Identification and characterization of novel genotoxic stress-inducible nuclear long noncoding RNAs in mammalian cells

Whole transcriptome analyses have revealed a large number of novel transcripts including long and short noncoding RNAs (ncRNAs). Currently, there is great interest in characterizing the functions of the different classes of ncRNAs and their relevance to cellular processes. In particular, nuclear long ncRNAs may be involved in controlling various aspects of biological regulation, such as stress responses. By a combination of bioinformatic and experimental approaches, we identified 25 novel nuclear long ncRNAs from 6,088,565 full-length human cDNA sequences. Some nuclear long ncRNAs were conserved among vertebrates, whereas others were found only among primates. Expression profiling of the nuclear long ncRNAs in human tissues revealed that most were expressed ubiquitously. A subset of the identified nuclear long ncRNAs was induced by the genotoxic agents mitomycin C or doxorubicin, in HeLa Tet-off cells. There were no commonly altered nuclear long ncRNAs between mitomycin C- and doxorubicin-treated cells. These results suggest that distinct sets of nuclear long ncRNAs play roles in cellular defense mechanisms against specific genotoxic agents, and that particular long ncRNAs have the potential to be surrogate indicators of a specific cell stress.

LKB1, TP16, EGFR, and KRAS somatic mutations in lung adenocarcinomas from a Chiba Prefecture, Japan cohort

The discovery of somatic mutations in cancer-related genes has been applied to understand the genetic basis of cancer. Here we report somatic mutations of two tumor suppressor genes: LKB1 (exons 1, 4, and 8) and TP16 (CDKN2A) (exons 1 and 2); and two oncogenes: epidermal growth factor receptor EGFR (exons 18-21) and KRAS (exon 2) in 97 lung adenocarcinoma tissues in a cohort from the Kujukuri coast area of Chiba, Japan. In the LKB1 gene, only F354L substitutions were observed in 14 of the 97 tissue samples (14.4%). In the TP16 gene, only two deletions were observed in contrast to previous reports. On the other hand, the EGFR gene was highly mutated (38.1%) and mainly L858R substitutions occurred (23.7%) as well as insertions and deletions. In the KRAS gene, 10 substitutions at codon 12 were observed (10.3%). Co-occurrence of EGFR and KRAS somatic mutations was identified in one patient, those of EGFR and LKB1 were in three patients, and those of KRAS and LKB1 were in four patients. The lower rates of LKB1, TP16, and KRAS somatic mutations in lung adenocarcinomas are characteristic of the Kujukuri cohort as compared to Caucasians.

Mechanism for Covalent Binding of Rofecoxib to Elastin of Rat Aorta

We have previously reported that oral administration of [(14)C]rofecoxib to rats resulted in the long retention of radioactivity by the aorta as a consequence of covalent binding to elastin. Treatment of rats with alpha-phenyl-alpha-propylbenzeneacetic acid 2-[diethylamino]-ethyl ester hydrochloride (SKF-525A), a cytochrome P450 inhibitor, significantly decreased the systemic exposure of 5-hydroxyrofecoxib, one of the main metabolites of rofecoxib, whereas there was no statistically significant change in the retention of radioactivity from [(14)C]rofecoxib in the aorta. On the other hand, the aortic retention of radioactivity closely correlated to the systemic exposure of unchanged rofecoxib in the dose range between 2 and 10 mg/kg. A covalent binding study of [(14)C]rofecoxib in vitro using rat aorta homogenate in the presence of d-penicillamine, hydralazine, beta-aminopropionitrile, and sodium borohydride suggested that the aldehyde group of allysine in elastin was relevant to the covalent binding. In a model reaction using benzaldehyde, rofecoxib but not 5-hydroxyrofecoxib reacted with the aldehyde group of benzaldehyde in a manner of condensation reaction under a physiological pH condition. A histopathological examination using an electron microscope demonstrated that multiple oral administration of rofecoxib to rats caused marked degradation of the elastic fiber system of the aorta. These results suggested that rofecoxib as such is reactive in vivo, undergoing a condensation reaction with allysine, thereby preventing the formation of cross-linkages in elastin, i.e., desmosine and isodesmosine, and causing the degradation of the elastic fibers.

