Biomedical subjects

M Albert

Publications and source records attributed to M Albert.

At least 109 records · Page 6Linked to original sources

PubMed1993

Thyrotropin response to thyrotropin-releasing hormone in patients with dementia of the Alzheimer type.

Eleven patients with senile dementia of the Alzheimer type and 11 age-matched control subjects were given the thyrotropin-releasing hormone (TRH) test. The two groups did not differ with respect to peak thyrotropin (TSH) response or TSH levels at baseline, 20, 30, and 45 min after TRH injection. There were significant differences between the groups on Hamilton Depression Rating Scale scores (p < 0.03), although neither group met clinical criteria for depression. Items that were significantly different pertained to depressed mood, loss of interest, loss of insight, suicidal ideation, and obsessional symptoms.

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PubMed1993

Brain electrical correlates of psychological measures: strategies and problems.

We explore relationships between brain electrical activity and cognitive performance where qEEG data are correlated with psychological variables gathered at a different time. For a population of 202 healthy adults using univariate and multivariate correlation techniques in a split half replication design, we confirm prior findings that subjects with better psychological scores show shorter evoked potential (EP) latency, suggesting that speed of processing is an important factor in cognitive performance. By canonical correlation we demonstrate a consistent, replicable relationship between electrophysiological and behavioral data. We suggest that reliance upon univariate correlation may have fueled early controversies about relationships between electrophysiology and IQ. In addition we correlate psychological factors with the entire qEEG data set (both EP and spectral analyzed EEG) and demonstrate the use a multidimensional image graphics techniques to assist in visual assessment of the resulting correlation matrices.

Adult↗

PubMed1993

High, usual and impaired functioning in community-dwelling older men and women: findings from the MacArthur Foundation Research Network on Successful Aging.

The objective of this study is to determine the range of complex physical and cognitive abilities of older men and women functioning at high, medium and impaired ranges and to determine the psychosocial and physiological conditions that discriminate those in the high functioning group from those functioning at middle or impaired ranges. The subjects for this study were drawn from men and women aged 70-79 from 3 Established Populations for the Epidemiologic Study of the Elderly (EPESE) programs in East Boston MA, New Haven CT, and Durham County NC screened on the basis of criteria of physical and cognitive function. In 1988, 4030 men and women were screened as part of their annual EPESE interview. 1192 men and women met criteria for "high functioning". Age and sex-matched subjects were selected to represent the medium (n = 80) and low (n = 82) functioning groups. Physical and cognitive functioning was assessed from performance-based examinations and self-reported abilities. Physical function measures focused on balance, gait, and upper body strength. Cognitive exams assessed memory, language, abstraction, and praxis. Significant differences for every performance-based examination of physical and cognitive function were observed across functioning groups. Low functioning subjects were almost 3 times as likely to have an income of < or = $5000 compared to the high functioning group. They were less likely to have completed high school. High functioning subjects smoked cigarettes less and exercised more than others. They had higher levels of DHEA-S and peak expiratory flow rate. High functioning elders were more likely to engage in volunteer activities and score higher on scales of self-efficacy, mastery and report fewer psychiatric symptoms.

Activities of Daily Living↗

PubMed1993

Multicenter study of predictors of disease course in Alzheimer disease (the "predictors study"). I. Study design, cohort description, and intersite comparisons.

Clinicians should be able to provide the patient with Alzheimer disease (AD) and the family with an accurate prediction of what to expect, but the variability in the rate of disease progression precludes this. In several previous studies, specific clinical signs such as muscular rigidity, myoclonus, and hallucinations or delusions were associated with rapid progression to a more severe stage of dementia or death. The "Predictors Study," a longitudinal study at three independent sites, was designed to develop a predictor model of the natural history of Alzheimer disease. The study was conducted at three study sites, New York, Baltimore, and Boston in a cohort of 224 patients with early probable AD. This article describes the design and implementation of the Predictors Study, and compares features of the study cohort at baseline across sites. Patients were all at the mild stage of disease at entry and were relatively comparable across sites. Extrapyramidal signs and delusions were common, but myoclonus was rarely observed.

