Positive and negative interactions in the behavioural expression of D1 and D2 receptor stimulation in a model of Parkinsonism: role of priming.

Previous exposure to a dopaminergic agonist (priming) strongly potentiates contralateral turning behaviour in response to D1 and D2 agonists in unilaterally 6-hydroxydopamine-lesioned rats. In order to study the influence of priming on the behavioural interaction of D1 and D2 receptors, we examined the effect of selective D1 and D2 receptor blockade on the contralateral turning induced by the mixed D2/D2 agonist apomorphine in drug-naive and primed 6-hydroxydopamine-lesioned rats. In drug-naive rats, apomorphine induced a dose-related, apparently monophasic rotation curve. Administration of selective D1 (SCH 23390) or D2 (raclopride) antagonists abolished the contralateral turning induced by 0.1 mg/kg of apomorphine and partially inhibited that induced by 0.5 mg/kg. In primed rats low doses of apomorphine (0.05 mg/kg) induced an apparently monophasic contralateral turning which was reduced by D1 receptor blockade and completely abolished by D2 receptor blockade; a higher dose of apomorphine (0.1 mg/kg) instead elicited a biphasic (two-peak) pattern of rotation. After this dose of the agonist, blockade of D1 or D2 receptors abolished the second peak of rotation but, while D1 blockade reduced the total number of turns, D2 blockade failed to do so. Quantitative analysis of the interaction between D1 and D2 receptors in the overall turning effect, as well as in the time-course of turning behaviour, indicates that D1 and D2 receptors interact not only positively but also negatively. After higher doses of apomorphine, both negative and positive interactions take place sequentially during the time-course of apomorphine action and provide a clue for explaining the two-peak pattern of rotation observed after apomorphine in rats previously exposed to the drug.     

The dynamics of oral contraceptive use in the Netherlands 1990–1993

Data from an ongoing series of surveys on contraceptive use in the Netherlands were analyzed with respect to the percentages of oral contraceptive (OC) users who annually started use, discontinued use or switched to another OC type. The surveys had been conducted between 1990 and 1993 among samples of women aged 15–49 who belonged to a survey panel. Response rates of the surveys were 89–90% and the sample sizes ranged from 4560 to 4621 women. The assessed OC use rates reflected those of the Dutch population reasonably well. Of all respondents who had used OCs during the 12 months prior to the surveys, 12–15% discontinued use within this period, mainly in order to get pregnant, 12–16% were starters and 9–14% switchers. Of all starters 37% switched to another OC type within the first 12 months after starting. Switching was mainly related to the experience of perceived side-effects and wishes for better cycle control. The results highlighted the relevance of closely monitoring the individual woman's satisfaction with her OC. Since OC use appeared in many cases to be characterized by an active seeking for the most acceptable OC type, a wide range of OC types available and the development and introduction of new types is highly relevant for tailoring contraceptive use to individual needs.

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Resumen Se analizaron los datos de una serie de estudios que se están efectuando con respecto al uso de anticonceptivos en los Países Bajos a fin de determinar los porcentajes de usuarias de anticonceptivos orales (AO) que habían comenzado a utilizar, dejado de utilizar o pasado a otro tipo de AO, anualmente. Los estudios se habían efectuado entre 1990 y 1993 con muestras de mujeres de 15 a 49 años que formaban parte de un panel de estudio. Las tasas de respuesta de los estudios fueron del 89–90% y los tamaños de las muestras estuvieron comprendidos entre 4.560 y 4.621 mujeres. Las tasas de uso de AO evaluadas reflejaron las de la población holandesa razonablemente bien. De todas las encuestadas que habían utilizado AO durante los 12 meses anteriores a los estudios, el 12–15% dejó de utilizarlos dentro de este período, principalmente a fin de quedar embarazada, el 12–16% recién comenzaba a utilizarlos y el 9–14% había cambiado a otro tipo de AO. De todas las que recién comenzaban a utilizarlos, el 37% pasó a otro tipo de AO dentro de los 12 meses de iniciado su uso. El cambio se relacionaba principalmente con la experiencia de los efectos secundarios percibidos y el deseo de un mejor control del ciclo. Los resultados destacaron la importancia de una monitorización estrecha de la satisfacción individual de la usuaria con respecto a su AO. Dado que la utilización de AO pareció en muchos casos caracterizarse por la búsqueda activa del tipo más aceptable de AO, una amplia gama disponible de tipos de AO y el desarrollo y la introducción de nuevos tipos son aspectos que revisten gran importancia en la adaptación del uso de anticonceptivos a las necesidades individuales.