Ethanol improves decreased filterability of human red blood cells through modulation of intracellular signaling pathways

BACKGROUND

Deformability of red blood cells (RBCs) is one of the most important factors in maintaining the microcirculation system. In vitro studies have revealed that ethanol seriously impairs the deformability of RBCs at concentrations far higher than those easily achievable in the blood after alcohol consumption. We examined the effect of ethanol on deformability at the physiologically achievable concentrations.

METHODS

To impair deformability quantitatively, washed RBCs from healthy young male volunteers were mechanically stressed by being injected rapidly through a fine needle. The deformability of RBCs was evaluated by measuring the filterability through a nickel mesh filter. The activities of protein kinase A and protein kinase C in RBCs were measured by the ELISA method using an antibody for the phosphorylated substrate of the kinases.

RESULTS

Ethanol exhibited a biphasic effect on the mechanically impaired filterability of human RBCs, that is, an improvement at concentrations from 0.02% to 0.2% (v/v) and a marked deterioration at 0.5% and higher. Without mechanical stress, ethanol decreased filterability at concentrations of 0.5% and higher. Ethanol increased the protein kinase A and protein kinase C activities of the mechanically stressed RBCs at concentrations of 0.02% and higher and those of the RBCs without mechanical stress at concentrations of 0.05% and higher.

CONCLUSIONS

The present results suggest a beneficial effect of ethanol on blood rheology at concentrations that are physiologically achievable in the blood and indicate the importance of intracellular signaling pathways in regulating the deformability of RBCs.

Endothelin-1 improves the impaired filterability of red blood cells through the activation of protein kinase C

We previously showed that the deformability of human red blood cells (RBCs) is affected by intracellular signaling pathways by examining the effects of Ca2+ influx and the intracellular cAMP level on mechanically-impaired RBC filterability. In the present study, we investigated whether protein kinase C (PKC) participates in the regulation of RBC deformability by affecting membrane properties. The filterability of mechanically-stressed RBCs showed a V-shaped curve depending on the extracellular Ca2+ concentration; the maximum decrease was achieved at 20-40 microM. The PKC activity, as measured in the membrane-rich fraction by an ELISA method using an antibody for the phosphorylated PKC substrate, maximally increased at the extracellular Ca2+ concentration where the filterability showed a marked improvement following the bottom of the V-shaped curve of the impaired filterability. At this Ca2+ concentration, the PKC activator endothelin-1 increased the PKC activity, and a PKC inhibitor (calphostin C) decreased it. Endothelin-1 improved and calphostin C worsened the impaired filterability. A specific type-B endothelin receptor agonist (IRL 1620) also improved the impaired filterability. A Western blot analysis revealed the presence of endothelin receptors in the RBC membrane. These results indicate that PKC improves the impaired filterability and that RBCs are the target of endothelin-1.

Kinetic analysis of the mechanism of action of the multidrug transporter

To clarify the mechanistic role of PGP (P-glycoprotein) in multidrug transport, we constructed a kinetic model composed of four compartments: (1) the extracellular space; (2) the space in the membrane; (3) the intracellular space; and (4) the pore-like space in the PGP molecule. The kinetics of the concentration of ADM (adriamycin) in each compartment were formulated based on the assumptions that (a) the movement of ADM between two compartments by diffusion is dependent on a dynamic distribution coefficient introduced here, (b) the uptake of ADM into the pore-like structure by the pump mechanism activated by ATP is described by enzyme kinetics, (c) the movement of ADM out of the pore-like structure to the extracellular medium through a valve-like mechanism is also expressed by enzyme kinetics. The mathematical analysis of the exact solution can explain the distinct effects of verapamil and vanadate on the accumulation and release of ADM, where verapamil inhibits the efflux by the valve-like mechanism and vanadate blocks the influx by the pump mechanism. We also performed a numerical calculation with this model for a quantitative explanation and found the valid parameter values to fit the experimental data. These results support the modified hydrophobic vacuum cleaner model.

