[Pulmonary artery stenosis after single lung transplantation: a case report and literature review].

Objective: To summarize and analyze the clinical features, treatment, and prognosis of pulmonary artery stenosis post-lung transplantation. Methods: A 62-year-old male patient was admitted to the hospital with a cough and chest tightness of over a year's duration, which had worsened in the last two months, leading to the diagnosis of idiopathic pulmonary fibrosis. The clinical data were observed and reviewed post-left allograft single lung transplantation. Literature searches were conducted using the keywords "lung transplantation" "stenosis, pulmonary artery" and "postoperative complications" in CNKI, Wanfang Medical Network, and PubMed databases up to December 2022. Results: On January 26, 2022, a left allograft single lung transplantation was performed under general anesthesia. Postoperatively, extracorporeal membrane oxygenation and mechanical ventilation were successfully weaned off at 22 hours and 2 days, respectively, with transfer from the intensive care unit 12 days after surgery. PaO2 and PaCO2 were 50 mmHg and 40 mmHg after deoxygenation. Both pulmonary CT angiography and ventilatory-perfusion imaging indicated stenosis of the left pulmonary anastomosis. Balloon dilation and pulmonary artery stenting were performed, with PaO2 and PaCO2 improving to 87 mmHg and 42 mmHg, respectively. The patient was discharged 102 days post-surgery, and was followed up for 1 year, with a good prognosis. Additionally, 36 related articles were retrieved, encompassing 69 cases with a median age of 53 years (38.5-59.0 years). Of these, 27.54% (19/69) were diagnosed with idiopathic pulmonary fibrosis, 46.38% (32/69) underwent single lung transplantation, with the primary clinical symptom being hypoxemia in 71.01% (49/69) cases. Left pulmonary artery anastomotic stenosis was observed in 43.48% (30/69), with 65.22% (45/69) being diagnosed in the late postoperative period. Interventional therapy was performed to 44.93% (31/69), with a mortality rate of 21.74% (15/69). Conclusions: The primary clinical manifestation of post-lung transplantation pulmonary artery stenosis is hypoxemia and can be diagnosed by pulmonary artery CT angiography, transesophageal echocardiography, and pulmonary angiography. Early diagnosis can significantly reduce mortality, and interventional therapy is an effective treatment for severe pulmonary artery stenosis post-lung transplantation.

[Study on the prognostic influencing factors of esophageal squamous cell carcinoma and the predictive value of inflammatory reaction indexes on its postoperative recurrence].

Objective: To explore the influence factors of poor prognosis of esophageal squamous cell carcinoma (ESCC) and the predictive value of inflammatory reaction indexes including neutrophils and lymphocytes ratio (NLR), platelet and lymphocyte ratio (PLR), monocyte and lymphocyte ratio (MLR) provision and differentiation degree, infiltration depth, lymph node metastasis number on the postoperative recurrence of ESCC. Methods: A total of 130 patients with ESCC who underwent radical resection from February 2017 to February 2019 in Nanyang Central Hospital were selected and divided into good prognosis group (66 cases) and poor prognosis group (64 cases) according to the prognostic effect. The clinical data and follow-up data were collected. Multivariate logistic regression analysis was used to determine the independent influencing factors of poor prognosis. Spearman correlation analysis was used to determine the correlation between preoperative NLR, PLR and MLR with the degree of differentiation, depth of invasion and number of lymph node metastases. Receiver operating characteristic (ROC) curve analysis was used to evaluate the efficacy of NLR, PLR and MLR in predicting poor prognosis of ESCC. Results: Univariate analysis showed that the degree of differentiation, the degree of invasion and the number of lymph node metastasis were related to the prognoses of patients with ESCC (P<0.05). Multivariate logistic regression analysis showed that the degree of differentiation, depth of invasion and number of lymph node metastases were independent influencing factors for poor prognosis of patients with ESCC, moderate differentiation (OR=2.603, 95% CI: 1.009-6.715) or low differentiation (OR=9.909, 95% CI: 3.097-31.706), infiltrating into fibrous membrane (OR=14.331, 95% CI: 1.333-154.104) or surrounding tissue (OR=23.368, 95% CI: 1.466-372.578), the number of lymph node metastases ≥ 3 (OR=9.225, 95% CI: 1.693-50.263) indicated poor prognosis. Spearman correlation analysis showed that NLR was negatively correlated with the degree of differentiation and the number of lymph node metastases (r=-0.281, P=0.001; r=-0.257, P=0.003), PLR was negatively correlated with the degree of differentiation, depth of invasion and number of lymph node metastasis (r=-0.250, P=0.004; r=0.197, P=0.025; r=-0.194, P=0.027), MLR was positively correlated with the degree of differentiation and the number of lymph node metastasis (r=0.248, P=0.004; r=0.196, P=0.025). ROC curve analysis showed that the areas under the curve of NLR, PLR and MLR in predicting poor prognosis of ESCC were 0.971, 0.925 and 0.834, respectively. The best cut-off value of NLR was 2.87. The sensitivity and specificity of NLR in predicting poor prognosis of ESCC were 90.6% and 87.9%, respectively. The optimal cut-off value of PLR was 141.75. The sensitivity and specificity for predicting poor prognosis of ESCC were 92.2% and 87.9%, respectively. The best cut-off value of MLR was 0.40. The sensitivity and specificity of MLR in predicting poor prognosis of esophageal squamous cell carcinoma were 54.7% and 100.0%, respectively. Conclusions: The degree of differentiation, the degree of invasion and the number of lymph node metastases are closely related to the poor prognosis of patients with esophageal squamous cell carcinoma. NLR, PLR and MLR can provide important information for predicting the poor prognosis of esophageal squamous cell carcinoma.

