Effects of Salt Stress on Physiological and Agronomic Traits of Rice Genotypes with Contrasting Salt Tolerance

Salinity is one of the major constraints to crop production. Rice is a main staple food and is highly sensitive to salinity. This study aimed to elucidate the effects of salt stress on physiological and agronomic traits of rice genotypes with contrasting salt tolerance. Six contrasting rice genotypes (DJWJ, JFX, NSIC, HKN, XD2H and HHZ), including three salt-tolerant and three salt-sensitive rice genotypes, were grown under two different salt concentrations (0 and 100 mmol L-1 NaCl solution). The results showed that growth, physiological and yield-related traits of both salt-sensitive and salt-tolerant rice were significantly affected by salt stress. In general, plant height, tiller number, dry weight and relative growth rate showed 15.7%, 11.2%, 25.2% and 24.6% more reduction in salt-sensitive rice than in salt-tolerant rice, respectively. On the contrary, antioxidant enzyme activity (superoxide dismutase, peroxidase, catalase), osmotic adjustment substances (proline, soluble protein, malondialdehyde (MDA)) and Na+ content were significantly increased under salt stress, and the increase was far higher in salt-tolerant rice except for MDA. Furthermore, grain yield and yield components significantly decreased under salt stress. Overall, the salt-sensitive rice genotypes showed a 15.3% greater reduction in grain yield, 5.1% reduction in spikelets per panicle, 7.4% reduction in grain-filling percentage and 6.1% reduction in grain weight compared to salt-tolerant genotypes under salt stress. However, a modest gap showed a decline in panicles (22.2% vs. 22.8%) and total spikelets (45.4% vs. 42.1%) between salt-sensitive and salt-tolerant rice under salinity conditions. This study revealed that the yield advantage of salt-tolerant rice was partially caused by more biomass accumulation, growth rate, strong antioxidant capacity and osmotic adjustment ability under salt stress, which contributed to more spikelets per panicle, high grain-filling percentage and grain weight. The results of this study could be helpful in understanding the physiological mechanism of contrasting rice genotypes' responses to salt stress and to the breeding of salt-tolerant rice.

[Orthopaedic robot assisted femoral neck dynamic cross fixation system for the treatment of femoral neck fractures]

OBJECTIVE

To explore and compare the clinical efficacy of orthopedic robot assisted femoral neck system （FNS） and traditional manual FNS in the treatment of femoral neck fractures in middle-aged and young people.

METHODS

The clinical data of 62 consecutive patients with femoral neck fracture and age less than 65 years old admitted to the Intelligent Orthopaedic Department of Beijing Jishuitan Hospital from June 2021 to June 2022 were retrospectively analyzed. According to whether orthopedic robot-assisted surgery the patients were divided into two groups：30 patients aged 34 to 56 years old were treated with orthopedic robot assisted FNS internal fixation after closed or limited open reduction（experimental group）； 32 patients aged 33 to 54 years old underwent FNS internal fixation after closed or limited open reduction（control group）. The age, gender, time from injury to admission, average hospital stay, surgical duration, intraoperative bleeding volume, and intraoperative fluoroscopy frequency of two groups of patients were analyzed and compared. The hip joint function in both groups of patients was evaluated using the Harris hip joint scoring standard at 6 months after surgery.

RESULTS

All 62 patients with femoral neck fractures successfully completed the surgery. There was no significant difference（P>0.05） between the experimental group and the control group in terms of baseline data such as age, gender, time from injury to admission, time from admission to surgery and the intraoperative bleeding. The surgical duration of the experimental group was significantly shorter than that of the control group [42.1（28.5, 50.7）min vs. 53.4（36.9, 62.5） min, Z=-2.338, P=0.019]. The intraoperative X-ray fluoroscopy frequency of the experimental group was significantly lower than that of the control group[8.0 （6.0, 11.0） times vs. 15.0（13.0, 17.0） times, Z=-5.960, P<0.001]. In terms of postoperative hip joint function, there was no significant difference in Harris score between the two groups of patients at 6-month follow-up（P>0.05）.

CONCLUSION

Compared with manual operation of FNS, orthopedic robot assisted FNS in the treatment of femoral neck fractures can help shorten surgical time, reduce intraoperative fluoroscopy frequency, and have similar therapeutic effects on long-term hip joint function recovery.

[A multiscale carotid plaque detection method based on two-stage analysis]

OBJECTIVE

To develop a method for accurate identification of multiscale carotid plaques in ultrasound images.

METHODS

We proposed a two-stage carotid plaque detection method based on deep convolutional neural network (SM-YOLO).A series of algorithms such as median filtering, histogram equalization, and Gamma transformation were used to preprocess the dataset to improve image quality. In the first stage of the model construction, a candidate plaque set was built based on the YOLOX_l target detection network, using multiscale image training and multiscale image prediction strategies to accommodate carotid artery plaques of different shapes and sizes. In the second stage, the Histogram of Oriented Gradient (HOG) features and Local Binary Pattern (LBP) features were extracted and fused, and a Support Vector Machine (SVM) classifier was used to screen the candidate plaque set to obtain the final detection results. This model was compared quantitatively and visually with several target detection models (YOLOX_l, SSD, EfficientDet, YOLOV5_l, Faster R-CNN).

RESULTS

SM-YOLO achieved a recall of 89.44%, an accuracy of 90.96%, a F1-Score of 90.19%, and an AP of 92.70% on the test set, outperforming other models in all performance indicators and visual effects. The constructed model had a much shorter detection time than the Faster R-CNN model (only one third of that of the latter), thus meeting the requirements of real-time detection.

CONCLUSION

The proposed carotid artery plaque detection method has good performance for accurate identification of carotid plaques in ultrasound images.

