Search PubMed⌕ Search

Biomedical subjects

J E Graham

Publications and source records attributed to J E Graham.

53 records · Page 3Linked to original sources
PubMed1975

Clinicopathologic case reports: Optic nerve head metastasis.

A case of tumor metastasis from carcinoma of the lung directly to the cribriform plate is described. Retina and optic nerve were involved, but there was no evidence of tumor invasion of the choroid. It is postulated that the original tumor embolus lodged in a cribriform branch of the arterial circle of Zinn or in the central retinal vessels.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Adenylate cyclase from term human placenta and its regulation.

The activation of placental AC by either Mg2+ or Mn2+, in the presence and absence of NaF, followed sigmoidal saturation kinetics. Mn2+ enhanced maximally the NaF-stimulated Mg2+-dependent AC activity. The apparent Km of Mg2+-dependent AC for ATP was 0.4 mM, with and without NaF addition. GTP and GMP-P(NH)P stimulated the Mg2+-dependent AC in a dose-dependent manner with half-maximal stimulation taking place at concentrations of approximately 2 microM. In the presence of GMP-P(NH)P (10 microM) the kinetics of the AC dependence on Mg2+ ion concentration changed from sigmoidal to hyperbolic. Most of the AC activity (greater than 83 per cent) was associated with the particulate fractions of placental homogenate. For better reproducibility, the AC assay was performed using sonicated particulate fraction preparations; sonication did not alter the response of AC to stimuli to a variety of agents used in these experiments; freezing and thawing, however, obliterated the stimulation by beta-adrenergic agonists. Placental AC activity was inhibited by p-hydroxymercuriphenyl sodium sulphonate in a dose-dependent fashion, and the inhibition was reversed by dithiothreitol. Mg2+-dependent AC was inhibited by 0.5 mM phenylhydrazine (95 per cent). Mg2+-dependent AC activity was responsive to stimulation by epinephrine, without and with GTP addition, with half-maximal stimulation taking place at a concentration of 2 microM. The stimulatory effect of epinephrine was blocked by propranolol in a dose-dependent manner but was not blocked by phentolamine. Oestrone, oestradiol-17 beta, 2-hydroxyoestreone, 2-hydroxyoestradiol-17 beta, dehydroepiandrosterone sulphate, and progesterone, as well as oxytocin, did not alter either the basal or GMP-P(NH)P-stimulated Mg2+-dependent AC activities. Preincubation of 20 000 g particulate fraction with either NaF or GMP-P(NH)P, followed by washing, resulted in preparations that remained stimulated without the requirement of any further additions.

Adenylyl Cyclases↗
PubMedDate not supplied

Prevalence of cognitive impairment and dementia as defined by neuropsychological test performance.

The Canadian Study of Health and Aging (CSHA) provided a population-based estimate of the prevalence of dementia of 8% for those aged 65 and older. Other studies have produced both higher and lower prevalence estimates. Factors that may contribute to these differences include: the use of or the reliance on neuropsychological testing, the consideration of functional impairment as a criterion for dementia and the inclusion of the category of cognitive impairment without dementia in the diagnostic classification. We examined the impact of these methodological factors by reanalyzing the CSHA database for those individuals who completed neuropsychological testing. If the diagnosis of dementia required only impaired neuropsychological test performance, there was an increased prevalence of dementia relative to the clinical consensus diagnosis, but including the requirement of functional impairment for dementia reduced this discrepancy. The findings illustrate the need for clear operationalization of diagnostic criteria for cognitive impairment and dementia in neuroepidemiological studies.

Aged↗
PubMedDate not supplied

An algorithmic approach to the differential diagnosis of dementia.

The careful definition of cases is fundamental to diagnosis and to any study of cognitive, behavioural and functional problems in dementia. This paper presents an algorithmic approach which mimics a crucial component of diagnostic decision-making; symptoms and signs do not occur independently, but are conditioned on each other. First, we examine whether the conditioned items can be assembled to yield a differential diagnosis of dementia which corresponds to clinical diagnoses, and second, we explore whether subjects whose algorithmic profiles do not fit the clinical diagnoses form new discernable patterns. Such a technique offers two advantages: it allows for the development of validation protocols which are crucial to epidemiological studies, and it allows for the analysis of new patterns of signs and symptoms for emerging criteria of dementia subtypes. This approach has the potential to refine and enhance criteria for the differential diagnosis of dementia and to have an impact on case identification and assessment, particularly in large epidemiologic studies.

Algorithms↗
PubMedDate not supplied

Symptoms and signs in dementia: synergy and antagonism.

This paper addresses the synergy and antagonism between symptoms and signs among 2,914 elderly Canadians diagnosed in 15 categories, including no cognitive impairment, cognitive impairment but no dementia, mild, moderate and severe forms of Alzheimer's disease and vascular dementia, 4 subtypes of possible Alzheimer's disease, Parkinson's dementia, unspecified other dementias and unclassified dementias Attention is paid to the relationships between symptoms and signs rather than conventional analyses which assume independent signs. We demonstrate that dementia progression and specific aetiologies have characteristic patterns of decline and destruction from the strong synergy that exists between symptoms and signs among the population with no cognitive impairment. These findings have potential implications for the incorporation of new diagnostic criteria into existing databases.

Aged↗