Induction of carcinomas and sarcomas by 9,10-dimethyl-1,2-benzanthracene administration into the hamster maxillary sinus

To determine whether the local administration of 9,10-dimethyl-1,2-benzanthracene (DMBA) into the hamster maxillary sinus induced carcinoma at the injected site, hamsters were injected with 30 microliters of 0.5% solution of DMBA in dimethyl sulfoxide (DMSO) through the infraorbital foramen into the maxillary sinus once weekly for 10 weeks (Group 2). Another group of hamsters (Group 1) received similar injections of 30 microliters of DMSO only. In a third group of animals (Group 3), a roll of oxycellulose was inserted into the maxillary sinus and 40 microliters of a 2% solution of DMBA in DMSO was injected once. Sinonasal carcinomas were demonstrated in 73% (8/11) of the hamsters in Group 2 and sarcomas were shown in 73% (8/11) of the hamsters in Group 3, as well as some carcinomas. No tumors were seen in the Group 1 hamsters. Histologic examination revealed squamous cell carcinomas arising from the surface epithelium and submucous glands of the nasal cavity and maxillary sinus. These findings indicate that the intrasinal administration of a 0.5% solution of DMBA in DMSO is a reliable method for inducing maxillary sinus cancer.

Unique molecular properties of superoxide dismutase from teleost fish skin

A unique Cu,Zn-SOD was found and isolated from plaice Paralichthys olivaceus skin. Surprisingly, the properties of purified fish skin SOD were very different from those of SOD from other sources reported so far. The purified SOD was composed of four same subunits of 16 kDa and the molecular weight of the native SOD was found to be around 65 kDa. The dominant amino acids of the SOD were Ser, Thr, Pro and Glu. Above 70 degrees C, thermostability of the SOD was much lower than that of bovine erythrocyte Cu,Zn-SOD.

Demonstration that histidine 25, but not 132, is the axial heme ligand in rat heme oxygenase-1

A truncated, soluble rat heme oxygenase-1 lacking its C-terminal, membrane-anchoring segment, and its His25-->Ala and His132-->Ala mutants have been prepared by site-directed mutagenesis and expression in Escherichia coli. We found that wild-type enzyme can degrade heme to biliverdin, but its specific activity was about one-fifth that of the native, full-length enzyme, suggesting that the C-terminal segment is important for accepting electrons from NADPH cytochrome P450 reductase. His132-->Ala mutant had an enzyme activity comparable to that of the wild-type enzyme; hence, the highly conserved His132 is not essential for the display of the heme oxygenase activity. In contrast, His25-->Ala mutation completely abolished the enzyme's catalytic activity. A five-coordinate type ferrous NO EPR spectrum was observed for the heme-heme oxygenase H25A complex. Hence, we conclude that His25 is the proximal axial ligand of the heme iron and is essential for the heme degradation activity of the enzyme.

Cellular fatty acids and aldehydes of oral Eubacterium

The cellular fatty acids and aldehydes of oral Eubacterium species were determined by gas chromatography-mass spectrometry. E. brachy and E. lentum contained mainly branched-chain fatty acids, whereas the others contained straight-chain acids. E. brachy, E. lentum, E. yurii ssp. yurii, E. yurii spp. margaretiae, E. limosum, E. plauti and E. aerofaciens also contained aldehydes with even carbon numbers. In addition to species-specific components, the compositional ratios of fatty acids and aldehydes characterized each individual species. The 10 species tested were divided into 5 groups by the principal component analysis. Cellular fatty acids and aldehydes would be chemical markers for interspecies differentiation of oral Eubacterium.

Identification and biochemical characterization of human plasma neutrophil inhibitor in vitro

In this study, assessment by a flow cytometric method using dichlorhydroxy fluorescin diacetate (DCFADH) in vitro revealed that human peripheral blood inhibits the production of active oxygen species by human peripheral neutrophils. It was also revealed that among the blood components, the plasma fraction inhibits active oxygen production most strongly. This plasma inhibitory activity was dose-dependent. Human serum also exerted an inhibitory activity; however, its activity was only one-third that of plasma. Moreover, when HL-60 human promyelocytic leukemic cells, with or without differentiation into the neutrophils by culturing with dimethyl sulfoxide (DMSO), active oxygen, which was also inhibited by plasma, was produced. Heat inactivation of the plasma did not alter the inhibitory activity, and gel filtration analysis showed that the peak activity was associated with a molecular mass of 70,000. The results of this study indicate that human plasma contains one or more substances that inhibit the active oxygen production of neutrophils, which may play an important role in inhibiting unneeded neutrophil activation in the bloodstream.

