Correlation between dental arch location and clinical success rate of total etch and self-etch adhesives in ClassV composite restorations.

Flexure at the tooth cervix might render the restored Class V lesions to degradation. In this clinical trial a total of 76 carious cervical lesions in both arch were restored using Prime & Bond NT and Clearfil SE Bond adhesives, along with Clearfil APX composite resin. Retention of restoration, marginal discoloration and postoperative sensitivity were evaluated during a one year period. The overall clinical success rate was 89.5%, while no significant difference (p > 0.05) was found regarding postoperative sensitivity or marginal discoloration between two adhesives. Retention loss was associated only with self-etch adhesives. No association was found between clinical success and dental arch location.

Estimation of Dosimetric Parameters based on KNR and KNCSF Correction Factors for Small Field Radiation Therapy at 6 and 18 MV Linac Energies using Monte Carlo Simulation Methods.

BACKGROUND: Estimating dosimetric parameters for small fields under non-reference conditions leads to significant errors if done based on conventional protocols used for large fields in reference conditions. Hence, further correction factors have been introduced to take into account the influence of spectral quality changes when various detectors are used in non-reference conditions at different depths and field sizes. OBJECTIVE: Determining correction factors (KNR and KNCSF) recommended recently for small field dosimetry formalism by American Association of Physicists in Medicine (AAPM) for different detectors at 6 and 18 MV photon beams. METHODS: EGSnrc Monte Carlo code was used to calculate the doses measured with different detectors located in a slab phantom and the recommended KNR and KNCSF correction factors for various circular small field sizes ranging from 5-30 mm diameters. KNR and KNCSF correction factors were determined for different active detectors (a pinpoint chamber, EDP-20 and EDP-10 diodes) in a homogeneous phantom irradiated to 6 and 18 MV photon beams of a Varian linac (2100C/D). RESULTS: KNR correction factor estimated for the highest small circular field size of 30 mm diameter for the pinpoint chamber, EDP-20 and EDP-10 diodes were 0.993, 1.020 and 1.054; and 0.992, 1.054 and 1.005 for the 6 and 18 MV beams, respectively. The KNCSF correction factor estimated for the lowest circular field size of 5 mm for the pinpoint chamber, EDP-20 and EDP-10 diodes were 0.994, 1.023, and 1.040; and 1.000, 1.014, and 1.022 for the 6 and 18 MV photon beams, respectively. CONCLUSION: Comparing the results obtained for the detectors used in this study reveals that the unshielded diodes (EDP-20 and EDP-10) can confidently be recommended for small field dosimetry as their correction factors (KNR and KNCSF) was close to 1.0 for all small field sizes investigated and are mainly independent from the electron beam spot size.

Assessment of Computer Regulation Thermography (CRT) as a Complemetrary Diagnostic tool for Breast Cancer Patient.

BACKGROUND: Breast cancer is the most common type of cancer in women demanding accurate diagnosis to take remedial measures to treat. OBJECTIVE: Comparing the diagnostic capability of the computer regulation thermography (CRT), as a novel and safe diagnostic procedure, with common methods including sonography, mammography and clinical examinations for diagnosing breast cancer in suspicious patients against pathology as the gold standard. MATERIAL AND METHODS: In this prospective clinical trial study, out of 97 referred patients, 44 meeting the inclusion criteria were selected. The selected patients were subjected to mammography, sonography, CRT and clinical examinations. Then, the patients showing suspicious symptoms of breast cancer underwent pathological examinations. RESULTS: CRT indicated a higher specificity compared to mammography and sonography (78.9% vs. 71.4% and 47.0%, respectively). However, CRT sensitivity was lower than those of mammography, sonography and clinical examination (52% vs. 70.6%, 82.4% and 84.0%). Furthermore, CRT accuracy was lower than mammography, sonography and clinical examination (63.6% vs. 70.9%, 64.7% and 88.6%). While CRT positive prediction value (PPV) was higher than those of mammography and sonography, it was lower than that of clinical examination (76.5% vs. 75%, 60.9% and 95.5%). The negative prediction value (NPV) of CRT was less than all other modalities (55.5% vs. 66.7%, 72.7% and 81.8% for the clinical examination, mammography and sonography, respectively). CONCLUSION: Although CRT with a lower sensitivity and higher specificity, cannot be recommended to be used as a definitive diagnostic tool for breast cancer patients, it can be used as a complementary method with other methods to increase the diagnostic accuracy of suspicious patients.

