Effect of Simulated Annual At-home Bleaching on Susceptibility to Staining, Translucency, and Whiteness Variations of Computer-aided Design and Computer-aided Manufacturing Monolithic Materials

The effect of annual at-home bleaching on the color, translucency, and whiteness properties of computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic materials requires investigation. The aim of the present in vitro study was to evaluate the effect of simulated annual at-home bleaching (consisting of daily applications for 10 hours a day for 14 days), for up to 3 years, on susceptibility to staining (ΔE00), translucency (ΔTP00), and whiteness (ΔWID) variations and on topography of CAD-CAM monolithic materials. Disks from the Lava Ultimate (LU), Vita Enamic (VE), IPS Empress CAD (EMP), and IPS e.max CAD (EMAX) were allocated as follows: 1) nonbleached or 2) bleached with 10% carbamide peroxide. After reading the CIE L*a*b* coordinates at baseline (R0), specimens were bleached or not and subsequently immersed for a 1-year simulated period in coffee before the next reading (R1). This process was repeated two more times, resulting in R2 and R3. The ΔE00, ΔTP00, and ΔWID between R1, R2, and R3 in relation to R0 were calculated. The surface topography was analyzed by scanning electron microscopy. In general, bleaching increased the staining susceptibility of all materials when compared to the nonbleached groups and that of the LU, VE, and EMAX over the years. Bleaching decreased the translucency of the VE in all years and over the years. When compared to the nonbleached groups, bleaching decreased the whiteness of the LU and EMAX and increased the whiteness of the EMP, while the VE was not affected. In the LU, the whiteness decreased over the years in both treatments, whereas the other materials were not affected with time. All materials showed progressive topographic changes over the years. The simulated annual at-home bleaching with 10% carbamide peroxide adversely affected the topography and the optical and/or colorimetric properties of the evaluated materials.

Effect of In-office Bleaching on Color, Translucency, and Whiteness Variations in CAD-CAM Monolithic Materials

Little is known about the impact of bleaching on the optical properties of computer-aided design and computer-aided manufactured (CAD-CAM) monolithic materials. The aim of the present study was to evaluate the effect of one session of in-office bleaching on stain removal, staining susceptibility, translucency, and whiteness variations of CAD-CAM monolithic materials. Disks were fabricated from Lava Ultimate (LU), Vita Enamic (VE), Vita Suprinity (VS), and IPS e.max CAD (IPS). A spectrophotometer was used to register Commission Internationale de l'Eclairage L*a*b* coordinates. For stain removal, 80 specimens from each material were assessed at baseline (R0) and after immersion in deionized water or coffee for 36.5 days followed or not by bleaching with 40% hydrogen peroxide (R1). For staining susceptibility, 80 specimens from each material were analyzed at baseline (R0'), and after having been bleached or not and immersed in deionized water or coffee (R1'). Both analyses were calculated as the color difference (ΔE00) between R1-R0 and R1'-R0', respectively. Differences in translucency (ΔTP00) and whiteness (ΔWID) between R1-R0 and R1'-R0' were also calculated. Data were analyzed by three-way ANOVA and the Games-Howell post hoc test (α=0.05). Clinical significance was based on 50%:50% perceptibility and acceptability thresholds for ΔE00, ΔTP00 and ΔWID, respectively. Surfaces were analyzed by scanning electron microscopy. Coffee increased ΔE00 in LU, VE, and VS, and decreased their translucency and whiteness, whereas the IPS had only its whiteness affected. Bleaching after immersion in coffee decreased ΔE00 in LU and VE, and increased translucency and whiteness of LU, VE, and VS. No effect was observed on IPS. Bleaching before immersion in coffee decreased translucency of LU, but within the acceptable interval, while VE exhibited lower ΔE00, and became more translucent and less dark. Both VS and IPS were not affected. One session of in-office bleaching benefited optical properties of the previously stained LU, VE, and VS, without increasing their susceptibility to staining or adversely providing clinically unacceptable variations in their translucency and whiteness. All variations exhibited by the IPS were below the perceptible threshold.

Clonal spread of carbapenem-resistant Acinetobacter baumannii in a neonatal intensive care unit

Acinetobacter baumannii has often been associated with colonization and/or infection in neonatal intensive care units (NICU). This study describes a clonal spread of carbapenem-resistant A. baumannii (CRAB) isolates in an NICU. In total, 21 CRAB isolates were collected from premature newborns. Only polymyxin B was active against such isolates. Nineteen CRAB isolates were clonally related (Cluster C, which belonged to worldwide-disseminated ST1). All newborns had peripheral access and had received β-lactam therapy previously. The implementation of strict infection control measures was of fundamental importance to eradicate the clonal type in the study hospital.

