[Combination chemotherapy with vinorelbine and other cytotoxic agents for advanced breast cancer patients--a protocol of vinorelbine plus AC regimens used by the Japan Vinorelbin Study Group]

A new generation type of vinca alkaloid, vinorelbine (VNR), is a promising agent for the treatment of breast cancer patients. As a first line treatment for metastatic breast cancer, combination chemotherapy including anthracyclines plus VNR has demonstrated a high response rate and tolerability. In addition, other VNR containing regimens, such as 5-fluorouracil plus VNR, produced a 64% response rate. This evidence suggests VNR-containing combination chemotherapy may be a promising first-line treatment for breast cancer patients. In Japan, VNR is not registered, but a late phase II study has been completed. An approximately 30% response rate was obtained with its use as a monotherapy. In addition, a phase I/II study of combination VNR plus AC (adriamycin + cyclophosphamide) has been conducted. At the present time, the results are being analyzed.

Effect of ER-27856, a novel squalene synthase inhibitor, on plasma cholesterol in rhesus monkeys: comparison with 3-hydroxy-3-methylglutaryl-coa reductase inhibitors

Squalene synthase (SQS; EC 2.5.1.21) plays an important role in the cholesterol biosynthetic pathway. We discovered ER-28448, 5-(N-[2-butenyl-3-(2-methoxyphenyl)]-N-methylamino)-1, 1-penthylidenebis(phosphonic acid) trisodium salt, as a potent and selective inhibitor of SQS. ER-28448 inhibited SQS in rat liver microsome with an IC(50) value of 3.6 nm. We also prepared ER-27856, the tripivaloyloxymethyl ester prodrug of ER-28448. Although less active than ER-28448 in a liver microsome assay, ER-27856 more potently inhibited cholesterol biosynthesis in rat hepatocytes; and ER-27856 orally inhibited de novo cholesterol biosynthesis in Sprague-Dawley rats, with an ED(50) value of 1.6 mg/kg. In HepG2 cells, ER-27856 upregulated low density lipoprotein receptor activity to 2.1 times that of control. A time-course study indicated that the inhibitory effect of ER-27856 on cholesterol biosynthesis in rats continued for up to 8 h. In a study of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (HMGRIs), atorvastatin actively suppressed cholesterol biosynthesis for 8 h, whereas the effect of pravastatin and simvastatin diminished at 4 and 8 h, respectively. In rhesus monkeys, 4 days of oral administration of ER-27856 lowered plasma total cholesterol (TCHO) more potently than did these HMGRIs. Whereas atorvastatin significantly elevated plasma alanine aminotransferase, a marker of hepatotoxicity, to 3.7 times at 100 mg/kg, ER-27856 increased the level only 1.4 times at 10 mg/kg, at which doses the hypocholesterolemic effect was equivalent. During 28 days of administration, ER-27856 reduced TCHO and non-high density lipoprotein (non-HDL) cholesterol by 72 and 95%, respectively. These results demonstrate that ER-27856 had more potent hypocholesterolemic activity and less hepatotoxic effect than HMGRIs. ER-27856 may contribute to the treatment of hypercholesterolemic patients.

Mechanism of prevention by capsaicin of ethanol-induced gastric mucosal injury--a study in the rat using intravital microscopy

BACKGROUND

Capsaicin acts specifically on primary afferent neurones to release neuropeptides, including calcitonin gene-related peptide (CGRP), and prevents ethanol-induced mucosal injury.

AIM

To investigate the microvascular changes in the gastric mucosa in response to ethanol using intravital microscopy to elucidate the mechanism of capsaicin-induced gastroprotection.

METHODS

The posterior gastric wall in the rat was secured in an observation chamber and perfused with Tyrode's solution. The microcirculation was observed through a window made by removing a limited area of smooth muscle.

RESULTS

Ethanol (50%) applied to the mucosa constricted the collecting venules and venules but dilated arterioles. The constriction of the collecting venules resulted in mucosal congestion, which caused mucosal injury. Application of capsaicin to the mucosa dilated the arterioles but not the collecting venules or venules. Arteriolar dilation was inhibited by a CGRP antagonist, CGRP-(8-37). Prior application of capsaicin prevented ethanol-induced constriction of the collecting venules, and the action of capsaicin was inhibited by prior application of CGRP-(8-37).

