Analysis of genetic and phenotypic heterogeneity in juvenile polyposis

BACKGROUND

Juvenile polyposis syndrome (JPS) is characterised by gastrointestinal (GI) hamartomatous polyposis and an increased risk of GI malignancy. Juvenile polyps also occur in the Cowden (CS), Bannayan-Ruvalcaba-Riley (BRRS) and Gorlin (GS) syndromes. Diagnosing JPS can be problematic because it relies on exclusion of CS, BRRS, and GS. Germline mutations in the PTCH, PTEN and DPC4 (SMAD4) genes can cause GS, CS/BRRS, and JPS, respectively.

AIMS

To examine the contribution of mutations in PTCH, PTEN, and DPC4 (SMAD4) to JPS.

METHODS

Forty seven individuals from 15 families and nine apparently sporadic cases with JPS were screened for germline mutations in DPC4, PTEN, and PTCH.

RESULTS

No patient had a mutation in PTEN or PTCH. Five different germline mutations were detected in DPC4; three of these were deletions, one a single base substitution creating a stop codon, and one a missense change. None of these patients had distinguishing clinical features.

CONCLUSIONS

Mutations in PTEN and PTCH are unlikely to cause juvenile polyposis in the absence of clinical features indicative of CS, BRRS, or GS. A proportion of JPS patients harbour DPC4 mutations (21% in this study) but there remains uncharacterized genetic heterogeneity in JPS.

Limited incremental diagnostic values of attenuation-noncorrected gating and ungated attenuation correction to rest/stress myocardial perfusion SPECT in patients with an intermediate likelihood of coronary artery disease

Either gated myocardial perfusion SPECT or attenuation-corrected SPECT can be used to improve specificity in the diagnosis of coronary artery disease (CAD). We investigated whether attenuation-noncorrected gating and ungated attenuation correction could improve the diagnostic performance of rest/stress perfusion SPECT in patients having an intermediate pretest likelihood of CAD.

METHODS

Sixty-eight patients (29 men, 39 women; mean age, 59 +/- 12 y) with coronary artery stenosis > or =70% (1 vessel, n = 13; 2 vessels, n = 18; 3 vessels, n = 8; normal, n = 29) underwent rest attenuation-corrected 201TI SPECT and dipyridamole stress gated attenuation-corrected 99mTc-methoxyisobutyl isonitrile SPECT with an ADAC vertex camera. Three physicians graded the post-test likelihood of CAD for each arterial territory using a 5-point scale (1, normal; 2, possibly normal; 3, equivocal; 4, possibly abnormal; 5, abnormal). The sensitivity, specificity, and areas under receiver-operating-characteristic curves were compared for each operator by 3 methods: attenuation-noncorrected rest/stress SPECT, gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT, and attenuation-corrected rest/stress SPECT plus gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT.

RESULTS

When higher than grade 3 was used as the criterion for CAD, no differences in sensitivity and specificity were found among the 3 methods for each operator. Areas under receiver-operating-characteristic curves for the diagnosis of CAD and stenosis revealed no differences for each modality (P > 0.05 for each comparison).

CONCLUSION

In patients with an intermediate risk of CAD, viewing attenuation-noncorrected gated poststress SPECT and ungated attenuation-corrected rest/stress SPECT images did not improve the diagnostic performance for CAD and stenosis.

A phase Ib/II trial of granulocyte-macrophage-colony stimulating factor and interleukin-2 for renal cell carcinoma patients with pulmonary metastases: a case of fatal central nervous system thrombosis

BACKGROUND

Interleukin-2 (IL-2) and granulocyte-macrophage-colony stimulating factor (GM-CSF) are cytokines with nonoverlapping pleiotropic effects. In a prior Phase Ib study, this combination of agents exhibited antitumor effects in the lungs of four of eight patients with renal cell carcinoma and pulmonary metastases. We conducted this Phase Ib/II trial to determine the response rate of renal cell carcinoma patients with pulmonary metastases treated with continuous infusion IL-2 plus GM-CSF.

METHODS

Patients with renal cell carcinoma and pulmonary metastases were treated with 1.5, 2.25, or 4.5 x 10(6) IU/m(2)/day 96-hour continuous infusion IL-2 on Days 1-4, 8-11, and 15-18, and 1.25, 2.25, or 2.5 microg/kg/day GM-CSF on Days 8-19.

RESULTS

Sixteen patients were treated per protocol, 14 of whom could be evaluated for disease progression. None of these 14 patients had >50% shrinkage of either total tumor burden or pulmonary metastasis. One patient developed Grade 5 neurotoxicity. Autopsy revealed acute multifocal cerebral venous thrombosis as well as acute subdural and subarachnoid hemorrhage.

