TET-mediated hydroxymethylcytosine at the Pparγ locus is required for initiation of adipogenic differentiation.

BACKGROUND/OBJECTIVES: Adipose tissue is one of the main organs regulating energy homeostasis via energy storage as well as endocrine function. The adipocyte cell number is largely determined by adipogenesis. While the molecular mechanism of adipogenesis has been extensively studied, its role in dynamic DNA methylation plasticity remains unclear. Recently, it has been shown that Tet methylcytosine dioxygenase (TET) is catalytically capable of oxidizing DNA 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC) toward a complete removal of the methylated cytosine. We investigate whether expression of the Tet genes and production of hydroxymethylcytosine are required for preadipocyte differentiation. SUBJECTS/METHODS: Murine 3T3-L1 preadipocytes were used to evaluate the role of Tet1 and Tet2 genes during adipogenesis. Changes in adipogenic ability and in epigenetic status were analyzed, with and without interfering Tet1 and Tet2 expression using small interfering RNA (siRNA). The adipogenesis was evaluated by Oil-Red-O staining and induced expression of adipogenic genes using quantitative polymerase chain reaction (qPCR). Levels of 5-hmC and 5-mC were measured by MassARRAY, immunoprecipitation and GC mass spectrometry at specific loci as well as globally. RESULTS: Both Tet1 and Tet2 genes were upregulated in a time-dependent manner, accompanied by increased expression of hallmark adipogenic genes such as Pparγ and Fabp4 (P<0.05). The TET upregulation led to reduced DNA methylation and elevated hydroxymethylcytosine, both globally and specifically at the Pparγ locus (P<0.05 and P<0.01, respectively). Knockdown of Tet1 and Tet2 blocked adipogenesis (P<0.01) by repression of Pparγ expression (P<0.05). In particular, Tet2 knockdown repressed conversion of 5-mC to 5-hmC at the Pparγ locus (P<0.01). Moreover, vitamin C treatment enhanced adipogenesis (P<0.05), while fumarate treatment inhibited it (P<0.01) by modulating TET activities. CONCLUSIONS: TET proteins, particularly TET2, were required for adipogenesis by modulating DNA methylation at the Pparγ locus, subsequently by inducing Pparγ gene expression.

S1P lyase inhibition prevents lung injury following high pressure-controlled mechanical ventilation in aging mice.

Ventilator-induced Lung Injury (VILI) is characterized by hypoxia, inflammatory cytokine influx, loss of alveolar barrier integrity, and decreased lung compliance. Aging influences lung structure and function and is a predictive factor in the severity of VILI; however, the mechanisms of aging that influence the progression or increased susceptibility remain unknown. Aging impacts immune system function and may increase inflammation in healthy individuals. Recent studies suggest that the bioactive sphingolipid mediator sphingosine-1-phosphate (S1P) and the enzyme that degrades it S1P lyase (SPL) may be involved in lung pathologies including acute lung injury. It is unknown whether aging influences S1P and SPL expression that have been implicated in lung inflammation, injury, and cell apoptosis. We hypothesized that aging and injurious mechanical ventilation synergistically impair S1P levels and enhance S1P lyase (SPL) expression that amplifies alveolar barrier damage and diminishes pulmonary function. Young (2-3 mo) and old (20-25 mo) C57BL/6 mice were mechanically ventilated for 2 h using pressure-controlled mechanical ventilation (PCMV) at 45 cmH2O and 35 cmH2O, respectively. We assessed the impact of aging and PCMV on several indications of acute lung injury, immune cell recruitment, S1P levels and SPL activity. Furthermore, we evaluated the protective effects of inhibiting SPL by tetrahydroxybutylimidazol (THI) administration on the negative outcomes associated with aging and mechanical injury. PCMV exacerbated lung injury in old mice and increased neutrophil influx that was further exacerbated due to aging. SPL expression increased in the young and old ventilated mice and the old nonventilated group. THI treatment reduced several of the indicators of lung injury and resulted in elevated S1P levels in lung tissue and plasma from mice that were injured from mechanical ventilation. CD80 and CD206 activation markers of alveolar and interstitial macrophages were also influenced by THI. SPL inhibition may be a viable therapeutic approach for patients requiring mechanical ventilation by preventing or regulating the exaggerated inflammatory response and reducing lung injury.

