PubMed Health⌕ Search

Biomedical subjects

J D Pierce

Publications and source records attributed to J D Pierce.

35 records · Page 2Linked to original sources
PubMed1992

Ejaculate disruption in two species of voles (Microtus): on the PEI matching law.

We permitted male prairie and montane voles (Microtus ochrogaster and M. montanus) five thrusts, without ejaculation, with a female at variable times after a 1st male ejaculated. In both prairie and montane voles, there were fewer sperm, in relation to control conditions, in the female's tract 1 hr after ejaculation if the female received thrusts immediately or 15 min after the ejaculate. There was no such effect after a 50-min delay. There was no significant decrease in litter production in prairie voles caused by thrusts delivered either immediately or after a 15-min delay. Sperm transport in these species is susceptible to disruption for a longer period than in deer mice or rats. The proposal that the postejaculatory interval protects a male from disrupting its own sperm transport (the PEI matching law) appears not to hold for these species.

Animals↗
PubMed1991

Cardiac transplantation with corticosteroid-free immunosuppression: long-term results.

To assess the long-term safety of an immunosuppressive regimen without corticosteroids, we retrospectively evaluated 42 long-term (greater than 1 year) survivors of orthotopic cardiac transplantation. We determined the incidence of (1) conversion of the immunosuppressive regimen from cyclosporine and azathioprine alone (group I) to cyclosporine, azathioprine, and prednisone (group II), (2) late acute graft rejection (defined as occurring at greater than 1 postoperative year), and (3) major postoperative complications related to corticosteroids. Of the 42 patients who were started on cyclosporine and azathioprine, 48% remained in group I, and 52% converted to group II. Forty-five percent of group II patients were able to taper and discontinue prednisone in 15.6 +/- 2.2 months. Among the patients on long-term corticosteroid-free immunosuppression, the incidence of late rejection was 2.1% per endomyocardial biopsy. The incidence of late infectious episodes was not significantly different between the two groups of patients, although diabetes mellitus and hypercholesterolemia were more prevalent in group II than in group I. These data suggest that cardiac transplant recipients who chronically remain on corticosteroid-free immunosuppression represent a select group of patients with an acceptably low risk of late graft rejection and associated reduction of potential risk factors of accelerated coronary artery disease.

Adult↗
PubMed1991

Odor identification deficit of the parkinsonism-dementia complex of Guam: equivalence to that of Alzheimer's and idiopathic Parkinson's disease.

Olfactory dysfunction is among the first signs of Alzheimer's disease (AD), idiopathic Parkinson's disease (PD), and the parkinsonism-dementia complex (PDC) of Guam. We have recently demonstrated that the odor identification and detection deficits of patients with PD are equivalent to those of patients with mild AD when subtle differences in cognitive function are statistically controlled for by analysis of covariance. In contrast, patients with progressive supranuclear palsy (PSP) and patients with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism evidence olfactory function much more similar to that of normal controls. In the present study, we administered the University of Pennsylvania Smell Identification Test and the Picture Identification Test to 24 patients with early signs of the PDC of Guam and statistically compared their test scores to those of 24 early-stage AD and 24 early-stage PD patients of similar age and gender from the United States mainland. Although the PDC group evidenced slightly more difficulty in identifying pictures than did the other 2 groups, the odor identification deficit associated with this disorder was of the same magnitude as that observed in AD and PD, suggesting that olfactory testing cannot be used to distinguish among these 3 diseases and that the olfactory dysfunction of these disorders may reflect a common neurologic substrate.

Adult↗
PubMed1991

Olfactory dysfunction in three neurodegenerative diseases.

Olfactory dysfunction is among the first signs of Alzheimer's disease (AD), idiopathic Parkinson's disease (PD), and the parkinsonism-dementia complex (PDC) of Guam. We have recently demonstrated that the odor identification and detection deficits of patients with PD are equivalent to those of patients with mild AD when subtle differences in cognitive function are statistically controlled for by analysis of covariance. In contrast, patients with progressive supranuclear palsy (PSP) and patients with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism evidence olfactory function much more similar to that of normal controls. In the present study, we administered the University of Pennsylvania Smell Identification Test and the Picture Identification Test to 24 patients with early signs of the PDC of Guam and statistically compared their test scores to those of 24 early-stage AD and 24 early-stage PD patients of similar age and gender from the United States mainland. Although the PDC group evidenced slightly more difficulty in identifying pictures than did the other 2 groups, the odor identification deficit associated with this disorder was of the same magnitude as that observed in AD and PD, suggesting that olfactory testing cannot be used to distinguish among these 3 diseases and that the olfactory dysfunction of these disorders may reflect a common neurologic substrate.

Adult↗
PubMed1991

Effects of two chest tube clearance protocols on drainage in patients after myocardial revascularization surgery.

