Effect of Additional Apical Preparation on Retreatment of Curved Root Canals Filled with Different Sealers

OBJECTIVE

 This study assessed the influence of additional apical preparation on material removal during retreatment of curved root canals filled with different sealers.

MATERIALS AND METHODS

 Twelve mesial roots of mandibular molars with two separate canals and curvature between 25 and 35 degrees were selected. The working length was established 1-mm short of the apical foramen, and all the root canals were prepared using ProDesign R (PDR) 25/0.06. After preparation, the root canals were divided in two groups (n = 12) and filled by continuous wave condensation technique with NeoMTA Plus or AH Plus. All the root canals were retreated using rotary ProDesign Logic RT 25/0.08, reciprocating PDR 25/0.06 and apical preparation with PDR 35/0.05. Additional apical preparation was performed with ProDesign Logic (PDL) 50/0.01. The samples were scanned using a Skycan 1176 micro-computed tomography (micro-CT), voxel size 8.74 µm, before and after the retreatment procedures. Percentages of remaining filling material were evaluated.

STATISTICAL ANALYSIS

 The data were submitted to paired and unpaired t-tests (α = 0.05).

RESULTS

 Percentage of remaining filling material was similar between the root canals filled with NeoMTA Plus or AH Plus sealer after retreatment using PDR 35/0.05, and after additional apical preparation using PDL 50/0.01 (p > 0.05). However, PDL 50/0.01 significantly decreased the percentage of remaining filling material in the apical third after the additional apical preparation for both sealers (p < 0.05).

CONCLUSION

 NeoMTA Plus or AH Plus did not influence the retreatment of curved root canals. ProDesign Logic 50/0.01 promoted greater filling material removal in the apical third.

Chyloperitoneum due to gastric carcinoma: a case report

Chyloperitoneum is a rare manifestation of gastric carcinoma, generally occurring late in the course of the disease with a poor prognosis. We report an unusual case of chyloperitoneum in a patient with gastric carcinoma. A 61-year-old male patient presented with postprandial fullness, nausea and weight loss. The upper gastrointestinal endoscopy demonstrated a stenosing lesion of the esophagogastric junction. A biopsy was made and revealed a signet-ring cell gastric adenocarcinoma. The staging CT scan showed multiple abdominal lymphadenopathies and mild ascites. The patient underwent a staging laparoscopy that revealed a large carcinoma of the gastric cardia and a milky-appearing peritoneal fluid. A peritoneal washing and abdominal drainage were performed. The fluid analysis showed a high concentration of triglycerides, compatible with a chyloperitoneum. The patient started medium chain triglycerides-based diet with good response. This case report emphasizes that chyloperitoneum should be considered when assessing patients with gastric carcinoma.

Effect of the inoculation of sugarcane silage with Lactobacillus hilgardii and Lactobacillus buchneri on feeding behavior and milk yield of dairy cows

Despite its low NDF digestibility, sugarcane is an option for feeding dairy cattle in tropical regions. We evaluated the effect of sugarcane silages inoculated with CCMA 0170 (LH; an epiphytic bacteria isolated from sugarcane) or with NCIMB 40788 (LB; a commercial strain isolated from temperate grasses) on dairy cow performance and feeding behavior. The microbial inoculums were previously grown in the laboratory to obtain 5 log cfu/g of fresh forage. Nine tons of each inoculated silage and a noninoculated control silage (CON) were harvested from the same field and stored for at least 35 d in experimental 20 × 2.1 × 0.4 m bunker silos. Fifteen Holstein cows in late lactation (336 ± 175 days in milk at the start of the experiment) received the treatments in five 3 × 3 Latin squares with 21-d periods. The diets contained 20% of DM of sugarcane silage and 41% of DM of corn silage. Milk yield was increased from 18.0 kg/d for CON to18.8 kg/d for LH, but LB did not elicit a detectable increase in milk yield (18.1 kg/d). The daily yields of fat, protein, lactose, and total solids were increased by LH. Daily DMI and total tract apparent digestibility of nutrients did not differ among treatments. Both inoculated silages reduced acetate and increased butyrate proportions in ruminal VFA, but only LH silage reduced the acetate to propionate ratio (3.0 vs 3.3). First meal duration was shorter for CON compared to LH and LB. The proportion of daily intake between 0700 and 1300 h tended to be increased, and the proportion between 1900 and 0700 h was reduced by LH. The inoculation of sugarcane silage with affected rumen fermentation profile and feeding behavior of late lactation dairy cows, increasing the yield of milk solids.

The myostimulating effect of tissue kallikrein on rat uterus

The mechanism of the myostimulating activity of rat tissue kallikrein on rat uterus was re-examined using uterus from kininogen-deficient rats and HOE 140 (D-Arg[Hyp3, Thi5, D-Tic7, Oic8]bradykinin), a specific bradykinin receptor-B2 antagonist. The uterus from kininogen-deficient rats was 50 times less sensitive to rat kallikrein than that from normal rats. HOE 140 (6 to 60 nM) inhibited the contracting effects of bradykinin and of rat kallikrein. Porcine kallikrein had no effect on rat uterus. Bradykinin and rat kallikrein induced a relaxation of rat duodenum. The duodenum from kininogen-deficient rats was 100 times less sensitive to rat kallikrein than the duodenum from normal rats. HOE 140 (0.6 to 3 nM) inhibited the relaxing effects of bradykinin and of kallikrein. Preincubation of rat kallikrein with aprotinin (Trasylol) abolished the effects of kallikrein on smooth muscles. HOE 140 inhibited the amidolytic activity of tissue kallikrein with a Ki value of 220 microM. HOE 140, at micromolar concentrations, suppressed the kininogenase activity of tissue kallikrein. Plasma of deficient rats contained 0.7% of the normal levels of kininogens. After washing the blood vessels with saline, kininogens were present in uterine homogenates but not in duodenal homogenates from both rat strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Cannabinoid receptor binding and agonist activity of amides and esters of arachidonic acid

