bluuebunny/crossref_metadata_2025 huggingface dataset:
Immortalization of human corneal endothelial cells using electroporation protocol optimized for human corneal endothelial and human retinal pigment epithelial cells
Authors: Bednarz Jürgen , Teifel Michael , Friedl Peter , Engelmann Katrin
Published: March 2003

Purpose: In this study we established a protocol for transfection of human corneal endothelial and human retinal pigment epithelial cells. This protocol was used for immortalization of human corneal endothelial cells.

Methods: Transfection was performed by means of electroporation. For immortalization a plasmid encoding large and small SV40 T‐antigen was used.

Results: The established electroporation protocol was suitable for both cell types. This protocol was used for transfection of human corneal endothelial cells with a plasmid containing the early region of SV40. The transfected cultures exibited an increased life‐span before they entered crisis. One culture recovered from crisis and was cultivated for 300 population doublings. The cells exhibited an in vivo‐like morphology usually lost during cell culture.

Conclusions: We describe for the first time a culture of SV40 transfected human corneal endothelial cells which recovered from crisis and can therefore be regarded as immortalized.
Mohs' micrographic surgery for basal cell carcinomas on the eyelids and medial canthal area. II. Reconstruction and follow‐up
Authors: Lindgren Gun , Lindblom Bertil , Larkö Olle
Published: March 2003

Purpose: To report our experience of reconstruction and follow‐up of eyelid basal cell carcinomas treated with Mohs' micrographic technique.

Methods: Sixty‐four periocular basal cell carcinomas, with a high risk of recurrence in one or more aspects with regard to location, size, morphology or prior treatment, were excised using Mohs' micrographic technique. All ensuing defects were repaired. The cases were followed prospectively for up to ten years. All complications and interventions were documented during the follow‐up period.

Results: The average size of the defect before repair was 21 mm (range 5–45 mm). The mean follow‐up time was 49 months (range 3–120). The recurrence rate was 5% (3 of 64 cases). The three recurrences occurred after one, four and six years, respectively.

Conclusions: The recurrence rate of high risk tumours reported in this study was less than reported with other modes of treatment and comparable with that in other studies using Mohs' micrographic technique.
A DIDMOAD syndrome family with juvenile glaucoma and myopia findings
Authors: Bekir Necdet A. , Güngör Kivanç , Güran Şefik
Published: March 2003

ABSTRACT. We present here two DIDMOAD syndrome cases (Diabetes Mellitus, Diabetes Insipidus, Optic Atrophy, Deafness) in a Turkish family. In the examination of the propositus who had consanguineous parents, diabetes mellitus, diabetes insipidus, optic atrophy, and deafness were observed in addition to myopia, juvenile glaucoma, posterior polar cataract, and dilatation of the urinary tract. Diabetes mellitus, diabetes inspidus, optic atrophy, deafness, myopia, and ventricular septal defect were observed in his elder brother. Juvenile onset diabetes mellitus, congenital glaucoma, deafness, and heart disease were the other remarkable findings observed in relatives to this family. Juvenile glaucoma, posterior polar cataract observed in our propositus, and myopia in both our DIDMOAD syndrome cases are the first ophthalmic manifestations described in the DIDMOAD syndrome.
Reliability of computerized perimetric threshold tests as assessed by reliability indices and threshold reproducibility in patients with suspect and manifest glaucoma
Authors: Bengtsson Boel
Published: March 2003

Background: High reproducibility of test measurements is often considered an indication of high reliability of test results. The aim of the current study was to analyse the role of the traditional perimetric reliability indices, False Negative and False Positive responses, and Fixation Losses, as indicators of test reliability in comparison with threshold reproducibility in patients with suspect or manifest glaucoma.

Methods: Perimetry was performed in one eye in each of 76 patients. Each eye was tested twice within approximately one week using the Humphrey II 30‐2 S
ita S
tandard program. Frequencies of False Positive and False Negative answers, and rates of Fixation Losses were related to threshold reproducibility and to general field status as expressed by Mean Deviation from age‐normal threshold values using stepwise multiple linear regression analysis.

Results: Substantial field loss was associated both with low threshold reproducibility (p<0.0001) and with increased frequency of False Negative answers (p=0.047). The traditional reliability indices contributed marginally compared to amount of field loss when predicting threshold reproducibility; the coefficient of determination decreased non‐significantly from 0.37 to 0.33 when excluding the three reliability indices as explanatory variables from the regression model. Frequencies of False Positive answers and Fixation Losses showed no association to field status or to threshold reproducibility.

Conclusion: Reliability of visual field test results in patients with glaucoma expressed as threshold reproducibility, can be predicted by amount of field loss alone, and traditional patient reliability indices contribute surprisingly little in this regard.
The results of cataract extraction and intraocular lens implantation in patients with Behçet's disease
Authors: Süllü Yüksel , Öge İhsan , Erkan Dilek
Published: March 2003

Purpose: To evaluate the results of extracapsular cataract extraction (ECCE) and intraocular lens (IOL) implantation in patients with Behçet's disease.

Methods: Retrospective study was based on 19 uveitic eyes of 12 patients with Behçet's disease who underwent classic ECCE with IOL implantation in 5 eyes and phacoemulsification with IOL implantation in 14 eyes between 1993–1999.

