Size effect of fluorescent thiol-organosilica particles on their distribution in the mouse spleen

We investigated the distribution of intravenously administered thiol-organosilica particle (thiol-OS) in the spleen to evaluate their size effect in mice. A single administration of particles of thiol-OS containing rhodamine B (Rh) (90, 280, 340, 450, 630, 1110, 1670, and 3030 nm in diameter) was performed. After 24 h, we conducted a combination analysis using histological studies by fluorescent microscopy and quantitative inductively coupled plasma optical emission spectrometry (ICP-OES), which revealed no clear correlation between the particle size and spleen uptake of particle weight and number per tissue weight, and the injection dose. Moreover, Rh with 450 nm diameter (Rh450) showed the highest uptake, and Rh with 340 nm diameter (Rh340) showed the lowest uptake. Histologically, large fluorescent areas in the marginal zone (MZ) and red pulp (RP) of the spleen were observed for all particle sizes, but less in the follicle of white pulp. Using combination analysis using the particle weights of ICP-OES and the fluorescent area, we compared the distributions of each particle in each region. Rh450 had the largest accumulated weight in the MZ and RP. Particles larger than Rh450 showed negative correlations between their sizes and accumulated weight in the MZ and RP. Simultaneous dual administration of particles using Rhs and thiol-OS containing fluorescein (90 nm in diameter) showed the size-dependent difference in cellular distribution and intracellular localization. Immunohistochemical staining against macrophage markers, CD169, and F4/80 showed various colocalization patterns with macrophages that uptook particles, indicating differences in particle uptake in each macrophage may have novel significance.

Effects of Au States in Thiol-Organosilica Nanoparticles on Enzyme-like Activity for X-ray Sensitizer Application: Focus on Reactive Oxygen Species Generation in Radiotherapy

In radiotherapy, the use of Au nanoparticles (Au NPs) has been proposed to enhance cell damage by X-ray irradiation. Although the role of Au in radiotherapy is not fully understood, the catalytic activity of Au has been actively studied in the industrial field. Moreover, owing to their enzyme-like activity and high biocompatibility in vitro and in vivo, Au NPs present significant potential for biological applications. In this study, we incorporated different Au states both on the surface and embedded in thiol-organosilica (thiol-OS/Au series) to investigate the efficiency of anticancer cell activity of Au in radiotherapy. The thiol-OS/Au series comprised different Au(I)/Au(0) ratios and Au NPs, and different sizes of Au NPs were embedded in thiol-OS/Au. These thiol-OS/Au series samples were evaluated for enzyme-like activities in reactive oxygen species (ROS) generation by X-ray irradiation. Thiol-OS/Au embedded with small Au NPs (AC600/thiol-OS/Au) exhibited peroxidase (POD)-like activity under acidic conditions. This POD-like activity improved ROS generation and cytotoxicity under X-ray irradiation. Furthermore, AC600/thiol-OS/Au exhibited catalase (CAT)-like activity under basic conditions and showed no cytotoxicity toward nonirradiated cells. These results revealed the efficiency of functionalizing with small Au NPs that possess pH-controlled POD- and CAT-like activity as a radiosensitizer. We compared the suitability of using Au with different states to obtain the thiol-OS/Au series samples for application as radiosensitizers. The findings of this study will aid the design of efficacious strategies for the Au nanostructure-based radiotherapy of cancer cells.

Preparation of Fetal Bovine Serum-Copper Phosphate Hybrid Particles under Cell Culture Conditions for Cancer Cell Treatment

Fetal bovine serum (FBS) particles, which mainly consist of bovine serum albumin, have the potential for biological and medical applications as drug carriers. The coacervation of albumin is a common technique for preparing albumin-based particles. The replacement of salt with novel metal salts such as Cu is an affordable way to embed the metal ion in the albumin-based particles. Further, increased Cu distribution is prevalent in many cancers. Here, we prepared adhesive cell-like FBS-copper phosphate hybrid particles [FBS-Cu₃(PO₄)₂], which exhibited toxicity toward cancer cells, with a narrow size distribution under cell culture conditions for preventing tumor progression. FBS-Cu₃(PO₄)₂ showed peroxidase-like activity. In addition, FBS-Cu₃(PO₄)₂ was successfully loaded with rhodamine B and conjugated with fluorescein isothiocyanate as models of drugs by coincubation. Thus, we designed a simple preparation method for optimizing FBS-Cu₃(PO₄)₂ synthesis under cell culture conditions. FBS-Cu₃(PO₄)₂ has significant potential as an efficient reactive oxygen species generator and drug-delivery agent against cancer cells. Furthermore, the RhoB-loaded FBS-Cu₃(PO₄)₂ successfully interacted with 4T1 mouse mammary tumor cells and were confirmed to exhibit toxicity.

