Physical key properties of antibiotic-free, PLGA/HPMC-based in-situ forming implants for local periodontitis treatment.

In-situ forming implants (ISFI) offer an interesting potential for the treatment of periodontitis, allowing for time-controlled drug release directly at the site of action (which is difficult to reach). For this purpose, ISFI loaded with antibiotics have been reported in the literature. But the use of antibiotic drugs at low doses over prolonged periods of time can lead to the development of bacterial resistances. This risk should be avoided. The aim of this study was to develop a novel type of in-situ forming implants, loaded with the antiseptic drug chlorhexidine. Special emphasis was placed on the physical properties of the systems, assuring a reliable residence time in the periodontal pockets of patients suffering from periodontitis. In particular, the risk of premature, accidental loss of the formulations due to mechanical stress (e.g. during tooth brushing and chewing) was to be reduced. Two commercially available drug products for local periodontitis treatment were studied for reasons of comparison: Chlo-site and Parocline. The syringeability and swelling behavior of the formulations were investigated, and the hardness, springiness, resilience and "stickiness" of the systems determined using extracted human teeth. Interestingly, the novel in-situ forming implants, based on PLGA/HPMC and being free of antibiotics, exhibit highly promising physical key properties: They are intensively sticking to teeth' surfaces and provide adequate mechanical strength to assure reliable and prolonged residence times in periodontal pockets. In contrast, the commercial drug products showed limited adhesion and either rapidly shrank (Chlo-site), or substantially swelled and were mechanically very weak (Parocline).

Periodontal manifestations of inflammatory bowel disease: emerging epidemiologic and biologic evidence.

Inflammatory bowel disease and periodontitis are both described as a disproportionate mucosal inflammatory response to a microbial environment in susceptible patients. Moreover, these two conditions share major environmental and lifestyle-related risk factors. Despite this intriguing pathogenic parallel, large-scale studies and basic research have only recently considered periodontal outcomes as relevant data. There are mounting and consistent arguments, from recent epidemiologic studies and animal models, that these two conditions might be related. This article is a comprehensive and critical up-to-date review of the current evidence and future prospects in understanding the biologic and epidemiologic relationships between periodontal status and inflammatory bowel disease.

Potency values from the local lymph node assay: application to classification, labelling and risk assessment.

Hundreds of chemicals are contact allergens but there remains a need to identify and characterise accurately skin sensitising hazards. The purpose of this review was fourfold. First, when using the local lymph node assay (LLNA), consider whether an exposure concentration (EC3 value) lower than 100% can be defined and used as a threshold criterion for classification and labelling. Second, is there any reason to revise the recommendation of a previous ECETOC Task Force regarding specific EC3 values used for sub-categorisation of substances based upon potency? Third, what recommendations can be made regarding classification and labelling of preparations under GHS? Finally, consider how to integrate LLNA data into risk assessment and provide a rationale for using concentration responses and corresponding no-effect concentrations. Although skin sensitising chemicals having high EC3 values may represent only relatively low risks to humans, it is not possible currently to define an EC3 value below 100% that would serve as an appropriate threshold for classification and labelling. The conclusion drawn from reviewing the use of distinct categories for characterising contact allergens was that the most appropriate, science-based classification of contact allergens according to potency is one in which four sub-categories are identified: 'extreme', 'strong', 'moderate' and 'weak'. Since draining lymph node cell proliferation is related causally and quantitatively to potency, LLNA EC3 values are recommended for determination of a no expected sensitisation induction level that represents the first step in quantitative risk assessment.

Surgical findings and post-operative parathormone levels in patients with secondary hyperparathyroidism.

