Stabilization of a Kerr frequency comb oscillator

We study stability and spectral purity of a microresonator-based Kerr frequency comb oscillator experimentally and observe a correlation between the frequency of the continuous wave laser pumping the nonlinear resonator and the repetition frequency of the comb. This correlation is used in a proof-of-principle demonstration of a Kerr frequency comb stabilized with an optical transition of 87Rb.

Trends in pneumonia (PNA) hospitalization among patients (pts) with chronic lymphocytic leukemia (CLL)

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Background: Despite recent therapeutic advances, PNA remains a significant source of morbidity and mortality among CLL pts. We determined population-level estimates for the incidence and outcome of PNA hospitalizations. We further investigated secular trends in care by comparing cohorts before (1994) and after (2004) the widespread use of multiagent chemoimmunotherapy. Methods: Using data from the U.S. Nationwide Inpatient Sample and ICD-9CM diagnosis codes, we identified all non-governmental hospitalizations of CLL pts for a primary dx of PNA in calendar years 1994 and 2004. Admissions were described by pt demographics (age, gender, race) and comorbidity (Charlson index, presence of chronic lung disease). Ten-year prevalence estimates for CLL were obtained from NCI SEER data and used as denominators in incidence calculations. Outcomes studied included need for intubation, in-hospital mortality, and length of stay (LOS). All analyses were sample weighted. Estimates and 95% confidence limits are reported. Results: PNA was the primary dx for 7316 (13.1%) and 7651 (11.2%) CLL pt admissions in 1994 and 2004, respectively. Incidence of PNA admission was similar in 1994 (140/per 1000 pts, 95%CI 130–151) and 2004 (129/per 1000 pts, 95%CI 119–138). CLL pts admitted in 2004 were older (75.7 v. 74.2 years, p<0.001) and more likely to have at least one Charlson comorbidity (67.6% v. 56.2%, p<0.001) or comorbid chronic lung disease (40.6% v. 28.3%, p<0.001) than pts in 1994. Intubation was rare in both cohorts (<1%) and did not significantly differ by year, but in-hospital mortality was significantly higher in 2004 (11.3% v. 8.2%, p=0.005). However, LOS decreased significantly between 1994 and 2004 (9.2 v. 6.4 days, p<0.001). Conclusions: PNA hospitalization rates for CLL pts have not significantly increased over the last decade despite more aggressive therapies, likely secondary to improved supportive care. However, CLL pts hospitalized for PNA are now older, increasingly likely to suffer from chronic medical illness, and significantly more likely to die while in hospital. Therapuetic strategies targeting older pts with significant comorbidities are needed.

No significant financial relationships to disclose.

Lumiliximab (anti-CD23 antibody) mediates apoptosis and antitumor activity in chronic lymphocytic leukemia (CLL) cells and CD23+ lymphoma cell lines

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Background: Given the success of treating CLL with antibody therapies, interest in those directed at alternative B-cell antigens remains high. Lumiliximab is a chimeric macaque and human anti-CD23 monoclonal antibody whose antigen is expressed on almost all CLL cells. Methods: We examined lumiliximab’s ability to mediate direct apoptosis, antibody-dependent cellular cytotoxicity (ADCC), and complement-dependent cytotoxicity (CDC) against primary CLL cells and CD23+ B-cell lines. Apoptosis was measured with a flow-cytometry based assay for active caspase-3. ADCC was determined by 51Cr-release assay. CDC assays were performed in the presence of 30% autologous plasma from patients and quantified by propidium iodide staining. Western blotting analysis was used to monitor protein expression before and after treatment with lumiliximab. The CD23+ human lymphoma SKW6.4 cell line was used for in vivo evaluation of lumiliximab in a disseminated human lymphoma model. Results: Lumiliximab mediates apoptosis, ADCC, and CDC in CD23+ B-cell lines. However, in primary CLL cells, the primary mechanism of cell killing appears to be mediated via apoptosis. Apoptosis induced by lumiliximab occurs mainly through the intrinsic pathway used by other CLL therapies. Lumiliximab decreased expression of Bcl-2 and XIAP and inhibited Akt activation in CLL cells. Lumiliximab when combined in vitro or in vivo with rituximab or fludarabine effectively mediates synergistic cytotoxicity against primary CLL cells and CD23+ B-cell lines. Significant antitumor activity was also observed with lumiliximab vs a control antibody in a SCID mouse model of human B-cell lymphoma (P <.01). More importantly, lumiliximab + rituximab or lumiliximab + fludarabine results in prolonged survival vs lumiliximab, rituximab, or fludarabine single-agent treatment. Conclusions: These results indicate that lumiliximab induces apoptosis by activating caspases and downregulating antiapoptotic proteins, and suggest that in combination with rituximab or chemotherapy, lumiliximab synergistically enhances antitumor activity in CLL or other B-cell malignancies in which this antigen is overexpressed.

