Microfluidic sedimentation cytometer for milk quality and bovine mastitis monitoring

We report a rapid, low-cost, portable microfluidic sedimentation cytometer (SeCy) for assessing the somatic cell count and fat content of milk in 15 min using a “sample-in, answer-out” approach. The system consists of 12 independent microfluidic devices, essentially flattened funnel structures, fabricated on the footprint of a single plastic compact disc (CD). Each funnel structure holds 150 μL of milk, has an inlet for milk filling and an outlet for air to escape, and ends in a narrow, closed-end microfluidic channel that facilitates packing of the cells into a column whose length is proportional to cell count. The closed-end channel provides accurate cell counts over the range 50,000–>3,000,000 cells per mL. The assay separates cells and fat globules based on their densities (by differential sedimentation), concentrating white cells in the closed-end channel near the outer rim of the CD for estimation of total “cell pellet” volume, while fat globules move toward the center of disc rotation, forming a fat “band” in the funnel. After adding milk to two or more microfluidic devices, the CD is loaded onto a custom-built reader unit that spins the disc for 15 min. Two low-cost microscopes in the reader image the centrifuged cell pellet and the fat band, providing a sufficiently accurate cell count to diagnose mastitis and measuring fat content as an indication of health and nutritional status.     

Amygdala damage affects event‐related potentials for fearful faces at specific time windows

The amygdala is known to influence processing of threat‐related stimuli in distant brain regions, including visual cortex. The time‐course of these distant influences is unknown, although this information is important for resolving debates over likely pathways mediating an apparent rapidity in emotional processing. To address this, we recorded event‐related potentials (ERPs) to seen fearful face expressions, in preoperative patients with medial temporal lobe epilepsy who had varying degrees of amygdala pathology, plus healthy volunteers. We found that amygdala damage diminished ERPs for fearful versus neutral faces within the P1 time‐range, ∼100–150 ms, and for a later component at ∼500–600 ms. Individual severity of amygdala damage determined the magnitude of both these effects, consistent with a causal amygdala role. By contrast, amygdala damage did not affect explicit perception of fearful expressions nor a distinct emotional ERP effect at 150–250 ms. These results demonstrate two distinct time‐points at which the amygdala influences fear processing. The data also demonstrate that while not all aspects of expression processing are disrupted by amygdala damage, there is a crucial impact on an early P1 component. These findings are consistent with the existence of multiple processing stages or routes for fearful faces that vary in their dependence on amygdala function. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.     

Psychological factors contributing to perceptions pain intensity after acute orthopaedic injury

Psychological factors are capable of influencing an individual's perception of pain and may mediate the evolution from acute to chronic pain. Personality characteristics, such as alexithymia and anxiety sensitivity, can also influence perception of pain by somatising psychological distress associated with acute pain. The aim of this study was to understand if alexithymia and anxiety sensitivity interact with psychological distress at an early stage of recovery from orthopaedic injury, to accentuate perception of pain intensity and potentially mediate the development of chronic pain disorder. 62 patients who had recently suffered orthopaedic injury completed the British Pain Society Pain Rating Scale plus the Hospital Anxiety and Depression Scale, as well as measures of alexithymia and anxiety sensitivity. Pain intensity correlated with each of the psychological measures but a regression analysis found that only depression, in combination with anxiety sensitivity, contributed to a significant amount of the variance in pain scores. The authors suggest that early screening after orthopaedic injury could identify those vulnerable to developing persisting pain disorders. This could lead to effective early intervention using psychological methods of pain management to reduce the risk of acute pain evolving into a chronic pain disorder.     

The use of a hysteroscopic resectoscope for repeat evacuation of retained products of conception procedures: a case series

The blind nature of the surgical management of retained products of conception allows for a significant risk of uterine perforation or the need for repeat evacuation and subsequent morbidity due to a failed procedure. These risks may be increased postpartum or at a repeat surgical procedure. We present a case series of five patients with clinical, sonographic, or histological diagnosis of retained products of conception following either failed surgical evacuation or postpartum. All were treated surgically without complication using the loop of a saline hysteroscopic resectoscope to allow removal under direct vision of retained tissue.     

Systematic Review: Helping the Young to Understand the Old. Teaching Interventions in Geriatrics to Improve the Knowledge,Skills, and Attitudes of Undergraduate Medical Students

It is unclear whether geriatrics‐specific educational interventions lead to improvement in students' knowledge, skills, and attitudes and whether successful interventions possess any consistent features. This review examines the effect of educational interventions on undergraduate knowledge, skills, and attitudes in geriatric medicine and concludes that a wide range of innovative designs have the potential to improve each of these parameters, although evidence of interventions that improve student skills is lacking, and further research is necessary to confirm the efficacy of specific teaching strategies in geriatrics.     

RhD variant caused by an in‐frame triplet duplication in the RHD gene

BACKGROUND: The RHD gene is highly polymorphic and a large number of D variants have already been detected. Several mechanisms are involved in the origin of D variants. In‐frame deletions, resulting in a single‐amino‐acid deletion, have been described associated with RhD and RhCE variants. No in‐frame duplications and/or insertions have been reported in the RH genes to date. STUDY DESIGN AND METHODS: Blood samples from a Brazilian blood donor and his sister were serologically tested with routine anti‐D reagents and anti‐D panels (ALBAclone advanced partial D typing kit, Alba Bioscience Limited; and D‐Screen, Diagast), followed by molecular biology techniques, RHD polymerase chain reaction with sequence‐specific priming and sequencing. RESULTS: Samples tested negative with routine immunoglobulin M (IgM) anti‐D reagents and positive with IgG anti‐D, which detect weak D cells. The pattern of results with anti‐D panels did not correspond to any described before. A 3‐bp in‐frame duplication within Exon 1 (c.75_77dupTCT), resulting in the duplication of leucine 26 (p.Leu26dup), was identified in the two samples. CONCLUSION: We report the first RhD variant associated with a 3‐bp in‐frame duplication in the RHD gene, predicted to be located within the RhD protein transmembrane domain that might be expected to result in a weak‐D–like phenotype, concordant with serologic findings.     

Characterization Based on the 56-Kda Type-Specific Antigen Gene of Orientia tsutsugamushi Genotypes Isolated from Leptotrombidium Mites and the Rodent Host Post-Infection

Characterization of the 56-kDa type-specific antigen (TSA) genes of Orientia tsutsugamushi (OT) from three naturally infected, laboratory-reared mite colonies comprising three species (Leptotrombidium deliense [Ld], Leptotrombidium imphalum [Li], and Leptotrombidium chiangraiensis [Lc]) has revealed the presence of single and coexisting OT genotypes found in individual chiggers. The Karp genotype was found in all of the chiggers examined, whereas Gilliam and UT302 genotypes were only observed in combination with the Karp genotype. From analysis of these OT genotypes after transmission from chiggers to mice it was determined that with the Lc and Li mites, the OT genotype composition in the rodent spleens post-infection had not changed and therefore resembled that observed in the feeding chiggers. However, only the Karp genotype was found in rodents after feeding by Ld chiggers carrying Karp and Gilliam genotypes. The current findings reveal a complex association among the host, pathogen, and vector.