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Resumé Les données provenant d'une série en cours d'enquêtes sur l'utilisation des contraceptifs aux Pays-Bas ont été analysées du point de vue des pourcentages des utilisatrices de contraceptifs oraux (CO) qui ont, pendant chaque année, commencé à les utiliser, les ont abandonnés ou sont passées à un autre type de CO. Les enquêtes ont été menées entre 1990 et 1993 parmi des échantillons de femmes âgées de 15 à 49 ans qui constituaient la population étudiée. Les pourcentages de réponses aux enquêtes se sont élevés à 89–90% pour un échantillonnage allant de 4560 à 4621 femmes. Les pourcentages d'utilisation de CO évalués reflétaient assez bien ceux de la population néerlandaise en général. Parmi toutes ces femmes qui avaient utilisé les CO durant les 12 mois précédant l'enquête, 12–15% avaient cessé au cours de cette même période, en général pour avoir un enfant, 12–16% avaient commencé à les utiliser et 9–14% avaient changé de type de CO. Parmi toutes celles qui avaient commencé, 37% ont changé de produit au cours des 12 premiers mois. Le choix d'un autre type de CO étail essentiellement lié à des effets secondaires ressentis et au désir de mieux régler le cycle menstruel. Les résultats mettent en évidence combien il est important de suivre de près dans quelle mesure les femmes sont individuellement satisfaites du CO qu'elles adoptent. Etand donné que l'utilisation des Co semble, dans beaucoup ce cas, être caractérisée par une recherche active du type de CO le plus acceptable, le choix possible dans toute une gamme de CO, ainsi que la mise au point et l'introduction de nouveaux types, permettent remarquablement bien d'adapter l'utilisation des contraceptifs aux besoins individuels.

     

A clinical, microbiologic, and radiographic study of deep caries lesions after incomplete caries removal.

OBJECTIVE: Clinical, radiographic, and microbiologic changes in deep caries lesions were assessed after incomplete carious dentin removal and tooth sealing. METHOD AND MATERIALS: Thirty-two teeth with deep caries lesions were studied. Treatment consisted of incomplete excavation of the demineralized dentin, application of calcium hydroxide, and sealing for a 6- to 7-month period. The color and consistency of the dentin were clinically assessed. Differences in radiographic density were assessed by digital image subtraction. Microbiologic samples were obtained from the demineralized dentin before the temporary sealing and after the experimental period. The samples were cultivated on blood agar under aerobic and anaerobic conditions, in Mitis Salivarius agar, and Rogosa selective Lactobacillus agar. RESULTS: Two cases were lost during the study; one presented pulpal necrosis. In the other case, there was pulpal exposure during removal of provisional sealing. In all teeth, the initial demineralized dentin was soft and wet; one lesion was yellow, 21 were light brown, and eight were dark brown. After treatment, the dentin was dry, and 80.00% of specimens were hard, 16.67% were leathery, and 3.33% remained soft. The dentin was light brown in five teeth and dark brown in 25. There was a statistically significant mean difference in radiographic density (pixel intensity), 88.77 +/- 7.02 in the control areas and 94.66 +/- 6.75 in the test areas. The counts of anaerobic and aerobic bacteria, lactobacilli, and Streptococci mutans had decreased significantly by the end of treatment. CONCLUSION: Incomplete removal of carious dentin and subsequent tooth sealing resulted in the arrest of the lesions, suggesting that complete dentinal caries lesion removal is not essential to the control of caries lesions.     

Symptomatic reversible duodenal compression due to iatrogenic retroperitoneal hematoma

Selective serotonin reuptake inhibitors are frequently employed to treat depression. However, although rarely, coagulation abnormalities have been described following the use of these compounds, and these effects appear to be enhanced by simultaneous use of nonsteroidal anti-inflammatory drugs. We describe a case of reversible symptomatic duodenal compression caused by a retroperitoneal hematoma after ingestion of sertraline and nimesulide.     

Anesthesia and/or Sedation for Pulsed Dye Laser Therapy

One of the most exciting developments in pediatric dermatology has been the use of the flashlamp-pumped, 585-nm, pulsed dye laser for treatment of vascular birthmarks. In many cases the results are miraculous. The increase in self-esteem and happiness of many children and adolescents has been overwhelming; for some, depression has been lifted, stuttering has ceased, social involvement has increased, and antidepressants have been discontinued. There are many success stories to tell.
Despite the remarkable effects of the pulsed dye laser and the medical and psychosocial indications for its use, the issue of pain control remains significant. We have no perfect outpatient pediatric anesthetic. Most methods carry either some risk or, if not hazardous, often are not very effective for controlling pain. Needless to say, a diversity of opinions exist on how to manage discomfort from this treatment modality. Therefore, we thought it would be useful to share the experiences and opinions of several dermatologists who have extensive experience with the pulsed dye laser.