Mapping the colorectal tumor microbiota

The gut microbiome in patients with colorectal cancer (CRC) is different than that of healthy controls. Previous studies have profiled the CRC tumor microbiome using a single biopsy. However, since the morphology and cellular subtype vary significantly within an individual tumor, the possibility of sampling error arises for the microbiome within an individual tumor. To test this hypothesis, seven biopsies were taken from representative areas on and off the tumor in five patients with CRC. The microbiome composition was strikingly similar across all samples from an individual. The variation in microbiome alpha-diversity was significantly greater between individuals' samples then within individuals. This is the first study, to our knowledge, that shows that the microbiome of an individual tumor is spatially homogeneous. Our finding strengthens the assumption that a single biopsy is representative of the entire tumor, and that microbiota changes are not limited to a specific area of the neoplasm.

Effects of lymphatic drainage and local cryo exposition regeneration after high-intensive exercises

BACKGROUND

Recovery from exercise and competition is important in sports medicine, particularly when rest periods are short. The objective is to determine the efficacy of cryo exposition (CRY) and manual lymphatic drainage (MLD) to hasten short term recovery of muscle performance after eccentric contractions.

METHODS

In a randomized controlled trial, 30 healthy sport students (21 males, 9 females; age: 25.7±2.8 years) performed 4×20 eccentric contractions of knee extensors, followed by 30 min MLD, CRY, or rest (RST) under controlled laboratory environment. Maximal voluntary contractions (MVC), electrically induced muscle fatigue (FI), and electrically induced tetani (EIT) at low (T2: 20 Hz) and high frequencies were tested.

RESULTS

Force decline and recovery kinetics regarding MVC, FI, and EIT did not differ significantly (p<0.05) between groups. That is, 24 h after the intervention, MVC (MLD: 80.9±5.5%; CRY: 81.1±8.5%; RST: 83.5±7.3%), FI (MLD: 83.2±23.7%; CRY: 81.2±38.8%; RST: 93.2±22.9%), and EIT (T1: MLD: 53.0±29.5%; CRY: 39.0±32.9%; RST: 46.3±26.1%; T2: MLD: 84.2±27.2%; CRY: 64.2±24.2%; RST: 66.6±22.3%) were similarly depressed irrespective of applied treatments.

CONCLUSION

Neither CRY nor MLD hastened the recovery of muscle performance, when applied for 30 min. Identification number of the Primary Registry Network: DRKS00007608.

Effects of stimulation frequency, amplitude, and impulse width on muscle fatigue

INTRODUCTION

We investigated the effect of stimulation intensity (in percent of maximal tolerated stimulation current, mTSC), frequency, and impulse width on muscle fatigue.

METHODS

Using a randomized crossover design, 6 parameter combinations (80% mTSC, 80 Hz, 400 μs; 60% mTSC, 80 Hz, 400 μs; 80% mTSC, 20 Hz, 400 μs; 60% mTSC, 20 Hz, 400 μs; 80% mTSC, 80 Hz, 150 μs; 60% mTSC, 80 Hz, 150 μs) were tested in both legs of 13 athletic men (age 26 ± 2.3). The slope of the linear regression line over all tetani (FIS) and the number of tetani whose force was above 50% of the initial tetanus (FIN) were used to quantify fatigue.

RESULTS

FIS and FIN were significantly lower in high-frequency protocols. No effects on FIS and FIN were found for intensity and impulse width.

CONCLUSIONS

Stimulation frequency, but not impulse width or intensity, affected fatigue kinetics.

Serum Cartilage Oligomeric Matrix Protein: is There a Repeated Bout Effect?

