What is the Role of Magnetic Resonance Imaging in the Evaluation of Total Hip Arthroplasty?

MRI has been shown to be an extremely effective instrument in the management of painful hip arthroplasty. Its superior soft tissue contrast and direct multiplanar acquisition compared to computerized tomography (CT) and radiographs allows for reproducible visualization of periacetabular osteolysis, demonstrating compression of neurovascular bundles by extracapsular synovial deposits. In addition, MRI can often elucidate etiology of neuropathy in the perioperative period and is further helpful in evaluating the soft tissue envelope, including the attachment of the hip abductors, short external rotators and iliopsoas tendon. A further advantage of MRI over CT is its lack of ionizing radiation. Most importantly, MRI can disclose intracapsular synovial deposits that precede osteoclastic resorption of bone.     

Electrocardiographical case. A case of wide complex tachycardia

A 43-year-old Chinese woman complained of a one week history of irregular rapid palpitations associated with chest discomfort and dyspnoea. Her heart rate was more than 160 beats per minute and blood pressure was 154/95 mmHg. 12-lead electrocardiogram (ECG) showed a wide complex tachycardia with a slightly irregular rhythm. Delta waves were also present. She was treated appropriately with intravenous procainamide but developed torsades de pointes secondary to prolonged QT interval. Electrophysiology study revealed atrial tachycardia with a left-sided accessory pathway which was successfully ablated.     

Outcome following radiotherapy for loco-regionally recurrent non-small cell lung cancer

Local and regional recurrence of non-small cell lung cancer is reported to occur in 13-20% of treatment failures after resection. Reported post-recurrent median survival following radiotherapy ranges from 9 to 14 months. This study examines survival following radiotherapy alone for patients with loco-regionally recurring non-small cell lung cancer after initial surgery. Fifty-five patients, receiving radiotherapy at Westmead Hospital between 1979 and 1997, were eligible for study. Data were collected retrospectively by reviewing patient records. The end-point was overall survival. Symptom control was also recorded. Prognostic factors for analysis included age, sex, original presenting stage, disease-free interval (DFI), performance status, site of recurrence, treatment intent and dose. The median overall survival was 11.5 months (95% confidence interval: 8.1-13.0). Survival following treatment with radical intent was 26 months compared to 10.5 months for patients treated with palliative intent (P = 0.025). There was no significant difference in survival for short (< or = 2 years) or long DFI, performance status, radiation dose, age, sex, site of recurrence or stage. Most patients (55%) had partial or complete resolution of symptoms. Radiotherapy results in overall post-recurrence median survival of nearly 1 year, consistent with previous published data. Radical treatment intent predicts better prognosis as a result of patient selection and higher dose. Radiotherapy is effective at palliating symptoms of this disease.     

Suprapineal recess: an alternate site for third ventriculostomy? Case report

This 30-year-old woman presented with clinical symptoms and signs of intracranial hypertension and Parinaud syndrome secondary to ventriculoperitoneal shunt dysfunction. Magnetic resonance (MR) imaging revealed gross triventricular hydrocephalus with a large suprapineal recess due to aqueductal stenosis. Using an endoscopic approach, a ventriculostomy was performed within the floor of the dilated suprapineal recess. Following this procedure the patient experienced alleviation of all her neurological symptoms and signs. Postoperative MR imaging and cerebrospinal fluid flow studies demonstrated a functioning ventriculostomy. The anatomy of the suprapineal recess and its suitability for endoscopic ventriculostomy are discussed.     

Effect of overexpressed adenylyl cyclase VI on beta 1- and beta 2-adrenoceptor responses in adult rat ventricular myocytes

