Do topical ophthalmic corticosteroids suppress the hypothalmic-pituitary-adrenal axis in post-penetrating keratoplasty patients?

PURPOSE

To establish whether hypothalmic-pituitary-adrenal axis suppression is possible secondary to long-term topical ophthalmic corticosteroid use in patients who have undergone penetrating keratoplasty (PKP).

METHODS

Patients who had undergone a PKP and had been using corticosteroid-based eye drops continuously for more than 6 months, with no history of concomitant steroid (oral, inhaled, or cutaneous) use, were included within the study. A low-dose short Synacthen (LDSST) test was performed in each patient followed later by a short Synacthen test (SST). The mean SST and LDSST after 30 min were calculated along with their corresponding 95% confidence intervals (CIs). Correlation between both baseline SST and baseline LDSST with duration of treatment was determined using Spearman's correlation.

RESULTS

In all, 20 patients were included within the study. The mean duration treatment was 28.2 months (range 11-96 months). All patients had normal baseline cortisol levels in both SST and LDSST tests. The mean 30 min SST was 753.8 nmol/l (95%CI: 696.6 nmol/l, 811.0 nmol/l) and no patients displayed inadequate adrenal response. The mean 30 min LDSST was 709.8 nmol/l (95%CI: 665.1 nmol/l, 754.5 nmol/l) and only one patient had an inadequate adrenal response. There was no correlation between baseline SST or LDSST and duration of treatment.

CONCLUSIONS

This study found no evidence that patients using continuous long-term corticosteroid eye drops after PKP experienced inadequate adrenal response. We did not find any evidence of a negative correlation between length of treatment and SST or LDSST measurements at baseline.

1.12 Tb/s superchannel coherent PM-QPSK InP transmitter photonic integrated circuit (PIC)

In this work, a 10-wavelength, polarization-multiplexed, monolithically integrated InP coherent QPSK transmitter PIC is demonstrated to operate at 112 Gb/sec per wavelength and total chip superchannel bandwidth of 1.12 Tb/s. This demonstration suggests that increasing data capacity to multi-Tb/s per chip is possible and likely in the future.

Prospective study of antenatally diagnosed congenital cystic adenomatoid malformations

PURPOSE

Congenital cystic adenomatoid malformations (CCAMs) are increasingly diagnosed in recent years due to the routine usage of antenatal ultrasound. The aim of this study was to present the natural course and outcome of antenatally diagnosed cystic lung diseases, which were prospectively studied.

METHODS

Between the period June 2004 and June 2010, 25 fetuses with suspected CCAMs were seen in a single tertiary maternal fetal unit. One child was excluded as the fetal MRI suggested congenital diaphragmatic hernia. Data were prospectively entered into a database including antenatal and postnatal findings which were then analyzed.

RESULTS

Mean gestational age at the time of diagnosis was 20.8 weeks (range 17-29). Fetal interventions included amnioreduction (n = 2) and fetal thoracocentesis (n = 3) in one child. The mean gestational age at delivery was 38.5 weeks (range 31.6-40.6). None of the mothers underwent termination of pregnancy or spontaneous abortion. All patients underwent postnatal radiological assessment. Of the 24 cases, 5 children were symptomatic in the immediate neonatal period and 19 were asymptomatic. Anatomical surgical resection was undertaken in all symptomatic cases. There was one death in this group due to severe pre-existing pulmonary hypoplasia. Among the 19 asymptomatic cases, 5 children were managed conservatively as the lesions were not significant and the remaining 14 (73%) underwent surgical resection. The mean age at surgery was 11.1 months (range 3.3-34 months). Postnatal pathology confirmed CCAM in all operated cases, except one who had pulmonary sequestration.

CONCLUSION

Antenatally diagnosed CCAMs have an excellent prognosis except in children with a large lesion and associated with lung hypoplasia. Postnatal investigations are required in all cases to confirm the diagnosis. Symptomatic CCAMs require immediate surgery in the neonatal period with a good outcome. Asymptomatic CCAMs can be safely operated between 9 and 12 months of age.

