The effects of tourniquet use on blood loss in primary total knee arthroplasty for patients with osteoarthritis: a meta-analysis

Background

The tourniquet is a common medical instrument used in total knee arthroplasty (TKA). However, there has always been a debate about the use of a tourniquet and there is no published meta-analysis to study the effects of a tourniquet on blood loss in primary TKA for patients with osteoarthritis.

Methods

We performed a literature review on high-quality clinical studies to determine the effects of using a tourniquet or not on blood loss in cemented TKA. PubMed, Web of Science, MEDLINE, Embase, and the Cochrane Library were searched up to November 2018 for relevant randomized controlled trials (RCTs). We conducted a meta-analysis following the guidelines of the Cochrane Reviewer’s Handbook. We used the Cochrane Collaboration’s tool for assessing the risk of bias of each trial. The statistical analysis was performed with Review Manager statistical software (version 5.3).

Results

Eleven RCTs involving 541 patients (541 knees) were included in this meta-analysis. There were 271 patients (271 knees) in the tourniquet group and 270 patients (270 knees) in the no tourniquet group. The results showed that using a tourniquet significantly decreased intraoperative blood loss (P < 0.002), calculated blood loss (P < 0.002), and the time of operation (P < 0.002), but tourniquet use did not significantly decrease postoperative blood loss (P > 0.05), total blood loss (P > 0.05), the rate of transfusion (P > 0.05), and of deep vein thrombosis (DVT) (P > 0.05) in TKA.

Conclusions

Using a tourniquet can significantly decrease intraoperative blood loss, calculated blood loss, and operation time but does not significantly decrease the rate of transfusion or the rate of DVT in TKA. More research is needed to determine if there are fewer complications in TKA without the use of tourniquets.

A Novel CCM1/KRIT1 Heterozygous Nonsense Mutation (c.1864C>T) Associated with Familial Cerebral Cavernous Malformation: a Genetic Insight from an 8-Year Continuous Observational Study

Cerebral cavernous malformation (CCM) is a congenital vascular abnormality that predominantly affects the central nervous system, but that sometimes encroaches other vital tissues, including the retina, skin, and even liver. The familial form of CCM (FCCM) is considered to be an autosomal dominant disease with incomplete penetrance and variable expression, which is often attributed to mutations in three genes: CCM1, CCM2, and CCM3. We screened a Chinese family diagnosed with FCCM by using Sanger sequencing. A 29-year-old male proband with cutaneous angiomas was pathologically diagnosed but presented with an atypical form of CCM as revealed by magnetic resonance imaging (MRI) findings, prompting further clinical evaluation and genetic analyses of him and his immediate family. We performed continuous observation over an 8-year period using MRI gradient echo imaging and susceptibility-weighted imaging of these individuals. Sanger sequencing of the CCM1, CCM2, and CCM3 genes identified a novel heterozygous nonsense nucleotide transition (c.1864C>T; p.Gln622X) in exon 17 of the CCM1/KRIT1 gene; this mutation was predicted to cause a premature stop codon (TAG) at nucleotides 1864 to 1866 to generate a truncated Krev interaction trapped 1 (Krit1) protein of 621 amino acids. During this long-term observational study, one of the enrolled family members with neurological deficits progressed to a stage indicative of brain surgery. This study provides a new CCM gene mutation profile, which highlights the significance of genetic counseling for individuals suspected of having this condition.

Identification of a Novel Deletion Mutation (c.1780delG) and a Novel Splice-Site Mutation (c.1412-1G>A) in the CCM1/KRIT1 Gene Associated with Familial Cerebral Cavernous Malformation in the Chinese Population

Cerebral cavernous malformation (CCM) is a congenital vascular anomaly predominantly located within the central nervous system. Its familial forms (familial cerebral cavernous malformation (FCCM)), inherited in an autosomal dominant manner with incomplete penetrance, are attributed to mutations in CCM1/KRIT1, CCM2/MGC4607, and CCM3/PDCD10 genes. To date, little is known about the genetic alterations leading to FCCM in the Chinese population. We aimed to investigate the genetic defect of FCCM by DNA sequencing in Chinese families. This study enrolled five Chinese families with FCCM. All index cases underwent surgical treatment and were diagnosed with CCM by pathology; their relatives were diagnosed based on radiological and/or pathological evidence. Genomic DNA was extracted from peripheral blood and amplified using polymerase chain reaction (PCR) for DNA sequencing. The five families comprised a total of 21 affected individuals: 12 of these were symptomatic, and 9 were asymptomatic. Sequence analyses in the index patients disclosed three heterozygous loss-of-function mutations in the CCM1/KRIT1 gene in three families, respectively: a novel deletion mutation (c.1780delG; p.Ala594HisfsX67) in exon 16, a novel splice-site mutation (c.1412-1G>A) in the splice acceptor site in intron 13, and a previously described 4-bp deletion (c.1197_1200delCAAA; p.Gln401ThrfsX10) in exon 12. All of these mutations are predicted to cause a premature termination codon to generate a truncated Krev interaction trapped 1 (Krit1) protein. These mutations segregated in affected relatives. Our findings provided new CCM1 gene mutation profiles, which help to elucidate the pathogenesis of FCCM and will be of great significance in genetic counseling.

