[Evaluation of the performance of InnowaveDX MTB/RIF for the detection of Mycobacterium tuberculosis complex and rifampicin resistance].

Objective: To evaluate the performance of Mycobacterium tuberculosis and rifampicin resistance mutation detection kit (InnowaveDX MTB/RIF, referred to as "InnowaveDX") in diagnosing tuberculosis and rifampicin resistance using sputum samples. Methods: From June 19, 2020 to May 16, 2022, patients with suspected tuberculosis were prospectively and consecutively enrolled in Hunan Provincial Tuberculosis Prevention and Control Institute, Henan Provincial Hospital of Infectious Diseases and Wuhan Jinyintan Hospital. A total of 1 328 patients with suspected tuberculosis were finally included. According to the inclusion and exclusion criteria, 1 035 pulmonary tuberculosis patients (357 were confirmed tuberculosis cases and 678 were clinically diagnosed tuberculosis cases) and 180 non-tuberculosis patients were finally included. Sputum samples were collected from all patients for routine sputum smear acid-fastness tests, mycobacterial culture and drug susceptibility testing. Moreover, the diagnostic value of Xpert®MTB/RIF (referred to as "Xpert") and InnowaveDXin detecting tuberculosis and rifampicin resistance was evaluated. Clinical diagnosis and culture results of Mycobacterium tuberculosis were used as reference standards to assess tuberculosis diagnosis, and phenotypic drug sensitivity and Xpert were used as reference standards to assess rifampicin resistance. The sensitivity, specificity, positive predictive value and negative predictive value of the two methods for tuberculosis diagnosis and rifampicin resistance were analyzed. The consistency of the two techniques was analyzed usingkappa test. Results: Taking clinical diagnosis as the reference standard, the detection sensitivity of InnowaveDX [58.0% (600/1 035)] was higher than that of Xpert [51.7% (535/1 035)] in 1035 patients with pulmonary tuberculosis, and the difference was statistically significant (P<0.001). In 270 pulmonary tuberculosis patients with culture-positive pulmonary tuberculosis identified as M.tuberculosis-complex, the positive rates of InnowaveDX and Xpert were both high [99.6%(269/270)and 98.2%(265/270), respectively] and there was no statistical difference. In culture-negative patients with pulmonary tuberculosis, the sensitivity of InnowaveDX was 38.8% (198/511), which was higher than that of Xpert (29.4%, 150/511), and the difference was statistically significant (P<0.001). Taking phenotypic drug-susceptibility testing (DST) as reference, the sensitivity of InnowaveDX to rifampicin resistance was 99.0% (95%CI: 94.7%-100.0%) and the specificity was 94.0%(95%CI: 88.5%-97.4%). With Xpert as the reference, the sensitivity and specificity of InnowaveDX were 97.1% (95%CI: 93.4%-99.1%) and 99.7% (95%CI: 98.4%-100.0%), respectively, and the kappa value was 0.97 (P<0.001). Conclusions: InnowaveDX show a high sensitivity for detecting Mycobacterium tuberculosis, especially in pulmonary tuberculosis patients with a clinical diagnosis and negative culture results. It also showed high sensitivity in detecting rifampicin resistance with DST and Xpert as reference respectively. InnowaveDX is an early and accurate diagnostic tool for TB and drug-resistant TB, particularly suitable for application in low- and middle-income countries.

[Clinical value of routine contrast esophagram in the diagnosis of anastomotic leakage for three-incision esophagectomy with cervical anastomosis].

