Evaluation of a protein microarray method for immuno-typing erythrocytes in whole blood

All donor blood samples must be tested pre-transfusion to determine the blood type of donor erythrocytes, based on the ABO typing system. Current methods of testing are well characterised, but require a number of processing steps prior to analysis. In addition, standard testing protocols require additional assays such as hepatitis C and HIV testing be performed separately. We describe and evaluate a protein microarray platform for ABO blood typing that has the potential to be a simple reliable high throughput method, with the added capability for the integration of other important pre-transfusion tests. Sixty seven donor blood samples were incubated on microarrays printed with multiple spotted replicates of blood type antigen specific antibodies. We utilised a hold-out cross validation approach, combined with Receiver Operator Characteristic (ROC) curves to define thresholds within which a sample could be defined as being of a particular blood type. The threshold values from the ROC curve analysis demonstrated an excellent ability to accurately separate samples based on ABO blood type. The results obtained when the thresholds from the training sets were applied to test sets were also very encouraging, with misclassified samples being present in only 2 of the training sets and a mean classification error of 4.28%. When the mean thresholds were applied to the 67 donor samples, 95.5% were correctly blood typed (64 of 67 samples). We have demonstrated the ability of our protein microarray platform to successfully and accurately type human whole blood samples. We believe that this flexible platform provides a strong basis for an integrated approach for combined blood typing and pathogen testing in human whole blood.     

Streptococcus mutans serotypes and collagen‐binding proteins Cnm/Cbm in children with caries analysed by PCR

Streptococcus mutans, a primary bacterium associated with dental caries, has four known clinical serotypes (c, e, fand k). Certain serotypes, the presence of multiple serotypes and strains with collagen‐binding proteins (CBP, Cnm and Cbm) have been linked with systemic disease. Evaluation of S mutans serotype distribution and caries association is needed in the United States. The purpose of this study was to evaluate the prevalence of S mutans serotypes from two cohorts of African‐American children in rural Alabama using three sample types (saliva, plaque and individual S mutans isolates) by PCR detection for association with caries. Detection of CBP was also performed by PCR. In total, 129 children were evaluated and overall prevalence of serotypes were: serotype c(98%), e(26%), f(7%) and k(52%). Serotype c was statistically associated with higher caries scores in older children (P < 0.001) and serotype k was statistically more likely in females (P = 0.004). Fourteen per cent of children had CBP. Thirteen S mutans isolates from five children tested positive for both CBP. This study is the first to report on the prevalence of S mutans serotypes in a US population using the PCR‐based approach. The frequency of serotype k in this study is the highest reported in any population, illustrating the need for further study to determine the prevalence of this clinically relevant serotype in the US. This is the first study to report S mutans isolates with both Cnm and Cbm in the same strain, and further analysis is needed to determine the clinical significance of these strains.     

The association between coffee consumption and periodontitis: a cross-sectional study of a northern German population

Clinical Oral Investigations - Positive and negative influences on oral health are attributed to coffee consumption. The aim of the current study is to evaluate the association between coffee...     

Gender and national origin differences in healthcare utilization among U.S. Immigrants from Mexico,China, and India

Objectives: To examine gender and national origin differences in the healthcare utilization of immigrants from the three largest populations in the U.S. today (Mexico, China, and India) and to determine if barriers to utilization operate similarly across groups.

Methods: The analysis uses nationally-representative data from the 2003 New Immigrant Survey (NIS) to compare utilization behaviors among legal permanent residents from Mexico, China, and India (n?=?2244). Conceptually, the study draws on Andersen’s Behavioral Model to hypothesize gender and national origin differences in utilization based on factors that might predispose, enable, or necessitate healthcare. Multivariate logistic regression models are used to predict the odds of having seen a doctor in the past year and to test whether obstacles to utilization differ across immigrant groups.

Results: Chinese immigrants are less likely than Mexican and Indian immigrants to have seen a doctor in the past year, a finding that is largely driven by a lack of health insurance. Female immigrants are more likely than males to have done so, despite having fewer resources that enable access to care (e.g. income, English proficiency). Moreover, the relationship between gender and utilization is moderated by English language proficiency: among immigrants with low levels of proficiency, women are significantly more likely than men to have seen a doctor in the past year, while no difference exists between men and women who are proficient in English. This pattern is most evident among Mexican, and to a lesser extent, Indian immigrants.

Conclusions: Barriers to immigrant healthcare utilization vary by gender and national origin. Research will need to continue documenting such variation in order to better inform policy makers and health practitioners of potential solutions for improving health outcomes in increasingly diverse immigrant communities.