Carnitine status in early-treated children, adolescents and young adults with phenylketonuria on low phenylalanine diets.

BACKGROUND: In patients with phenylketonuria (PKU), the carnitine status may be impaired for metabolic or dietary reasons, including low carnitine intake, a deficient synthesis and acylcarnitine production from phenylalanine (Phe) metabolites. METHODS: Free carnitine and acylcarnitine status was assessed in 30 PKU patients, aged 0.5-36 years, mean age 13.8 years. Our cohort was divided into 2 groups according to the preparations of Phe-free amino acids (AA) prescribed, with or without carnitine supplementation. Daily Phe intake, dosage of AA mixtures and body weight were recorded along with measurements of acylcarnitines in blood spots (by tandem mass spectrometry) and serum AA. Control data were obtained from 50 healthy volunteers (aged 0.2-39 years, mean age 14.2. years). Statistical analysis comprised the t test, ANOVA and Pearson's correlation. RESULTS: PKU patients had lower free carnitine (C0) concentrations than controls (25.82 +/- 7.38 vs. 31.28 +/- 6.17 micromol/l; p < 0.001) and lower octanoyl- and decanoylcarnitine. Mean C0 and acylcarnitine concentrations did not differ between PKU patients taking the various protein substitutes with or without carnitine; mean C0 levels in PKU patients receiving AA enriched with carnitine were still lower compared with controls (p < 0.05). CONCLUSIONS: Actual dietary regimens can not completely normalize the carnitine status; therefore, carnitine levels should be given careful consideration in subjects with PKU.

[Teleradiology and mammography screening: evaluation of a network with dedicated workstations for reporting]. / Teleradiologie im Mammographie-Screening: Evaluation eines Testnetzes mit dedizierten Befundungsstationen.

PURPOSE: Evaluation of a system that supports a workflow for breast cancer screening by mammography. The time of installation, system reliability and workstation operation were evaluated. MATERIALS AND METHODS: The evaluated system (Image Diagnost, Munich, Germany) contains 2 diagnostic mammography workstations, a centralized server, and 2 Dicom shuttles for exchanging images via a physically existing network structure. Temporary archiving is possible. A mask designed for the needs of mammography screening facilitates assignment of BIRADS categories. The system automatically compares the categories assigned by a first and second reviewer and decides whether a consensus conference should be held. In the event that a conference is needed, the reviews are transmitted to the mammography expert responsible for the screening program and the consensus conference. Images are transferred via ISDN, Germany's National Research and Education Network (in the following DFN) and a central server between 2 sites which are approx. 100 km apart. We evaluated the duration of installation, the reliability of the system, and the usability of the workstation. Since we used curative mammography for evaluating the system, the patient age was noted for comparison. RESULTS: The system was installed in five days. Once installed, the system functioned without any major breakdowns. Mammography units of 2 manufacturers were able to be connected to the system without difficulty. Mammographies of 151 patients were exchanged between the sites and evaluated by 2 radiologists. 57 % of the patients were in the screening age (50-69 years). 9 exams were classified BIRADS 4a, 2 were 4b and 3 were BIRADS 5. The evaluations were technically perfect in 146/151 cases; hanging protocols had to be altered manually in 6 cases; the window/level had to be manually adjusted in 26/151 cases. Magnification was sufficient in all cases. The system exchanges examinations extremely quickly; up to 100 mammography exams may be evaluated in 1 hr. CONCLUSION: The system supports the workflow given by the German Mammography Screening program both locally and in a network.

Effects of various dietary amino acid preparations for phenylketonuric patients on the metabolic profiles along with postprandial insulin and ghrelin responses.

