Reproducible fabrication of miniaturized glucose sensors: preparation of sensing membranes for continuous monitoring

The immobilization process of glucose oxidase(GOx) in the poly(1,3-diaminobenzene) (poly(1,3-DAB)) network was closely investigated in situ using an electrochemical quartz crystal microbalance(EQCM). GOx captured in approximately 50 nm thick poly-1,3-DAB layer causes a 514 Hz frequency increase, corresponding to 541 ng, and distributes mostly in the outer part of the polymer film. The presence of poly-L-lysine and glutaraldehyde during electropolymerization of poly(1,3-DAB) improves sensitivity by raising the amount of GOx immobilized. Adding a protective membrane on to the enzyme layer from poly(tetrafluoroethylene) (PTFE) dispersed in aqueous media lets the entire fabrication procedure finish perfectly without nonaqueous solvent. The finalized needle-type glucose sensors show competent functions in sensitivity, stability, biocompatibility, lifetime, interference and reproducibility.

Prenatal exposure to magnetic field increases dopamine levels in the striatum of offspring

1. The putative effects of prenatal exposure to magnetic field (MF) have recently received much interest. In the present study, mice were exposed to a MF of 50 mT during gestation (0-19 days). 2. After the exposure was terminated, mothers and offspring were returned to normal laboratory conditions. We then determined changes in striatal levels of dopamine (DA) and its metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) in the offspring. 3. Our results indicate that prenatal exposure to MF increases levels of DA and DOPAC in the striatum at 4, 8 and 12 weeks postnatally.

BAPTA/AM, an intracellular calcium chelator, induces delayed necrosis by lipoxygenase-mediated free radicals in mouse cortical cultures

1. Disruption of calcium homeostasis during neurodegenerative diseases is known to trigger apoptotic or necrotic death in neuronal cells. Recently, the authors reported that intracellular calcium restriction by NMDA receptor antagonists induces apoptosis in cortical cultures. To evaluate whether further restriction of intracellular free calcium can induce apoptosis or necrosis, we examined the neurotoxic characterization of BAPTA/AM, a permeable free calcium chelator, in mouse cortical cultures. 2. Exposure of mixed (glia and neuron) cortical cultures (DIV 13-16) to 3-10 microM BAPTA/AM (non-toxic concentration for glial cells) for 24-48 hr resulted in delayed and necrotic neuronal death. The necrotic findings included swelling and loss of mitochondria and endoplasmic reticulum (ER) with neuronal membrane rupture 24 hr after treatment with BAPTA/AM. Simultaneously, we observed a few TUNEL-positive cells in the neuronal subpopulation of the same cultures. 3. The neurotoxicity evoked by BAPTA/AM (10 microM) was significantly attenuated by the addition of 0.5 microM cycloheximide (a protein synthesis inhibitor), 10 microM actinomycin D (an RNA transcription inhibitor), a high extracellular potassium concentration (total 15 mM KCl), 100 microM t-ACPD (a metabotrophic agonist), 100 microM alpha-tocopherol (a free radical scavenger), 100 microM deferoxamine (a ferric ion chelator), 100 microM L-NAME (a nitric oxide synthase (NOS) inhibitor), 50 microM DNQX (a non-NMDA receptor blocker), and 3-30 microM esculetin (a lipoxygenase inhibitor). However, 0.3-3 mM ASA (a cyclooxygenase inhibitor), 100 ng/ml nerve growth factor (NGF), 10 microM MK-801 (a NMDA receptor antagonist), 20 microM zVAD-fmk (caspase inhibitor) and 50 U/ml catalase failed to inhibit the injury. 4. However, NGF and catalase blocked the neurotoxicity induced by BAPTA/AM in young neuronal cells (DIV 6). BAPTA/AM (10 microM) did not alter the expression of inducible nitric oxide synthase (iNOS) on glial cells. 5. These results suggest that the feature of neuronal death induced by BAPTA/AM exhibits predominantly delayed necrosis mediated by lipoxygenase-dependent free radicals.

