Communication development in children who receive a cochlear implant by 12 months of age

OBJECTIVE

Describe the long-term benefits of early cochlear implantation. Provide a comprehensive description of outcomes, including: language, speech production, and speech perception. Compare the communication outcomes for the early implanted children to those of normally hearing children and children who received a cochlear implant at a comparatively older age.

METHOD

Retrospective review of the communication development of 35 children implanted between 6 and 12 months of age and 85 children implanted between 13 and 24 months of age. Audiologic assessments included unaided and aided audiograms, auditory brainstem response (ABR), auditory steady state response (ASSR), and otoacoustic emissons (OAEs). Formal language, speech production, and speech perception measures were administered, preimplant and at 1, 2, 3, and 5 years postimplant.

RESULTS

The children who received their cochlear implant by 12 months of age demonstrated language growth rates equivalent to their normally hearing peers and achieved age appropriate receptive language scores 3 years postimplant. The children who received their cochlear implant between 13 and 24 months demonstrated a significant language delay at 3 years postimplant. Speech production development followed a similar pattern to that of normal-hearing children, although was delayed, for both groups of children. Mean open-set speech perception scores were comparable with previous reports for children and adults who use cochlear implants.

CONCLUSION

Children implanted by 12 months of age demonstrate better language development compared with children who receive their cochlear implant between 13 and 24 months. This supports the provision of a cochlear implant within the first year of life to enhance the likelihood that a child with severe-to-profound hearing impairment will commence elementary school with age-appropriate language skills.

Cochlear Implant Outcomes in Adults and Children with Inner Ear Malformations

Objectives:

Bony cochlear or vestibular malformations occur in approximately 20% of patients with congenital hearing loss, but their impact on audiologic outcomes is not entirely clear. Our objective was to assess the impact of inner ear malformations on surgical and audiologic outcomes in cochlear implantation (CI).

Methods:

A retrospective review of a single CI clinic identified a cohort of 57 children and 31 adults with inner ear malformations who had undergone CI between 1994 and 2010. Patients were classified into: common cavity, incomplete partition -I (IP-I); IP-II with or without enlarged vestibular aqueduct (EVA); IP-III, or EVA alone. We compared speech perception language development and surgical outcomes between the groups.

Results:

The type of malformation was not associated with CI performance in either adults or children. In children, the duration of profound hearing loss was correlated with scores for: open-set phoneme (r = -0.43, P = 0.004); open-set word (OSW) (r =-0.32, P = 0.03); Bench Kowal Bamford sentence (BKB) (r =-0.35, P = 0.02), and Peabody Picture Vocabulary Test delay (r = 0.49, P = 0.001). In adults, the duration of profound hearing loss was correlated with OSW (r=-0.36, P = 0.04) and BKB (r =-0.41, P = 0.02).

Conclusions:

The extent of inner ear malformation alone cannot predict CI performance. However, the presence of a gusher, incomplete insertion, and a longer duration of pre-implant hearing loss were associated with worse speech perception and language outcomes in children and adults.

Nursing home residents attending the emergency department: clinical characteristics and outcomes

Nursing home (NH) residents represent the frailest group of older people, and providing gerontologically attuned care that addresses these frailties is often a challenge within the emergency department (ED). This study sought to prospectively profile acutely unwell NH residents in order to clarify some of the challenges of providing emergency care to this group. Over an 18-week period, we prospectively reviewed all NH residents presenting to the ED of an urban university teaching hospital. Relevant data were retrieved by direct physician review (as part of a comprehensive geriatric assessment in the ED), collateral history from NH staff and primary carers, and review of electronic records. There were 155 ED visits by 116 NH residents. Their mean age was 80.3 (±9.6) years. High pre-morbid levels of dependency were reflected by a mean Barthel Index of 34.1 (±20) and almost two-thirds had a pre-existing diagnosis of dementia. One-third of visits were during 'normal' working hours. Patients were reviewed by their regular NH doctor pre-transfer for 36% of visits. Using accepted international criteria, over half of the visits were deemed 'potentially preventable'. Unwell NH residents have complex medical needs. The decision to refer these patients to the ED is often made by 'out of hours' general practitioners and their initial care in the ED is directed by physicians with limited experience in geriatric medicine. Most referrals to the ED are potentially preventable but this would require enhancements to the package of care available in NHs.

