Broca's area damage is necessary but not sufficient to induce after-effects of cathodal tDCS on the unaffected hemisphere in post-stroke aphasia

BACKGROUND

The inter-individual variability of behavioral effects after tDCS applied to the unaffected right hemisphere in stroke may be related to factors such as the lesion location.

OBJECTIVE/HYPOTHESIS

We investigated the effect of left Broca's area (BA) damage on picture naming in aphasic patients after cathodal tDCS applied over the right BA.

METHODS

We conducted a study using pre-interventional diffusion and resting state functional MRI (rsfMRI) and two cross-over tDCS sessions (TYPE: sham and cathodal) over the right homologous BA in aphasic stroke patients with ischemic lesions involving the left BA (BA+) or other left brain areas (BA-). Picture naming accuracy was assessed after each session. Inter-hemispheric (IH) functional balance was investigated via rsfMRI connectivity maps using the right BA as a seed. Probabilistic tractography was used to study the integrity of language white matter pathways.

RESULTS

tDCS had different effects on picture naming accuracy in BA+ and BA- patients (TYPE × GROUP interaction, F(1,19): 4.6, P: 0.04). All BA- patients except one did not respond to tDCS and demonstrated normal IH balance between the right and left BA when compared to healthy subjects. BA+ patients were improved by tDCS in 36% and had decreased level of functional IH balance. Improvement in picture naming after cathodal tDCS was associated with the integrity of the arcuate fasciculus in BA+ patients.

CONCLUSIONS

Behavioral effects of cathodal tDCS on the unaffected right hemisphere differ depending on whether BA and the arcuate fasciculus are damaged. Therefore, IH imbalance could be a direct consequence of anatomical lesions.

Asymmetry of Bispectral Index (BIS) in severe brain-injured patients treated by barbiturates with unilateral or diffuse brain injury

OBJECTIVE

Bispectral index (BIS) may be used in traumatic brain-injured patients (TBI) with intractable intracranial hypertension to adjust barbiturate infusion but it is obtained through a unilateral frontal electrode. The objective of this study was to evaluate differences in BIS between hemispheres in two groups: unilateral frontal (UFI) and diffuse (DI) injured.

PATIENTS AND METHODS

Prospective monocenter observational study in 24 TBI treated with barbiturates: 13 UFI and 11 DI. Simultaneous BIS and EEG was recorded for 1h. Goal of monitoring was a left BIS between 5 and 15. Biases in BIS were considered as clinically relevant if greater than 5. Differences in biases were interpreted from both statistical (Mann-Whitney test) and clinical points of view.

RESULTS

Mean BIS in the two hemispheres remained in the same monitoring range. There were statistic and clinical differences in some values in the two groups of patients (15% of bias greater than I5I in UFI group and 10% in DI group). BIS monitoring allowed the adequate number of bursts/minutes to be predicted in 18 patients and did not detect an overdosage in 2.

CONCLUSIONS

While asymmetric BIS values in TBI patients occur whatever the kind of injury, they were not found to be clinically relevant in most of these heavily sedated patients. Asymmetrical BIS monitoring might be sufficient to monitor barbiturate infusion in TBI provided that the concordance between BIS and EEG is regularly checked.

Cardiovascular effects of a PEGylated apelin

Several studies have documented cardiovascular effects of apelin, including enhanced inotropy and vasodilation. However, these cardiovascular effects are short lived due to the predicted short circulating half-life of the apelin peptide. To address this limitation of apelin, we pursued N-terminal PEGylation of apelin and examined the cardiovascular effects of the PEGylated apelin. A 40kDa PEG conjugated apelin-36 (PEG-apelin-36) was successfully produced with N-terminal conjugation, high purity (>98%) and minimum reduction of APJ receptor binding affinity. Using an adenylate cyclase inhibition assay, comparable in vitro bioactivity was observed between the PEG-apelin-36 and unmodified apelin-36. In vivo evaluation of the PEG-apelin-36 was performed in normal rats and rats with myocardial infarction (MI). Cardiac function was assessed via echocardiography before, during a 20 min IV infusion and up to 100 min post peptide infusion. Similar increases in cardiac ejection fraction (EF) were observed during the infusion of PEG-apelin-36 and apelin-36 in normal rats. However, animals that received PEG-apelin-36 maintained significantly increased EF over the 100 min post infusion monitoring period compared to the animals that received unmodified apelin-36. Interestingly, EF increases observed with PEG-apelin-36 and apelin-36 were greater in the MI rats. PEG-apelin-36 had a prolonged circulating life compared to apelin-36 in rats. There were no changes in aortic blood pressure when PEG-apelin-36 or apelin-36 was administered. To our knowledge this is the first report of apelin PEGylation and documentation of its cardiovascular effects.

