Photoluminescent properties of (la(1-x)Y(x))(0.94)Tb(0.06)PO4 phosphor powders prepared by ultrasonic spray pyrolysis

The calculated crystallite sizes of (La(1-x)Y(x))(0.94)Tb(0.06)PO4 (0 < or = x < or = 1.0) phosphors ranged from 37-39 nm. Annealed (La(1-x)Y(x))(0.94)Tb(0.06)PO4 (0 < or = x < or = 1.0) phosphors showed a smooth, regular, and spherical morphology. Strong excitation peaks were appeared at 226 and 270 nm for all the phosphors. These were caused by the crystal splitting of 7D and 9D of 4f75d1 configuration in Tb3+, respectively. The characteristic emission peaks were observed at 489, 543, 585, and 621 nm, which were caused by the 5D4-7F(j) (j = 6-3) transitions of Tb3+, respectively. The emission intensity at 543 nm increased with an increase in Y content up to 0.5 and then decreased for a higher Y content.

A clinical audit of neurosurgical bed usage

AIM

To investigate inefficiencies during patients' stay in neurosurgical beds.

METHODS

A prospective audit of neurosurgical inpatients was conducted over approximately 2 months. We recorded the causes and duration of inappropriate delays, defined as actions requiring more that 24 h from initiation until completion.

RESULTS

One-hundred-and-thirty-eight patients were studied (61 elective and 77 emergency admissions). The audited patients were in hospital for a total of 1665 days. Of these, 482 days (29%) were due to delays. 92.5% of these wasted days involved emergency admissions. The main categories of delay were transfer back to referring hospital (46% of all delays), operative (26%) and radiological (19%). Our own hospital was responsible for the longest transfer delays (6.3 days/patient compared with an average of 2.8 for all hospitals). Operative waits arose because of problems with both the timing and capacity of lists. Radiological delays resulted in particular from waits for MRI scans and neuroradiologist-performed procedures. The effect of eliminating all these inappropriate delays would be equivalent to liberating 10.7 of our 37 neurosurgical beds at any one time.

CONCLUSIONS

Clinician-led analysis of organizational aspects of patient care has revealed serious structure, process and capacity problems in efficient bed usage, We have made proposals to address the cause of the inappropriate delays.

Controlled microaspiration for high-pressure freezing: a new method for ultrastructural preservation of fragile and sparse tissues for TEM and electron tomography

High-pressure freezing is the preferred method to prepare thick biological specimens for ultrastructural studies. However, the advantages obtained by this method often prove unattainable for samples that are difficult to handle during the freezing and substitution protocols. Delicate and sparse samples are difficult to manipulate and maintain intact throughout the sequence of freezing, infiltration, embedding and final orientation for sectioning and subsequent transmission electron microscopy. An established approach to surmount these difficulties is the use of cellulose microdialysis tubing to transport the sample. With an inner diameter of 200 microm, the tubing protects small and fragile samples within the thickness constraints of high-pressure freezing, and the tube ends can be sealed to avoid loss of sample. Importantly, the transparency of the tubing allows optical study of the specimen at different steps in the process. Here, we describe the use of a micromanipulator and microinjection apparatus to handle and position delicate specimens within the tubing. We report two biologically significant examples that benefit from this approach, 3D cultures of mammary epithelial cells and cochlear outer hair cells. We illustrate the potential for correlative light and electron microscopy as well as electron tomography.

A model of the effect of temperature on the growth of pathogenic and nonpathogenic Vibrio parahaemolyticus isolated from oysters in Korea