CONCLUSIONS

The combination of IL-2 and GM-CSF may be associated with marked morbidity and, as in one case in this study, mortality. No significant antitumor activity was appreciated. Thus, the combination of IL-2 and GM-CSF, when administered at this dose and according to this schedule, does not appear to be active in renal cell carcinoma and is associated with significant toxicities. Further studies using this combination of agents should only be undertaken with extreme caution and particular attention to neurotoxicity.

Synthesis and oral antitumor activity of tetrakis(carboxylato)platinum(IV) complexes

A novel class of tetrakis(carboxylato)platinum(IV) complexes, [Pt(O(2)CR)(4)(dach)] (dach = trans-(+/-)-1,2-diaminocyclohexane; R = C(n)H(2n+1), n = 1 approximately 5), was synthesized and studied for physicochemical properties and oral antitumor activity. Lipophilicity and aqueous solubility of the title complexes were greatly dependent on the alkyl chain length of the carboxylate ligand, and their partition coefficient and solubility changed by 4 or 5 orders of magnitude from acetate to hexanoate complexes. On the other hand, the range of their cathodic reduction potential (-546 approximately -403 mV) depending on the chain length of the carboxylate ligand was relatively small. Among the title complexes, the tetrakis(propionato)platinum(IV) complex, [Pt(O(2)CC(2)H(5))(4)(dach)], with appropriate lipophilicity (log P = 0.18) and aqueous solubility (14.6 mg/mL) was found to exhibit better oral antitumor activity than JM216 against the human ovarian tumor xenograft SKOV3 in nude mice.

Yomogin inhibits the degranulation of mast cells and the production of the nitric oxide in activated RAW 264.7 cells

Yomogin (1), an eudesmane sesquiterpene isolated from Artemisia princeps, was tested for the effects on the degranulation process of cultured mast cells and on the nitric oxide production in LPS-activated murine macrophages. It demonstrated a significant inhibition on the release of beta-hexosaminidase from the cultured RBL-2H3 cells in a dose-dependent manner (IC50 value, 50 microM) and also exhibited a potent inhibition on the nitric oxide production from the activated RAW264.7 cells (IC50 value, 3 microM).

Dosimetry of rhenium-188 diethylene triamine penta-acetic acid for endovascular intra-balloon brachytherapy after coronary angioplasty

To examine the possibility of using rhenium-188 diethylene triamine penta-acetic acid (DTPA) for endovascular intra-balloon brachytherapy after angioplasty, dose distribution around the balloon was calculated and validated by film dosimetry. Medical internal radiation dosimetry (MIRD) was calculated assuming that the balloon had ruptured and that the contents had been released into the systemic circulation. 188Re-perrhenate eluate from the 188W/188Re generator was concentrated using an ion column and used to label DTPA. The dose distribution around the angioplasty balloon (20 mm length, 3 mm diameter cylinder) was estimated by Monte Carlo simulation using the EGS4 code. The time required for 17.6 Gy to be absorbed at 1 mm from the balloon's surface following application of 3700 MBq/ml of 188Re was found to be 278 s. Fifty percent of the energy was deposited in the first millimetre of the vessel wall from the balloon's surface. The calculated radiation absorbed dose agreed with that measured by film dosimetry, which was performed using a water phantom, with errors ranging from 9.4% to 17%. Upon balloon rupture the total amount of 188Re-DTPA was presumed to enter the systemic circulation. The resulting radiation absorbed dose was calculated using the MIRDOSE3 program and residence times obtained from dogs and amounted to 0.0056 mGy/MBq to the whole body and 4.56 mGy/MBq to the urinary bladder. The absorbed dose of 188Re-DTPA to the whole body was one-tenth of that of 188Re-perrhenate. A window-based program was developed to calculate the exposure time and the radiation dose absorbed as a function of the 188Re concentration and the arbitrary distance from the balloon to the surrounding tissues. We conclude that 188Re-DTPA is easy to prepare, safe to use and suitable for intra-balloon brachytherapy after coronary angioplasty.