Infectivity of Cryptosporidium parvum oocysts following cryopreservation

This study was undertaken to investigate the cryopreservation of Cryptosporidium parvum oocysts. Oocysts purified from mouse feces were suspended in distilled water, 10% glycerin, and 2.5% potassium dichromate. They were stored at -20 C and -80 C for 2, 7, and 30 days, respectively. In addition to the purified oocysts, the feces of C. parvum-infected mice were preserved under the same conditions described above. Purified and fecal oocysts were thawed at 4 C, and their viability was assessed by a nucleic acid stain, excystation test, tissue culture infectivity test, and infectivity to immunosuppressed adult mice. Oocysts purified from fecal material prior to cryopreservation lost most of their viability and all of their infectivity for tissue culture and mice. However, when oocysts were cryopreserved in feces, between 11.7 and 34.0% were judged to be viable and retained their infectivity for mice when stored at -20 C (but not -80 C) for 2, 7, and 30 days. Clearly, fecal material provides a cryoprotective environment for C. parvum oocysts stored at -20 C for at least 30 days.

Polysaccharide isolated from the radix of Platycodon grandiflorum selectively activates B cells and macrophages but not T cells

Many polysaccharides isolated from plants are considered to be biological response modifiers and have been shown to enhance various immune responses in vivo and in vitro. Here, we demonstrate that polysaccharide isolated from the radix of Platycodon grandiflorum (PG) has a unique mode of immunostimulation with regard to its cell-type specificity. PG was found to markedly increase polyclonal IgM antibody production and the proliferation of B cells, and to activate iNOS transcription and NO production in macrophages. Moreover, the intraperitoneal administration of PG in mice resulted in increased IgM antibody production in B cells, which were immunized by using T-dependent antigen sheep red blood cells (sRBCs). However, PG did not affect the proliferation of T cells, the IL-2 expression of Th1 cells, or the IL-4 expression of Th2 cells. Although PG and lipopolysaccharide (LPS) had a similar mode of action in B cells and macrophages, they were differentiated by the fact that PG-induced cellular activation was not inhibited by polymyxin B, a specific inhibitor of LPS. Anti-CD19 or anti-CD79b antibody blocked B cell proliferation and anti-CD14 or anti-CD 11b antibody decreased macrophage NO production, indicating the possible cellular binding sites of PG. Our results demonstrate that PG is a specific activator of B cells and macrophages but not of T cells, and suggest that PG is quite distinct from other well-known immunostimulants, such as lentinan and schizophyllan, which mainly act upon macrophages and T cells.

Light, carbon dioxide, and octenol-baited mosquito trap and host-seeking activity evaluations for mosquitoes in a malarious area of the Republic of Korea

Two field trials for commercially available and experimental mosquito traps variously baited with light, carbon dioxide, octenol, or combinations of these were evaluated in a malarious area at Paekyeon-Ri near Tongil-Chon (village) and Camp Greaves, Paju County, Kyonggi Province, Republic of Korea. The host-seeking activity for common mosquito species was determined using hourly aspirator collections from a human- and propane lantern-baited Shannon trap. The total number of mosquitoes and number of each species captured during the test were compared using 8 x 8 and 5 x 5 Latin square designs based on trap location. Significant differences were observed for the total number of mosquitoes collected in the 8 x 8 test, such that counterflow geometry (CFG) with CO2 > or = CFG with CO2 and octenol > or = Shannon trap > or = Mosquito Magnet with octenol > American Biophysics Corporation (ABC) light trap with light, CO2 (500 ml/min), and octenol > or = ABC light trap with light and dry ice > or = ABC light trap with light and CO2 > ABC light trap with light only. A concurrent 5 x 5 test found significant differences in trap catch, where Mosquito Magnet with octenol > New Jersey light trap > or = EPAR Mosquito Killer with CO2 > or = ABC light trap with light and dry ice > Centers for Disease Control (CDC) light trap (manufactured by John W. Hock) with light and octenol. Significant differences in trap catch were noted for several species including: Aedes vexans, Anopheles sinensis, An. yatsushiroensis, An. lesteri, Culex pipiens, and Cx. orientalis. Traps baited with octenol captured significantly fewer Cx. pipiens than those not baited with octenol. Likewise, no Cx. orientalis were captured in octenol-baited traps. Host-seeking activity showed a similar bimodal pattern for all species captured. Results from these field trap evaluations can significantly enhance surveillance efforts. Significantly greater numbers of mosquitoes were captured with mosquito traps using counterflow technology (e.g., Mosquito Magnet and CFG traps) when compared to standard light and carbon dioxide-baited traps. Additionally, field evaluations demonstrate that various traps can be utilized for isolation and detection of arboviruses and other pathogens.

