Second Malignancy Probabilities in Patients With Breast Cancer Treated With Conventional Versus Hypofractionated External Beam Radiation Therapy in the Adjuvant Setting

AIMS

For women with breast cancer, seminal studies have shown that adjuvant hypofractionated external beam radiation therapy (hEBRT) maintains similar outcomes and may reduce overall costs compared with conventionally fractionated external beam radiation therapy (cEBRT). However, it is unclear whether hEBRT may be associated with differential risk of development of radiation-induced second malignancies compared with cEBRT. Because the occurrence of second malignancies is small, large databases may improve our understanding of the relative risk of second malignancies between hEBRT and cEBRT.

MATERIALS AND METHODS

Using the National Cancer Database, we carried out a retrospective cohort analysis of women diagnosed with non-metastatic, stage 0-III breast cancer from 2004 to 2017. All patients had a lumpectomy or mastectomy and a follow-up time of at least 60 months after diagnosis. The probability of second malignancies in women receiving adjuvant cEBRT or hEBRT was compared using multivariable logistic regression adjusting for sociodemographic, geographical, clinical and treatment factors, allowing for relative (but not absolute) comparison of second malignancy risk. Temporal sensitivity analyses stratified by year of diagnosis and length of follow-up time were also conducted.

RESULTS

Of the 125 228 women in our study, 115 576 (92.3%) received cEBRT and 9652 (7.71%) received hEBRT. The median age of the cohort was 60 (interquartile range 51-68) years at diagnosis and the median follow-up time was 99.61 (interquartile range 77.5-128.49) months. Upon adjusting for sociodemographic and clinical factors, patients who received hEBRT had no difference in relative risk than patients who received cEBRT (odds ratio 0.937, 95% confidence interval 0.869-1.010, P = 0.091). In analyses stratified by year of diagnosis, and stratified by length of follow-up, there was no difference in second malignancy probability between patients who completed hEBRT and patients who completed cEBRT.

CONCLUSIONS

In this analysis of over 120 000 women with non-metastatic breast cancer, hEBRT was not associated with different odds of developing second malignancies compared with cEBRT. Our findings may inform patient counselling in the choice of radiation regimens for breast cancer and further support the safety of hypofractionated regimens for breast cancer.

Trends in Utilization and Medicare Spending on Shorter vs. Longer Radiotherapy Courses for Breast and Prostate Cancer

PURPOSE/OBJECTIVE(S)

Evidence based research supports shorter, similarly efficacious, and potentially more cost-effective hypofractionated treatment regimens in many clinical scenarios for breast cancer (BC) and prostate cancer (PC). However, practice patterns of hospital-affiliated and standalone facilities vary considerably. We used the most recent Centers for Medicare and Medicaid Services data to assess trends in radiotherapy (RT) costs and practice patterns among episodes of BC and PC.

MATERIALS/METHODS

We performed a retrospective cohort analysis of all external beam episodes for BC and PC from 2015-2019. For patients with BC, receipt of shorter-course RT (SCRT) was defined as receiving 11-20 fractions of external beam radiation therapy (including IMRT), and conventional RT as >20 fractions. For patients with PC, SBRT was defined as receipt of <10 fractions and moderate hypofractionation as 10-30 fractions (SCRT defined as SBRT and moderate hypofractionation), and >30 fractions for conventional RT. Total Medicare spending were defined as the sum of winsorized payment for professional and technical services furnished during the episode in 2019 dollars. Multivariable logistic regression defined adjusted odds ratios (ORs) of receipt of SCRT over conventional RT by treatment modality, age, year of diagnosis, type of practice, as well as a time*treatment setting interaction term. Medicare spending was evaluated using multivariable linear regression controlling for duration of RT regimen (SCRT vs conventional) in addition to the covariables above.