Evaluating morphology and mechanical properties of glass-reinforced natural hydroxyapatite composites.

Hydroxyapatite has been used in a wide variety of biomedical applications and it can be produced from natural resources such as bovine bone. This material does not have acceptable mechanical properties by itself. In the present work, hydroxyapatite composites with different weight percentages of sodalime glass were made and sintered at different temperatures (800-1200°C). Eventually the properties such as density, micro hardness, compressive strength and wear of specimens were evaluated. Specific percentages of glass additive increased the density and hardness of specimens due to increasing the sintering temperature. The hardness and density of specimens were decreased with higher percentage of glass additive. Moreover, the results of compressive test showed that increasing the glass addition increases the compressive performance. Furthermore, the SEM micrographs on worn specimens showed that the mechanism of wear was abrasive.

Effect of Gold Nanoparticles on Prostate Dose Distribution under Ir-192 Internal and 18 MV External Radiotherapy Procedures Using Gel Dosimetry and Monte Carlo Method.

BACKGROUND: Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions. OBJECTIVE: The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC) method for studying the effect of gold nanoparticles (GNPs) in prostate dose distributions under the internal Ir-192 and external 18MV radiotherapy practices. METHOD: A Plexiglas phantom was made representing human pelvis. The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method. Then, a new formulation of MAGIC-f gel was synthesized. The fabricated gel was poured in the tubes located at the prostate (with and without the GNPs) and bladder locations of the phantom. The phantom was irradiated to an Ir-192 source and 18 MV beam of a Varian linac separately based on common radiotherapy procedures used for prostate cancer. After 24 hours, the irradiated gels were read using a Siemens 1.5 Tesla MRI scanner. The absolute doses at the reference points and isodose curves resulted from the experimental measurement of the gels and MC simulations following the internal and external radiotherapy practices were compared. RESULTS: The mean absorbed doses measured with the gel in the presence of the GNPs in prostate were 15% and 8 % higher than the corresponding values without the GNPs under the internal and external radiation therapies, respectively. MC simulations also indicated a dose increase of 14 % and 7 % due to presence of the GNPs, for the same experimental internal and external radiotherapy practices, respectively. CONCLUSION: There was a good agreement between the dose enhancement factors (DEFs) estimated with MC simulations and experiment gel measurements due to the GNPs. The results indicated that the polymer gel dosimetry method as developed and used in this study, can be recommended as a reliable method for investigating the DEF of GNPs in internal and external radiotherapy practices.

Flow cytometric DNA analysis and chromosomal aberrations in malignant glioblastomas.

In this study we combined flow cytometry with fluorescence in situ hybridization to detect numerical aberrations in chromosomes. Fifty-nine human malignant gliomas were examined by flow cytometry for DNA-content and cell cycle analysis and for numerical aberrations of chromosome 1 by in situ hybridization using a chromosome specific centromere probe. Of the gliomas analysed, 42% were diploid and 58% showed aneuploid tumour cell populations. The DNA index was heterogeneous ranging from 1.0 to 2.3. The S-phase analysis showed proliferation activity from a very low range of 0.7% up to 17.0%. In general, diploid gliomas exhibited a lower S-phase activity than aneuploid gliomas. Of the aneuploid gliomas, 15% showed a peridiploid pattern with a DNA index mean of 1.1. In these peridiploid tumours a trisomy of chromosome 1 could be detected by fluorescence in situ hybridization (FISH). The frequency of trisomic chromosome 1 in malignant gliomas reflects a very slight increase in DNA index from diploid to peridiploid (DNA index 1.1). Comparison of chromosome numbers and DNA content gave good correlation. Also important, the results reflects the cell cycle, specifically the extent of S-phase activity. In general, cell proliferation of diploid and peridiploid gliomas is much less than in higher aneuploid gliomas. The analysis of DNA content may thus yield results with respect to the biological behaviour of tumours in general.

