Conditioned breathing depression during neonatal life as a function of associating ethanol odor and the drug's intoxicating effects.

Fetal and neonatal ethanol-related alterations upon the respiratory system have been described in different mammals. Studies also indicate that perinates learn about the sensory attributes of ethanol and associate them with diverse physiological effects of the state of intoxication. The present study was conducted in rat neonates during a developmental stage equivalent to the third human gestational trimester. The major goal was to analyze the consequences of ethanol odor exposure, the state of intoxication, or the temporal contiguity between these factors upon breathing patterns. The main findings were as follows: (a) a conditioned breathing depression was observed following few trials defined by the association between ethanol odor and the state of intoxication and (b) sequential exposure to ethanol sensitizes the organism to the drug's respiratory depressant effects without affecting ethanol metabolism. These results indicate that early breathing disruptions caused by ethanol can be determined or modulated via learning processes. © 2016 Wiley Periodicals, Inc. Dev Psychobiol 58:670-686, 2016.

CD133 is a selective marker of CRC?

AIM: The aim of our study is to evaluate the surface glycoprotein CD133 as marker of cancer stem cells, as independent prognostic pattern of survival and its positive expression ratio to a chemotherapy increased resistance. METHODS: The study include our patient, affected by colorectal cancer (CRC) and underwent to surgery at University Hospital of Parma, with curative intent, with a follow up of 5 years; 47 cases were considered. All the cancer-case was considered independently by the histological grade. The monoclonal antibody CD133/1 (clone AC133-MAC, Miltenyi Bioetec, Auburn CA 95602, USA) that recognizes the epitope 1 of CD133 was utilized for the immunohistochemical process. RESULTS: On the total of 47 patients taken in exam, 8 were excluded for lack of date, 13 were lost during the follow-up. The final number of patients included in the study was 26(17 males and 9 females), medium age of 72.2 years. 2 Stage I, 8 Stage II A, 1 II B, 2 III A, 5 III B, 5 IIIC and 3 IV. Despite for 1, 25 on 26 patients were positive to CD133 (96.5 %), with different dye intensity, directly related at the positive cell pull. The CD133 positivity wasn't therefore related at any other clinic-pathological characteristic. CONCLUSION: The results obtained from our study goes in the same direction with others, that confirm a high representation of CD133 on the colic tumoral epithelium. It will be appropriate to do prospected and randomized studies, with a larger casistic, utilizing similar methods and a patients populations with more uniform characteristics, to verify the real role of CD133 and other molecules potentially marker of tumoral stem cell (TSC).

Use of preoperative visceral echo-color-Doppler in patients candidates to colonic surgery: preliminary report.

AIM: Postsurgical paralytic ileus is by definition an ileal paralysis longer than three days (72 hours) after a surgery on the gastrointestinal tract. At colorectal surgery we have performed on all candidates a visceral echo-color-Doppler to find a potential correlation with cardiovascular risk factors. METHODS: We have tested patients undergone to colorectal surgical resection performed by laparoscopic and laparotomic surgery, looking for their atherosclerosis status using ultrasound scan, postsurgical complication, bowel digestive function, anastomotic leak. We have also analyzed for each case the value of glycemia, azotemia, creatinemia, cholesterolemia, triglyceridemia, leukocytemia, mean cell volume, hemoglobinemia, albuminemia and moreover age, disease, pathology localization, kind of surgery, weight and height, body mass index (BMI), ASA status (American Society of Anesthesiologists, electrocardiographic distortions, nicotine dependency, diabetes mellitus type I and II). RESULTS: The study enrolled 23 patients, 10 male and 13 female. Middle age was 68.65 ± 11.85 years (range 39-90). In the female subgroup mean age was 69.48 years (range 39-90), while in the male subgroup it was 68 years (range 54-81). In 17 cases out of 23 (73.9%) there was a delay in digestive function, of over 72 hours, with a mean time duration of the paralytic ileus of 4.74 ± 1.60 days (range 3-9). Furthermore a statistically significant correlation between albuminemia and hemoglobinemia presurgery values and lower sierical albuminemia presurgery values in patients who were canalized too late (P=0.03; P=0.041) was found. The non-parametrical values analysis sec. Kruskal-Wallis emphasized a significant correlation between the canalization day, the elettrocardiographic evidence of the pathological situation (P=0.023) and the patient's smoking history (0.023). Another significant value was the creatininemia value: lower values of creatininemia were related to a delayed canalization (P=0.035). CONCLUSION: The statistical analysis does not allow to highlight any correlation between the ultrasound diagnosis of atherosclerosis and the delayed canalization.

