Reconstruction of the hemidiaphragm and hemipericardium using combined reversed latissimus dorsi and serratus anterior muscle flaps

We used autologous tissue for the reconstruction of intrathoracic structures after extrapleural pneumonectomy in six patients. The resected areas of the hemidiaphragm and hemipericardium were reconstructed using combined reversed latissimus dorsi and serratus anterior muscle flaps. Based on our results, we conclude that the combined reversed latissimus dorsi and serratus anterior muscle flaps are broad enough to cover any defect within the hemithorax. Thus, we think that this technique is the best choice for multisite reconstruction after extrapleural pneumonectomy.

Restoration of TGF-beta signalling reduces tumorigenicity in human lung cancer cells

Members of the transforming growth factor-β (TGF-β) family regulate a wide range of biological processes including cell proliferation, migration, differentiation, apoptosis, and extracellular matrix deposition. Resistance to TGF-β-mediated tumour suppressor function in human lung cancer may occur through the loss of type II receptor (TβRII) expression. In this study, we investigated the expression pattern of TβRII in human lung cancer tissues by RT–PCR and Western blot analyses. We observed downregulation of TβRII in 30 out of 46 NSCLC samples (65%) by semiquantitative RT–PCR. Western blot analyses with tumour lysates showed reduced expression of TβRII in 77% cases. We also determined the effect of TβRII expression in lung adenocarcinoma cell line (VMRC-LCD) that is not responsive to TGF-β due to lack of TβRII expression. Stable expression of TβRII in these cells restored TGF-β-mediated effects including Smad2/3 and Smad4 complex formation, TGF-β-responsive reporter gene activation, inhibition of cell proliferation and increased apoptosis. Clones expressing TβRII showed reduced colony formation in soft-agarose assay and significantly reduced tumorigenicity in athymic nude mice. Therefore, these results suggest that reestablishment of TGF-β signalling in TβRII null cells by stable expression of TβRII can reverse malignant behaviour of cells and loss of TβRII expression may be involved in lung tumour progression.

Use of a Modified Dumon Stent for Postoperative Bronchopleural Fistula

This report describes a case of a postoperative bronchopleural fistula successfully managed with a modified Dumon stent. Surgical interventions for the bronchopleural fistula with empyema were subsequently avoided. Dumon stent is an acceptable option for the treatment of postoperative bronchopleural fistulas.

Altered regulation of c-jun and its involvement in anchorage-independent growth of human lung cancers

The c-jun oncogene is frequently overexpressed in non-small-cell lung cancers (NSCLC), but its functional involvement in lung cancer development has not been clearly elucidated. In this study, we found that among the immediate-early serum responsible genes, exemplified by c-jun, c-fos and c-myc, induction of c-jun in a human bronchial epithelial cell line, BEAS-2B, was dependent on anchorage, in contrast to clear induction of c-fos and c-myc under both anchorage-dependent and -independent conditions. In fact, forced expression of c-jun in BEAS-2B cells significantly increased cell viability and colony formation in soft agar. Furthermore, we also found that such anchorage-dependent regulation of c-jun was lost in a significant fraction of human lung cancer cell lines. Interestingly, suppressed anchorage-independent but not anchorage-dependent growth was noted by constitutive expression of a dominant-negative c-jun mutant in a lung cancer cell line showing dysregulated and sustained c-jun expression in the absence of anchorage. These findings suggest that dysregulated c-jun expression may be involved in the acquisition of anchorage independence in the process of human lung carcinogenesis.

Experimental study of a new tracheal prosthesis: Pored Dacron tube

OBJECTIVE

This study was designed to evaluate how various sizes and densities of pores in Dacron tubing might enhance its utility as a tracheal prosthesis.

METHODS

A vascular prosthesis made of knitted external velour polyester was prepared for pore formation with a laser. The first set compared different pore sizes (300, 500, and 700 microm) and pore densities (25/cm(2) or 100/cm(2)). Grafts were reinforced with an externally heat-sealed silicone ring. The second set tested grafts with a pore density of 64/cm(2) and a pore size of 500 microm internally reinforced with a stainless-steel spiral stent. In all experiments, a canine mediastinal trachea 10 cartilage rings in length was resected, and the prosthesis was then implanted with an omental flap.

