Biomedical subjects

Jürgen Hedderich

Publications and source records attributed to Jürgen Hedderich.

At least 19 recordsLinked to original sources

PubMed2006

Glioblastoma--the consequences of advanced patient age on treatment and survival.

Glioblastoma is the most common primary brain tumor. Recent evidence suggests that aggressive treatment is also effective in elderly patients. However, large patient series are missing. The aim of this retrospective study was to determine prognostic factors in a large series (n=345) of elderly patients surgically treated for newly diagnosed glioblastoma (WHO grade IV) at a single institution between 1991 and 2002. U-tests (Mann Whitney), chi-square tests, log-rank tests/Kaplan-Meier plots and Cox regression models were used for statistical analysis. Based on the maximum difference in median survival, a threshold of 60 years was used to separate younger from older patients. In total, 185 patients (53.6%) were over 60 years old. In these individuals, total tumor resection, radiotherapy and reoperation for tumor recurrence were identified as independent prognostic factors. When total surgical resection was combined with radiotherapy and reoperation, Kaplan-Meier analysis revealed a median survival of up to 64 weeks in elderly patients. Our data indicate that total tumor resection, radiotherapy and reoperation should also be considered in selected elderly patients. Age alone should not generally exclude elderly individuals from aggressive treatment.

Adult↗

PubMed2006

Influence of various cell-detachment solutions on endothelial cells after catheter abrasion for prosthesis colonization prior to implantation.

We (1) evaluated the effectiveness of different media on the detachment of endothelial cells (ECs) from a catheter brush (Cragg thrombolytic catheter system) that was previously used for endothelial cell abrasion in 10 cm human umbilical vein (HUV) segments; (2) tested the practicability of endovascular catheter brush abrasion followed by EC detachment from the catheter brush, in vitro culture of harvested ECs, and finally endothelialization of a prosthesis; and (3) analyzed the defect created by the catheter brush in HUV segments after endovascular catheter abrasion. Best results in detachment of ECs from the catheter brush were obtained with a mixture of phosphate-buffered saline + 1% human albumin. EC vitality was time-dependent in the collected HUV segments postdelivery. Harvested EC viability decreased from (26.28 +/- 5.76)% (0-3 h postdelivery) to (17.29 +/- 4.56)% (after 4-8 h). ECs were easily cultured ex vivo within 2-3 weeks; seeded on nitinol stents, they grew to confluency and formed a monolayer on the stent surface (determined by scanning electron microscopy - SEM). Histological and SEM analysis of HUV segments that had undergone previous catheter brush abrasion revealed slight disruption of the intima but intact subintimal layers. Our findings indicate an advantageous method of capturing and culturing primary ECs for gene therapy or for the analysis and diagnosis of certain blood vessel diseases, especially in cases in which endovascular intervention is performed anyway. Moreover, and of high relevance to the biomaterial field, theoretically the procedure could be used to endothelialze a prosthesis ex vivo for implantation into the patient from whom the ECs were harvested, to reduce the inherent thrombogenicity of the prosthesis.

Catheter Ablation↗

PubMed2006

Gastric emptying time of fluids and solids in healthy subjects determined by 13C breath tests: influence of age, sex and body mass index.

BACKGROUND AND AIM: Disturbance of gastric emptying leads to a variety of symptoms. Furthermore, gastric motility disorders might play a role in the pathophysiology of functional dyspepsia. In previous studies 13C breath tests were validated as non-invasive tools in the measurement of gastric emptying time. So far, reliable reference values of healthy subjects are missing and the impact of constitutional traits (age, sex, body mass index [BMI]) needs to be clarified. METHODS: A study was conducted in 90 healthy individuals (45 men, 45 women) that assessed the correlation of parameters of gastric emptying (half gastric emptying time [T1/2] and time of fastest gastric emptying [T(lag)]) with age, sex and BMI for fluid and solid test meals by 13C breath tests. 100 mg of sodium acetate or sodium octanoate, respectively, were used as tracers. Breath probes were analyzed by non-dispersive infrared spectroscopy. RESULTS: The mean +/- SD of half gastric emptying time (T1/2) of a fluid test meal was determined to be 80.5 +/- 22.1 min and for T(lag) to be 40.3 +/- 10.2 min. However, the T1/2 and T(lag) of solid meals did not fit to normal distribution and thus median and percentiles were determined. The median time of T1/2 for solids was 127 min (25-75% percentiles: 112.0-168.3 min) and 81.5 min for T(lag) (25-75% percentiles: 65.5-102.0 min). No significant correlation was found between gastric emptying and age, sex or BMI. CONCLUSION: This is the first study to examine gastric emptying in an adequate number of healthy subjects by 13C breath tests. No significant correlation was found with age, sex and BMI. Although there is considerable standard deviation in gastric emptying time, these results may nevertheless serve as reference values for further studies.

