Clinical characteristics and outcomes of Clostridioides difficile infection in the intensive care unit: a KASID multi-centre study

BACKGROUND

Despite the growing clinical and economic burden of Clostridioides difficile infection (CDI), data on CDI in the intensive care unit (ICU) in the Asia-Pacific region are lacking.

METHODS

This retrospective study analysed 191 patients who were treated with CDI in the ICUs of three hospitals in South Korea from January 2017 to May 2021. Backward-stepwise multiple logistic regression was used to identify factors influencing the treatment response and mortality.

RESULTS

Fifty-eight patients (30.4%) were considered immunocompromised. The mean Charlson comorbidity index was 5.65 ± 2.39 (10-year survival rate: 21%), the APACHE II score was 20.86 ± 7.78 (mortality rate: 40%), the ATLAS score was 5.45 ± 1.59 (cure rate: 75%), and the SOFA score was 7.97 ± 4.03 (mortality rate: 21.5%). Fifty-eight (30.4%) of the CDI cases were severe and 40 (20.9%) were fulminant. Oral vancomycin or oral metronidazole was the most frequently first-line treatments (N = 57; 32.6%). The 10-day response rate was 59.7% and the eight-week overall mortality rate was 41.4%. Fulminant CDI (OR 0.230; 95% CI 0.085-0.623) and each one-unit increment in the SOFA score (OR 0.848; 95% CI 0.759-0.947) were associated with treatment failure. High APACHE II (OR 0.355; 95% CI 0.143-0.880) and SOFA (OR 0.164; 95% CI 0.061-0.441) scores were associated with higher mortality.

CONCLUSIONS

High-risk patients in the ICU had a higher mortality rate and a lower cure rate of CDI. Further research is required to provide more accurate prediction scoring systems and better clinical outcomes.

The 2019-2020 EURADOS WG10 and RENEB Field Test of Retrospective Dosimetry Methods in a Small-Scale Incident Involving Ionizing Radiation

With the use of ionizing radiation comes the risk of accidents and malevolent misuse. When unplanned exposures occur, there are several methods which can be used to retrospectively reconstruct individual radiation exposures; biological methods include analysis of aberrations and damage of chromosomes and DNA, while physical methods rely on luminescence (TL/OSL) or EPR signals. To ensure the quality and dependability of these methods, they should be evaluated under realistic exposure conditions. In 2019, EURADOS Working Group 10 and RENEB organized a field test with the purpose of evaluating retrospective dosimetry methods as carried out in potential real-life exposure scenarios. A 1.36 TBq 192Ir source was used to irradiate anthropomorphic phantoms in different geometries at doses of several Gy in an outdoor open-air geometry. Materials intended for accident dosimetry (including mobile phones and blood) were placed on the phantoms together with reference dosimeters (LiF, NaCl, glass). The objective was to estimate radiation exposures received by individuals as measured using blood and fortuitous materials, and to evaluate these methods by comparing the estimated doses to reference measurements and Monte Carlo simulations. Herein we describe the overall planning, goals, execution and preliminary outcomes of the 2019 field test. Such field tests are essential for the development of new and existing methods. The outputs from this field test include useful experience in terms of planning and execution of future exercises, with respect to time management, radiation protection, and reference dosimetry to be considered to obtain relevant data for analysis.

Microspinning: Local Surface Mixing via Rotation of Magnetic Microparticles for Efficient Small-Volume Bioassays

The need for high-throughput screening has led to the miniaturization of the reaction volume of the chamber in bioassays. As the reactor gets smaller, surface tension dominates the gravitational or inertial force, and mixing efficiency decreases in small-scale reactions. Because passive mixing by simple diffusion in tens of microliter-scale volumes takes a long time, active mixing is needed. Here, we report an efficient micromixing method using magnetically rotating microparticles with patterned magnetization induced by magnetic nanoparticle chains. Because the microparticles have magnetization patterning due to fabrication with magnetic nanoparticle chains, the microparticles can rotate along the external rotating magnetic field, causing micromixing. We validated the reaction efficiency by comparing this micromixing method with other mixing methods such as simple diffusion and the use of a rocking shaker at various working volumes. This method has the potential to be widely utilized in suspension assay technology as an efficient mixing strategy.

Optimized liquid chromatography-tandem mass spectrometry for Otaplimastat quantification in rat plasma and brain tissue

An optimized liquid chromatography-tandem mass spectrometry method for simple and sensitive quantification of Otaplimastat in rat plasma and brain tissue was developed and validated. Protein precipitation with acetonitrile was selected for sample preparation method based on recovery and matrix effect. The chromatographic separation of the sample was performed on a reverse-phase AQ column with an isocratic mobile phase consisting of 10 mM ammonium acetate (pH 4.0) and acetonitrile (50:50, v/v). The analyte was quantified by multiple reaction monitoring with a Waters Quattro micro™ API mass spectrometer. The lower limits of quantification were 20 ng/mL in plasma and 2 ng/g in brain, with the relative standard deviation % of 7.6 and 8.0% for plasma and brain samples, respectively. Acceptable intra-day and inter-day precisions and accuracies were obtained. Otaplimastat was sufficiently stable under all relevant analytical conditions, including a temperature of 4°C for 24 hr, room temperature 20°C for 24 hr, -80°C for 10 days and three freeze-thaw cycles (each at -80°C for 24 hr), for rat plasma and brain tissue. The validated method was successfully used to measure Otaplimastat concentrations in rat plasma and brain samples.

The level of intracellular tacrolimus in T cell is affected by CD44+ABCB1+activities triggered by inflammation

Rejection is an important issue in kidney transplant. Although with adequate trough level of tacrolimus, acute rejection occurs, and we are focused on these cases. We hypothesized that the lower concentration of tacrolimus in the peripheral blood mononuclear cell would be a cause of rejection; in this regard, we describe ABCB1, which regulates intracellular concentration of tacrolimus. The effect of inflammation on the intracellular concentration of tacrolimus was evaluated, as was the association between that concentration and ABCB1 and CD44 activities. Seven kidney recipients experiencing acute rejection were prospectively enrolled. Both the whole blood concentration of tacrolimus and intracellular concentration of tacrolimus were measured at the time of enrollment and after stabilization. A human T lymphoblastoid cell line (Jurkat T cell) was treated with various concentrations of tacrolimus for 21 h and then stimulated for 3 h. The levels of mRNA interleukin-2, interleukin-8, and interferon-γ decreased dose dependently by tacrolimus. Furthermore, a fluorescence-activated cell sorter was used to count cells expressing CD44 and ABCB1; changes in intracellular concentration of tacrolimus were explored after tacrolimus treatment and stimulation. Also, B6 splenocytes were tested in the same manner as previous Jurkat T cell experiments. The tacrolimus ratio of three patients was lower at the time of acute rejection than when patients were stabilized. In vitro, the intracellular concentration of tacrolimus decreased after stimulation. Under the same conditions, CD44+ABCB1+cells increased in proportion on tacrolimus treatment and stimulation. This work supports the hypothesis that inflammation reduces the intracellular tacrolimus level, possibly via drug efflux mediated by CD44+ABCB1+and inflammation could lead to acute rejection.

