Value of continuous monitoring of the electrocardiogram in asymptomatic subjects

The authors analysed the prevalence of atrioventricular conduction defects and sinus node dysfunction by Holter monitoring in three population groups with similar clinical characteristics: 50 controls (Group I), 17 physically fit subjects with an atrioventricular conduction defect on the resting ECG which was usually asymptomatic (Group II), and 48 professional pilots who were also physically fit but who had no conduction defects on resting ECG (Group III). The 24 hour recordings showed: --a similar incidence of sinus dysrhythmias and atrioventricular conduction defects in the three groups although the frequency of low degree block was a little higher in sportsmen; --a preponderance of the association of first degree block and nocturnal Luciani-Wenckebach periods, sometimes with episodes of Mobitz II block; --the absence of progression to high-degree atrioventricular block. Holter monitoring would therefore seem to be a good method of detecting and following up abnormalities of sinus node function and atrioventricular conduction defects in asymptomatic patients. In addition, it gives a qualitative and quantitative assessment of the recorded changes and provides a means of monitoring their evolution.     

Guided bone regeneration for immediate non‐submerged implant placement using bioabsorbable materials in Beagle dogs

The aim of the present study was to evaluate the combined application of different bioabsorbable materials for healing of residual peri‐implant defects after placement of non‐submerged implants into fresh extraction sockets. Second and third mandibular premolars were extracted from 10 Beagle dogs, the coronal part of the distal sockets were surgically enlarged and this was followed by immediate placement of specially designed hollow‐screw non‐submerged dental implants. For each animal, the coronal peri‐implant defects were further treated with one of the 4 following procedures: 1) no treatment, control site: 2) grafting with porous hydroxyapatite (HA); 3) collagen membrane tightly secured around the implant and over the defect and 4) grafting with HA covered with a collagen membrane. After 16 weeks of healing, specimens were removed from the mandibule and prepared for a histomorphometric evaluation. The bone-to-implant contact length (BIC) was measured and compared amongst the different treatment modalities. In the defect area, the irregular bone regeneration was similar between all the treatment procedures ( P >0.10). In the sites covered with a collagen membrane alone, the total BIC (47%) was greater than in control sites (28.7%. P <0.05) or sites grafted with HA (22.2%, P <0.02). Total BIC in sites treated with the HA‐membrane combination (43%) was only significantly different from sites treated with HA ( P <0.10). It is concluded that the use of bioabsorbable materials results in a limited increase of osseointegration when used in conjunction with immediate placement of non-submerged implants, although the principle of the one stage surgical approach can be maintained.     

Relationship between achievement goal orientations and perceived motivational climate on intrinsic motivation

This study examines first the relationship of perceived motivational climate and goal orientation to indices of intrinsic, extrinsic motivation and amotivation, and second their respective role in predicting these indices of motivation. A total of 160 students enrolled in physical activity classes volunteered to participate. Results of Pearson correlation analyses indicated that students who perceived their class climate as emphasizing mastery were more likely to feel self-determined. Hierarchical regression analyses revealed that perceived motivational climate was a better predictor of all indices of motivation than goal orientations. Results, discussed according to the achievement goal perspective and the hierarchical model of intrinsic and extrinsic motivation, highlight a possible motivational process explaining how the motivational climate overrides goal orientations.     

Acute changes in forearm haemodynamics produced by cigarette smoking in healthy normotensive non-smokers are not influenced by propranolol or pindolol

Summary The aim of the present study was to examine the effect of cigarette smoking in healthy non-smokers on blood pressure and forearm haemodynamics after acute oral administration of non-selective -adrenoceptor blockers with and without intrinsic sympathomimetic activity, viz. pindolol 15 mg and propranolol 80 mg. A preliminary study was done to compare cigarette smoking and sham smoking to evaluate the time-course of the haemodynamic effects of cigarette smoking. The second experiment was then carried out in the same six volunteers, according to a double-blind randomized placebo-controlled crossover design, to evaluate the possible effect of pre-treatment with -adrenoceptor blockers on blood pressure, heart rate and forearm haemodynamics (forearm blood flow, brachial artery diameter and brachio-radial pulse-wave velocity) measured at baseline, during smoking and every five minutes up to 1 h afterwards.No major difference from placebo in blood pressure or forearm haemodynamics was found and pre-treatment with beta-blockers did not prevent the acute vascular effects of cigarette smoking.     