Activities of Daily Living↗

PubMed1993

Multicenter study of predictors of disease course in Alzheimer disease (the "predictors study"). II. Neurological, psychiatric, and demographic influences on baseline measures of disease severity.

The "Predictors Study" is a prospective cohort study of the natural history of Alzheimer disease (AD), the aim of which is to identify milestones in disease progression and to develop a model to predict disease course in individual patients. The empirical background to this study is based on previous reports that the presence of extrapyramidal signs (EPS), myoclonus, and psychosis in AD may signify greater disease severity at any given stage and a more rapid course of the disease over time. The present analyses were conducted to determine whether these independent "predictor" variables were associated with greater disease severity at baseline within a new cohort of 224 mild AD patients recruited from three different medical centers (in New York, Baltimore, and Boston). Measures of disease severity were provided by the modified Mini-Mental State Examination (mMMSE) and the Blessed Dementia Rating Scale (BDRS), which measures functional capacity. Independent variables were EPS, delusions, and slowing of the posterior dominant EEG rhythm. The frequency of myoclonus and hallucinations was too low to permit adequate statistical assessment of their effects at this time. EPS and EEG slowing were associated with low mMMSE scores, whereas delusions were primarily associated with impaired functional capacity. These effects were independent of the influence of age and disease duration. These results indicate that the effects of these independent variables can be detected at mild stages of AD and that these effects can be generalized across different geographical regions.

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PubMed1993

Microtubule organization during the cell cycle of the primitive eukaryote dinoflagellate Crypthecodinium cohnii.

The complete microtubular system of the dinoflagellate Crypthecodinium cohnii Biecheler is described, as seen by confocal laser scanning fluorescence microscopy and labelling with anti-beta-tubulin antibody. This technique allowed us to observe the organization of the subcortical and internal cytoskeletons and the mitotic microtubular system, and their changes during the cell cycle. These observations are compared with those made in cryosections by light microscopy and in fast-freeze-fixed, cryosubstituted cells by electron microscopy. We show the organization of the cortical microtubules, and in particular of the thick microtubular bundles arranged as a three-pronged fork from which they seem to emanate. This fork emerges from a peculiar cytoplasmic zone at the pole of the cell and is in contact with the region of the kinetosomes, at the cingulum. During the G1 phase, only a single, radial microtubular bundle (a "desmose") is observable in the inner part of the cytoplasm. One of its ends is near the flagellar bases and the other end is close to the nucleus in the centrosome region. During the S phase, the flagella drop off, the cell encysts and the kinetosomes duplicate. In mitosis, the cortical microtubules and the intracytoplasmic microtubular bundles do not depolymerize. The microtubular fork, desmose and centrosome double and migrate, while the divided kinetosomes stay in the same place. Later, the centrosomes organize the extranuclear spindle, which is connected to the kinetosome region by the microtubular desmose. The convergent end of the three-pronged fork seems to be in contact with the centrosome region. In early and mid-prophase, thick microtubular bundles pass through the nucleus in cytoplasmic channels and converge towards the two poles. Asters were never seen at the spindle poles. The channels and microtubular bundles in the spindle double in number during late prophase and lengthen in early anaphase. The spindle bundles diverge in late anaphase, extend to very near the plasma membrane and depolymerize during telophase. The cleavage furrow in which tubulin and actin are characterized appears in anaphase, formed by invagination of plasma membrane in the kinetosome region. The structure and rearrangements of the Crypthecodinium cohnii microtubular system are compared with those of other dinoflagellates and protists and of higher eukaryotes.

Animals↗

PubMed1993

Complex study of the physiological role of aluminium. II. Aluminium tolerance tests in broiler chickens.