CONCLUSIONS

The results suggest that the inhibition of ethanol-induced gastric injury by capsaicin is attributable to the suppression of collecting venule constriction, via CGRP release.

Antitumorigenic effects of several food proteins in a rat model with colon cancer and their reverse correlation with plasma bile acid concentration

In order to obtain information on the preventive effects of various food proteins against colonic cancer, six groups of azoxymethane-initiated mature Fischer rats (n = 10) were fed respective diets different in protein sources such as bovine milk casein (casein), high-molecular-weight fraction from protolytic digest of soy protein isolate (soybean HMF), hen's yolk defatted protein (yolk protein), wheat gluten and codfish meat, which had been supplemented with sodium deoxycholate (hereinafter, DCA) as a cancer promoter except for an additional DCA-unfed casein group. All of the living rats at checkpoints during the feeding period were examined by the use of a bronchus fiberscope for colonic tumor incidence at 6 wk intervals between the 10th and 34th wk, from which both blood and feces samples were taken at times of endoscopy. Tumorigenesis in the colon was perceived by endoscopy at wk 22 in the group fed DCA casein only and at wk 28 in the other groups except the DCA-unfed casein group. At wk 34, both soybean HMF and yolk protein groups ranked inferior to the DCA-unfed group in tumor incidence. When plasma steroid or lipid concentration was plotted against tumor incidence at wk 28 or 34, positive correlations were found between plasma bile acid concentration and tumor incidence at both weeks. With the exception of the DCA-unfed casein group, plasma bile acid concentration was reversely correlated to fecal bile acid excretion. Taken altogether, these results suggest that bile acids at higher concentrations in the plasma may serve as risk factors of colon tumor incidence.

Precision measurement of cosmic-Ray antiproton spectrum

The energy spectrum of cosmic-ray antiprotons ( &pmacr;'s) has been measured in the range 0.18-3.56 GeV, based on 458 &pmacr;'s collected by BESS in a recent solar-minimum period. We have detected for the first time a characteristic peak at 2 GeV of &pmacr;'s originating from cosmic-ray interactions with the interstellar gas. The peak spectrum is reproduced by theoretical calculations, implying that the propagation models are basically correct and that different cosmic-ray species undergo a universal propagation. Future BESS data with still higher statistics will allow us to study the solar modulation and the propagation in detail and to search for primary &pmacr; components.

Preventive effect of soybean resistant proteins against experimental tumorigenesis in rat colon

The insoluble 'high-molecular-weight' fraction (HMF) centrifugally separable after digestion of soy protein isolate with a microbial protease of the exo-type, of which about a quarter is regarded as an indigestible 'resistant protein,' was examined for its preventive effect against colonic tumorigenesis in a model system with male F-344 rats. The rats were intraperitoneally injected with azoxymethane (15 mg/kg BW) once a week for 3 wk and were fed a 20.6% HMF diet (+0.4% DL-Met) or 14.7% casein diet (+0.3% DL-Met) supplemented with 0.2% sodium deoxycholate (DCA) or without supplementation. Twelve wk later, 5 rats of each group were inspected for formation of tumors but no tumors were visible to the naked eye. The DCA-fed casein group was conspicuous for a low count of aberrant crypt foci. At 39 wk, 6 rats of the DCA-fed casein group (n = 10) and 3 rats of the DCA-fed HMF group (n = 9) had a total of 18 tumors with a major axis of 4.0 +/- 0.4 mm and 3 tumors with an axis of 2.0 +/- 0.1 mm, respectively, in contrast to only a single tumor for the DCA-unfed casein group (nil for the DCA-unfed HMF group). The difference in tumor number and size was considered significant between these DCA-fed casein and HMF groups; that is to say, HMF feeding retarded tumor development despite the frequent occurrence of pre-neoplastic lesions. In addition, fecal bile acid excretion was much more elevated by HMF feeding than by casein feeding. It can be assumed from these observations that the antitumorigenicity of HMF is due to the inhibitory effect of soybean resistant proteins on reabsorption as well as the mucosal contact of bile acids in the intestine.

