Glomerulus-specific mRNA transcripts and proteins identified through kidney expressed sequence tag database analysis

The kidney glomerulus plays a crucial role in blood filtration but the molecular composition and physiology of the glomerulus is not well understood. We previously constructed and large-scale sequenced four mouse glomerular expressed sequence tag (EST) libraries from newborn and adult mouse glomeruli. Here, we compared glomerular EST profiles with whole kidney EST profiles, thereby identifying 497 transcripts corresponding to UniGene clusters that were glomerulus-enriched, that is expressed more abundantly in glomeruli than in whole kidney. These include several known protein-coding glomerulus-specific transcripts critical for glomerulus development and function, but also a large number of gene transcripts, which have not previously been shown to be expressed in the glomerulus, or implicated in glomerular functions. We used in situ hybridization to demonstrate glomerulus-specific RNA expression for six novel glomerular genes and the public Human Protein Atlas to verify glomerular protein expression for another two. The higher mRNA abundance for the eight genes in glomeruli compared with whole kidney was also verified by Taqman quantitative polymerase chain reaction. We surmise that the further characterization of these genes and proteins will increase our understanding of glomerular development and physiology.

Second primary cancer in survivors following concurrent chemoradiation for locally advanced non-small-cell lung cancer

Long-term cancer survivors risk development of second primary cancers (SPC). Vigilant follow-up may be required. We report outcomes of 92 patients who underwent chemoradiation for unresectable stage III non-small-cell lung cancer, with a median follow-up of 8.9 years. The incidence of SPC was 2.4 per 100 patient-years (95% confidence interval: 1.0–4.9).

Analysis of MxA, IL-4, and IRF-1 genes in Filipino patients with subacute sclerosing panencephalitis

BACKGROUND

Subacute sclerosing panencephalitis (SSPE) is a chronic and debilitating disease of the central nervous system caused by a latent measles virus infection. Three candidate genes, MxA, IL-4, and IRF-1 genes were shown to be associated with SSPE in Japanese patients. These genes have been suggested to play a role in the establishment of persistent viral infection in the central nervous system.

SUBJECTS AND METHODS

Sixty Filipino SSPE patients and 120 healthy control subjects were included in the study. Single nucleotide polymorphisms at promoter regions ( IL-4-590C/T and MXA-88G/T) were screened using PCR-RFLP method. Genotyping was done for GT repeat polymorphism within intron 7 of IRF-1.

RESULTS

The TT genotype of MXA, as well as the CT genotype of IL-4, were seen a little more frequently among the SSPE patients as compared to the control subjects. The values though, did not reach statistical significance. IRF-1 analysis did not differ between the two groups.

CONCLUSION

Our study failed to demonstrate a significant association between IL-4, MXA, or IRF-1, and SSPE in the Filipino population. Our results might be explained by a greater contribution of environmental factors such as the socio-economic and nutritional factors in the susceptibility of Filipinos to SSPE other than genetic factors.

Bone‐bonding ability of a hydroxyapatite coated zirconia–alumina nanocomposite with a microporous surface

Using a combination of hydroxyapatite (HA) coating and microporous surface treatment, bone-bonding ability was given to composites of ceria-stabilized tetragonal zirconia and alumina (CZA), which possesses excellent mechanical and wear properties and phase stability. Four types of CZA plates (2 x 10 x 15 mm3) were prepared for this study, which were CZA with a polished surface (group 1), a microporous surface prepared by hydrofluoric acid and heat treatment (group 2), a microporous surface with a submicron HA coating prepared by alternately soaking the plate from group 2 in aqueous CaCl2/HCl and Na2HPO4 solutions (group 3), and a microporous surface with a 4-microm HA coating prepared by the biomimetic method, where the plates from group 3 were soaked in simulated body fluid (group 4). Plates were implanted into rabbit tibia, and after 4, 8, and 16 weeks, tensile testing and histological examination of the bone-implant interface were conducted. At 4 weeks, group 4 had superior bone-bonding ability compared with other implants, which was maintained at the later postimplantation times. This HA-coated CZA with a microporous surface has the possibility of clinical use as a bearing material in cementless joint prostheses or as a load-bearing bone substitute.

Association study of polymorphisms in SOCS family genes with type 1 diabetes mellitus

Suppressors of cytokine signalling (SOCS) proteins play important roles in the negative regulation of cytokine signal. We first searched for polymorphisms in SOCS-1, SOCS-3 and SOCS-5 genes, and examined the association of the polymorphisms with type 1 diabetes (T1D). As a result, we did not find any significant associations between SOCS genes and T1D.

Er81 is expressed in a subpopulation of layer 5 neurons in rodent and primate neocortices

Laminar organization is a fundamental cytoarchitecture in mammalian CNS and a striking feature of the neocortex. ER81, a transcription factor, has recently been utilized as a marker of cells in the layer 5 of the neocortex. We further pursued the distribution of ER81 to investigate the identity of the ER81-expressing cells in the brain. Er81 transcript was expressed in a subset of pyramidal cells that were scattered throughout the entire width of layer 5. In the rat cortex, Er81 transcripts were first detected in the ventricular zone at E15, remained expressed in putative prospective layer 5 neurons during infant and juvenile stages. The ER81-expressing subpopulation in adult layer 5 neurons did not segregate with the phenotypes of the projection targets. By retrograde labeling combined with immunohistochemistry or reverse transcription-polymerase chain reaction analysis, we found ER81 expression in nearly all of the layer 5 neurons projecting to the spinal cord or to the superior colliculus, while in only one-third of the layer 5 neurons projecting to the contralateral cortex. Er81 was also detected in layer 5 neurons in a P2 Japanese macaque monkey but not in adult monkey cortices. These findings suggest that a neuron class defined by a molecular criterion does not necessarily segregate with that defined by an anatomical criterion, that ER81 is involved in cell differentiation of a subset of layer 5 projection neurons and that this mechanism is conserved among rodents and primates.

Functional MxA promoter polymorphism associated with subacute sclerosing panencephalitis

BACKGROUND

The antivirally active MxA protein is induced by interferon (IFN) alpha/beta and inhibits the replication of single-stranded RNA viruses including measles virus (MV). The authors investigated whether the MxA gene contributed to the development of subacute sclerosing panencephalitis (SSPE) in Japanese individuals.

METHODS

Single-nucleotide polymorphisms (SNP) in the promoter region of the MxA gene were screened, association studies were performed between two SNP and SSPE, and then a functional difference in the promoter activities of the two SNP was investigated by a dual luciferase reporter assay.

RESULTS

Four SNP were found (-88 G/T, -123 C/A, -200 T/C, and -213 G/T), and SSPE patients exhibited a higher frequency of both the -88T allele and the -88TT genotype than controls (p = 0.040 and 0.003). The IFN-induced up-regulation of the MxA promoter activity of the sequence with -88T was found to be significantly higher than that with G.

