bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacologic ascorbic acid concentrations selectively kill cancer cells: Action as a pro-drug to deliver hydrogen peroxide to tissues
Authors: Chen Qi , Espey Michael Graham , Krishna Murali C. , Mitchell James B. , Corpe Christopher P. , Buettner Garry R. , Shacter Emily , Levine Mark
Published: September 2005

Human pharmacokinetics data indicate that i.v. ascorbic acid (ascorbate) in pharmacologic concentrations could have an unanticipated role in cancer treatment. Our goals here were to test whether ascorbate killed cancer cells selectively, and if so, to determine mechanisms, using clinically relevant conditions. Cell death in 10 cancer and 4 normal cell types was measured by using 1-h exposures. Normal cells were unaffected by 20 mM ascorbate, whereas 5 cancer lines had EC
50
values of <4 mM, a concentration easily achievable i.v. Human lymphoma cells were studied in detail because of their sensitivity to ascorbate (EC
50
of 0.5 mM) and suitability for addressing mechanisms. Extracellular but not intracellular ascorbate mediated cell death, which occurred by apoptosis and pyknosis/necrosis. Cell death was independent of metal chelators and absolutely dependent on H
2
O
2
formation. Cell death from H
2
O
2
added to cells was identical to that found when H
2
O
2
was generated by ascorbate treatment. H
2
O
2
generation was dependent on ascorbate concentration, incubation time, and the presence of 0.5-10% serum, and displayed a linear relationship with ascorbate radical formation. Although ascorbate addition to medium generated H
2
O
2
, ascorbate addition to blood generated no detectable H
2
O
2
and only trace detectable ascorbate radical. Taken together, these data indicate that ascorbate at concentrations achieved only by i.v. administration may be a pro-drug for formation of H
2
O
2
, and that blood can be a delivery system of the pro-drug to tissues. These findings give plausibility to i.v. ascorbic acid in cancer treatment, and have unexpected implications for treatment of infections where H
2
O
2
may be beneficial.
Increased salinization of fresh water in the northeastern United States
Authors: Kaushal Sujay S. , Groffman Peter M. , Likens Gene E. , Belt Kenneth T. , Stack William P. , Kelly Victoria R. , Band Lawrence E. , Fisher Gary T.
Published: September 2005

Chloride concentrations are increasing at a rate that threatens the availability of fresh water in the northeastern United States. Increases in roadways and deicer use are now salinizing fresh waters, degrading habitat for aquatic organisms, and impacting large supplies of drinking water for humans throughout the region. We observed chloride concentrations of up to 25% of the concentration of seawater in streams of Maryland, New York, and New Hampshire during winters, and chloride concentrations remaining up to 100 times greater than unimpacted forest streams during summers. Mean annual chloride concentration increased as a function of impervious surface and exceeded tolerance for freshwater life in suburban and urban watersheds. Our analysis shows that if salinity were to continue to increase at its present rate due to changes in impervious surface coverage and current management practices, many surface waters in the northeastern United States would not be potable for human consumption and would become toxic to freshwater life within the next century.
Crystal structure of a bacterial ribonuclease P RNA
Authors: Kazantsev Alexei V. , Krivenko Angelika A. , Harrington Daniel J. , Holbrook Stephen R. , Adams Paul D. , Pace Norman R.
Published: September 2005

The x-ray crystal structure of a 417-nt ribonuclease P RNA from
Bacillus stearothermophilus
was solved to 3.3-Å resolution. This RNA enzyme is constructed from a number of coaxially stacked helical domains joined together by local and long-range interactions. These helical domains are arranged to form a remarkably flat surface, which is implicated by a wealth of biochemical data in the binding and cleavage of the precursors of transfer RNA substrate. Previous photoaffinity crosslinking data are used to position the substrate on the crystal structure and to identify the chemically active site of the ribozyme. This site is located in a highly conserved core structure formed by intricately interlaced long-range interactions between interhelical sequences.
Caspase-8 deficiency in T cells leads to a lethal lymphoinfiltrative immune disorder
Authors: Salmena Leonardo , Hakem Razqallah
Published: September 2005

Caspase-8 is best known for its cell death function via death receptors. Recent evidence indicates that caspase-8 also has nonapoptotic functions. Caspase-8 deficiency is associated with pathologies that are unexpected for a proapoptotic molecule, such as abrogation of activation-induced lymphocyte proliferation, perturbed immune homeostasis, and immunodeficiency. In this study, we report the long-term physiological consequences of T cell–specific deletion of caspase-8 (tcasp8−/−). We show that tcasp8−/− mice develop an age-dependent lethal lymphoproliferative and lymphoinfiltrative immune disorder characterized by lymphoadenopathy, splenomegaly, and accumulation of T cell infiltrates in the lungs, liver, and kidneys. Peripheral casp8−/− T cells manifest activation marker up-regulation and are proliferating in the absence of any infection or stimulation. We also provide evidence suggesting that this immune disorder is different from the autoimmune lymphoproliferative syndrome. Interestingly, the condition described in tcasp8−/− mice manifests features consistent with the disorder described in humans with Caspase-8 deficiency. These findings suggest that tcasp8−/− mice may serve as an animal model to evaluate Caspase-8–deficient patient prognosis and therapy. Overall, our study uncovers novel in vivo functions for caspase-8 in immune regulation.
Low-dose irradiation promotes tissue revascularization through VEGF release from mast cells and MMP-9–mediated progenitor cell mobilization
Authors: Heissig Beate , Rafii Shahin , Akiyama Haruyo , Ohki Yuichi , Sato Yayoi , Rafael Tejada , Zhu Zhenping , Hicklin Daniel J. , Okumura Ko , Ogawa Hideoki , Werb Zena , Hattori Koichi
Published: September 2005

