Effects of random and systematic perturbations in a one-dimensional photonic crystal wavelength converter

We study the problem of the tolerance to fabrication errors in one-dimensional photonic crystal wavelength converters. In particular we consider the case of wavelength conversion obtained via quasiphase matching (QPM) based on a periodic amplitude modulation of the fundamental wave (Bloch-mode-QPM). Both numerical simulations of a waveguide-based structure and experimental results in an AlGaAs thin-film multilayer show that the proposed QPM mechanism is extremely tolerant to both systematic and random errors in the periodicity and duty cycle of the grating.

Efficacy of tizanidine hydrochloride in the treatment of myofascial face pain

AIM

The aim of the present investigation was to evaluate the usefulness of tizanidine hydrochloride in the treatment of myofascial pain of the masticatory muscles.

METHODS

This work is a preliminary report of clinical experience with the use of tizanidine hydrochloride at the Section of Prosthetic Dentistry, Department of Neuroscience, University of Pisa, Pisa, Italy. During the period from January 2000 to March 2003, 145 patients were given Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) axis I group I diagnosis of myofascial pain in the absence of any painful temporomandibular joint condition. Seventy-eight subjects agreed to suspend any kind of treatment they had undergone and to start assuming tizanidine hydrochloride (SIRDALUD) 4 mg/die per os (2 2- mg tablets a day, 1 in the morning and 1 after dinner) for 2 weeks. All underwent a clinical assessment according to RDC/TMD guidelines at baseline time and were re-evaluated at the end of the treatment period.

RESULTS

At the end of the treatment period all patients had improved; 42/78 patients (53.8%) showed absence of clinical symptoms; 18/78 (23.1%) showed a good improvement, still presenting a low number of painful sites, but not satisfying RDC/TMD parameters for diagnosis of myofascial pain; 18/78 (23.1%) showed only a slight improvement, still presenting a high number of painful sites and satisfying RDC/TMD parameters for diagnosis of myofascial pain.

CONCLUSION

Given the absence of papers on the use of tizanidine hydrochloride in the treatment of myofascial pain of the masticatory muscles, the present investigation could provide some preliminary data about its possible efficacy. Randomized and controlled clinical trials are needed to confirm these results.

Etiopathogenesis of parafunctional habits of the stomatognathic system

A broad consensus does exist among main authors on the importance of parafunctional habits in the etiopathogenesis of temporomandibular disorders (TMD). Mechanisms through which an intense parafunctional activity determined a pathological effect on the temporomandibular joints (TMJs) and their related structures have still not been definitively clarified; nevertheless, before investigating those mechanisms, it's useful to study predisposing, triggering and/or worsening factors of parafunctions themselves. At present the theory, once widely accepted, according to which occlusal interferences can trigger a muscular hyperactivity through the activation of periodontal receptors, has lost a lot of credit. Recently, the hypothesis that bruxism and other parafunctions have a central etiology has become more and more accepted. In such a context, the role of the psychic component assumes a strong relevance, particularly for its relation with the limbic system, which is the part of the central nervous system (CNS) that regulates emotions. Such a hypothesis is confirmed by clinical practice, but it doesn't explain why some patients have reported a worsening of parafunctional activities after occlusal adjustment. The aim of this study is to investigate this issue through a critical review of the literature, indicating how the 2 theories might be complementary for the development and worsening of a parafunctional habit. From this review, despite the number of clinical opinions, there emerges a lack of methodologically appropriate associative works and controlled clinical trials which consent to clarify the effective importance of psychic and/or occlusal factors in the etiopathogenesis of parafunctional habits.

A spectrum approach for the assessment of manic-depressive symptoms accompanying temporomandibular disorders

AIM

Temporomandibular disorders (TMD) are a number of conditions which are frequently associated with depressive symptoms, but the possible existence of some form of manic-depressive illness in TMD patients has never been investigated. The aims of this work were to evaluate the reliability of a newly adopted spectrum model of psychopathology to detect depressive symptoms in TMD patients, and to produce pilot data on the presence of manic symptoms in TMD patients.