The cannabinoid receptor in brain (CB1) specifically binds delta 9-tetrahydrocannabinol, the predominant central nervous system-active component of marijuana. An eicosanoid found in brain, N-(2-hydroxyethyl)arachidonylamide (anandamide), binds to CB1 with similar affinity. This report considers structure-activity requirements for a series of novel amides and rigid hairpin conformations typified by N-(2-hydroxyethyl)prostaglandin amides, assayed with phenylmethylsulfonyl fluoride inactivation of esterases/amidases. Arachidonyl esters were 30-fold less potent than N-(2-hydroxyethyl)arachidonylamide, showing a rank order of potency of methyl = ethyl > propyl = isopropyl. Within the N-(hydroxyalkyl)arachidonylamide series, a one-carbon increase in chain length increased the potency 2-fold, but continued extension decreased affinity. Substituting the amide for the N-(2-hydroxyethyl)amide function produced a 4-fold loss of affinity. The N-(propyl)-, N-(butyl)-, and N-(benzyl)arachidonylamide derivatives exhibited a 3-fold increase, no change, and a 5-fold decrease, respectively, in affinity, compared with N-(2-hydroxyethyl)arachidonylamide. Both the methoxy ether and the formamide derivatives suffered > 20-fold loss of potency, compared with N-(2-hydroxyethyl)arachidonylamide. N-(2-Aminoethyl)arachidonylamide interacted poorly with CB1. At 100 microM, N-(2-hydroxyethyl)amide analogs of prostaglandin E2, A2, B2, and B1 failed to alter [3H]CP55940 binding to CB1. N-(2-Hydroxyethyl)arachidonylamide inhibited adenylate cyclase with lesser potency but with similar efficacy, compared with desacetyllevonantradol. Extending the length of the hydroxyalkyl moiety by one carbon increased the apparent potency by 1 order of magnitude. The N-(propyl) derivative exhibited a 5-fold greater potency than did the N-(2-hydroxyethyl) analog. It appears that the bulk and length of the moiety appended to arachidonic acid are more important determinants of affinity for CB1 than is hydrogen-bonding capability.

Trypanosoma rangeli (Tejera, 1920) isolated from a sylvatic rodent (Echimys dasythrix) in Santa Catarina Island, Santa Catarina State: first report of this trypanosome in southern Brazil

A trypanosome strain isolated from a sylvatic rodent (Echimys dasythrix) from Santa Catarina Island (Santa Catarina State, Brazil) was characterized by the following methods: experimental transmission and development in invertebrate and vertebrate hosts, morphometry, cross protection, complement sensitivity, lectin agglutination and isoenzyme profiles. Comparisons were made with standard Trypanosoma cruzi and T. rangeli strains. All methods except isoenzyme analysis led to the identification of the isolate as T. rangeli. The isoenzyme differences found could be explained on the basis of polymorphism. Therefore this is the first report of T. rangeli in southern Brazil, increasing the geographical distribution of this parasite.

[Cineventriculography with radionuclides and intravenous dipyridamole in the prognostic evaluation after acute myocardial infarction]

PURPOSE

To evaluate safety and usefulness of dipyridamole-radionuclide ventriculography (D-RVG), soon after acute myocardial infarction (MI), in the prediction of future cardiac events. Traditionally performed tests were also compared.

PATIENTS AND METHODS

Forty-one patients (4 females) with recent MI underwent rest and dipyridamole (0.58 mg/kg of body weight) radionuclide ventriculography. The criteria for a positive test for ischemia was failure to increase left ventricular ejection fraction in 0.05 from baseline value. All patients had also coronary angiography and 36 patients underwent thallium-201 scintigraphy for comparison. The mean follow-up was 16 +/- 3 months. The following findings were considered future for events: cardiac death, reinfarction, significant angina or heart failure.

RESULTS

During the follow-up 18 of the 20 patients who had cardiac events had shown positive dipyridamole-RVG, as opposed to 5 of 21 event-free patients (p less than 0.01). The ventriculographic criteria for a positive test and dipyridamole left ventricular ejection fraction were the strongest predictors of those medical events (p less than 0.01 and p less than 0.001). Among the 36 patients who had thallium-201 imaging, 16 subsequently had cardiac events and the scans were positive in 82% (p less than 0.01). Twelve (29%) patients experienced reactions during dipyridamole infusion although no fatal complications were noted.

CONCLUSION

Dipyridamole-RVG is relatively safe and a sensitive predictor of future cardiac events soon after acute MI, although additional experience is required before this new technique should be routinely recommended as an alternative approach.

The defect in pulmonary gas transfer in patients with sickle cell disease

Nine patients with sickle cell disease and without concomitant cardiopulmonary illness or acute problems were studied with lung function tests. Besides arterial hemoglobin unsaturation, found in all cases so studied, a slight decrease in PaO2 was also present. The pulmonary gas transfer defect was studied and found to be due mostly to increased right to left shunting, although uneven ventilation/perfusion relationships seem to have been a factor in a few cases. Our data clearly show that the diffusion was not implicated in the gas transfer defect. The clinical implications of this little studied and less mentioned respiratory defect are discussed. Since the defect may enhance the risk of sickling crises, it should be measured in each individual patient, for appropriate prophylactic measures. After accidents, pre and post-operatively and during acute respiratory illness, the defect should be again reevaluated. In all probability many patients will be discovered who represent a respiratory risk, and may require special immunizations, prophylactic antibiotics, professional relocation and, during emergencies, intensive respiratory care.