[Nomogram prediction model of cervical anastomotic leakage after esophageal cancer surgery].

Objective: To retrospectively analyze the risk factors of anastomotic leakage in the neck after esophageal cancer and establish a nomogram prediction model that can accurately predict the occurrence of anastomotic leakage in the neck of the patient. Methods: The study retrospectively analyzed 702 patients who underwent radical esophageal cancer surgery between January 2010 and May 2015 at Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. A multivariate logistic regression model was used to determine the risk factors for neck anastomotic leak, and a nomogram model was constructed, internal validation methods were used to evaluate and verify the predictive effectiveness of the nomogram. Results: There were 702 patients in the whole group, 492 in the training group and 210 in the validation group. The incidence of postoperative cervical anastomotic leak was 16.1% (79/492) in 492 patients with esophageal cancer in the training group. Multifactorial analysis revealed calcification of the descending aorta (OR=2.12, 95% CI: 1.14, 3.94, P=0.018), calcification of the celiac artery (OR=2.29, 95% CI: 1.13, 4.64, P=0.022), peripheral vascular disease (OR=5.50, 95% CI: 1.64, 18.40, P=0.006), postoperative ventilator-assisted breathing (OR=5.33, 95% CI: 1.83, 15.56, P=0.002), pleural effusion or septic chest (OR=3.08, 95% CI: 1.11, 8.55, P=0.031), incisional fat liquefaction and infection (OR=3.49, 95% CI: 1.68, 7.27, P=0.001) were independent risk factors for the development of cervical anastomotic leak after esophageal cancer surgery. The results of the nomogram prediction model showed that the consistency indices of the training and external validation groups were 0.73 and 0.74, respectively (P<0.001), suggesting that the prediction model has good predictive efficacy. Conclusion: The nomogram prediction model can intuitively predict the incidence of postoperative cervical anastomotic leakage in patients with high prediction accuracy, which can help provide a clinical basis for preventing cervical anastomotic leak and individualized treatment of patients.

[Lung transplantation for pulmonary alveolar proteinosis: a case report and literature review].

Objective: To observe the efficacy of lung transplantation for pulmonary alveolar proteinosis (PAP) patients and to improve the understanding of the therapy. Methods: The clinical data of a patient with autoimmune PAP treated with sequential homogenous bilateral lung transplantation were described and the literatures were reviewed. Results: This 55-year-old female patient was diagnosed with autoimmune PAP and had been treated with whole lung lavage for 19 times, but only achieved short-term symptomatic relief after each operation. Inhalation of granulocyte macrophage colony stimulating factor occurred allergic reactions. Lung transplantation was performed on February 15, 2022, and a significant improvement in oxygenation and clinical symptoms were observed. The patient remained stable during follow-up. Conclusion: Treatment with lung transplantation is safe and effective for end-stage patients with PAP in the early phase, but the long-term effect remains to be observed.

