Advancements in Free-Radical Pathologies and an Important Treatment Solution with a Free-Radical Inhibitor.

Unsaturated carbon-carbon double bonds particularly at exposed end groups of nonsolid fluids are susceptible to free-radical covalent bonding on one carbon atom creating a new free radical on the opposite carbon atom. Subsequent reactive secondary sequence free-radical polymerization can then continue across extensive carbon-carbon double bonds to form progressively larger molecules with ever-increasing viscosity and eventually produce solids. In a fluid solution when carbon-carbon double bonds are replaced by carbon-carbon single bonds to decrease fluidity, increasing molecular organization can interfere with molecular oxygen (O2) diffusion. During normal eukaryote cellular energy synthesis O2 is required by mitochondria to combine with electrons from the electron transport chain and hydrogen cations from the proton gradient to form water. When O2 is absent during periods of irregular hypoxia in mitochondrial energy synthesis, the generation of excess electrons can develop free radicals or excess protons can produce acid. Free radicals formed by limited O2 can damage lipids and proteins and greatly increase molecular sizes in growing vicious cycles to reduce oxygen availability even more for mitochondria during energy synthesis. Further, at adequate free-radical concentrations a reactive crosslinking unsaturated aldehyde lipid breakdown product can significantly support free-radical polymerization of lipid oils into rubbery gel-like solids and eventually even produce a crystalline lipid peroxidation with the double bond of O2. Most importantly, free-radical inhibitor hydroquinone intended for medical treatments in much pathology such as cancer, atherosclerosis, diabetes, infection/inflammation and also ageing has proven extremely effective in sequestering free radicals to prevent chain-growth reactive secondary sequence polymerization.

[Clinical experience of 302 cases with brain abscess].

Objective: To compare the diagnosis and treatment experience of brain abscesses and improve prognosis. Methods: The data of 302 patients of brain abscess at Department of Neurosurgery in Tianjin Medical University General Hospital from 1980 to 2014 was analyzed retrospectively. There were 215 male and 87 female patients aged from 11 to 82 years with mean age of (30±8) years. The patients was divided into 1980-2001 group and 2002-2014 group according to different diagnosis and the treatment methods. The therapy methods include operation and conservative treatment. There were 196 cases received operation, including 95 cases of excision, 89 cases of ventriculopuncture, 12 cases of excision after ventriculopuncture, 106 cases received drug conservative therapy. Two groups of information including clinical manifestation, abscess location, therapeutic effect and prognosis were compared by χ(2) test. Results: Compared to 1980-2001 group, adjacent infection incidence declined(χ(2)=8.000, P=0.005). The ratio of single abscess declined and multiple abscess increased(χ(2)=11.060, P=0.001), the infection proportion of frontal lobe and temporal lobe decreased(χ(2)=9.080, P=0.003; χ(2)=15.440, P=0.000). The ratio of headache and vomit and papilledema declined significantly(χ(2)=23.290, P=0.000; χ(2)=21.020, P=0.000; χ(2)=2.290, P=0.001). Total mortality of 302 patients were 23 cases and 5 cases of 1980-2001 group and 2002-2014 group (10.4% vs. 6.3%, χ(2)=1.180, P=0.277). However, there were statistical difference in postoperative mortality between both groups (14.4% vs. 4.0%, χ(2) =3.880, P=0.049). Conclusion: With the application of antibiotics and the development of neurosurgical techniques, the prognosis of brain abscess has been improved.

An analysis of the implant-supported overdenture in the edentulous mandible.