Production of prostaglandins E1 and E2 by adult human red blood cells

We showed that human adult red blood cells (RBCs) produce prostaglandin E1 (PGE1) and E2 (PGE2). RBCs that were mechanically stressed in the presence of extracellular Ca2+ by being injected rapidly through a fine needle produced PGE1 and PGE2 within 30 min after this mechanical stress. The amounts of PGE1 and PGE2 produced by 1 x 10(9) mechanically stressed RBCs were approximately 50 pg and 100 pg, respectively, which were determined in the cytosolic fraction from sonicated RBCs using a competitive enzyme immunoassay method. A Western blot analysis using anti-cyclooxygenase-2 antibody revealed a band at the 70-kDa position in the samples from RBCs producing PGE1 and PGE2. Treatment with 10 micrograms/mL indomethacin completely inhibited the productions of PGE1 and PGE2. The present results may indicate a new role of RBCs in microcirculation.

Regulation of red blood cell filterability by Ca2+ influx and cAMP-mediated signaling pathways

To investigate the mechanism of the regulation of human red blood cell deformability, we examined the deformability under mechanical stress. Washed human red blood cells were rapidly injected through a fine needle, and their filterability was measured using a nickel mesh filter. The decrease in filterability showed a V-shaped curve depending on the extracellular Ca2+ concentration; the maximum decrease was achieved at approximately 50 muM. The decreased filterability was accompanied by no change in cell morphology and cell volume, indicating that the decrease in filterability can be ascribed to alterations of the membrane properties. Ca2+ entry blockers (nifedipine and felodipine) inhibited the impairment of filterability under mechanical stress. Prostaglandins E1 and E2, epinephrine, and pentoxifylline, which are thought to modulate the intracellular adenosine 3',5'-cyclic monophosphate (cAMP) level of red blood cells, improved or worsened the impaired filterability according to their expected actions on the cAMP level of the cells. These results strongly suggest that the membrane properties regulating red blood cell deformability are affected by the signal transduction system, including Ca(2+)-dependent and cAMP-mediated signaling pathways.

In vivo and in vitro evaluation of the pulsatile mode of a magnetically suspended centrifugal pump

The authors have been developing a magnetically suspended centrifugal pump (MSCP). They have devised a pulsatile mode for the MSCP, which was generated by altering rotational speed. This article describes in vitro and in vivo studies with the pulsatile mode of the MSCP. Hemolysis tests were performed in two identical circuits to compare the nonpulsatile (NP) mode and the pulsatile (P) mode. In vivo studies were performed in sheep. First, biventricular assisted circulation was instituted in the left heart with the MSCP and in the right heart with the Biopump. The native heart was induced to ventricular fibrillation. Second, a left ventricular assisted circulation was instituted as the native heart was beating. An inflow cannula was inserted into the left atrium in one sheep and into the left ventricle in the other. The normalized indices of hemolysis of the NP and P groups were 0.0025 +/- 0.0018 g/100 L, and 0.0032 +/- 0.0024 g/100 L (N = 4, not significant). During ventricular fibrillation in the P mode, the pulse pressure was 14 mmHg (the rotational speed: 1,500 to 2,600 rpm). In a beating heart, at atrial withdrawal, the pulse pressure increased from 10 to 24 mmHg (2,100 +/- 500 rpm), while at ventricular withdrawal, it decreased from 17 to 40 mmHg (2,000 +/- 500 rpm) on P mode. The MSCP in pulsatile mode did not increase hemolysis. At ventricular withdrawal, it was easier to produce a pulsation than at atrial withdrawal. The pulsatile mode of the MSCP is applicable to a left ventricular assist system.

Biomechanical analysis of buckling alignment of the cervical spine. Predictive value for subaxial subluxation after occipitocervical fusion

STUDY DESIGN

A biomechanical analysis of the buckling type of alignment on nonfused cervical segments was carried out in patients with occipitocervical fusion for atlantoaxial dislocation.

OBJECTIVES

To examine whether biomechanical analysis is useful for preoperative prediction of subaxial subluxation after occipitocervical fusion.