Right colon laparoscopic resection with three-trocar access and associated gynecological procedures in patients with colorectal cancer and ovarian metastases.

BACKGROUND: Right laparoscopic colectomy was introduced to colorectal surgery later than the left colon procedure. Three-trocar laparoscopy has already been used successfully in the treatment of gynecological cancers. In the present study, we aimed to analyze the feasibility of performing an associated gynecological procedure following abdominal laparoscopic exploration and to evaluate the suitability of laparoscopic right colectomy for treating elderly patients. METHODS: We conducted a review of prospectively collected data on 100 consecutive patients who were treated with right laparoscopic colectomy using three trocars from January 2005 to April 2010. We recorded the patients' age (<70 or > 70 years), ASA status, body mass index (BMI), pain on postoperative days 1 and 2 (POD 1, 2), nodes retrieved, laparotomic conversion, mean operative time, time to intestinal recovery, and length of postoperative stay. RESULTS: All subjects were treated for cancer. Conversion to the laparotomic procedure was performed in 13/100, with no difference in terms of age. Operative time was longer for laparotomic conversion (p <0.05), with a longer postoperative stay. Elderly patients had higher ASA scores (p < 0.005); age did not influence the conversion rate or BMI status. Pain on POD 1 and 2 differed between the laparotomic and laparoscopic groups (p <0.0001). Associated procedures were performed in five subjects (3 oophorectomy and 2 cholecystectomy). CONCLUSIONS: Laparoscopy using the three-trocar technique is a safe procedure for treating colon cancer, including in elderly patients, and enables associated gynecological laparoscopic procedures to be performed.

Early ethanol pre-exposure alters breathing patterns by disruptions in the central respiratory network and serotonergic balance in neonate rats.

Early ethanol exposure alters neonatal breathing plasticity. Respiratory EtOH's effects are attributed to central respiratory network disruptions, particularly in the medullary serotonin (5HT) system. In this study we evaluated the effects of neonatal pre-exposure to low/moderate doses upon breathing rates, activation patterns of brainstem's nuclei and expression of 5HT 2A and 2C receptors. At PD9, breathing frequencies, tidal volumes and apneas were examined in pups pre-exposed to vehicle or ethanol (2.0 g/kg) at PDs 3, 5 and 7. This developmental stage is equivalent to the 3rd human gestational trimester, characterized by increased levels of synaptogenesis. Pups were tested under sobriety or under the state of ethanol intoxication and when subjected to normoxia or hypoxia. Number of c-Fos and 5HT immunolabelled cells and relative mRNA expression of 5HT 2A and 2C receptors were quantified in the brainstem. Under normoxia, ethanol pre-exposed pups exhibited breathing depressions and a high number of apneas. An opposite phenomenon was found in ethanol pre-treated pups tested under hypoxia where an exacerbated hypoxic ventilatory response (HVR) was observed. The breathing depression was associated with an increase in the neural activation levels of the raphe obscurus (ROb) and a high mRNA expression of the 5HT 2A receptor in the brainstem while desactivation of the ROb and high activation levels in the solitary tract nucleus and area postrema were associated to the exacerbated HVR. In summary, early ethanol experience induces respiratory disruptions indicative of sensitization processes. Neuroadaptive changes in central respiratory areas under consideration appear to be strongly associated with changes in their respiratory plasticity.

Laparoscopic treatment of sigmoid colon intussusception by large malignant tumor. Case report.

Intestinal intussusception is rare in adults, but common in children. The ileocolic or appendiceal types are more frequent compared to the colo-colic one. We report successful laparoscopic left hemicolectomy in a patient with intussusception caused by a sigmoid tumor. Abdominal CT demonstrated a colo-colic intussusception at the level of the tumoral lesion with dilation of the proximal colon. The patient underwent urgent laparoscopic oncologically radical left hemicolectomy. A 10 cm Pfannenstiel incision allowed the removal of the resected segment. The laparoscopic approach was feasible because the dilation was moderate; however, if intussusception is due to cancer, laparoscopy can be safely performed if a correct and prompt diagnosis is achieved following oncologic criteria.

Brief ethanol exposure and stress-related factors disorganize neonatal breathing plasticity during the brain growth spurt period in the rat.

