The study on photoreflectance characteristic of semi-insulating GaAs surface region by its exposure to 6 MeV electron beam

Photoreflectance measurements were performed to investigate the optical properties in the electron beam irradiation semi-insulating GaAs(e-beam irradiation GaAs) and semi-insulating GaAs(SI-GaAs). A considerable increase of the PR amplitudes has been registered after the e-beam irradiation in comparison with the GaAs. It is that result of a higher electron scattering on the lattice defects created by the e-beam.

A new drug carrier, Nalpha-deoxycholyl-L: -lysyl-methylester, for enhancing insulin absorption in the intestine

AIMS/HYPOTHESIS

The development of an orally active insulin formulation will offer great advantages over conventional injectable insulin therapy in the treatment of patients with diabetes mellitus. Since insulin absorption in the intestine is restricted by the natural physiological characteristics of insulin, we developed a small synthetic compound, Nalpha-deoxycholyl-L: -lysyl-methylester (DCK), as an insulin carrier to enhance oral delivery.

METHODS

Streptozotocin-induced diabetic rats orally received single doses of insulin (42 U/kg) or insulin/DCK formulation (10, 21, 30 and 42 U/kg) under fasting conditions. Blood glucose levels and plasma insulin concentrations were measured for 6 h following the administration of the agents. An OGTT was also performed immediately after the administration of the oral insulin/DCK formulation.

RESULTS

The administration of 21, 30 and 42 U/kg (based on insulin activity) of insulin/DCK formulation reduced plasma glucose levels by up to 33.0% (median; range 30.6-70.2%), 78.5% (39.4-86.8%) and 75.2% (67.0-87.4%), respectively, compared with baseline levels. Furthermore, plasma insulin concentrations were observed to rapidly increase. In the OGTT, the insulin/DCK formulation reduced the AUC0-240 for glucose by 30.8% (22.3-54.9%) (p<0.01), and stabilized glycaemia for up to 4 h.

CONCLUSIONS/INTERPRETATION

The results of this study demonstrate that the insulin/DCK formulation can be absorbed in the intestine and that it is biologically efficacious. We therefore suggest that this oral formulation could be used as an alternative to injectable insulin with enhanced clinical effects.

Liquid Chromatography-Accurate Radioisotope Counting and Microplate Scintillation Counter Technologies in Drug Metabolism Studies

The present study involves an analysis of the performance of liquid chromatography (LC)-accurate radioisotope counting (ARC) and microplate scintillation counter (TopCount) technologies in drug metabolism studies. For the purpose of evaluating these systems, biological samples resulting from the metabolism of a radiolabeled [14C] compound, known as compound B, are analyzed using LC-ARC and TopCount under similar high-performance LC conditions. Counting efficiency is 83% for LC-ARC, 77% for TopCount, and linearity is R2 of 0.9998 versus 0.9984, respectively. The limit of detection for LC-ARC is 12 disintegrations per minute (dpm) with 1-min/fraction counting, yet for TopCount it is 8.7 dpm with 5-min/fraction counting. Under optimal conditions for each, the total run time of LC-ARC is approximately half that of TopCount. These results indicate that there is no significant difference between these two systems in terms of efficiency, linearity, and limit of detection. However, the LC-ARC system does not involve any manual operations, yet TopCount requires manual sample transfer and data import. This study shows that impressive progress has been made in the technology of radioisotope counting in drug metabolism using LC-ARC. This system enhances the resolution of radiochromatograms and is able to measure volatile metabolites that TopCount cannot detect at all. The ability to acquire mass spectra online is also a major advancement. The overall results suggest that the combination of LC-ARC with radioactivity detection and mass spectrometry has great potential as a powerful tool for radioisotope measurement in metabolite identification studies during drug discovery and development.

