Detection of cytomegalovirus antibody in platelet concentrates by fluorescence immunoassay and latex agglutination

A passive latex agglutination (PLA) test for cytomegalovirus (CMV) antibody detection has been shown to be an acceptable method of screening both donor sera and plasma from units of red cells and platelets stored in CPDA-1. However, most plateletpheresis concentrates are collected in ACD, and CMV antibody testing of ACD-stored products has not been systematically evaluated by PLA. Sera and ACD-stored platelet concentrate bag segments from 104 donors were tested by PLA and by a solid-phase fluorescence immunoassay (FIAX) as a reference standard for CMV-IgM and CMV-IgG antibodies. Sera were stored at both 4 and 22 degrees C and were tested on Days 1 and 5 of storage; segments were tested daily for 5 days. Of 63 donor samples (61%) that tested negative for CMV-IgG by FIAX, there were two false-positive results in bag segments by PLA testing, one on Day 1 and the other on Day 2 of storage. PLA testing was consistently positive in sera and segments in the 40 donors (38%) who tested positive for CMV-IgG by FIAX. Potential false-negative PLA results occurred in five bag segments derived from one donor whose serum gave equivocal CMV-IgG results on FIAX. The sensitivity and specificity of the PLA assay were 100 percent for donor sera tested at both 4 and 22 degrees C and 91.5 and 98.4 percent, respectively, for platelet bag segment tests. Although no donors positive for CMV-IgM were identified, 15 (14.4%) had equivocal IgM anti-CMV test results.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultrasound-guided aspiration of hydrosalpinges is associated with improved pregnancy and implantation rates after in-vitro fertilization cycles

Previous reports have shown that the presence of hydrosalpinges may have a detrimental effect on in-vitro fertilization (IVF) outcomes and salpingectomy has been recommended by some authors as a means of improving IVF pregnancy rates. Our first objective was to determine the effect of hydrosalpinges diagnosed by ultrasound on IVF outcomes in our clinic. Our second objective was to examine the effects of aspiration of hydrosalpinges at the time of oocyte retrieval on IVF outcomes. Women with hydrosalpinges (n=34) were compared with women who had tubal disease but no hydrosalpinges (n=124) and were found to have a reduced clinical pregnancy rate (18 % versus 37%, P=0.053), a reduced ongoing pregnancy rate (15 versus 34%, P=0.051), and a reduced implantation rate (7 versus 18%, P=0.003) after IVF procedures. Among women with hydrosalpinges present, 16 had their hydrosalpinges aspirated at the time of oocyte retrieval and 18 did not. Aspiration of hydrosalpinges was associated with a higher clinical pregnancy rate (31 versus 5%, P=0.07), a higher ongoing pregnancy rate (31 versus 0%, P=0.015), and a higher implantation rate (14 versus 1%, P=0.015). This study confirms the association between the presence of hydrosalpinges and poor IVF outcomes. We find that aspiration of hydrosalpinges at the time of oocyte retrieval leads to improved pregnancy rates and may be an acceptable alternative to salpingectomy for treatment of these patients.      

Human Health Effects of Trichloroethylene: Key Findings and Scientific Issues

Background: In support of the Integrated Risk Information System (IRIS), the U.S. Environmental Protection Agency (EPA) completed a toxicological review of trichloroethylene (TCE) in September 2011, which was the result of an effort spanning > 20 years.Objectives: We summarized the key findings and scientific issues regarding the human health effects of TCE in the U.S. EPA’s toxicological review.Methods: In this assessment we synthesized and characterized thousands of epidemiologic, experimental animal, and mechanistic studies, and addressed several key scientific issues through modeling of TCE toxicokinetics, meta-analyses of epidemiologic studies, and analyses of mechanistic data.Discussion: Toxicokinetic modeling aided in characterizing the toxicological role of the complex metabolism and multiple metabolites of TCE. Meta-analyses of the epidemiologic data strongly supported the conclusions that TCE causes kidney cancer in humans and that TCE may also cause liver cancer and non-Hodgkin lymphoma. Mechanistic analyses support a key role for mutagenicity in TCE-induced kidney carcinogenicity. Recent evidence from studies in both humans and experimental animals point to the involvement of TCE exposure in autoimmune disease and hypersensitivity. Recent avian and in vitro mechanistic studies provided biological plausibility that TCE plays a role in developmental cardiac toxicity, the subject of substantial debate due to mixed results from epidemiologic and rodent studies.Conclusions: TCE is carcinogenic to humans by all routes of exposure and poses a potential human health hazard for noncancer toxicity to the central nervous system, kidney, liver, immune system, male reproductive system, and the developing embryo/fetus.     

