Cartilage tissues regulate systemic aging via ectonucleotide pyrophosphatase/phosphodiesterase 1 in mice

Aging presents fundamental health concerns worldwide; however, mechanisms underlying how aging is regulated are not fully understood. Here, we show that cartilage regulates aging by controlling phosphate metabolism via ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1). We newly established an Enpp1 reporter mouse, in which an EGFP-luciferase sequence was knocked-in at the Enpp1 gene start codon (Enpp1/EGFP-luciferase), enabling detection of Enpp1 expression in cartilage tissues of resultant mice. We then established a cartilage-specific Enpp1 conditional knockout mouse (Enpp1 cKO) by generating Enpp1 flox mice and crossing them with cartilage-specific type 2 collagen Cre mice. Relative to WT controls, Enpp1 cKO mice exhibited phenotypes resembling human aging, such as short life span, ectopic calcifications, and osteoporosis, as well as significantly lower serum pyrophosphate levels. We also observed significant weight loss and worsening of osteoporosis in Enpp1 cKO mice under phosphate overload conditions, similar to global Enpp1-deficient mice. Aging phenotypes seen in Enpp1 cKO mice under phosphate overload conditions were rescued by a low vitamin D diet, even under high phosphate conditions. These findings suggest overall that cartilage tissue plays an important role in regulating systemic aging via Enpp1.

The IL-17-IL-17RA axis is required to promote osteosarcoma progression in mice

Osteosarcoma is rare but is the most common bone tumor. Diagnostic tools such as magnetic resonance imaging development of chemotherapeutic agents have increased the survival rate in osteosarcoma patients, although 5-year survival has plateaued at 70%. Thus, development of new treatment approaches is needed. Here, we report that IL-17, a proinflammatory cytokine, increases osteosarcoma mortality in a mouse model with AX osteosarcoma cells. AX cell transplantation into wild-type mice resulted in 100% mortality due to ectopic ossification and multi-organ metastasis. However, AX cell transplantation into IL-17-deficient mice significantly prolonged survival relative to controls. CD4-positive cells adjacent to osteosarcoma cells express IL-17, while osteosarcoma cells express the IL-17 receptor IL-17RA. Although AX cells can undergo osteoblast differentiation, as can patient osteosarcoma cells, IL-17 significantly inhibited that differentiation, indicating that IL-17 maintains AX cells in the undifferentiated state seen in malignant tumors. By contrast, IL-17RA-deficient mice transplanted with AX cells showed survival comparable to wild-type mice transplanted with AX cells. Biopsy specimens collected from osteosarcoma patients showed higher expression of IL-17RA compared to IL-17. These findings suggest that IL-17 is essential to maintain osteosarcoma cells in an undifferentiated state and could be a therapeutic target for suppressing tumorigenesis.

Transthyretin amyloid deposition in ligamentum flavum (LF) is significantly correlated with LF and epidural fat hypertrophy in patients with lumbar spinal stenosis

Lumbar spinal stenosis (LSS) is a degenerative disease characterized by intermittent claudication and numbness in the lower extremities. These symptoms are caused by the compression of nerve tissue in the lumbar spinal canal. Ligamentum flavum (LF) hypertrophy and spinal epidural lipomatosis in the spinal canal are known to contribute to stenosis of the spinal canal: however, detailed mechanisms underlying LSS are still not fully understood. Here, we show that surgically harvested LFs from LSS patients exhibited significantly increased thickness when transthyretin (TTR), the protein responsible for amyloidosis, was deposited in LFs, compared to those without TTR deposition. Multiple regression analysis, which considered age and BMI, revealed a significant association between LF hypertrophy and TTR deposition in LFs. Moreover, TTR deposition in LF was also significantly correlated with epidural fat (EF) thickness based on multiple regression analyses. Mesenchymal cell differentiation into adipocytes was significantly stimulated by TTR in vitro. These results suggest that TTR deposition in LFs is significantly associated with increased LF hypertrophy and EF thickness, and that TTR promotes adipogenesis of mesenchymal cells. Therapeutic agents to prevent TTR deposition in tissues are currently available or under development, and targeting TTR could be a potential therapeutic approach to inhibit LSS development and progression.

Remnant tissue enhances early postoperative biomechanical strength and infiltration of Scleraxis-positive cells within the grafted tendon in a rat anterior cruciate ligament reconstruction model

When ruptured, ligaments and tendons have limited self-repair capacity and rarely heal spontaneously. In the knee, the Anterior Cruciate Ligament (ACL) often ruptures during sports activities, causing functional impairment and requiring surgery using tendon grafts. Patients with insufficient time to recover before resuming sports risk re-injury. To develop more effective treatment, it is necessary to define mechanisms underlying ligament repair. For this, animal models can be useful, but mice are too small to create an ACL reconstruction model. Thus, we developed a transgenic rat model using control elements of Scleraxis (Scx), a transcription factor essential for ligament and tendon development, to drive GFP expression in order to localize Scx-expressing cells. As anticipated, Tg rats exhibited Scx-GFP in ACL during developmental but not adult stages. Interestingly, when we transplanted the flexor digitorum longus (FDP) tendon derived from adult Scx-GFP+ rats into WT adults, Scx-GFP was not expressed in transplanted tendons. However, tendons transplanted from adult WT rats into Scx-GFP rats showed upregulated Scx expression in tendon, suggesting that Scx-GFP+ cells are mobilized from tissues outside the tendon. Importantly, at 4 weeks post-surgery, Scx-GFP-expressing cells were more frequent within the grafted tendon when an ACL remnant was preserved (P group) relative to when it was not (R group) (P vs R groups (both n = 5), p<0.05), and by 6 weeks, biomechanical strength of the transplanted tendon was significantly increased if the remnant was preserved (P vsR groups (both n = 14), p<0.05). Scx-GFP+ cells increased in remnant tissue after surgery, suggesting remnant tissue is a source of Scx+ cells in grafted tendons. We conclude that the novel Scx-GFP Tg rat is useful to monitor emergence of Scx-positive cells, which likely contribute to increased graft strength after ACL reconstruction.

