Laparoscopic Heller Myotomy With EGD and Balloon Dilation: A Durable Solution for Achalasia

BACKGROUND

Laparoscopic Heller myotomy (LHM) and esophageal balloon dilation (BD) are the two mainstays of achalasia treatment-this study examines the outcomes when they are performed simultaneously without fundoplication.

METHODS

All patients undergoing LHM&BD were reviewed for demographic and procedural data, and to see if additional procedures for achalasia had been performed. Patients were surveyed using the Eckardt score and the GERD quality-of-life score (GERD-HRQL) to assess the durability of repair.

RESULTS

From 2013-2020, 66 patients underwent LHM&BD. There were no esophageal perforations and a median LOS of 1 day. Seven patients have required additional operations or procedures at median 4-years follow up. 31 patients (47%) responded to the survey. The average Eckardt score was 2.9 (goal<4) with mean GERD-HRQL of 14.4 (goal<25).

CONCLUSIONS

LHM&BD allows for a safe, durable repair of achalasia. Reflux symptoms are manageable with PPI without fundoplication and the re-intervention rate similar to published values.

Biomechanical Comparison of Fibrin Sealants for Mesh Fixation

Adhesive use for fixation in hernia repair allows for complete and immediate mesh surface area adherence. Little is known about the fixation strengths of the products and application methods available. The purpose of this study was to compare the immediate and early strength of fixation of Tisseel™ and Evicel™ using hand and spray application techniques. Sixteen Mongrel swine underwent implantation of large-pore, mid-weight polypropylene mesh fixated with either Tisseel™ or Evicel™, applied by hand or with a spray apparatus. Time points studied were zero and four days. All samples underwent lap shear testing to quantify the strength of the mesh-tissue interface as an indicator of mesh fixation strength. Thirty Day 4 and 16 Day 0 samples were tested. Manually applied Tisseel™ mean fixation strength was 2.05 N/cm at Day 0 and 6.02 N/cm at Day 4. Sprayed Tisseel™ had mean fixation strength of 1.22 N/cm at Day 0 and 7.21 N/cm at Day 4. Manually applied Evicel™ showed mean fixation strength of 0.92 N/cm at Day 0 and 6.73 N/cm at Day 4. Mean fixation strength of sprayed Evicel™ was 0.72 N/cm at Day 0 and 6.70 N/cm at Day 4. Analysis of variance showed no difference between groups at Day 0 or Day 4. Immediate strength of mesh fixation could have significant implications for early recurrence and mesh contraction. This study demonstrates that no difference exists in immediate or early fixation strength between these two brands of sealants or their method of application.

Biomechanical Comparison of Fibrin Sealants for Mesh Fixation

Adhesive use for fixation in hernia repair allows for complete and immediate mesh surface area adherence. Little is known about the fixation strengths of the products and application methods available. The purpose of this study was to compare the immediate and early strength of fixation of Tisseel™ and Evicel™ using hand and spray application techniques. Sixteen Mongrel swine underwent implantation of large-pore, mid-weight polypropylene mesh fixated with either Tisseel™ or Evicel™, applied by hand or with a spray apparatus. Time points studied were zero and four days. All samples underwent lap shear testing to quantify the strength of the mesh–tissue interface as an indicator of mesh fixation strength. Thirty Day 4 and 16 Day 0 samples were tested. Manually applied Tisseel™ mean fixation strength was 2.05 N/cm at Day 0 and 6.02 N/cm at Day 4. Sprayed Tisseel™ had mean fixation strength of 1.22 N/cm at Day 0 and 7.21 N/cm at Day 4. Manually applied Evicel™ showed mean fixation strength of 0.92 N/cm at Day 0 and 6.73 N/cm at Day 4. Mean fixation strength of sprayed Evicel™ was 0.72 N/cm at Day 0 and 6.70 N/cm at Day 4. Analysis of variance showed no difference between groups at Day 0 or Day 4. Immediate strength of mesh fixation could have significant implications for early recurrence and mesh contraction. This study demonstrates that no difference exists in immediate or early fixation strength between these two brands of sealants or their method of application.