Analysis of cell-nanoparticle interactions and imaging of in vitro labeled cells showing barcorded endosomes using fluorescent thiol-organosilica nanoparticles surface-functionalized with polyethyleneimine

Biomedical imaging using cell labeling is an important technique to visualize cell dynamics in the body. To label cells, thiol-organosilica nanoparticles (thiol-OS) containing fluorescein (thiol-OS/Flu) and rhodamine B (thiol-OS/Rho) were surface-functionalized with polyethyleneimine (PEI) (OS/Flu-PEI and OS/Rho-PEI) with 4 molecular weights (MWs). We hypothesized PEI structures such as brush, bent brush, bent lie-down, and coiled types on the surface depending on MWs based on dynamic light scattering and thermal gravimetric analyses. The labeling efficacy of OS/Flu-PEIs was dependent on the PEI MW and the cell type. A dual-particle administration study using thiol-OS and OS-PEIs revealed differential endosomal sorting of the particles depending on the surface of the NPs. The endosomes in the labeled cells using OS/Flu-PEI and thiol-OS/Rho revealed various patterns of fluorescence termed barcoded endosomes. The cells labeled with OS-PEI in vitro were administrated to mice intraperitoneally after in situ labeling of peritoneal cells using thiol-OS/Rho. The in vitro labeled cells were detected and identified in cell aggregates in vivo seamlessly. The labeled cells with barcoded endosomes were also identified in cell aggregates. Biomedical imaging of in vitro OS-PEI-labeled cells combined with in situ labeled cells showed high potential for observation of cell dynamics.

Surface Functionalization of Organosilica Nanoparticles With Au Nanoparticles Inhibits Cell Proliferation and Induces Cell Death in 4T1 Mouse Mammary Tumor Cells for DNA and Mitochondrial-Synergized Damage in Radiotherapy

Radiotherapy is one of the most effective cancer treatments. Au nanoparticles (NPs) are one of the most used X-ray sensitizing materials however the effective small sub-nm size of Au NPs used for X-ray sensitizers is disadvantageous for cellular uptake. Here, we propose the surface functionalization of organosilica NPs (OS) with Au NPs (OS/Au), which combined the 100 nm size of OS and the sub-nm size of Au NPs, and synthesized effective Au materials as an X-ray sensitizer. The X-ray sensitizing potential for 4T1 mouse mammary tumor cells was revealed using a multifaceted evaluation combined with a fluorescence microscopic cell imaging assay. The number of polyethyleneimine (PEI)-modified OS (OS/PEI) and OS/Au (OS/Au/PEI) uptake per 4T1 mouse mammary tumor cell was the same; however, 4T1 cells treated with OS/Au/PEI exhibited significant inhibition of cell proliferation and increases in cell death by X-ray irradiation at 8Gy. The non-apoptotic death of OS/Au/PEI-treated 4T1 cells was increased by DNA and mitochondrial-synergized damage increase and showed potential applications in radiotherapy.

Development of Non-Porous Silica Nanoparticles towards Cancer Photo-Theranostics

Nanoparticles have demonstrated several advantages for biomedical applications, including for the development of multifunctional agents as innovative medicine. Silica nanoparticles hold a special position among the various types of functional nanoparticles, due to their unique structural and functional properties. The recent development of silica nanoparticles has led to a new trend in light-based nanomedicines. The application of light provides many advantages for in vivo imaging and therapy of certain diseases, including cancer. Mesoporous and non-porous silica nanoparticles have high potential for light-based nanomedicine. Each silica nanoparticle has a unique structure, which incorporates various functions to utilize optical properties. Such advantages enable silica nanoparticles to perform powerful and advanced optical imaging, from the in vivo level to the nano and micro levels, using not only visible light but also near-infrared light. Furthermore, applications such as photodynamic therapy, in which a lesion site is specifically irradiated with light to treat it, have also been advancing. Silica nanoparticles have shown the potential to play important roles in the integration of light-based diagnostics and therapeutics, termed "photo-theranostics". Here, we review the recent development and progress of non-porous silica nanoparticles toward cancer "photo-theranostics".