Quantitative Analysis of Interleukin-6 Expression in Porcine Spleen Cells and Alveolar Macrophages using Real-Time PCR

Interleukin-6 (IL-6), a multifocal cytokine produced by lymphoid and non-lymphoid cells, regulates immune responses, acute-phase reactions against bacterial infections, and haematopoiesis. After cloning and sequencing of porcine IL-6, the expression pattern of porcine IL-6 mRNA was evaluated through real-time RT-PCR using porcine immune cells (spleen cells and alveolar macrophages) following stimulation with LPS. The sequence has been reported to GenBank with Accession no. AF 518322. The nucleotide sequence was different at the 89th and 205th positions in comparison with M80258, but only at the 205th with M86722. Comparison of porcine IL-6, Accession no. AF 518322, with IL-6 of human, canine, ovine, and mouse showed homologies of 78%, 81%, 82% and 73% in nucleotide sequence and 42%, 69%, 61% and 42% in amino acids. Expression of IL-6 mRNA was induced by stimulation with LPS. IL-6 mRNA expression in alveolar macrophages peaked at 2 h and decreased sharply to control levels at 4 h, whereas it peaked at 14 h and decreased at 24 h in spleen cells after stimulation with LPS (1 microg/ml). These results suggest that IL-6 mRNA expression in porcine immune cells is cell-type specific and the results of this study could be used as the basis for research on the porcine immune system.

Uterine artery embolization for adenomyosis without fibroids

AIM

To evaluate the potential usefulness of transcatheter uterine artery embolization as a treatment for symptomatic adenomyosis in patients without uterine fibroids.

MATERIALS AND METHODS

Uterine artery embolization using polyvinyl alcohol particles sized 250-710 mm was performed in 43 patients (mean; 40.3 years, range; 31-52 years) with dysmenorrhoea, menorrhagia, or bulk-related symptoms (pelvic heaviness, urinary frequency) due to adenomyosis without fibroids. All patients underwent pre-procedural and 3.5 months (range 1-8 months) follow-up magnetic resonance imaging (MRI) with contrast enhancement. Clinical symptoms were also assessed at the time of MRI before and after embolization.

RESULTS

Significant improvement of dysmenorrhoea (95.2%) and menorrhagia (95.0%) was reported in most patients. Contrast-enhanced MRI revealed non-enhancing areas suggesting coagulation necrosis of adenomyosis in 31 patients (72.1%), decreased size without necrosis in 11 patients (25.6%), and no change in one patient (2.3%). The mean volume reduction of the uteri after uterine artery embolization was 32.5% (from 321.7+/-142.9 to 216.7+/-130.1 cm(3)).

CONCLUSION

Transcatheter uterine artery embolization is an effective therapy for the treatment of symptomatic pure adenomyosis, and may be a valuable alternative to hysterectomy.

Method for producing coded micro-carrier and test method by using a novel type biochip

This paper provides a method for producing a novel type coded micro-carrier. A simple and cost effective solution for bio-molecule applications was developed. Application relevant items such as manufacture process, biospecific interaction, and analysis method are discussed. For low cost fabrication, the use of LIGA-like process is suggested. LIGA-like process is used as a dry patterning process in which an intense beam of light from an excimer laser is used to pattern a material directly. This process has found extensive application in the microelectronics industry for patterning of polymer materials. The use of LIGA-like techniques offers two attractive features: first, we can cut the polymer into many tiny micro-carriers with micrometer precision. Second, LIGA-like process allows to encode with high precision spatial information onto the micro-carrier that can be used in the identification of the bio-molecule. This paper gives a description of the basic idea, describes the fabrication of the novel micro-carrier that we called "coded micro-carrier," and of the image processing algorithms used for the analysis of bio-molecules. This study also provides a test method for identifying a bio-molecule, which includes mixing several coded micro-carriers with the hybridized unknown bio-molecules; and identifying the codes on the micro-carrier via image recognition system. The numbers and types of the known micro-carrier can be flexibly adjusted according to the number of tested bio-molecules.

On-line liquid chromatography-accurate radioisotope counting coupled with a radioactivity detector and mass spectrometer for metabolite identification in drug discovery and development

A novel detection method combining on-line liquid chromatography-accurate radioisotope counting (LC-ARC, advanced stop flow controller) coupled with a radioactivity detector and mass spectrometer has been developed. One of the major benefits of this method is that this system enhances the sensitivity of radioisotope measurement for metabolite identification in drug metabolism studies. Another advantage to this system is the easy interface with the mass spectrometer, which allows acquisition of mass spectrometric data on-line. For purposes of evaluating this system, in vitro microsomal incubations with [3Hlpropranolol were conducted. On-line separation and identification of [3H]propranolol metabolites was achieved without intensive sample preparation, concentration, or fraction collection. Mass spectrometric analysis showed the presence of propranolol major metabolites formed by hydroxylation, correlating with previously published results. Further evaluations of this system also were conducted using two 14C compounds, which are herein labeled X and Y. As our results show, 14C peaks were detected down to 6 cpm, which is approximately 20 times more sensitive than commercially available flow through radioactivity detectors. The overall results suggest that the combination of LC-ARC with radioactivity detection and mass spectrometry has great potential as a powerful tool for improving the sensitivity of radioisotope measurement in metabolite identification studies during drug discovery and development.

