Twenty-year follow-up of the Carpentier-Edwards standard porcine bioprosthesis in the Oriental population

AIM

The 20-year period long-term results of porcine bioprosthetic valve use are limited. In addition, the majority of these reports come from Western countries. Given the scanty information reported in Oriental countries, this study was therefore designed to examine 20-year long-term results in patients who received a Carpentier-Edwards porcine bioprosthetic valve in an effort to contribute further information on the long-term clinical performance of porcine prosthetic valves from a viewpoint of results in the Oriental population.

METHODS

From July 1979 to April 2001, 82 patients received valve replacement with a standard Carpentier-Edwards porcine valve. There were 40 men and 42 women with a mean age of 42.3+/-15.1 years (range 16 to 73 years). Follow-up time extended more than 20 years (mean 10.9+/-3.2 years, range 0.5 to 21.5 years ) for a total of 719.5 patient-years.

RESULTS

The overall operative mortality was 16.9% (14 of 83 procedures). At 5, 10, 15, and 20 years, the actuarial survival rate of patients was 71.7%, 66.9%, 55.5%, and 44.4%, respectively. Actuarial estimates of freedom from structural valvular deterioration (SVD) at 5, 10, 15, and 17 years were 96.3%, 64.0%, 24.3%, and 24.3%, respectively; from reoperation 96.3%, 64.5%, 24.5%, and 24.5%; from operated valvular endocarditis 96.8%, 92.6%, 92.6%, and 92.6%; and from overall thromboembolism 96.3%, 88.5%, 67.2%, and 52.2%. In normal sinus rhythm, actuarial estimates of freedom from thromboembolism at 5, 10, 15, and 17 years were 100.0%, 100.0%, 81.8%, and 81.8%, respectively. Whereas for those in patients with atrial fibrillation, the estimates of freedom from thromboembolism were 94.5%, 82.4%, 57.7%, and 38.5%.

CONCLUSION

This study demonstrates the very satisfactory 20-year period long-term performance of freedom from bleeding events, thromboembolism (except in patients with atrial fibrillation), and valvular endocarditis in Oriental patients undergoing replacement with a porcine valve. However, the remarkable rate of SVD and reoperation ensued at 6 years after bioprosthesis implanted which does not differ from the series reported from Western countries.

Application of semiological seizure classification to epileptic seizures in children

To better define seizure characteristics and to examine whether semiological seizure classification (SSC) can be appropriately applied to the seizures of infants and children, we studied 152 videotaped seizures recorded in 133 children. Seizure semiology was described on the basis of a series of behavioural, sensory, and motor phenomena according to SSC. Special emphasis was placed on whether one semiology can be representative of a patient's whole semiology sequence. If one semiology was able to represent the whole sequence, the seizure was classified according to SSC. Ninety of 152 seizures (59.2%) could be classified as a single seizure type by SSC. However, only 19 of 53 seizures (35.9%) consisting of two semiologies, three of 24 seizures (12.5%) consisting of three semiologies, and one of eight seizures (12.5%) consisting of four semiologies could be classified according to SSC. Although SSC is very efficient, it is more accurately a descriptive terminology for clinical ictal events than a classification system.

National survey on West syndrome in Korea

AIM

To investigate and analyze the current epidemiological and clinical data for West syndrome (WS) in Korea, including treatments and outcome.

METHODS

Prepared survey forms were sent to hospitals located all over Korea to collect data on cases of WS treated between January 1997 and June 2000. Data from 21 institutes were returned.

RESULTS

Data were collected for 358 children (219 boys and 139 girls) who were diagnosed and treated for WS. The incidences of WS were 112 cases in 1997, 104 cases in 1998, 108 cases in 1999, and 34 cases in the first half of 2000. Based on these figures, the presumed annual incidence of WS in Korea was derived to be one in 4000 live births, although there was a great inter-district variability. Regarding the etiology, 138 cases (38.5%) were cryptogenic. For the 220 symptomatic cases, hypoxic-ischemic encephalopathy (HIE) was the most common etiologic factor (50.8%), followed by central nervous system anomaly including malformation of cortical development (21.4%), and neurocutaneous syndrome (8.6%). Clinically flexor type spasms were most common (59.2%) and 199 cases (55.6%) revealed typical hypsarrhythmia, electroencephalographically. During 1997 and 1998, vigabatrin (VGB) was used most frequently for the treatment of WS, followed by valproic acid and adrenocorticotropic hormone (ACTH). In 1999 and 2000, the use of ACTH diminished and topiramate was used more frequently than ACTH. Spasms were controlled in 230 cases (64.2%) and evolution to other seizure types was observed in 44 cases (11.2%). Developmental and/or mental retardation were noticed in 270 cases (75.4%).

CONCLUSIONS

The yearly incidence of WS did not show significant change in Korea between 1997 and 2000. Among symptomatic WS, HIE was the most common cause. During the period of this study, VGB was the most popular therapeutic regimen possibly because of shortage of ACTH. Recently, topiramate has showed promising signs as a therapy for WS.

Methimazole as an antioxidant and immunomodulator in thyroid cells: mechanisms involving interferon-gamma signaling and H(2)O(2) scavenging

The antithyroid drug, methimazole (MMI) is used to treat patients with Graves' hyperthyroidism. The major action of MMI is to inhibit synthesis of thyroid hormone in the thyroid gland. However, MMI also has antioxidant and immunomodulatory effects on thyrocytes and/or immune cells. This study identifies novel antioxidant and immunomodulatory effects of MMI involving the interferon-gamma (IFN-gamma) signaling pathway in thyroid cells. MMI inhibits transcription of the intercellular adhesion molecule-1 (ICAM-1) gene by modulating the function of transcription factor STAT1 (signal transducer and activator of transcription 1), which binds to the IFN-gamma activated site of the ICAM-1 promoter. Furthermore, MMI rapidly eliminates H(2)O(2) produced by IFN-gamma treatment in thyroid cells and thus inhibits the H(2)O(2)-mediated phosphorylation of tyrosine 701 in STAT1. MMI also eliminates H(2)O(2) in vitro. MMI facilitates electron transfer from NADPH to H(2)O(2) using thioredoxin or glutathione, fulfilling a role similar to peroxiredoxin or glutathione peroxidase, respectively. MMI prevents the IFN-gamma and H(2)O(2)-mediated reversible inactivation of phosphatases. These effects inhibit full activation of the IFN-gamma-induced Janus kinase(JAK)/STAT signaling pathway in FRTL-5 thyroid cells. These results may in part explain the antioxidant and immunomodulatory effects of MMI in thyroid cells of Graves' disease patients.

Combination Chemotherapy with Mitomycin C, Vinorelbine, and Cisplatin (MVrP) in Patients with Advanced Non-Small Cell Lung Cancer

PURPOSE

A phase II study was conducted in patients with advanced non-small cell lung cancer (NSCLC) in order to evaluate the efficacy and toxicity of the combination chemotherapy regimen of mitomycin C, vinorelbine, and cisplatin (MVrP).

MATERIALS AND METHODS

Between June 1996 and December 2000, fifty-nine patients with unresectable stage IIIB to IV, pathologically documented NSCLC were enrolled in this study. One cycle consisted of mitomycin C 10 mg/m2 i.v. day 1, vinorelbine 30 mg/m2 i.v. days 1 & 15, and cisplatin 80 mg/m2 i.v day 1 and the next cycle consisted of vinorelbine 30 mg/m2 i.v. days 29 & 43, and cisplatin 80 mg/m2 i.v day 29. Each cycle was alternated and treatments were repeated every 8 weeks.

RESULTS

We were able to evaluate fifty-three of 59 patients. Objective responses were seen in 22 (41.5%) patients (CR 0%, PR 41.5%). The median duration of response was 13.7 weeks and the median time to progression was 17.7 weeks. The median overall survival was 45.6 weeks. There was a significantly longer survival seen in responders (p=0.041). The toxicities of this regimen were acceptable without treatment related toxic death.