Transmastoid repair of superior semicircular canal dehiscence

Objective/Hypothesis Superior semicircular canal (Sup SC) dehiscence syndrome is a rare condition, causing a variety of auditory and vestibular symptoms. The traditional surgical management is a middle cranial fossa, extradural approach to resurface the Sup SC. Recently, a transmastoid approach for plugging of the Sup SC has been developed. We present further data supporting the use of the transmastoid approach in preference to the middle fossa approach. Design This is a retrospective multi-institutional case series. Method We included 10 patients in this case series from two tertiary otology institutions. Sup SC dehiscence was confirmed by correlation of clinical symptoms with positive audiometric, vestibular evoked myogenic potential, and computed tomography findings. A transmastoid approach was used for plugging of the Sup SC. Either a single fenestration was created at the site of dehiscence or separate fenestrations sited ampullopetal and ampullofugal to the dehiscence. Results All patients who underwent this procedure had good symptom control and hearing preservation postoperatively. Conclusion In patients with adequate temporal bone pneumatization, the transmastoid approach provides a safe and effective alternative to the middle cranial fossa approach. This series has demonstrated excellent symptom control and preservation of hearing with the transmastoid approach.

A bioavailability study of two preparations of tamoxifen after single doses

The bioavailability of two different tablet formulations of tamoxifen was studied in twelve healthy male volunteers. Two tablets, each of 10 mg, of both preparations were administered orally at intervals of two weeks in a randomized cross-over design. Samples of blood for tamoxifen measurement were taken for up to 48 h following administration. Tamoxifen was measured by an HPLC method sensitive to 2.0 ng ml(-1). The area under the concentration-time curve was similar for both preparations. The study, therefore, did not demonstrate any differences between the bioavailability of the two preparations of tamoxifen.

Ageism and clinical research

Despite being the most significant consumers of health care resources and medications worldwide, recent international research has highlighted the under-representation of older participants from clinical trials. This creates problems for physicians as the patients seen in clinical practice are not representative of those on which medical treatments and interventions have been trialled, and we need to consider whether results (both negative and positive) from these trials are applicable to these patients. Our aim was to gauge whether exclusion of older people was prevalent in research proposals submitted to Dublin teaching hospitals. We audited all clinical research proposals submitted to the Research Ethics committee (REC) covering the teaching hospitals attached to Trinity College Dublin (TCD) from July 2008 to July 2011 inclusive, recording exclusion of patients based on an arbitrary upper age limit. Of the 226 relevant trials studied, 31(13.7%) excluded participants based solely on an arbitrary upper age limit. 22 (9.8%) of the relevant trials were submitted by geriatricians, none of which excluded patients based solely on age. Over 50% (12 of 22) trials submitted by neurology/psychiatry excluded patients based on an upper age limit. The mean upper age limit used over all trials as a cut-off was 69.2 years of age. As well as this, the majority of the remaining trials also contained other exclusion criteria, especially those based on cognitive function which further limited participation of older people. While we found that a significant proportion of clinical trials submitted to the TCD REC still excluded patients based arbitrarily on an upper age limit, participation rates of older people seem to be higher in this Irish centre than that seen in international trials. Significant room for improvement still remains however and there needs to be a promotion of greater awareness of the need for developing, testing and licensing medicines so that it mirrors the consumer groups in which they will be used. Increased input from geriatricians around the testing and licensing of medicines, and in licensing agencies, would greatly help in this regard. It is both unhelpful for optimal healthcare as well as fundamentally unjust to exclude participants from clinical research based solely on an arbitrary age limit.

Update on long-term results with auditory brainstem implants in NF2 patients

This study reviews the long-term results of auditory brainstem implant (ABI) in neurofibromatosis type 2 (NF2) patients. Retrospective chart reviews of patients who received an ABI at the Melbourne Cochlear Implant Clinic since 1995. Ten patients with an average follow-up of five years were included. Three patients received the N22 ABI and seven received the N24. Two patients discontinued use of their devices. Users reported part-time use for approximately four to five hours per day, switching their implants off in noisy environments. Audiological analyses at one to seven years post-implantation indicate that N24 patients showed worse performance at one year post-implantation but they continued to improve and, in the long term, both N22 and N24 groups achieved similar results. In conclusion, ABI provides a safe and useful tool for aural rehabilitation in NF2 patients. This study confirms that gradual improvement in performance occurs beyond one year post-implantation, as speech perception scores continued to improve.