Source of errors in the evaluation of early rectal cancer by endoluminal ultrasonography

PURPOSE

Although preoperative evaluation of early rectal cancers can be done by endoluminal sonography and by means of colonoscopic findings, it is still controversial whether endoluminal sonography can effectively discriminate mucosal from submucosal lesions. This study was performed to verify objective causes of errors in the evaluation of early rectal cancer (T0/1) using a review of videotaped endoluminal sonography images.

METHODS

Eighty-nine patients with suspected early rectal cancer on endoluminal sonography were included. Two different scanners with appropriate probes were used according to tumor location, i.e., transrectal ultrasonography was used to scan up to 8 cm of the rectum above the anal verge, whereas endoscopic ultrasonography was used to assess higher lesions. Endoluminal sonography images were correlated with histologic infiltration and were reevaluated carefully to identify sources of errors.

RESULTS

Sensitivity and specificity were 83.1 and 96.5 percent, respectively, for tumor staging, whereas sensitivity was very low compared with specificity (16.7 vs. 90.2 percent) for metastatic lymph nodes. Endoluminal sonography images showed irregularity of the underlying tumor border (P < 0.01) and hypoechoic blurring or cutoff of the inner and outer hypoechoic layers (P < 0.001), all of which closely correlated with histologic infiltration of tumor cells. Overstaging occurred more than twice as often as understaging in tumor reevaluation (14 vs. 5 occurrences). In contrast to tumors, lymph nodes showed a similar amount of both overstaging (four cases) and understaging (five cases). The sources of errors were summarized as five types: false instrumentation, interpretive errors, anatomic defects, imaging failure, and inevitable errors.

CONCLUSIONS

Because false instrumentation, interpretive errors, and anatomic defects were considered preventable, 23 (82.1 percent) of the 28 errors might have been avoided. Therefore, a clear image by endoluminal sonography can effectively distinguish mucosal from submucosal lesions in early rectal cancer.

A case of glomerulonephritis in association with pyogenic liver abscess

Glomerulonephritis associated with visceral abscess is being increasingly recognized. The association of glomerulonephritis with visceral suppuration in the absence of endocarditis was first described by Whitworth and associates. Abscesses were most frequently located in the respiratory tract but have been reported at numerous other sites, including appendix, uterus, aorto-femoral bypass graft and cutaneous wound. This report documents the apparently rare occurrence of glomerulonephritis with acute renal failure in association with pyogenic liver abscess. The need for awareness of glomerulonephritis as a cause of acute renal failure in pyogenic liver abscess is highlighted.

Vascular endothelial growth factor in the serum of patients with non-small cell lung cancer: correlation with platelet and leukocyte counts

BACKGROUND

Vascular endothelial growth factor (VEGF) is a potent angiogenic peptide expressed in a wide variety of tumors, and it stimulates angiogenesis and increases vascular permeability. Increased expression of VEGF may be associated with advanced stage and poor prognosis in patients with non-small cell lung cancer (NSCLC).

METHODS

Using enzyme-linked immunosorbent assay, the levels of VEGF were determined in serum from 41 patients with untreated NSCLC (Stage: IIB, 3; IIIA, 6; IIIB, 17; IV, 15;

HISTOLOGY

squamous cell carcinoma, 18; adenocarcinoma. 14; undetermined, 9).