Hemoglobin toxicity in experimental bacterial peritonitis is due to production of reactive oxygen species

Hemoglobin (Hb) is a toxic molecule responsible for the extreme lethality associated with experimental Escherichia coli peritonitis, but the mechanism has yet to be elucidated. Hb, but not globin, showed toxic effects in a live E. coli model but not in a model using killed E. coli. Methemoglobin, hematin, and the well-known Fenton reagents iron and iron-EDTA demonstrated the same lethal effect in E. coli peritonitis as Hb, while the addition of the Fenton inhibitors desferrioxamine (DF) and diethylenetriamine pentaacetate removed most of the cytotoxic activity of iron. Administration of a combined dose of superoxide dismutase and catalase minimized the action of Hb and iron-EDTA, suggesting that both O(2)(.-) and H(2)O(2) are involved in the toxic action of Hb in this rat model. The combination of the antioxidative enzymes and DF further suppressed iron-mediated lethality. An electron spin resonance technique with the spin-trapping reagent 5, 5-dimethyl-1-pyroline-N-oxide (DMPO) showed O(2)(.-) generation in the peritoneal fluid of rats injected with E. coli alone or E. coli plus iron-DF, and (.)OH generation was detected in the peritoneal fluid of the rats injected with iron-EDTA. Hb did not show any spin adduct of oxygen radicals, suggesting that Hb produces non-spin-trapping radical ferryl ion, which decayed the spin adduct of DMPO. In the presence of Hb or iron-EDTA, O(2)(-)-generating activity and viability of phagocytes decreased, whereas lipid peroxidation of peritoneal phagocytes increased. Generation of oxygen radicals and lipid peroxidation did not differ in the live and dead bacterial models. Bacterial numbers in the peritoneal cavity and blood were markedly increased in the live bacterial model with Hb and iron-EDTA. The Fenton inhibitor iron-DF prevented the loss of phagocyte function, lipid peroxidation, and bacterial proliferation. These results led us to conclude that the lethal toxicity of Hb in bacterial peritonitis is associated with a Fenton-type reaction, the products of which decrease phagocyte viability, through the induction of lipid peroxidation, allowing bacterial proliferation and resulting in mortality.

Development of a method for measuring myocardial contractility with gated myocardial SPECT and arterial tonometry

BACKGROUND

Gated myocardial single photon emission computed tomography (SPECT) and radial artery applanation tonometry were used, respectively, to quantify the time-volume curve of the left ventricle and to estimate ventricular pressure wave. We developed ways of determining end-systolic elastance (Ees) with the normalized-single-beat method and tested the reproducibility of these measurements.

METHODS AND RESULTS

In patients with coronary artery disease (male/female = 33:2, age 66 +/- 10 years, ejection fraction 22% to 77%), rest thallium-201 gated/poststress technetium-99m sestamibi gated SPECT/24-hour rest Tc-99m sestamibi gated SPECT and arterial tonometry were performed. Quantitative gated SPECT software yielded a systolic time-volume curve, and tonometrically measured radial artery pressure wave yielded central aortic pressure wave. With systolic half of pressure-volume curve, void volume (Vo) was estimated and Ees was calculated. Over 71 measurements Ees ranged from 1.7 to 5.3 and Vo from -4 to 200 mL. Ejection duration, other indexes of central pressure waveform, end-diastolic volume, end-systolic volume, and ejection fraction were reproducible. The reproducibility of Vo was excellent (r = 0.97). Ees at rest (n = 15) showed fair reproducibility between Tc-99m-sestamibi and TI-201 SPECT (r = 0.51).

CONCLUSION

With gated myocardial SPECT, a noninvasive method of quantifying myocardial global contractility was developed. Reproducibility of this measurement was sufficient for use in clinical routine. Ees measured by this method warrants validation by invasively measured Ees.

Application of infrequent-restriction-site PCR to clinical isolates of Acinetobacter baumannii and Serratia marcescens

We applied infrequent-restriction-site PCR (IRS-PCR) to the investigation of an outbreak caused by 23 isolates of Acinetobacter baumannii in an intensive care unit from November 1996 to May 1997 and a pseudoepidemic caused by 16 isolates of Serratia marcescens in a delivery room from May to September 1996. In the epidemiologic investigation of the outbreak caused by A. baumannii, environmental sampling and screening of all health care workers revealed the same species from the Y piece of a mechanical ventilator and the hands of two health care personnel. IRS-PCR showed that all outbreak-related strains were genotypically identical and that three strains from surveillance cultures were also identical to the outbreak-related strains. In a pseudoepidemic caused by S. marcescens, IRS-PCR identified two different genotypes, and among them one genotype was predominant (15 of 16 [93.8%] isolates). Extensive surveillance failed to find any source of S. marcescens. Validation of the result of IRS-PCR by comparison with that of field inversion gel electrophoresis (FIGE) showed that they were completely concordant. These results suggest that IRS-PCR is comparable to FIGE for molecular epidemiologic studies. In addition, IRS-PCR was less laborious and less time-consuming than FIGE. To our knowledge, this is the first report of the application of IRS-PCR to A. baumannii and S. marcescens.