RESULTS

Of 47,283 BC episodes and 45,917 PC episodes, 23,705 (50.13%) and 9,125 (19.87%) were SCRT, respectively. Median total spending for SCRT among BC episodes was $9,324 (IQR, $7,916-$10,921) vs. $13,372 (IQR, $11,511-$15,283) for conventional RT. Among PC episodes, median total spending was $12,917 (IQR, $9,551-$15,271) for SBRT, $18,944 (IQR, $16,530-$20,615) for moderate hypofractionation, and $26,935 (IQR, $25,062-$28,959) for conventional RT. For both cancers, total episode spending was reduced with SCRT utilization [(BC adjusted β, -$4,200; p<0.001), (PC adjusted β, -$8,747; p<0.001)], older age, and non-IMRT-based treatment. On logistic regression, receipt of SCRT was associated with older age among both BC and PC episodes (p<0.001), as well as treatment at hospital-affiliated over freestanding sites [(BC OR [95% CI], 1.41 [1.29-1.54], p<0.001), (PC OR, 1.64 [1.39-1.94], p<0.001)].

CONCLUSION

In this evaluation of all BC and PC RT episodes from 2015-2019, we found that shorter-course RT resulted in increased cost-savings vs. conventional RT. SCRT was also more common in hospital-affiliated sites. Further research is needed to devise payment incentives that encourage SCRT when clinically applicable in the two most common sites treated with RT, and to prospectively study cost-effective hypofractionation in other disease sites.

Disparities in Breast-Conserving Therapy vs. Mastectomy among Asian American and Pacific Islander Women

PURPOSE/OBJECTIVE(S)

Multiple randomized trials support the use of breast-conserving therapy (BCT), defined as lumpectomy followed by adjuvant radiotherapy, as an alternative to mastectomy for definitive treatment of early-stage (T1-2N0) breast cancer. However, data suggest that Asian American, Native Hawaiian, and Pacific Islander (AANHPI) may undergo mastectomy at higher rates than BCT and may experience barriers to receipt of BCT. The purpose of this study was to examine BCT utilization by disaggregated AANHPI groups to identify differences in receipt of mastectomy versus BCT.

MATERIALS/METHODS

The 2004-2017 National Cancer Database was queried to identify women age ≥18 years old diagnosed with cT1-2N0M0 breast cancer treated with either BCT or mastectomy without post-mastectomy radiation therapy. Women were classified based on self-reported race. Multivariable logistic regression defined adjusted odds ratios (OR) assessing the association between race and receipt of BCT versus mastectomy for all patients and separately by cT1-2 stage. All models were adjusted for relevant sociodemographic and clinical factors.

RESULTS

Of 794,403 women with cT1-2N0M0 breast cancer, 239,801 (30%) received mastectomy and 554,602 (70%) received BCT. After adjusting for clinical and sociodemographic factors, AANHPI women had greater odds of receiving mastectomy over BCT, compared to White women (OR [95% CI], 1.35 [1.30-1.39]; p<0.001). In contrast, Black women were less likely than White women to receive mastectomy (0.86 [0.84-0.87]; p<0.001). Upon disaggregation, Chinese, Japanese, Filipino, Korean, Vietnamese, and Asian Indian & Pakistani women were more likely to receive mastectomy over BCT compared to White women (p<0.001 for all). Treatment at academic (1.30 [1.27-1.32]), integrated (1.24 [1.21-1.27]), and comprehensive community cancer centers (1.15 [1.13-1.17]) were all associated with greater odds of mastectomy compared to treatment at community cancer programs (all p<0.001). Greater distance from treatment facility (≥50 mi. vs. 0 to <10 mi. [reference], OR 1.50 [1.47-1.53]) and cT2 disease (1.85 [1.82-1.87]) were also associated with greater odds of receiving mastectomy (all p<0.001).

CONCLUSION

In this evaluation of women with early-stage breast cancer, women from several AANHPI groups were more likely to receive mastectomy (as opposed to BCT) compared to White women. While sociocultural preferences, differences in access to and interest in reconstruction, as well as prevalent tumor-to-breast ratios may partially explain the disparities, collectively our data suggest an ongoing need for greater patient involvement in shared-decision making, particularly in vulnerable and understudied Asian populations.

