Emergence of murine typhus in La Réunion, France, 2012-2017.

OBJECTIVE: Murine typhus (MT) is an acute zoonosis caused by Rickettsia typhi, a flea-borne rickettsiosis. The first autochthonous case was reported in 2012. Once autochthonous transmission of Rickettsia typhi was proven, we performed a prospective study to describe and raise awareness of this often-misdiagnosed disease among physicians. PATIENTS AND METHODS: We performed a prospective observational study of MT cases in La Réunion from 2012 to 2017. MT cases were defined as clinically compatible illnesses with a specific positive serology and/or PCR. RESULTS: Sixty-one confirmed cases were collected. The main clinical features were prolonged fever (90%), asthenia (87%), and headaches (79%). The main biological abnormalities were elevated liver enzymes (84%) and thrombopenia (75%). Renal function was normal in 90% of cases; it was an important feature because leptospirosis is a frequent cause of acute renal failure. A seasonal factor was observed with 79% of cases reported in the warm season and most of them in the west and south of the island (i.e., the dry areas). CONCLUSION: MT is an emerging disease in La Réunion, and local conditions could lead to an endemic situation. Cases of acute undifferentiated fever with headaches should guide to the diagnosis of MT especially in the warm season and dry areas. Leptospirosis is an alternative diagnosis, which differs from MT by its epidemiological characteristics and by the associated frequent renal dysfunction.

Pulmonary arterial hypertension in adult onset Still's disease: a case report of a severe complication.

BACKGROUND: Adult onset of Still's disease (AOSD) is a rare systemic inflammatory disease. Cardiorespiratory complications are mainly represented by pleural and pericardial disorders and are less frequent than cutaneous and articular complaints. Pulmonary arterial hypertension (PAH) occurring in AOSD is rarely described in literature. CASE PRESENTATION: We present the case of a young patient who developed severe PAH 2 years after diagnosis of AOSD. This is a rare and severe complication which is probably underestimated. CONCLUSIONS: PAH in AOSD can be lethal, and unfortunately its occurrence is unpredictable. Echocardiographic screening of AOSD patients should be evaluated in further trials. Currently, the most suitable treatment is still unknown.

Mismatch negativity (MMN) evoked by sound duration contrasts: an unexpected major effect of deviance direction on amplitudes.

OBJECTIVE: Verify and explore unexpected results suggesting an effect of deviance direction (shorter or longer deviants) on the amplitude of MMNs evoked by sound duration contrasts. METHODS: MMNs were recorded using the oddball paradigm on ten adults. Four standard stimulus durations (100, 150, 200 and 250ms) were used and deviants were 50% shorter or longer. Behavioral data (hit rates, d', and reaction times) were collected after the electrophysiological sessions. RESULTS: MMNs were larger for short than for long deviants. There was no effect on MMN latencies. Hit rates and d' data were almost at ceiling level for all conditions even for the longest standard - long deviant combination in which the MMN was abolished. CONCLUSIONS: We argue that the deviance direction effect on MMN amplitudes can be explained by the delay between the moment of deviance detection and the end of the deviance quantification process. SIGNIFICANCE: A major effect of deviance direction on amplitudes was confirmed. This effect, which was confined to electrophysiological data, is to be taken into account when using duration contrasts to probe the processing of temporal information.

Axonal cell-adhesion molecule L1 in CNS myelination.

Of the axonal signals influencing myelination, adhesion molecules expressed at the axonal surface are strong candidates to mediate interactions between myelinating cells and axons. The recognition cell-adhesion molecule L1, a member of the immunoglobulin superfamily has been shown to play important roles in neuronal migration and survival, and in PNS myelination. We have investigated the role of axonally expressed L1 in CNS myelination. In co-cultures of myelinating oligodendrocytes and neurons derived from murine brain, we demonstrate that, before myelination, L1 immunoreactivity is confined to neurites. After myelination commences, L1 expression is downregulated on myelinated axons and adjacent, but not yet myelinated, internodes.Interfering with L1 before the onset of myelination, by adding either anti-L1 antibody or L1-Fc fusion proteins to the culture medium, inhibits myelination. In addition, in purified cultures of oligodendrocytes, L1-Fc fusion protein prevents lysophosphatidic acid-induced activation of the mitogen-activated kinase (MAP)-kinase pathway. Together, our data indicate that L1 is involved in the initiation of CNS myelination, and that this effect might involve the dephosphorylation of oligodendroglial phosphoproteins.

