Biomedical subjects

L Módis

Publications and source records attributed to L Módis.

At least 19 recordsLinked to original sources

PubMed2006

Corneal endothelial function after phacoemulsification using the fluid-based system compared to conventional ultrasound technique.

AIM: To quantitatively assess corneal endothelial changes after phacoemulsification with the fluid-based system compared to conventional ultrasound technique. METHODS: This prospective, randomized clinical study included patients with cataract who were randomly assigned either to have phacoemulsification with the fluid-based system (30 eyes of 30 patients--Group 1) or with traditional ultrasound (30 eyes of 30 patients--Group 2). Patients who were available at each follow-up visit (25 eyes in both groups) were enrolled in the statistical analysis. Endothelial function was evaluated by measuring central corneal thickness, central endothelial cell density (ECD), mean cell size, and coefficient of variation in cell size preoperatively, 10 days, 1 and 3 months, and 1 year after surgery. Statistical analyses were performed using two-way repeated measure ANOVA. RESULTS: An acute, reversible increase of central corneal thickness (CCT) was found 10 days after surgery, which was similar in both groups (P=0.35). ECD decreased, whereas mean cell size increased significantly immediately after surgery. However, the impairments were finished after 1 month. The alterations were similar in both groups (ECD: P=0.99; mean cell size: P=0.85). The coefficient of variation in cell size remained stable after surgery (P=0.08), and significant difference was not found between groups (P=0.99). The endothelial cell loss (ECL) was 6.5+/-8.4% in Group 1 and 6.5+/-11.7% in Group 2 (P=0.69). CONCLUSIONS: Corneal endothelial changes were similar using the fluid-based system compared to the traditional ultrasound technique. The fluid-based method proved to be as safe as conventional ultrasound in cataract surgery.

Aged↗

PubMed2005

Quantitative determination of hyaluronan content in cerebral aneurysms by digital densitometry.

OBJECT: Hyaluronan (HA) is a highly hydrated macromolecule; it is one of the essential components of the extracellular matrix (ECM) of the arteries and plays an important role in maintaining the biomechanical features of blood vessels. Although the potential contribution of HA in aneurysms of different vessels has been studied intensively, no data are available about the alteration of the HA content in the extracellular matrix of intracranial aneurysms. The aim of the study was to determine the hyaluronan content in the wall of human cerebral arteries. METHODS: A biotinylated aggrecan fragment that binds specifically to HA was used to stain samples from cerebral aneurysms (n = 11) to compare the HA content to non-aneurysmal arteries of patients who had intracranial aneurysm (n = 11), and to histologically normal arteries of patients who had expired from non-vascular diseases (n = 14). Digital microscopic densitometry was used for the quantitative analysis of the hyaluronan content in these samples. RESULTS: The highest level (169.5 +/- 7.9) was detected in aneurysms, while the HA-level of non-aneurysmal vessels was lower (130.2 +/- 16.8). Both vessel groups contained significantly higher HA than the normal cerebral arteries (32.9 +/- 2.1). CONCLUSIONS: Results suggest that an elevated hyaluronan level in the extracellular matrix may affect the cerebral arterial wall architecture. It is reasonable to suppose that the increased hyaluronan content creates a viscoelastic ECM which might improve the biomechanical resistance of the thinned vessel wall.

Adult↗

PubMed2005

[Clinicopathological characteristic of keratoglobus].

BACKGROUND: This study describes the clinical, topographical, pachymetrical, and histological features of a unique corneal disorder: keratoglobus. CASE REPORT: Ultrasound pachymetry proved that the structure of the cornea was evenly thinning towards the periphery. Histological examinations disclosed the absence of Bowman's membrane and the thinning of the stromal lamellae. CONCLUSION: On account of the thickness of the recipient's periphery, penetrating keratoplasty proved to be a reasonable surgical procedure in this case.

Child↗

PubMed2004

The expression pattern of hyaluronan synthase during human tooth development.