Biomechanical and Histologic Evaluation of LifeMesh™: A Novel Self-Fixating Mesh Adhesive

Mesh fixation with the use of adhesives results in an immediate and total surface area adhesion of the mesh, removing the need for penetrating fixation points. The purpose of this study was to evaluate LifeMesh™, a prototype mesh adhesive technology which coats polypropylene mesh. The strength of the interface between mesh and tissue, inflammatory responses, and histology were measured at varying time points in a swine model, and these results were compared with sutures. Twenty Mongrel swine underwent implantation of LifeMesh™ and one piece of bare polypropylene mesh secured with suture (control). One additional piece of either LifeMesh™ or control was used for histopathologic evaluation. The implants were retrieved at 3, 7, and 14 days. Only 3- and 7-day specimens underwent lap shear testing. On Day 3, LifeMesh™ samples showed considerably less contraction than sutured samples. The interfacial strength of Day 3 LifeMesh™ samples was similar to that of sutured samples. At seven days, LifeMesh™ samples continued to show significantly less contraction than sutured samples. The strength of fixation at seven days was greater in the control samples. The histologic findings were similar in LifeMesh™ and control samples. LifeMesh™ showed significantly less contraction than sutured samples at all measured time points. Although fixation strength was similar at three days, the interfacial strength of LifeMesh™ remained unchanged, whereas sutured controls increased by day 7. With histologic equivalence, considerably less contraction, and similar early fixation strength, LifeMesh™ is a viable mesh fixation technology.

Biomechanical and Histologic Evaluation of LifeMesh™: A Novel Self-Fixating Mesh Adhesive

Mesh fixation with the use of adhesives results in an immediate and total surface area adhesion of the mesh, removing the need for penetrating fixation points. The purpose of this study was to evaluate LifeMesh™, a prototype mesh adhesive technology which coats polypropylene mesh. The strength of the interface between mesh and tissue, inflammatory responses, and histology were measured at varying time points in a swine model, and these results were compared with sutures. Twenty Mongrel swine underwent implantation of LifeMesh™ and one piece of bare polypropylene mesh secured with suture (control). One additional piece of either LifeMesh™ or control was used for histopathologic evaluation. The implants were retrieved at 3, 7, and 14 days. Only 3- and 7-day specimens underwent lap shear testing. On Day 3, LifeMesh™ samples showed considerably less contraction than sutured samples. The interfacial strength of Day 3 LifeMesh™ samples was similar to that of sutured samples. At seven days, LifeMesh™ samples continued to show significantly less contraction than sutured samples. The strength of fixation at seven days was greater in the control samples. The histologic findings were similar in LifeMesh™ and control samples. LifeMesh™ showed significantly less contraction than sutured samples at all measured time points. Although fixation strength was similar at three days, the interfacial strength of LifeMesh™ remained unchanged, whereas sutured controls increased by day 7. With histologic equivalence, considerably less contraction, and similar early fixation strength, LifeMesh™ is a viable mesh fixation technology.

Migrated embolization coil causes intestinal obstruction

Visceral artery pseudoaneurysm is a rare, potentially fatal entity, but proper identification and management with coil embolization can lead to good outcomes. Embolization coils can migrate to various destinations, causing delayed complications in several case reports. A case of small bowel obstruction due to migrated embolization coils from a gastroduodenal pseudoaneurysm 6 years after initial treatment is presented.

Fibrin Sealant: A Review of the History, Biomechanics, and Current Applications for Prosthetic Fixation in Hernia Repair

The role of surgical adhesives in hernia repair has continued to evolve. The purpose of this chapter is to review the role of fibrin sealant and its application in general surgery for mesh fixation, specifically the history, biomechanics, and clinical utilization. The utilization of fibrin sealant for repair of groin hernias, both open and laparoscopic, ventral hernias, and hiatal hernias will be discussed.