CONCLUSIONS

MxA promoter -88 G/T SNP may confer host genetic susceptibility to SSPE in Japanese individuals. The finding that homozygotes of the MxA -88T allele with a high MxA-producing capability were more frequently seen in SSPE patients suggests that the MxA protein promotes the establishment of persistent MV infection of neural cells.

Preoperative concurrent chemoradiotherapy with cisplatin and docetaxel in patients with locally advanced non-small-cell lung cancer

The objective of this study was to assess the feasibility and effectiveness of an induction chemoradiotherapy regimen followed by surgery in patients with locally advanced non-small-cell lung cancer (LA-NSCLC). A total of 22 patients with LA-NSCLC were treated with induction chemoradiotherapy consisting of cisplatin (40 mg m⁻²) and docetaxel (40 mg m⁻²) given on days 1, 8, 29 and 36 plus concurrent thoracic irradiation at a dose of 40–60 Gy (2 Gy fraction⁻¹ day⁻¹). Surgical resection was performed within 6 weeks after completion of induction therapy. Objective response to the induction therapy was obtained in 16 patients (73%). In all, 20 patients (91%) underwent surgery and complete resection was achieved in 19 patients (86%). Pathological downstaging and pathological complete response were obtained in 14 (64%) and five (23%) patients, respectively. With a median follow-up period of 32 months, the calculated 3-year overall and progression-free survival rates were 66 and 61%, respectively. It is noteworthy that the 3-year overall survival rate in 14 patients achieving pathological downstaging was extremely high (93%). Toxicity was manageable with standard approaches. No treatment-related deaths occurred. This combined modality treatment is feasible and highly effective in patients with LA-NSCLC. The results warrant further large-scale study to confirm the effectiveness of this regimen.

Phase I/II study of docetaxel and cisplatin with concurrent thoracic radiation therapy for locally advanced non-small-cell lung cancer

Recent studies have suggested the superiority of concomitant over sequential administration of chemotherapy and radiotherapy. Docetaxel and cisplatin have demonstrated efficacy in advanced non-small-cell lung cancer (NSCLC). This study evaluated the safety, toxicity, and antitumour activity of docetaxel/cisplatin with concurrent thoracic radiotherapy for patients with locally advanced NSCLC. Patients with locally advanced NSCLC (stage IIIA or IIIB), good performance status, age <or=75 years, and adequate organ function were eligible. Both docetaxel and cisplatin were given on days 1, 8, 29, and 36. Doses of docetaxel/cisplatin (mg m(-2)) in the phase I study portion were escalated as follows: 20/30, 25/30, 30/30, 30/35, 30/40, 35/40, 40/40, and 45/40. Beginning on day 1 of chemotherapy, thoracic radiotherapy was given at a total dose of 60 Gy with 2 Gy per fraction over 6 weeks. In the phase I portion, the maximum tolerated doses (MTD) among 33 patients were docetaxel 45 mg m(-2) and cisplatin 40 mg m(-2). The major dose-limiting toxicity (DLT) was radiation oesophagitis. The recommended doses (RDs) for the phase II study were docetaxel 40 mg m(-2) and cisplatin 40 mg m(-2). A total of 42 patients were entered in the phase II portion. Common toxicities were leukopenia, granulocytopenia, anaemia, and radiation oesophagitis, with frequencies of grade >or=3 toxicities of 71, 60, 24, and 19%, respectively. Toxicity was significant, but manageable according to the dose and schedule modifications. Dose intensities of docetaxel and cisplatin were 86 and 87%, respectively. Radiotherapy was completed without a delay in 67% of 42 patients. The overall response rate was 79% (95% confidence interval (CI), 66-91%). The median survival time was 23.4+ months with an overall survival rate of 76% at 1 year and 54% at 2 years. In conclusion, chemotherapy with cisplatin plus docetaxel given on days 1, 8, 29, and 36 and concurrent thoracic radiotherapy is efficacious and tolerated in patients with locally advanced NSCLC and should be evaluated in a phase III study.

The effect of various chemotherapeutic agents given with mild hyperthermia on different types of tumours

It has been shown that hyperthermia can enhance the cytotoxicity of some chemotherapeutics. However, the most effective agent(s) at elevated temperatures have yet to be determined. A previous study suggests that the drug of choice at elevated temperatures may be different from that at the physiological temperature, and that the alkylating agents may be most effective at elevated temperatures. To further investigate these possibilities, the effect of chemotherapeutic agents were compared. These agents were cyclophosphamide, ifosfamide, melphalan, cis-diamminedichloroplatinum (II), 5-fluorouracil, mitomycin C and bleomycin. Three tumours (mammary carcinoma, osteosarcoma and squamous cell carcinoma) were used. They were transplanted into the feet of C3H/He mice. When tumours reached 65 mm(3), a test agent was injected intraperitoneally. Tumours were immediately heated at 41.5 degrees C for 30 min, and the tumour growth (TG) time was studied for each tumour. Using the TG times, the TG-50 (the time required for one-half of the total number of the treated tumours to reach the volume of 800 mm(3) from 65 mm(3)) was calculated. Subsequently, the tumour growth delay time (GDT) and the thermal enhancement ratio (TER) were obtained. The GDT was the difference between the TG-50 of treated tumours and that of non-treated control tumours. The TER was the ratio of the GDT of a group treated with an agent at 41.5 degrees C to that of a group treated with the agent at room temperature. Results showed that the top three effective agents tested at 41.5 degrees C were solely alkylating agents--CY, IFO and L-PAM--for each kind of tumour. A GDT of cisplatin was smaller than those of the alkylating agents. The smallest TER, 1.1, was observed for 5-fluorouracil, which was given for mammary carcinoma, and for mitomycin C, which was given for squamous cell carcinoma. It could be concluded that the alkylating agents at elevated temperatures might be the drugs of choice for many types of tumours. The possible mechanisms of thermal enhancement associated with these agents are discussed.

Effect of dietary control on plasma nitrate level and estimation of basal systemic nitric oxide production rate in humans

It is of great interest and value to evaluate the systemic nitric oxide (NO) production rate in humans under various conditions. However, the currently available estimation methods are troublesome and time-consuming. We thus aimed at developing a simple method to estimate the basal systemic NO production rate in humans based on a steady-state analysis, i.e., a balance between the systemic NO production rate and the total nitrate elimination rate. Plasma nitrate concentrations of young healthy volunteers (n = 7 in group 1: n = 9 in group 2) were measured for 2 days. In group 1, all subjects had the same meals for 7 days prior to the plasma nitrate measurement. In group 2, all subjects were allowed free diets. The plasma nitrate concentrations were highly influenced by dietary nitrite/nitrate intake in both groups and reached the steady-state levels after 14-h fasting. Accordingly, the basal systemic NO production rates were estimated from the plasma nitrate concentrations after 14-h fasting (group 1, 630 +/- 37 nmol min(-1) = 0.78 +/- 0.03 micromol kg(-1) h(-1); group 2, 597 +/- 45 nmol min(-1) = 0.66 +/- 0.05 micromol kg(-1) h(-1), P = not significant vs group 1). These estimated values were comparable to the values obtained by other methods. In conclusion, the present estimation method with 14-h fasting using a single-compartment analysis was found to be a simple approach to quantitative evaluation and intra- and interindividual comparisons of the basal systemic NO production rates in humans.

