Registry-derived stage (RD-Stage) for capturing stage at diagnosis for pancreatic carcinoma in Australia

INTRODUCTION

Stage of pancreatic carcinoma at diagnosis is a strong prognostic indicator of morbidity and mortality, yet is poorly notified to population-based cancer registries ("cancer registries"). Registry-derived stage (RD-Stage) provides a method for cancer registries to use available data sources to compile and record stage in a consistent way. This project describes the development and validation of rules to capture RD-Stage (pancreatic carcinoma) and applies the rules to data currently captured in each Australian cancer registry.

MATERIALS AND METHODS

Rules for deriving RD-stage (pancreatic carcinoma) were developed using the American Joint Commission on Cancer (AJCC) Staging Manual 8th edition and endorsed by an Expert Working Group comprising specialists responsible for delivering care to patients diagnosed with pancreatic carcinoma, cancer registry epidemiologists and medical coders. Completeness of data fields required to calculate RD-Stage (pancreatic carcinoma) and an overall proportion of cases for whom RD stage could be assigned was assessed using data collected by each Australian cancer registry, for period 2018-2019. A validation study compared RD-Stage (pancreatic carcinoma) calculated by the Victorian Cancer Registry with clinical stage captured by the Upper Gastro-intestinal Cancer Registry (UGICR).

RESULTS

RD-Stage (pancreatic carcinoma) could not be calculated in 4/8 (50%) of cancer registries; one did not collect the required data elements while three used a staging system not compatible with RD-Stage requirements. Of the four cancer registries able to calculate RD-Stage, baseline completeness ranged from 9% to 76%. Validation of RD-Stage (pancreatic carcinoma) with UGICR data indicated that there was insufficient data available in VCR to stage 174/457 (38%) cases and that stage was unknown in 189/457 (41%) cases in the UGICR. Yet, where it could be derived, there was very good concordance at stage level (I, II, III, IV) between the two datasets. (95.2% concordance], Kendall's coefficient = 0.92).

CONCLUSION

There is a lack of standardisation of data elements and data sources available to cancer registries at a national level, resulting in poor capacity to currently capture RD-Stage (pancreatic carcinoma). RD-Stage provides an excellent tool to cancer registries to capture stage when data elements required to calculate it are available to cancer registries.

Biogas from municipal solid waste landfills: a simplified mathematical model

Municipal solid waste (MSW) landfills now represent one of the most important issues related to the waste management cycle. Knowledge of biogas production is a key aspect for the proper exploitation of this energy source, even in the post-closure period. In the present study, a simple mathematical model was proposed for the simulation of biogas production. The model is based on first-order biodegradation kinetics and also takes into account the temperature variation in time and depth as well as landfill settlement. The model was applied to an operating landfill located in Sicily, in Italy, and the first results obtained are promising. Indeed, the results showed a good fit between measured and simulated data. Based on these promising results, the model can also be considered a useful tool for landfill operators for a reliable estimate of the duration of the post-closure period.

Interobserver and interlaboratory variability of mismatch repair protein expression in ovarian tumors

e17505

Background: Immunohistochemistry (IHC) for mismatch repair (MMR) protein (MLH1, MSH2, MSH6) expression has been a useful strategy for identifying tumors with MMR deficiency. However, despite its wide use, interpretation of results suffers from poor reproducibility. Methods: To assess inter-observer (IO) and inter-laboratory (IL) variability of MMR protein expression, 41 epithelial ovarian cancer (EOC) samples were arrayed in triplicate for construction of a tissue microarray (TMA). Six slides were made from this donor TMA block, of which 3 were stained at the Moffitt Cancer Center (MCC) and 3 were stained at the University of South Florida (USF), using different lab procedures. IHC for MMR protein expression was performed using the avidin-biotin-complex (ABC) method with appropriate controls. Subsequently, all slides were independently scored for protein expression by two pathologists. The Concordance Correlation Coefficient (CCC) value was computed to evaluate IO and IL concordance, with a value >0.75 indicating excellent concordance. Results: The CCC value for the IO analysis was 0.95 (for MCC-stained slides; 95% C.I.: 0.89–0.98) and 0.85 (for USF-stained slides; 95% C.I.: 0.66, 0.93), indicating excellent concordance. The CCC value for IL analysis was 0.53 (95% C.I.: 0.37–0.66). Conclusions: Our findings demonstrate that variability in IHC protocols may contribute to the interpretation of IHC results. Our data suggest that when pathologists are given the same slide, there is excellent agreement between two observers; however, when the same slides are stained in a separate laboratory using the same method (ABC) but different protocol, there may be considerable disagreement. These findings are of great clinical significance due to the widespread use of IHC as diagnostic, prognostic and therapeutic tools in cancer care.

No significant financial relationships to disclose.

Characterization of anaplasma infections in Sicily, Italy

This study aimed to characterize infection with Anaplasma marginale, A. phagocytophilum, A. ovis, and A. platys in humans, animals, and ticks in Sicily, Italy, during 2003-2006. Serologic (competitive ELISA [cELISA]) and indirect immunofluorescence antibody [IFA]; N= 1990) and DNA (polymerase chain reaction [PCR]; N= 2788) tests were conducted on horse, donkey, cattle, sheep, goat, pig, dog, cat, roe deer, wild boar, human, and tick samples. The results reported herein suggested that in Sicily cattle are a major reservoir for A. marginale, dogs for A. platys, and sheep and goats for A. ovis. Domestic animals, such as cattle, horses, donkeys, sheep, dogs, and cats, may serve as reservoir for A. phagocytophilum, but different strains may infect ruminants and humans. All Anaplasma spp. characterized in Sicily had some distinctive genotypes for this region. Low genetic diversity was observed in A. ovis and A. platys, whereas A. marginale and A. phagocytophilum strains showed high genetic diversity. These results expanded our knowledge about the prevalence of Anaplasma spp. in Sicily and provided information to understand the epidemiology of these infections and implement measures to diagnose, treat, and control transmission to humans and animals in this region.

