Possible involvement of Janus kinase Jak2 in interferon-gamma induction of nitric oxide synthase in rat glial cells

To clarify the induction pathway of inducible nitric oxide (NO) synthase in the brain, we examined the effects of interferon-gamma and lipopolysaccharide on the induction of inducible NO synthase in glial cells cultured from neonatal rats, compared to those in the macrophage cell line RAW264.7 which was derived from Abelson leukemia virus-induced BALB/c lymphocytic lymphoma. NO synthase activity (NO2- accumulation) and 130 kDa protein of inducible NO synthase were induced 24 h after treatment with interferon-gamma or lipopolysaccharide in both glial cells and RAW264.7 macrophages. These induction activities were inhibited by a tyrosine kinase inhibitor, herbimycin A. Immunoprecipitation assay using antibodies against Janus kinases, and the signal transducer and activator of transcription-1 (STAT1), revealed that interferon-gamma induced tyrosine phosphorylation of the just another kinase-2 (Jak2) and STAT1 alpha but did not induced the phosphorylation of Jak1, the non-receptor tyrosine kinase-2 (Tyk2) and STAT1 beta. Tyrosine phosphorylation of Jak2 and STAT1 alpha induced by interferon-gamma was also inhibited by herbimycin A, while lipopolysaccharide did not induce any tyrosine phosphorylation of Janus kinases and STAT1 at all. These results suggest that the interferon-gamma-induced inducible NO synthase induction involves activation of Jak2-STAT1 alpha pathway in both glial cells and macrophages.

Selective cooperation of HTLV-1-encoded p40tax-1 with cellular oncoproteins in the induction of hematopoietic cell proliferation

Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T cell leukemia (ATL). The virus-encoded p40tax-1, a nuclear oncoprotein, is known to promote transcription of its own as well as a variety of cellular genes. However, the mechanism by which p40tax-1 promotes lymphocyte transformation is not fully understood. In the present study, we examined whether p40tax-1 can induce hematopoietic cell proliferation by cooperating with the products of cellular proto-oncogenes; i.e. an activated form of the src-family protein tyrosine kinase p56lck (lck F505), c-Myc or Bcl-2. These oncoproteins are critical mediators of interleukin 2 (IL-2)-induced proliferative signals. We show that p40tax-1 alone cannot render the hematopoietic cell line, BAF-B03, able to proliferate in the absence of cytokines, but it can do so in cooperation with lckF505, or c-Myc but not with Bcl-2.

The effects of intravitreally injected endothelin-1 on the iris-ciliary body microvasculature in rabbits

PURPOSE

We previously reported that intravitreal injection of 0.5 microg of endothelin-1 (ET-1) caused both a sustained reduction of intraocular pressure (IOP) and decreased aqueous production in the rabbit eye. On the theory that these effects might have resulted from a sustained reduction of blood flow to the ciliary body due to ET-1-mediated vasoconstriction, in the present study we attempted to determine if ET-1 causes any changes in the vascular caliber of the iris-ciliary body.

METHODS

ET-1 solution (0.5 microg) was injected into the vitreous of one eye of each of 10 albino rabbits; the same amount of vehicle was injected into the contralateral eyes. One h following these injections in five of the rabbits and 24 h following them in the other five rabbits, ocular microvascular castings were obtained under controlled physiologic conditions, and the amount of vasoconstriction of the arterioles branching from the major arterial circle of the iris (MAC) and supplying the iris-ciliary body was measured by a scanning electron microscope and expressed as a percentage.

RESULTS

The ET-1 caused a statistically significant focal vasoconstriction in the treated eyes as compared with the contralateral, control eyes (9.9% at 1 h and 6.2% at 24 h; both P = . 0001).

CONCLUSIONS

Intravitreally injected ET-1 caused statistically significant, but only mild vasoconstriction of the arterioles supplying the ciliary processes.

Ampullary somatostatinoma in a patient with von Recklinghausen's disease

We report a case of somatostatinoma of the ampulla of Vater associated with von Recklinghausen's disease in a 44-year-old woman. On admission the patient was jaundiced, and percutaneous Cholangio-drainage was performed. Cholangiography revealed stenosis of the common bile duct at the lower end Duodenoscopy showed a yellowish tumor of the ampulla of Vater, and the biopsy specimens showed no malignant cells. Pylorus-preserving pancreaticoduo-denectomy was performed. Histologically, the tumor was composed of small round cells with a solid or trabecular pattern and with multiple psammoma bodies. Immunohistochemical examination showed that the tumor cells stained for somatostatin. Genomic examination showed neither K-ras nor p53 gene mutations of the resected specimen.