Carbon-Based Fluorescent Nano-Biosensors for the Detection of Cell-Free Circulating MicroRNAs

Currently, non-communicable diseases (NCDs) have emerged as potential risks for humans due to adopting a sedentary lifestyle and inaccurate diagnoses. The early detection of NCDs using point-of-care technologies significantly decreases the burden and will be poised to transform clinical intervention and healthcare provision. An imbalance in the levels of circulating cell-free microRNAs (ccf-miRNA) has manifested in NCDs, which are passively released into the bloodstream or actively produced from cells, improving the efficacy of disease screening and providing enormous sensing potential. The effective sensing of ccf-miRNA continues to be a significant technical challenge, even though sophisticated equipment is needed to analyze readouts and expression patterns. Nanomaterials have come to light as a potential solution as they provide significant advantages over other widely used diagnostic techniques to measure miRNAs. Particularly, CNDs-based fluorescence nano-biosensors are of great interest. Owing to the excellent fluorescence characteristics of CNDs, developing such sensors for ccf-microRNAs has been much more accessible. Here, we have critically examined recent advancements in fluorescence-based CNDs biosensors, including tools and techniques used for manufacturing these biosensors. Green synthesis methods for scaling up high-quality, fluorescent CNDs from a natural source are discussed. The various surface modifications that help attach biomolecules to CNDs utilizing covalent conjugation techniques for multiple applications, including self-assembly, sensing, and imaging, are analyzed. The current review will be of particular interest to researchers interested in fluorescence-based biosensors, materials chemistry, nanomedicine, and related fields, as we focus on CNDs-based nano-biosensors for ccf-miRNAs detection applications in the medical field.

Bioanalytical Applications of Graphene Quantum Dots for Circulating Cell-Free Nucleic Acids: A Review

Graphene quantum dots (GQDs) are carbonaceous nanodots that are natural crystalline semiconductors and range from 1 to 20 nm. The broad range of applications for GQDs is based on their unique physical and chemical properties. Compared to inorganic quantum dots, GQDs possess numerous advantages, including formidable biocompatibility, low intrinsic toxicity, excellent dispensability, hydrophilicity, and surface grating, thus making them promising materials for nanophotonic applications. Owing to their unique photonic compliant properties, such as superb solubility, robust chemical inertness, large specific surface area, superabundant surface conjugation sites, superior photostability, resistance to photobleaching, and nonblinking, GQDs have emerged as a novel class of probes for the detection of biomolecules and study of their molecular interactions. Here, we present a brief overview of GQDs, their advantages over quantum dots (QDs), various synthesis procedures, and different surface conjugation chemistries for detecting cell-free circulating nucleic acids (CNAs). With the prominent rise of liquid biopsy-based approaches for real-time detection of CNAs, GQDs-based strategies might be a step toward early diagnosis, prognosis, treatment monitoring, and outcome prediction of various non-communicable diseases, including cancers.

Constraints on Dark Matter Properties from Observations of Milky Way Satellite Galaxies

We perform a comprehensive study of Milky Way (MW) satellite galaxies to constrain the fundamental properties of dark matter (DM). This analysis fully incorporates inhomogeneities in the spatial distribution and detectability of MW satellites and marginalizes over uncertainties in the mapping between galaxies and DM halos, the properties of the MW system, and the disruption of subhalos by the MW disk. Our results are consistent with the cold, collisionless DM paradigm and yield the strongest cosmological constraints to date on particle models of warm, interacting, and fuzzy dark matter. At 95% confidence, we report limits on (i) the mass of thermal relic warm DM, m_{WDM}>6.5  keV (free-streaming length, λ_{fs}≲10h^{-1}  kpc), (ii) the velocity-independent DM-proton scattering cross section, σ_{0}<8.8×10^{-29}  cm^{2} for a 100 MeV DM particle mass [DM-proton coupling, c_{p}≲(0.3  GeV)^{-2}], and (iii) the mass of fuzzy DM, m_{ϕ}>2.9×10^{-21}  eV (de Broglie wavelength, λ_{dB}≲0.5  kpc). These constraints are complementary to other observational and laboratory constraints on DM properties.

Is higher power shorter duration radiofrequency energy is better than lower power longer duration strategy in catheter ablation of atrial fibrillation A meta-analysis

Background

An ideal strategy for radiofrequency ablation (RFA) of atrial fibrillation (AF) in the left atrium should be efficient enough to achieve transmural lesions in left atrium with no or minimal collateral tissue damage. Resistive heating of high power short duration (HPSD) RFA has been found to result in lesions larger in width but lesser in depth compared to lower power longer duration (LPLD) RFA in some experimental studies.

Purpose

This meta-analysis was performed to compare procedural, short-term and long-term outcomes of HPSD versus LPLD RFA of AF.

