Amalgam use and waste management by Pakistani dentists: an environmental perspective.

To assess amalgam use and waste management protocols practised by Pakistani dentists, a cross-sectional study was made of 239 dentists in Islamabad and Rawalpindi, recruited by convenience and cluster sampling. Amalgam was the most frequently used restorative material, with the choice dictated by patients' financial constraints. While 90.4% of dentists perceived amalgam as a health risk, only 46.4% considered it an environmental hazard. The majority disposed of amalgam waste in the trash, down the sink or as hospital waste. Very few (5.9%) had an amalgam separator installed in their dental office. Amalgam waste management protocols and mercury recycling should be introduced in Pakistan.

3D Nano-crystal Platinum for High-performance Neural Electrode.

A novel three-dimensional (3D) nano-crystal platinum (Pt) was introduced as a high-performance layer on the Pt substrate to provide extremely large surface, which significantly reduced electrical impedance by ˜ and increased the cathodic charge storage capacity (CSCc) up to ˜100 mC\textbullet(27 times) compared with that of bare Pt electrodes. In addition, the 3D nano-crystal Pt coating exhibited great mechanical and electrochemical stability as well as biocompatibility, which was critical and beneficial for effective neural stimulation/recording electrodes for practical applications.

Comparative evaluation of possible ocular photochemical toxicity of fluoroquinolones meant for ocular use in experimental models.

Fluoroquinolones (FQs) are extensively used in bacterial keratitis and other intraocular infections. Since eye is constantly exposed to light, incidence of ocular phototoxicity due to commonly used FQs is of great interest for their safe use. Phototoxicity of commonly used FQs (ciprofloxacin, lomefloxacin, pefloxacin, ofloxacin, sparfloxacin and gatifloxacin), has been evaluated by using HET-CAM-UV model (Photo Hen Egg Test-C Chorioallantoic Membrane model). This study was further extended by adding lomefloxacin dissolved in bovine vitreous (0.5 ml) on the chorioallantoic membrane (CAM). Using a standard scale, the phototoxic damage was assessed at different time intervals. Respective controls were kept in dark to distinguish the toxicity of the drugs per se. The results showed that the phototoxicity induced by lomefloxacin was very high followed by gatifloxacin and sparfloxacin and least for other drugs studied. Interestingly, lomefloxacin along with vitreous showed significantly low phototoxicity. This could be due to the antioxidant property of ascorbic acid present in the vitreous.

Maternal bearing down efforts--another fetal risk?

A prospective study of 12 unmedicated pregnant women in the second stage of labor was undertaken to assess the effects of bearing down efforts on brachial and popliteal blood pressure. Inferior vena cava compression, usually detected by reductions in mean and/or pulse pressure in the brachial artery, did not occur at any time, whether or not the uterus was displaced to the left. Abdominal aortic compression, suggested by popliteal pressure fall, was maintained into the second stage of labor, was aggravated when the women bore down, and was alleviated only when bearing down efforts ceased and the uterus was displaced to the left. Bearing down efforts are therefore yet another mechanism by which distal aortic and possibly uteroplacental blood flow can be prejudiced. Their avoidance can be advantageous to the fetus at risk.

Expression of p53 protein and ki-67 antigen in oral premalignant lesions and oral squamous cell carcinomas: An immunohistochemical study.

AIM: To study expression of p53 protein and ki-67 antigen in normal, non-dysplastic, dysplastic, premalignant and malignant lesions of the oral mucosa. MATERIALS AND METHODS: The standard immunohistochemical method along with MIB-1 and DO-7; DAKO antibodies was used to study the expression of p53 and ki-67 in paraffin-embedded tissue specimens. RESULTS: All samples studied showed positive staining for p53 and ki-67. Only one case each from leukoplakia and oral squamous cell carcinoma (OSCC) groups showed negative staining for ki-67. The staining was confined to basal layer in most of the cases except OSCC in which it was seen in all layers. The intensity of staining was moderate to intense. The percentage of p53-positive cells in normal mucosa was 15-25% which was increased to 95% in malignant mucosa. Statistical analysis revealed that the expression of p53 and ki-67 increases as normal oral mucosa becomes dysplastic and undergoes malignant transformation. CONCLUSION: These results emphasize the potential use of p53 protein and ki-67 antigen as markers of malignant transformation and carcinogenesis in oral premalignant lesions, conditions and OSCC, respectively; and in future they may serve as prognostic tools in the early detection of malignant transformation in oral premalignant lesions and conditions.

Reparative giant cell granuloma of the maxilla.

Giant cell reparative granuloma accounts for 1-7% of all benign lesions of the jaw. It often arises in the maxilla followed by mandible and affects children and young adults. It is usually a slow-growing lesion. The fast growing lesions are rare and despite the innocent histological appearance, has an aggressive behavior mimicking a malignant lesion. In the present report, the clinical features, diagnosis, and surgical treatment of an unusually large aggressive variety of reparative giant cell granuloma found in the cheek with extensions into maxilla, antrum, and infratemporal region in a 23-year-old female is described. The impact of delay in correct diagnosis on massive enlargement of the lesion, the importance of computed tomography-guided biopsy in the diagnosis of such inaccessible lesions, and the role of a general dentist in the early detection are also emphasized.

Inhibition of monoamine oxidase-A activity in rat brain by synthetic hydrazines: structure-activity relationship (SAR).

A series of hydrazine derivatives was synthesized in order to evaluate their monoamine oxidase A (MAO-A) inhibitory effects. MAO-A inhibitory activity of 4-tosyl benzoic acid carbohydrazide was quite potent, similarly to that of the corresponding 4-benzyloxy-benzoic acid carbohydrazide and its N-cyanoethylated derivative. Structural variations of these compounds, such as the replacement of the 4-substitutent, of the aromatic ring on which the carbohydrazide moiety is grafted, as well as cyclization of the hydrazide moiety in five- or six-membered rings caused either significant decline or complete loss of MAO inhibitory properties. The most active compound (4-tosyl benzoic acid carbohydrazide) was also subjected to the forced swim test, an animal model of depression, eliciting a marked reduction in immobility time in rats, without affecting the locomotor activity, implying that it possesses anti-depressant properties due to inhibition of MAO type-A.

Intrathecal morphine and blood pressure in preeclampsia.

Ten term parturients with moderate-severe preeclampsia received intrathecal morphine for labor analgesia. Significant reductions in blood pressure and heart rate, which were unrelated to analgesia, were observed.