Volume 93  ·   Issue 06  ·  2013

To explore the prevalence of central sleep apnea in different age groups of children with sleep apnea-hypopnea (SAH).

A total of 431 children with SAH diagnosed by overnight polysomnography atour Sleep Centerwere retrospectively studied.Theywere divided into3 groups based on their ages: toddler group (1-<3 years old), preschool group (3-<6 years old) and school group (6-<13 years old).The relationship between age and different types of apnea-hyponea index (AHI) was analyzed.And the prevalence of central sleep apnea and sleep structurewere compared between the groups.

A negative correlation existed between age and central sleep apnea index (r=-0.322, P<0.01).However, therewas no correlation between age and obstructive apnea index (P>0.05).AHIwas similar in different age groups, but the medians of central sleep apnea index for toddler, preschool and school groupswere 2.35, 1.50 and 0.90 events/h respectively (all P<0.01).Sleep structure was similar between the groups (P>0.05).

Central sleep apnea is common in children with sleep disordered breathing.The younger their ages, a higher prevalence of central sleep apnea.

To validate the values of monitoring airflow, oxygen saturation and respiratory effort in the diagnosis of sleep apnea-hypopnea syndrome (SAHS).

A total of 70 subjects with suspected SAHS underwent the tests of polysomnography (PSG) and portable monitoring device (PMD) separately at our sleep lab.The portable monitoring device recorded nasal airflow, oxygen saturation and respiratory effort.Apnea-hypopnea index (AHI) or respiratory disturbed index (RDI), lowest oxygen saturation (LSaO₂), oxygen desaturation index (ODI₄) and percentage of different types of sleep breathing events (central/obstructive/mixed hypopnea) accounting for the total numbers of sleep disordered breathing were also analyzed.The data of AHI and ODI₄ showed skew distribution undergoing log transformation to approximate to normal distribution.Pair t test was used for the comparisons of different parameters.The agreement between two methods was analyzed by Bland-Altman plot.

Fifty-eight subjects were diagnosed as SAHS with an AHI (RDI) over 5 on PSG.The sensitivity and specificity of portable monitoring device were 94.8% and 75.0% respectively.The mean AHI derived from PSG and RDI derived from PMD were (27±25) and (29±27) times per hour respectively and those after log transformation were (1.2±0.5) and (1.2±0.5) times per hour (P=0.411).The mean ODI₄ derived from PSG and PMD were (23±25) and (21±24) and those after log transformation (0.9±0.7) and (1.1±0.5) times per hour respectively (P=0.042).The mean values of LSaO2 were 79%±13% and 79%±12% respectively (P=0.550).No significant differences existed between AHI derived from PSG and RDI derived from PMD.Bland-Altman plot also showed a high agreement between AHI derived from PSG and RDI derived from PMD.PMD could also identify major part of different events so as to aid clinical decision-making.

Portable monitoring device recording airflow, oxygen saturation and respiratory effort shows a great agreement with PSG with regards to AHI (RDI) and the identification of different types of respiratory events.

To explore the effects of neural respiratory drive on ventilation in patients with chronic obstructive pulmonary disease (COPD) during sleep.

Diaphragm electromyogram (EMG) from a multipair esophageal electrodes and airflow derived from pneumotachgraphy were recorded during overnight polysomnography in 13 patients with stable COPD recruited from outpatient clinic of First Affiliated Hospital of Guangzhou Medical College from May 2010 to May 2011.Changes in diaphragm EMG and ventilation during wakefulness and different sleep stages were observed.

Diaphragm EMG decreased by 26% in non-rapid eye movement sleep (NREM) stage and 39% in rapid eye movement (REM) as compared with wakefulness.Coinciding with change in diaphragm EMG, ventilation (VE)(ml·min^-1·kg^-1) significantly decreased from wakefulness (156±53) ml·min^-1·kg^-1to steady NREM stage (112±35) ml·min^-1·kg^-1 (P<0.05) and further decreased from NREM stage to REM stage (95±27) ml·min^-1·kg^-1 (P<0.05).Oxygen saturation also decreased significantly from 97.1%±1.8% in wakefulness to REM stage (94.0%±3.9%)(P<0.01).

