PubMed Health⌕ Search

Biomedical subjects

C Steele

Publications and source records attributed to C Steele.

At least 55 records · Page 3Linked to original sources
PubMed1996

Accuracy of clinical diagnosis of Alzheimer disease and clinical features of patients with non-Alzheimer disease neuropathology.

Neuropathological examination confirmed the clinical diagnosis of possible or probable Alzheimer disease (AD) in 90 of the first 100 patients who came to autopsy at the Johns Hopkins Alzheimer's Disease Research Center. In 10 cases, postmortem brain examination did not confirm AD but revealed variable patterns of neuronal loss in neocortex and limbic structures without amyloid deposits. The most common pattern of degeneration was relatively isolated hippocampal sclerosis (HS). Despite the finding that the 10 patients with non-AD neuropathology were ill for less time and were less cognitively impaired at study entry than those patients with definite AD, they had shorter survival times and showed equal behavioral disturbance at study entry (on a standardized measure). The clinical case reports included here suggest early and progressive prominent behavioral disturbance and other indexes of rapid illness progression in three of the four HS patients and two other non-AD patients. We conclude that the criteria of the National Institute of Neurological Disorders and Stroke/Alzheimer Disease and Related Disorders Association for possible or probable AD are highly accurate and that misdiagnosis is most likely to occur early in the course of illness and in patients with prominent behavioral disturbance or other atypical features.

Age of Onset↗
PubMed1996

Hospital-based behavior modification program for adolescents: evaluation and predictors of outcome.

This study is an evaluation of a residential short-term program (10-12 weeks) which utilizes a behavior modification program (BMP) in an inpatient unit for adolescents with mostly conduct problems. Evaluation included predictors of outcome such as age, gender, diagnosis, length of stay, father's presence, other treatments received, and presence of learning problems. The design used was a retrospective analysis of performance of patients on BMP measured by mean point earned in the first four weeks (pre-test) and the last 4 weeks of admission (post-test). Subjects were 60 adolescents aged 12-18 enrolled for at least eight weeks in the BMP. Findings showed that the BMP was generally beneficial especially for females and nonconduct-disordered patients. Factors such as father's presence, and absence of learning problems were associated with better outcome. Age and length of stay were not correlated with significant improvement. It was found that the BMP was effective in reducing frequency of undesirable behaviors for the majority of adolescents with conduct problems. However, males with a diagnosis of conduct disorder might require a longer stay for the program to be effective.

Adolescent↗
PubMed1995

Mania in Alzheimer's disease.

A chart review of 134 patients with Alzheimer's disease (AD) showed a 2.2% prevalence of mania, lower than previously cited. Of 3 patients with mania, 2 had a history of mania before the onset of AD. Prevalence rates and the role of Alzheimer's disease in the development of mania are discussed.

Aged↗
PubMed1994

Effect of different antibiotics on efficiency of transformation of bacteria by electroporation.

We noted large differences in the transformation efficiency of Escherichia coli when different methods were used for transformation. To analyze these observations, the ampicillin and tetracycline resistance plasmid, pBR322, was transformed into HB101 and DH5 alpha E. coli using calcium chloride or electroporation, and the clones containing the plasmids were selected under various conditions. Electroporation yielded around 5 x 10(7) transformants per microgram of plasmid DNA when ampicillin was used for selection, but only 5 x 10(5) transformants per microgram when tetracycline was used. A calcium-chloride method of transformation showed no differences between the two antibiotics. The loss of efficiency of electroporation in the presence of tetracycline was also seen with three tetracycline-related antibiotics and could be blocked by chelating agents. It was also overcome by a 3-h preincubation of the bacteria before exposure to antibiotic. D-Cycloserine showed a selective effect on electroporated bacteria, but Polymyxin-B, chloramphenicol or phosphonomycin did not. The mechanism of inhibition by tetracycline-related antibiotics is not known, but the results show that the recovery of electroporated bacteria may be significantly decreased if these antibiotics are used.

Ampicillin↗
PubMed1993

Effects of human papillomavirus type 18-specific antisense oligonucleotides on the transformed phenotype of human carcinoma cell lines.

