Avascular necrosis versus other diseases of the hip: sensitivity of MR imaging

Magnetic resonance (MR) imaging of the hip has been useful in the examination of patients for the presence of avascular necrosis (AVN). In the detection of AVN, MR imaging is more sensitive than computed tomography or nuclear scintigraphy. This study assessed the usefulness of MR imaging in the differentiation of AVN from other hip diseases. Twenty-two cases of non-AVN hip disease were matched with 23 biopsy-proved cases of AVN and ten normal controls. MR images were rated in a blinded manner by five experienced radiologists, and receiver operating characteristic (ROC) analysis was performed on the data. In the discrimination of AVN from other hip diseases or from normality, the A(z) value (the area under the ROC curve) was 98.6. With a specificity of 98%, MR imaging was 97% sensitive in the differentiation of AVN from normality, 85% sensitive in the differentiation of AVN from non-AVN disease, and 91% sensitive in the differentiation of AVN from both conditions. MR imaging may therefore help discriminate between AVN and other hip diseases.     

Angiography in the diagnosis and staging of pelvic neoplasms

The efficacy of arteriography in the staging of pelvic neoplasms was examined in 447 patients. It was found to be most useful in defining advanced neoplastic disease, improving accuracy of staging in these patients by about 18%. In patients with early pelvic neoplastic disease, arteriography reduced the number of false positives.     

Multiple percutaneous access routes to multiple calculi, calculi in caliceal diverticula, and staghorn calculi

For expeditious removal of multiple calculi from certain locations in the pyelocaliceal system, the use of multiple percutaneous entry routes is advocated. The accessibility of different regions of the pyelocaliceal system from different percutaneous entry sites was mapped out after experience with the percutaneous removal of 87 solitary and 37 multiple renal calculi. A technique allowing limited access to calculi in caliceal diverticula and hydrocalices distal to stenotic infundibula was used, along with a technique for percutaneous infundibuloplasty, which is necessary to ensure drainage of such obstructed calices or caliceal diverticula after percutaneous lithotripsy. In 34 of 37 patients with multiple or staghorn calculi, all calculi were eventually removed by these methods. The use of multiple entry routes did not increase the risk of reduced renal function. Moreover, improved drainage through the resultant multiple nephrostomy tubes and transinfundibular stents has reduced the incidence of postoperative septicemia.     

Gene expression of plasminogen activation cascade components in human term gestational tissues with labour onset

The plasminogen activation cascade is thought to play a critical role in labour-associated remodelling events, such as fetal membrane rupture and placental separation. The aim of this study was to quantify, by Northern analysis, the gene expression of urokinase plasminogen activator (UPA), urokinase receptor (UPAR) and plasminogen activator inhibitor type-2 (PAI-2) in human gestational tissues. Amnion, choriodecidua and placenta were collected from women before, during and after spontaneous-onset labour at term. The expression of UPAR mRNA was significantly (P < 0.05) increased in amnion tissue during and after labour and delivery, compared with the before-labour group. In contrast, UPAR gene expression in choriodecidua and placenta was not significantly altered in association with labour onset. PAI-2 mRNA expression was also significantly (P < 0.05) increased in amnion after labour. No statistically significant differences were observed in choriodecidua or placenta PAI-2 mRNA with labour onset. Neither was any significant effect of labour status on UPA mRNA identified in any of the tissues examined. This study is the first to describe a significant increase in UPAR and PAI-2 gene expression in human amnion tissue with labour. These data are consistent with the hypothesis that, during labour, up-regulation of UPAR expression in amnion serves to localize active UPA at the cell surface, thereby increasing proteolytic activity in fetal membranes. Increased PAI-2 in amnion after labour may provide a regulatory 'switch' to cease further proteolysis in this tissue type. In conclusion, the data obtained support the proposal that the plasminogen activation cascade contributes to the rupture of fetal membranes during active labour.      

PAROXYSMAL TACHYCARDIA IN INFANCY AND CHILDHOOD II. Paroxysmal Ventricular Tachycardia and Fibrillation

A retrospective 3–20-years follow-up study of 1 infant and 10 children with paroxysmal ventricular tachycardia (8 cases) or fibrillation (3 cases) is presented. Additional heart disease has been observed in 60% (myocarditis 3 cases, cardiomyopathy 3 cases, congenital heart disease 1 case). Symptoms of tachycardia were: palpitation, tiredness, weakness, dyspnoea, precordial and abdominal pain. Syncopes were observed in 3 cases; 1 child had no symptoms. Tachycardia of hours to days' duration have been noted in 8 patients, 7 had tachycardia of repetitive type with a-v dissociation, one continuous tachycardia without any intervening sinus beats after the onset of tachycardia and with retrograde atrial activation. The remaining 3 children had brief malignant tachycardia, i.e. stress-provoked bursts of ventricular activity occasionally converting to ventricular fibrillation causing syncope. The diagnosis of brief malignant tachycardia had to be based on exercise ECG (2 cases) or long-term ECG-monitoring by telemetry (one case). One child with cardiomyopathy had died at the time of follow-up and the 3 patients with brief malignant tachycardia had experienced repeated life-threatening attacks—one of which had to be stopped by emergency d.c. countershock. The period of attacks ceased in 5 cases within 2 years after onset, in 1 patient, 9 years elapsed between first and second attack. Preventive treatment with betablocking agents proved beneficial in the 3 children with brief malignant tachycardia.     

Autoradiographic location of β-adrenoceptor subtypes in cat colon smooth muscle

In order to localize β-adrenoceptors ¹²⁵I-(—)pindolol (IPIN) was used in binding to sections from cat colon. The binding characteristics for IPIN to β-adrenoceptors on colon sections were estimated by demonstrating reversible binding in the presence of isoprenaline and by steroselective binding to the isomers of propranolol. The binding of IPIN to both β₁-and β₂-adrenoceptors was shown by biphasic displacement curves in the presence of the selective β-adrenoceptor compounds betaxolol, ICI 118.551 and procaterol. The colon sections were found to contain proportions of β₁-adrenoceptors (30–50%) and β₂-adrenoceptors (50–70%). In the autoradiographic studies, 100% of the developed grains after exposure of IPIN to the photographic emulsion were displaced by 50 μm of isoprenaline. By microscopic counting at autoradiographic grains, 30–40% of the grains were found in the circular smooth muscle, while 60–70% of the grains were found in the longitudinal smooth muscle. A concentration of 2 nm ICI 118.551 completely displaced all grains in the circular smooth muscle and partly displaced those found in the longitudinal smooth muscle. A high concentration of ICI 118.551 (1 μm ) displaced all grains above background from the smooth muscle. It is concluded that the circular smooth muscle only contains β₂-adrenoceptors, while longitudinal smooth muscle may contain a proportion of β₁-adrenoceptors. Whether such a location of β-adrenoceptors can be related to the β₁-adrenoceptor-mediated inhibition of colon motility can not be clarified from these studies. However, it seems that β₁-adrenoceptors are located to the longitudinal smooth muscle instead of to the myenteric plexus of the colon.