Objective: To examine the clinical value of routine contrast esophagram (RCE) for the diagnosis of anastomotic leakage (AL) after three-incision esophagectomy with cervical anastomosis. Methods: Clinical data of 1 022 patients with esophageal cancer who underwent McKeown three-incision esophagectomy with cervical anastomosis from January 2015 to December 2019 at Department of Minimally Invasive Esophageal Surgery, Tianjin Medical University Cancer Hospital and Institute were analyzed retrospectively. There were 876 males and 146 females, aging(M(IQR)) 48(16) years (range: 36 to 84 years). There were 253 patients (24.8%) with neoadjuvant therapy, and 817 patients (79.9%) with minimally invasive esophagectomy. According to the diagnosis and treatment habits of the attending surgeons, 333 patients were included in the RCE group, and RCE was performed on the 7th day postoperative, while 689 patients were included in the non-RCE group, and RCE was performed when the patients had suspicious symptoms. Taking clinical symptoms, RCE, CT, endoscopy and other methods as reference to the diagnosis of AL, the sensitivity and specificity were used to analyze and evaluate the efficacy of RCE for the diagnosis of AL. The data were compared by U test or χ² test between groups. Results: The incidence rate of AL after three-incision esophagectomy was 7.34% (75/1 022), including 30 cases in the RCE group and 45 cases in the non-RCE group (9.0%(30/333) vs. 6.5%(45/689), χ²=2.027, P=0.155). The diagnostic time of AL was 9(5) days postoperative (range: 4 to 30 days). Among them, 23 cases showed cervical leakages, 50 cases showed intro-thoracic leakages, and 2 cases both cervical and intro-thoracic leakages. The diagnostic time of patients with intro-thoracic leakages was longer than that of cervical leakages (10(4) days vs. 6(3) days, Z=-2.517, P=0.012). Among the 333 patients in the RCE group, 16 cases of RCE indicated leakages including 11 cases of true positive and 5 cases determined to be false positive, while 317 cases indicated no abnormalities including 19 cases developed leakages. The sensitivity and specificity of RCE to detect AL were 36.7%(11/30) and 98.3%(298/333), respectively. The Youden-index was 0.35, and the diagnostic accuracy was 92.8%(309/333). The positive and negative predictive value were 11/16 and 94.0%(298/317), respectively. Conclusions: Routine contrast esophagram after three-incision esophagectomy with cervical anastomosis has low sensitivity and high specificity in the diagnosis of AL. The diagnostic time of AL is the 9th day after surgery. It is necessary to prolong the observation time clinically, and combine RCE with CT, endoscopy and other inspection methods for diagnosis.

Potential role of miR-425, miR-155 and miR-33 in Streptococcus pneumoniae pneumonia by using bioinformatics analysis and experimental validation.

Streptococcus pneumoniae (S. pneumoniae) pneumonia is the most common cause of community-acquired pneumonia (CAP). Previous studies have suggested the diagnostic potential of microRNAs (miRNAs) in infectious diseases. In the present study, we aimed to evaluate the potential role of miRNAs in S. pneumoniae pneumonia by using bioinformatics analysis and experimental validation. Gene Expression Omnibus (GEO) datasets including GSE97922 and GSE83615 were analyzed for identifying the differentially expressed miRNAs; the miRNA-target genes network was constructed by using miRNet and the targeted genes were subject to Gene Ontology enrichment, Kyoto Encyclopedia of Genes and Genomes and REACTOME pathway analysis; the miRNA and mRNA expression levels were determined by quantitative real-time PCR; protein concentrations were determined by enzyme-linked immunosorbent assay. Our results showed that miR-425, miR-155 and miR-33 were up-regulated in the serum from CAP patients when compared to healthy controls; whereas there was no significant difference in serum miR-222, miR-149, miR-186 and miR-132 expression levels between healthy controls and CAP patients. In vitro functional studies showed that lipopolysaccharides (LPS) induced the up-regulation of miR-425, miR-155 and miR-33 in RAW264.7 cells, and miR-425, miR-155 and miR-33 inhibition attenuated LPS-induced inflammatory responses in RAW264.7 cells. In conclusion, our results showed that miR-425, miR-155 and miR-33 were up-regulated in the serum from CAP patients by using bioinformatics analysis and experimental validation; furthermore, miR-425, miR-155 and miR-33 inhibition attenuated LPS-induced inflammatory responses in RAW264.7 cells. Nevertheless, our studies are still at the preliminary stages, and the detailed roles of miR-425, miR-155 and miR-33 in S. pneumoniae pneumonia still require further investigation.

[Comparison of the prognostic value of the seventh and eighth edition of The AJCC Esophageal Cancer Staging System for the patients with stage â ¡ and â ¢esophageal squamous cell carcinoma].

