[Endoscopic closure of an esophago-pleural fistula resulting from a perforated esophageal ulcer due to systemic sclerosis:filling and shielding using polyglycolic acid sheets and fibrin glue]

A woman in her 70s with systemic sclerosis experienced dyspnea, and consequently, she was diagnosed with an esophago-pleural fistula, which was caused by a perforated esophageal ulcer. We administered conservative treatments including continuous pleural drainage and total parenteral nutrition. The fistula was closed but recurred, at which point we attempted to close the fistula by filling and shielding using polyglycolic acid (PGA) sheets and fibrin glue (FG). We were able to safely and smoothly fill and shield the fistula using the PGA sheets with a guidewire. We show that endoscopic closure of an esophago-pleural fistula using this technique is an effective, low-invasive treatment for gastrointestinal perforation and refractory fistulas.

A box-shaped shielding device for reducing the risk of COVID-19 droplet infection during gastrointestinal endoscopic procedures

BACKGROUND AND AIMS

Endoscopists and endoscopic assistants are easily exposed to germs, including COVID-19, during aerosol-generating procedures such as gastrointestinal endoscopy. This retrospective study investigated the utility of a box-shaped shielding device for reducing the risk of COVID-19 droplet infection during endoscopic procedures.

METHODS

We created a cuboid box (500 × 650 × 450 mm) with four sides were covered with a transparent, vinyl-chloride sheet having two windows for endoscopic passage and assistance. The shielding box was then placed over a patient's head and shoulders and covered with another transparent vinyl sheet. We assessed its utility and safety using the medical data concerning the procedure time and vital signs and a questionnaire for the endoscopic staff and patients.

RESULTS

We performed endoscopic retrograde cholangiopancreatography-related procedures using this device for two patients suspected of having COVID-19-associated pneumonia. Both patients were smoothly and successfully treated without any complications. No difficulties were noted with either endoscopic operation or in assisting the procedure, and the transparency was good enough to observe the patients' faces and movements.

CONCLUSIONS

This box-shaped shielding device can be used to reduce the risk of COVID-19 droplet infection during endoscopic procedures in the clinical setting.

RELEVANCE FOR PATIENTS

The COVID-19 outbreak has reminded healthcare personnel working in endoscopy units of the importance of infection prevention during endoscopy. The box-shaped shielding device can help endoscopic staff avoid hospital-setting COVID-19 infection.

Filling of Polyglycolic Acid Sheets for Closure of Gastrointestinal Fistulas With an Easily Deliverable Technique Using a Guidewire

Background

This retrospective study aimed to investigate the suitable indications, methodology and long-term effect of the closure of gastrointestinal (GI) fistulas using polyglycolic acid (PGA) sheets and fibrin glue (FG) and to evaluate the usefulness of a delivery technique using a guidewire.

Methods

It involved 10 applications in six patients (median age 73 (range 53 - 78) years old, three men) with GI fistulas. A guidewire was introduced endoscopically or percutaneously into the fistula beyond the opposite orifice of the fistula with radiologic control. A tapered catheter was inserted over the guidewire, and the fistula was cleaned with an adequate quantity of saline. Subsequently, a small piece of PGA sheet was skewered onto the guidewire at the center and then pushed using the tapered catheter over the guidewire and delivered into the fistula. In cases of endoscopic procedure, the mucosa around the fistula was ablated, and the orifice of the fistula along with the surrounding mucosa was shielded with a piece of PGA sheet fixed with hemoclips and FG.

Results

Technical success of fistula closure was achieved in all applications, and no complications were observed after the procedure. The long-term occlusion of the fistula was ultimately achieved in four of six patients at 202 - 654 days (median duration, 244 days) after the last procedure with one or two applications.

Conclusions

The closure of GI fistulas using PGA sheets and FG demonstrated long-term efficacy for upper GI fistula of a certain length, and the filling technique using a guidewire ensured a safe smooth procedure.

IgG4-related Autoimmune Hepatitis with a Suspected Drug-induced Etiology

A 69-year-old man was referred to our department with acute hepatitis. He had been newly treated with benidipine hydrochloride for two months. His blood test results were as follows: aspartate aminotransferase, 1,614 IU/L; alanine aminotransferase, 1,091 IU/L and anti-smooth muscle antibody, ×80. Needle liver biopsy specimen showed interface hepatitis with mainly lymphocytic infiltration and bridging fibrosis in the periportal area. Immunohistochemistry revealed lymphocytic infiltration positive for IgG4. We diagnosed him with IgG4-related AIH with an etiology that was suspected of being drug-induced. Oral prednisolone was started and then tapered after achieving biochemical remission. Hepatitis recurred after the cessation of steroids; however, remission was achieved with ursodeoxycholic acid.

A rare case of Goodpasture syndrome concomitant with bleeding jejunal Dieulafoy's lesion

An 81-year-old man was diagnosed with Goodpasture syndrome (GS) because he met the criteria of positive anti-GBM antibodies, rapid progressive glomerulonephritis and pulmonary hemorrhage. After starting plasmapheresis and steroid pulse therapy, he experienced tarry stool and contrast-enhanced CT revealed an aneurysmal finding in the jejunum. Paroral enteroscopy showed a jejunal Dieulafoy's lesion (DL) with gush-out hemorrhage. Hemostasis was successfully achieved by hemoclipping, and he then experienced no re-bleeding events. GS can present as a jejunal DL, and contrast-enhanced CT is useful for investigating the etiology and site of small intestinal bleeding, which can lead to smooth, effective endoscopic hemostasis.

Endoscopic Gastrojejunostomy for Superior Mesenteric Artery Syndrome Using Magnetic Compression Anastomosis

An 89-year-old woman who was bedridden suffered repeated vomiting due to superior mesenteric artery syndrome (SMAS). We performed gastrojejunostomy via the magnetic compression anastomosis (MCA) technique because her situation was not improved by conservative therapy and because the operative risk was high. We prepared two neodymium magnets: a flat plate-shaped magnet (15 × 3 mm) and a ring-shaped magnet of the same size. The ring-shaped magnet which passed through a guidewire was pushed to the duodenum by an endoscope over the guidewire. The duodenal stricture was balloon-dilated in front of the magnet, and the magnet was pushed all together beyond the stricture and placed at the duodenojejunal junction. Subsequently, the flat plate-shaped magnet was delivered endoscopically to the stomach using a biopsy forceps. The magnets were attracted towards each other transmurally after one more flat plate-shaped magnet was added to the gastric-side magnet. Completion of gastrojejunostomy was confirmed while retrieving the magnets 10 days after starting compression. She has been asymptomatic for 1 month since anastomosis. Endoscopic gastrojejunostomy using MCA was an effective, low-invasive treatment for SMAS.

