[Application of synthetic MRI in predicting isocitrate dehydrogenase 1 genotypes in gliomas].

This study analyzed the clinical and imaging data of 81 glioma patients who underwent brain synthetic MRI and diffusion weighted imaging (DWI) examination in the General Hospital of Ningxia Medical University from August 2020 to September 2021 to explore the value of synthetic MRI relaxation quantitative value in predicting the genotype of isocitrate dehydrogenase 1 (IDH1) in gliomas. There were 44 males and 37 females, those patients with an aged 50.0 (36.5, 59.0) years. The tumor pre-T1, pre-T2, pre-PD, post-T1 and ADC values were obtained by outlining the region of interest (ROI). Univariate analysis was used to compare the differences of parameter values between groups, and the receiver operating characteristic was used to evaluate the diagnostic efficacy of each parameter value in predicting glioma IDH1 genotype. The results showed that the pre-T1 and pre-PD values [M (Q1, Q3)] of IDH1m glioma were lower than those of IDH1w glioma [1 462.75 (1 306.41, 1 567.75) ms vs 1 532.83 (1 434.67, 1 617.67) ms, 84.18 (82.28, 86.41) pu vs 85.85 (84.65, 86.90) pu] (all P<0.05). The post-T1 and ADC values of IDH1m glioma were higher than those of IDH1w glioma [1 054.50 (631.92, 1 262.63) ms vs 669.67 (535.17, 823.33) ms, 1.20 (0.86, 1.35) ×10-3 mm2/s vs 0.80 (0.76, 0.93) ×10-3 mm2/s] (all P<0.05). The AUC of the combined model (pre-T1+pre-PD+post-T1+ADC+Age) is 0.828 (95%CI:0.729-0.903). Synthetic MRI relaxation quantitative values are helpful to distinguish IDH1 genotypes in glioma. The diagnostic efficacy of the multi-parameter combined model based on pre-T1, pre-PD, post-T1, ADC, and age is better than that of the single parameter, and it can be used as an effective strategy to improve the differential diagnosis ability of gliomas molecular markers.

[Thoracoscopic laparoscopy-assisted Ivor-Lewis resection of esophagogastric junction cancer].

Objective: To investigate the outcome of patients with esophagogastric junction cancer undergoing thoracoscopic laparoscopy-assisted Ivor-Lewis resection. Methods: Eighty-four patients who were diagnosed with esophagogastric junction cancer and underwent Ivor-Lewis resection assisted by thoracoscopic laparoscopy at the National Cancer Center from October 2019 to April 2022 were collected. The neoadjuvant treatment mode, surgical safety and clinicopathological characteristics were analyzed. Results: Siewert type Ⅱ (92.8%) and adenocarcinoma (95.2%) were predominant in the cases. A total of 2 774 lymph nodes were dissected in 84 patients. The average number was 33 per case, and the median was 31. Lymph node metastasis was found in 45 patients, and the lymph node metastasis rate was 53.6% (45/84). The total number of lymph node metastasis was 294, and the degree of lymph node metastasis was 10.6%(294/2 774). Among them, abdominal lymph nodes (100%, 45/45) were more likely to metastasize than thoracic lymph nodes (13.3%, 6/45). Sixty-eight patients received neoadjuvant therapy before surgery, and nine patients achieved pathological complete remission (pCR) (13.2%, 9/68). Eighty-three patients had negative surgical margins and underwent R0 resection (98.8%, 83/84). One patient, the intraoperative frozen pathology suggested resection margin was negative, while vascular tumor thrombus was seen on the postoperative pathological margin, R1 resection was performed (1.2%, 1/84). The average operation time of the 84 patients was 234.5 (199.3, 275.0) minutes, and the intraoperative blood loss was 90 (80, 100) ml. One case of intraoperative blood transfusion, one case of postoperative transfer to ICU ward, two cases of postoperative anastomotic leakage, one case of pleural effusion requiring catheter drainage, one case of small intestinal hernia with 12mm poke hole, no postoperative intestinal obstruction, chyle leakage and other complications were observed. The number of deaths within 30 days after surgery was 0. Number of lymph nodes dissection, operation duration, and intraoperative blood loss were not related to whether neoadjuvant therapy was performed (P>0.05). Preoperative neoadjuvant chemotherapy combined with radiotherapy or immunotherapy was not related to whether postoperative pathology achieved pCR (P>0.05). Conclusion: Laparoscopic-assisted Ivor-Lewis surgery for esophagogastric junction cancer has a low incidence of intraoperative and postoperative complications, high safety, wide range of lymph node dissection, and sufficient margin length, which is worthy of clinical promotion.

