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Biomedical subjects

A Fazekas

Publications and source records attributed to A Fazekas.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Adsorption of human serum proteins to titanium dioxide].

In order to find an in vitro biochemical model for investigation of osseointegration in terms of dental implantology, the aim of the present study was to analyse the adsorption of human serum proteins to titanium dioxide. Titanium dioxide powder was suspended in human serum. After incubation and centrifugation the TiO2 with the adsorbed proteins were washed with distilled water, ethylendiaminetetraacetic acid (EDTA) supplemented with ammonium hydrogencarbonate (NH4HCO3) solution, and sodium dodecylsulphate (SDS), after centrifugation the supernatant fluid was collected and SDS polyacrylamide gel and native (Biomidi) gel electrophoresis were conducted to determine the type of the adsorbed proteins. Our results show, that albumin was adsorbed to TiO2, but it could be easily removed. The adsorption of a 94 kDa protein was much stronger than the other proteins. The method seems to be useful in the investigation of the protein adsorbing ability of differently treated titanium implant surfaces.

Adsorption↗
PubMed1999

[Paraneoplastic nephropathy associated with adult renal carcinoma (immunologic and clinicopathologic study)].

Rare "paraneoplastic nephropathies" are associated with a wide variety of human tumors. Little is known about the pathogenetical background. To our knowledge no systematic study about the association of potentially "immunogenic" renal cell cancer (RCC) and "paraneoplastic nephropathy" has been published so far. An immunohistochemical analysis of native kidneys and a nephrological follow up of 60 patients with renal cell cancer (RCC) treated at the Department of Urology, medical University, Pécs (Hungary) between 1993-1998 has been performed. Cellular and humoral immunity was analysed by immunohistochemistry. Clinical/laboratory parameters of the patients with tumor associated nephropathy were pre- and postoperatively registered. Eleven IgA-nephropathy (IgA-NP) and 5 focal segmental glomerulosclerosis (FSGS), manifested in preoperative clinical signs in 11 out of 16 cases were found. Clinical symptoms disappeared in 6 out of 8 IgA-NP patients by tumor nephrectomy in a follow up of 38.7 (18-51) months. Eleven out of 16 tumors were stained with the identical anti human immunoglobulin (IgA or IgM) present in the glomerular immune complexes. The RCC-associated VHL (von Hippel-Lindau) protein was detectable in 3 out of 8 IgA-NP patients as an antigen component of their nephritogenic immune complexes. Tumor infiltrating lymphocytes (TIL) considered as a local sign of cellular tumor immunity were more frequently present in tumors associated with nephropathy than without it (69% vs 25%). Pathogenetic correlation between the tumor immunity in renal cell carcinoma and "paraneoplastic IgA-nephropathy" has been demonstrated in some of the cases. Tumor nephrectomy excluding the need of post-operative single kidney biopsies should be a safe tool in the differential diagnosis of tumor-associated nephrological conditions.

Adenocarcinoma, Clear Cell↗
PubMed1999

Renal cell carcinoma and paraneoplastic IgA nephropathy.

Paraneoplastic nephropathy is rarely associated with human tumors. Little is known about the pathogenetic background of this relationship. To our knowledge, no conclusive study of the association of potentially 'immunogenic' renal cell carcinoma (RCC) and paraneoplastic nephropathy has been published. For this reason, we performed an immunohistochemical analysis of native resected kidneys of 60 patients with RCC, paying special attention to their pre- and postoperative records. Sixteen (27%) of the 60 tumor patients had immune complex nephropathy (11 IgA nephropathy [IgA NP] and 5 focal segmental glomerulosclerosis [FSGS]). Preoperative proteinuria and/or hematuria observed in 11 of 16 cases disappeared in 6 IgA NP patients within a 2- to 3-month follow-up after nephrectomy. Eleven of 16 tumors stained with the anti human immunoglobulin (IgA or IgM) of the same isotype as that present in glomerular immune complexes. In 3 IgA NP patients RCC-associated von Hippel-Lindau (VHL) protein and IgA staining were found simultaneously in the tumor and glomeruli, with the clinical and laboratory findings disappearing after nephrectomy. Immune injury of the glomeruli due to a tumor-induced antigen-antibody response was demonstrated in these 3 IgA NP patients.