Methods

PubMed, Embase and Cochrane databases were systematically reviewed. Five observational studies meeting criteria were included in the meta-analysis. All the studies scored six or more points in the New-castle Ottawa scale. There were considerable variations in the ablation strategies across the studies. However, radiofrequency power more than 40W was considered as high power. Hypergeometric model with exact likelihood function was utilized for statistical analysis.

Results

Baseline parameters and ablation details have been depicted in Table 1. 740 patients with HPSD and 287 patients with LPLD ablation strategies, were followed up from 6 to 30 months. Total procedural time (P value &lt;0.0001) and ablation time (P value &lt;0.0001) were significantly lower in the HPSD group than LPLD group. However, the fluoroscopy time was similar (P value = 0.09) in both the groups (Table 2). There were no occurrences of atrio-esophageal fistula or pulmonary venous stenosis in any of the studies. Cardiac tamponade (P value = 0.56), stroke (P value = 0.70) and AF recurrences (P value = 0.81), were similar in both groups (Table 2).

Conclusion

Newer HPSD and conventional LPLD RFA, both the strategies are very safe procedure for treatment of RFA with low to no procedural complications. AF recurrence rates were reasonably high irrespective of ablation strategies, however, no strategy scored statistically better over the other one. Large randomized multi-centric studies with long-term follow up are needed to test the theoretical advantage of HPSD ablation over the traditional ablation strategy of AF.

Funding Acknowledgement

Type of funding source: None

New approaches for post-vaccination surveillance of foot-and-mouth disease

Foot-and-mouth disease (FMD) is a contagious and important transboundary disease of cloven-hoofed animals and ruminants. In ruminants, an animal is considered as a foot-and-mouth disease virus (FMDV) carrier if a live FMDV/FMDV RNA is obtained from the oro-pharyngeal fluid (OPF) beyond 28 days after infection. These carrier animals may pose a risk for causing outbreaks in healthy animals. Moreover, it is important to conduct serosurveillance to know the virus circulation. In the present study, an ELISA was developed using field samples to detect FMDV specific secretory IgA antibodies. These samples were also tested for the presence of FMDV RNA using quantitative real-time PCR (qRT-PCR). It was found that more carrier animals were detected by IgA ELISA in comparison to qRT-PCR. Thus, IgA ELISA is an important tool to detect FMD carriers. An ELISA based on detection of antibodies against FMDV 2B non-structural protein (NSP) was also used to confirm the results obtained from screening of 3AB3 NSP ELISA. These two new approaches (IgA ELISA and 2B ELISA) form important tools for detection of carriers and virus circulation, respectively, during FMD eradication program. Keywords: foot-and-mouth disease virus; carriers; IgA; 2B non-structural protein; 3AB3 non-structural protein.

Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Taming Influenza Virus: Role of Antisense Technology

Human Influenza A virus (IAV), a relatively newer threat to mankind, is becoming invincible due to non availability of proper antiviral drug or effective long lasting vaccine against it. All existing measures to control this virus are overpowered by the phenomena of genetic shift and drift shown by Influenza A virus (IAV). Throughout the world, researchers are exploring the therapeutic potential of antisense technology (AST) to fight against this genetically variable virus. Antisense technology refers to the laboratory manipulation and/or modification of DNA or RNA so that its components (nucleotides) hybridize with target nucleic acid or mRNA or protein itself to inhibit the protein finally encoded. RNA inhibitory (RNAi) mechanism (particularly siRNA) seems to be the most promising among the different agents of AST. However, other agents like oligonucleotides, ribozymes and DNAzymes also show great potential. Decoys and aptamers, alone or in conjunction with other agents, are also being explored to inhibit the replication of virus. Presently, most of these agents have passed initial level of in vitro and in vivo experiments, passing through various levels of clinical trials but none of them has been approved for human purpose till date. Present review consolidates the efforts of researchers worldwide in this particular field and discusses the future perspectives this technology holds, to tame this notorious virus. Day by day, various areas of this technology are being explored and the day is not far when this chemical entity will reach from "bench to bedside".