[Anaplastic lymphoma kinase fusion gene expression, clinical pathological characteristics and prognosis in 95 Chinese patients with non-small cell lung cancer]

OBJECTIVE

To examine the prevalence of anaplastic lymphoma kinase (ALK) fusion gene in Chinese patients with non-small cell lung cancer (NSCLC).

METHODS

In this study, 95 patients with NSCLC and corresponding clinical information and formalin-fixed paraffin-embedded (FFPE) tissue blocks were included. Hematoxylin & eosin (HE) staining, conventional ALK immunochemistry (IHC) staining and intercalated antibody-enhanced polymer (iAEP) IHC staining, and dual-color split fluorescence in situ hybridization (FISH) for ALK fusion gene were performed.

RESULTS

Eight ALK-positive cases were detected using anti-ALK immunohistochemistry with the iAEP method, and FISH analyses revealed 4 patients of them who harbored the ALK fusion gene (4.2%, 4/95), including 2 cases of female patients with solid signet-ring cell adenocarcinoma and 2 cases of male patients with adenosquamous carcinoma. The positive cases were all non-smokers without EGFR/KRAS mutations. Furthermore, the positive cases all survived, and the overall postsurgery survival time of 2 cases was more than 5 years.

CONCLUSION

ALK IHC with the iAEP method is better than conventional ALK IHC, and the percentage of the positive cells is more important than that of the intensity. ALK translocations were infrequent in the entire NSCLC patient population (<5%) with better prognosis.

Quantification of alternative splicing variants of human telomerase reverse transcriptase and correlations with telomerase activity in lung cancer

Telomerase plays important roles in the development and progression of malignant tumors, and its activity is primarily determined by transcriptional regulation of human telomerase reverse transcriptase (hTERT). Several mRNA alternative splicing variants (ASVs) for hTERT have been identified, but it remains unclear whether telomerase activity is directly associated with hTERT splicing transcripts. In this study, we developed novel real-time PCR protocols using molecular beacons and applied to lung carcinoma cell lines and cancerous tissues for quantification of telomerase activity and three essential hTERT deletion transcripts respectively. The results showed that lung carcinoma cell lines consistently demonstrated telomerase activity (14.22–31.43 TPG units per 100 cells) and various hTERT alternative splicing transcripts. For 165 lung cancer cases, telomerase activity showed significant correlation with tumor differentiation (poorly->moderately->well-differentiated, P<0.01) and with histotypes (combined small cell and squamous cell carcinoma>squamous cell carcinoma>adenosquamous carcinoma>adenocarcinoma, P<0.05). Although the overall hTERT transcripts were detected in all the samples, they were not associated with telomerase activity (r = 0.092, P = 0.24). Telomerase activity was significantly correlated with the transcriptional constituent ratio of α-deletion (r = -0.267, P = 0.026), β-deletion (r = -0.693, P = 0.0001) and γ-deletion (r = –0.614, P = 0.001). The positive rate and average constituent ratio of β-deletion transcripts (92.12%, 0.23) were higher than those of α-deletion (41.82%, 0.12) or γ-deletion (16.36%, 0.18) transcripts. The combined small-cell and squamous cell carcinomas expressed less deletion transcripts, especially β-deletion, than other histotypes, which might explain their higher telomerase activity. In conclusion, the molecular beacon-based real-time PCR protocols are rapid, sensitive and specific methods to quantify telomerase activity and hTERT ASVs. Telomerase activity may serve as a reliable and effective molecular marker to assist the evaluation of histological subtype and differentiation of lung carcinomas. Further studies on hTERT deletion splicing transcripts, rather than the overall hTERT transcripts, may improve our understanding of telomerase regulation.

Detection of telomerase activity in cultured cells and tumor tissue of lung carcinoma by modified telomeric repeat amplification protocol

Telomerase activity is found in various cell types including stem cells, neoplastic cells, and immortalized cells, suggesting a close association with their proliferation capacity. The telomeric repeat amplification protocol (TRAP) has been traditionally used to detect semi-quantitatively the telomerase activity by polyacrylamide gel electrophoresis (PAGE), which is difficult to apply for large scale analysis because of laborious post-PCR manipulation and potential carryover contamination. In the present study, a specific reverse primer was designed and the TRAP protocol was adapted to either PAGE or real-time PCR assay. Using cultured cell lines, the real-time TRAP showed a dramatic improvement in the reliability and accuracy of quantitation of telomerase activity and was able to discriminate the A549 cells from hundreds-fold human embryonic lung cells. Using clinical samples of 60 lung cancers and 8 inflammatory lesions, the real-time TRAP was also superior in quantitation, high-throughput capability and standardization. Our modified real-time TRAP should be applicable for the detection of telomerase activity for the initial screening and progression monitoring of lung cancer patients. Our approach is particularly useful when only limited clinical specimen is available, such as fine needle aspiration or other cytological specimens that may contain only a small number of tumor cells.

[A clinicopathologic study on complications of orthotopic liver transplantation in 54 patients with chronic hepatitis B virus infection]

OBJECTIVE

To study the complication incidence of 54 patients with chronic HBV infection following their orthotopic liver transplantation (OLT), and factors associated with HBV recurrence and hepatocellular carcinoma (HCC) recurrence or metastasis post-OLT.

