Aminoglycoside-induced sensorineural hearing loss in pediatric cystic fibrosis patients: A retrospective cohort study

Background

Pulmonary infections by gram-negative organisms are important in cystic fibrosis (CF). Aminoglycosides (AG) are often part of the treatment regimen. However, they are a well-known cause of ototoxicity. Even minimal hearing impairment in children could have a future impact on functional well-being.We aimed to investigate the progression of sensorineural hearing loss (SNHL) over several years in pediatric CF patients, and to identify risk factors, such as the use of AG, including both intravenous (IV) and inhaled AG.

Methods

Retrospective analyses of patient records from children and adolescents followed up at the CF clinic of the Antwerp University Hospital, Belgium, were performed. We collected data on age, sex, pure-tone audiometry, and the use of AG. Descriptive and binary logistic regression analyses, and if indicated generalized estimating equations (GEE) analyses were performed.

Results

Forty pediatric patients were enrolled in the study taking part from 2013 to 2020. Pure-tone audiometry revealed an important rate of SNHL over several years, with a prevalence of 29 % for high-frequency SNHL (i.e. 8 kHz). Increasing age was identified as a significant risk factor for the development of SNHL at 8 kHz if 5 or more IV AG courses (p = 0.01) were reported or when IV AG were combined with inhaled AG (p = 0.002).

Conclusions

Age combined with the use of IV AG (≥5 courses or in combination with inhaled AG) are predictive for developing high-frequency SNHL (i.e. 8 kHz). We suggest routine annual hearing screening (incl. high-frequency thresholds) in CF patients, starting from childhood.

Hippo signaling instructs ectopic but not normal organ growth

The Hippo signaling pathway is widely considered a master regulator of organ growth because of the prominent overgrowth phenotypes caused by experimental manipulation of its activity. Contrary to this model, we show here that removing Hippo transcriptional output did not impair the ability of the mouse liver and Drosophila eyes to grow to their normal size. Moreover, the transcriptional activity of the Hippo pathway effectors Yap/Taz/Yki did not correlate with cell proliferation, and hyperactivation of these effectors induced gene expression programs that did not recapitulate normal development. Concordantly, a functional screen in Drosophila identified several Hippo pathway target genes that were required for ectopic overgrowth but not normal growth. Thus, Hippo signaling does not instruct normal growth, and the Hippo-induced overgrowth phenotypes are caused by the activation of abnormal genetic programs.

Stabilizing survival selection on presenescent expression of a sexual ornament followed by a terminal decline

Senescence is a decrease in functional capacity, increasing mortality rate with age. Sexual signals indicate functional capacity, because costs of ornamentation ensure signal honesty, and are therefore expected to senesce, tracking physiological deterioration and mortality. For sexual traits, mixed associations with age and positive associations with life expectancy have been reported. However, whether these associations are caused by selective disappearance and/or within-individual senescence of sexual signals, respectively, is not known. We previously reported that zebra finches with redder bills had greater life expectancy, based on a single bill colour measurement per individual. We here extend this analysis using longitudinal data and show that this finding is attributable to terminal declines in bill redness in the year before death, with no detectable change in presenescent redness. Additionally, there was a quadratic relationship between presenescent bill colouration and survival: individuals with intermediate bill redness have maximum survival prospects. This may reflect that redder individuals overinvest in colouration and/or associated physiological changes, while below-average bill redness probably reflects poorer phenotypic quality. Together, this pattern suggests that bill colouration is defended against physiological deterioration, because of mate attraction benefits, or that physiological deterioration is not a gradual process, but accelerates sharply prior to death. We discuss these possibilities in the context of the reliability theory of ageing and sexual selection.