A machine learning-based scoring system and ten factors associated with hip fracture occurrence in the elderly

Hip fractures are fragility fractures frequently seen in persons over 80-years-old. Although various factors, including decreased bone mineral density and a history of falls, are reported as hip fracture risks, few large-scale studies have confirmed their relevance to individuals older than 80, and tools to assess contributions of various risks to fracture development and the degree of risk are lacking. We recruited 1395 fresh hip fracture patients and 1075 controls without hip fractures and comprehensively evaluated various reported risk factors and their association with hip fracture development. We initially constructed a predictive model using Extreme Gradient Boosting (XGBoost), a machine learning algorithm, incorporating all 40 variables and evaluated the model's performance using the area under the receiver operating characteristic curve (AUC), yielding a value of 0.87. We also employed SHapley Additive exPlanation (SHAP) values to evaluate each feature importance and ranked the top 20. We then used a stepwise selection method to determine key factors sequentially until the AUC reached a plateau nearly equal to that of all variables and identified the top 10 sufficient to evaluate hip fracture risk. For each, we determined the cutoff value for hip fracture occurrence and calculated scores of each variable based on the respective feature importance. Individual scores were: serum 25(OH)D levels (<10 ng/ml, score 7), femoral neck T-score (<-3, score 5), Barthel index score (<100, score 3), maximal handgrip strength (<18 kg, score 3), GLFS-25 score (≥24, score 2), number of falls in previous 12 months (≥3, score 2), serum IGF-1 levels (<50 ng/ml, score 2), cups of tea/day (≥5, score -2), use of anti-osteoporosis drugs (yes, score -2), and BMI (<18.5 kg/m2, score 1). Using these scores, we performed receiver operating characteristic (ROC) analysis and the resultant optimal cutoff value was 7, with a specificity of 0.78, sensitivity of 0.75, and AUC of 0.85. These ten factors and the scoring system may represent tools useful to predict hip fracture.

Potential function of Scx+/Sox9+ cells as progenitor cells in rotator cuff tear repair in rats

Tendons and their attachment sites to bone, fibrocartilaginous tissues, have poor self-repair capacity when they rupture, and have risks of retear even after surgical repair. Thus, defining mechanisms underlying their repair is required in order to stimulate tendon repairing capacity. Here we used a rat surgical rotator cuff tear repair model and identified cells expressing the transcription factors Scleraxis (Scx) and SRY-box 9 (Sox9) as playing a crucial role in rotator cuff tendon-to-bone repair. Given the challenges of establishing stably reproducible models of surgical rotator cuff tear repair in mice, we newly established Scx-GFP transgenic rats in which Scx expression can be monitored by GFP. We observed tissue-specific GFP expression along tendons in developing ScxGFP transgenic rats and were able to successfully monitor tissue-specific Scx expression based on GFP signals. Among 3-, 6-, and 12-week-old ScxGFP rats, Scx+/Sox9+ cells were most abundant in 3-week-old rats near the site of humerus bone attachment to the rotator cuff tendon, while we observed significantly fewer cells in the same area in 6- or 12-week-old rats. We then applied a rotator cuff repair model using ScxGFP rats and observed the largest number of Scx+/Sox9+ cells at postoperative repair sites of 3-week-old relative to 6- or 12-week-old rats. Tendons attach to bone via fibrocartilaginous tissue, and cartilage-like tissue was seen at repair sites of 3-week-old but not 6- or 12-week-old rats during postoperative evaluation. Our findings suggest that Scx+/Sox9+ cells may function in rotator cuff repair, and that ScxGFP rats could serve as useful tools to develop therapies to promote rotator cuff repair by enabling analysis of these activities.

Association of Severe Histological Degeneration of the Torn Supraspinatus Tendon and Retear After Arthroscopic Repair of Full-Thickness Rotator Cuff Tears Using the Suture Bridge Technique

BACKGROUND

Previous studies have demonstrated several prognostic factors for retear after arthroscopic rotator cuff repair (ARCR). However, studies that histologically evaluate the quality of the torn rotator cuff (RC) tendon and its association with postoperative outcomes are limited.

PURPOSE

To investigate factors associated with retear after ARCR using the suture bridge (SB) technique, including the degree of histological degeneration of the RC tendon edge.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

The authors retrospectively evaluated 187 patients who underwent ARCR for full-thickness tears using the SB technique; intraoperative biopsy samples were taken to assess the degree of histological degeneration using the Bonar score. The cohort was divided into healed (n = 165) and retear (n = 22) groups according to magnetic resonance imaging results obtained ≥6 months postoperatively. The evaluation included preoperative patient data (age, sex, symptom duration, trauma history, history of heavy manual work, smoking habit, hypertension, diabetes mellitus, and hyperlipidemia) and radiological data (Hamada classification, Patte classification, Goutallier classification, and global fatty degeneration index [GFDI]). Additionally, intraoperative data (anteroposterior tear size, Lafosse classification for concomitant subscapularis tendon tear, and long head of biceps injury) and preoperative and postoperative clinical findings (active range of motion, University of California, Los Angeles [UCLA], score) were evaluated.