Effects of GABAergic drugs on physostigmine-induced yawning in rats.

In the present work the effects of GABA agonists and antagonists on yawning induced by physostigmine have been studied. Intraperitoneally (IP) injection of physostigmine (0.05-0.3 mg/kg) induced dose-related yawning in rats. The maximum yawning response was observed with 0.2 mg/kg of the drug. The GABA agonists muscimol (1-4 mg/kg) and baclofen (0.125-1 mg/kg) decreased yawning induced by physostigmine (0.2 mg/kg) dose dependently. Combination of both GABA agonists elicited greater inhibition of yawning. The GABA-A antagonists bicuculline or picrotoxin but not the GABA-B antagonist phaclofen reduced the inhibitory response induced by muscimol, whereas phaclofen but not bicuculline or picrotoxin reduced baclofen's inhibitory effect. Administration of bicuculline, picrotoxin or phaclofen also decreased the yawning induced by physostigmine. However, when the GABA-A and GABA-B antagonists were employed in combination, the inhibitory responses of both drugs were lost. It is concluded that GABA-A and/or GABA-B receptor stimulation may inhibit physostigmine-induced yawning.

New valves--new dangers? 22 valves (38 probes) designed in the 'nineties in ultralong-term tests (365 days)'.

UNLABELLED: In the nineties, more than 30 valves have been launched, most are "clones", but some introduce new concepts (Diamond, SiphonGuard, PaediGAV). Of the 22 designs we tested, 20 have no previous tests and 3 are low-cost valves from Mexico (Dewimed), Zimbabwe (Harare-shunt) and England (Nottingham Shunt). 27 were tested using non-stop-perfusions for 365 days, 8 for 168-294 and 3 for 2 days. RESULTS: Ranking of the mean relative deviation: adjustable valves 19%, gravitational 34%, simple ball 51%, diaphragm 73%, distal slit 74% and autoregulating valves 121%. Ranking of physiological flow properties: gravitational > Equiflow > autoregulating > adjustable > ball > diaphragm > distal slit. SAFETY: The Equiflow were highly susceptible to external pressure. CONCLUSION: Most valves designed in the nineties showed inaccuracy, long-term-drifts, safety deficits and hydraulic mismanagement similar to more than 400 previously tested probes. With regard to accuracy and drift the ball designs were superior, but simple and adjustable ball valves are at risk of overdrainage. The gravitational ball valves (Cordis GCA, Miethke valves) showed the closest relation to physiological flow requirements.

A new way for surgical education--development and evaluation of a computer-based training module.

Computer-based training (CBT) programs teach the material of a specific field and at the same time offer various ways of objectively assessing the knowledge gained. The interactive use of multi-media components such as text, graphics, animation, sound, digital slide shows, and videos as well as quizzes can theoretically facilitate the learning process. The aim of this study was the development and evaluation of a CBT-program by surgeons for student training. Using SuperCard, a teaching module for Distal Radius Fracture (DRF) was developed, which contains detailed clinical information. Video clips and vivid animations combine theoretical knowledge with practical experience. Fourth-year medical students (n = 103) were tested after using the module for 90 min. Other students (n = 47) served as the control group. In a 90 min lecture, DRF was discussed. CBT gained in all evaluated criteria (distinctiveness, detailed description, presentation of materials, structure, motivation for learning, time saved learning and memory retention) 15-20% better scores than the lecture. Although 82% of the students stated that their experience with computers was limited or insufficient, 100% found the use of CBT systems useful in student teaching. Most of them suggested the use of such programs as a method of exam preparation/self study (90%) or as a supplement to a lecture (40%). Based on these evaluations, CBT modules are an appropriate future teaching and learning system that is well accepted. In conclusion, the results of this study show that CBT-programs could be a valuable supplement to medical education. In addition, further development of CBT-programs and their use as information systems for surgical residency programs at universities can be suggested.

[Computer-based training--a new method in surgical education and continuing education]. / Computer-basiertes Training--Ein neuer Weg der chirurgischen Aus- und Weiterbildung.