Mast cells accumulate in tissues undergoing angiogenesis during tumor growth, wound healing, and tissue repair. Mast cells can secrete angiogenic factors such as vascular endothelial growth factor (VEGF). Ionizing irradiation has also been shown to have angiogenic potential in malignant and nonmalignant diseases. We observed that low-dose irradiation fosters mast cell–dependent vascular regeneration in a limb ischemia model. Irradiation promoted VEGF production by mast cells in a matrix metalloproteinase-9 (MMP-9)–dependent manner. Irradiation, through MMP-9 up-regulated by VEGF in stromal and endothelial cells, induced the release of Kit-ligand (KitL). Irradiation-induced VEGF promoted migration of mast cells from the bone marrow to the ischemic site. Irradiation-mediated release of KitL and VEGF was impaired in MMP-9–deficient mice, resulting in a reduced number of tissue mast cells and delayed vessel formation in the ischemic limb. Irradiation-induced vasculogenesis was abrogated in mice deficient in mast cells (steel mutant, Sl/Sld mice) and in mice in which the VEGF pathway was blocked. Irradiation did not induce progenitor mobilization in Sl/Sld mice. We conclude that increased recruitment and activation of mast cells following irradiation alters the ischemic microenvironment and promotes vascular regeneration in an ischemia model. These data show a novel mechanism of neovascularization and suggest that low-dose irradiation may be used for therapeutic angiogenesis to augment vasculogenesis in ischemic tissues.
Chloroquine enhances human CD8+ T cell responses against soluble antigens in vivo
Authors: Accapezzato Daniele , Visco Vincenzo , Francavilla Vittorio , Molette Caroline , Donato Tiziana , Paroli Marino , Mondelli Mario U. , Doria Margherita , Torrisi Maria Rosaria , Barnaba Vincenzo
Published: September 2005

The presentation of exogenous protein antigens in a major histocompatibility complex class I–restricted fashion to CD8+ T cells is called cross-presentation. We demonstrate that cross-presentation of soluble viral antigens (derived from hepatitis C virus [HCV], hepatitis B virus [HBV], or human immunodeficiency virus) to specific CD8+ T cell clones is dramatically improved when antigen-presenting dendritic cells (DCs) are pulsed with the antigen in the presence of chloroquine or ammonium chloride, which reduce acidification of the endocytic system. The export of soluble antigen into the cytosol is considerably higher in chloroquine-treated than in untreated DCs, as detected by confocal microscopy of cultured cells and Western blot analysis comparing endocytic and cytosolic fractions. To pursue our findings in an in vivo setting, we boosted groups of HBV vaccine responder individuals with a further dose of hepatitis B envelope protein vaccine with or without a single dose of chloroquine. Although all individuals showed a boost in antibody titers to HBV, six of nine individuals who were administered chloroquine showed a substantial CD8+ T cell response to HBV antigen, whereas zero of eight without chloroquine lacked a CD8 response. Our results suggest that chloroquine treatment improves CD8 immunity during vaccination.
AID from bony fish catalyzes class switch recombination
Authors: Barreto Vasco M. , Pan-Hammarstrom Qiang , Zhao Yaofeng , Hammarstrom Lennart , Misulovin Ziva , Nussenzweig Michel C.
Published: September 2005

Class switch recombination was the last of the lymphocyte-specific DNA modification reactions to appear in the evolution of the adaptive immune system. It is absent in cartilaginous and bony fish, and it is common to all tetrapods. Class switching is initiated by activation-induced cytidine deaminase (AID), an enzyme expressed in cartilaginous and bony fish that is also required for somatic hypermutation. Fish AID differs from orthologs found in tetrapods in several respects, including its catalytic domain and carboxy-terminal region, both of which are essential for the switching reaction. To determine whether evolution of class switch recombination required alterations in AID, we assayed AID from Japanese puffer and zebra fish for class-switching activity in mouse B cells. We find that fish AID catalyzes class switch recombination in mammalian B cells. Thus, AID had the potential to catalyze this reaction before the teleost and tetrapod lineages diverged, suggesting that the later appearance of a class-switching reaction was dependent on the evolution of switch regions and multiple constant regions in the IgH locus.
Superantigens and Chronic Rhinosinusitis: Detection of Staphylococcal Exotoxins in Nasal Polyps
Authors: Seiberling Kristin A. , Conley David B. , Tripathi Anju , Grammer Leslie C. , Shuh Lydia , Haines G Kenneth , Schleimer Robert , Kern Robert C.
Published: September 2005

Objective/Hypothesis: The role of infectious agents in the etiology of chronic rhinosinusitis with nasal polyposis (CRSwNP) remains unclear. Recent studies have provided indirect evidence of exposure to staphylococcal exotoxins in the blood and polyp tissue of patients with CRSwNP. These exotoxins have the capacity to act as superantigens, bypassing normal antigen processing and directly stimulating a massive inflammatory response. The objective of the study was to analyze mucus and polyp tissue samples from patients with CRSwNP for the presence of staphylococcal exotoxins.

Study Design: Prospective study.