Observed Prevalence of Tick-borne Pathogens in Domestic Animals in Sicily, Italy during 2003?2005

The objective of this study was to characterize the observed prevalence of tick-borne pathogens (TBP) in domestic animals in Sicily, Italy during 2003-2005. Serological (competitive ELISA and indirect immunofluorescence antibody, n = 3299) and DNA tests (polymerase chain reaction and reverse line blot, n = 2565) were conducted on horse, donkey, cattle, sheep, goat, pig and dog samples. Pathogens analysed included Anaplasma, Ehrlichia, Rickettsia, Babesia and Theileria species, and Coxiella burnetii. The most prevalent TBP were Anaplasma and Babesia species. The results reported herein suggested that cattle could serve as the major reservoir for Babesia and Theileria spp. while for Anaplasma spp. cattle, dogs, sheep and goats may be the most important reservoir species. These results expanded our knowledge about the prevalence of TBP in Sicily and provided information to understand the epidemiology of tick-borne diseases and may help to implement measures to diagnose, treat and control transmission to humans and animals in this region.

Hybrid test bench for evaluation of any device related to mechanical cardiac assistance

Hydraulic mock circulatory systems have low flexibility to allow tests of different cardiovascular devices and low precision when a reference model must be reproduced. In this paper a new bench is described. It combines the computer model of the environment in which the device will operate and the electro-hydraulic interfaces by which device and computer are connected. A models library provided with basic functions allows implementing many layouts of the bench, which in turn depend both on the device properties and the desired experiment. In case of an apical LVAD evaluation, the bench can reproduce right and left ventricles, pulmonary and systemic circulations, inlet and outlet LVAD cannulas. An interface forces the instantaneous calculated flow at the VAD input and feeds back the measured pressure to the computer; another interface works in a similar -but complementary- way at the VAD output. The paper focuses on the operating principle of the electro hydraulic interfaces which represent a relevant component of the bench, on the RT-Linux-based software architecture, on the models of the basic elements of the bench. A patent is under preparation. At the moment, only a portion of the bench has been developed. It consists of a piston-cylinder mechanism, which mimics the elastance-based mechanism of a natural ventricle, and a hydraulic circuit representing the arterial load according to a modified windkessel model and the venous return according to the Guyton's model. The pump is driven by a real-time simulation of the cardiovascular system. This preliminary layout allowed testing the piston-cylinder mechanism, its control, and the software. This electro-hydraulic interface has been used to reproduce a pulsatile pump working in different modes. The hybrid model approach can support the development of new cardiac assist devices from their computer model to their manufacture.

Leukotrienes as mediators of asthma

This review describes the aspects of leukotriene (LT) pharmacology and biology that are relevant to their important role in asthma. The biosynthesis and metabolism, including transcellular metabolism, of LTB4 and the cysteinyl-LTs (i.e. LTC4, LTD4 and LTE4) are described, and their transport is briefly outlined. The existence, distribution and pharmacological characterization of the receptors (BLT, CysLT1, CysLT2), as well as the transduction mechanisms triggered, are discussed in detail. We also describe their effects on airway smooth muscle tone, hyperresponsiveness and proliferation, on vascular tone and permeability, on mucus secretion, on neural fibers and inflammatory cell functions. Finally, the evidence supporting their role as asthma mediators is reviewed, including the effects of anti LT drugs (both biosynthesis inhibitors and receptor antagonists) in experimental and clinical asthma.

Leukotriene D4-induced activation of smooth-muscle cells from human bronchi is partly Ca2+-independent

Cysteine-containing leukotrienes (cysteinyl-LTs) are potent bronchoconstrictors and play a key role in asthma. We found that histamine and LTD4 markedly constrict strips of human bronchi (HB) with similar efficacy. However, in human airway smooth-muscle (HASM) cells, LTD4, at variance with histamine, elicited only a small, transient change in intracellular calcium ion concentration. HASM cells express both Ca2+-dependent and -independent isoforms of protein kinase C (PKC) (i.e., PKC-alpha and PKC-alpha ). Western blot analysis showed that PKC-alpha is activated by histamine and, to a lesser extent, by LTD4, whereas only LTD4 translocates PKC-alpha. This translocation was specifically inhibited by the LTD4 antagonist pobilukast. Phorbol-dibutyrate ester (PDBu) (a PKC activator) contracted HB strips to the same extent in the presence as in the absence of extra- and intracellular Ca2+. In the absence of Ca2+, LTD4 contracted HB strips to the same extent as did PDBu, suggesting the involvement of a Ca2+-independent PKC in LTD4-mediated signal transduction. PDBu-induced desensitization and the PKC inhibitor H7 abolished the slow and sustained LTD4-triggered contraction of HB strips in the absence of Ca2+, although H7 did not greatly affect the response in the presence of the ion. Thus, in human airways, we identified a novel LTD4 transduction mechanism linked to bronchial smooth-muscle contraction, which is partly independent of Ca2+ and involves the activation of PKC-alpha.

A kinetic binding study to evaluate the pharmacological profile of a specific leukotriene C(4) binding site not coupled to contraction in human lung parenchyma

We report the identification of a novel pharmacological profile for the leukotriene (LT)C(4) binding site we previously identified in human lung parenchyma (HLP). We used a series of classic cysteinyl-LT (CysLT)(1) receptor antagonists belonging to different chemical classes and the dual CysLT(1)-CysLT(2) antagonist BAY u9773 for both binding and functional studies. Because the presence of (S)-decyl-glutathione interfered with cysteinyl-LT binding, with a kinetic protocol we avoided the use of this compound. By means of heterologous dissociation time courses, we demonstrated that zafirlukast, iralukast, and BAY u9773 selectively competed only for (3)H-LTD(4) binding sites, whereas pobilukast, pranlukast, and CGP 57698 dissociated both (3)H-LTC(4) and (3)H-LTD(4) from their binding sites. Thus, with binding studies, we have been able to identify a pharmacological profile for LTC(4) distinct from that of LTD(4) receptor (CysLT(1)) in HLP. On the contrary, in functional studies, all of the classic antagonists tested were able to revert both LTC(4)- and LTD(4)-induced contractions of isolated HLP strips. Thus, LTD(4) and LTC(4) contract isolated HLP strips through the same CysLT(1) receptor. The results of kinetic binding studies, coupled to a sophisticated data analysis, confirm our hypothesis that HLP membranes contain two cysteinyl-LT high-affinity binding sites with different pharmacological profiles. In functional studies, however, LTD(4)- and LTC(4)-induced contractions are mediated by the same CysLT(1) receptor. In conclusion, the specific LTC(4) high-affinity binding site cannot be classified as one of the officially recognized CysLT receptors, and it is not implicated in LTC(4)-induced HLP strip contractions.