Somatic mutations of the first 14 exons of APC in hamartomatous polyps of the colon

Although hamartomatous or hyperplastic polyps are rarely accompanied by adenomatous or carcinomatous foci, the role of APC (MIM# 175100) mutations in these polyps is not clear. The neoplastic potential of these polyps was assessed with regard to somatic mutation of the first 14 exons of APC. DNA from 14 hamartomatous polyps (12 patients with juvenile polyp, JP; two patients with Peutz-Jeghers syndrome, PJS) and 27 hyperplastic polyps was used. Exons 1-14 of APC were amplified using verified oligonucleotide primers, and PCR-SSCP analysis was performed. Translation-terminating mutation in exon 15 was also screened using the protein truncation test. All mutations found were transitions or transversions with heterozygous alleles of both wild-type and mutant APC in exons 2, 9, 10, and 11. Four hamartomatous polyps (three from JP and one from PJS) showed seven, new mutations and one common APC variant (codon 486), whereas no hyperplastic polyps demonstrated mutation. APC mutation was not correlated with previous history of colorectal carcinoma or number of polyps. Since all mutations were missense or silent mutations occurred in exons not previously known to have functionally relevant area, their phenotypic implication appeared to be limited.

Inhibition of mast cell degranulation by tanshinones from the roots of Salvia miltiorrhiza

The activity-guided fractionation of the extract of the root of Salvia miltiorrhiza B. (Labiatae, Tanshen), led to the isolation of four active components responsible for the anti-allergic activity in vitro. Among them, 15,16-dihydrotanshinone-I and cryptotanshinone demonstrated significant inhibition of the release of beta-hexosaminidase from cultured RBL-2H3 cells in a dose-dependent manner; the IC50 values were calculated as 16 and 36 microM, respectively.

Role of definitive radiation therapy for larynx preservation in patients with advanced laryngeal cancer

OBJECTIVE

Recently, neoadjuvant chemotherapy (CT) and radiation therapy (RT) have been advocated as a standard treatment for laryngeal preservation in patients with locally advanced laryngeal cancer. However, it is still being debated whether adding neoadjuvant CT to conventional RT makes an effective contribution to laryngeal preservation. The current study was designed to resolve this controversy.

DESIGN

Retrospective clinical study.

SETTING

The Severance Hospital, Yonsei Cancer Center, Yonsei University, Seoul, Korea.

METHOD

Eighty patients (stages III, IV) with squamous cell carcinoma of the larynx were divided into two groups according to treatment modalities, which consisted of RT alone (N = 40, Group 1) and neoadjuvant CT plus RT (N = 40, Group 2). Comparative analysis was undertaken to investigate the differences in the organ preservation rate and treatment results between the two groups.

RESULTS

There was no significant difference in the response rate and patterns of treatment failure between the two groups. The 5-year survival rate was similar between Group 1 (24%) and Group 2 (31%) (p = .1556). In addition, the larynx was almost equally preserved in Group 1 (62%) versus Group 2 (63%).

CONCLUSIONS

Radiation therapy without neoadjuvant CT seems to be a valid alternative treatment for the purpose of laryngeal preservation in locally advanced laryngeal cancer.

Relationship between intratumor histological heterogeneity and genetic abnormalities in gastric carcinoma with microsatellite instability

Microsatellite instability (MSI)-mutator phenotype variably targets microsatellite-like sequences in coding regions of cancer-related genes. Intratumor histological heterogeneity of gastric carcinoma with MSI was evaluated and found to be linked with the topographical distribution of MSI-associated mutations. One hundred fifty tumor sites derived from 51 gastric cancer patients were microdissected with respect to histological and topographical clonality. We found 11 gastric carcinomas with a high frequency of MSI, which were characterized by marked intratumor genetic heterogeneity arising from the progressive MSI-phenotype that was associated with frameshift mutations on multiple cancer-related genes. The 11 MSI-tumor cases manifested the MSI-phenotype in 34 of 36 tumor sites tested, but not in the remaining 2 sites. Most (88.2%, 30 of 34) MSI-positive sites and most (96.2%, 25 of 26) tumor sites harboring the frameshift mutations in transforming growth factor-beta receptor type II gene exhibited intestinal-type histology, whereas the 2 MSI-negative sites were found to be of diffuse-type histology without accompanying frameshift mutations. In 2 of 5 cases harboring E2F-4 frameshift mutations, glandular structures of intestinal-type tumor were likely to be variably differentiated in relation to the extent of the mutation, i.e., the number of mutated alleles and the size of deleted or inserted base pairs. Overall, the intratumor histological heterogeneity of gastric carcinoma with MSI was associated with the progressive frameshift mutations in transforming growth factor-beta receptor type II and E2F-4 genes.

