[A preliminary study on the tear matrix metalloproteinase 9 point-of-care assay using a domestic kit]

Objective: To compare the point-of-care assays for tear matrix metalloproteinase 9 (MMP-9) using domestic and InflammaDry kits, and to evaluate the feasibility of diagnosing dry eye with the domestic kit. Methods: It was a cross-sectional study. Thirty dry eye patients and 30 age-and sex-matched normal volunteers were continuously enrolled in this cross-sectional study from June 2022 to July 2022. Both domestic and InflammaDry kits were used to detect the tear MMP-9 levels. The positive rates were recorded for qualitative analysis, and the gray ratios of bands (the gray value of detection bands to that of control bands) were collected for quantitative analysis. The correlations of MMP-9 levels with age, ocular surface disease index, fluorescence tear break-up time, tear meniscus height, Schirmer's Ⅰ test score, corneal fluorescein staining score, and meibomian gland dropout were analyzed. The Mann-Whitney U test, paired Chi-square test, Kappa test, and Spearman's correlation coefficient were used for statistical analysis. Results: There were 14 males and 16 females (30 eyes) in the control group, and their age was (39.37±19.55) years. In the dry eye group, 11 males and 19 females (30 eyes), aged (46.87±17.85) years, had moderate to severe dry eye. The positive rates of MMP-9 in tear fluid were significantly different between dry eye patients (InflammaDry: 86.67%; domestic kit: 70.00%) and controls (InflammaDry: 16.67%, P<0.001; domestic kit: 6.67%, P<0.001). Although the sensitivity of the domestic kit was lower than that of the InflammaDry kit (70.0% vs. 86.7%, P=0.001), the specificity was higher (93.3% vs. 83.3%, P=0.001). In dry eye patients, the positive coincidence rate was 80.7% (21/26), the negative coincidence rate was 100% (4/4), and the total coincidence rate was 83.3% (25/30), with no significant difference between the two kits (McNemar test: χ²=3.20, P>0.05), and the results of both kits were consistent (Kappa=0.53, P=0.001). The Spearman's correlation coefficient showed the gray ratios using both kits were positively correlated with the corneal fluorescein staining score (InflammaDry: ρ=0.48, P<0.05; domestic kit: ρ=0.52, P=0.003). Conclusion: The performances of the domestic and InflammaDry kits are consistent in the point-of-care assay for tear MMP-9, and the domestic kit has lower sensitivity but higher specificity.

[Research on the cone-beam CT of the fracture morphology and location of a single oblique complicated crown-root fracture of maxillary incisors]

Objective: To study the morphological pattern of single oblique complex crown fracture and its relative location to periodontal hard tissues from a three-dimensional perspective by using cone-beam CT, which provides a more intuitive and comprehensive understanding for the pathological features and rules of single oblique complex crown fracture. Methods: Primary cone-beam CT images of 56 maxillary permanent anterior teeth with oblique complex crown root fractures were collected from the Department of Integrated Emergency Dental Care, Capital Medical University School of Stomatology during January 2015 to January 2019. Fracture pattern, fracture angle, fracture depth, fracture width, and the relative location of the fracture line to the crest of the adjacent alveolar ridge were retrospectively analyzed. Independent samples t-test was used to compare the differences in angle, depth and width of fractures between sexes and tooth locations, as well as the pre-and post-fracture crown-to-root ratios between different tooth locations. Then the affected teeth were divided into juvenile group (≤18 years), young group (19-34 years) and middle-aged and elderly group (≥35 years). One-way ANOVA was applied to compare the differences in angle, depth and width of fracture between age groups, and Fisher exact test to compare the differences in fracture pattern of the teeth and the relative position of the fracture line to the crest of the adjacent alveolar ridge. Results: There were 35 males and 21 females in 56 patients, aged (28.2±13.2) years. Among the 56 affected teeth, forty-six were maxillary central incisors and 10 were lateral incisors. According to the patients' age and growing stage, they could be divided into the juvenile group (19 cases), the young group (14 cases), and the middle-aged and elderly group (23 cases). Forty-six (82%) affected teeth had an S-shaped fracture pattern, and ten (18%) had a diagonal pattern, in which the fracture angle of the S-shaped fracture line (47.85°±10.02°) was significantly greater than that of the diagonal line (28.30°±8.07°) (P<0.001). The fracture nadir was flush with or below the top of the alveolar crest in 98% (55/56) of cases. The fracture depth was significantly greater in the juvenile group [(1.75±0.73) mm] than in the young group [(1.21±0.68) mm](P=0.042) and in the middle-aged and elderly group [(1.12±0.90) mm] (P=0.001). The width of fractures among 56 patients was (4.75±1.44) mm, which had no statistically significant differences between different age, sex and tooth location groups (P>0.05). There were no statistically significant differences in the crown-to-root ratios after fracture of maxillary central incisors (1.18±0.13) compared to maxillary lateral incisors (1.14±0.20) (t=1.90, P=0.373). Conclusions: The fracture patterns of single oblique complex crown fracture were mainly S-shaped and oblique alignment; the fracture nadir was mostly located within 2.0 mm below the palatal alveolar crest.

Unambiguous Experimental Verification of Linear-in-Temperature Spinon Thermal Conductivity in an Antiferromagnetic Heisenberg Chain

The everlasting interest in spin chains is mostly rooted in the fact that they generally allow for comparisons between theory and experiment with remarkable accuracy, especially for exactly solvable models. A notable example is the spin-1/2 antiferromagnetic Heisenberg chain (AFHC), which can be well described by the Tomonaga-Luttinger liquid theory and exhibits fractionalized spinon excitations with distinct thermodynamic and spectroscopic experimental signatures consistent with theoretical predictions. A missing piece, however, is the lack of a comprehensive understanding of the spinon heat transport in AFHC systems, due to difficulties in its experimental evaluation against the backdrop of other heat carriers and complex scattering processes. Here we address this situation by performing ultralow-temperature thermal conductivity measurements on a nearly ideal spin-1/2 AFHC system copper benzoate Cu(C_{6}H_{5}COO)_{2}·3H_{2}O, whose field-dependent spin excitation gap enables a reliable extraction of the spinon thermal conductivity κ_{s} at zero field. κ_{s} was found to exhibit a linear temperature dependence κ_{s}∼T at low temperatures, with κ_{s}/T as large as 1.70  mW cm^{-1} K^{-2}, followed by a precipitate decline below ∼0.3  K. The observed κ_{s}∼T clarifies the discrepancies between various spin chain systems and serves as a benchmark for one-dimensional spinon heat transport in the low-temperature limit. The abrupt loss of κ_{s} with no corresponding anomaly in the specific heat is discussed in the context of many-body localization.

[Early outcomes of excimer laser atherectomy for below-the-knee lesions in patients with diabetic foot]

Objective: To evaluate the clinical outcomes of excimer laser atherectomy (ELA) in the treatment of diabetic foot with below-the-knee(BTK) lesions. Methods: The clinical data of 11 patients with diabetic foot with BTK lesions who underwent ELA at Department of Vascular Surgery,Zhongshan Hospital of Fudan University and Department of Vascular and Wound Treatment Center,Jinshan Hospital of Fudan University from September 2019 to May 2021 were retrospectively analyzed.There were 10 males and 1 female,aged 70.5 years(range:41 to 83 years).There were 20 lesions in 12 limbs,including 19 chronic total occlusion.All of the limbs were classified as Rutherford class 5 and suffered ulceration.The surgical efficacy,complications and ankle brachial index(ABI) after operation were record. Results: All patients underwent the operation successfully,the technical success rate was 12/12.No distal embolization,flow-limiting dissection,perforation or bailout stenting was occurred.The follow-up period was 8.2 months(range:3 to 13 months).The ABI increased from 0.58(range:0.24 to 1.57) before operation to 0.88(range:0.68 to 1.05) after operation.At 3 months after the operation,1 limb (1/12) underwent endovascular operation again due to restenosis,ulcers were healed in 5 limbs(5/12),and no amputation (limb/toe),death or loss of follow-up patients.Six months after the operation,2 patients were lost to follow-up and 2 died,ulcers were healed in 6 limbs(6/8),1 limb (1/8) underwent toe amputation due to prolonged healing of ulcers of toe. Conclusion: ELA is feasible and effective in the treatment of DF with BTK lesions,providing a new option of debulking atherectomy in such a group of patients.

Changes in the Management of Patients having Radical Radiotherapy for Lung Cancer during the First Wave of the COVID-19 Pandemic in the UK

AIMS

In response to the COVID-19 pandemic, guidelines on reduced fractionation for patients treated with curative-intent radiotherapy were published, aimed at reducing the number of hospital attendances and potential exposure of vulnerable patients to minimise the risk of COVID-19 infection. We describe the changes that took place in the management of patients with stage I-III lung cancer from April to October 2020.

MATERIALS AND METHODS

Lung Radiotherapy during the COVID-19 Pandemic (COVID-RT Lung) is a prospective multicentre UK cohort study. The inclusion criteria were: patients with stage I-III lung cancer referred for and/or treated with radical radiotherapy between 2nd April and 2nd October 2020. Patients who had had a change in their management and those who continued with standard management were included. Data on demographics, COVID-19 diagnosis, diagnostic work-up, radiotherapy and systemic treatment were collected and reported as counts and percentages. Patient characteristics associated with a change in treatment were analysed using multivariable binary logistic regression.