In previous studies, hyaluronan (HA) and its major cell surface receptor CD44 have been suggested to play an important role during tooth development. HA synthases (HASs) are the enzymes that polymerize hyaluronan. Data on the expression pattern of HASs during tooth development is lacking and the aim of the present study was to investigate the localisation of HAS by immunohistochemistry in human tooth germs from different developmental stages. The distribution pattern of HAS in the various tissues of the "bell stage" tooth primordia corresponded to that of hyaluronan in most locations: positive HAS immunoreactivity was observed in the dental lamina cells, inner- and outer-enamel epithelium. On the stellate reticulum cells, moderate HAS signal was observed, similar to the layers of the oral epithelium, where faint HAS immunoreactivity was detected. At the early phase of dental hard tissues mineralization, strong HAS immunoreactivity was detected in the odontoblasts and their processes, as well as in the secretory ameloblasts and their apical processes and also, the pulpal mesenchymal cells. The HAS signals observed in odontoblasts and ameloblasts gradually decreased with age. Our results demonstrate that hyaluronan synthesised locally by different dental cells and these results provide additional indirect support to the suggestion that HA may contribute both to the regulation of tooth morphogenesis and dental hard tissue formation.

Ameloblasts↗

PubMed2004

Expression of aquaporin isoforms during human and mouse tooth development.

Previously, we described the development of hyaluronan (HA) deposition in human tooth germ tissues that are consistent with water transport in different stages of tooth development. The aquaporins (AQP) constitute a family of membrane water channels that are expressed in many organs. However, there are no data available about the expression pattern of aquaporin water channels in dental structures. In the present study we have characterised the expression of six different aquaporin isoforms (AQP1-5, AQP-9) in developing human and mouse tooth germs by immunohistochemistry using isoform specific antibodies. In the "bell stage" AQP1 was expressed in endothelial cells of small vessels whereas no other structures of the tooth primordial were labeled. AQP2, AQP3 and AQP9 immunoreactivity was not observed in tooth germs, whereas strong AQP4 and AQP5 expression was observed in dental lamina, inner enamel epithelium, stratum intermedium, stellate reticulum and the outer enamel epithelium. Oral epithelium also exhibited AQP4 and AQP5 immunolabeling. During development of the matrices of the dental hard tissues AQP4 and AQP5 immunostaining was observed in the odontoblasts and their processes, as well as in the secretory ameloblast and their apical processes. Immunolabeling controls were negative. In conclusion, AQP4 and AQP5 are expressed in tooth germ tissues in early development in cells that previously have been shown to express HA and/or CD44, indicating that AQP water channels may play a role for ECM hydration during tooth development.

Animals↗

PubMed2004

[Tear examinations in primary peripheral lipid keratopathy].

The authors report a case of a bilateral peripheral lipid keratopathy, rising differential diagnostic points as well. After several year-long follow-up period the peripheral corneal opacity left the center unaffected. The diagnosis was confirmed by tear examinations which disclosed elevated level of fatty and phosphorous content compared to healthy control eyes.

Chromatography, Gas↗

PubMed2001

Okadaic acid-induced inhibition of protein phosphatase 2A enhances chondrogenesis in chicken limb bud micromass cell cultures.

