Adaptación marginal de coronas de disilicato de litio obtenidas mediante técnicas de escaneo (CAD/CAM): análisis in vitro con microscopía confocal / Marginal adaptation of lithium disilicate crowns obtained by scanning techniques (CAD/CAM): in vitro confocal microscopy analysis

Objetivo. El objetivo de este estudio fue evaluar la adaptación marginal de coronas de disilicato de litio obtenidas mediante técnicas de escaneo (CAD/CAM), antes y des- pués de la cristalización, a través de análisis in vitro con microscopía confocal (MC). Métodos. Fueron confeccionadas 16 réplicas en poliuretano a partir de la pieza 1.4, de modelo typodont, tallada para corona total. Las réplicas fueron divididas en dos gru- pos, de acuerdo a la técnica de escaneo: Técnica Indirecta (Grupo IND, n=08), donde modelos de yeso fueron escaneados con escáner de laboratorio (inEos X5, Sirona Den- tal Systems) y Técnica Directa (Grupo DIR, n=08), donde modelos typodont fueron escaneados con escáner intraoral (CEREC BlueCam, Sirona Dental Systems). A seguir, se fresaron (inLab MC XL, Sirona Dental Systems) coronas en disilicato de litio (IPS e.max CAD, Ivoclar Vivadent) y se adaptaron a las réplicas. Se evaluó la adaptación marginal con análisis de MC en dos momentos, antes y después de la cristalización del disilicato de litio. Los datos fueron analizados con la prueba de Mann-Whitney, t de Student y Wilcoxon (α= 0,05). Resultados. Hubo una diferencia estadísticamente significativa en la adaptación marginal horizontal entre los grupos IND y DIR después de la cristalización (p=0,05). En el grupo IND, la comparación de la adaptación mar- ginal vertical antes y después de la cristalización mostró una diferencia estadísticamente significativa (p=0,038). Conclusiones. Las coronas de disilicato de litio obtenidas me- diante escaneo directo (CAD/CAM) presentaron menor desajuste marginal vertical. La etapa de cristalización afectó la adaptación marginal de las coronas.

Objective. This study aimed to evaluate lithium disilicate marginal adaption on crowns by scanning techniques (CAD/CAM), before and after crystallization, through confocal microscopy (CM) in vitro analysis. Methods. Sixteen polyurethane replicas were per- formed from tooth 1.4, of a typodont model, prepared for a full crown. The replicas were divided into two groups, according to the scanning technique: Indirect Technique (Group IND, n=08), where dental stone models were scanned with a laboratory scanner (inEos X5, Sirona Dental Systems) and Direct Technique (Group DIR, n=08), where typodont models were scanned with an intraoral scanner (CEREC BlueCam, Sirona Dental Systems). Then, the lithium disilicate crowns (IPS e.max CAD, Ivoclar Vivadent) were milled (inLab MC XL, Sirona Dental Systems) and adapted to the replicas. Margin- al adaptation was evaluated with CM analysis before and after lithium disilicate crystalli- zation. Data were analyzed with the Mann-Whitney, t test, and Wilconxon test (α=0.05). Results. There was a statistically significant difference in horizontal marginal adaptation between IND and DIR groups after crystallization (p=0.05). In IND group, the compar- ison of vertical marginal adaptation before and after crystallization showed a statistically significant difference (p=0.038). Conclusions. Lithium disilicate crowns obtained by direct scanning technique (CAD/CAD) showed less vertical marginal maladjustment. The crystallization stage affected the crown's marginal adaptation.

Dental unit water: bacterial decontamination of old and new dental units by flushing water.

OBJECTIVE: To evaluate by means of Petrifilmtrade mark system (3M, St Paul, MN, USA) the level of bacterial contamination in water from old and new dental units (air-water syringes and high-speed turbines) before and after flushing water through waterlines. The old dental units had been used for 13 years and the new dental units for 1 year. A fast method named Petrifilmtrade mark AC (3M) was employed to evaluate the level of water contamination with total aerobic bacteria and Petrifilmtrade mark EC for Escherichia coli and coliforms. METHODS: Dental unit water were collected before and after flushing of 4 (air-water syringes) and 2 min (high-speed turbines) from 24 old and new dental units. Thereafter, samples were diluted, inoculated onto Petrifilmtrade mark plates and incubated. RESULTS: The filtered tap water that filled up dental unit reservoirs showed a low level of bacterial contamination (4 and 15 CFU ml(-1)). However, all water samples from old and new dental units were highly contaminated. The flushing of dental unit waterlines reduced the bacterial count in all dental unit water, but the reduction was better in water from new dental units than from old dental units. E. coli and coliforms were not detected in any water samples analysed. CONCLUSION: Flushing water is a simple measure that should do part of dental routine, because it was able to reduce the level of total aerobic bacteria in water from old and new dental units.