Characterization and Bone Response of Carbonate-Containing Apatite-Coated Titanium Implants Using an Aqueous Spray Coating

We performed thin carbonate-containing apatite (CA) coating on titanium (Ti) by an aqueous spray coating (ASC) method that consisted of a Ca-CO₃-PO₄ complex. Two different CA coatings were produced by two different spray amounts and were heat-treated after spraying. We evaluated three-dimensional structures, adhesiveness to Ti, and durability of the CA film. In addition, we performed immersion experiments in simulated body fluid (SBF), and bone responses were evaluated after implantation into a femoral bone defect in rats. The bonding ability of ASC-coated implant into the bone was examined by push-in tests. Unique network structures with small particles were identified on CA coatings. Although heat treatment produced no significant difference in surface morphology, scratch tests revealed that heat treatment improved the adhesion of CA coatings to Ti. Crystal formation progressed on CA-coated specimens, and the sample placement direction influenced crystal formation and growth in SBF immersion. Animal implantation experiments revealed significantly greater bone-to-implant contact ratio and bone mass in both cortical and bone marrow, respectively, four weeks after implantation. Push-in tests suggested that the bonding of the CA coating to Ti is clinically acceptable. Therefore, we conclude that CA coating to Ti by the ASC method would be possible for clinical applications, including dentistry.

Strong chiroptical activity from achiral gold nanorods assembled with proteins

The optical activity of side-by-side gold nanorod assembly induced by interaction with proteins has the highest anisotropy factor in colloidal solution.

Cytochrome P450 CYP71BE5 in grapevine (Vitis vinifera) catalyzes the formation of the spicy aroma compound (-)-rotundone

(-)-Rotundone is a potent odorant molecule with a characteristic spicy aroma existing in various plants including grapevines (Vitis vinifera). It is considered to be a significant compound in wines and grapes because of its low sensory threshold and aroma properties. (-)-Rotundone was first identified in red wine made from the grape cultivar Syrah and here we report the identification of VvSTO2 as a α-guaiene 2-oxidase which can transform α-guaiene to (-)-rotundone in the grape cultivar Syrah. It is a cytochrome P450 (CYP) enzyme belonging to the CYP 71BE subfamily, which overlaps with the very large CYP71D family and, to the best of our knowledge, this is the first functional characterization of an enzyme from this family. VvSTO2 was expressed at a higher level in the Syrah grape exocarp (skin) in accord with the localization of (-)-rotundone accumulation in grape berries. α-Guaiene was also detected in the Syrah grape exocarp at an extremely high concentration. These findings suggest that (-)-rotundone accumulation is regulated by the VvSTO2 expression along with the availability of α-guaiene as a precursor. VvSTO2 expression during grape maturation was considerably higher in Syrah grape exocarp compared to Merlot grape exocarp, consistent with the patterns of α-guaiene and (-)-rotundone accumulation. On the basis of these findings, we propose that VvSTO2 may be a key enzyme in the biosynthesis of (-)-rotundone in grapevines by acting as a α-guaiene 2-oxidase.

In vivo evaluation of composites of PLGA and apatite with two different levels of crystallinity

The cortical bone response towards poly(lactide-co-glycolide) (70/30) (PLGA) (70/30)/apatite complex scaffolds with different levels of crystallinity was investigated. Apatite with different levels of crystallinity, Ca-deficient hydroxyapatite (CDHA), which has a low crystallinity, and a mixture of carbonated hydroxyapatite (CHA) and CDHA, which has a higher crystallinity, were prepared from an aqueous mixture of Ca-EDTA complex, H(2)O(2), H(3)PO(4), and NH(4)OH. Two porous PLGA(70/30)/apatite composite scaffolds, composite scaffold A (containing low crystallinity CDHA) and composite scaffold B (containing the higher crystallinity CHA/CDHA mixture), were prepared. Afterwards, pure porous PLGA and the two composite scaffolds were implanted into the cortical bone of rabbit tibiae for 12 weeks. High-resolution microfocus X-ray computed tomography and histological examinations revealed a better bone response for composite scaffold A compared with PLGA and composite scaffold B. For composite scaffold A, the original bone defect was almost filled with new bone. Quantitative analysis revealed that composite scaffold A produced a significantly greater amount of new bone. The present study demonstrated that the level of apatite crystallinity influences bone response. A PLGA/apatite porous composite with a low level of apatite crystallinity shows promise as a bone substitute or scaffold material for bone tissue engineering.

