BOLERO-2: Health-related quality-of-life (HRQoL) in metastatic breast cancer patients treated with everolimus and exemestane versus exemestane

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Background: BOLERO-2, a phase III study, randomized 724 patients with hormone-receptor–positive metastatic breast cancer, who had recurrence or progression on/after prior nonsteroidal aromatase inhibitor therapy, to everolimus (EVE) + exemestane (EXE) or EXE + placebo. A preplanned 12-mo median time interim analysis demonstrated that EVE + EXE significantly improved progression-free survival (PFS) vs EXE + placebo, but EVE + EXE resulted in a higher rate of grade 3-4 toxicity. Per-protocol patients reported HRQoL data are limited; here we report on additional post hoc analyses of these outcomes. Methods: Using the EORTC QLQ-C30 questionnaire, HRQoL was assessed at baseline and every 6 weeks thereafter until progression. QLQ-C30 consists of 30 items combined into 15 subscales, including a Global Health Status (GHS), where higher scores (range, 0-100) indicate better HRQoL. Analysis included a protocol-specified time to definitive deterioration (TTD) analysis at a 5% decrease in QoL relative to baseline, with no subsequent increase above this threshold. We report additional sensitivity analyses using 10-point minimally important difference (MID) decreases in QLQ-C30 score relative to baseline. Treatment arms were compared using a stratified log-rank test and a Cox proportional hazards model adjusted for trial stratum (visceral metastases and previous hormone sensitivity), age, sex, race, baseline score, ECOG performance status, prognostic risk factors, and treatment history. Results: Baseline QLQ-C30 GHS scores were not statistically significantly different across treatment groups (64.7 vs 65.3; difference –0.7 [95% CI, –4.3-3.0]). Median TTD in HRQoL was 7.0 mo (95% CI, 5.6-8.3) for EVE + EXE vs 5.6 (95% CI, 4.2-7.0) for EXE (p = .0792). Adjusted HR (0.80) approached significance (95% CI, 0.63-1.02). At the 10-point MID, median TTD for EVE + EXE was 9.7 mo (95% CI, 8.3-11.2) vs 8.4 mo (95% CI, 6.3-12.5) for EXE. Adjusted HR was 0.90 (95% CI, 0.69-1.18). Conclusions: These additional analyses from the BOLERO-2 study demonstrate that in addition to significantly improving PFS, EVE + EXE does not compromise HRQoL.

Everolimus in postmenopausal hormone-receptor-positive advanced breast cancer

BACKGROUND

Resistance to endocrine therapy in breast cancer is associated with activation of the mammalian target of rapamycin (mTOR) intracellular signaling pathway. In early studies, the mTOR inhibitor everolimus added to endocrine therapy showed antitumor activity.

METHODS

In this phase 3, randomized trial, we compared everolimus and exemestane versus exemestane and placebo (randomly assigned in a 2:1 ratio) in 724 patients with hormone-receptor-positive advanced breast cancer who had recurrence or progression while receiving previous therapy with a nonsteroidal aromatase inhibitor in the adjuvant setting or to treat advanced disease (or both). The primary end point was progression-free survival. Secondary end points included survival, response rate, and safety. A preplanned interim analysis was performed by an independent data and safety monitoring committee after 359 progression-free survival events were observed.

RESULTS

Baseline characteristics were well balanced between the two study groups. The median age was 62 years, 56% had visceral involvement, and 84% had hormone-sensitive disease. Previous therapy included letrozole or anastrozole (100%), tamoxifen (48%), fulvestrant (16%), and chemotherapy (68%). The most common grade 3 or 4 adverse events were stomatitis (8% in the everolimus-plus-exemestane group vs. 1% in the placebo-plus-exemestane group), anemia (6% vs. <1%), dyspnea (4% vs. 1%), hyperglycemia (4% vs. <1%), fatigue (4% vs. 1%), and pneumonitis (3% vs. 0%). At the interim analysis, median progression-free survival was 6.9 months with everolimus plus exemestane and 2.8 months with placebo plus exemestane, according to assessments by local investigators (hazard ratio for progression or death, 0.43; 95% confidence interval [CI], 0.35 to 0.54; P<0.001). Median progression-free survival was 10.6 months and 4.1 months, respectively, according to central assessment (hazard ratio, 0.36; 95% CI, 0.27 to 0.47; P<0.001).