Ofloxacin for the treatment of urinary tract infections and biofilms in spinal cord injury

Forty two paraplegic and quadriplegic hospitalized spinal cord injured patients with urinary tract infections (UTI) were included in a double blind, randomized treatment study comparing 7 days ofloxacin (300 mg bd) with trimethoprim-sulphamethoxazole (TMPSMX; 160-800 mg bd) or an alternative, chosen because of resistance to TMPSMX. The 4-day clinical cure rate, defined as an asymptomatic patient with sterile urine, was 90% (19/21) with ofloxacin, significantly greater than 48% (10/21) for the comparison group (P=0.003) and the rate at end of therapy was 90% (19/21) with ofloxacin, against 57% (12/21) (P=0.015). Bacterial biofilms were detected on bladder epithelial cells in 39/41 (95%) patients. The biofilm score fell significantly following ofloxacin therapy (P < 0.001) or alternative therapy (P < 0.001). Ofloxacin treatment led to significantly more biofilm eradication than the other antibiotic group on day 4 (62 vs. 24%) (P=0.005) and day 7 (67 vs. 35%) (P=0.014). The study showed that ofloxacin was better than TMPSMX and alternatives at relieving clinical infection and eradicating bladder cell biofilms.

Do pipecuronium and rocuronium affect human bronchial smooth muscle?

BACKGROUND

Muscle relaxants affect nicotinic and muscarinic receptors. Interaction of muscle relaxants with muscarinic receptors of human airways has been studied incompletely.

METHODS

The effects of pipecuronium bromide (long-acting, nondepolarizing) and rocuronium bromide (intermediate-acting, nondepolarizing) on prejunctional and postjunctional muscarinic receptors were studied in 96 isolated human bronchial rings from 12 patients. Contractile isometric responses to electric field stimulation of pilocarpine-stimulated and nonstimulated M2 muscarinic receptors were compared before and after incubation with the two muscle relaxants. The effect on postjunctional muscarinic receptors was studied by comparing acetylcholine concentration-response curves before and after incubation with the two muscle relaxants.

RESULTS

Pipecuronium bromide, but not rocuronium bromide, inhibited pilocarpine-stimulated prejunctional M2 muscarinic receptors. Neither pipecuronium bromide nor rocuronium bromide had significant inhibitory effects on nonstimulated M2 muscarinic receptors and on postjunctional M3 muscarinic receptors.

CONCLUSIONS

The inhibitory effect of pipecuronium bromide on pilocarpine-stimulated prejunctional M2 muscarinic receptors occurred at clinical concentrations.

[Antileukotriene drugs: a new treatment for asthma]

Asthma incidence and prevalence have significantly increased during the last 25 years, making this pathology to be one of the most diffused in the industrialized world. It affects 5% of the adult population and the 10-15% of the children. The aethipathogenesis of asthma clearly involves a number of mediators, among which leukotrienes play an important role inducing bronchoconstriction, oedema and mucus hypersecretion. Thus, compounds inhibiting either the action or formation of these mediators are potentially interesting as antiasthma drugs. Two strategies for modulating the actions of the leukotrienes are currently undergoing clinical evaluation: cysteinyl leukotriene receptor antagonism and 5-lipoxygenase (5-LO) inhibition. These two classes of agents are here reviewed and their clinical utility as antiasthma drugs is evaluated.

Pharmacodynamic properties of leukotriene receptor antagonists

Leukotrienes (LTs) are among the most important mediators of asthma; cysteine-containing LTs (cysteinyl-LTs, i.e. LTC4, LTD4 and LTE4) are very potent bronchoconstrictors and participate in the inflammatory component of asthma by inducing mucus hypersecretion, plasma extravasation, mucosal oedema and eosinophil recruitment. Therefore, compounds able to inhibit either the formation or the action of LTs are potential antiasthma drugs and, at present, the cysteinyl-LT receptor antagonists (LTRAs) appear to be the most promising. The receptors for cysteinyl-LTs, termed CysLT receptors, are heterogeneous; at least two different classes have so far been recognized, named CysLT1 (blocked by the so-called classical antagonists, such as FPL 55712, ICI 198,615, ICI 204,219, SK&F 104353, MK-476 and others) and CysLT2 (insensitive to the classical antagonists, but sensitive to BAY u9773). The authors' results indicate that even more receptor subclasses might exist in human airways, which discriminate between LTC4 and LTD4, both asthma mediators. Among the many LTRAs, zafirlukast (Accolate, ICI 204,219), montelukast (Singulair, MK-476) and pranlukast (Onon, ONO-1078) are available for clinical use. All the LTRAs are able to inhibit LTD4-induced bronchoconstriction in humans, albeit with different potencies. With respect to antigen challenge, all of them inhibit the early phase of response, whereas only the most recently developed and potent ones are effective in the late phase. LTRAs are effective in asthma triggered by exercise, cold or aspirin. Furthermore, although they are not bronchodilators per se, they increase basal forced expiratory volume in one second in patients with mild-to-moderate asthma, indicating that, in these individuals, constant cysteinyl-LT release contributes to maintaining increased bronchial tone. Finally, the effect of LTRAs is additive to that of beta-agonists and is potentiated by antihistamine compounds. In conclusion, the available results clearly indicate that leukotrienes play an important role in asthma and that cysteinyl leukotriene receptor antagonists are very promising antiasthma drugs.

Heterogeneous platelet-activating factor (PAF) receptors and calcium increase in platelets and macrophages

We used the increase in cytosolic Ca2+ levels, [Ca2+]i, as a way to characterize PAF (platelet-activating factor, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) receptors in human platelets and rat and human macrophages. [Ca2+] was measured by means of the fluorescent probe fura-2/acetoxymethylester. PAF recognized heterogeneous receptors in human macrophages only (curve slope <1). The PAF antagonist SCH 37370 (1-acetyl-4(8-chloro-5,6-dihydro-11H-benzo[5.6]cyclohepta[1,2-b]pyridine -11-ylidine)piperidine) abolished [Ca2+]i elevation in human platelets, while in rat and human macrophages the maximal inhibition was 76% and 85%, respectively. On the contrary, the antagonist WEB 2086 (3-[4-(2-chlorophenyl)-9-methyl-6Hthieno[3,2-f] [1,2,4]triazolo-[4,3-a] [1,4]-diazepin-2-yl]-1-(4-morpholiny)-1-propanon, apafant) totally inhibited the effect of PAF in both platelets and macrophages. The WEB 2086 concentration-response curves had a slope <1 in the three cell types, indicating interaction with heterogeneous receptors. Accordingly, 3H-WEB 2086 bound to two different classes of sites. Both phases of [Ca2+]i elevation (influx or release) were equally affected by the antagonists. These data support the notions that: 1) PAF receptors are heterogeneous; 2) the two antagonists have a different selectivity toward the receptor subtypes: WEB 2086 recognizes two different receptors both in platelets and in macrophages, while SCH 37370 does not discriminate between receptor subtypes in platelets, and only interacts with one subtype in macrophages; and 3) both SCH 37370 and WEB 2086 display different potencies in rat and human macrophages.

