Evidence for budding of human immunodeficiency virus type 1 selectively from glycolipid-enriched membrane lipid rafts

A number of recent studies have demonstrated the significance of detergent-insoluble, glycolipid-enriched membrane domains or lipid rafts, especially in regard to activation and signaling in T lymphocytes. These domains can be viewed as floating rafts composed of sphingolipids and cholesterol which sequester glycosylphosphatidylinositol (GPI)-linked proteins, such as Thy-1 and CD59. CD45, a 200-kDa transmembrane phosphatase protein, is excluded from these domains. We have found that human immunodeficiency virus type 1 (HIV-1) particles produced by infected T-cell lines acquire the GPI-linked proteins Thy-1 and CD59, as well as the ganglioside GM1, which is known to partition preferentially into lipid rafts. In contrast, despite its high expression on the cell surface, CD45 was poorly incorporated into virus particles. Confocal fluorescence microscopy revealed that HIV-1 proteins colocalized with Thy-1, CD59, GM1, and a lipid raft-specific fluorescent lipid, DiIC(16)(3), in uropods of infected Jurkat cells. CD45 did not colocalize with HIV-1 proteins and was excluded from uropods. Dot immunoassay of Triton X-100-extracted membrane fractions revealed that HIV-1 p17 matrix protein and gp41 were present in the detergent-resistant fractions and that [(3)H]myristic acid-labeled HIV Gag showed a nine-to-one enrichment in lipid rafts. We propose a model for the budding of HIV virions through lipid rafts whereby host cell cholesterol, sphingolipids, and GPI-linked proteins within these domains are incorporated into the viral envelope, perhaps as a result of preferential sorting of HIV Gag to lipid rafts.

Lipid rafts and HIV pathogenesis: host membrane cholesterol is required for infection by HIV type 1

In a previous study we showed that budding of HIV-1 particles occurs at highly specialized membrane microdomains known as lipid rafts. These microdomains are characterized by a distinct lipid composition that includes high concentrations of cholesterol, sphingolipids, and glycolipids. Since cholesterol is known to play a key role in the entry of some other viruses, our observation of HIV budding from lipid rafts led us to investigate the role in HIV-1 entry of cholesterol and lipid rafts in the plasma membrane of susceptible cells. We have used 2-OH-propyl-beta-cyclodextrin (beta-cyclodextrin) to deplete cellular cholesterol and disperse lipid rafts. Our results show that removal of cellular cholesterol rendered primary cells and cell lines highly resistant to HIV-1-mediated syncytium formation and to infection by both CXCR4- and CCR5-specific viruses. beta-Cyclodextrin treatment of cells partially reduced HIV-1 binding, while rendering chemokine receptors highly sensitive to antibody-mediated internalization. There was no effect on CD4 expression. All of the above-described effects were readily reversed by incubating cholesterol-depleted cells with low concentrations of cholesterol-loaded beta-cyclodextrin to restore cholesterol levels. Cholesterol depletion made cells resistant to SDF-1-induced binding to ICAM-1 through LFA-1. Since LFA-1 contributes significantly to cell binding by HIV-1, this latter effect may have contributed to the observed reduction in HIV-1 binding to cells after treatment with beta-cyclodextrin. Our results indicate that cholesterol may be critical to the HIV-1 coreceptor function of chemokine receptors and is required for infection of cells by HIV-1.

Binding of urokinase-type plasminogen activator to its receptor in MCF-7 cells activates extracellular signal-regulated kinase 1 and 2 which is required for increased cellular motility

Binding of urokinase-type plasminogen activator (uPA) to its receptor, uPAR, regulates cellular adhesion, migration, and tumor cell invasion. Some of these activities may reflect the ability of uPAR to initiate signal transduction even though this receptor is linked to the plasma membrane only by a glycosylphosphatidylinositol anchor. In this study, we demonstrated that single-chain uPA activates extracellular signal-regulated kinase 1 (ERK1) and ERK2 in MCF-7 breast cancer cells. Phosphorylation of ERK1 and ERK2 was increased 1 min after adding uPA and returned to baseline levels by 5 min. The amino-terminal fragment (ATF) of uPA, which binds to uPAR but lacks proteinase activity, also activated ERK1 and ERK2. Responses to uPA and ATF were eliminated when the cells were pretreated with PD098059, an inhibitor of mitogen-activated protein kinase kinase. uPA and ATF promoted the migration of MCF-7 cells across serum-coated Transwell membranes in vitro. Migration was increased 2.1 +/- 0.4-fold when uPA was added to the top chamber, 4. 8 +/- 0.8-fold when uPA was added to the bottom chamber, and 7.7 +/- 1.0-fold when uPA was added to both chambers. MCF-7 cells that were pulse-exposed to uPA for 30 min, and then washed to remove unbound ligand, demonstrated increased motility even though migration was allowed to occur for 24 h. PD098059 completely neutralized the effects of uPA on MCF-7 cellular motility, irrespective of whether the uPA was present for the entire motility assay or administered by pulse-exposure. These results demonstrate a novel, receptor-dependent signaling activity which is required for uPA-stimulated breast cancer cell migration.

