226
|
Messer WS, Rajeswaran WG, Cao Y, Zhang HJ, el-Assadi AA, Dockery C, Liske J, O'Brien J, Williams FE, Huang XP, Wroblewski ME, Nagy PI, Peseckis SM. Design and development of selective muscarinic agonists for the treatment of Alzheimer's disease: characterization of tetrahydropyrimidine derivatives and development of new approaches for improved affinity and selectivity for M1 receptors. PHARMACEUTICA ACTA HELVETIAE 2000; 74:135-40. [PMID: 10812950 DOI: 10.1016/s0031-6865(99)00026-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cholinergic neurons degenerate in Alzheimer's disease, resulting in cognitive impairments and memory deficits, and drug development efforts have focused on selective M1 muscarinic agonists. 5-(3-Ethyl-1,2,4- oxadiazol-5-yl)-1,4,5,6-tetrahydropyrimidine trifluoroacetic acid (CDD-0102) stimulates M1 muscarinic receptors in rat brain [Messer, W.S., Jr., Abuh, Y.F., Liu, Y., Periyasamy, S., Ngur, D.O., Edgar, M.A., El-Assadi, A.A., Sbeih, S., Dunbar, P.G., Roknich, S., Rho, T., Fang, Z., Ojo, B., Zhang, H., Huzl, J.J., III, Nagy, P.I., 1997a. J. Med. Chem. 40, 1230-1246.] and improves memory function in rats with lesions of the basal forebrain cholinergic system. Moreover, CDD-0102 exhibits oral bioavailability, few side effects and low toxicity, and thus represents a viable candidate for clinical studies. Despite the development of functionally selective agonists such as xanomeline and CDD-0102, there is room for improvements in ligand affinity and selectivity. The high degree of amino acid homology within transmembrane domains has hindered the development of truly selective agonists. Site-directed mutagenesis, biochemical and molecular modeling studies have identified key amino acid residues such as Thr192 and Asn382 in the binding of agonist to M1 receptors [Huang, X.P., Nagy, P.I., Williams, F.E., Peseckis, S.M., Messer, W.S., Jr., 1999. Br. J. Pharmacol. 126, 735-745.]. Recent work has implicated residues at the top of transmembrane domain VI in the binding of muscarinic agonists and activation of M1 receptors [Huang, X.P., Williams, F.E., Peseckis, S.M., Messer, W.S., Jr., 1998. J. Pharmacol. Exp. Ther. 286, 1129-1139.]. Thus, residues such as Ser388 represent molecular targets for the further development of agonists with improved M1 receptor affinity, selectivity and activity.
Collapse
|
227
|
Ballard C, McKeith I, O'Brien J, Kalaria R, Jaros E, Ince P, Perry R. Neuropathological substrates of dementia and depression in vascular dementia, with a particular focus on cases with small infarct volumes. Dement Geriatr Cogn Disord 2000; 11:59-65. [PMID: 10705161 DOI: 10.1159/000017215] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The neuropathological substrates of dementia and depression were evaluated in 30 patients with cerebrovascular disease and significant cognitive impairment (VaD), with a particular focus on patients with small infarct volumes (<15 ml). VaD patients with small infarct volumes had a similar degree of cognitive impairment to those with larger infarct volumes (>15 ml) but were significantly more likely to be depressed and to have areas of microinfarction. A review of individual cases with small infarct volumes suggested that the combination of microinfarction, diffuse white matter disease and perivascular changes, or the overlap of neurodegenerative pathologies and microvascular changes were particularly important. Microinfarction was also significantly associated with major depression.
Collapse
|
228
|
Abstract
OBJECTIVE The aim of this paper is to summarise recent clinical and research findings with regard to dementia with Lewy bodies (DLB). METHOD A literature review (Medline) was carried out, as well as a review of reports of recent DLB symposia of international meetings and of other relevant papers and data known to the authors. RESULTS Dementia with Lewy bodies, as the disorder should be known, is the second commonest form of degenerative dementia, accounting for up to 20% cases in the elderly. It is characterised by fluctuating cognitive impairment, spontaneous parkinsonism and recurrent visual hallucinations. Consensus clinical and neuropathological criteria have been published. The clinical criteria have been shown to have high specificity, but may still lack sensitivity. Recognition of DLB is clinically important in view of the high incidence (60%) of adverse and life-threatening reaction to antipsychotics, the difference in prognosis and, possibly, the differential treatment response to cholinergic therapy. Neuroimaging changes have not been well described in DLB but some show promise as potential markers to differentiate DLB from AD. These include relative preservation of temporal lobe structures on magnetic resonance imaging and loss of pre- and postsynaptic dopaminergic markers on single photon emission tomography. CONCLUSIONS Dementia with Lewy bodies is a common cause of cognitive impairment in late life which appears to be clinically and neuropathologically distinct from AD. All clinicians should be aware of the typical triad of clinical features (fluctuating cognitive impairment, visual hallucinations and parkinsonism) which characterise the disorder and either avoid antipsychotics or prescribe them with extreme caution in such patients. Further research is likely to result in advances in diagnostic methods and therapeutics in the near future.
