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Galvanic corrosion phenomena between the hull and the propeller of a ship induce static electric fields in sea water. These signatures can be observed on a vectorial electrical sensor and the authors investigate the design of a detection/localisation method based on the generalised maximum likelihood ratio test (GLRT). Incorporating a spatio-temporal analysis of the signals in the physical model, it is possible to partially estimate the trajectory of the target and to perform a detection decision. The resulting system consists in the calculation of the projection of the observation on a set of parameterised signatures and in selecting the projection that has the largest energy. An original method is proposed in order to determine the convenient partitioning of the set of projection bases. Due to the characteristics of the signals, classical results concerning performance analysis are not convenient and a specific framework is developed in order to analytically determine the behaviour of the system. A comparison with Monte Carlo simulations tends to prove the validity of the theory and the efficiency of the processing.

Previous studies have demonstrated that chronic treatment of C6 glioma cells with the antidepressants desipramine and fluoxetine increases the Triton X-100 solubility of the G protein Gsalpha (Toki et al., 1999). The antidepressants also caused a 50% decrease in the amount of Gsalpha localized to caveolae-enriched membrane domains. In this study, laser scanning confocal microscopy reveals that Gsalpha is localized to the plasma membrane as well as the cytosol in both treated and control cells. However, striking differences are seen in the distribution of Gsalpha in the long cellular processes after chronic treatment with these antidepressant drugs. Control cells display Gsalpha along the entire process with an especially high concentration of that G protein at the distal ends. Desipramine- or fluoxetine-treated cells show a more centralized clustering of Gsalpha in the Golgi region of the cell and a drastic reduction of Gsalpha in the cellular processes. There is no change in the distribution of Goalpha after desipramine treatment and the antipsychotic drug chlorpromazine does not alter Gsalpha. These results suggest that antidepressant-induced changes in the association of Gsalpha with the plasma membrane may translate into altered cellular localization of this signal transducing protein. Thus, modification of the coupling between Gs-coupled receptors and adenylyl cyclase may underlie both antidepressant therapy and depressive illnesses. This report also suggests that modification of the membrane domain occupied by Gsalpha might represent a mechanism for chronic antidepressant effects.

18 subjects with symptomless HIV infection were investigated with multimodal evoked potentials for possible CNS involvement and again after an 8–12 month interval. 13 subjects showed neuropsychological changes, which were confirmed at the second examination. The 5 subjects found normal remained so at the second examination. On WAIS assessment the only patient to earn pathological scores was the one with the greatest evoked potentials changes. Thus the evoked potentials procedure proved capable of identifying early CNS involvement by HIV infection.

Multimodality evoked potentials (somatosensory and acoustic) have been recorded before surgery in children selected for surgical treatment for different kinds of craniostenosis and craniofacial stenosis. Evoked potentials were found to be deranged on at least one recording in 50 of cases, suggesting a significant incidence of neurophysiological alterations in these patients. No correlation was found between evoked potentials' derangements and clinical status, radiological findings, or different kinds of craniostenosis; moreover, a significant correlation was found between neurophysiological alterations and the age of the children. These preliminary data might define the possible role of neurophysiological tests-in the presurgical-evaluation of craniostenosis and craniofacial stenosis.

Summary Since 1988 in the referral area of the Neurosurgical Unit of Cesena, Italy, a protocol for prevention of deterioration in minor head injury was adopted. Adult patients admitted to any hospital with a GCS score of 15 and 14 (transient) without neurological deficit are submitted to skull x-ray: if a fracture is present the patient is sent for CT to the nearest regional Center. In children skull x-ray is not routinely performed and the patients are admitted for observation to the nearest regional hospital.

The radioprotective compounds studied do not alter the wound healing pattern in the nonirradiated rat when wounding follows drug administration by 4 days. These compounds also do not demonstrate any deleterious interaction with wounding under these circumstances. The radioprotective compounds studied promoted the wound healing pattern of irradiated, wounded rats toward the pattern of nonirradiated wounded rats. The increased mortality observed with the combination of a nonlethal surgical wound and radiation was not observed in animals treated prior to radiation with the radioprotective agents studied (MEA, serotonin, and WR 2721-C).