METHODS

Ninety-one consecutive TMD patients (72 females, 19 males; mean age 26.3) and 26 TMD-free subjects (21 females, 5 males; mean age 24) were administered a validated questionnaire to evaluate mood spectrum (MOODS-SR). Helkimo's Clinical Dysfunction Index (CDI) was calculated for all patients. One-way ANOVA and Bonferroni's post-hoc test for multiple comparisons were used to compare mean MOODS-SR scores of the groups identified as TMD-free (CDI=0), mild dysfunctionals (CDI=1), moderate or severe dysfunctionals (CDI= or >2).

RESULTS

Total scores of domains evaluating depression were significantly higher in moderate or severe dysfunctionals than in both TMD-free (mean difference 8.87+/-3.5; p=0.017) and mild dysfunctionals (m.d. 9.41+/-2.62; p=0.001). As regards manic symptoms, differences between groups were not significant (F=1.299; p=0.277).

CONCLUSION

Our findings support the reliability of MOODS-SR to detect depressive symptoms associated with TMD. The hypothesis that depressive symptoms in TMD patients could be an expression of a more complex manic-depressive illness has to be rejected, since no differences between TMD patients and TMD-free subjects have been revealed for the presence of manic symptoms.

Nuclear localisation of p65 in sputum macrophages but not in sputum neutrophils during COPD exacerbations

BACKGROUND

Exacerbations represent an important feature of the clinical manifestation and natural history of chronic obstructive pulmonary disease (COPD). Nuclear localisation of p65 is a signal of nuclear factor-kappaB (NF-kappaB) activation. A study was undertaken to evaluate whether NF-kappaB activation is modified in sputum cells during COPD exacerbations.

METHODS

Total and nuclear p65 immunoreactivity was measured by immunocytochemistry in the sputum cells of 11 smokers with moderate COPD during an exacerbation and after 6-8 weeks of clinical stability.

RESULTS

Total sputum cell count was significantly increased during exacerbations from a median (IQR) of 880 (510-1865) to 1914.5 (1065-3205) x 10(3)/ml (p<0.05). The main inflammatory cells in the sputum were neutrophils (83.2 (75.4-92.3)%) and macrophages (14.7 (2.6-21.6)%) and their relative proportion did not change during exacerbations. Nuclear staining for p65 was absent in sputum neutrophils, both during exacerbations and in the stable phase. In contrast, the percentage of macrophages expressing nuclear p65 increased significantly during exacerbations from a median (IQR) of 16 (7-24)% to 41.4 (6-69)% (p<0.05).

CONCLUSIONS

NF-kappaB appears to be activated in sputum macrophages but not in sputum neutrophils during exacerbations of COPD

Early interception of skeletal-dental factors predisposing to temporomandibular disorders during child development

Temporomandibular disorders (TMD) comprise a heterogoneous group of pathologies or dysfunctions of the temporomandibular joints and their related neuromuscular systems. The multifactoral etiology of these disorders raises serious diagnostic and therapeutic problems. A modern approach demands close collaboration between a number of specialists in order to create the best possible treatment plan. The progressive nature of certain forms of TMD, combined with the major advantages deriving from early treatment, encourage the dental surgeon to carry out early interception of all those dental and/or skeletal anomalies which may determine the dysharmonic function and development of the facial mass, even though such anomalies may not represent the sole causes of the various forms of TMD. The general practitioner, and to an even greater extent the pediatrician, may therefore play a role of primary importance as those medical influences capable of early detection of TMD risk situations.

Eosinophilic inflammation in sputum of poorly controlled asthmatics

Despite full effective treatment, asthmatic patients often present with poorly controlled asthma. Airway eosinophilia is associated with asthma, but its relationship with asthma control is still undetermined. To investigate the relationship between airway eosinophilia and asthma control, cellular and biochemical markers of airway inflammation were measured in 19 subjects with poorly controlled asthma, 16 subjects with asthma under control and eight normal volunteers. The severity of asthma was mild-to-moderate persistent in 23 patients (14 poorly controlled) and severe prednisone-dependent in 12 subjects (five poorly controlled). Induced sputum was analysed for total and differential cell counts, leukotriene E4 (LTE4), eosinophil cationic protein (ECP), regulated on activation, normal T-cell expressed and secreted (RANTES), and interleukin (IL)-8. Sputum eosinophils, LTE4, ECP and RANTES levels (but not IL-8) were significantly higher in patients with poorly controlled asthma as compared to patients with controlled asthma. By contrast, sputum cells and sputum inflammatory markers were not different among groups of patients with different severity of asthma. These results suggest that sputum eosinophilia is associated with poorly controlled asthma rather than with the severity of asthma.

