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Biomedical subjects

E M Martin

Publications and source records attributed to E M Martin.

At least 19 recordsLinked to original sources
PubMed1992

Differential validity of psychometric tests in dementia of the Alzheimer type.

Forty-nine patients with a clinical diagnosis of probable dementia of the Alzheimer type underwent an extensive test battery designed to evaluate cognitive deficits according to NINCDS/ADRDA criteria. All patients demonstrated signs of impairment on this test battery. One day later, they were administered a second test battery that consisted of the Mini-Mental State Examination (MMS), the Alzheimer's Disease Assessment Scale (ADAS), the SKT test (SKT), and the Brief Cognitive Rating Scale (BCRS) to assess the construct validity, sensitivity, and possible shortcomings of these tests. A control group of 47 age-matched persons was administered the same test battery to allow a comparison with reference values from other studies. Due to the design of the study, values of controls and patients did not overlap. Intercorrelations in patients were above 0.65 (p < 0.05 after Bonferroni correction) for all four cognitive tests. The ADAS and BCRS appeared to document the whole course of the disease in patients studied. The best differentiation with the SKT test could be obtained in mild to moderate dementia; however, due to the test's construction, a floor effect demonstrated its limitations in the case of severe dementia. Results obtained with the MMSE indicated the contrary: a ceiling effect showed its lack of differentiation in mild dementia. Therefore, a combination of tests should be used in the evaluation of cognitive deficits in the course of dementia of the Alzheimer type.

Activities of Daily Living↗
PubMed1992

[Importance of the EEG in early and differential diagnosis of dementia of the Alzheimer type].

The development of new parameters in the quantitative evaluation of EEG provides new diagnostic opportunities for the clinician. Reviewing all published papers on EEG and dementia over the last 10 years revealed 30 out of 428 studies discussing EEG alterations in relation to the severity of the disease. This approach provides useful information for early and differential diagnosis of dementia. Besides a generalised slowing-down represented by an increase of delta and theta and a decrease of alpha and beta in the frequency spectrum (also characterised by a reduction of the peak frequency), the topography of the alterations changes depending on the severity of the disease. For instance, the alpha activity loses its normally occipital orientation. In early stages of the disease, it is measured parietally ("anteriorized"). In advanced stages, the activity is equally distributed over the scalp. Some studies found significant alterations even in early stages of the disease, most pronounced in theta and beta activity, making the EEG a useful tool for the early diagnosis of dementia. But studies on the differential diagnostic value are lacking. The value of EEG could be improved after parameters like the EEG segmentation or the traditional parameters combined with cognitive stimulation have been sufficiently evaluated.

Aged↗
PubMed1992

Performance of patients with early HIV-1 infection on the Stroop Task.

HIV-seropositive and seronegative control subjects performed a standard paper-and-pencil version and an experimental reaction time version of the Stroop Color-Word Naming Task. Results indicated that both symptomatic and asymptomatic HIV-positive subjects showed an exaggerated Stroop effect compared to controls, but this increase was only apparent on the RT version of the task. Analysis of components of the effect indicated that HIV-positive subjects showed increased inhibition compared to controls but normal facilitation. These results suggest that HIV-related cognitive slowing has an attentional component, most likely involving controlled processes. In addition, these results emphasize the utility and sensitivity of RT measures in the study of early HIV-1 infection.

AIDS Dementia Complex↗
PubMed1992

Cognitive function and regional cerebral blood flow in Parkinson's disease.

In order to investigate relationships between cognition and regional brain function, we studied 20 non-demented patients with idiopathic Parkinson's disease (PD), 21 mildly demented patients with Alzheimer's disease (AD) and 24 control subjects using cognitive testing and single photon emission computerized tomographic (SPECT) measurements of relative regional cerebral blood flow (rCBF). Neuropsychological tests were grouped into clusters reflecting frontal lobe executive abilities, perseveration, memory and visuospatial ability, with a summary score summarizing performance in all four of these spheres. SPECT imaging utilized the tracer [123I]N-isopropyl-p-iodoamphetamine with a relative measure of regional tracer uptake normalized to occipital radiotracer uptake (rCBF ratios). Patients with PD performed more poorly than controls in all cognitive domains, and were intermediate to AD patients and controls in tests of memory and overall cognitive functioning. Those PD patients who performed most poorly on neuropsychological testing showed lowest rCBF ratios in left and right temporal lobes. Using a stepwise multiple regression procedure, we examined patterns of correlations between cognitive clusters and predictor variables, including rCBF ratios, in the PD patients. We found that while patient age was a strong determinant of performance on the memory cluster and the summary score, dorsolateral frontal lobe perfusion and scores on a depression inventory accounted for a greater proportion of the variance of the frontal lobe and perseveration clusters than did age. These results imply that different neural mechanisms are responsible for the different aspects of cognitive decline seen in PD patients, with overall cognitive function closely related to age and temporal perfusion, while frontal lobe abilities are more linked to frontal perfusion and the presence of depression.