Measurement of the ZZ production cross section and limits on anomalous neutral triple gauge couplings in proton-proton collisions at sqrt[s] = 7 TeV with the ATLAS detector

A measurement of the ZZ production cross section in proton-proton collisions at sqrt[s] = 7 TeV using data corresponding to an integrated luminosity of 1.02 fb(-1) recorded by the ATLAS experiment at the LHC is presented. Twelve events containing two Z boson candidates decaying to electrons and/or muons are observed, with an expected background of 0.3 ± 0.3(stat)(-0.3)(+0.4)(syst) events. The cross section measured in a phase-space region with good detector acceptance and for dilepton masses within the range 66 to 116 GeV is σ(ZZ → ℓ+ ℓ- ℓ+ ℓ-)(fid) = 19.4(-5.2)(+6.3)(stat)(-0.7)(+0.9)(syst) ± 0.7(lumi) fb. The resulting total cross section for on-shell ZZ production, σ(ZZ)(tot) = 8.5(-2.3)(+2.7)(stat)(-0.3)(+0.4)(syst) ± 0.3(lumi) pb, is consistent with the standard model expectation of 6.5(-0.2)(+0.3) pb calculated at the next-to-leading order in QCD. Limits on anomalous neutral triple gauge boson couplings are derived.

Very long chain fatty acid and lipid signaling in the response of plants to pathogens

Recent findings indicate that lipid signaling is essential for plant resistance to pathogens. Besides oxylipins and unsaturated fatty acids known to play important signaling functions during plant-pathogen interactions, the very long chain fatty acid (VLCFA) biosynthesis pathway has been recently associated to plant defense through different aspects. VLCFAs are indeed required for the biosynthesis of the plant cuticle and the generation of sphingolipids. Elucidation of the roles of these lipids in biotic stress responses is the result of the use of genetic approaches together with the identification of the genes/proteins involved in their biosynthesis. This review focuses on recent observations which revealed the complex function of the cuticle and cuticle-derived signals, and the key role of sphingolipids as bioactive molecules involved in signal transduction and cell death regulation during plant-pathogen interactions.

Reproducibility of a task description questionnaire for working pregnant women

The objective of this study was to evaluate the reproducibility of a Task Description Questionnaire that was designed to investigate exposures to, and influential factors for, problematic tasks experienced by working pregnant women. The questionnaire comprised questions concerning 22 task components (covering working posture, manual material handling, work pace, prolonged postures and others), eight influential factors contributing to problematic tasks, discomfort (measured using a body map) and level of effort to perform the tasks. Reproducibility of the questionnaire was assessed by interviewing participants on two occasions one week apart for interviews at both 20 and 34 weeks of pregnancy. Eleven and 13 problematic tasks were reported by 21 working pregnant women at 20 and 34 weeks of pregnancy, respectively. These tasks were surveyed using the Task Description Questionnaire. Kappa statistics and correlation coefficients (supplemented by paired t-tests) were used to examine the reproducibility of responses to the questionnaire. The results showed that most of the variables were measured with very good or satisfactory reproducibility. The reproducibility of exposure to work posture was higher than that of exposure to manual material handling. There was no significant difference between test and retest means for the discomfort scores measured on the body map, except for the maximum discomfort score for the whole body in the 34 weeks survey. The study suggests that the questionnaire can be reliably used in the study of problematic tasks experienced by pregnant women. But an initial preview of the questions by the subjects and explanation of the questions given to the subjects by the interviewer may help to produce more reliable results.

