POS0100 ACTIVATION OF THE CELLULAR INTEGRATED STRESS RESPONSE IN LABIAL SALIVARY GLANDS FROM SJÖGREN’S SYNDROME PATIENTS

Background

Sjögren’s syndrome (SS) is a chronic autoimmune disease characterized by inflammation of the exocrine glands and severe symptoms of eye and mouth dryness. Disorders in the saliva secretion process have been associated with oxidative and endoplasmic reticulum (ER) stress in combination with inflammatory responses. The integrated stress response (ISR) is a mechanism that allows cells to modify their gene expression program to restore homeostasis and promote their survival against various extrinsic and intrinsic stress signals, such as hypoxia, nutrient deprivation, viral infections, inflammatory factors (cytokines, chemokines, inflammasomes), and accumulation of unfolded proteins in the ER, among others (1). The ISR is regulated by four kinases: PERK, PKR, HRI and GCN2, that dimerize and autophosphorylate to become active and each one responds to different stress stimuli. The signaling pathways that are activated in response to stress factors stimulate the phosphorylation of eIF2α, which causes a transient inhibition of global protein synthesis and induction of synthesis of some specific genes like ATF4 and NRF2. ATF4 induces the transcription of genes involved in metabolism and nutrient uptake, redox status, and regulation of apoptosis. Dephosphorylation of eIF2α is the ISR termination signal to restore protein synthesis and is mediated by the PP1 complex, which recruits the catalytic subunit PP1c and one of its two regulatory subunits: GADD34 or CREP.

Objectives

To evaluate the presence and functional state (phosphorylation) of the ISR sensing kinases: PERK, PKR, HRI and GCN2; the levels of eIF2α /p-eIF2α and the key ISR transcription factors ATF4 and NRF2, as well as subunits of the complex involved in the ISR termination: PP1c, GADD34 and CREP in labial salivary glands (LSG) of SS-patients.

Methods

Biopsies of LSG from 12 SS-patients and 11 control subjects were studied. The levels of mRNA, protein and phospho (p)-protein of the ISR components were determined by RT-qPCR and Western blotting.

Results

Our results show increased levels of p-PERK/PERK ratio (11/11), PKR (7/11), p-PKR (7/11), p-PKR/PKR ratio (7/11), eIF2α (5/11), p-eIF2α (5/11) and ATF4 (11/11) in LSG from SS-patients compared to control subjects. No significant changes were found in mRNA levels of HRI, GCN2, and GADD34 between LSG from SS-patients and control subjects. Decreased protein levels of HRI (8/12), p-GCN2 (6/11), eIF2α (6/11), p-eIF2α (6/11), NRF2 (11/12), and p-NRF2 (12/12) were found in LSG showing scarce parenchyma and high fibrosis and fat infiltration. On the other hand, PP1c and CREP showed decreased mRNA and protein levels in all SS-patients LSG. Interestingly, Ro autoantibodies and focus score were negatively correlated with PP1c and NRF2 mRNA and protein levels whereas positively correlated with PKR mRNA levels.

Conclusion

The overexpression and activation of some ISR kinases together with the decrease in the PP1c/CREP phosphatase complex suggests a continuous activation of ISR, resulting in p-eIF2α to remain activated in LSG from SS-patients. This would explain the high protein levels of ATF4 and of target genes involved in the antioxidant response in LSG from SS patients suggesting that ISR activation plays a key role in pro-survival response to cellular stress.

References

[1]Pakos-Zebrucka K, Koryga I, Mnich K, Ljujic M, Samali A, Gorman AM. The integrated stress response. EMBO Rep. 2016;17(10):1374-95.

Acknowledgements

This work was supported by Fondecyt-Chile 1210055; Enlace-VID Universidad de Chile [ENL04/20 to MJG]; Fondecyt Iniciacion 11201058 and PhD fellowship Conicyt Chile.

Disclosure of Interests

None declared

POS0455 TOFACITINIB DECREASES INFLAMMATORY MARKERS AND MITOCHONDRIAL MORPHOLOGICAL DAMAGE IN SALIVARY GLANDS OF A MURINE MODEL OF SJÖGREN’S SYNDROME

Background

Altered homeostasis of salivary gland (SG) epithelial cells in Sjögren’s syndrome (SS) patients could be the initiating factor that leads to inflammation, as well as secretory dysfunction. Mitochondria are important organelles involved in cellular metabolism and their dysfunction can induce a loss of homeostasis and inflammation. Altered mitochondrion can release mitochondrial components that can act as damage-associated molecular patterns (DAMPs) and induce an inflammatory response via pattern recognition receptors (PRRs) such as the NLRP3 inflammasome, TLR9, cGAS/STING, and ZBP1 (1). Previously we determined that SG from SS patients showed and altered autophagy, which is associated to an increased pro-inflammatory cytokines expression. Interestingly, increased expression of pro-inflammatory markers such as IL-6, was reversed by JAK inhibitor tofacitinib in three-dimensional (3D)-acini deficient in autophagy (2). It is not clear whether the alterations in autophagy found in SG patients include alterations in mitochondrial clearance (mitophagy) that may lead to the accumulation of damaged mitochondria and enhanced inflammation. In this context, recent results of our laboratory showed, for the first time, severe ultrastructural alterations of mitochondria in SG cells from SS patients (1). However, it remains to be determined if these alterations are related to inflammation and if an anti-inflammatory agent could regulate these processes.

