Search

We present here the details of a phase retrieval technique that provides access to multidimensional modalities that are not currently available using existing interferometric techniques. The development of multidimensional optical spectroscopy has facilitated significant insights into electronic processes in physics, chemistry, and biology. The versatility and number of available techniques are, however, significantly limited by the requirement that the detection be interferometric. Many of these techniques are closely related to the vast range of multidimensional NMR spectroscopies, which revolutionized analytical chemistry more than 30 years ago. We focus here on the specific case of two-color multidimensional spectroscopy (analogous to heteronuclear NMR) and discuss the details of an iterative algorithm that recovers the relative phase relationships required to perform the Fourier transformation and find the unique solution for the 2D spectrum. A detailed guide is provided that describes the practical implementation of such algorithms. The effectiveness and accuracy of the phase retrieval process are assessed for simulated one- and two-color experiments. It is also compared with one-color experimental data for which the target phase information has been obtained independently by interferometry. In all the cases, the present algorithm yields results that compare well with the solutions obtained by other means. There are, however, some limitations and potential pitfalls that are identified and discussed. We conclude with a discussion of the potential applications and further advances that may be possible by adopting iterative phase retrieval algorithms of the type discussed here. [ABSTRACT FROM AUTHOR]

A comparison of the solvation response functions obtained from single-wavelength and from spectral-reconstruction measurements is provided. The model used in this study is based on a linear free-energy relationship.

CD44 is a multifunctional protein involved in cell adhesion and signaling. The role of CD44 in prostate cancer (PCa) development and progression is controversial with studies showing both tumor-promoting and tumor-inhibiting effects. Most of these studies have used bulk-cultured PCa cells or PCa tissues to carry out correlative or overexpression experiments. The key experiment using prospectively purified cells has not been carried out. Here we use FACS to obtain homogeneous CD44+ and CD44− tumor cell populations from multiple PCa cell cultures as well as four xenograft tumors to compare their in vitro and in vivo tumor-associated properties. Our results reveal that the CD44+ PCa cells are more proliferative, clonogenic, tumorigenic, and metastatic than the isogenic CD44− PCa cells. Subsequent molecular studies demonstrate that the CD44+ PCa cells possess certain intrinsic properties of progenitor cells. First, BrdU pulse-chase experiments reveal that CD44+ cells colocalize with a population of intermediate label-retaining cells. Second, CD44+ PCa cells express higher mRNA levels of several ‘stemness’ genes including Oct-3/4, Bmi, β-catenin, and SMO. Third, CD44+ PCa cells can generate CD44− cells in vitro and in vivo. Fourth, CD44+ PCa cells, which are AR−, can differentiate into AR+ tumor cells. Finally, a very small percentage of CD44+ PCa cells appear to undergo asymmetric cell division in clonal analyses. Altogether, our results suggest that the CD44+ PCa cell population is enriched in tumorigenic and metastatic progenitor cells.Oncogene (2006) 25, 1696–1708. doi:10.1038/sj.onc.1209327; published online 30 January 2006 [ABSTRACT FROM AUTHOR]

On October 4, 2003, the District of Columbia Department of Health (DOH) held a Strategic National Stockpile (SNS) exercise designed to test its plan for operating mass dispensing centers during a bioterrorist attack or other emergency. The main goals of the exercise were to maximize the throughput of the dispensing plan and improve dispensing procedures. These goals are important for quantifying the resources (eg, numbers and types of staff) necessary to respond to different types and sizes of events, as well as for minimizing the potential for errors or confusion in dispensing medications. We set up the dispensing center according to the District's SNS plan and recruited volunteers to role-play potentially exposed residents. During the exercise, we collected detailed data on the service times for each step in the dispensing process. We also collected observations from exercise participants and observers. We found that the DOH dispensing center could achieve a throughput of 2.5 persons per minute. Using computer modeling, we recommended changes to the dispensing plan that would enable it to achieve a higher throughput of four to five persons per minute. Other recommendations addressed improvements to dispensing plans and procedures. [ABSTRACT FROM AUTHOR]

Highlights the number of residences in Washington, D.C. that have lead service pipes as of March 2004. Effects of lead exposure on children and adults; Percentage of households that used water filters; Cause of an increase in water lead levels.

