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J Currie

Publications and source records attributed to J Currie.

At least 37 records · Page 2Linked to original sources
PubMed1997

Inv(10)(p11.2q21.2), a variant chromosome.

We present 33 families in which a pericentric inversion of chromosome 10 is segregating. In addition, we summarise the data on 32 families in which an apparently identical inv(10) has been reported in the literature. Ascertainment was through prenatal diagnosis or with a normal phenotype in 21/33 families. In the other 12 families, probands were ascertained through a wide variety of referral reasons but in all but one case (a stillbirth), studies of the family showed that the reason for referral was unrelated to the chromosome abnormality. There has been, to our knowledge, no recorded instance of a recombinant chromosome 10 arising from this inversion and no excess of infertility or spontaneous abortion among carriers of either sex. We propose that inv(10)(p11.2q21.2) can be regarded as a variant analogous to the pericentric inversion of chromosome 2(p11q13). We conclude that prenatal chromosome analysis is not justified for inv(10) carriers. In addition, family investigation of carrier status is not warranted in view of the unnecessary concern this may cause parents and other family members.

Abortion, Spontaneous↗
PubMed1997

Object-based visual attention in luminance increment detection?

A cued reaction time task was used to test the hypothesis that there is an 'object-based' component to shifts of attention mediating the detection of luminance increment targets. The test stimulus consisted of two intersecting triangles forming a 'Star of David'. In two experiments, the cue was a brief brightening of one triangle. The target (a bright green dot) appeared on one of the triangles after a delay of 100, 200 or 500 msec. In one experiment, the target was more likely to appear on the cued triangle. In a second experiment, there was no contingency between cue and target. In both cases, reaction times to targets which appeared outside (but not inside) the cued triangle were more than 10 msec longer than other targets, but only at the shorter cue-target delays. This indicates that the attentional system which regulates luminance increment detection cannot select the cued triangle. It appears that the attentional spotlight can be briefly deformed into a triangular shape, and that it is the rapid, fast-decaying and reflexive exogenous system, rather than the slower acting, persistent and voluntary endogenous system, that mediates this effect. A third experiment using a central, symbolic cue showed no significant cue-validity effects, indicating no contribution from the endogenous system. It is concluded that tasks requiring only stimulus detection cannot unequivocally discriminate between spatial and object-based components of attention.

Adolescent↗
PubMed1996

Cognitive deficits in Machado-Joseph disease.

Cognitive function was examined in 6 patients with genetically confirmed Machado-Joseph disease (MJD) and 15 age- and ethnically matched controls using a series of subtests from the Cambridge Neuropsychological Test Automated Battery (CANTAB), a touch screen-based testing system previously validated in a number of movement and neurodegenerative disorders. The MJD patients had deficits in visual attentional function that were characterized by a slowing of the processing of visual information when task demands were high and an inability to shift attention to previously irrelevant stimulus dimensions to discriminate between complex stimuli. Tests of learning and visual memory were normal. These results demonstrate that specific cognitive deficits occur in patients with MJD, independent of motor dysfunction, and these deficits may reflect disruption to frontosubcortical pathways.

Adult↗
PubMed1996

Combination chemotherapy with hydroxyurea, dacarbazine (DTIC), and etoposide in the treatment of uterine leiomyosarcoma: a Gynecologic Oncology Group study.

Advanced or recurrent uterine leiomyosarcomas have traditionally been resistant to most chemotherapeutic regimens. Preliminary reports suggested the combination of hydroxyurea, dacarbazine (DTIC), and etoposide (VP-16) was sufficiently effective to warrant larger trials. In a Phase II trial undertaken by the Gynecologic Oncology Group, 39 patients with advanced or recurrent leiomyosarcoma were treated with 2 g of hydroxyurea, 700 mg/m2 of DTIC, and 300 mg/m2 of VP-16 in divided doses every 4 weeks. Thirty-eight patients were evaluable for response. Two patients experienced complete responses and five had partial responses for a total objective response rate of 18.4% (95% confidence interval: 7.7-34.3%). In general, therapy was well tolerated with moderate toxicity. Six of the seven responders had disease outside the pelvis. The combination of hydroxyurea, DTIC, and VP-16 exhibits moderate activity against uterine leiomyosarcoma.

Adult↗
PubMed1996

Deficits in the endogenous redirection of covert visual attention in chronic schizophrenia.