Development of the Korean version of Alzheimer's Disease Assessment Scale (ADAS-K)

OBJECTIVE

The purpose of this study was the development of the Korean Version of Alzheimer's Disease Assessment Scale (ADAS-K).

METHOD

ADAS-K was administrated to 84 AD patients as well as 105 non-demented control subjects. Three aspects of reliability were tested. To evaluate the validity of ADAS-K, discriminant validity and concurrent validity were tested. To evaluate the sensitivity of ADAS-K to disease severity, all subjects, AD patients and control subjects, were grouped by CDR scale and their mean scores on ADAS-K were compared.

RESULT

ADAS-K demonstrated high levels of reliability. Mean ADAS-K scores for AD patients were significantly different from the control group (p < 0.01). Furthermore, ADAS-K exhibited significant correlations with other tests and scales (range 0.45-0.85, p < 0.01). In ROC curve analysis, ADAS-K displayed high diagnostic efficacy and the optimal cut-off point was selected between 18/19. ADAS-K was able to discriminate the degree of AD severity according to CDR classification. Our results suggested that ADAS-K-cog was sensitive to very mild AD.

CONCLUSION

We demonstrated that ADAS-K is a reliable and valid instrument not only for AD diagnosis but also for evaluation of its severity.

Apolipoprotein E epsilon 4 allele is not associated with the cognitive impairment in community-dwelling normal elderly individuals

OBJECTIVES

The aim of this study was to examine whether the APOE epsilon 4 allele also confers a risk for the cognitive impairment in normal aging.

METHODS

We administered all the eight neuropsychological tests from the CERAD neuropsychological battery to the CVD-free, community-dwelling normal elderly individuals, and compared their performance by the occurrence of the APOE epsilon 4 allele.

RESULTS

Either the impact of APOE epsilon 4 allele itself or its interaction terms with age and gender of the subjects did not influence the performance of the eight neuropsychological tests (epsilon p > 0.1 by ANCOVA).

CONCLUSIONS

The APOE epsilon 4 allele is not a risk factor for the cognitive decline in normal elderly individuals regardless of age and gender.

The domain-specific, stage-limited impact of the apolipoprotein E epsilon-4 allele on cognitive functions in Alzheimer's disease

To examine the impact of the APOE epsilon4 allele on the cognitive functions of Alzheimer's disease (AD) patients, we administered the eight neuropsychological tests from the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery to 118 Korean AD patients. The impact of the APOE epsilon4 allele was significant in the Word List Recall Test (WLRT) and the Word List Recognition Test (WLRcT) only, and its impact was confined to the very mild AD (VMAD) patients (F = 7.65, d.f. = 2, p < 0.01 for WLRT; F = 3.27, d.f. = 2, p = 0.04 for WLRcT). In the VMAD group, the performance on the two tests of the APOE-epsilon4-positive patients was poorer than that of the APOE-epsilon4-negative patients. Our findings suggest that the impact of the APOE epsilon4 allele on cognitive functions in AD may be domain specific and confined to the early stage of AD.

Neither the butyrylcholinesterase K variant nor transferrin C2 variant confers a risk for Alzheimer's disease in Koreans

To investigate the possible involvement of the butyrylcholinesterase (BCHE) K variant and transferrin (TF) C2 variant in the manifestation of Alzheimer's disease (AD), we analyzed the BCHE, TF and apolipoprotein E (APOE) genotypes of 164 sporadic AD patients and 239 normal elderly controls. The frequencies of the BCHE K and TF C2 did not differ between the AD patients and controls (P > 0.1). The occurrence of the APOE epsilon4 did not influence the distribution of the BCHE K and TF C2 variants (P > 0.1). No linkage disequilibrium between the BCHE K and TF C2 was observed either in both the AD patients and controls (P > 0.1). In conclusion, neither the BCHE K nor the TF C2 confers a risk for AD.

