The levels of adrenomedullin (ADM), a newly discovered vasodilating and natriuretic peptide, are elevated in plasma and ventricular myocardium in human congestive heart failure suggesting that cardiac synthesis may contribute to the plasma concentrations of ADM. To examine the time course of induction and mechanisms regulating cardiac ADM gene expression, we determined the effect of acute and short-term cardiac overload on ventricular ADM mRNA and immunoreactive ADM (ir-ADM) levels in conscious rats. Acute pressure overload was produced by infusion of arginine8-vasopressin (AVP, 0.05 microg/kg/min, i.v.) for 2 h into 12-week-old hypertensive TGR(mREN-2)27 rats and normotensive Sprague-Dawley (SD) rats. Hypertension and marked left ventricular hypertrophy were associated with 2.2-times higher ir-ADM levels in the left ventricular epicardial layer (178 +/- 36 vs. 81 +/- 23 fmol/g, P
199 arthroscopies were performed on children with non-acute knee problems during 1985-1992 at the University Hospital of Oulu (76 boys and 123 girls). The mean age was 13 (2-15) years. The ratio between boys and girls was 1:1.6 showing the incidence among girls to be greater. The mean duration of symptoms was 16 (0.3-96) months before the arthroscopy. Major diagnostic groups were plica syndrome (43 cases), malalignment of the patella (29 cases), osteochondritis dissecans (28 cases) and arthritis of the knee (28 cases). The accuracy of clinical diagnosis was 47% in preadolescents and 51% in adolescents. Operations were performed arthroscopically in 71 cases, by open arthrotomy in 15 and by other extra-articular operations in 39. These children were followed until no further treatment was needed. The mean follow-up time was 4 years and 6 months (20-97 months). A total of 172 (87%) patients needed no further treatment, while 27 (13%) children were rearthroscopied and a reoperation was performed on 15 of these.
1. To determine the cellular mechanisms of atrial natriuretic peptide (ANP) release from ventricular cardiomyocytes, the secretory and the cardiac effects of a phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), known to stimulate protein kinase C activity in heart cells, were studied in isolated, perfused heart preparations from 2- and 21-month-old Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. TPA was added to the perfusion fluid for 30 min at a concentration of 46 nM after removal of atrial tissue. Additionally, atrial and ventricular levels of immunoreactive ANP (IR-ANP) and ANP mRNA, the distribution of ANP within ventricles as well as the relative contribution of atria and ventricles in the release of ANP were studied. 2. Ventricular hypertrophy that gradually developed in hypertensive rats resulted in remarkable augmentation of ANP gene expression, as reflected by elevated levels of immunoreactive ANP and ANP mRNA. The total amount of IR-ANP in the ventricles of the SHR rats increased 41 fold and ANP mRNA levels 12.9 fold from the age of 2 to 21 months. At the age of 21 months, levels of IR-ANP and ANP mRNA in the ventricles of SHR rats were 5.4 fold and 3.7 fold higher, respectively, than in the normotensive WKY rats. Immunohistochemical studies demonstrated ANP granules within the hypertrophic ventricles of the old SHR rats, but not within normal ventricular tissue. 3. In isolated perfused heart preparations, the severely hypertrophied ventricular tissue of SHR rats after atrialectomy secreted more ANP into the perfusate than did the control hearts.(ABSTRACT TRUNCATED AT 250 WORDS)
We performed lateral release and proximal realignment for painful patellofemoral malalignment in 36 adolescents (40 knees), with a mean age of 14 (9-16) years. The mean follow-up was 4 (1-8) years. The subjective outcome was excellent in 20 knees, good in 13, fair in 5, and poor in 2. The mean radiographic correction of the lateral patellar shift was 75%, and of the tilting angle of the patellar 27%. There was a positive association between the realignment effect and the subjective outcome.
Realignment operations were performed on 57 knees to correct patellar malalignment in children between 1985 and 1991. Three different operative techniques were used: the lateral release, the lateral release and medial reefment, and the Roux-Goldthwait patellar tendon transposition. Roentgenographic values were measured before and after the operation by Laurin's method. The mean follow-up time was 4 years 2 months, after which 20 knees were excellent, 20 good, 11 fair, and six poor, according to Insall's criteria. The effect of the operation on pathological roentgenographic values was obvious, and the malalignment of the patella was in most cases corrected. There are differences in the improvement effected by these three techniques. The lateral release and medial reefment correct the patellar tilt most effectively, and the Roux-Goldthwait operation, the lateral patellar deviation. The lateral release seems to be the appropriate technique for mild malalignment.