The effects of aerobic exercise intensity and duration on levels of brain-derived neurotrophic factor in healthy men

This study examined the combined effects of aerobic exercise intensity and duration on serum brain-derived neurotrophic factor (sBDNF) levels in healthy human adult males aged 18-25 years. Forty five participants were randomly assigned to one of six exercise conditions based on varying intensity (80% or 60% of heart rate reserve, or control) and duration (20 or 40 min). Vigorous (80% heart rate reserve, "Vig") and moderate (60% heart rate reserve, "Mod") exercise was carried out on cycle ergometers. Control subjects remained seated and at rest during the exercise period. Pre- and post-exercise blood draws were conducted and sBDNF measured. Physical exercise caused an average ~ 32% increase in sBDNF levels relative to baseline that resulted in concentrations that were 45% higher than control conditions. Comparing the six conditions, sBDNF levels rose consistently among the four exercise conditions (Vig20 = 26.38 ± 34.89%, Vig40 = 28.48 ± 19.11%, Mod20 = 41.23 ± 59.65%, Mod40 = 30.16 ± 72.11%) and decreased consistently among the controls (Con20 = -14.48 ± 16.50, Con40 = -10.51 ± 26.78). Vig conditions had the highest proportion of subjects that experienced a significant (? 10%) increase in sBDNF levels, followed by Mod and control conditions. An analysis of modeled sBDNF integrals (area under the curve) demonstrated substantially greater values for Vig40 and Mod40 conditions compared to Vig20 and Mod20 conditions. Collectively, these results demonstrate that neither duration (20 vs. 40 min) nor intensity (60 vs. 80% HR reserve) significantly affects the benefits of exercise if only the sBDNF increase at a single post-exercise time point is considered. However, when comparing either the probability of achieving a significant BDNF gain or the integral (i.e. the volume of circulating BDNF over time) the Vig40 condition offers maximal benefits. Thus, we conclude that the future study of aerobic exercise effects on BDNF-mediated neuroprotection should take the volume of BDNF release over time into account. Key PointsAerobic exercise caused a ~32% increase in serum BDNF in adult human males while serum BDNF decreased 13% in sedentary control subjects.Vigorous intensity (80% heart rate reserve), long duration (40 min) exercise offered the greatest probability of a significant BDNF elevation.Long duration exercise offered the greatest numerical benefits in terms of BDNF integral.Neither intensity nor duration affected the mean elevation in BDNF amplitude caused by exercise.

Admission ionized calcium levels predict the need for multiple transfusions: a prospective study of 591 critically ill trauma patients

BACKGROUND

Deaths from uncontrolled exsanguinating hemorrhage occur rapidly postinjury. Any successful resuscitation strategy must also occur early, underscoring the importance of rapid identification of patients at risk for multiple transfusions. Previous studies have shown low ionized calcium (iCa) levels to be associated with hypotension and function as a predictor of mortality. We hypothesized that admission iCa levels could potentially predict the need for multiple transfusions in critically ill trauma patients.

METHODS

Admission iCa was collected prospectively on all trauma activations during a 9-month period. Youden's index was used to determine the appropriate cutpoint for iCa. Outcomes (mortality, multiple transfusions [≥5 units packed red blood cells in 24 hours] and massive transfusion [≥10 units packed red blood cells in 24 hours]) were compared using Wilcoxon rank-sum and χ tests where appropriate. Multivariable logistic regression was performed to determine whether iCa was an independent predictor of multiple transfusions.

RESULTS

A total of 591 patients were identified: 461 (78%) men and 130 (22%) women. Cutpoint was identified as 1.00. iCa was <1.00 (lo-Cal) in 332 patients and≥1.00 (hi-Cal) in 259 patients. Mortality was significantly increased in the lo-Cal group (15.5% vs. 8.7%, p=0.036). In addition, both multiple transfusions (17.1% vs. 7.1%, p=0.005) and massive transfusion (8.2% vs. 2.2%, p=0.017) were significantly increased in the lo-Cal group. Multivariable logistic regression analysis identified iCa<1 as an independent predictor of the need for multiple transfusions after adjusting for age and injury severity (odds ratio=2.294, 95% confidence interval=1.053-4.996).

CONCLUSIONS

Low iCa levels at admission were associated with increased mortality as well as an increased need for both multiple transfusions and massive transfusion. In fact, multivariable logistic regression analysis identified low iCa levels as an independent predictor of multiple transfusions. Admission iCa levels may facilitate the rapid identification of patients requiring massive transfusion, allowing for earlier preparation and administration of appropriate blood products.