Results: In eyes with Behçet's uveitis 0.5 or better postoperative visual acuity was found in 21% at the end of mean 34.2±4.6 (range 5 to 66) months follow‐up. The most frequent postoperative complications were posterior capsule opacification in 9 (47%), posterior synechiae in 5 (26%), anterior synechiae in 3 (16%). Anterior and posterior synechiae in the phacoemulsification group were less than those in the ECCE group (respectively p<0.05 and p<0.01).

Conclusions: In eyes with chronic Behçet's uveitis, cataract extraction and IOL implantation by phacoemulsification had fewer postoperative complication than ECCE, but most of the patients had low visual acuity due to preoperatively existing optic atrophy and/or inflammatory degeneration or edema of macula.
Consumption of glaucoma medication
Authors: Calissendorff B. M.
Published: March 2003

ABSTRACT. During recent decades consumption of antiglaucoma drugs has shown a steady increase in the Nordic countries. The cost increase can partly be explained by the use of newer, more expensive drugs. The increase in daily doses, however, is relatively much larger than the corresponding ageing of the population. There are large national and regional differences. Measured in daily defined doses (DDD) the consumption of glaucoma medication is almost three times as high in Sweden as in Denmark. Within all the Nordic countries there exists up to more than two‐fold regional differences between high‐ and low‐consuming counties. The new classes of IOP‐lowering drugs have been very quickly adopted. Statistical data indicate that adding new drugs is more common than switching to a new therapy.
A child with Muscle‐Eye‐Brain disease
Authors: Fahnehjelm Kristina Teär , Ygge Jan , Engman Mona‐Lisa , Mosskin Mikael , Santavuori Pirkko , Malm Gunilla
Published: March 2003

ABSTRACT. Purpose: To describe a child with Muscle‐Eye‐Brain disease (MEB), one of three types of congenital muscular dystrophy associated with ocular abnormalities.

Methods: Case report.

Results: The child showed severe visual impairment due to progressive myopia and retinal degeneration, a pachygyria‐type of migration disorder of the brain with a nodular cortical surface, i.e. cobblestone cortex, as well as muscular weakness and severe mental retardation.

Conclusion: Ophthalmological assessments are important to help to diagnose and follow children with congenital muscular dystrophy.
Exfoliation (pseudoexfoliation) syndrome: toward a new understanding
Authors: Ritch Robert , Schlötzer‐Schrehardt Ursula
Published: March 2003

Exfoliation (pseudoexfoliation; PEX) syndrome is the single most common identifiable cause of open‐angle glaucoma, however, very few investigators are engaged in basic research on this disease. To stimulate the field, the First International Think Tank on Exfoliation Syndrome was held in New York in July 1999, comprising clinicians and scientists. This report is a summary of the proceedings of this meeting.
Tear functions in patients with pinguecula
Authors: Oguz Halit , Karadede Sezin , Bitiren Muharrem , Gurler Bulent , Cakmak Mehmet
Published: March 2003

ABSTRACT. Purpose: To investigate the tear flow, tear film stability and condition of mucus in patients with pinguecula.

Methods: The Schirmer I and ferning tests were performed and break‐up time (BUT) was determined in 57 patients with pinguecula [random eyes; 34 males and 23 females, 18 to 70 years of age (mean±SD: 39.1±13.5 years)] and in 57 age‐matched subjects (control) [random eyes; 35 males and 22 females, 11 to 70 years of age (mean±SD: 37.8±15.2 years)], and the test results were statistically analysed.

Results: The mean Schirmer test value was 22.72±12 mm in the eyes with pinguecula and 22.7±8.5 mm in the control eyes. There was no statistically significant difference (t=0.01, p=0.99) between the groups. The mean BUTs were 11.42±6.89 s in the eyes with pinguecula and 15.46±5.85 s in the control eyes. Comparison of BUTs between the groups revealed a statistically significant difference (t=3.37, p=0.0010). Also, ferning types were found to be significantly abnormal in the eyes with pinguecula (p<0.01).

Conclusion: The alteration in the mucin layer is a possible change inducing pinguecula formation, or it may reflect an already existing pathology in the cells on the ocular surface.
Autologous blood injection for marked overfiltration early after trabeculectomy with mitomycin C
Authors: Okada Koji , Tsukamoto Hidetoshi , Masumoto Makiko , Jian Koji , Okada Mayumi , Mochizuki Hideki , Mishima Hiromu K.
Published: March 2003

ABSTRACT. Purpose: After trabeculectomy with mitomycin C, extremely low intraocular pressure (IOP) with excess filtration may cause hypotonous maculopathy in the early postoperative period. We evaluated the effect of injecting autologous blood on reversing early postoperative marked hypotony after trabeculectomy with mitomycin C.

Methods: Trabeculectomy with mitomycin C was performed in 258 eyes between 1994 and 1998. Peribleb autologous blood injection was performed in five eyes in which pressure patches were ineffective in reversing excess filtration. Approximately 0.1 to 0.3 ml of whole unclotted blood was slowly injected at least 3 mm from the edge of the flap using a sterile 27‐gauge needle.

Results: None of these eyes developed hypotonous maculopathy after injection. After a mean 31‐month follow‐up, all eyes had well‐controlled IOP and visual acuity in three eyes was much improved. Postoperative complications included mild IOP elevation in one eye treated with laser suturelysis, and fibrinous pupillary membrane in one eye.

