bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolated optic nerve pseudotumour
Authors: Patankar Tufail , Prasad Srinivasa , Krishnan Anant , Laxminarayan Ramasharan
Published: March 2003

Isolated optic nerve involvement by the idiopathic inflammatory process is a rare finding and very few reports are available. Here a case of an isolated optic nerve inflammatory pseudotumour presenting with gradually progressive unilateral loss of vision is described. It showed dramatic response to a trial of steroids and its differential diagnoses are discussed.
Multiple calvarial haemangiomas
Authors: Corr Peter
Published: March 2003

Calvarial haemangiomas are rare benign tumours that may be suspected by their characteristic expansile ‘sunburst’ appearance. It is important to recognize them as such and to make the surgeon aware of haemorrhage after biopsy or resection.
Adenocarcinoma in an ileal duplication cyst: Ultrasound and computed tomography findings
Authors: Tew K , Soans Bk , Millar Ea
Published: March 2003

A case of adenocarcinoma in an ileal duplication cyst is presented. The pathological and radiological findings are described. A review of the literature on this rare condition is discussed.
Primary lymphoma of the breast
Authors: Watson Andrew P , Fraser Susan E
Published: March 2003

Primary lymphoma of the breast is a rare finding. Two cases and a review of the literature are presented.
Comparison of transcranial Doppler ultrasound and computed tomography angiography in symptomatic middle cerebral artery stenosis
Authors: Suwanwela Nijasri Charnnarong , Suwanwela Nitaya , Phanthumchinda Kammant
Published: March 2003

Transcranial Doppler ultrasound (TCD) and computed tomography angiography (CTA) of 10 patients with middle cerebral artery territory stroke were studied. To obtain data from patients with presumed in situ middle cerebral artery (MCA) stenosis, the study excluded patients with a known source of cardiac emboli, significant carotid stenosis and classical lacunar syndrome. As the gold standard for this study, CTA demonstrated MCA stenosis in all patients (100%), while abnormal TCDs suggesting MCA stenoses were found in only six patients (60%). The stenotic sites differed among patients with normal and abnormal TCDs. Patients with false negative TCDs were found to have more distal lesions (distal M1 or M2 segment) whereas patients with TCD abnormalities tend to have more proximal lesions as demonstrated by CTA. It is concluded that an abnormal TCD is highly suggestive of stenosis of MCA. A normal TCD, however, does not exclude such a lesion, especially in patients with distal M1 or M2 stenoses. Therefore, TCD may not be the best screening test for intracranial vascular stenotic lesion in MCA territory stroke.
Clinical and radiological features of biliary papillomatosis
Authors: Ma Kf , Lu Pp , Chau Lf , Chong Ak Ah , Lam Hs
Published: March 2003

Biliary papillomatosis is a rare disease with strong potential for malignant degeneration. Diagnosis is often not easy and most are made intraoperatively. In the present study, five patients with biliary papillomatosis admitted between 1990 and 1997 were reviewed. Their clinical presentation, radiological and biochemical findings were analysed. The aim of the study was to discern a set of characteristic features that would enable an early diagnosis. All of the five patients presented with recurrent episodes of acute cholangitis and epigastric pain with raised serum alkaline phosphatase. Imaging modalities including ultrasound, CT, endoscopic retrograde cholangiopancreatogram, MRI and magnetic resonance cholangiopancreatogram were reviewed. Salient imaging features included a dilated biliary tree with multiple ill‐defined and fuzzy filling defects or endoluminal frond‐like mass lesions. In conclusion, biliary papillomatosis is a rare but important cause of biliary obstruction with relapsing cholangitis and obstructive jaundice. With a healthy index of suspicion, the diagnosis can be reached when the above features are available.
Radiographic herald lesion of the urinary bladder: Pictorial essay
Authors: Flisak Michael E , Kalbhen Carl L , Predey Thomas A , Demos Terrence C
Published: March 2003

At cystoscopy a focal mucosal abnormality may be indicative of a pathological process extrinsic to the urinary bladder and has been termed ‘the herald lesion’. The aim of the present pictorial essay was to describe the radiographic counterpart to this cystoscopic finding. Radiographic herald lesions are shown in patients with extravesical inflammatory (Crohn’s disease, colonic diverticulitis and pelvic inflammatory disease) and neoplastic (colon carcinoma) processes, and urinary tract complications of these conditions are described and illustrated.
Colour Doppler flow imaging of focal hepatic lesions
Authors: Srivastava Deep Narayan , Mahajan Amit , Berry Manorama , Sharma Mahesh P
Published: March 2003

Fifty‐four patients with focal liver lesions were evaluated with colour Doppler flow imaging (CDFI) and CT to assess whether CDFI could be used to differentiate various types of lesions based on the flow pattern in terms of peritumoral and intratumoral blood flow. Peritumoral flow was found to be of no significance in the differential diagnosis of various liver lesions. Intratumoral flow was graded into mild, moderate or marked depending on the relative number of blood vessels demonstrated within the lesion. Marked intratumoral flow on CDFI was seen in 12.5% of primary hepatic malignancies and in infantile haemangioendothelioma, while a moderate flow pattern was seen in 56.2% of primary hepatic malignancies and in 18.7% of metastases. Mild flow was seen in 33.3% of primary malignancies; 18.7% of metastases; and 16.7% of haemangiomas. No intratumoral flow was seen in 100% of inflammatory lesions; 83.3% of haemangiomas; 62.5% of metastases; and only one hepatocellular carcinoma (5.6%). It was therefore concluded that the presence or absence of flow on CDFI is not a reliable feature for differential diagnosis of focal liver lesions when it is used alone. The flow pattern as assessed on CDFI may point to the nature of the lesion and, when used along with other morphological imaging features, can assist in diagnosis or in narrowing the list of different diagnoses in a particular clinical situation.
The superolateral approach for aspiration of total hip arthroplasties
Authors: McCurdy Wendy E , Moore Timothy E , Walker Craig W
Published: March 2003