[Application of external diaphragm pacemaker combination with high-flow nasal cannula in offline patients with postoperative severe cerebral hemorrhage].

Objective: To investigate the offline clinical effect of external diaphragm pacemaker (EDP) combination with High-flow nasal cannula oxygen therapy in postoperative severe cerebral hemorrhage patients. Methods: A total of 123 severe postoperative severe cerebral hemorrhage patients with tracheotomy and mechanical ventilation (MV) were selected, who were admitted in NICU of PLA Rocket Force Characteristic Medical Center from October 2016 to December 2019. These patients were randomly divided into the High-flow nasal cannula (HFNC) group (n=63) and HFNC+EDP group (n=60). In the HFNC group, the HFNC was given to the patients who were off ventilator. The HFNC+EDP group was added on the basis of treatment in the HFNC group, once a day and 30 minutes each time. Results: Compared to the HFNC group, the oxygenation index (OI) of the HFNC+EDP group was higher in the next 1, 12, 24 and 48 hour [(209±15) mmHg vs (218±18) mmHg, (215±14) mmHg vs (222±17) mmHg, (223±13) mmHg vs (235±15) mmHg, (236±7) mmHg vs (257±12) mmHg,P<0.05]. The offline time was shorter [(13±3) d vs (12±3) d,P<0.05]. The excursion of diaphragm was higher [(1.94±0.08) cm vs (2.91±0.11) cm,P<0.05]. The length of stay in NICU was shorter [(33±14) d vs (28±9) d,P<0.05]. The Glasgow Coma Scale (GCS) was higher when being discharged from the NICU (5.9±2.1 vs 7.8±0.4, P<0.05) and the hospital (9.9±2.1 vs 11.0±2.0, P<0.05). Conclusions: EDP combination with HFNC can increase the excursion of diaphragm, shorten the offline time and length of stay in the NICU, thereby enhancing the early recovery and improving the prognosis.

[Risk factors of cervical anastomotic leakage after thoracoscopic-lapacoscopic esophagectomy in patients with esophageal carcinoma].

Objective: To analyze the risk factors of cervical anastomotic leakage after thoracoscopic-lapacoscopic esophagectomy. Methods: 530 patients with esophageal cancer underwent thoracoscopic-lapacoscopic esophagectomy at the Cancer Hospital, Chinese Academy of Medical Sciences from Jan 2011 to Dec 2015. The demographic, surgical and clinical data of patients were retrospectively analyzed. Multivariate logistic regression was used to evaluate risk factors of cervical anastomotic leakage in these patients. Results: A total of 530 patients undergoing thoracoscopic-lapacoscopic esophagectomy were enrolled in this study. There were 421 males and 109 females. The mean age was (59.40±8.08) years old, and 91 patients with cervical anastomotic leakage. Sigle factor analysis revealed that the risk grading by American Society of Aneshesiologists, previous history of chest surgery, respiratory comorbidity, diffusion capacity for carbon monoxide of the lung, operation time, anastomosis, average days of postoperative hospitalization, death within 30 days after surgery, respiratory complications, pleural effusion or empyema, and poor healing of the incision were statistically associated with cervical anastomotic leakage (all P<0.05). Multivariate analysis showed that previous history of chest surgery, hepatic insufficiency, manual anastomosis, prolonged postoperative hospitalization, and poor healing of the incision were independent risk factors for cervical anastomotic leakage after thoracoscopic-lapacoscopic esophagectomy (all P<0.05). Conclusions: Previous history of chest surgery, hepatic insufficiency, poor healing of the incision, manual anastomosis and prolonged postoperative hospitalization were significantly associated with cervical anastomotic leakage after thoracoscopic-lapacoscopic esophagectomy. It's important to strengthen perioperative nursing and surgical techniques to prevent anastomotic leakage after thoracoscopic-lapacoscopic esophagectomy.

[Analysis of the risk factors for postoperative cervical anastomotic leakage after McKeown's esophagectomy].

