Lack of CXC chemokine receptor 3 signaling leads to hypertrophic and hypercellular scarring

CXC chemokine receptor 3 (CXCR3) signaling promotes keratinocyte migration while terminating fibroblast and endothelial cell immigration into wounds; this signaling also directs epidermal and matrix maturation. Herein, we investigated the long-term effects of failure to activate the "stop-healing" CXCR3 axis. Full-thickness excisional wounds were created on CXCR3 knockout((-/-)) or wild-type mice and examined at up to 180 days after wounding. Grossly, the CXCR3(-/-) mice presented a thick keratinized scar compared with the wild-type mice in which the scar was scarcely noticeable; histological examination revealed thickening of both the epidermis and dermis. The dermis was disorganized with thick and long collagen fibrils and contained excessive collagen content in comparison with the wild-type mice. Interestingly, the CXCR3(-/-) wounds presented lower tensile/burst strength, which correlates with decreased alignment of collagen fibers, similar to published findings of human scars. Persistent Extracellular matrix turnover and immaturity was shown by the elevated expression of proteins of the immature matrix as well as expression of matrix metallopeptidase-9 MMP-9. Interestingly, the scars in the CXCR3(-/-) mice presented evidence of de novo development of a sterile inflammatory response only months after wounding; earlier periods showed resolution of the initial inflammatory stage. These in vivo studies establish that the absence of CXCR3(-/-) signaling network results in hypertrophic and hypercellular scarring characterized by on-going wound regeneration, cellular proliferation, and scars in which immature matrix components are undergoing increased turnover resulting in a chronic inflammatory process.

Effects of transforming growth factor-beta1 on human vocal fold fibroblasts

OBJECTIVES

We studied the effect of transforming growth factor (TGF)-beta on immortalized human vocal fold fibroblasts.

METHODS

Normal human vocal fold fibroblasts were subjected to sequential lentiviral transduction with genes for human telomerase (hTERT) and SV40 large T antigen in order to produce an "immortalized" cell line of normal phenotype. After confirmation of vocal fold fibroblast transfection, these cells, referred to as HVOX, were treated with various concentrations of exogenous TGF-beta1 and assayed for collagen secretion, migration, and proliferation. In addition, components of the TGF-beta signaling pathway were examined in this cell line.

RESULTS

TGF-beta stimulated collagen secretion and migration without altering proliferation of HVOX. HVOX constitutively expressed type I and II TGF-beta receptors, as well as messenger RNA for the Smad signaling proteins and for all TGF-beta isoforms. Exogenous TGF-beta1 induced temporally dependent alterations in Smad2 and Smad3 gene expression. TGF-beta increased Smad7 expression at both 4 and 24 hours. Prolonged exposure to TGF-beta decreased TGF-beta1 gene expression.

CONCLUSIONS

Insight into the underlying pathophysiology of vocal fold fibrosis is likely to yield improved therapeutic strategies to mitigate vocal fold scarring. Our data suggest that TGF-beta signaling may be both paracrine and autocrine in this vocal fold fibroblast cell line, and we therefore propose that TGF-beta may be a reasonable target for therapies to prevent and/or treat vocal fold fibrosis, given its putative role in both acute and chronic vocal fold injury, as well as its effects on vocal fold fibroblasts.

The effect of multifunctional polymer-based gels on wound healing in full thickness bacteria-contaminated mouse skin wound models

We determined whether a two-part space-conforming polyethylene glycol/dopa polymer-based gel promoted healing of contaminated wounds in mice. This silver-catalysed gel was previously developed to be broadly microbiocidal in vitro while being biocompatible with human wound cell functioning. Full-thickness wounds were created on the backs of mice. The wounds were inoculated with 10(4) CFU of each of four common skin wound contaminants, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumanii and Clostridium perfringens. The wounds were then treated with our multifunctional polymer-based gel, the commercially available NewSkin product, or left to heal untreated. The untreated wounds were overtly infected, and presented detectable bacterial loads over the entire 21-day healing period, while the gel and NewSkin groups presented significantly smaller rises in bacterial levels and were cleared of detectable colonies by the third week, with the gel group clearing the bacteria earlier. While all three groups healed their wounds, the polymer-based gel-treated group demonstrated significantly earlier re-epithelialization and dermal maturation (P<0.05). This was reflected in a quick regain of tensile strength. This accelerated dermal maturation and regain in strength was noted in mice treated with the polymer-based gel when compared to wound treated with the commercially available Aquacel-Ag dressing (P<0.05). What distinguishes the polymer-based gel from these other products is that it is incorporated within the healing wound. These preclinical studies show that the anti-microbial polymer gel not only supports but also accelerates healing of bacterially contaminated wounds.