Wide-Field Lensing Mass Maps from Dark Energy Survey Science Verification Data

We present a mass map reconstructed from weak gravitational lensing shear measurements over 139  deg2 from the Dark Energy Survey science verification data. The mass map probes both luminous and dark matter, thus providing a tool for studying cosmology. We find good agreement between the mass map and the distribution of massive galaxy clusters identified using a red-sequence cluster finder. Potential candidates for superclusters and voids are identified using these maps. We measure the cross-correlation between the mass map and a magnitude-limited foreground galaxy sample and find a detection at the 6.8σ level with 20 arc min smoothing. These measurements are consistent with simulated galaxy catalogs based on N-body simulations from a cold dark matter model with a cosmological constant. This suggests low systematics uncertainties in the map. We summarize our key findings in this Letter; the detailed methodology and tests for systematics are presented in a companion paper.

Viral aetiology of acute lower respiratory tract illness in hospitalised paediatric patients of a tertiary hospital: one year prospective study

CONTEXT

Acute lower respiratory tract infections (ALRI), ranked as the second leading cause of death are the primary cause of hospitalisation in children. Viruses are the most important causative agents of ALRI.

AIM

To study the viral aetiology of ALRI in children at a tertiary care hospital.

SETTING AND DESIGN

One year prospective observational study in a tertiary care hospital of King George's Medical University, Lucknow.

MATERIAL AND METHODS

Nasopharyngeal aspirate (NPA) was collected from children admitted with signs and symptoms of ALRI who were aged 0-14 years. Samples were transported to the laboratory at 4°C in viral transport media and processed for detection of respiratory syncytial virus (RSV) A and B, influenza virus A and B, adenovirus (ADV), human Boca virus (HBoV), human metapneumo virus (hMPV) and parainfluenzavirus 1, 2, 3 and 4 using mono/multiplex real-time polymerase chain reaction (RT-PCR). STATA was used for statistical analysis.

RESULTS

In one year, 188 NPAs were screened for respiratory viruses, of which 45.7% tested positive. RSV was most commonly detected with 21.3% positivity followed by measles virus (8.5%), influenza A virus (7.4%), ADV (5.3%), influenza B virus (1.6%), hMPV (1.1%) and HBoV (0.5%). Month wise maximum positivity was seen in December and January. Positivity rate of RSV was highest in children aged < 1 year, which decreased with increase in age, while positive rate of influenza virus increased with increasing age.

CONCLUSION

The occurrence of viral predominance in ALRI is highlighted.

Light induced toxicity of merocyanine 540-silica nanoparticle complex

The electrostatic binding between the negatively charged lipophilic dye Merocyanine 540 and silica nanoparticles having 3-amino propyl groups at the surface has been characterized using absorption and fluorescence spectroscopy. The binding of the dye with the nanoparticle resulted in significant changes in its absorption spectra. Further the fluorescence intensity and lifetime gets enhanced by more than an order of magnitude. The results obtained suggest that this is due to the reduced photoisomerization rate of the dye bound to the nanoparticle. Consistent with the expectation that a reduction in the photoisomerization rate should enhance the singlet oxygen yield of the dye via intersystem crossing, the light induced toxicity of the dye-nanoparticle complex (tested with MCF cells) was observed to be higher compared to the free dye.

Hydrogen Bonding Properties of Coumarin 151, 500, and 35: The Effect of Substitution at the 7-Amino Position

The steady-state spectral properties (absorption and emission) of three structurally similar Coumarin dyes, C151, C500, and C35 were investigated in 13 different solvents. A Kamlet-Taft (KT) analysis of the spectral peak frequencies reveals that, in addition to polarity, hydrogen bonding between the carbonyl oxygen and a protic solvent in the excited state imparts maximum stabilization for C151 and minimum for C35, while that for C500 lies in between. The spectral properties of the three dyes in two solvents, chloroform and THF, which have similar polarity in the KT scale but have only hydrogen-bond donor (chloroform) and hydrogen-bond acceptor (THF) properties, are seen to be sensitive to the substitution pattern at the 7-amino position. In addition, a slow emission spectral relaxation is observed for C151 and C500 having a time constant of approximately 500 ps in chloroform. For C35 this was too fast to be detected by the time resolution of our setup. The exact reason for this slow spectral relaxation in chloroform is unclear at present, and further studies are needed to understand clearly the structural effects on the hydrogen bonding dynamics of these dyes.

