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Biomedical subjects

C R Gordon

Publications and source records attributed to C R Gordon.

At least 55 records · Page 3Linked to original sources
PubMed1992

Salivary secretion and seasickness susceptibility.

The salivary flow rate and composition of 2 groups of 31 subjects, one group at each extreme of the seasickness susceptibility scale, were compared. No significant differences were found between the two groups in flow rates and electrolyte concentrations of whole resting and stimulated saliva. Amylase activity and rate of secretion in resting saliva were significantly higher in subjects susceptible to seasickness as compared with nonsusceptible subjects. Also, the total protein rate of secretion in resting saliva was significantly higher in the susceptible group. The present findings could be explained in terms of higher sympathetic tone in subjects susceptible to seasickness, and salivary amylase levels might be recommended as an additional parameter in the evaluation of seasickness susceptibility.

Adult↗
PubMed1991

Three modality evoked potentials in Charcot-Marie-Tooth disease (HMSN-1).

Sixteen patients with dominant hereditary motor-sensory neuropathy type I (HMSN I), members of 5 families, underwent trimodality evoked potential studies. All patients had clinically normal optic nerves. History of deafness was present in 3 patients and sensory-neural hearing defect was found in 5 of 7 patients in whom audiometry was obtained. In 43.7 percent of the subjects significant prolongation of P100 of the VEP was found. Prolongation of N19 of the SEP was found in all 12 subjects examined. Significant bilateral prolongation of peak I of the ABEP was found in 37.5 percent of the subjects and in 50 percent of the ears examined: these findings indicated that in addition to peripheral nerves, the myelin of the optic and cochlear nerves is also affected in HMSN type I.

Adolescent↗
PubMed1991

Recurrent classic migraine attacks following transdermal scopolamine intoxication.

A 20 year old male naval crew-member suffering from sea sickness was treated with transdermal scopolamine (TS). After 5 months of continuous treatment, he developed scopolamine intoxication followed by the appearance of recurrent classic migraine attacks. He had never suffered from headache or migraine prior to TS intoxication. The migraine attacks comprised a prodrome of apathy, bad mood and loss of appetite lasting several hours. An aura of scintillating spots, left arm numbness and paresthesias lasting several minutes was followed by a severe throbbing unilateral headache with photophobia, sonophobia and nausea. After one year of repeated follow-up examination, he continued to suffer from the attacks once every 10 to 14 days, with no identified precipitating factors. We are not aware of similar cases in the medical literature. Although it is not possible to establish TS intoxication as a causal effect of the appearance of classic migraine in our patient, the temporal association and clinical course are very supportive of this assumption. Central nervous system neurotransmitter imbalance of cardiovascular alterations may possibly be implicated.

Administration, Cutaneous↗
PubMed1991

Diving-related inner ear injuries.

Diving-related inner ear barotrauma (IEB) and inner ear decompression sickness (IEDS) most often result in permanent severe cochleovestibular deficits, unless immediate diagnosis is reached and the correct treatment is commenced early. Nine cases of sport-diving-induced inner ear injuries that were referred to the Israeli Naval Hyperbaric Institute between October 1987 and September 1989 are presented with regard to evaluation, treatment, and follow-up. The diagnosis was IEB in five divers and IEDS in four. Explorative tympanotomy was carried out with remarkable results in two patients with IEB, while the remaining three were relieved by bed rest alone. Three of the four IEDS patients were recompressed according to the extended US Navy Table 6 with good short-term results. The role of complete otoneurological evaluation in the decision-making process leading to the correct diagnosis and treatment is emphasized.

Adolescent↗
PubMed1991

[Arterio-jugular difference of oxygen and intracranial pressure in comatose, head injured patients. I. Technical aspects and complications].