Relationship between inflammatory factors and arrhythmia and heart rate variability in OSAS patients.

OBJECTIVE: Obstructive Sleep Apnea Syndrome (OSAS) is a disorder characterized by recurrent upper airway obstruction, apnea, and hypopnea, associated with decreased oxygen saturation and disturbed sleep structure during sleep. It was found that OSAS was associated with a variety of arrhythmia and conduction disorders, but the relationship between multiple types of arrhythmia and the severity of OSAS, and its possible mechanism remain unclear. The purpose of this study was to observe the main types of arrhythmia and the condition of heart rate variability (HRV) in patients with OSAS, to detect the levels of multiple inflammatory factors in serum of OSAS patients, and to observe the correlation between polysomnographic parameters or inflammatory factors, and arrhythmia or HRV, as well as its possible mechanisms. PATIENTS AND METHODS: 141 patients with suspected OSAS were collected in the Second Affiliated Hospital of Soochow University and Xinghua People's Hospital from February 2016 to February 2018. According to the sleep apnea hypopnea index (AHI), they were divided into control group (AHI <5, n = 34), mild-moderate OSAS group (5≤ AHI <30, n = 48), and severe OSAS group (AHI ≥30, n = 59). Clinical data such as gender and age were collected. All patients completed polysomnography (PSG), 24-hour Holter monitoring and blood routine, biochemical indexes and serum hs-CRP, TNF-α, IL-6, and IL-1ß testing. The indicators in the three groups were compared, and the correlation between PSG parameters, HRV and inflammatory biomarkers was investigated. RESULTS: Compared with control group, there were significant differences in age, sex ratio, BMI, uric acid, TC, and TG in the mild-moderate OSAS group (p<0.05), and in age, sex ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL in severe OSAS group (p<0.05). There were significant differences in gender ratio, BMI, red blood cell count, hemoglobin, hematocrit, uric acid, FBS, TC, TG, LDL, and HDL between mild-moderate OSAS group and severe OSAS group (p<0.05). Heart rate variability (HRV) parameters include SDNN, SDNN index, RMSSD, PNN50, LF, HF, and LF/HF. SDNN, PNN50, and HF in severe OSAS group and mild-moderate OSAS group were significantly lower than those in control group (p<0.05). LF/HF was significantly higher than that of control group (p<0.05). There was a significant difference in PNN50, HF, and LF/HF between severe OSAS group and mild-moderate OSAS group (p<0.05). In terms of inflammation, serum hs-CRP was significantly higher in mild-moderate OSAS group and severe OSAS group than that in control group (p<0.05). Serum IL-1ß was significantly higher in mild-moderate OSAS group than that in severe OSAS group (p<0.05). There was no significant difference in other indicators (p>0.05). There was a significant positive correlation between hs-CRP and oxygen reduction index (ODI) (r=0.209, p=0.013) and a significant negative correlation with PNN50 (r=-0.188, p=0.025). There is no significant correlation between other indicators. CONCLUSIONS: Systemic inflammatory reactions existed in patients with OSAS. With the increase of OSAS, inflammation was aggravated, especially serum hs-CRP. Hs-CRP was significantly and negatively correlated with PNN50 and positively correlated with ODI. The results suggested that the inflammatory response was involved in the occurrence of heart rate variability in OSAS patients.

[Surgical treatment for esophageal cancer during the outbreak of COVID-19].