The primary aim of the present study was to investigate if there is a repeated bout effect for cartilage tissue, evident in the marker serum cartilage oligomeric matrix protein (sCOMP). Ten healthy male subjects (26.4±3.14 years) performed two high impact interventions (100 drop jumps with a 30 second interval) carried out at a 3 week interval. After each intervention, sCOMP and muscle soreness were assessed on 8 and 6 occasions respectively. Muscle soreness was determined via a visual analog scale with a maximum pain score of 10. sComp levels did not show a blunted response after the second bout (Bout 1: 12.2±3.3 U/L⁻¹; Bout 2: 13.1±4.0 U/L⁻¹; P>0.05). Remarkably, sCOMP increased from baseline levels by 16% after bout 1 and 15% after bout 2. Muscle soreness was blunted following the second intervention (Bout 1: 5.0±1.8; Bout 2: 1.6±0.8). Unlike the known repeated bout effect for muscle damage markers, sCOMP levels do not show a blunted response after two similar loading interventions. This information on biomarker behavior is essential to clinicians attempting to use this marker as an indicator of cartilage damage associated with the development or progression of osteoarthritis.

Preclinical characterisation of the GM-CSF receptor as a therapeutic target in rheumatoid arthritis

Objective

Previous work has suggested that the granulocyte macrophage colony stimulating factor (GM-CSF)–GM-CSF receptor α axis (GM-CSFRα) may provide a new therapeutic target for the treatment of rheumatoid arthritis (RA). Therefore, we investigated the cellular expression of GM-CSFRα in RA synovial tissue and investigated the effects of anti-GM-CSFRα antibody treatment in vitro and in vivo in a preclinical model of RA.

Methods

We compared GM-CSFRα expression on macrophages positive for CD68 or CD163 on synovial biopsy samples from patients with RA or psoriatic arthritis (PsA) to disease controls. In addition, we studied the effects of CAM-3003, an anti-GM-CSFR antibody in a collagen induced arthritis model of RA in DBA/1 mice. The pharmacokinetic profile of CAM-3003 was studied in naïve CD1(ICR) mice (see online supplement) and used to interpret the results of the pharmacodynamic studies in BALB/c mice.

Results

GM-CSFRα was expressed by CD68 positive and CD163 positive macrophages in the synovium, and there was a significant increase in GM-CSFRα positive cells in patients in patients with RA as well as patients with PsA compared with patients with osteoarthritis and healthy controls. In the collagen induced arthritis model there was a dose dependent reduction of clinical arthritis scores and the number of F4/80 positive macrophages in the inflamed synovium after CAM-3003 treatment. In BALB/c mice CAM-3003 inhibited recombinant GM-CSF mediated margination of peripheral blood monocytes and neutrophils.

Conclusions

The findings support the ongoing development of therapies aimed at interfering with GM-CSF or its receptor in various forms of arthritis, such as RA and PsA.

Protein engineering and preclinical development of a GM-CSF receptor antibody for the treatment of rheumatoid arthritis

BACKGROUND AND PURPOSE

For antibody therapies against receptor targets, in vivo outcomes can be difficult to predict because of target-mediated clearance or antigen 'sink' effects. The purpose of this work was to engineer an antibody to the GM-CSF receptor α (GM-CSFRα) with pharmacological properties optimized for chronic, s.c. treatment of rheumatoid arthritis (RA) patients.

EXPERIMENTAL APPROACH

We used an in silico model of receptor occupancy to guide the target affinity and a combinatorial phage display approach for affinity maturation. Mechanism of action and internalization assays were performed on the optimized antibody in vitro before refining the modelling predictions of the eventual dosing in man. Finally, in vivo pharmacology studies in cynomolgus monkeys were carried out to inform the predictions and support future clinical development.

KEY RESULTS

Antibody potency was improved 8600-fold, and the target affinity was reached. The refined model predicted pharmacodynamic effects at doses as low as 1 mg kg(-1) and a study in cynomolgus monkeys confirmed in vivo efficacy at 1 mg kg(-1) dosing.

CONCLUSIONS AND IMPLICATIONS

This rational approach to antibody drug discovery enabled the isolation of a potent molecule compatible with chronic, s.c. self-administration by RA patients. We believe this general approach enables the development of optimal biopharmaceuticals.

