The 100 Most-Cited Articles Focused on Ultrasound Imaging: A Bibliometric Analysis

Purpose The number of citations that an article has received reflects its impact on a particular research area. The aim of this study was to identify the 100 most-cited articles focused on ultrasound (US) imaging and to analyze the characteristics of these articles. Methods We determined the 100 most-cited articles on US imaging via the Web of Science database, using the search term. The following parameters were used to analyze the characteristics of the 100 most-cited articles: publication year, journal, journal impact factor, number of citations and annual citations, authors, department, institution, country, type of article, and topic. Results The number of citations for the 100 most-cited articles ranged from 1849 to 341 (median: 442.0) and the number of annual citations ranged from 108.0 to 8.1 (median: 22.1). The majority of articles were published in 1990 - 1999 (39 %), published in radiology journals (20 %), originated in the United States (45 %), were clinical observation studies (67 %), and dealt with the vessels (35 %). The Department of Internal Medicine at the University of California and the Research Institute of Public Health at the University of Kuopio (n = 4 each) were the leading institutions and Salonen JT and Salonen R (n = 4 each) were the most prolific authors. Conclusion Our study presents a detailed list and analysis of the 100 most-cited US articles, which provides a unique insight into the historical development in this field.

Effectiveness of Osteoporosis Drug in Postmenopausal Women with Spinal Compression Fracture: Combined Consecutive Therapy of Teriparatide and Raloxifene versus Bisphosphonate Single

Objective

Bisphosphonate, a typical bone resorption inhibitor, is an important first-line drug for treating osteoporosis. Recent studies show a novel paradigm in stimulating bone formation. Teriparatide, which is composed of recombinant human parathyroid hormone, stimulates osteoblasts and induces bone regeneration. Bone mineral density (BMD) that was used before and after the treatment with anti-osteoporosis drug was compared for the effectiveness in therapy between a combination of teriparatide and selective estrogen receptor modulator (SERM), and bisphosphonate.

Methods

We retrospectively reviewed the outcomes of 85 postmenopausal women who were concurrently diagnosed with osteoporosis and spinal compression fracture between November 2008 and January 2015. The targeted group were treated with teriparatide and SERM (TS group, n=26) and bisphosphonate (B group, n=59).

Results

In both groups, BMD of femur neck was not improved after the medication. In the TS group, on the other hand the BMD and T-score of lumbar spine has significantly improved. BMD ratio of lumbar spine was prominently higher than those of TS group.

Conclusion

The combination therapy of teriparatide and SERM was very effective in treating the lumbar spine, compared to that of bisphosphonate. Although the period of teriparatide treatment has been relatively short, the preventive effects of compression fracture were considerable. Thus, combination therapy of teriparatide and SERM is highly recommended for patients who are concerned with spinal compression fracture from osteoporosis.

Multiple overlapping stent-assisted coiling of complex aneurysms: a single-center experience

OBJECTIVES

Coil embolization of wide-necked and fusiform aneurysms is challenging and is frequently associated with recanalization despite assistance of any additional device. The purpose of this study was to evaluate the feasibility and mid-term outcomes of complex aneurysms after multiple overlapping stent-assisted coiling (OSAC).

METHODS

We retrospectively evaluated 26 wide-necked and fusiform atherosclerotic or dissecting aneurysms that were treated with multiple OSAC. Eight aneurysms (30·8%) presented with subarachnoid hemorrhage and one (3·9%) with intracranial hemorrhage.

RESULTS

Complete embolization was achieved in 15 of the 26 aneurysms (57·7%), while remnant neck was identified in nine (34·6%) and remnant aneurysm was noted in two (7·7%). Immediate procedure-related complications were observed in five patients (19·2%) including two with asymptomatic in-stent thrombosis, one with transient right-sided weakness, one with decreased mentality, and one with aphasia and quadriplegia. A procedure-related permanent neurologic deficit (modified Rankin scale scores of 1 and 5) was noted in two patients (7·7%). Angiographic follow-up (mean duration 23·9 months) after OSAC was carried out in 18 patients (69·2%): 11 (61·1%) were stable, 3 (16·7%) improved, 3 (16·7%) had minor compaction, and 1 had major recanalization (5·5%). One recurred aneurysm after OSAC and two recanalized aneurysms after single stenting were re-treated using additional stent-assisted coiling, and there was no recanalization in these three aneurysms during the 25·7 months after re-treatment.

CONCLUSIONS

Multiple OSAC is feasible and effective for complex aneurysms and recurrent aneurysms after stent-assisted coiling.

Clinical Analysis of Risk Factors for Recurrence in Patients with Chronic Subdural Hematoma Undergoing Burr Hole Trephination

OBJECTIVE

Chronic subdural hematoma (CSDH) is one of the most common types of intra-cranial hemorrhages usually associated with trauma. Surgical treatment is the treatment of choice and burr hole trephination (BHT) is widely performed. The recurrence rate in the patients with CSDH is 3.7-30%. This study investigated the risk factors associated with the recurrence of patients with CSDH who underwent BHT.

METHODS

One hundred twenty-five patients with CSDH underwent BHT. Eight of 125 patients (6.4%) underwent reoperation for recurrent CSDH. We retrospectively analyzed demographic, clinical and radiological findings, catheter tip location and drainage duration as the risk factors for the recurrence of CSDH.

RESULTS

Recurrence of CSDH in the high- or mixed-density groups was significantly higher than those in the low- or iso-density groups (p<0.001). Placement of catheter tip at the temporoparietal area was associated with a significantly higher recurrence rate of CSDH than placement at the frontal area (p=0.006) and the brain re-expansion rate (BRR) was much lower than placement at the frontal area (p<0.001).

CONCLUSION

The operation may be delayed in high- and mixed-density groups, unless severe symptoms or signs are present. In addition, placing the catheter tip at the frontal area helps to reduce the incidence of postoperative recurrence of CSDH and to increase the BRR.

Perfusion defects detected after liver transplantation on multidetector computerized tomography: short- and long-term follow-up

BACKGROUND

Perfusion defects are sometimes found during the follow-up computerized tomography (CT) after liver transplantation (OLT). This study sought to determine the short- and long-term outcomes of perfusion defects observed after OLT with the use of multidetector CT.

METHODS

From February 4, 2004, to December 8, 2011, a total 46 LTs were performed in our hospital owing to end-stage liver cirrhosis (n = 43), liver cirrhosis with hepatocellular carcinoma (HCC; n = 1), combined HCC with cholangiocellular carcinoma (CCC; n = 1), or hepatic failure from acute hepatitis A (n = 1). The transplanted livers were procured from cadaveric (n = 24) or living related donors (n = 22). The average age of the recipient was 53.3 ± 10.4 years. The male-female ratio was 30:16. Postoperative multidetector CT was performed with a dynamic sequence in 203 examinations and with a portal phase in 46 examinations. The contrast media was Radisense. The rate of injection of 120 mL was 3 mL/s with a power injector; the iodine concentration was 300 or 370 mg/dL. Follow-up ranged from 3 months 3 days to 7 years 363 days. We classified perfusion defects as chronic segmental or subsegmental benign ischemia, transient focal perfusion defects, benign subcapsular ischemia, or fatal whole liver perfusion defects.

