Dem-Aging: autophagy-related pathologies and the "two faces of dementia".

Neuronal ceroid lipofuscinosis (NCL) is an umbrella term referring to the most frequent childhood-onset neurodegenerative diseases, which are also the main cause of childhood dementia. Although the molecular mechanisms underlying the NCLs remain elusive, evidence is increasingly pointing to shared disease pathways and common clinical features across the disease forms. The characterization of pathological mechanisms, disease modifiers, and biomarkers might facilitate the development of treatment strategies.The DEM-AGING project aims to define molecular signatures in NCL and expedite biomarker discovery with a view to identifying novel targets for monitoring disease status and progression and accelerating clinical trial readiness in this field. In this study, we fused multiomic assessments in established NCL models with similar data on the more common late-onset neurodegenerative conditions in order to test the hypothesis of shared molecular fingerprints critical to the underlying pathological mechanisms. Our aim, ultimately, is to combine data analysis, cell models, and omic strategies in an effort to trace new routes to therapies that might readily be applied in the most common forms of dementia.

The Minor's test in Frey syndrome treated with botulinum toxin: Methodology and efficacy.

In this paper, we aimed at methodologically presenting a video-case of Frey Syndrome occurred after parotidectomy, assessed by means of Minor's Test and treated with intradermic botulinum toxin A (BoNT-A) injection. Although largely described in the literature, a detailed explanation of both the procedures has not been previously elucidated. In a more original approach, we also highlighted the role of the Minor's test in identifying the most affected skin areas and new insight on the patient-tailored approach provided by multiple injections of botulinum toxin. Six months after the procedure, the patient's symptoms were resolved, and no evident signs of Frey syndrome were detectable through the Minor's test.

Primary stabbing headache: a new dural sinus stenosis-associated primary headache?

Primary stabbing headache (PSH) is a primary syndrome of unknown aetiology, characterised by brief, jabbing stabs predominantly felt in the orbital, temporal and parietal areas, whose frequency may vary from one to many per day, usually responding to indomethacin. PSH frequency in the general population is not well defined, but recent evidence suggests it could be more frequent than previously thought. In clinical series, PSH incidence was 33/100,000 per year, while in a population study 35.2 % prevalence was found. PSH was previously described as isolated or associated to other headache syndromes, most frequently with migraine. There is evidence that an idiopathic intracranial hypertension without papilledema, a condition usually associated to significant stenosis of dural sinuses (93 % sensitivity and specificity), is much more prevalent than believed and may run asymptomatically in up to 11 % of otherwise healthy individuals. In migrainous prone people, a sinus stenosis-associated intracranial hypertension without papilledema (ss-IHWOP) comorbidity may represent a powerful risk factor for progression of pain. Besides migraine, significant sinus stenosis has been found overrepresented also in chronic tension type headache as well as in exertional, cough, sexual activity-associated headaches (all indomethacin responsive primary headaches) and in altitude headache (an acetazolamide responsive condition). To explore the possible association between venous outflow disturbances and PSH, we retrospectively investigated the co-occurrence of sinus venous stenosis in patients referring to our headache centre since 2004 diagnosed with PSH who completed the diagnostic protocol. Out of 50 consecutive patients reporting PSH as the main or as accessory complaint, 8 (6 females, 2 males) performed MR venography (MRV). All MRV revealed significant unilateral or bilateral sinus stenosis. Mean age at PSH onset was 35.3 ± 18.9 years (range 11-67 years). Duration of attacks ranged 1-3 s. Median daily frequency of attacks was 4 (range 2-20); median number of days per month with PSH presentation was 14 (range 4-30). Six patients described attacks in temporal or parietal areas, one at the top of the head, and one in the occipital area. Only one patient had isolated PSH; all the others were diagnosed also with migraine without aura. Seven out of eight patients responded to indomethacin 75 mg/die, and one to topiramate 100 mg/die. Interestingly, both drugs share with acetazolamide a CSF pressure lowering effect. Our findings indicate that PSH is associated with central sinus stenosis and suggest that an undiagnosed ss-IHWOP might be involved in PSH pathogenesis.