Objective: To compare and evaluate the prognostic value of the 7(th) and 8(th) edition of The AJCC Esophageal Cancer Staging System for patients with stage Ⅱ and Ⅲ esophageal squamous cell carcinoma. Methods: The clinical data of 328 esophageal cancer patients who received operation at Department of Esophageal Cancer, Tianjin Tumour Hospital from January 2006 to December 2010 were restrospectively analyzed. There were 63 female and 265 male patients. The mean age was 65 (range: 33 to 87) years. Univariate and multivariate analysis were performed to identify the prognosis factors. Results: The five years overall survival rates among patients with stage Ⅱ and Ⅲ were both significantly different (χ(2)=87.035, 84.730, all P=0.000) according to the 7(th) and 8(th) editions of the TNM staging systems. The five years overall survival rate among patients with stage ⅡB and ⅢA were significantly different (39.6% vs 23.4%, P=0.001) according to the 7(th) edition of the esophageal cancer staging systems.According to the 8(th) edition of the esophageal cancer staging system, the 5 years survival rate of patients with stage ⅡA and ⅡB, ⅢB and Ⅳ was statistically significant (58.5% vs. 35.5%, P=0.040; 18.9% vs. 0, P=0.000). In multivariate analysis, tumor size, T staging, N staging and tumor differentiation (HR=1.592, 95%CI: 1.185 to 2.139, P=0.002; HR=1.519, 95% CI: 1.236 to 1.867, P=0.000; HR=1.647, 95% CI: 1.448 to 1.874, P=0.000; HR=1.404, 95% CI: 1.059 to 1.861, P=0.018) were the main independent prognosis factors affecting the prognosis of esophageal squamous cell carcinoma patients. Conclusions: Both the 7(th) and the 8(th) editions of TNM staging systems are able to reflect the clinical prognosis of patients receiving radical resection of esophageal cancer, and the factors of tumor size, differentiaton, invasion depth and lymph node metastases are the independent predictors of prognosis. The 8(th) edition provides a more detailed and more reasonable for the staging of stage Ⅱ and Ⅲ for esophageal cancer patients than the 7(th) edition, and it is more accurate for the prognosis of patients with esophageal cancer after surgery.

Clinical significance of preoperative and postoperative cytokeratin 19 messenger RNA level in peripheral blood of esophageal cancer patients.

The purpose of this study is to analyze the correlation between preoperative/postoperative Cytokeratin 19 (CK19) messenger RNA (mRNA) level in peripheral blood (PB) and the clinical significance in esophageal cancer patients with different clinicopathological factors. We detected the preoperative and postoperative CK19 mRNA level in the PB of 139 esophageal cancer patients who underwent complete resection and evaluated its clinical significance. We found that both the preoperative and postoperative CK19 mRNA level increased in the esophageal cancer patients with lymph node metastasis, relapse or distant metastasis compared with that in cancers without lymph node metastasis, relapse or distant metastasis. High postoperative CK19 mRNA levels indicate a short disease-free survival (DFS) for the whole cohort esophageal cancer patients, whereas the high preoperative CK19 mRNA levels only indicate a short DFS for the esophageal cancer patients with squamous cell carcinoma, TNM III stage, and lymph node metastasis. The dynamic change of CK19 mRNA levels could indicate the prognosis of esophageal cancer patients. The patients with decreasing CK19 mRNA level after surgery had good prognosis, and the patients with changeless CK19 mRNA level had poor prognosis. Taken together, CK19 mRNA levels could be a promising marker in assessing prognosis or assigning treatment for the esophageal cancer patients according to different clinicopathological factors.

Primary esophageal adenosquamous carcinoma: a retrospective analysis of 24 cases.

