Biomedical subjects

B L Miller

Publications and source records attributed to B L Miller.

224 records · Page 13Linked to original sources

PubMedDate not supplied

Neuroimaging findings in twins discordant for Alzheimer's disease.

Data from computed tomography (CT) scans of 12 twin pairs in which one partner had Azheimer's disease (AD) and the other partner is cognitively intact were analyzed to study structural brain features associated with AD while controlling for familial factors. Visual ratings and analysis of quantified areas and volumes indicated that AD twins showed more dilation of temporal horns, lateral ventricles and third ventricle, and more atrophy of temporal lobes, particularly in the anterior temporal/perisylvian area, than their healthy cotwins. Demented twins did not have smaller intracranial areas or overall brain volumes than their intact partners. The apolipoprotein sigma-4 allele was associated with greater dilation of lateral ventricles and ventricular volume. Significant intrapair correlations were found for total intracranial area and volume, cerebellar area and white matter lesions.

Aged↗

PubMedDate not supplied

First symptoms--frontotemporal dementia versus Alzheimer's disease.

Frontotemporal dementia (FTD) is often misdiagnosed as Alzheimer's disease (AD). We hypothesized that the first symptoms associated with FTD would be different from those seen in AD and that the first symptoms in FTD would reflect loss of function in the frontal region with the greatest degree of degeneration. The objective of the study was to compare the earliest symptoms in patients with FTD and AD, and to delineate the symptoms that were associated with right, left or bilateral frontotemporal degeneration in FTD. The first symptoms in 52 FTD and 101 AD patients were determined in retrospect. Based on functional imaging studies, the FTD patients were divided into those with predominantly bilateral (n = 15), left-sided (n = 19) and right-sided (n = 18) patterns of atrophy. The results showed that disinhibition, social awkwardness, passivity and loss of executive function were more common in FTD, while memory loss was more common in AD. Disinhibition was greatest in the asymmetric right-sided group, language dysfunction was commonest in the asymmetric left-sided group and loss of executive function was most frequent in the bilateral group. In summary, different first symptoms appeared in FTD and AD, which may help distinguish between the diseases. The anatomic site for FTD largely determined the kind of first symptoms.

Aged↗

PubMedDate not supplied

Relationship of family history scores for stroke and hypertension to quantitative measures of white-matter hyperintensities and stroke volume in elderly males.

White-matter hyperintensities (WMHI) are frequently associated with cerebrovascular risk factors in the elderly, particularly hypertension, and have been interpreted as a subclinical form of ischemic brain damage. WMHI, clinical stroke and blood pressures show significant genetic influences. The objective of this study was to determine whether a relationship exists between family history of stroke and/or hypertension in first degree relatives and WMHI in the elderly. WMHI and stroke (CVA) volumes were quantified from brain MRI performed on 414 white, male twins born between 1917 and 1927 (average age 72.3 +/- 2.9 years). WMHI, adjusted for age and head size, was significantly correlated with the family history score (r = 0.21, p < 0.001). Dividing the family history scores into quintiles revealed significant differences in WMHI by quintile mean (p < 0.05). Subjects in the highest quintile of family history score had the highest mean WMHI. Recalculation of the family history score, by only counting relatives reported to have had a clinical stroke as a positive event, revealed a nonsignificant correlation with WMHI, but the correlation of the family history score with MRI CVA volume was significant (p < 0.05). Stepwise multivariate analysis including ApoE status, current smoking status, smoking packyear history, Doppler ankle/arm blood pressure ratios, current and long term hypertensive status and current systolic and diastolic pressures indicated that the stroke/hypertension family history score was the single best predictor (p < 0.01) of WMHI volumes. Family history was not an independent predictor of CVA volume.

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PubMedDate not supplied

Neuronal ultrastructural abnormalities in a patient with frontotemporal dementia and motor neuron disease.

Motor neuron disease (MND) can be associated with frontotemporal dementia (FTD) and circumscribed lobar atrophy of frontal and temporal lobes. Neuropathological correlations were sought in postmortem studies from a woman with these associated conditions. Cerebral blood flow imaging and autopsy showed cortical abnormalities in the frontal and temporal lobes, but typical argyrophilic Pick's bodies were absent and ubiquitin-positive neuronal cytoplasmic inclusions were rare. However, hematoxylin and eosin staining revealed eosinophilic, granular, central cytoplasmic 'clearing' in most neurons of the substantia nigra and in cervical anterior horn cells. Electron microscopy showed that these neurons contained a central cytoplasmic zone cleared of neuromelanin and normal cytoplasmic organelles containing small mitochondria with matrix inclusions and randomly oriented filamentous material. A mitochondrial dysfunction or defective transport of mitochondria into axonal processes needs to be studied as a potential cause for the coassociation of MND and FTD.

