[From treatment to whole course management: envisioning comprehensive management of Talaromycosis marneffei]

Talaromycosis marneffei has been increasing in recent years. Our understanding of this disease has gradually deepened through extensive basic and clinical research, but there are still many limitations. In this article, by incorporating the latest research advancements, we discuss important issues in managing Talaromycosis marneffei trends, aiming to guide effective prevention and control of the disease, improving public health, and reducing the healthcare burden.

Active kisspeptin DNA vaccines oral immunization disrupt mRNA hormone receptors expression in ram lambs

To evaluate the efficacy of oral immunization with active kisspeptin DNA vaccine on the expression of hormone receptor mRNA. For this study, ten 56-day-old Hu breed ram lambs were randomly assigned to the treatment and control groups (n = 5). Treatment Experimental group received C500/pKS-asd and the control group received C500/pVAX-asd (aspartate-β semialdehyde dehydrogenase orally on days 0, 28, and 56, and blood samples were taken at each immunization interval (14-day) and tissues samples were collected at the end of the experimental period (day 98). The collected samples were stored in the refrigerator at -20 °C and liquid nitrogen, respectively, for laboratory examination. Total RNA was extracted from samples using TRIzol reagent and quantitative real-time polymerase chain reaction (QPCR) was used to quantify the levels of KISS1, G protein-coupled receptor-54 (Kiss1r), and gonadotrophin-releasing hormone (GnRH) mRNA in the hypothalamus. Levels of luteinizing hormone receptor (LHR) and luteinizing hormone beta (LHβ) mRNA, and follicle-stimulating hormone receptor (FSHR) and follicle-stimulating hormone beta (FSHβ) mRNA in the testes and pituitary were analyzed, respectively. Further, gonadotropin-releasing hormone receptor (GnRHR) mRNA expression level in the pituitary was measured. Moreover, the Kiss1r concentration level in the blood was measured using an indirect ELISA. The concentration of Kiss1r in the blood was lower in the treatment group than in the control group (p < 0.05). The levels of testicular FSHR and LHR mRNA were significantly lower in the treatment group (p < 0.05) when compared to the control group. Furthermore, the treatment group's levels of hypothalamic KISS1, Kiss1r, and GnRH mRNA were significantly lower (p < 0.05) than the controls. LH, FSH, and GnRHR mRNA expression in the pituitary were also significantly lower in the treatment group (p < 0.01 and p < 0.05, respectively). These findings imply that oral immunization with active kisspeptin DNA vaccine suppresses hormone receptor mRNA expression in the ram lambs.

[Bendamustine combined with pomalidomide and dexamethasone in relapsed multiple myeloma with extramedullary disease: a multicenter study]

Objective: To evaluate the efficacy and safety of bendamustine combined with pomalidomide and dexamethasone (BPD regimen) in the treatment of relapsed multiple myeloma (MM) with extramedullary disease. Methods: This open, single-arm, multicenter prospective cohort study included 30 relapsed MM patients with extramedullary disease diagnosed in seven hospitals including Qingdao Municipal Hospital. The patients were treated with BPD regimen from February 2021 to November 2022. This study analyzed the efficacy and adverse reactions of the BPD regimen. Results: The median age of the 30 patients was 62 (47-72) years, of which 18 (60% ) had first-time recurrence. The overall response rate (ORR) of the 18 patients with first-time recurrence was 100%, of which three (16.7% ) achieved complete remission, 10 (55.5% ) achieved very good partial remission (VGPR), and five (27.8% ) achieved partial remission (PR). The ORR of 12 patients with recurrence after second-line or above treatment was 50%, including zero patients with ≥VGPR and six patients (50% ) with PR. Three cases (25% ) had stable disease, and three cases (25% ) had disease progression. The one-year progression free survival rate of all patients was 65.2% (95% CI 37.2% -83.1% ), and the 1-year overall survival rate was 90.0% (95% CI 76.2% -95.4% ). The common grade 3-4 hematology adverse reactions included two cases (6.7% ) of neutropenia and one case (3.3% ) of thrombocytopenia. The overall adverse reactions are controllable. Conclusions: The BPD regimen has good efficacy and tolerance in relapsed MM patients with extramedullary disease.

[Analysis of clinical diagnostic characteristics of 26131 patients with pneumoconiosis in Hunan Province]

Objective: To analyze the clinical diagnostic characteristics of pneumoconiosis patients of migrant workers in Hunan Province, and to provide scientific basis for the prevention and treatment of pneumoconiosis. Methods: In February 2022, through the Hunan Provincial Medical Treatment and Assistance Information Platform for Pneumoconiosis Migrant Workers, the cases of irresponsible subjects with pneumoconiosis that were first diagnosed clinically in Hunan Province from January 2017 to December 2021 were collected, and analyzed their gender, age, length of service, types of pneumoconiosis, stages of pneumoconiosis, and comorbidities. Results: From January 2017 to December 2021, there were a total of 26131 cases of irresponsible pneumoconiosis patients diagnosed clinically in Hunan Province, with males accounting for 99.8% (26072 cases) and an average age of (60.66±8.04) years old. Among the 26131 patients, coal workers' pneumoconiosis and silicosis were the main causes, with 16816 and 9078 cases respectively, accounting for 99.1% of the diagnosed cases. There were 8640 cases (33.1%) of stageⅠpneumoconiosis, 6601 cases (25.2%) of stage Ⅱ pneumoconiosis, and 10890 cases (41.7%) of stage Ⅲ pneumoconiosis. 2051 patients experienced complications. The average age of exposure to dust of 26131 patients was (17.81±9.69) years, and the age of exposure to dust in silicosis patients was (14.60±9.62) years. The working age of coal worker's pneumoconiosis was (19.60±9.26) years. Compared with coal workers' pneumoconiosis patients, silicosis patients had a shorter working time exposed to dust, and the difference was statistically significant (P<0.05) . Conclusion: Coal workers' pneumoconiosis and silicosis are mainly diagnosed for the first time in migrant workers' pneumoconiosis patients in Hunan Province. Pneumoconiosis patients should be diagnosed in time, which is conducive to treatment and rehabilitation.

[A retrospective study of hemophilic pseudotumor in maxillofacial region]

Objective: To provide clinical references for the diagnosis and treatment of hemophilic pseudotumor (HPT) in maxillofacial region. Methods: Fourteen cases of HPT in maxillofacial region from the Department of Stomatology, Beijing Children's Hospital from Jan 2009 to Jan 2019 were collected. Two cases were lost for follow-up and 12 patient,all boys, were finally followed up and included in the study. The patients aged from 13 months to 10 years old. The medical history, clinic manefestitions and the features of the radiology examination were recorded. The patients were treated by using replacement treatment first. If the conservative treatment was not effective, the patients then received operation combined with pereoperation replacement thearapy. The patients were followed up for 13 months to 10 years.There were 11 cases of hemophilia A, and 1 case of hemophilia B. Two cases were severe type, the others (10/12) were mild and moderate types. Only 1 case was diagnosed as hemophilia initially. Nine cases (9/12) were misdiagnosed as malignant tumors, 1 case was misdiagnosed as osteomyelitis and 1 case was misdiagnosed as hemangioma. Only 3 cases had identified history of trauma before. Results: All cases were treated with replacement therapy first, among which 10 cases were effective, 8 cases were cured by conservative therapy, 1 case had residual soft tissue fistula after conservative treatment and 1 case recurrented after conservative treatment for 8 months. Two patients with poor efficacy to the replacement treatment were performed operations and finally were cured. Conclusions: The misdiagnosis rate of HPT in maxillofacial region was high. The conservative factor replacement therapy could achieve good results in most children and could be used as the preferred treatment. If the conservative treatment was not effective, the surgical treatment was also a safe option.