The syndrome of dysuria and hematuria in pediatric urinary reconstruction with stomach

Between July 1989 and March 1992 at a single institution 27 male and 30 female patients underwent lower urinary reconstruction with stomach. Mean patient age was 9.9 years (range 1.5 to 28 years). The diagnoses were epispadias/exstrophy complex (19 patients), myelodysplasia (11), cloacal exstrophy (6), posterior urethral valves (6), Hinman syndrome (4), sacral agenesis (3) and other (8). Indications for surgery were urinary incontinence, upper tract deterioration or undiversion. A total of 54 patients underwent augmentation gastrocystoplasty and 3 had total bladder replacement. Mean followup time was 23.2 months (range 12 to 39 months). The syndrome of dysuria and hematuria is defined as 1 or a combination of the following symptoms: bladder spasm or suprapubic, penile or periurethral pain, coffee brown or bright red hematuria without infections, skin irritation or excoriation and dysuria without infections. Telephone and clinic interviews identified 21 patients (36%) with symptoms of the dysuria and hematuria syndrome. The most common symptoms were hematuria (71%) and bladder or suprapubic pain (76%). Of the patients 18 (86%) ranked the severity of symptoms as mild to moderate and 3 (14%) ranked them as severe. No medications were required to control the symptoms in 13 patients (62%) and 3 other patients only required medications on an as needed basis. Overall patients who required no medications had lower symptom scores than those who required medications. Patients with decreased renal function may be more at risk for the dysuria and hematuria syndrome than those with normal renal function. Patients who were wet were more prone to have the dysuria and hematuria syndrome than those who were totally dry. The pathophysiology of the dysuria and hematuria syndrome is currently unknown. Patients who require urinary reconstruction with stomach tissue need to be made aware of the potential of the dysuria and hematuria syndrome.

A meta-analytic review of gender differences in perceptions of sexual harassment

Research on gender differences in perceptions of sexual harassment informs an ongoing legal debate regarding the use of a reasonable person standard instead of a reasonable woman standard to evaluate sexual harassment claims. The authors report a meta-analysis of 62 studies of gender differences in harassment perceptions. An earlier quantitative review combined all types of social-sexual behaviors for a single meta-analysis; the purpose of this study was to investigate whether the magnitude of the female-male difference varies by type of behavior. An overall standardized mean difference of 0.30 was found, suggesting that women perceive a broader range of social-sexual behaviors as harassing. However, the meta-analysis also found that the female-male difference was larger for behaviors that involve hostile work environment harassment, derogatory attitudes toward women, dating pressure, or physical sexual contact than sexual propositions or sexual coercion.

Extracellular signal-regulated kinase functions in the urokinase receptor-dependent pathway by which neutralization of low density lipoprotein receptor-related protein promotes fibrosarcoma cell migration and matrigel invasion

The low density lipoprotein receptor-related protein (LRP) has been reported to regulate cellular migration. In this study, an antisense RNA expression strategy was used to reduce LRP to undetectable levels in HT 1080 fibrosarcoma cells. The LRP-deficient cells demonstrated increased levels of cell-surface uPAR, higher levels of uPA in conditioned medium, increased migration on vitronectin-coated surfaces, and increased invasion of Matrigel. LRP-deficient cells also demonstrated increased levels of phosphorylated extracellular signal-regulated kinase (ERK) in the absence of exogenous stimulants. Antibodies which block binding of endogenously produced uPA to uPAR reduced ERK phosphorylation and migration of LRP-deficient cells to the levels observed with control cells. Inhibitors of ERK activation, including PD098059 and dominant-negative MEK1, also decreased the migration of LRP-deficient but not control cells. By contrast, constitutively active MEK1 stimulated the migration of control but not LRP-deficient cells. Although Matrigel invasion by LRP-deficient cells was inhibited by the proteinase inhibitor, aprotinin, PD098059 in combination with aprotinin was necessary for an optimal effect. Expression of the VLDL receptor in LRP-deficient cells reversed the changes in cellular migration and invasion. These studies demonstrate that binding of endogenously produced uPA to uPAR may serve as a major determinant of basal levels of activated ERK and, by this mechanism, regulate cellular migration and invasion. By regulating the uPA/uPAR system, LRP may also regulate ERK activation, cellular migration, and invasion.