Effects of weight-bearing activities on bone mineral content and density in children and adolescents: a meta-analysis

Osteoporosis and associated fractures are a major health concern in Western industrialized nations. Exercise during growth is suggested to oppose the involutional bone loss later in life by increasing peak bone mass. The primary aim of the present meta-analysis was to provide a robust estimate of the effect of weight-bearing activities (WBAs) on bone mineral content (BMC) and areal bone mineral density (aBMD), during childhood and adolescence. To locate relevant studies up to June 2012, computerized searches of multiple bibliographic databases and hand searches of key journals and reference lists were performed. Results were extracted by two independent reviewers. The quality of the included trials was assessed via the Physiotherapy Evidence Database (PEDro) score. The study group effect was defined as the difference between the standardized mean change for the treatment and control groups divided by the pooled pretest SD. From 109 potentially relevant studies, only 27 met the inclusion criteria. The analyzed training programs were capable of significantly increasing BMC and aBMD during growth. However, the weighted overall effect sizes (ESs) for changes in BMC (ES 0.17; 95% confidence interval [CI], 0.05-0.29; p < 0.05) and aBMD (ES 0.26; 95% CI, 0.02-0.49) were small. Stepwise backward regression revealed that more than one-third of the observed variance (r(2)  = 0.35) between subgroups of the BMC dataset could be explained by differences in the amount of habitual calcium intake per day (beta 0.54, p < 0.01) and the maturational stage (beta -0.28, p < 0.01) at baseline. No significant moderators were identified for aBMD, possibly due to the small number of trials investigating WBAs on aBMD. The results of this meta-analysis conclude that WBAs alongside high calcium intake provide a practical, relevant method to significantly improve BMC in prepubertal children, justifying the application of this exercise form as an osteoporosis prophylaxis in this stage of maturity.

Changes in outcome and management of perforated diverticulitis over a 10 year period

INTRODUCTION

Aggressive non-operative intervention and evolving surgical strategies have altered the treatment of perforated diverticulitis in the acute setting. These strategies have predominantly been implemented over the last decade. The aim of this study was to assess the impact of this on patient outcome during their index admission and subsequently.

METHODS

Consecutive patients admitted with acute diverticulitis between 1999 and 2010 were identified. Patient demographics, treatment strategies and outcomes were collected and analysed. Patients who had an episode of perforated diverticulitis during their index admission were followed.

RESULTS

739 patients were admitted with acute diverticulitis. Of these, 115 (15.7%) had perforated diverticulitis. 53 (47.8%) underwent an intervention. There was a reduction in the mean age of patients admitted with acute diverticulitis of 8.9% over the study period (p = 0.002). There was a significant increase in the use of CT scanning pre-operatively (p < 0.001). 'Non-resectional' interventions have emerged in the form of laparoscopic lavage (n = 5) and percutaneous abscess drainage (n = 14). There was associated improved length of stay (p < 0.001).

CONCLUSION

Outcomes for patients with perforated diverticulitis have improved, contributed to in part by an increased use of non-resectional management strategies.

An unusual presentation of Fournier's gangrene

INTRODUCTION

Fournier's gangrene is a rare severe necrotising fasciitis of the genitalia.

CASE

A case of Fournier's gangrene caused by perforated sigmoid diverticulitis in a patient with systemic lupus erythematosus is presented along with a review of the relevant literature.

