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Smith A, O'Flanagan D, Igoe D, Cronin J, Forde D, McArdle E, Ko D. Outcome of medical screening of Kosovan refugees in Ireland: 1999. COMMUNICABLE DISEASE AND PUBLIC HEALTH 2000; 3:291-4. [PMID: 11280262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
In March 1999 armed conflict broke out in Kosova and about 900,000 ethnic Albanians were displaced. We reviewed the health care offered to the 945 Kosovan refugees who arrived in Ireland in 1999, which included screening for tuberculosis (TB) and hepatitis B. On arrival in Ireland 540 refugees had already received oral polio vaccine (57%), 512 diphtheria, tetanus, and acellular pertussis or diphtheria and tetanus vaccine (54%), 310 BCG (33%), 207 measles, mumps, and rubella vaccine (22%) and 60 Haemophilus influenzae type b (6%). Twelve refugees were diagnosed with TB. Twenty-six refugees were HBsAg positive (3%) and 168 were anti-HBcAg positive (18%). Organised screening of Kosovan refugees on a voluntary basis (uptake > 95%) revealed low percentages who had been immunised and relatively high rates of TB and hepatitis B. The provision of optimum immunisation, screening, and treatment services to address these issues requires substantial staffing and financial resources.
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Sung KP, Yang L, Kim J, Ko D, Stachnick G, Castaneda D, Nayar J, Broide DH. Eotaxin induces a sustained reduction in the functional adhesive state of very late antigen 4 for the connecting segment 1 region of fibronectin. J Allergy Clin Immunol 2000; 106:933-40. [PMID: 11080717 DOI: 10.1067/mai.2000.110797] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Eosinophils that have bound to extracellular matrix proteins, such as the connecting segment 1 (CS-1) region of fibronectin, need to deadhere before undergoing chemotaxis through the extracellular matrix. OBJECTIVE We have investigated whether eotaxin can regulate the strength of eosinophil adhesion to the CS-1 region of fibronectin. METHODS We have used a micropipette single-cell adhesion assay to determine the force of eosinophil adhesion to the CS-1 region of fibronectin. RESULTS Eosinophils bound to CS-1 with high avidity, and this binding could be inhibited with neutralizing antibodies to alpha4 integrins expressed by eosinophils or with neutralizing antibodies to CS-1. Eosinophils incubated in the presence of eotaxin demonstrated a transient increase in the force of eosinophil adhesion to CS-1, which was followed by a more sustained reduction in the force of eosinophil adhesion to CS-1, as assessed in the micropipette single-cell adhesion assay. This decreased binding of eosinophils to CS-1 was not due to alterations in very late antigen 4 (VLA-4) receptor number, as assessed with FACS analysis, or alterations in VLA-4 receptor distribution, as assessed with immunofluorescence microscopy. CONCLUSIONS These studies suggest that eotaxin can cause a transient increase followed by a more sustained reduction in the functional force of VLA-4 adhesion to CS-1 and thus promote deadhesion of CS-1 adherent eosinophils in the extracellular matrix.
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Mansourian-Hadavi N, Ko D, Mason T, Poeppelmeier K. Quadruple and Quintuple Perovskite-Layered Cuprates (NdDyBa2−xSrxCu2+yTi2−yO11−δ and NdDyCaBa2−xSrxCu2+yTi3−yO14−δ): Their Defect Chemistry and Electrical Properties. J SOLID STATE CHEM 2000. [DOI: 10.1006/jssc.2000.8936] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Greenwood KB, Ko D, Vander Griend DA, Sarjeant GM, Milgram JW, Garrity ES, DeLoach DI, Poeppelmeier KR, Salvador PA, Mason TO. Cation disorder in Ga1212. Inorg Chem 2000; 39:3386-91. [PMID: 11196879 DOI: 10.1021/ic0002667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Substitution of calcium for strontium in LnSr2-xCaxCu2GaO7 (Ln = La, Pr, Nd, Gd, Ho, Er, Tm, and Yb) materials at ambient pressure and 975 degrees C results in complete substitution of calcium for strontium in the lanthanum and praseodymium systems and partial substitution in the other lanthanide systems. The calcium saturation level depends on the size of the Ln cation, and in all cases, a decrease in the lattice parameters with calcium concentration was observed until a common, lower bound, average A-cation size is reached. Site occupancies from X-ray and neutron diffraction experiments for LnSr2-xCaxCu2GaO7 (x = 0 and x = 2) confirm that the A-cations distribute between the two blocking-layer sites and the active-layer site based on size. A quantitative link between cation distribution and relative site-specific cation enthalpy for calcium, strontium, and lanthanum within the gallate structure is derived. The cation distribution in other similar materials can potentially be modeled.
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Ko D, Heiman AS, Chen M, Lee HJ. New steroidal anti-inflammatory antedrugs: methyl 21-desoxy-21-chloro-11beta,17alpha-dihydroxy-3,20-dioxo-1, 4-pregnadiene-16alpha-carboxylate, methyl 21-desoxy-21-chloro-11beta-hydroxy-3,20-dioxo-1, 4-pregnadiene-16alpha-carboxylate, and their 9alpha-fluoro derivatives*. Steroids 2000; 65:210-8. [PMID: 10713309 DOI: 10.1016/s0039-128x(99)00103-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To a series of 21-desoxy-21-chloro-corticosteroids, a metabolically labile methoxycarbonyl group at C-16 has been incorporated. The approach is to synthesize locally active compounds that are hydrolyzed to inactive and readily excretable acid metabolites upon entry into the systemic circulation. Novel antedrugs were evaluated for anti-inflammatory activity and their adverse effects in an acute and semichronic croton oil-induced ear edema bioassay. Binding affinity to glucocorticoid receptors and induction of L-tyrosine-2-oxoglutarate aminotransferase were studied in hepatoma tissue culture cells. After a single topical application in the croton oil-induced ear edema bioassay, treatment with all the compounds resulted in dose-dependent inhibition of edema. From these dose-response profiles, the following ID(50) values (nmol/ear resulting in a 50% reduction of edema) were calculated: 540, 618, 454, and 346 nmol for prednisolone (P), methyl 21-desoxy-21-chloro-11beta,17alpha-dihydroxy-3,20-dioxo-1, 4-pregnadien-16alpha-carboxylate (PClCM), methyl 21-desoxy-21-chloro-11beta,17alpha-dihydroxy-9alpha-fl uoro-3, 20-dioxo-1,4-pregnadien-16alpha-carboxylate (FPClCM), and methyl 21-desoxy-21-chloro-9alpha-fluoro-11beta-hydroxy-3,20-dioxo- 1, 4-pregnadien-16alpha-carboxylate (FDPClCM), respectively. Results of the 5-day rat croton oil ear edema bioassay indicated that, in contrast with the parent compound P, the novel steroidal antedrugs did not significantly alter body weight gain, thymus weights, or plasma corticosterone levels. The binding affinities for cytosolic hepatoma tissue culture glucocorticoid receptors were 33, 201, 471, 5304, and 3765 nM for P, PClCM, FPClCM, methyl 21-desoxy-21-chloro-11beta-hydroxy-3,20-dioxo-1, 4-pregnadien-16alpha-carboxylate (DPClCM), and FDPClCM, respectively. Collectively, results of these investigations suggest that modifications of P, which included replacement of 21-hydroxyl group with chlorine and addition of 16-methoxycarbonyl group with or without 17-hydroxyl moiety, retained the topical anti-inflammatory activity of the parent compound P without significant adverse systemic effects.