Urokinase-type plasminogen activator stimulates the Ras/Extracellular signal-regulated kinase (ERK) signaling pathway and MCF-7 cell migration by a mechanism that requires focal adhesion kinase, Src, and Shc. Rapid dissociation of GRB2/Sps-Shc complex is associated with the transient phosphorylation of ERK in urokinase-treated cells

Urokinase-type plasminogen activator (uPA) stimulates MCF-7 cell migration by binding to the UPA receptor and activating the Ras-extracellular signal-regulated kinase (Ras-ERK) signaling pathway. Studies presented here show that soluble uPA receptor and a peptide derived from the linker region between domains 1 and 2 of the uPA receptor also stimulate cellular migration via a mitogen-activated protein kinase/ERK kinase (MEK)-dependent pathway. Signaling proteins that function upstream of Ras in uPA- stimulated cells remain undefined. To address this problem, we transfected MCF-7 cells to express the noncatalytic carboxylterminal domain of focal adhesion kinase (FAK), FAK(Y397F), kinase-defective c-Src, or Shc FFF, all of which express dominant-negative activity. In each case, ERK phosphorylation and cellular migration in response to uPA were blocked. Both activities were rescued by co-transfecting the cells to express constitutively active MEK1, indicating that FAK, c-Src, and Shc are upstream of MEK. Shc was tyrosine-phosphorylated in uPA-treated cells. The level of phosphorylated Shc was increased within 1 min and remained increased for at least 30 min. Sos co-immunoprecipitated with Shc in cells that were treated with uPA for 1-2.5 min, probably reflecting the formation of Shc-Grb2/Sos complex; however, by 10 min, co-immunoprecipitation of Sos with Shc was no longer observed. Rapid dissociation of Sos from Shc represents a possible mechanism for the transient phosphorylation of ERK in uPA-treated MCF-7 cells.

The very low density lipoprotein receptor regulates urokinase receptor catabolism and breast cancer cell motility in vitro

The very low density lipoprotein receptor (VLDLr) binds diverse ligands, including urokinase-type plasminogen activator (uPA) and uPA-plasminogen activator inhibitor-1 (PAI-1) complex. In this study, we characterized the effects of the VLDLr on the internalization, catabolism, and function of the uPA receptor (uPAR) in MCF-7 and MDA-MB-435 breast cancer cells. When challenged with uPA.PAI-1 complex, MDA-MB-435 cells internalized uPAR; this process was inhibited by 80% when the activity of the VLDLr was neutralized with receptor-associated protein (RAP). To determine whether internalized uPAR is degraded, we studied the catabolism of [35S]methionine-labeled uPAR. In the absence of exogenous agents, the uPAR catabolism t(1)/(2) was 8.2 h. uPA.PAI-1 complex accelerated uPAR catabolism (t(1)/(2) to 1.8 h), while RAP inhibited uPAR catabolism in the presence (t(1)/(2) of 7.8 h) and absence (t(1)/(2) of 16.9 h) of uPA.PAI-1 complex, demonstrating a critical role for the VLDLr. When MCF-7 cells were cultured in RAP, cell surface uPAR levels increased gradually, reaching a new steady-state in 3 days. The amount of uPA which accumulated in the medium also increased. Culturing in RAP for 3 days increased MCF-7 cell motility by 2.2 +/- 0.1-fold and by 4.4 +/- 0.3-fold when 1.0 nM uPA was added. The effects of RAP on MCF-7 cell motility were entirely abrogated by an antibody which binds uPA and prevents uPA binding to uPAR. MCF-7 cells that were cultured in RAP demonstrated increased levels of activated mitogen-activated protein kinases. Furthermore, the MEK inhibitor, PD098059, decreased the motility of RAP-treated cells without affecting control cultures. These studies suggest a model in which the VLDLr regulates autocrine uPAR-initiated signaling and thereby regulates cellular motility.

Accumulation of PN1 and PN3 sodium channels in painful human neuroma-evidence from immunocytochemistry

BACKGROUND

The axolemmal distribution and density of voltage-gated sodium channels largely determines the electrical excitability of sprouting neurites. Recent evidence suggests that accumulation of sodium channels at injured axonal tips may be responsible for ectopic axonal hyperexcitability and the resulting abnormal sensory phenomena of pain and paresthesias. For future improvement in pain management it is necessary to identify structurally significant generators of autorhythmicity. A first step in this regard will be to determine the predominant types of sodium channels in injured axons. The opportunity to test human specimens from painful and non-painful neuroma is of great value.

METHODS

We employed immunocytochemical methods to investigate if two types of highly specific voltage-gated sodium channel subtypes could be detected in sections of human neuroma.

FINDINGS

Both subtypes of sodium channels PN1 and PN3 accumulated abnormally in human neuromas. The immunoreactive pattern was more pronounced in painful neuromas. This is in contrast to previous reports that focused either on PN1 or PN3 as main generators of hyperexcitability induced pain.

INTERPRETATION

Both, PN1 and PN3 seem to be involved in hyperexcitability induced pain. It can be expected that a variety of other highly specific voltage gated sodium channel subtypes will be detected in regenerating peripheral nerve in the near future, which contribute to the development of neuropathic pain states. Thus, in order to therapeutically control hyperexcitability induced neuropathic pain, it might be worthwhile to develop pharmaceuticals that can selectively block different sodium channel subtypes and subunits.A review of the role of sodium channels in neuropathic pain is implemented in the discussion.