Collapse
|
229
|
Abstract
Ocular manifestations of systemic malignancy are important for both the ophthalmologist and the internist to recognize because they may precede the diagnosis of cancer. This review of the current literature discusses the clinical manifestations, etiology, and potential therapeutic interventions for a group of visual paraneoplastic syndromes, including carcinoma-associated retinopathy and melanoma-associated retinopathy. These conditions are characterized by elevated serum levels of autoantibodies directed against tumor antigen that cross-react with retinal proteins, resulting in rod and cone dysfunction. The clinical presentation, site of origin, frequency, and intraocular distribution of tumors metastatic to the eye are also reviewed.
Collapse
|
230
|
Moskowitz CH, Bertino JR, Glassman JR, Hedrick EE, Hunte S, Coady-Lyons N, Agus DB, Goy A, Jurcic J, Noy A, O'Brien J, Portlock CS, Straus DS, Childs B, Frank R, Yahalom J, Filippa D, Louie D, Nimer SD, Zelenetz AD. Ifosfamide, carboplatin, and etoposide: a highly effective cytoreduction and peripheral-blood progenitor-cell mobilization regimen for transplant-eligible patients with non-Hodgkin's lymphoma. J Clin Oncol 1999; 17:3776-85. [PMID: 10577849 DOI: 10.1200/jco.1999.17.12.3776] [Citation(s) in RCA: 254] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To evaluate a chemotherapy regimen that consisted of ifosfamide administered as an infusion with bolus carboplatin, and etoposide (ICE) supported by granulocyte colony-stimulating factor (G-CSF) for cytoreduction and stem-cell mobilization in transplant-eligible patients with primary refractory or relapsed non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS One hundred sixty-three transplant-eligible patients with relapsed or primary refractory NHL were treated from October 1993 to December 1997 with ICE chemotherapy at Memorial Sloan-Kettering Cancer Center. Administration of three cycles of ICE chemotherapy was planned at 2-week intervals. Peripheral-blood progenitor cells were collected after cycle 3, and all patients who achieved a partial response (PR) or complete response (CR) to ICE chemotherapy were eligible to proceed to transplantation. Event-free and overall survival, ICE-related toxicity, and the number of CD34(+) cells collected after treatment with ICE and G-CSF were evaluated. RESULTS All 163 patients were assessable for response, and there was no treatment-related mortality. A major response (CR/PR) was evident in 108 patients (66.3%); 89% of the responding patients underwent successful transplantation. Patient who underwent transplantation and achieved a CR to ICE had a superior overall survival to that of patients who achieved a PR (65% v 30%; P =.003). The median number of CD34(+) cells/kg collected was 8.4 x 10(6). The dose-limiting toxicity of ICE was hematologic, with 29.4% of patients developing grade 3/4 thrombocytopenia. There were minimal nonhematologic side effects. CONCLUSION ICE chemotherapy, with ifosfamide administered as a 24-hour infusion to decrease CNS side effects, and the substitution of carboplatin for cisplatin to minimize nephrotoxicity, is a very effective cytoreduction and mobilization regimen in patients with NHL. Furthermore, the quality of the clinical response to ICE predicts for posttransplant outcome.
Collapse
|
231
|
Evans AM, O'Brien J, Nation RL. Application of a loading wash-out method for investigating the hepatocellular efflux of a hepatically-generated metabolite, morphine-3-glucuronide. J Pharm Pharmacol 1999; 51:1289-97. [PMID: 10632087 DOI: 10.1211/0022357991776868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Previous studies using the rat isolated perfused liver demonstrated that the hepatic disposition of morphine-3-glucuronide is membrane permeability-rate limited, and that the movement of the metabolite across hepatic sinusoidal and canalicular membranes is partly via carrier-mediated transport systems. As a consequence of the membrane permeability-limitation, the biliary excretion of hepatically-generated morphine-3-glucuronide is much more efficient than that of morphine-3-glucuronide reaching the liver via the vasculature. We have quantitated the cellular efflux kinetics (cell-to-blood and cell-to-bile) of morphine-3-glucuronide in the rat isolated perfused liver using a loading wash-out design. In the 'loading' phase, morphine was infused into the liver (2.7 microM) and the biliary excretion and sinusoidal efflux of morphine-3-glucuronide was assessed under steady-state conditions. Subsequently, the infusion was stopped and the concentration vs time profile of morphine-3-glucuronide in outflow perfusate (the wash-out phase) was determined. A physiologically-based pharmacokinetic model was used to determine the rate-constants for the movement of hepatically-generated morphine-3-glucuronide into the sinusoidal and canalicular spaces of the liver, and the associated membrane permeability terms. The mean (+/-s.d.) rate constants for the biliary excretion and sinusoidal efflux of morphine-3-glucuronide were determined to be 0.160 +/- 0.043 and 0.169 +/- 0.068 min(-1), respectively, and the corresponding membrane permeability parameters were 1.12 and 1.18 mL min(-1), respectively. The sinusoidal membrane permeability term was significantly less than hepatic blood flow in the rat. The volume of distribution of hepatically-generated morphine-3-glucuronide (207.5 +/- 74.8 mL) was found to be approximately 50-times the intracellular space of the rat liver, suggesting that hepatically-generated morphine-3-glucuronide accumulates within hepatocytes. The results indicate that hepatically-generated morphine-3-glucuronide undergoes intracellular accumulation, probably as a consequence of poor membrane permeability.