[Two diabetics with hemichorea-hemiballism and striatal lesions]

We report two diabetic patients with hemichorea-hemiballism associated with striatal lesions detected by MRI. Case 1 was a 57-year-old woman. On May 5, 1990, hemichorea-hemiballism of the right upper extremity developed suddenly. The blood glucose level at the time of onset was 695 mg/dl. Plain cranial CT scanning revealed a small high-density lesion in the left putamen. On MRI, this lesion showed a high signal intensity on T1-weighted images, while it showed as an irregular low-intensity area on T2-weighted images. Three and a half months later, the high intensity lesion on MRI decreased gradually and almost disappeared. Case 2 was a 68-year-old woman. In late August 1992, hemichorea-hemiballism of the right upper and lower extremities developed suddenly. The blood glucose level at the time of onset was 365 mg/dl. Plain cranial CT scanning was normal. MRI revealed a high signal intensity lesion involving the left putamen, globus pallidus and head of the caudate nucleus on T1-weighted images, while the lesion was almost isointense on T2-weighted images. The high-intensity lesion on MRI thereafter decreased gradually and disappeared almost completely one year after the onset. It is characteristic that the lesions responsible for hemichorea-hemiballism showed high-intensity areas on T1-weighted MRI in these two diabetics. In the hyperglycemic state, the Krebs cycle is inhibited and GABA is utilized as an energy source. The possibility has been suggested that striatal ischemia is likely to occur in diabetics because the GABA content of the corpus striatum is decreased by hyperglycemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Antioxidative roles of metallothionein and manganese superoxide dismutase induced by tumor necrosis factor-alpha and interleukin-6

Antioxidative roles of metallothionein (MT) and manganese superoxide dismutase (Mn-SOD) induced by tumor necrosis factor (TNF) and interleukin 6 (IL-6) have been studied. Since pretreatment of rat with dexamethasone, an inhibitor of cytokine production, prevented MT synthesis induced by paraquat which is a typical superoxide generator, MT synthesis by oxidative stress may be, at least partly, mediated through cytokines. Pretreatment of rat with TNF or IL-6 prevented liver damage and lipid peroxidation caused by carbon tetrachloride. Administration of TNF increased activity of mitochondrial Mn-SOD and concentrations of cytoplasmic MT, but not activities of glutathione peroxidases and Cu,Zn-SOD in the liver. The increment of the Mn-SOD activity and MT was due to the de novo protein synthesis, because gene expression of mRNAs of Mn-SOD and MT in the liver was also induced by TNF and IL-6. These data strongly suggest that MT and Mn-SOD in the liver cooperatively play antioxidative roles. Pretreatment with TNF, however, did not affect the increased levels of plasma fibrinogen and liver MT induced by the following paraquat treatment, although it did prevent lipid peroxidation in the liver. The data suggest that MT is not directly induced by oxygen free radicals. Cytokines may be released by paraquat in tissues other than the liver and induce hepatic synthesis of acute phase proteins including fibrinogen, MT, and Mn-SOD. MT and Mn-SOD induced by cytokines in the liver exert an antioxidative role during acute phase response, therefore preventing tissues from injury by oxidative stress.

Transforming growth factor-beta 1 proliferated vascular smooth muscle cells from spontaneously hypertensive rats

To clarify whether the growth inhibitors, transforming growth factor-beta 1 (TGF-beta 1), heparin, and interferon-gamma (IFN-gamma) contribute to the development of vascular hypertrophy in spontaneously hypertensive rats (SHR), the growth of vascular smooth muscle cells (VSMC) was evaluated both for cell numbers over a period of 4 days, and [3H]thymidine incorporation over 24 h. Heparin and IFN-gamma inhibited the proliferation of VSMC from SHR and Wistar-Kyoto (WKY) rats. TGF-beta 1 enhanced SHR-VSMC proliferation by 16.6 +/- 8.9%; in contrast TGF-beta 1 inhibited WKY-VSMC proliferation by 60.5 +/- 7.4%. There was no difference in affinity, number of binding sites, or subtype expression of TGF-beta 1 receptor between SHR-VSMC and WKY-VSMC. This evidence suggests that the signal transduction system of TGF-beta 1 either the receptor itself or downstream signaling molecules, may be altered in SHR-VSMC versus WKY-VSMC. This abnormal responsiveness to TGF-beta 1 is involved in the proliferative characteristics of SHR-VSMC. Therefore, TGF-beta 1 could contribute to the development of hypertension or vascular hypertrophy in SHR.