Vibrio parahaemolyticus is recognized as the leading cause of human gastroenteritis associated with the consumption of seafood. The objective of this study was to model the growth kinetics of pathogenic and nonpathogenic V. parahaemolyticus in broth and oyster slurry. Primary growth models of V. parahaemolyticus in broth and oyster slurry fit well to a modified Gomperz equation (broth R(2)=0.99; oyster slurry R(2)=0.96). The lag time (LT), specific growth rate (SGR), and maximum population density (MPD) of each primary model were compared. The growth of nonpathogenic V. parahaemolyticus was found to be more rapid than that of pathogenic V. parahaemolyticus, regardless of the model medium. In addition, significant (P<0.05) differences in the growth kinetics between pathogenic and nonpathogenic V. parahaemolyticus in broth were observed at 10 degrees C. When compared to growth in broth, the growth of V. parahaemolyticus was delayed in oyster slurry, and growth was not observed at 10 or 15 degrees C. The Davey and square root models were identified as appropriate secondary models for predicting the LT and SGR, respectively. For the broth model, the average B(f) and A(f) values for LT were found to be 0.97 and 1.3, respectively, whereas the average B(f) and A(f) values for SGR were 1.05 and 1.11, respectively. The model generated in this study predicted an LT that was shorter and an SGR that was similar to those that were actually observed, which indicates that these models provide a reliable and safe prediction of V. parahaemolyticus growth.

First Report of Chestnut Ink Disease by Phytophthora katsurae on Chestnut in Korea

Since the late 1970s, chestnut (Castanea spp.) has been one of the most commonly cultivated nuts for human consumption in Korea. In 1998, as much as 100,000 t of chestnut seeds were produced from 79,000 ha of plantations for export (2). Most cultivated chestnuts are hybrids of Castanea crenata and C. mollissima that have resulted in 27 cultivars commonly grown in Korea. In 2004, dead trees of two cultivars (Tsukuba and Ginyose) from different locations were found with black ooze emanating from reddish, sunken tissues on the trunks. When the bark was peeled off, a distinct necrotic region was observed on the basal trunk with the discoloration extending up and girdling the trunk. In November 2006, a Phytophthora species was isolated from the necrotic areas with a CARP selective medium (4). Eleven isolates were obtained from three locations: Hadong, Hapcheon, and Youngqwang. The isolates produced numerous homothallic oogonia (34.0 to 46.2 × 21.9 to 26.7 μm) with warty protuberances on the surface. Antheridia were amphigynous with long, funnel-shaped stalks at the base of the oogonia. The formation of papillate, ovoid to obpyriform sporangia (17.0 to 38.9 × 14.6 to 29.2 μm) was induced by cold treatment in filtered (through 25-μm particle retention) creek water or deionized water. Chlamydospores were not observed. Comparison of the rDNA ITS sequence using ITS1/4 (3) showed 99.6% similarity to P. katsurae (GenBank Accession No. AF266771) with three base pair differences. All eleven isolates showed identical ITS sequences. Pathogenicity studies were conducted on excised three 15-cm-long × 5-cm-diameter logs from each of three chestnut cultivars (Moriwase, Parkmi 2, and Ibuki). Bark (5 mm in diameter) was taken with a cork borer on each log followed by inoculation with a 5-mm agar disk of two isolates, PH.K01 and PH.K07. The logs were placed in a moist chamber for 7 days. Noninoculated controls consisted of log sections from each cultivar treated with agar disks. The pathogencity test was repeated three times. The entire log of cv. Parkmi 2 became necrotic, whereas the other two cultivars developed only small lesions (P < 0.0001). The noninoculated control logs of each cultivar did not develop lesions and no pathogen was reisolated from them. This suggests that cultivars differ in susceptibility. P. katsurae (synonym = P. castaneae) was first described from Japan in 1931. P. cambivora, P. cinnamomi, and P. katsurae are commonly responsible for ink disease on chestnut species in Europe, the United States, and Asia (1). The impact of P. katsurae on chestnut production in Korea is currently unknown. References: (1) A. Boutard et al. The West. Chestnut. 3:6, 2001. (2) S. H. Lee et al. J. Korean For. Soc. 95:61, 2006. (3) E. Oh et al. Forest Pathol. 36:388, 2006. (4) T. J. White et al. Page 315 in: PCR Protocols. Academic Press Inc., New York, 1990.