CONCLUSION

This study suggests that a combination regimen of mitomycin C, vinorelbine, and cisplatin is relatively effective and well tolerated for the treatment of advanced NSCLC.

Expression of the REB transcriptional activator in rice grains improves the yield of recombinant proteins whose genes are controlled by a Reb-responsive promoter

The gene encoding the rice transcription factor, REB (rice endosperm bZIP) was cloned from a bacterial artificial chromosome library of rice. The cloned 6,227-bp-long Reb gene is composed of six exons and five introns and is flanked by a 1.2-kb 5' promoter and a 1.2-kb 3' terminator region. The function of the Reb gene was explored by a transient assay by using a rice immature endosperm system. The effector constructs containing the native gene or fusion genes linking Reb to the rice actin (Act) or globulin (Glb) gene promoters and the reporter gene construct Glb-beta-glucuronidase (GUS) were used in this study. When these effector constructs were cotransferred with the reporter uidA gene encoding GUS under the control of the Glb promoter into immature rice endosperm cells, the Glb promoter was activated. The transient GUS expression was 2.0 to 2.5-fold higher with the effector construct than without. When the upstream activation sequence containing the GCCACGT(A/C)AG motifs of the Glb promoter was deleted, the activation by REB was abolished. On the other hand, a gain-of-function experiment showed that inserting the upstream activation sequence into the glutelin-1 (Gt1) promoter made it responsive to activation by REB. When cotransformed with Reb gene, mature transgenic rice grains containing the human lysozyme gene driven by the Glb promoter produced 3.7-fold more lysozyme. Accumulation of recombinant lysozyme in mature seed ranged from 30.57 to 279.61 microg.mg(-1) total soluble protein in individual transformants from 30 independent transformation events. Thus, our results show that REB is not only a transcriptional activator, it can also be used to increase the expression of recombinant protein in transgenic rice grains.

Herpes simplex encephalitis: MRI findings in two cases confirmed by polymerase chain reaction assay

Herpes simplex virus (HSV) type I causes a fulminant necrotising meningoencephalitis distinguished from other encephalitides by its focal and often haemorrhagic nature. Specific antiviral therapy with acyclovir can significantly improve the prognosis. We present MRI findings of two cases of herpes simplex encephalitis (HSE) confirmed by PCR analysis, focusing on the serial changes after acyclovir therapy: gyral swelling, high signal intensity on T2-weighted images in the subfrontal region, temporal lobe and insula in the initial stage, then regional extension with enhancement and haemorrhage despite appropriate acyclovir therapy, and finally encephalomalacia and brain atrophy.

Hemifacial seizure of cerebellar ganglioglioma origin: seizure control by tumor resection

The cerebellum is known to have an inhibitory effect on seizures. Nevertheless, cerebellar dysplastic lesions can be epileptogenic. A 4-month-old infant had paroxysmal facial contractions; tachypnea and nystagmoid eyeball and tremulous movements were occasionally combined. These evolved to stereotypic clinical patterns and frequencies, which increased despite administration of antiepileptic drugs (AEDs). Magnetic resonance imaging (MRI) demonstrated a mass arising from the superior cerebellar peduncle, although video-scalp EEG monitoring revealed no abnormal findings. Positron emission tomography with [(18)F]fluorodeoxyglucose revealed focal hypermetabolism in the same area identified by MRI. A depth electrode implanted in the mass revealed focal spike-and-wave discharges. The lesion was partly removed; pathologic diagnosis was ganglioglioma. Because of incomplete seizure control and residual tumor visible on MRI, a second operation was performed. After complete excision of the tumor, the patient became seizure free without AEDs. This case confirms the presence of seizure originating from the cerebellum and emphasizes the need for the complete removal of an epileptogenic lesion.

Cyclophilin a binds to peroxiredoxins and activates its peroxidase activity

Six distinct peroxiredoxin (Prx) proteins (Prx I-VI) from distinct genes have been identified in mammalian tissues. Prxs are members of a group of peroxidases that have conserved reactive cysteine residue(s) in the active site(s). An immediate physiological electron donor for the peroxidase catalysis for five Prx proteins (Prx I-V) has been identified as thioredoxin (Trx), but that for Prx VI (1-Cys Prx) is still unclear. To identify an immediate electron donor and a binding protein for Prx VI, we performed a Prx VI protein overlay assay. A 20-kDa binding protein was identified by the Prx VI protein overlay assay with flow-through fractions from a High-Q column with rat lung crude extracts. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) and MS-Fit, we identified the 20-kDa Prx VI-binding protein as a cyclophilin A (CyP-A). The binding of recombinant human CyP-A (hCyP-A) to Prx VI was confirmed by using the hCyP-A protein overlay assay and Western immunoblot analysis with hCyP-A-specific antibodies. hCyP-A enhanced the antioxidant activity of Prx VI, as well as the other known mammalian Prx isotypes. hCyP-A supported antioxidant activity of Prx II and Prx VI both against thiol (dithiothreitol)-containing metal-catalyzed oxidation (MCO) systems and ascorbate-containing MCO systems. Prx II was reduced by hCyP-A without help from any other reductant, and the reduction was cyclosporin A-independent. These results strongly suggest that CyP-A not only binds to Prx proteins but also supports its peroxidase activity as an immediate electron donor. In addition, Cys(115) and Cys(161) of hCyP-A were found to be involved in the activation and the reduction of Prx.

Intractable epilepsy associated with brain tumors in children: surgical modality and outcome

OBJECTS

The aim of this study was to evaluate the role of surgical modality in children with brain tumors and intractable epilepsy.

METHODS

Twenty-three patients who were treated for brain tumors and intractable epilepsy between January 1985 and March 1998 were retrospectively reviewed. The most common tumors were dysembryoplastic neuroepithelial tumors (n=9), oligodendrogliomas (n=6), and gangliogliomas (n=5). Six patients exhibited cortical dysplasia. The mean duration of follow-up was 43.4 months (range 12 to 125 months). Seizure outcome was more favorable (Engel's classes I and II) in patients with a complete resection of tumor (14/14 vs 6/9 for incomplete resection; P<0.05). There was no significant difference in seizure outcome between lesionectomy (n=13) and epilepsy surgery (n=10). The likelihood of requiring postoperative antiepileptic drugs was not influenced by the extent of resection or type of surgery.

CONCLUSIONS

On the basis of this study, we conclude that the complete resection of these tumors can be an appropriate initial treatment for children with brain tumors who experience intractable epilepsy.

A rapid and successful treatment for airbag-related traumatic macular hole

A 28-year-old female was diagnosed as having an airbag-related traumatic macular hole in the right eye 9 days subsequent to a traffic accident. Four weeks after the trauma, the patient's visual acuity was deteriorating to 20/600. Following vitrectomy, membrane peeling, use of autologous serum and intraocular gas tamponade, the hole healed within 12 days, more rapidly than the expected interval for the treatment of a traumatic macular hole. The visual acuities at the 3-month and 1-year follow-up examinations were 20/50, much better than the conventional surgical treatment of idiopathic macular hole and comparable to previous reports of the treatment of traumatic macular hole. Vitrectomy procedure has been proved to be effective for the treatment of traumatic macular hole. Vitrectomy combined with membrane peeling, autologous serum and intraocular gas tamponade can heal the traumatic macular hole more rapidly than the conventional treatment with vitrectomy only.

