An association study of 43 SNPs in 16 candidate genes with atorvastatin response

Variation in individual response to statin therapy has been widely studied for a potential genetic component. Multiple genes have been identified as potential modulators of statin response, but few study findings have replicated. To further examine these associations, 2735 individuals on statin therapy, half on atorvastatin and the other half divided among fluvastatin, lovastatin, pravastatin and simvastatin were genotyped for 43 SNPs in 16 genes that have been implicated in statin response. Associations with low-density lipoprotein cholesterol (LDL-C) lowering, total cholesterol lowering, HDL-C elevation and triglyceride lowering were examined. The only significant associations with LDL-C lowering were found with apoE2 in which carriers of the rare allele who took atorvastatin lowered their LDL-C by 3.5% more than those homozygous for the common allele and with rs2032582 (S893A in ABCB1) in which the two groups of homozygotes differed by 3% in LDL-C lowering. These genetic effects were smaller than those observed with the demographic variables of age and gender. The magnitude of all the differences found is sufficiently small that genetic data from these genes should not influence clinical decisions on statin administration.

Targeting the cytotoxicity of fusogenic membrane glycoproteins in gliomas through protease-substrate interaction

Fusogenic membrane glycoproteins (FMG) are potent therapeutic transgenes with potential utility in the gene therapy of gliomas. FMG expression constructs caused massive syncytia formation followed by cytotoxic cell death in glioma cell lines, and antitumor activity has been shown in glioma xenografts. FMG-induced fusion in glioma cells can involve heterologous cell lines including normal astrocytes and fibroblasts, therefore making targeting important. Here we report on the use of matrix metalloproteinase (MMP) cleavable linkers to target cytotoxicity of FMGs against gliomas. Expression constructs were made expressing the hyperfusogenic version of the Gibbon Ape Leukemia Virus envelope glycoprotein (GALV) linked to a blocking ligand (the C-terminal extracellular domain of CD40 ligand) via either an MMP cleavable linker (GALV M40), a factor Xa protease cleavable linker (GALV X40), or a noncleavable linker (GALV N40). Unmodified GALV expressing constructs were used as positive controls. The glioma cell lines U87, U118, and U251 previously characterized by zymography and MMP-2 activity assay as high, medium, and low MMP expressors, respectively; normal human astrocytes and the MMP-poor cell line TE671 were transfected with the GALV, GALV N40, GALV X40, and GALV M40 constructs. In contrast to unmodified GALV constructs, transfection with GALV X40 and GALV N40 constructs blocked fusion and cytotoxic cell death. Fusion occurred, however, after transfection with constructs containing MMP cleavable linkers to an extent dependent on MMP expression in the specific cell line. Use of the broad-spectrum MMP inhibitors, 1,10-phenanthroline and N-hydroxy-piperazine-carboxamide completely abolished the ability of MMP constructs to induce fusion. In cell mixing experiments, mixing of MMP-poor cell lines transfected with GALV M40 constructs with the MMP overexpressing untransfected U87 glioma cells led to partial restoration of fusion. Use of U87 supernatant did result in a similar effect. Establishment of stable tranfectants expressing the membrane-type MMPs, MT-1 MMP and MT-2 MMP did restore fusion in the MMP-poor cell line TE671 after transfection with GALV M40, thus indicating that both membrane-type MMPs and soluble MMPs activate the MMP cleavable constructs. In addition, the GALV M40 construct retained its cytotoxic activity against U87 cells in vivo, although less effectively as compared to unmodified GALV. Our data indicate that GALV-induced cytotoxicity in glioma cell lines can be blocked by display of the CD40 ligand. Incorporation of an MMP cleavable linker can selectively restore cytotoxicity in MMP expressing glioma cell lines both in vitro and in vivo, while sparing normal human astrocytes. Given the high frequency of MMP overexpression in gliomas, this represents a promising targeting strategy.

Imaging of congenital cystic lung lesions

Congenital cystic lung lesions are a rare but clinically significant group of anomalies, including congenital cystic adenomatoid malformation (CCAM), pulmonary sequestration, congenital lobar emphysema (CLE) and bronchogenic cysts. These conditions can all present on imaging studies as air or fluid filled cysts. Widespread use of antenatal ultrasound has led to increased detection of infants with congenital thoracic abnormalities in utero, resulting in a better understanding of the natural history of many of these lesions and also allowing provision to be made for delivery and postnatal management. More recently antenatal magnetic resonance (MR) imaging has provided further information on the nature of many of these lesions and helped to differentiate them from extrathoracic abnormalities such as congenital diaphragmatic hernia (CDH), which is important in parental counselling. Many children with congenital cystic lung lesions will present with symptoms resulting in the need for prompt diagnosis and treatment and imaging has an essential role in the management of these children. Some congenital lung lesions are treated surgically, whilst others are managed conservatively.