Experience of Endoscopic Jejunojejunostomy for Anastomotic Obstruction After Subtotal Gastrectomy Using Magnetic Compression Anastomosis

Magnetic compression anastomosis (MCA) was developed as a low-invasive treatment for gastro-enteric or entero-enteric obstruction. A 72-year-old man underwent subtotal gastrectomy with Billroth II reconstruction for early gastric cancer. After the operation, he suffered from repeated aspiration pneumonia due to anastomotic obstruction caused by jejunal kinking at the efferent loop of anastomosis. We therefore performed jejunojejunostomy via the MCA technique, as his situation was not improved despite conservative therapy and he had a high reoperative risk. We prepared two flat plate-shaped neodymium magnets (15 × 3 mm) each with a small hole, and a nylon thread was passed through each hole. Each magnet was then delivered endoscopically to the anal side of the jejunal kinking, subsequently to the anastomosis, using biopsy forceps. The two magnets immediately became attracted towards each other transmurally. Oozing hemorrhage with clot at the mated magnets was observed 10 days after starting the compression. After retrieving the magnets, we confirmed the completion of jejunojejunostomy and then successfully achieved hemostasis of the anastomotic hemorrhage using argon plasma coagulation. The widely patent anastomosis was confirmed endoscopically 1 month after canalization; and he has been asymptomatic and able to eat a normal diet ever since. Endoscopic MCA is an effective, low-invasive treatment for anastomotic obstruction after subtotal gastrectomy. A standardized, safer procedure should be established for general use in the clinical setting.

Prophylactic Biliary Stenting Before Cholecystectomy in Patients With Gallstones and Common Bile Duct Stones

Background

The usefulness of prophylactic biliary stenting for patients with common bile duct stones (CBDS) and gallstones (GS) to prevent recurrent biliary events after endoscopic sphincterotomy (EST) and CBDS extraction before elective cholecystectomy remains controversial. The aim of this study was to evaluate the risk of recurrent CBDS around the perioperative period and clarify its risk factors.

Methods

The clinical data of all patients who received prophylactic biliary stenting after EST for CBDS and later underwent cholecystectomy for GS followed by stent extraction in our institution were retrospectively reviewed. The numbers of residual CBDS at the end first and second endoscopic retrograde cholangiography (ERC) studies were compared. Univariate and multivariate analyses were performed using a logistic regression model to determine risk factors for recurrent CBDS in the perioperative period.

Results

Forty-two consecutive patients received prophylactic biliary stenting and subsequent cholecystectomy for GS. Three of these patients were excluded from this study because the number of residual stones was not confirmed. The median maximum CBDS diameter at second ERC was 0 mm (range, 0 - 10 mm); six patients had multiple CBDS (≥ 5). The number of CBDS at second ERC was increased in comparison to that at the first ERC in 15 patients (38.4%), and was unchanged or decreased in 24 patients. The median minimum cystic duct diameter was 4 mm (range, 1 - 8 mm). The median interval between first ERC and operation was 26 days (range, 2 - 131 days). The median interval between operation and second ERC was 41 days (range, 26 - 96 days). Laparoscopic cholecystectomy (LC) was performed in 38 patients, one of whom was converted from LC to open cholecystectomy. Postoperative complications (transient bacteremia) occurred in one patient. The cystic duct diameter was an independent risk factor for an increased number of CBDS at second ERC in the multivariate analysis (odds ratio 0.611 (95% confidence interval (0.398 - 0.939)), P = 0.03).

Conclusion

Recurrent CBDS around the perioperative period of cholecystectomy is not a rare complication after EST and the removal of CBDS with concomitant GS. Prophylactic biliary stenting is considered useful for preventing CBDS-associated complications, especially for patients in whom the cystic duct diameter is larger (≥ 5 mm).

Experience of Manual Compression Hemostasis Under Endoscopic Observation for Acute Hemorrhagic Rectal Ulcer

We experienced two cases in which manual compression hemostasis under endoscopic observation was used in patients with acute hemorrhagic rectal ulcer (AHRU). The patients experienced an episode of massive fresh hematochezia, requiring the blood transfusion. Emergent sigmoidoscopy revealed multiple ulcers with a large protuberant visible vessel or with gush-out hemorrhage on the lower rectum. Endoscopic hemostasis by hemoclips and hypertonic saline-epinephrine injection was attempted; however, mechanical mucosal injury induced by hemoclips and needles caused another gush-out hemorrhage. Thus, the site of bleeding was manually compressed by a forefinger under endoscopic observation. After 5 min, compression hemostasis was achieved, and the postoperative course was uneventful. Manual compression hemostasis under endoscopic observation is useful and worth attempting for AHRU.

A Rare Case of Local Recurrence Following Curative Endoscopic Submucosal Dissection of Intramucosal Differentiated-Type Gastric Cancer

A 78-year-old man underwent endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) (type 0-IIa) in the anterior wall of the antrum. En bloc resection was achieved. The histopathological examination revealed very well-differentiated tubular adenocarcinoma (tub1) of 30 × 22 mm in size, confined to the mucosa. No lymphovascular invasion or ulceration was observed, and there was no undifferentiated-type component and the margins were tumor-free. Therefore, this lesion fulfilled the eCuraA criteria. Two years after ESD, esophagogastroduodenoscopy revealed an irregular, slightly-depressed lesion within the post-ESD scar. Tubular adenocarcinoma was suspected based on histopathological examination of a biopsy specimen. The tumor was resected by ESD. A histopathological examination revealed well-differentiated tubular adenocarcinoma (tub1) of 6 × 4 mm in size, confined to the mucosa. No lymphovascular invasion was detected and the margins were tumor-free. These findings indicated a curative resection. Recurrence following a curative ESD of an intramucosal differentiated-type EGC which fulfilled the eCuraA criteria is rare. Careful endoscopic observation using magnifying narrow band imaging (NBI) is needed after ESD, even when curative resection is achieved.