RESULTS

The retear rate was 11.8%. The retear group had a higher percentage of men (P = .031), higher Bonar score (P < .001), higher mean GFDI value (P = .002), higher rate of tear retraction degree (P = .010), and larger anteroposterior tear size (P = .020) than the healed group. The retear group had lower postoperative internal rotation (P = .031) and lower UCLA score (P < .001). Multivariate logistic regression analysis with a stepwise variable selection revealed anteroposterior tear size (odds ratio [OR], 2.4; 95% CI, 1.3-4.5; P = .004) and Bonar score (OR, 1.7; 95% CI, 1.3-2.4; P < .001) as independent predictors for a retear.

CONCLUSION

The results indicate that end-stage severe tendon degeneration might affect retear. Therefore, further investigation on the progression mechanisms of tendon degeneration and development of methods to assess degenerative tissue might improve clinical outcomes after ARCR.

SAT0057 PREDICTING INADEQUATE RESPONSE TO JAK INHIBITORS BY CLUSTER ANALYSIS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Oral Janus kinase inhibitors (JAKi) have dramatically altered outcomes in patients with rheumatoid arthritis (RA). However, there remains some proportion of patients who respond to inadequately JAKi treatment (JAKi-IR) [1,2]. The characteristics in RA patients associated with JAKi-IR have not been fully demonstrated.

Objectives:

To clarify the characteristics of JAKi-IR in patients with RA by cluster analysis.

Methods:

This retrospective study comprised 120 RA patients who were treated with JAKi (Tofacitinib or Baricitinib) between July 2013 and September 2019 in five facilities. The disease status at the baseline, at 12 weeks after JAKi treatment and at the time point of withdrawing JAKi was assessed using the Disease Activity Score (DAS28) and the American College of Rheumatology (ACR) response criteria. JAKi-IR was defined as follows, primary non-response at 12 weeks after JAKi treatment: withdrawal of JAKi with ACR20 non-response or non-improvement in DAS28-CRP (ΔDAS28-CRP<1.2 from baseline), secondary non-response: withdrawal of JAKi without clinical remission after 12 weeks. Hierarchical cluster analysis was performed with the following variables: gender, age, disease duration, bone erosion, ACR functional classification (Class ≥3), comcomitant rheumatoid arthritis related interstitial lung disease (RA-ILD) or other autoimmune disease (AID), anti-citrullinated protein antibody (ACPA) positivity, rheumatoid factor (RF) at baseline, use/dose of methotrexate (MTX) and prednisolone (PSL), serum ESR/CRP, tender/swollen joint counts (TJC/SJC), visual analog scale by patients (VAS-Pt), and prior of biologic DMARDs.

Results:

The 120 enrolled patients were classified into 4 groups by cluster analysis(Figure1), The characteristics of each group are as follows, Group A(n=21): female + bone erosion + RF/ACPA positive + AID + MTX non-user, Group B(n=36): male + older age + RA-ILD + RF/ACPA positive + MTX non-user, Group C(n=35): RF/ACPA positive + absence of RA-ILD + MTX user, Group D (n=28): seronegative + MTX user + absence of RA-ILD + history of biologic DMARDs failure. The rate of JAKi-IR was A:9%, B:8%, C:20%, D:32%, and the significant difference between Group B and D was identified (p=0.02). In multiple comparison of 4 groups, no significant difference was identified (p=0.06) (Figure2).

Conclusion:

JAKi-IR would be more likely to be seronegative, MTX use, absence of RA-ILD and history of biologic DMARDs failure. Cluster analysis is an exploratory tool that aids in the analysis of huge amount of data.

References:

[1] Takeuchi T, Yamanaka H, Yamaoka K, Arai S, Toyoizumi S, DeMasi R, et al. Efficacy and safety of tofacitinib in Japanese patients with rheumatoid arthritis by background methotrexate dose: A post hoc analysis of clinical trial data. Mod Rheumatol. 2019;29(5):756-66.

[2] Tanaka Y, Atsumi T, Amano K, Harigai M, Ishii T, Kawaguchi O, et al. Efficacy and safety of baricitinib in Japanese patients with rheumatoid arthritis: Subgroup analyses of four multinational phase 3 randomized trials. Mod Rheumatol. 2018;28(4):583-91.

Disclosure of Interests:

Masanari Sugawara: None declared, Yuichiro Fujieda: None declared, Atsushi Noguchi: None declared, Shun Tanimura: None declared, Yuka Shimizu: None declared, Ikuma Nakagawa: None declared, Michihito Kono: None declared, Masaru Kato: None declared, Kenji Oku: None declared, Tatsuya Atsumi Grant/research support from: Eli Lily Japan K.K., Alexion Pharmaceuticals, Inc., Bristol-Myers Squibb Co., AbbVie Inc., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Astellas Pharma Inc., Consultant of: Gilead Sciences, Inc., Eli Lilly Japan K.K., UCB Japan Co. Ltd., AbbVie Inc., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Speakers bureau: Eli Lilly Japan K.K., UCB Japan Co. Ltd., Bristol-Myers Squibb Co., AbbVie Inc., Eisai Co. Ltd., Otsuka Pharmaceutical Co., Ltd., Daiichi Sankyo Co., Ltd., Pfizer Inc., Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Takeda Pharmaceutical Co., Ltd., Astellas Pharma Inc.