METHODS

The light-microscopic appearance of hepatic allograft biopsies in 54 patients with chronic HBV infection following OLT was examined. The related clinical data were analyzed. The incidence and occurrence time of post-OLT complications were studied. Furthermore, the relationship between recurrent type B viral hepatitis and acute rejection and the relationship among HCC recurrence/metastasis, acute rejection, the tumor diameter, and the portal vein invasion were particularly studied.

RESULTS

The frequent complications of patients with chronic HBV infection following OLT were acute rejection [38(70.4%); occurrence time: 5-365 d], chronic rejection [ 1(1.9%); occurrence time: 10.7 months],bile duct complications [24(44.4%); occurrence time: 7-940 d], HBV recurrence [7(13.0%); occurrence time: 1-540 d], HCV infection [3(5.6%); occurrence time: 60 d, 60 d, 33 months], CMV infection [8(14.8%); occurrence time: 67-90 d], and HCC recurrence or metastasis [17(31.5%); occurrence time: 2-41 months]. At the end of 1 year post-OLT, 95% of patients with post-hepatitis B cirrhosis were alive; At the end of 3 years post-OLT, 85% of patients with post-hepatitis B cirrhosis were alive. However, at the end of 1 year post-OLT, 67.6% of patients with post-hepatitis B HCC were alive; At the end of 3 years post-OLT, 50% of patients with post-hepatitis B HCC were alive. The number of acute rejection episodes in patients with recurrent HBV infection and that without recurrent HBV infection was (0.86+/-1.46) time/patient and (1.07+/-0.90) time/patient respectively(P>0.05); the number of moderate acute rejection episodes(RAI>or=score 4) in patients with recurrent HBV infection and that without recurrent HBV infection was (0.29+/-0.49) time/patient and (0.50+/-0.63) time/patient(P>0.05); Incidence of patients with >or=3 episodes of acute rejection in patient with recurrent HBV infection and that without recurrent HBV infection was 14.3% and 10.6%(P>0.05). Furthermore, the number of acute rejection episodes in patients with HCC recurrence or metastasis and that without HCC recurrence or metastasis was (1.12+/-0.93) time/patient and (1.06+/-1.39) time/patient respectively(P>0.05); the number of moderate acute rejection episodes(RAI>or=score 4) in patients with HCC recurrence or metastasis and that without HCC recurrence or metastasis was (0.65+/-0.79) time/patient and (0.65+/-1.06) time/patient respectively(P>0.05); Incidence of patients with >or=3 episodes of acute rejection in patient with HCC recurrence or metastasis and that without HCC recurrence or metastasis was 5.9% and 17.6% respectively(P>0.05). The tumor diameter in patients with HCC recurrence or metastasis was (6.72+/-3.40)cm, however, that in patients without HCC recurrence or metastasis was (3.55+/-2.17)cm(P=0.004 7).The incidence of Portal vein invasion in patients with HCC recurrence or metastasis and that without HCC recurrence or metastasis was 68.75% and 33.3% respectively(P=0.006).

CONCLUSION

There was no significant difference among HBV recurrence and acute rejection post-liver transplantation in patients with chronic HBV infection. There was no significant difference between HCC recurrence and acute rejection. The tumor diameter of patients with HCC recurrence or metastasis was significantly greater than that of no HCC recurrence or metastasis. The portal vein invasion of patients with HCC recurrence or metastasis was significantly frequent than that of no HCC recurrence or metastasis.

[P2Y purinergic receptor activated PI-3K/Akt signaling pathway in regulation of growth and invasion of prostatic cancer]

OBJECTIVE

To investigate P2Y purinergic receptor activated PI-3K/Akt signaling pathway in the regulation of growth and invasion of prostate cancer in vitro.

METHODS

Western blot was used to detect phosphorylation of Akt (a downstream target molecule of PI-3K) by P2Y receptor agonist in 1E8 cells (a highly metastatic subclone derived from PC-3 prostatic cancer cell line). Cell counts, flow cytometry, Matrigel invasion assay, wound healing assay and gelatin zymography were used to detect changes of biological behaviors of 1E8 cells after P2Y receptor activation.

RESULTS

AMP-PNP, one non-hydrolysis ATP analogue and P2Y receptor agonist, induced significant phosphorylation of Akt in a time- and dose-dependent manner in IE8 cells. LY294002, a specific inhibitor of PI-3K, effectively blocked Akt phosphorylation induced by AMP-PNP. Continuous exposure to AMP-PNP induced significant growth inhibition of 1E8 cells (inhibition rate at 50.2% at the 8th day), and this inhibition was mainly due to an arrest at S phase of the cell cycle (the S phase fraction of AMP-PNP treated cells was 22.3% higher than that of the control). Application of LY294002 did not reverse the growth inhibition effect of AMP-PNP. Matrigel invasion assay showed that AMP-PNP stimulation increased invasive ability of 1E8 cells, and this effect was effectively blocked by LY294002. No significant changes in the activation of MMP-2 and MMP-9 were detected by gelatin zymography, although wound healing assay showed 21.2% increase in cell migration after AMP-PNP treatment.

CONCLUSIONS

PI-3K/Akt signaling pathway participates in P2Y receptor-stimulated prostate cancer invasion by enhancing cell motility, rather than up-regulating MMP-2 and MMP-9 activities. PI-3K signaling pathway plays an important role in prostate cancer proliferation, but is not involved in P2Y receptor mediated growth inhibition.

