Transmural cardiac strains in the lateral wall of the ovine left ventricle.

The constant-volume property of contracting cardiac muscle has been invoked in models of heart wall mechanics that predict that systolic subendocardial left ventricular (LV) wall thickening must significantly exceed subepicardial thickening. To examine this prediction, we implanted arrays of radiopaque markers to measure lateral equatorial wall transmural strains and global and regional LV geometry in seven sheep and studied the four-dimensional dynamics of these arrays using biplane videofluoroscopy (60 Hz) in anesthetized intact animals 1 and 8 wk after surgery. A transmural gradient of systolic lateral wall thickening was observed at 1 wk (P = 0.

Direct measurement of transmural laminar architecture in the anterolateral wall of the ovine left ventricle: new implications for wall thickening mechanics.

Laminar, or sheet, architecture of the left ventricle (LV) is a structural basis for normal systolic and diastolic LV dynamics, but transmural sheet orientations remain incompletely characterized. We directly measured the transmural distribution of sheet angles in the ovine anterolateral LV wall. Ten Dorsett-hybrid sheep hearts were perfusion fixed in situ with 5% buffered glutaraldehyde at end diastole and stored in 10% formalin.

An in vitro study on the mechanisms of coagulation activation in acute myelogenous leukemia (AML): role of tissue factor regulation by cytotoxic drugs and GM-CSF.

AML patients may suffer from a disseminated coagulopathy, which can aggravate a pre-existing bleeding tendency due to thrombocytopenia and platelet dysfunction. The cellular and molecular mechanisms underlying this coagulopathy, however, are not completely understood. Indeed, the broad and increasing therapeutic use of cytotoxic drugs and growth factors is likely to contribute to the complexity of hemostatic abnormalities encountered in this hematologic malignancy.

Valve-sparing aortic root replacement in bicuspid aortic valves: a reasonable option?

Objectives: Aortic dilatation occurs in many patients with bicuspid aortic valves. We have added root replacement using the remodeling technique originally designed for tricuspid aortic valves to bicuspid aortic valve repair for treatment of the dilated root. We compared the results of remodeling in bicuspid aortic valves with those in tricuspid aortic valves.

Increases in mitral leaflet radii of curvature with chronic ischemic mitral regurgitation.

Background And Aim Of The Study: Leaflet curvature is a primary determinant of leaflet stress, but no quantitative in-vivo leaflet curvature data exist. Chronic ischemic mitral regurgitation (CIMR) is associated with remodeling of the valvular-ventricular complex. It was hypothesized that leaflet radii of curvature (ROC) would change with such remodeling.

[Epigenetic changes in breast cancer shown by aberrant promoter methylation].

The aberrant methylation of cytosine residues in the promoter region of growth-regulatory genes is now recognized as an important inactivation mechanism in addition to deletion and mutation in the development and progression of cancer. Principally all pathways regulating proliferation and differentiation, which are perturbed in cancer cells, can be affected. In breast cancer epigenetic inactivation is a frequent and early event displaying great quantitative gene-specific differences during progression.

[Surgical treatment of obesity].

At the beginning of the 21st century, obesity has become an epidemic with the greatest prevalence in the western world. For morbidly obese patients, conservative treatment has yielded disappointing results: On the other hand, bariatric surgery offers a sustained substantial weight loss for these patients. Common bariatric procedures including results and complications are described.

Importance of mitral valve second-order chordae for left ventricular geometry, wall thickening mechanics, and global systolic function.

Background: Mitral valvular-ventricular continuity is important for left ventricular (LV) systolic function, but the specific contributions of the anterior leaflet second-order "strut" chordae are unknown.

Methods And Results: Eight sheep had radiopaque markers implanted to silhouette the LV, annulus, and papillary muscles (PMs); 3 transmural bead columns were inserted into the mid-lateral wall between the PMs. The strut chordae were encircled with exteriorized wire snares.

Alterations in left ventricular torsion and diastolic recoil after myocardial infarction with and without chronic ischemic mitral regurgitation.

Background: Chronic ischemic mitral regurgitation (CIMR) is associated with heart failure that continues unabated whether the valve is repaired, replaced, or ignored. Altered left ventricular (LV) torsion dynamics, with deleterious effects on transmural gradients of oxygen consumption and diastolic filling, may play a role in the cycle of the failing myocardium. We hypothesized that LV dilatation and perturbations in torsion would be greater in animals in which CIMR developed after inferior myocardial infarction (MI) than in those that it did not.

Undersized mitral annuloplasty alters left ventricular shape during acute ischemic mitral regurgitation.

Background: Underlying left ventricular (LV) dysfunction contributes to poor survival after operation to correct ischemic mitral regurgitation (IMR). Many surgeons do not appreciate that a key component of the Bolling undersized mitral ring annuloplasty concept is to decrease LV wall stress by altering LV shape, but precise 3-dimensional (3-D) geometric data do not exist substantiating this effect. We tested the hypothesis that annular reduction decreases regional circumferential LV radius of curvature (ROC) in a model of acute IMR.

Cutting second-order chords does not prevent acute ischemic mitral regurgitation.

Background: Cutting anterior mitral leaflet second-order chordae has been proposed for repair in ischemic mitral regurgitation (IMR). We examined the efficacy of such chordal cutting in preventing acute IMR.

Methods And Results: Six sheep underwent radiopaque marker placement (left ventricle, mitral annulus, papillary muscles [PMs], and leaflets).

Effects of paracommissural septal-lateral annular cinching on acute ischemic mitral regurgitation.