This investigation examined the cumulative survival rate of the implant-supported overdenture using two types of attachments in patients treated at Show Chwan Memorial Hospital Implant Center from 1992 to 2006. Fifty-one patients (30 men and 21 women) were treated with mandibular implant-supported overdentures. Attachment systems used were the Hader bar with bilateral, cast ERA attachments (Group A, 31 patients with 15 men and 16 women, 134 implants) and the Hader bar with bilateral, distal extension cantilevers (Group B, 20 patients with 15 men and 5 women, 85 implants). Two hundred and four implants remained at the end of the follow-up period. Among failed implants, 10 implants were in Group A (failure rate: 10/134 = 7·5%), whereas five implants were in Group B (failure rate: 5/85 = 5·9%). Sixty-six point seven per cent (10/15) of failed implants were placed in the distal anterior mandible, and 33·3% (5/15) were placed in the middle anterior mandible. Survival was also examined with respect to condition of the opposing arch. Patients wearing a maxillary removable partial denture had the highest implant failure rate (5/51 = 9·8%), whereas the failure rate of the maxillary complete denture group was only 5·7%. The most frequent need for maintenance was wear over patrix component of ERA or Hader clip (n = 56). Eight patients experienced connector fracture between ERA and Hader bar, and one experienced distal extension cantilever fracture. The implant-supported overdenture can be an effective and reliable alternative to the conventional complete mandibular denture. Fewer prosthetic complications were seen in overdentures retained with distal extension cantilever attachments.

Retention and leakage of implant-supported restorations luted with provisional cement: a pilot study.

Few data exist regarding cement failure load and marginal leakage of castings cemented to implant-supported abutments subjected to load and thermal cycling, especially with newer cements. This study evaluated the cement failure load and marginal leakage of castings cemented to Steri-Oss abutment/analog assemblies with one of seven luting protocols (n = 5). Protocols consisted of a zinc phosphate control, zinc phosphate with petroleum jelly, TempBond, TempBond NE, ImProv, ImProv with petroleum jelly and Provilink. Cemented castings were subjected to cyclic axial compression of 75 N for 100,000 cycles, 1000 thermal cycles (5-55 degrees C), and immersed 24 h in 0.5% basic fuchsin. The castings were then loaded in tension until cement failure. Cement failure load was analysed using anova and Fischer's PLSD (alpha = 0.05). Marginal leakage on the intaglio of the casting was scored with the unaided eye on a scale of 0-2, and analysed with Duncan's multiple range (alpha = 0.05). Similar groups are noted by superscript. Cement failure load (from lowest to highest): ImProv with petroleum jelly(a), TempBond(a), ImProv(a), Tempbond NE(a), Provilink(a), zinc phosphate with petroleum jelly(b), zinc phosphate(c) (P < 0.0001). Marginal leakage scores (from lowest to highest): ImProv(a), Provilink(a), ImProv with petroleum jelly(a), zinc phosphate(ab), zinc phosphate with petroleum jelly(ab), TempBond(bc), and TempBond NE(c) (P = 0.01). Addition of petroleum jelly to zinc phosphate lowered cement failure load without affecting marginal leakage. ImProv and Provilink demonstrated relatively low cement failure load, as well as lowest marginal leakage.

Use of pulsed field gel electrophoresis as an epidemiological tool for analysis of sporadic associated strains of Salmonella typhi isolated in Taiwan.

In order to characterize the subtypes of Salmonella typhi which cause sporadic disease in Taiwan, 55 isolates of Salm. typhi obtained from unrelated patients of sporadic cases during 1992-96 were subjected to chromosomal DNA digestion and pulsed field gel electrophoresis (PFGE). When DNAs of these 55 Salm. typhi strains were digested with XbaI, 41 PFGE patterns were observed. Strains sharing the same XbaI digestion pattern could not be further discriminated by PFGE analysis using SpeI and NotI as digestion enzymes. Thus, considerable genetic diversity exists among the Salm. typhi isolates. Although strains of the same patterns were mainly isolated during the same time, recirculation of certain infectious strains could be possible. When 12 antibiotics, i.e. ampicillin, trimethoprim/sulfamethoxazole, erythromycin, norfloxacin, tetracycline, sulphonamide, streptomycin, neomycin, chloramphenicol, kanamycin, cefoperazone and gentamycin were used to test the antibiotic susceptibility for these Salmonella isolates, only three antibiogram patterns were obtained and 49 of the 55 Salm. typhi isolates were found to belong to one pattern. Phage typing and plasmid profiles were also poor in discriminating these strains. Thus, PFGE alone may be used as a powerful tool for analysis of sporadic associated Salm. typhi strains.

