Reliability of software-based assessment of paediatric preparations for preformed metal crowns in the simulation laboratory.

PURPOSE: Using software for assessment of restorative work on typodonts in the simulation laboratory may enhance the objective evaluation of student work. The study aimed to evaluate the inter-rater and intra-rater reliability using 3-D scans from the Planmeca Emerald™ intra-oral scanner with Romexis Compare® software for assessing preparations for preformed metal crowns (PMCs). METHODS: Three operators independently recorded 3-D scans and digitally measured the features of 30 PMC preparations on typodont primary teeth (# 75). Using Romexis Compare® software, preparations were measured from mesial, distal and occlusal aspects. Measurements were repeated after 2 weeks. The intraclass correlation coefficient (ICC) was used to measure the reliability of measurements between operators and within the one operator. RESULTS: For measuring the extent of tooth reduction, there was excellent intra-rater reliability for each operator (ICC 0.96-0.99). The highest inter-rater reliability was for measurements of the occlusal surface (0.946 and 0.956), followed by the mesial surface (0.852 and 0.862) and then the distal surface (0.746 and 0.724). CONCLUSION: This method was useful and reliable for measuring features of PMC preparation, but with some limitations. Improving the software to provide specific assistance tools would empower greater uptake of this method as an adjunct to traditional visual grading tool in paediatric dentistry preclinical teaching.

Liberação de componentes do extrato de Casearia sylvestris Swartz empregando membranas de látex natural como suporte / Analysis of Casearia sylvestris Swartz extract release from natural rubber latex membranes

A membrana de látex natural (NRL - Natural Rubber Latex), manipulada a partir do látex extraído da seringueira Hevea brasiliensis, tem apresentado grande potencial de aplicação no campo da biomedicina e dos biomateriais. Graças a sua biocompatibilidade e baixa taxa de rejeição, ela tem sido utilizada para próteses e enxertos, atuando como estimulante da angiogênese, adesão celular e barreira física a agentes infecciosos. Além dessas aplicações, as membranas são utilizadas como matriz de sistemas de liberação para avaliar o comportamento da liberação de fármacos e extratos de origem vegetal que apresentam propriedades medicinais. O sistema extrato-membrana tem como objeto de estudo uma nova abordagem dessas substâncias no tratamento de feridas visando à cicatrização e regeneração do tecido envolvido. Casearia sylvestris, conhecida popularmente como guaçatonga, pertence à família Salicaceae, conhecida na medicina popular pelos seus efeitos antiulcerogênicos, cicatrizantes, antiofídicos, anti-inflamatórios e antissépticos, propriedades já comprovadas por estudos. Trabalhos recentes demonstraram que a liberação controlada de fármacos e extratos utilizando membranas de látex natural é uma alternativa interessante e promissora para aplicações biomédicas. Assim, o objetivo deste projeto foi estudar a liberação do extrato de Casearia sylvestris incorporado à membrana de látex em soluções com diferentes valores de pH, com o propósito de estudar seu comportamento e sua liberação de forma controlada. A taxa de liberação do extrato do sistema extrato-membrana foi monitorada e analisada utilizando-se o método de espectroscopia ótica (UV). O pH básico age desestabilizando a membrana indicando que o polímero possui a habilidade de proteger o extrato de ser liberado em valores de pH ácidos, direcionando sua aplicação para o sítio de melhor absorção. Além disso, a liberação segue uma função bi-exponencial...

Natural Rubber Latex (NRL) membrane, made from latex extracted from the rubber tree Hevea brasiliensis, has shown great potential for use in the biomedicine and biomaterials area. Thanks to its biocompatibility and low rejection rate, it has been used for implants and grafts, acting as a stimulant of angiogenesis and cell adhesion and as a barrier against infectious agents. Besides these applications, the membranes are used as model release systems, to assess the release behavior of drugs and plant extracts that exhibit medicinal properties. The extract-membrane system represents a new approach to studying these substances, as aids to wound healing and tissue regeneration. Casearia sylvestris, popularly known as guaçatonga, belongs to the family Salicaceae, known in popular medicine for its anti-ulcerogenic, wound healing, anti-ophidian, antiinflammatory and antiseptic properties, all of which are proven by scientific studies. Recent studies have also shown that the controlled release of drugs and extracts from natural latex membranes is an interesting and promising process for biomedical applications. The objective of this project was thus to study the release of Casearia sylvestris extract incorporated into natural rubber membranes. The main concern was to study and optimize the controlled release of the extract at various pHs. The rate of release was monitored and analyzed by the method of optical spectroscopy (UV). Basic pHacts to destabilize the membrane, indicating that the polymer has the ability to protect the extract from being released at acidic pH values. The controlled release follows a bi-exponential function...