RESULTS

The median VEGF level was 312 pg/ml, ranging from 70 to 1440 pg/ml. Patients were divided into high VEGF (>312 pg/ml) and low VEGF (< or =312 pg/ml) groups using the median value as a cut-off. There were no significant associations between the serum VEGF levels and various clinicopathologic characteristics including age, gender, histologic type, stage and treatment. A significant positive correlation was found between serum VEGF levels and platelet counts (r=0.495; P=0.001). In addition, serum VEGF levels also correlated with leukocyte counts (r=0.478; P=0.002). In seven patients with measurement of follow-up serum VEGF levels at the end of treatment (chemotherapy and/or radiotherapy), the median serum VEGF level significantly decreased after the treatment (416 pg/ml; range, 96-812 pg/ml vs. 185 pg/ml; range, 49-487 pg/ml; P=0.028). However, the median platelet count (317,000/microl; range, 190,000-395,000/microl vs. 246,000/microl; range, 72,000-271,000/microl; P=0.028) and leukocyte count (10,000/microl; range, 8700-17,200/microl vs. 5100/microl; range, 3900-9500/microl; P=0.018) also decreased after the treatment. There was no statistically significant difference in the median survival of the patients between high VEGF group and low VEGF group (8 months vs. 9 months, P=0.647).

CONCLUSIONS

Although serum VEGF level was significantly associated with platelet and leukocyte counts in NSCLC patients, it did not correlate with tumor burden and prognosis of the patients.

Neuroprotective and neurotrophic effects of quinic acids from Aster scaber in PC12 cells

Aster scaber T. (Asteraceae) has been used to treat bruises, snakebite, headache, and dizziness in traditional Chinese medicine. In the present study, the neuroprotective effect of four quinic acid derivatives from A. scaber on amyloid Abeta-induced PC12 cell toxicity was investigated. When cells were treated with quinic acid derivatives prior to Abeta, cell toxicity was significantly diminished. Among quinic acid derivatives, (-)4,5-dicaffeoyl quinic acid (1) gave the highest protection against Abeta-induced cell toxicity. In addition, the neurotrophic effects of compounds were evaluated by microscopically monitoring their potency to induce neurite outgrowth in PC12 cells. Four quinic acid derivatives from A. scaber promoted neurite outgrowth in PC12 cells. Interestingly, a novel quinic acid, (-)3,5-dicaffeoyl-muco-quinic acid (2) was more effective than the other compounds in promoting neurite outgrowth. Unlike nerve growth factor, the withdrawal of quinic acids did not result in any significant decrease in cell viability. The results suggest that quinic acid derivatives from A. scaber might potentially be used as a therapeutic agent in Alzheimer disease.

Carbetapentane attenuates kainate-induced seizures via sigma-1 receptor modulation

We examined the effects of a non-opioid antitussive, carbetapentane (CB) on kainic acid (KA)-induced neurotoxicity in rats. KA administration (10 mg/kg, i.p.) produced robust behavioral convulsions lasting 4 to 5 h. CB (12.5 and 25 mg/kg. i.p.) pretreatment consistently and in a dose-dependent manner reduced the KA-induced seizures, mortality, and marked loss of cells in regions CA1 and CA3 of the hippocampus. Consistently, CB pretreatment also significantly attenuated the KA-induced increase in Fos-related antigen immunoreactivity in the hippocampus. In contrast, pretreatment with the sigma-1 receptor antagonist BD1047 (1 and 2 mg/kg, i.p.) blocked, in a dose-related manner, the neuroprotection afforded by CB. These results suggest that CB provides neuroprotection against KA insult via sigma-1 receptor modulation.

Anticonvulsant effects of new morphinan derivatives

We synthesized a series of compounds that are modified in positions 3 and 17 of the morphinan ring system, with the intention of developing ideal anticonvulsant agents. We examined the effects of these compounds on kainic acid (KA)-induced seizures, and on locomotor patterns in rats. We found that compounds 5, 6, and 8 exhibit novel anticonvulsant effects, with negligible psychotropic effects.

