[Effect of closed extension tube on preventing airway leakage during artificial airway clearance]

Objective: To explore the role of closed extension tube in preventing airway leakage during artificial airway clearance. Methods: The test lung was connected with a ventilator for mechanical ventilation. The pressure parameters were set as 16/5, 20/6, 24/7, 28/8, 32/9 and 36/10 cmH₂O(1 cmH₂O=0.098 kPa), respectively. The circuit was connected with an open extension tube or a closed extension tube. The ventilator was set with different pressure parameters to observe the changes of airway pressure and tidal volume during airway clearance. Results: (1) The pressure parameters were set as 16/5, 20/6, 24/7, 28/8, 32/9 and 36/10 cmH₂O, and the airway pressures (in cmH₂O) of circuit connected with open extension tube were (15.94±0.27)/(4.81±0.04), (20.09±0.23)/(6.05±0.16), (23.89±0.41)/(6.94±0.06), (27.90±0.22)/(7.71±0.18), (31.92±0.13)/(8.74±0.12)and(35.65±0.31)/(9.72±0.07), respectively.Under the same ventilator pressure parameters, the airway pressures (in cmH₂O) of circuit connected with close extension tube were (16.36±0.06)/(4.85±0.04), (20.54±0.26)/(6.44±0.12), (24.36±0.24)/(7.01±0.33), (28.69±0.25)/(8.07±0.08), (32.97±0.33)/(8.93±0.09), (37.34±0.29)/(9.75±0.08), respectively. The airway pressure of circuit connected with open extension tube was lower than that connected with closed extension tube(P<0.05);with the increase of the pressure setting of the ventilator, the difference of the airway pressure between the two extended tubes gradually increased. When the maximum inspiratory pressure of the ventilator was set 36 cmH₂O, the difference reached 1.69 cmH₂O. (2) The airway pressures (in cmH₂O) dropped from (15.94±0.27)/(4.81±0.04), (20.09±0.23)/(6.05±0.16), (23.89±0.41)/(6.94±0.06), (27.90±0.22)/(7.71±0.18), (31.92±0.13)/(8.74±0.12), (35.65±0.31)/(9.72±0.07) to (13.42±0.4)/(3.15±0.14), (16.81±0.6)/(4.30±0.14), (20.22±0.5)/(5.48±0.45), (23.73±1.4)/(6.25±0.22), (24.78±0.7)/(7.13±0.21), (20.83±0.4)/(6.61±0.19)when the suction port of the open extension tube was opened (P<0.05);and the tidal volume (in L) also decreased from 0.328±0.004, 0.580±0.012, 0.621±0.003, 0.626±0.003, 0.615±0.003, 0.603±0.002 to 0.272±0.008, 0.416±0.051, 0.487±0.047, 0.396±0.116, 0.507±0.022, 0.508±0.079, respectively (P<0.05). The decrease of airway pressure and tidal volume gradually increased with the increase of ventilator setting pressure. When the ventilator setting parameter was 36/10 cmH₂O, the decrease of airway inspiratory pressure was (14.82±0.51) cmH₂O and the maximum reduction of tidal volume was (0.164±0.021)L. (3)The airway pressure (in cmH₂O) was increased to(15.70±0.23)/(4.80±0.33), (19.01±0.81)/(5.71±0.34), (22.27±0.62)/(6.85±0.44), (25.35±2.09)/(7.94±0.16), (28.38±0.46)/(8.96±0.23), (33.34±0.71)/(9.71±0.25) when the suction tube was inserted from the suction port of the open extension tube in the open state, and the tidal volume (in L) was increased to 0.340±0.016, 0.563±0.020, 0.571±0.030, 0.556±0.026, 0.514±0.021, 0.512±0.031 as well.The airway pressure and tidal volume of the ventilation circuit were higher than those in the open state, but still lower than those in the closed state. Compared with the closed state of the suction port, the maximum pressure drop and tidal volume decrease were (3.53±0.46) cmH₂O and (0.101±0.011) L, respectively. (4) The pressure of the ventilator was set between 16/5 cmH₂O to 36/10 cmH₂O. The airway pressure (in cmH₂O) was decreased from (16.26±0.04)/(4.85±0.04), (20.74±0.15)/(6.42±0.11), (25.09±0.31)/(7.10±0.13), (29.38±0.24)/(8.17±0.09), (33.80±0.16)/(9.02±0.17), (37.89±0.19)/(9.83±0.07) to(16.36±0.06)/(4.85±0.04), (20.54±0.26)/(6.44±0.12), (24.36±0.24)/(7.01±0.33), (28.69±0.25)/(8.07±0.08), (32.97±0.33)/(8.93±0.09), (37.34±0.29)/(9.75±0.08), respectively during the insertion of the suction tube from the suction port of the closed extension tube, and the tidal volume (in L) was decreased from0.361±0.005, 0.592±0.003, 0.631±0.001, 0.642±0.007, 0.633±0.007, 0.626±0.08 to 0.335±0.005, 0.588±0.008, 0.631±0.002, 0.638±0.004, 0.628±0.004, 0.618±0.005.The maximum pressure change of the ventilation circuit was (0.83±0.27) cm H₂O and the maximum tidal volume change was (0.008±0.006)L. The changes of airway pressure and tidal volume were significantly lower than those of ventilation circuit connected with open extension tube under the same pressure parameters. Conclusion: The connection of closed extension tube in mechanical ventilation circuit can reduce the airway leakage during artificial airway clearance, which is worthy of clinical recommendation.

Effectiveness and postoperative rehabilitation of one-stage combined anterior-posterior surgery for severe thoracolumbar fractures with spinal cord injury

BACKGROUND

Thoracolumbar fractures are generally combined with spinal cord injury to varying degrees, which may cause deterioration of the patients' condition and increase the difficulty of clinical treatment. At present, anterior or combined anterior-posterior surgery is preferred for severe thoracolumbar fractures.

AIM

To investigate the effectiveness and postoperative rehabilitation of one-stage combined anterior-posterior surgery for severe thoracolumbar fractures with spinal cord injury.

METHODS

One-hundred-and-twenty patients who received surgery for severe thoracolumbar fractures with spinal cord injury at our hospital from February 2018 to February 2020 were randomly enrolled. They were randomly divided into group 1 (one-stage combined anterior-posterior surgery, n = 60) and group 2 (one-stage anterior-approach surgery, n = 60). Treatment efficacy was compared between the two groups.

RESULTS

Blood loss was greater and the operation time was longer in group 1 than in group 2, and the differences were statistically significant (P < 0.05). Incision length, intraoperative X-rays, and length of hospital stay were not significantly different between the two groups (P > 0.05). Preoperative function of the affected vertebrae was not significantly different between the two groups (P > 0.05). In each group, the patients showed significant improvement after surgery. The anterior vertebral height ratio and the posterior vertebral height ratio in group 1 after surgery were significantly higher than those in group 2. The Cobb angle after surgery was significantly lower in group 1 than in group 2 (P < 0.05). The canal-occupying ratio of the affected vertebrae was not significantly different between the two groups (P > 0.05). Before surgery, there was no significant difference in the quality of life scores between the two groups (P > 0.05). The above indicators were significantly improved after surgery compared with before surgery in each group. In addition, these indicators were markedly better in group 1 than in group 2 after surgery (P < 0.05 for each).

CONCLUSION

One-stage combined anterior-posterior surgery effectively improves the function of the affected vertebrae and the life quality of patients with severe thoracolumbar fractures and spinal cord injury. This surgical approach is worthy of popularization in clinical use.

Outcomes of cervical degenerative disc disease treated by anterior cervical discectomy and fusion with self-locking fusion cage

BACKGROUND

Cervical degenerative disc (CDD) disease is a common type of spondylosis. Although anterior cervical discectomy and fusion (ACDF) is the preferred treatment for CDD disease, internal fixation with a titanium plate may cause various complications. The invention of the ACDF with a self-locking fusion cage (ROI-C) has effectively decreased the incidence of postoperative complications.

AIM

To observe the outcomes of CDD disease treated by ACDF with a ROI-C.

METHODS

Ninety patients with CDD disease treated at our hospital from March 2019 to March 2021 were included. They were divided into two groups (control group and observation group, n = 45 in each) using a random number table. Patients in the control group received ACDF plus internal fixation with a titanium plate. Those in the observation group received ACDF + ROI-C placement. The two groups of patients were compared in terms of surgical parameters, pain, cervical spine function, range of motion, and complications.

RESULTS

The two groups of patients showed no significant differences in surgical time, blood loss, drainage volume, and length of hospital stay (P > 0.05). No significant differences in the visual analogue scale (VAS), Japanese Orthopedic Association (JOA), and neck disability index (NDI) scores were observed between the two groups before surgery (P > 0.05). The VAS and NDI scores in the observation group were considerably lower than those in the control group after surgery; however, the JOA scores in the observation group were significantly higher than those in the control group (P < 0.05). No significant differences were observed in cervical disc height and the range of motion of the superior or inferior adjacent vertebrae between the two groups before surgery (P > 0.05). The disc height in the observation group was larger than that in the control group after surgery. The range of motion of both the superior and inferior adjacent vertebrae was significantly smaller in the observation group than in the control group (P < 0.05). The incidence of complications was only 2.22% in the observation group compared to 15.56% in the control group, and the difference was statistically significant (P < 0.05).