Trabeculotomy ab externo, cataract extraction, and intraocular lens implantation: preliminary report

PURPOSE

To compare the results of a triple procedure using either extracapsular cataract extraction (ECCE) or one of two phacoemulsification techniques combined with trabeculotomy ab externo and intraocular lens (IOL) implantation.

SETTING

Kyoto University Hospital, Kyoto, Japan, and Nagata Eye Hospital, Nara, Japan.

METHODS

In this comparative study, 25 eyes with primary open-angle glaucoma had ECCE combined with trabeculotomy ab externo and IOL implantation and 22 had the same procedure using phacoemulsification instead of ECCE. Of the eyes that had phacoemulsification, 10 had a single-flap and 12 had a double-flap procedure.

RESULTS

All 22 eyes that had phacoemulsification had a postoperative IOP of 21 mm Hg or less, as did all ECCE eyes except 2. Although the self-sealing incision might have caused the higher incidence of IOP spikes in the immediate postoperative period, IOPs in the phacoemulsification groups were lower after 3 months. Results were similar in the single-flap and double-flap phacoemulsification groups. There were no significant complications.

CONCLUSION

Cataract extraction by phacoemulsification or ECCE combined with IOL implantation and trabeculotomy ab externo is a safe, effective treatment for patients with coexisting glaucoma and cataract.

[Three cases of tuberculous mediastinal lymphadenitis]

Mediastinal lymph node involvement is uncommon in intrathoracic tuberculosis. We report three cases of this disease, each of which had a different clinical course. Chest CT scans showed preferential involvement of right paratracheal nodes, central areas of relatively low density with peripheral rim enhancement after injection of contrast medium. Specimens obtained by mediastinoscopy and fiberoptic bronchoscopy revealed acid-fast bacilli in all cases. In view of its relative frequency, tuberculous mediastinal lymphadenitis in adults must be distinguished from other causes of mediastinal masses.

Assessment of protein kinase C mRNA levels in Alzheimer's disease brains

We have previously demonstrated that the protein level of type beta protein kinase C (PKC) was significantly reduced in Alzheimer's disease (AD) brains compared to controls. To clarify whether this is due to decreased synthesis and/or increased degradation of PKC, the present study was performed to examine mRNA levels of PKC isozymes in control and AD brains. The present study indicated that mRNA levels of types alpha, beta and gamma PKC were not significantly changed in the control and AD brains. Thus, the reduction of type beta PKC protein content in AD brains might be caused by increased degradation.

Identification of the lysyl oxidase gene as target of the antioncogenic transcription factor, IRF-1, and its possible role in tumor suppression

The transcriptional activator IFN regulatory factor 1 (IRF-1) and its antagonistic repressor IRF-2 are regulators of the IFN system. IRF-1 also manifests tumor suppressive activity, and its inactivation could contribute to the development of human hematopoietic malignancies. Here, we report the identification of the lysyl oxidase gene as a target gene of IRF-1. An IRF response element was identified in the lysyl oxidase gene promoter. We also demonstrate that the transformed phenotype of ras-expressing embryonic fibroblasts with a null mutation in the IRF-1 allele could be suppressed by the expression of the lysyl oxidase cDNA, implicating its potential role in tumor suppression. Thus, the regulation of the lysyl oxidase gene by IRF-1 could contribute to the multistep process of malignant transformation.

The precipitate formed by thiopentone and vecuronium

PURPOSE

To determine the composition and solubility of the precipitate formed by thiopentone and vecuronium in vitro.

METHODS

The precipitate formed by mixing thiopentone 2.5% and vecuronium 0.1% at room temperature was analyzed by ultraviolet spectrophotometry and high performance liquid chromatography (HPLC). The solubility of the precipitate in human plasma was measured by HPLC.

RESULTS

The UV absorption spectrum of the precipitate resembled that of thiopentone. HPLC analysis produced a single peak with the same retention time as thiopentone (4.6 min). In human plasma the solubility of the precipitate was not different from that of thiopentone acid. The solubility of thiopentone was greater than that of the precipitate.

CONCLUSION

The precipitate formed by thiopentone and vecuronium in vitro consisted of thiopentone acid, which was insoluble in human plasma.