Aged↗
PubMed1992

Decision-making speed in HIV-1 infection: a preliminary report.

OBJECTIVES: To test the efficacy of reaction time measures derived from cognitive psychology as measures of subclinical cognitive slowing in individuals with HIV-1 infection. DESIGN: Cognitive slowing is the primary deficit in AIDS dementia. One measure of cognitive slowing is decision-making speed, the discrepancy between simple and choice reaction times, which represents an index of central information processing time. METHODS: Nineteen HIV-seropositive and 13 control subjects performed a detection and decision task in a reaction time procedure. All subjects were administered measures of simple and choice reaction time, a control measure of rate of verbal encoding, and measures of psychological distress. RESULTS: Compared with controls, both symptomatic and asymptomatic HIV-seropositive subjects had significantly longer decision times, but performed the control task of rate of encoding normally. Simple reaction times correlated significantly with depression scores, but choice reaction times were unrelated to psychological distress. CONCLUSIONS: The results support mental slowing as the initial cognitive disturbance of HIV-1 infection and emphasize potential use of reaction times as markers of central nervous system involvement in HIV-1 infection.

Adult↗
PubMed1992

Spatial attention in HIV-1 infection: a preliminary report.

In a preliminary study, 30 nondemented human immunodeficiency virus (HIV-1) seropositive subjects without acquired immunodeficiency syndrome and 14 seronegative controls performed a reaction time measure of spatial attention. Compared with controls, seropositive asymptomatic subjects showed normal facilitation of reaction time at short cue-target intervals when attention was precued, but symptomatic subjects were impaired. However, asymptomatic subjects showed no evidence of normal inhibition of attention at the cued location at longer cue-target intervals, suggesting possible subtler spatial attentional deficits in this group. Cognitive slowing in HIV-1 infection may have an attentional component, with possible involvement of both automatic and controlled processes.

AIDS Dementia Complex↗
PubMed1991

Parathyroid hormone-related protein, chromogranin A, and calcitonin gene products in the neuroendocrine skin carcinoma cell lines MKL1 and MKL2.

We studied the production of parathyroid-hormone-related protein, chromogranin A, calcitonin and calcitonin-gene-related peptide in the neuroendocrine skin cell line, MKL1, and a subsequently derived cell line designated MKL2. Both cell lines had cytological, histological and electron-microscopic features typical of neuroendocrine differentiation. Immunohistology and radioimmunoassay studies demonstrated the presence of parathyroid-hormone-related protein, chromogranin A, calcitonin-gene-related peptide, and calcitonin in the MKL2 cell line and the last three substances in both cell lines. The secretion of each of the first three substances was regulated by phorbol in the MKL2 cells. Additional immunohistochemical studies demonstrated the variable expression of bombesin, substance P, and vasoactive intestinal polypeptide in MKL2 cells, and the expression of synaptophysin in both MKL1 and MKL2 cells. These studies demonstrate the neuroendocrine characteristics of the MKL cell lines and provide a novel model for studies of the production and interactions of several neuroendocrine proteins and peptides by human skin cells.

Bombesin↗
PubMed1988

New intrathecal drugs in Alzheimer's disease and psychometric testing.

Bethanechol chloride, a muscarinic agonist, was administered intrathecally to a sample of AD patients in double-blind crossover and open escalating-dose trials. There was a modest amelioration of disturbed behavior at a moderately high dose level, but no improvement in memory or cognition was seen at any dose. At the highest dose, cognition deteriorated. These findings, in conjunction with the results of the multicenter trial described by Harbaugh, suggest that the clinical efficacy of bethanechol in AD is limited. The disappointing results of trials with varied cholinomimetic therapies suggest that more than one biochemical abnormality is responsible for the AD dementia. The neuropeptide, somatostatin, is also reduced in AD, and the level of reduction is correlated with the degree of dementia. Manipulation of this transmitter, alone or in conjunction with acetylcholine, would appear to be a next logical step in the development of an effective neurotransmitter replacement therapy for AD. Implanted drug pumps will be needed for such clinical trials. The naturally occurring somatostatin-14 is not suitable because of its short half life. Sandostatin, an analog, is chemically stable and not metabolized by brain tissue. It does not cross the blood-brain barrier so that intrathecal administration is necessary. Pharmacological research in AD is complicated by a variety of psychometric problems including the criterion-related and construct validity of the outcome measures. Patients differ in their tolerance of various therapeutic agents and in the extent of the neurochemical pathology. It is critically important, therefore, to evaluate individual, as well as group, responses to treatment. The telephone log method may provide a useful way of generating enough observations for single subject analyses without overburdening the patient with repeated testing.

