[A multicenter prospective study on early identification of refractory Mycoplasma pneumoniae pneumonia in children]

Objective: To explore potential predictors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in early stage. Methods: The prospective multicenter study was conducted in Zhejiang, China from May 1st, 2019 to January 31st, 2020. A total of 1 428 patients with fever >48 hours to <120 hours were studied. Their clinical data and oral pharyngeal swab samples were collected; Mycoplasma pneumoniae DNA in pharyngeal swab specimens was detected. Patients with positive Mycoplasma pneumoniae DNA results underwent a series of tests, including chest X-ray, complete blood count, C-reactive protein, lactate dehydrogenase (LDH), and procalcitonin. According to the occurrence of RMPP, the patients were divided into two groups, RMPP group and general Mycoplasma pneumoniae pneumonia (GMPP) group. Measurement data between the 2 groups were compared using Mann-Whitney U test. Logistic regression analyses were used to examine the associations between clinical data and RMPP. Receiver operating characteristic (ROC) curves were used to analyse the power of the markers for predicting RMPP. Results: A total of 1 428 patients finished the study, with 801 boys and 627 girls, aged 4.3 (2.7, 6.3) years. Mycoplasma pneumoniae DNA was positive in 534 cases (37.4%), of whom 446 cases (83.5%) were diagnosed with Mycoplasma pneumoniae pneumonia, including 251 boys and 195 girls, aged 5.2 (3.3, 6.9) years. Macrolides-resistant variation was positive in 410 cases (91.9%). Fifty-five cases were with RMPP, 391 cases with GMPP. The peak body temperature before the first visit and LDH levels in RMPP patients were higher than that in GMPP patients (39.6 (39.1, 40.0) vs. 39.2 (38.9, 39.7) ℃, 333 (279, 392) vs. 311 (259, 359) U/L, both P<0.05). Logistic regression showed the prediction probability π=exp (-29.7+0.667×Peak body temperature (℃)+0.004×LDH (U/L))/(1+exp (-29.7+0.667×Peak body temperature (℃)+0.004 × LDH (U/L))), the cut-off value to predict RMPP was 0.12, with a consensus of probability forecast of 0.89, sensitivity of 0.89, and specificity of 0.67; and the area under ROC curve was 0.682 (95%CI 0.593-0.771, P<0.01). Conclusion: In MPP patients with fever over 48 to <120 hours, a prediction probability π of RMPP can be calculated based on the peak body temperature and LDH level before the first visit, which can facilitate early identification of RMPP.

[Study of the risk factors for recurrence of early and late stage hepatocellular carcinoma after hepatic artery embolization combined with radiofrequency ablation therapy]

Objective: To investigate the risk factors for recurrence of early and late stage hepatocellular carcinoma after receiving hepatic artery embolization combined with radiofrequency ablation therapy. Methods: 246 cases with hepatocellular carcinoma who underwent hepatic artery embolization combined with radiofrequency ablation in Beijing You'an Hospital Affiliated to Capital Medical University from January 2006 to January 2011 were selected. Clinical and follow-up data were collected. Univariate Cox analyses was used to determine the factors influencing recurrence of early and late stage HCC after hepatic artery embolization combined with radiofrequencies ablation. Multivariate Cox regression analysis was used to determine the independent factors. Results: 246 case with hepatocellular carcinoma were treated with hepatic artery embolization combined with radiofrequency ablation, with median follow-up time of 99 months. A total of 179 cases had recurrence and 67 cases had no recurrence. Considering 24 months as the limit, 95 cases had early recurrence and 84 cases had late recurrence. The 1-, 2-, 3-, 5-, and 10-year recurrence rates were 21.3%, 39.0%, 53.0%, 67.3%, and 77.6%, respectively. Multivariate Cox regression analysis showed that the maximum tumor diameter (HR = 2.183, 95% CI: 1.414-3.369, P < 0.01) and tumor number (HR = 1.681, 95% CI: 1.110-2.545, P < 0.05) were independent factor influencing recurrence of early stage HCC after hepatic artery embolization combined with radiofrequency ablation. Liver cirrhosis (HR = 0.421, 95% CI: 0.272-0.651, P < 0.01) was an independent factor influencing recurrence of late stage HCC after hepatic artery embolization combined with radiofrequency ablation. Conclusion: Tumor diameter and number are independent factors influencing recurrence of early stage HCC, while liver cirrhosis is an independent factor influencing recurrence of late stage HCC after hepatic artery embolization combined with radiofrequency ablation therapy.

[A prospective study of the effect and mechanism of autologous platelet-rich plasma combined with Meek microskin grafts in repairing the wounds of limbs in severely burned patients]

