Zhonghua Yi Xue Za Zhi (Taipei)
September 2001
Background: The acute physiology and chronic health evaluation (APACHE) scoring system has been validated in many different patient populations, however, patients with myocardial infarction (MI) were not included in the original data base. To evaluate the ability of APACHE scoring system in predicting in-hospital mortality, 694 patients with MI were studied.
Methods: Data had been collected prospectively in an ICU computer database in the past 3 years.
As part of an effort to develop a new class of subtype selective nicotine agonists, we have synthesized and tested a group of 12 hydroxylated 2-(2-piperidyl)- and 2-(2-pyrrolidyl)chromans. In rat brain membranes, all 12 compounds displayed poor affinity for [(125)I]-alpha-bunagarotoxin binding sites. In contrast, three compounds, 17c, 24, and 26, displayed moderate to high affinity for [(3)H]cytisine binding sites, while three (17b, 18b,c) and six (17a,d,e and 18a,d,e) compounds showed weak and poor affinity, respectively, for these same sites.
View Article and Find Full Text PDFIt is well known that overproduction and accumulation of beta-amyloid (Abeta) plaques in the brain is a key event in the pathogenesis of Alzheimer's disease (AD). Previously it was demonstrated that [125I]TZDM, 2-(4'-dimethylaminophenyl)-6-iodobenzothiazole, a thioflavin derivative, was an effective ligand with good in vitro and in vivo binding characteristics. To further improve the initial uptake and washout rate from the brain, important properties for in vivo imaging agents, a novel radioiodinated ligand, 2-(4'-dimethylaminophenyl)-6-iodobenzoxazole ([125I]IBOX, 3), for detecting Abeta plaques in the brain, was synthesized and evaluated.
View Article and Find Full Text PDFObjectives: To assess the quality of anaesthetic services as defined in the six anaesthetic clinical indicators against preset standards and to identify risk factors for adverse events in the recovery room.
Design: Prospective study.
Setting: All public hospitals providing anaesthetic care in Hong Kong.
Background And Purpose: This retrospective study compared the capability of the Acute Physiology and Chronic Health Evaluation (APACHE) II and APACHE III scoring systems to predict outcome and determined the independent predictors of survival in these scoring systems for patients with respiratory failure in a medical intensive care unit (ICU).
Materials And Methods: Seven hundred and eight patients with respiratory failure admitted to the medical ICU throughout a 9-year period were studied. Patients with an ICU stay of less than 24 hours, patients under 12 years of age, and burn and surgery patients were excluded.
A novel Congo red-derived fluorescent probe (trans, trans),-1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (BSB) that binds to amyloid plaques of postmortem Alzheimer's disease brains and in transgenic mouse brains in vivo was designed as a prototype imaging agent for Alzheimer's disease. In the current study, we used BSB to probe postmortem tissues from patients with various neurodegenerative diseases with diagnostic lesions characterized by fibrillar intra- or extracellular lesions and compared these results with standard histochemical dyes such as thioflavin S and immunohistochemical stains specific for the same lesions. These data show that BSB binds not only to extracellular amyloid beta protein, but also many intracellular lesions composed of abnormal tau and synuclein proteins and suggests that radioiodinated BSB derivatives or related ligands may be useful imaging agents to monitor diverse amyloids in vivo.
View Article and Find Full Text PDFIn developing probes for detecting beta-amyloid (Abeta) plaques in the brain of Alzheimer's disease (AD), we have synthesized 1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (5, BSB). Due to the presence of two double bonds, formation of four different isomers is possible. Four isomers, E,E-5, E,Z-5, Z,E-5, and Z,Z-5, were prepared.
View Article and Find Full Text PDFObjective: To describe gestational age-dependent and -independent nomograms for fetal thyroid size.
Methods: Two hundred fetuses were evaluated between 16 and 37 weeks' gestation in this cross-sectional study.
Results: Nomograms of fetal thyroid size were created by using the 5th, 10th, 50th, 90th, and 95th percentiles based on biparietal diameter and gestational age.