Reduced neural respiratory drive contributes to nocturnal hypoventilation in COPD patients.

To explore the impact of chronic intermittent hypoxia (CIH) upon rat liver lipid metabolism and effect of anti-oxidant Tempol.

Male Wistar rats (n=80) were randomly divided into intermittent hypoxia group (10, 20, 30, 40 times/h), intermittent hypoxia Tempol treatment group, intermittent hypoxia normal saline treatment group, intermittent air mimic group (IA) and blank control group (CG).Sections of liver were stained with hematoxylin and eosin.Serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured.Levels of liver homogenate triglyceride (TG), total cholesterol (TC), free fatty acids (FFA) and serum TG, TC, adiponectin (ADP) were measured.

Liver histology: IH group exhibited hepatocellular swelling, hyperchromatosis, disrupted hepatocellular membrane.With the increase of frequency, there were local necrosis and infiltration of inflammatory cells.But no steatosis was seen.Tempol early treatment and IA groups exhibited no hepatocellular swelling or inflammatory cell infiltration.The activities of ALT and AST increased along with the increased frequency in IH group (all P<0.01).The levels of ALT and AST in IH group ((48.6±3.6), (25.4±2.6) U/L) were higher than those in IA group ((20.3±3.1), (18.7±1.3) U/L) and CG group ((17.5±2.4), (18.8±1.3) U/L)(all P<0.01).It decreased in Tempol treatment group,and more obviously when early intervention was applied (all P<0.01).Liver homogenate TG, TC and FFA had no difference among IH, IA and CG groups (all P>0.05), and no difference in different frequencies in IH group (all P>0.05).The levels of serum TG, TC in IH groups were higher than those in IA and CG groups while ADP was lower (all P<0.01).It changed more obviously in different frequencies in IH group (all P<0.01).In Tempol treatment group, serum TG, TC decreased while ADP increased and changed more obviously when early intervention was applied (all P<0.01).

CIH causes the morphologic changes of liver and the elevations of ALT and AST, but results not in lipid deposition in liver cells.Anti-oxidation of Tempol can block intermittent hypoxia associated with liver injury.

To observe the occurrence characteristics, dynamic variations and potential risks of smaller gastrointestinal submucosal tumor (SMT) in elderly patients.

A total of 54 SMT patients were retrospectively recruited from January 1981 to September 2010.There were 51 males (94.4%) and 3 females (5.6%) with an average age of (74±1) years.During each visit, all the relevant data were collected, including symptoms, number of lesion, lesion location, shape, size (maximum transverse diameter under endoscope or endoscopic ultrasonography (EUS), morphology of mucosa, frequency and duration of follow-ups, treatment and pathological results.And the data were analyzed to examine the characteristics of SMT in elderly patients and their dynamic variations.Further more,according to lesion diameter, they were divided into two groups:a diameter≤1 cm (n=36) and a diameter>1 cm and≤3 cm (n=16).Then the change of two groups were observed and compared during the follow-ups.

Two cases were not under surveillance after direct surgical resection.The other 52 patients received a follow-up of 22 years.Among them, 5 patients underwent surgical resection for fast-growing tumor and mucosal ulcer.And all their pathologic diagnoses were malignant.Only 1 patient (2.8%) in the diameter≤1 cm group and 4 in the diameter>1 cm and≤3 cm group turned malignant at 6 years.But, among 4 patients, the shortest interval was merely 14 months.Therefore, compared with the diameter>1 cm group, the diameter≤1 cm group had a lower rate of malignancy (P<0.05).

The incidence of smaller SMT (especially diameter≤1 cm) is high in elderly patients, but the malignant potential remains low.Therefore, for elderly patients whose diameters of SMT are no bigger than 3 cm and without obvious malignancy under endoscope or EUS, we may plan an appropriate surveillance interval based on the size of tumor during a long follow-up period.

To explore the clinicopathologic findings, endoscopic features and preoperative diagnostic rates of synchronous multi-primary esophageal carcinomas.