No significant financial relationships to disclose.

Recovery of Campylobacter from commercial broiler hatchery trayliners

Previous research has identified Campylobacter as one of the leading causes of foodborne illness. Poultry and poultry products have been identified as a major source of Campylobacter in human infections. Although many risk factors that contribute to Campylobacter levels have been identified, precise identification of the most effective sites for intervention has not been established. Epidemiological studies have identified that Campylobacter in the broiler breeder's reproductive tract, fertile eggs, and 2- to 3-wk-old broilers has the potential to contaminate day-of-hatch chicks. Numerous studies have shown that day-of-hatch broilers are Campylobacter-negative using conventional culture methods. The purpose of the present study was to demonstrate the prevalence of Campylobacter found in day-of-hatch broilers using a peptone water preenrichment followed by conventional Campylobacter culture methods. Using conventional tray liner (hatcheries) culture methods, the isolation distribution of Campylobacter from 8 commercial broiler hatcheries (n = 2,000) was evaluated. A total of 15 tray liners were positive from 3 different hatcheries. Of the 2,000 chick paper pad tray liners sampled, 0.75% were positive for Campylobacter. These data support previous findings indicating the potential for Campylobacter to be spread by vertical transmission. This is the first time that Campylobacter has been recovered from tray liners collected at commercial broiler hatcheries.

Evaluation of Salmonella enteritidis in molting hens after administration of an experimental chlorate product (for nine days) in the drinking water and feeding an alfalfa molt diet

The method most commonly used to induce molting and stimulate multiple egg-laying cycles in laying hens for commercial egg production is to fast the hens. Unfortunately, increased risk of Salmonella enteritidis (SE) infection may result from the use of this method. Methods to stimulate multiple egg-laying cycles without increasing the risk of SE infection are needed. Hens over 50 wk of age were divided into 12 groups of 11 hens each and placed in individual laying cages. One week prior to dietary changes, hens were placed on an 8-h light and 16-h dark photoperiod that continued for the 9-d molt. All hens were challenged orally with 10(6) cfu of SE on the fourth day of the molt. Treatments were nonfed hens with distilled water (NFD), nonfed hens with the experimental chlorate product (ECP, which provided 15 mM chlorate ion) water (NFECP), alfalfa diets with distilled water (ALD), and alfalfa diets with ECP water (ALECP). In the NFD hens, 67% (log10 2.74) of the crops and 94% (log10 5.62) of the ceca were colonized, whereas for the NFECP hens significant reductions to 22% (log10 1.05) of the crops and 61% (log10 2.44) of the ceca were observed. In the ALD hens, 61% (log10 2.52) of the crops and 94% (log10 4.06) of the ceca were colonized. In the ALECP hens, highly significant reductions to 11% (log10 1.26) of the crops and 39% (log10 1.12) of the ceca were observed. When compared with the NFD hens, significant reductions in SE invasion of the ovary, liver, and spleen occurred in all other treatments, except the ovary in the ALD hens. The low alfalfa intake is probably a factor in our lowered protection against SE when compared with previous results. For several parameters, these results suggest that ECP or the combination of ECP and alfalfa may be a useful tool to reduce the risk of SE during an induced molt.

A phase I and pharmacokinetic study of irinotecan in patients with hepatic or renal dysfunction or with prior pelvic radiation: CALGB 9863

BACKGROUND

To ascertain if hepatic or renal dysfunction or prior pelvic radiation (XRT) leads to increased toxicity at a given dose of irinotecan and to characterize the pharmacokinetics of irinotecan and its major metabolites in patients with hepatic or renal dysfunction.

PATIENTS AND METHODS

Adults with tumors appropriate for irinotecan therapy and who had abnormal liver or renal function tests or had prior radiation to the pelvis were eligible. Patients were assigned to one of four treatment cohorts: I, aspartate aminotransferase (AST) > or = 3x upper limit of normal and direct bilirubin <1.0 mg/dl; II, direct bilirubin 1.0-7.0 mg/dl; III, creatinine 1.6-5.0 mg/dl with normal liver function; IV, prior pelvic XRT with normal liver and renal function. Starting with reduced doses of either 145 or 225 mg/m(2), irinotecan was administered every 3 weeks to at least three patients within each cohort. Irinotecan and its metabolites in the blood were measured in all patients.