Methods: Tissue and mucus samples were obtained from 42 patients undergoing endoscopic sinus surgery for chronic rhinosinusitis and 11 normal control patients. Twenty‐nine of 42 patients had chronic rhinosinusitis with bilateral nasal polyposis, 2 had antrochoanal polyps, and 11 had chronic rhinosinusitis without nasal polyps. Eleven patients without chronic rhinosinusitis or polyps served as normal control patients. Specimens were analyzed for the presence of five staphylococcal exotoxins (SEA, SEB, SEC, SED, and toxic shock syndrome toxin type 1 [TSST‐1]) using enzyme‐linked immunosorbent assay (ELISA). Histological analysis of specimens and mean eosinophil counts were correlated with the presence of toxin.

Results: At least one toxin was detected in 14 of 29 patients with bilateral nasal polyposis. Nine of the 14 patients also had positive findings for additional toxins. The dominant histological pattern in the CRSwNP patient group was polypoid mucosa with edema, which was found in both ELISA‐positive and ELISA‐negative patients. Mean eosinophil counts tended to be higher in ELISA‐positive patients with polyps compared with patients without toxin detection. No toxin was detected in the 11 specimens taken from normal control patients. Only 1 of the 13 patients with CRS without polyps had positive ELISA results for toxin.

Conclusion: The current study demonstrates the presence of superantigen toxins in 14 of 29 patients with CRSwNP, with SEB and TSST‐1 being the most common. Further studies are necessary to correlate the presence of toxin with the pathological changes present in polyp tissue.
Behavioral Assessment of Prelingually Deaf Children Before Cochlear Implantation
Authors: Horn David L. , Pisoni David B. , Sanders Mary , Miyamoto Richard T.
Published: September 2005

Objectives/Hypothesis: To determine whether scores from a behavioral assessment of prelingually deafened children who present for cochlear implant surgery are predictive of audiological outcomes

Study Design: Retrospective review of longitudinal data collected from 42 children with prelingual hearing loss who presented for a cochlear implant before age 5 years.

Methods: The Vineland Adaptive Behavioral Scales (VABS) was administered during the preimplant workup. Standardized scores reflect daily living skills, socialization, and motor development compared with a normative sample. Regression analyses were conducted to determine whether any subject variables were related to VABS scores. Mixed‐model analyses were computed to determine whether preimplant VABS scores were predictive of longitudinal spoken‐language data obtained after cochlear implant surgery.

Results: Motor scores tended to be higher than nonmotor scores. Nonmotor scores were significantly lower than the normative mean and decreased with testing age. Children with acquired deafness demonstrated lower motor scores than children with congenital causes. Children with higher motor scores demonstrated significantly higher performance on language, vocabulary, and word recognition tests than children with lower motor scores. Nonmotor domains were not as robustly related to spoken‐language measures, although similar trends were observed

Conclusion: Profound deafness and language delay may confound the assessment of daily living skills and socialization in the population studied. Motor development appears to proceed normally in prelingually deafened children and is a preimplant predictor of spoken‐language outcome in young infants and children with cochlear implants, a finding consistent with the large body of work establishing links between perceptual‐motor and language development.
Neuro‐otologic Surgery through Minimally Invasive Retrosigmoid Approach: Endoscope Assisted Microvascular Decompression, Vestibular Neurotomy, and Tumor Removal
Authors: Miyazaki Hidemi , Deveze Arnaud , Magnan Jacques
Published: September 2005

Objectives: The objective of this study was to describe and evaluate the efficacy of the endoscope assisted minimally invasive retrosigmoid approach.

Study Design: Retrospective study and literature review.

Methods: From December 1993 to December 2004, a total of 1,177 cases of endoscope assisted minimally invasive retrosigmoid approach were performed at the Otorhinolaryngology unit of Hopital Nord in Marseille. By using this approach, we performed microvascular decompression for hemifacial spasm and trigeminal neuralgia, vestibular neurotomy for refractory Ménière's disease with repeated attacks of dizziness, and tumor removal of acoustic neurinoma. We examined the results and postoperative complications.

Results: All the results were positive, and we did not experience any mortal complications. The most common complication was cerebrospinal fluid leakage, encountered in 42 (3.6%) cases.

Conclusions: We believe that the combination of an endoscope and microscope that provides accurate information with low invasion is becoming indispensable for these types of operations, which are in the category of functional surgery. We report the merits and significance of the approach of combining the endoscope and microscope and discuss the operational technique to perform a minimally invasive surgery as an oto‐neurosurgeon.
Mild Hypothermia Protects Auditory Function During Cochlear Implant Surgery
Authors: Balkany Thomas J. , Eshraghi Adrien A. , Jiao He , Polak Marek , Mou Caihong , Dietrich Dalton W. , Van De Water Thomas R.
Published: September 2005

Objective/Hypothesis: Loss of auditory function after cochlear implant (CI) electrode insertion occurs in two stages in the laboratory rat. An immediate loss is followed by a progressive loss over 7 days. Similar stages of acute and progressive neuronal loss occur after trauma in the central nervous system where hypothermia has been shown to have a protective effect. We hypothesize that hypothermia has a similar protective effect against loss of auditory function caused by CI electrode insertion trauma.