CONCLUSION

Cervical spine function restoration was better with ROI-C with internal fixation in ACDF than with conventional titanium plates in ACDF for CDD disease.

[Challenges and countermeasures in the treatment of luminal breast cancer]

Luminal breast cancer is the most common subtype of breast cancer, representing more than 60% of all breast cancers. Endocrine resistance and late recurrence are two challenges in the treatment of luminal breast cancer. To overcome endocrine resistance in multiple levels, high-dose-fulvestrant can inhibit estrogen-receptor (ER)-dependent pathways, while targeted drugs can block ER-independent pathways.To reduce the risk of late recurrence in luminal breast cancer, recurrence prediction model should be formed. For patients with high risk of late recurrence, extended endocrine therapy, combination of ovarian function suppression (OFS) or vascular endothelial growth factor (VEGF) inhibitor could be utilized. Based on the challenges of the treatment, scientific research achievements can be used in clinical practice, and finally optimize the clinical treatment strategy.

[The Role of Soluble HLA-G in the Vertical Transmission of Toxoplasma gondii]

Soluble human leukocyte antigen G (sHLA-G) plays a key role in pregnancy through interaction with decidual natural killer (dNK) cell inhibitory receptors at the maternal-fetal interface. To demonstrate the possible role of sHLA-G during the pregnancy with Toxoplasma gondii infection, we compared the concentration of a murine functional homolog of sHLA-G, Qa-2, in T. gondii infected and non-infected pregnant C57BL/6 mice, and that of sHLA-G in BeWo culture supernatant. In addition, the levels of KIR2DL4 expressed on human dNK cells and NKG2A in pregnant mice were evaluated. We showed that T. gondii infection result in significant increase in the level of Qa-2 and NKG2A in pregnant mice. sHLA-G and KIR2DL4 in human samples were also significantly upregulated under the condition of T. gondii infection. The further treatment with sHLA-G antibody could reduce the expression level of KIR2DL4 which was upregulated by T. gondii infection. In summary, sHLA-G could upregulate the expression level of KIR2DL4 which lead to excessive immunological tolerance, and further contributed to T. gondii immunity escaping and affecting fetus via vertical transmission which may lead to adverse outcomes.

[Endoscopic reconstruction of the posterior nares for the treatment of 46 children with congenital posterior atresia]

Objective:The aim of this study is to explore the influencing factors of the posterior nostril re-atresia by analyzing the clinical data of endoscopic posterior nostril reconstruction in the children with posterior nostril atresia. Method:Retrospectively reviewed 46 pediatric patients with congenital choanal atresia who underwent endoscopic posterior nostril reconstruction. Randomly divided the cases into the atresia group（19 cases） and the non-atresia group（27 cases） according to whether the new posterior nostril re-atresia again. Compared the difference of the clinical data between the two groups and observed the influencing factors of the posterior nostril re-atresia. Result:The gender, age, unilateral/bilateral atresia or U-shaped stent had no significant differences between the two groups. However, the nature of the atresia and granulation hyperplasia were significant differences between the two groups. Further analysis of the nature of the atresia revealed osseous atresia had higher rate of re-atresia than membranous atresia. Conclusion:Endoscopic posterior nostril reconstruction was a good method for the treatment of the children with congenital posterior nostril atresia. However, the children with osseous atresia had higher re-atresia rate.

[Regulation of m^(6)A RNA Methylation and Its Effect on Myogenic Differentiation in Murine Myoblasts]

N^(6)-methyladenosine (m^(6)A) has been identified as a conserved epitranscriptomic modification of eukaryotic mRNAs, and plays important biological roles in the regulation of cellular metabolic processes. However, its role in myogenic differentiation is unclear. Here, we altered the m^(6)A RNA methylation level by overexpression of METTL3, and explored the effect of m^(6)A RNA methylation on myogenic differentiation of murine myoblasts in vitro. The m6A RNA methylation level is regulated by exogenous methylation inhibitor cycloleucine (Cyc) and methyl donor betaine (Bet). Therefore, chemical reagents of Cyc and Bet were used to test the regulatory effect of m^(6)A RNA methylation on myogenic differentiation. Results showed that METTL3 and Bet positively regulated the m^(6)A RNA methylation levels, and Cyc negatively regulated m^(6)A RNA methylation levels. In addition, m^(6)A methylation positively regulated myogenic differentiation in murine myoblasts. These findings provide insight in the mechanisms underlying the effect of m^(6)A RNA methylation on myogenesis.

[MiR-222-3р Regulates the Proliferation and Differentiation of C2C12 Myoblasts by Targeting BTG2]

MiR-222-3р has been implicated in tumor cell proliferation and has an important role in the differentiation and maturation of myogenic cells. However, its role in skeletal myoblast proliferation is still unclear. In this study, we found that miR-222-3р expression increases initially and then decreases during C2C12 myoblast proliferation. Using synthetic miRNA mimics and inhibitors in gain- or loss-of-function experiments, we snowed that miR-222-3р overexpression in C2C12 cells promotes myoblast proliferation and represses myofiber formation, while miR-222-3р downregulation has the opposite effect. Using a prediction program, BTG2 was identified as a possible target gene of miR-222-3р. During myogenesis, miR-222-3р mimics repress BTG2 expression, while miR-222-3р inhibitors promote BTG2 expression. Using dual-luciferase reporter assay, we further demonstrated that miR-222-3р specifically targets BTG2. Additionally, we show that siRNA-mediated downregulation of BTG2 expression in C2C12 myoblasts promotes the proliferation and suppresses differentiation. In conclusion, we provide a novel insight into the mechanism by which miR-222-3р regulates the proliferation and differentiation of C2C12 myoblasts by targeting BTG2. This information contributes to our understanding of the role of miRNAs in skeletal muscle development.

[Effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts]

Objective: To investigate the effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts. Methods: A small amount of normal skin donated by burn patients undergoing scar surgery was collected. Human fibroblasts were obtained by method of explant culture and then sub-cultured. The fourth passage of cells were used in the following experiments. (1) Fibroblasts were divided into normal collagen group and denatured collagen group according to the random number table, with 10 wells in each group. Fibroblasts in normal collagen group were cultured on normal collagen type Ⅰ coated coverslips. Fibroblasts in denatured collagen group were cultured on denatured type Ⅰ collagen coated coverslips. Expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemical method, and the percentage of PCNA positive cells was calculated. (2) Another batch of fibroblasts were grouped and treated as in (1), with 12 wells in each group. Proliferation activity of cells was determined with methyl-thiazolyl-tetrazolium colorimetry method. (3) Another batch of fibroblasts were grouped and treated as in (1), and the microfilament morphology of cells was observed by rhodamine-phalloidin staining. (4) Another batch of fibroblasts were grouped and treated as in (1). Expression of α smooth muscle actin (α-SMA) of cells was detected by immunohistochemical method, and expression of OB-cadherin of cells was detected by immunofluorescence method. (5) Another batch of fibroblasts were divided into normal collagen, denatured collagen, and common coverslips groups according to the random number table, with 6 wells in each group. Fibroblasts in normal collagen and denatured collagen groups were treated as in (1), while fibroblasts in common coverslips group were cultured on coverslips without collagen coating. Expressions of α-SMA and OB-cadherin of cells were determined with Western blotting. (6) Another batch of fibroblasts were grouped and treated as in (5), and then the mRNA expressions of collagen type Ⅰ, collagen type Ⅲ, and α-SMA of cells were determined with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with t test, one way analysis of variance, and least-significant difference test. Results: (1) The percentage of PCNA positive cells in denatured collagen group was (83±9)%, significantly higher than (29±9)% in normal collagen group (t=13.53, P<0.01). (2) The proliferation activity of fibroblasts in denatured collagen group was 0.32±0.06, significantly higher than 0.25±0.05 in normal collagen group (t=3.06, P<0.01). (3) The microfilament of fibroblasts in normal collagen group was arranged vertically and in parallel way, paralleling the long axis of cells. The microfilament of fibroblasts in denatured collagen group was denser and thicker. (4) Most fibroblasts in normal collagen group showed long shuttle-like shape typically. Morphology of fibroblasts in denatured collagen group changed, and cells were obviously spreading. Expressions of α-SMA and OB-cadherin of fibroblasts in denatured collagen group were stronger than those in normal collagen group. (5) Expressions of α-SMA of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 1.69±0.41, 0.89±0.27, and 1.46±0.42. Expression of α-SMA of fibroblasts in denatured collagen group was significantly higher than that in normal collagen group (P<0.01). Expressions of OB-cadherin of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 5.17±0.28, 2.21±0.10, and 4.01±0.56. Expression of OB-cadherin of fibroblasts in denatured group was significantly higher than that in normal collagen group (P<0.01). (6) There was no significant difference in mRNA expression of collagen type Ⅰ of fibroblasts in denatured collagen, normal collagen, and common coverslips groups (F=2.71, P>0.05). The mRNA expressions of collagen type Ⅲ and α-SMA of fibroblasts in normal collagen group were significantly lower than those in denatured collagen group (P<0.01). Conclusions: Denatured collagen type Ⅰ may influence the activity of fibroblasts, thus inducing fibroblasts differentiating into myofibroblasts.