Towards a minimal motif for artificial transcriptional activators

BACKGROUND

Most transcriptional activators minimally comprise two functional modules, one for DNA binding and the other for activation. Several activators also bear an oligomerization region and bind DNA as dimers or higher order oligomers. In a previous study we substituted these domains of a protein activator with synthetic counterparts [Mapp et al., Proc. Natl. Acad. Sci. USA 97 (2000) 3930-3935]. An artificial transcriptional activator, 4.2 kDa in size, comprised of a DNA binding hairpin polyamide tethered to a 20 residue activating peptide (AH) was shown to stimulate promoter specific transcription [Mapp et al., Proc. Natl. Acad. Sci. USA 97 (2000) 3930-3935]. The question arises as to the general nature and the versatility of this minimal activator motif and whether smaller ligands can be designed which maintain potent activation function.

RESULTS

Here we have replaced the 20 amino acid AH peptide with eight or 16 residues derived from the activation domain of the potent viral activator VP16. The 16 residue activation module coupled to the polyamide activated transcription over two-fold better than the analogous AH conjugate. Altering the site of attachment of the activation module on the polyamide allowed reduction of the intervening linker from 36 atoms to eight without significant diminution of the activation potential. In this study we also exchanged the polyamide to target a different sequence without compromising the activation function further demonstrating the generality of this design.

CONCLUSIONS

The polyamide activator conjugates described here represent a class of DNA binding ligands which are tethered to a second functional moiety, viz. an activation domain, that recruits elements of the endogenous transcriptional machinery. Our results define the minimal structural elements required to construct artificial, small molecule activators. If such activators are cell-permeable and can be targeted to designated sites in the genome, this series of conjugates may then serve as a tool to study mechanistic aspects of transcriptional regulation and eventually to modulate gene expression relevant to human diseases.

Outcome of renal transplantation after urinary diversion and enterocystoplasty: a retrospective, controlled study

A total of 17 patients with intestinal urinary diversion of enterocystoplasty underwent renal transplantation between 1970 and 1988. Patient age ranged from 4 to 35 years (mean age 20 years). The patients were divided into 2 groups. In group 1 (10 patients, 2 of whom required retransplantation) the ureter of the transplanted kidney was implanted into an ileal (7) or colonic (1) conduit or enterocystoplasty (2). In group 2 (7 patients, 1 of whom required a second transplant) the diversion was taken down and the transplanted ureter was implanted into the defunctionalized bladder. There were 14 living related and 6 cadaveric kidneys transplanted. Graft survival rates were 58 and 87% in groups 1 and 2, respectively, with an over-all rate of 70% (14 of 20 kidneys). There was no statistical difference in the graft survival rate between the 2 groups. The complications in group 1 included ureteroileal anastomotic leak (3 patients), ureteroileal stenosis (1), calculus formation (1), urosepsis (1), hyperchloremic metabolic acidosis (1), and wound infection and dehiscence (1). There were no complications in group 2. Renal transplantation into a pre-existing urinary intestinal conduit or augmented bladder does not statistically adversely affect patient or graft survival. However, the complication rate is much higher when the ureter is implanted into an intestinal segment. Therefore, it is preferable whenever possible to implant the ureter into the native bladder.

Compatibility of enterocystoplasty and the artificial urinary sphincter

Placement of the artificial urinary sphincter during augmentation enterocystoplasty may lead to infection, erosion and eventual removal of the device. To assess compatibility of artificial urinary sphincter implantation and enterocystoplasty we reviewed the records of 30 patients who had undergone enterocystoplasty and artificial urinary sphincter placement simultaneously (11), enterocystoplasty before artificial urinary sphincter placement (12) and artificial urinary sphincter placement before enterocystoplasty (7). The 19 male and 11 female patients were between 4 and 42 years old (median age 13.5 years). Followup in 28 patients ranged from 6 months to 8 years (average 17 months). Incontinence resulted from myelodysplasia in 16 patients, sacral agenesis in 3, spinal cord injury in 6, posterior urethral valves in 1, bilateral ectopic ureters in 1 and epispadias-exstrophy in 3. Erosion occurred in 2 patients (7 per cent): 1 female patient who underwent simultaneous sphincter implantation and enterocystoplasty and who had undergone previously many bladder neck reconstructive procedures, including polytetrafluoroethylene (Teflon) injection, and 1 female patient in whom the augmented bladder was entered at artificial urinary sphincter implantation. Mechanical failure occurred 4 times in 3 patients and the artificial urinary sphincter was improperly placed in 1. Over-all continence rate was 87 per cent (26 of 30 patients). Simultaneous placement of the artificial urinary sphincter and enterocystoplasty did not seem to affect the outcome of sphincter implantation if good bowel preparation, intravenous antibiotics and sterility of urine were accomplished preoperatively. Entering the augmented bladder during sphincter implantation may predispose to infection and erosion.