Rectal cancer

Surgery is the cornerstone of rectal cancer treatment. Oncological cure and overall survival continue to be the main goals, but sparing of the anal sphincter mechanism and functional results are also important. The modern management of rectal cancer is a multidisciplinary approach, and pre-operative staging is of crucial importance when planning treatment in these patients. Pre-operative staging is used to determine the indication for neoadjuvant therapy prior to surgical resection or to determine whether local excision is an option in carefully selected patients with early rectal cancer. Surgery in the form of total mesorectal excision (TME) has become the standard of care for mid and distal rectal cancers. Early rectal cancers do not require neoadjuvant therapy. For locally advanced cancers of the lower two-thirds of the rectum, the combination of surgical resection with chemoradiotherapy decreases local recurrence rates and probably improves overall survival. Whereas in the past local excision was only contemplated in patients who were unfit for radical surgery or for local palliation in cases of metastatic disease, over the last number of years there has been increasing interest in local treatment with curative intent in early rectal cancer.

Dopamine attenuates neutrophil–endothelial interaction and is a putative anti-inflammatory cytokine

Background

Activated neutrophil (PMN) adherence to vascular endothelium comprises a key step for both transendothelial migration and initiation of potentially deleterious release of PMN products. Previous work has shown that the biogenic amine dopamine (DA) functions as an anti-inflammatory cytokine by inducing PMN apoptosis. The effect of DA on PMN transendothelial migration and adhesion receptor expression as well as on the endothelial molecules, E-selectin and intercellular adhesion molecule (ICAM) 1, was evaluated.

Methods

PMNs were isolated from healthy controls, stimulated with lipopolysaccharide (LPS) and tumour necrosis factor (TNF) α and treated with DA. CD11b and CD18 PMN adhesion receptor expression was assessed flow cytometrically. In a separate transwell experiment, the effect of the chemo-attractant peptide interleukin (IL) 8 on PMN migration was assessed. Human umbilical vein endothelial cells were stimulated with LPS/TNF-α, incubated with DA, and ICAM-1 and E-selectin endothelial molecule expression was assessed.

Results

There was a significant increase in transendothelial migration in stimulated PMNs as well as in CD11b/CD18, endothelial E-selectin and ICAM-1 expression compared with normal PMNs. DA attenuated these changes. The chemoattractant effect of IL-8 was also abolished.

Conclusion

These results show that DA attenuates the initial interaction between PMNs and endothelium, providing further evidence that it also functions as an anti-inflammatory cytokine.

A molecular orbital study of a model of the Mg2+ coordination complex of the self splicing reaction of ribosomal RNA

Recent discoveries have established the fact that RNA is capable of acting as an enzyme. In this study two different types of molecular orbital calculations, INDO and ab initio, were used in an attempt to assess the structural/functional role of the Mg2+ hydrated complex in ribozyme reactions. Preliminary studies indicate that the reaction is multistep and that the Mg2+ complex exerts a stabilizing effect on the intermediate or midpoint of the reaction.

Activated human neutrophils release hepatocyte growth factor/scatter factor

BACKGROUND

Hepatocyte growth factor or scatter factor (HGF/SF) is a pleiotropic cytokine that has potent angiogenic properties. We have previously demonstrated that neutrophils (PMN) are directly angiogenic by releasing vascular endothelial growth factor (VEGF). We hypothesized that the acute inflammatory response can stimulate PMN to release HGF.

AIMS

To examine the effects of inflammatory mediators on PMN HGF release and the effect of recombinant human HGF (rhHGF) on PMN adhesion receptor expression and PMN VEGF release.

METHODS

In the first experiment, PMN were isolated from healthy volunteers and stimulated with tumour necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), interleukin-8 (IL-8), and formyl methionyl-leucyl-phenylalanine (fMLP). Culture supernatants were assayed for HGF using ELISA. In the second experiment, PMN were lysed to measure total HGF release and HGF expression in the PMN was detected by Western immunoblotting. Finally, PMN were stimulated with rhHGF. PMN CD 11a, CD 11b, and CD 18 receptor expression and VEGF release was measured using flow cytometry and ELISA respectively.

RESULTS

TNF-alpha, LPS and fMLP stimulation resulted in significantly increased release of PMN HGF (755+/-216, 484+/-221 and 565+/-278 pg/ml, respectively) compared to controls (118+/-42 pg/ml). IL-8 had no effect. Total HGF release following cell lysis and Western blot suggests that HGF is released from intracellular stores. Recombinant human HGF did not alter PMN adhesion receptor expression and had no effect on PMN VEGF release.