Lack of chemopreventive effects of alpha-eleostearic acid on 7,12-dimethylbenz[a]anthracene (DMBA) and 1,2-dimethylhydrazine (DMH)-induced mammary and colon carcinogenesis in female Sprague-Dawley rats.

alpha-Eleostearic acid is one of the conjugated linolenic acids from tung oil, which is obtained from the seeds of Aleurites fordii. The effects of dietary alpha-eleostearic acid (18:3, n-5) on the post-initiation period of 7,12-dimethylbenz[a]anthracene (DMBA) and 1,2-dimethylhydrazine (DMH)-induced mammary and colon carcinogenesis were examined using female Sprague-Dawley (SD) rats. For initiation, rats were given subcutaneous injections of 40mg/kg body weight (5 times) and 20mg/kg body weight (3 times) of DMH during the age of 6-8 weeks and a single intragastric administration of 50mg/kg body weight of DMBA at 9 weeks. Then, the animals were treated with 0%, 0.01%, 0.1% or 1.0% alpha-eleostearic acid for 34 weeks. Control rats received the basal diet alone or 1.0% alpha-eleostearic acid without prior initiation treatment. All surviving animals were killed at week 37 of the experiment. There were no statistically significant alterations in any of the parameters for either mammary or colon tumors. These results thus indicate that alpha-eleostearic acid does not exert clear modification effects on DMBA and DMH-induced mammary and colon carcinogenesis, at least under the present experimental conditions.

A C77G point mutation in CD45 exon 4, which is associated with the development of multiple sclerosis and increased susceptibility to HIV-1 infection, is undetectable in Japanese population.

HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) is one outcome of Human T-cell lymphotropic virus type 1 (HTLV-1) infection. It remains unknown why the majority of infected people remain healthy whereas only approximately 2-3% develop disease. Recently, heterozygous state of CD45 exon 4 mutation (C77C wild type and C77G mutant) was reported to be associated with development of multiple sclerosis in German patients and increased susceptibility to HIV-1 infection in the United Kingdom. To investigate whether this mutation is associated with the development of HAM/TSP, we studied a group of 164 HAM/TSP patients and 108 asymptomatic HTLV-1 carriers in Kagoshima (HTLV-1 endemic area in Southern Japan) by using PCR-RFLP and subsequent direct sequencing analysis. All 272 subjects showed homozygosity in the CD45 exon 4, suggesting that this mutation is absent or very rare in Japanese population.

Collarless metal ceramic fixed partial denture: a clinical report.

A case of a collarless metal ceramic fixed partial denture with preparations made at a slightly supragingival level is reported. The absence of the metal collar in the buccal portion of the abutments provides an excellent esthetic appearance. The use of a collarless metal ceramic fixed partial denture is a viable approach for restoring dentition where the esthetic quality is the primary concern.

CD45 is a JAK phosphatase and negatively regulates cytokine receptor signalling.

The regulation of tyrosine phosphorylation and associated signalling through antigen, growth-factor and cytokine receptors is mediated by the reciprocal activities of protein tyrosine kinases and protein tyrosine phosphatases (PTPases). The transmembrane PTPase CD45 is a key regulator of antigen receptor signalling in T and B cells. Src-family kinases have been identified as primary molecular targets for CD45 (ref. 4). However, CD45 is highly expressed in all haematopoietic lineages at all stages of development, indicating that CD45 could regulate other cell types and might act on additional substrates. Here we show that CD45 suppresses JAK (Janus kinase) kinases and negatively regulates cytokine receptor signalling. Targeted disruption of the cd45 gene leads to enhanced cytokine and interferon-receptor-mediated activation of JAKs and STAT (signal transducer and activators of transcription) proteins. In vitro, CD45 directly dephosphorylates and binds to JAKs. Functionally, CD45 negatively regulates interleukin-3-mediated cellular proliferation, erythropoietin-dependent haematopoieisis and antiviral responses in vitro and in vivo. Our data identify an unexpected and novel function for CD45 as a haematopoietic JAK phosphatase that negatively regulates cytokine receptor signalling.