Disagreement between height/weight classifications of underweight, normal weight, and obesity in peritoneal dialysis patients

Peritoneal dialysis (PD) patients are classified as underweight, normal weight, or obese by height/weight indices including body mass index (BMI) and the body weight/desired weight (W/DW) ratio. We compared these classifications of degree of obesity in 378 women and 555 men on PD. We used these cut-off values: for underweight, BMI < or = 18.5 and W/DW < or = 0.9; for obesity, BMI > or = 30.0 and W/DW > or = 1.2. The W/DW values were calculated assuming first a small frame, then a medium frame, and finally a large frame for all subjects. Regardless of sex or skeletal frame, BMI correlated highly with W/DW (r value between 0.98 and 0.99); however, the range of BMI values corresponding by linear regression to the normal range of W/DW (0.9-1.2) was narrower than the range of "normal" BMI (18.5-30.0). Consequently, regardless of sex or skeletal frame, smaller fractions of the patient population were classified as underweight or obese by BMI standards than by W/DW standards. The degree of agreement of the classifications of subjects as underweight, normal weight, or obese by BMI and W/DW was evaluated by Cohen's kappa ratio. The kappa ratio varied between 0.47 and 0.58, indicating a reasonable--but not high--degree of agreement beyond chance. The highest kappa ratios were obtained assuming a medium skeletal frame for both women and men. Substantial discrepancies are observed in the classification of PD patients as underweight, normal weight, or obese by BMI and W/DW. Further research is needed to identify the height/weight index that has the strongest association both with clinical outcomes and with other, more precise measurements of body fat content.

Fluoxetine modulates motor performance and cerebral activation of patients recovering from stroke

In order to determine the influence of a single dose of fluoxetine on the cerebral motor activation of lacunar stroke patients in the early phase of recovery, we conducted a prospective, double-blind, crossover, placebo-controlled study on 8 patients with pure motor hemiparesia. Each patient underwent two functional magnetic resonance imaging (fMRI) examinations: one under fluoxetine and one under placebo. The first was performed 2 weeks after stroke onset and the second a week later. During the two fMRI examinations, patients performed an active controlled motor task with the affected hand and a passive one conducted by the examiner with the same hand. Motor performance was evaluated by motor tests under placebo and under fluoxetine immediately before the examinations to investigate the effect of fluoxetine on motor function. Under fluoxetine, during the active motor task, hyperactivation in the ipsilesional primary motor cortex was found. Moreover, fluoxetine significantly improved motor skills of the affected side. We found that a single dose of fluoxetine was enough to modulate cerebral sensory-motor activation in patients. This redistribution of activation toward the motor cortex output activation was associated with an enhancement of motor performance.

Body mass index in patients with amputations on peritoneal dialysis: error of uncorrected estimates and proposed correction

"Weight-height" indices including percent of ideal weight (%IW) and body mass index (BMI) are used to estimate degree of obesity in populations and are predictors of survival in dialysis patients. Amputation affects the relationship between weight and height independently of the degree of obesity. Corrections of both %IW and BMI for amputation have been published, but a National (U.S.) computer nutrition program used in the authors' institution uses only the correction for %IW. This study had two parts: (1) To test whether the weight-height cut-off values for weight deficit (%IW 90%, BMI 20 kg/m2) and obesity (%IW 120%, BMI 30 kg/m2) are compatible, we performed linear regression of BMI on %IW in peritoneal dialysis (PD) patients without amputations. In 349 men, BMI = 0.834 + 0.226 (%IW), r = 0.979. From this regression, the 95% confidence interval (CI) of BMI is 19.2-23.1 kg/m2 if %IW is 90%, and 26.1-29.9 kg/m2 if %IW is 120%. In 260 women, BMI = 2.194 + 0.184 (%IW), r = 0.974. From this regression, the 95% CI of BMI is 15.7-21.8 kg/m2 if %IW is 90%, and 21.3-27.3 kg/m2 if %IW is 120%. (2) To identify the direction and magnitude of the error of uncorrected BMI (BMIu) in dialysis patients with amputations, we analyzed weight-height indices in two groups of men by the computer nutrition program, which corrects %IW, but not BMI for amputation, and by the corrected BMI (BMIc) formula. In group A (amputation without height loss, n = 11), %IW = 110.2% +/- 16.9%, BMIu = 23.6 +/- 2.7 kg/m2, BMIc = 26.4 +/- 3.8 kg/m2 (p < 0.001, BMIc vs BMIu), and 5 of the 11 BMIu values fell below the 95% confidence band of the regression of BMI on %IW in patients without amputations. In group B (amputation with loss of height, n = 6), %IW = 92.7% +/- 19.9%, BMIu = 33.9 +/- 10.7 kg/m2, BMIc = 22.1 +/- 4.4 kg/m2 (p < 0.005, BMIc vs BMIu), and 5 of the 6 BMIu values fell above the 95% confidence band of the regression of BMI on %IW in patients without amputations.

