Biomedical subjects
Publications and source records attributed to A Gurevitch.
Acanthamoeba is a recognized pathogen in the immunocompromised patient, commonly presenting as chronic or subacute encephalitis. However, cutaneous disease in the absence of CNS involvement is increasingly recognized, especially in the setting of chronic, nonhealing skin lesions in the patient with AIDS. We describe a patient with AIDS and cutaneous acanthamoebiasis and review our experience with treatment and diagnosis.
The syndrome of transient neurologic symptoms (TNS) after spinal lidocaine has been presumed to be a manifestation of local anesthetic neurotoxicity. Although TNS is not associated with either lidocaine concentration or dose, its incidence has never been examined with very small doses of spinal lidocaine. One hundred ten adult ASA physical status I and II patients presenting for arthroscopic surgery of the knee were randomly assigned to receive spinal anesthesia with either 1% hypobaric lidocaine 50 mg (Group L50) or 1% hypobaric lidocaine 20 mg + 25 microg fentanyl (Group L20/F25). Hemodynamic data, block height and regression, and time to first micturition and discharge were recorded. Follow-up phone calls were made by a blinded researcher at 48-72 h using a standardized questionnaire. Both groups had a median peak cephalad block level of T10. Lidocaine 50 mg was associated with a greater decrease in systolic blood pressure and a greater need for ephedrine. Time until block regression to the S2 dermatome (80 vs. 110 min) and outpatient time to void (130 vs 162 min) and discharge (145 vs. 180 min) were faster in the L20/F25 group. Complaints of TNS were found in 32.7% of the patients in the L50 group and in 3.6% of the patients in the L20/F25 group. We conclude that spinal anesthesia with lidocaine 20 mg + fentanyl 25 microg provided adequate anesthesia with greater hemodynamic stability and faster recovery than spinal anesthesia with lidocaine 50 mg. The incidence of TNS after spinal lidocaine 20 mg + fentanyl 25 microg was significantly less than that after spinal lidocaine 50 mg.
Explore the source record for details and available documents.
Pemphigus vulgaris, a bullous dermatosis, rarely occurs during pregnancy. Previous reviews have suggested that pemphigus has no significant effect on pregnancy. A case report of pemphigus occurring during pregnancy and resulting in an intrauterine death is presented. A reevaluation of the literature indicates that maternal pemphigus is associated with a significant risk of fetal mortality.
It is shown that when a human subject estimates verbally the duration of an array consisting of three intervals - two light intervals divided by a dark one - considerable underestimation is observed compared with estimates of the same duration in the control experiment. In case of separate estimation of the three intervals composing the array the sum of the estimates is much more precise even compared with estimates in the control. Perhaps in this case the system for time intervals estimation operates with two "internal clocks", each of which reads the duration of the dark and of the light intervals. In estimating the array of three intervals the subjects estimate the total array and they do not summate their separate estimations. It may be assumed that the system uses only one "clock" for measuring the duration of the total array.
A complex experiment is carried out in order to study the human ability to estimate and reproduce short time intervals in the 100-1000 ms range presented with light stimuli. The estimation task consists in verbal nomination of the time intervals presented to the subject in random order after preliminary training. In the production task the subject is expected to press a telegraph key simultaneously with the end of the light interval presented the duration of which is announced to him in advance. In the reproduction task the subject is to press the key a given time after the onset of the stimulus which duration is of 2 sec. The results show that in spite of the relatively good achievements in tasks involving verbal estimation of the duration of the intervals, the reproduction tasks are performed with systematic errors. In the production task the mean values of the response times decrease upon increasing of the required interval, while in the reproduction task they increase parallel with the increase of the required interval. Consequently, one and the same short time interval is perceived differently depending on the task to be performed, namely: verbal nomination, coincidence between hand movement and the end of the interval, or reproduction after verbal nomination.
The article reports the results of experiments on human ability to estimate time intervals separately or in groups of two intervals as elements of a three-interval array presented by two light signals separated by a dark interval. The first light interval is shown to be systematically overestimated compared with the second one. Moreover, the subjects usually ascribe a constant value to the dark interval. The double interval (light + dark or dark + light) proves to be underestimated compared with the case when estimation of the same intervals was required without estimation of a third interval. The additional task changes the estimations of the subjects. It may be claimed that the complexity of the problem is connected with definite changes in the average estimations of the subjects.
BACKGROUND AND OBJECTIVES: The hypotension following spinal anesthesia remains commonplace in cesarean delivery. Intrathecal opioids are synergistic with local anesthetics and intensify sensory block without increasing sympathetic block. The combination makes it possible to achieve spinal anesthesia with otherwise inadequate doses of local anesthetic. We hypothesized that this phenomenon could be used to provide spinal anesthesia for cesarean delivery while incurring less frequent hypotension. METHODS: Thirty-two women scheduled for cesarean delivery were divided into 2 groups of patients who received a spinal injection of either 10 mg of isobaric (plain) bupivacaine 0.5% or 5 mg of isobaric bupivacaine with 25 microg fentanyl added. Each measurement of a systolic blood pressure less than 95 mm Hg or a decrease in systolic pressure of greater than 25% from baseline was considered as hypotension and treated with a bolus of 5 to 10 mg of intravenous ephedrine. RESULTS: Spinal block provided surgical anesthesia in all patients. Peak sensory level was higher (T3 v T4. 5) and motor block more intense in the plain bupivacaine group. The plain bupivacaine patients were more likely to require treatment for hypotension (94% v 31%) and had more persistent hypotension (4.8 v 0.6 hypotensive measurements per patient) than patients in the minidose bupivacaine-fentanyl group. Mean ephedrine requirements were 23.8 mg and 2.8 mg, respectively, for the 2 groups. Patients in the plain bupivacaine group also complained of nausea more frequently than patients in the minidose bupivacaine-fentanyl group (69% v 31%). CONCLUSIONS: Bupivacaine 5 mg + fentanyl 25 microg provided spinal anesthesia for cesarean delivery with less hypotension, vasopressor requirements, and nausea than spinal anesthesia with 10 mg bupivacaine.