The health of immigrant children who live in areas with high immigrant concentration.

OBJECTIVES: Our objective is to contribute to the literature regarding the association between immigrant children's health, their ethnicity and their living in neighbourhoods with a high ethnic concentration of one's own ethnicity. Using data from families from five ethnic groups who all immigrated to Vancouver metropolitan region in Canada, our research question asks: How ethnicity, ethnic concentration and living in a neighbourhood with others of the same ethnic background contribute to the health of immigrant children? DESIGN: Two data sets are integrated in our study. The first is the New Canadian Children and Youth Study, which collected original data from five ethnic groups who immigrated to metropolitan Vancouver. The second data set, from which we derived neighbourhood data, is the Canadian census. The dependent variable is health status as reported by the parent. Independent variables are at both the individual and neighbourhood levels, including ethnicity, sex and the percentage of people living in the neighbourhood of the same ethnic background. Analysis was completed using hierarchical linear modelling. RESULTS: Children (n = 759) from 24 neighbourhoods were included in the analyses. Health status varied by ethnicity and ethnic concentration, indicating the heterogeneity of immigrant populations. CONCLUSION: With the lack of research on the health of immigrant children and youth living in ethnic concentrations, our findings make an important contribution to understanding the influences on the well-being of immigrant populations.

Bridging the research gap: aboriginal and academic collaboration in FASD prevention. The Healthy Communities, Mothers and Children Project.

OBJECTIVES: The objective was to assist with the prevention of Fetal Alcohol Spectrum Disorder through a participatory research approach involving local women and health care workers. Our interest was in understanding how well communities could develop culturally appropriate methods of helping women to reduce their alcohol consumption during pregnancy. STUDY DESIGN: Four geographically distant Aboriginal communities were presented with a task of adapting a standard Brief Alcohol Intervention, and in particular to develop a culturally appropriate means of using the Intervention with women in the community. METHODS: Academic and Aboriginal community researchers worked together in partnership, using a participatory action research approach to address alcohol use during pregnancy. RESULTS: The outcome of the project was the design of four differing models of culturally appropriate community interventions designed to support vulnerable women in their childbearing years. The intervention models developed by the four communities have five core characteristics: (1) identification of women at risk; (2) assessment of the woman's drinking/ drug use; (3) provision of information to the women; (4) delivery method facilitates the decision to adopt healthier behaviors; and (5) means to monitor changes. CONCLUSION: This project was considered successful in many respects: (1) each community developed a culturally-relevant prevention tool; (2) community involvement in the design lead to better understanding of its usefulness; (3) considerable knowledge exchange between academic and community partners took place; and (4) most importantly, it was found that community members can be active members in developing and implementing solutions to important public health issues.

Cholesterol sulfate accumulation in tumorigenic and nontumorigenic rat esophageal epithelial cells: evidence for defective differentiation control in tumorigenic cells.

In this study the regulation of squamous cell differentiation in several rat esophageal epithelial cell lines is examined. Nontumorigenic RE-149 cells undergo a program of squamous cell differentiation at confluence. This program of differentiation is influenced by the concentration of calcium in the medium and by the presence of retinoic acid. High calcium concentration stimulates terminal cell division, as indicated by a reduction in colony-forming efficiency, and increases the expression of the differentiated phenotype as indicated by an increase in cholesterol sulfate accumulation and cross-linked envelope formation. Retinoic acid inhibits squamous cell differentiation as both cholesterol sulfate accumulation and cross-linked envelope formation are reduced. Two tumorigenic cell lines, RE-B2 and RE-2BT, do not undergo squamous cell differentiation in vitro. High calcium concentration in the medium did not significantly reduce colony-forming efficiency or induce cross-linked envelope formation. High calcium concentration or retinoic acid had only a limited effect on the accumulation of cholesterol sulfate. RE-B2T cells exhibit high levels of cholesterol sulfate and cholesterol sulfotransferase activity. These levels appear no longer controlled by calcium or retinoic acid, indicating that the synthesis of cholesterol sulfate occurs in a constitutive manner. The altered responses of RE-2B and B2T cells to calcium and retinoic acid suggest that these malignant cells have acquired one or more defects in the control of differentiation.

