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Hahn P, Gustav M, Hellwig E. An in vitro assessment of the strength of porcelain veneers dependent on tooth preparation. J Oral Rehabil 2008. [DOI: 10.1111/j.1365-2842.2000.00640.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Maher MM, Rizzo S, Kalra M, Mc Sweeney SE, Arellano R, Hahn P, Gervais D, Mueller P. Radiological management of patients with urinary obstruction following urinary diversion procedures: Technical factors, complications, long-term management and outcome. Experience with 378 procedures. J Med Imaging Radiat Oncol 2008; 52:237-43. [DOI: 10.1111/j.1440-1673.2008.01953.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hahn P, Off J. [Profit or loss--can handsurgery be profitable?]. HANDCHIR MIKROCHIR P 2008; 40:211-213. [PMID: 18677794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
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Sagheri D, Hahn P, Hellwig E. Assessing the oral health of school-age children and the current school-based dental screening programme in Freiburg (Germany). Int J Dent Hyg 2007; 5:236-41. [PMID: 17927637 DOI: 10.1111/j.1601-5037.2007.00250.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
UNLABELLED Germany has a three-tiered system of education at secondary school level, divided into the school types 'Hauptschule', Realschule' and 'Gymnasium'. All students receive, when aged 6-12 years, a uniform annual dental examination and oral health education programme. OBJECTIVES The aim of this cross-sectional study was to report on the dental caries levels of school-age children stratified into these three different school types at secondary school level to enable oral healthcare personnel to administer a focused, school-based dental screening and education programme according to patients' needs rather than a uniform dental examination. METHODS A representative, random sample of 12-year-old school children in Freiburg (Germany) was examined and dental caries was recorded using WHO criteria. RESULTS A total of 322 12-year-old children participated. The mean DMFT was 0.69. An examination of the distribution of the DMFT score revealed that its distribution is positively skewed. For this reason, this study provides summary analyses based on medians and a non-parametric rank sum test. The non-parametric Kruskal-Wallis H-test showed a highly significant difference between median scores across the different school types (P-value = 0.004). The significance was a result of the 'Gymnasium' distribution of DMFT scores which differed markedly from the other two school types. CONCLUSIONS The finding of the present study suggests that it may be useful to stratify the school dental screening and education programme according to school type and to prioritize children who attend 'Realschule' and 'Hauptschule'. This shift should systematically target children with the greatest need for dental care.
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Hahn P, Kall S, Reiter A, Unglaub F. [Motor considerations in the forearm and hand]. ACTA ACUST UNITED AC 2006; 144:R39-56; quiz R57-8. [PMID: 16821164 DOI: 10.1055/s-2006-924010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Schirrmeister JF, Huber K, Hellwig E, Hahn P. Two-year evaluation of a new nano-ceramic restorative material. Clin Oral Investig 2006; 10:181-6. [PMID: 16721551 DOI: 10.1007/s00784-006-0048-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2005] [Accepted: 04/05/2006] [Indexed: 11/29/2022]
Abstract
The purpose of this prospective study was to evaluate the clinical performance of a new restorative material (Ceram.X) in combination with a new primer-adhesive (K-0127). One operator placed two Class I or II restorations in molars of 43 patients. One molar was restored with Ceram.X/K-0127, the other one with Tetric Ceram/Syntac Classic. At baseline, after 1 and 2 years, the restorations were evaluated by one evaluator using modified Ryge's criteria. After 2 years, 31 patients were examined. One Ceram.X-restoration had to be removed for root canal treatment due to pulpitis. Thus, failure rate of Ceram.X was 3.2% and of Tetric Ceram, 0%. In both groups, no sensitivity, no recurrent caries, and no changes in surface texture were recorded after 2 years. One restoration in each group showed slight changes in color stability (score B). Marginal discoloration (score B) was found concerning three Ceram.X-restorations (10.0%) and two Tetric Ceram-restoration (6.5%). Marginal integrity was score B for four Ceram.X-restorations (13.3%) and for four Tetric Ceram-restorations (12.9%). No statistically significant differences were found (p>0.05). After 2 years of clinical service, 96.8% of Ceram.X/K-0127 and 100% of Tetric Ceram/Syntac Classic restorations were in place and performed clinically well.
