[Emboligenous hydatid cyst of the right heart]. / Kyste hydatique emboligène du coeur droit.

The cardiac location of the echinococcosis is rare. It is associated with complications potentially severe. Indeed, the break inside the cardiac chambers with pulmonary embolism is the inevitable complication of the echinococcosis of the right heart. Between January 1992 and January 2006, five patients were operated in the department of cardiac surgery of Sousse (Tunisia) for an emboligenous hydatid cyst of the right heart. The average age is of 30 years with extremes from 18 to 65 years. The cardio-pulmonary bypass is the technique of choice. We regretted a single death in immediate postoperative period. All the patients were controlled with an average recession of 36 months. A single late death was noticed. No recurrence was observed.

Human platelet fraction arginine-vasopressin. Potential physiological role.

Arginine-vasopressin (AVP) immunoreactivity (Ir) has been found to be elevated in platelet-rich plasma. PlatAVP was defined as platelet-rich plasma Ir minus platelet-poor plasma Ir (Pavp). PlatAVP, Pavp, and synthetic AVP were found to have identical retention time on high performance liquid chromatography analysis and similar mobility on thin-layer chromatography. During a standard osmotic suppression-stimulation test, Pavp increased with plasma osmolality (Posm, mosmol/kg H2O); Pavp (pg/ml) = 0.98 (Posm -274.4), r = 0.57, P less than 0.001, n = 65; but PlatAVP was not significantly correlated with Posm and remained at 5 pg/ml. This PlatAVP concentration was estimated to represent a true intraplatelet AVP concentration of 0.4 to 3.7 X 10(-9) M. Binding studies on intact human platelets demonstrated specific binding sites for [3H]AVP (n = 16; BMax = 98 +/- 30 binding sites/platelet; Kd = 0.72 +/- 0.24 nM). This in vitro affinity association constant (Kd) was close to the estimated in vivo intraplatelet AVP concentration. Measurement of PlatAVP could estimate vasopressin bound to a specific platelet receptor.

Cytoplasmic dynein function is essential in Drosophila melanogaster.

The microtubule motor cytoplasmic dynein has been implicated in a variety of intracellular transport processes. We previously identified and characterized the Drosophila gene Dhc64C, which encodes a cytoplasmic dynein heavy chain. To investigate the function of the cytoplasmic dynein motor, we initiated a mutational analysis of the Dhc64C dynein gene. A small deletion that removes the chromosomal region containing the heavy chain gene was used to isolate EMS-induced lethal mutations that define at least eight essential genes in the region. Germline transformation with a Dhc64C transgene rescued 16 mutant alleles in the single complementation group that identifies the dynein heavy chain gene. All 16 alleles were hemizygous lethal, which demonstrates that the cytoplasmic dynein heavy chain gene Dhc64C is essential for Drosophila development. Furthermore, our failure to recover somatic clones of cells homozygous for a Dhc64C mutation indicates that cytoplasmic dynein function is required for cell viability in several Drosophila tissues. The intragenic complementation of dynein alleles reveals multiple mutant phenotypes including male and/or female sterility, bristle defects, and defects in eye development.

[Bilateral popliteal artery complications of multiple hereditary exostosis]. / Complications vasculaires poplitées bilatérales d'une exostose héréditaire multiple.

The osseous exostose is a rare benign tumor of the bone from which the vascular complications can be of venous or arterial order, are translated in various boards. We report the case of a young adult who presents a forgery aneurysm of the right popliteal artery with the popliteal artery booby-trapped to the left. The patient benefited from surgical treatment with good clinical and radiological evolution.

[Surgery of 56 patients having a partial atrioventricular septal defect]. / Chirurgie du canal atrioventriculaire partiel : résultats à court et à moyen terme à propos de 56 patients opérés.

Between January 1991 and December 2006, 56 patients having a partial atrioventricular septal defect (AVSD) were operated. The purpose of this retrospective study is to analyze the immediate and long-term results of the surgery by granting of the importance to two main problems which are the disturbances of the rhythm and the conduction and the residual mitral regurgitation (MR). The mean age of our patients is of 10 and a half years with a net feminine ascendancy. Ninety-three percent of the patients were in regular sinus rhythm. No case of complete atrioventricular block (AVB) was noted. The MR was of grade I in 28.5% of the cases, grade II in 60% of the cases and grade III and IV in 7.5% of the cases. The MR was mild in 4% of the cases. The correction was made under cardiopulmonary bypass (CPB) and consisted of a suture of the mitral cleft in most of the cases with lock of the ostium primum by a patch of pericardium. The perioperative mortality was 1,8% of the cases. The disturbances of the rhythm and the conduction were noted in 34% of the cases. All the patients were controlled with a mean follow-up of six years and seven months. The secondary mortality was nil. The MR, at mid-term follow-up, was mild in 78% of the cases. The partial AVSD is a congenital heart disease, the spontaneous evolution of which can be burdened by complications, notably the disturbances of the rhythm and the conduction, as well as the heart failure. This justifies a premature surgical repair.