CONCLUSIONS

(1) The weight deficit cut-offs for %IW and BMI are compatible in non amputated men and women. (2) The obesity cut-offs for %IW and BMI are compatible in non amputated men, but not in non amputated women. (3) Amputation without height loss decreases BMIu, while amputation with height loss increases, in general, BMIu. (4) BMI should be corrected in PD patients with amputations.

Strategies for remote detection of life--DARWIN-IRSI and TPF missions

Having selected a general definition of a living system, we wonder whether a remote detection of such systems can be made, at least in some cases. Quite fortunately, we find that this seems possible. We describe the present status of missions with this goal.

Estimates of interdialytic sodium and water intake based on the balance principle: differences between nondiabetic and diabetic subjects on hemodialysis

Whether salt or water intake is the primary cause of interdialytic weight gain (deltaW) has important implication for the design of measures to prevent large deltaW. In 17 hemodialysis patients dialyzed against a bath containing 140 mmol/L of sodium, monthly predialysis serum sodium was compared with post dialysis serum sodium. A decrease in serum sodium in the interdialytic period would indicate that primary water consumption accounts for at least part of the deltaW. Interdialytic sodium intake, isotonic fluid gain (deltaW(isotonic)) and net pure water gain (deltaWH2O) were calculated by balance formulae. Serum sodium concentration was corrected in diabetic subjects to the value corresponding to euglycemia (100 mg/dl). Estimated interdialytic sodium intake was compared with the prescribed sodium intake and, in seven subjects, to sodium intake estimated from dietary records. Results for nondiabetic subjects (N = 9): [Na]post 139.3 +/- 1.9 mmol/L, [Na]pre 140.1 +/- 2.1 mmol/L (NS), deltaW 1.15 +/- 0.55 L/24 hr, deltaW(isotonic) 1.33 +/- 0.57 L/24 hr, deltaWH2O -0.20 +/- 0.58 L/24 hr, estimated sodium intake 206 +/- 75 mmol/24 hr, prescribed sodium intake 121 +/- 29 mmol/24 hr (p = 0.028). Results for diabetic subjects (N = 7): [Na]post 140.1 +/- 2.5 mmol/L, [Na]pre 137.7 +/- 3.1 mmol/L (p < 0.01), deltaW 1.26 +/- 0.38 L/24 hr, deltaW(isotonic) 0.59 +/- 0.63 L/24 hr, deltaWH2O 0.66 +/- 0.39 L/24 hr, estimated sodium intake 160 +/- 81 mmol/24 hr, prescribed sodium intake 124 +/- 30 mmol/24 hr (NS), glycosylated hemoglobin 9.7 +/- 2.8% (normal, 4.1-5.7%). In seven subjects, estimates of sodium intake from balance formulae (233 +/- 113 mmol/24 hr) were not different from estimates from dietary records (212 +/- 87 mmol/24 hr). Sodium intake accounted for all the interdialytic weight gain in nondiabetic subjects. In diabetic patients, only approximately half of the interdialytic weight gain was accounted for by sodium intake. The other half was due to pure water gain, probably caused by hyperglycemia.