AIM: We investigated the metabolic profiles along with insulin and ghrelin responses following ingestion of various amino acid (AA) substitutes commonly used in the treatment of phenylketonuria to study the effects of added macronutrients. METHODS: Twenty healthy and 6 phenylketonuric adults ingested AA mixtures with or without carbohydrates and fat (Anamix, Easiphen, or p-am 3; 0.35 g AA/kg body weight); milk powder shakes were used for control purposes. Serum AA, glucose, urea, insulin, and ghrelin were measured over 5 h. RESULTS: Peak AA concentrations were achieved at around 60 min postprandially for supplemented AA powders and control shakes, significantly later than for pure AA. Of interest, the mean Phe/Tyr ratio declined by 40-50% in phenylketonuric patients following intake of Easiphen, Anamix, or p-am 3. The insulin peaks, up to 500% as compared with baseline, occurred at 30 min and were approximately 100% higher after intake of AA plus macronutrients. Glucose and urea remained constant. Ghrelin showed a nadir at 60 min, followed by a rise leading to a 30% increase of initial concentrations for pure AA as compared with more constant levels for preparations with macronutrients. CONCLUSION: An oral AA bolus together with macronutrients retards hyperaminoacidemia, displays a higher insulin secretion, normoglycemia, and more stable ghrelin concentrations, whereas the pure AA tested here exerted weaker anabolic effects.

IL-10 production by CLL cells is enhanced in the anergic IGHV mutated subset and associates with reduced DNA methylation of the IL10 locus.

Chronic lymphocytic leukemias (CLLs) with unmutated (U-CLL) or mutated (M-CLL) IGHV have variable features of immunosuppression, possibly influenced by those CLL cells activated to produce interleukin 10 (IL-10). The two subsets differ in their levels of anergy, defined by low surface immunoglobulin M levels/signaling capacity, and in their DNA methylation profile, particularly variable in M-CLL. We have now found that levels of IL-10 produced by activated CLL cells were highly variable. Levels were higher in M-CLL than in U-CLL and correlated with anergy. DNA methylation analysis of IL10 locus revealed two previously uncharacterized 'variably methylated regions' (CLL-VMRs1/2) in the gene body, but similarly low methylation in the promoter of both U-CLL and M-CLL. CLL-VMR1/2 methylation was lower in M-CLL than in U-CLL and inversely correlated with IL-10 induction. A functional signal transducer and activator of transcription 3 (STAT3) binding site in CLL-VMR2 was confirmed by proximity ligation and luciferase assays, whereas inhibition of SYK-mediated STAT3 activation resulted in suppression of IL10. The data suggest epigenetic control of IL-10 production. Higher tumor load may compensate the reduced IL-10 production in U-CLL, accounting for clinical immunosuppression in both subsets. The observation that SYK inhibition also suppresses IL-10 provides a potential new rationale for therapeutic targeting and immunological rescue by SYK inhibitors in CLL.

Increased vascular permeability in spontaneously diabetic BB/W rats and in rats with mild versus severe streptozocin-induced diabetes. Prevention by aldose reductase inhibitors and castration.

125I-labeled albumin permeation (IAP) has been assessed in various tissues in spontaneously diabetic insulin-dependent female BB/W rats and in male Sprague-Dawley rats with severe or mild forms of streptozocin-induced diabetes (SS-D and MS-D, respectively). In BB/W diabetic rats and in rats with SS-D, indices of IAP were significantly increased in tissues and vessels predisposed to diabetic vascular disease in humans, including the eyes (anterior uvea, posterior uvea, and retina), sciatic nerve, aorta, kidney, and new vessels formed after induction of diabetes. No evidence of increased IAP was observed in heart, brain, testes, or skeletal muscle in BB/W or SS-D rats. In MS-D rats, indices of IAP were increased only in the kidney and in new vessels formed after the onset of diabetes. Marked tissue differences were observed in the effects of two structurally different aldose reductase inhibitors (sorbinil and tolrestat) and of castration on diabetes-induced increases in IAP and in tissue levels of polyols in SS-D rats. Both aldose reductase inhibitors and castration completely prevented diabetes-induced increases in IAP in new vessels and in sciatic nerve in BB/W and SS-D rats. Both aldose reductase inhibitors also markedly decreased IAP in the anterior uvea (approximately 85%), posterior uvea (approximately 65-75%), retina (approximately 65-70%), and kidney (approximately 70-100%); castration reduced IAP in the anterior uvea (approximately 55%), kidney (approximately 50%), and retina (approximately 30%) but had no effect on the posterior uvea. The diabetes-induced increases in IAP in the aorta were reduced only slightly (approximately 20%) by aldose reductase inhibitors and castration.(ABSTRACT TRUNCATED AT 250 WORDS)

[No detectable nephrotoxic side effect using a dimer, non-ionic contrast media in cerebral perfusion computed tomography in case of suspected brain ischemia]. / Keine nachweisbare Nephrotoxizität eines dimeren nichtionischen Röntgenkontrastmittels bei der notfallmässigen kraniellen Perfusions-Computertomographie.