OBJECTIVE: The peri-operative and immediate post-operative outcome of secondary hyperparathyroidism treated with subtotal parathyroidectomy is reported. METHODS: We studied 100 patients with chronic renal failure who underwent subtotal parathyroidectomy at our department. Surgical eligibility was based on hyperparathyroidism stage, defined by symptoms of osteodystrophy and/or the presence of hypercalcemia and hyperphosphatemia refractory to medical treatment. Parathormone levels were measured pre-operatively and during the first post-operative days. RESULTS: During surgery, four parathyroid glands were identified in 86% of patients, five glands in 1%, and less than four glands in 13%. The ratio of hyperplastic to normal glands was 93:7. No correlation was found between anatomic location of the glands and the presence of hyperplasia. Parathormone decreased to normal or very low values in 93% of the patients. In seven cases, the lowest post-operative parathormone value was above 30 pg/ml, although four glands were removed in four of these patients. In 95% of the patients with four or more identified glands, post-operative serum parathormone levels decreased to normal or very low values. In 23% of the patients with less than four glands, parathormone levels remained too high. On the other hand, post-operative parathormone values normalized in 10 patients who had less than four glands identified during surgery; in two of them, parathyroid tissue was found during postoperative pathological examinations of the resected thyroid lobe. CONCLUSIONS: Subtotal parathyroidectomy is an acceptable treatment in patients with refractory hyperparathyroidism. Our results indicate that there was not a perfect correlation between the number of identified glands and post-operative parathormone in a subset of patients.

Functionalization of PVDF membranes with carbohydrate derivates for the controlled delivery of chlorhexidin.

Maltodextrin (MX) was fixed onto PVDF membranes in order to create a drug delivery Guided Tissue Regeneration (GTR) device with controlled drug delivery properties. PVDF microporous membranes were treated by a mixture of MX and citric acid, resulting to an 18 wt% increase of the supports. MX grafted membrane could capture 103 mg/g chlorhexidin digluconate (DigCHX) instead of 1mg/g for a virgin membrane. A neutralization step was performed before the biological tests. Viability tests confirmed the non-toxicity of the MX polymer coating after neutralisation. In vitro release test in human plasma, and microbiological tests showed that membranes grafted with MX were more performing compared to virgin and beta-CD grafted membranes. The antimicrobial activity was effective during more than 72 h.

Improved drug delivery properties of PVDF membranes functionalized with beta-cyclodextrin--application to guided tissue regeneration in periodontology.

The purpose of this study was to develop a membrane for guided tissue regeneration applicable in periodontology that could release antimicrobial agent during the healing period. Our strategy consisted to graft beta-cyclodextrin (beta-CD), a molecule that is known to form inclusion complexes with a large variety of drugs, onto PVDF membranes. Grafting occurred by using citric acid that provoked a crosslinking reaction of beta-CD, and the resulting polymer was imprisoned into the porous structure of the PVDF membrane. The reaction produced a weight increase of the membrane, the range of which depended on the temperature and on the time of curing applied in the process. The biological behavior of the membranes evaluated by proliferation and vitality tests showed good proliferation and improved activity of L132 epithelial cells on the raw and on the grafted membranes. Doxycyclin (DOX) and chlorhexidine (CHX) were used as antimicrobial agents. Their inclusion into the beta-CD cavity in aqueous solutions was confirmed by NMR spectroscopy. After the impregnation of the membranes with DOX and CHX, their release was studied in vitro in batch type experiments and measured by UV spectrophotometry. Low amounts of DOX and CHX were delivered from the raw membranes within the first few hours of tests. Grafted membranes, however, delivered DOX and CHX in larger quantities within 24 h and 10 days respectively.

[Periodontal diseases, tobacco and pregnancy]. / Maladies parodontales, tabac et grossesse.

This review summarizes the impact of tobacco on the periodontium of pregnant women and the effects of periodontal diseases combined with tobacco on the pregnancy. Periodontal diseases (gingivitis and periodontitis) are gram-negative anaerobic infections. Smokers are 2-7 times more likely to develop periodontal disease than non-smokers. Tobacco, an environmental factor, undermines the host response and may facilitate the development and progression of periodontal disease. Recent epidemiological studies suggest that maternal periodontal diseases would be a risk factor of pre-term deliveries or pre-term low birth weight (PLBW). Cigarette smoking during pregnancy leads to peri-natal morbidity and mortality and it is associated with reduced birth-weight. Tobacco during pregnancy also amplifies the risk of PLBW directly and via periodontal diseases. This article highlights the etio-pathogenic interrelations between periodontal diseases and tobacco as risk factors of PLBW. The blood dissemination of periodontal bacteria and the effects of cytokines like TNF-alpha, Il-1, produced during periodontal infections could explain these obstetrical adverse events. The concept of diagnosing and treating a periodontal disease in a pregnant woman to minimizes the deleterious effects of this infection on systemic conditions represents an unprecedented challenge. Moreover, periodontist have the opportunity to take part in smoking cessation program for pregnant women.