Primed fibroblasts and exogenous decorin: potential treatments for subacute vocal fold scar

OBJECTIVE

To investigate hepatocyte growth factor (HGF) primed fibroblasts and decorin application on skin and vocal fold fibroblasts in vitro and in vivo in rabbit vocal fold scar model.

STUDY DESIGN AND SETTING

Vocal fold and skin fibroblasts underwent five in vitro treatment conditions: control, epidermal growth factor, HGF, both decorin and HGF, and decorin alone. Hyaluronic acid and collagen enzyme-linked immunosorbent assays were performed. In vivo, 12 rabbits underwent unilateral vocal fold stripping. Injured vocal folds were then injected with skin fibroblasts, HGF, HGF-primed fibroblasts and decorin, or decorin. Outcomes included histologic and lamina propria height analyses.

RESULTS

In vitro, HGF increased hyaluronic acid synthesis in vocal fold fibroblasts (P<0.001). HGF and decorin treatment diminished collagen secretion (P<0.01). In vivo, histologic findings indicated minimal difference in collagen amount between treatment groups.

CONCLUSION

HGF and decorin together may decrease collagen production by skin and vocal fold fibroblasts. Fibroblast transplantation into scarred vocal folds has equivocal benefit.

Operating Room Versus Office-Based Injection Laryngoplasty: A Comparative Analysis of Reimbursement

BACKGROUND

Injection laryngoplasty (IL) continues to evolve as new indications, techniques, approaches, and injection materials are developed. Although historically performed under local or general anesthesia in the operating room suite, IL is now increasingly being performed in an office-based setting. This report presents the results of a reimbursement analysis comparing office-based versus operative IL.

OBJECTIVE

The objective of this study was to compare the reimbursement of office-based injection laryngoplasty with the reimbursement of performing the same procedure in the operating room.

DESIGN

The authors conducted reimbursement and outcome analysis through retrospective office chart and hospital record review.

METHODS

A retrospective review was performed of the hospital records of patients having undergone injection laryngoplasty at the University of Pittsburgh Voice Center from July 1998 through March 2005. Group I included patients who underwent IL in the operating room, whereas group II included those who had office-based IL. A reimbursement analysis for both groups was then performed comparing surgeon fees, anesthesia, and hospital charges and reimbursement. The clinical efficacy of IL performed in either office versus operating room settings was measured by comparing the pre- and postintervention Voice Handicap Index-10 scores for all patients. A predictive model of potential cost savings is developed based on the results of the analysis.

RESULTS

Average reimbursement was 2,505 dollars for group I (n = 108) and 496 dollars for group II (n = 50). This reimbursement differential was preserved across the various insurance types examined. There was no significant difference in Voice Handicap Index-10 change after surgery between group I and II.

CONCLUSIONS

Office-based IL is both clinically and financially effective, providing patients with a convenient and flexible alternative to operating room-based intervention for glottal insufficiency.

Office-Based Arytenoid Palpation for Diagnosis of Disorders of Bilateral Vocal Fold Immobility

Bilateral vocal fold immobility is an uncommon but serious condition with many causes. Accordingly, accurate diagnosis is essential in order to treat patients promptly and avoid long-term sequelae. Historically, diagnosis has been performed in the operating room with the patient under general anesthesia. We present the case of a patient who was diagnosed with bilateral vocal fold immobility by in-office arytenoid palpation that required only topical anesthesia of the larynx. The patient subsequently underwent appropriate treatment. In our opinion, office-based arytenoid palpation is a simple, safe, and accurate procedure for diagnosing bilateral vocal fold immobility.

Office-based arytenoid palpation for diagnosis of disorders of bilateral vocal fold immobility

Bilateral vocal fold immobility is an uncommon but serious condition with many causes. Accordingly, accurate diagnosis is essential in order to treat patients promptly and avoid long-term sequelae. Historically, diagnosis has been performed in the operating room with the patient under general anesthesia. We present the case of a patient who was diagnosed with bilateral vocal fold immobility by in-office arytenoid palpation that required only topical anesthesia of the larynx. The patient subsequently underwent appropriate treatment. In our opinion, office-based arytenoid palpation is a simple, safe, and accurate procedure for diagnosing bilateral vocal fold immobility.