RESULTS

In total, 1553 patients were included (median age 72 years, 49% female); 93 (12%) had a change to their diagnostic investigation and 528 (34%) had a change to their treatment from their centre's standard of care as a result of the COVID-19 pandemic. Age ≥70 years, male gender and stage III disease were associated with a change in treatment on multivariable analysis. Patients who had their treatment changed had a median of 15 fractions of radiotherapy compared with a median of 20 fractions in those who did not have their treatment changed. Low rates of COVID-19 infection were seen during or after radiotherapy, with only 21 patients (1.4%) developing the disease.

CONCLUSIONS

The COVID-19 pandemic resulted in changes to patient treatment in line with national recommendations. The main change was an increase in hypofractionation. Further work is ongoing to analyse the impact of these changes on patient outcomes.

[Relationship of C1QA level and therapeutic effect and prognosis of DLBCL patients treated with R-CHOP]

Objective: To investigate the relationship between plasma levels of complements before treatment and the clinicopathological feathers and prognoses of diffuse large B-cell lymphoma (DLBCL) patients treated with Rituximab (R)-CHOP or R-CHOP-like therapy. Methods: The clinicopathological data of 105 DLBCL patients treated in cancer Hospital of Chinese Academy of Medical Sciences from 2010 to 2016 were collected. The plasma samples from 105 DLBCL patients treated with R-CHOP or R-CHOP-like therapy and 80 healthy controls were used to detect 34 complement levels before treatment by utilizing antibody microarray. The relationship between plasma levels of complements and the clinicopathological feathers and prognosis of DLBCL patients were analyzed. Results: The signal values of C1QA and CR1L in patients with international prognostic index (IPI) scores of 3-5 were 1 261.43±138.9 and 2 214.69±98.58, respectively, higher than 950.79±80.19 and 984.67±121.79 in patients with IPI scores of 0~2 (both P<0.05). The levels of C1QA and CR1L in the non-complete response (CR) group were 1 165.43±98.56 and 2 263.13±145.63, respectively, higher than 914.70±100.77 and 1 821.34±84.68 in the CR group (both P<0.05). Cox regression analysis showed that elevated C1QA signal value was associated with poor progression-free survival (PFS) and poor overall survival (OS) (PFS: HR=2.063, 95%CI: 1.220-3.489, P=0.007; OS: HR=2.23, 95%CI: 1.036~4.798, P=0.040). After IPI correction by Cox multivariate model, the elevated C1QA signal value was still correlated with poor PFS (HR=1.765, 95%CI 1.034~3.013, P=0.037). Conclusions: The baseline plasma levels of C1QA and CR1L are correlated with IPI scores and therapeutic effects of DLBCL patients treated with R-CHOP. The baseline plasma level of C1QA has a certain predictive value for the prognostic evaluation of DLBCL.

[Biomechanical study of anterior occipital condyle screw plate system]

Objective: To analyze the feasibility of anterior occipitocervical fusion biomechanical characteristic of craniovertebral reconstruction by anterior occipital condyle screw plate system. Methods: Six cervical vertebra specimens including 4 males and 2 females were enrolled, whose mean age of death was (49.3±7.5) years. The normal models were established by soft tissue dissection, and the instability models were established by destroy bone and ligament structure including, anterior arch of the atlas, part of the lateral mass of the atlas, the odontoid process, the odontoid apical ligament, the pterygoid ligament, the transverse ligament of the atlas the joint capsule. The clivus screw fixation models were established by anterior clivus screw fixation, and then those models were performed by anterior occipital condyle screw fixation. All four groups were loaded with a 1.5 N·m continuous pure force in flexion-extension, lateral bending, and axial rotation. Then measured the range of motion of specimen C₀-C₁ and C₀-C₂. And the pull-out force test was conducted to compare the effects of unicortical and bicortical fixation on the pull-out force of screws. Results: In the C₀-C₁ segment, the range of motion in flexion-extension (forward and posterior), lateral bending and axial rotation in the clivus group was 6.46°±0.85°, 5.14°±0.76°, 2.73°±0.36°, 1.12°±0.41°, respectively; and it was 5.92°±0.90°, 4.16°±1.06°, 2.86°±0.50°, 1.05°±0.27°, respectively in the occipital condyle group. As for C₀-C₂ segment, the range of motion in the clivus group was 9.55°±1.99°, 10.46°±2.03°, 6.90°±1.29°, 13.51°±1.37°, respectively; and it was 8.14°±1.38°, 9.53°±1.55°, 4.75°±1.06°, 7.90°±1.68°, respectively, in the occipital condyle group. The ranges of motion in the occipital condyle group were significantly lower than clivus group (all P<0.05). The maximum pull out force by bicortical fixation was significantly better than unicortical fixation ((439±33) N vs (408±28) N, P<0.05). Conclusion: The anterior occipital condyle screw plate system provides better stability especially in anti-bending and anti-rotation than the anterior clival screw fixation.

[Digital and anatomical study of posterior atlantooccipital joint-occipital condyle-clivus screw technique]

Objective: To investigate the screw placement parameters, feasibility and safety of posterior atlantooccipital joint-occipital condyle-clivus screw technique in Chinese people. Methods: Upper cervical spine CT images of 46 patients, including 24 males and 22 females, were collected with random number table from June 2019 to May 2020 in Ningbo No.6 Hospital. The patients aged 20-55 years, with a mean age of (39±9) years. Total of 92 sides of upper cervical spine models were obtained by Mimics 19.0 digital three-dimensional reconstruction, and screw placement was conducted simulately. The midpoint of transition zone between the posterior arch of atlas and the inferior articular process of lateral mass was selected as the screw entry point. The diameter and length of screws was 3.5 mm and 50 mm, respectively. Detailed morphometric measurements of the 92 atlantooccipital joint-occipital condyle-clivus screws were conducted. The distance between the screw and its surrounding important structures, screw inside and upper tilting angles, the length of screw trajectory in atlas and the length of screw trajectory on occipital side (occipital condyle-clivus) were all measured. Paired t test was performed on the parameters of left and right screw placement to confirm whether there was difference between the two sides. Results: In the 46 cases of upper cervical spine digital three-dimensional models, 92 posterior atlantooccipital joint-occipital condyle-clivus screws were implanted. All the screws were completely fixed in the clivus, without breaking through the upper sphenoid sinus, entering into the canalis spinalis and foramen magnum, and damaging the surrounding structures such as hypoglossal canal. The screw trajectory parameters between the left and right sides were slightly different, but there was no statistical differences between the two sides (P>0.05). The vertical distance between the screw entry point and the upper edge of atlas was (12.6±1.0) mm, the vertical distance between the screw entry point and the lower edge of atlas was (6.5±0.6) mm, the distance between the screw and the medial border of atlas vertebral artery foramen was (6.7±0.6) mm, the distance between the screw entry point and the medial wall of atlas was (6.6±0.7) mm, the distance between the screw outer margin and the hypoglossal canal was (5.5±0.6) mm, screw inside tilting angle was 21.2°±2.5°, screw upper tilting angle was 52.0°±3.4°, the length of screw trajectory in atlas was (12.1±0.9) mm, the length of screw trajectory on occipital side (occipital condyle-clivus) was (37.9±0.9) mm. Conclusion: The posterior atlantooccipital joint-occipital condyle-clivus screw technique can serve as a feasible and safe treatment for instability of the occipitocervical junction, which can be used as a new posterior occipitocervical fusion technique.

[Analysis of asymmetric hearing loss in both ears of patients with occupational noise-induced deafness]

Objective: To investigate the characteristics of asymmetric hearing loss in left and right ears of patients with occupational noise-induced deafness and to explore the possible causes of asymmetric hearing loss. Methods: A total of 423 cases of occupational noise-induced deafness diagnosed in Guangdong Province Hospital for Occupational Disease Prevention and Treatment from May 2015 to May 2018 were investigated retrospectively. On the basis of three consecutive pure tone audiometry (PTA) with intervals of more than 3 d in hospital, the minimum of hearing threshold of each frequency and the frequency response threshold of auditory steady-state response (ASSR) , and based on the GBZ 49-2014 "Diagnosis of Occupational Noise-induced Deafness". The statistical analysis of Wilcoxon signed rank test and Spearman correlation analysis were carried out by nonparametric test. The hearing threshold weight of PTA and the response threshold of ASSR were tested and compared from different dimensions according to sex, age, length of service of exposure noise, diagnosis grade and so on. Results: There were 369 male (87.23%) and 54 female (12.77%) ; the age was (41.8±7.6) years; the length of service was (10.1±6.2) years. The weighted values of left ear PTA and ASSR were higher than those of right ear (P<0.001) . The weighted values of left ear PTA and ASSR were higher than those of right ear (P<0.05) in men, patients with age ≤ 40 and 41-60 years, 3-9 years of service, and patients with mild grade (P<0.05) . After the equalization of characteristic variables, the weighted values of left ear PTA and ASSR were also higher than those of right ear (P<0.05) . There was a positive correlation between the weighted value of PTA and the weighted value of ASSR (P<0.001) . Conclusion: There is asymmetry in hearing loss of patients with occupational noise deafness, and hearing loss in the left ear is higher than that in the right ear.

