Correlation of Smac/DIABLO protein expression with the clinico-pathological features of breast cancer patients.

Smac/DIABLO protein promotes caspase-dependent apoptosis by inhibition of inhibitor of apoptosis protein (IAP) family members. The role of Smac/DIABLO in breast cancer has not been yet established. Therefore, the aim of the study was to assess the expression of this protein in tumor cells from breast cancer patients. The expression of Smac/DIABLO was analyzed in 62 breast cancer patients by flow cytometry. The obtained results were compared with expression of this protein in benign breast tumor tissue, which served as the control (11 patients with fibroadenoma). Expression of caspase-3 proteins in breast cancer was also evaluated. Smac/DIABLO expression in breast cancer was correlated with clinical and pathological data. Although the expression of Smac/DIABLO protein was found in all examined samples of both the breast cancer and fibroadenoma patients, the median expression of Smac/Diablo in breast cancer was significantly lower than in the control (39.1% vs. 48.1%; p=0.0047). Smac/DIABLO expression correlated with expression of caspase-3 (p=0.000008). In pT1 breast cancer patients, expression of Smac/DIABLO protein was higher than in those with pT2-3 (p=0.02). Diffuse cancer infiltration significantly correlated with lower expression of Smac/DIABLO protein (p=0.02). Moreover, there was a loose correlation between low expression of Smac/DIABLO protein and cancer embolus in minor blood and lymphatic vessels (p=0.08). Our results indicate that expression of Smac/DIABLO inversely correlates with the tumor stage, which may suggest that this protein may play an important role in the breast cancer development.

Astonishingly rapid growth of malignant cystosarcoma phyllodes tumor in a pregnant woman--a case report.

There are very few reports concerning the presence of malignant cystosarcoma phyllodes (CSP) in breasts of pregnant women. In the hereby described case, a 28-year-old woman presented in our department with huge (18 x 11 x 8 cm) tumor of left breast, 2 weeks after labor. The patient discovered a tumor in 34th week of pregnancy, 6 weeks before labor. Histopatholgic examination of excised tumor revealed the presence of malignant CSP tumor. Simple mastectomy was proposed to patient as a best treatment modality. However, the patient refused. She underwent excision of tumor bed (2-cm tumor-free margin was achieved). Despite insufficient treatment, she remains free of disease 20 months after the wide excision of breast malignancy. It is not known how pregnancy influences prognosis of patients with malignant CSP. Lack of such information prompted us to describe the clinical course of our patient.

Does fecal diversion offer any chance for spontaneous closure of the radiation-induced rectovaginal fistula?

Analysis of the clinical course of patients with postirradiation rectovaginal fistula after fecal diversion. The studied group included 17 women with postirradiation rectovaginal fistula who underwent fecal diversion as a sole mode of treatment, between January 1987 and December 2002, in our department. All patients were subjected to radiotherapy due to cancer of the uterine cervix, administered 5-107 months before the fistula appearance (mean, 22.9 months). In 3 of 17 patients (18%), spontaneous closure of fistula was observed after 5, 6, and 9 months, respectively, from fecal diversion. Closure was confirmed by endoscopy. Length of follow-up after fecal diversion ranged from 0.5 to 122 months. The actuarial probability of spontaneous closure of postradiotherapy rectovaginal fistula was 0.24 at 9 months of follow-up and then remained stable thereafter. In conclusion, colostomy alone gives hardly a chance for closure of the postradiotherapy rectovaginal fistula. Additional surgical measures are necessary.

A meta-analysis of nausea and vomiting following maintenance of anaesthesia with propofol or inhalational agents.

