Cooperation of the tumour suppressors IRF-1 and p53 in response to DNA damage

Normally growing cells promptly cease DNA synthesis when exposed to genotoxic stresses, such as radiation, and this cell-cycle arrest prevents the accumulation of mutations. The transcription factor interferon regulatory factor (IRF)-1 is essential for the regulation of the interferon system, inhibits cell growth, and manifests tumour-suppressor activities. Here we show that mouse embryonic fibroblasts (EFs) lacking IRF-1 are deficient in their ability to undergo DNA-damage-induced cell-cycle arrest. A similar phenotype has been observed in EFs lacking the tumour suppressor p53 (refs 8, 9), although the expression of IRF-1 and p53 are independent of one another. Furthermore, we show that transcriptional induction of the gene encoding p21 (WAF1, CIP1), a cell-cycle inhibitor, by gamma-irradiation is dependent on both p53 and IRF-1, and that the p21 promoter is activated, either directly or indirectly, by both in a transient cotransfection assay. These two tumour-suppressor transcription factors therefore converge functionally to regulate the cell cycle through the activation of a common target gene.

[Surgical treatment of pericostal tuberculosis]

The following two points must be considered on treating pericostal tuberculosis: the first is the appropriate time to treat pericostal tuberculosis surgically when the medical therapy fails to induce a remission, and the second is how to prevent postoperative relapse. In the present study, we investigated these two points by examining seven patients who underwent surgery at the department of thoracic surgery (Osaka Red Cross Hospital), during a 10 years period from January 1985 to December 1994. Antituberculotics were administered to these patients for an average of 3.9 months before surgery, but in vain. Therefore, they were surgically treated. In all cases, the incision was closed at once, and there were no severe complications. The signs and symptoms disappeared soon after surgery. It has been reported that the medical treatment leads to recovery or tendency to recovery within three months of drug administration. The conditions of pericostal tuberculosis patients during this period can be used as indicators to decide whether or not to carry out surgical treatment. Also, by active excision of the rib and tumor as one mass, and by administering antituberculotic for 13.1 months after surgery, no relapse took place during the follow-up period (average 37.4 months). And the postoperative respiratory functions did not decrease compared to those before surgery.

Epithelial barrier function of the filtering bleb conjunctiva and the cornea after trabeculectomy with mitomycin C

PURPOSE

To evaluate epithelial barrier function of the filtering bleb conjunctiva and the cornea after trabeculectomy with adjunct, intraoperative mitomycin C, by using a newly developed slit-lamp fluorophotometer.

SUBJECTS AND METHODS

Thirteen patients with normal-tension glaucoma with a cystic filtering bleb who had undergone unilateral trabeculectomy with mitomycin C only once at least 1 year previously were subjected to the study. Epithelial barrier function of the bleb conjunctiva and the cornea in the operated eye was evaluated using an Anterior Fluorometer FL-500 to measure the uptake of topically applied fluorescein.

RESULTS

Fluorescein uptake (nanograms per milliliter, mean +/- standard error) by the bleb conjunctiva (1,857 +/- 380) was not significantly different from either the uptake by the superior bulbar conjunctiva in the operated eyes, located approximately 90 degrees C away from the filtering bleb (1,974 +/- 258), or the uptake by the conjunctiva in the intact eyes, located symmetrically against the bleb (1,913 +/- 248). The corneal uptake in the operated eye (56.1 +/- 10.2) was not significantly different from that in the intact eye (53.5 +/- 8.3).

CONCLUSIONS

Epithelial barrier function of the cystic filtering bleb conjunctiva and the cornea long after trabeculectomy with mitomycin C was demonstrated to be almost identical to that of the control.

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.

Ca2+-dependent and Ca2+-independent protein kinase C changes in the brain of patients with Alzheimer's disease

We examined protein kinase C (PKC) activity in Ca2+-dependent PKC (Ca2+-dependent PKC activities) and Ca2+-independent PKC (Ca2+-independent PKC activities) assay conditions in brains from Alzheimer's disease (AD) patients and age-matched controls. In cytosolic and membranous fractions, Ca2+-dependent and Ca2+-independent PKC activities were significantly lower in AD brain than in control brain. In particular, reduction of Ca2+-independent PKC activity in the membranous fraction of AD brain was most enhanced when cardiolipin, the optimal stimulator of PKC-epsilon, was used in the assay; whereas Ca2+-independent PKC activity stimulated by phosphatidylinositol, the optimal stimulator of PKC-delta, was not significantly reduced in AD. Further studies on the protein levels of Ca2+-independent PKC-delta, PKC-epsilon and PKC-zeta in AD brain revealed reduction of the PKC-epsilon level in both cytosolic and membranous fractions, although PKC-delta and PKC-zeta levels were not changed. These findings indicated that Ca2+-dependent and Ca2+-independent PKC are changed in AD, and that among Ca2+-independent PKC isozymes, the alteration of PKC-epsilon is a specific event in AD brain, suggesting its crucial role in AD pathophysiology.