Effects of bryostatins and retinoic acid on phorbol ester- and diacylglycerol-induced squamous differentiation in human tracheobronchial epithelial cells.

Previous studies have shown that normal human tracheobronchial epithelial (HBE) cells undergo squamous differentiation upon treatment with phorbol 12-myristate 13-acetate (PMA). In this study, we report that induction of this differentiation program is accompanied by an increase in the accumulation of cholesterol sulfate and in transglutaminase type I activity, two markers of squamous differentiation. Several carcinoma cell lines did not exhibit an increase in these differentiation markers after PMA-treatment and appear to have acquired a defect in the mechanism that triggers differentiation. The diacylglycerol analogue, didecanoylglycerol (diC10), was also able to induce squamous differentiation. Bryostatin 1, another activator of protein kinase C, did not induce terminal cell division or increase cholesterol sulfate accumulation or transglutaminase type I activity. Bryostatin 1 not only failed to inhibit cell proliferation and to induce differentiation but antagonized the PMA- and diC10-induced commitment to terminal differentiation. The bryostatin blocked both the PMA-induced terminal cell division as well as the expression of the two differentiation markers. Retinoids were found not to affect the PMA-induced commitment to terminal cell division but did inhibit the expression of the differentiated phenotype. Our results indicate that the bryostatins and retinoids affect the multistep process of squamous differentiation in tracheobronchial epithelial cells at two different stages.

Ecological analyses of the associations between injury risk and socioeconomic status, geography and Aboriginal ethnicity in British Columbia, Canada.

BACKGROUND: The current study examines what factors contribute to higher injury risk among Aboriginal peoples, compared to the total British Columbia (BC) population. We explore socioeconomic, geographic, and cultural factors, and combinations of these factors, that contribute to increased injury risk for Aboriginal peoples. This follows from our previously reported findings of improvements in injury risk over time for both the total and Aboriginal populations. DATA AND METHODS: We use provincial population-based linked health care databases of hospital discharge records. We identify three population groups: total BC population, and Aboriginal populations living off-reserve, or on-reserve. For each group we calculate age and gender-standardized relative risks (SRR) of injury-related hospitalization, relative to the total population of BC, for two 5-year time periods (1999-2003, and 2004-2008). We use custom data from the 2001 and 2006 long-form Censuses that described income, education, employment, housing conditions, proportion of urban dwellers, proportion of rural dwellers, and prevalence of Aboriginal ethnicity. We use multivariable linear regression to examine the associations between the census characteristics and SRR of injury. RESULTS: The best-fitting model was an excellent fit (R(2) = 0.905, p < 0.001) among the three population groups within Health Service Delivery Areas of BC. We find indicators in all three categories (socioeconomic, geographic, and cultural) are associated with disparity in injury risk. While the socioeconomic indicators (income, education, housing, employment) were shown to be highly correlated, only living in housing that needs major repair and occupational hazardousness, along with rural residence and Aboriginal ethnicity, remained in the final model. Our data show that cultural density is not associated with injury risk for Aboriginal peoples, and that living off-reserve is associated with reduced injury by improving socioeconomic and geographic conditions (compared to living on-reserve). Finally, our analyses show that Aboriginal status itself is associated with injury risk. CONCLUSIONS: Our findings confirm previous research indicating that geographical differences differentiate injury risk, including for Aboriginal populations, and that socioeconomic determinants are associated with health risks. Our analyses showing that Aboriginal status itself contributes to injury risk is new, but we can only speculate about pathway, and whether the causes are direct or indirect.

A laparoscopic approach to allograft nephrectomy and bilateral native nephrectomy: a case report.