[Subcapsular hepatic hematoma due to vessel injury from the rigid portion of a guidewire during endoscopic retrograde cholangiopancreatography]

A 58-year-old male receiving two types of antithrombotic medication developed acute obstructive suppressive cholangitis due to choledocholithiasis. During the first endoscopic retrograde cholangiopancreatography (ERCP) procedure, we performed biliary plastic stenting. Seven days after this procedure and with continued antithrombotic treatment, we performed ERCP with endoscopic sphincterotomy and stone extraction. Twelve hours after this procedure, the patient suffered transient unconsciousness and progression of anemia. Sixty hours after the procedure, he experienced right hypochondralgia and hiccups. Ultrasonography and computed tomography revealed a subcapsular hepatic hematoma. Bleeding was successfully arrested with selective arterial embolization. We suspected that the cause of these problems was vessel injury from the rigid portion of the guidewire during the ERCP procedure.

Endoscopic closure of an anastomo-cutaneous fistula: Filling and shielding using polyglycolic acid sheets and fibrin glue with easily deliverable technique

Background and study aims  Recently, endoscopic closure of gastrointestinal fistulas using polyglycolic acid (PGA) sheets with fibrin glue (FG) has been attempted. A 70-year-old woman who had undergone pancreaticoduodenectomy for pancreatic cancer suffered from a refractory anastomo-cutaneous fistula at the site of gastro-jejunostomy. We attempted endoscopic closure with filling and shielding using PGA sheets and FG. After introducing a guidewire into the fistula, a small piece of PGA sheet was skewered onto the guidewire and then pushed using a tapered catheter over the guidewire and delivered into the fistula. A total of 10 sheets were delivered via the same procedure. Next, the mucosa around the fistula was ablated, and the orifice of the fistula along with the surrounding mucosa was shielded with a piece of PGA sheet fixed with hemoclips and FG. After this procedure, the leakage disappeared and the fistula was undetectable on contrast radiograms. Endoscopic closure of anastomo-cutaneous fistula with filling and shielding using PGA sheets and FG is an effective, safe, low-invasive treatment, and the filling technique using a guidewire ensures a safe, smooth procedure.

[Screening for colorectal cancer using immunological fecal occult blood test in inpatients]

We investigated the usefulness of screening for colorectal cancer (CRC) using immunological fecal occult blood test (FOBT) in 472 scheduled inpatients (median age, 68.6 years) who underwent screening for CRC via FOBT (single stool sample) at our hospital. The recall rate for further examination was 26.6% (126/472), and the rate of patients who underwent further examination was only 34.9% (44/126). The overall colorectal neoplasm detection rate, overall CRC detection rate, and positive predictive value for CRC in inpatients were 5.5% (26/472), 1.4% (7/472), and 5.5% (7/126), respectively, which were higher than those of population-based screening for CRC. Screening for CRC using FOBT in inpatients is a non-invasive and efficient method to detect latent CRC.

Intraductal Ultrasonography as a Local Assessment Before Magnetic Compression Anastomosis for Obstructed Choledochojejunostomy

Magnetic compression anastomosis (MCA) has been developed as a non-surgical alternative treatment for biliary obstruction without serious complications. A 70-year-old woman who had undergone pancreaticoduodenectomy with modified Child reconstruction for pancreatic head cancer suffered from obstructed choledochojejunostomy with no recurrent findings 4 months after the operation. Cholangiography using the percutaneous transhepatic cholangiographic drainage (PTCD) and fluoroscopy revealed complete obstruction of the upper common bile duct, and the length of the obstruction was 7 mm. Intraductal ultrasonography (IDUS) showed fibrous heterogenous hyperechoic appearance without fluid collection, vessels or foreign bodies at the site of the obstruction. We performed choledochojejunostomy using the MCA technique. One magnet was inserted into the obstruction of the hepatic side through the PTCD fistula. Another was delivered endoscopically to the obstruction of the jejunal side. The two magnets were immediately attracted towards each other transmurally, and reanastomosis was confirmed 7 days after starting the compression. The magnets were easily retrieved endoscopically. A 16-Fr indwelling drainage tube was placed in the jejunum through the PTCD. The internal tube is still in place 6 months after reanastomosis, and no MCA-related complications have been observed. In conclusion, MCA is a safe, effective, low-invasive treatment for biliary obstruction, and IDUS is useful for the pretreatment assessment of feasibility and safety.

The LIM-only transcription factor LMO2 determines tumorigenic and angiogenic traits in glioma stem cells

Glioblastomas (GBMs) maintain their cellular heterogeneity with glioma stem cells (GSCs) producing a variety of tumor cell types. Here we interrogated the oncogenic roles of Lim domain only 2 (LMO2) in GBM and GSCs in mice and human. High expression of LMO2 was found in human patient-derived GSCs compared with the differentiated progeny cells. LMO2 is required for GSC proliferation both in vitro and in vivo, as shRNA-mediated LMO2 silencing attenuated tumor growth derived from human GSCs. Further, LMO2 is sufficient to induce stem cell characteristics (stemness) in mouse premalignant astrocytes, as forced LMO2 expression facilitated in vitro and in vivo growth of astrocytes derived from Ink4a/Arf null mice and acquisition of GSC phenotypes. A subset of mouse and human GSCs converted into vascular endothelial-like tumor cells both in vitro and in vivo, which phenotype was attenuated by LMO2 silencing and promoted by LMO2 overexpression. Mechanistically, the action of LMO2 for induction of glioma stemness is mediated by transcriptional regulation of Jagged1 resulting in activation of the Notch pathway, whereas LMO2 directly occupies the promoter regions of the VE-cadherin gene for a gain of endothelial cellular phenotype. Subsequently, selective ablation of human GSC-derived VE-cadherin-expressing cells attenuated vascular formation in mouse intracranial tumors, thereby significantly prolonging mouse survival. Clinically, LMO2 expression was elevated in GBM tissues and inversely correlated with prognosis of GBM patients. Taken together, our findings describe novel dual roles of LMO2 to induce tumorigenesis and angiogenesis, and provide potential therapeutic targets in GBMs.