Indoxyl sulfate (IS)-mediated immune dysfunction provokes endothelial damage in patients with end-stage renal disease (ESRD)

Progressive renal failure causes uremia-related immune dysfunction, which features a chronic inflammatory milieu. Given the central role of end-stage renal disease (ESRD)-related immune dysfunction in the pathogenesis of cardiovascular diseases (CVDs), much attention has been focused on how uremic toxins affect cellular immunity and the mechanisms underlying pathogenesis of atherosclerosis in ESRD patients. Here, we investigated the characteristics of monocytes and CD4+ T cells in ESRD patients and the immune responses induced by indoxyl sulfate (IS), a key uremic toxin, in order to explore the pathogenic effects of these cells on vascular endothelial cells. In ESRD patients, monocytes respond to IS through the aryl hydrocarbon receptor (AhR) and consequently produce increased levels of TNF-α. Upon stimulation with TNF-α, human vascular endothelial cells produce copious amounts of CX3CL1, a chemokine ligand of CX3CR1 that is highly expressed on CD4+CD28-T cells, the predominantly expanded cell type in ESRD patients. A migration assay showed that CD4+CD28- T cells were preferentially recruited by CX3CL1. Moreover, activated CD4+CD28- T cells exhibited cytotoxic capability allowing for the induction of apoptosis in HUVECs. Our findings suggest that in ESRD, IS-mediated immune dysfunction may cause vascular endothelial cell damage and thus, this toxin plays a pivotal role in the pathogenesis of CVD.

Who may benefit from robotic gastrectomy?: A subgroup analysis of multicenter prospective comparative study data on robotic versus laparoscopic gastrectomy

AIMS

Robotic gastrectomy for gastric cancer has been proven to be a feasible and safe minimally invasive procedure. However, our previous multicenter prospective study indicated that robotic gastrectomy is not superior to laparoscopic gastrectomy. This study aimed to identify which subgroups of patients would benefit from robotic gastrectomy rather than from conventional laparoscopic gastrectomy.

METHODS

A prospective multicenter comparative study comparing laparoscopic and robotic gastrectomy was previously conducted. We divided the patients into subgroups according to obesity, type of gastrectomy performed, and extent of lymph node dissection. Surgical outcomes were compared between the robotic and laparoscopic groups in each subgroup.

RESULTS

A total of 434 patients were enrolled into the robotic (n = 223) and laparoscopic (n = 211) surgery groups. According to obesity and gastrectomy type, there was no difference in the estimated blood loss (EBL), number of retrieved lymph nodes, complication rate, open conversion rate, and the length of hospital stay between the robotic and laparoscopic groups. According to the extent of lymph node dissection, the robotic group showed a significantly lower EBL than did the laparoscopic group after D2 dissection (P = 0.021), while there was no difference in EBL in patients that did not undergo D2 dissection (P = 0.365).

CONCLUSION

Patients with gastric cancer undergoing D2 lymph node dissection can benefit from less blood loss when a robotic surgery system is used.

Monitoring the Intracellular Tacrolimus Concentration in Kidney Transplant Recipients with Stable Graft Function

Although monitoring the intracellular concentration of immunosuppressive agents may be a promising approach to individualizing the therapy after organ transplantation, additional studies on this issue are needed prior to its clinical approval. We investigated the relationship between intracellular and whole blood concentrations of tacrolimus (IC-TAC and WB-TAC, respectively), the factors affecting this relationship, and the risk of rejection based upon IC-TAC in stable kidney recipients. Both IC-TAC and WB-TAC were measured simultaneously in 213 kidney recipients with stable graft function using LC-MS/MS. The tacrolimus ratio was defined as IC-TAC per WB-TAC. The genetic polymorphism of ABCB1 gene and flow cytometric analyses were conducted to probe the correlation between tacrolimus concentrations and the immunoreactivity status as a potential risk of rejection, respectively. The correlation between IC-TAC and WB-TAC was relatively linear (r = 0.67; P<0.001). The factors affecting the tacrolimus ratio were sex, hematocrit, and the transplant duration, as follows: a high tacrolimus ratio was noted in female patients, patients with a low hematocrit, and patients with a short transplant period. However, the tacrolimus ratio did not reflect the prior clinical outcomes (e.g., rejection) or the genetic polymorphism of ABCB1. After stimulation with phorbol-12-myristate 13-acetate and ionomycin, the proportion of T cells producing interferon-gamma or interleukin-2 was higher in the low-IC-TAC group than in the high-IC-TAC group. Further studies are required to evaluate the value of the intracellular tacrolimus concentrations in several clinical settings, such as rejection, infection, and drug toxicity.

Coronary artery disease in a large renal transplant population: implications for management

Coronary artery disease (CAD) accounts for approximately one-half of the sizable mortality in patients with end-stage renal disease who have undergone transplantation. The study was a retrospective review of 1460 patients who underwent renal transplantation at the Mount Sinai Medical Center from January 1, 2000 to October 31, 2009. Noninvasive stress testing was performed in 848 patients (88.1%) with 278 patients (32.8%) having abnormal results. Cardiac catheterization was performed in 357 patients (37.1%) and of these, 212 patients had obstructive disease (59.4%). At 5 years posttransplant, there was no statistically significant difference between those with nonobstructive CAD and those who required percutaneous or surgical interventions (adjusted hazard ratio [aHR], 1.243; CI 95%, 0.513-3.010; p = 0.630). Those with medically managed obstructive CAD had significantly higher rates of death at the 5-year period when compared to those who received percutaneous intervention (aHR, 3.792; CI 95%, 1.320-10.895; p = 0.013) or those who received coronary artery bypass grafting (aHR, 6.691; CI 95%, 1.200-37.323). Because noninvasive imaging is poorly predictive of coronary disease in this high-risk population, an anatomic diagnosis is recommended. Revascularization may result in improved long-term outcomes.

Linear stability analysis on the onset of Soret-driven motion in a nanoparticles suspension

The onset of Soret-driven instability in binary mixture heated from above is analysed using the linear stability theory. The horizontal fluid layer placed between two plates is in a thermally stable state but the Soret diffusion can induce buoyancy-driven convection in the case of a negative Soret coefficient. It is well known that convective motion sets in from both boundaries if the Rayleigh number exceeds its critical value. For the case of highly unstable density stratification the buoyancy-driven motion sets in during the transient diffusion stage. The new stability equations are derived and are solved analytically and numerically. Here the stability limits which are related to the onset time of instabilities and wave number are presented as a function of the Rayleigh number, Lewis number and the separation ratio. The present stability criteria are compared with the existing experimental data.

Survival rate of H5N1 highly pathogenic avian influenza viruses at different temperatures

The survival rate of Korean H5N1 highly pathogenic avian influenza (HPAI) viruses was investigated at different temperatures under the laboratory conditions. The estimated survival days for a starting viral concentration of 10(6.5) 50% egg infectious dose/0.1 mL were 930, 1,042, and 3,213 d at 4 degrees C; 226, 232, and 293 d at 20 degrees C; and 51, 55, and 58 d at 30 degrees C for A/chicken/Korea/ES/03, A/chicken/Korea/IS/06, and A/chicken/Korea/Gimje/08 (Gimje/08) viruses, respectively. The stability of the Gimje/08 virus was statistically significant compared with the other 2 viruses except for the data between Gimje/08 and A/chicken/Korea/IS/06 virus at 30 degrees C. This result indicated that the survival rate of 3 Korean HPAI viruses is different at various temperatures, which might have partially influenced the large scale of HPAI outbreak in Korea in 2008.