Conclusion: In the early postoperative period, autologous blood injection is effective in reversing excess filtration.
The short‐term effect of latanoprost on intraocular pressure and pulsatile ocular blood flow
Authors: Georgopoulos Gerasimos T. , Diestelhorst Michael , Fisher Robert , Ruokonen Peter , Krieglstein Guenter K.
Published: March 2003

Purpose:  There is evidence that ocular blood flow plays a critical role in the clinical course of glaucoma. Any reduction in ocular blood flow due to topical antiglaucoma treatment should therefore be avoided. This study aimed to evaluate the short‐term effect of local latanoprost application on ocular hemodynamics.

Methods:  Intraocular pressure (IOP), ocular pulse amplitude (OPA), ocular pulse volume (OPV), systemic blood pressure, heart rate and the pulsatile component of ocular blood flow (POBF) were recorded using a pneumotonometer linked to the Langham Ocular Blood Flow System in 24 patients in a prospective, open‐label study before and after 1 week of topical latanoprost application in both eyes. Twenty of the subjects had primary open‐angle glaucoma and four had ocular hypertension.

Results:  After 1 week of latanoprost treatment, IOP decreased significantly 6.2 ± 2.9 mmHg in OD (P < 0.001) and 6.2 ± 3.2 mmHg in OS (P < 0.001). Pulsatile OBF increased significantly by 201.2 ± 167.4 µL/min in OD (P < 0.001) and 203.8 ± 187.3 µL/min in OS (P < 0.001). Ocular pulse amplitude and OPV showed statistically significant increases (P < 0.05 and P < 0.001 respectively). Blood pressure and heart rate did not change significantly.

Conclusion:  Our results indicate that 1 week after latanoprost application, POBF, OPA and OPV were significantly increased in the eyes treated. More information on the perfusion of the optic nerve head is needed before the relevance of these findings to optic nerve head blood flow can be interpreted correctly.
Orbital intramuscular haemangioma
Authors: Christensen Steen Rugaard , Børgesen Svend Erik , Heegaard Steffen , Prause Jan Ulrik
Published: March 2003

Purpose:  To present the clinical and histopathological characteristics of an intramuscular haemangioma in the extraocular muscles.

Methods:  In 1989, an otherwise healthy 21‐year‐old female developed proptosis of the left eye. Clinical examination revealed a painless, non‐compressible, retrobulbar lesion. No discoloration of skin or conjunctiva could be observed. The patient had no history of head injury. She underwent surgery three times over a period of 9 years, without reaching a diagnosis. The tumour increased slowly in size despite the operations and MR imaging suggested a tumour of angiomatous origin. Finally, radical surgery was performed with enucleation of the left eye and excision of affected extraocular muscles.

Results:  Histopathological examination of the removed orbital tumour showed a mixed type intramuscular haemangioma involving four extraocular muscles.

Conclusion:  We report the first case of an intramuscular haemangioma of the orbit.
Analysis of mean retinal transit time from fluorescein angiography in human eyes: normal values and reproducibility
Authors: Bjärnhall G. , Mäepea O. , Sperber G. O. , Lindén C. , Mönestam E. , Alm A.
Published: March 2003

Objective:  To evaluate three different techniques to quantify retinal blood flow transit times in normal human eyes from fluorescein angiograms.

Subjects and Methods:  Fluorescein angiograms were recorded on two different occasions in 18 normal individuals with a scanning laser ophthalmoscope. The angiograms were digitized (5 frames per second) and the images were aligned. Mean transit times (MTT) were analysed with a newly developed technique based on an impulse‐response analysis (MTTIR) and again with the conventional technique (MTTSLOPE). Arterio‐venous passage times (AVP) were also calculated.

Results:  At the first determination, mean values (SD) for MTTIR, MTTSLOPE, and AVP were 3.22 (0.78), 4.88 (1.86), and 1.46 (0.57) seconds, respectively. Detection of an increase of 25% with a power of 80% requires groups of 12, 86 and 17 individuals for the three techniques, respectively.

Conclusions:  Mean transit time is a well‐defined physiological parameter. The technique based on impulse‐response analysis allows for analysis of even badly defined dye curves. We found this technique to be superior to the conventional technique in terms of reproducibility.
Retinal arteriolar obstruction with progestogen treatment of threatened abortion
Authors: Lanzetta Paolo , Crovato Sabrina , Pirracchio Angelo , Bandello Francesco
Published: March 2003

Purpose:  To describe a case of a retinal arteriolar occlusion associated with progestogen treatment of threatened abortion.

Methods:  Case report.

Results:  A 30‐year‐old woman who had received a 2‐week course of high dose intramuscular progestogen for a threatened abortion presented with a paracentral scotoma in her right eye and occlusion of a small arteriole adjacent to the macula. There were no major subsequent variations in haemostasis and pre‐existing systemic diseases were excluded.

Conclusions:  Retinal arteriolar occlusion may be associated with high dose progestogen‐only therapy in pregnant women.
The macular thickness and volume in glaucoma: an analysis in normal and glaucomatous eyes using OCT
Authors: Giovannini A. , Amato G. , Mariotti C.
Published: March 2003

Purpose:  To evaluate macular volume in normal and glaucomatous eyes using Optical Coherence Tomography (OCT).