Specific medical and surgical treatment for chronic inflammatory diseases in children

Treatment for chronic inflammatory conditions in children should take into account the specific pathophysiological and clinical processes underlying these disorders. These guidelines provide a framework for both the medical and surgical treatment of chronic inflammatory diseases such as otitis media, allergic rhinitis and chronic rhinosinusitis, chronic inflammation of tonsils and adenoids, and laryngitis. In addition, the role of vaccinations and immunomodulatory therapies is discussed. Whenever possible, the evidence levels for specific treatments comply with the Oxford Levels of Evidence.

The effects of long-term noninvasive ventilation in hypercapnic COPD patients: a randomized controlled pilot study

Introduction

Noninvasive ventilation (NIV) is a well-established treatment for acute-on- chronic respiratory failure in hypercapnic COPD patients. Less is known about the effects of a long-term treatment with NIV in hypercapnic COPD patients and about the factors that may predict response in terms of improved oxygenation and lowered CO₂ retention.

Methods

In this study, we randomized 15 patients to a routine pharmacological treatment (n = 5, age 66 [standard deviation ± 6] years, FEV₁ 30.5 [±5.1] %pred, PaO₂ 65 [±6] mmHg, PaCO₂ 52.4 [±6.0] mmHg) or to a routine treatment and NIV (using the Synchrony BiPAP device [Respironics, Inc, Murrsville, PA]) (n = 10, age 65 [±7] years, FEV₁ 29.5 [±9.0] %pred, PaO₂ 59 [±13] mmHg, PaCO₂ 55.4 [±7.7] mmHg) for 6 months. We looked at arterial blood gasses, lung function parameters and performed a low-dose computed tomography of the thorax, which was later used for segmentation (providing lobe and airway volumes, iVlobe and iVaw) and post-processing with computer methods (providing airway resistance, iRaw) giving overall a functional image of the separate airways and lobes.

Results

In both groups there was a nonsignificant change in FEV₁ (NIV group 29.5 [9.0] to 38.5 [14.6] %pred, control group 30.5 [5.1] to 36.8 [8.7] mmHg). PaCO₂ dropped significantly only in the NIV group (NIV: 55.4 [7.7] → 44.5 [4.70], P = 0.0076; control: 52.4 [6.0] → 47.6 [8.2], NS). Patients actively treated with NIV developed a more inhomogeneous redistribution of mass flow than control patients. Subsequent analysis indicated that in NIV-treated patients that improve their blood gases, mass flow was also redistributed towards areas with higher vessel density and less emphysema, indicating that flow was redistributed towards areas with better perfusion. There was a highly significant correlation between the % increase in mass flow towards lobes with a blood vessel density of >9% and the increase in PaO₂. Improved ventilation–perfusion match and recruitment of previously occluded small airways can explain the improvement in blood gases.

Conclusion

We can conclude that in hypercapnic COPD patients treated with long-term NIV over 6 months, a mass flow redistribution occurs, providing a better ventilation–perfusion match and hence better blood gases and lung function. Control patients improve homogeneously in iVaw and iRaw, without improvement in gas exchange since there is no improved ventilation/perfusion ratio or increased alveolar ventilation. These differences in response can be detected through functional imaging, which gives a more detailed report on regional lung volumes and resistances than classical lung function tests do. Possibly only patients with localized small airway disease are good candidates for long-term NIV treatment. To confirm this and to see if better arterial blood gases also lead to better health related quality of life and longer survival, we have to study a larger population.

Telomere shortening and survival in free-living corvids

Evidence accumulates that telomere shortening reflects lifestyle and predicts remaining lifespan, but little is known of telomere dynamics and their relation to survival under natural conditions. We present longitudinal telomere data in free-living jackdaws (Corvus monedula) and test hypotheses on telomere shortening and survival. Telomeres in erythrocytes were measured using pulsed-field gel electrophoresis. Telomere shortening rates within individuals were twice as high as the population level slope, demonstrating that individuals with short telomeres are less likely to survive. Further analysis showed that shortening rate in particular predicted survival, because telomere shortening was much accelerated during a bird's last year in the colony. Telomere shortening was also faster early in life, even after growth was completed. It was previously shown that the lengths of the shortest telomeres best predict cellular senescence, suggesting that shorter telomeres should be better protected. We test the latter hypothesis and show that, within individuals, long telomeres shorten faster than short telomeres in adults and nestlings, a result not previously shown in vivo. Moreover, survival selection in adults was most conspicuous on relatively long telomeres. In conclusion, our longitudinal data indicate that the shortening rate of long telomeres may be a measure of 'life stress' and hence holds promise as a biomarker of remaining lifespan.