Age Factors↗

PubMed2006

Focal adhesion contact formation by fibroblasts cultured on surface-modified dental implants: an in vitro study.

A major consideration in designing dental implants is to create a surface that provides strong attachment of the implant to bone, connective tissue and epithelium. The aim of the present study was to examine the influence of different treatments of titanium (Ti) implant surfaces on focal adhesion contact (FAC) formation in fibroblast cultures. Human gingival fibroblasts were cultured on glass sheets and polished Ti discs with different surface coatings (applied by physical vapor deposition (PVD): Ti, titanium nitride (TiN), zirconium nitride (ZrN)) or on Ti discs with different surface topographies. For characterization of all surfaces, modified estimation of surface roughness and spacing parameter was carried out using a contact stylus profilometer. Contact angle measurements were carried out to calculate surface energy. Fibroblasts were prepared for transmission electron microscopy at day 3 after seeding, and the number of FACs and the ratio FAC/cellular cross-sections was determined at a length of 300 microm in ultrathin sections. To visualize the extracellular fibronectin and vitronectin molecules and the intracellular actin and vinculin in FAC areas, immunogold labeling was performed. The results revealed a strong correlation between the number of FACs and the surface roughness. The highest number of FACs and the majority of the immunogold-labeled intra- and extracellular matrix molecules were counted on surfaces with the lowest surface roughness: glass sheets coated with either Ti, TiN or ZrN (roughness average=0.03-0.1 microm). These surfaces appear to favor cellular attachment of human gingival fibroblasts and moreover in previous studies the hard coatings have been shown to reduce bacterial adhesion.

Analysis of Variance↗

PubMed2006

Prevalence of dental caries and periodontal disease in patients with inflammatory bowel disease: a case-control study.

AIM: Previous reports suggest a higher incidence of dental caries in patients with inflammatory bowel disease (IBD) and similarities in the immunopathogenesis of IBD and periodontitis. This study assessed the prevalence of periodontal disease and caries in patients with IBD. METHODS: In the present case-control study, 62 patients seeking treatment of IBD and 59 matched healthy controls of a dental practice were clinically examined. Oral soft-tissue alterations, the decayed, missing and filled tooth surface (DMF-S) index, dentine caries, plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment loss (CAL) were evaluated in each patient and in the controls. RESULTS: Patients with IBD showed a significantly higher number of oral manifestations compared with controls. The DMF-S index showed no significant differences, but there was a significantly higher number of subjects with dentine caries in patients with IBD. The mean PPD in patients with IBD was 2.08 versus 2.23 mm in controls (p=0.014). Compared with controls, patients with IBD had more sites with CAL of at least 4 mm (81% versus 64% in controls, p=0.07) and 5 mm (63% versus 46%, p=0.07), respectively. CONCLUSIONS: The results of this case-control study demonstrate a higher frequency of dentine caries in patients with IBD but the periodontal findings showed no distinct differences between cases and controls.

Adult↗

PubMed2005

The mechanical integrity of in vivo engineered heterotopic bone.