Hip aspiration for exclusion of infection is a common procedure prior to revision arthroplasty. Some patients with total hip arthroplasties develop superomedial migration of the prosthesis, while others can have extensive heterotopic bone formation. The traditional approaches may be contraindicated due to overlying bowel or bone anterior/lateral to the prosthesis. These patients are candidates for the superolateral approach. With the patient supine marks are made on the skin at (i) the greater trochanter and (ii) a superior site that aligns with the neck of the prosthesis and soft‐tissue window. The needle enters the lateral skin parallel to the table top. Usually only one pass is necessary.
Analysis of intracranial mass lesions using proton magnetic resonance spectroscopy at 1.0 T: Pictorial essay
Authors: Birchall Daniel , Hua Jianmin , Khangure Makhan , Maddren Leonie , Song Swithin
Published: March 2003

Proton MR spectroscopy has been used to characterize the spectroscopic profiles of a wide variety of neurological disease processes. In particular, the spectroscopic characteristics of a range of focal intracranial mass lesions have been described. The use of proton MR spectroscopy has until recently been restricted to major research centres with high‐field MR scanners. The spectroscopic findings in a number of illustrative cases imaged at Royal Perth Hospital using a 1‐T scanner are described here. The cases illustrated in the present paper confirm the clinical utility of proton MR spectroscopy as a supplement to conventional MR in routine radiological practice.
Computed tomography features of small bowel volvulus
Authors: Loh Y Han , Dunn Graham D
Published: March 2003

A case of small bowel volvulus in an adult is presented. The established CT signs of small bowel volvulus are discussed. These include an abnormal orientation of the superior mesenteric artery to the superior mesenteric vein; the whirl sign, the triangle sign and the beak sign.
Hereditary haemorrhagic telangiectasia simulating biliary tree obstruction secondary to malignant porta hepatis lymphadenopathy
Authors: Robertson Alisdair S , Mouratidis Bill , Guduguntla Mureli
Published: March 2003

Hereditary telangiectasis is an uncommon condition and is thus not usually considered in the differential diagnosis of porta hepatis lymphadenopathy causing biliary tree obstruction. The present case illustrates a patient in whom tortuous vessels in the porta hepatis simulated masses on delayed contrast‐enhanced CT with subsequent referral for biopsy.
Pancreatic head melanoma producing obstructive jaundice: Magnetic resonance characteristics aiding differentiation from adenocarcinoma
Authors: Solomons Gregory , Gibson Robert N , Tello Richard J
Published: March 2003

A case is reported of malignant melanoma presenting as a mass in the head of the pancreas producing obstructive jaundice. On MR imaging the mass displayed signal characteristics not typical of adenocarcinoma but instead exhibited a low signal on T2‐weighted images and early phase dynamic enhancement, the combination of which should suggest the possibility of melanoma.
An approach to demonstrating cost‐effectiveness of diagnostic imaging modalities in Australia illustrated by positron emission tomography
Authors: Miles Ken A
Published: March 2003

The aim of this study was to develop a framework in which the cost‐effectiveness of new imaging technologies could be evaluated using data from other countries, while assessing the impact that any differences between the study populations and Australia may have upon the results. Publications reporting the cost‐effectiveness or therapeutic impact of positron emission tomography (PET) were re‐worked using Australian cost structures. PET was assigned a cost of $950. The effects of potential differences between the populations studied and the Australian population were evaluated by applying sensitivity analysis to those publications that describe decision tree methodology. The parameters included in the sensitivity analysis were disease prevalence and specificity of PET. The Australian cost savings per patient examined by PET were $505.50–$912.41 for investigation of solitary pulmonary nodules, $34.65–$360.03 for lung cancer staging, $550.08 for axillary staging of breast cancer, $230.75–$2301.27 for assessment of recurrent colorectal cancer and $300.24–$2069.65 for assessment of myocardial viability. Significant differences in disease prevalence and PET specificity could occur while the cost‐effectiveness of PET was preserved. Decision tree sensitivity analysis can demonstrate the cost‐effectiveness of diagnostic imaging modalities in Australia and provides indications that PET is cost‐effective for a range of clinical indications.
Australian high‐dose‐rate brachytherapy protocols for gynaecological malignancy
Authors: MacLeod Craig , Cheuk Robyn , Dally Mike , Fowler Allan , Gauden Stan , Leung Sam , Milross Chris , Narayan Kailash , Stevens Mark , Thornton Deborah , Carruthers Scott , Jeal Peter
Published: March 2003

There is no consensus over the optimal dose fractionation schedules for high‐dose‐rate (HDR) brachytherapy used for gynaecological malignancy. In Australian public hospital departments of radiation oncology, HDR brachytherapy for gynaecological cancer is being more commonly used. A survey of public departments that are using this technology, or that plan to introduce this technology, was performed. Their current protocols are presented. In general, protocols are similar biologically; however, the practical aspects such as the number of fractions given do vary and may reflect resource restrictions or, alternatively, differences in interpretations of the literature and of the best protocols by clinicians.
Tuberculous biliary strictures: Uncommon cause of obstructive jaundice
Authors: Prasad Akhilandeswari , Pandey Kamala Kant
Published: March 2003

Tuberculous biliary stricture is a very rare cause of obstructive jaundice. A case of a man who had had pulmonary tuberculosis 20 years ago is reported. He now presented with obstructive jaundice due to multiple strictures just below the confluence of the hepatic ducts and in the right hepatic duct. At surgery these turned out to be tuberculous in origin. There was also tuberculous involvement of the gall bladder and cystic duct. The commonest differential diagnosis in such cases is cholangiocarcinoma (as in the present case). Imaging helps in defining the extent of bile duct obstruction. Suspicion of the disease and establishing a tissue diagnosis is very important in treating this potentially curable condition, especially with the worldwide resurgence of tuberculosis.
‘Indolent’ plasmacytoma
Authors: Stewart David , Price Pat
Published: March 2003

