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Biomedical subjects

W C Duncan

Publications and source records attributed to W C Duncan.

At least 19 recordsLinked to original sources
PubMed1992

Fluoxetine decreases brain temperature and REM sleep in Syrian hamsters.

The antidepressant drug, fluoxetine (FLX), a selective serotonin reuptake inhibitor, was administered to Syrian hamsters, and its acute and chronic effects on EEG sleep and hypothalamic temperature were recorded. Acute fluoxetine treatment at doses of 5, 10, 20 and 40 mg/kg decreased REM sleep and hypothalamic temperature in a dose-dependent manner. It increased NREM sleep, and, at doses of 20 and 40 mg/kg, it increased wakefulness. At 40 mg/kg, it decreased motor activity. During chronic treatment, tolerance developed to FLX's REM sleep-inhibiting effects, but tolerance did not develop to FLX's hypothalamic temperature-decreasing effects. Chronic FLX treatment produced circadian phase-dependent decreases in temperature beyond those that were observed during acute treatment. The apparent dissociation during chronic treatment between FLX's temperature-lowering effects and its REM-decreasing effects might be related to long-term changes in 5HT receptor function or FLX pharmacokinetics.

Animals↗
PubMed1991

Clorgyline-induced reduction in body temperature and its relationship to vigilance states in Syrian hamsters.

The antidepressant drug clorgyline, a monoamine oxidase inhibitor (MAOI) that selectively inhibits MAO type A was administered chronically to Syrian hamsters. Twenty-four-hour EEG sleep and/or telemetered peritoneal temperature were monitored during selected sampling periods over four weeks. Chronic clorgyline treatment decreased rapid-eye-movement (REM) sleep time and body temperature during the first week. Incomplete tolerance to these effects developed during the second and third weeks. REM sleep and body temperature were correlated during chronic clorgyline treatment. Non-REM (NREM) sleep was elevated throughout chronic treatment. These results suggest that clorgyline's effects on REM and NREM sleep might be related to clorgyline's effects on thermoregulation and to the development of tolerance. However, causal relationships between clorgyline's effects on thermoregulation and the levels of REM and NREM sleep remain to be determined.

Animals↗
PubMed1990

Cutaneous signs of internal disease in the elderly.

The elderly are prone to several systemic diseases that have their own particular cutaneous markers. These include pruritus, pigmentary changes, and the various manifestations associated with diabetes mellitus, among others. Physician recognition of the cutaneous signs of internal disorders will prompt early diagnosis and prompt treatment of the primary disease.

Aged↗
PubMed1989

Longitudinal sleep EEG, temperature, and activity measurements across the menstrual cycle in patients with premenstrual depression and in age-matched controls.

After a 2-month evaluation period, eight women with moderate to severe premenstrual depression and eight age- and sex-matched controls underwent sleep electroencephalographic (EEG) and temperature recordings 2 nights a week over the course of one menstrual cycle. Overall, patients had more Stage 2 (%) sleep and less rapid eye movement (REM) sleep (% and minutes) than normal controls. Stage 3 sleep and number of intermittent awakenings varied with phases of the menstrual cycle. Temperature minima were earlier in patients compared with controls, but this difference was not statistically significant, and there was no significant effect of menstrual cycle phase on the timing of temperature minima. Wrist motor activity did not change during the menstrual cycle in patients or controls. Thus, in this sample of women with premenstrual depression, we did not find sleep EEG alterations similar to those reported in some patients with major depressive disorder. In light of the small number of subjects and the large individual variability, the absence of marked changes with the menstrual cycle may be a function of a Type II error.

Adult↗
PubMed1989

Failure of erythromycin to cure secondary syphilis in a patient infected with the human immunodeficiency virus.