Objectives

To analyze the effect of tofacitinib on the mitochondrial ultrastructure in submandibular glands of a murine model of SS. In addition, to evaluate the effect of tofacitinib on the expression and activation of some PRRs involved in the recognition of mitochondrial DAMPs in the same murine model.

Methods

Six-month-old female NOD.B10Sn-H2b/J mice (Jackson Laboratories, USA) were used with 4-5 mice per group. Procedures were approved by the Universidad de Chile Animal Care and Use Committee. 30 mg/kg/day tofacitinib citrate was administered by oral gavage. After 28 days of tofacitinib or vehicle administration, their submandibular glands were obtained, which were processed to evaluate the mitochondrial ultrastructure by electron microscopy or lysed in RIPA buffer to obtain proteins. The protein levels of PRRs: NLRP3, TLR9, ZBP-1, and cGAs, as well as molecules activated downstream of cGAS and ZBP-1 such as TBK1, pTBK1, pSTING, and STING were determined by Western blotting.

Results

The results show that the mitochondria of the glandular epithelial cells of NOD.B10Sn-H2b/J mice treated with vehicle (control) present alterations such as swelling, disruption of membranes and crest disorganization that previously were reported in patients with SS (1). Interestingly, tofacitinib treatment improves the architecture of mitochondria. On the other hand, the protein levels of PRRs such as NLRP3 and cGAS decreased in mice treated with tofacitinib, as well as pTBK1.

Conclusion

The altered morphology of mitochondria together with the increased protein levels of PRRs and downstream markers of these PRRs suggests release of mitochondrial DAMPs in submandibular glands of NOD.B10Sn-H2b/J mice. The improvement in mitochondrial morphology as well as the decrease in PRRs activation under tofacitinib treatment suggest a potential use of this anti-inflammatory agent in mitochondrial alterations associated with inflammation. Many questions remain to be addressed, such as determining which mitochondrial DAMP might be being released and whether this is associated with impaired mitochondrial function in SS.

References

[1]Barrera, M. J., et al (2021). Dysfunctional mitochondria as critical players in the inflammation of autoimmune diseases: Potential role in Sjögren’s syndrome. Autoimmunity reviews, 20(8), 102867.

[2]Barrera, M. J., et al (2021). Tofacitinib counteracts IL-6 overexpression induced by deficient autophagy: implications in Sjögren’s syndrome. Rheumatology (Oxford, England), 60(4), 1951–1962.

Acknowledgements

This work was supported by Fondecyt Iniciación 11201058 and Fondecyt-Chile 1210055.

Disclosure of Interests

None declared.

A micro-CT analysis of radicular dentine thickness in mandibular first premolars presenting C-shaped root canals: Identification of potential danger zones

AIM

To describe the radicular dentine thickness in mandibular first premolars presenting C-shaped root canals, in order to identify the canal walls with less thickness as potential danger zones. In addition, to describe the internal and external anatomical characteristics of these teeth and to associate them to the dentine thickness.

METHODOLOGY

A total of 70 mandibular first premolars presenting C-shaped root canals were examined. Their internal morphology was analyzed using Vertucci´s and Fan´s criteria, and their external morphology was analyzed using the ASUDAS score. Besides, the dentine thickness around the root canals was two/three-dimensionally determined at five root planes and quantified in the distal and the mesial aspects.

RESULTS

According to Fan´s, ASUDAS, and Vertucci´s classifications, the most common canal configurations were category C3, grade 3, and type V, respectively. In Vertucci's type III anatomy, the mesial root wall of the lingual canal showed significantly less dentine thickness than the distal wall in the middle plane (p = 0.031). Similarly, in Vertucci's type V anatomy, significantly less dentine thickness was observed in the mesial root wall of the buccal and lingual canals in the middle plane (p < 0.001) and the buccal canal in the middle-apical plane (p = 0.014) than the distal root wall of these canals. In teeth with ASUDAS grade 3 and 4 scores, significantly less dentine thickness was observed in the mesial in comparison with the distal root wall of these canals. These differences were demonstrated in the middle and middle-apical planes (p < 0.001) of grade 3 teeth and the middle-apical plane (p < 0.001) of grade 4 teeth. In these root planes, the Ver1-AS3 and VerV-AS3 combinations presented a 4-times greater risk of presenting walls with a critical dentine thickness of 0.6 mm (OR=4, p = 0.025) than the combinations Ver1-AS2, VerV-AS2, VerV-AS4, and VerIII-AS3.

