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Biomedical subjects

H Tuokko

Publications and source records attributed to H Tuokko.

At least 37 records · Page 2Linked to original sources
PubMed1995

Detection of acute measles infections by indirect and mu-capture enzyme immunoassays for immunoglobulin M antibodies and measles immunoglobulin G antibody avidity enzyme immunoassay.

An avidity test for measles IgG was developed and applied to the study of IgG immunoglobulin maturation kinetics in follow-up sera from 12 patients with known acute primary and convalescent measles and sera from blood donors. The avidity of the IgG anti-measles responses was measured using the 8 M urea elution technique, the results being expressed as the percentage ratio between the test readings for eluted and noneluted samples. The IgG avidity results were compared with those of indirect and mu-capture IgM enzyme immunoassays. This test was capable of detecting low-avidity antibodies at the acute phase of measles up to 7 weeks, and increasing avidity through immunosaturation during the convalescent phase. The avidity in these samples did not reach the level found in the samples of the blood donors under the follow-up time. Although a limited number of serum samples was examined, the results suggest that the measles IgG avidity test is a powerful tool for differentiating primary measles infection from the convalescent phase.

Acute Disease↗
PubMed1995

Neuropsychological detection of dementia: an overview of the neuropsychological component of the Canadian Study of Health and Aging.

As part of the Canadian Study of Health and Aging (CSHA), a battery of neuropsychological measures was administered to 1879 participants. Participants who received neuropsychological evaluations were selected from an age-stratified random sample on the basis of scores on a cognitive screening tool, the Modified Mini-Mental State Examination (3MS). Seventy-five percent of the sample seen for neuropsychological evaluation scored between 50 and 77 on the 3MS and 25% of the sample scored 78 or over. This paper provides a descriptive summary of the methodological basis of the neuropsychological component of the CSHA. The findings indicated that differences existed between participants administered the battery in English or French in terms of refusal rates and diagnoses of dementia. Cursory examination of the utility of the battery indicated that the battery was tolerated well by both the participants and the psychologists involved with the study and that measures of memory functioning were central to diagnostic decision-making. The relations between neuropsychological, preliminary medical and consensus diagnoses were examined and indicated that neuropsychological information influenced diagnostic decision-making. The neuropsychology component of the CSHA is a rich source of information on persons aged 65 years and older in Canada.

Aged↗
PubMed1995

Color- and picture-word Stroop tests: performance changes in old age.

The Stroop test comes in different variations, but all of them index performance on a basic task, like color or picture naming, when it is carried out by itself versus when it is performed in the presence of conflicting or incongruent stimuli. The present study examined the hypothesis that Stroop interference--the cost of performing one task in the presence of another--is a general as opposed to a test-specific index of cognitive flexibility. A second goal was to examine changes in Stroop test performance in old age. A group of 129 healthy older adults (> or = 65 years of age) were assessed on the color- and picture-word Stroop test, as well as on a battery of neuropsychological tests. Subjects' performance on each card of both Stroop tests, and various derived (differences and ratios) scores, were used to prepare age-group norms. The use of the norms is illustrated with findings from previous studies. Regression analyses showed age-changes in several aspects of Stroop test performance. Hierarchical multiple regression analyses, and causal modeling showed an age effect on Stroop interference only on the picture-word test but not on the color-word test. Exploratory factor analysis of the Stroop data and the neuropsychological test data revealed different factor loadings for the color- and picture-word test. The combined findings suggest that the color- and picture-word Stroop test measure different cognitive functions, at least in old age.

Aged↗
PubMed1995

Risk of acute otitis media in relation to the viral etiology of infections in children.

We carried out a prospective case-control study to analyze the etiology of respiratory tract infections among children with and without acute otitis media (AOM). Of the 658 patients admitted to our hospital during the period concerned, 197 (29.9%) had AOM, and for each such child the next patient of the same age was chosen as a control. The total number of virologically positive samples was 99 (50.3%) among the patients with AOM vs. 93 (47.2%) among the controls. The only etiologic agent that was more common in the patients with AOM was respiratory syncytial virus, found in 31 cases vs. 15 controls (relative risk [2.27]; 95% confidence interval, 1.18-4.35; P < .02). Our results confirm earlier observations from uncontrolled studies regarding the fact that respiratory syncytial virus is especially liable to cause AOM. Since respiratory syncytial virus is causing predictable epidemics, this finding could be useful for the timing of efforts to prevent AOM in young infants.