Effect of glass phase on the dissolution of hydroxyapatite

Nano size defect formation at grain boundary during the dissolution of hydroxyapatite in water was evaluated by adding several sintering additives for sinterability enhancement. In the case of sintered pure hydroxyapatite, significant dissolution occurred after immersion in distilled water or in simulated body fluid. The dissolution initiated at the grain boundaries creating nano-size defects like small pores that afterwards grew up to micro scale by increasing immersion time. This dissolution resulted in grain separation at the surfaces and finally in fracture. The dissolution concentrated on the grains adjacent to pores rather than those in the dense region. So hydroxyapatite ceramics containing glass powders were prepared to prevent the dissolution by strengthening grain boundary. Calcium silicate and phosphate glasses were added at 0 to 10 mass% and sintered at 1200 degrees C for 2 h in air with moisture protection. Glass phase was incorporated into hydroxyapatite to act as the sintering aid followed by crystallization in order to improve the mechanical properties without reducing biocompatibility. Dissolution tests, as well as X-ray diffraction and SEM showed little decomposition of hydroxyapatite to secondary phases and the fracture toughness increased compared to pure hydroxyapatite.

Retrospective multicenter study of a clinicopathologic analysis of pseudomyxoma peritonei associated with ovarian tumors (KGOG 3005)

The purpose of this study is to assess clinicopathologic features of pseudomyxoma peritonei (PMP) that has ovarian pathology and its relationship with the prognosis. From 1995 to 2004, the clinical records and follow-up data of 35 patients with PMP, which had primarily originated from the ovary, were collected from 11 institutes of gynecologic oncology in Korea and retrospectively analyzed. All patients had ovarian lesion histologically confirmed with PMP. The mean age at diagnosis was 53.7 years (range: 16-82 years). There were 25 (71.4%) patients with disseminated peritoneal adenomucinosis, 5 (14.3%) with peritoneal mucinous carcinomatosis with intermediate group, and 5 (14.3%) with peritoneal mucinous carcinomatosis. The clinical stages at diagnosis were IA in 2 patients, IIIB in 4, IIIC in 23, IV in 1, and unknown in 5. In preoperative tumor markers, the positive rates were 72% (CA125), 47.4% (CA19-9), and 84.6% (CEA). Thirty-four patients underwent surgical staging or cytoreduction, and then 27 patients (77%) received adjuvant chemotherapy that was given to patients in a nonuniform fashion. The 5-year survival for 35 patients was 87%. Survival rate was significantly lower in patients >50 years of age (P = 0.002). Our data showed that age of the patient is the only significant prognostic factor in PMP that has ovarian lesion.

Dosimetry calculations for internal electron sources using a Korean reference adult stylised phantom

Absorbed fractions (AFs) and specific absorbed fractions (SAFs) for internally deposited electron were calculated using a Korean reference adult stylised phantom, where a total of 15 internal organ volumes and external body dimension were designed to match average Korean adult male. The walls of oesophagus, stomach, colon and urinary bladder were additionally divided into the mucosal layer and residual wall to accommodate dose calculation for weakly penetrating electron. The mucosal wall thicknesses were determined by the data reported in the International Commission on Radiological Protection Publication 89 and other literature resources and by direct measurements. The Monte Carlo transport code MCNPX (version 2.5.0) was employed to calculate the electron energy deposited. The SAFs and AFs for monoenergetic electrons with the energies ranging from 10 keV to 2 MeV were calculated. The results were compared with those of the revised Oak Ridge National Laboratory phantoms and showed considerable differences up to 150% in SAFs, whereas no substantial differences were observed in the AFs.

Dose conversion coefficients calculated using tomographic phantom, KTMAN-2, for X-ray examination of cardiac catheterisation

In this study, organ-absorbed doses and effective doses to patient during interventional radiological procedures were estimated using tomographic phantom, Korean Typical Man-2 (KTMAN-2). Four projections of cardiac catheterisation were simulated for dose calculation by Monte Carlo technique. The parameters of X-ray source and exposure conditions were obtained from literature data. Particle transport was simulated using general purposed Monte Carlo code, MCNPX 2.5.0. Organ-absorbed doses and effective doses were normalised to dose area product (DAP). The effective doses per DAP were between 0.1 and 0.5 mSv Gy(-1) per cm2. The results were compared with those derived from adult stylised phantom. KTMAN-2 received up to 105% higher effective doses than stylised phantom. The dose differences were mainly caused by more realistic internal topology of KTMAN-2 compared to stylised phantom that are closely positioned organs near the heart and shift of abdominal organs to the thoracic region due to supine position. The results of this study showed that tomographic phantoms are more suitable for dose assessment of supine patients undergoing the interventional radiology. The results derived from KTMAN-2 were the first radiation dose data based on non-Caucasian individuals for interventional procedures.

