Resistin is a predictor of asthma risk and resistin:adiponectin ratio is a negative predictor of lung function in asthma.

BACKGROUND: Adipokines, such as resistin and adiponectin, modify inflammation and may contribute to increased asthma risk and severity in obese people. OBJECTIVE: To examine plasma resistin and resistin:adiponectin ratio (i) in asthmatics compared to healthy controls, (ii) according to asthma severity, obesity and gender (iii) following weight loss in obese asthmatics. METHODS: In a cross-sectional observational study of asthmatic adults (n = 96) and healthy controls (n = 46), plasma resistin and adiponectin were measured. In a separate intervention study, obese asthmatic adults (n = 27) completed a 10-week weight loss intervention and plasma resistin and adiponectin concentrations were analysed. RESULTS: Plasma resistin and resistin:adiponectin ratio were higher in asthma compared to controls and were higher again in subjects with a severe vs. mild-to-moderate asthma pattern. Amongst asthmatic subjects, resistin was not modified by gender or obesity, while adiponectin was lower in males and obese subjects. As a result, resistin:adiponectin ratio was higher in obese males, non-obese males and obese females, compared to non-obese females. In a logistic regression model, plasma resistin concentration was a predictor of asthma risk. In a multiple linear regression model, plasma resistin:adiponectin ratio was a negative predictor of FEV1 in asthma. Following weight loss, neither resistin, adiponectin nor resistin:adiponectin ratio was changed. However, the change (∆) in %body fat was associated with ∆ resistin:adiponectin ratio. Post-intervention ∆ resistin was negatively correlated with both ∆FRC and ∆RV. CONCLUSION AND CLINICAL RELEVANCE: This study demonstrates that resistin and resistin:adiponectin ratio are higher in asthma and are higher again in subjects who have more severe disease. Resistin:adiponectin ratio is highest in obese male asthmatics. As resistin is a predictor of asthma risk and resistin:adiponectin is a predictor of FEV1 in asthma, these adipokines may be contributing to the obese asthma phenotype, thus providing a potential therapeutic target for obese asthma.

Music perception in cochlear implant recipients: comparison of findings between HiRes90 and HiRes120.

CONCLUSIONS: Increased spectral resolution via implementation of perceptual channels with HiRes120 (PSP) would seem to provide better perception of music than with standard HiRes, mainly from the point of view of music appreciation as recorded via the questionnaire. More specific tests are required for appreciation of timbre, preferably by application of protocols based on perceptual attributes using rating scales, which would not be biased by knowledge of music. OBJECTIVE: The objective of this study was to verify the hypothesis whereby the implementation of perceptual channels in HiRes120 may lead to an improvement in the perception of music, owing to an increase in spectral resolution. SUBJECTS AND METHODS: Music perception was studied in 12 adult subjects, making a comparison between performance with HiRes90 and HiRes120 with perceptual channels. Quality of perception, loudness and rhythm were all assessed via a questionnaire. Further tests included timbre recognition trials and pitch ranking. RESULTS: Whereas there was a significant improvement in appreciation of music as seen by the questionnaire, timbre and pitch trials seemed to be biased by various subjective factors and require further study using different criteria.

Rhythms, synchrony and electrical coupling in the Locus coeruleus.

Electrical coupling of neurones is believed to promote synchronized activity. It may, however, also be a requirement for the maintenance of endogenous rhythmic activity in some systems. In en bloc isolated brainstem-spinal cord of the neonatal rat simultaneous whole cell recordings from pairs of LC neurones (n = 47 pairs) disclosed for the most part strongly synchronized activity which could take the form of tonic spiking or phasic bursts. Simultaneous whole cell recording from LC neurones and glia also revealed synchronized waves of depolarization in 7 of 17 pairs. This synchrony was partly due to respiratory-phased synaptic input and partly due to mechanisms, which were not dependent on chemical synapses. The gap junction uncoupler carbenoxolone suppressed non-synaptic rhythmic activity in LC neurones, but did not suppress either respiratory-phased synaptic input to these neurones or their excitatory response to increased CO(2). We give preliminary direct evidence for the existence of a current pathway between LC neurones, which is inhibited by carbenoxolone. Within the LC nucleus carbenoxolone-sensitive electrical coupling, which may involve neurone-glia as well as neurone-neurone interactions, may be required not just for synchronization, but also for the maintenance of rhythm.

Short-term study of the effect of speech coding strategy on the auditory performance of pre- and post-lingually deafened adults implanted with the Clarion CII.