Great tits growing old: selective disappearance and the partitioning of senescence to stages within the breeding cycle

Deterioration of reproductive traits with age is observed in an increasing number of species. Although such deterioration is often attributed to reproductive senescence, a within-individual decline in reproductive success with age, few studies on wild animals have focused on direct fitness measures while accounting for selective disappearance and terminal effects, and to our knowledge none have determined how senescence effects arise from underlying reproductive traits. We show for female great tits that such an approach helps understanding of the onset, impact and architecture of senescence. Cross-sectional analysis of 49 years of breeding data shows annual recruit production to decline from 3.5 years of age, this decline affecting 9 per cent of females each year. Longitudinal analyses, however, show that selective disappearance of poor-quality breeders partly masks senescence, which in fact starts at 2.8 years and affects 21 per cent of females each year. There is no evidence for abrupt terminal effects. Analyses of underlying traits show no deterioration in clutch size, but significant declines in brood size and fledgling number. Furthermore, these traits contribute -9, 12 and 39 per cent to the senescent decline in recruit production, respectively. Besides providing detailed knowledge of the patterns and architecture of senescence in a natural population, these results illustrate the importance of modelling individual variation, and facilitate study of the underlying mechanisms of senescence.

Post-natal exposure to corticosterone affects standard metabolic rate in the zebra finch (Taeniopygia guttata)

Post-natal stress has been shown to have important short and long term effects on many adult traits in birds. During stress, metabolic alterations often result in the mobilization of energy away from energy-sensitive functions such as growth, which could have significant implications for developing animals. However, little is known about the implications of stress hormones for energy consumption in growing individuals. We experimentally increased corticosterone (CORT) levels in nestling zebra finches via oral administration, between the ages of 7 and 18 days. The standard metabolic rate (SMR) of birds was measured twice overnight when birds were between 11-13 and 55-65 days of age. Developmental CORT administration significantly elevated overnight variability in SMR (sd) in nestling birds (during the treatment period), but not at 55-65 days (5-6 weeks after the treatment period). The effect on variability was seen more prominently in birds from larger brood sizes and in females. We found no effects of our treatments on mean SMR overnight. However, brood size and sex had interactive effects, with males from larger brood sizes having higher SMR at 55-65 days of age. These results suggest that stress hormones can have significant effects on energy metabolism and possibly nocturnal arousal and sleep fragmentation. However, there were no detectable long term effects of our treatments on SMR, suggesting that these effects are only short-lived, in order to maintain homeostasis in the short term.

Delayed behavioral effects of postnatal exposure to corticosterone in the zebra finch (Taeniopygia guttata)

Early developmental conditions can significantly influence the growth and survival of many animal species. We studied the consequences of exposure to corticosterone (CORT), a stress hormone, during the nestling stage on two behavioral traits (neophobia, social dominance) measured when the birds had reached independence. Nestling zebra finches (Taeniopygia guttata) were exposed twice daily to exogenous CORT via oral administration for a 12-day period up until fledging. Experimental CORT administration depressed nestling growth rates, confirming results previously obtained in this species. Our data on neophobic behavior revealed a significant interaction between sex and treatment, with CORT-dosed males showing reduced latencies to approach a novel object, while there was little effect of corticosterone treatment on female neophobia. There was no significant effect of age (30 or 50 days), however, there was a non-significant trend towards an interaction between treatment and age, with neophobia increasing with age in the CORT-dosed birds, but decreasing in controls. At 50 days of age previous exposure to corticosterone resulted in reduced success in competitions for a non-food-based resource (a perch) in both sexes. There were no effects of brood size on any behavioral traits measured here, but this may be due to the small range in brood size used. Our results show that elevated levels of stress hormones during postnatal development can have significant effects on important behavioral traits, i.e., neophobia and dominance. Moreover, they confirm the importance of rearing conditions in shaping adult phenotypes.