Identification and characterization of two cysteinyl-leukotriene high affinity binding sites with receptor characteristics in human lung parenchyma

We report the characterization of two distinct binding sites with receptor characteristics for leukotriene (LT)D4 and LTC4 in membranes from human lung parenchyma. The use of S-decyl-glutathione allowed us to characterize a previously unidentified high affinity binding site for LTC4. Computerized analysis of binding data revealed that each leukotriene interacts with two distinct classes of binding sites (Kd = 0.015 and 105 nM for LTC4 and 0.023 and 230 nM for LTD4) and that despite cross-reactivity, the two high affinity sites are different entities. LTD4 binding sites displayed features of G protein-coupled receptors, whereas LTC4 binding sites did not show any significant modulation by guanosine-5'-(beta, gamma-imido)triphosphate or stimulation of GTPase activity. The antagonists ICI 198,615 and SKF 104353 were unselective for the high and low affinity states of LTD4 receptor, whereas only SKF 104353 was able to recognize the two [3H]LTC4 binding sites although with different affinities. These data indicate that in human lung parenchyma, LTD4 and LTC4 recognize two different binding sites; these binding sites are different entities; and for LTD4, the two binding sites represent the interconvertible affinity states of a G protein-coupled receptor, whereas for LTC4, the high affinity site is likely to be a specific LTC4 receptor.

Pharmacological characterization of the cysteinyl-leukotriene antagonists CGP 45715A (iralukast) and CGP 57698 in human airways in vitro

1. Cysteinyl-leukotrienes (cysteinyl-LTs) are important mediators in the pathogenesis of asthma. They cause bronchoconstriction, mucus hypersecretion, increase in microvascular permeability, plasma extravasation and eosinophil recruitment. 2. We investigated the pharmacological profile of the cysteinyl-LT antagonists CGP 45715A (iralukast), a structural analogue of LTD4 and CGP 57698, a quinoline type antagonist, in human airways in vitro, by performing binding studies on human lung parenchyma membranes and functional studies on human isolated bronchial strips. 3. Competition curves vs [3H]-LTD4 on human lung parenchyma membranes demonstrated that: (a) both antagonists were able to compete for the two sites labelled by [3H]-LTD4; (b) as in all the G-protein coupled receptors, iralukast and CGP 57698 did not discriminate between the high and the low affinity states of the CysLT receptor labelled by LTD4 (Ki1=Ki2= 16.6 nM+/-36% CV and Ki1= Ki2 = 5.7 nM+/-19% CV, respectively); (c) iralukast, but not CGP 57698, displayed a slow binding kinetic, because preincubation (15 min) increased its antagonist potency. 4. In functional studies: (a) iralukast and CGP 57698 antagonized LTD4-induced contraction of human bronchi, with pA2 values of 7.77+/-4.3% CV and 8.51+/-1.6% CV, respectively, and slopes not significantly different from unity; (b) the maximal LTD4 response in the presence of CGP 57698 was actually increased, thus clearly deviating from apparent simple competition. 5. Both antagonists significantly inhibited antigen-induced contraction of human isolated bronchial strips in a concentration-dependent manner, lowering the upper plateau of the anti-IgE curves. 6. In conclusion, the results of the present in vitro investigation indicate that iralukast and CGP 57698 are potent antagonists of LTD4 in human airways, with affinities in the nanomolar range, similar to those obtained for ICI 204,219 and ONO 1078, two of the most clinically advanced CysLT receptor antagonists. Thus, these compounds might be useful drugs for the therapy of asthma and other allergic diseases.

Characterization of the Ca2+ responses evoked by ATP and other nucleotides in mammalian brain astrocytes

1. This study was aimed at characterizing ATP-induced rises in cytosolic free calcium ion, [Ca2+]i, in a population of rat striatal astrocytes loaded with the fluorescent Ca2+ probe Fura2, by means of fluorescence spectrometry. 2. ATP triggered a fast and transient elevation of [Ca2+]i in a concentration-dependent manner. The responses of the purine analogues 2-methylthio-ATP (2-meSATP), adenosine-5'-O-(2-thiodiphosphate) (ADP beta S), as well as uridine-5'-triphosphate (UTP) resembled that of ATP, while alpha, beta-methylene-ATP (alpha, beta-meATP) and beta, gamma-methylene-ATP (beta, gamma-meATP) were totally ineffective. 3. Suramin (50 microM) had only a minor effect on the ATP response, whereas pyridoxal phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) (5 microM) significantly depressed the maximum response. 4. Extracellular Ca2+ did not contribute to the observed [Ca2+]i rise: removing calcium from the extracellular medium (with 1 mM EGTA) or blocking its influx by means of either Ni2+ (1 mM) or Mn2+ (1 mM) did not modify the nucleotide responses. 5. Furthermore, after preincubation with 10 microM thapsigargin, the nucleotide-evoked [Ca2+]i increments were completely abolished. In contrast, 10 mM caffeine did not affect the responses, suggesting that thapsigargin-, but not caffeine/ryanodine-sensitive stores are involved. 6. Both application of the G-protein blocker guanosine-5'-O-(2-thiodiphosphate) (GDP beta S) (1 mM) and preincubation with pertussis toxin (PTx) (350 ng ml-1) partially inhibited the nucleotide-mediated responses. Moreover, the phospholipase C (PLC) inhibitor U-73122, but not its inactive stereoisomer U-73343 (5 microM), significantly reduced the ATP-evoked [Ca2+]i rise. 7. In conclusion, our results suggest that, in rat striatal astrocytes, ATP-elicited elevation of [Ca2+]i is due solely to release from intracellular stores and is mediated by a G-protein-linked P2Y receptor, partially sensitive to PTx and coupled to PLC.