Aluminium (Al) tolerance tests were carried out in 8 x 24 (a total of 192) broiler chickens pre-reared for 17 days. Chickens of the control group were fed a standard poultry grower diet ad libitum, while those in six experimental groups received a diet supplemented with different (200, 500 and 1,000 mg/kg of feed) doses of Al supplied in the form of AlCl3 and, in two cases, with the same dose of P added to the feed in the form of MCP, up to 52 days of age. Chickens of one group were fed a diet containing 3,000 mg Al per kg of feed for 70 days. The acidic pH of AlCl3 solution sprayed onto the feed was neutralized by adding a sufficient amount of NaHCO3 solution in all but one group. The birds' health status was monitored regularly throughout the feeding trial. Their body mass gain and feed consumption were recorded weekly. At the end of the trial, 3-10 chickens per group (a total of 40 birds) were exsanguinated, subjected to gross pathological examination, and samples were taken from 9 organs (liver, kidney, skeletal muscle, myocardium, brain, spleen, testicle, lungs and tubular bones) for light and electron microscopic examination and for the regular determination of 8 elements (Ca, P, Mg, Zn, Fe, Mn, Cu, Al). In addition, samples were taken from the organs of 2-5 chickens per group for analysis for additional 6 elements (Mo, Co, Ni, Sr, Na, K). From the results obtained the following main conclusions were drawn: (i) With the exception of four birds culled during the trial, all chickens remained symptomless throughout, and all chickens except those fed a diet supplemented with 3,000 mg/kg aluminium developed properly. (ii) The body mass of chickens in groups fed a diet supplemented exclusively with Al decreased moderately (by 67, 69 and 88 g, respectively), depending on Al concentration of the diet. Chickens fed a diet containing 3,000 mg/kg Al showed a very substantial (621.3 g; 32%) decrease in body mass Phosphorus supplementation did not markedly affect the body mass gain. (iii) Specific feed utilization was satisfactory (2.100-2.210 g/kg body mass). The very poor feed utilization of chickens subjected to the heaviest Al load can be attributed to the temporary disturbance of acid-base balance caused by the non-buffered AlCl3 solution.(ABSTRACT TRUNCATED AT 400 WORDS)

Aluminum↗

PubMed1993

Extending continuous versus discontinuous conditioned stimuli before versus after unconditioned stimuli.

Conditioned suppression was used with rats to study the effects of extending conditioned stimuli (CSs) before versus after the delivery of unconditioned stimuli. These extensions are termed B and A extensions, respectively. Within-group designs were used to compare the effects of extending CSs when 2-min parts of those CSs were separated by temporal gaps of 6 min versus a separation of no gap. The results were as follows: (a) B extensions weakened conditioning more than did A extensions, with or without gaps; (b) under some conditions, this asymmetrical effect persisted with extended training; (c) gaps between 2-min parts of a B extension had no detectable effect; and (d) under some parameter values, gaps between 2-min parts of an A extension weakened conditioning significantly. These results are better predicted by the Sometimes Opponent-Process model (SOP; A. R. Wagner, 1981) than by the Rescorla-Wagner-Frey-Sears real-time model (J. J. B. Ayres, M. Albert, & J. C. Bombace, 1987).

Animals↗

PubMed1992

Comparative analysis of computed tomographic and magnetic resonance imaging scans in Alzheimer patients and controls.

Ten patients with Alzheimer's disease underwent computed tomography and magnetic resonance imaging at the same point in time. The mean Mini-Mental State examination score of the patients was 23, indicating that they were mildly impaired. Ten age-equivalent controls also obtained computed tomographic and magnetic resonance imaging scans. A semiautomated computer program analyzed nine comparable regions of interest on each set of scans. When regions of interest from both types of scans were combined in the same discriminant function analysis, the first two variables selected were from the magnetic resonance imaging data set, and they significantly differentiated 95% of the patients and controls.

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PubMed1992

A controlled study of the prevalence of cognitive dysfunction in randomly selected patients with systemic lupus erythematosus.