Distinct iron architecture in SF3B1-mutant myelodysplastic syndrome patients is linked to an SLC25A37 splice variant with a retained intron

Perturbation in iron homeostasis is a hallmark of some hematologic diseases. Abnormal sideroblasts with accumulation of iron in the mitochondria are named ring sideroblasts (RS). RS is a cardinal feature of refractory anemia with RS (RARS) and RARS with marked thrombocytosis (RARS/-T). Mutations in SF3B1, a member of the RNA splicing machinery are frequent in RARS/-T and defects of this gene were linked to RS formation. Here we showcase the differences in iron architecture of SF3B1-mutant and wild-type (WT) RARS/-T and provide new mechanistic insights by which SF3B1 mutations lead to differences in iron. We found higher iron levels in SF3B1 mutant vs WT RARS/-T by transmission electron microscopy/spectroscopy/flow cytometry. SF3B1 mutations led to increased iron without changing the valence as shown by the presence of Fe(2+) in mutant and WT. Reactive oxygen species and DNA damage were not increased in SF3B1-mutant patients. RNA-sequencing and Reverse transcriptase PCR showed higher expression of a specific isoform of SLC25A37 in SF3B1-mutant patients, a crucial importer of Fe(2+) into the mitochondria. Our studies suggest that SF3B1 mutations contribute to cellular iron overload in RARS/-T by deregulating SLC25A37.

Development of high-speed polarizing imaging system for operation in high pulsed magnetic field

A high-speed polarizing microscope system combined with a 37 T pulse magnet has been developed. This system was applied to successfully visualize the field-induced collapse of charge-orbital ordering in a layered manganite La(1/2)Sr(3/2)MnO(4). Quantitative analyses of the obtained polarizing microscope images provided clear evidence of this transition in contrast to rather moderate changes in magnetization and magnetoresistance. The ability of this system to carry out quantitative analysis was further tested through the observation of Faraday rotation in a Tb(3)Ga(5)O(12) crystal. The Verdet constant determined from the polarizing images is in reasonable agreement with that in literature. Local intensity analyses of the images indicate that we can investigate magneto-optical signals within an accuracy of 0.85% in an area of 9.6 x 9.6 microm(2).

Vitamins K2, K3 and K5 exert in vivo antitumor effects on hepatocellular carcinoma by regulating the expression of G1 phase-related cell cycle molecules

A number of studies have shown that various vitamins K, specifically vitamin K2, possessed antitumor activity on various types of rodent- and human-derived neoplastic cell lines. However, there are only a small number of reports demonstrating in vivo antitumor effects of vitamins K. Furthermore, the mechanism of antitumor effects of vitamins K still remains to be examined. In the present study, we examined the antitumor effects of vitamins K2, K3 and K5 on PLC/PRF/5 human hepatocellular carcinoma (HCC) cells in vivo. Furthermore, to examine the mechanism of antitumor actions of these vitamins K, mRNA expression levels of various G1 phase-related cell cycle molecules were evaluated by using a real-time reverse transcription-polymerase chain reaction (RT-PCR) method. HCC-bearing animals were produced by implanting PLC/PRF/5 cells subcutaneously into athymic nude mice, and drinking water containing vitamin K2, K3 or K5 was given to the animals. Treatments with vitamins K2, K3 and K5 were shown to markedly inhibit the growth of HCC tumors. To examine the mechanism of in vivo antitumor effects of vitamins K, total RNA was extracted from HCC tumors, and the expression of G1 phase-related cell cycle molecules was quantitatively examined. Real-time RT-PCR demonstrated that the expression of the cell cycle-driving molecule, cyclin-dependent kinase 4 (Cdk4), in HCC was significantly reduced by the treatments with vitamin K2, K3 and K5. Conversely, the expression of the cell cycle-suppressing molecules, Cdk inhibitor p16INK4a and retinoblastoma, in HCC was significantly enhanced by the treatments with vitamins K2, K3 and K5. These results indicate that vitamins K2, K3 and K5 exert antitumor effects on HCC by regulating the expression of G1 phase-related cell cycle molecules. These results also indicate that vitamins K2, K3 and K5 may be useful agents for the treatment of patients with HCC.

In vitro and in vivo antitumor effects of vitamin K5 on hepatocellular carcinoma

Although a number of studies have shown that vitamins K1, K2 and K3 exerted antitumor effects on various types of rodent- and human-derived neoplastic cell lines, it has not been examined whether or not vitamin K5 also possesses antitumor activity. In the present study, we examined the antitumor effects of vitamin K5 on PLC/PRF/5 human hepatocellular carcinoma (HCC) cells in vitro and in vivo. Furthermore, we examined the mechanisms of antitumor actions of vitamin K5 not only in vitro but also in vivo. Vitamin K5 was shown to suppress the proliferation of PLC/PRF/5 cells at a concentration of 30 microM. By a flow cytometric analysis, it was shown that although vitamin K5 did not induce apoptosis on PLC/PRF/5 cells, it did induce G1 arrest on PLC/PRF/5 cells. Subsequent in vivo study using subcutaneous HCC-bearing athymic nude mice demonstrated that vitamin K5 markedly suppressed the growth of HCC tumors. Although protein expression levels of cyclin D1 and p16INK4a cyclin-dependent kinase (Cdk) inhibitor in HCC tumors were not decreased by vitamin K5 treatment, those of Cdk4 were reduced significantly by the treatment. Taken collectively, vitamin K5 could induce potent antitumor effects on HCC not only in vitro but also in vivo, at least in part by inducing G1 arrest of cell cycle through downregulation of Cdk4 expression. The results demonstrated here indicate that vitamin K5 may be a useful agent for the treatment of patients with HCC.