Objective: To observe the effect of autologous platelet-rich plasma (PRP) combined with Meek microskin grafts in repairing the wounds of limbs in severely burned patients, and to explore the mechanism. Methods: The prospective controlled research method was used. From September 2016 to January 2020, 16 patients aged 18-69 years, with extensive deep burns, including 9 males and 7 females, who met the selection criteria were admitted to the Department of Burns and Plastic Surgery of the 909th Hospital of the Joint Logistic Support Force of PLA. The bilateral limbs with similar injury in 8 patients were divided into Meek skin grafting+PRP group and Meek skin grafting alone group according to the random number table; in the other 8 patients, the limbs with severer injury were included in Meek skin grafting+PRP group, and the limbs on the other side were included in Meek skin grafting alone group. The wounds of affected limbs in the two groups were treated correspondingly. On post surgery day (PSD) 10, the survival and fusion of Meek microskin grafts were observed and the survival rate and fusion rate were calculated; the histological morphology and the angiogenesis of the basal tissue of Meek microskin graft were observed by hematoxylin-eosin staining and immunohistochemical staining, respectively, with the microvessels being counted. Data were statistically analyzed with paired sample t test. Results: On PSD 10, the wounds of affected limbs in Meek skin grafting+PRP group were dry, and most of the transplanted skin grafts were closely adhered to the basal tissue; while a small amount of exudate could be found in the wounds of affected limbs in Meek skin grafting alone group, and a small part of the transplanted microskin grafts fell off or poorly attached to the basal tissue. On PSD 10, the survival rate and the fusion rate of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting+PRP group were (94±3)% and (86±4)%, which were significantly higher than (89±4)% and (79±4)% of Meek skin grafting alone group, respectively (t=3.633, 4.229, P<0.01). On PSD 10, the basal epidermis was closely connected with dermis of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting+PRP group, with more inflammatory cell infiltration and active microvascular hyperplasia, while the basal epidermis was less closely connected with dermis of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting alone group, with obvious degeneration of collagen fibers under the dermis, less inflammatory cell infiltration, and slightly poor microvascular hyperplasia. On PSD 10, the distribution of microvessels in basal tissue of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting+PRP group were densely clustered, while the distribution of microvessels in Meek skin grafting alone group were scattered, sparse, and dotted. On PSD 10, the number of microvessels in basal tissue of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting+PRP group was 36±6 in each 400-fold visual field, which was significantly more than 29±7 of Meek skin grafting alone group (t=2.671, P<0.05). Conclusions: Autologous PRP can effectively promote the survival rate and fusion rate of Meek microskin grafts in the wounds of limbs after escharectomy in severely burned patients by promoting angiogenesis at the base of Meek microskin grafts.

[Development and clinical application of custom-made temporomandibular joint-skull base combined prosthesis]

Objective: To introduce the design, manufacture and clinical application of the custom-made temporomandibular joint (TMJ)-skull base combined prosthesis and evaluate its safety, effectiveness and accuracy. Methods: The patients diagnosed with the TMJ-skull base lesion in Department of Oral Surgery, Shanghai Ninth People's Hospital from October 2016 to November 2020 were recruited in this study. The maxillofacial CT data for all the patients were obtained and transformed into the Mimics 18.0 software preoperatively. The custom-made TMJ-skull base combined prosthesis, included four components, was designed based on the anatomy, stress distribution and movement of the TMJ and skull base, and fabricated by three-dimensional printing and 5-axis milling technologies. The TMJ-skull base lesion was excised completely with the help of digital templates from modified preauricular and/or post and submandibular incisions. The combined prosthesis were implanted and fixed after the lesion resection. The examinations including general situation, cranio-maxillofacial structure and function were taken during and after surgery to assess its using effect. Results: Ten patients [6 females and 4 males, (43.2±13.6) years old] were included and all prostheses were positioned accurately and fixed excellently. After (29.4±17.3) months follow-up, the occlusion relationship was stable and no adverse symptoms such as dizziness, headache, meningeal irritation and permanent facial nerve injury occurred. The pain, diet, mandibular movement function, lateral movement to diseased side and mouth opening had significant improvements. The forward movement and lateral movement to normal side were not improved significantly. There were no prosthesis displacement, loosening and fracture in X-ray and CT postoperatively. With the pre and postoperative craniomaxillofacial model merging, the maximal implanted error was (0.52±0.17) mm for fossa and condyle and (1.62±0.26) mm for skull base and mandibular handle in surface deviation analysis. Conclusions: The custom-made TMJ-skull base combined prosthesis with customized design and 3D printing fabrication is safe, effective and precise in clinical application.

[Lee T'ao: the pioneer of educator and researcher of Chinese medical history]

Lee T'ao(1901-1959),studied at Beijing National Medical Institute in 1921.He worked at the Chinese Department of Concord Medical Institute from 1928-1942. He studied medical history and taught the history of western and Chinese medicines. He finished Medical History Profile in 1940.During this period, he and Concord Medical Institute collaborated to collect Chinese medical books, therefore he became one of Chinese Medical Association. After 1946, he worked at Medical School of Beijing University (later change its name into Beijing Medical Institute), and he was professor, lead of Medical Teaching and Research Office. He also joined the Editorial department of the Chinese Journal of Medical History, and edited the list of western and Chinese medical books. He published many papers of the Chinese medical history, which had broad vision and novel viewpoint. For the teaching and research, he focused on fieldwork, and physical cultural and historical relics. He investigated and surveyed some high valuable historical relics of medicine that belonged to many of Chinese dynasties. In 1954, he also worked as a lead at the office of medical history for Chinese Central Research Institute. In 1956, he collaborated with Chen Bangxian, teaching the advanced classes for the teachers. He trained many medical history researchers and teachers.

[Study on themisprints of the primary version of the Compendium of Materia Medica]

The Jinling version of the Compendium of Materia Medica was the primary version.It accurately represented the ideas of LI Shizhen, therefore it was valued by the scholars.There were many defects in misprint (knife carving) and proofreading.The main errors were some Chinese character's strokes missing and wrong characters printed.The authors collected some statistics data andmade some statistical analysis. They found that total misprints were 376 and emerge 615 times.Those misprints can divide into two categories: lack of some parts of Chinese characters; lack of some strokes of Chinese characters.Four tables which list the misprints was made.It is helpful for scholars to examine Compendium of Materia Medica or the study of other similar ancient literatures.

Digital cutting guide and endoscopically-assisted vertical ramus osteotomy to treat condylar osteochondroma: a long-term study

We have introduced an effective treatment for mandibular condylar osteochondroma with a digital cutting guide and endoscopically-assisted vertical ramus osteotomy (VRO). Eleven patients with unilateral condylar osteochondroma, who did not require orthognathic surgery or had less than 3mm deviation of the chin and a stable occlusion, were treated during the period April 2013-January 2017 with a digital cutting guide and endoscopically-assisted VRO. Clinical data collected included the occlusion, facial contour, and maximum mouth opening (MMO). Computed tomographic (CT) scans were taken before and after operation. Two patients also had additional shaping of the mandibular contour. The pathological diagnosis was confirmed to be osteochondroma in all cases. A mean (range) 19 (12-40) months of follow-up for all 11 cases showed stable postoperative occlusion and facial aesthetics. There were no functional disturbances, recurrence, or condylar absorption. VRO is an alternative to orthognathic surgery for patients with osteochondroma who do not have severe malocclusions. The digital cutting guide and endoscopically-assisted VRO make it possible to achieve precise resection of the tumour and maintain the occlusion with minimal invasion.