Recent insights on the medicinal chemistry of sickle cell disease.

Sickle Cell Disease (SCD) is one of the most prevalent hematological diseases in the world. SCD is a genetic disease characterized by punctual mutation that basis on the exchange of glutamic acid to valine in a beta chain of hemoglobin. In deoxygenated state, the interaction among the beta chains leads to hemoglobin polymerization carrying out to deformation of cytoskeleton structure of red blood cells to a sickle shape. Currently, the treatment is performed with the antineoplasic drug hydroxyurea. This review summarizes current knowledge about possible targets and the approaches to discover new compounds to treat the SCD symptoms. Drug design based on therapeutical application and molecular modifications strategies will be discussed.

Effects of l-arginine and N(G)-nitro-l-arginine methyl ester treatments on expression of neuronal nitric oxide synthase in the guinea-pig bladder after partial bladder outlet obstruction.

This study was aimed to examine the effects of pharmacological intervention on partial bladder outlet obstruction (PBOO) on expression of neuronal nitric oxide synthase (nNOS) and nitric oxide (NO) production and NO-related free radical damage using nitrotyrosine as a marker in the guinea-pig bladder. Partial urethral ligation was performed in young male guinea pigs which were then intraperitoneally administered l-arginine, N(G)-nitro-l-arginine methyl ester (l-NAME) or vehicle (saline) for 2 or 4 weeks. At the respective time points, the bladder was removed for nNOS immunohistochemistry, Western blot analysis, nitrotyrosine enzyme-linked immunosorbent assay test and NO colorimetric assay. In l-arginine-treated animals killed at 2 and 4 weeks, the total number of nNOS positive intramural neurons was significantly increased when compared with the corresponding control. Some neurons projected long extending fibers that were closely associated with the blood vessels. Furthermore, at 4 weeks, the nNOS protein content and NO production as reflected by the concentration of nitrite and nitrate were drastically elevated as measured by Western blot analysis and NO colorimetric assay, respectively. In l-NAME-treated group killed at 2 weeks, the number of nNOS positive neurons was markedly reduced when compared with the controls, but the change was not significant at 4 weeks. In the latter, however, the NO production as reflected by the concentration of nitrite and nitrate was markedly reduced; in addition, the nitrotyrosine concentration was significantly lower than the control. The present results support the role of NO in the pathophysiological changes following PBOO. We suggest the potential therapeutic application of l-arginine and l-NAME in PBOO; however, ultimately balancing the bidirectional effects of NO would be essential.

Methicillin-resistant Staphylococcus aureus endocarditis after transurethral prostatic resection.

We report the first case, to our knowledge, of methicillin-resistant Staphylococcus aureus endocarditis complicating transurethral prostatic resection for benign prostatic hyperplasia. The patient had been catheterized preoperatively because of urinary retention and, postoperatively, developed pyrexia with persistent methicillin-resistant S. aureus-positive blood cultures. The cause remained elusive, despite extensive investigations (including echocardiography), until he developed embolic phenomena pathognomonic of infective endocarditis 1 month into treatment with intravenous vancomycin.

Penile colour duplex ultrasonography as a screening tool for venogenic erectile dysfunction.