Severe late anemia of hemolytic disease of the newborn

Late anemia is a well-recognized complication of Rhesus hemolytic disease of the newborn (HDN). The incidence of Rhesus HDN is declining, with a tendency for more severely affected pregnancies to be managed in specialist centres. Consequently, many paediatric departments may see relatively few affected infants with comparatively mild disease, and the risk of late anemia in such cases may not always be appreciated. Two cases of infants born with evidence of Rhesus isoimmunization noted at birth and encountering no immediate problems other than mild hyperbilirubinemia are described. After an uneventful early neonatal course, both infants were discharged without follow-up and presented in the second to third weeks of life with severe, life-threatening anemia, leading to neurological sequelae in one case. The importance of close surveillance, including hemoglobin measurements, in all infants with Rhesus hemolytic disease, irrespective of initial severity, is reiterated.

Inhalation of 7.5% carbon dioxide increases threat processing in humans

Inhalation of 7.5% CO(2) increases anxiety and autonomic arousal in humans, and elicits fear behavior in animals. However, it is not known whether CO(2) challenge in humans induces dysfunction in neurocognitive processes that characterize generalized anxiety, notably selective attention to environmental threat. Healthy volunteers completed an emotional antisaccade task in which they looked toward or away from (inhibited) negative and neutral stimuli during inhalation of 7.5% CO(2) and air. CO(2) inhalation increased anxiety, autonomic arousal, and erroneous eye movements toward threat on antisaccade trials. Autonomic response to CO(2) correlated with hypervigilance to threat (speed to initiate prosaccades) and reduced threat inhibition (increased orienting toward and slower orienting away from threat on antisaccade trials) independent of change in mood. Findings extend evidence that CO(2) triggers fear behavior in animals via direct innervation of a distributed fear network that mobilizes the detection of and allocation of processing resources toward environmental threat in humans.

Patterns of airway disease and the clinical diagnosis of asthma in the Busselton population

The aim of this study was to examine how objective measures related to lung function cluster in the general population and how the patterns relate to asthma and bronchitis as diagnosed by a doctor (DDA and DDB, respectively). A cross-sectional survey of an age-stratified random general population sample of 1,969 adults from the electoral register of Busselton (Australia) was performed in 2005-2007. Respiratory symptoms, DDA ever, DDB ever, recent wheezing and smoking history, together with anthropometric measurements, forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC), methacholine challenge or bronchodilator response, exhaled nitric oxide (eNO), skin-prick tests to common allergens, and blood eosinophil and neutrophil counts were studied. Cluster analysis (variables sex, age, atopy, FEV₁ % predicted, FEV₁/FVC, airway hyperresponsiveness, eNO, log eosinphil count, log neutrophil count and body mass index) was used to identify phenotypic patterns. Seven clusters (subjects with DDA and DDB, respectively) were identified: normal males (n=467; 7 and 13%), normal females (n=477; 12 and 18%), obese females (n=250; 16 and 28%), atopic younger adults (n=330; 21 and 17%), atopic adults with high eNO (n=130; 30 and 25%), atopic males with reduced FEV₁ (n=103; 33 and 32%) and atopic adults with bronchial hyperreactivity (n=212; 40 and 26%). The clinical diagnosis of asthma (ever) and bronchitis (ever) is not specific for any of the clustering patterns of airway abnormality.

Greater white and grey matter changes associated with early cannabis use in adolescent-onset schizophrenia (AOS)

BACKGROUND

Cannabis use is associated with a higher risk of schizophrenia, however, its specific long-term effect on the structure of the brain of adolescent-onset schizophrenic patients remains unclear.

AIMS

To study cognitive and structural (grey and white matter) changes in patients with adolescent-onset schizophrenia (AOS) with early cannabis use (CAN+ve) (more than 3 times/week for at least 6 months) and without cannabis use (CAN-ve) versus controls.

METHOD

An optimised voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) MRI study of 32 adolescents with DSM IV schizophrenia-16 CAN+ve and 16 CAN-ve, and 28 healthy adolescents.