CONCLUSIONS

Everolimus combined with an aromatase inhibitor improved progression-free survival in patients with hormone-receptor-positive advanced breast cancer previously treated with nonsteroidal aromatase inhibitors. (Funded by Novartis; BOLERO-2 ClinicalTrials.gov number, NCT00863655.).

Phase I trial to investigate the safety, pharmacokinetics and efficacy of sorafenib combined with docetaxel in patients with advanced refractory solid tumours

AIM

The safety, pharmacokinetics and efficacy of sorafenib plus docetaxel in patients with advanced refractory cancer were investigated in a phase I, dose-escalation trial.

METHODS

Twenty-seven patients in four cohorts received docetaxel on day 1 (cohorts 1 and 4: 75 mg/m2; cohorts 2 and 3: 100 mg/m2) plus sorafenib on days 2-19 (cohorts 1 and 2: 200 mg twice-daily (bid); cohorts 3 and 4: 400 mg bid) in 21-day cycles.

RESULTS

Most common adverse events (AEs) (grade 3-5) included neutropenia (89%), leucopaenia (81%), hand-foot skin reaction (30%) and fatigue (30%). The most common drug-related AEs leading to dose reduction/interruption or permanent discontinuation were dermatologic (41%), gastrointestinal (26%) and constitutional (22%). Coadministration of sorafenib altered the pharmacokinetics of docetaxel. On average, docetaxel area under the concentration-time curve (AUC)(0-24) increased by 5% (cohort 1), 54% (cohort 2), 36% (Cohort 3) and 80% (cohort 4) with docetaxel plus sorafenib, while C(max) increased by 16-32%, independent of sorafenib/docetaxel doses. Three of 25 evaluable patients (11%) had partial responses; 14 (52%) had stable disease.

CONCLUSION

Dose-limiting dermatologic AEs were more common than expected for either therapy alone. A starting dose of docetaxel 75 mg/m2 plus sorafenib 400mg bid (with dose reductions for dermatological toxicities) is proposed for phase II.

AKT1 inhibits homologous recombination by inducing cytoplasmic retention of BRCA1 and RAD51

AKT1 is frequently up-regulated in sporadic breast cancer, whereas BRCA1 is frequently mutated in familial breast cancer. Because BRCA1 is involved in homologous recombination (HR), we addressed whether AKT1 also has an effect on this process. We showed that AKT1 repressed HR through cytoplasmic retention of BRCA1 and RAD51 proteins, resulting in a BRCA1-deficient-like phenotype. This process does not require direct BRCA1 phosphorylation by AKT1. The cytoplasmic retention of BRCA1 and RAD51 correlated with activated AKT1 in tumor cell lines and in biopsies from sporadic breast cancers. Under nonpathologic conditions, fibroblast growth factor, which activates AKT1 and stimulates proliferation in fibroblasts, impaired excessive HR without fully inhibiting it, promoting genome stability. Our study reveals that the regulation of BRCA1 and RAD51 is altered in a high frequency of sporadic breast cancers and highlights the role of extracellular AKT signaling-dependent regulation of HR and genome stability.

Oxaliplatin and 5-fluorouracil in heavily pretreated patients with ovarian carcinoma: A well tolerated and efficient treatment

