Biomedical subjects
D L Patterson
Publications and source records attributed to D L Patterson.
Management in unstable angina.
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Fatal rhabdomyolysis associated with hyperosmolar diabetic decompensation.
A patient is described who developed fatal acute rhabdomyolysis in association with hyperosmolar diabetic decompensation. The delay in making the diagnosis of acute rhabdomyolysis may have contributed to the outcome as the use of dantrolene may be of benefit in such patients.
Effects of acute and chronic dimethylamine exposure on the nasal mucociliary apparatus of F-344 rats.
Dimethylamine (DMA) is a highly water soluble gas with many industrial applications. Male F-344 rats were exposed to 175 ppm DMA 6 hr per day for 1, 2, 4, or 9 days or 2 years. Gross changes in nasal structure were recorded, effects of DMA on the mucociliary apparatus were assessed using video analysis, and tissues were evaluated for histopathology. In vitro nasal mucociliary flow patterns, mucus flow rates, and ciliary activity were studied and recorded for video motion analysis. There were distinct and generally consistent differences in the shape of the naso-, maxillo-, and ethmoid turbinates between young and old animals. Acute and chronic DMA exposures resulted in erosion of the anterior margins of the naso- and maxilloturbinates and fenestration of the adjacent septum. Ciliastasis and mucostasis were observed only on the anteromedial aspect of the maxilloturbinate. In the chronically exposed rats, mucociliary activity was present in areas adjacent to erosions of the turbinates and septum. Abnormal mucus flow patterns, including altered or reversed direction of flow and "whirlpool-like" formation, were observed in all treated rats, but were more severe following chronic exposure. There was a good correlation between the distribution of responses as assessed by histopathology and abnormal mucociliary function at all time points. In conclusion, the mucociliary apparatus continues to function in the nasal passages of rats having localized destruction of nasal epithelium, induced by DMA exposure, and this clearance system responds to alterations of nasal structure by modification of mucus flow patterns.
Shoshin beriberi: an underdiagnosed condition?
Shoshin beriberi, a fulminant form of heart failure due to thiamine deficiency has a different presentation to the classical form of beriberi heart failure. It is characterized by a cold periphery, low blood pressure, renal shutdown and a severe metabolic acidosis. The true incidence is unknown. Two patients were seen within a few months in a general hospital and in both dietary deficiency of thiamine was a major factor.
Distribution, progression, and recovery of acute formaldehyde-induced inhibition of nasal mucociliary function in F-344 rats.
A previous report of inhalation exposure of F-344 rats to formaldehyde gas, using a whole-body exposure system, described the induction of regional inhibition of nasal mucociliary function, with a clear concentration-response relationship. A head-only exposure system was subsequently developed in order to facilitate the present study of reversibility of acute effects of formaldehyde on the nasal mucociliary apparatus. This study also included an examination of more extensive areas of the nose than those reported in the previous work. Male F-344 rats were exposed to 2 or 15 ppm formaldehyde gas for 10, 20, 45, or 90 min or 6 hr with recovery groups examined 1 hr after the end of the 90-min and 6-hr exposures. No effects were observed in rats exposed to 2 ppm formaldehyde. In rats exposed to 15 ppm, the extent of formaldehyde-induced inhibition of mucociliary function detected in specific regions of the nose was time dependent, with increasing areas of mucostasis and ciliastasis being induced during a 6-hr exposure period. A 1-hr room-air exposure, following exposure to 15 ppm formaldehyde, resulted in marked recovery of mucociliary function, indicating the value of a head-only exposure system for rapid examination of mucociliary function following exposure. Recovery of mucociliary function occurred especially in the more posterior areas of affected regions of the nose. However, in areas of recovery mucus flow rate was reduced compared to unexposed control rates, indicating incomplete recovery of function in these areas. Regions of formaldehyde-induced inhibition of mucociliary function correlated well with the previously reported distribution of formaldehyde-induced nasal squamous cell carcinomas, with the exception of effects on the medial aspect of the maxilloturbinate. These findings were considered to provide further support for the proposal that both regional exposure and local tissue susceptibility may be responsible for the distribution of formaldehyde-induced nasal squamous cell carcinomas. It was also postulated, on the basis of mucus flow patterns derived from control animals in this study, that flow relationships between nasal mucus and inspired air form a countercurrent system which may optimize clearance of inhaled air contaminants.
Responses of the nasal mucociliary apparatus of F-344 rats to formaldehyde gas.
The nasal mucociliary apparatus is an important component of the airway defenses. Studies were undertaken to determine the nature and distribution of acute effects of inhaled formaldehyde on the nasal mucociliary apparatus of male F-344 rats using whole body exposures. Formaldehyde exposures ranged from a single 6-hr period up to multiple 6-hr exposures daily for 3 weeks, with exposure concentrations of 15, 6, 2, 0.5, and 0 ppm. Within 1 hr of the last exposure, the rats were killed and the nasal passages examined for effects on nasal mucociliary function. Exposure to 15 ppm formaldehyde induced inhibition of mucociliary function in specific regions of the nose, and mucostasis was generally more extensive than ciliastasis. These effects, which were initially confined to the anterior regions of the nose, became progressively more extensive for up to 2 weeks of exposure with only very slight progression during the third week. Inhibition of mucociliary function was much less severe with 6 ppm, minimal at 2 ppm, and not detected in rats following exposure to 0.5 ppm. The distribution of epithelial lesions, identified by histopathology, correlated well with the distribution of defective mucociliary function, but mucociliary function was a more sensitive indicator of toxicity. Localized defects in mucociliary function represent a potentially important consequence of exposure to formaldehyde.