Statins as antioxidant therapy for preventing cardiac myocyte hypertrophy

Cardiac hypertrophy is a major cause of morbidity and mortality worldwide. The hypertrophic process is mediated, in part, by small G proteins of the Rho family. We hypothesized that statins, inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase, inhibit cardiac hypertrophy by blocking Rho isoprenylation. We treated neonatal rat cardiac myocytes with angiotensin II (AngII) with and without simvastatin (Sim) and found that Sim decreased AngII-induced protein content, [3H] leucine uptake, and atrial natriuretic factor (ANF) promoter activity. These effects were associated with decreases in cell size, membrane Rho activity, superoxide anion (O2*-) production, and intracellular oxidation, and were reversed with L-mevalonate or geranylgeranylpyrophosphate, but not with farnesylpyrophosphate or cholesterol. Treatments with the Rho inhibitor C3 exotoxin and with cell-permeable superoxide dismutase also decreased AngII-induced O2*- production and myocyte hypertrophy. Overexpression of the dominant-negative Rho mutant N17Rac1 completely inhibited AngII-induced intracellular oxidation and ANF promoter activity, while N19RhoA partially inhibited it, and N17Cdc42 had no effect. Indeed, Sim inhibited cardiac hypertrophy and decreased myocardial Rac1 activity and O2*- production in rats treated with AngII infusion or subjected to transaortic constriction. These findings suggest that statins prevent the development of cardiac hypertrophy through an antioxidant mechanism involving inhibition of Rac1.

The R3 region, one of three major repetitive regions of human herpesvirus 6, is a strong enhancer of immediate-early gene U95

An immediate-early (IE) gene of human herpesvirus 6 (HHV-6), U95, has similarity at the amino acid level to the murine cytomegalovirus (MCMV) IE2 gene and is related to the human cytomegalovirus (HCMV) US22 gene family. Sequence analyses of U95 cDNA clones revealed that the transcription start site was located about 1.6 kbp upstream of the putative initiating ATG and that the transcript consisted of two exons. A single intron extended from nucleotides 142589 to 144229, which contained ORF U94. A protein with a molecular mass of about 120 kDa was translated from this cDNA clone in an in vitro transcription-translation assay. The transcription start site was found to be 220 bp downstream of the R3 region by primer extension analysis. HHV-6 has three repetitive elements, R1, R2, and R3, in or near the IE-A locus. R3 is composed of 24 copies of a 104- to 107-bp sequence element, which contains multiple putative binding sites for cellular transcription factors such as AP2 and NF-kappaB, and its biological significance has yet to be elucidated. The region between -710 and +46 relative to the transcription start site of U95 was analyzed in this study. Deletion from -710 to -396, corresponding to three copies of an R3 unit, decreased the promoter activity by 15-fold, and coexpression of IkappaBalpha(S32A/S36A) repressed it to almost the same level. Electrophoretic mobility shift assays showed that NF-kappaB family members p50 and c-Rel bound to NF-kappaB sites derived from the R3 region. These results demonstrate that R3 strongly enhances the U95 promoter activity and that NF-kappaB and binding sites for NF-kappaB in the R3 region play an important role in its activation. Because U95 promoter activity correlated with the number of R3 units, which each contained an NF-kappaB site, the repetitive organization of R3 is important for regulating U95 transcription.

Pleiotropic effects of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors

The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors or statins are potent inhibitors of cholesterol biosynthesis. Several large clinical trials have demonstrated the beneficial effects of statins in the primary and secondary prevention of coronary heart disease. However, the overall clinical benefits observed with statin therapy appear to be greater than what might be expected from changes in lipid profile alone, suggesting that the beneficial effects of statins may extend beyond their effects on serum cholesterol levels. Indeed, recent experimental and clinical evidence indicates that some of the cholesterol-independent or "pleiotropic" effects of statins involve improving or restoring endothelial function, enhancing the stability of atherosclerotic plaques, and decreasing oxidative stress and vascular inflammation. Many of these pleiotropic effects of statins are mediated by their ability to block the synthesis of important isoprenoid intermediates, which serve as lipid attachments for a variety of intracellular signaling molecules. In particular, the inhibition of small GTP-binding proteins, Rho, Ras, and Rac, whose proper membrane localization and function are dependent on isoprenylation, may play an important role in mediating the direct cellular effects of statins on the vascular wall.

[Relationship between endothelial dysfunction and nitric oxide production in young male smokers]

OBJECTIVES

Endothelial function in the brachial arteries is impaired in smokers. However, little is known about this condition in young adult men. The relationship between nitric oxide(NO) production and the endothelial function was investigated in young smokers and compared with non-smokers.

METHODS

Flow-mediated vasodilation of the brachial artery during reactive hyperemia was examined in 10 young smokers(mean age 31 years) and 12 control subjects(mean age 28 years). The vasodilator response in the brachial artery was measured by ultrasonography, and blood samples were obtained from the right cephalic vein. Blood samples were taken at baseline, 30 sec after cuff deflation, and before and 5 min after 0.3 mg of nitroglycerin administration. Blood flow was calculated by multiplying mean flow velocity and vessel cross-sectional area. Plasma NOx(nitrate + nitrite) levels were measured, and the percentage change of NOx production(delta NOx) was calculated as follows: delta NOx(%) = [(NOx concentration at peak flow-mediated vasodilation or after 0.3 mg nitroglycerin administration) - baseline NOx concentration)] x 100/baseline NOx concentration.

RESULTS

Percentage changes in diameter of the brachial artery, NOx production and delta NOx in response to nitroglycerin were not statistically different between the two groups(smokers: 27.6 +/- 8.0 mumol/l, control subjects: 34.0 +/- 8.7 mumol/l). However, percentage change of flow-mediated vasodilation during reactive hyperemia in the young smokers was significantly smaller than that in the control subjects(4.8 +/- 2.7%, 9.1 +/- 5.3%, respectively, p < 0.05). Moreover, delta NOx during reactive hyperemia in the smokers was significantly smaller than that in the control subjects(388.8 +/- 90.2%, 738.0 +/- 284.5%, respectively, p < 0.05).

CONCLUSIONS

The impaired response to reactive hyperemia in young smokers might be associated with decreases in flow-dependent NO production.

Synthesis of styrenes through the biocatalytic decarboxylation of trans-cinnamic acids by plant cell cultures

A novel method for producing styrenes from trans-cinnamic acids was developed. When trans-cinnamic acid was incubated with plant cell cultures at room temperature, styrene was obtained. 4-Hydroxy-3-methoxystyrene (2a), 3-nitrostyrene (2f) and furan (2g) were synthesized quantitatively.

Enhanced intra-abdominal visceral fat accumulation in patients with Werner's syndrome

OBJECTIVE

Studies were made on the abnormality of glucose and lipid metabolism and its cause in four patients with Werner's syndrome to infer the reason for accelerated atherogenesis in this syndrome.