Comparison of anaesthetic and cardiorespiratory effects of xylazine or medetomidine in combination with tiletamine/zolazepam in pigs

Two different combinations of anaesthetics were evaluated and compared in a prospective randomised crossover experimental study in pigs. One of the two combinations was administered intramuscularly to each of six Landrace x Yorkshire mixed-breed pigs. The combinations were: 2.2 mg/kg xylazine and 4.4 mg/kg tiletamine/zolazepam (2.2 mg/kg tiletamine plus 2.2 mg/kg zolazepam) (XTZ); and 0.04 mg/kg medetomidine and 4.4 mg/kg tiletamine/zolazepam (MTZ). The anaesthesia and recovery times, score for anaesthetic effect and cardiopulmonary parameters were recorded for each pig. Anaesthesia was successfully induced in all of the pigs. Both drug combinations provided smooth induction and good immobilisation, and their anaesthetic effects were similar. In both treatment groups, the mean heart rate decreased significantly five minutes after the drugs were administered and remained consistent for 70 minutes, with no significant difference between the XTZ and MTZ groups. However, there were differences in cardiopulmonary effects between the groups. The arterial pressure was significantly higher in the MTZ group than in the XTZ group. The initial hypertension associated with medetomidine was more marked than the initial hypertension associated with xylazine. Arterial oxygen partial pressure and arterial oxygen saturation decreased significantly from baseline in both groups. The respiratory rates and levels of blood gases were similar in both groups. Hypoventilation and hypoxaemia were observed in both groups. The scores for anaesthetic effect, induction time, anaesthesia time and recovery times were similar in the two groups.

The susceptibility of magpies to a highly pathogenic avian influenza virus subtype H5N1

Korean wild magpies (Pica pica sericea) were intranasally inoculated with highly pathogenic avian influenza (A/Chicken/Korea/ES/03 virus) (H5N1), which was classified as clade 2.5. We estimated viral replication, death after infection, and histology and immunohistochemistry. This species was highly susceptible to severe infection; 100% of birds died within 5 to 8 d. The virus was detected from oropharyngeal (1 to 5 d postinfection) and cloacal (3 to 5 d postinfection) swabs from infected magpies. At necropsy, the prominent lesions were coalescing necrosis of the pancreas with enlargement of livers and spleens. Microscopically, pancreas, brain, heart, adrenal gland, and kidney were most consistently affected with necrotic and inflammatory changes, and viral antigen was frequently demonstrated in the parenchyma of these organs. As a result, Korean wild magpies were very susceptible to avian influenza (H5N1) virus.

Development of a stabilizer for lyophilization of an attenuated duck viral hepatitis vaccine

The live attenuated vaccine against duck viral hepatitis currently available in Korea requires special freezers for storage and transportation with extra costs involved. The development of a lyophilization stabilizer for live attenuated duck viral hepatitis virus (DHV) vaccines, therefore, has been highly recommended for the wider application of the vaccines. Four conventional vaccine stabilizer formulations containing a disaccharide, such as lactose, trehalose, or sucrose, and new formulations containing sorbitol were tested for their efficacy in stabilizing a new attenuated DHV type 3 vaccine candidate under different storage temperatures, 4 and 37 degrees C. The vaccine virus and each stabilizer formulation were combined and submitted to lyophilization and the viability of the virus was measured in 7-d-old specific-pathogen-free chicken embryos by determining the 50% egg lethal dose. Stabilizer formulations containing 2, 4, or 8% sorbitol preserved the viability of the vaccine virus much better than the other stabilizer formulations and 2% sorbitol was the optimal concentration in a standard stabilizing buffer, phosphate glutamate gelatin (0.0038 M KH2PO4, 0.0071 M K2HPO4, 0.0049 M monosodium L-glutamate, and 0.5% gelatin). The results demonstrate that the stabilizer formulation containing 2% sorbitol and 0.5% gelatin can be used for convenient storage and transportation of live DHV vaccines.

Self-assembled growth and luminescence of crystalline Si/SiOx core-shell nanowires

Crystalline Si/SiOx core/shell nanowires (NWs) are self-assembled by annealing Ni-coated hydrogenated Si-rich SiOx (SRO:H) films at 1100 degrees C in the presence of Si powder. Plasma-enhanced chemical vapor deposition is used to grow 100 nm SRO:H thin films with varying silicon concentration (n(Si)). The NWs vary from SiOx nanowires to Si/SiOx core/shell structures depending on the composition of the SRO:H substrate, with the fraction of core/shell structures increasing with increasing Si concentration. As n(Si) increases from 37 to 43 at.%, the average diameter of the NWs also increases from 48 to 157 nm. A growth model based on the diffusion-assisted vapor-liquid-solid mechanism is proposed to explain how the core/shell structures are self-assembled. Photoluminescence (PL) spectra of the individual NWs have two major emission bands in the near UV (381 nm) and blue (423 nm) ranges at n(Si) = 43 at.%, named as UV and BL PL bands, respectively. In contrast, only the BL PL band is observed at n(Si) < or = 39 at.%. These results suggest that the BL and UV PL bands can be attributed to the defect states in the SiOx shell and at the Si core/SiOx shell interface, respectively, and that the BL band is closely related to the growth process of the NWs.

Multicentre study of the safety of laparoscopic subtotal gastrectomy for gastric cancer in the elderly

BACKGROUND

The aim of this study was to assess the safety and short-term value of laparoscopic gastrectomy in the elderly with gastric cancer compared with a younger cohort.

METHODS

Data on all patients with gastric cancer undergoing laparoscopic gastrectomy at ten institutions in Korea between May 1998 and December 2005 were collected. Patients under the age of 45 years and those undergoing total gastrectomy, proximal gastrectomy and pylorus-preserving gastrectomy were excluded. An analysis of clinicopathological data for patients aged 45-69 years (average-age group) and those aged 70 years or more (elderly group) was undertaken.

RESULTS

Co-morbidity was more common and postoperative hospital stay was longer in elderly patients. Pre-existing pulmonary and cardiovascular disease in the elderly contributed to respiratory dysfunction and intraperitoneal complications respectively. Tumour size and location, stage, methods of reconstruction and the number of combined operations were similar in the two groups. There were no significant differences in postoperative morbidity or mortality.

CONCLUSION

Although elderly patients had greater co-morbidity, laparoscopic gastrectomy was a safe treatment for gastric cancer in this age group.

Prognostic value of expression of ERCC1, thymidylate synthase, and glutathione S-transferase P1 for 5-fluorouracil/oxaliplatin chemotherapy in advanced gastric cancer

BACKGROUND

The aim of this study was to determine whether expressions of the excision repair cross-complementing (ERCC1), thymidylate synthase (TS), and glutathione S-transferase P1 (GSTP1) predict clinical outcome in patients with advanced gastric cancer treated with fluorouracil (5-fluorouracil)/oxaliplatin chemotherapy.

PATIENTS AND METHODS

The study population consisted of 64 advanced gastric cancer patients (median age 51 years). Patients were treated with oxaliplatin 85 mg/m(2) as a 2-h infusion at day 1 plus leucovorin 20 mg/m(2) over 10 min, followed by 5-FU bolus 400 mg/m(2) and 22-h continuous infusion of 600 mg/m(2) at days 1-2. Treatment was repeated in 2-week intervals. The expressions of ERCC1, TS, and GSTP1 of primary tumors were examined by immunohistochemistry.