RATIONALE: The effects of early ethanol exposure upon neonatal respiratory plasticity have received progressive attention given a multifactorial perspective related with sudden infant death syndrome or hypoxia-associated syndromes. The present preclinical study was performed in 3-9-day-old pups, a stage in development characterized by a brain growth spurt that partially overlaps with the 3rd human gestational trimester. METHODS: Breathing frequencies and apneas were examined in pups receiving vehicle or a relatively moderate ethanol dose (2.0 g/kg) utilizing a whole body plethysmograph. The experimental design also considered possible associations between drug administration stress and exteroceptive cues (plethysmographic context or an artificial odor). Ethanol exposure progressively exerted a detrimental effect upon breathing frequencies. A test conducted at PD9 when pups were under the state of sobriety confirmed ethanol's detrimental effects upon respiratory plasticity (breathing depression). RESULTS: Pre-exposure to the drug also resulted in a highly disorganized respiratory response following a hypoxic event, i.e., heightened apneic episodes. Associative processes involving drug administration procedures and placement in the plethysmographic context also affected respiratory plasticity. Pups that experienced intragastric administrations in close temporal contiguity with such a context showed diminished hyperventilation during hypoxia. In a 2nd test conducted at PD9 while pups were intoxicated and undergoing hypoxia, an attenuated hyperventilatory response was observed. In this test, there were also indications that prior ethanol exposure depressed breathing frequencies during hypoxia and a recovery normoxia phase. CONCLUSION: As a whole, the results demonstrated that brief ethanol experience and stress-related factors significantly disorganize respiratory patterns as well as arousal responses linked to hypoxia in neonatal rats.

Prenatal ethanol exposure modifies locomotor activity and induces selective changes in Met-enk expression in adolescent rats.

Several studies suggest that prenatal ethanol exposure (PEE) facilitates ethanol intake. Opioid peptides play a main role in ethanol reinforcement during infancy and adulthood. However, PEE effects upon motor responsiveness elicited by an ethanol challenge and the participation of opioids in these actions remain to be understood. This work assessed the susceptibility of adolescent rats to prenatal and/or postnatal ethanol exposure in terms of behavioral responses, as well as alcohol effects on Met-enk expression in brain areas related to drug reinforcement. Motor parameters (horizontal locomotion, rearings and stereotyped behaviors) in pre- and postnatally ethanol-challenged adolescents were evaluated. Pregnant rats received ethanol (2g/kg) or water during gestational days 17-20. Adolescents at postnatal day 30 (PD30) were tested in a three-trial activity paradigm (habituation, vehicle and drug sessions). Met-enk content was quantitated by radioimmunoassay in several regions: ventral tegmental area [VTA], nucleus accumbens [NAcc], prefrontal cortex [PFC], substantia nigra [SN], caudate-putamen [CP], amygdala, hypothalamus and hippocampus. PEE significantly reduced rearing responses. Ethanol challenge at PD30 decreased horizontal locomotion and showed a tendency to reduce rearings and stereotyped behaviors. PEE increased Met-enk content in the PFC, CP, hypothalamus and hippocampus, but did not alter peptide levels in the amygdala, VTA and NAcc. These findings suggest that PEE selectively modifies behavioral parameters at PD30 and induces specific changes in Met-enk content in regions of the mesocortical and nigrostriatal pathways, the hypothalamus and hippocampus. Prenatal and postnatal ethanol actions on motor activity in adolescents could involve activation of specific neural enkephalinergic pathways.

Standardized laparoscopic right hemicolectomy technique for colon cancer.

AIM: We analysed our experience of laparoscopic surgical treatment vs traditional surgery of right colon cancer. METHODS: A series of 27 patients was treated from January 2001 to December 2005 out of a total of 927 surgical colorectal operations in the same period (147 with the laparoscopic approach). Inclusion and exclusion criteria are reported. We compared this group with 25 patients treated by the same surgical group with open surgery. The mean operative time, the distance from the distal margin of resection, the number of lymphnodes, the mean period of canalization and the mean hospital stay are reported. RESULTS: In the laparoscopic group, the mean operative time was 124.8+/-36.3 min vs open surgery group of 94+/-23.6 min; the distance from the distal margin was 6.7+/-3.1 cm vs 6.4+/-2.1 cm; number of lymphnodes was 15.2+/-4.3 vs 18.7+/-2.9 nodes; and canalization 1.7+/-0.9 vs 2.7+/-0.7 days. The hospital stay was 6.8+/-1.7 vs 7.2+/-0.8 days. CONCLUSIONS: We consider laparoscopic right colon resection a safe procedure but it needs good laparoscopic practice and the observance of inclusion criteria.