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Unglaub F, Bultmann C, Reiter A, Hahn P. Two-staged reconstruction of the flexor pollicis longus tendon. ACTA ACUST UNITED AC 2006; 31:432-5. [PMID: 16618523 DOI: 10.1016/j.jhsb.2006.02.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Revised: 02/16/2006] [Accepted: 02/23/2006] [Indexed: 10/24/2022]
Abstract
The purpose of this study was to evaluate the results of two-stage reconstruction of the flexor pollicis longus (FPL) tendon. Sixteen patients who underwent reconstructive surgery of the FPL tendon were assessed retrospectively. Eight weeks after implantation of a silastic spacer, a tendon graft was used for reconstruction (thirteen palmaris longus tendons, two plantaris tendons, one half of the flexor carpi radialis tendon). Power grip, active range of motion, passive range of motion, the Buck-Gramcko assessment, the ASSH assessment and the DASH score were used to evaluate the results. Adequate function in 75% of the cases and a median of 11 on the DASH score was achieved. The results showed that two-stage reconstruction of the FPL tendon can produce satisfactory results, even if primary repair is the ideal.
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Unglaub F, Lanz U, Hahn P. Outcome Analysis, Including Patient and Parental Satisfaction, Regarding Nonvascularized Free Toe Phalanx Transfer in Congenital Hand Deformities. Ann Plast Surg 2006; 56:87-92. [PMID: 16374103 DOI: 10.1097/01.sap.0000188109.65963.42] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The therapy for congenital hand malformations, especially in symbrachydactyly and constriction ring syndromes, is challenging. Between 1975 and 1995, 20 children with congenital hand deformities underwent reconstruction by 56 nonvascularized free toe phalanx transfers. The average age at initial surgery was 4.8 (range, 0.5 to 22) years. Retrospectively, the children were examined after an average of 3.5 (range, 1.5 to 17.6) years for function of the hand, transplanted phalanx growth, assessment for the epiphyseal plate, and assessment for psychologic performance with their parents. Donor-site morbidity was determined according to measured growth deficit, observing the child's gait, and toe function. In the younger patients (up to 1.5 years), the grafts were well tolerated and showed good growth and only few resorptions. In the age group from 1.5 to 4 years, the grafts showed no growth. In the age group older than 4 years, the grafts were mostly resorbed. The clinical reexamination revealed in most cases only passive motion in the joints, but the function of the hand was improved, with only few problems of the donor site. Most patients and their parents reported a positive effect of the phalanx transfer.
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Unglaub F, Goldbach C, Hahn P. Reoperation bei Karpaltunnelsyndrom. DER NERVENARZT 2005; 76:1506, 1508-10, 1512-4. [PMID: 16133428 DOI: 10.1007/s00115-005-1984-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND The goal of this study was the reexamination, description, and analysis of postoperative results after carpal tunnel release reoperation. PATIENTS AND METHODS Thirty-eight patients were examined retrospectively 2 years after reoperation of carpal tunnel release. All of them had had complaints after the first operation. On the basis of DASH and Amadio questionnaires after the reoperation, the patients were divided into two groups: good results and inadequate results. RESULTS The reasons for reoperation included incomplete division of the retinaculum, early fibrosis, reoccurrence, late fibrosis, intraoperative complication, and one unclear situation. A quarter of the patients were free of complaints; three quarters had symptoms in which sensation improved but strength and function did not. CONCLUSION The clinical findings showed satisfying results for the patients. Reoperation is indicated after early postoperative deterioriation or if there is no improvement.
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Reiter A, Hasan M, Unglaub F, Dreyhaupt J, Hahn P. Ergebnisse der konservativen Therapie beim frischen und alten ligamentären Mallet-Finger. Unfallchirurg 2005; 108:1044, 1046-8. [PMID: 16034635 DOI: 10.1007/s00113-005-0974-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND In the treatment of the acute ligamentous mallet finger, conservative therapy with a Stack or Winterstein splint is an established approach, though there are many different conservative therapy regimes. There are even more therapy options for the chronic mallet finger (more than 4 weeks old) including different operation techniques. MATERIAL AND METHODS In a retrospective study, 44 patients with an acute and 33 patients with a chronic ligamentous mallet finger treated with a Stack or Winterstein splint were investigated. RESULTS The results in both groups are satisfactory (SD <10 degrees : 70.5% in the acute, 87.9% in the chronic lesions). The subjective satisfaction (scale 1-6) was high in both groups. It was even significantly higher in the group with the chronic lesions (acute: 2.55+/-1.63, chronic: 1.82+/-1.38). In both groups there was no correlation between an initially high extension deficit and a bad therapy outcome. CONCLUSIONS Also in chronic ligamentous mallet finger, conservative therapy should be attempted before an operation, irrespective of the initial extension deficit, especially because the stress and the therapy risk for the patient with this therapy is small.