Educators are responsible for supporting positive school experiences for all students, including those with or at risk for emotional and behavioral disorders (EBD). Students with or at risk for EBD experience multiple negative outcomes impacting their school years, and these negative outcomes extend past graduation. Social and emotional learning programs are being used by schools to build students' competency in areas designed to help them successfully manage the school environment and life in general. However, studies have not provided evidence that universal social-emotional learning (SEL) programs are effective for Black students. This study provides data on the efficacy of an intervention package comprised of the Strong Kids SEL Program and a Tier 2 culturally adapted check-in/check-out (CICO) with Black students in a rural district in an underserved community. Cultural adaptations presented for the SEL curriculum were based on developers' recommendations and teacher feedback from prior studies and incorporated focus groups. Behavior management support in the form of a culturally adapted CICO was provided to participants exhibiting externalizing behaviors disruptive to the learning process. Results indicated a functional relation between the intervention package culturally adapted (SEL + CICO) and a decrease in student rate of externalizing behavior and strong social validity across teachers and students. Hierarchical linear modeling showed a statistically significant decrease in externalizing behavior from baseline to intervention phases, with data suggesting the moderator of grade-level explained variability in the effectiveness of the intervention. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Background: Febrile infants aged 0 to 60 days are often hospitalized for a 36-to-48 hour observation period to rule out invasive bacterial infections (IBI). Evidence suggests that monitoring blood and cerebrospinal fluid (CSF) cultures for 24 hours may be appropriate for most infants. We aimed to decrease the average culture observation time (COT) from 38 to 30 hours among hospitalized infants 0 to 60 days old over 12 months., Methods: This quality improvement initiative occurred at a large children's hospital, in conjunction with development of a multidisciplinary evidence-based guideline for the management of febrile infants. We included infants aged 0 to 60 days admitted with fever without a clear infectious source. We excluded infants who had positive blood, urine, or CSF cultures within 24 hours of incubation and infants who were hospitalized for other indications (eg, bronchiolitis). Interventions included guideline dissemination, education regarding laboratory monitoring practices, standardized order sets, and near-time identification of failures. Our primary outcome was COT, defined as time between initiation of culture incubation and hospital discharge in hours. Interventions were tracked on an annotated statistical process control chart. Our balancing measure was identification of IBI after hospital discharge., Results: In our cohort of 184 infants aged 0 to 60 days, average COT decreased from 38 hours to 32 hours after structured guideline dissemination and order-set standardization; this decrease was sustained over 17 months. IBI was not identified in any patients after discharge., Conclusions: Implementation of an evidence-based guideline through education, transparency of laboratory procedures, creation of standardized order sets, and near-time feedback was associated with shorter COT for febrile infants aged 0 to 60 days.

Background: Group B Streptococcus (GBS) remains a significant cause of neonatal infection, but the maternal risk factors for GBS colonization remain poorly defined. We hypothesized that there may be an association between antibiotic exposure during pregnancy and GBS colonization and/or the presence of inducible clindamycin resistance (iCLI-R) in GBS isolates from GBS-colonized pregnant women., Methods: A retrospective cohort study was performed at Louisiana State University Health Sciences Center - Shreveport including demographic and clinical data from 1513 pregnant women who were screened for GBS between July 1, 2009 and December 31, 2010., Results: Among 526 (34.8%) women who screened positive for GBS, 124 (23.6%) carried GBS strains with iCLI-R (GBS-iCLI-R). While antibiotic exposure, race, sexually-transmitted infection (STI) in pregnancy, GBS colonization in prior pregnancy and BMI were identified as risk factors for GBS colonization in univariate analyses, the only independent risk factors for GBS colonization were African-American race (AOR = 2.142; 95% CI = 2.092-3.861) and STI during pregnancy (AOR = 1.309; 95% CI = 1.035-1.653). Independent risk factors for GBS-iCLI-R among women colonized with GBS were non-African-American race (AOR = 2.13; 95% CI = 1.20-3.78) and younger age (AOR = 0.94; 95% CI = 0.91-0.98). Among GBS-colonized women with an STI in the current pregnancy, the only independent risk factor for iCLI-R was Chlamydia trachomatis infection (AOR = 4.31; 95% CI = 1.78-10.41)., Conclusions: This study identified novel associations for GBS colonization and colonization with GBS-iCLI-R. Prospective studies will improve our understanding of the epidemiology of GBS colonization during pregnancy and the role of antibiotic exposure in alterations of the maternal microbiome.

Background: In experiments with Formosan subterranean termites (Coptotermes formosanus Shirakii), myo-inositol-2-monophosphate as the dicyclohexylammonium salt was tested among other sugar derivatives, and was found to be toxic to C. formosanus when added to a moistened filter paper food source in plastic Petri dishes., Results: Curiously, over a nine-day period, the moniliform (beaded) antenna of C. formosanus deteriorated in a stepwise fashion with the most distal pseudosegment (bead) turning brown and falling off, followed by the penultimate pseudosegment, sequentially, until 7-9 days when only a stub of the antenna remained. Termites became increasingly moribund with the loss of antennae, and quit normal behavior including consuming cellulose food, and died. sn-Glycerol-3-phosphate as the dicyclohexylammonium salt also gave the same results. Dicyclohexylammonium hydrogen phosphate and monocyclohexylammonium dihydrogen phosphate were synthesized, to find a low-cost form for application to baits, both of which also showed similar toxicity. In a trial with Fibonacci series dilutions of neat cyclohexylamine, the antenna-affecting activity became apparent in the LD 30 (14 days) to LD 70 range of concentrations. At the higher concentrations, darkening of the most distal parts of leg extremities was noticed., Conclusion: Cyclohexylamine appears to be a novel termiticide with a previously unreported mechanism of toxicity. Its hydrogen phosphate salts retain the toxic effect and are inexpensive and easily synthesized. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