CONCLUSIONS

The root canal system configuration of mandibular first premolars with C-shaped canals showed a wide range of anatomical variations. The lowest dentine thickness was located in the mesial wall of the canals in the middle and apical root thirds of Vertucci´s type III and V anatomies and in teeth with deep radicular grooves scored as ASUDAS grade 3 and 4. In the middle and middle-apical planes, the presence of the combinations Ver1-AS3 and VerV-AS3 showed a high risk of presenting a critical dentine thickness of 0.6 mm. Therefore, these root canal walls with less dentine thickness represent potential instrumentation danger zones in mandibular first premolars with C-shaped canals.

POS0180 TYPE I INTERFERON DEPENDENT HSA-MIR-145-5P DOWNREGULATION MODULATES MUC1 AND TLR4 OVEREXPRESSION IN SALIVARY GLANDS FROM PRIMARY SJÖGREN’S SYNDROME PATIENTS

Background:

Primary Sjögren’s syndrome (pSS) is an autoimmune and inflammatory disease that mainly affects the salivary glands (SG) and is characterized by an overactivation of the type I interferon pathway (IFNs I). IFNs I are known to regulate the levels of microRNAs (miRNAs), non-coding RNAs whose levels are altered in pSS. IFNs I can decrease the levels of miR-145-5p, a miRNA with anti-inflammatory roles that has been reported downregulated in SG of from pSS patients [1]. This miRNA has TLR4 and MUC1 transcripts as predicted targets. MUC1 and TLR4 are two proteins overexpressed in SG of pSS patients that contribute, through various mechanisms, to the inflammatory state and glandular dysfunction [2-3]. Thus, we propose that IFNs I may contribute to a self-perpetuating inflammation loop through a hsa-miR-145-5p dependent MUC1 and TLR4 overexpression in the SG of pSS patients.

Objectives:

to evaluate whether mRNA levels of MUC1 and TLR4 are modulated by hsa-miR-145-5p in a IFNs I dependent manner.

Methods:

13 pSS patients and 9 controls SG biopsies were analyzed. hsa-miR-145-5p levels were determined by TaqMan assays and MUC1, TLR4, IFN-α and IFN-β mRNA levels by RT-qPCR. Additionally, in vitro assays using type I IFNs and chemically synthesized hsa-miR-145-5p mimics and inhibitors were performed to study its effect on MUC1 and TLR4 expression. JAK1 and STAT1 mRNA levels were also measured.

Results:

By Taqman assays we validated the decreased hsa-miR-145-5p levels (p=0.0001) in SG of pSS patients compared to controls. The decreased hsa-miR-145-5p levels correlated inversely with the increased mRNA levels of IFN-β (p=0.0192) in SG of pSS-patients. The hsa-miR-145-5p downregulation also correlated inversely with the overexpression of its predicted targets MUC1 (p=0.010) and TLR4 (p=0.0004). In vitro assays showed that IFN-β induces the overexpression of JAK1 (<p=0.0001) and STAT1 (p=<0.0001) leading to the downregulation of hsa-mir-145-5p (p=<0.0001) and increased MUC1 (p=<0.0001) and TLR4 mRNA levels (p=<0.0001). Functional assays suggest a regulation of hsa-miR-145-5p on MUC1 and TLR4 expression as MUC1 and TLR4 mRNA levels were decreased in HSG cells transfected with hsa-miR-513c-3p mimic and increased in HSG cells transfected with the miRNA inhibitor.

Conclusion:

Our findings suggest that IFNs I could induce the downregulation of hsa-miR-145-5p leading to the overexpression of MUC1 and TLR4 in SG from pSS patients. TLR4 is activated by ectopic mucins in the SG extracellular matrix from pSS patients which induces pro-inflammatory cytokines secretion [3]. Furthermore, the high levels of the MUC1-SEC and MUC1-Y isoforms observed in SG from pSS patients may favor cytokine synthesis through the immuno-enhancing peptide of MUC1-SEC or through the formation of a MUC1-SEC/MUC1-Y complex [4]. Therefore, IFNs I may contribute to the development of SS through amplification and perpetuation of inflammation due to a hsa-miR-145-5p dependent MUC1 and TLR4 overexpression.

References:

[1]I. Alevizos, et al,. Arthritis Rheum, 2011;63:535-44.

[2]HH. Sung, et al,. Oral Dis. 2015;21(6):730-8.