A case of small bowel adenocarcinoma in a patient with Crohn’s disease detected by PET/CT and double-balloon enteroscopy

Small bowel adenocarcinoma (SBA) in patients with Crohn’s disease (CD) is quite rare, difficult to diagnose without surgery, and has a poor prognosis. Here, we report a 48-year-old man with SBA and a 21-year history of CD who was diagnosed by a combination of positron emission tomography/computed tomography (PET/CT) and double-balloon enteroscopy (DBE). Since the age of 27 years, the patient had been treated for ileal CD and was referred to our hospital with persistent melena. Multiple hepatic tumors were found by CT. PET/CT detected an accumulation spot in the small bowel. DBE revealed an ulcerative tumor in the ileum about 100 cm from the ileocecal valve. An endoscopic forceps biopsy specimen showed poorly differentiated adenocarcinoma. There were some longitudinal ulcer scars near the tumor, and the chronic inflammation in the small bowel appeared to be associated with the cancer development. Previous reports suggest the risk of SBA in patients with CD is higher than in the overall population. Since early diagnosis is extremely difficult in these cases, novel techniques, such as PET/CT and DBE, may be expected to help in making a preoperative diagnosis of the development of SBA in CD.

Effect of thin carbonate-containing apatite (CA) coating of titanium fiber mesh on trabecular bone response

The influence of thin carbonate-containing apatite (CA) coating on trabecular bone response to cylindrical titanium fiber mesh (porosity of 85%, pore size of 200-300 microm, 2.8 mm diameter x 6 mm length) implants was investigated. Thin CA coatings were deposited by the so-called molecular precursor method. Molecular precursor solution was obtained by adding dibutylammonium diphosphate salt to Ca-EDTA/amine ethanol solution by adjusting Ca/P = 1.67. Sintered cylindrical titanium fiber mesh was immersed into molecular precursor solution and then tempered at 600 degrees C for 2 h. The immersion and tempering process was repeated three times. An adherent thin CA film could be deposited on the inside of titanium fiber mesh. After the immersion of a CA-coated titanium fiber mesh in simulated body fluid, apatite crystals precipitated on the titanium fiber mesh. Uncoated and CA-coated titanium fiber mesh was inserted into the trabecular bone of the left and right femoral condyles of rabbits. Histological and histomorphometrical evaluation revealed a significantly greater amount of bone formation inside the porous area of the CA-coated titanium fiber mesh after 12 weeks of implantation. The present results suggested that a thin CA-coated titanium mesh has better osteoconductivity and will be useful for a three-dimensional scaffold.

Clinicopathological features of gastric cancer detected by endoscopy as part of annual health checkup

BACKGROUND AND AIM

Upper gastrointestinal endoscopy is generally accepted as the gold standard for the clinical evaluation of gastric cancer (GC). However, the efficacy of endoscopic screening for asymptomatic GC remains controversial. The present study is designed to clarify the efficacy of endoscopic screening for the detection of early GC by investigating the clinicopathological features.

METHODS

A total of 17 522 patients who had underwent endoscopic screening as a part of their annual health checkup at the Seirei Center for Health Promotion and Preventive Medicine between April 2002 and March 2006 were enrolled in this study. We investigated the clinicopathological findings of GC detected by endoscopy. Furthermore, in accordance with the screening interval at our center, patients with GC were categorized into two groups: group A, patients with repeated endoscopic screening within the last 2 years, and group B, patients without endoscopic screening within the last 2 years.

RESULTS

Thirty-nine GC (mean age of patients: 62.2 +/- 8.0 years, 36 males and three females) were detected in total (0.22%). The proportion of early GC was 87.2%. Notable differences between groups A and B were not found in the rate of early GC (P = 0.6342). However, eight of 27 cases (29.6%) in group A were treated by endoscopic resection, but none in group B (P = 0.0344). In six of 26 cases (23.1%) in group A, the recorded images from the previous endoscopic examination indicated some macroscopic abnormalities at the same location, suggesting GC or premalignant lesions.

CONCLUSION

Endoscopic screening is useful for detecting GC at the early stages, and repeated examinations at short-time intervals contribute to the detection of resectable lesions by endoscopy. Further studies are needed to decrease the false negative rate of endoscopic screening.