A number of prospective randomized comparator studies have suggested that there is a reduction in post-operative nausea and vomiting following maintenance of anaesthesia with propofol compared with inhalational agents. We analysed these studies in more detail by examining the effects of induction agent, choice of inhalation agent, presence/absence of nitrous oxide, age of patient or use of opiate on the incidence of emesis. A search of the Zeneca database MEDLEY was undertaken and prospective randomized comparator studies identified. These were examined individually and independently by two of the authors and log-odds ratios, calculated from the incidence data of each individual trial, were determined and combined using a fixed-effects meta-analysis approach. Patients who received maintenance of anaesthesia with propofol had a significantly lower incidence of post-operative nausea and vomiting in comparison with inhalational agents regardless of induction agent, choice of inhalation agent, presence/absence of nitrous oxide, age of patient or use of opiate.

Xamoterol activates beta 1- but not beta 2-adrenoceptors in mammalian myocardium: comparison of its affinity for beta 1- and beta 2-adrenoceptors coupled to the adenylate cyclase in feline and human ventricle with positive inotropic effects.

The mode of action of xamoterol, a beta 1-selective partial agonist, was investigated in feline myocardium. Xamoterol bound with an 18-fold greater affinity to ventricular beta 1-adrenoceptors (labeled with [3H](-)-bisoprolol) than to beta 2-adrenoceptors (labeled with [3H]ICI 118,551). Xamoterol had a 10-20-fold higher affinity for ventricular beta 1-adrenoceptors coupled to the adenylate cyclase than for cyclase-coupled beta 2-adrenoceptors. The intrinsic activity of xamoterol with respect to (-)-norepinephrine was 0.5 in right ventricular papillary muscles (force), 0.6 in left atria (force); 0.6 in right atria (sinoatrial rate) and 0.1-0.2 in ventricular membranes (cyclase). The stimulant effects of xamoterol were antagonized by beta 1-specific CGP 20,712 A but not by beta 2-selective ICI 118,551. Xamoterol activated only beta 1-adrenoceptors, while beta 2-adrenoceptors occupied by xamoterol remained silent. The positive inotropic effects of a nearly maximally effective xamoterol concentration were associated with a considerably greater beta 1-mediated cyclase stimulation than the same inotropic effect of (-)-norepinephrine. In human ventricular membranes xamoterol stimulated marginally the adenylate cyclase and antagonized the effects of (-)-norepinephrine with a 30-fold greater affinity for beta 1- than for beta 2-adrenoceptors.

The pharmacology of epanolol (ICI 141292)--a new beta 1-selective adrenoceptor partial agonist.

The clinical benefit of beta-adrenoceptor partial agonists is still debated. To clarify the situation, epanolol, ICI 141,292 [N-[-2-(3-o-cyanophenoxy-2-hydroxypropylamino)ethyl]-4- hydroxyphenylactamide], has been developed to assess the role of modest beta-adrenoceptor partial agonist activity in humans. Animal studies have shown that epanolol is a potent beta-adrenoceptor partial agonist with a greater affinity for beta 1- than beta 2-adrenoceptors. In vitro, the PA2 values obtained for espanolol at atrial and tracheal beta-adrenoceptors were 8.42 and 6.33, respectively (isoproterenol as agonist), giving a selectivity ratio of 123. The potency was studied in vivo in the dog, where it was also shown that as an antagonist at the cardiac beta 1-adrenoceptor, it was 18 and 40 times more potent than atenolol and practolol, respectively. Espanolol has less partial agonist activity in the rat than pindolol, but more than practolol. In this species, it is also a classical partial agonist, exhibiting agonist activity at all beta-adrenoceptor blocking doses. This is in contrast to pindolol, which caused predominantly beta-adrenoceptor blockade at low doses and partial agonist activity at higher doses. These differences were confirmed in haemodynamic studies in the dog. In contrast to many other partial agonists, the partition coefficient, log P, of epanolol in octanol and water is low (0.92).

The pharmacology of a beta 2-selective adrenoceptor antagonist (ICI 118,551).

