Isolated human and rabbit eye: Models of corneal toxicity

Human and rabbit isolated eyes were compared, not in order to propose yet another test, but to explore the boundaries of the rabbit isolated cornea as a model for primary damage to human cornea. Changes in corneal thickness and in epithelial morphology were followed on recovery from cold-induced oedema and after exposure to the test chemicals. There was no statistical difference between control human and rabbit eyes in recovery from severe oedema. The effects of exposure to allyl alcohol, Arlagard E, NaOH (1 N), NaCl, sodium lauryl sulphate (2%) and Tween-20 were similar in human and rabbit eyes. Acetone, ethanol and glycerol had opposed-sign effects on corneal thickness in human and rabbit. From the small number of substances tested it can be concluded qualitatively that stored rabbit eyes behave in a manner similar to freshly isolated rabbit eyes, and that substances in which penetration depends on surface properties of the cornea may have species-specific effects.

Distribution of sialic acids on mucins and gels: a defense mechanism

Moist mucosal epithelial interfaces that are exposed to external environments are dominated by sugar epitopes, some of which (e.g., sialic acids) are involved in host defense. In this study, we determined the abundance and distribution of two sialic acids to assess differences in their availability to an exogenous probe in isolated mucins and mucous gels. We used atomic force microscopy to obtain force maps of human preocular mucous and purified ocular mucins by probing and locating the interactions between tip-tethered lectins Maackia amurensis and Sambucus nigra and their respective receptors, α-2,3 and α-2,6 N-acetylneuraminic (sialic) acids. The rupture force distributions were not affected by neighboring sugar-bearing molecules. Energy contours for both lectin-sugar bonds were fitted to a two-barrier model, suggesting a conformational change before dissociation. In contrast to data from purified mucin molecules, the preocular gels presented numerous large clusters (19,000 ± 4000 nm(2)) of α-2,6 sialic acids, but very few small clusters (2000 ± 500 nm(2)) of α-2,3 epitopes. This indicates that mucins, which are rich in α-2,3 sialic acids, are only partially exposed at the surface of the mucous gel. Microorganisms that recognize α-2,3 sialic acids will encounter only isolated ligands, and the adhesion of other microorganisms will be enhanced by large islands of neighboring α-2,6 sialic acids. We have unveiled an additional level of mucosal surface heterogeneity, specifically in the distribution of pro- and antiadhesive sialic acids that protect underlying epithelia from viruses and bacteria.

Signalling of DNA damage and cytokines across cell barriers exposed to nanoparticles depends on barrier thickness

The use of nanoparticles in medicine is ever increasing, and it is important to understand their targeted and non-targeted effects. We have previously shown that nanoparticles can cause DNA damage to cells cultured below a cellular barrier without crossing this barrier. Here, we show that this indirect DNA damage depends on the thickness of the cellular barrier, and it is mediated by signalling through gap junction proteins following the generation of mitochondrial free radicals. Indirect damage was seen across both trophoblast and corneal barriers. Signalling, including cytokine release, occurred only across bilayer and multilayer barriers, but not across monolayer barriers. Indirect toxicity was also observed in mice and using ex vivo explants of the human placenta. If the importance of barrier thickness in signalling is a general feature for all types of barriers, our results may offer a principle with which to limit the adverse effects of nanoparticle exposure and offer new therapeutic approaches.

Effects of calcium-fortified ice cream on markers of bone health

Premenopausal women with low calcium intakes consumed calcium-fortified ice cream daily for 28 days. Bone markers, NTX, CTX and PTH decreased significantly by 7 days, with some evidence of a calcium dose-dependent effect. Bone marker responses were observed within 1 h of consuming ice cream. Body weight remained constant over 28 days.

INTRODUCTION

Dietary calcium is important for lifelong bone health. Milk is a good source of bioavailable calcium, but consumption has declined among young adults. The aims were to determine whether calcium-fortified ice cream, a palatable source of calcium, produces significant, sustainable changes in bone turnover markers and parathyroid hormone (PTH) in premenopausal women with calcium intake below recommended UK levels.

METHODS

Eighty women, ages 20-39 years (calcium intake <750 mg/day) were randomised to consume lower saturated fat/sugar ice cream containing 96, 244, 459 or 676 mg calcium daily for 28 days. Urinary NTX/Cr, serum CTX, PINP, 1,25D and PTH were measured (baseline, days 1, 7 and 28). Acute changes in CTX and PTH were measured over 5 h (n = 29 women).