Crystallization and preliminary X-ray analysis of human transglutaminase 3 from zymogen to active form

Transglutaminases(TGases; protein-glutamine-glutamyl-transferases) are a large family of calcium-dependent acyl-transfer enzymes that catalyze the formation of covalent cross links in proteins. Of these, the "epidermal" or "hair follicle" TGase 3 isoform is critically involved in barrier formation in epithelia. It is a zymogen, requiring proteolytic activation to achieve maximal specific activity. In order to understand its structure and function, we have devised methods for the rapid large-scale expression of the TGase 3 zymogen in the baculovirus system, and here we describe the purification of the zymogen and activated forms. We describe methods for the formation of high-quality, well-diffracting crystals within 3-5 days, using both dioxane and beta-octylglucoside to overcome severe twinning problems. The crystal of the zymogen belongs to the triclinic space group P1 and diffracts to 2.2-A resolution, and the crystal of the active form belongs to the P2(1) space group at 2.7-A resolution.

Reconstruction by biceps tendon rerouting for posterolateral rotatory instability of the knee: Modification of the Clancy technique

We present a biceps rerouting technique for posterolateral rotatory instability using a modification of the biceps femoris tendon tenodesis of Clancy. The distinguishing features of this technique are the approach to the lateral femoral epicondyle through the interval between the iliotibial band and biceps femoris muscle, and fixation of the transferred biceps tendon at the isometric point. Reconstruction for posterolateral rotatory instability by modified biceps tendon rerouting can result in objectively and functionally acceptable knee function.

Dextromethorphan affects cocaine-mediated behavioral pattern in parallel with a long-lasting Fos-related antigen-immunoreactivity

In order to understand the underlying mechanisms responsible for the behaviors mediated by dextromethorphan (DM), we examined the effects of DM on locomotor activity and locomotor patterns in mice, and Fos-related antigen immunoreactivity (FRA-IR) of mouse brain following repeated administration of cocaine. Combined treatments (30 min prior to each cocaine administration) with DM dose-dependently decreased locomotor activity for high doses of cocaine (20 mg/kg, i.p./day x 7). DM combinations did not significantly affect hyperactivity for 10 mg cocaine/kg, i.p./day x 7. In contrast, combined treatments with DM increased the locomotor activity for 5 mg cocaine/kg, i.p./day x 7. These results were consistent with alterations in marginal activity. Repeated administration with cocaine or DM increased FRA-IR in the nucleus accumbens (NAc) and striatum which lasted for at least 7 days. Our results suggest that DM exhibits biphasic effects on the locomotor stimulation induced by cocaine, and that locomotor activities are in parallel with FRA-IR of the striatal complex. However, the role of FRA-IR regulated by DM or/and cocaine remains to be further determined.

Automatic identification of human helminth eggs on microscopic fecal specimens using digital image processing and an artificial neural network

In order to automate routine fecal examination for parasitic diseases, we propose in this study a computer processing algorithm using digital image processing techniques and an artificial neural network (ANN) classifier. The morphometric characteristics of eggs of human parasites in fecal specimens were extracted from microscopic images through digital image processing. An ANN then identified the parasite species based on those characteristics. We selected four morphometric features based on three morphological characteristics representing shape, shell smoothness, and size. A total of 82 microscopic images containing seven common human helminth eggs were used. The first stage (ANN-1) of the proposed ANN classification system isolated eggs from confusing artifacts. The second stage (ANN-2) classified eggs by species. The performance of ANN was evaluated by the tenfold cross-validation method to obviate the dependency on the selection of training samples. Cross-validation results showed 86.1% average correct classification ratio for ANN-1 and 90.3% for ANN-2 with small variances of 46.0 and 39.0, respectively. The algorithm developed will be an essential part of a completely automated fecal examination system.

