Asymmetrical elevation of esophagogastric junction pressure suggests hiatal repair contributes to antireflux surgery dysphagia.

The radial distribution of esophago-gastric junction (EGJ) pressures with regard to troublesome dysphagia (TDysph) after antireflux surgery is poorly understood. Before and after antireflux surgery, end-expiratory and peak-inspiratory EGJ pressures were measured at eight angles of 45° radial separation in patients with reflux disease. All 34 patients underwent posterior crural repair, then either 90° anterior (N = 13) or 360° fundoplication (N = 21). Dysphagia was assessed prospectively using a validated questionnaire (score range 0-45) and TDysph defined as a dysphagia score that was ≥5 above pre-op baseline. Compared with before surgery, for 90° fundoplication, end-expiratory EGJ pressures were highest in the left-anterolateral sectors, the position of the partial fundoplication. In other sectors, pressures were uniformly elevated. Compared with 90° fundoplication, radial pressures after 360° fundoplication were higher circumferentially (P = 0.004), with a posterior peak. Nine patients developed TDysph after surgery with a greater increase in end-expiratory and peak-inspiratory EGJ pressures (P = 0.03 and 0.03, respectively) and significantly higher inspiratory pressure at the point of maximal radial pressure asymmetry (P = 0.048), compared with 25 patients without TDysph. Circumferential elevation of end-expiratory EGJ pressure after 90° and 360° fundoplication suggests hiatal repair elevates EGJ pressure by extrinsic compression. The highly localized focal point of elevated EGJ pressure upon inspiration in patients with TDysph after surgery is indicative of a restrictive diaphragmatic hiatus in the presence of a fundoplication.

Swallowing activity assessed by ambulatory impedance-pH monitoring predicts awake and asleep periods at night.

INTRODUCTION: Voluntary muscle activity, including swallowing, decreases during the night. The association between nocturnal awakenings and swallowing activity is under-researched with limited information on the frequency of swallows during awake and asleep periods. AIM: The aim of this study was to assess nocturnal swallowing activity and identify a cut-off predicting awake and asleep periods. METHODS: Patients undergoing impedance-pH monitoring as part of GERD work-up were asked to wear a wrist activity detecting device (Actigraph(®)) at night. Swallowing activity was quantified by analysing impedance changes in the proximal esophagus. Awake and asleep periods were determined using a validated scoring system (Sadeh algorithm). Receiver operating characteristics (ROC) analyses were performed to determine sensitivity, specificity and accuracy of swallowing frequency to identify awake and asleep periods. RESULTS: Data from 76 patients (28 male, 48 female; mean age 56 ± 15 years) were included in the analysis. The ROC analysis found that 0.33 sw/min (i.e. one swallow every 3 min) had the optimal sensitivity (78 %) and specificity (76 %) to differentiate awake from asleep periods. A swallowing frequency of 0.25 sw/min (i.e. one swallow every 4 min) was 93 % sensitive and 57 % specific to identify awake periods. A swallowing frequency of 1 sw/min was 20 % sensitive but 96 % specific in identifying awake periods. Impedance-pH monitoring detects differences in swallowing activity during awake and asleep periods. Swallowing frequency noticed during ambulatory impedance-pH monitoring can predict the state of consciousness during nocturnal periods.

[Colorectal polyps: update on diagnosis]. / Pólipos colorectales: actualización en el diagnóstico.

Histological diagnosis determines the clinical behavior of colorectal polyps. Recently new types of polyps have been described and the classification has become wider and more complex. Our aim is update the current concepts in the knowledge of colorectal polyps.

[Increase of intraepithelial lymphocytes in patients with irritable bowel syndrome]. / Incremento de Linfocitos Intraepiteliales en Pacientes con Sindrome de Intestino Irritable.

Several studies have shown increased numbers of intraepithelial lymphocytes (IEL), mast cells, enterochromaffin cells in colonic mucosa of patients with Irritable Bowel Syndrome (IBS). Many of these findings are based is based on immunohistochemistry results, which is not available in general hospitals. Our objective is to study the histological findings observed in colon biopsies from patients with IBS compared with a group without IBS, using only histochemistry. Twenty five (25) patients were included: 16 with IBS and 9 without IBS. We found increased numbers of IEL in patients with IBS (p=0,002). A group of patients with IBS (41.9%) who fulfilled histological criteria for lymphocytic colitis were excluded. There was no significant difference in mast cells, enterochromaffin cells or eosinophils.