Hemeral (daily) hemodialysis.

Hemodialysis is generally performed 3 times per week, a treatment prescription not based on optimizing the physiology of the normal kidney that maintains body homeostasis by removing water and waste products continuously and efficiently. Peritoneal dialysis might be continuous but it is not efficient. Daily hemodialysis is both frequent and efficient and theoretically should be superior to other forms of dialysis for renal replacement therapy. There is again a growing interest in daily hemodialysis (it was originally described in 1969), and a number of investigators in North America and Europe are using it. As yet, there have been no randomized prospective studies comparing hard outcomes in patients dialyzed by conventional 3-times-per-week hemodialysis with those treated with daily hemodialysis (either short high-efficiency or long, slow nocturnal). The London, Ontario, study is the first attempt to obtain comparative data. It is a 3-year study to compare daily dialysis patients with cohort controls. To date, the study shows that short daily dialysis does provide more dialysis based on Kt/V than standard therapy. However, predialysis blood urea values are not different because of improved nutrition (increased normalized protein from nitrogen appearance (nPNA) and serum albumin levels). Anemia is improved with less erythropoeitin usage in the study group. Phosphate control is good, but no better than by conventional dialysis and phosphate binders are still required unlike patients receiving nocturnal dialysis. Blood pressure and volume management is better with daily dialysis. So far, the study patients show a trend to less morbidity than their controls, but differences are not (as yet) statistically different. Blood access in daily dialysis dose not cause problems. Quality of life is significantly increased in a number of areas with daily dialysis. The economic impact of daily dialysis is not yet known; the general premise is that the higher dialysis costs attributable to an increment in treatments will be offset by increased wellness and less morbidity with the subsequent beneficial impact on drugs, hospitalizations, and so on. The provision of daily dialysis in the home has attractive economic implications. A considerable growth for this superior form of therapy is expected.

Atrial natriuretic peptide in congestive heart failure: postural changes and reset with chronic captopril therapy.

The response of atrial natriuretic peptide (ANP) to standing and the acute and chronic administration of the vasodilator, captopril, were examined in 15 patients with chronic congestive heart failure. In the supine position, ANP was increased (361 +/- 202 pg/ml); however, only a loose correlation existed between atrial pressures and ANP (right atrial vs ANP, r = 0.03, p = N.S., and pulmonary capillary wedge pressures vs ANP, r = 0.4, p = N.S.). Standing and acute captopril therapy decreased atrial pressures and ANP but did not significantly improve the correlation between atrial pressures and ANP. With chronic captopril therapy, atrial pressures remained decreased; however, ANP had returned to control values (370 +/- 254 pg/ml vs 361 +/- 202 pg/ml) and failed to decrease with standing (370 +/- 259 pg/ml lying vs 351 +/- 194 pg/ml standing). These changes in ANP (with chronic captopril therapy) persisted even once the hemodynamic effects of captopril had dissipated (3 hours post dose). This study indicates that in patients with severe chronic congestive heart failure (1) only a poor correlation exists between ANP and atrial pressures and (2) with chronic captopril therapy ANP increases to higher levels for a given atrial pressure and fails to decrease with standing despite a decrease in atrial pressures.

Effect of usual doses of folate supplementation on elevated plasma homocyst(e)ine in hemodialysis patients: no difference between 1 and 5 mg daily.