[Histological and ultrastructural characteristics of jaw-closing muscles. A review]

The aim of this work is giving, through a wide literature review, a detailed analysis of the histological and ultrastructural characteristics that distinguish masseter and temporal muscles from the other skeletal muscles. Furthermore we'll explain the functional meanings of these differences. We developed the following points: fibre type composition and relative frequency of the various fibre types, fibre size, myosin composition, capillarization and age-related changes. With standard staining method for the myofibrillar ATPase, besides the two main fibre types, I and II, in the masticatory muscles a moderate share of IM fibres with intermediate stainability, which usually don't appear in adult skeletal muscles, are shown. The relative frequency of the various fibre types is also peculiar, with a prevalence of type I fibres in almost every portion of the masseter and temporal muscles, which therefore are functionally slow muscles. Another unusual characteristic is also the mean diameter of type I fibres, that are commonly larger than type II fibres. This finding suggests that masticatory muscles are adapted to carry out specially prolonged and fatiguing tasks. The findings about contractile protein patterns and the changes in myosin heavy chain composition during ageing are also relevant. The deep differences between jaw-closing and limb and trunk muscles are reviewed on the basis of their special functional activities.

The intriguing association between prematurity and neonatal isolated submandibular suppurative sialadenitis

Submandibular suppurative sialadenitis occurring as an isolated lesion in the neonatal period is extremely rare. A case of a preterm newborn, who developed an isolated submandibular suppurative sialadenitis is described. A literature review highlighting salient points on this topic is also presented. In particular, an important role of prematurity in the etiology of this pathological condition is shown and discussed.

Evaluation of a reformulated CHROMagar Candida

CHROMagar Candida is a differential culture medium for the isolation and presumptive identification of clinically important yeasts. Recently the medium was reformulated by Becton Dickinson. This study was designed to evaluate the performance of the new formula of CHROMagar against the original CHROMagar Candida for recovery, growth, and colony color with stock cultures and with direct plating of clinical specimens. A total of 90 stock yeast isolates representing nine yeast species, including Candida dubliniensis, as well as 522 clinical specimens were included in this study. No major differences were noted in growth rate or colony size between the two media for most of the species. However, all 10 Candida albicans isolates evaluated consistently gave a lighter shade of green on the new CHROMagar formulation. In contrast, all 26 C. dubliniensis isolates gave the same typical dark green color on both media. A total of 173 of the 522 clinical specimens were positive for yeast, with eight yeast species recovered. The recovery rates for each species were equivalent on both media, with no consistent species-associated differences in colony size or color. Although both media were comparable in performance, the lighter green colonies of C. albicans isolates on the new CHROMagar made it easier to differentiate between C. albicans and C. dubliniensis isolates. In conclusion, the newly formulated Becton Dickinson CHROMagar Candida medium is as equally suited as a differential medium for the presumptive identification of yeast species and for the detection of multiple yeast species in clinical specimens as the original CHROMagar Candida medium.

Partial reversibility of airflow limitation and increased exhaled NO and sputum eosinophilia in chronic obstructive pulmonary disease

We investigated the relationship between the reversibility of airflow limitation, the concentration of nitric oxide (NO) in exhaled air, and the inflammatory cells in the sputum of patients with stable chronic obstructive pulmonary disease (COPD). We examined nine normal healthy control subjects and 20 nonatopic patients with COPD. Ten patients had no reversibility of airflow limitation (increase in FEV(1) of < 12% and < 200 ml after 200 microg of inhaled salbutamol), and 10 patients had partial reversibility of airflow limitation (increase in FEV(1) of < 12% but > 200 ml after 200 microg of inhaled salbutamol). Exhaled NO levels were higher in COPD patients with partial reversibility of airflow limitation than in those with no reversibility of airflow limitation (median 24 [interquartile range 15.3 to 32] ppb versus 8.9 [4.6 to 14.7] ppb; p < 0.01). Compared with healthy control subjects, only COPD patients with partial reversibility of airflow limitation had increased concentrations of sputum eosinophils. We conclude that, in patients with stable COPD, even a partial bronchodilator response to inhaled salbutamol is associated with increased exhaled NO and sputum eosinophilia, suggesting that these patients may have a different response to treatment than do those without reversible airflow limitation.