Correlation between severity of sleep apnea and upper airway morphology based on advanced anatomical and functional imaging

Determination of the apnea hypopnea index (AHI) as a measure of the severity of obstructive sleep apnea/hypopnea syndrome (OSAHS) is a widely accepted methodology. However, the outcome of such a determination depends on the method used, is time consuming and insufficient for prediction of the effect of all treatment modalities. For these reasons more methods for evaluating the severity of OSAHS, based on different imaging modalities, have been looked into and recent studies have shown that anatomical properties determined from three-dimensional (3D) computed tomography (CT) images are good markers for the severity of the OSAHS. Therefore, we correlated anatomical measurements of a 3D reconstruction of the upper airway together with flow simulation results with the severity of OSAHS in order to find a combination of variables to indicate the severity of OSAHS in patients. The AHI of 20 non-selected, consecutive patients has been determined during a polysomnography. All patients also underwent a CT scan from which a 3D model of the upper airway geometry was reconstructed. This 3D model was used to evaluate the anatomical properties of the upper airway in OSAHS patients as well as to perform computational fluid dynamics (CFD) computations to evaluate the airflow and resistance of this upper airway. It has been shown that a combination of the smallest cross-sectional area and the resistance together with the body mass index (BMI) form a set of markers that predict very well the severity of OSAHS in patients within this study. We believe that these markers can be used to evaluate the outcome of an OSAHS treatment.

Age-dependent traits: a new statistical model to separate within- and between-individual effects

Evolutionary questions regarding aging address patterns of within-individual change in traits during a lifetime. However, most studies report associations between age and, for example, reproduction based on cross-sectional comparisons, which may be confounded with progressive changes in phenotypic population composition. Unbiased estimation of patterns of age-dependent reproduction (or other traits) requires disentanglement of within-individual change (improvement, senescence) and between-individual change (selective appearance and disappearance). We introduce a new statistical model that allows patterns of variance and covariance to differ between levels of aggregation. Our approach is simpler than alternative methods and can quantify the relative contributions of within- and between-individual changes in one framework. We illustrate our model using data on a long-lived bird species, the oystercatcher (Haematopus ostralegus). We show that for different reproductive traits (timing of breeding and egg size), either within-individual improvement or selective appearance can result in a positive association between age and reproductive traits at the population level. Potential applications of our methodology are manifold because within- and between-individual patterns are likely to differ in many biological situations.

Comparison of the cost of short flights in a nectarivorous and a non-nectarivorous bird

Although most birds are accustomed to making short flights, particularly during foraging, the flight patterns during these short periods of activity differ between species. Nectarivorous birds, in particular, often spend time hovering, while non-nectarivorous birds do not. The cost of short flights is likely therefore to differ between nectarivorous and non-nectarivorous birds because of the different energetic contributions of different flight types to the behaviour. The 13C-labelled bicarbonate technique was used to measure the energy cost of short flights in the nectarivorous Palestine sunbird Nectarinia osea (mean mass 6.17+/-0.16 g, N=8) and the non-nectarivorous starling Sturnus vulgaris (mean mass 70.11+/-1.11 g, N=9). The technique was initially calibrated in five individuals for each species at temperatures ranging from 1 to 35 degrees C, by comparing the isotope elimination rate to the metabolic rate measured simultaneously by indirect calorimetry. The cost for short intermittent flight was then measured by encouraging birds to fly between two perches at either end of a narrow corridor (perch distance for sunbirds, 6 m; for starlings, 5 m), and measuring the amount of isotope eliminated during the flight. The isotope elimination rate was interpolated onto the calibration equation to predict flight cost, as a direct calibration could not be performed during flight. Mean energy expenditure during flight was 1.64+/-0.32 W in sunbirds, while in starlings the flight costs averaged 20.6+/-0.78 W. Energy cost of flight relative to basal metabolic rate was substantially greater in the starling than the sunbird. Phylogenetic analysis of different modes of flight in these and additional species suggests that differences in flight behaviour may cause these elevated costs in slow flying non-nectarivores such as starlings, compared to birds that are more prone to short intermittent flights like the sunbirds.