The role of major cellular serine/threonine-specific protein phosphatases, protein phosphatase 1 and 2A, was investigated during chicken cartilage differentiation under in vitro conditions. Activity of protein phosphatase 2A decreased parallel to differentiation of chondrogenic cells, whereas activity of protein phosphatase 1 remained unchanged as assayed in the supernatants of the homogenised chicken limb bud micromass cell cultures. When okadaic acid, a potent inhibitor of protein phosphatase 1 and 2A was applied in 20 nM concentration for 4 h during the second and third culturing days, it significantly increased the size of metachromatic cartilage areas measured in 6-day-old colonies. Following okadaic acid treatments, a significant inhibition in the activity of protein phosphatase 2A was found, while the activity of protein phosphatase 1 was unaffected as measured an days 2 and 3. TRITC-phalloidin labelling demonstrated that okadaic acid disorganised actin filaments and induced rounding of chondrogenic cells. This deterioration of actin filaments was reversible. Electron microscopy and biochemical analysis of colonies revealed that the ultrastructure and major components of cartilage matrix remained unchanged under the effect of okadaic acid. Okadaic acid-treatment applied to cultures containing predominantly differentiated chondrocytes (after day 4) did not influence the cartilage formation. 3H-thymidine and bromodeoxyuridine incorporation-assays demonstrated enhanced cell proliferation in the okadaic acid-treated colonies compared to that of the untreated ones. Our results indicate, for the first time, that protein phosphatase 2A is involved in the regulation of chondrogenesis. Inhibition of protein phosphatase 2A with okadaic acid may result in increased chondrogenesis via modulation of proliferation and cytoskeletal organisation, as well as via alteration of protein kinase A-signaling pathway of the chondrogenic cells.

Actin Cytoskeleton↗

PubMed2001

Corneal thickness measurements with contact and noncontact specular microscopic and ultrasonic pachymetry.

PURPOSE: To evaluate the central corneal thickness values in normal and postkeratoplasty corneas with the new Topcon SP-2000P noncontact specular microscopic, contact specular microscopic, and the "common standard" ultrasonic pachymetry. METHODS: Central corneal thickness was determined in 119 eyes of 81 patients (73 normal eyes of 44 patients and 46 eyes after penetrating keratoplasty) first with a noncontact specular microscopic (Topcon SP-2000P; Topcon Corporation, Tokyo, Japan), then an ultrasonic (AL-1000; Tomey, Erlangen, Germany), and finally with a contact specular microscopic (EM-1000; Tomey, Erlangen, Germany) pachymetry two times each by the same investigator. RESULTS: Reliability of the central corneal measurements was equally high both in normal and in postkeratoplasty corneas with all of the instruments (Cronbach alpha = 0.99). Noncontact specular microscopic corneal thickness determination correlated significantly both with ultrasonic (r =.86, P <.0001) and contact specular microscopic pachymetry (r =.62, P <.0001). The ultrasonic pachymetry correlated well with the Tomey pachymetry (r =.69, P <.0001). The Topcon normal mean central corneal thickness value (542 +/- 46 microm) was 28 +/- 4 microm lower (P <.0001) compared with the ultrasonic data (570 +/- 42 microm), which was 68 +/- 1 microm lower (P <.0001) compared with Tomey thickness (638 +/- 43 microm). CONCLUSIONS: Central corneal thickness measurements with noncontact specular microscopic, contact specular microscopic, and ultrasonic pachymetry demonstrate that each of the instruments is reliable but cannot be simply used interchangeably.

Aged↗

PubMed2001

The distribution pattern of the hyaluronan receptor CD44 during human tooth development.

The aim was to investigate the expression pattern of the major cell-surface hyaluronan receptor CD44, as there are no existing data on its presence or absence in human dental structures at different developmental stages. Immunohistochemical localization of CD44 was studied using a monoclonal antibody, H3, that specifically recognizes an epitope in the common backbone of all CD44 isoforms. The dental lamina displayed a strong CD44 signal; the external enamel epithelium was negative. In the coronal region of the tooth germ the presecretory ameloblasts showed an intense reaction whereas the less differentiated inner enamel epithelial cells showed no signal at the cervical loop where they meet the external enamel epithelium. In the stellate reticulum a moderate reaction was detected. The secretory ameloblasts and the stratum intermedium showed a strong cell-surface CD44 signal. A strong signal was also observed on the odontoblasts and their processes. In the pulp, close to the odontoblastic layer, weak labelling was seen in the walls of capillary vessels. The distribution of CD44 in the human tooth germ corresponds to that of hyaluronan in most locations, suggesting that during tooth development this transmembrane protein plays an important part in hyaluronan-mediated events.

Age Factors↗

PubMed2001

Scanning-slit and specular microscopic pachymetry in comparison with ultrasonic determination of corneal thickness.