CONCLUSIONS

This study demonstrates that pro-inflammatory mediators can stimulate HGF release from a PMN intracellular store and that activated PMN in addition to secreting VEGF have further angiogenic potential by releasing HGF.

Taurolidine inhibits tumor cell growth in vitro and in vivo

BACKGROUND

Taurolidine, a derivative of the amino acid taurine, exhibits antiendotoxin, antibacterial, and antiadherence activity. We hypothesized that Taurolidine may inhibit tumor cell growth, both in an in vitro and in vivo setting. Our aim was to examine the effect of Taurolidine on the growth of a rat metastatic colorectal tumor cell line (DHD/K12/TRb) in vitro and in vivo.

METHODS

In the in vitro experiments, DHD/K12/TRb cells were incubated with 5, 10, 15, 25, microg/ml of Taurolidine. Cells incubated in culture medium alone were used as controls. Cell proliferation, cell viability, cell death, and cell apoptosis were measured using commercially available techniques. In the in vivo experiment, BD IX rats were randomized into two groups (n = 10/group). Group A (control) underwent laparotomy and instillation of DHD/K12/TRb tumor cells intraperitoneally followed by phosphate buffered saline (PBS). Group B received Taurolidine (100 mg/kg) instead of PBS. Animals were killed after 24 days and tumor burden assessed by counting the number of tumor nodules in the peritoneal cavity.

RESULTS

Incubation of the tumor cells with Taurolidine resulted in a 4-fold decrease in proliferation rates (25+/-4% vs. 100+/-28% for controls) and a 4-fold increase in cell necrosis as demonstrated by the increase in LDH release (403+/-28% vs. 100+/-26% for controls), at a Taurolidine concentration of 25 microg/ml. A dose-dependent decrease in cell viability was also observed. In the in vivo study, local Taurolidine administration resulted in significant decreases in tumor burden (3+/-1 nodules in Group B animals vs. 649+/-101 nodules in Group A animals).

CONCLUSIONS

Taurolidine inhibits the growth of a rat metastatic colorectal tumor cell line in vitro and in vivo and thus may have potential in the prevention of peritoneal metastases.

Proinflammatory mediators stimulate neutrophil-directed angiogenesis

BACKGROUND

Vascular endothelial growth factor (VEGF; vascular permeability factor) is one of the most potent proangiogenic cytokines, and it plays a central role in mediating the process of angiogenesis or new blood vessel formation. Neutrophils (PMNs) recently have been shown to produce VEGF.

HYPOTHESIS

The acute inflammatory response is a potent stimulus for PMN-directed angiogenesis.

METHODS

Neutrophils were isolated from healthy volunteers and stimulated with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and anti-human Fas monoclonal antibody. Culture supernatants were assayed for VEGF using enzyme-linked immunosorbent assays. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs were then added to human umbilical vein endothelial cells and human microvessel endothelial cells and assessed for endothelial cell proliferation using 5-bromodeoxyuridine labeling. Tubule formation was also assessed on MATRIGEL basement membrane matrix. Neutrophils were lysed to measure total VEGF release, and VEGF expression was detected using Western blot analysis.

RESULTS

Lipopolysaccharide and TNF-alpha stimulation resulted in significantly increased release of PMN VEGF (532+/-49 and 484+/-80 pg/mL, respectively; for all, presented as mean +/- SEM) compared with control experiments (32+/-4 pg/mL). Interleukin 6 and Fas had no effect. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs also resulted in significant increases (P<.005) in macrovascular and microvascular endothelial cell proliferation and tubule formation. Adding anti-human VEGF-neutralizing polyclonal antibody to stimulated PMN supernatant inhibited these effects. Total VEGF release following cell lysis and Western blot analysis suggests that the VEGF is released from an intracellular store.

