Role of mitogen-activated protein kinases in endothelin ETB receptor up-regulation after organ culture of rat mesenteric artery

Organ culture of isolated arteries results in increased levels of endothelin ET(B) (ET(B)) receptor mRNA and in enhanced ET(B) receptor mediated contraction. The present study was designed to pinpoint the mitogen-activated protein kinase (MAPK) subtype involved in up-regulation of ET(B) receptors after organ culture of rat mesenteric arteries. Western blot and selective antibodies towards constitutional and phosphorylated MAPKs revealed the appearance of phosphorylated MAPK of the extracellular signal-regulated kinases (ERK) 1/2 type at 3 h of organ culture. The functional ET(B) receptor and its mRNA expression were up-regulated after 24 h of organ culture. Following incubation with the MEK 1/2 specific inhibitor SB408039 or the raf inhibitor SB386023b the up-regulation was attenuated both for ET(B) receptor responses and in ET(B) receptor mRNA expression in the vessel segments. Neither Western blot nor myograph or mRNA analysis showed involvement of the other MAPKs studied. Our results suggest that the ERK1/2 MAPKs are involved in the endothelin ET(B) receptor up-regulation following organ culture.     

Effects of topical budesonide treatment on glucocorticoid receptor mRNA down-regulation and cytokine patterns in nasal polyps

The effects of a topically applied corticosteroid, budesonide, on the expression of glucocorticoid receptor (GR) mRNA and regulation of pro-inflammatory cytokine patterns in patients with nasal polyps were evaluated. All patients were eligible for surgical polypectomy, and a majority of them had been treated with nasal steroids. Patients were given 400 microg b.i.d. (group A, n = 11), 200 microg b.i.d. (group B, n = 10), or no treatment (group C, n = 15) during two months before polypectomy. Morning serum cortisol was analyzed on the day of surgery. Surgically removed polyps were taken for analysis of GR mRNA expression by solution hybridization. Remaining tissue was cryostat-sectioned, whereafter quantification of the cytokines interleukin 1beta, interleukin 2, interleukin 4, interleukin 5, interleukin 6, interleukin 10, tumor necrosis factor alpha, and interferon gamma was made by immunohistochemistry and digitized image analysis. No significant differences among the three groups were found for any of the parameters investigated. CONCLUSION: nasal polyps do not respond with down-regulation of GR mRNA or cytokines following topical corticosteroid treatment. The proposed corticosteroid resistance may be inherent, or induced by a change of local tissue bioavailability.     

Diverging effects of 5-HT3 receptor antagonists ondansetron and granisetron on estramustine-inhibited cellular potassium transport

We used 86Rb+ (K+ analogue) to study potassium influx during the interaction of highly specific 5-HT3-receptor antagonists, ondansetron and granisetron, with the effects of the anticancer drug, estramustine phosphate, on P31 mesothelioma cells. Estramustine phosphate (80 mg/l, 142 micromol/l) for 120 min. reduced 86Rb+ influx by 18.7%. The reduction was inhibited by ondansetron (0.1 micromol/l), but augmented by granisetron (0.1 micromol/l). Serotonin (1.0 micromol/l) antagonized ondansetron inhibition and restored granisetron-augmented reduction of estramustine phosphate-induced 86Rb+ influx to the level of the drug itself. Estramustine phosphate inhibited cellular Na+, K+, 2Cl- -cotransport activity whereas Na+, K+, ATPase activity was unaffected. Ondansetron blockade of estramustine phosphate-induced reduction of 86Rb+ influx was due to increased Na+, K+, ATPase and Na+, K+, 2Cl- -cotransport whereas augmentation of estramustine phosphate-induced reduction of 86Rb+ influx by granisetron, or combination of 5-HT3 receptor antagonists with serotonin was due mainly to inhibition of cellular Na+, K+, ATPase activity Thus, ondansetron possesses a distinct ability to reverse K+ influx of tumour cells exposed to estramustine phosphate whereas granisetron does not, due to different effect on cellular Na+, K+, ATPase and Na+, K+, 2Cl- -cotransport activity. Highly 5-HT3 receptor-specific antiemetic agents may have different effects on ion transport of tumour cells during treatment with cytotoxic drugs.     

