Wideband saturable absorption in few-layer molybdenum diselenide (MoSe2) for Q-switching Yb-, Er- and Tm-doped fiber lasers.

We fabricate a free-standing molybdenum diselenide (MoSe2) saturable absorber by embedding liquid-phase exfoliated few-layer MoSe2 flakes into a polymer film. The MoSe2-polymer composite is used to Q-switch fiber lasers based on ytterbium (Yb), erbium (Er) and thulium (Tm) gain fiber, producing trains of microsecond-duration pulses with kilohertz repetition rates at 1060 nm, 1566 nm and 1924 nm, respectively. Such operating wavelengths correspond to sub-bandgap saturable absorption in MoSe2, which is explained in the context of edge-states, building upon studies of other semiconducting transition metal dichalcogenide (TMD)-based saturable absorbers. Our work adds few-layer MoSe2 to the growing catalog of TMDs with remarkable optical properties, which offer new opportunities for photonic devices.

Analytic laboratory performance of a point of care urine culture kit for diagnosis and antibiotic susceptibility testing.

Currently available point-of-care (POC) diagnostic tests for managing urinary tract infections (UTIs) in general practice are limited by poor performance characteristics, and laboratory culture generally provides results only after a few days. This laboratory evaluation compared the analytic performance of the POC UK Flexicult(™) (Statens Serum Institut) (SSI) urinary kit for quantification, identification and antibiotic susceptibility testing and routine UK National Health Service (NHS) urine processing to an advanced urine culture method. Two hundred urine samples routinely submitted to the Public Health Wales Microbiology Laboratory were divided and: (1) analysed by routine NHS microbiological tests as per local laboratory standard operating procedures, (2) inoculated onto the UK Flexicult(™) SSI urinary kit and (3) spiral plated onto Colorex Orientation UTI medium (E&O Laboratories Ltd). The results were evaluated between the NHS and Flexicult(™ )methods, and discordant results were compared to the spiral plating method. The UK Flexicult(™) SSI urinary kit was compared to routine NHS culture for identification of a pure or predominant uropathogen at ≥ 10(5) cfu/mL, with a positive discordancy rate of 13.5% and a negative discordancy rate of 3%. The sensitivity and specificity were 86.7% [95% confidence interval (CI) 73.8-93.7] and 82.6% (95% CI 75.8-87.7), respectively. The UK Flexicult(™) SSI urinary kit was comparable to routine NHS urine processing in identifying microbiologically positive UTIs in this laboratory evaluation. However, the number of false-positive samples could lead to over-prescribing of antibiotics in clinical practice. The Flexicult(™) SSI kit could be useful as a POC test for UTIs in primary care but further pragmatic evaluations are necessary.

Application of a decision analytic framework for adoption of clinical trial results: are the data regarding TARGIT-A IORT ready for prime time?

The results from randomized clinical trials are often adopted slowly. This practice potentially prevents many people from benefiting from more effective care. Provide a framework for analyzing clinical trial results to determine whether and when early adoption of novel interventions is appropriate. The framework includes the evaluation of three components: confidence in trial results, impact of early, and late adoption if trial results are reversed or sustained. The adverse impact of early adoption, and the opportunity cost of late adoption are determined using Markov modeling to simulate the impact of early and late adoption in terms of quality of life years and resources gained or lost. We applied the framework to the TARGIT-A randomized clinical trial comparing intraoperative radiation (IORT) to standard external beam radiation (EBRT) and considered these results in the context of trials comparing endocrine therapy with and without radiation therapy in postmenopausal women. Confidence in the TARGIT-A trial 4 year results is high because the peak hazard for local recurrence in the trial is between 2 and 3 years. This is consistent with most trials, and no second peak has been observed in similar patient populations, suggesting that the TARGIT-A trial results are stable. The interventions offer approximately equivalent life expectancy. If IORT local recurrences rate were as high as 10 % at 10 years (which is higher than expected), we would project only 0.002 fewer expected life years (less than 1 day) compared to EBRT if IORT is adopted early. However, there is a $1.7 billion opportunity cost of waiting an additional 5 years to adopt IORT in low risk, hormone-receptor-positive, postmenopausal women. EBRT costs an additional $1467 in indirect costs per patient. Applying an evaluative framework for the adoption of clinical trial results to the TARGIT-A IORT therapy trial results in the assessment that the trial results are stable, early adoption would lead to minimal adverse impact, and substantially less resource use. Both IORT and no radiation are reasonable strategies to adopt.

