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Biomedical subjects

L Portmann

Publications and source records attributed to L Portmann.

At least 19 recordsLinked to original sources
PubMed2005

[Thyroiditis: an approach for the practitioner].

Thyroiditis represent commonly encountered thyroid disorders in clinical medicine. Autoimmune thyroiditis is frequent with various forms: Hashimoto's thyroiditis, subacute thyroiditis with lymphocytic and post-partum variants. In the absence of any changes in volume and function, Hashimoto's thyroiditis can be seen in a setting of a thyroid nodule, elevation of thyroid autoantibodies and by the pathologist in surgical or cytological materials. Presenting with fever, cervical pain and subtle signs of hyperthyroidism, subacute thyroiditis (De Quervain) represents often a challenge for an early recognition and an appropriate treatment. Acute thyroiditis and Riedel's thyroiditis are very uncommon, with cervical mass and pain.

Humans↗
PubMed2001

Sex-dependent variations and timing of thyroid growth during puberty.

Marked changes in thyroid function occur during puberty as an adaptation to body and sexual development. Characteristics of thyroid growth were investigated in 259 healthy adolescents (110 girls and 149 boys), aged 11--17 yr, in an urban area of Switzerland with sufficient iodine supply. The thyroid volume determined by ultrasonography was correlated with chronological age, body weight, body height, cervical circumference, body mass index, and body surface area (BSA). Iodide concentration was measured in urine. The increase in thyroid volume mainly occurred between 11--15 yr (age at maximum thyroid growth rate, 12.5 yr) and was best correlated with BSA in both genders (girls, r(2) = 0.38; boys, r(2) = 0.49). The BSA-related thyroid growth was almost constant throughout puberty in boys and similar in girls up to menarche, but 14.5% larger in girls after menarche (P < 0.01). Percentiles of thyroid volume were lower than WHO reference values despite low normal urinary iodide concentration (median, 0.75 micromol/L). These findings suggest that physiological thyroid growth during puberty is mainly influenced by growth factors involved in somatic development and further modulated by sex steroid secretion profiles. The thyroid growth spurt coinciding with menarche in girls may contribute to a higher incidence of goiter during mid- to late puberty.

Adolescent↗
PubMed1999

[Iodine nutrition and prevalence of goiter in adolescents in the Canton of Vaud].

Iodine deficiency disorders virtually disappeared in Switzerland after iodized salt was introduced in 1922 and the iodine content increased from 3.75 to 7.5 mg/kg in 1962 and to 15 mg/kg in 1980. However, a decreasing iodine intake has recently been reported again. The status of iodine nutrition in the Canton of Vaud was therefore assessed in 348 representative adolescents aged 11 to 17 years from the urban area of Lausanne in 1995. Thyroid size was estimated by inspection and palpation and thyroid volume measured by ultrasonography. Iodine concentration was determined in urine. Thyroid enlargement, as assessed by clinical examination, was found in 15% of the adolescents (stage 1a: 12.9%, 1b: 1.8%, 2: 0.3%), but its positive predictive value was low. The goitre prevalence determined by ultrasonography was only 1.4%. In addition, 4% of the adolescents had nodular or diffuse echo-structure abnormalities. Percentiles of thyroid volume as a function of sex, chronological age and body surface area were lower than WHO reference values. Median iodine concentration in urine was 92 micrograms/l (56.6% < 100 micrograms/l), slightly below WHO recommendations. Iodized cooking salt was consumed by 82% of the adolescents. In conclusion, the adolescents living in the Canton of Vaud had a low normal iodine intake with subclinical thyroid abnormalities. These findings support the recent decision to increase the salt iodine content to 20-30 mg/kg in order to prevent iodine deficiency during puberty and pregnancy. Percentiles of thyroid volume determined in the present study can be used as local reference.

Adolescent↗
PubMed1999

Complete hypogonadotropic hypogonadism associated with a novel inactivating mutation of the gonadotropin-releasing hormone receptor.

In this study, we describe a patient with a phenotype of complete hypogonadotropic hypogonadism who presented primary failure of pulsatile GnRH therapy, but responded to exogenous gonadotropin administration. This patient bore a novel point mutation (T for A) at codon 168 of the gene encoding the GnRH receptor (GnRH-R), resulting in a serine to arginine change in the fourth transmembrane domain of the receptor. This novel mutation was present in the homozygous state in the patient, whereas it was in the heterozygous state in both phenotypically normal parents. When introduced into the complementary DNA coding for the GnRH-R, this mutation resulted in the complete loss of the receptor-mediated signaling response to GnRH. In conclusion, we report the first mutation of the GnRH-R gene that can induce a total loss of function of this receptor and is associated with a phenotype of complete hypogonadotropic hypogonadism.

