[Application value of questionnaires in the screening obstructive sleep apnea syndrome in pregnancy across trimesters]

Objective: To evaluate the clinical utility value of questionnaires of Berlin, STOP, STOP-Bang (SBQ), Epworth Sleepiness Scale (ESS) in screening obstructive sleep apnea syndrome (OSAS) in pregnant women of different trimesters. Methods: Consecutive pregnant women at high risk for OSAS were enrolled from January, 2021 to April, 2022 at the obstetric clinic of Peking University People's Hospital. They completed questionnaires of Berlin, STOP, SBQ, ESS and also underwent an overnight polysomnography (PSG). To evaluate the accuracy of questionnaires of Berlin, STOP, SBQ, ESS, sensitivity, specificity, positive predictive values, negative predictive values and the area under the receiver operating characteristics (ROC) curve of these questionnaires in pregnancy across trimesters (Pregnancy 1-15 weeks was the first stage, pregnancy 16-27 weeks was the second stage, and pregnancy 28-40 weeks was the third stage) were calculated. Results: A total of 100 pregnant women [(34.5±4.3) years old (26-46 years old)] were included in this study, including 20, 35 and 45 pregnant women in the first, second and third trimester of pregnancy, respectively. Based on PSG results, 45 (45%) of 100 pregnant women were diagnosed with OSAS. The overall predictive values of the four questionnaires were not good, area under[AUC(95%CI)] the ROC curve ESS, Berlin questionnaire STOP and SBQ were 0.54(0.43, 0.66), 0.59 (0.47, 0.70), 0.62(0.51, 0.73) and 0.61 (0.49, 0.72), respectively, sensitivity was 35.6%, 65.9%, 48.9%, 28.9%, specificity was 71.7%, 52.5%, 73.6%, 92.5%. When categorized according to trimesters, the predicted values of the four questionnaires increased in the first trimester, the AUC (95%CI) of STOP questionnaire was 0.81 (0.61, 1.00), sensitivity was 75.0%, specificity was 87.5%. Conclusion: The overall predictive power of the four screening questionnaires is limited in pregnant women. But predictive value of STOP questionnaire is acceptable in the first trimester.

[Attention should be paid to sleep disorders in critically ill patients and its recognition and intervention]

The sleep deficiency and sleep disturbance of critically ill patients may result in adverse outcomes, negative effects on early rehabilitation, and may persist well beyond the intensive care unit (ICU). It has been paid more and more attention in clinical practice. The sleep problems of critically ill patients are associated with suffered critical illness, ICU environments, and coexisting sleep disorders before critical illness. Poor sleep quality, insufficient sleep duration, severe sleep fragmentation and irregular circadian rhythms during critical care illness have been extensively described. In addition, ICU patients have been specifically shown to experience atypical sleep and pathologic wakefulness. So the sleep in critical ill patients should be evaluated. Sleep can be evaluated by both subjective assessment and objective measurements, including polysomnography and actigraphy. According to individual situation, comprehensive, interdisciplinary, and personalized interventions, which include treating critical illness, improving ICU environment to reduce interference to sleep, nonpharmacological treatment to relax and stabilize sleep, and treating coexisting sleep disorders, should be taken to improve the patient's sleep and then to promote the early rehabilitation of critically ill patients.

[Relationships between hypertensive disorders in pregnancy and obstructive sleep apnea syndrome]