Tunable Q-switched fiber laser based on saturable edge-state absorption in few-layer molybdenum disulfide (MoS2).

We fabricate a few-layer molybdenum disulfide (MoS2) polymer composite saturable absorber by liquid-phase exfoliation, and use this to passively Q-switch an ytterbium-doped fiber laser, tunable from 1030 to 1070 nm. Self-starting Q-switching generates 2.88 µs pulses at 74 kHz repetition rate, with over 100 nJ pulse energy. We propose a mechanism, based on edge states within the bandgap, responsible for the wideband nonlinear optical absorption exhibited by our few-layer MoS2 sample, despite operating at photon energies lower than the material bandgap.

Cycloserine as an alternative urinary tract infection therapy: susceptibilities of 500 urinary pathogens to standard and alternative therapy antimicrobials.

PURPOSE: Cycloserine has been used previously in some areas of the world for the treatment of urinary tract infections. The emergence of multi-resistant strains of Enterobacteriaceae and the lack of new agents in the development pipeline has prompted a need to review the activity of older agents. Susceptibility testing of cycloserine has traditionally been problematic owing to testing in standard media, containing competitive alanine, thus presenting falsely elevated minimum inhibitory concentrations (MICs). This study tests urinary coliforms against cycloserine in both standard and minimal media. METHODS: Susceptibilities were performed on 500 "wild type" UTI coliforms using Mueller-Hinton broth in the range 0.008-128 µg/ml in accordance with ISO guidelines. Cycloserine was also tested in Minimal Salts medium + 2 % 1 M glucose + 0.2 % 1 M magnesium sulphate. MICs were recorded after 18 h of incubation at 35 °C and interpreted with EUCAST breakpoints (where available). RESULTS: Cycloserine MIC50 for the "wild type" coliforms was 32 µg/ml in Mueller-Hinton broth compared with 2 µg/ml in Minimal Salts. Eighty-seven per cent of "wild type" UTI coliforms show cycloserine MICs < = 8 µg/ml in Minimal Salts. The epidemiological cut-off values for cycloserine for E. coli in this study were 64 µg/ml using Mueller-Hinton broth and 8 µg/ml using Minimal Salts medium. Ninety-four per cent of trimethoprim-resistant and 82 % of third generation cephalosporin-resistant E. coli had MICs in Minimal Salts ≤ 8 µg/ml. CONCLUSION: Cycloserine is still licensed in some countries for the treatment of urinary infections and the data presented here suggest that it may play a role in the management of infections resistant to trimethoprim and third generation cephalosporins.

Depletion of cells and abundant proteins from biological samples by enhanced dielectrophoresis.

Platforms that are sensitive and specific enough to assay low-abundance protein biomarkers, in a high throughput multiplex format, within a complex biological fluid specimen, are necessary to enable protein biomarker based diagnostics for diseases such as cancer. The signal from an assay for a low-abundance protein biomarker in a biological fluid sample like blood is typically buried in a background that arises from the presence of blood cells and from high-abundance proteins that make up 90% of the assayed protein mass. We present an automated on-chip platform for the depletion of cells and highly abundant serum proteins in blood. Our platform consists of two components, the first of which is a microfluidic mixer that mixes beads containing antibodies against the highly abundant proteins in the whole blood. This complex mixture (consisting of beads, cells, and serum proteins) is then injected into the second component of our microfluidic platform, which comprises a filter trench to capture all the cells and the beads. The size-based trapping of the cells and beads into the filter trench is significantly enhanced by leveraging additional negative dielectrophoretic forces to push the micron sized particles (cells and beads which have captured the highly abundant proteins) down into the trench, allowing the serum proteins of lower abundance to flow through. In general, dielectrophoresis using bare electrodes is incapable of producing forces beyond the low piconewton range that tend to be insufficient for separation applications. However, by using electrodes passivated with atomic layer deposition, we demonstrate the application of enhanced negative DEP electrodes together with size-based flltration induced by the filter trench, to deplete 100% of the micron sized particles in the mixture.

BSAC standardized disc susceptibility testing method (version 11).

This article highlights key amendments incorporated into version 11 of the BSAC standardized disc susceptibility testing method, available as Supplementary data at JAC Online (http://jac.oxfordjournals.org/) and on the BSAC web site (http://bsac.org.uk/susceptibility/guidelines-standardized-disc-susceptibility-testing-method/). The basic disc susceptibility testing method remains unchanged, but there have been a number of alterations to the interpretive criteria for certain organism/drug combinations due to continuing harmonization with the EUCAST MIC breakpoints and constant efforts to improve the reliability and clinical applicability of the guidance.