RESULTS

Compared to CAN-ve subjects, CAN+ve subjects showed GM density loss in temporal fusiform gyrus, parahippocampal gyrus, ventral striatum, right middle temporal gyrus, insular cortex, precuneus, right paracingulate gyrus, dorsolateral prefrontal cortex, left postcentral gyrus, lateral occipital cortex and cerebellum. Similar group comparison showed decreased fractional anisotropy (FA) in particular in brain stem, internal capsule, corona radiata, superior and inferior longitudinal fasciculus in CAN+ve patients. No cognitive differences were apparent between CAN+ve and CAN-ve subjects, and both were impaired relative to controls.

CONCLUSION

Cannabis use in early adolescence increases WM and GM deficits in AOS, but does not appear to increase the cognitive deficit associated with this illness.

Chromosomal alterations in Malaysian patients with nasopharyngeal carcinoma analyzed by comparative genomic hybridization

Nasopharyngeal carcinoma (NPC) is one of the most common cancers in Malaysia, mainly occurring among the Chinese population. To detect common genetic alterations in NPC, we screened seven cases of NPC using the comparative genomic hybridization (CGH) technique. Before proceeding to the CGH technique, the tumors were first confirmed to consist of 75% tumor cells or more. In brief, the technique consists of binding tumor DNA with normal DNA and human Cot-1 DNA, which is then hybridized to normal metaphase spreads. The slides were then counterstained with 4,6 diamino-2-phenylindole (DAPI II) for detection. Analyses were performed using CGH software (Cytovision). We found genetic alterations in all seven NPC samples. The common chromosomal gains (57%, four cases) were found on chromosome arms 1q, 4p, 5, 7q, 11, 14p, 15q, 18p, and 21p, and common chromosomal losses (43%, three cases) were found on chromosome arm 16p. Our results showed chromosomal alterations in all seven NPC cases in the Malaysian population. This result provides the platform for further investigations to locate tumor suppressor genes and oncogenes at specific chromosomal regions in Malaysian NPC patients.

Revisiting imaging features and the embryologic basis of third and fourth branchial anomalies

BACKGROUND AND PURPOSE

There is wide discrepancy between common clinical and radiologic presentations of branchial sinuses arising from the pyriform fossa and the theoretic course of third and fourth branchial arch anomalies. The purpose of this study was to revisit the clinical presentations and imaging features of such anomalies in children.

MATERIALS AND METHODS

A retrospective review of institutional and diagnostic imaging data bases from 1998 to 2008 for reported cases of third and fourth branchial cleft anomalies was conducted. Clinical presentation, pharyngoscopy results, and imaging features in all the patients were evaluated. Surgical and histopathology correlation in patients who underwent excision of the tract was also obtained.

RESULTS

Twenty reported cases described as third or fourth branchial apparatus anomalies were identified. There were 12 females and 8 males with a mean age of 84.6 months. The most common presentation was an inflammatory neck mass (18/20, 90%) almost always involving the thyroid gland. Most lesions were on the left side (16/20, 80%). Pharyngoscopy showed a sinus opening at the piriform fossa in 18/20 (90%) cases. None of the cases followed the classic theoretic pathway of third and fourth arch remnants. Histopathology showed tracts lined with pseudostratified squamous epithelium or ciliated columnar epithelium often associated with inflammatory changes in 17 surgically resected cases.

CONCLUSIONS

Branchial sinuses arising from the pyriform fossa often present with an inflammatory neck mass involving the thyroid lobe, most often on the left side. Imaging and surgical findings suggest that they arise from the embryonal thymopharyngeal duct of the third branchial pouch, because they do not follow the hypothetic course of third or fourth arch fistulas.

Increased myoepithelial cells of bronchial submucosal glands in fatal asthma

BACKGROUND

Fatal asthma is characterised by enlargement of bronchial mucous glands and tenacious plugs of mucus in the airway lumen. Myoepithelial cells, located within the mucous glands, contain contractile proteins which provide structural support to mucous cells and actively facilitate glandular secretion.

OBJECTIVES

To determine if myoepithelial cells are increased in the bronchial submucosal glands of patients with fatal asthma.