Adult↗
PubMed1999

[Function of the central sterilization office at the Semmelweis Clinic of Conservative Dentistry and Prosthodontics].

In order to prevent cross-infection by blood borne and other pathogens central sterilization department has been constructed in the common building of the Depts. of Conservative Dentistry and Prosthodontics. Instrument sterilization is accomplished in six steps: (1) consolidation and transport of instruments, (2) cleaning, (3) packaging, (4) sterilization, (5) storage, (6) sterilizer monitoring. This process is performed by trained sterilization technicians to ensure that attending faculty, student dentists, clinical staff and patients are protected from cross-infection caused by contaminated dental instruments.

Cross Infection↗
PubMed1999

Blood flow of the right and left submandibular gland during unilateral carotid artery occlusion in rat: role of nitric oxide.

UNLABELLED: The aim of the present study was to investigate the effect of unilateral carotid artery occlusion on the blood flow of submandibular gland in anesthetized rats and identify the role of nitric oxide (NO) in blood flow changes after the artery occlusion. L-NAME (N omega-nitro-L-arginine-methyl-ester; 10 mg/kg/day, per os) dissolved in tap water was used to block nitric oxide synthase. Glandular blood flow was measured using Sapirstein's indicator (86Rb) distribution technique. In the control animals the blood flow of left (ligated side) submandibular gland was lower than in the right (unligated side) one (right: 76.4+/-15.4 ml/min/100 g, 64.1+/-13.4 ml/min/100 g, p<0.01). The blood flow of submandibular glands decreased in NOS blocked group versus control. The vascular resistance after L-NAME treatment was elevated (control: 11+/-2.3 R/kg, L-NAME: 17.5+/-4.1 R/kg, p<0.001). In L-NAME group the difference between blood flow value of the left and right submandibular gland was significantly lower than in the control group (control: -16%, NAME: -8%, p<0.01). CONCLUSION: The maintenance of the blood flow in the left submandibular gland during ligation of the left common carotid artery could be due to the good vascular anastomotic system at these regions and adaptation of the submandibular vessels to the decreased perfusion pressure. Nitric oxide may have a role in the regulation of blood flow tinder this condition.

Animals↗
PubMed1999

A ten-year clinical follow-up study of prosthetic rehabilitation of the edentulous lower jaw with endosteal dental implants.

This paper reports on 10 years of clinical experience with implant prosthodontic treatment of total edentulism. During this period, of the 735 implants that were inserted, only 19 were lost, a 97.4% success rate. The authors believe that evaluating the success of implant treatment requires examining the health of the peripilastrium with periodontologic methods. The indices the authors used for such an evaluation were plaque accumulation, crevicular fluid flow rate, and sulcus bleeding; crevicular fluid flow proved the most satisfactory for estimating the health of peri-implant tissues. The results demonstrate that peri-implant-tissue health is similar to that of the tissues surrounding nontreated natural teeth and better than that of the tissues surrounding natural teeth wearing crowns.

Adult↗
PubMed1999

Implant-prosthetic rehabilitation after segmental mandibulectomy and bone grafting.

A free vascularized fibula (6 cases) and iliac bone (11 cases) graft were used to reconstruct a mandibular discontinuity defect resulting from cancer surgery in 17 patients. Fifty-two osseointegrated DenTi implants were secondarily placed into the grafted bone, and all the patients underwent prosthetic rehabilitation. (DenTi is an endosseous dental implant system invented and manufactured by Denti-System Ltd., Szentes, Hungary.) To date, the maximum follow-up time after prosthetic treatment is 5 years, the minimum is 2 years. During this time, only one of the 52 inserted implants was lost, and that occurred a few days after insertion. Clinical signs of peri-implantitis were observed in only 2 of the fixed prosthetic restorations. Long-term maintenance is essential if such patients are to achieve successful prosthetic restorations and, thus, enhanced lives.