Molecular characterization of Hmg2 gene encoding a 3-hydroxy-methylglutaryl-CoA reductase in rice

Three genes encoding 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR, EC1.1.1.34), which converts HMG-CoA into mevalonate in the early key step of the plant isoprenoid pathway, were isolated by RT-PCR and rice cDNA and genomic library screening. A genomic Southern blot analysis confirmed that HMGR genes are present in three copies in rice. Of the three, the HMGR 2 gene (Hmg2) obtained as a cDNA clone and its genomic clone had 4 exons and 3 introns, and encoded a 576 amino acid peptide containing an open reading frame of 1,728 bp with a calculated Mw. of 61,150. The structure of rice Hmg2 had common features, based on its nucleotide and deduced amino acid sequence homologies, with other plant HMGR genes published to date. Rice Hmg2 transcripts were constitutively detected in all parts of the rice plant, except in lamina and their levels were high particularly in the leaf part of the dark-grown seedlings and mature flowers. Our result showed that mRNA levels of rice Hmg2 were strongly induced in seedlings and influorescence in the early development stage. Rice Hmg2 possibly has a housekeeping role involved in the sterol biosynthesis, among the possible roles of plant HMGR genes that have been suggested in other plants [Weissenborn et al. (1995)].

Calcification comparison of polymers for vascular graft

Polytetrafluoroethylene (PTFE), polyurethane (PU) and silicone are widely known biocompatible polymers which are commonly used for vascular grafts. However, in vitro and in vivo calcifications of these polymers have been found to seriously compromise their quality as biomaterials. In consideration of this problem, the present study compared the calcification rate and extent of PTFE, PU and silicone. Using the in vitro flow-type method, PTFE, PU and silicone films were tested for 1, 4, 7, 10, 14 and 21 days. After 21 days of in vitro calcification test, the calcium levels on PTFE, PU and silicone were 35.89 +/- 5.01 microg/cm2, 23.73 +/- 0.68 microg/cm2 and 19.86 +/- 5.28 microg/cm2, respectively. The higher observed calcium level for PTFE may be due to the effect of the rough surface of PTFE in accumulating calcium ions on the polymer surface. From the 7th day of test, the [Ca]/[P] molar ratio started to decrease over time, and PTFE showed a faster calcification process. This decreasing [Ca]/[P] molar ratio demonstrated the typical calcification mechanism consisting of phosphorus ion accumulation following calcium ion accumulation. This study concluded that PU and silicone are less calcified than PTFE film, a finding in good agreement with previously published studies.

Correlation between increased airway responsiveness and severity of pulmonary edema

To determine whether the severity of the pulmonary edema in sheep models of cardiogenic and non-cardiogenic pulmonary edema correlate with concomitant alterations in airway responsiveness using three separate measures of pulmonary edema: post-mortem wet-to-dry lung weight ratio (W/D), chest radiograph (CXR) scores, and small airway wall area. Cardiogenic pulmonary edema was induced by increasing left atrial pressure (increase PLA) and non-cardiogenic pulmonary edema was induced by intravenous administration of Perilla ketone (PK). There was a significant negative correlation between changes in airway responsiveness and changes in CXR grade (r=-0.749, P<0.05), W/D (r=-0.662, P<0.05), airway wall areas (r=0.784, P<0.05) after increases in both PLA and PK. Chest radiograph score, W/D, and airway wall area correlated with each other (CXR score and W/D r=0.657, P<0.05; CXR score and airway wall area r=0.678, P<0.05; airway wall area and W/D r=0.704, P<0.05). We speculate that the increased airway responsiveness observed during pulmonary edema may result from the mechanical effects of edema formation within the airways.

Characterization of UV-irradiated dense/porous collagen membranes: morphology, enzymatic degradation, and mechanical properties

Collagen-based membranous materials of various shapes (gel, film, sponge) are known to be the most promising materials in terms of facilitating the regeneration of dermal defects. In this study, dense and porous collagen membranes were fabricated using air-drying and freeze-drying processes, respectively, and the effect of ultraviolet (UV) radiation on the degree of membrane crosslinking was evaluated by in vitro biodegradation and mechanical testing. A non-irradiated membrane group was used as the negative control and a glutaraldehyde (GA) treated group as the positive control. Scanning electron microscopy showed that, as the freezing temperature decreased to -196 degrees C, the resultant mean pore sizes also decreased; optimal pore size was obtained at a freezing temperature of -70 degrees C. In vitro biodegradation and mechanical testing demonstrated that GA treatment or 4 hours of exposure to UV radiation significantly increased both resistance to collagenase and mechanical strength versus the untreated controls, regardless of the collagen membrane type (dense or porous). Our results suggest that UV treatment is a useful tool for the fabrication of collagen membranes designed to be used as dermal dressings.

MR diagnosis of cerebellar infarction due to vertebral artery dissection in children

Posterior circulation infarction is uncommon in children. We describe the clinical presentation and radiological findings in two children with cerebellar infarction resulting from dissection of the vertebral artery. We emphasize that vertebral artery injury should be considered in a child with acute symptoms and signs of ischaemia in the posterior circulation. MRI and MRA may be helpful in the diagnosis of cerebellar infarction and vertebral artery abnormality.

Behavior of osteoblasts on a type I atelocollagen grafted ozone oxidized poly L-lactic acid membrane

With oxidizing poly-L-lactic acid (PLLA) surface by ozone, peroxide groups are easily generated on the surface. Those peroxides are broken down by redox-coupling reaction, and provide active species that initiate grafting by reaction with the collagen molecules. The surface density of generated peroxide on a PLLA surface was determined by an iodide method. The maximum concentration of peroxide was about 2.87 x 10(-8) mol/cm2 when ozone oxidation was performed at 60 V for 60 min. After the surface oxidation, type I atelocollagen was grafted onto PLLA surface. All physical measurements on the collagen-grafted surface indicated that the PLLA surface was effectively grafted with type I atelocollagen. Behavior of rat calvaria osteoblasts on type I atelocollagen grafted PLLA (PLLA + COL) surface was observed. Initial attachment of osteoblasts on the surface was significantly enhanced, and it is assumed that the atelocollagen matrix supported the initial attachment and growth of cells. Collagenous protein synthesis of osteoblasts was maintained at relatively low level in the early stage of proliferation due to the primarily existing grafted type I atelocollagen, and then increased in 7 days as the osteoblast differentiated. After 7 days, collagenous protein synthesis in osteoblasts was activated. Alkaline phosphatase (ALPase) activity and mineralization by osteoblasts were promoted on PLLA + COL surface. In comparison with PLLA + COL, non-treated PLLA and tissue culture plate (TCPS) did not show any feature expressed in osteoblasts' maturation up to 9 days in this experiment. The grafted type I atelocollagen provided a favorable matrix for cell migration in relation with collagenase expression. Ozone oxidation might be a favorable method for surface modification of PLLA membranes by collagen grafting, and cell behavior could be modulated by the grafted collagen.

Type I atelocollagen grafting onto ozone-treated polyurethane films: cell attachment, proliferation, and collagen synthesis

An approach is presented for the graft copolymerization of type I atelocollagen onto the surface of polyurethane (PU) films treated with ozone. Through inducing oxidization to modify PU surface by ozone, peroxide groups are easily generated on the surface. Those peroxides are broken by redox-polymerization, and provide active species which initiate graft polymerization by reacting with amines in the collagen molecules. The ozone oxidation time and voltage could readily control the amount of peroxide production. The surface density of generated peroxides on PU surface was determined by iodide method. The maximum concentration of peroxide was about 10.20 x 10(-8)mol/cm(2) when ozone oxidation was performed at 60 V for 30 min. After the reaction of PU by ozone oxidation, type I atelocollagen was graft-copolymerized onto the PU film. All the physical measurements on the collagen-grafted surface indicated that the PU surface was effectively covered with type I atelocollagen. The interaction of the collagen-grafted PU surface with fibroblasts could be greatly enhanced by the surface graft polymerization with type I atelocollagen. Attachment and proliferation of fibroblasts on the grafted type I atelocollagen were significantly enhanced, and it is assumed that the atelocollagen matrix supported the initial attachment and growth of cells. In the early stage of proliferation, collagen synthesis in fibroblasts was not activated and remained at a relatively low level due to the grafted type I atelocollagen, increasing only with fibroblast differentiation.

