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Zheng J, Nicholson RA. Influence of two naturally occurring abietane monocarboxylic acids (resin acids) and a chlorinated derivative on release of the inhibitory neurotransmitter gamma-aminobutyric acid from trout brain synaptosomes. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 1996; 56:114-120. [PMID: 9026144 DOI: 10.1007/s001289900017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Nicholson RA, Ekenstam C, Norwood S. Coercion and the outcome of psychiatric hospitalization. INTERNATIONAL JOURNAL OF LAW AND PSYCHIATRY 1996; 19:201-217. [PMID: 8725657 DOI: 10.1016/0160-2527(96)00005-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Abstract
OBJECTIVE The authors evaluated the interrater reliability of ratings of bizarre delusions, addressing limitations of previous studies. METHOD Fifty randomly selected psychiatrists rated bizarre delusions in 30 case vignettes adapted from a previous study by Spitzer and associates. Estimates of reliability were obtained for definitions of bizarre delusions in the DSM-III, DSM-III-R, and draft DSM-IV criteria for schizophrenia and for the clinicians grouped according to their current and previous experience with psychotic patients. RESULTS The kappas for ratings of bizarre delusions according to the different definitions and among clinicians with different levels of experience were in the moderate to fair range. CONCLUSIONS The reliability of ratings of bizarre delusions appears to be less than satisfactory for clinical practice, and the increased weight given to this symptom in modern diagnostic systems does not seem justifiable.
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Goulding H, Jasani B, Pereira H, Reid A, Galea M, Bell JA, Elston CW, Robertson JF, Blamey RW, Nicholson RA. Metallothionein expression in human breast cancer. Br J Cancer 1995; 72:968-72. [PMID: 7547250 PMCID: PMC2034037 DOI: 10.1038/bjc.1995.443] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Metallothioneins are ubiquitous low molecular weight proteins characterised by high cysteine content and affinity for binding heavy metals. Abnormal metallothionein function and expression have been implicated in various disease states, including neoplasia. The aim of this study was to investigate metallothionein expression in human breast carcinoma. Sections of routinely fixed and processed blocks of tumour from 100 consecutive cases of primary operable breast carcinoma were stained for metallothionein using a recently developed monoclonal antibody and a standard immunohistochemical technique. Expression was scored on the basis of microscopical assessment of percentage of tumour cells staining. One patient was lost to follow-up and excluded from the study. A significant association (P < 0.0001) was observed between metallothionein expression and tumour type, with low levels being observed in tumours of good prognostic type. There was also a significant association with local recurrence (P < 0.02) and a significant difference (P < 0.02) in both survival and disease-free interval between tumours showing low and high levels of expression, the latter indicating a poor prognosis. No relationship was observed with patient age, tumour size, lymph node stage, histological grade, vascular invasion, menopausal status or oestrogen receptor status. The assessment of metallothionein expression in human breast cancer appears to provide prognostic information and may have important implications for understanding its development.
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Nicholson RA. Technical note: the relationship between TV position and the effectiveness and comfort of protective spectacles in fluoroscopic procedures. Br J Radiol 1995; 68:1021-4. [PMID: 7496684 DOI: 10.1259/0007-1285-68-813-1021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Although interventional radiological procedures can result in significant eye doses to an operator, protective measures are often rejected because screens are found to impede manipulations, and 0.5 mm lead equivalent spectacles are heavy and uncomfortable. With many units the TV monitors are positioned so that the operator needs to turn his head through 80 degrees or more to view the image while screening. The aim of this study was to determine the distribution of the shielding in protective spectacles which will combine maximum dose reduction for different TV positions with minimum weight. Thermoluminescent dosimeters were used to assess the effectiveness of various spectacles in shielding the lens of the eye when a skull phantom was orientated at different angles in a large area beam of X-rays generated at a tube potential typical of diagnostic energies. The beam was tilted upwards at an angle of 20 degrees as though originating from the irradiated volume of a patient. The results showed that if weight was a consideration, and the head was turned away from the image intensifier through an angle greater than 80 degrees, the shielding was most effective when concentrated in the side-panels of the spectacles. The shape of the side-panels, however, was critical to the adequate shielding of this radiation.