BSAC standardized disc susceptibility testing method (version 10).

The BSAC standardized disc susceptibility testing method remains unchanged, but there are considerable changes to the interpretative criteria due to continuing harmonization with the European Committee on Antimicrobial Susceptibility Testing (EUCAST) MIC breakpoints. There are a number of agents for which interpretative criteria have been removed. These MIC and/or zone diameter breakpoints will be published on the BSAC web site as a 'Legacy' table; they may be used for research or comparative purposes, but are not recommended for clinical management. Notably, testing of staphylococci for susceptibility to glycopeptides by disc diffusion has been removed because this method has been found to be unreliable, particularly for the detection of low-level resistance; low-level vancomycin resistance in staphylococci is increasingly deemed to be of clinical relevance. The tables for anaerobes have been expanded to include MIC breakpoints that have been determined by EUCAST. There are currently no zone diameter breakpoints for these organisms and an MIC method is recommended if susceptibility testing is required.

WITHDRAWN: Terazosin for benign prostatic hyperplasia.

BACKGROUND: Lower urinary tract symptoms associated with benign prostatic obstruction (BPO) occur in up to 70% of men over the age of 60 years. To relieve these bothersome symptoms, treatment options include alpha-antagonists, also know as alpha-blockers. OBJECTIVES: We conducted a systematic review to evaluate the effectiveness and adverse effects of the alpha-blocker, terazosin, for treatment of urinary symptoms associated with BPO. SEARCH STRATEGY: Trials were searched in computerized general and specialized databases (MEDLINE, Cochrane Library), by checking bibliographies, and by contacting manufacturers and researchers. SELECTION CRITERIA: Studies were included if they (1) were randomized trials of at least 1 month duration, and (2) included men with symptomatic BPO and compared terazosin with placebo or active controls. DATA COLLECTION AND ANALYSIS: Study, patient characteristics and outcomes data were extracted in duplicate onto standardized forms utilizing a prospectively developed protocol. The main outcome measure for comparing the effectiveness of terazosin with placebo or other BPO medications was change in urological symptoms as measured by validated symptom scores. Secondary outcomes included urodynamic measures. The main outcome measure for adverse effects was the number of men reporting side effects. We also evaluated the number of men withdrawing from treatment and the number withdrawing due to adverse effects. MAIN RESULTS: Seventeen studies involving 5151 subjects met inclusion criteria (placebo-controlled (n = 10); alpha-blockers (n = 7); finasteride alone or in combination with terazosin as well as placebo (1); microwave therapy (TUMT) (1). Study duration ranged from 4 to 52 weeks. Mean age was 65 years and 82% of men were white. Baseline urologic symptom scale scores and flow rates demonstrated that men had moderate BPO. Efficacy outcomes were rarely reported in a fashion that allowed for data pooling but indicated that terazosin improved symptom scores and flow rates more than placebo or finasteride and similarly to other alpha antagonists. The pooled mean percentage improvements for the Boyarsky symptom score was 37% for terazosin versus 15% for placebo (n = 4 studies). The mean percentage improvement for the American Urological Association symptom score (AUA) was 38% compared to 17% and 20% for placebo and finasteride, respectively (n = 2 studies). The pooled mean improvement in the International Prostate Symptom Score (IPSS) (40%) was similar to tamsulosin (43%). Peak urine flow rates improved greater with terazosin (22%), than placebo (11%) and finasteride (15%) but did not differ significantly from the other alpha-blockers. The percentage of men discontinuing terazosin was comparable to men receiving placebo and finasteride but was greater then with other alpha-antagonists. Adverse effects were greater than placebo and included dizziness, asthenia, headache, and postural hypotension. AUTHORS' CONCLUSIONS: The available evidence suggests that terazosin improves urinary symptoms and flow measures associated with BPO. Effectiveness is superior to placebo or finasteride, similar to other alpha-blockers but less than TUMT. Adverse effects were generally mild but more frequent than other alpha-blockers and associated with between a two-to-four fold increase in treatment discontinuation.

Individualization of exosuit assistance based on measured muscle dynamics during versatile walking.