Viability evaluation of engineered tissues

Biohybrid artificial organs encompass all devices capable of substituting for an organ or tissue function and are fabricated from both synthetic materials and living cells. The viability of engineered tissue could be related to the viability of implanted cells. The system of viability assay for mammalian cell culture can be applied to the determination of cell viability for engineered tissue. This review explores various methods of cell viability assay which can be applied to the viability evaluation of engineered tissue. The major criteria employed in viability assays include survival and growth in tissue culture, functional assay, metabolite incorporation, structural altercation, and membrane integrity. Each viability assay method is based on different definitions of cell viability, and has inherent advantages and disadvantages. In order to be able to assess the viability of cells with one assay method, it is desirable to compare the viability measurements from various assays derived from different criteria.

Discrete subaortic membranous stenosis--a case report

Isolated subaortic stenosis is a rare type of cardiac anomaly which has been characterized as having two types: the discrete type, including membranous or fibromuscular, and the tunnel type. In the discrete type, a crescent-shaped, fibrous curtain is attached to the ventricular septum or completely encircles the left ventricular outflow tract and can be located anywhere from immediately below the aortic valve to 10 mm or more into the body of ventricle. A 22-year-old female presented at our hospital with a divided PDA, a murmur that was found by incident and progressive exertional dyspnea. Echocardiography revealed left ventricular hypertrophy, moderate aortic insufficiency, and severe aortic stenosis characterized by a thickened aortic valve and membranous type subaortic stenosis with a transmembranous high pressure gradient, 121 mmHg. An operation to replace the aortic valve and excise the membranous collar was performed with cardiopulmonary bypass support. The patient did well during the postoperative follow-up period. If the preoperative LVOT pressure gradient had been higher than 45 mmHg, the incidence of recurrent stenosis, progression of aortic regurgitation and the need for reoperation would have been higher. In order to prevent this from happening, we chose to replace the defective valve with a mechanical valve and enucleate the discrete lesion.

Molecular cloning and expression analysis of 3-ketoacyl-ACP synthases in the immature seeds of Perilla frutescens

We report the isolation and expression analysis of two cDNAs encoding 3-ketoacyl-acyl carrier protein synthases (KAS) that are involved in the de novo synthesis of fatty acids in plastids of perilla (Perilla frutescens L.). The cDNAs, designated PfFAB1 and PfFAB24, encoded polypeptides with high sequence identities to those of KAS I and KAS II/IV, respectively, of various plants. Genomic Southern blots revealed that there was a single PfFAB1 gene but two PfFAB24 genes in the perilla genome. Of interest is that the expression of both genes was developmentally regulated in seeds. Their mRNA expression patterns in seeds were also discussed in comparison with the profile of fatty acid accumulation.

Molecular cloning and functional expression of Perilla frutescens 3-ketoacyl-(acyl carrier protein) synthase III

The 3-ketoacyl-acyl carrier protein synthase III (KAS III) is a condensing enzyme catalyzing the initial step of fatty acid biosynthesis. We isolated two KAS III cDNA isoforms (PfKAS3a and PfKAS3b) from a cDNA library specific to Perilla frutescens immature seeds. Two cDNAs coded for 401 and 400 amino acids, respectively, which showed high degree of sequence similarity to corresponding enzymes from various sources. Results of Southern hybridization indicated that the PfKAS3a gene is present as two copies, whereas the PJKAS3b gene is a single copy. While both genes were equally expressed in high levels during early stages of seed maturation in a development-specific manner, the PfKAS3b transcript showed more prolonged appearance. Expression of the functional recombinant perilla KAS III increased the myristate level in E. coli but it exerted no appreciable effect on cell growth.

Analysis of expressed sequence tags from Brassica rapa L. ssp. pekinensis

Non-redundant expressed sequence tags (ESTs) were generated from six different organs at various developmental stages of Chinese cabbage, Brassica rapa L. ssp. pekinensis. Of the 1,295 ESTs, 915 (71%) showed significantly high homology in nucleotide or deduced amino acid sequences with other sequences deposited in databases, while 380 did not show similarity to any sequences. Briefly, 598 ESTs matched with proteins of identified biological function, 177 with hypothetical proteins or non-annotated Arabidopsis genome sequences, and 140 with other ESTs. About 82% of the top-scored matching sequences were from Arabidopsis or Brassica, but overall 558 (43%) ESTs matched with Arabidopsis ESTs at the nucleotide sequence level. This observation strongly supports the idea that gene-expression profiles of Chinese cabbage differ from that of Arabidopsis, despite their genome structures being similar to each other. Moreover, sequence analyses of 21 Brassica ESTs revealed that their primary structure is different from those of corresponding annotated sequences of Arabidopsis genes. Our data suggest that direct prediction of Brassica gene expression pattern based on the information from Arabidopsis genome research has some limitations. Thus, information obtained from the Brassica EST study is useful not only for understanding of unique developmental processes of the plant, but also for the study of Arabidopsis genome structure.

Calcification of leaflets from porcine aortic valves crosslinked by ultraviolet irradiation

Glutaraldehyde (GA)-pretreated porcine aortic valves are generally used as a bioprosthetic valve, but gradual calcification of the leaflets often occurs. It has been hypothesized that the crosslinking agent, GA, stabilizes and perhaps modifies phosphorus-rich calcifiable structures in the bioprosthetic tissue. This is supported by our findings that calcium deposition is induced rapidly in GA-pretreated leaflets in comparison with ultraviolet (UV) irradiated leaflets. After 3 days of in vitro calcification test, calcium levels were 257.6 +/- 23.5 microg/cm3 in GA-pretreated, 57.7 +/- 10.2 microg/cm3 in the control, and 108.6 +/- 7.6 microg/cm3 in 24 h UV irradiated leaflets. The calcium level in all test groups increased as time proceeds and the calcium level of GA-pretreated leaflets was significantly higher than the control and UV irradiated leaflets during test. This rapid calcium deposition on the GA-pretreated leaflets may be due to residual aldehyde groups after pretreatment. The exposure time of UV irradiation was not significantly correlated with the extent of calcification. After 14 days of the test, calcium levels in leaflets UV irradiated for 1, 2, 4, and 24 h were 502.6 +/- 12.3 microg/cm3, 547.5 +/- 34.1 microg/cm3, 564.3 +/- 26.1 microg/cm3, and 543.0 +/- 55.5 microg/cm3. In all test groups, [Ca]/[P] molar ratio decreased toward that of hydroxyapatite as the predominant mineral phase as time proceeds. This study suggests that UV irradiation can be considerable as an efficient crosslinking method to surmount the side effects induced by GA-pretreatment and may endow tissue with mechanical property.

Pediatric intractable epilepsy: the role of presurgical evaluation and seizure outcome

Surgical experience with long-term follow-up is limited in childhood intractable epilepsy, compared with adult epilepsy. To assess the role of each presurgical evaluation modality and to identify prognostic factors for favorable seizure control after epilepsy surgery, 38 children with intractable epilepsy who underwent surgery were retrospectively reviewed. Among the available preoperative evaluation modalities, PET and neuropsychological testing showed the highest rates of positive results, whereas MRI was the most concordant with EEG findings. During a follow-up period of at least 12 months, 26 of the 38 patients showed favorable seizure control (Engel classifications I and II). The best seizure control was achieved in patients with a temporal resection and discrete lesion on magnetic resonance imaging. In spite of the invasive study, the less satisfactory results followed an extratemporal resection. We conclude that epilepsy surgery benefits children with intractable epilepsy and that the role of invasive study should be reestablished according to the area of resection and presence of discrete lesion on MRI.