[Choices of emergency treatment and surgical method for ruptured abdominal aortic aneurysms]

Objective: To investigate the emergency management process of ruptured abdominal aortic aneurysm (RAAA), and analyze the perioperative mortality factors of different surgical methods. Methods: The emergency data and hospitalization data of 91 patients with ruptured abdominal aortic aneurysm in Xiangya Hospital of Central South University from June 2010 to June 2019 were retrospectively analyzed.Twelve of the patients died preoperatively due to excessive blood loss, and the remaining 79 patients were hospitalized for open surgery (OSR) or endovascular repair (EVAR).The differences in age, time to hospital arrival, emergency preparation time, first creatinine value, emergency infusion volume, preoperative drop in blood pressure, preoperative use of vasoactive drugs and iliac artery involvement were compared between preoperative death group (n=12) and preoperative survival group (n=79), OSR group (n=50) and EVAR group (n=29), postoperative death group (n=23) and postoperative survival group (n=56). Results: Seventy-nine patients received open surgery or endovascular repair, and 23 died after operation. Age, time to hospital arrival, first creatinine value and emergency infusion volume were (77±11) years, (18±5)h, (469±150) μmol/L, (4 140±1 743) ml in the preoperative death group and (70±10) years, (12±8) h, (228±174) μmol/L, (1 358±1 211) ml in the preoperative survival group, respectively, and the differences were statistically significant (all P<0.05). There were no significant differences in preoperative data, intraoperative treatment and postoperative perioperative mortality between the open surgery group and the endovascular repair group (all P>0.05). The intraoperative blood loss, operation time and aortic occlusion rate in the endovascular repair group were 100 (50, 175) ml, (3.2±0.9) h, 13.8%, respectively, which were better than that in the open surgery group 1700 (600, 3425) ml, (5.2±1.1) h, 100%. The differences were statistically significant (all P<0.05). Age, emergency preparation time, first creatinine value, emergency infusion volume, blood pressure decline rate and vasoactive drug utilization rate in the death group were (77±8) years, (4.1±1.7) h, (456±172) μmol/L, (2 024±1 687) ml, 100%, 100%, respectively, and (68±10) years, (2.7±2.2) h, (135±26) μmol/L, (1 085±825) ml, 21.4%, 12.5% in the survival group, respectively. The differences were statistically significant (all P<0.05). Conclusions: Age, emergency preparation time, first creatinine value, emergency infusion volume, decreased blood pressure and use of vasoactive drugs are all associated with perioperative death in patients with ruptured abdominal aortic aneurysm. EVAR surgery is a better choice if conditions exist.

[Analysis of the diagnotic results and complications of pneumoconiosis patients with different insurance types]

Objective: By comparing the diagnotic results and complications of pneumoconiosis patients with work-related injury insurance and non-work-related injury insurance, to provide reference for improving the medical insurance of pneumoconiosis patients. Methods: In May 2019, the diagnotic results and complications of 3204 patients with pneumoconiosis who were hospitalized in the second department of Hunan Prevention and Treatment Institute for Occupational Diseases from January 2017 to March 2019 were retrospectively analyzed. Results: Among the 3204 patients, 896 cases (28.0%) were in stage I, 790 cases (24.6%) were in stage II, and 1518 cases (47.4%) were in stage III. 1490 cases (46.5%) of pneumoconiosis patients have complications, mainly chronic obstructive pulmonary disease (COPD) (42.3%, 1354/3204) and lung infection (23.6%, 755/3204) . 584 cases (18.2%) were covered by work-related injury insurance, and the diagnosis of pneumoconiosis patients was mainly in the stage I (61.0%, 356/584) . 2620 cases (81.8%) were covered by non-work-related injury insurance, and the diagnosis of pneumoconiosis patients was mainly in the stage III (56.0%, 1466/2620) . The complication rate of non-work-related injury insurance patients (50.1%, 1312/2620) was higher than that of work-related injury insurance patients (30.5%, 178/584) (χ(2)=73.72, P<0.01) . Conclusion: The inpatients with pneumoconiosis in Hunan Province are still mainly covered by non-work-related injury insurance, and the diagnotic period and complication rate are significantly higher than those of work-related injury insurance patients. Therefore, pneumoconiosis patients should be provided with medical security, early diagnosis and early intervention, to prevent and delay the occurrence of complications.

CXCL-10/CXCR3 in macrophages regulates tissue repair by controlling the expression of Arg1, VEGFa and TNFα

Macrophages have been reported to participate in inflammation, tissue homeostasis and tissue repair. The detailed mechanism of macrophage-mediated tissue repair is not clear. CXCL-10, secreted by monocytes, endothelial cells and fibroblasts, mediates immune response and angiogenesis by binding to CXCR3. In this study, the expression of CXCL-10 and CXCR3 in porcine lung injury induced by porcine reproductive and respiratory syndrome virus (PRRSV) infection was firstly examined. The results showed that the expression of both CXCL-10 and CXCR3 increased in the infected pig lungs. In addition, the increased expression of CXCL-10 and CXCR3 in macrophage treated by poly (I:C) was also observed, suggesting the autocrine system existed in macrophages. Furthermore, CXCL-10 treatment induced upregulation of Arg1 and VEGFa, and downregulation of TNFα in macrophage, and CXCR3 antagonist AMG487 treatment presented the contrary effects on the expression of Arg1, VEGFa, and TNFα. CXCL- 10-stimulated effects were dependent on PI3K/Akt signaling pathway. Wound-healing assay showed that CXCL-10 treatment macrophage conditioned medium promoted the healing process of endothelial cells. Our results suggested that CXCL-10/CXCR3 in macrophage may mediate tissue repair by regulating the macrophage expression of Arg1, VEGFa and TNFα. Modulation of CXCL-10/CXCR3 axis in macrophage may be a potential therapeutic strategy for tissue injury and repair.

Rapid Identification of Four New Synthetic Cannabinoids in Whole Blood

Objective To establish accurate and rapid methods to identify four new synthetic cannabinoids （JWH-203, JWH-122, 5F-APINACA and AB-CHMINACA） in blood samples. Methods The whole blood samples were extracted by acetonitrile and methanol, screened by gas chromatography-mass spectrometry （GC-MS） then confirmed by liquid chromatography-tandem mass spectrometry （LC-MS/MS） method, and multiple reaction monitoring （MRM） mode was used for quantitative analysis. Results The GC-MS method needed 21 min to complete the analysis, while the LC-MS/MS method needed 5 min. The AB-CHMINACA, JWH-203, 5F-APINACA and JWH-122 all used quasi molecular ion peak as a parent ion. The precursor-product ion combinations were m/z 357.4→312.2, m/z 340.2→125.0, m/z 384.1→135.1 and m/z 356.4→169.2. The four synthetic cannabinoids in blood samples had good linearity in the 1-250 ng/mL mass concentration range （r>0.99）. The limits of detection （LODs） were in the range of 0.1-0.5 ng/mL, the recovery rate was 85.4%-95.2%, the RSD less than 10.0%, and the matrix effect was 80.3%-92.8%. Conclusion The GC-MS and LC-MS/MS chromatographic behaviors and mass spectrometry analysis information of four synthetic cannabinoids were obtained in this study, and the possible causes of differences in chromatographic behaviors were discussed preliminarily. Therefore this study has a suggestive effect on judging the development trend of synthetic cannabinoids. This method can be used for rapid identification of four synthetic cannabinoids in blood, which can provide reference for identification of new synthetic cannabinoids when they are proliferating at present.