Instability of Superplastic Aluminium Alloys

The influence of the strain hardening coefficient,γ,and the strain rate sensitivity exponent, m, on the onset and growth of necking has been pointed out in many models about plastic instability controlled by the mechanical properties of materials. In this paper, the instability parameter I (=(l-γ-m)/m) proposed by Hart is used to relate the values of m (=∂lnσ/∂lnέ) and γ (=∂σ/(σ·∂ε)) for some superplastic aluminium alloys. These values of m and γ were calculated from the load-elongation curve at various strain-rates in constant strain-rate tests with periodic m determinations by strain-rate departures of small magnitude. It will be shown that the strain hardening due to grain growth contributes to an increase in the stability of plastic deformation during superplastic flow. However the decrease of m due to dynamic grain growth with strain causes superplastic deformation to be unstable near the onset of fracture. The transition of I values from negative to positive coincides with a decrease in m value and flow stress.

It is concluded that the development of necks can be characterized by an instability parameter I which include the effect of strain hardening caused by strain induced grain growth.

Superplasticity in P/M Aluminium Alloys

Recent advances in the technologies of powder metallurgy lead to the development of some superplastic aluminium alloys containing a deliberate addition of a large amount of Zr and /or Cr and Mn that exhibit the high strain rates superplasticity. For a few alloy systems, the large elongation more than 500% has been observed over the strain rates of 1×10−1s−1, which rates are two or three orders of magnitude faster than those at which superplasticity is found in conventional superplastic aluminium alloys produced by ingot metallurgy. The high strain-rates superplasticity obtained in both type of fully static recrystallized and dynamic recrystallized P/M aluminium alloys. The decreasing of initial size of grains and/or sub-grains leads to the increasing the strain-rates for superplastic flow in both types of alloys. The refinement of grains or sub-grains size is one of necessary and important to obtain the high strain-rates superplasticity.

Epidermolysis bullosa acquisita associated with psoriasis vulgaris

We report a case of epidermolysis bullosa acquisita (EBA) associated with psoriasis vulgaris. A 71-year-old woman with psoriasis vulgaris developed subepidermal blisters on the extremities. Direct immunofluorescence demonstrated linear deposit of IgG at the basement membrane zone, which bound to the dermal side of normal human skin split with 1 mol/L NaCl. Immunoblot analysis using recombinant full-length type VII collagen detected a 290-kDa band, confirming the diagnosis of EBA. A literature search for previous reports found a few cases of EBA associated with psoriasis, and all cases, including our own, presented with widespread inflammatory vesicles and bullae, and responded to conventional therapy with corticosteroids and immunosuppressive agents. This study suggests that western blotting using recombinant full-length type VII collagen could be useful for diagnosis of EBA, and that EBA associated with psoriasis may have a tendency to be the inflammatory type.

Laparoscopic gastrectomy with regional lymph node dissection for upper gastric cancer

BACKGROUND

The technique and results of laparoscopic gastrectomy in 110 patients with gastric cancer located in the upper third of the stomach are presented.

METHODS

Proximal gastrectomy was performed for lesions in the upper third of the stomach, and total gastrectomy for those that spread over both the upper and middle third. D1 and D2 lymph node dissection was undertaken in patients with T1 or T2 lesions. Anastomosis of the oesophagus was performed intracorporeally using a conventional circular stapling device or a laparoscopic linear stapler.

RESULTS

Median operating time was 247 min for proximal gastrectomy and 285 min for total gastrectomy; median blood loss was 207 and 334 ml respectively. A median of 23 lymph nodes was harvested from patients in the proximal gastrectomy group and 34 from those having a total gastrectomy. There was minimal morbidity and fast recovery after surgery. Postoperative recurrence occurred in only one patient, giving a recurrence rate of 0.9 per cent.

CONCLUSION

Laparoscopic gastrectomy for upper gastric cancer appears to be a safe and curative procedure.

Triangulating stapling technique for reconstruction after colectomy

BACKGROUND/AIMS

To retrospectively compare the triangulating stapling technique for colocolonic anastomosis with hand-sewn anastomosis and functional end-to-end anastomosis.

METHODOLOGY

Data from 646 patients who underwent colectomy for cancer from 1993 to 2004 were extracted by chart review. Patients were divided into three groups based on the type of anastomosis: handsewn (n=233), functional end-to-end (n=71), and the triangulating stapling method (n=346). Demographic data and clinical characteristics of the three groups were similar.

RESULTS

Anastomotic leakage was significantly more common in the hand-sewn group than the triangular stapling group (hand-sewn; 3.0%, functional end-to-end; 2.8%, triangulating, 0.6%) (P < 0.05). No patient developed bleeding or stenosis at the anastomosis, and the incidence of wound infection was equivalent among the three groups. One death due to anastomotic failure occurred in each of the functional end-to-end and triangulating stapling groups. The cost of triangulating stapling was approximately Yen 36,000 lower than the cost of the functional end-to-end anastomosis.

CONCLUSIONS

The triangulating stapling technique is an attractive alternative to other methods for creating a colocolonic anastomosis.

Two cases of folliculosebaceous cystic hamartoma

Folliculosebaceous cystic hamartoma (FSCH) is a rare cutaneous hamartoma composed of dilated folliculosebaceous units associated with mesenchymal elements. Two cases of FSCH with typical histopathological features are reported. Patient 1 was a 60-year-old man presented with a normal skin-coloured asymptomatic nodule on his scalp. Patient 2 was a 70-year-old man with an asymptomatic nodule on his right auricle that had persisted for the previous 15 years. In all, 34 cases of FSCH have been reported in the English literature. Clinically, the lesions are asymptomatic, usually rubbery to firm in consistency, and usually occur on or above the neck (> 90%). Most lesions do not exceed 25 mm in diameter (> 90%). Histopathologically, FSCH shares several similar features to sebaceous trichofolliculoma, but it is usually possible to differentiate these two tumours.