OBJECTIVE: To investigate the prevalence of cognitive dysfunction in randomly selected patients with systemic lupus erythematosus (SLE). METHODS: Randomly selected, ambulatory patients with SLE (n = 49) or with rheumatoid arthritis (RA) (n = 40) completed neuropsychological tests. These included Associate Learning, Switching Attention, Continuous Performance, Associate Recall, Hand-Eye Coordination, Pattern Comparison, Pattern Memory, the Stroop Color and Word Test, and the Symptoms Checklist-90R. Results were evaluated by multiple linear regression analysis. RESULTS: SLE patients had poorer performance than RA patients on the test of attention (P = 0.002) and tests of visuospatial ability (P = 0.03) and P = 0.04), independent of age, education, or steroid use. The conservative level of statistical significance, adjusting for multiple comparisons, was 0.005. SLE patients reported more symptoms of cognitive difficulty. CONCLUSION: Cognitive dysfunction is common in ambulatory SLE patients as measured by standardized tests and is a cause of distress and impaired functioning. Self-reported cognitive difficulty appears to correlate with objective performance.

Adult↗

PubMed1992

Unrestricted principal components analysis of brain electrical activity: issues of data dimensionality, artifact, and utility.

Principal components analysis (PCA) was performed on the 1536 spectral and 2944 evoked potential (EP) variables generated by neurophysiologic paradigms including flash VER, click AER, and eyes open and closed spectral EEG from 202 healthy subjects aged 30 to 80. In each case data dimensionality of 1500 to 3000 was substantially reduced using PCA by magnitudes of 20 to over 200. Just 20 PCA factors accounted for 70% to 85% of the variance. Visual inspection of the topographic distribution of factor loading scores revealed complex loadings across multiple data dimensions (time-space and frequency-space). Forty-two non-artifactual factors were successful in classifying age, gender, and a separate group of 60 demented patients by linear discriminant analysis. Discrimination of age and gender primarily involved EP derived factors, whereas dementia primarily involved EEG derived factors. Thirty-eight artifactual factors were identified which, alone, could not discriminate age but were relatively successful in discriminating gender and dementia. The need to parsimoniously develop real neurophysiologic measures and to objectively exclude artifact are discussed. Unrestricted PCA is suggested as a step in this direction.

Adult↗

PubMed1992

Unexplained in-vitro fertilization failure: implication of acrosomes with a small reacting region, as revealed by a monoclonal antibody.

To determine the acrosomal characteristics related to in-vitro fertilization (IVF) outcome, spermatozoa from 50 men whose wives had resorted to IVF have been studied by indirect immunofluorescence microscopy with anti-human pro-acrosin monoclonal antibody 4D4 (mAb 4D4), prior to and after incubation in a capacitating medium. The antibody labelled only the acrosomal principal region (APR), revealing its shape (i.e. normal, small or amorphous) and its status (i.e. unreacted, partially or totally reacted). The IVF outcome distinguished: (i) spermatozoa which were able to fertilize at least one oocyte in vitro (group I; n = 25) and (ii) spermatozoa which failed to fertilize any oocyte in vitro (group II; n = 25). The semen characteristics of the two sperm groups, including the acrosome morphology, were similar according to conventional analysis. The mAb 4D4 detected in both the whole and the swim-up sperm cell fractions a lower percentage of normal APR in group II (< 50% for 10 patients in group II versus one patient from group I), which was related to a higher percentage of small APR. Moreover, after 21 h incubation, group II had a lower acrosomal loss index. The spermatozoa of five patients of this infertile group II did not undergo acrosomal modification whereas spermatozoa of all group I patients underwent the acrosomal reaction. The data showed that the relationship between acrosomal anomalies and IVF failure is mainly due to an increased incidence of acrosomes with a reduced size of the region involved in the acrosome reaction. Immunodiagnosis of this acrosomal region by means of mAb 4D4 is informative for IVF outcome.

