Influence of Nd:YAG laser on intrapulpal temperature and bond strength of human dentin under simulated pulpal pressure.

The aim of this study was to evaluate the effects of simulated pulpal pressure (SPP) on the variation of intrapulpal temperature (ΔT) and microtensile bond strength (µTBS) to dentin submitted to an adhesive technique using laser irradiation. One hundred sound human molars were randomly divided into two groups (n = 50), according to the presence or absence of SPP (15 cm H2O). Each group was divided into five subgroups (n = 10) according to Nd:YAG laser energy (60, 80, 100, 120, 140 mJ/pulse). The samples were sequentially treated with the following: 37 % phosphoric acid, adhesive (Scotchbond Universal), irradiation with Nd:YAG laser (60 s), and light curing (10 s). ΔT was evaluated during laser irradiation using a type K thermocouple. Next, a composite resin block was build up onto the irradiated area. After 48 h, samples were submitted to microtensile test (10 kgf load cell, 0.5 mm/min). Data were analyzed by two-way ANOVA and Tukey tests (p = 0.05). ANOVA revealed significant differences for ΔT and TBS in the presence of SPP. For ΔT, the highest mean (14.3 ± 3.23 °C)(A) was observed in 140 mJ and without SPP. For µTBS, the highest mean (33.4 ± 4.15 MPa)(A) was observed in 140 mJ and without SPP. SPP significantly reduced both ΔT and µTBS during adhesive procedures, lower laser energy parameters resulted in smaller ΔT, and the laser parameters did not influence the µTBS values.

Intestinal permeability in strongyloidiasis.

The objective of the present study was to assess intestinal permeability in patients with infection caused by Strongyloides stercoralis. Twenty-six patients (16 women and 10 men), mean age 45.9, with a diagnosis of strongyloidiasis were evaluated. For comparison, 25 healthy volunteers (18 women and 7 men), mean age 44.9, without digestive disorders or intestinal parasites served as normal controls. Intestinal permeability was measured on the basis of urinary radioactivity levels during the 24 h following oral administration of chromium-labeled ethylenediaminetetraacetic acid ((51)Cr-EDTA) expressed as percentage of the ingested dose. The urinary excretion of (51)Cr-EDTA was significantly reduced in patients with strongyloidiasis compared to controls (1.60 +/- 0.74 and 3.10 +/- 1.40, respectively, P = 0.0001). Intestinal permeability is diminished in strongyloidiasis. Abnormalities in mucus secretion and intestinal motility and loss of macromolecules could explain the impaired intestinal permeability.

Effect of a selective nonsteroidal anti-inflammatory inhibitor of cyclooxygenase-2 on the small bowel of rats.

The pathogenesis of nonsteroidal anti-inflammatory drug (NSAID) enteropathy is a complex process involving the uncoupling of mitochondrial oxidative phosphorylation and inhibition of cyclooxygenase (COX). Rofecoxib, a selective inhibitor of COX-2, has shown less gastric damage, but the same beneficial effect is not clear in the case of the small bowel. Fifty-seven male Wistar rats (250-350 g) were divided into three groups (N=19 each) to evaluate the effect of this NSAID on the rat intestine. The groups received 2.5 mg/kg rofecoxib, 7.5 mg/kg indomethacin or water with 5% DMSO (control) given as a single dose by gavage 24 h before the beginning of the experiment. A macroscopic score was used to quantify intestinal lesions and intestinal permeability was measured using [51Cr]-ethylenediaminetetraacetic acid ([51Cr]-EDTA). The extent of intestinal lesion, indicated by a macroscopic score, was significantly lower when rofecoxib was administered compared to indomethacin (rofecoxib=0.0 vs indomethacin=63.6 +/- 25.9; P<0.05) and did not differ from control. The intestinal permeability to [51Cr]-EDTA was significantly increased after indomethacin (control=1.82 +/- 0.4 vs indomethacin=9.12 +/- 0.8%; P<0.0001), but not after rofecoxib, whose effect did not differ significantly from control (control=1.82 +/- 0.4 vs rofecoxib=2.17 +/- 0.4%; ns), but was significantly different from indomethacin (indomethacin=9.12 +/- 0.8 vs rofecoxib=2.17 +/- 0.4%; P<0.001). In conclusion, the present data show that rofecoxib is safer than indomethacin in rats because it does not induce macroscopic intestinal damage or increased intestinal permeability.

