Pharmacokinetic profile of a locally administered doxycycline gel in crevicular fluid,blood, and saliva

BACKGROUND: With the help of so-called controlled release delivery systems, the half-life period of locally administered antibiotics in gingival crevicular fluid (GCF) can be extended significantly. The aim of this study was to characterize the delivery profile of a new one-component 14% doxycycline free amine gel for local application. Pharmacokinetics of doxycycline (DOXY) were analyzed in GCF, saliva, and serum. METHODS: Twenty patients with persisting or recurring pockets (probing depths > or = 5 mm and bleeding on probing) after mechanical treatment (surgical or non-surgical) took part in the study. In each patient 1 periodontal defect was treated with DOXY gel. Samples of GCF, saliva, and serum were obtained before application of DOXY gel; 15 minutes after application; at 2 and 5 hours; and at 1, 2, 3, 4, 7, 9, and 11 days after application. Separation and quantitative measurement of DOXY was performed with high performance liquid chromatography and UV detection at lambda = 260 nm. RESULTS: Coefficients of variation were lower than 2% (intraassay) and 4% (interassay), respectively. For concentrations between 50 to 1000 microg/ml, we found a linear relationship between expected and measured DOXY values (linear coefficient of correlation: r = 0.998). Within the first 5 hours after application, concentration of DOXY in GCF (maximum after 15 minutes 19.97 +/- 5.85 mg/ml) and saliva (maximum after 15 minutes 17.83 +/- 2.84 mg/ml) was similar. Then concentration fell to a lower level (28.90 +/- 19.44 microg/ml) compared to GCF (577.41 +/- 127.34 microg/ml) after 3 days. Up to 10 days after application, the concentration of DOXY in GCF was 34.24 microg/ml. With the exception of 1 patient, all serum samples were DOXY-negative. CONCLUSIONS: 1) After subgingival application of biodegradable 14% doxycycline gel, mean doxycycline levels in GCF that exceeded 16 microg/ml could be maintained for at least 12 days. Thus, the antimicrobial agent may be classified as a controlled release device. 2) The antibiotic effect was limited mainly to the subgingival sites of application of the doxycycline gel. 3) The doxycycline gel possesses the pharmacokinetic and clinical properties to deliver efficacious levels of antibiotics to the periodontal pocket and to maintain these levels for at least 1 week without the need of further drug retention by a periodontal dressing.     

Analysis of Endothelial Adherence of Bartonella henselae and Acinetobacter baumannii Using a Dynamic Human Ex Vivo Infection Model

Bacterial adherence determines the virulence of many human-pathogenic bacteria. Experimental approaches elucidating this early infection event in greater detail have been performed using mainly methods of cellular microbiology. However, in vitro infections of cell monolayers reflect the in vivo situation only partially, and animal infection models are not available for many human-pathogenic bacteria. Therefore, ex vivo infection of human organs might represent an attractive method to overcome these limitations. We infected whole human umbilical cords ex vivo with Bartonella henselae or Acinetobacter baumannii under dynamic flow conditions mimicking the in vivo infection situation of human endothelium. For this purpose, methods for quantifying endothelium-adherent wild-type and trimeric autotransporter adhesin (TAA)-deficient bacteria were set up. Data revealed that (i) A. baumannii binds in a TAA-dependent manner to endothelial cells, (ii) this organ infection model led to highly reproducible adherence rates, and furthermore, (iii) this model allowed to dissect the biological function of TAAs in the natural course of human infections. These findings indicate that infection models using ex vivo human tissue samples (“organ microbiology”) might be a valuable tool in analyzing bacterial pathogenicity with the capacity to replace animal infection models at least partially.     

The evaluation of off-loading using a new removable oRTHOsis in DIABetic foot (ORTHODIAB) randomized controlled trial: study design and rationale

Background

Off-loading is essential for diabetic foot management, but remains understudied. The evaluation of Off-loading using a new removable oRTHOsis in DIABetic foot (ORTHODIAB) trial aims to evaluate the efficacy of a new removable device “Orthèse Diabète” in the healing of diabetic foot.

