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Biomedical subjects

C Hyde

Publications and source records attributed to C Hyde.

At least 19 recordsLinked to original sources
PubMed1998

Cerebral microembolism in patients with retinal ischemia.

BACKGROUND AND PURPOSE: We investigated the frequency of cerebral microembolism detected by transcranial Doppler ultrasonography in patients with clinical evidence of retinal ischemia, including transient monocular blindness, central and branch retinal artery infarction, and ischemic oculopathy, and assessed its correlation with carotid artery stenosis. METHODS: Records of 331 consecutive patients examined during a 47-month period at the Neurovascular Laboratory were reviewed. Of the original 453 intracranial arteries, 186 middle cerebral arteries (MCAs) satisfied qualifying criteria that excluded patients with cardiac embolic sources. Forty-five MCAs ipsilateral to the symptomatic eye constituted the study group. The control group consisted of 141 asymptomatic MCAs. Microembolus detection studies were performed on transcranial Doppler instruments equipped with special software, and the degree of carotid artery stenosis was measured by cerebral or MR angiography or by color duplex studies. RESULTS: Microembolism was detected in 40.0% of study MCAs and 9.2% of controls (P < 0.001). In the study group, microembolic signals were detected in 61.9% of MCAs tested within a week of symptom onset and 20.8% of those tested afterward (P < 0.001). Severe (> or = 70%) carotid stenosis or occlusion was more frequent in the study group (P < 0.001). Microembolic signals were detected in 25.3% and 11.2%, respectively, of MCAs distal to carotid arteries with 70% to 100% and 0% to 69% stenosis (P = 0.013). CONCLUSIONS: In patients without cardiac embolic sources, cerebral microembolism is frequently present on the side of retinal ischemia, particularly during the week after onset of symptoms. It is often associated with severe stenosis or occlusion of the ipsilateral carotid artery.

Adult↗
PubMed1997

Cardiac rhythmicities and attention in young children.

This study examined the changes in three cardiac rhythmicities (angiotensin-renin vasomotor [ARV], Traube-Hering-Meyer [THM], and respiratory sinus arrhythmia [RSA]) during prolonged attention in preschool children. Electrocardiogram data were collected from children during resting baseline and a 5-min attention condition at ages 3, 4, and 5 years in a longitudinal study. The ARV and THM rhythmicities decreased during prolonged attention for most participants. The RSA rhythmicity did not change consistently. The results were replicated at all three ages. The ARV and THM effect sizes were large and moderate, respectively. Only the ARV decrease correlated with duration of attention.

Arrhythmia, Sinus↗
PubMed1997

Cerebral microembolism and early recurrent cerebral or retinal ischemic events.

BACKGROUND AND PURPOSE: We investigated whether cerebral microembolism as detected by transcranial Doppler ultrasonography (TCD) identifies patients at an increased risk for early, recurrent cerebral or retinal ischemic events. METHODS: Records of consecutive patients examined during a 40-month period in the Neurovascular Laboratory were reviewed for the presence of cerebral microembolism. Of the original 302 patients, 229 with 310 arteries met inclusionary criteria. Follow-up information was obtained from the laboratory's database as well as the hospital records. Microembolus detection studies were performed on TC-2000 or TC-2020 instruments equipped with special software, and criteria established a priori were used for microembolus selection. TCD testing was performed a median interval of 9 days after the initial symptoms of cerebral ischemia. Severity of arterial stenosis was determined by cerebral angiography or noninvasive methods. RESULTS: Microembolic signals were detected more frequently in symptomatic (40/140; 28.6%) than asymptomatic (21/170; 12.4%) arteries (P < .001). Ten recurrent ischemic events occurred during a median follow-up of 8 days after TCD examination, all in the territories of symptomatic arteries. Nine events occurred in the territories of microembolic signal positive arteries (9/61; 14.8%) and one in the territory of a microembolic signal-negative artery (1/249; 0.4%) (P < .00). No association was detected in the subgroup with known cardiac lesions. Microembolic signals were more frequent in arteries with lesions causing 70% or more stenosis or occlusion (26/99; 26.3%) than in those with a degree of stenosis less than 70% (17/126; 13.5%) (P = .016). CONCLUSIONS: In this retrospective study, microembolic signals were more common in the territories of symptomatic arteries and particularly those with severely stenotic lesions. During a short follow-up, recurrent ischemic events were more common along the territories of arteries with TCD-detected microembolism and previous symptoms of cerebral or retinal ischemia.