Objective: To analyze risk factors of anastomotic leakage after McKeown'sesophagectomy. Methods: The clinical data of 635 esophageal cancer patients, who underwent McKeown's esophagectomy at Cancer Hospital of Chinese Academy of Medical Sciences from January 2012 to December 2015, were retrospectively analyzed. The risk factors of cervical anastomotic leakage were identified through analysis of medical history, surgical procedure, tumor characteristics and vascular calcification. Results: Among all the 635 patients, anastomotic leakage occurred in 111 (17.5%)patients. Univariate analysis showed that the American Society of Anesthesiologists (ASA) risk class, prior thoracic surgery, upper digestive tract ulcer, COPD, hypertension, peripheral vascular disease, renal insufficiency, FEV1% predicted, DLCO% predicted, duration of surgery and calcification of descending aorta, celiac trunk and left postceliac arteries were associated with a statistically significant increase in risk of cervical anastomotic leakage (P<0.05 for all). Logistic regression analysis showed that ASA risk class, peripheral vascular disease, renal insufficiency and calcification of descending aorta and celiac trunk were independent risk factors of cervical anastomotic leakage after McKeown's esophagectomy (P<0.05 for all). Conclusions: ASA risk class, peripheral vascular disease, renal insufficiency, calcification of descending aorta and celiac trunk are independent risk factors of cervical esophageal anastomotic leakage after McKeown's esophagectomy.

[Changes of brain function and cognitive function after carotid artery stenting].

Objective: To investigate the effect of carotid artery stenting(CAS) on cognitive function and brain function based on changes of a battery of neuropsychological tests and magnetic resonance imaging. Methods: Thirty-three patients were included with 17 in the stent-placement group and 16 in the control group (receiving medical treatment), among whom, the unilateral or bilateral severe internal carotid artery stenosis was confirmed by cerebral vascular angiography in the department of Interventional Radiology and Vascular Surgery of Zhongda Hospital Southeast University from June 2015 to September 2016.Neuropsychological tests and rest-state blood oxygenation level dependent fMRI were performed at the baseline and six months follow-up.The baseline characteristics and follow-up changes were compared in each group. Results: The overall cognitive function of the stent-placement group was statistically significantly improved (P<0.05) compared with control group, mainly in the executive function, memory, attention and other aspects.The value of amplitude of low-frequency fluctuation(ALFF) showed statistically significant increase (P<0.05, Alphasim correction) in left prefrontal cortex (t=5.861 3, P<0.05), the somatosensory association cortex in left superior parietal lobe(t=5.601 2, P<0.05) and bilateral motor cortical area in posterior frontal lobe (t=5.288 5, P<0.05). The ALFF showed statistically significant decrease (P<0.05, Alphasim correction) in left retrosplenial cingulate cortex(t=-5.590 4, P<0.05), left insular cortex (t=-6.340 8, P<0.05), right insular cortex (t=-8.129 9, P<0.05) and left dorsal anterior cingulate cortex (t=-5.584 8, P<0.05). There was no statistically significant difference (P>0.05, Alphasim correction)between baseline and follow-up results in control group.Besides, the ALFF changes of the left insular cortex (r=-0.591, P=0.033) and bilateral motor cortical area (r=-0.659, P=0.014) were negatively correlated with auditory verb learning test (AVLT) score changes.The ALFF change of bilateral motor cortical area was negatively correlated with the AVLT-delay score change (r=-0.588, P=0.034). And the ALFF change on right insular cortex and the frontal assessment battery (FAB) score change was positively correlated (r=0.638, P=0.025). Conclusions: The overall cognitive function of patients with carotid artery stenosis significantly improve after CAS compared with medical treatment.The change of ALFF value in related brain area is also statistically significant.ALFF Change most in area of Default Mode Network may suggest a mechanism of postoperative neurological recovery in patients with carotid artery stenosis.

[Retrospective analysis of the discharge outcome of external ventricular drainage and conservative treatment in patients with severe intraventricular hemorrhage].