Objective: In 2004, The American Chemistry Council Phosgene Panel established a phosgene exposure registry among US phosgene producers with the primary purpose of monitoring health outcome information for workers with acute exposure., Methods: We examine symptoms among 338 workers with phosgene exposure. The phosgene exposures averaged 8.3 ppm-minutes ranging up to 159 ppm-minutes with most exposures below 10 ppm-minutes., Results: We found that the level of phosgene exposure in ppm-minutes was related to workers reporting mostly irritation symptoms of the nose, throat and eyes within 48 hours of exposure. However, we found no relationship between phosgene exposure and the presence of symptoms 30 days after exposure., Conclusions: These findings lend credence to the theory that prolonged respiratory effects do not occur with doses less than 150 ppm-minutes.

Background: In 2003, residents of the District of Columbia (DC) experienced an abrupt rise in lead levels in drinking water, which followed a change in water-disinfection treatment in 2001 and which was attributed to consequent changes in water chemistry and corrosivity., Objectives: To evaluate the public health implications of the exceedance, the DC Department of Health expanded the scope of its monitoring programs for blood lead levels in children., Methods: From 3 February 2004 to 31 July 2004, 6,834 DC residents were screened to determine their blood lead levels., Results: Children from 6 months to 6 years of age constituted 2,342 of those tested; 65 had blood lead levels > 10 microg/dL (the "level of concern" defined by the Centers for Disease Control and Prevention), the highest with a level of 68 microg/dL. Investigation of their homes identified environmental sources of lead exposure other than tap water as the source, when the source was identified. Most of the children with elevated blood lead levels (n = 46; 70.8%) lived in homes without lead drinking-water service lines, which is the principal source of lead in drinking water in older cities. Although residents of houses with lead service lines had higher blood lead levels on average than those in houses that did not, this relationship is confounded. Older houses that retain lead service lines usually have not been rehabilitated and are more likely to be associated with other sources of exposure, particularly lead paint. None of 96 pregnant women tested showed blood lead levels > 10 microg/dL, but two nursing mothers had blood lead levels > 10 microg/dL. Among two data sets of 107 and 71 children for whom paired blood and water lead levels could be obtained, there was no correlation (r(2) = -0.03142 for the 107)., Conclusions: The expanded screening program developed in response to increased lead levels in water uncovered the true dimensions of a continuing problem with sources of lead in homes, specifically lead paint. This study cannot be used to correlate lead in drinking water with blood lead levels directly because it is based on an ecologic rather than individualized exposure assessment; the protocol for measuring lead was based on regulatory requirements rather than estimating individual intake; numerous interventions were introduced to mitigate the effect; exposure from drinking water is confounded with other sources of lead in older houses; and the period of potential exposure was limited and variable.

Several solid tumors have now been shown to contain stem cell-like cells called cancer stem cells (CSC). These cells, although generally rare, appear to be highly tumorigenic and may be the cells that drive tumor formation, maintain tumor homeostasis, and mediate tumor metastasis. In this Perspective, we first provide our insight on how a CSC should be defined. We then summarize our current knowledge of stem/progenitor cells in the normal human prostate (NHP), an organ highly susceptible to hyperproliferative diseases such as benign prostate hyperplasia (BPH) and prostate cancer (PCa). We further review the evidence that cultured PCa cells, xenograft prostate tumors, and patient tumors may contain stem/progenitor cells. Along with our discussion, we present several methodologies that can be potentially used to identify putative tumor-reinitiating CSC. Finally, we present a hypothetical model for the hierarchical organization of human PCa cells and discuss the implications of this model in helping understand prostate carcinogenesis and design novel diagnostic, prognostic, and therapeutic approaches., (Copyright 2006 Wiley-Liss, Inc.)

