[Central diabetes insipidus in adult patients--the first sign of Langerhans cell histiocytosis and Erdheim-Chester disease. Three case studies and literature review]. / Centrální diabetes insipidus u dospelých osob--první príznak histiocytózy z Langerhansových bunek a Erdheimovy-Chesterovy choroby. Popis trí prípadu a prehled literatury.

Central diabetes insipidus with an onset in adulthood is very rare. Unlike in children, central diabetes insipidus in adults is more frequently caused by inflammatory processes and neoplastic infiltrations that do not originate from the neuronal tissue than primary neuronal tissue tumours. Rare histiocytic neoplasias (Langerhans cell histiocytosis, xanthogranulomatosis and Erdheim-Chester disease) have a specific affinity to hypothalamus and the pituitary stalk not only in paediatric patients but also when occurring in adults. We describe 3 cases of central diabetes insipidus with an onset in adulthood. Diabetes insipidus was the first sign of Langerhans cell histiocytosis in 2 patients, and it was the first sign of Erdheim-Chester disease in one patient. MR imaging showed pathological infiltration and dilated pituitary stalks in all 3 patients. PET-CT proved useful in differential diagnosis, showing further extracranial pathological changes either on the basis of significant glucose accumulation or on the basis of CT imaging. The Langerhans cell histiocytosis in the first patient has also manifested itself as an infiltration of the perianal area with intensive accumulation of fluorodeoxyglucose (FDG) - SUV 8.6 and gingival inflammation indistinguishable from parodontosis. Histology of the perianal infiltrate confirmed Langerhans cell histiocytosis. Infiltration of the pituitary stalk disappeared from the MR image after 4 cycles of 2-chlordeoxyadenosin (5 mg/m2 5 consecutive days). The PET-CT of the 2nd patient showed only borderline accumulation of FDG in the ENT area, while simultaneously performed CT imaging showed cystic restructuring of the pulmonary parenchyma and nodulations consistent with pulmonary Langerhans cell histiocytosis. Bronchoalveolar lavage identified higher number of CD1 and S100 positive elements, consistent, once again, with pulmonary LCH also affecting pituitary stalk and ear canal. The PET-CT of the third patient showed increased activity in the long bones and ilium near the sacroiliac joint. Biopsy of the focus in the ilium confirmed foam histiocyte infiltration immunochemically corresponding to Erdheim-Chester disease. Additional imaging assessments revealed the presence of further signs of the disease. Pituitary infiltrate biopsy in this patient did not elucidate the diagnosis but resulted in complete panhypopituarism. Central diabetes insipidus in adulthood might be the first sign of so far undiagnosed extracranial disease, in our case of histiocytic neoplasias, and PET-CT has an excellent potential to detect extracranial symptoms of these conditions. Therefore, the high-risk pituitary stalk infiltrate biopsy should always be preceded by comprehensive examination aimed at identification of extracranial manifestations of the pituitary gland diseases.

[Langerhans cell histiocytosis in adult patients--a disease with many faces. Experience of a centre and an overview of the disease symptoms]. / Histiocytóza z Langerhansových bunek u osob dospelého veku--nemoc s mnoha tváremi. Zkusenosti jednoho pracoviste a prehled projevu nemoci.

Over a period of 18 years, 17 patients with proven Langerhans cell histiocytosis (LCH) were treated at the Haematological Clinic in Brno. In 13 of them, the disease was diagnosed at adult age, and 4 patients were referred to the centre with LCH diagnosed at early child age. One of these 4 patients suffered from repeated recurrences of the disease at adult age and was diagnosed with progressive neurodegenerative damage of the CNS at the age of 25 which in its terminal phase resulted in the patient's immobility, loss of sphincter control, incapacity to communicate and death at the age of 32. LCH was diagnosed at adult age in 13 patients. The form with primary bone involvement was detected in 8 out of 13 patients (62%). Only 2 of 13 patients (15%) had multiple bone lesions upon diagnosis, the remaining 6 patients (46%) had only one lesion at the time of diagnosis. Repeated recurrence of bone involvement was only recorded in 3 out of 13 patients (23%). The combination of recurrent bone involvement and the development of lung affection (dyspnoea, irritating cough, nodularities and cysts in HRCT images) were documented in 2 out of 13 patients (15%). One of the patients diagnosed with LCH at the age of37 had repeated recurrence of bone involvement, which was also treated by 2 cycles of high-dose chemotherapy and autologous transplantation. He died of bronchopneumonia due to the affection of the lungs by LCH at 48 years of age. Primary extraoseal (extamedular) involvement was diagnosed in 5 out of 13 patients (38%) (mandibular gum infiltration, single cervical node infiltration, hand skin infiltration, infiltration of the perineal region and infiltration of the hypophysial infundibular and primary lung form of LCH). In the 1st case, excision was the solution applied to the infiltration of the lingual side ofthe gums, without further recurrence. In the 2nd case, the infiltrated region of skin over the metacarpophalangeal joint was irradiated and the infiltration disappeared. In the 3rd case, the first sign ofthe disease was diabetes insipidus in a 34-year-old man, and an infiltrate in the anal region similar to condylomata acuminata. The diagnosis was confirmed 2 years after the development of diabetes insipidus from perianal infiltrates. After treatment with leustatin in 4 cycles (10 mg a day for 5 consecutive days), control MR showed that the infiltration in the hypophysial infundibular had disappeared, while the finding in the perianal region only regressed by 50% after therapy with leustatin, the reason for subsequent application of radiotherapy (20 Gy). The finding in the perianal region is normal one year after therapy, but substitution therapy with adiuretin is still necessary. The 4th patient was a case of LCH with primary pulmonary involvement diagnosed on the basis of HRCT and lavage with an immunohistochemical proof (expression of CD1 and of protein S-100) of a high number of Langerhans cells. The occurrence of LCH at adult age is rare and the disease may affect the skeleton as well as other organs. Therefore each new osteolytic lesion should be submitted for histological exam, as well as each pathologic formation, because diagnosing the disease without a microscopic and immunohistochemical exams is not possible. In the case of occurrence of diabetes insipidus at adult age, LCH should be considered as one of the possible underlying diseases. LCH pulmonary involvement should be considered in patients with an interstitial pulmonary process and the examinations should be focused accordingly (thoracoscopy with sampling for histological exams or bronchoalveolar lavage) plus the indispensable immunohistochemical examination.

Preparation and strength of poly(ethylene terephthalate) fiber bundles for model synthetic tendons.

Poly(ethylene terephthalate) fibers suited for model synthetic tendons were prepared on a pilot-plant scale by additional drawing (postdrawing) of commercial textile fibers texturized by false twist. The modified fibers have a tensile modulus of 7-9 GPa, a one-minute creep modulus of 5-6 GPa, tensile strength 0.55-0.63 GPa, and strain at break of 16-19%. It is essential for their application in synthetic tendons that plastic deformation was reduced to about 0.5%, which could be completely eliminated by subsequent mechanical conditioning of fibers. Since the strength of model tendons consisting of 20 vol % of fibers and of a hydrogel matrix is primarily determined by the strength of the fibers, some aspects of the theory of strength of fiber bundles are briefly recapitulated. The prediction is compared with earlier experimental results obtained for the synthetic tendons. Such an approach, taking into account the fiber-strength distribution in the bundle, predicts a strength of model tendons lower by 20-40% than does the rule of mixtures.