Lauric Acid Is an Inhibitor of Clostridium difficile Growth in Vitro and Reduces Inflammation in a Mouse Infection Model

Clostridium difficile is a Gram-positive, spore-forming anaerobic human gastrointestinal pathogen. C. difficile infection (CDI) is a major health concern worldwide, with symptoms ranging from diarrhea to pseudomembranous colitis, toxic megacolon, sepsis, and death. CDI onset and progression are mostly caused by intestinal dysbiosis and exposure to C. difficile spores. Current treatment strategies include antibiotics; however, antibiotic use is often associated with high recurrence rates and an increased risk of antibiotic resistance. Medium-chain fatty acids (MCFAs) have been revealed to inhibit the growth of multiple human bacterial pathogens. Components of coconut oil, which include lauric acid, have been revealed to inhibit C. difficile growth in vitro. In this study, we demonstrated that lauric acid exhibits potent antimicrobial activities against multiple toxigenic C. difficile isolates in vitro. The inhibitory effect of lauric acid is partly due to reactive oxygen species (ROS) generation and cell membrane damage. The administration of lauric acid considerably reduced biofilm formation and preformed biofilms in a dose-dependent manner. Importantly, in a mouse infection model, lauric acid pretreatment reduced CDI symptoms and proinflammatory cytokine production. Our combined results suggest that the naturally occurring MCFA lauric acid is a novel C. difficile inhibitor and is useful in the development of an alternative or adjunctive treatment for CDI.

Retrospective analysis of 20 cases of refractory Hodgkin's lymphoma

We investigate the clinical characteristics, prognosis and treatment of relapsed and refractory Hodgkin's lymphoma. Twenty patients with relapsed and refractory Hodgkin lymphoma were treated by chemotherapy or autologous stem cell transplantation in our hospital from April 2006 to August 2012. The retrospective analysis of the records from the 20 patients reflected both 5-year overall survival (OS) and progression-free survival (PFS). The overall effectiveness was 80% for the 20 patients. The 5-year overall survival rate and 5-year progression-free survival rate were 73.5% and 62.7%, respectively. Therefore, comprehensive treatment should be actively utilized in the case of invalid second-line regimen for the refractory HL patients.

Determination of eddy current response with magnetic measurements

Accurate mutual inductances between magnetic diagnostics and poloidal field coils are an essential requirement for determining the poloidal flux for plasma equilibrium reconstruction. The mutual inductance calibration of the flux loops and magnetic probes requires time-varying coil currents, which also simultaneously drive eddy currents in electrically conducting structures. The eddy current-induced field appearing in the magnetic measurements can substantially increase the calibration error in the model if the eddy currents are neglected. In this paper, an expression of the magnetic diagnostic response to the coil currents is used to calibrate the mutual inductances, estimate the conductor time constant, and predict the eddy currents response. It is found that the eddy current effects in magnetic signals can be well-explained by the eddy current response determination. A set of experiments using a specially shaped saddle coil diagnostic are conducted to measure the SUNIST-like eddy current response and to examine the accuracy of this method. In shots that include plasmas, this approach can more accurately determine the plasma-related response in the magnetic signals by eliminating the field due to the eddy currents produced by the external field.

[Mass spectrometry combined with gene analysis for prenatal diagnosis of glutaric acidemia type Ⅰ]

Objective: To investigate the value of amniotic fluid metabolite detection by mass spectrometry combined with gene mutation analysis in the prenatal diagnosis of glutaric acidemia type Ⅰ (GA-Ⅰ). Method: From January 2009 to December 2016, Department of Pediatric Endocrinology and Genetic, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine carried out prenatal diagnosis for 24 cases of pregnant women with GA-Ⅰproband. 24 pregnant women without organic acidemia proband for conventional prenatal diagnosis at the same period were used as the control group. The pregnant women of the two groups had the amniocentesis at 16 to 20 weeks of gestation.The levels of glutaryl carnitine (C5DC) and octanoylcarnitine (C8) in amniotic fluid were detected by tandem mass spectrometry, and the levels of glutaric acid was determined by gas chromatography-mass spectrometry. All the amniotic fluid cells underwent GCDH gene testing. Result: A total of 4 cases of fetuses were diagnosed by gene mutation analysis combined with mass spectrometry detection, the levels of C5DC (1.58(0.89-2.85) μmol/L), C5DC/C8 (19.74(12.40-25.93))and glutaric acid (129.96 (90.09-66.02) mmol/mol Cr) were significantly higher than the upper limit of the reference, of which in one case with the proband only on mutation was detected, and in the amniotic fluid cells also only one mutation was detected, the diagnosis was made according to the significantly increased levels of amniotic fluid C5DC, C5DC/C8 and glutaric acid. Twenty cases of fetuses were identified as non-GA-Ⅰchildren, of whom in 2 cases of proband only one mutation was detected, and also in amniotic fluid cells one mutation was detected, in 2 cases the diagnosis was excluded because the normal levels of C5DC, C5DC/C8 and glutaric acid. There were 2 cases whose levels of C5DC or glutaric acid were slightly higher than the upper limit of the reference, but the diagnosis was excluded according to genetic testing. Conclusion: Prenatal diagnosis cannot be made by gene analysis when the proband mutation is not clear, and it cannot determine whether the fetus is patient when the mass spectrometry detection of amniotic fluid metabolite is mildly abnormal, while mass spectrometry detection of amniotic fluid C5DC, C5DC/C8 and glutaric acid levels combined with GCDH gene analysis can make up the deficiencies, and make the prenatal diagnosis of GA-Ⅰ more reliably.

Pseudomonas aeruginosa Ventilator-Associated Pneumonia Induces Lung Injury through TNF-α/c-Jun NH2-Terminal Kinase Pathways

Ventilator-associated pneumonia (VAP) is a common nosocomial infection among intensive care unit (ICU) patients. Pseudomonas aeruginosa (PA) is the most common multidrug-resistant Gram-negative pathogen and VAP caused by PA carries a high rate of morbidity and mortality. This study examined the molecular mechanism of PA VAP-induced lung injury. C57BL/6 wild-type (WT) mice and JNK1 knockout (JNK1^-/-) mice received mechanical ventilation (MV) for 3 h at 2 days after receiving nasal instillation of PA. The WT and JNK1^-/- mice also received MV after the induction of lung injury by instillation of supernatants from PA-stimulated alveolar macrophages (AMs). AMs isolated from WT, IκB-kinase (IKK)β^ΔMye (IKKβ was selectively deleted in macrophages), and JNK1^-/- mice were ex vivo stimulated with live PA and supernatants were collected for cytokine assay. Intranasal instillation of 10⁶ PA enhanced MV-induced NF-κB DNA binding activity in the lungs and nitrite levels in BALF. MV after PA instillation significantly increased the expression of ICAM and VCAM in the lungs and TNF-α, IL-1β, and IL-6 levels in bronchoalveolar lavage fluid (BALF) of WT mice, but not in JNK1^-/- mice. MV after supernatant instillation induced more total protein concentration in BALF and neutrophil sequestration in the lungs in WT mice than JNK1^-/- mice and cytokine assay of supernatants indicated that TNF-α is a critical regulator of PA VAP-induced lung injury. Ex vivo PA stimulation induced TNF-α production by AMs from WT as well as JNK1^-/- mice but not IKKβ^ΔMye mice. In summary, PA colonization plays an important role in PA VAP-induced lung injury through the induction of JNK1-mediated inflammation. These results suggest that the pathogenesis mechanism of PA VAP involves production of TNF-α through activation of IKK/NF-κB pathways in AMs and JNK signaling pathway in the lungs.

[Experience in children airway foreign bodies: an analysis of 220 cases]

Objective:To observe the clinical characteristics, pathogen infection and the diagnostic reliability of CT multiplanar reconstruction(CT MPR) in the children with airway foreign bodies.Method:We retrospectively reviewed 220 pediatric patients suspected with respiratory foreign bodies who were simultaneously examined by CT MPR, bronchoscopy and secretion culture.Then we summarized their characteristics from treatment process, age distribution, foreign body kinds, examination results of CT MPR, bronchoscopy and secretion culture. Result:Only 108 cases(49.09%) accepted bronchoscopy in 48 hours and the most risk age was 1 to 2 years old. We observed the commonest foreign bodies were peanuts, melon seeds and nuts. In addition, we found CT MPR was accurate in diagnostic airway foreign body with accuracy ratio was 94.09%. Furthermore, our secretion culture showed negative(64.09%) in 141 cases and positive(35.91%) in 79 patients. And the commonest pathogenic bacteria were staphylococcus aureus, streptococcus pneumoniae, haemophilus influenzae, pseudomonas aeruginosa,klebsiella pneumonia.Conclusion:Pediatric airway foreign bodies had its own clinical characteristics.When the medical units had no conditions to carry out bronchoscopy,CT MPR would be a good choice to rule out airway foreign body.Besides,most case only needed symptomatic treatment other than antibiotics after bronchoscopy.

