Search PubMed⌕ Search

Biomedical subjects

W R Wilson

Publications and source records attributed to W R Wilson.

At least 397 records · Page 22Linked to original sources
PubMedDate not supplied

NMDA agonists and antagonists alter the hypnotic response to ethanol in LS and SS mice.

Involvement of glutamate neurotransmission in the differential response of long-sleep (LS) and short-sleep (SS) mice to acute ethanol was examined by measuring the effect of centrally administered glutamate receptor agonists and antagonists on blood ethanol concentration (BEC) at loss of righting response following intragastric administration of ethanol. NMDA coinjected with glycine, and quinolinic acid (QA), decreased sensitivity to ethanol in both lines of mice. SS mice were more sensitive to QA than were LS. The NMDA antagonists 2-amino-5-phosphonovaleric acid (APV), MK-801 and an inhibitor of glutamate synthesis, methionine sulfoximine, increased sensitivity to ethanol in both lines of mice. MK-801 effects were line dependent with SS being more sensitive. In addition, coinjection of APV, Mg++ or Zn++ with QA blocked the decrease in sensitivity seen with QA alone. These results demonstrate that NMDA agonists and antagonists alter the acute hypnotic response to ethanol in both LS and SS mice, and support the hypothesis that ethanol exerts its effects in part by altering glutamatergic neurotransmission.

Animals↗
PubMedDate not supplied

Different levels of [3H]MK-801 binding in long-sleep and short-sleep lines of mice.

The long-sleep (LS) and short-sleep (SS) lines of mice were selectively bred for differential sensitivity to the hypnotic effects of ethanol. Several studies suggest that excitatory amino acid receptor systems are involved in these genetically determined differences in sensitivity to ethanol. The experiments described in this article examine further the potential role of NMDA excitatory amino acid receptors in genetically determined differences in hypnotic sensitivity to ethanol by measuring [3H]MK-801 binding in eight brain regions of LS and SS lines of mice. Significantly greater levels of binding were found in SS hippocampus and striatum. Binding levels in the remaining brain regions revealed no significant between-line differences. Affinity differences between regions were seen but no between-line differences in affinity were found in any brain region. These findings lend support to the hypothesis that differences in NMDA receptor systems are part of the genetically determined biochemistry that produces differential hypnotic sensitivity to ethanol in LS and SS mice.

Animals↗
PubMedDate not supplied

Electronystagmographic findings in idiopathic sudden hearing loss.

The electronystagmographic findings for 116 patients with unilateral idiopathic sudden hearing loss (ISHL) were analyzed. For the purpose of the study, three groups were formed: patients with normal electronystagmographic (ENG) findings; patients with mild to moderate vestibular injuries consisting of spontaneous horizontal nystagmus or directional preponderance; and patients with severe vestibular injuries indicated by reduced vestibular responses, including paresis of the semicircular canal or lack of response to caloric testing. Clinical and audiologic findings were compared. High correlations were found between both subjective vertigo and abnormal ENG findings and the presence of profound hearing loss at the onset of ISHL. There was an inverse relationship between recovery from ISHL and the ENG findings, namely, as the severity of the vestibular injury increased, the percentage of patients who achieved recovery decreased. Patients with abnormal ENGs had a greater mean hearing loss at onset of ISHL and less mean recovery of hearing than did patients who had normal ENG findings. In addition, patients who had abnormal ENG findings recovered less fully from hearing loss in the high frequencies than from those in the low frequencies owing to the proximity of the basilar turn of the cochlea to the vestibular sense organ.

Adolescent↗
PubMedDate not supplied

Predicting recovery from idiopathic sudden hearing loss.

The probability of recovery from idiopathic sudden hearing loss depends on many factors, including patient age, presence of vertigo, audiogram type at diagnosis, and electronystagmographic test results. The authors present a model for calculating the probability of patient recovery based on the combined effects of risk factors determined for these variables. Data collected from 123 patients with "profound" or "moderate" sudden hearing losses are used to illustrate the model. Interrelationships among the prognostic factors and their relative importances in predicting hearing recovery are discussed.

Adolescent↗
PubMedDate not supplied

Paranasal sinus mucormycosis in an immunologically competent host.

A case of paranasal sinus mucormycosis in an immunocompetent patient is reported. After an extensive evaluation, no evidence of either diabetes mellitus or underlying immunologic abnormality was found. The combination of excisional surgery and amphotericin B therapy resulted in an excellent response. High-resolution axial and coronal computed tomography was useful in both planning treatment and monitoring the response to therapy.