Comparison of a real-time reverse transcriptase PCR assay and a culture technique for quantitative assessment of viral load in children naturally infected with respiratory syncytial virus

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory infection of children. Understanding RSV pathogenesis and evaluating interventions requires quantitative RSV testing. Previous studies have used the plaque assay technique. Real-time reverse transcriptase PCR (RTrtPCR) offers possible greater sensitivity, stability after freeze/thaw, and lower cost, thus facilitating multicenter studies. We developed RTrtPCR assays based upon the RSV N and F genes. The N-gene assay detected greater RSV quantity and was further evaluated. Standard curves utilized both extractions from RSV culture supernatants of known quantity and cloned purified copies of the target DNA. In vitro, the ratio of RSV subgroup A (RSV-A) genome copies to PFU was 153:1. A total of 462 samples collected quantitatively from 259 children were analyzed in duplicate by RTrtPCR. Results were compared with those of RSV plaque assays performed on fresh aliquots from the same children. Duplicate RTrtPCR results were highly correlated (r2 = 0.9964). The mean viral load from nasal washes obtained on the first study day was 5.75 +/- standard error of the mean 0.09 log PFU equivalents (PFUe)/ml. Viral load by RTrtPCR correlated with plaque assay results (r2 = 0.158; P < 0.0001). Within individuals, upper and lower respiratory tract secretions contained similar viral concentrations. RSV-A-infected children had 1.17 log PFUe higher viral loads than did those with RSV-B (P < 0.0001). RSV quantification by RTrtPCR of the N gene is precise and has significant, though limited, correlation with quantitative culture. The utility of the RTrtPCR quantification technique for clinical studies would be solidified after its correlation with RSV disease severity is established.

Heme oxygenase-1 messenger RNA expression is induced in peripheral blood mononuclear cells of pediatric cancer patients with systemic inflammatory response syndrome

OBJECTIVE

To determine whether heme oxygenase-1 messenger RNA expression in peripheral blood mononuclear cells is induced in pediatric cancer patients with the systemic inflammatory response syndrome (SIRS) and whether this expression correlates with the heme oxygenase-1 products, bilirubin and carboxyhemoglobin.

DESIGN

Prospective, controlled study.

SETTING

A tertiary care pediatric oncology hospital.

PATIENTS

Fourteen patients admitted to the intensive care unit with a diagnosis of SIRS by American College of Chest Physicians/Society for Critical Care Medicine consensus criteria and 17 control patients (off therapy, no acute illness).

INTERVENTIONS

Blood for bilirubin, carboxyhemoglobin, and heme oxygenase-1 messenger RNA expression was collected at study entry. SIRS patients continued to have samples collected every 12 hrs for 1 wk or until intensive care unit discharge. Heme oxygenase-1, bilirubin, and carboxyhemoglobin levels of SIRS patients were compared with controls, and correlation between heme oxygenase-1 and products was assessed.

MEASUREMENTS AND MAIN RESULTS

Within 48 hrs of study entry, maximum heme oxygenase-1 expression for all SIRS patients compared with controls was 5.5 +/- 1.0 vs. 1.1 +/- 0.1 (p < .0006). Maximum expression was > or =2.3-fold in 13 of 14 SIRS patients. Maximum heme oxygenase-1 expression also differed from minimum (5.5 +/- 1.0 vs. 1.6 +/- 0.3, p < .003). Maximum bilirubin and carboxyhemoglobin levels within 48 hrs of study entry differed between SIRS patients and controls (3.0 +/- 0.8 vs. 0.3 +/- 0.1, p = .006; and 1.2 +/- 0.2 vs. 0.6 +/- 0.1, p = .001, respectively). Bilirubin, but not carboxyhemoglobin, correlated with heme oxygenase-1 expression (p = .0013).

CONCLUSIONS

Heme oxygenase-1 messenger RNA, bilirubin, and carboxyhemoglobin levels were increased within 48 hrs of admission in pediatric cancer patients with SIRS. Heme oxygenase-1 expression correlated with serum bilirubin levels. The increase in heme oxygenase-1 expression may add to the understanding of the increase in serum bilirubin observed in patients with SIRS/sepsis. These findings support a role for heme oxygenase-1 in the physiologic response to inflammatory stress.