A patient presented with lethargy, nausea and diarrhoea and had a 10‐year history of neurological symptoms in his legs. He was found to have renal failure. Investigations demonstrated a longstanding plasmacytoma of the sacrum and progression to myeloma. Such an indolent course for plasmacytoma is rare. A review of the clinical case and management of solid plasmacytomas is presented.
A safe percutaneous method to recanalize sharp venous occlusions that resist the passage of guidewires
Authors: Cameron David C
Published: March 2003

It is occasionally necessary to cross a sharp venous occlusion (a thin web of tissue without a lumen) and sometimes it is not possible to cross the stricture with a wire, so puncturing it with a sheathed needle is then required to enable stenting. Other methods have been reviewed; however, we think this balloon technique makes it a safer procedure.
Treatment of iatrogenic femoral artery false aneurysms with ultrasound‐guided thrombin injection
Authors: Ramsay Duncan W , Marshall Martin
Published: March 2003

The aim of this paper is to review our results of treating iatrogenic pseudoaneurysms of the femoral artery with ultrasound‐guided thrombin injection. A retrospective review was carried out of all patients referred for this procedure over a 1‐year period from December 1999 to December 2000. Forty‐five patients were referred and, of these, 44 were eligible for this treatment, with 300–2500 units of thrombin being injected directly into the false aneurysms under ultrasound guidance. The procedure was well tolerated with no patients requiring sedation or analgesia. There was a primary success rate of 95%, although in four of the patients, there was recurrence on repeat ultrasound performed 2–5 days post‐procedure and a second injection of thrombin was required for permanent thrombosis to be achieved. No complications relating to the procedure occurred. Our results confirm increasing evidence in the published research that thrombin injection of femoral artery false aneurysms is a safe and effective treatment.
Intensity‐modulated radiation therapy: First reported treatment in Australasia
Authors: Corry June , Hope Geoff , Cramb Jim , Smylie Jo , Joon Daryl Lim , Towns Sam , Archer Paul , Henkul Zoltan , Wills Julie
Published: March 2003

Intensity‐modulated radiation therapy (IMRT) is an exciting new advance in the practice of radiation oncology. It is the use of non‐uniform radiation beams to achieve conformal dose distributions. As a result of the high initial capital costs and the time and complexity of planning, IMRT is not yet a widely available clinical treatment option. We describe the process involved in applying this new technology to a case of locally advanced nasopharyngeal cancer.
What happens after a lung scan? Management and outcome of patients in a regional hospital
Authors: Chan Wai‐Ling , McLean Richard , Carolan Martin G
Published: March 2003

Pulmonary embolism (PE) remains a common preventable cause of death in hospitalized patients. The purpose of this study is to examine the in‐hospital management, complications of treatment and clinical outcomes of inpatients undergoing lung scintigraphy for the diagnosis of PE in a regional hospital. Two hundred consecutive inpatients with suspected PE were enrolled. The results of lung scans, stratified according to the probability of pulmonary embolism, were correlated with anticoagulation status, discharge diagnosis, haemorrhagic complications and clinical outcome at 6 months. The use of complementary imaging investigations was also determined. Other imaging was performed infrequently (Doppler ultrasound in 18% of patients, CT pulmonary angiography (CT‐PA) in 0.5% and conventional pulmonary angiography in 4% of patients). Long‐term anticoagulation was initiated in 66 patients (33%), including 10 with intermediate probability lung scans (IPLS) who had no further investigations. Major haemorrhage occurred in 14% of all long‐term anticoagulated patients followed up. The recognized recurrence rate was very low (3%) and there was no documented mortality from PE. Most patients with suspected PE are treated on the basis of the lung scan result without further tests. However, other imaging (especially CT‐PA and conventional pulmonary angiography) should be performed prior to anticoagulation in patients with IPLS in whom the diagnosis is in doubt. Standard anticoagulation for 6 months appears to be effective for PE, and the recurrence rate is low. However, it has a significant risk of major haemorrhagic complications.
Mesenchymal hamartoma of the chest wall in infants: Report of three cases and literature review
Authors: Lisle DA , Ault DJ , Earwaker JW
Published: March 2003

Mesenchymal hamartoma of the chest wall in infants is a rare abnormality. We present a report of three cases and a brief review of the literature, emphasizing the role of the radiologist in diagnosis and management.
Midgut volvulus in an adult
Authors: Puvaneswary M , Rajaratnam S
Published: March 2003

We report a case of duodenal malrotation that presented in adulthood as midgut volvulus. On colour Doppler ultrasound, findings of a clockwise rotation of the superior mesenteric vein around the superior mesenteric artery (whirlpool sign) and a distinctive ‘whirl’‐like pattern resulting from an encircling of loops of the bowel around the SMA on CT is diagnostic of midgut volvulus.
METABOLIC AND FUNCTIONAL EFFECTS OF CARBACHOL AND ISCHAEMIC PRECONDITIONING IN RAT ISOLATED HEART
Authors: Pisarenko Oleg I , Shulzhenko Valentine S , Studneva Irina M
Published: March 2003

1. Metabolic and functional effects of ischaemic preconditioning (IP), pretreatment with carbachol (Ch) and combined interventions were studied in rat isolated working hearts subjected to 20 min global ischaemia (37°C) and 40 min reperfusion. Prior to the ischaemic period, hearts were either perfused according to Langendorff (control group), ischaemically preconditioned by 5 min global ischaemia and 5 min reperfusion (IP group), perfused with 0.1 μmol/L Ch for 5 min and then with Ch‐free Krebs’–Henseleit buffer for 5 min (Ch group) or perfused with 0.1 μmol/L Ch for 5 min and then subjected to IP (Ch + IP group).