Objective: To investigate the discharge outcome of external ventricular drainage(EVD) and conservative treatment in patients with severe intraventricular hemorrhage (SeIVH). Methods: From January 2011 to December 2016, patients with SeIVH admitted to the General Hospital of the PLA Rocket Force and the Army General Hospital received EVD treatment and were classified as the treatment group. According to intraventricular hemorrhage volume and age, patients received conservative treatment were pair matched and classified as control group. Then we compared the clinical outcome of moderate disability or less degree of discharge (mRS ≤3) and death incidence (mRS 6) between two groups. Results: A total of 361 patients with IVH were treated during these six years. Among them, 75 cases were chosen as treatment group. Another 75 cases were pair matched as control group from 286 cases. At the time of admission, the ventricular hemorrhage volume of two groups were (55.8±22.7) ml and (53.7±23.3) ml (P=0.569) respectively. Cerebral hemorrhage volume were (23.6±5.3) ml and (24.0±5.4) ml (P=0.631). And the median Glasgow coma score (GCS) were 4[IQR(3, 7)] and 5[IQR(4, 7)](P=0.131). At the discharge time, there were 16% (12/75) patients scored mRS≤3 in treatment group, while 2.7% (2/75) in control group (P<0.005). The absolute risk reduction (ARR) was 13.3%, and the number needed to treat (NNT) was 7.5. The mortality rate of treatment group was 13.3% (10/75), much lower than that of the control group 41.1% (31/75, P<0.001). ARR was 27.8% and NNT was 3.6. Conclusion: Although the prognosis of SeIVH was poor, compared with conservative treatment, EVD treatment significantly improved the outcome of these patients. Randomized controlled trials are needed to validate the efficacy of EVD.

Compressive mechanical properties of bovine cortical bone under varied loading rates.

Bone tissue functions in varied mechanical systems of the body under static and dynamic conditions. Therefore, it is essential to understand the mechanical responses of bone at varied loading rates, especially those at fast loading rates. This study has investigated the effect of loading rate on the compressive mechanical properties of bovine cortical bone. Bone specimens of 3.85 mm in diameter and 7.7 mm in length were compressed longitudinally with the loading rates of 2 to 2000 mm/s (corresponding strain rates of 0.26 to 260 s(-1)). As a result, bovine cortical bone showed high linear elasticity when the loading rate was slow, and exhibited three definite regions of linear elasticity, plastic deformation, and densification at faster loading rates. The elastic modulus showed no dependency on the loading rate. Compressive strength, strain at fracture, and toughness increased as the loading rate increased under the condition that the loading rates were slower than each critical loading rate of 1000, 100, and 1500 mm/s, respectively. However, all showed no significant changes when the loading rates were faster than the corresponding critical loading rates. In conclusion, as the loading rate increased, changes in the compressive mechanical parameters were different depending on the parameter and the loading rate range. Compressive mechanical behaviour of bovine cortical bone showed a brittle nature under high strain rates (strain rates > 13 s(-1)). These findings should be reflected in the biomimetic simulation of biomaterials for bone tissue repair and engineering.

Highly expressed lncRNA FOXD3-AS1 promotes non-small cell lung cancer progression via regulating miR-127-3p/mediator complex subunit 28 axis.

OBJECTIVE: The present study aimed to determine the expression of long non-coding RNA (lncRNA) FOXD3 antisense RNA 1 (FOXD3-AS1) in lung cancer tissues and to explore its underlying mechanisms in mediating non-small cell lung cancer (NSCLC) progression. MATERIALS AND METHODS: Gene expression levels were determined by quantitative real-time PCR; lung cancer cell proliferation and invasion were determined by in vitro functional assays; protein levels were determined by Western blot assay; xenograft nude mice model was used to evaluate the in vivo tumor growth of lung cancer cells; Luciferase reporter assay determined the interactions among FOXD3-AS1, miR-127-3p, and mediator complex subunit 28 (MED28). RESULTS: Data mining and analysis of the clinical sample showed that FOXD3-AS1 expression was significantly up-regulated in lung cancer tissues. In vitro functional assays demonstrated that FOXD3-AS1 overexpression promoted NSCLC cell proliferation and invasion, while FOXD3-AS1 knockdown exerted tumor-suppressive effects on NSCLC cells. Moreover, FOXD3-AS1 interacted with miR-127-3p by acting as a competing endogenous RNA to suppress miR-127-3p expression, while miR-127-3p repressed MED28 expression by targeting MED28 3' untranslated region in NSCLC cells. Mechanistically, the oncogenic effects of FOXD3-AS1 overexpression were significantly attenuated by miR-127-3p overexpression and MED28 knockdown in NSCLC cells. In the xenograft mice model, FOXD3-AS1 knockdown suppressed in vivo tumor growth of A549 cells, and also up-regulated miR-127-3p expression and repressed MED28 expression in the xenograft tumors. In the clinical aspect, the downregulation of miR-127-3p and up-regulation of MED28 were respectively detected in lung cancer tissues. CONCLUSIONS: Our findings provided new evidence that the FOXD3-AS1 regulated NSCLC progression via targeting the miR-127-3p/MED28 axis.

