Aneurysmal cysts located in the maxilla or mandible (author's transl)]

Aneurysmal cysts of the mandible and maxilla are rare conditions, though not exceptional, which are seen in particular in the child and adolescent. A part from facial asymmetry and tumefaction, it is rare to find other clinical manifestations. No neurological signs were seen in the present study. An aneurysmal cyst gives a radiological appearance of non-characteristic lysis compatible with a large range of diagnoses. Histological study permits early diagnosis but must always involve the whole specimen with careful examination to detect any other associated lesion. The pathogenesis of the condition remains obscure and, at the extreme, it may be questioned whether the aneurysmal cyst is a separate entity or a particular form of chronic osteopathy.     

Functional treatment of acromegaly by transsphenoidal microsurgery

The authors have analyzed the results from 41 acromegalic patients who underwent transsphenoidal surgery. In 31 patients, postoperative growth hormone (GH) levels fell and remained below 10 ng/ml. This represents an endocrinological "cure" of 78%. In the remaining 10 cases, postoperative GH values have not stabilized below 10 ng/ml, although seven show some clinical improvement. The results were particularly good in those cases of localized adenomas, which allowed a selective removal while maintaining pituitary function within normal limits in 65.5% of cases. The postoperative GH level in this group fell and remained below 10 ng/ml in more than 90% of cases. Four patients required reoperation to normalize the GH levels which had not been sufficiently modified after the first operation; only one of them remained with plasma GH levels above normal limits. There were no deaths in this series. Rhinorrhea occurred as a postsurgical complication in four cases. In three this disappeared with bed rest and lumbar drainage; in the other, surgical repair was necessary. The occurrence of surgical complications has decreased as our experience has increased, and the need for reoperation has been unusual after the first year of our study.     

Freeze-fracture study of melanosomes in mammalian epidermis and the distribution of intramembrane particles in the melanosome membrane

Summary The ultrastructure of melanosomes in mammalian epidermis has been studied using the freeze-fracture technique. The internal structure of the melanosome, as seen in cross-fractured granules, consists of a very fine particulate matter. There is no evidence of an internal membranous structure in melanosomes, indicating that the internal matrix which is characteristic of ultrathin sectioned material most likely represents cross-linked protein fibers.Fracture en-face of the melanosome limiting membrane reveals a random distribution of intramembrane particles on both the P- and E-faces of the membrane. There is a significantly higher density of IMPs on the P-face. The IMPs of the melanosome membrane may be involved in (a) selective passage of ions through the membrane, (b) membrane transducing events, and/or (c) anchoring sites for cytoplasmic fibrils and microfilaments.Research supported by USPHS Grant AM-20669 from the National Institute of Arthritis, Metabolism, and Digestive Diseases     

Influence of acid-base alterations on myocardial sensitivity to catecholamines

Summary The influence of respiratory and metabolic acid-base alterations on the myocardial sensitivity to catecholamines was studied in the isolated rat atria. The ability of noradrenaline for increasing the atrial rate was enhanced during alkalosis and conversely, it was decreased by acidosis. These changes in sensitivity shifted the concentration-effect curve for noradrenaline to the right by about 0.5 log unit when the pH was lowered from 7.60 to 7.00. No changes in the maximum attainable response were detected. Essentially the same shifts of the concentration-effect curves were obtained with changes in pH brought about by altering the pCO₂ or at constant pCO₂. The decrease in the pH produced a similar shift to the right of the concentration-effect curve for isoprenaline, after the extraneuronal uptake inhibition by hydrocortisone and also in atria tissue with low content of endogenous noradrenaline (reserpine-pretreated and newborn rats). The ability of isoprenaline for increasing cyclic AMP levels in atrial tissue was also enhanced by alkalosis and decreased by acidosis. However, the shift to the right of the concentration-effect curve for cyclic AMP induced by the decrease in the pH was greater than the shift detected in the chronotropic-effect curve. In addition a decrease in the maximum increment of cyclic AMP was detected under acidosis, in spite of equal maximal chronotropic response.Our results support the hypothesis that the alterations in the sensitivity to catecholamines induced by the changes in pH are not due to a release of endogenous noradrenaline nor to alterations of the mechanisms which remove catecholamines from the biophase. The fact that cyclic AMP response to catecholamines was also reduced by acidosis strongly suggests that the mechanism(s) involved is located in the earlier steps of the events leading to the chronotropic effect of the -agonists.     

Leucoéncephalopathie multifocale progressive

Summary A young woman presented a mixed congenital and familial immunodeficiency syndrome consisting in an absence of IgA and lowered levels of IgG and IgM, with a defect in cellular immunity. She had a mild malabsorption syndrome with slight alterations of the jejunal mucosa. Non-caseating tuberculoid granulomata were found in skin lesions, in lymph nodes and in the spleen. At age 27 the patient died of a neurological disease of 4 months duration. Autopsy revealed a very widespread demyelinating process involving mainly the right cerebellar hemisphere but also most of the pons and left cerebellum, with the typical morphologic characters of PML. In the hemispheres lesions were limited to microscopical microglial nodules with discrete demyelination. A review of 86 published cases of PML revealed 9 other cases in which lesions showed a strong predilection for the subtentorial territories. This sampling allows for the assumption that some 11% of the cases of PML have this particular lesion distribution. Other pertinent features of this case are briefly discussed.