Objective: To investigate the impact of obstructive sleep apnea syndrome (OSAS) on pregnancy outcomes, especially the relationship between OSAS and hypertensive disorders in pregnancy (HDP). Methods: A total of 228 pregnant women with high risk of OSAS who underwent sleep monitoring during pregnancy in Peking University People's Hospital from January 2021 to April 2022 were collected by reviewing their medical records for retrospective analysis. According to the diagnosis of OSAS, the pregnant women were divided into OSAS group (105 cases) and non-OSAS group (123 cases). The non-parametric Mann-Whitney U test, χ2 test or Fisher's exact test were used to compare the general data and maternal and fetal outcomes between the two groups, and the occurrence of each type of HDP was further compared. Results: (1) Compared with the non-OSAS group, the median pre-pregnancy body mass index (23.6 vs 27.6 kg/m2) and the proportion of snoring [28.9% (33/114) vs 59.2% (61/103)] in the OSAS group were higher, and the differences were both statistically significant (both P<0.001). (2) The incidence of HDP [67.6% (71/105) vs 39.0% (48/123)] and gestational diabetes mellitus [GDM; 40.0% (42/105) vs 26.8% (33/123)] of pregnant women in the OSAS group were higher than those in the non-OSAS group, and the median delivery week was shorter than that in the non-OSAS group (38.4 vs 39.0 weeks). The differences were all statistically significant (all P<0.05). Between-group differences for the delivery way, postpartum hemorrhage, the rate of intensive care unit admission, preterm birth, small for gestational age infants, neonatal asphyxia, the rate of neonatal intensive care unit admission, newborn birth weight and the proportion of umbilical artery blood pH<7.00 were not statistically significant (all P>0.05). (3) Compared with the non-OSAS group, the incidence of chronic hypertension [11.4% (14/123) vs 22.9% (24/105)] and chronic hypertension with superimposed pre-eclampsia [11.4% (14/123) vs 30.5% (32/105)] were higher in the OSAS group, and the differences were both statistically significant (both P<0.01). Conclusion: OSAS is related to HDP (especially chronic hypertension and chronic hypertension with superimposed pre-eclampsia) and GDM, which could provide a practical basis for the screening, diagnosis and treatment of OSAS in pregnant women at high risk.

Efficacy of image-enhanced endoscopy for colorectal adenoma detection: A multicenter, randomized trial

BACKGROUND

Improved adenoma detection at colonoscopy has decreased the risk of developing colorectal cancer. However, whether image-enhanced endoscopy (IEE) further improves the adenoma detection rate (ADR) is controversial.

AIM

To compare IEE with white-light imaging (WLI) endoscopy for the detection and identification of colorectal adenoma.

METHODS

This was a multicenter, randomized, controlled trial. Participants were enrolled between September 2019 to April 2021 from 4 hospital in China. Patients were randomly assigned to an IEE group with WLI on entry and IEE on withdrawal (n = 2113) or a WLI group with WLI on both entry and withdrawal (n = 2098). The primary outcome was the ADR. The secondary endpoints were the polyp detection rate (PDR), adenomas per colonoscopy, adenomas per positive colonoscopy, and factors related to adenoma detection.

RESULTS

A total of 4211 patients (966 adenomas) were included in the analysis (mean age, 56.7 years, 47.1% male). There were 2113 patients (508 adenomas) in the IEE group and 2098 patients (458 adenomas) in the WLI group. The ADR in two group were not significantly different [24.0% vs 21.8%, 1.10, 95% confidence interval (CI): 0.99-1.23, P = 0.09]. The PDR was higher with IEE group (41.7%) than with WLI group (36.1%, 1.16, 95%CI: 1.07-1.25, P = 0.01). Differences in mean withdrawal time (7.90 ± 3.42 min vs 7.85 ± 3.47 min, P = 0.30) and adenomas per colonoscopy (0.33 ± 0.68 vs 0.28 ± 0.62, P = 0.06) were not significant. Subgroup analysis found that with narrow-band imaging (NBI), between-group differences in the ADR, were not significant (23.7% vs 21.8%, 1.09, 95%CI: 0.97-1.22, P = 0.15), but were greater with linked color imaging (30.9% vs 21.8%, 1.42, 95%CI: 1.04-1.93, P = 0.04). the second-generation NBI (2G-NBI) had an advantage of ADR than both WLI and the first-generation NBI (27.0% vs 21.8%, P = 0.01; 27.0% vs 21.2.0%, P = 0.01).

CONCLUSION

This prospective study confirmed that, among Chinese, IEE didn’t increase the ADR compared with WLI, but 2G-NBI increase the ADR.

