A novel service delivery model for infant hearing screening in developing countries

Newborn hearing screening is the procedure of choice for ensuring optimal outcomes for infants with hearing loss, whether in a developed or developing country. Unfortunately, apart from a small number of recent exceptions, newborn hearing screening has been a practice reserved for the developed world. Despite the prevailing challenges towards implementing hearing screening in developing countries, there are existing structures in these countries that need to be investigated as possible platforms from which programs can be actualized. Immunization clinics, constituting part of a primary healthcare approach characteristic of developing countries, offer one such a platform. A novel service delivery model, based on initial results from a pilot study, was developed for infant hearing screening at immunization clinics in South Africa as an integrated part of primary, secondary, and tertiary levels of healthcare. This type of model is a first step toward ensuring that infants with hearing loss in developing communities are afforded opportunities for optimal development and societal integration through accountable and contextually relevant early hearing detection and intervention services.     

血管球瘤10例诊断与治疗

目的: 探讨血管球瘤的诊断及治疗。方法: 对10例血管球瘤患者施行血管球瘤切除手术。结果: 10例术后症状均消失,经病理检查证实临床诊断。平均随访38个月,无复发病例。结论: 血管球瘤具有典型的临床表现,诊断并不困难,手术切除肿瘤是治疗该病的有效方法。     

Aided auditory steady-state responses in infants

Infants with hearing loss routinely receive hearing aids several months before reliable behavioral responses to amplified sound can be observed. This necessitates objective measures to validate hearing-aid fittings. A single report has demonstrated the use of ASSRs to determine aided thresholds in children but data in young infants is still lacking. The current study explored aided ASSR compared to unaided ASSR thresholds and subsequent behavioral thresholds in a group of six young infants with hearing loss who received hearing aids between three and six months of age. Aided ASSR thresholds were obtained in 83% of frequencies where aided behavioral thresholds were obtained, with a mean threshold difference of 13+/-13 dB. The aided ASSR-based threshold estimates were within 15 dB of behavioral thresholds in 63% of cases, indicating a moderate correlation (r = 0.55). Comparing aided and unaided ASSR measurements revealed an average functional gain of 36+/-15 dB. These results indicate that ASSRs can provide the first evidence of robust hearing aid benefit in young infants several months before behavioral responses are observed.     

Mild hypercapnia after uncomplicated heart surgery is not associated with hemodynamic compromise

OBJECTIVE: The aim of this study was to examine the effects of small changes in PaCO(2) on hemodynamic parameters after uncomplicated heart surgery with cardiopulmonary bypass. DESIGN: This was a prospective, randomized crossover study. SETTING: A large academic medical center. PARTICIPANTS: Twenty-four subjects who were scheduled for elective cardiac surgery were enrolled in this study. INTERVENTIONS: Each subject underwent the normal procedures that are associated with cardiac surgery. General anesthesia, including muscle relaxation, were continued in the immediate postoperative period. Measured tidal volumes and minute ventilation were kept constant for the duration of the study. Target PaCO(2) concentrations of 30, 40, and 50 mmHg were achieved by adding varying amounts of exogenous CO(2) gas to the inhaled oxygen. Various measurements were made at each target PaCO(2), including cardiac index, mixed venous oxygen saturation, blood pressure, heart rate, and pulmonary artery pressure. MEASUREMENTS AND MAIN RESULTS: Twenty-four patients were enrolled. Seven were withdrawn before commencement of the study. The cardiac index increased when the PaCO(2) was increased from 30 to 40 mmHg (p < 0.001) and remained unchanged between 40 and 50 mmHg. Mixed venous oxygen saturation increased (p < 0.001) with elevations in PaCO(2) up to 50 mmHg and decreased again when the PaCO(2) was returned to 30 mmHg. The blood pressure decreased (p < 0.001) with increasing PaCO(2). The pulmonary pressure increased (p < 0.001) with elevations in PaCO(2). No patient became hemodynamically unstable or had any arrhythmias. CONCLUSION: The findings of this study suggest that unless there is a specific contraindication to mild hypercapnia, such as pulmonary hypertension or hemodynamic instability, concerns about mild respiratory acidosis should not prevent weaning of sedation and mechanical ventilation after uncomplicated heart surgery.     

The importance of prior stroke for the adjusted risk of neurologic injury after cardiac surgery for women and men

BACKGROUND: Women are at higher risk for stroke after cardiac surgery than men. Prior analysis of risk profiles for perioperative stroke that have mostly combined data from women and men may fail to identify gender-specific risks. The purpose of this study was to evaluate whether patient gender impacts adjusted risk for stroke after cardiac surgery. METHODS: Demographic and perioperative data were prospectively collected from 2,972 patients undergoing cardiac surgery. Carotid artery ultrasound examination was performed before surgery for patients aged 65 yr or older or when there was a history of transient ischemic attacks or prior stroke. Epiaortic ultrasound was performed at the time of surgery in all patients to assess for atherosclerosis of the ascending aorta. RESULTS: Strokes occurred after surgery in 30 women and 18 men (P < 0.0001). Based on multivariate logistic regression analysis, a history of a stroke was the strongest predictor of new stroke for both women and men. Low cardiac output syndrome, atherosclerosis of the ascending aorta, and diabetes mellitus were significantly associated with stroke for women but not for men. Analysis on the data from all patients using a gender-interaction term found that the risk for stroke associated with patient age, atherosclerosis of the aorta, diabetes, and duration of cardiopulmonary bypass was not affected by gender. The prior stroke-gender interaction, however, was significant (P = 0.017), suggesting that a prior cerebrovascular event was a more important predictor of stroke for men than women. CONCLUSIONS: These data show that prior stroke before surgery is strongly and independently associated with susceptibility for stroke after cardiac surgery, particularly for men. Other risk factors for perioperative stroke, though, do not appear to be influenced by patient gender.     