Experimental investigation of perturbation Monte-Carlo based derivative estimation for imaging low-scattering tissue

Experimental results for imaging the low-scattering tissue phantoms based on the derivative estimation through perturbation Monte-Carlo (pMC) method are presented. It is proven that pMC-based methods give superior reconstructions compared to diffusion-based reconstruction methods. An easy way to estimate the Jacobian using analytical expression obtained from perturbation Monte-Carlo method is employed. Simulation studies on the same objects, considered in the experiment, are performed and corresponding results are found to be in reasonable agreement with the experimental studies. It is shown that inter-parameter cross talk in diffusion based methods lead to false results for the low-scattering tissue, where as the pMC-based method gives accurate results.

Statistics of Dark Matter Halos from Gravitational Lensing

We present a new approach to measure the mass function of dark matter halos and to discriminate models with differing values of Omega through weak gravitational lensing. We measure the distribution of peaks from simulated lensing surveys and show that the lensing signal due to dark matter halos can be detected for a wide range of peak heights. Even when the signal-to-noise ratio is well below the limit for detection of individual halos, projected halo statistics can be constrained for halo masses spanning galactic to cluster halos. The use of peak statistics relies on an analytical model of the noise due to the intrinsic ellipticities of source galaxies. The noise model has been shown to accurately describe simulated data for a variety of input ellipticity distributions. We show that the measured peak distribution has distinct signatures of gravitational lensing, and its non-Gaussian shape can be used to distinguish models with different values of Omega. The use of peak statistics is complementary to the measurement of field statistics, such as the ellipticity correlation function, and is possibly not susceptible to the same systematic errors.

An oxaloacetate decarboxylase homologue protein influences the intracellular survival of Legionella pneumophila

Legionella pneumophila is a facultative intracellular parasite which is able to survive in various eukaryotic cells. We characterised a Tn5-mutant of the L. pneumophila Corby strain and were able to identify the insertion site of the transposon. It is localised within an open reading frame which shows high homology to the alpha-subunit of the oxaloacetate decarboxylase (OadA) of Klebsiella pneumoniae. The OadA homologous protein of L. pneumophila was detected in the wild-type strain by Western blotting. Since the intracellular multiplication of the oadA- mutant strain is reduced in guinea pig alveolar macrophages and human monocytes, it is concluded that the oadA gene product has an effect on the intracellular survival of L. pneumophila.

A cyclophilin-like peptidyl-prolyl cis/trans isomerase from Legionella pneumophila--characterization, molecular cloning and overexpression

Legionella pneumophila is the causative agent of a severe form of pneumonia in humans (Legionnaires' disease). A major virulence factor, the Mip protein (FK506-binding protein, FKBP25mem), belongs to the enzyme family of peptidyl-prolyl cis/trans isomerases (PPlases). Here we show that L. pneumophila Philadelphia I possesses an additional cytoplasmic PPlase at a level of enzyme activity comparable to that of FKBP25mem. The N-terminal amino acid sequence of the purified protein was obtained by Edman degradation and showed that the protein is a member of the cyclophilin family of PPlases. The Icy gene (Legionella cyclophilin) was cloned and sequenced. It encodes a putative 164-amino-acid protein with a molecular mass of 17968 Da called L. pneumophila cyclophilin 18 (L.p.Cyp18). Amino acid sequence comparison displays considerable similarity to the cytoplasmic and the periplasmic cyclophilins of Escherichia coli with 60.5% and 51.5% identity, respectively. The substrate specificity and inhibition by cyclosporin A revealed a pattern that is typically found for other bacterial cyclophilins. An L. pneumophila Cyp18 derivative with a 19-amino-acid polypeptide extension including a 6-histidine tag and an enterokinase cleavage site exhibits PPlase activity when produced at high levels in E. coli K-12. After removal of the extension by enterokinase, the properties of the recombinant Cyp18 were indistinguishable from those of the authentic enzyme. In order to investigate the influence of Cyp18 on intracellular survival of L. pneumophila an Icy-negative L. pneumophila strain was constructed. Compared with the wild-type strain, the mutant did not exhibit a significant phenotype but was 10-fold less invasive for Acanthamoeba castellanii. Like human cyclophilin, the L. p. Cyp18 exhibits nuclease activity, but this enzymatic activity does not appear to be linked with the native structure of the protein.

