76
|
McAllum P, Barnes R, Dickson J. Ocular dangers of fencing wire. THE NEW ZEALAND MEDICAL JOURNAL 2001; 114:332-3. [PMID: 11548099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
AIMS To invesitgate the incidence and severity of penetrating eye injuries caused by fencing wire in the Waikato region. METHODS We reviewed the case notes for all penetrating eye injuries treated at Waikato Hospital during the past six years. Parameters recorded were patient age and sex, mechanism of injury, initial visual acuity, characteristics of injury, surgery performed and final visual outcome. RESULTS The incidence of penetrating eye injuries in the Waikato region was 3.8 per 100,000 per year, based on an estimated catchment population of 350,000. We found fencing wire to be the third most common cause of penetrating eye injury, accounting for 8.8% of injuries, behind motor vehicle accidents and hammering which accounted for 26.3% and 20.0% of injuries, respectively. The fencing wire injuries involved men exclusively, with an average age of 41.7 years. Fencing wire injuries had worse presenting visual acuity than other injuries, involved the posterior segment of the eye more frequently and were more likely to develop bacterial endophthalmitis. They also underwent more surgical procedures and were more commonly associated with a poor visual outcome. CONCLUSIONS Fencing wire is an important cause of visual loss in the Waikato region. We hope to raise awareness of its potential ocular dangers and to promote the use of appropriate eye protection.
Collapse
|
77
|
Jones RC, Dickson J. Imidazoline pseudodipeptides as mimics of reverse turn structures. J Pept Sci 2001; 7:220-3. [PMID: 11354465 DOI: 10.1002/psc.319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The synthesis of an imidazoline dipeptide mimetic (a 4,5-dihydroimidazole-4-carboxylic acid) is reported that displays an intramolecular hydrogen-bond consistent with a turn conformation in solution.
Collapse
|
78
|
Dickson J, Hunt DD. The prevalence of vitamin A deficiency in 1994 on an atoll of the Marshall Islands and its relationship to locally grown food. PACIFIC HEALTH DIALOG 2001; 8:54-8. [PMID: 12017837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
In an area of the world not previously studied for the presence of nutritional deficiencies, this study conducted in 1994, examined the prevalence of Vitamin A deficiency on a representative atoll of the Marshall Islands. All children ages three through ten living on Mili atoll were surveyed. The study was conducted house-to-house with all 38 subjects on the atoll voluntarily enrolling in the study. Vitamin A status was assessed by conjunctival impression cytology with transfer ([CT), clinical ophthalmic signs, and nutritional survey in all children ages three through ten living on Mili atoll, Republic of the Marshall Islands. Forty-seven percent had xerophthannia (5% with XN, 39% with XN + XIA, and 3% with XN + XIB). More than three-quarters (78%) were ICT abnormal, indicating 31% of the population had mild sub-clinical vitamin A deficiency. Eighty-six percent of the children had not received the U.S. recommended daily allowance of vitamin A in the previous week. Oiven the World Health Organization's published guidelines that anything greater than a 1% prevalence, Vitamin A deficiency on Mili atoll may be classified as a significant public health problem.
Collapse
|
79
|
Van Essen DC, Drury HA, Dickson J, Harwell J, Hanlon D, Anderson CH. An integrated software suite for surface-based analyses of cerebral cortex. J Am Med Inform Assoc 2001; 8:443-59. [PMID: 11522765 PMCID: PMC131042 DOI: 10.1136/jamia.2001.0080443] [Citation(s) in RCA: 901] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The authors describe and illustrate an integrated trio of software programs for carrying out surface-based analyses of cerebral cortex. The first component of this trio, SureFit (Surface Reconstruction by Filtering and Intensity Transformations), is used primarily for cortical segmentation, volume visualization, surface generation, and the mapping of functional neuroimaging data onto surfaces. The second component, Caret (Computerized Anatomical Reconstruction and Editing Tool Kit), provides a wide range of surface visualization and analysis options as well as capabilities for surface flattening, surface-based deformation, and other surface manipulations. The third component, SuMS (Surface Management System), is a database and associated user interface for surface-related data. It provides for efficient insertion, searching, and extraction of surface and volume data from the database.
Collapse
|
80
|
Abstract
This paper describes the synthesis of two diastereoisomers of an imidazoline dipeptide mimetic (a 4,5 dihydroimidazole-4-carboxylic acid), suitably protected for incorporation into solid phase peptide synthesis (SPPS) using the Fmoc protocol, from a phenylalanine-derived thioimidate and an alpha,beta-diaminopropanoic acid ester, followed by protecting group manipulation.