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Hahn P. Full ceramic restorations in posterior teeth. Br Dent J 2005. [DOI: 10.1038/sj.bdj.4813037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Unglaub F, Kall S, Reiter A, Hahn P. Tendovaginosis stenosans - was nützt die Injektionstherapie? ACTA ACUST UNITED AC 2005; 143:475-8. [PMID: 16118765 DOI: 10.1055/s-2005-836567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
AIM Symptoms, frequency of complaints, patient's subjective assessment, and relapse rate were evaluated in patients provided with injection therapy for stenosing tenovaginitis (ST). METHODS Fifty-five patients (34 women, 21 men) suffering from ST underwent injection therapy of 0.25 ml triamcinolone and 0.25 ml mepivacain hydrochloride administered under the A1 pulley. Symptoms, frequency of complaints, subjective assessment, and evidence of recurrent disease were monitored for 5 years following injection therapy. Patients were divided into 3 groups: injection therapy with good outcome, injection therapy with poor outcome, and injection therapy but subsequently operated. RESULTS The middle finger (38 %) and the ring finger (31 %) were affected most commonly. ST afflicted more women than men. Twenty-seven patients (49 %) showed long-term relief of symptoms. Sixty-six percent of patients experienced short-term relief of symptoms. Therapy failure was more common in men, in younger patients, and in patients with diabetes. Better results were seen in women, in older patients, and in patients with rheumatism. Complications of injection therapy did not occur during this study. CONCLUSION Injection therapy is a justifiable alternative to surgery in patients with ST. In this study, half of the patients treated described long-term relief of symptoms, and assessed the effects of injection therapy positively. Especially satisfied patients included women, older patients, and patients with rheumatism.
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Unglaub F, Christopoulos G, Hahn P. [Palmar carpal-metacarpal dislocation with hamulus fracture]. ROFO-FORTSCHR RONTG 2005; 177:576-7. [PMID: 15838765 DOI: 10.1055/s-2005-858036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Rex T, Tsui I, Hahn P, Maguire A, Duan D, Bennett J, Dunaief J. Adenovirus-mediated delivery of catalase to retinal pigment epithelial cells protects neighboring photoreceptors from photo-oxidative stress. Hum Gene Ther 2005; 15:960-7. [PMID: 15585111 PMCID: PMC4118285 DOI: 10.1089/hum.2004.15.960] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Oxidative stress is involved in the pathogenesis of many diseases. Overexpression of antioxidant enzymes by gene therapy may protect tissues from oxidative damage. Because the reactive oxygen species hydrogen peroxide can diffuse across cell membranes, we hypothesized that overexpression of the antioxidant catalase within certain cells might protect neighboring cells. To test this hypothesis, we transduced retinal pigment epithelial (RPE) cells in vitro and in vivo with adenovirus carrying the catalase gene (Ad.CMV.catalase). After transduction of only a subset of RPE cells in vitro, all cells in the culture were protected from exogenous hydrogen peroxide. Similarly, in vivo, eyes injected with Ad. CMV. catalase had high catalase levels in the RPE, which protected the adjacent photoreceptors from light damage and reduced photoreceptor oxidative stress as measured by the markers 4-hydroxynonenal and nitrotyrosine. Both in vitro and in vivo, gene therapy with Ad. CMV. catalase protected neighboring cells from oxidative stress-induced terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) positivity. The data provide a paradigm for antioxidant gene therapy with catalase, designed to protect not only transduced cells, but also neighboring cells.
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Kächele V, Hahn P, Adler G, Seufferlein T. [Chemotherapy for colorectal carcinoma in the elderly]. ZEITSCHRIFT FUR GASTROENTEROLOGIE 2005; 42:1189-98. [PMID: 15508061 DOI: 10.1055/s-2004-812927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
With nearly 50 % of all colorectal cancers being diagnosed in patients at the age of 70 or above colorectal cancer is a disease of the elderly. In an adjuvant setting, fit elderly patients can receive the same benefit from cytotoxic therapy as younger patients with an only slightly increased toxicity. In a palliative setting, the treatment of elderly patients with respect to clinical endpoints such as response, time to progression or overall survival is as effective as in their younger counterparts. In clinical studies, older patients are generally underrepresented and among the elderly patients involved in clinical studies there is a bias towards particularly fit patients. Therefore it is not possible to extrapolate the results of many randomized trials to all elderly patients. A Comprehensive Geriatric Assessment (CGA) should be applied to detect the diversities in the geriatric population. Based on this assessment elderly patients classified as suitable for chemotherapy should be enrolled into clinical trials for colorectal cancer.