Primary adenosquamous carcinoma (ASC) of the esophagus is a rare kind of malignancy characterized by mixed glandular and squamous differentiation as well as a propensity for aggressive clinical behavior. Data on the evaluation of the clinicopathological features and the prognosis of patients suffering from this malignancy are few because of the rarity of this disease. We conducted a retrospective review of 24 patients with primary esophageal ASC among 6546 esophageal cancer patients who underwent transthoracic esophagectomy in our hospital. The clinicopathological presentation, diagnosis, treatment, and prognostic factors of the patients were respectively investigated. The Kaplan-Meier method and the log rank test were used to calculate and compare overall survival (OS). The Cox proportional hazards model was employed to identify independent prognostic factors. There were 18 males and 6 females with a median age of 60 years (range: 40-78 years). The clinical symptoms, macroscopic type, as well as the radiological and endoscopic features of esophageal ASC were similar to those of esophageal squamous cell carcinoma. Sixteen (88.9%) of the 18 cases who underwent preoperative esophagoscopic biopsy were misdiagnosed as adenocarcinoma or squamous cell carcinoma. The overall median follow-up period was 36 months, and the median survival time was 32 months. The 1, 3, 5-year OS rates were 75.0%, 48.5%, and 19.4%, respectively. Univariate analysis showed that gender (P=0.047), lymph node metastasis (P=0.007), and TNM stage (P=0.037) were important factors associated with OS of the 22 patients who underwent radical resection. Multivariate analysis showed that the pathological N stage was the only independent prognostic factor (P=0.031, hazard ratio [HR], 5.369, 95% confidence interval [CI], 1.167-24.700). These results suggest that esophageal ASC is an uncommon disease prone to be misdiagnosed by endoscopic biopsy. Surgical resection is the primary treatment, but the prognosis of ASC is usually poorer than conventional squamous cell carcinoma. Lymph node metastasis is an independent prognostic factor after radical resection.

Factors affecting resolution of oculomotor nerve palsy following endovascular embolization of posterior communicating artery aneurysms.

PURPOSE: To investigate the effect of endovascular embolization of posterior communicating artery (Pcom) aneurysms on concomitant oculomotor nerve palsy (OMNP) and factors affecting the effect of treatment. MATERIALS AND METHODS: Patients with the Pcom aneurysms concomitant with OMNP were retrospectively enrolled for endovascular treatment of the aneurysms. All patients had the endovascular management. The clinical effect, degree of OMNP, size of the aneurysm, type of treatment, subarachnoid hemorrhage (SAH), and time from onset to treatment were analyzed on the resolution of OMNP. RESULTS: Ninety-six patients with 99 Pcom aneurysms were enrolled and treated endovascularly, with the success rate of 100%. Immediately after endovascular treatment, 75 aneurysms (75.75%) got complete occlusion, and 24 (24.24%) nearly complete occlusion. Followed up for 3-18 (mean 8.52±0.56) months, complete resolution of the OMNP was achieved in 63 patients (65.63%), partial resolution in 21 (21.88%), and non-recovery in the other 12 (12.50%). The degree of OMNP at onset, SAH, and time from onset to treatment were significantly (P<0.05) correlated with the resolution of OMNP. Univariate analysis revealed that younger age of the patient, degree of OMNP at onset, presence of subarachnoid hemorrhage, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP. Multivariate analysis revealed that the younger age, degree of OMNP at onset, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP. CONCLUSION: Endovascular embolization of Pcom aneurysms concomitant with OMNP can effectively improve the OMNP symptoms, especially for patients with moderate and a shorter history of OMNP. Younger age, degree of oculomotor nerve palsy at onset, and time from onset to treatment may significantly affect recovery of oculomotor nerve palsy.

Factors affecting resolution of oculomotor nerve palsy following endovascular embolization of posterior communicating artery aneurysms.

PURPOSE: To investigate the effect of endovascular embolization of posterior communicating artery (Pcom) aneurysms on concomitant oculomotor nerve palsy (OMNP) and factors affecting the effect of treatment. MATERIALS AND METHODS: Patients with the Pcom aneurysms concomitant with OMNP were retrospectively enrolled for endovascular treatment of the aneurysms. All patients had the endovascular management. The clinical effect, degree of OMNP, size of the aneurysm, type of treatment, subarachnoid hemorrhage (SAH), and time from onset to treatment were analyzed on the resolution of OMNP. RESULTS: Ninety-six patients with 99 Pcom aneurysms were enrolled and treated endovascularly, with the success rate of 100%. Immediately after endovascular treatment, 75 aneurysms (75.75%) got complete occlusion, and 24 (24.24%) nearly complete occlusion. Followed up for 3-18 (mean 8.52±0.56) months, complete resolution of the OMNP was achieved in 63 patients (65.63%), partial resolution in 21 (21.88%), and non-recovery in the other 12 (12.50%). The degree of OMNP at onset, SAH, and time from onset to treatment were significantly (P<0.05) correlated with the resolution of OMNP. Univariate analysis revealed that younger age of the patient, degree of OMNP at onset, presence of subarachnoid hemorrhage, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP. Multivariate analysis revealed that the younger age, degree of OMNP at onset, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP. CONCLUSION: Endovascular embolization of Pcom aneurysms concomitant with OMNP can effectively improve the OMNP symptoms, especially for patients with moderate and a shorter history of OMNP. Younger age, degree of oculomotor nerve palsy at onset, and time from onset to treatment may significantly affect recovery of oculomotor nerve palsy.

