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Biomedical subjects

R Katzman

Publications and source records attributed to R Katzman.

At least 19 recordsLinked to original sources
PubMed1992

Comparisons of verbal fluency tasks in the detection of dementia of the Alzheimer type.

The performances of 89 patients with dementia of the Alzheimer type (DAT) and 53 demographically matched elderly normal control subjects were compared on four verbal fluency measures (category, letter, first names, and supermarket fluency). Receiver operating characteristic curves were plotted to determine each fluency tasks' sensitivity (ie, true-positive rate) and specificity (ie, true-negative rate). Category fluency demonstrated the greatest degree of discrimination between patients with DAT and normal control subjects (sensitivity, 100%; specificity, 92.5%); letter fluency was the least accurate (sensitivity, 89%; specificity, 85%). Separation of patients with DAT by gender revealed similar findings. In further analyses with a subgroup of 21 mildly impaired patients with DAT, category fluency lost none of its discriminative capabilities, whereas all other fluency measures showed marked reductions in discriminability. We conclude that this superiority of category fluency is due to its dependence on the structure of semantic knowledge, which deteriorates in the early stages of DAT.

Aged↗
PubMed1992

Serological alpha 1-antichymotrypsin in Down's syndrome and Alzheimer's disease.

alpha 1-Antichymotrypsin (ACT) is a serine protease inhibitor that is markedly elevated in the serum and cerebrospinal fluid of patients with Alzheimer's disease (AD). Patients with Down's syndrome are known to develop neuropathological changes of AD by age 40 years and many become demented. Therefore, in the present study, we obtained serum ACT levels from patients with Down's syndrome and AD, diagnosed by autopsy or clinically, and healthy control subjects. Newman-Keuls' multiple range test revealed a significantly greater (p less than 0.01) mean ACT level in the Autopsy AD (906.4 +/- 94.64 mg/L) and Clinical AD (745.00 +/- 59.95 mg/L) groups in contrast to the Old Control group (531.00 +/- 23.05 mg/L). The mean ACT level of the Down's Syndrome group (513.33 +/- 14.73 mg/L) was not significantly different from that of the Young Control subjects. Furthermore, we did not observe a positive correlation of ACT levels with age in the Down's Syndrome group, in spite of the age-dependent premature increase in neuropathological changes of AD that are known to occur in patients with Down's syndrome. A positive correlation between serum ACT levels and the density of plaques or tangles, neuropathological hallmarks of AD, in brains of patients with AD also did not exist. Thus, our results suggest that ACT levels may not parallel the development of the classical neuropathological hallmarks of AD.

Adult↗
PubMed1992

Criteria for the diagnosis of ischemic vascular dementia proposed by the State of California Alzheimer's Disease Diagnostic and Treatment Centers.

Accurate diagnosis of vascular dementia is important for the recognition of underlying pathophysiology and the institution of appropriate therapy. It is also important for the determination of the incidence and prevalence of not only vascular dementia but also Alzheimer's disease (AD), since differentiating between these two entities is often problematic. The State of California Alzheimer's Disease Diagnostic and Treatment Centers (ADDTC) herein propose criteria for the diagnosis of ischemic vascular dementia (IVD). These criteria broaden the conceptualization of vascular dementia, include the results of neuroimaging studies, emphasize the importance of neuropathologic confirmation, refine nosology, and identify areas that require further research. Parallel use of the proposed definitions of "possible" and "mixed" categories in the diagnosis of both AD and IVD would ensure compatibility between the National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) criteria for AD and the ADDTC criteria for IVD. Uniform classification of subtypes of IVD will improve the generalizability of individual studies and aid in multicenter collaborations.

Brain Ischemia↗
PubMed1979

A direct role of dopamine in the rat subthalamic nucleus and an adjacent intrapeduncular area.

The subthalamic nucleus, a clinically important component of the extrapyramidal motor system, and a lateral area extending into the peduncle contain catecholamine terminals and dopamine receptors coupled to adenylate cyclase. In addition, dopamine agonists administered in vivo enhance glucose utilization in the region. Thus, neuronal function in this region is directly affected by dopamine and dopaminergic drugs.

Adenylyl Cyclases↗
PubMed1978

The cherry-red spot--myoclonus syndrome.