Collapse
|
81
|
Dickson J, Davidson SE, Hunter RD, West CM. Pretreatment plasma TGF beta 1 levels are prognostic for survival but not morbidity following radiation therapy of carcinoma of the cervix. Int J Radiat Oncol Biol Phys 2000; 48:991-5. [PMID: 11072155 DOI: 10.1016/s0360-3016(00)00729-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE To determine whether pretreatment plasma-transforming growth factor beta 1 (TGF beta 1) levels are prognostic for tumor control and late morbidity following radiation therapy in carcinoma of the cervix. METHODS AND MATERIALS The study was comprised of 79 patients undergoing radiotherapy with curative intent for Stage I-III carcinoma of the cervix. TGF beta 1 levels were analyzed using ELISA. Late morbidity was measured using the Franco-Italian glossary. Data were available for the pretreatment levels of circulating tumor markers that represent disease burden, and for peripheral blood lymphocyte radiosensitivity measured as SF2. RESULTS Pretreatment TGF beta 1 levels were a significant prognostic factor for survival and local control. There were weak significant correlations of TGF beta 1 levels with disease stage and the levels of circulating tumor markers (CA125, TPA). There was a weak significant correlation between TGF beta 1 levels and normal cell radiosensitivity (lymphocyte SF2). There was no relationship between TGF beta 1 levels and grade of morbidity and pretreatment TGF beta 1 levels were not a significant prognostic factor for the probability of developing late morbidity. CONCLUSION In carcinoma of the cervix, pretreatment TGF beta 1 levels reflect tumor burden and are a significant prognostic factor for survival. Despite an underlying weak relationship of TGF beta 1 levels with intrinsic normal cell radiosensitivity, pretreatment levels are not prognostic for the probability of developing late complications. This finding does not rule out the possible usefulness of measurements toward the end of treatment once tumor burden has been reduced.
Collapse
|
82
|
Moffat DF, Oien KA, Dickson J, Habeshaw T, McLellan DR. Hepatocellular carcinoma after long-term tamoxifen therapy. Ann Oncol 2000; 11:1195-6. [PMID: 11061618 DOI: 10.1023/a:1008354429921] [Citation(s) in RCA: 18] [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
We describe a case of hepatocellular carcinoma (HCC) after long term tamoxifen therapy in a 71-year-old woman. The patient was prescribed tamoxifen for 12 years following right mastectomy and axillary node clearance for breast carcinoma in 1985. In 1997, she complained of abdominal pain and fullness. An abdominal ultrasound scan showed lesions in the right lobe of liver which were thought to be metastases. However, a biopsy showed primary HCC. Studies in rats suggest that tamoxifen is involved in hepatic carcinogenesis but studies in humans have failed to show any increased risk. However, these studies followed up patients for less than five years. An increased risk of HCC may not become apparent until after a decade or more of tamoxifen therapy. In addition, HCC in tamoxifen treated patients may be under-reported since there may be reluctance to biopsy liver tumours which are assumed to be secondary carcinoma of the breast.
Collapse
|
83
|
Abstract
OBJECTIVES This study examined the prevalence and biosocial correlates of hysterectomy. METHODS Data were from a 1995 national survey of women aged 20 to 59 years. We applied piecewise nonparametric exponential hazards models to a subsample aged 25 to 59 to estimate the effects of biosocial correlates on hysterectomy likelihood. RESULTS Risks of hysterectomy for 1991 through 1995 were lower than those before 1981. University-educated and professional women were less likely to undergo hysterectomy. Higher parity and intrauterine device side effects increased the risk. CONCLUSIONS This study confirms international results, especially those on education and occupation, but also points to ethnicity's mediating role. Education and occupation covary independently with hysterectomy. Analysis of time variance and periodicity showed declines in likelihood from 1981.
Collapse
|
84
|
Dickson J, McLennan J, Omodei MM. Effects of concurrent verbalization on a time-critical, dynamic decision-making task. THE JOURNAL OF GENERAL PSYCHOLOGY 2000; 127:217-28. [PMID: 10843263 DOI: 10.1080/00221300009598580] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The authors investigated the effects of concurrent verbalization on students' performance on a time-critical, dynamic decision-making task. After training on Fire Chief (a computer microworld that simulates fighting a forest fire; M. M. Omodei & A. J. Wearing, 1993a), 60 research participants were allocated randomly to 1 of 3 experimental conditions: silence, associative verbalization, or procedural verbalization. Participants who verbalized the bases of their decisions (procedural verbalization) performed significantly worse on average than participants in the silence condition. There was a small but non-significant decrement in the performance of participants who verbalized thoughts other than the bases of their decisions while performing the task (associative verbalization). Their average level was between the levels of participants in the silence and procedural-verbalization conditions.