Functional magnetic resonance imaging: a potential tool for the evaluation of spinal cord stimulation: technical case report

OBJECTIVE AND IMPORTANCE

The management of chronic pain of spinal origin continues to represent a challenge for neurosurgeons. Spinal cord stimulation for chronic intractable pain is an effective therapy in approximately 50% of patients. The present study uses a novel imaging approach, functional magnetic resonance imaging (fMRI), to examine the central effects of spinal cord stimulation.

CLINICAL PRESENTATION

Three patients, each with a chronic history of intractable pain, were treated at the Toronto Hospital with a trial of dorsal column stimulation (DCS). For all patients, significant improvement in pain symptoms was achieved with DCS.

INTERVENTION

fMRI on a 1.5-T conventional magnetic resonance system was used to study the effects of DCS in these patients. Images were collected while the stimulator was activated and deactivated.

CONCLUSION

This report is the first to describe the cerebral effects of exogenous spinal cord stimulation with fMRI. fMRI allows for the objective examination of the effects of DCS and may provide an objective means of evaluating the efficacy of DCS as a therapy for intractable pain of spinal origin.

Internalization and down-regulation of the prostacyclin receptor in human platelets

The internalization of [3H]iloprost, a prostacyclin analogue, was studied in human platelets by binding studies. After incubation with [3H]iloprost at 37 degrees C, addition of unlabelled ligand at either 37 degrees C or 4 degrees C caused dissociation of 74% and 52% of the bound ligand respectively, suggesting that a portion had been internalized. The percentage of [3H]iloprost bound at equilibrium to the surface (evaluated by acid treatment) at either 37 degrees C or 4 degrees C was markedly different (80% versus 25%). Internalization was dependent on time and on the ligand nature and concentration. Energy-depleting agents (dinitrophenol and 2-deoxyglucose) completely inhibited internalization, whereas probenecid (inhibitor of organic anion transporters) did not affect it significantly. Subcellular fractionation indicated that, at 4 degrees C or in the absence of ligand, most of the receptor was present in membrane fractions (pellet at 27000 or 105000 g), whereas, when platelets were preincubated at 37 degrees C with iloprost, the receptor was found mainly in the cytosolic fraction. In platelets preincubated with iloprost at 4 degrees C, two classes of binding sites were present, whereas after preincubation at 37 degrees C only the lower-affinity sites were detected. After exposure to the agonist, iloprost-induced inhibition of platelet aggregation and activation of adenylate cyclase and cAMP production were significantly lower. Taken together, these data demonstrate that human platelets can internalize a high-affinity binding site for iloprost, presumably the prostacyclin receptor.

Inhibition of airway constriction by opioids is different down the isolated bovine airway

BACKGROUND

Opioid agonists attenuate in isolated airways contractile responses to electrical field stimulation (EFS), and this attenuation is mediated by opioid receptors. Differences exist in the density of muscarinic and beta-adrenergic receptors between large and small airways. The authors hypothesized that the density of opioid receptors may also be different down the airway.

METHODS

The effects of three selective opioid agonists (mu, kappa, delta) on EFS-induced contractions were compared between isolated bovine sublobar (4- or 5-mm inner diameter) and segmental (2- or 3-mm inner diameter) bronchial rings and between trachealis strips and bronchial rings.

RESULTS

D-Ala2-N-MePhe4-Gly-ol5 enkephalin (DAMGO; 10(-5) M), a mu-opioid agonist, attenuated EFS-induced contractions of isolated sublobar and segmental bronchial rings at low stimulating frequencies of 0.5 Hz (P < 0.001), 2 Hz (P < 0.001), and 8 Hz (P < 0.001), but not at 32 Hz (P = 0.071). The inhibitory effect of DAMGO was antagonized by naloxone (10(-5) M) (P = 0.025). The selective kappa-opioid agonist U-50488 H (10(-5) m) attenuated EFS-induced contractions at 32 Hz (P = 0.008) and 8 Hz (P = 0.045), but not at 2-Hz (P = 0.893) or 0.5-Hz (P = 0.145) contractions. The inhibitory effects of 10(-5) M U-50488 H were not antagonized by the highly selective kappa-antagonist 2,2'-[1,1'-biphenyl] 4,4'-diyl-bis [2-hydroxy-4,4-dimethyl]-morpholinium (nor-BNI; 10(-5) M; P = 0.216) or naloxone (10[-5]) M; P = 0.065). The selective delta-agonist D-penicillamine2-D-penicillamine5-enkephalin (DPDPE) (10(-5) M) had no inhibitory effects (P = 0.256). The inhibitory effects of the selective mu-opioid agonist DAMGO were smaller (P < 0.001) and those of U-50488 H larger (P < 0.001) in trachealis strips compared with bronchial rings.

CONCLUSIONS

The attenuation of EFS-induced contractions by DAMGO in isolated bovine bronchi was mediated by prejunctional opioid receptors. In contrast, the inhibitory effect of U-50488 H was probably not mediated by opioid receptors in the bronchi.

The Role of Selective Lymphadenectomy in Breast Cancer

BACKGROUND: Axillary node dissection is considered a standard staging procedure in patients with breast cancer. The procedure is associated with significant morbidity and provides pathologists with many lymph nodes to evaluate. METHODS: A total of 174 women participated in a trial that included preoperative lymphoscintigraphy and intraoperative lymphatic mapping using a combination of a vital blue dye and radiocolloid mapping. RESULTS: The intraoperative lymphatic mapping correctly identified a sentinel lymph node (SLN) in 160 (92%) of 174 patients. One skip metastasis (0.7%) occurred in 136 women who had a subsequent complete node dissection. CONCLUSIONS: Lymphatic mapping and SLN biopsy using a combination of mapping techniques provide accurate nodal staging for women with breast cancer. With this technique, approximately 70% to 80% of women with no axillary metastases could be spared the morbidity of a complete node dissection.