Advanced H2O2 oxidation for diethyl phthalate degradation in treated effluents: effect of nitrate on oxidation and a pilot-scale AOP operation

One of the objectives of this study was to delineate the effect of nitrate on diethyl phthalate (DEP) oxidation by conducting a bench-scale ultraviolet (UV)/H2O2 and O3/H2O2 operations as suggested in a previous study. We also aim to investigate DEP oxidation at various UV doses and H2O2 concentrations by performing a pilot-scale advanced oxidation processes (AOP) system, into which a portion of the effluent from a pilot-scale membrane bioreactor (MBR) plant was pumped. In the bench-scale AOP operation, the O3 oxidation alone as well as the UV irradiation without H2O2 addition could be among the desirable alternatives for the efficient removal of DEP dissolved in aqueous solutions at a low DEP concentration range of 85+/-15 microg/L. The adverse effect in the UV/H2O2 process was significantly greater than that in the UV oxidation alone, and its oxidation was almost halved by the nitrate. However, the nitrate clearly enhanced the DEP oxidation in the O3 oxidation and O3/H2O2 process. Especially, the addition of nitrate almost doubled the DEP oxidation efficiency in the O3/H2O2 process. The series of pilot-scale AOP operations confirmed that about 30-50% of DEP dissolved in the treated MBR effluent streams was, at least, oxidized by the O3 oxidation alone as well as the UV irradiation without H2O2 addition. The UV photolysis of H2O2 was most effective for DEP degradation with an H2O2 concentration of 40 mg/L at a UV dose of 500 mJ/cm2.

Physiological polyamines: simple primordial stress molecules

Physiological polyamines are ubiquitous polycations with pleiotropic biochemical activities, including regulation of gene expression, cell proliferation and modulation of cell signalling. Reports that the polyamines with cytoprotective activities were induced by diverse stresses raised the hypothesis that physiological polyamines may play a role in inducing stress response. In a wide range of organisms, physiological polyamines were not only induced by diverse stresses, such as reactive oxygen species (ROS), heat, ultraviolet (UV) and psychiatric stress but were able to confer beneficial effects for survival. Recent biochemical and genetic evidences show that polyamines can function as an ROS scavenger, acid tolerance factor and chemical chaperone, and positive regulators for expression of stress response genes which may explain their protective functions against diverse stresses. Taken together, these data suggest that physiological polyamines can function as primordial stress molecules in bacteria, plants and mammals, and may play an essential role in regulation of pathogen-host interactions.

Thallium-201 SPECT predicts response to intensity-modulated radiation therapy for recurrent oral squamous cell carcinoma

The aim of this study was designed to investigate the usefulness of thallium-201 single photon emission computed tomography (SPECT) in predicting response of intensity-modulated radiation therapy (IMRT) for recurrent oral squamous cell carcinoma (OSCC).

PATIENTS, METHODS

Thirty-one patients with histologically proven recurrent OSCC were recruited. Before IMRT, all patients underwent SPECT at 15 min and 120 min after intravenous injection 111 MBq of thallous chloride ((201)Tl). Tumour uptake was measured with the semiquantitative early ratio (ER), delayed ratio (DR), and retention index (RI). The patients were classified into responder (complete response and partial response) and non-responder (stable disease and progressive disease) groups according to the tumour response evaluated by the Response Evaluation Criteria in Solid Tumors guidelines.

RESULTS

As comparing DR and RI between the two groups, both parameters were significantly higher in the responder group. When a DR of 1.75 was used as a cutoff value for the responders, the receiver operating characteristic (ROC) analyses revealed sensitivity and specificity of 79% and 75%, respectively. At a cutoff value for the responders of a RI of 78.5%, the ROC analyses showed sensitivity and specificity of 95% and 83%, respectively.

CONCLUSION

Our results suggest that (201)Tl-SPECT, as measured by the DR or RI has clinical potential in predicting response of IMRT for patients with recurrent OSCC. The ROC curve analyses further suggest that RI may be superior to DR in distinguishing responders from non-responders.