Growth of heterotopic LNCaP prostate cancer tumor in nude mice is not affected by dietary calcium

BACKGROUND

We attempted to provide experimental evidence linking increased dietary calcium to progression of prostate cancer, as suggested by some epidemiological studies, using a heterotopic prostate cancer nude mice model.

METHODS

Twenty heterotopic LNCaP prostate cancer tumor bearing nude mice were randomly assigned to one of the four groups: (I) high fat/low calcium diet, (II) high fat and high calcium diet, (III) high fat diet fortified with Vitamin D3, and (IV) high fat and high calcium diet fortified with Vitamin D3. In addition to weekly animal weights and tumor size measurements, the serum prostate specific antigen (PSA), 25-hydroxy Vitamin D3, calcium, phosphorus, total protein, albumin (to account for bound calcium) [1], and serum alkaline phosphatase (a measure of bone loss) [2] were determined at the termination of experiments.

RESULTS

Although the serum calcium and 25-hydroxy Vitamin D3 were significantly higher in groups III and IV compared to groups I and II (P < 0.05), there was no significant difference between the tumor growth rates, final tumor weights (P = 0.9), and the serum PSA levels (P = 0.94) between the four groups.

CONCLUSIONS

The results suggest that dietary calcium does not significantly affect the growth of heterotopic LNCaP prostate cancer in nude mice.

Delayed effects of pyridostigmine and exercise training on acetylcholinesterase and muscle tension in mouse lower extremity

In this study, the interactive effects of pyridostigmine, a pretreatment drug against nerve agents, and exercise training on muscle tension were investigated in the mouse lower extremity anterior muscular compartment by dorsiflexion of the foot with stimulation of the peroneal nerve. Acetylcholinesterase (AChE), lipid peroxidation (in terms of the end-product malondialdehyde, MDA) and creatine phosphokinase (CPK) activity in the muscle were correlated with muscle tension. Male NIH Swiss mice were divided into four groups and treated as follows: (1) sedentary control; (2) pyridostigmine (1.2 mg/kg orally) daily for the 5th and 6th weeks; (3) exercise training for 10 weeks; and (4) pyridostigmine plus exercise training for 10 weeks. Experiments on muscle tension were conducted 4 weeks after the last dose of pyridostigmine or saline and 24 h after exercise. The muscle tension was measured in right and left legs using a tension transduction device connected to a polygraph. After muscle tension recording, mice were killed, blood and triceps muscle were isolated, and plasma CPK and muscle AChE activities, and MDA were determined. There was a significant increase in the muscle tension (P<0.05) in the group treated with pyridostigmine plus exercise as compared to the control and exercise groups. The pyridostigmine plus exercise group also showed a significant reduction in AChE activity (P<0.01) and enhanced MDA (P<0.05) in the triceps muscle. These results suggest that subchronic dosages of pyridostigmine and interaction with exercise training result in the delayed effects of reduction in muscle AChE activity and enhanced muscle tension.