Methods:  Fifty eyes of 30 patients (age: 49–68); 20 eyes normal, 15 eyes with early glaucoma and 15 eyes with advanced glaucoma have been studied with the commercially available OCT unit (OCT 2000) (Humphrey Zeiss, Dublin, CA, USA). All eyes were examined at a scan length of 3.44 mm vertically across the fovea. OCT macular retinal thickness maps were used to calculate macular volume.

Results:  We observed significant differences between groups. Normals (7.35 ± 0.455 mm3) and early glaucoma (7.09 ± 0.475 mm3), each had significantly greater volume than subjects with advanced glaucoma (6.678 ± 0.455 mm3).

Conclusions:  Volumetric analysis of macular thickness with OCT tomograms may be a useful method of documenting and monitoring patients with early glaucoma and advanced glaucoma. In our analysis, and according to the observations of other authors, OCT macular volumes correlates significantly with glaucoma status.
Oral lichen planus has a high rate of TP53 mutations. A study of oral mucosa in Iceland
Authors: Ögmundsdóttir Helga M. , Hilmarsdóttir Hólmfríður , Ástvaldsdóttir Álfheiður , Jóhannsson Jóhann Heiðar , Holbrook W. Peter
Published: March 2003

Oral squamous cell carcinoma (OSCC) is a world‐wide health problem. In addition to external exposure (smoking and alcohol), certain oral lesions may increase the risk of oral cancer (e.g. leukoplakia, erythroplakia, and oral lichen planus). TP53 has been implicated in OSCC, but there are limited studies of mutations in premalignant oral lesions. In this study, 55 samples from OSCC, 47 from hyperkeratotic (HK) oral mucosa, clinically diagnosed as white patches, 48 samples from oral lichen planus (OLP), and 12 biopsies from normal oral mucosa were studied immunohistochemically for expression of TP53 protein. From all the carcinoma samples and selected non‐malignant samples showing moderate or strong TP53 protein expression, malignant cells or TP53‐positive nuclei were microdissected and screened for mutations in exons 5–8 by constant denaturation gel electrophoresis. Moderate to strong TP53 protein staining was seen in 56% of OSCC, 32% of OLP but only in 13% of HK. All OLP samples showed a characteristic pattern of positive nuclei confined to the basal layer, whereas TP53 staining was seen in suprabasal nuclei in HK. Mutation rate was 11 out of 52 for OSCC, three out of 20 tested for HK and, remarkably, nine out 27 tested for OLP. There was no correlation between TP53 protein staining and TP53 mutations. No associations were found with anatomical sites or disease progression. The unexpectedly high mutation rate of OLP might explain the premalignant potential of this lesion.
Hypoxia and reoxygenation of brain microvascular smooth muscle cells in vitro: cellular responses and expression of cerebral amyloid angiopathy‐associated proteins
Authors: Wang Zhenzhen , Wu Dafang , Vinters Harry V.
Published: March 2003

Hypoxia is known to cause complex cascades of physiological, biochemical, and morphological changes in the brain. Cerebral microvascular smooth muscle cell (MV‐SMC) damage may occur following hypoxic conditions and lead to SMC dysfunction. However, little is known about the exact cellular and molecular responses of these cells to hypoxia. To partly address these questions, MV‐SMC were isolated from human brain, cultured and placed in conditions of ambient hypoxia (H) and hypoxia followed by reoxygenation (H/R). Cell morphology, proliferation, and the expression of amyloid precursor protein (APP) and cystatin C peptide were investigated and compared (after induction of hypoxia) between cerebral MV‐ and human aortic SMC. Our results show that MV‐SMC proliferation was inhibited after 48 h of hypoxia and H/R, whereas aortic SMC proliferation was stimulated after 48 h of hypoxia and H/R. Hypoxia and H/R induced an increase of intracellular APP and cystatin C expression in both types of SMC, though the effect of H and H/R on APP upregulation was quantitatively more robust in MV‐SMC than aortic SMC. Patterns of hypoxia‐induced APP upregulation in SMC differed significantly from those found in cultured neuronal cells (PC12, NT2). These results suggest that hypoxia and H/R‐induced APP and cystatin C upregulation appear to occur independently of the inhibition of cerebral MV‐SMC proliferation. Overexpression of APP and cystatin C in response to hypoxia may thus represent an initiating event in the pathogenesis of amyloid angiopathy, or mediate progression of this microvascular lesion.
A case of ovarian endometrioid adenocarcinoma with yolk sac tumor component in a postmenopausal woman
Authors: Kamoi Seiryu , Ohaki Yoshiharu , Mori Osamu , Okada Susumu , Seto Mariko , Matsushita Norihiro , Kawamura Takashi , Araki Tsutomu
Published: March 2003