Acrosin↗

PubMed1992

The Test for Severe Impairment: an instrument for the assessment of patients with severe cognitive dysfunction.

OBJECTIVE: To develop a reliable and valid test of cognitive function suitable for patients with severe cognitive impairment. DESIGN: Administration of a test; test-retest reliability; comparison to traditional test. SETTING: Chronic long-term-care facility. PATIENTS OR OTHER PARTICIPANTS: The participants were 40 elderly residents with severe cognitive impairment. MAIN OUTCOME MEASURES: Results of the Test for Severe Impairment (TSI) and its subsections (language, memory, executive function, and motor performance); correlation of test and retest scores; correlation of TSI with Mini-Mental State Exam. RESULTS: The TSI was significantly correlated with the Mini-Mental State Exam (r = 0.83, P less than or equal to 0.0001). Test-retest reliability was high (r = 0.96, P less than 0.0001). The internal reliability of the test was also good (alpha = 0.90). Preliminary result of a factor-analysis suggests that factor scores may be derived that relate to memory, language production, and knowledge of body parts. CONCLUSIONS: The TSI is a valid and reliable test of cognitive function in patients with severe cognitive impairment. It is appropriate to use it as a unified scale.

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PubMed1992

Intake of different concentrations of sucrose and corn oil in preweanling rats.

To investigate the orosensory control of ingestion in preweanling rats, we infused one of the following liquids continuously through anterior sublingual intraoral catheters for 20 min: sucrose solutions (5, 10, 20, and 40%) and corn oil emulsions (6.25, 12.5, 25, 50, and 100%). Pups were tested at 7, 14, 21, and 28 days of age. Each pup was tested only once. Intake of sucrose and of corn oil became increasingly correlated with concentration from 7 to 21 days. Sucrose elicited more intake than water by day 7, whereas corn oil did not until day 14. Low concentrations of sucrose had differential effects on intake by day 14, but low concentrations of corn oil emulsions did not have differential effects on intake until day 21. At all ages, the peak intake of sucrose was significantly larger than the peak intake of corn oil. These differences are probably not based on prior experience because each test of ingestion represented a first exposure to the stimulus. Thus we suggest that the differences are due to the maturation of the orosensory control of ingestion by sucrose and corn oil.

Aging↗

PubMed1992

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part III. Reliability of a standardized MRI evaluation of Alzheimer's disease.

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) has developed procedures for standardized imaging and reporting of magnetic resonance (MR) findings in Alzheimer's disease (AD) for use by neuroradiologists in multiple medical centers using a variety of MR equipment and field strengths. After initial pretesting, we revised the protocol, expanded the summary rating scale to seven points, and added more illustrations. Fourteen participating neuroradiologists evaluated 28 MR scans of elderly patients, giving us the basis for judging interrater agreement. We obtained acceptable intraclass correlations (greater than 0.79) for rating the size of the lateral and third ventricles and the temporal horn. Less satisfactory intraclass correlations occurred when rating other areas, including (1) global atrophy of the brain (0.70); (2) dilatation of the sulci of the temporal lobe (0.66); (3) frequency, location, and severity of white matter lesions (0.77); (4) sylvian fissure enlargement (0.70); and (5) cerebral sulcal dilatation (0.64). We also saw considerable variation in the reporting of cortical and lacunar infarcts. Despite careful design of the rating methodology and readings by experienced neuroradiologists, we did not find satisfactory interrater agreement for interpreting MR findings in elderly subjects. These findings may explain the difficulties encountered in applying similar subjective rating techniques that meet with success at one institution to multicenter studies. More objective and reproducible procedures are needed for interpretation of neuroimaging findings of AD in multicenter studies.

Alzheimer Disease↗

PubMed1992

Interaction between Bordetella bronchiseptica and toxigenic Pasteurella multocida on the nasal mucosa of SPF piglets.