Pseudomonas aeruginosa colonization enhances ventilator-associated pneumonia-induced lung injury

Background

Pseudomonas aeruginosa (PA) is the single-most common pathogen of ventilator-associated pneumonia (VAP). Large quantities of PA in the trachea of ventilated patients are associated with an increased risk of death. However, the role of PA colonization in PA VAP-induced lung injury remains elusive. This study examined the effect and mechanism of PA colonization in VAP-induced lung injury.

Methods

C57BL/6 wild-type (WT) and c-Jun N-terminal kinase knockout (JNK1^−/−) mice received mechanical ventilation for 3 h at 2 days after receiving nasal instillation of PA (1 × 10⁶ colony forming unit) or normal saline.

Results

Intranasal instillation of PA or mechanical ventilation induced the expression of interleukin-6 (IL-6) in the lungs. Phospho-JNK protein expression in the lungs was significantly increased in mice receiving mechanical ventilation after PA instillation as compared with those receiving ventilation alone. Mechanical ventilation after PA instillation significantly increased the expression of tumor necrosis factor-α (TNF-α), IL-1β, and macrophage inflammatory protein-2 (MIP-2) proteins; neutrophil sequestration; and TNF-α, IL-1β, and IL-6 levels in the lungs of WT mice, but not in JNK1^−/− mice.

Conclusion

PA colonization plays an important role in PA VAP-induced lung injury through the induction of JNK1-mediated inflammation. PA-induced VAP causes lung injury through JNK signaling pathway in the lungs. JNK inhibition in ICU patients with higher percentages of PA colonization may reduce VAP-induced lung injury and mortality.

[Breast cancer research in the era of precision medicine]

Precision medicine is an emerging medical strategy that takes into account individual molecular variations of disease to guide accurate prevention and treatment.Tumor molecular markers closely related to aggressive behavior and treatment response will be identified by integrating clinical information and multiple-omics, and will be verified in well-designed clinical trials. Breast cancer is a highly heterogeneous disease. Its treatment based on molecular subtyping has achieved initial success. However, drug resistance and tumor heterogeneity are still major challenges. This review will focus on the recent progress and future prospects of clinical research on breast cancer in the era of precision medicine.

Effects of muscle fiber type on glycolytic potential and meat quality traits in different Tibetan pig muscles and their association with glycolysis-related gene expression

The myosin heavy chain (MyHC) composition, glycolytic potential, mitochondrial content, and gene expression related to energy metabolism were analyzed in eight muscles from Tibetan pigs, to study how meat quality develops in different muscle tissues. The muscles were classified into three clusters, based on MyHC composition: masseter, trapezius, and latissimus dorsi as 'slow-oxidative-type'; psoas major and semimembranosus as 'intermediate-type'; and longissimus dorsi, obliquus externus abdominis, and semitendinosus as 'fast-glycolytic-type'. The 'slow-oxidative-type' muscles had the highest MyHC I and MyHC IIA content (P < 0.01); 'intermediate-type' muscles, the highest MyHC IIx content (P < 0.01); and 'fast-glycolytic-type' muscles, the highest MyHC IIb content (P < 0.01). The pH values measured in 'slow-oxidative-type' muscles were higher than those in the other clusters were; however, the color of 'fast-glycolytic-type' muscles was palest (P < 0.01). Mitochondrial content increased in the order: fast-glycolytic-type < intermediate-type < slow-oxidative-type. In the 'slow-oxidative-type' muscles, the expression levels of genes related to ATP synthesis were higher, but were lower for those related to glycogen synthesis and glycolysis. Mitochondrial content was significantly positively correlated with MyHC I content, but negatively correlated with MyHC IIb content. MyHC I and mitochondrial content were both negatively correlated with glycolytic potential. Overall, muscles used frequently in exercise had a higher proportion of type I fibers. 'Slow-oxidative-type' muscles, rich in type I fibers with higher mitochondrial and lower glycogen and glucose contents, had a higher ATP synthesis efficiency and lower glycolytic capacity, which contributed to their superior meat quality.

Creation of experimental aneurysms at a surgically created arterial confluence

OBJECTIVE

Complex vertebral confluence aneurysms remain clinically challenging despite the rapid technological advances in endovascular technology. Therefore, animal confluence aneurysm models are urgently needed for the preclinical development of related medical devices and training clinicians. This study aimed to establish canine confluence aneurysm model and evaluate hemodynamics in this model.

MATERIALS AND METHODS

According to the shape and regional blood flow of vertebrobasilar junction (VBJ) aneurysms, confluence aneurysm was introduced in 9 dogs by microsurgical technique. We partially anastomosed right common carotid artery (CCA) and left CCA (end to side anastomosis) to create inverted Y-junction of arteries and, then, sutured a harvested segment of external jugular vein to the notch of anastomosis to simulate confluence aneurysm. These animals were examined by 3D digital subtraction angiography (DSA) 4 weeks after surgery. Geometry parameters of the aneurysm, surrounding vasculature and specific double inlet profiles were analyzed by simulating computational fluid dynamics (CFD) in these animals.

RESULTS

Aneurysms were successfully established in all animals, including 8 complete and 1 partially thrombosed aneurysms. No neurological defects or death were observed. Geometric and hemodynamic parameters in these surgically introduced confluence aneurysm animals are similar to those reported for human VBJ aneurysms.

CONCLUSIONS

This study documents a protocol to successfully establish confluence aneurysm models in dogs. This model may be useful in preclinical studies targeting various complex vertebral confluence aneurysms.

Effect of asymmetrical eddy currents on magnetic diagnosis signals for equilibrium reconstruction in the Sino-UNIted Spherical Tokamak

The vacuum vessel of Sino-UNIted Spherical Tokamak was split into two insulated hemispheres, both of which were insulated from the central cylinder. The eddy currents flowing in the vacuum vessel would become asymmetrical due to discontinuity. A 3D finite elements model was applied in order to study the eddy currents. The modeling results indicated that when the Poloidal Field (PF) was applied, the induced eddy currents would flow in the toroidal direction in the center of the hemispheres and would be forced to turn to the poloidal and radial directions due to the insulated slit. Since the eddy currents converged on the top and bottom of the vessel, the current densities there tended to be much higher than those in the equatorial plane were. Moreover, the eddy currents on the top and bottom of vacuum vessel had the same direction when the current flowed in the PF coils. These features resulted in the leading phases of signals on the top and bottom flux loops when compared with the PF waveforms.

Carcass and meat quality traits of four commercial pig crossbreeds in China

We evaluated carcass and meat quality traits of two Chinese native crossbreeds Landrace x Meishan (LM) and Duroc x (Landrace x Meishan) (DLM) and two foreign crossbreeds Duroc x (Landrace x Yorkshire) (DLY) and PIC (an imported five-way crossbreed). One hundred and twenty weaned pigs (half castrated males and half females) were reared and slaughtered at a predestinated slaughter age. The general carcass and meat quality traits were measured and analyzed. The DLY and PIC crosses had significantly heavier live weights (93.39 and 96.33 kg, P < 0.01), significantly higher dressing percentages (80.65 and 79.39%, P < 0.05), significantly bigger loin areas (42.69 and 43.91 cm(2), P < 0.001), and significantly more lean carcasses (65.78 and 66.40%, P < 0.001) than LM and DLM. On the other hand, LM had a significantly lower live weight (70.29 kg, P < 0.01), significantly thicker back fat (3.54 cm, P < 0.001), significantly less lean carcasses (46.82%, P < 0.001), and significantly less ham and breech (26.53%, P < 0.05) than the other crossbreeds. Among meat quality parameters, LM had the highest intramuscular fat content (5.02%, P < 0.001) and the smallest fiber area (3126.45 μm(2), P < 0.01). However, PIC showed the lowest pH(1) (5.82, P < 0.01) and pH(2) (5.63, P < 0.01), the highest drip loss (2.89%, P < 0.01), and the lowest intramuscular fat (1.35%, P < 0.001). We concluded that LM and DLM had good meat quality traits but poorer carcass traits than DLY and PIC; DLY had good carcass and meat quality traits; PIC had good carcass traits, but it had less intramuscular fat, lower pH and higher drip loss.

