Action mechanisms of probiotics on Candida spp. and candidiasis prevention: an update.

Due to the high incidence of fungal infections caused by Candida species and their increasing resistance to antimicrobial treatments, alternative therapies such as probiotics have been studied. It has been show that several species of the genus Lactobacillus have anti-Candida activity, probably by direct inhibition, through competition for adhesion sites or production of secondary metabolites, and by indirect inhibition, through stimulation of the immune system of their host. However, the mechanisms of inhibition of these probiotics on Candida species have not yet been fully elucidated since this effect is related to more than one inhibition pathway. In the literature, several in vitro and in vivo studies have been developed seeking to elucidate the probiotics mechanisms of action. These studies have been focused on C. albicans inhibition assays, including analysis of antimicrobial activity, adherence capacity, biofilms formation, filamentation and interference on virulence genes, as well as assays of experimental candidiasis in invertebrate and vertebrate models. In this context, the purpose of this review was to gather different studies focused on the action mechanism of probiotic strains on Candida sp. and to discuss their impact on the candidiasis prevention.

Distal radius and tibia bone microarchitecture impairment in female patients with diffuse systemic sclerosis.

Radius and tibia bone microarchitecture, analyzed through a high-resolution peripheral quantitative computed tomography, were significantly impaired in female patients with diffuse systemic sclerosis compared with healthy controls. Acroosteolysis, quality of life-grip strength, hand disability, and disease duration were significantly associated with this bone deterioration. INTRODUCTION: The effect of diffuse systemic sclerosis (dSSc) on the bone is not completely understood. The objective of this study was to analyze the volumetric bone mineral density (vBMD), microarchitecture, and biomechanical parameters at the distal radius and tibia using high-resolution peripheral quantitative computed tomography (HR-pQCT, XtremeCT) in female patients with dSSc and identify clinical and laboratory variables associated with these parameters. METHODS: Thirty-eight women with dSSc and 76 healthy controls were submitted to HR-pQCT at the distal radius and tibia. Clinical and laboratory findings, bone mineral density(BMD), nailfold capillaroscopy (NC), total passive range of motion(ROM), and quality of life (health assessment questionnaire-HAQ) were associated with HR-pQCT (Scanco Medical AG, Brüttisellen, Switzerland) parameters. Multiple linear regression models adjusted for clinical and laboratory variables, ROM and HAQ, were performed. RESULTS: Density, microarchitecture, and biomechanical parameters at the distal radius and tibia were significantly impaired in dSSc patients compared with healthy controls (p < 0.001). Multiple linear regression models showed that lower trabecular density (Tb.vBMD) (radius R2 = 0.561, p = 0.002; and tibia R2 = 0.533, p = 0.005), and lower trabecular number (Tb.N) (tibia R2 = 0.533, p = 0.005) were significantly associated with acroosteolysis. Higher trabecular separation (Tb.Sp) was associated with disease duration and higher HAQ-grip strength (radius R2 = 0.489, p = 0.013), while cortical density (Ct.vBMD) was associated with ROM (radius R2 = 0.294, p = 0.002). CONCLUSION: Bone microarchitecture in patients with dSSc, analyzed through HR-pQCT, showed impairment of trabecular and cortical bone at distal radius and tibia. Variables associated with hand involvement (acroosteolysis, quality of life-grip strength, and ROM) and disease duration may be considered prognostic factors of this bone impairment.

Effect of ethylenediaminetetraacetic acid irrigation on immune-inflammatory response in teeth submitted to regenerative endodontic therapy.