The management of cubital tunnel syndrome: a meta-analysis of clinical studies

Despite extensive clinical experience in treating cubital tunnel syndrome, optimal surgical management remains controversial. A meta-analysis of 30 studies with accurate preoperative and postoperative staging was undertaken. Patients were staged preoperatively into minimum, moderate, and severe groups on the basis of clinical presentation. Treatment modalities included nonoperative management, surgical decompression, medial epicondylectomy, anterior subcutaneous transposition, and anterior submuscular transposition. Statistical analysis using a standard SAS database with analysis of variance and chi-square tests was used to assess the efficacy of each therapeutic modality. For minimum-staged patients, all modalities produced similar degrees of satisfaction. However, total relief occurred most after medial epicondylectomy and least after anterior subcutaneous transposition. Patients treated nonoperatively had the highest rate of recurrence. For moderate-staged patients, submuscular transposition was most efficacious, whereas patients with nonoperative management fared the worst. Finally, for severe-staged patients, current therapeutic modalities were not consistently effective, with medial epicondylectomy producing the poorest operative result. This article reveals statistically significant differences in outcomes among therapeutic modalities, which may assist in treatment planning; it introduces standardized methods to aid in determining, analyzing, and communicating treatment outcomes.

Latitudinal variation in parental energy expenditure during brood rearing in the great tit

The variation in time and energy allocation of female great tits, Parus major, was studied in five different European populations across a latitudinal gradient. Daily energy expenditure (DEE) was measured in females tending 12-day-old broods. The number of daylight hours used by the parents to collect food for the brood increased with latitude, while DEE and feeding rate per brood tended to level off with latitude. Individual variation in DEE could be explained by variation in ambient temperature (-), the duration of activity period (+) and area, but not by brood size, female body mass, brood mass or feeding rate. When the effect of ambient temperature and the duration of the activity period on the day of energy expenditure measurements were controlled for, female DEE still tended to level off with latitude. Temperature and activity alone can thus not explain the observed pattern. The present study suggests that parents at southern latitudes may be under a time constraint and do not increase energy expenditure because they have no more daylight hours available for foraging, while birds at northern latitudes may be under an energy constraint because they do not make full use of the long daylight period available.

A tradeoff between immunocompetence and sexual ornamentation in domestic fowl

Females often select their mates on the basis of the size or intensity of sexual ornaments, and it is thought that such traits are reliable indicators of male quality because the costliness of these traits prevents cheating. The immunocompetence handicap hypothesis is a recently proposed mechanistic explanation of these costs and states that males carry ornaments at the expense of their resistance to disease and parasites. The tradeoff between immunocompetence and sexual ornamentation was hypothesized to arise as a consequence of the dual effect of androgens on ornamentation (+) and immune function (-). To test this hypothesis, we compared comb size between male domestic chickens Gallus domesticus of lines divergently selected for antibody responses to sheep erythrocytes (three lines: selected for low response or high response and a control line). The importance of comb size in inter- and intrasexual selection is well established, and comb size is strongly dependent on testosterone level. Comb size was larger in the males of the low line than in the high line, and comb size of control males was intermediate, indicating a tradeoff between ornamentation and immunocompetence. Testosterone (T) levels varied in a similar fashion (TLow > TControl > THigh), suggesting that this hormone could mediate the tradeoff between ornamentation and immunocompetence. These results support the idea that a tradeoff with immune function may constrain the expression of secondary sexual ornaments.

Estimating organ size in small migrating shorebirds with ultrasonography: An intercalibration exercise

Organs, even of fully grown adult birds, mammals, and reptiles, may show substantial size changes in relation to specific performances. These changes are difficult to study, because measurements usually can only be obtained following the death of the animal. We explored the use of ultrasonographic imaging, a relatively simple noninvasive technique, to measure size of pectoral muscles and stomach in two small shorebird species (red knots Calidris canutus and golden plovers Pluvialis apricaria). Accuracy of ultrasound measurements in estimating organ mass in red knots was reasonably high. Depending on the equipment used, the error of individual measurements was 20%-25% for the pectoral muscles and 26%-44% for the stomach. In plovers the technique was less accurate, probably because of the low variability of the organs involved. Ultrasound scanning is particularly suited to measure rapidly changing organ sizes over short time intervals. We demonstrate this with an example in which changes in individuals in size of pectoral muscle and stomach were monitored in captive red knots following a change in diet. Ultrasound measures will enable studies on the links between body composition and future behavior and physiology.