Effects of gamma radiation on raspberries: safety and quality issues

There is an ever-increasing global demand from consumers for high-quality foods with major emphasis placed on quality and safety attributes. One of the main demands that consumers display is for minimally processed, high-nutrition/low-energy natural foods with no or minimal chemical preservatives. The nutritional value of raspberry fruit is widely recognized. In particular, red raspberries are known to demonstrate a strong antioxidant capacity that might prove beneficial to human health by preventing free radical-induced oxidative stress. However, food products that are consumed raw, are increasingly being recognized as important vehicles for transmission of human pathogens. Food irradiation is one of the few technologies that address both food quality and safety by virtue of its ability to control spoilage and foodborne pathogenic microorganisms without significantly affecting sensory or other organoleptic attributes of the food. Food irradiation is well established as a physical, nonthermal treatment (cold pasteurization) that processes foods at or nearly at ambient temperature in the final packaging, reducing the possibility of cross contamination until the food is actually used by the consumer. The aim of this study was to evaluate effects of gamma radiation on raspberries in order to assess consequences of irradiation. Freshly packed raspberries (Rubus idaeus L.) were irradiated in a (60)Co source at several doses (0.5, 1, or 1.5 kGy). Bioburden, total phenolic content, antioxidant activity, physicochemical properties such as texture, color, pH, soluble solids content, and acidity, and sensorial parameters were assessed before and after irradiation and during storage time up to 14 d at 4°C. Characterization of raspberries microbiota showed an average bioburden value of 10(4) colony-forming units (CFU)/g and a diverse microbial population predominantly composed of two morphological types (gram-negative, oxidase-negative rods, 35%, and filamentous fungi, 41%). The inactivation studies on the raspberries mesophilic population indicated a one log reduction of microbial load (95% inactivation efficiency for 1.5 kGy), in the surviving population mainly constituted by filamentous fungi (79-98%). The total phenolic content of raspberries indicated an increase with radiation doses and a decrease with storage time. The same trend was found for raspberries' antioxidant capacity with storage time. Regarding raspberries physicochemical properties, irradiation induced a significant decrease in firmness compared with nonirradiated fruit. However, nonirradiated and irradiated fruit presented similar physicochemical and sensory properties during storage time. Further studies are needed to elucidate the benefits of irradiation as a raspberries treatment process.

Central administration of mCPP, a serotonin 5-HT(2B/2C) agonist, decreases water intake in rats

In the present study, we investigated in rats the effect of third ventricle injections of 1-(3-chlorophenyl)piperazine (mCPP), a 5-HT(2) receptor agonist, on water intake induced by three different physiological stimuli: fluid deprivation, acute salt load and hypovolemia. Injections of mCPP in the doses of 80 and 160 nmol/rat were able to decrease water intake in all three conditions studied. Third ventricle injections of mCPP (160 nmol/rat) were no longer able to diminish water intake in the groups of rats pretreated with central injections of an equimolar amount of (+)-cis-4,5,7a,8,9,10,11,11a-octahydro-7H-10-methylindolo[1,7-bc][2,6]-naphthyridine (SDZ SER 082), a selective 5-HT(2B/2C) antagonist. The central administration of mCPP (160 nmol/rat) was not able to modify the intake of a 0.1% saccharin solution. It is suggested that the central activation of a 5-HT(2B/2C) component is able to impair the drive for water intake induced by the physiological stimuli represented by fluid deprivation, acute salt load and hypovolemia. This effect seems not to be consequent on a general nonspecific central nervous system depression or on a locomotor deficit, because saccharin intake is not affected by third ventricle injections of mCPP.

Effects of fluorescent light and vacuum packaging on the rate of decomposition of pigments in paprika (Capsicum annuum) powder determined by reversed-phase high-performance liquid chromatography

The effect of storage time, the presence of light and oxygen on the decomposition rate of carotenoid pigments in paprika (Capsicum annuum) powders was determined by reversed-phase high-performance liquid chromatography (RP-HPLC). The similarities and dissimilarities of pigment composition of samples under various storage conditions was elucidated by principal component analysis (PCA) and stepwise regression analysis (SRA). Calculations proved that the overall decomposition rate of pigment sections equally depended on the storage time and on the presence of light and oxygen, the effect of storage time being the most decisive factor while the impact of oxygen was the lowest. The selectivity of decomposition also depended on the storage time and on the presence of oxygen the influence of storage time being the most important. RP-HPLC followed by PCA and SRA can be successfully used for the study of the impact of environmental conditions on the decomposition of carotenoid pigments of paprika powders.