2. Although Ch exerted slight negative chronotropic and inotropic effects during pre‐ischaemic Langendorff perfusion, it did not affect myocardial contents of ATP and phosphocreatine (PCr) prior to sustained ischaemia. At the end of final reperfusion, the IP and Ch groups showed similar recovery of aortic output (67.5±5.0 and 56.8±5.4%, respectively), cardiac output (65.4±5.4 and 63.5±5.7%, respectively) and stroke volume (73.4±7.5 and 67.0±6.7%, respectively) expressed as a percentage of steady state values. These indices were higher than those in the control group (42.8±4.7, 53.8±4.3 and 56.1±5.6%, respectively; P < 0.05). The Ch + IP group exhibited complete recovery of all indices of pump function, including cardiac work, expressed as the cardiac output–mean aortic pressure (CO‐MAP) product.

3. There were no differences in ATP recovery between the groups after reperfusion: the ATP content was, on average, 73.1±3.5% of the initial ATP content. However, all treated groups had enhanced PCr recovery and better preservation of total creatine (ΣCr = PCr + Cr), an index of cell membrane integrity, than control. Metabolic efficacy of the pre‐ischaemic interventions can be ranked as follows: IP ≤ Ch < Ch + IP. In all groups, myocardial content of ΣCr was positively correlated with percentage recovery of the CO‐MAP product at the end of reperfusion (r = 0.79, P < 0.05).

4. The results demonstrate that Ch treatment combined with IP provides significantly greater postischaemic myocardial salvage. The similarity of the metabolic and functional effects of Ch treatment and IP strongly suggests muscarinic M2 acetylcholine receptor involvement in acute adaptation of rat heart to ischaemia/reperfusion stress.
OESTROGEN AND TRANSPLANT VASCULAR DISEASE
Authors: Saito Satoshi , Foegh Marie L , Lou Hong , Aras Rohit , Ramwell Peter W
Published: March 2003

1. The aetiology of chronic rejection is clearly multifactorial and relates to both immunological and non‐immunological factors.

2. Our studies suggest that the insulin‐like growth factor (IGF)‐I ligand and receptor genes are rate limiting in smooth muscle proliferation in the development of transplant arteriosclerosis.

3. Suppressing growth factor ligand or receptor expression could be effective strategies for the prevention or treatment of transplant arteriosclerosis.

4. We consistently find chronic oestradiol treatment of transplant recipients inhibits arteriosclerosis by attenuating both IGF‐I expression and the immune response, particularly major histocompatibility complex class II expression.

5. Thus, a cell‐ or tissue‐specific oestrogen with minimal feminizing properties may be an ideal drug for prevention of one of the major causes of loss of transplant function.
EFFECTS OF BDF 9148 ON THE ACTION POTENTIALS AND CONTRACTIONS OF LEFT VENTRICLES FROM NORMO‐ AND HYPERTENSIVE RATS
Authors: Nand Vinita , Doggrell Sheila A
Published: March 2003

1. The aim of the present study was to test the hypothesis that responses to BDF 9148, which prolongs the opening of sodium channels, are reduced in the spontaneously hypertensive rat (SHR) left ventricle in the presence of hypertrophy and failure.

2. We studied the effects of BDF 9148 on the action potentials and contractions of left ventricles from 5‐week‐old prehypertensive, 14‐week‐old hypertensive, 6‐ and 12‐month‐old hypertension‐associated hypertrophy and 18‐month‐old hypertension‐induced heart failure SHR and age‐matched Wistar‐Kyoto normotensive (WKY) rats.

3. Action potentials and left ventricular contractions did not alter in the early stages of hypertension (14‐week‐old SHR). The diastolic membrane potential did not change with hypertension‐associated hypertrophy, but there was a reduction in amplitude and a prolongation of action potentials in the left ventricles of 6–18‐month‐old SHR. Cardiac stimulation responses and maximum contractions to 10−6 mol/L isoprenaline were reduced at 6 months, whereas the maximum contractions to 10−2 mol/L CaCl2 were only reduced in left ventricles of 18‐month‐old SHR.

4. At concentrations ranging from 10−7 to 3 × 10−6 mol/L, BDF 9148 increased the amplitude and prolonged the duration of action potentials and augmented the force in WKY rat left ventricles. The augmenting effects of BDF 9148 at 3 × 10−6 mol/L were smaller than at 10−6 mol/L, possibly because the high concentration of BDF 9148 was also blocking calcium channels. Similar effects were observed with BDF 9148 in the early stages of hypertension (14‐week‐old SHR).

5. In the presence of persistent hypertension‐associated hypertrophy of the SHR left ventricle at ≥ 6 months, the effects of BDF 9148 on action potentials and contractions were significantly reduced to a small extent. This impairment of the response to BDF 9148 may reflect the reduced contractility of the SHR left ventricle and/or it may indicate that the response to the opening of sodium channels is altered from 6 months of age.

6. In summary, most of the response to BDF 9148 is maintained in the presence of hypertrophy and failure. Thus, BDF 9148 may have some potential for the treatment of heart failure.
EFFECTS OF APOLIPOPROTEIN A GENE POLYMORPHISMS ON LIPOPROTEIN (a) CONCENTRATIONS IN JAPANESE
Authors: Park Hyun‐Young , Nabika Toru , Notsu Yoshitomo , Kobayashi Shotai , Masuda Junichi
Published: March 2003

1. Elevated plasma lipoprotein (a) (Lp(a)) concentrations have been correlated with an increased risk of premature cardiovascular disease. The plasma Lp(a) concentration is quantitatively heritable and the apolipoprotein (Apo) A gene is known as a major locus‐determining Lp(a) concentration.

2. The aim of the present study was to evaluate the genetic effect of polymorphisms in the 5′‐untranslated region (UTR) of the ApoA gene on plasma concentrations of Lp(a).

3. We analysed two sequence variations in the 5′‐UTR, a pentanucleotide repeat (PNR) polymorphism and haplotypes composed of three single base substitutions, in 325 Japanese subjects. The ApoA size polymorphism was also analysed by western blotting.