Orbital complications of sinusitis in adults

Orbital complications of sinusitis are rare in adults but delayed diagnosis is vision and life threatening. We report our experience in 6 patients to present clinical history, bacteriology and discuss the modality of treatment. There were 4 young men and 2 women, aged from 16 to 79 years old. Only one patient had an immunocompromised underlying condition (HIV infection). Four patients had preseptal abscesses and three post septal cellulitis or abscess (one patient had preseptal abscess and post septal abscess and hematoma). Two patients had a complete unilateral loss of light perception. Pathogens encountered were Streptococcus species: 4, strict anaerobes: 1, Pseudomonas aeruginosa: 1 (patient with AIDS). Patients recovered from infection with antibiotics in 6 and surgery in 5 but sequellar blindness occurred in 2 patients. Our experience emphasizes the necessity of antibiotic treatment in bacterial sinusitis and importance of early diagnosis and appropriate management of complications.     

Submandibular puncture of the facial vein: An original route for endovascular therapy of cavernous sinus dural fistulas

Introduction

Carotid cavernous sinus fistulas are a potentially severe pathology. Their basic standard treatment is an occlusion of the CCF performed by retrograde venous catheterization via the inferior petrous sinus. When the inferior petrous sinuses are occluded, other alternative venous routes are possible with various subsequent difficulties and risks. We report an original and safe method for endovascular treatment using submandibular puncture of the facial vein.

Clinical cases

We report 4 cases of patients with severe unilateral carotid cavernous sinus fistula associated with the occlusion of both inferior petrous sinuses. A submandibular surgical puncture of the ipsilateral inferior facial vein permitted the catheterization of the fistula. Complete occlusion of carotid cavernous sinus fistula was obtained by using a combination of microcoils and Onyx™.

Discussion

When inferior petrous sinuses are occluded, endovascular treatment of carotid cavernous sinus fistulas is more difficult. After reviewing the other treatment options reported in the literature and their respective advantages and adverse effects, we describe an original technique based on the surgical puncture of the ipsilateral facial vein. The occlusion of the fistula is then obtained by using a combination of microcoils and Onyx™.

Conclusion

When the inferior petrous sinuses are occluded, an endovascular treatment for a carotid cavernous sinus fistula can be performed using an original and secure method. This method relies on a simple surgical puncture of the facial vein in the submandibular region, which then permits a retrograde catheterization of the carotid cavernous sinus fistula with no significant risk.     

Hand deformity and sensory loss due to Hansen's disease in American Samoa

We report the prevalence of sensory loss and hand deformity in 63 patients with Hansen's disease in American Samoa. Open ulceration, the most common deformity, was present in 41% of patients; sensory abnormalities were present in 54% and were bilateral in 65%. The presence of abnormal sensibility correlated with a high percentage of other deformities. Hand abnormalities were most prevalent in lepromatous patients and were related to a prolonged duration of disease. Nerve thickening did not appear to be a helpful clinical finding to assess the degree of sensory loss.     

What determines the frequency of fast network oscillations with irregular neural discharges? I. Synaptic dynamics and excitation-inhibition balance

When the local field potential of a cortical network displays coherent fast oscillations ( approximately 40-Hz gamma or approximately 200-Hz sharp-wave ripples), the spike trains of constituent neurons are typically irregular and sparse. The dichotomy between rhythmic local field and stochastic spike trains presents a challenge to the theory of brain rhythms in the framework of coupled oscillators. Previous studies have shown that when noise is large and recurrent inhibition is strong, a coherent network rhythm can be generated while single neurons fire intermittently at low rates compared to the frequency of the oscillation. However, these studies used too simplified synaptic kinetics to allow quantitative predictions of the population rhythmic frequency. Here we show how to derive quantitatively the coherent oscillation frequency for a randomly connected network of leaky integrate-and-fire neurons with realistic synaptic parameters. In a noise-dominated interneuronal network, the oscillation frequency depends much more on the shortest synaptic time constants (delay and rise time) than on the longer synaptic decay time, and approximately 200-Hz frequency can be realized with synaptic time constants taken from slice data. In a network composed of both interneurons and excitatory cells, the rhythmogenesis is a compromise between two scenarios: the fast purely interneuronal mechanism, and the slower feedback mechanism (relying on the excitatory-inhibitory loop). The properties of the rhythm are determined essentially by the ratio of time scales of excitatory and inhibitory currents and by the balance between the mean recurrent excitation and inhibition. Faster excitation than inhibition, or a higher excitation/inhibition ratio, favors the feedback loop and a much slower oscillation (typically in the gamma range).