Manganese superoxide dismutase expression correlates with p53 status and local recurrence of cervical carcinoma treated with radiation therapy

Manganese superoxide dismutase (Mn-SOD) inactivates the radiation effect by removal of radiation-induced toxic superoxide radicals. The purpose of this study was to assess the correlation among Mn-SOD, radiation sensitivity, and prognosis following radiation therapy. The Mn-SOD, p53 oncoprotein, and c-erbB-2 oncoprotein expressions in 52 specimens from patients with cervical cancer treated with radiation therapy were investigated immunohistochemically. The frozen sections were stained using antihuman Mn-SOD, anti-p53 monoclonal antibodies, and anti-c-erbB-2 oncoprotein polyclonal antibody followed by the avidin-biotin peroxidase complex method. Correlations among Mn-SOD expression, prognosis, and failure patterns were analyzed. Additionally, correlations between p53 and c-erbB-2 oncoproteins and Mn-SOD expression were investigated. Positive expression of Mn-SOD in cervical carcinoma was 48.1%. No significant difference in positivity of Mn-SOD expression was noted according to stage and histological subtypes. The 5-year survival rate of Mn-SOD-positive patients was 42.5 %, significantly poorer than the 77.0% of Mn-SOD-negative patients (P < 0.05). Analysis of the failure patterns revealed that patients with Mn-SOD expression showed a significantly higher incidence of local recurrence than those without. However, there was no difference in distant metastasis between them. Although both p53 and c-erbB-2 oncoprotein expressions were significantly associated with the prognosis of the same patients, Mn-SOD expression was associated with p53 oncoprotein expression but not with that of c-erbB-2 oncoprotein. Our results demonstrate that the Mn-SOD level of cancer cells is correlated with local control and is an important prognostic factor in radiation therapy for cervical cancer. The Mn-SOD level may help explain the intrinsic radiosensitivity of cervical cancer cells.

A new cytotoxic cholestane bisdesmoside from Ornithogalum saundersiae bulbs

Bioassay-guided fractionation of the MeOH extract of Ornithogalum saundersiae bulbs led to the isolation of a new cholestane bisdesmoside with potent cytotoxic activities toward leukemia HL-60 and MOLT-4 cells. The structure was deduced mainly from spectroscopic information.

Analysis of response to radiation therapy of patients with cervical adenocarcinoma compared with squamous cell carcinoma. MIB-1 and PC10 labeling indices

BACKGROUND

The MIB-1 monoclonal antibody is a marker of cycling cells and the PC10 monoclonal antibody is a marker of proliferating cell nuclear antigen in paraffin sections. This study was conducted to elucidate the difference in response to radiotherapy (RT) between cervical adenocarcinomas and squamous cell carcinomas, focusing on cell proliferation.

METHODS

A total of 196 biopsy specimens taken from the cervical carcinomas of 14 consecutive patients with adenocarcinoma and 62 patients with squamous cell carcinoma before and after RT at doses of 9 and 27 Grays (Gy) were investigated for MIB-1 and PC10 immunoreactivities.

RESULTS

In adenocarcinomas, the mean MIB-1 labeling indices before and after RT at 9 and 27 Gy were 28%, 21%, and 26%, respectively, whereas the mean PC10 labeling indices were 15%, 13%, and 14%, respectively. In squamous cell carcinomas, the mean MIB-1 labeling indices before and after RT at 9 and 27 Gy were 38%, 53%, and 26%, respectively, and the mean PC10 labeling indices were 23%, 23%, and 11%, respectively.

CONCLUSIONS

Cervical adenocarcinomas have a lower cycling cell population and their indices show no change during RT. Squamous cell carcinomas have a higher cycling cell population and show a transient increase of the MIB-1 cycling cell population at 9 Gy of RT. These findings suggest a difference in response to RT between adenocarcinomas and squamous cell carcinomas.

