and cellular selectivity in colocalizing with Galphaq proteins in the adult rat brain

Regulators of G protein signaling (RGS) proteins serve as potent GTPase-activating proteins for the heterotrimeric G proteins alphai/o and aq/11. This study describes the immunohistochemical distribution of RGS7 throughout the adult rat brain and its cellular colocalization with Galphaq/11, an important G protein-coupled receptor signal transducer for phospholipase Cbeta-mediated activity. In general, both RGS7 and Galphaq/11 displayed a heterogeneous and overlapping regional distribution. RGS7 immunoreactivity was observed in cortical layers I-VI, being most intense in the neuropil of layer I. In the hippocampal formation, RGS7 immunoreactivity was concentrated in the strata oriens, strata radiatum, mossy fibers, and polymorphic cells, with faint to nondetectable immunolabeling within the dentate gyrus granule cells and CA1-CA3 subfield pyramidal cells. Numerous diencephalic and brainstem nuclei also displayed dense RGS7 immunostaining. Dual immunofluorescence labeling studies with the two protein-specific antibodies indicated a cellular selectivity in the colocalization between RGS7 and Galphaq/11 within many discrete brain regions, such as the superficial cortical layer I, hilus area of the hippocampal formation, and cerebellar Golgi cells. To assess the ability of Galphaq/11-mediated signaling pathways to modulate dynamically RGS expression, primary cortical neuronal cultures were incubated with phorbol 12,13-dibutyrate, a selective protein kinase C activator. A time-dependent increase in levels of mRNA for RGS7, but not RGS4, was observed. Our results provide novel information on the region- and cell-specific pattern of distribution of RGS7 with the transmembrane signal transducer, Galphaq/11. We also describe a possible RGS7-selective neuronal feedback adaptation on Galphaq/11-mediated pathway function, which may play an important role in signaling specificity in the brain.

Conformational change of human lens insoluble alpha-crystallin

Human lens alpha-crystallin becomes progressively insoluble with age and is the major crystallin component in the water-insoluble (WI) fraction. The mechanism that causes the originally water-soluble (WS) alpha-crystallin to become insoluble is unknown. A conformational change by chemical modification may be the cause, but the nature of insolubility renders it impossible to study protein conformation in the WI fraction by most spectroscopic measurements. In the present study, alpha-crystallin in the WI fraction was extracted by urea and reconstituted to a folded protein by dialysis. The refolded urea-soluble (US) alpha-crystallin was compared with WS alpha-crystallin. The US alpha-crystallin has a greater amount of polymeric species, but fewer degraded subunits than the WS alpha-crystallin as shown by SDS-PAGE and Western blot. Circular dichroism (CD) measurements indicate that they have the same secondary structure but a different tertiary structure, possibly a partial unfolding in the US alpha-crystallin. This is supported by fluorescence measurements: Trp residues are more exposed and protein has a more-hydrophobic surface in the US than in the WS alpha-crystallin. Blue fluorescence further indicates that the US alpha-crystallin has a greater amount of pigment than the WS alpha-crystallin. Together, these results indicate that the US alpha-crystallin is a chemically and conformationally modified protein.

Fluorescence and immunochemical studies of advanced glycation-related lens pigments

PURPOSE

To establish whether advanced glycation is the major mechanism for yellowing of lens proteins.

METHODS

Synchronous fluorescence (SF) and immunochemical assays were used to study glycation in vitro and in vivo. In the in vitro study, advanced glycation end products (AGEs) were prepared and used as antigens to induce antibodies to AGEs. The in vitro AGEs and classified nuclear cataracts were analyzed by SF and immunochemical assays.

RESULTS

In vitro AGEs generated from various glycating agents and carrier proteins displayed strong SF above 350 nm; the spectra were well resolved with major bands at 380 nm and 420 nm. Samples from human lenses manifested a band at 395 nm in addition to the two bands shown by in vitro AGEs. SF intensity is greater for the water-insoluble (WI) than water-soluble (WS) fraction, but both increased with increasing nuclear color. The immunoreactivity data also showed that the WI fraction contained more AGEs than the WS fraction and that the amount of AGEs increased with increasing nuclear color.

CONCLUSIONS

Fluorescence and immunoassays indicated that pigmented AGEs contributed to yellowing of the crystalline lens nucleus.