5-aminoimidazole-4-carboxamide ribonucleoside and AMP-activated protein kinase inhibit signalling through NF-κB.

Activation of nuclear factor-kappa B (NF-κB) is one of the most important pro-inflammatory mechanisms in disease. In this study, we show that 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), an intermediate in nucleoside metabolism, inhibits signalling by NF-κB in three cell types, including bovine aortic endothelial cells (BAEC). The block in the NF-κB signalling pathway occurred beyond degradation of IκB-α and movement of p65 into the nucleus of BAEC. There was, however, reduced binding of NF-κB from AICAR-treated cells to a κB-consensus oligonucleotide, suggesting that part of the mechanism was a reduction in NF-κB DNA-binding activity. Although AICAR is metabolized to ZMP and then adenosine, adenosine had no effect on activation of an NF-κB reporter. ZMP, however, activates the metabolic stress-sensing AMP-activated protein kinase (AMPK). Transfection of active AMPK into BAEC reduced NF-κB reporter activity compared with a kinase-dead mutant, suggesting that part of the ability of AICAR to inhibit NF-κB signalling is due to activation of AMPK. Inhibition of NF-κB signalling may be important in the anti-inflammatory action of drugs such as sulfasalazine and methotrexate, which led to the accumulation of AICAR within target cells.

Detection of cytomegalovirus reactivation in cancer patients receiving chemotherapy.

While increasing numbers of cytomegalovirus (CMV)-associated diseases are occurring in patients undergoing conventional chemotherapy, information regarding CMV reactivation is limited. This pilot study was conducted to investigate CMV reactivation induced by chemotherapy. Seven blood samples were collected from each of 15 patients with newly diagnosed malignant disease, at baseline before chemotherapy, and once every month after chemotherapy was commenced. CMV viral loads in leukocytes were determined by real-time PCR. Host responses to changes in viral loads were assessed by assaying CMV-specific IgG titres and tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma levels in each of the blood samples, and by scoring the number of CMV-associated clinical symptoms that developed. All except one patient experienced CMV reactivation during the course of chemotherapy, with the average viral load peaking after the third course of treatment. Titres of CMV-specific IgG increased in line with the increase in viral load. Plasma levels of TNF-alpha and IFN-gamma initially decreased from baseline, and then rose to peak levels at the same time as, or shortly after, the highest viral loads were recorded. Clinical symptoms potentially attributable to CMV infection appeared as the viral load increased. It was concluded that the incidence of CMV reactivation in patients receiving conventional chemotherapy is high. Reactivation is not asymptomatic, but was self-limiting in most of these cases. Increases in plasma TNF-alpha and IFN-gamma occur after reactivation, but not before.

Non-lethal Candida albicans cph1/cph1 efg1/efg1 transcription factor mutant establishing restricted zone of infection in a mouse model of systemic infection.

The cph1/cph1 efg1/efg1 Candida albicans mutant cells were non-lethal in a mouse model of systemic infection. We investigated in vivo proliferation and invasion of C. albicans cells in infected mice to elucidate the interaction between the host and the pathogen. Homogenates of kidneys from the mice infected with the wild-type and the mutant C. albicans cells yielded a mean of 2.1 x 10 7 CFU/g and 2.2 x 10 6 CFU/g, respectively. The kidneys from the mice infected with the wild-type cells showed extensive renal cortical necrosis associated with neutrophilic infiltration. There were also wild-type hyphal cells present in abundance. Hence, tubular necrosis leading to renal failure in the mice may be the cause of death. Although the cph1/cph1 efg1/efg1 mutant cells were not lethal, they were capable of establishing restricted zones of infection and colonization near the renal pelvis instead of simply being cleared by the immune system in mice.

Reliability of the Doppler pressure half-time method for assessing effects of percutaneous mitral balloon valvuloplasty.