Dysembryoplastic neuroepithelial tumor: radiological findings (including PET, SPECT, and MRS) and surgical strategy

In order to elucidate the radiological features of dysembryoplastic neuroepithelial tumor (DNT), and to clarify the optimal surgical strategy for this tumor, the authors retrospectively analyzed 20 cases of DNT treated at our institution. Magnetic resonance (MR) imaging (all cases), 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) (eight cases), ictal/interictal Tc99m-HMPAO single photon emission computed tomography (SPECT) (seven and five cases respectively) and proton magnetic resonance spectroscopy (1H MRS) (one case) were performed preoperatively. Invasive monitoring/intraoperative electrocorticography (ECoG) was performed in four cases in order to determine the epileptogenic zone. A well-demarcated lobulating tumor located in the cortical with/without subcortical area was the typical MR finding. 18F-FDG PET showed glucose hypometabolism in all cases. Ictal Tc99m-HMPAO SPECT showed hyperperfusion of the lesion in three cases and interictal Tc99m-HMPAO SPECT showed hypoperfusion of the lesion in one case. 1H MRS showed nonspecific findings. Gross total resection was performed in all cases. Histologically, associated cortical dysplasia was found in 11 cases. The mean duration of follow-up after surgery was 37.9 months, and the overall seizure free rate was 90%. Follow-up MR imaging was performed in 14 cases (mean duration of follow-up: 21.6 months) and showed no recurrence of tumor in any of these cases. Invasive monitoring/intraoperative ECoG and the presence of cortical dysplasia showed no significant relationship with seizure control rate (p = 1.25 and p = 1.62 respectively).

Pre- versus post-anterior clinoidectomy measurements of the optic nerve, internal carotid artery, and opticocarotid triangle: a cadaveric morphometric study

OBJECTIVE

Published morphometric data supporting the microsurgical advantages of anterior clinoidectomy are scant. The goal of this study was to quantify, with direct measurements, the improved exposure of the optic nerve, internal carotid artery (ICA), and opticocarotid triangle (OCT) after extradural removal of the anterior clinoid process.

METHODS

Ten formalin-fixed adult cadaver heads were dissected bilaterally, and measurements were made both before and after anterior clinoidectomy. Twenty sets of pre- and post-anterior clinoidectomy measurements were collected, consisting of: 1) optic nerve length from the optic chiasm to the optic canal (pre) and to the anulus of Zinn (post); 2) ICA length from the ICA bifurcation to the distal limit of the anterior clinoid process (pre) and to the ICA distal dural ring (post); 3) OCT width, the widest in situ distance between the optic nerve and the ICA (pre) and the analogous measurement with allowable retraction on the mobilized ICA and optic nerve (post); and 4) OCT length from the point where the A1 segment crosses the optic chiasm to the optic canal (pre) and to the anulus of Zinn (post).

RESULTS

The right and left combined mean values +/- standard error of the mean before and after removal of the anterior clinoid process, respectively, were: optic nerve length, 10.28 +/- 2.30 mm and 22.83 +/- 2.54 mm; ICA length, 10.48 +/- 2.39 mm and 14.78 +/- 3.02 mm; OCT width, 3.93 +/- 1.16 mm and 12.95 +/- 2.61 mm; and OCT length, 10.38 +/- 2.84 mm and 23.55 +/- 2.79 mm.

CONCLUSION

Anterior clinoidectomy can provide a twofold increase in exposure of the optic nerve length and the OCT length, as well as a three- to fourfold increase in the maximum OCT width. This dramatically improves surgical exposure in the suprasellar and periclinoid regions.

A novel in vitro assessment of tissue valve calcification by a continuous flow type method

A dynamic flow type testing to study calcification was self-designed to investigate calcification in bioprosthetic heart valves. The apparatus consists of a container into which leaflets from a porcine aortic valve are placed, a chamber that contains calcium solution, and a peristaltic pump that provides a continuous supply of the solution toward the container. Efficacy of the apparatus was compared with the conventional batch type calcification testing at 37 degrees C through measuring the amount of calcium and phosphate deposited by inductively coupled plasma (ICP) and scanning electron microscope (SEM). After 14 days, calcium levels detected from the calcified deposit on leaflets were 470.4 +/- 37.0 microg/cm3 in the flow type testing whereas in the batch type testing levels were 81.0 +/- 6.7 microg/cm3. Though the calcium level on the leaflet increased as the exposure time to calcium solution increased in both testings, the rate and the tendency of calcification could be assessed very rapidly by flow type testing in comparison with batch type testing. [Ca]/[P] molar ratio decreased over time, and after 14 days, the ratio was close to 1.83 +/- 0.18 in the flow type testing. The ratio could not be determined in the batch type testing because the deposit was too small to assess. The descending rate of [Ca]/[P] molar ratio demonstrates that deposited calcium-complex at the earliest stage may interact with inorganic phosphate ions to create a calcified deposit mineral precursor. This in vitro dynamic flow type calcification testing was a favorable tool for rapid investigation of calcification.

Deletion of SMN and NAIP genes in Korean patients with spinal muscular atrophy

Childhood-onset proximal spinal muscular atrophies (SMAs) are an autosomal recessive, clinically heterogeneous group of neuronopathies characterized by selective degeneration of anterior horn cells. The causative genes to be reported are survival motor neuron (SMN) and neuronal apoptosis inhibitory protein (NAIP) genes. The deletion of telomeric copy of SMN (SMN(T)) gene was observed in over 95% of SMAs. The deletion rate of NAIP gene is 20-50% according to disease severity. The objective of this article is to genetically characterize the childhood-onset spinal muscular atrophy in Koreans. Five Korean families (14 constituents containing 5 probands) with SMA were included in this study. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used for the deletion analysis of SMN(T). Multiplex PCR method was used for NAIP analysis. Four probands showed deletion of SMNT gene. Deletion of SMN(C) (centromeric SMN) gene was found in one proband who did not show the deletion of SMN(T) gene and in the father of one proband who showed the deletion of SMN(T) gene. The deletion of NAIP gene was not found among all the studied individuals. The extent of deletion in Koreans was smaller than that in other studied population. PCR-RFLP deletion analysis can be applied to diagnose SMA and make a prenatal diagnosis.

Effect of pulmonary edema on tracheal diameter

BACKGROUND

Though it is well known that cardiogenic and noncardiogenic pulmonary edema can cause changes in lung mechanics, actual alterations in tracheal diameter have not been described.

OBJECTIVE

To evaluate the effects of pulmonary edema induced by increased left atrial pressure (cardiogenic) and Perilla ketone (PK; noncardiogenic) on tracheal diameter in chronically instrumented awake sheep.

METHODS

We investigated the effects of two mechanistically distinct types of pulmonary edema on tracheal diameter in chronically instrumented awake sheep. Cardiogenic pulmonary edema (analogous to congestive heart failure in humans) was induced by increasing left atrial pressure ( upward arrowP(LA)) by inflating the balloon on a Foley catheter positioned in the mitral valve annulus to cause partial obstruction to flow across the valve (n = 18). Noncardiogenic pulmonary edema (increased pulmonary microvascular permeability pulmonary edema analogous to the acute respiratory distress syndrome in humans) was produced by the intravenous administration of PK (n = 11). Lateral chest radiographs (CXRs) were scored by a standardized 5-point scoring system for the severity of pulmonary edema, and tracheal diameter was measured at a fixed location in the carina. Three radiologists, blinded to sheep identification number and experimental protocol, evaluated the radiographs independently at different points in time for edema severity and tracheal diameter. The sheep were sacrificed immediately after the final CXR, and wet/dry lung weight ratio (W/D ratio) was determined.

RESULTS

Both upward arrowP(LA) and PK were associated with statistically significant tracheal narrowing ( upward arrowP(LA): 20.3 +/- 0.6 to 15.1 +/- 0.9 mm; PK: 20.2 +/- 0.6 to 14.1 +/- 1.4 mm). Tracheal narrowing correlated with the severity of the pulmonary edema determined radiographically ( upward arrowP(LA): r = -0.69, p < 0.01; PK: r = -0.62, p < 0.01) and by W/D ratio ( upward arrowP(LA): r = -0.64, p < 0.05; PK: r = -0.54, p < 0. 05).

CONCLUSIONS

We conclude that tracheal narrowing occurs in sheep models of both cardiogenic and noncardiogenic pulmonary edema and that the degree of narrowing correlates with the severity of the edema.