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Waterhouse EJ, Garnett LK, Towne AR, Morton LD, Barnes T, Ko D, DeLorenzo RJ. Prospective population-based study of intermittent and continuous convulsive status epilepticus in Richmond, Virginia. Epilepsia 1999; 40:752-8. [PMID: 10368074 DOI: 10.1111/j.1528-1157.1999.tb00774.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE Previous work suggested that there is a lower mortality for convulsive status epilepticus (SE) with intermittent seizures (intermittent SE) as opposed to SE with continuous seizure activity (continuous SE). A plausible hypothesis to explain this difference is that the shorter ictal time in intermittent SE is responsible for the lower mortality in this group. This study investigates the relative contributions of total ictal time and SE duration to the differing mortalities of intermittent and continuous SE. METHODS Six hundred forty-five cases of prospectively identified convulsive SE were examined. Nonparametric statistical methods were used to compare continuous SE and intermittent SE variables. Multivariate logistic regression analyses were used to determine which factors were most highly associated with mortality. Intermittent SE cases were analyzed to evaluate the relative contributions of ictal time versus SE duration to mortality. RESULTS Intermittent SE had a significantly lower mortality than continuous SE (19.6 vs. 31.4%; p < 0.001) in adults but not in children. Intermittent and continuous SE durations did not significantly differ in adult cases but did differ in pediatric cases. Ictal time was significantly shorter than SE duration for intermittent SE in both adults and children. After adjusting for age, etiology, and SE duration, SE type (continuous SE vs. intermittent SE) was shown to have an independent effect on mortality in adults. The relative risk of mortality for continuous SE was 1.79 times that of intermittent SE (p = 0.04). After controlling for SE duration, ictal time did not significantly affect mortality in adults. CONCLUSIONS Intermittent and continuous convulsive SE were common in both pediatric and adult populations. Intermittent SE had a significantly lower mortality than did continuous SE. This difference in mortality was not completely explained by differences in SE duration, total ictal time, etiology, or age. Further research is needed to identify the factor(s) contributing to the significant difference in mortality between intermittent SE and continuous SE.
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Siegel H, Kelley K, Stertz B, Reeves-Tyer P, Flamini R, Malow B, Gaillard WD, Ko D, Theodore WH. The efficacy of felbamate as add-on therapy to valproic acid in the Lennox-Gastaut syndrome. Epilepsy Res 1999; 34:91-7. [PMID: 10210023 DOI: 10.1016/s0920-1211(98)00119-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We studied the efficacy of felbamate (FBM) in combination with valproic acid (VPA) in 13 patients with the Lennox-Gastaut syndrome and evaluated the contribution of each drug. Following stabilization on VPA monotherapy, FBM or placebo titration was performed for two observation periods lasting 7 weeks with a washout period between them. 6-h video-electroencephalography was recorded following each observation period. In addition to examining the effects of the drugs with parental reports and video-EEG, we compared video-EEG data with families' seizure reports. Based on parental counts for the 7-week observation periods, patients had 40% fewer drop attacks (p < 0.03, Wilcoxon rank sum test) and 60% fewer total seizures (p < 0.02) on VPA and FBM. VPA level rose by 12.7% when FBM was added (p < 0.01). When the effect of FBM was factored out, VPA had a significant effect on drop attack frequency, although not total number of seizures. FBM's therapeutic effect on drop attacks is due in part to increased VPA levels, although the combination may be synergistic for the effect on total seizure number.
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DeLorenzo RJ, Garnett LK, Towne AR, Waterhouse EJ, Boggs JG, Morton L, Choudhry MA, Barnes T, Ko D. Comparison of status epilepticus with prolonged seizure episodes lasting from 10 to 29 minutes. Epilepsia 1999; 40:164-9. [PMID: 9952262 DOI: 10.1111/j.1528-1157.1999.tb02070.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE Status epilepticus (SE) is a major medical and a neurologic emergency associated with significant morbidity and mortality. The current definition of SE is continuous seizure activity or intermittent seizure activity without regaining consciousness, lasting > or =30 min. Epilepsy monitoring unit data indicate that many seizures self-terminate within minutes. Thus consideration was recently given to include seizure episodes lasting > or =10 min in the definition of SE. Because no large studies have been conducted on seizures lasting 10-29 min, this study was initiated to compare cases of SE and 10 to 29-min seizure episodes seen within the same period. METHODS Patients seen at the Medical College of Virginia Hospitals of Virginia Commonwealth University over the same 2-year period were studied. Two hundred twenty-six prospective SE cases (91 children and 135 adults) and 81 retrospective 10- to 29-min seizure episodes (31 children and 50 adults) were compared. A standardized data-entry-form system was compiled on each patient and was used to evaluate the data collected. RESULTS The 10- to 29-min seizure patients and the SE cases had similar demographic characteristics, such as sex, race, and age, and also had similar etiologies. The majority (93%) of SE cases required anticonvulsant (AED) treatment to control and stop seizure activity. In the 10- to 29-min group, 43% stopped seizing spontaneously, and the remainder (57%) required AED treatment to stop seizure activity. The mortality for the SE patients was 19% compared with 2.6% for 10- to 29-min group (p<0.001). In the 10- to 29-min group that stopped seizing spontaneously, the mortality was 0. In the 10- to 29-min patients that required AED treatment, the mortality was 4.4%. CONCLUSIONS The results demonstrate that a significant number of patients experience seizure activity lasting from 10- to 29-min. Approximately half of these seizure events stopped spontaneously and did not require AED treatment. The other half of the patients responded quickly to medications and stopped seizing before the 30-min definition for SE. The overall mortality of this group was significantly lower than that of the patients with SE. The results demonstrate that further studies on the 10- to 29-min seizure group are needed to differentiate seizures that will stop spontaneously and those that will only stop with AED treatment. Because almost half of the prolonged seizures stopped spontaneously, further studies are needed before including prolonged seizure activity in the definition of SE.