Tooth wear: use of overlays with metallic structures.

This work is a clinical case report of a patient presenting with marked tooth wear in all teeth, a reduction in the vertical dimension of occlusion, and fatigue in the muscles of mastication. The treatment proposed and effected used a muscle-relaxing appliance and mandibular and maxillary overlay appliances which were adjusted according to the occlusal contacts, vertical dimension of occlusion, and the mandibular positioning. The results obtained were satisfactory in terms of relaxing the muscles involved, reestablishing the dimensions of the lower third of the face, and the functional activities of deglutition, mastication, and speech.

HLA alleles determine human T-lymphotropic virus-I (HTLV-I) proviral load and the risk of HTLV-I-associated myelopathy.

The risk of disease associated with persistent virus infections such as HIV-I, hepatitis B and C, and human T-lymphotropic virus-I (HTLV-I) is strongly determined by the virus load. However, it is not known whether a persistent class I HLA-restricted antiviral cytotoxic T lymphocyte (CTL) response reduces viral load and is therefore beneficial or causes tissue damage and contributes to disease pathogenesis. HTLV-I-associated myelopathy (HAM/TSP) patients have a high virus load compared with asymptomatic HTLV-I carriers. We hypothesized that HLA alleles control HTLV-I provirus load and thus influence susceptibility to HAM/TSP. Here we show that, after infection with HTLV-I, the class I allele HLA-A*02 halves the odds of HAM/TSP (P < 0.0001), preventing 28% of potential cases of HAM/TSP. Furthermore, HLA-A*02(+) healthy HTLV-I carriers have a proviral load one-third that (P = 0.014) of HLA-A*02(-) HTLV-I carriers. An association of HLA-DRB1*0101 with disease susceptibility also was identified, which doubled the odds of HAM/TSP in the absence of the protective effect of HLA-A*02. These data have implications for other persistent virus infections in which virus load is associated with prognosis and imply that an efficient antiviral CTL response can reduce virus load and so prevent disease in persistent virus infections.

The second domain of the CD45 protein tyrosine phosphatase is critical for interleukin-2 secretion and substrate recruitment of TCR-zeta in vivo.

The CD45 protein tyrosine phosphatase (PTPase) has been shown to regulate the activity of Lck and Fyn protein tyrosine kinases in T cells. However, it is not clear that these constitute the only CD45 substrates. Moreover, the manner by which PTPase activity and substrate recruitment are regulated, is poorly understood. Previous in vitro studies suggest that the first cytoplasmic PTPase domain (D1) of CD45 is the active PTPase, which may be regulated by an enzymatically inactive second PTPase domain (D2). However, the function of CD45 D2 in vivo is unknown. In this study, reconstitution of CD45(-) T cells with specific CD45 PTPase mutants allowed demonstration of a critical role for D2 in TCR-mediated interleukin (IL)-2 production. Specifically, replacement of CD45 D2 with that of the LAR PTPase to form a CD45/LAR:D2 chimera, abrogates CD45-dependent IL-2 production. This effect cannot be accounted for by loss of PTPase activity per se. The expression of D1 substrate-trapping mutants reveals an in vivo interaction between CD45 and TCR-zeta that is dependent on CD45 D2. Thus, cells expressing CD45 lacking D2 exhibit abnormal TCR-mediated signaling characterized by hyperphosphorylation of zeta and deficient ZAP-70 phosphorylation. These data suggest an essential role for CD45 D2 in TCR-regulated IL-2 production through substrate recruitment of the zeta chain.

Anterior esthetic rehabilitation of all-ceramic crowns: a case report.

A patient had a serious esthetic problem: One maxillary central incisor was discolored and the other was malpositioned and fractured. The fabrication of two all-ceramic crowns fulfilled both functional and esthetic objectives.

[Epidemiological trends for malaria in the cities of the upper Paraguay River basin, Mato Grosso do Sul, Brazil 1990-1996]. / Comportamento epidemiológico da malária nos municípios que compõem a Bacia do Alto Paragguai, Mato Grosso do Sul, no período de 1990 a 1996.