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Nicholson RA. Potential gonadal dose from leakage radiation? Br J Radiol 1995; 68:547-8. [PMID: 7788248 DOI: 10.1259/0007-1285-68-809-547-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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Nicholson RA, Thornton A, Akpan M. Radiation dose reduction in paediatric fluoroscopy using added filtration. Br J Radiol 1995; 68:296-300. [PMID: 7735770 DOI: 10.1259/0007-1285-68-807-296] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Studies on a water phantom indicate that the insertion of extra tube filtration combined with the removal of the antiscatter grid can reduce the total energy imparted from paediatric fluoroscopy by a factor of more than four when automatic exposure control is used. The omission of the grid is responsible for up to 40% of the reduction while the addition of 0.7 mm steel filtration is found to account for a further reduction in energy imparted of between 57% and 70%, for depths of water simulating small patients of 6-16 cm thickness. For all contrast paediatric examinations the reduction in image quality was considered to be small and the diagnostic information unimpaired with the filter in place.
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Nicholson RA. The siting of consistency checks on mobile image intensifier automatic brightness controls. Br J Radiol 1994; 67:1281. [PMID: 7874433 DOI: 10.1259/0007-1285-67-804-1281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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Nicholson RA. Excitatory actions of dehydroabietic acid on mammalian synaptosomes. PHARMACOLOGY & TOXICOLOGY 1994; 75:274-9. [PMID: 7870698 DOI: 10.1111/j.1600-0773.1994.tb00360.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The presynaptic effects of dehydroabietic acid were investigated using mouse brain synaptosomes as the in vitro model. At concentrations ranging from 10 to 100 microM, dehydroabietic acid depolarises the synaptosomal membrane and causes pronounced release of the neurotransmitters gamma-aminobutyric acid, acetylcholine and L-glutamate. The effects on membrane potential and transmitter release occur predominantly at concentrations below which any lytic actions of this compound can be detected. Dehydroabietic acid-induced depolarisation and release of neurotransmitters are not influenced by tetrodotoxin and are associated with only marginal inhibition of membrane-associated ATPase activity. When synaptosomes are challenged with dehydroabietic acid in calcium-free saline, a partial reduction in the stimulated release of transmitters is observed. These results provide clear evidence that dehydroabietic acid is neuroactive and capable of causing substantial increases in the release of both excitatory and inhibitory neurotransmitter substances. The mechanism which underlies the neuroexcitatory effects of dehydroabietic acid remains to be resolved however it is proposed that release of transmitters from central nerve endings may be a contributory factor in the toxicity of resin acids.
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Zhang A, Nicholson RA. RH-3421, a potent dihydropyrazole insecticide, inhibits depolarization-stimulated rises in free [Ca2+] and 45Ca2+ uptake in mammalian synaptosomes. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART C, PHARMACOLOGY, TOXICOLOGY & ENDOCRINOLOGY 1994; 108:307-10. [PMID: 7881802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The dihydropyrazole RH-3421 inhibits veratridine- and K(+)-induced rises in synaptosomal free Ca2+ with IC50s of 0.2 and 1 microM, respectively. The K(+)-induced rise in free synaptosomal Ca2+, which requires external Ca2+, is also blocked by RH-3421 in the presence of tetrodotoxin. The K(+)-stimulated 45Ca2+ uptake by synaptosomes is unaffected by tetrodotoxin, blocked by cobalt ions and inhibited by RH-3421 both alone (IC50 = 11 microM) and in the presence of tetrodotoxin. RH-3421 does not influence the level of free Ca2+ or basal 45Ca2+ uptake in non-depolarized synaptosomes. The results suggest RH-3421 inhibits voltage-sensitive calcium channels in nerve endings.