Acute Disease↗
PubMed1995

An examination of driving records in a dementia clinic.

The driving records of 249 persons referred to an outpatient dementia clinic were examined retrospectively to assess the specificity of the association between diagnosed dementia and increased traffic accidents. The clinic patients were divided into two groups: those who met criteria for dementia and those who did not. For each group, control subjects matched on age, gender, and location of residence were randomly selected from the records of all drivers in the province. The dementia sample had approximately 2.5 times the traffic crash rate of their matched control sample. The not-demented sample had approximately 2.2 times the traffic crash rate of their matched control sample. These individuals exhibited a variety of psychiatric, neurological, and medical conditions which could have affected their driving, and multiple medical problems were often present. Further clarification of the characteristics of "high risk" drivers is required if effective strategies for maximizing independence while minimizing the risk of traffic crashes are to be realized.

Accidents, Traffic↗
PubMed1995

Differential effects of human and animal insulin on the responses to hypoglycemia in elderly patients with NIDDM.

Recent studies suggest that insulin-dependent diabetes mellitus patients switched from animal to human insulin may have decreased awareness of hypoglycemic warning symptoms. The risk of severe or fatal hypoglycemia associated with the treatment of diabetes increases with age. We conducted these studies to determine if awareness of hypoglycemic warning symptoms was greater with animal than with human insulin in elderly patients with diabetes. Nonobese elderly patients with non-insulin-dependent diabetes mellitus (NIDDM) (n = 13; age, 74 +/- 1 years; body mass index, 26.6 +/- 0.7 kg/m2) underwent paired hyperinsulinemic glucose clamp studies (insulin infusion rate 60 mU.m-2.min) in random order. In one study, regular human insulin was infused, and in the other study, regular beef/pork insulin was infused. In all studies, plasma glucose was decreased from fasting levels to 5 mmol/l during the first 60 min and was then allowed to fall to 4.4, 3.8, 3.3, and 2.8 mmol/l in each subsequent hour. Subjects were blinded as to which study they were undergoing. In each study, a hypoglycemic symptom checklist was administered, and counterregulatory hormones were measured every 15 min. Neuropsychological tests were performed every hour. Counterregulatory hormone responses to the two insulin preparations were similar. Autonomic (P < 0.05) and neuroglycopenic (P < 0.01) symptom scores were significantly higher during the beef/pork insulin studies. The responses on the neuropsychological tests were not significantly different. We conclude that beef/pork insulin results in greater awareness of hypoglycemic warning symptoms than does human insulin in elderly patients with NIDDM.

Aged↗
PubMed1994

Neuropsychological deficits, caregivers' perception of deficits and caregiver burden.

OBJECTIVE: We tested three hypotheses about the effects of perceived and actual patient deficits on caregiver burden: (1) objective patient deficits directly influence caregiver burden; (2) caregiver burden is the result of caregiver perceptions of patient deficits; (3) objective patient deficits influence caregiver burden indirectly by determining perceived deficits. DESIGN: Causal modeling. SETTING: A hospital-based out-patient diagnostic clinic. PARTICIPANTS: An elderly sample (n = 136) referred to a diagnostic dementia clinic and their caregivers. MEASUREMENTS: Neuropsychological tests of patient functioning, a measure of patient mood (the Geriatric Depression Scale), caregiver perceptions of patient functioning, and a measure of caregiver burden (the Burden Interview). RESULTS: The Geriatric Depression Scale and neuropsychological battery-based indices of functioning were not predictive of caregiver burden. Caregiver perceptions of patient dysphoria, and of everyday functioning skills were related to burden. Caregiver perceptions of patient memory, self-care, and language skills were unrelated to caregiver burden. CONCLUSIONS: The results are consistent with the Lazarus and Folkman model of stress and coping; the caregiver's perceptions of the patient's functioning were the most important determinants of caregiver burden. Objective patient deficits influenced caregiver burden indirectly by influencing caregiver perceptions of patient deficits. These findings suggest that practitioners attempting to assess and manage caregiver burden should attend to the caregivers' perceptions of patient mood and everyday functioning. The relationship of caregiver appraisals with actual patient deficits also sheds light on the nature of caregiver stress.