Endothelin-mediated effect of erythropoietin on blood pressure and renal hemodynamics in hypertensive rats

Erythropoietin (EPO) has been reported to induce hypertension in hemodialysis patients with family history of hypertension. In this study, to reveal the mechanism of EPO-induced hypertension, we examined the acute effect of EPO on blood pressure (BP) and renal hemodynamics in genetically hypertensive rats, and we also tested the effect of BQ-123, an endothelin ETA-receptor blocker, on EPO-induced changes in hemodynamics. Male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY), aged 9-12 wk, were anesthetized, and BP was monitored through the carotid artery. Renal plasma flow (RPF) and glomerular filtration rate (GFR) were measured before and after an intravenous injection of EPO (1,000 U/kg body wt). In another group of SHR, BQ-123 was continuously infused (1.2 mg.kg body wt-1.h-1) during the experiments. The acute injections of EPO increased BP significantly in SHR in a dose-dependent manner, whereas WKY did not show a significant increase in BP after EPO injections. The effect of EPO on BP in SHR was blocked by BQ-123. In SHR, an acute injection of EPO decreased RPF significantly (from 1.78 +/- 0.16 to 1.49 +/- 0.18 ml.min-1.100 g body wt-1, P < 0.05) without a change in GFR, whereas WKY did not show significant changes in either RPF or GFR. The effect of EPO on RPF in SHR was completely blocked by BQ-123 (from 1.92 +/- 0.26 to 1.88 +/- 0.28 ml.min-1.100 g wt-1, NS). EPO caused a significant increase in plasma endothelin ET-1 in SHR (from 2.3 +/- 0.6 to 6.3 +/- 1.6 pg/ml, P < 0.05), but not in WKY. In conclusion, acute administration of EPO raised blood pressure and reduced RPF in SHR, and these vasoconstrictive effects of EPO are mediated via ETA receptors by an enhanced ET-1 release.

Intratumoral administration of sizofiran activates Langerhans cell and T-cell infiltration in cervical cancer

In order to ascertain a correlation between infiltration of Langerhans cells (LCs) or T-cells in tumor tissues and the intratumoral administration of a biological response modifier, Sizofiran (SPG) was analyzed in cancer of the uterine cervix. Cancer specimens of 45 patients with stage II-III invasive cervical cancers were analyzed. SPG was administered to the cervical tumor at high and low concentrations (Strong SPG and weak SPG) as well as by intramuscular injection twice a week. LC and T-cell infiltrations to tumor tissues of the uterine cervix were studied immunohistochemically and electron microscopically. Of 10 patients with systemic but no local immunization, 1 (10.0%) showed an increase in LC infiltration and 2 (20.0%) showed a decrease. Of 15 patients with strong SPG immunization, 2 (13%) showed an increase and 5 (33%) showed a decrease. In contrast, of 20 patients with weak SPG immunization, the incidence of increase in LC infiltration was 55% (11 patients), significantly greater than the above-mentioned groups and none showed a decrease. Of the 20 patients with weak SPG administration, 3 (15%) showed T-cell infiltration before SPG administration, and 12 (60%) showed an increase in T-cell infiltration after SPG was given. Up on electron microscopy, Birbeck granules in the cytoplasm of LC significantly increased after SPG immunization, indicating activation of LC. In conclusion, the present study suggested that the LC and T-cell infiltrations in cancer tissues were augmented by intratumoral SPG administration at a certain concentration. Intratumoral administration of SPG may be applied to improve the prognosis after multidisciplinary treatment of advanced cervical cancer.

The significance of artificial cerebrospinal fluid as perfusate and endoneurosurgery

To compare the benefits of physiological saline solution and artificial cerebrospinal fluid (CSF) as perfusates, we investigated 12 patients with presumed symptomatic aqueductal stenosis by clinical course and CSF analysis. In all patients, endoneurosurgical third ventriculostomy and cine magnetic resonance imaging confirmed the patency of ventriculostomy. After endoneurosurgery, patients who received the saline solution experienced high fever, headaches, and elevated cell count in lumbar CSF. Saline solution provoked a striking inflammatory reaction in the CSF. In contrast, the artificial CSF reduced these conditions to a minimum. Artificial CSF used as a physiological perfusate during endoneurosurgery can suppress host reactions within the CSF pathway and is also available for routine neurosurgical procedures.