[Indications for selective arterial embolization in the treatment of epistaxis]

After posterior packing has failed, the treatment of choice for severe, recurrent posterior epistaxis is arterial ligature, usually through a transantral approach to the Internal Maxillary artery (LTA) or selective percutaneous embolization (EP). The advantages and disadvantages of each technique are discussed by various Authors. A critical review of the literature brings to light the discrepancies between the results of various studies: in a series by Strong et al. and in a review of the literature EP proved more effective than LTA (90-94% vs. 85-89%). On the contrary, using personal data Cullen and Tami reported that the results are analogous. As regards complications, these proved slightly more frequent, but minor, with LTA while the rare complications with EP were more serious. The per-patient costs fundamentally depend on the type of hospital management and the availability of a treatment center; the results of the various studies are not analogous in this regard. The specific indications for the choice of which technique to use include: LTA: ethmoid artery hemorrhage, severe arteriosclerosis of the carotid compartment and allergy to the contrast medium; EP: cardiovascular instability, severe anemia and all conditions which are contraindications for general anesthesia. In the cases studied by the Authors, of the total 203 patients admitted to hospital for posterior epistaxis between May 1995 and November 1999, 12 (5.9%; on the average 2.6 pt/yr) showed values lower than those found at other Centers. A total of 13 EP procedures were performed and the result was positive (stopping the hemorrhage) in 11 (91.7%). In one post-traumatic case there was a recurrence which could not be controlled by EP and thus the Authors resorted to surgical ligature. All the patients underwent fibroscopy after the posterior packing was removed and before establishing the indications for EP. A full 50% of the patients treated showed arterial hypertension and in all patients except the one with multiple traumas, the pre-embolization angiography showed the presence of submucosal teleangiectasia in the site of the epistaxis. This report supports the hypothesis that, in the presence of triggering factors (hypertension, pregnancy), untreatable epistaxis is sustained by a submucosal vascular malformation. On the other hand, it also asserts that although the patient evaluation to determine the EP treatment was less invasive than that used in other Centers, it was able to identify the patients with this malformation, thus validating the clinical criteria used.

Time-domain Fourier optics for polarization-mode dispersion compensation

We report on a novel technique to compensate for all-order polarization-mode dispersion. By means of this technique, based on a suitable combination of phase modulation and group-velocity dispersion, we compensated for as much as 60 ps of differential group delay that affected a 10-Gbit/s return-to-zero data stream.

Safety and cellular assessment of bronchial brushing in airway diseases

Bronchial brushing is a useful method for morphological and functional studies of bronchial epithelial cells (BECs) in various diseases. This technique has been found to be generally safe, but its safety in asthma and chronic bronchitis has not been fully assessed. The purpose of this study was to determine 1, whether bronchial brushing is a safe method in asthmatic and chronic bronchitis patients of differing severity and 2, to characterize the BECs obtained in terms of number, viability and purity. We evaluated 25 asthmatics of variable severity, 19 chronic bronchitis patients and 26 normal volunteers. Bronchoscopy and bronchial brushing were performed in a standardized manner by the same investigator. Safety was assessed by clinical follow-up of all subjects; continuous monitoring of arterial oxygen saturation during the procedure with a digital oximeter was carried out in a subsample of subjects. No complications were observed clinically during the procedure. There was a minimal fall in arterial oxygen saturation without a significant difference between the three groups of subjects. A consistent number of BECs was recovered and their viability, assessed by the trypan blue exclusion test, in asthmatics and chronic bronchitis patients was significantly lower than in controls (P < 0.05). Bronchial brushing is well tolerated and may be a valuable method of obtaining BECs in asthmatic and chronic bronchitis patients.

Eosinophilic inflammation assessed by induced sputum in corticosteroid-dependent asthma

