Dentin rehardening after indirect pulp treatment in primary teeth

PURPOSE

The purpose of this study was to investigate dentin rehardening in the remaining carious dentin after indirect pulp treatment (IPT) using microhardness analysis after 37 to 71 months.

METHODS

Eighteen teeth submitted to IPT and capped with calcium hydroxide (CH) or gutta-percha (GP) were evaluated (treated group). Ten sound molars and 10 molars with deep acute carious lesions were selected to serve as positive and negative control groups, respectively. In the treated group, restorations and pulp-capping materials were removed. In the positive control group, 3- to 4-mm deep cavities were prepared. In the negative control group, the carious tissue was removed. Microhardness analysis was performed at 10-, 35-, 60-, 85-, and 110-microm depths. Data were analyzed using 1-way analysis of variance (P<.05).

RESULTS

Microhardness values for sound, carious, and treated groups at 10-, 35-, 60-, 85-, and 110-microm depths showed a statistically significant difference (P<or=.01) among the groups for microhardness. No difference was observed between CH- and GP-treated groups for microhardness.

CONCLUSION

The results showed a hardness increase in treated teeth when compared to carious teeth in all dentin depths investigated, suggesting mineral gain after treatment.

Health impact of living near an abandoned mine--case study: Jales mines

The activities of mining exploitation in Campo de Jales were performed in an uncontrolled way and gave rise to serious environmental contamination: rubbish depositories have been accumulated with no treatment or maintenance. An investigation developed around Jales Mine showed the existence of some chemical impact originated from the waste produced during mining activities. Some "black spots" for a wide suite of heavy metals were determined in stream sediments and alluvium drained from Jales tailings, which could constitute hazard factors for the area and potential danger for public health. The main objective of this study is to know the effects on health caused by this environmental contamination. It is a case-control study, where two populations--from Campo de Jales and Vilar de Maçada--were compared. They both have very similar living conditions, and were inquired about health issues and screening for lead and cadmium exposure. The results point out to higher prevalence of irritating symptomatology in the mucous of the eyes and respiratory system as well as higher lead and cadmium exposure in the Campo de Jales population.

Fistula size and hemodynamics: an experimental model in canine femoral arteriovenous fistulas

PURPOSE

The objective was to evaluate the impact of anastomosis diameter on blood flow in an arteriovenous fistula (AVF), comparing two different anastomosis sizes with a modified side-to-side technique in canine femoral arteries.

METHODS

Ten mongrel dogs were subjected to two AVFs each, both using a modified side-to-side technique. On one side, the anastomosis diameter was 1.5 times the arterial diameter and on the other side 3.0 times the arterial diameter. Mean proximal and caudal blood flow and mean venous flow were measured using an electronic flowmeter 15, 20 and 25 min after surgery. The Mann-Whitney, Friedman and Wilcoxon non-parametric tests were used for data analysis (alpha < or = 0.05).

RESULTS

Femoral artery flow cranial to the fistula became 5.6 times greater in the 1.5 arterial diameter group, and 8.4 times greater in the 3.0 arterial diameter group, when compared to initial arterial flow. The mean flow in the cranial vein was greater in the 3.0 group (10.09 times greater vs. 6.46 times greater in the 1.5 group). Both in the proximal artery and in the vein there was a significantly greater flow in the group with the larger anastomosis diameter (Wilcoxon test). In the femoral artery caudal to the fistula, the flow in most of the animals was reversed: 3.5 times greater in the 1.5 group and 1.2 times greater in the 3.0 group, without statistical difference.

CONCLUSIONS

These results suggest that 3.0 times the arterial diameter for the AVF size in dogs leads to greater venous flow than with 1.5 times the arterial diameter, without increasing the reversed flow.

Pseudo-peptides derived from isomannide as potential inhibitors of serine proteases

Hepatitis C, Dengue and West Nile virus are among of the most important flaviviruses that share one important serine protease enzyme. Serine proteases belong to the most studied class of proteolytic enzymes, and are a primary target in the drug development field. In this paper, we describe the synthesis and preliminary molecular modeling studies of a novel class of N-t-Boc amino acid amides derived of isomannide as potential serine proteases inhibitors.