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Könnecke HG, Hahn P. Zur Chlorierung von Alkanen. I. Chromatographische Trennung der Chloralkane, die bei der Chlorierung von Hexakontan erhalten werden. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/prac.19620160106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Hahn P, Hellwig E. An in vitro investigation of penetration depth of dentine bonding agents into carious dentine. J Oral Rehabil 2004; 31:1053-60. [PMID: 15525382 DOI: 10.1111/j.1365-2842.2004.01332.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aim of the present in vitro study was to determine the penetration depth of dentine bonding agents into carious dentine as a possible strategy in caries treatment of deep lesions. Forty-eight extracted carious teeth were used for the experiments and divided in four groups. In a split-tooth design, one half of each tooth was treated without caries excavation, and the second half after caries excavation. In group 1 the teeth were treated with Prime & Bond 2.0 without phosphoric acid etching, and in group 2 with phosphoric acid etching. In group 3, the teeth were treated with All-Bond 2 without phosphoric acid etching, and in group 4 with phosphoric acid etching. Bonding agents were marked with an orange dye prior to application. The composition of the bonding agents had no significant influence on penetration depths. The mean thickness of the outer, necrotic caries zone in unexcavated specimens was 117 microm (+/-126). Bonding agents penetrated significantly deeper into unexcavated carious dentine (mean 124 +/- 76 microm) compared with excavated dentine (11 +/- 14 microm) and sound dentine (3 +/- 4 microm). Acid etching significantly reduced the thickness of the outer caries zone, and the penetration depth of the bonding agents into unexcavated carious specimens by approximately 50%, and increased it into sound dentine. The results indicate that dentine bonding agents could completely penetrate the unexcavated outer carious dentine in 90% of specimens. Further studies are required to determine whether further caries activity is arrested after treatment with dentine bonding procedures.
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Hahn P, Lindsten T, Lyubarsky A, Ying GS, Pugh EN, Thompson CB, Dunaief JL. Deficiency of Bax and Bak protects photoreceptors from light damage in vivo. Cell Death Differ 2004; 11:1192-7. [PMID: 15272317 DOI: 10.1038/sj.cdd.4401486] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Photoreceptors of bax(-/-)bak(-/-) but neither bax(-/-) mice nor bak(-/-) mice are protected from developmental apoptosis, suggesting that bax(-/-)bak(-/-) photoreceptors may also be protected from pathologic apoptosis. To test this possibility, we exposed bax(-/-)bak(-/-) and bax(-/-) mice to bright light, which normally induces photoreceptor death. Photoreceptors in bax(-/-)bak(-/-) mice were protected from death compared to bax(-/-) mice as indicated by a reduction in the number of TUNEL-positive photoreceptor nuclei 24 h following light damage and almost complete preservation of photoreceptors 7 days following light damage. These results provide the first in vivo evidence that combined deficiency of Bax and Bak can rescue cells from a pathologic stimulus more effectively than Bax deficiency and suggest that combined deficiency of Bax and Bak may also protect cells from other insults.
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Hahn P, Bultmann C. [Results after staged reconstruction of the flexor pollicis longus tendon]. HANDCHIR MIKROCHIR P 2003; 35:358-62. [PMID: 14681766 DOI: 10.1055/s-2003-44678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The objective of this study was to evaluate results after staged reconstruction of the flexor pollicis longus tendon (FPL) and to compare the results with literature. The advantages and disadvantages of staged reconstruction with a total duration of therapy of four months are discussed and theoretically compared with the simple and fast alternative, the arthrodesis of the interphalangeal joint (IP) of the thumb. The results of 22 patients from 1993 until 2000, 16 of which could be re-examined, are presented. Clinical parameters (grip strength and motion) were evaluated as well as the DASH score. In all cases a long graft to the forearm was used. The second operation usually followed eight weeks after the first operation. The results show a sufficient function in 75 % of the cases (scoring system of Buck-Gramcko et al.), which is paralleled by a median of 11 in the DASH score. The study shows that staged reconstruction can produce satisfactory results even in thumbs. The results are influenced negatively by persistent flexion contractures, insufficiency of annular pulleys and ailments after algodystrophy, which can be seen as indicator of the severity of the initial injury.
