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Biomedical subjects

C Steele

Publications and source records attributed to C Steele.

At least 73 records · Page 4Linked to original sources
PubMed1989

Conceptual and methodological issues regarding the epidemiology of iron deficiency and their implications for studies of the functional consequences of iron deficiency.

This paper reviews the measures of iron status (hemoglobin, hematocrit, mean corpuscular hemoglobin concentration, mean cell volume, free erythrocyte protoporphyrin, serum iron, transferrin saturation, and serum ferritin) that are potentially available for inclusion in field studies of the relationship between iron and mental performance. The characteristics of these measures (sensitivity to iron status, specificity to iron, and diurnal and day-to-day variability) are reviewed and the implications of choice of variable for the design, analysis, and interpretation of studies are discussed. Brief consideration is given to the question of confounding variables and to sources of both false-positive and false-negative conclusions. The explicit message of the paper is that there is no perfect choice of measure of iron status but, given explicit definition of the research question, there are preferred choices that can most effectively combine the choice of variable and the design of the study.

Adult↗
PubMed1989

Neuropathology of aminergic nuclei in Alzheimer's disease.

In order to comprehensively evaluate pathological involvement of the locus coeruleus (LC) and cortically projecting raphe nuclei in Alzheimer's disease (AD), we have recently completed a study (Zweig, et al., 1988) in which numbers of neurons containing neuromelanin within the LC and large nucleolus-containing neurons within the dorsal raphe nucleus (DR) and the central superior (raphe) nucleus (CSN) were determined in 25 cases of AD and 12 age-matched controls. Numbers of neurofibrillary tangles (NFTs) within these regions were also counted. Pathological results were compared with clinical data, including psychiatric evaluations, available for 21 of the AD cases. Neuronal loss in AD cases was most severe within LC at mid level (p less than .01) and within DR, caudally (p less than .05). Counts of NFTs within LC were also highest at mid level (p less than .05) in comparison with caudal level). Neuronal loss was not demonstrated within CSN, although NFTs were abundant within this nucleus. At individual levels, neuronal and NFT counts did not correlate. Relative severity of neuronal loss or NFTs was usually consistent from level to level within nuclei; internuclear correlations were weaker. Cases of AD complicated by depression had significantly fewer neurons at mid LC and rostral CSN levels than nondepressed cases (p less than .05). There was also a trend (nonsignificant) suggesting increased neuronal loss at all levels of LC and DR in depressed cases. Neuronal loss correlated negatively with age, particularly within LC. NFT counts correlated negatively with duration of illness, particularly within DR. As all but 3 individuals had severe dementia, NFT counts may reflect rate of progression of disease. Neuronal loss and NFTs frequently occur in the LC and cortically projecting raphe nuclei in AD (Curcio and Kemper, 1984, Hirano and Zimmermann, 1962, Ishii, 1966, Marcynuik et al., 1986, Yamamoto and Hirano, 1985, Bondareff and Mountjoy, 1986, Iverson et al., 1983, Mann et al., 1985, Tabaton et al., 1986). We have recently completed a comprehensive evaluation of pathological involvement of the LC, the DR, and the CSN in a series of aged controls and AD patients for whom detailed clinical information, including psychiatric evaluations, were available (Zweig et al., 1988). This report summarizes the findings of that study.

Aged↗
PubMed1988

The neuropathology of aminergic nuclei in Alzheimer's disease.

Neuronal loss and the presence of neurofibrillary tangles (NFTs) within aminergic nuclei were examined in a series of patients with Alzheimer's disease (AD). Neuromelanin-containing neurons within the locus ceruleus and large nucleolus-containing neurons within the dorsal raphe nucleus and the central superior (raphe) nucleus were counted in 25 patients with AD and in 12 age-matched control subjects. Numbers of NFTs were quantified in the same regions. Counts were compared with clinical data, including psychiatric evaluations, available for 21 of the patients with AD. Within the locus ceruleus in the patients with AD, abnormalities were more severe at mid level than at caudal or rostral levels (p less than 0.01). Within the dorsal raphe nucleus, neuronal loss was most severe caudally (p less than 0.05). NFTs, but not neuronal loss, were demonstrated within the central superior nucleus. Neuronal and NFT counts did not correlate at individual levels; the relative severity of both pathological processes was consistent from level to level within nuclei but was less consistent between nuclei. Neuronal loss correlated inversely with age, particularly within the locus ceruleus. Duration of disease correlated inversely with counts of NFTs, particularly within the dorsal raphe nucleus, implying a correlation between NFT counts and rate of progression of disease as all but 3 patients had severe dementia. Significantly, patients with AD complicated by major depression had fewer neurons at the mid level of the locus ceruleus and at the rostral level of the central superior nucleus in comparison with nondepressed patients. There was a trend suggesting greater loss of neurons at all levels of the locus ceruleus and dorsal raphe nucleus in depressed individuals.