Background: Previous experimental studies demonstrated that central septal-lateral (SL) annular cinching (SLAC) abolishes acute ischemic mitral regurgitation (IMR), but whether localized cinching near the anterior (ACOM) or posterior (PCOM) commissure is equally effective is unknown.

Methods: Six adult sheep underwent implantation of 9 radiopaque markers on the left ventricle, 8 around the mitral annulus (MA) and 1 on each papillary muscle (PM) tip. Transannular SL sutures were placed at the valve center (CENT) and near ACOM and PCOM and externalized.

Aortic valve repair using a differentiated surgical strategy.

Background: Reconstruction of the aortic valve for aortic regurgitation (AR) remains challenging, in part because of not only cusp or root pathology but also a combination of both can be responsible for this valve dysfunction. We have systematically tailored the repair to the individual pathology of cusps and root.

Methods: Between October 1995 and August 2003, aortic valve repair was performed in 282 of 493 patients undergoing surgery for AR and concomitant disease.

[Morphological response to therapy of breast carcinoma].

Neoadjuvant chemotherapy has been extended to earlier stages of breast carcinoma in order to increase the rate of breast conservation by downstaging. Tumour regression can be observed in up to 80% of the cases and the chemosensitivity of the individual tumour can be studied in vivo. Moreover therapy induced regression has been established as an independent prognostic parameter.

[Iloprost and selective pulmonary vasodilation. Clinical results of intraoperative and postoperative inhalation of iloprost].

Pulmonary hypertension is a major risk factor in cardiac surgery and has significant impact on morbidity and mortality in the perioperative period. Nitric oxide (NO) is considered to be the gold standard for treatment of pulmonary hypertension in the perioperative setting. The aerosolized administration of the prostacyclin analogue iloprost is a new alternative with similar pulmonary-selective vasodilation and virtually no systemic side-effects.

Overexpression of delta-like (Dlk) in a subset of myelodysplastic syndrome bone marrow trephines.

The mRNA expression level of the gene delta-like (Dlk), coding for a signal transducer related to the Delta-Notch family, was measured using real-time PCR methodology in a large series of control biopsies (n = 61) and bone marrow trephines from patients with myelodysplastic syndrome (MDS) (n = 93) and related myeloid disorders (AML, n = 16 and chronic myeloproliferative disease (CMPD), n = 38). It turned out that dlk is strongly overexpressed in a subset of MDS (16%) cases, however with higher frequency in blast rich MDS cases. Therefore, the quantitative detection of dlk mRNA can support the morphological diagnosis of MDS in selected cases.

Cytokine response to pulmonary thromboendarterectomy.

Background: Pulmonary thromboendarterectomy (PTE) is an effective but challenging treatment for chronic thromboembolic pulmonary hypertension (CTEPH). PTE is associated with marked hemodynamic instability in the perioperative course, suggesting the involvement of circulating mediators. The aim of this study was to characterize the expression of proinflammatory and anti-inflammatory cytokines in patients undergoing PTE.

Yersinia infection mimicking recurrence of gastrointestinal stromal tumor.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. So far, surgical resection has been the only curative treatment, but new options became available with the application of imatinib (Glivec) as a specific molecular inhibitor. Even after complete resection, GISTs have a high rate of recurrence and disease-linked mortality.

Mitral suture annuloplasty corrects both annular and subvalvular geometry in acute ischemic mitral regurgitation.

Background And Aim Of The Study: Papillary muscle displacement is an important element in the pathogenesis of ischemic mitral regurgitation (IMR). The effects of standard ring annuloplasty on subvalvular geometry are incompletely understood. The hypothesis was tested that annular reduction with a Panethtype suture annuloplasty would correct both annular and papillary muscle geometric abnormalities during acute left ventricular (LV) ischemia.

Histidine-tryptophan-ketoglutarate solution for organ preservation in human liver transplantation-a prospective multi-centre observation study.

Based on experimental work and clinical small studies, histidine-tryptophan-ketoglutarate (HTK) solution was found to be suitable not only for heart and kidney preservation but also for liver preservation. We decided, therefore, to use this preservation solution for clinical liver preservation in a prospective multi-centre trial. Enrolment to the study was from 1996 to 1999 in four European centres, and the results of 214 patients with HTK-preserved organs were analysed.

Anatomic basis of right renal vein extension for cadaveric kidney transplantation.

Objectives: The right renal vein (RRV) may be difficult to anastomose in right cadaveric kidney transplantation, especially in obese recipients in whom iliac vessels are deep. In this study, gain of length and feasibility in the presence of vascular variations obtained with three common techniques of renal vein augmentation--clamshell (CS), transverse closure of the inferior vena cava (TC), and cava conduit (CC)--were analyzed and compared to the Carrel-patch technique.

Methods: The renal vasculature and the inferior vena cava of 119 cadavers were accurately dissected and measured, and the vascular variations documented.

[Osteosarcoma of the pelvisTwo case reports and review of the literature].

Primary malignant neoplasms of the bone are rare. One of the most common bone tumors is osteosarcoma, most often localized in the metaphysis of adolescent long bones. The sacrum is concerned in only about 1%.

Does septal-lateral annular cinching work for chronic ischemic mitral regurgitation?

Objectives: Ring annuloplasty, the current treatment of choice for chronic ischemic mitral regurgitation, abolishes dynamic annular motion and immobilizes the posterior leaflet. In a model of chronic ischemic mitral regurgitation, we tested septal-lateral annular cinching aimed at maintaining normal annular and leaflet dynamics.

Methods: Twenty-five sheep had radiopaque markers placed on the mitral annulus and anterior and posterior mitral leaflets.