[Large malignant mesenchymoma of the left posterior mediastinum; report of a case]

Malignant mesenchymoma is a soft tissue tumor arising preferentially in the extremities and retroperitoneum. We report a case of primary malignant mesenchymoma of the left posterior mediastinum. A 24-year-old woman was admitted to our hospital for complaining of cough. Chest X-ray showed a giant mass occupying the 2/3 of the left hemithorax. Chest computed tomography (CT) revealed a lobulated large mass with fat density area and calcified spot in the mediastinum and left pleural space. Chest magnetic resonance imaging (MRI) demonstrated a large solid mass consisting mainly of areas with the same intensity as fatty tissue and partly of areas with heterogenous moderate intensity. The tumor was resected completely under left posterolateral thoracotomy. The pathologic diagnosis was malignant mesenchymoma; well differentiated liposarcoma with osteocartilagenous differentiation. The patient has been well for 3 years and 3 months after surgery.

[Successful removal of T4 lung cancer with left atrial invasion after induction chemotherapy]

A 53-year-old man presented with cough, sputa and chest pain. The chest X-ray revealed a large mass shadow in the right lower lobe. Massive tumor extending into the left atrium was diagnosed by computed tomography (CT). The brushing cytology by broncoscopy was squamous cell carcinoma and its stage was IIIB. Chemothrapy using cisplatin, paclitaxel and gemcitabine hydrochloride was performed 8 courses during 6 months. The effect of the chemotherapy was complete response, enabling the surgical treatment. The right pneumonectomy with partial resection of the left atrium was performed by using vascular clamp. The defect of the left atrium could be sutured directly. Wide-spread necrotic change with very small amount of cancer cells in the atrial wall was confirmed by pathology. The patient has been well for 3 years and 6 months after surgery.

Laparoscopic distal gastrectomy with regional lymph node dissection for gastric cancer

BACKGROUND

Recent advances in surgical techniques have led to widespread acceptance of laparoscopic gastrectomy for gastric cancer. We performed distal gastrectomy with regional lymph node dissection in 235 patients with gastric cancer located in the middle and lower third of the stomach.

METHODS

In 171 cases, reconstruction was done using the Billroth I method intracorporeally and the aid of laparoscopic linear stapling devices. The Billroth II and Roux-en-Y methods were used in the remaining 56 and eight patients, respectively,

RESULTS

Patients who underwent laparoscopic distal gastrectomy had a more rapid postoperative recovery than those treated via the open approach. Postoperative complications with this technique were within a permissible range. In terms of the survival curve, there was no statistical difference between the laparoscopic group diagnosed as clinical T2N0 (c T2N0) Preoperatively and the open group.

CONCLUSION

The laparoscopic technique is not only less invasive, but is also similarly safe and curative compared to open gastrectomy.

Clear cell sarcoma associated with multiple pulmonary metastases with structural and numerical karyotypic changes

Cytogenetic analysis was performed on a specimen from a pulmonary metastasis of clear cell sarcoma originated on the right ankle of a 53-year-old Japanese woman. It revealed near-triploid with several numerical changes including abnormalities in the copy number of chromosomes 7, 8, and 22, and structural abnormalities of chromosome 22 and others. This is a minor case which showed the multiple abnormalities of chromosomes in the absence of a t (12;22) translocation.

A novel laparoscopic technique for stapled colon and rectal anastomosis

BACKGROUND

We present new techniques of stapling anastomosis at laparoscopic colorectal surgery with retrospective review of data.

METHODS

A triangulating stapling technique (T method) was performed in 101 laparoscopic colectomies. Adouble stapling technique (DST) with rectal division by a conventional linear stapler (Abd method) was used in 5 cases of upper/middle rectal cancers and subsequent eversion of the distal rectum from the anus (Ev method) was used for 4 low rectal cancers. Four hundred ninety-six colectomies and 280 rectal surgeries were reviewed.

RESULTS

Leakage was lower in the T group (0.5%, n=196) than in the hand-sewn group (3.0%, n=233). Leakage of the DST using a laparoscopic linear stapler (12.1%, n=91) was significantly higher than with conventional DST (2.1%, n=189). There was no leakage with either Abd method or Ev method. The T-method is acceptable after laparoscopic colectomy.

CONCLUSION

New methods of rectal division using conventional devices are expected to yield reliable anastomosis at laparoscopic rectal surgery.

Laparoscopic distal gastrectomy with regional lymph node dissection for gastric cancer

Recently, a minimally invasive operation for gastric malignancies has been advocated, and the laparoscopic operation is noted as a technique that increases the quality of life. We performed distal gastrectomy with regional lymph node dissection on 160 cases of gastric cancer located in the middle or lower third of the stomach. In 123 cases, Billroth I reconstruction was performed intracorporeally using the quadrilateral (square) stapling technique with a laparoscopic linear stapling device to prevent postoperative anastomotic bleeding and stenosis. In the remaining 37 cases, the Billroth II method was performed with a linear stapling device [1]. This technique is not only less invasive but also as safe as open gastrectomy, which was performed on 100 gastric cancer cases of similar staging.

[A study of thymoma associated with cancer of the other organs]

Out of 97 cases of thymoma for the last 20 years, we have experienced 7 cases (9%) of thymoma associated with cancer of the other organs. The average age of the 7 cases was 60 years old and there were 3 females and 4 males. The organ with cancer was stomach in 3 cases, thyroid in 2, and lung, breast, colon and leukemia in one respectively. Histological classification of 8 thymomas in 7 cases was 3 epithelial type, 2 lymphocytic type and 3 mixed type. Myasthenia gravis with thymoma was only one out of them. we have to follow up carefully the patient with thymoma about occurrence of cancer of the other organs without thymus for a long time.