[Exploration on teaching reform of cancer epidemiology course]

This study aims to explore optimized teaching mode of cancer epidemiology for undergraduates, and provide scientific ideas and basis for improving teaching quality. Non-randomized concurrent control study was used. Undergraduates, enrolled in 2018, from the department of preventive medicine in A and B medical universities were selected as research objects. Traditional teaching mode was used for cancer epidemiology course in A medical university, and innovative teaching mode named "one core, four dimensions" was adopted in B medical university. After the course, questionnaire method was used to investigate self-cognition of students, teaching satisfaction and class preparation time of teachers in B Medical University. The post-class test method was used to compare the students' grades of cancer epidemiology in the two universities. The results indicated that among the 58 students of B medical university, 94.83% (55/58) students were familiar with common types of epidemiological studies and 86.21% (50/58) mastered the evaluation indicators of screening research. Among the nine teaching faculties from B medical university, seven reported that the new teaching plan helped students to learn frontier knowledge of cancer epidemiology, and eight reported the new teaching model was conducive to the interaction between teachers and students. The text score of students in B medical university was 50.34±4.90, significantly higher than that in A medical university (46.21±4.91, t=5.20, P<0.001). The optimized teaching mode of cancer epidemiology is highly praised by students and teachers, which has the potential to improve students' grasp of cancer epidemiology, the ability to combine theory with practice, and the teaching effect of cancer epidemiology.

[Validation of a contact-free sleep apnea monitor in adults with obstructive sleep apnea]

Objective: To evaluate the diagnostic value of a contact-free sleep apnea monitor in Chinese adults with obstructive sleep apnea (OSA). Methods: One hundred and ninety-eight participants with snoring were recruited between July 2018 and May 2019 in Sleep Center of Peking University People's Hospital, using nocturnal polysomnography (PSG) and contact-free sleep apnea monitor simultaneously. We evaluated the difference between respiratory event index (REI) generated by contact-free sleep apnea monitor and PSG-Apnea-Hypopnea Index (AHI). We calculated the sensitivity and specificity of OSA diagnosis using the contact-free sleep apnea monitor by hypothesis testing for means, Pearson correlation coefficient and Bland-Altman plots. Then, we used the receiver operating characteristic (ROC) curve to find out the best cut-off of OSA diagnosis. Results: PSG-AHI and the REI of contact-free sleep apnea monitor showed no statistically significant difference [15.9 (4.7, 40.2) vs. 16.2 (6.1, 40.0), P=0.381], and they were significantly correlated (r=0.914, P<0.05), with mean difference of -0.06 (95%CI:-18.44, 18.31). The ROC curve showed that if REI ≥5 events/h was used as diagnostic criteria, the sensitivity and specificity of diagnosing OSA were 91.2% and 58.0%, respectively. The sensitivity and specificity of the contact-free sleep apnea monitor REI≥13.3 in diagnosing moderate and severe OSA were 90.1% and 71.1%, respectively. Conclusion: The REI obtained from the contact-free sleep apnea monitor showed a good agreement with the PSG-AHI, and therefore, the contact-free sleep apnea monitor can be used for the screening of patients with moderate and severe OSA.

[Feasibility study of telemedicine model for diagnosis and treatment of patients with obstructive sleep apnea hypopnea syndrome in China]