PURPOSE: In suspected brain ischemia, the perfusion cerebral computed tomography (cCT) should be performed with the lowest amount of contrast media to avoid a contrast media induced nephropathy (CIN) even if the patient already is in renal failure. We were interested to find the best parameters for this examination. MATERIAL AND METHODS: From February 2000 to March 2003, 138 patients (58 females, 80 males, mean age 66.8 years) underwent cCT-perfusion immediately after the admission to our stroke unit. Of these patients, 62% (n = 86) had normal renal function and 38% (n = 52) renal failure (up to 381 micromol/l basic serum creatinine). We varied volume (20-80 ml), flow (5 vs. 7.2 ml/s) and concentration (270 vs. 320 ml/mg iodine) of a dimer, non-ionic contrast media (Visipaque) to establish 5 groups. So we got patients receiving 6 g, 12 g, 16 g, 19 g and 25 g of iodine. After generating the perfusion maps, two radiologists reviewed the quality of the maps and scored it (1-5). We measured the serum creatinine before contrast application and at follow up cCT (days 3 and 7). RESULTS: The quality of the maps increases with increasing amount of iodine. However, the diagnostic result was not significantly better using more than about 16 g of iodine (e. g., 60 ml--7.2 ml/s--270 mg/ml) in cCT-perfusion studies. Only one patient had a pathologic increase in serum creatinine (day 1: 93; day 4: 146 micromol/l) but died at day 5 because of massive co-morbidity and septic pneumonia. No CIN occurred even in the patient group with pre-existent renal failure. CONCLUSIONS: About 60 ml contrast media and a moderate flow rate of about 7 ml/s ensure good results in perfusion-cCT, even if the patients have poor blood circulation or arteriosclerosis. The use of a dimer, non-ionic contrast media (range of 6-25 g iodine) seems to minimize the risk of CIN in the daily routine.

[Laser-induced thermotherapy (LITT) of tumors of the liver in central location: results and complications]. / Laserinduzierte Thermotherapie (LITT) von Lebertumoren in zentraler Lokalisation: Ergebnisse und Komplikationen.

PURPOSE: To investigate whether laser-induced thermotherapy (LITT) for tumors of the liver in central location is a sufficient and safe therapeutic option. MATERIAL AND METHODS: According to predefined criteria, 23 of 136 patients were chosen to be treated with LITT because of malignant liver tumors. At the time of the first LITT, the patients had 28 central tumors (27 metastases, one HCC), which were treated in 34 sessions with 64 laser applications and had a clinical and imaging follow-up every 3 months. RESULTS: The primary effectiveness rate was 74.1% and the secondary effectiveness rate 82.1%. The mortality rate was 0%. Major complications occurred in one patient (hemorrhagic pleural effusion), while minor complications occurred in 10 patients. During the median follow-up of 20 months (range 3-57 months), local tumor progression developed in 22% of the tumors. The effectiveness rate was 78.6%, 71.4% and 64.3% after 3, 6 and 9 months. The median survival was 46.0 months (95% confidence interval: 28.6-47.1 months). CONCLUSION: In our patients, complications and ablation rate of laser-induced thermotherapy for central liver tumors do not differ from those in peripheral location as described in the literature.

Epigenetics in radiation-induced fibrosis.

Radiotherapy is a major cancer treatment option but dose-limiting side effects such as late-onset fibrosis in the irradiated tissue severely impair quality of life in cancer survivors. Efforts to explain radiation-induced fibrosis, for example, by genetic variation remained largely inconclusive. Recently published molecular analyses on radiation response and fibrogenesis showed a prominent role of epigenetic gene regulation. This review summarizes the current knowledge on epigenetic modifications in fibrotic disease and radiation response, and it points out the important role for epigenetic mechanisms such as DNA methylation, microRNAs and histone modifications in the development of this disease. The synopsis illustrates the complexity of radiation-induced fibrosis and reveals the need for investigations to further unravel its molecular mechanisms. Importantly, epigenetic changes are long-term determinants of gene expression and can therefore support those mechanisms that induce and perpetuate fibrogenesis even in the absence of the initial damaging stimulus. Future work must comprise the interconnection of acute radiation response and long-lasting epigenetic effects in order to assess their role in late-onset radiation fibrosis. An improved understanding of the underlying biology is fundamental to better comprehend the origin of this disease and to improve both preventive and therapeutic strategies.