The co‐existence of an endometrioid adenocarcinoma with an ovarian yolk sac tumor is very rare. Only eight cases have been reported in the English language literature. A 54‐year‐old postmenopausal woman with a 6‐month history of progressive abdominal distension was seen at our hospital. MR imaging revealed a large cyst with a solid intramural node. Serum α‐fetoprotein and CA125 levels were 13143 ng/ml and 170 U/ml, respectively. At laparotomy, a large tumor approximately 20 cm in diameter was found to occupy the abdominal cavity, adhering to the swollen appendix and part of the omentum. Microscopically, foci of endometrioid adenocarcinoma together with a yolk sac tumor component were observed within a large endometriotic cyst. Since the tumor was clinically staged 1c, the patient was given 500 mg of intraperitoneal carboplatin postoperatively, followed by five courses of combination chemotherapy consisting of cisplatin, etoposide and peplomycin at 4‐week intervals. The levels of both serum α‐fetoprotein and CA 125 decreased gradually to normal ranges and remained normal at the most recent follow‐up on 29 December, 2001. In contrast to a very poor prognosis of this tumor in previously reported cases, our patient showed no sign of recurrence during a 21‐month follow‐up period.
Pheochromocytoma of the urinary bladder
Authors: DORAN FIGEN , VARINLI SEYHAN , BAYAZIT YILDIRIM , BAL NEBIL , ÖZDEMIR SADULLAH
Published: March 2003

The case of a 65‐year‐old male with pheochromocytoma arising in the urinary bladder is presented. Clinical evaluation included ultrasonography, intravenous pyelography and computerized tomography (CT) scan. Transurethral resection of an exophytic tumor 1 cm in diameter was performed. The histological diagnosis was pheochromocytoma of the bladder. The evaluation and management of this type of tumor is discussed.
Stomach cancer highly expresses both initiator and effector caspases; an immunohistochemical study
Authors: YOO NAM JIN , KIM HONG SUG , KIM SU YOUNG , PARK WON SANG , KIM SANG HO , LEE JUNG YOUNG , LEE SUG HYUNG
Published: March 2003

Caspases play an essential role during apoptotic cell death. While caspases 8 and 10 act as initiator caspases of the extrinsic apoptosis pathway, caspase 9 acts as an initiator caspase of the intrinsic apoptosis pathway. Caspase 3 is considered to be the main effector caspase involved in both intrinsic and extrinsic pathways. Alteration of apoptosis is essential for cancer development. Thus, analysis of the expression status of caspases, the main executioners of apoptosis, in cancer tissues is needed for a sophisticated understanding of cancer biology. In the current study, we analyzed the expression of caspases 3, 8, 9 and 10 in 60 advanced gastric adenocarcinomas by immunohistochemistry using a tissue microarray approach. Immunopositivity was observed for caspase 3 in 57 (95%), caspase 8 in 56 (93%), caspase 9 in 54 (90%), and caspase 10 in 58 (97%) of the 60 cancers. While 46 cancers (77%) expressed all of the caspases examined, 14 cancers (23%) showed loss of expression in one or more caspases examined. Normal gastric mucosal cells showed no or weak expression of caspases 3, 8, 9 and 10. Taken together, these results suggest that stomach cancer cells in vivo may need caspase expression for apoptosis. Also, higher expression of the caspases in stomach cancer cells than in normal gastric mucosal cells suggests that apoptosis in susceptible stomach cancer cells might be easily triggered, thereby producing selective pressure to make more apoptosis‐resistant cells during tumor development.
Tissue integration of non‐submerged implants. l‐year results of a prospective study with 100 ITI hollow‐cylinder and hollow‐screw implants.
Authors: Buser D. , Weber H.‐P. , Lang N. P.
Published: March 2003

It has been postulated that the wound healing in a closed submerged location is one of the prerequisites for osseointegration of dental implants. The purpose of the present study was to evaluate the tissue integration of intentionally non‐submerged titanium implants inserted by a one‐stage surgical procedure. 100 ITI implants were consecutively placed in 70 partially edentulous patients. After a healing period free of masticatory loading for at least 3 months, the implants were examined. The clinical status showed for all implants neither detectable mobility nor signs of a peri‐implant infection. Therefore, prosthetic abutments were inserted, and the patients were restored with fixed partial dentures. All patients were regularly recalled at 3‐month intervals, and no patient dropped out of the study. Thus, all 100 implants were re‐evaluated 12 months following implantation. Plaque‐ and sulcus bleeding indices, probing depth, clinical attachment level, width of keratinized mucosa, and periotest scores were assessed. In addition, standardized radiographs were analyzed for the presence of peri‐implant radiolucencies and for the location of alveolar bone levels around the implants. Based on predefined criteria, the implants were classified as successful or failing. 98 implants were considered successful, and 1 implant failing. The remaining implant exhibited a peri‐implant infection requiring local and systemic antimicrobial treatment. The results of this short‐term study indicate that intentionally non‐submerged ITI implants yield a high predictability for successful tissue integration.
Estimation of angulation of Brånemark titanium fixtures from radiographic thread images
Authors: Sewerin Lb Paul
Published: March 2003

Identity of film positioning and of X‐ray beam angulation is essential for valid comparisons of marginal bone height around osseointegrated implants. The purpose of the present study was to analyze the possibilities of estimating fixture angulation in relation to film plane from the threads of Brånemark fixtures. 10 observers compared 62 images of fixtures with angulations ranging from 0" to ± 15" with a set of reference radiographs. Out of 620 recordings, 29% were right, and 71% differed by ≥ 1". The observers distinguished with great accuracy between negative and positive angulations. 81% of the recordings differed by 2" or less. It is concluded that the threads of Brånemark fixtures are helpful in controlling the identity of serial radiographs of implants. The test circumstances were ideal compared to clinical cases, and it is possible that accuracy will be less in patient cases.
Histological and histomorphometrical evaluation of tissue reactions adjacent to endosteal implants in monkey's
Authors: Gotfredsen Klaus , Rostrup Egill , Hjörting‐hansen Erik , Stoltze Kaj , Budtz‐jörgensen Ejvind
Published: March 2003