Objective: To explore the feasibility of applying telemedicine model in disease management for patients with obstructive sleep apnea hypopnea syndrome (OSAHS) in China. Methods: A total of 24 patients were enrolled with suspected OSAHS who were admitted to the Sleep Center of Peking University People's Hospital from October 2015 to September 2016. Patients were diagnosed by electronic questionnaire assessment and home sleep apnea monitoring (HSAT) and were treated with remote automatic positive airway pressure (APAP). After 1 week, 1 month and 3 months of treatment, the patients were followed up by video. The follow-up questionnaire was completed by the patients through an independent data management platform. The APAP treatment data and compliance data were obtained through a built-in digital card of the APAP device. Linear regression model was used to explore the factors related to patient compliance. One-way repeated-measure analysis of variance was used to compare the changes of APAP duration and apnea hypopnea index (AHI) among patients at different treatment time points. Paired t-test was used to compare the EPWORTH scale (ESS) scores before and after treatment. Results: A total of 22 patients were diagnosed with OSAHS, including 20 males (90.9%), aged (45.6±10.2) years and AHI before treatment was (46.9±20.4) times/h. A total of 20 OSAHS patients received APAP treatment, and the proportion of patients with good compliance after 1 week, 1 month and 3 months of treatment were 15/19, 10/19 and 8/18, respectively. The severity of sleepiness before treatment affected compliance. Each 1-point increase in ESS score was associated with a 6.16% (95%CI: 3.01%, 9.31%) increase in compliance. Age, body mass index and AHI before treatment had no effect on compliance (all P values>0.05). The AHI of the patients who had been treated for 1 week, 1 month and 3 months were (2.5±2.1), (2.2±1.6) and (1.9±1.0) times/h, respectively. (P=0.195). After 3 months of treatment, the ESS score was (7.0±3.3), lower than that before treatment (10.6±3.1) (P=0.079). Conclusion: Telemedicine mode of diagnosis and treatment of OSAHS patients has good therapeutic effect and patient compliance, which is practical and feasible.

[Utility of the type 3 portable monitor for the diagnosis of sleep disordered breathing in patients with stable heart failure]

Objective: To evaluate the utility of a type 3 portable monitor (PM) at home for the diagnosis of sleep disordered breathing (SDB) in patients with stable congestive heart failure (CHF). Methods: Seventy-six consecutive patients with CHF (61 males, 15 females, mean±standard deviation age (57.0±16.9) years) were enrolled from the sleep center of Peking university People's Hospital during January 2016 to January 2019, and underwent overnight, unattended home sleep apnea testing (HSAT) with a portable monitor followed by an overnight simultaneous polysomnogram (PSG) with in-laboratory portable monitor (in-lab PM) recording within one week. The consistency of apnea hypopnea index (AHI), obstructive sleep apnea index (OAI), central sleep apnea index (CAI) between HSAT and PSG as well as the in-lab PM and PSG were analyzed by Bland-Altman plot; the sensitivity and specificity of PM for the diagnosis of SDB in patients with CHF were evaluated. Results: The number of patients included in the final analysis were 65 in HSAT, 63 in in-lab PM and 65 in PSG. AHI [M(Q₁,Q₃)] was 26.1 (10.9,40.1) events/h by HSAT, 27.9 (11.3,43.2) events/h by in-lab PM, both were not different from AHI 29.0 (10.2,45.0) events/h by PSG (P>0.05). The AHI, OAI and CAI assessed by HSAT correlated significantly with those by PSG (r=0.892, 0.903, 0.831, P<0.05). Bland-Altman analysis of AHI, OAI, CAI by PSG versus HSAT showed a mean difference of 3.1 events/h, 0.8 events/h, 1.2 events/h; limits of consistency were -15.2 to 21.4 events/h, -9.7 to 11.3 events/h, -10.9 to 13.2 events/h, respectively. Based on a threshold of AHI ≥5 events/h, HSAT had 94.6% sensitivity, 75% specificity, compared to PSG. For detecting Cheyne-Stokes respiration (CSR), a sensitivity of 96.4%,a specificity of 97.2% were achieved, compared to PSG. Conclusion: Type 3 PM can be used to diagnose SDB in patients with CHF.