Since December 2019, unexplained pneumonia has appeared in Wuhan City, Hubei Province, and a new type of coronavirus infection was confirmed as COVID-19. COVID-19 spread rapidly nationwide and abroad. The COVID-19 has brought huge impacts to all the people and walks of life, especially to the medical and health systems. It has also brought great challenges to the treatment of patients with cancer. Esophageal cancer is a common malignant tumor in China and most of the patients are in the middle and advanced stage when diagnosed, with immunosuppressive and poor prognosis. The selection of surgical procedures and perioperative managements of esophageal cancer require all thoracic surgeons work together to figure out a reasonable system of surgical treatment and emergency response.

LINC01503 promotes cell proliferation, invasion and EMT process in cholangio-carcinoma.

OBJECTIVE: This work aimed to analyze the relative expression level of long intergenic non-protein coding ribonucleic acid 1503 (LINC01503) in cholangiocarcinoma tissues and cells, and to explore the effects of LINC01503 on cell proliferation, migration and invasion. PATIENTS AND METHODS: Logarithmic growth phase cholangiocarcinoma cells were selected and transfected with Lipofectamine 2000 (si-LINC01503, si-NC). The expression of LINC01503 was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The proliferation of cells was observed by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was used to detect cell apoptosis. Transwell assay was used to observe the cell migration and invasion ability. RESULTS: The expression of LINC01503 was significantly increased in cholangiocarcinoma tissues compared with adjacent tissues (p<0.05), and the up-regulated expression of LINC01503 was associated with lymph node metastasis. Compared with normal bile duct cells (HIBEC), cholangiocarcinoma cells (RBE, QBC939) have higher expression of LINC01503, and si-LINC01503 transfection can effectively reduce the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of cholangiocarcinoma cells. CONCLUSIONS: LINC01503 is highly expressed in cholangiocarcinoma and can effectively promote the proliferation, migration, invasion and EMT process of cancer cells, and LINC01503 is expected to be a potential biomarker for cholangiocarcinoma.

[Clinical differences between primary nasopharyngeal NK/T-cell lymphoma and primary nasal cavity NK/T-cell lymphoma with nasopharynx extension].

Objective: To investigate the clinical and prognostic differences between primary nasopharyngeal natural killer (NK)/T-cell lymphoma (NP NKTCL) and extranodal NK/T-cell lymphoma of the nasal cavity with nasopharynx extension (N-NP NKTCL). Methods: A total of 89 patients with NP NKTCL and 113 patients with N-NP NKTCL from January 2000 to June 2015 were retrospectively analyzed. Clinical and pathological features, treatment responses and prognosis were compared between the two groups. Results: NP NKTCL patients showed similar clinicopathological features with those with N-NP NKTCL, except that the former had a relative low proportion of elevated lactate dehydrogenase (LDH) levels (28.1% vs. 41.6%; P=0.001). Both of two groups presented with high proportion of cervical lymph node involvement (55.1% and 42.5%; P=0.076). The 5-year overall survival (OS) rates in these two groups were 63.2% and 54.6%, respectively, whereas 5-year progress-free survival (PFS) rates were 50.7% and 45.6%, respectively. For the patients with stage Ⅰ and Ⅱ, the 5-year OS and PFS rates in these two groups were 68.8% and 55.7% as well as 55.6% and 47.2%, respectively. These were no statistically significant differences between two groups (all P>0.05). The complete response (CR) rate after initial chemotherapy in NP NKTCL group was 43.8%, which was significant higher than that of 19.6% in N-NP NKTCL group (P=0.006). Additionally, the CR rate after primary radiotherapy was 63.4% and 62.7%, respectively (P=0.629). The NP NKTCL patients with stage Ⅰ and Ⅱ who accepted radiotherapy with or without chemotherapy had similar survival times with chemotherapy alone, showing the 5-year OS rates of 70.5% and 33.3% (P=0.238), as well as the 5-year PFS rates of 56.7% and 33.3%, respectively (P=0.431). Similar results were found in N-NP NKTCL group, the 5-year OS rates for patients with radiotherapy with or without chemotherapy and chemotherapy alone were 57.4% and 33.3% (P=0.246), while the 5-year PFS rates were 49.3% and 16.7% (P=0.177), respectively. Besides, the relapse pattern of NP NKTCL and N-NP NKTCL groups was also similar, mainly involving the distant extra-nodal organs followed by lymph nodes. Conclusion: The patients with N-NP NKTCL and NP NKTCL showed similar clinical and prognostic features, however, the initial response to chemotherapy was different.