A novel technique for the identification of CpG islands exhibiting altered methylation patterns (ICEAMP)

Aberrant CpG methylation changes occurring during tumour progression include the loss (hypomethylation) and gain (hypermethylation) of methyl groups. Techniques currently available for examining such changes either require selection of a region, then examination of methylation changes, or utilise methylation-sensitive restriction enzymes to identify an alteration. We describe here a novel method that identifies genomic regions as a consequence of altered methylation during tumourigenesis. A methyl-CpG binding domain column isolates methylated GC-rich sequences from both tumours and surrounding normal tissue. Subsequent subtractive hybridisation removes sequences common to both, leaving only methylated sequences unique to the tumour. Libraries of sequences generated using DNA derived from a breast tumour (histological grade; poorly differentiated) as 'tester' and from matched normal tissue as 'driver' were examined; 26% of clones had the sequence criteria of a CpG island (CGI). Analysis using the bisulfite technique revealed that a number of these sequences were methylated in tumour DNA relative to the normal control. We have therefore demonstrated the ability of this technique, the identification of CGI exhibiting altered methylation patterns (ICEAMP), to isolate tumour-specific methylated GC-rich sequences. This will allow a comprehensive identification of methylation changes during tumourigenesis and will lead to a better understanding of the processes involved.

Two-dimensional gas chromatography and trilinear partial least squares for the quantitative analysis of aromatic and naphthene content in naphtha

Quantitative analysis of naphtha samples is demonstrated using comprehensive two-dimensional gas chromatography (GC x GC) and chemometrics. This work is aimed at providing a GC system for the quantitative and qualitative analysis of complex process streams for process monitoring and control. The high-speed GC x GC analysis of naphtha is accomplished through short GC columns, high carrier gas velocities, and partial chromatographic peak resolution followed by multivariate quantitative analysis. Six min GC x GC separations are analyzed with trilinear partial least squares (tri-PLS) to predict the aromatic and naphthene (cycloalkanes) content of naphtha samples. The 6-min GC x GC separation time is over 16 times faster than a single-GC-column standard method in which a single-column separation resolves the aromatic and naphthene compounds in naphtha and predicts the aromatic and naphthene percent concentrations through addition of the resolved signals. Acceptable quantitative precision is provided by GC x GC/tri-PLS.

Sar studies of piperidine-based analogues of cocaine. Part 3: oxadiazoles

The synthesis of novel 4beta-aryl-1-methyl-3alpha-(3-substituted-1,2,4-oxadiazol-5-yl)piperidines, bioisosteres of ester (+)-1, is described. The synthesized oxadiazoles were evaluated for their affinity to the DAT and their ability to inhibit monoamine reuptake at the DAT, NET, and 5HTT. The results show that affinity to the DAT and ability to inhibit the reuptake at the DAT, NET, and 5HTT is a function of the size of the substituent in the oxadiazole ring. (+)-(3R,4S)-4beta-(4-Chlorophenyl)-1-methyl-3alpha-(3-methyl-1,2,4-oxadiazol-5-yl)piperidine [(+)-2a], which is structurally and pharmacologically most similar to the ester (+)-1 in this series, showed at least a 2-fold longer duration of action when compared to ester (+)-1.

Drosophila homolog of the myotonic dystrophy-associated gene, SIX5, is required for muscle and gonad development

SIX5 belongs to a family of highly conserved homeodomain transcription factors implicated in development and disease. The mammalian SIX5/SIX4 gene pair is likely to be involved in the development of mesodermal structures. Moreover, a variety of data have implicated human SIX5 dysfunction as a contributor to myotonic dystrophy type 1 (DM1), a condition characterized by a number of pathologies including muscle defects and testicular atrophy. However, this link remains controversial. Here, we investigate the Drosophila gene, D-Six4, which is the closest homolog to SIX5 of the three Drosophila Six family members. We show by mutant analysis that D-Six4 is required for the normal development of muscle and the mesodermal component of the gonad. Moreover, adult males with defective D-Six4 genes exhibit testicular reduction. We propose that D-Six4 directly or indirectly regulates genes involved in the cell recognition events required for myoblast fusion and the germline:soma interaction. While the exact phenotypic relationship between D-Six4 and SIX4/5 remains to be elucidated, the defects in D-Six4 mutant flies suggest that human SIX5 should be more strongly considered as being responsible for the muscle wasting and testicular atrophy phenotypes in DM1.