RESULTS

The positive rates of ERCC1, TS, and GSTP1 were 70.3%, 29.7%, and 50.0%, respectively. The patients without ERCC1 expression were more likely to respond to chemotherapy (P = 0.045). There were no significant differences between response and TS or GSTP1 expression pattern (P = 0.813, P = 0.305, respectively). Median overall survival (OS) was significantly longer in patients without ERCC1 expression (P = 0.0396). TS or GSTP1 expression were not related to survival (P = 0.4578, P = 0.8121, respectively). Multivariate analysis revealed that ERCC1 expression significantly impacted on OS (hazard ratio 1.92, P = 0.037).

CONCLUSION

Immunohistochemical studies for ERCC1 may be useful in prediction of the clinical outcome in advanced gastric cancer patients treated with 5-FU and oxaliplatin.

Delayed occurrence of intracranial supratentorial chondroma following compound depressed skull fracture

We describe an exceptional case of a frontal convexity chondroma arising at the site of a compound depressed skull fracture operated on 12 years earlier. We conclude that intracranial chondroma should be included in the differential diagnosis of a calcified mass for the patients who had had a compound, depressed skull fracture along the suture line, especially in cases of dural laceration by the fragmented bone.

Study on size distribution of total aerosol and water-soluble ions during an Asian dust storm event at Jeju Island, Korea

Soil dust particles transported from loess regions of the Asian continent, called Asian dust, highly influences the air quality of north-eastern Asia and the northern Pacific Ocean. In order to investigate the effects of these dust storms on the chemical composition of atmospheric aerosol particles with different size, measurements of size distributions of total aerosol and major ion species were carried out on Jeju Island, Korea during April 2001. Juju Island was chosen for the study because the levels of emissions of anthropogenic air pollutants are very low. A 5-stage cascade impactor was used to sample size-fractionated aerosol particles. Samples were analyzed for major water-soluble ions using Dionex DX-120 ion chromatograph. The average mass concentration of total aerosol was found to be 24.4 and 108.3 microg m(-3) for non-Asian dust and Asian dust periods, respectively. The total aerosol size distribution, measured during the non-Asian dust period, was bimodal, whereas the coarse particles dominated the size distribution of total aerosol during the Asian dust period. It was found that SO4(2-), NH4+ and K+ were mainly distributed in fine particles, while Cl-, NO3-, Na+, Mg2+ and Ca2+ were in coarse particles. Although SO4(2-) was mainly distributed in fine particles, during the Asian dust period, the concentrations in coarse particles were significantly increased. This indicates heterogeneous oxidation of SO2 on wet surfaces of basic soil dust particles. The NH4+ was found to exist as (NH4)2SO4 in fine particles, with a molar ratio of NH4+ to SO4(2-) of 2.37 and 1.52 for non-Asian dust and Asian dust periods, respectively. Taking into account the proximity of the sampling site to the sea, and the observed chloride depletion, coarse mode nitrate, during the non-Asian dust period, is assumed to originate from the reaction of nitric acid with sodium chloride on the surfaces of sea-salt particles although the chloride depletion was not shown to be large enough to prove this assumption. During the Asian dust period, however, chloride depletion was much smaller, indicating coarse nitrate particles were mainly produced by the reaction of nitric acid with surfaces of basic soil particles. Most chloride and sodium components were shown to originate from sea-salt particles. Asian dust aerosols, arriving at Jeju Island, contained considerable amounts of sea-salt particles as they passed over the Yellow Sea. Ca2+ was shown to be the most abundant species in Asian dust particles.

Clinics in diagnostic imaging (80). Ileocolic intussusception

Intussusception is a common but life threatening gastrointestinal emergency that occurs in the infant or young child. A three-year-old boy presenting with abdominal pain and vomiting was diagnosed to have the target sign on ultrasonography. An ileocolic intussusception was initially reduced using air enema. Recurrent intussusception 12 hours later was reduced by barium enema. In the proper hands, ultrasonography has a high diagnostic accuracy rate for intussusception. For treatment, air enema is usually perferred to barium enema. Air enema is a safe, rapid, and clean procedure that has been shown to achieve a high reduction rate, comparable to that of barium enema. Ultrasonographically-guided hydrostatic reduction of intussusception has also been recently described and is an effective alternative.

Regional cerebral blood flow changes in patients with intractable obsessive compulsive disorders treated by limbic leukotomy

The object of this study is to assess the changes in regional cerebral blood flow (rCBF) following stereotactic limbic leukotomy in patients with medically intractable Obsessive-Compulsive Disorder (OCD). Technetium-99-Hexa Methyl Propylene Amine Oxime (99mTc-HMPAO) Single Photon Emission Computed Tomography (SPECT) data obtained before and after limbic leukotomy were subjected to image fusion with MRI images. Eight samples were obtained from healthy voluteers. After localization of the ROI (Region Of Interest) in anatomical area, rCBF measurements were obtained by METLAB. The results of this study show a change of rCBF following limbic leukotomy in intractable OCD. Postoperative 99mTc-HMPAO SPECT findings implicate the medial frontal cortex, cingulate and striatum, which culd be linked to limbic leukotomy that blocks the functional connection of corticolimbic loop.

Fenofibrate lowers abdominal and skeletal adiposity and improves insulin sensitivity in OLETF rats

The effect of peroxisome proliferator-activated receptor (PPAR)-alpha activators on the liver is well established, but the other effects on muscle and adipose tissue about lipid metabolism and insulin sensitivity are not clear. We investigated whether PPAR-alpha activation affects adiposity of skeletal muscle as well as adipose tissue and improves insulin sensitivity in spontaneous type 2 diabetes model, Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Thirty-three weeks of aged, 20 male OLETF rats were divided into two groups. Control group (n=10) was fed with chow and treatment group (n=10) with chow contained fenofibrate for 7 weeks. At the age of 40 weeks, all rats were examined with MRI, intravenous glucose tolerance test, and then sacrificed for measurement of fat mass and RNA analyses. The total fat (the sum of subcutaneous, mesenteric, epididymal, and retroperitoneal fat pads) measured by dissection was significantly reduced in treatment group. The signal intensity of muscular adiposity was significantly decreased in treatment group. The mRNA levels of FAT/CD36 and mitochondrial carnitine palmitoyltransferase I (M-CPT I) in liver were remarkably increased. Fasting plasma insulin and leptin levels, insulin response after intravenous glucose loading and homeostasis model assessment insulin resistance (HOMA(IR)) index were lowered in treatment group. Fenofibrate increase mitochondrial fatty acid beta-oxidation in liver but not in skeletal muscle and lower the plasma levels of triglyceride and free fatty acid. It might result in reduction of adiposity of truncal adipose tissue and skeletal muscle. We suggest that reduction of adiposity in trunk and skeletal muscle might improve insulin sensitivity.

Multijet and multistage aerosol concentrator: design and performance analysis

A multijet and multistage aerosol concentrator was designed and fabricated with two virtual impactors in a series. Collection efficiency, internal loss, and concentration factors were calculated at ambient conditions for each stage. The total inlet flow rate of the aerosol concentrator was set at 1000 L/min(-1), while the minor flow rate for the first stage was at 6.0% of the total inlet flow and the minor flow rate of the second stage was at 6.7% of the first stage minor flow. The aerosol concentrator was calibrated using polystyrene latex particles in aerodynamic sizes ranging from 0.5 to 10 microm. Several configurations of the multijet acceleration nozzles and multitube receptors were designed in this study. The effects of the different designs were subsequently evaluated through experimentation. It was found that a properly designed multijet and multistage aerosol concentrator can significantly improve aerosol concentration performance. Results showed that the concentration factor increases from 1 to 240 over the particle size range studied. Applications of the multijet and multistage aerosol concentrator with high-volume flow rate can vary widely, from detection of biological aerosols at low concentration, laboratory aerosol sampling, clean room monitoring, and ambient aerosol measurements.