Alteration of intracellular histamine H2 receptor cycling precedes antagonist-induced upregulation

Long-term administration of a histamine H2 receptor (H2R) antagonist (inverse agonist) induces upregulation of H2R in parietal cells, which may be relevant to the rebound hypersecretion of gastric acid that occurs after withdrawal of treatment. The mechanisms underlying this effect are unknown. We hypothesized that the H2R upregulation could be related to receptor trafficking and used H2R-green fluorescent protein (H2R-GFP) to test the hypothesis. Human H2R-GFP was generated and functionally expressed in HEK-293 cells. Binding of the H2R antagonist [3H]tiotidine was performed to quantify H2R expression, and H2R-GFP was imaged in living cells by confocal and evanescent wave microscopy. The binding affinity of [3H]tiotidine was not significantly different between H2R-GFP- and wild-type H2R-expressing HEK-293 cells, both of which had constitutive activity of adenylate cyclase. Visualization of H2R-GFP revealed that the agonist-induced H2R internalization and the antagonist-induced recycling of the internalized H2R from the recycling endosome within 2 h. Long exposure to the antagonist increased GFP fluorescence in the plasma membrane and also induced upregulation of H2R-GFP estimated by the binding assay, whereas long exposure to the agonist enhanced degradative trafficking of H2R-GFP. We examined whether the upregulation reflected an increase in receptor synthesis. Treatment with antagonist did not augment H2R mRNA, and subsequent inhibition of protein synthesis by cycloheximide had no effect on H2R upregulation. These findings suggested that upon exposure to an antagonist (inverse agonist), the equilibrium between receptor endocytosis and recycling is altered before H2R upregulation, probably via suppressing H2R degradation.

Growth and maturation of small hepatocytes

Proliferation of adult rat hepatocytes is observed in serum-free Dulbecco's modified Eagle's medium (DMEM) supplemented with 10 mmol/L nicotinamide and 10 ng/mL epidermal growth factor (EGF). The proliferating cells are mainly mononucleate and form small cell colonies surrounded by mature hepatocytes. Although these cells in focal colonies have a less-differentiated appearance, immunocytochemically and ultrastructurally they possess hepatic characteristics. The size of small hepatocytes is one-third to half that of mature hepatocytes. Therefore, we call the cells forming a colony, small hepatocytes. The small hepatocytes can be subcultured for several passages. Furthermore, the cells are rich in the supernatant following 50 g centrifugation for 1 min after collagenase liver perfusion. When the cells are cultured in DMEM supplemented with 10% foetal bovine serum, 10 mmol/L nicotinamide, 1 mmol/L ascorbic acid 2-phosphate, 10 ng/mL EGF and 1% dimethyl sulphoxide, each small hepatocyte can clonally proliferate for more than 3 months. A small hepatocyte divides to form a colony and the number of cells reaches more than 100 within 20 days. With time in culture, cells with a large cytoplasm appear within a colony. They have many mitochondria and large peroxisomes with crystalline nucleoids and are typical, mature hepatocytes. Immunoreactivity to connexin 32 and well-developed bile canaliculus structures are often observed in the cell-cell borders. Thus, we suggest that small hepatocytes may be considered to be 'committed progenitor cells' that can further differentiate into mature hepatocytes.

Growth and maturation of small hepatocytes

Proliferation of adult rat hepatocytes is observed in serum-free Dulbecco's modified Eagle's medium (DMEM) supplemented with 10 mmol/L nicotinamide and 10 ng/mL epidermal growth factor (EGF). The proliferating cells are mainly mononucleate and form small cell colonies surrounded by mature hepatocytes. Although these cells in focal colonies have a less-differentiated appearance, immunocytochemically and ultrastructurally they possess hepatic characteristics. The size of small hepatocytes is one-third to half that of mature hepatocytes. Therefore, we call the cells forming a colony, small hepatocytes. The small hepatocytes can be subcultured for several passages. Furthermore, the cells are rich in the supernatant following 50 g centrifugation for 1 min after collagenase liver perfusion. When the cells are cultured in DMEM supplemented with 10% foetal bovine serum, 10 mmol/L nicotinamide, 1 mmol/L ascorbic acid 2-phosphate, 10 ng/mL EGF and 1% dimethyl sulphoxide, each small hepatocyte can clonally proliferate for more than 3 months. A small hepatocyte divides to form a colony and the number of cells reaches more than 100 within 20 days. With time in culture, cells with a large cytoplasm appear within a colony. They have many mitochondria and large peroxisomes with crystalline nucleoids and are typical, mature hepatocytes. Immunoreactivity to connexin 32 and well-developed bile canaliculus structures are often observed in the cell-cell borders. Thus, we suggest that small hepatocytes may be considered to be 'committed progenitor cells' that can further differentiate into mature hepatocytes.