Cardiopulmonary function and autologous bone marrow transplantation: results and predictive value for respiratory failure and mortality. The University of Nebraska Medical Center Bone Marrow Transplantation Pulmonary Study Group

Cardiopulmonary complications are a major cause of morbidity and mortality in patients undergoing high-dose therapy with stem cell transplant support. Since exercise tolerance testing (ETT) assesses the cardiopulmonary reserve of an individual, we hypothesized that ETT performed prior to transplant would predict respiratory failure and mortality and would be a superior predictor over resting cardiopulmonary function tests. We performed a retrospective study of 191 lymphoma patients who underwent ETT prior to transplant between 1 June 1990 and 31 December 1992 and compared the results of ETT with resting pulmonary function tests (PFT) and resting cardiac ejection fraction (EF). ETT revealed that cardiac, pulmonary and combined cardiopulmonary limitation were observed in 31, 20 and 16% of the patients, respectively, with a gas diffusion-type limitation being the most common exercise limitation. Resting PFT were abnormal in 58% of patients with a diffusion defect being the most common abnormality. Low EF was observed in 6.8% of patients. Twelve patients eventually required mechanical ventilation post-transplant with only the resting diffusion PFT predictive of this complication. There were five early deaths that were attributable to respiratory failure and neither resting nor ETT studies were predictive of these deaths. ETT and EF performed prior to transplant in lymphoma patients undergoing autologous transplant do not predict for either respiratory failure or short-term mortality. Our findings may be due to the rather low incidence of respiratory failure (6.3%) and low early mortality from cardiopulmonary complications (2.6%) seen in our patient population.

Study on in vitro stability of polymerized liposomes

We studied the stability of liposomes composed of polymerized phospholipid, 1,2-bis-(octadeca-2,4-dienoyl)-sn-glycero-3-phosphocholine (DENPC), to pH changes and the presence of bile salts, monitoring the leakage of 3H-sucrose entrapped in liposomes. The stability of polymerized DENPC-liposomes to acidic media (pH 3.3 and 2), and the presence of bile salts (20 mM), was much higher than that of nonpolymerized DENPC-liposomes and liposomes composed of conventional phospholipids. The stability of polymerized DENPC-liposomes was increased in the presence of carboxymethyl chitin (CM-chitin).

An assessment of short-acting hypnotics

Insomnia, the experience of poor quality or quantity of sleep, is a very common complaint. Approximately 65 million adults (36% of the American population) complain of poor sleep, and of this group, 25% have insomnia on a chronic basis. These chronic insomniacs not only report higher rates of difficulty with concentration, memory and the ability to cope with minor irritations but also have 2.5 times more fatigue-related automobile accidents than do good sleepers. Despite its ubiquity, insomnia is often either untreated or inadequately treated. Short-acting hypnotics are advocated for transient insomnia, which lasts less than 3 weeks, and in patients with chronic insomnia as an adjunctive treatment where nonpharmacological treatment is not sufficient to alleviate insomnia and the related daytime detrimental effects. The putative adverse effects of hypnotics must be weighted against the severe health effects caused by continued sleep impairment. If hypnotic agents are used, they should be taken nightly only for brief use, or intermittently in longer term use. Benzodiazepines, zolpidem and zopiclone (in countries where the latter is available) remain the recommended hypnotic agents, although in the past few years there has been much criticism in lay magazines and on television about the use of benzodiazepines. However, this review of the efficacy and tolerability data of the short-acting hypnotics suggests that triazolam is comparable with other short-acting hypnotics at equipotent doses while taking into consideration that for every hypnotic, different study populations display different degrees of efficacy. In addition, contrary to previous suggestions that such adverse effects are rebound insomnia and anterograde amnesia are unique to triazolam, hypnotically equivalent doses of tirazolam have not been shown to produce these effects more frequently than other short-acting hypnotics. The newer nonbenzodiazepine hypnotics seem to be equally efficacious as the short-acting benzodiazepines; whether they will truly have a better adverse effect profile will be determined as more clinical experience accumulates. Despite the availability, relative safety and efficacy of these newer hypnotic agents, they should not be perceived as the sole treatment for insomnia and should be used in conjunction with nonpharmacological techniques (such as adherence to good sleep hygiene, sleep restriction, stimulus control and biofeedback therapy).