OBJECTIVE: The auditory performance of cochlear implantees is linked to numerous variables, such as audiological characteristics, age and type of speech coding strategy. In recent years, many different ways of processing sounds have been developed, with possible implications for auditory performance. The purpose of this study was to evaluate the intra-individual differences of patients for speech perception tasks in quiet and in noise as a result of switching from a standard strategy [Continuous Interleaved Sampling (CIS)/Simultaneous Analog Strategy (SAS)] to Hi-Resolution (HiRes). MATERIAL AND METHODS: A total of 14 post-lingual adults implanted with the Clarion CII were selected for trials. At switch-on, six patients chose a CIS strategy and eight an SAS strategy. After an average period of 9.3 months, all patients were switched over to HiRes. All patients were tested (open-set mode) with bisyllabic words and sentences, in both quiet and noise [speech/noise ratio (SNR) = +10]. Testing was carried out after an initial period with the CIS/SAS strategy and 3 months after switching over to HiRes. RESULTS: After switch-over a significant improvement was seen for both speech in quiet (words +25.2%, sentences +10.8%) and speech in noise (words 44.8%, sentences 45.4%). CONCLUSION: Despite individual differences, all patients improved their performance with HiRes use, the greatest improvements being seen under unfavourable listening conditions (SNR = +10). Subjective improvements in speech discrimination and overall sound quality perception were reported even after the first week of HiRes use.

Cochlear implants in special cases: deafness in the presence of disabilities and/or associated problems.

The aim of the present study is to construct a reference model with the indication for the attitude, the requirements and the resources needed in order to be able to deal with deafness in the presence of disabilities or associated problems. The study group consisted of 13 adults and 18 children affected by profound deafness, with associated problems and disabilities, who were implanted with Clarion and Med-El devices. Selection criteria for candidacy to cochlear implantation and counselling, hospitalization, fitting and speech therapy/rehabilitation are described. Findings were assessed evaluating: (i) use of acoustic feedback, on the ground of Erber's model; (ii) self-sufficiency: assessed by a questionnaire; and (iii) social and family relationships: qualitative judgment based on direct observation, analysis of drawings and structured interviews with family, teachers and therapists. The whole group showed benefit from cochlear implantation, with particular satisfaction for post-lingual deaf-blind adults, as well as for subjects with associated psychopathologies and mental retardation. In conclusion, cochlear implants can improve life quality in profoundly deaf subjects with associated disabilities, increasing both listening and communication skills as well as self-sufficiency while family and social relationships tend to remain stable.

Delayed loss of residual hearing in Clarion cochlear implant users.

Hearing threshold has been measured in a group of patients following cochlear implantation with a Clarion device for the last eight years. The patients had received either a pre-curved carrier or the Hi-Focus I plus Electrode Positioner System (EPS). The assessment was carried out within the first post-operative week as well as at a later stage, between six and 87 months, post-operatively. Residual hearing thresholds were still measurable early after surgery in 24.5 per cent of the patients, without differences between the two different Clarion models. However, the number of subjects with measurable hearing dropped to 16.3 per cent as observed when hearing was measured at a later stage, with an equal distribution between the two groups of patients. From this study it has been possible to observe that only a limited number of patients maintain residual hearing after Clarion cochlear implantation, and that this tends to decrease further over time. Nevertheless, the performance of these patients for speech tests did not appear to be affected by deterioration of the pure-tone auditory threshold.

Central chemosensitivity of respiration: a brief overview.

In this introductory article we make use of the work reviewed in detail by a number of contributors to this Special Issue (Respir. Physiol., 2001) to provide an outline of current approaches to identifying brainstem CO(2)/pH-chemosensitive neurones. The section headings which we have adopted are intended to reflect particular issues rather than experimental techniques, though some of these issues arise out of the choice of preparation and the advantages and limitations which follow from such a choice. We have also considered whether, in spite of the diversity in the kinds of neurones usually considered to be chemosensitive, there are any indications for shared or uniform features. Again, this is based on the material published together in this volume. Finally, and more speculatively, we suggest that the dendritic organization of chemosensitive neurones may play an important role in chemoreception, not simply as a means of sampling the stimulus but also as a way of compartmentalizing the effects of pH in relation to other aspects of a neurone's activity.

Synchronized rhythms in chemosensitive neurons of the locus coeruleus in the absence of chemical synaptic transmission.