Percutaneous peritoneovenous shunt creation for the treatment of benign and malignant refractory ascites

Peritoneovenous shunt placement has been reported as a treatment of refractory ascites by general surgeons, but without a clearly established role. The authors successfully inserted shunts under ultrasonographic and fluoroscopic guidance in 12 patients who had symptomatic refractory ascites (nine men, three women; mean maintenance duration, 88.5 d). Nine patients had advanced liver cirrhosis (five with superimposed hepatoma). Other patients had stomach cancer, colon cancer, and complicated polycystic kidney disease. The mortality rate was 83%. Causes of death included bleeding from preexisting varices, sepsis, hepatic failure, rupture of hepatoma, and disseminated intravascular coagulation. The authors describe the feasibility, technical details, and short-term results of percutaneous peritoneovenous shunt placement.

Pulmonary peptide delivery: effect of taste-masking excipients on leuprolide suspension metered-dose inhalers

The purpose of this study was to evaluate the effect of taste-masking excipients on in vitro and in vivo performance of a leuprolide metered-dose inhaler (MDI) suspension formulation. Taste-masking excipients (aspartame and menthol) were added to a leuprolide suspension MDI formulation. The leuprolide MDI formulation with the taste-masking excipients was characterized in terms of milling time, particle size distribution, dose delivery and uniformity, and drug absorption in dogs. The data were compared with a formula that did not contain taste-masking excipients. It was found that the longer milling time for the leuprolide suspension with the taste-masking excipients was required to obtain a similar particle size distribution compared with the formula without taste-masking excipients using a fluid energy mill. Although measurable differences in mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) were not observed between the two formulations, the percent of particles < or = 5 microns and the actuator retention for the formula with the taste-masking excipients were significantly different from the formula without taste-masking excipients using the Marple-Miller cascade impactor. Taste-masking excipients did not show a significant effect on valve delivery and through-can dose uniformity. However, the mean ex-actuator dose was 150.4 mg for the formula with the taste-masking excipients and 162.2 mg for the reference formula, respectively, indicating a significant difference. In tracheostomized dogs, both formulations showed comparable pharmacokinetic parameters including Cmax, Tmax, AUC0-12 and bioavailability (F%), indicating that the taste-masking excipients do not have an effect on lung absorption of leuprolide acetate. Therefore, inclusion of taste-masking excipients in the leuprolide MDI suspension formulation showed a significant impact on drug micronization, exactuator dose, and particle deposition pattern. Mechanistically, the unfavorable performance of leuprolide MDI in the presence of taste-masking excipients could be due to modification of the properties of the suspension itself and alteration of propellant evaporation following actuation.

Expression of the insulin-like growth factors (IGFs) and the IGF-binding proteins (IGFBPs) in human gastric cancer cells

Insulin-like growth factor (IGF)-I and -II are potent mitogens and postulated to exert autocrine, and paracrine effects on growth regulation in human gastric cancer. Their mitogenic effects are tightly regulated by the IGF binding proteins (IGFBPs). In this study, we evaluated the mRNA expression of IGF-I, IGF-II and the IGFBPs in a panel of human gastric cancer cell lines, and normal and tumour tissue specimens from patients with gastric cancer by reverse transcriptase-polymerase chain reaction (RT-PCR) and competitive PCR. Conditioned media (CM) of the gastric cancer cell lines were studied for the secretion of the IGFBPs by western ligand blot (WLB) and western immunoblot (WIB). IGF-I and IGF-II were expressed in all of the gastric cancer cell lines, and the normal and tumour tissue specimens. Overexpression of the IGFs, in particular, IGF-II, was observed in the tumour tissues. The expression pattern of IGFBPs was heterogeneous among the gastric cancer cell lines. IGFBP-2 was expressed in all of the gastric cancer cell lines, whereas IGFBP-1 was not detected in any cell lines. IGFBP-4 was expressed in the most of cell lines. IGFBP-3, IGFBP-5 and IGFBP-6 were expressed in approximately 50% of cell lines. In addition, exogenous IGF-I and IGF-II stimulated the proliferation of gastric cancer cells, suggesting the existence of a functional IGF system in gastric cancer. Taken together, our data-suggest that the IGF-IGFBP system may play an important role in the initiation, progression and metastasis of gastric cancer. Further studies are needed to understand the exact role of IGFs and IGFBPs in gastric neoplasia.