Role of stromelysin 1 and gelatinase B in experimental acute lung injury

Matrix metalloproteinases (MMPs) are upregulated locally in sites of inflammation, including the lung. Several MMP activities are upregulated in acute lung injury models but the exact role that these MMPs play in the development of the lung injury is unclear due to the absence of specific inhibitors. To determine the involvement of individual MMPs in the development of lung injury, mice genetically deficient in gelatinase B (MMP-9) and stromelysin 1 (MMP-3) were acutely injured with immunoglobulin G immune complexes and the intensity of the lung injury was compared with genetically identical wild-type (WT) mice with normal MMP activities. In the WT mice there was upregulation of gelatinase B and stromelysin 1 in the injured lungs which, as expected, was absent in the genetically deficient gelatinase B- and stromelysin 1-deficient mice, respectively. In the deficient mice there was little in the way of compensatory upregulation of other MMPs. The gelatinase B- and the stromelysin 1-deficient mice had less severe lung injury than did the WT controls, suggesting that both MMPs are involved in the pathogenesis of the lung injury. Further, the mechanism of their involvement in the lung injury appears to be different, with the stromelysin 1-deficient mice having a reduction in the numbers of neutrophils recruited into the lung whereas the gelatinase B-deficient mice had the same numbers of lung neutrophils as did the injured WT controls. These studies indicate, first, that both gelatinase B and stromelysin 1 are involved in the development of experimental acute lung injury, and second, that the mechanisms by which these individual MMPs function appear to differ.

The role of metalloelastase in immune complex-induced acute lung injury

Matrix metalloproteases (MMPs) are a group of zinc-dependent endopeptidases that can degrade every component of the extracellular matrix. Under normal circumstances, the levels of MMPs are tightly regulated at both transcriptional and posttranscriptional levels. However, they are up-regulated in pathological states such as inflammation. Previous investigations have suggested that MMP-12 (metalloelastase) may be an important mediator in the pathogenesis of chronic lung injury. In this study we investigated the role of metalloelastase in the pathogenesis of acute lung injury using mice containing a targeted disruption of the metalloelastase gene. Neutrophil influx into the alveolar space in metalloelastase-deficient animals was reduced to approximately 50% of that observed in parent strain mice following the induction of injury by immune complexes. In addition, lung permeability in metalloelastase-deficient mice was approximately 50% of that of injured parent strain animals with normal levels of metalloelastase and this was correlated with histological evidence of less lung injury in the metalloelastase-deficient animals. Collectively, the data suggest that metalloelastase is necessary for the full development of acute alveolitis in this model of lung injury. Further, the data suggest that reduced injury in metalloelastase-deficient mice is due in part to decreased neutrophil influx into the alveolar space.

Induction of mutant lymphocytes in cyclophosphamide- and chlorambucil-treated patients

Monitoring patients treated with single antineoplastic agents is aiding our understanding of what hazard these drugs pose in vivo. In this study, the frequency of mutant 6-thioguanine-resistant (TG(R)) peripheral blood lymphocytes was monitored before treatment and for < or =35 weeks after treatment of patients with cyclophosphamide (CP) or chlorambucil (CAB). The mean mutant frequency before treatment for six multiple sclerosis patients treated with high-dose CP was 2.53 x 10(-5) and increased after treatment to 4.61 x 10(-5) (P = 0.08, paired t-test). Using each patient as their own control, there were significant increases (each at P < 0.04) detectable within 2-4 weeks in four of the multiple sclerosis patients treated with CP. There was no increase in an untreated control monitored over the same period. In a patient receiving five sequential CP treatments at 1 month intervals, there were cumulative increases in the frequency of mutant cells. The mutant frequency increased from 0.31 x 10(-5) before treatment to 3.64 x 10(-5) after the final treatment and had decreased to 0.53 x 10(-5) at 35 weeks after treatment. In one of two CAB-treated patients with indolent non-Hodgkin's lymphoma, there was a significant increase in mutant frequency (P < 0.03) after treatment. Freshly isolated peripheral blood lymphocytes treated with 4-hydroperoxy-CP in vitro demonstrate a dose-dependent increase in mutant frequency. The increment in mutant frequency observed in vivo is of the order expected from the in vitro experiments. Although this study demonstrates that single or multiple doses of a single antineoplastic agent are mutagenic in vivo for some patients, further studies are needed to determine the extent and mechanism of the inter-individual variations in mutagenic response.