Antitumor effects of vitamins K1, K2 and K3 on hepatocellular carcinoma in vitro and in vivo

A number of studies have shown that various K vitamins, specifically vitamins K2 and K3, possess antitumor activity on various types of rodent- and human-derived neoplastic cell lines. In the present study, we examined the antitumor effects of vitamins K1, K2 and K3 on PLC/PRF/5 human hepatocellular carcinoma (HCC) cells in vitro and in vivo. Furthermore, we examined the mechanisms of antitumor actions of these vitamins in vitro and in vivo. Although vitamin K1 did not inhibit proliferation of PLC/PRF/5 cells at a 90-microM concentration (the highest tested), vitamins K2 and K3 suppressed proliferation of the cells at concentrations of 90 and 9 microM, respectively. By flow cytometric analysis, it was shown that not only vitamin K1, but also vitamin K2 did not induce apoptosis or cell cycle arrest on PLC/PRF/5 cells. In contrast, vitamin K3 induced G1 arrest, but not apoptosis on PLC/PRF/5 cells. Subsequent in vivo study using subcutaneous HCC-bearing athymic nude mice demonstrated that both vitamins K2 and K3 markedly suppressed the growth of HCC tumors to similar extent. Protein expression of cyclin D1 and cyclin-dependent kinase 4 (Cdk4), but not p16INK4a Cdk inhibitor in the tumor was significantly reduced by vitamin K2 or K3 treatment, indicating that vitamins K2 and K3 may induce G1 arrest of cell cycle on PLC/PRF/5 cells in vivo. Taken collectively, vitamins K2 and K3 were able to induce potent antitumor effects on HCC in vitro and in vivo, at least in part, by inducing G1 arrest of the cell cycle. The results indicate that vitamins K2 and K3 may be useful agents for the treatment of patients with HCC.

Proliferative capability of hepatocytes and expression of G1-related cell cycle molecules in the development of liver cirrhosis in rats

Liver cirrhosis is the end stage of various chronic liver diseases and its prognosis is very poor. One of the most important causes of liver cirrhosis appears to be impaired proliferative capability of hepatocytes caused by continuous hepatic damage. Cell cycle-related molecules have been shown to play essential roles in cell proliferation. Specifically, G1-related cell cycle molecules are important, because they are requisite for the entry into the cell cycle from the quiescent state. However, the role of these cell cycle molecules during the development of liver cirrhosis remains to be examined. In the present study, liver cirrhosis was produced in rats by intraperitoneally administering dimethylnitrosamine (DMN). Proliferative capability of hepatocytes estimated immunohistochemically by proliferating cell nuclear antigen staining was markedly increased at an early stage of cirrhosis development. However, it was gradually decreased thereafter and suppressed substantially at the time of cirrhosis manifestation. Cyclin D1 expression estimated by a real-time reverse transcription-polymerase chain reaction (RT-PCR) method was also increased markedly at an early stage of cirrhosis development but decreased substantially thereafter. mRNA levels of catalytic subunits of cyclin D1, cyclin-dependent kinase 4 (Cdk4) and Cdk6, did not show significant changes during the development of liver cirrhosis. Among G1-specific Cdk inhibitors, expression of p15INK4b and p16INK4a estimated by an RT-PCR method was increased according to the progression of cirrhosis and reached a peak at the time of cirrhosis manifestation. Conversely, p18INK4c expression did not change significantly during the development of liver cirrhosis. These results suggest that cyclin D1 plays an essential role in hepatocyte proliferation in response to hepatic damage. However, with the decrease of cyclin D1 expression and increase of p15INK4b and p16INK4a expression, proliferative capability of hepatocytes is severely impaired and extracellular matrix components are deposited to retrieve space lost by the destruction of hepatic parenchyma, resulting in establishment of liver cirrhosis.

Ras-dependent cell cycle commitment during G2 phase

Synchronization used to study cell cycle progression may change the characteristics of rapidly proliferating cells. By combining time-lapse, quantitative fluorescent microscopy and microinjection, we have established a method to analyze the cell cycle progression of individual cells without synchronization. This new approach revealed that rapidly growing NIH3T3 cells make a Ras-dependent commitment for completion of the next cell cycle while they are in G2 phase of the preceding cell cycle. Thus, Ras activity during G2 phase induces cyclin D1 expression. This expression continues through the next G1 phase even in the absence of Ras activity, and drives cells into S phase.

The p38 pathway provides negative feedback for Ras proliferative signaling

Ras activates three mitogen-activated protein kinases (MAPKs) including ERK, JNK, and p38. Whereas the essential roles of ERK and JNK in Ras signaling has been established, the contribution of p38 remains unclear. Here we demonstrate that the p38 pathway functions as a negative regulator of Ras proliferative signaling via a feedback mechanism. Oncogenic Ras activated p38 and two p38-activated protein kinases, MAPK-activated protein kinase 2 (MK2) and p38-related/activated protein kinase (PRAK). MK2 and PRAK in turn suppressed Ras-induced gene expression and cell proliferation, whereas two mutant PRAKs, unresponsive to Ras, had little effect. Moreover, the constitutive p38 activator MKK6 also suppressed Ras activity in a p38-dependent manner whereas arsenite, a potent chemical inducer of p38, inhibited proliferation only in a tumor cell line that required Ras activity. MEK was required for Ras stimulation of the p38 pathway. The p38 pathway inhibited Ras activity by blocking activation of JNK, without effect upon ERK, as evidenced by the fact that PRAK-mediated suppression of Ras-induced cell proliferation was reversed by coexpression of JNKK2 or JNK1. These studies thus establish a negative feedback mechanism by which Ras proliferative activity is regulated via signaling integrations of MAPK pathways.

Influence of cell cycle and oncogene activity upon topoisomerase IIalpha expression and drug toxicity

The cell cycle, oncogenic signaling, and topoisomerase (topo) IIalpha levels all influence sensitivity to anti-topo II drugs. Because the cell cycle and oncogenic signaling influence each other as well as topo IIalpha levels, it is difficult to assess the importance of any one of these factors independently of the others during drug treatment. Such information, however, is vital to an understanding of the cellular basis of drug toxicity. We, therefore, developed a series of analytical procedures to individually assess the role of each of these factors during treatment with the anti-topo II drug etoposide. All studies were performed with asynchronously proliferating cultures by the use of time-lapse and quantitative fluorescence staining procedures. To our surprise, we found that neither oncogene action nor the cell cycle altered topo IIalpha protein levels in actively cycling cells. Only a minor population of slowly cycling cells within these cultures responded to constitutively active oncogenes by elevating topo IIalpha production. Thus, it was possible to study the effects of the cell cycle and oncogene action on drug-treated cells while topo IIalpha levels remained constant. Toxicity analyses were performed with two consecutive time-lapse observations separated by a brief drug treatment. The cell cycle phase was determined from the first observation, and cell fate was determined from the second. Cells were most sensitive to drug treatment from mid-S phase through G(2) phase, with G(1) phase cells nearly threefold less sensitive. In addition, the presence of an oncogenic src gene or microinjected Ras protein increased drug toxicity by approximately threefold in actively cycling cells and by at least this level in the small population of slowly cycling cells. We conclude that both cell cycle phase and oncogenic signaling influence drug toxicity independently of alterations in topo IIalpha levels.