A new technique for generating a computer-aided design and computer-integrated machining crown: case report.

A new technique for producing a Computer-Aided Design and Computer-Integrated Machining Ceramic Reconstruction crown is presented. After completion of the tooth preparation, an "optical" impression of the tooth was made with a charged couple device camera, and the electronic image was transferred to a computer screen. The "proposed" crown was electronically designed on the screen by the operator, and a proper prefabricated ceramic block was selected and used as milling material. A miniature milling machine then fabricated the crown from the ceramic block. The marginal adaptation and the contour of the crown were verified, and an external shading technique was utilized to improve the esthetics. The prepared tooth and crown were acid-etched, and the crown was cemented with a dual-curing composite luting agent. Once bonded in place, the occlusion was adjusted and the crown polished and finished. The advantage of this technique is that it eliminates the traditional laboratory casting procedure and corresponding laboratory fee while utilizing materials with superior physical properties for maximum strength and esthetics.

An alternative restorative method for regional odontodysplasia: case report.

A 5-year-old Caucasian male presented with early loss of multiple deciduous teeth. All the characteristics were consistent with the diagnosis of regional odontodysplasia (ROD). Significant initial findings included premature loss of multiple primary mandibular teeth and some malformed permanent teeth. The affected teeth showed hypoplastic enamel and dentin, short roots, and wide pulp chambers, and were localized in the mandibular dentition. Treatment objectives for this patient were to provide improved esthetics, restored chewing function, and space maintenance by the construction of a temporary prosthetic restoration. However, with limited tooth support and an unusual occlusal pattern, it is difficult to obtain satisfactory retention and esthetics with traditional prosthetic techniques. In this article we introduce an alternative method for fabricating a custom removable denture and discuss the prognosis of the malformed permanent dentition and further treatment plan.

Congenital coronary artery-cardiac chamber fistulae: a study of fourteen cases.

BACKGROUND: Congenital coronary artery fistula is a rare heart defect. Symptoms of the patient and characteristics of the fistula were investigated and the role of surgical treatment was evaluated. METHODS: Fourteen patients with congenital coronary artery fistulae were diagnosed here between January, 1983, and December, 1991. Only one patient was asymptomatic, but diagnosis was suspected from clinical presentation of a continuous murmur. In the 13 symptomatic patients, angina and exertional dyspnea were the most common symptoms. Congestive heart failure and subacute bacterial endocarditis were rare complications. Cardiac catheterization with selective coronary angiography was performed in all of these patients. The left anterior descending coronary artery was most commonly involved in this series. Findings, different from those in other literature, were the right coronary artery has more usually been reported. Fistulous communication was most often found in the pulmonary artery, right ventricle and right atrium. The mean ratio of pulmonary-to-systemic flow was 1.67 in 10 patients, and the shunt flow of another 4 accidentally diagnosed patients was trivial. Six patients, including all 4 patients, age < 20 years at diagnosis, underwent surgical correction; only 1 patient was not given an aid of cardiopulmonary bypass. RESULTS: The six patients who received surgical treatment, one died of pneumonia and respiratory failure and the other five patients had no evidence of residual fistula. All five were asymptomatic during a mean follow-up period of five years. The symptoms were slowly progressive, and functional status worsened in two who refused operation and in two high risk patients. In four patients with accidentally diagnosed small fistulae, the symptoms remained unchanged during six years of follow-up. CONCLUSIONS: The objective of surgical treatment was closure of the fistula tract without compromise of normal flow through the coronary artery. Surgical intervention was recommended for all symptomatic patients and asymptomatic young patients as well, to prevent the development of fistula-related complications.

Evaluating CAD-CAM generated ceramic veneers.

As the CAD-CAM technique has been expanded to include porcelain facings, of particular interest is adapting the veneer to the prepared surface. In a comparison of the gap dimension of CAD-CAM generated veneers to those produced in the laboratory, no statistically significant differences were detected.