Evidence for a role of autoinflammation in early-phase psoriasis.

Psoriasis is a common, inflammatory immune-mediated skin disease mainly presenting with plaques whose pathogenesis is based on the central role of the interleukin (IL)-23/IL-17 axis. However, the mechanisms acting in papular lesions of early-phase psoriasis are not fully understood. The aim of this study was to assess the involvement of autoinflammation, a state of sterile inflammation mainly driven by IL-1 over-production that has been recently hypothesized to act in the early phase of disease. Lesional skin of 10 patients with recent onset, untreated psoriasis has been investigated for expression of IL-1ß, IL-17, IL-23 and other cytokines involved in the disease in comparison with normal skin of 10 healthy controls using a protein array method. Immunohistochemical phenotyping of inflammatory infiltrate and co-localization experiments with immunofluorescence confocal microscopy were conducted. IL-1ß was significantly more expressed in psoriasis than in normal skin (P < 0·0001). The chemokine IL-8 was also over-expressed in psoriasis (P = 0·03) while IL-12, IL-17, IL-23, tumour necrosis factor-α and interferon-γ were only slightly more expressed in psoriasis than in normal skin, without reaching statistical significance. The inflammatory infiltrate consisted mainly of neutrophils with a relevant number of macrophages and dendritic cells and only scattered, predominantly T helper 1 lymphocytes. IL-1ß co-localized mainly with CD66b, a neutrophil marker, suggesting that neutrophils were the major source of this cytokine. IL-1ß over-expression in combination with low expression of cytokines that are predominant in late-phase plaque psoriasis may support the role of autoinflammation in early-phase disease, possibly paving the way to randomized trials with IL-1 antagonists.

'Indeterminate for malignancy' (Tir3/Thy3 in the Italian and British systems for classification) thyroid fine needle aspiration (FNA) cytology reporting: morphological criteria and clinical impact.

BACKGROUND: The British system (Thy1-5), the Bethesda system for reporting thyroid cytopathology (BSRTC) and the Italian Society of Anatomic Pathology and Cytology (SIAPEC) classification represent the most important international classifications for thyroid cytopathology. Irrespective of the system used, the 'indeterminate' categories are still debated among cytopathologists, particularly with regard to diagnostic criteria, clinical impact of subclassification and role of molecular techniques. AIM: We aimed to find answers to the following questions: Are there shared criteria in cytological preparations that allow the division of indeterminate follicular lesions into subcategories? What is the true clinical impact of this possible subclassification? METHODS: Among 1150 consecutive thyroid fine needle aspiration (FNA) specimens, 80 patients had nodules with a final cytological report of Tir3 (SIAPEC)/Thy3. These 80 cases were re-evaluated and subclassified according to morphological criteria into three groups: pure follicular proliferations, Hürthle cell follicular lesions and atypical proliferations. RESULTS: Sixteen (20%) cases were categorized as pure follicular proliferations, 40 (50%) as Hürthle cell follicular lesions and 24 (30%) as atypical proliferations. Surgery was performed in 57 cases (71%). Cyto-histological correlation showed that follicular adenoma was the most frequent final diagnosis in the cases treated by surgery (24/57, 42%). The overall malignancy rate in the Tir3 category was 28% (16/57). Atypical proliferations were more often malignant than either of the follicular groups (53% versus 19%, P = 0.019). CONCLUSIONS: A five-tiered classification, subdividing the 'indeterminate for malignancy' class into 'follicular proliferations' and 'atypical lesions' could be adopted. As a result of their higher risk of malignancy, surgical management of the atypical lesions would be justified. In future, the introduction of a genetic panel might contribute to their stratification, to the determination of a more accurate risk of malignancy of the atypical lesions and to the verification of follicular proliferations that are benign.

K-ras and p53 gene mutations in pancreatic cancer: ductal and nonductal tumors progress through different genetic lesions.