Variability in human walking depends on individual physiology, environment, and walking task. Consequently, in the field of wearable robotics, there is a clear need for customizing assistance to the user and task. Here, we developed a muscle-based assistance (MBA) strategy wherein exosuit assistance was derived from direct measurements of individuals' muscle dynamics during specific tasks. We recorded individuals' soleus muscle dynamics using ultrasonographic imaging during multiple walking speeds and inclines. From these prerecorded images, we estimated the force produced by the soleus through inefficient concentric contraction and designed the exosuit assistance profile to be proportional to that estimated force. We evaluated this approach with a bilateral ankle exosuit at each measured walking task. Compared with not wearing a device, the MBA ankle exosuit significantly reduced metabolic demand by an average of 15.9, 9.7, and 8.9% for level walking at 1.25, 1.5, and 1.75 meters second−1, respectively, and 7.8% at 1.25 meters second−1 at 5.71° incline while applying lower assistance levels than in existing literature. In an additional study (n = 2), we showed for multiple walking tasks that the MBA profile outperforms other bioinspired strategies and the average profile from a previous optimization study. Last, we show the feasibility of online assistance generation in a mobile version for overground outdoor walking. This muscle-based approach enables relatively rapid (~10 seconds) generation of individualized low-force assistance profiles that provide metabolic benefit. This approach may help support the adoption of wearable robotics in real-world, dynamic locomotor tasks by enabling comfortable, tailored, and adaptive assistance.

Developmentally regulated expression of T cell receptor beta chain variable domains in immature thymocytes.

A minor subset of immature (CD4-,8-) thymocytes that lack expression of the B2A2 antigen was found to express low levels of surface TCR protein as detected by mAbs F23.1 and KJ16 (reacting with protein products of the V beta 8 gene family). Interestingly, F23.1/KJ16 determinants were expressed on a two- to three-fold higher proportion of B2A2- thymocytes than mature lymph node T cells in four independent haplotypes. When expanded in short-term culture with PMA and calcium ionophore, B2A2- thymocytes retained their overexpression of F23.1/KJ16 determinants and showed a fivefold elevated level (relative to lymph node) of V beta 8-specific mRNA. Taken together, these findings suggest that expression of TCR V beta genes, like Ig genes, is developmentally regulated.

Occult Hepatitis B virus infection among HIV negative and positive isolated anti-HBc individuals in eastern Ethiopia.

The absence of hepatitis B surface antigen (HBsAg) and the presence of antibody to hepatitis B core antigen (anti-HBc) in the blood of apparently healthy individuals may not indicate the absence of circulating hepatitis B virus (HBV) and might be infectious. Despite the risk of HBV transmission, there has been no report from Ethiopia examining this issue; therefore, this study determined occult HBV infection (OBI) among isolated anti-HBc (IAHBc) HIV negative and HIV positive individuals on ART in eastern Ethiopia. A total of 306 IAHBc individuals were included in this study. DNA was extracted, amplified, and detected from plasma using a commercially available RealTime PCR platform (Abbott m2000rt) following the manufacturer's instructions. Data were entered into EPI Data version 3.1, cleaned, and analyzed using Stata version 13. Descriptive analysis was used to calculate prevalence, summarize sociodemographic data and other factors. From the 306 IAHBc individuals (184 HIV positive and 122 HIV negative) included in the study, 183 (59.8%) were female of which 142 (77.6%) were within the reproductive age group. DNA extraction, amplified and detection was conducted in 224 individuals. The overall OBI prevalence was 5.8% (5.6% in HIV negative and 6% in HIV positive) among the IAHBc individuals. The HBV DNA concentration among the occult hepatitis B individuals was < 200 IU/mL, indicating a true occult. This study reported the burden of OBI, which pauses a significant public health problem due to the high burden of HBV infection in the country. OBI may cause substantial risk of HBV transmission from blood transfusion, organ transplantation as well as vertical transmission as screening is solely dependent on HBsAg testing.

Impact of rapid microbial identification on clinical outcomes in bloodstream infection: the RAPIDO randomized trial.