Differential diagnosis of Salmonella gallinarum and S. pullorum using PCR-RELP

Salmonellosis in poultry of Korea is a significant health problem, which causes substantial economic losses. The most common causative agents of chicken salmonellosis ar S. gallinarum and S. pullorum. Traditional methods used to detect Salmoenella spp. In chicken are tedious, time consuming and confer little guarantee of sensitivity and species specificity. Therefore, a rapid and sensitive method for the differentiation of Salmonella serogroup D was assessed. We first amplified the rfbS genes by PCR and characterized the amplified product by nucleotide sequence analysis. The homology of nucleotide sequence was 99.7% between S. gallinarum and S. pullorum rfbS genes. Further comparisons of the sequences of S. gallinarum, S. gallinarum fied strain, S. pullorum and S. typhi(GenBank Accession No.M29682) showed a homology of 98.3%. The predicted amino acid sequence homology was 97.1%, 97.1% and 97.5%, respectively. Based on this comparison of these nucleotide sequences, we found unique restriction enzyme sites within the rfbS genes of S. gallinarum and S. pullorum. Thus, the PCR products could be further digested with restriction enzymes TfiI and PleI for use in a restriction fragment length polymorphism (RELP) technique. This method can be applied in the differential diagnosis between S. gallinarum and S. pullorum.

Proton magnetic resonance chemical shift imaging (1H CSI)-directed stereotactic biopsy

INTRODUCTION

To add metabolic information during stereotactic biopsy target selection, the authors adopted proton chemical shift imaging (1H CSI)-directed stereotactic biopsy. Currently, proton single voxel spectroscopy (SVS) technique has been reported in stereotactic biopsy. We performed 1H CSI in combination with a stereotactic headframe and selected targets according to local metabolic information, and evaluated the pathological results.

PATIENTS AND METHOD

The 1H CSI-directed stereotactic biopsy was performed in four patients. 1H CSI and conventional Gd-enhancement stereotactic MRI were performed simultaneously after the fitting of a stereotactic frame. After reconstructing the metabolic maps of N-acetylaspartate (NAA)/phosphocreatine (Cr), phosphocholine (Cho)/Cr, and Lactate/Cr ratios, focal areas of increased Cho/Cr ratio and Lac/Cr ratios were selected as target sites in the stereotactic MR images.

RESULTS

1H CSI is possible with the stereotactic headframe in place. No difficulty was experienced performing 1H CSI or making a diagnosis. Pathological samples taken from areas of increased Cho/Cr ratios and decreased NAA/Cr ratios provided information upon increased cellularity, mitoses and cellular atypism, and facilitated diagnosis. Pathological samples taken from areas of increased Lac/Cr ratio showed predominant feature of necrosis.

CONCLUSION

1H CSI was feasible with the stereotactic headframe in place. The final pathological results obtained were concordant with the local metabolic information from 1H CSI. We believe that 1H CSI-directed stereotatic biopsy has the potential to significantly improve the accuracy of stereotactic biopsy targeting.

Metabolic changes in pericontusional oedematous areas in mild head injury evaluated by 1H MRS

In order to define metabolic brain changes associated with mild traumatic brain injury, proton magnetic resonance spectroscopy (MRS) was performed in patients with regional brain contusion and 13-15 of initial GCS score. The authors measured N-acetylaspartate(NAA)/creatine(Cr) ratio and lactate signal on in vivo proton MRS, which indicated cell loss and ischaemic dAmage respectively, in pericontusional oedematous areas (region of interest; ROI) adjacent to traumatic brain contusion on brain MRI to determine possible metabolic changes. The metabolic ratio of NAA/Cr and lactate/Cr peaks was measured both in the ROI and a corresponding region of the contralateral hemisphere (ROC) in seven patients and twenty-five normal control. In initial NAA/Cr ratios, the values of ROIs were significantly lower than those of the control (p = 0.009), but there was no difference either between ROI and ROC (p = 0.410) or between ROC of patients and the control (p = 0.199). In lactate/Cr ratios, the ROI in all seven patients and the ROC in two showed increased lactate signals. The lacate/Cr ratios of the ROIs were significantly elevated as compared to those of the ROCs (p = 0.02) and the control (p = 0.015). In 2-month follow up, lactate signals were absent or significantly reduced (p = 0.015). In no patients, clinical or radiological deterioration has been observed. Our results demonstrate that there is significant neuronal dysfunction in pericontusional oedematous areas as indicated by NAA/Cr ratios in the patients with mild head injury at both early and late stages. And there are significant ischaemic changes as indicated by increase of lactate level in ROI at early stage. These findings suggest that pericontusional oedematous areas can be vulnerable to secondary brain insults even in the patients with mild head injury.

Hemodynamic effects on atherosclerosis-prone coronary artery: wall shear stress/rate distribution and impedance phase angle in coronary and aortic circulation

The objective of the present study was to evaluate the hemodynamic characteristics of an atherosclerosis-prone coronary artery compared to the aorta. We describe three- dimensional spatial patterns of wall shear stress (WSS) according to the impedance phase angle in pulsatile coronary and aorta models using in vivo hemodynamic parameters and computed numerical simulations both qualitatively and quantitatively. Angiography of coronary arteries and aortas were done to obtain a standard model of vascular geometry. Simultaneously to the physiologic studies, flow-velocity and pressure profiles from in vivo data of the intravascular Doppler and pressure wire studies allowed us to include in vitro numerical simulations. Hemodynamic variables, such as flow-velocity, pressure and WSS in the coronary and aorta models were calculated taking into account the effects of vessel compliance and phase angle between pressure and flow waveforms. We found that there were spatial fluctuations of WSS and in the recirculation areas at the curved outer wall surface of the coronary artery. The mean WSS of the calculated negative phase angle increased in the coronary artery model over that in the aorta model and the phase angle effect was most prominent on the calculated amplitude of WSS of the coronary artery. This study suggests that the rheologic property of coronary circulation, such as the fluctuation of WSS/WSR induces several hemodynamic characteristics. A separation of flow-velocity, a difference in phase between pressure conductance and blood flow and prominent temporal and/or spatial oscillatory fluctuations of the shear forces as a function of pulsatile flow might be important factors in atherogenesis and progression of atherosclerosis.

Treatment of recalcitrant recurrent corneal erosions with inhibitors of matrix metalloproteinase-9, doxycycline and corticosteroids

PURPOSE

To review the efficacy of inhibitors of matrix metalloproteinase-9, corticosteroids, and doxycycline for treatment of recalcitrant recurrent corneal erosion.