Aged↗
PubMed1994

Altered responses to hypoglycemia of healthy elderly people.

Many elderly people are treated with medications or are subjected to diseases which can cause hypoglycemia. We conducted the following studies to assess whether alterations in counterregulatory hormone release, decreased awareness of warning symptoms or alterations in psychomotor performance might increase the susceptibility of the elderly to hypoglycemia. Healthy, nonobese young (n = 10, age < 30) and old (n = 9, age > 65) subjects underwent paired hyperinsulinaemic clamp studies (insulin infusion rate 60 mU/m2.min). In the control study, glucose was kept at 5.0 mmol/L for 5 h. In the hypoglycemic study, glucose was kept at 5 mmol/L for 1 h and was lowered in stepwise fashion to 4.4, 3.8, 3.3, and 2.8 mmol/L in each subsequent hour. Subjects were blinded as to which study they were undergoing. Counterregulatory hormones were measured and a hypoglycemic symptom checklist was administered every 15 min in each study. Neuropsychological tests were performed at regular intervals. The glucose threshold for release of counterregulatory hormones was defined as the glucose level at which the values during the hypoglycemic study first exceeded values during the control study by 2 SD. The glucose threshold for glucagon and epinephrine release was higher in the young (approximately 3.3 mmol/L) than the old (approximately 2.8 mmol/L) and the epinephrine responses to hypoglycemia were also greater in the young. The threshold for release of GH (approximately 3.3 mmol/L) and norepinephrine and cortisol (approximately 2.8 mmol/L) was similar in each age group, as was the magnitude of release of these hormones. Although the variance in symptoms scores was large, the elderly appeared to have reduced awareness of the autonomic but not neuroglycopenic symptoms of hypoglycemia. There was no difference between young and old in the effect of hypoglycemia on neuropsychologic tests. We conclude that healthy elderly people may have impaired release of glucagon and epinephrine in response to hypoglycemia and reduced awareness of the autonomic symptoms of hypoglycemia.

Adult↗
PubMed1994

Counterregulatory hormone responses to hypoglycemia in the elderly patient with diabetes.

In patients with non-insulin-dependent diabetes mellitus (NIDDM), the risk of severe or fatal hypoglycemia associated with the use of oral agents or insulin increases exponentially with age. We conducted this study with the hypothesis that this increased susceptibility to hypoglycemia is caused by alterations in release of counterregulatory hormones and psychomotor performance during hypoglycemia. Ten healthy nonobese elderly subjects (74 +/- 1 years of age; body mass index, 24.5 +/- 0.6 kg/m2) and 10 nonobese elderly NIDDM subjects (72 +/- 1 years of age; body mass index, 25.6 +/- 0.9 kg/m2) underwent two hyperinsulinemic glucose clamp studies (insulin infusion, 60 mU.m-2 x min-1). In the control study, glucose was maintained at 5 mM for 5 h; in the hypoglycemic study, glucose was kept at 5 mM for 1 h and then lowered in a stepwise fashion to 4.4, 3.8, 3.3, and 2.8 mM in each subsequent hour. At regular intervals in each study, neuropsychological tests were performed, counterregulatory hormones were measured, and a hypoglycemic symptom questionnaire was administered. At a glucose level of 2.8 mM, NIDDM patients had reduced incremental glucagon (normal subjects, 114 +/- 18 ng/l; NIDDM subjects, 63 +/- 9 ng/l; P < 0.05) and growth hormone responses (normal subjects, 13.8 +/- 1.0 micrograms/l; NIDDM subjects, 7.0 +/- 2.0 micrograms/l; P < 0.01) and increased epinephrine (normal subjects, 925 +/- 198 pM; NIDDM subjects, 4175 +/- 824 pM; P < 0.001) and cortisol responses (normal subjects, 291 +/- 49 nM; NIDDM subjects, 524 +/- 92 mM; P < 0.05). Symptom scores were similar in both groups at all levels of glycemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Respiratory viral and Mycoplasma infections in patients hospitalized for acute asthma.