Select antibiotics in leachate from closed and active landfills exceed thresholds for antibiotic resistance development

Though antibiotic resistance (ABR) represents a major global health threat, contributions of landfill leachate to the life cycle of antibiotics and ABR development are poorly understood in rapidly urbanizing regions of developing countries. We selected one of the largest active landfills in Asia and two landfills that have been closed for 20 years to examine antibiotic occurrences in leachates and associated hazards during wet and dry season sampling events. We focused on some of the most commonly used human antibiotics in Hong Kong, one of the most populous Asian cities and the fourth most densely populated cities in the world. Seven antibiotics (cephalexin [CLX], chloramphenicol [CAP], ciprofloxacin [CIP], erythromycin [ERY], roxithromycin [ROX], trimethoprim [TMP], sulfamethoxazole [SMX]) were quantitated using HPLC-MS/MS generally following previously reported methods. Whereas CLX, CAP, ROX and SMX in leachates did not exceed ABR predicted no effect concentrations (PNECs), exceedances were observed for CIP, ERY and TMP in some study locations and on some dates. In fact, an ABR PNEC for CIP was exceeded in leachates during both sampling periods from all study locations, including leachates that are directly discharged to coastal systems. These findings highlight the importance of developing an advanced understanding of pharmaceutical access, usage and disposal practices, effectiveness of intervention strategies (e.g., leachate treatment technologies, drug take-back schemes), and contributions of landfill leachates to the life cycle of antibiotics and ABR development, particularly in rapidly urbanizing coastal regions with less advanced waste management systems than Hong Kong.

Apocynin Attenuates Cerebral Infarction after Transient Focal Ischaemia in Rats

This study investigated whether inhibition of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase attenuates cerebral infarction after transient focal ischaemia in rats. Focal ischaemia (1.5 h) was produced in male Sprague-Dawley rats (250 − 280 g) by middle cerebral artery occlusion. Some rats also received treatment with 50 mg/kg apocynin, a NADPH oxidase inhibitor, by intraperitoneal injection 30 min prior to reperfusion. Two hours after reperfusion, brains were harvested to measure NADPH oxidase activity and superoxide levels. After 24 h, the remaining brains were harvested to investigate infarct size. NADPH oxidase activity and superoxide level were all augmented 2 h after reperfusion compared with controls. Apocynin treatment significantly reduced NADPH oxidase activity and superoxide levels. Cerebral infarct size was significantly smaller in the apocynin-treated group compared with those undergoing ischaemia/reperfusion alone. These results indicate that inhibition of NADPH oxidase attenuates cerebral infarction after transient focal ischaemia in rats, suggesting that inhibition of NADPH oxidase may provide a therapeutic strategy for ischaemic stroke.

[Efficacy evaluation and exploration of TACE combined with CT-guided precision microwave ablation treatment for primary liver cancer]

OBJECTIVE

To analyze the clinical therapeutic efficacy of transcatheter arterial chemoembolization combined with CT-guided percutaneous precision microwave ablation for the treatment of primary liver cancer and its influencing factors.

METHODS

A total of 126 patients with primary liver cancer were treated by transcatheter arterial chemoembolization combined with CT-guided percutaneous precision microwave ablation from Mar 2010 to Oct 2014 in our center. The treatment effect, postoperative complications and recurrence rates were observed, and the factors related to recurrence and survival time were analyzed.

RESULTS

All 126 primary liver cancer patients with 201 tumors were ablated for 177 times, and 113 cases with 185 tumors were completed ablated, the complete ablation rate was 92.0%. In all patients, 4 cases had serious complications, the incidence rate was 3.2%. 37 cases had recurrence, with a recurrence rate of 29.4%. All patients were followed up for 10 to 65 months, 17 patients died, and the 1-, 2-, and 3-year cumulative survival rates were 95.2%, 88.1%, and 84.1%, respectively, and the 1-, 2-, and 3-year progression-free-survival rates were 81.5%, 62.7% and 49.2%, respectively .Univariate analysis showed that preoperative AFP level, Child-Pugh score, BCLC stage and the largest tumor size were associated with the survival of patients who received TACE combined with CT-guided precision MWA, and the preoperative AFP level, internal medicine therapy, tumor number and the largest tumor size were associated with the progression-free-survival after the treatment (P<0.05). Multivariate analysis showed that Child-Pugh score and BCLC stage were independent factors affecting the survival of patients with primary liver cancer patients treated with TACE combined with CT guided percutaneous MWA, and the tumor number and the maximum tumor size were independent factors affecting the progression-free-survival of the patients (P<0.05).

CONCLUSION

TACE combined with CT-guided percutaneous precision microwave ablation therapy for primary liver cancer has reliable safety and efficacy.

Genetic variability of ERCC1 and ERCC2 influences treatment outcomes in gastric cancer

We performed a study to investigate the role of ERCC1 (rs11615, rs2298881, and rs3212986) and ERCC2 (rs13181, rs238406, and rs1799793) polymorphisms in the prognosis of gastric cancer. A total of 346 patients with gastric cancer were recruited between May 2009 and May 2012. Single nucleotide polymorphism genotyping was performed using the Sequenom MassARRAY platform. The GA+AA genotype of ERCC2 rs1799793 showed significant and favorable response to chemotherapy than the wide-type GG genotype in multivariate analysis (OR = 1.78, 95%CI = 1.13-2.81). In a Cox proportional hazard model, carriers of ERCC2 rs1799793 GA+AA genotype exhibited longer duration of survival than did those with the GG genotype (hazards ratio = 0.57, 95%CI = 0.35-0.92). In conclusion, our study suggests that ERCC2 rs1799793 polymorphic variation could be used as a predictor for the prognosis of gastric cancer.