OBJECTIVES: Bloodstream infection has a high mortality rate. It is not clear whether laboratory-based rapid identification of the organisms involved would improve outcome. METHODS: The RAPIDO trial was an open parallel-group multicentre randomized controlled trial. We tested all positive blood cultures from hospitalized adults by conventional methods of microbial identification and those from patients randomized (1:1) to rapid diagnosis in addition to matrix-assisted desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) performed directly on positive blood cultures. The only primary outcome was 28-day mortality. Clinical advice on patient management was provided to members of both groups by infection specialists. RESULTS: First positive blood culture samples from 8628 patients were randomized, 4312 into rapid diagnosis and 4136 into conventional diagnosis. After prespecified postrandomization exclusions, 2740 in the rapid diagnosis arm and 2810 in the conventional arm were included in the mortality analysis. There was no significant difference in 28-day survival (81.5% 2233/2740 rapid vs. 82.3% 2313/2810 conventional; hazard ratio 1.05, 95% confidence interval 0.93-1.19, p 0.42). Microbial identification was quicker in the rapid diagnosis group (median (interquartile range) 38.5 (26.7-50.3) hours after blood sampling vs. 50.3 (47.1-72.9) hours after blood sampling, p < 0.01), but times to effective antimicrobial therapy were no shorter (respectively median (interquartile range) 24 (2-78) hours vs. 13 (2-69) hours). There were no significant differences in 7-day mortality or total antibiotic consumption; times to resolution of fever, discharge from hospital or de-escalation of broad-spectrum therapy or 28-day Clostridioides difficile incidence. CONCLUSIONS: Rapid identification of bloodstream pathogens by MALDI-TOF MS in this trial did not reduce patient mortality despite delivering laboratory data to clinicians sooner.

Emergence of high-level azithromycin resistance in Neisseria gonorrhoeae in England and Wales.

OBJECTIVES: This study aimed to investigate the origin of high-level azithromycin resistance that emerged in isolates of Neisseria gonorrhoeae in England and Wales in 2007, and to establish methods for identifying high-level azithromycin resistance. METHODS: The Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) data from 2001-07 were examined for emerging trends in azithromycin susceptibility. Further to the identification of six high-level azithromycin-resistant isolates in GRASP 2007, an additional 102 isolates were selected on the basis of azithromycin susceptibility and geographic origin from the GRASP 2006 and 2007 collections. Susceptibility testing by Etest and disc diffusion was performed on all 108 isolates and 75 of these were typed by N. gonorrhoeae multiantigen sequence typing. RESULTS: A slight drift towards higher MICs of azithromycin was observed in the gonococcal population since 2001. Of greater concern was the first example of a shift to high-level resistance observed in six isolates in 2007. All six isolates were sequence type 649, which was not observed in any of the lower-level azithromycin-resistant isolates from 2007 or in any isolates tested from the same geographical locations. Contact tracing data for one patient suggested a link with Scotland. Disc diffusion testing of all 108 isolates showed that azithromycin, but not erythromycin, discs can differentiate between low-level and high-level resistance. CONCLUSIONS: High-level azithromycin resistance has emerged in England and Wales. Contact tracing and typing data suggest this may have originated from Scotland. Surveillance of azithromycin resistance will be key in controlling its further dissemination.

Facilitation of spindle-burst sleep by conditioning of electroencephalographic activity while awake.

A slow-wave electroencephalographic rhythm recorded from the sensorimotor cortex of the waking cat has been correlated behaviorally with the suppression of movement. Facilitation of this rhythm through conditioning selectively enhances a similar pattern recorded during sleep, the familiar spindle burst. The training also produced longer epochs of undisturbed sleep. The specific neural mechanism manipulated during wakefulness appears to function also in sleep and to be involved with the regulation of phasic motor behavior.

Visualization of turbulent flame fronts with planar laser-induced fluorescence.

This report concerns the quantitative time-resolved visualization of reaction zones in laminar, transitional, and turbulent nonpremixed flames. Two-dimensional OH molecular concentrations were measured with planar laser-induced fluorescence excited by a sheet of light (formed from a single tunable ultraviolet laser pulse) and detected with a two-dimensional, image-intensified photodiode array camera. From the resulting data details of instantaneous flame front structures (including positions, shapes, and widths) were obtained.

Repeated evolution of drag reduction at the air-water interface in diving kingfishers.