APSCI panel discussion I: imaging and surgical issues

This is a short overview on imaging techniques in pre-, peri- and postoperative evaluation of cochlear-implant patients. Surgery techniques are described as well as possible complications and how to avoid them.

Otosclerosis

OBJECTIVES

1. To examine whether speech perception after implantation is correlated with the total duration of deafness, the duration of deafness in the implanted ear, or age at implantation. 2. To examine whether the rate of facial nerve stimulation postoperatively is correlated with the type of electrode used.

STUDY DESIGN

Retrospective case note review.

SETTING

Tertiary referral center.

PATIENTS

Fifty-nine adults with profound postlingual sensorineural hearing loss due to otosclerosis.

INTERVENTION

Cochlear implantation with the Nucleus device using either a straight (n = 35) or Contour (n = 29) electrode array.

MAIN OUTCOME MEASURES

Speech perception scores for patients at 3, 6 and 12 months postimplantation were correlated against duration of deafness in the implanted ear, duration of total deafness, and age at implantation. Data on facial nerve stimulation rates postoperatively were collected.

RESULTS

Implantation in the shortest deafened ear conferred an initial advantage for speech perception 3 months after surgery; however, this effect was lost by 6 months. There were no significant correlations between the duration of bilateral deafness and hearing outcomes. Age at implantation was negatively correlated with outcome at 3 months, but not at 6 and 12 months. Fourteen of 35 patients with straight electrodes and 0 of 24 patients with Contour electrodes experienced facial nerve stimulation during mapping sessions (p < 0.005, chi).

CONCLUSION

Patients with otosclerosis are not disadvantaged in the long term by implantation in the longest deafened ear. Increasing age at implantation did not predict poorer outcomes. A perimodiolar design of electrode should be used in otosclerotic patients when possible to reduce the risk of facial nerve stimulation.

Temporal Bone Results and Hearing Preservation with a New Straight Electrode

Due to improved technology, cochlear implant (CI) candidacy has been widened towards patients with usable residual hearing in the low frequency range. These patients might benefit from additional acoustic amplification provided that residual hearing can be preserved with cochlear implantation. To provide a high probability of hearing preservation, a new electrode array was designed and developed at the Medizinische Hochschule Hannover. This 'Hybrid-L' electrode array has 22 electrodes spread over 15 mm with an overall insertion depth of 16 mm. The straight electrode with modiolus facing contacts is designed for a round window insertion. It shall provide the full range of the currently most advanced Nucleus CI system. A temporal bone study demonstrated the favorable insertion characteristics and minimized trauma to intracochlear structures. Compared to standard CI electrodes especially no basilar membrane perforation could be found. So far, 4 patients have been implanted and residual hearing could be preserved. One patient was fitted and showed a marked additional benefit from the electroacoustic stimulation compared to either acoustic or electrical stimulation alone. These results are very encouraging towards a concept of reliable hearing preservation with cochlear implantation.

Paraganglioma: the role of genetic counselling and radiological screening

Paragangliomas are rare tumours of the autonomic nervous system that occur in both sporadic and hereditary forms. They are usually benign tumours with low mortality, but can cause significant morbidity related to mass effect. Genetic predisposition to develop paraganglioma can occur within known tumour syndromes and familial tumours tend to present at a younger age and at multiple sites compared to sporadic tumours. Tumours should be diagnosed and excised as early as possible, as studies have shown morbidity to be directly related to tumour size. We present a case of a 14-year-old boy with multiple paraganglioma and a strong family history of paraganglioma. He suffered significant morbidity at resection of an extra-adrenal retroperitoneal tumour due to late diagnosis and was later unable to undergo excision of a head and neck paraganglioma due to its size and relation to neurovascular structures in the neck. We review the current literature on suggested genetic counselling (psychological counselling and DNA analysis) and radiological screening guidelines and recommend that genetic counselling should be offered to all patients with a family history of paraganglioma from the age of 5 years. Those positive for paternal paraganglioma locus gene should then undergo regular radiological screening with MRI.