Isolation of a novel gene down-regulated by v-src

We have isolated a novel gene which was expressed in normal rat cells, but completely suppressed in cells transformed by v-src. The molecularly cloned cDNA was about 1.8 kb in size, containing an open reading frame composed of 464 amino acid residues. DNA sequence analysis showed that there was no corresponding gene in the data bases. Besides the suppression of gene expression in the v-src transformed cells, its expression was also strongly suppressed in cells transformed by other oncogenes such as v-abl, v-fps, v-mos, v-sis, v-K-ras, and polyomavirus middle T, but not affected in cells transformed by human papillomavirus type 16 E6E7 and polyomavirus large T. We named the gene drs for a gene down-regulated by v-src.

Reversal of hypercholesterolemia in low density lipoprotein receptor knockout mice by adenovirus-mediated gene transfer of the very low density lipoprotein receptor

We have used the technique of adenovirus-mediated gene transfer to study the in vivo function of the very low density lipoprotein receptor (VLDLR) in low density lipoprotein receptor (LDLR) knockout mice. We generated a replication-defective adenovirus (AdmVLDLR) containing mouse VLDLR cDNA driven by a cytomegalovirus promoter. Transduction of cultured Hepa (mouse hepatoma) cells and LDLR-deficient CHO-ldlA7 cells in vitro by the virus led to high-level expression of immunoreactive VLDLR proteins with molecular sizes of 143 kDa and 161 kDa. Digestion of the cell extract with the enzymes neuraminidase, N-glycanase, and O-glycanase resulted in the stepwise lowering of the apparent size of the 161-kDa species toward the 143-kDa species. LDLR (-/-) mice fed a 0.2% cholesterol diet were treated with a single intravenous injection of 3 x 10(9) plaque-forming units of AdmVLDLR. Control LDLR (-/-) mice received either phosphate-buffered saline or AdLacZ, a similar adenovirus containing the LacZ cDNA instead of mVLDLR cDNA. Comparison of the plasma lipids in the 3 groups of mice indicates that in the AdmVLDL animals, total cholesterol is reduced by approximately 50% at days 4 and 9 and returned toward control values on day 21. In these animals, there was also a approximately 30% reduction in plasma apolipoprotein (apo) E accompanied by a 90% fall in apoB-100 on day 4 of treatment. By FPLC analysis, the major reduction in plasma cholesterol in the AdmVLDLR animals was accounted for by a marked reduction in the intermediate density lipoprotein/low density lipoprotein (IDL/LDL) fraction. Plasma VLDL, IDL/LDL, and HDL were isolated from the three groups of animals by ultracentrifugal flotation. In the AdmVLDLR animals, there was substantial loss (approximately 65%) of protein and cholesterol mainly in the IDL/LDL fraction on days 4 and 9. Nondenaturing gradient gel electrophoresis indicates a preferential loss of the IDL peak although the LDL peak was also reduced. When 125I-IDL was administered intravenously into animals on day 4, the AdmVLDLR animals cleared the 125I-IDL at a rate 5-10 times higher than the AdLacZ animals. We conclude that adenovirus-mediated transfer of the VLDLR gene induces high-level hepatic expression of the VLDLR and results in a reversal of the hypercholesterolemia in 0.2% cholesterol diet-fed LDLR (-/-, mice. The VLDLR overexpression appears to greatly enhance the ability of these animals to clear IDL, resulting in a marked lowering of the plasma IDL/LDL. Further testing of the use of the VLDLR gene as a therapeutic gene for the treatment of hypercholesterolemia is warranted.

PRAD1/Cyclin D1 gene overexpression in mantle cell lymphoma

The t(11;14) (q13;q32) translocation and its molecular counterpart Bcl-1 rearrangement are consistent features of mantle cell lymphoma (MCL). This translocation activates the PRAD1/cyclin D1 gene that is considered to be the Bcl-1 oncogene. PRAD1/cyclin D1 gene overexpression is closely associated with MCL. The PRAD1/cyclin D1 protein is localized to the nucleus, and the strong correlation between PRAD1/cyclin D1 and MCL is also found in the protein level. This finding indicates that PRAD1/cyclin D1 expression is a highly specific and sensitive molecular marker for MCL. This gene may function as an oncogene in the malignant transformation of cells.