INTRODUCTION: Laparoscopic surgery is rapidly emerging as the standard of care for a variety of urological conditions, even among patients who have undergone prior renal transplantation. We describe the technique of bilateral native nephrectomy and allograft nephrectomy by laparoscopy. CASE REPORT: A 32-year-old man with end-stage renal disease who had undergone a cadaveric renal transplant presented with chronic graft dysfunction. He had received a living donor kidney transplant with a postoperative course complicated by persistent proteinuria and refractory hypertension. Our nephrology service indicated the need for bilateral native nephrectomy and allograft nephrectomy for better blood pressure control following a second transplant. Bilateral native nephrectomy was performed following the previous reported techniques for pure laparoscopic nephrectomy. Allograft nephrectomy started by dissection of the iliac vessels to identify the vascular anastomosis. The hilum of the transplanted kidney was accessed. The renal vessels were clipped and transected. The ureter was identified and clipped. All three kidneys were removed from the abdominal cavity through a 3-cm skin incision. RESULTS: The left nephrectomy took 25 minutes and the right nephrectomy, 40 minutes. The estimated blood loss was 300 mL and the total operative time was 210 minutes. The patient had an uneventful postoperative course and was discharged on the third postoperative day. CONCLUSIONS: We demonstrate the feasibility of laparoscopic allograft nephrectomy and bilateral native nephrectomy in a transplant recipient.

Increased cholesterol sulfate and cholesterol sulfotransferase activity in relation to the multi-step process of differentiation in human epidermal keratinocytes.

In this study the synthesis of cholesterol sulfate is examined in relation to the process of squamous differentiation in normal human epidermal keratinocytes (NHEK) in culture. During the exponential growth phase, NHEK cells exhibit a relatively high colony-forming efficiency and appear undifferentiated on the basis of their morphology and expression of biochemical characteristics. At confluence, the cells undergo terminal differentiation that is characterized by the commitment to terminal cell division (reduction in colony-forming ability) and expression of the differentiated phenotype. An accumulation of cholesterol sulfate accompanies this program of differentiation. This accumulation of cholesterol sulfate parallels the increase in transglutaminase type I activity and the competence to form cross-linked envelopes, whereas it precedes the "spontaneous" formation of cross-linked envelopes. Increased cholesterol sulfotransferase activity appears to account for the increase in cholesterol sulfate. The cholesterol sulfate accumulation, as well as the increase in cholesterol sulfotransferase and transglutaminase activity, are inhibited by retinoids. However, the presence of retinoids does not prevent NHEK cells from undergoing terminal cell division at confluence. Two NHEK cell lines expressing SV40-large T antigen also undergo terminal differentiation at confluence and start to accumulate cholesterol sulfate. Two other, differentiation-defective cell lines do not exhibit an increase in cholesterol sulfate at confluence. These results show that epidermal keratinocytes in culture, like cells in the epidermis, accumulate cholesterol sulfate when undergoing squamous differentiation. This program appears to consist of a retinoid-insensitive step (commitment to terminal cell division) and a retinoid-sensitive step (expression of the squamous differentiated phenotype).

Action of phorbol esters, bryostatins, and retinoic acid on cholesterol sulfate synthesis: relation to the multistep process of differentiation in human epidermal keratinocytes.

This study examines the action of phorbol 12-myristate 13-acetate (PMA) on the synthesis of cholesterol sulfate in cultured normal and transformed human epidermal keratinocytes and assesses the antagonistic effects by retinoids and bryostatins on PMA action in relation to the multistep program of squamous differentiation. Treatment of normal human epidermal keratinocytes (NHEK) with PMA induces terminal cell division (irreversible growth-arrest) and causes a time- and dose-dependent increase in the incorporation of Na2(35)SO4 into cholesterol sulfate, a marker for squamous cell differentiation. This stimulation in sulfate incorporation appears specific for cholesterol sulfate and is due to increased levels of cholesterol sulfotransferase activity. The increase in cholesterol sulfate accumulation parallels the increase in transglutaminase type I, another marker for squamous differentiation. Several transformed NHEK cell lines do not exhibit increased levels of cholesterol sulfate and transglutaminase type I activity after PMA treatment, indicating that they acquired defects in the regulation of squamous differentiation. Bryostatins 1 and 2, and several diacylglycerol analogues neither inhibit cell proliferation nor increase cholesterol sulfate synthesis or transglutaminase activity, indicating that these agents do not induce terminal differentiation. In contrast, the bryostatins block the increase in cholesterol sulfate and transglutaminase activity as well as the commitment to terminal cell division by PMA. Bryostatin 1 inhibits the commitment to terminal cell division and the accumulation of cholesterol sulfate significantly even when added 8 h after PMA administration. Retinoids inhibit cholesterol sulfate accumulation and the increase in transglutaminase activity by PMA but do not affect the commitment to terminal cell division. In summary, phorbol esters induce in NHEK cells a program of squamous differentiation. This process of differentiation consists of the commitment to terminal cell division and expression of a squamous phenotype. Expression of this phenotype is accompanied by an accumulation of cholesterol sulfate and increased cholesterol sulfotransferase activity. Bryostatins 1 and 2 and retinoic acid affect this differentiation process at different stages.