[3]MJ. Barrera, et al,. Rheumatology (Oxford). 2015;54(8):1518-27

[4]LM. Herbert, et al,. Cancer Res. 2004;64(21):8077-84.

Acknowledgements:

Fondecyt 1210055, Fondecyt 1160015, Fondecyt Iniciación 11170049, Fondecyt Iniciación 11201058, CONICYT fellowship (DJ, PC)

Disclosure of Interests:

None declared

THU0229 HSA-MIR-513C-3P OVEREXPRESSION DECREASES XBP-1S CORRELATING WITH INCREASED INFLAMMATION AND AUTOANTIBODIES IN SALIVARY GLANDS FROM SJÖGREN’S SYNDROME PATIENTS

Background:

Endoplasmic reticulum (ER) stress and the Unfolded Protein Response (UPR) are linked to inflammation in a variety of human pathologies including autoimmune diseases. Salivary glands (SG) from Sjögren’s syndrome (SS) patients have high levels of IFN-gamma among other cytokines, which trigger or exacerbate protein unfolding or misfolding, inducing ER stress. In this study, we focused on the IRE1α/XBP-1 pathway of the UPR, whose transcription factor is XBP-1s, which induces genes linked to regulation of the secretory pathway. We recently found that SG of SS patients have reduced levels of XBP-1s transcripts associated with an increased DNA methylation of XBP-1 promoter [1]. We postulate that other epigenetic mechanisms, such as miRNAs, could coexist with promoter DNA hyper-methylation to regulate XBP-1s expression.

Objectives:

Due to hsa-miR-513c-3p overexpression has been reported in SG from SS patients [2] and that XBP-1 is a predicted target of hsa-miR-513c-3p, the aim of this study was to evaluate whether mRNA levels of XBP-1s is modulated by hsa-miR-513c-3p and also if IFN-gamma modify the expression hsa-miR-513c-3p and XBP-1s.

Methods:

SG biopsies from 16 SS-patients with low and high focus score and 5 controls were analyzed. hsa-miR-513c-3p levels were measured by Taqman miRNA assays, whereas XBP-1s mRNA levels were determined by qRT-PCR. Additionally,in vitroassays using IFN-gamma and chemically synthesized hsa-miR-513c-3p mimics and inhibitors were performed to study its effect on XBP-1s expression.

Results:

By Taqman assays we validated the overexpression of hsa-miR-513c-3p in SG from 8 SS patients with low (p=0.03) and 8 SS-patients with high (p=0.003) focus score, compared with SG from 5 controls. In the same samples, a decrease of XBP-1s transcript levels was observed in SG from SS-patients with low (p=0.002) and high (p=0.026) focus score. XBP1s transcript levels were negatively correlated with hsa-miR-513c-3p (r=-0.47, p=0.014), Ro (r=-0.73, p=0.0009), ANA (r=-0.7, p=0.0033) and focus score (r=-0.72, p=0.001). Stimulation of 3D-acini with 1 ng/mL IFN-gamma increase the hsa-miR-513c-3p levels (p=0.014) and decrease the XBP-1s transcript levels (p=0.027). A negative correlation was found between hsa-miR-513c-3p and XBP-1s transcript levels in 3D-acini stimulated with IFN-gamma (r=-0.87, p=0.0001). The XBP-1s transcript levels were decreased in HSG cells transfected with hsa-miR-513c-3p mimic and increased in HSG cells transfected with the miRNA inhibitor.

Conclusion:

IFN-gamma-induced upregulation of hsa-miR-513c-3p is consistent with the presence of STAT1-binding elements in its promoter region. Our findings suggest that the combined action of miRNAs and DNA methylation modulated by IFN-gamma could explain the altered expression of XBP-1s, a key transcription factor involved in cellular proteostasis, affecting secretory function in LSG from SS-patients. Our results confirm previous correlations found between XBP-1s protein levels and clinical parameters of SS-patients, suggesting an association of XBP-1s with inflammation and impaired SG function.

References:

[1]D. Sepúlveda,et al, Rheumatology (Oxford), 2018;57:1021-32.

[2]I. Alevizos,et al,. Arthritis Rheum, 2011;63:535-44.

Acknowledgments :

Fondecyt 1160015, Fondecyt Iniciación 11170049, Fondecyt Postdoctorado 3170023, CONICYT fellowship (PC, DJ).