[Comparison the efficacy and prognosis of different first-line treatment for elderly diffuse large B-cell lymphoma]

Objective: To investigate the clinical features, survival and prognostic factors of elder patients with diffuse large B-cell lymphoma (DLBCL). Methods: The clinical data of elder patients with diffuse large B-cell lymphoma enrolled in the Cancer Hospital of Chinese Academy of Medical Sciences from April 2006 to December 2012 were retrospectively collected. All the patients were divided into R-CHOP-like group and CHOP-like group according to the dosage regimen. And the differences in demographic characteristics, clinical features, survival time and prognostic factors were compared between these two groups. Results: A total of 158 patients were enrolled, of which 78 patients in the R-CHOP-like group and 80 patients in the CHOP-like group were eligible. There were no significant differences between two groups on age, gender, pathological staging, B symptoms, bulky mass, ECOG score, IPI score, pathological type, LDH level, β(2)-MG level, lymphocyte/monocyte ratio(LMR), neutrophils/lymphocyte ratio(NLR), platelet/lymphocyte ratio(PLR), Ki-67 index and bone marrow invasion. In the R-CHOP like group, the median progression-free survival (PFS) time was 10 months, and the median overall survival (OS) time was 30 months. The 1-year and 2-year PFS rates were 46.2% and 19.2%, respectively. The 1-, 2-, and 5-year OS rates were 79.5%, 59.0%, and 19.2%, respectively. In the CHOP-like group, the median PFS was 7 months, and the median OS was 15 months. The 1-year and 2-year PFS rates were 27.5% and 12.5% respectively. The 1-year, 2-year, and 5-year OS rates were 65.0%, 32.5% and 13.8%, respectively. The median PFS time and OS time in the R-CHOP group were significantly better than those in the CHOP group (P<0.05 for both). A stratified analysis showed that the PFS time and OS time were superior in the R-CHOP-like group compared to the CHOP-like group among patients older than 70 years (P<0.05 for both). In patients with stage Ⅲ-Ⅳ, the PFS time and OS time in the R-CHOP-like group were also superior to CHOP-like group (P<0.05 for both). Univariate Cox regression analysis showed that IPI score, LDH value, β(2)-MG value, ECOG score, LMR, and PLR had an significant effect on prognosis (P<0.05 for all). Multivariate Cox regression analysis showed that lymphocyte/monocyte ratio and platelet/lymphocyte ratio were independent prognostic factors for diffuse large B-cell lymphoma (P<0.05 for both). Conclusions: The R-CHOP-like chemotherapy regimen is superior to the CHOP-like regimen in the first-line treatment of patients with diffuse large B-cell lymphoma. ECOG score, LMR and PLR may be independent prognostic factors for diffuse large B-cell lymphoma. ECOG score, LMR and PLR are independent prognostic factors.

[Vestibular incision subperiosteal tunnel access with connective tissue graft for the treatment of Miller classI and II gingival recession]

OBJECTIVE

To evaluate the clinical outcomes of vestibular incision subperiosteal tunnel access (VISTA) with connective tissue graft (CTG) in the treatment of Miller classes I and II localized gingival recession.

METHODS

Ten patients with 10 Miller classes I and II localized gingival recessions were enrolled in the study. All defects were equal to or above 2 mm in recession depth. All the patients received treatment with VISTA+CTG. Their clinical parameters, including recession depth (Rec), recession width (RW), keratinized tissue width (KT), clinical attachment loss (CAL), probing depth (PD) were recorded and compared before surgery and 6 months later. The mean root coverage (MRC) and complete root coverage (CRC) were calculated at the end of 6 months. A visual analogue scale (VAS) was used to estimate the patients' discomfort during the operation and during the 2 weeks post-operation. Patient-based aesthetic satisfaction 6 months after surgery was evaluated by a VAS.

RESULTS

The mean Rec was (2.65±0.82) mm at baseline, and (0.35±0.58) mm after 6 months. The VISTA+CTG treatment resulted in an improvement of (2.30±0.98) mm in recession depth (P<0.001). MRC was 86.67%±21.94% and CRC reached 70% at the end of 6 months. KT increased (0.90±1.22) mm (P<0.05). Aesthetic satisfaction on the patients' level was 8.30 based on VAS (0=unsatisfied, 10=extremely satisfied). The patients' discomfort during the operation and 2 weeks post operation were 2.40 and 4.30 (0=no pain, 10=extreme pain). Furthermore, clinical outcomes showed no statistically significant difference between the gingival biotypes, and between the teeth positioned in maxillary and in mandibular.

CONCLUSION

VISTA+CTG could be an effective treatment for Miller classes I and II localized gingival recession. Clinical outcomes indicated decrease in recession depth and width, and increase in width of keratinized tissue. Patients suffered little pain during the operation and 2 weeks post-operation of healing and accessed good aesthetic satisfaction. VISTA+CTG could be an option for the treatment of Miller classes I and II localized gingival recession.

[Regulation of hypoxia inducible factor-1α on permeability of vascular endothelial cells and the mechanism]

Objective: To investigate the regulation of hypoxia-inducible factor-1α (HIF-1α) on permeability of rat vascular endothelial cells and the mechanism. Methods: Twelve male Sprague-Dawley rats aged 35 to 38 days were collected and vascular endothelial cells were separated and cultured. The morphology of cells was observed after 4 days of culture, and the following experiments were performed on the 2nd or 3rd passage of cells. (1) Rat vascular endothelial cells were collected and divided into blank control group, negative control group, HIF-1α interference sequence 1 group, HIF-1α interference sequence 2 group, and HIF-1α interference sequence 3 group according to the random number table (the same grouping method below), with 3 wells in each group. Cells in negative control group, HIF-1α interference sequence 1 group, HIF-1α interference sequence 2 group, and HIF-1α interference sequence 3 group were transfected with GV248 empty plasmid, recombinant plasmid respectively containing HIF-1α interference sequence 1, interference sequence 2, and interference sequence 3 with liposome 2000. Cells in blank control group were only transfected with liposome 2000. After transfection of 24 h, expression levels of HIF-1α mRNA and protein of cells in each group were respectively detected by reverse transcription real-time fluorescent quantitative polymerase chain reaction and Western blotting (the same detecting methods below) . The sequence with the highest interference efficiency was selected. (2) Another batch of rat vascular endothelial cells were collected and divided into blank control group, negative control group, and HIF-1α low expression group, with 3 wells in each group. Cells in blank control group were only transfected with liposome 2000, and cells in negative control group and HIF-1α low expression group were respectively transfected with GV248 empty plasmid and low expression HIF-1α recombinant plasmid selected in experiment (1) with liposome 2000. After 14 days of culture, the mRNA and protein expressions of HIF-1α in each group were detected. (3) Another batch of rat vascular endothelial cells were collected and divided into blank control group, negative control group, and HIF-1α high expression group, with 3 wells in each group. Cells in blank control group were transfected with liposome 2000, and cells in negative control group and HIF-1α high expression group were respectively transfected with GV230 empty plasmid and HIF-1α high expression recombinant plasmid with liposome 2000. After 14 days of culture, the mRNA and protein expressions of HIF-1α of cells in each group were detected. (4) After transfection of 24 h, cells of three groups in experiment (1) and three groups in experiment (2) were collected, and mRNA and protein expressions of myosin light chain kinase (MLCK), phosphorylated myosin light chain (p-MLC), and zonula occludens 1 (ZO-1) of cells were detected. Data were processed with one-way analysis of variance and t test. Results: After 4 days of culture, the cells were spindle-shaped, and rat vascular endothelial cells were successfully cultured. (1) The interference efficiencies of HIF-1α of cells in HIF-1α interference sequence 1 group, HIF-1α interference sequence 2 group, and HIF-1α interference sequence 3 group were 47.66%, 45.79%, and 62.62%, respectively, and the interference sequence 3 group had the highest interference efficiency. After transfection of 24 h, the mRNA and protein expression levels of HIF-1α of cells in interference sequence 3 group were significantly lower than those in blank control group (t=18.404, 9.140, P<0.01) and negative control group (t=15.099, 7.096, P<0.01). (2) After cultured for 14 days, the mRNA and protein expression levels of HIF-1α of cells in HIF-1α low expression group were significantly lower than those in blank control group (t=21.140, 5.440, P<0.01) and negative control group (t= 14.310, 5.210, P<0.01). (3) After cultured for 14 days, the mRNA and protein expression levels of HIF-1α of cells in HIF-1α high expression group were significantly higher than those in blank control group (t=19.160, 7.710, P<0.01) and negative control group (t= 19.890, 7.500, P<0.01). (4) After transfection of 24 h, the mRNA expression levels of MLCK and p-MLC of cells in HIF-1α low expression group were significantly lower than those in blank control group (t=2.709, 4.011, P<0.05 or P<0.01) and negative control group (t=2.373, 3.744, P<0.05 or P<0.01). The mRNA expression level of ZO-1 of cells in HIF-1α low expression group was significantly higher than that in blank control group and negative control group (t=4.285, 5.050, P<0.01). The mRNA expression levels of MLCK and p-MLC of cells in HIF-1α high expression group were significantly higher than those in blank control group (t=9.118, 11.313, P<0.01) and negative control group (t=9.073, 11.280, P<0.01). The mRNA expression level of ZO-1 of cells in HIF-1α high expression group was significantly lower than that in blank control group and negative control group (t=2.889, 2.640, P<0.05). (5) After transfection of 24 h, the protein expression levels of MLCK and p-MLC of cells in HIF-1α low expression group were significantly lower than those in blank control group (t=2.652, 3.983, P<0.05 or P<0.01) and negative control group (t=2.792, 4.065, P<0.05 or P<0.01). The protein expression of ZO-1 of cells in HIF-1α low expression group was significantly higher than that in blank control group and negative control group (t=3.881, 3.570, P<0.01). The protein expression levels of MLCK and p-MLC of cells in HIF-1α high expression group were 1.18±0.24 and 0.68±0.22, which were significantly higher than 0.41±0.21 and 0.35±0.14 in blank control group (t=5.011, 3.982, P<0.05 or P<0.01) and 0.43±0.20 and 0.36±0.12 in negative control group (t= 4.880, 3.862, P<0.05 or P<0.01). The protein expression level of ZO-1 of cells in HIF-1α high expression group was 0.08±0.06, which was significantly lower than 0.20±0.09 in blank control group and 0.19±0.09 in negative control group (t=4.178, 3.830, P<0.05 or P<0.01). Conclusions: HIF-1α up-regulates expressions of MLCK and p-MLC and down-regulates expression of ZO-1, thereby increasing the permeability of rat vascular endothelial cells.