We report for the first time that small molecule-based radiodiodinated ligands, showing selective binding to Abeta aggregates, cross the intact blood-brain barrier by simple diffusion. Four novel ligands showing preferential labeling of amyloid aggregates of Abeta(1-40) and Abeta(1-42) peptides, commonly associated with plaques in the brain of people with Alzheimer's disease (AD), were developed. Two 125I-labeled styrylbenzenes, (E,E)-1-iodo-2,5-bis(3-hydroxycarbonyl-4-hydroxy)styrylbenzene, 12 (ISB), and (E,E)-1-iodo-2,5-bis(3-hydroxycarbonyl-4-methoxy)styrylbenzene, 13 (IMSB), and two 125I-labeled thioflavins, 2-[4'-(dimethylamino)phenyl]-6-iodobenzothiazole, 18a (TZDM), and 2-[4'-(4''-methylpiperazin-1-yl)phenyl]-6-iodobenzothiazole, 18b (TZPI), were prepared at a high specific activity (2200 Ci/mmol).
View Article and Find Full Text PDFThe regional distribution and cellular localization of dopamine D3 receptors in the rat brain was examined using quantitative autoradiography. [(125)I]7-OH-PIPAT bound in a saturable and reversible manner and exhibited subnanomolar affinity for a single population of GTP-insensitive sites. The pharmacological profile was characteristic of cloned D3 receptors and nonspecific binding was uniformly low.
View Article and Find Full Text PDFThe dopamine D2 receptor (D2) system has been implicated in several neurological and psychiatric disorders, such as schizophrenia and Parkinson's disease. There are two isoforms of the D2 receptor: the long form (D2L) and the short form (D2S). The two isoforms are generated by alternative splicing of the same gene and differ only by 29 amino acids in their protein structures.
View Article and Find Full Text PDFAn improved iodinated tracer, ADAM (2-((2-((dimethylamino)methyl)- phenyl)thio)-5-iodophenylamine) for imaging serotonin transporters (SERT) with single photon emission computerized tomography (SPECT), was prepared and characterized. Scatchard analysis of saturation binding of [(125)I]ADAM to rat frontal cortical membrane homogenates gave a K(d) value of 0.15 +/- 0.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
June 2000
Strategies for treating Alzheimer's disease (AD) include therapies designed to decrease senile plaque (SP) formation and/or promote clearance of SPs, but clinical trials of these treatments are limited by the lack of effective methods to monitor changes in plaque burden in the brains of living AD patients. However, because SPs are extracellular deposits of amyloid-beta peptides (Abeta), it may be possible to eventually develop radioligands that cross the blood-brain barrier (BBB) and label SPs so they can be visualized by current imaging methods. As a first step toward the generation of such a radioligand, we developed a probe, [(trans,trans)-1-bromo-2, 5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (BSB)], and we report here that BSB has the following properties essential for a probe that can detect SPs in vivo.
View Article and Find Full Text PDFSerotonin transporters (SERT) are target-sites for commonly used antidepressants, such as fluoxetine, paroxetine, sertraline, and so on. Imaging of these sites in the living human brain may provide an important tool to evaluate the mechanisms of action as well as to monitor the treatment of depressed patients. Synthesis and characterization of an improved SERT imaging agent, ADAM (2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine)(7) was achieved.
View Article and Find Full Text PDFThe serotonin transporters (SERT) are the primary binding sites for selective serotonin reuptake inhibitors, commonly used antidepressants such as fluoxetine, sertraline, and paroxetine. Imaging of SERT with positron emission tomography and single photon emission computed tomography in humans would provide a useful tool for understanding how alterations of this system are related to depressive illnesses and other psychiatric disorders. In this article the synthesis and characterization of [(125)I]ODAM [(5-iodo-2-(2-dimethylaminomethylphenoxy)-benzyl alcohol, 9)] as an imaging agent in the evaluation of central nervous system SERT are reported.
