Nd:YAG laser influence on microleakage of class V composite restoration.

OBJECTIVE: The purpose of this research was to evaluate Nd:YAG laser influence on microleakage of class V composite restorations. BACKGROUND DATA: There are few studies concerning laser with restorative materials, considering microleakage. One more sent. METHODS: Thirty six cavities were prepared and divided into three groups (n = 12): group 1, control; group 2, Nd:YAG laser irradiation before adhesive technique; group 3, Nd:YAG laser irradiation after adhesive technique was used as the single bottle. Adhesive system Nd:YAG laser parameters were 320 microm of fiberoptic; energy/pulse of 40 mJ of energy/pulse; repetition rate of 15 Hz; power of 0.6 W; pulsed and non-contact, 1 mm from the surface; 30 seconds in scanning mode; energy density was 49.76 J/cm(2). Cavities were restored with microhybrid composite. After having used a polishing technique, thermocycling and impermeabilization procedures were performed and specimens were submitted to a microleakage test consisting of immersion in aqueous solution of 50% silver nitrate for 8 h, in the total absence of light. After washing and drying procedures, teeth were embedded to facilitate buccal-lingual vertical sectioning. Microleakage was revealed by light. RESULTS: We accomplished Kruskal-Wallis test at 5% level of confidence and observed no statistically significant difference between the tested groups. CONCLUSIONS: Based on the obtained results, it was possible to conclude that Nd:YAG laser in the parameters used, has no influence on marginal microleakage in composite restorations, independent of the moment the laser was used.

Nd:YAG laser influence on microleakage of class V composite restoration.

OBJECTIVE: The purpose of this research was to evaluate the influence of the Nd:YAG laser on microleakage of class V composite restorations. BACKGROUND DATA: There has been very little research that concerns microleakage resulting from the use of lasers and restorative materials. MATERIALS AND METHODS: Thirty-six cavities were prepared and divided into three groups (n = 12) as follows: Group 1, control; Group 2, Nd:YAG laser irradiation before adhesive technique; Group 3, Nd:YAG laser irradiation after adhesive technique. Nd:YAG laser parameters were 320 micro m of fiberoptics; energy/pulse of 40 mJ of energy/pulse; repetition rate of 15 Hz; power of 0.6 W; pulsed and non-contact, 1 mm from the surface; 30 sec in scanning mode; energy density was 49,76 J/cm(2). Cavities were restored with microhybrid composite. After polishing, thermocycling and impermeabilization procedures were performed and specimens were submitted to a microleakage test, with complete immersion in aqueous solution of 50% silver nitrate for 8 h, in the total absence of light. After washing and drying, teeth were embedded to facilitate buccal-lingual vertical sectioning. Microleakage was revealed by light. RESULTS: We used the Kruskal-Wallis test at a 5% level of confidence and observed no statistically significant difference among the tested groups. CONCLUSION: It was possible to conclude that Nd:YAG laser does not influence marginal microleakage on composite restorations, independent of the moment the laser had been used.

[In vitro antimicrobial susceptibility of Helicobacter pylori strains: isolation of strains resistant to clarithromycin]. / Susceptibilidad in vitro de cepas de Helicobacter pylori: aislamiento de cepas resistentes a claritromicina.

BACKGROUND: Our laboratory has carried out an epidemiological surveillance of Helicobacter pylori antimicrobial susceptibility since 1997. AIM: To report the antimicrobial susceptibility of H pylori strains, isolated in Chile from August 1997 to August 2000. MATERIAL AND METHODS: Ninety one H pylori strains, obtained from antral gastric biopsies during upper gastrointestinal endoscopies were studied. Susceptibility towards clarithromycin, amoxicillin, bismuth subcitrate and metronidazole was studied by an agar diffusion technique. RESULTS: All strains were susceptible to amoxicillin and two strains were resistant to clarithromycin. Forty two percent of strains were resistant to metronidazole and 13% were resistant to bismuth subcitrate. CONCLUSIONS: These results underscore the need to maintain an epidemiological surveillance of H pylori antimicrobial susceptibility, to modify its eradication therapy accordingly.

In vitro antibacterial activity of Chilean red wines against Helicobacter pylori.

The antibacterial activity of sixteen Chilean red wines (Cabernet Sauvignon, Cabernet Merlot, Cabernet Organic and Pinot Noir), and the active extracts of two randomly selected wines were assayed for their antibacterial activity on six strains of Helicobacter pylori isolated from gastric biopsies. The active fraction of the wines was obtained by dichloromethane extraction, and the antibacterial activity of the wines and extracts was evaluated by an agar diffusion method. All the red wines studied showed some antibacterial activity on the six strains of H. pylori, although the strains were heterogeneous in their susceptibility to each particular wine. The active fraction of the two wines selected also showed good activity against the strains tested. The main active compound was identified as resveratrol. The results presented indicate that Chilean red wines have antibacterial activity against H. pylori, which depends mainly on the presence of resveratrol.

