Three-dimensional isotropic fast spin-echo MR lymphangiography of T1-weighted and intermediate-weighted pulse sequences in patients with lymphoedema.

AIM: To evaluate the feasibility of magnetic resonance (MR) lymphangiography acquired using three-dimensional (3D) isotropic T1-weighted fast spin-echo (FSE) and 3D isotropic intermediate-weighted FSE sequences, as the new method of MR lymphangiography, and to compare the results of these two methods in patients with lymphoedema. MATERIALS AND METHODS: Thirty-three extremities of 27 patients with primary or secondary lymphoedema and who had undergone radionuclide lymphoscintigraphy and MR lymphangiography with 3D isotropic T1-weighted FSE and 3D isotropic intermediate-weighted FSE were included in the study. The results of both imaging techniques were independently reviewed by two readers in consensus who rated the lymphatic drainage pattern, the quality of the depiction of lymphatic vessels and lymph nodes, and the level of lymph vessel enhancement. The assessment scores of each imaging sequence were compared using the Wilcoxon signed-rank test. The results were expressed as means with standard deviations. RESULTS: More lymphatic vessels were visualised on T1-weighted FSE than on intermediate-weighted FSE (p<0.001). As more lymphatic vessels were detected on T1-weighted FSE, the per-extremity grade of the lymphatic drainage pattern was higher (p=0.046) and the visible levels of lymph-vessel enhancement were also significantly higher (p=0.004) on the T1-weighted FSE sequence, whereas the conspicuity of lymph nodes was superior on intermediate-weighted FSE (p=0.004). CONCLUSION: MR lymphangiography using the 3D FSE pulse sequence is a feasible and noticeable new technique of MR lymphangiography. Between the two applicable protocols used, T1-weighted FSE provided better information regarding lymphatic vessels and their drainage, whereas intermediate-weighted FSE has the advantage of depicting lymph nodes in lymphoedematous extremities.

Low pulmonary function is related with a high risk of sarcopenia in community-dwelling older adults: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011.

UNLABELLED: Sarcopenia is the age-related reduction of skeletal muscle mass in older individuals. Respiratory muscle strength may be related to skeletal muscle mass and, thus, the present study attempted to estimate the risk of sarcopenia relative to decreased pulmonary function. The present findings demonstrated that low pulmonary function was associated with low muscle mass in community-dwelling older adults. INTRODUCTION: Lean body mass is related to pulmonary function in patients with chronic obstructive pulmonary disease (COPD). However, the relationship between muscle mass and pulmonary function in healthy older adults has yet to be clarified. Thus, the present study investigated the association of pulmonary function with muscle mass in an older community-dwelling Korean population. METHODS: This study included 463 disease-free subjects over 65 years of age who underwent anthropometric measurements, laboratory tests, spirometry, and the estimation of appendicular skeletal muscle (ASM) mass in the 2008-2011 Korea National Health and Nutrition Examination Survey (KNHANES). Low muscle mass was defined as the value of ASM divided by height squared (ASM/height(2)) that was less than two standard deviations (SD) below the sex-specific mean of the young reference group. RESULTS: Forced expiratory volume in 1 s (FEV1[L]) and forced vital capacity (FVC[L]) were positively correlated with ASM/height(2) in males (p < 0.001 and p = 0.001, respectively) but not in females (p = 0.360 and p = 0.779, respectively). A univariate logistic regression analysis revealed that males with low FEV1 or FVC were more likely to have low muscle mass (odds ratio [OR] = 3.11, 95% confidence interval [CI] 1.62-5.99 for FEV1; OR = 1.99, 95% CI 1.13-3.53 for FVC); similar results were found for females, but the significance was lower (OR = 11.37, 95% CI 0.97-132.91 for FEV1; OR = 7.31, 95% CI 1.25-42.74 for FVC). After adjusting for age, smoking, and moderate physical activity, a low FEV1 value was associated with low muscle mass in both males (OR = 2.90, 95% CI 1.50-5.63) and females (OR = 9.15, 95% CI 1.53-54.77). CONCLUSIONS: Using nationally representative data from the 2008-2011 KNHANES, low pulmonary function was found to be associated with low muscle mass in community-dwelling older Korean adults.