Disclosure of Interests: :

None declared

Th1/Th17/Th22 immune response and their association with joint pain, imagenological bone loss, RANKL expression and osteoclast activity in temporomandibular joint osteoarthritis: A preliminary report

It is well accepted that the presence of cytokines belonging to the Th1/Th17/Th22 axis of immuno-inflammatory response in the joint environment, such as IL-1β, IL-17 and IL-22, respectively, are associated with pathogenesis of several synovial joint degenerative disorders. During temporomandibular joint osteoarthritis (TMJ-OA), IL-1β and IL-17 have been implicated in the inflammation and resorption of sub-chondral bone; however, the role of Th22 response in the TMJ-OA pathophysiology has not been established. This study aimed to compare the expression of Th1/Th17/Th22-type cytokines, chemokines and chemokine receptors in synovial fluid samples obtained from TMJ-OA or disk displacement with reduction (DDWR) patients. In addition, it aimed to associate these levels with joint pain, imagenological signs of bone degeneration, RANKL production, osteoclastogenesis and osteoclast-induced bone resorption. Higher levels of IL-1β, IL-17 and IL-22 were expressed in TMJ-OA compared with DDWR subjects, and these increased levels significantly correlated with RANKL expression, joint pain and articular bone degeneration. Higher levels of CCR5, CCR6 and CCR7, as well as their respective ligands CCL5 and CCL20, responsible for recruitment of IL-1β, IL-17 and IL-22-producing cells, were over-expressed in TMJ-OA compared with DDWR subjects. Osteoclastogenesis and osteoclast-induced bone resorption were significantly greater in presence of synovial fluid from TMJ-OA compared with DDWR subjects. These data demonstrate that cytokines, CCLs and CCRs associated with the Th1/Th17/Th22 axis of immuno-inflammatory response are involved in TMJ-OA pathogenesis. These findings suggest that IL-22 is involved in the RANKL expression in TMJ-OA, which in turn induces differentiation of osteoclasts and subsequent resorption of sub-chondral bone.

Increased levels of the T-helper 22-associated cytokine (interleukin-22) and transcription factor (aryl hydrocarbon receptor) in patients with periodontitis are associated with osteoclast resorptive activity and severity of the disease

BACKGROUND AND OBJECTIVE

Two new T-helper (Th) phenotypes have been recently described and named Th9 and Th22 lymphocytes; however, their role in the pathogenesis of periodontitis remains unclear. This study was aimed to assess whether Th9 and Th22 lymphocytes, through interleukin (IL)-9 and IL-22 production, respectively, are associated with the severity of periodontitis and bone resorption.

MATERIAL AND METHODS

Gingival crevicular fluid samples and biopsies were obtained from patients with moderate-to-advanced chronic periodontitis and gingivitis, and healthy controls. The levels for the Th9 and Th22-associated cytokines and master-switch transcription factors Spi-B and aryl hydrocarbon receptor (AhR) were quantified by enzyme-linked immunosorbent assay, real-time reverse-transcription quantitative polymerase chain reaction and flow cytometry. In addition, the osteoclast activity in response to tissue homogenates from periodontitis and healthy samples was analyzed quantifying the number of TRAP-positive cells and areas of bone resorption pits produced, in the presence or absence of recombinant human IL-22 and anti-IL-22 neutralization antibody.

RESULTS

Higher levels of IL-22 and AhR were detected in patients with periodontitis compared with gingivitis and healthy individuals. In addition, higher levels of IL-9 and Spi-B were detected in gingivitis patients compared with periodontitis and healthy individuals. In patients with periodontitis, a significant positive correlation was detected between secreted levels of IL-22 and clinical attachment level of the sampled periodontal pockets. When osteoclasts were exposed to tissue homogenates obtained from patients with periodontitis, higher levels of resorptive activity were observed as compared with the same cells exposed to tissue homogenates obtained from healthy individuals, and this increment was dependent on the presence and neutralization of IL-22.

CONCLUSION

Increased levels of IL-22 produced by Th22 lymphocytes are associated with the pathogenesis of periodontitis, in particular, with osteoclast resorptive activity and severity of disease.

Removal of sulfur-containing organic molecules adsorbed on inorganic supports by Rhodococcus Rhodochrous spp

OBJECTIVE

To remove dibenzothiophene (DBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) adsorbed on alumina, silica and sepiolite through biodesulfurization (BDS) using Rhodococcus Rhodochrous spp., that selectively reduce sulfur molecules without generating of gaseous pollutants.

RESULTS

The adsorption of DBT and 4,6-DMDBT was affected by the properties of the supports, including particle size and the presence of surface acidic groups. The highest adsorption of both sulfur-containing organic molecules used particle sizes of 0.43-0.063 mm. The highest percentage removal was with sepiolite (80 % for DBT and 56 % for 4,6-DMDBT) and silica (71 % for DBT and 37 % for 4,6-DMDBT). This is attributed to the close interaction between these supports and the bacteria.

CONCLUSIONS

Biodesulfurization is effective for removing the sulfur-containing organic molecules adsorbed on inorganic materials and avoids the generation of gaseous pollutants.

