Tissue recovery practices and bioburden: a systematic review.

For successful transplantation, allografts should be free of microorganisms that may cause harm to the allograft recipient. Before or during recovery and subsequent processing, tissues can become contaminated. Effective tissue recovery methods, such as minimizing recovery times (<24 h after death) and the number of experienced personnel performing recovery, are examples of factors that can affect the rate of tissue contamination at recovery. Additional factors, such as minimizing the time after asystole to recovery and the total time it takes to perform recovery, the type of recovery site, the efficacy of the skin prep performed immediately prior to recovery of tissue, and certain technical recovery procedures may also result in control of the rate of contamination. Due to the heterogeneity of reported recovery practices and experiences, it cannot be concluded if the use of other barriers and/or hygienic precautions to avoid contamination have had an effect on bioburden detected after tissue recovery. Qualified studies are lacking which indicates a need exists for evidence-based data to support methods that reduce or control bioburden.

Vaginal progesterone in women with twin gestations complicated by short cervix: a retrospective cohort study.

OBJECTIVE: To determine whether the use of vaginal progesterone in twin gestations with a cervical length (CL) of ≤2.5 cm is associated with a reduced risk of preterm delivery. DESIGN: Retrospective cohort study. SETTING: Tertiary-care medical centre in New York City. POPULATION: Women with twin gestations undergoing sonographic cervical length screening. METHODS: Women with twin gestations with a CL of ≤2.5 cm between 16 and 32 weeks of gestation, and who delivered at our centre between 2010 and 2013, were included. We evaluated the impact of vaginal progesterone on the risk of preterm delivery using a Cox proportional hazard model, adjusted for potential confounding factors. We then performed a propensity score analysis using inverse probability of treatment weights to account for treatment selection bias and confounding. MAIN OUTCOME MEASURE: Delivery prior to 35 weeks of gestation. RESULTS: Of the 167 twin pregnancies analysed, 61 (35.7%) were treated with vaginal progesterone. The hazard ratio (HR) of delivery prior to 35 weeks of gestation in the vaginal progesterone group, compared with the no vaginal progesterone group, was 1.8 (95% confidence interval, 95% CI 1.5-3.1) in the unadjusted analysis, 1.4 (95% CI 0.7-3.2) following multivariable adjustment for confounding factors, and 1.5 (95% CI 1.1-2.3) using propensity score methods. CONCLUSION: Women with more risk factors for preterm delivery were more likely to be treated with vaginal progesterone. After statistically correcting for this with propensity score methods, we found that vaginal progesterone therapy in twin pregnancies with a CL ≤2.5 cm was associated with an increased risk of preterm delivery.

Effect of cervical cerclage on rate of cervical shortening.

OBJECTIVE: Although cerclage has been shown to reduce the risk of recurrent preterm birth in a high-risk patient population, the mechanism by which this occurs is not well understood. Our objective was to evaluate whether cerclage affects the rate of cervical shortening taking into account exposure to 17-hydroxyprogesterone and vaginal progesterone. METHODS: This was a retrospective cohort study of women who had serial cervical length measurements due to a history of spontaneous preterm delivery. Demographic data, obstetric history, progesterone administration, delivery information and serial cervical length measurements were collected. The rate of cervical shortening was compared in women with and without cerclage. Subgroup analyses were performed to compare rates of cervical shortening by indication for cerclage (history indicated vs ultrasound indicated) and outcome in the current pregnancy (cerclage vs no cerclage among those who delivered preterm). RESULTS: A total of 414 women were included of whom 32.4% (n = 134) had a cerclage. There was no difference in the rate of cervical shortening between the cerclage (0.8 mm/week) and no-cerclage (1.0 mm/week, P = 0.43) groups. The rates of cervical shortening among history-indicated and ultrasound-indicated cerclage groups were similar (0.9 vs 1.3 mm/week, respectively, P = 0.2). Among patients with a preterm delivery in the index pregnancy, the rates of cervical shortening among those with (1.31 mm/week) and without (1.28 mm/week, P = 0.78) cerclage were also similar. CONCLUSION: Cervical shortening among women with cerclage occurs at a similar rate to that among women without a cerclage, regardless of indication for cerclage or pregnancy outcome.

Pregnancy and HIV transmission among HIV-discordant couples in a clinical trial in Kisumu, Kenya.