Correlation between the disc status in MRI and the different types of traumatic temporomandibular joint ankylosis

OBJECTIVES

We aimed to investigate the correlation between the disc status in MRI and the different types of traumatic temporomandibular joint (TMJ) ankylosis.

METHODS

51 consecutive patients (69 joints), diagnosed with traumatic TMJ ankylosis with a residual condyle (Types A2 and A3), were included in this study. All patients had pre-operative MRI, which was reviewed to determine the disc shape, length and position. The results were compared using the Mann-Whitney test.

RESULTS

There were 37 joints of Type A2 ankylosis and 32 joints of Type A3. All joints of Type A2 and 27 joints of Type A3 (84.4%) definitely had a discernible disc, while 5 joints of Type A3 had no discernible discs. Among the discernible discs, the lateral disc of Type A2 and the whole disc of Type A3 had severe deformity, while the medial disc of Type A2 had mild deformity. The mean (standard deviation) disc length was 10.88 (1.19) mm in Type A2, but 7.50 (0.82) mm in Type A3. There was a significant difference between Types A2 and A3 (p < 0.05). As for the disc position, the intermediate position was found in all joints.

CONCLUSIONS

There is a correlation between the disc status and the different types of traumatic TMJ ankylosis. Therefore, MRI examination is needed to help treatment planning and predict post-operative TMJ function.

Transcatheter arterial chemoembolization combined with radiofrequency ablation can improve survival of patients with hepatocellular carcinoma with portal vein tumour thrombosis: extending the indication for ablation?

AIM

To retrospectively assess long-term survival benefit and safety of transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) patients with portal vein tumour thrombosis (PVTT), and to evaluate factors that significantly affect outcomes of these patients.

MATERIALS AND METHODS

One hundred and thirty-four HCC patients (118 men and 16 women; mean age 54.8 years, range 26-79 years) with PVTT were retrospectively assessed. Patients were treated with TACE combined with RFA. Data analysed included patient demographics, liver volume, Child-Pugh score, and Cancer of the Liver Italian Programme (CLIP) score and imaging findings. Survival time (from occurrence of PVTT to last follow-up) was calculated using the Kaplan-Meier method, predictive factors and its correlation with survival was assessed using the multivariate Cox proportional hazards regression method.

RESULTS

The median overall survival (OS) time was 29.5 months (range 16.6-42.4 months), the 1, 3, and 5 year OS were 63%, 40%, and 23%. Cox hazards regression analysis revealed that functional remnant liver volume (FRLV), remnant liver volume (RLV)/total liver volume (TLV), radiation, tumour number, vascular endothelial growth factor (VEGF) distribution, and gross type were the only independent predictive factors of outcome (p = 0.039, 0.010, 0.009, 0.034, 0.031, and 0.000, respectively).

CONCLUSION

TACE combined with RFA was found to be an effective therapy, FRLV and RLV/TLV have close correlation with survival for HCC patients with PVTT type I, II, or partial III and Child-Pugh A or B.

Bisphenol A (BPA) in China: a review of sources, environmental levels, and potential human health impacts

Bisphenol A (BPA), identified as an endocrine disruptor, is an industrially important chemical that is used as a raw material in the manufacture of many products such as engineering plastics (e.g., epoxy resins/polycarbonate plastics), food cans (i.e., lacquer coatings), and dental composites/sealants. The demand and production capacity of BPA in China have grown rapidly. This trend will lead to much more BPA contamination in the environmental media and in the general population in China. This paper reviews the current literature concerning the pollution status of BPA in China (the mainland, Hong Kong, and Taiwan) and its potential impact on human health. Due to potential human health risks from long-term exposure to BPA, body burden of the contaminant should be monitored.

Detection of Helicobacter in the fecal material of the endangered Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis

In animals, infection by the Epsilonproteobacteria Helicobacter spp. and H. cetorum is widespread. It has been suggested that H. cetorum may cause gastritis in cetaceans. The aim of our study was to investigate the presence of Helicobacter spp. in the fecal material of the endangered Yangtze finless porpoise Neophocaena phocaenoides asiaeorientalis. The fecal material of 12 porpoises living in the wild in Poyang Lake and 1 porpoise living in captivity at the Wuhan Baiji Dolphinarium were examined by PCR for the presence of Helicobacter spp. The fecal material of 8 of 12 wild porpoises and the captive porpoise were positive for Helicobacter spp. as determined by PCR using Helicobacter-specific primers, which target the 16S rRNA gene. A 16S rRNA clone library was then prepared from 1 sample isolated from a female porpoise living in the wild. DNA sequence analysis from 3 of the clones showed 98 to 99% identity to the H. cetorum 16S rRNA gene. These results demonstrate the prevalence of Helicobacter spp. and H. cetorum in endangered freshwater finless porpoises.

Isolated primary non-Hodgkin's lymphoma of the thoracic spine: a case report with a review of the literature

A case of isolated primary non-Hodgkin's lymphoma of the spine is presented along with a review of previous cases reported in the literature. An 80-year old immunocompetent man was admitted with progressive numbness and weakness of both lower extremities of 2 weeks' duration. Magnetic resonance imaging (MRI) of the cervicothoracic spine revealed an extradural spinal mass at the T1 - T3 level, with invasion into the T3 vertebral body. The lesion was at first thought to be a metastatic tumour. Because of the manifestations of compression, the patient underwent laminectomy and posterior decompression. Histopathological examination revealed diffuse large B-cell non-Hodgkin's lymphoma. All other investigations (including computed tomography of the chest and abdomen, bone scan, peripheral blood examination and tumour marker examination) were negative for occult disease. This case demonstrates that neurosurgeons should be aware of the occurrence of isolated primary spinal lymphoma, which should be included in the differential diagnosis of metastatic tumours.

