Paediatric hearing loss: a community-based survey in peri-urban Kumasi, Ghana.

BACKGROUND: Paediatric hearing loss rates in Ghana are currently unknown. METHODS: A cross-sectional study was conducted in peri-urban Kumasi, Ghana; children (aged 3-15 years) were recruited from randomly selected households. Selected children underwent otoscopic examination prior to in-community pure tone screening using the portable ShoeBox audiometer. The LittlEars auditory questionnaire was also administered to caregivers and parents. RESULTS: Data were collected from 387 children. After conditioning, 362 children were screened using monaural pure tones presented at 25 dB. Twenty-five children could not be conditioned to behavioural audiometric screening. Eight children were referred based on audiometric screening results. Of those, four were identified as having hearing loss. Four children scored less than the maximum mark of 35 on the LittleEars questionnaire. Of those, three had hearing loss as identified through pure tone screening. The predominant physical finding on otoscopy was ear canal cerumen impaction. CONCLUSION: Paediatric hearing loss is prevalent in Ghana, and should be treated as a public health problem warranting further evaluation and epidemiology characterisation.

Otolaryngology outreach to Komfo Anokye Teaching Hospital: a medical and educational partnership.

BACKGROUND: Medical and educational partnerships between high- and low-resourced countries provide opportunities to have a long-term meaningful impact on medical training and healthcare delivery. METHODS: An otolaryngology partnership between Komfo Anokye Teaching Hospital in Kumasi, Ghana, and the University of Michigan Department of Otolaryngology/Head and Neck Surgery has been undertaken to enhance healthcare delivery at both institutions. RESULTS: A temporal bone dissection laboratory, with the equipment to perform dedicated otological surgery, and academic platforms for clinical and medical education and residency training have been established. CONCLUSION: This article describes the details of this partnership in otological surgery and hearing health, with an emphasis on creating in-country surgical simulation, training on newly acquired medical equipment and planning regarding the formulation of objectified metrics to gauge progress going forward.

Isolation and tissue profiles of a large panel of phage antibodies binding to the human adipocyte cell surface.

Phage display is a powerful technique for the rapid selection and isolation of antibodies to any given target antigen. We have applied this technology to isolate over 100 different human antibodies that bind to antigens expressed in situ on the human adipocyte cell surface. This is a diverse panel of antibodies, as indicated by the V-region sequences. The binding profile of each anti-adipocyte antibody has been characterised using phage antibody immunocytochemistry against a panel of normal human tissues. Although there was some variation in the intensity of the adipocyte staining, each antibody consistently recognised adipocytes, where present, irrespective of the tissue source. In addition, all of the antibodies recognised at least one other cell type other than the adipocyte cell surface. In total, over 50 different tissue-binding profiles were recorded, with the most frequently recognised tissues identified as capillaries or smooth muscle. Extensive tissue binding profiles were generated for some antibodies using a panel of 37 different human tissues. This identified anti-adipocyte antibodies with unexpected profiles, such as FAT.13, which binds only to adipocytes and capillaries in the entire tissue panel. We believe this is the most extensive survey ever undertaken of the human adipocyte cell surface. Moreover, similar methodology could be used to derive complete tissue-binding profiles of antibodies against cell-surface antigens of any cell type. Indeed, by screening antibodies on both normal and diseased tissues, it may be possible to identify antigenic associations between different cell types and the pathologies of many diseases.

Hearing improvement after resection of cerebellopontine angle meningioma: case study of the preoperative role of transient evoked otoacoustic emissions.

In a retrospective case study of a patient with a right-sided cerebellopontine angle mass lesion, transient evoked otoacoustic emissions were robustly present despite a severe to profound sensorineural hearing loss and abnormal auditory brainstem response. These results were interpreted as suggestive of a neural site of lesion, and the potential for planned, preserved, or improved hearing by a suboccipital surgical craniotomy was considered. A gross total resection was successful. Three years postoperatively, the patient has normal hearing sensitivity and word recognition ability.

Clinical manifestations of CHARGE Association.

The clinical literature regarding CHARGE Association is mostly retrospective in nature and deals largely with non-auditory issues related to the care and management of these patients with multisystem involvements. In this paper, we describe the clinical findings in 24 patients evaluated in the Division of Audiology and Electrophysiology at the University of Michigan Medical Center from 1983 to 1993. We report on the clinical manifestations of CHARGE Association in these patients with particular attention paid to their audiologic status. We discuss the relationships between auditory, ear, and craniofacial anomalies. Our review of these previously unreported cases suggests the following: (1) a variety of audiologic outcomes is possible, however, if a sensorineural or mixed hearing loss exists, it tends to be severe in degree; (2) progressive hearing loss does not appear to occur, but recurring otitis media is a probable confounding factor in the early identification of hearing loss; (3) congenital unresolved facial weakness may serve as a reliable predictor of sensorineural hearing loss; and (4) amplification use may be poor due to a number of factors. We hope to offer guidance to the professionals from assorted disciplines who participate in the care of these children.

Cervical cancer screening in Western Australia in 1992: progress since 1983.