PURPOSE: To determine the central corneal thickness values in healthy eyes with the recently developed Orbscan scanning-slit system, contact and noncontact specular microscopic pachymetry and compare the results to conventional ultrasonic pachymetry. METHODS: In the following sequence, Orbscan, Topcon SP-2000P noncontact specular microscope, AL-1000 ultrasound, and Tomey contact specular microscope were used to record thickness values. Thirty-four healthy right corneas of 34 healthy subjects were investigated. RESULTS: Orbscan pachymetry correlated significantly with ultrasound (r = 0.64, p < 0.001), contact (r = 0.45, p < 0.001), and noncontact specular microscopy (r = 0.72, p < 0.001). Likewise, the Topcon SP-2000P noncontact specular microscopy pachymetry disclosed similar statistical results compared with ultrasound (r = 0.88, p < 0.001), and contact specular microscopy pachymetry (r = 0.76, p < 0.001). The mean central corneal thickness results were significantly higher ( p < or = 0.01) than ultrasonic values (580 +/- 43 microm) using the contact specular microscope (640 +/- 43 microm) or Orbscan system (602 +/- 59 microm) but were significantly lower ( p < 0.001) using the noncontact specular microscope (547 +/- 49 microm). CONCLUSIONS: The results indicate that the devices tested cannot be simply used interchangeably. For long-term patient follow-up, one specific instrument is recommended. Recently developed pachymetry machines are especially helpful when additional corneal data such as thickness profile, elevation maps, anterior chamber depth, and endothelial morphology are required.

Cornea↗

PubMed2001

Accuracy of in vivo carotid B-mode ultrasound compared with pathological analysis: intima-media thickening, lumen diameter, and cross-sectional area.

BACKGROUND AND PURPOSE: This study aimed to determine the correlation of in vivo ultrasound measurements of intima-media thickening (IMT), lumen diameter, and cross-sectional area of the common carotid artery (CCA) with corresponding measurements obtained by gross pathology and histology. METHODS: Sixty-six moribund neurological patients (mean age 71 years) underwent B-mode ultrasound of the CCA a few days before death. During autopsy, carotid specimens were removed in toto. Carotid arteries were ligated and cannulated for injection of a hydrophilic embedding material under standardized conditions. The carotid bifurcation was frozen and cut manually in 3-mm cross slices. Digital image analysis was carried out to determine the diameter and the cross-sectional area of the frozen slices of the CCA. IMT was assessed by light microscope. Ultrasonic and planimetric data were compared. RESULTS: Mean measurements of lumen diameter and cross-sectional area were 7.13+/-1.27 mm and 0.496+/-0.167 cm(2), respectively, by ultrasound, and 7.81+/-1.45 mm and 0.516+/-0.194 cm(2), respectively, by planimetric analysis of the unfixed redistended carotid arteries (R(2)=0.389 and 0.497). The mean IMT was 1.005+/-0.267 mm by ultrasound and 0.67+/-0.141 mm histologically, resulting in a mean difference of -31%. CONCLUSIONS: Transcutaneous B-mode ultrasound provides a reliable approach for in vivo measurements of the cross-sectional area and, less exactly, of the lumen diameter of the CCA. Compared with histological results, in vivo ultrasound measurements of the IMT are systematically larger.

Adult↗

PubMed2001

Mosaicplasty for the treatment of osteochondritis dissecans of the talus: two to seven year results in 36 patients.

