The efficacy and safety of pure laparoscopic liver resection for hepatocellular carcinoma in super-elderly patients over 80 years: A multicenter propensity analysis

BACKGROUND

Very few reports have evaluated the safety of laparoscopic liver resection in super-elderly patients. We assessed the short-term outcomes of laparoscopic liver resection in patients with hepatocellular carcinoma aged ≥80 years, using propensity score matching.

METHODS

We retrospectively analyzed the data of 287 patients (aged ≥80 years) who underwent liver resection for hepatocellular carcinoma at eight hospitals belonging to Hiroshima Surgical study group of Clinical Oncology, between January 2012 and December 2021. The perioperative outcomes were compared between laparoscopic and open liver resection, using propensity score matching.

RESULTS

Of the 287 patients, 83 and 204 were included in the laparoscopic and open liver resection groups, respectively. Propensity score matching was performed, and 52 patients were included in each group. The operation (p = .68) and pringle maneuver (p = .11) time were not different between the groups. There were no significant differences in the incidences of bile leakage or organ failure. The laparoscopic liver resection group had significantly less intraoperative bleeding and a lower incidence of cardiopulmonary complications (both p < .01).

CONCLUSIONS

Laparoscopic liver resection can be safely performed in elderly patients aged ≥80 years.

Prognostic impact of pre- and postoperative tumor markers in patients with intrahepatic cholangiocarcinoma

PURPOSE

The present study assessed the impact of pre- and postoperative tumor markers on the survival of patients with intrahepatic cholangiocarcinoma.

METHODS

Medical records of 73 patients with intrahepatic cholangiocarcinoma were reviewed retrospectively. The pre- and postoperative carcinoembryonic antigen and carbohydrate antigen 19-9 levels were assessed. Patient characteristics, clinicopathological factors, and prognostic factors were analyzed.

RESULTS

The median recurrence-free survival and overall survival were 30.0 and 90.9 months, respectively. A multivariate survival analysis revealed that elevated postoperative carbohydrate antigen 19-9 (p = 0.023) was the only independent poor prognostic factor. The median overall survival of patients with normal and elevated postoperative carbohydrate antigen 19-9 levels was 101.4 and 15.7 months (p < 0.001), respectively. Multivariate logistic regression identified elevated preoperative carbohydrate antigen 19-9 as an independent preoperative risk factor for elevated postoperative carbohydrate antigen 19-9. The optimal cutoff value of preoperative carbohydrate antigen 19-9 for predicting elevated postoperative carbohydrate antigen 19-9 was 40 U/mL, with a sensitivity and specificity of 92% and 87%, respectively (area under curve = 0.915).

CONCLUSIONS

Elevated postoperative carbohydrate antigen 19-9 was an independent poor prognostic factor. Preoperative predictors, such as elevated preoperative carbohydrate antigen 19-9, may indicate the need for neoadjuvant therapies to improve the survival.

Prospective Exploratory Phase I Clinical Trial Assessing the Safety of Preoperative Marking for Small Liver Tumors

Background Small tumors in liver cirrhosis are difficult to distinguish using intraoperative ultrasonography. In addition, preoperative chemotherapy for metastatic liver cancer may diminish tumor size, thus making tumors difficult to identify intraoperatively. To address such difficulties, we devised a method to mark liver tumors preoperatively to facilitate intraoperative identification. This study aimed to investigate the safety of a preoperative liver tumor marking method. Methodology This exploratory prospective clinical trial included patients with liver tumors measuring ≤20 mm requiring resection. Preoperative marking was performed by placing a coil for embolization of blood vessels near the tumor using either the transcatheter or percutaneous approach. The tumor was identified and resected by intraoperative ultrasonography based on the marker. The study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000028608). Results Overall, 19 patients (9 with primary liver cancer and 10 with metastatic tumors) were recruited. The transcatheter and percutaneous methods were used in 13 and 6 patients, respectively. Marking was not possible in two patients in the transcatheter group because the catheter could not be guided to the vicinity of the tumor. There were no marking-related complications. Hepatectomy was performed in all but one patient who was not fit for hepatectomy owing to the development of a metastatic liver tumor. The markers were adequately identified during hepatectomy. Additionally, there were no difficulties in the surgical procedure or postoperative complications. Conclusions Preoperative marking with embolization coils can be performed safely for intraoperative identification of liver nodules.

[A Case of Postoperative Peritoneal Dissemination Recurrence of CY1 Gastric Cancer with cCR after Nab-PTX Therapy]

A 72-year-old man visited his local doctor for gastric discomfort. Esophagogastroduodenoscopy revealed a type 3 tumor on the gastric antrum, and histopathological examination revealed a moderately differentiated adenocarcinoma(tub2). The patient was referred to our hospital and CT scan revealed wall thickening with contrast effect in the gastric angle but no enlarged lymph nodes in the region. The patient was diagnosed as cT3N0M0, Stage ⅡB gastric cancer and underwent open distal gastrectomy and D2 lymph node dissection. No peritoneal dissemination was observed, but intraoperative laparoscopic cytology showed Class Ⅴ. The patient was diagnosed as CY1 Stage Ⅳ gastric cancer, and treated with S-1 plus Tmab therapy starting 1 month after surgery. One year postoperative follow-up CT revealed recurrence of peritoneal disseminations, and the patient was treated with nab-PTX as a second-line therapy. Tumor shrinkage was achieved steadily, and the peritoneal disseminations disappeared at the CT after 12 courses, resulting in cCR. Thereafter, cCR continued and treatment was terminated at the 17th course. Seven years have passed since the end of chemotherapy, and the patient is still alive without recurrence.

[A Case of Postoperative Recurrence of Liver Metastasis after Gastrectomy for Gastric Cancer-No Recurrence for Five Years after Twice Liver Resections]

The patient was an 89-year-old man. He underwent laparoscopic distal gastrectomy for gastric cancer and was diagnosed as T1bN1M0, Stage ⅠB. Eight months after surgery, a CT scan showed an 18 mm-sized hypodense mass in S6 of the liver, and the patient was diagnosed with recurrent liver metastasis. He was treated with 3 courses of CapeOX therapy, and the response was judged as partial response(PR). Laparoscopic partial hepatic S6 resection was performed for the single liver metastasis. The pathological results showed liver metastasis of gastric cancer. Capecitabine was started as adjuvant chemotherapy. Nine months after surgery for liver metastasis, CT scan showed a 12 mm-sized single tumor in S5 and the patient was diagnosed with recurrent liver metastasis. The patient underwent laparoscopic partial hepatectomy after 3 courses of weekly paclitaxel plus ramucirumab therapy. The pathological result showed liver metastasis of gastric cancer. After the surgery, adjuvant chemotherapy was not administered according to the patient's request. Seven years have passed since the resection of the gastric cancer, and 5 years have passed since the resection of the second liver metastasis, and the patient has not had any recurrence.

A Multicenter, Open-Label, Single-Arm Phase I Trial of Dual-Wield Parenchymal Transection: A New Technique of Liver Resection Using the Cavitron Ultrasonic Surgical Aspirator and Water-Jet Scalpel Simultaneously (HiSCO-14 Trial)

PURPOSE

This study evaluated the safety and feasibility of a technique of liver resection named dual-wield parenchymal transection technique (DWT), using cavitron ultrasonic surgical aspirator (CUSA) and water-jet scalpel simultaneously.