Complete transmural gastric migration of PTFE mesh after surgery for a recurrent hiatal hernia.

Complications directly associated with the use of prosthetic materials in large hiatal hernia repair are rarely cited events in the literature. We herein report a case of a 47 year-old woman who came to our attention for a subacute onset of severe dysphagia and weight loss. She previously underwent laparotomic Nissen fundoplication with PTFE dual-mesh cruroplasty for a large recurrent hiatal hernia. With the clinical suspicious of "Tight Nissen", an endoscopy was performed and revealed a circular stenosis in the lower esophagus, a rotation of the stomach and, surprisingly, the presence of PTFE mesh free-moving in the gastric lumen With the use of rattooth forceps, the foreign body was removed and, after few days, the patient underwent a surgical debridement of hiatal scar tissue and a gastropexy procedure. In conclusion, dysphagia may manifest during the early postoperative period after mesh repair antireflux surgery, but such dysphagia usually resolves; if it doesn't or if it worsens, mesh migration must be excluded.

Cobalt, chromium and molybdenum ions kinetics in the human body: data gained from a total hip replacement with massive third body wear of the head and neuropathy by cobalt intoxication.

INTRODUCTION: A patient with a total hip replacement developed optic, acoustic and peripheral neuropathy from metal ions intoxication, due to the wear products released from the prosthesis. Subsequently the kinetics of the metal ions was studied. MATERIALS AND METHODS: Massive wear and acute intoxication allowed a study of the metal ions kinetics and of EDTA treatment. RESULTS: Plasma and other organic fluids were saturated by each of the metal ions released from the exposed surface according to the solubility of each ion; a larger fraction of Co ions was bound within red cells, while the plasmatic fraction appeared more movable. In a patient with a prosthesis subjected to wear, the ions released are from the prosthetic and from the debris surface (spread in the body). The latter is a function of the number and size of particles. DISCUSSION: Revision of the prosthesis from the point of view of the metal ions kinetics corresponded to a reduction of the releasing surface because of debris washed out by irrigation and tissue excision; however, the metal particles spread by lymphatic circulation continued to release ions even though the source of wear had been removed. Early diagnosis of high metal wear can be ascertained with mass spectrometry and after revision high levels of metal ions can only be reduced with repeated chelating treatment. It is preferable not to revise fractured ceramic components with a polyethylene-metal articulation.

Progress in endoscopic imaging of gastrointestinal tumors.

STATE OF THE ART: New technologies in the form of high-magnification or "zoom" endoscopy complemented by chromoscopic agents or Narrow Band Imaging permit early detection of neoplastic lesions, particularly flat and depressed types. Detailed characteristics of the mucosal surface can be obtained, enabling an in vivo "optical biopsy" to make an instant diagnosis at endoscopy, previously possible only by using histological or cytological analysis. Advances in fiber optics, light sources, detectors, and molecular biology have led to the development of several novel methods for tissue evaluation in situ. PERSPECTIVES: Promising imaging techniques include fluorescence endoscopy, optical coherence tomography, confocal microendoscopy, molecular imaging, and light scattering and Raman spectroscopy. CONCLUSIONS: These techniques probably are able to replace conventional biopsy in the near future, but the endoscopists should become increasingly more familiar with histopathologic findings.

Predictive role of audiological and clinical features for functional results after stapedotomy.