Cyclin-dependent kinase 5 promotes insulin exocytosis

Cyclin-dependent kinase 5 (Cdk5) is widely expressed although kinase activity has been described preferentially in neuronal systems. Cdk5 has an impact on actin polymerization during neuronal migration and neurite outgrowth and deregulation of the kinase has been implicated in the promotion of neurodegeneration. Recently it was shown that Cdk5 modulates dopamine signaling in neurons by regulating DARPP-32 function. In addition, Cdk5 phosphorylates munc-18 and synapsin I, two essential components of the exocytotic machinery. We have shown by reverse transcriptase-polymerase chain reaction, immunocytochemistry, and Western blotting that Cdk5 is present in the insulin-secreting pancreatic beta-cell. Subcellular fractionation of isolated beta-cells revealed a glucose-induced translocation of membrane-bound Cdk5 protein to lower density fractions. Inhibition of Cdk5 with roscovitine reduced insulin secretion with approximately 35% compared with control after glucose stimulation and with approximately 65% after depolarization with glucose and KCl. Capacitance measurements performed on single beta-cells that expressed a dominant-negative Cdk5 mutant showed impaired exocytosis. The effect on exocytosis by Cdk5 appeared to be independent of changes in free cytoplasmic Ca(2+) concentration. Taken together these results show that Cdk5 is present in beta-cells and acts as a positive regulator of insulin exocytosis.

Insulin exocytosis and glucose-mediated increase in cytoplasmic free Ca2+ concentration in the pancreatic beta-cell are independent of cyclic ADP-ribose

Stimulation of pancreatic beta-cells by glucose gives rise to an increase in the cytoplasmic free calcium concentration ([Ca2+]i) and exocytosis of insulin. Cyclic adenosine 5'-diphosphate ribose (cADPR), a metabolite of beta-NAD+, has been reported to increase [Ca2+]i in pancreatic beta-cells by releasing Ca2+ from inositol 1,4,5-trisphosphate-insensitive intracellular stores. In the present study, we have examined the role of cADPR in glucose-mediated increases in [Ca2+]i and insulin exocytosis. Dispersed ob/ob mouse beta-cell aggregates were either pressure microinjected with fura-2 salt or loaded with fura-2 acetoxymethyl ester, and [Ca2+]i was monitored by microfluorimetry. Microinjection of beta-NAD+ into fura-2-loaded beta-cells did not increase [Ca2+]i nor did it alter the cells' subsequent [Ca2+]i response to glucose. Cells microinjected with the cADPR antagonist 8NH2-cADPR increased [Ca2+]i in response to glucose equally well as those injected with cADPR. Finally, the ability of cADPR to promote exocytosis of insulin in electropermeabilized beta-cells was investigated. cADPR on its own did not increase insulin secretion nor did it potentiate Ca2+-induced insulin secretion. We conclude that cADPR neither plays a significant role in glucose-mediated increases in [Ca2+]i nor interacts directly with the molecular mechanisms regulating exocytosis of insulin in normal pancreatic beta-cells.

Induction of mouse beta integrin expression following transfection with human alpha 4 chain

We report here an analysis of the expression and function of the alpha chain of human VLA-4 in stable mouse L cell transfectants and the requirement for the beta chain in these processes. L cells were transfected with human alpha 4 cDNA or alpha 4 and human beta 1 cDNA. Unexpectedly, human alpha 4 cDNA, when transfected alone, could induce de novo surface expression of host beta 7 and increased expression of host beta 1. Induction of mouse beta 7 and beta 1 surface expression was not due to de novo gene activation, but instead represented alpha 4/beta intracellular subunit association and transport to the cell surface. Transfection with human beta 1 prevented surface expression of mouse beta integrins. Whereas human alpha 4 and human beta 1 subunits associated very tightly in anti-alpha 4 immunoprecipitates, human alpha 4 and mouse beta subunits were only partially associated. Furthermore, binding of human/mouse chimeric receptors to recombinant VCAM, a major ligand for alpha 4 beta 7 and alpha 4 beta 1, was very poor, whereas human alpha 4/human beta 1 receptors bound strongly to VCAM. One alpha 4 transfectant, which exhibited a tight human alpha 4/mouse beta 1 association, could be induced, but only after PMA activation, to bind strongly to VCAM. These results indicate that alpha 4 subunits have specific affinity for beta 7 and beta 1 integrins and require beta subunits for surface expression as well as high affinity ligand binding activity. Our results indicate that a tight association between the alpha 4 and beta subunit appears to be critical for ligand binding, consistent with a direct as well as regulatory role for the beta subunit in ligand binding. Furthermore, these studies demonstrate that expression of foreign recombinant proteins can alter host cell protein expression resulting in de novo surface protein expression.