Effects of dextromethorphan on the seizures induced by kainate and the calcium channel agonist BAY k-8644: comparison with the effects of dextrorphan

BAY k-8644 (an L-type Ca(2+) channel agonist of the dihydropyridine class) is recognized as a potent convulsant agent. In this study, we used BAY k-8644 to explore the effects of dextromethorphan (DM) and its major metabolite, dextrorphan (DX), on the (pro)convulsant activity regulated by calcium channels. BAY k-8644 (2 mg/kg, s.c) potentiated seizures induced in rats by kainic acid (KA) (10 mg/kg, i.p.). DM appears more efficacious than DX in attenuation of KA-induced seizures. The anticonvulsant effect of a low dose (12.5 mg/kg, s.c.) of DM was reversed by BAY k-8644 (2 mg/kg) challenge. In contrast, BAY k-8644 (1 or 2 mg/kg) did not significantly affect an anticonvulsant effect from a higher dose (25 mg/kg) of either DM or DX. Intracerebroventricular injection of BAY k-8644 (37.5 microg) significantly induced seizures in mice. DM (12.5 or 25 mg/kg) pretreatment more significantly attenuated seizures evoked by BAY k-8644 than did DX (12.5 or 25 mg/kg). Furthermore, seizure activity induced by KA or BAY k-8644 was consistent with respective activator protein-1 DNA binding activity of the hippocampus. Therefore, our results suggest that the anticonvulsant effects of the morphinans involve, at least in part, the L-type calcium channel. They also suggest that DM is a more potent anticonvulsant than DX in the KA and BAY k-8644 seizure models.

Isolated bladder metastases from stomach cancer: CT demonstration

Isolated metastatic tumors of the urinary bladder are extremely rare. We report three cases of isolated bladder metastasis from stomach cancer, which were proved at transurethral biopsy or total cystectomy. The lesions appeared as focal or diffuse thickening of the bladder wall on computed tomography. No other metastatic lesion was detected on imaging studies, which made the diagnosis of bladder metastasis difficult. The possibility of metastatic bladder tumor should be considered when the bladder wall is thickened focally or diffusely in a patient treated with stomach cancer.

Cloning, expression, and complementation test of the RNA lariat debranching enzyme cDNA from mouse

The RNA lariat debranching enzyme of mouse (mDBR1) was cloned by screening a NIH/3T3 cDNA library. The sequence of full-length mDBR1 cDNA contained a single 515 amino acid open reading frame of 58 kDa protein. Comparison of the amino acid sequence of mDBR1 to other DBR proteins showed 40%, 44%, 43%, 42%, and 80% identity to Saccharomyces cerevisiae, Schizosaccharomyces pombe, Caenorhabditis elegans, Drosophila melanogaster, and human debranching enzymes, respectively. The mDBR1 cDNA was shown to be functional in an interspecies specific complementation experiment, and an in vitro debranching enzyme assay. Mouse DBR1 could complement the intron accumulation phenotype of a S. cerevisiae dbrl null mutant strain. However, the level of complementation depended on the copy number of the mDBR1 cDNA. The integration of the mDBR1 cDNA in the chromosome of S. pombe also complemented both intron accumulation and slow growth phenotypes of the S. pombe dbr1 knock-out mutant strain.

Clinical impacts of tumor cell contamination of hematopoietic stem cell products in metastatic breast cancer patients undergoing autologous peripheral blood stem cell transplantation: multicenter trial

To determine whether the tumor cell contamination of peripheral blood stem cells influences clinical impacts on high-dose chemotherapy in patients with metastatic breast cancer, we analyzed carcinoembryonic antigen (CEA) mRNA in the apheresis products by nested RT-PCR (reverse transcriptase-polymerase chain reaction). A total of 38 metastatic breast cancer patients and ten normal healthy subjects as a negative control were included. Twenty out of 38 (51.3%) apheresis products from patients with metastatic breast cancer were positive for CEA mRNA. CEA mRNA was noted in 54.8% (17/31) of patients mobilized with chemotherapy plus G-CSF and 42.8% (3/7) of patients with G-CSF alone. There was no significant difference in age, estrogen receptor, menopausal status, mobilization method, disease free interval, or number of metastasis sites (1 vs > or = 2) between positive and negative groups. The presence of CEA mRNA in apheresis products did not influence the time to progression and overall survival in both groups. However, both the univariate and the multivariate analysis disclosed that the number of metastasis was associated with survival significantly. We suggest that the tumor cell contamination does not predict poor treatment outcome in patients with metastatic breast cancer.