1. Adenylyl cyclase VI (ACVI) is one of the most abundantly expressed beta adrenergic receptor (betaAR)-coupled cyclases responsible for cyclic AMP (cAMP) production within the mammalian myocardium. We investigated the role of ACVI in the regulation of cardiomyocyte contractility and whether it is functionally coupled with beta(1) adrenergic receptor (beta(1)AR). 2. Recombinant adenoviruses were generated for ACVI and for antisense to ACVI (AS). Adult rat ventricular myocytes were transfected with ACVI virus, AS or both (SAS). Adenovirus for green fluorescent protein (GFP) served as control. Myocyte contraction amplitudes (% shortening) and relaxation times (R50) were analysed. ACVI function was determined using cAMP assays. 3. ACVI-transfected cells demonstrated a strong 139 kDa ACVI protein band compared to controls. ACVI myocytes had higher steady-state intracellular cAMP levels than GFP myocytes when unstimulated (GFP vs ACVI=6.60+/-0.98 vs 14.2+/-2.1 fmol cAMP/viable cell, n=4, P<0.05) and in the presence of 1 microm isoprenaline or 10 microm forskolin. 4. ACVI myocytes had increased basal contraction (% shortening: GFP vs ACVI: 1.90+/-1.36 vs 3.91+/-2.29, P<0.0001) and decreased basal R50 (GFP vs ACVI: 62.6+/-24.2 ms (n=50) vs 45.0+/-17.2 ms (n=248), P<0.0001). ACVI myocyte responses were increased for forskolin (E(max): GFP=6.70+/-1.59 (n=6); ACVI=9.06+/-0.69 (n=14), P<0.01) but not isoprenaline. 5. ACVI myocyte responses were increased (E(max): GFP vs ACVI=3.16+/-0.77 vs 5.10+/-0.60, P<0.0001) to xamoterol (a partial beta(1)AR-selective agonist) under beta(2)AR blockade (+50 nm ICI 118, 551). AS decreased both control and ACVI-stimulated xamoterol responses (E(max): AS=2.59+/-1.42, SAS=1.38+/-0.5). ACVI response was not mimicked by IBMX. Conversely, response through beta(2) adrenergic receptor (beta(2)AR) was decreased in ACVI myocytes. 6. In conclusion, ACVI overexpression constitutively increases myocyte contraction amplitudes by raising cAMP levels. Native ACVI did not contribute to basal cAMP production or contraction amplitude and only to a minor extent to the forskolin response. beta(1)AR but not beta(2)AR coupling was dependent on ACVI.     

Correlation of intravesical prostatic protrusion with bladder outlet obstruction

OBJECTIVES: To determine the effect of intravesical protrusion of the prostate (IPP, graded I to III) on lower urinary tract function, by correlating it with the results of a pressure-flow study. PATIENTS AND METHODS: In a prospective study men (aged> 50 years) with lower urinary tract symptoms were initially evaluated as recommended by the International Consultation on Benign Prostatic Hyperplasia, together with the IPP and prostate volume, as measured by transabdominal ultrasonography. These variables were then correlated with the results from a pressure-flow study. RESULTS: The IPP was a statistically significant predictor (P < 0.001) of bladder outlet obstruction (BOO) compared with other variables in the initial evaluation. In all, 125 patients had significant BOO, defined as a BOO index of> 40. Of these men, 94 had grade III and 30 had grade I-II IPP. Seventy-five patients had a BOO index of < 40; 69 had grade I-II and six grade III IPP. In patients with BOO confirmed on the pressure-flow study, grade III IPP was associated with a higher BOO index than was grade I-II (P < 0.001). CONCLUSION: The IPP assessed by transabdominal ultrasonography is a better and more reliable predictor of BOO than the other variables assessed.     

Coronary artery magnetic resonance imaging: a patient-tailored approach

Coronary artery magnetic resonance imaging strategies have tended to focus on the use of a single method performed during either breath-holding or free-breathing for all patients. However, significant variations exist among patients in terms of breath-holding ability and respiratory regularity that make the use of a single technique alone not universally successful. Therefore, it is prudent to make available a number of magnetic resonance imaging methods such that an appropriate respiratory motion reduction strategy can be tailored to suit the patient's respiratory pattern and characteristics. A tailored approach that can draw on different image acquisition techniques for coronary artery imaging is presented. A decision tree is proposed to triage patients into imaging regimes with the greatest probability of success, according to the patient's ability to breath-hold or exhibit steady respiration. Methods include volume free-breathing acquisitions using navigator echoes for respiratory monitoring in the 8- to 10-min scan time range, two-dimensional spiral navigators (2- to 3-min scan time), breath-held multislice and vessel-tracking spirals (16- to 20-second scan time), and real-time imaging approaches incorporating adaptive signal averaging. The development of multiple acquisition strategies substantially improves the opportunities to generate high-quality, diagnostic images of the coronary arteries.     

灰毡毛忍冬化学成分研究V灰毡毛忍冬素F和G的结构测定

灰毡毛忍冬化学成分研究Ｖ灰毡毛忍冬素Ｆ和Ｇ的结构测定陈敏，吴威巍，沈国强，罗思齐，李惠庭（上海医药工业研究院２０００４０）灰毡毛忍冬（ＬｏｉｎｃｅｒａｍａｃｒａｎｔｈｏｉｄｅｓＨａｎｄ．－Ｍａｚｚ）系忍冬科忍冬属植物，别名大花忍冬，分布于贵州、广西、...