RESULTS

Thirty-five patients were evaluable for toxicity. No dose-limiting toxicity was seen in cohort I, although only three patients were treated and at a dose of 225 mg/m(2). Patients with elevations of direct bilirubin had dose-limiting toxicities, even though the starting dose was 145 mg/m(2). These same patients appeared to have comparable exposure to the active metabolite SN-38 as normal patients treated with full-dose irinotecan. Patients with elevations of creatinine or with prior pelvic radiotherapy did not appear to have increased risk of toxicity at the doses explored in this study.

CONCLUSIONS

Patients with elevated bilirubin treated with irinotecan have an increased risk of toxicity and a dose reduction is recommended. Patients with elevated AST, creatinine or prior pelvic radiation do not appear to have increased sensitivity to irinotecan, but the data are not adequate to support a specific dosing recommendation.

Observation of terahertz emission from a laser-plasma accelerated electron bunch crossing a plasma-vacuum boundary

Coherent radiation in the 0.3-3 THz range has been generated from femtosecond electron bunches at a plasma-vacuum boundary via transition radiation. The bunches produced by a laser-plasma accelerator contained 1.5 nC of charge. The THz energy per pulse within a limited 30 mrad collection angle was 3-5 nJ and scaled quadratically with bunch charge, consistent with coherent emission. Modeling indicates that this broadband source produces about 0.3 microJ per pulse within a 100 mrad angle, and that increasing the transverse plasma size and electron beam energy could provide more than 100 microJ/pulse.

Nuclear localization of DEDD leads to caspase-6 activation through its death effector domain and inhibition of RNA polymerase I dependent transcription

The death effector domain (DED) is a protein/protein interaction domain only found in proteins that are involved in apoptosis signaling. DEDD is a novel apoptosis signaling molecule that carries an N-terminal DED with complete sequence identity between the murine, rat, bovine and human domains. We previously identified two nuclear localization signals (NLS) responsible for DEDDs nuclear localization when transiently expressed. Using a new anti-DEDD antibody that allows us to stain endogenous DEDD in immunofluorescence microscopy we now detect a significant amount of DEDD in nucleoli of all cells tested. When overexpressed, DEDD localizes to nucleoli-like structures, activates caspase-6 and specifically inhibits RNA polymerase I (Pol I) dependent transcription in vivo as shown by blockage of BrUTP incorporation. The DED in DEDD is sufficient for its DNA binding, caspase-6 activating and Pol I specific transcriptional repressor activity. We have identified a third NLS in DEDD and only mutation of all three NLS generated a protein, DEDD Delta NLS1-3, that mainly localized to the cytoplasm. This protein no longer induced apoptosis, indicating that in contrast to other DED proteins, such as FADD, caspase-8 or c-FLIP, DEDD induces apoptosis from within the nucleus. This effect is abolished when specific point mutations are made within the DED. The DED in DEDD therefore represents a novel domain that is structurally similar to other DEDs but functionally different from classical DEDs found in FADD or caspase-8.

Utility of anti-bacillus Calmette-Guérin antibodies as a screen for organisms in sporotrichoid infections

BACKGROUND

Sporotrichoid infections often present a diagnostic challenge for the dermatopathologist. Therefore an affordable, reliable method of easier recognition of organisms is desired. Recently, immunohistochemical staining with antibodies against Mycobacterium bovis (bacillus Calmette-Guérin, BCG) was found to be useful in identifying various fungi and mycobacteria with minimal background staining.

OBJECTIVE

The purpose of this study was to demonstrate the usefulness of anti-BCG antibodies as a screen for organisms in sporotrichoid infections.

METHODS

Thirteen specimens of suspected sporotrichosis were selected for staining with anti-BCG antibody. Sporotrichoid infection was confirmed by histochemical staining, biopsy, and follow-up results.

RESULTS

Twelve of the 13 specimens stained positively using anti-BCG antibody. Of the 5 cultures done, 2 were positive for M. marinum, and 1 grew Sporothrix schenckii.

CONCLUSION

Immunohistochemical staining with anti-BCG antibody offers another screening method to identify organisms in sporotrichoid infections because of its ease, cost-effectiveness, and simplicity.