Solid-phase synthesis of DNA binding polyamides on oxime resin

Control of the energetics and specificity of DNA binding polyamides is necessary for inhibition of protein-DNA complex formation and gene regulation studies. Typically, solid-phase methods using Boc monomers for synthesis have depended on Boc-beta-Ala-PAM resin which affords a beta-alanine-Dp tail at the C-terminus, after cleavage with N,N-dimethylaminopropylamine (Dp). To address the energetic consequences of this tail for DNA minor groove binding, we describe an alternative solid phase method employing the Kaiser oxime resin which allows the synthesis of polyamides with incrementally shortened C-terminal tails. Polyamides without Dp and having methyl amide tails rather than beta-alanine show similar affinity relative to the standard beta-Dp tail. The truncated tail diminishes the A,T base pair energetic preference of the beta-Dp tail which will allow a greater variety of DNA sequences to be targeted by hairpin polyamides.

Nonintubated Anderson-Hynes repair of ureteropelvic junction obstruction in 60 patients

We reviewed our experience with 68 consecutive Anderson-Hynes ureteropyeloplasties. The 64 infants, children and young adults ranged from 2 days to 28 years old (median age 2 years), and 28 were less than 1 year old. Intubation was used in only 4 patients: 2 who also underwent ureteral reimplantation for vesicoureteral reflux, 1 with stones in the renal pelvis and 1 with pyonephrosis. We successfully repaired 60 of 64 nonintubated renal units (93.4 per cent). Temporary postoperative ureteral stenting was required for extravasation from 8 renal units (12.5 per cent). Two patients later underwent repeat ureteropyeloplasty for recurrent obstruction. Nephrectomy was performed for pyonephrosis in 1 patient and for a nonfunctioning kidney that had exhibited poor function preoperatively in 1. Prolonged ileus necessitated extended hospitalization in 3 patients (4.6 per cent). We conclude that nonintubated dismembered ureteropyeloplasty for uncomplicated, primary ureteropelvic junction obstruction can be performed safely and successfully, and should be considered the standard treatment. Positioning of the Penrose drain is critical to avoid urinoma formation. When persistent urinary leakage occurs temporary diversion is easy and well tolerated. Hospital stay averaged 12.1 days for patients with extravasation compared to 4.3 days when no extravasation occurred. Immediate preoperative retrograde pyelography did not seem to contribute to postoperative urinary extravasation by causing edema of the ureteral orifice.

Tumor necrosis factor-related apoptosis-inducing ligand translates neonatal respiratory infection into chronic lung disease

Respiratory infections in early life can lead to chronic respiratory disease. Chlamydia infections are common causes of respiratory disease, particularly pneumonia in neonates, and are linked to permanent reductions in pulmonary function and the induction of asthma. However, the immune responses that protect against early-life infection and the mechanisms that lead to chronic lung disease are incompletely understood. Here we identify novel roles for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in promoting Chlamydia respiratory infection-induced pathology in early life, and subsequent chronic lung disease. By infecting TRAIL-deficient neonatal mice and using neutralizing antibodies against this factor and its receptors in wild-type mice, we demonstrate that TRAIL is critical in promoting infection-induced histopathology, inflammation, and mucus hypersecretion, as well as subsequent alveolar enlargement and impaired lung function. This suggests that therapeutic agents that target TRAIL or its receptors may be effective treatments for early-life respiratory infections and associated chronic lung disease.

Intraoperative cardiovascular collapse secondary to latex allergy

An apparent allergic reaction has been noted in children undergoing open urological surgery. This condition is characterized by precipitous hypotension, tachycardia and upper body flushing, and it often causes termination of the procedure. Latex allergy has been identified as the possible inciting event. Contact of latex rubber gloves with intra-abdominal structures (handling bowel) appears to be the most dramatic trigger mechanism for this reaction. We report on 10 patients with latex allergy, 6 of whom have myelomeningocele, who have undergone reconstructive surgery. Severe anaphylactic shock developed intraoperatively in 5 patients and during a barium enema performed with a latex catheter in 1 patient. These 6 patients had previous allergic reactions to latex material, which was not detected preoperatively. In the remaining 4 patients latex allergy was diagnosed preoperatively. A total of 6 patients agreed to a skin prick test to liquid latex. Three patients reacted with a wheal size greater than or equal to a histamine control at a dilution of 1:1,000 and 3 patients at 1:100. In contrast, none of the 5 normal controls reacted to any of the concentrations including full strength latex. A history of exposure to latex products (balloons, surgical gloves, catheters, condoms and so forth) with allergic reactions should heighten surgeon awareness of a potentially severe intraoperative reaction. Furthermore, a skin prick test may be used to screen high risk patients such as those with myelomeningocele. A protocol involving preoperative corticosteroid and antihistamine therapy is recommended.