CONCLUSION

Activated human PMNs are directly angiogenic by releasing VEGF, and this has important implications for inflammation, capillary leak syndrome, wound healing, and tumor growth.

Dopamine induces neutrophil apoptosis through a dopamine D-1 receptor-independent mechanism

BACKGROUND

For the normal resolution of an acute inflammatory response, neutrophil (PMN) apoptosis is essential to maintain immune homeostasis and to limit inappropriate host tissue damage. A delay in PMN apoptosis has been implicated in the pathogenesis of the systemic inflammatory response syndrome (SIRS). Dopamine, a biogenic amine with known cardiovascular and neurotransmitter properties, is used in patients with SIRS to maintain hemodynamic stability. We sought to determine whether dopamine may also have immunoregulatory properties capable of influencing PMN apoptosis, function, and activation state in patients with SIRS.

METHODS

PMNs were isolated from healthy volunteers and patients with SIRS and treated with varying doses of dopamine and a dopamine D-1 receptor agonist, fenoldopam. PMN apoptosis was assessed every 6 hours with use of propidium iodide DNA staining and PMN function was assessed with use of respiratory burst activity, phagocytosis ability, and CD11a, CD11b, and CD18 receptor expression as functional markers.

RESULTS

There was a significant delay in PMN apotosis in patients with SIRS compared with controls. Treatment of isolated PMNs from both healthy controls and patients with SIRS with 10 and 100 mumol/L dopamine induced apoptosis. PMN ingestive and cytocidal capacity were both decreased in patients with SIRS compared with controls. Treatment with dopamine significantly increased phagocytic function. Fenoldopam did not induce PMN apoptosis.

CONCLUSION

Our data demonstrate for the first time that dopamine induces PMN apoptosis and modulates PMN function both in healthy controls and in patients with SIRS. These results indicate that dopamine may be beneficial during SIRS through a nonhemodynamic PMN-dependent proapoptotic mechanism.

Responsibilities, roles & staffing patterns of nurse practitioners in the neonatal intensive care unit

PURPOSE

To describe the unique contribution of the NP in caring for critically ill infants through the study of NP responsibilities, roles, staffing patterns, and patient profiles.

DESIGN

This prospective descriptive study was conducted in conjunction with a regional multi-site outcomes study.

METHODS

Data were collected at five regional level II/III NICUs in Massachusetts and Rhode Island. Twenty-two NPs were surveyed. Existing data on outcomes of 2,146 very low birth weight infants were used to describe patient profiles. NP care was defined as assignment to an NP at admission. Illness severity was measured using the Score of Neonatal Acute Physiology (SNAP).

RESULTS

NP roles included all levels of NICU care as well as antepartal consultation, delivery room management, transport, and outpatient follow-up. NPs were equally involved with patients of all degrees of complexity and birthweights. Patient assignments were most often made by a rotational system with the resident/fellow or by complexity of infant with the NP in some NICUs caring for sicker smaller babies.

CLINICAL IMPLICATIONS

This study documents a blended model of NP MD care in the NICU with each provider bringing unique strengths to the team. Nurse practitioners working in the NICU provide an invaluable contribution in terms of parent support and teaching, post NICU follow-up care, and professional education and research. The NP role in the NICU should not be viewed as a substitution for resident physicians.

Preclinical and clinical studies of MMP inhibitors in cancer

The role of matrix metalloproteinases in tumor angiogenesis and growth is now well recognized for models of both human and animal cancer. Clinical studies currently under way with the prototype matrix metalloproteinase inhibitor, marimastat, will establish whether inhibitors of these enzymes are of benefit in the treatment of different types of human cancer. On chronic therapy in humans, marimastat induces a reversible tendinitis that can also be detected in certain animal species. This paper compares the ability of broad-spectrum and various types of selective matrix metalloproteinase inhibitors to induce tendinitis and to exhibit anticancer effects in an animal cancer model. Under conditions in which both systemic exposure and inhibitor potency are controlled, selective inhibitors are less pro-tendinitic, but are weaker anticancer agents than broad-spectrum agents such as marimastat. The clinical relevance of these findings is discussed.

