Five-year results of a randomized trial comparing de novo sirolimus and cyclosporine in renal transplantation: the SPIESSER study.

Calcineurin inhibitors improve acute rejection rates and short-term graft survival in renal transplantation, but their continuous use may be deleterious. We evaluated the 5-year outcomes of sirolimus (SRL) versus cyclosporine (CsA) immunosuppressive treatment. This observational study was an extension of the SPIESSER study where deceased donor kidney transplant recipients were randomized before transplantation to a SRL- or CsA-based regimen and followed up 1 year. Data from 131 (63 SRL, 68 CsA) out of 133 patients living with a functional graft at 1 year were collected retrospectively at 5 years posttransplant. Seventy percent of CsA patients versus 54% of SRL patients were still on the allocated treatment at 5 years (p = 0.091), most discontinuations in each group being due to safety issues. In intent-to-treat, mean MDRD eGFR was higher with SRL: 54.2 versus 45.3 mL/min with CsA (p = 0.019); SRL advantage was greater in on-treatment analyses. There were no differences for patient survival (p = 0.873), graft survival (p = 0.121) and acute rejection (p = 0.284). Adverse events were more frequent with SRL (80% vs. 60%, p = 0.015). Results confirmed the high SRL discontinuation rate due to adverse events. Nevertheless, a benefit was evidenced on renal function in patients (more than 50%) still on treatment at 5 years.

Measurement of lactose repressor-mediated loop formation and breakdown in single DNA molecules.

In gene regulatory systems in which proteins bind to multiple sites on a DNA molecule, the characterization of chemical mechanisms and single-step reaction rates is difficult because many chemical species may exist simultaneously in a molecular ensemble. This problem was circumvented by detecting DNA looping by the lactose repressor protein of Escherichia coli in single DNA molecules. The looping was detected by monitoring the nanometer-scale Brownian motion of microscopic particles linked to the ends of individual DNA molecules. This allowed the determination of the rates of formation and breakdown of a protein-mediated DNA loop in vitro. The measurements reveal that mechanical strain stored in the loop does not substantially accelerate loop breakdown, and the measurements also show that subunit dissociation of tetrameric repressor is not the predominant loop breakdown pathway.

Direct mechanical measurements of the elasticity of single DNA molecules by using magnetic beads.

Single DNA molecules were chemically attached by one end to a glass surface and by their other end to a magnetic bead. Equilibrium positions of the beads were observed in an optical microscope while the beads were acted on by known magnetic and hydrodynamic forces. Extension versus force curves were obtained for individual DNA molecules at three different salt concentrations with forces between 10(-14) and 10(-11) newtons. Deviations from the force curves predicted by the freely jointed chain model suggest that DNA has significant local curvature in solution. Ethidium bromide and 4',6-diamidino-2-phenylindole had little effect on the elastic response of the molecules, but their extent of intercalation was directly measured. Conversely, the effect of bend-inducing cis-diamminedichloroplatinum (II) was large and supports the hypothesis of natural curvature in DNA.

Contribution of solid-phase hexapeptide ligand libraries to the repertoire of human bile proteins.

Proteins in bile may have important physiological functions and serve as disease biomarkers. Here, the protein composition of human gallbladder bile was analyzed using a recently described chromatography-like technology capable to enhance the signal of low-abundance species. First, proteins present in bile fluid were treated with immobilized peptide ligand libraries to concentrate dilute and very dilute species while concomitantly diluting the high-abundance proteins. The analysis of resulting protein mixture was then performed using LC-MS/MS after having classically separated proteins by a mini preparative gel electrophoresis. Overall 222 gene products were found; 143 of them were not reported before in proteomics studies. Ligand libraries by themselves contributed to find 81 new gene products distributed throughout different categories. The described chromatographic approach provides a significant contribution to the bile protein repertoire and opens new perspectives for the discovery of markers for specific biliary tract diseases.

Multiplexed, Tethered Particle Microscopy for Studies of DNA-Enzyme Dynamics.