[Cancer chemotherapy based on evidence--metastatic breast cancer]

Breast cancer is relatively sensitive to chemotherapy. However, although response rate to chemotherapy is reported to be from 50 to 70% in metastatic breast cancer, it is incurable. Current standard chemotherapeutic regimens do not provide a large survival benefit according to the evidence obtained from clinical studies. Before developing a treatment program, we should therefore realize that the aims of chemotherapy for metastatic breast cancer are improvement of quality of life through relief of symptoms, and prolonging survival.

[Two cases of silicosis exhibiting MPO-ANCA associated disorder]

We reported two cases of silicosis exhibiting MPO-ANCA associated disorder. Case 1 was a 69 year-old man with silicosis and chronic interstitial pneumonia. He was admitted because of fever, dry cough, left chest pain, dyspnea and body weight loss. He was diagnosed as acute exacerbation of interstitial pneumonia, pericarditis and gastrointestinal bleeding. Case 2 was a 67 year-old man with silicosis. He repeated attack of fever, hoarseness, dysphagia and headache. The cell counts of cerebrospinal fluid increased and the thickness of cerebellar tent and left dura mater was observed in the brain MRI. Therefore, he was diagnosed as pachymeningitis and neuropathy of cranial nerves. Both cases were complicated by silicosis and the laboratory findings showed high serum levels of P-ANCA, ANA and rheumatoid factor and inflammatory responses, indicating they were suspected vasculitis. The two cases were treated by steroid and immunosuppressive therapy and had good clinical response. Silicosis may affect multiple organ involvement associated with P-ANCA.

[Reflections on the teaching to undergraduate nurses about group dynamics]

The present article aims at reflecting on the experience of the authors about the nursing undergraduate teaching on group dynamics, that began in 1992. Authors focus nursing and the works with groups; the structure, content and development of this specific course.

Phosphodiesterase 4 conformers: preparation of recombinant enzymes and assay for inhibitors

Cyclic nucleotides are key regulators of many cellular processes. Their immediate action is terminated through the activity of phosphodiesterases, a diverse family of enzymes. This diversity has given rise to drug discovery opportunities, and assay technology is therefore of key importance. Inhibitors of the cyclic-AMP-specific phosphodiesterases (the PDE4 family) are drug candidates for a variety of inflammatory disorders. However, PDE4 inhibitors, besides their immunomodulatory effects, also cause side effects including nausea and emesis. Recently, it has been suggested that PDE4 exists in two different conformations with respect to inhibition by the prototypical compound rolipram. Inhibition of the low-affinity conformer is thought to give rise to anti-inflammatory effects, and inhibition of the high-affinity conformer to side effects. Therefore, a selective inhibitor of the low-affinity conformer may have clinical utility. Methods are described to prepare recombinant forms of PDE4B that allow screening for compounds that could preferentially inhibit the low-affinity conformer. Furthermore, conditions for an efficient, scintillation proximity, microtiter plate-based assay are described, providing a considerable advance over previous assays in terms of throughput and automatability.

Reaction of Hypercoordinate Dichlorosilanes Bearing 8-(Dimethylamino)-1-naphthyl Group(s) with Magnesium: Formation of the 1,2-Disilaacenaphthene Skeleton

Migration of NMe(2) from C(naphthyl) to Si and Si-Si and Si-C bond formation to give a 1,2-disilaacenaphthene skeleton occurred in the reaction of hypercoordinate dichlorosilanes bearing the 8-(dimethylamino)-1-naphthyl group with two equivalents of magnesium [e.g., Eq. (a)]. The intermediate was isolated as the 1-isopropoxy derivative after quenching the reaction mixture with isopropyl alcohol.