Curcumin inhibits Th1 cytokine profile in CD4+ T cells by suppressing interleukin-12 production in macrophages

1 Interleukin-12 (IL-12) plays a central role in the immune system by driving the immune response towards T helper 1 (Th1) type responses which are characterized by high IFN-gamma and low IL-4 production. In this study we investigated the effects of curcumin, a natural product of plants obtained from Curcuma longa (turmeric), on IL-12 production by mouse splenic macrophages and the subsequent ability of these cells to regulate cytokine production by CD4+ T cells. 2 Pretreatment with curcumin significantly inhibited IL-12 production by macrophages stimulated with either lipopolysaccharide (LPS) or head-killed Listeria monocytogenes (HKL). 3 Curcumin-pretreated macrophages reduced their ability to induce IFN-gamma and increased the ability to induce IL-4 in Ag-primed CD4+ T cells. Addition of recombinant IL-12 to cultures of curcumin-pretreated macrophages and CD4+ T cells restored IFN-gamma production in CD4+ T cells. 4 The in vivo administration of curcumin resulted in the inhibition of IL-12 production by macrophages stimulated in vitro with either LPS or HKL, leading to the inhibition of Th1 cytokine profile (decreased IFN-gamma and increased IL-4 production) in CD4+ T cells. 5 These findings suggest that curcumin may inhibit Th1 cytokine profile in CD4+ T cells by suppressing IL-12 production in macrophages, and points to a possible therapeutic use of curcumin in the Th1-mediated immune diseases.

No further development of renal scarring after antireflux surgery in children with primary vesicoureteral reflux: review of the results of 99mtechnetium dimercapto-succinic acid renal scan

PURPOSE

Reports of previous studies using excretory urography indicate that significant numbers of new scars developed in 5 to 31% of cases and scarring progressed in 11 to 16% after antireflux surgery. We evaluated renal scarring after surgery using a more accurate method, that is dimercapto-succinic acid renal scintigraphy.

MATERIALS AND METHODS

Between 1985 and 1997 antireflux surgery was performed for primary vesicoureteral reflux in 223 children at our hospital. Of these patients 45 boys and 29 girls with a median age of 74 months at surgery in whom preoperative and postoperative renal scans were available form the basis of our retrospective study. Renal scan was performed 0.3 to 58 months (median 2) preoperatively and 5.3 to 44 months (median 18.7) postoperatively. A total of 24 children (39 renal units) were followed further by additional scanning for as long as 25 to 120 months (median 43.2) postoperatively. Each scan was blindly reviewed for the size, number and zone location of cortical defects based on morphology. Interval changes were grouped into categories as improved, no change, progressed and new scar formation.

RESULTS

Postoperatively there was no ureteral obstruction. Pyelonephritis developed in 2 patients (2.7%) and asymptomatic bacteriuria was noted in 35 (47.3%) postoperatively. Of the renal units 110 (86.6%) showed no change, while 15 (11.8%) were improved and 2 (1.6%) had progression. In no case was new renal scar formation observed.

CONCLUSIONS

Contrary to most previous reports involving excretory urography, our results indicate no significant progression of renal scarring after antireflux surgery. In most cases postoperative followup renal scans demonstrated no significant morphological change. When there was change, it mostly involved the disappearance or decrease of renal scars.

No further development of renal scarring after antireflux surgery in children with primary vesicoureteral reflux: review of the results of 99mtechnetium dimercapto-succinic acid renal scan

PURPOSE

Reports of previous studies using excretory urography indicate that significant numbers of new scars developed in 5 to 31% of cases and scarring progressed in 11 to 16% after antireflux surgery. We evaluated renal scarring after surgery using a more accurate method, that is dimercapto-succinic acid renal scintigraphy.

MATERIALS AND METHODS

Between 1985 and 1997 antireflux surgery was performed for primary vesicoureteral reflux in 223 children at our hospital. Of these patients 45 boys and 29 girls with a median age of 74 months at surgery in whom preoperative and postoperative renal scans were available form the basis of our retrospective study. Renal scan was performed 0.3 to 58 months (median 2) preoperatively and 5.3 to 44 months (median 18.7) postoperatively. A total of 24 children (39 renal units) were followed further by additional scanning for as long as 25 to 120 months (median 43.2) postoperatively. Each scan was blindly reviewed for the size, number and zone location of cortical defects based on morphology. Interval changes were grouped into categories as improved, no change, progressed and new scar formation.