Role of HMGB1 in Post-traumatic Endoplasmic Reticulum Stress in Rat Lung Tissues

OBJECTIVES

To explore the role of high mobility group B1 （HMGB1） protein in the post-traumatic endoplasmic reticulum stress （ERS） in rat lung tissues.

METHODS

The rat model of acute lung injury was established by crushing the hind limbs of rats with standard weight. The first experiment was to divide rats into postural control group and crush groups （6 h, 18 h and 30 h after crushing）. The second experiment was to divide rats into postural control group, 18 h crush group, HMGB1 inhibitor sodium butyrate （SB） group and 18 h crush+SB group. The protein expression changes of HMGB1 and ERS- related proteins （GRP78, caspase-12, CHOP and IRE1α） in rat lung tissues were detected with Western blotting. Meanwhile, the pathological changes of rat lungs were observed by HE stain.

RESULTS

Compared with the postural control group, the expression levels of ERS-related proteins （GRP78, caspase-12, CHOP and IRE1α） and HMGB1 protein in rat lung tissues by crushing the hind limbs of rats were obviously increased. The protein levels reduced at 30 h after crushing but were still higher than those of postural control group and obvious pathological changes of acute lung injury were observed simultaneously in rats. Compared with the 18 h crush group, the expression levels of the ERS-related proteins and HMGB1 protein in rat lung tissues were attenuated in 18 h crush+SB group, and the pathological changes of rat lung injury began to alleviate.

CONCLUSIONS

HMGB1-ERS pathway activated by traumatic stress can lead to acute lung injury in rats.

[Prevalence and distribution of hypertension in population aged 15 years and over in Guizhou province]

Objective: To understand the prevalence and distribution of hypertension in population aged 15 years and over in Guizhou province and provide evidence for the prevention and management of hypertension. Methods: Face to face interviews using national standard questionnaire were conducted among the study subjects selected in Guizhou through multi-stage random sampling. Blood pressure measurement for them was done with Omron HEM-1300 professional portable blood pressure monitor. SPSS 19.0 software was used for statistical analysis. The ratio was compared by the χ(2) test. The influencing factors of hypertension was analyzed by multivariate logistic regression analysis. Results: A total of 13 480 participants were investigated, including 5 509 (40.8%) men and 7 971 (59.2%) women; 6 558 (48.6%) urban residents and 6 922 (51.4%) rural residents. Among the subjects surveyed, 3 232 (23.9%) were smokers, 2 412 (17.9%) were alcoholic and 4 859 (36.0%) were obese or overweight. A total of 3 937 (29.2%) hypertension patients were found. The prevalence of hypertension was 29.2%. The standardized prevalence of hypertension were 18.97% (compared with national population composition) and 21.16% (compared with Guizhou province population composition), respectively. The hypertension prevalence in men and women were 29.8% and 28.8%, respectively. The hypertension prevalence in rural population (35.8%) was higher than that in urban population (22.2%). The difference was statistically significant (P<0.001). The hypertension prevalence in people aged 65 years and over was 56.2%. The prevalence of hypertension were 34.3% and 27.6% in smokers and non-smokers, 39.2% and 27.0% in alcoholic and non-alcoholic and 40.7% and 22.7% in obese or overweight group and normal or less weight group, respectively. There were significant statistical differences in prevalence of hypertension among the population in urban area and rural area, with different age, education levels, smoking status, drinking status and BMI (P<0.001). Conclusions: The prevalence of hypertension in Guizhou was at a high level. The hypertension prevalence in rural area was higher than that in urban area. Hypertension prevalence increased significantly with age. The prevalence of hypertension was negatively associated with the education level of the people. Older age, living in rural area, smoking, drinking, obesity were the risk factors for hypertension.

[Analysis of individualized primary prophylactic treatment of 19 cases of children with severe hemophilia A]

Objective: To study the current situation of primary prophylaxis in severe hemophilia A children and to explore rational regimen in order to provide evidence for the development of primary prophylaxis in China. Method: A retrospective clinical data collection and analysis was conducted for 19 severe hemophilia A children who received primary prophylaxis in Beijing Children's Hospital outpatient clinic between February 2011 and September 2015 and evaluated the regimen and efficacy. Result: (1) Primary prophylaxis regimen: the median beginning age 1.8 (range 0.5-2.9) years, the median FⅧ preparation using dosage 16.7 (8.0-23.5) U/(kg·time), the median using frequency was 1.0 (1.0-3.0) time/week. Eight cases among the patients received escalation of treatment intensity because of the poor bleeding control. (2) Efficacy: the median annual bleeding rate (ABR) was 1.9 (0-6.0) times/year, the median annual joint bleeding rate (AJBR) was 0 (0-3.3) times/year, without life threatening bleeding. All of them kept in 4th scale of Beijing Children Hospital daily activity level. The median annual factor consumption was 1 844 (840-5 040) U/kg. Conclusion: Low-dose primary prophylaxis regimen which were in low-dose /low frequencies and adjusted by bleeding frequency could decrease bleeding and joint bleeding frequency significantly, maintained the normal daily activity capacity and saved the factor consumption compared to standard regimen in severe hemophilia A children.

[Relationship among airway infection, lung function damage and the tumor recurrence in patients with laryngeal cancer]

Objective:To investigate the relationship among airway infection, lung function damage and the tumor recurrence in patients with laryngeal cancer.Method:Eighty-six patients with laryngeal cancer were retrospectively analyzed.Infection rate were compared between different surgical airway and operation time, the lung function damage and the tumor recurrence were analysed.Result:Total laryngectomy group joint cervix lymph node dissection showed higher airway infection rate than laryngectomy［32.5%（13/40）vs 4.3%（2/46）,P <0.05］. Significant differences were observed among operation time＜4 h, 4-6 h,＞6 h airway infection rate is statistically ［2.5%(1/40),19.4%(6/31),53.3%(8/15), P <0.05］; Infection rate was positively correlated with the trachea and the operation time(r=0.41P <0.01). Significant rise in FEV1% and reduce in V25 were observed after operation(P <0.05). No statistical difference were observed in patients with airway infected or uninfected with tumor recurrence and uninfected group is ［13.3% (2/15)vs 9.9%(7/71)，P > 0.05］.Conclusion:Throat cut method may lead to airway infection and impairment of the lung function, but airway infection has no obvious effect in tumor recurrence.