Stereotactic Radiofrequency Ablation (SRFA) of Liver Lesions: Technique Effectiveness, Safety, and Interoperator Performance

Purpose

To evaluate technique effectiveness, safety, and interoperator performance of stereotactic radiofrequency ablation (SRFA) of liver lesions.

Methods

Retrospective review including 90 consecutive patients from January 2008 to January 2010 with 106 computed tomography-guided SRFA sessions using both single and multiple electrodes for the treatment of 177 lesions: 72 hepatocellular carcinoma (HCC) and 105 metastases with a mean size of 2.9?cm (range 0.5?C11?cm). Technique effectiveness and 1-year local recurrence were evaluated by computed tomographic scans. Complications, mortality, and hospital days were recorded. The performance between an experienced and inexperienced interventional radiologist was compared.

Results

The overall technique effectiveness after a single SRFA was 95.5% (93.1% for HCC and 97.1% for metastases). Four of the eight unsuccessfully treated lesions could be retreated (secondary technique effectiveness of 97.7%). Local recurrence at 1?year was 2.9%. Technique effectiveness was significantly different for lesions <5?cm (96.7%) and >5?cm (87.5%) (P?=?0.044) but not for lesions <3?cm (95.9%) and 3?C5?cm (100%). Compared to clear parenchymal property (97.3%), vessel vicinity (93.3%) (P?=?0.349) and subcapsular (95.2%) (P?=?0.532) had no, but hollow viscera vicinity (83.3%) had a significantly lower technique effectiveness (P?=?0.020). Mortality rate was 0.9%. Major complications and hospital days were higher for cirrhosis Child-Pugh B (20%, 7.2?days) than Child-Pugh A (3.1%, 4.7?days) patients and for metastases (5.1%, 4.3?days). There was no significant difference in interoperator performance.

Conclusion

SRFA allowed for efficient, reliable, and safe ablation of large-volume liver disease.     

A new broadband near-infrared spectroscopy system for in-vivo measurements of cerebral cytochrome-c-oxidase changes in neonatal brain injury

We present a novel lens-based broadband near-infrared spectroscopy system to simultaneously measure cerebral changes in tissue oxygenation and haemodynamics via estimation of the changes in haemoglobin concentration; in addition to oxygen utilization via the measurement of the oxidation state of cytochrome-c-oxidase (CCO). We demonstrate the use of the system in a cohort of 6 newborn infants with neonatal encephalopathy in the Neonatal Intensive Care Unit for continuous measurement periods of up to 5 days. NIRS data was collected from above the frontal lobe on the left and right hemispheres simultaneously with systemic data to allow multimodal data analysis. This allowed us to study the NIRS variables in response to global pathophysiological events and we focused our analysis to spontaneous oxygen desaturations. We identified changes from the NIRS variables during 236 oxygen desaturations from over 212 hours of data with a change from the baseline to nadir of −12 ± 3%. There was a consistent negative change in the Δ[HbD] (= oxygenated – deoxygenated haemoglobin) and Δ[oxCCO] measurements, mean decreases were 3.0 ± 1.7μM and 0.22 ± 0.11μM, and a positive change in the Δ[HbT] (= oxygenated + deoxygenated haemoglobin) measurements across all subjects, mean increase was 0.85 ± 0.58μM. We have shown with a feasibility study that the relationship between haemoglobin oxygenation changes and CCO oxidation changes during these desaturation events was significantly associated with a magnetic resonance spectroscopy (MRS)-measured biomarker of injury severity (r = 0.91, p<0.01).OCIS codes: (170.6510) Spectroscopy, tissue diagnostics; (170.3890) Medical optics instrumentation     

