Dopamine transporter regulation during four nights of REM sleep deprivation followed by recovery--an in vivo molecular imaging study in humans.

OBJECTIVES: To assess the influence of total or selective REM sleep deprivation on the dopamine transporter (DAT) densities and sleep patterns of healthy volunteers. DESIGN: Prospective study. SETTING: Evaluation of polysomnography recordings and DAT density after 4 nights of selective REM sleep deprivation followed by 3 nights of sleep recovery compared to a control group and a group that was subjected to 2 nights of total sleep deprivation. Single positron emission computed tomography and [99mTc]TRODAT-1 were used to assess the cerebral DAT density in the striatum at baseline, after REM sleep deprivation and total sleep deprivation as well as after sleep recovery. Blood was collected daily to examine prolactin and estradiol levels, which were correlated with dopaminergic activity. PATIENTS OR PARTICIPANTS: Thirty healthy male volunteers ranging from 19 to 29 years of age were randomly assigned to one of three experimental groups after giving written informed consent (10 non-sleep deprived, 10 total sleep deprived, and 10 REM sleep deprived). MEASUREMENTS AND RESULTS: Four nights of REM sleep deprivation and 2 nights of total sleep deprivation induced distinct and heterogeneous patterns of sleep recovery. No significant modulation of DAT availability was observed within groups. In the recovery nights, changes in cortisol, prolactin and estradiol concentrations were significantly correlated with specific sleep stages in the total and REM sleep deprived groups. In addition, DAT density was positively correlated with estradiol concentration and inversely associated with SWS latency only after total sleep deprivation. CONCLUSION: Our study demonstrates that although sleep deprivation did not promote significant alterations in DAT density within the striatum, there were significant correlations among transporter availability, hormonal concentrations and sleep parameters.

Lymphscintigraphic evaluation of manual lymphatic drainage for lower extremity lymphedema.

To evaluate the effect of manual lymphatic drainage on technetium-99m-labeled dextran (99mTcDx) transport, 16 patients with lymphedema of lower extremities underwent two lymphscintigraphy exams by injecting 99mTcDx intradermally into the first interdigital space of the affected extremity. The first was a control examination at rest followed by an examination which included a manual lymphatic drainage session after the injection of the 99mTcDx. Images were obtained 45 minutes and three hours after the injection of the radioisotope. Extremity volumes were also measured before and after the drainage session. The findings from the examinations were assessed in a quantitative, semiquantitative and qualitative manner and compared without and with drainage. The analyses of the extremities' circumference before and after the drainage by paired t-test revealed a significant decrease. The analyses of the quantitative, semi-quantitative and qualitative evaluations evidenced no significant difference, without or with drainage, within the 45-minute and three-hour periods. Thus, manual lymphatic drainage caused an effective reduction in the circumference of the extremities but did not have a significant effect in the transport of 99mTcDx.

Evaluation of two 99mTc-DTPA radioaerosols with different characteristics in lung ventilation studies.

Two radioaerosol preparations, TechneScan -DTPA (99mTc-DTPA, 40 mCi/3 ml; IPEN-CNEN, São Paulo, SP, Brazil) and TechneScan -DTPA/AEROSOL (99mTc-DTPA/A, 15 mCi/1.5 ml with 0.5 ml ethanol; Mallinckrodt Medical, St. Louis, MO, USA), were compared in pulmonary ventilation studies in terms of total radiocounts and clearance after inhalation. An aerosol with ethanol is supposed to better distribute the radioparticles in the lungs. Twenty normal nonsmoking volunteers (10 men and 10 women), mean age of 23.2 years (range: 20 to 35 years), were studied. Images were obtained immediately and 30, 60 and 90 min after inhalation. Total and regional counts were obtained and the clearance half-lives of both lungs were determined. There was no difference in total counts between the two types of radioaerosol at any time (mean of approximately 188,000 cpm for male and female subjects at time zero in both aerosols). The highest count was obtained in the middle region of both lungs (P<0.001) with both preparations. The clearance half-life did not differ between aerosols (mean of ~80-88 min for male and female subjects for both aerosols). Small nonsignificant regional differences were observed. No differences between genders or between right and left lung were observed. 99mTc-DTPA/A generated the highest output of radioaerosol. 99mTc-DTPA with alcohol costs approximately five times more than the aerosol without alcohol. The present results show that either kind of aerosol may be adopted routinely for use in pulmonary examinations without affecting diagnosis. We suggest that the amount of 740 mBq (20 mCi) of 99mTc-DTPA in 1.5 ml saline can be used for routine examinations resulting in reduction of costs in pulmonary ventilation studies without diagnostic impairment.

Lindefemas dos membros inferiores: estudo linfocintilográfico / Lymphedema of the lower limbs: a lymphoscintigraphic approach

Pacientes con linfedema dos membros inferiores säo, geralmente, acometidos de erisipela recorrente. Essa infecçäo bacteriana costuma ser admitida como fator causal, mas poede ser consequüência de anomalia linfática prévia inaparente. Classicamente, admitem-se como causas mais comuns de linfedema dos membros inferiores as infecçöes bacterianas, úlceras de estase, trauma (que levam ao linfedema secundário) e as anomalias congênitas do sistema linfático (linfedemas primários - precoces ou tardios). OBJETIVO - Identificar anomalias linfáticas právias em pacientes com linfedemas supostamente secundários dos membros inferiores - conseqüentes a infecçöes, trauma ou outros fatores -, com o emprego da linfocitilografia. Observar as vantagens desse procedimento da prática assistencial e avaliar os casos de linfedemas do membros inferiores. MÉTODOS - Doze pacientes com diagnósticos clínicos preliminares de linfedema dos membros inferiores primário (congênito) ou secundário, atingindo um ou ambos os membros, foram submetidos à linfocintilografia, na Escola Paulista de Medicina, Säo Paulo. Cada paciente recebeu injeçäo intradérmica de dextran marcado (Dx99mTc) no primeiro espaço interdigital de cada um dos pés e, passadas uma a três horas, foram obtidas por gama-câmara (Gammatone CGR) imagem de extremidades inferiores, área pélvica e abdome. RESULTADOS - O exame clínico-dermatológico dos 24 membros inferiores permitiu diagnosticar linfedema em, 17 (70,8 por cento) deles, sendo cinco (41,6 por cento) com sinais de linfedema de ambas as extremidades e sete (58,3 por cento) com linfedema de um só membro inferior. O exame linfocintigráfico revelou anormalidades linfáticas em 22 dos 24 membros estudados (91,7 por cento). Anomalias linfocintigráficas foram dcetectadas em cinco casos de extremidades inferiores aparentemente normais, ao primeiro exame ambulatorial (41,3 por cento). CONCLUSAO - A linfocintilografia é método näo-invasivo útil para o estudo dos linfedemas dos membros inferiores cpm envolvimento uni ou bilateral. Näo permite diferenciar entre linfede-ma primário e secundário, mas torna possível a detecçäo de ca-sos de aparência normal do membro com defeito linfático prévio, modificando o diagnóstico etiológico do linfedema. Alguns casos que a princípio pareceram ser linfedemas secundários po-deriam ser, de fato, associados a anomalias linfáticas congênitas e desencadeados por fatores como trauma ou úlceras de estase venosa