Concentrations of vascular endothelial growth factor in the sera of normal controls and cancer patients

Vascular endothelial growth factor (VEGF) is known to play crucial roles in tumor angiogenesis. We have investigated the circulating level of VEGF in sera from cancer patients as well as from healthy normal controls using a sensitive enzymatic immunoassay. Immunoreactive VEGF proteins were detectable in normal sera, and the cutoff level was determined to be 180 pg/ml. In examined patients with all types of cancer, including breast, gastrointestinal, hepatobiliary, and lung cancer, an aberrant increase in the circulating level of VEGF was detected. For example, in 137 primary breast cancer patients, 12 (8.8%) showed an aberrant increase in VEGF levels. This aberrant expression of VEGF in sera was significantly associated with the progression of the disease, and with VEGF protein expression in tumor tissues. In addition, a Western blot analysis confirmed the presence of the VEGF165 form in sera from a patient with recurrent breast cancer. It was concluded that VEGF was detectable in normal sera, and its level was increased in some populations of cancer patients. A positive angiogenesis regulator, VEGF might function as an endocrine growth factor, particularly for solid tumors.

Changes of neurocalcin, a calcium-binding protein, in the brain of patients with Alzheimer's disease

We assessed the amount of neurocalcin, a calcium-binding protein, in samples from the postmortem normal human and Alzheimer's disease (AD) brains using a specific antibody. In the AD brains, the amount of neurocalcin in the temporal cortical tissues was significantly lower than that in the controls. Neurocalcin was detected immunohistochemically mainly in the neuropil in the temporal cortex, and its localization was very similar to that of synaptophysin. These findings suggest that reduced levels of neurocalcin reflect a biochemical deficit related to the synaptic degeneration in AD.

[Effects of amosulalol hydrochloride on intraocular pressure and aqueous humor dynamics in the rabbit eye]

The effects of amosulalol, which blocks alpha 1 adrenoceptors selectively and beta receptors nonselectively almost to the same extent, on intraocular pressure (IOP) and aqueous humor dynamics were studied in pigmented rabbits. Administration of topical amosulalol (0.5%) resulted in a significant difference in IOP between the treated and the contralateral eyes from 0.5 to 6 hours, and the maximum IOP reduction, 6.0 +/- 0.4 mmHg (mean +/- standard error), was observed at 2 hours after administration. Aqueous humor dynamics measurements (mean +/- standard error) in the amosulalol (0.5%)-treated and the contralateral eyes revealed that total outflow facility determined by the two-level constant pressure perfusion method was not significantly different, 0.14 +/- 0.01 and 0.12 +/- 0.01 microliter/min/mmHg, respectively; the aqueous flow measurements determined by fluorophotometry were 3.0 +/- 0.1 and 3.4 +/- 0.2 microliters/min, respectively (p < 0.05, -11%); the uveoscleral outflow measurements determined by the fluorescein isothiocyanate-dextran perfusion method were 0.53 +/- 0.04 and 0.46 +/- 0.04 microliter/min, respectively (p < 0.05, +15%). In conclusion, amosulalol lowers the IOP by inhibiting aqueous production and increasing uveoscleral outflow.

Lidocaine attenuates the hypotensive and inflammatory responses to endotoxemia in rabbits

OBJECTIVE

To assess the effects of lidocaine on the hemodynamic and inflammatory responses to Escherichia coli endotoxemia in rabbits.

DESIGN

Prospective, randomized, controlled experimental study.

SETTING

University laboratory.

SUBJECTS

Twenty-seven female Japanese rabbits, anesthetized with urethane and ventilated mechanically.

INTERVENTIONS

Animals were randomly assigned to one of three groups: a) endotoxemic control group (n = 9), receiving intravenous Escherichia coli endotoxin (0.5 mg/kg bolus) via the mesenteric vein; b) laparotomy control group (n = 9), treated identically to the endotoxemic control group, except for substitution of 0.9% saline for endotoxin; and c) lidocaine-treated group (n = 9), treated identically to the endotoxemic controls and additionally, intravenous lidocaine (3 mg/kg bolus, followed by infusion at 2 mg/kg/hr) was administered immediately after endotoxin

MEASUREMENTS AND MAIN RESULTS

We compared hemodynamics, blood gases, and microscopic findings of lung tissue obtained at necropsy in each group. Laparotomy alone had a minimal effect on the parameters and findings. Endotoxin injection decreased mean systolic arterial pressure from 135 +/- 6 (SD) to 95 +/- 25 mm Hg (p < .05) and increased the mean base deficit from -1.2 +/- 1.8 to -14.4 +/- 4.2 mmol/L (p < .05), and caused the infiltration of neutrophils into the lungs. Lidocaine administration abolished the hypotension and attenuated the increase the base deficit to -9.5 +/- 2.1 mmol/L (p < .05) and the cellular infiltration in comparison with endotoxemic controls.