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DeLorenzo RJ, Waterhouse EJ, Towne AR, Boggs JG, Ko D, DeLorenzo GA, Brown A, Garnett L. Persistent nonconvulsive status epilepticus after the control of convulsive status epilepticus. Epilepsia 1998; 39:833-40. [PMID: 9701373 DOI: 10.1111/j.1528-1157.1998.tb01177.x] [Citation(s) in RCA: 364] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE Convulsive status epilepticus (CSE) is a major medical and neurological emergency that is associated with significant morbidity and mortality. Despite this high morbidity and mortality, most acute care facilities in the United States cannot evaluate patients with EEG monitoring during or immediately after SE. The present study was initiated to determine whether control of CSE by standard treatment protocols was sufficient to terminate electrographic seizures. METHODS One hundred sixty-four prospective patients were evaluated at the Medical College of Virginia/VCU Status Epilepticus Program. Continuous EEG monitoring was performed for a minimum of 24 h after clinical control of CSE. SE and seizure types were defined as described previously. A standardized data form entry system was compiled for each patient and used to evaluate the data collected. RESULTS After CSE was controlled, continuous EEG monitoring demonstrated that 52% of the patients had no after-SE ictal discharges (ASIDS) and manifested EEG patterns of generalized slowing, attenuation, periodic lateralizing epileptiform discharges (PLEDS), focal slowing, and/or burst suppression. The remaining 48% demonstrated persistent electrographic seizures. More than 14% of the patients manifested nonconvulsive SE (NCSE) predominantly of the complex partial NCSE seizure (CPS) type (2). These patients were comatose and showed no overt clinical signs of convulsive activity. Clinical detection of NCSE in these patients would not have been possible with routine neurological evaluations without use of EEG monitoring. The clinical presentation, mortality, morbidity, and demographic information on this population are reported. CONCLUSIONS Our results demonstrate that EEG monitoring after treatment of CSE is essential to recognition of persistent electrographic seizures and NCSE unresponsive to routine therapeutic management of CSE. These findings also suggest that EEG monitoring immediately after control of CSE is an important diagnostic test to guide treatment plans and to evaluate prognosis in the management of SE.
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Vogel TU, Fournier J, Sherring A, Ko D, Parenteau M, Bogdanovic D, Mihowich J, Rud EW. Presence of circulating CTL induced by infection with wild-type or attenuated SIV and their correlation with protection from pathogenic SHIV challenge. J Med Primatol 1998; 27:65-72. [PMID: 9747945 DOI: 10.1111/j.1600-0684.1998.tb00228.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of this study was to evaluate the role of CTLs in the protection from challenge with pathogenic SHIV in macaques vaccinated with attenuated virus. More specifically, we have analyzed the CTL response in cynomolgus macaques vaccinated/infected with the attenuated SIVmacC8 or the wild-type SIVmacJ5 and correlated these responses to the protection from SHIV89.6P challenge. SIVmacC8-vaccinated monkeys demonstrated a broader CTL response than the SIVmacJ5-infected animals. Nevertheless, CTL against some proteins in SIVmacC8-vaccinated monkeys became progressively more difficult to detect through the day of challenge. In regards to protection from superinfection with SHIV89.6P, neither the presence of circulating CTL nor the CTL precursor frequency against any of the tested proteins correlated with the outcome of the challenge when SIVmacJ5- and SIVmacC8-infected animals were analyzed together. By analyzing the SIVmacC8-vaccinated animals separately, only the protected animal had detectable CTL precursors with moderate frequencies against all three tested proteins at the day of challenge.
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Chung M, Starling R, Buda T, Schweikert R, Ko D, Tchou P, Smedira N, Young J, McCarty P. Significant risk for ventricular arrhythmias remains after partial left ventriculectomy. J Am Coll Cardiol 1998. [DOI: 10.1016/s0735-1097(98)81917-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Secknus MA, Ko D, Marwick T. Prognostic value of dobutamine echocardiography is compromised in patients with atrial fibrillation despite adequate stress. J Am Coll Cardiol 1998. [DOI: 10.1016/s0735-1097(98)82116-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Jaitly R, Sgro JA, Towne AR, Ko D, DeLorenzo RJ. Prognostic value of EEG monitoring after status epilepticus: a prospective adult study. J Clin Neurophysiol 1997; 14:326-34. [PMID: 9337142 DOI: 10.1097/00004691-199707000-00005] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Despite the significant morbidity and mortality associated with status epilepticus (SE), little is known about changes in cortical function that occur after SE. We evaluated cortical function after clinical SE using continuous EEG monitoring lasting at least 24 h in 180 patients admitted to the Medical College of Virginia Hospitals (MCVH). The major EEG patterns observed after SE were a normal record, burst suppression, after SE ictal discharge (ASIDs), periodic lateralizing epileptiform discharges (PLEDs), attenuation, focal and generalized slowing, and epileptiform discharges. Normalization of the EEG after SE was highly correlated with good outcome. The presence of burst suppression and ASIDs was highly statistically significantly associated with mortality. PLEDs were also highly correlated with mortality, but not to the same degree as burst suppression and ASIDs. In addition, these EEG patterns were still significantly correlated with morbidity and mortality when we controlled for etiology using multivariate logistic statistical analysis. Persistent ictal activity was observed in many patients despite control of clinical seizure activity, indicating the importance of EEG monitoring to determine treatment patterns after clinical seizure activity in SE is controlled. The results indicate that certain EEG patterns (normalization of the EEG, ASIDs, burst suppression and PLEDs) are useful predictors of outcome in SE in addition to etiology. EEG monitoring after control of clinical SE is important to guide treatment of SE and is a useful technique for evaluating prognosis.