Recent advances in tissue engineering have aroused interest in growth of heterotopic bone for the repair of skeletal defects. This study demonstrates an in vivo method in minipigs of engineering individual human-sized mandible replacements of heterotopic bone with a mechanical integrity similar to natural bone. Ten individualized mandible replacement scaffolds were created using computer-aided design (CAD) techniques. Five had a resorbable external scaffold made of polylactite mesh (test group 1) and five had had a non-resorbable external scaffold of titanium mesh (test group 2). The mesh scaffolds were loaded each with five BioOss blocks serving as internal scaffolds and 3.5 mg recombinant human Bone Morphogenetic Protein-7. The loaded mesh scaffolds were implanted into the latissimus dorsi muscles of five infant minipigs. After 6 weeks the mandible replacements were harvested. Core biopsy cylinders were taken from the replacements of both test groups and from the natural pig mandibles (control 1). Also, core biopsies from plain BioOss Blocks were gained (control 2). The core biopsy cylinders were loaded axially into a compression test device to evaluate the mechanical compression resistance. Additional specimen underwent histological examination. Both test groups resulted in successful bone induction with degrees of compression resistance [Test 1: 1.62 MPa (SD+/-0.73); Test 2: 1.51 MPa (SD+/-0.56)] statistically insignificant when compared to natural porcine mandibular bone [1.75 MPa (SD+/-0.69)]. This differed significantly from the much lower compression resistance seen in the unadulterated BioOss [0.92 MPa (SD+/-0.04)]. Following this, the in vivo engineered bone has a similar mechanical compression stability as natural bone.

Animals↗

PubMed2005

A controlled prospective case control study of a prevention training program in female team handball players: the German experience.

BACKGROUND: Few authors have investigated the effectiveness of preventive intervention in European team handball. PURPOSE: The aim of the present study was to evaluate the effects of a prevention program on the incidence of injuries in female European team handball players. STUDY DESIGN: Prospective controlled study. METHODS: Ten female handball teams (134 players) took part in the prevention program (1. Information about injury mechanism, 2. Balance-board exercises, 3. Jump training) while 10 other teams (142 players) were instructed to train as usual. Over one season all injuries were documented weekly. RESULTS: Ankle sprain was the most frequent diagnosis in both groups with 11 ankle sprains in the control group and 7 ankle sprains in the intervention group (Odds ratio: 0.55, 95% confidence interval: 0.22-1.43). The knee was the second frequent injury site. In the control group 5 of all knee injuries were anterior cruciate ligament (ACL) ruptures (incidence: 0.21 per 1000 h) in comparison with one in the intervention group (incidence: 0.04 per 1000 h). Odds ratio was 0.17 with 95% confidence interval of 0.02-1.5. CONCLUSIONS: This study confirms that proprioceptive and neuromuscular training is appropriate for the prevention of knee and ankle injuries among female European team handball players.

Adult↗

PubMed2005

Midterm follow-up after minimally invasive direct coronary artery bypass grafting versus percutaneous coronary intervention techniques.

BACKGROUND: Revascularization of the left anterior descending coronary artery can be performed by minimally invasive direct coronary artery bypass grafting (MIDCAB) or percutaneous coronary intervention techniques (PCI). The study compared the midterm results of both techniques. METHODS: The outcome of 206 consecutive MIDCAB and 256 PCI patients treated from 1998 until 2001 was retrospectively analyzed. Cardiologists determined the primary patient allocation for the distinct revascularization technique. Periprocedural complications and midterm follow-up, including quality-of-life assessment (SF-36), was reported up to 5.2 years (3.4 +/- 0.7 years). RESULTS: Periprocedural and overall mortality (p = 0.206) showed no differences. Four MIDCAB patients required early reoperation but not for repeated target vessel revascularization. In 16 patients secondary PCI (7.8%) of other coronary vessels was performed. Repeated revascularization of the left anterior descending coronary artery was necessary in 24.2% of patients in the PCI group (p < 0.001), with 4.7% finally requiring surgical revascularization. The incidence of major adverse cardiac events, including myocardial infarction (p = 0.581), repeated target vessel revascularization (p < 0.001), or death (p = 0.206) was higher in the PCI group. This difference consisted basically of the need for repeated target vessel revascularization. Patient-based quality-of-life assessment (SF-36) was independent from the primary chosen revascularization method. CONCLUSIONS: At midterm follow up, MIDCAB resulted in significantly superior results regarding the need for repeated target vessel revascularization compared with PCI, with no significant differences regarding other major cardiac events.

Adult↗

PubMed2005

2005 Dr. Gary J. Becker Young Investigator Award: periprocedural oral administration of the leflunomide analogue FK778 inhibits neointima formation in a double-injury rat model of restenosis.