Characteristics of Cyclodextrin Adsorption onto Activated Carbons

Whereas the amount of cyclodextrin (CD) adsorbed onto the large-pore activated carbon A (AC-A) increased with the number of glucose units, the amount adsorbed onto the small-pore activated carbon B (AC-B) showed the opposite tendency. This behavior can be accounted for in terms of a molecular exclusion. It is known that a good linear relationship is obtained between the Freundlich constants log K and 1/N for hydrophobic adsorption. The adsorption of CDs onto AC-A obeyed this relation, but, because of the molecular exclusion, the plots of AC-B deviated greatly. The adsorption of CDs onto AC-A was not explainable in terms of solubility. This could be because, in the case of a solid compound, adsorbability depends on the chemical potential of the molecule in aqueous solution whereas solubility depends also on the heat of fusion of the solid. In order to estimate the relative chemical potential of CDs in water, a method based on the numbers of carbon atoms and oxygen atoms in the molecule was devised which allowed a more accurate estimation of CD adsorbability than did solubility. The mean pore diameter of AC-A increased after CD adsorption, while that of AC-B showed little change. Copyright 2000 Academic Press.

[Serum leptin levels in normal pregnant women and their babies]

OBJECTIVE

To investigate serum leptin levels in normal pregnant women and their babies.

METHODS

Immunoradioassay was used to measure the serum levels of leptin in 10 non-pregnant women, 63 pregnant women (31 in the firs, 10 in the second, and 22 in the third trimester), 27 women at delivery, 18 women in the first week after delivery and in 18 newborns' cord serum. Serum leptin levels were correlated with body weight, body mass index (BMI), fasting insulin levels and lipids.

RESULTS

Serum insulin, cholesterol, triglyceride were increased since the second trimester during pregnancy. One week after delivery serum insulin but not cholesterol and triglicetride level was decreased to the levels of non-pregnancy. Serum leptin levels were (7.98 +/- 4.42) micrograms/L in non-pregnant women and (7.03 +/- 3.42) micrograms/L in the first trimester. Then the levels were increased to (13.97 +/- 8.03) micrograms/L in second trimester and (14.86 +/- 6.25) micrograms/L in the third trimester, (19.89 +/- 9.66) micrograms/L at the delivery time and returned to (10.86 +/- 9.18) micrograms/L in the first week after delivery, respectively. Cord serum leptin levels of newborns were (8.93 +/- 6.95) micrograms/L. Serum leptin levels in pregnant women were positively correlated with their body weight, BMI, fasting serum insulin and glycerol levels. Cord serum leptin levels was positively correlated with newborn birth weights as well as their insulin levels.

CONCLUSIONS

(1) Serum leptin levels increase in the second and third trimester, and may contribute to the inhibition of increased food intake, body weight and body fat. (2) Newborn serum leptin may come from themselves, and the levels were lower than those in their mothers. (3) Birth weight, possibly adiposity, as well as serum insulin positively regulates serum leptin levels in neonates as in adults.

An unexpected link between the secretory path and the organization of the nucleus

Yeast sec mutations define the machinery of vesicular traffic. Surprisingly, many of these mutations also inhibit ribosome biogenesis by reducing transcription of rRNA and genes encoding ribosomal proteins. We observe that these mutants reversibly inhibit protein import into the nucleus, with import cargo accumulating at the nucleoplasmic face of nuclear pore complexes, as when Ran-GTP cannot bind importins. They also rapidly and reversibly relocate multiple nucleolar and nucleoplasmic proteins to the cytoplasm. The import block and relocation are antagonized by overexpression of yeast Ran, Hog1p kinase, or Ssa/Hsp70 proteins or by inhibition of protein synthesis. These nucleocytoplasmic signaling events document an extraordinary plasticity of nuclear organization.

Cyclin D1 production in cycling cells depends on ras in a cell-cycle-specific manner

BACKGROUND

Cellular Ras and cyclin D1 are required at similar times of the cell cycle in quiescent NIH3T3 cells that have been induced to proliferate, but not in the case of cycling NIH3T3 cells. In asynchronous cultures, Ras activity has been found to be required only during G2 phase to promote passage through the entire upcoming cell cycle, whereas cyclin D1 is required through G1 phase until DNA synthesis begins. To explain these results in molecular terms, we propose a model whereby continuous cell cycle progression in NIH3T3 cells requires cellular Ras activity to promote the synthesis of cyclin D1 during G2 phase. Cyclin D1 expression then continues through G1 phase independently of Ras activity, and drives the G1-S phase transition.

RESULTS

We found high levels of cyclin D1 expression during the G2, M and G1 phases of the cell cycle in cycling NIH3T3 cells, using quantitative fluorescent antibody measurements of individual cells. By microinjecting anti-Ras antibody, we found that the induction of cyclin D1 expression beginning in G2 phase was dependent on Ras activity. Consistent with our model, cyclin D1 expression during G1 phase was particularly stable following neutralization of cellular Ras. Finally, ectopic expression of cyclin D1 largely overcame the requirement for cellular Ras activity during the continuous proliferation of cycling NIH3T3 cells.

CONCLUSIONS

Ras-dependent induction of cyclin D1 expression beginning in G2 phase is critical for continuous cell cycle progression in NIH3T3 cells.

Cell cycle arrest and morphological alterations following microinjection of NIH3T3 cells with Pur alpha

Levels of Pur alpha, a protein implicated in control of both DNA replication and gene transcription, fluctuate during the cell cycle, being lowest in early S phase and highest just after mitosis. Here we have employed a new video time-lapse technique enabling us to determine the cell cycle position of each cell in an asynchronous culture at a given time and to ask whether introduction of Pur alpha protein at specific times can affect cell cycle progression. Approximately 80% of all NIH3T3 cells injected with Pur alpha were inhibited from passing through mitosis. Cells injected with Pur alpha during S or G2 phases were efficiently blocked with a 4N (G2 phase) DNA level, as determined by quantitative DNA photometry of individual cells. Of the cells injected with Pur alpha during G1 phase, 40% experienced a rapid cell death characterized by extreme cellular fragmentation. Of those G1 injected cells which remained viable, approximately equal numbers were arrested with either 2N or 4N DNA levels. Cells arrested by Pur alpha in G2 phase grew to cover a large surface area. These results link fluctuations in Pur alpha levels to aspects of cell cycle control.