In patients with schizophrenia, abnormal performance on the antisaccade task suggests that for overt attentional shifts, there is difficulty with the endogenous modes have opposite goals. We examined whether patients with schizophrenia also have difficulty with the endogenous control of exogenous orienting when endogenous and exogenous control of exogenous orienting for covert shifts of attention. Fifteen medicated patients with chronic schizophrenia and 15 matched controls performed two versions of the covert orienting of attention task (COVAT). On one COVAT, targets appeared at the cued location (TAC) on all trials. On the second COVAT, targets appeared at the contralateral location to the cue (TCC) on all trials. Reaction time (RT) for TAC and TCC trials was equal in the control group. However, for the schizophrenia group, RT for TCC trials was significantly slower than RT for TAC trials. This indicates that patients with schizophrenia were unable to inhibit the orienting of attention to peripheral cues even when they knew that targets would never appear at the same location as the cue. These results suggest that patients with chronic schizophrenia have difficulty utilizing the endogenous strategies to inhibit exogenous covert attentional shifts.

Adult↗
PubMed1996

Naive human alpha beta T cells respond to membrane-associated components of malaria-infected erythrocytes by proliferation and production of interferon-gamma.

Crude extracts of Plasmodium falciparum schizont-infected erythrocytes (PfSE) induce polyclonal activation of peripheral blood T lymphocytes from naive (malaria unexposed) humans. We demonstrate that the active component of PfSE is membrane bound, soluble in sodium dodecyl sulphate (SDS) and partially heat stable, but distinct from the tumour necrosis factor (TNF)-inducing, exoantigen-like activity of schizont extracts. Malaria pigment induces little or no T-cell activation. The responding cells are predominately CD4+, CD45RO+, T-cell receptor (TCR) alpha beta+. Contrary to previous reports, expansion of the TCR gamma delta+ subset was observed in cells from only one of eight donors. Proliferating cells secrete interferon-gamma (IFN-gamma) and release large amounts of soluble interleukin-2R (sIL-2R) into the culture supernatant but produce no detectable interleukin-4 (IL-4), a phenotype typical of the T-helper (Th)1 subset of CD4+ T cells. We propose that these activated T cells may initiate the inflammatory response to malaria infection in non-immunes and may contribute to the pathology of the disease.

Animals↗
PubMed1995

Positive and negative symptoms in neuroleptic-free psychotic inpatients.

Andreasen's scales for the assessment of positive (SAPS) and negative (SANS) symptoms and the Brief Psychiatric Rating Scale (BPRS) were administered to a group of 70 neuroleptic-free psychotic inpatients. Individual ratings from the SAPS and SANS, together with the 18-item BPRS, were examined to identify clusters of symptoms. The findings, consistent with our previous studies using medicated patients, did not support a simple positive-negative dichotomy. Independent syndromes representing negative symptoms and thought disorder were apparent, although within the negative syndrome there were three related sub-syndromes of flat affect, alogia and social dysfunctions. Hallucinations and delusions did not form a homogeneous group of symptoms. Paranoia emerged as a distinct syndrome, and the remaining symptoms could be subdivided into hallucinations, grandiose delusions, and 'loss of boundary' delusions (e.g., thought broadcasting, mind reading). These syndromes, with the exception of loss of boundary delusions, which consisted of SAPS delusions alone, correspond to syndromes of psychosis identified by Lorr and his colleagues thirty years ago. It is concluded that the currently popular 'three syndrome' model does not adequately represent the diversity of psychotic symptoms.

Adult↗
PubMed1995

Presentation of acute Wernicke's encephalopathy and treatment with thiamine.

Thirty two cases of acute Wernicke's encephalopathy were observed in a period of 33 months, and prior to the mandatory thiamine enrichment of Australian bread-making flour in 1991. These cases were carefully assessed by multiple tests at specified intervals prior to, and following thiamine administration until discharge from hospital. Structured scoring of neurological signs and symptoms, CT scans, psychometry, nutritional measurements, and liver biopsies were performed. There was variation in the presentation and severity of clinical signs and symptoms and in response to treatment. All patients had alcohol-related liver disease, and the results indicated that fatty liver was important in presentation and in response to treatment with thiamine. Other forms of alcohol related brain damage were present in these patients, most of whom were in the 4th or 5th decade of life and had been drinking beer to excess for more than 20 years.

Alcoholic Intoxication↗
PubMed1995

An attentional grasp reflex in patients with Alzheimer's disease.