[Status and clinicopathologic implication of epidermal growth factor receptor mutation in non-small cell carcinoma of lung]

OBJECTIVE

To investigate mutations of epidermal growth factor receptor (EGFR) exon 19 and 21 in non-small cell lung carcinoma and to explore their clinicopathological correlations.

METHOD

DNA was extracted from the excised tumor specimens of 66 non-small cell lung carcinoma patients by traditional phenol-chloroform and ethanol precipitation. Exons 19 and 21 were amplified by polymerase chain reaction (PCR), followed by direct sequencing in both sense and antisense directions.

RESULTS

EGFR somatic mutations were present in 11 of 66 patients (16.7%), including 7 cases of in-frame deletion involving exon 19 and 4 cases of amino acid substitution involving exon 21. Mutations were more frequently observed in women (9/34, 26.5%) than in men (2/32, 6.3%), in adenocarcinomas (10/43, 23.3%) than squamous (0/13) and adenosquamous carcinomas (1/10). There was no difference in the mutation rates between smokers and non-smokers. Those with adenocarcinoma with bronchiolo-alveolar carcinoma (BAC) components had higher frequency of EGFR mutation (6/11) than those without non-BAC element (4/32, 12.5%).

CONCLUSIONS

The mutations appear to occur in highly selected subgroups of lung cancer patients: adenocarcinomas with BAC components and patients of the female gender. The results may offer practical approach to the rapid identification of lung cancer patients who likely respond to EGFR inhibitor therapy.

[Detection of Mycobacterium tuberculosis DNA in sarcoidosis samples using real-time fluorescence polymerase chain reaction]

OBJECTIVE

To study the role of Mycobacterium tuberculosis in the pathogenesis of sarcoidosis.

METHODS

Archival material of 22 patients with a histologic diagnosis of sarcoidosis were retrieved. Real-time fluorescent polymerase chain reaction (PCR) was used to detect DNA fragments of the complex-specific insertion sequence IS6110 of Mycobacterium tuberculosis in formalin-fixed and paraffin-embedded biopsy samples.

RESULTS

Among the 22 samples studied, Mycobacterium tuberculosis DNA was detected in 11 cases. The sequence of PCR amplified IS6110 DNA fragments completely matched with the related sequence in Mycobacterium tuberculosis gene.

CONCLUSIONS

Mycobacterium tuberculosis DNA is identified in a certain proportion of patients with a clinicopathologic diagnosis of sarcoidosis. Mycobacterium tuberculosis may be an important etiologic agent, at least in some of these patients.

[Status and clinical implication of c-kit and PDGFRA mutations in 165 cases of gastrointestinal stromal tumor (GIST)]

OBJECTIVE

To investigate the status of c-kit and PDGFRA mutations of GIST in a the large sample of Chinese patients.

METHOD

One hundred and sixty-five cases were evaluated for the presence of c-kit and PDGFRA mutations. Exon 9, 11, 13, 17 of c-kit and exon 12, 18 of PDGFRA were analyzed by PCR amplification and direct sequencing.

RESULTS

Immunohistochemical demonstrations of KIT (CD117) were seen in 94% of the cases (155/165). Overall, c-kit mutations were identified in 76.1% (118/155) of CD117 positive cases: 67.1% (104/155) involving exon 11, 7.1% (11/155) involving exon 9, 1.3% (2/155) involving exon 13 and 0.6% (1/155) involving exon 17. The c-kit exon 11 mutations were mostly heterogeneous and clustered in the classic "hot spot" at the 5' end of the exon, including in-frame deletion and point mutation. The second "hot spots" were internal tandem duplications (ITD) at the 3' end of the exon, which were associated with female patient, older age, stomach location and low mitotic counts. The exon 9 mutations correlated with a distinct subset of GISTs involving the small bowel of young male patients. A new point mutation of L641P was identified in exon 13. PDGFRA mutations were present in 50% (5/10) of CD117-negative GISTs, all involving exon 18 with the majority of mutations being D842V. One novel in-frame deletion of IMHD mutation at codon 843 - 846 with S847T was identified. GISTs with PDGFRA mutations were often larger tumors arising from the omentum/mesentery of young male patients with high risk of aggressive behavior.

CONCLUSIONS

The vast majority of GISTs in this study harbored c-kit and PDGFRA mutations, there were non-random relations between the gene mutation patterns and the locations of GISTs. It appears that Chinese GIST patients have some unique mutation patterns. It is necessary to evaluate the gene mutations status of GISTs to guide target therapy.

[PTCH gene mutations in odontogenic keratocysts]

OBJECTIVE

To investigate the frequency, type and distribution of PTCH mutations in odontogenic keratocysts (OKC) and to analyze the molecular pathological relationship between sporadic OKC and OKC associated with nevoid basal cell carcinoma syndrome (NBCCS).

METHODS

Genomic DNA was extracted from 8 cases of OKC lesions (4 sporadic OKCs and 4 NBCCS-related OKCs). PTCH gene mutations were detected by PCR-direct sequencing.

RESULTS

Six novel PTCH mutations were identified in 6 out of 8 cases (2 sporadic and 4 NBCCS-related OKCs). Two of these were missense mutations leading to substitution of an amino acid residue respectively. The other 4 mutations were identified as insertion or deletion ranging from one single base to 7 bases, three of which caused frame-shift leading to premature truncation of PTCH protein and one resulted in an insertion of 2 amino acid residues. All these identified mutations were novel and have not been previously described.

