Biomedical subjects

M Lutz

Publications and source records attributed to M Lutz.

At least 19 recordsLinked to original sources

PubMed2006

Reconstruction of the digital flexor pulley system: a retrospective comparison of two methods of treatment.

The rare injury of closed rupture of the A2 and A3 flexor pulleys was treated using two non-encircling techniques of pulley reconstruction. Thirteen patients were treated with an extensor retinaculum graft (Group A). At a mean follow-up time of 48 months, the average PIP flexion was 97%, the power grip strength 96%, the pinch grip strength 100% and the thickening 94% of the uninjured side. Ten patients were treated with a free palmaris longus tendon grafts (Group B). At a mean follow-up time of 57 months, the average PIP flexion was 94%, the power grip strength 98%, the pinch grip strength 100% and the thickening 95% of the uninjured side. In both groups, finger extension was unrestricted. The Buck Gramcko score included 10 excellent, two good and one fair result in Group A and seven excellent, two good and one fair result in Group B. Both techniques proved beneficial. All climbers returned to their previous standard and all non-climbers regained full finger dexterity in their previous job.

Adult↗

PubMed2006

Fixation of nondisplaced scaphoid fractures: making treatment cost effective. Prospective controlled trial.

INTRODUCTION: Nondisplaced scaphoid waist fractures treated with prolonged plaster immobilisation often lead in transient joint stiffness and to a delay in return to sport and work activity. The long time off work increases the work off compensation costs. Internal fixation of scaphoid fractures has resulted in a shorter time to union and to return to work and sports. This prospective study compares cast immobilisation with screw fixation and the direct cost with indirect cost of conservative and minimally invasive treatment of undisplaced scaphoid fractures. MATERIALS AND METHODS: Forty-seven patients with an acute nondisplaced waist fracture of the scaphoid were allocated into either cast immobilisation or internal screw fixation for this study. Cost data concerning the groups of nonoperated and operated patients were analysed. Range of wrist motion, grip strength, DASH-score, time to fracture union, return to work time and the needed physiotherapy at the final follow-up at 6 months were evaluated. RESULTS: Twenty-one patients were included in the group of screw fixation and 23 patients were included in the group of cast immobilisation. At final follow-up there was no significant difference in the range of motion of the wrist or in grip strength. The operatively treated group had a better mean DASH-score than the conservative group. Fracture union was seen in the screw fixation group at a mean of 43 days and in the cast immobilisation group at a mean of 74 days (P < 0.5). The average time of return to work was 8 days for patients who had an internal screw fixation, while those treated with a cast returned to work at a mean of 55 days (P < 0.5). In total the internal fixation of undisplaced scaphoid fractures is less expensive than conservative treatment. CONCLUSION: Internal screw fixation of nondisplaced scaphoid fractures had a shorter time to bony union and the patients returned earlier to work compared with cast immobilisation. Although it is assumed that operative treatment is more expensive, in this study the cost was not found to be higher.

Adult↗

PubMed2006

Correlation of health-related quality of life after surgery for mesial temporal lobe epilepsy with two seizure outcome scales.

PURPOSE: The objective of this study was to correlate health-related quality of life (HRQOL) after surgery for mesial temporal lobe epilepsy, as revealed by a postoperative screening tool, to different modalities of seizure outcome classification (Engel, International League Against Epilepsy (ILAE)). METHOD: One hundred twenty-eight of one hundred forty consecutive patients returned a HRQOL questionnaire at a mean of 36 months after selective amygdalohippocampectomy. Patients answered in two ways: with an absolute estimation (values 1-4) and with a self-rated relative change (-1, 0, +1) after surgery. RESULTS: Eighty patients were seizure- and aura-free (63.3% ILAE 1), 16 continued to have auras (12.5% ILAE 2), and 13 experienced 1-3 seizure days per year after surgery (10.2% ILAE 3). Ninety-two patients were classified seizure-free (71.9% Engel I), and 17 had two or fewer seizures per year (13.3% Engel II). Of 110 patients in ILAE 1-3, 100 (91%) stated good or even very good postoperative HRQOL, and 99 (90.0%) reported improvements in HRQOL. Only 9 of the remaining 18 (50%) reported good or very good HRQOL after surgery (P=0.01). Corresponding results were obtained with Engel classes I and II, suggesting a trend toward ILAE 1-3 and Engel I and II as overall satisfactory outcomes. A more detailed HRQOL assessment yielded lowest scores in the cognitive domain, and a significant correlation of self-rated changes in cognitive functioning with seizure control (P=0.01). Changes in physical capabilities and mood were significantly better with satisfactory seizure outcome (P=0.006 and P<0.001, respectively), whereas the social aspects were not significantly dependent on seizure outcome (P=0.06). CONCLUSION: Correlation of HRQOL and seizure control suggested that ILAE 1-3 and Engel I and II most likely represent overall satisfactory outcome. Subdomain analyses revealed cognitive abilities as the most critical feature associated with seizure control, whereas social aspects remained mainly stable.

