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Biomedical subjects

R W Petry

Publications and source records attributed to R W Petry.

6 recordsLinked to original sources
PubMed1985

Monkey dander asthma.

We recently cared for two patients who experienced acute asthma with exposure to dander of the cotton top tamarin, a species of New World monkey. Both patients had serologic evidence for an IgE antibody to monkey dander as determined by RAST and a positive immediate skin test response to an extract prepared from monkey dander. Furthermore, by RAST we were able to determine that cotton top tamarin urine and newborn cotton top tamarin dander had antigens that reacted with IgE in the serum of the affected patients. Thus we report two patients with asthma to monkey dander that appears to be mediated by an IgE mechanism. We also found that serum from a subject exposed to another species of New World monkey, the capuchin, yielded a positive RAST to the cotton top tamarin, suggesting that allergenic cross-reactivity may exist between the two species.

Acute Disease↗
PubMed1982

Physiological action tremor of the ankle.

Comparisons were made between physiological tremor (PT), which is the involuntary oscillation produced when the leg is held in a plantarflexed position, and physiological action tremor (PAT), which is an involuntary oscillation associated with the voluntary slow raising and lowering of the heel. Frequency analysis using spectral techniques revealed a major frequency range of 6-9 Hz for PT and a major frequency range of 4-8 Hz for PAT. Computed root-mean-square (rms) acceleration values for each tremor type showed that the amplitude of PAT was significantly higher (2-5 times) than that of PT. This significant increase in amplitude occurred at specific stages of the voluntary movement. Major peaks in the spectral plots of the demodulated electromyogram signals of the soleus and tibialis anterior muscles corresponded to the frequency peaks seen with PAT.

Adolescent↗
PubMed1981

Electrophysiological changes of HSV-1-infected dorsal root ganglia neurons in culture.

Dissociated rat dorsal root ganglion cultures were infected with herpes simplex virus type 1 and studied electrophysiologically throughout the course of infection. Alterations in the electrical parameters of the action potentials of these neurons occurred as early as 4 hours post infection. The maximum rate of rise, spike amplitude, and overshoot were decreased, and the full width at half maximum and resting membrane potential were increased. At 6 hours post infection there is a movement back to normal values for these parameters. This reversal is transient, however, and the types of alterations seen at 4 hours post infection are more pronounced at 12 hours post infection. The first morphological alterations occur at 16 hours post infection, at which time less than 50% of the neurons impaled produced action potentials. Application of cyclohexamide to inhibit protein synthesis 1 hour post infection prevented electrophysiological changes normally seen at 4 hours and 6 hours post infection. It is concluded that the sodium conductance is specifically reduced by acute HSV infection, and that this reduction is attributed to viral specific or modified host cell protein synthesis.

Action Potentials↗
PubMed1981

Physiological action tremor: a basis for understanding alcohol withdrawal tremor.

Tremor measurements were obtained from 12 male volunteers before and during ethanol intoxication. The tremor recorded during extension and flexion of the hand is called physiological action tremor (PAT) and shares many of the same frequency, amplitude, and electromyographic characteristics reported for withdrawal tremor (WT). This report focuses on the relationships of these two tremors and presents further evidence to consider that PAT and WT might be controlled by the same mechanisms.

Action Potentials↗
PubMed1979

Computer-assisted mapping with the light microscope.

With the system described specific features in a histological section such as neuronal degeneration, specific cell types, or the silver grains of autoradiography can be accurately localized. It is simple to operate, and allows for data storage and retrieval. The system consists of a Zeiss Universal microscope equipped with stepping motor drives on the X and Y axes and interfaced to a PDP-12 computer equipped with a printer/plotter. The user controls the system through a joystick control box and teletype. In spite of magnification changes all points in the field remain constant relative to a point of origin selected at the beginning of the mapping sequence. Therefore, the outline and major features of a section are entered at low magnification while the detail of neuronal degeneration, for example, is added in its precise location at a higher magnification. The plotting of points can be done in either random fashion or in a systemized series of horizontal or vertical scans. A graphic display is available throughout the procedure and all maps are both printed on a Versatec printer/plotter and stored on a disk for future recall and analysis. Use of the system in plotting neuronal degeneration is described.

Animals↗