Changes in chloroplast ultrastructure, fatty acid components of thylakoid membrane and chlorophyll a fluorescence transient in flag leaves of a super-high-yield hybrid rice and its parents during the reproductive stage

In plants, it is well established that chloroplast is one of the early targgeted organelles to breakdown during leaves senescing. Here we applied a newly developed super-high-yield hybrid rice (Oryza sativa) LiangYouPeiJiu (LYPJ) and its parents lines to investigate changes in ultrastructure of chloroplasts, fatty acid composition of thylakoid membrane lipids and chlorophyll (Chl) a fluorescence transient in natural senescing leaves. We found that at full expansion of flag leaves in three lines, chloroplasts often showed oblong shapes with a typical membrane system of stroma and grana thylakoids, whereas their shapes had been changed from oblong to spherical during senescence. Our data showed that the initiation of senescence displayed accumulation of starch and an increase in the number and size of plastoglobuli with the damaged thylakoid membranes; subsequently, swollen thylakoid membranes in stroma and in grana with a significant increase in MDA content, and disorganization of thylakoid membrane system with significant changes in fatty acid composition of thylakoid membrane lipids were developed. Compared with its parents, the newly developed hybrid rice LYPJ had the highest capacity of carbohydrate transport from leaves (sources) to ears (sink), marked with the lowest accumulation of starch grains in the leaf chloroplasts, and the slowest senescing rate of chloroplast in overall leaf senescence process. Chl a fluorescence transients of three kinds of flag leaves were analyzed by so-called JIP-test. The results of analysis suggest that these findings inculding a high inherited activity of antioxidant enzymes and high photosynthetate transport to pretect chloroplast structure in the hybrid rice LYPJ have close relations to its super-high yield.

Increased SPARC expression in primary angle closure glaucoma iris

PURPOSE

SPARC (secreted protein, acidic, and rich in cysteine) is involved in extracellular matrix (ECM) organization. The purpose of this study was to evaluate the expression of SPARC in iris tissue from primary angle closure glaucoma (PACG) eyes.

METHODS

Iris tissue was obtained from peripheral iridectomies performed during trabeculectomy surgery in nine PACG and 16 primary open-angle glaucoma (POAG) eyes at the Singapore National Eye Centre. Three non-glaucoma control iris specimens were obtained from patients who underwent Descemet's stripping automated endothelial keratoplasty (DSAEK) procedure. SPARC and collagen I expression were quantified by real-time polymerase chain reaction (PCR). The histological distribution of collagen I and III in the iris stroma was determined using picrosirius red polarization. Density of the iris stromal vasculature was also calculated.

RESULTS

The mean age was 68.9+/-10.9 years and 65.7+/-12.2 years in POAG and PACG groups, respectively. The PACG iris expressed SPARC 13.6-fold more and collagen I 5.2 fold more compared to non-glaucoma control iris. The PACG iris also demonstrated 3.3 fold higher SPARC and 2.0 fold higher collagen I expression relative to the POAG iris. The density of collagen I was greater in PACG eyes than in POAG and control eyes (p<0.001). The mean density of iris stromal blood vessels per micron square area was similar in all three groups.

CONCLUSIONS

SPARC was significantly increased in the PACG iris. The data suggest that SPARC could play a role in the development of PACG by influencing the biomechanical properties of the iris through a change in ECM organization.

[Molecular mechanisms of Glanzmann thrombasthenia caused by alpha II b L721R and Q860X compound heterozygous mutation]

OBJECTIVE

To explore the molecular mechanisms of Glanzmann thrombasthenia caused by alpha II b L721R and Q860X compound heterozygous mutation.

METHODS

All exons and exon-intron boundaries of alpha II b and beta3 gene were amplified by PCR and analyzed by direct DNA sequencing. Gene polymorphisms were excluded by direct DNA sequencing. Alpha II b L721R and Q860X mutants expressing vectors were constructed by in vitro site-directed mutagenesis. The expression of alpha II b L721R and Q860X mutants on transfected cell membrane were analyzed by flow cytometry and the whole expression level was confirmed by Western blot. The subcellular localizations of alpha II b L721R and Q860X mutants were determined by immunofluorescent confocal scanning microscopy.

RESULTS

The alpha II b compound heterozygous mutations, T2255G (L721R) and C2671T (Q860X), were identified in the proband, the former being inherited from the maternal side and the latter the paternal side. The 293T cells cotransfected with mutated alpha II b L721R and wild-type beta3 expression plasmids expressed 2.1% of normal amount of alpha II b on the cell surface as shown by FACS, in contrast to 31.9% of normal amount of alpha II b on the cells cotransfected with cDNAs of mutated alpha II b Q860X and wildtype beta3 expression plasmids. Western blot of the cell lysates showed no detectable mature alpha II b in cells lysates with L721R mutant. While, truncated alpha II b protein was detected in cell lystes with Q860X mutant. Immunofluorescence studies demonstrated that both L721R and Q860X mutant pro-alpha II bbeta33 complex colocalized in endoplasmic reticulum, but a little in Golgi.

CONCLUSIONS

The L721R and Q860X mutations of alpha II b prevent transport of the pro-alpha II bbeta3 complex from the endoplasmic reticulum to the Golgi, hindering its maturation and surface expression. The impaired alpha II bbeta3 transport is responsible for the thrombasthenia.

Identification of a novel HLA-DRB1 allele (HLA-DRB1*111902*)

In this paper, we report a new HLA-DRB1 allele identified in a male acute myeloid leukaemia Chinese patient. This sample was initially typed as DRB1*11XX using commercial polymerase chain reaction-sequence-specific primers kit. When it was typed using a chip-based sequence-specific oligonucleotide technique, a novel hybridization pattern that does not match any known alleles was observed. Through sequencing, we have identified this allele as a new HLA-DRB1 allele, which was later named HLA-DRB1*111902 by the WHO Nomenclature Committee. The sequence of this new allele differs from DRB1*111901 by one nucleotide (from G to C) at 203nt of exon 2 but does not cause any amino acid substitution.

Molecular diversity and multilocus organization of the parental lines used in the International Rice Molecular Breeding Program

One hundred and ninety three parental lines obtained from 26 countries for an international rice molecular breeding program were evaluated using 101 well-distributed simple sequence repeat (SSR) markers. An overall genetic diversity of 0.68 and an average of 6.3 alleles per locus were revealed, indicating a high level of genetic variation in these lines. Cluster analysis of the 193 accessions showed three major groups and nine subgroups. Group I corresponded to the classical indica subspecies, whereas groups II and III belong to the japonica subspecies. Indica and japonica differentiation accounted for only 6.5% of the total variation in the entire sample and 93.5% was due to within-subspecies diversity. Differentiation among eco-geographic regions accounted for 24% of the diversity within the subspecies. Larger amounts of the eco-geographical differentiation were resolved within japonica than within indica. The largest indica-japonica differentiation based on the single locus level was detected by markers on chromosomes 9 and 12, while the smallest differentiation was detected by markers on chromosomes 4 and 8. Furthermore, genetic differences at the single-locus and two-locus levels, as well as components due to allelic and gametic differentiation, were revealed between indica and japonica and among the main geographic regions. The multilocus analysis in genetic diversity showed a higher proportion of variation caused by predominant non-random associations of different loci within and among the classified subspecies and geographic subdivisions. The results suggest that selection for eco-geographical adaptation on multilocus associations was largely responsible for the maintenance of the extensive variation in the primary gene pool of rice.

Pain as a mutual experience for patients, nurses and families: a perspective from Shanghai, China

The author of this article visited China for the purpose of helping the faculty of the School of Nursing learn research skills by participating in research--a kind of learn by doing. Both investigators had conducted quantitative studies in the US--one with children and one with adults--that were adapted for use in China. Seeking to also include a qualitative study, the investigators explored several possible research areas. Because pain is a universal phenomena, it was chosen as the subject for the study using the qualitative methodology reported in the first part of this article.

Thyroid storm presenting as multiple organ dysfunction syndrome

Thyroid storm is a rare disorder characterized by hypertension, hyperthermia, and multiple systems involvement. Early recognition and treatment of thyroid storm are essential in reducing morbidity and mortality from this disorder. We present the case of a patient with an atypical (normothermic, normotensive) presentation of thyroid storm, accompanied by multiple organ dysfunction syndrome, including lactic acidosis and liver dysfunction, both of which are very rare complications. This case highlights both the multiple organ systems that can be involved in thyroid storm and the importance of recognizing atypical presentations of thyroid storm.