Correlation of diffusion tensor imaging and phase-contrast MR with clinical parameters of cervical spinal cord injuries.

STUDY DESIGN: This is a cross-sectional study. OBJECTIVES: The goal of this study was to characterize the diffusion properties across segments of the spinal cord and peak cerebrospinal fluid (CSF) velocities in the stenotic spinal canal, and to determine the correlation between these properties and clinical and electrophysiological parameters in patients with cervical spinal cord injury (SCI). SETTING: This study was conducted in the University teaching hospital. METHODS: The study involved 17 patients with cervical SCI. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the spinal cord and peak systolic and diastolic velocities of CSF were measured at the level of maximum compression (region 1) and at the levels above (region 2) and below (region 3) the level of injury with no signal change in conventional magnetic resonance imaging. Neurological and electrophysiological parameters were measured, including American Spinal Injury Association (ASIA) Impairment Scale (AIS), ASIA motor score, ASIA sensory score, Modified Barthel Index, Spinal Cord Independence Measure III (SCIM III), somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP). RESULTS: The ADC was significantly higher and the FA was significantly lower in regions 1, 2 and 3 of the SCI patients than in the normal controls (P<0.05 each). FA of the level below correlated with AIS, ASIA sensory score and SCIM III score, and FA of the level above correlated with SSEP latencies and MEP amplitudes (P<0.05 each). The reductions in FA correlated with CSF flow, functional measurements and evoked potentials. CONCLUSIONS: Diffusion tensor imaging can be used to quantify the proximal and distal extents of spinal cord damage. Reductions in FA were correlated with CSF flow, functional measurements and evoked potentials.

The relationship between pulmonary function and bone mineral density in healthy nonsmoking women: the Korean National Health and Nutrition Examination Survey (KNHANES) 2010.

UNLABELLED: The aim of this study was to examine the association between pulmonary function and bone mineral density (BMD) in subjects who had never smoked. Pulmonary function was associated with BMD in premenopausal, but not postmenopausal, women. INTRODUCTION: It has been reported that low bone mass is common in patients with pulmonary disorders such as chronic obstructive pulmonary disease. However, in healthy nonsmoking women, the relationship between bone mass and pulmonary function has yet to be clarified. The object of this study was to determine whether pulmonary function is related to BMD in healthy nonsmoking women based on menopausal status. METHODS: This study was a cross-sectional study based on data obtained from the Korean National Health and Nutrition Examination Survey (KNHANES), a nationwide representative survey conducted by the Korean Ministry of Health and Welfare in 2010. This study included 456 subjects who had never smoked and analyzed data concerning pulmonary function and BMD. RESULTS: Functional vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were correlated with BMD at lumbar spine, femur neck (FN), and total hip in premenopausal women (p = 0.030, p = 0.003, p = 0.019, respectively, for FVC; p = 0.015, p = 0.006, p = 0.059, respectively, for FEV1). However, FVC and FEV1 were only correlated with BMD at FN in postmenopausal women (p = 0.003 for FVC; p = 0.006 for FEV1). Body mass index (BMI), FVC, and FEV1 were significantly related with BMD at FN, even after adjusting for age and other confounding factors (ß = 0.334, p < 0.001; ß = 0.145, p = 0.017; and ß = 0.129, p = 0.037, respectively) in premenopausal women. However, only age and BMI were correlated with BMD at FN (ß = -0.268, p = 0.001 and ß = 0.384, p > 0.001) in postmenopausal women after adjusting for confounding factors. CONCLUSIONS: Pulmonary function, including FVC and FEV1 are associated with BMD at FN in healthy nonsmoking premenopausal women but not in postmenopausal women.

Dexmedetomidine does not reduce emergence agitation in adults following orthognathic surgery.