Optimisation of a batch thermal combustion method using a tube furnace oxidation system (pyrolyser) and LSC for carbon-14 determination in environmental matrices.

Accelerator mass spectrometry and benzene synthesis coupled with liquid scintillation spectrometry are often used for accurate measurements of 14C activity in the environmental matrices. Thermal oxidation is one of the methods employed for 14C determination in environmental matrices. In this method, the sample is oxidised at high temperature (600-900 °C) to convert carbon species to CO2 and trapped in an amine-based absorber for determining the activity in a liquid scintillation counting (LSC) system. In this study, the performance of a commercially available tube furnace system (pyrolyser), for batch combustion of samples, was evaluated for the determination of 14C specific activity in terrestrial biota samples. Significant improvements over the manufacturer specified method, which is primarily designed for analysis of samples with activity well above the environmental background level, was implemented to achieve accurate determination of 14C specific activity at ambient background level. In the improved method, the CO2 produced from the combustion of the sample was isolated from the combustion products through cryogenic trapping and then absorbed in the absorber (Carbo-Sorb E) through a simple off-line transfer process. This allowed (i) optimisation of CO2 absorption by the absorber (2.2477 g of CO2/10 mL), (ii) achieving good accuracy and precision in the measurements, and a minimum detectable activity value of 13 Bq kg-1C for a counting time of 300 min (7 Bq kg-1C for 1000 min), (iii) avoiding uncertainty associated with the determination of recovery of 14C in the combustion and trapping process, and (iv) elimination of the need for an independent determination of carbon content (%) for expressing the results in terms of 14C specific activity. The method is capable of yielding accurate results with a deviation of <2.4% from the target value for IAEA C3 quality assurance reference material (with a relative standard deviation of 1.40%, and relative error of 0.34%). The combined uncertainty (1σ) associated with the measurements was computed to be 3.4%. Upon optimisation, the suitability of the method for the determination of 14C specific activity in typical terrestrial biota samples of clean air region (region not affected by local anthropogenic sources) and for the quantification of a small increase in the 14C activity above ambient levels in the vicinity of a nuclear power plant is demonstrated.

Low serological positivity in patients with histology compatible with celiac disease in Perú.

OBJECTIVE: To study the frequency of positive serology for celiac disease (CD) in patients with duodenal biopsies suggestive of this disease. MATERIAL AND METHODS: Cross sectional study. We included patients with duodenal biopsies histologically compatible with CD and antigliadin, antiendomysial and IgA antitransglutaminase antibodies. We defined a "case" of CD if there was a positive biopsy and either antiendomisial or antitransglutaminase positive antibodies. RESULTS: Thirty one patients were included in our study. Six were antiendomysial positive and 5 antitransglutaminase positive while the antigliadin was positive in 14 cases. Therefore, out of 31 patients only 10 had a serology compatible with CD and only one had positive both antibodies, antiendomysial and antitransglutaminase. CONCLUSIONS: a) We have found that most of the duodenal biopsies compatible with CD are not diagnosed with positive serology; and b) we found a low correlation between serological diagnostic tests.

Influence of multi-walled carbon nanotubes on the physico-chemical and biological responses of chitosan-based hybrid hydrogels.

Photoresponsive membranes were successfully obtained by combining chitosan (CS), poly(vinyl alcohol) (PVA) crosslinked with genipin (GEN) and filled with multi-walled carbon nanotubes (MWCNTs). It was demonstrated that adding a small quantity (0.01% w/v) of MWCNTs conferred to those nanocomposite hybrid hydrogels an outstanding photomechanical response under infrared irradiation. Moreover, it was observed that MWCNTs enhanced the crystallinity, increased the elastic modulus but did not contribute to the thermal stability of the nanocomposite hybrid hydrogels. The swelling capacity and contact angle values of these materials were modified through the addition of MWCNTs, and the offered free OH and NH2 functional groups in their current chemical structures. These functional groups - on hybrid hydrogels' surfaces - also enhanced the adhesion and proliferation of human dermal fibroblast cells, showing typical morphologies and sizes. Additionally, non-cytotoxic effects were observed for these nanocomposite hybrid hydrogels, suggesting their potential use in tissue engineering and biomedical applications. Chemical compounds studied in this article: Chitosan (PubChem CID: 71853); Polyvinyl alcohol (PubChem CID: 11199); Genipin (PubChem CID: 442424).