SUMMARY OF BACKGROUND DATA

Rheumatoid arthritis sometimes causes subaxial subluxation after occipitocervical fusion. At present, there are no widely accepted criteria for determining the appropriate extent of fusion to prevent subluxation.

METHODS

The subjects were 25 patients with rheumatoid atlantoaxial dislocation and 15 patients with nonrheumatoid atlantoaxial dislocation who underwent occipitocervical fusion. Preoperative and postoperative alignment of the cervical spine were analyzed biomechanically, using a specially developed computer program.

RESULTS

Five segments of nonfused cervical spine had subluxation after surgery in the rheumatoid group. For these segments, the preoperative value of buckling averaged 13.5 x 10(-4) and exceeded 10 x 10(-4) in all cases. For the segments that showed no subluxation after surgery, the preoperative value of buckling averaged 4.5 x 10(-4). Subluxation of the nonfused segments did not develop in the nonrheumatoid group.

CONCLUSIONS

In patients with rheumatoid arthritis, segments that show abnormal buckling before surgery are likely to develop subluxation after occipitocervical fusion. Preoperative values of buckling over 10 x 10(-4) constitute a risk factor for subaxial subluxation after occipitocervical fusion.

Quantitative characterization of P-glycoprotein-mediated transport in mdr1-gene-transfected lymphoma cells

We have established a quantitative flow cytometry system to elucidate the causal role of P-glycoprotein in the phenomenon of multidrug resistance. We have used this method to analyze the accumulation and release of adriamycin (ADM) in intact L5178Y and L5178Y/VMDR/C.06 (L5178Y/R) cells, by determining the effect of sodium orthovanadate (Na3VO4), verapamil, bovine serum albumin (BSA) and physiologically operative materials on the cells. Based on the experiments, we prepared a standard solution that contained NaCl, D-glucose, L-cysteine, HCO3- and BSA, which was sufficient to perform transport experiments. In particular, BSA caused a decrease in ADM accumulation and a facilitation of the rate of ADM release in both L5178Y and L5178Y/R cells, probably due to its relatively high affinity for ADM as compared to the cell membrane. In multidrug-resistant L5178Y/R cells, sodium orthovanadate, a strong ATP-binding inhibitor, caused a marked increase in the accumulation of ADM, whereas vanadate-treated drug-sensitive L5178Y cells showed little increase in ADM accumulation. In a release (0-trans exit) experiment, vanadate-treated L5178Y/R cells exhibited an apparent decrease in ADM release (increase in ADM retention), to a level which was almost the same as L5178Y cells. We thus confirmed that the P-glycoprotein-mediated efflux system is coupled with P-glycoprotein-associated ATP-hydrolysis. Further, verapamil, a potent inhibitor of P-glycoprotein-mediated transport, facilitated the ADM accumulation in L5178Y/R cells up to the level of L5178Y and vanadate-treated L5178Y/R cells. A more important finding is that, in the release experiment, verapamil-treated L5178Y/R cells exhibited a much greater ADM retention than drug-sensitive L5178Y and vanadate-treated L5178Y/R cells. These findings, in particular the potent effect of verapamil on drug-resistant cells, may afford new insight into the pathophysiology of the phenomenon of multidrug resistance and the mechanism of action of the multidrug transporter.

[TSH-secreting fibrous pituitary adenoma showing calcification: a case report]

TSH-secreting pituitary adenoma with calcification and proliferation of the collagen fibers was presented. A 42-year-old man had shown general fatigue and thyroid hypertrophy caused by hyperthyroidism for 3 years. CT and MRI revealed pituitary adenoma with calcification extending into the cavernous sinus and sphenoid sinus. The patient was operated on using the transsphenoidal route twice, but the tumor was not able to be removed totally, partly due to the hardness of the tumor. The tumor in- and around the left cavernous sinus as well as the hardest part of the tumor itself due to the calcification could not be removed. Histopathological examination revealed chromophobe adenoma with proliferation of the collagen fibers. Immunohistological and electronmicroscopic examination demonstrated TSH-secreting adenoma. Postoperatively, thyroid function improved and the patient's symptoms due to hyperthyroidism disappeared.