A total of 602 inpatients were diagnosed as esophageal carcinomas from January 1990 to April 2012.According to Warren′s criteria, 20 cases of synchronous multi-primary esophageal carcinomas were enrolled.There were 13 males and 7 females with a mean age of (62±11) years at the onset of diagnosis.Clinicopathologic features and diagnostic methods were studied retrospectively.

There were a total of 45 synchronous multi-primary esophageal carcinomas.Most lesions occurred in middle and lower thoracic esophagus (40 lesions, 88.9%) and were of fungating type (27 lesions,60.0%) under endoscopy.Histologically the most common type was squamous cell carcinoma (36 lesions, 80.0%).Eleven cases of upper gastroenterography (n=15) and 6 cases of endoscopy (n=11) were missdiagnosed respectively.

Because of a high rate of missed diagnosis, a clinician should be aware of multi-esophageal carcinomas.It is important to perform upper gastroenterography, abdominal computed tomography and endoscopy conscientiously to improve the diagnosis.

To explore the clinical manifestations, therapeutic response and RET gene mutation in a patient with multiple endocrine neoplasia 2B (MEN2B) characterized by medullary thyroid carcinoma (MTC), bilateral adrenal pheochromocytoma and multiple mucosal neuromas.

The clinical features, laboratory data and radiological manifestations of this patient were collected.Genomic DNA was extracted from her peripheral blood leukocytes and her parents.Tenth to sixteenth exons of RET proto-oncogene, including the flanking regions of introns, were amplified by polymerase chain reaction (PCR).And the mutations of RET proto-oncogene were identified by direct sequencing.

MEN-2B was diagnosed by the clinical presentations, laboratory tests and radiological findings.Gene analysis confirmed heterozygous mis-sense mutation at codon 918 in exon 16 of RET proto-oncogene in which thymine was replaced by cytosine (ATG→ACG).Her thyroid medullary carcinoma was treated by radical operations and radiotherapy.Tyrosinase inhibitor sorafenib was administered for 2 months and watery diarrhea and cough were alleviated.The drug was withdrawn because of such intolerant side effects as hair loss and painful rashes.She had a survival time of over 14 years with multiple system tumor metastases.

The mutation analysis of RET proto-oncogene confirmed the diagnosis of MEN2B in respect of molecular genetics.For patients with advanced MTC, tyrosinase inhibitors may relieve the symptoms and provide a new therapeutic choice.

To compare the operative techniques of single-incision laparoscopic cholecystectomy (SILC) via suture-suspension versus three-device method.

Retrospective analysis was performed for a total of 300 patients undergoing umbilical single-incision laparoscopic cholecystectomy from June 2008 to November 2011 at our hospital.The procedures were of suturesuspension (n=200) and three-device (n=100).Operative duration, estimated intra-operative blood loss, exposure extent of Calot′s triangle, postoperative pain score, hospital stay and complications were compared respectively between two groups.Both groups were matched for age, gender, body mass index (BMI), diagnoses and American Society of Anesthesiology (ASA) class.

All procedures were completed by the same surgeon.Comparison between two groups showed insignificant differences in blood loss (mean: (15.6±9.5) vs (16.8±7.4) ml;t=1.266,P=0.207),postoperative complications (number of case, incision contusion:4 vs 2, P=1.000;incision hemorrhage:2 vs 2, P=0.603) and hospitalization duration (mean: (1.6±0.5) vs (1.6±0.5) d;t=0.653, P=0.514), but significant differences in operative duration (mean: (40.5±16.0) vs (51.5±18.0) min; t=5.381, P=0.000), postoperative pain (mean:2.0±1.7 vs 3.7±1.6; t=8.324, P=0.000) and exposure of Calot′s triangle (number of case, 197 vs 68; χ²=60.178, P=0.000).Thus the suturesuspension method was superior to the three-device counterpart.

The suture-suspension method of SILC is safe, economic and easy-to-handle in clinical practice.

To explore the clinical characteristics, therapeutic and clinical significance for RET proto-oncogene screening in a pedigree with familial medullary thyriod carcinoma.

Comprehensivemedical history was obtained from 19 members in a 4-generate southern Chinese family.Systemic clinical investigations including biochemical testing, imaging examinations and germline RET screening.