Computer-based training (CBT) programs teach the material of a specific field and at the same time offer various ways of objectively checking the knowledge gained. The interactive use of multimedia components, such as text, graphics, animation, sound, digital slide shows, videos and quizzes, facilitates the learning process. The aim of this study was the development and evaluation of a CBT program for use by surgeons teaching students. Using SuperCard, a teaching module for distal radius fracture (DRF) was developed, containing detailed clinical information. Video clips and vivid animation combine theoretical knowledge with practical experience. Fourth-year medical students (n = 103) were tested after using the module for 90 min. Other students (n = 47) served as the control group. In a 90-min lecture, DRF was discussed. In all evaluated criteria (distinctness, detailed description, presentation of materials, structure, motivation to learn, time saved while learning and memory retention), CBT gained 15-20% better scores than the lecture. Although 87% of the students stated that their experience with computers was limited or insufficient, 100% found the use of CBT systems helpful in student teaching. Most of them suggested the use of such programs as a exam preparation/self study method (90%) or as a supplement to a lecture (40%). Based on these evaluations, it is clear that CBT modules are an appropriate future teaching and learning system that will be well accepted. In conclusion, CBT programs should be integrated into medical education as a valuable supplement. With this aim, CBT systems should be developed and used at universities as an information system for the surgical residency program.

Relation between Actinomycosis and Histopathological and Clinical Features of the Palatine Tonsils: An Iranian Experience.

BACKGROUND: Actinomycosis of the tonsils has been reported in a variable percentage of tonsil specimens by other authors. This study determines the incidence of actinomyces in the palatine tonsil and evaluates the clinical diagnoses and histopathological features of tonsillectomy specimens. METHODS: In a retrospective study, 204 patients who had undergone tonsillectomy for recurrent tonsillitis (group A) and for sleep apnea without a history of recurrent tonsillitis (group B) were enrolled. RESULTS: The prevalence rate was significantly higher in the adult compared with the pediatric population. The prevalence of tonsillar actinomycetes colonization was higher in patients who had undergone tonsillectomy for recurrent tonsillitis (43.9%) than in patients who had undergone tonsillectomy for obstructive sleep apnea (26.3%). The prevalence did not differ by sex of patient. Histopathological analysis of resected tonsils did not show active tissue infection. There was a statistically significant relationship between the presence of actinomycosis and age, with a greater occurrence of actinomycosis in adult patients. CONCLUSION: Although actinomyces colonization is more prevalent in patients with recurrent tonsillitis than sleepdisordered breathing, but the presence of actinomyces does not indicate any active disease.

Development and characterization of a novel PRESAGE formulation for radiotherapy applications.

A novel water equivalent formulation of PRESAGE dosimeter more suitable for radiotherapy applications has been introduced and its radiological water equivalency has been investigated. Furthermore, its radiological properties have been compared with an existing PRESAGE formulation over an energy range from 10 to 20 MeV. Monte Carlo simulation method has been implemented to determine and compare depth dose profiles in both of the PRESAGE formulations at two different photon energies (140 KV(P) and 6 MV). The results show that our proposed PRESAGE formulation is more water equivalent than its known formulation especially for low photon energy beams.

A basic dosimetric study of PRESAGE: the effect of different amounts of fabricating components on the sensitivity and stability of the dosimeter.

Over the past few years there has been much interest in the development of three-dimensional dosimeters to determine the complex absorbed dose distribution in modern radiotherapy techniques such as IMRT and IGRT. In routine methods used for three-dimensional dosimetry, polymer gels are commonly used. Recently, a novel transparent polymer dosimeter, known as PRESAGE, has been introduced in which a radiochromic color change is observed upon radiation. PRESAGE has some advantages over usual polymer gel dosimeters. It has been noted that the sensitivity of PRESAGE can be changed when different amounts of the components are used for its fabrication. This study has focused on the assessment of dosimetric characteristics of PRESAGE for various amounts of components in its formulation. To achieve this, PRESAGE dosimeters were fabricated using various amounts of their constituting components. Then the dosimeters were irradiated to (60)Co gamma photons for a range of radiation doses from 0 to 50 Gy. Consequently, the light absorption changes of the dosimeters were measured by a spectrophotometer at different post-irradiation time periods. It was generally observed that as the concentration of the radical initiator is increased, the PRESAGE dosimeter sensitivity is increased while its stability is decreased. Furthermore, it was noted that with the high concentration of the radical initiator and leuco dye, the sensitivity of PRESAGE is decreased.