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Background: Recurrent ovarian cancer is an incurable disease. The prognosis of patients with platinum refractory disease is dismal. We present data from heavily pretreated patients with recurrent ovarian cancer to whom the Folfox regimen was administered. Methods: Patients with recurrent, resistant or refractory, pretreated ovarian carcinoma were eligible for this compassionate use program of oxaliplatin (85 mg/m2 in 2 hours) and leucovorin (200 mg/m2 in 1 hour) on day 1, followed by a continuous infusion of 5FU (2,600 mg/m2 in 48 hours), every 2 weeks. The objectives of the study were primarily to assess response rate and secondarily to evaluate the safety profile. Results: Fourteen patients were treated. Median age: 56 years (49–70). Performance status: 0 (n=4) and 1 (n=10). Median number of previous chemotherapy regimens: 5 (3–10) and previous platinum-based regimens: 2 (1–3). Median chemotherapy-free interval: 9.5 weeks (1–39). Median administered cycles of Folfox/patient: 8 (2–11 cycles). Responses according to RECIST criteria: 2 CR (14.5%), 2 PR (14.5%), 4 SD (29%) and 6 PD (43%). Responses according to CA125 Rustin's criteria: 4 CR (29%), 2 PR (14.5%), 5 SD (35.5%) and 3 PD (21%). Grade 1/2 and 3 peripheral neuropathy: 10 (71%) and 2 (14.5%), respectively. There were no grade 4 adverse events or deaths due to the treatment. Conclusions: Folfox is a valuable option for heavily pre-treated patients with ovarian cancer, with an overall response rate of 29% (95% CI 15.2% to 41.8%), disease stabilization in an additional 29%, and a manageable toxicity profile. These results support the use of Folfox as salvage treatment for patients with ovarian carcinoma.

No significant financial relationships to disclose.

Achievements in systemic therapies in the pregenomic era in metastatic breast cancer

Over the last decades, the introduction of several new agents into clinical practice has significantly improved disease control and obtained some, albeit rare, survival benefits in metastatic breast cancer (MBC). Despite these results, the choice of treatment for the majority of patients is still empirically based, since the only two predictive factors with level 1 evidence for clinical use are hormonal receptor status for endocrine therapy and HER-2 status for trastuzumab therapy. Important improvements in the endocrine therapy of both pre- and postmenopausal women with hormone-responsive disease have been achieved. For premenopausal women, ovarian function suppression with luteinizing hormone-releasing hormone analogs combined with tamoxifen has become the standard treatment, although aromatase inhibitors plus ovarian function suppression are under evaluation. In postmenopausal patients, aromatase inhibitors have proved to be superior to standard endocrine therapies in either first- or second-line treatment and a novel antiestrogen compound, fulvestrant, has been introduced in clinical practice. Chemotherapy remains the treatment of choice for hormone unresponsive or resistant patients. Anthracyclines and taxanes have been used either alone or in combination as first-line chemotherapy, but with the more frequent use of these agents in the adjuvant setting, new standards are needed for first-line chemotherapy, and new and more efficacious treatments are required. In the subgroup of patients with tumors that overexpress HER-2, the use of trastuzumab alone or in combination with chemotherapy has modified the natural history of these tumors, even if only about one out of two patients obtains a clinical response. In this review we summarize the main achievements and the currently available treatment options for patients with MBC.

National survey of molecular epidemiology of Staphylococcus aureus colonization in Belgian cystic fibrosis patients

OBJECTIVES

Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is poorly defined in cystic fibrosis (CF) patients, and S. aureus detection may be hampered by the presence of small colony variants (SCVs). We conducted a multicentre survey to determine the prevalence of S. aureus and MRSA colonization in Belgian CF patients and characterize the phenotype and clonal distribution of their staphylococcal strains.

METHODS

S. aureus isolated from CF patients attending nine CF centres were collected. Oxacillin resistance was detected by oxacillin agar screen and mecA PCR. Antibiotic susceptibility was tested by microdilution. MRSA strains were genotyped by PFGE and SCCmec typing and compared with hospital-associated MRSA strains.

RESULTS

Laboratories used a diversity of sputum culture procedures, many of which appeared substandard. S. aureus was isolated from 275/627 (44%) CF patients (20% to 72% by centre). The prevalence of SCV colonization was 4%, but SCVs were almost exclusively recovered from patients in two centres performing an SCV search. Phenotypically, 14% of S. aureus isolates were oxacillin-resistant: 79% carried mecA and 19% were SCVs lacking mecA. The mean prevalence of 'true' MRSA colonization was 5% (0% to 17% by centre). By PFGE typing, 67% of CF-associated MRSA were related to five epidemic clones widespread in Belgian hospitals.

CONCLUSIONS

This first survey of S. aureus colonization in the Belgian CF population indicated a diversity in local prevalence rates and in proportion of oxacillin-resistant and SCV phenotypes, probably related to variation in bacteriological methods. These findings underscore the need for standard S. aureus detection methods and MRSA control policies in Belgian CF centres.