Matrix metalloproteinases (MMPs) in fresh human prostate tumour tissue and organ-cultured prostate tissue: levels of collagenolytic and gelatinolytic MMPs are low, variable and different in fresh tissue versus organ-cultured tissue

Prostate tissue was obtained from 22 radical prostatectomies (performed for clinical management of prostate carcinoma) immediately after surgery. A small piece of tissue was fixed immediately in formalin and used for routine histology while a second piece was frozen in OCT and used for immuno-histochemistry. Another small piece was used for isolation of epithelial and stromal cells. The remainder of the tissue was cut into 2 x 2 mm pieces and incubated in organ culture for 8 days. In organ culture, non-malignant, basal epithelial cells underwent a proliferative response. This was accompanied by de-differentiation of glandular structures and by migration of epithelial cells across the surface of the tissue. Erosion of the basement membrane could also be seen in places, but was not widespread. Invasion of epithelial cells into the adjacent stroma was not evident. Production of matrix metalloproteinases (MMPs) with gelatinolytic activity or collagenolytic activity was assessed in organ culture and compared to expression patterns in fresh tissue. MMP-1 (interstitial collagenase) and MMP-9 (92-kDa gelatinase B) were undetectable or low in fresh tissue specimens. Both enzymes were detected in organ culture and both increased over time. Even after 6 days, however, there was only a low level of gelatin-hydrolytic activity and no measurable collagen-hydrolytic activity. In past studies we used organ cultures of normal skin and malignant skin tumours (basal cell carcinomas) to help elucidate the role of collagenolytic and gelatinolytic MMPs in epithelial cell invasion (Varani et al, 2000). Compared to MMP levels observed in skin, levels of these enzymes in prostate are low. The low level of collagenolytic and gelatinolytic MMPs in fresh prostate tissue and in organ-cultured prostate tissue may help explain why there is little tissue destruction in many primary prostate tumours and why the majority of such tumours remain confined to the prostate for extended periods.

Plasma fibronectin supports neuronal survival and reduces brain injury following transient focal cerebral ischemia but is not essential for skin-wound healing and hemostasis

Fibronectin performs essential roles in embryonic development and is prominently expressed during tissue repair. Two forms of fibronectin have been identified: plasma fibronectin (pFn), which is expressed by hepatocytes and secreted in soluble form into plasma; and cellular fibronectin (cFn), an insoluble form expressed locally by fibroblasts and other cell types and deposited and assembled into the extracellular matrix. To investigate the role of pFn in vivo, we generated pFn-deficient adult mice using Cre-loxP conditional gene-knockout technology. Here we show that pFn-deficient mice show increased neuronal apoptosis and larger infarction areas following transient focal cerebral ischemia. However, pFn is dispensable for skin-wound healing and hemostasis.

Role of Sertoli cells in injury-associated testicular germ cell apoptosis

This review examines experimental models of Sertoli cell injury resulting in germ cell apoptosis. Since germ cells exist in an environment created by Sertoli cells, paracrine signaling between these intimately associated cells must regulate the process of germ cell death. Germ cell apoptosis may be signaled by a decrease in Sertoli cell pro-survival factors, an increase in Sertoli cell pro-apoptotic factors, or both. The different models of Sertoli cell injury indicate that spermatogenesis is susceptible to disruption, and that targeting critical Sertoli cell functions can lead to rapid and massive germ cell death.

Effect of rate and inspiratory flow on ventilator-induced lung injury

BACKGROUND

We examined the effects of decreasing respiratory rate (RR) at variable inspiratory times (It) and reducing inspiratory flow on the development of ventilator-induced lung injury.

METHODS

Forty sheep weighing 24.6+/-3.2 kg were ventilated for 6 hours with one of five strategies (FIO2 = 1.0, positive end-expiratory pressure = 5 cm H2O): (1) pressure-controlled ventilation (PCV), RR = 15 breaths/min, peak inspiratory pressure (PIP) = 25 cm H2O, n = 8; (2) PCV, RR = 15 breaths/min, PIP = 50 cm H2O, n = 8; (3) PCV, RR = 5 breaths/min, PIP = 50 cm H2O, It = 6 seconds, n = 8; (4) PCV, RR = 5 breaths/min, PIP = 50 cm H2O, It = 2 seconds, n = 8; and (5) limited inspiratory flow volume-controlled ventilation, RR = 5 breaths/min, pressure-limit = 50 cm H2O, flow = 15 L/min, n = 8.