INTRODUCTION: Vasculogenic impotence is one of the major causes of erectile dysfunction. Cavernosometry and cavernosography is traditionally the gold standard for evaluation of venogenic impotence. However, it is invasive and there are potentially significant complications. Penile colour flow Doppler imaging (PCDI) is non-invasive and can be used to assess venous incompetence. MATERIALS AND METHODS: One hundred and sixty-eight patients were referred for PCDI assessment from March 1998 to February 2001. Forty-three of these also had cavernosogram and cavernosometry done and were included in the study. RESULTS: The sensitivity was 93.9%, the specificity was 90.0%, the accuracy was 93.0% with a negative predictive value of 81.8% and a positive predictive value of 96.9%. Kappa value of 0.81 was obtained, indicating excellent agreement between PCDI and cavernosogram and cavernometry. CONCLUSIONS: Penile colour flow Doppler imaging is accurate in the assessment of venogenic erectile dysfunction. It can replace cavernometry and cavernosogram as a screening tool. Cavernometry and cavernosogram should only be done in cases when PCDI suggests venogenic impotence, and when surgery is contemplated.

The role of BTA stat in clinical practice.

OBJECTIVE: BTA stat is a rapid, urine-based test for bladder cancer that detects human complement factor H related protein (HCFHrp) by monoclonal assay. This aim of this study was to assess the efficacy of BTA stat as a diagnostic tool for bladder cancer in symptomatic patients suspected of bladder cancer and in the surveillance of patients with a history of treated bladder cancer. PATIENTS AND METHODS: One hundred and six patients presenting with haematuria (gross or microscopic) or irritative bladder symptoms presenting to the urology outpatient clinic of Changi General Hospital and 13 patients under bladder cancer surveillance were recruited for this prospective study. All underwent voided urine cytology (VUC), urine culture, urine BTA stat, intravenous urogram and cystoscopy. Sensitivity, specificity, positive and negative predictive values were calculated for both tests. The stage and grade of bladder tumours detected were also correlated with both test results. Causes of false positives and specificity in different patient groups were analysed. RESULTS: BTA stat is more sensitive than VUC in detecting primary and recurrent bladder tumours (85% versus 55%) but is less specific (62.6% versus 100%). Urinary tract infections and urinary calculi accounted for 62% of false positives with BTA stat. When patients with positive urine cultures and benign IVU abnormalities were excluded, specificity of BTA stat improved (93.9% cf. 62.6%). BTA stat was highly specific (100%) and more sensitive than VUC (75% versus 25%) in detecting recurrent tumours in asymptomatic patients on cancer surveillance. CONCLUSION: A high false positive rate and low predictive value limits the use BTA stat in screening symptomatic patients. However, it has a role in cancer surveillance and in the screening of high-risk asymptomatic individuals. Further prospective trials should be performed to better assess its role in this respect.

A demographic profile of patients undergoing transurethral resection of the prostate for benign prostate hyperplasia and presenting in acute urinary retention.

OBJECTIVE: To evaluate, in a prospective study, the demographic profile of patients with benign prostate enlargement who presented in acute urinary retention (AUR). PATIENTS AND METHODS: The study comprised all patients admitted for transurethral resection of the prostate and categorised into two groups, i.e. those presenting in AUR or electively. The factors evaluated included the length of hospitalization, the patients' occupation, their duration of symptoms and reasons for not seeking treatment. RESULTS: There was no significant difference in the mean age and occupational status of the two groups but those in AUR had more complications and a longer hospital stay after surgery; 60% of these men had had their urinary symptoms for > 1 year. When asked why they did not seek treatment earlier, 35% reported fear of surgery, while 41% thought that their symptoms were a normal part of ageing. CONCLUSION: There is a need to raise the level of public awareness of benign prostatic enlargement because those who present with AUR incur excess morbidity and longer hospitalization that could otherwise be avoided through earlier treatment and elective surgery.

Dissociation and electrooxidation of primaquine diphosphate as an approach to the study of anti-chagas prodrugs mechanism of action.

This paper describes the voltammetric behavior of primaquine as a previous support to the further understanding of the delivery and action mechanisms of its respective synthesized prodrugs. There are few papers describing the drug behavior and most of the time no correlation between oxidation process and pH is done. Our results showed that primaquine oxidation is a one-step reaction involving two electrons with the charge transfer process being strongly pH-dependent in acid medium and pH-independent in a weak basic medium, with the neutral form being easily oxidized. This leads to the conclusion that quinoline nitrogen ring neutralization is a determinant step to the formation of the oxidized primaquine form. The existence of a relationship between the primaquine dissociation equilibrium and its electrooxidation process is shown. This work points the importance of voltammetric methodology as a tool for further studies on quantitative relationship studies between chemical structure and biological activity (QSAR) for electroactive drugs.