Appendicitis in pregnancy: a case report and a review of the current literature

Acute appendicitis is the most common surgical problem in pregnancy. Antibiotic treatment does not always improve the outcome and emergency intervention is required. We present a case of appendicitis complicated by a plastron formation occurring during pregnancy and the outcome.

Monoclonal antibody-based targeted therapy in breast cancer: current status and future directions

The recent development of monoclonal antibodies targeting growth factor receptors in cancer treatment represents a milestone for both researchers and physicians. Advances in the understanding of key molecular pathways for tumour growth and survival have facilitated the development of these targeted therapies, in particular in breast cancer. This review focuses on the three most important recombinant humanised monoclonal antibodies that have shown activity in women with breast cancer: trastuzumab, pertuzumab and bevacizumab. Trastuzumab, an anti-erbB2 (human epidermal growth factor receptor) monoclonal antibody, is currently routinely used in both the metastatic and adjuvant settings for patients with erbB2-positive tumours. Pertuzumab, a monoclonal antibody binding to a different epitope on erbB2 than trastuzumab, is under early clinical evaluation. This drug has been developed for breast cancer patients, whether overexpressing erbB2 or not. Bevacizumab, a monoclonal antibody directed against vascular endothelial growth factor-A, is being evaluated in the metastatic setting for its antiangiogenic properties, and is showing promising results.

[Arterial duplex and aortic valve stenosis: sensitivity and specificity of findings]

Purposes. In this prospective study, we sought to determine the sensitivity and the specificity of arterial Doppler findings of valvular aortic stenosis (VAS).

PATIENTS AND METHODS

20 control subjects and 20 patients with various degrees of VAS underwent Doppler ultrasound of the carotids, abdominal aorta, renal arteries and limb arteries. We analyzed and compared the shape of the spectral profiles, peak systolic velocity (PSV), systolic upstroke time (SUT) and systolic upstroke index (SUI) of every tracing. The protodiastolic notch (PDN) of the common femoral arteries were recorded too.

RESULTS

VAS hardly modifies the overall shape of the Doppler spectrums of the aorta or limb arteries but it implies a biphasic deformation or a doubling of the systolic peak of the neck vessels. We also encountered biphasic profiles in renal arteries of patients with tight VAS. The PSV, SUI and depth of the PDN tend to diminish in cases of VAS but the variations are inconstant and rarely proportional to the severity of the narrowing. The increase of the SUT, on the contrary, is linearly correlated to the severity of the stenosis in every arterial system: SUTs in the common carotid artery, internal carotid artery or brachial artery that are shorter than or equal to 70 milliseconds (msec) are the obvious marks of the absence of VAS. It was not possible to differentiate between the intermediate stenoses (aortic valve area between 0.8 and 2 square centimeters) whereas critical aortic stenoses, whose area is less than or equal to 0.7 square centimeter, can be detected by the presence of at least two of the four following criteria of SUT: equal to or above 180 msec for the common carotid, 200 msec for the internal carotid, 130 msec for the aorta and 110 msec for the common femoral artery.

CONCLUSION

During routine arterial Doppler ultrasound, a precise analysis of the spectrums and some SUT measurements allow the assessment of the aortic valve.

Bax and Bid, two proapoptotic Bcl-2 family members, inhibit homologous recombination, independently of apoptosis regulation

In order to analyse the relationships between regulation of apoptosis and homologous recombination (HR), we overexpressed proapoptotic Bax or only-BH3 Bid proteins or antiapoptotic Bcl-2 or Bcl-XL, in hamster CHO cells or in SV40-transformed human fibroblasts. We measured HR induced by gamma-rays, UVC or a specific double-strand cleavage targeted in the recombination substrate by the meganuclease I-SceI. We show here that the induction of both recombinant cells and recombinant colonies was impaired when expressing Bcl-2 family members, in hamster as well as in human cells. Moreover, the pro- as well as antiapoptotic Bcl-2 family members inhibited HR, independently of degradation of the RAD51 recombination protein and of their impact on apoptosis. These data reveal a mechanism of HR downregulation by potentially proapoptotic proteins, distinct from and parallel to degradation of recombination proteins, a situation that should also optimize the efficiency of programmed cell death.