Lung manganese superoxide dismutase increases during cytokine-mediated protection against pulmonary oxygen toxicity in rats

Parenteral injection of the cytokines interleukin-1 and tumor necrosis factor, or of endotoxin (lipopolysaccharide), protects rats against lethal pulmonary oxygen toxicity. To determine the potential importance of manganese superoxide dismutase (MnSOD) in this model, we measured MnSOD mRNA and activity in lung. In addition, we confirmed that increases in activities were related to changes in MnSOD protein, which was measured using an enzyme-linked immunosorbentassay (ELISA) technique. After cytokine or endotoxin administration, increases in lung MnSOD mRNA occurred promptly (4 h), with or without hyperoxic exposure. In parallel, lung MnSOD protein and activity were increased after 24 h, and protein levels remained elevated after 52 h. MnSOD activity and protein levels were closely correlated. Neither lung copper-zinc superoxide dismutase (CuZnSOD) mRNA nor activity increased following administration of cytokines. Small increases in CuZnSOD mRNA, which did not exceed those in beta-actin mRNA, occurred early (4 h) after endotoxin, but CuZnSOD activity was unchanged. Immunohistochemistry was used to demonstrate in which cell types the increase in MnSOD protein occurred after cytokine or endotoxin administration. In agreement with ELISA findings, immunoreactive MnSOD appeared to be increased in lung parenchyma, but not in lung neutrophils, 24 h after cytokine or endotoxin treatment. MnSOD was heavily concentrated in alveolar type II cells. However, the numbers of surfactant protein D-positive (type II) cells in lung sections did not appear to be increased after treatment with cytokines or endotoxin. We conclude that early and sustained increases in endogenous MnSOD, but not CuZnSOD or other antioxidant enzymes, are associated with protection of rat lungs against hyperoxic damage by cytokines or endotoxin.

Tumor necrosis factor-alpha and interleukin-1 induce activation of MAP kinase and SAP kinase in human neuroma fibroblasts

Two cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1), which are released by macrophages during the early inflammatory phase of nerve injury, are known to induce activation of mitogen-activated protein kinase (MAPK) and stress-activated protein kinase (SAPK), which locate at different signal transduction pathways and are involved in cell cycle G0/G1 transition and cellular proliferation in human fibroblasts. Activation of these two protein kinases by the cytokines may stimulate fibroblast proliferation in damaged nerves and thereby play a role in the formation of a neuroma, a disorganized mass of tissue that interferes with neural regeneration and repair. To investigate the possibility that this mechanism is operative in neuroma formation, we used cultured, serum-starved fibroblasts from surgically removed human neuromas stimulated with TNF-alpha and/or IL-1 alpha and IL-1 beta, and measured the activation of MAPK and SAPK using myelin basic protein (MBP) and human c-Jun (1-169) glutathione S-agarose transferase (GST) fusion protein as substrates. For comparison, neuroma fibroblast cultures were also stimulated with phorbol 12-myristate 13-acetate (PMA) and platelet-derived growth factor-AB (PDGF-AB), a potent activator for MAPK. TNF-alpha and both forms of IL-1 produced a rapid activation of MAPK, with a peak at 15 min for TNF-alpha stimulation, and a peak at 30 min for IL-1 stimulation. TNF-alpha combined with either IL-1 alpha or IL-1 beta produced a synergistic effect on the activation of MAPK. The increases in MAPK induced by TNF-alpha and IL-1 were similar to the increases induced by PMA and PDGF-AB. To confirm the presence of MAPK, immunoprecipitation and immunoblotting were carried out on experimental and control lysates. TNF-alpha and IL-1 also increased activation of SAPK, but to a lesser extent than MAPK. PMA and PDGF-AB were also much less effective in stimulating activation of SAPK. Our findings indicate that TNF-alpha and IL-1 activate parallel signal transduction pathways in human neuroma fibroblasts, and that they are relatively stronger activators of MAPK than of SAPK. Previous studies have convincingly demonstrated that MAPK and SAPK are involved in human fibroblast proliferation. The results of our study suggest that TNF-alpha and IL-1 may play a role in frustrating functional nerve regeneration after injury by stimulating these two kinases, which, in turn, leads to fibroblast proliferation and formation of neuromas.