[Granulocyte colony stimulating factor (G-CSF) producing renal cell carcinoma]

A 88-year-old male patient with G-CSF producing renal cell carcinoma is reported. The patient was admitted to our hospital complaining of macrohematureia. The laboratory examination showed marked leukocytosis of 18,200/microliter (neutrophil 92%) in the peripheral blood and high levels of G-CSF (120 pg/ml) in the serum. An abdominal CT scan revealed a right renal tumor. The neutrophil count rose to 38,700/microliter with increasing of tumor size. Histopathological diagnosis was renal cell carcinoma (Grade 3) and immunohistochemical staining using Histo anti-G-CSF antibody demonstrated cancer cells produced G-CSF. This is the second case of G-CSF producing renal cell carcinoma diagnosed by immunohistochemical staining in the literature.

Different changes in expression and function of connexin 26 and connexin 32 during DNA synthesis and redifferentiation in primary rat hepatocytes using a DMSO culture system

In the present study, we determined in detail the changes of liver gap junctions, connexin 26 (Cx26), and connexin 32 (Cx32), during DNA synthesis and redifferentiation of hepatocytes in vitro. We used primary rat hepatocytes that expressed the liver gap junction proteins, which were cultured in the medium containing epidermal growth factor (EGF) with 2% dimethylsulfoxide (DMSO) and 10(-7) mol/L glucagon (a DMSO culture system), as we previously reported. In the present cultures, almost confluent hepatocytes cultured in the medium containing EGF with 2% DMSO and 10(-7) mol/L glucagon, underwent a nearly synchronous wave of DNA synthesis induced by the removal of 2% DMSO and 10(-7) mol/L glucagon, and the addition of 10 mmol/L nicotinamide, after which the DNA synthesis was completely re-inhibited by the re-addition of 2% DMSO and 10(-7) mol/L glucagon. During stimulation of DNA synthesis, both Cx26 and Cx32 messenger RNA (mRNAs) in hepatocytes transiently increased in the G1 phase and then markedly decreased before the onset of the S phase, while only Cx26 messenger RNA (mRNA) increased slightly in the S/M phase. Furthermore, before the onset of the S phase, a disappearance of both Cx26 and Cx32 immunoreactivities and gap junction plaques were observed. Gap junctional intercellular communication (GJIC), as measured by lucifer yellow, which indicated the function of Cx32, decreased markedly from before the onset of the S phase. GJIC measured by propidium iodide, which indicated the function of Cx26, decreased from before the onset of the S phase and then increased slightly in the S/M phase. During the re-inhibition after the stimulation of DNA synthesis, Cx32 mRNA, but not Cx26 mRNA, rapidly returned to the pretreatment control level. Cx32 immunoreactivity and gap junction plaques also recovered. However, the recovery of GJIC measured by lucifer yellow was later than that of Cx32 expression. These results indicated the different changes of expression and function of Cx26 and Cx32 in the hepatocytes during stimulation and re-inhibition of DNA synthesis. This culture system should be useful as a model in which to study liver gap junctions during hepatocyte growth and differentiation in vitro.

Effects of melatonin on proliferation, oxidative stress and Cx32 gap junction protein expression in primary cultures of adult rat hepatocytes

Melatonin has antiproliferative and antioxidant effects on cells in vivo and in vitro. Gap junctions mediate the communication between adjacent cells and are closely related to cellular growth and oxidative stress. We previously reported that 2% dimethylsulfoxide (DMSO) which has antiproliferative and antioxidative effects on hepatocytes, induces connexin 32 (Cx32) gap junction protein in primary cultures of adult rat hepatocytes. In the present study, we have examined the effects of melatonin on proliferation, oxidant stress and Cx32 gap junction protein expression in the cultured rat hepatocytes as compared to 2% DMSO treatment. 10(-2) M melatonin significantly inhibited the proliferation and the oxidative stress of the cells, and markedly induced Cx32 gap junction protein expression and gap junctional intercellular communication (GJIC). These effects of 10(-2) M melatonin treatment were not due to cytotoxicity to the cultured rat hepatocytes and they were as strong as those of 2% DMSO treatment. These results suggested that melatonin might be a useful substance to maintain the functions of the hepatocytes in vitro by modulating the levels of proliferation, oxidative stress and gap junction expression.