Colossal Magnetoresistance in a Mott Insulator via Magnetic Field-Driven Insulator-Metal Transition

We present a new type of colossal magnetoresistance (CMR) arising from an anomalous collapse of the Mott insulating state via a modest magnetic field in a bilayer ruthenate, Ti-doped Ca_{3}Ru_{2}O_{7}. Such an insulator-metal transition is accompanied by changes in both lattice and magnetic structures. Our findings have important implications because a magnetic field usually stabilizes the insulating ground state in a Mott-Hubbard system, thus calling for a deeper theoretical study to reexamine the magnetic field tuning of Mott systems with magnetic and electronic instabilities and spin-lattice-charge coupling. This study further provides a model approach to search for CMR systems other than manganites, such as Mott insulators in the vicinity of the boundary between competing phases.

MicroRNA-217, down-regulated in clear cell renal cell carcinoma and associated with lower survival, suppresses cell proliferation and migration

Aberrantly expressed microRNAs (miRNAs) are frequently correlated with a variety of human cancers, including clear cell renal cell carcinoma (ccRCC). In this study, we determined the expression patterns of miR-217 in ccRCC, and tested its effect on cancer cell proliferation and migration. The expression levels of miR-217 were determined in 54 ccRCC samples using Real-Time qPCR. 786-O and ACHN cells were transfected with miR-217 mimics or miRNA mimics control. Cell proliferation and migration were evaluated by MTT assay and scratch-wound assay, respectively. We found that miR-217 was down-regulated in ccRCC compared to paired normal tissue. Lower miR-217 expression levels were associated with higher tumor grade and stage. All patients with high miR-217 expression survived 5 years, while with low miR-217 expression, only 40% survived. Cell proliferation inhibition and decreased motility were observed in cells transfected with the miR-217 mimics. In conclusion, miR-217 plays a tumor suppressor role in ccRCC.

Identification of the isoamylase 3 gene in common wheat and its expression profile during the grain-filling period

In higher plants, isoamylase-type starch debranching enzyme catalyzes the α-1,6-glucosidic linkages of glycogen and phytoglycogen. We cloned an isoamylase-type starch debranching enzyme ISA3 cDNA sequence (2883 bp), designated as TaISA3, from common wheat (Triticum aestivum), using the rapid amplification of cDNA ends method. The open reading frame of TaISA3 was found to have 2331 bp, and its deduced amino acid sequence was found to share high similarity with those of other gramineous plant ISA3 proteins. It contains a putative transit peptide (68 amino acids), N-terminus domain (107 amino acids), and a catalytic domain (173 amino acids). We extracted the expressed TaISA3 protein from Escherichia coli (BL21), and measured starch isoamylase activity. During the wheat grain-filling period, transcripts of the TaISA3 gene reached a maximum level at the early developmental stage, then declined, and increased again near the final maturation stage of the grain. We confirm that the ISA3 gene is present in common wheat; it appears to play a role in starch synthesis during early and late stages of the grain-filling period.

High-quality photonic crystal heterostructures fabricated by a modified self-assembly method

High-quality three-dimensional photonic crystal (PC) heterostructures were fabricated using the modified self-assembly method, and their structural and optical properties were analyzed. Results suggest that the optical quality of heterostructures formed by depositing bigger particles on small ones is superior to that of heterostructures formed by stacking smaller particles on big ones, due to the rough interface effects in the latter structure. The roughness of the interface in the latter structure can be largely improved by introducing a thin two-dimensional planar defect layer into the PCs, and significant progress in the quality of the heterostructures is achieved. The important role of the thin planar defect layer in the quality of the heterostructures was also verified by numerical simulations.

Source seasonality of polycyclic aromatic hydrocarbons (PAHs) in a subtropical city, Guangzhou, South China

Mega-cities are large sources of air pollution on a regional base. Differences in energy structures, geographical settings and regional climate features lead to a large variety of air pollution sources from place to place. To understand the seasonality of air pollution sources is critical to precise emission inventories and a sound protection of human health. Based on a year-round dataset, the sources of PAHs in the air of Guangzhou were drawn by principal factor analysis (PCA) in combination with diagnostic ratios, and the seasonality of these sources were analyzed by PCA/MLR (multiple linear regressions) and discussed. The average total gaseous and particulate PAHs concentrations were 313 and 23.7 ng m(-3), respectively, with a higher concentration of vapor PAHs in summer and particulate PAHs in winter. In addition to vehicle exhaust, which contributed 69% of the particulate PAHs, coal combustion was still an important source and contributed 31% of the particulate PAHs. Relatively constant contribution from coal combustion was found through the year, implying that coal combustion in power plants was not a seasonally dependent source. Evaporation from contaminated ground may be an important source of light PAHs in summer, providing an average contribution of 68% to the total PAHs in this study. By comparing the PAH concentrations and meteorological parameters, we found that higher concentrations of particulate PAHs in winter resulted from enhanced vehicle exhaust under low temperature and accumulation of pollutants under decreased boundary layer, slower wind speed, and long-term dryness conditions. It is suggested that the typical subtropical monsoon climate in South China, cool and dry in winter, hot and humid in summer, may play a key role in controlling the source seasonality (by enhancing vehicle exhaust in winter, ground evaporation in summer), and hence the ambient concentrations of PAHs in the air.

Sedimentary record of polycyclic aromatic hydrocarbons in a sediment core from the Pearl River Estuary, South China

Owing to the hydrodynamic and sedimentation conditions, the western shoal of the Pearl River Estuary (PRE) is known to be an important sink of terrestrial substances including particle-associated pollutants from the Pearl River Delta (PRD) region. In this study, we report the sedimentary record of polycyclic aromatic hydrocarbons (PAHs) during the 20(th) century in a sediment core from the western shoal of the PRE. The summation PAH concentration ranged from 59 ng g(-1) to 330 ng g(-1) in the core with two distinct peaks. An initial increase of summation PAH concentration was found around the 1860s. The amounts of PAHs remained relatively constant for roughly 100 years, followed by the first peak in the 1950s. Then, there was a decrease in PAH concentration and flux in the 1960s and 1970s. A sharp increase of PAH concentration was observed in the early 1980s with a maximum concentration in the 1990s. The PAH diagnostic ratios indicated that the PAHs in the sediment core were mainly of pyrolytic origin, and that atmospheric deposition and land runoff may serve as the important pathways for PAHs input to the sediment. The Gross Domestic Product (GDP) was used as an index of socioeconomic development in the PRD region, which was correlated positively with the changes of PAH concentration and flux in the sediment core. The rapid increase in vehicle numbers and energy consumption in the region in the last two decades may have contributed to the rapid PAH increase since the early 1980s. The results clearly elucidated the impact of regional economic development on the estuarine environment.

Effect of p-glycoprotein inhibitor combinations on drug efflux from rat brain microvessel endothelial cells

In an effort to develop a clinically useful approach to inhibit the drug efflux across the blood brain barrier (BBB) mediated by P-glycoprotein (P-gp), the combined inhibitory effect of four P-gp inhibitors: cyclosporin A (CsA), verapamil (Ver), tetrandrine (Tet) and doxorubicin (Dox), was evaluated by determining the intracellular concentration of rhodamine 123 in in vitro cultured rat brain microvessel endothelial cells (BMEC). The results showed that CsA combined with Ver or Tet synergistically inhibited P-gp mediated efflux of Rh123 from rat BMEC, suggesting that the combined application of P-gp inhibitors would possibly be a useful approach to increase drug concentration in brain tissues, enhance the therapeutic effect and reduce the toxicity of drugs.