RESULTS

Decreasing RR at conventional flows did not reduce injury. However, limiting inspiratory flow rate (LIFR) maintained compliance and resulted in lower Qs/Qt (HiPIP = 38+/-18%, LIFR = 19+/-6%, p < 0.001), reduced histologic injury (HiPIP = 14+/-0.9, LIFR = 2.2+/-0.9, p < 0.05), decreased intra-alveolar neutrophils (HiPIP = 90+/-49, LIFR = 7.6+/-3.8,p = 0.001), and reduced wet-dry lung weight (HiPIP = 87.3+/-8.5%, LIFR = 40.8+/-17.4%,p < 0.001).

CONCLUSIONS

High-pressure ventilation for 6 hours using conventional flow patterns produces severe lung injury, irrespective of RR or It. Reduction of inspiratory flow at similar PIP provides pulmonary protection.

MRI in the management of scaphoid fractures in skeletally immature patients

BACKGROUND

The scaphoid is the commonest fractured carpal bone, but excluding a scaphoid fracture with plain radiographs is difficult. Other imaging modalities are being increasingly evaluated in the management of scaphoid injuries. MRI has been shown to be of considerable value in the adult population but there have been limited studies of its use in children.

PURPOSE

To evaluate the role of MRI in the acute management of suspected scaphoid injuries in children.

METHODS AND MATERIALS

Fifty-six children (57 injuries) who had a suspected scaphoid injury underwent MRI within 10 days of their initial trauma. The results of MRI were used to dictate management of the injury.

RESULTS

In 33 (58%) of the 57 injuries, MRI was normal and the patient was discharged from care. In 16 cases (28%), a fractured scaphoid was diagnosed and appropriate treatment started early. Additionally, other fractures around the wrist joint and ganglion cysts were demonstrated on MRI.

CONCLUSIONS

MRI of acute scaphoid injuries in children significantly alters management. Those children with normal scans are discharged earlier. Scaphoid fractures are confirmed earlier and other pathological conditions are also detected.

Clinical performance of an in-line point-of-care monitor in neonates

OBJECTIVE

To evaluate the bias, precision, and blood loss characteristics of an ex vivo in-line point-of-care testing blood gas and electrolyte monitor designed for use in critically ill newborn infants.

STUDY DESIGN

Study participants included consecutive neonates with an umbilical artery catheter (UAC) in use for clinical laboratory testing. The in-line monitor (VIA LVM Blood Gas and Chemistry Monitoring System, VIA Medical, San Diego, CA) was directly connected to the participant's UAC and the monitor's determinations of pH, PCO(2), PO(2), sodium, potassium, and hematocrit (Hct) were compared with those simultaneously drawn and measured with a standard bench top laboratory instrument (Radiometer 625 ABL; Radiometer America, Inc, Westlake, OH). The bias (the mean difference from the reference method) and precision (1 standard deviation of the mean difference) performance criteria of the in-line monitor were derived using standard laboratory procedures.

RESULTS

Sixteen neonates monitored for a total of 37 days had a total of 229 paired blood samples available for comparison by the 2 methods. Bias and precision performance characteristics of the in-line monitor were similar to reports of other point-of-care devices (ie, pH: -.003 +/-.024; PCO(2):.35 +/- 2.84 mm Hg; PO(2):.39 +/- 7.30 mm Hg; sodium:.52 +/- 2.34 mmol/L; potassium:.17 +/-.18 mmol/L; and Hct:.61 +/- 2.80%). The range of values observed for each parameter included much of the range anticipated among critically ill neonates (ie, pH: 7.15-7.65; PCO(2): 25-75 mm Hg; PO(2): 25-275 mm Hg; sodium: 127-150 mmol/L; potassium: 2.6-5.5 mmol/L; and Hct: 32%-60%). Mean blood loss (+/- standard deviation) per sample with the in-line monitor was approximately one-tenth that of the reference method: 24 +/- 7 microL versus 250 microL, respectively. There was no evidence of hemolysis and no patient related safety issues were identified with use of the in-line monitor.

CONCLUSIONS

Repeated laboratory testing of critically ill neonates using an ex vivo in-line monitor designed for use in neonates provides reliable laboratory results. The blood loss and hemolysis data obtained suggests that this monitoring device offers potential for reducing neonatal blood loss-and possibly transfusion needs-during the first weeks of life. Before this promising technology can be routinely recommended for care of critically ill neonates, greater practical experience in a variety of clinical settings is needed.