Suppression of tumorigenicity and metastasis in B16F10 cells by PTEN/MMAC1/TEP1 gene

PTEN/MMAC1/TEP1 (PTEN) is a tumor suppressor gene that is mutated in a variety of advanced and metastatic cancers, strongly suggests that PTEN alteration is possibly involved in the tumor progression and formation of metastases. However, the roles of PTEN in tumor growth and metastasis and its functional mechanisms are not fully understood. We evaluated the tumor suppressor function of PTEN gene on tumor growth and metastasis in vitro and in vivo. Our results of in vitro soft agar assay and in vivo PTEN-expressing tumor cell growth showed that PTEN inhibited the tumorigenicity of B16F10 melanoma cells. Anti-metastatic function of PTEN was also revealed by experimental pulmonary metastatic animal model. For the further insight into the mechanisms underlying the PTEN-mediated inhibition of tumor metastasis, we have examined the role of PTEN on the secretion of matrix metalloproteinases (MMPs), insulin-like growth factors (IGFs) and the expression of secretory and cellular vascular endothelial growth factor (VEGF) proteins that have been described to contribute to the metastasis of tumor. PTEN significantly lowered MMPs and IGFs secretion and also expression of secretory and cellular VEGF proteins. These results suggest that PTEN tumor suppressor protein inhibits tumorigenicity and metastasis through regulation of MMP, IGFs, and VEGF expression.

Mutational effects on thermostable superoxide dismutase from Aquifex pyrophilus: understanding the molecular basis of protein thermostability

We designed two mutants of superoxide dismutase (SOD), one is thermostable and the other is thermolabile, which provide valuable insight to identify amino acid residues essential for the thermostability of the SOD from Aquifex pyrophilus (ApSOD). The mutant K12A, in which Lys12 was replaced by Ala, had increased thermostability compared to that of the wild type. The T(1/2) value of K12A was 210 min and that of the wild type was 175 min at 95 degrees C. However, the thermostability of the mutant E41A, which has a T(1/2) value of 25 min at 95 degrees C, was significantly decreased compared to the wild type of ApSOD. To explain the enhanced thermostability of K12A and thermolabile E41A on the structural basis, the crystal structures of the two SOD mutants have been determined. The results have clearly shown the general significance of hydrogen bonds and ion-pair network in the thermostability of proteins.

Fumonisin B(1) induces apoptosis in LLC-PK(1) renal epithelial cells via a sphinganine- and calmodulin-dependent pathway

Fumonisins are a family of mycotoxins produced by Fusarium moniliforme, which is the most common mold found on corn throughout the world. These compounds are both toxic and carcinogenic for animals, and perhaps humans, with the kidney being the most sensitive organ to fumonisin toxicity. The molecular mechanism of fumonisin toxicity appears to involve disruption of de novo biosynthesis of sphingolipids and accumulation of sphinganine. The goals of this study were to determine whether fumonisin B(1) kills LLC-PK(1) renal kidney epithelial cells by inducing apoptosis and to identify genes affected by sphinganine that mediate fumonisin B(1)-induced cell death. Fumonisin B(1) produced morphological changes (i.e., cell shrinkage, membrane blebbing) and time-dependent increases in DNA fragmentation demonstrating that the toxin induces apoptosis. Simultaneously, fumonisin B(1) blocked sphingolipid biosynthesis and caused accumulation of sphinganine. To further investigate the role of sphinganine in fumonisin B(1)-induced apoptosis, beta-fluoroalanine (betaFA) was used to inhibit serine palmitoyltransferase, which catalyzes an earlier step in the sphingolipid biosynthetic pathway. betaFA blocked sphinganine accumulation and prevented fumonisin B(1)-induced DNA fragmentation, confirming that apoptosis induced by fumonisin B(1) is dependent upon accumulation of sphinganine. To examine gene expression, differential display reverse transcriptase polymerase chain reaction (DDRT-PCR) was applied to RNA isolated after 16 h of exposure to fumonisin B(1). Differential expression in response to fumonisin B(1) of a gene identified as calmodulin has been verified by Northern analysis. Sphinganine appears to mediate the effect because betaFA reduces induction of calmodulin mRNA by fumonisin B(1). Fumonisin B(1) also increases calmodulin protein in a concentration-dependent manner and the calmodulin antagonist W7 blocks fumonisin B(1)-induced DNA fragmentation, supporting a role for calmodulin in fumonisin B(1)-induced apoptosis. In contrast, fumonisin B(1) had no effect on expression of bcl-2 family genes (bax, bcl-2, and bcl-x). These findings demonstrate that fumonisin B(1) kills LLC-PK(1) kidney cells by inducing apoptosis. Further, the results establish a sequence of events for fumonisin B(1)-induced apoptosis involving initial disruption of sphingolipid metabolism and accumulation of sphinganine (or a metabolite), which, in turn, induces expression of calmodulin.