Collapse
|
232
|
Herwig R, Poustka AJ, Müller C, Bull C, Lehrach H, O'Brien J. Large-scale clustering of cDNA-fingerprinting data. Genome Res 1999; 9:1093-105. [PMID: 10568749 PMCID: PMC310829 DOI: 10.1101/gr.9.11.1093] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Clustering is one of the main mathematical challenges in large-scale gene expression analysis. We describe a clustering procedure based on a sequential k-means algorithm with additional refinements that is able to handle high-throughput data in the order of hundreds of thousands of data items measured on hundreds of variables. The practical motivation for our algorithm is oligonucleotide fingerprinting-a method for simultaneous determination of expression level for every active gene of a specific tissue-although the algorithm can be applied as well to other large-scale projects like EST clustering and qualitative clustering of DNA-chip data. As a pairwise similarity measure between two p-dimensional data points, x and y, we introduce mutual information that can be interpreted as the amount of information about x in y, and vice versa. We show that for our purposes this measure is superior to commonly used metric distances, for example, Euclidean distance. We also introduce a modified version of mutual information as a novel method for validating clustering results when the true clustering is known. The performance of our algorithm with respect to experimental noise is shown by extensive simulation studies. The algorithm is tested on a subset of 2029 cDNA clones coming from 15 different genes from a cDNA library derived from human dendritic cells. Furthermore, the clustering of these 2029 cDNA clones is demonstrated when the entire set of 76,032 cDNA clones is processed.
Collapse
|
233
|
Dragoli DR, Thompson LA, O'Brien J, Ellman JA. Parallel synthesis of prostaglandin E1 analogues. JOURNAL OF COMBINATORIAL CHEMISTRY 1999; 1:534-9. [PMID: 10748730 DOI: 10.1021/cc990033e] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The first demonstration of the rapid parallel synthesis of diverse prostaglandin derivatives is reported. Upper (alpha-) side chain diversity was introduced to core 1 via the parallel Suzuki coupling of hydroborated alkenes. Conversion to the enones 3 and 9 was followed by the addition of the lower (omega-) side chains as higher-order cuprates 4. Upper side chains incorporating an N-acylsulfonamide protecting group were further transformed into prostaglandin amide analogues. Cleavage from support with HF/pyridine followed by scavenging provided 26 prostaglandin E1 analogues in high purity.
Collapse
|
234
|
Westbroek J, Saarelainen S, Laher M, O'Brien J, Barnacle H, Efthimiou J. Oral steroid-sparing effect of two doses of nebulized fluticasone propionate and placebo in patients with severe chronic asthma. Respir Med 1999; 93:689-99. [PMID: 10581657 DOI: 10.1016/s0954-6111(99)90035-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Inhaled steroids, delivered by metered dose aerosol and dry powder inhalers, have proved effective in reducing the need for oral steroids in patients with oral steroid-dependant asthma. This randomized, double-blind study, compared the efficacy and tolerability of nebulized fluticasone propionate (FP Nebules), 2 mg b.d. (FP 4 mg) and 0.5 mg b.d. (FP 1 mg) with placebo, on the reduction of oral steroid requirement in 301 adult patients with oral steroid-dependent asthma. Primary efficacy was assessed by the reduction in daily oral steroid dose. Secondary efficacy parameters included daily diary card peak expiratory flow (PEF), day and night-time symptoms and clinic lung function measurements. Safety was assessed by adverse event monitoring and serum cortisol levels. After 12 weeks of treatment the adjusted mean +/- SEM reduction in oral prednisolone was significantly greater in the FP 4 mg group (4.44 +/- 0.98 mg day-1) compared with FP 1 mg (2.16 +/- 1.00 mg day-1, P = 0.039) and placebo (1.20 +/- 1.02 mg day-1, P = 0.004). A higher percentage of patients discontinued the use of oral steroids with FP 4 mg (37%) compared with FP 1 mg (26%, P = 0.038) and placebo (18%, P < 0.001). Following treatment, the adjusted mean morning PEF showed a trend in favour of FP 4 mg (280 +/- 41 min-1) compared with placebo (270 +/- 51 min-1, P = 0.053) and the evening PEF was significantly higher with FP 4 mg (305 +/- 41 min-1) compared with FP 1 mg (292 +/- 41 min-1, P = 0.010). FP 4 mg resulted in a significantly higher percentage of days when the patients were free from daytime (P = 0.036) and night-time (P = 0.021) wheeze, compared with placebo. Significantly fewer patients withdrew from the FP 4 mg group compared with the other two groups (vs. FP 1 mg, P = 0.003; vs. placebo, P = 0.032). All three treatments were well tolerated and the incidence of adverse events was similar between the groups. FP Nebules at a daily dose of between 1 and 4 mg are a safe and effective means of reducing the oral steroid requirement of patients with chronic oral steroid dependent asthma.
Collapse
|
235
|
Cribbs RK, Ishaq M, Arnold M, O'Brien J, Lamb J, Frankel WL. Renal cell carcinoma with massive osseous metaplasia and bone marrow elements. Ann Diagn Pathol 1999; 3:294-9. [PMID: 10556476 DOI: 10.1016/s1092-9134(99)80025-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Focal calcifications are frequently seen in renal masses and may be present in renal cell carcinomas. Metaplastic bone formation, on the other hand, is a rare event. We report a unique case of a large calcified renal cell carcinoma with massive osseous metaplasia and bone marrow elements. The clinical and pathologic differential diagnosis for this tumor is discussed along with a review of the literature on this unusual phenomenon.