The purpose of the study was to determine the effects of two methods of clot clearance on chest tube drainage in patients undergoing myocardial revascularization. Two hundred adult patients immediately after myocardial revascularization were randomly assigned to a specific chest tube manipulation group. The dependent variables were drainage, incidence of cardiac tamponade, incidence of surgical reentry, hemodynamic values, and number of manipulation episodes. Statistical analyses revealed no difference in any of the dependent variables when milking and stripping were used. Of the 200 patients, 78 did not require any manipulation of the chest tubes in the first 8 hours after surgery. One patient had signs of cardiac tamponade and six other patients required surgical reentry. Positioning of the connecting tube in a nondependent position assisted with the removal of drainage from the chest cavity. In conclusion, patients having myocardial revascularization did not need their chest tubes manipulated the first 8 hours after surgery. Visible drainage in the chest tube did not cause a lack of patency.

Blood Coagulation↗
PubMed1990

Patterns of sperm allocation across successive ejaculates in four species of voles (Microtus).

This study was designed to determine testes masses, total number of spermatozoa ejaculated per copulatory episode, and the pattern of sperm numbers in successive ejaculates in prairie voles (Microtus ochrogaster), montane voles (M. montanus), pine voles (M. pinetorum), and meadow voles (M. pennsylvanicus). Prairie voles displayed mean totals of 2.7 ejaculations and 30.5 X 10(6) spermatozoa before reaching a satiety criterion; montane voles 3.4 ejaculations and 19.0 X 10(6) spermatozoa, pine voles 2.4 ejaculations and 3.3 X 10(6) spermatozoa, and meadow voles 2.5 ejaculations and 25.5 X 10(6) spermatozoa. In all species the number of spermatozoa decreased in successive ejaculates. Significant species differences were noted for the total number of spermatozoa ejaculated and number of spermatozoa ejaculated in each of the first 3 ejaculates. Species differences also were noted for testes mass, with meadow voles having the largest testes and pine voles having the smallest. These data can be compared to similar data on laboratory rats and deer mice and related to recent theory regarding sperm numbers, testes sizes, and mating systems. In general, the species with large testes appear to ejaculate more spermatozoa. The significance of species differences in testes mass and total sperm numbers remains unclear, but may relate to the occurrence of multiple mating by females during a single receptive period.

Animals↗
PubMed1990

Acute esophageal bleeding and endoscopic injection sclerotherapy.

Endoscopic injection sclerotherapy in the critical care setting is a recently developed method for controlling bleeding from esophageal varices. Since this therapy is often employed as an emergency measure, nurses in ERs and ICUs should be familiar with the procedure. The enclosed outline can be modified to fit the needs of individual physicians, units, and institutions.

Endoscopy, Gastrointestinal↗
PubMed1989

A comparative study of rodent ultrasonic vocalizations during copulation.

The temporal patterning of ultrasonic vocalizations (USVs) during copulation was recorded for male-female pairs of Djungarian hamsters (Phodopus campbelli), prairie voles (Microtus ochrogaster), and montane voles (Microtus montanus). Each species appears to utilize a single major frequency band for USVs, centered around 31 kHz for the vole species and 71 kHz for hamsters. Djungarian hamsters exhibited low rates of USVs prior to introduction of the female and following ejaculation, but a high USV rate during periods of copulatory activity. Both vole species called at high rates during all stages of the copulatory sequence, although calling rates decreased following ejaculation. Anesthetization trials, where one pair member was awake and the other anesthesized, suggest that it is the male of each species that produces most USVs. The results were compared with six other muroid species for which data on the temporal patterning of USVs during copulation are available. These data extend our knowledge of the patterning of USVs during copulatory behavior and suggest the need for additional comparative investigations.

Animals↗
PubMed1988

Sexual activity and satiety over an extended observation period in prairie voles (Microtus ochrogaster).

This study was designed to delineate the course of sexual satiation in prairie voles (Microtus ochrogaster). Fourteen male-female pairs were allowed to copulate freely for 24 hr under continuous observation. Copulations occurred predominantly during the first few hours and decreased in frequency thereafter. The mean number of ejaculations per pair was 5.6 (range, 2-9). Two thirds of the ejaculations occurred during the first 3 hr, and over 90% took place within the first 7 hr after the first intromission. No ejaculations were observed during the last 8 hr. These results suggest that male capacity to deliver ejaculations to a female is limited and that direct observations reveal a more limited capacity than observations made with time-lapse videotape.

Animals↗
PubMed1988

Inhibitors of glycoprotein processing alter T-cell proliferative responses to antigen and to interleukin 2.