An extremely large solitary primary paraganglioma of the lung: report of a case

We present herein the case of a 38-year-old woman found to have an extremely large solitary primary paraganglioma of the lung. The patient presented with chest pain on exertion and a mass was discovered in the left lower lobe of the lung by chest X-rays and computed tomography (CT). As no other neoplasms were detected elsewhere, a left lower lobectomy was performed. The patient has remained well without any evidence of recurrence for 5 years since her operation. The tumor, measuring 13 x 12 x 7 cm, was composed of ovoid cells (Zellballen), which were positive for Fontana-Masson and Grimelius stains, and sustentacular cells. Immunohistochemically, the ovoid cells were positive for neuron-specific enolase, S-100, CAM5.2, Leu7, and chromogranin A, and negative for carcinoembryonic antigen and epithelial membrane antigen. The sustentacular cells were positive for S-100 protein and CAM5.2, and negative for glial fibrillary acid protein. Therefore, the tumor was diagnosed as a paraganglioma. The tumor from our patient is the largest of the 17 solitary primary pulmonary paragangliomas reported thus far in the English-language literature.

Localization of Estrone Sulfatase in Human Breast Carcinomas

We generated anti-human E1-STS monoclonal antibodies to localize estrone sulfatase (E1-STS) in human breast carcinomas. In particular, we examined the MCF-7 clone E3, ZR-75-1, MDA-MB 231, and MDA-MB-468 breast cancer cell lines and 25 breast carcinomas by either immunohistochemistry or Western blotting analysis. Simultaneously, we analyzed histological data, estrogen receptor (ER) status, progesterone receptor (PgR) status and epidermal growth factor receptor (EGFR) in breast tissue. All were surgical specimens from female patients. Nine of 25 carcinomas were obtained from premenopausal women, and 16 carcinomas were obtained frompostmenopausal women. All cell lines demonstrated positive staining for E1-STS.Interestingly, fine granulated staining of E1-STS on the cell membrane was observed. In addition, Western blotting analysis detected a 65 kD protein with an E1-STS specific band in all breast cancer cell lines regardless of the presence orabsence of E2. Twenty-two of 25 (88.0%) carcinomas showed positive staining forE1-STS, whereas negative staining was observed in the interstitial tissue surrounding tumors. In the premenopausal patients, 8 of 10 carcinomas (80.0%) showed positive staining for E1-STS, whereas 14 of 15 carcinomas (93.3%) revealed positive staining in the postmenopausal patients. The frequency of E1-STS expression was relatively higher in postmenopausal patients than in premenopausal patients but not statistically significant. The intensity of immunostaining for E1-STS depended upon the size of the tumor (NS). There was no correlation between E1-STS expression and other parameters. This evidence suggests E1-STS expression may beinvolved in the development of breast cancer. Further studies are necessary to clarify the relationship between E1-STS expression and prognostic factors. Immunoreactive E1-STS may be localized in cancer cells but not in surrounding tissuesin breast cancer.

Elimination of Na+-dependent bile acid transporter from small intestine by ileum resection increases [correction of increase] colonic tumorigenesis in the rat fed deoxycholic acid

Ileal Na+-dependent bile acid transporter (ISBT) constituting a gateway to enterohepatic circulation of bile acids occurs exclusively at the distal site of the small intestine. In the present study, we examined colonic tumorigenesis promoted by deoxycholic acid in relation to the expression of the ISBT. For this purpose, the small intestine of a Fischer-344 rat was resected a length of 20 cm above the ileo-cecal valve (ileal resection) or below the duodenum (jejunal resection). Then, rats were treated with an intraperitoneal injection of azoxymethane (15 mg/kg body wt.) once a week for 3 weeks and fed a 20% casein diet supplemented with 0.2% deoxycholate for 39 weeks. Northern blot analysis demonstrated that the ISBT mRNA was hardly detectable in ileum-resected rats. The excretion of fecal bile acids was 1.5-fold higher in the ileum-resected group than in the jejunum-resected group (P < 0.05). On the contrary, the serum bile acids concentration of ileal-resected rats was about one-half of that of jejunum-resected animals (P < 0.05). The tumor incidence and the total tumor number were significantly higher in the ileum-resected group than in the jejunum-resected one (P < 0.05). Interestingly, no tumor was found at the proximal colon in the jejunum-resected group while tumors developed frequently at the proximal site as well as mid and distal colon in the ileum-resected group. These observations demonstrate that malabsorption of bile acids owing to the lack of ISBT enhanced colon tumorigenesis.

