Biomedical subjects
Publications and source records attributed to G Peterson.
Multiple idiopathic root resorption is a specific entity that must be delineated from all other resorptive processes. We present a case report and discuss the diagnostic possibilities that must be considered before arrival at this diagnosis.
Suppression of anisometropic blur induced by monovision contact lenses was examined in 18 presbyopic subjects. Suppression ability was quantified by reducing the contrast of a bright test target, viewed by subjects wearing a monovision correction, until the blurred image was suppressed. Subjective success with monovision was evaluated using a patient survey and no correlation to blur suppression ability was found. Objective success was evaluated in terms of performance at three near work tasks, each requiring a different level of stereoscopic localization. A significant correlation was found between card filing performance (requiring a moderate level of stereopsis) and blur suppression ability. Correcting either the dominant or non-dominant eye for near in the monovision correction did not significantly affect blur suppression ability. There was no evidence for adaptation to monovision in terms of increasing blur suppression ability over time.
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The Pawtucket Heart Health Program is one of the community studies examining whether population-based efforts to lower cardiovascular risk factors will reduce cardiovascular morbidity and mortality. The Pawtucket Heart Health Program intervention is based on a blend of social learning theory, community organization models, community psychology tenets, and diffusion research. This model allows for multifaceted programs that target individuals, groups, organizations, and the entire community to alter their cardiovascular risk through managing blood pressure, lowering blood cholesterol, quitting smoking, increasing fitness, and maintaining desirable weight levels. A dominant feature of the intervention is the emphasis that it places on volunteers for program delivery. The role of volunteers in providing direct services to help citizens lower their blood pressure and lose weight is highlighted to demonstrate the feasibility and effectiveness of these services. In addition, church-based programming which utilizes volunteers to manage and direct programs is also presented as an example of community-based health promotion efforts that promote collective efficacy.
The Pawtucket (Rhode Island) Heart Health Program is designed to effect a community-wide change in heart disease morbidity and mortality by reducing smoking prevalence and other behavioral risks for this disease. The initial emphasis of the Pawtucket Heart Health Program was on the development of risk factor programs within specific churches, work sites, and other organizations in the community. At the end of 9 months of programming, however, only one organization had elected to begin a stop-smoking program. Given the community smoking prevalence of 43.4%, it was decided that larger-scale interventions would be required if a significant public health impact was to be realized. Therefore, a community-wide campaign was mounted to recruit as many participants as possible into the "Up in Smoke" cessation program. A lottery was attached to this program, with the contingency based on program attendance rather than cessation per se. One hundred three participants, including residents of neighboring communities, enrolled in three Up in Smoke lottery groups. At a 3-month follow-up, only 11 (7%) of smokers from the Up in Smoke lottery reported that they were not smoking (10% of those actually contacted). For a variety of reasons, the "Quit and Win" approach was later adopted by the Pawtucket Heart Health Program as the primary smoking intervention. One month after the end of the contest, 20% of those contacted reported not smoking. The percentage of quitters for the Up in Smoke program increased while the Quit and Win rate decreased over longer periods of follow-up. These and other data were compared with those of participants of a screening program conducted concurrently. Lotteries in general and face-to-face recruitment in large crowds were shown to be effective recruiting methods for large-scale smoking cessation programs.
Antibody to Campylobacter pyloridis was measured by ELISA in the sera of 160 patients from whom gastric biopsy specimens were also obtained. The antigen was an acid-glycine extract of C. pyloridis, and titers ranged from 80 to 22,000 ELISA units (EU). Of 117 patients in whom C. pyloridis was detected microbiologically or histologically, 87 (74%) had a titer greater than or equal to 300 EU, and only one had a titer less than 150 EU. Of 43 patients in whom C. pyloridis was not detected, only two (5%) had a titer greater than 300 EU. Thus, for a titer of 300 EU the ELISA test had a specificity of 97% and a sensitivity of 81%. At 150 EU the specificity was 78%, and the sensitivity was 99%. Histological diagnosis of active chronic gastritis was associated with a high median ELISA titer (485 E), chronic gastritis with a much lower titer (150 EU), and normal histology with a titer of 110 EU. Discriminating use of this serological test could be of assistance to detect C. pyloridis in the gastric mucosa.
We have constructed two recombinant plasmid vectors for direct expression and amplification of cDNA in mammalian cells. Each vector carries two dominant selectable markers (the bacterial neo gene and the mouse DHFR gene), a promoter sequence (viral LTR in pAV009/A+, and sheep metallothionein promoter in pMT010/A+), a polyadenylation signal sequence, and a Bam HI site to allow insertion of cDNA. We have used these vectors to prepare recombinant clones for the expression of rat phenylalanine hydroxylase (PH) in LTK- cells. Selection of transformants with neomycin followed by selection of the transformants in methotrexate led to a 30- to 60-fold amplification of the DHFR marker and co-amplification of the PH cDNA, with a corresponding increase in the level of PH mRNA and enzyme polypeptide. The expressed enzyme has a subunit molecular weight of 50,000 which corresponds to the W- allele of rat liver PH. PH activity was detected in the transfected cells by enzymatic measurement of the conversion of [14C]phenylalanine to [14C]tyrosine, and by growth of these cells in a tyrosine-free culture medium. Expression of rat PH in cell culture should facilitate the analysis of the biochemical properties of this enzyme.