Cellular ras and cyclin D1 are required during different cell cycle periods in cycling NIH 3T3 cells

Novel techniques were used to determine when in the cell cycle of proliferating NIH 3T3 cells cellular Ras and cyclin D1 are required. For comparison, in quiescent cells, all four of the inhibitors of cell cycle progression tested (anti-Ras, anti-cyclin D1, serum removal, and cycloheximide) became ineffective at essentially the same point in G1 phase, approximately 4 h prior to the beginning of DNA synthesis. To extend these studies to cycling cells, a time-lapse approach was used to determine the approximate cell cycle position of individual cells in an asynchronous culture at the time of inhibitor treatment and then to determine the effects of the inhibitor upon recipient cells. With this approach, anti-Ras antibody efficiently inhibited entry into S phase only when introduced into cells prior to the preceding mitosis, several hours before the beginning of S phase. Anti-cyclin D1, on the other hand, was an efficient inhibitor when introduced up until just before the initiation of DNA synthesis. Cycloheximide treatment, like anti-cyclin D1 microinjection, was inhibitory throughout G1 phase (which lasts a total of 4 to 5 h in these cells). Finally, serum removal blocked entry into S phase only during the first hour following mitosis. Kinetic analysis and a novel dual-labeling technique were used to confirm the differences in cell cycle requirements for Ras, cyclin D1, and cycloheximide. These studies demonstrate a fundamental difference in mitogenic signal transduction between quiescent and cycling NIH 3T3 cells and reveal a sequence of signaling events required for cell cycle progression in proliferating NIH 3T3 cells.

Dissociation of CDK2 from cyclin A in response to the topoisomerase II inhibitor etoposide in v-src-transformed but not normal NIH 3T3 cells

Our previous work has demonstrated that treatment of NIH 3T3 cells with etoposide (VP16), an inhibitor of DNA topoisomerase II and widely used anticancer agent, results in G2/M-phase arrest, whereas treatment of cells transformed by v-src, v-ras, or v-raf results in an S-phase blockage. The present studies describe the mechanistic aspects of this selective S-phase arrest in the v-src-transformed cells. The S-phase arrest in these cells was found to be coupled with depletion of cyclin A-dependent kinase activity. This decrease could not be explained by changes in the overall level of cyclin A, CDK2, p27, or p21 proteins. Rather, it was associated with a time-dependent reduction of CDK2 protein complexed with cyclin A following VP16 treatment. It was further shown that the decrease of cyclin A-associated CDK2 was linked to an increase of CDK2 protein in cyclin E immunocomplexes, which suggests that CDK2 might become redistributed following treatment with VP16. Thus, oncogenic transformation by v-src can trigger separation of CDK2 protein from cyclin A in response to VP16. This might contribute to the depletion of cyclin A-dependent kinase activity and the selective S-phase arrest by VP16 in v-src-transformed cells.

p21Waf1 inhibits the activity of cyclin dependent kinase 2 by preventing its activating phosphorylation

Prostaglandin A2 (PGA2), a potent inhibitor of the growth of many cell types, inhibits G1 phase cyclin dependent kinases (cdk). Although PGA2 suppresses cyclin D1 and elevates p21Waf1 levels, it was the failure of cdk2 to become activated by phosphorylation which correlated best with growth inhibition. In kinetic studies, cdk2 activation was inhibited efficiently only if p21Waf1 levels increased prior to the activating phosphorylation; suggesting that p21Waf1 had blocked this phosphorylation. This model was confirmed in cells from p21Waf1 knockout mice where PGA2 was completely unable to block the activating phosphorylation of cdk2, or inhibit cdk2 activity. As expected, growth inhibition of p21Waf1(-/-) cells was not observed at PGA2 concentrations which inhibited cdk2 activity and growth of p21Waf1(+/+) cells.

FADD gene therapy for malignant gliomas in vitro and in vivo

Fas/APO-1 (CD95), a cell surface cytokine receptor, triggers apoptotic cell death by specific agonist antibody, suggesting that Fas/APO-1 may be a promising target for treatment of tumors. In this study, we show that treatment with anti-Fas antibody effectively induced apoptosis in malignant glioma cell lines with high expression of Fas/APO-1 (n = 3). Malignant glioma cells with low or undetectable expression of Fas/APO-1 (n = 6), however, were resistant to Fas/APO-1-dependent cytotoxicity. The purpose of this study, therefore, was to determine whether resistant tumors could be made susceptible to apoptosis. FADD/MORT1 constitutes a novel protein that associates specifically with the cytoplasmic death domain of Fas/APO-1 and induces apoptosis. We investigated whether overexpression of FADD would induce apoptosis in malignant glioma cells without activating Fas/APO-1. Results indicated that about 85% of malignant glioma cells, regardless of Fas/APO-1 expression levels, underwent apoptosis after transient transfection with FADD expression vector. To further improve gene transfer of FADD into malignant glioma cells, we constructed a retroviral vector containing the FADD gene. The retroviral transfer of FADD gene significantly enhanced the transduction efficiency and effectively inhibited both in vitro and in vivo survival of malignant glioma cells through induction of apoptosis. These findings suggest that the FADD gene is a novel and useful tool for the treatment of malignant gliomas.

Antisense telomerase treatment: induction of two distinct pathways, apoptosis and differentiation

Telomerase, the enzyme that elongates telomeric DNA (TTAGGG)n, may be involved in cellular immortality and oncogenesis. To investigate the effect of inhibition of telomerase on tumor cells, we transfected the antisense vector against the human telomerase RNA into human malignant glioma cells exhibiting telomerase activity. After 30 doublings, some subpopulations of transfectants expressed a high level of interleukin-1beta-converting enzyme (ICE) protein and underwent apoptosis. In contrast, other subpopulations also showed enhanced ICE protein but escaped from apoptotic crisis and continued to grow, although their DNA synthesis, invasive ability, and tumorigenicity in nude mice were significantly reduced. Surviving cells demonstrated increased expression of glial fibrillary acidic protein and decreased motility, consistent with a more differentiated state. These cells also contained enhanced expression of the cyclin-dependent kinase inhibitors (CDKIs) p21 and p27. Treatment of surviving nonapoptotic cells with antisense oligonucleotides against p27, but not p21, induced apoptotic cell death, suggesting that p27 may have protected differentiating glioma cells from apoptosis. These data show that treatment with antisense telomerase inhibits telomerase activity and subsequently induces either apoptosis or differentiation. Regulation of these two distinct pathways may be dependent on the expression of ICE or CDKIs.