Effect of the new calcium antagonist lercanidipine and its enantiomers on the migration and proliferation of arterial myocytes

The in vitro effects were investigated of the new dihydropyridine calcium antagonist (CA) lercanidipine and its enantiomers on arterial myocyte (smooth muscle cell; SMC) migration and proliferation as related to L-type calcium channel inhibition. Lercanidipine and its enantiomers inhibited the replication and migration of arterial myocytes in concentration ranging from 10 to 50 microM. The antiproliferative effect of lercanidipine, evaluated as cell number, was dose dependent, with a potency similar to that of lacidipine and nifedipine, and was unrelated to the stereoselectivity of enantiomers to bind L-type calcium channels. The cell doubling time increased with drug concentration < or = 122 versus 38 h for controls. The cell growth inhibition induced by lercanidipine and its enantiomers was reversible. Lercanidipine dose dependently decreased [3H]thymidine incorporation into DNA; the (R)-enantiomer, displaying the lowest CA activity, was the most potent in this respect. The tested compounds were able to inhibit fibrinogen-induced myocyte migration in a dose-dependent manner, with the (R)-enantiomer showing the more pronounced effect. To directly rule out the role of calcium channels in the antiatherosclerotic properties of lercanidipine, we examined the effect of the compounds on serum-stimulated calcium influx in SMC. Fluorimetry of Fluo 3 was used to measure changes in free cytosolic Ca2+ concentration ([Ca2+]i) in SMC after long-term preincubation (24 h) with the tested CA. Lercanidipine and its enantiomers (25 microM) decreased the serum-induced elevation of [Ca2+]i in SMC with the (S)-enantiomer (69% inhibition) 2.4-fold more active than the counterpart and the racemate (29% inhibition). In conclusion, our in vitro results suggest that lercanidipine may directly interfere with events involved in atherogenesis. The studies performed with enantiomers of lercanidipine suggest that the observed effects are not related to the blockade of voltage-dependent Ca2+ channels and confirm at least in vitro a pharmacologic potential of the compound to negatively influence the process of atherogenesis.

KINFIT II: a nonlinear least-squares program for analysis of kinetic binding data

We describe a versatile computer program for least-squares fitting of ligand/receptor association and dissociation curves from several experiments simultaneously. The program is designed to handle any number of classes of binding sites reacting with a single ligand that may have two forms: labeled and unlabeled. For a single class of binding sites, the exact, analytical solution is used to generate the computed curves. For more than one class of sites, the computed curves are generated through numerical solution of a set of ordinary differential equations. The parameters determined with this procedure are the on- and off-rate constants and the concentrations of each binding site class. An extensive selection of experimental designs can be processed. The times of observation may be freely chosen, although that choice will affect the quality of the results. Starting with a sample material (e.g., cells, membranes, macromolecules), one can preincubate (to equilibrium) with any combination of labeled and unlabeled ligand. One can then perturb the system by adding any combination of labeled and cold ligand or simply diluting the sample; such an experiment can be continued through several perturbations. A variety of such runs may be combined for analysis as a single data set.

[Cardiac involvement in familial amytrophic chorea with acantocytosis: description of two new clinical cases]

Familial amyotrophic chorea and acanthocytosis, also known as the Levine-Critchley syndrome, is a rare inherited disease characterized primarily by central nervous system involvement with progressive demyelinization and autosomic or dominant transmission. Clinical symptoms include orofaciolingual dyskinesia and involuntary choreiform movements associated with skeletal muscle atrophy due to axonal demyelinization and erythrocyte acanthocytosis. A few patients have some cardiac abnormality, including an electrocardiographic pattern of left ventricular hypertrophy, left atrial wave abnormalities, non-specific ST-T wave changes, and a pseudonecrosis pattern with abnormal Q waves in the inferior leads. Two-dimensional echocardiography has disclosed concentric ventricular hypertrophy and the typical findings of congestive cardiomyopathy. We report the case of two brothers, 40 and 58 years old, who had asymmetric left ventricular hypertrophy (more marked in the younger brother), left ventricular mass index increase unrelated to a hypertensive state or the percent of circulating acanthocytes. Functional systolic parameters were normal. The younger brother had dilation of the aortic root and marked enlargement of the non-coronary Valsalva sinus, and both patients manifested mitral leaflet redundancy without evident prolapse. Our observations suggest the hypothesis that connective tissue and/or vessel muscle-elastic fiber pathology is associated with the well-known neurological disorders typical of the Levine-Critchley syndrome. It is thus advisable that these patients undergo thorough cardiovascular evaluation.

Scoring acute spinal cord injury: a study of the utility and limitations of five different grading systems

We recorded Frankel Scale, Yale Scale, Motor Index Score, Modified Barthel Index, Functional Independence Measurement scores, and important clinical parameters simultaneously and repetitively for 35 consecutive acute spinal cord injury patients. We found that 1) these scores can be determined as long as "yes/no" communication can be obtained reliably, pharmacological paralysis is not present, and a reliable observer with a flexible schedule is available, 2) impairment based scores (FS, YS, MIS) have little tendency to change during acute care, 3) function based scales (MBI, FIM) can be distorted by acute care phenomena which limit self care, 4) impairment-based and disability-based scales do not convert reliably, 5) none of these scales correlated strongly with common milestones for mobility or nutrition and 6) a good description of a population of ASCI patients can be made by a combination of two scales, one based on impairment and the other on disability.

myc-immortalized microglial cells express a functional platelet-activating factor receptor

The autacoid platelet-activating factor (PAF) takes part in a complex network of interactions regarding the cellular components of nervous tissues. Efforts aimed at characterizing the effects of PAF in the brain have been recently focalized on neurons because PAF exerts pleiotropic effects on these cells. Less attention has instead been paid to the glial component of the brain. We have used microglial cell lines immortalized from 13-day-old mouse embryo brains by a myc-transducing retrovirus. When exposed to physiological doses of PAF, immortalized microglial cells showed increases in intracellular free calcium concentrations due to release of calcium from internal stores, as well as to extracellular calcium influxes. These profiles of reactivity were independent from the immortalizing process, being observable in primary microglial cultures and in immortalized clones showing different proliferative rates. PAF was also able to induce transient expression of the c-fos protooncogene in serum-starved cultures and induced a strong chemotactic response in microglial cells. In contrast with control macrophage cultures, PAF did not promote prostaglandin or leukotriene synthesis in immortalized cells. This was most likely due to the low amount of total arachidonic acid found in immortal microglia, with respect to that observed in freshly isolated cells. Our data suggest that several of the effects observed after PAF stimulation might be independent from PAF-induced arachidonic acid metabolism. The availability of an in vitro microglial model might now help in studying the proinflammatory effects of PAF, both direct or microglia mediated, in the neural environment.