METHODS

This multicenter, prospective, open-label, and single-arm phase I trial included patients aged 20 years or older with hepatic tumors indicated for surgical resection and scheduled for open radical resection. This study was conducted at two institutions affiliated with the Hiroshima Surgical Study Group of Clinical Oncology (HiSCO). The primary endpoint was the proportion of massive intraoperative blood loss (≥ 1000 mL). The secondary endpoints were the amount of blood loss, operative time, parenchymal transection speed, postoperative complications, and mortality. The safety endpoints were device failure and adverse events associated with devices.

RESULTS

From June 2022 to May 2023, 20 patients were enrolled; one was excluded and 19 were included in the full analysis set (FAS). In the FAS, segmentectomy was performed in nine cases, sectionectomy in four cases, and hemihepatectomy in six cases. Radical resection was achieved in all patients. Intraoperative blood loss greater than 1000 mL was observed in five patients (26.3%). The median amount of blood loss was 545 mL (range, 180-4413), and blood transfusions were performed on two patients (10.5%). The median operative time was 346 minutes (range, 238-543) and the median parenchymal transection speed was 1.2 cm2/minute (range, 0.5-5.1). Postoperative complications of Clavien-Dindo classification ≥ Grade 3 occurred in four patients (21.1%). No mortalities occurred in this study. In the safety analysis, there were no device failures or adverse events associated with devices.

CONCLUSIONS

This study demonstrated the safety and feasibility of DWT for liver resection. The efficacy of the DWT will be evaluated in future clinical trials.

Future prospects for cancer immunotherapy using induced pluripotent stem cell-derived dendritic cells or macrophages

Cancer immunotherapy is now the first-line treatment for many unresectable cancers. However, it remains far from a complete cure for all patients. Therefore, it is necessary to develop innovative methods for cancer immunotherapy, and immune cell therapy could be an option. Currently, several institutions are attempting to generate immune cells from induced pluripotent stem cells (iPSCs) for use in cancer immunotherapy. A method for generating dendritic cells (DCs) and macrophages (MPs) from iPSC has been established. iPSC-derived DCs (iPS-DCs) can activate T cells via antigen presentation, and iPSC-derived macrophages (iPS-MPs) attack cancer. Since iPSCs are used as the source, genetic modification is easy, and various immune functions, such as the production of anti-tumour cytokines, can be added. Furthermore, when iPS-DCs and iPS-MPs are immortalized, cost reduction through mass production is theoretically possible. In this review, the achievements of cancer research using iPS-DCs and iPS-MPs are summarized, and the prospects for the future are discussed.

Usefulness and safety of midline incision for right-sided hepatectomy: Cohort study

Background

While the adoption rates of laparoscopic hepatectomy are increasing, most patients still undergo open hepatectomy. Open hepatectomies use inverted L-shaped or Mercedes incisions for right-sided liver tumor. To decrease procedural invasiveness, we performed midline incisions in such cases, excluding those of laparoscopic hepatectomy. This retrospective study examined the effects of this change in treatment policy on overall patient surgical outcomes.

Materials and methods

From 2012 to 2018, 374 patients who underwent hepatectomy for right-sided hepatocellular carcinoma were enrolled, and short-term patient outcomes were compared following stratification into the 1st (n = 157) or 2nd (n = 217) Era group based on whether procedures occurred before or after the policy change, respectively.

Results

Short-term outcomes were mostly comparable between the two groups, with significantly increased postoperative aspartate aminotransferase maximum values found in the 2nd Era group relative to the 1st Era group (median: 393 vs. 331, p < 0.05). Pain scores at rest during postoperative day 1 and while moving on postoperative days 1, 2, and 3 were significantly lower in the 2nd Era group than in the 1st Era group (p < 0.05, <0.01, <0.05, <0.01, respectively).

Conclusions

Utilization of midline incisions may provide some benefits in postoperative outcomes for right-sided open hepatectomy cases.

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Utilization of midline incisions may provide better postoperative outcomes in cases of right-sided open hepatectomy.

Improved safety of induced pluripotent stem cell-derived antigen-presenting cell-based cancer immunotherapy

The tumorigenicity and toxicity of induced pluripotent stem cells (iPSCs) and their derivatives are major safety concerns in their clinical application. Recently, we developed granulocyte-macrophage colony-stimulating factor (GM-CSF)-producing proliferating myeloid cells (GM-pMCs) from mouse iPSCs as a source of unlimited antigen-presenting cells for use in cancer immunotherapy. As GM-pMCs are generated by introducing c-Myc and Csf2 into iPSC-derived MCs and are dependent on self-produced GM-CSF for proliferation, methods to control their proliferation after administration should be introduced to improve safety. In this study, we compared the efficacy of two promising suicide gene systems, herpes simplex virus-thymidine kinase (HSV-TK)/ganciclovir (GCV) and inducible caspase-9 (iCasp9)/AP1903, for safeguarding GM-pMCs in cancer immunotherapy. The expression of HSV-TK or iCasp9 did not impair the fundamental properties of GM-pMCs. Both of these suicide gene-expressing cells selectively underwent apoptosis after treatment with the corresponding apoptosis-inducing drug, and they were promptly eliminated in vivo. iCasp9/AP1903 induced apoptosis more efficiently than HSV-TK/GCV. Furthermore, high concentrations of GCV were toxic to cells not expressing HSV-TK, whereas AP1903 was bioinert. These results suggest that iCasp9/AP1903 is superior to HSV-TK/GCV in terms of both safety and efficacy when controlling the fate of GM-pMCs after priming antitumor immunity.

Generation of GM-CSF-producing antigen-presenting cells that induce a cytotoxic T cell-mediated antitumor response

Immunotherapy using dendritic cells (DCs) is a promising treatment modality for cancer. However, the limited number of functional DCs from peripheral blood has been linked to the unsatisfactory clinical efficacies of current DC-based cancer immunotherapies. We previously generated proliferating antigen-presenting cells (APCs) by genetically engineering myeloid cells derived from induced pluripotent stem cells (iPSC-pMCs), which offer infinite functional APCs for broad applications in cancer therapy. Herein, we aimed to further enhance the antitumor effect of these cells by genetic modification. GM-CSF gene transfer did not affect the morphology, or surface phenotype of the original iPSC-pMCs, however, it did impart good viability to iPSC-pMCs. The resultant cells induced GM-CSF-dependent CD8⁺ T cell homeostatic proliferation, thereby enhancing antigen-specific T cell priming in vitro. Administration of the tumor antigen-loaded GM-CSF-producing iPSC-pMCs (GM-pMCs) efficiently stimulated antigen-specific T cells and promoted effector cell infiltration of the tumor tissues, leading to an augmented antitumor effect. To address the potential tumorigenicity of iPSC-derived products, irradiation was applied and found to restrict the proliferation of GM-pMCs, while retaining their T cell-stimulatory capacity. Furthermore, the irradiated cells exerted an antitumor effect equivalent to that of bone marrow-derived DCs obtained from immunocompetent mice. Additionally, combination with immune checkpoint inhibitors increased the infiltration of CD8⁺ or NK1.1⁺ effector cells and decreased CD11b⁺/Gr-1⁺ cells without causing adverse effects. Hence, although GM-pMCs have certain characteristics that differ from endogenous DCs, our findings suggest the applicability of these cells for broad clinical use and will provide an unlimited source of APCs with uniform quality.