[Basaloid carcinoma originated from the wall of thymic cyst presenting as pericardial and thoracic effusion; report of a case]

We report a case of basaloid carcinoma originated from the wall of a large thymic cyst, which is a very rare subtype of thymic carcinoma. A 60-year-old man admitted at our hospital due to dyspnea with pericardial and left thoracic effusion on chest X-ray. A computed tomography and a magnetic resonance imaging demonstrated a large anterior mediastinal cyst and a small mass lesion on the part of the wall. We performed as possible as resection of the thymic cyst and the tumor with median sternotomy. The pathological diagnosis was a thymic basaloid carcinoma originated from the wall of a thymic cyst, which classified into a low-grade histology in thymic carcinoma. He has been well with no evidence of recurrence for three years since operation followed by a post-operative radiation therapy (total 57 Gy) to the residual tumor and mediastinum.

[Surgical treatment for bilateral multiple lung cancers]

We reviewed 21 patients with bilateral multiple bronchogenic carcinomas. Eleven of them had synchronous carcinomas and 10 had metachronous carcinomas. We treated 6 patients with lobectomy and wedge resection under median sternotomy synchronously, and 2 patients with lobectomy on both lungs under standard thoracotomy, 2 patients with lobectomy and wedge resection, 1 patient with segmentectomy on both lung, 1 patient with lobectomy and segmentectomy, 1 patient with pneumonectomy and wedge resection, and 8 patients with lobectomy and thoracoscopic wedge resection on each lung metachronously. Two patients who had lobectomy on both lungs were dead, one of whom of pulmonary edema 2 weeks after second operation and the other of respiratory failure 3 years after second operation. We concluded that lobectomy on both lungs are not recommended because of high mortality rate (10%) and the limited resection under thoracoscopic surgery should be considered to treat the other contra lateral primary lung cancers.

ERK pathway positively regulates the expression of Sprouty genes

Sprouty was originally identified as an inhibitor of Drosophila development-associated receptor tyrosine kinase (RTK) signaling. Although RTK signaling has been shown to induce Sprouty gene expression, the precise induction pathway downstream of RTK remains unclear. As RTK signaling pathway includes activation of extracellular signal-regulated kinases (ERKs), we have examined a correlation between activation of ERKs and induction of Sprouty gene expression. All reagents which induce the activation of ERKs induce Sprouty gene expression; these agents include not only growth factors which bind to RTK but also phorbol 12-myristate-13-acetate and active Raf-1 kinase. Furthermore, the Sprouty gene expression induced by all those agents is totally suppressed when the cells are pretreated with specific inhibitors of ERK kinase (MEK). Human tumor cells which exhibit constitutive activation of ERKs show elevated expression of Sprouty genes, which is abolished by treatment of these cells with MEK inhibitors. All these findings clearly indicate that Sprouty gene expression is positively regulated by the ERK pathway downstream of RTK.

Laparoscopy-assisted resection for jejunal carcinoma

Laparoscopic surgery has been applied in small bowel resections for various diseases, such as obstruction including intussusception, diverticula, and tumors. We report a case of successful resection of a jejunal carcinoma that was diagnosed before surgery by using a laparoscopy-assisted technique.

Hand-assisted laparoscopic distal gastrectomy with regional lymph node dissection for gastric cancer

Recently, a minimally invasive operation for gastric malignancies has been advocated, and the laparoscopic operation is noted as a technique that raises the quality of life. We performed distal gastrectomy with regional lymph node dissection by hand-assisted laparoscopic surgery for 60 cases of gastric cancer located in the middle or lower third of the stomach. Billroth I reconstruction was applied intracorporeally to the first 30 cases by using the double stapling method with a conventional circular stapling device, and in the final 30 cases, the quadrilateral (square) stapling technique with a laparoscopic linear stapling device was used to prevent postoperative anastomotic bleeding. This technique not only is less invasive, but also is similarly curative compared with open gastrectomy that was performed for 60 gastric cancer cases of similar staging before the beginning of this procedure.

[A case of benign schwannoma arising in the brachial plexus with intrathoracic extension]

A case of benign schwannoma originating from the lowest trunk of the left brachial plexus with intrathoracic extension was reported. Intrathoracic growth of a schwannoma of the brachial plexus has been reported in only five cases in the literature. The patient was a 35-year-old man and had been pointed out an abnormal shadow at the left lung apex on the roentgenogram since 20-year-old. The tumor shadow was increased to seven cm from four in size on recent chest X-ray. We performed a video-assisted thoracoscopic surgery with the oblique skin incision at the left neck and removed the tumor completely and safely.

Hypoglycemia induced by secretion of high molecular weight insulin-like growth factor-II from a malignant solitary fibrous tumor of the pleura

A 49-year-old woman with a malignant solitary fibrous tumor of the pleura presented with hypoglycemia. Most of the serum insulin-like growth factor II (IGF-II) existed as high molecular weight IGF-II. Furthermore, there were larger amounts of high molecular weight IGF-II found in the tumor cystic fluid than in the serum. After surgical resection of the tumor, high molecular weight IGF-II was not detected in the serum and the hypoglycemia resolved. Immunohistochemically, IGF-II was localized in the so-called Golgi area of the tumor cell. These findings suggest that hypoglycemia in this patient was caused by the high molecular weight IGF-II produced by the tumor.