The case presented here involves a 32-year-old homosexual man with human immunodeficiency virus seropositivity and secondary syphilis. Because of possible penicillin allergy, he was initially treated with erythromycin base by mouth. During four weeks of therapy, his cutaneous lesions worsened as did his systemic symptoms. Following desensitization and parenteral penicillin therapy, his cutaneous lesions and symptoms rapidly resolved. His VDRL titer fell appropriately.

Adult↗
PubMed1988

Chronic clorgyline treatment of Syrian hamsters: an analysis of effects on the circadian pacemaker.

Clorgyline, a type A monoamine oxidase inhibitor with antidepressant properties when administered to depressed patients, is often associated with disturbances of the human sleep-wake cycle. In order to assess its effects on the mammalian circadian system, this drug was administered chronically to Syrian hamsters. It was found to affect the hamster circadian system in four specific ways. Clorgyline increased the intrinsic period of wheel-running activity, altered the phase response curve to brief light pulses, altered the reduced waveform of running activity in animals maintained in light-dark cycles or constant darkness, and increased the activity-rest ratio in animals maintained in constant darkness. Our data support the interpretation that clorgyline exhibits direct or indirect input to the circadian pacemaker and alters the processing of photic information to the pacemaker.

Animals↗
PubMed1985

Sleep and circadian rhythms in affective patients isolated from external time cues.

Sleep electroencephalographic activity, circadian rhythms in motor activity and rectal temperature, and clinical state were monitored longitudinally in four affectively ill patients (two depressed, one manic, and one rapidly cycling between depression and mania) who lived in isolation from external time cues (zeitgebers) for 3 to 4 weeks. In these conditions it was possible to observe the intrinsic or free-running behavior of circadian pacemakers and thereby to test several hypotheses about the role of sleep and circadian rhythms in the pathogenesis of depression. No hypothesis was consistently supported by the results. We found that the intrinsic rhythm of a circadian pacemaker appeared to free-run with an abnormally fast frequency in one patient. No patient remained stably depressed during temporal isolation. Our experience suggests that this type of study can be carried out safely with appropriate precautions. Temporal isolation is a means to test decisively predictions of several chronobiological hypotheses about affective illness and should be applied to additional patients.

Adult↗
PubMed1984

Chromomycosis. The association of fungal elements and wood splinters.

In two separate specimens received for histopathologic examination, pigmented fungal elements were found within or on embedded wood splinters associated with a foreign-body reaction. The fungus was found to be in direct contact with the surrounding dermis. These findings support the concept of inoculation as a pathogenetic mechanism in cutaneous chromomycosis.

Aged↗
PubMed1982

Studies on the pathogenesis of the Jarisch-Herxheimer reaction: development of an animal model and evidence against a role for classical endotoxin.

The etiology of the Jarisch-Herxheimer reaction is unknown, but the reaction may result from toxic products of dead or dying treponemes reacting with sensitized syphilitic tissues. Because of similarities of spirochetes with gram-negative bacteria, endotoxin has been proposed as the responsible toxin. In 19 patients with syphilis, a reaction occurred in 15 (79%) during treatment with penicillin. Endotoxemia was not found by the limulus amoebocyte lysate test. All animal model of the Jarisch-Herxheimer reaction was developed in rabbits infected with Treponema pallidum. When treated with penicillin, 18 (78%) of 23 rabbits infected 18-29 days previously developed a reaction that resembled that in humans. Endotoxemia was not detected by the lysate test. After the reaction, rabbits were not refractory to the pyrogenic effects of endotoxin, and syphilitic rabbits rendered tolerant to endotoxin still developed fever when treated with penicillin. These data suggest that classical endotoxin is not the cause of the Jarisch-Herxheimer reaction.

Adult↗
PubMed1980

Bacterial interference of Neisseria gonorrhoeae by alpha-haemolytic streptococci.