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Roth BJ, Ko D, von Albertini-Carletti IR, Scaffidi D, Sato S. Dipole localization in patients with epilepsy using the realistically shaped head model. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1997; 102:159-66. [PMID: 9129570 DOI: 10.1016/s0013-4694(96)95111-5] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Dipole sources were localized in 3 patients with epilepsy using both the realistically shaped head model and the 3-sphere model. Interictal spikes were recorded from 63 closely spaced scalp electrodes. The scalp, skull, and brain surfaces were digitized from a MRI of each patient's head, and each surface was tessellated by 1600 triangles. Single dipole fits to the EEG were performed using both the realistically shaped head model and the 3-sphere model. The 2 models localized dipoles to positions that differed from one another by 1-3 cm. For dipoles localized to the temporal lobe, the most important difference between models was that the realistically shaped head model localized the dipole lower in the brain than the 3-sphere model. The realistically shaped head model was more in accordance with the ECoG findings than the 3-sphere model.
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Ko D, Meyyappan A. Scanning tomographic acoustic microscopy using shear waves. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 1997; 44:425-430. [PMID: 18244140 DOI: 10.1109/58.585127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We propose to use shear waves instead of longitudinal waves in a novel scanning tomographic acoustic microscope (STAM) in which the specimens are solid. When a specimen with a shear modulus is immersed in the microscope's water bath, mode conversion takes place at the water-solid interface. The shear wave energy is detectable and can be used for image reconstruction. Although wave transmission in most solid specimens is limited to about 20 degrees for longitudinal waves, it is about twice that for shear waves. Also, velocities of shear waves are lower than those of longitudinal waves and hence the wavelengths at the same frequency are smaller. For these and other reasons we can expect that for many specimens the resolution of a shear-wave STAM to be substantially better than that of a longitudinal-wave STAM. We use computer simulation in order to compare the operation of a shear-wave STAM with that of the conventional longitudinal-wave STAM. We have simulated tomographic reconstruction for each. The corresponding critical angles of incidence are computed and tomographic reconstructions of a particular solid specimen is obtained by using the back-and-forth propagation algorithm (BFP). Our simulation results show that shear-wave STAM has better resolution than longitudinal-wave STAM.
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Ko D, Heck C, Grafton S, Apuzzo ML, Couldwell WT, Chen T, Day JD, Zelman V, Smith T, DeGiorgio CM. Vagus nerve stimulation activates central nervous system structures in epileptic patients during PET H2(15)O blood flow imaging. Neurosurgery 1996; 39:426-30; discussion 430-1. [PMID: 8832691 DOI: 10.1097/00006123-199608000-00061] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
OBJECTIVE To determine the central areas of activation by vagal nerve stimulation (VNS) in epilepsy. VNS is a promising neurosurgical method for treating patients with partial and secondary generalized epilepsy. The anti-epileptic mechanism of action from VNS is not well understood. METHODS We performed H2(15)O PET blood flow functional imaging on three patients with epilepsy in a vagal nerve stimulation study (E04 Protocol with Cyberonics). The three patients included two that had previous epilepsy surgery but continued to have frequent seizures. Seizure onset was frontal in two patients and bitemporal in the third patient. Twelve PET scans per subject were acquired every 10 minutes with a Siemens 953/A scanner. In 6 stimulus scans, VNS was activated for 60 seconds (2 mA, 30 Hz) commensurate with isotope injection. In 6 control scans no VNS was administered. No clinical seizures were present during any scan. Three way ANOVA with linear contrasts subject, task, repetition) of coregistered images identified significant treatment effects. RESULTS The difference between PET with VNS and without revealed that left VNS activated right thalamus (P < 0.0006), right posterior temporal cortex (P < 0.0003), left putamen (P < 0.0002), and left inferior cerebellum (P < 0.0009). CONCLUSIONS VNS causes activation of several central areas including contralateral thalamus. Localization to the thalamus suggests a possible mechanism to explain the therapeutic benefit, consistent with the role of the thalamus as a generator and modulator of cerebral activity.
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Ko D. Airline policy relating to passengers with epilepsy. ARCHIVES OF NEUROLOGY 1996; 53:405-6. [PMID: 8624214 DOI: 10.1001/archneur.1996.00550050027014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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DeLorenzo RJ, Hauser WA, Towne AR, Boggs JG, Pellock JM, Penberthy L, Garnett L, Fortner CA, Ko D. A prospective, population-based epidemiologic study of status epilepticus in Richmond, Virginia. Neurology 1996; 46:1029-35. [PMID: 8780085 DOI: 10.1212/wnl.46.4.1029] [Citation(s) in RCA: 685] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
This report presents the initial analysis of a prospective, population-based study of status epilepticus (SE) in the city of Richmond, Virginia. The incidence of SE was 41 patients per year per 100,000 population. The frequency of total SE episodes was 50 per year per 100,000 population. The mortality rate for the population was 22%, 3% for children and 26% for adults. Evaluation of the seizure types for adult and pediatric patients demonstrated that both partial and generalized SE occur with a high frequency in these populations. Based on the incidence of SE actually determined in Richmond, Virginia, we project 126,000 to 195,000 SE events with 22,200 to 42,000 deaths per year in the United States. The majority of SE patients had no history of epilepsy. These results indicate that SE is a common neurologic emergency.