Endothelial progenitor cells in pterygium pathogenesis

PURPOSE

The pathogenesis of pterygium is not well known, and controversy exists about the cell origins and the nature of initial trigger required for its development. We investigated whether endothelial progenitor cells (EPCs) are involved in pathogenesis of pterygium and the mechanism underlying the selective recruitment of EPCs during this process.

METHODS

We studied 13 normal controls and 28 pterygium patients (primary (n=15), recurrent (n=13)). Substance-P, vascular endothelial growth factor (VEGF), and stem cell factor (SCF) were measured in plasma and tears using ELISA, and circulating CD34(+) and c-kit(+) mononuclear cells (MNCs) by flow cytometry. Anterior segment fluorescein angiography (FAG) was performed to evaluate hypoxic conditions in the early stage of pterygium. Surgically removed pterygial tissues were analyzed immunohistochemically using the progenitor cell markers, CD34, c-kit, VEGFR-1, and VEGFR-2.

RESULTS

Anterior segment FAG findings showed an increase in non-perfusion areas and attenuated vessels in the nasal limbus during early-stage pterygium. Circulating CD34(+) MNCs and c-kit(+) MNCs were increased in pterygium groups compared with normal controls. Systemic and local cytokines including SP, VEGF, and SCF in pterygium groups were also elevated and showed positive correlations with CD34(+) and c-kit(+) MNC numbers. Immunohistochemical analysis of pterygium showed strong progenitor cell marker immunoreactivities.

CONCLUSIONS

EPCs might be involved in pterygium development, and ocular hypoxia triggers this neovascularization by recruiting EPCs derived from the bone marrow via the production of systemic and local cytokines.

Electron kinetics in radio-frequency atmospheric-pressure microplasmas

The kinetic study of three radio-frequency atmospheric-pressure helium microdischarges indicates that the electron energy probability function is far from equilibrium, and three electron groups with three distinct temperatures are identified. The relative population of electrons in different energy regions is strongly time modulated and differs significantly from values recently reported from fluid analyses. It is also shown that a flux of energetic electrons (epsilon>5 eV) that comprises up to 50% of the total electron flux can reach the electrodes. This energetic electron flux provides a new means of delivering energy to the electrodes and tuning the surface chemistry in atmospheric-pressure discharges. The three electron groups and the engineering of an energetic electron flux might open up a new paradigm in plasma-surface chemistry that has not been considered up until now.

Neuronavigation-Assisted Surgery for Distal Anterior Cerebral Artery Aneurysm

OBJECTIVE

We present our experience with the neuronavigation system as used for surgery of distal anterior cerebral artery (DACA) aneurysm.

METHODS

Between 2001 and 2004, 12 patients with a DACA aneurysm were consecutively treated with direct clipping assisted by the neuronavigation system. We used the BrainLAB Vector Vision neuronavigation system (BrainLAB, Heimstetten, Germany). Seven out of 12 patients presented with subarachnoid hemorrhage. Aneurysms were located at distal A2 in 10 patients and distal A3 in two patients. The size of the aneurysms ranged from 3-10 mm.

RESULTS

There were no procedure-related complications or technical problems during application of the neuronavigation system. The registration accuracy ranged from 0.5-1.5 mm (mean: 0.88 mm). The neuronavigation system provided real-time presentation of the DACA and the aneurysm, and allowed for identification of the DACA aneurysm in all patients. No surgical complications developed, and all 12 patients had a good recovery after direct clipping.

CONCLUSION

Although current neuronavigation systems are not available for all intracranial aneurysms, we believe that the DACA aneurysm is a good candidate for its use. The additional benefits of a small craniotomy and precise intraoperative orientation during surgery result in a minimally invasive aneurysm procedure.

Neuronavigation-Assisted Surgery for Distal Anterior Cerebral Artery Aneurysm

OBJECTIVE

We present our experience with the neuronavigation system used for surgery of distal anterior cerebral artery (DACA) aneurysms.

METHODS

Between 2001 and 2004, 12 patients with a DACA aneurysm were consecutively treated with direct clipping assisted by the neuronavigation system. We used the BrainLAB Vector Vision2 neuronavigation system (BrainLAB, Heimstetten, Germany). Seven out of 12 patients presented with subarachnoid hemorrhage. Aneurysms were located at distal A2 in 10 patients and distal A3 in two patients. The size of the aneurysms ranged from 3 to 10 mm.