A qualitative and quantitative histological study of the initial healing response adjacent to 24 submerged and non‐submerged implants placed in the lower jaws of 6 monkeys is presented. The histomorphometric analysis showed no significant differences in mineralized bone‐implant contact length between submerged and non‐loaded non‐submerged titanium implants. The infrabony defects around some of the implants on the radiographs were significantly correlated to the histological measurements. Qualitatively, a greater number of gingival inflammation cells and a longer junctional epithelium were seen adjacent to non‐submerged implants without oral hygiene than were seen adjacent to non‐submerged implants with oral hygiene in the initial healing period.
The soft tissue response to titanium abutments retrieved from humans and reimplanted in rats. A light microscopic pilot study.
Authors: Sennerby L. , Lekholm U.
Published: March 2003

In order to test the soft tissue response to contaminated titanium components, 20 clinically retrieved abutment cylinders were inserted in the abdominal wall of 5 rats. Prior to insertion, 10 of the abutments had been contaminated for 1 min and the remaining components for 2 weeks. Five abutments of either group were ultrasonically cleaned in butanol and ethanol, whereas the remaining abutments were only rinsed in saline before being implanted. As controls, 5 newly manufactured abutments were used. After 6 weeks of healing, specimens were prepared of the components and surrounding tissues for morphological analysis. This showed an accumulation of macrophages and a reduction of the number of fibroblasts around the abutments that had been contaminated, irrespective of cleaning procedure, compared with the controls. It was concluded that the contaminated components induced an altered tissue response and that a similar reaction may occur in the clinical situation.
A longitudinal microbiological study on osseointegrated titanium implants in partially edentulotis patients
Authors: Leonhardt Å. , Adolfsson B. , Lekholm U. , Wikström M. , Dahlén G.
Published: March 2003

The aim was to longitudinally follow the colonization of putative periodontal pathogens on titanium implants in partially edentulous patients. Nineteen individuals, who were partially edentulous and were on the waiting‐list to be treated with titanium fixtures, were included in the study. They were treated for periodontal disease with oral hygiene instructions and supra‐ and subgingival debridement and were left for maintenance. Full‐mouth recordings of each patient were performed at baseline, including attachment level and probing pocket depth. Bleeding was provoked and visible plaque were registered. Subgingival samples were taken for examination of Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans. Bridge connection was completed 1 month after abutment connection. The bone level was registered on radiographs. The patients were followed with clinical registrations and subgingival samples at 6, 12, 24 and 36 months. No significant changes in pocket depth, attachment level, bleeding on probing or plaque score occurred during the experimental period. The number of individuals positive at teeth and abutments for the various bacterial species reached approximately similar levels at 6 months. No significant changes over time were seen. Comparison between bone height. seen on radiographs, at abutments after 2, 12 and 36 months gave only 3 sites with bone loss of > 0.5 mm. All these sites were found in one patient and were accompanied by P. intermedia.
Healing of implant dehiscence defects with without expanded polytetrafluoroethylene membranes: a controlled clinical and histological study and histological study
Authors: Palmer R. M. , Floyd P. D. , Palmer P. J. , Smith B. J. , Johansson C. B. , Albrektsson T.
Published: March 2003

Bone augmentation around implant fixtures using the technique of guided tissue regeneration has been described in a number of reports. The aim of this study was to evaluate bone fill around dehiscence defects at matched defects randomly allocated to test (expanded polytetrafluoroethylene; Gore‐Tex) or control treatments within the same patient. Six edentulous subjects were treated with overdentures supported by 2 fixtures ad modum Brinemark. In addition, 2 experimental 7 mm fixtures with nearly identical dehiscence defects on the labial aspect were placed in the anterior part of the mandible. Baseline defect heights ranged from 2.5 to 4.0 mm with 2 to 4 threads exposed. The test fixture dehiscence was covered with a Gore‐Tex membrane secured with a cover screw. The experimental fixtures were exposed after 5 months at stage 2 surgery and measurements and photographs repeated. The fixtures were then removed with a trephine and processed for histological evaluation. Regeneration of a hard tissue resembling bone was observed in 4 of 6 cases treated with Gore‐Tex, amounting to between 95 and 100% elimination of the dehiscence and total coverage of the threads. However, in one of these cases, histological evaluation showed that it was soft tissue and not bone, and in a further case soft tissue regeneration was apparent both clinically and histologically. In another case there was no significant regeneration at either test or control defects. Although there was a trend for the Gore‐Tex treated dehiscences to respond more favourably, the differences in clinical and histological measurements between test and control failed to reach statistical significance.
The use of a new bioresorbable barrier for guided bone regeneration in connection with implant installation. Case reports.
Authors: Lundgren D. , Sennerby L. , Falk H. , Friberg B. , Nyman S.
Published: March 2003