The expression of vascular endothelial growth factor correlates with mutant p53 and poor prognosis in human breast cancer

Wild-type p53 protein has been shown to inhibit angiogenesis through thrombospondin in the preclinical setting. Here, we determined the associations between the expression of the angiogenic factor vascular endothelial growth factor (VEGF) and the p53 status, including different mutation sites and types, in primary breast cancer. Cytosols from 224 primary breast cancer patients were analyzed with an enzyme immunoassay for determination of human VEGF165 protein content. p53 status was determined by cDNA-based sequencing of the entire coding region, by immunohistochemistry (IHC), and by a p53 luminometric immunoassay (LIA) method. Statistically significant associations was found between higher VEGF content and non-wild-type p53 status for all methods; sequence-based data (P = 0.0019), IHC data (P = 0.0068), and the LIA method (r = 0.427; P > 0.001). Highest VEGF values were detected in tumors with p53 insertions, deletions, and stop codon mutations (P = 0.0043). Combining p53 status and VEGF content resulted in additional prognostic information, relapse-free survival (RFS; P = 0.0377), overall survival (OS; P = 0.0319), and breast cancer corrected survival (BCCS; P = 0.0292). In multivariate analysis, the relative hazard increased when the VEGF data were added to the p53 status, with a relative hazard of 1.7 for RFS and 3.0 for BCCS, compared with 1.1 for RFS and 1.4 for BCCS among the patients with either high VEGF content or p53 mutation. Higher VEGF content was statistically significantly correlated with a worse outcome for patients with estrogen receptor-positive tumors receiving adjuvant tamoxifen: RFS (P = 0.0471), OS (P = 0.0134), BCCS (P = 0.0064), as well as in multivariate analysis with point estimates of 3.4 and 2.1 for BCCS and RFS, respectively. VEGF expression is related to p53 status in human breast cancer patients. Combining VEGF with p53 status resulted in better prognostic prediction.     

Multicenter phase II trial of temozolomide in patients with glioblastoma multiforme at first relapse

Background:Recurrent glioblastoma multiforme (GBM) is resistantto most therapeutic endeavors, with low response rates and survival rarelyexceeding six months. There are no clearly established chemotherapeuticregimens and the aim of treatment is palliation with improvement in thequality of life. Patients and methods:We report an open-label, uncontrolled,multicenter phase II trial of temozolomide in 138 patients (intent-to-treat[ITT] population) with glioblastoma multiforme at first relapse and aKarnofsky performance status (KPS) 70. One hundred twenty-eight patientswere histologically confirmed with GBM or gliosarcoma (GS) by independentcentral review. Chemotherapy-naïve patients were treated withtemozolomide 200 mg/m²/day orally for the first five days ofa 28-day cycle. Patients previously treated with nitrosourea-containingadjuvant chemotherapy received 150 mg/m²/day for the first fivedays of a 28-day cycle. In the absence of grade 3 or 4 toxicity, patients onthe 150 mg/m² dose schedule were eligible for a 200mg/m² dose on the next cycle. Results:The primary endpoint was six-month progression-freesurvival assessed with strict radiological and clinical criteria. Secondaryendpoints included radiological response and Health-related Quality of Life(HQL). Progression-free survival at six months was 18% (95%confidence interval (CI): 11%–26%) for theeligible-histology population. Median progression-free survival and medianoverall survival were 2.1 months and 5.4 months, respectively. The six-monthsurvival rate was 46%. The objective response rate (complete responseand partial response) determined by independent central review ofgadolinium-enhanced magnetic resonance imaging (MRI) scans was 8% forboth the ITT and eligible-histology populations, with an additional 43%and 45% of patients, respectively, having stable disease (SD).Objectively assessed response and maintenance of a progression-free statuswere both associated with HQL benefits (characterized by improvements overbaseline in HQL domains). Temozolomide had an acceptable safety profile, withonly 9% of therapy cycles requiring a dose reduction due tothrombocytopenia. There was no evidence of cumulative hematologictoxicity. Conclusions:Temozolomide demonstrated modest clinical efficacy,with an acceptable safety profile and measurable improvement in quality oflife in patients with recurrent GBM. The use of this drug should be exploredfurther in an adjuvant setting and in combination with other agents.     

Hypothermic modulation of doxorubicin, cisplatin and radiation cytotoxicity in vitro

BACKGROUND: The influence of hypothermia on doxorubicin, cisplatin and radiation cytotoxicity was investigated in vitro. MATERIALS AND METHODS: A human glioma cell line (251MG) in early exponential growth was exposed to doxorubicin or cisplatin at various concentrations for 4 hours, or X-irradiation at 28 degrees C or 37 degrees C. The cells continued growing in multi-well plates at 37 degrees C and were counted every third day until the end of the logarithmic phase, on day 13. RESULTS: Exposure to doxorubicin 0.05-0.5 microg/ml or cisplatin 1-10 microg/ml caused a dose-dependent inhibition of cell growth with a significantly reduced toxicity when exposed at 28 degrees C as compared to 37 degrees C. Irradiation with 4 Gy also resulted in less toxicity during hypothermia. Chlorpromazine 0.01-10 microg/ml, used to induce hypothermia in vivo (1), neither influenced, cellular growth itself nor interacted with doxorubicin, cisplatin or irradiation. CONCLUSION: Moderate hypothermia (28 degrees C) appears to protect against the cellular insult of doxorubicin, cisplatin and ionising irradiation and their consequences.     