CONCLUSIONS

PTCH gene mutation is a common event in NBCCS-related OKCs and could also be detected in some sporadic OKCs. Abnormalities of PTCH gene may be involved in the pathogenesis of OKC.

Multiple organ infection and the pathogenesis of SARS

After >8,000 infections and >700 deaths worldwide, the pathogenesis of the new infectious disease, severe acute respiratory syndrome (SARS), remains poorly understood. We investigated 18 autopsies of patients who had suspected SARS; 8 cases were confirmed as SARS. We evaluated white blood cells from 22 confirmed SARS patients at various stages of the disease. T lymphocyte counts in 65 confirmed and 35 misdiagnosed SARS cases also were analyzed retrospectively. SARS viral particles and genomic sequence were detected in a large number of circulating lymphocytes, monocytes, and lymphoid tissues, as well as in the epithelial cells of the respiratory tract, the mucosa of the intestine, the epithelium of the renal distal tubules, the neurons of the brain, and macrophages in different organs. SARS virus seemed to be capable of infecting multiple cell types in several organs; immune cells and pulmonary epithelium were identified as the main sites of injury. A comprehensive theory of pathogenesis is proposed for SARS with immune and lung damage as key features.

[c-kit and PDGFRA mutations in 60 cases of gastrointestinal stromal tumors (GISTs)]

OBJECTIVE

To explore the status of activating mutations of c-kit and PDGFRA in GIST of Chinese patients.

METHODS

Sixty GISTs, confirmed by immunoreactivity of CD117, CD34, SMA, S-100 and Desmin, were evaluated for the presence of c-kit exons 9, 11, 13 and 17 mutations, and PDGFRA exons 12 and 18 mutations. The PCR products were sequenced directly for mutations, using DNA extracted from paraffin-embedded tissue.

RESULTS

53% of the tumors were located in the stomach, 22% in the small bowel, 8% in the colo rectum, 2% in the esophagus and 15% in the extragastrointestinal tract. Immunohistochemical demonstrations of c-kit (CD117) were seen in 90% cases. Overall, c-kit mutations were detected in 63.3% of patients as follows: 58.3% in exon 11, 3.3% in exon 9, 1.7% in exon 13 and none in exon 17. The types of c-kit exon 11 mutations were mostly heterogeneous and clustered in the classic "hot spot" at the 5' end of exon 11, 42.9% being point mutation and in-frame deletion at Codon 557-560. 14.3% of cases showed internal tandem duplications (ITD) at the 3' end of exon 11 in a region of a second hot spot for c-kit mutations. Interestingly, these cases were associated with female predominance, stomach location and occurrence in older patients. The present study failed to identify a significant association between c-kit mutation status and risk of aggressive behavior in GISTs. Exon 9 mutations consisted of ITP of six nucleotides encoding Ala-Tyr. A new point mutation of L641P was revealed in exon 13. PDGFRA mutations were found in 5% of all the 60 cases with none of the positive cases expressed detectable KIT protein. The type of mutation was the commonest point mutation of D842V of exon 18.

CONCLUSION

Most KIT expressing GIST show c-kit mutations that are preferentially located within the classic hot spot of exon 11. A second hot spot -ITD at the 3' end of exon 11 seems to associate with a subgroup of gastric GISTs in older females. c-kit exons 9, 13 and 17 mutations are rare events in GIST of China. PDGFRA oncogenic mutations are more likely seen in KIT-negative GISTs arising in the peritoneal surface and have an unfavorable clinical course.

Severe acute respiratory syndrome associated coronavirus is detected in intestinal tissues of fatal cases

OBJECTIVES

A significant percentage of confirmed severe acute respiratory syndrome (SARS) patients experienced gastrointestinal symptoms, and the viral sequence was detectable in the stool of most patients. At present, the knowledge of the pathology of the digestive system in SARS patients is limited. Because a resurgence of the SARS epidemic is constantly possible, there is an urgent need to understand the involvement of the digestive system in this new disease.

METHODS

We performed seven SARS autopsies in which samples of alimentary tract and digestive glands were examined with routine pathology, electron microscopy (EM), in situ hybridization (ISH), immunohistochemistry, and real-time polymerase chain reaction (PCR).

RESULTS

The main histopathological finding was atrophy of the mucosal lymphoid tissue. A few mucosal epithelial cells and lymphocytes in the intestine were positively stained for coronavirus with ISH. SARS-coronavirus (CoV)-like particles were found in the mucosal epithelial cells under EM and mild focal inflammation was detected in the alimentary tract. One patient who experienced severe diarrhea had pseudomembranous enteritis of the ileum. Fatty degeneration and central lobular necrosis were observed in the liver. No evidence of direct viral infection was found in the esophagus, the stomach, the salivary gland, the liver, or the pancreas.

CONCLUSIONS

In addition to the lungs, the gastrointestinal tract is another target of SARS-CoV infection, as the intestinal epithelial cells and mucosal lymphoid tissue are infected. The findings provide possible explanations for the gastrointestinal symptoms and the presence of virus in the stool of SARS patients.

[Activation of HIF-1 by bFGF in breast cancer: role of PI-3K and MEK1/ERK pathways]

OBJECTIVE

To explore the mechanism of basic fibroblast growth factor (bFGF)-mediated hypoxia inducible factor (HIF-1) activation and the down-stream signaling pathways involved.