RESULTS

Of these four patients, hypercholesterolemia was found in three, hypertriglyceridemia in four, hypoalphalipoproteinemia in two and hypertension in two. All the patients had insulin-resistant diabetes mellitus and three of them had apparent hyperinsulinemia. Abdominal computed tomography revealed that all of them had visceral fat obesity, namely augumented intra-abdominal adipose tissue.

CONCLUSION

The clinical features of these patients resemble those recently designated as insulin resistant syndrome (syndrome X) or visceral fat syndrome. The metabolic abnormality may be one of important factors in the accelerated atherogenesis in this syndrome.

Chronic inhibition of nitric oxide synthesis in rats increases aortic superoxide anion production via the action of angiotensin II

OBJECTIVE

Chronic inhibition of nitric oxide (NO) synthesis by Nomega-nitro-L-arginine methyl ester (L-NAME) increases vascular tissue angiotensin II activity and oxidative stress in animals by incompletely understood mechanisms. In a rat model, we investigated the role of local angiotensin II activity in the pathogenesis of increased oxidative stress.

DESIGN

We studied the aortas of control rats and others receiving L-NAME or L-NAME plus an angiotensin II type 1 receptor antagonist (CS-866).

RESULTS

Administration of L-NAME for 7 days significantly increased superoxide anion (O2-) and both immunoreactivity and electrophoretically demonstrable activity of redox-sensitive transcription factors (NF-kappaB and AP-1). Treatment with the angiotensin II type 1 receptor antagonist prevented all of the above changes. The observed effects of the type 1 receptor antagonist was independent of the L-NAME-induced arterial hypertension.

CONCLUSIONS

These findings suggest that chronic inhibition of NO synthesis may increase vascular oxidative stress and oxidative stress-sensitive signals via the action of angiotensin II mediated via type 1 receptors.

An infant with precursor natural killer (NK) cell leukemia successfully treated with an unrelated cord blood transplantation

Here we report a case with precursor natural killer (NK) cell leukemia successfully treated with an unrelated cord blood transplantation. A 7-month-old Japanese boy was diagnosed to have NK cell leukemia based on the existence of abnormal cells in the bone marrow with the phenotype of CD3(-) /CD4(+) /CD7(-) /CD8(-) /CD16(-) /CD33(+) /CD34(-) /CD56(+) /HLA-DR(+) /NKB1(+) / CD94(+). The leukemic cells showed few azurophilic granules in the cytoplasm and weak cytotoxic activity. Although he presented with a huge mass occupying the bilateral paranasal sinuses and hepatosplenomegaly, he achieved complete remission by the conventional chemotherapeutic regimen for acute myelogenous leukemia, followed by an unrelated cord blood transplantation. He has remained in complete remission for 14 months posttransplant. To our knowledge, this is the youngest reported case with precursor NK cell leukemia; cord blood transplantation may thus be the treatment of choice for this disease.

Diagnostic usefulness of diffusion-weighted magnetic resonance imaging in influenza-associated acute encephalopathy or encephalitis

A magnetic resonance imaging (MRI) study was performed for a 20-month-old girl with an influenza type A infection who presented acute encephalopathy. Conventional MRI performed 8 days after the onset of encephalopathy, including T1-weighted, T2-weighted, and fluid-attenuated inversion recovery imaging, revealed only vague lesions in the right frontal, temporal, and parietal lobes. In contrast, diffusion-weighted imaging (DWI) then demonstrated the lesions much more intensively. On the 26th day, the lesions previously observed on DWI had become less discernible. The hyperintensity observed on DWI might reflect cytotoxic edema. Thus, DWI may be useful for evaluation of acute influenzal encephalopathy/encephalitis.

Decrease of nitric oxide end-products during coronary circulation reflects elevated basal coronary artery tone in patients with vasospastic angina

The aim of this study was to investigate the role of nitric oxide (NO) in the coronary circulation and its relation to basal coronary artery tone in patients with vasospastic angina (VSA). We evaluated the level of nitric oxide end-products (NOx; nitrite + nitrate) in coronary circulation blood using an HPLC-Griess system for nine patients with VSA and nine control patients. All of the patients with VSA experienced focal spasm in the proximal to middle segments of the left anterior descending coronary artery (LAD) in response to intracoronary injection of ergonovine maleate. The luminal diameter of the coronary artery was measured in each patient by quantitative coronary arteriography. Blood samples for NOx measurement were obtained from the coronary sinus (NOxV) and the ostium of the left coronary artery (NOxA). The NOx difference, calculated from the coronary venous-arterial difference in NOx, was close to zero for the control patients whereas it was clearly negative for the patients with VSA. In addition, the NOx difference in the patients with VSA showed a negative correlation with basal coronary artery tone (r = -0.91, p < 0.01) and a positive correlation with the dose of ergonovine required for spasm provocation (r = 0.77, p < 0.05). These results indicate that increased basal coronary artery tone and higher susceptibility to ergonovine in patients with VSA would be a consequence of coronary endothelial dysfunction as is indicated by NOx.

Inhibition of in vitro fertilization of mouse gametes by sulfated sialic acid polymers

The effect of sialic acid (N-acetyl neuraminic acid), sialic acid dimer, sialic acid polymers (colominic acid) and sulfated colominic acid on the activity of hyaluronidase, on the dispersion of cumulus cells by mouse sperm and on in vitro mouse fertilization (sperm penetration of zona pellucida) were evaluated. Bovine testicular hyaluronidase activity was significantly inhibited by colominic acid and sulfated colominic acid, but not by sialic acid and its dimer. The dispersion of cumulus cells from eggs by mouse sperm was also inhibited by colominic acid and sulfated colominic acid. In vitro fertilization of mouse gametes was inhibited by sulfated colominic acid. The IC50 value of sulfated colominic acid-induced inhibition of fertilization was 0.3 mg/ml (ca. 0.9 mM). The value changed from 0.9 mM for cumulus-surrounded egg to 1.5 mM for cumulus free-egg. On the other hand, colominic acid showed little or no inhibitory effect on mouse in vitro fertilization at 0.5 mg/ml (ca. 1.6 mM). This antifertility activity by sulfated colominic acid did not appear to be due to an effect on sperm motility or on the oocytes. These results suggest that (1) the cumulus cells surrounding the eggs were dispersed by sperm hyaluronidase, (2) hyaluronidase was inhibited by colominic acid and by sulfated colominic acid, (3) sulfated colominic acid inhibits sperm penetration of zona pellucida by the inhibition of hyaluronidase and/or some enzymes required for mouse gametes fertilization.