Collapse
|
236
|
Ballard C, O'Brien J. Treating behavioural and psychological signs in Alzheimer's disease. BMJ (CLINICAL RESEARCH ED.) 1999; 319:138-9. [PMID: 10406732 PMCID: PMC1116255 DOI: 10.1136/bmj.319.7203.138] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
237
|
Barber R, Scheltens P, Gholkar A, Ballard C, McKeith I, Ince P, Perry R, O'Brien J. White matter lesions on magnetic resonance imaging in dementia with Lewy bodies, Alzheimer's disease, vascular dementia, and normal aging. J Neurol Neurosurg Psychiatry 1999; 67:66-72. [PMID: 10369824 PMCID: PMC1736409 DOI: 10.1136/jnnp.67.1.66] [Citation(s) in RCA: 301] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVES Alzheimer's disease and vascular dementia are associated with an increase in changes in white matter on MRI. The aims were to investigate whether white matter changes also occur in dementia with Lewy bodies and to examine the relation between white matter lesions and the cognitive and non-cognitive features of dementia with Lewy bodies, Alzheimer's disease, and vascular dementia. METHODS Proton density and T2 weighted images were obtained on a 1.0 Tesla MRI scanner in patients with dementia with Lewy bodies (consensus criteria; n=27, mean age=75.9 years), Alzheimer's disease (NINCDS/ADRDA; n=28, mean age=77.4 years), vascular dementia (NINDS/AIREN; n=25, mean age=76.8 years), and normal controls (n=26, mean age=76.2 years). Cognitive function, depressive symptoms, and psychotic features were assessed using a standardised protocol. Periventricular hyperintensities (PVHs), white matter hyperintensities (WMHs) and basal ganglia hyperintensities (BGHs) were visually rated blind to diagnosis using a semiquantitative scale. RESULTS Periventricular hyperintensities were positively correlated with age and were more severe in all dementia groups than controls. Total deep hyperintensities scores (WMHs plus BGHs) were significantly higher in all dementia groups than controls and higher in patients with vascular dementia than those with dementia with Lewy bodies or Alzheimer's disease. In all patients with dementia, frontal WMHs were associated with higher depression scores and occipital WMHs were associated with an absence of visual hallucinations and delusions. CONCLUSION In common with Alzheimer's disease and vascular dementia, PVHs and WMHs were significantly more extensive in dementia with Lewy bodies than in controls. This overlap between different dementias may reflect shared pathological mechanisms. The link between frontal WMHs and depression and the absence of occipital WMHs and psychotic symptoms has important implications for understanding the neurobiological basis of these symptoms.
Collapse
|
238
|
Ballard C, Holmes C, McKeith I, Neill D, O'Brien J, Cairns N, Lantos P, Perry E, Ince P, Perry R. Psychiatric morbidity in dementia with Lewy bodies: a prospective clinical and neuropathological comparative study with Alzheimer's disease. Am J Psychiatry 1999; 156:1039-45. [PMID: 10401449 DOI: 10.1176/ajp.156.7.1039] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The literature reports considerable variation in the rates of psychiatric morbidity for patients with dementia with Lewy bodies. The authors intended to clarify the frequency of psychiatric morbidity in dementia with Lewy bodies and how it differs from probable Alzheimer's disease. METHOD The study incorporated two groups--a clinical case register cohort (98 with dementia with Lewy bodies; 92 with Alzheimer's disease) and 80 (40 with dementia with Lewy bodies: 40 with Alzheimer's disease) prospectively studied, neuropathologically confirmed cases. Diagnoses were made by using the McKeith et al. consensus criteria for dementia with Lewy bodies and the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association criteria for Alzheimer's disease. Neuropathological diagnoses were made by using the consensus criteria for dementia with Lewy bodies and the Mirra et al. protocol for Alzheimer's disease. RESULTS The occurrence of psychiatric symptoms was reported over 1 month. Hallucinations, depression, delusions, and delusional misidentification were all significantly higher for patients with dementia with Lewy bodies. The differences in frequency between dementia with Lewy bodies and Alzheimer's disease for auditory and visual hallucinations were especially pronounced for patients with mild cognitive impairment. The presence of psychiatric symptoms at presentation was a better discriminator between dementia with Lewy bodies and Alzheimer's disease than occurrence over the course of dementia. CONCLUSIONS Delusional misidentification and hallucinations in the early stages of dementia may improve differentiation between patients with dementia with Lewy bodies and those with Alzheimer's disease and have important treatment implications.