The activity of locus coeruleus (LC) neurons was examined in the en bloc isolated brainstem-spinal cord of the neonatal rat using paired whole cell or whole cell plus extracellular recording. In artificial cerebrospinal fluid (ACSF) LC neurons were synchronized by their respiratory innervation and in some neurons showing tonic or burst patterns of discharge these patterns of discharge could also be synchronized. Replacing ACSF with low Ca(2+)-high Mg(2+) generated synchronized rhythmic bursts which remained synchronized at high CO(2) (up to 20%). This rhythm was suppressed by TTX. Substitution of Ba(2+) for Ca(2+) in ACSF generated a synchronized rhythm which was TTX-insensitive. The frequency of this rhythm increased by 31+/-16% on raising CO(2) concentration from 2 to 10%. We conclude that the capacity of chemosensitive LC neurons to generate a synchronized rhythm depends on their electrical coupling, but not on chemical synaptic transmission.

Mammalian brainstem chemosensitive neurones: linking them to respiration in vitro.

Neurones which are excited by CO2 or H+ are present in a number of brainstem structures in addition to the ventrolateral region of the medulla, the site at which the respiratory response to hypercapnia is traditionally believed to originate. In this review we examine recent work concerned with establishing the relationship between these chemosensitive neurones and respiration, the emphasis being placed on the use for this purpose of in vitro preparations of the mammalian brainstem.

Purification of native enolase from medically important Candida species.

The 48 kDa glycolytic enzyme, enolase, has been identified as an immunodominant antigen in Candida albicans infections. It has also been identified as an important fungal allergen. Enolase from a number of medically important Candida species has been purified using a two-step anion- and cation-exchange chromatography method that was preceded by an organic extraction. The enolases purified by this method have a high specific activity and the procedure is 40% efficient, with an average of 5 mg of enolase/g of Candida cells. The purification of native enolase from medically important Candida species will enable the immunological significance and interspecies relationships of this major fungal antigen to be investigated.

'Small group' rehabilitation in adolescent cochlear implant users: learning experiences.

The reasons for which a group approach has been chosen for the small group rehabilitation of adolescent cochlear implant users are discussed. The most significant learning experiences after 18 months of treatment were the socialization of experience, the socialization of individual learning processes, the direct relationship between adolescents, practice discussion of topics of common interest, emphasizing of personal opinions and beliefs, experiencing collective 'products', the reinforcement of interpersonal relationships and the emphasizing of individual initiatives both at home and at school.

Locus coeruleus neurones in vitro: pH-sensitive oscillations of membrane potential in an electrically coupled network.

The response to hypercapnic acidosis (2-8% CO2, bath pH 7.8-7.2) was examined in whole cell recordings from neonatal (P1 to P5) rat Locus coeruleus (LC) neurones in the in vitro brainstem-spinal cord preparation exposed to low Ca2+ (0.2 mM)-high Mg2+ (5 mM). This medium suppressed chemical synaptic transmission and resulted in a pattern of subthreshold oscillations of membrane potential and rhythmic burst discharge which was synchronized throughout the network. The oscillation was suppressed, and the discharge of individual neurones desynchronized, by the gap junction uncoupler, carbenoxolone, indicating that in low Ca2+-high Mg2+ LC neurones form an electrically coupled network. Switching from 2 to 8% CO2 decreased the oscillation amplitude and increased its frequency. The oscillation was suppressed by external Cd2+ and by TTX. but persisted during injection into the cell soma of QX-314. We conclude that in LC neurones acidosis increases the frequency of a Ca2+- and Na+-dependent dendritic oscillator which is synchronized by gap junction coupling throughout the network. This coupling is retained during acidosis.

Respiration-modulated membrane potential and chemosensitivity of locus coeruleus neurones in the in vitro brainstem-spinal cord of the neonatal rat.

1. The activity of locus coeruleus (LC) neurones (n = 126) was examined in whole-cell (conventional and amphotericin B-perforated patch) recordings, and the relationship of this activity to the respiratory discharge recorded on the C4 or C5 phrenic nerve roots was determined at different CO2 concentrations (2 and 8 %; bath pH 7. 8 and 7.2) in the in vitro brainstem-spinal cord preparation of the neonatal rat (1-5 days old). 2. In most neurones (n = 105) ongoing activity was modulated at respiratory frequency. Typically, this consisted of a phase of depolarization and increased discharge frequency synchronous with the phrenic burst, followed by a phase of hyperpolarization and inhibition of discharge (n = 94 of 105). The incidence of respiratory modulation decreased from 91 % on P1 to 57 % on P5. 3. Bath application of the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 5 microM) or the NMDA receptor antagonist DL-2-amino-5-phosphonovaleric acid (APV; 100 microM) abolished both phases of respiratory modulation. The hyperpolarizing phase alone was abolished by the adrenoceptor antagonists idazoxan (5 microM) or phentolamine (0.8 microM). These results indicate that excitatory amino acid pathways are involved in the transmission of both the excitatory and inhibitory components and that the latter involves in addition an alpha2-adrenoceptor-mediated pathway. 4. Increasing the CO2 concentration from 2 to 8 % resulted in a shortening of expiratory duration and weakening or loss of respiratory-phased inhibition; this was accompanied by depolarization, increased discharge frequency and, in those neurones where they were initially present (60 %), an increase in the frequency of subthreshold membrane potential oscillations. The depolarizing response was retained in the presence of tetrodotoxin (TTX, 0.2-1.0 microM). 5. These results indicate that in this neonatal preparation LC neurones form part of the synaptically connected brainstem respiratory network, and that the LC constitutes a site of CO2- or pH-dependent chemoreception.