PD1 gene polymorphism is associated with a poor prognosis in hepatocellular carcinoma following liver resection, cohort study

BACKGROUND

This study examined whether single nucleotide polymorphism (SNP) in programmed cell death protein (PD)-1 is related to the postoperative prognosis of patients with hepatocellular carcinoma (HCC). The immune checkpoint protein PD-1 is an important inhibitor of T cell responses. SNP in the promoter region of PD-1 -606 G/A has been reported to result in high activation and expression of PD-1 associated with cancer risk.

MATERIALS AND METHODS

We analyzed 321 patients with HCC who underwent hepatectomy between 2010 and 2015. PD-1 SNP was analyzed by polymerase chain reaction, and the prognosis after surgical treatment of patients with HCC was analyzed.

RESULTS

The PD-1 SNP statuses were as follows: 90 AA (28.1%), 163 GA (50.8%), 68 GG (21.2%). The baseline parameters did not statistically differ between the three groups. The overall survival (OS) of patients with the GG genotype was significantly lower than that of those with the other genotypes (P = 0.031). The GG genotype was an independent risk factor for OS (P = 0.009; HR 2.201). There was no significant difference between the GG genotype and other genotypes in recurrent-free survival. The extrahepatic recurrence (EHR) rate of those with the GG genotype was significantly higher than that of those with the other genotypes (P = 0.036). The GG genotype was an independent risk factor for EHR (P = 0.008; HR 2.037).

CONCLUSIONS

The PD-1 SNP GG genotype is associated with poor survival and increased EHR in HCC. Furthermore, the GG genotype is an independent predictive factor for OS and EHR.

Independent risk factors that predict bile leakage after hepatectomy for hepatocellular carcinoma: Cohort study

BACKGROUND

Bile leakage is a major cause of morbidity after hepatectomy. This study aimed to identify the predictive factors for bile leakage after hepatectomy.

MATERIALS AND METHODS

Between January 2011 and December 2016, 556 patients underwent a liver resection for hepatocellular carcinoma with curative intent, and were enrolled to participate in this study. The incidence of postoperative bile leakage (POBL) was determined and the predictive factors for POBL were identified using univariate and multivariate analysis.

RESULTS

POBLs occurred in 28 patients (5.0%). The multivariate analysis identified a history of stereotactic body radiotherapy, a body mass index <20 kg/m², Child-Pugh class B cirrhosis, a central hepatectomy, and an operation time ≥375 min as risk factors that were associated with POBL. When the study cohort was grouped according to the number of the predictive factors present, the incidence of POBL increased as the number of the extant independent predictive factors increased. The POBL rate was 45.0% in patients with ≥3 predictive factors.

CONCLUSION

We determined that POBL was associated with operative mortality and identified five independent predictive factors associated with POBL. Risk stratification using these predictive factors may be useful for identifying patients at a high risk of POBL.

A small intestine volvulus caused by strangulation of a mesenteric lipoma: a case report

BACKGROUND

An emergency department encounters a variety of cases, including rare cases of the strangulation of a mesenteric lipoma by the greater omentum band.

CASE PRESENTATION

A 67-year-old Japanese man presented with nausea, vomiting, and upper abdominal pain. There were no abnormalities detected by routine blood tests other than a slight rise in his white cell count. A contrast-enhanced computed tomography scan of his abdomen revealed a dilated intestine, a small intestine volvulus, and a well-capsulated homogeneous mass. He was suspected of having a small intestine volvulus that was affected by a mesenteric lipoma; therefore, single-port laparoscopic surgery was performed. Laparoscopy revealed a small intestine volvulus secondary to the strangulation of a mesenteric lipoma. The band and tumor were removed. He had no postoperative complications and was discharged on postoperative day 6.

CONCLUSIONS

Although this case was an emergency, it showed that single-port laparoscopic surgery can be a safe, useful, and efficacious procedure.

De Garengeot hernia with perforated appendicitis and a groin subcutaneous abscess: A case report

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De Garengeot hernia with a groin subcutaneous abscess is rare.

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Appendectomy and herniorrhaphy via the same incision may be more effective.

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Clinicians should consider de Garengeot hernia in patients with a groin hernia.

Introduction

De Garengeot hernia is rare. Although previous reports have suggested various surgical options according to patient condition, comorbidities, surgeon preference, and clinical findings during surgery, a treatment strategy has not been established.

Presentation of case

An 81-year-old woman presented with an irreducible tender mass that was subsequently diagnosed as an incarcerated femoral hernia with a subcutaneous abscess in the right groin. Intraoperative findings revealed a necrotic and perforated appendix strangulated by the femoral ring for which an appendectomy and herniorrhaphy was performed concurrently through the hernia sac. The subcutaneous abscess cavity was washed thoroughly and a drainage tube was placed within it. The patient recovered uneventfully.

Discussion

We suggest that the approach through the inguinal incision in both appendectomy and herniorrhaphy with drainage may be useful in avoiding intra-abdominal contamination in cases of de Garengeot hernia with subcutaneous abscess.

Conclusion

Here, we described a case of de Garengeot hernia with a subcutaneous abscess in the groin. Clinicians should consider de Garengeot hernia in patients with a groin hernia, make an early diagnosis, and promptly provide surgical treatment to reduce the risk of complications.

[Estimation of peritoneal dissemination in patients with unresectable advanced or recurrent colorectal cancer who underwent curative resection after combination chemotherapy]

In a group of 209 colorectal cancer patients with unresectable tumors, 10 patients underwent curative resection after combination chemotherapy at our hospital between 2006 and 2012. Of these 10 patients, 5 presented with peritoneal dissemination at the start of chemotherapy. With the exception of 1 patient with peritoneal recurrence, peritoneal dissemination and liver metastasis were observed in all patients at the time of diagnosis of colorectal cancer. Computed tomography (CT) and/ or positron emission tomography-CT examination revealed disappearance of peritoneal dissemination in response to chemotherapy, except in 1 patient with peritoneal recurrence. After combination chemotherapy, surgical resection of liver metastases and peritoneal dissemination was performed. Pathological and intraoperative findings indicated disappearance of peritoneal dissemination in 3 patients and P2 grade peritoneal dissemination in 1 patient. In the patient with peritoneal recurrence, 1 tumor was completely resected. Interestingly, none of the 3 patients that exhibited complete disappearance of peritoneal dissemination showed peritoneal recurrence, although 1 patient exhibited metastases in the lung and non-regional lymph nodes. In contrast, the patient with P2 grade peritoneal dissemination showed peritoneal recurrence and lung metastasis. All 5 patients survived (duration from diagnosis of colorectal cancer, 31-83 months). Herein, we report the use of combination chemotherapy to achieve the disappearance of peritoneal dissemination, changing unresectable colorectal cancer with peritoneal dissemination into resectable cancer.

Activin A is an autocrine activator of rat pancreatic stellate cells: potential therapeutic role of follistatin for pancreatic fibrosis

BACKGROUND AND AIM

The present study was conducted to examine the effect of activin A on activation of rat pancreatic stellate cells (PSCs).

METHODS

PSCs were prepared from rat pancreas using collagenase digestion and centrifugation with Nycodenz gradient. Activation of PSCs was examined by determining smooth muscle actin expression with western blotting. The presence of activin A receptors in PSCs was investigated by reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and immunocytochemistry. Expression of activin A and transforming growth factor beta (TGF-beta) mRNA was examined by RT-PCR. Activin A and TGF-beta peptide concentrations were examined with ELISA. Existence of activin A peptide in PSCs was investigated by immunocytochemistry. Collagen secretion was determined by Sirius red dye binding.