[The clinical and pathological features, biomarker characteristics and prognosis analysis of lung adenosquamous carcinoma]

Objective: Adenosquamous carcinoma of lung is an uncommon subtype with more aggressive behavior and poor prognosis than adenocarcinoma and squamous cell carcinoma. This study was aimed to investigate the clinicopathological characteristics and prognostic factors of lung adenosquamous carcinoma. Methods: The pathological features and follow-up data of 133 patients were collected and the prognostic factors of these patients were retrospectively analyzed. Results: Among the 133 patients, 81 cases (60.9%) smoked. Among the 62 patients whose percentage of histological components were identified, 45 cases had >50% adenocarcinoma components, and 17 cases had >50% squamous cell carcinoma components. 55 patients had lymph node metastasis at the first visit. All patients accepted at least one test of tumor driven gene mutation, and the results showed that the mutation rate of EGFR was 50.8% (67/132), the mutation rate of K-ras was 8.6% (11/128), the ALK-positive rate was 4.2% (2/48). The gender, smoking status, and the proportion of pathological components were the main influence factors of EGFR mutation status. The median overall survival was 28 months, the rates of 1-year, 3-year, and 5-year survival were 72.9%, 23.3%, and 9.0%, respectively. EGFR tyrosine kinase inhibitors (TKIs) treatment was an independent risk factor for prognose of these patients (P=0.024). Conclusions: Lung adenosquamous carcinoma is a rare subtype with high malignancy and poor prognosis. Early diagnosis and driven-mutation-based individualized therapy may improve the survival of patients with lung adenosquamous carcinoma.

[The analyze the epidemic trend and predict the incidence trend of occupational diseases in Guangdong province]

Objective: This study was aimed to analyze the epidemic trend and predict the incidence trend of occupational diseases during 2006-2015 in Guangdong province, which may provide the theoretical foundation for occupational disease risk assessment and precise control and prevention. Methods: We analyzed the number of reported occupational disease cases, the constituent ratio, the average age and working-age of patients. We also performed the linear-by-linear association test of new incidence, median age and median working-age by curve-fitting method, of which the diagnostic year was set as the independent variable. Meanwhile, we designed an ARIMA model to predict the variation tendency of occupational diseases in 2017-2020. Results: (1) During 2006-2015, the total reported cases of occupational disease is 5289, including 2101 cases of occupational pneumoconiosis (39.7%) , 1363 cases of occupational poisoning (25.8%) , and 864 cases of occupational otolaryngological and stomatological disease (16.3%) . (2) The number of occupational diseases and pneumoconiosis have a straight upward trend (R(2)=0.851, R(2)=0.856) , while the number of occupational otolaryngological and stomatological disease and occupational tumor have a exponential trend (R(2)=0.914, R(2)=0.696) . The constituent ratio of occupational poisoning is decreasing, and the constituent ratio of occupational otolaryngological and stomatological disease is increasing. (3) The average onset age is 40 (33, 46) years old, and the average onset working-age is 6 (3, 11) years. Both of them have a straight upward trend (R(2)=0.954、R(2)=0.792) . The onset age of pneumoconiosis, occupational poisoning and occupational otolaryngological and stomatological disease have a upward trend. In addition, the onset working-age of occupational poisoning and pneumoconiosis have a upward trend. (4) The number of occupational diseases in 2017-2020 is predicted to be between 902-1231. Conclusion: Occupational diseases in Guangdong province showed a trend of high incidence. The age and working-age of occupational diseases showed an extended trend. Therefore, our work of occupational epidemic trend may provide some bases for the occupational disease risk assessment and precise control and prevention.

[Clinical characteristics and prognosis analysis of 46 cases of newly diagnosed localized head and neck rhabdomyosarcoma]

Objective: To analyze the clinical characteristics and prognosis of newly diagnosed localized head and neck rhabdomyosarcoma. Methods: Cases of newly diagnosed localized head and neck rhabdomyosarcoma between January 2006 and December 2016 were analyzed retrospectively. The clinical features of the patients were described. The Kaplan-Meier method was used to analyze the survival rate under different combined modality therapy and the survival rate with or without chemotherapy. The prognostic factors were analyzed by Cox model. Results: A total of 46 patients were included in this study. Among them, the median follow-up time was 77 months and the median relapse free survival time was 13 months. The relapse free survival time of 5 cases with inadequate local treatment and without combined chemotherapy was 5 months as control, and it was 7 months (P=0.110) in 11 cases with adequate local treatment without combined chemotherapy. Then in 7 cases with inadequate local treatment combined with chemotherapy and 23 cases with adequate local treatment combined with chemotherapy, it was 13 months (P=0.007) and 21 months (P<0.001), respectively. The median relapse-free survival time of chemotherapy patients was significantly longer than that of those without chemotherapy (21 vs 6 months, P=0.018). The effect of combined modality therapy was evaluated according to the adequacy of local treatment and whether to receive systemic chemotherapy, and the combined modality therapy degree was the independent prognostic factor in Cox's proportional hazards regression model (P=0.004). Conclusions: Rhabdomyosarcoma in head and neck is a highly malignant tumor with high relapse rate and easy metastasis. In patients with tolerable condition, systemic chemotherapy and adequate combined modality therapy are recommended to improve relapse-free survival.

[Prospect for chimeric antigen receptor-engineered T cell immunotherapy for solid tumors]

Chimeric antigen receptor modified T cell (CAR T) cytotherapy is a modified technology of T cell immunotherapy. It has achieved encouraging breakthroughs in the treatment of hematological malignancies. Recent studies had shown that CAR T cells can also be used in the treatment of solid tumors. However, it's indispensable to understand its bottlenecks, including regulating CAR T cell expansion, survival time, metastasis, and prognosis in vivo, to establish a feasible and effective CART-based solid tumor therapy model. Therefore, we summarized the advances, challenges and possible solutions for CAR T therapy to treat solid tumors, and then prospected in the future clinical treatment.

[Clinical characteristics and treatment strategies for early-stage primary gastric diffuse large B-cell lymphoma]

Objective: Primary gastric diffuse large B-cell lymphoma (PG-DLBCL) is the most common non-Hodgkin lymphoma (NHL) of extranodal origin. Most patients with PG-DLBCL had localized disease (stage Ⅰ or Ⅱ) at presentation, and will achieve complete response (CR) after induction chemotherapy. However, there has been little consensus regarding whether optimal treatment is provided by chemotherapy alone or chemotherapy plus radiotherapy, nor the treatment outcome from the addition of rituximab in localized-stage PG-DLBCL. Methods: Patients with Stage ⅠE and ⅡE PG-DLBCL were retrospectively analyzed. Patients have not undergone surgery, have received at least 3 cycles of R-CHOP or CHOP-like chemotherapy as initial therapy, and achieved CR or partial response (PR) were enrolled. Results: A total of 91 patients were studied. The median age was 51 years, included 47 males and 44 females. Fifty-two patients were at Stage ⅠE and 39 at Stage ⅡE, 64 (70.3%) patients received R-CHOP-like regimens, and 27 (29.7%) received CHOP-like regimens, the median chemotherapy cycle was 6 (3-8). Among the 91 patients, 80 (87.9%) patients achieved CR from induction chemotherapy, 11(12.1%) was evaluated PR. Of CR patients, 48 patients (60%) underwent consolidating radiotherapy and 32 patients (40%) did not receive radiotherapy; all PR patients received salvage radiotherapy. CR patients with and without radiation therapy had 4-year progression-free survival (PFS) rates of 96.4% and 96.7%, respectively (χ(2) = 0.546, P=0.46); 7/11 (63.6%) PR patients achieved CR after radiotherapy, with a median follow-up of 41 months, they were all disease free. For patients treated with R-CHOP or CHOP-like regimens, the 4-year PFS was 93.2% and 89.7%, respectively (χ(2)=0.096, P=0.757). Conclusions: Consolidation radiotherapy failed to improve the outcome for early-stage PG-DLBCL, while for PR patients, salvage radiotherapy increased CR rate and improved survival. The addition of rituximab to CHOP did not improve the efficacy.