The interaction between Bordetella bronchiseptica and type D toxigenic Pasteurella multocida was studied in five groups of 4 specific-pathogen-free (SPF) piglets each. At 28 days of age, piglets of groups 3 and 4 were inoculated into both nostrils with 10(8) colony-forming-units (CFU) of a non-dermonecrotic toxin (DNT)-producing, phase I strain of B. bronchiseptica. Piglets of groups 1 and 3 were treated intranasally with a sonic extract of the non-toxic strain of B. bronchiseptica and those of groups 2 and 4 with B. bronchiseptica DNT into the left nostril. Sonic extract and DNT treatment was started at 33 days of age and lasted for 5 days. Piglets of group 5 served as controls. At the age of 37 days, piglets of all groups except group 5 were inoculated into both nostrils with 5 x 10(7) CFU of toxigenic P. multocida. At slaughter at 50 days of age, P. multocida was recovered from the left nasal cavity of 3 piglets of group 2 and all piglets of group 4. In piglets inoculated with B. bronchiseptica DNT the mucosal epithelial cells of the left nasal cavity showed loss of cilia, regressive lesions such as vacuolation, karyopycnosis and necrosis, hypertrophy of the epithelium, infiltration of the epithelium and submucosa by inflammatory cells, could also be seen. The results suggest that action of the B. bronchiseptica DNT on the nasal mucosa is a precondition of the growth of P. multocida in the nasal cavity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Microtubular spindle and centrosome structures during the cell cycle in a dinoflagellate Crypthecodinium cohnii B.: an immunocytochemical study.

In order to determine if a mitotic spindle organizing center is present in dinoflagellate cells, we used a library of 12 monoclonal antibodies obtained by immunizing mice with isolated human centrosomes. When tested by immunofluorescence on cryosections of the dinoflaggelate Crypthecodinium cohnii B., a positive labeling was obtained with three of these antibodies. In interphase cells, the anti-centrosome antibodies labeled structures located either in the cell periphery, corresponding probably to both basal bodies (i.e. kinetosomes) and in the perinuclear area. In the latter case, two punctate structures were observed near the nuclear envelope. They have never been described, either in light, or in electron microscopic studies of dinoflagellates. We have designated them as centrosome-like structures. A microtubular desmose reacting positively with anti-tubulin Ab was also visible, linking kinetosomes and centrosome-like structures. During mitosis, the double punctate structures were observed at the poles of the nucleus. Double immunolabeling with tubulin and anti-centrosome Ab was also carried out and strongly suggested that in mitotic cells, centrosome-like structures, located at the poles of the mitotic spindle, were associated with microtubular bundles and probably organize and polarize them. These data indicate the existence of centrosome-like structures in C. cohnii cells and the strong conservation of some centrosomal epitopes from dinoflagellates to human. One of the antibodies (CTR 210) recognized by immunoblotting, a single protein band at 72 kDa from a total protein extract. The direct demonstration that this protein is located at the centrosome-like structures and at the kinetosomes deserves further study.

Animals↗

PubMed1991

An empirical study of diagnostic criteria for delirium.

OBJECTIVE: The objective of this study was to determine empirically how many patients are identified as delirious or nondelirious according to DMS-III, DMS-III-R, and ICD-10 criteria. METHOD: Daily, a trained research assistant using a structured instrument to detect the presence of symptoms of delirium evaluated 325 elderly patients who were admitted to a general hospital for acute medical problems. Each patient's symptoms were then compared with these diagnostic criteria sets to determine if the patient met criteria for delirium. RESULTS: DSM-III criteria were the most inclusive: they identified 125 patients as delirious. DSM-III-R identified a somewhat different group of 106 patients as delirious. ICD-10 criteria identified only 30 patients as delirious. CONCLUSIONS: The development of new criteria for delirium (e.g., DSM-IV) will have to balance the need to define a pure group of patients for research purposes with the need to include cases of clinical interest. Changes in criteria should be based on data such as those presented in this paper.

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