RESULTS

Activin A receptors I and IIa were present in PSCs. PSCs expressed activin A mRNA and secreted activin A. Activin A enhanced PSC activation and collagen secretion in a dose dependent manner. TGF-beta and activin A increased each other's secretion and mRNA expression of PSCs. Follistatin decreased TGF-beta mRNA expression and TGF-beta secretion of PSCs, and inhibited both PSC activation and collagen secretion.

CONCLUSION

Activin A is an autocrine activator of PSCs. Follistatin can inhibit PSC activation and collagen secretion by blocking autocrined activin A and decreasing TGF-beta expression and secretion of PSCs.

Smad7 is induced by norepinephrine and protects rat hepatocytes from activin A-induced growth inhibition

Activin A induces growth arrest of rat hepatocytes in vitro and in vivo. The alpha(1)-adrenergic agonist, norepinephrine (NE), enhances epidermal growth factor-stimulated DNA synthesis and inhibits activin A-induced growth inhibition, but the mechanisms of these actions are unclear. Smad proteins have recently been identified as intracellular signaling mediators of transforming growth factor-beta family members. In the present study, we explored how NE modulates the Smad signaling pathway in rat cultured hepatocytes. We demonstrate that NE inhibits activin A-induced nuclear accumulation of Smad2/3 and that NE rapidly induces inhibitory Smad7 mRNA expression. Infection of Smad7 adenovirus into rat hepatocytes inhibited activin A-induced nuclear accumulation of Smad2/3, enhanced epidermal growth factor-stimulated DNA synthesis, and abolished the growth inhibitory effect of activin A. We also demonstrated that the induction of Smad7 by NE is dependent on nuclear factor-kappa B (NF-kappa B). The amount of active NF-kappa B complex rapidly increased after NE treatment. Preincubation of the cells with an NF-kappa B pathway inhibitor N-tosyl-l-phenylalanine chloromethyl ketone or infection of the cells with an adenovirus expressing an I kappa B super-repressor (Ad5I kappa B) abolished the NE-induced Smad7 expression. These results indicate a mechanism of transmodulation between the Smad and trimeric G protein signaling pathways in rat hepatocytes.

Dynamin is involved in human epithelial cell vacuolation caused by the Helicobacter pylori-produced cytotoxin VacA

The Helicobacter pylori-produced cytotoxin VacA induces intracellular vacuolation. To elucidate the molecular mechanism of vacuole formation by VacA, we examined the participation of dynamin, a GTPase functioning in intracellular vesicle formation, in human HeLa cells. Immunocytochemistry revealed that endogenous dynamin was localized to vacuoles induced by VacA. In cells transiently transfected with a GTPase-defective (dominant-negative) dynamin mutant, VacA failed to induce vacuolation. In contrast, VacA did induce vacuolation in cells transiently transfected with wild-type dynamin. Furthermore, under VacA treatment, neutral red dye uptake, a parameter of VacA-induced vacuolation, was inhibited in cells stably transfected with the dominant-negative dynamin mutant. In contrast, uptake was markedly enhanced in cells stably transfected with wild-type dynamin. Moreover, VacA cytopathic effects on the viability of HeLa cells were inhibited in cells stably transfected with dominant-negative dynamin-1. Sequential immunocytochemical observation confirmed that expression of dominant-negative dynamin did not affect VacA attachment to or internalization into HeLa cells. We suggest that dynamin is involved in the intracellular vacuolation induced by VacA.

Changes in the expression of transcription factors in pancreatic AR42J cells during differentiation into insulin-producing cells

Pancreatic AR42J cells possess both exocrine and neuroendocrine properties and convert to insulin-producing cells upon treatment with activin A and hepatocyte growth factor (HGF). We studied changes in the mRNA expression of various transcription factors during the course of differentiation. Among the transcription factors studied, expression levels of Pax4 and neurogenin3 changed significantly. These two factors were not detected in naive cells, whereas their mRNA levels were markedly increased after treatment with activin A and HGF. Thus, these two factors were induced by activin A. Transfection of Pax4 did not induce any changes in morphology or expression of pancreatic polypeptide (PP). Furthermore, introduction of antisense Pax4 did not affect the conversion into insulin-producing cells induced by activin A and HGF. In contrast, transfection of neurogenin3 induced morphological changes similar to those induced by activin A. In addition, transfection of neurogenin3 induced the expression of PP. Conversely, introduction of antisense neurogenin3 blocked the differentiation of AR42J cells induced by activin A and HGF. These results indicate that activin A regulates the expression of neurogenin3, which is critical for the differentiation of AR42J into endocrine cells.

Scale up of fuel ethanol production from sugar beet juice using loofa sponge immobilized bioreactor

Production of fuel ethanol from sugar beet juice, using cells immobilized on loofa sponge was investigated. Based on ethanol productivity and ease of cell immobilization, a flocculating yeast strain, Saccharomyces cerevisiae IR2 was selected for ethanol production from sugar beet juice. It was found that raw sugar beet juice was an optimal substrate for ethanol production, requiring neither pH adjustment nor nitrogen source supplement. When compared with a 2 l bubble column bioreactor, mixing was not sufficient in an 8 l bioreactor containing a bed of sliced loofa sponges and consequently, the immobilized cells were not uniformly distributed within the bed. Most of the cells were immobilized in the lower part of the bed and this resulted in decreased ethanol productivity. By using an external loop bioreactor, constructing the fixed bed with cylindrical loofa sponges, dividing the bed into upper, middle and lower sections with approximately 1 cm spaces between them and circulating the broth through the loop during the immobilization, uniform cell distribution within the bed was achieved. Using this method, the system was scaled up to 50 l and when compared with the 2 l bubble column bioreactor, there were no significant differences (P > 0.05) in ethanol productivity and yield. By using external loop bioreactor to immobilize the cells uniformly on the loofa sponge beds, efficient large scale ethanol production systems can be constructed.

Kinesin is involved in regulation of rat pancreatic amylase secretion

BACKGROUND & AIMS

Kinesin has recently been localized to zymogen granules of pancreatic acini and is suggested to participate in exocytosis of exocrine pancreas. We examined the function of kinesin in regulated exocytosis of pancreatic acini in this study.

METHODS

Kinesin function in exocytosis was examined by introducing hexahistidine-tagged recombinant kinesin protein and antikinesin monoclonal antibody into streptolysin-O-permeabilized acini. Intracellular localization of introduced recombinant kinesin was investigated by immunohistochemistry. Interaction between recombinant kinesin and the microtubule network was confirmed by nocodazole pretreatment of acini. Kinesin regulation by secretagogues was investigated by examining their effect on adenosine triphosphatase (ATPase) activity of endogenous kinesin.

RESULTS

Recombinant kinesin enhanced calcium-stimulated amylase release from streptolysin-O-permeabilized acini. Introduced recombinant kinesin was localized to both the microtubule network and zymogen granule. Nocodazole pretreatment of acini abolished the enhancing effect of recombinant kinesin on calcium-stimulated amylase release. Antikinesin antibody inhibited amylase release stimulated by the combination of calcium and cyclic adenosine monophosphate (cAMP) but not that stimulated by calcium alone. Secretin and 8-bromo-cAMP increased ATPase activity of endogenous kinesin.

CONCLUSIONS

Kinesin plays a stimulatory role in regulated exocytosis of pancreatic acini and is involved in stimulus-secretion coupling through a cAMP-dependent pathway.