Serotype b of Aggregatibacter actinomycetemcomitans increases osteoclast and memory T-lymphocyte activation

During periodontitis, alveolar bone resorption is associated with activation of T helper type 17 (Th17) lymphocytes and receptor activator of nuclear factor-κB ligand (RANKL) -induced osteoclasts. We previously reported that serotype b of Aggregatibacter actinomycetemcomitans has a higher capacity to trigger Th17-type differentiation and function in activated T lymphocytes and its lipopolysaccharide is a more potent immunogen compared with the other serotypes. This study aimed to investigate whether serotype b of A. actinomycetemcomitans induces higher Th17-associated RANKL production, RANKL-induced osteoclast activation, and antigen-specific memory T lymphocyte proliferation. On naive CD4(+) T lymphocytes stimulated with autologous dendritic cells primed with different A. actinomycetemcomitans serotypes, RANKL production, T-bet, GATA-3, RORC2 and Foxp3 expression, RORC2/RANKL intracellular double-expression, TRAP(+) osteoclast activation, and bone resorption were quantified. The frequency of proliferating memory T lymphocytes in response to A. actinomycetemcomitans serotypes was determined in periodontitis and healthy subjects. Naive CD4(+) T lymphocytes stimulated by serotype b-primed dendritic cells elicited higher levels of RANKL, RORC2, TRAP(+) osteoclasts, and bone resorption than the same cells stimulated with the other serotypes. RANKL positively correlated and co-expressed with RORC2. Memory T lymphocytes responding to serotype b were more frequently detected in periodontitis patients than healthy subjects. These results indicate that serotype b of A. actinomycetemcomitans is associated with higher production of RANKL and these increased levels are associated with Th17 lymphocyte induction, osteoclast activation, and bone resorption.

Hyoid and laryngeal excursion kinematics - magnitude, duration and velocity - changes following successful exercise-based dysphagia rehabilitation: MDTP

Variability in magnitude of deglutitional hyolaryngeal excursion in patients with dysphagia suggests that it does not adequately represent the kinematics of swallowing difficulties or recovery following rehabilitation. On the other hand, reduced hyolaryngeal excursion velocity has been reported in patients with dysphagia. While increased movement velocity often accompanies clinical and functional recovery in many diseases, velocity changes in swallowing-related movement following dysphagia therapy have not been well studied. This study evaluated changes in hyoid and laryngeal excursion (magnitude, duration and velocity) before and following successful dysphagia therapy to provide a more comprehensive representation of improvement to swallowing kinematics in patients who have experienced successful rehabilitation. A secondary analysis of case series data was completed. Eight patients with severe, chronic dysphagia completed a standard course of an exercise-based dysphagia treatment programme (McNeill dysphagia therapy program, MDTP). Pre- and post-treatment, kinematic aspects of swallowing were evaluated for thin liquid, thick liquid and pudding swallows. Maximum hyoid and laryngeal excursion magnitude and excursion duration were measured. Excursion velocities were calculated from excursion magnitude and duration measures. Successful treatment for dysphagia facilitated increased hyolaryngeal excursion magnitude, duration and velocity. These changes were most prominent for the hyoid and most often observed with thin liquids. By examining hyoid and laryngeal excursion velocity in patients who have experienced successful dysphagia rehabilitation, this study demonstrated the value of evaluating spatial and temporal aspects of swallowing kinematics in a single measure for a more comprehensive representation of positive changes underlying functional recovery.

Randomized phase II study of cisplatin plus gemcitabine administered either as short infusion or at a fixed dose rate in non-small cell lung cancer (NSCLC)

17037

Background: Previous studies have indicated that, in combination with cisplatin (cis), fixed dose rate gemcitabine (gem) may be more efficacious than standard infusion gem. This open-label, randomized, multicenter Phase II study (B9E-LA-S350) was aimed to compare the efficacy and safety of these regimens as treatment for advanced NSCLC in Latin American patients (pts). Methods: Major eligibility criteria included histologic/cytologic diagnosis of stage IIIB/IV NSCLC not amenable to curative surgery; and at least one measurable lesion. Pts were randomized to receive up to 6 cycles of treatment with cis 75 mg/m2 on Day 1 plus either gem 1000 mg/m2 over 30 min on Days 1 and 8 of a 21-day cycle (standard arm) or gem 1000 mg/m2 at a fixed dose rate of 10 mg/ m2/min on Days 1 and 8 of a 21-day cycle (FDR arm). The primary endpoint was the objective response rate (ORR; assessed by RECIST criteria) and secondary endpoints included overall survival (OS), progression-free survival (PFS), duration of tumor response (TR), and toxicity. Results: The results from this interim analysis assessed all objectives. Sixty-four pts were randomized to treatment (N = 33 standard arm; N = 31 FDR arm): 22 females; mean age 60 ± 9 yrs; 20% stage IIIB, 80% stage IV. In the standard arm, 9 (27%) pts responded (CR or PR) compared to 6 (20%) pts in the FDR arm (Odds ratio: 0.67, 95% CI 0.21–2.2, p = .56). As shown in the table below, there were no statistically significant differences in median ORR, OS, PFS, TR times, and Grade (G) 3/4 toxicities. Conclusions: The standard and FDR gem and cis treatment regimens produced similar results for both efficacy and toxicity in this patient population. This trial does not support the use of a FDR administration of gem in Latin American pts with NSCLC.