Human G-CSF-mobilized CD34-positive peripheral blood progenitor cells can stimulate allogeneic T-cell responses: implications for graft rejection in mismatched transplantation

To investigate mechanisms of stem cell graft rejection we studied the allo-stimulatory potential of G-CSF mobilized peripheral blood progenitor cells (PBPC). CD34+ cells were purified (>95%) in a two-step procedure using immunoaffinity columns for CD34 selection and T-depletion. The capacity of CD34+ cells to stimulate allogeneic T-cell responses was compared with other cells from the same individual. CD34+ cells induced potent proliferative responses at stimulator:responder ratios of 1:20, but were approximately 50-fold less efficient compared to dendritic cells. Furthermore, CD34+ cells primed responses from partially matched allogeneic T cells in bulk cultures. Dual-colour flow cytometry showed that the co-stimulatory molecules B7.1, CD40 and ICAM-1 were absent on resting CD34-positive progenitor cells, but were induced during incubation with allogeneic lymphocytes due to a cytokine-mediated effect. Up-regulation of accessory molecules on CD34+ cells was reproduced by incubation with interferon-gamma or GM-CSF which enhanced the allo-stimulatory activity of CD34+ cells. Blocking studies with inhibitory antibodies suggested co-stimulatory functions for B7.2, ICAM-3, CD40 and LFA-3. CD34+ cells were more efficient in inducing allogeneic T-cell responses when compared to the unprocessed leukapheresis products. The reduced allo-stimulatory ability of G-CSF mobilized PBPC could be explained by the presence of CD3+ 4+ and CD3+ 8+ lymphocytes with suppressor activity. We conclude that current methods of stem cell selection for transplantation do not avoid allosensitization of the recipient and that further graft manipulation with add-back of lymphocytes or selection of subsets of CD34+ cells with reduced allo-stimulatory ability may reduce graft rejection.

A technique for dual determination of cytotoxic and helper lymphocyte precursor frequency by a miniaturized dye release method

Helper (HTLPf) and cytotoxic (CTLPf) lymphocyte precursor frequency assays are increasingly used in bone marrow stem cell and organ transplant compatibility testing. Current techniques require large cell numbers and radioisotopes. To improve the technique, we developed a miniaturized fluorescent read-out combined HTLPf/CTLPf limiting dilution assay. The assay requires only 5 x 10(6) stimulators, 2 x 10(6) responders and 0.24 x 10(6) target cells in Terasaki plates (40 microl/well). For the HTLPf, culture supernatants from each well were assayed for IL-2 production. The IL-2-dependent proliferation of the mouse 9.12 cell line was detected by a semi-automated fluorescent dye technique. After addition of rhIL-2 (recombinant human IL-2) on days 3 and 7, CTLPs were detected on day 10 by measuring the lysis of dye-labeled targets. Results were comparable to standard radioisotope-based techniques. The assay had a coefficient of variation of approximately 30%. The assay detected helper CD4 cells, pure cytotoxic CD8, helper CD8 cells and helper/cytotoxic CD8 cells. Discrimination was demonstrated between HLA-matched related and non-related pairs. The ease of testing and small cell numbers required should facilitate further evaluation of HTLPf and CTLPf for compatibility testing in unrelated donor transplantation and monitoring immune responses following adoptive transfer of lymphocytes.

Haematological response of patients with myelodysplastic syndrome to antithymocyte globulin is associated with a loss of lymphocyte-mediated inhibition of CFU-GM and alterations in T-cell receptor Vbeta profiles

We have demonstrated that 44% of myelodysplastic syndrome (MDS) patients with cytopenia have a haematological response to antithymocyte globulin (ATG). Three ATG responders and two non-responders with refractory anaemia were further studied for lymphocyte-mediated inhibition of bone marrow using a standard CFU-GM assay. In responders, peripheral blood lymphocytes (PBL) added at a 5:1 ratio suppressed CFU-GM by 54+/-9% (P=0.04) and was reversed by ATG treatment. Pre-treatment marrow depleted of CD3 lymphocytes, increased CFU-GM by 32% (P=0.02) in an ATG responder, but not in a non-responder. CD3 lymphocytes from 6-month post-treatment marrow did not inhibit pre-treatment CFU-GM, indicating ATG had affected the T cells. Pre-treatment marrow depleted of CD8 lymphocytes, increased CFU-GM by 60% (P=0.01) and 49% (P=0.03) in two ATG responders, but not in a non-responder. Inhibition required cell-cell interaction through MHCI. TCRVbeta families, analysed by SSCP, changed from clonal to polyclonal in one ATG responder after 6 months, but clones persisted in a non-responder. These results indicate patients with refractory anaemia who respond to ATG have CD8 T-cell clones that mediate MHCI-restricted suppression of CFU-GM which are replaced by polyclonal T cells that do not suppress CFU-GM after ATG treatment.

Specific depletion of alloreactive T cells in HLA-identical siblings: a method for separating graft-versus-host and graft-versus-leukaemia reactions

Accumulating evidence indicates that alloreactive donor T cells confer both graft-versus-host (GVH) and graft-versus-leukaemia (GVL) reactivity following allogeneic bone marrow transplantation. We have developed a method to deplete alloreactive donor T cells with an immunotoxin targeting the alpha chain of the IL-2 receptor. In patients with chronic myeloid leukaemia and their HLA-identical sibling donors, we measured donor helper T-lymphocyte precursor frequencies (HTLPf) against recipient peripheral blood mononuclear cells (PBMNC; donor versus host), recipient leukaemia cells (donor versus leukaemia) and third-party PBMNC, before and after the depletion. In seven pairs there was a 4.3-fold reduction of donor-versus-host HTLPf (P=0.017), without a significant change in the donor frequencies against third party (P=0.96). In eight further donor-recipient pairs, immunotoxin-depleted donor versus patient PBMNC HTLPf 4.5-fold (mean 1/155,000 before and 1/839,000 after depletion, P=0.007). There was a smaller non-significant 1.8-fold reduction in donor-versus-leukaemia HTLPf from 1/192,000 to 1/334,000 (P=0.19). These results suggest that selective T-cell depletion can significantly deplete donor anti-host reactivity while conserving anti-leukaemia reactivity in HLA-matched donor-recipient pairs.

Transfection of interleukin-12 cDNAs into tumor cells induces cytotoxic immune responses against native tumor: implications for tumor vaccination

Interleukin-12 (IL-12) is a heterodimeric cytokine that is central to the development of T helper 1-dependent cellular immunity. Although this cytokine has potential therapeutic application as an antineoplastic agent, the systemic infusion of IL-12 has led to toxic fatalities; hence, restriction of expression of IL-12 to the microenvironment of target tumor cells has obvious appeal. In this study, we examined whether tumor cells that were liposome-transfected with IL-12 could enhance the induction of cytolytic lymphocyte immunity to the native tumor. The plasmid expression vector that we used has several useful features including replication to high copy number as an episome and a polycistronic message enabling the production of both the p35 and p40 subunits of IL-12 without alternative splicing; up to 3 ng/mL/10(6)/48 hours of IL-12 was produced following transfection. Tumor cells transfected with IL-12 were superior to untransfected cells in the induction of lymphocyte-mediated cytolysis. IL-12 transfectants induced a heterogeneous population of natural killer, lymphokine activated killer, and cytolytic T lymphocytes, the latter of which exhibited tumor-specific activity. Our studies suggest that liposome-mediated transfection of tumor cells with an episomal, high copy number plasmid vector expressing both IL-12 subunits is a promising approach to cancer vaccination, a strategy that could be implemented ex vivo in treating malignancies such as metastatic ovarian cancer.

Regulation of a graft-versus-leukemia effect by major histocompatibility complex class II molecules on leukemia cells: HLA-DR1 expression renders K562 cell tumors resistant to adoptively transferred lymphocytes in severe combined immunodeficiency mice/nonobese diabetic mice

To understand the role of key molecules in determining the strength and nature of allogeneic T-cell response to leukemia, we transfected HLA-DR1 into the major histocompatibility complex (MHC)-deficient, natural killer (NK)-cell sensitive K562 leukemia cell line. Untransfected K562 cells stimulated NK proliferation in vitro and formed subcutaneous tumors in severe combined immunodeficiency/non-obese diabetic (SCID/NOD) mice. Tumor growth was inhibited by adoptive intravenous transfer of fresh unprimed peripheral blood mononuclear cells (PBMC). In contrast, HLA-DR1 transfected cells stimulated CD4(+) T cells, but not NK-cell proliferation in vitro and formed tumors resistant to fresh PBMC in SCID/NOD mice. Tumors not expressing MHC were infiltrated with CD16(+)CD56(+) lymphocytes whereas nonregressing HLA-DR1 expressing tumors showed only a scanty infiltration with both T-cell and NK-cell subsets. The results indicate that MHC class II expression by leukemia cells can determine the effector cell type that it engages. In vivo MHC class II expression rendered K562 cell tumors resistant to NK-cell mediated antitumor reactivity.

The allogeneic CD4+ T-cell-mediated graft-versus-leukemia effect

CD4+ T-cells have emerged as important cells in the initiation and delivery of the GVL response. Nevertheless it seems likely that they act in concert with other T-cells and NK cell effectors to produce the full in vivo effect of GVL. How they interact with other effectors is yet to be determined. Furthermore it is very likely that different hematological malignancies have different susceptibility to attack by various lymphocyte subsets, depending upon their MHC expression, nature of the antigens presented and other properties not yet defined. Here we specifically focus on the role of CD4+ T-cells in mediating GVL, particularly in chronic myeloid leukemia. Candidate antigens recognised by CD4+ cells are described and new approaches to GVL modulation in clinical bone marrow transplantation are discussed.