Adolescent↗

PubMed2005

Palmar locking plate for treatment of unstable dorsal dislocated distal radius fractures.

INTRODUCTION: This study investigates the clinical and radiological results of open reduction and internal fixation of unstable distal radial fractures using a palmar placed interlocking plate system with no substitutes for treatment of the dorsal metaphyseal fracture void. MATERIALS AND METHODS: Nineteen patients with a mean age of 61 years (range 49-78 years) and a dorsally displaced distal radial fracture were treated using a palmar placed 2.4 mm interlocking plate system. All 17 women and 2 men were followed up according to the study protocol. Standardised radiographs in anteroposterior and lateral projection were performed before reduction and at 2, 6, 12 and 24 weeks after surgery. Radiological measurements included palmar tilt, radial inclination and radial shortening as defined by ulnar variance and intra-articular steps. Clinical assessment included active range of motion (ARM) of the wrist, pain according to a visual analogue scale (VAS), grip power, working ability, Disability of Arm, Shoulder and Hand-Score (DASH Score) and Mayo Wrist Score. RESULTS: At final follow-up after a minimum of 11 months, the palmar tilt was +1 degrees , radial inclination 19.8 degrees and ulnar variance 1.0 mm. Mean loss of palmar tilt measured 1.9 degrees , radial inclination 1.3 degrees and ulnar variance 0.4 mm. Mean wrist extension measured 58 degrees , wrist flexion 41 degrees , pronation 83 degrees and supination 84 degrees . The Mayo Wrist Score showed 21% excellent, 58% good, 16% fair and 5% poor results. CONCLUSION: The treatment of unstable, dorsally dislocated, distal radius fractures AO types A3, C1 and C2, with a palmar placed 2.4 mm interlocking plate system and without additional treatment of the metaphyseal defects showed good radiological and functional results with minimal loss of reduction.

Aged↗

PubMed2005

Sagittal wrist motion of carpal bones following intraarticular fractures of the distal radius.

Forty patients (mean age, 37 years) with intraarticular C2 and C3 Colles fractures were treated by open reduction, internal fixation and bone grafting. At a mean follow-up of 8 years radiocarpal and midcarpal motion was evaluated, the depth of the articular surface of the distal radius in the sagittal plane was measured and the presence of arthritis was noted. The fractures healed with a mean palmar tilt of 6 degrees , a mean ulnar tilt of 18 degrees and ulna variance within 1 mm of the contralateral side. The depth of the articular surface of the distal radius was 1.3 mm greater than the uninvolved side. Measurement of carpal bone angles relative to the radius in maximum flexion and extension revealed lunate extension of 23 degrees , lunate flexion of 15 degrees , capitate extension of 62 degrees , capitate flexion of 40 degrees . There was a significant correlation between articular surface depth and radiocarpal motion.

Adolescent↗

PubMed2005

Delayed single Kirschner wire compression technique for mallet fracture.

Twenty-four mallet fractures which involved at least one third% of the articular surface of the distal interphalangeal joint were treated by open reduction and internal fixation using a single double-ended Kirschner wire at a mean of 9 days after injury (range 4-15). At a mean follow-up of 43 (range 12-18) months the active range of motion, pain and the Warren and Norris criteria were evaluated. The mean active range of motion was from - 2 degrees extension (range 0-10 degrees ) to 72 degrees flexion (range 50-90 degrees ). Nineteen patients were pain free and five suffered from mild pain during strenuous work. The Warren and Norris results were successful in 22 and improved in two cases. Radiographs showed, that all the fractures united in a near-anatomic position but with joint narrowing in six digits.

Adolescent↗

PubMed2005

[Therapy for static scapholunate instability -- reconstruction of the dorsal part of the scapholunate ligament with a periosteal flap of the iliac crest].