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Ketter TA, Malow BA, Flamini R, Ko D, White SR, Post RM, Theodore WH. Felbamate monotherapy has stimulant-like effects in patients with epilepsy. Epilepsy Res 1996; 23:129-37. [PMID: 8964274 DOI: 10.1016/0920-1211(95)00089-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The objective of this study was to assess the psychiatric effects of the antiepileptic drug (AED) felbamate (FBM) in patients with epilepsy. FBM is a new AED with a novel putative (antiglutaminergic) mechanism. Older AEDs such as carbamazepine and valproate have psychotropic properties, but the psychiatric effects of FBM and other new antiglutamatergic AEDs remain to be determined. Thirty inpatients with refractory epilepsy were openly tapered off all AEDs in conjunction with intensive presurgical monitoring prior to a two week randomized double-blind parallel trial of FBM monotherapy versus placebo, followed by open FBM therapy. Psychopathology was rated with weekly psychiatric rating scales. Anxiety, depression and seizures increased significantly with AED discontinuation. Acute blind FBM monotherapy yielded antiepileptic and stimulant-like effects (insomnia, anorexia, and anxiety), but failed to influence AED withdrawal-emergent psychopathology. Restarting original AEDs resolved such pathology in FBM drop outs. Chronic open FBM also had stimulant-like effects, with half of the patients displaying psychiatric deterioration and the other half modest improvement compared to baseline therapies. Baseline insomnia and anxiety may be markers for poorer psychiatric responses to chronic open FBM. FBM had stimulant-like effects, lacked anxiolytic effects, and failed to attenuate AED withdrawal-emergent psychopathology. Baseline insomnia or anxiety may predict poorer psychiatric responses to FBM. Further studies are required to assess whether the novel psychiatric effects observed with FBM also occur with other new antiglutamatergic AEDs.
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Gonzalez GC, Bountzioukas S, Gonzalez ES, McMaster D, Ko D, Lederis K, Lukowiak K. Hypothalamic and extrahypothalamic sauvagine-like immunoreactivity in the bullfrog (Rana catesbeiana) central nervous system. J Comp Neurol 1996; 365:256-67. [PMID: 8822168 DOI: 10.1002/(sici)1096-9861(19960205)365:2<256::aid-cne4>3.0.co;2-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In the present study, immunocytochemistry and radioimmunoassay were used to investigate the presence of sauvagine in both hypothalamic and extrahypothalamic areas of the central nervous system (CNS) of the bullfrog (Rana catesbeiana) using a specific antiserum raised against synthetic non-conjugated sauvagine (SVG), a frog (Phyllomedusa sauvagei) skin peptide of the corticotropin-releasing factor (CRF) family. Sauvagine-immunoreactive (SVG-ir) bipolar neurons were found in the nucleus of the fasciculus longitudinalis medialis located in the rostral mesencephalic tegmentum. In the tectal mesencephalon, beaded SVG-ir fibres were present in the optic tectum, and in the torus semicircularis. Abundant SVG-ir varicose fibres were seen in the granulosa layer of the cerebellum, the nucleus isthmi, and the obex of the spinal cord. SVG-ir fibres were also seen by the alar plate of the rombencephalon. In the diencephalon, the antiserum stained parvocellular neurons of the preoptic nucleus (PON) which extended their dendrites into the cerebro-spinal fluid (CSF) of the third ventricle and projected their ependymofugal fibres to the zona externa (ZE) of the median eminence. Immunopositive fibres were also present in the medial forebrain bundle at the chiasmatic field, the posterior thalamus, the pretectal gray, and the ventrocaudal hypothalamus. In the telencephalon (forebrain), SVG-ir fibres were seen in the medial septum, the lateral septum, and the amygdala. The SVG immunoreactivity could not be detected after using the SVG antiserum previously immunoabsorbed with synthetic SVG (0.1 microM), but immunoblock of the antiserum with sucker (Catostomus commersoni) urotensin I (sUI), sole (Hippoglossoides elassodon) urotensin I, sucker CRF, rat/human CRF, or ovine CRF (0.1-10 microM) did not eliminate visualization of the immunoreactivity. In radioimmunoassay, the SVG antiserum did not crossreact with sUI, or the SVG fragments SVG1-16, SVG16-27, and SVG26-34, but it recognized the C-terminal fragment SVG35-40. Crossreaction with mammalian ovine CRF and rat/human CRF was negligible. Both hypothalamic and mesencephalic extracts gave parallel displacement curves to SVG. The results suggest the presence in the bullfrog brain of a SVG-like neuropeptide, i.e., a peptide of the CRF family, that either is SVG or shares high homology with the C-terminus of that peptide. The function of this neuropeptide in amphibians is not known at this time, but based on its anatomical distribution to the ZE it could affect the release of adrenocorticotropin (ACTH) or other substances from the amphibian pars distalis. Involvement of the SVG-like peptide in behavioural (forebrain), visual (thalamus-tegmentum mesencephali-pretectal gray-optic tectum), motor coordination (cerebellum), and autonomic (spinal) functions, as well as an undefined interaction with the CSF in the bullfrog, seems likely.
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Theodore WH, Albert P, Stertz B, Malow B, Ko D, White S, Flamini R, Ketter T. Felbamate monotherapy: implications for antiepileptic drug development. Epilepsia 1995; 36:1105-10. [PMID: 7588454 DOI: 10.1111/j.1528-1157.1995.tb00468.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We studied the effect of felbamate (FBM) monotherapy on seizure rate in patients with partial and secondarily generalized seizures undergoing presurgical monitoring at a single site. The study design was a double-blind placebo-controlled parallel monotherapy trial. Forty patients whose seizures had not been controlled by standard antiepileptic drugs (AEDs) were randomized. Seizure type was confirmed by video-EEG monitoring. All baseline AEDs were discontinued, and patients were drug-free for 5.3 +/- 2.4 days before randomization to FBM or placebo. After a 4-day titration, seizures were counted for 14 days. Patients receiving FBM had significantly lower seizure rates, whether all randomized patients, patients who survived titration, or study completers were compared. Eight of 19 placebo patients randomized to placebo, as compared with 13 of 21 receiving FBM, completed the 18-day study. Two FBM patients dropped out due to seizures, and 6 dropped out due to side effects, including anxiety, difficulty sleeping, abdominal discomfort, acute psychosis, and orobuccal dyskinesias. Ten placebo patients met the criteria for premature discontinuation owing to seizures, and 1 hd an episode of panic. There was no evidence of hepatic or hematologic toxicity. FBM reduces seizure frequency in patients with localization-related epilepsy.