BACKGROUND: Patients undergoing orthognathic surgery are at high risk of developing emergence agitation. We hypothesised that a single-dose of dexmedetomidine would reduce emergence agitation in adults with nasotracheal intubation after orthognathic surgery. METHODS: Seventy adults (20-45 years old) undergoing orthognathic surgery were randomly assigned to two groups. Patients received intravenous dexmedetomidine 1 µg/kg (dex group) or normal saline (control group) for 10 min at the end of surgery. Remifentanil was infused at 0.02 µg/kg/min during emergence in both groups. The severity of emergence agitation was assessed with the Richmond agitation-sedation scale. Cough, haemodynamic and respiratory profiles, pain, and time to eye opening were evaluated. RESULTS: The incidence of emergence agitation was not different between dex group and control group (38% vs. 47%, P = 0.45). However, severe cough during emergence was reduced in the dex group (P = 0.04). Tachycardia during emergence and recovery phases was attenuated in the dex group. The verbal numeric rating of pain was lower in the dex group. There were no differences in respiratory rate between the two groups. Time to eye opening was prolonged in the dex group. CONCLUSION: The addition of a single dose of dexmedetomidine (1 µg/kg) to low-dose remifentanil infusion did not attenuate emergence agitation in intubated patients after orthognathic surgery compared with low-dose remifentanil infusion alone. However, single-dose dexmedetomidine suppressed coughing, haemodynamic changes, and pain during emergence and recovery phases, without respiratory depression. Delayed awakening might be associated with this treatment.

Factors associated with early onset post-traumatic syringomyelia.

STUDY DESIGN: Retrospective study. OBJECTIVES: To identify factors associated with the development of early onset post-traumatic syringomyelia within 5 years of spinal cord injury. SETTING: Department of Rehabilitation Medicine, Pusan National University School of Medicine, Korea. METHODS: We retrospectively examined the records of 502 patients with traumatic cervical or thoracic spinal cord injury who underwent follow-up magnetic resonance imaging (MRI) examinations more than once a year for at least 5 years. Patients were assessed in terms of the neurological level of injury, the severity of initial spinal cord injury, the use of surgery and the extent of spinal canal involvement. The latter was evaluated by calculating the shortest antero-posterior diameter of the injured vertebral canal and the spinal reserve capacity as shown on MRI at the time of trauma onset and at the time of diagnosis of syringomyelia. RESULTS: Syringomyelia developed within 5 years in 37 (7.3%) of the 502 patients. The mean age of these 37 patients was 44.6 years (range, 17-67 years) and the mean interval from spinal cord injury to onset of syringomyelia was 38.8 months (range, 2-54 months). The development of post-traumatic syringomyelia within 5 years was not significantly related to the severity or level of injury, the use of spinal surgery or the extent of spinal canal encroachment (P≥0.05 for each comparison). CONCLUSION: Early onset syringomyelia occurring within 5 years after spinal cord injury was not associated with neurological injury level, severity of injury, the use of spinal surgery or canal encroachment.

Differences in strategies for prevention of COVID-19 transmission in hospitals: nationwide survey results from the Republic of Korea.

BACKGROUND: Hospital infection control measures against coronavirus disease 2019 (COVID-19) are often based on expert discretion due to the lack of detailed guidelines. AIM: To survey the current strategies for preventing the transmission of COVID-19 in medical institutions. METHODS: Thirteen key issues related to the prevention of COVID-19 transmission within medical institutions were selected via discussion among infectious diseases specialists, and related critical questions were obtained following a review of national-level guidelines in government databases. Six hospitals had an open survey between 11th and 25th August 2020 to provide responses to these topics. An online questionnaire developed from these data was sent to infection control teams at 46 hospitals in South Korea between 31st January 2021 and 20th February 2021. FINDINGS: All 46 hospitals responded to the survey. All operated screening clinics, but 89.1% (41/46) allowed symptomatic patients without COVID-19-associated symptoms to visit general outpatient clinics. Most hospitals (87.2%, 34/39) conducted polymerase chain reaction (PCR) tests for all hospitalized patients. Of 35/46 (76.1%) hospitals with pre-emptive isolation policies for hospitalized patients, 31 (88.6%) released patients from isolation after a single negative PCR test, while most (76.9%, 20/26) allowed shared-room accommodation for patients meeting the national criteria for release from isolation despite positive PCR results with above cycle threshold values (34.6%, 9/26), or after a certain period that satisfied the national criteria (26.9%, 7/26). CONCLUSION: Individual hospitals in South Korea are currently relying on experience to frame relevant guidelines, and responded differently to some infection control issues on hospital settings during the COVID-19 pandemic.

Plasma adiponectin is associated with less atherogenic lipoprotein phenotype.