Treatment of Intracerebral Glioblastomas with G422 Tumour Cell Vaccine in a Mouse Model

The aim of this study was to develop a tumour vaccine with the ability to induce and expand higher affinity cytotoxic T lymphocytes and stimulate an effective antitumour immune response. The hypothesis tested was that G422 glioblastoma cells modified with B7-1 and interferon (IFN)-γ genes could serve as a tumour vaccine. It was found that therapeutic subcutaneous immunizations with this tumour vaccine significantly induced a cytotoxic T-cell response and prolonged the survival of female Kuming mice with intracerebral G422 tumour isografts. The data collectively suggested that G422 glioblastoma cells genetically modified with B7-1 and IFN-γ genes could serve as a tumour vaccine.

Exposure to polybrominated diphenyl ethers associated with consumption of marine and freshwater fish in Hong Kong

Concentrations of polybrominated diphenyl ethers (PBDEs) in market fish have not previously been reported in Hong Kong. Axial and ventral muscles from 10 each common species of freshwater and marine fish purchased from markets in Hong Kong were analyzed for 22 PBDEs. Among the 10 freshwater fish species, spotted snakehead (Channa maculate) contained the highest level of PBDEs in ventral muscle (130 ng g(-1) wet wt.). For marine fish, bigeye (Priacanthus macracanthus) showed significantly higher levels of PBDEs (60.7 ng g(-1)wet wt. in ventral tissue) than all other marine species. The levels of PBDEs in fish samples ranged from 0.53 to 130 ng g(-1)wetwt. The tetrabrominated congener BDE-47 and pentabrominated BDE-99 were the predominant congeners, which accounted for 27% and 30%, respectively, of the total PBDEs. Daily PBDE intake was calculated according to the different fish consumption rate for Hong Kong consumers, and the results ranged from 222 to 1198 ng day(-1) for marine fish and 403-2170 ng day(-1) for freshwater fish. The daily PBDE intake from fish reported here were higher than those reported from the United States (8.94-15.7 ng day(-1)) and Europe (14-23.1 ng day(-1)).

Distribution of PBDEs in air particles from an electronic waste recycling site compared with Guangzhou and Hong Kong, South China

Air samples of total suspended particles (TSP, particles less than 30-60 microm), and particles with aerodynamic diameter smaller than 2.5 microm (PM(2.5)) were collected simultaneously at Guiyu (an electronic waste recycling site), three urban sites in Hong Kong and two urban sites in Guangzhou, South China from 16 August to 17 September 2004. Twenty-two PBDE congeners (BDE-3, -7, -15, -17, -28, -49, -71, -47, -66, -77, -100, -119, -99, -85, -126, -154, -153, -138, -156, -184, -183, -191) in TSP and PM(2.5) were measured. The results showed that the overall average concentrations of TSP and PM(2.5) collected at Guiyu were 124 and 62.1 microg m(-3), respectively. The monthly concentrations of the sum of 22 BDE congeners contained in TSP and PM(2.5) at Guiyu were 21.5 and 16.6 ng m(-3), with 74.5 and 84.3%, contributed by nine congeners (BDE-28, -47, -66, -100, -99, -154, -153, -183 and -191 respectively). This pattern was similar to Tsuen Wan site of Hong Kong. Two urban sites of Guangzhou had the same congener pattern, but were different from Yuen Long and Hok Tsui sites of Hong Kong. The results also showed that the amount of mono to penta brominated congeners, which are more toxic, accounted for 79.4-95.6% of Sigma(22)PBDEs from all sites. All congeners tested in Guiyu were up to 58-691 times higher than the other urban sites and more than 100 times higher than other studies reported elsewhere. The higher concentration in the air was due to heating or opening burning of electronic waste since PBDEs are formed when plastics containing brominated flame retardants are heated.

Human health risk assessment of organochlorines associated with fish consumption in a coastal city in China

Food consumption is an important route of human exposure to organochlorines (OCs). In order to assess the potential health risks associated with these contaminants due to fish consumption, five species of fish were collected from a local market in Zhoushan City, an island in the East China Sea. Dioxin-like compounds, such as polychlorinated dibenzo-p-dioxins/ dibenzofurans, in the fish samples were screened by H4IIE-luc cell bioassay, and the concentrations of specific organochlorines were measured by gas chromatograph-electron capture detector (GC-ECD). The bioassay results indicated that concentrations of dioxin-like compounds in the fish samples were below detection limit (0.64 pg/mL). The concentrations of OC pesticides and PCBs ranged from 0.67 to 13 and 0.24 to 1.4 ng/g wet wt., respectively. Significantly, concentrations of p,p'-DDE in fish meat were comparatively high (average 3.9 ng/g wet wt.) compared with the other OC pesticides. The daily fish consumption, based on a dietary survey conducted among 160 local healthy residents, was determined to be 105 g/person. The relevant cancer benchmark concentrations of HCB, dieldrin, chlordane, DDTs and PCBs were 0.36, 0.04, 1.6, 1.7, and 0.29 ng/kg per day, respectively, based on the local diet. The hazard ratios (HRs), based on non-cancer endpoints were all less than 1.0, while the HRs based on cancer were greater than 1.0 for certain contaminants based on the 95th centile concentration in fish tissue.