[Table: see text]

[Table: see text]

[Evolution study in children with suspected obstructive sleep apnea]

INTRODUCTION

Obstructive sleep apnea syndrome is a common disorder in childhood with an uncertain evolution.

OBJECTIVES

Study of children's clinical evolution with suspected diagnosis of OSAS, which was carried out after two years of an overnight polisomnogram.

PATIENTS AND METHODS

73 children were studied. We evaluated if they had been operated and what type of surgery was performed, Brouillete Scale and subjective impressions. We have correlated: age, clinical evolution and surgery.

RESULTS

Age was inversely correlated with changes in Brouillete (r=-0.39, p=0.002), standing out that children that underwent surgery were younger (4.1 vs. 7.0 years, Student t: -4.22, p=0.00009). Without the influence of age, the difference between evolution in operated and not operated ones was not significative, statistically speaking, but it was if we analysed the different types of surgery by themselves (Snedecor F: 3.9, p=0.007), tonsillectomy was the larger.

CONCLUSION

The middle-term evolution in children with OSAS is good if we use the correct treatment.

[Landau kleffner syndrome]

INTRODUCTION

The Landau Kleffner syndrome (SLK) is associated with paroxystic alterations of the electroencephalogram which are intensified during sleep, with acquired aphasia and epilepsy, in 75 83% of the cases. The syndrome is associated with other features, such as personality disorders presenting as autistic behaviour, cognitive regression and in some cases, motor dysfunction. The epileptic activity appears to be responsible for the disorder. Treatment with anti epileptic drugs is ineffective in many cases, although there may be periods of spontaneous improvement, or there may be permanent sequelas of language. Design. A systematic revision of one case.

CASE REPORT

A five year old boy with no previous clinical history had, at the age of four years, presented with behaviour changes and aphasia, accompanied by paroxystic changes on the EEG and nocturnal polysomnogram. On cranial CT there was a mid line cyst. He had had no seizures. Treatment. Treatment with carbamazepine led to clinical improvement in behaviour, reduction in the paroxysms and appearance of sleep spindles, but little effect on the degree of aphasia.

CONCLUSIONS

The case described is a variant of SLK, with no epileptic seizures, some improvement on carbamazepine and a mid line cyst.

[Post traumatic partial seizures]

INTRODUCTION

Post traumatic epilepsy represents 4% of the prevalence of the disorder and is one of the sequelas which is most difficult to prevent. Risk factors have been described to predict the appearance of seizures.

CLINICAL CASE

A seven year old boy with a severe head injury was admitted to the Intensive Care Unit. On neuroimaging studies there were multiple foci of contusion, mainly in the left hemisphere, and blood in the III and IV ventricles and frontal horn of the left lateral ventricle. The patient had severe sequelae of head injury with a right spastic hemiplegia and hemiparesia with hypertony of the left side, together with complete blindness of both eyes due to bilateral atrophy of the optic nerve. Serial EEG were done, in which a recording showed alternating periods of hypervoltage grapho elements superimposed on a trace of very low voltage, with continuous activity of low voltage and low frequency. There were no grapho elements with acute morphology. However, the patient had a first partial seizure a year and a half after his head injury. On the EEG an epileptogenic focus was identified in the left hemisphere. Within two years of his head injury he had seven seizures. He had not received prophylactic antiepileptic treatment after the head injury.

CONCLUSIONS

We report a case of epilepsy secondary to a head injury, in which the first seizure occurred one and a half years after injury. In view of the risk factors, we discuss whether prophylactic anti epileptic treatment might have been beneficial.

Frequency of CCR5 gene 32-basepair deletion in Chilean HIV-1 infected and non-infected individuals

A 32-basepair deletion polymorphism in the CCR5 chemokine receptor gene (CCR5Delta32) has been identified and shown to have functional significance in determining susceptibility to infection by human immunodeficiency virus type 1 (HIV-1) and possibly in influencing disease progression in HIV-1 positive individuals. These findings led to an interest in studies of DeltaCCR5 allele geographical distribution in human population, for complete understanding of the role of CCR5 in HIV-1 epidemiology. Inter-population variation in CCR5Delta32 frequency may be a significant factor in the prediction of AIDS endemicity. In this report we assessed the frequency of DeltaCCR5 in a Chilean population (63 HIV-1 infected and 62 non-infected individuals). No homozygous CCR5Delta32 individual was identified, and no significant difference was observed between HIV-1 infected (3/63) and non-infected (3/62) individuals for the heterozygote CCR5Delta32 state. This is the first evidence of the contribution of DeltaCCR5 allele to the genetic background of the Chilean population, which is characterized by intense ethnic admixture and by gene flow from the European Spanish gene pool.