Piscivorous birds have a unique suite of adaptations to forage under the water. One method aerial birds use to catch fish is the plunge dive, wherein birds dive from a height to overcome drag and buoyancy in the water. The kingfishers are a well-known clade that contains both terrestrially foraging and plunge-diving species, allowing us to test for morphological and performance differences between foraging guilds in an evolutionary context. Diving species have narrower bills in the dorsoventral and sagittal plane and longer bills (size-corrected data, n = 71 species, p < 0.01 for all). Although these differences are confounded by phylogeny (phylogenetically corrected ANOVA for dorsoventral p = 0.26 and length p = 0.14), beak width in the sagittal plane remains statistically different ( p < 0.001). We examined the effects of beak morphology on plunge performance by physically simulating dives with three-dimensional printed models of beaks coupled with an accelerometer, and through computational fluid dynamics (CFD). From physically simulated dives of bill models, diving species have lower peak decelerations, and thus enter the water more quickly, than terrestrial and mixed-foraging species (ANOVA p = 0.002), and this result remains unaffected by phylogeny (phylogenetically corrected ANOVA p = 0.05). CFD analyses confirm these trends in three representative species and indicate that the morphology between the beak and head is a key site for reducing drag in aquatic species.

Studies of bilirubin kinetics in normal adults.

This report describes studies of bilirubin kinetics in 13 healthy young adults. The plasma content of unconjugated bilirubin-(14)C was determined at frequent intervals for 24-30 hr after the intravenous injection of a tracer dose of unconjugated isotopic bilirubin. Fecal and urinary radioactivity were measured for 7 days. During this time cumulative recovery averaged 96% of the injected dose. The plasma curves were processed by digital computer. For the 30 hr experimental period, a sum of three exponentials, with average half-times of 18, 81, and 578 min, was required to describe the data. Using the plasma curve integral method, the hepatic bilirubin clearance (47 +/-10 ml/min, mean +/-SD), the bilirubin production rate (3.8 +/-0.6 mg/kg per day), and the mean red blood cell life span (101 +/-13 days) were calculated directly from the parameters of this function. To gain further insight into the metabolism of unconjugated bilirubin, the data were also used to determine the parameters of a multicompartmental model. In the model proposed, plasma unconjugated bilirubin exchanges with two additional pools one of which is thought to represent extrahepatic extravascular, and the other intrahepatic unconjugated bilirubin. Bilirubin is eliminated from the system via the proposed intrahepatic pool. From the data and the model, pool sizes and exchange rates between compartments were calculated, and the liver: plasma concentration gradient estimated. These studies provide a detailed analysis of the kinetics of unconjugated bilirubin in a healthy normal population and are intended to serve as a reference point for studies of abnormal states.

Quantitative studies of the delivery of hepatic-synthesized bilirubin to plasma utilizing -aminolevulinic acid-4- 14 C and bilirubin- 3 H in man.

After the simultaneous intravenous administration of unconjugated bilirubin-(3)H and delta-aminolevulinic acid-4-(14)C, the plasma disappearance curves of unconjugated bilirubin-(3)H and the plasma appearance curves of biosynthesized unconjugated bilirubin-(14)C have been defined in seven patients, three of whom had acute intermittent porphyria (AIP). The incorporation of (14)C into plasma unconjugated bilirubin, derived by an analysis which involves deconvolution of the two plasma curves, varied between 13.1 and 23.5% (mean 19.3%) of the injected dose in the nonporphyric patients and between 5.4 and 13.6% (mean 8.3%) of the injected dose in the porphyric patients. In five of the patients, the stercobilin-(14)C specific activity in a pooled specimen of feces was measured, enabling the following further values to be calculated: (a) the total (14)C radioactivity incorporated into bilirubin (21.0 and 25.3% [mean 23.2%] of the injected dose in two of the nonporphyric patients and between 8.5 and 25.3% [mean 14.2%] of the injected dose in the porphyric patients), and (b) the proportion of hepatic synthesized bilirubin delivered directly to plasma in the unconjugated form (between 0.520 and 0.904; mean for nonporphyric patients 0.712; mean for porphyric patients 0.614). The results demonstrate that a large proportion of bilirubin derived from hepatic hemes passes through the plasma in the unconjugated form before conjugation and secretion into bile.

Distribution of Lyb-4.1 and other membrane antigens on murine lymphoid tumors.

The distribution of membrane antigens on 6 DBA/2-derived tumors (L1210, L5178Y, P815, ABLS 11, ABLS 12, and ABLS 13) was studied by direct cytotoxicity and quantitative absorption assays. Lyb-4.1 antigen was found solely on the L1210 tumor. Iad antigens were absent from all tumors, and H-2Kd and H-2Dd antigens were present on all tumors. Immunoglobulin was adsorbed to the ascites tumors and lost after 3 days or more in tissue culture. These studies were performed to characterize the distribution of DBA/2 membrane antigens on DBA/2-derived tumors as a base line for functional and chemical studies with these tumors and with their solubilized proteins.