RET screening showed heterozygousmissensemutations of TGC to TAC at codon 618 on exon 10 in 8 cases (p.C618Y) completely consistentwith the clinicalmanifestations.The clinical data of 7 patients with medullary thyriod carcinoma (MTC) and 2 carriers of asymptomatic RETmutation from were analyzed.Single/bilateral multi-centric MTC with lymph node metastases was confirmed in 6 cases by histopathology and 1 case by clinical examination.There were 1 male and 6 females with an initial mean diagnostic age was 49.6 years (range: 24-78).All had palpable neck masses.And themeanmaximum diameter of MTC was 2.6 cm (range 1.4-4.4).Seven patients underwent thyroidectomy except a 78-yearold female patient: right total and left subtotal thyroidectomy (n=1), right total thyroidectomy (previous left total thyroidectomy for benign mass)(n=1) and total thyroidectomy (n=4) were performed.All procedureswere accompanied by at least bilateral level Ⅵ lymph node dissection and/or with modified single/bilateral neck dissection.After the first operation, 6 patients still presented a high value of calcitonin: 1 patient died of metastasis 64 months postoperatively; 3 patients underwent reoperation at 6 months after initial operation, the calcitonin levels dropped to normal in 2/3 cases and stayed higher in 1 case; another two cases presented bilateral thyroid gland residua, local lymph node enlargement on imaging examination and elevated levels of calcitonin at 214 and 60 months postoperation respectively.However, 1/2 asymptomatic with elevated pre-operative calcitonin subjects underwent total thyroidectomy and histopathological examination showed bilateral C cell hyperplasia.The other carriers, without surgery, with normal neck images, close monitoring and a 10-month follow-up, still presented undetectable calcitonin.

Based on family survey, integrated RET screening and serum levels of calcitonin facilitate an early diagnosis and normalize surgery to improve the prognosis.For asymptomatic RETmutation carriers, their levels of calcitonin shall guide the individualized regimen of prophylactic thyroidectomy or strictmonitoring and follow-ups.

To explore the effects of lipoprotein(a)(Lp(a)) and fibrinogen (Fib) in senior patients with coronary heart disease (CHD) and examine the relationship of Lp (a) and Fib.

Based upon the results of coronary artery angiography (CAG), 784 subjects aged over 65 years were divided into control (n=116) group, one-vessel (n=106) group, two-vessel (n=120) and three-vessel (n=442) groups.And the levels of Lp(a) and Fib were measured.

(1) With increasing number of involved branches, the level of Lp (a) gradually rose in male group ((0.22±0.16), (0.28±0.23), (0.32±0.19), (0.34±0.21) g/L; F=9.22, P<0.01); (2) whether for males or females, with increasing number of involved branches, the levels of Fib gradually rose in male group ( (3.24±0.82), (3.41±0.82), (3.45±0.89), (3.61±0.90) g/L; F=3.09, P<0.05) and in female group ((3.58±0.97), (3.69±1.20), (3.77±0.88), (4.09±1.05) g/L; F=4.34, P<0.01); (3) the level of Lp(a) had a positive correlation with Fib in male group (r=0.15,P<0.01); (4) multi-Logistic regression analysis showed that Lp (a) and Fib were influencing factors of CHD (OR=0.31, 1.32, both P<0.05).

There are significant correlations between Lp (a), Fib and the severity of CHD in senior male patients.

To assess the diagnostic accuracy of coronary flow reserve measured by transthoracic Doppler echocardiography (TTDE) associated with adenosine triphosphate (ATP) stress for detecting coronary stenosis in patients with chest pain.

A total of 125 patients scheduled for elective coronary angiography (CAG) due to chest pain were recruited.ATP stress echocardiography were performed to measure CFR in left anterior descending (LAD) by TTDE with 2 days pre-CAG.Coronary flow reserve (CFR) was calculated as peak diastolic velocity during maximum hyperemia (PDV₂) divided by baseline (PDV₂).According to the coronary angiography results, all patients were divided into group A (stenosis<50% in LAD, n=57), group B (stenosis of 50%-75% in LAD, n=20) and group C (stenosis>75% in LAD,n=48).Then CFR was compared among three groups.The receiver operating characteristic curve (ROC) was used to assess the value of CFR for detecting LAD stenosis.