Methods: Thirty rats underwent surgery in one cochlea; the contralateral ear was an unoperated control. In the normothermia group, CI electrode insertion trauma was generated with rectal temperature maintained at 37°C throughout the experiment. In the mild hypothermia group, electrode trauma was generated with rectal temperature lowered to 34°C. In the surgical control group, mock surgery was performed at 37°C. Multiple frequency auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) testing of all ears was performed before surgery, immediately afterward, and on postoperative days 3, 5, and 7.

Results: Both ABR and DPOAE testing demonstrated partial loss of auditory function after electrode insertion trauma. However, the hypothermia group had significantly less functional loss in the immediate stage and no significant loss in the progressive stage.

Conclusion: Mild hypothermia protects auditory function during CI electrode insertion.
Orientation of the Manubrium Mallei: Inexplicably Widely Variable
Authors: Todd N Wendell
Published: September 2005

Background: There is no consensus why the manubrium of the malleus, as viewed clinically through the external ear canal, generally points downward and posteriorly.

Objectives: To depict the alignment of the handle of the malleus, viewed clinically through the external auditory canal, relative to the zygomatic arch, the Frankfort plane, and a visual plane proxy and relative to the horizontal semicircular canal. Also, to assess bilateral symmetry and manubrium alignment relative to mastoid pneumatization.

Study Design: Postmortem anatomic dissection of 41 bequeathed adult crania without clinical otitis.

Methods: The line of the manubrium as viewed through the external ear canal was measured relative to the Frankfort plane, to a proxy of the visual plane, and to the zygomatic arch. Mastoid sizes were determined radiographically. In a subset of 10 crania additionally studied by computed tomography, the manubrium position was checked relative to the horizontal semicircular canal.

Results: Relative to the zygomatic arch and Frankfort and visual planes, the range of manubrium angles was at least 45 degrees. Bilateral symmetry was found, each r 0.38 or greater (P < .05). Relative to the horizontal canals, the range of manubrial angles was 30 degrees, with symmetry suggested. Alignment did not correlate with mastoid pneumatization.

Conclusion: Manubrium orientation as viewed through the external auditory canal is not obviously explicable. The wide variety of manubrium orientations may explain the manubrium‐stapes offset that perplexes manubrium‐stapes surgical constructions.
“Window Shade” Tympanoplasty for Anterior Marginal Perforations
Authors: Schraff Scott , Dash Nariman , Strasnick Barry
Published: September 2005

Objectives/Hypothesis: Anterior marginal perforations of the tympanic membrane often present a reconstructive challenge to the otolaryngologist. Poor surgical outcomes are often due to inadequate exposure, a lack of residual tympanic membrane, impaired vascular supply, and delayed healing. This study reports on the success of the “window shade” technique, combining aspects of both the traditional underlay and overlay tympanoplasty techniques, for the management of anterior marginal tympanic membrane perforations.

Study Design: Retrospective review of patients undergoing window shade tympanoplasty from July 1, 1994, to July 1, 2003, at a tertiary care referral center.

Methods: Only patients found to have anterior tympanic membrane perforations and who underwent a window shade tympanoplasty were included in the study. Tympanoplasty success rate was studied by examining postoperative complications of recurrent perforation, tympanic membrane lateralization, or anterior blunting.

Results: The authors identified 164 patients who underwent window shade tympanoplasty during the study period. The overall success rate for tympanic membrane repair was 94.5%. There were no cases of tympanic membrane lateralization or significant blunting. The average healing time was 4 weeks. The surgical technique is described in detail.

Conclusion: The window shade tympanoplasty is an excellent surgical option for repair of anterior marginal perforations of the tympanic membrane.
Carcinoid Tumor of the Middle Ear: Clinical Features, Recurrences, and Metastases
Authors: Ramsey Mitchell J. , Nadol Joseph B. , Pilch Benjamin Z. , McKenna Michael J.
Published: September 2005

Objective: Present four new cases of carcinoid tumor of the middle ear, two of which developed late recurrences and regional metastases. Review the literature to identify the clinical features, rate of recurrence, and incidence of metastasis of carcinoid tumor of the middle ear.

Study Design: Retrospective chart review.

Setting: Tertiary referral hospital.

Patients: Eligibility criteria consist of a diagnosis of carcinoid tumor of middle ear.

Intervention: Surgical excision of primary and metastatic disease.

Main Outcome Measure: Clinical characteristics, rate of recurrence, and incidence of metastasis of carcinoid tumor of the middle ear.

Results: Forty‐six patients with carcinoid tumor of the middle ear are included in this report, 42 patients were identified from a review of the literature, and 4 new patients are presented. The most common presenting symptom was hearing loss. Surgical excision was the treatment with radical mastoidectomy being the most common procedure. Ten (22%) patients developed locally recurrent disease, and four (9%) developed regional metastases.

Conclusions: Carcinoid tumor of the middle ear is an infrequent cause of a middle ear mass, with only 46 cases published. Despite previous assertions of benignancy, the findings of this study suggest that carcinoid tumor of the middle ear is indeed a potential low‐grade malignancy with documented metastatic potential. Almost all middle ear adenomatous tumors (“adenoma” and “carcinoid”) show evidence of neuroendocrine differentiation, and so at least some middle ear carcinoids (“adenomas”) appear to represent well‐differentiated neuroendocrine carcinomas. Presentation and symptoms are consistent with a middle ear mass and rarely include carcinoid syndrome. Surgical treatment is recommended and tailored to the extent of disease. Patients with carcinoid tumor of the middle ear require indefinite follow‐up for possible recurrence or metastasis.
Oropharyngeal Complications Of Suspension Laryngoscopy: A Prospective Study
Authors: Rosen Clark A. , Filho Pedro A. Andrade , Scheffel Lucia , Buckmire Robert
Published: September 2005

Objective: This study was designed to evaluate the oropharyngeal complications of suspension laryngoscopy (SL).