How flare-up of small and medium enterprises intensifies carbon emissions in Asian and European regions: a panel analysis

SMEs (small and medium enterprises) contribute substantially to the global and national economies. So, their activities can significantly affect the ecosystem; however, environmental performance is primarily targeted at larger corporations. Therefore, this study measures the SMEs' impact on environmental quality through CO2 emissions. For this purpose, data on twenty-five Asian and European economies from 2005 to 2020 is utilized, and the effect of SMEs on the environment is measured in the light of the EKC hypothesis. In order to validate and test the influence of SMEs on the environment, the pooled mean group (PMG) model with cointegration approaches is utilized. The results show that the flare-up of small and medium enterprises increases environmental pollution through high carbon emissions at micro levels. Thus, the study suggests that governments, SMEs, and other stakeholders have to create strategies and regulations targeted at SMEs to minimize their negative environmental impact.

The Regularity of Stress Shielding in Internal Fixation Characterized by Hydromechanics

Stress shielding is an important factor in the internal fixation of a fracture. To explore the regularity of stress shielding in internal fixation, a simplified model of a comminuted femoral shaft fracture bridged by a locking plate was established and finite element analysis was performed to analyze the load distribution between the plate and femur from the proximal end of the femur to the fracture line and investigate the stress shielding degree of the plate on the bone. The stress, deformation, and axial compressive force distribution of four internal fixation schemes under compression were obtained, and the stress shielding degrees on each section was calculated. To compare the regularity of stress shielding and flow distribution, the relationship between the compressive force increment and stress shielding degree was established. The normalized curves of compressive force increment with the plate section position were compared with the flow distribution in a Z-type manifold, a parallel pipe system similar to an internal fixation system in structure and working characteristics. For quantitative comparison, the similarity between normalized curves of the compressive force increment and simulated flow distribution was calculated. The regularity of load distribution along the section position of the plate was similar to the flow distribution in the Z-type manifold. Therefore, the flow distribution pattern of the Z-type manifold can be used to characterize the regularity of load distribution in internal fixation. This study provided a new method to characterize the stress shielding degree of a locking plate on bone.

Osteoblasts Regulate the Expression of ADAMTS and MMPs in Chondrocytes through ERK Signaling Pathway

OBJECTIVE

Degradative enzymes such as matrix metalloproteinase (MMP) and disintegrin metalloproteinase with platelet thrombin-sensitive protein-like motifs (ADAMTS) play a key role in the development of osteoarthritis (OA). We aimed to investigate the effects of OA subchondral osteoblasts on the expression of ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 in chondrocytes and the regulation of mitogen-activated protein kinase (MAPK) signaling pathway.

METHODS

A rat knee OA model was constructed by cutting the anterior cruciate ligament of the knee joints, and normal rat articular cartilage chondrocytes (N-ACC), OA rat articular cartilage chondrocytes (O-ACC), normal subchondral bone osteoblasts (N-SBO), and OA subchondral bone osteoblasts (O-SBO) were isolated and extracted. The expressions of O-ACC and O-SBO COL1 and COL2 were detected respectively. Chondrocytes were identified by immunofluorescence of COL2 and toluidine blue staining, and osteoblasts were identified by COL1 immunofluorescence, alkaline phosphatase (ALP), and Alizarin Red staining. Gene expression of COL1, COL2, and aggrecan in normal chondrocytes and OA chondrocytes, and gene expression of osteoblast ALP and osteocalcin (OCN) were detected by RT-PCR to identify the two chondrocytes and the two osteoblast phenotypes. The constructing N-ACC group, O-ACC group, N-ACC + N-SBO group, N-ACC + O-SBO group, O-ACC + N-SBO group, O-ACC + O-SBO group, I + N-ACC + O-SBO group, and I + O-ACC + O-SBO group cell cultures, and the expression of ERK, ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 genes in chondrocytes cultured for 0, 24, 48, and 72 h were detected by RT-PCR. The protein expressions of pERK, ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 were detected by Western blot.

RESULTS

· The X-ray showed that the knee joint space of the affected limb became narrow.. · The results of RT-PCR of COL2 and aggrecan gene in OA and normal chondrocytes suggest that the relative expression of COL2 in OA articular chondrocytes (0.24 ± 0.07) is significantly lower than that in normal cartilage (0.61 ± 0.07) (p < 0.05). The relative expression of AGG (0.37 ± 0.16) in OA chondrocytes was significantly lower than that of normal chondrocytes AGG (1.30 ± 0.25) (p < 0.05). The expression of COL1 was very low, and was not statistically significant.. · The results of RT-PCR of the osteoblast ALP and OCN gene indicated that gene expression of ALP (12.30 ± 1.17) and OCN (20.47 ± 4.19)was upregulated when compared with the relative expression of ALP (4.66 ± 0.71) (p < 0.05) and OCN (12.17 ± 2.76) (p < 0.05) in normal osteoblasts, indicating that osteoblasts of OA have greater osteogenic potential than normal osteoblasts.. · The expressions of ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 genes and proteins in OA chondrocytes or normal chondrocytes were basically unchanged when they were cocultured with normal osteoblasts. Indirect coculture of OA osteoblasts and chondrocytes could promote the expression of ADAMTS4, ADAMTS5, MMP-3, MMP-9, and MMP-13 genes and proteins in chondrocytes. Overexpression of ADAMTS and MMP in coculture systems can be reversed by MAPK-ERK inhibitors..

CONCLUSIONS

· OA subchondral bone osteoblasts can promote the overexpression of ADAMTS and MMPs in chondrocytes.. · The ERK signaling pathway may be involved in the regulation of the effect of subchondral bone osteoblasts on chondrocytes..

Effect and Mechanism of TL1A Expression on Epithelial-Mesenchymal Transition during Chronic Colitis-Related Intestinal Fibrosis

BACKGROUND AND AIMS

Recent evidences reveal that epithelial to mesenchymal transition (EMT) exacerbates the process of intestinal fibrosis. Tumor necrosis factor-like ligand 1A (TL1A) is a member of the tumor necrosis family (TNF), which can take part in the development of colonic inflammation and fibrosis by regulating immune response or inflammatory factors. The purpose of this study was to elucidate the possible contribution of TL1A in onset and progression of intestinal inflammation and fibrosis through EMT.