CFR was significantly different among three groups (group A: 3.02±0.85, group B: 2.49±0.65, group C:1.82±0.56; all P<0.01).With ROC analysis, CFR<2.2 was the best cut-off value for diagnosing significant LAD stenosis (area under curve: 0.86 (95% CI 0.80 to 0.93)), with sensitivity of 81%, specificity of 83% and accuracy of 82%; CFR<2.2 for diagnosing LAD stenosis>50% (area under curve: 0.81 (95% CI 0.74-0.89, P<0.01)), with a sensitivity of 59%, a specificity of 82% and an accuracy of 70%.

CFR measured by TTDE associated with ATP stress is a valuable tool for screening significant stenosis in patients with chest pain.Its advantages are non-invasiveness, easy availability, safety and inexpensiveness.

To summarize our experience of robotic internal thoracic artery (ITA) skeletonized harvesting in Asian patients and evaluate the learning curves of robotic ITA harvesting and ITA graft patency.

A total of 200 patients underwent totally robotic ITA takedown at our department from April 2007 to August 2012.ITA was harvested in a skeletonized fashion and learning curve estimated.Coronary artery bypass grafting was completed in minimally invasive direct coronary artery bypass graft (MIDCAB) or totally endoscopic coronary bypass graft on beating heart (BH-TECAB) manners after robotic ITA harvesting.The coronary angiography or 64-MSCT was performed to evaluate the patency of ITA graft before discharge and at Year 1-5 postoperatively.

One patient underwent median sternotomy for severe plural adhesion.Left ITA (LITA,n=190), right ITA (RITA,n=5) and double-ITA (n=4) were harvested.The mean duration of single ITA harvesting was 18-70 (35.8±10.7) min.A significant learning curve was observed: y (min) =58.0-5.3×ln(x)(r²=0.33, P<0.01).ITA patency was 98.1% at Year 1 and 97.8% at Year 2 postoperatively respectively.And there was no recurrence of ITA occlusion at Years 3-5.

Robotic ITA takedown is a prerequisite for totally endoscopic coronary bypass graft and can be performed safely and within an acceptable time after overcoming a learning curve.ITA graft patency has comparable outcomes of conventional surgery.

To observe the pathological effects induced by eosinophils (EOS) in the process of cellular damage in immune-related hematocytopenia (IRH) and elucidate the immunologic mechanism and clinical significance of EOS.

Enzyme-linked immunosorbent assay (ELISA) was performed to determine the serum concentrations of interleukins (IL)-2, IL-4, IL-5, IL-6, IL-12 and IL-17 in 117 IRH patients from February 2008 to February 2012 in our hospital.Their quantity, activity, peroxydase (POX) and HLA-DR expression of EOS were observed and analyzed.Immunofluorescent staining was used for detecting anti-human immunoglobulin (IgG) on the surface of hematopoietic cell and the expressions of intercellular adhesion molecule-1 (ICAM-1), FcγreceptorⅡ (FcγRⅡ), mannose receptor (MR), IL-5 receptor (IL-5R),IL-12,IL-12 receptor (IL-12R),IL-17A and IL-17A receptor (IL-17RA) on EOS.TdR incorporation method was employed to determine the capability of angtigen presentation and IL-17 mRNA expression examined by reverse transcriptionpolymerase chain reaction (RT-PCR).

The serum levels of IL-4, IL-5, IL-6, IL-12 and IL-17 were (170.9±14.7), (112.9±8.2), (131.8±13.8), (339.2±26.1) and (42.5±2.2) ng/L in patient group versus (60.3±11.0), (34.1±2.2), (91.0±12.3), (94.0±3.3) and (20.0±1.1) ng/L in control group respectively.All incremental percentages of IL-5, IL-12 and IL-17 were 100% (117/117) and they were correlated with disease.Diastrophic EOS could be found in marrow of patient with decreased leucocyte with HLA-B27⁺. Hematopoietic cells were adhered, captured and phagocytized actively by activated EOS.Activated EOS showed strongly positive POX while POX of neutrophils attacked by EOS became weakened.Activated EOS could express HLA-DR and played a role in antigen presentation.EOS could secrete cytokine IL-17 through a transcription of IL-17 mRNA.And EOS could also express ICAM-1, FcγRⅡ, MR, IL-5R and IL-12, IL-17 A, IL-17RA.