Hearing Loss as the Initial Presentation of Creutzfeldt-Jakob Disease

Creutzfeldt-Jakob disease is a rare type of spongiform encephalopathy. Affected patients present with constitutional symptoms, which progress to severe mental deterioration and movement disorders. Dizziness is the most common early otologic symptom. Few reports in the literature describe patients with Creutzfeldt-Jakob disease who present with sudden-onset hearing loss as their primary symptom for seeking treatment. This paper discusses one such patient and reviews the clinical presentation, treatment options, and relevant literature.

Hearing loss as the initial presentation of Creutzfeldt-Jakob disease

Creutzfeldt-Jakob disease is a rare type of spongiform encephalopathy. Affected patients present with constitutional symptoms, which progress to severe mental deterioration and movement disorders. Dizziness is the most common early otologic symptom. Few reports in the literature describe patients with Creutzfeldt-Jakob disease who present with sudden-onset hearing loss as their primary symptom for seeking treatment. This paper discusses one such patient and reviews the clinical presentation, treatment options, and relevant literature.

Current practice patterns in tonsillectomy and perioperative care

OBJECTIVES

Tonsillectomy is one of the most commonly performed otolaryngologic procedures in the United States. Many options and controversies exist regarding techniques and peri-operative management. The purpose of the study was to examine current practice patterns among otolaryngologists regarding tonsillectomy.

METHODS

A 13 question survey regarding tonsillectomy techniques and peri-operative management was mailed to 10% of randomly selected board certified otolaryngologists of the AAO-HNS in the spring of 2002. Four hundred and eighteen anonymously completed questionnaires were returned, for a response rate of 58.5%. Statistical analysis of survey data was performed by means of cross tabulation and Pearson Chi-Square Calculation.

RESULTS

Monopolar electrocautery was the most common technique used among those surveyed (53.5%). There was a significant correlation between choice of monopolar electrocautery and the cited reason for choice of technique being decreased blood loss (P < 0.001). There was no relationship between pediatric fellowship training and choice of technique. 97.7% routinely admitted sleep apnea patients for post-operative observation. There was no significant correlation between practice setting (tertiary versus community) and type of post-operative monitoring for sleep apnea patients, with patients most commonly admitted to an intermediate care setting.

CONCLUSION

In our survey, the most common surgical technique for tonsillectomy was monopolar electrocautery, chosen for the reason of decreased blood loss.

Self-inflicted vocal cord paralysis in patients with vagus nerve stimulators. Report of two cases

Vagus nerve stimulation for treatment of epilepsy is considered safe; reports of severe complications are rare. The authors report on two developmentally disabled patients who experienced vocal cord paralysis weeks after placement of a vagus nerve stimulator. In both cases, traction injury to the vagus nerve resulting in vocal cord paralysis was caused by rotation of the pulse generator at the subclavicular pocket by the patient. Traumatic vagus nerve injury caused by patients tampering with their device has never been reported and may be analogous to a similar phenomenon reported for cardiac pacemakers in the literature. As the use of vagus nerve stimulation becomes widespread it is important to consider the potential for this adverse event.

Post-tonsillectomy bleeding: a meta-analysis

OBJECTIVE/HYPOTHESIS

To reconcile conflicting reports and opinions of the value of preoperative coagulation studies for patients undergoing tonsillectomy.

STUDY DESIGN

Meta-analysis: Articles were identified by MEDLINE search, references from review articles, textbook chapter, and retrieved reports. Independent observers selected prospective trials of patients undergoing tonsillectomy or adenoidectomy and tonsillectomy. Retrospective studies meeting other inclusion and exclusion criteria were included for sensitivity analyses of results.

METHODS

Data were abstracted from studies for an end point of bleeding with normal and abnormal coagulation tests. Four prospective studies met all inclusion and exclusion criteria. These four studies were used in the data synthesis. An additional eight retrospective studies met all other criteria and were used in the sensitivity analysis.

RESULTS

Pooled analysis of 3384 patients revealed a rate of 3.3% (95% confidence interval [CI], 2.5%-4.1%) for post-tonsillectomy bleeding in patients with normal coagulation studies. A rate of 8.7% (95% CI, 1.5%-15.9%) was obtained for bleeding in patients with abnormal coagulation studies. No significant rate difference in post-tonsillectomy bleeding was demonstrated.