Natural and artificial radionuclides in a marine core. First results of 236U in North Atlantic Ocean sediments.

There are very few data available of 236U in marine sediment cores. In this study we present the results from the first oceanic depth profile of 236U in a sediment core sampled in the North Atlantic Ocean, at the PAP site (4500 m depth, Porcupine Abyssal Plain (PAP) site, 49°0' N, 16°30' W). Additionally, the sediment core was radiologically characterized through the measurement of anthropogenic 137Cs, 239Pu, 240Pu, 129I and 14C and natural 210Pb, 40K and 226Ra. The measured 236U concentrations decrease from about 90·106 at g-1 at the seafloor down to 0.5·106 at g-1 at 6 cm depth. They are several orders of magnitude lower than the reported values for soils from the Northern Hemisphere solely influenced by global fallout (i.e. from 2700·106 to 7500·106 at g-1). 236U/238U atom ratios measured are at least three orders of magnitude above the estimated level for the naturally occurring dissolved uranium. The obtained inventories are 1·1012 at m-2 for 236U, 80 Bq m-2 for 137Cs, 45 Bq m-2 for 239+240Pu and 2.6·1012 at m-2 for 129I. Atomic ratios for 236U/239Pu, 137Cs/236U and 129I/236U, obtained from the inventories are 0.036, 0.11 and 2.5 respectively. Concentration profiles show mobilization probably due to bioturbation from the abundant detritivore holothurian species living at the PAP site sea-floor. The range of 236U, 137Cs, 239+240Pu and 129I values, inventories and ratios of these anthropogenic radionuclides are more similar to the values due to fall-out than values from a contribution from the Nuclear Fuel Reprocessing Plants dispersed to the south-west of the North Atlantic Ocean. However, signs of an additional source are detected and might be associated to the nuclear wastes dumped on the Eastern North Atlantic Ocean.

Development of an electrochemical biosensor for the determination of triglycerides in serum samples based on a lipase/magnetite-chitosan/copper oxide nanoparticles/multiwalled carbon nanotubes/pectin composite.

A very sensitive electrochemical biosensor to determine totals triglycerides (TGs) in serum samples has been developed. It is based on the electrochemical oxidation of glycerol at glassy carbon electrodes modified with magnetic nanoparticles bonded to lipase enzyme and copper oxide nanoparticles, both supported on a multiwalled carbon nanotubes/pectin dispersion. Glycerol is produced by enzymatic reaction between the TGs present in samples and the lipase immobilized. The quantification of triglycerides was performed by amperometric measurements. The proposed electrochemical biosensor improves the performance of others methods developed for the TGs quantification. The determination of TGs does not need a pretreatment of serum samples. The PLS-1 algorithm was used for the quantification of TGs. According to this algorithm, the of detection and quantification limits were from 3.2 × 10-3 g L-1 to 3.6 × 10-3 g L-1, and from 9.6 × 10-3 to 1.1 × 10-2 g L-1, respectively. The sensitivity was 1.64 × 10-6 A L g-1. The proposed electrochemical biosensor exhibited a very good performance, a stability of 20 days, very good reproducibility and repeatability, and it is presented as a very good alternative for the determination of TGs in human serum clinical samples.

Increased homocysteine plasma levels in breast cancer patients of a Mexican population.

AIM: Hyperhomocysteinemia has been associated with different pathologies, including cardiovascular diseases, hypertension, diabetes, and breast cancer (BC). To examine the differences in total homocysteine (tHcy) plasma levels, we compared healthy women to BC patients from a Mexican population. MATERIALS AND METHODS: The tHcy plasma levels were measured using high-performance liquid chromatography with a fluorescence detector in 89 female controls and 261 BC patients. RESULTS: The observed plasma tHcy levels were significantly higher among the BC patients (11.1019 ± 5.9161 µmol/l) compared to the controls (9.1046 ± 1.3213 µmol/l) (p = 0.002), and these differences were evident when stratified by age (≥ 50 years old), menopause status, overweight and obesity, miscarriages, node metastases, progression, subtype classification (luminal, Her2 and triple negative) and nonresponse to chemotherapy. CONCLUSIONS: The tHcy plasma levels could be a good marker for the progression and chemosensitivity of BC in the analyzed sample from a Mexican population.

[Immunoexpression of p53 and cyclin D1 in adenomas of the gallbladder]. / Inmunoexpresión de p53 y ciclina D1 en adenomas de vesícula biliar.