Brain↗
PubMed1996

Emphysematous cystitis and pyelitis in a diabetic renal transplant recipient.

Emphysematous cystitis is a rare complication of urinary tract infection. Patients with diabetes mellitus, neurogenic bladder, bladder outlet obstruction, and recurrent urinary tract infection are at increased risk for the disease. We present a case of emphysematous cystitis and pyelitis in a diabetic renal transplant recipient. He was treated with antibiotics alone with complete clinical and radiologic resolution. The clinical course was benign, as described in most patients. The prognosis of emphysematous cystitis is good after early diagnosis and prompt treatment with appropriate antibiotics, blood glucose control, and adequate urinary drainage.

Cystitis↗
PubMed1996

Effect of time and cerebrovascular symptoms of the prevalence of microembolic signals in patients with cervical carotid stenosis.

BACKGROUND AND PURPOSE: High-intensity transient signals (HITS) detect ed by transcranial Doppler ultrasonography correspond to microemboli in intracranial arteries. The aim of this study was to determine the time course of cerebral microembolism in patients with symptomatic internal carotid artery stenosis and to assess its relation to specific symptoms of cerebral ischemia. METHODS: On the basis of criteria established a priori, 69 middle cerebral arteries were selected from a series of consecutive studies obtained at our neurovascular laboratory. All patients had radiological evidence of cervical internal carotid artery disease and had corresponding symptoms. A TC-2000 instrument equipped with special software for microembolus detection was used. Accepted signals were unidirectional from baseline, had a chirping sound, were 9 dB higher than the surrounding blood, and lasted 25 milliseconds or more. RESULTS: HITS were identified in 20 of 69 (29%) arteries. The median interval between onset of symptoms and time of testing was 4 days for HITS-positive arteries and 12 days for those that were HITS negative (P=.0046). Fourteen of 32 (44%) arteries with transient ischemic attacks and 6 of 37 (16%) arteries with cerebral infarction were HITS positive (P=.012). CONCLUSIONS: In patients with symptomatic carotid stenosis, HITS are detected more frequently when patients are tested soon after symptoms of cerebral ischemia. HITS are also more prevalent in the territories of arteries with transient ischemic attacks rather than cerebral infarction. These findings may have diagnostic and therapeutic implications.

Adult↗
PubMed1995

Some clinical and methodological implications of a treatment outcome study of sexually abused children.

The clinical implications of the results of a treatment outcome study are presented for 47 sexually abused children and adolescents attending a specialist psychiatric facility. The children and their nonabusing parents or caregivers were randomly assigned to contrasting treatment programs. The treatment focused on family members allocating blame for the abuse appropriately, optimizing family relationships, and dealing with causes and effects of the abuse. Clinicians rated the children and the mothers on 12 family treatment aims before and after treatment; on the same occasion additional standardized measures were used to assess behavior and mental state of the children and mental state of the mothers. On the standardized measures mothers made more significant progress than their children in the year of treatment, but there were no effects of type of treatment on the progress made by mothers or children. By contrast, clinical ratings suggested that those following the additional group work made better progress than those following the treatment without group work. The implications of these results for the clinical programs are discussed.

Adolescent↗
PubMed1995

The type and quality of randomized controlled trials (RCTs) published in UK public health journals.