Fifty pharyngeal isolates of alpha-haemolytic streptococci were tested against 20 cervical isolates of Neisseria gonorrhoeae for bacterial interference in vitro using the lawn-spotting method. Forty-seven (94%) isolates of streptococci showed inhibitory activity toward N gonorrhoeae, although nine of these were inhibitory to only one isolate of N gonorrhoeae. Isolates of N gonorrhoeae varied widely in their sensitivity to streptococci; the most sensitive were inhibited by 40 isolates of streptococci and the least sensitive by only 14 isolates. Species of Streptococcus found to inhibit growth of N gonorrhoeae were S mitis, S MG intermedius, S sanguis II, S mutans, and S morbillorum.

Adult↗
PubMed1979

Muscarinic supersensitivity: a possible model for the sleep disturbance of primary depression?

The sleep changes induced in normal volunteers following the administration of scopolamine on 3 consecutive mornings resemble many of the abnormalities observed in the sleep of patients with primary depression: increased sleep latency and reduced rapid eye movement (REM) latency, total sleep time, and sleep efficiency. Furthermore, in a multivariate discriminant analysis--previously shown to distinguish the sleep records of depresed patients from those of normal controls and insomniac patients--the records from baseline nights were selected as normal and those after scopolamine as predominately depressed. Those observations suggest to us that muscarinic supersensitivity in normals may function as a pharmacological model for the sleep disturbances of depression.

Depression↗
PubMed1979

REM architecture changes in bipolar and unipolar depression.

The authors compared total night sleep measures and REM sleep architecture values for normal control subjects (N = 36), unipolar depressed patients (N = 36), and bipolar depressed patients (N = 22). The unipolar and bipolar patients had significantly greater fragmentation of REM periods than control subjects, and bipolar patients showed greater fragmentation of REM periods than unipolar patients. In both the unipolar and bipolar samples, the duration of successive REM periods was related to the total number of REM periods during sleep.

Bipolar Disorder↗
PubMed1979

Hypopigmentation in alopecia mucinosa.

Alopecia mucinosa was found in the hypopigmented skin of two black patients. Alopecia mucinosa should be included in the differential diagnosis of hypopigmented papular skin lesions.

Alopecia↗
PubMed1978

Method for studying the role of indigenous cervical flora in colonisation by Neisseria gonorrhoeae.

A method for quantitating cervical flora has been evaluated statistically and used to study the bacterial flora of the cervix in 14 women sexually exposed to men with gonococcal urethritis. A comparison was made between those women who subsequently became colonised with Neisseria gonorrhoeae and those who did not to determine whether either total microbial populations or the different species present could be related to colonisation by N. gonorrhoeae. Two control groups of healthy women, one of patients from a public clinic and the other of patients from a private practice, were studied in the same way. Normal flora isolates were tested in vitro for antagonism or synergism toward N. gonorrhoeae or both. Cervical flora was characterised in all patient groups by wide variations between individuals, both in type and numbers of organisms. No significant differences were found in total bacterial populations or in the number of species isolated from the cervix between patient groups. Populations of N. gonorrhoeae ranged from less than 10 bacteria to log104.36. Only one normal flora isolate, a strain of Streptococcus viridans isolated from a woman exposed to but not infected by N. gonorrhoeae, demonstrated inhibition of growth towards N. gonorrhoeae.

Bacteriological Techniques↗
PubMed1978

Febrile neutrophilic dermatosis in acute myelogenous leukemia.

A 50-year-old woman with acute myelogenous leukemia on two occasions had fever and exquisitely tender, warm, erythematous, indurated to frankly bullous plaques on the face and upper extremities. Histologically, the lesions showed rather dense dermal infiltrates of mature polymorphonuclear leukocytes; special stains for bacteria and fungi were negative, as were all cultures for infectious agents. The lesions did not respond to antibiotics but cleared rapidly with systemic steroid treatment. Febrile neutrophilic dermatosis of acute myelogenous leukemia is believed to be a nonspecific reaction to the underlying malignant disease process. By prompt recognition of this entity, prolonged expensive courses of antibiotics may be avoided.

Female↗