The monitoring of the comatose head injured patients is based on the recording of several data; the intracranial pressure measurements (ICP), associated with the arterial pressure recording, gives a good estimate of the cerebral perfusion pressure (CPP) but further information about the cerebral perfusion are needed. Based on the assumption that the cerebral metabolic rate is kept constant strong relationships exist between the cerebral blood flow (CBF) and the arterovenous difference of oxygen (AVDO2). In order to obtain samples of cerebral venous blood a catheter must be inserted in the internal jugular vein (IJ) with the tip of the cannula reaching the superior jugular bulb. In 224 patients we measured the ICP trough ventricular or subdural catheters; invasive measurement of the arterial pressure was also carried on in all the patients. In 45 patients we measured the AVDO2 and we tested the safety and the reliability of the jugular vein cannulation. During the insertion of the jugular catheters a slight increase of ICP, without any clinical significance, was recorded; in two cases (on a total of 45) accidental carotid puncture occurred. In 9 cases we tested the concordance of the oxygen content between the two IJs; looking at the mean values no statistical difference is detected between the two sides but in some cases relevant differences are recorded. In two cases we inserted the catheters more cranially, reaching a sinus of the cranial basis; the blood collected from these points carries less oxygen that the blood collected in the neck. The rate of infection in this series of ICP monitoring is very low (1.78%) and we had no bleeding at the moment of the insertion of the catheters. Since no significant complications related to the IJ cannulation were recorded we conclude that these techniques are safe and can be easily performed in the clinical setting. Further studies are required in order to investigate the clinical meaning of the differences in the IJs content of oxygen.

Adolescent↗
PubMed1990

Effect of murine recombinant interleukin-1 on brain oedema in the rat.

We investigated the effects of murine recombinant interleukin-1 (rIL-1, Du Pont) in vivo in the normal rat brain and here report both local and systemic effects of centrally administered rIL-1. Normal rats were given single or multiple atraumatic doses of either rIL-1 or and equal volume (5 microliters) of vehicle for control comparison. All dosages of intraparenchymal rIL-1 produced a uniform a hyperthermic response and concomitant lethargy. There was a related anorexia beyond fever duration. Histologic examination of intraparenchymal injection tracts revealed fibrillary whorls of oedema and a cellular infiltrate surrounding the rIL-1 tract, while similar changes were less prominent in control injection tracts. Repeated high doses of rIL-1 produced significantly higher concentrations of brain water as measured by the gravimetric technique. We conclude that rIL-1 is not only a potent chemoattractant, but is also an edigematic agent when administered in high doses.

Animals↗
PubMed1989

Salivary changes associated with seasickness.

Salivary composition and flow rate were measured in 13 healthy male volunteers exposed to a real seasickness situation. The flow rates of whole unstimulated and stimulated saliva were significantly reduced at sea in about 80% of the subjects. Salivary flow rate was negatively correlated with seasickness severity. These results contrast with the classic concept of increased salivation during seasickness. At sea, the potassium concentration of both unstimulated and stimulated saliva was significantly reduced, while sodium concentration was consistently elevated. The sodium and protein concentrations were positively correlated with seasickness severity. Thus, objective measurements of salivary flow rate and composition may be recommended for evaluation of the seasickness syndrome.

Adolescent↗
PubMed1989

Three-years' experience of transdermal scopolamine: long-term effectiveness and side-effects.

A study was carried out in 68 otherwise healthy male naval crew members to assess the long-term effectiveness and side-effects of routine transdermal scopolamine administration for the prevention of seasickness. The transdermal patches were applied to the mastoid process before each sailing and the subjects generally used 2 patches a week. Check-ups were made every 3 months over a period of 3 years. The average reported seasickness severity (on a scale of 0 to 7) after 6 months at sea prior to the administration of transdermal scopolamine was 5.64 +/- 0.11 (mean +/- S.E.M.), in comparison with 3.14 +/- 0.23 post-administration (p less than 0.001). A significant improvement was found in the self-estimated performance at sea whilst receiving the drug: 65.7% +/- 3.38% (mean +/- S.E.M.), compared to 25% +/- 2.24% beforehand (p less than 0.001). Contact dermatitis precluded the use of transdermal scopolamine in 3 (4.4%) subjects. The only other significant side-effect was dryness of mucous membranes. In conclusion, transdermal scopolamine was found to be effective in the prevention of seasickness and improvement of performance at sea during 3 years of follow-up and routine administration of the drug was not complicated either by severe side-effects or by performance disturbances.