DNA is the carrier of genetic information and, as such, is at the center of most essential cellular processes. To regulate its physiological function, specific proteins and motor enzymes constantly change conformational states with well-controlled dynamics. Twenty-five years ago, Schafer, Gelles, Sheetz, and Landick employed the tethered particle motion (TPM) technique for the first time to study transcription by RNA polymerase at the single-molecule level. TPM has since then remained one of the simplest, most affordable, and yet incisive single-molecule techniques available. It is an in vitro technique which allows investigation of DNA-protein interactions that change the effective length of a DNA tether. In this chapter, we will describe a recent strategy to multiplex TPM which substantially increases the throughput of TPM experiments, as well as a simulation to estimate the time resolution of experiments, such as transcriptional elongation assays, in which lengthy time averaging of the signal is impossible due to continual change of the DNA tether length. These improvements allow efficient study of several DNA-protein systems, including transcriptionally active DNA-RNA polymerase I complexes and DNA-gyrase complexes.

A novel LKB1 isoform enhances AMPK metabolic activity and displays oncogenic properties.

The LKB1 tumor suppressor gene encodes a master kinase that coordinates the regulation of energetic metabolism and cell polarity. We now report the identification of a novel isoform of LKB1 (named ΔN-LKB1) that is generated through alternative transcription and internal initiation of translation of the LKB1 mRNA. The ΔN-LKB1 protein lacks the N-terminal region and a portion of the kinase domain. Although ΔN-LKB1 is catalytically inactive, it potentiates the stimulating effect of LKB1 on the AMP-activated protein kinase (AMPK) metabolic sensor through a direct interaction with the regulatory autoinhibitory domain of AMPK. In contrast, ΔN-LKB1 negatively interferes with the LKB1 polarizing activity. Finally, combining in vitro and in vivo approaches, we showed that ΔN-LKB1 has an intrinsic oncogenic property. ΔN-LKB1 is expressed solely in the lung cancer cell line, NCI-H460. Silencing of ΔN-LKB1 decreased the survival of NCI-H460 cells and inhibited their tumorigenicity when engrafted in nude mice. In conclusion, we have identified a novel LKB1 isoform that enhances the LKB1-controlled AMPK metabolic activity but inhibits LKB1-induced polarizing activity. Both the LKB1 tumor suppressor gene and the oncogene ΔN-LKB1 are expressed from the same locus and this may account for some of the paradoxical effects of LKB1 during tumorigenesis.

Superior vena cava syndrome of malignant origin. Which surgical procedure for which diagnosis?

OBJECTIVE: Since some malignancies causing superior vena cava syndrome (SVCS) are only sensitive to a specific treatment regimen, it is crucial to diagnose the underlying pathology in such cases. The aim of the present study was to review the surgical procedures used to establish the aetiology of SVCS of a malignant origin. METHODS: This retrospective study was based on a series of 88 patients referred to surgeons for SVCS, for whom biological and/or endoscopic procedures had failed to establish the diagnosis. On the basis of the results of clinical examination, biological tests and CT-scan presentation, we performed 99 sampling procedures to obtain a diagnosis for all 88 patients. These procedures were the following: biopsy of peripheral adenopathy (n=11), CT-guided biopsy (CTGB; n=23), axial mediastinoscopy (MDS; n=23), anterior mediastinotomy (n=26), anterior mediastinoscopy (n=6), biopsy of the suprascapular mass (n=3), pericardioscopy (n=3), thoracoscopy (n=1), thoracotomy (n=2) and sternotomy (n=1). RESULTS: Per-operative morbidity consisted of one case of massive venous bleeding during MDS requiring a salvage sternotomy to achieve hemostasis. The diagnoses finally established for the 88 patients were non-Hodgkin's lymphoma (NHL) for 36, small cell lung cancer for 25, non-small cell lung cancer for 17, Hodgkin's disease for five, thymoma for three, germ cell tumour for one and sarcoma for one. For the diagnosis of lung cancer, the sensitivities of CTGB and MDS were 85 and 100%, respectively. For the diagnosis of NHL, the sensitivity of anterior mediastinotomy was 95%. CONCLUSION: The surgical diagnostic procedure, chosen on the basis of the clinical presentation and CT-scan, can be performed safely in the case of SVCS, with the same accuracy as in the absence of this syndrome. Among the patients referred to surgeons, NHL is the most frequent aetiology of SVCS, together with small cell lung cancer.

Pericardoscopy for primary management of pericardial effusion in cancer patients.