[Screening of the SETX gene in sporadic amyotrophic lateral sclerosis patients of Chinese origin].

Objective: To investigate all coding regions of amyotrophic lateral sclerosis (ALS)-related gene Senataxin (SETX) in sporadic amyotrophic lateral sclerosis patients of Chinese origin. Methods: From January 2010 to December 2014, the peripheral venous blood samples and clinical data were collected from 311 patients with sporadic amyotrophic lateral sclerosis (SALS) and 311 healthy controls who were of Chinese ancestry from the Department of Neurology, Chinese PLA General Hospital.Genomic DNA was extracted from peripheral venous blood of all participants using standard methods. The coding regions of SETX were amplified by polymerase chain reaction (PCR) and screened for mutations using next-generation sequencing technology. The online software SIFT and PolyPhen-2 were used to analyze the conservation of an altered amino acid and predict the potential pathogenicity of identified mutations. The SPSS 22.0 software was used to analyze the clinical feature of all participants. Results: Tenkinds of rare and one novel nonsynonymous mutations were identified and were absent in 311 controls. Twelve (3.86%) patients carried one SETX gene mutation. Five (1.61%) out of above-mentioned 12 patients carried highly pathogenic mutations including p. Pro1868Leu (c.5603G>A), p. Pro1331Leu (c.3992G>A), p. Glu756Val (c.2267T>A), p. Leu564Val (c.1690A>C), and p. Asn144Ser (c.431T>C). Patients carried SETX mutations were not different from other patients in onset age. Conclusion: Mutations in SETX are likely to be a pathogenesis for Chinese sporadic amyotrophic lateral sclerosis.

[Study on the characters of wideband tympanometry in newborns with normal hearing].

Objective:The aim of this study is to establish the characteristic of wideband tympanometry (WBT) in neonates with normal hearing. Method:Ninety newborn babies (149 ears) who had received rooming in care and passed hearing screening were randomly selected to test WBT. The screening programme consisted of distortion product otoacoustic emissions (DPOAE) and tympanometry at 1 kHz. The eigenvalue of ear canal volume, middle ear resonance frequency and acoustic absorptivity were obtained initially to explore the influence of gender and mode of delivery on the eigenvalues. Result:①Ear canal volume: The ear canal volume varied within (0.50±0.12)ml. The statistically significant correlationwas observed between ear canal volume and gender as well as the way of delivery (P<0.01). ②Resonance frequency: the resonant frequency distributed from 128 Hz to 642 Hz (mean 328.2±125.76 Hz). No statistically significant correlation (P>0.05) was observed between resonance frequency and gender as well as the way of delivery. ③Frequency wideband absorbance function: the shape of the curve showed two peaks and two troughs. The three most values were located in 1 296 Hz, 2 000 Hz and 5 339 Hz. No statistically significant correlation (P>0.05) was observed between acoustic absorptivity and gender as well as way of delivery. Conclusion:Resonance frequency and frequency acoustic absorptivity functions of newborns are different from adults. It is necessary to establish the normal reference value of WBT for newborns in China in order to promote this technique in the clinic.

[Analysis of a Chinese Charcot-Marie-Tooth disease type 2D pedigree].

Objective: To achieve definite diagnosis in a clinically diagnosed Charcot-Marie-Tooth disease (CMT) pedigree and broaden the mutational diversity of CMT-related mutations in Chinese Han population. Methods: Patients clinically diagnosed with CMT were recruited from Department of Neurology, Chinese PLA General Hospital between December, 2012 to June, 2016. Clinical examination, laboratory tests, nerve conduction studies, and molecular and bioinformatics analyses were performed on a clinically diagnosed CMT pedigree. Results: In the pedigree, a GARS mutation (c.794C>T, p. S265F) was identified and CMT2D was diagnosed. Conclusion: The newly identified GARS mutation has broaden the mutational diversity of CMT2D in Chinese Han population.