4. The plasma Lp(a) concentration was inversely correlated with the size of the ApoA molecule. Both PNR and the haplotype polymorphisms had significant effects on serum Lp(a) concentrations (P = 0.001 and 0.004, respectively) when the effects were evaluated by ANCOVA using the ApoA size polymorphism as a covariate.

5. When a stratified subpopulation with a larger ApoA size was analysed, both variations influenced or tended to influence the serum Lp(a) concentration, confirming the results of the ANCOVA.

6. Pentanucleotide repeat showed a tight linkage disequilibrium with the haplotypes. This disequilibrium may account for the apparent effects of PNR on Lp(a) concentrations.
EFFECTS OF NALOXONE, GLYCYRRHIZIC ACID, DEXAMETHASONE AND DEOXYCORTICOSTERONE IN REPETITIVE STRESS
Authors: Ainsah O , Nabishah Bm , Osman Cb , Khalid Bak
Published: March 2003

1. The present study examined the effect of naloxone (NAL), glycyrrhizic acid (GCA), deoxycorticosterone (DOC) and dexamethasone (DEX) on daily repeated 2 h chronic restrained stress (RS) on the locomotor activity (LA) of rats tested in the open field arena to elucidate the possible roles of opioids, glucocorticoids and mineralocorticoids in response to stress.

2. Intact and adrenalectomized (ADX) rats were either injected with 0.1 mL of NAL (0.32 μg/100 g BW), 2.4 mg/kg DOC or 120 μg/kg DEX or had 1.0 mg/mL GCA dissolved in their drinking water or normal saline (for the ADX group) dissolved in their drinking water.

3. In intact groups, treatment with NAL completely blocked the stress response and treatment with GCA, DOC and DEX partially prevented the stress response. Adaptation occurred on either days 4, 5, 6 or 7 for intact rats treated with DEX, DOC, GCA or control rats, respectively. All ADX control rats died following the first 2 h RS. Adrenalectomized rats treated with DEX or DOC adapted later compared with intact rats, while rats given either GCA or NAL were unable to block or adapt to chronic RS.

4. These findings demonstrate that the stress response is primarily mediated by endogenous opioids, in that it is blocked by NAL. Both mineralocorticoids and glucocorticoids, which can act centrally to inhibit endorphins, partially blocked the stress response. The effect of GCA in intact rats was similar to that of both DEX and DOC in intact rats. Adrenalectomized rats treated with GCA (despite their lack of endogenous corticosterone) showed a stress response that was significantly different from the other ADX groups, implying that GCA had effects independent of endogenous corticosterone.
EVOLUTION OF HAEMOGLOBIN FUNCTION: MOLECULAR ADAPTATIONS TO ENVIRONMENT
Authors: Wells Rufus Mg
Published: March 2003

1. Nearly 1000 mutations have been described for human haemoglobin (Hb), many of which result in subtle changes to the oxygen transport system. Similar changes have occurred over the course of animal evolution resulting in a diversity of functional attributes which appear to correlate the availability of oxygen in the environment with metabolic demand.

2. At an early stage in evolution, worm‐like animals had large, polymeric aggregations of Hb subunits circulating through primitive circulatory systems and some possessed monomeric Hb in blood cells functioning as an oxygen store.

3. The circulating vertebrate red blood cell provides an environment allowing haem units to interact among themselves and with various organic phosphates to allow a responsive and highly regulated system of gas transport. During metazoan evolution the burden of physiological regulation has shifted from the cells to organ systems, as endothermy and aerial breathing permit a relatively constant environment.

4. An understanding of the adaptive possibilities of Hb has helped us to understand the ontogeny of oxygen transport and to interpret recently described functional properties of human embryonic haemoglobins.
HYPERLIPIDAEMIA AND THE PROGRESSION OF NEPHROPATHY IN OLETF RATS: EFFECT OF ANGIOTENSIN‐CONVERTING ENZYME INHIBITOR, ENALAPRIL
Authors: Sugimoto Koh‐ichi , Tsuruoka Shuichi , Fujimura Akio
Published: March 2003

1. The influence of angiotensin‐converting enzyme (ACE) inhibitor is investigated in enalapril on renal function in Otsuka Long‐Evans Tokushima Fatty (OLETF) rats, an animal model of spontaneously non‐insulin‐dependent diabetes (NIDDM).

2. Enalapril (5 mg/kg) or vehicle was administered once daily by gastric gavage to 22‐week‐old male OLETF rats for 32 weeks. Blood pressure, albuminuria, creatinine clearance, plasma glucose, serum insulin and lipids were determined before and during the treatment. Renal haemodynamics was examined at the end of the treatment.

3. Enalapril lowered blood pressure mildly but significantly. In the vehicle‐treated rats, urinary albumin excretion increased from 0.75±0.16 mg/mg creatinine (Cr) to 8.65±0.78 mg/mg Cr. Enalapril significantly blunted the development of albuminuria from 0.66±0.12 mg/mg Cr to 5.19±0.67 mg/mg Cr (P < 0.008) without significant influence on creatinine clearances. Enalapril also significantly blunted the rise in serum cholesterol and triglyceride prior to the development of massive albuminuria. Enalapril did not affect bodyweight, plasma glucose or insulin levels. Renal haemodynamics assessed by inulin and p‐aminohippuric acid clearances were similar in both groups at the end of the treatment.