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Abstract
Using univariate and multivariate regression analysis, we studied seizure duration, seizure type, age, etiologies, other clinical features, and mortality among 253 adults with status epilepticus (SE) admitted to the Medical College of Virginia. Cerebral vascular disease and discontinuation of antiepileptic drugs (AEDs) were the most prominent causes of SE, each accounting for approximately 22% of all patients in the series. The other principle etiologies were alcohol withdrawal, idiopathic, anoxia, metabolic disorders, hemorrhage, infection, tumor, drug overdose, and trauma. When the patients were divided into two groups, the group with SE lasting < 1 h had a lower mortality as compared with seizure duration > or = 1 h. Low mortality rates were noted in alcohol and AED discontinuation etiologies. Anoxia and increasing age were significantly correlated with higher mortality. The mortality rates of partial and generalized SE were not significantly different. Race and sex did not affect mortality significantly. Our findings represent the first multivariate analysis of predictive indicators of mortality in SE and demonstrate that specific factors influence mortality rate in SE.
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Eich DM, Nestler JE, Johnson DE, Dworkin GH, Ko D, Wechsler AS, Hess ML. Inhibition of accelerated coronary atherosclerosis with dehydroepiandrosterone in the heterotopic rabbit model of cardiac transplantation. Circulation 1993; 87:261-9. [PMID: 8419015 DOI: 10.1161/01.cir.87.1.261] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Accelerated coronary atherosclerosis has become a critical problem in cardiac transplantation. Although the pathogenesis of this disease is unknown, hypercholesterolemia has been shown to be a major risk factor. METHODS AND RESULTS To study this problem, a hypercholesterolemic rabbit model of heterotopic cardiac transplantation was developed to study accelerated graft atherosclerosis. Based on suggestions in the literature, it was hypothesized that dehydroepiandrosterone (DHEA) may retard the progression of the disease. Using semiquantitative light microscopy, a predilection for the development of small vessel occlusive disease in the transplanted hearts was found. Chronic DHEA administration produced a 45% reduction in the number of significantly stenosed vessels in the transplanted hearts (p < 0.05) compared with controls and a 62% reduction in the nontransplanted hearts (p < 0.05), yielding an overall 50% reduction in the number of significantly stenosed vessels in both the transplanted and nontransplanted hearts. This reduction in luminal stenosis was observed in the absence of any significant alterations in lipid profiles. CONCLUSIONS It is concluded that chronic DHEA administration in a hypercholesterolemic rabbit model of heterotopic cardiac transplantation significantly retards the progression of accelerated atherosclerosis in both the transplanted heart and in the native heart.
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Abstract
Status epilepticus (SE) is a major neurological and medical emergency associated with a high morbidity and mortality. Retrospective and prospective studies from the Medical College of Virginia Epilepsy Research Center have been utilized to investigate several clinical and epidemiological factors associated with SE. Univariate and multivariate logistic regression analysis of predictive indicators in patients with SE indicated that seizure duration, certain specific etiologies, and age were predictors of mortality. Sex, race, and certain other etiologies were not found to be factors that significantly affect mortality. These findings demonstrate that specific indicators are important in predicting mortality in SE. Preliminary prospective epidemiological data from Richmond, Virginia suggested that more than 250,000 cases of SE may occur annually in the United States with a mortality greater than 55,000 individuals. Studies comparing community and university hospitals in Richmond indicate that the mortality and clinical variables associated with SE in these two hospital populations are essentially identical. Further investigations employing prospective population-based studies are essential in evaluating the epidemiology and mortality of SE.
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Okawara Y, Ko D, Morley SD, Richter D, Lederis KP. In situ hybridization of corticotropin-releasing factor-encoding messenger RNA in the hypothalamus of the white sucker, Catostomus commersoni. Cell Tissue Res 1992; 267:545-9. [PMID: 1571966 DOI: 10.1007/bf00319377] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In situ hybridization procedure with a 32P-labelled synthetic oligonucleotide probe was used to detect corticotropin-releasing factor-encoding messenger RNA (CRF mRNA) in the hypothalamus of the white sucker, Catostomus commersoni. Adjacent sections were immunostained by a sucker CRF-specific antiserum. CRF mRNA-containing neurons were identified by autoradiography in the magnocellular and parvocellular subdivisions of the preoptic nucleus (PON). Many of these neurons were also immunostained by sucker antiserum, showing the same distribution patterns. These results confirm the presence of CRF mRNA and CRF peptide in the white sucker hypothalamus and support the view that the magnocellular and parvocellular neurons of the PON may be involved in the control of adrenocorticotropic hormone secretion from the pituitary in the white sucker.
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Raaphorst GP, Feeley MM, Martin L, Danjoux CE, Maroun J, Desanctis AJ, Ko D. Enhancement of sensitivity to hyperthermia by lonidamine in human cancer cells. Int J Hyperthermia 1991; 7:763-72. [PMID: 1940511 DOI: 10.3109/02656739109056445] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Human glioma (87MG) and squamous cell carcinoma of the head and neck UMSCC-1 were shown to be sensitized to hyperthermia by Lonidamine treatment before and during hyperthermia. The degree of thermal sensitization increased with increasing heating times and temperatures. In addition, the thermal sensitization by Lonidamine as well as cellular thermal sensitivity were dependent on pH and increased with the more acidic pH. Even though plateau phase cells were more thermally resistant than exponentially growing cells, Lonidamine treatment caused thermal sensitization under both conditions. These data show that Lonidamine may hold potential to enhance the effectiveness of hyperthermia in cancer treatment and that especially in tumours with low pH an enhanced therapeutic gain may be achieved.