METHODS

Human breast cancer cells of the line T47D were cultured and lysed to extract the total protein in the supernatant. The amounts of extracellular signal kinase 1/2 (ERK1/2), Akt, p38, and beta-tubulin were measured. T47D cells were inoculated into a 24-well plate, co-transfected with luciferase vector OB-HRE containing HIF-1 functional sequence (HRE) and pRL-SV40 (as inner marker), pretreated with SU5402, inhibitor of FGFR1, SB203580, inhibitors of PI-3K, PD98059, inhibitors of MEK1, or LY294002, inhibitors of p38, treated with basic fibroblast growth factor (bFGF), and then lysed. The amounts of ERK1/2, Akt, p38, and beta-tubulin were measured. Western blotting was used to detect the HIF-1alpha level in total protein. Dual luciferase assay was used to analyze the transactivity of HIF-1. The firefly/renilla luciferase ratio was measured to access the transcription activity of HIF-1. Western blotting was used to detect the expression of HIF-1alpha protein and phosphorylated Akt, ERK1/2 and p38 in whole cell extract.

RESULTS

After the addition of bFGF Western blotting showed that the and phosphorylation of Akt, ERK1/2 and p38 in the T47D cells were increased time- and dose-dependent manner, and dual luciferase assay showed that the fluorescent intensity was increased, signifying the increase of expression of HIF-1alpha protein. Ten minutes after the addition of CHX the expression of HIF-1alpha protein began to be decreased and ceased 90 minutes after. SU5402 remarkably dose-dependently blocked the bFGF-induced phosphorylation of ERK1/2, Akt and p38. 15 micromol/L LY294002 completely blocked the bFGF-induced phosphorylation of Akt. 5 micromol/L PD98059 blocked 80% of the bFGF-induced phosphorylation of ERK1/2. 10 approximately 20 micromol/L SB203580 basically blocked the bFGF-induced phosphorylation of p38. SU5402 and LY294002 100% inhibited the bFGF-induced expression of HIF-1alpha protein. However, PD98059 and SB203580 did not significantly influence the expression of HIF-1alpha protein induced by bFGF. Luciferase assay showed that SU5402 and PD98059 inhibited the bFGF-induced transcription activity of HIF-1 by 94.8% and 81.7% respectively. LY294002 not only completely inhibited the bFGF-induced transcription activity of HIF-1 but also inhibited the basic transcription of HIF-1, and SB203580 did not significantly influence the transcription activity of HIF-1.

CONCLUSION

bFGF activates HIF-1 via the PI-3K/Akt and MEK1/ERK pathways that co-operatively and differentially regulate this process with PI-3K/Akt pathway playing a more important role.

[Gene detection of severe acute respiratory syndrome-related coronavirus]

OBJECTIVE

To develop a newly real-time RT-polymerase chain reaction assay for severe acute respiratory syndrome (SARS) related coronavirus in human whole blood.

METHODS

A pair of primers and a probe (molecular beacon) had been designed that were specific for the recognition of a highly conservative region between 15 301 and 15 480 of the SARS-related coronavirus polymerase gene sequences obtained from GenBank (G130027616).

RESULTS

In the real-time RT-PCR assay, the extent of SARS related coronavirus amplification was measured in terms of the increase in fluorescence during the amplification process. The 145 bp fragment of PCR product was further confirmed by conventional PCR assay and proved by DNA sequencing to be identical to the target sequence to which the probe was hybridized.

CONCLUSION

This assay has a broad application for clinical diagnosis and surveillance investigation.

[A novel Krit-1 mutation in Han family with cerebral cavernous malformation]

OBJECTIVE

To detect the mutations of Krit-1 gene that cause familial cerebral cavernous malformation (CCM) in the Han ethnic origin.

METHODS

The subjects were hospitalized in the Department of Neurosurgery, Tiantan Hospital affiliated to Capital University of Medical Sciences. Two families (A and B) and 8 apparently sporadic individuals affected with CCM were screened for mutations of Krit-1 gene. Members of the family CCM have a wide range in age of onset with seizures, headaches and skin lesions. The gene was screened by PCR amplification of 16 exons and mutation was detected by direct sequencing.

RESULTS

In family A samples, analysis of the Krit-1 gene revealed a new point mutation in exon 14 [a heterozygous C to G transition at nucleotide 1 289 (counting from the start codon or nt 2 308 counting from the first nt of the mRNA, aligned according to Gene Bank AF388384)] which predicts the substitution of a premature termination codon for Serine at codon 430 (S430X), belonging a nonsense point mutation. No mutation was identified in one of family A members as well as in any of the sporadic individuals with the exception of a single nucleotide polymorphism.

CONCLUSIONS

Report the first family in the Han with CCM having a novel mutation in the CCM1 gene on the continent of Asia. The newly identified mutation creates a premature termination codon and is predicted to produce a truncated Krev1 interaction-trapped 1 protein, KRIT1. This result allows efficient presymptomatic molecular diagnosis.

[Down-regulation of metastatic phenotype in human melanoma cells by controlled expression of anti-sense matrix metalloproteinase 9]

OBJECTIVE

To investigate the correlation between matrix metalloproteinase 9 (MMP-9) expression and tumor invasion and metastasis as well, and to explore the potential application of controlled expression of target gene in tumor gene therapy.