Hereditary glomerulopathy associated with a mitochondrial tRNA(Leu) gene mutation

Several cases of hereditary glomerulopathy associated with an A to G transition at position 3243 in mitochondrial DNA, which is known to be associated with most cases of MELAS syndrome (myopathy, encephalopathy, lactic acidosis, and stroke-like episodes), have been recently reported. These patients share the characteristics of hereditary progressive glomerular disease and hearing loss with Alport syndrome. We therefore screened 27 patients with kidney disease clinically mimicking Alport syndrome for the presence of the 3243 mitochondrial mutation, and found one girl with the mutation and a positive family history. Her clinical features were very similar to those of all cases reported to date. An absence of hematuria, severe kidney involvement in a female, pathological changes of focal segmental glomerulosclerosis with no basket-weave change of the glomerular capillary wall, and the frequent association of steroid-induced diabetes are the major features that distinguish this condition from Alport syndrome. Careful neurological examination may detect neuromuscular symptoms compatible with mitochondrial cytopathies. In conclusion, progressive glomerulopathy should be included in the broad spectrum of mitochondrial cytopathies, especially in cases of MELAS syndrome. This mutation should also be included in the etiologies of secondary focal segmental glomerulosclerosis and in the differential diagnosis of Alport syndrome.

Differential expression of rice alpha-amylase genes during seedling development under anoxia

The unique capability of rice (Oryza sativa L.) seedlings to grow under anoxic conditions may result in part from their ability to express alpha-amylase and maintain the supply of sugar needed for energy metabolism. Previous studies have demonstrated that under aerobic conditions the Amy1 and Amy2 subfamily genes are regulated primarily by phytohormones while the Amy3 subfamily genes are induced during sugar starvation. The expression patterns for these alpha-amylase genes were considerably different in anoxic vs. aerobic rice seedlings. The level of total alpha-amylase mRNA under anoxic conditions was decreased in aleurone layers while it increased in the embryo. Anoxic conditions greatly diminished the expression of the Amy1A gene in aleurone. Conversely, expression of many Amy3 subfamily genes was up-regulated and prolonged in embryo tissues under anoxic conditions.

Opposite effects of FGF and BMP-4 on embryonic blood formation: roles of PV.1 and GATA-2

In adult vertebrates, fibroblast growth factor (FGF) synergizes with many hematopoietic cytokines to stimulate the proliferation of hematopoietic progenitors. In vertebrate development, the FGF signaling pathway is important in the formation of some derivatives of ventroposterior mesoderm. However, the function of FGF in the specification of the embryonic erythropoietic lineage has remained unclear. Here we address the role of FGF in the specification of the erythropoietic lineage in the Xenopus embryo. We report that ventral injection of embryonic FGF (eFGF) mRNA at as little as 10 pg at the four-cell stage suppresses ventral blood island (VBI) formation, whereas expression of the dominant negative form of the FGF receptor in the lateral mesoderm, where physiologically no blood tissue is formed, results in a dramatic expansion of the VBI. Similar results were observed in isolated ventral marginal zones and animal caps. Bone morphogenetic protein-4 (BMP-4) is known to induce erythropoiesis in the Xenopus embryo. Therefore, we examined how the BMP-4 and FGF signaling pathways might interact in the decision of ventral mesoderm to form blood. We observed that eFGF inhibits BMP-4-induced erythropoiesis by differentially regulating expression of the BMP-4 downstream effectors GATA-2 and PV.1. GATA-2, which stimulates erythropoiesis, is suppressed by FGF. PV.1, which we demonstrate to inhibit blood development, is enhanced by FGF. Additionally, PV.1 and GATA-2 negatively regulate transcription of each other. Thus, BMP-4 induces two transcription factors which have opposing effects on blood development. The FGF and BMP-4 signaling pathways interact to regulate the specification of the erythropoietic lineage.

Investigation of an outbreak of vancomycin-resistant Enterococcus faecium in a low prevalence university hospital

BACKGROUND

Until 1995, there were no cases of vancomycin resistant enterococcus (VRE) identified at our university hospital. From May 1995 to August 1996, we investigated a cluster of 10 cases of phenotypic class Van B Enterococcus faecium.

METHODS

Patients were matched with controls who were on the same unit for at least 7 days prior to the case developing VRE. Control patients were age and sex matched if possible, and had duration of hospitalization at least as long as the number of days it took the patient to become VRE positive. We analyzed 16 independent risk factors using Epi-info version 6. Environmental cultures were obtained in the MICU where 5 of the patients were located. All 10 patient isolates and environmental isolates were analyzed by pulsed field gel electrophoresis (PFGE).

RESULTS

PFGE confirmed the genetic relatedness of all 10 patient isolates and environmental isolates. The VRE-positive group was more likely to be immunosuppressed and to have exposure to 3 physicians. In the MICU, significant, P < 0.05) risk factors for VRE were higher Apache scores, location adjacent to a VRE case, duration of vancomycin and amino-glycoside use, duration of invasive catheter use, and diarrhea. Among the VRE-positive environmental cultures was a blood pressure cuff wash that was used on several patients.

CONCLUSION

We hypothesize that a VRE strain was introduced into our hospital environment and was spread by personnel or contaminated equipment. As a consequence of this study, a hospital-wide VRE policy was implemented.

Identification of polypeptides associated with an enriched cytoskeleton-protein body fraction from developing rice endosperm

Recent evidence has shown that the prolamine polysomes are attached not only to the endoplasmic reticulum membranes that bound the prolamine protein bodies (PBs) but also to cytoskeleton elements associated with this subcellular fraction. To learn more about the nature of the proteins that are associated with this supra-macromolecular complex, proteins extracted from an enriched cytoskeleton-PB fraction were resolved by two-dimensional polyacrylamide gel electrophoresis under non-equilibrium conditions and analyzed for their composition by immunological and biochemical methods. Immunoblot analysis indicated the presence of the cytoskeletal proteins, actin and tubulin, and the cytoskeletal-associated protein EF1 alpha in this fraction. Microsequencing of selected polypeptides revealed a diversity of protein sequences. In addition to contaminating storage proteins which are selectively solubilized by the isolation procedure, several ribosomal proteins and histone H3 were also identified. Some of the remaining polypeptides showed partial homology to protein sequences deposited in the database, several of which are cytoskeleton-associated proteins.

Effect of cardiogenic and noncardiogenic pulmonary edema on histamine responsiveness in sheep

We compared the effects of cardiogenic pulmonary edema, brief pulmonary vascular congestion without frank edema, and noncardiogenic pulmonary edema on responsiveness to inhaled histamine in chronically instrumented awake sheep. Histamine responsiveness was measured before and after 1) cardiogenic pulmonary edema induced by raising left atrial pressure to 35 cmH2O (Pla) for 3.5 h by partial obstruction of flow across the mitral valve, 2) brief cardiogenic congestion via Pla for 0.5 h, 3) noncardiogenic pulmonary edema induced by 25 mg/kg intravenous perilla ketone (PK), and 4) 3.5 h of monitoring without Pla or PK (controls). Treatment for 3.5 h with Pla (n = 9) and PK (n = 11) each significantly lessened the histamine dose required to cause a fall to 65% of baseline dynamic lung compliance (ED65Cdyn), i.e., increased responsiveness. Sheep treated for 0.5 h with Pla (n = 7) and controls (n = 5) showed no significant change in ED65Cdyn. Intravenous atropine (0.1 mg/kg) before the second histamine challenge altered neither the reduction of ED65Cdyn in Pla (n = 8) and PK (n = 9) sheep nor the ED65Cdyn level of controls (n = 9). These data imply that the local effects of edema, rather than bronchial vascular hemodynamics, cholinergic reflexes, and permeability changes, are germane to lung hyperresponsiveness during pulmonary edema in sheep.