INTRODUCTION: Gallbladder adenomas are infrequent neoplasms whose relation to adenocarcinoma is not well understood. It has been suggested that adenomas and adenocarcinomas follow different molecular pathways. MATERIAL AND METHODS: This is a comparative, cross-sectional study in which we compared p53 and D1 cyclin expression in adenomas and adenocarcinomas of the gallbladder. RESULTS: We included 12 cases in each group. Expression of p53 occurred in 83.3% of adenocarcinomas and in 16.6% of adenomas (p = 0.003). D1 cyclin was expressed in a similar number of adenomas and adenocarcinomas. CONCLUSION: Our results support the hypothesis that p53 is an important step in the pathogenesis of adenocarcinomas but not of adenomas of the gallbladder. D1 cyclin is apparently a common pathway involved in the genesis of both tumors.

[E-cadherin molecular expresion in the diffuse and intestinal types of gastric adenocarcinoma. A report from Lima, Peru]. / E-cadherina: expresión molecular en carcinomas de estómago de tipo difuso y tipo intestinal. Estudio realizado en Lima, Perú.

OBJECTIVE: Signet ring carcinoma of the stomach is well known to be more aggressive and infiltrating than adenocarcinoma. Different studies have proposed that signet ring cell carcinoma would be more infiltrating because of the loss of E-cadherin expression, this cadherin is a class of protein cell membrane protein which plays an important role in cell-adhesion. METHODS: We carried out a transversal comparative study, in order to measure the E-cadherin expression in 10 cases of signet ring cell and in 10 cases of adenocarcinoma, with help of immunohistochemistry. RESULTS: We found a bigger expression of E-cadherin in adenocarcinomas (100%) than signet ring cell carcinoma (40%), this difference was significative using Fisher test (p = 0,011). The loss of E-cadherin would explain the bigger infiltrating capacity in comparison to adenocarcinoma.

Prevalence and potential risk factors for organophosphate and pyrethroid resistance in Boophilus microplus ticks on cattle ranches from the State of Yucatan, Mexico.

A cross-sectional study was carried out in order to investigate the association between management risk factors and the prevalence of organophosphate (OP) and synthetic pyrethroid (SP) resistance in Boophilus microplus ticks in Yucatan State, Mexico. Ninety-eight cattle ranches were randomly selected and a sample of 20-30 engorged female B. microplus ticks was collected at each. The modified larvae packet test was used to detect OP and SP tick resistance. A questionnaire was administered on each ranch. For risk factors, four reference types of response were used: Tuxpan (resistant to coumaphos, chlorfenvinphos and diazinon), Parkhurst (resistant to flumethrin, deltamethrin and cypermethrin), Lamington (resistant to flumethrin in absence of deltamethrin and cypermethrin) and Marmor (resistant to flumethrin and cypermethrin in absence of flumethrin). A primary screening was performed using 2 x 2 contingency tables of exposure variables. All variables with p < or = 0.20 were analyzed by a logistic regression. The prevalence of B. microplus resistance to OP and SP groups were 83.70% and 66.32%, respectively. The prevalence for a single chemical compound was: diazinon (80.60%), coumaphos (45.90%), chlorfenvinphos (35.70%), flumethrin (63.28%), deltamethrin (61.22%), and cypermethrin (59.18%). The prevalence type of response was: Tuxpan (34.16%), Parkhurst (58.16%), Lamington (4.08%), and Marmor (4.08%). The use of a different tick control program was the risk management factor associated with the Parkhurst type of response. It is concluded that the prevalence of cattle ranches with B. microplus resistant to OPs and SPs in Yucatan, Mexico, is a current problem, and a treatment interval of > or =6 times/year and use of a tick control program (macrocyclic lactones and pasture burn) different from standard recommended programs are risk factors associated with the Parkhurst type of response.

Prevalence and potential risk factors for amitraz resistance in Boophilus microplus ticks in cattle farms in the State of Yucatan, Mexico.