Holmium laser lithotripsy in the management of ureteric calculi.

INTRODUCTION: To evaluate the efficacy and safety of the holmium:YAG laser in retrograde ureteroscopic laser lithotripsy of ureteric calculi. METHODS: Three hundred and twenty-five patients (256 males and 69 females) with mean age of 45 years underwent 328 retrograde ureteroscopic laser lithotripsy as the primary therapy for ureteric calculi using semirigid mini-ureteroscopes and the holmium:YAG laser (Coherent, Palo Alto, California, USA). Four consultants and three registrars performed the procedures over a period of 31 months. RESULTS: The mean largest diameter of the calculi was 8.4 mm. The mean hospital stay was 1.8 days and the mean duration for the operation was 25 minutes. One hundred and twenty-two (37%) procedures were done as day surgery cases. Complete stone-free rates after single primary treatment using only the holmium:YAG laser were 75% and 91% at 4 weeks and 12 weeks of follow-up, respectively. Including 22 (7.6%) renal units which required additional procedures, the overall stone-free rate was 97%. Seventeen cases (5.2%) needed additional extracorporeal shock wave lithotripsy (ESWL) and 5 cases (1.5%) needed an additional repeat ureteroscopy and lithotripsy for complete stone clearance. Significant complications include 1 case of ureteric perforation. CONCLUSIONS: The holmium:YAG is a safe and effective intracorporeal lithotripter when deployed in a retrograde manner in conjunction with a mini-ureteroscope.

Retroperitoneal Castleman's disease in the perinephric space--imaging appearance: a case report and a review of the literature.

INTRODUCTION: Castleman's disease (CD) is a rare lymphoid tumour usually found in the mediastinum. Extrathoracic sites are uncommon. Its radiological findings may be similar to other retroperitoneal tumours, making diagnosis difficult. CLINICAL PICTURE: A 54-year-old female was found to have an incidental hypoechoic mass in the left posterior perinephric space on routine ultrasound. Abdominal computed tomography (CT) scan demonstrated an isodense mass which enhanced brightly with intravenous contrast. Angiogram confirmed a hypervascular mass. TREATMENT: The retroperitoneal mass was excised. OUTCOME: Histology revealed CD of hyaline-vascular type. CONCLUSION: CD should be considered in the differential diagnosis of a retroperitoneal mass, which demonstrates homogeneous and intense enhancement.

Use of patient-controlled analgesia in extracorporeal shockwave lithotripsy.

OBJECTIVE: To assess the advantages of patient-controlled analgesia (PCA)-in patients undergoing extracorporeal shockwave lithotripsy (ESWL) for urinary stones. PATIENTS AND METHODS: Between December 1995 and May 1996, a prospective study was carried out on 100 patients who underwent ESWL for urinary stones. The patients were assigned to two equal groups, one receiving PCA and the other pethidine (control). Patients in the PCA group self-administered varying doses of intravenous alfentanil according to their pain tolerance, while those in the control group were given a single bolus dose of 1 mg/kg body weight intravenous pethidine by the attending urologist before the start of the procedure. The stone site, maximum energy level achieved, number of shock waves given, duration of procedure, pain scores, patient tolerance and acceptance were recorded to assess the efficacy of PCA compared with analgesia controlled by the physician. RESULTS: Both groups were matched for age, body weight, stone location and number of shocks given. The PCA group received a mean of 1.03 mg alfentanil while the control group received a mean of 62.5 mg pethidine. The maximum discharge voltage of 16 kV was achieved in all but one patient (98%) in the PCA group whereas only 21 patients (42%) in the control group attained this level. The mean treatment duration was less in the PCA group (32.8 min) than in the control group (44.5 min), the mean pain score lower (3.76 and 4.62, respectively) and the incidence of nausea and vomiting much less (22% and 60%, respectively). In addition, all 21 patients in the PCA group who had received intravenous pethidine during previous sessions of ESWL chose PCA as the better form of analgesia. There were no adverse effects in the PCA group except for one patient whose arterial oxygen saturation decreased transiently. CONCLUSION: PCA enables the urologist to achieve better patient compliance through better pain control; its application has maximized the use of lithotripsy and the patients' acceptability for this form of analgesia is confirmed. We recommend that this form of analgesia be used for ESWL.