METHODS

Colonic specimens were obtained from patients with inflammatory bowel disease (IBD) and control individuals. The expression levels of TL1A and EMT-related markers in intestinal tissues were evaluated. Furthermore, the human colorectal adenocarcinoma cell line, HT-29, was stimulated with TL1A, anti-TL1A antibody, or BMP-7 to assess EMT process. In addition, transgenic mice expressing high levels of TL1A in lymphoid cells were used to further investigate the mechanism of TL1A in intestinal fibrosis.

RESULTS

High levels of TL1A expression were detected in the intestinal specimens of patients with ulcerative colitis and Crohn's disease and were negatively associated with the expression of an epithelial marker (E-cadherin), while it was positively associated with the expression of interstitial markers (FSP1 and α-SMA). Transgenic mice with high expression of TL1A were more sensitive to dextran sodium sulfate and exhibited severe intestinal inflammation and fibrosis. Additionally, the TGF-β1/Smad3 pathway may be involved in TL1A-induced EMT, and the expression of IL-13 and EMT-related transcriptional molecules (e.g., ZEB1 and Snail1) was increased in the intestinal specimens of the transgenic mice. Furthermore, TL1A-induced EMT can be influenced by anti-TL1A antibody or BMP-7 in vitro.

CONCLUSIONS

TL1A participates in the formation and process of EMT in intestinal fibrosis. This new knowledge enables us to better understand the pathogenesis of intestinal fibrosis and identify new therapeutic targets for its treatment.

Protein-Degrading Enzymes in Osteoarthritis

OBJECTIVE

TGFβ1 plays an important role in the metabolism of articular cartilage and bone; however, the pathological mechanism and targets of TGFβ1 in cartilage degradation and uncoupling of subchondral bone remodeling remain unclear. Therefore, in this study, we investigated the relationship between TGFβ1 and major protein-degrading enzymes, and evaluated the role of high levels of active TGFβ1 in the thickening of subchondral bone and calcification of articular cartilage.

MATERIALS AND METHODS

The expression of TGFβ1 and protein-degrading enzymes in clinical samples of articular cartilage and subchondral bone obtained from the knee joint of patients with osteoarthritis was detected by immunohistochemistry. The expression levels of TGFβ1, MMP-3, MMP-13 and IL-1β in cartilage and subchondral bone tissues were detected by absolute real-time quantitative RT-PCR. The expression of TGFβ1, nestin and osterix in subchondral bone was detected by Western blot analysis and immunohistochemistry. The degree of subchondral bone thickening was determined by micro-computed tomography (CT) imaging.

RESULTS

Expression of TGFβ1 and cartilage-degrading enzymes was higher in the cartilage-disrupted group than that in the intact group. Furthermore, expression of TGFβ1, nestin and osterix was significantly higher in the OA group than that in the control group. Micro-CT imaging showed that in the OA group, the subchondral bone plate is thickened and the density is increased. The trabecular bone structure is thick plate-like structure, the thickness of the trabecular bone is increased and the gap is small.

CONCLUSIONS

The data suggest that highly active TGFβ1 activates the expression of cartilage-degrading enzymes. Abnormally activated TGFβ1 may induce formation of the subchondral bone and expansion of the calcified cartilage area, eventually leading to degradation of the cartilage tissue.

Cultivation and Harvesting of Selenium-Enriched Ganoderma lingzhi and Spent Medium Using Kudzu Vine as Substrate

In order to harvest selenium-enriched fruiting body and spores of Ganoderma lingzhi and spent medium, G. lingzhi was cultivated in kudzu vine as substrate and the bio-transformation of selenite was evaluated. The growth medium consisted of Kudzu vine supplemented with 20% wheat bran or sawdust or none. The growth medium was supplemented with 0, 10, 20, 30, and 50 mg/kg of sodium selenite. We found a significant difference in spawn run speed, fruiting body and spore yields when Kudzu vine was supplemented with wheat bran or sawdust. However, when whole-kudzu vine was used alone as substrate, it resulted in a significantly lower spawn run speed, fruiting body, and spore yields compared with kudzu vine + sawdust substrate and kudzu vine + wheat bran substrate. The selenium content in fruiting body and spores increased with increasing sodium selenite supplementation and approximately equaled half of the selenium in the substrate. No selenite was detected in both the fruiting body and spores. However, in the spent medium when sodium selenite was supplemented at 10, 20, 30, 50 mg/kg, the residual selenite concentration decreased to 0.45, 0.72, 1.29, and 1.95 mg/kg, respectively, suggesting a higher selenite transformation (92.27–93.57%). In conclusion, if Ganoderma fruiting body and spores were to be harvested for human consumption, approximately 50 mg/kg selenite should be added to the growth substrate. On the other hand, if the spent medium was to be used as an organic selenium source, the optimal sodium selenite supplementation level would be 10 mg/kg.

A Novel Detection Method for Appetite Suppressants Illegally Added into Weight-Loss-Friendly Foods

Weight-loss-friendly foods are often adulterated illegally with appetite suppressants. Therefore, there is an urgent need for effective and reliable methods for the detection of food adulteration. To this end, we have developed a novel detection system called high-performance liquid chromatography-tandem quadrupole time of flight mass spectrometry capable of separation and detection of adulterants as low as 0.03 μg/kg. This method describes all the necessary separation and detection parameters required for the high-throughput detection of simultaneously added multiple suppressants in foods.

Analysis of Spino-pelvic Sagittal Alignment in Young Chinese Patients with Lumbar Disc Herniation

OBJECTIVE

Few studies have concentrated on the sagittal alignment of lumbar disc herniation (LDH), especially the parameters of the pelvis, and controversy exists about whether pelvic morphology is involved in the pathogenesis of LDH. The present study analyzed the characteristics of the sagittal alignment in young Chinese LDH patients and explored the impact of pelvic morphology on the pathogenesis of LDH.