We studied K-ras and p53 gene mutations in a panel of 57 primary pancreatic cancers including ductal and nonductal tumors. DNAs were obtained from formalin-fixed, paraffin-embedded material. Target sequences were amplified by polymerase chain reaction and analyzed by denaturing gradient gel electrophoresis and sequencing. Both K-ras and p53 genes were frequently mutated in ductal cancers (25 of 35, 71.4%; 18 of 35, 51.4%, respectively). K-ras mutations were confined to the second position of codon 12 where base transitions and transversions were equally observed. p53 changes were mainly missense mutations. Transitions and transversions were found equally with a prevalence of G:C-->A:T changes among transitions. No gene alterations were present in the 6 exocrine nonductal tumors and (with one exception) in the 12 endocrine tumors analyzed. Our results indicate that mutated K-ras and p53 genes can cooperate in the establishment of ductal pancreatic cancers, whereas other genetic events have to be present in nonductal tumors. Moreover, K-ras alterations may represent an early event in ductal tumorigenesis, as suggested both by the high gene mutation frequency and by the presence of mutations in low-grade tumors. On the contrary, p53 gene changes seem to represent an event required for the malignancy progression of ductal tumors from lower to higher grades.

A novel oncogenic BTK isoform is overexpressed in colon cancers and required for RAS-mediated transformation.

Bruton's tyrosine kinase (BTK) is essential for B-cell proliferation/differentiation and it is generally believed that its expression and function are limited to bone marrow-derived cells. Here, we report the identification and characterization of p65BTK, a novel isoform abundantly expressed in colon carcinoma cell lines and tumour tissue samples. p65BTK protein is expressed, through heterogeneous nuclear ribonucleoprotein K (hnRNPK)-dependent and internal ribosome entry site-driven translation, from a transcript containing an alternative first exon in the 5'-untranslated region, and is post-transcriptionally regulated, via hnRNPK, by the mitogen-activated protein kinase (MAPK) pathway. p65BTK is endowed with strong transforming activity that depends on active signal-regulated protein kinases-1/2 (ERK1/2) and its inhibition abolishes RAS transforming activity. Accordingly, p65BTK overexpression in colon cancer tissues correlates with ERK1/2 activation. Moreover, p65BTK inhibition affects growth and survival of colon cancer cells. Our data reveal that BTK, via p65BTK expression, is a novel and powerful oncogene acting downstream of the RAS/MAPK pathway and suggest that its targeting may be a promising therapeutic approach.

Sequential therapy with methotrexate and 5-fluorouracil in the treatment of advanced colorectal carcinoma.

Twenty-nine patients with advanced colorectal carcinoma were entered in this study to evaluate the efficacy and toxicity of a sequential chemotherapeutic schedule with methotrexate (MTX), 200 mg/m2 intravenously (IV) (push injection) and 5-fluorouracil (5-FU), 1,200 mg/m2 in continuous IV infusion, using a 20-hour time interval. All patients received calcium leucovorin (LV), 25 mg, intramuscularly (IM) every six hours for eight doses beginning 24 hours after methotrexate administration. Courses were administered every 15 days. Of the 24 patients evaluable for response, 11 (46%) had major objective regressions (one complete remission [CR] and ten partial remissions [PR]). The survival rate of patients who responded to treatment was 60% at 16 months, whereas patients with no change and those in whom the disease progressed had a median survival of 9 months and 3 months, respectively. The median duration of response has not yet been reached in patients who presented objective tumor regression, and was 7.5 months in those with no change. Significant differences were found between objective regression and no change (P less than .0005) and between no change and tumor progression (P less than .05). All patients were evaluable for toxicity. There were three toxic-related deaths (10%) because of severe myelosuppresion, sepsis, and hemorrhage. These promising results, despite important toxicity, reveal the synergism between the two chemotherapeutic agents and also indicate that the response rate achieved could be a consequence of the 20-hour interval and high dose of 5-FU. Further studies are necessary to determine the optimal time interval and the adequate 5-FU dose.