CONCLUSION

There is no difference in the rate of post-tonsillectomy bleeding in patients with abnormal coagulation studies as compared with patients with normal coagulation studies obtained preoperatively.

The Hsp90 family of proteins in Arabidopsis thaliana

The 90-kDa heat shock protein (Hsp90) is an essential molecular chaperone in eukaryotic cells, with key roles in the folding and activation of proteins involved in signal transduction and control of the cell cycle. A search for Hsp90 sequences in the Arabidopsis thaliana genome revealed that this family includes 7 members. The AtHsp90-1 through AtHsp90-4 proteins constitute the cytoplasmic subfamily, whereas the AtHsp90-5, AtHsp90-6, and AtHsp90-7 proteins are predicted to be within the plastidial, mitochondrial, and endoplasmic reticulum compartments, respectively. The deduced amino acid sequences of each of the cytoplasmic proteins contains the highly conserved C-terminal pentapeptide MEEVD. All of the AtHsp90 sequences include a conserved adenosine triphosphate-binding domain, whereas only the cytoplasmic and endoplasmic reticulum-resident sequences include an adjacent charged linker domain that is common in mammalian and yeast sequences. The occurrence of multiple AtHsp90 proteins in the cytoplasm and of family members in other subcellular compartments suggests a range of specific functions and target polypeptides.

Hsp90-binding immunophilins in plants: the protein movers

Studies of cytoplasmic-nuclear trafficking of the glucocorticoid receptor in mammalian cells suggest that the hsp90/hsp70-based chaperone system and the hsp90-binding immunophilin FKBP52 are involved in targeted movement of the receptor along microtubule tracts. Over the past few years, plant cells have been found to possess a similar multiprotein chaperone machinery. Plant cells also contain high molecular weight FKBPs that bind to plant hsp90 via a conserved protein interaction involving tetratricopeptide repeat domains. The hsp90/hsp70-based machinery and the plant FKBPs might be used to target the trafficking of signalling proteins in plants.

A glucosinolate mutant of Arabidopsis is thermosensitive and defective in cytosolic Hsp90 expression after heat stress

The TU8 mutant of Arabidopsis previously described to be deficient in glucosinolate metabolism and pathogen-induced auxin accumulation was found to be remarkably less tolerant upon exposure to elevated temperatures than wild-type plants. Although moderately increased temperature only affected shoot growth, exposure to severe heat stress led to a dramatic decay of mutant plants. By contrast, wild-type seedlings showed little or no damage under the same conditions. Analysis of different heat stress proteins (Hsps) in TU8 seedlings revealed that only expression of cytoplasmic Hsp90 was affected in these plants. Although Hsp90 was present under control conditions, its level declined in mutant plants at elevated temperatures. Northern-blot analysis indicated that the decrease in Hsp90 protein was accompanied with a reduction of hsp90 transcript levels. Transient expression of Hsp90 in mutant protoplasts increased their survival rate at higher temperatures to near equivalent that of wild-type protoplasts. These data suggest that the reduced level of Hsp90 in TU8 mutants may be the primary cause for the observed reduction in thermostability.

Pediatric hemorrhagic thyroid nodule: a case report

Hemorrhagic thyroid nodules are rare in the pediatric age group. They present as rapidly enlarging neck masses. Diagnostic modalities available are laboratory evaluation, ultrasound, radionuclide imaging, and fine needle aspiration. Depending on the pattern of growth of the lesion, one may observe or proceed with surgery. A rapidly enlarging thyroid mass raises the suspicion of malignancy, and hemorrhagic nodules, though rare, must be considered in the differential diagnosis.

Treatment with 24-epibrassinolide, a brassinosteroid, increases the basic thermotolerance of Brassica napus and tomato seedlings

Brassinosteroids are plant growth-promoting compounds that exhibit structural similarities to animal steroid hormones. Recent studies have indicated that brassinosteroids are essential for proper plant development. In addition to a role in development, several lines of evidence suggest that brassinosteroids exert anti-stress effects on plants. However, the mechanism by which they modulate plant stress responses is not understood. We show here that Brassica napus and tomato seedlings grown in the presence of 24-epibrassinolide (EBR) are significantly more tolerant to a lethal heat treatment than are control seedlings grown in the absence of the compound. Since a preconditioning treatment of seedlings was not required to observe this effect, we conclude that EBR treatment increases the basic thermotolerance of seedlings. An analysis of heat shock proteins (HSPs) in B. napus seedlings by western blot analysis indicated that the HSPs did not preferentially accumulate in EBR-treated seedlings at the control temperature. However, after heat stress, HSP accumulation was higher in EBR-treated than in untreated seedlings. The results of the present study provide the first direct evidence for EBR-induced expression of HSPs. The higher accumulation of HSPs in EBR-treated seedlings raises the possibility that HSPs contribute, at least in part, to thermotolerance in EBR-treated seedlings. A search for factors other than HSPs, which may directly or indirectly contribute to brassinosteroid-mediated increase in thermotolerance, is underway.