METHODS

Retrospective, clinic-based, interventional case series. The medical records of seven consecutive patients who were treated between January 1995 to January 2000 for recurrent corneal erosion who had not responded to conventional therapy were reviewed. Treatment of seven eyes of seven patients consisted of oral doxycycline (50 mg, two times a day) for 2 months along with a topical corticosteroid (either methylprednisolone 1%, prednisolone acetate 1%, or fluoromethalone 0.1%) three times a day, for 2 to 3 weeks. The effects of doxycycline and methylprednisolone on metalloproteinase-9 activity in human corneal epithelial cultures were evaluated by gelatin zymography and a commercial metalloproteinase-9 activity assay kit.

RESULT

Fingernail injury in three of the seven eyes was the most common form of corneal injury. There was no evidence of epithelial basement membrane or corneal stromal dystrophy in any of the patients, although epithelial microcysts were observed in the involved area in three patients. One eye had intact elevated corneal epithelium that showed abnormal diffuse staining with fluorescein dye, and six eyes had a corneal epithelial defect at the time of presentation. In all seven eyes, pain resolved and epithelial defects healed within 2 to 10 days after initiation of therapy. No recurrence was observed during an average follow-up period of 21.9 months (range, 1.5 to 60 months). Methylprednisolone and doxycycline each produced a statistically significant decrease in amount and activity of metalloproteinase-9 in conditioned media of human corneal epithelial cultures.

CONCLUSIONS

Therapy with a combination of medications that inhibit metalloproteinase-9 produced rapid resolution and prevented further recurrence of cases of recurrent corneal erosions that were unresponsive to conventional therapies.

A co-operative study: clinical characteristics of 334 Korean patients with moyamoya disease treated at neurosurgical institutes (1976-1994). The Korean Society for Cerebrovascular Disease

A co-operative study was conducted to determine the clinical characteristics of patients with moyamoya disease who were diagnosed and treated at neurosurgical institutes in Korea before 1995. Twenty-six hospitals contributed 505 cases and among them, the clinical characteristics of 334 patients with definite moyamoya disease were evaluated. The number of patients began to increase from the late 1980s, and after that approximately 20 patients were treated each year. There were two age peaks: from six to 15 and from 31 to 40 years of age. Haemorrhagic manifestations occurred in approximately 43% of the patients. The major clinical manifestations were haemorrhage in adults (62.4%) and ischaemia in children (61.2%). Overall 54.5% of the patients experienced decreased consciousness levels, mainly due to intracranial haemorrhage or cerebral infarction. In the patients with ischemic manifestations, the adult patients were more likely to have cerebral infarction than the pediatric patients (80% vs. 39%) and the pediatric patients were more likely to have TIA (61% vs. 25%). Thirty eight percent of the patients underwent bypass surgery and 53% of these procedures were performed bilaterally. Treatment policies, including indications for bypass surgery and commonly used drugs, were somewhat different according to the institution. Overall favorable outcome was 73%, and the most significant factor affecting poor outcome was haemorrhagic manifestation. This article describes the characteristics of 334 patients with moyamoya disease, who were diagnosed and treated at neurosurgical institutes in Korea before 1995.

Aerosol keratopathy: a revised MacLean classification

Case report. Chemical keratopathy has been linked to many household aerosols. We present a dramatic case of aerosol keratopathy. The finding of an unexplained epithelial or superficial stromal keratopathy must alert the physician to inquire about the use of household aerosols near the patient's face. We also propose a revised classification system based on the work of MacLean.

Expression of MAGE-1, -2, and -3 genes in gastric carcinomas and cancer cell lines derived from Korean patients

We investigated the expression of MAGE-1, -2, and -3 genes in tissues of 51 gastric carcinomas from Korean patients and in 11 gastric cancer cell lines established in Korea using reverse transcriptase-polymerase chain reaction along with immunohistochemical analyses and DNA sequencing. Among the 51 gastric carcinomas, MAGE-1, -2, and -3 genes were expressed in 16 (31%), 22 (43%), and 17 (33%), respectively, and 31 (60%) expressed at least one of the three genes. In contrast, none of the three MAGE genes were expressed in normal sites of gastric tissue from each cancer patient. Out of 11 gastric cancer cell lines, MAGE-1, -2, and -3 genes were expressed in two (18%), five (46%), and four (36%), respectively. According to the clinicopathological analysis, the expression of any of the three MAGE genes was not significantly correlated with several clinicopathological factors except histologic types (p= 0.067). Immunohistochemical analyses identified positive staining with monoclonal antibodies 77B and 57B specifically against MAGE-1 and -3 proteins, respectively, in nuclei and cytoplasms of cells in mRNA-positive tumor tissue. These findings suggest the possibility as a target for tumor-specific immunotherapy for Korean patients.

Microsatellite instability, prognosis and metastasis in gastric cancers from a low-risk population

We examined 169 cases of gastric adenocarcinoma for microsatellite instability (MSI), using a panel of 8 microsatellite markers. Of these cases, 142 were from the United States, a country of relatively low risk for gastric cancer. Comparing microdissected tumors to normal cells from the same patient, we classified tumors as being microsatellite-stable (MSS) or having a low frequency of MSI (MSI-L, up to 30% of markers different in the tumor) or a high frequency of MSI (MSI-H, 30% or more of markers different). Among our American cases, we identified 26 (18.2%) showing MSI-H and 15 (10.6%) showing MSI-L. Twenty cases were from Korean patients, and they showed no significant differences in proportions of MSI-H and MSI-L from the American cases. MSI-H tumors in the American patients were characterized by elevated frequencies of band shifts in repeat sequences of the BAX (50%), transforming growth factor-beta receptor type II (TGFbetaRII, 68.9%), beta(2)-microglobulin (21.4%) and E2F4 (51.7%) genes. Alterations in E2F4 in MSI-H tumors were always integral multiples of 3 nucleotides lost or gained, which would not cause a frameshift mutation, and within the range of normal polymorphisms for this sequence. North American patients (n = 127) with MSI-H and MSI-L tumors had a longer median survival of 541 days and 587 days, respectively, compared to 265 days for patients with MSS tumors (p = 0.027). This survival difference may result from a significantly greater tendency for metastases in the MSS group (p = 0.031).

Microsatellite instability, prognosis and metastasis in gastric cancers from a low-risk population

We examined 169 cases of gastric adenocarcinoma for microsatellite instability (MSI), using a panel of 8 microsatellite markers. Of these cases, 142 were from the United States, a country of relatively low risk for gastric cancer. Comparing microdissected tumors to normal cells from the same patient, we classified tumors as being microsatellite-stable (MSS) or having a low frequency of MSI (MSI-L, up to 30% of markers different in the tumor) or a high frequency of MSI (MSI-H, 30% or more of markers different). Among our American cases, we identified 26 (18.2%) showing MSI-H and 15 (10.6%) showing MSI-L. Twenty cases were from Korean patients, and they showed no significant differences in proportions of MSI-H and MSI-L from the American cases. MSI-H tumors in the American patients were characterized by elevated frequencies of band shifts in repeat sequences of the BAX (50%), transforming growth factor-beta receptor type II (TGFbetaRII, 68.9%), beta(2)-microglobulin (21.4%) and E2F4 (51.7%) genes. Alterations in E2F4 in MSI-H tumors were always integral multiples of 3 nucleotides lost or gained, which would not cause a frameshift mutation, and within the range of normal polymorphisms for this sequence. North American patients (n = 127) with MSI-H and MSI-L tumors had a longer median survival of 541 days and 587 days, respectively, compared to 265 days for patients with MSS tumors (p = 0.027). This survival difference may result from a significantly greater tendency for metastases in the MSS group (p = 0.031).