BACKGROUND AND AIMS: This study examined the relationships between plasma levels of adiponectin and the features of the atherogenic lipoprotein phenotype (ALP), including HDL subclasses. METHODS AND RESULTS: Blood lipids and apolipoproteins were measured in 293 healthy individuals. LDL particle size and HDL subspecies (HDL(2), HDL(3)) were measured using gradient gel electrophoresis. Plasma adiponectin levels were negatively correlated with levels of apoB (r=-0.199, p<0.001), TG (r=-0.262, p<0.001), and HOMA-IR (r=-0.323, p<0.001) and positively correlated with levels of apoAI (r=0.173, p=0.006), HDL-cholesterol (r=0.287, p<0.001), and LDL particle size (r=0.289, p<0.001). Multiple linear regression analysis revealed the relationship between plasma adiponectin and LDL particle size (p<0.05) was no longer significant after adjusting for plasma TG levels. However, adiponectin (p<0.005) together with apoAI and TG were independent factors for HDL-cholesterol. With regard to HDL subclasses, plasma adiponectin levels were positively correlated with HDL(2b) (r=0.204, p<0.001), HDL(2a) (r=0.132, p<0.05) and negatively with HDL(3a) (r=-0.128, p<0.05), HDL(3b) (r=-0.203, p<0.001), and HDL(3c) (r=-0.159, p<0.01). The relationship between circulating adiponectin and HDL(2) (HDL(2b)+HDL(2a)) was independent of apoB and TG levels (p<0.05), but not of apoAI and HOMA-IR. CONCLUSIONS: Our results show that circulating adiponectin is associated with reduced manifestations of ALP.

Longitudinal split of the posterior cruciate ligament: description of a new MR finding and evaluation of its potential clinical significance.

AIM: To evaluate the clinical significance of the intra-substance longitudinal split of the posterior cruciate ligament (LS-PCL) and to evaluate its potential clinical significance on MRI. MATERIALS AND METHODS: The databases of two centres were searched for LS-PCL, 6917 knee magnetic resonance imaging (MRI) examinations undertaken were retrospectively reviewed. LS-PCL was defined as increased signal intensity in a PCL in the longitudinal direction, but with an intact ligament outer surface on MRI. Twelve patients were enrolled in this study. Available arthroscopic results, degree of posterior knee instability, and changes in MRI findings, or the degree of instability during follow-up (FU), were reviewed from the patients medical records and via their MRI images. MRI images were reviewed by two musculoskeletal radiologists in consensus for presence and location of LS-PCL and any combined injuries: menisci lesions, ligament injuries, and bone marrow changes. RESULTS: Seven of 12 patients (58.3%) had morphological or functional evidence of PCL injury or insufficiency according to the change of posterior instability on FU stress testing (n=3), insufficiency during arthroscopy (n=2), or decreased extent and altered shape of the PCL split on the FU MRI (n=3). One patient revealed both change of posterior instability on FU stress testing and insufficiency during arthroscopy. Combined injuries were revealed in seven patients. Five patients had isolated LS-PCL: two patients underwent arthroscopic PCL reconstructions; and another three patients revealed knee instability on stress testing. CONCLUSION: Although LS-PCL has not been described before, it can be a type of partial tear of the PCL, which causes PCL insufficiency.

Effects of gonadotropins on in vitro maturation and of electrical stimulation on parthenogenesis of canine oocytes.

The objective of this study was to determine the effects of gonadotropins on in vitro maturation (IVM) and electrical stimulation on the parthenogenesis of canine oocytes. In experiment I, cumulus oocyte complexes were collected from ovaries at a random phase of the oestrus cycle and cultured on maturation medium treated with hCG or eCG for 48 or 72 h. There were no significant differences in the effects on the metaphase II (MII) rate between the hCG and eCG treatment groups over 48 h (5.4% vs 5.5%). The MII rate in the co-treatment group of hCG and eCG for 48 h was higher than in each hormone treated group (15.5%, p < 0.05). In experiment 2, the parthenogenetic effect on oocyte development, at various electrical field strengths (1.0, 1.5, 2.0 kV/cm DC) for 60 or 80 mus with a single DC pulse after IVM on the co-treatment of hCG and eCG, was examined. The rate of pronuclear formation (37.1%) in electrical activation at 1.5 kV/60 mus without cytochalasin B (CB) was higher than that of oocytes activated in the other groups (p < 0.05). However, we did not observe the cleavage stages. Also, CB did not influence parthenogenesis of canine oocytes. The results showed that the pronucleus formation rate, indicative of the parthenogenesis start point, could be increased by electrical stimulation. Therefore, these results can provide important data for the parthenogenesis of canine oocytes and suggest the probability of parthenogenesis in canines.