Adjuvant chemotherapy in 2005: Standards and beyond

The 2003 St. Gallen consensus panel divided the many available adjuvant chemotherapy (CT) regimens into those with "standard efficacy" (ACx4, CMFx6) and those with "superior efficacy" (FA(E)Cx6, CA(E)Fx6, A(E)-->CMF, TACx6, ACx4--> paclitaxel (P)x4 or docetaxel (D)x4) but also greater complexity, toxicity and cost. This paper will summarize the latest information on long-term side effects of the "superior" regimens and 5-year benefits reported in taxane trials, including those of a "new" sequential regimen, FECx3--> docetaxelx3. Rapidly expanding evidence of marked heterogeneity in the magnitude of CT benefits according to the tumour oestrogen receptor (ER) status, a claim made for many years by IBCSG investigators, will be reviewed; it will lead to the conclusion that a revolution needs to take place in the way oncologists think about the CT added value and design adjuvant clinical trials. The conclusions proposed to the 2005 St. Gallen consensus panel are that: adequately dosed anthracycline-based CT regimens remain an acceptable standard for many women; a lower threshold for using taxanes in sequence or combination with anthracyclines (A) is justified in the presence of an ER-negative or low-ER tumour status, other aggressive biologic features (such as HER-2 overexpression), fear about A-induced cardiotoxicity; no recommendation can yet be made as far as the optimal taxane-A regimen, the best taxane or the best taxane schedule.

Maintenance of differentiation capacity of HT-29 cells after radiation exposure

PURPOSE

Following ionizing radiation exposure, intestinal crypt regeneration is possible but it is still not known if regenerating crypts give rise to differentiated functional epithelial cells on villi. The aim of this study was to demonstrate that irradiated progeny of enterocytic precursor cells are capable of proliferation and subsequent differentiation using the HT-29?cell line.

MATERIALS AND METHODS

Cells were cultured, irradiated (5 Gy or 10 Gy) and incubated in the presence or absence of butyrate (5 mM). Cell numbers, cell cycle parameters, alkaline phosphatase (ALP) activity, occludin labelling and gene expression were determined at different times post-exposure.

RESULTS

Butyrate-induced inhibition of cell growth and arrest in G0 phase was comparable in both sham and irradiated cells in addition to similar development of ALP activity and expression. Cells also formed a monolayer with tight junctions post-irradiation. Butyrate-stimulated modulation of integrin expression during differentiation was unchanged after radiation exposure. Genes known to be implicated in differentiation mechanisms, i.e., growth and transcription factors (vascular Epidermal Growth Factor, v-EGF ; Activating Transcription Factor 4, ATF4), cell cycle genes (Cyclin-Dependent Kinase Inhibitor 1A, CDKN1A/p21(Cip1/waf1)), were studied. Most responded similarly to the differentiation stimulus whether irradiated or not.

CONCLUSION

These results demonstrate that irradiated HT-29 cells still respond to butyrate to form a differentiated, functional epithelium.

Functional and structural alterations of epithelial barrier properties of rat ileum following X-irradiation

Irradiation of the digestive system leads to alterations of the small intestine. We have characterized the disruption of the barrier integrity in rat ileum from 1 to 14 days following irradiation ranging from 6 to 12 Gy. The intestinal permeability to 14C-mannitol and 3H-dextran 70 000 was measured in vitro in Ussing chambers. In parallel to these functional studies, immunohistochemical analyses of junctional proteins (ZO-1 and beta-catenin) of ileal epithelium were performed by confocal microscopy. Irradiation with 10 Gy induced a marked decrease in epithelial tissue resistance at three days and a fivefold increase in mannitol permeability, without modifications of dextran permeability. A disorganization of the localization for ZO-1 and beta-catenin was also observed. At 7 days after irradiation, we observed a recovery of the organization of junctional proteins in parallel to a return of intestinal permeability to control value. In addition to these time-dependent effects, a gradual effect on epithelial integrity of the radiation doses was observed 3 days after irradiation. This study shows a disruption of the integrity of the intestinal barrier in rat ileum following abdominal X-irradiation, depending on the time postirradiation and on the delivered dose. The loss of barrier integrity was characterized by a disorganization of proteins of tight and adherent junctions, leading to increased intestinal permeability to mannitol.