METHODS

A retrospective analysis was conducted on 100 young patients with LDH (69 men and 31 women, aged 18-35 years), and the clinical and imaging findings met the criteria for the diagnosis of LDH. The control group included 100 asymptomatic volunteers with matching age and gender. Coronal and sagittal parameters were measured on the anteroposterior and lateral radiographs of the whole spine, including lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), thoracic kyphosis (TK), and sagittal balance (SVA). The cases were classified into four types by the apex position of lumbar lordosis (type I, L₅ or the L_4-5 intervertebral space; type II, bottom or middle of L₄ ; type III, upper part of L₄ or the intervertebral space between L₃ and L₄ ; type IV, L₃ or more high level), and divided into three groups by PI; namely, a low PI group (PI < 40°), a medium PI group (40° ≤ PI < 50°), and a high PI group (PI ≥ 50°). The sagittal parameters, especially PI, were compared between the LDH group and the control group. Correlations between the parameters in the LDH group were analyzed.

RESULTS

The PI value of the LDH group was not different from that of the control group (46.1° ± 10.0° vs 47.2° ± 8.8°, P > 0.05). The LDH group showed lower average LL, SS, and TK (P < 0.01), as well as higher PT and SVA compared with the control group (P < 0.01). The LL (34.4° ± 15.3° vs 50.8° ± 10.2°) and SVA (21.6 ± 53.6 mm vs - 18.4 ± 32.8 mm) showed a significant difference (P < 0.01); LL was correlated with PI, SS, PT, TK and SVA (P < 0.01); and SVA was also correlated with the parameters above (P < 0.01) except PI (P > 0.05), and the lordosis apex tended to be higher. The distributions of PI groups between the LDH group and the control group were not different. Pairwise correlations were found among LL, PI, SS, and PT. In addition, TK and SVA were correlated with LL, SS, and PT.

CONCLUSIONS

There is no difference in PI between young Chinese patients with lumbar disc herniation and the normal population. Young LDH patients may present flat lumbar and thoracic curves, as well as lower sacral slope. The anteversion sagittal imbalance is regulated by both the spine and the pelvis.

Effect of patient position on the lordosis and scoliosis of patients with degenerative lumbar scoliosis

This study aimed to analyze the effect of patient positions on the lordosis and scoliosis of patients with degenerative lumbar scoliosis (DLS).Seventy-seven patients with DLS were retrospectively analyzed. We measured lordosis and Cobb's angle on preoperative upright x-rays and magnetic resonance imagings in supine position. The lordosis and scoliosis of surgical segments in intraoperative prone position were measured on intraoperative radiographs of 20 patients to compare with that in standing position. Paired t tests were performed to investigate the parameters of the sample.From standing to supine position the whole lordosis increased (29.2 ± 15.7 degree vs. 34.9 ± 11.2 degree), and the whole scoliosis decreased (24.3 ± 11.8 degree vs. 19.0 ± 10.5 degree); 53 of 77 (68.8%) cases had increased lordosis, and 67 of 77 (87%) cases had decreased scoliosis. The lordosis of surgical segments in standing position had no difference with that in intraoprerative prone position. But in changing from supine/standing position to intraoprerative prone position, the scoliosis of surgical segments decreased (14.7 ± 9.4 degree vs. 11.4 ± 7.0 degree; 19.0 ± 11.8 degree vs. 11.4 ± 7.0 degree, respectively), and 18 of 20 (90%) cases had decreased scoliosis in intraoperative prone position than that in standing position.Compared with standing position in DLS patients, supine position increased lordosis and reduced scoliosis, and intraoperative prone position reduced scoliosis significantly. When evaluating the severity of DLS and making preoperative surgical plans, lumbar lordosis in supine position should also be evaluated in addition to upright x-ray, and the effects of different positions should be taken into consideration to reduce deviation.

Chorea and parkinsonism associated with autoantibodies to IgLON5 and responsive to immunotherapy

Encephalopathy associated with autoantibodies to IgLON5 is a novel syndrome characterized by a distinct sleep disorder and brain-stem involvement. Since the initial description of this encephalopathy in 2014, only a few additional patients have been reported (Simabukuro et al., 2015). In this paper, we report a new case of anti-IgLON5 antibodies with major symptoms of chorea and parkinsonism, and responsive to immunotherapy.

Characterization of core-shell MOF particles by depth profiling experiments using on-line single particle mass spectrometry

Materials with core-shell structures have distinct properties that lend themselves to a variety of potential applications. Characterization of small particle core-shell materials presents a unique analytical challenge. Herein, single particles of solid-state materials with core-shell structures were measured using on-line aerosol time-of-flight mass spectrometry (ATOFMS). Laser 'depth profiling' experiments verified the core-shell nature of two known core-shell particle configurations (<2 μm diameter) that possessed inverted, complimentary core-shell compositions (ZrO2@SiO2 versus SiO2@ZrO2). The average peak area ratios of Si and Zr ions were calculated to definitively show their core-shell composition. These ratio curves acted as a calibrant for an uncharacterized sample – a metal-organic framework (MOF) material surround by silica (UiO-66(Zr)@SiO2; UiO = University of Oslo). ATOFMS depth profiling was used to show that these particles did indeed exhibit a core-shell architecture. The results presented here show that ATOFMS can provide unique insights into core-shell solid-state materials with particle diameters between 0.2-3 μm.

An evaluation comparing Californium252 neutron brachytherapy with neoadjuvant intra-arterial embolism chemotherapy assisted surgery effect for treating advanced cervical carcinoma patients

PURPOSE OF INVESTIGATION

To compare the therapeutic and side effects of using Californium252 (252Cf) neutron brachytherapy with neoadjuvant intra-arterial embolism chemotherapy in combination with surgery for treating Stage Ib2-IIb cervical cancers (CCs).

MATERIALS AND METHODS

Thirty-two Stage Ib2-IIb CC patients were enrolled and randomly divided into two groups from January 2007 to April 2010 in the present Hospital. Prior to surgery within four weeks, a total of 17 cases were treated with 252Cf neutron brachytherapy (700-800 cGy doses at point A) once a week (Group A), and 15 cases were treated by neoadjuvant intra-arterial embolism chemotherapy using a combination of bleomycin, carboplatin, and cyclophosphamide twice (Group B). The clinical symptoms and signs, side effects, and relapse condition follow up until July 2013 were compared between the two groups for the perioperation.