Through the Regional Office of the Brazilian National Health Foundation in the State of Mato Grosso do Sul, we obtained numerical data on malaria for the upper Paraguay basin (UPB): 159 cases in 1990, 126 in 1991, 135 in 1992, 61 in 1993, 143 in 1994, 41 in 1995, and 20 in 1996, the majority of which were imported cases. There were no autochthonous cases in 1990, and since 1991 the rates of over 15% dropped to around 1.60%. Imported cases, corresponding to 0. 63% in 1990, increased in 1991 and 1992 to some 1.50%, and to 3.28% in 1993. Induced cases were recorded only in 1991 and 1992 (less than 1%). Most cases were between 16 and 45 years of age. There was a predominance of Plasmodium vivax in the thick blood smears. Although autochthonous cases of malaria are not the majority, the disease is still an important public health problem in the UPB in the presence of the Anopheles (N.) darlingi vector and human migration into the region.

Analysis of HTLV-I proviral load in 202 HAM/TSP patients and 243 asymptomatic HTLV-I carriers: high proviral load strongly predisposes to HAM/TSP.

In order to examine the effect of HTLV-I proviral load on the pathogenesis of HAM/TSP, we measured the HTLV-I proviral load in peripheral blood mononuclear cells (PBMC) from a large number of HAM/TSP patients and asymptomatic HTLV-I carriers. To measure the proviral load, we used an accurate and reproducible quantitative PCR method using a dual-labeled fluorogenic probe (ABI PRISM 7700 Sequence Detection System). The mean +/- standard error of mean (s.e.m.) HTLV-I proviral copy number per 1 x 10(4) PBMC was 798 +/- 51 (median 544) in 202 HAM/TSP patients; 120 +/- 17 (median 34) in 200 non HAM-related (general) asymptomatic HTLV-I carriers (RC); and 496 +/- 82 (median 321) in 43 asymptomatic HTLV-I carriers genetically related to HAM/TSP patients (FA). The prevalence of HAM/TSP rises exponentially with log (proviral load) once the proviral load exceeds 1% PBMC. The HTLV-I proviral load of female patients with HAM/TSP was significantly higher than that of male patients, however there was no significant difference in proviral load between sexes in RC. There was a significant correlation between the proviral load and the concentration of neopterin in CSF of HAM/TSP patients. These results indicate that the HTLV-I proviral load in PBMC may be related to the inflammatory process in the spinal cord lesion. The increased proviral load in FA suggests the existence of genetic factors contributing to the replication of HTLV-I in vivo.

Mucolipidosis III (pseudo-Hurler polydystrophy); clinical studies in aged patients in one family.

Three adult patients (38-year-old male, 86-year-old female, and 61-year-old male) in a family with mucolipidosis III (ML-III) were described. They had characteristic features of ML-III and they survived a long time. N-acetylglucosaminyl 1-phosphotransferase activity was low in fibroblasts of a patient, but its residual activity remained at a relatively high level (24.5-35.3% of controls), which may explain the benign clinical course. Odontoid dysplasia and atlanto-axial dislocation was found in one patient, and surgical treatment improved his physical disability. Bilateral carpal tunnel syndrome as well as claw hand deformities were common in all of the patients. The clinical manifestations were important for the diagnosis and the management of the patients.

Protease activity appeared after trypsin treatment of the purified vitellogenin from eel Anguilla japonica.

Density gradient ultracentrifugation and anion-exchange chromatography combination were effective for the purification of the eel vitellogenin from the plasma of estradiol-treated eels. The vitellogenin was very high density glycolipoprotein (P = 1.27 g/ml) and its apolipoprotein was M(r) 196 k in both reduced and non-reduced conditions by SDS-PAGE. The major lipid component was phospholipid. The N-terminal amino-acid sequence of the vitellogenin was as follows: (Ac)Thr-Pro-Ala-Leu/Ala-Asp-Tyr. Amino-acid composition of the eel vitellogenin was similar to those of other teleosts. The protease activity appeared in the trypsinized vitellogenin, but was not detected in the purified vitellogenin. The protease was separated from the used trypsin and the other cleaved vitellogenin by a dextran sulfate cellulose column. The molecular weight of the protease was determined by zymogram using SDS-polyacrylamide gel containing casein and was 50 k. It was concluded that the eel vitellogenin possesses the protease activity as a latent form.

Comparative study of the direct-lift and platinum foil techniques in the marginal discrepancy of collarless metal ceramic restorations.