Motor and visual grasp reflexes often occur as part of the symptomatology of Alzheimer's disease (AD). Similar grasp reflexes may also be associated with the impaired performance of AD patients on tasks which require direction of visual attention without eye movements. The covert orienting of visual attention task (COVAT) requires subjects to keep their eyes fixed on a central point and manually respond to the appearance of a peripheral target in one of two locations in the left or right visual field. Before the target appears, a cue is presented at either the target location or the contralateral location to the target, although the nature of the cue is not known until the target appears. We hypothesised that the attentional grasp reflex would become evident in patients with AD when attentional shifts away from the cue were required but there was no target for the shift present. Twelve patients who met the clinical criteria for AD and 12 age and education matched controls were administered three COVAT conditions in which the target appeared at the cued location with either an 80, 50 or 20% probability. For the 80 and 50% probability conditions. RTs for targets at the cued location were significantly faster than RTs for targets contralateral to the cue in both AD subjects and controls indicating that AD subjects were able to disengage attention when there was a target for the attentional shift. For the 20% probability condition, control subjects showed significantly faster RTs for targets appearing contralateral to the cue than for targets at the cued location indicating that when they expected the target to appear in the opposite visual field to the cue, they could initiate the shift of attention before the target appeared. However, AD subjects continued to show significantly faster RTs for targets at the cued location than for targets appearing contralateral to the cue, despite the high probability that targets would not occur at the cued location. This suggests that the covert redirection of attention away from a peripheral visual cue could not be initiated until the contralateral target appeared. Taken together these results suggest an attentional grap reflex in patients with AD.

Aged↗
PubMed1995

Asymmetries in the covert orienting of visual spatial attention in schizophrenia.

The presence of attentional asymmetries in patients with schizophrenia was investigated with particular emphasis on the effects of stage of disease, medication status and clinical symptom severity. A modified version of Posner's covert orienting of visual attention task (COVAT) which included both spatial and non-spatial cues was administered to six volunteer samples of subjects which consisted of (i) 15 unmedicated and acutely psychotic male subjects with schizophrenia, (ii) 15 male subjects with schizophrenia who had been receiving medication for 14-21 days, (iii) 10 chronic male schizophrenic subjects who had been receiving medication for at least two years, (iv) 10 acutely psychotic male subjects with non-schizophrenic psychoses, (v) 15 subjects with unilateral brain frontal lobe (n = 6) or parietal lobe (n = 9) lesions, (vi) and 15 male control subjects. Measures of saccadic and pursuit eye movements were also obtained from unmedicated and recently medicated subjects with schizophrenia. COVAT attentional asymmetries were present in unmedicated subjects with schizophrenia for the 150 msec stimulus onset asynchrony (SOA). These asymmetries arose because reaction times (RTs) to right visual field targets were significantly slower than RTs to left visual field targets when targets followed invalid spatial or non-spatial cues. These asymmetries were qualitatively similar to those found in the patients with unilateral parietal lobe lesions. Attentional asymmetries partially resolved with brief periods of medication and completely resolved with long periods of medication. No asymmetries were found in controls nor in unmedicated subjects without schizophrenia. No asymmetries of ocular motor function were found. In schizophrenia, attentional asymmetries may reflect a deficit in the disengagement of visual attention from the right visual field and appear to be a stage marker for the disease. However this attentional deficit is dynamic and may reflect disruption to the neurocognitive network controlling attention at the level of the anterior cingulate cortex.

Adolescent↗
PubMed1995

Asymmetries in the covert orienting of visual spatial attention to spatial and non-spatial cues in Alzheimer's disease.

The ability to direct covert visual spatial attention to the left (LVF) and right visual field (RVF) was examined in 15 patients with mild to moderate Alzheimer's disease and 15 age- and education-matched controls using the covert orienting of visual spatial attention task (COVAT) modified to include both spatial and non-spatial cues. Subjects responded with a button press when they detected a target at a location 8 degrees to either the left or right of fixation. On 70% of trials a spatial cue was flashed at the target location before the target appeared. On 15% of trials the spatial cue was flashed at the location contralateral to where it would appear and on the remaining 15% of trials non-spatial diffuse cue preceded targets. The cue to target interval (CTI) varied between 150 and 550 ms. Mean reaction times for each cuetype in the RVF and LVF were calculated. Compared with controls, the percentage of trials excluded because of very slow reaction times was significantly greater in the Alzheimer's disease group for the 550 ms CTI. Analysis of the symmetry of reaction times to LVF and RVF targets for the 150 ms CTI enabled us to classify Alzheimer's disease subjects into three subgroups based on the hemifield of abnormally slow attentional biases. The first subgroup showed a significant slowing of reaction time to all LVF targets, the second showed a significant slowing of reaction time to all RVF targets and the third showed a significant slowing of reaction time to both LVF and RVF targets. Patients with Alzheimer's disease who showed an abnormal attentional bias performed significantly better on neuropsychological tests of memory, language and executive function than Alzheimer's disease patients with no attentional bias. Eight of the Alzheimer's disease subjects were assessed serially on at least six occasions over a 12-month period. The initial classification of abnormal attentional bias or no attentional bias was reliable for seven Alzheimer's disease subjects. One Alzheimer's disease subject, initially classified as having a slowed rightward attentional bias, in subsequent testing over the 12-month period was more consistent with symmetrical COVAT performance. Control subjects showed no attentional biases over the 12-month period and the magnitude of asymmetric attentional slowing over the 12-month period was significantly more variable in individual Alzheimer's disease subjects than in controls. The presence of subgroups of patients with Alzheimer's disease with qualitatively different COVAT performance indicates a large between-subject variability in attentional deficits in Alzheimer's disease. The presence of asymmetric attentional slowing and milder neuropsychological deficits in a subgroup of patients with Alzheimer's disease suggests that in these patients there is functional impairment of attentional areas in only one hemisphere rather than an asymmetric impairment of both hemispheres and that the neurodegenerative disease process may have been less advanced or in an earlier stage than that present in Alzheimer's disease patients with symmetric attentional performance and bilateral COVAT impairment. The preservation of asymmetric attentional slowing over time, together with the increased intra-subject variability in the magnitude of these asymmetries, suggests that asymmetrical COVAT performance represents a reliable reflection of underlying hemispheric function in Alzheimer's disease, although designation of asymmetrical attentional biases should be made on the basis of two or more sequential testing sessions.