Activities of Daily Living↗
PubMed1988

Intraventricular bethanechol infusion for Alzheimer's disease: results of double-blind and escalating-dose trials.

Ten patients with biopsy-proven Alzheimer's disease (AD) received low-dose (0.35 mg/d) intraventricular bethanechol, a muscarinic agonist, and saline placebo in a 24-week double-blind crossover design. Eight of these ten patients later participated in an open escalating-dose (to 1.75 mg/d) trial of bethanechol. Patients' drug responses were assessed by neuropsychological examination and informant measures of activities of daily living, mood disturbance, and abnormal behavior. Bethanechol appears to have a narrow therapeutic window for positive effects; low doses did not reliably alter patient functioning, moderately increased doses appeared to have a palliative effect on patient mood and behavior, and the highest dose was detrimental to patient functioning. Bethanechol does not appear to ameliorate the dementia of AD, but may exert a mildly positive effect on patient behavior and mood.

Aged↗
PubMed1987

Catalase protection of neuronal survival in vitro is not directed to the accumulation of peroxides in the culture medium.

Walicke et al. (1986, J. Neurosci. 6, 1114-1121) have shown that catalase can replace the pyruvate requirement for survival of CNS neurons cultured in vitro. Since presently the only known function of catalase is the enzymatic degradation of hydrogen peroxide to water and oxygen, the simplest interpretation of the ability of catalase to support neuronal survival would be that catalase removes from the culture medium hydrogen peroxide. To test this hypothesis 8-day embryonic chick forebrain cells were cultured for 24 hr in a modified Eagle's Basal Medium with the serum-free supplement N1 (HEBM/N1) in the presence or absence of Phenol Red, 20 micrograms/ml catalase, 1 mM pyruvate, and/or 25 mM N-2-hydroxyethylpiperazine-N'-2-ethane-sulfonic acid (HEPES) on a polyornithine-laminin substratum. The various media were then assayed for peroxide content using the potassium iodide method described by Wang and Nixon (1978, In Vitro 14, 714-722). The present data reveal that (1) HEBM/N1 normally contains approximately 50 microM peroxides, little of which is hydrogen peroxide, (2) the organic peroxide levels accumulating in this medium are not reduced by either catalase or pyruvate, and (3) medium modifications can reduce to no longer detectable levels the peroxides accumulating in the medium, but catalase or pyruvate is still required for neuronal survival. We conclude that catalase must exert its survival-promoting action at levels other than peroxides accumulating in the culture medium.

Animals↗
PubMed1987

Detachable balloon occlusion of carotid-cavernous sinus fistula.

A carotid-cavernous sinus fistula, an abnormal communication between the carotid artery and the cavernous sinus, may develop as a result of trauma or spontaneously. The goal of treatment is to occlude the fistula while preserving blood flow in the carotid artery. Intravascular embolization by means of a detachable balloon achieves both these goals without craniotomy. Clinical signs, diagnosis, treatment, and a nursing care plan for patients with carotid-cavernous sinus fistula are presented. Two case studies along with nursing interventions are described.

Adult↗
PubMed1987

Cortical biopsy results in Alzheimer's disease: correlation with cognitive deficits.

Neuropsychologic and pathologic data are presented for a group of 11 patients with a clinical diagnosis of probable Alzheimer's disease (AD) according to recently proposed criteria. In all cases, the diagnosis was verified by cortical biopsy. In addition, increased cortical plaque counts were associated with greater deficits in language production and comprehension and poorer performance on an index of global mental status. These results suggest that a clinical diagnosis of AD is very accurate when patient selection is restricted to typical cases and that language deficits may provide a useful indicator of severity of disease in AD patients.

Aged↗
PubMed1986

Traumatic aneurysms.

A traumatic aneurysm is a potentially lethal complication of head trauma. The problem is unusual but not rare. The majority of traumatic aneurysms are caused by blunt injuries to the head (62%), although penetrating wounds (27%) and iatrogenic trauma (11%) during intracranial surgery are also well recognized. The pathogenesis, diagnosis, and management of traumatic aneurysm are discussed, with focus on the patient course and nursing implications of a case study.

Adolescent↗
PubMed1985

Ruptured aneurysm in pregnancy.

Within the last ten years, twenty pregnant women with ruptured intracranial aneurysms were managed at Los Angeles County-University of Southern California Medical Center. Difficulties encountered in the care of these patients will be illustrated with case studies. In two patients, failure to diagnose subarachnoid hemorrhage delayed management. In another patient, cerebral vasospasm complicated the course. Selection of appropriate diagnostic tests, timing of surgery, importance of fetal monitoring, and method of delivery will be discussed.

Adolescent↗