Circadian rhythm of urinary endothelin-1 excretion in mild hypertensive patients

Endothelin-1 (ET-1) is a potent vasoconstrictive peptide with diverse physiologic actions and has been considered to be involved in the pathogenesis of hypertension. We sought to investigate the role of renal synthesis of ET-1 in the regulation of daily sodium homeostasis and the possible contribution of renal synthesized ET-1 in the pathogenesis of essential hypertension (EHT). Urinary ET-1-like immunoreactivity (ET-1-L1) was measured by a radioimmunoassay after extraction in 23 EHT patients without detectable target organ damage, and in 11 normotensive controls. All study subjects received a controlled diet during an 8-day study period. Urinary and blood samples were collected by four sampling periods/day from the 4th to 6th days, and on the 7th day, study subjects were given an intravenous infusion of 1250 mL normal saline over 2 h. In the basal state, the urinary sodium and ET-1-L1 excretions showed diurnal patterns in both the normal and hypertensive groups, and urinary ET-1-L1 excretion rate correlated well with urinary sodium excretion rate. There were no differences found in plasma ET-1 levels, urinary ET-1-L1, and sodium excretion rates between the control and hypertensive groups. After saline infusion, ten hypertensive patients showed nonexaggerated natriuresis, and the 24-h urinary ET-1-L1 excretion (47.0+/-4.0 pmol/day), collected during the day of saline infusion, was significantly lower than that of the control group (86.3+/-10.0 pmol/day) or the exaggeratedly natriuretic hypertensive patients (91.7+/-8.4 pmol/ day). Our results suggest that renal ET-1 may be responsible for the renal handling of sodium homeostasis, and alteration of renal ET-1 synthesis may be a contributory factor in the pathogenesis of essential hypertension and salt sensitivity.

Bubble fractionation of enantiomers from solution using molecularly imprinted polymers as collectors

Adsorptive bubble separation methods have been used to enrich components from both heterogeneous and homogeneous solutions. These methods are particularly effective for processing large solution volumes at low cost. Previous work demonstrated that chiral, surface-active collectors could be used to enrich enantiomers from homogeneous solution in a foam fractionation process. In a significant extension of this work, the use of highly selective molecularly imprinted polymers (MIPs) and heterogeneous solutions for the bubble flotation of enantiomers was evaluated. The high selectivity and ease of recycling of the MIP make this a potentially powerful approach for process-scale separations from large-volume bulk solutions. New MIPs were produced with low swelling properties which allowed them to retain enantioselectivity after numerous recyclings.

Overexpression and characterization of the cDNA encoding the coat protein of cucumber mosaic virus (Strain ABI) isolated in Korea

We constructed a recombinant CMVCP expression vector termed pMALCMV in which cDNA fragment encoding CMVCP is ligated into pMAL-c2, an E. coli expression vector. Overexpression of pMALCMV containing the entire open reading frame of CMV cDNA sequence and the maltose binding protein (MBP) leader gene was facilitated in E. coli TB1 cells, which resulted in the production of a fusion protein of MBP-CMVCP (Mr 67.7 kDa) that was immunoprecipitable with rabbit polyclonal antiserum specific for MBP. The CMVCP (Mr 24.5 kDa) was isolated through a preparative SDS polyacrylamide gel following digestion of the affinity ligand purified fusion protein with Factor Xa. The partial amino acid sequences of the cleaved proteins were confirmed at the amino terminus by peptide sequencing. The CMVCP antiserum was also prepared by intraperitoneal injection of this purified CP into a BALB/c mouse. Immunoblot analysis showed that the purified CMVCP from the Factor Xa cleavage reaction was an authentic overexpression product of the cloned CMVCP. Using an RNA mobility shift assay, it was demonstrated that CMVCP can bind to its own RNA transcript in a concentration dependent manner. However, the complex formed between CMVCP and its RNA was abolished by the addition of a polyclonal antibody that had been raised against CMVCP, confirming that the overexpressed CMVCP specifically interacts with its own RNA. Thus, our results can provide a basis for the development of a hybridoma cell line expressing the monoclonal antibody for CMVCP and molecular cloning of their genes, which may lead to the creation of CMV-resistant transgenic plants.

HLA haplotypes in Koreans based on 107 families

There are marked differences in the distribution of HLA haplotypes among different populations, and multilocus HLA haplotypes can best be studied by family analysis. In the present study, 107 Korean families were analyzed for HLA-A, B, C, DR, and DQ antigens and haplotypes. Allele frequencies of more than 10% for class I antigens were A2, A24, A33, B44, B62, Cwl, Cw7, Cw9, Cw10, and C blank (CBL) and those for class II antigens were DR4, DR8, DR13, DR15, DQ1, DQ3, DQ4 and DQ7. In the analysis of HLA haplotypes, 18 kinds of A-B-DR and 11 kinds of A-C-B-DR-DQ haplotypes occurred at frequencies of more than 1%, comprising 34% and 24% of the total theoretical haplotypes, respectively. The five most common A-B-DR haplotypes were exclusively related with the five most common A-C-B-DR-DQ haplotypes (frequency>2%). These remarkably conserved five-locus haplotypes in Koreans were A33-CBL-B44-DR13-DQ1 (5.4%), A24-Cw7-B7-DR1-DQ1 (3.5%), A33-Cw7-B44-DR7-DQ2 (3.0%), A33-Cw10-B58-DR13-DQ1 (2.3%), and A30-Cw6-B13-DR7-DQ2 (2.3%). Comparison of the distribution of A-B-DR haplotypes among East Asian populations revealed that Koreans are closest to Japanese, but show a higher degree of polymorphism in the distribution of HLA haplotypes compared to Japanese. The results obtained in this study will be useful as basic data on Koreans for anthropology and organ transplantation.

MR of hippocampal sclerosis: comparison of qualitative and quantitative assessments

PURPOSE

Our goal was to compare the diagnostic accuracy of subjective visual assessment versus MR volumetry in evaluating hippocampal sclerosis and to determine whether MR volumetry is needed in the lateralization of this disease process.

METHODS

MR imaging findings were studied retrospectively in 48 patients who underwent surgery for temporal lobe epilepsy and were compared with findings at MR volumetry on an Allegro workstation. Both visual assessment and volumetry were carried out in a blinded fashion with oblique coronal T1-weighted three-dimensional MP-RAGE images obtained on either 1.0-T or 1.5-T units. Normal right-left volumetric differences were recorded in 30 control subjects. The optimum cutoff threshold value for right-left volumetric differences in the sensitivity and specificity of volumetric measurement was obtained from receiver operating characteristic analysis.

RESULTS

Sensitivity, specificity, positive and negative predictive values, and accuracy of visual assessment were 86%, 83%, 86%, 83%, and 85%, respectively. For MR volumetry, with the optimum cutoff threshold value of right-left difference at 0.3 cm3, sensitivity, specificity, positive and negative predictive values, and accuracy were 81%, 82%, 87%, 83%, and 85%, respectively.

CONCLUSION

Visual assessment was slightly superior to or similar to MR volumetry in assessing unilateral hippocampal sclerosis. MR volumetry of the hippocampus may not be needed for the evaluation of most cases of suspected hippocampal sclerosis.

Three cis-elements required for rice alpha-amylase Amy3D expression during sugar starvation

Expression of alpha-amylase genes during seedling development plays a key role in production of sugar from the starch stored in the cereal seed. Rice alpha-amylase Amy3D promoter/GUS constructs in transgenic rice cell lines were studied to identify cis elements in the promoter of this metabolite-regulated gene. Three sequences having the greatest effects on Amy3D gene expression included the amylase element (TATCCAT), the CGACG element, and a G box-related element (CTACGTGGCCA). These promoter cis elements are needed for high-level expression of Amy3D under conditions of sugar starvation. The involvement of G box cis-elements in environmental stress responses suggest a link between the nutrient stress and the environmental stress responses of the plant.

Chemical suppression of gravitropic bending response in flower stalks of snapdragon (Antirrhinum majus L.)