[Retrospective analysis of the clinical features and prognostic factors of 370 patients with advanced-stage diffuse large B-cell lymphoma]

Objective: The clinical features and prognosis of diffuse large B-cell lymphoma (DLBCL) were analyzed to optimize the treatment. Methods: We retrospectively collected the clinical data of patients with advanced-stage DLBCL from January 2006 to December 2012 in National Cancer Center/Cancer Hospital. The demographic characteristics, clinical stage, histological diagnosis, treatment and prognostic characteristics of these patients were analyzed. Results: A total of 370 patients with median age of 55 years old were recruited in the study. The male-to-female ratio was 1.3∶1. Among the 361 patients who underwent therapy, 280 cases received chemotherapy alone, 65 cases received chemoradiotherapy, and 16 cases received chemotherapy combined with autologous hematopoietic stem cell transplantation (AHSCT). The median follow-up period was 89 months, the 5-year overall survival (OS) rate of the entire cohort was 42.9%. The 5-year OS rate of chemotherapy alone, chemoradiotherapy and chemotherapy combined with AHSCT were 36.8%, 58.5%, 87.5%, respectively. The 5-year OS rate were significantly different between chemoradiotherapy and chemotherapy alone (P=0.001), and between chemotherapy combined with AHSCT and chemoradiotherapy (P=0.040). Univariate analysis showed that the age, Eastern Cooperative Oncology Group performance status (ECOG PS) score, Ann Arbor stage, B symptom, bulky disease, number of extranodal sites, Ki-67 index, lactate dehydrogenase (LDH), β2-microglobulin (β2-MG), international prognostic index (IPI), therapeutic manner and chemotherapy combined with rituximab were significantly associated with the prognosis of advanced DLBCL patients (all P<0.05). Multivariate analysis demonstrated that the age >60 years, Ann Arbor stage IV, with B symptom, with bulky disease, ECOG PS≥1, Ki-67 index > 90%, CD5 expression, up-regulation of serum LDH and β2-MG, and chemotherapy without rituximab were related with the poor prognosis of patients with advanced-stage DLBCL (all P<0.05). Conclusions: Chemotherapy combined with rituximab can improve the outcome of patients with advanced-stage DLBCL. The age, stage, B symptom, bulky disease, ECOG PS score, Ki-67 index, CD5 expression, LDH, β2-MG and chemotherapy combined with rituximab are associated with the prognosis of these patients.

[Short-term clinical safety and efficacy of No-touch great saphenous vein harvesting technique for off-pump coronary artery bypass grafting]

Objective: To evaluated early clinical outcomes of saphenous vein grafts harvested with a No-touch technique in off-pump coronary artery bypass graft (OPCABG) surgery. Methods: A total of 124 patients with three-vessel disease undergoing OPCABG by No-touch technique between June and November 2017 in Beijing An Zhen Hospital were respectively reviewed. Results: The average age of patients was (60.7±10.3) years, and 80 cases (64.5%) were male, with the average body mass index (BMI)of (25.4±2.5) kg/m(2,) the mean preoperative left ventricular ejection fraction (LVEF) of (58.0±7.0%). The operative time was (4.0±0.4) hours, and 16 cases (12.9%) were harvested for whole vein grafts. The number of vein grafts and venous anastomoses was 144 and 284, respectively. There were 16 cases of single bridge NTSVG-LAD, 4 cases of single bridge NTSVG-D, 99 cases of sequential bridge NTSVG-OM-PDA, 5 cases of sequential bridge NTSVG-OM-PLV, 4 cases of sequential bridge NTSVG-OM-RCA, 16 cases of sequential bridge NTSVG-D-OM-PDA. The mean flow volume of No-touch vein grafts was (51.9±2.4) ml/min. There was no death case in hospital. Postoperative re-exploration for hemorrhage of anastomosis happened in 1 case (0.8%), which was caused by pericardial tamponade due to insufficiency of hemostasis in internal mammary bed. There were 1 case of bad wound healing of lower extremity incision (0.8%). A total of 124 cases were followed up after operation, and the follow-up rate was 100%. There was one all-cause death (0.8%) 27 days after the operation. Conclusion: The short-term clinical observation of the application of No-touch great saphenous vein harvesting technique for OPCABG is safe and effective.

[Forensic Pathological Examination on 73 Medical Malpractice Cases of Pediatrics]

OBJECTIVES

To analyse 73 medical malpractice cases of pediatrics for discussing the importance of forensic pathology in solving the issues such as medical malpractice of pediatrics.

METHODS

From January 2002 to August 2016, 73 medical malpractice cases of pediatrics with age of death between 28 days old and 10 years old were collected from Institute of Judical Expertise of Nanjing Medical University. The relationship between causes of death and related medical institutions was retrospectively analysed.

RESULTS

In 73 cases, the male to female ratio was 1.70∶1, and ages of 28 days old to 1 year old were common （26 cases, 35.62%）, followed by ages between 1 year old and 3 years old （21 cases, 28.77%）. In 71 cases which had been determined the cause of death by postmortem examination, the main cause of death was disease, especially respiratory diseases （33 cases, 46.48%）, followed by cardiovascular diseases （12 cases, 16.90%）. In 75 medical institutes which involved with these medical malpractices, most were tertiary medical institutes （32, 42.67%）, followed by the sub-secondary （excluding the secondary） medical institutions （23, 30.67%）. The clinical diagnosis of 38 cases （52.05%） completely or mostly corresponded with the pathological findings. There were 35 cases （47.95%） undefined or misdiagnosed cases.

CONCLUSIONS

Autopsy and forensic pathological examination contribute to determine causes of death, which not only provide scientific evidence for medical malpractice of pediatrics, but also enrich and develop clinical medical knowledge, and thus improve diagnosis and treatment level in a certain extent.

[Prognostic significance of inflammatory indicators for advanced-stage diffuse large B-cell lymphoma]

Objective: To explore the prognostic significance of inflammatory indicator, neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR), for advanced-stage diffuse large B-cell lymphoma (DLBCL). Methods: The data of advanced stage DLBCL cases was retrospectively collected, and all the patients were seen from January 2006 to December 2012 in National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences. The patients were divided into the low NLR group (≤5∶1) and the high NLR group (>5∶1); the low PLR group (≤300∶1) and the high PLR group (>300∶1). Kaplan-Meier method was used to compare the survival rates between groups, multivriate Cox proportional hazard regression analysis was performed to assess the independent prognostic significance of clinical and histopathological variables on events or OS. Results: A total of 361 patients were included in the study. Under a median follow-up of 89 months, the 5-year overall survival (OS) and progression-free survival (PFS) of the whole group were 42.9% and 31.3%, respectively. The 5-year OS rate and PFS rate were 48.2% and 35.1% in the low NLR group, which were 24.1% and 17.7% in the high NLR group, respectively. The 5-year OS rates and PFS rate were 45.4% and 33.2% in the low PLR group, which were 29.8% and 21.1% in the high PLR group (all P<0.05). Univariate analysis showed that NLR >5∶1, PLR >300∶1, age>60 year, ECOG PS>1 score, stage Ⅳ, B symptom, bulky disease, number of extranodal sites >1, Ki-67index >90%, LDH elevated and β2-MG elevated had significant influence on prognosis(all P<0.05). Multivariate analysis demonstrated that NLR, stage, B symptom, bulky disease, ECOG PS score, Ki-67 index and β2-MG were associated with poor prognosis in the advanced-stage DLBCL. Conclusions: NLR was simple and feasible biomarker for prognosis of advanced-stage DLBCL patients.

[Clinicopathologic study of pediatric vascular anomalies: a report of 117 cases]

OBJECTIVE

To study the clinicopathologic features of pediatric vascular anomalies and application of ISSVA classification.

METHODS

The clinical features, histopathologic findings and immunohistochemical results were analyzed in 117 cases of pediatric vascular anomalies encountered during the period from May 2014 to May 2015.

RESULTS

A total of 117 cases of vascular anomalies were studied. The age of patients ranged from 18 hours after birth to 11 years (mean age =34 months and median age =27 months). There were 73 male patients and 44 female patients, with the male-to-female ratio being 1.7∶1.0. Congenital skin lesions were found in 37 cases (31.6%). The common sites of involvement included head and neck region (46 cases, 39.3%), trunk (28 cases, 23.9%), extremities (14 cases, 12.0%) and internal viscera (31 cases, 26.5%). According to the new ISSVA classification, there were 74 cases of vascular malformations and 43 cases of vascular neoplasms (ratio=1.7∶1.0). The commonest vascular tumor encountered was infantile hemangioma (21 cases, 48.8%), including 17 cases in proliferative phase and 4 cases in involutive phase. Thirteen cases (23.3%) of congenital hemangioma were found, with 8 cases of rapidly involuting congenital hemangioma and 5 cases of non-involutive congenital hemangioma. Three of the congenital hemangioma occurred in liver. There were 5 cases (11.6%) of pyogenic granuloma, 3 cases (7.0%) of tufted angioma and 1 case (2.3%) of Kaposiform hemangioendothelioma. Amongst the 74 cases of vascular malformations encountered, lymphatic malformation was found in 47 cases (63.5%), venous malformation in 15 cases (20.2%), lymphatic-venous malformation in 11 cases (14.9%) and arteriovenous malformation in 1 case (1.4%). All cases of vascular anomalies were all positive for CD31 on immunostaining. Glut1 and CD15 were positive both in proliferative and involutive phases of the 21 cases of infantile hemangioma, while other vascular tumors and vascular malformations were negative. Forty-seven cases of lymphatic malformation and 11 cases of lymphatic-venous malformation showed D2-40 expression. Focal positivity for D2-40 was demonstrated in 3 cases of tufted angioma and 1 case of Kaposiform hemangioendothelioma.

CONCLUSIONS

Vascular anomalies affecting infants and children include tumors and malformations. Accurate histopathologic diagnosis and ISSVA classification of the various types of vascular anomalies play an important role in clinical management.