Carboplatin plus ifosfamide as salvage treatment of epithelial ovarian cancer: a pilot study.

PURPOSE: This study aimed to evaluate the activity and toxicity of carboplatin (PPL) and ifosfamide (IFO) in patients with epithelial ovarian cancer previously treated with cisplatin (CDDP)-containing regimens. PATIENTS AND METHODS: From July 1989 to December 1991, 35 patients with epithelial ovarian cancer relapsed or refractory to CDDP as first-line chemotherapy were treated. PPL was administered at a dose of 300 mg/m2 intravenously (IV) on day 1 and IFO at a dose of 1,500 mg/m2 IV on days 1 to 3 every 3 to 4 weeks. Criteria for evaluating previous response to CDDP were strictly defined. RESULTS: The overall response rate was 43% (complete response [CR], 6%; partial response [PR], 37%) and the median duration of response was 7 months (range, 3 to 16). In potentially platinum-sensitive (PPS; relapsed) patients, the overall response rate was 56%. None of the primary platinum-resistant (PPR) patients obtained a clinical response to PPL plus IFO, whereas one of five secondary platinum-resistant (SPR) patients obtained a PR. The regimen was easily manageable. CONCLUSION: PPL plus IFO is useful and well-tolerated combination in salvage treatment of patients with advanced ovarian cancer. However, clear synergism between PPL and IFO that could overcome intrinsic or acquired CDDP resistance was not observed. The advantage of PPL plus IFO as compared with CDDP-containing regimens is represented by the increased tolerability and the reduced neurotoxicity, nephrotoxicity, and ototoxicity as compared with CDDP-containing regimens. It is essential that the patient population be defined according to their previous response to platinum therapy in trials involving second-line therapy of ovarian cancer.

Ifosfamide and mitoxantrone as first-line chemotherapy for metastatic breast cancer.

PURPOSE: A phase II trial was performed to evaluate the efficacy and toxicity of a combination of ifosfamide (IFX) and mitoxantrone (MXN) as first-line chemotherapy for metastatic breast carcinoma. PATIENTS AND METHODS: Between January 1990 and August 1991, 48 patients with metastatic breast cancer were entered onto the study. Therapy consisted of IFX 2 g/m2 given as a 1-hour intravenous (IV) infusion on days 1 to 3; mesna 400 mg/m2 as an IV bolus immediately before and 4 hours after IFX administration and 2,000 mg orally 8 hours after IFX administration on days 1 to 3; and MXN 12 mg/m2 as an i.v. bolus on day 3. Cycles were repeated every 21 days until progressive disease (PD) or severe toxicity developed. RESULTS: One patient was considered not assessable for response. Objective regression (OR) was observed in 28 of 47 patients (60%; 95% confidence interval, 46% to 74%). Six patients (13%) had a complete response (CR) and 22 (47%) had a partial response (PR). The median time to treatment failure for the whole group was 9 months (range, 1 to 28); median survival was 19 months (range, 2 to 28). There were no treatment-related deaths. The limiting toxicity was myelosuppression. Leukopenia occurred in 37 patients (77%) and was grade 3 or 4 in 19 patients (40%). Nausea and vomiting were observed in 38 patients (80%), mucositis in 16 patients (33%), and grade 2 hematuria in two patients (4%). Eight patients (16%) developed mild neurotoxicity. CONCLUSION: The combination of IFX plus MXN is an active regimen against metastatic breast cancer with moderate toxicity that deserves further evaluation.

Revertant and potentiating activity of lonidamine in patients with ovarian cancer previously treated with platinum.