RESULTS

There were significant mean decreases by 7 days in NTX/Cr, CTX, PTH and 1,25D and increases in PINP (one sample t tests), with a significant dose-dependent effect on CTX analysis of covariance. Only CTX remained suppressed at 28 days. Serum CTX and PTH decreased within 1 h. Body weight did not change significantly between baseline and 28 days.

CONCLUSIONS

Daily consumption of calcium-fortified ice cream by premenopausal women may significantly reduce levels of the bone resorption marker serum CTX, without stimulating weight gain. The ice cream could be incorporated into the diet to replace low-calcium snacks and thus help individuals with habitually low calcium intakes to meet recommended intakes. The 244 mg calcium preparation would provide more than a quarter of the UK daily recommended nutrient intake for premenopausal women.

Dual diagnosis competency among addiction treatment staff: Training levels, training needs and the link to retention

BACKGROUND

Dually diagnosed clients are described as one of the most challenging treatment populations, often leading to staff frustration, helplessness and negative attitudes. As yet it is unclear whether dual diagnosis (DD)-specific competency and therapeutic optimism among staff are related to client outcomes.

METHODS

The study used a 3-month follow-up design involving 124 DD clients starting treatment at 6 UK addiction services. Practitioners (n = 46) treating these clients were assessed regarding their DD specialisation levels. Cox regression analyses were performed to examine predictors of clients' 3-month retention rates.

RESULTS

Staff reported a median of 7 years work experience with DD clients, and 80% had received co-morbidity-specific training. Practitioners provided high average ratings on both the DD competency and the therapeutic optimism scale. Nevertheless, 78% of the sample indicated additional support needs in dealing with this client group. Higher levels of DD competencies among staff predicted better client retention.

CONCLUSION

The increased provision of support packages for practitioners is vital for improving competency levels in dealing with DD clients, which in turn may lead to improved client outcomes.

The diagnostic efficacy of fine-needle aspiration using cytology and culture in tuberculous lymphadenitis

OBJECTIVE

To retrospectively assess the diagnostic efficacy of fine-needle aspiration (FNA) using cytological and microbiological examinations in tuberculous lymphadenitis.

METHODS

Patients with tuberculous lymphadenitis treated at St Mary's Hospital, London, between January 2001 and June 2007 were identified. The cytological and microbiological reports of 97 patients were found. The criteria for a definite diagnosis of tuberculous lymphadenitis were based on a compatible clinical history, tuberculin positivity and either an indicative cytological result or positive culture.

RESULTS

In 77 of the 97 (79%) cases, FNA cytology showed evidence of a tuberculous process. In 65 cases, Mycobacterium tuberculosis was cultured from the aspirates, and 54 of these 65 cases showed corresponding cytological evidence of a tuberculous process; 23 cases were diagnosed by cytology but not microbiology, while 11 cases were diagnosed by microbiology but not cytology.

CONCLUSION

Cytological and microbiological results appeared to correlate well, but each also gives an exclusive diagnosis. When combining both modalities, the diagnostic efficacy of FNA rises to 91%. A definitive microbiological diagnosis was achieved in 67% of cases and provided information on drug susceptibility. We conclude that samples should be provided for both cytological and microbiological examination when using FNA to diagnose possible tuberculous lymphadenitis.

