Performance comparison of MSK and QPSK optical long haul DWDM transmission with coherent detection.

We performed long-haul WDM transmission experiments to compare 10 Gbit/s MSK and QPSK modulation with a channel grid of 12.5 GHz. A standard link setup with inline dispersion compensation was applied in combination with coherent detection and following offline signal processing. Both modulation formats showed nearly equal performance bridging about 4000 km at a BER of 10(-3).

[Münchausen syndrome by proxy - two case reports] / Síndrome de Münchausen por procuração - relato de dois casos.

OBJECTIVE: To draw pediatrician's and healthcare worker's attention to the Munchausen syndrome by proxy, a serious kind of child abuse. PATIENTS AND METHODS: We report the clinical history and the evolution of two patients, based on a review of these patient's files in the Children's Rights Committee of the Hospital da Criança Santo Antônio, for further discussion. The first case reports a 5- year old child that presented difficult-controlling seizures; this case had an excellent prognosis after being examined by several specialists and later on by the Children's Right Committee. The second case reported is a 5-month old infant who presented apnea crisis accompanied by cyanosis and seizures. COMMENT: Munchausen syndrome by proxy is a relatively rare clinical entity, that can be difficult to be diagnosed, leading to unnecessary and potentially harmful diagnostic procedures to the child.

[Intrauterine insemination with the husband's sperm: conclusions of five years experience]. / Inséminations intra-utérines avec sperme du conjoint (IIU-AC): conclusions de 5 ans d'expérience.

We analyzed retrospectively 936 intrauterine insemination (IUI) cycles with husband's sperm (384 couples). Superovulation and induction monitoring occurred in the majority of cases; IUI was timed 36-40 h after ovulatory hCG. The overall pregnancy rate per cycle (PR/C) was 11.4% (107/936). Data analysis demonstrated that PR/C decreased with infertility duration, woman's age (especially after 38 years old) and number of attempts (significantly after the 4 th cycle). Superovulation (in particular by antiestrogens) and induction monitoring seemed to provide an increase in cycle pregnancy rate. Highest PR/C were observed in dysovulation and male infertility groups. In cases of sperm defects, our data showed that 2 parameters had a significant influence on pregnancy outcome: the number of motile progressive inseminated spermatozoa (> 300,000) and the spermatozoa survival rate after 24 h (> 50%). As a conclusion, intrauterine insemination can be proposed as a satisfying treatment of infertility, if precise protocol is followed and its indications well-defined.

[Thyrotoxic periodic paralysis. Discussion of the role of Na-K-ATPase, apropos of a case]. / La paralysie périodique thyréotoxique. Discussion du rôle de la Na-K- ATPase, à propos d'une observation.

We report a case of thyrotoxicosis periodic paralysis (TPP), occurring as a complication of a Grave's disease in a 31 year-old Caucasian male. It has been suggested that the membrane Na-K pump was involved in the pathogenesis of this complication. In our patient, before treatment, the activity of erythrocyte Na-K-ATPase was significantly decreased, as compared with healthy subjects (228nmol Pi/mg prot/h versus 298 + 60 nmol Pi/mg prot/h) and went back to normal levels post treatment. The activity of this enzyme seems to be prone to genetics factors as well as environmental ones. This would explain the higher incidence of TPP in male and in asiatic people. However, other reports emphasize the role of Na-K-pump-independent potassium influx, which would be more specific of TPP.

Selenium status in relation to clinical variables and corticosteroid treatment in rheumatoid arthritis.

Plasma selenium levels, erythrocyte selenium levels and activity of the selenoenzyme glutathione peroxidase in erythrocytes were determined in patients with rheumatoid arthritis (RA) and acute inflammatory arthritis. Results were compared with those from age and sex matched controls. These variables were not statistically different from controls in patients with inflammatory arthritis and in patients with RA not treated with corticosteroids. No correlation was found in RA between plasma selenium biological variables of inflammation and most clinical indices of disease severity. Therefore, acute or chronic inflammation was not the main factor that accounted for low plasma selenium levels in RA. Corticosteroid treatment, particularly at high doses (20-60 mg prednisolone/day), was significantly related to the depressed plasma selenium levels of some patients with RA. The mechanisms underlying this modification remain poorly understood.

Selenium deficiency.

Selenium is undoubtedly an essential trace element: its involvement in GPx structure, the presence of deleterious effects of selenium deficiency in animals, and the recognition of deficiency states in man attest to its importance. However, if the consequences of selenium deficiency in man are now widely recognized, the mechanisms underlying these conditions are poorly understood. The definition of the exact role of selenium in human homeostasis has been hampered by the lack of a sensitive parameter, usable in routine investigation, to assess selenium status. Measurements of plasma and urinary levels, although useful in clinical practice, are inadequate indicators. The only true evidence of selenium deficiency lies in a positive response to selenium therapy. Deficiency states have been demonstrated for inhabitants of regions where selenium supply is limited, in protein-energy malnutrition, and in patients maintained on total parenteral nutrition without selenium supplementation. The benefit of selenium supplementation, together with other antioxidant drugs, in non-deficient subjects is still a matter of debate; its protective effect in neoplastic, cardiovascular and neurological degenerative diseases is not yet proven.