RESULTS

There were 3 cases of chronic segmental or subsegmental benign ischemia, 8 focal transient perfusion defects, 1 benign subcapsular ischemia, and 4 fatal whole liver perfusion defects. Except the fatal cases, all other perfusion defects occurred in the courses of benign conditions without resection or reoperation.

CONCLUSIONS

Most perfusion defects were benign and uneventful, requiring no treatment, with the exception of fatal whole liver perfusion defects, which resulted in death after detection.

Steroid-induced Spinal Epidural Lipomatosis after Suprasella Tumor Resection

Spinal epidural lipomatosis (SEL) is an abnormal localized accumulation of fat tissues in the epidural space. It is strongly related with steroid administration. The symptoms of SEL are various and range from back pain to paraplegia. In severe cases, decompressive laminectomy is the choice of treatment. A 32-year-old woman who had been under long-term steroid administration after suprasellar tumor resection was admitted for both leg radiating pain and weakness. She was diagnosed with SEL and had a decompressive laminectomy. During the operation, we found the nerve roots were compressed by epidural fat tissues and engorged vessels. After the operation, her radiating pain was relieved and motor weakness was improved.

Airway management using a supraglottic airway device without endotracheal intubation for positive ventilation of anaesthetized rats

Endotracheal intubation is often necessary for positive pressure ventilation of rats during open thoracic surgery. Since endotracheal intubation in rats is technically difficult and is associated with numerous complications, many techniques using various devices have been described in the scientific literature. In this study, we compared the effectiveness of airway management of a home-made supraglottic airway device (SAD), which is cheap to fabricate and easy to place with that of an endotracheal intubation tube in enflurane-anaesthetized rats. Twenty male Sprague-Dawley rats (200-300 g) were randomly assigned to two equal groups for positive pressure mechanical ventilation using either the SAD or an endotracheal intubation tube. The carotid artery of each rat was cannulated for continuous blood pressure measurements and obtaining blood samples for determination of oxygen tension, carbon dioxide tension, and blood acidity before, during and after SAD placement or endotracheal intubation. Proper placement of the SAD was confirmed by observing chest wall movements that coincided with the operation of the mechanical ventilator. No complications and adverse events were encountered in the rats in which the SAD was placed, during SAD placement and immediate removal, during their mechanical ventilation through the SAD, and one week after SAD removal. From the results of blood gas analyses, we conclude that anaesthetized rats can be successfully ventilated using an SAD for open thoracic surgery.

Evaluation of Chest Compression Depth during Nine Minutes of Hands-Only Cardiopulmonary Resuscitation Performed by a Lone Rescuer and its Effect by Age Group: A Pilot Simulation Study Using a Manikin

Objective

There have been few studies on the use of long-standing hands-only cardiopulmonary resuscitation (CPR) by a lone rescuer. This study aimed to evaluate the long-standing (nine minutes) hands-only CPR by a lone rescuer, and the change of chest compression depth over time. The effect of age of rescuer on chest compression depth was also studied.

Methods

From a total of 404 adult lay-persons who participated in CPR training, 91 subjects were enrolled in the simulation trial of nine minutes of hands-only CPR using a manikin with a Skill-Reporter™. The quality of the chest compression over time and the effects of rescuer age were analysed.

Results

Of the 91 participants, 74 (81%) fully completed the nine minutes of CPR. No significant differences of incomplete CPR rate between each age group were observed. No significant differences in the degree of reduction in effective chest compressions were observed based on the time course among the different age groups. The total number of compressions decreased abruptly from the six-minute time point onwards (five minutes vs. six minutes, p=0.038).

Conclusions

Most trained lay-persons could complete the 9 minutes of hands-only CPR. The rate of chest compression shows a significant decrease after 6 minute. We do not find a significant difference in the decrease of adequate chest compressions over time among various age groups in this pilot simulation study.

Effect of cisternal drainage on the shunt dependency following aneurysmal subarachnoid hemorrhage

Objective

Shunt-dependent chronic hydrocephalus (SDCH) is known to be a major complication associated with aneurysmal subarachnoid hemorrhage (aSAH). Old age is known to be one of numerous factors related to the development of SDCH. This study investigated whether postoperative cisternal drainage affects the incidence of SDCH and clinical outcome in elderly patients with aSAH.

Methods

Fifty-nine patients participated in this study. All patients underwent aneurysmal clipping with cisternal cerebrospinal fluid (CSF) drainage. Clinical variables relevant to the study included age, sex, location of ruptured aneurysm, CT finding and clinical state on admission, clinical outcome, and CSF drainage. We first divided patients into two groups according to age (<70 years of age and ≥70 years of age) and compared the two groups. Secondly, we analyzed variables to find factors associated with SDCH in both groups (<70 years of age and ≥70 years of age).

Results

Of 59 patients, SDCH was observed in 20 patients (33.9 %), who underwent shunt placement for treatment of hydrocephalus. Forty seven percent of cases of acute hydrocephalus developed SDCH. In the elderly group (≥70 years of age), the duration and amount of CSF drainage did not affect the development of chronic hydrocephalus.

Conclusion

In elderly patients, although the incidence of SDCH was significantly higher, clinical outcome was acceptable. The duration and the amount of cisternal drainage did not seem to be related to subsequent development of chronic hydrocephalus within elderly patients aged 70 or older.

Intravascular Papillary Endothelial Hyperplasia (Masson tumor) of the Skull : Case Report and Literature Review

A 10-year-old female patient presented with a rapidly growing nodular mass lesion on her right frontal area. On skull radiography and computed tomography (CT) imaging, this mass had a well-demarcated punch-out lesion with a transdiploic, exophytic soft tissue mass nodule on the frontal scalp. Magnetic resonance (MR) imaging revealed the presence of a 1.5×1.2×1 cm sized calvarial lesion. This lesion was hypointense on T1 and heterogenous hyperintense on T2 weighted MR images, and exhibited heterogeneous enhancement of the soft tissue filling the punch-out lesion after intravenous administration of gadolinium. En block removal of the tumor with resection of the rim of the normal bone was performed. The pathological diagnosis was intravascular papillary endothelial hyperplasia (IPEH). After surgery, no recurrence was found for 8 months. IPEH is a rare and benign reactive lesion usually found in thrombosed subcutaneous blood vessels. Involvement of skull bone is rare. In this article, we present a case of IPEH involving the calvarium, in a 10-year-old woman.

Comparison of Serum CRP and Procalcitonin in Patients after Spine Surgery

OBJECTIVE

Classical markers of infection cannot differentiate reliably between inflammation and infection after neurosurgery. This study investigated the dynamics of serum procalcitonin (PCT) in patients who had elective spine surgeries without complications.

METHODS

Participants were 103 patients (47 women, 56 men) who underwent elective spinal surgery. Clinical variables relevant to the study included age, sex, medical history, body mass index (BMI), site and type of surgery, and surgery duration. Clinical and laboratory data were body temperature, white blood cell count (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and PCT, all measured preoperatively and postoperatively on days 1, 3, and 5.