AIM: To analyse longitudinally the immune-inflammatory response in teeth of mice that underwent a regenerative protocol with or without the use of ethylenediaminetetraacetic acid (EDTA) to irrigate the root canal system. METHODOLOGY: First maxillary molars of mice were devitalized using size 10 and 15 files. Teeth were divided into the following groups: Empty - the canals were left empty; Blood Clot (BC) - the canals were filled with a blood clot; and EDTA + Blood - the canals were irrigated with 0.06 mL of 17% EDTA for 1 min and filled with a blood clot. Access cavities were restored with Coltosol® . Animals were sacrificed at 7, 14 or 21 days after the operative procedures, and teeth were collected. RNA was extracted, mRNA expression of the cytokines IGF, NGF, IL-1α, IL-10, TGF and VEGF was assessed using real-time PCR, and the anova Kruskal-Wallis test was used. RESULTS: IL-1 mRNA expression was significantly higher in the EDTA + BC group than in the Empty and BC groups at the 7th and 14th days of evaluation (P < 0.05). IL-10 mRNA expression was similar across the three groups at all time periods. TGF-ß mRNA expression in the EDTA + BC group was significantly higher on the 7th and 21st days than on the 14th (P < 0.05); at day 21, TGF-ß mRNA expression was similar between the BC and EDTA + BC groups but significantly higher than in the Empty group (P < 0.05). IGF mRNA expression was significantly higher in the EDTA + BC group than in the other groups at all time periods. VEGF mRNA expression remained unchanged throughout the experimental period in all groups (P > 0.05). NGF mRNA expression was similar amongst all groups at the 7th and 21st days (P > 0.05). At the 14th day, however, there was a significant increase in NGF mRNA expression in the EDTA + Blood group (P < 0.05) when compared with the expression in the other groups. CONCLUSION: EDTA promoted increased expression of factors that have the potential to improve the outcome of regenerative endodontic treatment.

SiGe nano-heteroepitaxy on Si and SiGe nano-pillars.

In this paper, SiGe nano-heteroepitaxy on Si and SiGe nano-pillars was investigated in a 300 mm industrial reduced pressure-chemical vapour deposition tool. An integration scheme based on diblock copolymer patterning was used to fabricate nanometre-sized templates for the epitaxy of Si and SiGe nano-pillars. Results showed highly selective and uniform processes for the epitaxial growth of Si and SiGe nano-pillars. 200 nm thick SiGe layers were grown on Si and SiGe nano-pillars and characterised by atomic force microscopy, x-ray diffraction and transmission electron microscopy. Smooth SiGe surfaces and full strain relaxation were obtained in the 650 °C-700 °C range for 2D SiGe layers grown either on Si or SiGe nano-pillars.

Lactobacillus rhamnosus inhibits Candida albicans virulence factors in vitro and modulates immune system in Galleria mellonella.

AIM: The aim of this study was to evaluate the potential anti-Candida effects of Lactobacillus rhamnosus ATCC 9595 on Candida albicans ATCC 18804 using in vitro and in vivo models. METHODS AND RESULTS: The in vitro analysis evaluated the effects of L. rhamnosus on C. albicans's biofilm formation by CFU count and metabolic activity, filamentation capacity, and adhesion (ALS3 and HWP1) and transcriptional regulatory gene (BCR1 and CPH1) expression. The in vitro results showed that both the L. rhamnosus cells and supernatant reduced C. albicans biofilm formation, filamentation and gene expression. In the in vivo study, the treatment with L. rhamnosus supernatant increased 80% the survival of Galleria mellonella larvae infected with C. albicans. Furthermore, the supernatant of L. rhamnosus recruited haemocytes into the haemolymph (2·1-fold increase). CONCLUSIONS: Lactobacillus rhamnosus reduced the biofilm formation and filamentation of C. albicans in vitro by negatively regulating all studied C. albicans genes. Lactobacillus rhamnosus protected G. mellonella against experimental candidiasis in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first study to report the anti-Candida properties of L. rhamnosus ATCC 9595. The supernatant of this strain has immunomodulatory effects on the G. mellonella model and protects the larvae against pathogens.

Prediction of disease severity in neuromyelitis optica by the levels of interleukin (IL)-6 produced during remission phase.