Ventricular hypertrophy is characterized by augmentation of synthesis, storage, and release of atrial natriuretic peptide (ANP) from ventricular tissue, but the physiological stimulus for ANP release from ventricles is not known. We determined the effect of graded, passive myocardial stretch on ANP release in isolated, arrested, perfused heart preparations after removal of the atria in 13-20-month-old Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). By this age, ANP gene expression was increased in the hypertrophic ventricular cells of SHR, as reflected by elevated levels of immunoreactive ANP and ANP mRNA and the increased ANP secretion (SHR, 93 +/- 14 pg/ml, n = 22; WKY rats, 22 +/- 2 pg/ml, n = 20; p less than 0.001) from perfused ventricles after removal of the atria. The release of ANP from ventricles was examined at two levels of left ventricular pressure by increasing the volume of the intraventricular balloon for 10 minutes. Stretching of the ventricles produced a rapid but transient increase in ANP secretion. As left ventricular pressure rose from 0 to 14 and 26 mm Hg in WKY rats and from 0 to 13 and 27 mm Hg in SHR, increases in ANP release into the perfusate of 1.4 +/- 0.1-fold and 1.5 +/- 0.2-fold (p less than 0.05) in WKY rats and 1.1 +/- 0.1-fold and 1.6 +/- 0.2-fold (p less than 0.05) in SHR, respectively, were observed. There was a highly significant correlation between the left ventricular pressure level and the maximal concentration of ANP in the perfusate during stretching (p less than 0.001, r = 0.59, n = 42), as well as between the maximal ANP concentrations in perfusate during stretching and the ventricular weight/body weight ratios of the corresponding animals (r = 0.38, p less than 0.05, n = 42). High performance liquid chromatographic analysis revealed that the ventricles both before and during stretch primarily released the processed, active, 28-amino acid ANP-like peptide into the perfusate. These results indicate that stretching is a direct stimulus for ventricular ANP release and show that ANP is also a ventricular hormone.
Left ventricular hypertrophy is characterized by stimulation of ventricular synthesis of atrial natriuretic peptide (ANP). This study was designed to test the hypothesis that the increased ventricular ANP levels participate in the release of ANP into the circulation. Swimming was used as a physiologic model to induce ANP release from the heart, and atrial and ventricular levels of immunoreactive ANP (IR-ANP) and ANP messenger RNA (mRNA) were measured simultaneously in the spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats at rest and after swimming. IR-ANP concentration in the left ventricle of 1-year-old SHR with severe left ventricular hypertrophy was increased in association with the augmentation of ANP mRNA levels, whereas right ventricular levels of ANP were reduced in SHR compared with normotensive controls. A 30-minute exercise in hypertensive and in normotensive rats resulted in marked increases in mean arterial pressure, heart rate, plasma catecholamine levels, blood lactate levels, and plasma IR-ANP concentration. The increased ANP secretion was associated with a decrease in left (34-39%) and right (24%) ventricular concentration of IR-ANP; transmurally, this depletion of ventricular IR-ANP was greatest (28%) in the endocardial layer of the left ventricle of SHR. No significant differences were noted in total atrial and left or right auricular IR-ANP concentration between SHR and WKY rats or between the resting and swimming rats. When studied in vitro with an isolated, perfused heart preparation, the hypertrophic ventricular tissue after atrialectomy secreted more ANP into the perfusate than did control hearts; in SHR, ventricles contributed 28% of the total ANP release to perfusate, and in normotensive control rats, ventricles contributed 8%. These studies show that stimulated release of ANP is associated with depletion of endocardial left ventricular stores. The amount of ANP released in vitro and in vivo correlated with the degree of hypertrophy of the ventricle. Finally, the phorbol ester, known to increase ANP secretion from intact perfused hearts, had only a limited effect on ANP release after atrialectomy, suggesting that the secretion of ANP from ventricular cells may be mainly of the constitutive type.
1. Ventricular hypertrophy is characterized by stimulation of ventricular synthesis of atrial natriuretic peptide (ANP). To examine the role of ventricular ANP levels in the secretion of ANP into the circulation, atrial and ventricular levels of immunoreactive-ANP (IR-ANP) as well as ANP messenger RNA (mRNA), and the release of IR-ANP from isolated perfused hearts, both before and after atrialectomy, were measured simultaneously in control and minoxidil-treated Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. 2. IR-ANP levels in the ventricles of untreated, 12 month-old SHR with severe ventricular hypertrophy were increased when compared to age-matched WKY rats. Minoxidil treatment for 8 weeks in both strains resulted in a decrease in mean arterial pressure and increases in ventricular weight to body weight ratios, plasma IR-ANP concentrations (in WKY from 133 +/- 20 to 281 +/- 34 pg ml-1, P less than 0.01; in SHR from 184 +/- 38 to 339 +/- 61 pg ml-1, P less than 0.05), and in ventricular IR-ANP contents (in WKY: 53%; in SHR: 41%). A highly significant correlation was found between ventricular IR-ANP content and ventricular weight to body weight ratio (r = 0.59, P less than 0.001, n = 26). 3. When studied in vitro, in isolated perfused heart preparations, the hypertrophied ventricular tissue after atrialectomy secreted more ANP into the perfusate than ventricles of the control hearts; ventricles contributed 28%, 22%, 18% and 15% of the total ANP release to perfusate in the minoxidil-treated SHR, control SHR, minoxidil-treated WKY and control WKY, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