OBJECTIVE: To analyze and compare the preoperative factors that potentially influence the outcome of stapedotomy in our study group. MATERIALS AND METHODS: 161 cases were enrolled. Clinical variables considered to influence functional results - air conduction (AC) and bone conduction (BC) pure-tone average (PTA), air-bone gaps (ABG), sensorineural hearing loss (SNHL), ABG gain and DeltaSNHL - were gender, age, case type (unilateral vs. bilateral), ear side (right vs. left), pregnancy, vascular disease and family history of otosclerosis. The audiometric variables were preoperative AC- and BC-PTA, SNHL and ABG. RESULTS: Univariate logistic regression analysis showed that the probability of obtaining a > or =10 dB gain is significantly affected by the following factors: age <50 years, AC-PTA > or =50 dB and preoperative ABG > or =30 dB. All the other factors included into the registration (gender, familiarity, side, bilateral vs. unilateral, pregnancy, vascular diseases and preoperative BC-PTA) were not found to significantly affect postoperative gain (p > 0.05). Nevertheless, multivariate logistic regression analysis maintained a statistically significant correlation only between gain > or =10 dB and both preoperative ABG > or =30 dB and age <50 years. CONCLUSIONS: The accurate knowledge of predictive factors is a valuable tool that permits the surgeon to plan surgery with a better case selection as well as assisting in counseling the patient with regard to the likelihood of success of the procedure.

Multiple viral genome search in endolabyrinthic fluids of profoundly deaf patients: possible cytomegalovirus intracochlear reactivation.

BACKGROUND: The cause of about 30% of bilateral sensorineural hearing loss (SNHL) is still unknown. A viral etiology is among the most frequently proposed ones and the supposed diagnosis is only based upon few clinical and laboratory data. The detection of viral presence within a damaged compartment may represent a way to supply interesting data for confirmation of viral etiology and to explain pathogenic mechanisms. OBJECTIVES: The aim of our study was to identify the possible presence of pathogenic viruses in the inner ear extracellular compartment in patients with bilateral severe sensorineural deafness of unknown etiology who underwent cochlear implant surgery. METHODS: 4 patients, aged from 2 to 7 years and affected by SNHL underwent cochlear implantation surgery and, at the same time, endolabyrinthine fluid sampling. The samples were subsequently sent for viral nucleic acid extraction and polymerase chain reaction (PCR) treatment: multiplex PCR and realtime-PCR were used. In each endolabyrinthine fluid sample, cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella-zoster virus (VZV), herpes simplex virus type 1 and 2 (HSV-1, HSV-2) and enterovirus genomes were searched for. RESULTS: One patient was positive for intracochlear CMV, as confirmed by another base-pair segment PCR. EBV, VZV, HSV and enterovirus were detected in none of the 4 patients. CONCLUSIONS: Our finding of CMV genome within the cochlea of a deaf patient without any evidence of acute and prenatal CMV infection suggests its possible role in postnatal inner ear injury through reactivation of latent virus within the cochlea. This hypothesis could also be considered valid for some patients with anti-CMV-IgG-positive serology and absence of endolabyrinthine viral genome since viruses can be in an inactive state at the time of fluid collection. PCR has proved to be a very useful tool in order to investigate infectious causes of deafness even for more than one virus type at a time and in a limited quantity of sample, such as the small volume of endolabyrinthine liquid collected from children during cochlear implant surgery.

The prevalence of dysphonia and dysphagia in patients affected by immunomediated diseases and the role of psychometric tests.