[Assessment of arterial occlusive disease with Duplex sonography. Prospective study]. / Avaliação da doença oclusiva das artérias renais com Triplex Scan. Estudo prospectivo.

Occlusive disease involving the renal arteries represent a major cause of curable hypertension and improvement of renal dysfunction. Angiography is still the major diagnostic procedure. Isotopic methods with Captopril and split-function studies have shown high incidence of false-positive and false-negative results. Colour flow Duplex-Scan renders possible the visualization of the aorta and renal arteries, is noninvasive and combines morphologic and hemodynamic evaluation. To assess its efficacy in the diagnosis of renal artery occlusive disease, a prospective blind study was undertaken in 24 patients, 48 renal arteries, 15 women and 9 men, with mean age of 44 years. Scans of the aorta and renal arteries at the origin, along its extension and at the renal hilum were obtained using and ATL Ultrmark 9 with 3.0 MHZ probe Velocity measurements were obtained at the aorta and along the renal arteries. Criteria for a positive examination were: focal acceleration with a reduction of the flow velocity at the hilum. Absence of flow in a properly visualized renal artery was considered as occlusion. All patients had digital subtraction arteriography. In 1 patient the non-invasive examination was inadequate. In the remain 23 patients the exam was considered adequate. False-positives were 4.8%; false-negatives 8.7%. Sensitivity, specificity and accuracy were respectively 91.7%, and 95.7% and 93.5%. These results suggest that non-invasive assessment of renal artery occlusive disease is feasible and accurate when compared to angiography, thus providing a useful tool for screening hypertensive patients.

[Postoperative jaundice syndrome after mitral valve replacement. A case report]. / Síndrome de icterícia pós-operatória após substituição valvar mitral. Relato de caso.

A 52-year old woman was submitted to mitral valve replacement. The operation proceeded without complications. Jaundice had been noted since the first postoperative (po) day and increased progressively due to conjugated bilirubin. Abdominal examination was normal and no signs of infection or circulatory failure were noted. Conjugated bilirubin levels increased from 6 mg/dl on the second po day to 20.4 mg/dl on the sixth po day and to 32 mg/dl on the tenth po day. Gammaglutamyl transferase levels were 600 U/L (normal up to 18 U/L) and lactate dehydrogenase levels were 396 U/L (normal) up to 240 U/L) on the seventh po day. Alkaline phosphatase levels were 1880 U/L (normal up to 170 U/L) whereas glutamic oxalacetic transaminase levels were 60 U/L (normal up to 15 U/L) and glutamic pyruvic transaminase levels were 66 U/L (normal up to 17 U/L) on the tenth po day. Abdominal ultrasonography did not disclose dilatation of intra and extra-hepatic biliary system. The patient died after a percutaneous hepatic biopsy procedure. The jaundice was attributed to a cholestatic syndrome after cardiac surgery and cardiopulmonary bypass, due to an impairment of the excretory function of the hepatocyte.

[The role of stents in endovascular surgery]. / O stent na cirurgia endovascular.

Stent appears as the most recent and revolutionary acquisition in Endovascular Surgery. It represents the percutaneous permanent placement of a Vascular prosthesis. We discuss its background and evolution, the several types as well as some of its characteristics as biocompatibility, trombogenicity and biomechanics. We also describe practical aspects concerning the placement procedure. It is also discussed the present day prespectives and the future.

[Lymphangioma of the mediastinum as a cause of chylopericardium]. / Linfangioma mediastínico como causa de quilopericárdio.

Chylopericardium is a rare from of pericardial effusion. A case of a ten-year-old female patient with a chylopericardium incidentally detected during a mild respiratory infection through cardiac enlargement at the chest X ray is reported. The techniques used to achieve this diagnosis are described, a special emphasis being put on the CT-scan and lymphangiography, which have not been used in such cases so far. These techniques provided very useful data which were determinant for the success of the proposed therapy. This and other cases reported in the paper indicate that the most common cause of primary chylopericardium is a mediastinal lymphangioma.

