Surface Electrical Activity from Schistosoma mansoni: A Sensitive Measure of Drug Action

1982 ◽  
Vol 68 (3) ◽  
pp. 353 ◽  
Author(s):  
David R. Semeyn ◽  
Ralph A. Pax ◽  
James L. Bennett
Keyword(s):  
Electrical Activity ◽  
Schistosoma Mansoni ◽  
Drug Action ◽  
Sensitive Measure

Fluorescent probes of acetylcholine binding sites—Indicators of drug action in Schistosoma mansoni

1976 ◽  
Vol 25 (22) ◽  
pp. 2529-2535 ◽  
Author(s):  
Gilbert R. Hillman ◽  
W. Brian Gibler ◽  
Shih-Hsi Chu
Keyword(s):  
Schistosoma Mansoni ◽  
Fluorescent Probes ◽  
Binding Sites ◽  
Drug Action

Schistosoma mansoni: a comparative study of schistosomula transformed mechanically and by skin penetration. Electrophysiological responses to a wide range of substances

Parasitology ◽  
1984 ◽  
Vol 88 (3) ◽  
pp. 477-489 ◽  
Author(s):  
D. P. Thompson ◽  
R. A. Pax ◽  
J. L. Bennett
Keyword(s):  
Electrical Activity ◽  
Schistosoma Mansoni ◽  
Morphological Changes ◽  
Potassium Cyanide ◽  
Skin Penetration ◽  
Suitable Material ◽  
Electrophysiological Responses ◽  
Wide Range ◽  
Experimental Treatments

SUMMARYVolume conducted potentials were recorded from schistosomula of Schistosoma mansoni transformed mechanically (MS) and by skin penetration (SS). The spontaneous electrical activity recorded consisted of bi and triphasic transients ranging from 20 to 200 μV in amplitude and 10 to 300 msec in duration. Low amplitude potentials occurred at a much greater frequency than large amplitude potentials, which appeared to correlate with peristaltic-like contractions of the schistosomulum's musculature. Electrical activity in the schistosomulum was highly sensitive to a number of agents believed to affect metabolic pathways, the neuromuscular system or the host/parasite interface of adult schistosomes. Among the most reactive substances were potassium antimony tartrate, eserine, poly-L-arginine and potassium cyanide. Over a wide range of experimental treatments, electrophysiological responses in schistosomula transformed from cercariae by mechanical decaudation and skin penetration were remarkably similar, supporting the notion that MS are suitable material for in vitro immunochemical, biochemical and physiological study. Some treatments, however, were more or less effective in altering electrophysiological activity and motility in the schistosomulum than in adult S. mansoni. This suggests that significant physiological alterations may occur during development from skin stage to adult parasites concomitant with immunochemical and morphological changes already known to occur.

Measurement of spontaneous neuronal membrane activity by time lapse confocal microscopy

1995 ◽  
Vol 53 ◽  
pp. 972-973
Author(s):  
R H. Selinfreund ◽  
A. H. Cornell-Bell
Keyword(s):  
Membrane Potential ◽  
Confocal Microscopy ◽  
Patch Clamp ◽  
Electrical Activity ◽  
Time Lapse ◽  
Neuronal Firing ◽  
Neuronal Membrane ◽  
Pituitary Cells ◽  
Patch Clamp Recording ◽  
Spontaneous Electrical Activity

Cellular electrophysiological properties are normally monitored by standard patch clamp techniques . The combination of membrane potential dyes with time-lapse laser confocal microscopy provides a more direct, least destructive rapid method for monitoring changes in neuronal electrical activity. Using membrane potential dyes we found that spontaneous action potential firing can be detected using time-lapse confocal microscopy. Initially, patch clamp recording techniques were used to verify spontaneous electrical activity in GH4\C1 pituitary cells. It was found that serum depleted cells had reduced spontaneous electrical activity. Brief exposure to the serum derived growth factor, IGF-1, reconstituted electrical activity. We have examined the possibility of developing a rapid fluorescent assay to measure neuronal activity using membrane potential dyes. This neuronal regeneration assay has been adapted to run on a confocal microscope. Quantitative fluorescence is then used to measure a compounds ability to regenerate neuronal firing.The membrane potential dye di-8-ANEPPS was selected for these experiments. Di-8- ANEPPS is internalized slowly, has a high signal to noise ratio (40:1), has a linear fluorescent response to change in voltage.

Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

1989 ◽  
Vol 47 ◽  
pp. 962-963
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan
Keyword(s):  
Nervous System ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
The Social ◽  
Social And Economic Development ◽  
Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

Fate of sperm membrane in fertilized ova

1993 ◽  
Vol 51 ◽  
pp. 40-41
Author(s):  
Frank J. Longo
Keyword(s):  
Electron Microscopy ◽  
Electrical Activity ◽  
Sea Urchins ◽  
Morphological Changes ◽  
Integrated System ◽  
Electrophysiological Recording ◽  
Experimental Conditions ◽  
The Status ◽  
Sperm Membrane ◽  
Temporal And Spatial

Measurement of the egg's electrical activity, the fertilization potential or the activation current (in voltage clamped eggs), provides a means of detecting the earliest perceivable response of the egg to the fertilizing sperm. By using the electrical physiological record as a “real time” indicator of the instant of electrical continuity between the gametes, eggs can be inseminated with sperm at lower, more physiological densities, thereby assuring that only one sperm interacts with the egg. Integrating techniques of intracellular electrophysiological recording, video-imaging, and electron microscopy, we are able to identify the fertilizing sperm precisely and correlate the status of gamete organelles with the first indication (fertilization potential/activation current) of the egg's response to the attached sperm. Hence, this integrated system provides improved temporal and spatial resolution of morphological changes at the site of gamete interaction, under a variety of experimental conditions. Using these integrated techniques, we have investigated when sperm-egg plasma membrane fusion occurs in sea urchins with respect to the onset of the egg's change in electrical activity.

Fit Vs Faint: Assessing Work Causation in “Idiopathic Fall” Cases

2014 ◽  
Vol 19 (5) ◽  
pp. 3-12
Author(s):  
Lorne Direnfeld ◽  
David B. Torrey ◽  
Jim Black ◽  
LuAnn Haley ◽  
Christopher R. Brigham
Keyword(s):  
Blood Flow ◽  
Electrical Activity ◽  
Loss Of Consciousness ◽  
Brain Electrical Activity ◽  
Medical Terminology ◽  
Scientific Analysis ◽  
Medical Causation ◽  
The Individual ◽  
The Brain ◽  
Current Science

Abstract When an individual falls due to a nonwork-related episode of dizziness, hits their head and sustains injury, do workers’ compensation laws consider such injuries to be compensable? Bearing in mind that each state makes its own laws, the answer depends on what caused the loss of consciousness, and the second asks specifically what happened in the fall that caused the injury? The first question speaks to medical causation, which applies scientific analysis to determine the cause of the problem. The second question addresses legal causation: Under what factual circumstances are injuries of this type potentially covered under the law? Much nuance attends this analysis. The authors discuss idiopathic falls, which in this context means “unique to the individual” as opposed to “of unknown cause,” which is the familiar medical terminology. The article presents three detailed case studies that describe falls that had their genesis in episodes of loss of consciousness, followed by analyses by lawyer or judge authors who address the issue of compensability, including three scenarios from Arizona, California, and Pennsylvania. A medical (scientific) analysis must be thorough and must determine the facts regarding the fall and what occurred: Was the fall due to a fit (eg, a seizure with loss of consciousness attributable to anormal brain electrical activity) or a faint (eg, loss of consciousness attributable to a decrease in blood flow to the brain? The evaluator should be able to fully explain the basis for the conclusions, including references to current science.

Gastric electrical activity in normal neonates during the first year of life. Effect of lactation with breast milk and formula

2001 ◽  
Vol 120 (5) ◽  
pp. A209-A209
Author(s):  
G RIEZZO ◽  
R CASTELLANA ◽  
T DEBELLIS ◽  
F LAFORGIA ◽  
F INDRIO ◽  
...  
Keyword(s):  
Breast Milk ◽  
Electrical Activity ◽  
First Year ◽  
Gastric Electrical Activity ◽  
First Year Of Life ◽  
Normal Neonates

Electrical Activity of the Small Intestine

1959 ◽  
Vol 37 (3) ◽  
pp. 268-281 ◽  
Author(s):  
Ε.E. Daniel ◽  
D.R. Carlow ◽  
B.T. Wachter ◽  
W.H. Sutherland ◽  
A. Bogoch ◽  
...  
Keyword(s):  
Small Intestine ◽  
Electrical Activity

The Relationship Between Texture Responses on the Rorschach and Adult Attachment

2010 ◽  
Vol 31 (1) ◽  
pp. 4-21 ◽  
Author(s):  
Kazunori Iwasa ◽  
Toshiki Ogawa
Keyword(s):  
Graduate Students ◽  
Adult Attachment ◽  
Japanese Population ◽  
Attachment Anxiety ◽  
Anxiety Scale ◽  
Self Report ◽  
Comprehensive System ◽  
Attachment Avoidance ◽  
Sensitive Measure ◽  
The Relationship

We examined the relationship between texture responses (T) on the Rorschach and adult attachment in the Japanese population. 47 Japanese undergraduate and graduate students (mean age = 20.16, SD = 1.87) completed a self-report adult attachment scale as well as the Rorschach. An ANOVA revealed that T = 1 participants were attached more securely than were other groups. T > 1 participants were more preoccupied with attachment and scored higher on an attachment anxiety scale than the T = 1 group. Although these results were consistent with the interpretation of the texture response according to the Comprehensive System (CS), the results obtained for T = 0 participants were inconsistent with hypotheses derived from the CS. T = 0 participants were high on preoccupied and attachment anxiety scores, although they were theoretically expected to be high on dismissing or attachment avoidance. These results indicated that – at least in Japan – T should be regarded as a sensitive measure of attachment anxiety.

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