[Amaurosis fugax of cardiac origin]

We present the case of a 49 year old woman who was admitted to the emergency department for dyspnoea, transient amaurosis and limbs oedema. During hospitalisation a full workup revealed multisystemic thrombosis and dilated cardiomyopathy in relation with viral myocarditis due to Coxackie B infection. Diagnosis and treatment will be discussed in light of the litterature.

Compact sources as the origin of the soft γ-ray emission of the Milky Way

The Milky Way is known to be an abundant source of gamma-ray photons, now determined to be mainly diffuse in nature and resulting from interstellar processes. In the soft gamma-ray domain, point sources are expected to dominate, but the lack of sensitive high-resolution observations did not allow for a clear estimate of the contribution from such sources. Even the best imaging experiment revealed only a few point sources, accounting for about 50% of the total Galactic flux. Theoretical studies were unable to explain the remaining intense diffuse emission. Investigating the origin of the soft gamma-rays is therefore necessary to determine the dominant particle acceleration processes and to gain insights into the physical and chemical equilibrium of the interstellar medium. Here we report observations in the soft gamma-ray domain that reveal numerous compact sources. We show that these sources account for the entirety of the Milky Way's emission in soft gamma-rays, leaving at most a minor role for diffuse processes.

Influence of peroperative opioid on postoperative pain after major abdominal surgery: sufentanil TCI versus remifentanil TCI. A randomized, controlled study

BACKGROUND

Sufentanil and remifentanil are characterized by two different pharmacokinetic profiles. The aim of this study was to compare the effects of sufentanil and remifentanil administered using target-controlled infusion (TCI) on recovery and postoperative analgesia after major abdominal surgery.

METHODS

Thirty adult patients scheduled for open colorectal surgery were included in a prospective, randomized study. Sufentanil TCI (sufentanil group) or remifentanil TCI (remifentanil group) was administered during surgery. In the remifentanil group, 30 min before the anticipated end of surgery, morphine 0.15 mg x kg(-1) was administered i.v. In the sufentanil group, an effect-site concentration of 0.25 ng x ml(-1) was targeted at extubation. In both groups, postoperative pain was controlled by titration of i.v. morphine and then patient-controlled analgesia with morphine.

RESULTS

The extubation time was similar in the two groups (mean (SD) 13 (6) and 14 (6) min in the sufentanil and remifentanil groups respectively). Visual analogue scale scores were significantly greater during the first 2 h after tracheal extubation in the remifentanil group than in the sufentanil group. The time to first analgesic request in the postanaesthesia care unit was significantly longer in the sufentanil group than in the remifentanil group (55 (64) (range 2-240) vs 11 (7) (1-29) min; P<0.001). The cumulative morphine dose for titration was significantly greater in the remifentanil group (P<0.01). The cumulative morphine dose used during titration and patient-controlled analgesia was significantly greater in the remifentanil group 4, 12 and 24 h after extubation (P<0.05).

CONCLUSION

TCI sufentanil (0.25 ng ml(-1) effect-site concentration at extubation) is more effective than the intraoperative combination of remifentanil TCI infusion with morphine bolus (0.15 mg x kg(-1)) for postoperative pain relief after major abdominal surgery and does not compromise extubation and recovery.

Potential role of the membrane in the development of intestinal cellular damage after whole-body gamma irradiation of the rat

Our study emphasizes the effect of gamma irradiation on intestinal cell membrane fluidity and addresses the potential relationships existing between radiation-induced lipoperoxidation, membrane fluidity, and changes in membrane protein activities. Male Wistar rats were exposed to an 8-Gy total body irradiation (60Co source) and studied 1, 4, and 7 days after irradiation (D1, D4, and D7). Membrane enzyme activities and fluorescence anisotropy were determined on small intestinal crude membrane preparations. The supernatants of membrane preparations as well as plasma were used for malonedialdehyde (MDA) quantification. The effect of carbamylcholine on electrical parameters was estimated on distal ileum placed in Ussing chambers. We observed a decrease in fluorescence anisotropy for at least 7 days, an increase in membrane production of MDA at D4, a decrease in membrane enzyme activities at D4, but an amplification of carbamylcholine-induced increase in short-circuit current at D4 and D7. Furthermore, correlations were observed between the 1,6-diphenyl-1,3,5-hexatriene anisotropy coefficient and sucrase activity and between MDA levels and leucine aminopeptidase activity. Thus, total body irradiation induces changes in intestinal membrane fluidity and an increase in lipoperoxidation. These modifications may have an impact on the activity of membrane proteins involved in intestinal function.