PURPOSE: Lonidamine (LND) is an energolytic derivative of indazol-carboxylic acid that has been shown to enhance cisplatin (CDDP) activity in both sensitive (A2780) and resistant (A2780/Cp8) ovarian cancer cell lines. The aim of this study was to confirm the potentiating or reverting activity of LND on CDDP activity obtained in experimental models in a phase II study of advanced ovarian cancer patients previously treated with platinum-based regimens. PATIENTS AND METHODS: Twenty-seven consecutive women with histologically proven and measurable ovarian cancer previously treated with platinum compounds were treated with CDDP plus LND. CDDP was administered at 1 mg/kg intravenously (IV) once weekly for 6 weeks and every 3 weeks thereafter until disease progression or toxicity. LND was administered at 450 mg daily (1 tablet every 8 hours) for the entire period of therapy starting 3 days before the first CDDP administration. In addition, a higher LND dosage was provided on the day of CDDP administration in an attempt to maximize the synergy of this drug with CDDP. RESULTS: Ten patients achieved a complete response (CR) or partial response (PR) for an overall response rate of 37% (95% confidence interval [CI], 19% to 55%). In particular, responses were observed in five of 18 (28%) refractory or early relapsed patients (one CR and four PRs) and in five of nine patients (55%) in the late-relapsed group (two CRs and three PRs). Grade 3 or 4 anemia, leukopenia, and thrombocytopenia were observed in 19%, 15%, and 11% of patients, respectively, whereas seven of 27 patients (26%) showed LND-related myalgia. Grade 3 renal toxicity was observed in two patients (8%). Neurotoxicity, often concealed by LND-related myalgia, was recorded as grade 1 or 2 in six patients (22%) and as grade 3 in one (4%). CONCLUSION: The 37% response rate observed in this study (28% in refractory or early-relapsed patients), suggests that the synergism between CDDP and LND observed in vitro against ovarian cancer cell lines can be clinically confirmed. However, larger series and randomized studies are needed to assess definitely the revertant activity of LND on CDDP-refractory patients.

Vinorelbine and paclitaxel as first-line chemotherapy in metastatic breast cancer.

PURPOSE: To evaluate the efficacy and toxicity of a combination of vinorelbine (VNB) and paclitaxel (PTX) as first-line chemotherapy in metastatic breast carcinoma (MBC). PATIENTS AND METHODS: Between August 1995 and August 1997, 49 patients with untreated MBC received a regimen that consisted of VNB 30 mg/m2 in a 20-minute intravenous (IV) infusion on days 1 and 8 and PTX 135 mg/m2 in a 3-hour IV infusion (starting 1 hour after VNB) on day 1. Cycles were repeated every 28 days. The median age of the patients was 52 years, and 59% of patients were postmenopausal. Median performance status was 1. Dominant sites of disease were soft tissue in 6%, bone in 29%, and viscera in 65%. RESULTS: Objective responses were recorded in 27 of 45 assessable patients (60%; 95% confidence interval, 46% to 74%). Complete remissions occurred in three patients (7%), and partial remissions occurred in 24 patients (53%). No change was recorded in 12 patients (27%), and progressive disease occurred in six patients (13%). The median time to treatment failure was 7 months, and median survival duration was 17 months. The limiting toxicity was myelosuppression, mainly leukopenia in 49 patients (100%) (grade 1 to grade 2, four patients; grade 3, 30 patients; and grade 4, 15 patients). Neutropenia was observed in 100% of patients (grade 1 to grade 2, three patients; grade 3, 11 patients; grade 4, 35 patients). Two treatment-related deaths due to febrile neutropenia were observed in patients with massive liver involvement. Peripheral neurotoxicity developed in 33 patients (67%) (grade 1, 25 patients; grade 2, eight patients); there were no grade 3 or grade 4 episodes. CONCLUSION: The combination of VNB-PTX showed significant activity as first-line chemotherapy for patients with MBC. Myelosuppression was the dose-limiting side effect, whereas neurotoxicity was mild to moderate.

Vinorelbine as neoadjuvant chemotherapy in advanced cervical carcinoma.