RESULTS

PCT concentrations remained at <0.25 ng/mL during the postoperative course except in 2 patients. PCT concentrations did not correlate with age, sex, DM, hypertension, BMI, operation time, operation site, or use of instrumentation. In contrast, CRP concentrations were significantly higher with older age, male, DM, hypertension, longer operation time, cervical operation, and use of instrumentation.

CONCLUSION

PCT may be useful in the diagnosing neurosurgical patients with postoperative fever of unknown origin.

CFD modelling of flow field and particle tracking in a hydrodynamic stormwater separator

The best management practices (BMPs) for control of urban stormwater pollution are evaluated to remove solid particles containing various pollutants. Currently, most storm runoff treatment devices using primary pollutant removal mechanism are applied to storm water since most pollutants in runoff are associated with the solid particulates. A hydrodynamic separator is a storm water treatment device using centrifugal motion which separates solids pollution from runoff. In this study, the velocity flow field and particle tracking of hydrodynamic separator were investigated using anthracite as a computational fluid dynamics (CFD) model particle. The Fluent 6.3.26 CFD program was used to predict the solid particles removal efficiency for various parameters such as particle size, surface loading rate, and the ratio of underflow to overflow. The velocity flow field in a hydrodynamic stormwater separator (HDS) has been simulated using CFD RNG κ-ε model. Modeling results for the removal efficiency of HDS were similar with the results obtained from experimental measurements of laboratory scale HDS. These results showed that the simulated velocity field was useful to interpret the behavior of flow in the hydrodynamic separator. The results obtained from particle tracking can be applied to predict the separation efficiency.

Stent-assisted coil embolization followed by a stent-within-a-stent technique for ruptured dissecting aneurysms of the intracranial vertebrobasilar artery

Object

A ruptured dissecting aneurysm of the vertebrobasilar artery (VBA-DA) is a well-known cause of acute subarachnoid hemorrhage (SAH) with a high rate of early rebleeding. Internal trapping of the parent artery, including the dissected segment, is one of the most reliable techniques to prevent rebleeding. However, for a ruptured VBA-DA not suitable for internal trapping, the optimal treatment method has not been well established. The authors describe their experience in treating ruptured VBA-DAs not amenable to internal trapping of the parent artery with stent-assisted coil embolization (SAC) followed by a stent-within-a-stent (SWS) technique.

Methods

Eleven patients—6 men and 5 women with a mean age of 48 years and each with a ruptured VBA-DA not amenable to internal trapping of the parent artery—underwent an SAC-SWS between November 2005 and October 2007. The feasibility and clinical and angiographic outcomes of this combined procedure were retrospectively evaluated.

Results

The SAC-SWS was successful without any treatment-related complications in all 11 patients. Immediate posttreatment angiograms revealed complete obliteration of the DA sac in 3 patients, near-complete obliteration in 7, and partial obliteration in 1. One patient died as a direct consequence of the initial SAH. All 10 surviving patients had excellent clinical outcomes (Glasgow Outcome Scale Score 5) without posttreatment rebleeding during a follow-up period of 8–24 months (mean follow-up 15 months). Angiographic follow-up at 6–12 months after treatment was possible at least once in all surviving patients. Nine VBA-DAs showed complete obliteration; the other aneurysm, which had appeared partially obliterated immediately after treatment, demonstrated progressive obliteration on 2 consecutive follow-up angiography studies. There was no in-stent stenosis or occlusion of the branch or perforating vessels.

Conclusions

The SAC-SWS technique seems to be a feasible and effective reconstructive treatment option for a ruptured VBA-DA. The technique may be considered as an alternative therapeutic option in selected patients with ruptured VBA-DAs unsuitable for internal trapping of the parent artery.

Initial troponin level as a predictor of prognosis in patients with intracerebral hemorrhage

OBJECTIVE

It has been suggested that elevated cardiac troponin T (cTnT) level is a marker of increased risk of mortality in acute ischemic stroke and subarachnoid hemorrhage (SAH). However, the association of serum cTnT level and prognosis of intracerebral hemorrhage (ICH) has been sparsely investigated. The aim of this study was to identify the relationship between cTnT level and the outcome in patients with spontaneous ICH.

METHODS

We retrospectively investigated 253 patients identified by a database search from records of patients admitted in our department for ICH between January 1, 2003 and December 31, 2007. The patients were divided into 2 groups; the patients in group 1 (n=225) with serum cTnT values of 0.01 ng/mL or less, and those in group 2 (n=28) with serum cTnT values greater than 0.01 ng/mL.

RESULTS

The serum cTnT level was elevated in 28 patients. There were significant differences in sex, hypertension, creatine kinase-myocardial band, midline shift, side of hematoma, and presence of intraventricular hemorrhage between the 2 groups. Logistic regression analysis identified the level of consciousness on admission, cTnT and midline shift as independent predictors of hospital mortality.

CONCLUSION

Theses results suggest that increased serum cTnT level at admission is associated with in-hospital mortality and the addition of a serum cTnT assay to routine admission testing should be considered in patients with ICH.

Severe Symptomatic Vasospasm following Intraventricular Hemorrhage from Arteriovenous Fistula

The authors present a rare case of severe vasospasm following the rupture of arteriovenous fistula. On initial CT scan, hematoma in the corpus callosum and left inferior frontal region with surrounding cerebromalacia and all ventricles without apparent subarachnoid hemorrhage were seen. Angiograms showed arterivenous fistula but did not show cerebral vasospasm. Thirteen days after admission the neurological state of patient suddenly deteriorated and bilateral motor weaknesses developed. Following angiograms revealed severe narrowing on the supraclinoid portion of bilateral internal carotid arteries, bilateral anterior cerebral arteries and bilateral middle cerebral arteries. Transluminal angioplasty and intra-arterial papaverine infusion were performed. The patient remained stable with moderate neurologic deficits.

Reconstructive endovascular treatment of ruptured blood blister-like aneurysms of the internal carotid artery

OBJECT

Ruptured blood blister-like aneurysms (BBAs) of the internal carotid artery (ICA) are rare but carry a high rate of morbidity and mortality. Furthermore, BBAs are very difficult to treat surgically as well as endovascularly. The authors present their experience in treating BBAs with reconstructive endovascular methods.

METHODS

Nine ruptured BBAs in 9 consecutive patients (2 men and 7 women; mean age 50 years, range 42-57 years) were treated using reconstructive endovascular methods between January 2006 and November 2007. Treatment methods and angiographic and clinical outcomes were retrospectively evaluated.