TNF-alpha and IL-1 beta upregulate nitric oxide-dependent ciliary motility in bovine airway epithelium

Airway epithelial cells can be modulated by cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta that are released from inflammatory cells. Since ciliary motility is an important host defense function of airway epithelium, we hypothesized that cytokines, released from lung macrophages, upregulate ciliary motility. To test this hypothesis, ciliary beat frequency (CBF) was measured by video microscopy in cultured ciliated bovine bronchial epithelial cells (BBECs) incubated for 24 h with bovine alveolar macrophage-conditioned medium (AM-CM). Exposure to AM-CM resulted in a delayed (> or = 2 h) increase in CBF that was maximal after 24 h exposure (13.70 +/- 0.43 for AM-CM vs. 9.44 +/- 0.24 Hz for medium; P < 0.0001) and which was largely blocked by either anti-TNF-alpha or anti-IL-1 beta antibodies. rTNF-alpha or rIL-1 beta similarly increased CBF, which could be blocked by preincubation with either anti-rTNF-alpha or anti-rIL-1 beta antibodies. Preincubation of BBECs with actinomycin D or dexamethasone also blocked rTNF-alpha- and rIL-1 beta-induced cilia stimulation, suggesting that new protein synthesis is required for cytokine-induced upregulation of CBF. Since NO is known to upregulate ciliary motility and cytokines can induce NO synthase (NOS), we hypothesized that TNF-alpha and IL-1 beta increase CBF by inducing NOS in BBECs. The cilia stimulatory effects of TNF-alpha or IL-1 beta were inhibited by NG-monomethyl-L-arginine, a competitive NOS inhibitor, and restored by the addition of either L-arginine, an NOS substrate, or sodium nitroprusside, an NO donor.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of airway epithelial cell ciliary beat frequency by nitric oxide

NOS activity has been recently described in airway epithelial cells. Because these cells are often ciliated we hypothesized that NO modulates airway ciliary beating. CBF was measured in cultured BBECs using video microscopy. L-NMMA, a NOS inhibitor, caused a 40% decrease in CBF following pre-stimulation with isoproterenol (8.5 +/- 0.3 Hz vs 14.6 +/- 0.2 Hz; p < 0.0001) which lasted approximately 60 minutes. Similar attenuation in CBF after isoproterenol pre-treatment was observed with another NOS inhibitor, L-NAME. NOS inhibitor-induced CBF slowing was also observed when cells were pre-stimulated with either bradykinin or substance P and was completely reversed by L-arginine or SNP but not by D-arginine. These observations demonstrate a novel NO-dependent mechanism that upregulates ciliary motility in response to stimulation.

Crossed renal ectopia with pelvic lipomatosis: a new syndrome involving chromosome 1

An 18-year-old male patient is described who possesses both kidneys on one side (crossed renal ectopia), together with pelvic lipomatosis. In general, lipomatosis is benign, but here the tissue shows the rare feature of malignancy. Chromosomally, the patient is typically characterised by somatic translocations involving chromosome 1 (37% metaphases); these almost always exhibit a whole chromosome translocation with chromosome 6 (35%), although involvement of chromosome 1 with chromosome 8 is present in 2% of metaphases. Other chromosomal features encountered in Giemsa-stained and G-banded preparations from lymphocyte cultures include the prevalence of a small Y chromosome in 25% of metaphases, the presence of marker dots in 20%, and acrocentric associations in 8%-10% of metaphases. However, more than 50% of metaphases have a normal 46XY karyotype with a normal-sized Y-chromosome. Crossed renal ectopia with pelvic lipomatosis can therefore be assigned to a new syndrome characterised by a whole-chromosome translocation involving chromosomes 1 and 6.

Ampicillin tolerance of Legionella pneumophila for counter-selection of transconjugants in heterospecific matings with Escherichia coli donors

Legionella pneumophila, the causative agent of Legionnaires' disease is sensitive to ampicillin. However, the slowly growing bacteria are not killed even by high doses of this antibiotic. This natural tolerance was used for counter-selection of trans-conjugants in heterospecific matings with Escherichia coli as donor. This approach is useful for gentic manipulations in Legionella, as it avoids the use of antibiotic-resistant variants, which have to be tested for full virulence before use.