     

Electrophysiological determination of the refractive state of the eye of the opossum

The refractive state of the eye of the South American opossum Didelphis marsupialis aurita was investigated with electrophysiological techniques. Using adult specimens, trapped from the wild, averaged cortical evoked responses were recorded from the region of projection of the central visual field. Stimuli consisted of a phase reversal of a square wave grating generated on a CRO screen, with luminance of 2.4 cd/m2 and contrast 0.84. The refractive state of the eye was altered by means of trial lenses and the amplitude of the cortical responses thus obtained compared to those obtained with no lens (control values). Refraction "tuning curves" were determined for each animal. The average refractive state was found to be -2.27 D indicating that this species when raised in its habitat shows, at low ambient luminosity, some degree of myopia. Determination of the Contrast Sensitivity Function indicate that induced ametropias lead to a reduction of the cut-off value of the spatial frequency and a loss of contrast sensitivity.     

Effect of prenatal and postnatal exposure to therapeutic doses of chlorimipramine on emotionality in the rat

Prenatal administration of high doses of tricyclic antidepressants have been reported to produce teratogenic and behavioral effects in rat offspring. In the present work, behavioral abnormalities are described in offspring of rats treated with therapeutic doses of chlorimipramine (CIM) during pregnancy (CIM-P), lactation (CIM-L) and during the whole pregnancy-lactation period (CIM-PL). CIM-P treatment did not produce teratogenic effects, did not affect number or body weight of pups at birth and did not induce neonatal mortality. At 2 months of age, the CIM-P males showed a significant increase in digging and grooming (familiar environment test), a decrease in exploration (novel environment test) and a decrease in active social interactions (social behavior test). Females were more resistant than males to the prenatal CIM treatment. The results suggest increased emotionality in CIM-P pups. Some behavioral abnormalities were also observed in the tests performed at 4 months of age. CIM-L treatment had minor effects on litter behavior. CIM-PL treatment potentiated the effects of the CIM-P treatment. In the CIM-PL males, impairment of exploration of a novel environment still remained in the tests performed at 4 months of age. It is speculated that when prenatal brain development is altered by CIM, further postnatal treatment may impair compensatory processes occurring in early postnatal life.     

Effects of tianeptine on spontaneous alternation, simple and concurrent spatial discrimination learning and on alcohol-induced alternation deficits in mice

The effects of systemic administration of tianeptine, a new psychotropic agent with antidepressant properties, were investigated on spontaneous alternation behavior, and on simple and concurrent spatial discrimination, in normal mice of the BALB/c strain. Tianeptine increased rates of spontaneous T-maze alternation, facilitated retention of a T-maze left-right discrimination, and speeded up acquisition of concurrent discrimination in a radial maze. These effects were consistent across successive experiments with a dose of 10mg/kg; lower doses (2.5 and 5.0mg/kg) had less or no effect depending on the task. These results, together with theoretical considerations, led us to investigate the effect of tianeptine on the sequential-specific alternation deficit induced by long-term ethanol administration in the same strain of mice. Results showed that, at the dose of 10mg/kg, the drug completely alleviated the alcohol-induced deficit. Unlike tianeptine, fluoxetine impaired discrimination performance in the radial maze. These data are discussed in light of the effects of tianeptine on serotonergic transmission and of the role of serotonin and acetylcholine in learning and memory processes.     

Blood pressure, physical activity and anthropometry in adolescents]

The relationship of blood pressure with physical activity and anthropometry was studied in 295 adolescents (mean age, 15.3 years) who entered 1. "formación profesional" (a technological training) in 1990 in Puerto Real, a village of Cádiz, Spain. Systolic and diastolic (fifth-phase Korotkoff) blood pressure, and anthropometrics measurements (weight, height and triceps and subscapular skinfolds thickness) were measured with standardized techniques. Habitual and sports physical activity were assessed by a self-reported questionnaire. The results reported in this study suggest that systolic blood pressure is associated with habitual physical activity in girls, and that the systolic blood pressure is associated weakly with sports activity in girls and in boys. The stronger predictor of blood pressure was Quetelet Index (kg/m2).     

Derivates of 1,1-dioxo-1,4,2-benzoditiazines. Part XII. Synthesis and pharmacology of some 6-chloro-3-carboxyalkylamino-7-methyl-1,1-dioxo-1,4,2-benzodithiazines

Preparation of some novel 6-chloro-3-carboxyalkylamino-7-methyl-1,1-dioxo-1,4,2-benzodithiazines (I-V) and its sodium salts (Ia, IVa) have been elaborated. Their chemical structures have been confirmed by elemental analysis, IR and 1H-NMR spectrometry. In preliminary pharmacological examination compounds I, Ia, IV and IVa exhibited low acute toxicity, moreover investigated compounds shown hypertensive and cholagogic activity (I, Ia) and also hypotensive (IV, IVa) or diuretic (Ia, IVa) activity, on the other hand above mentioned compounds didn't exhibit antiarrhythmic activity. Some relationships between the chemical structure and pharmacological activity of the investigated compounds have also been discussed.