PURPOSE: To test the efficacy of limited oral administration of the new leflunomide analogue FK778 for suppression of neointima proliferation in a double-injury restenosis model in the rat. MATERIALS AND METHODS: For induction of aortic lesions, silicon cuffs were placed operatively around the infrarenal aortas of Lewis rats. After 21 days, the aortic cuffs were removed and the lesions were dilated with 2-F Fogarty catheters inserted via the left common carotid artery. The novel immunosuppressant FK778 was administered at a dose of 5 mg/kg body weight (group 1) or 15 mg/kg body weight (group 2) in a total of 38 animals. For both doses, three different periinterventional time periods, each with a 5-day course of oral FK778, were defined as follows: (i) days -2 to 2, (ii) days 1-5, and (iii) days 7-11, with six or seven rats in each group. After 3 weeks, intima/media ratios were assessed morphometrically and immunohistochemistry for quantification of intimal alpha-actin expression was performed. RESULTS: In both dose groups, there was a trend toward inhibition of neointima formation when the 5-day course of FK778 was started before or 1 day after the intervention. However, in the lower-dose group, inhibition of neointima was not statistically significant regardless of the time frame of treatment (groups 1a-c). With the higher dose, suppression of intimal hyperplasia was significant when FK778 was administered between days 1 and 5 after angioplasty (group 2b; P<.01). Expression of alpha-actin in the intima of FK778-treated rats was significantly reduced when the drug was started 2 days before angioplasty in group 1a (P<.05) or 1 day after angioplasty in both dosage groups (group 1b, P<.01; group 2b, P<.05). CONCLUSION: In the double-injury rat model presented, balloon-mediated proliferation of smooth muscle cells in the intima with consecutive intimal thickening was influenced by FK778 in a dose-dependent manner. However, long-term studies are needed to exclude a delay of vascular healing in this particular model.

Actins↗

PubMed2005

Vessel wall damage caused by cerebral protection devices: ex vivo evaluation in porcine carotid arteries.

PURPOSE: To determine the extent of vessel wall damage caused by cerebral protection devices designed for carotid angioplasty by using ex vivo porcine carotid arteries. MATERIALS AND METHODS: The local animal experimentation committee did not require its approval for this study. With a benchtop vascular model (flow rate, 470 mL/min; dicrotic pulsatile flow, 76 pulses per minute; pressure, 115/67 mm Hg [mean pressure, 91 mm Hg]) into which 85 porcine internal carotid arteries (ICAs) were inserted, five different protection devices (Angioguard [Cordis/Johnson & Johnson, Miami, Fla], Filterwire EX [Boston Scientific, Natick, Mass], Trap [Microvena, White Bear Lake, Minn], Neuroshield [Abbott Laboratories, Redwood City, Calif], and Percusurge [Abbott Laboratories]) were evaluated. Adverse movement (1 cm up, 2 cm down, and 1 cm up again) of the activated devices (deployed filters or inflated balloons [Percusurge only]) was simulated, and the device was retrieved. For each of these steps (deployment, movement, retrieval) the amount of debris from the vessel wall in the effluent of the ICA was determined by using a 100-microm filter. The Mann-Whitney test was used to test for differences, and a correction for multiple comparisons was made. P < .05 was considered to indicate a significant difference. The authors attempted to determine whether there was a notable association between the total amount of debris captured and the classification of damage at microscopy. Carotid arteries were analyzed histologically with light and scanning electron microscopy. RESULTS: All examined protection devices caused dislodged debris, which was captured in the effluent filter. There were significant differences among the devices in terms of the total amount of debris captured in the filters (lowest amounts of debris, 4.75 mg [Angioguard] and 5.02 mg [Filterwire EX]; highest amount, 7.51 mg [Trap]; P < or = .001 for all). All devices caused histologically visible wall damage, with the degree of intimal denudation correlating with the mass of the debris. The Trap device caused the most severe intimal and subintimal wall damage. Adverse movement resulted in no increased debris dislodgment as compared with the debris dislodged during deployment and retrieval of the devices. CONCLUSION: On the basis of the data obtained, cerebral protection devices themselves have a potential influence on embolization rates by causing debris to be dislodged during carotid stent placement.