Mesothelial cyst of the adrenal gland

A case of mesothelium-lined cyst of the adrenal gland is reported. Although more than 300 adrenal cysts have been reported in the literature, epithelial cell-lined cysts are rare and comprise only 9% of the cases. An adrenal cyst was found, the lining cells of which had features consistent with mesothelial cells. The inner surface of the cyst was lined by a single layer of cuboidal cells, which showed alcian blue positive cellular outline. Immunohistochemically, the lining cells were positively stained for keratin, epithelial membrane antigen and CA-125. Electron microscopic examination revealed many long complex microvilli and desmosomes in the lining cells. There was a basal lamina beneath the cell layer. These morphological and immunohistochemical findings indicated that the lining cell is derived from mesothelium.

Regression of left ventricular hypertrophy with long-term treatment of nifedipine in systemic hypertension

We investigated the regression of left ventricular (LV) hypertrophy with long-term treatment of nifedipine in patients with systemic hypertension. Echocardiograms of the LV were obtained in nine patients before and at a mean of 50 months (13-105 months) after nifedipine monotherapy (30-60 mg/day). Nifedipine significantly reduced both systolic and diastolic blood pressures (BP) by a mean of -46 mmHg and -21 mmHg, respectively. With systemic BP reduction, LV mass was significantly reduced by a mean of -15%, associated with a decrease in LV posterior wall thickness and end-diastolic dimension. There was no significant change in LV fractional shortening. We conclude that nifedipine may cause regression of LV hypertrophy in systemic hypertension, and that reversal of the increase in LV mass could be maintained during long-term nifedipine treatment.

Development of acute myocardial infarction associated with coronary collateral regression after reperfusion by percutaneous transluminal coronary angioplasty

Clinical and experimental observations have suggested that newly developed collaterals usually remain even after successful revascularization. We present a patient in whom coronary collateral regression was angiographically demonstrated within about 1 month after percutaneous transluminal coronary angioplasty, which led to the development of acute myocardial infarction. This case suggests that there may be a possibility of unexplained clinically important anatomical or functional regression of collaterals after reperfusion.

Methods for detection of MDR1 mRNA expression on acute myelogenous leukemia cells

Overexpression of the human multidrug resistance gene (MDR1) on acute myelogenous leukemia (AML) correlates with poor prognosis. We evaluated several methods for mRNA estimation to standardize simple and reliable techniques for identifying MDR1 positive leukemia among untreated AMLs in large scale studies. Northern blot detection of MDR1 mRNA suffered from low signal-to-noise ratio under the conventional conditions, that was improved mainly by removing unincorporated radioactivity. The amount of MDR1 transcripts on positive cells was estimated less than 10% of that of constitutive mRNA species. A modified method seemed useful in estimating the total amount of the MDR1 mRNA in a whole leukemic cell population, and suitable to study stock samples or for large prospective clinical trials. RT-PCR was more sensitive in detecting MDR1 mRNA than Northern blot analysis, and the very feature made it virtually impossible to exclude contamination with normal hematopoietic cells. This procedure showed that FAB M3 leukemias were essentially MDR1 negative, and there existed frequently myelodysplastic syndrome subpopulation which had excessive MDR1 transcripts. In situ hybridization of the mRNA with a FITC-labeled phosphorothioate oligonucleotide probe was visualized using flowcytometry or con-focus lightmicroscopy, enabled us to recognize the difference between multidrug resistant K562/ADM and its wild type.

Flow cytometric studies of the binding of monoclonal antibodies OKT3, OKT4 and OKT8

The binding of monoclonal antibodies (OKT3, OKT4 and OKT8) to human T cells was investigated by flow cytometry. A flow cytometer was calibrated with standard fluorescence microspheres, which permitted quantitation of the number of bound antibody molecules. Considerable care was taken to perform the flow cytometric assay at a constant temperature and the effect of temperature on the binding reaction was examined. The binding of OKT3, OKT4 and OKT8 exhibited saturation kinetics. The maximum binding varied with temperature. Kinetic analysis according to the Hill equation revealed that the value of the Hill coefficient for OKT3 changed from 1.8 to 1.0 when the temperature was raised from 12 degrees C to 36 degrees C, whereas the corresponding values for OKT4 and OKT8 did not vary with temperature. Thermodynamic functions obtained from the Van't Hoff plot showed that the binding of OKT3 was exothermic whereas the binding of OKT4 and OKT8 were endothermic.