Adult↗
PubMedDate not supplied

Efficacy of an H1 antagonist, astemizole, for chronic allergic rhinitis.

Astemizole, a new histamine H1 receptor antagonist, was tested in a double-blind cross-over comparison study with chlorpheniramine maleate, a very effective conventional H1 antagonist, in patients with chronic allergic rhinitis. Astemizole was found to be equally effective, yet there was a significant decrease in the side effects of sleepiness (P less than .01) and dry mouth (P less than .05). Astemizole has a completely different structure and binding curves from terfenadine. It is approved for clinical use in the United Kingdom, Canada, and many European countries.

Astemizole↗
PubMedDate not supplied

Ethanol and glutamate effects on intracellular magnesium.

Acutely dissociated rat brain cells were loaded with the magnesium-sensitive fluorescent dye furaptra. Stimulation with varying concentrations of GLU + 1 microM GLY produced a concentration-dependent increase in free intracellular magnesium ([Mg2+]i) that was not dependent on the presence of extracellular Mg2+. Ethanol (50 mM) did not significantly inhibit GLU/GLY-stimulated increases in [Mg2+]i. However, ethanol alone significantly increased baseline [Mg2+]i.

Animals↗
PubMedDate not supplied

Anaerobic bacteremia: decreasing rate over a 15-year period.

At the Mayo Clinic, the number of cases of anaerobic bacteremia decreased 45% between 1974 and 1988. In addition, the percentage of blood cultures positive for anaerobes decreased significantly even though the total number of blood cultures performed increased. The number of anaerobic bacteremias per 100,000 patient-days also declined over the 15-year period. Organisms of the Bacteroides fragilis group ranked third in frequency with respect to other organisms that caused aerobic and anaerobic bacteremia in 1974 but ranked only seventh in 1988 and caused slightly less than one-half of the anaerobic bacteremias. The mechanisms responsible for these changes are unclear but might relate to earlier recognition and treatment of localized anaerobic infection, widespread preoperative use of agents prior to bowel surgery, and use of broad-spectrum antimicrobial regimens that include agents with activity against anaerobes.

Bacteremia↗
PubMedDate not supplied

Clinical-histologic-microbiologic analysis of 419 lymph node biopsy specimens.

The results of culture and histopathologic examination of 419 lymph node biopsy specimens obtained from 414 patients in 1978-1983 were correlated with clinical histories. The clinical diagnosis was lymphadenopathy of unknown etiology in 113 cases, sarcoidosis in 93, malignant lymphoma in 86, metastatic carcinoma in 17, histoplasmosis in 18, tuberculosis in 13, and other miscellaneous conditions in 79. All but two clinically significant microbial isolates from lymph nodes were either mycobacteria or fungi: the only exceptions were staphylococcal isolates from two children with lymphadenitis. Of 66 lymph nodes associated with bacterial, mycobacterial, or fungal disease, 48 included granulomatous and/or acute inflammatory lesions. Of 33 lymph nodes that were culture-positive, two had histologic evidence of lymphoid hyperplasia, and the remainder included granulomatous and/or acute inflammatory lesions. With one exception, lymph node cultures in immunocompetent patients were positive only when there was a granuloma and/or an acute inflammatory lesion in the tissue. On the basis of these findings, it was concluded that lymph nodes from immunocompetent patients should be cultured only when a granuloma and/or an acute inflammatory lesion are detected and that the cultures can be limited to mycobacteria and fungi.

Adolescent↗
PubMedDate not supplied

Factors predictive of seizures among intensive care unit patients with gram-negative infections.

From the medical records of 238 intensive care unit (ICU) patients who had infections with gram-negative pathogens commonly associated with serious illness, we developed a predictive score of clinical risk factors for seizures. To evaluate the predictive ability of this score, we applied it to a separate population of 645 seriously ill hospitalized patients with similar gram-negative infections who were in antibiotic clinical trials. The patients at highest risk were classified into one of the following three categories: (a) patients with major central nervous system (CNS) insults (CNS surgery, hemorrhage, infection, or other lesion within 1 month before hospital admission or any history of CNS neoplasia), (b) patients with a predisposing factor (renal impairment or a history of seizures) plus a precipitating factor (anoxic encephalopathy/coma or an acute hypotensive episode), and (c) patients with both renal impairment and a history of seizures. Receiver operating characteristic (ROC) curves were calculated in each of the two populations. The area under the ROC curve (AUC) represents the probability that the score would rank a randomly chosen patient who subsequently had a seizure as having had a greater prior level of seizure risk than a randomly chosen patient who did not experience a seizure. The AUC was 0.87 (SE = 0.05) for the original population used to develop the score and 0.81 (SE = 0.04) for the population used for the validation study. The clinical risk score, based on readily available information, provides a useful means to identify among seriously ill infectious disease service patients, those who are at highest risk for seizures. It also serves as a baseline for evaluating the non-drug-related risk factors for seizures in patients treated with antibiotics.