PURPOSE: To evaluate the efficacy and toxicity of vinorelbine (VNB) as single-agent neoadjuvant chemotherapy in advanced cervical carcinoma (ACC). PATIENTS AND METHODS: Between December 1993 and October 1995, 43 untreated patients with stages IIB to IVA squamous cell cervical cancer were entered onto this study. Forty-two patients are assessable for response and 43 for toxicity. The median age was 46 years (range, 28 to 65). Distribution by stages (International Federation of Gynecology and Obstetrics [FIGO]) was as follows: IIB, 18 patients; IIIA, one; IIIB, 19; and IVA, five. Therapy consisted of VNB 30 mg/m2 by 20-minute intravenous (IV) infusion repeated weekly for 12 injections and followed by radical surgery if feasible or definitive radiotherapy. Both staging and response assessment were performed by a multidisciplinary team. RESULTS: One patient was considered not assessable for response. A total of 493 cycles of therapy were administered and objective remissions were observed in 19 of 42 patients (45%; 95% confidence interval, 30% to 60%). Two patients (5%) had a complete response (CR) and 17 (40%) a partial response (PR); no change (NC) was observed in 16 (38%) and progressive disease (PD) in seven (17%). Six of 19 patients (32%) who achieved objective responses (ORs) underwent surgery. The median time to failure and median survival time have not been reached yet. There were no therapy-related deaths. The dose-limiting toxicity was myelosuppression. Leukopenia occurred in 35 patients (81%) and was grade 3 or 4 in seven (17%). Twelve patients (28%) developed peripheral neuropathy, while myalgias occurred in 10 (23%). Constipation was observed in nine patients (21%), one with a prolonged ileum. Phlebitis was recorded in 18 patients (41%). In contrast, emesis and mucositis were rarely observed. No patient developed alopecia grade 3. By the end of the twelfth course of treatment, the average received dose-intensity was 85.4% of that projected. CONCLUSION: VNB is an active drug against ACC with moderate toxicity. Its activity is among the highest reported for single agents. Further evaluation in association with other agents is clearly justified.

Ifosfamide and vinorelbine as first-line chemotherapy for metastatic breast cancer.

PURPOSE: To evaluate the efficacy and toxicity of the combination of ifosfamide (IFX) and vinorelbine (VNB) as first-line chemotherapy in metastatic breast cancer (MBC). PATIENTS AND METHODS: Between August 1993 and August 1995, 45 patients with untreated MBC received a regimen that consisted of IFX 2 g/m2 by 1-hour intravenous (i.v.) infusion on days 1 to 3, mesna 400 mg/m2 by i.v. bolus at hours 0 and 4 and 800 mg/m2 orally at hour 8 on days 1 to 3, and VNB 35 mg/m2 by 20-minute i.v. infusion on days 1 and 15. Courses were repeated every 28 days. During the first course only, half-dose VNB (17.5 mg/m2) was administered on days 8 and 22. The median age was 53 years and 30 patients (67%) were postmenopausal. Dominant sites of disease were soft tissue in nine patients, bone in seven, and visceral in 29. RESULTS: Objective responses (ORs) were recorded in 25 of 43 assessable patients (58%; 95% confidence interval, 43% to 73%). Complete remissions (CRs) occurred in six patients (14%) and partial remissions (PRs) in 19 (44%). No change (NC) was recorded in 10 patients (23%) and progressive disease (PD) in eight patients (19%). The median time to treatment failure was 12 months and the median survival duration 19 months. Myelosuppression was the limiting toxicity, mainly leukopenia in 32 patients (74%). In contrast, anemia and thrombocytopenia were mild. Other significant toxicities included peripheral neuropathy in nine patients (21%), constipation in 15 (35%), and myalgias in 11 (26%). CONCLUSION: IFX/VNB is an active combination against MBC with moderate toxicity and deserves further evaluation.

Pressure-length loop area: its components analyzed during graded myocardial ischemia.