Blockade of the extracellular signal-regulated kinase pathway induces marked G1 cell cycle arrest and apoptosis in tumor cells in which the pathway is constitutively activated: up-regulation of p27(Kip1)

Constitutive activation of the ERK pathway is associated with the neoplastic phenotype of a relatively large number of human tumor cells. Blockade of the ERK pathway by treatment with PD98059, a specific inhibitor of mitogen-activated protein (MAP) kinase/ERK kinase (MEK), completely suppressed the growth of tumor cells in which the pathway is constitutively activated (RPMI-SE and HT1080 cells). Consistent with its prominent antiproliferative effect, PD98059 induced a remarkable G(1) cell cycle arrest, followed by a modest apoptotic response, in these tumor cells. Selective up-regulation of p27(Kip1) was observed after PD98059 treatment of RPMI-SE and HT1080 cells. Overexpression in RPMI-SE cells of either a kinase-negative form of MEK1 or wild-type MAP kinase phosphatase-3 also induced up-regulation of p27(Kip1). The up-regulation of p27(Kip1) correlated with increased association of p27(Kip1) with cyclin E-cyclin-dependent kinase (CDK) 2 complexes, a concomitant inhibition of cyclin E-CDK2 kinase activity, and a consequent decrease in the phosphorylation state of retinoblastoma protein, which would culminate in the marked G(1) cell cycle arrest observed in these tumor cells. These results suggest that the complete growth suppression that follows specific blockade of the ERK pathway in tumor cells in which the pathway is constitutively activated is mediated by up-regulation of p27(Kip1).

Superficial undifferentiated small cell carcinoma of the esophagus showing an interesting growing pattern in histology

We report a case of superficial undifferentiated small cell carcinoma of the esophagus. The histology of the tumor was interesting; there was squamous cell differentiation within the epithelial layer and undifferentiated small cells growing within the submucosal layer. The tumor had a negative Grimelius reaction, suggesting no differentiation into a hormone-producing carcinoma known as an apudoma (Amine Precursor Uptake and Decarboxylation (APUD)). The serum levels of ACTH and calcitonin were within normal limits. As the patient was elderly and had a history of pleural tuberculosis causing poor pulmonary function, and owing to the fulminant nature of this carcinoma, he underwent blunt dissection of the esophagus by posterior mediastinal gastric pull-up. The patient recovered quickly and was able to be discharged with a good quality of life until the tumor recurred as a liver metastasis 6 months later.

MDM2 interacts with MDMX through their RING finger domains

The N-terminus of MDM2 proto-oncoprotein interacts with p53 and down modulates p53 activity by inhibiting transcriptional activity and promoting p53 degradation. MDMX is structurally related to MDM2 and also binds to p53. However, the function of MDMX has not been clarified yet. We found that MDM2 hetero-oligomerized with MDMX through their C-terminal RING finger domains. Yeast two-hybrid analysis revealed that the hetero-oligomerization between MDMX and MDM2 was more stable than the homo-oligomerization of each protein. MDM2 has been shown to be degraded by the ubiquitin-proteasome pathway, while MDMX was a stable protein. Interaction of MDMX with MDM2 through the C-terminal RING finger domains resulted in inhibiting degradation of MDM2. These data indicate that MDMX functions as a regulator of MDM2.

[Effect of concurrent use of ondansetron hydrochloride and dexamethasone against nausea and vomiting in lung cancer patients receiving cisplatin]

We examined the efficacy of concurrent use of ondansetron hydrochloride and dexamethasone, and the effective dose of dexamethasone against nausea and vomiting in lung cancer patients receiving chemotherapy including single high dose cisplatin. The study was carried out on total of 44 courses of chemotherapy in either initial onset or recurrence of lung cancer. The patients were given 4 mg of ondansetron injection on the day of cisplatin injection (Day 1), and 4 mg/day of ondansetron tablet for Days 2 to 4. These patients were randomly allocated into 2 groups, i.e., those who, on Day 2, concomitantly received 10 mg of dexamethasone (D10 Group, 22 courses) or 20 mg (D20 Group, 22 courses), for comparing the antiemetic effects in a different concomitant dose of dexamethasone. An efficacy rate of 70% or more was achieved in each group for acute emesis on Day 1. The efficacy rate was 80% or above for emesis on Day 2 when dexamethasone was concurrently administered, and Days 3 and 4 in both groups. No significant difference was observed between the groups. A higher complete suppression rate against nausea was seen in D20 Group even though the difference from D10 Group was not significant. Furthermore, food intake rate on Day 2 was significantly better in D20 Group. However, in the cases that were graded effective or markedly effective for acute emesis on Day 1, the efficacy rate was also high in both groups through Days 2-4. It was notable that the efficacy rate of Days 2-4 was 100% in D2 Group. The high efficacy rate was shown in male patients regardless of which dose of dexamethasone was used. However, control of emesis was unfavorable in female patients on Day 1 and was still unfavorable even though dexamethasone was combined from Day 2. We considered from the above results that 10 mg/day of concurrent dexamethasone is sufficient in suppression of delayed emesis on Day 2. However, in order to improve nausea or food intake, or to suppress emesis in patients who are highly likely to show unfavorable control for Day 2 and onward, 20 mg/day should also be effective.

[Three cases of pulmonary embolism incorrectly diagnosed as lung cancer]

Pulmonary embolism is commonly misdiagnosed as lung cancer, since sputum cytological tests often show atypical or malignant cells. We report three operated cases of pulmonary embolism incorrectly diagnosed as lung cancer. The first patient is a 39-year-old male with chest pain an bloody sputum. Chest x-ray revealed abnormal shadows and subsequent sputum cytological tests identified malignant cells. The second patient is a 63-year-old male with the same diagnostic pattern as the first case. The third patient is a 72-year-old male whose routine chest x-ray showed an abnormal shadow; malignant cells were identified by cytological tests on transbronchial fiberscope brushings. These three patients were histopathologically diagnosed as suffering pulmonary embolism by wedge resection under thoracotomy. When a patient has chest pain or bloody sputum with showing temporarily malignant cells on cytology, the possibility of pulmonary embolism should be taken into consideration.