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Nicholson RA. The actions of abietic acid in mammalian synaptosomal preparations. Biochem Soc Trans 1994; 22:226S. [PMID: 7958288 DOI: 10.1042/bst022226s] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Nicholson RA, Barnard GW, Robbins L, Hankins G. Predicting treatment outcome for incompetent defendants. THE BULLETIN OF THE AMERICAN ACADEMY OF PSYCHIATRY AND THE LAW 1994; 22:367-377. [PMID: 7841508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
This study examined the prediction of outcome in a sample of defendants hospitalized for treatment of incompetency. Defendants' demographic characteristics and scores on 18 scales of the Computer-Assisted Determination of Competency to Proceed instrument (CADCOMP) were used to predict competency restoration and length of stay (LOS). During the period of study, almost 90 percent of the defendants were restored to competency after a mean stay of over 280 days. Demographic characteristics were unrelated to outcome. Several CADCOMP scales, including two scales measuring psycholegal ability and one measuring psychopathology, were correlated with both outcome criteria. Discriminant analysis using the CADCOMP scales accurately classified 76.7 percent of the defendants into short and long stay groups. Although promising, the findings are nevertheless consistent with prior research in suggesting that examiners should exercise caution in providing feedback to the courts concerning competency restoration and the period of time needed for treatment.
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Nicholson RA, Williams MF. Sub-chronic administration of ethanol to mice does not modify the inhibitory effects of dieldrin, abamectin and the dihydropyrazole RH-3421 at their respective sites of action in the nervous system. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C, COMPARATIVE PHARMACOLOGY AND TOXICOLOGY 1993; 105:69-72. [PMID: 7687943 DOI: 10.1016/0742-8413(93)90059-t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
1. The potential influence of sub-chronic ethanol treatment on the ability of three chemical classes of insecticide to interact with their neuronal sites of action has been investigated in mouse brain. 2. Ethanol administration did not influence the inhibitory effects of either the cyclodiene dieldrin or the avermectin abamectin as determined by inhibition of GABA-stimulated chloride uptake. 3. Likewise there was also no discernable change in the sensitivity of sodium channels to inhibition by dihydropyrazole RH-3421 with sub-chronic ethanol treatment as assessed indirectly using a membrane potential assay. 4. The results of this study indicate that short term dietary exposure to ethanol fails to cause functional changes to the primary target sites of cyclodienes, avermectins and dihydropyrazoles in the mammalian central nervous system.
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Poller DN, Hutchings CE, Galea M, Bell JA, Nicholson RA, Elston CW, Blamey RW, Ellis IO. p53 protein expression in human breast carcinoma: relationship to expression of epidermal growth factor receptor, c-erbB-2 protein overexpression, and oestrogen receptor. Br J Cancer 1992; 66:583-8. [PMID: 1355662 PMCID: PMC1977948 DOI: 10.1038/bjc.1992.318] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The expression of p53 protein, oestrogen receptor protein, epidermal growth factor receptor (EGFR) and overexpression of the c-erbB-2 oncoprotein was examined in a series of 149 primary symptomatic breast carcinomas. Expression of p53 was present in 62 of 146 cases (42.5%) of the invasive carcinoma and one of three cases (33.3%) of ductal carcinoma in situ (DCIS) examined. Statistical associations of tumour oestrogen receptor positivity and lack of p53 protein expression, chi 2 = 19.78 (d.f. = 1), P less than 0.001, positive tumour p53 status and poor tumour grade; chi 2 = 14.1 (d.f. = 2), P less than 0.001, EGFR expression chi 2 = 7.07, (d.f. = 1), P less than 0.01 and tumour c-erbB-2 protein overexpression; chi 2 = 4.61 (d.f. = 1), P = 0.032 were identified. Expression of p53 is rare in invasive lobular carcinoma of classical type (8.3% of cases examined) in contrast to other common types of mammary carcinoma. Non-significant trends of p53 protein expression and increased regional tumour recurrence; chi 2 = 3.20 (d.f. = 1), P = 0.074 and also poorer patient survival; chi 2 = 3.76 (d.f. = 1), P = 0.053 were identified. p53 protein expression is a common event in human breast cancer and is present in both DCIS and invasive mammary carcinoma. Abnormal expression of p53 protein is a feature of both in situ and invasive breast carcinoma, implying that the abnormal p53 protein expression may be implicated in the early stages of mammary carcinoma progression.