This cross-sectional investigation examined the prevalence and severity of dysphonia, globus pharyngeus, and dysphagia in patients affected by immunomediated (IM) diseases. Seventy subjects were administered the Voice Handicap Index (VHI) (scale 0-4), Glasgow-Edinburgh Throat Scale (GETS) (scale from 0 to 7) for globus pharyngeus assessment, and modified Swallowing Outcomes After Revised Laryngectomy (SOAL) (scale 0, 1, 2) to test swallowing symptoms. VHI: the mean percentage of answers with a score greater than 1 (corresponding to a frequency of situation's occurrence "sometimes," "almost always," or "always") was 25.7, 26.7, and 44.1% for functional, emotional, and physical groups of sub-items respectively. GETS: the mean percentage of answers with a score ≥ 3 was 60.85%, significantly higher if compared with that of answers with a score < 3 (40.14%). The mean percentages of answers with a score 0-2, 3-4, and 5-7 were 40.1, 16.7, and 43.7% respectively. SOAL: a mean of 57.9% of answers gained a symptomatic score (1 ["a little"] or 2 ["a lot"]) and 41.9%, the score 0. The difference was statistically significant (p < 0.05). The first two most recurrent items with a score 2 ("a lot") were "Do you have a problem swallowing dry food?" (46%) and "Do you have a problem swallowing solid food?" (36%). The study represents the first to describe the globus pharyngeus symptoms in IM population. Moreover, it allows to confirm the recurrence of dysphonia and dysphagia in this type of patients. Particularly, it has been demonstrated that the alteration of swallowing function is related to solid and dry food. The self-assessment questionnaires proved as a useful tool to early detection of dysfunctions in order to avoid further deterioration of quality of life and to prevent serious life-threatening complications.

Post-surgical role of botulinum toxin-A injection in patients with head and neck cancer: personal experience.

Personal experience is discussed in the use of botulinum neurotoxin injections into both parotids, performed in order to transiently reduce salivation in patients undergoing major ablative and ablative-reconstructive oncologic surgery for head and neck tumours. Overall, 8 adult patients (2 female, 6 male) have been treated. Six cases were affected by pharyngocutaneous fistulas, one by severe sialorrhoea and one recurrent sialocele. After the injection, patients were regularly observed at follow-up and asked to give their subjective assessment of salivary flow. Investigations concerning possible complaints, including side-effects, as well as complete examination of the head and neck area were performed. Follow-up periods ranged from 12 to 24 weeks (mean 20 weeks). Following botulinum neurotoxin injection, the fistula was dry after a mean period of 4.5 days (min 3 days, max 8 days) and was closed 6.6 days (min 5 days, max 8 days) later. The patient affected by severe hypersalivation reported subjective improvement in sialorrhoea 4 days post-treatment. The patient affected by recurrent sialocele, required only one aspiration of fluid two days after the treatment, after which there were no further problems. Post-operative saliva-related complications significantly increase patient morbidity and hospital stay after major tumour surgery. The easy, safe and effective treatment with botulinum neurotoxin injection, observed in our experience, suggest its significant role as a useful option in the post-operative saliva-related complications.

OnabotulinumtoxinA for adductor spasmodic dysphonia (ADSD): Functional results and the role of dosage.

OBJECTIVE: To report the results of functional outcome, dose trend and relationship between onabotulinumtoxinA (onabotA) dosage and the severity of disease or time between therapy sessions in patients affected by adductor spasmodic dysphonia (ADSD). PATIENTS AND METHODS: Thirty-two patients underwent 193 EMG-guided intracordal injections of a starting dose of 2 MU of onabotA. At enrollment, each subject was administered the VHI. The response was evaluated using a subjective rating scale (0-100% of normal phonation). RESULTS: The quality of voice improved significantly after 1 month and stabilized by 3 months. The percentage of normal voice improved 33.34 ±â€¯11.5% (min 26 - max 68). The functional gain was significantly worse in patients presenting with ADSD associated with dystonias in other body regions (31% vs 45% - p < 0.05). The mean dose employed was 3.64 MU (min 1 - max 6) with a trend of increasing dosages up to the 5th treatment after which the doses stabilized over time. The pre-treatment VHI showed a weakly positive correlation with the cumulative dose at the 5th and 10th injections. Benefit duration and the mean between treatment interval were 103 and 136 days respectively. The correlation between dose and inter-injection time is weakly negative (r = -0.22, p < 0.05), however, this is influenced predominantly by the first-to-second injection. After this initial treatment effect, the correlation becomes weakly positive (r = 0.12). CONCLUSIONS: Our data confirm the efficacy of onabotA to improve the quality of voice in cases of ADSD. The trial period for optimal dosage lasted up to a mean of five injections. The dosage of onabotA impacted the length of response and was influenced by the severity of ADSD. Finally the efficacy of onabotA did not change significantly after repeated administrations.