Cloning, sequencing, and heterologous expression of a cellulase-encoding cDNA (cbh1) from Penicillium janthinellum.

From a Penicillium janthinellum cDNA library, two clones with 1.8- and 1.9-kb inserts were isolated by hybridization to a Trichoderma reesei cellulase-encoding gene probe (egl1). Both cDNAs have identical 5' ends and coding sequences, but different polyadenylation start points in their 3' untranslated regions. In the nucleotide (nt) sequence, one open reading frame of 537 amino acids was detected which shows 56% homology with endoglucanase I of T. reesei and 70% homology with cellobiohydrolase I of T. reesei, Phanerochaete chrysosporium, and Humicola grisea. Expression of the 1.9-kb cDNA in the Escherichia coli T7 system led to the detection of a 57-kDa protein, in agreement with the theoretical value. Fusion to the promoter of the yeast phosphoglycerokinase-encoding gene led to efficient expression and partial secretion of the cDNA-encoded cellulase with cellobiohydrolase I activity in Saccharomyces cerevisiae.

Bacterial replication initiator DnaA. Rules for DnaA binding and roles of DnaA in origin unwinding and helicase loading.

We review the processes leading to the structural modifications required for the initiation of replication in Escherichia coli, the conversion of the initial complex to the open complex, loading of helicase, and the assembly of two replication forks. Rules for the binding of DnaA to its binding sites are derived, and the properties of ATP-DnaA are described. We provide new data on cooperative interaction and dimerization of DnaA proteins of E. coli, Streptomyces and Thermus thermophilus, and on the stoichiometry of DnaA-oriC complexes of E. coli.

Functional domains of DnaA proteins.

Functional domains of the initiator protein DnaA of Escherichia coli have been defined. Domain 1, amino acids 1-86, is involved in oligomerization and in interaction with DnaB. Domain 2, aa 87-134, constitutes a flexible loop. Domain 3, aa 135-373, contains the binding site for ATP or ADP, the ATPase function, a second interaction site with DnaB, and is required for local DNA unwinding. Domain 4 is required and sufficient for specific binding to DNA. We show that there are three different types of cooperative interactions during the DNA binding of DnaA proteins from E. coli, Streptomyces lividans, and Thermus thermophilus: i) binding to distant binding sites; ii) binding to closely spaced binding sites; and iii) binding to non-canonical binding sites.

Oxygenation of squamous cell carcinoma of the head and neck: comparison of primary tumors, neck node metastases, and normal tissue.

BACKGROUND: Most previous oxygenation measurements of head and neck tumors have mainly been performed in neck nodes. We investigated, therefore, the relationship between the pO2 status of primary tumors, cervical neck node metastases and normal tissues. PATIENTS AND METHODS: 30 patients with histologically proven advanced stage III-IV squamous cell carcinoma of head and neck underwent pretreatment polarographic pO2 measurements with a pO2 histograph (Eppendorf, Hamburg, Germany). We obtained data on oxygenation of 23 primary tumors, of 22 neck node metastases, and of 30 contralateral sternocleidomastoid muscles. In 15 cases, we were able to perform measurements in all three regions in the same individual. results: A highly significant correlation existed between the median pO2 of primary tumors and their neck node metastases (p=0.0001), as well as between the proportion of pO2 values < or =2.5 mmHg and +/-5.0 mmHg (p=0.0001, p=0.001) in both anatomic sites. The average pretreatment median PO2 was 14.7 mmHg (range 0.2-58.5 mmHg) in primary tumors, 13.7 mmHg (range 1.9-50.3 mmHg) in neck node metastases, and 43.8 mmHg (range 20.8-67.7 mmHg) in sternocleidomastoid muscles. In all cases, the oxygenation of malignant tissue was below that of the corresponding muscle. There was also a weak, but significant, correlation between hemoglobin level and the median pO2 of the primary tumors, as well as between hemoglobin concentration and the proportion of values below 5 mmHg at the primary site (p=0.017, p=0.003). CONCLUSIONS: Primary tumors and their regional lymph node metastases in advanced squamous cell carcinoma of the head and neck show comparable patterns of oxygenation in terms of the median pO2 and the proportion of hypoxic measurements. This report suggests that, in patients with such carcinomas, the oxygenation data obtained at one site are related to tumor oxygenation at other sites, so that measurements in any anatomic site would be sufficient to estimate a tumor's oxygenation status. The weak correlation between pO2 and hemoglobin level requires further investigation.