Histopathological screening of tonsillectomy and/or adenoidectomy specimens: a report from southern Iran.

BACKGROUND: The need for pathologic examination of all tonsillectomy and/or adenoidectomy (T&A) specimens is controversial. Microscopic pathologic examination of these specimens is costly, but neglecting this step may miss diagnoses of significant diseases, especially malignancies. This study was designed to determine the rate of unexpected malignancies among patients who underwent T&A. METHODS: All patients who underwent T&A at Shiraz University of Medical Sciences between February 2004 and February 2008 were included in a prospective study. Gross and microscopic pathologic examinations were done on all the specimens. The charts of the patients with significant pathological finding were reviewed. Information about pre-operative signs, symptoms, and risk factors were used to verify unexpected pathologic findings. RESULTS: A total of 5058 patients were included. The age distribution was 10 months to 92 years (mean 14.0 years). There were 2498 males (49.4) and 2560 females (50.6%). Significant pathological findings were detected in 54 patients (1%). One unexpected malignancy (0.019%) was found in an adult patient. No unexpected malignancies were found in pediatric patients. CONCLUSIONS: All T&A specimens in the adult population should be sent for microscopic pathological examination. Also specimens of nonroutine T&A in children (with positive findings in the medical history or on physical examination) should be sent for microscopic pathological examination. In children without positive findings in their history or on physical examination, gross pathological evaluation of routine T&A specimens by a pathologist is sufficient.

The effect of pre spring spray to reduce of citrus important pests.

The importance of pre spring spray against citrus aphids, Pulvinaria aurantii Cockerell and Panonychus citri McGregor that are the most important pest of citrus during spring was tested. In this research, 150 trees ten years old sweet orange (Thomson navel on Citrus aurantium (root stocks)) in a citrus orchard approximately three hectares sampled. The experiment was laid out in a totally randomized (one-way) design replicated five times. According to the results, the pre spring spray do not effect on population density of citrus aphids and P. aurantii during March, April, May and June. However, the P. citri population decreased. Therefore, it seems the pre spring spray in citrus orchards is not necessary, but if P. citri is observed, the pre spring spray should be recommended.

[Surgical treatment of carpal tunnel syndrome in pregnancy: results from 314 cases]. / Die operative Behandlung des Karpaltunnelsyndroms in der Schwangerschaft. Erfahrungsbericht anhand von 314 Fällen.

A total of 314 hands of patients suffering from carpal tunnel syndrome (CTS) in pregnancy or puerperium were treated by carpal tunnel release. In 53% of these cases, other members of the family were also affected, usually the mother. Ninety-seven patients were operated upon at both hands. One hundred thirty-three operations were performed during pregnancy, mostly in the last trimester, and 181 during puerperium. In four patients, the operation was performed on both hands simultaneously. There were also 12 cases of associated De Quervain's tenosynovitis and ten trigger fingers. Severe night pain and/or permanent hypoesthesia was experienced by 93% of the patients. All patients were operated on with local anesthesia and in a bloodless field. The distal motor latency was 7 +/- 1.5 ms in cases with hypoesthesia and 4.9 +/- 1.75 ms without sensory loss. Of the patients, 98% reported good or excellent results of the operation during pregnancy via questionnaires. Since symptoms are often very severe in pregnancy and puerperium and the operation is well-tolerated by pregnant women and without risk to either mother or child, we recommend surgery, especially when sensory loss is present and motor latency is more than 5 ms.

Involvement of GABAB receptors in the antinociception induced by baclofen in the formalin test.

