Periodontal attachment loss in an untreated isolated population of Brazil

Background: The aim of this study was to assess the prevalence, extent, and severity of clinical attachment loss (CAL) and to investigate the association of demographic, socioeconomic, and behavioral risk indicators with CAL in an untreated isolated population in Brazil. Methods: All subjects aged >= 12 years were identified by a census. Participants were submitted to a full-mouth clinical examination of six sites per tooth and were interviewed using a structured, written questionnaire. Results: Among the 214 subjects who were interviewed and examined clinically, CAL >= 5 mm in at least one site was observed in 8% of the 12- to 19-year-olds and in all dentate subjects >= 50 years of age; the age-dependent prevalence of CAL >= 7 mm in at least one site ranged from 5% among 12- to 19-year-olds to 83% among subjects >= 50 years old. Multivariate analysis identified plaque (odds ratio [OR] = 2.8), supragingival calculus (OR = 2.9 to 10.6), age >= 30 years (OR = 11.4), and smoking (OR = 2.4) as risk indicators for CAL >= 5 mm and smoking (OR = 8.2) as a risk indicator for CAL >= 7 mm. Conclusions: CAL is highly prevalent in this isolated population. The high occurrence of CAL in young age groups and the confirmation of traditional risk indicators for CAL in this study suggest that other factors, such as host susceptibility, may be needed to explain the high levels of CAL found. Age and behavioral factors were risk indicators associated significantly with the CAL found in this population and may be useful indicators of high-risk subjects for periodontal diseases.

Tooth loss prevalence and risk indicators in an isolated population of Brazil

Objective. The aim of this study was to assess the prevalence, extent, and risk indicators of tooth loss in an isolated population of Brazil. Material and methods. Two-hundred-and-forty-two subjects, ranging in age from 14 to 82 years (mean 36.2 years), were identified by census in an isolated population of Brazil. All consenting subjects received a full-mouth clinical (DFT index and information about missing teeth) and periodontal examination of 6 sites per tooth. Furthermore, they were interviewed using a structured written questionnaire in order to gather information about demographic, environmental, and biological variables. Results. Of the 200 subjects (80% response rate), 19 (9.5%) were edentulous, 90% had lost at least one tooth, and 39% had lost more than 8 teeth. The mean number of teeth lost was 9.5 (95% CI = 8.2-10.8). First mandibular molars were the most commonly missing teeth. In a multiple logistic regression analysis based on a theoretical hierarchical model of tooth loss, having more than 8 teeth lost was strongly associated with adult age (OR = 18.3-17.3, 95% CIs = 4.8-69.7 and 4.0-75.1) and female gender (OR = 5.9, 95% CI = 1.9-18.2) in the final model. Conclusions. Tooth loss was highly prevalent and extensive in this isolated population. Demographic and behavioral factors played an important role in tooth loss prevalence in this population.

Risk indicators for increased probing depth in an isolated population in Brazil

Background: The aim of this study was to assess the prevalence, extent, and severity of probing depth (PD) and to investigate the associations between demographic, socioeconomic, and behavioral risk indicators and PD in a periodontally untreated and isolated population in Brazil. Methods: The target population consisted of all individuals aged >= 12 years as identified by a census. Consenting participants were submitted to a full-mouth clinical examination of six sites per tooth and were interviewed using a structured written questionnaire. Results: Among the 214 subjects who were interviewed and clinically examined, PD >= 4 mm was observed in 54% to 83% of the subjects, depending on age, whereas the age-dependent prevalence of PD :6 mm ranged from 5% among 12- to 19-year-olds to 50% among 40- to 49-year-olds, decreasing to 40% among subjects >= 50 years of age. Multivariate analyses identified supragingival calculus (odds ratio [OR] = 5.4 to 10.3; 95% confidence intervals [CIs]: 2.5 to 11.6 and 4.0 to 26.2 for 20% to 50% and > 50% of the sites, respectively) as a risk indicator for PD A mm, whereas age :40 years (OR = 9.0; 95% CI: 1.7 to 48.5), being a moderate/heavy smoker (OR = 3.7; 95% CI: 1.4 to 10. 1), and having supragingival calculus in 20% to 50% of sites (OR = 6.8; 95% CI: 1.4 to 32.4) or in >50% of sites (OR = 15.3; 95% CI: 3.2 to 73.6) were risk indicators for PD >= 6 mm. Having undergone urgency dental treatment was a protective factor for PD A and >= 6 mm (OR = 0.4; 95% CI: 0.2 to 0.8). Conclusions: Increased PD is highly prevalent in this isolated population. Behavioral factors played a significant role as risk indicators for increased PD in this isolated population.