OBJECTIVES: A large proportion of new HIV infections in sub-Saharan Africa occur in stable HIV-discordant partnerships. In some couples, the strong desire to conceive a child may lead to risky behaviour despite knowledge of discordant serostatus. Our objective was to compare HIV transmission between discordant couples who did and did not conceive during participation in a clinical trial. METHODS: Five hundred and thirty-two HIV-discordant couples were followed for up to 2 years in Kisumu, Kenya as part of the Partners in Prevention HSV/HIV Transmission Study. Quarterly HIV-1 antibody and urine pregnancy test results were analysed. RESULTS: Forty-one HIV-1 seroconversions occurred over 888 person-years of follow-up, resulting in an annual incidence of 4.6/100 person-years. Twenty seroconversions occurred among 186 HIV-1-uninfected individuals in partnerships in which pregnancy occurred (10.8% of HIV-1-negative partners in this group seroconverted), in comparison to 21 seroconversions among 353 uninfected individuals in partnerships in which pregnancy did not occur (5.9% of HIV-1-negative partners seroconverted), resulting in a relative risk of 1.8 [95% confidence interval (CI) 1.01-3.26; P<0.05]. CONCLUSIONS: Pregnancy was associated with an increased risk of HIV seroconversion in discordant couples. These data suggest that the intention to conceive among HIV discordant couples may be contributing to the epidemic.

Nucleic acid testing (NAT) of organ donors: is the 'best' test the right test? A consensus conference report.

Nucleic acid testing (NAT) for HIV, HBV and HCV shortens the time between infection and detection by available testing. A group of experts was selected to develop recommendations for the use of NAT in the HIV/HBV/HCV screening of potential organ donors. The rapid turnaround times needed for donor testing and the risk of death while awaiting transplantation make organ donor screening different from screening blood-or tissue donors. In donors with no identified risk factors, there is insufficient evidence to recommend routine NAT, as the benefits of NAT may not outweigh the disadvantages of NAT especially when false-positive results can lead to loss of donor organs. For donors with identified behavioral risk factors, NAT should be considered to reduce the risk of transmission and increase organ utilization. Informed consent balancing the risks of donor-derived infection against the risk of remaining on the waiting list should be obtained at the time of candidate listing and again at the time of organ offer. In conclusion, there is insufficient evidence to recommend universal prospective screening of organ donors for HIV, HCV and HBV using current NAT platforms. Further study of viral screening modalities may reduce disease transmission risk without excessive donor loss.

Fast asymmetric learning for cascade face detection.

A cascade face detector uses a sequence of node classifiers to distinguish faces from non-faces. This paper presents a new approach to design node classifiers in the cascade detector. Previous methods used machine learning algorithms that simultaneously select features and form ensemble classifiers. We argue that if these two parts are decoupled, we have the freedom to design a classifier that explicitly addresses the difficulties caused by the asymmetric learning goal. There are three contributions in this paper. The first is a categorization of asymmetries in the learning goal, and why they make face detection hard. The second is the Forward Feature Selection (FFS) algorithm and a fast pre- omputing strategy for AdaBoost. FFS and the fast AdaBoost can reduce the training time by approximately 100 and 50 times, in comparison to a naive implementation of the AdaBoost feature selection method. The last contribution is Linear Asymmetric Classifier (LAC), a classifier that explicitly handles the asymmetric learning goal as a well-defined constrained optimization problem. We demonstrated experimentally that LAC results in improved ensemble classifier performance.

Octafluorocyclobutane in vitreous and aqueous humor replacement.

Vitreous replacement with air, pure octafluorocyclobutane (C4F8), and mixtures of 40% C4F8 and 60% air was done in owl monkeys to determine ocular toxicity and duration of gas within the vitreous compartment. Large volumes of gas mixture and pure C4F8 caused posterior subcapsular cataract formation. Pure C4F8 expands in the vitreous within 24 to 48 hours. A 1.0-ml mixture of 40% C4F8 and 60% air lasted 12.7 days and did not cause ocular changes. However, anterior chamber aqueous replacement with pure C4F8 or gas mixture resulted in cataract production. Twenty-four and fourty-eight hours after injection of 0.1-ml pure C4F8 in the vitreous of experimental rabbits, presence of oxygen, nitrogen, and carbon dioxide was shown by gas chromatographic analysis. This finding supports the hypothesis of volume expansion secondary to diffusion of above-mentioned gases inside the C4F8 gas bubble.