Collapse
|
85
|
Dickson J. Shoulder injections in primary care. THE PRACTITIONER 2000; 244:259-65. [PMID: 10859813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
|
86
|
Dicks J, Anderson M, Cardle L, Cartinhour S, Couchman M, Davenport G, Dickson J, Gale M, Marshall D, May S, McWilliam H, O'Malia A, Ougham H, Trick M, Walsh S, Waugh R. UK CropNet: a collection of databases and bioinformatics resources for crop plant genomics. Nucleic Acids Res 2000; 28:104-7. [PMID: 10592194 PMCID: PMC102397 DOI: 10.1093/nar/28.1.104] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The UK Crop Plant Bioinformatics Network (UK CropNet) was established in 1996 in order to harness the extensive work in genome mapping in crop plants in the UK. Since this date we have published five databases from our central UK CropNet WWW site (http://synteny.nott.ac.uk/) with a further three to follow shortly. Our resource facilitates the identification and manipulation of agronomically important genes by laying a foundation for comparative analysis among crop plants and model species. In addition, we have developed a number of software tools that facilitate the visualisation and analysis of our data. Many of our tools are made freely available for use with both crop plant data and with data from other species.
Collapse
|
87
|
Macdonald PJ, Chan C, Dickson J, Jean-Louis F, Heath A. Ophthalmomyiasis and nasal myiasis in New Zealand: a case series. THE NEW ZEALAND MEDICAL JOURNAL 1999; 112:445-7. [PMID: 10678243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
We report three cases of ophthalmomyiasis in New Zealand, due to the larvae of Oestrus ovis. All three patients reported eye injury caused by a fly. The larvae were removed from the conjunctival sac without difficulty under local anaesthesia. Presenting ocular symptoms of foreign body sensation, irritation, redness and photophobia all resolved swiftly. Topical antibiotic and steroid eye drops were administered. All three patients also developed nasal symptoms such as sneezing, nasal discharge and epistaxis. Otolaryngology follow-up demonstrated nasal myiasis in two patients which was treated with nasal decongestants. In addition, all three patients were treated with ivermectin (Mectizan).
Collapse
|
88
|
Canney PA, Deehan C, Glegg M, Dickson J. Reducing cardiac dose in post-operative irradiation of breast cancer patients: the relative importance of patient positioning and CT scan planning. Br J Radiol 1999; 72:986-93. [PMID: 10673950 DOI: 10.1259/bjr.72.862.10673950] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Left-sided post-operative radiotherapy fields for the treatment of breast cancer inevitably encompass the heart within the treatment volume, resulting in late mortality which may negate the cause-specific survival advantage of the therapy. The effect of positioning was studied in 11 patients with left-sided tumours and five with right-sided tumours receiving routine post-operative radiotherapy to the breast or chest wall as part of primary therapy for breast cancer. Using the same arrangement of glancing fields for each patient treatment position, the optimum patient positioning resulted in a reduction in cardiac dose compared to our standard patient treatment position. On the left side the reduction in mean cardiac dose was 60% (p < 0.001) and the reduction in maximum dose was 32% (p < 0.001); on the right it was 17% and 31%, respectively. The volume of cardiac tissue irradiated was also reduced for all patients. Using this optimum treatment position, cardiac dose was investigated in a further 10 patients with left-sided tumours and our standard glancing field set-up was compared with 3-dimensional planning. A further reduction of 12% in the mean cardiac dose was achieved. 5 of 10 patients had a further small reduction of 4.6% in the maximum dose and one patient had a further reduction in maximum dose of 58%. In conclusion, sophisticated radiotherapy planning can reduce cardiac doses, but optimum patient positioning is of greater importance. The general application of such relatively simple measures could have a significant positive effect on overall survival from breast cancer.