Adult↗
PubMed1999

Thyroid volumes and urinary iodine in Swiss school children, 17 years after improved prophylaxis of iodine deficiency.

Salt iodine content in Switzerland was raised from 7.5 to 15 mg per kg in 1980, and since then dietary iodine intake has been considered to be sufficient, even though a slight decrease due to imported food has recently been reported. The aim of this study was to establish normal values for thyroid volumes of school children who can be assumed to have had a sufficient iodine intake all their lifetime. Moreover. the present investigation was undertaken to verify that iodine sufficiency had been achieved equally in two regions each served by one of the two Swiss salt producers. Mean iodine concentration in urine spot samples from school children was 16.1 microg/dl, and it was identical in both the city of Lausanne (n=215) and the city of Solothurn (n=208). Thus it can be stated that in both cities (served by two different salt producers) iodine intake is equal and sufficient. Accordingly, thyroid volumes measured by ultrasound in school children aged 6 to 16 years were the same in both Lausanne (n=202) and Solothurn (n=207). Moreover, the age-adjusted median volumes at the 97th percentiles closely agree with and validate provisional international reference values recently proposed by the World Health Organisation and by the International Council for Control of Iodine Deficiency Disease.

Adolescent↗
PubMed1998

Pathologic fracture of the femur neck as first manifestation of a minute columnar cell carcinoma of the thyroid gland.

This case report concerns a 64 year-old woman who presented a pathologic fracture of the femur neck. Histologic examination of the performed bone biopsy disclosed the presence of a carcinomatous metastasis with unusual microscopic features. The site of the primary tumor could be unequivocally determined as being the thyroid gland, as immunostaining of the tumor cells showed positivity with anti-thyroglobulin. The thyroidectomy specimen weighed 149 g, was nodular and partially calcified. Exhaustive microscopic examination finally revealed the presence of a minute columnar cell carcinoma, 0.6 cm in diameter, with obvious vascular invasion. This case illustrates well 1) the usefulness of immunostaining with anti-thyroglobulin in cases of bone metastasis with unusual microscopic features and unknown primary, as well as 2) the aggressiveness of this rare type of carcinoma of the thyroid.

Carcinoma, Papillary↗
PubMed1997

Propranolol as an adjunct therapy for hyperthyroid tremor.

We evaluated the use of propranolol as an adjunct to carbimazole in the treatment of hyperthyroid tremor and tachycardia in a double-blind, cross-over and placebo-controlled study. Seven patients were given carbimazole plus either placebo or propranolol (40 mg) for 1 month and then switched to the alternative adjunct treatment for a further month. All patients showed significant improvements (p < 0.001) of heart rate and tremor amplitude after 1 or 2 months from baseline. One month after the baseline, the mean improvements of heart rate were 23% for the carbimazole + placebo group and 38% for carbimazole + propranolol group. Tremor also improved during the 1st month of the study by 31% in the carbimazole + placebo group versus 59% in the carbimazole + propranolol group. Whereas further improvements were observed in both variables in those receiving propranolol as the second adjunct treatment, this was not the case in those who received placebo during the same period. These findings confirm that the beta-blocker propranolol is a useful adjunct in the early treatment of both the tremor and tachycardia of hyperthyroidism.

Adrenergic beta-Antagonists↗
PubMed1996

Hashimoto's myoclonic encephalopathy: an underdiagnosed treatable condition?

We report two patients with subacute diffuse encephalopathy characterized by confusion, myoclonic encephalopathy, and mild akineto-rigid extrapyramidal signs in one case and by apathy, memory deficit, and partial complex seizures in the other. Hashimoto's thyroiditis with high titers of anti-thyroglobulin antibodies was diagnosed in both patients, who were unresponsive to anticonvulsant medication, but showed rapid neurological improvement following steroid treatment. On neuropsychological examination, predominant frontotemporal dysfunction was noted. Electroencephalographic activity was remarkable for its rhythmical delta activity, unresponsive to, or even paradoxically increased by, anticonvulsant treatment. On magnetic resonance imaging, atrophy with temporal predominance was found. These observations support the idea that this potentially treatable dementia and movement disorder should be classified as a separate clinical entity.