Genetic variation in the gene encoding calpain-10 is associated with type 2 diabetes mellitus

Type 2 or non-insulin-dependent diabetes mellitus (NIDDM) is the most common form of diabetes worldwide, affecting approximately 4% of the world's adult population. It is multifactorial in origin with both genetic and environmental factors contributing to its development. A genome-wide screen for type 2 diabetes genes carried out in Mexican Americans localized a susceptibility gene, designated NIDDM1, to chromosome 2. Here we describe the positional cloning of a gene located in the NIDDM1 region that shows association with type 2 diabetes in Mexican Americans and a Northern European population from the Botnia region of Finland. This putative diabetes-susceptibility gene encodes a ubiquitously expressed member of the calpain-like cysteine protease family, calpain-10 (CAPN10). This finding suggests a novel pathway that may contribute to the development of type 2 diabetes.

Molecular cloning of a novel brain-type Na(+)-dependent inorganic phosphate cotransporter

We have isolated a human cDNA encoding a protein, designated DNPI, that shows 82% amino acid identity and 92% similarity to the human brain-specific Na(+)-dependent inorganic phosphate (Na(+)/P(i)) cotransporter (BNPI), which is localized exclusively to neuron-rich regions. Expression of DNPI mRNA in Xenopus oocytes resulted in a significant increase in Na(+)-dependent P(i) transport, indicating that DNPI is a novel Na(+)/P(i) cotransporter. Northern blot analysis shows that DNPI mRNA is expressed predominantly in brain, where the highest levels are observed in medulla, substantia nigra, subthalamic nucleus, and thalamus, all of which express BNPI mRNA at low levels. In contrast, DNPI mRNA is expressed at low levels in cerebellum and hippocampus, where BNPI mRNA is expressed at high levels. No hybridizing signal for DNPI mRNA is observed in the glia-rich region of corpus callosum. In other regions examined, both mRNAs are moderately or highly expressed. These results indicate that BNPI and DNPI, which coordinate Na(+)-dependent P(i) transport in the neuron-rich regions of the brain, may form a new class within the Na(+)/P(i) cotransporter family.

Translocation of a calcium-permeable cation channel induced by insulin-like growth factor-I

Calcium plays a critical part in the regulation of cell growth, and growth factors stimulate calcium entry into cells through calcium-permeable channels. However, the molecular nature and regulation of calcium-permeable channels are still unclear at present. Here we report the molecular characterization of a calcium-permeable cation channel that is regulated by insulin-like growth factor-I (IGF-I). This channel, which we name growth-factor-regulated channel (GRC), belongs to the TRP-channel family and localizes mainly to intracellular pools under basal conditions. Upon stimulation of cells by IGF-I, GRC translocates to the plasma membrane. Thus, IGF-I augments calcium entry through GRC by regulating trafficking of the channel.

Genes expressed during the differentiation of pancreatic AR42J cells into insulin-secreting cells

Pancreatic AR42J cells have the feature of pluripotency of the common precursor cells of the pancreas. Dexamethasone (Dx) converts them to exocrine cells, whereas activin A (Act) converts them into endocrine cells expressing pancreatic polypeptide. A combination of Act and betacellulin (BTC) converts them further into insulin-secreting cells. The present study identifies some of the genes involved in the process of differentiation that is induced by these factors, using the mRNA differential display and screening of the cDNA expression array. The expression levels of 7 genes were increased by Act alone, and a combination of Act and BTC increased the expression of 25 more genes. Of these, 16 represented known genes or homologues of genes characterized previously. Nine of the identified genes were unrelated to any other sequences in the database. An inhibitor of the mitogen-activated protein kinase pathway, PD098059, which blocks the differentiation into insulin-secreting cells, inhibited the expression of 18 of the 25 genes, suggesting that the proteins encoded by these genes are associated with the differentiation into insulin-producing cells. These include known genes encoding extracellular signaling molecules, such as parathyroid hormone-related peptide, cytoskeletal proteins, and intracellular signaling molecules. Identification and characterization of these differentially expressed genes should help to clarify the molecular mechanism of differentiation of pancreatic cells and the gene products that enable the beta-cells to produce insulin.

Assessment of the role of activin A and transforming growth factor beta in the regulation of AML12 cell growth

The present study was conducted to determine the role of two autocrine factors, activin A and transforming growth factor beta (TGF-beta), in the growth regulation of AML12 hepatocytes. We overexpressed truncated type II activin and/or TGF-beta receptors in AML12 cells. In AML12 cells overexpressing truncated type II activin receptors (AML-tAR cells), the inhibitory effect of activin A on DNA synthesis was completely blocked. AML-tAR cells proliferated faster than parental cells, both in the presence and absence of epidermal growth factor (EGF). However, AML-tAR cells could not grow in soft agar. Follistatin augmented EGF-induced DNA synthesis in AML12 cells, whereas it was ineffective in AML-tAR cells. In AML12 cells overexpressing truncated type II TGF-beta receptor (AML-tTR cells), the inhibitory effect of TGF-beta on DNA synthesis was blocked. AML-tTR cells proliferated faster than parental cells, both in the presence and absence of EGF, but at a slower rate than that of AML-tAR cells. AML-tTR cells did not grow in soft agar. The growth rate of cells overexpressing both types of truncated receptors was identical to that of AML-tAR cells, and these cells did not grow in soft agar. These results indicate that both activin A and TGF-beta act as autocrine inhibitors of DNA synthesis in AML12 cells, and that the blocking of the actions of two factors does not lead to transformation. Activin A is a predominant autocrine factor in these cells.

Formation of insulin-producing cells from pancreatic acinar AR42J cells by hepatocyte growth factor

Pancreatic AR42J cells are derived from acinar cells and express both exocrine and neuroendocrine properties. We have recently shown that these cells convert into insulin-producing cells in vitro after treatment with activin A and betacellulin. Here, we investigated the effect of hepatocyte growth factor (HGF) in those cells. When AR42J cells were incubated with HGF, DNA synthesis was attenuated, and the amylase content was reduced in a concentration-dependent manner. HGF-treated cells extended processes, but bundle formation was not observed using an antibody against tubulin. Reverse both insulin and pancreatic polypeptide (PP) were expressed in HGF-treated, but not naive, AR42J cells. Immunocytochemical analysis indicated that approximately 3% of the HGF-treated cells were stained with antiinsulin antibody, and some were also stained with anti-PP antibody. When AR42J cells were exposed to a combination of activin A and HGF, cells extended longer processes, and over 10% of them were stained with antiinsulin antibody. In these cells, messenger RNAs for insulin, PP, glucose transporter 2, and glucokinase, but not those for glucagon or somatostatin, were expressed. A subclone of AR42J cells, AR42J-B13, was obtained. Most of the AR42J-B13 cells converted to insulin-producing cells after the incubation with activin A and HGF. Insulin secretion was augmented by tolbutamide, depolarizing concentrations of potassium, carbachol, and glucagon-like peptide-1 in these cells. These results indicate that HGF reduces the acinar cell-like property of AR42J cells and converts them into insulin-producing cells. The effect of HGF was markedly enhanced by activin A.