The Molecular Spreading of Nonpolar Perfluoropolyether Films on Amorphous Carbon Surfaces

The spreading mechanism of nonpolar perfluoropolyether films on carbon surfaces is examined in the mesoscopic regime, including both submonolayer and multilayer films. For the submonolayer film, adsorption-desorption is a main mechanism for spreading, and the surface diffusion coefficients increase as the film thickness increases. The driving force for the spreading in the submonolayer regime is the gradient of the disjoining pressure, which is described by the two-dimensional virial equation. For the multilayer film regime, the spreading characteristics are determined by the molecular weight and the disjoining pressure gradient, which is assumed to be purely van der Waals in nature. We adopt a partial slip boundary condition to analyze the multilayer film, which qualitatively explains the dependence of the surface diffusion coefficient on film thickness. Copyright 2000 Academic Press.

Identification of a calmodulin-regulated soybean Ca(2+)-ATPase (SCA1) that is located in the plasma membrane

Ca(2)+-ATPases are key regulators of Ca(2+) ion efflux in all eukaryotes. Animal cells have two distinct families of Ca(2+) pumps, with calmodulin-stimulated pumps (type IIB pumps) found exclusively at the plasma membrane. In plants, no equivalent type IIB pump located at the plasma membrane has been identified at the molecular level, although related isoforms have been identified in non-plasma membrane locations. Here, we identify a plant cDNA, designated SCA1 (for soybean Ca(2+)-ATPase 1), that encodes Ca(2+)-ATPase and is located at the plasma membrane. The plasma membrane localization was determined by sucrose gradient and aqueous two-phase membrane fractionations and was confirmed by the localization of SCA1p tagged with a green fluorescent protein. The Ca(2+)-ATPase activity of the SCA1p was increased approximately sixfold by calmodulin (K(1/2) approximately 10 nM). Two calmodulin binding sequences were identified in the N-terminal domain. An N-terminal truncation mutant that deletes sequence through the two calmodulin binding sites was able to complement a yeast mutant (K616) that was deficient in two endogenous Ca(2+) pumps. Our results indicate that SCA1p is structurally distinct from the plasma membrane-localized Ca(2+) pump in animal cells, belonging instead to a novel family of plant type IIB pumps found in multiple subcellular locations. In plant cells from soybean, expression of this plasma membrane pump was highly and rapidly induced by salt (NaCl) stress and a fungal elicitor but not by osmotic stress.

Potentials and limitations of adenovirus-p53 gene therapy for brain tumors

We investigated the antineoplastic potentials of recombinant adenovirus containing wild-type p53 cDNA (Ad5CMV-p53) for malignant gliomas. In four human glioma cell lines (U-251 and LG expressing endogenous mutant p53, and U-87 and EFC-2 expressing wild-type p53) and two rat glioma cell lines (9L and C6, each expressing mutant and wild-type p53), gene transfer efficiency determined by X-gal staining and Western blotting was varied (10-99% at 10-500 multiplicity of infection, MOI). Growth inhibitory effect was drastic (>90% at 100 MOI) in U-251 cells and only moderate or minimal in other cell lines harboring wild-type p53 or low gene transfer efficiency. Ex vivo transduction of U-251 cells with Ad5CMV-p53 suppressed the in vivo tumorigenicity of the cells. Histopathologic examination for Ad5CMV-p53 toxicity to rat brains showed inflammatory reactions in half of the tested brains at 10(8) MOI. U-251 cells were inoculated intracerebrally in nude mice and injected Ad5CMV-p53 into the tumor, in which neither the tumor suppression nor the survival benefit was observed. In conclusion, heterogeneity of the cellular subpopulations of malignant glioma in p53 status, variable and insufficient gene delivery to tumor, and adenoviral toxicity to brain at higher doses may be limiting factors to be solved in developing adenovirus-p53 gene therapy for malignant gliomas.

Infestation status of head louse and treatment with lindane shampoo in children of primary school and kindergarten in Chinju-shi, Kyongsangnam-do, Korea

The infestation status of head louse among children attending primary schools and kindergartens in Chinju-shi, Kyongsangnam-do, Korea, was investigated between June and July 1999. Out of 2,288 children examined, 3.9% of boys (48/1,242) and 23.5% of girls (246/1,046) were infested with nits or adult/nymphs of lice. The effectiveness of lindane shampoo (1% gamma benzene hexachloride solution) was evaluated after one or two time applications to all the children infested. The negative conversion rate of pediculosis was 93.5%. Effective control measures are needed to control and prevent such ectoparasite infestation amongst children.

Competitive binding of calmodulin isoforms to calmodulin-binding proteins: implication for the function of calmodulin isoforms in plants

In plants, multiple calmodulin (CaM) isoforms exist in an organism which vary in their primary structures in as much as 32 residues out of their 148 amino acids. These CaM isoforms show differences in their expression patterns and/or target enzyme activation ability. To further understand the biological significance of CaM isoforms, we examined whether CaM isoforms act on specific regulatory targets. In gel overlay assays on various soybean tissue extracts, surprisingly, two soybean CaM isoforms (SCaM-1 and SCaM-4) did not show significant differences in their target binding protein profiles, although they exhibited minor differences in their relative target binding affinities. In addition, both SCaM isoforms not only effectively bound five known plant CaMBPs, but also showed competitive binding to these proteins. Finally, immunolocalization experiments with the SCaM proteins in sections of various tissues using specific antibodies revealed similar distribution patterns for the SCaM isoforms except for root tissues, which indicates that the SCaM isoforms are concomitantly expressed in most plant tissues. These results suggest that CaM isoforms may compete for binding to CaMBPs in vivo. This competitive nature of CaM isoforms may allow modulation of Ca(2+)/CaM signaling pathways by virtue of relative abundance and differential target activation potency.

Involvement of specific calmodulin isoforms in salicylic acid-independent activation of plant disease resistance responses

The Ca2+ signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. Here we demonstrate that specific calmodulin (CaM) isoforms are activated by infection or pathogen-derived elicitors and participate in Ca2+-mediated induction of plant disease resistance responses. Soybean CaM (SCaM)-4 and SCaM-5 genes, which encode for divergent CaM isoforms, were induced within 30 min by a fungal elicitor or pathogen, whereas other SCaM genes encoding highly conserved CaM isoforms did not show such response. This pathogen-triggered induction of these genes specifically depended on the increase of intracellular Ca2+ level. Constitutive expression of SCaM-4 and SCaM-5 in transgenic tobacco plants triggered spontaneous induction of lesions and induces an array of systemic acquired resistance (SAR)-associated genes. Surprisingly, these transgenic plants have normal levels of endogenous salicylic acid (SA). Furthermore, coexpression of nahG gene did not block the induction of SAR-associated genes in these transgenic plants, indicating that SA is not involved in the SAR gene induction mediated by SCaM-4 or SCaM-5. The transgenic plants exhibit enhanced resistance to a wide spectrum of virulent and avirulent pathogens, including bacteria, fungi, and virus. These results suggest that specific CaM isoforms are components of a SA-independent signal transduction chain leading to disease resistance.