Magnetic resonance imaging of the central nervous system in the kitten

The optimum technical conditions for magnetic resonance imaging (MRI) of the central nervous system (CNS) in the 3-week-old kitten were investigated with a low (0.2 T) magnetic field MRI unit equipped with a custom-made solenoid radio frequency (RF) coil. In the brain, T1 weighted images (TR/TE = 500/38 msec) and T2 weighted images (TR/TE = 1,800/110 msec) clearly delineated each anatomical portion of the brain. In the spinal cord, T2 weighted images (TR/TE = 1,500/110 msec) demonstrated structures distinctly. These results suggest that even low magnetic field MRI can be used for noninvasive scanning of small animals including new born animals.

Possible involvement of the transcription factor ISGF3 gamma in virus-induced expression of the IFN-beta gene

Two virus-inducible transcription factors, IRF-1 and IRF-2 have been identified as an activator and a repressor, respectively, of the type I interferon (IFN) genes. Recent studies with mice carrying null mutations for the IRF-1 or IRF-2 alleles have revealed the existence of IRF-1-dependent and -independent pathways mediating IFN-beta gene induction. Here we report that the expression of an IRF family member ISGF3 gamma is induced upon viral infection in IRF-1-/-, IRF-2-/- embryonic fibroblasts. Furthermore, ISGF3 gamma can bind to a virus-inducible promoter element in the IFN-beta gene. These results suggest that ISGF3 gamma or complex containing ISGF3 gamma is involved in the IRF-1-independent pathway mediating IFN-beta gene regulation.

Effect of local administration of epidermal growth factor on 9,10-dimethyl-1,2-benzanthracene-induced tumour formation in hamster cheek pouch

The effect of local administration of epidermal growth factor (EGF) on 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced tumour formation was investigated in a hamster cheek pouch carcinogenesis model. DMBA-treated hamsters underwent either sialoadenectomy (groups 1 and 2) or a sham operation (groups 3 and 4). Thereafter, EGF (groups 1 and 3) or vehicle (groups 2 and 4) was applied to the cheek pouches for 6 weeks. Fourteen weeks after the beginning of the experiment, the number of cheek pouch tumours was significantly greater in EGF-treated hamsters than in vehicle-treated hamsters, irrespective of whether the submandibular glands had been removed. The number of forestomach tumours, induced by DMBA application to the cheek pouches, was also increased by EGF. These results suggest that EGF applied from the luminal side of the mucosa stimulates tumour formation in the hamster cheek pouch and forestomach.

Differentiation dependent expression of tensin and cortactin in chicken osteoclasts

The expression and localization of tensin and cortactin were examined in osteoclast precursors in comparison with isolated osteoclasts on various substrates. Initially, the ability of hen monocytes to differentiate into osteoclasts was evaluated on plastic or glass, and compared to differentiation on bone. Specifically, monocytes were isolated from the medullary bones of egg-laying hens maintained on a Ca-deficient diet. Differentiation was monitored morphologically and by quantitation of the ability to form Howship's lacunae in bone slices or resorb radiolabeled bone particles of 20-53 microns diameter. These cells differentiated into tartrate resistant acid phosphatase (TRAP)-positive, bone resorbing, multinucleated syncytia in the presence of cytosine-1-beta-D-arabinofuranoside in a time dependent manner (day 1-6). Differentiation into osteoclast-like cells was similar whether cultured on plastic, on glass, or on bone. When compared to GAP-DH control levels, tensin and cortactin mRNA levels increased by 7- and 10-fold, respectively, by day 6. Tensin and cortactin protein levels also increased by 6- and 15-fold, respectively, by day 6. Immunofluorescence of differentiating precursors showed that tensin localized between regions of cell to cell contact and colocalized with vinculin in podosomes of osteoclast-like cells and of real osteoclasts. Cortactin immunofluorescence was not detectable in monocytes but localized inside tensin/vinculin podosome structures after fusion into osteoclast-like cells and in freshly isolated osteoclasts. Both tensin and cortactin were associated with attachment complexes used by osteoclast-like cells and osteoclasts to resorb bone. Specifically, punctate cortactin staining was observed inside tensin staining which formed a double ring structure at the membrane/bone interface of resorbing osteoclasts. These data showed that tensin and cortactin can be used as osteoclast differentiation markers, that participate in attachment complexes used to resorb bone, and that tensin may participate in the fusion process of osteoclast precursors.