[A procedure for study of the effects of irritant gases on the nasal mucociliary apparatus of rats].
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Frog palate mucociliary apparatus: structure, function, and response to formaldehyde gas.
The upper respiratory tract mucociliary apparatus represents one of the first defenses against inhaled noxious materials. The frog palate has been widely used as a model to investigate the mode of action of this apparatus and to study its response to irritant gases. Video analysis was used here for the determination of mucus flow rate and flow patterns, ciliary beat frequency, and the nature of ciliary activity in the in vitro frog palate preparation. The results of studies of time-lapse video recordings were used in conjunction with light microscopic and ultrastructural morphologic investigations to determine functional interactions between cilia, the epiphase, and the periciliary fluid. It was concluded that the cilia enter the epiphase during the effector stroke, that waves may be produced on the under surface of this layer, and that the periciliary fluid is less viscous than, and moves in the same direction as, the epiphase. The response of the frog palate mucociliary apparatus to formaldehyde gas was also studied using an in vitro exposure system. There were distinct concentration-related responses to formaldehyde with initial stimulation, and at higher concentrations, subsequent inhibition of mucociliary function. Stimulation of mucus flow rate was due to increased ciliary activity, while inhibition of flow, which preceded ciliastasis, was attributed to direct effect of formaldehyde on the superficial mucus layer. Ciliastasis on the other hand was considered to provide evidence that the formaldehyde had penetrated the mucus layer and induced direct toxic effects on the underlying epithelial cells.
The nasal mucociliary apparatus. Correlation of structure and function in the rat.
Rats are used extensively in inhalation toxicologic studies, but little information is available on the rat nasal mucociliary apparatus. The function of the rat nasal mucociliary apparatus was studied in vitro by video analysis, and its structure was examined by light and electron microscopy. Video analysis permitted determination of mucus flow rate and ciliary beat frequency without disrupting mucociliary function. In different regions of the nose, there was a characteristic mucus flow rate, flow pattern, and ciliary beat frequency, with minimal interanimal variation. Analysis of data pairs revealed no evidence of a correlation between mucus flow rate and ciliary beat frequency, ciliary length, density of the ciliated cell population, or the products of these factors. Mucus was seen to flow over certain nonciliated areas, and it is proposed that the mucus is pulled over these areas. Mucus flow characteristics indicated that the hypophase was less viscous than, and moved in the same direction as, the epiphase. The nasal mucus was present as a continuous layer over the respiratory epithelium, and had an osmiophilic surface film, which was found to be made up of 2 separate membranous components. On the basis of these studies, it was concluded that the rat nasal mucociliary apparatus represents a useful and readily accessible model for in vitro studies of nasal mucociliary function.
Use of the UCHT1 monoclonal antibody to explore mouse mutants and development.
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Assessment of pediatric pain: an empirical perspective.
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Pulmonary hypertension associated with hepatic cirrhosis and primary acrocyanosis.
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Pancreatitis with salmonella gastroenteritis.
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Metabolism of rhesus monkey spermatozoa.
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Prevention of coagulum formation with recovery of motile spermatozoa from rhesus monkey semen.
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Psychosocial issues in primary care of lesbian, gay, bisexual, and transgender youth.
Lesbian, gay, bisexual, and transgender youth are at risk for a multitude of physical, emotional, and social health problems. During the past decade it has been well documented that these youth have higher-than-average rates of depression, suicide attempts, substance abuse, sexually transmitted diseases, school failure, family rejection, and homelessness. The focus of this article is to outline skills and strategies that can assist the health practitioner in creating an optimal health care experience for sexual minority youth. Models of individual and family adaptation, a clinical path, and a referral list are presented. Current health care delivery sites are examined, and recommendations are given for improvement of both practitioner skills and health care programs targeting these youth.
PNP roles and interventions with children with special needs and their families.
Pediatric nurse practitioners (PNPs) can create excellent professional roles caring for children with special health care needs (CSHCN) and their families. Children with chronic conditions represent an estimated 31% of the US population younger than 18 years (approximately 20 million children in 1988). Five percent of all children who have multiple special needs account for approximately 40% of all pediatric health care expenditures. Skill building is needed for PNPs who have traditionally focused on wellness and common acute illnesses in primary care settings. Role theory and research can guide PNPs in creating roles and interventions to improve the health, safety, and developmental outcomes for CSHCN and their families. Two roles are described, with examples of specific nursing interventions. Assisting child care centers to serve children and families with special needs is an ideal role for PNPs who have knowledge of health and regulatory issues. Another important PNP role is working with adolescents with special health care needs as they transition from pediatric to adult care. Many resources (such as those from the Maternal and Child Health Bureau) are available to assist PNPs to create new roles and interventions for CSHCN and their families.