Methods: We prospectively analyzed 56 consecutive SLs for intervention‐related complications. Oropharyngeal symptoms and physical examination abnormalities were recorded before and after SL. SL‐related problems were graded in severity and followed over time (weekly) until resolution was achieved. All patients had SL with either a gallows suspension or a manual technique and not a rotation‐oriented (fulcrum) laryngoscope holding device.

Results: Oropharyngeal minor complications after SL occurred at a rate of 37.5%, and all these were temporary. No dental injuries occurred in the study cohort. There were no major complications after SL. Minor alterations related to taste occurred in 18% of the patients, 16% of patients had subjective swallowing complaints, and 12.5% had partial tongue numbness. Average duration of the post‐SL complaints was 11 (6–34) days. A correlation between duration of suspension, size of laryngoscope, and risk of developing a minor oropharyngeal complication was present.

Conclusion: SL carries a higher risk for lingual and glossopharyngeal nerve injuries than previously recognized. All of these complications were temporary. On the basis of comparison with historic data, SL by gallows suspension technique may pose a lower risk of dental injuries. This information should be used to improve preoperative SL patient education and informed consent.
Impact of Neck Length on the Safety of Percutaneous and Surgical Tracheotomy: a Prospective, Randomized Study
Authors: Tabaee Abtin , Geng Elvin , Lin Jerry , Kakoullis Stylianos , McDonald Brian , Rodriguez Hector , Chong David
Published: September 2005

Objective: To investigate a correlation between neck length and the incidence of complications after both percutaneous and surgical tracheotomy (ST) and to compare the relative safety of the two procedures at our institution.

Study Design: Prospective, randomized study of patients undergoing tracheotomy at a tertiary care center.

Methods: Forty‐three patients evaluated for tracheotomy at our institution between the years 2003 and 2004 were enrolled in the study and were randomly assigned to receive either an ST or a percutaneous dilatational tracheotomy (PDT). All patients underwent standardized measurement of the cricosternal distance (CSD) in the neutral and extended positions before the procedure. Demographic and procedural variables were recorded, and the occurrence of postoperative complications was followed for 1 week.

Results: PDT was performed in 29 patients and ST in 14 patients. The mean CSD of 2.7 cm increased to 3.7 cm after extension with a shoulder roll. PDT required less time (mean 8 vs. 23 minutes) and resulted in less blood loss compared with ST. A trend toward a higher incidence of complications with PDT (40%) compared with ST (7%) and in the first half of our series (learning curve) was noted. This, however, did not reach statistical significance. There was no correlation between the incidence of complications and neck length as determined by the CSD in either group of patients.

Conclusions: We failed to demonstrate a correlation between CSD and tracheotomy related complications. Patients with short necks may be at no higher risk during either a PDT or ST. Experience, awareness of complications, and a dedicated team approach are necessary for the safe performance of PDT.
Effect of Growth Factors on Cell Proliferation, Matrix Deposition, and Morphology of Human Nasal Septal Chondrocytes Cultured in Monolayer
Authors: Richmon Jeremy D. , Sage August B. , Shelton Elliot , Schumacher Barbara L. , Sah Robert L. , Watson Deborah
Published: September 2005

Objectives: Tissue engineering of septal cartilage provides ex vivo growth of cartilage from a patient's own septal chondrocytes for use in craniofacial reconstruction. To become clinically applicable, it is necessary to rapidly expand a limited population of donor chondrocytes and then stimulate the production of extracellular matrix on a biocompatible scaffold. The objective of this study was to determine favorable serum‐free culture conditions for proliferation of human septal chondrocytes using various concentrations and combinations of four growth factors.

Study Design: Prospective, randomized, controlled study.

Methods: Nasal septal chondrocytes from six patient donors were isolated by enzymatic digestion and expanded in monolayer culture in both serum‐free media (SFM) and 2% fetal bovine serum (FBS). Both of these groups were exposed to varying concentrations and combinations of transforming growth factor (TGF)‐β1, basic fibroblast growth factor (FGF)‐2 both at 1, 5, and 25 ng/mL, and bone morphogenetic protein (BMP)‐2 and insulin‐like growth factor (IGF)‐1, both at 5, 25, and 125 ng/mL in the medium during the expansion phase. Cell morphology was assessed throughout the culture duration. After 7 days of monolayer growth, cultures were assessed for cellularity and glycosaminoglycan (GAG) content.

Results: The addition of low‐dose FBS in culture media consistently led to significantly greater cell proliferation and matrix deposition than the SFM cell cultures. FGF‐2 and TGF‐β1 both alone and in combination led to the greatest proliferative effect compared with the other growth factors. In contrast, BMP‐2 and IGF‐1 led to the least cell proliferation although was most effective in retaining chondrocyte cell morphology.