Scotopic vision in colour-blinds

Alleles causing colour-blindness are present in humans at non-negligible levels, and it is not yet understood how colour-blindness is maintained, since colour-vision probably provides a selective advantage, e.g. when foraging. We show that after dark-adaptation colour-blinds had lower light perception thresholds than colour-normals (0.44 log-units), which may give a selective advantage under scotopic conditions, which may offset the disadvantage that colour-blinds suffer during foraging.

Non-heart-beating cadaver procurement and the work of ethics committees

Recent ethics literature suggests that issues involved in non-heart-beating (NHB) organ procurement are both highly charged and rather urgent. Some fear that NHB is a public relations disaster waiting to happen or that it will create a backlash against organ donation. The purpose of the study described below was to assess ethics committees' current level of involvement in and readiness for addressing the difficult issues that NHB organ retrieval raises—either proactively through policy development or concurrently through ethics consultation.

Discussing organ donations with patients

BACKGROUND

The gap between the demand and supply of organs has prompted examination of health care professionals' roles in organ retrieval. This study examines Illinois family physicians' advisory roles as reflected in their beliefs and conversations with patients about cadaveric organ donation.

METHODS

A 50-item questionnaire was mailed to a random sample of 500 members of the Illinois Academy of Family Physicians. A total of 272 usable surveys were returned.

RESULTS

The majority (67%) of the respondents believe that individuals' wishes to donate should prevail even when patients' families prefer not to donate. Yet, in conversations with patients, most of these physicians recommend only that patients sign driver's license donor cards (81%) and have discussions with family members (57%), methods that do not ensure that individuals' donative wishes will be carried out. Few physicians encourage completion of a health care power of attorney, the method most likely to ensure respect for patient wishes when an individual's desire to donate is specified.

DISCUSSION

Family physicians could more effectively help patients implement their desires to donate if they would become more familiar with and include in their discussions the potential role of health care powers of attorney.

Sleep-disordered breathing and poor functional outcome after stroke

BACKGROUND AND PURPOSE

We objectively evaluated patients with recent stroke to determine the prevalence of sleep-disordered breathing (SDB) and whether SDB was associated with unfavorable clinical outcomes.

METHODS

Forty-seven patients with recent ischemic stroke (median, 13 days) were studied with computerized overnight oximetry for evidence of arterial oxyhemoglobin desaturation (SaO2). Polysomnography was also performed on 19 patients. Medical history, sleep history, location of stroke, and severity of neurological deficit were recorded, and patients were observed by staff for evidence of snoring and excessive daytime sleepiness. Functional abilities were measured with the use of the Barthel Index (BI). Outcome variables included ability to return home at discharge, continued residence at home at 3 and 12 months, BI at discharge, BI at 3 and 12 months, and death from any cause at 12 months.

RESULTS

Mean SaO2 during oximetry was 94.0 +/- 1.7%, and percentage of recording time spent at < 90% SaO2 was 4.3 +/- 5.7%. The number of desaturation events per hour of recording time (desaturation index [DI]) was 9.5 +/- 9.67, with 15 of 47 (32%) having DI > 10 and 6 of 47 (13%) having DI > 20. Oximetry measures of SDB correlated with lower BI scores at discharge and lower BI at 3- and 12-month follow-ups (P < or = .05, Pearson coefficients). Oximetry measures correlated with return home after discharge, but the association between oximetry measures and living at home was lost at 12 months. Two oximetry variables correlated with death at 1 year. Brain stem location correlated with higher DI and time at < 90% SaO2, but patients with hemispheric stroke and oximetry abnormalities also had worse functional outcome. No correlation was found between oximetry values and sex, age, preexisting medical conditions (except previous stroke), or severity of neurological deficit. Oximetry abnormalities were associated with a history of snoring. Polysomnography on 19 patients confirmed oximetry evidence of severe SDB. Eighteen of 19 patients (95%) had an apnea-hypopnea index (AHI) of > 10 events per hour of recording, 13 of 19 (68%) had an AHI > 20, and 10 of 19 (53%) had an AHI > 30. Desaturation events were largely due to obstructive apneas.