Disparate effects of calcium antagonists on renal microcirculation

Although calcium antagonists reduce systemic blood pressure, the effects of calcium antagonists on renal preglomerular and postglomerular microcirculation have been suggested to differ. In the present study we examined the vasodilator action of dihydropyridine-type calcium antagonists, including nifedipine, nicardipine, amlodipine, and efonidipine, on afferent and efferent arterioles during angiotensin II (A-II)- and norepinephrine (NE)-induced renal vasoconstriction. Isolated perfused hydronephrotic kidneys were used to directly visualize renal microcirculatory response to calcium antagonists. Both A-II and NE caused marked vasoconstriction of afferent (A-II, 27 +/- 2% decrement; NE, 28 +/- 2% decrement) and efferent arterioles (A-II, 25 +/- 4% decrement; NE, 22 +/- 2% decrement). The subsequent addition of nifedipine, nicardipine, and amlodipine reversed the afferent arteriolar vasoconstriction in a dose-dependent manner, and elicited complete vasodilation at 10(-6) M. In contrast, efferent arteriolar vasoconstriction was relatively refractory to the dilator action of these calcium antagonists; maximal dilation observed at 10(-6) M was 21 +/- 1% (A-II) and 22 +/- 3% (NE) for nifedipine, 25 +/- 3% (A-II) and 20 +/- 6% (NE) for nicardipine, and 39 +/- 6% (A-II) and 37 +/- 3% (NE) for amlodipine. In striking contrast, efonidipine dilated not only afferent arterioles, but also efferent arterioles in a dose-dependent manner. At 10(-6) M, efonidipine completely inhibited the afferent (A-II, 89 +/- 7% reversal; NE, 99 +/- 8% reversal) and efferent arteriolar vasoconstriction (A-II, 93 +/- 4% reversal; NE, 87 +/- 9% reversal). These findings clearly demonstrate that calcium antagonists dilate the afferent arteriole. Unlike the effects on the afferent arteriole, efferent arteriolar responsiveness to calcium antagonists differ, depending on the type of calcium antagonist. The efonidipine-induced efferent arteriolar vasodilation is probably not related to voltageoperated calcium channels, and may act, in concert with blood pressure lowering effect, to ameliorate glomerular capillary hypertension.

Intracerebroventricular injection of tumor necrosis factor-alpha induces thermal hyperalgesia in rats

To investigate the role of tumor necrosis factor-alpha (TNF-alpha) in the brain in nociception, we injected recombinant human TNF-alpha (rhTNF-alpha; 1 pg-10 ng/rat) into the lateral cerebroventricle (LVC) in rats and observed the changes in paw withdrawal latency to radiant heat by using the plantar test for 90 min after injection. LCV injections of TNF-alpha at doses of 10 pg, 100 pg and 1 ng reduced paw withdrawal latency, showing a maximal response at a dose of 10 pg which peaked 60 min after injection. TNF-alpha at doses of 1 pg and 10 ng had no effect on nociception during the test period. The TNF-alpha (10 pg)-induced reduction in paw withdrawal latency was blocked by simultaneous injection of diclofenac (1 ng), a cyclooxygenase inhibitor, or interleukin-1 receptor antagonist (IL-1 ra, 10 ng). LCV injection of neither diclofenac (1 ng) nor IL-1 ra (10 ng) had any effect on nociception by itself. The results suggest that TNF-alpha in the brain induces thermal hyperalgesia and that the brain TNF-alpha-induced hyperalgesia is mediated by the central action of interleukin-1 and activation of the cyclooxygenase pathway of the arachidonate.