Conclusions: With the addition of TGF‐β1 and FGF‐2 to culture media, the concentration of serum can be greatly decreased and possibly eliminated altogether without jeopardizing cell proliferation.
Prevention of Esophageal Strictures in a Caustic Burn Model Using Halofuginone, an Inhibitor of Collagen Type I Synthesis
Authors: Arbell Dan , Udassin Raphael , Koplewitz Benjamin Z. , Ohana Meir , Genina Olga , Pines Mark , Nagler Arnon
Published: September 2005

Objective: Esophageal strictures caused by caustic injury continue to be a plaguing problem. Halofuginone (HF) has been proven to inhibit the formation of fibrosis in various animal models and human diseases. Its mechanism appears to be through the suppression of the production of collagen α1(I) and transforming growth factor‐β signaling pathway. We tried to assess whether HF would have an effect on the formation of strictures after inducing caustic esophageal.

Materials and Methods: Esophageal injury was caused by injecting 25% NaOH to an isolated esophageal segment. Study group rats were treated with HF orally for 3 consecutive days before the injury and afterward. Control group rats received regular chow. The results were evaluated by upper gastrointestinal series (UGI) and through pathologic studies.

Results: HF treatment resulted in marked improvement in the esophageal strictures. The UGI series showed esophageal patency of 73% (45%–100%) in the treated animals (n = 7) as compared with almost no patency, 11% (5–16%), in the controls (n = 4) (P = .018). The histologic examination showed significantly less stricture and scarring in the treated group. Whereas the ratio between the esophageal wall thickness to mucosal thickness was 2.34 ± 0.23 in the study group, the control group had a ratio of 9.56 ± 0.69 (P = .0044). Finally, whereas 86% of the study group survived, all the rats in the control group died by day 20.

Conclusions: HF modulated the wound healing reaction caused by caustic injury of the esophagus in a rat model, resulting in increased esophageal patency, reduction in esophageal wall thickness, and increased survival.
Evaluation of antioxidant properties of dermocosmetic creams by direct electrochemical measurements
Authors: Guitton C. , Gros P. , Comtat M. , Tarroux R. , Bordat P.
Published: September 2005

Cyclic voltammetry and linear sweep voltammetry were preliminarily used in order to evaluate the global antioxidant properties of dermocosmetic creams. Experiments were performed by introducing electrodes directly into the creams without any pretreatment of the samples. Current–potential curves showed significant anodic current depending on the antioxidant‐containing cream studied. In comparison, little amperometric response was recorded with an antioxidant‐free cream base. Aqueous solutions of the corresponding antioxidants showed analogous anodic waves and similar peak potentials. A correlation between the global anodic peak and the presence of the antioxidant species in the cream was made with eleven skin creams, attesting to the reliability of the method. Among the tested electrode materials, platinum gave the best results in terms of electrochemical kinetics and measurement precision (current peak standard deviation <5%). Exposure of a depilatory cream to oxidizing agents (e.g. hydrogen peroxide, air, or light) caused a decrease in peak current as expected. This methodology enabled us to evaluate the evolution of the total antioxidant capacity under oxidative stress and gives encouragement to further development of a voltammetric method to quantify cream antioxidant power.
Proton pump inhibitors reduce the bioavailability of dietary vitamin C
Authors: HENRY E. B. , CARSWELL A. , WIRZ A. , FYFFE V. , MCCOLL K. E. L.
Published: September 2005

Background : The gastric juice concentration of vitamin C is reduced in subjects with elevated intragastric pH. This is probably because of the fact that the vitamin is unstable at non‐acidic pH and undergoes irreversible denaturation.

Aim : To determine whether elevation of intragastric pH reduces the bioavailability of dietary vitamin C.

Methods : Plasma vitamin C was measured before and after a course of omeprazole 40 mg/day for 4 weeks in 14 Helicobacter pylori positive and 15 H. pylori negative subjects. Dietary intake of vitamin C was measured and intragastric pH monitored.

Results : Compared with the H. pylori negative subjects, H. pylori positive subjects had a lower mean daily vitamin C intake (141.7 mg vs. 41.5 mg, P < 0.01) and also lower plasma vitamin C concentration (25.1 μg/mL vs. 17.4 μg/mL, P < 0.0001). After 28 days of 40 mg/day of omeprazole the mean plasma vitamin C level had fallen by 12.3% (P = 0.04). This fall affected both the H. pylori positive and negative subjects.

Conclusions : We have shown that a short course of omeprazole will cause a reduction in the plasma vitamin C level of healthy volunteers. This decrease in plasma vitamin C is independent of dietary intake of the vitamin and indicates reduced bioavailability. The clinical significance of this is unclear but any adverse effects will be most apparent in H. pylori infected subjects who have a low pre‐treatment vitamin C status.
Helicobacter pylori‐associated ulcer bleeding: should we test for eradication after treatment?
Authors: POHL H. , FINLAYSON S. R. G. , SONNENBERG A. , ROBERTSON D. J.
Published: September 2005

Background : Eradication of Helicobacter pylori after peptic ulcer haemorrhage reduces the risk of recurrence. Because H. pylori treatment is very effective, it is unclear whether testing to confirm eradication is worthwhile.

Aims : To examine whether patients with H. pylori‐associated peptic ulcer haemorrhage should be tested for successful eradication after completion of antibiotic therapy.

Methods : A Markov cost‐effectiveness model was developed to compare testing vs. non‐testing of H. pylori eradication in peptic ulcer haemorrhage. Probability estimates and average costs were derived from published information.

Results : Testing for H. pylori eradication resulted in a benefit of 0.07 quality‐adjusted life‐years and cost $836 less than the strategy of not confirming eradication. Testing remained the superior strategy when varying the model regarding age, the initial success of eradication, various test and retreatment strategies, and the rate and costs of recurrent bleeding. Assuming a high eradication rate (95%), the test strategy becomes more expensive only if the cost of H. pylori testing reaches $265; however, even under these conditions it remains cost‐effective.