CONCLUSIONS

Lidocaine attenuated the hemodynamic and inflammatory responses to endotoxemia in rabbits. Findings suggest that lidocaine administration may prevent the development of hypotension and metabolic acidosis during endotoxemia.

A novel interferon regulatory factor family transcription factor, ICSAT/Pip/LSIRF, that negatively regulates the activity of interferon-regulated genes

We have isolated a novel cDNA clone encoding interferon (IFN) consensus sequence-binding protein in adult T-cell leukemia cell line or activated T cells (ICSAT); this protein is the human homolog of the recently cloned Pip/LSIRF. ICSAT is structurally most closely related to the previously cloned ICSBP, a member of the IFN regulatory factor (IRF) family of proteins that binds to interferon consensus sequences (ICSs) found in many promoters of the IFN-regulated genes. Among T-cell lines investigated, ICSAT was abundantly expressed in human T-cell leukemia virus type 1 (HTLV-1)-infected T cells. When the HTLV-1 tax gene was expressed or phorbol myristake acetate-A23187 stimulation was used, ICSAT expression was induced in Jurkat cells which otherwise do not express ICSAT. When the binding of ICSAT to four different ICSs was tested, the relative differences in binding affinities for those ICSs were determined. To study the functional role of ICSAT, we performed cotransfection experiments with the human embryonal carcinoma cell line N-Tera2. ICSAT was demonstrated to possess repressive function over the gene activation induced by IFN stimulation or by IRF-1 cotransfection. Such repressive function is similar to that seen in IRF-2 or ICSBP. However, we have found that ICSAT has a different repressive effect from that of IRF-2 or ICSBP in some IFN-responsive reporter constructs. These results suggest that a novel mechanism of gene regulation by "differential repression" is used by multiple members of repressor proteins with different repressive effects on the IFN-responsive genes.

Cholecystokinin-B/gastrin receptors mediate rapid formation of actin stress fibers

Specific receptors for brain-gut peptide hormones, cholecystokinin (CCK) and gastrin, are expressed in a variety of human tumor cells. CCK and gastrin promote the growth of NIH3T3 cells into which the CCK-B/gastrin receptor had been introduced via a eukaryotic expression vector. In this study, we have examined the effect of CCK-8 on the actin cytoskeleton by using two mouse fibroblast cell lines expressing human CCK-B/gastrin receptors. Treatment with very low concentration of CCK-8 (10(-10) M) induced the formation of actin stress fibers within one minute. Stress fiber formation increased for 30 min. In contrast, a potent mitogen for fibroblasts, platelet-derived growth factor (PDGF), initially induced membrane ruffling and, later, a weak formation of stress fibers. Microinjection of rho GDP dissociation inhibitor or Clostridium botulinum ADP-ribosyltransferase C3 which is known to impair the function of a small GTP-binding protein, rho p21, inhibited the stress fiber formation by CCK-8 as well as by PDGF. These results indicate that CCK-B/gastrin receptor could regulate stress fiber formation in a rho p21-dependent manner. The signals from CCK-B/gastrin receptor might affect cell growth as well as cell motility or adhesion by regulating the actin cytoskeleton.

Quantitative analysis of vascular endothelial growth factor in primary breast cancer

BACKGROUND

Recent clinical studies have demonstrated that tumor angiogenesis is a potent prognostic indicator for breast cancer patients. The quantitation of endothelial growth factors is thought to be useful to assess angiogenic phenotype in the tumor. Among the many new endothelial growth factors, vascular endothelial growth factor (VEGF) is known to be particularly responsible for promoting the neovascularization in human breast cancer.

METHODS

Intratumoral protein levels of VEGF were measured by enzymatic immunoassay in 135 primary breast cancer tissues. The VEGF levels were compared with the microvessel density evaluated by immunostaining the endothelial antigen and also were compared with intratumoral protein levels of other endothelial growth factors, including basic fibroblast growth factor (bFGF) and hepatocyte growth factor (HGF).

RESULTS

Intratumoral VEGF concentrations varied from 3.3 pg/mg protein to 2032 pg/mg protein (average 148 pg/mg protein). An immunocytochemical analysis using anti-VEGF antibody confirmed that VEGF was located mainly in the cytoplasm of the tumor cells. The VEGF concentrations were significantly higher in vascularly rich tumors than in vascularly poor tumors. No significant association was found between VEGF concentrations and the two other endothelial growth factor concentrations.