A new standard fluorescence microsphere for quantitative flow cytometry

A standard fluorescence microsphere has been prepared for quantitative flow cytometry. A uniformly sized (6.53 +/- 0.34 micron in diameter) and perfectly spherical plastic microsphere, Micropearl-FT, was covalently conjugated with fluorescein isothiocyanate (FITC). The characteristic of this microsphere to lyse completely in strong alkaline solutions made it possible to determine the amount of bound FITC easily and reproducibly. The amount of bound FITC depended on the concentration of FITC and the incubation time at pH 9.5 and 37 degrees C. In flow cytometry, the fluorescence intensity of the FITC-conjugated microsphere (FCMS) showed linear dependence on the amount of bound FITC. The fluorescence intensity of FCMS was stable for at least 3 months even in aqueous solutions. Using FCMS, an Epics V was calibrated and the minimum measurable fluorescence intensity was examined. From analysis using this system, the number of FITC-conjugated OKT3 molecules bound to human T lymphocytes was shown to average 4.4 X 10(4) per cell at saturation.

Mesangiolysis in the glomerular lesion of cyanotic congenital heart disease

Mesangiolysis associated with glomerulomegaly was observed in an autopsy case of an 11-year-old boy with cyanotic congenital heart disease, i.e. complete transposition of the great vessels with large VSD. Microscopical examination of the kidney revealed marked enlargement of glomeruli with mesangiolysis mainly found in the midzonal cortex involving 16 to 20% of all glomeruli. The glomerular basement membrane in the mesangiolytic lesion showed splitting, between which red blood cells were occasionally encountered. By reconstruction study with serial sectioning, the mesangiolysis was observed to be obviously focal and segmental. Immunofluorescent study revealed no positive results for IgG, IgA, IgM, C3, and fibrinogen/fibrin. By electron microscopic study on the post formalin fixed specimens, no remarkable dense deposits were found in any structural components of the glomeruli. It was assumed that the mesangiolysis might have been provoked by some circulatory disturbances, which superimposed on the preexisting glomerular lesion of cyanotic congenital heart disease in the terminal stage of the clinical course.

Pachymeningitis cervicalis hypertrophica

Presented here is an autopsy case of pachymeningitis cervicalis hypertrophica. A 77-year-old female had the initial symptoms of cervical radiculopathy which terminated in the syndrome of spinal cord transection. Prior to the onset of radiculopathy, the patient had been admitted to the hospital because of a fever and had been shown to have granulomatous sinusitis. Autopsy revealed chronic granulomatous pachymeningitis of the cervical spinal cord, the lesion being mostly restricted to this region. From histopathologic similarities, the extension of sinusitis to cervical pachymeningitis was assumed, but this was not confirmed. An attempt to discover the causative micro-organisms was unsuccessful. The possibility of a limited form of Wegener's granulomatosis could be excluded in view of the absence of true angiitis. Corresponding to the levels of pachymeningitis, the spinal cord was also severely damaged, which was principally due to circulatory disturbance as a result of pachymeningitis.

Allergic granulomatosis and angiitis (Churg-Strauss)

An autopsy case of allergic granulomatosis and angiitis of Churg and Strauss is presented. The patient with a history of bronchial asthma of 3 years duration, a mild fever and hypereosinophilia, died in status asthmaticus. Cortocosteroid therapy was not given. The autopsy revealed severe eosinophilic pneumonia, disseminated necrotizing vasculitis of small arteries and veins in various stages, and extravascular granulomatous nodules. The involved organs were the lungs, liver and gastrointestinal tract, but the heart and kidneys were free from these lesions. The differences from the reported cases were discussed.