RESULTS

All 9 BBAs were initially treated with stent-assisted coil (SAC) embolization. This was followed by a second stent insertion using the stent-within-a-stent (SWS) technique in 3, covered stent placement in 3, and SAC embolization alone in 3. All 3 patients who underwent SWS placement had excellent outcomes (Glasgow Outcome Scale Score 5) with complete angiographic resolution of the BBAs. There were no treatment-related complications in the SWS group. Two of the 3 patients who received covered stents had excellent outcomes (Glasgow Outcome Scale Score 5) and complete occlusion of the BBA was achieved. The remaining patient who received a covered stent died of ICA rupture during the procedure. Aneurysm regrowth without rebleeding occurred in the 3 patients who underwent SAC embolization. Two of the 3 recurrent BBAs were treated with coil embolization with a second stent insertion, and as a result these belonged to the SWS group. The other recurrent BBA was treated with a covered stent. Of the 8 surviving patients, 5 underwent SWS, and 3 underwent covered stent placement. All surviving patients had excellent outcomes during the clinical follow-up period (mean 11 months, range 4-26 months); complete BBA resolution and smooth reconstruction of the affected ICA segment was shown on follow-up angiography.

CONCLUSIONS

In the present study, the SWS and covered-stent techniques effectively prevented rebleeding and regrowth of the BBA without sacrifice of the ICA. The SWS and covered-stent techniques can be considered an alternative treatment option for BBAs in selected patients in whom ICA sacrifice is not feasible. Stent-assisted coiling alone seems insufficient to prevent BBA regrowth.

Multidetector row CT angiography in spontaneous lobar intracerebral hemorrhage: a prospective comparison with conventional angiography

BACKGROUND AND PURPOSE

The aim of our study was to assess the accuracy of multidetector row CT angiography (MDCTA) in the detection of the underlying vascular abnormalities causing spontaneous lobar intracerebral hemorrhage (ICH) compared with conventional digital subtraction angiography (DSA).

MATERIALS AND METHODS

Seventy-eight patients who underwent MDCTA with use of a 16-detector row scanner and DSA were prospectively included in this study. Each study was assessed by 2 independent blinded neuroradiologists; decisions were made in consensus. Findings on CT angiograms, including the original axial data, multiplanar reformations, and volume-rendered images with and without automated bone segmentation, were used to identify the underlying causes of ICH.

RESULTS

Twenty-two of the 78 patients (28.2%) exhibited angiographic abnormalities, including aneurysms of the proximal arteries (n = 9), arteriovenous malformations (n = 7), Moyamoya disease (n = 4), and aneurysms of the distal arteries (n = 2). MDCTA detected the underlying vascular abnormalities in 21 patients except 1 case of small arteriovenous malformation. Overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCTA for detection of underlying vascular abnormalities were 95.5%, 100%, 100%, 98.2%, and 98.7%, respectively.

CONCLUSIONS

MDCTA is a highly accurate imaging technique in the diagnosis of underlying vascular abnormalities in patients with spontaneous lobar ICH.

Real-time atomic force microscopy using mechanical resonator type scanner

The real-time atomic force microscope for biological sample is a challenging research field. We have demonstrated a real-time atomic force microscope by implementing a mechanical resonator type scanner called by "microscanner" The microscanner was designed to have a resonance frequency in the range of 5-10 kHz and an amplitude of 1-3 microm. The resonant vibration of the microscanner was served as a fast-scan directional motion, and an image acquisition rate of 30 frames/s with 256x256 pixels per frame was achieved. Time-varying sequential images of a poly(ethylene-oxide) sample were taken as a demonstration of potential for excellence in real-time imaging a moving nano-object.

Spontaneous pancreatic pseudocyst-portal vein fistula presenting with pancreatic ascites: strength of MR cholangiopancreatography

Pancreatic pseudocyst-portal vein fistulae are a very rare complication of acute or chronic pancreatitis. Another late complication of chronic pancreatitis is pancreatic ascites. We report the case of a 43-year-old man with a spontaneous pseudocyst-portal vein fistula presenting with pancreatic ascites diagnosed by various imaging modalities, in order to emphasize the strength and efficacy of magnetic resonance cholangiopancreatography.

Treatment of blood blister–like aneurysm of the internal carotid artery with stent-assisted coil embolization followed by stent-within-a-stent technique

✓Ruptured blood blister–like aneurysms (BBAs) of the internal carotid artery (ICA) are potentially dangerous lesions because of the high risk of intraoperative bleeding associated with their wide fragile neck. The authors discuss cases in which BBAs were treated endovascularly during the chronic stage and report a case in which a ruptured BBA of the ICA was successfully treated in the acute phase with stent-assisted coil embolization and a subsequent stent-within-a-stent procedure.

Clinical outcome and ischemic complication after treatment of anterior choroidal artery aneurysm: comparison between surgical clipping and endovascular coiling

BACKGROUND AND PURPOSE

Although coiling has been favorably comparable with clipping for treatment of most intracranial aneurysms, there is a controversy on which modality is safer for anterior choroidal artery (AchoA) aneurysm. We retrospectively evaluated the clinical outcomes and treatment-related complications after surgical clipping and endovascular coiling of AchoA aneurysms.

MATERIALS AND METHODS

Seventy-three AchoA aneurysms were recruited from 1895 intracranial aneurysms, which were treated either by surgical clipping or by endovascular coiling in 4 institutions between May 1999 and December 2006. The AchoA aneurysms were dichotomized according to the modality of treatment, the coil group (37 patients; 38 aneurysms) and the clip group (35 patients; 35 aneurysms). Clinical outcomes and incidence of treatment-related complications between 2 groups and the factors influencing the clinical outcomes were evaluated.

RESULTS

There was no rebleeding in both groups during follow-up, for 4-72 months (mean, 27 months) in the coil group and for 3-84 months (mean, 34 months) in the clip group. In the coil group, 31 patients (83.8%) had favorable outcome (modified Rankin Scale score [mRS], 0-3). In the clip group, 31 patients (88.6%) had favorable outcome. The complication of coiling was transient contralateral hemiparesis in 2 patients, who recovered completely. The complications of clipping were permanent contralateral hemiparesis due to AchoA infarction in 4 patients and third-nerve palsy in 1 patient. Hunt and Hess grade 4 or 5 and AchoA infarction were significantly correlated with poor outcome (mRS, < or =4). Clipping had significantly higher incidence of AchoA infarction than coiling (P < .05).

CONCLUSION

Coiling of AchoA aneurysms appears comparable with clipping in clinical outcome and prevention of rebleeding, with significantly lower incidence of AchoA infarction than clipping.

A Comparative Coagulopathic Study for Treatment of Vasospasm by Using Low- and High-molecular Weight Hydroxyethyl Starches

OBJECTIVE

High-molecular-weight hydroxyethyl starch (HES) compromises blood coagulation more than does low-molecular-weight HES. We compared the effects of low- and high-molecular-weight HES for the treatment of vasospasm and investigated the dose relationship with each other.

METHODS

Retrospectively, in a series of consecutive 102 patients with subarachnoid hemorrhage (SAH), 35 patients developed clinical symptoms of vasospasm of these fourteen patients were treated with low-molecular-weight HES for volume expansion while the other 21 received high-molecular-weight HES as continuous intravenous infusion. Prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen level, and platelet count were all measured prior to initiation, during treatment and after termination of therapy for symptomatic vasospasm. The total dose of HES ranged from 5 L to 14 L and median infusion duration was 10 days.