Three young women, 2 of them sisters, were found to have cherry-red spots at the macula when they were children. In 1 patient the spots faded before she was 20 years old. In all 3, incapacitating myoclonus and insidious visual loss developed in adolescence. Their intellect is normal and they have no gargoyle-like features. A variety of lysosomal inclusions were noted in cortical neurons in a biopsy specimen taken from 1 patient in childhood. Liver biopsy fifteen years later revealed mucopolysaccharide-like inclusions in Kupffer cells and hepatocytes. Lipofuscin bodies were abundant in neurons and hepatocytes. The patients excrete sialic acid-containing oligosaccharides not present in normal urine, suggesting a defect in degradation of glycoproteins. The specific enzymatic defect in these patients appears to be a deficiency of lysosomal neuraminidase.

Adolescent↗
PubMed1978

Dementias.

Senile dementia of the Alzheimer type is becoming one of the most common of the malignant diseases as our society ages. Currently, research has identified several pathophysiological changes, including the bihelical filament and the loss of the enzyme choline acetyltransferase from the cortex. Although genetic factors play some role in this disease, the important environmental risk factors have not yet been identified and there is, at present, no specific treatment. The second most common cause of dementia, cerebrovascular disease, produces dementia only when there is destruction of brain tissue, as in individuals who have multiple strokes or who have hypertensive vascular disease leading to multiple lacunae. In both multi-infarct dementia and in the lacunar state, hypertension appears to play a greater role than it does in other forms of vascular disease. Many of the other causes of dementia, including normal pressure hydrocephalus, CNS infections or tumors, metabolic disorders produced by thiamine or vitamin B12 deficiency or thyroid dysfunction, are often reversible. Every patient, whatever the age, with a developing dementia deserves a thorough workup to identify these treatable disorders.

Alzheimer Disease↗
PubMed1977

Reinnervation, myelination and organization of iris tissue implanted into the rat midbrain--an ultrastructural study.

The ultrastructure of autologous irides implanted into the midbrain of mature Sprague-Dawley rats was studied over a time period of 4-14 days. Most features of the normal iris still persisted throughout this time, including typical iris blood vessels and amelanotic melanocytes. At 5-4 days after implantation, the normal innervation of the implanted iris had degenerated, except for the presence of intact Schwann cells and some myelin debris. Reinnervation, beginning about the seventh day, proceeded rapidly. By the fourteenth day, extensive reinnervation of the implant was evidenced by the presence of numerous small (0.1-0.6 micrometer) and large (2-4 micrometer) non-myelinated axons ensheathed in Schwann cell cytoplasm. Axonal varicosities, filled either with dense core or clear core vesicles, formed junctions with axons. These junctions were characterized by an accentuation of areas of the axonal membrane and pre- or post-junctional thickenings; however, we did not observe typical synaptic complexes. Some large axons within the myelinated iris developed thick myelin sheaths of the peripheral nervous system (PNS) type; we believe this is the first reported instance in which myelination of central axons by Schwann cells within the brain parenchyma has been produced by the implantation of PNS elements.

Animals↗
PubMed1977

Syndrome of normal pressure hydrocephalus: possible relation to hypertensive and arteriosclerotic vasculopathy.

A patient with clinical features of idiopathic normal pressure hydrocephalus, who responded dramatically to shunting, was found a necropsy to have a severe hypertensive and arteriosclerotic vasculopathy with multiple lacunar infarcts. There was no pathological evidence of thickened leptomeninges, fibrosis of the arachnoid villi, or Alzheimer's disease. An abnormal absorption mechanism was demonstrated with cisternography and by an increase in the concentration of homovanillic acid in the cerebrospinal fluid. It is suggested that vascular changes may play an important role in the pathophysiology in some cases of normal pressure hydrocephalus.

Aged↗
PubMed1976

The catecholamine pontine cellular groups locus coeruleus, A4, subcoeruleus in the primate Cebus apella.

The distrubution of CA neurons of areas A6 and A4 was delineated in Cebus apella monkey using the fluorescent histochemical technique of Falck and Hillarp. Cytospectroscopy was utilized for CA differentiation. The noradrenergic cellular regions A6, A4, and subcoeruleus have extensively increased in size in the Cebus as compared to the rat and appear to be separate nuclear regions. Area A4 is made up of two cellular subgroups: a more abundant lateral magnocellular area with cells as large as 45 mum and a smaller medial parvocellular group where the neurons are spindle-shaped and lie within 10-100 mum of the ependyma. The neuronal processes of A4 tend to be directed towards the flocculus and paraflocculus of the cerebellum. Some processes seem to enter the ependyma and others end subependymally. The functional significance of the pontine CA neurons is discussed.

Animals↗