The mitral valve areas determined by Doppler pressure half-time and by cardiac catheterization with use of the Gorlin formula were compared in 18 adult patients who underwent percutaneous mitral balloon valvuloplasty. Doppler measurements and catheterization were performed simultaneously before, immediately after and 24 to 48 h after valvuloplasty. A high correlation between Doppler- and catheterization-derived mitral valve areas was found before mitral valvuloplasty (r = 0.81, Y = 0.88X + 0.1, SEE = 0.11 cm2) and 24 to 48 h after valvuloplasty (r = 0.84, Y = 0.70X + 0.67, SEE = 0.20 cm2). In contrast, the correlation immediately after valvuloplasty was only moderate (r = 0.72, Y = 0.43X + 1.1, SEE = 0.49 cm2). The Doppler-derived mitral valve area (2.41 +/- 0.61 cm2) immediately after valvuloplasty was significantly larger than the catheterization-derived area (2.08 +/- 0.39 cm2, p less than 0.05). In conclusion, the Doppler echocardiographic measurement performed with the pressure half-time method may lead to significant error immediately after mitral balloon valvuloplasty, but clinically accurate measurement can be obtained 24 to 48 h after valvuloplasty.

Value of two-dimensional echocardiography in selecting patients and balloon sizes for percutaneous balloon mitral valvuloplasty.

The effect of valvular and subvalvular morphologic features and balloon size/mitral anulus size ratio on results of valvuloplasty were prospectively studied in 38 consecutive patients undergoing mitral valvuloplasty. The severity of valvular and subvalvular disease was graded echocardiographically from grade I to IV (mild to severe) for immobility, thickening, calcification of mitral leaflets and subvalvular thickening and fusion, yielding a maximal total score of 16. The diastolic mitral anulus diameter was measured in the apical four chamber view. After valvuloplasty, the mitral valve area increased from 0.9 +/- 0.3 to 2.2 +/- 0.5 cm2 (p less than 0.001) with increasing mitral regurgitation in 12 (32%) of the 38 patients. Multiple stepwise analysis revealed that the ratio of balloon size and annular size and the severity of subvalvular disease are two independent factors that correlated significantly with the mitral valve area after valvuloplasty (multiple r = 0.65, p less than 0.0002). One of 34 patients with mild subvalvular disease of grade III or less had an unsatisfactory increase in mitral valve area to less than or equal to 1.5 cm2, whereas 3 of 4 patients with severe (grade IV) subvalvular disease had a valve area less than or equal to 1.5 cm2 (p less than 0.002) after valvuloplasty. The increase in mitral regurgitation after valvuloplasty correlated significantly with the ratio of balloon to mitral anulus size and the severity of subvalvular disease (multiple r = 0.53, p less than 0.003). (ABSTRACT TRUNCATED AT 250 WORDS)

Anti-xenograft immune responses in alpha 1,3-galactosyltransferase knock-out mice.

Although originally generated to test the effect of eliminating the alpha-Gal epitope on HAR, it is becoming increasingly clear that GalT KO mice offer a convenient and inexpensive model to investigate many aspects of the anti-xenorgraft immune response. Clearly, not all aspects of anti-xenograft rejection responses are identical in mice and primates, which should be kept in mind when interpreting results of GalT KO mouse studies. However, with this and other mouse models it is possible to test a large number of variables, which is impractical for both logistical and financial reasons with primates. Furthermore the short gestation time and large litter size of mice means that genetic strategies targeting different aspects of the anti-xenograft immune response can be combined and subsequently tested to identify the optimal combination of genetic and therapeutic approaches to achieve long term xenograft survival. In this regard the GalT KO mouse has been and will continue to be a valuable small animal model for the study of all facets of xenograft rejection involving anti-Gal antibodies.

Inhibition of NF-kappaB activation by a dominant-negative mutant of IkappaBalpha.

The activity of the transcription factor NF-kappaB is tightly regulated by the inhibitory molecule IkappaBalpha. Upon stimulation, IkappaBalpha is rapidly degraded and NF-kappaB translocates to the nucleus to induce gene expression. The IkappaBalpha degradation is preceded by phosphorylation, suggesting that this event plays a role in the activation of NF-kappaB. In this study, we have mutated three potential phosphorylation sites in porcine IkappaBalpha and found that expression of the Ser32 mutant of IkappaBalpha (IS32A), but not Tyr42 or Ser262 mutants or wild-type IkappaBalpha, blocked the activation of NF-kappaB by TNF-alpha. These results suggest that the Ser32 residue, a potential casein kinase II phosphorylation site, is critical for NF-kappaB activation.