Potent growth inhibitory activity of a novel Ornithogalum cholestane glycoside on human cells: induction of apoptosis in promyelocytic leukemia HL-60 cells

Growth inhibitory activities of a novel 22-homo-23-norcholestane glycoside found in bulbs of Ornithogalum saundersiae were examined in vitro using human promyelocytic leukemia HL-60 cells, human T-lymphocytic leukemia MOLT-4 cells, and mitogen-stimulated human peripheral-blood mononuclear cells (PBMC). The growth of HL-60 cells and MOLT-4 cells was strongly suppressed in the presence of the glycoside; the IC50s of which were 21.0 and 18.0 nM, respectively. Suppressive effect of the glycoside on HL-60 cell growth appears to be mediated partially through induction of apoptosis which was demonstrated by the presence of DNA fragmentation of the leukemic cells. Flow cytometric analysis of glycoside-treated HL-60 cells also demonstrated apoptotic cells with low DNA content and showed a decrease of G0/G1 cells and a concomitant increase of S and/or G2M cells. The growth inhibiting effect of the glycoside on HL-60 cells was promoted by calcium and was inhibited in the presence of zinc, which support involvement of endonuclease activation in the glycoside-induced apoptosis. The glycoside also inhibited mitogen-stimulated blastogenesis of PBMC, the IC50 of which was 6.2 nM. These results provided the first evidence ever for the potent growth inhibitory activity of Ornithogalum glycoside on human leukemia cell lines and PBMC.

Successful erythropoietin treatment for severe anemia in nephrotic syndrome without renal dysfunction

A 62-year-old woman presented with nephrotic syndrome and severe anemia although the renal function was not impaired. Renal biopsy revealed the histology of membranoproliferative glomerulonephritis, and the proteinuria was resistant to steroid therapy. Iron deficiency, bleeding and other causes of anemia were ruled out, however, her serum erythropoietin level was inappropriately low. The anemia was rapidly corrected by administration of recombinant human erythropoietin. It is suggested that inappropriately low erythropoietin level, in part at least, accounts for the anemia in nephrotic syndrome. It is proposed that erythropoietin therapy should be taken into consideration for severe anemia in nephrotic syndrome even when the renal function is not impaired.

MIB1 growth fraction is not related to prognosis in cervical squamous cell carcinoma treated with radiotherapy

A monoclonal antibody, MIB1, recognizes Ki-67 antigen in routinely processed paraffin sections after microwave treatment. Cycling cells are positive for MIB1, and quiescent cells are negative for MIB1. MIB1 index represents the growth fraction of the cell population. Cervical biopsies taken from 186 patients with stage III squamous cell carcinoma prior to radiotherapy were investigated for MIB1 reactivity using an immunohistochemical method. Cancer cells that were positive for MIB1 showed an intranuclear or chromosomal positive pattern. The median MIB1 index was 43% (range, 18-74%). Of 186 patients, 87 had a MIB1 index of > 43% and the other 99 had an index of < 43%. The 5-year survival rates were 58% (50 of 87 patients) in the former group and 58% (57 of 99 patients) in the latter group. The chi 2 test indicated that no significant prognostic correlation existed between two groups (p = 0.989). We conclude that the MIB1 index demonstrates a considerable variation among patients and is not a predictive indicator of survival for patients with stage III cervical squamous cell carcinoma.

Hemostatic abnormalities and increased vascular endothelial cell markers in patients with red cell fragmentation syndrome induced by mitomycin C

We examined red cell fragmentation syndrome (RCFS) induced by mitomycin C (MMC) (13 patients), by thrombotic thrombocytopenic purpura (TTP) (17 patients), and by disseminated intravascular coagulation (DIC) (15 patients). Plasma cytokine levels were increased in the TTP and DIC patients, but not in those whose RCFS was induced by MMC, suggesting that the activation of the immune system plays an important role in the pathogenesis of RCFS due to TTP and DIC but did not in RCFS due to MMC. Plasma thrombomodulin, tissue type plasminogen activator, and plasminogen activator inhibitor-I levels were increased in all RCFS patients, suggesting that RCFS, whether MMC induced, or due to TTP or DIC, might be associated with vascular endothelial cell injury. In TTP, von Willebrand factor (vWF) antigen and high molecular weight vWF multimer levels were reduced, possibly as a result of microthrombus consumption. The hemostatic data in this study showed that the TTP patients were in a hypercoagulable state without hyperfibrinolysis, and that DIC patients were in both a hypercoagulable and a hyperfibrinolytic state, whereas hemostatic abnormalities were slight in patients with MMC induced RCFS. These findings suggest that vascular endothelial cell injuries might be associated with RCFS, and that those injuries in MMC-induced RCFS might not be related to microthrombi or an activated immune system.