[Clinical outcome of intramyocardial dissecting hematoma after acute myocardial infarction].

Objective: To observe the clinical outcome of intramyocardial dissecting hematoma (IDH) after acute myocardial infarction (MI). Methods: The clinical characteristics and outcomes of nine patients with IDH after acute MI in Beijing Anzhen Hospital from 2010 to 2014 were retrospectively assessed, and all the patients were followed up. Results: The mean age of nine IDH patients (7 males, 2 females) was (61±5) years. One patient was diagnosed as right ventricular IDH and died before surgery because of deteriorated cardiac and renal failure. Eight patients were diagnosed as left ventricular IDH, among whom 1 patient died of perioperative bleeding. The other 7 patients survived, among whom 5 cases were treated medically and 2 cases accepted surgical treatment. After 2-6 years of follow-up, the survived patients had no other complications. Conclusion: IDH after acute MI was a rare clinical event with a high mortality, and improvement of recognition of this rare condition may reduce its mortality, especially the right ventricular IDH.

Comparative evaluation of the therapeutic effect of metformin monotherapy with metformin and acupuncture combined therapy on weight loss and insulin sensitivity in diabetic patients.

OBJECTIVE: Obesity induces insulin resistance (IR), the key etiologic defect of type 2 diabetes mellitus (T2DM). Therefore, an incidence of obesity-induced diabetes is expected to decrease if obesity is controlled. Although Metformin is currently one of the main treatment options for T2DM in obese patients, resulting in an average of 5% weight loss, adequate weight control in all patients cannot be achieved with Metformin alone. Thus, additional therapies with a weight loss effect, such as acupuncture, may improve the effectiveness of Metformin.Subjective:We designed this randomized clinical trial (RCT) to compare the effects of Metformin monotherapy with that of Metformin and acupuncture combined therapy on weight loss and insulin sensitivity among overweight/obese T2DM patients, to understand whether acupuncture plus Metformin is a better approach than Metformin only on treating diabetes. To understand whether acupuncture can be an insulin sensitizer and, if so, its therapeutic mechanism. RESULTS: Our results show that Metformin and acupuncture combined therapy significantly improves body weight, body mass index (BMI), fasting blood sugar (FBS), fasting insulin (FINS), homeostasis model assessment (HOMA) index, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), leptin, adiponectin, glucagon-like peptide-1 (GLP-1), resistin, serotonin, free fatty acids (FFAs), triglyceride (TG), low-density lipoprotein cholesterol (LDLc), high-density lipoprotein cholesterol (HDLc) and ceramides. CONCLUSIONS: Consequently, Metformin and acupuncture combined therapy is more effective than Metformin only, proving that acupuncture is an insulin sensitizer and is able to improve insulin sensitivity possibly by reducing body weight and inflammation, while improving lipid metabolism and adipokines. As a result, electro-acupuncture (EA) might be useful in controlling the ongoing epidemics in obesity and T2DM.

Prevalence of Bilateral Involvement in Patients with Discoid Lateral Meniscus : a Systematic Literature Review.

We assessed the prevalence of bilateral discoid lateral meniscus (BDLM), as well as its subtypes, among patients with symptomatic DLM. Medline, Cochrane, EMBASE, and Google Scholar were searched until September 18, 2015. All studies evaluating patients with BDLM who underwent MRI, macroscopic observation, and/or arthroscopy for the diagnosis of discoid meniscus/menisci were included. Eight clinical studies with a total of 583 DLM patients examined including 103 cadavers. There was a male predominance and average age of BDLM patients ranged from 10.4 to 39.9 years. The reported prevalence was higher in East Asian countries (72.7 to 97%) than rest of the world (6.8 to 90%). Homotypes were much more common than heterotype, and ranged from 82.9 to 91.7% of all BDLM patients. The actual prevalence of BDLM is likely higher. The findings provide a glimpse of the wide spread this disorder potentially has in East Asia.

Analysis of KIT mutations and c-KIT expression in Chinese Uyghur and Han patients with melanoma.