Formation of actin filament networks in cultured rat hepatocytes treated with DMSO and glucagon

Actin filament organization may play an important role in the maintenance of differentiated functions in epithelial cells. We previously reported our success in inducing and maintaining gap junctions, which are two kinds of differentiated function, in primary rat hepatocytes cultured with 2% DMSO and 10-7 M glucagon. In the present study, we demonstrated the formation of actin filament networks in the hepatocytes cultured with 2% DMSO and 10-7 M glucagon. Actin filaments in hepatocytes cultured in medium with only 2% DMSO added from 96 h after plating were concentrated under the plasma membrane and were observed to be circumferential. In hepatocytes cultured in the medium with both 2% DMSO and 10-7 M glucagon added from 96 h, not only the circumferential actin filaments but also the formation of actin filament networks were observed and the networks developed well with time in culture. The networks were observed as a dome-like structure under the cell face and terminated at the circumferential actin filaments. They were composed of electron-dense star-like vertices connected by microfilament bundles of varying length and were also very sensitive to the actin disruptor cytochalasin B. However, during the network formation, there were no significant increases in the amounts of actin protein and mRNA. The actin filament networks of the hepatocytes in this culture system might be closely related to the maintenance of differentiated functions.

[Utility of daily oral administration of etoposide in 25 cases of refractory hematological malignancies]

We estimated the utility of daily oral administration of etoposide (ETOP) in 25 cases of refractory hematological malignancies who had been admitted to our hospital between February, 1988 and October, 1995. Patients were 9 cases of malignant lymphoma, 7 cases of adult T cell leukemia (ATL), 7 cases of acute leukemia, 1 case of primary macroglobulinemia, and 1 case of chronic lymphocytic leukemia (CLL). Eight cases were elderly patients over 65 years old, 7 cases were refractory to previous chemotherapies, and 13 cases were relapsed cases. ETOP was administered at 25 or 50 mg per day for at least more than 3 consecutive weeks, if the peripheral white blood cell count exceeded 1,000/microliter. Complete and partial responses were obtained in 64% of all cases, especially in 81% of malignant lymphoma and ATL. Probability of survival for 3 years of malignant lymphoma and ATL was 36.7%. As mild toxicities, 2 cases (8%) had nausea and vomiting, 2 cases (8%) had diarrhea, and 3 cases (12%) had stomatitis. Grade 3 leukocytopenia was observed in 16% of cases. Twelve out of 16 evaluable patients recovered in performance status (PS) after this therapy. Daily oral administration of ETOP might be an effective therapy for refractory hematological malignancies, especially for malignant lymphoma.

Pulmonary veno-occlusive disease accompanied by microangiopathic hemolytic anemia 1 year after a second bone marrow transplantation for acute lymphoblastic leukemia

Although hepatic veno-occlusive disease (HVOD) is a common complication of allogenic bone marrow transplantation (BMT), pulmonary veno-occlusive disease (PVOD) is very rare. Only three cases have been described in the literature. We report the case of a 19-year-old woman who developed PVOD accompanied by microangiopathic hemolytic anemia (MAHA) and hemolytic uremic syndrome (HUS) 1 year after a second BMT for relapsed acute lymphoblastic leukemia (ALL). Autopsy examination revealed obstruction of the small pulmonary veins with edematous thickening of the intima. These findings are compatible with PVOD. Pulmonary GVHD and pulmonary aspergillosis were also observed. Various etiologic factors have been implicated in PVOD after BMT. We postulate that pulmonary GVHD and pulmonary infection including aspergillosis played an important role in the occurrence of both PVOD and HUS in our patient. Microangiopathic cytokines released in response to the GVHD and infection may damage the intima of microvessels that were previously injured by the two BMT. Despite appropriate therapy, the microangiopathic process was irreversible and the patient died. Thus, measures must be taken to prevent and treat PVOD after BMT.

Syndrome of the sea-blue histiocyte

A 39-year-old male was admitted with fever, systemic lymph node swelling, liver dysfunction and mild splenomegaly. Liver biopsy specimen showed histiocytic aggregation in portal areas. These histiocytes were closely packed with granules, dyed sea-blue with May-Giemsa staining. Further microscopical examination of lymph nodes, gastro-intestinal tract and bone marrow also revealed the accumulation of sea-blue histiocytes. Activities of lipid metabolic enzymes were normal and hematopoietic diseases which are sometimes accompanied by secondary sea-blue histiocytosis were ruled out. We diagnosed this case as syndrome of the sea-blue histiocyte.