While specific antagonists of the beta 1-adrenoceptor, such as atenolol and betaxolol, are widely available, a potent specific antagonist selective for the beta 2-adrenoceptor has yet to be described. Previously described beta 2-selective antagonists such as butoxamine, H 35/25, and IPS 339 are lacking in potency, specificity, or appropriate beta 2-selectivity. ICI 118,551 [erythro-dl-1-(7-methylindan-4-yloxy)-3-isopropylaminobutan-2-ol] possesses a high degree of selectivity and specificity for the beta 2-adrenoceptor. The affinity of propranolol and ICI 118,551 for beta-adrenoceptors has been determined by comparing their antagonist potencies, expressed as pA2 values, against the actions of isoproterenol on the guinea pig atrium and uterus. ICI 118,551 had a higher affinity for the uterine beta 2-receptor than did propranolol (pA2 9.26 and 8.64, respectively) but a lower affinity for the atrial beta 1-receptor (pA2 7.17 and 8.30, respectively). Thus, the beta 2/ beta 1-selectivity ratios, in vitro, were 123 for ICI 118,551 and 2.2 for propranolol. The potency and selectivity of ICI 118,551 and atenolol on the chronotropic and vasodilator actions of isoproterenol were compared in anaesthetised dogs. The apparent K' B values at the vascular beta-adrenoceptor were 2.1 micrograms/kg for ICI 118,551 and 253 micrograms/kg for atenolol, and the potency ratio for antagonism of vascular versus atrial actions of isoproterenol was greater than 250:1. In regard to ancillary pharmacological properties, ICI 118,551 has no partial agonist activity but has a membrane-stabilising action similar to that of propranolol.

A study of the relationship between cardiac beta-adrenoceptor blockade and intrinsic sympathomimetic activity in rats depleted of catecholamines.

1. The intrinsic sympathomimetic activity of a range of beta-adrenoceptor antagonists and its relationship to beta-adrenoceptor blockade was studied in pentobarbitone-anaesthetized, vagotomized rats which had been depleted of catecholamines by pretreatment with syrosingopine. Dichlorisoprenaline, practolol, oxprenolol, pindolol and acebutolol, produced dose-dependent positive chronotropic responses in this preparation. 2. The relationship between the dose requirements for this intrinsic sympathomimetic activity and beta-adrenoceptor-blocking activity was not the same for all drugs: (i) dichlorisoprenaline and practolol had intrinsic activity at all beta-adrenoceptor-blocking doses; and (ii) oxprenolol, pindolol and acebutolol had predominantly beta-adrenoceptor blockade at the lower dose levels and agonist activity only became significant at high doses relative to those producing beta-adrenoceptor blockade. 3. The positive chronotropic response to both practolol and pindolol was observed in rats which had been pithed and was antagonized by propranolol (0.1-3.0 mg/kg, i.v.), indicating that beta-adrenoceptors were involved. 4. It was concluded that the intrinsic sympathomimetic activity of beta-adrenoceptor antagonists was not a simple property as it was described by the relationship between the dose requirements for intrinsic sympathomimetic activity and for beta-adrenoceptor blockade as well as the degree of partial agonist activity.

An application of receptor models to the analysis of data on beta-adrenoceptor blockade.

1. The classical single receptor competitive occupancy model accurately describes the joint action of an agonist (isoprenaline) and a beta-adrenoceptor antagonist (propranolol) or some partial agonists (dichlorisoprenaline, practolol) on the positive chronotropic response in rats which have been depleted of catacholamines. 2. The mathematical form of the model suggests that the dissociation constants of classical competitive partial agonists may be assessed using dose ratios by exactly the same method as that currently used for agonist-antagonist interactions, provided that the log dose-response curves are first suitably normalized. 3. Close agreement between the theoretical mathematical models and the experimental data can be demonstrated by statistical fitting for certain beta-adrenoceptor antagonists (propranolol, dichlorisoprenaline, practolol). 4. The model fails to describe the behaviour of other beta-adrenoceptor antagonists (oxprenolol, pindolol). A possible extension of the model to include these drugs is proposed.