[Molecular typing by pulsed field gel electrophoresis of Pseudomonas (Burkholderia) cepacia isolated from a nosocomial infection]

Because of the emergence of Pseudomonas (Burkholderia) cepacia, isolated among patients from an intensive care unit of the Hôpital Pellegrin (Bordeaux), strains were studied in the aim to determine the source and the mode of transmission of the bacteria. The study was performed on 44 isolates of P. cepacia from 21 patients (23 strains) or from the environment (16 isolates from ventilators and five from the distilled water used for these ventilators). Susceptibility to 23 antibiotics of these strains and endonuclease restriction polymorphism on their total DNA were determined. Pulsed field gel electrophoresis was performed after digestion of the genomic DNA, using three restriction enzymes. Results obtained by analysis of genotypic characteristics demonstrated the clonal origin of the P. cepacia epidemy in the different intensive care units, but did not localize the source of the infection.

Rowing performance and selected descriptive, field, and laboratory variables

The purpose of this study was to determine the relationships among measures of rowing performance and selected descriptive, field, and laboratory variables. Rowing performance of 20 intercollegiate oarswomen was assessed using a 2,500-m time test on a Concept II rowing ergometer, the rower's competitive experience, and the coach's ranking of the rowers. The oarswomen also underwent standardized descriptive tests including anthropometric measurements, field tests including 90-s rowing ergometer distance and weight lifting tests, and laboratory tests including VO2max and isokinetic knee extensor strength tests. Rowing ergometer times were highly related to competitive experience (rho = -0.86; p < 0.01) and coach's ranking (rho = 0.87; p < 0.01). VO2max was the only other variable to produce correlations greater than 0.71 with rowing performance. Although most of the correlations observed in the present study were poor to modestly high, they do document and quantify relationships, and suggest that training and testing techniques should be modified to be more rowing specific and that their usefulness with respect to positive transfer and prediction should be examined.

[Syndrome of resistance to thyroid hormones]

Although rare, thyroid hormone resistance syndrome should be suspected on a biological profile combining high thyroid hormone and non-suppressed TSH plasma levels. Resistance to thyroid hormone can be classified into 3 forms: generalized, pituitary and peripheral, all three showing tissue resistance heterogeneity from one person to another, and from one tissue to another in the same subject. In the generalized and pituitary forms, thyroid hormone levels are high with paradoxically normal or increased TSH levels. The TRH test still stimulates TSH secretion, and only the highest doses of T3 successfully suppress TSH secretion. In the generalized form, euthyroidism is usual, whereas in the pituitary form hyperthyroidism requires treatment in order to lower TSH secretion. In the peripheral form, various symptoms of thyroid hormone deficiency may be observed, contrasting with normal T3, T4 and TSH serum levels, and requiring supraphysiological doses of T3 for correction. In most cases, familial occurrence can be evidenced, with an autosomal dominant or sometimes recessive mode of inheritance. Genetic analysis has identified, in the generalized form, more than 10 mutations of the thyroid hormone receptor beta gene, all resulting in an alteration in the T3 binding domain of the receptor. In the autosomal dominant form, tissue resistance may result from a "dominant inhibitory effect" of the normal receptor function by the mutant receptor. All these thyroid hormone resistance syndromes constitute exceptional models for studying the mechanisms of action of thyroid hormones. Simultaneous observations of the mutated receptors with various clinical and biological phenotypes should further our understanding of thyroid hormone receptor function.

Changes in rowing ergometer, weight lifting, vertical jump and isokinetic performance in response to standard and standard plus plyometric training programs

The purpose of this study was to compare standard (S-weight plus rowing ergometer training) and standard plus plyometric (S+P-weight plus rowing ergometer training, plus plyometric exercises) programs on sport-specific and non sport-specific tests. Twenty-four female rowers completed the weight training or the weight training plus plyometric exercises three times per week and rowing ergometer training four times per week, 1 hr per session for 9 wks. Analysis of variance tests were used to compare S (n = 11; 5 novice and 6 experienced rowers) and S+P (n = 13; 7 novice and 6 experienced rowers) programs on the following sport-specific tests: 1) time to row 2,500 m and 2) distance rowed in 90 s; and on the following non sport-specific tests: 1) leg press, 1 RM, 2) leg press endurance, 3) bench pull 1 RM, 4) bench pull endurance, 5) vertical jump, 6-9) isokinetic knee extensor peak and average power during concentric and eccentric muscle actions and 10) angle of occurrence of peak torque during concentric muscle actions (isokinetic knee extension). Although experienced oarswomen scored significantly higher than did novice oarswomen on eight of 12 tests (p < 0.04), both levels of rower responded similarly to training. No significant differences were observed post-training between the S and S+P training programs (p > 0.05). These results do not discount the value of plyometric exercises, but indicate that the jump exercises used offered no advantages to intercollegiate oarswomen.