RESULTS

Postoperatively there was no ureteral obstruction. Pyelonephritis developed in 2 patients (2.7%) and asymptomatic bacteriuria was noted in 35 (47.3%) postoperatively. Of the renal units 110 (86.6%) showed no change, while 15 (11.8%) were improved and 2 (1.6%) had progression. In no case was new renal scar formation observed.

CONCLUSIONS

Contrary to most previous reports involving excretory urography, our results indicate no significant progression of renal scarring after antireflux surgery. In most cases postoperative followup renal scans demonstrated no significant morphological change. When there was change, it mostly involved the disappearance or decrease of renal scars.

A randomized Phase II study of interleukin-2 with and without beta-interferon for patients with advanced non-small cell lung cancer: an Eastern Cooperative Oncology Group study (PZ586)

Interleukin-2 (IL-2) and beta-interferon (beta-IFN) are biologic agents with antitumor activity observed in preclinical models. Some studies of patients with advanced non-small cell lung cancer treated with IL-2 report relatively long survival, despite low response rates. Seventy-six evaluable patients with stage IV non-small cell lung cancer were treated in a randomized Phase II study with either IL-2 alone or IL-2 plus beta-IFN. Patients received either IL-2 at 6 x 10(6) Cetus units/m2 3 days weekly or the combination of IL-2 at 5 x 10(6) Cetus units/m2 plus beta-IFN at 6 x 10(6) units/m2, both given 3 days weekly. Both biologic agents were administered by intravenous bolus injection on an outpatient basis. Objective responses were observed in 3/76 (4%)) patients. Grade 4 toxicity occurred in 3/39 patients treated with IL-2 alone, and in 4/37 patients treated with IL-2 plus beta-IFN. An additional lethal respiratory toxicity occurred in a patient who received IL-2 plus beta-IFN. The median survival of all patients treated on this study was 33 weeks. Despite producing only a 4% objective response rate. IL-2 appears to have a favorable impact on survival comparable to chemotherapy. The role for this immune therapy in the management of non-small cell lung cancer requires further study.

Nitric oxide protects PC12 cells from serum deprivation-induced apoptosis by cGMP-dependent inhibition of caspase signaling

Although nitric oxide (NO) induces neuronal cell death under some conditions, it also can prevent apoptosis resulting from growth factor withdrawal. We investigated the molecular mechanism by which NO protects undifferentiated and differentiated PC12 cells from trophic factor deprivation-induced apoptosis. PC12 cells underwent apoptotic death in association with increased caspase-3-like activity, DNA fragmentation, poly(ADP-ribose) polymerase (PARP) cleavage, and cytochrome c release after 24 hr of serum withdrawal. The apoptosis of PC12 cells was inhibited by the addition of NO-generating donor S-nitroso-N-acetylpenicillamine (SNAP) (5-100 microM) and the specific caspase-3-like protease inhibitor Ac-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-cho) but not the YVADase (or caspase-1-like protease) inhibitor N-acetyl-Tyr-Val-Ala-Asp-aldehyde (Ac-YVAD-cho). SNAP and Ac-DEVD-cho prevented the increase in DEVDase (caspase-3-like protease) activity. The SNAP-mediated suppression of DEVDase activity was only minimally reversed by the incubation of cell lysate with dithiothreitol, indicating that NO did not S-nitrosylate caspase-3-like proteases in PC12 cells. Western blot analysis showed that NO inhibited the proteolytic activation of caspase-3. The cGMP analog 8-bromo-cGMP (8-Br-cGMP) blocked apoptotic cell death, caspase-3 activity and activation, and cytochrome c release. The soluble guanylyl cyclase inhibitor 1-H-oxodiazol-[1,2,4]-[4,3-a] quinoxaline-1-one (CODQ) significantly attenuated NO-mediated, but not 8-Br-cGMP-dependent, inhibition of apoptotic cell death, PARP cleavage, cytochrome c release, and DEVDase activity. Furthermore, the protein kinase G inhibitor KT5823 reversed both SNAP- and 8-Br-cGMP-mediated anti-apoptotic events. All these apoptotic phenomena were also suppressed by NO production through neuronal NO synthase gene transfer into PC12 cells. Furthermore, similar findings were observed in differentiated PC12 cells stimulated to undergo apoptosis by NO donors and NGF deprivation. These findings indicate that NO protects against PC12 cell death by inhibiting the activation of caspase proteases through cGMP production and activation of protein kinase G.

Carbachol-induced sustained tonic contraction of rat detrusor muscle

OBJECTIVE

To investigate the underlying contractile mechanism of the sustained tonic contraction (SuTC) induced by repetitive carbachol application in rat detrusor muscles.