Space-cutting model of hydroxyapatite

The possibility of substitution of trace elements such as Mg2+, Sr2+ and Ba2+ into the columnar Ca2+ positions of hydroxyapatite was examined by computer graphics with a personal computer and a space-cutting method. Data on the structural coordinates of the hydroxyapatite were put into a protein graphics program in Angstrom units. The connection of each element, with front and rear, was displayed by the shade-line erasing method, and the solidity of the image was expressed by the degree of lightness from the light source. The space-cutting model was obtained by selecting the cutting plane with three atoms in the crystal. Rotating the graphics freely around the X, Y and Z axes gives a view from any direction. The computer graphics suggested visually how the lattice dimensions expand with Sr2+ and Ba2+ substitution and contract with Mg2+ substitution.

[Results of surgical treatment of intrathoracic recurrence after complete resection of non-small cell lung cancer: clinical significance of subsequent lesion in lung parenchyma]

Results of surgical treatment for 33 intrathoracic recurrence after complete resection of non-small cell lung cancer were analyzed. Prognosis of the second surgical treatment were favorable in patients with subsequent cancer with in situ component and solitary lesion in lung parenchyma. Retrospective study of 53 patients who recurred and were thoroughly followed up their clinical course until lung cancer death revealed that the solitary one tends to be confined to the intrathoracic location, and the multiple one did not confined to the intrathoracic location but also extended to the extrathoracic distant metastasis or to the supraclavicular lymph nodes.

Acute effects of inhalation exposure to carbon monoxide on schedule-controlled operant behavior and blood carboxyhemoglobin levels in rats

The acute effects of carbon monoxide (CO) exposure on a steady-state operant behavior (bar-pressing under a VI 60-sec schedule of food reinforcement) were repeatedly measured in (a) rats exposed to various concentrations of CO (500, 1,000, 1,500 and 2,000 ppm) for 1 h and (b) rats exposed to 1,500 ppm for different periods (1, 2 and 4 h). Measurements were made continuously before, during and after the exposure period. Abrupt cessation of the response was produced by exposure to 1,000 ppm or higher concentrations of CO. Recovery from the effects of CO exposure was observed as sudden resumption of responding during the post-exposure period. The duration of exposure required to produce response inhibition was closely correlated with the exposure concentration. The post-exposure interval required for response recovery was also correlated with the exposure concentration. This post-exposure response recovery interval, however, was constant and independent of the duration of exposure when the concentration was fixed at 1,500 ppm. In order to correlate these behavioral changes with an internal index of CO exposure, blood carboxyhemoglobin (HbCO) levels were determined under several exposure conditions corresponding to those of the behavioral observations. It was found that HbCO levels were within a certain range (33-43%) when response recovery occurred, suggesting the existence of a critical HbCO level (threshold) associated with the drastic behavioral change. Hence, these results support the view that blood HbCO is an important determinant of the acute behavioral effects of CO.

Long-term results of hepatic resection for hepatolithiasis

Long-term results of hepatic resection for hepatolithiasis in 34 patients having intrahepatic biliary strictures were studied. The left lateral and the right posterior segmental ducts were commonly and often simultaneously involved. Fourteen patients had multiple segmental involvement. Hepatic resection included left sided resection (n = 27), right sided resection (n = 6), and repeated bilateral resection (n = 1). Seven patients had biliary tumors: 3 cholangiocarcinomas, 2 gall bladder cancers, 1 cystadenocarcinoma, and 1 dysplasia of intrahepatic ducts. Nineteen patients received bilioenteric anastomosis. Retained stones and recurrent stones developed in 3 and 4 patients, respectively. Twenty-six patients had no remaining symptoms; 2 died of operative complication or cholangiocarcinoma; 6 presented symptoms caused by retained stones (n = 2), recurrent stones (n = 2), bile stasis (n = 1), or neuralgia (n = 1). In 4 of the 6 patients, unrelieved posterior duct strictures caused the symptoms. With a mean follow-up period of 4.5 years, 30 patients are symptoms free, and 27 are stone free. In patients with right lobar or bilobar type, intra- and extrahepatic type, and confluence strictures, bilioenteric anastomosis is required. Hepatic resection is a rational treatment for hepatolithiasis, however, meticulous management of biliary tract abnormalities, particularly the posterior duct stricture, is mandatory.