Synovial procollagenase activation by human mast cell tryptase dependence upon matrix metalloproteinase 3 activation.

Mast cells have been implicated in the pathogenesis of the matrix degradation observed in the cartilaginous and osseous structures of the rheumatoid joint. We previously reported that human mast cell tryptase, a 134-kD granule-associated neutral protease, is present in rheumatoid synovium and can activate collagenase in crude culture medium in vitro. the present study attempts to depict the precise mechanism of this activation. To express full activation of latent collagenase, matrix metalloproteinase 3 (MMP-3) or stromelysin, can be activated by tryptase in a time and dose-dependent manner. Tryptase was not capable of generating active collagenase in the crude media from cultured rheumatoid synoviocytes depleted of proMMP-3 by immunoadsorption. In addition, the function of the tissue inhibitor of metalloproteinases (TIMP) was not altered by tryptase, and SDS-PAGE analysis revealed no degradation of TIMP by tryptase. The tryptase dependent activation of synoviocyte procollagenase thereby appears to be entirely dependent upon its ability to activate proMMP-3.

Human mast cells stimulate vascular tube formation. Tryptase is a novel, potent angiogenic factor.

The presence of mast cells near capillary sprouting sites suggests an association between mast cells and angiogenesis. However, the role of mast cells in blood vessel development remains to be defined. In an attempt to elucidate this relationship, we investigated the effect of human mast cells (HMC-1) and their products on human dermal microvascular endothelial cell (HDMEC) tube formation. Coculture of HMC-1 with HDMEC led to a dose-response increase in the network area of vascular tube growth. Moreover, the extent of neovascularization was enhanced greatly when HMC-1 were degranulated in the presence of HDMEC. Further examination using antagonists to various mast cell products revealed a blunted response (73-88% decrease) in the area of vascular tube formation if specific inhibitors of tryptase were present. Tryptase (3 microg/ml) directly added to HDMEC caused a significant augmentation of capillary growth, which was suppressed by specific tryptase inhibitors. Tryptase also directly induced cell proliferation of HDMEC in a dose-dependent fashion (2 pM-2 nM). Our results suggest that mast cells act at sites of new vessel formation by secreting tryptase, which then functions as a potent and previously unrecognized angiogenic factor.

Flexible endoscopic Zenker's diverticulotomy: cap-assisted technique vs. diverticuloscope-assisted technique.

BACKGROUND AND STUDY AIM: The standard treatment for a Zenker's diverticulum is diverticulotomy, either using the endostapling approach or by surgery. Flexible endoscopic diverticulotomy has similar efficacy and is associated with fewer complications but this technique is still under investigation. The aim of this study was to compare the technical results and efficacy of two flexible endoscopic diverticulotomy techniques. PATIENTS AND METHODS: A total of 39 patients with a Zenker's diverticulum were treated using either cap or diverticuloscope assistance to expose the septum, which was then cut with a needle-knife and endocut currents. The severity of symptoms was graded according to their frequencies before the procedure, after 1 month, and to June 2006. RESULTS: Of the 39 patients enrolled into the study, 28 patients were treated with the cap and 11 with the diverticuloscope, the two groups showing no statistical difference in baseline features. The median length of the Zenker's diverticulum was 4 cm (range 2-8 cm). The procedure time was significantly longer with the cap than with diverticuloscope assistance (P = 0.002). Complications occurred in 9/28 patients in the cap group and in none of the patients in the diverticuloscope group (P = 0.04); the perforations that occurred in five patients (18%) were managed endoscopically and conservatively. The median inpatient stay was 3 days (range 2-8 days). The clinical remission rate, evaluated using a pool of symptoms, was significantly higher after the diverticuloscope-assisted procedure compared with the cap technique (82% vs. 29%, P = 0.004). Multivariate analysis showed that the diverticuloscope-assisted technique was the only significant prognostic factor for efficacy (odds ratio 13.09, 95% CI 2.07-82.53). CONCLUSION: The use of the soft diverticuloscope to expose and fix the septum seems to be the optimal approach in terms of increasing the safety and clinical efficacy of flexible endoscopic diverticulotomy.