CONCLUSIONS

The quantitation of intratumoral VFGF levels seems to be useful for assessing the activity of tumor angiogenesis.

Somatic overgrowth associated with overexpression of insulin-like growth factor II

Overexpression of the normally imprinted fetal insulin-like growth factor II (IGF2) has been implicated in the pathogenesis of the cancer-predisposing Beckwith-Wiedemann syndrome (BWS). We have detected constitutional relaxation of imprinting of IGF2 in four children with somatic overgrowth who do not show diagnostic features of BWS. Three children showed constitutional abnormalities of H19 methylation. All four children showed nephromegaly and two developed Wilms' tumors. Gene methylation is known to be associated with gene silencing, and three children showed constitutional abnormalities of H19 gene methylation. Disruption of H19 methylation, and concomitant relaxation of IGF2 imprinting, provides another mechanism that can increase IGF2 expression in children with overgrowth. The accumulated data on normal and pathologic IGF2 expression are now sufficient to define an entity, "IGF2 overgrowth disorder," of which BWS may be one extreme manifestation. These findings have broad implications for the characterization of idiopathic overgrowth.

Regulation of endothelial growth factor expressions in breast cancer

Expression of various endothelial growth factors including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), Platelet-derived endothelial cell growth factor (PD-ECGF) and hepatocyte growth factor (HGF) was investigated in human breast carcinoma tissues, and the results were compared to the intratumoral microvessel density evaluated by the immunostaining to anti-factor VIII related antigen. VEGF and PD-ECGF were examined by immunostainings, and bFGF and HGF were assessed by enzymatic immunoassays. As a result, VEGF and PD-ECGF were significantly associated with the increment of microvessel density, although no significant correlation was found with bFGF and HGF. In addition, interestingly, a tendency of co-expression between VEGF and PD-ECGF was demonstrated. It was suggested that VEGF and PD-ECGF play important roles in the promotion of angiogenesis in human breast cancer.

[Effects of prostaglandin E1 on plasma cytokine levels during pneumonectomy]

We investigated the effect of prostaglandin E1 (PGE1) on intraoperative cytokine responses and the incidence of postoperative complications. Twenty-six patients undergoing elective pneumonectomy were randomly allocated into PGE1 group (n = 12) and control group (n = 14). The PGE1 group received continuous infusion of PGE1 during surgery at a dose of 0.02-0.03 microgram.kg-1.min-1. Blood samples were obtained after induction of general anesthesia, one and two hours after incision, and immediately after the end of surgery to measure the plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8). Levels of CRP for two days after the surgery were measured and postoperative complications were recorded. Levels of TNF-alpha rose from 1.6 pg.ml-1 (mean) to 4.8 pg.ml-1 two hr after incision in the control group, while the level was suppressed in the PGE1 group (P < 0.05). No significant difference was found in IL-6 levels between the two groups. The IL-8 increased during surgery in both groups but the increase was significantly less in the PGE1 group (P < 0.05). There was no difference in CRP, and no severe postoperative complication was observed. We conclude that PGE1 administration suppresses TNF-alpha and IL-8 responses during pneumonectomy, but its effects on IL-6 and the postoperative status were not significant.

Effects of lipoprotein(a) and low density lipoprotein on growth of mitogen-stimulated human umbilical vein endothelial cells

We investigated the effects of lipoprotein(a) (Lp(a)) and low density lipoprotein (LDL) on proliferation of human umbilical vein endothelial cells (HUVECs). Both Lp(a) and LDL stimulated the growth of HUVECs synergistically with basic fibroblast growth factor and insulin in a dose-dependent manner. The potency of Lp(a) to promote the cell proliferation was 40% less than that of LDL. Addition of anti-transforming growth factor-beta 1 neutralizing antibody into the medium could not diminish the difference of HUVECs proliferation by Lp(a) and LDL. However, addition of anti-LDL receptor antibody suppressed HUVECs proliferation to the same level and sequestered the difference by the two lipoproteins. Moreover, cholesteryl ester content incubated with Lp(a) was 50% less than that with LDL. These results suggest that Lp(a) has less effect on HUVECs proliferation and cholesterol delivery to the cells than LDL. Therefore, Lp(a) may play a role as an atherogenic lipoprotein by delaying the repair of endothelium after injury.