Hyperhomocyst(e)inemia is a probable contributor to the excess atherosclerosis of patients with chronic renal failure on dialysis. Although treatment with folate 2 mg daily is usually effective in normalizing plasma homocyst(e)ine (H(e)) in patients with normal renal function, higher doses of folate or other approaches to treatment may be necessary in renal failure. There is no agreement among dialysis units regarding the 'correct' dose of folate supplementation; routine doses range from 1 to 5 mg daily. To determine whether one of these doses is more effective, we compared H(e) in 55 hemodialysis taking 1 mg folate versus 73 patients taking 5 mg folate daily at two dialysis units. In the group as a whole, mean H(e) was 28.23 +/- 17.49, significantly higher than in a group of 290 volunteers with normal renal function 12.31 +/- 6.17 (p = 0. 0001). H(e) levels were 28.93 +/- 16.79 micromol/l on 5 mg folate and 27.31 +/- 18.49 on 1 mg; p = 0.61. There was no significant relationship between adequacy of dialysis (Kt/V) and H(e). In a small group of peritoneal dialysis patients, H(e) was significantly lower at 18.8 +/- 7.89 (p = 0.026), but further study is required in a larger sample to confirm that observation. It appears that routine doses of folate in use in dialysis units are not sufficient to reduce H(e) to levels associated with average cardiovascular risk; new approaches to treatment of hyperhomocyst(e)inemia in dialysis patients are required.

Vasopressin in congestive heart failure.

The mechanisms involved in the abnormal water excretion in patients with congestive heart failure (CHF) are poorly understood. Intrarenal mechanisms (decreased glomerular filtration rate, increased proximal tubular reabsorption) and extrarenal mechanisms (nonosmotic stimulation of arginine vasopressin (AVP)) have been suggested, but their relative importance is unknown. Also, the relationships with altered intracardiac hemodynamics have not been previously assessed. Based on plasma and "platelet" AVP determinations, intracardiac measurements, and other hormonal determinations performed in a series of patients with severe CHF, we conclude that plasma AVP and platelet AVP are the major determinants of the abnormal water excretion in patients with severe CHF. In these patients, enhanced AVP release may be the result of baroreceptor stimulation from a decreased effective arterial blood volume, possibly sensed at specific intraventricular cardiac sites.

A specific antibody to vasopressin in a man with concomitant resistance to treatment with Pitressin.

A 26-year-old man with complete neurogenic diabetes insipidus since age nine was initially treated with vasopressin (Pitressin Tannate in oil). At age 13, its dosages were progressively increased to control the patient's polyuria; minor allergic symptoms occurred after every such treatment. We incubated serial dilutions of the patient's plasma with 125I-labeled arginine-vasopressin and obtained a 50% specific binding for the plasma at a final dilution of 625-fold. Cross-reactivity studies showed that lysine-vasopressin was better recognized by the antibody than arginine-vasopressin. These results were attributed to large concentrations of lysine-vasopressin (pork vasopressin) in the Pitressin.

Neurohumoral and hemodynamic changes in congestive heart failure: lack of correlation and evidence of compensatory mechanisms.

The objective of this study was to assess the hemodynamic and neurohumoral (plasma renin activity, aldosterone, epinephrine, norepinephrine, vasopressin, and atrial natriuretic peptide) determinants of systemic vascular resistance in 35 patients with stable congestive heart failure. In the supine position, although activation of the various neurohumoral systems tended to occur in the same patients, there was little correlation between activation of any of the neurohumoral systems, as reflected by circulating levels, and systemic vascular resistance. There was also little correlation between changes in circulating neurohormones and changes in either mean arterial pressure or systemic vascular resistance in the standing position. Acutely reducing the activity of the renin-angiotensin system with the use of captopril did not improve the correlation between other neurohumoral and hemodynamic variables. In fact there was no correlation between the effects of acute captopril therapy and baseline renin values. These results support the concept that activation of one or another vasoconstrictor neurohumoral system varies from patient to patient and that the effects of their activation are tempered by activation of parallel vasodilator systems and by attenuation of neurohormone release and effector organ response.

Flaxseed in lupus nephritis: a two-year nonplacebo-controlled crossover study.

OBJECTIVE: The objective of this study was to determine the renoprotective effects of ground flaxseed in patients with lupus nephritis. METHODS: Forty patients with lupus nephritis were asked to participate in a randomized crossover trial of flaxseed. Twenty-three agreed and were randomized to receive 30 grams of ground flaxseed daily or control (no placebo) for one year, followed by a twelve-week washout period and the reverse treatment for one year. At baseline and six month intervals, serum phospholipids, flaxseed sachet counts, serum creatinine, 12-hour urine albumin excretion and urine albumin to creatinine ratios, serum viscosity and plasma lipids were measured. RESULTS: There were eight drop-outs and of the 15 remaining subjects flaxseed sachet count and serum phospholipid levels indicated only nine were adherent to the flaxseed diet. Plasma lipids and serum viscosity were unaltered by the flaxseed supplementation whereas serum creatinine in the compliant patients during flaxseed administration declined from a mean of 0.97+/-0.31 mg/dL to a mean of 0.94+/-0.30 mg/dL and rose in the control phase to a mean of 1.03+/-0.28 mg/dL [p value <0.08]. Of the fifteen patients who completed the study, similar changes were noted [p value <0.1]. The nine compliant patients had lower serum creatinines at the end of the two-year study than the 17 patients who refused to participate [p<0.05]. Microalbumin at baseline declined in both control and flaxseed time periods, but there was a trend for a greater decline during flaxseed administration [p<0.2]. CONCLUSIONS: Flaxseed appears to be renoprotective in lupus nephritis, but this interpretation is affected by under powering due to poor adherence and potential Hawthorne effects.