[Clinical features and outcomes: analysis of 9 cases of HIV-negtive plasmablastic lymphoma]

Objective: To evaluate the clinical features and outcomes of HIV-negtive plasmablastic lymphoma (PBL). Methods: Nine patients with HIV-negtive PBL were diagnosed and treated between January 2006 and January 2016. The clinical and follow-up data were analyzed retrospectively. Results: The median age was 56 years (range 30-77 years) with a male-to-female ratio of 2∶1. Nobody had underlying diseases associated with immunosuppression. Primary extra nodal diseases were observed in 7 cases and only 1 patient had oral involvement. Two patients were in earlystage and 7 in advanced stage by the Ann Arbor stage system. Ki-67 index was 60%-90% in the 9 cases, and 80% or higher in 7 cases. Epstein-Barr virus-encoded RNA expression (EBER) was detected in 4 cases, and 2 of them were positive. Chemotherapy was documented in 9 patients, from which 8 received the cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP)-like regimens as the first-line chemotherapy and responses were observed in 5 (1 complete, 4 partial responses). Three elderly patients were treated with CHOP combined with thalidomide, and 2 of them achieved partial responses. One patient, failed three chemotherapy regimens, accepted thalidomide combined with etopside and achieved stable disease for 10 months. One patient with early stage had disease-free survival of 61.9 months after treatment. The other eight patients experienced recurrence or progression after the first-line chemotherapy, and 6 of them died of disease progression within 2 years after the diagnosis. Conclusion: The HIV-negative PBL patients in this study did not have an apparent association with immunosuppression. Primary extra nodal diseases were common, but only 1 patient had oral involvement. Most patients had advanced stage and poor prognosis. Effectiveness of thalidomide in the treatment of PBL deserves further investigation.

[Clinical features and prognosis of CD20-positive classical Hodgkin lymphoma]

OBJECTIVE

To explore the clinical characteristics and prognosis of CD20-positive classical Hodgkin lymphoma (CHL).

METHODS

Data from CHL patients with CD20 immunohistochemical staining result who were treated in Cancer Hospital of Chinese Academy of Medical Sciences between September 2007 and March 2014 were reviewed. The relationship of CD20 expression in Reed-Sternberg(R-S)cells with CHL subtypes, clinical characteristics, and prognosis were analyzed. Fisher test was used to analyze the differences between groups and Kaplan-Meier for survival analysis.

RESULTS

A total of 263 patients were included in this study. Among the 263 patients, 74 (28.1%) were CD20-postitive. CD20-positive cases showed significantly higher proportions of Epstein-Barr virus (EBV) infection-related, mixed cellularity, and lymphocyte-rich CHL subtypes compared with CD20-negeative patients [52.8% (28/53) vs 19.0% (22/116), 37.9% (25/66) vs 31.6% (54/171), 22.7% (15/66) vs 3.5% (6/171), all P<0.05]. Univariate analysis identified EBV infection, age (≥ 40 years, especially ≥ 60 years), and Ⅲ-Ⅳ stage were correlated with reduced 3-year progression-free survival (PFS) and overall survival (OS) (PFS: 70.3 vs 87.7%, 79.2% vs 89.8%, 56.8% vs 91.5%, 70.4% vs 93.2%; OS: 81.0% vs 100%, 92.1% vs 99.4%, 75.4% vs 99.2%, 90.3% vs 100%; all P<0.05); and CD20-positive and not receiving local radiotherapy were associated with reduced PFS (79.7% vs 90.6%, 68.8% vs 90.6%, both P<0.05), not with OS (92.4% vs 98.3%, 94.0% vs 99.4%, both P>0.05). Patients positive in both CD20 expression and EBV-encoded small RNAs (EBER) showed low PFS.

CONCLUSIONS

CD20 expression in R-S cells in CHL may be closed related with EBV infection. EBV infection is associated with unfavorable prognosis. The effect of CD20-postitive on prognosis may be mediated by the prognostic effect of EBV infection.

Glass-like recovery of antiferromagnetic spin ordering in a photo-excited manganite Pr₀.₇Ca₀.₃MnO₃

Electronic orderings of charges, orbitals and spins are observed in many strongly correlated electron materials, and revealing their dynamics is a critical step toward undertsanding the underlying physics of important emergent phenomena. Here we use time-resolved resonant soft x-ray scattering spectroscopy to probe the dynamics of antiferromagnetic spin ordering in the manganite Pr₀.₇Ca₀.₃MnO₃ following ultrafast photo-exitation. Our studies reveal a glass-like recovery of the spin ordering and a crossover in the dimensionality of the restoring interaction from quasi-1D at low pump fluence to 3D at high pump fluence. This behavior arises from the metastable state created by photo-excitation, a state characterized by spin disordered metallic droplets within the larger charge- and spin-ordered insulating domains. Comparison with time-resolved resistivity measurements suggests that the collapse of spin ordering is correlated with the insulator-to-metal transition, but the recovery of the insulating phase does not depend on the re-establishment of the spin ordering.

Characterization of microsatellite loci in the lesser dawn bat (Eonycteris spelaea)

We constructed a genomic DNA library enriched for CA repeat motifs in Eonycteris spelaea. Nine microsatellite loci were isolated and tested on a population of 39 samples from Yunnan Province, China. These nine loci had three to 22 alleles per locus. Observed and expected heterozygosity values ranged from 0.079 to 0.963 and from 0.078 to 0.959. Two loci revealed significant departure from Hardy-Weinberg equilibrium and no linkage disequilibrium was found between loci pairs. These microsatellites can be a powerful molecular tool for population-level studies of E. spelaea.

Real-time manifestation of strongly coupled spin and charge order parameters in stripe-ordered La(1.75)Sr(0.25)NiO(4) nickelate crystals using time-resolved resonant x-ray diffraction

We investigate the order parameter dynamics of the stripe-ordered nickelate, La(1.75)Sr(0.25)NiO(4), using time-resolved resonant x-ray diffraction. In spite of distinct spin and charge energy scales, the two order parameters' amplitude dynamics are found to be linked together due to strong coupling. Additionally, the vector nature of the spin sector introduces a longer reorientation time scale which is absent in the charge sector. These findings demonstrate that the correlation linking the symmetry-broken states does not unbind during the nonequilibrium process, and the time scales are not necessarily associated with the characteristic energy scales of individual degrees of freedom.

Ferromagnetic enhancement of CE-type spin ordering in (Pr,Ca)MnO3

We present resonant soft x-ray scattering results from small bandwidth manganites (Pr,Ca)MnO(3), which show that the CE-type spin ordering (SO) at the phase boundary is stabilized only below the canted antiferromagnetic transition temperature and enhanced by ferromagnetism in the macroscopically insulating state (FM-I). Our results reveal the fragility of the CE-type ordering that underpins the colossal magnetoresistance effect in this system, as well as an unexpected cooperative interplay between FM-I and CE-type SO which is in contrast to the competitive interplay between the ferromagnetic metallic state and CE-type ordering.

Quantum criticality and nodal superconductivity in the FeAs-based superconductor KFe2As2

The in-plane resistivity rho and thermal conductivity kappa of the FeAs-based superconductor KFe2As2 single crystal were measured down to 50 mK. We observe non-Fermi-liquid behavior rho(T) approximately T{1.5} at H{c{2}}=5 T, and the development of a Fermi liquid state with rho(T) approximately T{2} when further increasing the field. This suggests a field-induced quantum critical point, occurring at the superconducting upper critical field H{c{2}}. In zero field, there is a large residual linear term kappa{0}/T, and the field dependence of kappa_{0}/T mimics that in d-wave cuprate superconductors. This indicates that the superconducting gaps in KFe2As2 have nodes, likely d-wave symmetry. Such a nodal superconductivity is attributed to the antiferromagnetic spin fluctuations near the quantum critical point.

Etoposide 1.0 g/m2 or 1.5 g/m2 combined with granulocyte colony-stimulating factor for mobilization of peripheral blood stem cells in patients with malignancy: efficacy and toxicity

BACKGROUND

The purpose of this study was to observe the efficacy and toxicity of etoposide at two dose levels for peripheral blood stem cell (PBSC) mobilization and disease debulking in patients with malignancy. Simultaneously, factors affecting the yield of CD34+ cells were explored.

METHODS

Thirty-eight patients received etoposide 1.0 g/m2 (group A) or 1.5 g/m2 (group B) followed by granulocyte colony-stimulating factor (G-CSF) 300 microg/day for PBSC mobilization in a non-randomized manner. Each group had 19 patients.

RESULTS

The median number of CD34+ cells collected was 17.33 x 10(6)/kg (range 4.85-89.00 x 10(6)/kg) in group A and 26.54 x 10(6)/kg (range 1.85-108.00 x 10(6)/kg) in group B. Altogether, 34/38 (89.5%) patients obtained the target total collection of at least 4 x 10(6) CD34+ cells/kg by a single leukapheresis. Vomiting was the most common grade 3/4 non-hematologic toxicity. For 19 evaluable patients, partial response was achieved in four (21.1%), stable disease in 11 (57.8%) and progressive disease in four (21.1%) patients. All parameters between the two groups did not reach a significant level. With multivariate analysis, the most predictive factor for CD34+ yield of the first leukapheresis was the percentage of CD34+ CD38(-) cells in peripheral blood.

CONCLUSION

These results indicate that etoposide combined with G-CSF is an effective and tolerable regimen for PBSC mobilization, given at a dose of either 1.0 g/m2 or 1.5 g/m2.

Metal to insulator transition in epitaxial graphene induced by molecular doping

The capability to control the type and amount of charge carriers in a material and, in the extreme case, the transition from metal to insulator, is one of the key challenges of modern electronics. By employing angle-resolved photoemission spectroscopy we find that a reversible metal to insulator transition and a fine-tuning of the charge carriers from electrons to holes can be achieved in epitaxial bilayer and single layer graphene by molecular doping. The effects of electron screening and disorder are also discussed. These results demonstrate that epitaxial graphene is suitable for electronics applications, as well as provide new opportunities for studying the hole doping regime of the Dirac cone in graphene.