Assessment of the safety of foods derived from genetically modified (GM) crops.

This paper provides guidance on how to assess the safety of foods derived from genetically modified crops (GM crops); it summarises conclusions and recommendations of Working Group 1 of the ENTRANSFOOD project. The paper provides an approach for adapting the test strategy to the characteristics of the modified crop and the introduced trait, and assessing potential unintended effects from the genetic modification. The proposed approach to safety assessment starts with the comparison of the new GM crop with a traditional counterpart that is generally accepted as safe based on a history of human food use (the concept of substantial equivalence). This case-focused approach ensures that foods derived from GM crops that have passed this extensive test-regime are as safe and nutritious as currently consumed plant-derived foods. The approach is suitable for current and future GM crops with more complex modifications. First, the paper reviews test methods developed for the risk assessment of chemicals, including food additives and pesticides, discussing which of these methods are suitable for the assessment of recombinant proteins and whole foods. Second, the paper presents a systematic approach to combine test methods for the safety assessment of foods derived from a specific GM crop. Third, the paper provides an overview on developments in this area that may prove of use in the safety assessment of GM crops, and recommendations for research priorities. It is concluded that the combination of existing test methods provides a sound test-regime to assess the safety of GM crops. Advances in our understanding of molecular biology, biochemistry, and nutrition may in future allow further improvement of test methods that will over time render the safety assessment of foods even more effective and informative.

Induction of IgE antibody responses by protein allergens: inter-laboratory comparisons.

There is a growing interest in the development of methods for the evaluation of the allergenic potential of novel proteins. One approach is the measurement of specific IgE antibody production stimulated by systemic (intraperitoneal; i.p.) exposure of BALB/c strain mice. In the current investigations, inter-laboratory comparisons have been performed of IgE antibody production induced in mice by food proteins of differing sensitizing potential. Female BALB/c strain mice (n=5) were exposed to 0.1% peanut agglutinin, an allergenic constituent of peanuts, to 2% ovalbumin (OVA), a major allergenic constituent of hens' egg, or to a protein considered to lack significant allergenicity, potato agglutinin (5%). Specific IgE antibody was measured by homologous passive cutaneous anaphylaxis assay and IgG and IgG1 antibody production was analysed by enzyme-linked immunosorbent assay (ELISA). Two independent experiments were conducted in each laboratory, but with all serological analyses conducted in one of the laboratories. Each of the proteins induced vigorous IgG and IgG1 antibody responses, with no statistically significant differences in titres recorded between laboratories. Furthermore, OVA and potato agglutinin induced responses of equivalent immunogenicity with respect to both IgG and IgG1 antibody titres. Administration of peanut agglutinin and OVA each stimulated marked IgE antibody responses in every experiment. In the two laboratories, titres ranged from 1:32 and 1:64 for peanut agglutinin, and from 1:8 and 1:32 for OVA. In contrast, exposure to potato agglutinin failed to induce vigorous IgE production, with no detectable IgE (negative with neat serum), or titres of 1 (positive with neat serum only) recorded. These data demonstrate that the induction of IgE antibody by food proteins of differing allergenic potential is a relatively robust phenomenon and transferable between laboratories. Furthermore, these results provide additional evidence that the measurement of antibody (IgE) responses in BALB/c mice may allow discrimination between allergens and those materials that apparently lack allergenicity.

Tumorigenic potential of carbaryl in the heterozygous p53 knockout mouse model.