Adult↗
PubMed1987

Restrained drinking: risk factor for problems with alcohol?

A seven-item Drinking Restraint Scale (DRS) has been developed which indicates that a style of alcohol consumption, equivalent in a number of ways to the style of food consumption termed eating restraint, may exist. Several hypothesized relationships between DRS scores and other drinking-related measures were confirmed. A restrained drinking style was associated with: more extreme patterns of alcohol consumption; a higher proportion of drinking occasions that result in intoxication; more external styles of alcohol consumption control; and more alcohol-related negative consequences. The latter three relationships were found even when heavy drinkers were excluded from the analysis, which suggests that these relationships are not dependent on a heavy drinking pattern. These findings encourage continued investigation of drinking restraint as a risk factor for developing problems with alcohol.

Adolescent↗
PubMed1987

Enteric colonization with antibiotic resistant bacteria in nurses working in intensive care units.

To determine whether nurses who worked in an intensive care unit (ICU) might acquire enteric colonization with Gram-negative aerobic bacteria from their patients, rectal swabs were obtained from the patients and nurses in the ICU, from nurses working in a coronary care unit (CCU) and from young women with urinary tract infection who had not been exposed to the hospital environment. The healthy women differed from the patients in that their enteric flora contained greater numbers of lactose fermenting bacteria, they were less often colonized by resistant organisms and when resistant bacteria were present they were less abundant than in the patients. Nurses who had been treated with antimicrobial agents during the preceding six months were colonized more often with antibiotic resistant enteric bacteria. There was no evidence of transmission of antibiotic resistant Escherichia coli from patients to nurses largely because this species had been virtually eliminated from the patients by intensive use of antimicrobial agents. Instead, several multiresistant species of Klebsiella, Citrobacter and Pseudomonas were isolated from the patients and ICU nurses. It was difficult, however, to define clearly patient-nurse controls who had no exposure to the ICU patients. These observations and those of other investigators emphasize the need for examination of control populations and of therapeutic use of antibiotics when examining the issue of environmental acquisition of antibiotic resistant bacteria.

Adolescent↗
PubMed1987

Increased ventricle-to-brain ratio in late-onset schizophrenia.

For 29 patients with schizophrenia that began after age 44, the mean ventricle-to-brain ratio was significantly higher than for 23 age-matched normal subjects but significantly smaller than for 23 patients with Alzheimer's disease and hallucinations or delusions.

Adult↗
PubMed1986

Haloperidol versus thioridazine in the treatment of behavioral symptoms in senile dementia of the Alzheimer's type: preliminary findings.

To compare the efficacy and side effects of haloperidol and thioridazine in the management of behavioral symptoms of senile dementia of the Alzheimer's type, 16 patients were studied in an open crossover design study. Following 2-week drug washout, patients were alternately assigned to either haloperidol (1, 2, and 5 mg/day for 2 weeks) or thioridazine (25, 50, and 75 mg/day for 2 weeks). After completing the first neuroleptic, patients were washed out and then tried on the second neuroleptic. Six patients completed the crossover design, 1 received only haloperidol, and 9 received only thioridazine. Both drugs were effective in managing target behaviors, which included hostility, uncooperativeness, bothersomeness, emotional lability, and irritability. Complaints of fatigue and extrapyramidal side effects were greater with haloperidol than with thioridazine. Neither compound produced significant impairments in cognition as assessed by the Mini-Mental State Examination score or caused orthostatic hypertension.

Aged↗
PubMed1986

Anterior chamber pachymetry during accommodation in emmetropic and myopic eyes.

Optical pachymetry was performed on 15 nearly emmetropic and 15 myopic subjects with accommodation fully relaxed and with 3.00 and 6.00 dioptres of stimulus to accommodation. No significant difference was found between the change in anterior chamber depth per dioptre of stimulus between the two groups. This is in agreement with theoretical considerations, which suggest that a change in the length of the vitreous does not much affect the optical efficiency of the crystalline lens.

Accommodation, Ocular↗
PubMed1985

An inventory to measure staff knowledge of behavioral methods with inpatient children and adolescents.

A 35-item multiple choice inventory to assess inpatient staff's knowledge of behavioral methods with children and adolescents is described. The instrument appears to possess satisfactory content validity for basic behavioral principles and good internal consistency and reliability. It appears useful for research and staff inservice educational assessment in inpatient treatment settings where a measure of this type in needed. The inventory may also be useful in identifying newly employed staff who may benefit from behavioral training before assuming direct services roles on inpatient wards.

Adolescent↗
PubMed1985

Electrocardiographic estimate of peak systolic pressure gradient in children with aortic stenosis.