[Helicobacter pylori: cagA analysis and vacA genotyping in Chile. Detection of a s2/m1 strain]. / Helicobacter pylori: análisis de cagA y genotipificación de vacA en Chile. Detección de una cepa s2/m1.

BACKGROUND: The genes cagA and vacA encode H pylori virulence factors. AIM: To genotype these genes in H pylori strains isolated from patients with upper gastrointestinal symptoms. MATERIAL AND METHODS: We studied 50 patients who underwent an upper gastrointestinal endoscopy, with positive culture for H pylori. Detection of cagA and vacA genotyping was done using polymerase chain reactions. RESULTS: The gene cagA was detected in 19 samples (38%). Signal sequences s1 and s2 of vacA gene were detected in 16 samples each (32%). There was simultaneous amplification of s1 and s2 in 6 samples and they were not detected in 9 samples. The middle region of vacA was m1 in 9 samples, m2 in 29 samples and there was simultaneous amplification of m1 and m2 in 12 samples. In 16 samples (32%), more than one type of signal sequence or medial region was detected. Of those patients in whom vacA was the only genotype detected, 15 were s2/m2, 7 were s1/m1, 4 were s1/m2 and 1 was s2/m1. CONCLUSIONS: In these patients, the infection with cagA- H pylori strains, predominates, the prevalence of infection with s1 or s2 strains is similar and the predominant medial region is m2.

Noninvasive cerebral blood volume measurement during seizures using multichannel near infrared spectroscopic topography.

Near infrared spectroscopic topography (NIRS) is widely recognized as a noninvasive method to measure the regional cerebral blood volume (rCBV) dynamics coupled with neuronal activities. We analyzed the rCBV change in the early phase of epileptic seizures in 12 consecutive patients with medically intractable epilepsy. Seizure was induced by bemegride injection. We used eight-channel NIRS in nine cases and 24 channel in three cases. In all of the cases, rCBV increased rapidly after the seizure onset on the focus side. The increased rCBV was observed for about 30-60 s. The NIRS method can be applied to monitor the rCBV change continuously during seizures. Therefore, this method may be combined with ictal SPECT as one of the most reliable noninvasive methods of focus diagnosis.

The pathogenesis of dysplastic kidney in a urinary tract obstruction in the female fetal lamb.

BACKGROUND/PURPOSE: The type of renal dysplasia resulting from obstructive uropathy depends on the completeness of the obstruction and its timing with respect to the stage of glomerulogenesis at the time of the obstruction. The authors created a successful obstructive uropathy model in the female fetal lamb to demonstrate the differing pathogenesis of renal dysplasia. METHODS: Female fetal lambs at 60 and 90 days' gestation had their urethra and urachus ligated transabdominally and were delivered by cesarean section at 145 days (full term). Kidney length and cortical thickness were measured, and samples were examined histologically. In the lambs operated on at 90 days, the urine was collected at delivery and Na and CI were measured and compared with the results obtained from normal full-term lambs. RESULTS: Seven of 10 female lambs had hydronephrosis or dysplastic kidneys. The cortext to kidney length ratio was 10+/-3% in the 90-days hydronephrotic group versus 29+/-6% in the controls (P<.001). Morphologically, the 90-day model had dilatation of the collecting tubules with normal glomerular numbers. The 60-day model had tubular cysts with fibromuscular cuffing and reduced glomerular numbers. The fetal urine Na was 47+/-3.3 mmol/L in controls versus 78+/-24 mmol/L in the hydropnephrotic lambs (P<.05). The urine CI in these lambs was 38+/-8.6 mmol/L in controls versus 55+/-14.5 mmol/L in the hydronephrotic lambs (P<.05). CONCLUSIONS: An obstructive uropathy model was created in female fetal lambs. There were no dysplastic changes in the kidneys in lambs operated on at 90 days' gestation, but there were definite dysplastic changes in those operated on at 60 days. Concentrations of Na and CI in the fetal urine are higher than normal in the 90-day model.

[Factors that affect DNA content analysis by flow cytometry]. / Aspectos que afectan el análisis de contenido de ADN por citometría de flujo.

DNA ploidy and cell cycle analysis by flow cytometry is used to obtain additional information about the diagnosis and prognosis of different types of cancer. However, there are several disagreements among authors about the tissue source (fresh-frozen or paraffin embedded), cellular dissociation methods (mechanical, enzymatic or other), use of different dyes, lasers, analysis software with different mathematical models and interpretation of results. A discussion about the different aspects that affect the study of DNA ploidy and cell cycle and a consensus in publications is mandatory. A strict control of analysis processes and data interpretation is also necessary.