The heterozygous p53 knockout mouse model was used to assess whether vascular tumors noted in a 2-year carcinogenicity study in CD-1 mice with carbaryl were induced through a genotoxic mechanism. This knockout mouse model was selected for carbaryl because of the high sensitivity of this model to genotoxic events and its low spontaneous incidence of tumors until 9-12 months of age. Carbaryl was administered continuously via the diet to groups of 20 male heterozygous p53 knockout mice at concentrations of 0, 10, 30, 100, 300, 1000 and 4000 ppm for 180 days. Histopathological examinations revealed no evidence of carbaryl-induced neoplasms of any type. In particular, no neoplastic or preneoplastic changes were noted in the vascular tissue of any of the organs examined. Only neoplasms, recognized as those that occur spontaneously in untreated mice of this strain, were sporadically observed in a few animals from the intermediate dose groups with no evidence of a dose- or treatment-related effect. Therefore, under the conditions of this study, the no-observed-effect level (NOEL) of carbaryl for neoplastic changes in male mice was 4000 ppm (around 716 mg/kg body weight/day). We conclude: (1) carbaryl does not appear to be a genotoxic carcinogen at least in male mice; (2) if the vascular tumors observed in the CD-1 mice are treatment-related, they could have been induced by a non-genotoxic mechanism; (3) the response in transgenic animals may provide useful complementary results to better assess carbaryl's potential genotoxic hazard to humans.

Features of severe periodontal disease in a teenager with Chédiak-Higashi syndrome.

BACKGROUND: Chédiak-Higashi syndrome (C-HS) is a rare congenital disease characterized by defective neutrophil function with abnormal lysosomal inclusions, neutropenia, and reduced chemotaxis. The complete syndrome includes oculocutaneous albinism with photophobia, neurologic features, recurrent infections, and enterocolitis. METHODS: A 14-year-old male C-HS patient was referred to us because of serious periodontal destruction with acute inflamed gingiva and ulcers. Clinical and biological investigations were performed, leading to the diagnosis of C-HS. RESULTS: Laboratory findings included neutropenia and hypergammaglobulinemia. Peripheral blood smears showed giant granules in neutrophils, eosinophils, and granulocytes. Bone marrow smears showed giant inclusions in leukocyte precursor cells. These granules and inclusions were characteristic of Chédiak-Higashi syndrome. Oral radiographic status showed extensive loss of alveolar bone leading, in most cases, to tooth exfoliation. Bacteria often associated with periodontitis were detected in subgingival plaque samples, including Fusobacterium nucleatum, Campylobacter rectus, Prevotella melaninogenica, Peptostreptococcus anaerobius, and Clostridium sp. Biopsies of periodontal tissues for light and electronic microscopic examinations revealed massive bacterial invasion of the epithelial tissue, epithelial cells, and connective tissue. Ultrastructural observations of periodontal polymorphonuclear leukocytes showed defective granulation, with abnormal granules not discharging their lysosomal content against engulfed bacteria. Viable dividing bacteria were found in the cytoplasm. CONCLUSIONS: In this case, early-onset periodontitis seems to be the expression of C-HS granulocyte deficiency. Periodontal treatment of these patients is often unsuccessful. This case report illustrates the importance of the dentist in initiating clinical and biological investigations in such early aggressive periodontitis in young patients.

The p53 heterozygous knockout mouse as a model for chemical carcinogenesis in vascular tissue.

Heterozygous p53 knockout mice were investigated as a potential model for vascular tumor carcinogenesis. Groups of 20 male mice were exposed by gavage for 6 months to the vascular carcinogen urethane at 1, 10, or 100 mg/kg body weight/day. Wild-type and heterozygous p53 knockout control groups were exposed by gavage to the vehicle alone. Another group of 20 male mice received d-limonene by gavage (d-limonene is noncarcinogenic in mice). The high dose of urethane caused early mortality in the majority of mice associated with histopathologic evidence of toxicity and tumors, including a high incidence of benign and malignant vascular tumors, in all animals. At the intermediate dose, toxicity was less marked and 3 of 20 mice had tumors; mice that received the low dose did not have signs of toxicity or neoplasia. The two control groups had no tumors and the d-limonene group had one tumor of the prostate, which was considered spontaneous. We conclude that the p53 knockout mouse is a useful tool for investigating vascular tumorogenesis.

Phenobarbital, beta-naphthoflavone, clofibrate, and pregnenolone-16alpha-carbonitrile do not affect hepatic thyroid hormone UDP-glucuronosyl transferase activity, and thyroid gland function in mice.