Chlorhexidine sensitivity in staphylococci isolated from patients with central line-associated bloodstream infection.

Since 2011, 2% chlorhexidine in 70% isopropyl alcohol (2% chlorhexidine tincture) has been widely used in Korea. To investigate changes in chlorhexidine sensitivity of staphylococci causing central line-associated bloodstream infections, 264 blood culture isolates from adult patients treated in intensive care units of five university hospitals between 2008 and 2016 were analysed. We observed no significant changes in chlorhexidine minimum inhibitory and bactericidal concentrations, or in the prevalence of resistance-associated genes before and after introduction of 2% chlorhexidine tincture. Thus, there was no evidence of increased resistance to chlorhexidine in staphylococci causing central line-associated bloodstream infections.

Diagnosis of Critical Illness Myopathy After Liver Transplantation and Muscle Condition Monitoring: A Case Report.

BACKGROUND: Intensive care unit-acquired weakness (ICUAW) can occur after liver transplantation. Early diagnosis of ICUAW and monitoring of muscle condition during rehabilitation are helpful in improving functional recovery. METHODS AND MATERIALS: A 47-year-old man with liver cirrhosis developed limb weakness after liver transplantation. The patient had a Medical Research Council sum score of 2 weeks post-liver transplantation with marked proximal limb weakness. Direct muscle stimulation was performed on the right tibialis anterior muscle; the nerve-to-muscle ratio of compound muscle action potentials was 0.96, which indicated critical illness myopathy. Fatigue analysis using surface electromyography was performed 4 times after liver transplantation. RESULTS AND CONCLUSIONS: The maximal voluntary contraction tended to increase during rehabilitation, whereas the percentage of maximal voluntary contraction tended to decrease, indicating that muscle strength was increased. The fatigue index gradually decreased, showing that muscle endurance had improved along with strength. Muscle fatigue can be evaluated during rehabilitation using surface electromyography to prevent damage of the impaired muscle and to control exercise intensity. Early diagnosis of ICUAW and evaluation of muscle fatigue during rehabilitation will ensure a better prognosis for patients with ICUAW.

Trends in device utilization ratios in intensive care units over 10-year period in South Korea: device utilization ratio as a new aspect of surveillance.

BACKGROUND: Device-associated infection (DAI) is an important issue related to patient safety. It is important to reduce unnecessary device utilization in order to decrease DAI rates. AIM: To investigate the time trend of device utilization ratios (DURs) of voluntarily participating hospitals, collected over a 10-year period through the Korean National Healthcare-associated Infections Surveillance System (KONIS). METHODS: DURs from 2006 to 2015 in 190 intensive care units (ICUs) participating in KONIS were included in this study. DURs were calculated as the ratio of device-days to patient-days. The pooled incidences of DAIs and DURs were calculated for each year of participation, and the year-wise trends were analysed. FINDINGS: Year-wise ventilator utilization ratio (V-DUR) increased significantly from 0.40 to 0.41 (F = 6.27, P < 0.01), urinary catheter utilization ratio (U-DUR) increased non-significantly from 0.83 to 0.84 (F = 1.66, P = 0.10), and C-line utilization ratio (CL-DUR) decreased non-significantly from 0.55 to 0.51 (F = 1.62, P = 0.11). In the subgroup analysis, 'medical ICU' (F = 2.79, P < 0.01) and 'hospital with >900 beds' (F = 3.07, P < 0.01) were associated with the significant increase in V-DUR. CONCLUSION: In Korea, V-DUR showed a significant, year-wise increasing trend. The trends for U-DUR and CL-DUR showed no significant decrease. Efforts are required to ensure the reduction of DURs.

Paget bone disease involving young adults in 3 generations of a Korean family.