Antithyroid hormone antibodies induced by interferon-alpha

A 40-yr-old woman known for a multinodular goiter had hyperthyroidism. Treatment with antithyroid drugs and iodine therapy was effective. One year later, she received interferon-alpha for treatment of essential cryoglobulinemia. At that time, the patient was euthyroid. Testing for antithyroglobulin, antimicrosome, anti-TSH receptor, and antithyroid hormone antibodies was negative. After a 1-yr course of interferon-alpha, goiter enlargement was noticed. Apparently elevated free T3 and T4 serum values were measured by RIA, contrasting with clinical euthyroidism and normal TSH values. High serum levels of antithyroid hormone antibodies were found in the patient's serum, using a radiolabeled hormone immunoprecipitation assay. Antithyroglobulin and antimicrosome antibodies titers were also elevated and paralleled antithyroid hormone antibodies. After cessation of interferon-alpha therapy, clinical status and TSH levels remained normal, while thyroid hormone values and antithyroid hormone antibody levels progressively normalized. To our knowledge, this is the first report of antithyroid hormone antibodies induced by interferon-alpha. Since thyroid dysfunction is described in 10-15% of treated patients, the fact that interferon-alpha can induce antithyroid hormone antibodies has important implications: 1) the prevalence or intensity of thyroid dysfunction could be overestimated; and 2) artifactually elevated free T3 and T4 serum values could lead to inappropriate therapy of thyroid disease or cessation of interferon treatment.

Tracking with a restricted field of view: performance and eye-head coordination aspects

Vision through a restricted field of view (RFOV) is becoming increasingly common in aviation with the use of helmet mounted displays. Our first experiment investigated the influence of a narrow (20 degrees) binocular RFOV on performance during head-free visuo-manual tracking of a wide range (+/- 85 degrees) horizontally moving target. Second, the effects of two levels of RFOV (20 degrees, 70 degrees) on a similar tracking task presented with various eccentricities were compared to full field of view (FOV). Eye and head movement around the yaw axis were recorded and analyzed versus head-free visual pursuit alone. Tracking performance appeared moderately impaired when RFOV was set to 20 degrees, but did not improve with a 70 degrees field. Discomfort due to unusually large head movements was ruled out as a causal factor. Visuo-manual tracking apparently implies a need for head stability. RFOV degrades this basic requirement which, in turn, could explain performance impairment. Analysis of eye-head coordination characteristics following FOV task conditions supports this hypothesis.

Detection of myocarditis during the first year after discovery of a dilated cardiomyopathy by endomyocardial biopsy and gallium-67 myocardial scintigraphy: prospective multicentre French study of 91 patients

The purpose of this study was to assess the frequency of inflammatory lesions in the myocardium of subjects with dilated cardiomyopathy and to determine if there was any correlation between the results of two methods of evaluation, one (endomyocardial biopsy) invasive and the other (gallium-67 scintigraphy) noninvasive. Of 115 subjects recruited in seven centres, 91 met the inclusion criteria (left ventricular dilatation greater than or equal to 100 ml m-2 and ejection fraction less than 55% with normal coronary arteriography) and had endomyocardial biopsy (mean five specimens) and Ga-67 myocardial scintigraphy after several days. Scanning was considered doubtful 19 times and positive 13 times. The histologic count of mononuclear cells in the myocardial interstitium in 20 fields was greater than 5 cells field-1 in only four cases. No correlation was found between the two methods. Subjectivity in the choice of the criterion of positivity of Ga-67 scintigraphy and difficulties in identifying lymphocytes upon pathological examination were the major problems encountered. Despite limitations, both techniques suggest that cellular infiltrates are minimal and quite infrequent in dilated cardiomyopathy.