Increased ocular blood flow and 125I-albumin permeation in galactose-fed rats: inhibition by sorbinil.

125I-Albumin permeation and blood flow (assessed with 15 micron, 85Sr-labelled microspheres) were determined in the retina, choroid, anterior uvea, and brain of male Sprague-Dawley rats fed diets containing 50% dextrin (control) or 50% galactose. Blood flow was increased in the retina, choroid, and anterior uvea but not in the brain of rats fed galactose for 3 weeks and 3 months versus controls, and was normalized by sorbinil (an inhibitor of aldose reductase) in the 3-week group. After 8 months of galactose feeding, blood flow was reduced to normal levels in the retina and was slightly below normal in the choroid; blood flow remained elevated in the anterior uvea but was significantly lower than that observed at 3 weeks and at 3 months. In rats fed galactose for 8 months, sorbinil completely normalized blood flow in the choroid, and decreased, but did not normalize, blood flow in the anterior uvea. 125I-Albumin permeation was increased in the retina, choroid, and anterior uvea of rats fed 50% galactose for 3 weeks, 3 months, and 8 months versus controls, but was unchanged in the brain. Sorbinil normalized 125I-albumin permeation in all three ocular tissues in 8-month galactose-fed rats. Polyol levels were increased significantly in all three ocular tissues of 3-week galactose-fed rats; sorbinil markedly decreased, but did not normalize, polyol levels in all three tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Transcriptional regulation of gene expression of sec6, a component of mammalian exocyst complex at the synapse.

Sec6, an essential component of the mammalian brain exocyst complex, is believed to function in synapse formation and synaptic plasticity. During neuronal development, the expression of the Sec6 gene correlates temporally with neurite outgrowth and synaptogenesis. To understand the mechanisms that regulate the Sec6 gene expression, we have cloned and characterized the 5'-terminal region of the murine Sec6 gene. We have shown that the 5'-untranslated region of the murine Sec6 gene is encoded by two exons that are separated by a 1560-bp intron. Primer extension analysis demonstrates that Sec6 gene transcription is initiated from a unique site. The Sec6 promoter is embedded in a CpG island and lacks canonical TATA or CAAT boxes. Sequence analysis of the 5'-flanking region and the first intron reveals the presence of a number of binding sites for transcription factors AP-1, AP-2, AP-4, ATF, C/EBPbeta, GATA-1, Oct 1, SP1, STAT, and NRSF. Transfection experiments using Sec6-luciferase fusion genes demonstrate that the 5'-flanking sequence functions as a strong promoter in neuronal but not in nonneuronal cells. Deletion analysis reveals the presence of a core promoter between nucleotide position -139 and +53, and two enhancer and four silencer elements within the 5'-flanking region and the first intron sequence. These results indicate that neuronal expression of the Sec6 gene involves a relatively specific core promoter and interplay between multiple positive and negative regulatory elements.

Perceptions of control, competence, and contingency as influences on the stress-behavior symptom relation in school-age children.

Analyzed data from 154 school-age children and their mothers to examine the relations between stress, perceived competence and contingency, and behavior symptoms. Analyses focused on the relative merits of unidimensional vs multidimensional measures of control in predicting symptoms. The stress of undesirable life events and behavior symptoms were related in the expected direction. Multiple regression models with R2 ranging from .11 to .14 (all ps less than .0002) included significant main effects for stress, competence, and control. Analyses supported the relative superiority of the multidimensional measure of control. Models containing main effects and interaction terms were of equivalent magnitudes in accounting for variance in symptom scores. Findings support the idea of perceived control as a moderator of the stress-illness relation and are consistent with earlier suggestions that simple main effects models may be the most useful in examining these relations.

Successful bone fill in late peri-implant defects using guided tissue regeneration. A short communication.