RESULTS

Lower pore size and density (300 microm, 25 pores/cm(2)) led to essentially no tissue ingrowth. Larger pore size (700 microm) and low density (25 pores/cm(2)) led to rapid and excessive ingrowth of granulation. Midrange pore size (500 microm) and high density (100 pores/cm(2)) invited steady tissue ingrowth, but marked luminal stenosis eventually developed. Stent-reinforced prostheses with 500-microm pores at 64 pores/cm(2), as used in the second set, maintained an average patency rate of 60% or more (range, 20%-100%) at least 12 months after implantation.

CONCLUSION

Our data show that porosity is a key factor for tissue growth through our Dacron tracheal prostheses. This artificial trachea model has led to long-term survivors up to 27 months after the operation and seems promising as a basic model for clinical tracheal repair.

[Clinical outcome of epithelial tumors of the thymus]

OBJECTIVE AND METHODS

We retrospectively reviewed treatment and clinical outcome of thymic epithelial tumors of 64 patients over a 20-year period. Clinical staging of the tumor was done by according to Masaoka classification. Histological diagnosis of the tumors was done by according to the second edition of the WHO histologic classification system for thymic epithelial tumors. Survival rate was calculated after Kaplan-Meire method.

RESULTS

Median age of patients was 53.7 years (ranged from 16 to 81). There were 30 men and 34 women. Eighteen patients had auto-immuno diseases. Sixty-two patients underwent surgery. In 57 patients resection was complete (extended thymo-thymectomy), but in the other five incomplete. The operative approach was median sternotomy in 51 patients and video-assisted thoracoscopic surgery in 6. Stage II to IV patients had postoperative mediastinal irradiation. Stage III to IV patients had postoperative cisplatin (CDDP) based chemotherapy. Inoperable patients were treated by chemo-radiotherapy. There were 42 stage I, 7 stage II, 11 stage III, 3 stage IV a, 1 stage IV b. The 5-year/10-year survival rates were 93%/89%, 71%/71%, 68.5%/--in patients with stage I, II and III. There were 5 type A tumors, 8 type AB tumors, 11 type B1 tumors, 11 type B2 tumors, 9 type B3 tumors, 11 type C tumors, the respect 5-year survival rates were 100%, 100%, 87.5%, 60%, 85.7% and 90%. Masaoka stage II to IV patients classified in B2, B3 and C type except one case.

CONCLUSION

Histologic type B2, B3 and C tumors may reflect the invasive nature. Masaoka staging system and the WHO histologic classification may help the assessment and treatment of patients with thymic epithelial tumor.

Non-invasive quantitative monitoring of cerebral blood flow in aneurysmal subarachnoid haemorrhage with 99mTc-ECD

The purpose of this prospective study was to detect symptomatic cerebral vasospasm in aneurysmal subarachnoid haemorrhage (SAH) by a non-invasive mean cerebral blood flow (mCBF) quantification using 99mTc-ethyl cysteinate dimer. Measurement of mCBF without blood sampling and single photon emission tomography (SPECT) were performed at 1 and 7 days after surgery in 35 consecutive SAH patients, of whom 16 were examined at day 30 as well. A decrease in mCBF of more than 10% on day 7 versus day 1 was considered to indicate vasospasm. On visual interpretation of SPECT, a perfusion decrease which appeared newly on day 7 was considered to indicate vasospasm. In total, nine of 35 patients had cerebral vasospasm confirmed by computed tomography (CT) and/or angiography. The mCBF measurement showed a 77.8% (7/9) sensitivity, a 88.5% (23/26) specificity, a 70.0% (7/10) positive predictive value, and a 92.0% (23/25) negative predictive value. SPECT yielded a 33.3% (3/9) sensitivity, a 73.1% (19/26) specificity, a 30.0% (3/10) positive predictive value, and a 76.0% (19/25) negative predictive value. On SPECT, decreased perfusion was observed in most of the patients at clipping sites, which might represent post-operative transient abnormal perfusion and should not be read as vasospasm. In conclusion, this mCBF measurement is more accurate than visual interpretation of SPECT for detecting vasospasm.