Aspartate 698 within a novel cation binding motif in alpha 4 integrin is required for cell adhesion

The interactions of alpha 4 beta 1 integrin with vascular cell adhesion molecule (VCAM) and fibronectin play important roles in many physiological and pathological processes. To understand the mechanism of alpha 4 beta 1 integrin-mediated cell adhesion, we made mutant alpha 4 constructs. Three aspartic acid (Asp) residues in alpha 4, Asp-489, Asp-698, and Asp-811, were replaced with glutamic acids (Glu). The wild-type and mutant alpha 4 constructs were transfected into K562 cells, and stable transfectants with similar levels of alpha 4 surface expression were established. The Asp-->Glu substitutions did not affect alpha 4 beta 1 association or heterodimer formation as demonstrated by immunoprecipitation analysis. However, the glutamate substitutions at Asp-489 and Asp-698 severely impaired cell adhesion to VCAM and fibronectin, whereas the substitution at Asp-811 had no detectable effect on cell adhesion. In contrast to these results, isolated alpha 4 beta 1, containing the D489E or D698E substitution, was able to bind to VCAM, suggesting that these two residues are not critical for ligand recognition. In searching for a mechanism to explain inhibition of adhesion by Asp-489 and Asp-698 mutations, we found that the sequences flanking Asp-698 resemble the DxxxxxD-S-Sx divalent cation/ligand binding motif in beta integrins and the I-domains of alpha integrins. This suggests that Asp-698 in the alpha 4 integrin, which does not possess an I-domain, may also be involved in cation binding and may be part of a sequence functionally similar to that found in the I-domains of other alpha integrins.

Two separate plasma membrane Ca2+ carriers participate in receptor-mediated Ca2+ influx in rat hepatocytes

The plasma membrane Ca2+ carrier system involved in receptor-mediated Ca2+ entry was studied. Using the Ca2+ readdition protocol, the rate of cytosolic free Ca2+ concentration ([Ca2+]i) increase in vasopressin-pretreated hepatocytes was significantly higher than in thapsigargin- or 2,5-di(tert-butyl)hydroquinone-pretreated cells. The addition of Mn2+ to unstimulated hepatocytes resulted in a biphasic quench of fura-2 fluorescence. After an initial phase that was fast in rate but of short duration, the rate of fura-2 quench by Mn2+ became much slower and lasted until all the cellular fura-2 was quenched. Pretreatment of the cells with vasopressin only accelerated the rate of the latter phase but not of the initial one. In agonist-stimulated cells, acidification of the extracellular medium or the presence of ruthenium red, econazole or SK&F 96365 decreased the rates of both [Ca2+]i increase and Mn2+ entry upon addition of the respective cation. By contrast, neomycin and N-tosyl-L-phenylalanine chloromethyl ketone markedly decreased the rate of [Ca2+]i increase upon Ca2+ readdition but had no effect on vasopressin-stimulated Mn2+ entry. None of the treatments affected the ability of vasopressin and thapsigargin to mobilize the internal Ca2+ store. It is concluded that in hepatocytes the two pathways of receptor-mediated Ca2+ entry control two distinct yet pharmacologically related cation carriers.