In vivo microdialysis evidence for transient dopamine release by benzazepines in rat striatum

The effects of benzazepine derivatives on extracellular levels of dopamine (DA) and L-3,4-dihydroxy-phenylacetic acid (DOPAC) in the dorsal striatum of freely moving rats were studied using in vivo microdialysis. Direct injection of SKF-38393 (0.5 or 1.5 micrograms/0.5 microliter), a selective D1 receptor agonist, into the striatum through a cannula secured alongside a microdialysis probe produced a rapid dose-dependent transient increase in striatal DA efflux and a more gradual reduction in efflux of DOPAC. The rapid increase in DA efflux was not affected by infusion of tetrodotoxin (TTX; 2 microM) or Ca(2+)-free Ringer's solution and occurred after either enantiomer of SKF-38393. A TTX-insensitive increase in DA level similar to that induced by SKF-38393 was also seen after other benzazepines acting as agonists (SKF-75670 and SKF-82958, each 1.5 micrograms in 0.5 microliter) and antagonists (SCH-23390, 1.5 micrograms in 0.5 microliter) at the D1 receptor and after (+)-amphetamine. These effects were inhibited by infusion of nomifensine (100 microM). It is concluded that the transient increases in striatal DA efflux seen after intrastriatal injection of SKF-38393 and other benzazepines are not mediated by presynaptic D1 receptors but by an amphetamine-like action on the dopamine transporter.

Frequent expression of P-glycoprotein/MDR1 by nasal T-cell lymphoma cells

BACKGROUND

Lethal midline granuloma is now considered to be a malignant lymphoma derived from peripheral T cells or from natural killer cells. The therapeutic outcome of nasal T-cell lymphoma (NL) treated by conventional chemotherapy for non-Hodgkin's lymphoma is poor, although some patients have a good response to radiotherapy. To clarify the mechanisms of drug resistance, the expression of P-glycoprotein (P-gp)/MDR1, which is the product of the multidrug resistance (MDR) 1 gene, and MDR3 mRNA in NL cells, were examined.

METHODS

Ten Japanese patients with NL were studied. Nine of these patients were examined before therapy. P-glycoprotein expression and phenotypes of lymphoma cells were examined by immunohistochemical staining using UIC2 as an anti-P-gp monoclonal antibody. In one case, the Rhodamine-123 efflux test was performed. MDR1 and MDR3 mRNA were detected by reverse transcription polymerase chain reaction.

RESULTS

Nine of the 10 patients were P-gp positive. In one of nine, functional P-gp expression was observed. MDR1 mRNA was detected in all seven examined patients with P-gp positive NLs, whereas MDR3 mRNA was negative. Retrospectively, patients who received chemotherapy alone had poorer outcome than those treated by combination chemotherapy after irradiation.

CONCLUSION

The poor prognosis for patients with NL treated with chemotherapy may be explained by P-gp expression of the NL cells.

The radiographic restoration of the ventricular system after third ventriculostomy

Ten adult patients were treated by third ventriculostomy for idiopathic aqueductal stenosis. Idiopathic aqueductal stenosis was diagnosed according to MR imaging; aqueductal stenosis secondary to tumor, hemorrhage, and/or infection was excluded. Following a third ventriculostomy under a flexible neuroendoscope, all patients were reviewed at 1, 3, 6, 12, and 24 months, and MR images with ventricular measurements were repeated for evaluation of the radiographic restoration of the ventricular system. The ventricular structures arranged in order of restoration were the size of the III ventricle, the upward deviation of the brain stem, and the size of the lateral ventricle in response to third ventriculostomy. The restoration of the whole ventricle steadied within two years. Our results contribute new information regarding restoration of the ventricular system under aqueductal stenosis and produce evidence that third ventriculostomy is a reasonable treatment based upon the patient's physiological condition.