Collapse
|
239
|
Janoff EN, Tasker SA, Stevenson M, Rubins JB, O'Brien J, Utz G, Weiss P, Hall FW, Wallace MR. Immune activation and virologic response to immunization in recent HIV type 1 seroconverters. AIDS Res Hum Retroviruses 1999; 15:837-45. [PMID: 10381172 DOI: 10.1089/088922299310746] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Antigenic stimulation from invasive bacterial infections, and the vaccines designed to prevent them, may promote T cell activation and enhancement of HIV-1 replication. Changes in viral load have been correlated with antigen-specific responses. We prospectively determined the impact of immunization with 23-valent pneumococcal vaccine (PVAX) and Haemophilus influenzae type b (Hib)-modified diphtheria toxoid CRM197 (DT) vaccine on HIV-1 replication in recent HIV-1 seroconverters (n = 14; median, 5.5 months from infection; median CD4+ T cells, 535 microl), and correlated results with vaccine-related immune activation. Specific antibody responses, markers of CD4+ T cell activation (transferrin and interleukin 2 receptors), and viral burden were measured at weeks -2 (pre), 0, 1, 2, 6, and 12 after immunization. By week 2, levels of IgG had increased significantly over baseline in both HIV-1-infected patients and HIV-1-seronegative control subjects (n = 9) for each antigen (geometric mean fold rise: PVAX, 10.1 versus 5.3; Hib, 16.0 versus 11.7; and DT, 26.2 versus 24.5, respectively). Despite these vigorous responses to both polysaccharide and protein antigens, HIV-1-infected patients showed limited evidence of CD4+ T cell activation at 1 week, no consistent rise in HIV-1 burden at any point, and no decline in CD4+ T cell number over time. We conclude that recent HIV-1 seroconverters show vigorous humoral responses to vaccine antigens and limited early evidence of T cell activation, but no substantial or sustained increase in viral replication or decline in CD4+ T cell number. Thus, respiratory bacterial vaccines appear immunogenic and safe early in HIV-1 infection.
Collapse
|
240
|
White TW, Deans MR, O'Brien J, Al-Ubaidi MR, Goodenough DA, Ripps H, Bruzzone R. Functional characteristics of skate connexin35, a member of the gamma subfamily of connexins expressed in the vertebrate retina. Eur J Neurosci 1999; 11:1883-90. [PMID: 10336656 DOI: 10.1046/j.1460-9568.1999.00607.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Retinal neurons are coupled by electrical synapses that have been studied extensively in situ and in isolated cell pairs. Although many unique gating properties have been identified, the connexin composition of retinal gap junctions is not well defined. We have functionally characterized connexin35 (Cx35), a recently cloned connexin belonging to the gamma subgroup expressed in the skate retina, and compared its biophysical properties with those obtained from electrically coupled retinal cells. Injection of Cx35 RNA into pairs of Xenopus oocytes induced intercellular conductances that were voltage-gated at transjunctional potentials >/= 60 mV, and that were also closed by intracellular acidification. In contrast, Cx35 was unable to functionally interact with rodent connexins from the alpha or beta subfamilies. Voltage-activated hemichannel currents were also observed in single oocytes expressing Cx35, and superfusing these oocytes with medium containing 100 microm quinine resulted in a 1.8-fold increase in the magnitude of the outward currents, but did not change the threshold of voltage activation (membrane potential = +20 mV). Cx35 intercellular channels between paired oocytes were insensitive to quinine treatment. Both hemichannel activity and its modulation by quinine were seen previously in recordings from isolated skate horizontal cells. Voltage-activated currents of Cx46 hemichannels were also enhanced 1. 6-fold following quinine treatment, whereas Cx43-injected oocytes showed no hemichannel activity in the presence, or absence, of quinine. Although the cellular localization of Cx35 is unknown, the functional characteristics of Cx35 in Xenopus oocytes are consistent with the hemichannel and intercellular channel properties of skate horizontal cells.
Collapse
|
241
|
Marwah GS, O'Brien J, Gewolb IH. Effect of acute glucose depletion following glucose excess on surfactant phospholipid synthesis in developing fetal lung. Exp Lung Res 1999; 25:291-302. [PMID: 10378101 DOI: 10.1080/019021499270204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Exposure to high glucose and insulin inhibits surfactant synthesis in vitro. We have demonstrated that fetal lung insulin receptor tyrosine kinase (TK) activity is downregulated after culture in high glucose plus insulin, with a resultant decrease in glucose uptake. To see whether relative substrate depletion following substrate excess would further diminish surfactant synthesis, 20-day fetal rat lung explants were initially cultured for 44 hours in media containing 100 mM glucose with or without 0.1 U/mL insulin, followed by a 4-hour pulse in 10 mM glucose +/- insulin or 100 mM glucose +/- insulin, after which the rate of choline incorporation into phosphatidylcholine (PC) or disaturated PC was measured. Choline incorporation was significantly lower after a 4-hour pulse in low glucose (+/- insulin) than under continuing high glucose (+/- insulin) conditions (P < .01). To determine the time required for reversal of TK downregulation in lung explants, insulin receptor TK activity was assayed after 44 hours in high glucose + insulin, followed by an additional 4, 8, 12, or 24 hours in either 10 mM glucose or continued 100 mM glucose + insulin. After 44 hours in 50 mM or 100 mM glucose + insulin, TK activity was significantly decreased (68 +/- 9% and 57 +/- 9% of control; P < .01). When explants cultured in 100 mM glucose + insulin for 44 hours were subsequently placed in 10 mM glucose for an additional 4 or 8 hours, TK activity remained significantly downregulated (70.2 +/- 7.0% and 84.9 +/- 5.5% of control, respectively, P < .05) compared to explants cultured in low glucose throughout. However, after 12 or 24 hours in low glucose, TK activity was no longer significantly different from control values (106.5 +/- 2.1% and 106.0 +/- 19.6%, respectively). Culture of type II cells for 44 hours in 25 mM glucose + insulin, followed by an additional 4 or 24 hours in either low glucose (5.5 mM) + insulin or high glucose (25 mM) + insulin yielded similar results: TK activity was decreased 20-30% by culture in 25 mM glucose + insulin conditions (P < .05) and this downregulation continued for 4 (but not 24) hours after switching to lower glucose conditions (P < .05). Continued receptor downregulation during a period of relative substrate deprivation may adversely affect surfactant synthesis, as in some infants of diabetic mothers who experience hypoglycemia (following intrauterine hyperglycemia) in the immediate postnatal period.