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Gonzalez GC, Martinez-Padron M, Ko D, Lukowiak K, Lederis K. Urotensin I-like immunoreactivity in the central nervous system of Aplysia californica. Peptides 1991; 12:787-93. [PMID: 1788142 DOI: 10.1016/0196-9781(91)90134-b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In the present study the occurrence and localization of urotensin I (UI, a corticotropin releasing factor-like peptide) in the CNS of Aplysia californica were investigated by immunocytochemistry and radioimmunoassay. The RIA cross-reactivity pattern indicated that the UI antiserum used recognized an epitope in the C-terminal region of the UI, but it did not cross-react with mammalian corticotropin-releasing factor (CRF) and partially recognized sauvagine (SVG, a frog CRF-like peptide). The use of CRF-specific and sauvagine-specific antisera failed to give positive immunostaining. The application of UI antiserum (which does not cross-react with CRF in RIA) gave a positive staining, which was blocked by synthetic sucker (Catostomus commersoni) UI, but not by rat/human CRF (10 microM). On the basis of immunostaining and RIA parallel to fish UI displacement curves of cerebral ganglia extracts, the unknown UI/CRF-like substance in the Aplysia ganglia is likely to have greater homology with sucker UI than with the known CRF peptides. Urotensin I-immunoreactive (UI-ir) neurons were seen mainly in the F neuron clusters, located in the midline and rostrodorsal portion of the cerebral ganglia. Few UI-ir neurons were also found in the C and D neuron clusters of the cerebral ganglia, as well as in the left pleural and abdominal ganglia. In addition, numerous fine and coarse, and beaded UI-ir fibers were found in the cerebral commissure. UI-ir fibers were also seen in the neuropile of the buccal, pedal and pleural ganglia, and abdominal ganglion. A cuff-like arrangement of UI-ir fibers was seen in the supralabial nerves.(ABSTRACT TRUNCATED AT 250 WORDS)
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Raaphorst GP, Ko D, Feeley MM, Danjoux CE, Maroun J, Evans WK. The effect of lonidamine alone and in combination with cisplatin on in vitro growth and viability of lung squamous cell carcinoma cell lines. Anticancer Res 1991; 11:41-7. [PMID: 2018379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Two non small cell lung cancer (NSCLC) cell lines were tested in vitro to evaluate the effect of lonidamine, cisplatin and combinations of these two agents using different doses and schedules. Lonidamine alone at concentrations greater than 50 micrograms/ml caused inhibition of cell growth in both monolayer and spheroid cell cultures. Cisplatin at concentrations of 10-20 microM caused a concentration dependent toxicity and inhibited growth in monolayer and spheroid cell cultures. Combination treatment of lonidamine and cisplatin caused concentration dependent effects. For 25 micrograms/ml lonidamine, there was no additive and in some cases an antagonistic effect when used with cisplatin. For higher lonidamine concentrations (75 and 100 micrograms ml), an additive effect with cisplatin (10-15 microM) was observed. This effect saturated for cisplatin concentrations of 20 microM. These data show some potential for lonidamine and cisplatin combination therapy but treatment doses and schedules will have to be identified so that the additive effect can be achieved at concentrations clinically attainable.
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Ko D, Raaphorst GP, Feeley MM, Danjoux CE, Maroun JA, Evans WK. The in vitro effects of lonidamine combined with cisplatin in human small cell lung cancer cell lines. Anticancer Res 1991; 11:235-9. [PMID: 1850216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Two human small cell lung cancer (SCLC) cell lines were used to evaluate the in vitro response to lonidamine and cisplatin exposure. The two cell lines both showed growth inhibition when exposed to lonidamine alone at concentrations greater than 50 micrograms/ml; however, one cell line (H69) was more sensitive. When cisplatin was combined with lonidamine a synergistic interaction was observed when cells were exposed to 10 microM cisplatin for 1 hour combined with lonidamine at concentrations of 50 micrograms/ml or greater. At a concentration of 25 micrograms/ml lonidamine combined exposure with cisplatin had no effect on cell growth or viability.
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Belen'kiĭ MA, Bountzioukas S, Gonzales G, Ko D, Lederis K, Polenov AL. [The effect of dehydration on the functional activity of the interrenal gland in adenohypophysectomized Rana catesbeiana frogs. A preliminary report]. ZHURNAL EVOLIUTSIONNOI BIOKHIMII I FIZIOLOGII 1990; 26:340-6. [PMID: 2220204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A significant increase of the content of corticosterone in the blood collected from intravenous cannula or by intracardiac punction has been detected using radioimmunoassay in non-operated and adenohypophysectomized frogs Rana catesbeiana subjected to dehydration in 6.2% mannitol solution during 24 hours. The osmolality of the blood plasma of these animals also increases although less significantly than the growth of plasma corticosterone content. There is a tendency to substantial increase of plasma arginine-vasotocin level prior to the growth of corticosterone level, already after 6 hours of dehydration. Based on the present results and literature data, it is suggested that in adenohypophysectomized frogs lacking endogenous ACTH just the increase of blood arginine-vasotocin level results in a substantial activation of corticosteroid-producing cells of the interrenal gland and in the growth of plasma content of corticosterone.
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Suess U, Lawrence J, Ko D, Lederis K. Radioimmunoassays for fish tail neuropeptides: I. Development of assay and measurement of immunoreactive urotensin I in Catostomus commersoni brain, pituitary, and plasma. JOURNAL OF PHARMACOLOGICAL METHODS 1986; 15:335-46. [PMID: 3724203 DOI: 10.1016/0160-5402(86)90012-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Antisera were raised in rabbits using highly purified urotensin I (UI) or UI (4-41) conjugated with high-molecular-weight proteins. Antiserum 2U4, at a final dilution of 1:300,000, gave 50% binding to iodinated UI (specific activity 40-120 microCi/micrograms). Carp (Cyprinus carpio) and sucker (Catostomus commersoni) UI peptides cross-reacted completely with the antiserum. Results from cross-reactivity tests using various tryptic and Staphylococcus aureus protease fragments of UI indicated that the antigenic sites of the main antibody(ies) are directed against a part sequence in the C-terminal region of the peptide although antibodies with lower concentration or affinity, recognizing N-terminal region(s) of the peptide, are also present. No cross-reactivity was seen with insulin, secretin, vasoactive intestinal peptide or a structural UI-homolog, the ovine hypothalamic corticotropin-releasing factor, up to molar concentrations. Sauvagine, another structurally homologous peptide from frog skin, showed only 0.1% cross-reactivity. The urophysis-specific proteins, urophysins B and D, showed a low degree of cross-reactivity. Assays of serial dilutions of urophysis extracts from teleostean species yielded parallel displacement curves, except in the case of the pacific goby, Gillichthys mirabilis. Varying concentrations of immunoreactive UI were present in different regions of C. commersoni brain, spinal cord, and pituitary, and also in plasma. The measurement of 17.5 +/- 2.1 fmol UI/ml of plasma indicates that this assay may be used for the study of circulating UI peptide(s).