[Utility of the type 3 portable monitor for the diagnosis of patients with obstructive sleep apnea]

Objective: To evaluate the utility of a portable monitor at home for diagnosis of obstructive sleep apnea (OSA) in Chinese adults. Methods: Eighty nine patients suspected of OSA underwent overnight, unattended home sleep apnea testing (HSAT) with a portable monitor (Nox-T3, Nox Medical Inc. Iceland)followed by an in-laboratory polysomnogram (PSG) with simultaneous portable monitor (PM) recording within one week. PSG and PM recorder were scored according to recommended guidelines by independent technicians. The correlation between PSG apnea hypopnea index (AHI) and PM respiratory disturbance index (RDI) were evaluated. Results: Sleep testing showed RDI was (30.0±20.9) events/h on HSAT, and (33.4±22.4) events/h on in-laboratory PM recording. Apnea-hypopnea index (AHI) on PSG was (35.1±23.7) events/h. There was significantly statistical difference among the three group (P<0.001). Both RDI on HSAT and RDI on in-laboratory PM correlated significantly with AHI on PSG (r=0.877, P<0.001 and r=0.962, P<0.001, respectively). Bland-Altman analysis of AHI on PSG versus RDI on HSAT showed a mean difference of 4.4 events/h; limits of agreement was -17.6 to 26.5 events/h. Closer agreements were present when comparing the simultaneous recordings, with AHI on PSG versus RDI on in-laboratory PM showing a mean difference of 1.4 events/h, and limits of agreement was -11.3 to 14.2 events/h. Based on a threshold of AHI≥5 events/h, RDI on HSAT had 98.8% sensitivity, 40.0% specificity. Using an AHI ≥ 15 events/h, RDI on HSAT had 91.5% sensitivity, 76.5% specificity. Conclusion: Type 3 PM has a good diagnostic value for adult OSA patients and there is close agreement between the Type 3 portable monitor and PSG.

[Impaired hypoxic ventilatory response and related factors in Han and Uygur patients with obstructive sleep apnea-hypopnea syndrome]

Objective: To investigate the respiratory central hypoxia response and its related factors in Han and Uygur patients with obstructive sleep apnea hypopnea syndrome (OSAHS). Methods: One hundred and sixty six OSAHS patients were selected from Jan. 2016 to Dec. 2016 in Department of Respiratory and Critical Care Medicine, Kelamayi Central Hospital, including 69 cases of Han nationality and 97 cases of Uygur nationality. Seventy-three healthy subjects of Uygur nationality were enrolled as the control group. All of them under went sleep monitoring, nocturnal oxygen saturation (SaO(2)), pulmonary function and respiratory central hypoxia response. Results: The 3 groups were matched for age, gender, body mass index(BMI) and apnea-hypopnea index(AHI). The Uygur patients had a higher oxygen desaturation index (ODI4) [(30±22) per hour vs (18±17) per hour ] than Han patients of the same age and BMI. Compared to Han patients, Uygur patients had weaker hypoxic responsiveness [(-0.41±0.23) L·min(-1)·%(-1) vs (-0.36±0.22) L·min(-1)·%(-1,) P<0.05], and the difference still existed after adjusting for AHI [(-0.31±0.21) L·min(-1)·%(-1) vs (-0.41±0.22) L·min(-1)·%(-1,) P<0.05] in mild OSAHS, but this difference was not significant in severe OSAHS. Conclusions: The central hypoxic response in Uygur OSAHS patients was lower than that in Han OSAHS patients and normal controls.

[Predictive value of typical cataplexy+ DQB1*0602 positive to hypocretin-1 reduction in cerebrospinal fluid in patients with narcolepsy]