4. These results reconfirmed that the ACE inhibitor has protective effects on nephropathy in NIDDM. Massive albuminuria was preceded by increase in serum lipids in OLETF rats, which supports the view that hyperlipidaemia exacerbates glomerular injury in chronic renal disease. Enalapril attenuated the rise in serum lipids, suggesting that the beneficial effects of the compound on renal injury in OLETF rats might also be mediated through the action of affecting serum lipids.
CHARACTERIZATION OF NITRIC OXIDE‐ AND PROSTAGLANDIN‐INDEPENDENT RELAXATION IN RESPONSE TO ACETYLCHOLINE IN RABBIT RENAL ARTERY
Authors: Kagota SATOMI , Yamaguchi YU , Nakamura KAZUKI , Kunitomo MASARU
Published: March 2003

1. We investigated the characterization of acetylcholine (ACh)‐induced NG‐nitro‐
L‐arginine methyl ester (
L‐NAME)‐ and indomethacin (IND)‐resistant relaxations, which can be mediated by endothelium‐derived hyperpolarizing factor (EDHF), in rabbit renal arterial rings.

2. The relaxations were inhibited by SKF 525A, a cytochrome P450 inhibitor, but were not affected by other inhibitors, namely clotrimazole, 17‐octadecynoic acid and α‐naphthoflavone. Furthermore, 11,12‐epoxyeicosatrienoic acid, a cytochrome P450 metabolite, did not relax arterial rings.

3. Arterial relaxations were significantly attenuated by charybdotoxin and iberiotoxin, but not by apamin, all K+ channel blockers.

4. In a sandwich bioassay experiment, ACh‐induced L‐NAME‐ and IND‐resistant relaxations were not transferred to the detector site.

5. Relaxations were also significantly attenuated by 1‐heptanol and 18α‐glycyrrhetinic acid, gap junctional coupling inhibitors.

6. These results indicate that, in the rabbit renal artery, L‐NAME‐ and IND‐resistant relaxations are mediated by factors other than cytochrome P450‐derived arachidonic acid metabolites, which may be able to diffuse into the lumen but be partly transferred via myoendothelial gap junctions to adjacent vascular smooth muscle cells and relax muscles by opening high‐conductance Ca2+‐activated K+ channels.
MYOCARDIAL PROTECTION DURING CARDIAC SURGERY FROM THE VIEWPOINT OF CORONARY ENDOTHELIAL FUNCTION
Authors: He GUO‐WEI
Published: March 2003

1. During cardiac surgery, the heart is arrested and subject to ischaemia–reperfusion injury.

2. To protect the heart, cardioplegia is usually used to initially stop and then maintain the still condition of the heart, which not only facilitates the precise operation but, more importantly, minimizes the energy consumption of the heart during this period.

3. The ischaemia–reperfusion injury may involve both myocytes and coronary endothelium–smooth muscle and, therefore, the protection of the heart should also involve these two aspects.

4. Injury to the heart involves: (i) ischaemia–reperfusion injury to the myocytes and coronary circulation; and (ii) possible injury to the coronary circulation by cardioplegia due to its hyperkalaemic components.

5. Injury to the coronary circulation may involve both endothelium‐derived nitric oxide (EDNO) and endothelium‐derived hyperpolarizing factor (EDHF) mechanisms. The EDNO mechanism is susceptible to ischaemia–reperfusion, whereas the EDHF mechanism may be altered by hyperkalaemic cardioplegia.

6. To further protect the heart, supplemental therapy for EDNO and optimizing the components of cardioplegia to restore the EDHF mechanism may be important.
HETEROGENEITY OF VASCULAR SMOOTH MUSCLE α‐ADRENOCEPTORS IN CANINE BLOOD VESSELS
Authors: Kwan DAVID CHIU‐YIN
Published: March 2003

1. For the past decade, using radioligand binding, contractility and immunohistochemical techniques, we have been characterizing vascular smooth muscle (VSM) adrenoceptors in four functionally different canine blood vessels, namely the dog aorta (DAO), dog mesenteric artery (DMA), dog mesenteric vein (DMV) and dog saphenous vein (DSV).

2. This communication briefly reviews our findings (with a special emphasis on α‐adrenoceptor subtypes), which showed that none of the four canine vessels showed the same complement of α‐adrenoceptor subtypes.

3. All four vessels elicited α1‐adrenoceptor contractile responses (antagonized by prazosin), but α2‐adrenoceptor responses (sensitive to rauwolscine), were found only in DMV and DSV.

4. Pharmacological characterization using α1‐adrenoceptor subtype‐selective antagonists showed that DAO contains mainly α1B‐adrenoceptors (some α1D‐adrenoceptors) and DMA has primarily α1A/1L‐adrenoceptors. α1‐Adrenoceptors in DMV are primarily of the α1D subtype, but either a new or unusual α1‐adrenoceptor subtype was revealed in the DSV.
PRO‐ AND ANTI‐ARRHYTHMIC EFFECTS OF A κ OPIOID RECEPTOR AGONIST: A MODEL FOR THE BIPHASIC ACTION OF A LOCAL HORMONE IN THE HEART
Authors: Yu XIAOCHUN , Zhang WEIMIN , Bian JINSONG , Wong TAK MING
Published: March 2003

1. The effects of κ opioid receptor stimulation on cardiac rhythm and the underlying signal pathways were investigated in the rat.

2. Stimulation of κ opioid receptors with 40–50 μmol/L U50 488H, a selective κ opioid receptor agonist, induced dysrhythmias and increased inositol 1,4,5‐trisphosphate (IP3) production in rat isolated, perfused heart. The pro‐arrhythmic effects of U50 488H were abolished by 5 μmol/L nor‐ binaltorphimine (nor‐BNI), a specific κ opioid receptor antagonist.

3. The effect of U50 488H on cardiac dysrhythmia and IP3 production were abolished by 1 mmol/L neomycin and streptomycin, phospholipase C (PLC) inhibitors.

4. At 1 μmol/L, U50 488H, which itself has no effect on cardiac rhythm and IP3 production, significantly attenuated the potentiating effect of 1 μmol/L noradrenaline (NA) on dysrhythmias, which were induced by low flow in the isolated heart. The effects of U50 488H were abolished by 1 μmol/L nor‐BNI. Cytosolic cAMP production was augmented by 1 μmol/L NA and this was significantly attenuated by 1 μmol/L U50 488H.