[Prevalence of extracranial carotid occlusive disease. Non-invasive study]. / Prevalência da doença carotídea oclusiva extracraneana. Estudo não-invasivo.

Cerebrovascular disease is the most important cause of mortality and morbility in some European Countries, but the prevalence of carotid occlusive disease has not been adequately assessed. From 1985 to 1987, 1,143 patients were consecutively evaluated in the Vascular Laboratory in order to determine the presence of extracranial carotid occlusive disease. 638 (55.8%) were males and 505 (44.2%) females and mean age was 58 years (16-87). 509 had previously focal brain ischemia, ocular and/or hemispheric (Group I), 78 had assymptomatic cervical bruit (Group II), 55 non-hemispheric neurologic dysfunction (Group III) and 501 had atypical symptoms for cerebrovascular disease (Group IV). Diagnostic criteria for carotid disease: were peak frequency greater than 4.0 KHz; spectral broadening greater than 40% and late sysstolic turbulence. Global prevalence of carotid disease was 31.8% and the results in each group were: Gr. I-37.2%; Gr. II-57.7%; Gr. III-43.6%; Gr. IV-21.2%. 49% of the patients had hypertension, 22.8% dyslipidemia, 22.4% evidence of coronary disease and 13.6% had diabetes. Hypertension, diabetes, coronary disease and the coexistence of two risk factors were significantly more prevalent in the group of patients with carotid disease. These results confirm a high prevalence of carotid disease in this population, which is comparable to the one is northern european populations.

[Carotid artery surgery in extracranial occlusive disease and cerebral ischemia. Early and late results]. / Cirurgia carotídea na doença oclusiva extracraneana e isquemia cerebral. Resultados precoces e tardios.

Carotid artery surgery became an established procedure for the treatment of cerebrovascular insufficiency associated with carotid artery stenosis and for the prevention of Stroke. 180 patients were consecutively treated because of occlusive disease of the carotid arteries: 152 (84%) had TIA's or reversible deficits, 11 (6.1%) had strokes with partial recovery, 16 (8.8%) asymptomatic carotid disease and 1 patient (0.5%) had global cerebral ischemia. The severity of occlusive disease was assessed by ECHO-DOPPLER, with or without colour mapping and by angiography: 21 had minimal lesions (less than 20%), 58 stenosis between 21-75%, 92 stenosis between 76-99% and 7 had complete occlusion of the carotid artery; 2 patients had aneurysmal disease 196 operations were performed; early mortality (less than 30 days) was 2.2% (4/180) and neurological morbidity 1.6% (3/180), the operative risk being 3.8%. Longterm results were assessed during a follow-up period extending to 132 months and were assessed by life-table analysis. Survival was 52.5%, 79.3% of the patients were fully asymptomatic during the follow-up but 89.2% were stroke-free, the incidence of stroke being 0.97%/year. These results compare favorably with data available from the natural history and confirm the efficacy of carotid artery reconstructive surgery for the prevention of stroke.

[Salicylic derivatives in the clinical treatment of inflammatory bowel disease: new perspectives]. / Derivados salicílicos no tratamento clínico da doença inflamatória intestinal: novas perspectivas.

Sulfasalazine is one of the most used drugs in the clinical management of inflammatory bowel disease. Nevertheless up to 30% of the patients experiment side effects related to the drug and end up having the drug diminished or withdrawn. The new salicylic-derivate compounds emerge as a reliable alternative for these patients. The authors review the new preparations and discuss their characteristics, indications and side effects.

[Lymphography in the clinical picture of lymphedema]. / La lymphographie dans la clinique des lymphoedèmes.

The value of lymphography in the clinical treatment of lymphatic edemas is examined. Since its invention by Hernani Monteiro, lymphography has not enjoyed the same success as clinical phlebography, which has benefited from anatomical and physiological knowledge and has clarified several problems. Great gaps still exist in our knowledge of the anatomy, physiology and physiopathology of the lymphatic system, and this explains the limited development of lymphography so far, and the difficulty of interpreting and characterizing cases of lymphatic stasis. This situation has also hindered the development of logical and effective therapies. We believe that new techniques should be developed for use in lymphography, as was necessary in phlebography.