Profiling of colour pigments of chili powders of different origin by high-performance liquid chromatography

The colour pigments of five chili powders of different origins were separated and quantified by reversed-phase high-performance liquid chromatography (RP-HPLC). The similarities and dissimilarities of pigment composition of chili powders were elucidated by principal component analysis (PCA). RP-HPLC separated 50-100 pigment fractions depending on the detection wavelength and on the origin of chili powder. It was found that the pigment composition of chili powders from Malaysia and China and from India and Pakistan show marked similarities while the composition of colour pigments of chili powder from Thailand was different. It was further established that the chromatograms are similar in the first 5-35 min of development, they are highly different between 35 and 75 min and moderately different at the end of the chromatograms. It was concluded that RP-HPLC followed by PCA can be successfully used for the identification of chili powders according to the composition of their colour pigments.

Evidence of a high frequency of HIV-1 subtype F infections in a heterosexual population in Buenos Aires, Argentina

We analyzed HIV-1 genetic variability, phylogenetic relationships, and association with transmission modes among 58 HIV-1-infected patients from Buenos Aires City, Argentina. The 58 strains were classified as env(gp41) HIV-1 group M subtype B (n = 34) and subgroup F1 of subtype F (n = 24). Potential recombinants combining parts of viral regions from different subtypes, B(prot)/F(env) and F(prot)/B(env), were found in two patients, and a dual infection with HIV-1 prot subtypes B and F was identified in one individual. Epidemiologic analysis of behavioral risks revealed that the frequency of infection with subtype F viruses was significantly higher (p < 0.0001) among heterosexual patients (71%) compared with homosexual patients (11%). The spread of non-B subtypes into heterosexual populations may be more common than previously thought. Our findings provide important information for monitoring the transmission of HIV-1 strains among different risk groups in Argentina as well as for vaccine development.

The treatment of portal hypertension by videolaparoscopy in situs inversus totalis

A rare case of a 32-year-old male with situs inversus totalis viscerum admitted to hospital for hematemesis owing to portal hypertension of Laennec cirrhosis was treated for the first time by videolaparoscopic surgery. Situs inversus diagnosis was confirmed by thoracic radiography, electrocardiogram, echocardiogram, abdominal echography and computed tomography. Upper gastrointestinal endoscopy showed esophageal varices and large varices in the fundus of the stomach. A successful operation (azygo-portal disconnection, splenic artery ligation without splenectomy; transesophageal suturing of esophageal varices without opening the esophagus and cholecystectomy), was performed by videolaparoscopy. The uneventful postoperative evolution (4-day hospitalization) reinforces the viability of the videolaparoscopic approach and the possibility of the application of this procedure even to situs inversus totalis organorum.

Leishmanicidal activity of combretastatin analogues and heteroanalogues

We have investigated the in vitro leishmanicidal activity of representative members from series II-V of combretastatin analogues and heteroanalogues. Most of them exhibited different degrees of activity against various strains of Leishmania spp. The diaryl(heteroaryl)ethane system or the more complex fused heterocyclic stilbenoids, constitute useful skeletal bases to support some kind of antiparasitic activity. Particularly, the incorporation of 2-furyl substituents led to potent antileishmanial compounds, which have been selected for in vivo testing on murine models.

Synthesis and pharmacological activity of diarylindole derivatives. Cytotoxic agents based on combretastatins

Taking into account the structure of Combretastatins, we have synthesized and assayed for cytotoxic activity of new indole derivatives. Two aryl groups are maintained in the cis orientation required for activity by means of an indole moiety built up on less active ketoderivatives used as starting materials.

Predominance of human immunodeficiency virus type 2 subtype B in Abidjan, Ivory Coast

We analyzed the genetic variability and phylogenetic relationships among 28 HIV-2 strains collected from patients enrolled in an HIV epidemiologic study in Abidjan, Ivory Coast, during 1995-1996. Although both subtype A (n = 8; 29%) and subtype B (n = 20; 71%) were present in this sampling, the majority of infections were caused by subtype B viruses. These findings contrasted with the reported predominance of HIV-2 subtype A in other African countries. The broad genetic diversity identified among protease gene sequences for HIV-2 subtype A (6%; range 3-15%) and subtype B (7%; range, 2-12%), and their presence in Abidjan during the 1980s, document a long coexistence of two viral subtypes in Ivory Coast. Our data indicate that viruses of subtypes A and B have contributed to the HIV-2 epidemic in Ivory Coast.