METHODS

One self-contained tetracycline-regulated retroviral vector containing anti-sense cDNA of MMP-9 was constructed and transfected into a metastatic human melanoma cell line WM451 which expressed a high level of MMP-9. Techniques such as growth rate measurment, MTT assay, (3)H-thymidine incorporation, colony forming ability in soft agar, invasion assay in Boyden chamber, as well as zymography and Western blot were applied to analyze the expression of MMPs and behaviors of tumor cells in vitro before and after gene transfection. Tumorigenecity and spontaneous metastasis were tested in nude mice.

RESULTS

In the presence of exogenous tetracycline, the transfected antisense MMP-9 did not affect the endogenous level of MMP-9 in WM451 cells, and showed no significant changes in cell behaviors in comparison with that of the vector-transfected control cells. Nevertheless, withdrawal of tetracycline from the medium caused a significant down-regulation of expression and activity of MMP-9. The capacity of cell growth in vitro, colony forming ability in soft agar, invasion through Matrigel all were inhibited remarkably when compared with the controls. Spontaneous metastasis in nude mice was significantly inhibited.

CONCLUSIONS

Transfection of anti-sense MMP-9 can down-regulate the invasion and metastasis of melanoma cells both in vitro and in vivo, further clarifying the important role of MMP-9 in tumor progression.

[Controlled expression of matrix metalloproteinase 9 promotes expression of invasive phenotype of human melanoma cells]

OBJECTIVE

To investigate the correlation between matrix metalloproteinase 9 (MMP-9) expression and tumor metastasis, and explore the potential application of controlled expression of target gene in tumor gene therapy.

METHODS

One self-contained tetracycline-regulated retroviral vector containing sense cDNA of MMP-9 was constructed and transfected into an early-stage human melanoma cell line WM35, which did not express MMP-9. In vitro tests such as growth rate, MTT method, 3H-thymidine incorporation, colony forming ability in soft agar, in vitro invasion assay in Boyden chambers, as well as zymography and Western Blot experiment were used to analyze expression of MMPs and in vitro behavior of tumor cells before and after gene transfection.

RESULTS

In the presence of exogenous tetracycline, the expression of the transfected MMP-9 were under detectable level and no significant changes in cell behaviors were found when compared with vector-transfected control cells. But when the tetracycline was withdrew from the medium, the expression and activity of MMP-9 were significantly increased. The capacity of in vitro growth, colony forming ability in soft agar, invasion through Matrigel were enhanced remarkably.

CONCLUSION

Transfection of sense MMP-9 can enhance growth and invasion of melanoma cells, further confirming its important role in tumor invasion and metastasis.

[Effects of two variants of ING1 expression on tumor cell growth regulation]

OBJECTIVE

To study effects of alternative transcripts of ING1 transfection on human cancer cell lines.

METHODS

p47/ING1A and p33/ING1B expression vehicles were constructed and introduced into a human breast cancer cell line MCF-7 and a human lung cancer cell line PAa, both expressing wild-type p53 protein. Growth characteristics of the transfectants and potentially related genes were analyzed.

RESULTS

The levels of p47/ING1A and p33/ING1B protein elevated respectively in tumor cells of MCF-7 and PAa after transfected with p47/ING1A and p33/ING1B, and the latter was much higher than that of the former. Ectopic overexpression of p33/ING1B effectively blocked tumor cell growth and arrested cells in the G(0) approximately G(1) phase of the cell cycle (P < 0.01), while p47/ING1A gave no effect on cell growth or cell cycle. Tumor cells overexpressing p33/ING1B contained more p21(WAF1) protein than that of the control cells, with undisturbed p53 protein level.

CONCLUSIONS

Expression of two different transcripts of ING1 may have different effects on tumor cell growth. p33/ING1B may cooperate with p53 in stimulating expression of p21(WAF1) gene, thus to arrest cell cycle and to inhibit tumor cell growth. p33/ING1B may be considered to be a candidate as a partner of p53 in gene therapy.

Monocyte chemoattractant protein-1 mRNA in human intracranial aneurysm walls

OBJECTIVE

To investigate the pathological course in intracranial aneurysms.

METHODS

Normal intracranial artery tissue (cortex fistulization) from 1 case, ruptured aneurysms tissuses from 11 cases, unruptured aneurysm tissues from 2 cases were obtained by neurosurgical excision. Routine HE staining was used to observe histological characteristics. In situ hybridization was used to observe the expression of the monocyte chemoattractant protein-1 (MCP-1) mRNA in the walls of the normal artery and aneurysms.

RESULTS

By the HE staining showed that the wall of the ruptured aneurysms (10 cases) and unruptured ones (2 cases) had increased intima and connectivum extima. The fibroblast in the intima was arrayed in the disorder. Monocyte-like cells can be seen in the whole aneurysm wall. In one case aneurysms wall (ruptured) glass-like fiber structure was left over, few cells could be seen. In 9 cases, mural thrombus was found. The thrombus represented with organization. In situ hybridization, MCP-1 mRNA was not detectable in the normal artery. The hybridization signal could be observed in the ruptured aneurysms (10 cases) and unruptured ones (2 cases) often in the intima. MCP-1 mRNA appeared to be expressed by fibroblast cells in its cytoplasm. Monocyte-like cells had little cytoplasm, and the signal was seldom seen. The hybridization signal was discontinuous in the intima, MCP-1 mRNA expressed where fibroblast and monocyte-like cells assembled. One ruptured aneurysm had no signal because there were no cells only glass-like fiber. Mural thrombus showed upregulated hybridization signal in the cytoplasm of fibroblasts, phlogocytes and endotheliocytes of its micrangium.