Plasma exchange in rapidly progressive renal failure due to multiple myeloma. A retrospective case series.

BACKGROUND/AIMS: To evaluate the effect of plasma exchange on renal function in patients with rapidly progressive renal failure secondary to multiple myeloma. METHODS: The study was done through a retrospective chart review using a standardized form at a tertiary care centre in southwestern Ontario. Patients were included in the study if they had a diagnosis of multiple myeloma and rapidly progressive renal failure. Multiple myeloma was defined by a bone marrow aspirate >15% plasma cells plus one of the following: serum monoclonal paraproteins, monoclonal light-chain excretion, or lytic lesions. Patients were excluded if they had evidence of chronic renal failure or failed to complete three plasma exchanges. Twenty-six patients were reviewed; of these 24 were followed up to 1 year. All patients received hydration, standard chemotherapy, and plasma exchange. The plasma exchange volume was 50 ml/kg of 50% normal saline and 50% human serum albumin. Primary outcome measures included (1) prevention of acute dialysis and (2) prevention of progression from acute to chronic dialysis; secondary end points included (1) a decrease in creatinine of 25% or more within 3 months of the last plasma exchange and (2) survival at 1 year. RESULTS: Sixteen of 24 patients, followed up to 1 year, did not require dialysis. Two patients required dialysis initially, but were able to come off dialysis after 3 months. Fourteen patients were alive at 1 year, 13 of whom were dialysis independent. Twelve of 13 dialysis-independent patients had a >25% reduction in creatinine at 3 months. Two patients were lost to follow-up after discharge and were not included in the analysis. CONCLUSIONS: This retrospective study suggests that plasma exchange may offer some benefit in preventing the initiation or continuation of dialysis in patients with rapidly progressive renal failure secondary to multiple myeloma. A randomized controlled prospective study is needed to determine whether plasma exchange should be recommended as a standard treatment for patients with rapidly progressive renal failure due to multiple myeloma.

Hemodynamic and coagulation responses to 1-desamino[8-D-arginine] vasopressin in patients with congenital nephrogenic diabetes insipidus.

The antidiuretic hormone arginine vasopressin interacts with two types of receptors: V1, which mediates the effects of vasopressin on vascular smooth muscle, and V2, which mediates the antidiuretic effects on renal tubules. Resistance of the renal tubules to arginine vasopressin and to the antidiuretic V2-specific agonist 1-desamino[8-D-arginine] vasopressin (dDAVP) occurs in congenital nephrogenic diabetes insipidus, a rare X-linked disease, although the V1-receptor responses remain intact. The extrarenal actions of dDAVP in normal persons are a decrease in blood pressure, an increase in plasma renin activity, and stimulation of the release of factor VIIIc and von Willebrand factor. We measured the response of mean arterial pressure, pulse rate, plasma renin activity, factor VIIIc, and von Willebrand factor to an infusion of dDAVP (0.3 microgram per kilogram of body weight) in seven male patients with congenital nephrogenic diabetes insipidus, six obligatory carriers of the gene for nephrogenic diabetes insipidus, five patients with central diabetes insipidus, and four normal subjects. In the normal subjects and the patients with central diabetes insipidus, dDAVP decreased mean arterial pressure (by 10 to 15 percent) and increased pulse rate (by 20 to 25 percent), renin activity (by 65 percent), and the release of coagulation factors (twofold to threefold) (all changes were significant, P less than 0.01). None of these changes were observed in the patients with congenital nephrogenic diabetes insipidus, and minimal responses were observed in the obligatory carriers. These results confirm the existence of extrarenal vasopressin V2-like receptors, which may be defective in patients with congenital nephrogenic diabetes insipidus.

Sodium and water excretion abnormalities in congestive heart failure. Determinant factors and clinical implications.