Characterization of the activin receptor in cultured rat hepatocytes

Activin A is an autocrine inhibitor of initiation of DNA synthesis in rat hepatocytes. The present study was conducted to characterize the cell-surface receptors for activin A in cultured rat hepatocytes by measuring 125I-activin A binding. Scatchard analysis of 125I-activin A binding indicated the existence of two classes of binding sites with apparent Kd values of 3 x 10(-10) mol/L and 3.5 x 10(-9) mol/L. Pretreatment of the cells with heparitinase reduced the number of low-affinity binding sites, whereas pretreatment with excess exogenous follistatin increased the number of low-affinity binding sites. Affinity cross-linking of 125I-activin A to hepatocytes revealed distinct protein complexes with molecular weights of approximately 48, 65, and 85 kd, which may represent cross-linked cell-bound follistatin, type I and type II activin receptors, respectively. Another band with a molecular weight of 180 kd was also found, which may represent the type III activin receptor. When hepatocytes were cultured with epidermal growth factor (EGF), both high- and low-affinity binding sites increased at 12 hours without altering their affinities. At 60 hours of the incubation with EGF, the high-affinity binding sites decreased while the number of low-affinity binding sites increased slightly. These results indicate that two classes of 125I-activin A binding sites exist in cultured hepatocytes: the high-affinity binding site may represent oligomeric complex of the type I and type II receptors, and at least part of the low-affinity binding site may represent cell-bound follistatin. The number of activin receptors in hepatocytes is increased after the stimulation with EGF.

Betacellulin and activin A coordinately convert amylase-secreting pancreatic AR42J cells into insulin-secreting cells

Rat pancreatic AR42J cells possess exocrine and neuroendocrine properties. Activin A induces morphological changes and converts them into neuron-like cells. In activin-treated cells, mRNA for pancreatic polypeptide (PP) but not that for either insulin or glucagon was detected by reverse transcription-PCR. About 25% of the cells were stained by anti-PP antibody. When AR42J cells were incubated with betacellulin, a small portion of the cells were stained positively with antiinsulin and anti-PP antibodies. The effect of betacellulin was dose dependent, being maximal at 2 nM. Approximately 4% of the cells became insulin positive at this concentration, and mRNAs for insulin and PP were detected. When AR42J cells were incubated with a combination of betacellulin and activin A, approximately 10% of the cells became insulin positive. Morphologically, the insulin-positive cells were composed of two types of cells: neuron-like and round-shaped cells. Immunoreactive PP was found in the latter type of cells. The mRNAs for insulin, PP, glucose transporter 2, and glucokinase, but not glucagon, were detected. Depolarizing concentration of potassium, tolbutamide, carbachol, and glucagon-like peptide-1 stimulated the release of immunoreactive insulin. These results indicate that betacellulin and activin A convert amylase-secreting AR42J cells into cells secreting insulin. AR42J cells provide a model system to study the formation of pancreatic endocrine cells.

Norepinephrine reverses the effects of activin A on DNA synthesis and apoptosis in cultured rat hepatocytes

Activin A, an autocrine factor produced by hepatocytes, inhibits mitogen-stimulated DNA synthesis and induces apoptotic death of cultured rat hepatocytes. Several lines of evidence indicate that norepinephrine (NE), as a comitogenic growth factor, alters the balance between growth stimulation and inhibition and acts as a trigger for the initiation of hepatocyte proliferation. In the present study, we examined whether NE modulated the effects of activin A on rat hepatocytes in primary culture. Activin A, at a concentration of 10(-9) mol/L, blocked the effect of epidermal growth factor (EGF) on DNA synthesis, that was assessed by measuring [3H] thymidine incorporation and nuclear labeling, almost completely, and NE reversed the inhibitory effect of activin A on DNA synthesis. This effect of NE was dose-dependent, being significant at concentrations of 10(-6) mol/L and above, but was overcome by higher concentrations of activin A, and was attenuated by prazosin, but not by yohimbine or propranolol. NE exerted its effect during the first 24 hours of culture, but was ineffective when added after 24 hours. EGF augmented the release of follistatin, an activin-binding protein known to block the action of activin A, by hepatocytes and NE did not affect the amount of follistatin they released. In addition to inhibiting DNA synthesis by hepatocytes cultured with EGF, activin A induced death of hepatocytes cultured in the absence of EGF. The nuclear morphology of cells cultured with activin A alone was strikingly changed compared with untreated control cells and marked identation of the nuclear membranes and moderate chromatin condensation were observed. Fragmentation of DNA was also observed, suggesting that activin A induced apoptosis, and activin-mediated cell death was prevented significantly by NE. These results indicate that NE, acting on alpha 1-adrenergic receptors, attenuates the effects of activin A on DNA synthesis by and apoptosis of cultured rat hepatocytes.

Production of activin A in human intestinal epithelial cell line

Production of activin was studied in four cell lines of epithelial cells: FRTL-5, JCT-12, GH4C1, and FHs74Int cells. Bioactivity of activin was detected in conditioned media of FRTL-5, JCT-12, and FHs74Int cells. Among these three cell lines, FHs74Int cells, which were derived from human embryonic intestine, released a relatively f1p4e amount of bioactive activin. In these cells, serum and epidermal growth factor (EGF), which were capable of stimulating DNA synthesis, augmented release of bioactive activin in middle to late G1 phase. In addition, basic FGF (bFGF), which had no effect on DNA synthesis in these cells, also increased release of activin. In bFGF-treated FHs74Int cells, bioactive activin was released within 4 hr of the addition of bFGF. The reverse-transcription polymerase chain reaction reveals that mRNA for only the beta A subunit of activin is expressed in these cells. Immunoblotting of lysate from serum-treated cells using anti-human activin A antibody indicated the existence of a 12.5-kDa protein under a reducing condition. FHs74Int cells did not express binding site for [125I]activin A and exogenous activin A did not affect DNA synthesis in these cells. These results indicate that FHs74Int cells derived from human embryonic intestine synthesize and release activin A. Activin A released from intestinal epithelial cells might be a modulatory factor in cells in intestinal mucosa.

Conversion of amylase-secreting rat pancreatic AR42J cells to neuronlike cells by activin A

When AR42J cells, an amylase-secreting pancreatic exocrine cell line, were treated with activin A, cells extended neuritelike processes, and, concomitantly, amylase-containing vesicles disappeared. Immunofluorescence and immunoelectron microscopy revealed that these processes had neurite-specific cytoskeletal architectures: neurofilaments and microtubule bundles with cross-bridges of microtubule-associated protein 2. In addition to such morphological changes, activin-treated cells exhibited a marked increase in cytoplasmic free calcium concentration in response to depolarizing concentration of potassium. Moreover, activin-treated AR42J cells expressed mRNA for alpha 1 subunit of the neuroendocrine/beta cell-type voltage-dependent calcium channel. In naive AR42J cells, a sulfonylurea compound, tolbutamide, did not affect free calcium concentration, while it induced a marked elevation of free calcium in activin-treated cells. Single channel recording of the membrane patch revealed the existence of ATP-sensitive potassium channel in activin-treated cells. These results indicate that activin A converts amylase-secreting AR42J cells to neuronlike cells. Given that pancreatic endocrine cells possess neuronlike properties and express ATP-sensitive potassium channel as well as neuroendocrine/beta cell-type voltage-dependent calcium channel, activin treatment of AR42J cells may provide an in vitro model system to study the conversion of pancreatic exocrine cells to endocrine cells in islets.

Derangements in the activin-follistatin system in hepatoma cells

BACKGROUND/AIMS

The growth of normal hepatocytes is regulated by the activin-follistatin system. The aim of this study was to investigate the activin-follistatin system in hepatoma cells.

METHODS

The production and action of activin and follistatin in human hepatoma cell lines were examined. Activin A and follistatin were measured by bioassay and protein-binding assay, respectively.