Phlebotomy overdraw in the neonatal intensive care nursery

OBJECTIVE

Because blood loss attributable to laboratory testing is the primary cause of anemia among preterm infants during the first weeks of life, we quantified blood lost attributable to phlebotomy overdraw, ie, excess that might be avoided. We hypothesized that phlebotomy overdraw in excess of that requested by the hospital laboratory was a common occurrence, that clinical factors associated with excessive phlebotomy loss would be identified, and that some of these factors are potentially correctable. DESIGN, OUTCOME MEASURES, AND ANALYSIS: Blood samples drawn for clinical purposes from neonates cared for in our 2 neonatal special care units were weighed, and selected clinical data were recorded. The latter included the test performed; the blood collection container used; the infant's location (ie, neonatal intensive care unit [NICU] and intermediate intensive care unit); the infant's weight at sampling; and the phlebotomist's level of experience, work shift, and clinical role. Data were analyzed by univariate and multivariate procedures. Phlebotomists included laboratory technicians stationed in the neonatal satellite laboratory, phlebotomists assigned to the hospital's central laboratory, and neonatal staff nurses. Phlebotomists were considered experienced if they had worked in the nursery setting for >1 year. Blood was sampled from a venous or arterial catheter or by capillary stick from a finger or heel. Blood collection containers were classified as tubes with marked fill-lines imprinted on the outside wall, tubes without fill-lines, and syringes. Infants were classified by weight into 3 groups: <1 kg, 1 to 2 kg, and >2 kg. The volume of blood removed was calculated by subtracting the weight of the empty collection container from that of the container filled with blood and dividing by the specific gravity of blood, ie, 1.050 g/mL. The volume of blood withdrawn for individual laboratory tests was expressed as a percentage of the volume requested by the hospital laboratory.

RESULTS

The mean (+/- standard error of the mean) volume of blood drawn for the 578 tests drawn exceeded that requested by the hospital laboratory by 19.0% +/- 1.8% per test. The clinical factors identified as being significantly associated with greater phlebotomy overdraw in the multiple regression model included: 1) collection in blood containers without fill-lines; 2) lighter weight infants; and 3) critically ill infants being cared for in the NICU. Because the overall R(2) of the multiple regression for these 3 clinical factors was only.24, the random factor of individual phlebotomist was added to the model. This model showed that there was a significant variation in blood overdraw among individual phlebotomists, and as a result, the overall R(2) increased to.52. An additional subset analysis involving 2 of the 3 groups of blood drawers (ie, hospital and neonatal laboratory phlebotomists) examining the effect of work shift, demonstrated that there was significantly greater overdraw for blood samples obtained during the evening shift, compared with the day shift when drawn using unmarked tubes for the group of heavier infants cared for in the NICU.

CONCLUSION

Significant volumes of blood loss are attributable to overdraw for laboratory testing. This occurrence likely exacerbates the anemia of prematurity and may increase the need for transfusions in some infants. Attempts should be made to correct the factors involved. Common sense suggests that blood samples drawn in tubes with fill-lines marked on the outside would more closely approximate the volumes requested than those without. Conversely, the use of unmarked tubes could lead to phlebotomy overdraw because phlebotomists may overcompensate to avoid having to redraw the sample because of an insufficient volume for analysis. We were surprised to observe that the lightest and most critically ill infants experienced the greatest blood overdraw. (ABSTRACT TRUNCATED)

Role of macrophage inflammatory protein-2 in aspiration-induced lung injury

OBJECTIVE

To determine the role of the chemokine, macrophage inflammatory protein (MIP)-2, in the pathogenesis of aspiration-induced lung injury in the rat.

DESIGN

Prospective, randomized, controlled animal study.

SETTING

University research laboratories.

SUBJECTS

Adult, male Long-Evans rats.

INTERVENTIONS

Anesthetized rats underwent induction of lung injury by well-described models of aspiration triggered by intra-tracheal delivery of acid alone, gastric particles alone, or the combination. After injury, induction of MIP-2 messenger RNA in whole lungs and immunoreactive MIP-2 in bronchoalveolar lavage (BAL) fluids was determined. The contribution of MIP-2 to BAL fluid chemotactic activity was defined by using an in vitro chemotaxis assay. The in vivo effect of blocking MIP-2 on pulmonary vascular leak, BAL fluid neutrophils, PaO2/FIO2 ratio, and alveolar-arterial oxygen tension gradient in acid-induced lung injury was determined.

MEASUREMENTS AND MAIN RESULTS

Induction of MIP-2 messenger RNA and protein over time was observed in response to all three stimuli. A significant portion (25% to 41%) of the chemotactic activity in BAL fluids from injured rats was inhibited by anti-MIP-2 antibody. After acid injury, blocking of MIP-2 was associated with a 53% decrease in BAL fluid neutrophils and a 33% decrease in pulmonary vascular leak. Although acid injury both impaired oxygenation and increased venous admixture, in vivo blocking of MIP-2 was associated with improved oxygenation as well as decreased venous admixture.