OBJECTIVE: To assess the usefulness of pericardoscopy via the subxyphoid route for the diagnosis and treatment of pericardial effusion in patients with a history of cancer. METHODS: All patients with a recent or remote history of cancer and a pericardial effusion of unknown origin requiring drainage for diagnostic and therapeutic purposes were included in the study. They underwent complete exploration and cleansing of the pericardial cavity. Abnormal structures or deposits were biopsied under direct visual control, with a 24 cm long rigid pericardoscope. RESULTS: Between 1985 and 1998, pericardoscopy was completed in 112 of the 114 patients included (feasibility 98%), resulting in the immediate relief of symptoms in all the cases. Peri-operative mortality was 3.5%, and post-operative morbidity, 6.1%. After pericardioscopy pericardial effusions were considered malignant in 43 cases. One more case (2.3%) due to a false negative result of pericardioscopy was diagnosed during follow-up. Overall, 44 of the 114 patients (38.6%) had a malignant effusion, and 70 (61.4%), a non-malignant effusion according the follow up. In 10 of the 44 patients with a malignant pericardial effusion (22.7%), pericardoscopy corrected the results of cytological pericardial fluid studies and pericardial window biopsy, both false negatives. The sensitivities of cytological studies of the pericardial fluid, pathological examinations of pericardial window biopsy and pericardioscopy were 75, 65 and 97%, respectively. One patient with a malignant effusion had a non-symptomatic recurrence 1 month after pericardioscopy (2.3%). CONCLUSION: We recommend pericardioscopy to ascertain the malignant nature of the effusion and to diminish the recurrence rate, this avoiding repeat procedures in patients with a short life expectancy.

Labeling phosphorylated LHCII with microspheres for tracking studies and force measurements.

We report a method to selectively label phosphorylated, membrane proteins with microscopic particles. This technology is particularly useful in single particle studies. In such studies, the particles may serve to visualize protein diffusion and/or as 'handles' to study the force of interaction between the labeled protein and the membrane matrix. In the latter kind of experiments, forces can be applied and measured by calibrated optical tweezers. Optical tweezers were used in this work to test the strength of the particle labeling. Labeling a single protein with a particle produces a long-lived, distinct tag and is particularly useful for proteins in photosynthetic membranes, which contain endogenous fluorophores that would render single fluorescent proteins difficult to detect.

Chronic Chagas' heart disease presenting as an impending myocardial infarction: a case favoring the neurogenic pathogenesis concept.

A 55-year-old Caucasian woman suddenly developed substernal chest pain at rest accompanied by pallor, diaphoresis, nausea, and vomiting. Physical examination was otherwise unremarkable. The resting ECG showed T-wave inversion in all anterior leads which returned to normal 24 h after the onset of the symptoms. The pain was eliminated promptly by sublingual isosorbide dinitrate. "Impending" acute myocardial infarction was diagnosed. Coronary arteriography, however, failed to reveal any change in any major coronary artery but an apical aneurysm of the left ventricle was detected. As the complement-fixation test for Chagas' disease was positive, the diagnosis of chronic Chagas' heart disease was then established. This unusual clinical manifestation of Chagas' disease is thought to be the consequence of a transient imbalance in the cardiac autonomic nervous system, which is considered to play a central role in the pathogenesis of chronic Chagas' heart disease. In addition, the present case may alert clinicians to the thus far neglected atypical chest pain, which is frequently seen in chagasic patients but whose etiology remains obscure.

Myocardial bridging of coronary arteries associated with an impending acute myocardial infarction.

A 57-year-old woman developed severe substernal chest pain radiating to the left arm accompanied by pallor and marked diaphoresis. These symptoms appeared at rest, lasted 45 minutes, and terminated spontaneously. The patient had been treated for mild hypertension during the last 6 months. An ECG tracing obtained at the beginning of treatment was unremarkable. However, an ECG tracing recorded shortly after the end of the symptoms showed T-wave inversion in all anterior leads. Coronary arteriography was then performed and showed no fixed obstructive coronary artery disease. Nonetheless, a lengthened and constricted myocardial bridging of both the left anterior descending coronary artery and its major diagonal branch was detected. Also, the left anterior descending coronary artery was observed to be very short, terminating before the cardiac apex. The left ventricle was hypertrophied. The patient was treated with a beta-blocking agent which eliminated all symptoms. An ECG tracing obtained about three months after the onset of the clinical picture was normal. Our findings suggest that marked myocardial ischemia at rest does occur in patients having myocardial bridges under special circumstances, such as lengthened and constricted myocardial bridging of a short coronary artery which supplies a hypertrophied ventricle. This anomaly should be taken into account as a possible cause of a threatened myocardial infarction, which may be successfully treated with a beta-blocking agent.