Acute renal failure in the newborn

Newborns at risk for acute renal failure require immediate diagnosis and treatment. Supportive care must be provided while the kidney heals and begins functioning again. The critical care nurse plays a vital role in early recognition and treatment of signs and symptoms of acute renal failure. As technology improves, a greater number of acutely ill newborns are surviving. The critical care nurse is managing more neonates with acute renal failure. Expertise in caring for these infants has also improved. Quality nursing care plays a crucial role in preventing complications and improving the prognosis of neonates with renal failure.

Acute renal failure in the newborn

Newborns at risk for acute renal failure require immediate diagnosis and treatment. Supportive care must be provided while the kidney heals and begins functioning again. The critical care nurse plays a vital role in early recognition and treatment of signs and symptoms of acute renal failure. As technology improves, a greater number of acutely ill newborns are surviving. The critical care nurse is managing more neonates with acute renal failure. Expertise in caring for these infants has also improved. Quality nursing care plays a crucial role in preventing complications and improving the prognosis of neonates with renal failure.

BB-10010: an active variant of human macrophage inflammatory protein-1 alpha with improved pharmaceutical properties

The stem cell inhibitor, macrophage inflammatory protein-1 alpha (MIP-1 alpha) or LD78, protects multipotent hematopoietic progenitors in murine models from the cytotoxic effects of chemotherapy. Clinical use of human MIP-1 alpha during chemotherapy could therefore lead to faster hematologic recovery and may allow dose intensification. We have also shown that human MIP-1 alpha causes the rapid mobilization of hematopoietic cells, suggesting an additional clinical use in peripheral blood stem cell transplantation. However, the clinical evaluation of human MIP-1 alpha is complicated by its tendency to associate and form high molecular weight polymers. We have produced a variant of rhMIP-1 alpha, BB-10010, carrying a single amino acid substitution of Asp26 > Ala, with a reduced tendency to form large polymers at physiologic pH and ionic strength. This greatly increases its solubility, facilitating its production and clinical formulation. We confirmed the potency of BB-10010 as a human MIP-1 alpha-like agonist in receptor binding, calcium mobilization, inhibition of colony formation, and thymidine suicide assays. The myeloprotective activity of BB-10010 was shown in a murine model of repeated chemotherapy using hydroxyurea. BB-10010 is therefore an ideal variant with which to evaluate the therapeutic potential of recombinant human MIP-1 alpha.

Mobilization of early hematopoietic progenitor cells with BB-10010: a genetically engineered variant of human macrophage inflammatory protein-1 alpha

BB-10010 is a genetically engineered variant of human macrophage inflammatory protein-1 alpha with improved solution properties. We show here that it mobilizes stem cells into the peripheral blood. We investigated the mobilizing effects of BB-10010 on the numbers of circulating 8-day spleen colony-forming units (CFU-S8), CFU-S12, and progenitors with marrow repopulating ability (MRA). A single subcutaneous dose of BB-10010 caused a twofold increase in circulating numbers of CFU-S8, CFU-S12, and MRA 30 minutes after dosing. We also investigated the effects of granulocyte colony-stimulating factor (G-CSF) and the combination of G-CSF with BB-10010 on progenitor mobilization. Two days of G-CSF treatment increased circulating CFU-S8, CFU-S12, and MRA progenitors by 25.7-, 19.8-, and 27.7-fold. A single administration of BB-10010 after 2 days of G-CSF treatment increased circulating CFU-S8, CFU-S12, and MRA even further to 38-, 33-, and 100-fold. Splenectomy resulted in increased circulating progenitor numbers but did not change the pattern of mobilization. Two days of treatment with G-CSF then increased circulating CFU-S8, CFU-S12, and MRA by 64-, 69-, and 32-fold. A single BB-10010 administration after G-CSF treatment further increased them to 85-, 117-, and 140-fold, respectively, compared with control. We conclude that BB-10010 causes a rapid increase in the number of circulating hematopoietic progenitors and further enhances the numbers induced by pretreatment with G-CSF. BB-10010 preferentially mobilized the more primitive progenitors with marrow repopulating activity, releasing four times the number achieved with G-CSF alone. Translated into a clinical setting, this improvement in progenitor cell mobilization may enhance the efficiency of harvest and the quality of grafts for peripheral blood stem cell transplantation.