Efficacy of exogenous fibronectin in wound healing in malnourished rats.

BACKGROUND/PURPOSE: Fibronectin (FN) plays an important role in fibrin matrix formation during the wound healing process. The authors investigated whether exogenous FN increases the bursting strength (BS) of surgical wounds in malnourished rats. METHODS: Ninety rats were grouped according to three nutritional conditions (n = 30 in each group). All animals underwent a transverse celiotomy after 3 weeks of feeding, and FN (2 mg/body/day) was given postoperatively to 15 rats in each of the three groups. Wound BS was measured on postoperative days (PODs) 3, 5, and 7 after removal of the sutures. RESULTS: BS in normally nourished rats (group N; 142.6+/-23.4 mmHg) was significantly higher than that in protein malnourished rats (group PM, 110.2+/-11.2 mm Hg) and protein/ calorie (Cal)-malnourished rats (group PCM, 76.5+/-10.7 mm Hg) on POD 7 (P<.01). However, BS values for groups PM + FN (147.0+/-21.1 mmHg) and PCM + FN (115.1+/-28.9 mm Hg) were intensified significantly in comparison with groups PM and PCM (P<.01). Plasma FN levels in rats of the three FN nontreated groups were similarly decreased on POD 3 or 5, but returned to the preoperative level on POD 7, whereas those for the other three FN-treated groups increased after POD 3. CONCLUSION: Intravenous administration of FN might strengthen the weakened wounds of malnourished animals.

Non-invasive assessment of language dominance with near-infrared spectroscopic mapping.

Hemispheric dominance for language is usually assessed by means of the Wada test where amobarbital is injected into the carotid artery. Recently, positron emission tomography and functional MRI have been used as non-invasive alternatives to this method. We have applied 24-channel near-infrared spectroscopic topography (NIRS) as another non-invasive method to detect the unilateral cerebral activation during a language task. We used 11 healthy volunteers and six patients with intractable epilepsy. A word-generation task was applied for 17 s, followed by an extinction/resting period of 60 s. In healthy volunteers, the inferior frontal region was activated on the side opposite to the subject's handedness in infancy. In the epilepsy cases, the activated side agreed with the dominance determined by the Wada test. Our results demonstrate that NIRS is a feasible non-invasive alternative to the Wada test.

Two cases of torsion of the gallbladder diagnosed preoperatively.

BACKGROUND: The authors experienced two cases of torsion of the gallbladder, both of which were correctly diagnosed preoperatively. METHODS: Two boys, aged 4 and 5 years, were transferred to Yokohama City Seibu Hospital because of their acute abdominal disorders. Diagnostic imaging demonstrated acute inflammatory changes in the gallbladder with an abnormal arrangement of the gallbladder and common bile duct in both cases. Laparotomy findings showed torsion of the gallbladder by 180 degrees and 360 degrees, respectively, at the cystic ducts, resulting in gangrenous change. RESULTS: Both children recovered uneventfully after cholecystectomy. The diagnostic imaging criteria are (1) collection of fluid between the gallbladder and the gallbladder fossa of the liver, (2) a horizontal rather than vertical arrangement of the long axis of the gallbladder, (3) the presence of a well-enhanced cystic duct located on the right side of the gallbladder, and (4) signs of inflammation including marked edema with thickening of the wall. CONCLUSIONS: The authors report the clinical characteristics of this uncommon condition, and discuss the significance of accurate preoperative diagnosis of these acute surgical disorders.

Digestive tract disorders associated with asplenia/polysplenia syndrome.

The authors reviewed experience gained over a 20-year period of asplenia or polysplenia syndrome, focusing on patients with associated digestive tract disorders (DTDs). Eleven of 27 patients (40%) with asplenia/polysplenia had associated DTDs. The DTDs comprised malrotation of the intestine in nine, both preduodenal portal vein and gastric volvulus in three, esophageal hiatal hernia in two, and biliary atresia in one. Laparotomy was carried out on four patients with symptoms of acute bowel obstruction and on one patient with biliary atresia. One patient with both malrotation and gastric volvulus, and another with only associated malrotation survived. Nine patients died, eight of cardiac insufficiency and one because of hepatic insufficiency. When infants are diagnosed with heterotaxia, they should be examined for other combined DTDs, because they may have a chance for survival if they undergo surgery when their condition is still stable.

Immunologic reaction and genetic factors in biliary atresia.