The effects of representative liver enzyme inducers such as clofibrate (CLO), phenobarbital (PB), pregnenolone-16alpha-carbonitrile (PCN), and beta-naphthoflavone (NF) on hepatic microsomal thyroxin (T4)- UDP-glucuronosyl transferase (UGT) and triiodothyronine (T3)- UGT activities and thyroid function were evaluated in OF-1 male mice after a 14-day po administration. CLO, PB, and PCN induced histological liver hypertrophy, increases in liver weights, in microsomal protein and cytochrome P450 contents as well as increases in specific UGT activities. Despite this, no significant changes in T4-UGT and T3-UGT activities occurred after treatment by any of these compounds. Furthermore, no significant changes in serum T4 and T3 levels were observed and thyroid histology was not affected. NF treatment induced microvacuolation of hepatocytes but did not affect any of the other tested parameters. The results show that, in contrast to the widely described effects in rats, liver enzyme inducers do not affect hepatic thyroid hormone metabolism and thyroid function in mice, suggesting that this species should be less sensitive to thyroid tumor promotion by hepatic microsomal enzyme inducers than rats.

The correlation between prostate volume, transition zone volume, transition zone index and clinical and urodynamic investigations in patients with lower urinary tract symptoms.

OBJECTIVE: To determine if, in patients with lower urinary tract symptoms (LUTS), measurement of the transition zone (TZ) of the prostate by transrectal ultrasonography (TRUS) and the ratio between the TZ volume and total prostate volume (TZ index) correlates better with clinical and urodynamic investigations than total prostate volume alone. PATIENTS AND METHODS: In total, 150 consecutive patients with LUTS underwent a standardized screening programme including the International Prostate Symptom Sore (IPSS), a physical examination, TRUS of the prostate and urodynamic investigations with pressure-flow studies. The total prostate volume and TZ volume were assessed from TRUS using the ellipsoid formula. Spearman's rank correlation coefficients were calculated between different prostate volume measurements and specific symptomatic and urodynamic variables. RESULTS: The relationships between specific IPSS symptoms, symptom scores and the prostate volume measurements were not statistically significant except for one domain, nocturia, that appeared to be statistically significantly correlated with the TZ index (r = 0.25). The correlations for free flow, pressure-flow variables and prostate volume measurements were stronger, but only moderate at best. The highest correlations were between TZ volume and the linear passive urethral resistance obstruction category, urethral resistance factor and detrusor pressure at maximum flow (r = 0.43, 0.44 and 0.40, respectively). The differences between the correlations of prostate volume and TZ index and these variables were small (r = 0.39, 0.38 and 0.37, respectively for prostate volume and r = 0.38, 0.40 and 0.33 respectively for TZ index). CONCLUSIONS: There were very small differences between the correlations of total prostate volume, TZ volume and TZ index, and clinical and pressure-flow variables. In the assessment of the last two, the estimation of the total prostate volume by TRUS was a reasonable way to obtain the required information about prostate size and measuring TZ volume and calculating TZ index was of limited additional value. Symptoms and bladder outlet obstruction were mainly determined by other factors than the prostate and, specifically, TZ volume. As earlier studies have indicated that including pressure-flow data in the pre-operative evaluation and selection of patients for interventional therapies may improve the overall clinical results, we think that prostate volume, TZ volume or symptoms alone should not be used as the main indication for deciding on the appropriate invasive treatment options.

Effect of suloctidil on rat liver.

The effect of suloctidil (120 mg/kg body weight PO for 3 weeks) on rat liver was investigated using biochemical and morphological methods: enzymatic activities characteristic of the main cellular compartments were used as biochemical markers of hepatocyte function and morphometry was applied to investigate morphological changes. No sign of hepatotoxicity was evidenced after suloctidil treatment (liver weight; cytochrome c oxidase; glucose 6-phosphatase; NADPH-cytochrome c reductase; D-amino acid oxidase; urate oxidase; fatty acid oxidation; peroxisomal number, volume and size distribution). Suloctidil increased catalase activity by 22% without morphologically detectable changes in the peroxisomes. After suloctidil treatment, slightly increased mitochondrial volume fraction and slightly decreased mitochondrial number were noted without significant changes in cytochrome c oxidase. Clofibrate, at the same dose, increased NADPH-cytochrome c reductase, catalase, acylCoA oxidase, mitochondrial and peroxisomal number and volume fraction, and decreased urate oxidase activity.