CONCLUSIONS

SDB accompanied by arterial oxyhemoglobin desaturation is common in patients undergoing rehabilitation after stroke and is associated with higher mortality at 1 year and lower BI scores at discharge and at 3 and 12 months after stroke. SDB may be an independent predictor of worse functional outcome. Obstructive sleep apnea appeared to be the most common form of SDB, and the frequent history of snoring suggests that SDB preceded the stroke in most patients.

5-fluoronicotine, noranhydroecgonine, and pyridyl-methylpyrrolidine release acetylcholine and biogenic amines in rat cortex in vivo

The effects of nicotinic receptor agonists 5-fluoronicotine, noranhydroecgonine and pyridyl-methylpyrrolidine on the cortical release of acetylcholine (ACh), norepinephrine (NE), dopamine (DA) and serotonin (5-HT) were investigated with microdialysis in rat. 5-Fluoronicotine significantly elevated ACh to 76% above basal values and DA to 69% above baseline. Pyridyl-methylpyrrolidine significantly increased the release of ACh to 39% above basal values and NE to 63% above baseline. Noranhydroecgonine significantly elevated NE to 64% above basal values and DA to 147% above baseline. 5-Fluoronicotine did not affect NE release; pyridylmethylpyrrolidine did not alter DA release; and noranhydroecgonine did not significantly elevate ACh release. None of these agonists increased the release of 5-HT. All responses were blocked by prior administration of mecamylamine, a nicotinic receptor antagonist. The distinctive neurotransmitter-related profiles for the three agonists are suggestive of activity at subtypes of nicotinic receptors, an effect that may be related to the structural diversity of these compounds.

Levator aponeurosis dehiscence in a patient treated with botulinum toxin for blepharospasms and eyelid apraxia

A 63 years old woman presented with bilateral blepharospasms and eyelid apraxia which was treated with Botulinum toxin injections. A post-treatment ptosis was seen with preserved levator function. It was then suggested that manual eyelid traction could have caused aponeurotic dehiscence of the levator muscles. Surgical exploration confirmed this diagnosis. One must be aware that eyelid apraxia can mask an aponeurotic dehiscence of the levator muscle induced by chronic manual traction exerted on the apractic eyelids.

Prevention of neonatal macrosomia in gestational diabetes by the use of intensive dietary therapy and home glucose monitoring

This study was undertaken to determine if intensive dietary therapy, home blood glucose monitoring, and the selective use of insulin can be effective in preventing fetal macrosomia. All patients were screened at 24 to 28 weeks' gestation using a modification of O'Sullivan's criteria. The 153 patients diagnosed as gestational diabetics by the study protocol were placed on a 1800 to 2000 Kcal American Diabetes Association diet and taught home glucose monitoring. Insulin therapy was initiated only if blood glucose control was inadequate. There were no significant differences (p greater than 0.05) between the study and reference populations in regard to mean birthweight or the incidence of macrosomia. Since our study criteria for diagnosing gestational diabetes were slightly different from those of the National Diabetes Data Group (NDDG), data from 99 patients meeting the NDDG criteria were analyzed in a similar manner. No significant differences were found between this subgroup and the reference population. Since only 7.2% of our study patients required insulin, we conclude that the incidence of fetal macrosomia in gestational diabetes can be kept equal to that of the general population by a program of intensive dietary therapy and home glucose monitoring, with insulin being used only therapeutically, not prophylactically.