N-t-Boc-amino acid esters of isomannide Potential inhibitors of serine proteases

Hepatitis C, Dengue and West Nile virus are some of the most important flaviviruses, that share one important serine protease enzyme. Serine proteases are the most studied class of proteolytic enzyme and, in these cases, a primary target for drug discovery. In this paper, we describe the synthesis and preliminary molecular modeling studies of a novel class of N- t-Boc amino acid esters derived of isomannide as potential serine proteases inhibitors.

Efficacy of rectal artesunate compared with parenteral quinine in initial treatment of moderately severe malaria in African children and adults: a randomised study

BACKGROUND

Many patients with malaria of increasing severity cannot take medicines orally, and delay in injectable treatment can be fatal. We aimed to assess the reliability of absorption, antimalarial efficacy, and tolerability of a single rectal dose of artesunate in the initial management of moderately severe falciparum malaria.

METHODS

109 children and 35 adults were randomly assigned to rectal artesunate (single dose of about 10 mg/kg) or parenteral quinine treatment (10 mg/kg at 0, 4, and 12 h). The primary endpoint was the proportion of patients with peripheral asexual parasitaemia of less than 60% of that at baseline after 12 h. Secondary endpoints were clinical response and concentrations of drug in plasma. Analysis was by intention-to-treat.

FINDINGS

All artesunate-treated patients had pharmacodynamic or pharmacokinetic evidence of adequate drug absorption. 80 (92%) of 87 artesunate-treated children had a 12 h parasite density lower than 60% of baseline, compared with three of 22 (14%) receiving quinine (relative risk 0.09 [95% CI 0.04-0.19]; p<0.0001). In adults, parasitaemia at 12 h was lower than 60% of baseline in 26 (96%) of 27 receiving artesunate, compared with three (38%) of eight receiving quinine (relative risk 0.06 [0.01-0.44]; p=0.0009). These differences were greater at 24 h. Clinical response was equivalent with rectal artesunate and parenteral quinine.

INTERPRETATION

A single rectal dose of artesunate is associated with rapid reduction in parasite density in adults and children with moderately severe malaria, within the initial 24 h of treatment. This option is useful for initiation of treatment in patients unable to take oral medication, particularly where parenteral treatment is unavailable.

[Acute arthritis]

In the case of inflammatory disease of the joints, the first diagnostic step is to determine whether the patient has monoarthritis, oligoarthritis or polyarthritis. After excluding a septic or a crystal-related process by joint puncture and synovial fluid analysis, further laboratory investigations including immunological and bacteriological tests can contribute to the diagnosis, and imaging procedures may also be useful. Primary therapy can be provided with NSAIDs or easy-on-the-stomach coxibs. Where indicated, antibiotics or, if warranted by the diagnosis and in the presence of persistent effusion, corticosteroids.

Hypercoagulable syndromes: evaluation and management strategies for acute limb ischemia

Acute limb ischemia secondary to peripheral arterial thrombosis is a relatively uncommon but ominous form of vascular accident. Select inherited and acquired hypercoagulable states appear to contribute to an initial arterial thrombosis and, more importantly, recurrent thrombotic events. Mounting interest in hypercoagulability, the increased availability of hypercoagulable state "profiles," and enhanced ability to identify an abnormality in tested patients have promoted widespread testing. Unfortunately, widespread testing has had a limited beneficial impact on the management of acute limb ischemia. Ideally, costly and specialized testing should be limited to situations in which the results will have a tangible impact on patient care. Clear goals of testing should be determined before testing is performed. This article addresses a practical approach to hypercoagulable state testing in patients with acute limb ischemia with a focus on abnormalities that impact patient management.