Grating induction: a new explanation for stationary phantom gratings

The magnitude of brightness variations within test fields of grating induction and phantom grating type displays was measured using a pointwise brightness matching paradigm. A range of test field luminances was sampled which encompassed those reported to give rise to both in-phase phantom and counterphase induced gratings. Results from four observers failed to reveal the existence of stationary "in phase" phantom gratings: at all test field luminances the spatial phase of brightness modulations was consistently opposite to that of the inducing grating. At low or high test field luminances, however, test field luminance matches to the bright or dark half-cycles of induced gratings approximate the luminances of the troughs or peaks of the dark or bright half-cycles of the inducing gratings, respectively. Thus, at low test field luminances the dark half-cycle of the inducing grating may appear to continue across the dark test field, and similarly, at high test field luminances the bright half-cycle may appear continuous with the bright test field. Previously misidentified as being "in-phase" with the inducing grating, the appearance of "phantoms" is suggested to arise due to the apparent brightness continuity of these induction-produced half-cycles of the induced grating across the test field.

At risk for infection: the very-low-birth-weight infant

The very-low-birth-weight (VLBW) infant is at high risk for developing infection during the antenatal, prenatal, and postnatal periods. The six major predisposing factors are perinatal infections, an immature immune system, decreased natural defenses, disease states and disorders leading to infection, side effects of medication, and prolonged hospitalization and iatrogenic complications of lifesaving therapies. Quality nursing care plays a crucial role in recognizing signs and symptoms of sepsis and facilitating a timely diagnostic evaluation. Prevention, prompt diagnosis, and treatment will reduce the high morbidity and mortality rates associated with sepsis in the VLBW infant.

Computer-assisted molecular modeling of benzodiazepine and thyromimetic inhibitors of the HepG2 iodothyronine membrane transporter

T3 cellular uptake is inhibited in the presence of benzodiazepines (BZs). The structure-activity relationship of BZ inhibition correlates strongly with halogen substitution of the nonfused phenyl ring and indicates that this ring is required for activity. A structure-activity series of thyromimetic (TH) inhibitors of the HepG2 iodothyronine transporter further point out the critical importance of the amino group of the alanine side chain, its L-stereo configuration, and the size of the substituents of the inner and outer phenyl rings. A third series of compounds, reported to interact at related sites, were inactive as HepG2 iodothyronine transport inhibitors, and therefore the potent inhibitors were restricted to the BZ and TH compounds. Using both of these BZ and TH structure-activity series along with computer-assisted molecular modeling techniques, we determined which chemical structural components were important at the transporter interaction site. By superimposing structures from active chemicals, excluding residues from poor inhibitors, and incorporating molecular electropotential data, we developed a five-point model of BZ conformational similarity to the endogenous transporter ligand, L-T3: the alkyl substitution at the N1 of the BZ ring seems to simulate the alanine side chain of T3, and the electro-negative halogen and oxygen atoms of substituents at R3/R7/R2'/R4' of BZ form a pyramidal pharmacophore that seems to correspond with the 3-l/5-l/3'-l/4'-OH substituents of T3, respectively. These points, suggesting a tilted cross-bow formation, may be sites for ligand interaction with the iodothyronine transporter.