CONCLUSION

The pathological representation of the ruptured and unruptured aneurysms and the upregulated expresion of MCP-1 in the aneurysm wall suggest that the development of aneurysm may be a course of chronic inflammation in which main inflammatory cells are monocyte-like cells.

Imbibition, but not release from stratification, sets the circadian clock in Arabidopsis seedlings

Circadian rhythms in the abundance of the CAT2 catalase mRNA were not seen in etiolated seedlings but developed upon illumination. These circadian oscillations were preceded by a rapid and transient induction of CAT2 mRNA abundance that varied strikingly according to the timing (circadian phase) of the onset of illumination. This variation oscillated with a circadian periodicity of approximately 28 hr, indicating that the circadian oscillator is running in etiolated seedlings and regulates (gates) the induction of CAT2 by light. Moreover, because we assayed populations of seedlings, we infer that the individual clocks among populations of etiolated seedlings were synchronized before the onset of illumination. What developmental or environmental signals synchronized the clocks among seedlings? Varying the phase of the onset of illumination relative to release from stratification failed to affect the acute induction of CAT2, indicating that the temperature step from 4 to 22 degrees C associated with release from stratification did not reset the circadian clock. However, the acute induction of CAT2 mRNA varied with time after imbibition, demonstrating that imbibition provides a signal capable of resetting the circadian clock and of synchronizing the clocks among populations of seedlings.

Effects of synergistic signaling by phytochrome A and cryptochrome1 on circadian clock-regulated catalase expression

Persistent oscillation in constant conditions is a defining characteristic of circadian rhythms. However, in plants transferred into extended dark conditions, circadian rhythms in mRNA abundance commonly damp in amplitude over two or three cycles to a steady state level of relatively constant, low mRNA abundance. In Arabidopsis, catalase CAT3 mRNA oscillations damp rapidly in extended dark conditions, but unlike catalase CAT2 and the chlorophyll a/b binding protein gene CAB, in which the circadian oscillations damp to low steady state mRNA abundance, CAT3 mRNA oscillations damp to high steady state levels of mRNA abundance. Mutational disruption of either phytochrome- or cryptochrome-mediated light perception prevents damping of the oscillations in CAT3 mRNA abundance and reveals strong circadian oscillations that persist for multiple cycles in extended dark conditions. Damping of CAT3 mRNA oscillations specifically requires phytochrome A but not phytochrome B and also requires the cryptochrome1 blue light receptor. Therefore, we conclude that synergistic signaling mediated through both phytochrome A and cryptochrome1 is required for damping of circadian CAT3 mRNA oscillations in extended dark conditions.

Catalase is encoded by a multigene family in Arabidopsis thaliana (L.) Heynh

The catalase multigene family in Arabidopsis includes three genes encoding individual subunits that associate to form at least six isozymes that are readily resolved by nondenaturing gel electrophoresis. CAT1 and CAT3 map to chromosome 1, and CAT2 maps to chromosome 4. The nucleotide sequences of the three coding regions are 70 to 72% identical. The amino acid sequences of the three catalase subunits are 75 to 84% identical and 87 to 94% similar, considering conservative substitutions. Both the individual isozymes and the individual subunit mRNAs show distinct patterns of spatial (organ-specific) expression. Six isozymes are detected in flowers and leaves and two are seen in roots. Similarly, mRNA abundance of the three genes varies among organs. All three mRNAs are highly expressed in bolts, and CAT2 and CAT3 are highly expressed in leaves.

The circadian clock gates expression of two Arabidopsis catalase genes to distinct and opposite circadian phases

In Arabidopsis thaliana, catalase is encoded by a small gene family. We have characterized cDNA and genomic clones containing the Arabidopsis catalase gene CAT3, present as a single copy in the nuclear genome. Six introns were identified in the CAT3 coding region and two transcription start sites have been been mapped by primer extension. The deduced amino acid sequence of CAT3 is highly similar to other catalases. CAT3 expression is similar in seedlings germinated and grown either in continuous light or in continuous dark, suggesting that CAT3 expression in seedlings is not light responsive. CAT3 expression is controlled by the circadian clock; in 5-week-old plants grown on a light-dark cycle and then transferred to continuous light, robust oscillations in CAT3 mRNA abundance with circadian period persist for at least five circadian cycles. Interestingly, the peak in CAT3 mRNA abundance occurs in the subjective evening, which is out of phase with expression of the Arabidopsis CAT2 catalase gene, which shows clock-regulated expression gated to the subjective early morning.

[Clinical and experimental study of diagnosis of viral myocarditis using gene amplification by polymerase chain reaction]

Polymerase chain reaction (PCR) technique was applied for detection of picornavirus genomes in blood and myocardial tissue of patients with viral myocarditis. Additionally, the blood and myocardial tissue of rabbits infected by picornavirus was also screened by PCR. Twelve rabbits infected by piocrnavirus showed pathological change of myocarditis and all of these animals gave a positive PCR result for picornaviral RNA sequences in the blood and myocardial tissue. All 6 control rabbits gave no PCR positive signals. PCR gene amplification actually provides a new diagnostic approach to patients suspected of viral myocarditis.