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F K Hoehler

Publications and source records attributed to F K Hoehler.

29 records · Page 2Linked to original sources
PubMed1981

A quantitative model of the Hoffmann reflex.

Electrical stimulation of the human posterior tibial nerve elicits two separate electromyographic responses. The shorter latency response results from electrical activation of motor axons and is termed the direct motor (M) response, while the longer latency response results from activation of stretch receptor afferents of the monosynaptic reflex arc and is termed the Hoffmann (H) reflex. At high stimulus intensities, the H reflex is either greatly reduced in size or completely extinguished, presumably by antidromic impulses elicited by stimulation of the motor nerve. In most subjects, a simple quantitative model appears to account for this extinction. In this model: (1) the M response is used to estimate the number of antidromic impulses; (2) the H reflex is used to estimate the number of orthodromic impulses which escape collision; (3) the maximum size of the M response is used to indicate the size of the motoneuron pool; and (4) it is assumed that antidromic impulses collide in a random fashion with orthodromic impulses in the motor nerve.

Electromyography↗
PubMed1980

Effect of the interstimulus (CS-UCS) interval on hippocampal unit activity during classical conditioning of the nictitating membrane response of the rabbit (Oryctolagus cuniculus).

Neuronal activity (multiple unit) was recorded from the dorsal hippocampus during classical conditioning of the nictitating membrane response in the rabbit. Groups of subjects were trained with conditioned stimulus/unconditioned stimulus (CS-UCS) interstimulus intervals of 250 msec, 150 msec, or 50 msec, and an additional group received unpaired presentations of the CS and UCS, with a tone CS and a corneal air puff UCS. Increased hippocampal unit activity and nictitating membrane conditioned responses (CRS) occurred only in the 250 msec and 150 msec groups. Both the temporal distribution of hippocampal unit activity and the averaged CR topographies were strongly and similarly influenced by the CS-UCS interval, with both neuronal and behavioral response peaks occurring near the time of UCS onset. The peak of hippocampal unit activity preceded the peak of the nictitating membrane CR by 30-60 msec. When the 250 msec group was shifted to a CS-UCS interval of 500 msec, the peaks of both the hippocampal unit response and the behavioral CR topography shifted in the same direction. The shift appeared to occur sooner in the hippocampal unit response. It is suggested that the hippocampus may function to provide a "temporal map" for learned behaviors.

Animals↗
PubMed1979

Cimetidine in the treatment of acute alcoholic pancreatitis. A randomized, double-blind study.

A double-blind study was made of the comparative effectiveness of cimetidine in the treatment of acute alcoholic pancreatitis. The study group was composed of 27 patients with acute episodes of alcoholic pancreatitis of mild to moderate severity. The patients were randomized into 2 groups, either receiving cimetidine, 300 mg four times daily or a placebo. Both groups were given intravenous fluids and meperidine hydrochloride (Demerol) as needed. There were no significant differences between the 2 groups as measured by a variety of clinical and laboratory parameters. The mean value of the daily serum amylase in the placebo group declined steadily to normal; hyperamylasemia in this group persisted for 52 +/- 11 hr (mean +/- SE). By contrast, serum amylase in the cimetidine group peaked at 24 hr after the start of treatment and remained abnormal slightly longer; the duration of hyperamylasemia in the group was 69 +/- 10 hr. It is concluded that: (1) cimetidine is not superior to a placebo in the management of mild to moderately severe acute alcoholic pancreatitis and (2) serum amylase activity in patients with acute alcoholic pancreatitis given cimetidine tends to be greater and hyperamylasemia is of somewhat longer duration than in those treated with a placebo.

Acute Disease↗
PubMedDate not supplied

Medical registers as historical controls: analysis of an open clinical trial of inosiplex in subacute sclerosing panencephalitis.

Clinical trials of treatments for rare or fatal diseases must often use historical rather than randomized concurrent controls. Randomized trials may not be possible if (1) the number of patients available is quite small, (2) ethical considerations discourage the assignment of patients to control treatments known to be ineffective or (3) some evidence suggests that the proposed new treatment is substantially more effective than the control. We suggest that, when randomization is not feasible, adequately maintained medical registers can serve as a source of control patients. Investigators must pay careful attention to prognostic factors that might bias the results. However, statistical techniques for controlling such bias exist and, if these are properly employed, registry-derived historical controls can be used to evaluate the effectiveness of treatment.

Clinical Trials as Topic↗
PubMedDate not supplied

Double responding in classical nictitating membrane conditioning with single-CS dual-ISI training.

Rabbits were classically conditioned under a single-CS dual-ISI paradigm. Contrary to a previous experiment by Frey (1970), a separate CR was conditioned at each interstimulus interval (ISI), producing a double response (DR) on long-ISI trials. Further experiments indicated that DR development is facilitated by (a) circumorbital US-location and (b) relatively high US-intensity. However, subsequent shifts to nonoptimal conditions did not produce substantial decreases in DR frequency. The presence of DRs appears to be readily amenable to interpretation in terms of a Pavlovian stimulus-trace mechanism in which the US becomes associated with a particular temporal portion of the CS. An instrumental-response-shaping hypothesis of classical conditioning can explain these data only if the hypothetical reinforcement mechanism is assumed to be considerably more complex than had previously been supposed.

Animals↗
PubMedDate not supplied

Attenuation of morphine analgesia by alpha-MSH, MIF-I, melatonin and naloxone in the rat.

In two experiments the effects of the pituitary peptide alpha-MSH, the hypothalamic tripeptide MIF-I (P-L-G-NH2) and the pineal hormone melatonin were investigated on the attenuation of morphine analgesia measured by a tail flick test. In Experiment 1, alpha-MSH had minimal effect on morphine analgesia, whereas, MIF-I and melatonin clearly delayed the onset of morphine analgesia, and melatonin also shortened the duration of analgesia. Experiment 2 was designed to investigate the possible synergistic effect of MIF-I and melatonin. The combined treatment of MIF-I and melatonin significantly delayed the onset of morphine analgesia, and melatonin alone shortened the duration of analgesia. The relationships among the pituitary, hypothalamus and the pineal for the modulation of pain and response to morphine were discussed.

Analgesia↗
PubMedDate not supplied

Management of hymenoptera sting anaphylaxis: a preventive medicine survey.

The evaluation of aftercare instructions given to patients suffering from hymenoptera sting anaphylaxis was the objective of the study. Part of this evaluation included asking the physicians questions to examine the knowledge on which they based their aftercare instructions. Survey questionnaires were completed by 124 of 174 (71%) physicians who worked in an emergency department or urgent care center. Fifty-eight percent of the physicians never provided written avoidance instructions, 24% provided or prescribed anaphylaxis ID bracelets, 44% referred all of their patients to an allergist for further evaluation, and 73% reported prescribing an Epi-pen or Ana-kit to all hymenoptera sting anaphylaxis victims. Twenty-four percent of physicians did not know where to obtain anaphylaxis identification bracelets. This survey demonstrates that a substantial number of physicians practicing emergency medicine are not providing appropriate aftercare instructions to patients, and substantiates the need for educational efforts to increase the awareness of physicians concerning the implications of hymenoptera allergy and the value of proper preventive measures.

Anaphylaxis↗