Milk trait heritability and correlation with heterozygosity in yak

382 yak cows were examined for milk yield, fat, protein and lactose contents. Six polymorphic loci, alphas1-CN, kappa-CN, beta-CN, beta-Lg, alpha-La and MUC-1, were scored by PAGE electrophoresis for each individual. The values of milk yield, fat, protein and lactose content were 247.13 kg, 5.81%, 5.18% and 4.93%, respectively. Based on the 6 polymorphism loci, the average heterozygosity of the yak population was 0.1794. Calculated by the marker-based method, heritability estimates for milk yield, fat, protein and lactose contents were 0.353 +/- 0.093, 0.316 +/- 0.101, 0.415 +/- 0.098 and 0.481 +/- 0.035, respectively. The relatively high or medium heritability of these traits indicate that it is feasible to rely directly on them in breeding for the improvement in a relatively short period. The significant linear regression between heterozygosity and fat percentage with a positive slope (R = 0.0420) indicated that inbreeding affected milk fat content in this population.

Analysis of glucose and lactate in dialysate from hypothalamus of rats after exhausting swimming using microdialysis

A microbore flow injection analysis-immobilized enzyme reactor-electrochemical detection (FIA-IMER-ECD) system for glucose and lactate detection was built up. The assays were precise, sensitive and practicable for determination of glucose and lactate levels in hypothalamic dialysate. The method had been used to detect the dynamic changes of glucose and lactate levels during rat exhausting swimming and recovery. The data showed that after exhausting swimming, the concentration of glucose in hypothalamic dialysate that reflected the concentration in the hypothalamic extracellular fluid decreased. The level fell to its nadir at day 1 after the exercise and then went back to the basal level at day 3 after the swimming. However, lactate levels increased to a maximum at day 3 and went back to the basal level at day 5 after the swimming.

Erianin induces apoptosis in human leukemia HL-60 cells

AIM

To investigate the effect of erianin on human HL-60 cell line and explore its mechanism of apoptosis in vitro.

METHODS

Inhibition of proliferation was measured with colorimetric MTT assay. The morphologic changes were observed by fluorescence and electron microscopes. DNA fragmentation was visualized by agarose gel electrophoresis, and the DNA degradation was determined by flow cytometry. Immunohistochemical analysis was used to identify the expression of bcl-2 and bax genes.

RESULTS

The growth of human HL-60 cells was significantly inhibited by erianin 20-81.9 nmol/L during 72 h treatment (P < 0.01). The IC50 value was 38 nmol/L after a 24-h exposure to erianin, while that of vincristine, the positive control, was 101 nmol/L. The typical morphologic changes were observed and the nuclear DNA fragmentation exhibited "ladder" pattern. The cell cycle of HL-60 cells was arrested in G2/M phase, and expression of bcl-2 gene was decreased while that of bax was increased.

CONCLUSION

Erianin showed potent inhibitory activity on the proliferation of HL-60 cells. The inhibition might be relative to the apoptosis induced by erianin and the altered expression of bcl-2 and bax genes in HL-60 cells.

Inhibition of serum deprivation-induced PC12 cell apoptosis by tanshinone II A

AIM

To study the effect of tanshinone II A (Tan II A) on PC12 cell apoptosis induced by serum deprivation.

METHODS

PC12 cell survival was measured by MTT assay. The DNA content and percentage of apoptosis were monitored by flow cytometry and DNA fragmentation was analyzed by agarose gel electrophoresis.

RESULTS

Serum-free (12 h) medium induced apoptosis in PC12 cells. When the cells had been treated with Tan II A (0.1 and 1 micromol . L-1) for 12 h, the percentage of PC12 cell apoptosis was greatly decreased to 25.71 % and 4.89 % from 96.07 % in serum deprivation alone group, and DNA fragmentation was prevented. Tan II A (0.01 - 10 micromol . L-1) attenuated the cytotoxic effect of sodium cyanide (20 mmol . L-1), glutamate (0.5 mmol . L-1), and sodium nitroprusside (0.5 mmol . L-1).

CONCLUSION

Tan II A prevented PC12 cells from apoptosis induced by serum-free medium.

[The relationship between the change of mitochondria and the fertility in CMS line of sorghum after heat shock]

The mitochondria of anther in pollen mother cell stage of cytoplasmic male sterility (CMS) line 3197A in sorghum were extracted after heat shock. The number of the mitochondria was measured by flow cytometer and some isoenzymes were analyzed by PAGE combined with stain for enzyme activity. The result of mitochondria quantity measurement shows that the number of the mitochondria in CMS line 3197A increased greatly up to 4.5 folds after heat shock. The analysis of isoenzymes also demonstrates that the type of isoenzyme in CMS line is in consistent with maintainer line. The study denoted the change of the quantity of mitochondria after heat shock and the relationship between this change and the fertility in sorghum.

[Analysis of isozyme and RAPD for the germplasm lines from G. hirsutum x G. bickii]

To study the effectiveness of Gossypium interspecific hybrid breeding on molecular level, the six germplasm lines from interspecific hybrids between G. hirsutum and G. bickii were analysed by the techniques of RAPD and isozyme electrophoresis. The main results were summarized as follows: (1) The basic zymograms of peroxidase isozyme of the six germplasm lines were similar to their G. hirsutum parent, but two out of the germplasm lines showed one specific band of the wild parent of G. bickii (pI 4.85); (2) The RAPD fingerprint showed distinct difference of genomic DNA among the germplasm lines; (3) The four specific DNA fragments of G. bickii were observed in RAPD patters of four out of the six germplasm lines.

[A study of genetic character of cultivar Shiyuan 321 from G. barbadense x G. thurberi x G. hirsutum using isozyme and RAPD techniques]

To study the genetic character of trispecific hybrid cultivar Shiyuan 321, we analyzed this cultivar and its parents by isozyme and RAPD techniques. The main results are as follows: (1) Esterase isozyme analysis showed that there was one specific band among cultivar Suiyuan 321 and its parents, G. thurberi and G. barbadense; (2) Six specific DNA fragments amplified by 4 primers were found among cultivar Shiyuan 321 and its parents G. barbadense, G. thurberi; (3) By comparing RAPD differences among Shiyuan 321 and its parents, it is indicated that the genetic heterogeneity of cultivar Shiyuan 321 is very high at its genomic DNA level. The above results proved that Shiyuan 321 is a trispecific cultivar from G. barbadense x G. thurberi x G. hirsutum as well as a new germplasm.

[Preparation of restricted-access media--alkyl-diol silica (ADS) by an improved method]

Alkyl-diol silica (ADS) is a kind of restricted-access media, which can be used for direct injection and analysis of complex biological samples containing bio-macromolecules. A new economical procedure has been developed to prepare ADS packing. At first gamma-glycidoxypropyl group was coupled onto the surface of microporous silica gel (Develosil 60-5 mu) to form epoxy-silica. Prepared epoxy-silica can react with stearic acid in organic solvent to prepare C18 ester-bonded reversed-phase packing. The packing was packed into a column and then the solution of pancreatic lipase was pumped into the column to create enzymoloysis reaction. The stearyl groups on the surface of packing can be removed by the enzymolysis to form a hydrophilic surface. At the same time, inner surface of micropore remains hydrophobic nature due to size exclusion effect of micropore to enzyme molecules. Chromatographic evaluations were carried out and the typical ADS behavior was confirmed.