Computational protein design enables a novel one-carbon assimilation pathway

We describe a computationally designed enzyme, formolase (FLS), which catalyzes the carboligation of three one-carbon formaldehyde molecules into one three-carbon dihydroxyacetone molecule. The existence of FLS enables the design of a new carbon fixation pathway, the formolase pathway, consisting of a small number of thermodynamically favorable chemical transformations that convert formate into a three-carbon sugar in central metabolism. The formolase pathway is predicted to use carbon more efficiently and with less backward flux than any naturally occurring one-carbon assimilation pathway. When supplemented with enzymes carrying out the other steps in the pathway, FLS converts formate into dihydroxyacetone phosphate and other central metabolites in vitro. These results demonstrate how modern protein engineering and design tools can facilitate the construction of a completely new biosynthetic pathway.Novel strategies are needed to address current challenges in energy storage and carbon sequestration. One approach is to engineer biological systems to convert one-carbon compounds into multicarbon molecules such as fuels and other high value chemicals. Many synthetic pathways to produce value-added chemicals from common feedstocks, such as glucose, have been constructed in organisms that lack one-carbon anabolic pathways, such as Escherichia coli or Saccharomyces cerevisiae (1–3); however, despite considerable effort, it has been difficult to introduce heterologous one-carbon fixing pathways into these organisms (4). Likely problems include the inherent complexity, environmental sensitivity, inefficiency, or unfavorable chemical driving force of naturally occurring one-carbon metabolic pathways (5).An optimal pathway for one-carbon utilization in common synthetic biology platforms would be (i) composed of a minimal number of enzymes, (ii) linear and disconnected from other metabolic pathways, (iii) thermodynamically favorable with a significant driving force at most or all steps, and (iv) capable of functioning in a robust manner under both aerobic and anaerobic conditions (5). A pathway with these properties could enable the assimilation of one-carbon molecules as the sole carbon source for the production of fuels and chemicals. Although no such pathway is known in nature, the established electrochemical reduction of carbon dioxide to formate under ambient temperatures and pressures in neutral aqueous solutions provides an attractive starting point for a one-carbon fixation pathway (5–8).We describe the computational design of an enzyme that catalyzes the carboligation of three one-carbon molecules into a single three-carbon molecule. This enzyme enables the construction of a new pathway, the formolase pathway, in which formate is converted into the central metabolite dihydroxyacetone phosphate (DHAP; Fig. 1). The use of computational protein design to reengineer catalytic activities opens up the pathway design space beyond that available based on existing enzymes.Open in a separate windowFig. 1.Overview of formolase pathway reactions. (A) Benzaldehyde lyase couples two benzaldehydes into benzoin through an acyloin addition reaction. (B) Acetyl-CoA synthase (ACS) catalyzes the ATP-dependent conversion of acetate into acyl-CoA. (C) Acetaldehyde dehydrogenase (ACDH) catalyzes the NADH-dependent reduction of acetyl-CoA to acetaldehyde. (D) Conversion of formate to dihydroxyacetone phosphate (DHAP) by the formolase pathway. To generate reducing equivalents in the cell, formate is oxidized by formate dehydrogenase (FDH) to produce CO₂ and NADH (stage 1). To use formate as a carbon source, activation (stage 2) and carbon-carbon coupling (stage 3) to form dihydroxyacetone (DHA) are carried out by the enzymes ACS, ACDH, and formolase (FLS). DHA is phosphorylated to DHAP, a glycotic intermediate by a dihydroxyacetone kinase (DHAK) (stage 4). The novel enzyme functions identified here are underlined.     

Persistent acid reflux and symptoms in patients with Barrett's oesophagus on proton-pump inhibitor therapy

OBJECTIVES: To assess both acid gastro-oesophageal reflux (GOR) suppression in patients with Barrett's oesophagus on proton-pump inhibitors (PPI) and the predictive value of symptoms.DESIGN A prospective study of patients with Barrett's epithelium (> 3 cm, containing specialized intestinal metaplasia).PATIENTS AND METHODS: Forty-five patients with Barrett's epithelium were recruited. Therapy was adjusted to omeprazole 20 mg twice daily. Oesophageal manometry and 24 h pH studies were performed on treatment. Heartburn score was calculated before and after PPI dose adjustment. In patients with persisting acid reflux, omeprazole dose was increased to 20 mg three times daily and pH studies repeated. Adequacy of GOR suppression, assessed by pH monitoring, was related to heartburn score (0-3). RESULTS: Twenty of the 45 patients were symptomatic (mean score 1.9) on pre-study treatment (mainly omeprazole < 20 mg once daily); on omeprazole 20 mg twice daily, only six patients remained symptomatic (mean score 1.6). Ten patients (22%) had persisting GOR on omeprazole 20 mg twice daily (median % total time with pH < 4 was 8%). Abnormal nocturnal reflux was found in nine and abnormal daytime reflux in only four patients. Heartburn persisted in three of these 10 patients (30%). Those remaining symptomatic had more daytime acid reflux than the asymptomatic patients with persistent reflux (median percentage daytime at pH < 4 was 13.6% vs 0.6%, respectively; P < 0.01). By increasing the omeprazole dose to 20 mg three times daily, only three of the 10 had persistent acid reflux. CONCLUSIONS: Persistent acid reflux on PPI therapy is common in patients with Barrett's oesophagus. Although nocturnal acid reflux is the most common finding, symptoms tended to occur in those with abnormal daytime reflux. Symptom resolution does not guarantee acid reflux control.