Disconjugate oculomotor learning caused by feeble image-size inequality: differences between secondary and tertiary positions

In order to examine the minimum value of image-size inequality capable of inducing lasting disconjugacy of the amplitude of saccades, six normal emmetropic subjects were exposed for 16 min to 2% image size inequality. Subjects were seated at 1 m in front of a screen where a random-dot pattern was projected and made saccades of 7.5 and 15 deg along the horizontal and vertical principal meridians and to tertiary positions in the upper and lower field. During the training period, compensatory disconjugacy of the amplitude of the saccades occurred for the principal horizontal and vertical meridians; such increased disconjugacy persisted after training, suggesting learning. In contrast, for horizontal saccades to or from tertiary positions made in the upper and lower field, no consistent changes in the disconjugacy occurred, either during training or after the training condition. In an additional experiment, three subjects read sequences of words with the 2% magnifier in front of their dominant eye: in such a task, horizontal saccades to or from tertiary positions at the upper or lower field showed appropriate and lasting disconjugacy for two of the three subjects. We conclude that even a 2% image size inequality stimulates oculomotor learning, leading to persistent disconjugacy of saccades. The small disparity created by the image-size inequality is thus compensated by the oculomotor system rather than tolerated by the sensory system (e.g. by enlarging the Panum's area).

Mutations of the phenylalanine hydroxylase (PAH) gene in Brazilian patients with phenylketonuria

In the present study, 115 Brazilian families with phenylketonuria (PKU), mainly from the Southeast of the country, were studied using three laboratory methods (DGGE, SSCP, and sequencing). All 13 exons of the PAH gene were analyzed, including the splicing sites and the promoter region. We identified 50 distinct mutations and characterized 91% of the mutant alleles. The five most prevalent mutations of the 50 mutations identified (50% of the PKU alleles) were IVS10nt-11G-->A (17.4%), followed by R261Q (12.2%), V388M (9.1%), R252W (6.5%), and R270K (4.8%). The other mutations were rare. The mutation spectrum included 10 novel mutations (IVS5nt-54A-->G, IVS6nt17G-->T, E205A, F240S, K274E, I318T, L321L, C357G, IVS11nt17G-->A, and S411X). To characterize the origin and distribution of the PAH alleles we determined the association between the detected mutations and the PCR/RFLP haplotypes and VNTR alleles located on the PAH gene. For those patients whose mutant alleles were detected, we calculated the correlation with pretreatment phenylalanine levels, thus establishing a genotype/phenotype correlation. The present results confirm the marked heterogeneity observed at the PAH locus and contribute to the understanding of the distribution and frequency of PKU mutations in the Brazilian population.

[Surgical procedures in selected proctological patients with local anesthesia. Study of 150 cases]

Experience in the treatment of 150 patients with anorectal disorders and disorders of the sacrococcygeal region who were operated on with local anesthesia at the University Hospital, ABC Medical School, São Bernardo do Campo, SP, Brazil, from March 1995 to March 1998. The anesthesia technique, the operations carried out and the tolerance to the procedure are reported. Intraoperative morbidity was 10.6% (16 patients), and postoperative morbidity was 6% (nine patients). The age of patients was between 15 and 92 years old, with mean age 42 years old; 58% of patients were male and 42% female. Surgical mean time was 45 minutes and the patients remained in the hospital for a mean time of 8 hours. All of patients was instructed about the anesthesia technique, their advantages and disadvantages, and only with their permit the surgery was programmed. Hospitalization was required in five patients (3.3%). The anesthesia technique employed was the same for all patients. Upon survey, 96.7% of the patients stated they did not feel pain during the surgery and that they would go through the procedure again. The authors conclude the surgical treatment of anorectal disorders and disorders of the sacrococcygeal region with local anesthesia is viable and safe, and in addition, is well accepted by the patients.

Effects of inter-alpha-inhibitor and several of its derivatives on calcium oxalate crystallization in vitro

The bikunin peptide chain of the protease inhibitor inter-alpha-inhibitor (IalphaI) has been reported to be an inhibitor of calcium oxalate (CaOx) crystallization, and hence has been proposed as having a role in CaOx kidney stone formation. However, further experimental evidence is required to assess if fragments of IalphaI other than bikunin may play a role in the regulation of crystallization events in stone formation. The aim of the present study was to assess the effects of IalphaI and several of its derivatives on CaOx crystallization in a seeded inorganic system and to compare these effects with those of a known inhibitor of crystallization, prothrombin. IalphaI was purified from a preparation of human plasma and fragmented by alkaline hydrolysis, and two of its peptide chains, bikunin and heavy chain 1 (H1), were purified further by HPLC. Their purity was confirmed by SDS/PAGE. Using Coulter counter and [(14)C]oxalate analysis and scanning electron microscopy, IalphaI, its H1 chain and bikunin from urine and from plasma were shown to be relatively weak inhibitors of CaOx crystallization in vitro at expected physiological concentrations. It was concluded that members of the IalphaI family may not be as important in kidney stone formation as has been generally proposed, although further studies are required before a possible role for IalphaI and its fragments in stone formation can be unambiguously discounted.