Changes in cell surface glycosylation in alpha1,3-galactosyltransferase knockout and alpha1,2-fucosyltransferase transgenic mice.

BACKGROUND: Inactivation of the alpha1,3-galactosyltransferase (GalT) gene by homologous recombination (knockout [KO] mice) and competition for the enzyme's N-acetyllactosamine substrate by transgenically expressed alpha1,2-fucosyltransferase (H-transferase) are two genetic approaches to elimination of the Gal alpha1,3Gal (alphaGal) epitope, which is the major xenoantigen in pigs against which humans have preformed antibodies. Such genetic manipulations often have unpredictable results. METHODS: A panel of 19 selected lectins was used to characterize the changes in cell surface glycosylation in GalT KO and H-transferase transgenic mice, compared with nontransgenic littermate controls. RESULTS: GalT KO mice showed complete elimination of the alphaGal epitope, as reported previously. Surprisingly, however, this was associated with only a modest increase in N-acetyllactosamine residues and had little other effect on the pattern of lectin binding. In contrast, the pattern of lectin binding to H-transferase transgenic mouse cells was more profoundly disturbed and indicated, in addition to the expected expression of H substance and suppression of the alphaGal epitope, that there was a marked reduction in alpha2,3-sialylation and exposure of the normally cryptic antigens, sialylated Tn and Forssman antigens. Similar changes in lectin reactivity with porcine aortic endothelial cells were induced by neuraminidase treatment. CONCLUSIONS: Lectins were able to bind underlying carbohydrate structures (sialylated Tn and Forssman antigens) that are normally cryptic antigens on H-transferase transgenic mouse spleen and cardiac endothelial cells, probably as a consequence of the reduction in the electronegativity of the cell surface due to reduced sialylation. As humans have preformed anti-Tn and anti-Forssman antibodies, it is possible that these structures may become targets of the xenograft rejection process, including hyperacute rejection.

Transgenic expression of human alpha1,2-fucosyltransferase (H-transferase) prolongs mouse heart survival in an ex vivo model of xenograft rejection.

BACKGROUND: The expression of human alpha1,2-fucosyltransferase (H-transferase, HT) has been proposed as an alternative strategy to alpha1,3-galactosyltransferase (GT) gene knockout, which is not currently feasible in pigs, to reduce the galactose-alpha1,3-galactose (Gal) epitope expression. HT expression has recently been shown in transgenic mice and pigs to significantly reduce Gal expression on a variety of cells; however, its ability to do so on endothelial cells and its effectiveness at prolonging xenograft survival are yet to be determined. METHODS: HT-transgenic, Gal knockout (Gal KO) mice, and mice containing both genetic modifications (HT-transgenic/Gal KO) were tested for H-substance and Gal expression on splenocytes and endothelial cells by flow cytometric analysis. In addition, the hearts of these mice were perfused ex vivo with 6% human plasma, and the effect on cardiac function was determined. RESULTS AND CONCLUSION: H-substance expression was detected on both splenocytes and endothelial cells of HT-transgenic mice. The level of H-substance expression was not affected by the presence or absence of GT in the cells, consistent with HT being dominant over GT. The ability of HT expression to reduce Gal expression was highly variable depending on the cell type. Gal expression on splenocytes was almost completely eliminated, whereas on endothelial cells, substantial Gal remained despite a 70% reduction. When perfused ex vivo with human plasma, hearts from HT-transgenic, Gal KO, and HT-transgenic/Gal KO mice demonstrated a similar prolongation in survival, compared with wild-type controls. Therefore, as far as hyperacute rejection is concerned, HT expression may be as effective as Gal KO in protecting against xenoantibody and complement mediated injury. However, the effect of residual Gal on non-hyperacute rejection responses remains to be determined.

Knock out of alpha1,3-galactosyltransferase or expression of alpha1,2-fucosyltransferase further protects CD55- and CD59-expressing mouse hearts in an ex vivo model of xenograft rejection.