Cytotoxic T lymphocytes specific for a nonpolymorphic proteinase 3 peptide preferentially inhibit chronic myeloid leukemia colony-forming units

We previously showed that a peptide (PR1) derived from the primary granule enzyme proteinase 3 induced peptide specific cytotoxic T lymphocytes (CTL) in a normal HLA-A2.1+ individual. These CTL showed HLA-restricted cytotoxicity to myeloid leukemias (which overexpress proteinase 3). To further investigate their antileukemic potential, we studied the ability of PR1-specific CTL, derived from two HLA-A2.1+ normal individuals, to inhibit colony-forming unit granulocyte-macrophage (CFU-GM) from normal and leukemic individuals. CTL from 20 day PR1 peptide-pulsed lymphocyte cultures showed 89% to 98% HLA-A2.1-restricted colony inhibition of chronic myeloid leukemia targets. Colony formation in normal HLA-A2.1+ bone marrow or HLA-A2.1- CML cells was not inhibited. Sequencing of the exon encoding PR1 showed that colony inhibition was not caused by polymorphic differences in proteinase 3 between effectors and targets. Analysis by flow cytometry showed that proteinase 3 was overexpressed in the leukemia targets compared with normal marrow targets (median channel fluorescence 1,399 v 298, P = .009). These results show that PR1-specific allogeneic T cells preferentially inhibit leukemic CFU-GM based on overexpression of proteinase 3, and that proteinase 3-specific CTL could be used for leukemia-specific adoptive immunotherapy.

Preferential usage of T cell receptor (TCR) V beta by allogeneic T cells recognizing myeloid leukemia cells: implications for separating graft-versus-leukemia effect from graft-versus-host disease

New understanding of the alloresponse following bone marrow transplantation supports the possibility that the graft-versus-host disease (GVHD) response can be separated from a favorable graft-versus-leukemia (GVL) effect. We used chronic myeloid leukemia (CML) cells to generate 122 recipient-reactive T cell clones from a closely HLA-matched sibling responder. Clones were tested for their proliferative response to stimulator CML cells or PHA-transformed (non-leukemic) lymphoblasts. Of 78 clones tested, 32 recognized both leukemia cells and PHA blasts, 19 only CML and four only PHA blasts. The remainder were non-specific responders. This functional specificity corresponded to distinct patterns of T cell receptor (TCR) V beta usage: clones recognizing CML cells preferentially used V beta 5, V beta 6/7 while clones recognizing both CML and PHA blasts or only PHA blasts preferentially used V beta 3 and V beta 8. It may therefore be possible to identify in vitro-generated myeloid leukemia-restricted donor T cells by their pattern of V beta usage. TCR V beta antibodies could thus be used to select and expand leukemia-restricted donor T cells for transfusion after BMT to specifically enhance the GVL response.

Immune escape from a graft-versus-leukemia effect may play a role in the relapse of myeloid leukemias following allogeneic bone marrow transplantation

We studied patients relapsing with myeloid leukemias following allogeneic bone marrow transplantation (BMT) for evidence of immune escape by clonal evolution of the leukemia. Relapsed cells from four out of five patients had a reduced ability to stimulate proliferation of lymphocytes from an HLA-mismatched responder. There was decreased susceptibility to lysis by CTL in three and reduced susceptibility to NK-mediated lysis in one. Relapsed leukemias had marked alterations in expression of critical surface molecules involved in immune responsiveness. Three had decreased expression of MHC class I and II, with no change or increase in CD54 (ICAM-1) or CD80 (B7.1). None of these responded to treatment with donor lymphocytes. Three patients showed no change, or increased expression of MHC with no change or decrease in ICAM-1 or B7.1. Two achieved remission - one in response to donor lymphocytes and one following withdrawal of cyclosporine. In one patient transplanted with myelodysplastic syndrome in transformation, interferon-gamma upregulated expression of MHC molecules in relapsed cells and increased their stimulatory capacity and target susceptibility to unmatched responder lymphocytes. These results suggest that immune escape through clonal evolution of the leukemia is a common occurrence in patients who relapse with myelogenous leukemias after BMT.

Association of natural killer cell immune recovery with a graft-versus-leukemia effect independent of graft-versus-host disease following allogeneic bone marrow transplantation

There is good evidence that T lymphocytes play an important role in the graft-versus-leukemia (GVL) effect following allogeneic bone marrow transplantation (BMT) for hematologic malignancies. However, the role of natural killer (NK) cells in GVL is less clear. To further investigate a possible association of NK cells with GVL we studied 15 patients undergoing BMT for chronic myeloid leukemia (CML), correlating T-cell (CD4+ and CD8+) and NK-cell (CD16+ 56+) recovery with relapse and graft-versus-host disease (GVHD). Patients were studied on three occasions up to 9 months after BMT, for lymphocyte surface phenotype and for spontaneous and IL-2-stimulated (LAK cell) cytotoxic function. Circulating CD8+ and NK but not CD4+ cell numbers were significantly lower in five patients who relapsed compared with those remaining in remission after BMT (mean 0.03 vs 0.32 x 10(9)/l, p = 0.002 for CD8+ cells: mean 0.03 vs 0.11 x 10(9)/l, p = 0.002 for NK cells). There was no correlation of CD4+. CD8+, or NK cell numbers and development of grade-II or more acute GVHD. Spontaneous NK cytotoxic function rose to within the normal range in the first month after BMT. LAK function remained low during the study period. These results link NK cell recovery more closely with a GVL than with a GVH effect.

Targeted T-cell therapy for human leukemia: cytotoxic T lymphocytes specific for a peptide derived from proteinase 3 preferentially lyse human myeloid leukemia cells

Proteinase 3 is present in high concentration in the primary granules of acute and chronic myeloid leukemia blasts, and may represent a potential T-cell target antigen. We screened proteinase 3 against the binding motif of HLA-A2.1. Based on its high predicted binding, a 9-mer peptide, "PR-1," was synthesized and tested for binding to HLA-A2.1 using the T2 cell line. PR-1 at 100 micrograms/mL significantly increased expression of HLA-A2.1, with median channel of fluorescence increasing from 22 to 294. Binding half-life was determined to be 1,460 minutes by I125-labeled beta 2-microglobulin incorporation. HLA-A2.1+ peripheral blood mononuclear cells from a normal donor were used to generate a T-cell line specific for PR-1. The line demonstrated 85% PR-1-specific lysis at an E:T ratio of 50:1, compared with 20% lysis without PR-1, using T2 cells as targets. It also showed 79% specific lysis to fresh chronic myelogenous leukemia blasts, 54% to fresh acute myelogenous leukemia blasts, and only background lysis (< 20%) to HLA-A2.1+ normal allogeneic marrow cells. The amount of lysis of HLA-A2.1+ myeloid cells was proportional to cytoplasmic proteinase 3 expression. Thus, HLA-A2.1-restricted cytotoxic T cells, raised against a peptide contained in proteinase 3, preferentially lysed fresh human leukemic cells.

Alloreactive CD4+ T lymphocytes can exert cytotoxicity to chronic myeloid leukaemia cells processing and presenting exogenous antigen

Existing evidence supports that CD4+ T lymphocytes play a role in the graft-versus-leukaemia (GVL) reaction after allogeneic bone marrow transplantation (BMT) for chronic myeloid leukaemia (CML), not only as initiators of the immune response but also as effectors of GVL. In BMT between HLA-identical pairs this CD4-mediated GVL would require CML cells to process and present antigens through MHC class II molecules. To investigate whether CML cells are capable of processing and presenting antigens, and suitable targets for CD4+ T-cell-mediated cytotoxicity, we generated HLA-DR1-restricted CD4+ cytotoxic T-cell clones that specifically recognized tuberculous purified protein derivative (PPD). We have shown that CML cells and B lymphoblastoid cell line (B-LCL) cells but not PHA-blasts from patients with CML processed exogenous antigen, PPD, and induced proliferative and cytotoxic CD4+ T-cell responses. Antigen presentation was blocked by antibodies to HLA-DR but not to MHC class I and by treatment with chloroquine and brefeldin. This indicates that CML cells use a classic MHC class II antigen processing pathway to present PPD antigens to CD4+ T cells. Cytotoxicity to CML was shown by antibody blocking studies to be mediated mainly through fas antigen. These findings indicate that donor CD4+ T cells alone are sufficient to mediate GVL effects following allogeneic BMT for CML.