This study was carried out to evaluate the marginal discrepancy of collarless metal ceramic restorations, using a combination of three different techniques to manufacture the porcelain butt margin with two brands of body porcelain. Statistical analysis showed no significant difference between the techniques or brands of body porcelain used in this study.

Deletion in chromosome 17p11.2 including the peripheral myelin protein-22 (PMP-22) gene in hereditary neuropathy with liability to pressure palsies.

We report the clinical, electrophysiological, and pathological findings of two unrelated Japanese families with hereditary neuropathy with liability to pressure palsies (HNPP) and confirm the findings of a deletion of peripheral myelin protein-22 (PMP-22) gene. Electrophysiological studies revealed slowing of nerve conduction velocities of the affected nerves. Sural nerve biopsy revealed regions of myelin duplication. The copy numbers of PMP-22 gene was lower than that of normal control, suggesting deletion of 17p11.2 including PMP-22 gene. Our results indicate that HNPP in these two Japanese families is attributable to deletion of 17p11.2 including PMP-22 gene.

E5510 antagonizes thrombin receptor signals by inhibiting NF-kappa B activation.

We have recently demonstrated that NF-kappa B is involved in a thrombin-signaling and that the antisense oligodeoxynucleotides (ODNs) of NF-kappa B has a marked inhibitory effect on thrombin-induced cellular responses. In this study, we demonstrate that E5510 (4-cyano-5,5-bis(methoxyphenyl)-4-pentenoic acid), a compound with anti-platelet activity preferentially inhibits the thrombin-inducible NF-kappa B activation and then antagonizes the following thrombin-induced cellular responses, proliferation and cytokines production in vascular smooth muscle cell, and the adherency of differentiated HL-60 cells. These data suggest that E5510 is an anti-atherosclerotic or anti-restenotic drug induced by thrombin.

[Platelet functions in atherosclerosis].

Recent advances on platelet functions involved in atherosclerosis and subsequent thromboembolic diseases are reviewed. Platelets show multiple roles in hemostasis/thrombosis, wound healing, allergy, inflammation, metastasis of malignant cells and vasospasms through aggregation/secretion reaction. In atheromatous plaque, migration and proliferation of vascular smooth muscle cells and macrophages are the most prominent findings. In this pathological state, platelet may play as an enhancer by the secretion of bioactive substances including platelet-derived growth factor, serotonin and platelet factor 4. Investigation on platelet dynamics must be carried out not only for monitoring but also for the assessment of progressive factors in atherosclerotic disease.

Spontaneous orbital hemorrhage in adult females. A report of three cases.

Three cases of spontaneous orbital hemorrhages in 3 adult females are reported. All of the patients had acute radiating pain in the orbit, vomiting and proptosis with a limitation of motility and ecchymosis of the eyelids. One was due to a large orbital varix with a preceding history of intermittent exophthalmos; the causes of the other cases could not be determined from their backgrounds. Within a few weeks, all of them had recovered from hematoma and had good prognoses without surgery. Orbital venous bleeding with 40 mm Hg pressure will cause more than 500 g tension on the four rectus muscles. To treat this clinical emergency, hemostasis with compression in the early phase and waiting for its spontaneous absorption are recommended.

[A case of scapuloperoneal atrophy with rigid spine having lobulated fibers in muscle biopsy].

The patient, a 52-year-old male, noticed abnormalities on walking at about 20 years of age, followed by slowly progressive muscle weakness of arms and neck. The family history was negative. He showed muscular atrophy and weakness with a preferential involvement of the scapular, arms and peroneal muscles. Deep tendon reflexes were absent. He had a limited range of motion in the spine, but the onset was unclear. Creatine kinase (CK) was elevated (324 IU/L) and the EMG study showed myogenic pattern. Muscle biopsy was obtained from the biceps brachii muscle; on NADH dehydrogenase stain, there was subsarcolemmal increase in the oxidative enzyme activity showing "lobulated fiber" mostly seen in type 1 fibers. On electron-microscopy, the sub-sarcoplasmic areas which had high NADH activity, contained many mitochondria and glycogen particles. However, iodine-glycogen complex spectrum analysis pattern and debranching enzyme activity were normal. CT scan revealed low density in the paravertebral muscles, suggesting degeneration. This is a rare type of scapuloperoneal atrophy different from Emery-Dreifuss syndrome, rigid spine syndrome and FSH type muscular dystrophy.