[Hemophagocytosis associated with an Escherichia coli sepsis: a case report]. / Syndrome d'activation macrophagique associé à une septicémie à Escherichia coli: à propos d'un cas.

INTRODUCTION: Hemophagocytic lymphohistiocytosis syndrome (HLS) is defined by activated macrophage proliferation. These cells phagocyte the blood elements. This syndrome can be primary as an autosomal recessive disease or secondary to neoplasia, immune diseases or infections-viral, parasitary or bacterian. CASE: Our case concerns an association of HLS and Escherichia coli (E. coli) sepsis in a metastatic prostatic cancer. The evolution was rapidly improved by antibiotics alone. The clinical and biological aspects as well as the differential diagnosis are discussed. CONCLUSION: The HLS is fatal. It can be caused by a severe infection, even an E. coli sepsis. The treatment focused on etiology can be sufficient.

Exacerbation of sleep-apnoea related nocturnal blood-pressure fluctuations in hypertensive subjects.

Obstructive sleep apnoea syndrome (OSAS) induces marked haemodynamic fluctuations during sleep that might be deleterious to the cardiovascular system. The influence of daytime blood pressure (BP) levels and aging on short-term BP variability during sleep in OSAS patients was investigated. Twenty-nine subjects with newly-diagnosed untreated OSAS were categorised into three groups: normotensive subjects aged <50 yrs (n=10); subjects aged <50 yrs with untreated hypertension (n=8); and normotensive subjects aged >50 yrs (n=11). Beat-by-beat BP was recorded with a Finapres device during polysomnography. The average values+/-SD of apnoea-related BP elevations and the values of the frequency distribution of all BP variations during sleep were assessed to estimate short-term BP variability. Apnoea-related systolic (or diastolic) BP elevations were significantly greater in hypertensives than in normotensives aged <50 yrs (50.3+/-4.88 versus 30.7+/-2.14 mmHg, p<0.001), as was the SD of systolic (or diastolic) BP variations during sleep (19.6+/-2.22 versus 11.1+/-0.73, p<0.001). Short-term BP variability was not significantly increased in normotensive elderly patients. To conclude, the results suggested that systemic hypertension is associated with a greater exacerbation of short-term variability during sleep in obstructive sleep apnoea syndrome patients.

Effect of celiprolol treatment in hypertensive patients with sleep apnea.

The effects of a beta-blocker, celiprolol, on sleep and arterial blood pressure (BP) were evaluated during a single-blind study in seven hypertensive patients with sleep apnea. Diurnal ambulatory BP measurements with an automatic cuff-inflation device and polysomnography with simultaneous Finapres BP recording were performed separately on consecutive days at the end of two 21-day treatment periods involving placebo followed by celiprolol (200 mg/day). Age was 59 +/- 2.5 yr (m +/- sem) and body mass index 33.2 +/- 2.3 kg. m-2. Diurnal ambulatory BP was significantly lower with celiprolol than with placebo (systolic 139 +/- 4 vs 152 +/- 5 mmHg, diastolic 86 +/- 2 vs 96 +/- 2 mmHg). The apnea-hypopnea index was similar under celiprolol and placebo (48 +/- 7.4 vs 53 +/- 7.8, respectively), as were the total sleep time and percent of duration of the different sleep stages. Individual average BP values were significantly lower during REM sleep under celiprolol but remained similar under celiprolol and placebo in the other sleep stages. Variability of nocturnal BP (assessed by the SD of distribution of BP variations) was not affected by celiprolol. In conclusion, celiprolol which decreased daytime BP, did not affect sleep pattern or respiratory disturbances, or nocturnal BP variability related to apnea.

Nasal resistance in snorers with or without sleep apnea: effect of posture and nasal ventilation with continuous positive airway pressure.