The changes in total pressure-length loop area were compared with changes in effective shortening area, systolic lengthening area and postsystolic shortening area (defined with respect to end-diastolic and end-systolic lengths) of the pressure-length loop during myocardial ischemia in seven anesthetized dogs instrumented for measurement of left ventricular pressure and regional segmental wall motion (sonomicrometry) in the minor axis of the apical region of the left ventricle. Ischemia was induced by gradual tightening of a micrometer-controlled snare around the left anterior descending coronary artery, which supplied the apical myocardium. Data were obtained at normal flow, after critical constriction (loss of pulsatile coronary flow), mild ischemia (ischemia 1: onset of regional dysfunction, i.e., postsystolic shortening and mild hypokinesia) and moderate ischemia (ischemia 2: marked hypokinesia). At each stage, acute afterloading was performed by partially occluding the descending thoracic aorta. The pressure-length loops were analyzed in terms of four areas: total loop area, effective shortening area, postsystolic shortening area and systolic lengthening area. Total loop area decreased only when marked hypokinesia was present (176 +/- 18.3 mm Hg x mm at ischemia 2 versus 245.1 +/- 26.9 mm Hg x mm at ischemia 1, p less than 0.05). However, effective shortening area (98.2 +/- 0.8% of total loop area at baseline; 93.8 +/- 2.4% at critical constriction; 76.3 +/- 7.2% at ischemia 1; 51.9 +/- 12.2% at ischemia 2) and postsystolic shortening area (1.8 +/- 0.8% of total loop area at baseline; 5.2 +/- 1.9% at critical constriction; 14.3 +/- 3/4% at ischemia 1; 23.8 +/- 5.1% at ischemia 2) changed significantly with each progressive stage of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Is esmolol cardioprotective? Tolerance of pacing tachycardia, acute afterloading and hemodilution in dogs with coronary stenosis.

OBJECTIVES: The aim of this study was to determine whether esmolol, an ultrashort-acting beta-adrenergic antagonist, possesses cardioprotective properties unrelated to a concomitant decrease in heart rate. BACKGROUND: Previous studies have demonstrated beneficial effects of beta-adrenergic blocking agents with unchanged heart rates. METHODS: The effect of esmolol (100 micrograms/kg per min) on the response of global cardiovascular and regional myocardial contractile function (sonomicrometry) to pacing-induced tachycardia and acute left ventricular afterloading was assessed in dogs with a critical stenosis of the left anterior descending coronary artery (LAD). These responses were observed at the baseline hemoglobin level (12.5 +/- 0.3 g/100 ml) as well as after hemodilution-induced mild regional contractile dysfunction (7.4 +/- 0.4 g/100 ml) in the area supplied by this artery (LAD area). Data were analyzed by using a repeated measures multivariate analysis of variance with complete block design treating pacing rate and afterloading, respectively, as the repeated measure. RESULTS: Esmolol decreased the maximal first derivative of left ventricular pressure (dP/dtmax); global cardiovascular and regional myocardial contractile function were otherwise unchanged. Esmolol did not alter the response of global cardiovascular or regional myocardial function to pacing-induced tachycardia or to acute left ventricular afterloading, both at the baseline hemoglobin level as well as during mild hemodilution-induced LAD area contractile dysfunction. CONCLUSIONS: At an infusion rate of 100 micrograms/kg per min we were unable to demonstrate cardioprotective esmolol effects in a canine model of critical coronary stenosis with controlled heart rate and identical loading conditions.

Human proinsulin production in primary rat hepatocytes after retroviral vector gene transfer.