Atrophy↗

PubMedDate not supplied

Dietary changes, compulsions and sexual behavior in frontotemporal degeneration.

The occurrence of weight gain, sweet and carbohydrate craving, hyposexuality, and compulsions in frontal lobe dementia (FLD) compared to Alzheimer's disease (AD) was evaluated. FLD is a progressive dementia with a high rate of misdiagnosis and therefore better diagnostic criteria for FLD are needed. Fourteen patients meeting research criteria for AD were compared to 14 with suspected FLD. All had cerebral perfusion measured with xenon-133 and imaged with HMPAO using brain-dedicated SPECT. The FLD group showed frontotemporal and AD posterior temporoparietal hypoperfusion. The primary caregivers were queried regarding weight gain, sweet/carbohydrate preference, sexual drive, and compulsions. Differences were compared with Fisher's exact test. The following was found in FLD versus AD: Weight gain in FLD patients amounted to 64% (AD 7%), carbohydrate craving was 79% (vs. 0%) and compulsive behavior 64% (vs. 14%). The differences for these symptoms were statistically significant, whereas for the symptoms increased sexual drive (8 vs. 8%) and reduced sexual drive (54 vs. 23%) no significant difference could be found. In FLD the first symptoms were often dietary changes or hyposexuality. Compulsions were more bizarre and severely disabling in FLD than in AD. Dietary changes, hyposexuality, and disabling compulsions are prominent early symptoms in FLD but not AD. The cause of these symptoms may be due to both frontal and subcortical serotonin loss and dysfunction of the anterior temporal lobes.

Alzheimer Disease↗

PubMedDate not supplied

Progressive right frontotemporal degeneration: clinical, neuropsychological and SPECT characteristics.

The behavioral, neuropsychological and single photon emission computerized tomography characteristics of 5 patients with progressive degeneration of the right hemisphere are described. In all, the brain regions with greatest involvement were right-frontal and temporal. Psychosis, compulsions and behavioral disinhibition were the dominant, and often first, symptoms. Affect was flattened and the patients seemed distant and remote. Neuropsychological testing did not reveal a consistent pattern that helped localize the abnormality to the right frontotemporal region. These patients contrast dramatically to those with left frontotemporal degeneration in whom behavior and psychiatric status is often normal. This study suggests that the right hemisphere may be primary for the control of social conduct.

Aged↗

PubMedDate not supplied

Frontal lobe cognitive functions in aging: methodologic considerations.

The empirical literature has been contradictory regarding whether frontal functions decline with age, perhaps due to important differences across studies in medical and psychiatric exclusion criteria. We review literature and present preliminary data suggesting that frontal lobe functions are particularly affected by several medical and psychiatric disorders common in old age. Investigations of frontal lobe functions in aging require careful screening of subject samples; otherwise, any impact of age on cognition is contaminated by the effects of coexistent physical and/or psychiatric illness.

Aging↗

PubMedDate not supplied

An improved microbiological assay for chlortetracycline in avian plasma.

Bacillus cereus was used as the assay organism for the quantification of chlortetracycline (CTC) in avian plasma. Antibiotic medium #8 gave significantly larger zones of inhibition than nutrient agar 1.5% when used as the assay medium (P less than or equal to 0.05). When the CTC concentration was measured in serum, citrated plasma, heparinized plasma, and oxalated plasma, no significant differences were found between the inhibition zone diameters produced on antibiotic medium #8. However, there was a significant decrease in the zone diameters produced on this medium when citrated whole blood, oxalated whole blood, and heparinized whole blood were used instead of plasma. The length of incubation of assay plates was inversely related to the inhibition zone diameter, with an incubation time of 8 hr giving the largest and most distinct zones. Storing prepared assay plates at 4 C for 24 hr before use appeared to decrease the variability of the inhibition zone diameters. Storage of citrated plasma at 4 C for 48 hr and at -60 C for 9 days resulted in no significant decreases in CTC concentrations.

Animals↗