Myocardial retinoid X receptor, thyroid hormone receptor, and myosin heavy chain gene expression in the rat during adult aging

Although previous studies have shown that cardiac myosin heavy chain (MHC) composition undergoes a switch from the alpha- to beta-isoform in the heart during adult aging, the underlying mechanisms responsible for this switch are unknown. Cardiac MHC gene expression is regulated, in part, by thyroid hormone responsive elements present in the regulatory control regions of the alpha- and beta-MHC genes. Age-associated changes in the expression of thyroid hormone receptors (THRs) and/or retinoid X receptors (RXRs), the heterodimeric partner for THRs, could explain the age-associated changes in MHC expression. Accordingly, we measured mRNA levels for the cardiac muscle MHCs and the rat THR and RXR genes in the left ventricles of Wistar rats at 2, 6, and 24 months of age. Although there were no significant changes in RXR alpha or RXR beta mRNA levels with age, both alpha 1 and alpha 2 THR mRNA levels decreased significantly between 2 and 6 months of age. During this same time period, the mRNA levels for alpha-MHC declined by more than half, whereas beta-MHC mRNA levels remained low and unchanged. On the other hand, between 6 and 24 months, when mRNA levels for beta-MHC increased and alpha-MHC continued to decrease, there was a significant decline in THR beta 1 and RXR gamma mRNA levels accompanied by a reduction in the THR beta 1 and RXR gamma protein levels. These data show a pattern of change that suggests that the decline in alpha-MHC gene expression may be biphasic and due to a decline in alpha 1 (and possibly alpha 2) THR levels between 2 and 6 months of age and a decline in THR beta 1 and RXR gamma levels at later stages. In contrast, the increase in beta-MHC gene expression was associated only with the changes in THR beta 1 and RXR gamma mRNA and protein levels.

Stimulation of P2Y receptors activates c-fos gene expression and inhibits DNA synthesis in cultured cardiac fibroblasts

OBJECTIVES

The aims of this study were to determine (1) whether neonatal rat cardiac fibroblasts (CAFB) express P2Y receptors; (2) whether CAFB respond to extracellular ATP by inducing expression of c-fos mRNA; and (3) whether extracellular ATP modulates norepinephrine (NE)-stimulated cell growth in CAFB.

METHODS

Expression of P2Y1 and P2Y2 receptors and induction of c-fos were examined by Northern blot analysis. CAFB growth was assessed by measuring [3H]thymidine incorporation and DNA content. P2Y receptor pharmacology was studied using various ATP analogues.

RESULTS

Northern blot analysis of polyA enriched RNA confirmed that at least 2 subtypes of P2Y receptors (P2Y1 and P2Y2) are expressed in cultured CAFB. Extracellular ATP induced the expression of c-fos mRNA through a pathway that was sensitive to inhibitors of protein kinase C (PKC), but not to inhibitors of intracellular Ca2+ signaling. Extracellular ATP inhibited the NE-stimulated increases in DNA content and in [3H]thymidine incorporation into DNA. Whereas the potency order for stimulation of c-fos expression was ATP = UTP > ADP > adenosine, the potency order to inhibit the NE-induced increase of [3H]thymidine incorporation into DNA was ATP > ADP > UTP > adenosine.

CONCLUSIONS

These data demonstrate that CAFB express both P2Y1 and P2Y2 receptor mRNA and that CAFB respond to P2Y receptor stimulation by induction of c-fos and inhibition of DNA synthesis. These findings suggest that the effects of ATP on [3H]thymidine incorporation into DNA and on expression of c-fos mRNA are exerted via distinct P2Y receptor subtypes.

Rapamycin inhibits alpha 1-adrenergic receptor-stimulated cardiac myocyte hypertrophy but not activation of hypertrophy-associated genes. Evidence for involvement of p70 S6 kinase

The 70-kD S6 kinase (p70S6K) has been implicated in the regulation of protein synthesis in many cell types and in the angiotensin II-stimulated hypertrophy of cardiac myocytes. Our purpose was to determine whether p70S6K plays a role in cardiomyocyte hypertrophy induced by the alpha 1-adrenergic receptor (alpha 1-AR) agonist phenylephrine (PE). PE stimulated the activity of p70S6K > 3-fold, and this increase was blocked by rapamycin, an immunosuppressant macrolide that selectively inhibits p70S6K. When administered for 3 days, PE stimulated a 30% increase in total protein content, a 2-fold increase in the incorporation of [14C]phenylalanine (14C-Phe) into protein, and a 50% increase in two-dimensional myocyte area. Rapamycin pretreatment (> or = 500 pg/mL) significantly inhibited each of these PE-stimulated changes. Two days of PE treatment resulted in a 1.6-fold increase in total RNA yield per dish, a 2-fold increase in incorporation of [14C]uridine into myocyte RNA, and increases in relative mRNA levels of the hypertrophy-associated atrial natriuretic factor (ANF, 2.1-fold) and skeletal alpha-actin (SK, 2.2-fold) genes. Although rapamycin abolished the PE-stimulated increases in total RNA and incorporation of [14C]uridine, it had no effect on the induction of the ANF and SK genes. LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3-K) activity, inhibited PE-stimulated increases in p70S6K activity and the incorporation of labeled precursors into myocyte protein and RNA. These results demonstrate that p70S6K is activated by the hypertrophic agent PE and that a PI3-K or PI3-K-like activity is required for p70S6K activation and myocyte hypertrophy. The data suggest that p70S6K activation may be required for PE-stimulated hypertrophy of cardiac myocytes. Our results demonstrate that intracellular signaling pathways responsible for transcriptional and translational responses diverge early after alpha 1-AR stimulation in cardiac myocytes.

p53 and the hypoxia-induced apoptosis of cultured neonatal rat cardiac myocytes

Myocyte cell loss is a prominent and important pathogenic feature of cardiac ischemia. We have used cultured neonatal rat cardiac myocytes exposed to prolonged hypoxia as an experimental system to identify critical factors involved in cardiomyocyte death. Exposure of myocytes to hypoxia for 48 h resulted in intranucleosomal cleavage of genomic DNA characteristic of apoptosis and was accompanied by increased p53 transactivating activity and protein accumulation. Expression of p21/WAF-1/CIP-1, a well-characterized target of p53 transactivation, also increased in response to hypoxia. Hypoxia did not cause DNA laddering or cell loss in cardiac fibroblasts. To determine whether the increase in p53 expression in myocytes was sufficient to induce apoptosis, normoxic cultures were infected with a replication-defective adenovirus expressing wild-type human p53 (AdCMV.p53). Infected cells expressed high intracellular levels of p53 protein and exhibited the morphological changes and genomic DNA fragmentation characteristic of apoptosis. In contrast, no genomic DNA fragmentation was observed in myocytes infected with the control virus lacking an insert (AdCMV.null) or in cardiac fibroblasts infected with AdCMV.p53. These results suggest that the intracellular signaling pathways activated by p53 might play a critical role in the regulation of hypoxia-induced apoptosis of cardiomyocytes.