Mutations at the APC exon 15 in the colorectal neoplastic tissues of serial array

Although the APC protein is known to participate in cellular proliferation and apoptosis, APC mutations have been thought to play a major role in the early stage of colorectal tumorigenesis. The somatic APC mutation of exon 15 was assessed to determine its impact on various stages of colorectal tumorigenesis. The colorectal neoplastic tissues of serial array studied included sporadic adenomas (group 1, n = 36), adenomas (group 2, n = 33), and carcinomas (group 3, n = 32) in the synchronous adenoma and carcinoma as well as sporadic carcinomas (group 4, n = 36). Aberrant DNA was detected by protein truncation test and confirmed by direct sequencing. The mutation prevalence was 36.1% in group 1, 45.5% in group 2, 59.4% in group 3, and 41.7% in group 4 with no differences among the groups. Among the 18 patients with synchronous adenoma and carcinoma, 9 had mutation in their adenomas and 12 in their carcinomas. The mutation loci and patterns did not differ in adenomas and carcinomas. Mutations in the mutation cluster region (MCR) were much more frequent than in the preceding region of MCR, i.e., 85.7% vs. 14.3%. The mutation prevalence of villous adenomas appeared greater than that of tubular adenoma (3/21 vs. 3/4). Predominant pathogenic mutations at MCR suggest that the APC mutation is implicated in all stages of colorectal tumorigenesis.

Relation of apolipoprotein E polymorphism to clinically diagnosed Alzheimer's disease in the Korean population

The gene for human apolipoprotein E (APOE) is found on the long arm of chromosome 19 (19q13.2) and exists in three common allelic forms, epsilon2, epsilon3, and epsilon4. The APOE epsilon4 allele is overrepresented in Alzheimer's disease (AD) and is accepted as a genetic risk factor. Some studies reported a protective effect of the APOE epsilon2 allele for AD. However, there are some ethnic variations in the proportion of different APOE alleles and their relationship to AD. We examine the distribution of APOE alleles from 30 AD patients and 158 controls in Korea. The control subjects were all cognitively intact unrelated Koreans. The frequencies of APOE alleles in AD patients were 18.3% (epsilon2), 58.3% (epsilon3), and 23.3% (epsilon4). The corresponding frequencies in controls were 13.3% (epsilon2), 72.5% (epsilon3), and 14.2% (epsilon4). The frequency of the APOE epsilon2 allele in AD patients was not significantly different from that in controls. When statistical analysis was conducted after the exclusion of the APOE epsilon2 allele, the frequency of the APOE epsilon4 allele in AD patients was significantly higher than that in controls (P < 0.05). These results support that the APOE epsilon4 allele plays a role as a risk factor for AD in Koreans and suggest that the APOE epsilon2 allele may not play a protective role in the development of AD in Koreans.

Robotic arm enhancement to accommodate improved efficiency and decreased resource utilization in complex minimally invasive surgical procedures