Tranquilliser use as a risk factor for falls in hospital patients

This study looked at associations of tranquilliser use and falls risk in a hospital population of confused and nonconfused patients. In a prospective observational study in a rehabilitation hospital for elderly patients, we followed 1025 consecutive patients. The number of fallers, recurrent fallers and total falls was recorded. Confused patients (p < 0.0001) and patients on tranquillisers (p = 0.001) were significantly more likely to fall than nonconfused patients and patients off tranquillisers. Confused patients on tranquillisers were significantly more likely to have recurrent falls (p = 0.026) when compared with confused patients off tranquillisers. The risk was apparent from admission, persisting throughout the first 30 days of stay. This was not noted for nonconfused patients. We identified a stratification of risk for falls with nonsignificant trends for confused and nonconfused patients on tranquillisers to be fallers and to have more falls compared with patients off tranquillisers. These data are associational and do not necessarily imply causality. There is however no evidence to recommend the routine withdrawal of tranquillisers from all patients. Any future research needs to include confused patients.

TEM/AFM investigation of size and surface properties of nanocrystalline ceria

A series of ceria nanoparticles were synthesized by using a microemulsion method. The effect of relative concentration of surfactant/water on the size and the surface roughness of ceria nanoparticles was examined using transmission electron microscopy (TEM) and atomic force microscopy (AFM) respectively. The investigation confirmed a relationship between the size and the roughness properties of the nanoceria as a function of the water to surfactant ratio. With increasing dilution of the surfactant, the size distribution became narrow such that average particle size decreased linearly as the ratio increased without affecting lower size threshold of particles (approximately 10 nm). The surface roughness, on the other hand was found to increase with increasing water to surfactant ratio implying diluted surfactant would provide rougher surface of ceria nanoparticles. The information can be used to tailor the adhesion properties of nanoceria by optimizing the size distribution as well as surface roughness as a function of water to surfactant ratio.

Serum ovalbumin-specific immunoglobulin G responses during pregnancy reflect maternal intake of dietary egg and relate to the development of allergy in early infancy

BACKGROUND

The value of allergen elimination diets during pregnancy for primary prevention of infant allergy has been questioned. However, dietary compliance may influence effectiveness.

OBJECTIVES

To monitor egg intake during a randomized controlled trial of egg avoidance throughout pregnancy and lactation by serial measurements of serum ovalbumin (OVA) IgG concentration in conjunction with dietary diary record and also, to analyse specific IgG concentrations at birth in relation to infant allergic outcome.

METHODS

Pregnant women, with personal or partner atopy, were randomized to complete dietary egg exclusion or an unmodified healthy diet before 20 weeks gestation. The infants were evaluated for atopy at 6 months of age. Serum food-specific IgG concentrations were determined by ELISA in maternal samples collected at study recruitment and during labour, and in infant samples at birth (umbilical cord).

RESULTS

Serum-specific IgG to OVA, but not the unrelated allergen, cow's milk beta-lactoglobulin, decreased over pregnancy in egg-avoiding women only (P<0.001). Cord OVA IgG concentration correlated with maternal IgG at delivery (r=0.944; P<0.001), and for infants born to atopic women, cord concentration was higher than that of their mother's (P<0.001). Infants with the lowest and highest cord IgG concentrations were the least likely, and those with mid-range concentrations were the most likely, to be atopic by 6 months of age (P=0.008).

CONCLUSION

Serum OVA IgG concentration reflects egg consumption, thereby indicating dietary allergen doses to which the developing immune system might be exposed. Trans-placental maternal IgG must be considered among early life factors that regulate infant atopic programming.

The relationship of falls to injury among hospital in-patients

The need to reduce falls is driven by the need to reduce injury. If patients at risk of injury can be distinguished from the patients at risk of falls, there is the potential for a more effective fall risk management policy by targeting injury prevention measures. We conducted a prospective observational study, with blinded endpoint evaluation of 825 consecutive patients admitted to geriatric rehabilitation wards. We identified 150 fallers (18.2%) contributing 243 falls. Fifty-six patients sustained an injury contributing 73 (30.0%) injurious falls. Only five (6.8%) falls resulted in injury of major severity. We identified no significant differences in demographics between injurious and non-injurious falls. A logistic regression analyses of the independent risk factors of suffering an injurious fall were a history of falls (p=0.036), confusion (p=0.001) and an unsafe gait (p=0.03). However, we identified no significant differences in clinical characteristics between patients suffering injurious and non-injurious falls. None of the characteristics studied can identify patients prone to injury after a fall. Injury is largely unpredictable, and more research is needed to determine how injury can be prevented in patients at risk of falls.