Bite force, electromyography, and mandible mobility during the 6-month period after surgical treatment for isolated fractures of the zygomatico-orbital complex

Objective. The aim of this study was to identify the behavior of masticatory muscles after fractures of the zygomatico-orbital complex (ZOC) and subsequent surgical treatment, by using analyses of bite force, electromyography (EMG), and mandible mobility during a 6-month period after surgery. Study design. Five patients with fractured ZOCs treated surgically by using an intraoral approach and fixation exclusively in the region of the zygomaticomaxillary buttress were evaluated. The control group included 12 other patients. During postoperative follow-up, bite force, mandible mobility, and EMG analysis of the masticatory muscles were evaluated. Results. There was an increase in bite force with time, but a decline in EMG activity during the same period. In the mandible mobility analysis, only maximum mouth-opening values increased significantly after the surgical treatment. Conclusions. The masticatory musculature, according to bite force and EMG, returned to its normal condition by the second month after surgery, and maximum mouth opening was observed after the first month. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:e1-e7)

Properties and function of KCNQ1 K+ channels isolated from the rectal gland of Squalus acanthias

KCNQ1 (K(V)LQT1) K+ channels play an important role during electrolyte secretion in airways and colon. KCNQ1 was cloned recently from NaCl-secreting shark rectal glands. Here we study. the properties and regulation of the cloned sK(V)LQT1 expressed in Xenopus oocytes and Chinese hamster ovary (CHO) cells and compare the results with those obtained from in vitro perfused rectal gland tubules (RGT). The expression of sKCNQ1 induced voltage-dependent, delayed activated K+ currents, which were augmented by an increase in intracellular cAMP and Ca2+. The chromanol derivatives 293B and 526B potently inhibited sKCNQ1 expressed in oocytes and CHO cells, but had little effect on RGT electrolyte transport. Short-circuit currents in RGT were activated by alkalinization and were decreased by acidification. In CHO cells an alkaline pH activated and an acidic pH inhibited 293B-sensitive KCNQ1 currents. Noise analysis of the cell-attached basolateral membrane of RGT indicated the presence of low-conductance (

Structure-hepatic disposition relationships for cationic drugs in isolated perfused rat livers: Transmembrane exchange and cytoplasmic binding process

This work studied the structure-hepatic disposition relationships for cationic drugs of varying lipophilicity using a single-pass, in situ rat liver preparation. The lipophilicity among the cationic drugs studied in this work is in the following order: diltiazem. propranolol. labetalol. prazosin. antipyrine. atenolol. Parameters characterizing the hepatic distribution and elimination kinetics of the drugs were estimated using the multiple indicator dilution method. The kinetic model used to describe drug transport (the two-phase stochastic model) integrated cytoplasmic binding kinetics and belongs to the class of barrier-limited and space-distributed liver models. Hepatic extraction ratio (E) (0.30-0.92) increased with lipophilicity. The intracellular binding rate constant (k(on)) and the equilibrium amount ratios characterizing the slowly and rapidly equilibrating binding sites (K-S and K-R) increase with the lipophilicity of drug (k(on) : 0.05-0.35 s(-1); K-S : 0.61-16.67; K-R : 0.36-0.95), whereas the intracellular unbinding rate constant (k(off)) decreases with the lipophilicity of drug (0.081-0.021 s(-1)). The partition ratio of influx (k(in)) and efflux rate constant (k(out)), k(in)/k(out), increases with increasing pK(a) value of the drug [from 1.72 for antipyrine (pK(a) = 1.45) to 9.76 for propranolol (pK(a) = 9.45)], the differences in k(in/kout) for the different drugs mainly arising from ion trapping in the mitochondria and lysosomes. The value of intrinsic elimination clearance (CLint), permeation clearance (CLpT), and permeability-surface area product (PS) all increase with the lipophilicity of drug [CLint (ml . min(-1) . g(-1) of liver): 10.08-67.41; CLpT (ml . min(-1) . g(-1) of liver): 10.80-5.35; PS (ml . min(-1) . g(-1) of liver): 14.59-90.54]. It is concluded that cationic drug kinetics in the liver can be modeled using models that integrate the presence of cytoplasmic binding, a hepatocyte barrier, and a vascular transit density function.