Laparoscopic fundoplication for symptomatic but physiologic gastroesophageal reflux.

Esophageal pH monitoring identifies some patients who have physiologic amounts of esophageal acid exposure but have a strong correlation between symptoms of esophageal reflux events. These patients with symptomatic physiologic reflux probably have enhanced sensory perception of reflux events and may be difficult to control with acid-suppressive therapy. Little is known about the role of fundoplication in such patients. Patients with no endoscopic evidence of gastroesophageal reflux disease and a normal 24-hour pH composite score (<22.4 in our laboratory), but a symptom index (SI = number of symptoms with pH <4/total number of symptoms) greater than 50% were offered laparoscopic fundoplication if acid-suppressive therapy was unsatisfactory. This group comprised 18 (4%) of 459 patients undergoing fundoplication at our institution. Heartburn, dysphagia, and reflux symptoms were scored on a scale of 0 to 10 with patients on and off medicine preoperatively, and at a mean of 7.2 months (range 1 to 32 months) postoperatively. The 18 patients with symptomatic physiologic reflux (6 males and 12 females) had heartburn as a major complaint. Preoperative response to proton pump inhibitors for heartburn was 72% and for all symptoms was 60%. The group had a mean pH composite score of 14 (range 4 to 22). The symptom used to calculate the symptom index was heartburn in 12 patients, regurgitation in three, chest pain in two, and cough in one. An average of 18 symptoms (range 2 to 56) were recorded. The mean symptom index was 82% (range 50% to 100%). A Nissen fundoplication was performed in nine patients and a Toupet fundoplication in nine. Surgery was successful (>90%) in alleviating reflux symptoms in 14 patients and partially successful (>75%) in three of the remaining four patients. Gas bloat and dysphagia were seen in one patient each. Fundoplication is effective at relieving reflux symptoms in carefully selected patients with symptomatic physiologic reflux, with minimal side effects.

Autologous osteoblast transplantation, an innovative method of bone defect treatment: role of a tissue and cell bank in the process.

BACKGROUND: The idea of cell treatment of various diseases and medical conditions has become very popular. Some procedures are well established, as is autologous chondrocyte implantation, whereas others are still in the process of early development, laboratory experiments, and some clinical trials. METHODS: This report is devoted to an example of an emerging cell treatment: bone augmentation with the use of autologous cells and its legal and technical background. Various requirements set by law must be met by tissue banks performing cell seeding of grafts. In Europe, the requirements are described in directives 2004/23/EC, 2006/17/EC, 2006/86/EC, and in the regulation 2007/1394/EC. RESULTS: Revitalization of biostatic allografts gives new, promising tools for creation of functional parts of organs; brings the methodology used in tissue banks closer to tissue engineering; places the enterprise in the mainstream of advanced biotechnology; allows the full potential of tissue allografts; and opens a new, large area for clinical and laboratory research. Cell and tissue processing also have a financial impact on the treatment: it produces additional expenditures. CONCLUSIONS: Clinical effectiveness will be the most decisive factor of whether this innovative treatment will be applied in a particular type of medical condition. From a tissue establishment perspective, the most important issue is to develop a procedure that ensures safety for the patient in graft quality terms.

Promoting from within: the best way to build management.

One of the best ways to build knowledgeable, quality management is to promote from within the ranks of your organization. Allowing employees to work their way up the pyramid of promotion will give them the necessary knowledge to run your Call Center effectively and successfully.

The incidence of rebleeding in traumatic hyphema.

A collaborative, retrospective study of 371 consecutive hyphema patients reveals an overall 3.5% incidence of rebleeding of without the use of antifibrinolytic agents. Numerous factors were reviewed on each patient, including age, sex, race, grade of hyphema, disposition, and the use of topical or systemic medications. Thirty percent of the patients were treated on an outpatient basis. The low incidence of rebleeding, particularly in less severe hyphemas (less than half the anterior chamber volume), does not support the routine use of systemic antifibrinolytics or corticosteroids.

Beta-chemokine receptor CCR5 signals through SHP1, SHP2, and Syk.