Southern cattle tick, Boophilus microplus, control in the Mexican tropics is based on the application by spray, dip or pour-on of acaricides. In Mexico the first report of ticks resistant to amitraz was reported in 2002. Amitraz resistance affecting the cattle industry of Yucatan State, Mexico, has not been investigated. A cross-sectional study was carried out in order to investigate the possible association between management risk factors and the prevalence of B. microplus ticks resistant to amitraz in Yucatan, Mexico. Ninety-eight cattle farms were randomly selected and a sample of 20-30 engorged B. microplus females was collected from at least 10 cattle from each farm. Collected ticks were taken to the laboratory where the larval progeny were obtained. The modified larval immersion test was used to detect ticks resistant to amitraz. A discriminating dose of 0.0002% amitraz was used. A questionnaire was applied on each collaborating farm. For the statistical analysis a 2x2 contingency table was used to identify potential risk factors. The prevalence of farms with B. microplus resistant to amitraz was 19.40%. However, even though tick resistance to amitraz is a present problem there was no evidence that it was associated with the risk factors analyzed in this survey.

Influence of natural and synthetic crosslinking reagents on the structural and mechanical properties of chitosan-based hybrid hydrogels.

The objective of this work was to correlate the physical and chemical properties of chitosan/poly(vinyl alcohol)/genipin (CS/PVA/GEN) and chitosan/poly(vinyl alcohol)/glutaraldehyde (CS/PVA/GA) hydrogels with their structural and mechanical responses. In addition, their molecular structures were determined and confirmed using FTIR spectroscopy. The results indicated that the hybrid hydrogels crosslinked with genipin showed similar crystallinity, thermal properties, elongation ratio and structural parameters as those crosslinked with glutaraldehyde. However, it was found that the elastic moduli of the two hybrid hydrogels were slightly different: 2.82±0.33MPa and 2.08±0.11MPa for GA and GEN, respectively. Although the hybrid hydrogels crosslinked with GEN presented a lower elastic modulus, the main advantage is that GEN is five to ten thousand times less cytotoxic than GA. This means that the structural and mechanical properties of hybrid hydrogels crosslinked with GEN can easily be tuned and could have potential applications in the tissue engineering, regenerative medicine, food, agriculture and environmental industries.

B-mode ultrasound scanning in the diagnosis of renal lesions.

The use and value of a relatively new diagnostic modality, ultrasound, in the diagnosis of renal masses are discussed. Several examples are presented.

Accumulation and transformation of DSP toxins in mussels Mytilus galloprovincialis during a toxic episode caused by Dinophysis acuminata.

The time course of several outbreaks of the diarrhetic shellfish poisoning (DSP) producer Dinophysis acuminata and the consequent kinetic of accumulation and loss of toxins in mussels Mytilus galloprovincialis feeding on them was studied. Samples of mussels and seawater were frequently (2-3 times a week) collected from a raft in the Ri;a de Vigo. DSP toxins content of mussels and water was analyzed by HPLC-FD and phytoplankton was quantified in an inverted light microscope. Only okadaic acid (OA) and some of its conjugated forms (OA CF), estimated by enzymatic hydrolysis, were found in the plankton samples obtained, comprised mainly of D. acuminata cells. The main accumulated form in mussels was OA reaching a maximum of 10.1 microg OA g(-1) in the digestive gland (d.g.) in 16 days, falling below the quarantine level (ca. 2 microg OA g(-1) d.g.) by 45 days. The low polarity conjugated forms (LPCF), estimated by hexane extraction, accounted for 6.2% of the total toxin burden of the mussels. To quantify the rates of the processes involved in the accumulation, transformation and loss of the toxins, two dynamic models, a one-compartment and a two-compartment, including OA and its conjugated forms as variables were designed and implemented. The one-compartment model provided a good fit to the OA and LPCF actual data (r(2)=0.92 and r(2)=0.94, respectively). The two-compartment model did not fit the data markedly better than its one-compartment counterpart (r(2)=0.93 and r(2)=0.95, for OA and LPCF, respectively). High hydrolysis rates were estimated for most of the OA CF, which means that these forms came largely from the ingested plankton. The low estimated acylation rates support the previous point and suggest that the formation of LPCF by direct acylation of the OA is of little importance in M. galloprovincialis. Only in cases where the intoxication period is very long, can the formed acyl-derivatives be important, because they seem to accumulate for a long time in the mussels, as suggested by the low hydrolysis and depuration rates estimated from model fitting.

[The validation of checklists for the inhalation technic for the pressurized cartridge and the Turbuhaler]. / Validación de listas de comprobación de la técnica de inhalación para cartucho presurizado y Turbuhaler.

