PubMed Health⌕ Search

Biomedical subjects

K Graham

Publications and source records attributed to K Graham.

At least 109 records · Page 6Linked to original sources
PubMed1988

Analyses of frequency of infection, specific infectivity, and prion protein biosynthesis in scrapie-infected neuroblastoma cell clones.

Scrapie, a spongiform encephalopathy of sheep and goats, is caused by a poorly understood transmissible agent in which no nucleic acid has been conclusively identified. Biochemical characterization of agent derived from animal tissues has not been precise because of the tenacious association of the agent with tissue components. As an approach toward obtaining homogeneous preparations of agent generated in vitro, we cloned scrapie-infected neuroblastoma cells. By frequency analysis, nearly every cell in expanded cultures contained scrapie agent. We also analyzed cell-dose infectivity relationships and developed a standard curve which allowed various cultures to be compared. Since a proteinase K (PK)-resistant form of a protein designated prion protein (PrP) has been found in partially purified preparations of scrapie agent from infected animal spleens and brains, we sought to identify this protein in cell cultures. No PK-resistant PrP was found in infected or uninfected cultures, although the PK-sensitive PrP was readily detected. These results suggested that PK-resistant PrP may not be an essential component of the infectious scrapie agent.

Animals↗
PubMed1988

Limitation of myocardial infarction by early infusion of recombinant tissue-type plasminogen activator.

In a double-blind randomized trial involving five Sydney hospitals and the city ambulance paramedical service, 145 patients with a first evolving myocardial infarction and with onset of pain less than 2.5 (mean 1.9 +/- 0.5 [SD]) hr previously were allocated to intravenous infusion of 100 mg recombinant tissue-type plasminogen activator (rt-PA) or placebo over 3 hr. The groups at entry were similar. At assessment 21 days later, left ventricular ejection fraction measured both by contrast and radionuclide ventriculography was higher in the rt-PA compared with the placebo group (61 +/- 13%, n = 64, vs 54 +/- 14%, n = 62, contrast, 2p = .006; 52 +/- 13%, n = 66, vs 48 +/- 13%, n = 62 isotope, 2p = .08). This indicates limitation of myocardial infarction by rt-PA.

Adult↗
PubMed1987

Prediction of stroke rehabilitation outcome from psychologic screening.

A psychologic screening battery, including assessment of perceptuomotor, attentional, memory, and emotional functioning, was presented to 134 patients at initiation of stroke rehabilitation. Significant differences in performance on tests based on side of involvement of stroke were noted. Poorer performance on sensory suppression errors and motor persistence score was found for individuals with left-side involvement and the opposite for word fluency score. Examining subjects with left- and right-side involvement separately using stepwise multiple regression, psychologic tests were able to account for 55% and 42%, respectively, of the variance in discharge outcome, as measured by the Barthel Index. Accounting for variance associated with change in Barthel Index score during rehabilitation proved more difficult, with R2 values of 0.14 and 0.07, respectively. Motor persistence score and half-hour recall proved to be the strongest of the psychologic tests in predicting rehabilitation outcome.

Adult↗
PubMed1986

Identifying and measuring alcohol abuse among the elderly: serious problems with existing instrumentation.

Existing instruments for identifying and measuring alcohol abuse are inappropriate for use with elderly populations because of differences between the younger populations on which these measures were standardized and the elderly. Five domains used in measuring alcohol abuse--level of consumption, alcohol-related social and legal problems, alcohol-related health problems, symptoms of drunkenness or dependence and self-recognition of the problem--and the extent to which these domains (as currently measured) apply to elderly populations are discussed. Some recommendations for developing instruments suitable for the elderly are made.

Aged↗
PubMed1985

Short-latency interactions among dorsomedial medullary inspiratory neurons in the cat.

Pairs of inspiratory neurons were recorded extracellularly with microelectrodes whose tips were close to one another (100 to 300 microns) in the ventrolateral region of the nucleus tractus solitarius. Each neuron was identified as an R beta or an R alpha type using lung volume manipulations. Those neuron pairs whose cross-correlation histograms indicated a positive interaction were tested for interneuronal connections by antidromic activation of one neuron of the pair combined with further cross-correlation. Three pairs of R alpha/R alpha, three pairs of R alpha/R beta, and three pairs of R beta/R alpha neurons were tested in this manner. One pair of R alpha/R alpha neurons and one pair of R beta/R beta neurons showed evidence of interneuronal interaction. We concluded that although the short-term synchronization in the firing patterns of these neurons was due mostly to common excitation of both neurons, interneuronal interactions were also responsible.

Animals↗
PubMed1985

Analysis of an addictions treatment system.

A treatment system consisting of an assessment/referral service, a detox, a mission, a hospital recovery unit, and three recovery homes was examined using a retrospective client-tracking approach over 1 year. There were 4,187 admissions to the system accounted for by 1,522 individuals; system users tended to be males, unmarried, unemployed, and in their 30s and 40s. The best predictor of readmission to the system after treatment was prior system use. Use patterns and referral data indicated that perceived gatekeepers (i.e., detoxication and assessment services) were not consistently coordinating the system and that more socially stable clients appeared to be more likely to be involved with non-addiction specific services (i.e., medical, general counselling).

Alcoholism↗
PubMed1984

Enzyme-linked lectinosorbent assay (ELLA) for detecting Bacillus anthracis.

An enzyme-linked lectinosorbent assay (ELLA) has been developed for the rapid identification of Bacillus anthracis. Using two different lectin-conjugates, the ELLA test can differentiate Bacillus anthracis from closely related species, such as Bacillus cereus and Bacillus cereus var. mycoides, in approximately two hours. In addition to having high specificity, the test can also detect small numbers of the bacterium.