BACKGROUND: Organs from transgenic animals with high-level endothelial expression of the human complement regulatory factors CD55 and CD59 are significantly protected from human complement-mediated injury. Elimination or reduction of the major xenoepitope alphaGal, achieved by knocking out the alpha1,3-galactosyltransferase gene (Gal KO) or expressing human alpha1,2-fucosyltransferase (H transferase or HTF), also affords protection, although to a lesser degree. In this study, we examined whether the protection provided by strong CD55 and CD59 expression can be augmented by the Gal KO or HTF modifications. METHODS: Hearts from four groups of mice (wild type, CD55/CD59, CD55/CD59/HTF, and CD55/CD59/Gal KO) were perfused ex vivo with 40% human plasma. Mean heart work for each group was compared over a 60-min period. RESULTS: Wild-type hearts ceased to function effectively within 15 min of plasma addition. CD55/CD59 hearts displayed prolonged survival and maintained approximately 10% maximum work at the end of perfusion. Introduction of Gal KO or HTF onto the CD55/CD59 background resulted in a further prolongation, with work maintained at 20-30% of the maximum level. CONCLUSIONS: We used an ex vivo model to demonstrate that eliminating alphaGal expression further prolongs the function of mouse hearts expressing high levels of CD55 and CD59. In addition, we showed that reducing alphaGal by expressing HTF is equally as effective in prolonging CD55/CD59 heart function as knocking out Gal transferase, thus providing a feasible strategy for translating these advances to the pig.

Renal xenografts from triple-transgenic pigs are not hyperacutely rejected but cause coagulopathy in non-immunosuppressed baboons.

BACKGROUND: The genetic modification of pigs is a powerful strategy that may ultimately enable successful xenotransplantation of porcine organs into humans. METHODS: Transgenic pigs were produced by microinjection of gene constructs for human complement regulatory proteins CD55 and CD59 and the enzyme alpha1,2-fucosyltransferase (H-transferase, HT), which reduces expression of the major xenoepitope galactose-alpha1,3-galactose (alphaGal). Kidneys from CD55/HT and CD55/CD59/HT transgenic pigs were transplanted into nephrectomised, nonimmunosuppressed adult baboons. RESULTS: In several lines of transgenic pigs, CD55 and CD59 were expressed strongly in all tissues examined, whereas HT expression was relatively weak and did not significantly reduce alphaGal. Control nontransgenic kidneys (n=4) grafted into baboons were hyperacutely rejected within 1 hr. In contrast, kidneys from CD55/HT pigs (n=2) were rejected after 30 hr, although kidneys from CD55/CD59/HT pigs (n=6) maintained function for up to 5 days. In the latter grafts, infiltration by macrophages, T cells, and B cells was observed at days 3 and 5 posttransplantation. The recipients developed thrombocytopenia and abnormalities in coagulation, manifested in increased clotting times and an elevation in the plasma level of the fibrin degradation product D-dimer, within 2 days of transplantation. Treatment with low molecular weight heparin prevented profound thrombocytopenia but not the other aspects of coagulopathy. CONCLUSIONS: Strong expression of CD55 and CD59 completely protected porcine kidneys from hyperacute rejection and allowed a detailed analysis of xenograft rejection in the absence of immunosuppression. Coagulopathy appears to be a common feature of pig-to-baboon renal transplantation and represents yet another major barrier to its clinical application.

Induction of hyperpyrexia by dihydrocurvularin, a metabolic product of Penicillium gilmanii.

The previously reported rise in rectal temperature that follows the intravenous injection of the mixture of metabolic products (extractable with ether from the Czapek Dox medium on which Penicillium gilmanii has grown) is due to a single compound, dihydrocurvularin. Intravenous injection of 1-10 micrograms of dihydrocurvularin into rabbits causes a rise of at least one degree in rectal temperature of rabbits in 2-8 h. The degree of temperature rise depends more on the individual rabbit than on the quantity of dihydrocurvularin injected. Treatment with lipopolysaccharide abolishes the ability of dihydrocurvularin to cause a rise in rectal temperature. Treatment with dihydrocurvularin, however, does not abolish the ability of lipopolysaccharide to induce a temperature response or a leukocytosis. Rabbits respond to repeated treatment with dihydrocurvularin with a rise in rectal temperature that is indistinguishable from that observed on their first injection. Treatment with dihydrocurvularin does not affect differential counts or the concentration of leukocytes or red blood cells in the circulatory system.