RESULTS

Activin A inhibited cell growth in HepG2 cells but not in either PLC/PRF/5 or HLE cells. However, the effect of activin A in HepG2 cells was attenuated at high cell density. In HepG2 cells, two classes of activin-binding sites were expressed, and affinity cross-linking showed that 125I-activin A bound specifically to three proteins with molecular weights of 48, 67, and 94 kilodaltons. In PLC/PRF/5 cells, a single class of binding site was observed, and the binding capacity was approximately 60% of the capacity in HepG2 cells. Virtually no 125I-activin A binding was detected in HLE cells. Bioactivity and messenger RNA for activin A were undetectable in three cell lines. In contrast, follistatin was released from three cell lines.

CONCLUSIONS

Multiple alterations in the activin-follistatin system were found in three hepatoma cell lines. The accelerated growth observed in hepatoma cells may be caused, at least partly, by the attenuation of the action of activin A.

The effect of lansoprazole treatment on the healing and relapse of peptic ulcer and serum levels of IgG anti-Helicobacter pylori antibody

In the present study, the effects of short-term treatment with lansoprazole on healing and recurrence of peptic ulcer were investigated. Complete healing (change to the S2 stage) after 3 or 4 weeks of treatment with lansoprazole was observed in 9.9% of gastric ulcers and 38.3% of duodenal ulcers. Complete healing was observed after 3 or 4 weeks of treatment with lansoprazole in gastric ulcers and was significantly related to the serum titer of IgG anti-Helicobacter pylori antibodies. This was not the case in duodenal ulcers. Complete healing after 6 or 8 weeks of treatment with lansoprazole was not dependent on serum levels of IgG anti-H. pylori antibodies. Short-term treatment by lansoprazole did not affect serum levels of IgG anti-H. pylori antibodies immediately after the end of lansoprazole treatment, but significantly reduced serum levels of IgG anti-H. pylori antibodies were found 9 months after treatment.

A case of hepatocolic fistula after percutaneous drainage for a gas-containing pyogenic liver abscess

We describe a rare case of gas-containing pyogenic liver abscess which penetrated the adjacent colon, forming a hepatocolic fistula, after percutaneous transhepatic abscess drainage (PTAD) had been performed. To the best of our knowledge, this is the first report of hepatocolic fistula associated with a gas-forming liver abscess in a diabetic patient, with radiological and surgical confirmation of the fistula.

Activin A: negative regulator of amylase secretion and cell proliferation in rat pancreatic acinar AR42J cells

Activin A, a member of the transforming growth factor-beta supergene family, exists in secretory granules of non-B-cells of rat pancreatic islet (H. Yasuda, K. Inoue, H. Shibata, T. Takeuchi, Y. Eto, Y. Hasegawa, N. Sekine, Y. Totsuka, T. Mine, E. Ogata, and I. Kojima. Endocrinology 133: 624-630, 1993). Because functions of exocrine pancreas are influenced by hormones in pancreatic islet, it is possible that activin A affects the function of pancreatic acinar cells. To examine this possibility, we studied the effects of activin A on amylase secretion and DNA synthesis in AR42J cells. In these cells, dexamethasone (Dx) induces increases in secretory organelles and secretion of amylase (C. D. Logsdon, J. Moessner, J. A. Williams, and I. D. Goldfine. J. Cell Biol. 100: 1200-1208 1985). Activin A did not change the rate of amylase release by itself nor affect the cholecystokinin-stimulated amylase release from Dx-treated differentiated AR42J cells. However, when activin A was added together with Dx, activin A inhibited Dx-induced increase in amylase content in a dose-dependent manner. In the presence of 1 nM activin A, the effect of Dx was abolished. In the absence of Dx, amylase content of the cells was also reduced by activin A in a dose-dependent manner. The maximum inhibitory effect was obtained by 10 nM activin A, and at this concentration amylase content became undetectable. In addition, activin A potently inhibited DNA synthesis as assessed by [3H]thymidine incorporation.(ABSTRACT TRUNCATED AT 250 WORDS)

Healing of chronic gastric ulcer depends on gastric mucosal prostaglandin synthesis

In the present study, the role of endogenous prostanoid synthesis in gastric mucosa in the healing of chronic gastric ulcers was investigated. Nineteen patients were divided into two groups in accordance with healing state after one month of treatment with cimetidine only: "healed group" and "unhealed group". Biopsy specimens taken from the mucosa around the ulceration (damaged gastric mucosa) and at a distance from the ulceration (normal gastric mucosa) at endoscopy prior to treatment were homogenized, and the mucosal prostanoid synthesis was determined using [14C]arachidonic acid. The mean value of prostaglandin E2 synthesis in the normal gastric mucosa of the healed group was 60% higher than in that of the unhealed group, but the difference was not significant. However, prostaglandin E2 synthesis in the damaged gastric mucosa of the healed group was 117% higher than in that of the unhealed group. The same tendency was observed for prostaglandin D2 and 6-keto prostaglandin F1 alpha synthesis as for prostaglandin E2. In our study it was demonstrated that there is a good correlation of prostaglandin synthesis in the damaged mucosa with healing of chronic gastric ulceration. Furthermore, our study indicated that prostaglandin synthesis, especially in damaged mucosa, might be important in the healing of gastric ulceration.

An unusual presentation of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing pyogenic liver abscess: report of a case

We describe a rare case of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing pyogenic liver abscess in a 59-year-old man. The patient was diagnosed as having a hollow viscus perforation based on a sudden onset of acute abdominal pain along with radiological evidence of bilateral subphrenic feee air (pneumoperitoneum), and underwent an emergency laparotomy. Contrary to expectations, the surgery revealed no perforations of the hollow viscus, but instead a ruptured liver abscess at the dome of the right hepatic lobe was identified associated with suppurative peritonitis. To the best of our knowledge, such a case of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing liver abscess is extremely rare.

[Clinical study on the effect of continuous transarterial infusion chemotherapy of CDDP for metastatic liver tumors]

Thirteen patients with unresectable liver tumors, including 7 colorectal cancers, 5 gastric cancers, and 1 breast cancer, were treated by intraarterial continuous infusion of CDDP using an implantable reservoir. The catheter was placed by direct insertion at laparotomy (7 cases) or through the inferior epigastric artery (6 cases). The clinical antitumor effects were evaluated by CT-scan or ultrasonography. One CR, 6 PR, and 6 NC were observed among the thirteen patients, respectively. The response rate for all cases was 53.8%, which is evidently higher than that of previously reported "one shot" transarterial MMC and 5-FU infusion chemotherapy. Since this treatment method induces little side effects, it can be maintained in outpatient clinics. Thus, we concluded that this treatment could be useful to improve the quality of life of patients with unresectable liver tumors.

[Intra-arterial chemotherapy with granulocyte colony-stimulating factor for breast cancer before surgical treatment]

Intra-arterial chemotherapy (IAC) for far advanced breast cancer is now performed as a routine adjuvant chemotherapy before surgical treatment. However, the following problems remain unsolved; (1) serious adverse reactions such as myelosuppression, (2) unsuccessful insertion of catheter into the internal thoracic artery, and (3) long waiting-period from IAC to surgical treatment. The present studies were conducted to evaluate the utility of a one-route IAC, in which the subclavian artery alone is used, and the efficacy of granulocyte colony-stimulating factor (G-CSF). There was no significant difference in the antitumor effect between the patients with two-route IAC, in which both internal thoracic artery and subclavian artery are used, and the patients with one-route IAC. Administration of G-CSF in combination with IAC reduced both the frequency and the severity of IAC-induced side effects. G-CSF administration during IAC was more effective than after IAC. G-CSF prevented IAC-induced myelo-suppression and/or accelerated recovery from this complication and thus reduced significantly the waiting-period before surgical treatment.