Recurrent instability is frequent following capsulodesis, tenodesis, or ligament reconstruction in static scapholunate instability. Therefore a periosteal flap of the iliac crest was designed to reconstruct the dorsal part of the SL ligament, which is known to be the biomechanically strongest portion and also the axis of rotation between the scaphoid and lunate. Biomechanical testing of ten fresh frozen dorsal SL ligaments and ten periosteal flaps of the iliac crest showed similar properties concerning failure force, failure displacement, failure stress, energy to failure and stiffness. Results of eight specimens in each group were available following successful testing. Failure force of the dorsal SL ligament was 171.8 N (SD 44.2), energy to failure amounted 269.1 N-mm (SD 98.9), failure stress was 10.3 N/mm (2) (SD 1.3), failure displacement 2.9 mm (SD 0.4), and stiffness 77.2 N/mm (SD 21.4). Testing of the periosteal flap gave the following values: failure force 144.3 N (SD 38.7), energy to failure 217.9 N-mm (SD 85.0), failure stress 9.9 N/mm (2) (SD 1.7), failure displacement 3.0 mm (SD 0.4) and stiffness 60.5 N/mm (SD 14.7). In addition to these test values, clinical and radiological data of eleven patients were available following reconstruction of the dorsal SL ligament with a periosteal flap of the iliac crest. The interval between trauma and surgery was 15 months, mean follow-up was 29 months. One patient was free of pain, whereas ten mentioned pain during or following strenuous work. Two patients were completely satisfied, nine complained about some restriction during special activities. Active range of motion amounted to 56 degrees extension, 46 degrees flexion, 17 degrees radial abduction, 30 degrees ulnar abduction. Grip strength was 38.5 kg, which was 79 % of the contralateral side. Radiological evaluation demonstrated a correction of the static instability in nine cases. In two patients recurrence of static instability was obvious. The prerequisite for success of the procedure is the easy reduction of the carpals. In cases of a fixed rotatory subluxation of the scaphoid, the technique cannot maintain the reduction.

Adult↗

PubMed2005

Antifungal effect of 5-aminolevulinic acid PDT in Trichophyton rubrum.

In the present investigation, we have shown for the first time that the onychomycosis-inducing dermatophyte Trichophyton rubrum was able to metabolize 5-aminolevulinic acid (ALA) to protoporphyrin IX (PpIX) in liquid culture medium. We have established and optimized the culture conditions and could show the typical PpIX-induced red fluorescence which was evaluated qualitatively by Wood's light examination and fluorescent microscopic analysis. The optimum concentration of ALA was in the range of 1-10 mmol l(-1). If used in higher concentrations, ALA leads to a significantly reduced growth rate and absence of PpIX formation due to highly acidic conditions. The first observation of red fluorescence was detected between 10 and 14 days poststimulation with ALA, increasing thereafter. Fluorescent microscopic examinations demonstrated that formation of PpIX was restricted to selected parts of the fungal mycelium. Repeated application of ALA in order to achieve the highest formation of PpIX in T. rubrum failed, probably due to the sustained low pH values. ALA treatment and irradiation of T. rubrum clearly demonstrated the growth-inhibiting effect of ALA PDT, either leading to reduced numbers of colonies or reduced diameters of single fungal colonies. Summarizing our results, ALA PDT might be a promising approach in the reduction of T. rubrum colonization in onychomycosis.

Aminolevulinic Acid↗

PubMed2004

Dorsolateral dislocation of the proximal interphalangeal joint: closed reduction and early active motion or static splinting; a retrospective study.