Thermodynamic and kinetic characterization of calf lens gammaF-crystallin

Gamma-crystallin is reported to be conformationally stable because of its internal structural symmetry, and gammaF (gammaIVa) is the most stable among the various gamma-crystallin gene products. However, there is no detailed report on its thermodynamic and kinetic stability. In the present study, detailed unfolding of gammaF-crystallin was investigated by equilibrium and kinetics methods with fluorescence and far-UV CD spectroscopic measurements. The GdnHCl-induced unfolding curves probed by Trp emission maximum and intensity showed a sharp single-step transition. Upon widening the unfolding transition with the use of urea in 1.5 M GdnHCl, a more proper fit for thermodynamic analysis was obtained. GammaF-Crystallin underwent a straightforward two-state process (N <==> U) without showing any measurable amount of intermediate. The conformational stability, as measured by deltaG(D)H2O (approximately 9 kcal/mol), indicates that gammaF-crystallin is a very stable protein. The high activation energy deltaG++H2O (approximately 24 kcal/mol), calculated from unfolding kinetics monitored by far-UV CD at 218 nm, also indicates that the native and unfolded states are separated by a high activation energy barrier.

Subunit exchange of lens alpha-crystallin: a fluorescence energy transfer study with the fluorescent labeled alphaA-crystallin mutant W9F as a probe

A Trp-free alphaA-crystallin mutant (W9F) was prepared by site-directed mutation. This mutant appears to be identical to the wild-type in terms of conformation (secondary and tertiary structures). W9F was labeled with a sulfhydryl-specific fluorescent probe, 2-(4'-maleimidylanilino) naphthalene-6-sulfonate (MIANS), and used in a subunit exchange between alphaA- and alphaA-crystallins as well as between alphaA- and alphaB-crystallins, studied by measurement of fluorescence resonance energy transfer. Energy transfer was observed between Trp (donor, with emission maximum at 336 nm) of wild-type alphaA- or alphaB-crystallin and MIANS (acceptor, with absorption maximum at 313 nm) of labeled W9F when subunit exchange occurred. Time-dependent decrease of Trp and increase of MIANS fluorescence were recorded. The exchange was faster at 37 degrees C than at 25 degrees C. The energy transfer efficiency was greater between homogeneous subunits (alphaA-alphaA) than between heterogeneous subunits (alphaA-alphaB). A previous exchange study with isoelectric focusing indicated a complete but slow exchange between alphaA and alphaB subunits. The present study showed that the exchange was a fast process, and the different energy transfer efficiencies between alphaA-alphaA and alphaA-alphaB indicated that alphaA- and alphaB-crystallins were not necessarily structurally equivalent.

Immunohistochemical localization of G protein beta1, beta2, beta3, beta4, beta5, and gamma3 subunits in the adult rat brain

The regional distributions of the G protein beta subunits (Gbeta1-beta5) and of the Ggamma3 subunit were examined by immunohistochemical methods in the adult rat brain. In general, the Gbeta and Ggamma3 subunits were widely distributed throughout the brain, with most regions containing several Gbeta subunits within their neuronal networks. The olfactory bulb, neocortex, hippocampus, striatum, thalamus, cerebellum, and brainstem exhibited light to intense Gbeta immunostaining. Negative immunostaining was observed in cortical layer I for Gbeta1 and layer IV for Gbeta4. The hippocampal dentate granular and CA1-CA3 pyramidal cells displayed little or no positive immunostaining for Gbeta2 or Gbeta4. No anti-Gbeta4 immunostaining was observed in the pars compacta of the substantia nigra or in the cerebellar granule cell layer and Purkinje cells. Immunoreactivity for Gbeta1 was absent from the cerebellar molecular layer, and Gbeta2 was not detected in the Purkinje cells. No positive Ggama3 immunoreactivity was observed in the lateral habenula, lateral septal nucleus, or Purkinje cells. Double-fluorescence immunostaining with anti-Ggamma3 antibody and individual anti-Gbeta1-beta5 antibodies displayed regional selectivity with Gbeta1 (cortical layers V-VI) and Gbeta2 (cortical layer I). In conclusion, despite the widespread overlapping distributions of Gbeta1-beta5 with Ggamma3, specific dimeric associations in situ were observed within discrete brain regions.