Alterations of the VIP-stimulated cAMP pathway in rat distal colon after abdominal irradiation

Ionizing radiation induces hyporesponsiveness of rat colonic mucosa to vasoactive intestinal peptide (VIP). Possible mechanisms responsible for this hyporesponsiveness of the cAMP communication pathway in rat colon were investigated. VIP- and forskolin-stimulated short-circuit current (I(sc)) responses were studied after a 10-Gy abdominal irradiation in Ussing chambers as well as in single, isolated crypts. Adenylyl cyclase (AC) activity and VIP receptor characteristics were determined in mucosal membrane preparations. In addition, alterations in crypt morphology were studied. Impaired secretory responses to VIP and forskolin were observed 4 days after irradiation (decrease of 80%). cAMP analog-stimulated I(sc) responses were unchanged. In isolated crypts, VIP- and forskolin-stimulated cAMP accumulation was markedly reduced by 80 and 50%, respectively. VIP-stimulated AC activity and VIP receptor number were decreased in membrane preparations. No major change of cellularity was associated with these functional alterations. In conclusion, the decreased secretory responses to VIP of rat colon are associated with reduced cAMP accumulation, decreased AC activity, and diminution of VIP receptor numbers without a marked decrease of crypt cell number.

Quantitation of functional mitral regurgitation during bicycle exercise in patients with heart failure

OBJECTIVES

We sought to examine the feasibility and reliability of quantifying mitral regurgitation (MR) during exercise by Doppler echocardiography in patients with heart failure and to assess the relationship between dynamic MR and systolic pulmonary artery pressure changes.

BACKGROUND

The severity of MR can be quantified by using several echocardiographic methods. Quantitation of MR during dynamic exercise has not yet been performed.

METHODS

Symptom-limited, semi-supine two-dimensional and Doppler echocardiograms during bicycle exercise were obtained in 27 consecutive patients with heart failure and functional MR. Regurgitant volume was measured at rest and during exercise by the proximal isovelocity surface area (PISA) method and by quantitative Doppler echocardiography. Exercise-induced changes in regurgitant volume were compared with changes in the regurgitant jet area to left atrial area ratio, vena contracta width and trans-tricuspid pressure gradient.

RESULTS

The regurgitant volume measured by the PISA method increased from 21 +/- 12 ml (range 5 to 55) at rest to 39 +/- 23 ml (range 8 to 85) during exercise (p < 0.0001). The difference between two observers was low for both rest (2.0 +/- 2.7 ml) and exercise measurements (3.5 +/- 6.2 ml). The regurgitant volume measured by quantitative Doppler echocardiography increased from 29 +/- 13 to 49 +/- 24 ml (p = 0.0001). Excellent correlation between the two methods was obtained with exercise (r = 0.92). Exercise-induced changes in regurgitant volume, as measured by the PISA method, correlated well with regurgitant volume changes measured by quantitative Doppler echocardiography (r = 0.88), changes in vena contracta width (r = 0.82) and changes in trans-tricuspid pressure gradient (r = 0.73), but not with changes in regurgitant jet area to left atrial area ratio (r = 0.29). Seventeen patients stopped exercise because of fatigue and 10 because of dyspnea. These 10 patients exhibited greater increases in regurgitant volume (34 +/- 6 vs. 11 +/- 8 ml), corresponding to a significant elevation of the trans-tricuspid gradient (48 +/- 14 vs. 20 +/- 14 mm Hg).

CONCLUSIONS

Quantitation of functional MR during exercise is feasible in patients with heart failure. There is a good correlation between regurgitant volume measured during exercise by the PISA method and that obtained by quantitative Doppler echocardiography, suggesting that the technique is reliable. An increase in mitral regurgitant volume during dynamic exercise correlates well with elevation of systolic pulmonary artery pressure.