Serum PABA and fluorescein in the course of Bz-Ty-PABA and pancreolauryl test as an index of exocrine pancreatic insufficiency.

Forty-six subjects (20 chronic pancreatitis, 7 chronic liver disease, 7 recovered from acute pancreatitis, 2 Crohn's disease, and 10 healthy controls) classified by S-C test as having normal pancreatic function (26 subjects), or moderate (10 subjects) and severe (10 cases) pancreatic insufficiency, were given, on different days, 1 g of oral PABA or 348 mg of oral fluorescein dilaurate. At the 1st, 2nd, and 4th hours (PABA) and the 2nd, 4th, and 6th hours (fluorescein) serum samples were taken for assay. In the presence of severe exocrine pancreatic insufficiency, the sensitivity of the fluorescein serum levels was higher than that observed for the PABA (100% and 80%, respectively), and quite similar to that shown by the urinary tests (100% and 70%, respectively). On the contrary, in presence of moderate pancreatic insufficiency, both the urinary test (pancreolauryl and (PABA) give a sensitivity higher than that found in the serum tests (30-40% and 10-30%, respectively). The parallel combination of both the serum or urinary tests does not significantly improve the sensitivity of the single test. These results suggest that the serum PABA and serum fluorescein tests can be valid choice when a prolonged urinary collection is difficult, i.e., in children and in elderly patients. However, the slight diagnostic gain does not justify the routine use of both urinary and serum tests.

Useful sample handlings for reversed phase high performance liquid chromatography in emergency toxicology.

Some physicochemical treatments of biological samples, before being injected into a liquid chromatograph, are discussed. The advantages of dilution, liquid and solid extraction are compared referring mainly to unpublished results. Assays of antiepileptic drugs, caffeine, theophylline, tricyclic antidepressants, valproic acid, and meprobamate are used to demonstrate the importance of sample handlings in toxicological analyses in which reversed phase high performance liquid chromatographies are applied.

Degradation study of catecholamines, indole amines and some of their metabolites in different extraction media by chromatography and electrochemical detection.

Optimal conditions for the extraction from brain tissue and the simultaneous quantification of catechol and indole derivatives were determined after a systematic degradation study in water and perchloric acid. The roles of three parameters, namely temperature, presence of antioxidant agents, and time, were considered. Adrenaline, noradrenaline, dopamine, homovanillic acid, 5-hydroxytryptophan, 5-hydroxyindole acetic acid, serotonin, and epinephrine were separated by HPLC and detected electrochemically. The results indicated a great instability of the indole derivatives at an ambient temperature, in an acid medium, and in the absence of a protective agent. Therefore, when perchloric acid has to be used for deproteinization, the lowest concentration (0.1 M) is preferable. The samples have to be kept on ice, in darkness, and protected by ascorbic acid and sodium ethylenediamine tetracetate.

Selenium, zinc and copper in Down's syndrome (trisomy 21): blood levels and relations with glutathione peroxidase and superoxide dismutase.

Increased superoxide dismutase and glutathione peroxidase activities have been reported in erythrocytes of subjects with Down's syndrome. Since these enzymes contain specific trace-elements as essential components, we have determined copper, zinc and selenium levels in plasma and erythrocytes of 29 trisomy 21 patients compared with 32 age-matched controls and examined the relations with the enzymes' activities. In plasma, mean zinc and copper levels were normal, but selenium was found to be significantly decreased (p less than 0.001). In red cells, the increase of activity of the selenoenzyme glutathione peroxidase (p less than 0.001) was not accompanied by an increase of erythrocyte selenium, but a significant correlation was found between these two values (r = 0.67, p less than 0.001). Zinc and copper levels in red cells were significantly higher than normal (p less than 0.001) and this increase could be partly explained by the increased activity of the copper and zinc containing enzyme superoxide dismutase (p less than 0.001). Low plasma selenium and the strong relation between erythrocyte selenium and glutathione peroxidase activity we found in Down's syndrome should stimulate interest in a more detailed investigation of selenium status and metabolism of these patients.

Plasma and erythrocyte zinc, copper and selenium in cystic fibrosis.

Plasma and erythrocyte zinc, copper and selenium were measured in 20 cystic fibrosis children, aged 7 to 19 years. Mean plasma zinc and copper levels were not different from those in age-matched controls but very low zinc levels occurred sporadically. Plasma zinc concentrations were significantly lower in patients with moderate-to-severe growth retardation and with severe pulmonary disease as compared to patients without growth failure and with moderate pulmonary disease. Mean erythrocyte zinc (40.8 micrograms/g Hb +/- 9.2) and copper levels (3.56 micrograms/g Hb +/- 0.50) were very significantly increased (30.4 micrograms/g Hb +/- 5.2 and 2.73 micrograms/g Hb +/- 0.30 respectively, for age-matched controls). Mean plasma and erythrocyte selenium levels (63 ng/ml +/- 15 and 329 ng/g Hb +/- 86) were significantly lower than those in age-matched controls (82 ng/ml +/- 13 and 404 ng/g Hb +/- 116). The trace element concentrations in erythrocytes are discussed in relation to the activities of the copper- and zinc-containing enzyme superoxide dismutase and the seleno-enzyme glutathione peroxidase. We consider that more data on trace element metabolism in CF should be collected before specific supplementation is considered.