1. The effect of GABA receptor antagonists on baclofen-induced antinociception was examined in rats using the formalin test. Intraperitoneal (IP) administration of different doses of baclofen (2.5-10 mg kg-1) to rats induced antinociception in both phases of the test. 2. The response was dose-dependent and the maximum response was observed with 10 mg kg-1 of the drug. Intracerebroventricular (ICV) injection of baclofen (0.5-20 micrograms/rat) also induced dose-dependent antinociception in the second phase of the formalin test. 3. The GABAB antagonist, phaclofen (1 mg kg-1, IP) but not the GABAA antagonists picrotoxin (1 mg kg-1, IP) and bicuculline (1.5 mg kg-1, IP), decreased the antinociception induced by both ICV and IP administration of baclofen. 4. It is concluded that baclofen antinociception in the formalin test is mediated through GABAB receptor activation.

The scientific history of hydrocephalus and its treatment.

Hydrocephalus cases were regularly described by Hippocrates, Galen, and early and medieval Arabian physicians, who believed that this disease was caused by an extracerebral accumulation of water. Operative procedures used in ancient times are neither proven by skull findings today nor clearly reported in the literature. Evacuation of superficial intracranial fluid in hydrocephalic children was first described in detail in the tenth century by Abulkassim Al Zahrawi. In 1744, LeCat published findings on a ventricular puncture. Effective therapy required aseptic surgery as well as pathophysiological knowledge--both unavailable before the late nineteenth century. In 1881, a few years after the landmark study of Key and Retzius, Wernicke inaugurated sterile ventricular puncture and external CSF drainage. These were followed in 1891 by serial lumbar punctures (Quincke) and, in 1893, by the first permanent ventriculo-subarachnoid-subgaleal shunt (Mikulicz), which was simultaneously a ventriculostomy and a drainage into an extrathecal low pressure compartment. Between 1898 and 1925, lumboperitoneal, and ventriculoperitoneal, -venous, -pleural, and -ureteral shunts were invented, but these had a high failure rate due to insufficient implant materials in most cases. Ventriculostomy without implants (Anton 1908), with implants, and plexus coagulation initially had a very high operative mortality and were seldom successful in the long term, but gradually improved over the next decades. In 1949, Nulsen and Spitz implanted a shunt successfully into the caval vein with a ball valve. Between 1955 and 1960, four independent groups invented distal slit, proximal slit, and diaphragm valves almost simultaneously. Around 1960, the combined invention of artificial valves and silicone led to a worldwide therapeutic breakthrough. After the first generation of simple differential pressure valves, which are unable to drain physiologically in all body positions, a second generation of adjustable, autoregulating, antisiphon, and gravitational valves was developed, but their use is limited due to economical restrictions and still unsolved technical problems. At the moment, at least 127 different designs are available, with historical models and prototypes bringing the number to 190 valves, but most of these are only clones. In the 1990s, there has been a renaissance of endoscopic ventriculostomy, which is widely accepted as the method of first choice in adult patients with aquired or late-onset, occlusive hydrocephalus; in other cases the preference remains controversial. Both new methods, the second generation of valves as well as ventriculostomy, show massive deficits in evaluation. There is only one randomized study and no long-term evaluation.

A convenient spectrophotometric method for measuring the kinetic parameters of glyceryl-ether monooxygenase (EC 1.14.16.5).

Details of a direct spectrophotometric method for assaying glyceryl-ether monooxygenase activity are described. The assay has several advantages over previous methods including the convenient determination of the kinetic parameters of lipid substrates and tetrahydropterin cofactors with acceptable accuracy. The apparent Km and Vmax values have been measured for 6-methyl- and 6,7-dimethyl-5,6,7,8-tetrahydropterins and 6R-tetrahydrobiopterin as well as twelve lipid ethers including lyso-PAF (platelet activating factor), and the V/K values are a better index for comparing substrate efficiencies. The monooxygenase activities of a variety of assorted lipids are also compared with RS-batyl alcohol, some of which are weak inhibitors. The effects on monooxygenase activity by various concentrations of six detergents are compared and showed that Mega-10 is the most satisfactory for solubilising alkyl ether substrates at low concentrations (ca. 0.08%) of detergent. The syntheses of a variety of ether lipids used in this work, together with their 1H-NMR and IR spectra, are described.