Intermolecular interaction of lens crystallins: from rotationally mobile to immobile states at high protein concentrations

The conformation of lens crystallins in vivo or in a highly concentrated solution is not well established. Most studies were carried out in dilute solutions in which protein-protein interaction is minimal. In order to see whether there is conformational change (tertiary and secondary structures) when crystallin solutions are brought to high concentrations, we have performed the following molecular spectroscopic measurements: circular dichroism (CD) and Fourier transform infrared (FTIR). Near-UV CD measurements showed a more than two-fold increase in CD intensity (molar ellipticity) for the total water-soluble (WS) protein from young calf lens nucleus in a highly concentrated solution (> 300 mg/ml in a 0.01-mm cell), when compared with a dilute solution (1000-fold dilution in a 10-mm cell). The individual crystallins in concentrated solutions also showed an increase in CD intensity, but of different magnitude: alpha-crystallin > beta-crystallin > gamma-crystallin. The increased CD indicates that lens crystallins are in a more compact structure in highly concentrated solutions; they likely undergo a transition from a mobile to an immobile state. Change in near-UV CD usually is caused by restricted mobility of aromatic side groups, particularly Trp. The transition involves not only a change in protein tertiary and/or quaternary structure, but also in protein backbone structure. The change of protein backbone structure was drawn from FTIR measurements. FTIR spectra, sensitive to the secondary structure in the amide I region, could be measured for a highly concentrated solution for which far-UV CD measurement is not feasible. The secondary structure that showed prominent change for alpha-crystallin in a highly concentrated solution was beta-conformation: increase in beta-turn with a concomitant decrease of alpha-helix structure.

Intermolecular exchange and stabilization of recombinant human alphaA- and alphaB-crystallin

Lens alpha-crystallin subunits alphaA and alphaB are differentially expressed and have a 3-to-1 ratio in most mammalian lenses by intermolecular exchange. The biological significance of this composition and the mechanism of exchange are not clear. Preparations of human recombinant alphaA- and alphaB-crystallins provide a good system in which to study this phenomenon. Both recombinant alphaA- and alphaB-crystallins are folded and aggregated to the size of the native alpha-crystallin. During incubation together, they undergo an intermolecular exchange as shown by native isoelectric focusing. Circular dichroism measurements indicate that the protein with a 3-to-1 ratio of alphaA- and alphaB-crystallins has the same secondary structure but somewhat different tertiary structures after exchange: the near-UV CD increases after exchange. The resulting hybrid aggregate is more stable than the individual homogeneous aggregates: at 62 degrees C, alphaB-crystallin is more susceptible to aggregation and displays a greater light scattering than alphaA-crystallin. This heat-induced aggregation of alphaB-crystallin, however, was suppressed by intermolecular exchange with alphaA-crystallin. These phenomena are also observed by fast performance liquid chromatography gel filtration patterns. The protein structure of alphaB-crystallin is stabilized by intermolecular exchange with alphaA-crystallin.

Cloning and in situ hybridization analysis of the expression of polysialyltransferase mRNA in the developing and adult rat brain

Polysialyltransferase (PST) is an enzyme that catalyzes the addition of polysialic acid (PSA), a homopolymer of alpha-2,8-linked sialic acid residues, onto neural cell adhesion molecule (NCAM). The expression of PSA-NCAM in the brain is developmentally regulated and is of critical importance; however, the temporal and spatial developmental expression of brain PST, a potential key player in the control of PSA-NCAM levels, remains unclear. In the present study, we have cloned the coding region of rat PST cDNA by reverse transcription-polymerase chain reaction, using primers based on the hamster PST-1 cDNA sequence. A 39-mer oligonucleotide complementary to rat PST cDNA was synthesized to investigate the distribution of its mRNA in the developing and adult rat brain by Northern blot and in situ hybridization. In the embryonic rat brain, PST mRNA was detected abundantly throughout the neuroepithelia of most brain regions. At post-natal days 1 and 14, PST was detected throughout the neocortex, in the pyramidal cells (PC) of the hippocampus proper, the granule cell layer (GCL) of the dentate gyrus, the anterior ventral nucleus of the thalamus (AVNT) and the GCL and external germinal layer of the cerebellum. Finally, from PD21 until adulthood, expression of PST mRNA was restricted to the PC layer of the hippocampus proper, the GCL of the dentate gyrus, the AVNT, the GCL of the cerebellum and the dorsal and lateral nucleus of the anterior olfactory bulb. The developmental profile of PST mRNA is paralleled in some structures by that of the PSA-NCAM, there are, however, notable exceptions. Therefore, our results demonstrate that expression of rat PST mRNA is developmentally regulated, is present in the adult rat brain in restricted areas and may be involved in regulating temporal and spatial expression of PSA-NCAM.