INTRODUCTION: In a follow-up examination 50 patients who had sustained dorsal dislocations of the proximal interphalangeal (PIP) joint, the results of two conservative therapy regimens, either immobilisation or early motion, were investigated. The patients were assigned randomly. The inclusion criteria were: adult patients over the age of 18 with isolated, acute, closed dorsolateral dislocation of the PIP joint. MATERIALS AND METHODS: In group A, 25 patients were treated by closed reduction and immobilisation with a short-arm cast including both interphalangeal joints for 4 weeks. In group B, 25 patients were treated by dorsal block splinting of the PIP joint following reduction. The finger was released in extension with daily active exercise of the PIP joint. RESULTS: In group A, 9 patients showed a normal range of motion, whereas a limitation of extension of 10 deg and more was seen in 16 patients. All PIP joints were clinically stable, and 19 patients were satisfied. Two patients complained of a limitation of extension, 3 of limitation of extension and pain, and 1 of pain and swelling. In group B, only 2 of 25 patients showed a limitation of extension of 10 deg and more, whereas 23 patients showed a normal range of motion. Instability of one collateral ligament was seen in 2 cases. Palmar instability did not occur, and 18 patients were satisfied. One patient complained of instability, pain and lack of extension during hard work, 1 of pain in combination with instability, 2 of pain and 3 of swelling of the joint. CONCLUSION: Early active motion after dorsolateral dislocation of the PIP joint produces significantly superior results regarding the active range of motion and pinch power than static splinting.

Casts, Surgical↗

PubMed2004

Dorsal scapholunate ligament reconstruction using a periosteal flap of the iliac crest.

INTRODUCTION: To report a new technique for scapholunate ligament reconstruction, using a periosteal flap of the iliac crest. MATERIALS AND METHODS: In 12 patients with static SL instability, a periosteal flap was harvested from the anterior portion of the iliac crest. Following repositioning of the carpals, the flap was fixed to the scaphoid and lunate between an incompletely osteotomised scale at the dorsal horn of the scaphoid and lunate. Pin fixation of the scapholunate (SL) and CL interval secured postoperative reduction for 8 weeks. A forearm plaster cast was worn for 12 weeks. RESULTS: Eleven patients, all male, were available for follow-up at an average of 29 months. The interval between trauma and surgery averaged 15 months. The preoperative SL angle measured 77 deg, CL angle was -10 deg, and SL gap amounted to 5.2 mm. At follow-up, SL angle was 59 deg, CL angle measured -2 deg, and SL gap was 2.1 mm. SL gap, SL angle, and CL angle improved significantly from preoperative to follow-up values. According to the clinical grading system of Green and O'Brian, 6 patients scored in the excellent and good category and 5 in the fair category. Using the radiologic grading system of Gickel and Millender, 9 patients scored as excellent and good, whereas the 2 poor results were due to failure of the technique. CONCLUSION: The technique enables reduction of the SL angle and SL gap in patients with static reducible scapholunate instability. The initial results are quite encouraging.

Bone Transplantation↗

PubMed2004

Anatomical basis for functional treatment of dorsolateral dislocation of the proximal interphalangeal joint.

Dorsolateral dislocation of the proximal interphalangeal (PIP) joint is a common injury to the hand. Closed reduction of the dislocation anatomically realigns the avulsed ligaments; thus patients may be managed non-operatively. Standard treatment involves placement of a dorsal splint to prevent hyperextension and lateral stresses. This allows early active motion of the PIP joint while preventing a flexion contracture. In this fresh cadaver study, the PIP joint in 24 fingers was dorsolaterally dislocated. Four digits had to be excluded from the investigation due to a fracture dislocation with a bony fragment of >40% of the articular surface of the middle phalanx. After closed reduction, seven digits were further studied using the cryosection technique described by Kathrein et al. (1996, Clin. Anat. 9:227-231) to demonstrate the position of the avulsed palmar plate. In another 13 joints, the torn ligaments were examined by gross dissection. In 10 degrees of finger flexion, the avulsed palmar plate lay at its previous attachment to the base of the middle phalanx. The collateral ligament, ruptured at its attachment to the side of the head of the proximal phalanx, returned to its original position and was not interposed in the joint. The split between the collateral ligament and the accessory collateral ligament was also closed. Our data suggest that the ligamentous structures of the PIP joint, namely the palmar plate and collateral ligaments, typically return to their anatomic positions upon simple closed reduction of dorsolateral dislocations in fresh cadavers.

Aged↗

PubMed2004

Bilateral hand transplantation: bone healing under immunosuppression with tacrolimus, mycophenolate mofetil, and prednisolone.

PURPOSE: Little is known about bone healing after composite tissue transplantation that requires pharmacologic immunosuppression. Bone integration and callus development were assessed in bilateral hand transplantation. METHODS: In this study the course of callus development and callus maturation were assessed by color Doppler sonography and radiography in a double hand transplant and compared with forearm replantation. RESULTS: After hand transplantation, ingrowth of small vessels at the bone junction was observed at week 3, calcified callus became visible at month 4, and bone union was completed at month 11. A similar time course of bone integration was observed after replantation. Plating offered sufficient stability. A recipient periostal flap is thought to have improved blood supply and favored development and induction of callus. CONCLUSIONS: Bone healing after hand transplantation under immunosuppression with tacrolimus, mycophenolate mofetil, and prednisolone is identical to that after forearm replantation.