BACKGROUND: The KIT gene plays an important role in the pathogenesis of malignant melanoma (MM). In recent years, activating mutations in KIT have been recognized as oncogenic. A number of therapies have been established, which provide significant clinical benefits for patients with MM with KIT mutations. Thus, detection of KIT mutations can have profound therapeutic implications. AIM: To investigate KIT gene expression in MMs in Chinese Uyghur and Han patients with mutations in KIT, and to identify the clinical features associated with KIT mutations and c-KIT expression. METHODS: In total, 105 MMs (56 from Uyghur and 49 from Han patients) were selected from patients in the Uyghur Autonomous region. Formalin-fixed, paraffin wax-embedded tumour sections were analysed for c-KIT expression using immunohistochemistry. Exons 11 and 13 of KIT were analysed for the presence of mutations using PCR amplification and DNA sequencing. RESULTS: Of the 105 MMs, 13 (10 Han and 3 Uyghur) were found to have mutations in KIT. Thus, the frequency of KIT mutations in Han patients was significantly higher than that in Uyghur patients (P = 0.02). We detected c-KIT expression in 71.4% and 42.9% of the tumour tissue samples collected from the Uyghur and Han patients, respectively. CONCLUSION: In the Xinjiang Uyghur Autonomous Region in China, chronic sun-induced damage MM is the most prevalent MM among Chinese Uyghur patients, whereas acral and mucosal MMs are the most prevalent in Uyghur patients. Mutations in the KIT gene do not correlate with c-KIT expression.

Inhibition effect produced by dominant negative mutant fusion protein PreS2-TLM-ScFv-HBcDN on HBV replication in vitro.

A mammalian expression vector comprised of the PreS2-TLM (translocation motif), a single-chain variable fragment (ScFv) that binds to hepatitis B surface antigen (HBsAg) and the EGFP gene was constructed. A stably transformed cell line that could express and secrete the fusion protein (PreS2-TLM-ScFv-EGFP) was established. HBsAg-positive HepG2.2.15 cells and HepG2 and HeLa cells were incubated with the supernatant of the transformed cell line cultures for evaluating the cellular permeability of PreS2-TLM-ScFv-EGFP. The location of the fusion protein PreS2-TLM-ScFv-EGFP in HepG2.2.15 cells was observed with immunofluorescence staining. EGFP was next replaced by a dominant negative mutant of the hepatitis B virus core gene (HBcDN) for producing fusion protein PreS2-TLM-ScFv-HBcDN, which was detected by western blot. The supernatant containing fusion protein PreS2-TLM-ScFv-HBcDN was added to the cultures of HepG2.2.15 cells, and the packaged hepatitis B virus (HBV) pregenomic RNA expression levels in the cells were measured using qRT-PCR. The results of the in vitro study indicated that the packaged HBV pregenomic RNA expression levels in HepG2.2.15 cells significantly decreased when these cells were exposed to the supernatant at the dose of 25% for 24, 48 and 72 h, or at the dose of 12.5% for 72 h.

Analysis of prognosis-related factors in patients with invasive cervical adenocarcinoma.

OBJECTIVE: To explore the prognostic related factors in patients with cervical adenocarcinoma. METHODS: Clinical and pathological data were retrospectively analyzed in 144 patients with cervical adenocarcinoma between 1995 and 2004. RESULTS: Five-year survival rates were 80.1%, 59.7%, 6.3 % and 0.0%, respectively, in patients with Stage I, II, III and IV cervical adenocarcinoma, and the overall 5-year survival rate was 59.0%. Univariate analysis indicated poor prognosis in non-exophytic tumor, tumor diameter > 4 cm, advanced clinical stage, mucinous adenocarcinoma and clear cell carcinoma, or poorly differentiated tumor. The prognosis was related to lymph node metastasis and deep myometrial invasion. Multivariate analysis indicated that besides clinical stage, myometrial invasion and lymph node metastasis, tumor shape was also an independent prognostic related factor. CONCLUSION: The prognosis is associated with tumor shape besides pre-confirmed clinical stage, myometrial invasion and lymph node metastasis. Ovarian preservation in young women remains to be further explored.