Conclusions : Patients with H. pylori‐associated peptic ulcer bleeding should be tested to confirm eradiation of H. pylori after completion of antibiotic treatment.
Antibiotic prophylaxis for percutaneous endoscopic gastrostomy for non‐malignant conditions: a double‐blind prospective randomized controlled trial
Authors: SAADEDDIN A. , FRESHWATER D. A. , FISHER N. C. , JONES B. J. M.
Published: September 2005

Background : The use of antibiotic prophylaxis prior to percutaneous endoscopic gastrostomy insertion has been encouraged following development of guidelines by a number of professional societies within the past few years. However, not all evidence supports routine prophylaxis, particularly in patients with ‘benign’ disease indications for percutaneous endoscopic gastrostomy insertion.

Aim : To identify whether prophylactic antibiotic usage is beneficial in patients undergoing percutaneous endoscopic gastrostomy insertion without malignant disease.

Methods : Adult patients without malignant disease who were referred for percutaneous endoscopic gastrostomy insertion at our unit were assessed for participation in this prospective, double‐blind, randomized controlled study. Patients were randomized to receive either placebo or 2.2 g co‐amoxiclav (or 2 g cefotaxime if penicillin‐allergic) at time of percutaneous endoscopic gastrostomy insertion. Clinical endpoints studies were percutaneous endoscopic gastrostomy site or systemic infection and death within 7 days of percutaneous endoscopic gastrostomy insertion.

Results : Ninety‐nine patients completed the study (51 antibiotics, 48 placebo). Outcomes in the antibiotic and placebo groups respectively were: percutaneous endoscopic gastrostomy site infection, 11% vs. 47% (P < 0.01); systemic infection, 16% vs. 38% (P < 0.05); and death, 8% vs. 15% (P = 0.5).

Conclusions : Antibiotic prophylaxis prior to percutaneous endoscopic gastrostomy insertion reduces both percutaneous endoscopic gastrostomy site and systemic infections in patients without malignant disease.
Review article: bifidobacteria as probiotic agents – physiological effects and clinical benefits
Authors: PICARD C. , FIORAMONTI J. , FRANCOIS A. , ROBINSON T. , NEANT F. , MATUCHANSKY C.
Published: September 2005

Bifidobacteria, naturally present in the dominant colonic microbiota, represent up to 25% of the cultivable faecal bacteria in adults and 80% in infants. As probiotic agents, bifidobacteria have been studied for their efficacy in the prevention and treatment of a broad spectrum of animal and/or human gastrointestinal disorders, such as colonic transit disorders, intestinal infections, and colonic adenomas and cancer. The aim of this review is to focus on the gastrointestinal effects of bifidobacteria as probiotic agents in animal models and man. The traditional use of bifidobacteria in fermented dairy products and the GRAS (‘Generally Recognised As Safe’) status of certain strains attest to their safety. Some strains, especially Bifidobacterium animalis strain DN‐173 010 which has long been used in fermented dairy products, show high gastrointestinal survival capacity and exhibit probiotic properties in the colon. Bifidobacteria are able to prevent or alleviate infectious diarrhoea through their effects on the immune system and resistance to colonization by pathogens. There is some experimental evidence that certain bifidobacteria may actually protect the host from carcinogenic activity of intestinal flora. Bifidobacteria may exert protective intestinal actions through various mechanisms, and represent promising advances in the fields of prophylaxis and therapy.
Thirteen novel mutations in the factor VIII gene in the Nijmegen haemophilia A patient population
Authors: Boekhorst Jorien , Verbruggen Bert , Lavergne Jean Maurice , Costa Jean‐Marc , Schoormans Selene C. M. , Brons Paul P. T. , van Kraaij Marian G. J. , Nováková Irena R. O. , van Heerde Waander L.
Published: September 2005

The development of neutralising antibodies to factor VIII (FVIII) is a major complication of haemophilia A (HA) therapy. We aimed to construct an individual risk profile for the development of inhibitors in HA and started by screening for the causative mutation in our HA patient population. A total of 109 patients and 28 carriers were screened. The analysis revealed 38 different mutations in the FVIII gene, of which 13 have not been described on the Haemophilia A Mutation, Search, Test and Resource Site (HAMSTeRS). Twenty‐five mutations have been reported previously and all except two had a similar phenotype to what has been described. Three novel mutations were associated with severe HA: one non‐missense mutation, a small insertion in the A2 domain, and two missense mutations, a H256R mutation in the A1 domain and a L2025P substitution in the C1 domain. One novel mutation, Y156C, was associated with moderate HA. Nine novel mutations caused mild HA. The P130R, D167E and V278M mutations are located in the A1 domain. R439C, Y511H, A544G and Q645H in the A2 domain, L1758F in the A3 domain and a S2157R mutation in the C1 domain. In conclusion, the genotypic profile of our HA population was not different from others described and is suitable to study inhibitor formation.
Stomatin is mis‐trafficked in the erythrocytes of overhydrated hereditary stomatocytosis, and is absent from normal primitive yolk sac‐derived erythrocytes
Authors: Fricke Britta , Parsons Stephen F. , Knöpfle Gisela , von Düring Monika , Stewart Gordon W.
Published: September 2005