DNA of human papillomavirus type 18 is present in several human cancer cell lines that were derived from oral or cervical tumors, and it is known that several features of the transformed phenotype can be inhibited by expression of antisense RNA to human papillomavirus (HPV). The present study was performed to find out whether antisense oligonucleotides were also inhibitory. Synthetic oligonucleotides were made that were complementary to regions of the start codons of the E6 and E7 genes of HPV-18. These were added to cultures of the oral cancer cell line 1483 and the cervical cancer cell line C4-1, each of which contain DNA of HPV-18. As controls we used the oral cancer cell line 183 and the monkey kidney cell line Vero, which do not contain HPV. Anti-E6 and anti-E7 oligonucleotides, in concentrations between 1 and 5 microM, significantly inhibited the growth of the 1483 and C4-1 cells, but not the 183 or Vero cell lines. Treatment of the 1483 cells with a combination of 2.5 microM of each of the antisense oligonucleotides was a more effective inhibitor than 5 microM of either one used alone. Antisense oligonucleotides had no effect on the ability of 1483 cells to form foci in soft agar, nor on their plating efficiency or serum requirements. Microscopic examination of 1483 cells showed that the antisense E7 oligonucleotide produced cell-rounding, detachment from the surface of the culture flask, and cell death, while the antisense E6 oligonucleotide had none of these effects. Random-sequence oligonucleotides had no effects of any type on any cells that were growing in culture. However, if random-sequence oligonucleotides were added to cells at the time they were passed to a new culture vessel, they produced severe nonspecific toxic effects. These results show that the use of synthetic oligonucleotides is an effective way of producing antisense-mediated changes in the behavior of human cancer cells that contain DNA of HPV-18.

Base Sequence↗
PubMed1993

A static dynamometer measuring multidirectional torques exerted simultaneously at the hip and knee.

The function of a static dynamometer measuring torques exerted simultaneously in the different anatomical planes of the hip (flexion-extension, abduction-adduction and internal-external rotation) and knee (flexion-extension) is described. Muscular torques were calculated in real time using a desktop computer from measurements of orthogonal forces applied at two locations and the lever arm values measured in each subject. The reliability of the force transducers was explored by examining their output, using calibrated weights, on three different days. The results were identical over this period of time, indicating that the transducers are highly reliable. A mechanical simulator of a lower limb was constructed to generate specific or combined torques of known values at the hip and knee. The torques measured by the dynamometer were found to be highly concordant with the known torques applied by the simulator, indicating that the torque measurements were valid. The usefulness of the dynamometer is demonstrated by evaluating the activity of the rectus femoris and biceps femoris muscles during static efforts exerted in various directions at the hip. In addition, the mechanical action of biarticular muscles at the hip was evaluated by quantification of hip torques during efforts exerted at the knee. From these results, it has been concluded that the present biarticular and multidirectional dynamometer is a valid, reliable and precise instrument that may prove to be useful in evaluating the muscular function of the lower limb.

Biophysics↗
PubMed1992

Effect on cancer cells of plasmids that express antisense RNA of human papillomavirus type 18.

Some human squamous cell carcinomas contain DNA of human papillomaviruses (HPV) and express RNA from the E6 and E7 genes. We have examined the effect of plasmids that express antisense RNA of these genes on the growth of the human cancer cell lines HeLa, C4-1, and 1483, which contain HPV type 18 DNA. As controls, the human cancer cell line 183 and the Vero line of monkey kidney cells were used, which do not contain HPV. Plasmids were introduced into the cells by electroporation; cells that contained HPV type 18 accepted the antisense-expressing plasmids at a lower frequency than the cells that lacked HPV. Cell lines were developed from HeLa cells that contained sense- or antisense-expressing plasmids, and lines that contained antisense-expressing plasmids showed slower growth, reduced ability to form colonies in soft agar, and increased serum requirements. The use of antisense HPV RNA might be a suitable approach to gene therapy of HPV-expressing human cancers.

Animals↗
PubMed1991

Physostigmine in Alzheimer's disease: effects on cognitive functioning, cerebral glucose metabolism analyzed by positron emission tomography and cerebral blood flow analyzed by single photon emission tomography.

The effect of acute, intravenous administration of physostigmine on measures of brain activity and cognitive functioning were investigated in 14 patients with Alzheimer's disease. Regional cerebral glucose metabolism was assessed using (18F)-fluoro-2-deoxy-D-glucose and positron emission tomography, and cerebral blood flow was assessed using 123I-iodoamphetamine single photon emission tomography. Although physostigmine enhanced cerebral blood flow in most patients, only one patient showed significant clinical improvement. This patient, however, also showed a very pronounced improvement in cerebral glucose metabolism. It is concluded that these preliminary findings hold considerable promise for our appreciation of the pathophysiology of dementing illness as well as our understanding of centrally acting compounds of interest in Alzheimer's disease.

Aged↗
PubMed1991

Psychosis and physical aggression in probable Alzheimer's disease.