The number of stenotic coronary arteries and passive smoking exposure from husband in lifelong non-smoking women in Xi'an, China

The relationship between the number of stenotic coronary arteries and passive smoking exposure from the husband was examined in a retrospective study of 78 cases with stenotic coronary arteries and 83 controls with normal coronary arteries. All the 161 subjects were examined by coronary arteriography and were Chinese women who had never smoked cigarettes (i.e. lifelong non-smokers). The Pearson's and Spearman's correlation coefficients between the number of stenotic coronary arteries and passive smoking exposure indices were 0.27-0.29 and 0.25-0.28 (all with P < 0.01), respectively. The linear prediction equations from multiple regression analysis showed that passive smoking exposure, after adjustment for other major risk factors, was a significant predictive variable for the number of stenotic coronary arteries. The multiple response logistic regression model was used to estimate the odds ratio of stenotic coronary arteries for passive smoking exposure categories. The crude and adjusted odds ratios showed that the number of stenotic arteries increased with the amount of exposure to passive smoking from the husband. These results provide new evidence to support that passive smoking is causally associated with coronary heart disease.

Extracellular ATP inhibits adrenergic agonist-induced hypertrophy of neonatal cardiac myocytes

We have previously shown that extracellular ATP, like norepinephrine (NE) and many other hypertrophy-inducing agents, increases expression of the immediate-early genes c-fos and junB in cultured neonatal cardiac myocytes but that the intracellular signaling pathways activated by ATP and responsible for these changes differ from those stimulated by NE. Furthermore, whereas NE increases incorporation of [14C]phenylalanine (14C-Phe) and cell size in neonatal cardiomyocytes, ATP does not. Since ATP is coreleased with NE from sympathetic nerve endings in the heart, we investigated whether ATP could modulate cardiac hypertrophy induced by adrenergic agonists, such as NE. We report in the present study that extracellular ATP inhibited the increase in incorporation of 14C-Phe into cellular protein and the increase in cell size in neonatal rat cardiac myocytes that was induced by NE, phenylephrine (PE), basic fibroblast growth factor, or endothelin-1. This inhibition was dose dependent, occurred predominantly through P2 purinergic receptors, and was observed even when cells were treated with ATP for as little as 1 hour before the addition of the hypertrophy-inducing agent. ATP also selectively affected changes in gene expression associated with hypertrophy. It prevented PE-stimulated increases in atrial natriuretic factor and myosin light chain-2 mRNA levels, while appearing to augment basal and PE-stimulated skeletal alpha-actin mRNA levels. ATP alone increased sarcoplasmic reticulum Ca2+-ATPase mRNA levels but had no effect when added with PE. ATP did not significantly affect the level of the constitutively expressed mRNA for GAPDH. Neither the PE-stimulated increase in immediate-early gene expression nor the initial induction of mitogen-activated protein kinase activity by PE was inhibited by ATP. These results demonstrate that extracellular ATP can inhibit hypertrophic growth of neonatal cardiac myocytes and differentially alter the changes in gene expression that accompany hypertrophy.

Extracellular ATP induces immediate-early gene expression but not cellular hypertrophy in neonatal cardiac myocytes

It is well-documented that norepinephrine (NE) induces the expression of immediate-early genes (IEGs), such as c-fos, c-jun, and jun-B, in cultured neonatal heart cells and leads to cell growth without cell division (ie, hypertrophy). Although purinergic receptors activated by ATP are present on cardiac myocytes and ATP is coreleased with NE from sympathetic nerve endings within the heart, the potential role of the purinergic system in the cascade of events that leads to cardiac hypertrophy is unknown. We report in the present study that stimulation of purinergic receptors by micromolar concentrations of extracellular ATP increased the levels of c-fos and jun-B mRNA as well as FOS and JUN-B proteins in neonatal cardiac myocytes. The magnitude of response to micromolar ATP was comparable to that elicited by NE. The increase in IEG expression induced by ATP was preceded by a rapid transient increase in cytosolic Ca2+. Pretreatment of myocytes with the intracellular Ca2+ chelator BAPTA-AM prevented the ATP-stimulated increase in cytosolic Ca2+ and attenuated the ATP-stimulated increase in c-fos expression. In contrast, NE did not increase cytosolic Ca2+ in quiescent myocytes, and pretreatment with BAPTA-AM did not inhibit the NE-stimulated increase in c-fos gene expression. Furthermore, although NE markedly increased [14C]phenylalanine incorporation into protein and myocyte hypertrophy measured by cell size, ATP did not. These results demonstrate that stimulation of purinergic receptors by ATP activates IEGs via a Ca(2+)-dependent pathway in cardiac myocytes that differs from the NE stimulated activation of these genes.(ABSTRACT TRUNCATED AT 250 WORDS)

Passive smoking at work as a risk factor for coronary heart disease in Chinese women who have never smoked

OBJECTIVE

To study whether passive smoking at work is a risk factor for coronary heart disease.

DESIGN

Case-control study.

SETTING

Xi'an, China.

SUBJECTS

59 patients with coronary heart disease and 126 controls, all Chinese women with full time jobs, who had never smoked cigarettes.

RESULTS

The crude odds ratio for passive smoking from husband was 2.12 (95% confidence interval 1.06 to 4.25) and at work was 2.45 (1.23 to 4.88). The final logistic regression model, with passive smoking from husband and at work as the base, included age, history of hypertension, type A personality, and total cholesterol and high density lipoprotein cholesterol concentrations; the adjusted odds ratios for passive smoking from husband and at work were 1.24 (0.56 to 2.72) and 1.85 (0.86 to 4.00) respectively. For passive smoking at work, statistically significant linear trends of increasing risks (for both crude and adjusted odds ratios) with increasing exposures (amount exposed daily, number of smokers, number of hours exposed daily, and cumulative exposure) were observed. When these exposure variables were analysed as continuous variables, the crude and adjusted odds ratios were also significant.