Saturable dose-response relationships for melphalan in melanoma treatment by isolated limb infusion in the nude rat

Nude rats bearing melanomas on their hindlimbs were treated by isolated limb infusion (ILI) with increasing doses (7.5-400 mug/ml) of melphalan. The response of tumours to treatment at the end of the observation period was graded, according to diameter, as complete response (CR), partial response (PR), no change (NC) or progressive disease (PD). No linear relationship between the dose of melphalan and the tumour response was observed. All doses above a threshold of 15 mug/ml achieved a PR or CR. The achievement of CR was not related to increased dose. Two major implications arise from this work. Firstly, the typically two-to three-fold increase in cytotoxic drug concentration given in high dose chemotherapy compared with standard drug concentration may not be sufficient to produce the expected increase in tumour response and possibly survival, and the controversial results of high dose chemotherapy in different studies may thus be explained. Secondly, since an increase in melphalan dose above a certain threshold does not greatly increase tumour response, the use of combination therapies would seem to be more likely to be effective than increased chemotherapeutic drug doses in achieving better tumour responses.

Pharmacokinetics and pharmacodynamics of melphalan in isolated limb infusion for recurrent localized limb malignancy

Isolated limb infusion (ILI) is an attractive, less complex alternative to Isolated limb perfusion (ILP). It has a lower morbidity in treating localized recurrences and in transit metastases of the limb for tumours such as melanoma, Merkel cell tumour and Kaposi's sarcoma, allowing administration of high concentrations of cytotoxic agent to the affected limb under hypoxic conditions. Melphalan is the preferred cytotoxic agent for the treatment of melanoma by ILP or ILI. We report pharmacokinetic data from 12 patients treated by ILI for tumours of the limb in Brisbane. The kinetics of drug distribution in the limb was calculated using a two-compartment vascular model, where both tissue and infusate act as well-stirred compartments. Analysis of melphalan concentrations in the perfusate during ILI showed good agreement between the values measured and the concentrations predicted by the model. Recirculation and wash-out flow rates, tissue concentrations and the permeability surface area product (PS) were calculated. Correlations between the PS value and the drug concentrations In the perfusate and tissue were supported by the results. These data contribute to a better understanding of the distribution of melphalan during ILI in the limb, and offer the opportunity to optimize the drug regimen for patients undergoing ILI. (C) 2001 Lippincott Williams & Wilkins.

Microdialysis and response during regional chemotherapy by isolated limb infusion of melphalan for limb malignancies

This study sought to use a microdialysis technique to relate clinical and biochemical responses to the time course of melphalan concentrations in the subcutaneous interstitial space and in tumour tissue (melanoma, malignant fibrous histiocytoma, Merkel cell tumour and osteosarcoma) in patients undergoing regional chemotherapy by Isolated Limb Infusion (ILI). 19 patients undergoing ILI for treatment of various limb malignancies were monitored for intra-operative melphalan concentrations in plasma and, using microdialysis, in subcutaneous and tumour tissues. Peak and mean concentrations of melphalan were significantly higher in plasma than in subcutaneous or tumour microdialysate. There was no significant difference between drug peak and mean concentrations in interstitial and tumour tissue, indicating that there was no preferential uptake of melphalan into the tumours. The time course of melphalan in the microdialysate could be described by a pharmacokinetic model which assumed melphalan distributed from the plasma into the interstitial space. The model also accounted for the vascular dispersion of melphalan in the limb. Tumour response in the whole group to treatment was partial response: 53.8% (n = 7); complete response: 33.3% (n = 5); no responses 6.7% (n = 1). There was a significant association between tumour response and melphalan concentrations measured over time in subcutaneous microdialysate (P < 0.01). No significant relationship existed between the severity of toxic reactions in the limb or peak plasma creatine phosphokinase levels and peak melphalan microdialysate or plasma concentrations. It is concluded that microdialysis is a technique well suited for measuring concentrations of cytotoxic drug during ILI. The possibility of predicting actual concentrations of cytotoxic drug in the limb during ILI using our model opens an opportunity for improved drug dose calculation. The combination of predicting tissue concentrations and monitoring in microdialysate of subcutaneous tissue could help optimise ILI with regard to post-operative limb morbidity and tumour response. (C) 2001 Cancer Research Campaign http:,//www.bjcancer.com.