We investigated the effects of posture and nasal ventilation with continuous airway pressure (CPAP) on nasal resistance in snorers with or without obstructive sleep apnea (OSA). Posterior rhinomanometry was performed in 70 snorers referred for polysomnography and in 11 nonsnoring volunteers, (1) in the seated posture; (2) and (3) after 10 minutes in the supine position, before and after inhalation of oxymetazoline; and (4) 10 minutes after return to the seated position. The effect of CPAP on posterior rhinomanometry was also examined in the nonsnorers and in 12 of the snorers. Changing from the seated to the supine position resulted in an increase in resistance in snorers and nonsnorers (resistance supine 182 +/- 10.9% and 128 +/- 6.7% respectively of seated value, p < 0.05). After oxymetazoline instillation, resistance in the supine position decreased but remained higher in snorers than baseline value in the seated position. Effects of posture and oxymetazoline were similar in snorers with or without sleep apnea. During nasal ventilation with CPAP, resistance was 30 +/- 3.8 and 45 +/- 4.4% of value before CPAP in snorers and nonsnorers, respectively (p < 0.05). These effects of posture and CPAP were also observed when resistance was measured with anterior rhinomanometry. In conclusion, nasal resistance measured with posterior rhinomanometry in the supine position is not predictive for OSA. Nasal ventilation with CPAP resulted in an acute and marked decrease in nasal resistance.

Short-term variability of blood pressure during sleep in snorers with or without apnea.

In normal subjects, the level and variability of blood pressure decrease during non-rapid eye movement (non-REM) sleep. In contrast, sleep apnea is associated with large swings in nocturnal pressure. In this study, we evaluated a computer-derived index of all-night blood pressure variability in normotensive snorers with or without sleep apnea. We also examined this index in snorers receiving medical treatment for coexistent ischemic heart disease. Beat-to-beat blood pressure was recorded with a photoplethysmographic device (Finapres) throughout polysomnography. Subjects were categorized into four groups: those without cardiovascular disease without or with sleep apnea (> or = 15 apnea plus hypopnea per hour of sleep), and those with ischemic heart disease without or with sleep apnea. A frequency distribution histogram of all increases and decreases of blood pressure according to their amplitudes was drawn and the SD of the distribution used as an estimation of variability. Mean systolic and diastolic pressures during the total sleep time were not different among the four groups. In contrast, the SD of the distribution of systolic and diastolic pressure variations that were higher in the apneic than in the nonapneic groups (P < .05) correlated with apnea plus hypopnea (P < .0001) and transient electroencephalographic arousal number per hour of sleep (P < .0001). In both apneic and nonapneic subjects, blood pressure variability as assessed by SD decreased during stages 3 and 4 of non-REM sleep compared with stages 1 and 2 and REM sleep (P < .001). Blood pressure variability was similarly increased in apneic subjects with or without ischemic heart disease. We speculate that in apneic individuals with coexistent ischemic heart disease, pressure variability that is increased despite treatment with beta-blockers or calcium antagonists may be a risk factor for acute coronary events.

Evaluation of an ambulatory device, CID 102, in the diagnosis of obstructive sleep apnoea syndrome.

Diagnosis of obstructive sleep apnoea syndrome (OSAS) is usually performed during overnight polysomnography in the sleep laboratory. In an attempt to simplify the diagnostic strategy, we compared an ambulatory device, CID 102, with polysomnography during the same night in the laboratory in 50 consecutive patients referred for polysomnography. The CID 102 device monitors oxygen saturation, heart rate, body position and tracheal breath sounds. An acoustic pressure sensor is placed on the suprasternal notch. Signals coming from this sensor are amplified and analysed in three different channels, according to their frequency and energy. CID respiratory disturbance index is defined as the number, per hour of analysis time, of apnoeas lasting more than 10 s plus episodes of desaturation by 4% or more associated with pauses lasting from 7-10 s or snores. The polysomnographic data were recorded on paper (Reega 2000, Alvar) and analysed manually. Polysomnographic apnoea-hypopnoea index (AHIp) was defined as the number of apnoeas plus hypopnoeas per hour of sleep. The sensitivity, specificity, positive predictive value and negative predictive value of various CID respiratory disturbance index (> or = 5, > or = 10, > or = 15 and > or = 20 per hour) in diagnosing obstructive sleep apnoea syndrome were determined. When OSAS was diagnosed as AHIp > or = 15, sensitivity and specificity of a CID respiratory disturbance index > or = 5 were 73 and 62%, respectively. Positive predictive value of CID respiratory disturbance index > or = 10 for AHIp > or = 10 was 94%. CID 102 false negative patients had only hypopnoeas without any desaturation.(ABSTRACT TRUNCATED AT 250 WORDS)

[Obstructive sleep apnea syndrome in adults and cardiovascular risk]. / Syndrome d'apnées obstructives du sommeil de l'adulte et risque cardiovasculaire.