Toxicity of Diplodia maydis in farm and laboratory animals

The acute toxicity of maize culture material of eight strains of Diplodia maydis in ducklings, as well as the ability of five of these strains to induce typical diplodiosis (a neuromuscular disease) in cattle and sheep was shown. Typical diplodiosis was induced in 17 sheep and 11 cattle. Two of the five toxic strains were isolated from maize involved in diploidiosis outbreaks, the others from commercial maize. Strains inducing diplodiosis could be isolated from commercial maize from the USA, Argentina and South Africa. There was no correlation between the toxicity of D. maydis strains in ducklings and their ability to induce diplodiosis in cattle and sheep. Some isolates were acutely toxic to ducklings and rats but were unable to induce diplodiosis in either cattle or sheep. Others, equally toxic to ducklings and rats, induced diplodiosis in cattle and sheep at low dose levels. Two doses, each of 5 g/kg, of maize culture material of isolates from the USA, Argentina and South Africa induced diplodiosis in sheep. Culture material incubated for less than 8 wk could not induce diplodiosis in cattle. Acute toxicity in ducklings and rats also increased with longer incubation periods. Cultures of non-sporulating and profusely sporulating strains were equally toxic to ducklings. Heat treatment of culture material for 48 days at 45 degrees C failed to reduce toxicity in ducklings.     

Early detection of poor fetal prognosis by serial Doppler velocimetry in high-risk pregnancies.

Fifty-three high-risk pregnancies were followed up serially with Doppler velocimetry of the umbilical artery and uterine vessels from early on to investigate whether abnormalities in Doppler waveforms can predict the outcome of pregnancy accurately before other clinical signs develop. Results of Doppler velocimetry were withheld from the clinicians managing the patients. When the absence of end-diastolic velocities was first detected (in 13 fetuses) (AEDV group) there was no clinical difference between these pregnancies and those in which end-diastolic velocities were present (EDV group). Nine of the 13 fetuses with AEDVs died, compared with 3 of 40 with EDVs (P less than 0.0001). In deaths associated with AEDVs, the latter were detected a median of 5.5 (range 3-11) weeks before death and are present from the first Doppler examination. In the 4 fetuses with AEDVs that survived, the AEDVs were not persistent. The only significant association of Doppler velocimetry of the uterine vessels was with proteinuric hypertension (P less than 0.05), but the prediction was not strong enough to be of clinical value. Persistent AEDVs of the umbilical artery are an accurate predictor of poor fetal outcome and occur before other clinical signs of impending problems.     

The effect of placement technique on marginal adaptation of posterior resins

Polymerization shrinkage of posterior resin restorations leads to margins that pull away from the tooth, or to cracks in the material itself. The purpose of this study was to determine the effect of three different placement techniques on the marginal adaptation (or in effect the amount of polymerization shrinkage) of posterior resin restorative materials. Three posterior resin materials, namely, Distalite, Heliomolar and P30 were included in this study. Each of these materials were placed by means of three different placement techniques (Bulk pack, Horizontal layering and Vertical layering) into class II cavities in extracted human molars. No dentine bonding agents were used. The samples were light cured, the teeth sectioned longitudinally and stored dry before examination in a Scanning Electron Microscope. Results showed polymerization shrinkage with all three techniques, with the poorest the bulk pack technique where large marginal discrepancies were visible. No significant differences were detected between the horizontal and vertical placement techniques, but the two microfilled resins Heliomolar and Distalite showed significantly poorer marginal adaptation than the small particle conventional resin, P30. All three materials had better adaptation on the occlusal margins than on the margins situated along the floor of the cavity or the gingival margins of the proximal box of the cavity. It can be concluded that the bulk pack technique should be avoided as this leads to large contraction gaps at most of the margins of the restoration.     

Characterization of a novel dsRNA element in the pine endophytic fungus Diplodia scrobiculata

Diplodia scrobiculata and Diplodia pinea are endophytic fungi associated with dieback and cankers of mainly Pinus spp. in many parts of the world. These two fungi are closely related and have, in the past, been considered to represent two morphological forms (A and B morphotypes) of D. pinea. dsRNA elements are known to occur in both D. scrobiculata and D. pinea. Two dsRNA elements from D. pinea, SsRV1 and SsRV2, have been characterized previously. The aim of this study was to characterize a third dsRNA element that is most commonly associated with D. scrobiculata and to determine its phylogenetic relationship to other mycoviruses. The 5018-bp genome of this element was sequenced, and it is referred to as D. scrobiculata RNA virus 1, or DsRV1. It has two open reading frames (ORFs), one of which codes for a putative polypeptide with a high degree of similarity to proteins of the vacuolar protein-sorting (VPS) machinery, and the other for an RNA-dependent RNA polymerase (RdRp). Phylogenetic comparisons based on amino acid sequence alignments of the RdRp revealed that DsRV1 is closely related to a dsRNA element isolated from Phlebiopsis gigantea (PgV2), and they grouped separately from virus families in which mycoviruses have previously been described. Although D. pinea and D. scrobiculata are closely related, DsRV1 does not share high sequence identity with SsRV1 or SsRV2, and they probably have different recent evolutionary origins.