Influence of oocyte aging on developmental ability of reconstituted embryos produced from oocyte cytoplast and single blastomeres of two-cell stage embryos

The present study was conducted to investigate the influence of aging of recipient oocyte on the developmental ability of reconstituted mouse embryos produced from the cytoplast of oocytes and single blastomeres of early or late 2-cell stage embryos by electrofusion. Oocytes were obtained at 14 (newly ovulated oocytes), 18, 22 (oocyte that time passed after ovulation; aged oocyte) hr after hCG injection and oocyte cytoplast was produced by manual enucleation using a fine glass needle under the dissecting microscope. The aging of the oocytes significantly influenced on the fusion rate of the reconstituted embryos (14 hr: 42.7-47.2% vs. 22 hr: 75.3-77.6%). Similarly, the cleavage rate of reconstituted embryos increased with aging of the oocytes (14 hr: 50.8-56.3% vs. 22 hr: 82.2-90.7%). The percentage of reconstituted embryos produced from cytoplast of aged oocytes (22 hr post hCG) and single blastomeres of late 2-cell stage embryos developing to the blastocyst (20.8%) was significantly higher than that of reconstituted embryos produced by other combinations (2.0-8.2%: P < 0.01). Although cell cycle stage of donor nuclei influenced to developmental ability of reconstituted embryos, these results are probably related to the aging of the oocytes since aged oocytes can be activated more easily by electrical stimulation than newly ovulated oocytes.

Antiproliferative effect of a novel cholecystokinin-B/gastrin receptor antagonist, YM022

Cholecystokinin (CCK)-B and gastrin receptors are expressed on a variety of human tumor cells. Recently, we have demonstrated that the human brain CCK-B receptors are identical to the gastrin receptors derived from the stomach mucosa, and that the brain-gut peptides, CCK-8 and gastrin I are mitogenic for mouse NIH 3T3 fibroblasts expressing human CCK-B/gastrin receptors (N-hCCKBR). In this report, we evaluated the antiproliferative potency of CCK-B/gastrin receptor antagonists by using N-hCCKBR cells. Among several antagonists, a benzodiazepine derivative, YM022 had the most potent activities in competing with [125I]CCK-8 or [125I]gastrin I binding, inhibition of CCK-8- or gastrin I-induced phosphoinositide hydrolysis and increasing cytoplasmic free calcium. Interestingly, a potent antagonist for rat CCK-B/gastrin receptors did not have such activities in N-hCCKBR cells. YM022 inhibited the CCK-8- or gastrin I-induced [methyl-3H]thymidine incorporation of N-hCCKBR cells in a dose-dependent manner. In the absence of exogenous peptide ligands, YM022 also inhibited the proliferation of several human cancer cell lines expressing the genes for both gastrin and its receptor. These results suggest that YM022 could intervene in the autocrine stimulation of human tumor cell lines through CCK-B/gastrin receptors. N-hCCKBR cells are an excellent tool to screen for novel human CCK-B/gastrin receptor antagonists possessing antiproliferative activity for human cancer cells.

Expression of apolipoprotein E mRNA in rat microglia

Apolipoprotein E (apoE) is a major risk factor for Alzheimer disease (AD), which is the most common cause of progressive dementing illness. ApoE has been postulated to be synthesized by astrocytes and taken up by microglia and neuronal cells. However, it remains unknown whether apoE is also produced by microglia in the brain. We analyzed apoE mRNA expression of microglia using a rat primary culture system. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed expression of apoE mRNA in cultured rat microglia. By RT-in situ-PCR, microglia showed positive staining for the PCR product of apoE mRNA. These results indicated that apoE was biosynthesized in rat microglia. We suggest that microglia might be one of the sources of apoE in the brain, and that apoE synthesized in microglia might be closely related to the pathogenesis of AD.

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.