Objective: To discusses the predictive value of typical cataplexy+ HLA-DQB1*0602 positive to hypocretin-1 (HCRT-1) reduction in cerebrospinal fluid (CSF) in patients with narcolepsy. Methods: A total of 165 narcoleptic patients, who were diagnosed at the Sleep Center of Peking University People's Hospital and Peking University International Hospital from March 2003 to March 2017, were recruited. The CSF HCRT-1 level and DQB1*0602 were measured in all the subjects. The narcoleptic patients were divided into two groups: typical cataplexy+ DQB1*0602 positive were CH group, and others who were not typical cataplexy and DQB1*0602 positive simultaneously were NCH group. The HCRT-1 level in CSF was declared to have a serious reduction when HCRT-1≤110 ng/L. According to this standard, the CH group and NCH group were subdivided into sub-groups and the data was analyzed to investigate the predictive value of typical cataplexy+ HLA-DQB1*0602 positive to HCRT-1 reduction. Results: There were 142 patients in CH group, including 137 patients with HCRT-1 reduction and 5 patients without. There were 23 patients in NCH group, including 15 patients with HCRT-1 reduction and 8 patients without. The positive predictive value of typical cataplexy+ DQB1*0602 positive for the reduction of HCRT-1 in CSF was 96.5%. Typical cataplexy+ DQB1*0602 positive had a good consistency with the HCRT-1 reduction in CSF (χ(2)=26.7, P<0.001). Conclusion: Typical cataplexy+ DQB1*0602 positive has a good predictive value to the HCRT-1 reduction in CSF in patients with narcolepsy.

[Clinical presentation of Kleine-Levin syndrome]

Objective: To analyze the clinical features of Kleine-Levin syndrome (KLS) patients. Methods: Clinical data of 44 patients with KLS of the Sleep Center of Peking University People's Hospital from January 2002 to July 2013 were systematically reviewed. The predisposing factors and clinical presentations were summarized, and compared with the data from a Western KLS study with a large subjects number. Nocturnal polysomnography (PSG) and multiple sleep latency test (MSLT) were conducted during relapse and remission period, respectively. HLA-DQB1*0602 gene were screened and analyzed. Results: Among the 44 patients, 28(63.6%) were men and 16(36.4%) were women, with a mean age of (18.3±8.9) years old. Most patients developed the symptoms during adolescence. Infection or fever was the most common trigger for episode. The main clinical presentations were 44(100.0%) hypersomnia, 31(70.5%) forgetfulness, 26(59.1%) decreased appetites, 24(54.5%) juvenile behavior, 18(40.9%) depression, etc. Compared with the Western study, it showed that our patients had decreased instead of increased appetite. The PSG testing did not have remarkable findings. MSLT showed mean sleep latency was significantly shorter during relapse than during remission [(10.4±5.4) vs (15.3±3.4) min, P=0.009]. HLA-DQB1*0602 was positive in 12 of 40(30.0%) patients, which was similar to the data in the Chinese population. Conclusions: KLS has various clinical characteristics. The presentation of appetite may be different between Chinese and western KLS patients.

Effect of early fluid resuscitation on the lung in a rat model of lipopolysaccharide-induced septic shock

BACKGROUND

Many clinical trials have showed that early fluid resuscitation can improve the prognosis and reduce the mortality rate of patients with septic shock. However, some experiments suggest that abundant fluid may injure the lung and other tissues.

AIM

To evaluate the protective effect of early fluid resuscitation and simultaneous norepinephrine treatment on lung function by using the rat model of lipopolysaccharide (LPS)-induced septic shock.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into four groups: normal control group, septic shock control group, early fluid resuscitation treatment group, early fluid resuscitation and simultaneous norepinephrine treatment group. Blood gas, lactate, fluid volume, and dose of norepinephrine were recorded. Pathological change was observed by hematoxylin and eosin staining and transmission electron microscopy. The activities of hydroxyl radicals, MDA, SOD and MPO were detected by spectrophotometry. The expression of IL-6, IL-8, and TNF-alpha were determined with ELISA kits.

RESULTS

LPS could induce rats to suffer from acute lung injury in early stage of septic shock. Early fluid resuscitation could guarantee effective circulating blood volume and tissue perfusion pressure, improve microcirculatory derangements, increase oxygen partial pressure and oxygenation index, but have the tendency to aggravate pulmonary edema. Simultaneous norepinephrine treatment in early stage could decrease the fluid volume, alleviate the degree of pulmonary edema, reduce the expression level of pro-inflammatory mediators in the serum and BALF, and increase the oxygenation index.