Angioplasty, Balloon↗

PubMed2004

Biomechanical evaluation of a new cross-pin technique for the fixation of different sized bone-patellar tendon-bone grafts.

To overcome the disadvantages of interference-screw fixation of bone-patellar tendon-bone (BPTB) grafts, new fixation techniques for anterior cruciate ligament (ACL) grafts using biodegradable pins have been developed. The hypothesis of the present study was that cross-pin fixation techniques provide a primary stability that is comparable to that of interference screws. A biomechanical in vitro study was discussed. Human BPTB grafts of 8, 9 and 10 mm diameter were fixed in bovine knees with biodegradable cross pins (diameter: 2.0, 2.7 or 3.2 mm) or biodegradable interference screws. Stiffness and ultimate load were evaluated. For 9 and 10 mm BPTB grafts, no statistically significant difference in maximum load and stiffness was found between the four fixation techniques tested. For 8 mm bone blocks the maximum load of the 3.2 mm pins (274.2 N) was significantly lower than for the 2.0 mm pins (479.8 N) and the interference screws (504.0 N). Predominant failure mode in this group was bone-block fracture. Thicker grafts (9 and 10 mm) fixed with the 2.0 mm pins predominantly failed by implant fracture. Femoral fixation of 8, 9 and 10 mm BPTB grafts using cross pins leads to biomechanical properties that are comparable to biodegradable interference screws when tested by a single-cycle load to failure. Cross pins provide a rigid fixation for 9 and 10 mm BPTB grafts.

Absorbable Implants↗

PubMed2004

Detection of granulocyte colony-stimulating factor and its receptor in human follicular luteinized granulosa cells.

OBJECTIVE: To evaluate concentration of granulocyte colony-stimulating factor (G-CSF) in serum and follicular fluid (FF) at the time of oocyte retrieval and to detect expression of G-CSF and its receptor by luteinized granulosa cells (GCs). DESIGN: Collection of serum and FF at the time of oocyte retrieval. SETTING: A university IVF-ICSI program. PATIENT(S): Serum and FF were obtained from 82 women undergoing oocyte retrieval. INTERVENTION(S): Serum and FF were obtained from 82 women. Granulosa cells were pooled from 15 patients (three experiments with five patients each; 3-14 oocytes each). MAIN OUTCOME MEASURE(S): Granulocyte colony-stimulating factor concentration was determined by ELISA, the expression of G-CSF, and its receptor by the immunocytochemical technique and reverse transcriptase polymerase chain reaction analysis. Additionally, G-CSF expression was investigated by cell culture time course studies. RESULT(S): The median G-CSF level in FF (117.98 pg/mL) was significantly higher than that in serum (67.5 pg/mL). Granulocyte colony-stimulating factor and its receptor were expressed by GCs. CONCLUSION(S): The significantly higher level of G-CSF in FF than in serum and the expression of G-CSF and its receptor in FF by GCs suggest an important role for this growth factor in ovarian function.

Adult↗

PubMed2004

Comparison of esophageal Doppler, pulse contour analysis, and real-time pulmonary artery thermodilution for the continuous measurement of cardiac output.

OBJECTIVE: Continuous measurement of cardiac output (CCO) is of great importance in the critically ill. However, pulmonary artery thermodilution has been questioned for possible complications associated with right heart catheterization. Furthermore, measurements are delayed in the continuous mode during rapid hemodynamic changes. A new pulmonary artery catheter CCO device (Aortech, Bellshill, Scotland) enabling real-time update of cardiac output was compared with 2 different, less-invasive methods of CCO determination, esophageal Doppler and pulse contour analysis. DESIGN: Prospective, observational study. SETTING: University hospital, single institution. PARTICIPANTS: Patients scheduled for elective coronary artery bypass grafting (CABG). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: CCO measurements were analyzed using a Bland-Altman plot. Bias between CCO and pulse contour cardiac output (PCCO), and Doppler-derived cardiac output (UCCO) was (mean +/- 1 SD) -0.71 +/- 1 L/min versus -0.15 +/- 1.09 L/min, and between UCCO and PCCO -0.58 +/- 1.06 L/min. Bias was not significantly different among methods, nor were comparative values before and after cardiopulmonary bypass (p > 0.05). CONCLUSIONS: Agreement between the CCO method and both less-invasive measurements was clinically acceptable. There were no adverse events associated with the use of either device.