Capable of expressing or secreting various cytokines and molecules, EOS have immunological functions of adhering, capturing and phagocytizing pathological hemacytes.It also participates in pathogenic process of IRH.Thus EOSis probably an important immune effector cell in the process of in situ marrow damage.

To explore the effects of qishenyiqi gutta pills on myocardial hypertrophy of left ventricle and calcium/calmodulin dependent protein kinaseⅡ (CAMKⅡ) in rats with renal hypertension and elucidate its intervention mechanism for myocardial hypertrophy.

A total of 50 Wistar rats were randomly divided into 5 groups of sham-operation, control, high-dose qishenyiqi gutta pills, low-dose qishenyiqi gutta pills and valsartan (n=10 each).The rat model of myocardial hypertrophy with renal hypertension was established by the 2-kidney 1-clip (2K1C) method.The experimental animals were divided into control, high-dose, low-dose and valsartan groups.At Week 5 postoperation, valsartan group received an oral dose of valsartan (30 mg·kg^-1·d^-1), high-dose and low-dose groups took qishenyiqi gutta pills (250 and 125 mg·kg^-1·d^-1) while sham-operation and control groups had the same dose of normal saline solution.Tail arterial pressure was detected weekly and continued for 8 weeks.At the end of Week 12, the animals were sacrificed to harvest myocardial tissue of left ventricle for detecting left ventricular mass index (LVMI).The collagen volume fraction (CVF) of myocardium was examined by Van Gieson staining, the activities of superoxide dismutase (SOD) and reactive oxygen species (ROS) were detected by enzyme-linked immunosorbent assay (ELISA) and the expression of CAMK Ⅱ was detected by immunohistochemistry and Western blot.

(1) Blood pressures were significantly higher in high-dose, low-dose and control groups than thosein sham-operation and valsartan groups ((167.66±11.48), (166.72±13.51), (174.34±14.52) vs (119.57±6.30), (131.80±12.49) mm Hg, P<0.01).The changes of blood pressure had no significant difference between high-dose and low-dose groups. (2) LVMI and CVF increased significantly in high-dose, low-dose and valsartan groups versus sham-operation group (LVMI: (1.98±0.16), (2.09±0.14), (1.97±0.17) vs (1.74±0.17) g/kg; CVF:0.94%±0.22%, 2.53%±0.61%, 0.81%±0.20% vs 0.45%±0.13%)(P<0.01,P<0.05), but decreased significantly versus control group (LVMI: (1.98±0.16), (2.09±0.14), (1.97±0.17) vs (2.28±0.28) g/kg; CVF: 0.94%±0.22%, 2.53%±0.61%, 0.81%±0.20% vs 4.73%±1.04%)(P<0.01, P<0.05). (3) The expression of CAMK Ⅱ was significantly higher in high-dose, low-dose, valsartan and control groups than that in sham-operation group (65.9%, 95.3%, 84.8%,160.1% vs 67.7%).And it was significantly lower in high-dose, low-dose and valsartan groups than that in control group (65.9%, 95.3%, 84.8% vs 160.1%).There was no statistical difference among high-dose, low-dose and valsartan groups.

Qishenyiqi gutta pills may retard myocardial hypertrophy of left ventricle in rats with renal hypertension.And the mechanism is probably be correlated with its antioxidant activity and inhibited expression of myocardial CAMKⅡ.

To explore the anti-tumor effects of resveratrol (Res) upon human skin squamous cell carcinoma A431 xenograft in nude mice and elucidate the regulatory mechanisms of survivin and caspase-3.