This report presents 4 cases with 6 implant exposures after the installation of Bråemark System® implants which called for treatment applying the guided bone regeneration technique. A bioresorbable barrier (GUIDOR® Matrix Barrier) was used to cover the defects, 4 defects with and 2 without the support of autologous bone chips. Complete bone filling was found in 4 (2 without and 2 with bone chips) and partial filling in 2 (with bone chips) of the treated defects, as registered at the abutment connection 6–7 months after surgery. Besides its ability to serve as a barrier for guided bone regeneration, it was found that the matrix barrier had the following properties; biocompatibility observed as uneventful tissue healing, malleability facilitating the clinical handling and ability to be resorbed within 6 to 7 months, as evaluated by clinical inspection. The observations of the present case reports indicate that the tested barrier may be used for guided bone regeneration in connection with implant installation. It is advisable, however, to use a supporting material to prevent barrier collapse, although bone regeneration can be achieved in certain situations without such material if the defect morphology is favourable.
Experimentally induced peri‐implant mucositis. A clinical study in humans.
Authors: Pontoriero R. , Tonelli M. P. , Carnevale G. , Mombelli A. , Nyman S. R. , Lang N. P.
Published: March 2003

The purpose of this study was to compare the clinical and microbiological (microscopic) parameters during the development of experimental gingigivitis and experimental peri‐implant mucositis. Twenty partially edentulous patients were treated for moderate to advanced periodontal disease. Following active periodontal therapy consisting of motivation, instruction in oral hygiene practices, scaling and root planing and periodontal surgery where indicated, IMZ oral implants were incorporated in posterior edentulous areas. After 3 months of healing, the prosthetic abutments were connected, and the patients were closely supervised for another 2 months of healing. At this time, baseline data were obtained. Re‐examinations were scheduled at 3 and 6 months. Following this, the patients were asked to refrain from oral hygiene practices for 3 weeks. At all examinations including the end of the period of no oral hygiene, the following clinical parameters were obtained: Plaque Index, Gingival Index and Sulcus Bleeding Index, all modified by Mombelli et al. (1987) probing pocket depths and recession in mm. Furthermore, submucosal/subgingival plaque samples were obtained and analyzed using phase contrast microscopy. At the end of the 3‐week period of plaque accumulation: optimal oral hygiene was reinstituted. There were no statistically significant differences between the mean values of all parameters at implant compared to tooth sites at any observation periods. The period of no oral hygiene demonstrated a similar cause‐effect relationship between the accumulation of bacteria1 plaque and the development of peri‐implant mucositis as established for the gingival units by the experimental gingivitis model.
Markers of primary mineralization are correlated with bone‐bonding ability of titanium or stainless steel in vivo
Authors: Braun G. , Kohavi D. , Amir D. , Luna M. , Caloss R. , Sela J. , Dean D. D. , Boyan B. D. , Schwartz Z.
Published: March 2003

Critical events in the adaptation of osseous tissues to implant materials involve initial calcification of the newly synthesized bone. Previous studies indicated that bone‐bonding but not nonbonding glass ceramics increase the matrix vesicle number, thereby compensating for delayed maturation of the extracellular organelles. The present study assessed whether this was also true for metal implants commonly used in orthopaedics and oral medicine. Bone‐bonding titanium (Ti) or nonbonding stainless steel (SS) implants were placed in the right tibias of Sabra rats following ablation of the marrow. At 3, 6, 14, and 21 days postinjury, newly formed endosteal bone in the treated and contralateral limbs was removed and matrix vesicle‐enriched membranes isolated. Alkaline phosphatase and phospholipase A2 specific activities and phosphatidylserine (PS) content were determined and compared with those of a nonsurgical control group. Results show that matrix vesicle alkaline phosphatase and phospholipase A2 activity and PS content was increased in the Ti‐implanted limbs at 6 (peak). 14, and 21 days, although at levels less than observed in normal ealing. Alkaline phosphatase activity remained elevated throughout the healing period. In contrast, these parameters were markedly inhibited in the SS‐implanted limbs with respect to Ti or to normal healing. Both implants altered the systemic response associated with marrow ablation. but in an implant‐specific manner. The results support the hypothesis that cells adjacent to bone‐bonding materials can compensate for negative effects on primary mineralization during osteogenesis, whereas cells adjacent to nonbonding materials either do not compensate or are further depressed. The data support the use of the rat marrow ablation model as a tool for rapid, initial assessment of biomaterials in bone.
The effect of mechanical intervention on jaw bone density. An experimental study in the rabbit.
Authors: Lundgren D. , Lundgren A. K. , Sennerby L.
Published: March 2003

The aim of this investigation was to test the hypothesis that jaw bone, subjected to mechanical intervention, will heal with increased density compared with conditions before the traumatic insult. The natural edentulous area between the incisor and the first molar on both sides of the maxillary jaw of 8 adult New Zealand white rabbits constituted the experimental model. On the test side, holes were drilled through the cortical plate and into the cancellous bone. No drilling was performed on the contralateral control side. One transversal ground section from each specimen, taken in the centre of and representing both the test and control site, was prepared to ensure that the same sagittal level of the jaw was represented. Morphometric measurements were performed and comprised assessments of the total cross‐sectional area of 1) the edentulous part of the jaw, 2) the cortical bone plates and 3) the bone trabeculae and marrow spaces of the cancellous bone. The mechanical intervention resulted in a substantial alteration of the bone tissue morphology, the most conspicuous change being a markedly increased number of bone trabeculae per cancellous bone unit. Thus, the area occupied by bone trabeculae was about twice as large in the test sites compared with the control sites (+103%), whereas the area occupied by bone marrow cavities and cortical bone was significantly smaller. The clinical implications of the findings for potential treatment of fragile bone tissues and bone sites intended for implant insertion are discussed.
A new method to obtain bone biopsies at implant sites peri‐operatively: technique and bone structure
Authors: Klinge B. , Johansson C. , Albrektsson T. , Hallströ H. , Engdahl T.
Published: March 2003