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Kobayashi Y, Lederis K, Rivier J, Ko D, McMaster D, Poulin P. Radioimmunoassays for fish tail neuropeptides: II. Development of a specific and sensitive assay for and the occurrence of immunoreactive urotensin II in the central nervous system and blood of Catostomus commersoni. JOURNAL OF PHARMACOLOGICAL METHODS 1986; 15:321-33. [PMID: 3724202 DOI: 10.1016/0160-5402(86)90011-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A sensitive radioimmunoassay (RIA) based on an antiserum to synthetic Gillichthys mirabilis urotensin II (UII) generated in rabbits, reacting with all known forms of the UII peptides, was developed. The UII was iodinated by either the chloramine-T or the lodogen method and was purified by high-pressure liquid chromatography. The antiserum, at a final dilution of 1:125,000, gave 50% binding of the iodinated UII. The sensitivity of the RIA was 1.8 +/- 0.2 pg/assay tube (1.2 +/- 0.2 fmol/tube; n = 7). Crossreactivity studies with various UII peptides, modified UII peptides, and fragments indicated that the immunoreactive recognition site of this antiserum is directed to the disulfide ring region (positions 6-11) of the UII peptides. Somatostatin 14, which has the part sequence 7-9 in common with UII peptides, did not crossreact. No detectable crossreactivity with urotensin I, urophysin B or D from Catostomus commersoni, arginine vasopressin, or arginine vasotocin could be shown. Displacement curves obtained with standard extracts of G. mirabilus urophyses were similar to those of synthetic G. mirabilus UII. comparison of RIA and bioassay of G. mirabilis urophysial extracts showed good correlation. Immunoreactive UII was detected in different parts of the brain, spinal cord, and blood of C. commersoni.
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Zeh JE, Ko D, Krogman BD, Sonntag R. A multinomial model for estimating the size of a whale population from incomplete census data. Biometrics 1986; 42:1-14. [PMID: 3719047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This paper adapts the removal method of population size estimation to the problem of estimating the size of the western Arctic stock of bowhead whales. The whales are counted during their spring migration as they pass two census camps located near Point Barrow, Alaska. Whales seen at the first camp are "removed" from the population of concern to the second camp, where only whales missed by the first camp are counted. If both camps were in operation throughout the migration and if the probability of missing a whale were constant, the removal method would provide a population size estimate based on a trinomial model in which the size of the population would be the number of trials, whales counted by each camp would provide the observed cell totals, and whales missed by both camps would represent an unobserved cell total. Since the probability of missing a whale depends on visibility, we model the population size as the sum of the number of trials of several independent trinomial distributions, each of which represents a particular visibility condition occurring during the census. To account for the fact that watch cannot be maintained at both camps throughout the migration, we derive a confidence interval estimate of the number of trials under a more general model allowing for incomplete observation of totals within particular cells as well as for completely unobserved cells.
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Parboosingh J, Lederis K, Ko D, Singh N. Vasopressin concentration in cord blood: correlation with method of delivery and cord pH. Obstet Gynecol 1982; 60:179-83. [PMID: 7155478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Cord plasma vasopressin concentration, determined by radioimmunoassay, was higher in arterial than in venous blood in 122 (84%) infants; the highest vasopressin values were recorded in 21 acidotic infants (mean cord pH, 7.13) delivered per vaginam and the lowest values in 50 infants delivered by cesarean section. Cord vasopressin levels were not elevated in infants delivered by cesarean section because of obstructed labor. There was a lack of correlation between vasopressin levels and the length of labor or cervical dilatation; a significant correlation was found between cord arterial vasopressin values and pH. Low vasopressin values were recorded in a group of 22 healthy infants (mean cord pH, 7.29) delivered by low forceps operation.
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Leung AK, McArthur RG, McMillan DD, Ko D, Deacon JS, Parboosingh JT, Lederis KP. Circulating antidiuretic hormone during labour and in the newborn. ACTA PAEDIATRICA SCANDINAVICA 1980; 69:505-10. [PMID: 7446100 DOI: 10.1111/j.1651-2227.1980.tb07122.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Using a high specificity radioimmunoassay, antidiuretic hormone (ADH) concentrations were measured in the plasma of 33 expectant mothers during labour, in cord arterial and venous plasma of their infants at the time of delivery (19 delivered vaginally; 14 delivered by Cesarean section) and in the plasma of the same infants in the first few days of life. Extremely high concentrations of ADH (about 50 times higher than adult basal concentrations) were present in cord arterial blood indicating active fetal production of ADH. Plasma ADH decreased rapidly within an hour after birth and usually fell to adult basal levels during the first day of life. Stressed babies and babies subjected to difficult deliveries had higher plasma levels of ADH.
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Moore GJ, Oudeman EM, Ko D, Nystrom DM. Synthesis of angiotensin II antagonists containing sarcosine in position 7. J Med Chem 1979; 22:1147-9. [PMID: 490564 DOI: 10.1021/jm00195a032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Analogues of the type [1-sarcosine,7-sarcosine, 8-X]angiotensin II, where X = isoleucine, leucine, alanine, methionine, O-methylthreonine, or DL-alloisoleucine, were synthesized by the solid-phase method and purified by partition chromatography, cation-exchange chromatography, and high-pressure liquid chromatography. In the isolated rat uterus, these analogues had activities of less than 0.1, less than 0.1, less than 0.1, less than 0.1, less than 0.1, and 0.7%, respectively, of the hyotropic activity of angiotensin II and inhibited the contractile response to angiotensin II with pA2 values of 8.1, 7.2, 6.7, 7.7, 7.4, and 8.4, respectively. In the vagotomized ganglion blocked rat, the analogues had 0.7, 0.21, 0.06, 0.72, 0.13, and 12.5%, respectively, of the pressor activity of angiotensin II.
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Ko D. [Intrauterine devices and uterine cancer--statistical re-evaluation of Ishibama's data]. SANFUJINKA NO JISSAI. PRACTICE OF GYNECOLOGY AND OBSTETRICS 1968; 17:606-14. [PMID: 5755143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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