Accumulation and distribution of polycyclic aromatic hydrocarbons in rice (Oryza sativa).

Various tissues of rice plants were sampled from a PAH contaminated site in Tianjin, China at different growth stages of the ripening period and analyzed for PAHs. PAHs were much higher in roots than in the exposed tissues. Grains and internodes accumulated much smaller amounts of PAHs than leaves, hulls or ear axes. No specific gradient trends along roots, stem, ear axes, and grains were observed, suggesting that systematic translocation among them is unlikely. Over the ripening period, PAH concentrations were increased in rice roots and decreased in most above-ground tissues. Significant correlations between PAH and lipid contents can only be observed during full mature stage. The spectra of individual PAH compounds in rice organs including roots were similar to those in air, rather than those in soil. There was also a significant correlation between bioconcentration factor (BCF, plant over air) and octanol/air partitioning coefficient (Koa).

Human exposure and health risk of alpha-, beta-, gamma- and delta-hexachlorocyclohexane (HCHs) in Tianjin, China.

The dynamic exposures to HCHs of individuals born between the years 1913 and 1993 in Tianjin have been simulated by connecting a fugacity model (IV) with a multimedia exposure model. Ingestion is the most important pathway for human beings to take up HCHs, and concentrations in the human body correlate with body weight changes. Accumulations of HCHs were derived assuming that the degradation in human body behaved linearly. The health risk of exposure to HCHs was measured using cancer risk and loss of life expectancy (LLE), and LLE was modified from its original definition to incorporate a dynamic calculation that takes variances in exposure into account. Monte-Carlo simulations were run to analyze the uncertainties of the model.

Organochlorine pesticides in agricultural soil and vegetables from Tianjin, China.

Samples of eight types of vegetables, the rhizosphere soils, and bulk soils were collected from two sites (A and B) in Tianjin, China for the determination of hexachlorocyclohexane isomers (HCHs) and dichlorodiphenyltrichloroethane and metabolites (DDXs). The average concentrations of total HCHs and DDXs in the bulk soils were 3.6 and 80.1 ng/g for site A and 102 and 235 ng/g for site B, respectively. Relative accumulations of HCHs and DDXs in the rhizosphere soil from site A but not site B were demonstrated. The concentrations of total HCHs and DDXs in vegetable roots were 3.6-60 and 4.2-73 ng/g for site A and 15-152 and 7.1-136 ng/g for site B, respectively. Difference in bioaccumulation among various vegetables, especially between tuber and fibrous vegetables was significant. DDXs in spinach and cauliflower from site B and lindane (gamma-HCH) in cauliflower from both sites and violet from site B exceeded the maximum residual limits. Linear correlation of log-transformed HCHs and DDXs contents between the vegetable roots and the rhizosphere soils suggests the direct uptake of HCHs and DDXs.

Sample purification for analysis of organochlorine pesticides in sediment and fish muscle.

The methods of sample purification for determinations of organochlorine pesticides (OCPs) in sediment and fish muscle were investigated in this study. A two-step procedure with preliminary cleanup and florisil column fraction was adopted. The working conditions of florisil column were firstly optimized. As to preliminary cleanup, liquid-liquid extraction by mixture of dimethyl formamide (DMF) and hexane and sulphonation by concentrated sulfuric acid were applied respectively and compared for the studied samples. The results indicated that liquid-liquid distribution could effectively separate lipids from fish muscle extracts, while failed in elimination of chlorophyll extracted from the relicts of hydrophytes in the sediment sample. In view of the sample appearance and clarity of gas chromatogram, sulphonation was more suitable to purify the sediment sample, however, the recoveries of the spiked standards were poor. The use of eluting solvent with stronger polarity could improve the corresponding recoveries significantly. Due to complete loss of Dieldrin, Endrin, and Endrin aldehyde after sulphonation, this pretreatment was improper to the three components. Sulfur, as the particular disturbing element in sediment, could be removed sufficiently by addition of activated copper powder. The relevant detection limits of the selected methods for OCPs in the studied substrates were also provided.