RESULTS

Reductions in tumor mass and CR+PR were not significantly different between the groups before the surgery (p > 0.05). Abdominal pain and pelvic adhesions were significantly more severe in Group B (p < 0.05). There were no significant differences in surgical time, blood loss or the other side effects between Groups A and B (p > 0.05). The percentage of pelvic tumor recurrences in Group A was lower than that of the patients in Group B (11.8% vs 20.0%) although with no significant difference at present. No distant metastasis has been found in both two groups.

CONCLUSION

Except for less abdominal pain and pelvic adhesions, 252Cf neutron brachytherapy has perioperative effects similar to those of neoadjuvant intra-arterial embolism chemotherapy.

IL-1beta caused pancreatic beta-cells apoptosis is mediated in part by endoplasmic reticulum stress via the induction of endoplasmic reticulum Ca2+ release through the c-Jun N-terminal kinase pathway

Endoplasmic reticulum (ER) homeostasis is crucial for beta-cell function and survival. Direct as well as indirect evidence has pointed toward Ca(2+) as an important determinant of interleukin-1beta (IL-1beta)-induced beta-cell dysfunction and apoptosis. In the present study, we show that IL-1beta-induced apoptosis and necrosis in primary rat beta-cells and MIN6 cells largely depends on ER stress, ER Ca(2+) release, and c-Jun N-terminal kinase (JNK) activation. beta-cells also showed marked sensitivity to apoptosis induced by sarcoendoplasmic reticulum Ca(2+) ATPase (SERCA) blockers, thapsigargin and cyclopiazonic acid (CPA). IL-1beta induced ER Ca(2+) release, which was paralleled by an IL-1beta-dependent induction of JNK activation and the ER stress response, including activation of PRK (RNA-dependent protein kinase)-like ER kinase (PERK). Furthermore, reduced activation of JNK, utilizing JNK inhibitor SP600125, resulted in significant protection from IL-1beta- or thapsigargin-induced apoptosis via ER stress. In conclusion, our results suggest that the IL-1beta-induced depletion of ER Ca(2+) and activation of the ER stress via JNK pathway are potential contributory mechanisms to beta-cell death.

The Inhibitory Activities of Recombinant Eglin C Mutants on Kexin and Furin, Using Site-directed Mutagenesis and Molecular Modeling

Mammalian furin and yeast kexin are members of the proprotein convertase family involved in the proteolytic processing of many important precursor proteins. Here the gene coding for the subtilisin inhibitor eglin C was totally synthesized and expressed in E.coli. Substitution of residues at each position P(1), P(2) and P(4) of eglin C with a basic residue using protein engineering could make eglin C a very strong inhibitor for furin (K(i) around 10(-9) mol/L),and even more strong for kexin (K( i ) around 10(-11) mol/ L). Results indicated that (1) A basic residue Lys or Arg at P(1) site is prerequisite for the inhibitor. (2) The second mutation with basic residue at P(4) site drastically increase the inhibitory activity by two orders of magnitude. (3) A basic residue at P(2) site is favorable for the binding to the enzyme, but unfavorable for the stability of the inhibitor, resulting in a temporary inhibition. (4) A hydrophobic residue is preferential at P(3) site. Based on the known crystal structures of subtilisin and eglin C, the interaction between the enzyme and inhibitor was modeled, and their involved residues were predicted which gave a good explanation to the experimental results.

Rotating annulus experiment: large-scale helical soliton in the atmosphere?

A typhoon is a cyclone vortex with a warm low pressure center, formed over tropical oceanic waters. A large-scale rotating annulus experiment of fluid dynamics is carried out, under the conditions of dynamic similarity, geometric similarity, and the similarity of boundary conditions. In the first step, with the help of infrared heaters, the basic flow field and helical structure of a single typhoon were successfully simulated; then two model typhoons were generated, and their interactions tested. It demonstrated that they did separate after colliding with each other, and their respective basic shapes were restored, which confirms the basic dynamic features of typhoons in nature as solitons. It was also shown that the formation of their helical structures is related to the adapting process of atmosphere to the rotation of the earth and that their dynamic characteristics as solitons come from a result of an equilibrium between their dispersion and the nonlinear convergence of the anticyclones, with whose combined actions their structure remains stable for a long period, which in turn means that they are indeed three-dimensional helical solitons.

Formulation and pharmacokinetic studies of acyclovir controlled-release capsules

Acyclovir controlled-release capsules (CRCs) were prepared by a three-step process: (1) melt granulation of acclovir; (2) coating of granules with ethyl-cellulose, (3) incorporation of coated granules into hard gelatin capsules. In vitro release experiments showed that the main factors affecting the release rate were the mean particle size of the actylovir raw material and the amount of coating material applied. Release of acyclovir from the capsules was in accordance with the Higuchi equation. Pharmacokinetic studies in dogs after oral administration of acyclovir controlled-release capsules showed that the formulation was successful in providing slow release of aciclovir and was superior to a commercially available controlled-release formulation.

Evaluation of vetiver oil and seven insect-active essential oils against the Formosan subterranean termite

Repellency and toxicity of 8 essential oils (vetiver grass, cassia leaf, clove bud, cedarwood, Eucalyptus globules, Eucalyptus citrodora, lemongrass and geranium) were evaluated against the Formosan subterranean termite, Coptotermes formosanus Shiraki. Vetiver oil proved the most effective repellent because of its long-lasting activity. Clove bud was the most toxic, killing 100% of termites in 2 days at 50 micrograms/cm2. The tunneling response of termites to vetiver oil also was examined. Vetiver oil decreased termite tunneling activity at concentrations as low as 5 micrograms/g sand. Tunneling and paper consumption were not observed when vetiver oil concentrations were higher than 25 micrograms/g sand. Bioactivity of the 8 oils against termites and chemical volatility were inversely associated. Listed in decreasing order of volatility, the major constituents of the 8 oils were: eucalyptol, citronellal, citral, citronellol, cinnamaldehyde, eugenol, thujopsene, and both alpha- and beta-vetivone. Vetivor oil is a promising novel termiticide with reduced environmental impact for use against subterranean termites.