RESULTS

There were no procedure-related complications or technical problems during application of the neuronavigation system. The registration accuracy ranged from 0.5 to 1.5 mm (mean: 0.88). The neuronavigation system provided real-time presentation of the DACA aneurysm, and allowed for identification of the DACA aneurysm in all patients. No surgical complications developed, and all 12 patients had a good recovery after direct clipping.

CONCLUSION

Although current neuronavigation systems are not available for all intracranial aneurysms, we believe that the DACA aneurysm is a good candidate for its use. The additional benefits of a small craniotomy and precise intraoperative orientation during surgery result in a minimally invasive aneurysm procedure.

Nanocrystalline diamond thin films deposited from C60 monoenergetic fullerene ion beam

Carbon films 250 division by 500 nm in thickness deposited on Si wafers from mass-selected flow of accelerated C60 ions with energies of 5.0 +/- 0.1 keV at temperatures of 300 K and 673 K are characterized by TEM and nanoindentation. On the TEM images of the films deposited at 673 K, nanocrystalline graphite with the typical grain size of -6 nm is observed. The films deposited at 300 K are transparent in visible light. TEM study of these films has revealed structural elements with lattice spacing close to that of diamond and the grain size of about 4 nm. Nanohardness and elastic modulus of the films prepared at a substrate temperature of 300 K were 23.1 +/- 0.2 GPa and 200 +/- 1 GPa, respectively. Possible mechanisms of the carbon films structure formation are suggested in the framework of a hydrodynamic shock wave model.

Prostate-specific antigen and prostate volume in Korean men with spinal cord injury: a case–control study

STUDY DESIGN

Prospective, cross-sectional, case-control study.

SETTING

Outpatient department in Seoul, Korea.

OBJECTIVES

To assess prostate volume and serum prostate-specific antigen (PSA) levels in Korean men with spinal cord injury (SCI).

METHODS

A total of 31 SCI patients with ages ranging between 45 and 81 years old (median age, 58 years) were studied. Thirty-one age-matched individuals without SCI were enrolled in the study as controls. We tested PSA levels and performed transrectal ultrasonographies on all enrolled patients. Of the patients with SCI, 20 were evaluated for testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels.

RESULTS

Serum PSA levels and prostate volume parameters in the two groups had similar values: the median (5th-95th percentiles) serum PSA level was 1.56 ng/ml (0.12-9.77) for SCI patients and 1.04 ng/ml (0.50-2.98) for controls (P=0.481), whereas the median (5th-95th percentiles) prostate volume was 18.33 ml (10.16-76.78) for SCI patients and 20.80 ml (14.23-41.22) for controls (P=0.072). No significant differences were found when serum PSA levels and prostate volumes were compared according to SCI patient injury characteristics. Testosterone levels were lower than the normal range in 7 SCI patients (35%), LH was higher than the normal range in 10 SCI patients (20%), and FSH was higher than the normal range in eight SCI patients (40%). We observed an age-related increase in FSH levels (r=0.634, P=0.004), although hormone levels did not correlate with serum PSA levels and prostate volume parameters.

CONCLUSIONS

According to our results, serum PSA levels and prostate volume in Korean SCI patients are not different from those in uninjured men and are not affected by injury characteristics.

Abnormal heating of low-energy electrons in low-pressure capacitively coupled discharges

In low-pressure capacitively coupled plasmas, high-energy electrons are collisionlessly heated by large rf fields in the sheaths while low-energy electrons are confined in the bulk plasma by the ambipolar potential. Low-energy electrons are typically inefficiently heated due to their low collisionality and the weak rf electric field present in the bulk. It is shown, however, that as a result of the nonlinear interaction between the electron motion and the weak rf field present in the bulk, low-energy electrons can be efficiently heated. Electrons in the bulk that bounce inside the electrostatic potential well with a frequency equal to the rf excitation frequency are efficiently heated by the coherent interaction with the rf field. This resonant collisionless heating can be very efficient and manifest itself as a plateau in the electron energy probability function.