[Study on induced mutation of sorghum seeds on recoverable satellites]

OBJECTIVE

To observe and investigate the variation and heredity of the offspring of dry seeds of sorghum carried by satellite hence to select excellent mutants and to cultivate directivity new varieties for production application.

METHOD

Dry seeds of Tanghui 28, a sorghum restorer line, were carried to the space on board a recoverable satellite for 15 d. After recovery the seeds were planted in the field to study the growth dynamics and change of agricultural characters.

RESULT

Variations of characters such as dwarfing of stalk, significant increase grain weight per spike etc were observed in SP1 generation. Wide separation occurred in SP2 generation. Regardless that only non-significant separation of disease resistance and a very little variation of glum color were observed, the other characters varied significantly, and a super large panicle type varied line was obtained. Its spike length was 4 cm longer, and grain weight per spike was 58.5 g more than the control.

CONCLUSION

It may be considered that the variation of sorghum seeds induced by the space conditions was heritable to the offsprings. Therefore, exposure to the space environment could be used as a method for mutagenic seeds breeding.

P glycoprotein regulated transport of glutamate at blood brain barrier

AIM

To study whether efflux of glutamate (Glu) at blood brain barrier (BBB) was regulated by P-glycoprotein (P-gp).

METHODS

1) After intracerebral microinjection [3H]Glu 5 min, recoveries were determined in injected cerebrums in presence of multidrug-resistant(MDR) reversing agents verapamil (Ver), vincristine(VCR), an d cyclosporin A(CsA); 2) apparent transfer constants (Kin) of [3H]Glu from plasma to brain were determined after the in situ rat brain perfusion 2 min us ing solution containing MDR-reversing agents; 3) uptake amount of [3H]Glu by prima ry cultured bovine brain capillary endothelial cells(BCEC) was analyzed; and 4) In presence of MDR-reversing agents and antibody of P-gp, C(219), uptake amount of [3H]Glu by luminal membrane vesicles derived from BCEC was also determined.

RESULTS

In control rats, remaining percentage of [3H]Glu in inject ed cerebrums was 25 %+/-16 % at 5 min after intracerebral injection. After pre-treating with CsA 10, 100 micromol/L, VCR 20 micromol/L and Ver 100 micromol/L, the remaining percentages of [3H]Glu were increased to about 2.2, 2.5, 2.3, a nd 2.7 folds of control, respectively. In the in situ rat brain per fusion experiment, VCR and CsA in perfusion medium concentration-dependently increased [3H]Glu BBB permeability to brain. Co-administration o f CsA 40 micromol/L mad e BBB permeability of [3H]Glu in cerebral cortex, hippocampus and striatum increase to about 9, 3, 7, and 4.6 folds of control, respectively. Steady-state uptake of [3H]Glu by BCEC was also increased up to 2.5 folds in presence of 100 micromol/L CsA. MDR-reversing agents and antibody of P-gp, C219, level-dependently inhibited the uptake of [3H]Glu by luminal membrane vesicles of BCEC. And this process is ATP-dependent.

CONCLUSION

Efflux of Glu at BBB may be regulated by P-gp.

Fundamental study of the behavior of chlorine during the combustion of single RDF

A fundamental study of the combustion characteristics and the de-HCl behavior of a single refuse-derived fuel (RDF) pellet was carried out to explain the de-HCl phenomena of RDF during fluidized bed combustion and to provide data for the development of high efficiency power generation technology using RDF. In this research, combustion and pyrolysis experiments were carried out in an electrical furnace using a series of model and actual RDF samples. The de-HCl capability of Ca(OH)2 in RDF was evaluated by measuring the emission fraction of HCl in the flue gas and the capture fraction of Cl in the residue. It was found that the capture fraction of Cl components in the residue increased from 0 to nearly 70% when the molar ratio of Ca/Cl was changed from 0 to around 13. Apparently, the capture fraction also decreased with increasing oxygen concentration in the feed gas. The devolatilization process of RDF was confirmed to be a very important part of de-HCl process. The effect of temperature profile of the RDF pellet on the de-HCl process, as it varies with the heating rate of RDF and the oxygen concentration in the vicinity of the sample, is discussed.

Tetrandrine inhibits inward rectifying potassium current in cultured bovine aortic endothelial cells

AIM

To study the effect of tetrandrine (Tet) on inward rectifying potassium current in cultured bovine aortic endothelial cells.

METHODS

Inward rectifying potassium current (IRK) was observed by the whole cell patch-clamp technique.

RESULTS

IRK was inhibited by Tet in a concentration-dependent manner and recovered to normal after wash with drug-free external solution. IRK was reduced from (582 +/- 48) pA to (221 +/- 40) pA at a holding potential of -70 mV by Tet 30 mumol/L. IC50 was 2.8 mumol/L.

CONCLUSION

Tet inhibited inward rectifying potassium current in cultured bovine aortic endothelial cells.

[Introduction of rabbit defensin NP-1 gene into poplar (P. tomentosa) by Agrobacterium-mediated transformation]

Rabbit defensin NP-1 possesses a broad resistant spectrum to pathogens. In this work, we have transferred the NP-1 gene into poplar plants by Agrobacterium-mediated transformation. PCR amplification and Southern analysis showed that rabbit defensin NP-1 gene was integrated into the poplar genome. The transformation efficiency is about 15.6%. Antimicrobial activity test showed that the extract of transgenic plants inhibited the growth of the tested microbes.

[Molecular tagging of a new recessive gene for late heading in a rice cultivar 8987]

8987 is a late flowering (lf) indica cultivar. In this study, genetic analysis for lf was carried out in the crosses between 8987 and four varieties with different heading time. Inheritance of lf in F1 plants and F2 populations clearly revealed that the lf of 8987 is controlled by one recessive gene. Bulked-segregant method and cosegregation analysis in F2 population were used to screen molecular markers, which were linked with lf gene. The results showed that the lf gene was mapped between the two RFLP marker C213 and RG404 on chromosome 7. The tagged gene will be utilized in molecular marker assisted selection in the future rice breeding program for new varieties.

[Integration via Tn10 and expression of Bti cryIVA gene in the chromosome DNA of flourescent Pseudomonas bacterial strains]

cryIVA gene of the Bacillus thuringiensis subsp. israelensis was subcloned into the Tn10 of a suicide transposon plasmid vector and a transposon plasmid pLF97A carrying cryIVA was constructed. By electroporation and transposition, cryIVA gene integrated into chromosome DNA of F.P.DE2. Thus the genetic engineered bacterial strain, F.P.DE202, was constructed. Southern blotting revealed that this integration was happened in different loci of the chromosome. Western blotting demonstrated that cryIVA was expressed in the engineered strain, and that the expressed product possesed the pesticidal ability against the third-instar larva of Bradysia odoriphaga.

Intracarotid infusion of hypertonic mannitol changes permeability of blood-brain barrier to methotrexate in rats

AIM

To study whether infusion of hypertonic mannitol through internal carotid artery could enhance methotrexate (MTX) concentration in rat cortex and to study the time-course of this process.

METHODS

Hypertonic mannitol was infused into the rat left internal carotid artery, ten minutes later, MTX was injected from the left femoral vein (i.v.) or left common carotid artery (ia), and the concentration of MTX was assayed 1 h later. Rats were given MTX at different time interval after infusion of mannitol, and the concentration of MTX was assayed 1 h after drug administration. At the same time, the rat cortex's density was analyzed.