5. At 1 μmol/L, U50 488H also reduced [Ca2+]i oscillations induced by 0.5 μmol/L NA and 0.5 μmol/L forskolin, an activator of adenylate cyclase (AC).

6. In conclusion, U50 488H exerted pro‐ and anti‐arrhythmic actions at high and lower concentrations, respectively. The former effect was mediated via the PLC/IP3 pathway, while the latter was mediated via the AC/cAMP pathway.
USE OF MURINE MUTANTS TO STUDY GLYCINE RECEPTOR FUNCTION
Authors: Callister Rj , Schofield Pr , Sah P
Published: March 2003

1. The accompanying articles in this symposium describe several different approaches used to examine the function of glycine and GABA receptors, including pharmacology and neurochemistry, permeability and agonist‐binding approaches, the use of mutated recombinant receptors and monoclonal antibody staining to examine receptor distribution on neurons.

2. The present review focuses on the use of another, quite different, approach: the use of murine mutants, spasmodic and spastic, to study the function of native glycine receptors at synaptic connections within the central nervous system.
BUILDING NEW FUNCTION INTO GLYCINE RECEPTORS: A STRUCTURAL MODEL FOR THE ACTIVATION OF THE GLYCINE‐GATED CHLORIDE CHANNEL
Authors: Lynch Joseph W , Han Nian‐lin R , Schofield Peter R
Published: March 2003

1. The glycine receptor chloride channel mediates inhibitory neurotransmission and is a member of the ligand‐gated ion channel superfamily, which includes the nicotinic acetylcholine receptor channel.

2. Activation of these channels involves a movement of the pore‐lining second membrane‐spanning domain with respect to the remainder of the protein.

3. The present review considers the evidence that the loops that connect this domain with the rest of the protein act as crucial components of the channel activation mechanism.
PROLONGED HYPOXIC STRESS INCREASES ADRENAL CHOLESTEROL RESERVE IN RATS WITHOUT CAUSING ADRENAL HYPERTROPHY
Authors: Cheng Behling , Abraham Susamma , Thakkar Jitendra , Kowal Jerome
Published: March 2003

1. It is known that, in rats, hypoxia stimulates adrenal steroidogenesis, but our understanding of the hypoxic effect on the glandular parameters remains incomplete.

2. Adrenals were collected and analysed from rats that had been exposed to hypoxic conditions for 3 weeks.

3. The results reveal increased adrenal concentrations of corticosterone, free cholesterol and total cholesterol without a change in glandular weight and protein concentration. The increased total cholesterol is primarily associated with enriched cholesteryl adrenate (CE22 : 4), cholesteryl arachidonate (CE20 : 4) and cholesteryl oleate (CE18 : 1).
RENAL ARTERIOLAR CONTRACTILE RESPONSES TO ANGIOTENSIN II IN RATS WITH POORLY CONTROLLED DIABETES MELLITUS
Authors: Carmines Pamela K , Ohishi Kazuhisa
Published: March 2003

1. Experiments were performed to test the hypothesis that renal arteriolar responses to angiotensin (Ang)II are altered in insulin‐dependent diabetes mellitus.

2. Male Sprague‐Dawley rats were treated with streptozotocin (STZ; 65 mg/kg, i.v) or 0.9% NaCl vehicle (Sham). Partial insulin replacement maintained blood glucose levels at 422±6 mg/dL (STZ rats) for the ensuing 2 week period (86±4 mg/dL in Sham rats). The in vitro blood‐perfused juxtamedullary nephron technique was used to study renal arteriolar diameter responses to exogenous AngII or K+‐induced membrane depolarization.

3. Baseline afferent arteriolar diameter did not differ between kidneys harvested from Sham and STZ rats; however, constrictor responses to AngII were accentuated in kidneys from diabetic rats. During exposure to 10 nmol/L AngII, afferent diameter decreased by 37±5 and 18±4% in STZ and Sham kidneys, respectively. Efferent arterioles from Sham and STZ rats did not differ with regard to either baseline diameter or AngII responsiveness.

4. In experiments assessing afferent arteriolar responsiveness to membrane depolarization, 40 mmol/L K+ decreased lumen diameter by 73±11% in kidneys from Sham rats; however, the same depolarizing stimulus only reduced afferent diameter by 28±7% in STZ kidneys.

5. We conclude that afferent (but not efferent) arteriolar AngII responsiveness is increased during the early stages of poorly controlled diabetes mellitus in the rat. The exaggerated afferent arteriolar responsiveness to AngII occurs despite reduced sensitivity to membrane depolarization, suggesting that the emergence of alternative signalling processes or alterations in vasoactive modulator influences may underlie this phenomenon.
SIMVASTATIN INHIBITS CARDIAC HYPERTROPHY AND ANGIOTENSIN‐CONVERTING ENZYME ACTIVITY IN RATS WITH AORTIC STENOSIS
Authors: Luo Jian‐Dong , Zhang Wei‐Wen , Zhang Gui‐Ping , Guan Jin‐Xia , Chen Xiu
Published: March 2003

1. In the present study, we tested the hypothesis that long‐term administration of the hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase inhibitor simvastatin may regress hypertrophy and the possible effect of simvastatin on angiotensin‐converting enzyme (ACE) activity in rats with pressure‐overload cardiac hypertrophy.

2. Pressure‐overload left ventricular hypertrophy (LVH) of rats was induced by part coarctation of the abdominal aorta; a sham‐operated group served as the control. Six weeks after operation, animals were divided into three groups and an 8 week treatment period was insitgated as follows: (i) the simvastatin treatment group received simvastatin at 3.6 mg/kg per day, p.o.; (ii) the ACE inhibitor group received captopril at 50 mg/kg per day, p.o.; and (iii) the LVH control group received no drug treatment.