MicroRNA-124 inhibits colorectal cancer cell proliferation and suppresses tumor growth by interacting with PLCB1 and regulating Wnt/ß-catenin signaling pathway.

OBJECTIVE: Colorectal cancer (CRC) is the most common malignancy for cancer-associated death. This study aimed to investigate the effects of microRNA-124 (miR-124) on tumor proliferation of CRC in vivo and in vitro. MATERIALS AND METHODS: MiR-124 mimics were synthesized and transfected into SW620 cells, which were divided into SW620, microRNA-normal control (miR-NC) and miR-124 mimics group. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to examine miR-124, chemokine (C-C motif) ligand-20 (CCL20), tankyrase-2 (TNKS2), phospholipase Cbeta1 (PLCB1) and Wnt4. Cell counting kit-8 (CCK-8) was employed to evaluate cell proliferation. The interaction between miR-124 and PLCB1 was tested with the Dual-Luciferase assay. Cell cycle, apoptosis and invasion were also evaluated. CRC xenograft mouse model was established and tumor size was measured. Hematoxylin and eosin (HE) was used to examine inflammation. Western blot was utilized to detect Wnt4. RESULTS: MiR-124 was over-expressed in SW620 cells, significantly reduced CCL20 and enhanced TNKS2 compared to that of the miR-NC group (p<0.05). MiR-124 might play roles by initiating PLCB1 expression. MiR-124 significantly decreased cell viability compared to the miR-NC group (p<0.05). MiR-124 regulated cell cycle and markedly induced apoptosis and inhibited cell invasion compared to the miR-NC group (p<0.05). MiR-124 significantly decreased tumor size of CRC models compared to miR-NC mice (p<0.05). MiR-124 remarkably alleviated inflammation of tumor tissues. MiR-124 markedly enhanced Wnt4 expression compared to the miR-NC group (p<0.05). CONCLUSIONS: MiR-124 inhibited tumor cell proliferation in vitro and suppressed tumor growth in vivo by interacting with PLCB1 and regulating the Wnt/ß-catenin signaling pathway.

[Clinical significance of the preoperative neutrophil lymphocyte ratio in the evaluation of the prognosis of laryngeal carcinoma].

OBJECTIVE: To explore the effect of preoperative neutrophil lymphocyte ratio (NLR) on the prognosis of patients with laryngeal carcinoma. METHODS: Clinical data of 202 patients with laryngeal carcinoma treated from January 2004 to October 2009 were retrospective analyzed to determine the optimal critical value of NLR. To study whether NLR is an independent factor affecting the recurrence and 5-year survival rate of patients with laryngeal cancer after surgery, single factor and multivariate analyses were performed. The factors included age, gender, T stage, pathological differentiation, lymph node metastasis, primary tumor site and NLR value. The relationship between NLR and cervical lymph node metastasis was analyzed. RESULTS: The optimal critical value of NLR was 2.85, by which cases were divided into high NLR group (NLR≥2.85) and low NLR group (NLR<2.85). Single factor and multivariate analyses indicated that T staging, lymph node metastasis, primary tumor location, and NLR were the independent factors affecting the recurrence of laryngeal carcinoma. T stage and lymph node metastasis were the independent factors affecting 5-year survival rate of laryngeal carcinoma. The increase of NLR value increased the rate of cervical lymph node metastasis. CONCLUSION: Preoperative NLR level influences the recurrence and cervical lymph node metastasis of laryngeal carcinoma and can be considered a prognosis factor of laryngeal cancer.