The beta-chemokine receptor CCR5 has been shown to modulate cell migration, proliferation, and immune functions and to serve as a co-receptor for the human immunodeficiency virus. We and others have shown that CCR5 activates related adhesion focal tyrosine kinase (RAFTK)/Pyk2/CAK-beta. In this study, we further characterize the signaling molecules activated by CCR5 upon binding to its cognate ligand, macrophage inflammatory protein-1beta (MIP1beta). We observed enhanced tyrosine phosphorylation of the phosphatases SHP1 and SHP2 upon MIP1beta stimulation of CCR5 L1.2 transfectants and T-cells derived from peripheral blood mononuclear cells. Furthermore, we observed that SHP1 associated with RAFTK. However, using a dominant-negative phosphatase-binding mutant of RAFTK (RAFTK(m906)), we found that RAFTK does not mediate SHP1 or SHP2 phosphorylation. SHP1 and SHP2 also associated with the adaptor protein Grb2 and the Src-related kinase Syk. Pretreatment of CCR5 L1.2 transfectants or T-cells with the phosphatase inhibitor orthovanadate markedly abolished MIP1beta-induced chemotaxis. Syk was also activated upon MIP1beta stimulation of CCR5 L1.2 transfectants or T-cells and associated with RAFTK. Overexpression of a dominant-negative Src-binding mutant of RAFTK (RAFTK(m402)) significantly attenuated Syk activation, whereas overexpression of wild-type RAFTK enhanced Syk activity, indicating that RAFTK acts upstream of CCR5-mediated Syk activation. Taken together, these results suggest that MIP1beta stimulation mediated by CCR5 induces the formation of a signaling complex consisting of RAFTK, Syk, SHP1, and Grb2.

7. Pseudometastatic lesions of the choroid.

A 64-year-old man with a six-month history of visual loss was found to have multiple darkly pigmented lesions scattered throughout the choroid of both eyes. Some lesions, up to several disc diameters in size, were flat, but others were elevated one to two millimeters. The right eye also contained a darkly pigmented ciliary body mass. Impairment of light transmission was striking. Ultrasonography of the elevated lesions demonstrated solid masses with high internal reflectivity. The initial diagnostic differential included the possibility of pigmented metastases from a primary tumor elsewhere, as well as multiple primary nevi. A general medical examination demonstrated arteriosclerotic heart disease, hypertension, diabetes mellitus, areas of patchy pigmentation of the oral mucosa, and a hilar prominence. A mediastinal lymph node biopsy specimen showed a grade 3 undifferentiated carcinoma compatible with a lung primary carcinoma. Enlargement of the choroidal lesions was observed until the patient's death 15 months later. Autopsy showed an undifferentiated carcinoma of the lung with widespread metastases. Each eye showed multiple discrete benign melanocytomas within a diffuse nevus involving the entire uveal tract. The nature of the relationship between multiple uveal melanocytomas and the systemic carcinoma is uncertain, but recognition of multiple uveal melanocytomas warrants a general medical examination to exclude primary malignancy elsewhere.

The alpha-chemokine, stromal cell-derived factor-1alpha, binds to the transmembrane G-protein-coupled CXCR-4 receptor and activates multiple signal transduction pathways.

The alpha-chemokine stromal cell-derived factor (SDF)-1alpha binds to the seven transmembrane G-protein-coupled CXCR-4 receptor and acts to modulate cell migration and proliferation. The signaling pathways that mediate the effects of SDF-1alpha are not well characterized. We studied events following SDF-1alpha binding to CXCR-4 in a model murine pre-B cell line transfected with human CXCR-4. There was enhanced tyrosine phosphorylation and association of components of focal adhesion complexes such as the related adhesion focal tyrosine kinase, paxillin, and Crk. We also observed activation of phosphatidylinositol 3-kinase. Wortmannin, a selective inhibitor of phosphatidylinositol 3-kinase, partially inhibited the SDF-1alpha-induced migration and tyrosine phosphorylation of paxillin. SDF-1alpha treatment selectively activated p44/42 mitogen-activated protein kinase (Erk 1 and Erk 2) and its upstream kinase mitogen-activated protein kinase kinase but not p38 mitogen-activated protein kinase, c-Jun amino-terminal kinase or mitogen activated protein kinase kinase. We also observed that SDF-1alpha treatment increased NF-kappaB activity in nuclear extracts from the CXCR-4 transfectants. Taken together, these studies revealed that SDF-1alpha activates distinct signaling pathways that may mediate cell growth, migration, and transcriptional activation.