Survey on pretransfusion testing

BACKGROUND: Hospitals and blood centers throughout the United States use a variety of reagents and methods to perform pretransfusion testing. A survey was developed to determine the reagents and methods in use and their relative prevalence in different work settings. STUDY DESIGN AND METHODS: A national survey on pretransfusion testing was conducted. Surveys were distributed to state and regional blood bank associations, which then distributed them to hospitals and blood centers within their region. In most instances, the blood centers distributed the survey to the local hospitals. Completed surveys were returned to the authors for review, and all information was entered into a database for analysis. RESULTS: Analysis of the data shows that the majority of blood banks use monoclonal reagents for ABO testing and monoclonal-polyclonal blended reagents for Rh testing. The data show that anti-IgG and polyclonal antihuman globulin reagents are used almost equally for antibody screening (detection) tests and that most blood banks use a three-cell antibody-screening test. Slightly more than 50 percent of hospitals use an immediate-spin crossmatch in the absence of unexpected antibodies. CONCLUSION: A number of approved reagents and methods are used by blood bank laboratories for pretransfusion testing. Facility size (number of beds) and type tend to influence the choice of methods and reagents employed. This survey provides an opportunity for blood bank laboratories to compare their current practices with those of their peers.     

SELECTIVE ENDOSCOPY IN MANAGEMENT OF INGESTED FOREIGN BODIES OF THE UPPER GASTROINTESTINAL TRACT: IS IT SAFE?

During a four-year period, 308 patients presented following ingestion of foreign bodies. Ingestion was accidental in 272 cases (88.3%) and deliberate in the remainder. Symptoms at presentation included dysphagia, odynophagia, nausea and vomiting, chest pain and pharyngeal discomfort. Sixty-eight patients were asymptomatic. A policy of expectant management and selective endoscopy was employed. Following initial assessment 202 patients (65.6%) were discharged without treatment, 30 (9.7%) of whom were later reviewed as outpatients and did not require admission. Forty-nine patients (16%) were admitted for treatment; 27 had oesophagoscopy, five bronchoscopy and two had foreign body extraction with direct laryngoscopy. In nine patients who were endoscoped, no foreign body was identified. Twenty-seven others were referred to the otorhinolaryngology service in another hospital. There were no deaths in the group and morbidity was 1.2%. We conclude that a policy of selective endoscopy is safe and effective in the management of patients following ingestion of foreign bodies.     

Cellular trafficking of nicotinic acetylcholine receptors

Nicotinic acetylcholine receptors （nAChRs） play critical roles throughout the body. Precise regulation of the cellular loca- tion and availability of nAChRs on neurons and target cells is critical to their proper function. Dynamic, post-translational regulation of nAChRs, particularly control of their movements among the different compartments of cells, is an important aspect of that regulation. A combination of new information and new techniques has the study of nAChR trafficking poised for new breakthroughs.     

Myocardial oxygen consumption in left ventricular hypertrophy and its relation to left ventricular mechanics

Alterations in left ventricular (LV) mechanics have significant effects on myocardial oxygen consumption (MV?O₂₂) as a result of changing LV pressure and dimensions. However, the effects of load alteration on MV?O₂₂ in the setting of LV hypertrophy and LV dysfunction have not been well characterized. Therefore, we examined changes in LV mechanics and MV?O₂₂ in 32 patients with varying degrees of LV hypertrophy and LV dysfunction before and after pharmacologic alteration of load. With phenylephrine or nitroglycerin-induced load alteration, changes in peak systolic meridional stress, mean systolic stress and the area of a stress-dimension loop all correlated modestly with changes in MV?O₂₂ (r = 0.66, 0.62, 0.63, respectively). However, changes in the time integral of LV ejection stress, or shortening load, were significantly correlated with changes in MV?O₂₂ (r = 0.88, p < 0.001). In particular, load reduction results in a beneficial effect on MV?O₂₂. In addition, for a given change in LV systolic pressure, changes in shortening load (38 + 3.7%) were significantly greater than changes in tension-time index (13 ± 1.4%), thus providing a sensitive marker of alteration of mechanical load.We conclude that physiologic alterations in mechanical load in normal persons as well as patients with LV hypertrophy are reflected in significant changes in the time integral of LV ejection stress. These changes in shortening load, mediated by changing LV pressure and dimension, are significantly related to changes in MV?O₂₂.     