RESULTS

After mannitol infusion, MTX's concentration in rat cortex increased 2.54 times (i.v.) and 3.41 times (ia) as compared to control, respectively. After 10 min, such effect reached its peak, and almost disappeared after 6 h. There was no significant change in rat cortex's density.

CONCLUSION

Mannitol can make blood-brain barrier (BBB) reversibly permeable, and increase MTX concentration in brain without any obvious injury to the brain.

Progressive specific immune attrition after primary, secondary and tertiary immunizations with bacteriophage phi X174 in asymptomatic HIV-1 infected patients

BACKGROUND

Antibody responses to immunization are often compromised in patients infected by HIV-1, and the use of childhood immunization in affected children is controversial. We investigated whether multiple immunizations with a T cell-dependent neoantigen, bacteriophage phiX174, induce selective immune attrition and post-vaccination viremia.

METHODS

Seventeen asymptomatic, antiretroviral therapy-naïve HIV-1-infected patients with a CD4 cell count of 450 cells/microl or greater were immunized in 1990/1991 with three intravenous doses of bacteriophage phiX174. Group 1 received zidovudine (ZDV) during the primary and secondary immunization. Group 2 received ZDV exclusively during the tertiary immunization. Bacteriophage-specific antibodies of the IgM and IgG class, lymphocyte phenotypes (CD4+, CD8+, CD4+DR+, CD8+DR+, CD4+CD45RO+ and CD4+45RA+, CD4+CD45RO+DR+) and HIV-1 plasma viremia were measured sequentially.

RESULTS

In both patient groups the primary, secondary and tertiary antibody responses, as expressed by geometric mean antibody titres and IgM to IgG switch, were impaired. Booster immunizations resulted in a progressive attrition of specific antibody responses to bacteriophage. Antibodies to tetanus toxoid remained stable. The HIV-1 viral loads, which were evaluated in archived specimens from eight patients, increased after immunization but returned to baseline approximately 4 weeks later. The humoral immune attrition and increases in plasma viremia were blunted by concomitant short courses of ZDV.

DISCUSSION

Multiple boosters of immunizations in asymptomatic treatment-naive HIV-1-infected patients may result in a specific immune attrition and vaccine-induced viremia. Short-term monotherapy with ZDV may have blunted these adverse effects. Hyperimmunization of HIV-1-infected patients may be detrimental unless accompanied by antiretroviral therapy.

Tumor necrosis factor alpha enhances the cytotoxicity induced by nitric oxide in cultured cerebral endothelial cells

It has been shown that independent sources of nitric oxide (NO) and the inflammatory cytokine tumor necrosis factor alpha (TNFalpha) contribute to the breakdown of the blood-brain barrier (BBB) in the pathogenesis of a number of brain disorders. However, the interaction of NO and TNFalpha has not been elucidated. The present study was designed to determine whether the toxicity induced by NO is altered by TNFalpha in brain capillary endothelial cells (BCECs), and if so, whether it is related to the generation of superoxide. TNFalpha (50-400 U/ml) did not produce toxicity until at a concentration of 800 U/ml. This toxic effect was completely blocked by copper-zinc superoxide dismutase (SOD)/catalase or N(omega)-nitro-L-arginine methyl ester (L-NAME) or oxyhemoglobin (HbO2). Sodium nitroprusside (SNP) reduced with 0.4 mM ascorbate (SNP/Vc) significantly increased Lactate dehydrogenase (LDH) efflux in a concentration-dependent manner. This cytotoxicity of SNP/Vc was also completely inhibited by SOD/catalase or HbO2. When SNP/Vc used in combination with 400 U/ml TNFalpha, a more remarkable LDH efflux was induced than SNP/Vc alone, even as little as 0.01 mM SNP/Vc was toxic, although a dose of 400 U/ml TNFalpha alone had no effect on LDH efflux. In addition, either 0.4 mM SNP/Vc and 800 U/ml TNFalpha alone or 0.4 mM SNP/Vc and 400 U/ml TNFalpha in combination significantly increased malondialdehyde (MDA) content, but nitric oxide synthase (NOS) activity was inhibited only by SNP/Vc and TNF in combination. These results suggest that TNFalpha enhances the toxicity of NO in BCECs and that at least part of this enhancement involves the generation of superoxide.

[A novel method for preparation of C18 ester-bond RP-HPLC packing]

RP-HPLC packings have found widespread application in the fields of biology, chemistry and pharmaceutical industry, etc. C18-bonded phase is one of the most important packing. In order to avoid using toxic and unstable chloro-containing silane as derivatization reagent, a new practical and economic procedure had been developed to prepare RP packing. Octadecyl group was bound onto YQG80, 5 microns silica (Tsingdao Oceanic Chemical Factory, particle size d.p. 5 microns) with gamma-glycidoxypropyltrimethoxysilane as coupling agent. Elemental analysis and chromatographic evaluation confirmed the feasibility of the procedure and RP behavior of the packing. After eluting with 500 column volume of mobile phase at different pH (2, 5 and 8), the column still showed good performance (> 64,000 theoretical plates/m) and stability.

Immunologic responses of HIV-1-infected study subjects to immunization with a mixture of peptide protein derivative-V3 loop peptide conjugates

V3 loop peptide sequences from several HIV-1 strains were covalently linked to purified protein derivative (PPD) of Mycobacterium tuberculosis. A mixture of PPD conjugates of V3 loop peptides from six different strains of HIV-1 induced a stronger antibody response than a single V3 peptide-conjugate administered to guinea pigs and humans. Sera from animals immunized with a PPD-six peptide-PPD conjugate neutralized multiple primary-isolate strains of HIV-1. Potent immune responses were noted only when animals were primed with bacillus Calmette-Guerin (BCG), PPD was covalently bound to the peptides, and PPD was used as the carrier protein. Based on these animal studies, an immunogen consisting of PPD-conjugated V3 loop peptides from five HIV-1 strains was tested in 7 HIV-1 seropositive PPD skin test positive study subjects. Vaccinees exhibited over time a uniform increase in neutralizing antibodies for both laboratory adapted and primary isolates of HIV-1, including strains from multiple clades. In 3 patients with baseline viral loads between 8000 and 12,000 RNA copies/ml, the viral load declined in 2 patients to <400 copies/ml and in 1 patient to 1200 copies/ml without concurrent administration of highly active antiretroviral therapy (HAART).

L-pyroglutamic acid protects rat cortical neurons against sodium glutamate-induced injury

AIM

To evaluate the effects of L-pyroglutamic acid (L-PGA, L-5-oxo-2-pyrrolidinecaroxylic acid) on sodium glutamate-induced neurotoxicity in rat cortical neurons.

METHODS

In primary cortical cultures from 16-d-old fetal rat, neuronal viability and contents of nitrite in the bathing medium after transient exposure to sodium glutamate (Glu) were measured; with Fura 2-AM as an intracellular calcium indicator, AR-CM-MIC cation measurement system was used to examine cytosolic free calcium ([Ca2+]i).