Inhibitory effect of telomere-mimic phosphorothioate oligodeoxy nucleotides (S-ODNS) on human tumor cell lines

To clarify the inhibitory effect of telomere-mimic oligonucleotides on human cancer cell lines, we synthesized 18-mers (18T; n = 3), 24-mers (24T; n = 4) and 30-mers (30T; n = 5) of telomere-mimic phosphorothioate oligodeoxy nucleotides [5'-d(TTA GGG)n-3'] and examined their effects on the proliferation of human tumor cells by XTT assay. After 7 days of continuous exposure to 24T and 30T at concentrations ranging from 0.1 to 10 microM, concentration-dependent cell growth inhibition was observed in MCF-7 clone E3, ZR-75-1, MDA-MB 231, Colo 201 and WiDr. All of these cell lines highly expressed telomerase using the telomeric repeat amplification protocol. None of these tumor cell lines were affected by 18T. In MCF-7, ZR-75-1 and Colo 201 cell lines, a more than 50% growth inhibition was obtained by 3 microM of 24T and 30T whereas, in MDA-MB 231 and WiDr cell lines, cell growth inhibition was less than 50%. 30T was more effective than 24T. Estrogen-dependent growth of both MCF-7 and ZR-75-1 was inhibited by 3 microM of 24T and 30T, however, in the absence of estrogen, no growth inhibition was seen. The MCF-10A cell line, which was developed from normal human breast tissue and expressed telomerase only weakly, was inhibited by 10 microM of 18T. In conclusion, these observations indicate that S-ODNs inhibit tumor growth in cell lines expressing telomerase in a concentration-dependent manner and that cell growth inhibition is dependent on the length of S-ODNs. In addition, the short-length S-ODNs may inhibit growth of cells weakly expressing telomerase, but not of cells with high telomerase expression.

Dilatation and constriction of rat gastric mucosal microvessels through prostaglandin EP2 and EP3 receptors

BACKGROUND

Prostaglandin (PG)E2 has both a vasodilating action and a protective function in the gastric mucosa. There are four subtypes of PGE2-sensitive, or EP, receptors.

AIM

To identify the subtype of EP receptors in the microvessels of the rat gastric mucosa using EP2 and EP3 receptor agonists.

METHODS

The posterior wall of the anaesthetized rat stomach was secured in a chamber and superfused with Tyrode's solution, and the gastric microcirculation of the mucosal base was observed through a window with transillumination. PGE2 and its derivatives (20 microL) were applied topically in the window.

RESULTS

PGE2 (0.001-10 micromol/L), misoprostol (EP2/EP3 receptor agonist; 0.01-100 micromol/L) and butaprost (EP2 receptor agonist; 1-1000 micromol/L) dilated the arterioles dose-dependently, but M&B 28 767 (EP3 receptor agonist; 0.001-10 micromol/L) did not alter their diameters. M&B 28 767 constricted the venules and collecting venules dose-dependently whereas butaprost dilated them. PGE2 and misoprostol had bell-shaped dose-response curves: constriction by low doses of PGE2 and misoprostol (0.001-0.1 micromol/L and 0.01-1 micromol/L) and dilation by high doses of PGE2 and misoprostol (0.1-100 micromol/L and 1-100 micromol/L).

CONCLUSIONS

These results suggest that PGE2 dilated both arterioles and venules in the rat gastric mucosa through the EP2 receptors and constricted the venules through the EP3 receptors.