Rheological and physicochemical properties of starches from moist- and dry-type sweetpotatoes

Although starch makes up from 50 to 70% of sweetpotato (SP) dry matter, its role in cooked texture is unknown. The purpose of this research was to characterize raw starches isolated from SP cultivars and experimental selections (C/S) with a wide range of textural properties when cooked and to investigate the relationship between textural properties of the cooked roots and characteristics of the isolated starches. Shear stress measured by uniaxial compression of cooked SP cylinders served as an objective measure of SP texture. Starches were isolated from C/S representing three SP texture types: moist (Jewel and Beauregard); intermediate (NC10-28 and NC2-26); and dry (NC6-30 and NC8-22). The following parameters of isolated starches were measured: amylose content by colorimetric and differential scanning calorimetric (DSC) methods; swelling power, solubility, gelatinization enthalpy (DeltaH), and pasting properties by Brabender amylograph (BA) and rapid viscoanalyzer (RVA). Pasting temperatures for SP C/S measured by BA and RVA were significantly correlated. Due to high shear degradation in RVA, RVA viscosities of starch suspensions decreased as much as 40% during cooking at 95 degrees C, whereas the BA viscosities changed little at this temperature. There were no statistically significant differences among the C/S for amylose or DeltaH. However, significant C/S differences in swelling power, solubility, and pasting properties were observed. Although differences in some rheological and physical properties were observed for C/S starches, shear stress was statistically correlated only with DSC onset temperature (r = 0.78), indicating that factors other than the properties measured on isolated starches are mainly responsible for the texture of cooked SP C/S.

[Dental fluorosis: quantification of Streptococcus mutans in school children from Mamiña, Chile. A longitudinal study]

BACKGROUND

High fluorine concentrations in drinking water are associated with a decrease in the amount of salivary S mutants. Taking into account that clinical dental fluorosis can appear with 1.5 ppm of fluorine in the drinking water, fluorine concentrations in Mamiña is 2.4 ppm.

AIM

To quantify salivary S mutans in school age children from Mamiña, a zone with a high fluorine content in the drinking water, during one year.

MATERIAL AND METHODS

During 1997 and 1998, dental health was assessed and salivary samples were obtained from 51 children (27 male) aged 10 +/- 2 years to quantify S mutans.

RESULTS

Most children studied had more than 10(5) salivary S mutans colony forming units. No changes in the rates of infection or dental health characteristics were observed during the observation year.

CONCLUSIONS

High fluorine content in the drinking water did not have an effect on salivary S mutans infection in this population.

[Clinical usefulness of rheumatoid factor in synovial fluid. Re-evaluation]

The aim of this work is to analyze the usefulness of rheumatoid factor determination in synovial fluid. One hundred twenty nine patients (29 with rheumatoid arthritis), in whom rheumatoid factor was simultaneously determined in serum and synovial fluid, were retrospectively analyzed. Serum rheumatoid factor had a 48% sensitivity, 98% specificity, 88% positive predictive value and 87% negative predictive value for the diagnosis of rheumatoid arthritis. These numbers were 76, 79, 51 and 92% respectively for synovial fluid rheumatoid factor. In rheumatoid arthritis of less than one year of evolution, serum and synovial rheumatoid factor have a sensitivity of 15% and 62% respectively, a positive predictive value of 50 and 28% respectively and a negative predictive value of 90 and 94% respectively. It is thus concluded that the absence of rheumatoid factor in serum and synovial fluid in a patient with arthritis of less than one year of evolution, renders the diagnosis of rheumatoid arthritis very unlikely. Likewise the simultaneous presence of rheumatoid factor in both fluids has a high diagnostic certainty. Among other studied variables, leukocyte count, C3 and C4 levels in synovial fluid are the best discriminators within the different diagnostic groups.

Erythrocyte and HLA antigens of Atacameño Indians

The present study reports the results of erythrocyte antigen typing for the following systems: ABO, MN, Rh, Kell, Duffy, and Diego in roughly 180 Atacameño Indians from the oasis of Toconao, northern Chile. A subsample was tested for variation at the histocompatibility loci A, B, and C. Results agree with previous findings based on smaller samples. Caucasian admixture of the Atacameño from Toconao was estimated to be 0.056 +/- 0.022.