T helper type 17 (Th17) cytokines have been implicated in the pathogenesis of neuromyelitis optica (NMO). As humanized anti-interleukin (IL)-6R (tocilizumab) immunoglobulin (Ig)G has been used as disease-modifying therapy for NMO, the objective of our study was to investigate the role of endogenous IL-6 on NMO-derived CD4(+) T cell behaviour. High production of IL-6, IL-17 and IL-21 by CD4(+) T-cells was detected in NMO patients. Further, IL-21 and IL-6 levels were related directly to the level of neurological disabilities. The addition of anti-IL-6R IgG not only reduced directly the production of these cytokines, but also almost abolished the ability of activated autologous monocytes in enhancing IL-6, IL-17 and IL-21 release by CD4(+) T cells. In contrast, the production of IL-10 was amplified in those cell cultures. Further, anti-IL-6R monoclonal antibodies (mAb) also potentiated the ability of glucocorticoid in reducing Th17 cytokines. Finally, the in-vivo and in-vitro IL-6 levels were significantly higher among those patients who experienced clinical relapse during 2-year follow-up. In summary, our results suggest a deleterious role of IL-6 in NMO by favouring, at least in part, the expansion of corticoid-resistant Th17 cells.

Late postoperative myelomalacic myelopathy.

STUDY DESIGN: This is a case report. OBJECTIVES: Spinal cord atrophy presenting with late progressive myelopathy after many years of clinical stability is a rare and unexplained phenomenon after cervical spine surgery. The authors report and discuss the etiologies and outcomes of late postoperative myelomalacic myelopathy. SETTING: This study was conducted in the Department of Neurosurgery, Centro Hospitalar S. João, Porto, Portugal. METHODS: We report on two patients with insidious chronic progressive myelopathy that developed more than 10 years after complete removal of a cervical intramedullary ependymoma and after transoral odontoidectomy and occipitocervical fusion for craniocervical junction malformation. Differential diagnoses were formulated and review of the literature was performed. RESULTS: In both patients, after several years of clinical stability, insidious onset of debilitating myelopathy and dependency ensued. The clinical history, serology, imaging and neurophysiological investigation excluded several putative etiologies: arachnoid adhesions, tumor recurrence, late vertebral instability, trauma, syringomyelia, radiotherapy, and demyelinating or infectious causes. CONCLUSION: Late neurological deterioration after cervical spine surgery is usually related to disease progression or surgery-related complications. Nevertheless, in some patients late myelopathy can ensue even in the absence of identified causes.

Hypomagnesaemia and hypocalcaemia in a patient with systemic sclerosis: role of proton pump inhibitors.

Proton pump inhibitors (PPI) are widely used in patients with systemic sclerosis (SSc) due to the chronic gastroesophageal reflux. The authors report a female patient with a 9-year history of SSc and long-term use of omeprazole, who complained of paresthesia and asthenia for 12 months. Physical examination revealed clinical signs of hypocalcaemia confirmed by laboratory tests that also showed hypomagnesaemia. After exclusion of possible causes, hypomagnesaemia secondary to PPI was diagnosed and omeprazole was replaced by a histamine H2-receptor antagonist: ranitidine. Despite continuous magnesium supplementation, the reintroduction of PPI at a lower dose due to worsening of dyspeptic symptoms led to recurrence of hypomagnesaemia. After definitive suspension of PPI, reintroduction of ranitidine and optimisation of anti-reflux environmental measures, the patient stabilised. In conclusion, SSc patients using PPIs should have their magnesium and calcium serum levels measured periodically, and non-specific symptoms such as asthenia, generalised paresthesia or life-threatening manifestations (seizures, arrhythmias) should not be neglected.

Hypertension and diabetes significantly enhance the risk of cardiovascular disease in patients with psoriatic arthritis.