RESULTS

A more pronounced PTT prolongation was observed in high-molecular-weight HES group compared with low-molecular-weight HES group. No other coagulation parameters were altered. Dosage (=duration) shows a positive correlation with PTT. Clinically, significant bleeding episodes were noted in four patients who received high-molecular-weight HES.

CONCLUSION

Coagulopathy was developed in direct proportion to molecular weight of starch and dosages. We propose the extreme caution in the administration of HES solution for the vasospasm treatment.

Detection and characterization of intracranial aneurysms with 16-channel multidetector row CT angiography: a prospective comparison of volume-rendered images and digital subtraction angiography

BACKGROUND AND PURPOSE

The aim of our study was to compare multidetector row CT angiography (MDCTA) with digital subtraction angiography (DSA) in the detection and characterization of intracranial aneurysms.

MATERIALS AND METHODS

In our blinded prospective study, 85 patients with suspected intracranial aneurysm (47 women, 38 men; age range, 19-83 years) underwent both 16-channel MDCTA and DSA. The MDCT angiograms were interpreted for the presence, location, size, ratio of the neck to the dome (N/D ratio), and lobularity of the aneurysms and relationship of the aneurysm with the adjacent arterial branches, by using volume-rendering techniques. MDCTA and DSA images (reference standard) were interpreted by 2 independent readers, and the results were compared.

RESULTS

A total of 93 aneurysms were detected at DSA in 71 patients, whereas no aneurysms were detected in 14 patients. Compared with DSA, the overall sensitivity, specificity, and accuracy of MDCTA on a per-aneurysm basis were 92.5%, 93.3%, and 92.6%, respectively, for both independent readers. For aneurysms of <3 mm, however, MDCTA had a sensitivity of 74.1% for reader 1 and 77.8% for reader 2. There was excellent agreement between readers in the detection of aneurysms (kappa = 0.822). In addition, MDCTA was also accurate in determining N/D ratio of aneurysms, aneurysm lobularity, and adjacent arterial branches.

CONCLUSION

MDCTA is accurate in the detection and characterization of intracranial aneurysms and can be used as a reliable alternative imaging technique to DSA in selected cases.

Multidetector-row CT angiography of cerebral vasospasm after aneurysmal subarachnoid hemorrhage: comparison of volume-rendered images and digital subtraction angiography

BACKGROUND AND PURPOSE

Cerebral vasospasm remains a major problem in patients recovering after surgical treatment of cerebral aneurysms. The purpose of this study was to evaluate cerebral vasospasm at multidetector-row spiral CT angiography (MDCTA) compared with digital subtraction angiography (DSA) in patients with aneurysmal subarachnoid hemorrhages (SAHs).

METHODS

Seventeen patients suspected of having vasospasm on clinical findings underwent both postoperative MDCTA and DSA. MDCTA was analyzed by using volume-rendered images as well as axial images. A total of 251 arterial segments were analyzed for vasospasm by using a 5-point grading system. The MDCTA results were then compared with findings on the corresponding DSA images. Sensitivity, specificity, and accuracy of MDCTA for detection of hemodynamically significant spasms were also calculated, with findings at DSA used as the reference standard.

RESULTS

On DSA, 74 spasmatic segments were found among the 251 segments evaluated, and 40 segments with hemodynamically significant vasospasms were present. The overall agreement between MDCTA and DSA was 95.2%. We had 12 (4.8%) cases of disagreement between MDCTA and DSA. In 11 segments, the degree of stenosis was overestimated at MDCTA. Overall accuracy, sensitivity and specificity of MDCTA in the detection of hemodynamically significant vasospasm were 97.5%, 98.1%, and 98.0%, respectively, with positive and negative predictive values of 90.7% and 99.5%.

CONCLUSION

MDCTA appears to be a reliable alternative imaging technique to DSA in the assessment of patients with cerebral vasospasm after aneurysmal SAH.

Intussusception after gastric surgery

Intussusception following gastric surgery is a rare postoperative complication. It may develop in clinical situations following gastroenterostomy, Billroth II gastric surgery with or without Braun anastomosis, or Roux-en-Y gastrojejunostomy. The patients may present with either an acute surgical emergency or with a chronic, relapsing form. The mortality may be up to 50 % in these cases if not treated appropriately, but little is known about the mechanism underlying the condition. Early diagnosis with a high index of suspicion and prompt treatment of the acute form are therefore important. Surgical reduction with laparotomy is mandatory, although definitive corrective and preventative measures have not yet been established.

Benign Breast Diseases Associated With Cyclosporine Therapy in Renal Transplant Recipients

PURPOSE

Our aim was to correlate the radiologic characteristics of cyclosporine-induced benign breast diseases with clinical and pathologic findings.

MATERIALS AND METHODS

The clinical, mammographic, and ultrasonographic records of 33 female renal transplant recipients who received cyclosporine were retrospectively reviewed. Eleven patients had 46 breast masses on ultrasonography. We performed core needle biopsies on 20 masses and reviewed the pathologic findings.

RESULTS

Among 33 female renal transplant recipients, 11 (33%) had 46 benign breast lesions detected on ultrasonography. We performed core needle biopsies on 20 of the 46 masses. On pathologic examination, 12 were fibroadenomas, 6 showed fibrocystic changes, and 2 revealed dense fibrosis. Regardless of the final pathologic diagnosis, more than half of the lesions revealed severe lymphatic and venular swellings. Among 11 patients with breast lesions on ultrasonography, 10/11 (91%) showed multiplicity, and 7/11 (64%) bilaterality. Mammographically, patients with breast lesions revealed heterogeneous or extremely dense breast patterns, and 8 of 11 patients, circumscribed masses. Twenty-two patients without breast lesions showed scattered fibroglandular densities (n = 7), or heterogeneously dense (n = 11) or extremely dense (n = 4) breast patterns, and 3 of 22 patients showed vague or asymmetric densities that needed further evaluation.

CONCLUSION

The development of new breast lesions in patients after renal transplantation should suggest a diagnosis of cyclosporine-induced benign breast disease including fibroadenoma, fibrocystic changes, and dense fibrosis.

Oviductural carcinoma in B6C3F1 female mice exosed to 0.5 ppm ozone

The toxicity and carcinogenecity of ozone was evaluated in B6C3F1 mice exposed to 0.5 ppm ozone via inhalation for 12 w, during which no ozone-related deaths occurred. Decreases in mean body weights of both genders exposed to ozone were sporadically seen, and mean absolute and relative weights of several organs from male and female groups receiving ozone were lower than those of respective air-control groups. No ozone-related increased neoplasm incidences were observed in most organs, including the lung; however, oviductural carcinomas were seen in the ozone-exposed females. Although ozone does not induce lung cancer under our experimental condition, it induces oviductural carcinomas in B6C3F1 mice.