CONCLUSIONS

Early fluid resuscitation and simultaneous norepinephrine treatment may be a superior alternative to protect lung injury secondary to septic shock.

One Alpha-hydroxycholecalciferol Improves Growth Performance, Tibia Quality, and Meat Color of Broilers Fed Calcium- and Phosphorus-Deficient Diets

An experiment was conducted to evaluate the effects of one alpha-hydroxycholecalciferol (1α-OH D₃) on growth performance, tibia quality, and skin and meat color in broilers fed calcium (Ca)- and phosphorus (P)-deficient corn-soybean meal diets. A total of 288 male Ross broilers, at 21 days of age, were randomly assigned to three treatments with eight cages per treatment. Three levels of 1α-OH D₃ (0, 5, and 10 μg/kg) were added to a basal diet (0.50% Ca, 0.13% non-phytate phosphorus (NPP), and 0.35% total phosphorus (tP)) without vitamin D₃. As a result of this study, the addition of 1α-OH D₃ increased body weight gain (p<0.001), feed intake (p = 0.007), feed efficiency (p<0.001), tibia weight (p = 0.002), length (p<0.001), breaking-strength (p = 0.012), ash (p<0.001), Ca (p<0.001), and P content (p = 0.004). Dietary 1α-OH D₃ enhanced breast meat yellowness (p = 0.015) and the length and weight of the small intestine of the broilers. Moreover, 1α-OH D₃ decreased serum Ca concentration (p = 0.074) and breast meat redness (p = 0.010). These results indicate that the 1α-OH D₃ improves growth, tibia quality, and meat color in broilers fed Ca- and P-deficient corn-soybean meal diets.

[Comparison of rDNA-ITS2 sequences and morphological characters of Anopheles kunmingensis and Anopheles langshanensis in China, with discussion on taxonomic status]

OBJECTIVE

To determine the taxonomic status of Anopheles kunmingensis (AK) and An. liangshanensis(AL) from China.

METHODS

Sequence differences of rDNA-ITS2 and main morphological characters variability between different sources of AK and AL were compared.

RESULTS

The level of rDNA-ITS2 sequence differences among eight samples was under 2.9%. The total occurrence rates of main morphological characters examined in the female mosquitoes with pale fringe spot on V5.2, white basal band (or spot) on hind tarsomere IV, and larvae with bifurcated head hair 2-C were 43%(9/21), 89%(17/19), 40(4/10) in AK, and 79%(34/43), 44%(17/39), 20%(4/20) in AL, respectively. These rates calculated from separate colonies fluctuated within a wide range and overlapped, suggesting that there was no definite, stable morphological difference between AK and AL.

CONCLUSION

The morphological and molecular variations between AK and AL were small and belong to intraspecific level. The AK and AL may be considered as the same species, and that the An. kunmingensis may be recognized as the synonym of An. liangshanensis.

[Extent of lymph node dissection in rectal carcinoma]

Basing on 170 specimens of advanced rectal cancers radically resected, metastatic rule and extent of lymph node dissection were studied in order to guide future surgical treatment. In 170 cases, 77 had lymph node metastases. The lymph node metastatic rate was 45.3% and metastatic degree was 8.9% (527/5 912). Metastasis of the rectal cancer, according to the lymphatic anatomy, can be divided into upward, lateral and downward drain. Because the rectal cancer at any site can lead to the upward metastasis, the upward lymph node dissection, up to the base of inferior mesenteric artery (the third line of lymph nodes), must be done in all rectal cases, otherwise, 10% of patients would have residual cancer. In view of the lateral metastasis occurring only in rectal cancers under the peritoneal reflection, for which lateral lymph node dissection is necessary or one eighth of patients would have residual lesion. Generally, no lateral lymph node dissection is needed in cancers above the peritoneal reflection. Pathologic factor influencing the lymphatic metastasis is the form of tumor growth, such as poorly differentiated and mucoid adenocarcinomas aggressively growing deeply and extensively resulting in a higher lymph node metastatic rate, for which lymph node dissection must be performed.