3. At the end of the treatment period, left ventricular systolic pressure (LVSP) and left ventricular end‐diastolic pressure (LVEDP) were monitored in vivo. Diastolic pressure–volume relationships were evaluated in a Langendorff preparation with a balloon‐in‐left ventricle (LV) heart. Myocyte cell width was measured. Angiotensin‐converting enzyme activity and angiotensin (Ang)II and hydroxyproline contents of the LV were determined.

4. At the end of the experiments, LVH was established in the LVH control group by increases in LV weight, LV weight/bodyweight ratio, LV weight/right ventricle weight ratio, LV myocyte cell width, LVSP and LVEDP by 40, 26, 19, 61, 56 and 59%, respectively (all P < 0.01), compared with the sham‐operated group. In the simvastatin‐treated and ACE inhibitor groups all these parameters were significantly reduced compared with sham‐operated controls. In the LVH control group, ACE activity and AngII and hydroxyproline contents of LV tissue increased by 180, 123 and 70, respectively (all P < 0.01), compared with the sham‐operated group. Compared with the LVH group, in the simvastatin‐treated and ACE inhibitor groups ACE activity was reduced by 36 (P < 0.05) and 48% (P < 0.01), respectively, AngII content was reduced by 11 (P < 0.05) and 43% (P < 0.01), respectively, and hydroxyproline content was reduced by 23 (P < 0.01) and 10% (P < 0.05), respectively.

5. For the first time, the results of the present study demonstrate that simvastatin significantly reduces LVH, cardiac tissue ACE activity and improves LV performance in pressure‐ overloaded rats. Because, compared with captopril, simvastatin is more potent in its reduction of LVH and less potent in its inhibition of ACE activity, the mechanism of its antihypertrophic action, in addition to ACE inhibition, may involve inhibition of the mevalonic acid pathway, the main target of action of statins. Thus, HMG‐CoA reductase inhibitors may be beneficial for the clinical treatment of cardiac hypertrophy.
SUPRANORMAL NATRIURETIC RESPONSE TO VOLUME EXPANSION IN VAGOTOMIZED AND RENAL‐DENERVATED RATS
Authors: Rodríguez‐Martínez Manuel , Brito‐Orta Dolores
Published: March 2003

1. To investigate the participation of both vagal cardiopulmonary baroreceptor activity and efferent renal sympathetic nerve activity (ERSNA) in the natriuretic response to saline volume expansion (SVE), three series of experiments were undertaken in anaesthetized rats.

2. In the first two series of experiments, the natriuretic (series A) and ERSNA (series B) responses to SVE were evaluated in both sham operated and cervical bilateral vagotomized rats. The acute experiment consisted of two baseline (BL) periods, treatment (sham control (CTR) or real cervical bilateral vagotomy), a volume expansion phase (Ringer’s solution, 10% bodyweight) and a postexpansion phase. The results of these two series indicate that vagotomy significantly enhances basal ERSNA (37±8%; P < 0.05 vs BL) and significantly attenuates the renal sympathoinhibitory response (by approximately 50%; P < 0.05 vs CTR) but not the natriuretic response to SVE, suggesting the potential expression of a vagotomy induced compensatory natriuretic mechanism.

3. To assess this, the natriuretic response to SVE was evaluated in chronic sham operated or renal denervated groups of rats in which vagotomy was or was not performed (series C). There were no differences among groups in either systemic haemodynamics or plasma protein concentration. Vagotomy plus chronic renal denervation induced a supranormal natriuretic and diuretic response (approximately 30%; P < 0.01) to SVE when compared with similar natriuretic and diuretic responses of the remaining groups.

4. These data support the idea that, in intact rats on a normal sodium diet, neither cardiopulmonary baroreceptors nor renal nerves are necessary for the elimination of an acute intravenous isotonic sodium load and indicate that during SVE the activation of vagal cardiopulmonary baroreceptors exerts an inhibitory effect on both ERSNA and the expression of a natriuretic mechanism. Such a natriuretic mechanism is expressed only when SVE is induced in vagotomized rats (compensating for the vagotomy mediated antinatriuretic effects of an enhanced ERSNA), but is unmasked only when, in addition, renal nerves are chronically transected. All of this offers an efficient element of safety in eliminating an acute isotonic sodium load when cardiopulmonary baroreceptors are severed.
Viral‐Mediated Gene Delivery Of Constitutively Activated GΑS Alters Vasoreactivity
Authors: Schutzer William E , Watts Val J , Chapman Justin , Cumbay Medhane G , Neve Kim A , Neve Rachael L , Mader Scott L
Published: March 2003

1. Decline in β‐adrenoceptor (β‐AR)‐mediated function occurs with increasing age, as well as in multiple disease conditions. The mechanisms responsible for this decline include alterations in β‐AR itself, β‐AR coupling proteins, such as G‐proteins, or other β‐AR‐linked proteins, such as G‐protein receptor kinases and/or phosphatases.

2. The present study examines the physiological effects of in vitro transfer of constitutively activated Gαs (Gαs‐Q227L) to both cultured vascular smooth muscle cells (VSMC) and whole aortic tissue of 6‐month‐old (adult) animals via a replication‐deficient Herpes simplex virus (HSV) vector. These studies were conducted to provide a model for future examination of the role of Gαs in the age‐related decline in β‐AR‐mediated vasorelaxation.

3. Gene transfer was confirmed by western blotting for specific proteins. Aortic tissue infected with HSV–Gαs‐Q227L had reduced phenylephrine‐induced contraction and enhanced isoproterenol‐stimulated vasorelaxation. Infection of cultured VSMC with HSV–Gαs‐Q227L increased both basal‐ and isoproterenol‐stimulated cAMP accumulation, whereas forskolin‐stimulated cAMP production was unchanged.

4. These results implicate Gαs as a target for further investigation in age‐related changes in vascular reactivity and support the use of viral‐mediated gene transfer as an effective tool to study adrenergic signal transduction and physiology in vascular tissue.