The characteristic histopathological features seen in the livers of patients with biliary atresia (BA) are very similar to those of primary biliary cirrhosis, which is an autoimmune disease. To clarify whether BA liver possess an immunological response similar to that in primary biliary cirrhosis, we studied HLA-DR expression in liver tissue of BA patients, using a HLA-DR staining method, and determined the frequency of HLA types in BA patients and their families. HLA-DR was expressed by the bile duct epithelium in 11 of 16 liver specimens obtained from 13 BA patients. By contrast, HLA-DR was not expressed in liver specimens from 6 patients with congenital biliary dilatation. Among the HLA types seen in BA patients and their families, HLA-A33, -B44 and -DR6 were frequently expressed in blood. These results suggest that certain immunological factors and disease-susceptible genes might be involved in the etiology of BA.

Unilateral pulmonary agenesis with tracheoesophageal fistula: a case report.

The authors describe a neonate with unilateral pulmonary agenesis and esophageal atresia (Gross type C). Definitive repair for the atresia was completed during the early neonatal period, and the patient is alive and well more than 1 year after surgery. Most patients with pulmonary agenesis associated with esophageal atresia have not survived, mainly because of postoperative cardiorespiratory failure. Early protection and preservation of respiratory units is essential for the management of these patients.

Doppler ultrasonographic evaluation of hepatic circulation in patients following Kasai's operation for biliary atresia.

The hepatic circulation of eight children who underwent Kasai's operation for biliary atresia was serially evaluated by Doppler ultrasonography (US). A total of 36 examinations were performed to evaluate the maximal velocities (mvs) of the main portal vein (MPV), splenic vein (SV), and hepatic artery (HA), and to analyze the spectral waveform and the directions of flow. The mean mvs-MPV in four patients for whom adequate biliary diversion had been achieved and whose serum bilirubin had fallen to within the normal range (group A), was 19.8 +/- 7.5 cm/s. Their MPV waveforms were constant, with blood flowing toward the liver, while their mean mvs-SV was 12.1 +/- 5.8 cm/s. In two other patients with apparent hypersplenism, but whose serum bilirubin levels had fallen to nearly normal (group B), the mean mvs-MPV was 20.7 +/- 10.4 cm/s and the mvs-SV was 22.4 +/- 10.4 cm/s. In contrast, the mvs-MPV in the two remaining patients, whose serum bilirubin levels had either not fallen to within the normal range, or had fallen initially but increased due to recurrent cholangitis (group C), was 14.2 +/- 9.1 cm/s. In these patients, the waveforms were unstable, the MPV flows were occasionally hepatofugal, and their mean mvs-SV was 18.0 +/- 5.8 cm/s. The mvs-HA were markedly increased in the latter four patients, whose clinical condition had also deteriorated. These observations led to the conclusion that hepatic circulation evaluated by serial Doppler US provides important information about liver status in children who have undergone Kasai's operation for biliary atresia.

Concentration measurements of a light absorber localized in a scattering medium.

Using a time-resolved technique, we have studied two methods of quantifying the concentration of a light absorber localized in a scattering medium. Because some of the transmitted photons pass through the absorber region many times because of complicated photon propagation in the scattering medium, we used the following methods. First, early-arriving photons passing through the absorber approximately once were selected. Using these photons, we quantified the concentration of the absorber by an ordinary spectroscopic method based on the Beer-Lambert law. Second, for later-arriving photons, after empirically determining the distribution of the number of passes through the absorber as a function of detection time, we obtained the concentration by applying this function to the Beer-Lambert law.

[Variation of the diploid pattern in tissues used as normal controls of solid tumors: advantages and disadvantages of flow cytometric analysis of paraffin-embedded tissues]. / Variación del patron diploide en tejidos usados como controles normales de tumores solidos: ventajas y desventajas del analisis fluocitométrico en tejidos incluidos en parafina.

The aim of the present work was to study the factors that influence the variation of diploid patterns in 75 areas of histologically normal gastric tissue, located in surgically resected stomachs due to early gastric cancer. Each sample was used as a diploid reference of its respective tumoral area. Fifty five samples were embedded in formalin and 20 corresponded to fresh tissue. It was found that in the older tissues, the cellular debris increased, the localization channel of the peaks shifted to the left (lower than channel 60) and the peak shape was deformed, with an increase in the variation coefficient (around 6) and an elevation and lengthening of phase S. When fresh tissue was used, the first peak was localized around channel 60-70, with a significant reduction of cellular debris, a lower variation coefficient amplitude (2-5) and a phase S adhered to the basal line. Aiming to observe the influence of paraffin embedding over time, 21 tissue samples originally assayed as fresh tissues, were reanalyzed one year later. The same alterations initially observed in old tissues were again noticed. According to these results, it is necessary to select adequate controls for flow cytometric analysis to obtain an adequate histogram interpretation, and specially to calculate the ADN index.