Complications of percutaneous endoscopic gastrostomy: a surgical experience.

AIM: Percutaneous endoscopic gastrostomy (PEG) is a practical and safe option to place an alimentary gastrostomy. We observed that a relevant rate of complications are related to management of PEG. PATIENTS AND METHODS: We registered the patients treated in our Unit from September 1994 to December 2005. We placed 293 PEG (243 pts). Preferably using a tube 16 Fr, in 7 cases 18 Fr, in 21 cases 20 Fr and only in 3 cases 9 Fr. The median age was 69.8 years; ratio female:male 3:1. In 67 cases the treatment was carried out in not hospitalized patients. RESULTS: The incidence of late and early complications is statistically higher in hospitalized patients than at home. CONCLUSION: We think that a correct management of PEG (nurses correct information) and the experience of endoscopist and a dietician can significantly reduce the rate of complications.

[Longo hemorrhoidopexy vs Milligan-Morgan hemorrhoidectomy: perspective analysis]. / Emorroidopessi secondo Longo versus emorroidectomia secondo Milligan-Morgan: analisi prospettica.

The authors analyzed their experience from January 2001 to February 2005 on 117 patients treated with Longo hemorrhoidopexy (46 cases) and Milligan-Morgan hemorroidectomy (71 cases). All the patients were observed after a week and one month after surgical procedure; at 6 months the Authors controlled 70 patients treated with Milligan-Morgan and 33 treated with Longo technique. The pain after 24 hours was the same in two groups but after a week a significative difference between two groups (p<0.05) was registered with a better quality of life for hemorrhoidopexy group. At 6 months pain during defecation was present in two cases of Longo group and in 6 cases of Milligan-Morgan group. In author's experience the Longo technique is a safe treatment with lower postsurgical pain and lower complications.

Prenatal binge-like alcohol exposure alters brain and systemic responses to reach sodium and water balance.

The aim of the present work is to analyze how prenatal binge-like ethanol exposure to a moderate dose (2.0 g/kg; group Pre-EtOH) during gestational days (GD) 17-20 affects hydroelectrolyte regulatory responses. This type of exposure has been observed to increase ethanol consumption during adolescence (postnatal day 30-32). In this study we analyzed basal brain neural activity and basal-induced sodium appetite (SA) and renal response stimulated by sodium depletion (SD) as well as voluntary ethanol consumption as a function of vehicle or ethanol during late pregnancy. In adolescent offspring, SD was induced by furosemide and a low-sodium diet treatment (FURO+LSD). Other animals were analyzed in terms of immunohistochemical detection of Fra-like (Fra-LI-ir) protein and serotonin (5HT) and/or vasopressin (AVP). The Pre-EtOH group exhibited heightened voluntary ethanol intake and a reduction in sodium and water intake induced by SD relative to controls. Basal Na and K concentrations in urine were also reduced in Pre-EtOH animals while the induced renal response after FURO treatment was similar across prenatal treatments. However, the correlation between urine volume and water intake induced by FURO significantly varied across these treatments. At the brain level of analysis, the number of basal Fra-LI-ir was significantly increased in AVP magnocellular neurons of the paraventricular nucleus (PVN) and in 5HT neurons in the dorsal raphe nucleus (DRN) in Pre-EtOH pups. In the experimental group, we also observed a significant increase in Fra-LI along the nucleus of the solitary tract (NTS) and in the central extended amygdala nuclei. In summary, moderate Pre-EtOH exposure produces long-lasting changes in brain organization, affecting basal activity of central extended amygdala nuclei, AVP neurons and the inhibitory areas of SA such as the NTS and the 5HT-DRN. These changes possibly modulate the above described variations in basal-induced drinking behaviors and renal regulatory responses.

Ventilation and entrainment of breathing during cycling and running in triathletes.