Capsule endoscopy in patients with chronic abdominal pain.

BACKGROUND: Patients with chronic abdominal pain consult gastroenterologists frequently, requiring a large number of examinations. AIM: To assess the diagnostic yield of capsule endoscopy in patients with chronic abdominal pain of unknown origin and negative diagnostic work-up. PATIENTS: From January 2002 to September 2004, 16 patients (10 female; mean age 42.7 years) who complained of chronic abdominal pain were referred to our unit for capsule endoscopy. METHODS: Chronic abdominal pain was defined as continuous or almost continuous, for at least 3 months and without criteria for other gastrointestinal disorders. All patients had a previous diagnostic work-up including abdominal ultrasonography, oesophagogastroduodenoscopy, colonoscopy and small bowel follow through, performed within 2 months. RESULTS: Capsule endoscopy was normal in 12 patients (75%). Small bowel abnormalities were found in three patients, but were considered irrelevant. In one patient (6.3%), capsule endoscopy revealed ileal erosions and inflammation and was retained in a stricture undetected by radiology. This patient underwent elective surgery which revealed an ileal carcinoid neoplasm. CONCLUSIONS: Capsule endoscopy identified a specific cause of chronic abdominal pain in only one patient. Capsule endoscopy is a safe procedure but does not seem to play an important role in the evaluation of patients with chronic abdominal pain of unknown origin.

Advanced giant cell reparative granuloma of the mandible: radiological features and surgical treatment.

Giant cell reparative granuloma accounts for 1%-7% of all benign lesions of the jaw. Giant cell reparative granuloma often arises in the mandible and in the maxilla and affects children and young adults. It is usually a slow-growing lesion, fast-growing lesions having rarely been reported. The latter, despite the innocent histological appearance, has an aggressive behaviour mimicking a malignant lesion. In the present report the clinical features of an aggressive variety of giant cell reparative granuloma in a 21-year-old female are described focusing on the dental findings at computed tomography and surgical treatment.

The role of masseter muscle EMG during DISE to predict the effectiveness of MAD: preliminary results.

The use of a mandibular advancement device (MAD) increases the activity of the temporo-mandibular (TM) complex and masseter (MM) muscles with the risk of reducing treatment compliance. Predictors of treatment outcome are of importance in selecting patients who might benefit from MAD without side effects. The role of mandibular advancement (MA) during drug-induced sleep endoscopy (DISE) is controversial. In three cases (BMI < 30) affected by non-severe OSAS (AHI < 30 e/h), we recorded the surface EMG signal of MM activity during DISE. At follow-up all cases improved the AHI, two cases that showed transient increase of MM activity did not suffer from changes of overjet and did not complain of discomfort with the use of MAD. The case that showed a continuing increase of MM activity reported TM discomfort without changes of dental occlusion. EMG of MM during DISE may contribute to ameliorate the selection of cases amenable to treatment with MAD.

Treatment of v-Ki-ras-transformed SVC1 cells with low retinoic acid induces malignancy reversion associated with ras p21 down-regulation.

The effect of nontoxic, low concentrations (10(-8) M) of retinoic acid (RA) for a relatively long time (28 days) on a Kirsten ras-virus transformed cell line (Ki-SVC1), derived from the rat seminal vesicle epithelium, was investigated. In these experimental conditions, the cell treatment with RA induced a decrease of the proliferation rate, apoptosis and a marked reduction of both anchorage-independent growth and tumorigenicity. These biological responses were either preceded or associated with important changes in adenylate cyclase/protein kinase C signaling pathways, the activation of important apoptosis-linked genes and a marked decrease of the v-Ki-ras p21 protein. The significance of these findings is discussed.