OBJECTIVES: New evidence has lightened the linkage between psoriatic arthritis (PsA) and the development of atherosclerosis and cardiovascular disease (CVD). We aimed to describe the prevalence of cardiovascular events and associated risk factors among patients with PsA. METHODS: Retrospective evaluation of medical records from consecutive PsA patients who fulfilled the CASPAR criteria for PsA attending a specialised spondyloarthritis clinic at a single referral centre. CVD was defined based on the occurrence of coronary artery disease (CAD) or cerebrovascular ischaemic disease events. RESULTS: We evaluated 158 PsA patients, 48.7% females and 51.3% males, aged 53.7±13.9 yrs. Mean PsA duration was 13.7±8.9 yrs and polyarticular subtype affected 66 (42%) patients. According to drug therapy, 85 (54%) were using NSAIDs and 21 (13%) low-dose prednisone; 32 (20%) were on anti-TNF agents, 94 (60%) metothrexate, 18 (11%) leflunomide, 13 (8%) sulfasalazine, 5 (3%) other immunossupressors and 4 (2.5%) were on chloroquine. Over half patients (87, 55%) had arterial hypertension (AH); 51 (32%) had dyslipidaemia (DLP), 38 (29%) hypertriglyceridemia and 36 (23%) diabetes mellitus (DM). Lipid profile was similar for both genders with mean total cholesterol= 186.5±38.6mg/dl, LDL=112.3±30.6 mg/dl, HDL= 47.89±14.6 and triglycerides= 127.4± 65.6 mg/dl. Of note, 14% PsA patients have had CVD, namely cerebrovascular or coronary heart disease. Sex, age, disease duration, joint involvement subtype, disease activity, CRP and lipid levels were similar among patients with and without CVD. The prevalence of AH (95% vs. 45%, p<0.001), DLP (75% vs. 27.7%, p<0.001) and DM (60% vs. 19%, p<0.001) were significantly greater in PsA patients who have had CVD compared to those without CVD, conferring an odds ratio of 21.0 for AH and of 5.4 for DM. CONCLUSIONS: The high prevalence of CVD in PsA patients is influenced by increased AH and DM. Hence early recognition and specific treatment is mandatory in order to reduce the risk for CVD, avoiding early morbidity and mortality.

Glycemic variability after mechanical thrombectomy for anterior circulation acute ischemic stroke. / Variabilidad glucémica tras trombectomía mecánica en el ictus isquémico agudo de la circulación anterior.

INTRODUCTION: Morbidity remains high among patients who undergo successful mechanical thrombectomy (MT) for anterior circulation large vessel occlusion (LVO). Stress hyperglycemia worsens the prognosis after acute ischemic stroke (AIS), but aggressively treating hyperglycemia does not improve the outcome. There is no consensus on how to best manage glycemia after AIS. Glycemic variability (GV) reflects glycemic fluctuations over time and could be the culprit. We aimed to elucidate how GV impacts outcome of AIS patients treated with MT. PATIENTS AND METHODS: This was a single-center retrospective study. We consecutively included AIS patients who received MT for anterior circulation LVO. We recorded discrete blood glucose measurements within the first 24 hours post thrombectomy, from which we calculated two measures of GV: standard deviation (SD) and coefficient of variation. Univariate and multivariate analyses were conducted to identify predictors of poor functional outcome (modified Ranking scale score 3-6) and mortality at 3-month follow-up. RESULTS: We included 657 patients. Patients with poor functional outcome (42.5%) and patients that died (14.8%) had significantly higher GV as measured by SD. In a multivariable model adjusted for confounders, higher SD was associated with mortality -adjusted odds ratio: 1.020 (95% CI 1.001-1.040)- but not with functional outcome -adjusted odds ratio for modified Ranking scale score 3-6: 1.007 (95% CI 0.990-1.025)-. CONCLUSIONS: Our results suggest that higher GV after MT for anterior circulation AIS is an independent risk factor for 3-month mortality. Future trials should evaluate the benefit of reducing GV in this setting.