RESULTS

L-PGA 10-80 mumol.L-1, inhibited Glu (500 mumol.L-1)-induced neuronal loss in a concentration-dependent manner with IC50 value of (41 +/- 9) mumol.L-1 (95% confidence limits: 30.3-54.7 mumol.L-1). L-PGA also attenuated Glu-induced NO release. L-PGA 1, 3, 10, 30, and 100 mumol.L-1 depressed Glu-caused [Ca2+]i elevation by 20.5%, 34.4%, 47.7%, 70.6%, and 80.4%, respectively.

CONCLUSION

L-PGA protects cortical neurons against Glu-induced neurotoxity which may be related to inhibition of NO formation or suppression of the rise in [Ca2+]i.

Efflux transport of [3H]GABA across blood-brain barrier after cerebral ischemia-reperfusion in rats

AIM

To study whether the efflux transport of [3H]GABA across the blood-brain barrier (BBB) would be enhanced after cerebral ischemia-reperfusion.

METHODS

Brain efflux index (BEI) of [3H]GABA was determined in ischemic-reperfused rats after [3H]GABA or [3H]GABA combined with unlabeled GABA or probenecid (Pro) was microinjected into the parietal cortex area 2 (Par 2), and brain uptake of Evans blue (EB) was assessed after i.v. EB.

RESULTS

BEI in rats subjected to 10-min ischemia and 30-min, 2-h, 6-h, or 24-h reperfusion were 67%, 83%, 92%, and 87%, respectively, which were higher than that in control (58%). The brain uptake of EB was also considerably increased. Unlabeled GABA or Pro obviously decreased BEI in normal or 6-h reperfused rats, but GABA had no obvious effect on that in 5-min reperfused rats.

CONCLUSION

The efflux transport of [3H]GABA was markedly enhanced after cerebral ischemia-reperfusion in rats.

l-S.R-daurisoline protects cultured hippocampal neurons against glutamate neurotoxicity by reducing nitric oxide production

AIM

To explore mechanisms of l-S.R-daurisoline (DS)-mediated protection of cultured hippocampal neurons from sodium glutamate (Glu) cytotoxicity.

METHODS

Cultured neurons obtained from rat hippocampus were used to examine the protective effect of DS against Glu neurotoxicity. Cell viability was estimated using trypan blue dye exclusion method and [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay. Release of nitric oxide (NO) from the hippocampus was assayed using rat thoracic aorta in vitro.

RESULTS

DS 0.01-10 mumol.L-1 concentration-dependently inhibited Glu cytotoxicity and increased cell viability with 50% prevention of cell death 2.8 mumol.L-1 (95% confidence limit 1.2-5.9 mumol.L-1). This protection was mostly attenuated by L-arginine (Arg) 1 mmol.L-1. DS 0.01-10 mumol.L-1 did not prevent sodium nitropusside (SNP) 500 mumol.L-1-induced cytotoxicity. DS 10 mumol.L-1 blocked Glu-elicited relaxation of the endothelium-denued rat aortic rings contracted by norepinephrine (NE) 10 mumol.L-1 in the presence of hippocampal tissue, but did not affect that induced by SNP. This indicated that DS inhibited Glu-triggered NO generation but did not prevent the effects of NO.

CONCLUSION

DS prevented neurons from Glu neurotoxicity by inhibiting Glu-triggered NO generation.

[Two-site absorption model fits to pharmacokinetic data of gemfibrozil in man]

The plasma concentration-time data of gemfibrozil in 8 male subjects were determined after an oral dose of 600 mg. Two-peak concentrations in plasma were observed. A kind of one-compartment model with two-sites of drug absorption was proposed and used to fit these data. A good agreement between observed and predicted data was found in all subjects with correlation indexes (gamma 2) > 0.99. The corresponding pharmacokinetic parameters were estimated as follows: Tmax1, 1.10 +/- 0.46 h; Tmax2, 2.60 +/- 0.73 h; Cmax1, 13.62 +/- 4.30 micrograms.ml-1; Cmax2, 17.22 +/- 3.83 micrograms.ml-1; T1, 0.06 +/- 0.06 h; T2, 1.42 +/- 0.57 h and T3, 1.79 +/- 0.60 h.

[Pharmacokinetic and electocardiographic study of oral verapamil sustained-release tablet in 10 Chinese volunteers]

Both verapamil pharmacokinetics and electrocardio graphic changes in 10 Chinese volunteers were studied after po 240 mg of verapamil sustained release tablet. A one-compartment model with zero-order absorption gave a better fitting to concentration--time data with values of r2 > 0.96. The main pharmacokinetic parameters obtained were: Tmax, 5.9 +/- 1.6 h; Cmax, 118.9 +/- 37.2 micrograms.L-1; T1, 5.4 +/- 1.5 h; k0, 30.5 +/- 17.5 micrograms.L-1.h-1; T1/2, 10.8 +/- 4.9 h; MRT, 15.4 +/- 3.2 h and AUC. 1.96 +/- 0.82 mg.h.L-1. There were significant prolongations of PR intervals after dose. Relationships between PR interval changes and plasma concentrations of verapamil were better fitted to sigmoidal model, with r2 > 0.98. The corresponding pharmacodynamic parameters were estimated. EC50, 64.6 +/- 16.9 micrograms.L-1, Emax, 54 +/- 11 ms and s, 1.68 +/- 0.66.

Sodium and chloride-dependent high and low-affinity uptakes of GABA by brain capillary endothelial cells

The mechanisms of carrier-mediated transport of gamma-aminobutyric acid (GABA) at the blood-brain barrier (BBB) were examined by investigating [3H]GABA uptake by isolated bovine brain capillaries, monolayers of primary cultured brain capillary endothelial cells (BCECs) attached to plates or suspended BCECs. The uptake of [3H]GABA was concentration-dependent and saturable. Nonlinear regression analysis of the original data indicated the existence of two distinct high and low-affinity GABA transporters on isolated brain capillaries or suspended BCECs, with Km1, Km2, Vm1 and Vm2 equal to 25.3 microM, 485.2 microM, 3.6 and 8.4 nmol/5 min/mg protein, respectively, for the capillaries, and 21.3 microM, 322.0 microM, 6.1 and 15.7 nmol/5 min/mg protein, respectively, for the suspended BCECs. In contrast, a single low-affinity transporter was found for monolayers of BCECs attached to plates with Km and Vm equal to 338.7 microM and 18.8 nmol/5 min/mg protein, respectively. Subcellular location of the two distinct transporters on BCECs is discussed, suggesting that the low-affinity GABA transporter is probably localized to the luminal membrane of BCECs, and the high-affinity GABA transporter is probably localized to the antiluminal membrane. Low temperature (4 degreesC) and metabolic inhibitors markedly diminished both high and low-affinity uptakes of [3H]GABA by isolated brain capillaries. The substitution of Na+ with choline+, K+ or Li+ with the counter anion Cl- almost completely abolished both uptakes. Substitution of Cl- with Br-, I-, F- or NO3- in the presence of Na+ significantly reduced both uptakes to different extents. Alanine, leucine, phenylalanine, arginine, glutamate and pyruvate had no obvious effect on either uptake. Probenecid, amino-oxyacetic acid, beta-alanine, taurine, betaine, and nipecotic acid significantly reduced both uptakes. These data suggested that both the GABA transporters at the BBB were temperature, metabolic energy, Na+ and Cl--dependent, and may be specific and different from the known monocarboxylic acid, GABA and other amino acid transporters, which may play a role in the disposition of GABA in the brain.