Methods/design

ORTHODIAB is a French multi-centre randomized, open label trial, with a blinded end points evaluation by an adjudication committee according to the Prospective Randomized Open Blinded End-point. Main endpoints are adjudicated based on the analysis of diabetic foot photographs. Orthèse Diabète is a new removable off-loading orthosis (PROTEOR, France) allowing innovative functions including real-time evaluation of off-loading and estimation of patients’ adherence. Diabetic patients with neuropathic plantar ulcer or amputation wounds (toes or transmetatarsal) are assigned to one of 2 parallel-groups: Orthèse Diabète or control group (any removable device) according to a central computer-based randomization. Study visits are scheduled for 6 months (days D7 and D14, and months M1, M2, M3, and M6). The primary endpoint is the proportion of patients whose principal ulcer is healed at M3. Secondary endpoints are: the proportion of patients whose principal ulcer is healed at M1, M2 and M6; the proportion of patients whose initial ulcers are all healed at M1, M2, M3, and M6; principal ulcer area reduction; time-related ulcer-free survival; development of new ulcers; new lower-extremity amputation; infectious complications; off-loading adherence; and patient satisfaction. The study protocol was approved by the French National Agency for Medicines and Health Products Safety, and by the ethics committee of Saint-Louis Hospital (Paris). Comprehensive study information including a Patient Information Sheet has been provided to each patient who must give written informed consent before enrolment. Monitoring, data management, and statistical analyses are providing by UMANIS Life Science (Paris), independently to the sponsor. Since 27/10/2013, 13 centres have agreed to participate in this study, 117 participants were included, and 70 have achieved the study schedules. The study completion is expected for the end of 2016, and the main results will be published in 2017.

Conclusion

ORTHODIAB trial evaluates an innovating removable off-loading device, seeking to improve diabetic foot healing (ClinicalTrials.gov identifier: NCT01956162).

     

Biological Changes on the Compressing Side of Orthodontic Teeth Stimulating by Soft laser

目的：研究在弱激光作用下接受正畸力作用的牙齿的压力侧出现的生物学变化，为临床应用弱激光加速牙齿移动提供理论依据。方法：实验动物分2组，每组20只。A组动物接受正畸力，B组动物除接受正畸力之外，还接受弱激光照射。采用免疫组化检测层连蛋白的组间表达变化，采用原位杂交检测RANKL(receptor activator of NF-kB ligand)mRNA的组间表达变化。结果：免疫组化结果表明，新生血管活跃的高峰期出现在接受正畸力的第7d。与A组相比，接受弱激光照射的B组呈现层连蛋白的高表达。同样，与A组相比，原位杂交检测发现在接受弱激光照射的B组中，正畸牙压力侧呈现RANKL mRNA的高表达。结论：弱激光照射后能够促进正畸牙压力侧血管新生(呈现层连蛋白高表达)，从而促进破骨细胞的分化激活。此外弱激光还能够促进破骨细胞活化因子RANKL的表达，增强正畸牙压力侧的破骨细胞的活性，加快骨改建。     

Expression of cytokeratins in human enamel organ

Cytokeratin (CK) is a filament which plays a central role in epithelial tissue and, like the polypeptides of intermediate filaments in general, shows a high degree of tissue specificity. The CK expression patterns of odontogenic epithelia are still poorly described. We studied the distribution of individual CK polypeptides in the human enamel organ at bell stage and in remnants of the dental lamina. Our immunohistochemical study showed that epithelial cells stained for CKs 7, 13, 14 and 19 with slight changes in their pattern during the differentiation phase of odontogenesis. There was negative staining for all other CK polypeptides tested (CKs 8, 10, 16, 17 and 18). Most of the CKs in the enamel organ epithelia did not show differences related to the stage-specific state of differentiation, except for CKs 14 and 19 at the inner enamel epithelium. A strong label for CK 14 was present at the inner dental epithelium at early bell stage, and this was substituted by CK 19 at the late bell stage when the ameloblasts were fully differentiated.     

The effect of indirect trauma on the rat temporomandibular joint

The effect of indirect trauma to the rat temporomandibular joint (TMJ) is analysed by means of an experimental model. The trauma, applied from an angle-glenoid fossa direction, produced injury of the TMJ. The histological data demonstrated that the impact could produce fractures of the glenoid fossa, but no hemarthrosis was observed. Trauma, both with or without fracture, caused proliferative changes in the TMJ. The glenoid fossa, the articular disk and the articular surface of the condyle were injured. Thickening of the articular surfaces had resulted in reduced joint space. Subsequently, remodelling changes in the condyle were found.     