CONCLUSION

Passive smoking at work is a risk factor for coronary heart disease. Urgent public health measures are needed to reduce smoking and to protect non-smokers from passive smoking in China.

Modulation by extracellular ATP of two distinct currents in rat myocytes

The whole cell voltage-clamp technique was used to study the electrophysiological effects induced by ATP in isolated ventricular myocytes. ATP or 2-methylthio-ATP evoked a transient inward current (IATP) when the transmembrane potential (Vm) was held at -70 mV and increased the Ca2+ current (ICa) when Vm was depolarized to 0 mV. The time course of IATP was fitted by a single exponential equation with a brief time constant (165 ms), whereas the time course of enhancement of ICa by ATP was also fitted by a single exponential equation with a much longer time constant (14 s). IATP was much less pronounced when extracellular Mg2+ was absent, and it was insensitive to dihydropyridines. In contrast, the enhancement of ICa by ATP was not affected by removing extracellular Mg2+, but it was suppressed by Ca2+ channel blockers. Both IATP and ICa were decreased by extracellular Cd2+. Internally applied guanosine 5'-O-(2-thiodiphosphate), which prevents the activation of G proteins, abolished the ATP-enhanced rise in ICa but did not inhibit IATP. These data suggest that ATP elicits IATP and increases ICa through two different mechanisms. IATP appears to be generated via receptor-operated channels that are activated by ATP. The ATP-induced increase of ICa appears to be mediated by G proteins via pathways that are independent of adenosine 3',5'-cyclic monophosphate and phosphoinositide turnover.

Determination of 3-methylflavone-8-carboxylic acid, the main metabolite of flavoxate, in human urine by capillary electrophoresis with direct injection

The effects of tetraalkylammonium salts and sodium dodecyl sulphate on the migration behaviour of human urinary components and other negatively charged or neutral solutes were investigated. The sulphate acted mainly on hydrophobic and positively charged substances, whereas the ammonium salts acted mainly on negatively charged solutes. By choosing the components of the eluent carefully, the free and conjugate forms of 3-methylflavone-8-carboxylic acid (MFA) in human urine, the major metabolites of flavoxate, could be simultaneously determined without pretreatment, using fenprofen as an internal standard. The calibration curve of MFA was linear in the range 1-50 micrograms/ml and the detection limit was 0.2 microgram/ml, which covered the urine levels encountered in pharmacokinetic studies. The intra-day and inter-day precisions of the method, expressed as the relative standard deviation, were less than 2 and 3%, respectively. This method was successfully applied to an excretion study of MFA in eight healthy volunteers, and the results were in agreement with data in the literature obtained by gas chromatography.

Ca2+ mobilization by extracellular ATP in rat cardiac myocytes: regulation by protein kinase C and A

Activation of protein kinase C (PKC) modulates the mobilization of intracellular Ca2+ induced by extracellular ATP in rat ventricular myocytes. Pretreatment of myocytes with PKC activators attenuated both the ATP-induced Ca2+ transient and the noradrenergic potentiation of the Ca2+ response. Various PKC activators decreased both the basal cAMP level and the cAMP levels that had been elevated by norepinephrine, forskolin, or 3-isobutyl-1-methylxanthine. The inhibitory effects of PKC activators were reversed by the PKC inhibitor staurosporine. The ATP-induced Ca2+ response is an integrated response resulting from ATP eliciting an inward cation current (IATP), cellular depolarization, Ca2+ influx through Ca2+ channels, and Ca2+ release from the sarcoplasmic reticulum. We used the whole cell voltage-clamp technique to investigate which steps of this integrated response are affected by PKC. PKC activators did not significantly affect the IATP. In contrast, PKC activators decreased the basal Ca2+ current (ICa) or Ba2+ current and the beta-adrenergic-stimulated ICa. These results suggest that PKC-induced suppression of the ATP-induced Ca2+ response and the beta-adrenergic-potentiated Ca2+ response is achieved at least partially by decreasing the intracellular cAMP level and ICa.

Synergism between cAMP and ATP in signal transduction in cardiac myocytes

ATP transiently increases the intracellular Ca2+ concentration in cardiac myocyte suspensions. Pretreatment with norepinephrine (NE) greatly potentiates the ATP response. We performed experiments on adult rat myocyte suspensions loaded with fura-2 to investigate the mechanism of NE potentiation. We found that forskolin (an activator of adenylate cyclase), 3-isobutyl-1-methylxanthine (an inhibitor of phosphodiesterase), and permeative adenosine 3',5'-cyclic monophosphate (cAMP) analogues potentiate the increase in cytosolic Ca2+ concentration induced by ATP. NE, forskolin, and 8-(4-chlorophenylthio)-cAMP all increase Vmax of the Ca2+ response curve of ATP. Measurement of cAMP by radioimmunoassay confirmed that the changes in the ATP response were accompanied by an increase in cAMP. These results suggest that the noradrenergic potentiation of the ATP-induced Ca2+ mobilization involves cAMP as a second messenger. Patch-clamp studies of isolated myocytes showed that neither NE nor forskolin alters the inward current elicited by ATP, but rather they increase the duration of secondary slow action potentials elicited by ATP. NE also increases the Ca2+ current through L-type Ca2+ channels in the myocytes. We conclude that NE potentiates the ATP-induced Ca2+ transient by increasing cAMP levels and that one of the early events is the increase of the inward Ca2+ current during the action potential.

[Studies on the original plants of nuoteng, hanshuiteng and dahuteng]

By studying the origin of the three herbs: Nuoteng, Hanshuiteng and Dahuteng recorded in medical books before the Tang Dynasty, it has been verified that all these three plants Maimateng (Gnetum montanum) or Xiaoye Maimateng (G. parvifolium).