Peripheral blood mitochondrial DNA content is inversely correlated with insulin secretion during hyperglycemic clamp studies in healthy young men

Abnormalities in mitochondrial DNA(mtDNA) have been implicated in the pathogenesis of diabetes mellitus. We recently reported that decreased mtDNA content precedes the development of diabetes mellitus and is associated with parameters of insulin resistance. In this study, we examined whether there is any relation between mtDNA content and insulin secretion. We compared the mtDNA content of peripheral blood leukocytes with the parameters of insulin secretion measured by hyperglycemic clamp in a group of healthy young men. There were statistically significant correlations between mtDNA content in peripheral blood and fasting plasma insulin (r=-0.43, P<0.05) and C-peptide levels (r=-0.44, P<0.05). MtDNA content also correlated negatively with acute insulin response(r=-0.48, P<0.05), late insulin response (r=-0.50, P<0.05) during hyperglycemic clamp and insulin secretion after glucagon stimulation (r=-0.60, P<0.01). mtDNA content in peripheral blood correlated negatively with homeostasis model (HOMA) insulin resistance (r=-0.45, P<0.05) although it did not correlate with the insulin insensitivity index (M/I) during hyperglycemic clamp. In summary, the mtDNA content of peripheral blood correlated negatively with indices of insulin resistance and insulin secretion in healthy young men. The compensatory response of pancreas beta cells to insulin resistance might contribute in part to increased insulin secretion in these subjects.

Microalbuminuria is associated with the insulin resistance syndrome independent of hypertension and type 2 diabetes in the Korean population

To investigate whether microalbuminuria is associated with the insulin resistance syndrome independent of hypertension and type 2 diabetes, we studied the association between microalbuminuria and features of insulin resistance syndrome in Korean general population. We selected 1006 subjects by a random cluster sampling among residents aged >40 years living in the Chung-Up district, a rural area of South Korea. Subjects were stratified by oral glucose tolerance status [normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and diabetes mellitus], and by the presence or absence of hypertension. Urinary albumin excretion rate (UAER) was determined using timed overnight urine collection. Various cardiovascular risk factors including anthropometric indices, serum lipid, true insulin and proinsulin concentrations were also measured. The prevalence of microalbuminuria (UAER between 20 and 200 microg/min) increased as the glucose tolerance worsened (6.0% in NGT, 11.8% in IGT, and 21.8% in diabetes; chi(2) trend=25.9, P<0.001). Subjects with microalbuminuria had a higher body mass index (BMI), waist-to-hip circumference ratio (WHR), systolic and diastolic blood pressure (BP), fasting and 2 h plasma glucose, fasting plasma insulin and proinsulin levels, and lower HDL-cholesterol level than subjects without microalbuminuria. In multiple regression analysis, BMI, diastolic BP, 2 h plasma glucose, and fasting plasma insulin levels were found to be independent factors associated with UAER. Multiple logistic regression analysis showed that not only diabetes mellitus and hypertension, but also fasting hyperinsulinemia and waist-to-hip ratio were independent factors associated with the presence of microalbuminuria. When the normotensive, non-diabetic subjects were analyzed separately, fasting hyperinsulinemia and impaired glucose tolerance remained independent variables associated with the presence of microalbuminuria. These results show that microalbuminuria in the Korean general population is associated with hyperinsulinemia and central obesity, and suggest that microalbuminuria is a feature of the insulin resistance syndrome independent of hypertension or type 2 diabetes.

Low expression of p27(Kip1) in advanced mucoepidermoid carcinomas of head and neck

BACKGROUND

p27(Kip1), a cyclin-dependent kinase inhibitor, negatively regulates the G1 phase progression of the cell cycle by binding to the cyclin E/cyclin-dependent kinase 2 complex. This study was done to investigate the expression of p27(Kip1) in mucoepidermoid carcinomas and its usefulness as an indicator in tumor progression, aggressiveness, and prognosis.

METHODS

Thirty-one patients with mucoepidermoid carcinomas who had surgical resection were studied retrospectively. Clinicopathologic features, including histologic types, T stage, nodal status, perineural invasion, overall AJCC stage, and survival data, were obtained from medical records. Immunohistochemical staining with monoclonal antibodies against p27(Kip1) was performed on the formalin-fixed, paraffin-embedded specimens from each patient. The percentage of tumor cells expressing p27(Kip1) (labeling index) was evaluated by counting 1000 cells per slide in at least four different areas and comparing with the patients' clinicopathologic features and survival rates.

RESULTS

Significant correlation was found between low p27(Kip1) expression and tumors with high-grade, advanced T stages, positive nodal status, and advanced clinical stages (p =.001 for all) except perineural invasion. Multivariate analysis indicated that p27(Kip1) expression (p =.030) was the most significant, and gender (p =.048) was the next significant predictor of overall survival among the variables. Also patients with low p27(Kip1) expression showed poor prognosis (p =.002).

CONCLUSIONS

We suggest that p27(Kip1) is a reliable independent marker of tumor progression, invasiveness, and prognosis in the mucoepidermoid carcinomas.

Free fatty acids induce peripheral insulin resistance without increasing muscle hexosamine pathway product levels in rats

To evaluate the role of the hexosamine biosynthesis pathway (HBP) in fat-induced insulin resistance, we examined whether fat-induced insulin resistance is additive to that induced by increased HBP flux via glucosamine infusion and, if so, whether such additive effects correlate with muscle HBP product levels. Prolonged hyperinsulinemic (approximately 550 pmol/l) euglycemic clamps were conducted in conscious overnight-fasted rats. After the initial 150 min to attain steady-state insulin action, rats received an additional infusion of saline, Intralipid, glucosamine, or Intralipid and glucosamine (n = 8 or 9 for each) for 330 min. At the conclusion of clamps, skeletal muscles (soleus, extensor digitorum longus, and tibialis anterior) were taken for the measurement of HBP product levels. Intralipid and glucosamine infusions decreased insulin-stimulated glucose uptake (Rd) by 38 and 28%, respectively. When the infusions were combined, insulin-stimulated Rd decreased 47%, significantly more than with Intralipid or glucosamine alone (P < 0.05). The glucosamine-induced insulin resistance was associated with four- to fivefold increases in muscle HBP product levels. In contrast, the Intralipid-induced insulin resistance was accompanied by absolutely no increase in HBP product levels in all of the muscles examined. Also, when infused with glucosamine, Intralipid decreased insulin action below that with glucosamine alone without changing HBP product levels. In a separate study, short-term (50 and 180 min) Intralipid infusion also failed to increase muscle HBP product levels. In conclusion, increased availability of plasma free fatty acids induces peripheral insulin resistance without increasing HBP product levels in skeletal muscle.