Sputum induction can be used to study airway inflammation in asthmatics. However, it has not been used in patients with corticosteroid-dependent asthma requiring long-term oral corticosteroids. The aim of the study was to assess the number of eosinophils and the levels of eosinophil cationic protein (ECP) in sputum of 17 corticosteroid-dependent asthmatics by comparison with nine mild untreated asthmatics, 10 moderate asthmatics receiving inhaled steroids (ICS) and 11 healthy subjects. In the 17 corticosteroid-dependent asthmatics, we examined sputum eosinophil markers on two occasions and correlated with the control of asthma. Eosinophils were undetectable in controls and were detected in 63.8% of asthmatics. There were no significant differences between the three groups of asthmatics. ECP levels were significantly increased in ICS or corticosteroid-dependent asthmatics by comparison to controls and mild asthmatics. There was no significant difference between ICS and corticosteroid-dependent asthmatics. During follow-up, corticosteroid-dependent asthmatics with a controlled disease had no significant change in eosinophil numbers or ECP levels. On the other hand, corticosteroid-dependent asthmatics with recent exacerbations had a non-significant increase in eosinophil numbers and a significant increase in ECP levels. This study shows that ECP levels may be more accurate than eosinophil numbers in assessing exacerbations in corticosteroid-dependent asthmatics.

Long-range soliton interactions in dispersion-managed links

A numerical analysis of soliton propagation in a dispersion-compensated transmission system reveals the presence of a small dispersive-wave contribution to the propagating soliton that increases dramatically whenever the input soliton energy is detuned from its optimal value. A straightforward consequence of the dispersive-wave emission is an unexpectedly strong contribution to the long-range soliton-soliton interaction. We show that the combination of long- and short-range interactions induces soliton timing jitter that grows larger than that which arises from the Gordon-Haus effect.

Novel method for processing respiratory specimens for detection of mycobacteria by using C18-carboxypropylbetaine: blinded study

A novel method for processing respiratory specimens to improve culture and acid-fast staining of mycobacteria is introduced. This new method utilized N,N-dimethyl-N-(n-octadecyl)-N-(3-carboxypropyl)ammonium inner salt (Chemical Abstract Service no. 78195-27-4), also known as C18-carboxypropylbetaine (CB-18). In a blinded, five-center study, CB-18-based processing was compared to the standard method combining NALC and NaOH (NALC/NaOH). A total of 573 respiratory specimens were tested. Individual specimens were split approximately equally; the host institutions processed half of each specimen by the NALC/NaOH method, while the other half was processed with CB-18 at Quest Diagnostics--Baltimore. A total of 106 specimens were culture positive for acid-fast bacilli (AFB). Replacement of the primary decontamination agent with CB-18 caused changes in all diagnostic parameters. Aggregate culture sensitivity improved by approximately 43% (P < 0.01), and smear sensitivity improved by approximately 58% (P < 0.01). The sensitivity of smear relative to that of M. tuberculosis isolates exceeded 93% (P < 0.01) when specimens were processed with CB-18. The average times to a positive result were reduced by 7.3 days in liquid culture (P < 0.01) and 5.3 days on solid media (P < 0.05); however, the CB-18 method had a 20.8% contamination rate in liquid culture versus a rate of approximately 7.5% with NALC/NaOH processing. There were also unusual reductions in liquid culture sensitivity and smear specificity among CB-18-processed specimens. The characteristics of the latter parameters suggested that refinement of the CB-18 processing method should allow further improvements in culture sensitivity. This study showed that the CB-18 method has the potential to improve both smear and culture detection for these important human pathogens.

Safety of inducing sputum in patients with asthma of varying severity

Inducing sputum using hypertonic saline is a noninvasive method to investigate airway inflammation in people with asthma. However, hypertonic saline may also induce bronchoconstriction in some patients. The aim of the study was to examine whether the overall safety of using hypertonic saline to induce sputum in patients with mild to moderate asthma could be extended to patients with severe and/or uncontrolled asthma. Nine control subjects and 64 asthmatic patients with varying severity of the disease (FEV1 40-126% predicted values) were studied. Twenty-one of those patients had uncontrolled asthma. Sputum was induced in a standardized manner using hypertonic saline. The safety of the procedure was evaluated by assessing the clinical response and measuring FEV1 just before and during sputum induction. The procedure was well tolerated in most patients, but it had to be stopped due to side effects in 11.6% of patients with severe asthma. None of the side reactions were severe. Few patients with uncontrolled (17.3%) or severe asthma (18.6%) had a drop in FEV1 of 10-20%. The fall in FEV1 was significantly greater in patients with severe asthma than those with mild disease (p < 0.02 Mann-Whitney U test). We conclude that hypertonic saline-induced sputum is a safe technique even in patients with severe asthma.