MATERIALS AND METHODS

Longitudinal muscle strips with no mucosa were obtained from the anterior wall of the urinary bladder in 12-week-old Sprague-Dawley rats. Carbachol (5 micromol/L) was applied repetitively to induce SuTC. The carbachol-induced SuTC was assessed in the presence of various Ca2+-channel blockers and drugs affecting intracellular Ca2+ concentration.

RESULTS

The first application of carbachol elicited a large phasic contraction followed by a tonic contraction (TC); the carbachol-induced contraction was completely reversed by washing out the solution. However, the initial phasic contraction was not reproduced after a second or further application of carbachol. There was consistently only a SuTC with no phasic contraction. The amplitude of the SuTC was 85% of the TC induced by the first carbachol application. The application of atropine (1 micromol/L) to the bath completely blocked SuTC. The carbachol-induced SuTC was insensitive to nicardipine (5 micromol/L) and extracellular polyvalent cations (1 mmol/L, La3+, Co2+, Cd2+, Ni2+ ). Moreover, a similar SuTC was induced even after the complete elimination of extracellular Ca2+ by adding 2 mmol/L EGTA to the Ca2+-free Tyrode solution. To exclude intracellular Ca2+ sources related to the sarcoplasmic reticulum (SR), the effects of SR Ca2+ pump inhibitors, cyclopiazonic acid (CPA, 10 micromol/L) and thapsigargin (0.5 micromol/L) were tested. The carbachol-induced SuTC was insensitive to pretreatment with CPA and/or thapsigargin. To deplete the ryanodine-sensitive Ca2+ pool, muscle strips were repetitively stimulated with caffeine (10 mmol/L) in the presence of 10 micromol/L ryanodine, which did not affect the carbachol-induced SuTC.

CONCLUSIONS

Although the characteristics of the carbachol-induced SuTC have not been defined, these results show that a significant proportion of the carbachol-induced contraction in rats is contributed by the SuTC, which is present even in the complete absence of external Ca2+. The SuTC was not affected by limiting the contributions of internal Ca2+ sources. This suggests that the SuTC in rat bladders is unrelated to known Ca2+ mobilization mechanisms.

Congenital intraorbital optic nerve cyst. Case report

Congenital cystic lesions of the optic nerve are exceedingly rare; only one case is reported in the world literature. The authors describe a case of congenital simple glial cyst in the intraorbital portion of the optic nerve with a brief review of the literature and comment on its histogenesis. A 45-day-old male infant was admitted to the hospital because of progressive proptosis and hypotropia in the left eye, which had been present since birth. Magnetic resonance imaging of the left orbit revealed an ovoid, well-demarcated, homogeneous cystic mass in the intraconal retrobulbar area. The mass compressed the left eyeball with downward and lateral displacement. The wall of the cystic mass was very thin, and a needle puncture of the cyst released clear, colorless, watery fluid. The cystic wall was lined by loose astroglial nerve fibers with some scattered glial cells.

The nitric oxide-producing activities of Scutellaria baicalensis

Scutellaria baicalensis (SB) has antibacterial and antiviral activities. Nitric oxide (NO) as a potent macrophage-derived effector molecule against a variety of bacteria, viruses and tumors has received increasing attention. The objective of this study was to determine the effect of SB on the production of NO. Stimulation of mouse peritoneal macrophages with SB after the treatment of recombinant interferon-gamma (rIFN-gamma) resulted in the increased NO production. SB had no effect on NO production by itself. When SB was used in combination with rIFN-gamma, there was a marked cooperative induction of NO production in a dose-dependent manner. The optimal effect of SB on NO production was shown 6 h after treatment with rIFN-gamma. NO production by SB was inhibited by N(G)-monomethyl-L-arginine. The increased production of NO from rIFN-(gamma) plus SB-stimulated cells was decreased by the treatment of protein kinase C inhibitor such as staurosporin. In addition, synergy between rIFN-gamma and SB was mainly dependent on SB-induced tumor necrosis factor-alpha (TNF-alpha) secretion. All the preparations of SB were endotoxin free. These results suggest that the capacity of SB to increase NO production from rIFN-gamma-primed mouse peritoneal macrophages is the result of SB-induced TNF-gamma secretion.