Impending myocardial infarction in a patient with marked left ventricular hypertrophy and normal coronary arteriogram--a case report.

A middle-aged woman with long-term uncontrolled arterial hypertension developed a clinical picture of impending myocardial infarction. A normal coronary arteriogram was obtained. However, left heart catheterization showed a marked increase in left ventricular end-diastolic pressure, while left angiocardiography revealed marked left ventricular hypertrophy. She was successfully treated with a beta-blocking and calcium-antagonist agent. The present case shows that an impending myocardial infarction may occur in patients having normal coronary arteriogram but with left ventricular hypertrophy secondary to arterial hypertension.

Myocardial reperfusion by thrombolysis after acute total left main artery occlusion--a case report.

Coronary recanalization with thrombolytic agents is a new therapeutic approach to the treatment of acute myocardial infarction that can be beneficial even to patients in cardiogenic shock. Although few cases have been reported in the literature, treatment of acute occlusion of the left main coronary artery (LMCA) has been made possible by myocardial reperfusion. This communication concerns a patient with acute LMCA occlusion who was successfully treated by thrombolytic therapy with streptokinase followed by revascularization of the myocardium seventy-two hours after reperfusion was achieved.

[Oesophageal cancer in patients with head and neck cancers: therapeutic implications]. / Association cancers de l'oesophage et des voies aérodigestives supérieures : implications thérapeutiques.

AIM OF THE STUDY: To determine therapeutic and prognostic implications of an associated head and neck primary cancer in patients undergoing oesophagectomy for squamous cell carcinoma of the oesophagus. PATIENTS AND METHODS: Between 1982 and 2000, 868 patients with oesophageal cancer were operated in our institution, including 78 (9%) who underwent oesophagectomy for associated oesophageal and head and neck cancers; the latter was synchronous (n = 52) or anterior metachronous (n = 26). Influence of head and neck cancer on the treatment of oesophageal carcinoma was analysed retrospectively in terms of surgical therapeutic strategy and survival. RESULTS: Oesophageal resection consisted of oeso-pharyngolaryngectomy (n = 14, 17.9%), subtotal oesophagectomy (n = 62, 79.5%) and cervical oesophagectomy (n = 2, 2.6%). Radical resection (R0) was obtained in 85% of cases. Postoperative mortality rate was 5 % (4/78). Main complications were pulmonary (18% = 14/78) and anastomotic leaks (14% = 11/78), all of them cervical. Follow-up (mean = 25 +/- 27 months) was complete for all 78 patients. Five-year survival after R0 resection was 25%. Survival pronostic factors were denutrition, complete resection, and pT status of oesophageal tumor. CONCLUSION: In patients with associated carcinomas of oesophagus and head and neck, agressive treatment -including an oesophagectomy- allowed a 5-year survival rate more than 25% without increased mortality or morbidity rates, compared with patients operated on for isolated oesophageal carcinoma.

[Aortic coarctation associated with a large aneurysm]. / Coarctação da aorta associada a grande aneurisma.

The case of a symptomatic 16-year-old girl, referred with the diagnosis of coarctation of the aorta is presented. Aortography showed a severe coarctation and a huge aneurysm distal to the coarctation. Successful operation was performed with resection of the coarctation and aneurysm and interposition of a tube of bovine pericardium for the anastomosis. Two months after the operation the blood pressure was normal and a 10 mm/Hg gradient was detected by doppler-echocardiography.

[Complete heart block after percutaneous mitral valvotomy with Inoue balloon]. / Bloqueio atrioventricular completo após valvoplastia mitral percutânea com balão de Inoue.

We report a permanent complete heart block, in a 27 year-old female patient, developed during mitral percutaneous valvotomy using a single inflation of the Inoue balloon catheter. After one month, even using corticoids, a Mobitz II second-degree atrioventricular block persisted, the patient became symptomatic to moderate efforts and a cardiac pacemaker was implanted.

[Initial experience with partial left ventriculectomy as a treatment for end-stage heart failure]. / Experiência inicial com a ventriculectomia parcial esquerda no tratamento da insuficiência cardíaca terminal.