Multifactorial study of prognostic factors in differentiated thyroid carcinoma and a re-evaluation of the importance of age

A multivariate analysis of prognostic factors has been carried out with 375 cases of differentiated thyroid cancer (DTC) treated in the same centre by total thyroidectomy and 131I therapy. The patients have been followed for 5 to 23 years. The isolated prognostic roles of age, sex, clinical stage and histology were confirmed, but these factors were found to be strongly interrelated. Multifactorial analysis was conducted following Cox's model. It demonstrated that the prevalent role of clinical staging (nodular versus lobar or massive form) is as important as the initial presence of metastases (P = 0.0001). Histological assessment of differentiation, age and sex were of lesser importance. Thus, the most significant prognostic variable is clinical stage. These data must be taken into account when formulating management protocols for DTC.

Immunological studies of autoimmune thyroid disorders: abnormalities in the inducer T cell subset and proliferative responses to autologous and allogeneic stimulation

Various immunological parameters were investigated in patients with Hashimoto's thyroiditis (HT) and Graves' disease (GD). The total T cell numbers were significantly decreased in both diseases whether they were enumerated by E rosetting or by pan-T cell monoclonal antibodies (OKT3 and anti-Leu 1). This diminution was due to a loss in the inducer T cell subset (OKT4+/Leu 3a+) whereas the cytotoxic/suppressor T cells (OKT8+/Leu 2a+) were present at normal levels in both diseases. The B cells were significantly higher in GD patients than in controls but were not modified in HT patients. Monocyte percentages remained unchanged and DR+ cells were slightly increased in the two diseases. On the other hand, T lymphocyte responses to stimulation by autologous or allogeneic cells were significantly impaired in GD but not in HT whether cultures were performed in autologous plasma or AB serum. In addition, lymphocytes from normal subjects were unable to proliferate in auto- or allo-MLR in the presence of plasma from GD patients but they were reactive in the presence of HT plasma or AB serum. Taken together, these results suggest that the patients with autoimmune thyroid disorders exhibit a T cell imbalance within the OKT4+/Leu 3a+ subset. Moreover, this abnormality is correlated with the observation that autoreactive and alloreactive cells are defective in GD.

Motion sickness caused by rotations about Earth-horizontal and Earth-vertical axes

Rotation at constant angular velocity about the head's Z-axis, with the rotational axis horizontal (barbecue-spit rotation), causes motion sickness and illusory perceptions of bodily movement. To determine whether such rotations about the head's X- and Y-axes cause similar effects, and to test the validity of the mismatch theory of motion sickness, more than 200 tests (using vertical axes as well as horizontal axes) were administered to 14 subjects. Three different visual conditions were also investigated: normal external vision, vision of only the inside walls of the rotating capsule, and eyes closed in the dark. In Earth-horizontal rotation, the X- and Y-axis stimuli were found to be equally as effective in provoking sickness as was the original Z-axis stimulus, and a comparable loss of perception of gravity occurred for all three stimuli. The horizontal axis stimuli were found to be very effective in producing sickness in all the three visual conditions, but the external vision condition was significantly less effective than the other two conditions. The findings were generally inconsistent with the mismatch theory.

[Paradoxical effects of iodine overload on thyroid function]

Any chronic iodine overload resulting from long term ingestion of a medication or the administration of a non-resorbable contrast medium, may result in a goitre with or without hypothyroidism, and in particular in patients with a past history of thyroid disease. By contrast, the administration of iodine is no longer indicated in the treatment of enedmic goitres since the hypothesis of an iodine deficiency in the pathogenesis of such goitres may be excluded in most countries, and in particular western countries, and the risk of the development of thyrotoxicosis in such patients is not negligeable. It would thus be desirable that iodine no longer be used in the composition of medications when its presence is not indispensalbe and where, furthermore, it may contribute to developement of an increasingly disturbing iatrogenic complication.