Interferon-gamma- and interleukin-4-targeted gene therapy for atopic allergic disease

Two cytokines, interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), which play critical roles in the regulation of serum IgE level by directing the interplay of T helper (Th)1 and Th2 cells, were chosen as targets for gene therapy. Anti-allergic activity was evaluated by determining the serum IgE level, and the functional status of each helper T cell was monitored by the serum concentrations of IgG1 and IgG2a. Experimental animals (BALB/c mice) were divided into four groups: the control group; the ovalbumin (OVA) group; the IFN-gamma group; and the IL-4 group. The control group was injected with saline and the OVA group with OVA-alum. The IFN-gamma and IL-4 groups were treated with OVA-alum plus the cDNAs of mouse IFN-gamma and IL-4 in an expression vector. These treatments were applied intramuscularly on a monthly basis for 4 months. OVA-alum treatment significantly increased the serum IgE and IgG1 concentrations, but did not affect IgG2a. Concomitant treatments with the cDNA of IFN-gamma or IL-4 returned the serum IgE almost to the control level and significantly suppressed the OVA-induced increase of IgG1. IFN-gamma cDNA increased the serum IgG2a but IL-4 cDNA had no affect. These results suggest that IFN-gamma inhibited the OVA-induced IgE production by suppressing the Th2 pathway and by enhancing the Th1 pathway. Administration of IL-4 cDNA suppressed the OVA-induced enhancement of IgE production by inhibiting the Th2 pathway rather than by potentiating it.

Selection of RAPD marker for growth of seedlings at low temperature in rice

We have developed a polymerase chain reaction (PCR)-based assay that could effectively reduce the time period required to screen and select the cold tolerance gene of rice seedlings under field conditions. The two specific random amplified polymorphic DNA (RAPD) fragments for the assay were identified on the basis of quantitative trait loci (QTL) analysis which were found to be tightly linked to cold sensitivity. The two RAPD fragments, OPT8(600) in the cold sensitivity rice cultivar 'Dular (indica)' and OPU20(1200) in the resistance rice cultivar 'Toyohatamochi (japonica)', were identified after screening 11 RAPD fragments using 2 random primers on the genomic DNAs of 'Dular' and 'Toyohatamochi'. These primers, when used in a multiplexed PCR, specifically amplified a 0.6 kb and a 1.2 kb fragment in the sensitive and resistant rice cultivars, respectively. When this assay was performed on the genomic DNAs of 16 japonica, 3 Tongil (indica/ japonica), and 2 indica rice cultivars, the primers amplified a 0.6 kb fragment in all of the cold sensitivity rice cultivars or 1.2 kb fragment in all of the resistance ones. These markers can be of potential use in the marker-assisted selection (MAS) for cold tolerance in rice seedling. As screening for resistance can now be conducted independent of the availability of low temperature, the breeding of cold tolerance cultivars can be hastened.

Activation of Fc epsilon RI inhibits the pyruvate kinase through direct interaction with the gamma-chain

The downstream signaling components of high-affinity IgE receptor (FcepsilonRI) were studied using yeast two-hybrid screening of the cDNA library constructed from RBL-2H3 cells. The cytoplasmic part of the gamma-chain but not that of the beta-chain was found to interact with pyruvate kinase in the yeast. The in-vitro-translated pyruvate kinase also specifically interacted with the bacterially expressed glutathione-S transferase fusion protein of the cytoplasmic part of the gamma-chain. When RBL-2H3 cells were challenged with antigen, the activity of pyruvate kinase gradually decreased, reaching the minimum activity around 5 min after the activation, and then slowly returned to the normal level. The dose-response curve (antigen vs. pyruvate kinase activity) plotted at 5 min after stimulation showed that the pyruvate kinase was dose-dependently inhibited and the maximum inhibition was reached at the concentration of 0.1 microgram/ml of antigen. Direct interaction between FcepsilonRI and pyruvate kinase was also demonstrated by co-immunoprecipitation in RBL-2H3 cells. These data suggest that pyruvate kinase is functionally linked with FcepsilonRI and might exert an important role in controlling cellular functions following the activation of FcepsilonRI.

Anti-allergic actions of the leaves of Castanea crenata and isolation of an active component responsible for the inhibition of mast cell degranulation

The anti-allergic actions of the leaves of Castanea crenata (Fagaceae) were studied. The water extract demonstrated potent anti-allergic actions in in vivo and in vitro experiments. The oral or intraperitoneal administration of the extract (100 or 200 mg/kg) caused a significant inhibition of the 48 hr-PCA (up to 90%) and the vascular permeability induced by histamine or serotonin in rats (about 80%). The anaphylactic release of beta-hexosaminidase from RBL-2H3 cells was also significantly inhibited by the extract in a dose-dependent manner with an IC50 value of 230 microg/ml. The activity-guided fractionation of the extract, based on the determination of inhibitory effect upon the release of beta-hexosaminidase, led to the isolation of quercetin as an active principle responsible for the inhibition of degranulation.