Collapse
|
89
|
Oien KA, Moffat D, Curry GW, Dickson J, Habeshaw T, Mills PR, MacSween RN. Cirrhosis with steatohepatitis after adjuvant tamoxifen. Lancet 1999; 353:36-7. [PMID: 10023952 DOI: 10.1016/s0140-6736(05)74872-8] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
90
|
Dickson J. A new kind of clinic for arthritis? THE PRACTITIONER 1998; 242:733. [PMID: 10441887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
|
91
|
|
92
|
Canney P, Dickson J, Glegg M, Deehan C. 0-88. Reducing cardiac doses in post-operative irradiation of breast cancer patients. Breast 1997. [DOI: 10.1016/s0960-9776(97)90669-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
93
|
|
94
|
Ryrie IW, Dickson J, Robbins C, Maclean K, Climpson C. Evaluation of a low-threshold clinic for opiate-dependent drug users. J Psychiatr Ment Health Nurs 1997; 4:105-10. [PMID: 9224006 DOI: 10.1046/j.1365-2850.1997.00038.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study reports on the development and outcome of a Low Threshold Clinic (LTC) for opiate-dependent drug users. The service originated as a nursing initiative within an inner city Drug Dependency Centre (DDC) and its rationale and treatment approach are explored in relation to the literature and local circumstances. Client baseline and outcome data were systematically gathered to assess service uptake and service efficacy in terms of client outcome. Data are presented for the first two years of operation during which a total of 59 clients entered the LTC. The sociodemographic characteristics and patterns of drug use among this group suggest the service was successful in targeting clients who previously failed to enter traditional treatment programmes despite initial referral to the DDC. Outcome data indicate a tendency for clients to inject less frequently, engage in less criminal activity and, by 12 months, to reduce their dose of prescribed methadone whilst attending the LTC. Tentative conclusions are drawn concerning the value of this service for 'hard-to-reach' drug users and those who may be at a precontemplation stage of change. Recommendations are made for a more comprehensive evaluative study that involves comparison with other treatment approaches.
Collapse
|
95
|
Oksche A, Möller A, Dickson J, Rosendahl W, Rascher W, Bichet DG, Rosenthal W. Two novel mutations in the aquaporin-2 and the vasopressin V2 receptor genes in patients with congenital nephrogenic diabetes insipidus. Hum Genet 1996; 98:587-9. [PMID: 8882880 DOI: 10.1007/s004390050264] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The vasopressin V2 receptor (V2R) and the aquaporin-2 genes of two unrelated male patients with congenital nephrogenic diabetes insipidus were analyzed. The V2R gene of the patient of family 1 had the wild-type sequence. Consequently, the coding region of the aquaporin-2 gene including the exon-intron junctions was sequenced. A novel G to T transversion at codon 202, predictive of an exchange of tryptophan 202 by cysteine, was identified. As the mutation occurs at G-1 of the 5' splice donor site of intron 3, aberrant splicing is also likely. The mutation involves one of the supposed water pore-forming loops. Therefore, both aberrant splicing and amino acid substitution are likely to result in a functionally defective protein. Sequencing of the complete V2R gene of the male patient of family 2 revealed a novel single-base deletion at codon 310 (delta C1001), shifting the reading frame to give an altered amino acid sequence beginning at codon 311. The mutation is unique in predicting a C-terminally extended protein (termination after codon 434 in the mutant receptor instead of codon 371 in the wild-type). The deduced mutant protein is likely to be nonfunctional since the amino acid sequence of the seventh transmembrane domain and the C-terminus is altered.
Collapse
|
96
|
Oksche A, Schülein R, Rutz C, Liebenhoff U, Dickson J, Müller H, Birnbaumer M, Rosenthal W. Vasopressin V2 receptor mutants that cause X-linked nephrogenic diabetes insipidus: analysis of expression, processing, and function. Mol Pharmacol 1996; 50:820-8. [PMID: 8863826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We investigated the biochemical and functional properties of five vasopressin V2 receptor mutants (L44F, L44P, W164S, S167L, and S167T) that were recently described in families with a history of X-linked nephrogenic diabetes insipidus. COS.M6 cells transfected with cDNA encoding these mutants acquired < 4% specific [3H]arginine vasopressin (AVP) binding sites on the cell surface in comparison with cells transfected with cDNA coding for the wild-type receptor. Membrane preparations from COS.M6 cells or human embryonic kidney 293 cells expressing these mutants did not respond with an increase in adenylyl cyclase activity in response to AVP, which is in contrast to membranes from cells expressing the wild-type. By analyzing fusion proteins of the V2 receptor and Escherichia coli alkaline phosphatase attached to the carboxyl terminus of the receptor moiety, we found that the mutants L44P, W164S, S167L, and S167T lacked complex glycosylation and were expressed at low levels. The data suggest that the mutants L44P, W164S, S167T, and S167L are misfolded and therefore retained within the endoplasmic reticulum and degraded. In contrast, the fusion proteins carrying the mutant L44F and the in vitro mutant S167A were expressed in their mature form at wild-type levels; however, only the mutant S167A was functionally active. Site-directed mutagenesis of S167 revealed that elimination of the endogenous hydroxyl group (S167A) yielded a protein with properties identical to those of the wild-type receptor, whereas both the introduction of a methyl group (S167T) and the replacement of the hydroxyl group by an isopropyl group (S167L) profoundly disturbed receptor processing. The data show that minute changes at codon 167 nearly abolish expression of a mature protein, thus defining structural requirements of this codon.