Salivary non-immunoglobulin agglutinin inhibits human leukocyte elastase digestion of acidic proline-rich salivary proteins

Saliva contains acidic proline-rich salivary proteins that are involved in the formation of the salivary pellicle coating supragingival tooth surfaces. However, human leukocyte elastase, arriving in gingival exudates from inflamed periodontal tissues, degrades the acidic proline-rich salivary proteins, preventing binding to hydroxylapatite surfaces. Here it is reported that high-molecular-weight non-immunoglobulin salivary agglutinin inhibited the proteolytic action of human leukocyte elastase on purified acidic proline-rich salivary proteins. Inhibition was eliminated with monoclonal antibody to a protein determinant on the salivary agglutinin. The addition of antibody against salivary agglutinin blocked the inhibitory effect of parotid saliva on exogenously applied human leukocyte elastase, allowing for the elastase-mediated digestion of the salivary acidic proline-rich salivary proteins. Salivary agglutinin, therefore, is a physiologically important inhibitor of human leukocyte elastase and is able to inhibit elastase-mediated digestion of salivary acidic proline-rich proteins.

Evaluation of two different homogeneous assays for LDL-cholesterol in lipoprotein-X-positive serum

BACKGROUND

The purpose of this study was to evaluate the performance of two homogeneous assays for LDL-cholesterol (LDL-C), a polyethylene/cyclodextrin (PC) assay and a detergent (D) assay, which are based on different principles, in cholestatic serum.

METHODS

We compared serum LDL-C concentrations determined by the two assays for healthy normolipidemic subjects (n = 42) and cholestatic patients (n = 51). LDL-C concentrations obtained with the homogeneous assays were also compared with those obtained by HPLC for patients' sera. In the interference study, conjugated bile acids were added to normal serum, and their effects on the two assays were examined. The effects of lipoprotein-X (LP-X), intermediate-density lipoprotein (IDL), and apolipoprotein (apo) E-rich HDL on the LDL-C assays were also investigated by adding these lipoproteins to normal serum.

RESULTS

The LDL-C concentrations obtained with the D assay were higher than those obtained with the PC assay in the serum with high LP-X. The bias for LDL-C vs LP-X in cholestatic serum correlated with LP-X concentration (r = 0.582; P: <0.0001; n = 51). In the interference study, no effect of bile acids on the LDL-C assays was observed. However, the D assay measured 51.0% of the cholesterol in LP-X, whereas no reactivity was observed for LP-X in the PC assay. In addition, the D assay and the PC assay measured IDL-cholesterol at 31.2% and 52.4%, respectively, and measured apo E-rich HDL-C at 7.6% and 17.8%, respectively.

CONCLUSIONS

Although both homogeneous LDL-C assays are suitable for most cases, the present study showed that each homogeneous assay has a different limitation for cholestatic serum with gross alterations in lipoproteins.

[Chemosensitivity test for 170 human breast carcinoma samples]

We tested the in vitro sensitivity of 170 primary breast carcinoma samples to the anti-cancer drugs conventionally used in clinical chemotherapy. It was found that: 1. The high sensitivity rate (HSR) of breast carcinoma cells to 5-fluorouracil (5-Fu), mitomycin (MMC), cisplatin (DDP), adriamycin(ADM), methotrexate(MTX), vincristin(VCR), vepesid(VP-16), taxol, and vindesine(VDS) were 57.1%, 49.4%, 48.3%, 35.8%, 21.8%, 21.2%, 10%, 18.2% and 20.9%, respectively. The increase of HSR of cancer cells to 5-Fu, MMC, DDP, taxol was more significant than that of the other drugs tested (P < 0.05). 2. No correlation was shown between drug sensitivity and factors, i.e. pathological type, clinical type, expression of estrogen receptor (ER) and epithelium growth factor receptor(EGFR) for breast carcinoma (P > 0.05). 3. Cyclosporin A can increase part of the sensitivity of ADM-resistant breast carcinoma cells to ADM.

Nonhistone protein purified from porcine kidney acts as a suicide substrate inhibitor on furin-like enzyme

AIM

To search and purify a naturally occurring protein inhibitor of the furin-like enzyme from the porcine kidney.

METHODS

Recombinant kexin, a furin-like enzyme, from the yeast secretion expression was used as a target enzyme. The inhibitor component was extracted and purified from the acetone powder of porcine kidney. The inhibitory activity was monitored using a fluorogenic peptide substrate Boc-Arg-Val-Arg-MCA at spectrofluorimeter.

RESULTS

The purified inhibitor component is a basic protein with an isoelectric point over 9.5. Its partial N-terminal sequence of 22 residues was determined, showing a high homology with nonhistone chromosomal protein HMG-17 in which there are four sites composed of dibasic residues, susceptible to be cleaved by the furin-like enzyme. This nonhistone protein could strongly compete with the fluorogenic substrate. However, this nonhistone protein would be degraded as a substrate by kexin if it was incubated with the enzyme for long time before adding the fluorogenic substrate, and subsequently lost its temporary inhibitory activity.

CONCLUSION

The nonhistone protein isolated from the porcine kidney functioned as a suicide substrate inhibitor for the furin-like enzyme.