Characterization of human herpesvirus 7 U27 gene product and identification of its nuclear localization signal

A monoclonal antibody, 5H4, that recognizes human herpesvirus 7 (HHV-7) was used in Western analysis to probe HHV-7-infected SupT1 cells. This antibody recognizes a 40-kDa virus-specific polypeptide that is expressed in the absence of viral DNA synthesis. By screening a lambdagt11 HHV-7 cDNA library, the gene encoding the protein was identified as the U27 open reading frame previously reported [J. Virol. (1996) 70, 5975-5989]. Immunofluorescent studies showed a punctate nuclear localization of the protein in both HHV-7-infected cells and transfected cells. A computer program predicted two classic nuclear localization signals (NLSs) in the middle and C-terminal regions of the protein. A C-terminal deletion mutant of the protein could not enter the nucleus, whereas green fluorescent protein or maltose binding protein fused to the C-terminal region of the protein was transported into the nucleus. These findings demonstrate that the predicted C-terminal, but not middle, NLS of the protein actually function as NLS. In addition, nuclear transport of a maltose binding protein-fusion protein containing the C-terminal NLS of the U27 protein was inhibited by both wheat germ agglutinin and a Q69L Ran-GTP mutant, indicating that the U27 protein is transported into the nucleus from the cytoplasm by means of classic nuclear transport machinery. Interestingly, this NLS motif is highly conserved at the C-termini of all herpesvirus DNA polymerase processivity factors that have been examined.

Microcapsulated parathyroid tissue in vitro

Ideally, microcapsules will make it possible to transplant parathyroid tissue for allo- and xenotransplantation in hypoparathyroid patients. In this study, parathyroid tissues capsulated by polyelectrolyte complex were evaluated in vitro. Hormone secretion ability was significantly (P < 0.001) greater in sediment than in supernatant. There was no difference in hormone secretion ability between the parathyroid tissue thawed at room temperature and the tissue thawed in a bath at 37 degrees C. Both non-capsulated and capsulated parathyroid tissues were incubated for three weeks. The ability of capsulated parathyroid to secrete hormones in vitro was reduced gradually and disappeared within three weeks. There are still several problems to be solved before the clinical application of parathyroid allotransplantation using microcapsulation.

Enhanced expression of osteopontin by high glucose. Involvement of osteopontin in diabetic macroangiopathy

Atherosclerotic vascular disease is a major complication of diabetic patients. Osteopontin has recently been implicated in the development of atherosclerosis. In the present study, we have investigated the effects of high glucose on expression of osteopontin in cultured rat aortic smooth muscle cells. High concentrations of glucose increased osteopontin secretion from the cells, and the increased secretion was completely inhibited by an inhibitor of protein kinase C, GF109203X. Northern blot analysis confirmed the enhanced effect of glucose on expression of osteopontin mRNA. Promoter activity of osteopontin, measured using the osteopontin promoter/luciferase expression vector system, was increased by high glucose, and the enhanced effect was completely inhibited by GF109203X. Glucosamine also increased the promoter activity of osteopontin. Azaserine, an inhibitor of glutamine:fructose-6-phosphate amidotransferase, the key enzyme of the hexosamine pathway, profoundly inhibited high glucose-mediated increase in the promoter activity. Taken together, these data indicate that high glucose enhances the expression of osteopontin at the transcriptional level possibly through the activation of protein kinase C as well as the hexosamine pathway. Our results suggest that osteopontin could play a role in the development of diabetic vascular complications.

Differential interaction of CrkII adaptor protein with platelet-derived growth factor alpha- and beta-receptors is determined by its internal tyrosine phosphorylation

CrkII is an intracellular adaptor protein involved in signal transduction by various growth factors. Activation of PDGF alpha-receptor resulted in its association with CrkII in vivo. In contrast, binding of CrkII to the PDGF beta-receptor was negligible, despite its becoming prominently phosphorylated. Bacterially expressed GST-CrkII SH2 domain specifically bound to Tyr-762 and Tyr-771 in the activated PDGF alpha- and beta- receptors, respectively. GST fusion protein of full-length CrkII also bound to the activated PDGF beta-receptor. However, tyrosine phosphorylation of GST-CrkII diminished its binding to the beta-receptor. CrkI, a truncated version of CrkII lacking the phosphorylatable tyrosine residue, could bind to both PDGF alpha- and beta-receptors in vivo. In conclusion, tyrosine phosphorylation of CrkII negatively affects its binding to the PDGF receptors. The differential binding of CrkII to the PDGF alpha- and beta- receptors may be a rationale for functional diversity between the two receptors.

Interpolation of missing part of human follicle border on ultrasonic B-mode image by iterative revision

In clinical infertility treatments, assessment of ovarian follicle growth by ultrasonography is important. In order to measure the geometrical characteristics of the human follicle, such as the area of the cross-sectional image and the volume inside the follicle, a method based on manual tracing of the follicle contour from the ultrasonic B mode image is widely used. However, the observable ultrasonic B mode images are sometimes imperfect and some parts of the follicle border are missing due to the existence of the acoustic shadow. In this paper, a method that interpolates the missing part of the follicle border from the known part is proposed. This method uses a priori information of the follicle, which is usually known in actual cases: (1) the follicle's surface is so smooth that its border is assumed to be a smooth closed curve; and (2) the position of the follicle's center is roughly predicted in advance in the ultrasonic B-mode image. In the proposed method, the missing part of the human follicle border is interpolated from the known part by applying an iterative revision so as to satisfy the smoothness condition of the follicle. This method is also applied to three-dimensional image reconstruction of the human follicle.

Enhanced expression of osteopontin in human diabetic artery and analysis of its functional role in accelerated atherogenesis

We have previously reported that high glucose stimulates osteopontin (OPN) expression through protein kinase C-dependent pathways as well as hexosamine pathways in cultured rat aortic smooth muscle cells. The finding prompted us to study in vivo expression of OPN in diabetes mellitus. In the present study, we found by immunohistochemistry that medial layers of the carotid arteries of streptozotocin-induced diabetic rats and the forearm arteries of diabetic patients stained positively for OPN antibodies, whereas the staining from arteries of control rats and nondiabetic patients was negative. We also found that OPN stimulated the migration and enhanced platelet-derived growth factor (PDGF)-mediated DNA synthesis of cultured rat aortic smooth muscle cells. OPN and PDGF synergistically activated focal adhesion kinase as well as extracellular signal-regulated kinase; this finding seems to explain the OPN-induced enhancement of PDGF-mediated DNA synthesis. Taken together, our present results raise a possibility that OPN plays a role in the development of diabetic vascular complications.

[Effects of aging and hyperlipidemia on plasma osteopontin level]

In order to elucidate a possible mechanism for accelerated atherogenesis as well as enhanced vascular calcification observed during the normal aging process, we measured plasma osteopontin (OPN) levels and examined their relation to aging and certain disease parameters. In all cases examined, no significant relation was found between the plasma OPN level and age, body mass index, blood pressure, plasma levels of glucose and insulin, serum levels of creatinine, triglyceride, and high density lipoprotein cholesterol. On the other hand, a significant negative correlation was found between the plasma OPN level and serum total cholesterol concentration (n = 78, r = -0.355, p = 0.0014). The serum level of low density lipoprotein (LDL) cholesterol, calculated by the formula of Friedewald, also showed a significant negative correlation to the plasma OPN level (n = 78, r = -0.301, p = 0.0075). In cases without diabetes mellitus and hypertension, a significant positive correlation was found between the plasma OPN level and age (n = 22, r = 0.445, p = 0.0378). It is postulated that OPN plays a negative regulatory role in the development of vascular calcification. Therefore, the observed negative relationship between the plasma OPN level and the serum levels of total cholesterol and LDL cholesterol, suggests a possibility that hypercholesterolemia facilitates vascular calcification by suppressing OPN synthesis. On the other hand, in non-diabetic and normotensive cases, the positive relationship between the plasma OPN level and age may reflect a defense mechanism against age-related increase of vascular calcification.