Sleep obstructive apnea syndrome (SOAS) is a common condition with a strong male predominance. Its incidence is more than 1 percent in the population as a whole. It exists in snorers. Both snoring and SOAS are linked to the presence of abnormalities (congenital or acquired) of the upper respiratory tract. The nocturnal cardiovascular consequences of SOAS are directly linked to apnea. Bradycardia occurs during apnea and tachycardia when ventilation restarts. Paroxysmal nocturnal hypertension is a constant feature. Even in individuals who are normotensive during the day, each restarting of ventilation is accompanied by peaking of blood pressure. The pulmonary artery pressure curve follows that of systemic blood pressure. Complications begin when SOAS has been present for several years: 1) Chronic: permanent systemic hypertension is common (56 percent of SOAS). It is often refractory to antihypertensive treatment. 2) Acute: the onset of myocardial infarction and of cerebrovascular accidents explains the heavy mortality of SOAS (37 percent at 8 years in untreated individuals with a number of episodes of apnea exceeding 20 per hour of sleep). Other acute complications are less common: acute pulmonary edema, nocturnal sudden death. These events may be prevented by treatment suppressing apnea: actuarial survival curves are then superimposable upon those of the population as a whole. Thus SOAS is a cardiovascular risk factor which is remarkably reversible by specific treatment, though which most often passes unrecognized.

Is pulsed Doppler echocardiography an adequate method to evaluate left ventricular function during filling in hypertensive patients?

Pulsed Doppler tracings of the mitral inflow are often proposed to describe left ventricular function during filling in hypertensive patients. The tracings are determined by the complex interaction of left atrial pressure and left ventricular relaxation, diastolic compliance and contractility of the left atrium. They strongly depend on preload and, thus, do not allow precise characterization of the left ventricle. In addition, they vary with age, heart rate and the site of measurement. The modifications caused by the presence of hypertensive hypertrophy are not specific: similar changes are seen for example, in the presence of hypertrophic cardiomyopathy or coronary heart disease, but are absent in highly trained athletes in spite of very significant physiologic hypertrophy.

[Conduction disorders in Cheyne-Stokes respiration caused by cardiac insufficiency]. / Troubles de la conduction au cours de la respiration de Cheyne-Stokes due à l'insuffisance cardiaque.

This report describes a case of Cheyne-Stokes respiration linked to heart failure, with periodic disturbances of atrioventricular conduction during the augmentation phase of the tidal volume. The circulatory retardation caused by heart failure induced a phase lag of the negative retroaction system and secondarily an oscillation in the respiratory command. The conduction disturbances resulted from vagal stimulation of multifactorial origin. The atrioventricular conduction disturbances were analogous to those seen in other periodic respiratory diseases.

[Clinical electrophysiologic properties of magnesium and correlations with its anti-arrhythmia efficacy in acquired torsade de pointes]. / Propriétés électrophysiologiques cliniques du magnésium et corrélations avec son efficacité anti-arythmique dans les torsades de pointe acquises.

Recently, intravenous administration of low doses of magnesium has proved remarkably effective in the treatment of acquired torsade de pointe, but its electrophysiologic effects remain poorly understood. Three clinical cases are reported in three distinct situations (quinidine treatment, hypokalemia, bradycardia with complete atrioventricular block). These cases confirm the efficacy of magnesium, which acts without notable modification of ventricular cycles or the duration of repolarization. In ten patients undergoing intracavitary exploration, the electrophysiologic parameters were analyzed before and after injection of magnesium sulfate (35 mg/kg). Only three parameters were significantly altered; the corrected sinusal recovery time (increase from 245 +/- 92 ms to 296 +/- 96 ms), the effective nodal refractory period (increase from 333 +/- 98 ms to 346 +/- 93 ms), and the Wenckebache period (decrease from 157 +/- 28/min to 144 +/- 21/min). No changes were noted in other parameters, notably ventricular (QT interval, QRS duration, HV interval, and effective ventricular refractory period). The arrhythmic action on the ventricle is therefore remarkable and is not accompanied by patent electrophysiologic effects. The efficacy of magnesium in torsade de pointe may suggest action on calcium currents.