Pathways of differentiation of airway epithelial cells.

The question being examined is whether one or more morphologically distinct cell types can be identified in the conducting airways of adult rabbits possessing stem cell functions. The term "stem cell" is used to denote cells with extensive self-replicating potential and the ability to produce differentiated progeny. According to various models of cell renewal in the conducting airways that have been proposed over the years, two different cell types have to be regarded as primary candidates for the stem cell: basal cells and some type of secretory cells. The question is complicated by the fact that significant differences exist between species in the distribution and morphological characteristics of airway cell types. In addition, different airway segments may or may not be occupied by different populations of stem cells. Previously, investigators have addressed the problem by studying normal cell regeneration or injury induced cell regeneration in vivo in the whole animal. We decided to attempt a different approach, namely, to separate specific cell types and to study the proliferation and differentiation capacity of such cell isolates using in vitro and in vivo cell culture techniques. Our studies lead us to conclude that the conducting airways of adult rabbits contain at least two distinct cell populations endowed with stem cell potential, namely basal cells and bronchiolar Clara cells. From that it follows that the trachea and bronchi, on one hand, and the bronchioles, on the other hand, are occupied by two different stem cell populations governing renewal of the epithelial lining.

The effect of nitrogen diffusion hardening on the surface chemistry and scratch resistance of Ti-6A1-4V alloy.

Modular, head-stem, mixed-metal connections are susceptible to mechanically mediated electrochemical interactions. Any attempt to improve the performance of these connections should center around increasing their resistance to mechanical damage, particularly the titanium alloy (Ti64). This study investigated the effect of a nitrogen-diffusion-hardening process on Ti64, with specific reference to changes in composition, chemistry, electrochemistry and its ability to resist and/or repassivate scratch damage. The nitrogen-diffusion-hardened Ti64 alloy had TiN and TiNO complexes at the immediate surface and sub-surface layers. The diffusion-hardened samples also had a deeper penetration of oxygen compared to regular Ti64 alloy samples. The electrochemical impedance spectroscopy data corroborated the increased thickness of the barrier oxide on the diffusion-hardened samples. The nitrogen-diffusion-hardened samples were more resistant to scratch damage and repaired/repassivated faster after such damage. The results suggest that the nitrogen-diffusion-hardened titanium alloy should exhibit increased resistance to mechanical-electrochemical interactions in mixed-metal modular interfaces in total hip prostheses.

Surface topography, corrosion and microhardness of nitrogen-diffusion-hardened titanium alloy.