Receptor-mediated Mn2+ influx in rat hepatocytes: comparison of cells loaded with Fura-2 ester and cells microinjected with Fura-2 salt

In single Fura-2 ester-loaded hepatocytes, stimulation by vasopressin, but not emptying of the agonist-sensitive Ca2+ store by 2,5-di-(t-butyl)hydroquinone, resulted in an increase in the rate of Fura-2 fluorescence-quenching by Mn2+. Similarly, in cells microinjected with Fura-2 salt, vasopressin stimulated Mn2+ entry while 2,5-di-(t-butyl)hydroquinone or thapsigargin did not. The pattern of Fura-2 quenching by Mn2+ only correlated with the movement of Mn2+ across the plasma membrane.

Role of third N-terminal domain of VCAM-1

The interaction between VLA-4 and VCAM-1 has been implicated in the recruitment, adhesion, and activation of mononuclear leukocytes in chronic inflammatory conditions and autoimmune disease. The seven domain extracellular portion of VCAM-1, sVCAM1-7, and the first three and two N-terminal domains of VCAM-1, sVCAM1-3 and sVCAM1-2, respectively, were expressed in baculovirus and purified. Using these purified soluble forms of VCAM-1 and cellular transfectants expressing various cell bound forms of VCAM-1, we show that the major binding site for VLA-4 is located within the first two domains of VCAM-1 and that the third domain of VCAM-1 appears to be required for functional integrity of the VLA-4 binding site.

Cell contact between T cells and synovial fibroblasts causes induction of adhesion molecules and cytokines

Human activated T cells adhere to synovial fibroblast-like cells in vitro. The present study was conducted to investigate the consequences of T cell-synovial fibroblast interactions with regard to induction of adhesion molecules and proinflammatory cytokines. A sensitive Western blot technique, polymerase chain reaction (PCR) amplification, and fluorescence-activated cell sorter (FACS) analysis were used to analyze the induction of VCAM-1 and ICAM-1 expression in T cell-synovial fibroblast cocultures. VCAM-1 and ICAM-1 expression could be induced in synovial fibroblast-like cells by 2 h. PCR amplification showed that both forms of VCAM-1 mRNA are found after the interaction of synovial fibroblasts with T cells. Up-regulation of VCAM-1 and ICAM-1 was confined to synovial fibroblasts; T cells did not express VCAM-1 or increased ICAM-1. In contrast to the T cell-synoviocyte interaction, the interaction between T cells and dermal fibroblasts resulted in the up-regulation of ICAM-1 but not VCAM-1, suggesting tissue-specific regulation of VCAM-1. The T cell-synovial fibroblast interaction also resulted in increased levels of tumor necrosis factor (TNF), interferon-gamma, and interleukin-6 in coculture supernatant. Of the neutralizing antibodies used against these cytokines, only anti-TNF could significantly inhibit VCAM-1 and ICAM-1 expression. When T cells were separated from synoviocytes by a chamber that allowed medium exchange but no cell contact, VCAM-1 and ICAM-1 failed to be up-regulated and cytokine accumulation in cocultures was drastically reduced. Our results demonstrate mutual cell activation of T cells and synoviocytes upon cell contact as shown by the release of T cell- and synoviocyte-specific cytokines and suggest a cell contact-mediated and T cell-initiated mechanism for the chronic accumulation and retention of mononuclear cells via VCAM-1/ICAM-1 by synovial fibroblasts in the rheumatoid synovium.

Interacting monocytes and synoviocytes induce adhesion molecules by a cytokine-regulated process

Monocytes/macrophages and synovial fibroblast-like cells are in intimate contact in the synovium and are believed to play a critical role in the development of rheumatoid arthritis. We investigated the effects of monocyte-synoviocyte interactions in vitro on cytokine release and the expression of adhesion molecules. Using a sensitive Western blot assay, we found that VCAM-1 and ICAM-1 expression were up-regulated in synoviocytes following coculture. The interaction also resulted in the accumulation of TNF and IL-6, but not IFN-gamma in the culture medium. Culture supernatant from monocyte-synoviocyte samples effectively induced adhesion molecules in synoviocytes. Anti-TNF partially inhibited the increase in VCAM-1 and ICAM-1 expression, indicating that TNF in part mediates VCAM-1 and ICAM-1 expression. Interestingly, the induction of cytokines and adhesion molecules did not require cell contact between monocytes and synoviocytes, suggesting cell communication via soluble factors. T cell cytokines enhanced the induction of adhesion molecules induced by the monocyte-synoviocyte interaction. IFN-gamma and IL-4, which are produced by distinct T helper subsets, had differential effects on monocyte-synoviocyte interactions. IFN-gamma had a minimal effect on VCAM-1 expression by synovial fibroblasts, but synergized with monocytes to dramatically up-regulate ICAM-1 expression. IL-4 had no effect on ICAM-1 expression but enhanced monocyte-induced expression of VCAM-1. Our results demonstrate that the up-regulation of adhesion molecules following monocyte-synoviocyte interactions is mediated by soluble factors and can be regulated by specific T cell cytokines.