Stereochemical analysis and biological activity of 3-hydroxy-leukotriene B4: a metabolite from ethanol-treated rat hepatocytes

Leukotriene B4 (LTB4), a biologically active metabolite derived from arachidonic acid by the 5-lipoxygenase cascade, is inactivated by cytochrome P-450-dependent omega-hydroxylation followed by second oxidation into a omega-carboxyl group. In many tissues, this second step is mediated by alcohol dehydrogenase. Isolated rat hepatocytes metabolized LTB4 in the presence of ethanol and ethoxyresorufin into substantial quantities of 3-hydroxy-LTB4 as determined by mass spectrometry. The absolute configuration of this metabolite was found to be greater than 98% 3(S)-hydroxy-LTB4 by comparison to synthetic standards. Investigation of the pharmacologic properties of the 3(S)- and 3(R)-hydroxy-LTB4 revealed that both caused a significant increase in intracellular free calcium in human neutrophils at 1 microM. Both enantiomers also induced thromboxane A2 release from the isolated guinea pig lung in a dose-dependent manner. This activity was fully blocked by a specific LTB4 receptor antagonist, LY223982, with an IC50 of 0.21 microM for LTB4. These results suggested that activation of the LTB4 receptor does not involve significant recognition of the carbon atoms close to the carboxyl moiety of LTB4. The failure of the hepatocyte to metabolically inactivate LTB4 in the presence of ethanol may be of importance to humans, particularly because the bioactive metabolite 3(S)-hydroxy-LTB4 was further metabolized by human neutrophils significantly more slowly than LTB4.

[Does aortic insufficiency influence Doppler-derived calculation of the valvular area in patients with mitral stenosis?]

BACKGROUND

The evaluation of mitral valve area (MVA) in patients with mitral stenosis represents the main purpose of any diagnostic method, provided that MVA is a key parameter to indicate the need for valve surgery. The aim of this study was to assess whether the presence of aortic regurgitation associated with mitral stenosis affects the MVA measurement by left atrial pressure half time (PHT).

METHODS

Eighty-nine patients with mitral valve stenosis (68 females and 21 males, mean age 53.6 +/- 12.1 years), were studied. Fourty-eight patients (36 females and 12 males) had a concomitant aortic regurgitation (AR group), whereas 41 patients (32 females and 9 males) did not reflect any aortic valve involvement (no-AR group). Aortic regurgitation was graded on the basis of color flow analysis. The majority of patients had a slight to moderate regurgitation. MVA determination was carried out using both Hatle formula (220/PHT) and planimetric measurement in parasternal short axis view.

RESULTS

Statistical analysis demonstrated a good correlation between the 2 MVA measurement in both groups (IA group: r = 0.9, p < 0.0001, SSE = 0.21 cm2, y = 0.91x + 0.05; no-IA group r = 0.92, p < 0.0001, SSE = 0.22 cm2, y = 0.92x + 0.04). The concomitant aortic valve disease did not affect in any way the MVA measurement by means of the PHT method.

CONCLUSIONS

The Doppler derived method appears to be reliable for estimating the mitral valve area in patients with mitral stenosis even in the presence of aortic regurgitation.

Thrombin generation in patients undergoing carotid endarterectomy: implications in acute vessel wall closure and antithrombotic therapy

We determined the extent and duration of activation of coagulation during the first 24 hours after carotid endarterectomy. Serial blood samples were collected before, during and after surgery from 10 patients with severe stenosis (> 70%) undergoing carotid endarterectomy with heparinization. Platelet poor plasmas prepared from these samples, were analysed for activated prothrombin fragment F1 + 2 and thrombin-antithrombin III (TAT) levels, using commercially available ELISA kits. F1 + 2 and TATs were measured as indices of thrombin generation and inhibition respectively. Baseline F1 + 2 and TAT levels were 1.19 +/- 0.27 nMol/ml and 17 +/- 10 pMol/ml, respectively. Neither the F1 + 2 nor TAT level increased during surgery at a time when the patients were heparinized. However, both the F1 + 2 and TAT levels increased significantly within 3 hours after surgery and after the heparin had been neutralized with protamine, (p < 0.01). Moreover, both the F1 + 2 and TAT levels remained elevated in 75% of the patients for at least 24 hours, p < 0.01. We conclude that i) thrombin generation is significant post surgery in patients undergoing carotid endarterectomy despite their receiving heparin during surgery; ii) heparin may not be the ideal anticoagulant for carotid endarterectomy; and iii) persistent thrombin generation may contribute to early post-endarterectomy ischemic events.

Functional glucocorticoid receptor modulates pancreatic carcinoma growth through an autocrine loop

Several peptide hormones have been shown to influence growth and function in pancreatic carcinoma and have given evidence for an autocrine feedback loop governing the proliferation of these malignant cells. Conversely, steroid hormones including glucocorticoids have been shown to inhibit the growth of pancreatic cancer cells; however, the prevalence of the glucocorticoid receptor or its mechanism of growth suppression in these tumors is unknown. The ability of growth factors thought to be active in this autocrine loop to reverse the glucocorticoid-induced growth inhibition was studied in vitro in a human pancreatic adenocarcinoma (HPAC) cell line with a well-characterized glucocorticoid receptor (GR). The glucocorticoid dexamethasone (DEX) inhibited growth in a dose-dependent manner as measured by a [3H]thymidine incorporation assay as well as an MTT cell proliferation assay. Maximal effects were seen within 48 hr at a concentration of 100 nM DEX, suppressing growth to approximately 18% of control. When the maximally suppressed DEX-treated cells were exposed to exogenous growth factors, they rapidly attained or exceeded the growth rate of control cells: insulin-like growth factor = 106%, transforming growth factor-alpha = 134%, insulin = 151%, and epidermal growth factor = 187% (all P < 0.05, Student's t test). In order to determine the frequency of the GR in pancreatic cancer and the clinical relevance of our findings, immunohistochemical staining for the GR was performed on 20 human tumors. Twelve (60%) of all cancers, as well as all normal pancreatic tissues (n = 4), stained positively for cytoplasmic and/or nuclear GR with expression correlating highly with degree of tumor differentiation (Kruskal-Wallis test, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Lower efficacy: interaction with an inhibitory receptor or partial agonism?