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Many self-reported measures of health status, attitudes, and knowledge used by clinicians and researchers suffer from a variety of shortcomings, including limited empirical justification, excessive complexity, assessments of nonmodifiable historic or hereditary factors, and limited utility for public health program planning. The Health Attitudes and Behavior Scale is an instrument designed to overcome many of these shortcomings and direct public health professionals toward more efficacious interventions. One hundred sixty-four subjects responded to true-false and Likert scale items related to health beliefs, attitudes, and behavioral practices. A principal component analysis of the Likert items yielded six components, tentatively labeled (a) Lack of Social Support, (b) Hurdles to Health, (c) Health Attitudes/Weight Concerns, (d) Positive Environment, (e) Disease Concerns, and (f) Time and Work Pressure. Analyses of these scales using coefficient alpha indicated adequate internal consistency for each of them. These scales were then related to demographic variables of age, educational level, sex, and marital status. Next, these scales were correlated with individual true-false items reflecting self-reported behavioral practices or health histories. A component analysis of the true-false items yielded four principal components labeled (a) Organizational Health Concerns, (b) Smoking and Exercise Concerns, (c) Coronary and Weight Concerns, and (d) Blood Pressure and Risk Factor Programs. Finally, a cluster analysis yielded six typical profiles reflecting different levels of the original six components. Of interest is the fact that the Lack of Social Support and Time and Work Pressure scales had a very limited integration into the overall patterns. The assumption that organizational and environmental factors can have an important impact on health was supported. The need for further research in this area is also discussed.
We have deduced the amino acid sequence of the N-terminal leader peptide of the mitochondrial enzyme ornithine transcarbamylase from a cDNA clone obtained from a rat liver cDNA library. The sequence is remarkable in being highly basic, having 4 arginine, 3 lysine and 1 histidine with no acidic residues in a total of 32 residues. The leader sequence has no extensive hydrophobic stretches, has 72% homology with the leader peptide of human ornithine transcarbamylase [1], and in terms of its basic character resembles the N-terminal extensions on a number of fungal mitochondrial [2-5] and pea chloroplast [6] proteins. Thus the basic nature of these leader peptides may constitute the signal for mitochondrial import.
Between January 1979 and December 1982, 84 patients between the ages of 1 and 39 years presented to the emergency department in a state of cardiac arrest. There were 58 male patients (69%) and 26 female patients (31%) in the group. Presenting rhythms were ventricular fibrillation (37%), asystole (37%), idioventricular rhythm (14%), heart block (4%), bradycardia (4%), ventricular tachycardia (3%), and electromechanical dissociation (3%). Thirty-two percent had bystander CPR. Of 21 patients initially resuscitated (25%), only four (5%) survived to discharge from the hospital. All survivors were neurologically intact. Seventy-five of the 80 patients who died (90%) underwent autopsy. Cause of death in the five remaining patients was inferred from clinical history. Etiologies of the cardiac arrests were the following: toxic exposure or ingestion (26%), atherosclerotic heart disease (23%), undetermined (11%), pulmonary embolism (6%), hemorrhage (6%), epilepsy (2%), cardiomyopathy (7%), myocarditis (2%), pneumonia (4%), and one case each of airway obstruction, asthma, peptic disease, and septic shock. Diverse etiologies should lead to a diagnostic search for reversible conditions in young patients. The prognosis for hospital discharge is poorer in the young population than is reported in our overall cardiac arrest population; however, numbers of neurologically intact survivors are similar in the young and the overall cardiac arrest population.
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Calmodulin is a ubiquitous intracellular calcium binding protein which has been shown to be associated with cell cycling. Previous studies using animal tumor models have suggested a positive correlation between tumor calmodulin content and rate of tumor growth. We studied the role of calmodulin in renal cell carcinoma (RCC) cell lines and compared this with short term normal fetal kidney cell lines. The effects of calmodulin inhibition was determined using the calmodulin inhibitor W13 (Naphthalene-sulfonamide) and its less active partner W12. Cell size, calmodulin content and inhibition studies using W13 did not reveal any simple correlations for the RCC cell lines, although the RCC lines did have a higher content than the fetal kidney cell lines. Calmodulin content determination of RCC and normal adult kidney tissue failed to show any difference. We conclude that, contrary to previous reports using animal models, there is no simple relationship between tumor growth rates and calmodulin content for human RCC.
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An anterior mediastinal haematoma and left haemothorax developed in a hypertensive diabetic patient on oral anticoagulant therapy. This occurred in spite of well-controlled anticoagulation and the absence of other evidence of systemic bleeding. Angiography and daily chest X-ray follow-up were not only sufficient to confirm the diagnosis, but also avoided hazardous interventional procedures.
Spinal cord compression is a rare but serious complication of malignant diseases in children. Epidural cord compression was noted in 81 patients within the past 17 years at this center. The complication developed at different times during the course of the primary disease. For 29 of our patients, cord dysfunction was one of the initial signs of cancer--Ewing sarcoma, neuroblastoma, Hodgkin disease, and malignant lymphoma. By contrast, for most of the patients with osteosarcoma and rhabdomyosarcoma, it appeared later in their clinical course. The treatment outcome of patients who were paraplegia with complete loss of sensory function for greater than or equal to 48 hours was poor. Only four of 22 in this group became ambulatory. Ten patients with osteosarcoma did not undergo laminectomies because they all had multiple metastases and terminal disease. Paraplegia developed in all ten. There was no difference in ambulatory rates among other patients, with or without laminectomies.
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