What are the World Health Organization's strategies for meeting regulatory requirements? A case study of artesunate

The basic scope of WHO for developing new drugs or a new indication, is that of responding to a public health need, at an affordable price. This paper describes the approach taken by the organisation for the development of rectal artesunate and the special arrangements and approach which have made this possible for the WHO to meet regulatory requirements. Regulatory submission is planned in Europe and the USA, harmonising the submission, registration and labelling, and this precedent may constitute a worldwide reference for the deployment of the drug. The approach is novel, fast, and unbureaucratic, and can be applied to other drugs meeting a live-saving need.

What role can public health institutions play in drug development for the poor? A case study of artesunate

Although the strategy of artesunate development was orchestrated from within WHO's Special Programme for Research and Training in Tropical Diseases, it relies heavily upon an alliance of scientist, laboratories, industry, regulators and ministries of health to ensure the public health outcome. This development strategy has transformed the way in which WHO does business, both within and outside the Organization. In essence, each and every player has rallied in the challenge to reduce the discrepancy between need and availability of a drug that can has the potential to reduce mortality form the disease.

Comparison of the cytotoxicity of molybdenum as powder and as alloying element in a niobium-molybdenum alloy

Commercially pure metal niobium (c.p. Nb) as well as niobium-molybdenum (Nb-Mo) alloys were produced following several powder metallurgical routes. In brief, niobium and molybdenum powders were blended and milled in order to form Nb-Mo alloys. The alloy powders and the c.p. Nb were then either pressed and sintered, or cold isostatically pressed followed by hot isostatically pressing. In order to assess the cytotoxicity of the c.p. Nb and c.p. Mo powders, a 72 h minimal essential medium-extraction test was performed according to ISO/EN 10993-5. The cytotoxicity of the c.p. Nb metal and the Nb-Mo alloys was tested in a 72 h direct contact test. Compared to a negative control (UHMWPE), c.p. Nb was non-toxic, but c.p. Mo was moderately toxic. None of the powder metallurgically produced materials were toxic. Neither differences in molybdenum concentration, nor in porosity of the samples, due to different production routes, had any influence on the toxicity of the materials. Rat bone marrow cultures showed that only on c.p. Nb was a mineralized extracellular matrix formed, while on the more porous Nb-Mo alloys, cell growth was observed, but no mineralization. In conclusion, c.p. Mo powder is moderately toxic, however, as an alloying element it is non-toxic. Material porosity seems to influence differentiation of bone tissue in vitro.

More crops, more disease?

The intensity of disease transmission by insect vectors may be influenced by developments in agriculture and forestry. The author illustrates what can happen with special reference to projects in Thailand and Ethiopia which increased the incidence of malaria, and to the introduction of a new variety of coffee in Colombia, as a result of which the incidence of leishmaniasis among plantation workers decreased. Development programmes need to take predictable disease outcomes fully into account.

Interventions to improve the use of antimalarials in south-east Asia: an overview

There are few drugs for malaria, and those which are available for use are subject to rapid development of resistance. Curiously, little effort has been made to improve drug use in malaria-endemic countries and to assess the benefits of such improvements. Advances can be made in public understanding of the value of ingesting a full regimen of antimalarials, in order to achieve complete cure, and in improving simple technologies (blister packaging) to achieve the same result. Better efforts can be made to reduce the availability of fake or substandard drugs in the marketplace. In this article, we describe the outcome of a concerted effort to improve drug compliance and drug quality in an area of multidrug resistance for malaria. These research efforts, guided by the Task Force for Improved Use of Antimalarials, characterized the problems in drug compliance in South-East Asia, and developed interventions to improve drug use in the various countries. Interventions involved drug packaging, public information campaigns, and assessments of drug quality. Results show that blister packaging worked best to improve drug compliance and that the increased cost of packaged medication did not limit its use. Drug quality was a major problem in unregulated countries and should be improved.