Citrus flavone tangeretin inhibits leukaemic HL-60 cell growth partially through induction of apoptosis with less cytotoxicity on normal lymphocytes

Certain anti-cancer agents are known to induce apoptosis in human tumour cells. However, these agents are intrinsically cytotoxic against cells of normal tissue origin, including myelocytes and immunocytes. Here we show that a naturally occurring flavone of citrus origin, tangeretin (5,6,7,8,4'-pentamethoxyflavone), induces apoptosis in human promyelocytic leukaemia HL-60 cells, whereas the flavone showed no cytotoxicity against human peripheral blood mononuclear cells (PBMCs). The growth of HL-60 cells in vitro assessed by [3H]thymidine incorporation or tetrazolium crystal formation was strongly suppressed in the presence of tangeretin; the IC50 values range between 0.062 and 0.173 microM. Apoptosis of HL-60 cells, assessed by cell morphology and DNA fragmentation, was demonstrated in the presence of > 2.7 microM tangeretin. Flow cytometric analysis of tangeretin-treated HL-60 cells also demonstrated apoptotic cells with low DNA content and showed a decrease of G1 cells and a concomitant increase of S and/or G2/M cells. Apoptosis was evident after 24 h of incubation with tangeretin, and the tangeretin effect as assessed by DNA fragmentation or growth inhibition was significantly attenuated in the presence of Zn2+, which is known to inhibit Ca(2+)-dependent endonuclease activity. Ca2+ and Mg2+, in contrast, promoted the effect of tangeretin. Cycloheximide significantly decreased the tangeretin effect on HL-60 cell growth, suggesting that protein synthesis is required for flavonoid-induced apoptosis. Tangeretin showed no cytotoxicity against either HL-60 cells or mitogen-activated PBMCs even at high concentration (27 microM) as determined by a dye exclusion test. Moreover, the flavonoid was less effective on growth of human T-lymphocytic leukaemia MOLT-4 cells or on blastogenesis of PBMCs. These results suggest that tangeretin inhibits growth of HL-60 cells in vitro, partially through induction of apoptosis, without causing serious side-effects on immune cells.

The opposing effects of interleukin -1 beta microinjected into the preoptic hypothalamus and the ventromedial hypothalamus on nociceptive behavior in rats

The effects of microinjections of recombinant human interleukin-1 beta (rhIL-1 beta) into the hypothalamus and neighboring basal forebrain on nociceptive behavior were studied using a hot-plate test in rats. The microinjection of rhIL-1 beta at doses between 5 pg/kg and 50 pg/kg into the medial part of the preoptic area (MPO) reduced the paw-withdrawal latency. The maximal reduction was obtained 30 min after the injection of rhIL-1 beta at 20 pg/kg. RhIL-1 beta (20 pg/kg)-induced hyperalgesia was completely blocked by the simultaneous injection of IL-1 receptor antagonist (IL-1ra, 20 ng/kg), Na salicylate (200 ng/kg) or alpha-melanocyte-stimulating hormone alpha-MSH, 20 ng/kg). The intra-MPO injection of rhIL-1 beta at doses of less than 5 pg/kg or more than 50 pg/kg (up to 2 ng/kg) into the paraventricular nucleus, the lateral hypothalamic area and the septal nucleus had no effect on nociception. The microinjection rhIL-1 beta (20 pg/kg-50 pg/kg) into the ventromedial hypothalamus produced a prolongation of the paw-withdrawal latency. A maximal prolongation was obtained 10 min after the injection of rhIL-1 beta at 50 pg/kg. This reaction was also blocked by the simultaneous injection of IL-1ra (50 ng/kg) and Na salicylate (500 ng/kg). These findings indicate that IL-1 beta in the MPO and the VMH produces hyperalgesia and analgesia, respectively, while, in addition, both effects are mediated by IL-1 receptors and the synthesis of prostaglandins.