Molecular characterization of a new excitatory insect neurotoxin with an analgesic effect on mice from the scorpion Buthus martensi Karsch

Besides the neurotoxins active on mammals, a new excitatory insect selective toxin with a mice analgesic activity was found and purified from the venom of the scorpion Buthus martensi Karsch (BmK) (Ji, Y.H., Mansuelle, P., Terakawa, S., Kopeyan, C., Yanaihara, N., Hsu, K., Rochat, H., 1996. Toxicon 34, 987; Luo, M.J., Xiong, Y.M., Wang, M., Wang, D.C., Chi, C.W., 1997. Toxicon 35, 723.). This peptide (designated as BmK IT-AP) is composed of 72 amino acid residues. Its primary structure was determined by automated Edman degradation of the N-terminal part of the reduced and S-carboxamidemethylated protein and its lysylendopeptidase degraded fragments. Based on the determined sequence, the gene specific primers were designed and synthesized for 3' and 5' RACE (rapid amplification of cDNA ends). Their partial cDNA fragments obtained by 3' and 5' RACEwere cloned and sequenced and the full length cDNA sequence of BmK IT-AP was then completed by overlapping their two partial cDNA sequences. It encodes a precursor of 90 amino acid residues: a signal peptide of 18 residues and a mature peptide of 72 residues which are consistent with the determined protein sequence of BmK IT-AP. The genomic DNA of the peptide was also amplified by PCR from the scorpion genomic DNA and sequenced, which is a first report on the genomic structure of a scorpion toxin specific for insects. Its sequence revealed an intron of 590 bp inserted in the end part of the signal peptide. The peptide caused a fast excitatory contraction paralysis on house fly larvae. Furthermore, the peptide also showed an obvious analgesic effect on mice, as assayed by using a twisting test model. This effect of BmK IT-AP well characterized at molecular level is first reported among the known scorpion insect neurotoxins.

A rapid screening and diagnosis on fragile X syndrome by PCR

Polymerase chain reaction (PCR) technique combined with direct detection by silver staining on denaturing DNA sequencing gel was used to analyze the (CGG)n repeats within the FMR1 gene on 169 suspected patients with mental retardation and 33 kindreds of 6 fragile X families. The results showed that: (1) No PCR products were detected in 3 males in the suspected group. (2) In the fragile X family studies, the 5 male probands failed to show any PCR products. (3) Diplex PCR with the primers flanking the FRAXE locus was used to serve as an internal control for the 8 above-mentioned males and only normal products of the FRAXE locus were detected, indicating that the possibility of false negative results of the FRAXA locus could be eliminated. These findings suggested that analysis of (CGG)n repeat within the FMR1 gene by PCR technique could efficiently detect premutation carriers and that negative PCR products in mentally retarded males might highly imply the diagnosis of fragile X syndrome after the false negative results have been excluded by diplex PCR. This PCR assay is suitable for the screening and diagnosis of fragile X syndrome in a large number of populations due to its rapidity, simplicity, stability and reliability.

[Detection of minimal residual disease in acute lymphoblastic leukemia using PCR-molecule hybridization of RNA transcripts]

OBJECTIVE

To detect acute lymphoblastic leukemia's(ALL's) minimal residual disease(MRD) rapidly and effectively.

METHODS

In this assay, the gamma T-cell receptor gene rearrangements serve as marker genes. The gene rearrangements are amplified from the diagnostic specimens using a consensus V segment primer and a consensus J segment primer to which the promoter T7 RNA polymerase has been appended. The PCR product from this amplification is transcribed into a radiolabeled RNA probe. The opposite DNA strand is transcribed into test RNA from the PCR product of different staged specimens. The test RNA is hybridized with the probe, and later the digestion with RNase A, Polyacrylamide gel electrophoresis and autoradiography are in progress.

RESULTS

According to the mechanism, the perfectly matched RNA duplex can prevent the digestion of RNase A, and the presence of the leukemia cells in the test specimen can be determined. Logarithmical dilution experiments with DNA of a cell line from ALL have shown that this assay's sensitivity is at the 10(-5) level. Minimal residual disease was successfully detected in a case of ALL during its complete remission stage. But if the probe and test RNA are not from the same individual, the results of this kind of cross hybridization are negative.

CONCLUSION

The above results suggest that this assay can become an effective measure in the detection of ALL-MRD clinically.

Detection of minimal leukemic cells in cerebral spinal fluid of children with acute lymphoblastic leukemia using the polymerase chain reaction technique

V delta 2D delta 3 rearrangements of T cell receptor (TCR) gene from cerebral-spinal fluid (CSF) cells was detected for diagnosis and monitoring of central nervous system leukemia (CNSL) in children with acute lymphoblastic leukemia (ALL) using polymerase chain reaction (PCR) technique. 20 patients were studied and in 12 of them the results of PCR and dot hybridization with clonospecific probes were positive, showing the presence of minimal blast cells in CSF. Our study suggested that the PCR method is an effective tool for clinical diagnosis of CNSL and is much more sensitive than routine CSF examination.

Anatomic localization of alternatively spliced leptin receptors (Ob-R) in mouse brain and other tissues

Leptin's effects are mediated by interactions with a receptor that is alternatively spliced, resulting in at least five different murine forms: Ob-Ra, Ob-Rb, Ob-Rc, Ob-Rd, and Ob-Re. A mutation in one splice form, Ob-Rb, results in obesity in mice. Northern blots, RNase protection assays, and PCR indicate that Ob-Rb is expressed at a relatively high level in hypothalamus and low level in several other tissues. Ob-Ra is expressed ubiquitously, whereas Ob-Rc, -Rd, and -Re RNAs are only detectable using PCR. In hypothalamus, Ob-Rb is present in the arcuate, ventromedial, dorsomedial, and lateral hypothalamic nuclei but is not detectable in other brain regions. These nuclei are known to regulate food intake and body weight. The level of Ob-Rb in hypothalamus is reduced in mice rendered obese by gold thioglucose (GTG), which causes hypothalamic lesions. The obesity in GTG-treated mice is likely to be caused by ablation of Ob-Rb-expressing neurons, which results in leptin resistance.

Impact mass chemotherapy with praziquantel on schistosomiasis control in Fanhu village, People's Republic of China

The paper describes the endemic situation of schistosomiasis japonica in Fanhu village, Poyang Lake region, China and the effect of the strategy of combining annual mass chemotherapy with health education on schistosomiasis control in the community. The results showed that the prevalence of infection with schistosome reduced form 26.0% in 1992 to 10.7% in 1994, the intensity of infection in residents decreased from 1.92 in 1992 to 0.55 in 1994 and the condition of hepatomegaly, splenomegaly and liver fibrosis also improved after chemotherapy in the individuals in the case prospective study. Moreover, the future strategies of schistosomiasis control in this area have been suggested according to the transmission of schistosomiasis in the lake region and the effect of anti-schistosomiasis control indifferent populations.