Laparoscopic cholecystectomy in children and adolescents

During the period between August 1991 and November 1995, seven patients under age 17 were submitted to videolaparoscopic cholecystectomy (LC). Two were males and five females with ages ranging from 12 to 16 years (mean 13.8 years). The diagnosis of chronic cholecystitis with gallstones was made by the clinical history and physical and ultrasonographic examinations. There was no evidence of an association with hemolytic diseases, familial hyperlipidemia or Glucose-6-phosphate dehydrogenase (G6PD) deficiency. The surgery was performed under general anesthesia and the abdomen approached by four ports: a 10 mm umbilical incision, a 5 mm cystic, a 5 mm one at the xiphoid appendix and a 10 mm one at the left lateral margin of the left rectus abdominal muscle between the umbilical scar and the xiphoid appendix. Operative time averaged 120 minutes (105-150 min). One case required conversion to laparotomic approach because of Mirizzi's Syndrome, which was diagnosed by intraoperative cholangiography performed in all cases. There were no deaths or major postoperative complications. Hospital stays ranged from 1-3 days in the six patients submitted to LC. Thus LC in children can be considered a good method, requiring only more care regarding the use of proper equipment, complete and careful dissection of the biliary hilus, and intraoperative cholangiography. The latter is indispensable, as these children can present a higher rate of anatomic anomalies. The advantages of this techniques include a less painful postoperative period with a faster recovery, and it is especially recommended in children, who are less tolerant to physical restriction and pain than adults.

Hemobilia as a complication of laparoscopic cholecystectomy

Laparoscopic surgery, mainly laparoscopic cholecystectomy, is a recently developed surgical procedure that has rapidly gained acceptance. Its complications remain to be critically analyzed. In this initial series of 69 patients, the rate of complications was 4.3%, and the conversion to open rate was 8.7%. A late complication occurring 4 months after surgery is presented. Upper gastrointestinal bleeding from hemobilia resulted from a cystic artery aneurysm communication with the cystic duct. This study stresses the importance of careful management of biliary structures to avoid the possibility of late and severe complications that can result from using this new surgical procedure.

Carnitine supplementation in diphtheria

We studied the effect of carnitine supplementation in patients with diphtheria. Six hundred and twenty five children of diphtheria received either DL-carnitine (100 mg/kg/day in two divided doses orally for four days), or no carnitine, in addition to the routine treatment for diphtheria. The patients receiving carnitine (n = 327) and controls (n = 298) were matched for age, sex, duration of symptoms, grade of toxemia and immunization status. Patients receiving carnitine showed a significant reduction in incidence of myocarditis as compared to controls (p = 0.001). Cases with myocarditis receiving carnitine therapy showed a significant reduction in mortality as compared to controls (p < 0.001). In view of a significant decline in incidence and mortality of myocarditis in cases of diphtheria, we recommended that all cases with diphtheria should receive carnitine supplementation.

Tolerance of preschoolers to two dosage strengths of vitamin A preparation

The tolerance to two alternative large-dosage strengths of vitamin A preparation was determined in a double-blind study involving 2471 children in two municipalities in the Philippines. Each child, aged 1-6 y, not suffering from active xerophthalmia or from nausea and/or vomiting, headache, diarrhea, and fever, was randomly given 1 mL of a syrupy suspension later identified to contain 0, 60, or 30 mg vitamin A. Clinical evaluation of subjects was done by physicians 24 h and 1 wk after dosing. Nausea and/or vomiting and headache were twice as common among children given 60 mg than those given 30 mg. Severe vomiting (1.2%) was confined to those given 60 mg. Almost all experienced their symptoms within 24 h after dosing; symptoms lasted for no more than 12-24 h. The incidence of diarrhea and fever for vitamin A recipients was not significantly different from that of those receiving placebo.

The protective effect of carnitine in human diphtheric myocarditis

Carnitine, an important cofactor in the transport of fatty acids to the interior of cell mitochondria, is depleted in myocardial tissue of guinea pigs submitted to diphtheric toxin administration. Mortality rates were reduced in these animals by supplying exogenous amounts of carnitine. The accumulation of fatty acids in the cytoplasm of human heart cells reported in cases of diphtheria suggests that carnitine might possibly be depleted in human myocardium as well. For the purpose of studying the effect of carnitine administration, 132 diphtheric patients were randomly divided into two groups, one of them (carnitine-treated group, n = 73) receiving DL-carnitine, 100 mg/kg/day during 4 days after admission, in addition to routine treatment, which was prescribed for this and the control group (n = 59). The presence of myocardial damage was evaluated by clinical, electrocardiographic, radiological, and enzymatic criteria. Carnitine administration resulted in decreased incidence of heart failure (P = 0.0475), of pacemaker implants (P = 0.0256), and of lethality indexes due to myocarditis (P = 0.013). We suggest that carnitine can play an important role in the treatment of diphtheric patients.