The renal hemodynamic and neurohumoral determinants of sodium and water excretion abnormalities were studied in 66 patients with severe chronic congestive heart failure. Abnormalities were not closely related to any one variable but were the result of the convergence of a number of determinants. The most important determinants for sodium excretion were activation of the renin-angiotensin system and ventricular function; and the most important for water excretion were plasma vasopressin, plasma norepinephrine, and renal and ventricular functions. In a subgroup of patients, neurohumoral overactivation led to severe sodium and water excretion abnormalities and to increased furosemide requirements. A 17-month follow-up of all 66 patients showed a less favorable clinical course for this subgroup even when compared with hemodynamically matched patients.

Differential long-term intrarenal and neurohormonal effects of captopril and prazosin in patients with chronic congestive heart failure: importance of initial plasma renin activity.

Fifty patients with congestive heart failure received, by infusion, 15 ml/kg body weight water load, and systemic hemodynamic, renal function, and neurohumoral parameters values were measured before, 2 days, and 1 month after randomly allocating patients to prazosin or captopril therapy. Both prazosin and captopril caused similar and persistent hemodynamic changes, but important differences existed between their renal and neurohumoral effects. After 1 month of continuous therapy, captopril increased creatinine clearance from 71 to 84 ml/min/1.73(2) (p less than .05), increased the water load excreted in 5 hr from 50% to 71% (p less than .005), and increased 5 hr sodium excreted from 6.8 to 14.7 meq (p less than .005), Captopril also caused a decrease in plasma norepinephrine from 568 to 448 pg/ml (p less than .005), in plasma epinephrine from 94 to 73 pg/ml (p less than .05), and in plasma aldosterone from 57 to 28 ng/dl (p less than .005), without changing plasma vasopressin. These beneficial effects were greater after 1 month of therapy than after 2 days. The only beneficial effect of prazosin was to increase water excretion from 49% to 59% (p less than .05). The long-term response to captopril was similar in patients with higher (greater than 2.5 ng/ml/hr) and lower renin levels. However, in patients with lower renin levels, prazosin decreased pulmonary capillary wedge pressure (24.8 to 21.8 mm Hg, p less than .05), decreased plasma arginine vasopressin (1.16 to 0.75 pg/ml, p less than .05), increased water excretion (62% to 85%, p less than .005), and decreased plasma epinephrine (81 to 46 pg/ml, p less than .05), while in patients with higher renin levels none of these beneficial effects were noted. We conclude that captopril produces long-term beneficial renal and neurohumoral effects that prazosin does not despite similar hemodynamic changes with the two drugs, that these effects are at least partially dependent on the initial neurohumoral and hemodynamic status of the patient, and that through hemodynamic improvement vasodilators may chronically interrupt vasopressin overstimulation.

Modulation of plasma and platelet vasopressin by cardiac function in patients with heart failure.

Two groups of patients with congestive heart failure were studied, one with elevated (Group I) and another (Group II) with suppressed plasma concentrations of vasopressin. The mean plasma arginine vasopressin (AVP) concentration in the 17 patients in group I was 3.1 +/- 0.4 pg/mliter whereas the eight patients in group II had plasma concentration less than 0.5 pg/mliter. Platelet AVP concentrations were also higher in the Group I than Group II patients (7.8 +/- 1.5 vs. 2.2 +/- 0.7 pg/mliter, P less than 0.001). Plasma effective osmolality (262 vs. 268 mOsm/kg H2O, P less than 0.05) and plasma sodium concentration (134 vs. 137 mEq/liter, P less than 0.05) were lower in Group I. The Group I patients had a lower cardiac index (CI, 1.9 vs. 2.5 liter/min/m2, P less than 0.05) and higher pulmonary capillary wedge pressure (PCWP, 30 vs. 22 mm Hg, P less than 0.02), plasma renin activity (4.4 vs. 2.0 ng/mliter/hr, P less than 0.01), and plasma aldosterone (74 vs. 10 ng/dliter, P less than 0.001) than the Group II patients. The Group I patients also excreted a smaller percentage of a 15 mliter/kg waterload (31 vs. 57%, P less than 0.005). Group I patients then were treated with agents to decrease cardiac afterload, either captopril or prazosin. CI increased (1.9 to 2.1 liter/min/m2, P less than 0.001) and PCWP decreased (30 to 27 mm Hg, P less than 0.001). This improved cardiac performance was associated with enhanced water excretion (31 vs. 52%, P less than 0.001) and decreased minimal urinary osmolality (375 vs. 208 mOsm/kg H2O, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)