Aged↗

PubMed2004

Particulated bone grafts--effectiveness of bone cell supply.

OBJECTIVE: The objective of this study was to measure the amount of viable bone cells present in different types of bone graft. MATERIAL AND METHODS: Bone chips were harvested from the trabecular or cortical bone of the mandible or the iliac crest and either milled or not. The average size of unmilled bone particles was 5 x 5 x 5 mm and that of milled was 2 x 2 x 2 mm. Drill sludge was obtained using either a ball reamer, a diamond ball or an implant drill (the latter from mandibular bone and of average dimension 1 x 1 x 1 mm). A measure of 0.5 g of each category was cultured in Dulbecco's modified Eagle's medium with additives for four weeks. Cell counts were performed. An analysis of the osteocalcin synthesis, the alkaline phosphatase (ALP) activity, the collagen types and the concentration of bone-specific collagen cross-links in medium supernatants was performed. RESULTS: Cells stained positively for osteocalcin and ALP in all groups. Bone-specific collagen cross-links could be quantified and collagen of types I and V was present with no difference in all groups. Unmilled spongy bone chips revealed greater cell counts than milled (P<0.05). Spongy bone chips revealed greater cell counts than cortical bone chips (P<0.05). Drill sludge obtained by hard alloy ball reamer showed the least amount of viable cells (P<0.05). CONCLUSIONS: Bone milling reduces the quantity of osteoblasts. Bone obtained by the ball reamer supplies a smaller number of cells than bone obtained by other methods. Unmilled spongy bone chips appear to offer the greatest amount of viable osteoblasts.

Adult↗

PubMed2004

Significant influence of scaler tip design on root substance loss resulting from ultrasonic scaling: a laserprofilometric in vitro study.

OBJECTIVES: Ultrasonic scalers have become increasingly popular for subgingival debridement. The aim of the present study was to investigate the influence of different working tip designs (narrow versus wide) on root substance loss caused by either magnetostrictive or piezoelectric ultrasonic devices. METHODS: In this in vitro study, a magnetostrictive ultrasonic system with either Slimline or TFI-10 inserts and a piezoelectric ultrasonic system with either Perioprobe or Type-A inserts were compared at different application forces. Loss of root dentin was determined by defect width, defect depth and defect volume resulting from standardized instrumentation using laser profilometry. RESULTS: There were consistent and statistically significant differences between all groups. The mean observed dentin alterations for the magnetostrictive ultrasonic device operating a Slimline insert at a lateral force of 0.3 N were 254.4 microm, 6.3 microm and 22.5 microm3 and for the TFI-10 tip 759.0 microm, 23.5 microm and 160.2 microm3 for the parameters defect width, depth and volume, respectively. For the piezoelectric ultrasonic system operating a Perioprobe insert, the corresponding mean values were 352.0 microm/12.1 microm/56.4 microm3 and for the universal Type-A insert they were 402.4 microm/14.0 microm/133.4 microm3. With application forces of 0.7 N, root substance removal increased up to twofold. CONCLUSION: The present investigation could demonstrate that the aggressiveness of magnetostrictive and piezoelectric ultrasonic devices to root substance was significantly influenced by the scaler tip designs, increasing for wider scaler tips as compared with narrow, probe-shaped inserts.

Dental Instruments↗

PubMed2003

Human growth hormone 1 (GH1) gene expression: complex haplotype-dependent influence of polymorphic variation in the proximal promoter and locus control region.