Most of the cell-surface molecules involved in T-cell immune responses are N-linked glycoproteins. We have investigated the effects of inhibitors of glycoprotein processing on specific T-cell functions, with the dual aims of examining the functional role of carbohydrate and of testing the usefulness of such compounds as immunomodulators. Treatment of a cloned murine helper T-cell line with these inhibitors differentially affects the proliferative response of the cell, depending upon the nature of the stimulus. Treatment with the plant alkaloid swainsonine, which inhibits the processing mannosidase II and causes the accumulation of glycoproteins bearing hybrid-type oligosaccharide structures, enhances the proliferative response of the T-cell clone to antigen and to the mitogen concanavalin A. Treatment with another plant alkaloid, castanospermine, which inhibits glucosidase I and causes the accumulation of glucose-containing high-mannose structures, has the opposite effect and inhibits the proliferative response of the T cell to antigen. Cell-surface oligosaccharide alteration does not affect antigen recognition, as judged by the lack of effect of either drug on interleukin 2 production following antigen stimulation. Cells treated with either alkaloid proliferate poorly to exogenous interleukin 2 and may have defective interleukin 2 receptor function. Swainsonine-treated cells apparently have compensatory alterations that can overcome the reduced responsiveness to interleukin 2. Antibody-binding studies indicate that normal quantities of many cell-surface molecules, including the T-cell receptor for antigen, are expressed by the treated cells.

Alkaloids↗
PubMed1985

Reliability of a sound-generating otoscope.

A sound-generating otoscope was compared with standard audiometric testing. Subjects of different ages and with different auditory pathologies were examined. The sound-generating otoscope was found to agree 92.4% of the time. Errors occurred more often with subjects having normal hearing. No single frequency delivered by the otoscope produced a significantly higher error rate than had been reported by other investigators. The otoscope can also be used to detect collapse of the external auditory meatus that might occur during regular audiometric testing.

Adolescent↗
PubMed1980

The prevention of hyaline membrane disease (HMD) in the preterm fetal lamb through the static inflation of the lungs: the conditioning of the fetal lungs.

Preterm fetal lambs of a gestational are highly susceptible to hyaline membrane disease were placed on apneic oxygenation while keeping the umbilical circulation intact and still connected to the mother ewe for the removal of metabolically produced CO2. After 4-6 hrs the total lung compliance and the chest x-ray films had markedly improved, allowing normal pulmonary ventilation with a mechanical ventilator. Fetuses older than 135 days gestation were later extubated and allowed to breathe room air unassisted. Fetuses 134 days gestation and younger were kept on mechanical ventilation. None of the animals so treated developed hyaline membrane disease. We believe pulmonary conditioning is an important tool in the prevention and the treatment of hyaline membrane disease. In this animal model we have shown that hyaline membrane disease is a preventable and curable disease.

Animals↗
PubMedDate not supplied

Reactive oxygen species in acute respiratory distress syndrome.

In the metabolism of almost all human cells, a sequential addition of electrons to oxygen leads to the formation of reactive oxygen species (ROS). ROS have been implicated in more than 100 diseases and may be the common denominator in the pathogenesis of the most important health problems facing the world today. The last decade has been characterized by a progressive increase in the understanding of oxidant chemistry and the role of ROS in pulmonary disease. The majority of deaths among critically ill patients are the result of sepsis and its sequelae, including acute respiratory distress syndrome (ARDS). Nurses must understand the processes involving ROS that are in play when they are caring for patients with ARDS. This article describes what is known about the formation of ROS, the pathophysiology of ARDS, and the role ROS play in the pathogenesis of ARDS.

Critical Care↗
PubMedDate not supplied

Evaluating diaphragm activity in trauma patients.

The diaphragm is the major respiratory muscle responsible for most of the inspiratory work of breathing. Bedside clinicians often overlook the need to assess the diaphragm or have never focused their attention on understanding the mechanisms behind this muscle. This article updates the trauma nurse on the anatomy and physiology of the diaphragm, reviews current methods for assessing diaphragm activity, and discusses research and diagnostic methods concerning the diaphragm. With heightened awareness of diaphragmatic function, clinicians may be able to improve the respiratory status of the trauma patient by preventing diaphragm fatigue or exhaustion.

Diaphragm↗
PubMedDate not supplied

Applying the new concepts of the Neuman Systems Model.

The latest version of the Neuman Systems Model contains new terminology--"spiritual variable" and "created environment"--and an emphasis on the concepts of primary prevention and wellness. A case study of a client who has tested positive for HIV explores the new terms and demonstrates the expanded concepts of primary prevention and wellness. Nurses can utilize this framework and the concept of wellness with terminally ill or healthy individuals. Nursing frameworks can be practical and useful to nurses and not just words in a theory book.

Adult↗
PubMedDate not supplied

Pressure support ventilation: reducing the work of breathing during weaning.

Pressure support ventilation decreases the work of breathing by providing the patient with positive airway pressure during the inspiratory phase. The use of this type of ventilatory support is likely to increase over the next few years for patients, especially during the weaning period. By understanding how pressure support ventilation works and what patient parameters need to be monitored, the critical care nurse can help patients decrease respiratory muscle fatigue during weaning and thus decrease the weaning time for these patients.

Critical Care↗