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Abstract
The extensor mechanism of the hand consists of different tendons, originating from extrinsic and intrinsic muscles of the hand and forearm. Because of their course near to skin and bone separated only by a thin layer of paratenon, they are very sensitive to injuries and adhesions. Treatment protocols have to be adapted according to the different zones. This paper explains the basic principles of rehabilitation in extensor tendon injuries.
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Hahn P, Jacobs C, Müller-Zimmermann A. [Rehabilitation after flexor tendon surgery]. DER ORTHOPADE 2003; 32:365-9. [PMID: 12743684 DOI: 10.1007/s00132-003-0458-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
During the last 20 years there have been significant innovations in injury repair and aftercare for patients who sustain zone 2 flexor injuries. Based on improvements in our understanding of the mechanism of repair, new differentiated concepts could be developed. Active extension, passive flexion as introduced by Kleinert is still the standard in flexor tendon surgery. New stronger suture techniques allow immediate active flexion. The purpose of this article is to review the current concepts of flexor tendon and pulley repair as well as reconstruction of these structures and the rehabilitation programs for tenolysis.
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Gurtsevich VE, Shcherbak LN, Novikova EV, Hahn P, Belousova NV, Arkhipov VV, Grasser FA, Müller-Lantzsch N, Pavlish OA. [Structural and functional features of Epstein-Barr virus LMP-1 gene in patients with anaplastic carcinoma of the nasopharynx in Russia]. VESTNIK ROSSIISKOI AKADEMII MEDITSINSKIKH NAUK 2002:53-9. [PMID: 11882974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Epstein-Barr virus (EBV) is known to be closely associated with the development of anaplastic nasopharyngeal carcinoma (NPC) in some malignancy endemic regions in South-East Asia. LMP1 gene is one of the EBV latent genes, which encodes a latent membrane protein. LMP1 gene is thought to be a classical oncogene since it morphologically transforms cells in vitro and induces tumors in experimental animals in vivo. LMP1 is one of a few genes which is expressed in NPC tissues. It was first shown that C-terminus of LMP1 gene obtained from NPC patients in South-East Asia contained a deletion of 30 base pairs (bp). However, this deleted LMP1 gene was then found in the EBV isolates persisting among healthy virus carriers and patients with other EBV-associated abnormalities from both NPC endemic and non-endemic regions. The aim of this investigation was to accomplish a molecular biological analysis of EBV LMP1 genes obtained from Russian NPC patients. To this end, the authors isolated and sequenced the LMP1 clones amplified from the tumor tissues from 7 NPC patients at the N. N. Blokhin Russian Cancer Research Center and primary blood lymphocytes (PBL) from 6 healthy donors. As a result, the authors could not find the deletion of the above-mentioned 30 bp in NPC LMP1 clones, but could in one healthy donor (PBL-2). A functional analysis revealed no significant differences between LMP1 variants with or without 30 bp deletion in their capacity to activate NF kappa B and jun/AP-1 transcription factors. Nevertheless, Russian NPC-derived LMP1 variants as compared with those from PBLs featured some specific amino acid exchanges. These data indicate that the 30 bp deletion of LMP1 gene is not a factor that predisposes to NPC in Russia.