Targeting Gonadotropin-releasing Hormone Receptor Inhibits the Early Step of Ovarian Cancer Metastasis by Modulating Tumor-mesothelial Adhesion

Ovarian cancer has a clear predilection to metastasize to the peritoneum, which represents one of the most important prognostic factors of poor clinical outcome. Gonadotropin-releasing hormone (GnRH) receptor is significantly overexpressed during the malignant progression of human ovarian cancer. Here, using lentiviral-based small interfering RNA (siRNA) technology to downregulate GnRH receptor in metastatic ovarian cancer cells, we show that GnRH receptor is an important mediator of ovarian cancer peritoneal metastasis. GnRH receptor downregulation dramatically attenuated their adhesion to the peritoneal mesothelium. By inhibiting the expression of GnRH receptor, we showed decreased expression of α2β1 and α5β1 integrin and adhesion to specific extracellular matrix (ECM) proteins. This was also associated with a reduction of P-cadherin. Furthermore, adhesion of ovarian cancer cells to different ECMs and the mesothelium were abrogated in response to β1 integrin and P-cadherin reduction, confirming that the effects were β1 integrin- and P-cadherin–specific. Using a mouse model of human ovarian cancer metastasis, we found that the inhibition of GnRH receptor, β1 integrin, and P-cadherin significantly attenuated tumor growth, ascites formation, and the number of metastatic implants. These results define a new role for GnRH receptor in early metastasis and offer the possibility of novel therapeutic targets.     

CT angiograms for lower GI bleeding: the experience of a large UK teaching hospital

IntroductionThe clinical presentation of lower gastrointestinal bleeding (LGIB) is variable in severity, cause and potential investigations. The British Society of Gastroenterology recently published LGIB guidelines, recommending CT angiography (CT-A) for haemodynamically unstable patients, defined by shock index (SI) greater than 1. The aim of this study was to assess the use and role of CT-A in diagnosing LGIB, by assessing the pickup rate of active LGIB defined by contrast extravasation or ‘blush’ and to determine any association between positive CT-A with various patient and clinical characteristics.MethodsA retrospective analysis was carried out of 4 years of LGIB admissions. Demographics, inpatient observations and use of blood products were acquired. Vital signs nearest the time of CT-A plus abnormal vital signs preceding imaging were used to calculate SI, Age SI, National Early Warning Score 2 (NEWS2) and Standardised Early Warning Score (SEWS). A consultant gastrointestinal radiologist further reviewed all consultant-reported scans.ResultsIn total, 930 patients were admitted with LGIB. Median age was 71 years and 51% were male; 179 (19.2%) patients received red blood cell transfusion and 93 patients (10%) underwent CT-A, who were older and were likely to be hypotensive and receive red cell transfusions. Following exclusions, 92 CT-As were included in the analysis. Nine (9.8%) were positive. Univariate analysis showed no association between positive CT-A and any scoring system. A multivariate analysis, including age and gender, showed association between both NEWS2 and SEWS scores with positive CT-A.ConclusionIn our analysis of the typical LGIB population, CT-A has shown relatively low pick up rate of active bleeding. CT-A clearly has a role in the investigation of LGIB, but selection remains challenging.     

Detection of meticillin‐resistant staphylococcus aureus (MRSA) colonization in newborn infants using real‐time polymerase chain reaction (PCR)

Objective: Meticillin‐resistant staphylococcus aureus (MRSA) colonization on neonatal units is a common and important clinical problem. Effectiveness of polymerase chain reaction (PCR) for detecting MRSA nasal colonization of infants was evaluated and compared to culture‐based methods. The effect of skin decolonization in affected infants was studied. Methods: Paired nasal swabs were collected from infants in our neonatal unit over a 12‐month period (September 2007–2008). Colonization with MRSA was determined with a commercially available PCR method and compared to culture. Results: A total of 696 paired nasal swabs were taken. Three infants were colonized at the beginning and were included. There were positive PCRs in 12 infants. Five infants cultured MRSA from a nasal swab at the same time. No infants were culture‐positive when PCR was negative (sensitivity 100%, specificity 99% compared to culture). PCR results were available within 24 h. Five infants were PCR+ and isolated meticillin‐sensitive Staphylococcus aureus. This organism gave a false‐positive PCR result. Two infants transferred in on broad‐spectrum antibiotics were PCR+ and negative by culture. Decolonization led to negative nasal PCR and culture in 4/5 infants to discharge. Conclusions: PCR methods are sensitive and specific for detection of MRSA colonization in newborn infants of all gestations with results 1–2 days before culture.