The model of human skin squamous cell carcinoma (A431) xenograft in nude mice was established.And the animals were randomly divided into saline-negative control, cyclophosphamide (CTX) positive control, Res high-, medium- and low-dosage and blank control groups (n=10 each).After drug intervention, tumor-bearing mice were sacrificed.The tumor growth curve was plotted and the Res inhibition rate calculated by terminal tumor weight.The morphological changes of tumor cell among groups were observed by hematoxylin and eosin staining; cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling TUNEL; the impact of Res upon the protein expressions of survivin and caspase-3 in tumor issues was observed by Western blot.Analysis of variance and Pearson′s correlation were employed for statistical analyses.

(1) By the end of treatment, the tumor volume of CTX, Res high-, medium-, low-dosage, salinenegative control and blank control groups were (1154±255), (1002±115), (1207±176), (1342±211), (1642±226), (1564±156) mm³ respectively,and tumor weight of CTX, Res high-, medium-, low-dosage, saline-negative control and blank control groups (1.84±0.30), (1.72±0.39), (1.96±0.40), (2.67±0.73), (3.16±0.52), (3.33±0.59) g respectively.Through analysis of variance, the tumor volume and weight of Res high-, medium-, low-dosage groups were smaller than those of saline-negative control and blank control groups (all P<0.05).The inhibition rate of Res high-, medium- and low-dosage groups were 45.57%,37.97% and 15.51% respectively. (2) The apoptosis index of the above groups were 36.79%±8.86%,33.15%±6.00%,18.09%±3.92%,10.53%±4.20%,3.87%±1.63%,2.73%±1.61%.Through analysis of variance, the apoptosis index of Res groups were higher than those of saline-negative control and blank control groups (all P<0.05). (3) The protein expression of survivin/β-actin of each group were 0.48±0.20,0.19±0.11,0.22±0.12, 0.28±0.24, 0.98±0.41, 0.85±0.34.The protein expression of caspase-3/β-actin of each group were 0.42±0.09, 0.31±0.10, 0.31±0.07, 0.22±0.08, 0.14±0.04, 0.13±0.05 respectively.Through analysis of variance,the protein expression of survivin of Res groups was lower than those of the saline-negative control and blank control groups (all P<0.05).And the protein expression of caspase-3 of Res groups were higher than those of the saline-negative control and blank control group (all P<0.05).Through Pearson′s analysis, the protein expression of survivin and caspase-3 had no correlation (r=-0.279,P>0.05).

Res inhibits the growth of human skin squamous cell carcinoma A431 xenograft in nude mice.And its mechanism may be associated with the apoptosis of tumor cell through the depression of survivin and the activation of caspase-3.

To explore the effects of methane on proximal colon motility and elucidate its ion channel mechanisms.

The circular muscle and longitudinal muscle strips of proximal colon were isolated from rats.An isometric force transducer and a biology signal collection system were employed to observe the effects of methane on spontaneous contractile activity of muscle strips.The effects of methane on longitudinal muscle strips were observed after pre-treatment of these strips with tetrodotoxin (TTX) or N-nitro-L-arginine methylester (L-NAME).Single cell of colonic smooth muscle was isolated by collagenase and then whole-cell patch clamp technique was used to record voltage dependent potassium current (IK_V) and large conductance Ca²⁺-activated K⁺ current (IBK_ca) in the absence or presence of methane.

Methane significantly attenuated the contractile amplitude of longitudinal muscle strips (from (1.12±0.27) to (0.99±0.31) g, n=19, P=0.013) whereas there were no changes in some longitudinal muscle strips (n=6) in the presence of methane.The inhibitory effect of methane persisted after the pre-treatment of longitudinal muscle strips with TTX or L-NAME.Methane had no effects on the contractile cycle time of longitudinal muscle strips and contractile activity of circular muscle strips.And 3% methane solution significantly increased the density of IK_V (from (13.3±1.0) pA/pF to (18.5±1.4) pA/pF, at +60 mV, n=11, P=0.001) versus the control group whereas methane had no effect on IBK_ca (all P>0.05).

Methane can inhibit contractile activity of proximal colonic longitudinal muscle by activating voltage dependent potassium channel and increasing IK _V.