Adult↗
PubMedDate not supplied

Rapid, atraumatic method for obtaining nasal mucus samples.

Disposable cellulose acetate sponges, properly placed in the nose, provide a rapid method of stimulating the production of nasal mucus to be obtained for study. There is little trauma to the nasal mucosa, thus minimizing the risk of contamination of samples with serum or cells. The mucus is not diluted, and therefore, quantitative measurements of immunoglobulins and other substances can be made.

Acetates↗
PubMedDate not supplied

Treatment of syphilitic hearing loss. Combined penicillin and steroid therapy in 29 patients.

Twenty-nine patients with presumed syphilitic hearing loss, either congenital or acquired, were treated on one or more occasions according to a three-month protocol using penicillin and prednisone. Changes in hearing were carefully followed during treatment and for at least one year thereafter. Of 58 ears studied in 29 patients, 19 demonstrated significant partial improvement in hearing during treatment. However, 11 ears returned to pretreatment hearing levels after therapy, and only 8 ears, or 15%, maintained the hearing gains one year later. Enhanced discrimination occurred more commonly than gains in pure tone threshold. Long-term alternate day prednisone therapy was required to sustain hearing improvement in a small number of patients.

Adult↗
PubMedDate not supplied

Electronystagmography in congenital and acquired syphilitic otitis.

This study is an analysis of the electronystagmogram (ENG) changes in 17 patients with luetic vestibular disease with early and late acquired syphilis and congenital syphilis. Vestibular disturbances occurred in 80% of patients with luetic otitis. Among these patients the ENG gives signs of peripheral rather than central vestibular injury, and reduced vestibular response to caloric stimulation is the most common finding. Congenital syphilis patients have the greatest dysfunction, both in degree of ENG changes and incidence of bilaterality. We found no correlation between FTA-ABS levels and the amount of hearing impairment or vestibular injury. Treatment with penicillin and steroids had a beneficial subjective effect upon the symptoms of vertigo in over half the patients.

Adult↗
PubMedDate not supplied

Study of ventilation testing with electronystagmography.

Provocation tests such as head shaking and positional tests, as well as hyperventilation, have been used routinely by many laboratories to elicit nystagmus during an electronystagmogram. We added oxygen testing to this routine battery and compared the results with hyperventilation and other forms of provocative testing. Hyperventilation and oxygen testing are unique in that they probably affect the vestibular system by changing the levels of oxygen and carbon dioxide supplied. Hyperventilation in theory would decrease available oxygen, while oxygen testing would cause an increase. In a study of two groups totaling over 700 patients, we found that oxygen testing is only occasionally positive (2.5%) and is of little practical value. Hyperventilation testing is positive 8% of the time but rarely alone, and has no localizing value. When hyperventilation and oxygen tests are both positive, the nystagmus may be in opposite directions. In 6 of 18 patients with acoustic neurinomas, hyperventilation produced transitory direction-changing nystagmus.

Adult↗
PubMedDate not supplied

The implication of viruses in idiopathic sudden hearing loss: primary infection or reactivation of latent viruses?

Seventy-seven paired serum samples from patients with known idiopathic sudden hearing loss (ISHL) were surveyed using viral serologic methods. Fifteen different viruses and Mycoplasma pneumonia were the agents tested. We determined an incidence of 65% (49/77) of documented significant seroconversions to one or more of the agents surveyed. Multiple agents were involved in 24 of the 49 positive cases we studied. Influenza virus Group B in 14 (18%) and rubeola in 12 (16%) were the most prevalent, followed by Herpes simplex type 1 in 6 (8%), mumps in 6 (8%), influenza Group A3 in 6 (8%), rubella in 5 (7%), and cytomegalovirus (CMV) in 5 (7%).

Adolescent↗