Somatization among older primary care attenders

BACKGROUND

The importance of somatization among older primary care attenders is unclear. We aimed to establish the prevalence, persistence and associations of somatization among older primary care attenders, and the associations of frequent attendance.

METHOD

One hundred and forty primary care attenders over 65 years were rated twice, 10 months apart, on measures of somatization, psychiatric status, physical health and attendance.

RESULTS

The syndrome of GMS hypochondriacal neurosis had a prevalence of 5% but was transient. Somatized symptoms and attributions were persistent and associated with depression, physical illness and perceived poor social support. Frequent attenders (top third) had higher rates of depression, physical illness and somatic symptoms, and lower perceived support.

CONCLUSION

Somatization is common among older primary care attenders and has similar correlates to younger primary care somatizers. Psychological distress among older primary care attenders is associated with frequent attendance. Improved recognition should result in benefits to patients and services.

Polymorphism of the IGF2 gene, birth weight and grip strength in adult men

BACKGROUND

Grip strength is a simple measure of skeletal muscle function but a powerful predictor of disability, morbidity and mortality. Recent evidence has shown that prenatal and infant growth influence grip strength in later life; this may reflect genetic influences on muscle size and function, although strong candidate genes have not been identified. IGF II has proliferative effects in adult muscle and is one of the major determinants of fetal growth; polymorphism in the IGF2 gene could therefore link early growth to adult grip strength.

OBJECTIVES

To determine whether polymorphism of the IGF2 gene influences adult grip strength and mediates the association between size at birth and grip strength in later life.

METHODS

Polymorphism of the ApaI marker in the IGF2 gene was determined for 693 Hertfordshire men and women born between 1920 and 1930 who had taken part in a study linking early growth to ageing. Grip strength was measured using isometric dynamometry. Genotyping assay development was undertaken in Southampton Genetic Epidemiology Laboratories (http://www.sgel.humgen.soton.ac.uk).

RESULTS

In univariate analyses, IGF2 genotype and birth weight were both significant predictors of adult grip strength in the men after adjustment for age and current height. Significant associations were not seen in the women. When IGF2 genotype and birth weight in men were studied simultaneously, both contributed significantly to grip strength after adjustment for age and adult height.

CONCLUSIONS

These results show that polymorphism of the IGF2 gene and birth weight have independent effects on adult grip strength in men and suggest that IGF2 polymorphism does not explain the association between size at birth and grip in later life. This study provides preliminary evidence for independent genetic and early environmental programming of adult muscle strength.

Long-term care in rural West Virginia: managed care and future roles for the aging network

The managed care movement emphasizes the rationalization of health care delivery through fixed price or capitation of service and the utilization of a preferred physician or health gatekeeper. These features are advanced as measures of cost control in health care delivery. This approach presents the aging network, established under the Older Americans Act, with a number of daunting challenges which are particularly acute to service providers in rural areas. How this network responds will determine its future efficacy in the delivery of health and long-term care services. This article examines these concerns among eight rurally based senior centers and two Area Agencies on Aging in Southern West Virginia. Issues of management capacity, present and future positioning, and receptivity to managed care are emphasized. These providers stand on the strengths of a long tradition of serving clients, knowledge of their needs and face-to-face interactions with them--capabilities managed care organizations do not have. However, little outreach to managed care in these areas has occurred.

Comet Halley as an aggregate of interstellar dust and further evidence for the photochemical formation of organics in the interstellar medium

Photolysis of mixtures of CO:NH3:H2O at 12 K results in the formation of an organic residue which is not volatile in high vacuum at room temperature. Analysis of this fraction by GC-MS resulted in the detection of C2-C3 hydroxy acids and hydroxy amides, glycerol, urea, glycine, hexamethylene tetramine, formamidine and ethanolamine. Use of isotopically labeled gases made it possible to establish that the observed products were not contaminants. The reaction pathways for the formation of these products were determined from the position of the isotopic labels in the mass spectral fragments. The significance of these findings to the composition of comets and the origins of life is discussed.