Short-term K(+) deprivation provokes insulin resistance of cellular K(+) uptake revealed with the K(+) clamp

We aimed to test the feasibility of quantifying insulin action on cellular K(+) uptake in vivo in the conscious rat by measuring the exogenous K(+) infusion rate needed to maintain constant plasma K(+) concentration ([K(+)]) during insulin infusion. In this "K(+) clamp" the K(+) infusion rate required to clamp plasma [K(+)] is a measure of insulin action to increase net plasma K(+) disappearance. K(+) infusion rate required to clamp plasma [K(+)] was insulin dose dependent. Renal K(+) excretion was not significantly affected by insulin at a physiological concentration ( approximately 90 microU/ml, P > 0.05), indicating that most of insulin-mediated plasma K(+) disappearance was due to K(+) uptake by extrarenal tissues. In rats deprived of K(+) for 2 days, plasma [K(+)] fell from 4.2 to 3.8 mM, insulin-mediated plasma glucose clearance was normal, but insulin-mediated plasma K(+) disappearance decreased to 20% of control, even though there was no change in muscle Na-K-ATPase activity or expression, which is believed to be the main K(+) uptake route. After 10 days K(+) deprivation, plasma [K(+)] fell to 2.9 mM, insulin-mediated K(+) disappearance decreased to 6% of control (glucose clearance normal), and there were 50% decreases in Na-K-ATPase activity and alpha2-subunit levels. In conclusion, the present study proves the feasibility of the K(+) clamp technique and demonstrates that short-term K(+) deprivation leads to a near complete insulin resistance of cellular K(+) uptake that precedes changes in muscle sodium pump expression.

Comparison of two immunization schedules for a Pseudomonas aeruginosa outer membrane proteins vaccine in burn patients

The aim of the present study was to compare two immunization schedules for a Pseudomonas aeruginosa outer membrane proteins (OMPs) vaccine in burn patients. In a double-blind, randomized and placebo-controlled clinical trial, 95 adult patients with burn injuries in 10% or greater of total body surface area were randomly allocated to either placebo or immunization groups. Three doses of the vaccine (0.5 or 1.0 mg) were administered intramuscularly at either 3- or 7-day intervals. The vaccine was well tolerated, and no severe adverse reactions were observed in any of the vaccinees. After three immunizations, 88 patients were available for evaluation of serum antibody titers. Elevation of OMPs-specific antibody titers in the immunization groups was significantly higher as compared with the placebo group, and the highest antibody response was obtained by immunization with 1.0-mg doses at 3-day intervals. Conventional blood culture, tissue culture of wound biopsy specimens and a nested polymerase chain reaction (PCR) assay of blood specimens were performed to determine the protective efficacy. The results of the nested PCR indicated that the overall detection rate of P. aeruginosa in blood was significantly lower among immunized patients than placebo patients (6.1 vs. 40.0%, P<0.001). Based on these results, we concluded that the P. aeruginosa OMPs vaccine is safe and highly immunogenic in burn patients, especially with 1.0-mg doses at 3-day intervals, and may be effective in conferring protection against P. aeruginosa bacteremia in burn patients.

Association between birth weight and insulin sensitivity in healthy young men in Korea: role of visceral adiposity

Recent studies have demonstrated decreased insulin sensitivity in individuals with low birth weight. This study was performed to examine whether abdominal obesity is a link between insulin resistance and low birth weight. We studied the relationships between birth weight and insulin secretion, insulin sensitivity, and various anthropometric indices including visceral fat area in 22 healthy young Korean adults. Birth weight correlated significantly with diastolic blood pressure (r=-0.47, P<0.05) and insulin sensitivity index (S(I)) measured by a frequently sampled intravenous glucose tolerance test (FSIGT) (r=0.54, P<0.05), but not with insulin secretory indices such as acute insulin responses during FSIGT (r=-0.35, NS) or hyperglycemic clamp (r=0.17, NS) and submaximum insulin response during hyperglycemic clamp (r=0.10, NS). S(I) correlated significantly with abdominal obesity measurements such as waist circumference (r=-0.48, P<0.05), waist-to-hip ratio (r=-0.53, P<0.05) and visceral fat area (r=-0.58, P<0.01). However, we could not find significant correlation between birth weight and any of the abdominal obesity measurements (r=-0.35 for waist-to-hip ratio, r=-0.22 for visceral fat area, and r=-0.24 for visceral-to-subcutaneous fat ratio; NS for all). The present data confirm that low birth weight is associated with insulin resistance in adult life. However, our data suggest that the association between low birth weight and insulin resistance is not mediated by abdominal obesity.

Radiologic findings of abdominal polyarteritis nodosa

OBJECTIVE

The purpose of this study was to evaluate the radiographic and imaging findings of seven patients with polyarteritis nodosa involving the abdomen.

CONCLUSION

Vasculitis should be considered when multiple abdominal organs have abnormal radiologic findings; however, angiography is necessary to specifically diagnose polyarteritis nodosa.

Ciliated foregut cyst of the gallbladder: a case report and review of the literature

A case is presented of a ciliated cyst of the gallbladder in a 36-year-old Korean woman which was incidentally found on ultrasonographic study. A cystic mass measuring 1.5 x 1 x 1 cm was found in the fundus of the gallbladder. The cyst was unilocular and intramural without communication to the lumen. Microscopically, the cyst wall was lined by a single layer of pseudostratified, ciliated, columnar epithelium and goblet cells with underlying smooth muscle layers. This was considered to be the cyst arising from the embryonic foregut and showing differentiation toward respiratory structures. The term 'ciliated foregut cyst of the gallbladder' is suggested here.

Transrectal ultrasonography of distal ureteral calculi: comparison with intravenous urography

In a prospective fashion, transrectal ultrasonography and intravenous urography were performed in 48 patients with distal ureteral calculi. We compared the ability of the two modalities to detect calculus and to determine the size of the calculus, the degree of obstruction, and the degree of hydroureter. In 11 cases (23%), the calculus was not seen at intravenous urography, while transrectal ultrasonography detected calculus in each patient. In 37 cases in which calculi were detected by both modalities, the average diameter of the calculus determined by ultrasonography was significantly larger (P < 0.05) than that obtained by plain radiography. Positive correlations were obtained in the assessment of degree of obstruction (correlation coefficient = 0.587, P < 0.05) and hydroureter (correlation coefficient = 0.794, P < 0.05) between the two techniques. Transrectal ultrasonography appears to be a useful adjunctive method to evaluate distal ureteral calculus, particularly if the results of intravenous urography are inconclusive.

Antibacterial properties and partial cDNA sequences of cecropin-like antibacterial peptides from the common cutworm, Spodoptera litura

The antibacterial properties and cDNA sequences of two types of antibacterial peptides from the haemolymph of immunized common cutworm, Spodoptera litura larvae, were determined. Since the primary structures of peptides deduced from cDNA sequences showed significant homologies to cecropins A and B, they were named as Spodoptera cecropins A and B. Spodoptera cecropins were broadly effective against Gram-positive and negative bacteria. They also retained antibacterial activities in all conditions tested (at pH 5.6-8.0 and in the presence of 50-150 mM NaCl) that was adapted to confirm the antibacterial properties of Spodoptera cecropins. These results indicate that the change of pH and the increase of salt concentration in the media do not influence the activities of Spodoptera cecropins. For the reverse transcription (RT)-polymerase chain reaction (PCR) to obtain the complete primary sequence, the primer designed according to the conserved region of the cecropin leader sequences was used, which was determined by the comparison of the cDNA sequences of known cecropins. The results from RT-PCR presented that the partial cDNAs of Spodoptera cecropins A and B encode 57 and 58 amino acids, including the sequences of mature peptides, respectively. In addition, Northern blot analysis with (32)P-labeled PCR product coding for Spodoptera cecropin A revealed that Spodoptera cecropin genes are expressed in immunized fat body, but not in normal fat body.