PURPOSE: To assess whether entrainment of breathing (E) during exercise: 1) differed according to the test protocol in well-trained triathletes, and 2) improved ventilatory efficiency during exercise. METHODS: Eight triathletes performed three incremental tests until exhaustion: while cycling (CE), while running at increasing grade and constant speed (increasing GRADE) and while running at increasing speed and constant grade (increasing SPEED), respectively. E was evaluated as the percentage of breaths occurring at respiratory rates (F) corresponding to integer ratios of the exercise cycle rate. To assess whether E improved ventilatory efficiency, deltaVE/VO2 between nonentrained and entrained breaths was measured at each load. RESULTS: Mean E was higher in CE (57.2+/-21.9%) than in increasing GRADE (46.9+/-18.7%) and increasing SPEED (41.4+/-17.2%). E decreased at high loads in CE and increasing SPEED but not in increasing GRADE. In the group of subjects, E correlated with the degree of fitness (evaluated as VO2Tvent/VO2peak%) only during increasing GRADE. By multiple regression analysis on all data, minute ventilation correlated with CO2 production but not with the exercise cycle rate; however, either F or tidal volume correlated significantly with both these variables. VE/VO2 was lower in entrained than nonentrained breaths at each load in CE and increasing GRADE experiments, but the difference was small. CONCLUSIONS: In spite of some differences among protocols, triathletes showed significant E during incremental exercise tests. Spontaneous E appeared to slightly improve ventilatory efficiency during CE and increasing GRADE protocols.

The size of pancreatic pseudocyst does not influence the outcome of invasive treatments.

BACKGROUND: Authors generally agree that Giant Pancreatic Pseudocysts (> 10 cm) have a lower spontaneous resolution and are more difficult to treat than smaller pancreatic pseudocysts. This study was carried out on two groups of patients with larger and smaller pancreatic pseudocysts (pancreatic pseudocysts > 10 cm versus pancreatic pseudocysts < 10 cm), and aims to establish whether the size of pancreatic pseudocysts is a factor influencing treatment outcomes. PATIENTS AND METHODS: In a retrospective study, we examined 71 patients with pancreatic pseudocysts following an episode of acute pancreatitis, which were treated in our hospital from 1980 to 2000. Forty-one (57.5%) patients had a large pancreatic pseudocyst. Most patients underwent invasive treatments: 9 (12.6%) had percutaneous drainage, 37 (52.1%) open surgery and 13 (18.3%) endoscopic cyst gastrostomy. 12 patients (16.9%) of the 71 were cured with medical therapy alone. RESULTS: As far as the aetiology of the pancreatitis, location and number of the cysts were concerned, no major differences emerged between the two groups, although large pancreatic pseudocysts followed more severe pancreatitis (P = 0.0005). All giant pancreatic pseudocysts required invasive treatments; 40% of the pancreatic pseudocysts < 10 cm were successfully treated with medical therapy alone. No statistical differences were found regarding hospital mortality, morbidity, recurrence rate and hospital stay among the patients treated invasively. CONCLUSIONS: Giant pancreatic pseudocysts more often require invasive therapy due to persistent symptoms or complications. Treatment outcomes do not seem to be influenced by the size of the pancreatic pseudocysts.

Aortic graft in the jejunum without bleeding. A real surprise at endoscopy.

It is known that prosthetic infection, graft-duodenal fistula, and erosion are possible late complications after aortic reconstruction, and that all these reported complications are accompanied generally by variable bleeding with different presentations. We report the case of a 63-year-old man who underwent a diagnostic upper gastrointestinal endoscopy for investigation of nausea, anorexia, asthenia, fever, and mild leukocytosis. The patient's medical history included a gastric resection for ulcer, with Billroth II gastrojejunostomy reconstruction and implantation of a Dacron vascular graft for abdominal aortic aneurysm 20 years and 3 years earlier, respectively. Abdomen ultrasonography showed hypoechoic area around an aortic prosthesis. Endoscopy found a foreign body corresponding to the vascular graft at the jejunum. No signs of bleeding were recorded. The patient was hospitalized and submitted to surgery that involved extra-anatomic axillofemoral bypass, bowel resection with a gastrojejunum Roux anastomosis, and prosthesis removal.

Evaporation of solvent in one-bottle adhesives.