Resource allocation, including manpower and other expenses, have limited the evolution of minimally invasive surgical procedures to provide humanism and to improve surgical care for patients. Robotic enhancement has been proposed as a mechanism to improve the cost-benefit relationship for patients. To this end, we have used the robotic arm enhancement to minimize resource and personnel utilization during minimally invasive procedures. Phase I of our study has included the use of the robotic arm in 24 laparoscopic hernia repairs, cholecystectomies, and nissen fundoplications with the surgeon as a solo surgeon, i.e., the primary surgeon is the only participant in the operative sterile field. The scrub nurse did not participate in the procedures. During this study, there were no technical mishaps, no complications related to the solo surgeon-robotic arm concept, and the operative times were statistically similar to equivalent procedures utilizing multiple personnel. The hernia repair is least complex and most amenable to solo surgery due to the use of only three access ports; cholecystectomy occasionally requires four access ports increasing its complexity to a measurable degree. Nissen fundoplication, however, requires five access ports and proved to be the most complex of the procedures to adapt successfully to solo surgery utilizing robotic arm enhancement. Phase II of our study has involved the use of a combination of technologically complex and sophisticated technology to improve outcomes in complex laparoscopic procedures. The head-mounted display, the robotic arm, and the harmonic scalpel have been used in 140 complex minimally invasive procedures; the procedures were laparoscopic spine surgery (24 cases), laparoscopic gastric surgery (28 cases), and laparoscopic colon resection (88 cases). The use of these sophisticated technologies added safety, improved versatility, and did not increase the length of the operative procedures. The use of multiple technologies had an additive effect on the benefits. There were no experiences in which the technologies contributed to a technical complication or an adverse result for the patients. However, the successful use of these technologies requires an in depth educational experience for the surgeon and for the operating room team. In a further effort to improve efficiency and control of the visual fields during minimally invasive surgery, we have implemented a prototype voice activation, head-directed control, and instrument tracking by robotic arm enhancement in order to control the visual field through computer programming. Prototype voice activation and deactivation also allows instruments to be used in the visual field for the surgical procedure while not being used for tracking of the visual field. Tracking with the instrument utilizing a color-coded tracking system, and the head-directed control system have both been 100% effective in our hands, have not induced errors in technical performance of procedures, and have shortened the time required for performance of specific procedural tasks. Further, this process improves versatility for the surgeon, increases concentration, reduces fatigue and does not interfere with the position of the surgeon. Areas for improvement which have been observed utilizing these techniques are (1) the use of appropriate and consistent voice activation terminology, (2) the proper positioning of the instrument tracking unit in the most appropriate locations on the video screen and on the instrument within the visual field, and (3) the appropriate use of head-directed control of the robotic arm. We have concluded from these experiences that the robotic technology will continue to reduce costs and minimize risk for patients undergoing minimally invasive surgical procedures; moreover, safety, versatility, and diminished use of resources will accrue utilizing the additive benefit of sequential sophisticated technologies requiring a simultaneous educational

Low serum cholesterol and haemorrhagic stroke in men: Korea Medical Insurance Corporation Study

BACKGROUND

In some prospective studies, haemorrhagic stroke occurs more frequently in individuals with low serum cholesterol than in those with higher concentrations. We aimed to determine whether low total serum cholesterol is an independent risk factor for haemorrhagic stroke (intracerebral haemorrhage and subarachnoid haemorrhage) in South Korea, a country that has a population with relatively low concentrations of total serum cholesterol.

METHODS

We measured total serum cholesterol and other cardiovascular risk factors in 114,793 Korean men, aged between 35-59 years in 1990 and 1992, in a prospective observational study. We used data obtained in 1992 for smoking and alcohol consumption. We divided total serum cholesterol into quintiles (<4.31 mmol/L, 4.31-<4.74, 4.74-<5.16, 5.16-<5.69 and > or = 5.69). Our primary outcomes were hospital admissions and deaths from intracerebral and subarachnoid haemorrhage in a 6 year follow-up between 1993 and 1998.

FINDINGS

528 men had a haemorrhagic stroke--372 intracerebral and 98 subarachnoid haemorrhage--and 58 were unspecified strokes. The relative risks of intracerebral haemorrhage in each quintile of total serum cholesterol (lowest to highest were: 1.22 (95% CI 0.88-1.69); 0.86 (0.60-1.21); 1.08 (0.78-1.48); and 1.03 (0.75-1.41). The corresponding relative risks for subarachnoid haemorrhage were: 1.44 (0.76-2.73); 1.13 (0.59-2.20); 1.21 (0.64-2.29); and 1.12 (0.59-2.14).

INTERPRETATION

Low total serum cholesterol is not an independent risk factor for either intracerebral or subarachnoid haemorrhagic stroke in Korean men.