[Studies on pruritus in obstructive jaundice cases with special references to serum bile acid fractions]

About, 22 cases with pruritus and 18 cases without pruritus of obstructive jaundice, serum bile acids were analysed quantitatively by high performance liquid chromatography (HPLC) before and after biliary decompression for the study on the relationship between pruritus and non-pruritus group. Analysis was also carried out on 11 cases with normal liver function as the control group. And 15 kinds of bile acids were as followed: unconjugates (ursodeoxycholic: UDCA, cholic: CA, chenodeoxycholic: CDCA, deoxycholic: DCA, lithocholic acid: LCA), glycine conjugates (Gly-UDCA, Gly-CA, Gly-CDCA, Gly-DCA, Gly-LCA) and taurine conjugates (Tau-UDCA, Tau-CA, Tau-CDCA, Tau-DCA, Tau-LCA). Data was analysed by t-test statistically. [I] Before biliary decompression (1) No significant difference was observed between the pruritus group and non-pruritus group about total bile acid level, total unconjugates level and CA/CDCA ratio. (2) On total glycine-conjugates level the pruritus group was significantly lower than the non-pruritus group, that level was about 3/5. Similarly on Gly-CA level was about 2/3, on Gly-CDCA level was about 1/2. (3) By contraries on total taurine-conjugates level the pruritus group was significantly high as compared with the non-pruritus group, that level was about two times. Similarly on Tau-CA and Tau-CDCA levels were about two times. (4) From there results on glycine/taurine ratio (G/T) of total bile acids pruritus group was significantly low as compared with the non-pruritus group, that level was about 1/3. Similarly on G/T ratio of CA level was about 2/5 and on G/T ratio of CDCA was about 1/3. (5) As for various unconjugates, UDCA level was significantly high in pruritus group as compared with non-pruritus group. [II] After biliary decompression No significant difference was shown in the composition of serum bile acids between the pruritus group and the non-pruritus group. These studies showed that the pruritus in the obstructive jaundice cases stood in a certain relation to the increase of taurine-conjugates, especially taurine-conjugated CA and taurine-conjugated CDCA, moreover increase of unconjugated UDCA.

[Trans-arterial infusion chemotherapy through the inferior epigastric artery for malignant abdominal tumors without laparotomy]

A new technique of intra-arterial catheterization through the inferior epigastric artery using a subcutaneously-implanted silicon reservoir was tried for arterial infusion chemotherapy in patients with cancer located in specific lesions. Eight surgically uncontrollable tumors, consisting of 6 hepatic metastasis, one surgically incurable gastric cancer and one recurrent rectal cancer, were treated by continuous arterial infusion of cis-diamminedichloroplatinum (CDDP) using this new method. Clinical antitumor effect was evaluated by CT scan, sonography or operation. CR, PR and NC were observed in 3, 3 and 2 patients, respectively. No significant difference in CDDP levels in serum was found between CR plus PR and NC cases. Since this method can be done without laparotomy, more patients may benefits from arterial infusion chemotherapy.

Left ventricular function and muscle mechanics in hypertrophied rabbit heart

Ventricular contractile performance was studied in relation to wall muscle mechanics in isolated rabbit left ventricles during pressure-overloaded hypertrophy. The isovolumic pressure-volume relation of the hypertrophied ventricle (LVH) shifted to the left and upward from the normal control (NC) (P less than 0.001), but calculated wall stress at each normalized circumferential length decreased in LVH. The pressure-ejection rate relation, determined accurately by velocity control technique, could be adequately approximated by a hyperbola. In LVH, the maximum pressure (Po) was larger (154.3 +/- 17.0 mmHg), whereas the maximum ejection rate (Vej max) was smaller (13.7 +/- 4.2 ml/s, P less than 0.001) than those for NC (127.7 +/- 23.3 mmHg and 22.3 +/- 5.7 ml/s, respectively). The pressure-stiffness relation was linear in both groups, but the vertical axis intercept increased, indicating increased resting stiffness in LVH. Ventricular volume stiffness vs. the mean wall stress relationship of LVH shifted upward, whereas the normalized wall muscle stiffness vs. the mean wall stress relationship of LVH showed a smaller slope. Thus the hypertrophied ventricle can maintain its pumping ability at normal or augmented levels with depressed contractile function of the wall muscle.

Force-velocity relation and contractility in striated muscles

For skeletal muscle, the physiological meaning of Hill's hyperbolic force-velocity equation and the factors affecting it, such as the active state, method of velocity measurement and mode of stimulation, have been discussed. After the development of the sliding filament theory, Hill's equation was generalized to all partially activated isometric tensions and the meaning of Hill's dynamic constants was interpreted from the kinetic analysis of the cross-bridge cycle. In cardiac muscle, determination of the precise force-velocity relation was almost impossible, but most difficulties were overcome by tetanizing the cardiac muscle. As a result, the force-velocity properties of cardiac muscle were confirmed to be very similar to those of skeletal muscle. The maximum shortening velocity under no load, v0, was once used as an index of myocardial contractility which is insensitive to muscle length, but it is now believed that at least at shorter lengths, v0 may vary with muscle length and degree of activation. As new approaches, studies on sarcomere dynamics by the laser diffraction method, observation of calcium transient and pressure-velocity measurement in whole ventricle have been introduced.

Modeling of cardiac muscle contraction based on the cross-bridge mechanism

A mathematical model was developed for the cardiac muscle contraction, assuming that the attachment and detachment cycle of the cross-bridge is activated by the internal calcium concentration and the rate constant of the cycle depends on the sliding velocity of myofilaments. The inputs of the model are the rates of calcium release and uptake, while the output is the tension curve of the muscle. The variables are factored into a series of realizable functions and most constants were determined from the dynamic constants for the tetanic contraction of frog ventricular muscle at 20 degrees C. Using this model, the calcium transient curve as well as the change in the number of cross-bridges in each state of the cycle during a given experimental twitch tension curve was calculated with a PDP 11/60 computer, by selecting the input parameters so that the output curve fit the experimental curve. When the twitch tension was increased by increasing initial muscle length, the rate of calcium release increased and that of uptake decreased. At higher external calcium concentrations, the similar changes in the input parameters were observed. In the presence of 5 X 10(-6) g/ml adrenaline the duration of activation was markedly prolonged, while the rates of calcium release and uptake show little change.

The pressure-volume and stiffness-pressure relations in the isolated rabbit left ventricle

A balloon was introduced into the isolated rabbit left ventricle with intraventricular volume being controlled by a feedback amplifier. Pressure-volume and stiffness-pressure relations were determined as intraventricular volume was changed. These ventricular relations were explained according to the theory of wall muscle mechanics.

Force-velocity relation for the tetanic contraction of frog atrial muscle

The hyperbolic force-velocity relation was obtained by afterload method for the tetanic contraction of frog atrial muscle. The dynamic constants (a/Fm and b), the maximum velocity and especially the maximum tension were considerably smaller than those of ventricular muscle.

Ca binding of isolated cardiac nexus membranes related to intercellular uncoupling

Nexus membranes were isolated from cardiac muscles of guinea pig or ox. It was confirmed by autoradiography that Ca2+ was actually bound with the nexus, and by atomic absorption spectroscopy that bound Ca increased extensively at [Ca2+] higher than 10(-6) to 10(-5) M and showed the dose-response relationship against [Ca2+].