NS-398 enhances the efficacy of gemcitabine against lung adenocarcinoma through up-regulation of p21WAF1 and p27KIP1 protein

Gemcitabine is a chemotherapeutic drug widely used in the treatment of non-small cell lung carcinoma, especially in advanced lung adenocarcinoma. However, many patients with advanced lung adenocarcinoma show a resistance to gemcitabine. Overexpression of COX-2 has been found in human non-small cell lung cancer tissues and itA s cell lines. Evidences show that COX-2 is involved in drug resistance of tumor. However, It is unknown whether COX-2 inhibitor can augment the efficacy of gemcitabine against lung adenocarcinoma. In this study, A549 cells were treated with gemcitabine and/or NS-398. The cell viability was examined by MTT assay. The cell cycle distribution and apoptotic ratio were tested by flow cytometry. The levels of p21WAF1, p27KIP1, p16INK4a and p15INK4b expression were detected by western blotting. After the cells were treated with gemcitabine along with NS-398, more cells were arrested in G1 phase and went to apoptosis. The levels of p21WAF1 and p27KIP1 protein were elevated, while the levels of p16INK4a and p15INK4b protein were not changed. It can be concluded that NS-398 enhances the efficacy of gemcitabine against lung adenocarcinoma and the efficacy is associated with up-regulation of p21WAF1 and p27KIP1protein.

Substrate-induced bandgap opening in epitaxial graphene

Graphene has shown great application potential as the host material for next-generation electronic devices. However, despite its intriguing properties, one of the biggest hurdles for graphene to be useful as an electronic material is the lack of an energy gap in its electronic spectra. This, for example, prevents the use of graphene in making transistors. Although several proposals have been made to open a gap in graphene's electronic spectra, they all require complex engineering of the graphene layer. Here, we show that when graphene is epitaxially grown on SiC substrate, a gap of approximately 0.26 eV is produced. This gap decreases as the sample thickness increases and eventually approaches zero when the number of layers exceeds four. We propose that the origin of this gap is the breaking of sublattice symmetry owing to the graphene-substrate interaction. We believe that our results highlight a promising direction for bandgap engineering of graphene.

Revealing charge density wave formation in the LaTe2 system by angle resolved photoemission spectroscopy

We present the first direct study of charge density wave (CDW) formation in quasi-2D single layer LaTe2 using high-resolution angle resolved photoemission spectroscopy and low energy electron diffraction. CDW formation is driven by Fermi surface (FS) nesting, however, characterized by a surprisingly smaller gap ( approximately 50 meV) than seen in the double layer RTe2 compounds, extending over the entire FS. This establishes LaTe2 as the first reported semiconducting 2D CDW system where the CDW phase is FS nesting driven. In addition, the layer dependence of this phase in the tellurides and the possible transition from a stripe to a checkerboard phase is discussed.

Universal high energy anomaly in the angle-resolved photoemission spectra of high temperature superconductors: possible evidence of spinon and holon branches

A universal high energy anomaly in the single particle spectral function is reported in three different families of high temperature superconductors by using angle-resolved photoemission spectroscopy. As we follow the dispersing peak of the spectral function from the Fermi energy to the valence band complex, we find dispersion anomalies marked by two distinctive high energy scales, E1 approximately 0.38 eV and E2 approximately 0.8 eV. E1 marks the energy above which the dispersion splits into two branches. One is a continuation of the near parabolic dispersion, albeit with reduced spectral weight, and reaches the bottom of the band at the Gamma point at approximately 0.5 eV. The other is given by a peak in the momentum space, nearly independent of energy between E1 and E2. Above E2, a bandlike dispersion reemerges. We conjecture that these two energies mark the disintegration of the low-energy quasiparticles into a spinon and holon branch in the high Tc cuprates.

Strong and complex electron-lattice correlation in optimally doped Bi2Sr2CaCu2O8+delta

We discuss the nature of electron-lattice interaction in optimally doped Bi_{2}Sr_{2}CaCu_{2}O_{8+delta} samples, using the isotope effect (IE) in angle resolved photoemission spectroscopy (ARPES) data. The IE in the ARPES linewidth and the IE in the ARPES dispersion are both quite large, implying a strong electron-lattice correlation. The strength of the electron-lattice interaction is "intermediate," i.e., stronger than the Migdal-Eliashberg regime but weaker than the small polaron regime, requiring a more general picture of the ARPES kink than the commonly used Migdal-Eliashberg picture. The two IEs also imply a complex interaction, due to their strong momentum dependence and their differing sign behaviors. In sum, we propose an intermediate-strength coupling of electrons to localized lattice vibrations via charge density fluctuations.

Elastic scattering susceptibility of the high temperature superconductor Bi2Sr2CaCu2O(8+delta): a comparison between real and momentum space photoemission spectroscopies

The joint density of states of Bi2Sr2CaCu2O(8+delta) is calculated by evaluating the autocorrelation of the single particle spectral function A(k, omega) measured from angle resolved photoemission spectroscopy (ARPES). These results are compared with Fourier transformed (FT) conductance modulations measured by scanning tunneling microscopy (STM). Good agreement between the two experimental probes is found for two different doping values examined. In addition, by comparing the FT-STM results to the autocorrelated ARPES spectra with different photon polarization, new insight on the form of the STM matrix elements is obtained. This shines new light on unsolved mysteries in the tunneling data.

Morphological brain changes associated with Schneider's first-rank symptoms in schizophrenia: a MRI study

BACKGROUND

Schneider's first-rank symptoms involve an alienated feature of the sense of one's own mental or physical activity. To clarify the brain morphological basis for the production of these symptoms, volumes of the frontal and medial temporal regions and their clinical correlates were examined in patients with schizophrenia.

METHOD

Twenty-two patients with schizophrenia and 44 age- and gender-matched healthy control subjects were included. All patients were in their psychotic episodes with definite Schneiderian symptoms, rated by using the Scale for Assessment of Positive Symptoms. Volumetric measurements of high-resolution magnetic resonance imaging were performed in the prefrontal area, cingulate gyrus, and precentral gyrus, and the medial temporal structures such as the amygdala, hippocampus, and parahippocampal gyrus.

RESULTS

Patients had significantly decreased volumes in the cingulate gray matter and the amygdala compared to controls. In the patient group, Schneiderian symptom severity showed significant inverse correlations with volumes of the right posterior cingulate gray matter and of the left anterior parahippocampal gyrus.

CONCLUSIONS

Schneiderian symptoms may be associated with morphological abnormalities in the limbic-paralimbic regions such as the cingulate gyrus and parahippocampal gyrus, which possibly serve the self-monitoring function and the coherent storage and reactivation of information.

An unusual isotope effect in a high-transition-temperature superconductor

In conventional superconductors, the electron pairing that allows superconductivity is caused by exchange of virtual phonons, which are quanta of lattice vibration. For high-transition-temperature (high-T(c)) superconductors, it is far from clear that phonons are involved in the pairing at all. For example, the negligible change in T(c) of optimally doped Bi2Sr2CaCu2O8+delta (Bi2212; ref. 1) upon oxygen isotope substitution (16O --> 18O leads to T(c) decreasing from 92 to 91 K) has often been taken to mean that phonons play an insignificant role in this material. Here we provide a detailed comparison of the electron dynamics of Bi2212 samples containing different oxygen isotopes, using angle-resolved photoemission spectroscopy. Our data show definite and strong isotope effects. Surprisingly, the effects mainly appear in broad high-energy humps, commonly referred to as 'incoherent peaks'. As a function of temperature and electron momentum, the magnitude of the isotope effect closely correlates with the superconducting gap--that is, the pair binding energy. We suggest that these results can be explained in a dynamic spin-Peierls picture, where the singlet pairing of electrons and the electron-lattice coupling mutually enhance each other.

Complete genome analysis of the mandarin fish infectious spleen and kidney necrosis iridovirus

The nucleotide sequence of the infectious spleen and kidney necrosis virus (ISKNV) genome was determined and found to comprise 111,362 bp with a G+C content of 54.78%. It contained 124 potential open reading frames (ORFs) with coding capacities ranging from 40 to 1208 amino acids. The analysis of the amino acid sequences deduced from the individual ORFs revealed that 35 of the 124 potential gene products of ISKNV show significant homology to functionally characterized proteins of other species. Some of the putative gene products of ISKNV showed significant homologies to proteins in the GenBank/EMBL/DDBJ databases including enzymes and structural proteins involved in virus replication, transcription, protein modification, and virus-host interaction. In addition, one major repeated sequence showing significant homology to the Red Sea bream iridovirus (RSIV) genome was identified. Based on the information obtained from biological properties (including histopathology, tissue tropisms, natural host range, and geographic distribution), physiochemical and physical properties, and genome analysis, we suggest that ISKNV, RSIV, sea bass iridovirus, grouper iridovirus, and African lampeye iridovirus may belong to a new genus of the Iridoviridae family and are tentatively referred to as cell hypertrophy iridoviruses.

Serotonin(2) receptors mediate respiratory recovery after cervical spinal cord hemisection in adult rats

The aim of the present study was to specifically investigate the involvement of serotonin [5-hydroxytryptamine (5-HT(2))] receptors in 5-HT-mediated respiratory recovery after cervical hemisection. Experiments were conducted on C(2) spinal cord-hemisected, anesthetized (chloral hydrate, 400 mg/kg ip), vagotomized, pancuronium- paralyzed, and artificially ventilated female Sprague-Dawley rats in which CO(2) levels were monitored and maintained. Twenty-four hours after spinal hemisection, the ipsilateral phrenic nerve displayed no respiratory-related activity indicative of a functionally complete hemisection. Intravenous administration of the 5-HT(2A/2C)-receptor agonist (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride (DOI) induced respiratory-related activity in the phrenic nerve ipsilateral to hemisection under conditions in which CO(2) was maintained at constant levels and augmented the activity induced under conditions of hypercapnia. The effects of DOI were found to be dose dependent, and the recovery of activity could be maintained for up to 2 h after a single injection. DOI-induced recovery was attenuated by the 5-HT(2)-receptor antagonist ketanserin but not with the 5-HT(2C)-receptor antagonist RS-102221, suggesting that 5-HT(2A) and not necessarily 5-HT(2C) receptors may be involved in the induction of respiratory recovery after cervical spinal cord injury.