CONCLUSIONS

MIP-2 was up-regulated during the development of aspiration-induced lung injury in rats. MIP-2 contributed to lung accumulation of neutrophils via a chemotactic mechanism. Although oxygenation and venous admixture are worsened by acid-induced lung injury in vivo, blocking of MIP-2 at the onset of injury improved these physiologic alterations. Because the aspiration event often is witnessed, chemokines may be valid therapeutic targets for inhibiting the subsequent inflammatory response.

Time-dependent inhibition of immune complex-induced lung injury by catalase: relationship to alterations in macrophage and neutrophil matrix metalloproteinase elaboration

Rats were subjected to acute lung injury by the intra-alveolar formation of IgG immune complexes of bovine serum albumin (BSA) and anti-BSA. In this model of injury, complement activation occurs and large numbers of neutrophils invade the interstitium and alveolar space. In the present study, animals were treated with intratracheal catalase concomitantly with anti-BSA or after a lag period of 5-120 min. Catalase treatment at time-zero or at 5 min post injury failed to prevent lung injury as indicated by permeability change, histological features, and neutrophil influx. However, treatment after a delay of 15-30 min (but not 120 min) afforded substantial protection. Consistent with past findings [19], lung injury was accompanied by an accumulation of matrix metalloproteinase 9 (MMP-9) in bronchoalveolar lavage (BAL) fluid. There was a strong correlation between inhibition of injury and reduction in MMP-9 levels. In vitro studies conducted in parallel revealed that unstimulated alveolar macrophages did not produce measurable MMP-9, while there was a large induction following exposure to the same immune complexes that initiated injury in vivo. MMP-2 was also slightly upregulated under the same conditions. Concomitant treatment with catalase greatly inhibited MMP-9 production by macrophages in response to immune complexes, but this treatment had little effect on basal production of either MMP-9 or MMP-2 by macrophage. The same concentration of catalase that suppressed MMP-9 elaboration also inhibited the production of tumor necrosis factor alpha. In contrast, when neutrophils were treated with catalase and then exposed to immune complexes, the antioxidant failed to prevent the release of either MMP-2 or MMP-9. Taken together, these findings demonstrate that antioxidant treatment interferes with elaboration of MMPs by alveolar macrophages. Protection against lung injury is correlated with reduction in MMP levels in the BAL fluid.

Functional analysis of the homeodomain protein SIX5

SIX5 (previously known as myotonic dystrophy associated homeodomain protein - DMAHP ) is a member of the SIX [ sine oculis homeobox (Drosophila ) homologue ] gene family which encodes proteins containing a SIX domain adjacent to a homeo-domain. To investigate the DNA binding specificities of these two domains in SIX5, they were expressed as GST fusion proteins, both separately and together. Affinity purified recombinant proteins and cell lysates from bacteria expressing the recombinant proteins were used in gel retardation assays with double stranded oligonucleotides representing putative DNA binding sites. The putative sites included two in the promoter region of DMPK (dystrophia myotonica protein kinase ) and the previously characterised murine Six4 DNA binding site in the Na(+)/K(+) ATPase alpha 1 subunit gene ( ATP1A1 ) regulatory element (ARE). None of the recombinant proteins showed any affinity for the two putative sites in DMPK. However, the two recombinant proteins containing the homeodomain both formed at least one specific complex with the ARE. The recombinant protein containing both domains formed a second specific complex with the ARE, assumed to be a dimer complex. Finally, a whole genome PCR-based screen was used to identify genomic DNA sequences to which SIX5 binds, as an initial stage in the identification of genes regulated by SIX5.

Structure, mapping and expression of the human gene encoding the homeodomain protein, SIX2

Vertebrate genes with sequence similarity to the Drosophila homeobox gene, sine oculis (so), constitute the SIX family. There is notable expression of members of this family in anterior neural structures, and several SIX genes have been shown to play roles in vertebrate and insect development, or have been implicated in maintenance of the differentiated state of tissues. Mutations in three of these genes in man (SIX5, SIX6 and SIX3) are associated with severe phenotypes, and therefore, the cloning of other human genes from this family is of interest. We have cloned and characterised the gene that encodes human SIX2, elucidated its gene structure and conducted expression studies in a range of tissues. SIX2 is widely expressed in the late first-trimester fetus, but has a limited range of expression sites in the adult. The expression pattern of SIX2 and its localisation to chromosome 2p15-p16 will be of use in assessing its candidacy in human developmental disorders.

Neonatal laboratory blood sampling: comparison of results from arterial catheters with those from an automated capillary device

PURPOSE

To compare neonatal laboratory results from capillary blood samples drawn using the Tenderfoot automated capillary sampling device with those drawn through arterial catheters.