METHODS

Autopsied lungs from 12 patients with fatal asthma (FA), 12 patients with asthma dying of non-respiratory causes (NFA) and 12 non-asthma control cases (NAC) were obtained through the Prairie Provinces Asthma Study. Transverse sections of segmental bronchi from three lobes were stained for mucus and smooth muscle actin and the area fractions of mucous plugs, mucous glands and myoepithelial cells determined by point counting. The fine structure of the myoepithelial cells was examined by electron microscopy.

RESULTS

FA was characterised by significant increases in mucous gland (p = 0.003), mucous plug (p = 0.004) and myoepithelial cell areas (p = 0.017) compared with NAC. When the ratio of myoepithelial cell area to total gland area was examined, there was a disproportionate and significant increase in FA compared with NAC (p = 0.014). Electron microscopy of FA cases revealed hypertrophy of the myoepithelial cells with increased intracellular myofilaments. The NFA group showed changes in these features that were intermediate between the FA and NAC groups but the differences were not significant.

CONCLUSIONS

Bronchial mucous glands and mucous gland myoepithelial cell smooth muscle actin are increased in fatal asthma and may contribute to asphyxia due to mucous plugging.

The current status of materials for posterior composite restorations: the advent of low shrink

Polymerization contraction, and the stresses associated with this, have presented problems with resin composite materials, particularly when used to restore cavities in posterior teeth. This paper summarizes the problems associated with polymerization contraction and examines methods used to overcome this, in particular, by the use of materials which have reduced percentage contraction when compared with traditional materials.

CLINICAL RELEVANCE

Use of a material with reduced polymerization contraction should lead to simpler restoration placement.

Comparison between phytoestrogens and estradiol in the preventionof atheroma in ovariectomized cholesterol-fed rabbits

OBJECTIVES

There is increasing interest in the role of complementary and alternative medicines for the treatment of menopause-related problems. This study compared the preventive effect on atheroma formation of a commercially available mixed phytoestrogen concentrate with that of estradiol.

METHODS

An ovariectomized cholesterol-fed rabbit model of atheroma formation was used. Rabbits were ovariectomized before the commencement of the 12-week treatment period. There were two control groups. Control Group 1 received isoflavone-free rabbit chow whilst Control Group 2 received 1% cholesterol-enriched isoflavone-free rabbit chow. Rabbits in Group 3 received 1% cholesterol-enriched isoflavone-free rabbit chow plus a 500 mg tablet containing a concentrated extract of Trifolium pretense (red clover). Rabbits in Group 4 received 1% cholesterol-enriched isoflavone-free rabbit chow plus a 0.5 mg tablet of oral estradiol. Atheroma formation was measured by, first, calculation of the area of atheroma on the intimal surface, and, second, measuring the cholesterol content in the aorta.

RESULTS

There were no significant differences in serum cholesterol between the cholesterol-fed control Group 2 and the treatment Groups 3 and 4. However, there was significantly less staining for atheroma and significantly less cholesterol accumulation in the aorta in Group 4 (estradiol-treated) rabbits compared with either control Group 2 or Group 3 (phytoestrogen-treated) rabbits.

CONCLUSION

In this study, only estradiol was shown to have a significant protective effect against atheroma formation.

Optimizing the encounter rate in biological interactions: Ballistic versus Lévy versus Brownian strategies

Bartumeus et al. [Phys. Rev. Lett. 88, 097901 (2002)] compared the efficiency of a Lévy random walk predator strategy with a Brownian random walk strategy in a periodic one-dimensional domain with nonrevisitable moving targets. Their findings from numerical simulations conclude that "a Lévy search strategy is the best option in some, but not all, cases for a random search process." Using the same methodology, we show that the simplest random search strategy of all, ballistic motion in a random direction, outperforms a Lévy strategy in almost every case. We further show that, in the small set of cases where the ballistic strategy is not optimal, the periodic model does not capture the more realistic nonperiodic case. In the nonperiodic case, the ballistic strategy again outperforms the Lévy strategy.