[Glucose tolerance of high-dose intravenous methylprednisolone therapy in ophthalmology]. / Tolérance glycémique des bolus intraveineux de méthylprednisolone en milieu ophtalmologique.

INTRODUCTION: Short-term, high-dose intravenous methylprednisolone therapy, also called pulse methylprednisolone, is widely used in a variety of inflammatory eye diseases. Monitoring blood glucose during this therapy is recommended. We evaluated the clinical implications of glycemia monitoring during repeated pulse methylprednisolone for eye disease. PATIENTS AND METHODS: During the year 2000, 224 patients received 120-1 000 mg daily intravenous methylprednisolone for 3 consecutive days for acute optic neuritis (n=91), severe uveitis (n=35), ocular infectious diseases (n=22), corneal graft rejection (n=17) and miscellaneous disorders (n=59). Serial morning fasting blood glucose, i.e., before the first pulse and the day after each pulse, and specific hypoglycemic drug interventions were recorded. RESULTS: All patients showed a median 50% increase in fasting glucose after the first pulse with no significant difference between diabetic and nondiabetic patients. Thereafter, the 196 nondiabetic patients showed a spontaneous decrease in their fasting glucose towards baseline values despite the following infusions. However, none of them required hypoglycemic intervention. In contrast, the 28 diabetic patients demonstrated further increases in blood glucose levels and seven received rapid-release treatment. CONCLUSION: Glucose tolerance of pulse methylprednisolone was excellent in nondiabetic patients; close glycemia monitoring seems necessary only for patients with diabetes.

[Thyroid orbital pathologies in ophthalmological settings]. / Orbitopathies thyroïdiennes en milieu ophtalmologique.

OBJECTIVE: To illustrate the originality and diversity of an ophthalmologic pathology associated with a thyroid disease (OATD), we report 42 cases of patients hospitalised or having consulted an ophthalmologic department for this disease over a period of 4 years. METHOD: Each patient was assessed by an endocrinologist and an ophthalmologist. Data included the OATD severity score, date of occurrence compared with the thyroid disease and determination of thyroid function and immune abnormalities. RESULTS: Patients were aged a mean of 48.9 + 15.3 years; 65% were women and 39% smokers. OATD preceded the thyroid disease in 38% of cases, was concomitant in 40% and successive in 21%. Thirty-six percent of cases were mild, 45% moderate and 19% were severe. One patient out of 5 had exhibited a period of iatrogenic hypothyroidia. The majority (81%) presented with Basedow's disease; 14% Hashimoto's disease; 73% anti-TSH receptor antibodies and 56% anti-thyroperoxidase antibodies. Two profiles of patients with OAMT were identified. A first group with severe OATD: Basedow's disease, presence of anti-TSH receptor antibodies and a period of iatrogenic hypothyroidia in half of the cases. A second group in which the occurrence of OATD preceded diagnosis of a thyroid disease: generally non-severe forms with varying thyroid status, strongly related to the moment at which the patient consulted, compared with the progression of the ophthalmologic and thyroid affections. CONCLUSION: When faced with signs evoking OATD, these data emphasize the need for an evaluation of thyroid status and determination of the antibodies implied in Basedow and Hashimoto's disease. After initiation of synthetic anti-thyroid or radioactive iodine therapy, the evolution of the thyroid and ophthalmologic status of hyperthyroid patients must be carefully monitored.

Pentagastrin testing in patients with renal insufficiency: normal responsivity of mature calcitonin.

Calcitonin (CT) is the most sensitive tumor marker for medullary thyroid carcinoma available, but it lacks specificity. Chronic renal failure (CRF) is known to be associated with elevations of serum immunoreactive calcitonin. Using an immunoradiometric assay to detect only mature CT, we evaluated the basal CT level and its response to pentagastrin in 30 patients with CRF and compared these data with those obtained in 71 controls. Basal mature CT was significantly higher (p < 0.05) in patients with CRF (3.55 pg/mL) than in controls (2.00). Among these patients, 20% had basal CT levels more than 10 pg/mL with a maximum of 51 pg/mL. Peak CT values (highest value obtained 3 or 5 minutes after pentagastrin) were comparable in the two groups. Among patients with CRF, 10% had peak CT values greater than 30 pg/mL with a maximum of 53 pg/mL. In this group of patients, no correlation was found between CT (at any time during the test) and parathyroid hormone, calcium, phosphate, or creatinine clearance. Men had significantly higher CT values compared with women at each time point tested, including peak values. Patients with CRF, who have not yet undergone dialysis, have moderately elevated basal CT levels, but have normal pentagastrin-stimulated peak CT levels.