Although the etiology of Paget bone disease (PBD) is unknown, increasing evidence implicates a "slow virus" infection of the skeleton, perhaps in genetically predisposed individuals. PBD is rare in Asia. We describe a Korean family with PBD. The propositus noticed bowed limbs at approximately 25 years of age. Radiologic studies made when he was 55 years old revealed essentially panostotic PBD. Serum alkaline phosphatase (ALP) activity and osteocalcin (OC) levels were markedly elevated. An iliac crest specimen showed classic histopathologic changes of PBD. Additionally, palpable swellings were first observed at age 45 years at his occiput, pubic ramus, ileum, and facial bones. They contained numerous multinucleated cells and were originally diagnosed as giant cell tumors. However, we found that, like osteoclasts, these cells expressed considerable tartrate-resistant acid phosphatase activity. These "extraskeletal osteoclastomas" resolved rapidly with dexamethasone treatment. Two daughters, 20- and 24-years-of-age, were discovered by study of his 5 children to have elevated serum ALP activity and OC levels and widespread PBD. Both women, however, are without palpable masses and are asymptomatic. The propositus' father, who died at age 55 years, had similar skeletal deformities beginning at age 20 years, but was not examined. Leukocytopenia was found in the 3 living family members with PBD. There was no evidence for linkage of the PBD to HLA loci. The condition appears to be transmitted as an autosomal dominant trait and is manifest in young adult life. Multicentric extraskeletal osteoclastomas with remarkable sensitivity to dexamethasone treatment appear to be another unusual feature of this family's disorder. In this family, the stimulus for PBD is so great that the PBD is apparent at an early age, affects essentially the entire skeleton, and leads to the formation or extension of osteoclast-like cells into nonosseous tissues (extraskeletal osteoclastomas). This 3-generation kindred in Korea, where PBD is rare, shows a strong clustering of PBD compatible with autosomal dominant inheritance. Leukocytopenia appears to distinguish affected family members, but any role for this abnormality in the pathogenesis of PBD is unclear. Our findings support a heritable diathesis for PBD, perhaps mediated by an immune deficiency.

Pharmacological preconditioning with low-dose cyclosporine or FK506 reduces subsequent ischemia/reperfusion injury in rat kidney.

BACKGROUND: Ischemia/reperfusion (I/R) injury in the early posttransplant period is closely associated with delayed recovery of graft function, increased acute rejection, and late allograft dysfunction. Pharmacological preconditioning with low-dose cyclosporine (CsA) or FK506 was performed to induce ischemic tolerance in rat kidney with I/R injury. METHODS: Low-dose CsA (3 mg/kg, administered i.v.) or FK506 (0.3 mg/kg i.v.) were used to induce ischemic tolerance in Sprague-Dawley rats, and the induction of heat shock protein (hsp) 70 by CsA or FK506 was evaluated overtime. Rats were pretreated with CsA or FK506 6 hr before I/R injury when hsp70 was maximally expressed, and were killed 24 hr later. The effect of pharmacological preconditioning on subsequent I/R injury was evaluated in terms of renal function, histopathology score, assays for apoptosis (DNA fragmentation analysis, TUNEL staining, expressions of pro-apoptotic genes, and caspase activity), and the expression of inflammatory cytokine genes (interleukin-1 and tumor necrosis factor-alpha). RESULTS: Preconditioning with low-dose CsA or FK506 significantly improved renal function and renal histology, compared to rats with I/R injury. Apoptotic cell death (typical DNA laddering and increased TUNEL-positive cells) in rat kidneys with I/R injury, was decreased by pretreatment with low-dose CsA or FK506. Increased expression of pro-apoptotic genes (Fas, Fas-ligand, caspase 1 and 3) and activated caspases in ischemic rat kidneys were decreased after CsA or FK506 pretreatment. CONCLUSIONS: Pretreatment with low-dose CsA or FK506 prevents subsequent I/R injury, and this effect may be related to the induction of hsp70. Pretreatment of renal donors with low-dose CsA or FK506 may result in an improvement in immediate posttransplant function.

Metabolite and light regulation of metabolism in plants: lessons from the study of a single biochemical pathway.