TITLE: Variabilidad glucémica tras trombectomía mecánica en el ictus isquémico agudo de la circulación anterior.Introducción. La morbilidad de los pacientes con ictus isquémico agudo (IIA) sometidos a trombectomía mecánica (TM) exitosa permanece alta. La hiperglucemia empeora el pronóstico tras un IIA, pero tratarla agresivamente no mejora los resultados. No existe consenso sobre el tratamiento óptimo de la glucemia después de un IIA. La variabilidad glucémica (VG), que refleja las fluctuaciones glucémicas a lo largo del tiempo, puede ser un factor importante. Nuestro objetivo fue investigar cómo la VG afecta el resultado de pacientes con IIA tratados con TM. Pacientes y métodos. Realizamos un estudio retrospectivo unicéntrico que incluyó a pacientes con IIA que recibieron TM para la oclusión de un gran vaso de la circulación anterior. Se registraron mediciones discretas de glucemia en las primeras 24 horas postrombectomía, a partir de las cuales se calcularon dos medidas de VG: desviación estándar y coeficiente de variación. Se realizó un análisis univariado y multivariado para identificar predictores de resultado funcional desfavorable (escala de Rankin modificada: 3-6) y mortalidad a los tres meses. Resultados. Se incluyó a 657 pacientes. Los que tenían una puntuación en la escala de Rankin modificada = 3 (42,5%) y los fallecidos (14,8%) tuvieron una VG significativamente mayor medida por desviación estándar. En un modelo multivariado, una mayor desviación estándar se asoció de forma independiente con la mortalidad ­odds ratio ajustada: 1,02 (intervalo de confianza al 95%: 1,001-1,04)­ pero no con el resultado funcional ­odds ratio ajustada de la escala de Rankin modificada = 3: 1,007 (intervalo de confianza al 95%: 0,99-1,025)­. Conclusiones. Nuestros resultados sugieren que una mayor VG tras la TM para el IIA de la circulación anterior es un factor de riesgo independiente de mortalidad a los tres meses. Los futuros ensayos deben evaluar el beneficio de reducir la VG en este contexto.

Effect of age at disease onset in the clinical profile of spondyloarthritis: a study of 1424 Brazilian patients.

OBJECTIVES: To analyse demographic and clinical variables in patients with disease onset before and after 40, 45 and 50 years in a large series of Brazilian SpA patients. METHODS: A common protocol of investigation was prospectively applied to 1424 SpA patients in 29 centres distributed through the main geographical regions in Brazil. The mean age at disease onset was 28.56 ± 12.34 years, with 259 patients (18.2%) referring disease onset after 40 years, 151 (10.6%) after 45 years and 81 (5.8%) after 50 years. Clinical and demographic variables and disease indices (BASDAI, BASFI, BASRI, MASES, ASQoL) were investigated. Ankylosing spondylitis was the most frequent disease (66.3%), followed by psoriatic arthritis (18%), undifferentiated SpA (6.7%), reactive arthritis (5.5%), and enteropathic arthritis (3.5%). RESULTS: Comparing the groups according to age of disease onset, those patients with later onset presented statistical association with female gender, peripheral arthritis, dactylitis, nail involvement and psoriasis, as well as negative statistical association with inflammatory low back pain, alternating buttock pain, radiographic sacroiliitis, hip involvement, positive familial history, HLA-B27 and uveitis. BASDAI, BASFI and quality of life, as well as physicians and patient's global assessment, were similar in all the groups. Radiographic indices showed worse results in the younger age groups. CONCLUSIONS: There are two different clinical patterns in SpA defined by age at disease onset: one with predominance of axial symptoms in the group with disease onset ≤ 40 years and another favouring the peripheral manifestations in those with later disease onset.

Hernia recurrence inventory: inguinal hernia recurrence can be accurately assessed using patient-reported outcomes.

PURPOSE: Relying solely on in-person encounters to assess long-term outcomes of hernia repair leads to substantial loss of information and patients lost-to-follow-up, hindering research and quality improvement initiatives. We aimed to determine if inguinal hernia recurrences could be assessed using the Ventral Hernia Recurrence Inventory (VHRI), a previously existing patient-reported outcome (PRO) tool that can be administered through the telephone and has already been validated for diagnosing ventral hernia recurrence. METHODS: A prospective, multicentric comparative study was conducted. Adult patients from two centers (United States and Brazil) at least 1 year after open or minimally invasive inguinal hernia repair were asked to answer the questions of the VHRI in relation to their prior repair. A physical exam was then performed by a blinded surgeon. Testing characteristics and diagnostic performance of the PRO were calculated. Patients with suspected recurrences were preferentially recruited. RESULTS: 128 patients were enrolled after 175 repairs. All patients answered the VHRI and were further examined, where a recurrence was present in 32% of the repairs. Self-reported bulge and patient perception of a recurrence were highly sensitive (84-94%) and specific (93-94%) for the diagnosis of an inguinal hernia recurrence. Test performance was similar in the American and Brazilian populations despite several baseline differences in demographic and clinical characteristics. CONCLUSION: The VHRI can be used to assess long-term inguinal hernia recurrence and should be reestablished as the Hernia Recurrence Inventory (HRI). Its implementation in registries, quality improvement efforts, and research could contribute to improving long-term follow-up rates in hernia patients.