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Nicholson RA. Laser onychology. Clin Podiatr Med Surg 1992; 9:633-57. [PMID: 1393985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Laser techniques for nail pathology have existed for over a decade. Published reports concerning onychologic techniques and results are growing along with other medical laser literature. In this article, the author has presented techniques with which he and podiatric colleagues at Wenske Laser Center have operational familiarity. Preoperative concerns have been emphasized and potential complications and prevention are discussed. Widely variant results are identified. Laser onychologic procedures are technique intensive. Research is needed, therefore, to identify factors that might lead to technical improvements so that results may be enhanced. Perhaps in the future laser onychology shall exist as a subspecialty to podiatry and dermatology, much as endodontics is to dentistry. It is hoped that this work might contribute in some small way to that development.
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Nicholson RA, McNulty JL. Outcome of hospitalization for defendants found incompetent to stand trial. BEHAVIORAL SCIENCES & THE LAW 1992; 10:371-383. [PMID: 10148855 DOI: 10.1002/bsl.2370100307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study assessed the outcome of hospitalization for incompetent criminal defendants admitted to the forensic unit of a state hospital for treatment during a 4-year period. Findings suggested that the overwhelming majority of the defendants were restored to competency. The defendants also showed significant improvement in overall severity of psychopathology during hospitalization. Further, the duration of hospitalization for these defendants was relatively short. Although these results are promising with regard to treatment of incompetent defendants, predicting the outcome of hospitalization for these defendants was problematic. Prediction of competency restoration was precluded because persistent incompetence was so infrequent. Moreover, multiple regression analyses suggested limited predictive ability with regard to defendants' discharge level of functioning or length of hospitalization. These findings are consistent with the view that examiners should exercise caution in making recommendations to the courts concerning treatability of incompetent defendants.
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Barnard GW, Nicholson RA, Hankins GC, Raisani KK, Patel NR, Gies D, Robbins L. Itemmetric and scale analysis of a new computer-assisted competency assessment instrument (CADCOMP). BEHAVIORAL SCIENCES & THE LAW 1992; 10:419-435. [PMID: 10148840 DOI: 10.1002/bsl.2370100311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Male defendants (n = 99) who had been court ordered to a forensic treatment facility as incompetent to stand trial were tested using the Computer-Assisted Determination of Competency to Proceed (CADCOMP) instrument soon after admission (median days = 15). Shortly thereafter, competency was assessed by a forensic psychiatrist and by a majority decision of three mental health professionals who viewed a videotape of the forensic psychiatrist's interview. From the CADCOMP item pool, 18 scales were constructed on conceptual grounds. Internal consistency analyses revealed that most scales had reasonable item homogeneity and scale reliability. In addition, item and scale analyses, with few exceptions, followed predicted patterns of intercorrelation and association with competency as determined by both criteria. Scales and items measuring serious psychopathology, psycholegal ability, and criminal history demonstrated the strongest associations with competency. These findings suggest that additional research on CADCOMP is warranted. The instrument shows promise for use in forensic research and assessment.