The purpose of this study was to clarify the role which disordered iron metabolism and alterations in the homeostatic regulation of red cell production play in hypothyroid anemia. Following the measurement of the oxygen consumption, rats were thyroidectomized and given an ablative dose of sodium 131iodine. The oxygen consumption was again measured and the experiments initiated 8 weeks thereafter. The 18-hr red cell radioiron incorporation was used as an index of erythropoiesis. The gastrointestinal absorption of radioiron and the 24-hr urinary erythropoietin levels were assessed. Hypothyroid rats demonstrated a decreased red cell radioiron incorporation and a diminished GI iron absorption. The diminution in erythropoiesis was reverted toward normal by the administration of erythropoietin, D-triiodo-thyronine, L-triiodothyronine or exposure to hypobarbaric hypoxia. Erythropoietin, which completely corrected the erythropoietic depression in the hypothyroid rats, did not correct the decreased GI radioiron absorption whereas L-triiodothyronine restored both to normal. Urinary erythropoietin was decreased in the hypothyroid rat and reverted to normal following L-triiodothyronine administration. These data suggest that the mechanism producing the erythropoietic decompensation in hypothyroid states is complex and involves the lack of erythropoietic stimulation by erythropoietin. Acute erythropoietic compensation appears possible by the administration of nonspecific erythropoietic stimulants; however, the defect in gastrointestinal iron absorption can only be repaired by the administration of thyroid hormones.

Exposure to a 50% oxygen environment produced a decrease in erythropoiesis which was paralleled by a decrease in plasma erythropoietic stimulating activity. Similar results were obtained following exposure to a 100% oxygen environment. Marrow depression produced by hyperoxia could be reversed by erythropoietic stimulants. The suppression of erythropoiesis in both partners of parabiots maintained so that one breathed 20% and the other 90-95% oxygen suggests that a humoral inhibitor is produced in the hyperoxic animal and supports the hypothesis that erythropoiesis is regulated by the dynamic interaction of erythropoietin and an erythropoietic inhibitor.

Iron metabolism was studied in acutely starved and erythropoietically stimulated rats. Acute starvation did not alter blood volume or gastrointestinal absorption of radioiron. However, prolongation of the plasma iron clearance with concomitant diminution in plasma iron turnover and radioiron in the bone marrow was demonstrated in starved animals. These results can be explained by diminished erythropoiesis. Eryth-ropoietin administration reversed these changes, augmenting plasma iron turnover, gastrointestinal absorption of radioiron and bone marrow radioiron content. Approximately equal increases in plasma iron turnover were produced in both the fed and starved animal by injection of equal amounts of erythropoietin.

The intestinal absorption of radioiron was determined following X-irradiation of the exteriorized small intestine in the rat. The morphologic lesion resulting was discontinuous, with areas of intestinal radiation injury alternating with areas which were essentially intact or hypertrophic. The results indicate that there was an increase in radioiron absorption following irradiation and suggest that this increase was due to augmented absorption in those areas of the small intestine which did not develop the morphologic characteristics of severe radiation injury. Possible mechanisms are discussed.

Among 62 children and adolescents (1–16 years) admitted over a period of 3 years (1987–1989) with a minor head injury, 33 (53%) were found to harbour intracranial lesions of surgical interest. The most frequent lesion found was extradural haematoma (17 cases), followed by cerebral contusion (7 cases), depressed fracture (4 cases), depressed fracture with underlying contusion (3 cases) and pneumocephalus (2 cases). A skull fracture was present in 88% of patients with an intracranial lesion and in 50% of patients without lesions. Fifteen patients underwent surgery for an extradural haematoma or a depressed fracture. All had a good recovery. No correlation was found between age and Glasgow Coma Score on the one hand, and the incidence of both the presence of intracranial lesions and the necessity of surgical treatment on the other. The only important risk factor proved to be a skull fracture, which had occurred significantly more often in patients with intracranial lesions than in those without any.