Mechanical-electrochemical interactions accelerate corrosion in mixed-metal modular hip prostheses. These interactions can be reduced by improving the modular component machining tolerances or by improving the resistance of the components to scratch or fretting damage. Wrought cobalt-alloy (CoCrMo) is known to have better tribological properties compared to the titanium alloy (Ti64). Thus, improving the tribological properties of this mixed-metal interface should center around improving the tribological properties of the Ti64 alloy. This study used scanning probe microscopy (contact, tapping and phase contrast mode), scanning electron microscopy, corrosion testing, and microhardness testing to determine the effect of a nitrogen-diffusion hardening process on the surface morphology, electrochemistry and surface hardness of the Ti64 alloy. The nitrogen-diffusion-hardened titanium alloy samples (N-Ti64) had a more pronounced grain structure, more nodular surface, and significantly (P<0.01) higher mean roughness values than the control-Ti64 samples. The N-Ti64 samples also exhibited at least equivalent corrosion behavior and a definite increase in surface hardness compared to the control Ti64 samples. The equivalent corrosion behavior and improved surface hardness indicate the potential for N-Ti64 samples to resist similar and mixed-metal scratch and fretting damage. The use of N-Ti64 as opposed to control-Ti64 may therefore reduce the occurrence of mechanical-electrochemical degradation in mixed-metal modular total hip prostheses.

Preservative-free artificial tear preparations. Assessment of corneal epithelial toxic effects.

Scanning electron microscopy was used to evaluate the corneal epithelium of rabbit eyes after administration of two preservative-free ocular lubricants, preservative-free artificial tear-1 (Hypotears PF) and preservative-free artificial tear-2 (Refresh), and 0.02% benzalkonium chloride. Animals were randomly assigned to either mild or exaggerated use regimens. A quantitative rating system was used to assess epithelial damage. With mild use, scanning electron microscopy revealed normal epithelial morphologic characteristics for both preservative-free artificial tear solutions (mean relative damage score, solution 1, 0.75 +/- 0.16; solution 2, 1.02 +/- 0.23), which were not significantly different from eyes treated with phosphate-buffered saline (1.38 +/- 0.38) or a mild dosage regimen of 0.02% benzalkonium chloride (1.20 +/- 0.12). Exaggerated use with preservative-free artificial tear solutions (solution 1, 1.31 +/- 0.21; solution 2, 1.35 +/- 0.08) induced minimal damage that was not different from control eyes treated with phosphate-buffered saline (1.26 +/- 0.13). Compared with an exaggerated use of 0.02% benzalkonium chloride (4.0 +/- 0.16), both preservative-free artificial tear solutions induced significantly less epithelial damage (P = .0001). These results suggest that with frequent-dosage regimens, preservation-free artificial tear solutions-1 and -2 are free of the toxic effects associated with preserved solutions.

Effects of Vasocon-A in the allergen challenge model of acute allergic conjunctivitis.

The ophthalmic combination product of 0.05% naphazoline hydrochloride and 0.5% antazoline phosphate (Vasocon-A) was evaluated as an antiallergic agent in 100 subjects with a known allergic history to cat dander, ragweed, or bluegrass pollen. Three independent study sites were used. The allergen challenge model of acute allergic conjunctivitis was selected to assess the agent as it provided a standardized and precise way to measure drug effectiveness for this indication. In a double-masked randomized fashion, the subjects were assigned to one of three groups that received one drop of Vasocon-A in one eye and one drop of either 0.05% naphazoline (group 1), 0.5% antazoline (group 2), or placebo (group 3) in the contralateral eye. After 10 minutes, the dose of allergen shown to elicit a 2+ redness and itching reaction was instilled bilaterally. Signs and symptoms of allergic conjunctivitis were evaluated after 3, 5, and 10 minutes. Subjects were then rechallenged 2 hours after drug administration to assess the duration of action of the agents. Vasocon-A was found to significantly inhibit all five major signs and symptoms of allergic conjunctivitis: itching, redness, chemosis, lid swelling, and tearing, for more than 85% of the comparisons when compared over time with placebo, naphazoline alone, or antazoline alone. The results of this study indicate that the combination of naphazoline and antazoline was more effective in inhibiting redness than naphazoline and more effective in inhibiting itching than antazoline. These findings support the use of such a combination for the treatment of allergic conjunctivitis.

Evidence for the ability of hippocampal neurons to develop acute tolerance to ethanol in behaving rats.