Highly sensitive dynamic strain measurements by locking lasers to fiber Bragg gratings.

A novel, sensitive, simple, and robust strain interrogation technique is analyzed and experimentally tested. By locking a laser wavelength to the midreflection wavelength of a standard fiber Bragg grating and measuring the error signal, we achieve high dynamic strain sensitivity of 45 picostrain/ radicalHz rms at 3 kHz, where the dominant noise in the experiment is the laser frequency noise.

Relationship of antibodies to thyrotropin receptors and to thyroid ultrasonographic volume in euthyroid and hypothyroid patients with autoimmune thyroiditis.

It has been reported in hypothyroid patients with Hashimoto's thyroiditis and in patients with primary myxoedema that antibodies (Ab) to the TSH-receptor (R), which inhibit the thyroid gland, decrease both thyroid hormonogenesis and cell growth in vitro. We investigated, in 169 newly diagnosed patients with euthyroid (n = 83) or hypothyroid (n = 86) autoimmune thyroiditis, the relationship between thyroid autoimmunity expression and thyroid ultrasonographic volume or thyroid hormonal status. In patients positive for TSH-receptor (R) antibodies (Ab), negative correlations (P < 0.01) were found between TSH-R Ab levels and free T4 (FT4) values in a euthyroid (r = -0.63), as well as in a hypothyroid (r = -0.54) state, and between TSH-R Ab and total thyroid volume (TTV) values in an euthyroid (r = -0.62) as well as in a hypothyroid (r = -0.53) state. In contrast, no positive correlations were found between TSH levels and FT4 values or TTV levels in patients positive as well as negative for TSH-R Ab in an euthyroid or in a hypothyroid state. These data demonstrate in vivo, that, in contrast to TSH, TSH-R Abs are related to both thyroid hormonal production and volume in euthyroid or hypothyroid patients with autoimmune thyroiditis.

Solitary skin metastasis as the presenting feature of differentiated thyroid microcarcinoma: report of two cases.

Cutaneous metastases from thyroid neoplasia are very rare. Most patients presenting with such a disease have also both internal metastases and a very enlarged thyroid gland. We reported here 2 patients presenting with differentiated thyroid microcarcinoma which was revealed by a solitary scalp lesion. The positive immunoperoxidase staining for thyroglobulin (TG) in the skin tumour cells asserted the diagnosis of metastatic thyroid carcinoma. The thyroid neoplastic micronodular formation was unrecognized by ultrasonography and it was only found at serial histological examination of the thyroid gland entirely removed during surgery. Histological procedure showed a solitary follicular microcarcinoma (diameter = 0.5 cm) in 1 patient, and two differentiated microcarcinoma, a follicular microcarcinoma (diameter = 0.4 cm) in a lobe and a follicular-papillary carcinoma (diameter = 0.5 cm) in the other lobe, in the second patient.

Prevalence of sporadic medullary thyroid carcinoma: the importance of routine measurement of serum calcitonin in the diagnostic evaluation of thyroid nodules.