Design and synthesis of a dimeric derivative of RK-682 with increased inhibitory activity against VHR, a dual-specificity ERK phosphatase: implications for the molecular mechanism of the inhibition

BACKGROUND

VHR is a dual-specificity phosphatase, which dephosphorylates activated ERK1/2 and weakens the ERK signaling cascade in mammalian cells. A selective inhibitor is expected to be useful for revealing the physiological function of VHR.

RESULTS

First, we investigated the molecular mechanism of VHR inhibition by a known natural product, RK-682. Kinetic analysis indicated that inhibition was competitive toward the substrate, and two molecules of RK-682 were required to inhibit one molecule of VHR. Based on the structure-activity relationships for VHR inhibition by RK-682 derivatives, we constructed a binding model using molecular dynamics calculation. Based on this model, we designed and synthesized a novel dimeric derivative. As expected, the dimeric derivative showed increased inhibition of VHR, supporting our proposed mechanism of VHR inhibition by RK-682.

CONCLUSION

We have developed a novel inhibitor of VHR based on the results of kinetic analysis and docking simulation.

TU-572, a potent and selective CD45 inhibitor, suppresses IgE-mediated anaphylaxis and murine contact hypersensitivity reactions

BACKGROUND

CD45, receptor-type protein tyrosine phosphatases (PTPases) are essential components of signaling through both the T cell receptor and the B cell antigen receptor. However, the functional significance of CD45 in the signaling pathway through the high-affinity immunoglobulin (Ig) E receptor has not yet been established. In this study, we demonstrate that the potent CD45 inhibitor negatively regulates IgE-dependent anaphylaxis and contact hypersensitivity reactions.

METHOD

We have previously found that TU-572, 2-[(4-methylthiopyridin-2-yl)methylsulfinyl]-5-isopropoxybenzimidazole, had a potent and selective inhibitory effect against PTPase activity of CD45. Using a CD45 inhibitor, we examined in vitro and in vivo IgE-mediated responses.

RESULTS

TU-572 potently inhibited histamine release from rat peritoneal mast cells and mouse systemic anaphylaxis reaction using monoclonal anti-dinitrophenyl (DNP) IgE and DNP-BSA. TU-572 also suppressed the immediate-type hypersensitivity response induced by repeated epicutaneous application of trinitrochlorobenzene in BALB/c mice.

CONCLUSION

These findings revealed that the PTPase activity of CD45 played a critical role in signal transduction of IgE-mediated anaphylaxis in vitro and in vivo. PTPase inhibitors such as TU-572 are useful in the treatment of allergic diseases.

Changes in atrial natriuretic peptide and brain natriuretic peptide associated with hypobaric hypoxia-induced pulmonary hypertension in rats

Experimental pulmonary hypertension induced in a hypobaric hypoxic environment (HHE) is characterized by structural remodeling of the heart and pulmonary arteries. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) both have diuretic, natriuretic, and hypotensive effects, and both are involved in cardiovascular homeostasis as cardiac hormones. To study the effects of HHE on the natriuretic peptide synthesis system, 170 male Wistar rats were housed in a chamber at the equivalent of the 5500-m altitude level for 1-12 weeks. After 1 week of HHE, pulmonary arterial pressure was significantly raised, and the ratio of left ventricle plus septum over right ventricle of the heart showed a significant decrease (compared with those of ground-level control rats). In both ventricular tissues, the expression of ANP messenger (m)RNA and BNP mRNA increased after exposure to HHE. The amounts of ANP and BNP had decreased significantly in right atrial tissue at 12 weeks of HHE (compared with those of the controls), whereas in ventricular tissues at the same time point, both levels had increased significantly. In in situ hybridization and immunohistochemical studies, the staining of the mRNAs for ANP and BNP and of ANP and BNP themselves was more intense in both ventricular tissues after exposure to HHE than before (i.e., in the controls). The results suggest that, in response to HHE, the changes in ventricular synthesis are similar for ANP and BNP. These changes may play a role in modulating pulmonary hypertension in HHE. However, under our conditions, pulmonary hypertension increased progressively throughout the HHE period.