Termination of reentry by lidocaine in the tricuspid ring in vitro. Role of cycle-length oscillation, fast use-dependent kinetics, and fixed block

We hypothesized that drugs with rapid recovery kinetics from use-dependent sodium channel block could promote oscillatory termination of reentry by enhancing interval-dependent conduction. Mechanisms of termination were related to properties of the reentrant circuit. Nine adjustable reentrant preparations were used in which the canine atrial tricuspid ring was cut and then reconnected electronically by sensing activation on one side of the cut and pacing the other after an adjustable delay. The cycle length and diastolic interval during reentry were manipulated by changing this delay. Lidocaine (1.28 x 10(-5) mol/L) significantly increased refractoriness (94 +/- 39 ms) and the slope of the conduction curve (-0.12 +/- 0.07) at the site of block during pacing. Lidocaine terminated sustained reentry by two mechanisms. Early termination resulted from increased cycle length oscillation and refractoriness (reproducible in each experiment) but only at short delays with short initial diastolic intervals. The range of delays showing this mechanism of termination was 100 +/- 48 ms. Increased cycle-length oscillation resulted from an increased slope of the conduction curve. In eight experiments, lidocaine terminated reentry by causing fixed block after 50 minutes of drug superfusion, which prevented reentry at all delays. Fixed block occurred at one of two vulnerable sites and was transiently reversed by acetylcholine. Termination due to refractory block occurred only when the initial diastolic interval was short, and termination due to fixed block developed when there was a susceptible region with a low safety factor for propagation. Fast recovery from sodium channel block promotes oscillatory termination by increasing the slope of the conduction curve.

Assessing the excitable gap in reentry by resetting. Implications for tachycardia termination by premature stimuli and antiarrhythmic drugs

BACKGROUND

The shortest excitable gap during reentry may determine responses to pacing and antiarrhythmic drugs. The resetting response has been used clinically to assess the excitable gap, but it cannot directly indicate the shortest excitable gap.

METHODS AND RESULTS

We studied resetting in the in vitro canine atrial tricuspid ring using an adjustable reentry preparation in which the ring was cut and reconnected electronically with an adjustable delay to vary the cycle length and excitable gap. We reset the tachycardias using 31 delays in 12 experiments. Tachycardias were terminated by premature stimuli in 16 delays. The reset window overestimated the shortest excitable gap by 25 +/- 14 ms, and the maximum degree of advancement of tachycardia underestimated the shortest excitable gap by 22 +/- 11 ms. The slope of the increasing portion of the resetting response curve was steeper in tachycardias terminated by premature stimuli than in those not terminated (-0.69 +/- 0.2 versus -0.37 +/- 0.2, P < .01). The effective refractory period difference between the sites of pacing and of block correlated with the slope of the resetting response curve. Damped cycle length oscillation after a long return cycle during resetting was always present when there was a partially excitable gap.

CONCLUSIONS

The reset window during pacing within the circuit and the maximum degree of advancement provided equally good estimates bracketing the shortest excitable gap. The slope of the resetting response curve predicted the likelihood of termination by premature stimuli. Damped cycle length oscillation after resetting detected a partially excitable gap.

Reversal of reentry and acceleration due to double-wave reentry: two mechanisms for failure to terminate tachycardias by rapid pacing

OBJECTIVES

We sought to demonstrate mechanisms by which rapid pacing can cause conduction block without terminating reentry.

BACKGROUND

Rapid pacing can fail to terminate or can accelerate tachycardias in patients. Mechanisms for these responses are poorly understood.

METHODS

We studied reentry in the canine atrial tricuspid ring and a left ventricular ring in vitro in 12 preparations. Activations were recorded from 10 sites around the ring, and monophasic action potentials were recorded from critical sites of block. Rapid pacing at cycle lengths that intermittently caused conduction block was performed at multiple sites.

RESULTS

Action potential alternans contributed to block of an orthodromic impulse during rapid pacing. When pacing continued for two stimuli after orthodromic block, a second episode of block could reverse the direction of tachycardia. Continued pacing at this site was likely to produce block of an antidromic impulse, which may initiate double-wave reentry. Double-wave reentry could be sustained or nonsustained. Its cycle length was 56% to 77% of the single-wave cycle length. The ratio of double-wave cycle length to single-wave cycle length was inversely correlated with the relative excitable gap (p < 0.01). Double-wave reentry can be a mechanism for persistent cycle length alternation during tachycardia.

CONCLUSIONS

Successful termination of reentry by rapid pacing required block of an othrodromic impulse and stopping pacing within one stimulus after orthodromic block. Reversal of reentry makes the circuit resistant to termination from this site of pacing. Antidromic block can cause acceleration due to double-wave reentry when there is a substantial excitable gap.

d-Sotalol terminates reentry by two mechanisms with different dependence on the duration of the excitable gap

We used eight adjustable preparations in which the canine atrial tricuspid rings were cut and reconnected electronically by sensing activation on one side of the cut and pacing the other after an adjustable delay. A long delay resulted in a long cycle length (CL) and excitable gap (EG) during reentry. Decreasing delay decreased CL and EG. d-Sotalol (4 mg/l) significantly increased effective refractory period (ERP) and action potential duration with no effects on conduction time during constant 400-msec pacing. During reentry, d-sotalol increased action potential durations more than CLs, so it decreased diastolic intervals. It decreased EG by increasing ERP more than CL. Although d-sotalol increased action potential duration more at longer delays with longer CLs, showing reverse use-dependence, it terminated sustained tachycardias by increasing ERP only for the short delays when the initial EG was short. In 5 of 8 experiments, longer equilibration with d-sotalol produced fixed block at a vulnerable site, so reentry could not be induced at any delays. Fixed block could be transiently reversed by ACh and resolved after washout of d-sotalol. We conclude that d-sotalol terminated reentry by two mechanisms: 1) It terminated sustained reentry by increasing ERP when the initial EG was sufficiently short. 2) In some preparations, it caused fixed block at a vulnerable site, which prevented reentry regardless of the initial EG.