BACKGROUND: Randomized controlled trials (RCTs) are increasingly being used to evaluate the effectiveness of health care interventions. Systematic reviews of RCTs form the basis of the Cochrane Collaboration, which aims to synthesize all RCTs concerned with the provision of health care. This paper reports the quantity and methodological quality of RCTs published in five UK public health journals, which were searched as part of a planned register of RCTs in public health. METHODS: Five journals were hand searched: The International Journal of Epidemiology, Health Trends, Journal of Public Health Medicine, Public Health and The Journal of Epidemiology and Community Health. All RCTs were identified and their methodological characteristics reviewed. RESULTS: Ninety-one trials were identified from the five journals. A wide variety of topics were covered, the most common being prevention strategies )46 percent of the trials). Although the actual number of reports of RCTs published increased over time, there was no detectable improvement in the quality of reports. The aspect of bias most well controlled was control of bias at entry (randomization), in 83 (91 per cent) of trials. However, even in these trials details about the process of randomization were poor. CONCLUSION: These trials will form the basis of a register of RCTs in public health. The diversity of topics covered illustrates the broad-based nature of public health. For this reason, many other RCTs relevant to the practice of public health are likely to be found in non-public health journals.

Humans↗
PubMed1994

A motif in human histidyl-tRNA synthetase which is shared among several aminoacyl-tRNA synthetases is a coiled-coil that is essential for enzymatic activity and contains the major autoantigenic epitope.

In myositis, disease-specific autoantibodies may be directed against an aminoacyl-tRNA synthetase, usually histidyl-tRNA synthetase. To explore the basis for this phenomenon, we have made recombinant histidyl-tRNA synthetase in the baculovirus system. It was enzymatically active and recognized by human autoantibodies. A truncated protein lacking the first 60 amino acids was inactive as an antigen and as an enzyme. This region is within the first two exons, is predicted to have a coiled-coil configuration, and is found in some other synthetases but not in Escherichia coli or yeast histidyl-tRNA synthetase. Circular dichroism showed that the peptides from this region (amino acids 1-60 and 1-47) have the predicted high alpha-helical content, but smaller fragments (1-30, 14-45, and 31-60) do not. The peptides with a high alpha-helical content could inhibit autoantibodies almost completely, whereas the smaller peptides were unable to do so. The amino acid sequence of this coiled-coil domain in human histidyl-tRNA synthetase resembles the sequence of the extended this coiled-coil arm near the NH2 terminus of bacterial seryl-tRNA synthetase as well as similar regions in some eukaryotic aminoacyl-tRNA synthetases, raising the possibility that this domain serves a similar tRNA-stabilizing role and has been preserved from a common ancestor.

Amino Acid Sequence↗
PubMed1994

Clinical correlates of high-intensity transient signals detected on transcranial Doppler sonography in patients with cerebrovascular disease.

BACKGROUND AND PURPOSE: High-intensity transient signals detected by transcranial Doppler sonography have been associated with particulate cerebral emboli. Their clinical correlates are poorly understood. This study was undertaken to assess their relation to cerebral ischemia and to determine whether the severity of cerebral arterial stenosis has an impact on their occurrence. METHODS: We studied 96 arteries in 75 consecutive patients with extracranial or intracranial arterial lesions or potential cardiac sources of cerebral embolism. Sixty patients had histories of cerebral or retinal transient ischemic attacks or infarcts, and 15 were asymptomatic. The diagnosis of ischemia was based on the clinical presentation and was supported by extensive laboratory testing. A transcranial Doppler sonography unit equipped with special software for emboli detection was used. Signals were selected based on criteria established a priori. RESULTS: Signals were detected in the territories of 28.3% of symptomatic and 11.6% of asymptomatic arteries. The difference was significant (P = .045). When patients with suspected cardiac embolic sources were excluded, the difference between symptomatic (27.9%) and asymptomatic (2.9%) arteries remained significant (P = .003), and signals were more frequent distal to arteries with more than 50% area stenosis (23.5%) than arteries with stenoses equal to or less than 50% (3.7%) (P = .028). In patients with only extracranial internal carotid artery stenoses, the difference between these degrees of stenosis remained significant (P = .043). CONCLUSIONS: We conclude that high-intensity transient signals are significantly more common in the territories of symptomatic arteries and distal to lesions causing more than 50% stenosis. These findings may have diagnostic and therapeutic applications.

Adult↗
PubMed1991

Adrenal hemangioma: an unusual adrenal mass delineated with magnetic resonance imaging.