Two new triterpenoid saponins from Platycodon grandiflorum

Two new triterpenoid saponins, platycoside D [3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-(1-->6)-beta-D- glucopyranosyl-2 beta, 3 beta, 16 alpha, 23-tetrahydroxyolean-12-ene-28-oic acid 28-O-beta-D- apiofuranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnop yranosyl- (1-->2)-alpha-L-arabinopyranoside] and platycoside E [3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl- (1-->6)-beta-D-glucopyranosyl-2 beta,3 beta,16 alpha,23,24-pentahydroxyolean-12-ene-28-oic acid 28-O-beta-D-apiofuranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alp ha-L- rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside] were isolated from the roots of Platycodon grandiflorum. Structural determination is based on spectral and chemical evidence.

Functional interleukin-5 activity in peripheral blood mononuclear cells from adolescents with mite antigen asthma in remission

BACKGROUND

Asthma improves in most children during adolescence such that a small minority of patients exhibit clinically significant symptoms by the age of 20 years.

OBJECTIVE AND METHODS

To investigate late allergic reactions, including eosinophil inflammation, associated with outgrowing mite antigen-induced bronchial asthma during adolescence, the relationship between clinical status and functional activity of interleukin (IL)-5 produced by Dermatophagoides farinae (Df)-stimulated peripheral mononuclear cells (PBMCs) in culture was assessed in mouse IL-3-dependent cells transfected with the human IL-5 receptor gene.

RESULTS

Activity of IL-5 spontaneously produced by PBMCs from either patients with mite-sensitive bronchial asthma or nonatopic control subjects was low. The activity of IL-5 produced by PBMCs stimulated with concanavalin A was significantly higher. Upon challenge with specific allergens, such as Df antigen, but not with irrelevant antigens, including ovalbumin, the in vitro activity was increased in patients with active disease and decreased in patients in remission.

CONCLUSION

Results suggest that the antigen-specific up-regulation of functional IL-5 activity in late allergic reactions is reduced in patients in remission and likely to result in an improvement in clinical status. The Df antigen may suppress Df-induced responses in patients with asthma in remission.

A comparative study on commercial, botanical gardens and wild samples of the roots of Platycodon grandiflorum by HPLC analysis

Thirteen commercial samples of Platycodi radix of Platycodon grandiflorum, were collected from China (5 kinds), Korea (5 kinds), and Japan (3 kinds) along with 8 kinds of botanically cultivated Platycodi radix, 3 kinds of wild Platycodi radix collected from different places in Japan. HPLC analysis showed that the commercial botanical and wild samples of P. radix all contained platycodins and a total of twelve peaks were identified by co-HPLC anlaysis with authentic samples isolated earlier from this laboratory. The peak purity and identify were checked with a PDA. The contents of the major saponins, platycodins A, C, D were determined and the peak-area ratios of platycodins A, C, D were shown to be correlated with their sources of origin. The commercial samples from China and Korea each gave a distinct HPLC pattern with peak-area ratio of platycodins A, C, D at 1:2:3 and 2:4:1, respectively. HPLC analysis showed that those on the Japanese market were either imported from China or Korea based upon their HPLC patterns while the Japanese botanical garden or wild type samples gave a higher total saponin content with the peak-area ratio of platycodins A, C, D at 1:2:1.

Characterization, cDNA cloning, and functional expression of mouse ileal sodium-dependent bile acid transporter

Mouse ileal sodium dependent bile acid transporter (ISBT) was characterized using isolated enterocytes. Only enterocytes from the most distal portion showed Na+-dependent [3H]taurocholate uptake. Northern blot analysis using a probe against mouse ISBT revealed the expression of mouse ISBT mRNA to be restricted to the distal ileum. The Km and Vmax for Na+-dependent [3H]taurocholate transport into isolated ileocytes were calculated as 27 microM and 360 pmol/mg protein/min, respectively. Uptake of [3H]taurocholate was inhibited by N-ethylmaleimide. We have cloned ISBT cDNA from mouse ileum. The cDNA included the entire open reading frame coding 348 amino acid protein with seven hydrophobic segments and two N-glycosylation sites. COS-7 cells transfected with the expression vector containing this cDNA expressed Na+-dependent [3H]taurocholate uptake activity with a Km of 34 microM.