Numbers of chemical agents which have been shown to inhibit either auxin signal transduction pathway or ethylene formation in plant cells were applied to cut flower stems of snapdragon (Antirrhinum majus L.) and their effects on the postharvest gravitropic response were studied. The chemical treatments were done by submerging either the stem base or the top part of cut flower, which involves the gravistimulus-sensitive region, for 1 h at 25 degrees C. When the chemicals were supplied from the cut stem base, the gravitropic upward bending of flower stalks kept horizontally after the treatments with 20 mM CDTA or 10 mM CoCl2 was comparable to that of the untreated control, but o-vanadate showed a certain degree of effectiveness for suppressing the bending response. In contrast, the direct application of those agents to the gravitropically sensitive region of cut flowers in the presence of 0.01% Triton X-100 resulted in a substantial reduction of the gravitropic response. In the case of 20 mM CoCl2 treatment, almost total elimination of gravitropism without any significant deterioration of flower quality was observed. The results indicate the possibility of preparation of a protocol involving CoCl2 and a proper surfactant for commercial use to suppress the gravitropic response of cut flowers during postharvest storage and transportation.

Molecular analysis of hypoxanthine guanine phosphoribosyltransferase (HPRT) gene in five Korean families with Lesch-Nyhan syndrome

Lesch-Nyhan syndrome is caused by the complete deficiency of hypoxanthine guanine phosphoribosyl-transferase (HPRT). By the analysis of genomic DNA and mRNA using the polymerase chain reaction (PCR) technique coupled with direct sequencing, five independent mutations in HPRT genes have been identified in Korean Lesch-Nyhan families. Two novel mutations and three previously reported mutations have been found in five independent families. Heterozygous carriers were detected in all the families, and prenatal diagnosis was carried out in two families.

Renovascular hypertension in children with moyamoya disease

OBJECTIVES

To examine the incidence, clinical and radiologic findings, and response to treatment of renovascular hypertension (RVHT) in moyamoya disease (MMD).

METHODS

A retrospective analysis of medical records in six RVHT cases (8.3%) among 72 MMD patients observed from November 1987 to December 1995.

RESULTS

The age at onset of MMD ranged from 9 months to 7 years 1 month (mean, 3.3 years). The most common initial manifestation of MMD was transient ischemic attack. Hypertension was detected between 4 years 4 months and 12 years 3 months (mean, 7.87 years). Unstimulated plasma renin activity was elevated in all six cases. Renal ultrasonography and captopril technetium 99m-labeled dimercaptosuccinic acid scan showed abnormal findings in four of five and in three of four available studies, respectively. However, both imaging studies showed abnormal findings only in the most severely affected kidneys even with bilateral renal artery stenosis. Renal arteriography revealed bilateral lesions in three of the patients and unilateral lesions in the others. Renal angioplasty was performed in four cases but was successful in only one and partially successful in another. A renal artery specimen obtained during renal autotransplantation showed intimal fibroplasia. At the last follow-up, one patient had normal blood pressure without the use of antihypertensive agents, but the other five patients needed this medication to control blood pressure.

CONCLUSION

Because RVHT may be more commonly associated with MMD than has hitherto been appreciated, it is recommended that blood pressure be carefully followed and that diagnostic procedures for RVHT be carried out in hypertensive patients with MMD.

MR of childhood metachromatic leukodystrophy

PURPOSE

To investigate the MR findings of childhood metachromatic leukodystrophy (MLD).

METHODS

Nine MR imaging studies in seven children (five girls and two boys, 10 to 32 months old) with MLD were evaluated retrospectively for the extent and progression of white matter abnormalities and the presence of contrast enhancement.

RESULTS

All seven cases showed symmetric, confluent high signal intensity on T2-weighted images in the periventricular white matter and centrum semiovale. A posterior predominance of white matter abnormalities was noted in all cases. Although initially spared from demyelination in all cases, in one case, the subcortical U fibers were later involved in demyelination of follow-up MR studies. Other sites of involvement were the genu (n = 5) and splenium (n = 6) of the corpus callosum, the posterior limbs of the internal capsule (n = 5), the descending pyramidal tracts (n = 4), the claustrum (n = 4), and the cerebral white matter (n = 2); diffuse brain atrophy was seen in two cases. No enhancement of the lesion was seen on any of the five postcontrast examinations. A "tigroid" pattern, previously described in cases of Pelizaeus-Merzbacher disease, was noted in the centrum semiovale in six cases.

CONCLUSION

In late-infantile MLD, demyelination is more prominent in the occipital region. In addition to demyelination of the periventricular white matter, common manifestations include a "tigroid" pattern and involvement of the corpus callosum, the internal capsule, and the corticospinal tract.

Cerebral sparganosis in a child

Cerebral sparganosis in childhood is very rare. Until 1996, 2 cases in children up to 15 years of age had been described. We report a case of cerebral sparganosis in a 6-year-old girl who presented with seizures. Sequential brain magnetic resonance imaging scans spaced over 4 months showed a lesion which migrated from the right parieto-occipital region to the right occipital region. The enzyme-linked immunosorbent assay for antisparganum antibody was positive. She most likely contracted sparganosis from worm-infested spring-water. A live worm with surrounding granulomatous tissue was removed, and the enzyme-linked immunosorbent assay for antisparganum antibody converted to negative 12 months following surgery. In areas of endemic sparganosis, the possibility of cerebral sparganosis should be considered, even in a child, if the patient shows a migrating granulomatous lesion.

Involvement of the gallbladder in childhood metachromatic leukodystrophy: ultrasonographic findings

The purpose of this study was to analyze the peculiar involvement of the gallbladder in childhood metachromatic leukodystrophy. Seven consecutive children (four boys, three girls; age range, 9 to 58 months old; mean age, 24.3 months) with biochemically confirmed metachromatic leukodystrophy were studied with abdominal ultrasonography. Four of them showed abnormal findings, such as diffuse thickening of the gallbladder wall (more than 3 mm thick), sludge-like echogenic material, or papillary polypoid ingrowth of inner wall obliterating the lumen. In childhood metachromatic leukodystrophy, the characteristic abnormality of the gallbladder on ultrasonography may serve as an ancillary diagnostic clue to supplement the clinical and MR imaging findings, facilitating the differential diagnosis from the other, similar leukodystrophies.

Detection of IgM antibody to Japanese encephalitis virus infection by enzyme-linked immunosorbent assay (ELISA)

BACKGROUND

Japanese encephalitis (JE) is an important infectious disease in Taiwan, with reported cases observed all the year around. Laboratory tests for JE consist mainly of hemagglutination inhibition (HI) test and neutralization test (NT). Commercialized enzyme-linked immunosorbent assay (ELISA) kits for detection of JE-IgM are still not available. Therefore an attempt has been made to develop a sensitive and rapid ELISA for detection of the IgM antibody to JE to serve as an indication of recent Japanese encephalitis virus infection.

METHODS

Both positive and negative JE serum specimens, confirmed by HI test, were checked for IgM antibody to JE by ELISA. The optimum concentration of biotin-IgG and avidin horse-radish peroxidase conjugate used in MAC-ELISA were 1/2000 and 1/ 15000, respectively.

RESULTS

From 1987 to 1989, 118 paired serum specimens of HI-confirmed JE patients were tested for JE-IgM by ELISA. The positive rate of JE-IgM was 65.7% (25/38), 73.9% (17/23), 93.5% (29/31) and 88.8% (8/9) for the consecutive first to fourth weeks after onset of the disease. The JE-IgM antibody of 17 serum specimens collected from the 5th to the 10th week after onset of the disease were 100% detected. In addition, among the 13 HI-confirmed JE cases occurring in 1994, 84.6% of the acute phase serum specimens demonstrated the JE-IgM antibody.

CONCLUSIONS

About 65.7% of the JE-IgM of the acute serum specimens collected within one week after onset of the disease were detected. The JE-IgM positive rate elevated as the days from disease onset increased. Therefore the appearance of JE-IgM could be used as an indication of recent JEV infection to serve as a rapid laboratory diagnostic tool.