PURPOSE: To evaluate the efficacy of left ventriculectomy, on a short term basis, as a treatment for patients with end-stage heart failure. METHODS: From February to June 1995, 7 patients with end-stage heart failure underwent partial left ventriculectomy. Before the surgical procedure, 7 (100%) patients were in functional class IV. Three (42%) patients needed inotropic support for hemodynamic stability. The mean daily dose of furosemide was l48.67 +/- 128.27 mg, of captopril 87.50 +/- 95.20 mg and of digoxin 0.23 +/- 0.04. Mean left ventricular diastolic dimension determined by 2-D echocardiography was 78.29 +/- 12.63 mm, mean left ventricular ejection fraction, determined by radionuclide ventriculography, was 0.15 +/- 0.05 whereas mean transpulmonary gradient and pulmonary vascular resistance in Wood units, determined by right heart catheterization, were 16.80 +/- 8.80 and 6.57 +/- 3.22, respectively. RESULTS: Sixty days after the surgery, the mean functional class was 1.71 +/- 0.48 (p = 0.009), the mean left ventricular diastolic dimension 64.67 +/- 11.41 mm (p = 0.02) and the mean left ventricular ejection fraction 0.22 +/- 0.04 (p = 0.02). CONCLUSION: The left ventriculectomy is a promising treatment for patients with end-stage heart failure.

[Clinical course of patients treated with partial left ventriculectomy]. / Evolução clínica de pacientes submetidos à ventriculectomia esquerda parcial.

OBJECTIVE: To assess the efficacy of partial left ventriculectomy as a treatment for patients with end-stage heart failure. METHODS: From February to June 1995, 7 patients with end-stage heart failure underwent partial left ventriculectomy. Subsequently, patients underwent clinical evaluation every 2 months, and 2-dimensional echocardiography at the 6th and 12th months after cardiac surgery. All patients were given digitalis and diuretics at conventional doses, and captopril or enalapril at maximal tolerated doses. RESULTS: Two (28%) patients died; 1 from cardiac arrhythmia associated with gastrointestinal hemorrhage, and the other suddenly. One (14%) patient developed an embolic cerebrovascular accident. Four (57%) patients were hospitalized for congestive heart failure; all of them had either decreased the daily dose of captopril or enalapril or discontinued the drugs by themselves. Twelve months after ventriculectomy, left ventricular ejection fraction values were greater and left ventricular diastolic dimension and functional class values lower than those found before cardiac operation. CONCLUSION: Beneficial effects of partial left ventriculectomy are observed one year after the surgical procedure. This technique, therefore, can be useful for the treatment of patients with end-stage heart failure.

[Atrial septal defect percutaneous transvenous occlusion with the buttoned device]. / Oclusão percutânea transvenosa de comunicação interatrial mediante utilização do buttoned device.

PURPOSE: To analyse the experience with the use of Sideris' device for percutaneous transvenous occlusion of atrial septal defect (ASD). METHODS: Thirty six procedures of ASD occlusion were performed in 32 patients; 27 (84.4%) female and five (15.6%) male, mean age of 16 years (4-61). All patients had secundum atrial septal defects with clinical and hemodynamic compromise. The ASD diameter measured < 31 mm and occupied less than 50% of the septal length in all cases. The basic device was used in 28 (87.5%) patients and the self centered model in four (12.5%). The direct implant technique was employed in 15 (41.7%) procedures while in the other 21 (58.3%) an over a wire technique was used. The size of the device was selected according with the Sideris' normogram. RESULTS: Occlusion of the defect was achieved in 29 patients (90.63%). In two (6.25%) the position of the device was not adequate and in one (3.12%) the device embolized to the pulmonary artery. In these three cases the device was removed surgically during the defect closure. There was neither morbidity nor mortality in this series. Trivial or small residual shunt was detected with color flow mapping in three (9.4%) patients immediately after the procedure. In 22 patients with 12 months follow-up, trivial residual shunt was present in only one (4.5%). Structural modification of the device was detected in one patient, however with complete ASD occlusion and neither clinical nor hemodynamic disturbance. CONCLUSION: The Sideris' device is safe and efficient for ASD occlusion in selected patients. Although there is a relatively high incidence of residual shunt immediately after the procedure, the shunt itself tends to become smaller or disappear during the follow-up and it does not preclude clinical and hemodynamic improvement.