Bacillus↗
PubMed1984

Vasoactive intestinal polypeptide stimulation of prolactin release and renin activity in normal man and patients with hyperprolactinaemia: effects of pretreatment with bromocriptine and dexamethazone.

Vasoactive intestinal polypeptide (VIP) was infused into normal volunteers and patients with hyperprolactinaemia. Heart rate increased from 62 +/- 3 to 75 +/- 3 beats min-1 (P = 0.001) in controls and from 70 +/- 2 to 78 +/- 3 beats min-1 (P = 0.001) in hyperprolactinaemics. Similarly, haematocrit increased from 38 +/- 2 to 44 +/- 1% (P = 0.001) and from 40 +/- 1 to 43 +/- 2% (P = 0.002) and plasma renin activity from 910 +/- 59 to a peak of 3344 +/- 282 pg ml-1 h-1 (P = 0.001) and from 1577 +/- 671 to a peak of 4954 +/- 1364 pg ml-1 h-1 (P = 0.001) in the two groups, respectively. Prolactin concentrations rose in the control group only, from 134 +/- 11 to a peak of 377 +/- 35 mU 1(-1) (P = 0.001), whilst in the hyperprolactinaemics little change occurred from the pre-infusion concentration of 3873 +/- 2179 reaching a peak of 3998 +/- 2347 mU 1(-1) (P greater than 0.07). In separate studies, the normal subjects were pretreated with either bromocriptine or dexamethazone. Dexamethazone did not alter any parameter of the response to VIP. Bromocriptine did not affect the heart rate, haematocrit or renin response to VIP but clearly inhibited the rise in prolactin which remained at unmeasurable concentrations throughout the infusion.

Adenoma↗
PubMed1982

Ultrasonic imaging of the coronary arteries in open-chest humans: evaluation of coronary atherosclerotic lesions during cardiac surgery.

We explored techniques that would allow the surgeon to localize coronary artery lesions demonstrated angiographically or to supplement angiographic information in patients who are undergoing coronary artery bypass procedures by intraoperative scanning of the coronary arteries using ultrasound. A 9-MHz electronically focused water-path ultrasound scanner was first used to image the coronary arteries in three anesthetized, open-chest sheep. In a subsequent study, 10 human subjects undergoing cardiac surgery for valve replacement who had normal coronary angiograms were scanned during heart surgery to provide images of normal coronary arteries. The ultrasound probe was sterilized with gas and placed directly on the beating heart by the surgeon. In the third phase of this study, 21 patients with coronary artery disease were scanned and the ultrasonic appearance of their imaged coronary lesions was compared to independently interpreted angiographic estimates of percent obstruction, with close correlation (r = 0.91). The ultrasound scan could be used to identify lesions in vessels beyond proximal occlusions, which are not visualized well angiographically, and could localize the site of lesions to determine placement of saphenous vein bypass grafts. This new technique may provide a method for evaluating coronary atherosclerotic lesions during coronary artery surgery and aid decisions regarding placement of saphenous vein grafts.

Animals↗
PubMed1981

Band 1 and voltage-sensitive Na+ channels are not codistributed in cultured rodent neuronal cells.

The relationship of the mouse nervous system specific band 1 protein to the putative high molecular weight component of the Na+ channel was investigated using antibody to band 1. Morphologic differentiation of cultured neuroblastoma cells has been reported to increase the quantity of the putative Na+ channel high molecular weight component. Morphologically differentiated clone NB2a neuroblastoma cells have 2-3 times the amount of band 1 and 1.5 times the relative rate of synthesis of band 1 as undifferentiated cells. The anti-band 1 serum reacts with both adult mouse and rat brain but not 3 cultured rat neuronal lines known to have active Na+ channels. Thus either band 1 is not a component of the Na+ channel or individual cultured murine neuronal lines has distinct macromolecular Na+ channels.

Animals↗
PubMed1981

The regularity and interrelation of respiratory and cardiac rhythms at rest and during exercise.

One of the hypotheses to account for the increase in the drive to ventilation in exercise mediated by the peripheral chemoreceptors is that there is an improved linkage between breathing rate and lung to carotid body circulation time, such that peaks of arterial carbon dioxide arrive during a subsequent inspiration thereby stimulating ventilation. This study was designed to examine the mechanisms which may underlie the improved linkage. Auto- and cross-correlations of breathing and heart rhythms in volunteers at rest and during exercise showed an increased regularity of the rhythms but not entrainment between the rhythms. Although the increased regularity of the cardiac rhythm should promote a decrease in the variability of the lung to carotid body circulation time, the lack of entrainment shows that if there is an improved linkage of breathing and lung to carotid body circulation time, it is not by a coupling of heart rhythm to breathing rhythm.

Female↗
PubMed1980

Relevance of colour vision and diabetic retinopathy to self-monitoring of blood glucose.

A study was performed to determine the effect of colour vision defects and diabetic retinopathy on diabetic patients' ability to use a visual method of measuring their own blood glucose concentrations. Forty-eight diabetics whose colour vision and retinal status was assessed by an ophthalmologist carried out 311 blood glucose estimations using oxidase-peroxidase test strips which were then compared with laboratory values. There was a trend towards poor performance with advancing age but neither colour vision nor diabetic retinopathy had a significant effect on patients' ability to use this visual method of estimating blood glucose concentrations. The vast majority of diabetics who will benefit from being able to monitor their own blood glucose control should have no difficulty in using a visual method of testing, even if they do have defects of colour vision.

Adolescent↗
PubMed1980

Aggression and barroom environments.

Systematic observation of a wide variety of Vancouver barrooms showed that aggression was highly predictable on the basis of situational variables and identified a drinking environment highly associated with aggression.

Adult↗