Collapse
|
242
|
Nishikibe M, Ohta H, Okada M, Ishikawa K, Hayama T, Fukuroda T, Noguchi K, Saito M, Kanoh T, Ozaki S, Kamei T, Hara K, William D, Kivlighn S, Krause S, Gabel R, Zingaro G, Nolan N, O'Brien J, Clayton F, Lynch J, Pettibone D, Siegl P. Pharmacological properties of J-104132 (L-753,037), a potent, orally active, mixed ETA/ETB endothelin receptor antagonist. J Pharmacol Exp Ther 1999; 289:1262-70. [PMID: 10336515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
J-104132 [(+)-(5S,6R, 7R)-2-butyl-7-[2-((2S)-2-carboxypropyl)-4-methoxyphenyl]-5-(3, 4-methylenedioxyphenyl)cyclopenteno[1,2-b]pyridine-6-carboxylic; also referred to as L-753,037] is a potent, selective inhibitor of ETA and ETB endothelin (ET) receptors (e.g., Ki: cloned human ETA = 0.034 nM; cloned human ETB = 0.104 nM). In both ligand-binding and isolated tissue preparation protocols, the inhibition of ET receptors with J-104132 is reversible and competitive. In vitro, J-104132 is a potent antagonist of ET-1-induced accumulation of [3H]inositol phosphates in Chinese hamster ovary cells stably expressing cloned human ETA receptors (IC50 = 0.059 nM), ET-1-induced contractions in rabbit iliac artery (pA2 = 9.70) and of BQ-3020-induced contractions in pulmonary artery (pA2 = 10.14). J-104132 is selective for ET receptors because it had no effect on contractions elicited by norepinephrine or KCl in the vascular preparations. The in vivo potency of J-104132 was assessed using challenges with exogenous ET-1. In conscious mice, 5 nmol/kg i.v. ET-1 causes death. Pretreatment with J-104132 prevents the lethal response to ET-1 when administered i.v. (ED50 = 0.045 mg/kg) or p.o. in fed animals (ED50 = 0.35 mg/kg). In conscious, normotensive rats, pressor responses to 0.5 nmol/kg i.v. ET-1 are inhibited by J-104132 after i.v. (0.1 mg/kg) or p.o. (1 mg/kg) administration. In anesthetized dogs, ET-1 was administered directly into the renal artery or brachial artery to generate dose-response (blood flow) curves, and the inhibitory potency of J-104132 (i.v. infusion) was quantified. J-104132 produced greater than 10-fold shifts in the ET-1 dose-response curves at 0.03 mg/kg/h (renal) and 0.3 mg/kg/h (brachial). Oral bioavailability of J-104132 in rats was approximately 40%. These studies indicate that J-104132 is a selective, potent, orally active antagonist of both ETA and ETB receptors and is an excellent pharmacological tool to explore the therapeutic use of a mixed ETA/ETB receptor antagonist.
Collapse
MESH Headings
- Animals
- Binding, Competitive
- Blood Pressure/drug effects
- CHO Cells
- Cloning, Molecular
- Cricetinae
- Dogs
- Endothelin Receptor Antagonists
- Endothelin-1/metabolism
- Female
- Hippocampus/physiology
- Humans
- Iliac Artery/drug effects
- Iliac Artery/physiology
- In Vitro Techniques
- Male
- Mice
- Mice, Inbred Strains
- Muscle Contraction/drug effects
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Phosphatidylinositols/metabolism
- Pulmonary Artery/drug effects
- Pulmonary Artery/physiology
- Pyridines/pharmacology
- Pyridines/toxicity
- Rabbits
- Rats
- Rats, Sprague-Dawley
- Receptor, Endothelin A
- Receptor, Endothelin B
- Receptors, Endothelin/genetics
- Recombinant Proteins/antagonists & inhibitors
- Renal Artery/drug effects
- Renal Artery/physiology
- Transfection
- Uterus/physiology
Collapse
|
243
|
Hildmann T, Kong X, O'Brien J, Riesselman L, Christensen HM, Dagand E, Lehrach H, Yaspo ML. A contiguous 3-Mb sequence-ready map in the S3-MX region on 21q22.2 based on high- throughput nonisotopic library screenings. Genome Res 1999; 9:360-72. [PMID: 10207158 PMCID: PMC310729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Progress in complete genomic sequencing of human chromosome 21 relies on the construction of high-quality bacterial clone maps spanning large chromosomal regions. To achieve this goal, we have applied a strategy based on nonradioactive hybridizations to contig building. A contiguous sequence-ready map was constructed in the Down syndrome congenital heart disease (DS-CHD) region in 21q22.2, as a framework for large-scale genomic sequencing and positional candidate gene approach. Contig assembly was performed essentially by high throughput nonisotopic screenings of genomic libraries, prior to clone validation by (1) restriction digest fingerprinting, (2) STS analysis, (3) Southern hybridizations, and (4) FISH analysis. The contig contains a total of 50 STSs, of which 13 were newly isolated. A minimum tiling path (MTP) was subsequently defined that consists of 20 PACs, 2 BACs, and 5 cosmids covering 3 Mb between D21S3 and MX1. Gene distribution in the region includes 9 known genes (c21-LRP, WRB, SH3BGR, HMG14, PCP4, DSCAM, MX2, MX1, and TMPRSS2) and 14 new additional gene signatures consisting of cDNA selection products and ESTs. Forthcoming genomic sequence information will unravel the structural organization of potential candidate genes involved in specific features of Down syndrome pathogenesis.