This study aims at evaluating an objective method for the description of bone structure in the human mandible. Human bone biopsies were harvested at mandibular implant sites prior to insertion of self‐tapping Mark II fixtures. Altogether 15 biopsies were taken from 12 patients. Three patients donated 2 biopsies each, one proximally and one distally taken. Ground sections of about 100μm thickness were prepared prior to microradiography. These sections were ground to a final thickness of about 10μm followed by histological staining. Histomorphometrical analyses were performed on the microradiographed plates and on the ground sections. On average there was a bone area of about 54% calculated on the microradiographed plates (the 100‐μm sections) versus a mean bone area of 62% light microscopically (the 10‐μm sections). Bone lengths were calculated on the 10‐μm sections in the central part (mid‐line) and on each side of the mid‐line, revealing a mean of 58% in the former case and a mean of 61% in the latter case. The amount of bone varied between individuals and in different locations of the same jaw. The postoperative healing period following fixture installation is standardized regardless of bone structure. It may in the future be appropriate to more individualize this healing period based on an objective bone quality score.
Measurements of distances related to the mandibular canal in radiographs
Authors: Lindh C. , Petersson A. , Klinge B.
Published: March 2003

Before implant surgery in the mandibular side segment, it is of utmost interest to locate the mandibular canal in radiographs to avoid interference with the neurovascular bundle during surgery. Six mandibular specimens were radiographically examined with 2 panoramic and 3 tomographic techniques. The distances between the superior border of the canal and the alveolar crest and between the mandibular base and the inferior border of the canal were measured. In addition, the height of the canal was measured. The measurements were performed by 3 or 4 observers and compared with measurements on contact radiographs of the same areas. Tomography gave more accurate values of the above distances than panoramic techniaues. The variation between observers in detecting the mandibular canal Aas large.
Influence of the sumastructure on the peri‐implant tissue; in beagle dogs
Authors: Hürzeler M. B. , Quiñones C. R. , Schüpbach P. , Vlassis J. M. , Strub J. R. , Caffesse R. G.
Published: March 2003

The purpose of this study was to compare clinical, radiographic and histological differences around titanium oral implants loaded with either acrylic‐veneered metal or ceramo‐metal fixed prostheses. Five beagle dogs were used in this investigation. At the beginning of the study, all mandibular premolars and first molars were extracted. After 3 months of healing, 2 Brånemark implants were installed on each side of the mandibles. Three months later, abutments were inserted on each implant and a daily oral hygiene regime was initiated. One month after abutment connection, the implants on one side of the mandible were restored with an acrylic‐veneered metal fixed prosthesis, whereas, on the other side a ceramo‐metal fixed prosthesis was inserted. The prostheses were constructed in occlusion with the maxillary first molars. The following clinical parameters were measured around each implant at this time (i.e., baseline), and thereafter, at monthly intervals up to 5 months: Plaque Index; Gingival Index; implant mobility (using the Periotest®); probing depth and clinical attachment level (using the Florida Probe®). In addition, standardized radiographs were taken at baseline and 5 months after insertion of the prostheses and evaluated by subtraction radiography. Another Brånemark fixture was installed on each side of the mandibles 3 months before the end of the study. These implants remained unloaded and submerged for the entire study period. Five months after prosthesis insertion, the animals were killed, and implants with their supporting peri‐implant tissues were processed for histological evaluation. Analyses of the clinical, radiographic and histometric parameters revealed no significant differences between the acrylic‐veneered and ceramometal loaded implants. All clinical and radiographic parameters remained stable over time. Histological comparison of the alveolar bone height levels around both loaded groups with those from the unloaded, submerged implants revealed that a similar and slight loss of bone height (approximately 0.6 mm) occurred on the loaded groups following abutment connection. It was concluded that both acrylic‐veneered metal and ceramo‐metal suprastructures appear to be suitable for the restoration of endosseous oral implants. Additional long‐term studies in humans, however, are needed evaluating both types of implant‐supported prostheses, in a variety of clinical conditions. before final restorative recommendations are made.
Mandibular single crystal sapphire implants: changes in crestal bone levels over three years
Authors: Fartash B. , Eliasson S. , Arvidson K.
Published: March 2003

A total of 190 single crystal sapphire implants, 85 short (4S9S) and 105 long (4S9L), were monitored with panoramic and intraoral radiographs for 3 years. The implants were used as abutments for overdentures in edentulous mandibles in 51 patients. Within the first year, 2 patients lost one implant each due to pain and lack of osseointegration. Neither was replaced and the superstructures remained stable. At baseline registration, i.e., immediately after the prosthetic installation, the bone height relative to the length of the implant was calculated. The mean bone implant score (BIS) was 63.55±1.34%(mean±SE). BIS decreased during the first year 62.18±1.51%. At the 2‐ and 3‐year recordings, the mean BIS were 61.81±1.58% and 61.73±1.63%, respectively. There were no statistically significant differences in BIS changes over the 3‐year period or between men and women. The decrease in mean BIS was greater for implants in the premolar region than in the incisor region and for short implants than for long implants.