The 32 kD lipid‐raft‐associated membrane protein ‘stomatin’ is deficient from the erythrocyte membrane in the Na+–K+ leaky haemolytic anaemia, overhydrated hereditary stomatocytosis (OHSt). To date, no mutation in the gene coding for this protein has so far been found in OHSt. In this study, we have analysed the distribution of stomatin in both cultured erythroid cells from OHSt patients and in normal embryological and fetal erythroid development. In erythroid cell cultures from OHSt patients, stomatin‐immunoreactivity (stomatin‐IR) was present in progenitor cells but remained restricted to the area of the multivesicular complexes and the nucleus in the developing cells and was not seen in the plasma membrane. This could be consistent with the idea that stomatin is an innocent passenger in a more fundamental trafficking abnormality. In normal embryonic development, we found that, in extraembryonic (yolk sac) erythropoiesis, neither the nucleated red cells nor their enucleated mature derivatives displayed any stomatin‐IR. In contrast, all haemangiopoietic progenitor cells of intraembryonic haematopoiesis, starting with the mesodermal precursors in the aorta–gonad–mesonephros region, exhibited strong stomatin‐IR. The significance of this observation on these poorly understood cells is currently unclear.
The paradox of matrix metalloproteinases in infectious disease
Authors: Elkington P T G , O'Kane C M , Friedland J S
Published: September 2005

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that perform multiple roles in the normal immune response to infection. MMPs facilitate leucocyte recruitment, cytokine and chemokine processing, defensin activation and matrix remodelling. However, excess MMP activity following infection may lead to immunopathology that causes host morbidity or mortality and favours pathogen dissemination or persistence. Here, we review the normal functions of MMPs in immunity and then discuss viral and bacterial infections where excess MMP activity has been implicated in pathology, specifically examining HIV, HTLV-1, hepatitis B, endotoxin shock, Helicobacter pylori and Mycobacterium tuberculosis. Tissue destruction may be exacerbated further by bacterial-derived enzymes which activate the host pro-MMPs. Finally, the potential for therapeutic targeting of excess MMP activity in infection is considered.
Diagnosis ofMycobacterium tuberculosisinfection using ESAT-6 and intracellular cytokine cytometry
Authors: Hughes A J , Hutchinson P , Gooding T , Freezer N J , Holdsworth S R , Johnson P D R
Published: September 2005

Diagnosis of infection with Mycobacterium tuberculosis (MTB) using tuberculin skin testing (TST) is often hampered by prior Bacille Calmette–Guérin (BCG) vaccination. ESAT-6 is a protein that is expressed by MTB but absent in BCG. It has been postulated that it might be useful in distinguishing MTB-specific immune responses. This study measured CD4 T cell responder frequencies specific for ESAT-6 and the TST reagent purified protein derivative (PPD) in patients with tuberculosis (n = 16), controls with non-tuberculous pneumonia (n = 8) and normal subjects (n = 7). Responses were identified using the intracellular cytokine staining technique and flow cytometry on whole blood samples, and performed blinded to the patient condition. Antigen-specific CD4 cells were defined by CD69 positivity and one or more cytokine [interleukin (IL)-2, IL-4, IL-10, interferon (IFN)-γ] and/or CD40L positivity. With ESAT-6 stimulation it was found that TB patients had significantly higher frequencies of IFN-γ and CD40L-positive CD4 T cells compared to the normal group, while no significant differences were measured with PPD stimulation. A responder frequency of 0·01% or higher for at least one of the measured cytokines/CD40L was defined as a positive response. Using this criterion to compare the two patient groups, PPD had 100% sensitivity but 0% specificity while ESAT-6 had 100% sensitivity and 88% specificity. Use of MTB-specific proteins such as ESAT-6 in combination with intracellular cytokine staining and flow cytometry has the potential to identify individuals with MTB infection.
T helper cell-mediated interferon-gamma expression after human parvovirus B19 infection: persisting VP2-specific and transient VP1u-specific activity
Authors: Franssila R , Auramo J , Modrow S , Möbs M , Oker-Blom C , Käpylä P , Söderlund-Venermo M , Hedman K
Published: September 2005

Human parvovirus B19 is a small non-enveloped DNA virus with an icosahedral capsid consisting of proteins of only two species, the major protein VP2 and the minor protein VP1. VP2 is contained within VP1, which has an additional unique portion (VP1u) of 227 amino acids. We determined the ability of eukaryotically expressed parvovirus B19 virus-like particles consisting of VP1 and VP2 in the ratio recommended for vaccine use, or of VP2 alone, to stimulate, in an HLA class II restricted manner, peripheral blood mononuclear cells (PBMC) to proliferate and to secrete interferon gamma (IFN-γ) and interleukin (IL)-10 cytokines among recently and remotely B19 infected subjects. PBMC reactivity with VP1u was determined specifically with a prokaryotically expressed VP1u antigen. In general, B19-specific IFN-γ responses were stronger than IL-10 responses in both recent and remote infection; however, IL-10 responses were readily detectable among both groups, with the exception of patients with relapsed or persisting symptoms who showed strikingly low IL-10 responses. Whereas VP1u-specific IFN-γ responses were very strong among the recently infected subjects, the VP1u-specific IFN-γ and IL-10 responses were virtually absent among the remotely infected subjects. The disappearance of VP1u-specific IFN-γ expression is surprising, as B-cell immunity against VP1u is well maintained.