Collapse
|
244
|
Ballard CG, Ayre G, O'Brien J, Sahgal A, McKeith IG, Ince PG, Perry RH. Simple standardised neuropsychological assessments aid in the differential diagnosis of dementia with Lewy bodies from Alzheimer's disease and vascular dementia. Dement Geriatr Cogn Disord 1999; 10:104-8. [PMID: 10026383 DOI: 10.1159/000017109] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Consecutive patients from a dementia case register received a standardised evaluation which incorporated a neuropsychological assessment with the Cambridge Assessment for disorders in the elderly (CAMCOG). Operationalised clinical diagnoses were made (consensus criteria for dementia with Lewy bodies, DLB; NINCDS- ADRDA for Alzheimer's disease, AD, NINCDS AIRENS for vascular dementia, VaD). Two-hundred and twenty-eight patients were studied (DLB 54, AD102, VaD 72). DLB patients had significantly better performance on recent memory than AD patients, but more impaired visuospatial praxis. DLB patients also had significantly better recent memory than those with VaD. Optimal cut-off points for the recent memory:praxis ratio achieved good discrimination between DLB and both other dementias.
Collapse
|
245
|
Miles D, O'Brien J, Owen M. Involvement of radon levels in lung cancer. Br J Cancer 1999; 79:1621-3. [PMID: 10188918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
|
246
|
Gewolb IH, O'Brien J, Slavin RE. Opioids accelerate fetal rat lung maturation in vitro. Am J Respir Cell Mol Biol 1999; 20:511-6. [PMID: 10030850 DOI: 10.1165/ajrcmb.20.3.3083] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Infants born to heroin- and cocaine-addicted mothers have been reported to have a lower incidence of respiratory distress syndrome (RDS) compared with nonaddicted infants. However, it is not known whether these are direct drug-mediated effects or secondary phenomena. We therefore investigated the effect of opioids and cocaine on fetal rat lung maturation in vitro. Using 18- to 20-d fetal rat lung explants and 20-d fetal type II cells, we measured the effect of varying concentrations (1 x 10(-8) to 1 x 10(-3) M) of heroin, morphine, methadone, and the nonopioid cocaine on the rate of choline incorporation into phosphatidylcholine (PC) and disaturated PC. We also analyzed the morphology of 19-d explants after exposure to opioids. Significant increases in rate of choline incorporation were noted in 19- and 20-d explants using 1 x 10(-3) M heroin, 1 x 10(-3) M morphine, and 1 x 10(-4) M methadone (P < 0. 005). No acceleratory effect was seen with cocaine. Morphologic analysis of the three opioid-treated groups revealed a significant (192 to 251%) increase in type II pneumocytes and lamellar bodies per alveolar lining cell (P < 0.01). Choline incorporation into PC by type II cells was also significantly increased by opioids (P < 0. 01); lactate dehydrogenase release and cell viability were not affected by opioid treatment. These data indicate that high-dose opioids have an acceleratory effect on biochemical and morphologic parameters of fetal lung maturation in vitro. The lack of in vitro acceleration with cocaine suggests that any cocaine-related reduction in the incidence of RDS is a secondary effect.
Collapse
|
247
|
O'Brien J, Ames D, Chiu E, Schweitzer I, Desmond P, Tress B. Severe deep white matter lesions and outcome in elderly patients with major depressive disorder: follow up study. BMJ (CLINICAL RESEARCH ED.) 1998; 317:982-4. [PMID: 9765166 PMCID: PMC28682 DOI: 10.1136/bmj.317.7164.982] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To determine the difference in outcome among elderly people with major depression who do and do not have severe white matter lesions on magnetic resonance imaging. DESIGN Follow up study. SETTING Two psychiatric and two general hospitals in Melbourne, Australia. SUBJECTS 60 depressed subjects aged over 55 referred to hospital psychiatric services with major depressive disorder meeting American Psychiatric Association (DSM-IIIR) criteria. MAIN OUTCOME MEASURE Proportion with good outcome as determined by full recovery from initial illness and no evidence of depressive relapse or cognitive decline during follow up among those with and without lesions. RESULTS Mean (SD) follow up was 31.9 (9.9) months. Survival analysis showed a significant effect of severe lesions on time to poor outcome (P=0.04), with median survival 136 days in those with severe lesions compared with 315 days in those without. CONCLUSION Severe white matter change on magnetic resonance imaging is associated with poor outcome in elderly depressed subjects.