The development of autologous somatic cells, engineered for the synthesis and release of human insulin under physiological stimuli, would certainly represent a major breakthrough in the therapy of insulin-dependent diabetes mellitus. We generated a retroviral vector containing the human proinsulin cDNA and the gene coding for the human nerve growth factor receptor for quantitative analysis of transduced cells. Primary rat hepatocytes were selected as target cells because of the constitutive expression of the pancreatic beta-cell glucose transporter GLUT-2 and the glycolitic enzyme glucokinase. Appropriate conditions for culture and retroviral transduction are described. The highest transduction efficiency, evaluated as percentage of LNGFr expressing cells was obtained by repeated infection cycles (40+/-10%). Human proinsulin accumulated in the culture medium of transduced rat hepatocytes (mean+/-SD): 18.1+/-7.9 (range 8.7-36.4) ng/24h/10(6) cells. Primary rat hepatocytes can be efficiently transduced by a retroviral vector and the de novo synthesis of human proinsulin can be induced. Primary cultured hepatocytes represent an useful model to test retroviral constructs engineered for the glucose-inducible expression of insulin under the control of liver-specific promoters.

End systolic pressure-length relations in halothane anaesthetised dogs: effects of regional ischaemia and inotropic agents.

STUDY OBJECTIVE: The aim was to investigate the effects of regional myocardial ischaemia, calcium, and verapamil on (a) the hysteresis and (b) slope and length axis intercept of the left ventricular end systolic pressure-length relationship. DESIGN: Segment length in myocardium supplied by the left anterior descending coronary artery was measured in anaesthetised dogs using sonomicrometry. Three levels of regional myocardial ischaemia were produced by stenosis and occlusion of the left anterior descending artery (ischaemia 1, ischaemia 2, and occlusion). A snare placed around the descending thoracic aorta was used to obtain temporary aortic occlusions. SUBJECTS: Seven open chested mongrel dogs were used, weight 17 kg (range 16-20). MEASUREMENTS AND MAIN RESULTS: After abrupt release of temporary aortic occlusions, end systolic lengths were greater than before the occlusion in the normal myocardium. This hysteresis was abolished by regional myocardial ischaemia. However, hysteresis was insensitive to calcium and verapamil. The length axis intercept of the end systolic pressure-length relationship was increased during ischaemia 2, during coronary occlusion, and after administration of verapamil; its slope was increased after coronary occlusion. CONCLUSIONS: (1) Viscoelastic properties of the myocardium make a major contribution to hysteresis of the end systolic pressure-length relationship; and (2) the length axis intercept of this relationship is not constant and its slope does not appear to be a sensitive indicator of regional myocardial contractility during regional ischaemia.

Effects of progressive myocardial ischaemia on systolic function, diastolic dysfunction, and load dependent relaxation.

OBJECTIVE: The aims were to determine (1) the relationship between changes in contractile function (systolic shortening) and the appearance of diastolic dysfunction (postsystolic shortening) during progressive regional left ventricular ischaemia; (2) the effects of increased afterload (acute constriction of the descending thoracic aorta) on ischaemic contractile dysfunction; and (3) the effects of loading during ischaemia on load dependent relaxation. METHODS: Regional myocardial function, using sonomicrometry, was measured in the short and long axes of the apex of the left ventricle of eight open chest anaesthetised dogs (16-20 kg). Progressive apical ischaemia was induced by graded reductions in left anterior descending coronary artery flow (critical constriction, ischaemia 1, ischaemia 2, total coronary occlusion, and postocclusive maximum reactive hyperaemia). Acute afterloading was induced by a snare placed around the descending aorta. RESULTS: Consistent decreases in systolic shortening and increases in postsystolic shortening relative to the total segmental shortening in the short axis of the apical region were seen with worsening ischaemia. Aortic constriction increased the magnitude of apical postsystolic shortening and decreased apical systolic shortening in the short axis during critical constriction, ischaemia 1, and ischaemia 2. Long axis function changed in a qualitatively similar but quantitatively different manner. There was a significant decrease in the load dependency of relaxation with total coronary occlusion. CONCLUSIONS: (1) Changes in systolic and diastolic function occurred concomitantly as mild regional myocardial ischaemia developed and intensified; (2) afterloading significantly worsened regional systolic and diastolic dysfunction during mild ischaemia; and (3) progression of regional ischaemia resulted in loss of load dependent relaxation.