[Mechanism and possible biochemical modulation of capecitabine (Xeloda), a newly generated oral fluoropyrimidine]

A new 5-FU analog, Capecitabine (Xeloda; N-[1-(5-deoxy-b-D-ribofuranosyl)-5-fluoro-1, 2-dihydro-2-oxo-4-pyrimidyl]-n-penyl carbamate), was generated to decrease the incidence of GI toxicity and to increase the efficacy. Capecitabine is designed as a prodrug of 5'-deoxy-5-fluorouridine (5'-DFUR), which is clinically used for gastric, breast and colorectal cancer patients undergoing single or combination chemotherapy in Japan. Capecitabine was converted to 5'-DFUR by either human carboxyestelase or cytidine deaminase, which were mainly localized in human liver. 5'-DFUR was converted to the active form of 5-FU by thymidine phosphorylase (dThdPase) in human tumors. The expression of dThdPase was higher in malignant tumors than in noninvolved normal tissues. In this regard, a high concentration of either 5'-DFUR or 5-FU in malignant tumors may be obtained by oral administration of Capecitabine. In addition, in vivo study showed synergistic or additive effects of Capecitabine combined with anti-cancer agents (Taxanes, Mitomycin C or Cyclophosphamide), cytokines, growth factors and hormonal agents. Capecitabine may be biochemically modulated by those agents in vivo. In the results of an early phase II study on breast cancer patients in Japan, a high efficacy rate and low toxicity were observed. Also, Capecitabine was already registered as 2nd- or 3rd-line treatments for breast cancer patients by the Food & Drug Administration of the USA. Capecitabine is one of the most promising orally administered 5-FU analogs.

Inositol-1,4,5-trisphosphate increases contractions but not L-type calcium current in guinea pig ventricular myocytes

OBJECTIVE

We studied the effects of intracellularly applied inositol-1,4,5-trisphosphate (InsP3) to test the hypothesis that InsP3 is a messenger for stimulation of L-type calcium current (ICa(L)) and contractions by muscarinic agonists.

METHODS

Voltage clamp pulses elicited ICa(L) that evoked contractions recorded with an edge detector in single guinea pig ventricular myocytes superfused with Tyrode's solution (36 degrees C). InsP3 or cyclic AMP (cAMP) was dialyzed into the cell at selected times via the patch electrode.

RESULTS

InsP3 (1-10 microM) transiently increased isotonic contractions when applied for 4-5 min; higher concentrations (50-300 microM) caused a sustained decrease in contractions. InsP3 had no effect on ICa(L) at any concentration tested. Caffeine (10 mM)-induced contractures were increased and decreased, respectively, at 3 and 100 microM InsP3. Pentosan polysulfate (50 micrograms/ml), an InsP3 receptor antagonist, opposed the increased contractions by InsP3. Intrapipette cyclic AMP (10-300 microM) caused sustained increases of ICa(L) and contractions. Cyclic AMP, but not InsP3, also increased ICa(L) when intrapipette Cs+ suppressed K+ currents.

CONCLUSIONS

Increased myocyte shortening at low InsP3 concentrations accords with receptor-initiated sarcoplasmic reticulum Ca2+ release. The transient stimulation of contractions at low concentrations and the sustained reduction of contractions at high concentrations are not consistent with a role for InsP in the persistent increase of contractions by muscarinic agonist in ventricular muscle and myocytes. The failure of InsP3 to change ICa(L) when contractions were increased or decreased militates against the L-type calcium channel being an effector of InsP3.

[Two cases of descending necrotizing mediastinitis]

Descending necrotizing mediastinitis (DNM) is relatively rare inflammatory lesion with high mortality unless an appropriate surgical treatment is undertaken. Recently we successfully treated two surgical cases of DNM. In both cases, the disease started with pharyngeal abscess, and the mediastinal swelling followed. The surgery consisted with neck drainage and the mediastinal drainage through thoracotomy at the same time. A continuous mediastinal irrigation was performed postoperatively, and both patients recovered well. Immediate drainage of the primary lesion and the mediastinum is important once the diagnosis of DNM is established.