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Nicholls J, Kremmer E, Meseda CA, Mackett M, Hahn P, Gulley ML, Brink A, Swinnen LJ, Greenspan J, De Souza Y, Grässer F, Sham J, Ng MH, Arrand JR. Comparative analysis of the expression of the Epstein-Barr virus (EBV) anti-apoptotic gene BHRF1 in nasopharyngeal carcinoma and EBV-related lymphoid diseases. J Med Virol 2001; 65:105-13. [PMID: 11505451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Epstein-Barr virus (EBV) has been identified in a wide range of neoplastic and non-neoplastic disorders. The EBV open reading frame BHRF1 encodes a protein with partial sequence and functional homology to the anti-apoptotic onco-protein Bcl-2 and may therefore have a role in the proliferation of EBV positive cells. We have developed a rat monoclonal antibody against pBHRF1, which can detect BHRF1 in paraffin sections. While a number of mutant versions of BHRF1 were recognised, the monoclonal did not detect the BHRF1 homologue encoded by Herpesvirus papio or two mutants with deletions in the BH2 region. This novel rat monoclonal antibody (6A9) was used to examine tissue sections from 39 cases of non-keratinising undifferentiated nasopharyngeal carcinoma (NPC), 6 cases of metastatic NPC, 7 cases of EBV-positive NPC with squamous differentiation from Chinese patients, 15 cases of EBV-positive post-transplant lymphoproliferative disorder (PTLD), 6 EBV-containing lymphoblastoid cell lines, and 2 cases of oral hairy leukoplakia (OHL). In 11 cases of undifferentiated NPC, RT-PCR data were available for comparison with the immunohistochemistry. Both cases of OHL and two cases of LCL were positive for BHRF1 but none of the PTLD showed positive staining. All cases of undifferentiated NPC were positive for Bcl-2 but only one BHRF1 positive cell was identified in 1 of 39 cases of primary undifferentiated NPC. The 6A9 antibody produced less background staining and no nuclear positivity compared with the commercially available mouse monoclonal 5B11. It is concluded that BHRF1 can not be detected by immunohistochemistry in NPC and therefore it appears not to play a significant anti-apoptotic role in the progression of this EBV-associated tumour. The 6A9 monoclonal appears to be superior to 5B11 for the detection of pBHRF1 in tissue sections.
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Gernhardt CR, Kielbassa AM, Hahn P, Schaller HG. Tensile bond strengths of four different dentin adhesives on irradiated and non-irradiated human dentin in vitro. J Oral Rehabil 2001; 28:814-20. [PMID: 11580819 DOI: 10.1046/j.1365-2842.2001.00758.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study evaluated the influence of irradiation on dentin bond strength. Sixty irradiated and 60 non-irradiated human third molars were used. The irradiation dose of 60 Gy was fractionally applied over 6 weeks (2 Gy day(-1), 5 days week(-1). All teeth were prepared in a special manner allowing the simulation of intra-pulpal pressure and dentin perfusion. Dentin specimens with a thickness of 2.0 mm were obtained under standardized conditions. The specimens were randomly assigned to four experimental groups. Tensile bond strength of four different dentin bonding agents (Scotchbond 1, Solobond Plus, Prime&Bond 2.1 and Syntac) was evaluated using an Instron Universal testing machine. Pairwise comparison did not show any significant differences between the irradiated and non-irradiated groups. The influence of the different dentin adhesives was significant (P=0.0001; ANOVA). Compared with Solobond Plus and Prime&Bond 2.1, the use of Scotchbond 1 resulted in a significantly higher tensile bond strength in non-irradiated specimen (P< 0.05; closed test procedure based on Kruskal-Wallis test). Within the limitations of an in vitro study, it can be concluded that adhesive restoration procedures can be successfully used in patients irradiated for cancer of the head and neck.
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Kallay E, Pietschmann P, Toyokuni S, Bajna E, Hahn P, Mazzucco K, Bieglmayer C, Kato S, Cross HS. Characterization of a vitamin D receptor knockout mouse as a model of colorectal hyperproliferation and DNA damage. Carcinogenesis 2001; 22:1429-35. [PMID: 11532865 DOI: 10.1093/carcin/22.9.1429] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The vitamin D receptor knockout (VDR-KO) mouse presents with a skeletal phenotype typical for complete lack of genomic 1,25-dihydroxycholecalciferol effects. Our previous data from human colorectal tissue suggest that the steroid hormone and its receptor may have protective function against tumour progression. In order to investigate the relevance of the vitamin D system for pre-malignant site-directed changes in the colon, we characterized the amount and site-specific distribution of the VDR along the large intestine in wild-type (WT), heterozygote (HT) and KO mice. We also evaluated expression of proliferating cell nuclear antigen (PCNA), of cyclin D1 and the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative stress. In colon ascendens, proliferative cells were dispersed all along the crypt and expression levels of all three markers were high in WT mice. A decrease of VDR expression did not affect expression significantly. In colon descendens, however, fewer proliferative cells were solely located in the lower third of the crypt, and an inverse relationship between VDR reduction, PCNA positivity and cyclin D1 expression was found in HT and KO mice. In parallel to enhanced proliferation a highly significant increase of 8-OHdG positivity occurred. Therefore, the sigmoid colon of VDR-KO mice, fed on an appropriate lactose/calcium-enriched diet to alleviate impaired calcium homeostasis-related phenotypic changes, is an excellent model for investigating induction and prevention of pre-malignant changes in one of the hotspots for human colorectal cancer incidence.
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