Radiotherapy in multilocalized lymphedema-associated angiosarcoma

We report an 80-year-old woman, suffering from a recurrence of a multilocalized lymphedema-associated angiosarcoma of the right arm. The tumor consisted of solid tumor cell formations and "classical" spongiform tumor complexes. In the tumor periphery, pathological endothelial cell proliferates on pre-existing dilated lymphatic capillaries were detectable, which, together with immunohistology (CD 31+/Desmoplakin-1-2.17+/CD 34-), supported the diagnosis of lymphangiosarcoma. Complete remission was achieved under radioimmunotherapy (54 Gy/Interferon beta). A further recurrence 3 months later outside the primary therapy fields was successfully treated with radiotherapy alone. During a follow-up observation period of 3 years, there was neither local recurrence nor metastasis. This case demonstrates for the first time the long-lasting efficacy of photon radiation in a case of histologically-defined lymphangiosarcoma. Further studies should elucidate the suitability of radio monotherapy as first-line therapy in lymphedema-associated angiosarcoma with lymphatic endothelium-like immunohistology.     

Efficacy of skin barrier creams

2 barrier creams (BC) were evaluated against the anionic detergent sodium lauryl sulphate (SLS) using a new human test model. In the repetitive irritation test (RIT) on human skin, the irritant SLS is applied to the ventral forearm of Healthy volunteers daily for 2 weeks. 1%, 5%, and 10% SLS is exposed to the skin for 30 min. using a glass cup 2.5 cm in diameter. The BC is applied 30 min before the irritant. Cutaneous irritation is assessed on a score for erythema (0 to 5+), and quantified by various biophysical techniques: transepidermal water loss (TEWL) by evaporimetry, skin blood flow volume (BFV) by laser-Doppler velocimetry, and -skill colour bi colorimetry (La^* value). 10 subjects were tested with SLS on one forearm without pretreatment (control) and with Taktosan Salbe as BC on the other forearm. A 2nd panel of 10 subjects was tested in the same way with SLS and Marly skin as BC. Taktosan Salbe was extremely effective in reducing the irritation by SLS: there were significant differences regarding all lest parameters for 10% SLS in the 2nd week. The most differentiating parameter was TEWL, revealing statistical differences as early as the 1st week for 10%. SLS and Taktosan Salbe, while the least differentiating sensitivity was found for La^*. In contrast, there was no significant suppression of irritancy in any parameter with Marly skin, either in the 1st week or in the 2nd week with any concentration of SLS. The results show the differentiating potential of the model developed. Results obtained with the previously described animal model are confirmed- Noninvasive biophysical techniques, particularly TEWL measurements, might be extremely valuable in identifying new active ingredients of BC.     

Human T lymphocytes and mast cells differentially express and regulate extra- and intracellular CXCR1 and CXCR2

CXCL8 plays a major role in cell recruitment to sites of inflammation. Apart from neutrophils, little is known, however, about the cellular distribution and regulation of CXCL8 receptors in cells involved in acquired and adaptive immune responses. In previous studies, we have demonstrated the extracellular expression and function of CXCR1/2 on mast cells and also detected an intracellular pool of CXCR1/2. Here, we have addressed the question of receptor regulation during stimulation of human mast cells (HMC-1 cell line) and have studied T cells in comparison. Cell permeabilization was performed to detect both surface and possible intracellular receptor pools. HMC-1 cells stained positive for both receptors on the cell surface (CXCR1, 50%; CXCR2, 51%) and also after cell permeabilization (CXCR1, 86%; CXCR2, 74%). Similarly, T cells exhibited both cell-surface receptor expression (CXCR1, 30%; CXCR2, 23%) and higher total receptor expression (CXCR1, 50%; CXCR2, 36%), although overall values were lower than that in HMC-1 cells. On immunoblot, molecular weights of extra- and intracellular receptors on mast cells were the same, excluding altered receptor glycosylation. On stimulation with phorbol 12-myristate 13-acetate plus calcium ionophore, a time-dependent decrease of surface-membrane receptors was observed in both cell types, while total receptor remained the same, suggesting that receptor shedding is not involved. The kinetics of membrane receptor internalization and replenishment differed for the two cell types. Furthermore, receptor internalization was associated with decreased F-actin polymerization, a basic prerequisite for cell migration. These findings demonstrate for the first time the expression of extra- and intracellular CXCR1/2 receptors on T cells and delineate the dynamics of CXCR1/2 receptors on mast cells and T cells. Furthermore, they suggest a cell-type-specific and finely tuned regulation of chemokine responses at the receptor level in the context of inflammation.