Heterogeneous transforming growth factor (TGF)-beta unresponsiveness and loss of TGF-beta receptor type II expression caused by histone deacetylation in lung cancer cell lines

Transforming growth factor (TGF)-beta strongly inhibits epithelial cell proliferation. Alterations of TGF-beta signaling are thought to play a role in tumorigenesis. We show in the present study that most lung cancer cell lines have lost the growth-inhibitory response to TGF-beta signal, and that those with TGF-beta unresponsiveness can be divided into two major groups, TGF-beta type II receptor (TGFbetaRII)(+)/Smad7(+) and TGFbetaRII(-)/Smad7(-), suggesting the heterogeneous mechanisms underlying the TGF-beta responsiveness. The mechanism of the loss of TGFbetaRII expression of the latter group was further studied, identifying aberrant DNA methylation of the promoter region in a limited fraction of cell lines. Interestingly, we found that the alteration of chromatin structure because of histone deacetylation may also be involved, showing a good correlation with loss of TGFbetaRII expression. This notion was supported by the findings of a restriction enzyme accessibility assay, of a chromatin immunoprecipitation assay with anti-acetyl histone antibodies, and of an in vivo induction of TGFbetaRII expression by histone deacetylase inhibitors including trichostatin A (TSA) and sodium butyrate. In vitro induction of TGFbetaRII promoter reporter activity by TSA was also detected and found to require the CCAAT box within the -127/-75 region. A positive regulatory mechanism for TGFbetaRII expression in a TGF-beta-expressing cell line was also investigated, and a TPA-responsive element (TRE)-like motif, TRE2, was detected in addition to the previously reported TRE-like motif Y element in the positive regulatory region. Alterations in two discrete proteins interacting with these two TRE-like motifs were also suspected of being involved in the loss of TGFbetaRII expression. This is the first study to demonstrate that, in addition to the TSA-responsive region and TRE2 motif in the TGFbetaRII promoter, the alteration of histone deacetylation may be involved in the loss of TGFbetaRII expression in lung cancer cell lines.

Surgically treated Swyer-James syndrome

Because patients with Swyer-James syndrome have almost always been treated conservatively, few reports exist of pathological findings of the lung in this syndrome. We report a case of this rare disease treated surgically and discuss pathological findings. A 36-year-old woman repeatedly contracted bronchitis and pneumothorax since adolescence, until April 26, 1997, when she reported chest pain and dyspnea. Chest X-ray on admission showed left pulmonary collapse with a slight deviation of the mediastinum toward the right. Chest computed tomography showed an apical bulla and emphysematous change in the left upper lobe. Pulmonary arteriography at age 17 showed hypoplasia of left pulmonary artery branches in the left upper lobe. Based on a diagnosis of Swyer-James syndrome, we conducted left upper lobectomy on May 2, 1997. Pathological examination of the resected left upper lobe showed marked emphysematous change, including an emphysematous bulla with destruction of alveolar structure and peribronchiolar fibrosis. No vascular abnormality was recognized in histology. Emphysematous change secondary to repeated bronchiolitis is believed to have led to her repeated pneumothorax.