Effects of systemic hypothermia and selective brain cooling on ischemic brain damage and swelling

The present study investigates the neuroprotective effects of temporary mild systemic hypothermia and selective brain cooling against focal cerebral infarction in the rat and the changes of cortical blood flow, and compares these two treatment modalities. In permanent middle cerebral artery (MCA) model, the treatments were induced 15 min following the artery occlusion. The animals were kept at the desired rectal or brain temperature (about 32 degrees C) for 30 min; (each, n = 6) and for 1 hr (each, n = 6), and then allowed to rewarm spontaneously, whereas control animals were kept at normothermia throughout the experiment. The volumes of brain infarction and edema were assessed 24 hr post-occlusion. The blood flow of the dorsolateral cortex was monitored by Laser-Doppler flowmetry (LDF) in the other experiments. Hemispheric infarct volume was attenuated only in the animals treated for 1 hr with systemic hypothermia (49.2%, P < 0.001) and selective brain cooling (26.7%, P < 0.01). The volume of brain swelling was diminished only in the animals treated with systemic hypothermia for 1 hr (23.6%, P < 0.05). LDF examination revealed a sharp drop in blood flow upon MCA occlusion and maintaining in low blood flow throughout the experiment in the control and systemic hypothermia. However, in the selective brain cooling, the reduced blood flow increased from 40% to 70% of baseline value while the brain was rewarmed. The present study indicates that mild systemic hypothermia has much stronger protective effects against focal cerebral infarction and edema than selective brain cooling. The lack of protective effects of selective brain cooling may be caused by post-cooling cerebral hyperemia in the ischemia area.

Up-regulation of the expression of major histocompatibility complex class I antigens by plasmid DNA transfection in non-hematopoietic cells

The effect of DNA on the surface expression of major histocompatibility (MHC) class I antigens was examined in non-hematopoietic tumor cell lines. Transfection with plasmid DNA via liposome or electroporation significantly increased the surface expression of MHC class I molecules in a transient manner. Northern blot analysis showed that levels of MHC class I mRNA were increased by DNA transfection, probably via transcriptional activation. In contrast, the expression of the MHC class II and beta-actin genes was not affected, suggesting that the up-regulation of MHC class I expression by plasmid DNA works in a gene-specific manner.

Neuronal laterality in Parkinson's disease with unilateral symptom by in vivo 1H magnetic resonance spectroscopy

RATIONALE AND OBJECTIVES

The authors investigate whether there is a lateral effect of 1H-magnetic resonance spectroscopy (MRS) observable metabolite ratios between the symptomatic and the asymptomatic side in Parkinson's disease with unilateral symptoms.

METHODS

Localized in vivo 1H MRS was used to measure the metabolite levels in the symptomatic and the asymptomatic sides of the substantia nigra (SN) and putamen-globus pallidus (PG) in Parkinson's disease with unilateral symptom (n = 15). The metabolite ratios of N-acetylasparatate (NAA)/creatine (Cr), and choline-containing compounds (Cho)/Cr in the symptomatic side were compared with those in the asymptomatic side. According to the symptomatic duration, the authors evaluated whether there was a specific correlation between laterality and the clinical stage.

RESULTS

Significant metabolic lateral effect of NAA/Cr ratio was established between the symptomatic and the asymptomatic sides of SN and PG in Parkinson's disease with unilateral symptoms (P = 0.03). The decreased NAA/Cr ratio was calculated in at least one of the selected regions in SN and PG, indicating neuronal loss. The main observations were that NAA/Cr ratios were reduced in the left symptomatic side (n = 7; P = 0.001) and reduced to a lesser degree in the right symptomatic side (n = 8; P = 0.03 [PG], P = 0.21 [SN]) and that there was no significant laterality of other metabolite ratios.

CONCLUSIONS

On the basis of NAA/Cr ratios between the symptomatic and the asymptomatic sides, the present 1H MRS study shows a significant neuronal laterality in Parkinson's disease with unilateral symptoms. In vivo 1H MRS may provide a diagnostic marker for neuronal dysfunction in Parkinson's disease with unilateral symptoms.

Clinical results of 24 pituitary macroadenomas with linac-based stereotactic radiosurgery

PURPOSE

To determine the impact of stereotactic radiosurgery (SRS) on the clinical course, hormonal status, and follow-up CT/MRI scan of pituitary macroadenomas.

METHODS AND MATERIALS

From July 1988 to March 1996, 24 pituitary macroadenomas had been treated using 6 MV linear accelerator based SRS. They consisted of 11 (45.8%) prolactinomas, 2 (8.3%) growth hormone (GH)-secreting tumors, 1 (4.2%) Cushing's disease, 8 (33.3%) nonsecreting (nonfunctioning: NF) tumors, and 2 (8.3%) mixed prolactin-growth hormone (PRL-GH)-secreting tumors (M:F = 12:12; aged 21-61 years). Postoperative irradiation was performed in all cases except for the instance of Cushing's disease. The prescribed dose to tumor center varied from 10 to 27 Gy (mean 21.1 Gy) using a collimator size of 0.5 to 2.5 cm. The follow-up duration ranged from 13 to 89 months (mean 49.2 months). Results from these patients were compared to our results using conventional radiation.

RESULTS

Visual acuity and field defect were improved or became normal in 19 (79.2%) cases. Four (16.7%) remained unchanged after the treatment. One (4.1%) progressed 6 years after SRS and subsequently had repeat surgery with conventional boost irradiation. Of the 13 (46.4%) prolactinomas, including two mixed PRL-GH secreting tumors, 11 (84.1%) revealed normal hormonal levels within 1 year after SRS. In contrast, it took 2 years to become normal after conventional radiation therapy. In four GH-secreting tumors including two mixed PRL-GH secreting tumors, SRS and conventional methods showed similar responses. On follow-up imagings of the 21 patients, the mass was completely resolved in 4 (16.7%), including 3 PRLs and one NF, decreased in 11 (45.8%), and unchanged in 5 (16.7%) with central necrosis or cysts. One (4.2%) progressed and was reoperated 6 years after treatment. The complications related to SRS were comparable to those from conventional method.

CONCLUSION

Radiosurgery can be used effectively in patients with pituitary adenoma. In this study, a more rapid hormonal and clinical response was achieved with radiosurgery than with conventional pituitary irradiation treatment.

Experience with pineal region tumors

The results are reported of a retrospective review of the presentation and outcome of 43 pineal region tumors treated from 1982 to 1996, including 20 identified tumors: 5 germinomas, 8 teratomas, 2 embryonal carcinomas, 1 endodermal sinus tumor, 2 pineocytomas and 2 pineoblastomas. Of the 43 tumors reviewed, 36 were located in the pineal region, 5 in the suprasellar, and 2 in both the pineal and suprasellar regions. Twenty patients underwent surgical resection: total in 6 and partial in 10, while only a biopsy was taken in 4 cases. Fifteen patients were managed on the basis of serum CSF tumor markers and radiation response. Twenty-three patients with germinomas received radiotherapy (RT) and had a 5-year survival rate of 87%. Fifteen patients with non-germinomatous germ cell tumors received RT and chemotherapy following direct surgery, and 5 died (mortality rate of 33.3%). The overall survival rate of the 43 patients with pineal tumors was 79.1% (34/43) and the death rate was 20.9% (9/43). It is now recognized that the wide variety of tumor types found in the pineal region necessitates different modes of treatment, and improved microsurgical and stereotactic surgical techniques have made mortality and morbidity rates acceptably low. Because the radiation response and CSF cytology are not enough to determine optimum treatment, a tissue diagnosis should be obtained in all patients.