Genetic Susceptibility as a Possible Risk Factor for Breast Cancer

Background: Established risk factors for breast cancer (BC) only explain 25% to 47% of BC incidence. The Gail model is commonly used to assess BC risk and determine eligibility for prevention trials. Unfortunately, it has a discriminatory accuracy of 58% at the individual level. A greater understanding of BC risk factors is needed to offer improved risk stratification and prevention. It is plausible that BC risk may be related to deficiencies or abnormalities in DNA repair and cell cycle checkpoints because of their importance in maintaining genomic integrity. Recent epidemiologic studies support this hypothesis. In this pilot project, the bleomycin mutagen sensitivity assay (MSS), a measure of genetic susceptibility was performed on women of low, intermediate, and high risk based on commonly used risk models to determine if there was any correlation between MSS and established BC risk factors.Methods: Women in the Prevention Clinic at RPCI consented to donate blood for this study as part of the Data Bank and BioRepository (DBBR). Gail and Claus Models were calculated using CancerGene. Women were stratified into three groups low (&lt;20%), intermediate (20%-35%), and high (&gt; 35%) lifetime BC risk. For logistic regression analysis, women were grouped into low risk (&lt;20%) and high risk (≥20%). MSS in blood lymphocytes were performed at LCCC using fresh blood samples. The mean values of MSS were compared between low, intermediate, and high risk groups using Wilcoxon-Mann-Whitney tests. Multivariate logistic regression was used to analyze the relationship between BC risk groups and MSS.Results: A total of 78 women were enrolled in the study. MSS were performed on 70 blood samples and 67 had evaluable slides. There were 30, 26 and 11 women in the low, intermediate, and high risk groups respectively. The mean age was 49.1 years. There was no statistical difference between the three groups with respect to age, race, menopausal status, proportion of patients with a family history of BC or another cancer, and smoking status (never, former, or current). The mean MSS score was not significantly different among the three risk groups: mean ±SD = 0.86±0.37, 0.84±0.37 (p=0.565), and 0.76+0.44 (0.361) for low, intermediate and high risk groups respectively. Spearman correlation revealed that MSS score did not correlate with Gail lifetime BC risk score (r=-0.054, p=0.668) or Claus model-10 year risk score (r=-0.057, p=0.722). Using the median in low risk women as a cut point, when women who had higher MSS score were compared with women had lower MSS score, the adjusted OR was 1.16 (95% CI, 0.29 to 4.57), adjusted for age, race, smoking status, BMI and menopausal status. When the MSS score were categorized into quartiles, no significant dose-response relationship was observed.Conclusions: In this pilot study, there was no correlation between commonly used breast cancer risk assessment models based on hormonal, family and biopsy history and the MSS in our study population. Previous case-control studies have consistently shown that MSS is significantly associated with BC risk. The lack of correlation between mutagen sensitivity and Gail or Claus risk score suggests that mutagen sensitivity may measure the host susceptibility factors that are not considered by Gail or Claus risk models.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6067.

Real-time sonography of orbital tumours, Colour Doppler characterization: initial experience

Fifty-seven patients with orbital tumours were examined with 3.5 MHz and 5 MHz real-time sector sonography. The lesions were evaluated for their echomorphology, relationship to anatomical structures of the orbit, and extra-orbital extension. Twenty-two patients were further evaluated by Colour Doppler Flow Imaging (CDFI). The lesions were located to four compartments, namely intraocular, intraconal, extraconal and extraorbital. An attempt was made to provide a histological diagnosis on the basis of clinical features and sonographic morphology. Colour Doppler flow patterns in 22 patients were correlated with the presumed or proven histological diagnosis in an attempt to detect and classify any specific patterns. Real-time US is an excellent screening procedure in the evaluation of orbital mass lesions. CT/MRI should be added in selected cases where extra-orbital extension requires evaluation. CDFI of tumours still being in its infancy it seems promising and may help in providing a more precise pre-operative histological diagnosis non-invasively.

High CSF transforming growth factor beta levels after subarachnoid haemorrhage: association with chronic communicating hydrocephalus

BACKGROUND

Chronic communicating hydrocephalus is a common sequela of subarachnoid haemorrhage and develops when the flow and drainage of CSF are impaired after fibrosis in the subarachnoid space. Released by platelets into the CSF after subarachnoid haemorrhage, transforming growth factor (TGF)beta1/beta2 are potent fibrogenic agents that may promote post-haemorrhagic fibrosis and chronic communicating hydrocephalus.

METHODS

Temporal changes in total (latent plus active) TGFbeta1/beta2 CSF levels of post-haemorrhage patients developing acute hydrocephalus were measured using ELISA to discover if titres were higher in patients that subsequently developed chronic communicating hydrocephalus, compared with those that did not.

RESULTS

Mean (SD) CSF levels of total TGFbeta1 were 97 (42) pg/ml and total TGFbeta2 were 395 (39) pg/ml in control patients with (non-haemorrhagic) hydrocephalus. For days 1-5 post-subarachnoid haemorrhage (dph), levels of 1427 (242) pg/ml and 976 (191) pg/ml were seen for total TGFbeta1 and TGFbeta2, respectively. Beyond 5 dph, total TGFbeta1/beta2 levels declined but remained significantly elevated (p<0.01) above control patient values for at least 19 dph. Haemorrhagic patients that went on to develop chronic communicating hydrocephalus had significantly higher levels of total TGFbeta1 (p<0.01) and TGFbeta2 (p<0.05) between 1 and 9 dph, compared with those of haemorrhagic patients that did not.

CONCLUSIONS

Acutely measured levels of TGFbeta1/beta2 in the CSF of patients with subarachnoid haemorrhage are thus potential prognostic biomarkers for the subsequent development of chronic communicating hydrocephalus, indicating likely dependency on CSF shunting.