Increase in circulating levels of monocyte chemoattractant protein-1 with aging

Monocyte chemoattractant protein-1 (MCP-1) is a member of chemokines with chemoattractant activity for monocytes, T cells, mast cells, and basophils. Precursor mRNA or protein was detected at high levels in the lesions of several diseases, such as pulmonary fibrosis, rheumatoid arthritis, atherosclerosis, and some types of tumors. The regulation of MCP-1 production and the role of this chemokine in pathophysiologic states, however, remain largely unknown. In this study, using an enzyme-linked immunosorbent assay (ELISA), we measured the circulating MCP-1 levels in 405 healthy Japanese subjects of various ages, eliciting a profound age-dependent MCP-1 increase. Multivariate regression analysis revealed that significant predictors of MCP-1 value for males were age (p = 0.033) and serum triglyceride (p = 0.039). For females, age was also a significant predictor (p = 0.00002). One possible explanation is that the plasma MCP-1 concentration might reflect the existence of atherosclerosis, although the plasma MCP-1 concentration from patients with coronary artery disease or cerebrovascular accidents appears not to differ from age-matched, disease-free controls. This is the first report linking an increase in a particular chemokine level with aging.

Cepharanthin enhances thermosensitivity without a resultant reduction in the thermotolerance of a murine mammary carcinoma

Cepharanthin (Ce) is a biscoclaurine alkaloid extracted from Stephania cepharantha Hayata. The results of our previous in vitro study indicated that Ce reduces thermotolerance by enhancing thermosensitivity. In the present study, we investigated the in vitro and in vivo effects of Ce on thermosensitivity and thermotolerance using a murine mammary carcinoma, MCa, and C3H/HeN mice. Ce enhanced the thermosensitivity of MCa cells for heating at 44 degrees C not only in vitro but also in vivo. The in vivo enhancement ratio +/- SD of Ce at 100 mg/kg for heating at 44 degrees C was 1.3+/-0.3. The fractionated heat treatments at 44 degrees C for 30 and 60 min with an interval time of 0-6 days resulted in the development of remarkable thermotolerance and the expression of heat shock protein 70 in MCa tumors after the first heating. Ce at 100 mg/kg given immediately after the first heating increased the expression of heat shock protein 70 in MCa tumors, and did not reduce the development of thermotolerance. Ce given immediately before the first or second heating also did not inhibit the thermotolerance. The results of this study suggest that Ce enhances the thermosensitivity of MCa tumors as a thermosensitizer, but that this mild thermosensitizing property of Ce might be insufficient to conquer the remarkable thermotolerance in MCa tumors that develops after the first heating.

A new experimental system for irradiating tumors in mice using a linear accelerator under specific pathogen-free conditions

We developed a reliable system for the irradiation of xenografted tumors in mice which allows for accurate local irradiation under specific pathogen-free conditions. The system presented here consists of acrylic supports for mice and an acrylic box connected to a pump through 0.22 microns pore-sized filters. Mice with xenotransplanted tumors growing on their right hind legs were set on the supports and put into the box in a laminar flow hood. The tumors of 7 mice were irradiated simultaneously with X-rays of 6 and 10 MV generated by a linear accelerator at a dose rate of 3.1-4.7 Gy/min. The air was ventilated through filters during irradiation in the closed box. Microorganism tests confirmed that no bacteria entered or left the box. One of the significant characteristics of this setup is that it allows for irradiation under conditions of acute hypoxia, which is obtained using an integrated tourniquet. The dose variation among 7 tumors was less than 1%. The rest of the mouse's body was shielded effectively by a half-field technique and a lead block. As a result, the whole body dose for the mice was 0-4% of the total dose absorbed by the tumor. Due to the high dose rate and the ability to irradiate 7 mice simultaneously under specific pathogen-free conditions, this new system can be considered a time-saving and valuable tool for radiation oncology research.

Enhanced expression of osteopontin by high glucose in cultured rat aortic smooth muscle cells

Atherosclerotic vascular disease is a major complication of diabetic patients, and osteopontin has recently been implicated in the development of atherosclerosis. In the present study, we have investigated the effects of high glucose on expression of osteopontin in cultured rat aortic smooth muscle cells. High concentrations of glucose increased osteopontin secretion from the cells, and the increased secretion was completely inhibited by an inhibitor of protein kinase C, GF109203X. Northern blot analysis confirmed the enhanced effect of glucose on expression of osteopontin mRNA. Promoter activity of osteopontin, measured using the osteopontin promoter/luciferase expression vector system, was increased by high glucose, and the enhanced effect was completely inhibited by GF109203X. Glucosamine also increased the promoter activity of osteopontin, and azaserine, an inhibitor of glutamine:fructose-6-phosphate amidotransferase (the key enzyme of the hexosamine pathway), profoundly inhibited high glucose-mediated increase in the promoter activity. Taken together, these data indicate that high glucose enhances the expression of osteopontin at the transcriptional level possibly through the activation of protein kinase C as well as the hexosamine pathway. Our results suggest that osteopontin could play a role in the development of diabetic vascular complications.

Platelet-derived growth factor activates p38 mitogen-activated protein kinase through a Ras-dependent pathway that is important for actin reorganization and cell migration

Members of the mitogen activated protein (MAP) kinase family, extracellular signal-regulated kinase, stress-activated protein kinase-1/c-Jun NH2-terminal kinase, and p38, are central elements that transduce the signal generated by growth factors, cytokines, and stressing agents. It is well known that the platelet-derived growth factor (PDGF) activates extracellular signal-regulated kinase, which leads to cellular mitogenic response. On the other hand, the role of the other MAP kinases in mediating the cellular function of PDGF remains unclear. In the present study, we have investigated the functional role of the other MAP kinases in PDGF-mediated cellular responses. We show that ligand stimulation of PDGF receptors leads to the activation of p38 but not stress-activated protein kinase-1/c-Jun NH2-terminal kinase. Experiments using a specific inhibitor of p38, SB203580, show that the activation of p38 is required for PDGF-induced cell motility responses such as cell migration and actin reorganization but not required for PDGF-stimulated DNA synthesis. Analyses of tyrosine residue-mutated PDGF receptors show that Src homology 2 domain-containing proteins including Src family kinases, phosphatidylinositol 3-kinase, the GTPase-activating protein of Ras, the Src homology 2 domain-containing phosphatase SHP-2, phospholipase C-gamma, and Crk do not play a major role in mediating the PDGF-induced activation of p38. Finally, the expression of dominant-negative Ras but not dominant-negative Rac inhibited p38 activation by PDGF, suggesting that Ras is a potent mediator in the p38 activation pathway downstream of PDGF receptors. Taken together, our present study proposes the existence of a Ras-dependent pathway for the activation of p38, which is important for cell motility responses elicited by PDGF stimulation.