B-cell lymphoma of mucosa-associated lymphoid tissue of the thymus: a report of two cases with a background of Sjögren's syndrome and monoclonal gammopathy

Two rare cases of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) arising in the thymus are reported. Both patients (a 61-year-old man and a 75-year-old woman) were suffering from Sjögren's syndrome and immunoglobulin (Ig)A kappa monoclonal gammopathy. Mixed IgA-IgG cryoglobulinemia was also present in the male case. Tumor cells expressed IgA and kappa antibody reactive proteins identical with serum IgA kappa M. Moreover, we could demonstrate rearrangements of the immunoglobulin heavy and light chain genes, which supported the monoclonal origin of tumor cells. Immunological abnormalities improved after thymectomy in one case in which the tumor cells were confined to the thymus, but not the other with regional lymph node involvement, suggesting a causal role for the tumor. MALT lymphomas of the thymus thus appear to be associated with immunological disorders such as Sjögren's syndrome or monoclonal gammopathy.

A Janus kinase inhibitor, JAB, is an interferon-gamma-inducible gene and confers resistance to interferons

It has been shown that interferons (IFNs) exert their signals through receptor-associated Janus kinases (JAKs) and signal transducers and activators of transcription (STATs). However, molecular mechanism of regulation of IFN signaling has not been fully understood. We have reported novel cytokine-inducible SH2 protein (CIS) and JAK binding protein (JAB) family genes that can potentially modulate cytokine signaling. Here we report that JAB is strongly induced by IFN-gamma but not by IFN-beta in mouse myeloid leukemia M1 cells and NIH-3T3 fibroblasts. NIH-3T3 cells ectopically expressing JAB but not CIS3 lost responsiveness to the antiviral effect of IFN-beta and IFN-gamma. M1 leukemic cells stably expressing JAB were also resistant to IFN-gamma and IFN-beta-induced growth arrest. In both NIH-3T3 and M1 transformants expressing JAB, IFN-gamma did not induce tyrosine phosphorylation and DNA binding activity of STAT1. Moreover, IFN-gamma-induced activation of JAK1 and JAK2 and IFN-beta-induced JAK1 and Tyk2 activation were inhibited in NIH-3T3 JAB transformants. These results suggest that JAB inhibits IFN signaling by blocking JAK activity. We also found that IFN-resistant clones derived from LoVo cells and Daudi cells expressed high levels of JAB without stimulation. In IFN-resistant Daudi cells, IFN-induced STAT1 and JAK phosphorylation was partially reduced. Therefore, overexpression of JAB could be, at least in part, a mechanism of IFN resistance.

Activation of the 41/43 kDa mitogen-activated protein kinase signaling pathway is required for hepatocyte growth factor-induced cell scattering

Hepatocyte growth factor (HGF) markedly induced the spreading, dissociation and scattering of Madin-Darby canine kidney epithelial cells (MDCK) and human stomach adenocarcinoma cells (TMK1). Scattering of MDCK and TMK1 cells was induced by 12-O-tetradecanoyl-phorbol-13-acetate (PMA) and epidermal growth factor (EGF), respectively. In all these agent-stimulated cells, rapid activation of Raf-1, MAP kinase/ERK kinase (MEK), 41/43 kDa MAP kinases and p90rsk was commonly observed. In contrast, PMA neither induced the scattering nor activation of all these kinases in TMK1 cells. Pretreatment of MDCK and TMK1 cells with 2-(2-amino-3-methoxyphenyl) choromone (AMPC), a specific inhibitor of MEK, selectively inhibited the HGF-, PMA- and EGF-stimulated activities of MEK, 41/43 kDa MAP kinases and p90rsk in a dose dependent manner. AMPC-pretreatment, however, did not affect HGF-, PMA- or EGF-induced activation of Raf-1, nor HGF-induced activation of phosphatidylinositol 3-kinase in these cells. Importantly, HGF-, PMA- and EGF-induced scattering of MDCK and TMK1 cells was inhibited at doses of AMPC similar to those that gave comparable levels of inhibition of the activities of MEK, 41/43 kDa MAP kinases and p90rsk. These results suggest that activation of the 41/43 kDa MAP kinase signaling pathway is required for the motility response of MDCK and TMK1 cells induced by agents such as HGF, PMA and EGF.

[Case of multiple posterior mediastinal and retroperitoneal neurinomas]

We report a case of multiple neurinomas arising in the posterior mediastinum and the retroperitoneum. A 49-year-old man was admitted to our department for operation after an abnormal shadow appeared on routine chest X-ray film. A left adrenal tumor was found incidentally with ultrasonography at the time of a previous thoracic surgery. First, the posterior mediastinal tumor was surgically removed. Histologic diagnosis was neurinoma. After resection, endocrinologic findings were within normal limits. A left adrenal tumor was diagnosed, and surgery was performed. The tumor was separated from the adrenal gland; the histologic diagnosis was neurinoma. Neurinomas are usually solitary; multiple neurinomas are extremely rare.

[A case of rectal cancer metastatic to the tonsil]

Metastatic tumors of the tonsils are rarer than primary tumors. Few cases of metastatic tonsillar tumor have been reported. A 51-year-old man expectorated a portion of a tumor from the left side of the pharynx after an operation for cancer metastatic to the lung. Biopsy revealed that the pharyngeal tumor was rectal cancer (adenocarcinoma) metastatic to the tonsil. To our knowledge, this is the first case of primary rectal cancer metastatic to the tonsil to be reported in Japan. The clinical features of metastatic tonsillar tumor are discussed.