Phase I and pharmacokinetic trial of gemcitabine in patients with hepatic or renal dysfunction: Cancer and Leukemia Group B 9565

PURPOSE

To ascertain if hepatic or renal dysfunction leads to increased toxicity at a given dose of gemcitabine and to characterize the pharmacokinetics of gemcitabine and its major metabolite in patients with such dysfunction.

PATIENTS AND METHODS

Adults with tumors appropriate for gemcitabine therapy and who had abnormal liver or renal function tests were eligible. Patients were assigned to one of three treatment cohorts: I-AST level less than or equal to two times normal and bilirubin level less than 1.6 mg/dL; II-bilirubin level 1.6 to 7.0 mg/dL; and III-creatinine level 1.6 to 5.0 mg/dL with normal liver function. Doses were explored in at least three patients within each cohort. Gemcitabine and its metabolite were to be measured in the blood in all patients.

RESULTS

Forty patients were assessable for toxicity. Transient transaminase elevations were observed in many patients but were not dose limiting. Patients with AST elevations tolerated gemcitabine without increased toxicity, but patients with elevated bilirubin levels had significant deterioration in liver function after gemcitabine therapy. Patients with elevated creatinine levels had significant toxicity even at reduced doses of gemcitabine, including two instances of severe skin toxicity. There were no apparent pharmacokinetic differences among the three groups or compared with historical controls.

CONCLUSION

If gemcitabine is used for patients with elevations in AST level, no dose reduction is necessary. Patients with elevated bilirubin levels have an increased risk of hepatic toxicity, and a dose reduction is recommended. Patients with elevated creatinine levels seem to have increased sensitivity to gemcitabine, but the data are not adequate to support a specific dosing recommendation.

Mechanism of the block to hybridization and selfing between the sympatric ascidians Ciona intestinalis and Ciona savignyi

The solitary ascidians Ciona intestinalis and Ciona savignyi co-occur in southern California harbors, but no hybrids have been recognized in nature. Numerous differences in their egg morphology were detected. Homologous (normal outcross) fertilization yielded 96-99% cleavage, where autologous (self) fertilization showed 3% and heterologous (hybrid) fertilization showed 0-1%. Acid treatment (pH 3.2) removed the block to selfing (P < 0.0001) but not hybridization for both species. Heterologous sperm bind to the vitelline coat (VC), but fail to penetrate. Enzymatic removal of the VC resulted in 91-97% cleavage with autologous and heterologous sperm (P < 0.0001). The vitelline coats of the two species differ in lectin binding to surface glycosides. Fertilization in both species is significantly inhibited by the lectins, fucose binding protein (P < 0.0001) and concanavalin A (P < 0.0001), and wheat germ agglutinin inhibits fertilization in C. intestinalis (P < 0.0001) but is without effect on C. savignyi fertilization. Self and hybrid blocks employ different mechanisms including glycoside composition and acid sensitivity.

As others see us, Part 1. Back to basics. Career challenges for the laboratorian

It's time for the laboratorian to emerge from the lab and become an integral part of the healthcare team. We must make others aware of our skills in critical thinking, decision making, quality assurance, and total quality management.

Bedside EKG electrode placement

Inaccurate or inconsistent placement of 12-lead EKG and bedside EKG monitoring electrodes can lead to disastrous diagnostic errors in cardiac patients. A knowledgeable and competent nursing staff can facilitate optimal diagnosis and treatment of the patient's problem through accurate placement of the 12-lead EKG and bedside EKG monitoring electrodes.

The effect of internal visualization on digit span performance

Fifty-two subjects were randomly assigned to one of four conditions according to a 2 x 2 factorial design in order to determine the effect of internal visualization on short-term memory for digits as measured by the Wechsler Digit Span subtest. Surprisingly, internal visualization (imaging with eyes closed) was found not to affect Digit Span performance significantly.

X-ray absorption studies of yeast copper metallothionein

The local structures of the metal sites in copper metallothionein from Saccharomyces cerevisiae have been investigated by x-ray absorption spectroscopy at the copper and sulfur K edges. Analysis of the EXAFS (extended x-ray absorption fine structure) data indicates that each copper is trigonally coordinated to sulfur at a distance of 2.23 A. Cu-Cu interactions at 2.7 and 3.9 A have also been tentatively identified. Sulfur K edge data are compatible with cysteinyl thiolates bridging each of the eight Cu(I) ions. The data support a model for the copper cluster in yeast metallothionein consisting of a Cu8S12 core. EXAFS data on two specifically engineered carboxyl-terminal truncated mutants reveal that the copper coordination in the mutants is similar to that observed in the wild-type protein.