Flaviviruses isolated from mosquitoes collected during the first recorded outbreak of Japanese encephalitis virus on Cape York Peninsula, Australia

In response to an outbreak of Japanese encephalitis (JE) virus on Cape York Peninsula, Australia, in 1998, mosquitoes were collected using CO2 and octenol-baited Centers for Disease Control and Prevention light traps. A total of 35,235 adult mosquitoes, comprising 31 species, were processed for virus isolation. No isolates of JE virus were recovered from these mosquitoes. However, 18 isolates of Kokobera virus, another flavivirus were obtained from Culex annulirostris. Twelve isolates were from western Cape York (minimum infection rate (MIR) of 0.61: 1,000 mosquitoes) and 6 were from the Northern Peninsula Area (MIR of 1.0:1,000). Potential explanations for the failure to detect JE virus in mosquitoes collected from Cape York Peninsula include the timing of collections, the presence of alternative bloodmeal hosts, differences in pig husbandry, asynchronous porcine seroconversion, and the presence of other flaviviruses.

Disposition of naproxen, naproxen acyl glucuronide and its rearrangement isomers in the isolated perfused rat liver

1. An isolated perfused rat liver (IPRL) preparation was used to investigate separately the disposition of the non-steroidal anti-inflammatory drug (NSAID) naproxen (NAP), its reactive acyl glucuronide metabolite (NAG) and a mixture of NAG rearrangement isomers (isoNAG), each at 30 mug NAP equivalents ml(-1) perfusate (n = 4 each group). 2. Following administration to the IPRL, NAP was eliminated slowly in a log-linear manner with an apparent elimination half-life (t(1/2)) of 13.4 +/-4.4 h. No metabolites were detected in perfusate, while NAG was the only metabolite present in bile in measurable amounts (3.9 +/-0.8%, of the dose). Following their administration to the IPRL, both NAG and isoNAG were rapidly hydrolysed (t(1/2) in perfusate=57 +/-3 and 75 +/- 14min respectively). NAG also rearranged to isoNAG in the perfusate. Both NAG and isoNAG were excreted intact in bile (24.6 and 14.8% of the NAG and isoNAG doses, respectively). 3. Covalent NAP-protein adducts in the liver increased as the dose changed from NAP to NAG to isoNAG (0.20 to 0.34 to 0.48% of the doses, respectively). Similarly, formation of covalent NAP-protein adducts in perfusate were greater in isoNAG-dosed perfusions. The comparative results Suggest that isoNAG is a better substrate for adduct formation with liver proteins than NAG.

Diversity of Phytophthora clandestina isolated from subterranean clover in southern australia: Analysis of virulence and RAPD profiles

The virulence spectrum of 112 isolates of Phytophthora clandestina collected from 56 sites in four subterranean clover-growing states in southern Australia was determined using differential cultivars of subterranean clover. Five races were detected, with race 0 in all states except New South Wales, race 1 in all states, race 2 only in Victoria, race 3 only in New South Wales, and race 4 in Victoria and Western Australia. The level of genotypic diversity among the different P. clandestina populations was investigated using five RAPD primers. Among 30 bands amplified, only two were polymorphic. This enabled identification of four multilocus RAPD genotypes. Three of the four genotypes occurred in all four states. Races 2 and 3 occurred with RAPD genotypes 1 and 2 only whereas races 0 and 1 occurred in all four multilocus RAPD genotypes. These results indicate that the pathogenicity spectrum of P. clandestina can change rapidly.