The proximal promoter region of the human pituitary expressed growth hormone (GH1) gene is highly polymorphic, containing at least 15 single nucleotide polymorphisms (SNPs). This variation is manifest in 40 different haplotypes, the high diversity being explicable in terms of gene conversion, recurrent mutation, and selection. Functional analysis showed that 12 haplotypes were associated with a significantly reduced level of reporter gene expression whereas 10 haplotypes were associated with a significantly increased level. The former tend to be more prevalent in the general population than the latter (p<0.01), possibly as a consequence of selection. Although individual SNPs contributed to promoter strength in a highly interactive and non-additive fashion, haplotype partitioning was successful in identifying six SNPs as major determinants of GH1 gene expression. The prediction and functional testing of hitherto unobserved super-maximal and sub-minimal promoter haplotypes was then used to test the efficacy of the haplotype partitioning approach. Electrophoretic mobility shift assays demonstrated that five SNP sites exhibit allele-specific protein binding. An association was noted between adult height and the mean in vitro expression value corresponding to an individual's GH1 promoter haplotype combination (p=0.028) although only 3.3% of the variance of adult height was found to be explicable by reference to this parameter. Three additional SNPs, identified within sites I and II of the upstream locus control region (LCR), were ascribed to three distinct LCR haplotypes. A series of LCR-GH1 proximal promoter constructs were used to demonstrate that 1) the LCR enhanced proximal promoter activity by up to 2.8-fold depending upon proximal promoter haplotype, and that 2) the activity of a given proximal promoter haplotype was also differentially enhanced by different LCR haplotypes. The genetic basis of inter-individual differences in GH1 gene expression thus appears to be extremely complex.

Adult↗

PubMed2003

Interleukin-1 gene polymorphisms and experimental gingivitis.

BACKGROUND: Recently, an association between the severity of periodontitis and specific variations in the interleukin-1 (IL1) alpha and beta genes has been demonstrated. AIM: : The purpose of this study was to evaluate the relationship of the IL1 genotype to the development of experimental gingivitis. MATERIALS AND METHODS: Twenty young adult subjects presenting with healthy gingival conditions participated after giving their informed consent. The group included 10 risk genotype positive (P+) and 10 risk genotype negative (P-) individuals. The IL1 genotypes were determined on DNA samples from peripheral blood using PCR-RFLP analyses for the IL1alpha and IL1beta polymorphisms. Experimental gingivitis was allowed to develop in two posterior sextants per subject. Bleeding on probing (BOP%) and gingival crevicular fluid volume (GCF) were assessed at baseline and days 2, 7, 9, 14, 16 and 21. The day 21 results for BOP and GCF as well as the rate of increase of these parameters - mean area under the curve (AUC) and mean increase per day (slope) - were evaluated using risk analyses for IL1 genotype, smoking status and gender. RESULTS: Experimental gingivitis developed with a gradual increase in BOP scores and GCF values (expressed as Periotron units=PU) from baseline to day 21 (BOP, P+: 0.5 to 26.0%; P-: 1.0 to 28.1%; GCF, P+: 36.8 to 138.5 PU, P-: 43.1 to 143.4 PU). No significant risk was associated with P+ and P- for day 21 results, AUC or slope. CONCLUSION: The results of this study failed to provide evidence that the IL1 risk genotype was associated with higher GCF volume and percentage BOP during the development of experimental gingivitis.

Adult↗

PubMed2003

Elevated levels of collagen cross-link residues in gingival tissues and crevicular fluid of teeth with periodontal disease.

Lysylpyridinoline (LP) and hydroxylysylpyridinoline (HP) are collagen cross-link residues. Lysylpyridinoline is present in most tissues, whereas LP is present mainly in mineralized tissue. Both are elevated in tissue with increased collagen resorption. The purpose of this investigation was to assess if the concentrations of LP and HP are elevated in gingiva and gingival crevicular fluid (GCF) of teeth with advanced periodontitis (AP). We investigated human gingival biopsies of healthy teeth (n = 19) and teeth with AP (n = 43) in 49 individuals. Samples of GCF from 54 teeth with AP were collected in seven patients and compared with samples from 11 patients with experimentally induced gingivitis. Levels of LP and HP were measured by HPLC and fluorescence detection. Gingival concentrations of HP but not LP around teeth with advanced periodontitis were significantly elevated compared with teeth with healthy periodontium. While significant amounts of HP and LP were measurable in the GCF of teeth with AP, no HP and LP was identified 3 months following non-surgical periodontal therapy of the teeth or in fluid from teeth subjected to experimentally induced gingivitis. Elevated concentrations of HP and LP in GCF may serve as indicators of ongoing destruction of periodontal tissues and alveolar bone in advanced periodontitis.

Adult↗