OBJECTIVE: To determine the intra- and interobserver validity and reliability of two checklists for inhalation technique with a pressurized inhaler (PI) and the Turbuhaler. MATERIAL AND METHODS: Transversal descriptive study performed at an urban health clinic in Gijón (Spain). Thirty-four patients, over 14 years of age but younger than 65, who used a PI and 35 who used a Turbuhaler were chosen randomly from among patients in our health clinic practice. The results obtained with each list by two observers were compared with those obtained by electronic monitors (test pattern). Each patient performed 3 inhalation maneuvers. RESULTS: Comparison with the test pattern showed that, between 35.2% and 47% of patients used the PI technique correctly, whereas 74.2% inhaled correctly using the Turbuhaler. The sensitivity of the PI checklist ranged from 62.5 to 91.6 and specificity ranged from 88.8 to 94.4. The sensitivity of the Turbuhaler checklist ranged from 50 to 76.9 specificity ranged from 66.6 to 88.8. Intra-observer agreement (Kappa index) was 0.62 to 0.74 for the PI checklist and between 0.77 and 0.81 for the Turbuhaler list. Interobserver agreement (Kappa index) was 0.68 to 0.81 for the PI list and 0.53 to 0.60 for the Turbuhaler list. CONCLUSIONS: The two checklists are valid instruments and offer good intra- and interobserver reliability, permitting easy identification of patients who perform the inhalation technique incorrectly.

Ophthalmic features of the organoid nevus syndrome.

BACKGROUND/PURPOSE: The organoid nevus (sebaceous nevus) syndrome is characterized primarily by cutaneous sebaceous nevus, seizures, and epibulbar choristomas. On the basis of ophthalmoscopic and computed tomographic studies, a yellow fundus lesion recently observed in this syndrome has been called a coloboma by some investigators and a choroidal osteoma by others. This study was undertaken to review our personal experience with the organoid nevus syndrome, to review the English language literature on the subject, and to address some misconceptions regarding its ocular manifestations. METHODS: We reviewed the records of patients with the organoid nevus syndrome who were personally evaluated by the investigators. The ocular findings were studied in more detail, with emphasis on the epibulbar and fundus lesions. RESULTS: We identified five patients with the organoid nevus syndrome. Four had a classic sebaceous nevus in the facial and scalp area, and 2 had seizures and arachnoid cysts. All 5 patients had an epibulbar tumor, which proved to be a complex choristoma in one case that was studied histopathologically. A characteristic ophthalmoscopic feature, observed in the 4 patients with clear ocular media, was a flat yellow discoloration of the posterior fundus, of variable size and shape, which appeared to correlate with a dense plaque noted on ultrasonography and computed tomography. In 1 case, histopathologic examination showed that this posterior lesion contained intrascleral cartilage. CONCLUSIONS: Our observations and a review of the literature indicated that the organoid nevus syndrome has varied manifestations. Like the closely related phakomatoses, it often occurs as a forme fruste, without full expression of the syndrome. The most important ocular manifestations are an epibulbar mass, compatible with a complex choristoma, and focal yellow discoloration in the fundus, probably related to intrascleral cartilage.

Mechanical and structural response of a hybrid hydrogel based on chitosan and poly(vinyl alcohol) cross-linked with epichlorohydrin for potential use in tissue engineering.

The development and characterization of a hybrid hydrogel based on chitosan (CS) and poly(vinyl alcohol) (PVA) chemically cross-linked with epichlorohydrin (ECH) is presented. The mechanical response of these hydrogels was evaluated by uniaxial tensile tests; in addition, their structural properties such as average molecular weight between cross-link points (Mcrl), mesh size (DN), and volume fraction (v(s)) were determined. This was done using the equivalent polymer network theory in combination with the obtained results from tensile and swelling tests. The films showed Young's modulus values of 11 ± 2 MPa and 9 ± 1 MPa for none irradiated and ultraviolet (UV) irradiated hydrogels, respectively. The cell viability was assessed using Calcein AM and Ethidium homodimer-1 assay and environmental scanning electron microscopy. The 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan thiazolyl blue formazan (MTT Formazan assay) results did not show cytotoxic effects; this was in good agreement with nuclear magnetic resonance and fourier transform infrared spectroscopies; their results did not show traces of ECH. This indicated that after the crosslinking process, there was no free ECH; furthermore, any possibility of ECH release in the construct during cell culture was discarded. The CS-PVA-ECH hybrid hydrogel allowed cell growth and extracellular matrix formation and showed adequate mechanical, structural, and biological properties for potential use in tissue engineering applications.