Aged↗
PubMed1995

Anaesthesia for a child with centronuclear myopathy.

Centronuclear myopathy (CNM) is an inherited condition involving most muscle fibres in all the body mass, first described in 1966, which has a varying spectrum of presentations. Until recently it had not been associated with an increased risk of malignant hyperpyrexia. A seven-year-old male with CNM was admitted to our hospital for elective surgery. High dose propofol anaesthesia was used, supplemented with N2O/O2 from a new anaesthesia machine. The operation was successful with uncomplicated anaesthesia and recovery.

Anesthesia, General↗
PubMed1995

Abnormalities of visual spatial attention in HIV infection and the HIV-associated dementia complex.

Covert orienting of visuospatial attention (COVAT) was examined in 88 homosexual or bisexual men: 12 with mild HIV-associated dementia complex (ADC), 30 neurologically intact with AIDS (NI-AIDS), 23 asymptomatic HIV+ (HIV+ASX), and 23 HIV-negative control subjects. In mild ADC, COVAT was normal for spatial but impaired for nonspatial cues; 17% of NI-AIDS and HIV+ASX subjects had similar COVAT impairment patterns and also showed cognitive deficits. HIV+ subjects with normal COVAT showed normal cognitive performance. Impairment of nonspatial attentional processing in the ADC subjects and subgroups of the neurologically intact HIV+ subjects may reflect early subcortical dysfunction caused by HIV infection. COVAT assessment may be sensitive for detection of early subclinical neurological impairment in HIV infection.

AIDS Dementia Complex↗
PubMed1994

Neuropsychological characterization of the AIDS dementia complex and rationalization of a test battery.

OBJECTIVE: To define the neuropsychological deficits present in mild human immunodeficiency virus type 1 (HIV-1) associated with the acquired immunodeficiency syndrome (AIDS) dementia complex (ADC) and to develop a rational neuropsychological test battery for its diagnosis. DESIGN: Survey. SETTING: Subjects were recruited from large metropolitan hospital outpatient clinics and were all living independently in the general community. PATIENTS: Three volunteer samples of homosexual-bisexual men: (1) 15 patients who met clinical and research criteria for mild ADC; (2) 27 HIV-seronegative (HIV-) controls; and (3) 17 patients with AIDS who were neurologically intact (NI-AIDS) who were matched with the ADC subjects by CD4 lymphocyte counts for severity of systemic HIV disease. MAIN OUTCOME MEASURES: Neuropsychological test performance; z score comparisons were made with the HIV-control group using 2.25-SD cutoffs for abnormality. RESULTS: Compared with NI-AIDS subjects, performance of patients with mild ADC was markedly worse in the cognitive areas of executive function, memory, and complex attention but not in affect or the cognitive areas of simple motor function, orientation, language, or visuospatial construction. Within the areas of executive function, memory, and complex attention, all of the HIV-controls and 95% of the NI-AIDS subjects had impaired test performance in a maximum of one area only. In marked contrast, 14 (93%) of the 15 patients with mild ADC had abnormal test performances in all three of these cognitive areas. Using a criterion of abnormal performance in at least two of the cognitive areas of executive function, memory, and complex attention, all patients with mild ADC could be differentiated from HIV-controls with 100% sensitivity and specificity and from NI-AIDS subjects matched for disease severity by CD4 lymphocyte count with 100% sensitivity and 94% specificity, which increased to 100% with the requirement of impairment in all three cognitive areas. CONCLUSIONS: If time constraints or patient compliance limit neuropsychometric testing, examination to detect mild ADC first should be directed to the areas of executive function, memory, and complex attention. This pattern of neuropsychological deficits in patients with mild ADC is suggestive of subcortical dementia.

AIDS Dementia Complex↗