Head and Neck Malignant Fibrous Histiocytomas

Malignant fibrous histiocytoma of the head and neck is a rare tumor with less than 50 total cases reported in the literature. Its rarity and complex histopathology combine to make it a difficult diagnosis. Two cases are described. Pathology characteristics are discussed. The traditional treatment of choice is wide surgical excision. Radiation therapy is usually reserved for recurrent, unresectable, or extremely aggressive tumors.

Head and neck malignant fibrous histiocytomas

Malignant fibrous histiocytoma of the head and neck is a rare tumor with less than 50 total cases reported in the literature. Its rarity and complex histopathology combine to make it a difficult diagnosis. Two cases are described. Pathology characteristics are discussed. The traditional treatment of choice is wide surgical excision. Radiation therapy is usually reserved for recurrent, unresectable, or extremely aggressive tumors.

Expression of vascular cell adhesion molecule-1 in fibroblastlike synoviocytes after stimulation with tumor necrosis factor

Rapid expression of mRNA encoding vascular cell adhesion molecule-1 (VCAM-1) was induced by tumor necrosis factor (TNF) in fibroblast-like cells obtained from synovial tissue. Both alternatively spliced forms of VCAM-1 mRNA were detected by polymerase chain reaction in TNF-stimulated fibroblast-like synoviocytes. Western blotting analysis showed that two distinct proteins, reactive with an anti-VCAM-1 anti-sera, were expressed by 2 hours of TNF stimulation in both synoviocytes and human umbilical cord vein endothelial cells (HUVEC). The majority of HUVEC and synoviocytes displayed VCAM-1 surface expression after several hours of TNF stimulation. In contrast, dermal fibroblasts upregulated intercellular adhesion molecule-1 (ICAM-1) but not VCAM-1 expression in response to TNF. These results indicate that VCAM-1 and ICAM-1 expression can be differentially regulated and suggest tissue specific regulation of VCAM-1 expression. Furthermore, these findings may provide an explanation for the chronic retention and activation of long-lived lymphocytes and monocytes, which express VLA-4 (the receptor for VCAM-1), in the synovium in rheumatoid arthritis.

Effects of diltiazem on complications and restenosis after coronary angioplasty

A randomized, placebo-controlled, double-blinded trial was performed to evaluate the usefulness of empiric therapy with a calcium antagonist in patients who undergo coronary angioplasty. A total of 201 patients were randomized to placebo or to high-dose diltiazem (mean dose, 329 mg/day). Treatment began 24 hours before angioplasty. Restenosis was assessed by percent area stenosis as determined by quantitative angiographic techniques before, immediately and 1 year after angioplasty. All patients also received aspirin and dipyridamole before angioplasty. Heparin and verapamil were administered intravenously during the procedure. The 2 groups were similar with respect to age, extent of coronary artery disease, smoking history, and baseline lipid levels. Procedural complications, including death (1 vs 1), Q-wave infarction (0 vs 3), acute occlusion (5 vs 5) and focal spasm (0 vs 0), were not significantly different in the diltiazem and placebo patients, respectively. Freedom from all acute complications was noted in 85% of patients in both groups. One-year angiographic follow-up was obtained in 60% of patients. Restenosis rates were similar: 36% in the diltiazem group and 32% in the placebo group (p = 0.30). The incidence of late cardiac events (death, Q-wave myocardial infarction, recurrent angina or coronary bypass graft surgery) was similar in the 2 groups. Thus, diltiazem did not influence the overall restenosis rate or prevent late events after coronary angioplasty.