OBJECTIVE: The prevalence of sporadic forms of medullary thyroid carcinoma (MTC) has been studied in patients living in an area of moderate iodine deficiency. Such forms of MTC are usually diagnosed after surgery and have little chance of definitive cure. Using the measurement of basal serum calcitonin (CT) levels in a large series of patients with both thyroid disease and normal 24-hour urinary iodine excretion, we assessed the prevalence of MTC and, in patients affected with the disease, we also evaluated the stage of the disease according to surgical findings and post surgical plasma CT levels. PATIENTS: A prospective study of 657 patients with thyroid disease (469 with nodular and 188 with non-nodular thyroid disease). As controls, 40 normal subjects were also studied. MEASUREMENTS: In all patients: (1) measurement of basal serum CT, free T4, total T3, TSH levels and serum TSH-receptor, peroxidase and thyroglobulin (Tg) antibody concentrations, (2) thyroid ultrasonography, (3) fine needle aspiration cytology (FNAC). In patients with increased basal CT levels: (1) measurement of serum CT levels during pentagastrin test prior to surgery, (2) histological examination and immunostaining with both anti-CT and anti-Tg antibodies of all the nodular thyroid tissue surgically removed, (3) measurement of basal and pentagastrin stimulated serum CT values after surgery. RESULTS: All the patients with non-nodular thyroid disease had normal basal CT levels. Four patients (0.84%) with nodular thyroid disease (2 with uninodular and 2 with multinodular goitre) had both elevated basal and pentagastrin stimulated CT levels. In the two patients with uninodular goitre, FNAC was suggestive of MTC in 1 (nodular diameter 8.0 cm) and of follicular carcinoma in 1 (nodular diameter 2.5 cm). Histological examination of the nodules confirmed these histotypes. Immunostaining with anti-CT antibodies was positive in the former patient but also in the latter. FNAC was suggestive of benign adenomatous tissues in the two patients with multinodular goitre. Histological examination of all the thyroid nodules confirmed the cytological findings. However, serial sections through the gland in each of these two patients showed an occult follicular carcinoma which had, however, positive staining with anti-CT antibodies. Furthermore, immunostaining with anti-Tg antibodies was negative in the patient with MTC but positive in the 3 patients with follicular carcinoma. Finally, both basal and pentagastrin stimulated CT levels remained elevated after total thyroidectomy only in the patient with FNAC suggesting MTC. CONCLUSIONS: This study demonstrates a surprisingly high prevalence of sporadic forms of medullary thyroid carcinoma in patients with nodular thyroid disease. Such forms of medullary thyroid carcinoma seem to be unrelated to iodine intake and may be pure or mixed with a follicular carcinoma. In these mixed thyroid carcinomas, only the neoplastic follicular pattern was seen on both cytological and histological examination. Routine measurements of serum calcitonin levels should therefore be considered an integral part of the diagnostic evaluation of thyroid nodules. Indeed, increasing the accuracy of diagnosis of medullary thyroid carcinoma encourages the surgeon to perform more radical treatment, thus achieving more frequent normalization of post-operative serum calcitonin levels.

Specific alterations of the basement membrane and stroma antigens in human pituitary tumours in comparison with the normal anterior pituitary. An immunocytochemical study.

Our report is the first immunocytochemical study of the principal elements of the basement membrane (BM) and connective tissue in normal and adenomatous human anterior pituitaries. In normal tissues, both the parenchymatous BM limiting the endocrine cell cords and the endothelial BM around the capillaries were continuous and were stained with anti-laminin (LM), anti-type IV collagen (CIV) and anti-fibronectin (FN) antisera. Antiserum to type I collagen (CI) stained the connective tissue only. The same antigens were investigated in 23 human pituitary adenomas, 6 of them having been diagnosed as locally invasive by the radiologist and the neurosurgeon. In all cases a lack of cordal structure was observed and the parenchymatous BM was completely absent (9 cases) or fragmented (14 cases). No correlation could be established between the extent of parenchymatous BM alterations and the invasive behaviour of the tumour. In contrast, a continuous endothelial BM was observed around the blood vessels in all cases and its presence was confirmed in double immunofluorescence experiments using anti-von Willebrand factor and anti-LM or anti-CIV antisera. Anti-FN and CI also stained the wall of the vessels. The tumours showed arterial development, in addition to the capillaries found in normal tissue. The present results favour the hypothesis of a decreased synthesis of parenchymatous BM by human adenomatous pituitary cells in comparison with normal cells and show that these tumours are the site of an active arterial neovascularization.

Transverse pattern modifications in a stable apertured laser resonator.

The effects of hard apertures on the transversal mode distribution and the output near and far field distributions are investigated both theoretically and experimentally. Wavefronts propagating in different directions inside a CO(2) laser cavity were measured at the same plane and found to have different transversal amplitude profiles. The influence of intracavity aperture's location and diameter on the near field distribution and far field beam quality were measured and calculated. Quantitative figures of merit are introduced to evaluate the departure of the transversal mode patterns from ideal Gaussians.