The effect of 2,5,2',5'-tetrachlorobiphenyl on growth and death of the cyanobacterium Anabaena flos-aquae

The effect of 2,5,2',5'-tetrachlorobiphenyl (TcBP) on cell death was investigated in the cyanobacterium Anabaena flos-aquae (Lyngb.) Bréb grown in a P-limited, semicontinuous culture under N2-fixing conditions during a 17-d period. The TcBP was supplied daily to yield final concentrations of 1, 10, and 100 ppb (or ng/ml). At 1 and 10 ppb, the population size of live cells (sum of live vegetative cells and live heterocysts) was not different from that of the TcBP-free controls (p > 0.1, t test) and remained constant both in its absolute value (9.6 X 10(5) cells/ml) and as a percentage of the total population (98.6%). However, at 100 ppb, the population size of live cells declined significantly after the 11th day (8.2 x 10(5) cells/ml, or 96.6% of total population; p < 0.01, t test). The decrease in viable cells was mostly found in vegetative cells. Bioconcentration factor in the cell ([pg TcBP/g dry wt cells]/[pg TcBP/ml]) was 1.23 x 10(5).

Aortic and arterial aneurysms in behçet disease: management with stent-grafts--initial experience

PURPOSE

To assess the application of stent-grafts in the management of aortic and arterial aneurysms in patients with Behçet disease.

MATERIALS AND METHODS

Nine aneurysms in seven patients were managed with various types of stent-grafts. Diagnoses were based on clinical findings. The aortic aneurysms (n = 3) were thoracic (n = 1), suprarenal (n = 1), or infrarenal (n = 1). The arterial aneurysms (n = 6) were in the right and left subclavian (n = 2), right common carotid (n = 2), right brachiocephalic (n = 1), or left common iliac arteries (n = 1). A tandem connection of Gianturco stent covered with polytetrafluorethylene was placed in three aneurysms, and a balloon-expandable stent was placed in six.

RESULTS

The stent-graft was successfully placed in all patients. Immediate follow-up angiography revealed complete exclusion of the aneurysm in all cases. Follow-up computed tomography performed 3 days to 2 weeks later revealed complete exclusion and thrombosis of the aneurysm and patency of the stent-graft in six patients. In one patient, total occlusion of the artery with a stent occurred due to flow disturbance caused by double lesions. During follow-up (range, 6-59 months; mean, 28 months), the aneurysm resolved and completely regressed in four patients. A recurrent aneurysm at the distal margin of previously inserted stent-graft was successfully managed with an additional stent-graft.

CONCLUSION

The findings in this initial experience suggest that stent-graft insertion may be a safe and effective alternative to surgical treatment of aortic and arterial aneurysms in patients with Behçet disease.

Neurologic outcomes of pediatric epileptic patients with pentobarbital coma

Status epilepticus is a life-threatening condition requiring emergent medical attention. Although initial therapies with antiepileptic drugs generally terminate seizures within 30 to 60 minutes, patients with refractory status epilepticus require additional intervention. High-dose pentobarbital has been the most commonly prescribed agent for the management of refractory status epilepticus in children. The objective of this research was to evaluate the association between the response of pentobarbital coma and neurologic outcomes in refractory status epilepticus. Twenty-three subjects were treated with pentobarbital coma for at least 48 hours. Medical records were reviewed to collect patient demographic information, responses to treatment, and neurologic outcomes. Among the 23 patients reviewed, 12 patients were controlled with pentobarbital (responders), six were unresponsive to pentobarbital (nonresponders), and five patients relapsed after discontinuation or during tapering of pentobarbital (relapser). The mortality rate among the relapser and nonresponder groups combined was 90.9%, but no deaths occurred among the responder group (P < 0.001). The survival rate was greater among toddlers compared with neonates or older children. Failure of seizure control after pentobarbital coma was associated with a poor prognosis. The potential for serious complications of pentobarbital therapy among neonates highlights the need for careful dosing in this age group.