Photochemical reactions in interstellar grains photolysis of CO, NH3, and H2O

A simulation of the organic layer accreted onto interstellar dust particles was prepared by slow deposition of a CO:NH2:H2O gas mixture on an Al block at 10 K, with concomitant irradiation with vacuum UV. The residues were analyzed by GC-MS, HPLC, and near IR; a reaction pathway leading from NH3 to complex alcohol, fatty acid, and amide products in 27 stages is postulated. The astronomical relevance and significance of the observations are discussed.

Sphenoid sinus mucocoele presenting as complete ophthalmoplegia

Sphenoid sinus mucocoeles represent 1% of all paranasal sinus mucocoeles. We describe a case of a sinus mucocoele with an atypical presentation comprising the sudden onset of a complete ophthalmoplegia. There was good recovery following drainage of the mucocoele.

Do all systems age together?

BACKGROUND

Aging changes in different body system are well described, but few studies have considered the relationship between them.

OBJECTIVE

The purpose of this study was, therefore, to investigate the interrelationships between markers of aging in different parts of the body.

METHODS

A cross-sectional study design was used. Structural and functional markers of aging were measured in a number of different body systems.

RESULTS

Conditional independence analysis demonstrated that the aging markers selected clustered into two groups, either related to chronological age or adult height. Visual acuity, lens opacity, hearing threshold, cognitive decline, and the number of teeth were associated with age, while systolic blood pressure and skin thickness were related to height. Grip strength was associated with both.

CONCLUSIONS

The differential associations of the aging markers with chronological age and adult height suggest that different systems do not age together. This may have relevance for understanding what underlies aging, and these preliminary findings now require replication in other aging cohorts.

Hindlimb-suspension and spaceflight both alter cGMP levels in rat choroid plexus

Effects of actual and simulated weightlessness on choroidal guanylate cyclase activity were evaluated by assaying the production of cyclic guanosine monophosphate (cGMP), a second messenger involved in mechanisms regulating the secretion of cerebrospinal fluid (CSF) in choroid plexus. Cyclic cGMP was measured, using radio-immunoassay, in choroidal extracts of hindlimb-suspended rats (HLS rats), adapted to an anti-orthostatic restraint for 30 min., or for 3, 9 or 14 days and after a 17-day spaceflight (Life and Microgravity SpaceLab experiment; LMS). Basal cGMP levels were slightly but significantly decreased in the first 30 min. of the HLS experiment, whereas they were significantly increased in rats adapted to longer anti-orthostatic restraints. LMS flight rats demonstrated a similar increase in the choroidal cGMP baseline. After natriuretic peptide stimulation, i.e. using ANP (atrial natriuretic peptide) or BNP (brain natriuretic peptide), choroidal cGMP contents were typically increased (by 1.5-2 times; p<0.05) in control rats (LMS and HLS experiments), but not significantly elevated in suspended rats, except for those adapted to HLS for 14 days. In these animals the ANP-dependent cGMP production was significantly increased (by about 3 times; p<0.005). The ANP- or BNP-dependent responses were similarly abolished in LMS flight rats, which were dissected 4-6 hours after return to Earth's gravity. The role of corticosteroids was also investigated during the LMS experiment. Results on choroidal functions revealed a lack of significant change of cGMP levels between adrenalectomized and sham-operated rats. For the first time, it is reported that both basal and ANP- stimulated cGMP levels are dramatically changed over the first 14 days of suspension, i.e. with experiments known to simulate some effects of weightlessness. Basal choroidal cGMP levels are also increased after 17 days in space, suggesting that space adaptation also impacts choroidal guanylate cyclase activities. However, the absence of ANP-dependent cGMP increase, observed in LMS flight animals, suggests that HLS could not simulate all the spaceflight effects. Thus, these preliminary results seem to show that a natriuretic peptides-independent s stem is involved in choroidal adaptation to spaceflight.

Biochemical characteristics of beta-adrenoceptors in rats after an 18-day spaceflight (LMS-STS78)

BACKGROUND

To ascertain whether there was autonomic adaptation with the development of adrenoceptor hypersensitivity under microgravity, the biochemical properties of the beta-adrenoceptors were determined using (125I)iodocyanopindolol (ICYP) binding in rats flown for 18 d onboard the space shuttle.