Pathohistogenetic approach on the etiology of Yunnan tin miner's lung cancer.

Pathological observation was made in 100 surgically resected lung cancers of Yunnan tin miners: peripheral type 44 including 9 scar cancers; central type 56, 27 of whom were early lung cancer, with limited initial loci in a well defined area. On the basis of dust retention in original sites of lung cancer and results of X-ray microanalysis, a scheme for calculating the relative probability of causation is formulated. The result of calculation shows that the contribution of exposure to radon daughters is about 7 times that of ore dust retention in the etiology of Yunnan tin miner's lung cancer.

[Genetic structure and intraspecific genetic polymorphisms in natural populations of Psathyrostachys huashanica].

Psathyrostachys huashanica Keng, which is endemic to China, only distributes in Mt. Hua of Shaanxi Province. 5 enzyme systems coding 13 loci were analyzed in 13 subpopulations of P. huashanica from Mt. Hua. Allozyme analysis showed that high genetic variability and clonal diversity existed in the species. Mean proportions of polymorphic loci (95% criterion), average number of alleles per locus, and mean expected heterozygosity were 69.2%, 1.8 and 0.344, respectively. Simpson index was 0.998. A negative species mean fixation indice (-0.252) indicates that there is a considerable excess of heterozygotes compared to the expected proportions of heterozygote loci. Mean genetic distance among populations was 0.049 (range: 0-0.139), and 91% of the genetic variation resided within populations. Gene flow estimated by indirect methods was 2.77, which was much lower than the Nm value (5.24) of anemophytes. This suggested that gene flow of P. huashanica might be in a critical level, and genetic differentiation might occur in natural population of this species.

[Measurement of the single muscle fiber action potentials and jitter value in tibialis anterior muscles of rabbits in situ].

With a home-made jitter data processing board and microcomputer for recording extracellular single fiber action potential (SF-AP), variations of the time intervals of the SF-AP pairs, or the jitters, from two adjacent muscle fibers in the unique motor unit in tibialis' anterior in response to repeated stimuli were measured. The jitter distribution of 936 recorded from 7 rabbits was positively showed with a percentile value of P75-P25 of 54.99-14.61 microseconds. The data suggested that the lower limit was smaller than that of skeletal muscles in normal human and that there exists also some differences in the jitter values of SFEMG between human and rabbit muscles.

[Effect of oxLDL on the uptake and clearance rate of cholesterol in vascular smooth muscle cells originated from human apoAI transgenic mice].

OBJECTIVE: Study on (1) inhibition of oxidized low density lipoprotein (oxLDL) effect on the uptake and clearance of intra-cellular 3H-cholesterol in vascular smooth muscle cells (v-SMC) originated from the human-apoAI transgenic mice (C57BL/6); (2) change of human-apolipoprotein AI (h-apoAI) mRNA expression in v-SMC after oxLDL stimulation and the protective effect of expressed h-apoAI on v-SMC against oxLDL intoxication. METHODS: (1) v-SMC isolated from human apoAI transgenic mice possessing a recombined gene connected beforehand with a mouse metallothionein-I (MT-I) as the promoter; (2) study of h-apoAI mRNA expression from v-SMC of the transgenic mice by RT-PCR and Northern blot. RESULTS: oxLDL (30 micrograms/ml) strongly promoted v-SMC proliferation. No difference found on 3H-cholesterol uptake between smooth muscle from normal mouse aorta (n-SMC) and smooth muscle cells from transgenic mouse aorta (tr-SMC) of the control groups, the uptake rates of both kinds of SMC rose 100% after oxLDL stimulation. The efflux rates of 3H-cholesterol in tr-SMC were much higher than those of n-SMC (40%-50%). After oxLDL stimulation, the clearance rates fell by 28% and 10% respectively for n-SMC and tr-SMC. The result of RT-PCR and Northern blot showed a marked increase of h-apoAI gene expression after oxLDL stimulation. CONCLUSIONS: Expression of h-apoAI gene in C57BL/6 mice enables to decrease the accumulation of cholesterol in v-SMC. tr-SMC are capable to alleviate the harmful effect of oxLDL on v-SMC due to the increase of h-apoAI expression.