Dbp5p, a cytosolic RNA helicase, is required for poly(A)+ RNA export

The DBP5 gene encodes a putative RNA helicase of unknown function in the yeast Saccharomyces cerevisiae. It is shown here that Dbp5p is an ATP-dependent RNA helicase required for polyadenylated [poly(A)+] RNA export. Surprisingly, Dbp5p is present predominantly, if not exclusively, in the cytoplasm, and is highly enriched around the nuclear envelope. This observation raises the possibility that Dbp5p may play a role in unloading or remodeling messenger RNA particles (mRNPs) upon arrival in the cytoplasm and in coupling mRNP export and translation. The functions of Dbp5p are likely to be conserved, since its potential homologues can be found in a variety of eukaryotic cells.

Retroviral transfer of CPP32beta gene into malignant gliomas in vitro and in vivo

Malignant gliomas are highly aggressive neoplasms that are very resistant to current therapeutic approaches, including irradiation, chemotherapy, and immunotherapy. To improve the prognosis, it is absolutely essential to explore novel modalities of treatment. Recently, we have demonstrated that interleukin 1beta-converting enzyme (ICE), a mammalian homologue of the Caenorhabditis elegans cell death gene ced-3, induces apoptotic cell death in malignant glioma cells. To date, ICE and ICE-like proteases (the ICE family), such as Ich-1L, CPP32beta, Mch2alpha, and Mch3alpha, have been shown to mediate apoptosis in some cells. The purpose of this study is to determine whether the ICE gene family functions as a useful tool for the treatment of malignant glioma cells through induction of apoptosis. The transient transfection assays showed that CPP32beta and Mch2alpha genes induced apoptotic cell death in malignant glioma cells more effectively than did the ICE, Ich-1L, and Mch3alpha genes. To improve the efficiency of gene transfer into malignant glioma cells, we constructed the retroviral vectors containing the ICE gene family. The retroviral transfer of CPP32beta or Mch2alpha gene effectively induced apoptosis in malignant glioma cells in vitro. Furthermore, treatment of tumors grown in mice with retrovirus containing CPP32beta significantly inhibited growth of the tumors through induction of apoptosis. The retroviral transfer of CPP32beta or Mch2alpha, therefore, may be a novel and promising approach for the treatment of malignant glioma, an invariably fatal tumor.

Activation of JNK/SAPK pathway is not directly inhibitory for cell cycle progression in NIH3T3 cells

In this study the induction of stress activated protein kinase (SAPK) activity by protein synthesis inhibitors was shown not to inhibit cellular proliferation. Anisomycin induced strong SAPK activity at non-inhibitory concentrations for either protein or DNA synthesis, while the other two inhibitors, emetine and cycloheximide, blocked cell cycle progression without strong SAPK induction. With all three inhibitors, the induction of SAPK activity was always accompanied by protein synthesis inhibition to some extent. Stimulation of mRNA expression of the genes c-jun, c-fos and c-myc correlated well with SAPK induction, but not with cell cycle inhibition. With concentrations of each inhibitor able to block DNA synthesis, no induction of message for the cyclin dependent kinase inhibitor waf-1 was observed; while induction of gadd45 message indicated that the cells might be responding to growth-arrest or DNA damage. The inability of microinjected E2F/DP1 transcription factor proteins to overcome the inhibition of DNA synthesis induced by protein synthesis inhibitors indicate that blockage of an early event in cell cycle progression had occurred. These results indicate that the SAPK induction by protein synthesis inhibitors has no proliferative consequences.

A yeast acetyl coenzyme A carboxylase mutant links very-long-chain fatty acid synthesis to the structure and function of the nuclear membrane-pore complex

The conditional mRNA transport mutant of Saccharomyces cerevisiae, acc1-7-1 (mtr7-1), displays a unique alteration of the nuclear envelope. Unlike nucleoporin mutants and other RNA transport mutants, the intermembrane space expands, protuberances extend from the inner membrane into the intermembrane space, and vesicles accumulate in the intermembrane space. MTR7 is the same gene as ACC1, encoding acetyl coenzyme A (CoA) carboxylase (Acc1p), the rate-limiting enzyme of de novo fatty acid synthesis. Genetic and biochemical analyses of fatty acid synthesis mutants and acc1-7-1 indicate that the continued synthesis of malonyl-CoA, the enzymatic product of acetyl-CoA carboxylase, is required for an essential pathway which is independent from de novo synthesis of fatty acids. We provide evidence that synthesis of very-long-chain fatty acids (C26 atoms) is inhibited in acc1-7-1, suggesting that very-long-chain fatty acid synthesis is required to maintain a functional nuclear envelope.

A DEAD-box-family protein is required for nucleocytoplasmic transport of yeast mRNA

An enormous variety of primary and secondary mRNA structures are compatible with export from the nucleus to the cytoplasm. Therefore, there seems to be a mechanism for RNA export which is independent of sequence recognition. There nevertheless is likely to be some relatively uniform mechanism which allows transcripts to be packaged as ribonucleoprotein particles, to gain access to the periphery of the nucleus and ultimately to translocate across nuclear pores. To study these events, we and others have generated temperature-sensitive recessive mRNA transport (mtr) mutants of Saccharomyces cerevisiae which accumulate poly(A)+ RNA in the nucleus at 37 degrees C. Several of the corresponding genes have been cloned. Upon depletion of one of these proteins, Mtr4p, conspicuous amounts of nuclear poly(A)+ RNA accumulate in association with the nucleolus. Corresponding dense material is also seen by electron microscopy. MTR4 is essential for growth and encodes a novel nuclear protein with a size of approximately 120 kDa. Mtr4p shares characteristic motifs with DEAD-box RNA helicases and associates with RNA. It therefore may well affect RNA conformation. It shows extensive homology to a human predicted gene product and the yeast antiviral protein Ski2p. Critical residues of Mtr4p, including the mtr4-1 point mutation, have been identified. Mtr4p may serve as a chaperone which translocates or normalizes the structure of mRNAs in preparation for export.