Treatment with Bifidobacterium longum 51A attenuates intestinal damage and inflammatory response in experimental colitis.

This study evaluated the effects of Bifidobacterium longum 51A on the intestinal mucosa and inflammatory response in experimental colitis. Colitis was induced by administration of 3.5% dextran sodium sulphate (DSS) solution for 7 days. Two periods of administration were performed: treatment (T) group, mice received Bifidobacterium only during disease induction (7 days); total treatment (TT) group, mice received Bifidobacterium for 10 days before and during disease induction. The probiotic effects on intestinal permeability, inflammatory infiltrate, histological analysis, cytokines, chemokines and sIgA were evaluated. Bifidobacterium administration in the T group showed reduction in intestinal permeability and lower IL-1ß, myeloperoxidase, and eosinophil peroxidase levels compared to those in the colitis group (P<0.05). Bifidobacterium administration in the TT group attenuated severe lesions in the colon and reduced eosinophil peroxidase level (P<0.05). B. longum 51A treatment modality was more effective than total treatment and reduced the inflammatory response and its consequences on intestinal epithelium.

The challenge of early systemic sclerosis for the EULAR Scleroderma Trial and Research group (EUSTAR) community. It is time to cut the Gordian knot and develop a prevention or rescue strategy.

Early diagnosis of systemic sclerosis (SSc) may allow the start of treatment that could slow disease progression. For this reason early diagnosis of the disease is of pivotal importance. However, the lack of diagnostic criteria and valid predictors significantly limit patient evaluation and the use of potentially effective drugs in the earliest phase of SSc. Early SSc may be suspected on the basis of Raynaud's phenomenon, puffy fingers, autoantibodies and SSc capillaroscopic pattern. In practice, the aim is to have criteria for the diagnosis of very early SSc. The criteria that are proposed are obviously provisional and need to be validated: (a) initially through a Delphi technique; (b) thereafter perhaps using already available datasets; but (c) of critical importance, through prospective studies. Only after prospective studies can these potential criteria be considered validated. The consensus on criteria for the classification of very early SSc might be part of the evolving EULAR/ACR project of reclassification of SSc.

Combined open and laparoscopic approach for repair of flank hernias: technique description and medium-term outcomes of a single surgeon.

PURPOSE: A residual bulge in the lateral abdominal wall is a reason for patient dissatisfaction after flank hernia repair (FHR). We hypothesized that combining a laparoscopically-placed intraperitoneal mesh (IPOM) with onlay hernia repair performed through a small open incision would increase repair durability and decrease such residual bulges. We aim to report our medium-term outcomes with this technique. METHODS: Patients who have undergone FHR using the technique described above from March 2013 through June 2017 were identified in a prospectively maintained database. Outcomes of interest included surgical site infections (SSI), surgical site occurrences (SSO), surgical site occurrences requiring procedural intervention (SSOPI) and hernia recurrence. RESULTS: Sixteen patients were identified (62% females; mean age 59 ± 8 years, mean body mass index 29.5 kg/m2). Mean hernia width was. 6.4 ± 3 cm and 31% were recurrent hernias previously repaired through an onlay approach. Mean operative time was 159 ± 40 min, fascial closure was achieved in all cases, and there were no intraoperative complications. Median length of stay was 3 days (IQR 3-4), and there were no unplanned readmissions or reoperations. At a median 37-month follow-up (IQR 21-55), wound morbidity rate was 12.5% (2 seromas). There were no SSI/SSOPI and one hernia recurrence (6%) was detected at 12 months postoperatively. CONCLUSION: Combining laparoscopic IPOM with open onlay hernia repair resulted in low recurrence and acceptable wound morbidity rates, with no residual bulges noted at medium-term follow-up. Further studies with larger number of patients and other surgeon's experiences are necessary to determine the role of such technique in the surgical armamentarium for flank hernia repair.