Tissue-specific expression and cholesterol regulation of acylcoenzyme A:cholesterol acyltransferase (ACAT) in mice. Molecular cloning of mouse ACAT cDNA, chromosomal localization, and regulation of ACAT in vivo and in vitro

Acyl-coenzyme A:cholesterol acyltransferase (ACAT) catalyzes the esterification of cholesterol with long chain fatty acids and is believed to play an important part in the development of atherosclerotic lesions. To facilitate the study of ACAT's role in this process, we have used the human ACAT K1 clone previously described (Chang, C. C. Y., Huh, H. Y., Cadigan, K. M. and Chang, T. Y. (1993) J. Biol. Chem. 268, 20747-20755) to isolate mouse ACAT cDNA from a liver cDNA library. The 3.7-kilobase cDNA clone isolated contains a 1620-base pair open reading frame which encodes a protein of 540 amino acids. The predicted mouse ACAT protein is 87% identical to the protein product of human ACAT K1 and shares many of the same secondary structural features, including two transmembrane domains, a leucine heptad motif consistent with dimer or multimer formation, and five regions homologous to the "signature sequences" found in other enzymes that catalyze acyl adenylation followed by acyl thioester formation and acyl transfer. Using the cDNA as a hybridization probe, we mapped the gene encoding mouse ACAT to chromosome 1 in a region syntenic to human chromosome 1 where the ACAT gene is located. Northern blot analysis and RNase protection assays of mouse tissues revealed that ACAT mRNA is expressed most highly in the adrenal gland, ovary, and preputial gland and is least abundant in skeletal muscle, adipose tissue, heart, and brain. To study the dietary regulation of ACAT mRNA expression in mouse tissues, we fed C57BL/6J mice a high-fat, high-cholesterol (HF/HC) atherogenic diet for 3 weeks and measured ACAT mRNA levels in various tissues by RNase protection. The HF/HC diet had little effect on ACAT mRNA levels in the small intestine, aorta, adrenal, or peritoneal macrophages, whereas hepatic ACAT mRNA levels were doubled in mice fed the atherogenic diet. ACAT activity in liver microsomes was similarly increased in cholesterol-fed mice, suggesting that mouse ACAT is regulated at least in part at the level of mRNA abundance. Additionally, a significant positive correlation was observed between ACAT activity and microsomal free cholesterol levels in chow- and cholesterol-fed mice, supporting the concept of cholesterol availability as a regulator of ACAT. To further investigate the regulation of ACAT activity under controlled conditions, ACAT-deficient Chinese hamster ovary cells were stably transfected with the mouse ACAT cDNA clone driven by a cytomegalovirus promoter. Two transfected Chinese hamster ovary cell lines that expressed the mouse ACAT transgene regained the ability to esterify cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)

Frequent expression of shared idiotypes in mantle cell lymphoma and extranodal small lymphocytic/non-mantle cell diffuse small cleaved lymphoma

A panel of 14 anti-shared idiotype (Sid) monoclonal antibodies selected according to their high cross-reactivity to various lymphomas was immunohistologically tested for reactivity with seven reactive lymphoid tissue specimens and 227 B cell lymphoma specimens obtained from Japanese patients. In the reactive lymphoid tissues, the anti-Sld antibodies each reacted with a subpopulation of cells in the mantle zone and interfollicular areas; they rarely reacted with cells in the germinal center. In the B cell lymphomas, 13 anti-Sld antibodies reacted with a total of 78 of 186 (42%) specimens bearing immunoglobulin; none of the antibodies reacted with 41 specimens not bearing immunoglobulin. In mantle cell lymphomas (15/19, 79%) and extranodal small lymphocytic/non-mantle cell diffuse small cleaved lymphomas (11/15, 73%), the reactivity of the antibodies was high compared with that in the other lymphomas (52/152, 34%; P = 0.0002 and 0.004, respectively), including follicular lymphomas (11/42, 27%; P = 0.002 and 0.002, respectively). Since idiotypes are associated with the hypervariable regions and antigen-binding sites of immunoglobulin, these findings may reflect the differences in the regions/sites in each of these diseases.