Erythropoietic decompensation in renal failure has been attributed to diminished production of erythropoietin(1,2) or decreased marrow sensitivity(3,4) to this substance. The relative significance of diminished stimulation or marrow inhibition remains unknown. In the present experiments erythropoiesis and responsiveness to erythropoietic stimulation were assessed in rats made acutely uremic by bilateral nephrectomy. In addition, the effect of uremic plasma on in vitroreticulocyte iron incorporation was studied. The results suggest that red cell production diminished in part because sensitivity to erythropoietin was decreased. In vitroincorporation of radioiron by reticulocytes was not depressed by the uremic milieu.Materials and methods.Female Sprague-Dawley rats weighing 200–300 g were maintained on a regular laboratory animal diet†and provided water ad libitum. Erythropoiesis was assessed in normal rats and in nephrectomized rats 48 or 72 hours following removal of the kidneys. Similar assessments were undertaken in normal rats and nephrectomized rats stimulated by injection of exogenous erythropoietin.The stimulated nephrectomized rats were given injections of active extract of anemic rabbit plasma(5) one, 18, and 24 hours following nephrectomy. Non-operated controls were stimulated in an identical manner and measurements of erythropoiesis were made in both groups at 72 hours. Erythropoiesis was assessed by: determination of microhematocrits, enumeration of reticulocytes(6) and measurement of erythrocyte incorporation of radioiron 24 hours after intravenous injection of 1 μc Fe59/1 μg Fe56citrate(5). Radioiron partition in the spleen, liver and bone marrow(7) was also determined. Urea nitrogen content was determined on pooled plasma samples from each group(8).Additional experiments tested the effect of uremic plasma on in vitroiron incorporation by reticulocytes. Reticulocytosis was produced by serial bleedings each approximating 20% of the rats’ blood volume. One week following the initial bleeding, the rats were exsanguinated.

Serial observations were made on plasma erythropoietin levels of infants during the first 90 days of life. Results indicate variable erythropoietin titers and are suggestive of a physiologic control of erythro-poiesis during the newborn period by erythro-poietin.

Both dextro-triiodothyronine and levo-triiodothyronine produced similar increases in RBC 59Fe incorporation in polycy-themic rats when the increased red blood cell mass would have been expected to obviate the response to oxygen need. Single doses of 25; 100 or 250 μg LT3and DT3produced similar increases in RBC 59Fe incorporation in normal rats. The RBC 59Fe incorporation was minimally increased at 24 hours and continued to increase 48 and 72 hours following a single dose of LT3or DT3. Plasma obtained from rats following administration of LT3or DT3failed to demonstrate erythropoietic activity on bioassay in the plethoric mouse, suggesting that increased erythropoietin production is not the mechanism for the augmented erythropoiesis.

LT3administration produced an increase in erythrocyte radioiron incorporation in rats. This response was not modified by administration of reserpine. Animals given LT3or DT3showed comparable increases in erythrocyte radioiron incorporation, however rats given LT3demonstrated a marked increase in oxygen utilization when compared to DT3treated rats.

The tissue iron levels and tissue distribution of an intravenous dose of radioiron were studied in germfree and conventionalized mice. The germfree animals demonstrated similar plasma iron levels, diminished plasma radioiron clearance rate, diminished iron concentration in the liver and spleen, a slower rate of accumulation of radioiron in the liver and spleen, and no difference in the percentage of radioiron found in the red blood cell at 18 hr when compared to conventionalized mice.

The determination of urinary electrolytes is helpful in the diagnosis of children with dyselectrolytemia or metabolic acid-base imbalance of unknown origin [1–3]. The urinary excretion of electrolytes has mostly been evaluated by investigating 24-hour urine specimens [4]. The collection of such urine samples is laborious in children without bladder control, in those unable to comply while playing or at school, or in those with acute electrolyte abnormalities. The usefulness of measuring urinary solutes in relation to creatinine in urine has been suggested [5].