Structural biology of membrane-acting peptides: conformational plasticity of anticoccidial peptide PW2 probed by solution NMR.

The bottleneck for the complete understanding of the structure-function relationship of flexible membrane-acting peptides is its dynamics. At the same time, not only the structure but also the dynamics are the key points for their mechanism of action. Our model is PW2, a TRP-rich, cationic peptide selected from phage display libraries that shows anticoccidial activity against Eimeria acervulina. In this manuscript we used a combination of several NMR techniques to tackle these difficulties. The structural features of the membrane-acting peptide PW2 was studied in several membrane mimetic environments: we compared the structural features of PW2 in SDS and DPC micelles, that were reported earlier, with the structure properties in different lipid vesicles and the peptide free in water. We were able to unify the structural information obtained in each of these systems. The structural constraints of the peptide free in water were fundamental for the understanding of plasticity necessary for the membrane interaction. Our data suggested that the WWR sequence is the region responsible for anchoring the peptide to the interfaces, and that this same region displays some degree of conformational order in solution. For PW2, we found that affinity is related to the aromatic region, by anchoring the peptide to the membrane, and specificity is related to the N- and C-termini, which are able to accommodate in the membrane due to its plasticity.

Analysis of the healthy rabbit lens surface using MAC Mode atomic force microscopy.

In this investigation healthy rabbit crystalline lenses were characterized by atomic force microscopy (AFM). The lenses were cut in slices with thickness with 1mm and thus, put after cortex distinct regions of nucleus and cortex for AFM examination. AFM analysis were carried out using a PicoSPM I operating in Mac Mode. We obtained topographic images of rabbit lenses and a quantitative analysis of the width and height of fibers for nucleus and cortex regions. The longitudinal section analysis of fibers in the nucleus region indicated structures with an average width of 200nm and average height of 200nm. The intershells distance was determined as 4microm. Fiber cell cross-section dimensions, longitudinal and transverse widths, could be estimated in these regions from the AFM images. Structures with average widths as small as 1.0microm are observed in the nucleus; the intershell distance is 4.0microm. In cortical regions, hexagonal structures with average longitudinal and transverse widths of 5.0mum and 3.0mum, respectively, were identified. Three-dimensional images of tissue sections with resolution on a nanometer scale were obtained. The potential of AFM analysis for characterizing healthy and pathologic lens tissues is discussed.

Dose-dependent in vitro inhibition of rabbit corneal matrix metalloproteinases by an extract of Pothomorphe umbellata after alkali injury.

The in vitro ability of Pothomorphe umbellata ethanolic crude extract to inhibit matrix metalloproteinase (MMP) in normal cornea and in cornea after alkali injury was demonstrated. Corneas of albino rabbits were injured with 1 N NaOH for 20 s. After 48 h the corneas were excised, homogenized and analyzed for MMP-9 (92 kDa), pro-MMP-2 (72 kDa) and MMP-2 (67 kDa) activity by gelatin zymography. The activity was also measured in untreated corneas. After electrophoresis of 20 microg protein, gels were incubated with 50, 100, or 250 microg/mL lyophilized hydroethanolic (1:1) root crude extract of P. umbellata standardized for 4-nerolidylcatechol (7.09%). The activity of the enzymes was compared with that of untreated gel. At 48 h after injury, the activity of all MMPs was increased compared with untreated eyes. When the gels were incubated with P. umbellata extract the activity of MMP-2, pro-MMP-2 and MMP-9 decreased in a dose-dependent manner. MMP-9 activity decreased by approximately 50% after incubation with 50 microg/mL and was completely abolished at 100 and 250 microg/mL of the extract. After incubation with 50 microg/mL the activity of pro-MMP-2 and MMP-2 also decreased by 50%. The activity of pro-MMP-2 was almost completely abolished after incubation with 250 microg/mL of the extract. For MMP-2 the incubation with 100 or 250 microg/mL of the extract of P. umbellata promoted a 10-fold decrease in activity. In conclusion, P. umbellata root crude extract can be useful as an alternative therapy to control MMP activity after corneal injury.