In children with congenital aortic stenosis a modified mapping system was created to explore the electrocardiographic potentials on the chest surface from the left sternal edge (direct anterior), left axillary line (direct lateral) and midchest (45 degrees anterior to the lateral lead) in the third through the seventh intercostal spaces. Potentials were normalized according to chest size based on elliptical and cylindrical models of the chest with the heart at the center. The unadjusted and adjusted potentials were correlated with the peak systolic gradients across the left ventricular outflow tract and equations to predict the gradients were derived by stepwise multiple regression analysis. The best equation was: Gradient = -15.0 +(3.845 X MCT 4) +(0.474 X CD X LSS 3) + (0.138 X CD X MCS 3) where MCT 4 = T wave amplitude in the lead in the fourth interspace in the midclavicular line CD = AP chest diameter in cm LSS 3 = S wave amplitude in the lead in the third interspace at the left sternal border MCS 3 = S wave amplitude in the lead in the third interspace in the midclavicular line (R = 0.84, SEE = 24.3) There are areas on the chest surface that are unexplored by standard electrocardiography. The electrocardiographic potentials from these areas, when normalized for chest size, yield better estimates of transaortic gradients than previous estimates from the routine electrocardiogram.

Adolescent↗
PubMed1985

Culture of the surfaces of urinary catheters to sample urethral flora and study the effect of antimicrobial therapy.

At the time indwelling urinary catheters were removed, the urethral flora was sampled by rolling the catheters onto culture plates. Cultures were obtained from 398 patients with sterile urine. Catheter surfaces were colonized less often in males than in females (16.8 and 67.0%, respectively) and yielded correspondingly fewer bacterial species per catheter. In both sexes, gram-positive species were isolated more frequently than gram-negative species (428 and 131 isolates, respectively). The bacteria most commonly isolated were Staphylococcus epidermidis and Streptococcus faecalis. Staphylococcus saprophyticus was not recovered despite the large proportion of young, sexually active women in the study population. Gram-negative bacteria, mainly Escherichia coli, gradually colonized the catheters over time but at all times were recovered in lower amounts the gram-positive organisms and less often in males than in females. Slime production by coagulase-negative staphylococci did not relate to the density of organisms recovered from the catheters or influence the presence of gram-negative bacteria. Despite frequent use of antibiotics in this population, the urethral flora remained highly susceptible to these drugs. Antibacterial activity was not detected on the catheters despite high concentrations in the urine. This suggests that systemic antibiotics have a very limited effect on resident urethral flora. Despite relatively small numbers in the urethra, gram-negative bacteria readily produce urinary tract infections in catheterized patients.

Adhesiveness↗
PubMed1985

A comparison of the frequency of major affective disorder in Huntington's disease and Alzheimer's disease.

Matched groups of patients suffering from Huntington's disease and Alzheimer's disease were compared for psychiatric morbidity prior to the onset of dementia. The Huntington's disease group showed twice the incidence of major affective disorder. This finding suggests a specific relationship between Huntington's disease and major affective disorder rather than the latter being a non-specific prodromal feature of dementia.

Affective Disorders, Psychotic↗
PubMed1985

Pokeweed mitogen-induced immunoglobulin secretion by peripheral blood lymphocytes from patients with primary intracranial tumors. Characterization of T helper and B cell function.

We have previously demonstrated that patients with primary malignant brain tumors have impaired in vivo and in vitro cell-mediated immunity. The purpose of the present research was to employ pokeweed mitogen (PWM)-induced secretion of immunoglobulin (Ig) by peripheral blood lymphocytes (PBL) to further investigate impaired lymphocyte function in these patients. The PWM response of PBL from normal individuals averaged 8384 plaque-forming cells (PFC) per 10(6) cells, whereas the response of PBL from patients averaged 1590 PFC/10(6). The decreased PWM response of PBL patients could not be improved by varying the number of PBL placed in culture or employing different concentrations of PWM. Co-culture experiments to detect the presence of suppressor cells in PBL and purified T cell preparations from patients demonstrated that enhanced suppressor cell activity was not evident. Next, experiments were performed to assess the T-helper cell activity present in purified T cell preparations obtained from patients. The results demonstrated that T cells from patients lacked the ability to provide adequate helper activity in the PWM response. Moreover, studies with monoclonal antibodies directed against T cell subsets revealed that PBL from patients have a reduced percentage of T-helper cells (40%) as compared with normal values (55%). In concert with T-helper cell anomalies, B cell function in these patients also is diminished. Thus, these observations indicate that a combined T-helper and B cell defect may contribute to the broad impairment of host immunocompetence observed in patients with primary gliomas.

Adolescent↗
PubMed1982

Preschool children's discrimination of age.

This study compared abilities of 4- and 5-yr.-olds to be accurate in connoting "who is older" without using size representation as a cue. An age discrimination task was administered to 30 4-yr.-olds and 30 5-yr.-olds. Analysis indicated that the 5-yr.-old children had better ability to discriminate age than the 4-yr.-old children but were not equal to adults. No significant sex differences were found in the children's ability to discriminate age.

Aging↗