A comparison of the effects of strength and aerobic exercise training on exercise capacity and lipids after coronary artery bypass surgery.

BACKGROUND: Coronary artery surgery improves symptoms and prognosis in patients with angina. Aerobic exercise rehabilitation improves exercise capacity and prognosis in cardiac patients. Strength exercise training has not been extensively studied. DESIGN: We studied the effects of 6 months aerobic and strength exercise training after coronary artery surgery in 81 men, mean age 57 years. RESULTS: Treadmill time(s) increased by 130.3 (95% confidence interval 46.4 to 214.2) in the aerobic group; by 83.1 (0.9 to 165.3) in the strength group, and by 34.3 (-1 to 69.6) in the control group (P = 0.04, control versus aerobic) after 3 months; and by 196.4 (112.2 to 280.7) in the aerobic group, by 122.7 (37.7 to 207.6) in the strength group and by 27 (-40.4 to 94.4) in the control group (P = 0.002, control versus aerobic, and P = 0.03 control versus strength) after 6 months. The level of fitness improved more in the strength-trained group, and there was a minor reduction in body weight and degree of fatness. There were no changes in lipoprotein levels. Aerobic exercise training causes early and sustained benefit in treadmill exercise capacity, while the effects of strength exercise training are later in onset. Exercise training alone did not influence lipid levels. CONCLUSION: Cardiac rehabilitation programmes should be comprehensive, including advice on diet and other risk factor modifications in addition to exercise sessions involving aerobic and strength training elements.

Chemosensitive medullary neurones in the brainstem--spinal cord preparation of the neonatal rat.

1. Using the isolated medulla and spinal cord of the neonatal rat, the response to CO2-induced changes in superfusate pH was examined in whole cell and perforated patch recordings from ventral medullary neurones which were identified by injection of Lucifer Yellow. The respiratory response to changing the CO2 concentration (from 2 to 8%) consisted of an increase in phrenic burst frequency, which could be accompanied by an increase, decrease or no change in burst amplitude. 2. Five classes of neurone - inspiratory, post-inspiratory, expiratory, respiration-modulated and ionic - were distinguished on the basis of their membrane potential and discharge patterns. Almost all (112 of 123) responded rapidly to 8% CO2 with a sustained change in membrane potential. Depolarizing responses (3-18 mV) occurred in inspiratory, respiration-modulated and 45% of tonic neurones. Hyperpolarizing responses (2-19 mV) occurred in expiratory and post-inspiratory neurones. The remaining tonic neurones were inhibited or showed no response. 3. In representatives of each class of neurone, membrane potential responses to 8% CO2 were retained when tested in the presence of tetrodotoxin (n = 7), low (0.2 mM) Ca(2+)-high (5 mM) Mg2+ (n = 23) or Cd2+ (0.2 mM) (n = 3)-containing superfusate, implying that they are mediated by intrinsic membrane or cellular mechanisms. 4. Neurones were distributed between 1200 microns rostral and 400 microns caudal to obex, and their cell bodies were located between 50 and 700 microns below the ventral surface (n = 104). Almost all responsive neurones (n = 78) showed dendritic projections to within 50 microns of the surface. 6. These experiments indicate that significant numbers of ventral medullary neurones, including respiratory neurones, are intrinsically chemosensitive. The consistency with which these neurones show surface dendritic projections suggests that this sensitivity may arise in part at this level.

Relationship between ENT specialists and deaf community.

The relationship between the ENT specialist and the Deaf Community is discussed along with the relative role of the non-medical consultants who come into contact with this group of people. Suggestions are made to the clinician for a correct approach to deaf persons: acquisition of adeguate tools for communication and clear and understandable information. In this communication and clear and understandable information. In this context, the advent of Cochlear Implants and their impact on the Deaf Community are taken into consideration.