Collapse
|
248
|
O'Brien J, Bruzzone R, White TW, Al-Ubaidi MR, Ripps H. Cloning and expression of two related connexins from the perch retina define a distinct subgroup of the connexin family. J Neurosci 1998; 18:7625-37. [PMID: 9742134 PMCID: PMC6793016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/1998] [Revised: 07/06/1998] [Accepted: 07/14/1998] [Indexed: 02/08/2023] Open
Abstract
We have cloned cDNAs for two closely related connexins (Cx), Cx35 and Cx34.7, from a perch retinal cDNA library. Sequencing of PCR products from genomic DNA revealed that both connexins have an intron 71 bp after the translation initiation site; in Cx35, the intron is 900 bp in length, whereas in Cx34.7 it is approximately 20 kb. Southern blots of genomic DNA suggest that the two connexins represent independent single copy genes. In Northern blots, Cx35 and Cx34.7 transcripts were detected in retina and brain; Cx34.7 also showed a weak signal in smooth muscle (gut) RNA. Antibodies against Cx35 labeled a 30 kDa band on a Western blot of retinal membranes, and in histological sections, the pattern of antibody recognition was consistent with labeling of bipolar cells and unidentified processes in the inner plexiform and nerve fiber layers. When expressed in Xenopus oocytes, Cx35 and Cx34.7 formed homotypic gap junctions, but the junctional conductance between paired oocytes expressing Cx35 was 10-fold greater than that recorded for gap junctional channels formed by Cx34.7. The homotypic gap-junctional channels were closed in a voltage-dependent manner but with relatively weak voltage sensitivity. Heterotypic gap junctions formed by Cx35 and Cx34.7 displayed junctional conductances similar to those of Cx34.7 homotypic pairs and showed a slightly asymmetric current-voltage relationship; the side expressing Cx35 exhibited a higher sensitivity to transjunctional potentials. An analysis of the sequence and gene structure of the connexin family revealed that perch Cx35 and Cx34.7, skate Cx35, and mouse Cx36 constitute a novel gamma subgroup.
Collapse
|
249
|
French N, Gilks CF, Mujugira A, Fasching C, O'Brien J, Janoff EN. Pneumococcal vaccination in HIV-1-infected adults in Uganda: humoral response and two vaccine failures. AIDS 1998; 12:1683-9. [PMID: 9764789 DOI: 10.1097/00002030-199813000-00017] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To assess the feasibility of establishing a pneumococcal vaccine trial among HIV-1-infected adults in Uganda and to characterize their responses to 23-valent pneumococcal polysaccharide vaccine. DESIGN An open-label pilot trial to assess recruitment and compliance of HIV-1-infected adults in Uganda to vaccination and to determine the immunogenicity of the vaccine. SETTING A community clinic for HIV-1-infected adults in Entebbe, Uganda. METHODS Levels of capsule-specific IgG to four common vaccine capsular serotypes were measured before vaccination and 1 month after vaccination. Subsequent rates of disease episodes and deaths, and immunologic responses in two vaccine failures, were followed. RESULTS One month after-vaccination, both HIV-1-infected (n = 77) and seronegative control subjects (n = 10) demonstrated a significant rise in capsule-specific immunoglobulin G (IgG) for three of four serotypes tested, but levels were significantly lower among HIV-1-infected patients. In 149 patient-years of follow-up, two (2.6%) developed pneumococcal pneumonia, one bacteremic with serotype 1 and one non-bacteremic with serotype 13, a non-vaccine serotype; both patients showed inadequate killing of the organism in vitro. In this same follow-up period, 29 (38%) patients died. CONCLUSION HIV-1-infected adults in Uganda are at high risk of pneumococcal disease and show a significant but suboptimal response to pneumococcal vaccine. Although reliable recruitment and follow-up of vaccinees is feasible, evaluation of vaccine efficacy may be compromised by limited responses to common vaccine serotypes, an unknown incidence of disease with non-vaccine serotypes, and a high rate of mortality unrelated to Streptococcus pneumoniae infection.
Collapse
|
250
|
Ballard CG, O'Brien J, Lowery K, Ayre GA, Harrison R, Perry R, Ince P, Neill D, McKeith IG. A prospective study of dementia with Lewy bodies. Age Ageing 1998; 27:631-6. [PMID: 12675102 DOI: 10.1093/ageing/27.5.631] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND little is known about the longitudinal course of dementia with Lewy bodies (DLB) and how this differs from Alzheimer's disease (AD). METHOD standardized baseline and annual assessments of cognitive and non-cognitive symptoms are reported in a cohort of 72 patients with DLB or AD. AD was diagnosed using the NINCDS ADRDA criteria and DLB was diagnosed with the criteria of McKeith et al. Cognitive assessment was undertaken using the MMSE schedule and operationalized definitions were used to diagnose non-cognitive symptoms. RESULTS 42 patients with DLB and 30 patients with AD were assessed. Of the 19 on whom post mortem examinations have been performed, 18 (95%) have had the clinical diagnosis confirmed. DLB patients were significantly more likely to experience visual hallucinations, disturbances of consciousness and parkinsonism at both baseline and at annual assessments. Of DLB patients exposed to neuroleptics, 33% developed sensitivity reactions. The magnitude and pattern of cognitive decline was similar in both groups. CONCLUSION the importance of the core features highlighted in the newly proposed consensus DLB criteria is supported. These features appear to be stable over time.
Collapse
|