[Chylomicron metabolism in experimental cholestasis]. / Metabolismo de quilomícros na colestase experimental.

Cholesterol and triglyceride plasma levels are usually increased in cholestasis. The excess of cholesterol and that of triglyceride are carried in abnormal low-density lipoproteins (LP) named LP-X and beta 2-LP respectively. It has been assumed that chylomicron metabolism is involved in these alterations. To gain insight into the LP disturbances in this pathology, artificial chylomicrons (AC) were prepared in protein-free aqueous solutions containing lecithin, cholesteryl-oleate, cholesterol and triolein. AC were labelled simultaneously with cholesteryl--14C-oleate (14C-CO) and 3H-triolein (3H-TO) and pulse injected intra-arterially in rats subjected to total obstruction of the bile duct for 48 hours and sham-operated rats. Blood was collected at 2-minute intervals during 10 minutes for radioactivity determination. Fractional clearance rates of 3H-TO and 14C-CO were diminished. Since plasma decay of 3H-TO reflects predominantly the rate of lipolysis (L) whereas chylomicron remnant removal (CRR) by the liver is represented by the 14C-CO decay, our data suggest that in cholestasis both L and CRR are defective.

Optical and crystalline properties of PbF(2) thin films.

The optical and crystalline properties of PbF(2) thin films as a function of the substrate temperature during deposition have been studied; the other evaporation conditions were kept as constant as possible. Channel spectra, guided modes, and ellipsometry techniques were used for the analysis of the optical properties of the films. X-ray diffraction was used for the analysis of the crystalline structure.

[Chylomicron metabolism]. / Metabolismo de quilomicros.

The liver is known to play a central role in the chylomicron metabolism. It synthesizes apolipoproteins (e.g., apo A I, apo C II, apo E), lecithin cholesterol acyltransferase, hepatic lipase and is responsible for the chylomicron remnant removal. Not surprisingly then the chylomicron metabolism is compromised in liver diseases such as acute hepatitis, cirrhosis and cholestasis. The authors reviewed the normal features of the chylomicron metabolism which are essential for a better understanding of the lipoprotein disturbance in liver diseases.

Dentin bond strength: influence of laser irradiation, acid etching, and hypermineralization.

OBJECTIVE: The purpose of the present study was to investigate the effects of ND:YLF laser irradiation (1.31 J/cm2; 250 mJ per pulse), acid etching, and hypermineralization on the shear bond strength (SBS) of the Scotchbond Multi-Purpose Plus (3M Dental Products) bonding system. SUMMARY BACKGROUND DATA: Previous studies had shown that the pretreatment of the dentin substrate with laser irradiation can influence the SBS. METHODS: Sixty bovine incisors were selected and stored at -18 degrees C. Dentinal buccal surface was exposed and radiographs were taken to control dentin thickness. The specimens were separated into 2 groups: (1) the control, which was kept in distilled water at 4 degrees C; (2) the hypermineralized, which was kept in hypermineralizing solution at 4 degrees C for 14 days. Each group was divided into 3 subgroups according to the type of dentin pretreatment used: M (acid etching + primer + bond); AL (acid etching + primer + bond + laser); and LA (laser + acid etching + primer + bond). A standard composite resin cylinder (Z100-3M) was bonded to the dentinal surface and the SBS performed on an Instron machine (500 Kg load cell at 0.5 mm/min), followed by scanning electron microscopy (SEM) and x-ray diffraction analysis. RESULTS: Analysis of variance (ANOVA) determined that the pretreatments influenced the SBS values (p < 0.05): AL (9.96 MPa), M (7.28 MPa), and LA (4.87 MPa). The interaction between the group and pretreatment factors also influenced the SBS (p < 0.05). The highest values were obtained for the interaction control/AL (11.64 MPa). CONCLUSION: The results suggested that dentin treatment with laser after the application of the adhesive system is efficient in achieving higher bond strength and is promising as a possible new adhesive substrate.