Adult↗
PubMed1996

Functional characteristics of three new germline mutations of the thyrotropin receptor gene causing autosomal dominant toxic thyroid hyperplasia.

We report three unrelated families in which hyperthyroidism associated with thyroid hyperplasia was transmitted in an autosomal dominant fashion, in the absence of signs of autoimmunity. Exon 10 of the TSH receptor gene was directly sequenced after PCR amplification from DNA of peripheral leukocytes. In one family, a C to A transversion resulted in an S505R substitution in the third transmembrane segment; in the second, an A to T transversion caused a N650Y substitution in the sixth transmembrane segment; and in the third family, an A to G transition resulted in an N670S substitution in the seventh transmembrane segment. When expressed by transfection in COS-7 cells, each mutated receptor displayed an increase in constitutive stimulation of cAMP production; no effect on basal accumulation of inositol phosphates (IP) could be detected. In binding studies, cells transfected with wild-type or mutated receptors showed similar levels of expression, with the mutated receptors displaying similar or slightly increased affinity for bovine TSH (bTSH) binding. Cells transfected with S505R and N650Y mutants showed a similar cAMP maximal TSH-stimulated accumulation over the cells transfected with the wild type, whereas N670S transfectants showed a blunted response with an increase in EC50. A higher IP response to 100 mU/mL bTSH over that obtained with the wild-type receptor was obtained in cells transfected with N650Y; in contrast, cells transfected with S505R showed a blunted IP production (50% less), and the N670S mutant completely lost the ability to stimulate IP accumulation in response to bTSH. The differential effects of individual mutations on stimulation by bTSH of cAMP or IP accumulation suggest that individual mutant receptors may achieve different active conformations with selective abilities to couple to Gs alpha and to Gq alpha.

Amino Acid Sequence↗
PubMed1994

Simultaneous assay for three types of thyrotropin receptor antibody activities using FRTL-5 cells in patients with autoimmune thyroid diseases.

The relationships between the different circulating thyrotropin receptor antibodies (TSH-R-abs) in autoimmune thyroid disease (AITD) are complex. In order to investigate them, we have developed an assay for the simultaneous measurement of three types of TSH-R-abs: TSH-binding inhibiting immunoglobulin (TBII): thyroid-stimulating antibody (TS-ab) and TSH-stimulation blocking antibody (TSB-ab). A large number of patients with Graves' disease (GD)--untreated and treated--Hashimoto's thyroiditis (HT), primary myxedema (PM) and non-immune goiter (NIG) were investigated. In untreated Graves' patients the frequency of positive TS-ab and TBII sera was found to be 90 and 69%, respectively, the presence of TS-ab and/or TBII being detected in 98%. After long-term antithyroid treatment administered to GD patients, the frequency of positivity of both TBII and TS-ab was decreased, whether hyperthyroidism was cured or not. The TSB-ab was detected in the serum of 8% of patients with GD, and the frequency of TSB-ab did not increase following treatment and alteration in thyroid function. No significant correlation was found between TSB-ab and thyroid function in Graves' patients. Besides, we found that all the GD patients presenting positive TSB-ab were also TBII positive. A follow-up study of the three TSH-R-abs was performed in 35 patients with GD during a mean of 14.3 +/- 8.5 months (4-34 months) of antithyroid drug treatment. Ten out of 24 patients (42%) with positive TBII and 16 out of 32 (50%) with positive TS-ab turned from positive to negative during the time of follow-up. Regarding relapse in hyperthyroid GD, we found that TS-ab was positive in 80% and TBII was positive in 40% of the patients with Graves' relapse, indicating that the presence of TS-ab is a better index for relapse prediction in Graves' hyperthyroidism than TBII. The TSB-ab was found with higher frequency in HT and PM than in GD, i.e. 21%, 18% and 8%, respectively., The TSB-ab positivity was correlated significantly with TBII in our patients with AITD when TSB-ab was positive. This new simultaneous assay of the three TSH-R-abs should be very helpful for further investigation of the autoimmune aspects of AITD and it should help us to progress in a better understanding of the pathogeny of the different AITDs.

Adult↗
PubMed1992

[Moderate Paget's disease treated with pamidronate (APD): experience in 43 patients with a single 60 mg infusion of varying duration of 1-to-24 hours].