We evaluated the involvement of viral and Mycoplasma infections in severe attacks of asthma in 112 adult patients admitted to Oulu University Central Hospital for an exacerbation of asthma, during a period of one year. The total number of admissions was 151, and specimens for viral identification were collected from 142 of these. Although the methods for diagnosis of rhinoviruses and coronaviruses were lacking, the diagnosis of a viral or Mycoplasma infection was confirmed in 41 patients (29%) by one or more of the three methods; viral serology, viral culture from a throat wash or viral antigen detection from a nasopharyngeal aspirate. Thirty six of these patients (88%) with confirmed infection also had symptoms suggestive of a viral infection. We conclude that viral and Mycoplasma infections are so often involved in severe asthma attacks of adults that they may play an important role in the induction of such attacks.

Acute Disease↗
PubMed1993

The differential diagnosis of adult onset metachromatic leukodystrophy and early onset familial Alzheimer disease in an Alzheimer clinic population.

Clinical differentiation between forms of progressive dementia can prove difficult, particularly when relatively rare forms of dementia are involved. Factors such as family history of dementia, age at onset, presenting features such as personality change, cognitive deficits, psychiatric symptoms, and clinical course (progressive deterioration; retention of skills over time) may prove useful for directing investigations to identify underlying pathology and genetic implications. This is illustrated by two patient reports. Each patient had the onset of memory/behavioral problems at approximately age 40 years, was initially given a psychiatric, non-dementing diagnosis, and had a positive family history for early onset behavioral and memory problems. After longitudinal assessment, the diagnosis of Alzheimer disease was confirmed at autopsy in one patient and a diagnosis of familial, adult-onset metachromatic leukodystrophy in the other.

Alzheimer Disease↗
PubMed1993

The effect of improved glycemic control on cognitive functions in the elderly patient with diabetes.

BACKGROUND: A number of studies have found that cognitive function is impaired in elderly patients with non-insulin dependent diabetes mellitus (NIDDM) when compared with age-matched non-diabetic controls. In addition, it has been reported that elderly NIDDM patients who have poor glycemic control have a greater impairment in cognition that elderly NIDDM patients with good control. We conducted the following prospective study to determine if improved glycemic control would result in an improvement in cognitive function in elderly patients with NIDDM: METHODS: Sixteen untreated elderly patients with NIDDM underwent a battery of neuropsychologic tests on two occasions, separated by at least two weeks. They were then started on an oral hypoglycemic agent. After they had been on a stable dose of medication for 6 months the neuropsychologic tests were repeated. RESULTS: Fasting glucose decreased significantly after treatment (before: 13.8 +/- 1.2 mmol/l; after 8.4 +/- 0.4 mmol/l, p < .01). After 6 months of treatment patients had improvement in their scores on the Grooved Pegboard, Trail Making-Part A, Stroop-Word Naming, Cued Recall and Picture Arrangement tests (all p < .05). CONCLUSIONS: Improved glycemic control in the elderly patient with NIDDM may have beneficial effects on selective areas of cognition.

Affect↗
PubMed1992

The Clock Test: a sensitive measure to differentiate normal elderly from those with Alzheimer disease.

OBJECTIVE: To examine the clinical utility of the Clock Test for identifying dementia. DESIGN: Group comparisons. SETTING: A hospital-based out-patient diagnostic clinic. PATIENTS: Volunteer sample of elderly individuals (normal elderly, NE, n = 62) and a referred sample of probable Alzheimer Disease (AD, n = 58) patients meeting NINCDS-ADRDA criteria. MAIN OUTCOME MEASURE: The Clock Test is composed of three components: Clock Drawing, Clock Setting, and Clock Reading. A detailed scoring system for qualitative as well as quantitative evaluation of Clock Drawing errors was used. Five time settings, varying in level of complexity, were used to evaluate Clock Setting and Clock Reading. RESULTS: The groups differed significantly on Clock Drawing, Clock Setting, and Clock Reading (P less than 0.001). On Clock Drawing, the AD group made significantly more errors of omission and misplacement of numbers than the NE group (P less than 0.001). Using cut-off scores derived to maximize separation between the groups to define deficits in performance, the sensitivity and specificity for the diagnosis of AD of Clock Drawing, Clock Setting, and Clock Reading were 92% and 86%, 87% and 97%, 92% and 85%, respectively. Using a criterion of deficits on two or more of the three components, sensitivity and specificity increased to 94% and 93%, respectively. CONCLUSIONS: Deficits on clock drawing in AD may be reflective of a generalized disturbance in the conceptualization of time rather than constructional apraxia, per se. The functionally relevant components of Clock Setting and Clock Reading combined with Clock Drawing make the Clock Test particularly useful as a screening and research tool for AD.

