PubMed Health⌕ Search

Biomedical subjects

A Shupak

Publications and source records attributed to A Shupak.

At least 19 recordsLinked 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

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

On the transmission of sound generated by an electromagnetic device from the mastoid process to the petrous bone.

An electromagnetic device (EMD) for sound transmission from the mastoid process to the petrous part of the temporal bone was designed, built, and analyzed. A theoretical model was developed in order to predict the EMD acoustical performance and the distortion caused by skull bones. This model enabled the investigation of various technical improvements and calibration options. The EMD was miniaturized by using rare earth magnets in the construction of both external transmitter and internal receiver. In vitro implantation of the internal receiver into the mastoid process was carried out by simple mastoidectomy techniques. The input and output powers of the system, including the EMD and skull bones components, were measured and the power transfer function was calculated. The sound, which was generated by the EMD and transmitted through the dry as well as simulated cadaver skull, had high fidelity in spite of some vibratory distortion at the lower sonic frequencies. Results suggest that further development of hearing aids based on electromechanical sound transmission should take into account the specific acoustic response pattern of the skull bones.

Bone Conduction↗
PubMed1991

Pressure chamber tympanometry in diving candidates.

The currently recommended examination for diving fitness ascertains middle ear autoinflation ability only under surface pressure conditions. The purpose of our study was to document and quantify middle ear pressure equalization failure during simulated dives among diving candidates who had otherwise met the otologic criteria for diving fitness. Forty-two candidates for regular naval diving activity were included in the study. Tympanograms of both ears at 1 and 1.1 absolute atmospheres (ATA) were taken inside a pressure chamber with the subjects in two positions: seated and supine. At a pressure of 1 ATA, type A tympanograms were found in all 84 ears examined. At a pressure of 1.1 ATA, with subjects in the upright position, 19 (22.9%) of the ears had type C and 2 (2.4%) type B tympanograms, while with subjects recumbent during descent, 6 of the ears (7.2%) had type C and 7 (8.4%) type B. Our results suggest that successful autoinflation at surface ambient pressure does not necessarily reflect middle ear pressure equalization ability during descent in a dive.

Acoustic Impedance Tests↗
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↗
PubMed1990

Vestibulo-ocular reflex as a parameter of seasickness susceptibility.

The vestibulo-ocular reflex (VOR) is known to be modulated in response to changing vestibular and optokinetic stimuli. The purpose of this study was to investigate possible relationships between VOR and future susceptibility and habituation to seasickness. Thirty candidates for future maritime service were exposed to a series of yaw axis smooth harmonic accelerations before and after 6 months of regular sailing, and their VOR gain and phase responses were recorded. Seasickness severity was estimated after 1 and 6 months of service by a questionnaire. We conclude that VOR gain at 0.01 Hz may serve as a physiologic correlate helping to predict seasickness susceptibility, and that the increase in phase lead at 0.02 Hz may mark the habituation process to sea conditions.

Acceleration↗
PubMed1990

Inner ear decompression sickness following a shallow scuba dive.

Inner Ear Decompression Sickness (IEDCS)--manifested by tinnitus, vertigo, nausea, vomiting, and hearing loss--is usually associated with deep air or mixed gas dives, and accompanied by other CNS symptoms of decompression sickness (DCS). Early recompression treatment is required in order to avoid permanent inner ear damage. We present an unusual case of a scuba diver suffering from IEDCS as the only manifestation of DCS following a short shallow scuba dive, successfully treated by U.S. Navy treatment table 6 and tranquilizers. This case suggests that diving medical personnel should be more aware of the possible occurrence of IEDCS among the wide population of sport scuba divers.

Adult↗
PubMed1989

Hyperbaric oxygenation for necrotizing (malignant) otitis externa.

Two patients with extensive necrotizing otitis externa have been treated by hyperbaric oxygenation. One patient had facial nerve palsy and the other suffered from skull base involvement. Due to severe side effects, the preferred combined intravenous antibiotic therapy was changed to monotherapy in one case and completely withdrawn in the second. This was done before the commencement of hyperbaric oxygenation, while the necrotizing infection was still active. Hyperbaric oxygenation therapy was followed by complete resolution of the necrotizing otitis externa, which did not recur. The pathogenesis of the disease and mechanisms by which hyperbaric oxygenation might be of benefit are described. We conclude that hyperbaric oxygenation should be considered as adjuvant therapy for necrotizing otitis externa whenever a therapeutic pressure chamber is available.

Aged↗
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↗
PubMed1987

Tonsillar leiomyoma.

Tumors of smooth muscle origin are rare in the oral cavity. To date, only eighty-three cases of oral leiomyomas have been reported. A first case of tonsillar leiomyoma in a 73-year-old male is presented. The theories of origin and the various histologic types of oral leiomyomas are discussed. Leiomyoma can easily be confused with other spindle-cell tumours. Special stains are necessary to reach a correct diagnosis. It is sometimes difficult to differentiate benign leiomyoma from malignant leiomyosarcoma. The use of mitotic figure count to indicate malignant behaviour is not always reliable. The need for wide surgical excision of the tumour, complete sectioning and examination of the specimen and meticulous follow-up of the patient for evidence of recurrence are emphasized.

Aged↗
PubMed1986

Necrotizing fasciitis.

Necrotizing fasciitis was diagnosed in 16 patients during the years 1980 to 1984. All patients were managed by a uniform protocol consisting of radical excisional surgery, intravenous antibiotics, and hyperbaric oxygen therapy. An overall mortality rate of 12.5% was achieved. In view of the encouraging results, this therapeutic regimen is highly recommended.

Adult↗