Drug-induced sleep endoscopy as a selection tool for mandibular advancement therapy by oral device in patients with mild to moderate obstructive sleep apnoea.

Nowadays oral appliance therapy is recognised as an effective therapy for many patients with primary snoring and mild to moderate obstructive sleep apnoea (OSA), as well as those with more severe OSA who cannot tolerate positive airway pressure (PAP) therapies. For this reason, it is important to focus on objective criteria to indicate which subjects may benefit from treatment with a mandibular advancement device (MAD). Various anthropometric and polysomnographic predictors have been described in the literature, whereas there are still controversies about the role of drug-induced sleep endoscopy (DISE) and advancement bimanual manoeuvre as predictor factors of treatment outcome by oral device. Herein, we report our experience in treatment of mild moderate OSA by oral appliance selected by DISE. We performed a single institution, longitudinal prospective evaluation of a consecutive group of mild moderate patients with obstructive sleep apnoea syndrome who underwent DISE. During sleep endoscopy, gentle manoeuvre of mandibular advancement less than 5 mm was performed. In 30 of 65 patients (46.2%) we obtained an unsuccessful improvement of airway patency whereas in 35 of 65 patients (53.8%) the improvement was successful and patients were considered suitable for oral device application. Because 7 of 35 patients were excluded due to conditions interfering with oral appliance therapy, we finally treated 28 patients. After 3 months of treatment, we observed a significant improvement in the Epworth medium index [(7.35 ± 2.8 versus 4.1 ± 2.2 (p < 0.05)], in mean AHI [(21.4 ± 6 events per hour versus 8.85 ± 6.9 (p < 0.05)] and in mean ODI [(18.6 ± 8 events per hour to 7 ± 5.8 (p < 0.05)]. We observed that the apnoea/hypopnoea index (AHI) improved by up to 50% from baseline in 71.4% of patients selected after DISE for MAD therapy. In the current study, mandibular advancement splint therapy was successfully prescribed on the basis not only of severity of disease, as determined by the subject's initial AHI, but also by DISE findings combined with results of gentle mandibular advancement manoeuvre allowing direct view of the effects of mandibular protrusion on breathing spaces in obstruction sites, and showing good optimisation of selection of patients for oral device treatment.

The differentiation and function of myofibroblasts is regulated by mast cell mediators.

Myofibroblasts are fibroblasts that express certain features of smooth muscle differentiation. Increased numbers of myofibroblasts and mast cells are frequently found together in a wide variety of settings, such as normal wound repair and scleroderma skin, which suggests that mediators produced by the mast cells could play a role in the regulation of myofibroblast differentiation and function. We used a human mast cell line, HMC-1, to determine if mast cells can induce normal human dermal fibroblasts to differentiate into functional myofibroblasts in vitro. We monitored the differentiation process by assaying two properties of the myofibroblast phenotype: expression of alpha-smooth muscle actin and functional capacity to contract a collagen matrix. In both a simple coculture system and in a skin-equivalent culture system, HMC-1 cells induced alpha-smooth muscle actin expression by fibroblasts. HMC-1 cells also stimulated fibroblast contraction of collagen gels, and the relative amount of contraction was dependent upon the number of HMC-1 cells present. To characterize the individual contributions made by specific mast cell products, we examined the effects of histamine, tumor necrosis factor alpha, and tryptase. Histamine induced a clear increase in alpha-smooth muscle actin expression, but it did not appear to stimulate fibroblast contraction. Tumor necrosis factor alpha had no effect in either assay. Purified human tryptase induced alpha-smooth muscle actin expression, and blocking the proteolytic activity of tryptase with specific inhibitors reduced that response. Tryptase inhibitors also eliminated the ability of HMC-1 cells to stimulate fibroblast contraction, suggesting that tryptase secreted by the HMC-1 cells may be one of the active mast cell mediators.