Predictors of idiopathic thrombocytopenic purpura in pregnant women presenting with thrombocytopenia

OBJECTIVE

Idiopathic thrombocytopenic purpura (ITP) and gestational thrombocytopenia (GT) are common causes of thrombocytopenia during pregnancy. Despite an ever-increasing experience with these disorders, differentiation between the two entities still remains a diagnostic challenge. The current study attempted to identify the antenatal predictors of ITP for pregnant women.

METHODS

Between January 1999 and June 2005, a total of 58 pregnant women with a presumptive diagnosis of either ITP or GT were recruited for the study. All of them had platelet counts of less than 100 x 10(9)/L. The predictors of ITP were evaluated by comparison between the two disorders.

RESULTS

The detection of thrombocytopenia prior to 28 weeks of gestation and platelet counts <50 x 10(9)/L at its diagnosis remained independently predictive of ITP (P<0.001 and P=0.004, respectively). The combined analysis of these two factors provided a 96.0% sensitivity and a specificity of 75.8%.

CONCLUSION

The onset time of thrombocytopenia and platelet count at its presentation remain the strongest predictors of ITP for pregnant women. The combination model using these factors may be useful for the early prediction of ITP.

Serum prostate-specific antigen as a predictor of prostate volume in Korean men with lower urinary tract symptoms

The aim of the study was to assess the utility of prostate-specific antigen (PSA) as a predictor of prostate volume indexes (total prostate volume (TPV), transition zone volume and transition zone index) in Korean men with lower urinary tract symptoms (LUTS). From September 2003 to April 2006, 3431 patients with LUTS were included in the study; they had a median age of 63.8 years, a median prostate volume of 22.6 ml and a median serum PSA of 1.04 ng/ml. Men with a baseline PSA of >10 ng/ml were excluded, to reduce the likelihood of including occult prostate cancer. Prostate volume indexes and serum PSA levels had an age-dependent log-linear relationship. Receiver operating characteristic curve analysis showed that PSA had good predictive value for various prostate volume indexes thresholds. The approximate age-specific criteria for detecting men with a TPV of >40 ml are PSA levels of 1.20, 1.44 and 1.72 ng/ml for men with LUTS in their sixth, seventh and eighth decades, respectively. The results show that serum PSA identifies Korean men with large prostates reasonably well. Korean men may produce and/or release more PSA per unit prostate volume than white men. The cutoffs for PSA and prostate volume to response to LUTS therapy should be determined in this population.

Specific absorbed fraction for Korean adult voxel phantom from internal photon source

Absorbed fraction (AF) and specific absorbed fraction (SAF) are crucial values for the calculation of radionuclide S-values and consequently for internal dose estimates. The formalism of the Medical Internal Radiation Dose (MIRD) committee of the Society of Nuclear Medicine (SNM) has been utilised as a standard in the calculation of individual organ doses for biologically distributed radionuclides and for different types of radiation. Although those quantities are highly sensitive to individual anatomical difference, the SAF dataset calculated by Caucasian-based stylised phantoms have been applied to Korean population until now. This study was intended to calculate the SAFs by using realistic Korean voxel phantom and Monte Carlo transport technique for the first time and compare the results with those of the existing Caucasian-based data and the Korean stylised phantom published recently. The up-to-date realistic Korean voxel phantom, KTMAN-2, which was developed from computed tomography (CT) images of an average Korean adult male, was employed for Monte Carlo calculation using EGSnrc user-code, developed for the purpose of this study. The SAFs for 32 target organs and tissues from the photon source, uniformly deposited in a total of 37 source organs and tissues, were calculated from KTMAN-2. The results were compared with those for an adult phantom of Oak Ridge National Laboratory (ORNL) and Korean adult stylised phantom. Two major reasons of discrepancy were analysed: (1) racial difference between the Korean and the Caucasian and (2) anatomical difference between stylised and voxel phantoms. When the source organ was identical to the target organ, difference in SAF caused by the difference in target-organ mass between the Korean and the Caucasian phantoms was mainly observed. When the source and target organs were not identical, significant difference in SAF was observed which was mainly attributed to the difference in inter-organ distance and organ shape between voxel and stylised phantoms.