Evaluation of the blend of organic acids and medium-chain fatty acids in matrix coating as antibiotic growth promoter alternative on growth performance, nutrient digestibility, blood profiles, excreta microflora, and carcass quality in broilers

This study was conducted to evaluate the effects of the blend of organic acids (OAs) and medium-chain fatty acids (MCFAs) in broiler chickens. A total of 816 1-d-old male Ross 308 broiler chickens (35 ± 0.44 g) were randomly allocated into 1 of the following 6 dietary treatments (17 broilers per pen with 8 pens per treatment): dietary treatments consisted of corn-soybean meal-based basal diet and the basal diet supplemented with 0.02, 0.03, 0.04, 0.05, and 0.06% blend of OAs and MCFAs. The study lasted 5 wk during which growth performance was determined. In the current study, the inclusion of 0.02, 0.03, 0.04, 0.05, and 0.06% blend of OAs and MCFAs in the basal diet linearly increased (P < 0.05) body weight gain and improved feed conversion ratio (P < 0.0001) on day 7 to 14, day 14 to 35, as well as overall. Increasing inclusion of the blend of OAs and MCFAs levels in the diets also linearly increased (P = 0.001) the digestibility of dry matter on day 35. Broilers fed with different levels of the blend of OAs and MCFAs showed a linear increment (P = 0.042) in Lactobacillus concentration and decrease (P = 0.002) in Escherichia coli concentration. With regard to relative organ weight, a trend of linear reduction (P = 0.052) in bursa of Fabricius weight of broilers fed the blend of OAs and MCFAs was observed. There was a significant linear improvement (P = 0.011) in the IgG concentration associated with the inclusion of the blend of OAs and MCFAs levels in the diets. In conclusion, the blend of OAs and MCFAs supplementation positively influenced growth performance, nutrient digestibility, and excreta microflora in broiler chickens.

Effect of sensory denervation on the structure and physiologic responsiveness of rabbit lacrimal gland

PURPOSE

This work was conducted to determine the effects of unilateral trigeminal ganglion ablation on lacrimal gland structure and secretory activity.

METHODS

Adult male New Zealand rabbits underwent unilateral thermocoagulation of the ophthalmic division of the trigeminal ganglion. Sensory denervation was affirmed by anatomic inspection of the lesion and transmission electron microscopy (TEM) of the lacrimal gland innervation. Eight to 10 days after the procedure, the intraorbital lacrimal glands were removed from both sides. To compare the physiologic competence of the intact and denervated glands, freshly isolated gland fragments from the paired intact and denervated glands were stimulated with carbachol (100 microM), isoproterenol (10 microM), phorbol-12,13-dibutyrate (PDBu, 10 microM), forskolin (40 microM), or vehicle. Total secreted protein was measured at 30 or 60 min after the establishment of baseline values. Intact and denervated glands also were examined by light and TEM, and the morphologic appearance of the acinar structures as well as the appearance of nerves innervating the gland after denervation were assessed. Similar experiments were conducted with animals that underwent unilateral superior cervical ganglionectomy.

RESULTS

Tissues from sensory denervated glands released significantly more protein than did tissues from innervated glands in response to in vitro stimulation by carbachol or isoproterenol but not in response to PDBu or forskolin. Microscopy showed that the acinar cells that had undergone sensory denervation showed a massive accumulation of secretory granules. The secretory granules filled the entire cytoplasmic space and displaced the ellipsoidal nuclei to the extreme periphery. Examination of segments of nerves revealed numerous unmyelinated axons, a few small-diameter myelinated axons, and a large amount of nerve degeneration after sensory denervation. In contrast to the effects of sensory denervation, sympathetic denervation did not alter either the acinar appearance or secretory responsiveness of the gland.

CONCLUSION

Loss of the considerable sensory innervation from the trigeminal ganglion has pronounced effects on the pharmacologic responsiveness and the structure of the lacrimal gland. The effects of sensory innervation on the gland may be mediated through two possible pathways: direct input to the gland or control of the preganglionic parasympathetic pathway.

Observation of associated near-side and away-side long-range correlations in sqrt[s(NN)]=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δø) and pseudorapidity (Δη) are measured in sqrt[s(NN)] = 5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb(-1) of data as a function of transverse momentum (p(T)) and the transverse energy (ΣE(T)(Pb)) summed over 3.1 < η < 4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2 < |Δ η | < 5) "near-side" (Δø ~ 0) correlation that grows rapidly with increasing ΣE(T)(Pb). A long-range "away-side" (Δø ~ π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣE(T)(Pb), is found to match the near-side correlation in magnitude, shape (in Δη and Δø) and ΣE(T)(Pb) dependence. The resultant Δø correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δø modulation for all ΣE(T)(Pb) ranges and particle p(T).

Alternative heterocycles for DNA recognition: an N-methylpyrazole/N-methylpyrrole pair specifies for A.T/T.A base pairs

Side-by-side pairs of three five-membered rings, N-methylpyrrole (Py), N-methylimidazole (Im), and N-methylhydroxy-pyrrole (Hp), have been demonstrated to distinguish each of the four Watson Crick base pairs in the minor groove of DNA. However, not all DNA sequences targeted by these pairing rules achieve affinities and specificities comparable to DNA binding proteins. We have initiated a search for new heterocycles which can expand the sequence repetoire currently available. Two heterocyclic aromatic amino acids. N-methylpyrazole (Pz) and 4-methylthiazole (Th), were incorporated into a single position of an eight-ring polyamide of sequence ImImXPy-gamma-lmPyPyPy-beta-Dp to examine the modulation of affinity and specificity for DNA binding by a Pz/Py pair and or a Th/Py pair. The X/Py pairings Pz/Py and Th/Py were evaluated by quantitative DNase I footprint titrations on a DNA fragment with the four sites 5'-TGGNCA-3' (N=T, A, G, C). The Pz/Py pair binds T.A and A.T with similar affinity to a Py/Py pair but with improved specificity. disfavoring both G.C and C.G by about 100-fold. The Th/Py pair binds poorly to all four Watson Crick base pairs. These results demonstrate that in some instances new heterocyclic aromatic amino acid pairs can be incorporated into imidazole-pyrrole polyamides to mimic the DNA specificity of Py/Py pairs which may be relevant as biological criteria in animal studies become important.