OBJECTIVE: The purpose of this study was to determine the frequency and type of psychotic symptoms in patients with probable Alzheimer's disease and to test whether there is a relationship between specific psychotic symptoms and episodes of physical aggression. METHOD: From 209 patients with possible or probable Alzheimer's disease who had been assessed in a research clinic every 6 months for up to 4.5 years, 181 subjects with probable Alzheimer's disease were selected for study. On the basis of the summary note for each visit in the patients' charts, the presence of delusions, hallucinations, misidentifications, and episodes of physical aggression was determined. Data regarding psychotic symptoms and aggression were available for 170 and 169 subjects, respectively. RESULTS: Delusions had been reported for 74 (43.5%) of the patients and were the most frequent psychotic symptom; persecutory delusions were the most common type. Physical aggression had been noted for 50 (29.6%) of the patients. Delusions and misidentifications frequently preceded and were significantly associated with episodes of physical aggression. The presence of delusions was a significant predictor of physical aggression but accounted for only 3.5% of the variance. CONCLUSIONS: This study suggests that delusions are a risk factor for physical aggression in patients with probable Alzheimer's disease who have moderate to severe cognitive impairment. As delusions accounted for only a small percentage of the variance, further research is needed to identify other variables that may be significant predictors of physical aggression in this population.

Aged↗
PubMed1991

Viruses and oral cancer.

Oral cancer is a disease with a complex etiology. There is evidence for important roles of smoking, drinking, and genetic susceptibility, as well as strong indications that DNA viruses could be involved. The herpes simplex virus type 1 has been associated with oral cancer by serological studies, and animal models and in vitro systems have demonstrated that it is capable of inducing oral cancer. Papillomaviruses are found in many oral cancers and are also capable of transforming cells to a malignant phenotype. However, both virus groups depend on co-factors for their carcinogenic effects. Future research on viruses and oral cancer is expected to clarify the role of these viruses, and this will lead to improvements in diagnosis and treatment of the disease.

Animals↗
PubMed1990

Effects of intravenous xylazine hydrochloride on blood glucose, plasma insulin and rectal temperature in neonatal foals.

The effects of intravenous xylazine hydrochloride on blood glucose, plasma insulin and rectal temperature were investigated in six foals at 10 and 28 days of age. These variables were also measured in three foals at 19 days of age when saline alone was injected. Rectal temperature fell significantly after 30 mins in both groups of xylazine treated foals and was still depressed after 120 mins. Hypothermia did not occur in the saline control group. There was no significant change in blood glucose or plasma insulin concentrations during the 120 mins following either xylazine or saline administration and no significant differences between the three groups of foals. When foals were allowed to suckle after being away from their dams for 2 h, there was a significant (P less than 0.01) rise in plasma insulin levels in all the groups. Blood glucose showed a concomitant rise but this was only significant in the saline group. Unlike adults, intravenous xylazine (1.1 mg/kg) does not produce hypoinsulinaemia and hyperglycaemia in foals. This study suggests that the inhibition of insulin release from pancreatic beta-cells by xylazine, which in adults is alpha 2-adrenoceptor mediated, is immature or absent in foals under one month of age.

Animals↗
PubMed1990

Psychiatric symptoms and nursing home placement of patients with Alzheimer's disease.

Two hundred ten community-dwelling patients with Alzheimer's disease were examined prospectively by psychiatrists as part of a longitudinal study. Twenty-five of these patients who were institutionalized during the next 3 years were then matched to 25 patients who were not institutionalized, and the groups were compared. The patients who had been institutionalized had higher scores on standardized psychiatric rating scales but not on formal neuropsychological tests of cognition. These results suggest that potentially treatable (noncognitive) behavioral and psychiatric symptoms are risk factors for institutionalization, and that treating these symptoms might delay or prevent institutionalization of some patients.

Aged↗
PubMed1990

Applying neopiagetian theory to the moral reasoning process.

This study examined moral reasoning process and patterns of skills underlying a moral dilemma through use of K. W. Fischer's theory for cognitive skill acquisition. Kohlberg's Heinz dilemma issues of life and law were hypothesized as scalable within task-domains pertaining to Familial Relationships, Sickness/Death, Laws/Rules, and Fairness. 80 4- to 12-yr.-olds were interviewed regarding these issues. Guttman scale analyses examined scalability of their responses to items in each task and skill domain. Guttman coefficients validated task-domain scales of Laws/Rules and Fairness. Other scale coefficients approached validity. A revised scale is proposed for study.

Attitude to Death↗