Amputation, Traumatic↗

PubMed2004

Method for large scale isolation, culture and cryopreservation of human monocytes suitable for chemotaxis, cellular adhesion assays, macrophage and dendritic cell differentiation.

This paper presents an improved method of isolating, culturing and cryopreserving human monocytes in large quantity with high purity using standard laboratory centrifuges. Monocytes were isolated from 300 to 360 ml of heparinized human blood using a Double Density technique employing Ficoll Isopaque and 46% iso-osmotic Percoll. Yields of monocytes ranged from 75 to 205 million (from 300 to 360 ml of blood) with an average purity of 90.6%. The ability of fresh or frozen monocytes to adhere to endothelial cells in the presence of oxidized L-alpha-1-palmitoyl-2-arachidonosyl-sn-glycero-3-phosphocholine (oxPAPC) or lipopolysaccharide (LPS) did not differ and no significant difference in response to the chemotactic stimulant N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) was observed. We define a useful method for the culture and differentiation of fresh or frozen monocytes isolated by this method, into macrophages as judged by morphology, expression of the macrophage marker SRA-1 and induction of inflammatory genes TNF-alpha, IL-6 and COX-2. Also, fresh or frozen Double Density isolated cells can be successfully differentiated into dendritic cells in the presence of GM-CSF and IL-4 as judged by the expression of the hallmark surface proteins CD1a and DC-sign and the absence of CD14. This method also yields a pure population of lymphocytes.

Cell Adhesion↗

PubMed2003

Randomized phase III study of high-dose fluorouracil given as a weekly 24-hour infusion with or without leucovorin versus bolus fluorouracil plus leucovorin in advanced colorectal cancer: European organization of Research and Treatment of Cancer Gastrointestinal Group Study 40952.

PURPOSE: This trial was conducted to determine whether high-dose fluorouracil (FU) given as a weekly 24-hour infusion is more active than bolus FU + leucovorin (LV), and whether high-dose infusional FU can be modulated by LV. PATIENTS AND METHODS: A total of 497 patients with previously untreated metastatic colorectal cancer were randomly assigned to receive bolus FU 425 mg/m2 intravenously + LV 20 mg/m2 on days 1 to 5 and repeated on day 28 (FU + LV), or FU 2600 mg/m2 as a 24-hour infusion alone (FU24h) or in combination with 500 mg/m2 LV (FU24h + LV)-all given weekly x6 followed by a 2-week rest period. Survival was the major study end point. RESULTS: With a median follow-up of more than 3 years, survival did not differ among the treatment groups (median FU + LV, 11.1 months [95% CI, 10.2 to 15.0 months]; FU24h, 13.0 months [95% CI, 10.4 to 15.4 months]; FU24h + LV, 13.7 months [95% CI, 12.0 to 16.4 months]; P =.724). Progression-free survival (PFS) was significantly longer for FU24h + LV (median FU + LV, 4.0 months [95% CI, 3.4 to 4.9]; FU24h, 4.1 months [95% CI, 3.4 to 5.0]; FU24h + LV 5.6 months [95% CI, 4.4 to 6.7]; P =.029). The response rates in the subgroup of patients with measurable disease were 12%, 10%, and 17% for FU + LV, FU24h, and FU24h + LV, respectively (not significant). Occurrence of grade 3 and 4 diarrhea was higher in the FU24h + LV arm (22%) compared with the FU24h (6%) or FU + LV (9%) arms; however, stomatitis (11% in FU + LV v 3% in FU24h v 5% in FU24h + LV arms) and hematologic toxicity were higher in the bolus FU + LV arm. Global quality of life did not differ within the three arms. CONCLUSION: Neither FU24h + LV nor FU24h prolong survival, relative to bolus FU + LV. Leucovorin increases PFS if added to FU24h, but increases toxicity.

Adult↗

PubMed2003

Scapholunate ligament reconstruction using a periosteal flap of the iliac crest: a biomechanical study.