OBJECTIVES: To estimate the rate of cervical cancer screening in Western Australia in 1992, and any variation by age, place of residence, and socio-economic status; and to determine the proportion of smears taken by different service providers. DESIGN: Descriptive study; collection of data from Papanicolaou (Pap) smear request forms during one calendar month. SETTING: All 13 cytology laboratories in Western Australia. PARTICIPANTS: 15,767 women in Western Australia aged 15 years and over having a cervical smear in March 1992. MAIN OUTCOME MEASURES: Rates by age of cervical cancer screening per 1000 woman-years; age-standardised rate ratios for socioeconomic status and place of residence; proportion of smears taken by male and female service providers. RESULTS: The estimated rate of Pap smears at ages 15 years and over was 303 smears per 1000 woman-years, an increase of 44% over a similar survey in 1983. The greatest increases were among women aged 50 years and over, but their rates were still well below that equivalent to three-yearly smears. Differences in the rate of screening by socioeconomic status (defined by residential postcode) were not statistically significant. The age-standardised rate ratio comparing country women with women in the Perth metropolitan area was 0.91 (95% confidence interval 0.87-0.94). General practitioners took 78% of the smears, and at least 46% of all smears were taken by female service providers. Almost all the increase in the screening rate since 1983 could be attributed to an increase in the rate of smears per 1000 woman-years taken by female general practitioners. CONCLUSION: While there have been marked improvements in the rates of cervical screening in Western Australia over the past nine years, there are still major deficiencies in the screening coverage of women aged 50 years and over.

Stimulation of glucose transport in rat cardiac myocytes by guanosine 3',5'-monophosphate.

Glucose transport in isolated rat cardiomyocytes is stimulated by insulin, catecholamines, and anoxia approximately 2- to 3-fold over basal rates. The molecular mechanisms controlling these responses are unknown. In our search for possible cellular mediators of glucose transport stimulation, we examined the effects of a number of nucleotides on 3-O-methylglucose transport in heart cells. The nucleotides and/or permeable analogs (monosuccinyl, 8-bromo, and dibutyryl derivatives) included cUMP, cIMP, cCMP, cAMP, and cGMP at concentrations ranging from 10 nM to 1 mM. Of all the nucleotides tested only cGMP analogs induced a significant stimulation of transport at concentrations as low as 100 nM. This effect was observed in both the 8-bromo- and dibutyryl derivatives and with 1 mM cGMP itself. The effect was concentration dependent for both analogs and produced a maximal response equivalent to that of 100 nM insulin. This insulinomimetic effect of cGMP was examined in more detail in order to evaluate its role as a potential mediator of this response. Agents that are known to stimulate guanylate cyclase in the heart produced a clear stimulation of transport when added to cardiomyocytes. These include insulin, aminophylline, histamine, beta-estradiol, and biotin-nitrophenyl ester. Methylene blue, an inhibitor of guanylate cyclase, blocked the insulin response when added to cells before insulin, but was ineffective when added after insulin. In addition, agents that raise intracellular cGMP levels by inhibiting cyclic nucleotide phosphodiesterases were also examined for effects on glucose transport. Out of several phosphodiesterase inhibitors tested, only Zaprinast (which selectively increases cGMP in heart) stimulated transport in a concentration-dependent manner to within 80% of the maximal insulin effect. These results are consistent with the notion that cGMP may be involved in glucose transport stimulation.

[3H]forskolin. Direct photoaffinity labeling of the erythrocyte D-glucose transporter.

Irradiation of erythrocyte ghosts in the presence of [3H]forskolin resulted in a concentration-dependent, covalent incorporation of radiolabel into several of the major membrane protein bands. Most of the incorporation occurred in four regions of the gel. Peak 1 (216 kDa) was a sharp peak near the top of the gel in the region corresponding to spectrin. Peak 2 appeared to be associated with band 3 (89 kDa), while a third peak occurred around the position of band 4.2 (76 kDa). The fourth region of labeling was a broad area between 43-75 kDa which corresponds to the region of the glucose transporter. Forskolin labeling of this region was inhibited by cytochalasin B and D-glucose, but not L-glucose. Extraction of extrinsic membrane proteins resulted in a loss of radiolabeled protein from the 216- and 76-kDa regions. Treatment of membranes labeled with either cytochalasin B or forskolin with endo-beta-galactosidase resulted in identical shifts of the 43 to 75-kDa peaks to 42 kDa. Similarly, trypsinization of membranes photolabeled with either cytochalasin B or forskolin resulted in the generation of a 17-kDa radiolabeled fragment in both cases. Photoincorporation of [3H]cytochalasin B into the glucose transporter was blocked in a concentration-dependent manner by unlabeled forskolin.

Interactions of insulin, catecholamines and adenosine in the regulation of glucose transport in isolated rat cardiac myocytes.

The regulation of the glucose transport system by catecholamines and insulin has been studied in isolated rat cardiomyocytes. In the basal state, 1-isoproterenol exhibited a biphasic concentration-dependent regulation of 3-O-methylglucose transport. At low concentrations (less than 10 nM), isoproterenol induced a maximal inhibition of 65-70% of the basal rates, while at higher concentrations (greater than 10 nM) a 25-70% stimulation of transport was observed. In the presence of adenosine deaminase, the inhibition of isoproterenol at low doses was attenuated. No effect of adenosine deaminase was observed on the stimulation of transport at high doses of isoproterenol. The inhibitory effect of isoproterenol returned when N6-phenylisopropyladenosine (a non-metabolizable analog of adenosine) was included along with adenosine deaminase. Dibutyryl cAMP and forskolin both inhibited basal transport rates. In the presence of maximally stimulating concentrations of insulin, cardiomyocyte 3-O-methylglucose transport was generally elevated 200-300% above basal levels. In the presence of isoproterenol, insulin stimulation was inhibited at both high and low concentrations of catecholamine, with maximum inhibition occurring at the lowest concentrations tested. When cells were incubated with both adenosine deaminase and isoproterenol, the inhibition of the insulin response was greater at all concentrations of catecholamine and was almost completely blocked at isoproterenol concentrations of 10 nM or less. Dibutyryl cAMP inhibited the insulin response to within 10% of basal transport levels, while forskolin completely inhibited all transport activity in the presence of insulin. These results suggest that catecholamines regulate basal and insulin-stimulated glucose transport via both cAMP-dependent and cAMP-independent mechanisms and that this regulation is modulated in the presence of extracellular adenosine.