Severe loss of peri-implant supporting bone traditionally leads to the removal of the affected implant, but this may not be necessary in all cases. This paper presents a novel treatment approach aimed at the successful regeneration of bone lost to peri-implantitis using guided tissue regeneration (GTR). Four years after implant placement two patients presented with severe peri-implant tissue breakdown. Clinical signs of disease included bleeding on probing, suppuration, increased probeable pocket depth (4 to 9 mm) and a decreased level of clinical attachment (2 to 10 mm). Radiographic analysis revealed 2.6 to 7.1 mm loss of supporting bone. Treatment of these lesions included raising flaps, wound debridement, and rinsing with sterile saline and 0.2% chlorhexidine digluconate. Subsequently, ePTFE membranes were adapted around the necks of the implants and the flaps sutured around the necks of the implants, allowing for transmucosal healing. Both patients were placed on a 10-day antibiotic regimen and instructed to rinse twice daily with a 0.12% chlorhexidine solution. They were reevaluated every 3 weeks at which time professional plaque control was performed. After 4 1/2 and 6 1/2 months, respectively, the membranes required removal due to infection. The radiographic analysis 1 year after membrane removal revealed 1.5 to 3.6 mm of bone gain. As a result of regenerative therapy the implants in both these patients were successfully maintained. It can be concluded that implants with severe loss of bone resulting from peri-implantitis need not always be extracted. A potential approach for the treatment of peri-implant bone destruction is GTR therapy using strict attention to good antimicrobial therapy.

[Laser-induced thermotherapy (LITT) of lung metastases: description of a miniaturized applicator, optimization, and initial treatment of patients]. / Laser-induzierte Thermotherapie (LITT) von Lungenmetastasen: Beschreibung eines miniaturisierten Applikators, Optimierung und erste Patientenbehandlungen.

PURPOSE: A thin-caliber applicator system was developed for introducing a laser fiber under CT guidance into lung metastases with only minimal complications. MATERIALS AND METHODS: A space-saving 5.5 French Teflon cannula with a titanium trocar and connectors for a laser light guide (2 or 3 cm Dornier Diffusor-Tip H-6111-T2 or H-6111-T3 coupled to a Dornier Medilas Fibertom 5100 laser, wavelength of 1064 nm) and a perfusion line for physiologic saline solution were developed. After puncture the laser Diffusor-Tip remains in the cannula and is cooled during its tissue passage by slowly flowing saline solution. The miniaturized applicator system (Monocath) was calibrated in nonperfused bovine liver for maximum energy supply and necessary flow of the cooling saline solution in reference to a commercially available 9 French laser catheter with an 11.5 French inducer sheath (Power-Applicator). The new applicator system was used for treating lung metastases in 10 patients over a period of 21 months. RESULTS: The size of heat coagulation in bovine liver was 24 +/- 2 ml using the miniaturized system with application of 15 W for 20 min and a saline flow of 0.75 ml/min, in comparison to a size of 29 +/- 7 ml for the commercial applicator (30 W, 20 min, 60 ml/min). All metastases could be safely approached with the miniaturized applicator, except for two metastatic lesions at the lung base in two patients. A minor pneumothorax developed in three patients and intrapulmonary bleeding in two. Contrast-enhanced CT demonstrated necrosis of the treated metastatic areas in 6 patients. Follow-up of three patients after 5, 6, and 8 months showed complete tumor regression with minimal scarring in one patient. CONCLUSION: The miniaturized applicator system enables the introduction of a laser fiber into pulmonary metastases with only minor complications. Complete ablation seems to be achievable in suitable patients with the applied laser energy and a slow cooling fluid flow rate.

Sex- and age-linked determinants of physical activity in adulthood.

One barrier to increasing participation rates among Canadian adults is limited knowledge concerning the determinants of regular physical activity. 382 volunteers (aged 16-82) completed a questionnaire examining current exercise behaviour and beliefs, as well as developmental influences on participation. Although the sexes were similar in overall activity level, differences in preferred activities, influence of marriage and parenthood, and personal motives for exercising, indicate fitness promotion efforts should be sex-specific. Fitness-related messages should also be age-related, based on the findings that activity preferences and influences on participation varied with life stage. The present findings support the assumption that adulthood participation is related to skill acquisition and positive experiences during youth. Specific directions for fitness promotion and further research were suggested.