Prostate screening--the Singapore experience.

BACKGROUND: The prevalence of benign prostatic hyperplasia (BPH) is believed to be highly significant in most communities. In our country, many elderly men are unaware that something can be done for their troublesome urinary symptoms. The main objective of our prostate health screening was to educate our elderly male population that this is an abnormality, for which treatment is readily available. At the same time, we attempted to determine the prevalence of BPH, to detect possible prostate cancer, and to derive normal prostate specific antigen (PSA) and uroflow values for our population. METHODS: Over an eight-day period in April 1994, 799 men above the age of 50 years volunteered to participate in a free prostate screening exercise held at our hospital. The parameters assessed were PSA level, American Urological Association (AUA) symptom score, uroflowmetry, and digital rectal examination (DRE) of the prostate. RESULTS: Elevated PSA levels of more than 4 micrograms/L were detected in 105 men (13.1%). Of these, 23 men (2.9%) had PSA values above 10 micrograms/L. Abnormal AUA symptom scores of more than eight (moderate and severe categories) were noted in 540 men (67.6%). Clinically enlarged prostate glands of more than 20 g on DRE were noted in 80 men (10.0%), and abnormal DRE findings were detected in 48 men (6.01%). Impaired maximal uroflow rates of less than 10 mL/s were recorded in 224 men (39%), while another 167 men (29.1%) had maximal uroflow values in the equivocal zone (between 10 to 15 mL/s). The reference PSA levels at the 5th percentile, 10th percentile, median, mean, 90th percentile and 95th percentile were 0.38, 0.47, 1.05, 1.57, 3.27 and 4.25 micrograms/L, respectively. The age-specific PSA values were 3.51, 3.78 and 6.02 micrograms/L in the 50 to 59, 60 to 69, and 70 to 79 years age groups, respectively, and the reference mean maximal uroflow rates was 14.8 mL/s. CONCLUSIONS: Although controversial, our experience with prostate screening was generally positive. As far as our population is concerned, the free prostate screening exercise generated publicity, and succeeded in enhancing public awareness for better prostate health.

Necrotising fasciitis: an entity revisited.

Necrotising fasciitis is a disease that still carries a high morbidity and mortality despite our better understanding and advances in treatment since 1924 when Meleney first studied it. In our Department of Orthopaedics, this condition appears to be on the increase, and we therefore felt this entity deserved a restudy. Since 1985, 15 cases were seen, of which 10 were encountered in 1989. There were no recorded case prior to 1985. Our initial results show that the background and outcome parallel that of previous authors. Most were elderly with some form of underlying chronic disease. The duration from symptom onset to presentation was short, with many being in a state of septicaemia at the time of admission with fever, metabolic acidosis and marked leucocytosis. Repeated desloughings were common, and four ended up with some form of limb amputation. As with Meleney's study, the consistent pathogen cultured was B-haemolytic streptococcus. Our recommendation is that we should be more aware of this entity in view of its fulminant course, with early and aggressive surgical intervention being the keystone to management.

The alternate respiratory pathway of Candida albicans.

Candida albicans contains a cryptic cyanide and antimycin A insensitive respiratory system. This alternate oxidase was found (i) at all growth rates from mu = 0.05 to 0.26 in a chemostat culture and (ii) in both mycelial and yeast forms of the organism. Neither chloramphenicol nor cycloheximide prevented the expression of the alternate oxidase. Salicylhydroxamic acid was a potent inhibitor of the cyanide insensitive respiration. The respiration of mitochondria grown in the presence of antimycin A was not inhibited by cyanide or antimycin A but was inhibited by salicylhydroxamic acid.