[Vascular remodeling and angiotensin II]

Numerous pharmacological approaches have failed to modify the high incidence of restenosis after balloon coronary angioplasty. This inability to alter the restenosis process was caused in part by our incomplete understanding of its pathology. Neointimal formation and geometric remodeling cause the restenosis after angioplasty. The development of restenosis involves vascular smooth muscle cells (VSMCs) migration and proliferation. Angiotensin II has been shown to stimulate the growth of VSMCs via an action on the angiotensin II AT1 receptor subtype. Angiotensin II AT1 receptor antagonists can block the angiotensin II-induced these actions. Angiotensin II AT1 receptor antagonists may block the restenosis after balloon coronary angioplasty.

Rubinstein-Taybi syndrome: a girl with a history of neuroblastoma and premature thelarche

A 7-year-old girl with Rubinstein-Taybi syndrome (RTS) who had a history of neuroblastoma and premature thelarche is reported. The neuroblastoma was detected at age 6 months on a nation-wide neuroblastoma screening program, surgically removed, and took a favorable clinical course with minimal therapy. She developed isolated breasts at age 6 years, had normal plasma levels of estradiol, follicular-stimulating hormone (FSH), and luteinizing hormone (LH), and showed a FSH-predominant pattern on the LH-releasing hormone stimulation test. In view of these findings, she was diagnosed to have premature thelarche. Premature thelarche may not be uncommon in girls with RTS.

The results of radiotherapy for T1 glottic cancers; influence of radiation beam energy

We analyzed the influence of various parameters on the results of radiotherapy for T1 glottic cancer by assessing the outcomes of 60 patients with this cancer who received definitive radiotherapy between 1985 and 1994. Seven patients were treated with a cobalt-60 unit, and the other 53 with a linear accelerator (26 patients at 3-MV, 10 at 6-MV, and 17 at 10-MV). Of the 17 patients treated at 10-MV, 4 also received part of their treatment with a cobalt-60 unit. The total radiation dose ranged from 56 Gy to 70 Gy (mean, 61 Gy). The total radiation dose of 51 patients (85%) was 60 Gy. The factors found to influence local control were the strength of the radiation beam energy and whether or not there was gross tumor invasion of the anterior commissure. The local control rate was 71% in the patients treated with a 10-MV linear accelerator, 56% in those treated with a 6-MV linear accelerator and, 97% in those treated with a cobalt-60 unit or a 3-MV linear accelerator (P = 0.0173). The local control rate was 43% in the patients with gross anterior commissure invasion and 88% in those without (P = 0.0075). We conclude that low energy photon beams are more suitable for the treatment of early glottic cancers, especially if the lesion grossly invades the anterior commissure.

Prostanoids and related compounds. VII. Synthesis and inhibitory activity of 1-isoindolinone derivatives possessing inhibitory activity against thromboxane A2 analog (U-46619)-induced vasoconstriction

We have synthesized a series of novel 1-isoindolinone derivatives, which inhibited the contraction of pig coronary artery induced by U-46619, a thromboxane A2 analog.

Expression of Thrombomodulin in the epithelium of the urinary bladder: a possible source of urinary thrombomodulin

Thrombomodulin (TM) is an endothelial thrombin receptor which acts as a natural anticoagulant through inactivation of the procoagulant activity of thromin. In the present study, we demonstrated that TM is expressed on the urinary bladder epithelium. The cell line BOY established from human transitional cell carcinoma of the urinary bladder also expressed the TM message (3.7kb). These cells express an 85 kDa TM protein which is identical in size to that of MEG-01, a human megakaryoblastic cell line, reported previously. We also ascertained the expression and localization of TM in the human urinary bladder by immunohistochemical staining. TM was localized in the membranes of the transitional epithelium and the cytoplasmic region of umbrella cells. The expression of TM in the transitional epithelium increased with worsening pathological status of cystitis. Based on these results, we concluded that TM is expressed in the urinary bladder. Further, soluble TM in urine may be partially derived from the urinary bladder. At present, the physiological significance of TM expression in the urinary bladder remains to be elucidated.

A new treatment for penile conservation in penile carcinoma: a preliminary study of combined laser hyperthermia, radiation and chemotherapy

OBJECTIVE

To investigate the role of laser hyperthermia in penis-conserving therapy for penile carcinoma.

PATIENTS, MATERIALS AND METHODS

Penile carcinoma KPK-1 cells were transplanted into nude mice to induce tumour; the effects of laser hyperthermia, the chemotherapeutic agent peplomycin, or their combination on the inhibition of KPK-1 tumour growth were assessed. In a clinical study, two patients with well-differentiated, stage T2 penile tumours with corporeal involvement were treated to conserve the penis using concurrent radiation, laser hyperthermia and peplomycin. They had no pathologically identified regional lymph node metastasis. Radiation was given for 5 days a week for 3 weeks at a total dose of 30 Gy. Nd:YAG laser hyperthermia was administered at 42-43 degrees C for 15 min twice a week for 3 weeks immediately after radiation. Peplomycin (10 mg per day) was administered intravenously over 24 h together with the laser hyperthermia.

RESULTS

The combined treatment with laser hyperthermia and peplomycin completely inhibited KPK-1 tumour growth, but the treatment with either laser hyperthermia or peplomycin alone had little effect. The results were also corroborated by the histopathological findings; the necrotic area in mice treated with combined therapy was much larger than that in those treated with laser hyperthermia alone. Both patients given combined laser hyperthermia, radiation and peplomycin were treated successfully, with the penis and sexual function conserved, and both survived for > 7 years with no evidence of any local or regional recurrence. There were no major complications related to the combined treatment.

CONCLUSIONS

This preliminary study showed that combined treatment with laser hyperthermia, radiation and peplomycin might be a promising therapy for conserving the penis in some patients with stage T2 penile tumours.

Fibronectin stimulates transcription of the platelet-derived growth factor beta-receptor in cultured rat aortic smooth muscle cells

Fibronectin seems to play an important role in promoting the characteristic changes of vascular smooth muscle cells in diabetes mellitus including overexpression of the platelet-derived growth factor beta-receptor. To determine the regulatory mechanism of the beta-receptor by fibronectin, we have analyzed the effect of fibronectin on the expression of the beta-receptor in cultured rat aortic smooth muscle cells using the beta-receptor promoter/luciferase expression vector system. Fibronectin was found to stimulate the expression of the beta-receptor at the transcriptional level. Both a MEK1 inhibitor PD98059 and a tyrosine kinase inhibitor herbimycin A significantly inhibited the fibronectin-stimulated receptor transcription. Herbimycin A also completely inhibited the fibronectin-stimulated increase in tyrosine phosphorylation of focal adhesion kinase. These data suggest the involvement of the integrin-mediated mitogen-activated protein kinase pathway downstream of fibronectin stimulation in the activation process of the beta-receptor promoter.

