Radionuclide tracing of water masses and processes in the water column and sediment in the Algerian Basin.

Caesium-137 and (239,240)PU were analysed in the water column along the Algerian coast. The (137)Cs activity concentration in surface water increased from the west to the east from 1.6 to 3.3 mBq L(-1), documenting a presence of Modified Atlantic Water (MAW) in the region. Higher concentrations observed in deep waters may be due to an intrusion of Levantine Intermediate Water (LIW), which has been carrying higher levels of (137)Cs from Chernobyl accident. The (239,240)Pu sub-surface concentration peaked at about 250 m water depth as a result of biogeochemical processes in the water column. The observed (239,240)Pu/(137)Cs activity ratio at the surface (0.003) was significantly lower than that in global fallout (0.04). This decrease exceeds that expected from radioactive decay of (137)Cs, and confirms that Pu due to its adsorption on sinking particles is more effectively removed from surface layers than is (137)Cs. An increase of the (239,240)Pu/(137)Cs activity ratio with depth suggests that (239,240)Pu, similarly as (137)Cs, should be also transported by advection to maintain the observed ratios in deep waters. An intrusion of LIW may enhance therefore both the (137)Cs and (239,240)Pu concentrations in deep waters. The average (238)Pu/(239+240)Pu activity ratio in seawater was 0.03+/-0.02, confirming a global fallout origin of Pu in the Algerian Basin. Caesium-137 and (239,240)Pu inventories in the water column were estimated to be from 2.7+/-0.5 kBq m(-2) to 3.8+/-0.7 kBq m(-2), and from 13.8+/-2.6 Bq m(-2) to 41+/-7B qm(-2), respectively. The (137)Cs massic activities in surface sediment were almost constant, the average activity was 9.0+/-0.8 Bq kg(-1). Sedimentation rates obtained using the (210)Pb method were from 0.1 to 0.7 cm y(-1), and resulting penetration depths of (137)Cs in the sediment cores were from 15 to over 40 cm. The (137)Cs peaks found in the sediment cores were associated with the Chernobyl accident (1986) and global fallout (1964). The (137)Cs inventories in the sediment were increasing from the west (180 Bq m(-2)) to the east (350 Bq m(-2)).

[Results of the surgical treatment of Basedow's disease. Apropos of 30 cases]. / Résultats du traitement chirurgical de la maladie de Basedow. A propos de 30 cas.

Thyroid function was evaluated after thyroidectomy in 30 cases of Graves' disease. 15 patients were euthyroid, 6 of them were TRH non responsive suggesting a risk of relapse. Indeed, the 3 proven cases of relapse were TRH non responsive before relapse and remained so after treatment. The severe iodine deficiency in Algeria did not seem to increase the frequency of post-operative hypothyroidism. Neither did the duration of carbimazole therapy, the severity of thyroid lymphocytic infiltration or thyroid antibodies titer. Thyroid remnant size, although difficult to estimate, appears to be inversely related to post-operative TSH values.

Comparative study of neurological and myxoedematous cretinism associated with severe iodine deficiency.

The clinical and biochemical features of myxoedematous and neurological cretinism were studied in an endemic goitre area in Algeria (goitre prevalence 51.3%; endemic cretinism 1.1%; mean urinary iodine level 127.6 nmol/l). When comparing the data collected in six different villages of the area, significant negative correlations were found between the decrease in urinary iodide and iodide/thiocyanate ratio (I/SCN) and the increase in prevalences of visible goitres, endemic cretinism and transient neonatal hypothyroidism. The cretins were divided on clinical signs into two groups: myxoedematous (MC) and neurological (NC) cretinism. Differences were noted in the neurological signs and the type of deafness encountered in both types. Although some overlap did exist, proximal spasticity and rigidity were characteristic of NC. The hormonal profiles of the two groups, including TRH tests, were clearly different. The two groups were similar with regard to the percentage of palpable thyroids, the absence of antimicrosomal and anti-thyroglobulin antibodies, seropositive viral antibodies and thiocyanate concentrations in serum and urine. Thus it is unlikely that these factors have any significant aetiological role in NC. The data collected in the general population in this area and those obtained in the mothers of the myxoedematous and neurological cretins support the hypothesis that the neurological signs are the result of hypothyroxinaemia in the mothers and the fetus at different periods of pregnancy. They could be aggravated by neonatal hypothyroidism, which may be transient in NC and permanent in MC.

The sella turcica in Sheehan's syndrome: computerized tomographic study in 54 patients.

A CT scan study of the sella turcica and its contents was conducted in patients with Sheehan's syndrome with a search for correlation between the radiological data and the degree of endocrine insufficiency on one hand, and the time course of the disease on the other. Fifty-four patients with Sheehan's syndrome were included: 32 with complete anterior hypopituitarism, 22 with at least one spared pituitary function. Subgroups of equal size were obtained with a cut-off of 9 years evolution. The CT scan appearance of the pituitary was never normal in Sheehan's syndrome. The sella turcica was totally empty in 39 patients. A pituitary remnant was visible in 15 patients, more frequently in those with incomplete hypopituitarism (p less than 0.005) and those with short evolution (p less than 0.025). The size of this pituitary residue never exceeded one third of the normal pituitary gland. The pituitary stalk was always visualized. On the other hand, the size of the fossa was significantly (p less than 0.001) smaller in the patients, as compared to a 12-female control group, matched for age and number of pregnancies. Among the patients there was no difference when considering the disease duration nor the degree of hypopituitarism. An empty or partially empty sella of normal or reduced size is a constant feature of Sheehan's syndrome. The presence of a pituitary remnant is inversely correlated to the duration and extension of the disease. Arachnoid herniation alone does not induce a dilatation of the fossa.

[Thyrotropic reserve in Sheehan's syndrome. Study in 36 patients (author's transl)]. / La réserve thyréotrope au cours syndrome de Sheehan. Etude chez 36 malades.

Thyrotropic involvement is considered to be constant in Sheehan's syndrome. In this study, plasma thyroid stimulating hormone (TSH) levels were similar to those of normal women (respectively: 1.01 +/- 0.54 ng/ml and 0.54 +/- 0.27 ng/ml). The pituitary response to the administration of TRH was nul in 63.8% of cases. In one patient, thyrotrophic function was normal. Twelve patients had a minimal or moderate reserve of TRH. By order of prevalence, thyrotrophic involvement succeeds that of the somatotrophic and lactotrophic axes. There is no correlation with involvement of other axes which would make it possible to define a sequential course of pituitary lesions. These results are discussed in the light of the existing literature. The TRH test does not offer certain evidence of hypothalamic involvement.