Recently, several human cancers including leukemia and breast and brain tumors were found to contain stem-like cancer cells called cancer stem cells (CSC). Most of these CSCs were identified using markers that identify putative normal stem cells. In some cases, stem-like cancer cells were identified using the flow cytometry-based side population technique. In this study, we first show that approximately 30% of cultured human cancer cells and xenograft tumors examined ( approximately 30 in total) possess a detectable side population. Purified side population cells from two cell lines (U373 glioma and MCF7 breast cancer) and a xenograft prostate tumor (LAPC-9) are more tumorigenic than the corresponding non-side population cells. These side population cells also possess some intrinsic stem cell properties as they generate non-side population cells in vivo, can be further transplanted, and preferentially express some "stemness" genes, including Notch-1 and beta-catenin. Because the side population phenotype is mainly mediated by ABCG2, an ATP-binding cassette half-transporter associated with multidrug resistance, we subsequently studied ABCG2+ and ABCG2- cancer cells with respect to their tumorigenicity in vivo. Although side population cells show increased ABCG2 mRNA expression relative to the non-side population cells and all cancer cells and xenograft tumors examined express ABCG2 in a small fraction (0.5-3%) of the cells, highly purified ABCG2+ cancer cells, surprisingly, have very similar tumorigenicity to the ABCG2- cancer cells. Mechanistic studies indicate that ABCG2 expression is associated with proliferation and ABCG2+ cancer cells can generate ABCG2- cells. However, ABCG2- cancer cells can also generate ABCG2+ cells. Furthermore, the ABCG2- cancer cells form more and larger clones in the long-term clonal analyses and the ABCG2- population preferentially expresses several "stemness" genes. Taken together, our results suggest that (a) the side population is enriched with tumorigenic stem-like cancer cells, (b) ABCG2 expression identifies mainly fast-cycling tumor progenitors, and (c) the ABCG2- population contains primitive stem-like cancer cells.

Since nitric oxide has a role in the refinement of the retinal projection to the superior colliculus (SC), we studied the onset of neuronal nitric oxide synthase (nNOS) expression in the mouse SC in order to compare its development with that of the refinement process. Sections from animals at ages P1, P5, P8, P11, P15, and P21 and adults were examined with nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry or immunocytochemistry using an antibody directed against nNOS. At all ages there was a wedge of labeled neurons in the dorsolateral periaqueductal gray extending into the deep layers of the SC. At P1 there was also a single superficial band of labeled neurons within the region that will become the intermediate gray layer (IGL). By P5, labeled neurons were also seen in what will become the superficial gray layer. There was a ventral to dorsal progression in nNOS expression with substantial changes in the numbers of labeled neurons in the different laminae between P5 and adulthood. The number of labeled neurons in the IGL peaked at P15, whereas in the superficial layers the numbers continued to increase through P21 and then declined in adults. At all ages these neurons represented a variety of morphological cell types. The onset of nNOS expression in the different laminae is earlier than has been reported in studies using NADPHd as a marker for nNOS. The temporal and spatial patterns of nNOS expression reported here match more closely the time course of pathway refinement in the SC, providing additional evidence for the involvement of nitric oxide in this process., (Copyright 2000 Wiley-Liss, Inc.)

The authors examined the influence of sociodemographic variables on the frequency and intensity of alcohol use among a nationally representative sample of Black, Hispanic, and White adolescents who had participated in the 1991 National Household Survey on Drug Abuse (U.S. Department of Health and Human Services, 1993). The sample consisted of 8,756 U.S. adolescents aged 12 to 18 years. The authors found that (a) approximately 19% of the respondents had used alcohol in the last 30 days: (b) among the respondents who had used alcohol, 21% had consumed 1 or more drinks per drinking episode; and (c) there were important similarities as well as important differences in variables that promoted alcohol use among Black. Hispanic, and White adolescents.

As physicians and other health-care providers are experiencing an increased number of lawsuits, external pressures also are being exerted by various third-party payers and peer review organizations. An overview of some of the problems that may arise and methods for responding is presented. Knowledge of the processes involved by peer groups will help in risk management concerns as well. A new approach to quality assurance by the federal government is also described, the Health Care Quality Improvement Initiative.

Coarctation of the abdominal aorta represents an unusual but surgically treatable form of hypertension. The cause is somewhat controversial but generally can be traced to congenital or acquired origins. A case is presented in which the anomaly appears to be congenital. The variability in anatomy and subsequent treatment are discussed along with appropriate evaluation of the problem.

Six patients who originally received radiotherapy for Hodgkin's disease or primary gastric lymphoma developed radiation injury of the stomach requiring surgical management. Only two of these patients had evidence of gastric neoplastic involvement at the time of treatment. Experience with these patients leads us to draw the following conclusions: (1) Symptoms of radiation injury mimic those of recurrent neoplastic disease. (2) The effects of radiation are progressive and may be resistant to medical management. (3) The indications for surgical management include perforation, hemorrhage, obstruction, intractable pain, fistula formation, and inability to rule out recurrence. (4) Parenteral hyperalimentation can be an important adjunct in preparing debilitated patients for operation. (5) Gastric resection with gastrojejunostomy is the preferred operation. (6) Frozen section examination can be useful in determining the proper level of resection.