DESIGN

Prospective, paired comparisons of laboratory results from capillary and arterial blood.

SAMPLE

Twenty-one infants being cared for in an NICU and having indwelling arterial catheters through which a variety of predominantly glucose-containing fluids were being administered.

MAIN OUTCOME VARIABLES

Statistical comparisons of paired capillary and arterial results of pH, PO2, PCO2, lactate, sodium, potassium, ionized calcium, and hematocrit.

RESULTS

No capillary-arterial differences were observed for pH, PCO2, lactate, or sodium. Although capillary results were slightly, but significantly (p < .01), higher for potassium (+0.4 mEq/liter), ionized calcium (+0.47 mg/dl), and hematocrit (+4 percent), these differences fell within acceptable Clinical Laboratories Improvement Act (CLIA) performance criteria. Markedly lower PO2 (-30.2 mmHg) and glucose (-61 mg/dl) values were observed with capillary sampling. With the exception of results for PaO2 and plasma glucose, capillary blood drawn using the Tenderfoot automated device yields laboratory results comparable to those from blood drawn from arterial catheters as assessed by CLIA performance criteria.

Multiple cadherin superfamily members with unique expression profiles are produced in rat testis

Adhesion between germ and Sertoli cells is thought to be crucial for spermatogenesis. Cadherin superfamily proteins, including classic cadherins and protocadherins, are important mediators of cell-cell adhesion. Using a degenerate PCR cloning strategy, we surveyed the expression of cadherin superfamily members in rat testis. Similar to brain, testis expressed a large number of cadherin superfamily members: 7 classic cadherins of both types I and II, 14 protocadherins, 2 protocadherin-related cadherins, and 1 cadherin-related receptorlike protein. All three protocadherin families (alpha, beta, and gamma) were found in testis. Using a semiquantitative RT-PCR assay, messenger RNA expression was determined for each cadherin superfamily member during a postnatal developmental time-course and following ablation of specific testis cell types by ethanedimethanesulfonate, methoxyacetic acid, and 2,5-hexanedione. Diverse expression patterns were observed among the cadherins, suggesting that cadherin expression is cell type-specific in testis. The large number and variety of cadherin superfamily members found in testis supports a critical function for cadherin-mediated cell-cell adhesion in spermatogenesis.

Prevention of murine influenza A virus pneumonitis by surfactant nano-emulsions

Non-ionic surfactant nano-emulsions have extensive anti-microbial activity and are biocompatible with skin and mucous membranes at effective concentrations. Two nano-emulsion formulations (8N8 and 20N10) made from soybean oil, tributyl phosphate and Triton X-100, were tested for their ability to prevent murine influenza virus pneumonia in vivo. In the initial study, CD-1 mice were administered various dilutions of the nano-emulsions intranasally, and safe dosages and concentrations were determined. Non-toxic concentrations of the nano-emulsions were then mixed with influenza virus and applied to the nares of mice. Animals receiving mixtures of two different emulsions (8N8 or 20N10) and a LD50 of virus survived the challenge without evidence of viral infection. To determine if the nano-emulsions could prevent influenza virus infection in vivo when used as a prophylactic treatment, the nano-emulsions (8N8 at 1.0% and 20N10 at 1.0% or 0.2%) were applied to mouse nares 90 min before exposure to 5x10(5) p.f.u./ml virus by nebulized aerosol. Animals pretreated with the nano-emulsions had significantly decreased clinical signs of infection. Only 26.0% (8N8 at 1.0%), 31.25% (20N10 at 1.0%) and 37.0% (20N10 at 0.2%) of animals pretreated with nano-emulsion died from pneumonitis, whereas >80.0% of mock pretreated animals succumbed to infection (P<0.005). These findings suggest that non-ionic surfactant nano-emulsions have therapeutic potential for the prevention of influenza virus infection in vivo.

Genetic linkage and radiation hybrid mapping of the three human GABA(C) receptor rho subunit genes: GABRR1, GABRR2 and GABRR3

GABA(C) receptors mediate rapid inhibitory neurotransmission in retina. We have mapped, in detail, the human genes which encode the three polypeptides that comprise this receptor: rho1 (GABRR1), rho2 (GABRR2) and rho3 (GABRR3). We show that GABRR1 and GABRR2 are located close together, in a region of chromosome 6q that contains loci for inherited disorders of the eye, but that GABRR3 maps to chromosome 3q11-q13.3. Our mapping data suggest that the rho polypeptide genes, which are thought to share a common ancestor with GABA(A) receptor subunit genes, diverged at an early stage in the evolution of this gene family.