Aged↗
PubMed1991

The role of physical attractiveness in the assessment of elderly patients.

The degree to which patient physical attractiveness affects judgements of professionals and relatives of patients as well as the psychosocial adjustment of elderly was investigated within the context of a longitudinal quasi-experimental design. In contrast to previous analogue and cross-sectional research, no evidence was found to support the contention that physical attractiveness has a potent impact on any of the variables under study.

Aged↗
PubMed1991

Cued recall and early identification of dementia.

The early detection of dementia carries implications for clinical management for patients and their families and is of utmost concern if an effective pharmacological treatment is to be found. The utility of an enhanced cued recall paradigm for predicting dementia in a group of elderly subjects was examined. Forty-five subjects referred for clinical evaluation who did not meet the criteria for dementia at initial assessment were reassessed 12-18 months later. Eighteen of these subjects were diagnosed as having possible or probable Alzheimer Disease at reassessment and the diagnostic status of 27 remained unchanged. At initial assessment the 'change' group performed more poorly than the 'no change' group on measures of retrieval, acquisition and retention derived from the cued recall procedure. As would be expected, the performance of the 'no change' group remained stable over time whereas the performance of the 'change' group deteriorated, resembling the performance of a group of subjects with mild possible or probable Alzheimer disease. When the sensitivity and specificity of the memory variables were examined, the retrieval measure (i.e., free recall) appeared most useful as an early predictor of dementia. Continued longitudinal evaluations of subjects with questionable dementia are needed to address more fully the natural history of early memory changes associated with dementia.

Aged↗
PubMed1990

Viral infections and recurrences of febrile convulsions.

To determine whether complicated febrile seizures occur more often in children with a proven viral infection, we performed viral examinations on 144 children with febrile convulsions, of whom 112 had simple and 32 had complicated seizures. A diagnosis of virus infection was verified in 46% of the former patients and 53% of the latter. Three adenoviruses, one parainfluenza virus type 2 and one type 3, one respiratory syncytial virus, one echovirus type 11, one herpes simplex virus type 2, and one influenza B virus were isolated from the cerebrospinal fluid. A simple febrile convulsion occurred in seven children with a positive cerebrospinal fluid viral isolation, and two had a complex febrile seizure. In a follow-up of 2 to 4 years (mean 3.3 years), 21 of the 107 children with simple seizures (19.6%) and 3 of the 32 children with complicated seizures (9.4%) had recurrent febrile seizures. The children with positive evidence for a viral infection, even with a virus isolated from the cerebrospinal fluid, had no more recurrences than those without any proven viral infection. We conclude that children with a proven viral infection have no worse prognosis than those without.

Cerebrospinal Fluid↗
PubMed1990

18Fluorodeoxyglucose positron emission tomography studies in presumed Alzheimer cases, including 13 serial scans.

Positron emission tomographic (PET) data on local cerebral metabolic rates for glucose (LCMR) are reported for 32 regions of interest (ROI)s in cross-sectional studies on 57 patients with clinically diagnosed Alzheimer's disease (AD) and 20 neurologically normal controls, and in serial studies on 13 of the AD cases, including a familial, young-onset case where the diagnosis has been confirmed at autopsy. Extensive psychological testing was done on all the AD cases. Almost all cortical regions showed a significant decline in LCMR with age in the control subjects. There were the expected cortical metabolic deficits in AD and the serial studies showed a general increase in such deficits over time in 12 of the 13 cases. The regions showing the greatest declines with time in serial studies are the same as those showing the most severe deficiencies in cross-sectional studies. The young-onset case did not show a greater rate of metabolic decline than many of the older cases studied. Results on individual psychological tests tended to correlate with metabolic rates in multiple, rather than single, cortical regions, suggesting intact neuronal networks are required for good performance. The correlations with cortical metabolic activity found were of a sign indicating that the higher the metabolic rates and the better the left:right asymmetry index, the better was the performance.

Aged↗