Aortic dissection: percutaneous management with a separating stent-graft--preliminary results

The authors used a separating stent-graft to treat Stanford type B aortic dissection. The separating stent-graft consists of two stents: a stent-graft and an inner bare stent. The separating stent-graft has three parts: a proximal stent, a graft made of synthetic polyester textile fiber, and a distal stent. A 12-F introducing sheath was used. After the separating stent-graft was placed, false-lumen thrombosis was evident in all six patients during a follow-up period of 206 days. The major advantages of this technique are that a cutdown and blood pressure control are not required.

Transferrin C2 variant does not confer a risk for Alzheimer's disease in Koreans

We analyzed the transferrin (TF) and apolipoprotein E (APOE) genotypes of 164 probable Alzheimer's disease (AD) patients and 239 cognitively normal elderly controls in Koreans. We failed to detect a significant difference in genotypic frequencies and allelic frequencies of the TF polymorphism between the AD group and control group (P>0.1 by Chi square test). The frequency of the TF C2 variant did not differ by the diagnosis when the APOE epsilon4-positive subjects and APOE epsilon4-negative subjects were analyzed separately (P>0.1 by Chi square test). The TF C2 variant did not influence the age-at-onset of AD independently or synergistically with the occurrence of the APOE epsilon4 allele (P>0.1 by ANOVA). The TF C2 variant did not confer a risk for AD in Koreans.

Elective endovascular treatment of descending thoracic aortic aneurysms and chronic dissections with stent-grafts

PURPOSE

To report our experience of endovascular stent-graft placement in patients with descending thoracic aortic dissections and aneurysms and to evaluate the feasibility, safety, and clinical outcomes of the treatment.

MATERIALS AND METHODS

Stent-grafts were placed in the descending thoracic aortas of 23 patients with saccular aneurysms (n = 11) and Stanford type B chronic aortic dissections of the descending thoracic and abdominal aorta (n = 12). All stent-grafts were individually constructed of self-expandable stainless steel stents covered with polytetrafluoroethylene. Vascular access was achieved through the femoral artery in all patients. Clinical status of each patient was monitored and postoperative CT was performed within 1 month of the procedure and at 3-12-month intervals after the procedures.

RESULTS

Successful exclusion of the primary entry tears of dissections and the inlets of saccular aneurysms was achieved in all but two patients with aortic dissection. The overall technical success rate was 91.3% (dissection: 10 of 12 = 83%; aneurysm: 11 of 11 = 100%). All patients in whom technical success was achieved showed complete thrombosis and significant decrease in diameter of the thoracic false lumen (preoperative: 5.3 cm +/- 0.9; postoperative: 4.3 cm +/- 0.9; P = .004) or aneurysm sac (preoperative: 5.3 cm +/- 1.7; postoperative: 2.8 cm +/- 2.5; P = .001). In addition, five patients demonstrated complete resolution of the dissected thoracic false lumen (n = 2) and aneurysm sac (n = 3). However, in all patients with aortic dissection, the abdominal aorta was not significantly changed in size (P = .302) and shape and their false lumen flows remained persistent. Immediate postoperative complications were detected in 12 patients (52%); 10 had fever, leukocytosis, and elevation of C-reactive protein, another had wound infection, and another had transient abdominal pain. Three patients died 2, 3, and 12 months after the procedure: one from septic shock, another from underlying mediastinitis, and the other from an unexplained cause. The remaining 20 patients were well after the procedure (1-9 days; mean, 3 days), without any stent-graft-related complications or discomfort (follow up period: 10-65 mo; mean: 25.1 mo +/- 15.6). The cumulative survival rate after the stent graft was 100% at 30 days and 91% at 12 months.

CONCLUSIONS

For treatment of aortic dissection and saccular aneurysm of the descending thoracic aorta, endovascular stent-graft repair may be a technically feasible and effective treatment modality.