Profile of Morong, Bataan, an area of low malaria endemicity in the Philippines

A malaria study area in the Philippines is described. It consists of the municipality of Morong, Bataan on the Island of Luzon. In January 1992, the population was 19454 in 106 villages located on a narrow coastal plain, or in valleys of streams running from the mountainous interior. This is an area of low level but persistent seasonal transmission of malaria with approximately one thousand cases reported each year, mainly from February to July. In spite of the low level of malaria, it is apparently quite stable. The study site has been used to investigate parameters leading to stable malaria. Hypotheses tested were that there was substantial under reporting of cases; that there was strain specific immunity stabilising the incidence of malaria and that malaria transmission in this area is highly localised in small regions with a high enough malaria prevalence to account for the year to year stability. The study plan included cross sectional surveys of parasite prevalence and seropositivity, longitudinal surveys, passive case detection, entomological surveys, anthropological surveys to assess knowledge of malaria and documentation of the health-seeking behaviour of the population.

Autologous blood donation in cardiac patients

Despite the advantages of autologous blood transfusion, doubt still remains about its safety in cardiac patients. We report our experience with 439 cardiac patients who donated a total of 1692 units of blood before coronary, valvular, or congenital cardiac operations. During the collections, patients were continuously monitored with ECG, blood pressure, and heart rate. In 22 collections we observed vasovagal reactions, which represents an incidence of 1.3% of the total number of collections. The patients recovered quickly and only in 3 cases was volume replacement with saline needed. There were no other complications which could be related to the preoperative autologous donation program. We feel that, with careful selection of the patients and of the circumstances surrounding the collection of blood, autologous blood donation in cardiac patients is a safe and beneficial experience.

Laser In Situ Keratomileusis for Myopia Using Manual Dissection

Forty-two eyes underwent interlamellar photoablation, a simple method of exposing the stroma to excimer laser treatment using common surgical instruments. A 8 mm diameter line up to 200 microns thick is raised manually from its bed. The stromal bed is reshaped with the excimer laser, and restoring the disc results in correction of high myopia. Our own nomogram was used. This method allows the use of less corticosteroids and final visual acuity recovers between 20 and 90 days postoperatively, time required for interface adherence and epithelial remodeling. Two treatment zones were used when 80% of the patient's myopia was greater than 10.00 diopters (D). One-year follow-up data allowed us to conclude that this method achieved results similar to excimer laser in situ keratomileusis (LASIK).

Keratomileusis-in-situ using manual dissection of corneal flap for high myopia

Overcorrection, regression and haze are some side-effects found after excimer laser photorefractive keratectomy (PRK) for high myopia. A new method attempts to avoid photoablation through Bowman's layer, using the stroma to flatten the cornea without use of a microkeratome. Manual surgical instruments such as the diamond blade, spatula, Pierce forceps, and Vannas scissors are used to remove a disc of anterior cornea. Minimal topical corticosteroids are used, avoiding the complications of prolonged corticotherapy. Six eyes underwent manual excimer laser keratomileusis-in-situ. Postoperatively, the epitheliums in these eyes initially were dry and excoriated. By the twentieth day, however, the eyes had re-epithelialized and recovered. The optical effect is the same as when keratomileusis is used. No more than three-fourths of the pre-existing myopia was used in the program as some undercorrection was desired.

The reliability of Hickman catheter blood for the assessment of activation markers of coagulation and fibrinolysis in patients with hematological malignancies

We studied the reliability of Hickman catheter (HC) blood for the determination of activation markers of coagulation and fibrinolysis in 14 patients with hematological malignancies. 10 of 22 HC samples were contaminated with heparin, probably as a consequence of our institutional antithrombotic catheter care, and withdrawn from statistical analysis. Prothrombin activation fragment F1.2, thrombin-antithrombin III complexes, soluble fibrin, degradation products of fibrinogen and fibrin, total degradation products, alpha 2-antiplasmin and antithrombin III levels withdrawn from Hickman catheters did not differ significantly from peripheral venous blood samples. Fibrinogen levels were slightly but significantly higher in peripheral venous blood samples. We conclude that Hickman catheter blood gives reliable results for the determination of activation markers of coagulation and fibrinolysis in patients with hematological malignancies, but may be less useful in clinical practice due to frequent heparin contamination.