Early induction of transforming growth factor-beta via angiotensin II type 1 receptors contributes to cardiac fibrosis induced by long-term blockade of nitric oxide synthesis in rats

We previously reported that the chronic inhibition of nitric oxide (NO) synthesis increases cardiac tissue angiotensin-converting enzyme expression and causes cardiac fibrosis in rats. However, the mechanisms are not known. Transforming growth factor-beta (TGF-beta) is a key molecule that is responsible for tissue fibrosis. The present study investigated the role of TGF-beta in the pathogenesis of cardiac fibrosis. The development of cardiac fibrosis by oral administration of the NO synthesis inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) to normal rats was preceded by increases in mRNA levels of cardiac TGF-beta1 and extracellular matrix (ECM) proteins. TGF-beta immunoreactivity was increased in the areas of fibrosis. Treatment with a specific angiotensin II type 1 receptor antagonist, but not with hydralazine, completely prevented the L-NAME-induced increases in the gene expression of TGF-beta1 and ECM proteins and also prevented cardiac fibrosis. Intraperitoneal injection of neutralizing antibody against TGF-beta did not affect the L-NAME-induced increase in TGF-beta1 mRNA levels but prevented an increase in the mRNA levels of ECM protein. These results suggest that the early induction of TGF-beta1 via the angiotensin II type 1 receptor plays a major role in the development of cardiac fibrosis in this model.

Comparison of contractions produced by carbachol, thapsigargin and cyclopiazonic acid in the guinea-pig tracheal muscle

1. Thapsigargin (TPG, 3 microM) and cyclopiazonic acid (CPA, 10 microM) slowly increased muscle tone in the guinea-pig isolated tracheal muscle. A large sustained contraction was produced when 2.4 mM Ca2+ was readmitted after 10 min exposure to Ca2+-free solution following 30 min treatment with TPG or CPA. 2. The sustained contraction after Ca2+ readmission was partially inhibited by nifedipine (3 microM) and highly dependent on external Ca2+. The TPG- and CPA-induced sustained contractions were 75% and 67%, respectively, of the sustained contraction produced by carbachol (Cch, 1 microM, EC80) in the presence of nifedipine. 3. The contractions produced by Cch, TPG and CPA were all inhibited by isoprenaline (ISO) and sodium nitroprusside (SNP). In the presence of nifedipine, the IC50 of ISO was 11, 17, and 23 nM and that of SNP was 0.5, 1, 0.8 microM for Cch-, TPG-, and CPA-induced contractions, respectively. The contraction produced by 60 mM K+ was only weakly inhibited by ISO and SNP. As with ISO and SNP, the Cch-, TPG- and CPA-induced contractions were also similarly inhibited by SKF 96365 (100 microM) and cadmium (Cd2+, 100 microM). 4. It was concluded that TPG and CPA increased Ca2+ influx probably via a mechanism activated by Ca2+ depletion of the sarcoplasmic reticulum. The susceptibility of the contraction produced by TPG, CPA and Cch to inhibition by ISO and SNP and also by SKF-96365 and Cd2+ suggests that the contractions use common pathways for increasing intracellular Ca2+, and that the contractions produced by K+ involve a different mechanism.

Progression to moderate or severe mitral regurgitation after percutaneous transvenous mitral commissurotomy using stepwise inflation technique

Progression to moderate or severe mitral regurgitation (MR) was studied after Inoue balloon percutaneous transvenous mitral commissurotomy (PTMC) using the stepwise inflation technique, performed at increments of 1 mm of balloon diameter, in 49 consecutive patients with rheumatic mitral stenosis (aged from 32-73 years; 8 males, 41 females). The patients were classified on the basis of the degree of MR after PTMC, compared with that before PTMC, into either Group A, development of moderate or more severe (> or = grade 2) MR (n = 8) or Group B, no increase in MR or development of mild (grade 1) MR (n = 41). Progression to moderate or severe MR was significantly associated only with advanced age (60 +/- 8 vs 52 +/- 10 years, p < 0.05) and narrower mitral valve area (0.87 +/- 0.35 vs 1.11 +/- 0.29 cm2, p < 0.05), but other characteristics before PTMC were similar in both groups. There was no difference between the two groups in the total number and degree of balloon inflation. Immediately before the final inflation, the left atrial mean pressure and v wave pressure were decreased in smaller degrees in Group A compared with Group B (-2 +/- 2 vs -5 +/- 4 mmHg, p < 0.05; -2 +/- 2 vs -6 +/- 6 mmHg, p < 0.05, respectively). Thus, the stepwise inflations require careful monitoring of changes in the left atrial pressure and waveform to recognize the aggravation of MR, especially in older patients with severe stenosis. Patients who do not have a significant drop in left atrial mean pressure and v wave pressure during stepwise inflations of the balloon might be at risk of development of moderate or severe MR after further dilations.

Effects of excess K+ on carbachol-induced contractions in the guinea-pig tracheal muscle

1. In smooth muscles isolated from the guinea-pig trachea, the effects of dihydropyridines, nifedipine and nicardipine on contractions produced by carbachol (Cch) were studied in normal (6 mM) and excess K+ concentration (60 mM). The tonic contraction produced by 1 microM Cch was highly dependent on the external Ca2+ concentration ([Ca2+]0) and was not significantly affected by cyclopiazonic acid or thapsigargin, Ca2+ uptake inhibitor. 2. [Ca2+]0-tension curves were steeper in the presence of 1 microM Cch (the Hill coefficient: 2.5) than in the presence of 60 mM K+ (Hill coefficient: 1.6) and their ED50 of Ca2+ was 0.16 and 0.39 mM, respectively. An increase of K+ to 60 mM in the presence of 1 microM Cch shifted the curve to the left roughly in parallel (ED50: 0.12 mM, Hill coefficient: 2.3). 3. [Ca2+]0-tension curve in the presence of 1 microM Cch was shifted to the right in parallel by nifedipine (1 microM). This was markedly potentiated by 60 mM K+ (the increase in ED50 of Ca2+ being 3 times at 6 mM and 15 times at 60 mM K+). No tension was evoked by Ca2+ up to 2.5 mM in 60 mM K+ solution containing 1 microM nifedipine but no Cch. 4. In the absence of nifedipine, Cch-induced contractions were potentiated by 60 mM K+, whereas in the presence of nifedipine, Cch-induced contractions were markedly inhibited by 60 mM K+. These mechanical changes were accompanied by an increase or a decrease in intracellular Ca2+. 5. A hypothesis is presented to explain the results which suggests that the kinetics of Ca2+ influx though a single type of pathway is modulated by membrane potential and receptor activation and that the susceptibility of the pathway to dihydropyridine blockade is closely related to the Ca2+ influx kinetics with receptor activation reducing and membrane depolarization increasing the susceptibility.