Specific depletion of alloreactivity against haplotype mismatched related individuals by a recombinant immunotoxin: a new approach to graft-versus-host disease prophylaxis in haploidentical bone marrow transplantation

Haploidentical bone marrow transplantation (BMT) is associated with a high risk of severe graft-versus-host disease (GVHD). While pan-T cell depletion of the graft is the most effective means of preventing severe GVHD, it is associated with delayed recovery of T cell function leading to fatal infections. We used two related Pseudomonas exotoxin-based immunotoxins, anti-Tac(Fv)-PE38 and anti-Tac(Fv)-PE38KDEL, that both target the IL-2 receptor on activated T cells, to specifically deplete alloreactive lymphocytes against haploidentical stimulators. The functional capacity of the remaining lymphocytes was tested in proliferative assays against the original haploidentical stimulator and pooled cells from other mismatched donors (third party). We varied the recombinant toxin concentration and schedule to determine the optimum conditions for selective depletion. In 10 experiments, the mean residual reactivity after depletion was 7.6 +/- 1.4% against the haploidentical stimulator and 64.2 +/- 5% against the third party, expressed as a percentage of the undepleted response to the same stimulators. Depletion was shown to be specific for mixed lymphocyte culture (MLC)-activated lymphocytes. The immunotoxin did not affect CFU-GM growth of normal BM cells. This selective depletion of haploidentical alloreactivity could be used to prevent GVHD while conserving immune recovery following haploidentical BMT.

Interaction of natural killer cells with MHC class II: reversal of HLA-DR1-mediated protection of K562 transfectant from natural killer cell-mediated cytolysis by brefeldin-A

Major histocompatibility complex (MHC) class I antigens on tumour cell surfaces have been shown to modulate target susceptibility to natural killer (NK) cell-mediated lysis in some, although not all, systems investigated. MHC class II expression may also affect NK cell function, but the mechanism by which MHC class II antigen regulates NK cell activity has not been fully examined. In this study we induced HLA-DR1 expression by gene transfection into the classic NK-sensitive K562 cell line to study the interaction of NK cells with MHC class II molecules and the effect of brefeldin-A (BFA), an endogenous antigen-processing pathway blocker, on NK-target cell interaction. We demonstrated that the expression of HLA-DR1 on the cell surface reduced K562 cell susceptibility to NK lysis by peripheral blood monuclear cells and a NK cell line. The effect was demonstrable in prolonged (8 hr) cytotoxicity assays and was blocked by pretreatment of target cells with anti-HLA-DR antibody. Treatment of K562 DR transfectant with BFA abrogated the resistance of K562 transfectant to NK-mediated cytolysis. These findings indicate that HLA class II molecules regulate NK cell function and target recognition, and suggest that endogenous peptides presented through MHC molecules are responsible for regulating NK cytolysis.

Cellular and cytokine-mediated effects of CD4-positive lymphocyte lines generated in vitro against chronic myelogenous leukemia

Leukemia cells from a patient with chronic myelogenous leukemia (CML) in accelerated phase were used to generate CD4+, CD8- T lymphocyte lines from an unrelated normal subject sharing HLA-A2 and DR4 with the patient. In chromium release cytotoxicity assays, lines showed specificity for patient cells and were unreactive against third-party CML and K562 cells. Cytotoxicity was blocked by anti HLA-DR on target cells. Some lines showed preferential cytotoxicity to PHA-induced lymphoblasts and some to CML cells. There was a broad correlation between cytotoxicity to CML cells by 51Cr release and CFU-CM inhibition. However, even weakly cytotoxic lines were inhibitory to CML CFU-GM. This effect was partly mediated by the T cell line supernatant: four of five supernatants tested inhibited the growth of CFU-GM. Antibody neutralization studies demonstrated the presence of gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) in these supernatants. There was a greater suppression of CML CFU-GM when compared with CFU-GM from normal individuals. One supernatant from a noncytotoxic T cell line stimulated CFU-GM and was demonstrated by antibody neutralization studies to contain interleukin-3 (IL-3) and GM-CSF. These data indicate that alloreacting CD4 cells exert both cytotoxic and cytokine-mediated antileukemia effects which may relate to the graft-vs.-leukemia (GVL) effect in CML following bone marrow transplantation.

Comparison of helper and cytotoxic antirecipient T cell frequencies in unrelated bone marrow transplantation

Donor/recipient histocompatibility antigen differences initiate acute graft-versus-host disease (GVHD) after bone marrow transplantation. Frequency analysis, using limiting dilution techniques, of functionally defined (helper or cytotoxic) antirecipient T lymphocyte precursors in the peripheral blood of the donor has been shown to be an accurate predictor for the development of moderate-to-severe acute GVHD. Here, we describe a sensitive assay for measuring alloreactive helper (IL-2-producing) T lymphocyte precursor (HTLp) frequencies, and compare the ability of this assay and the cytotoxic T lymphocyte precursor (CTLp) assay to detect HLA- class II and class I differences and to predict clinical outcome in a cohort of unrelated donor/recipient BMT pairs. Twenty-two pairs underwent unrelated donor BMT. Patients with high (> 1:100 x 10(3)) HTLp or CTLp frequencies had a higher incidence of moderate-to-severe (grades II-IV) acute GVHD (80% and 100%, respectively) than pairs with low (< 1:100 x 10(3)) frequencies (40% and 57%, respectively). Ten (45%) patients have died, but all patients with both a low HTLp and low CTLp frequency remain alive. The HTLp and CTLp assays provided similar predictive information for outcome. Given that the HTLp assay is more rapid and less labor intensive, it offers an additional or alternative functional method for donor selection in unrelated donor BMT.

Distinct T cell populations distinguish chronic myeloid leukaemia cells from lymphocytes in the same individual: a model for separating GVHD from GVL reactions

Donor lymphocyte responses to minor histocompatibility antigen (mHA) differences are involved in allo-responses between HLA matched pairs causing GVHD and graft-versus-leukaemia (GVL). Since some mHA are tissue-restricted, GVHD and GVL responses may be separable. We studied donor lymphocyte responses to patients with CML in a series of 10 HLA-matched sibling and 10 unrelated donor-recipient pairs comparing proliferation to recipient PHA blasts and CML cells and attempting to selectively deplete responses to PHA blasts in vitro. Responses in counts per min (c.p.m) to CML cells and PHA blasts were, respectively, 2809 +/- 2205 (SD) and 7376 +/- 1877 in related and 12,107 +/- 7191 and 26,136 +/- 22,479 in unrelated pairs. Autologous responses to PHA blasts were significantly lower (mean 779 +/- 735) (p < 0.001). Results correlated with clinical outcome: higher responses to recipient cells correlated with transplant-related death (p = 0.02 for CML and p = 0.06 for PHA blasts). Higher responses to CML correlated with GVHD grade > or = II (p = 0.025). Donor lymphocytes exposed to recipient PHA blasts for 5 days and treated with a ricin-conjugated anti-CD25 antibody retained over 75% of their response to CML but < 10% to PHA blasts. Similarly, depletion of response to CML but not to PHA blasts occurred when CML was the primary challenge. These results indicate that distinct populations of donor T cells respond to recipient leukaemic and non-leukaemic cells, and provide the basis for a clinically applicable technique to selectively deplete donor GVHD reacting cells while conserving GVL.

[The detection and significance of HBV-DNA in serum and liver of advanced schistosomiasis patients]

Hepatitis B virus deoxyribonucleic acid (HBV-DNA) and surface antigen (HBsAg) in the serum and liver specimens from 31 patients with advanced schistosomiasis were investigated. The patients have been followed up for six years. The presence of HBsAg and HBcAb in serum among patients with advanced schistosomiasis were significantly more frequent than that in the control group (P < 0.05), but the prevalence of HBV-DNA and HBeAg in the patients were not significantly different from that in the controls (P > 0.05). The positive rate of HBV-DNA and HBsAg in liver was 19.4% and 48.4% respectively, which were greater than that in serum. The presence of HBV-DNA in patients with advanced schistosomiasis was associated with high mortality and the cause of death was either hepatic failure or hepatocellular carcinoma. The results suggest that it is important to detect HBV-DNA both in surum and liver. Antiviral therapy for patients with advanced schistosomiasis who had detectable HBV-DNA may improve the prognosis.

T cell and NK cell mediated graft-versus-leukaemia reactivity following donor buffy coat transfusion to treat relapse after marrow transplantation for chronic myeloid leukaemia

Two patients with chronic myeloid leukaemia in cytogenetic relapse following T lymphocyte-depleted BMT were treated with transfusions of donor buffy coat leucocytes. In both patients the marrow reverted to a completely normal karyotype and was negative for the BCR-ABL fusion gene transcript by polymerase chain reaction analysis. Before buffy coat transfusion the cytotoxic T lymphocyte precursor frequency against pre-BMT patient leukaemia cells (Lk-CTLP) was lower than that against pre-BMT patient PHA-transformed lymphocytes (Ly-CTLP) in both cases. At 2 weeks (case 1) and 8 weeks (case 2) after transfusion this ratio inverted so that Lk-CTLP predominated. Natural killer (NK) function fell initially and then recovered to exceed pre-transfusion values prior to normalization of the bone marrow karyotype. These changes in cytotoxic T lymphocytes and NK cells following donor buffy coat transfusions for patients with relapsed chronic myeloid leukaemia after marrow transplantation support the concept of a graft-versus-leukaemia effect mediated by both MHC restricted and non-restricted pathways.