Subcutaneous emphysema of the chest wall: a case with unusual presentation

Subcutaneous emphysema (SE) is the presence of air or other gas in the subcutaneous tissue and is generally associated with pneumothorax and/or pneumomediastinum. We describe an unusual presentation of SE of the chest wall without radiological evidence of pneumothorax or pneumomediastinum, which aetiopathogenesis remains open to several hypotheses in spite of an accurate clinical study.

Diffuse pulmonary calcinosis without calcium metabolism abnormalities in a renal transplant recipient

Eighteen years after an uneventful renal transplantation, the chest radiograph of an asymptomatic 50 year old man showed diffuse bilateral infiltrations, predominately at the right apex. Computed tomography (CT) scan demonstrated a diffuse alveolar pattern, the alveoli being filled with a very dense material, with some tracheal calcifications. Bronchoalveolar lavage fluid analysis was normal, but bronchial and transbronchial biopsies revealed calcium deposits in the bronchial mucosa and in the alveolar septa. The diagnosis of diffuse pulmonary calcinosis was established, despite normal blood calcium, phosphorus and magnesium levels, based upon computed tomography scan and pathological findings at fibreoptic bronchoscopy, without the need for an open lung biopsy.

Diffuse pulmonary calcinosis without calcium metabolism abnormalities in a renal transplant recipient

Eighteen years after an uneventful renal transplantation, the chest radiograph of an asymptomatic 50 year old man showed diffuse bilateral infiltrations, predominately at the right apex. Computed tomography (CT) scan demonstrated a diffuse alveolar pattern, the alveoli being filled with a very dense material, with some tracheal calcifications. Bronchoalveolar lavage fluid analysis was normal, but bronchial and transbronchial biopsies revealed calcium deposits in the bronchial mucosa and in the alveolar septa. The diagnosis of diffuse pulmonary calcinosis was established, despite normal blood calcium, phosphorus and magnesium levels, based upon computed tomography scan and pathological findings at fibreoptic bronchoscopy, without the need for an open lung biopsy.

Relaxation of guiding center solitons in optical fibers

We present a perturbative study of the mutual coupling between solitons and dispersive waves in periodically amplified links. Our analysis describes the limits of soliton transmissions operating beyond the average soliton regime.

Clock multiplication in a singly resonant fiber parametric oscillator

Soliton trains can be parametrically generated in fiber loops wherever an incoming soliton train interacts with a cw pump in the nonlinear loop. The phase-conjugated signal may either copy or multiply the incoming repetition rate, depending on whether the corresponding cavity harmonic is exactly matched or differs by an amount equal to an integer fraction of the longitudinal mode spacing. It is also shown that the phase relationship between adjacent solitons in the multiplicative conditions continuously evolves on propagation. This effect limits the range of potential application of multiplicative loops.

A 4-week, double-blind, parallel-group study to compare the gastrointestinal effects of meloxicam 7.5 mg, meloxicam 15 mg, piroxicam 20 mg and placebo by means of faecal blood loss, endoscopy and symptom evaluation in healthy volunteers

Meloxicam is a new non-steroidal anti-inflammatory drug (NSAID) which preferentially inhibits cyclooxygenase-2 (COX-2) over cyclooxygenase-1 (COX-1). Gastrointestinal (GI) tolerability of meloxicam 7.5 and 15 mg vs piroxicam 20 mg was evaluated in a 4-week, double-blind, parallel group, placebo-controlled study in 51 healthy male volunteers, using a combination of oesphago-gastro-duodenal endoscopy, faecal blood loss measurement and symptom evaluation. Analysis of covariance found no significant difference in faecal blood loss between the groups. However, significantly higher bleeding was found with piroxicam 20 mg compared with placebo using a Student's t-test on the weighted means. Endoscopy score were significantly higher with piroxicam than with meloxicam 7.5 mg or placebo (P < 0.01). A significant difference from baseline was observed in the meloxicam 15 mg and piroxicam groups (P < 0.05), but not in the meloxicam 7.5 mg and placebo groups. Six piroxicam-treated volunteers were withdrawn following a poor endoscopic score, but no such withdrawals occurred in the meloxicam and placebo groups (P < 0.01). Meloxicam 7.5 mg caused less GI damage compared with piroxicam 20 when administered to healthy young volunteers for 28 days; a possible dose dependency effect in GI tolerability was also suggested for meloxicam 7.5 and 15 mg, in relation to endoscopic findings.