An osteochondral defect (OCD) is known as a symptomatic lesion causing pain, recurrent synovitis, and altered joint mechanics most commonly in a weight-bearing joint. Loose bodies may develop, which may then cause joint destruction and/or locking. The damage to the articular surface is most likely a precursor of ankle osteoarthritis. With the recent advances in diagnostic imaging, such as MRI, as well as the development of ankle arthroscopy, the identification and classification of these lesions has become much more precise. This allows more accurate staging and improves treatment recommendations. The assessment of a particular treatment is also improved. A variety of treatment alternatives are now available. These include arthroscopic procedures including debridement, retrograde drilling, and bone grafting. Compared to open treatment, arthroscopic procedures may be particularly advantageous in the treatment of small defects and stable OCD lesions. Until recently, however, favorable results have been less predictable for large or unstable osteochondral defects. We treat these more difficult lesions with a mosaic autogenous osteochondral transplantation. In our hands, this appears to provide an optimal treatment result. The present report evaluates the clinical outcome of 36 patients followed for two to seven years after a mosaicplasty autogenous osteochondral transplantation from a non or less weight bearing portion of the knee to the ipsilateral talus. Ankle function was measured by the Hannover scoring system and showed good to excellent results in 34 cases (94%) with no long term donor site morbidity. The encouraging clinical results are supplemented with radiographs and histology, which support the premise of lasting relief of symptoms and prevention of ankle arthrosis.

Adolescent↗

PubMed2001

Factor XIII of blood coagulation as a nuclear crosslinking enzyme.

Intracellular localization and distribution of Factor XIII subunit A (FXIIIA) was investigated in association with monocyte-macrophage differentiation in a long term culture of human monocytes by light- and electron microscopical as well as biochemical and immunobiochemical techniques. To allow the detection of FXIIIA in cells with well-preserved ultrustructure, immunosera against glutaraldehyde-derivatized recombinant FXIIIA were developed in rabbits, then characterized and used in this study. In the early phase of macrophage differentiation intranuclear accumulation of FXIIIA was detected as a transient phenomenon in cells of the 2nd day culture by optical sectioning with 0,7 microm steps in laser scanning confocal microscopy and immunoblotting technique. FXIIIA could be detected by immunoelectron microscopic postembedding staining over electrodense DNA-containing areas. Fluoresceinated monodansylcadaverine incorporation assay was used to demonstrate that FXIIIA is not only present in the nuclei, but also expresses its transglutaminase activity. Our finding of the nuclear accumulation of FXIIIA in differentiating human macrophages is also unique in that a blood clotting factor has, for the first time, been localized in nuclei and has been shown to be an intracellular crosslinking enzyme. The possible role of nuclear FXIIIA in association with cellular processes involving chromatin structure remodeling, such as cell death, cell differentiation or cellular proliferation requires further in-depth investigation.

Cell Culture Techniques↗

PubMed2000

Quantitative image analysis of hyaluronan expression in human tooth germs.

The expression of hyaluronan in human tooth germs was studied by using a biotinylated hyaluronan-binding complex and quantitative digital image analysis. At the cap stage, dental papilla exhibited a moderate staining, while intense reaction was observed in the apical portion of presecretory ameloblasts, stellate reticulum, and in dental basement membrane. When the enamel and dentine matrices started to develop, a strong hyaluronan reaction was evident in the young enamel and the apical portion of secretory ameloblasts. No hyaluronan could be detected in the secretory ameloblasts and enamel matrix of the early (9-wk-old) post-natal stage. It is concluded that hyaluronan may play a transitory role in the early phase of the development of the enamel matrix organization. A very weak signal was observed in the wall of dentin tubules, whereas the rest of the dentine matrix was not stained. The odontoblasts and the pulp were also moderately stained, and these reactions gradually decreased with age, suggesting that hyaluronan may also contribute to the development of dentine matrix and pulp.

Ameloblasts↗

PubMed2000

Type X collagen in human enamel development: a possible role in mineralization.