We are using molecular, biochemical, and genetic approaches to study the structural and regulatory genes controlling the assimilation of inorganic nitrogen into the amino acids glutamine, glutamate, aspartate and asparagine. These amino acids serve as the principal nitrogen-transport amino acids in most crop and higher plants including Arabidopsis thaliana. We have begun to investigate the regulatory mechanisms controlling nitrogen assimilation into these amino acids in plants using molecular and genetic approaches in Arabidopsis. The synthesis of the amide amino acids glutamine and asparagine is subject to tight regulation in response to environmental factors such as light and to metabolic factors such as sucrose and amino acids. For instance, light induces the expression of glutamine synthetase (GLN2) and represses expression of asparagine synthetase (ASN1) genes. This reciprocal regulation of GLN2 and ASN1 genes by light is reflected at the level of transcription and at the level of glutamine and asparagine biosynthesis. Moreover, we have shown that the regulation of these genes is also reciprocally controlled by both organic nitrogen and carbon metabolites. We have recently used a reverse genetic approach to study putative components of such metabolic sensing mechanisms in plants that may be conserved in evolution. These components include an Arabidopsis homolog for a glutamate receptor gene originally found in animal systems and a plant PII gene, which is a homolog of a component of the bacterial Ntr system. Based on our observations on the biology of both structural and regulatory genes of the nitrogen assimilatory pathway, we have developed a model for metabolic control of the genes involved in the nitrogen assimilatory pathway in plants.

Successful management with glue injection of arterial rupture seen during embolization of an arteriovenous malformation using a flow-directed catheter: a case report.

We present a case in which an arterial rupture occurring during embolization of an arteriovenous malformation of the left occipital lobe with a flow-directed microcatheter, was successfully sealed with a small amount of glue. We navigated a 1.8-Fr Magic catheter through the posterior cerebral artery, and during superselective test injection, extravasation was observed at the parieto-occipital branch. The catheter was not removed and the perforation site was successfully sealed with a small amount of glue injected through the same catheter. Prompt recognition and closure of the perforation site is essential for good prognosis.

Fibrous dysplasia with barely increased uptake on bone scan: a case report.

Fibrous dysplasia, in general, appears as an area of markedly increased uptake on bone scintigraphy. Therefore, the possibility of fibrous dysplasia is likely to be excluded when the lesion shows no or slightly increased uptake. The authors report a case of incidentally detected fibrous dysplasia that appeared as slightly increased uptake on bone scintigraphy and was found to harbor a bone infarction along with typical fibrous dysplasia by pathologic examination of a specimen sampled by curettage. Barely increased bone uptake in fibrous dysplasia may be associated with decreased vascularity and osteoblast activity of the lesion as a result of concurrent bone infarction. The authors suggest that not every case of fibrous dysplasia appears as an area of intensely increased uptake on a bone scan. Clinicians should be cautious in interpreting bone scans of radiographically indicated fibrous dysplasia.

Use of Tc-99m HMPAO leukocyte scans to evaluate bone infection: incremental value of additional SPECT images.

PURPOSE: In this study, the diagnostic value of Tc-99m hexamethylpropylene amine oxime (HMPAO) leukocyte scans and the role of additional SPECT in the diagnosis of bone infection were evaluated. MATERIALS AND METHODS: The Tc-99m HMPAO leukocyte scans of 37 patients with clinically suspected bone infection were reviewed. The patients were divided into two groups according to the presence of orthopedic implants. Early (4 to 6 hours) and delayed (18 to 20 hours) planar images and early SPECT images were obtained. The final diagnosis of infection was made based on the pathologic, bacteriologic, and surgical data and clinical follow-up. RESULTS: Group 1 (25 patients with orthopedic implants) included 15 true-positive, 1 false-negative, 7 true-negative, and 2 false-positive results. Group 2 (12 patients without orthopedic implants) included 7 true-positive, 1 false-negative, and 4 true-negative results. The overall sensitivity of the Tc-99m HMPAO leukocyte scan with SPECT to detect bone infection was 92%, with a specificity rate of 85%. (Group 1: sensitivity, 94%; specificity, 78%. Group 2: 88% and 100% sensitivity and specificity, respectively.) CONCLUSION: The Tc-99m HMPAO leukocyte scan is useful in the diagnosis of bone infection, regardless of the presence of orthopedic implants. The additional SPECT images may be helpful to localize the site of infection more accurately.