[Development of aortic valve stenosis in infants and children. Apropos of 66 cases hospitalized from 1973 to 1984]. / Evolution des sténoses aortiques valvulaires du nourrisson et de l'enfant. A propos de 66 cas hospitalisés de 1973 à 1984.

Sixty-six children aged over 6 months hospitalized for isolated aortic valve stenosis without cardiac failure but with a transvalvar systolic pressure gradient of more than 40 mmHg were followed up and re-evaluated for a mean period of 5.4 +/- 3.5 years. Twenty-two children who were asymptomatic, had no ST-T changes and had a less than 60 mmHg gradient were not operated upon; they remained stable over a mean period of 5.4 +/- 3.4 years; their gradient was not significantly modified (53 instead of 51 mmHg) and none of them underwent surgery. Forty-four children with symptoms and/or a more than 60 mmHg gradient underwent valvotomy under extracorporeal circulation without mortality. Surgery was effective against the major symptoms in all cases, and it reduced the gradient from 75 +/- 25 to 36 +/- 18 mmHg at the expense of aortic regurgitation in 7 cases, 2 of them with significant haemodynamic repercussions. During the follow-up period (5.8 +/- 3.7 years) 1 patient died of bacterial endocarditis, 5 were reoperated upon (with prosthesis in 4) without mortality and with 4 good results, and 1 patient underwent valvoplasty which proved partially effective but resulted in moderate aortic regurgitation. All other children are now doing well; 29 are completely asymptomatic and without ST-T changes at rest or during exercise. We conclude that aortic valve stenoses with moderate gradient are very stable at mid-term and that surgical valvotomy is a generally effective and low-risk procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

[Herpetic encephalitis: prognostic elements in adults and children (49 cases)]. / Encéphalite herpétique: éléments de pronostic chez l'adulte et l'enfant (49 cas).

In 49 cases (26 children, 23 adults) of proven Herpes simplex encephalitis, the authors studied the influence of age, disturbances of consciousness, time of diagnosis and therapy on patients' outcome, as well as the prognostic value of EEG data. Mortality was low in late childhood and young adulthood in spite of the constancy and depth of coma; it was very high in newborns and adults over 40 years of age and it was always correlated with the severeness of initial consciousness disturbances. The onset of periodic complexes (in 65% of the children and 78% of adults on the first EEG) does not systematically imply a poor outcome. Correlations between these EEG patterns and bioptic or surgical data tend to prove that these periodic complexes are already present in a prenecrotic state. Reversibility may be complete. On the other hand, the association between a contralateral focus or diffusion of initial abnormalities and an early coma imply a poor prognosis (12 deaths and 2 major sequellae in 14 cases). The importance of early presumptive diagnosis and therapeutical onset is stressed. The only cases of complete recovery are found among young adults treated early (surgery for older cases) thanks to an initial typical EEG. In young children, first clinical symptoms are often not evocative. Great importance should be attached to the onset of partial seizures and interictal loss of consciousness in a feverish child (24 out of 26 cases). Antiviral therapy should be started as soon as a Herpes simplex encephalitis is suspected, since the new antiviral drugs have a relatively low toxicity and do not interfere with the immunological diagnosis.

[An acute meningo-encephalitis with a favourable prognosis and occasional severe electrical and clinical changes; infectious mononucleosis meningo-encephalitis (author's transl)]. / Une méningo-encéphalite aiguüe d'évolution favorable avec tableau électroclinique parfois gravissime: la méningo-encéphalite de la mononucléose infectieuse.

Four cases of severe meningo-encephalitis in patients with infectious mononucleosis (IMN) are reported. In three cases the clinical context suggested a mononucleosis. In the other case there was fever but only isolated neurological signs, which demonstrates the importance of serological diagnostic tests because of the benign prognosis of this affection. In fact, neurological complications of IMN are considered to be reversible even though deaths have occurred from respiratory failure, from polyradiculoneuritis, or bulbar involvement. In the cases reported, the onset of a deep coma with loss of reflexes and pauses in respiration required resuscitation therapy, which enabled vital functions to be restored and complete recovery to be obtained. Electro-encephalographic changes were marked by the severity of the initial changes in the tracings with very slow delta waves and prolonged electrical silences which were, however, reversible. The prognostic value of the EEG has to be stressed as improvement in the EEG always preceded clinical improvement.