METHODS

This study was performed on heart and kidneys of 3 groups of 12 animals: the flight and 2 ground control (vivarium and AEM) groups. To distinguish the possible role of the corticosteroids, half of each animal group was bilaterally adrenalectomized (ADX rats) with an aldosterone and corticosterone supplementation while the other half was SHAM operated.

RESULTS

The Scatchard analysis of the ICYP-binding in both organs revealed no significant alterations in the dissociation constant (Kd) and in the maximal binding capacity (Bmax) between SHAM flight and control groups. The Kd of the beta-adrenoceptors in the cardiac atria of the SHAM flight rats (74 +/- 5 pm) was significantly higher (p < 0.05) than in those of the ADX flight rats (60 +/- 3 pm) while the Bmax was nonsignificantly higher (1925 +/- 370 in SHAM flight rats vs. 1482 +/- 283 fmol x mg(-1) protein in ADX flight rats). No significant change was determined for the Bmax and Kd values in the kidneys of the ADX and SHAM flight rats.

CONCLUSIONS

This work performed on animals did not show any obvious effect of microgravity on the beta-adrenergic function in the heart and kidneys. Inflight rodent sacrifice protocols should definitely ensure assessment of the influence of microgravity on the animals.

A study of the effectiveness of an interactive computer classroom

This study examined the use of an interactive computer classroom (ICC) compared with a traditional lecture/discussion format (LD) for a nursing management course taught from fall semester 1994 through fall semester 1996. The ICC was structured around a group systems support software, a tool previously used in business settings for group decision-making activities. Structured learning activities allowed all students to participate simultaneously and anonymously. Data were collected during the second and final semesters of the study. The outcomes included academic performance, measured by course exams; class participation, measured by direct observation; and attendance records. The control group was a concurrent management course taught with the same objectives and evaluated by identical examinations. The examination scores and the frequency of class participation of the ICC group were significantly higher than those measures of the LD group. There was no significant difference in class attendance. Evaluation forms with open-ended questions were completed by the ICC students and revealed that the students believed that the process enhanced application and understanding. The negative aspects of the ICC experience were the need for increased preparation time for faculty and the students' lack of tolerance when technical difficulties caused delays.

A methodologic issue for ophthalmic telemedicine: image quality and its effect on diagnostic accuracy and confidence

BACKGROUND

The possibility of ophthalmic telemedicine raises questions as to the quality of images displayed on a video display terminal and its effect on a doctor's accuracy and confidence of diagnosis. This study compares diagnostic accuracy and confidence levels of subjects observing two formats of retinal imaging.

METHODS

Test images included 90 conventional 4- x 6-inch retinal fundus photographs and the same set of photographs after they had been scanned, digitized, modified in brightness and contrast, and displayed on a video display terminal. Fifty-six of the images demonstrated one or more retinal anomalies; the remaining 34 were of normal fundi. Abnormalities were selected on the basis of estimates of prevalence in the general population. Twenty optometrists affiliated with the Southern California College of Optometry participated as subjects. One group of 10 was shown the photographs; the remaining ten subjects were shown the digitized images. Both groups were asked if the pictures were "healthy" or "unhealthy," how confident they were of their decision, and, if abnormal, what was the ocular disease.

RESULT

T-tests were used to compare the results of the two groups. There was a statistically significant difference in the confidence of a specific diagnosis between the two groups (p = 0.018), as well as tendencies toward significance on other measures.

CONCLUSION

Viewing digitally reconstructed photographic images of the retina on a video display caused doctors to lose confidence in making a diagnosis before they lost accuracy.

Renal hemodialysis and maternal serum triple analyte screening

The obstetrical management of women with renal disease is complicated and associated with increased fetal and maternal morbidity. However, maternal serum screening is an integral part of obstetrical care and should be offered to all women. We found that maternal serum levels of a-fetoprotein and human chorionic gonadotropin did not significantly change as a result of hemodialysis, whereas levels of unconjugated estriol were markedly decreased following hemodialysis. Maternal serum screening should be limited to alpha-fetoprotein analysis in women undergoing hemodialysis until the effects of hemodialysis on all serum analytes are better delineated.