A study of the correlation between organic matrices and nanocomposite materials in oyster shell formation

Calcium carbonate minerals are an integral part of many organisms. These biogenic minerals are all of original size, shape and high strength, and they are quite different from those found in their abiotic precipitates. It has been accepted that the formation, morphological development and crystallography of the biocomposites are controlled by the intrinsic molecular recognition of macromolecules. In this study, with the analyses of X-ray diffraction and scanning electron microscopy of the texture of biogenic minerals in oyster shells, we noted that the intracrystalline proteins deliberately reduce the coherence lengths of biogenic crystals compared to synthetic ones, leading to more isotropy. In order to understand the exact nature of the controlled nucleation and growth, we investigated the changes in protein conformation in vivo from the mineral-specific layers using Fourier self-deconvolution and Gaussian curve-fitting techniques. And via in vitro assays, we studied the relation of such changes to biomineral phase and morphology. We showed that the shell proteins in vivo are in the higher structural ordered state, and beta-antiparallel structure was predominant in each shell layer. Also, as the shell undergoes a change of calcium carbonate polymorphs from aragonite to calcite, significant alterations of the protein conformation with the denaturing of alpha-helix and beta-structure in the aragonitic layer is induced. These results provide a relationship between the effects of conformational changes on the nanostructure of biocomposites and the necessity of new synthetic strategies.

Prevalence and risk factors of low quantitative ultrasound values of calcaneus in Korean elderly women

Quantitative ultrasound (QUS) of bone is a new radiation-free, low-cost method that measures both bone mass and bone quality. This study was performed to establish the normative data of QUS for Korean women and to determine the prevalence and risk factors of low quantitative ultrasound values in a Korean elderly population. We studied 238 healthy women aged 20-29 years working at a hospital, and 552 women over 50 years of age living in six villages of Chung-Up district, a rural area of South Korea, using QUS measurement of bone. Broadband ultrasound attenuation and speed of sound were measured at the calcaneus, and an index combining these factors (stiffness index) was calculated. T-score was calculated from the data of young normal subjects. Of the 552 elderly women, 34.2% had T-scores between -1.0 and -2.5, and 11.8% had T-scores below -2.5. The prevalence of low quantitative ultrasound values increased with older age, longer duration following menopause, lower body mass index, younger age at menopause and smoking. In multiple logistic regression analysis, age (odds ratio = 1.40 per 5 years, P < 0.05), duration following menopause (odds ratio = 1.35 per 5 years, P < 0.05) and body mass index (odds ratio = 0.78 per quartile, P < 0.05) were independently associated with low quantitative ultrasound values. These results suggested that quantitative ultrasound measurement of the calcaneus could be a useful tool for epidemiological surveys of bone mass.

Purification and characterization of chitin-binding proteins from the hemolymph of sweet potato hornworm, Agrius convolvuli

Three chitin-binding proteins (CBPs: CBP9, CBP15, CBP66) were identified from the larval hemolymph of sweet potato hornworm, Agrius convolvuli. Two (CBP9 and CBP15) of them have been isolated and purified by gel filtration (Superdex HR 75), cation-exchange chromatography (Mono S), and reverse-phase chromatography (muRPC PC 2.1/3). In experiments to detect CBPs in hemolymph, we examined whether ionic strength and existence of bovine serum albumin in the incubation solution influenced binding affinity of CBPs to chitin. The N-terminal sequences of three CBPs were determined by the automated Edman degradation and showed the sequence homology in basic local alignment search tool search CBP15 and CBP66 were quite similar to lysozymes and bovine serum albumins, respectively. In contrast, CBP9 is not similar to any other known protein, as judged from databank comparisons. Therefore, we concluded that CBP9 is a novel protein with binding capacity to chitin that is a component of the fungal cell wall. CBP9 has no antibacterial activity against Escherichia coli and Micrococcus luteus, and also showed negative response in hemagglutination assay. CBP9 is confirmed as a monomer with a molecular mass of 9.14 kDa by electron spray ionization and matrix-assisted laser desorption ionization mass spectrometry.

Peripheral blood mitochondrial DNA content correlates with lipid oxidation rate during euglycemic clamps in healthy young men

Both qualitative and quantitative changes in mitochondrial DNA (mtDNA) have been implicated in the pathogenesis of diabetes mellitus. It was previously found that decreased mtDNA content preceded the development of diabetes and mtDNA content correlated with the clinical parameters of insulin resistance syndrome, including diastolic blood pressure and waist-hip ratio. These results prompted one to look whether there are correlations between mtDNA content and the biochemical parameters of insulin resistance in non-diabetic subjects. MtDNA content of peripheral blood leukocytes was measured in Korean healthy young men, and this was correlated with various parameters of fuel metabolism at baseline and during euglycemic hyperinsulinemic clamps with indirect calorimetry. MtDNA content in peripheral blood leukocytes did not correlate with insulin sensitivity index or other metabolic variables such as body mass index (BMI), waist-to-hip ratio (WHR) and blood pressure. However, mtDNA content showed a positive significant correlation with fat oxidation rate during euglycemic clamps (r = 0.61, P < 0.05). Changes in fat oxidation rate and carbohydrate oxidation rate during the clamps were significantly correlated with mtDNA content (r = 0.65, P < 0.05, r = -0.65, P < 0.05, respectively). These results suggest that mtDNA content in peripheral blood may not correlate with insulin resistance per se but with some aspect of insulin resistance in healthy young men.

Acute effect of growth hormone to induce peripheral insulin resistance is independent of FFA and insulin levels in rats

To examine whether growth hormone (GH) induces peripheral insulin resistance by altering plasma free fatty acid (FFA) or insulin levels, the effects of GH infusion on insulin-stimulated glucose fluxes were studied in conscious rats under two protocols. In study 1, either saline (n = 7) or human recombinant GH (21 microg. kg(-1). h(-1); n = 8) was infused for 300 min, and insulin-stimulated glucose fluxes were estimated during the final 150-min period of hyperinsulinemic euglycemic clamps. In study 2, hyperinsulinemic euglycemic clamps were first conducted for 150 min (to raise plasma insulin and suppress FFA levels), and saline or GH (n = 7 for each) was subsequently infused for the following 300-min clamp period. In study 1, GH infusion in the basal state did not significantly alter plasma FFA or insulin levels. In contrast, GH infusion decreased insulin-stimulated glucose uptake, glycolysis, and glycogen synthesis by 32, 27, and 40%, respectively (P < 0.05). In study 2, GH infusion during hyperinsulinemic euglycemic clamps did not alter plasma FFA or insulin levels (P > 0.05). GH infusion had no effect on insulin-stimulated glucose uptake during the initial 150 min but eventually decreased insulin-stimulated glucose uptake by 37% (P < 0. 05), similar to the results in study 1. These data indicate that GH induces peripheral insulin resistance independent of plasma FFA and insulin levels. The induction of insulin resistance was preceded by suppression of glycogen synthesis, consistent with the hypothesis that metabolic impairment precedes and causes development of peripheral insulin resistance.