OBJECTIVE: To compare the evaporation of vehicles included in different single-bottle adhesives as a function of time. METHODS: The following adhesives were used: Prime and Bond 2.1 (Dentsply); Single Bond (3M); PrimaBond 97' (BJM); Syntac Sprint (Vivadent); Optibond Solo (Kerr) and Syntac Single Component (Vivadent). Two primers that are used in multiple-component adhesives (PermaQuick Primer, Ultradent and Scotchbond Multipurpose Primer, 3M) as well as distilled water, 96% ethanol and acetone were also included in the experiment. Samples of these products were stored in small glass containers under controlled temperature and humidity conditions. Initials mass and mass after different periods of time were registered to calculate the percentage loss of mass. RESULTS: The analysis of variance of the results followed by orthogonal contrast comparisons revealed a significantly higher loss of mass in the single-bottle adhesives that contain organic vehicles (especially in those in which the vehicle was acetone). A somewhat lower loss of mass was found in a water-based product. CONCLUSION: There is a relationship among the evaporation possibilities of the vehicles used in single-bottle adhesive systems and their loss of mass during storage.

Ultrastructural damage of the pulmonary endothelial cell after storage in lung preservation solutions. Comparison between Belzer and Euro-Collins solutions.

UNLABELLED: The preservation of the lung for transplantation for a long period is still a problem not solved. Euro-Collins (EC) and Belzer (UW) solution are the most widely used. The aim of this work is to analyse the direct influence of both EC and UW solutions on endothelial cells of human pulmonary artery by means of an ultrastructural analysis. The arteries were obtained from 3 patients that underwent pneumonectomy and prepared with the no touch technique. The arteries were divided in 15 specimens and preserved in EC and UW solution at 4 degrees C for 6 and 10 hours. The specimens were fixed in osmic acid veronal buffer 1% and embedded in Durcupan. Ultrastructural examination was done with transmission electron microscopy (TEM) and the influence of the solutions was evaluated using a grading scale with scores ranging from 0 to 4 that express the damages of the cellular wall, mitochondria and nuclei. The data are expressed as mean +/- standard deviation (n = 5). Student's t-test was used for statistical comparison between the solutions. RESULTS: after 6 hours of preservation in EC and UW the scores were 5.2 +/- 0.45 and 4.8 +/- 0.84 (p = 0.373) while after 10 hours were respectively 8.2 +/- 0.84 and 6.8 +/- 0.84 (p = 0.029). In conclusion our experimental model suggests that there are no significant differences between EC and UW after hypothermic 6 hours preservation while endothelial cells are better preserved after 10 hours in UW solution.

Pulmonary endothelial cell modifications after storage in solid-organ preservation solutions.

During lung preservation, the vascular endothelium is probably the first site of damage and these lesions are considered the main limiting factor in solid-organ preservation. In the present study, the ultrastructural changes in the endothelial cells of human pulmonary artery hypothermically stored (at 4 degrees C) for 6 and 12 h in Euro-Collins, University of Wisconsin and Ringer-lactate solutions were compared. The arteries obtained from three patients who underwent pneumonectomy were divided into 20 segments and preserved in the three solutions mentioned. The specimens, which were fixed in osmic acid, were examined using transmission electron microscopy. Transmission electron microscopy indicated that the cells stored in the University of Wisconsin solution either for 6 or 12 h were the best preserved, while the most severely damaged cells were those stored in Euro-Collins solution, even after just 6 h. The cells stored in Ringer-lactate showed an intermediate level of damage. The data from an ultrastructural grading scale, which quantified the damage to the cytoplasm, mitochondria and nucleus, were in broad agreement with the general transmission electron microscopy observations. Analysis of variance of the grading scale data showed that there were statistically significant differences between the groups after both 6 and 12 h storage (P < 0.05).

Barcoll hardness of resin-modified glass-ionomer cements and a compomer.

The objective of this study was to evaluate the influence of several factors on the hardness of resin-modified glass-ionomer cements (hybrid ionomers) and polyacid-modified resin composites (compomers). Disk-shaped specimens were prepared from the following materials: Vitremer, Fuji II LC, Photac-Fil, and Dyract. Three specimens of each product were irradiated with a light-curing device and three were not. Barcoll hardness was determined on both sides of the specimen 10 minutes after irradiation and after 48 hours of immersion in 37 degrees C water. A factorial design was used to evaluate the factors that influenced the results. The Dyract group that was not light cured was not included in the analysis because the product did not harden under this circumstance. Analysis of variance revealed a significant effect of material, time, and specimen side when light curing was carried out. The use or nonuse of light curing was also significant. For some hybrid ionomers (e.g., Photac-Fil), light curing is a more essential step than for others to obtain adequate hardness values.