Although type X collagen is one of the key molecules in endochondral ossification, no data are available on whether it is present in dental structures when mineralization is proceeding. We therefore monitored the appearance of type X collagen in tooth germs of human samples ranging in gestational age from 17-week-old fetuses to 9-week-old newborn. Using immunohistochemistry, ELISA techniques, and Western blotting, we show that type X collagen is present in human tooth germ during enamel maturation. Intense immunohistochemical staining for collagen type X was observed in the enamel and in the apical parts of secretory ameloblast at the bell stage when the dentine and enamel matrix were already under formation. The odontoblasts, the dentine, and the pulp were not stained. In the early (9-week) postnatal stage, the staining for collagen type X in the enamel matrix was diminished, and only a very weak signal could be detected in the secretory ameloblasts. A positive reaction for collagen type X was also observed in ELISA assay of extracts obtained from human embryonic enamel and hypertrophic cartilage samples. The Western blot analysis of the enamel demonstrated that size of the molecule detected by MoAb X53 is characteristic of the type X collagen. This correlates well with our immunohistochemical findings. Based on these data, we propose that type X collagen is one of the candidate molecules present in the enamel matrix that might be involved in mineralization of the enamel.

Ameloblasts↗

PubMed2000

Primary structure of human matrilin-2, chromosome location of the MATN2 gene and conservation of an AT-AC intron in matrilin genes.

We isolated full-length cDNA clones for human matrilin-2, an oligomeric protein, which forms filamentous networks in the extracellular matrices of various tissues. The human matrilin-2 precursor is encoded by a 4.0-kb mRNA, it consists of 956 amino acids and shows 93% similarity to the mouse protein. Out of the two von Willebrand factor type A-like domains, the 10 epidermal growth factor-type modules, one unique sequence and the oligomerization module, the first A domain is the most conserved. RT-PCR demonstrated wide expression of the gene in human cell lines of fibroblastic or epithelial origin. Alternative splicing affected only 19 amino acids in a 75-moiety-long segment, unique to matrilin-2. Isolation and analysis of the 3' end of the gene revealed that the reason for alternative splicing is alternative 3' splice site selection. Further, we identified in the human matrilin-2 gene a U12 type AT-AC intron between the last two exons encoding the oligomerization domain. We mapped the matrilin-2 gene (MATN2) by fluorescence in situ hybridization at chromosome position 8q22.

Alternative Splicing↗

PubMed2000

Serious fireworks-related eye injuries.

OBJECTIVE: To analyze and compare epidemiological and clinical information on serious fireworks-related eye injuries from two affiliates of the United States Eye Injury Registry. METHOD: Retrospective review. RESULTS: In the Eye Injury Registry of Alabama (EIRA) database, 185 of the 4150 injuries (4.4%) were caused by fireworks. In the Hungarian Eye Injury Registry database, only two of the 1245 cases (0.1%, p=0.000001) were fireworks-related. In the EIRA, 79% of patients were males and 87% were under 31 years. A bystander was injured in 67% of the cases, being an average of 23 feet away; 39% of bystanders had a final vision < or =19/200. No injured person wore eye protection. Bottle rockets caused 80% of the 185 injuries. Overall, 20% of eyes had <5/200 final visual acuity. Twenty-five percent of bottle rocket-injured eyes, compared to 64% of those injured by other devices, had > or =20/40 final vision (p=0. 000004). CONCLUSIONS. The rate of fireworks-related serious eye injuries has not decreased in Alabama in the last 16 years; most patients are young males. Since bystanders are at a measurable risk even at a distance of 100 feet, wearing eye protection is recommended to both bystanders and operators. Bottle rockets cause most of the injuries and the more severe ones, and should be the prime target for prevention. The benefit of a strict and enforced legislative ban on private fireworks displays is demonstrated by the much lower incidence figure in Hungary. Such a ban should be considered in other countries where fireworks-related eye injuries are common.

Adolescent↗

PubMed1999

Osteochondral mosaicplasty for the treatment of focal chondral and osteochondral lesions of the knee and talus in the athlete. Rationale, indications, techniques, and results.

New techniques for articular cartilage transplantation have become available recently for traumatic chondral injuries. Applications to the athlete have generated considerable interest in the sports medicine community. The autogenous osteochondral grafting mosaicplasty has been used to treat these injuries in the athlete population for the past six years. The rationale, indications, operative technique, results, and limitations of mosaicplasty in the athlete are presented and discussed.

Adolescent↗