View Article and Find Full Text PDFNucl Med Biol
October 1999
Novel lipophilic and neutral glucose analogs, which are potentially useful for tumor imaging, have been developed. They are designed to circumvent Glut-facilitated transport mechanism, and direct the localization by either hexokinase binding or enzyme reactions (phosphorylation) as potential metabolic markers of tumor cells. Syntheses of tetraacetylated N-(3'-iodo-2'-propenyl)-1-deoxy-nojirimycin (11) and N-(3'-iodo-benzyl)-1-deoxy-nojirimycin (14) were achieved by reacting 1-deoxy-nojirimycin with appropriate alkylating agents.
View Article and Find Full Text PDF[99mTc]TRODAT-1 is a useful imaging agent in evaluating changes in presynaptic dopamine transporters (DAT) for Parkinson's disease and other central nervous system (CNS) neurodegenerative diseases, for which a reduction of dopamine neurons is indicated. As part of an effort to establish a quantitative single-photon emission tomography (SPECT) procedure for imaging CNS DAT, measurement of nonmetabolized [99mTc]TRODAT-1 in human plasma was investigated. After an intravenous injection of [99mTc]TRODAT-1, there are three possible radioactive components in human plasma: hydrophilic compounds (pertechnetate, etc.
View Article and Find Full Text PDFA new radioligand, 5-iodo-2-[[2-2-[(dimethylamino)methyl]phenyl]thio]benzyl alcohol ([(123)I]IDAM), has been developed for selective single-photon emission tomography (SPET) imaging of SERT. In vitro binding studies suggest a high selectivity of IDAM for SERT (K(i)=0.097 nM), with considerably lower affinities for norepinephrine and dopamine transporters (NET K(i)= 234 nM and DAT K(i)>10 microM, respectively).
View Article and Find Full Text PDFDevelopment of selective serotonin transporter (SERT) tracers for single-photon emission tomography (SPET) is important for studying the underlying pharmacology and interaction of specific serotonin reuptake site inhibitors, commonly used antidepressants, at the SERT sites in the human brain. In search of a new tracer for imaging SERT, IDAM (5-iodo-2-[[2-2-[(dimethylamino)methyl]phenyl]thio]benzyl alcohol) was developed. In vitro characterization of IDAM was carried out with binding studies in cell lines and rat tissue homogenates.
View Article and Find Full Text PDFMice deficient in monoamine oxidase A (MAO A) have elevated brain levels of 5-HT and manifest enhanced aggression. We used these mice as a model to study the role of 5-HT in aggression. Our results show that ketanserin and tetrabenazine (TBZ) strikingly abolished the aggressive behavior of MAO A-deficient mice.
View Article and Find Full Text PDFRecently, [Tc-99m]TRODAT-1, the first Tc-99m-labeled tracer for imaging CNS dopamine transporters in humans, was reported. This tracer displayed excellent specific binding to dopamine transporters in the basal ganglia region of the brain, thus it is potentially useful for the diagnosis of deficit of dopamine transporters in neurodegenerative diseases, such as Parkinson's disease. Preparation of [Tc-99m]TRODAT-1 was previously achieved by a multistep kit formulation.
View Article and Find Full Text PDFAccurate quantification of neuroreceptors requires full kinetic modeling of the dynamic single-photon emission tomography (SPET) or positron emission tomography (PET) images, with highly invasive arterial blood sampling. This study investigated the application of a reference region kinetic model to the dynamics of [99mTc]TRODAT-1 in nonhuman primates, obviating the need for blood sampling. A series of dynamic SPET scans were performed on two baboons following the injection of approximately 700 MBq of [99mTc]TRODAT-1.
View Article and Find Full Text PDFFour polymorphic sites (C/T188, C/T2938, G/C4268, G/A1934) in the cytochrome P4502D6 (debrisoquine 4-hydroxylase) gene were investigated for their association with sporadic Parkinson's disease (PD). Three mutant alleles (C/T188, C/T2938 and G/C4268) result in amino acid changes which could alter the substrate specificity or alter its ability to metabolize their substrates; the fourth (G/A1934) causes a loss of enzyme activity. The study was carried out in two ethnically homogenous populations: Chinese (123 PD patients, 124 controls); and Caucasian (95 PD patients, 62 controls).
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