Activation of a latent respiratory motor pathway by stimulation of neurons in the medullary chemoreceptor area of the rat

Previous studies have demonstrated that during respiratory stress (hypercapnia and hypoxia), a latent crossed respiratory pathway can be activated to produce hemidiaphragm recovery following an ipsilateral C2 spinal cord hemisection. The present study investigates the effects of ventral medullary chemoreceptor area stimulation by microinjection of (1S,3R)-aminocyclopentanedicarboxylic acid (ACPD), a glutamate metabotropic receptor agonist, on activating the latent pathway following left C2 spinal cord hemisection in rats in which end-tidal CO2 was maintained at a constant level. Experiments were conducted on anesthetized, vagotomized, paralyzed, and artificially ventilated rats in which phrenic nerve activity was recorded bilaterally. Before drug injection, the phrenic nerve contralateral to hemisection showed vigorous respiratory-related activity, but the phrenic nerve ipsilateral to hemisection showed no discernible respiratory-related activity. ACPD (1-100 nl, 1 mM) was injected directly into the region of the retrotrapezoid nucleus (RTN), a known medullary chemoreceptor area. Microinjection of ACPD into the right RTN increased respiratory-related activity in the right phrenic nerve (contralateral to hemisection). ACPD (>5 nl, 1 mM) microinjection also significantly induced respiratory recovery in the phrenic nerve ipsilateral to hemisection in a dose-dependent manner. The present study indicates that respiratory recovery can be achieved by stimulation of respiratory circuitry without increasing CO2 levels.

Delivery of glucocorticoid conjugate in rat gastrointestinal tract and its treatment for ulcerative colitis

AIM

To evaluate colonic delivery and therapeutic effect of the newly synthesized dexamethasone (DX)-dextran (500 000) conjugate (DXD50) in the rat.

METHODS

The amount of dexamethasone was measured in the contents from different parts of rat gastrointestinal tract and in plasma after ig conjugate. Therapeutic effect of conjugate and DX was tested in trinitrobenzenesulfonic acid-induced colitis in rat. Repair of colitis was assessed by measuring colonic ulceration area, colon weight, and colonic myeloperoxidase (MPO) activity. Systemic immunosuppression of DX was evaluated with weight of thymus and spleen and lymphocyte count in peripheral blood from rat with ulcerative colitis.

RESULTS

Dexamethasone released from conjugate was mainly distributed in contents of cecum and colon. When DXD50 and DX 0.25 micromol . kg-1 . d-1 were used ig to treat ulcerative colitis in rat, the ulcerative area of colon was reduced by 55.6 % and 33.3 %, respectively whereas colon weight was reduced by 17.9 % and 2.6 %, respectively. The conjugate had no effect on lymphocyte count in peripheral blood, spleen weight, and thymus weight of rat which could be reduced markedly by the same dose of DX (P < 0.05 vs control).

CONCLUSION

DXD50, which could specifically deliver DX to large intestine, is a promising agent in the treatment of human inflammatory bowel disease.

Distribution of Serotonin 2A and 2C Receptor mRNA Expression in the Cervical Ventral Horn and Phrenic Motoneurons Following Spinal Cord Hemisection

Cervical spinal cord injury leads to a disruption of bulbospinal innervation from medullary respiratory centers to phrenic motoneurons. Animal models utilizing cervical hemisection result in inhibition of ipsilateral phrenic nerve activity, leading to paralysis of the hemidiaphragm. We have previously demonstrated a role for serotonin (5-HT) as one potential modulator of respiratory recovery following cervical hemisection, a mechanism that likely occurs via 5-HT2A and/or 5-HT2C receptors. The present study was designed to specifically examine if 5-HT2A and/or 5-HT2C receptors are colocalized with phrenic motoneurons in both intact and spinal-hemisected rats. Adult female rats (250-350 g; n = 6 per group) received a left cervical (C2) hemisection and were injected with the fluorescent retrograde neuronal tracer Fluorogold into the left hemidiaphragm. Twenty-four hours later, animals were killed and spinal cords processed for in situ hybridization and immunohistochemistry. Using (35)S-labeled cRNA probes, cervical spinal cords were probed for 5-HT2A and 5-HT2C receptor mRNA expression and double-labeled using an antibody to Fluorogold to detect phrenic motoneurons. Expression of both 5-HT2A and 5-HT2C receptor mRNA was detected in motoneurons of the cervical ventral horn. Despite positive expression of both 5-HT2A and 5-HT2C receptor mRNA-hybridization signal over phrenic motoneurons, only 5-HT2A silver grains achieved a signal-to-noise ratio representative of colocalization. 5-HT2A mRNA levels in identified phrenic motoneurons were not significantly altered following cervical hemisection compared to sham-operated controls. Selective colocalization of 5-HT2A receptor mRNA with phrenic motoneurons may have implications for recently observed 5-HT2A receptor-mediated regulation of respiratory activity and/or recovery in both intact and injury-compromised states.

[Pharmacokinetics of site-specific delivery of dexamethasone-dextran prodrug in rat gastrointestinal tract]

AIM

To explore whether dexamethasone-dextran (260,000) has the characteristics of site-specific delivery in rat gastrointestinal tract.

METHODS

Dexamethasone prodrug and dexamethasone were administered to rat ig at the dose of 5 mumol.kg-1. The distribution of dexamethasone in the contents and mucosa of different parts of the rat GI tract at different time intervals and its concentration in plasma were determined by HPLC.

RESULTS

Dexamethasone was mainly released in the cecum and colon contents and mucosa after oral administration of dexamethasone prodrug. The absorption was reduced significantly. The peak time of the drug in plasma was 8.1 h, and the peak concentration was 32 micrograms.L-1. However, free dexamethasone was found mainly in the contents and mucosa of the stomach, proximal and distal small intestine. The peak time of the drug in plasma was 2.2 h, and the peak concentration was 2120 micrograms.L-1.

CONCLUSION

Dexamethasone can be specifically delivered to the large intestine by using dexamethasone-dextran (260,000). It appears that the prodrug has a potential in the treatment of inflammatory bowel disease.

Regional-dependent intestinal absorption and meal composition effects on systemic availability of LY303366, a lipopeptide antifungal agent, in dogs

Low oral bioavailability and a negative meal effect on drug plasma levels motivated studies on formulation and meal composition effects on the absorption of LY303366, a poorly water-soluble, semisynthetic, cyclic peptide antifungal drug. Solid drug particle size and meal composition studies were evaluated in beagle dogs. Canine regional absorption studies were also carried out utilizing surgically implanted intestinal access ports, and Caco-2 studies were performed to evaluate drug candidate intestinal permeability. Particle size and Caco-2 data indicate that drug permeability limitations to absorption are more important than dissolution rate limits. Caco-2 cell-associated LY303366 approached 10% of incubation concentration that is in the range of the oral bioavailability of the drug. Canine regional absorption studies showed that the extent of LY303366 absorption following duodenal administration was similar to that following oral administration. Significantly lower drug plasma levels were obtained following administration through a colonic access port, a result consistent with poor membrane permeation. Administration of drug with meals of mixed composition, as well as simple fat and protein meals, resulted in significant reductions in AUC(0-48h) compared with results from fasted dogs. In contrast, carbohydrate meals did not reduce drug plasma levels compared to controls. Intravenous pretreatment with devazepide, a cholecystokinin (CCK) antagonist that blocks canine biliary secretion, did not reverse the negative effect of the fat meal on LY303366. Taken together, the results from the present study suggest that membrane-permeability-limited absorption is the cause of the observed regionally dependent absorption of LY303366 in the dog and that the observed negative meal effects depend on composition but are independent of biliary secretion.

5-Hydroxytryptophan-induced respiratory recovery after cervical spinal cord hemisection in rats

The present study investigates the role of serotonin in respiratory recovery after spinal cord injury. Experiments were conducted on C(2) spinal cord hemisected, anesthetized, vagotomized, paralyzed, and artificially ventilated rats in which end-tidal CO(2) was monitored and maintained. Before drug administration, the phrenic nerve ipsilateral to hemisection showed no respiratory-related activity due to the disruption of the descending bulbospinal respiratory pathways by spinal cord hemisection. 5-Hydroxytryptophan (5-HTP), a serotonin precursor, was administrated intravenously. 5-HTP induced time- and dose-dependent increases in respiratory recovery in the phrenic nerve ipsilateral to hemisection. Although the 5-HTP-induced recovery was initially accompanied by an increase in activity in the contralateral phrenic nerve, suggesting an increase in descending respiratory drive, the recovery persisted well after activity in the contralateral nerve returned to predrug levels. 5-HTP-induced effects were reversed by a serotonin receptor antagonist, methysergide. Because experiments were conducted on animals subjected to C(2) spinal cord hemisection, the recovery was most likely mediated by the activation of a latent respiratory pathway spared by the spinal cord injury. The results suggest that serotonin is an important neuromodulator in the unmasking of the latent respiratory pathway after spinal cord injury. In addition, the results also suggest that the maintenance of 5-HTP-induced respiratory recovery may not require a continuous enhancement of central respiratory drive.