[Investigation of reinforcement of the free enamel--the adhesive strength test and SEM observation by using the composite resin]

In this study, the purpose of which is to examine reinforcement of free enamel, we employed visible light-cured adhesive composite resins applied to the inner surface of free enamel and the enamel surface. An Autograph DCS-5000 was used to measure physical tensile shearing strength; a scanning electron microscope (SEM) was used to observe the fracture surface of the adhesive area between the enamel and the composite resin. Results 1. Adhesive strength on the inner surface of free enamel was about 20% lower than that of the enamel surface. Nonetheless, we judged the inner surface of free enamel to have adhesive strength. 2. SEM observation showed that breaking occurred at the boundary of the adhesive surface between the enamel and the bonding material. It is possible to expect a certain amount of reinforcement of free enamel from the use of composite resins.

Trapeziometacarpal abnormalities in Ehlers-Danlos syndrome

We studied 24 patients with Ehlers-Danlos syndrome with particular attention to the thumb and the trapeziometacarpal joint. The 11 males and 13 females had a mean age of 15.9 years. Symptomatic complaints included pinch, grip and twisting weakness; measurements showed dominant hand strength deficits of 71% for tip pinch, 55% for palmar pinch, 46% for key pinch, and 70% for grip. All finger joint ranges of motion were increased. Sixty-six percent of all the patients had trapeziometacarpal subluxation; 29% had dislocation. Sixteen percent had radiographic evidence of arthritis. Early occupational therapy evaluation and education can help these patients better understand and adapt to their limitations.

Comparative effects of choline chloride and phosphatidylcholine on plasma and liver lipid levels in rats fed a choline-deficient high cholesterol diet

The effects of dietary choline chloride and phosphatidylcholine (PC) on plasma and liver lipid levels were investigated with rats fed a choline-deficient high cholesterol diet. The plasma cholesterol level significantly increased as the dietary level of choline chloride was increased. The addition of PC to the choline-free diet also resulted in an increase in the plasma cholesterol level, but the magnitude of the increase was significantly lower than that by choline chloride. There was no difference, on the other hand, in the effect of choline chloride and PC on the plasma triglyceride level. The contents of cholesterol and triglyceride in the liver markedly decreased in rats fed a diet containing PC at a high level. The fecal excretion of neutral sterol significantly increased by the addition of PC at a high level, but not at a low level. The results indicate that the plasma cholesterol level, but not triglyceride, is differentially influenced by dietary choline chloride and PC, and that PC has both hyper- and antihypercholesterolemic effects when compared with a choline-free diet and a diet supplemented with choline chloride, respectively.

Coxa magna following surgical treatment of congenital hip dislocation

We studied coxa magna after operative treatment of congenital dislocation of the hip, including incidence, relationship to treatment, and influence of coxa magna on the acetabulum. Coxa magna was defined as a femoral head with a horizontal diameter at least 15% greater than the symmetrical position on the opposite side. Coxa magna developed in 16 hips (33%). The mean increase was 20.9% (range 15-30%). Three factors correlated with coxa magna: femoral osteotomy (100%), open reduction (75%), and operation at a younger age (mean 15.6 vs. 35.8 months). Four of the 16 hips developed coxa magna following Type 1 avascular necrosis; no other growth deformities appeared. At follow-up, the acetabular indices and the center edge angles were not statistically different between the coxa magna and the control groups. One must avoid confusing coxa magna with hip subluxation or inadequate reduction, of which the latter requires appropriate treatment. Coxa magna gives a good hip if a concentric, congruous reduction is obtained, providing the acetabulum has enough growth potential for remodeling.

Severe neutropenia associated with sustained-release procainamide

Neutropenia is a rare complication of procainamide therapy. However, over a period of 20 months, 8 patients developed severe neutropenia while taking a sustained-release preparation of the drug. Seven patients presented with fever and constitutional symptoms and one patient was asymptomatic. Bone marrow examinations showed myeloid aplasia or maturation arrest in 5 patients and myeloid hyperplasia in 1. Neutropenia resolved within 30 days of drug withdrawal, and all patients survived. A case-control study showed a significant association between sustained-release procainamide therapy and severe neutropenia in 5 of 114 patients (4.4%) recovering from open-heart surgery (Mantel-Haenszel chi square = 13.84; p less than 0.001). Thus, life-threatening neutropenia may be common with sustained-release procainamide preparations.