A facile and effective screening method for p21WAF1 promoter activators from microbial metabolites

We have developed a novel p21WAF1 promoter activator screening system based on rapid and facile luciferase activity assay of a model cell system (H1299/tsp53-luc cells), a stable luciferase expression cell line established by transfecting H1299/tsp53 cells with a reporter gene construct pWWP-Luc-BSD. This plasmid was constructed by subcloning the 2.4 kb p21WAF1 promoter and a 2.6 kb of luciferase cDNA fragment activated by the p21WAF1 promoter into a pMAM2-BSD expression vector containing the blasticidin S deaminase gene (BSD). A BSD-resistant clone H1299/tsp53-luc#4, showing the highest response to p53 activation (by temperature shift from 37 degrees C to 32 degrees C) by luciferase production, was used for screening microbial culture broths. Among approximately 1200 screened samples, trichostatin A related compounds and a new compound, lucilactaene, were isolated. This provides an effective and facile screening system for p21WAF1 promoter activators which should be of considerable value in the rapid identification of new anticancer agents.

Persistent increase in chromosome instability in lung cancer: possible indirect involvement of p53 inactivation

Karyotype and fluorescence in situ hybridization analyses have demonstrated the frequent presence of an altered static state of the number of chromosomes (ie, aneuploidy) in lung cancer, but it has not been directly established whether aneuploidy is in fact associated with a persistent increase in the rate of chromosomal losses and gains (ie, chromosome instability, or CIN). The study presented here used a panel of 10 lung cancer cell lines to provide for the first time direct evidence that CIN is a common feature in lung cancer cell lines in association with the presence of significant aneuploidy. In addition, we found that the CIN phenotype correlates well with the presence of p53 mutations. However, human papilloma virus 16-E6-directed inactivation of p53 in a representative non-CIN lung cancer cell line did not result in the induction of CIN, at least up to the 25th generation, suggesting that inactivation of p53 itself is unlikely to directly induce CIN in lung cancer cells. Interestingly, however, significant CIN could be induced in conjunction with the generation of aneuploid populations when the mitotic spindle formation was transiently abrogated in p53-inactivated cells. These results suggest that inactivation of p53 may allow lung cancer cells to go through an inappropriate second division cycle under certain forms of mitotic stresses, which would result in the induction of the CIN phenotype in conjunction with the generation of aneuploidy.

The yield of abnormal unfertilized eggs observed after repeated gonadotrophin-induced ovulation

This study investigated whether or not the yield of abnormal eggs produced after repeatedly induced ovulation could be reduced by increasing the interval between gonadotrophin (GTH) administrations. Ovulation was induced, in a mouse model, by subcutaneous injection of pregnant mare serum GTH and human chorionic GTH given once (n = 10), twice (n = 10), three times (n = 10) or four times (n = 10) at intervals of 5 days. In 30 further mice, a fifth induction was performed either 5 (n = 10), 10 (n = 10) or 20 days (n = 10) following the fourth injection. Oviducts were examined microscopically, and the eggs were counted and examined for morphological abnormalities. In the mice who had received four GTH treatments, 33.3% (12 of 36) of the eggs were abnormal. After the fifth induced ovulation performed after an interval of 5, 10 or 20 days, the yield of abnormal eggs was 50.0% (five of 10), 23.1% (nine of 39) and 15.2% (seven of 46), respectively. These results indicate that prolongation of the interval between GTH administrations reduced the yield of abnormal eggs produced following repeatedly induced ovulation.

Relationship between changes in volume of the oviductal fluid in the ampulla and the descent of ovulated eggs from the ampulla to the isthmus in mice

Follicular growth and ovulation were induced in mice by administration of pregnant mare serum gonadotrophin (PMSG) followed 2 days later by human chorionic gonadotrophin; the day of PMSG injection was designated as day 0. The volume of the ampulla was measured and the location of the ovulated eggs determined at 06:00, 10:00, 14:00, 18:00 and 22:00 on day 3, and at 02:00 and 06:00 on day 4. The volume of the ampulla and hence oviductal fluid, peaked at 14:00 on day 3 and then declined. In all oviduct samples taken up to 14:00 on day 3, eggs were found exclusively in the ampulla. Thereafter, an increasing number of eggs were observed in the isthmus. Thus, the migration of eggs from the ampulla to the isthmus was concurrent with the decrease in oviductal fluid volume. The peak in the volume of oviductal fluid seen at day 3 is likely to coincide with the opening of the ampullary-isthmic junction of the oviduct.