It is very common in practice to find that some concentration-response curves are 'bell shaped', and this phenomenon also applies to partial agonist curves. On the basis of these considerations, a mathematical model has been developed for the interaction of a ligand with two different receptors that mediate opposite effects (one stimulatory and one inhibitory), and is discussed in this article by Enrico Rovati and Simonetta Nicosia. This model can account for both an apparent reduction in efficacy and the curvature of the upper plateau of some concentration-response curves. Therefore, under certain conditions, an agonist that also interacts with an inhibitory receptor might be mistaken for a partial agonist, unless the concentration-response curves are performed over the widest possible range of concentrations.

Effects of loratadine on cytosolic Ca2+ levels and leukotriene release: novel mechanisms of action independent of the anti-histamine activity

Loratadine, a non-sedating anti-histamine drug, displays in vitro potential anti-allergic properties not related to its interaction with the histamine H1 receptor. In a search for the mechanisms of these actions, we have found that loratadine induces an elevation of cytosolic calcium ion, [Ca2+]i, in rat peritoneal macrophages or human platelets. The mechanism of this elevation resides in the ability of loratadine to discharge intracellular Ca2+ stores, similarly to thapsigargin. This in turn brings about the inhibition of [Ca2+]i rise induced by physiological activators (platelet activating factor and ADP), as well as by thapsigargin. One of the active metabolites of loratadine, descarbo-ethoxy-loratadine, and another anti-histamine, namely terfenadine, exhibit the same effects. In addition, loratadine partially inhibits antigen-induced leukotriene release from human bronchi, but is unable to inhibit the concomitant contraction. We conclude that loratadine can interfere with the mechanisms controlling Ca2+ release, thus inhibiting the cell activation elicited by various agonists through [Ca2+]i elevation. This might be the mechanism underlying its anti-allergic actions in vitro. Furthermore, loratadine might represent an interesting tool in the study of Ca2+ homeostasis.

[Tricuspid insufficiency and pulmonary hypertension in mitral disease: an echocardiographic study]

Tricuspid valve regurgitation and pulmonary hypertension have been evaluated with echo-color-Doppler technique in 100 patients (80 females and 20 males, mean age 54 years) affected by mitral valve stenosis. Pure mitral stenosis was present in 13 patients; 87 had an associated mitral regurgitation. The severity of mitral valve disease was based on the planimetric and functional (Doppler-derived) evaluation of valvular area. No relationship was found between extent of tricuspid regurgitation and severity of mitral valve disease, whereas pulmonary artery hypertension was significantly related to mitral valve involvement, above all Doppler mean gradient (r: 0.63, p < 0.005) and valvular area (r: -0.52, p < 0.01). The study suggests that in patients with mitral valve disease tricuspid regurgitation is independent of the degree of mitral valve involvement, whereas pulmonary hypertension is related to transvalvular gradient and to mitral valve area, but does not depend on the duration of the disease. This is evident only in patients who maintain the sinus rhythm.

Correlation between leukotriene D4-induced contraction and cytosolic calcium elevation: a quantitative and simultaneous evaluation in smooth muscle

The role of Ca++ as an intracellular messenger in leukotriene (LT)D4-induced muscle contraction was investigated by measuring force development and elevation in cytosolic Ca++ concentration simultaneously in strips of guinea pig ileal longitudinal muscle loaded with the fluorescent calcium indicator Fura 2. Upon addition of LTD4, a simultaneous increase in tension and cytosolic calcium concentration, [Ca++]i, was observed. Cumulative applications of LTD4 induced concentration-dependent increases in both muscle tension and [Ca++]i, being the half-maximal effect reached at approximately 6 to 9 nM. A statistically significant positive correlation (r = 0.993, P < .001) exists between the two parameters examined. Removal of calcium in the bathing solution, accompanied by addition of 7.5 mM EGTA, completely prevented any increase in either calcium levels or force development, thus indicating a role for Ca++ influx, rather than a release from intracellular stores. All of the LTD4 antagonists tested were able to counteract the effect of the leukotriene on both [Ca++]i and tension increase. However, although LY171883 shifted both of the LTD4 curves to the right in a parallel fashion, FPL 55712 and ICI 198,615 behaved as non-competitive antagonists in reversing the effect of LTD4 on [Ca++]i and tension. Thus, these results strongly suggest that changes in muscle tension induced by LTD4 are attributable to changes in cytosolic free Ca++ concentrations in guinea pig ileum.

Evaluation of a frozen section protocol in endometrial carcinoma

Between May 1987 and December 1991 sixty four patients with Stage I Endometrial carcinoma were treated primarily with surgery at the University of Colorado Health Sciences Center, Denver and at hospitals in the Tampa Bay Metropolitan region. A frozen section protocol on the hysterectomy specimen was utilized in a uniform manner at all institutes. The aim of the study was to determine the speed and accuracy of this protocol in determining the dominant grade of the tumor and depth of invasion of the myometrium. The accuracy rate for reporting dominant tumor grade when compared to permanent histology was 100% for 33 specimens and 93.6% for the remaining 31 specimens. The overall accuracy for depth of myometrial invasion was expressed as a comparison of the average ratio of myometrial invasion to adjacent uninvolved myometrial thickness between frozen and permanent histology specimens. The correlation was 97.7% in this study. The average time taken was 12.6 minutes for 16 specimens, 18.8 minutes for 33, and 32.4 minutes for 17. A case is made in this paper for the value of such intraoperative information being made available to the surgeon on a routine basis.

The medical legal implications of following mammographic breast masses

Delay in breast cancer diagnosis continues to account for the highest percentage of medical malpractice cases in the United States. A retrospective, computer-aided study was undertaken to investigate a number of parameters used in making medical-legal decisions in missed breast cancer cases. Over a 5-year period, 435 women with invasive breast cancers were registered at the Comprehensive University Breast Cancer Center. A close correlation between mammographic and final histologic size was verified (R = 0.74). In 5-mm increments, starting with a 1.0-mm tumor, there was an increasing percentage of positive nodes identified with increasing size of the tumor. Major percentage increases in frequency of positive nodes were noted at tumor sizes of 11 and 21 mm. This corresponded to an increasing number of recurrences and a decreasing 5-year disease-free survival (DFS) between consecutive 5-mm increments, although the differences were not significant. A multivariate regression analysis confirmed that the most important predictor of DFS was lymph node status (p = 0.0046) and not tumor size. After adjusting for lymph node status, tumor size was not significant. It is concluded that a period of observation, in which a breast cancer may increase in size is not substandard care since tumor size, after accounting for lymph node status is not significant at predicting DFS.