Suicide attempts and personality disorder

OBJECTIVE: The purpose of the present study was to compare clinical characteristics of suicide attempters with or without personality disorders. METHOD: A systematic sample (n = 114) of patients from consecutive cases of attempted suicide referred to general hospitals in Helsinki was interviewed and diagnosed according to DSM-III-R. Forty-six subjects with DSM-III-R personality disorders were identified and divided into clusters A (n = 4), B (n = 34) and C (n = 8). These subjects were compared with 65 suicide attempters without personality disorders in terms of clinical characteristics and treatment received. RESULTS: Suicide attempters with personality disorders more often had a history of previous suicide attempts and lifetime psychiatric treatment than comparison subjects. However, suicide attempts did not differ in terms of suicide intent, hopelessness, lethality or impulsiveness between subjects with or without personality disorders. CONCLUSION: Although suicidal behaviour is a more persistent feature among those with personality disorders, their clinical characteristics at the time of a suicide attempt may not differ from those without personality disorders.     

In vivo intrinsic efficacy of the 5-HT1A receptor antagonists NAD-299, WAY-100,635 and (S)-(-)-UH-301 at rat brain monoamine receptors.

The receptor-mediated control of brain monoamine synthesis was used to examine the in vivo intrinsic efficacy of the 5-HT1A receptor antagonists NAD-299, S(-)-UH-301 and WAY-100,635. The rate of monoamine synthesis was estimated by measuring the accumulation of DOPA and 5-HTP in the ventral neostriatum and the ventral hippocampus in rats pretreated with an inhibitor of cerebral aromatic L-amino acid decarboxylase. S(-)-UH-301 (2.0-32.0 micromol kg(-1)), but not WAY-100,635 (0.08-1.2 micromol kg(-1)), produced a decreased 5-HTP accumulation in the neostriatum and in the hippocampus. The administration of NAD-299 (0.75-12.0 micromol kg(-1)) resulted in a slight increase in neostriatal, but not hippocampal, 5-HTP accumulation. Neostriatal DOPA accumulation was decreased by S(-)-UH-301, whereas treatment with WAY- 100,635 resulted in an increase. NAD-299 did not affect neostriatal DOPA levels. There were no effects by any of these agents on DOPA levels in the ventral hippocampus. It is concluded that S(-)-UH-301, but not WAY-100,635 or NAD-299, displays intrinsic efficacy at brain 5-HT1A and DA D2/3 receptors, whereas WAY-100,635 behaves as a DA D2/3 receptor antagonist. By this comparison, NAD-299 appears to be the most selective and specific 5-HT1A receptor antagonist.     

Effects of Amifostine on Cisplatin Induced DNA Adduct Formation and Toxicity in Malignant Glioma and Normal Tissues in Rat

The chemoprotective effect of amifostine (WR2721) was studied in a BDIX rat model with intracerebral BT4C glioma implants. Twenty-one rats were given cisplatin 5mg/kg i.p., 21 were given amifostine 200mg/kg i.p.+cisplatin 5mg/kg i.p. Ten rats served as untreated controls. An immunohistochemical method for analysis of cisplatin–DNA adducts was used to elucidate the adduct formation in tumor, normal brain and kidney. Tumor volume and serum creatinine level were analysed 10 days after treatment. In animals pretreated with amifostine there was a delayed adduct formation rate in the normal brain, and in the kidney cortex the number of tubular cells with extremely high adduct level was reduced. No difference in adduct formation was seen in tumors. Tumor volume was significantly larger following amifostine+cisplatin (66% of controls) compared to cisplatin alone (38% of controls). Weight loss was, however, severe in rats given cisplatin alone. In the tumor growth study only 3 out of 11 rats treated with cisplatin 5mg/kg alone survived until time of sacrifice at 10 days, whereas all those pretreated with amifostine survived. Mean serum creatinine was 48µmol/l (controls), 146µmol/l (cisplatin) and 59µmol/l (amifostine+cisplatin). A marked reduction of histopathological renal changes was found when amifostine was added. Amifostine thus significantly reduced general and renal toxicity of cisplatin. The tumor growth retardation was stronger when cisplatin was given alone but this is probably related to general toxicity and malnutrition indirectly supported by the fact that amifostine did not significantly reduce cisplatin–DNA adduct formation in tumors. The results of the present study suggest that amifostine may have a role in increasing the therapeutic ratio of cisplatin, also in the treatment of malignant glioma.     

Factor XIII (fibrin stabilising factor) in Henoch-Sch?nlein's purpura.

In 13 out of 17 consecutive children with Henoch-Sch?nlein's purpura the factor XIII determined with the dansyl cadaverine method was found to be decreased during the acute phase. The decrease is assumed to be due to a specific degradation by proteolytic enzymes liberated from inflammatory cells, with defective local haemostasis as a result. This assumption is strengthened by the observation that treatment with factor XIII combined with an antifibrinolytic drug controlled life-threatening gastro-intestinal bleeding in one of the patients. It would therefore appear that such treatment might offer a new possibility of controlling severe haemorrhages in Henoch-Sch?nlein's purpura.