The clinical utility of multimarker RT-PCR in the detection of occult metastasis in patients with melanoma

Cutaneous melanoma is characterized by a high propensity for metastasis. Currently, surgical intervention remains the mainstay of therapy. This approach has proven most beneficial when the diagnosis is of early stage primary lesions. Likewise, patients undergoing resection for a solitary site of metastasis have shown a survival advantage. Identification of metastatic disease depends predominantly on radiographic techniques requiring the presence of significant tumor burdens for successful imaging. However, at that time, the role of surgery and/or biochemotherapy may be of limited value. Techniques to identify minimal disease states may permit more accurate assessment of prognosis. The detection of occult tumor cells by RT-PCR in the blood, lymph nodes, and bone marrow of melanoma patients provides one such approach to monitor tumor progression. Single-marker RT-PCR has been used as one such approach but is noted to have limitations in sensitivity and specificity based on the heterogeneity of tumor marker expression among tumors as well as within an individual tumor lesion or among multiple lesions in individual patients. We employed a multimarker reverse transcriptase polymerase chain reaction assay that demonstrates improved sensitivity over a single-marker approach. Currently, the consequences of detecting systemic subclinical metastasis remain unknown pending longer-term follow-up. The detection of occult melanoma cells using molecular techniques in conjunction with known clinicopathologic prognostic factors may provided a novel and efficient approach in monitoring tumor progression and further identify high-risk patients diagnosed early in the disease course.

Seroma prevention in a rat mastectomy model: use of a light-activated fibrin sealant

Seroma formation following mastectomy and axillary dissection remains a common and significant problem contributing to patient morbidity and health-care costs. Previous data have suggested that fibrin sealant (FS), a biological adhesive, is capable of controlling lymphatic leakage and assisting with skin graft adhesion. In this study, the use of an experimental, light-activated FS under development by CryoLife (CFS) was evaluated in a rat mastectomy model in order to reduce seroma formation. CFS is a premixed form of FS, containing an inactivator that is reversed in the presence of light, causing sealant to form. In this model, rats underwent mastectomy and extensive dissection of the axillary lymphovasculature. Next, 1 ml of saline or FS was applied to the operative site and the wound was closed. Three groups of animals were evaluated 5 days postoperatively by measuring the volume (in milliliters) of seroma able to be aspirated from the surgical site. The saline control group (N = 20) had a seroma volume (mean +/- standard deviation [SD]) of 4.2 +/- 2.9 ml, while a form of CFS containing human fibrinogen (80 to 100 mg per milliliter) and human thrombin (20 U per milliliter) (N = 20) had a significantly smaller seroma volume of 1.1 +/- 1.6 ml (p < 0.001 analysis of variance). University of Virginia (UVA) FS, containing human fibrinogen (20 mg per milliliter) and bovine thrombin (500 U per milliliter) (N = 20), had a seroma volume of 2.0 +/- 1.6 ml (p < 0.01, compared to control; p > 0.2, compared to CFS). Thus, this form of CFS significantly reduced seroma formation compared to saline control and also appeared to result in a smaller fluid accumulation than with UVA FS, although this trend was not statistically significant. These data suggest that the use of CFS may help to reduce seroma formation in humans.

Measurement of the Inelastic Proton-Proton Cross Section at sqrt[s]=13 TeV with the ATLAS Detector at the LHC

This Letter presents a measurement of the inelastic proton-proton cross section using 60  μb^{-1} of pp collisions at a center-of-mass energy sqrt[s] of 13 TeV with the ATLAS detector at the LHC. Inelastic interactions are selected using rings of plastic scintillators in the forward region (2.07<|η|<3.86) of the detector. A cross section of 68.1±1.4  mb is measured in the fiducial region ξ=M_{X}^{2}/s>10^{-6}, where M_{X} is the larger invariant mass of the two hadronic systems separated by the largest rapidity gap in the event. In this ξ range the scintillators are highly efficient. For diffractive events this corresponds to cases where at least one proton dissociates to a system with M_{X}>13  GeV. The measured cross section is compared with a range of theoretical predictions. When extrapolated to the full phase space, a cross section of 78.1±2.9  mb is measured, consistent with the inelastic cross section increasing with center-of-mass energy.