Mass spectral study of substituted allyl aryl and allyl alkyl selenides and some analogous sulfides

The electron impact (EI) mass spectra of allyl aryl selenides showed abundant molecular ions and many fragment ions containing the selenium atom. alpha-Cleavage is the dominant process in the fragmentation of selenides, and cleavage product ions are characteristic of the substituents. In the case of 3-methyl allyl and related aryl selenides, characteristic delta-hydrogen migration to the selenium atom is observed. A McLafferty-type rearrangement is found in benzyl allyl selenides and substituted alkyl allyl selenides. The charge on the rearrangement products preferably remains on the fragments containing the phenyl group. The [M - SeH](+), [M - CH(3)](+) and [M - C(2)H(4)](+) ions are found only in the EI mass spectrum of allyl phenyl selenide, and are attributed to a Claisen rearrangement in the source of the mass spectrometer. All structurally informative fragmentation processes are supported by collision induced dissociation spectra of molecular ions. The fragmentation patterns found in methane chemical ionization (CI) spectra of the selenides were significantly different from those observed in EI. The EI and CI mass spectra of analogous sulfides showed similar behaviour to that observed in the corresponding selenides. Copyright 1999 John Wiley & Sons, Ltd.

High-molecular-weight FK506-binding proteins are components of heat-shock protein 90 heterocomplexes in wheat germ lysate

In animal cell lysates the multiprotein heat-shock protein 90 (hsp90)-based chaperone complexes consist of hsp70, hsp40, and p60. These complexes act to convert steroid hormone receptors to their steroid-binding state by assembling them into heterocomplexes with hsp90, p23, and one of several immunophilins. Wheat germ lysate also contains a hsp90-based chaperone system that can assemble the glucocorticoid receptor into a functional heterocomplex with hsp90. However, only two components of the heterocomplex-assembly system, hsp90 and hsp70, have thus far been identified. Recently, purified mammalian p23 preadsorbed with JJ3 antibody-protein A-Sepharose pellets was used to isolate a mammalian p23-wheat hsp90 heterocomplex from wheat germ lysate (J.K. Owens-Grillo, L.F. Stancato, K. Hoffmann, W.B. Pratt, and P. Krishna [1996] Biochemistry 35: 15249-15255). This heterocomplex was found to contain an immunophilin(s) of the FK506-binding class, as judged by binding of the radiolabeled immunosuppressant drug [3H]FK506 to the immune pellets in a specific manner. In the present study we identified the immunophilin components of this heterocomplex as FKBP73 and FKBP77, the two recently described high-molecular-weight FKBPs of wheat. In addition, we present evidence that the two FKBPs bind hsp90 via tetratricopeptide repeat domains. Our results demonstrate that binding of immunophilins to hsp90 via tetratricopeptide repeat domains is a conserved protein interaction in plants. Conservation of this protein-to-protein interaction in both plant and animal cells suggests that it is important for the biological action of the high-molecular-weight immunophilins.

Brassica napus hsp90 can autophosphorylate and phosphorylate other protein substrates

A Brassica napus cDNA encoding the 90 kDa heat shock protein, hsp90, was modified to add 6 histidines at the C-terminus and expressed in insect cells to prepare a recombinant histidine-tagged hsp90. The recombinant protein was purified over Ni2+-NTA agarose columns and its identity was confirmed by Western blotting, using a plant hsp90-specific antiserum. Incubation of purified hsp90 with [gamma-32P] ATP in the presence of Mn2+ resulted in its autophosphorylation on serine residues. The purified hsp90 could also phosphorylate other protein substrates such as histones and casein in the presence of Mn2+. Analysis of phosphorylated casein revealed that serine residues are phosphorylated by hsp90. This is the first demonstration that a cytosolic hsp90 homolog can phosphorylate other protein substrates.