Collapse
|
97
|
Dickson J, Jones S. Frictional characteristics of a modified ceramic bracket. JOURNAL OF CLINICAL ORTHODONTICS : JCO 1996; 30:516-8. [PMID: 10356535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
|
98
|
Zhao Y, Sebranek JG, Dickson J, Lee M. Bacteriological, Physicochemical, and Sensory Quality of Fresh Pork Chops with Low-Dose Irradiation and Modified-Atmosphere Packaging. J Food Prot 1996; 59:493-501. [PMID: 31159061 DOI: 10.4315/0362-028x-59.5.493] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The combined effects of low-dose irradiation and modified-atmosphere packaging treatments were studied with respect to survival and growth of salmonellae and changes in physicochemical and sensory characteristics of fresh pork loin chops. Fresh trimmed pork loin chops were inoculated with salmonellae (about 103 to l04 CFU/g), packaged with air, vacuum, 25% CO2, 50% CO2, or 75% CO2 balanced with N2, and irradiated by 0 or 1.0 kGy electron beam. All samples were stored at 2 to 4°C for 2 weeks, followed by storage at 25°C for 1 day. Uninoculated samples were also subjected to the same treatments and stored at the same refrigeration temperature for 4 weeks with weekly measurements of color, purge loss, and thiobarbituric acid (TBA) values, as well as panel evaluations for color and odor. The number of salmonellae was initially reduced by 0.3 to 1.4 log cycles by 1.0 kGy irradiation, depending on packaging atmospheres applied. Salmonellae were more sensitive to irradiation in the presence of air. Using combinations of 1.0 kGy irradiation with a vacuum or elevated CO2 levels resulted in no survival of salmonellae after 2 weeks of storage at 2 to 4°C, and no further recovery after one more day at abuse temperature. Combined treatments also helped to slow the physicochemical and sensory changes in irradiated fresh pork chops. Vacuum packaging maintained pink color in irradiated pork, but showed greater purge loss and relatively high TBA values in comparison with CO2 atmospheres; all CO2 atmospheres resulted in less desirable irradiated pork color after 2 weeks of storage.
Collapse
|
99
|
Dickson J. Corticosteroid joint injection: how to avoid the risks. THE PRACTITIONER 1995; 239:370, 374, 377-9. [PMID: 7659658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
100
|
Abstract
Abnormalities within second messenger systems have been hypothesized as the underlying pathophysiologic mechanism in a variety of neuropsychiatric disorders. In the Gilles de la Tourette syndrome (TS) prior studies have shown that the concentration of adenosine 3',5'-monophosphate (cAMP) is reduced in cortical and putamen brain regions. In this study, postmortem cortical tissues from 4 adults (mean age 59.5 years) with the lifetime diagnosis of TS and 5 controls (mean age 63.8 years) were analyzed for functional activities within the cAMP and phosphoinositide systems. In addition, plasma cAMP was quantified in children with TS (n = 33) and controls (n = 17). In frontal (A4, A6) and occipital (A17) cortical tissues there were no significant differences for adenylyl cyclase activity whether assayed under basal conditions or after stimulation with GTP gamma S (a non-hydrolyzable GTP analog), forskolin (a selective enzyme stimulator), or (-)-isoproterenol (a beta-adrenergic agonist). D2 receptor activation (quinpirole) and assessment of the inhibitory guanine nucleotide protein also showed no significant alterations in TS samples. Activity of cAMP phosphodiesterase was increased insignificantly in A4 and A17 TS brain regions. Plasma concentrations of cAMP in plasma were similar in children with TS (135.4 +/- 8.3 pmol/ml) and controls (132.6 +/- 7.9 pmol/ml). Postmortem membrane receptor binding for markers within the phosphoinositide (PI) system showed that TS samples had increased [3H]phorbol ester binding to protein kinase C sites in area A17, but normal binding in A4. In contrast, [3H] inositol 1,4,5-triphosphate binding to IP3 receptors showed no significant changes.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|