BACKGROUND: The cellular mechanisms underlying acute tolerance to alcohol are unclear. This study aimed to determine whether hippocampal neurons have the ability to develop acute tolerance to alcohol in behaving rats. METHODS: Intrahippocampal microdialysis was performed in freely behaving rats, and the firing of single neurons in the dialysis area was recorded. The control microdialysis fluid, artificial cerebrospinal fluid (ACSF), was replaced with 1 M ethanol in ACSF for a 30 min period. One hour later, the ethanol perfusion was repeated. To test the functional integrity of the microdialysis probe in situ, each microdialysis session was completed with recording the effect of a 10-20 min perfusion of 500 microM N-methyl-D-aspartate (NMDA). The extracellular concentration profile of ethanol during intrahippocampal microdialysis with 1 M ethanol was estimated in a separate study in anesthetized rats. The ethanol content was measured in tissue slices surrounding the probe with gas chromatography (GC), and the generated data were analyzed with a mathematical model for microdialysis to estimate the concentration of ethanol at the recording site. RESULTS: The predominant effect of the first intrahippocampal microdialysis with ethanol was a decrease in firing rate in both pyramidal cells and interneurons. In contrast, such firing rate decrease did not develop during the second ethanol perfusion. Subsequent NMDA perfusion still induced robust changes in the electrical activity of the neurons. The estimated extracellular ethanol concentration at the recording site was 45-70 mM. CONCLUSION: This study revealed that hippocampal neurons have the ability to develop acute tolerance to a single exposure of clinically relevant concentrations of ethanol in behaving rats, without influences from the rest of the body.

Neglected Foreign Body, the Cause of Navicular Osteomyelitis in A Paediatric Foot: A Case Report.

INTRODUCTION: Foreign body injuries with date thorns, metal and wooden splinters are common in Middle East region, as most of it is desert. Some of the injuries lead to cellulitis or abscess formation, if neglected or improperly managed results in osteomyelitis or septic arthritis of foot structures. This is the first report of isolated navicular osteomyelitis following neglected foreign body in a paediatric foot. CASE REPORT: A 10 year old male patient presented with discharging sinus in left mid-foot 3 years after penetrating injury with wooden splinter. The diagnosis of navicular osteomelitis is confirmed with plain radio-graphs. The ultrasound of foot was done to localize the foreign bodies. Patient was treated with complete removal of foreign body (wooden splinters), surgical debridement and combination of IV and oral cloxacillin for period of 6 weeks. At 18 months follow up, patient had painless foot with no recurrence or collapse of navicular bone. CONCLUSION: The neglected foreign body can result in osteomyelitis of small bones of foot in pediatric patient. The ultrasound is more useful tool in localizing foreign bodies; those are not radio-opaque. Early and prompt diagnosis with adequate treatment of established osteomyelitis by complete removal of foreign body, curettage and antibiotics can give good results.

Structured shared decision-making using dialogue and visualization: a randomized controlled trial.

OBJECTIVE: The aim of this study is to evaluate a method, "Counseling in Dialogue" (CD), developed to increase the quality of counseling in youth mental health. Decisional conflict was used as indicator of the quality of counseling and shared decision-making. METHODS: 94 children aged 2-12 years were randomized into a CD group and a care as usual (CU) group. In a before-and-after design decisional conflict was measured using the decisional conflict scale (DCS) for parents (N=133) and the Provider Decision Process Assessment Instrument for therapists (PDPAI, N=20). 81 children had follow-up data. RESULTS: Compared with parents of the CU group, parents of the CD group reported significantly less decisional conflict after counseling (difference mothers: -0.38 (95%CI -0.56; -0.19), p<.001; fathers: -0.22 (95%CI -0.44; -0.01), p=.045). 98% of the mothers and 96% of the fathers in the CD group accepted the recommended treatment, compared to 71% (fathers) and 77% (mothers) in the CU group, p<0.05. Decisional conflict of the therapists was low in both groups after counseling (difference: -0.03 (95%CI -0.19; 0.14), p=.741). CONCLUSION: The counseling procedure significantly lowered decisional conflict of the parents and promoted the acceptance of the recommended treatment.