Pamidronate disodium (APD) given as a single 60 mg intravenous infusion over 24 hours was shown to be an effective treatment for Paget's disease of bone. To further improve the feasibility of a simple treatment that ensures compliance in elderly outpatients (pts), we investigated the effectiveness of a single 60 mg APD intravenous infusion given over 8 hours (12 pts), 4 hours (9 pts) and 1 hour (10 pts) compared with that over 24 hours (12 pts). Infusion rate of APD was 7.5, 15 and 60 mg/h respectively, in comparison with 2.5 mg/h previously. Clinical improvement and biochemical remission were observed in all patients. Side effects, limited to mild transient fever and local transient increase in bone pain, occurred in 9 patients (2-3 pts in each group). There was no difference in the fall of plasma alkaline phosphatase and of urinary hydroxyproline between the 4 infusion rates. Plasma alkaline phosphatase (U/l, mean +/- SEM) decreased from 263 +/- 34 to 110 +/- 8 (1 h infusion), from 251 +/- 26 to 102 +/- 9 (4 h), from 237 +/- 23 to 95 +/- 9 (8 h) and from 256 +/- 29 to 97 +/- 7 (24 h), from day 0 to day 180 respectively (all p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Comparison of a rapid (2-h) versus a slow (24-h) infusion of alendronate in the treatment of hypercalcemia of malignancy.

Alendronate (aminohydroxybutylidene bisphosphonate) is a potent inhibitor of bone resorption but the role of the duration of intravenous infusion in its efficacy profile is unclear. In a two-centre, parallel, randomized, double-blind study, 20 patients with tumoral hypercalcemia received a single 10-mg i.v. infusion over either 2 h (group A, n = 10) or 24 h (group B, n = 10). Recurrences (n = 6) were retreated using the same regimen. Pretreatment plasma calcium (Ca) was 3.32 +/- 0.08 mM (mean +/- SEM) for all patients. Treatment A and B were associated with similar temporal profiles for onset, time to reach normocalcemia, (6 vs 5 days), nadir (day 6: 2.45 +/- 0.06 vs 2.43 +/- 0.08 mM) and time to relapse (day 21). Normocalcemia (2.15-2.55 mM) was achieved in seven (A) and nine (B) patients with other cases being partial responders (Ca: 2.65-2.76 mM). A significant decrease of urinary calcium and hydroxyproline excretion and a significant increase of PTH accompanied Ca normalization in both groups. Ca response was 50% lower on 2nd treatment with alendronate. Both treatments were well tolerated with transient mild fever being the most common adverse experience. In conclusion, whether infused over 2 or over 24 h, a single dose of 10 mg alendronate led to normalization of tumoral hypercalcemia in a large majority of cases.

Aged↗
PubMed1991

Thyroid microsomal antigen in Graves' thyroid is not different from that in normal thyroid.

Differences from normal in microsomal antigen (M-Ag) may be involved in the development of autoimmune thyroid disease. We compared the M-Ag in Graves' thyroid immunologically and biochemically to that in normal thyroid. The concentration of M-Ag, measured with an enzyme-linked immunosorbent assay, was significantly greater in the Graves' microsomes than in normal microsomes. Binding of a patient's microsomal antibody to Graves' microsomes was completely inhibited when the serum was first incubated with normal thyroid microsomes. Sodium dodecylsulfate-polyacrylamide gel electrophoresis and Western blotting were done with a monoclonal antibody to denatured M-Ag. In both Graves' and normal thyroids, M-Ag existed as 107-, 101-, and 95-kDa peptides. After incubation with V8 protease, the residual antigenic peptide had a molecular weight of less than 60,000 and after incubation with trypsin, 95- and 87-kDa peptides and several smaller antigenic peptides were found. There were no significant differences in the pattern of normal and Graves' microsomes after digestion. Two-dimensional gel electrophoresis of Graves' microsomes showed that the isoelectric point for the 107-kDa peptide was at pH 7.2; that for the 101-kDa peptide was at pH 6.2, and that for the 95-kDa peptide was at 6.5. These values were not different from those observed for normal microsomes. These results indicate that M-Ag in Graves' thyroid does not differ from that in normal thyroid, and that microsomal antibodies in autoimmune thyroid disease probably do no arise from differences in the antigen.

Autoantigens↗