Interleukin 8 and biocompatibility of dialysis membranes

To determine whether interleukin 8 (IL-8) can be used as an index of biocompatibility of dialysis membranes, the effects of hemodialysis (HD) on plasma IL-8 levels and the expression of IL-8 mRNA in peripheral blood mononuclear cell (PBMC) were compared among regenerated cellulose (RC), polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) dialyzers. HD using RC dialysers significantly increased plasma IL-8 levels and induced abundant expression of IL-8 mRNA in PBMC. HD using PMMA dialyzers also increased plasma IL-8 levels and induced slight expression of IL-8 mRNA. In contrast, HD using PAN dialyzers neither increased plasma IL-8 levels nor induced the expression of IL-8 mRNA. In vitro studies demonstrated that IL-8 was considerably adsorbed by PAN membranes and not at all by RC and PMMA. These studies indicate that plasma IL-8 level and expression of PBMC IL-8 mRNA can be used as indices of biocompatibility of dialysis membranes.

[Chronic subdural hematoma with bleeding tendency; clinical analysis of 11 surgical cases]

Eleven patients with chronic subdural hematoma (CSDH) with bleeding tendency (BT) were surgically treated in the last 12 years. To study the clinical problem of CSDH with BT, 11 surgical cases were divided into 3 groups, Group A; CSDH with primary BT (1 case of hemophilia A), Group B; CSDH with BT secondary to a basic disease (3 cases of leukemia, 2 cases of malignant tumor with DIC, 1 case of chronic renal failure and 1 case of liver cirrhosis), Group C; CSDH with BT by anticoagulants (warfarin) (2 cases of replacement of mitral valve, 1 case of A-C bypass). Evacuation of the hematoma was performed by means of one or two burr holes with irrigation of the hematoma cavity and a drainage tube was placed in the subdural space. The outcome was excellent in Groups A and C. In Group B, two patients with DIC due to gastric cancer and prostatic cancer died, and 3 patients with leukemia recovered dramatically from CSDH, but the poor course of the disease itself resulted in death. The outcome of other patients in Group B was excellent. Since CSDH with BT is often fatal, those patient had usually been treated conservatively. However, from this analysis, we stress that CSDH with BT should be surgically treated after checking the blood conditions carefully to determine whether or not the patient has need for surgery.

[A case of renal vein thrombosis and pulmonary embolism associated with diffuse membranous glomerulonephritis: the usefulness of low-molecular-weight heparin and urokinase therapy]

We report a case of renal vein thrombosis (RVT) and pulmonary embolism associated with diffuse membranous glomerulonephritis. A 44-year-old Japanese male was referred to the Nephrology Department with heavy proteinuria. Renal biopsy revealed diffuse membranous glomerulonephritis and we administered PSL 30mg/day and dipyridamole 300mg/day. Three weeks later, he was admitted with severe chest pain, dyspnea and massive proteinuria. RVT and pulmonary embolism were detected on CT scan and perfusion lung scan. After a few days of continuous intravenous unfractionated heparin (UFH) therapy, we used 72 U (anti-FXa)/kg of intravenous low-molecular-weight heparin (LMWH) every 12 hours for 10 days. He also received urokinase at the dose of 120,000 U/day for 4 weeks and long-term therapy with warfarin potassium at the dose of 3 mg/day. One month later, the thrombi in the pulmonary arteries and inferior vena cava disappeared on CT scan and perfusion lung scan. LMWHs have a longer biological half-life and a lower bleeding tendency than UFH for an equivalent antithrombotic effect. This case indicates that intermittent intravenous LMWH administration combined with urokinase is effective against RVT and pulmonary embolism without any side effect.