INTRODUCTION: Advances continue to improve direct reconstruction of the dorsal scapholunate (SL) ligament, which is the strongest part of the entire SL ligament and is known as the turning point between the scaphoid and lunate. This study was designed to compare the biomechanical properties of the dorsal SL ligament with those of a periosteal flap of the iliac crest, which is a new graft candidate for dorsal SL reconstruction. MATERIALS AND METHODS: A bone-ligament-bone complex was harvested for biomechanical testing from the iliac crest and the dorsal SL complex. Ten specimens could be prepared in each group. After potting the bone blocks in methylmethacrylate for stable fixation, the specimens were tested, using a servohydraulic testing system, at a rate of 10 mm/min. RESULTS: Failure displacement, failure force, failure stress, energy to failure, and stiffness were assessed for both groups. Eight specimens in each group were tested successfully. In the ligament group, six specimens failed at the ligament level, whereas two failed at the insertion of the scaphoid. In the periosteum group, all eight specimens failed at the ligament level. The failure force of the dorsal SL ligament averaged 171.8 N, failure stress was 10.3 N/mm2, and failure displacement amounted to 2.9 mm. Energy to failure was 269.1 N-mm, and stiffness averaged 77.2 N/mm. Failure force of the periosteal flap amounted to 144.3 N, failure stress was 9.9 N/mm2, failure displacement was 3.0 mm, and energy to failure was 217.9 N-mm. Stiffness of the periosteal flap measured 60.5 N/mm. Comparison of the dorsal SL ligament and the periosteal flap of the iliac crest revealed no significant biomechanical differences. CONCLUSION: Therefore, the biomechanical properties of the periosteal flap recommend its use for reconstruction of the dorsal SL ligament.

Biomechanical Phenomena↗

PubMed2003

[Long-term results after a modified Sauvé-Kapandji procedure. Report on 105 post-traumatic cases].

A modified Sauvé-Kapandji procedure was performed on 105 patients for a painfully limited range of motion and arthritis of the distal radioulnar joint following distal fracture of the radius ( n=81), the radius and ulna in the distal one-third ( n=18) and of the forearm shaft ( n=6). After an average of 8 years all patients were followed up clinically (motion, strength, pain) and radiographically (union of the arthrodesis, carpal translation, radioulnar distance). Rotation of the forearm had been improved by 53%. The amount of strength lay by 70% in comparison to the contralateral side. In 97% of the patients pain could be reduced. In all cases the arthrodesis had fused completely. An ulnar drift of the carpus was observed in 5% of the patients, and 74% of the patients showed radiological signs of approximation of the proximal ulnar stump to the radius. This reduction of the radioulnar distance amounted to less than 3 mm in 65% of the patients and lay between 3 and 5 mm in 29% of the patients. In none of the cases was direct contact between the ulna and the radius encountered.

Adult↗

PubMed2003

Closed reduction transarticular Kirschner wire fixation versus open reduction internal fixation in the treatment of Bennett's fracture dislocation.

Thirty two patients with fracture dislocations of the base of the thumb metacarpal with a single large fracture fragment (Bennett's fracture) were either treated by open reduction and internal fixation or closed reduction and percutaneous transarticular Kirschner wiring. All were assessed at a mean follow up of 7 (range 3-18) years. Patients with an articular step off more than 1mm were excluded. The type of treatment did not influence the clinical outcome or the prevalence of radiological post-traumatic arthritis. The percutaneous group had a significantly higher incidence of adduction deformity of the first metacarpal. This was attributed to Kirschner wire placement near the fracture line or in the compression zone of the fracture, resulting in loss of reduction. This however did not result in an inferior outcome.

Adult↗

PubMed2002

The thyroid hormone receptor and the insulator protein CTCF: two different factors with overlapping functions.

Thyroid hormones and thyroid hormone receptors (TRs) confer a fundamental regulation of critical genes involved in metabolism, differentiation, and development. A similar role is attributed to the highly conserved zinc-finger factor CTCF. Furthermore, a potential role in tumour suppression has been attributed to CTCF. In addition to promoter regulation, CTCF has also been shown to be involved in chromatin insulation or enhancer blocking. In several cases, binding sites for TR and for CTCF have been found next to each other. Functionally, these sites mediate synergistic repression or induction dependent on the type of binding site and on the presence or absence of thyroid hormone. Here we discuss functional similarities between TR and CTCF and their roles within these composite elements.

Animals↗