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Gifford AN, Nicholson RA, Pitman RM. The dopamine and 5-hydroxytryptamine content of locust and cockroach salivary neurones. J Exp Biol 1991; 161:405-14. [PMID: 1757773 DOI: 10.1242/jeb.161.1.405] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The salivary glands of the cockroach and locust are innervated primarily from two pairs of motoneurones, designated SN1 and SN2, in the suboesophageal ganglion. Intracellular cobalt fills and subsequent silver intensification were used to reveal the morphology of these cells in both species. Fluorescent microscopy, following treatment of the ganglion with glyoxylic acid, showed that in both species only the SN1 neurones contained catecholamines. A radioenzymatic assay for dopamine, performed on the locust SN1 neurones, confirmed that this catecholamine was present. A radioenzymatic assay for 5-hydroxytryptamine (5-HT), performed on both pairs of salivary neurones in the locust, revealed small quantities of this amine in the SN2 neurones, but no significant amount in the SN1 neurones. In the cockroach, 5-HT was assayed in the SN2 neurones only. In contrast to the locust, however, the 5-HT content of these cells was not significantly above that of control cells taken from other ganglia. These observations demonstrate that only the SN1 neurones are the source of the catecholaminergic fibres investing the locust and cockroach salivary glands. The difference in neurotransmitter content between the SN1 and SN2 neurones suggests that these neurones have separate functions in the control of salivary secretion.
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Kumi CO, Nicholson RA, Law FC. Absorption, degradation and excretion of benzo(a)pyrene in the cricket (Acheta domesticus). Xenobiotica 1991; 21:1357-62. [PMID: 1796612 DOI: 10.3109/00498259109043210] [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: 12/28/2022]
Abstract
1. The absorption, degradation and excretion of 3H-benzo(a)pyrene (3H-BP) was examined in the cricket (Acheta domesticus). 2. After 3H-BP injection, extractable 3H-BP declined in the internal compartment over a 48 period. 3. When 3H-BP was deposited on the surface of the insect it penetrated through the cuticle, as evidenced by decrease in 3H-BP recovered in surface rinses and accumulation of 3H-BP internally. 4. Administration of 3H-BP by topical application or injection resulted in a progressive association of radioactivity with tissue debris and low-level metabolism to highly polar compounds. Both parent compound and highly polar metabolites were detected in excreta. 5. Treatment of insects with piperonyl butoxide decreased accumulation of polar products in excreta after injection of 3H-BP.
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Nicholson RA, Norwood S, Enyart C. Characteristics and outcomes of insanity acquittees in Oklahoma. BEHAVIORAL SCIENCES & THE LAW 1991; 9:487-500. [PMID: 10148823 DOI: 10.1002/bsl.2370090411] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The insanity defense is perhaps the most vigorously debated topic at the interface of the legal and mental health systems. This article addresses the need for empirical evidence by providing data on insanity acquittees and their later outcomes in Oklahoma, a jurisdiction not previously studied. Information was obtained on the demographic, legal, psychiatric, hospitalization, and post-hospitalization characteristics of all 61 defendants acquitted not guilty by reason of insanity (NGRI) and treated on the state forensic unit during a 5-year period. Insanity acquittees had few resources, significant psychopathology, and extensive involvement with the legal and mental health systems prior to the NGRI offense. Follow-up of three groups of discharged patients--those released at an initial court review, those who completed the NGRI treatment program, and those who absconded from the forensic unit--revealed that those who escaped from the unit had significantly more arrests and subsequent legal charges than regularly discharged patients.
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Pocock JM, Nicholson RA, Osborne MP. Effects of colchicine on central and peripheral nerve terminals of the locust Schistocerca gregaria. JOURNAL OF NEUROCYTOLOGY 1990; 19:574-83. [PMID: 2243248 DOI: 10.1007/bf01257245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The treatment of locusts (Schistocerca gregaria) with colchicine leads to various changes in the ultrastructure of both central and peripheral nerve terminals. These changes include a marked reduction in synaptic vesicle density, which is further enhanced following stimulation. There are also increased numbers of coated pits and membraneous cisternae together with enlarged terminal areas and disruption of mitochondrial ultrastructure. The capacity of isolated central nerve terminals (synaptosomes) to take up the radiolabelled transmitter precursor [3H]-choline is enhanced following in vivo treatment of locusts with colchicine, whilst in vitro treatment leads to a reduction in choline uptake. The results are discussed with regard to the postulated effects of colchicine on axoplasmic transport.