Administration, Cutaneous↗
PubMed1988

Salivary changes associated with experimental motion sickness condition in man.

The effect of experimental motion sickness condition (rotation) on salivary flow and composition was studied in 34 healthy male volunteers. In most subjects, the flow rate of whole saliva was significantly decreased, while the potassium concentration was markedly increased during rotation. These results contrast with the classic reports of subjectively increased salivation in the first stages of motion sickness and may tentatively be explained in terms of sympathetic activation. The salivary protein concentration and secretion rate observed before and during rotation were consistently higher in those subjects categorized as moderately or severely sick during rotation. The salivary protein levels may perhaps be considered as an additional objective variable in the prediction of susceptibility to motion sickness.

Adolescent↗
PubMed1987

Nystagmus episodes related to sea sickness.

In order to test the possible presence of nystagmus during episodes of sea sickness, we performed electronystagmography (ENG) on nine subjects before and during sailing on a 35-ton vessel in a somewhat heavy sea. In addition, the accelerations of the x, y and z axes of the ship were also monitored and simultaneously recorded. Nystagmus was not detected in pre-sailing recordings, while all of the subjects demonstrated clear positional nystagmus during sailing. The nystagmus was episodic, direction-fixed and its intensity was greater in sea-sick than in non-sick subjects. Our findings suggest that the nystagmus recorded is labyrinthine in origin and stems from temporary peripheral vestibular dysfunction elicited by sea sickness.

Adolescent↗
PubMed1985

Day-night variations in urine excretions and hormones in dogs: role of autonomic innervation.

Under controlled light-dark cycle (LD 12:12) and two hydratory conditions, mongrel dogs display marked day-night variations in urine flow and in its constituents. Diurnal peaks were found in urine flow and sodium excretion, while nocturnal peaks were observed in osmolality and potassium excretion. Diuretic responses, after fluid intake, were consistently faster and higher during the day than during the night. Nocturnal increases were found in plasma antidiuretic hormone (ADH), in aldosterone and in plasma renin activity (PRA), which could partially explain the present results. In all dogs there was a decrease in ADH level in the early morning hours which could account for the increased urine flow and decreased osmolality observed at this time. Plasma cortisol did not show significant temporal variations throughout the 24-hour period. Kidney denervation did not alter the day-night variations in urinary flow, sodium and osmolality, but affected the pattern of potassium excretion. A neural control of potassium excretion pattern, probably mediated by PRA-aldosterone is tentatively postulated.

Aldosterone↗
PubMed1984

Effect of adrenergic blockers on the dog's sleep-wake pattern.

Different results are reported for the effects of an alpha and beta adrenergic blocker on the 24-hr sleep-wake patterns in dogs. While propranolol did not affect the 24-hr sleep-wake parameters, phentolamine significantly reduced delta sleep (stage 2), shortened the length of the sleep episodes, and decreased the number of REM episodes in each sleep-wake cycle. Phentolamine effects are explained by increased arousals within sleep episodes.

Animals↗
PubMed1983

Localization of choline acetyltransferase in laminae of the rat olfactory tubercle.

We report the distribution of choline acetyltransferase (ChAT) activity in the laminae of the rat olfactory tubercle. Within its posterior medical portion, the tubercle contains three parallel histological laminae that can be separated by cutting tangential sections from frozen tissue. ChAT was measured in homogenates of consecutive sections (16 micrometers) cut parallel to these laminae. The distribution of ChAT activity, as a function of tubercle depth, showed a broad peak centered at 500 micrometers from the ventral surface of the brain. Enzyme activity measured at this depth (85 pmol acetylcholine formed/microgram protein/h) was 2 1/2 times greater than that measured in the outermost, plexiform, layer. Stereotaxic injections of kainic acid (1 microgram in 1 microliter) made directly into the tubercle were used to eliminate intrinsic neurons. Three days after injection, histological examination revealed the almost total absence of neuronal cell bodies and the proliferation of glial cells. The greatest decreases in ChAT activity (50%) were seen at depths of 300-600 micrometers whereas no loss of activity occurred in the plexiform layer.

Animals↗