Adrenal hemangioma should be included in the differential diagnosis of any large calcified adrenal mass. We report to our knowledge the eighth surgically removed lesion and describe its appearance on magnetic resonance imaging. This imaging includes features seen in hemangiomas elsewhere, in particular a heterogeneous mass with enhancing peripheral high intensity foci on T1 images.

Adrenal Gland Neoplasms↗
PubMed1990

Correlation of transcranial Doppler and noninvasive tests with angiography in the evaluation of extracranial carotid disease.

To evaluate the usefulness of transcranial Doppler sonography in determining severity of extracranial carotid disease, we compared transcranial Doppler, ocular pneumoplethysmography, Doppler spectral analysis, and duplex scanning data to information derived from cerebral angiography. Fifty-one consecutive patients with unilateral extracranial internal carotid artery stenosis or occlusion were selected. Transcranial Doppler indexes included the peak systolic flow velocity in the middle cerebral artery ipsilateral to the stenosed internal carotid artery (iMCAFV), the difference between the peak systolic flow velocities in the middle cerebral artery ipsilateral and contralateral to the stenosed internal carotid artery (dMCAFV), and the peak systolic flow velocity in the anterior cerebral artery contralateral to the stenosed internal carotid artery (cACAFV). The minimal residual lumen determined angiographically was used as the index of internal carotid artery stenosis. Linear regression analysis with minimal residual lumen as the dependent variable and transcranial Doppler and noninvasive tests as independent variables showed the following correlation coefficients: (1) dMCAFV and cACAFV, R2 = 0.3170; (2) ocular pneumoplethysmography, R2 = 0.4798; (3) dMCAFV, cACAFV, delta ocular pneumoplethysmography, duplex scanning, and spectral analysis R2 = 0.6382; (4) ocular pneumoplethysmography, duplex scanning, and spectral analysis, R2 = 0.6491; (5) iMCAFV, no association. These results were supported by sensitivity and specificity as well as bivariate analysis. We conclude that transcranial Doppler did not significantly add to the information obtained by our noninvasive battery of tests in the evaluation of unilateral extracranial carotid disease.

Blood Flow Velocity↗
PubMed1987

The evaluation of a hostel ward. A controlled study using modified cost-benefit analysis.

A controlled modified cost-benefit evaluation of a hostel ward caring for new long-stay patients is described and results are presented for the first two years. In some respects the residents of the hostel ward had fewer psychotic impairments than those remaining on the wards of the district general hospital, mainly because the latter seem to continue to acquire such defects, while the former have remained relatively unchanged. The hostel ward residents also develop superior domestic skills, use more facilities in the community, and are more likely to be engaged in constructive activities than controls. These advantages were not purchased at a price, since the cost of providing this form of care for these patients has cost less than care provided by the district general hospital.

Adolescent↗
PubMed1985

Douglas House: a new type of hostel ward for chronic psychotic patients.

A new type of hostel ward is described in which domestic activities take the place of attendance at a day centre or industrial workshop. Residents no longer depend on the institution for meals, cleaning, or social activities. The programme is resident-orientated, and individual treatment plans are designed and effected using a points system. The emphasis of group activities is on communication and living skills. The hostel ward is able to care for our most disabled patients who are thought to need 24-hour nursing care.

Activities of Daily Living↗
PubMed1983

Labelling and drug effects in the treatment of neurotic affective disorders: an experimental investigation.

This study investigates the effects of assigned diagnostic labels, with their accompanying predictions of therapeutic response, and prescribed psychotropic drugs. It was thought that such 'labelling' effects might be important in ambiguous situations, such as neurotic anxiety-depressive states, where diagnoses of 'reactive depression' or 'anxiety state' might justifiably be made and treatment with either diazepam or nortriptyline legitimately given. The depression label and its concomitant two-weekly prediction of improvement with antidepressants produced a set towards slower response with higher self-report depression. Nortriptyline produced significantly more improvement in self-report depression than diazepam in the first 2 weeks of treatment. No significant interaction effects were detected between diagnosis or drug. One month after the initial diagnostic evaluation there were no significant effects from either diagnostic label or drug.

Adolescent↗