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Pocock JM, Osborne MP, Nicholson RA. The effect of in vivo stimulation on the cytology of neuromuscular junctions of locust flight muscles. JOURNAL OF NEUROCYTOLOGY 1990; 19:566-73. [PMID: 2173741 DOI: 10.1007/bf01257244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The ultrastructure of neuromuscular junctions in dorsoventral (tergosternal) flight muscle no. 113 and dorsolongitudinal flight muscle no. 112 of the locust Schistocerca gregaria is described. Following in vivo stimulation by enforced flight, morphological and statistical analyses reveal cytological changes at these junctions suggestive of vesicular release of neurotransmitter and membrane recycling. Flight periods from 30 min to 3 h produced a progressive decrease in the density of terminal synaptic vesicles, an increase in terminal surface area and circumference, increases in the occurrence of membranous cisternae, increases in mitochondrial numbers, and increases in the frequency of coated pits.
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Whitton PS, Nicholson RA, Strang RH. Effect of taurine on neurotransmitter release from insect synaptosomes. J Neurochem 1988; 51:1356-60. [PMID: 2902194 DOI: 10.1111/j.1471-4159.1988.tb01097.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of taurine on the release of [3H]acetylcholine ([3H]ACH) and [3H]gamma-aminobutyric acid ([3H]GABA) from preloaded locust synaptosomes has been studied. Veratridine (100 microM) and K+ (100 mM) both evoked [3H]ACh release and this was reduced in a concentration-dependent manner by taurine (5, 10, and 20 mM). In contrast to this, veratridine induced no observable release of [3H]GABA, and the response to K+ was slight. In the presence of taurine, however, a concentration-dependent enhancement of [3H]GABA release was observed. Since nipecotic acid (1 mM), an inhibitor of neuronal GABA uptake, also revealed [3H]GABA release induced by veratridine, it is suggested that both this effect and that of taurine are due to prevention of GABA reuptake. These results suggest that taurine may act as a neuromodulator in insects.
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Whitton PS, Nicholson RA, Strang RH. Effect of taurine on calcium accumulation in resting and depolarised insect synaptosomes. J Neurochem 1988; 50:1743-6. [PMID: 3373212 DOI: 10.1111/j.1471-4159.1988.tb02473.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effect of taurine (2-aminoethanesulphonic acid) on 45Ca2+ accumulation in resting and depolarised synaptosomes obtained from the locust Schistocerca americana gregaria was studied. Taurine reduced 45Ca2+ accumulation in resting synaptosomes, and this effect was more pronounced when synaptosomes were depolarised with either high [K+] or veratridine. Veratridine-induced 45Ca2+ accumulation was not affected by either gamma-aminobutyric acid or leucine, but was reduced by both verapamil and tetrodotoxin.
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Nicholson RA. Characteristics associated with change in the legal status of involuntary psychiatric patients. HOSPITAL & COMMUNITY PSYCHIATRY 1988; 39:424-9. [PMID: 3371910 DOI: 10.1176/ps.39.4.424] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Patients initially admitted to a state hospital under an emergency commitment procedure were studied to identify the variables associated with their later change to voluntary status, release, or judicial commitment, and to compare the hospitalization and outcome patterns of voluntary and committed patients. Compared with committed or voluntary patients, released patients were younger and better educated; were more likely to be employed at admission, to contribute to family income, and to have had previous outpatient treatment; and were less likely to have serious organic or psychotic disorders or to receive government assistance. Voluntary patients were hospitalized twice as long as committed patients and were less frequently considered to have received maximum benefits from hospitalization. In view of the association between voluntary status and longer hospitalization, periodic review may be needed to safeguard these patients from unnecessary confinement.
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