Bone Transplantation↗
PubMed1998

Blood flow of the submandibular gland in sodium-depleted and -loaded rats: effect of nitric oxide synthase inhibition.

The present investigations were designed to study the hemodynamic effects of different sodium diets in the submandibular gland of rats with or without nitric oxide (NO) synthesis inhibition. Experimental animals were kept on: (1) standard chow and tap water ad libitum (normal group, N), or (2) wheat and distilled water ad libitum for 4 weeks (sodium-depleted animals, SD), or (3) standard chow and saline ad libitum for 4 weeks (sodium-loaded animals, SL). NO synthase was inhibited by N omega-nitro-L-arginine-methyl-ester (L-NAME, 10 mg/kg per day) in the last week. The rats were anesthetized, and blood pressure, cardiac output (Stewart-Hamilton's principle) and blood flow (BF) of the submandibular gland (Sapirstein's technique) were determined. High sodium intake resulted in a 47% increase of glandular BF as compared to BF measured in the control group. In all groups L-NAME decreased BF (ml/min per 100 g gland) as compared to those of rats with no L-NAME treatment (N: 76.4 +/- 15.4 vs. 56.0 +/- 11.6, P < 0.05; SD: 71.0 +/- 17.7 vs. 56.2 +/- 15.1, n.s.; SL: 112 +/- 29.4 vs. 66.9 +/- 18.4, P < 0.001), whereas the vascular resistance (VR, mm Hg x ml-1 x s x kg-1) increased (N: 11.0 +/- 2.3 vs. 17.5 +/- 4.1, P < 0.001; SD: 11.0 +/- 2.7 vs. 17.0 +/- 4.2, P < 0.01; SL: 8.5 +/- 2.4 vs. 14.9 +/- 4.6, P < 0.001). The increase in VR after L-NAME treatment was 64% in normal, 55% in sodium-depleted and 75% in sodium-loaded rats. Our results suggest that NO takes part in the regulation of vascular resistance and BF in the submandibular gland. Sodium load itself increases BF of the submandibular gland and this phenomenon may partly be mediated by NO.

Animals↗
PubMed1998

Protective effects of mercaptoethylguanidine, a selective inhibitor of inducible nitric oxide synthase, in ligature-induced periodontitis in the rat.

1. Excessive production of nitric oxide (NO), and the generation of peroxynitrite have been implicated in various proinflammatory conditions. In the present study, using mercaptoethylguanidine (MEG), a selective inhibitor of iNOS and a peroxynitrite scavenger, we investigated the role of iNOS and peroxynitrite in a rat model of periodontitis. 2. Periodontitis was produced in rat by a ligature of 2/0 braided silk placed around the cervix of the lower left 1st molar. Animals were then divided into two groups: one group of rats was treated with MEG (30 mg kg(-1), i.p., 4 times per day for 8 days), animals in the other group received vehicle. At day 8, the gingivomucosal tissue encircling the mandibular 1st molars was removed on both sides from ligated and sham operated animals for inducible nitric oxide synthase (iNOS) activity assay and for immunocytochemistry with anti-iNOS serum. Plasma extravasation was measured with the Evans blue technique. Alveolar bone loss was measured with a videomicroscopy. 3. Ligation caused a significant, more than 3 fold increase in the gingival iNOS activity, whereas it did not affect iNOS activity on the contralateral side, when compared to sham-operated animals. Immunohistochemical analysis revealed iNOS-positive macrophages, lymphocytes and PMNs in the connective tissue and immunoreactive layers of epithelium on side of the ligature, and only a few iNOS reactive connective tissue cells on the contralateral side [corrected]. Ligation significantly increased Evans blue extravasation in gingivomucosal tissue and alveolar bone destruction compared to the contralateral side. MEG treatment significantly reduced the plasma extravasation and bone destruction. 4. The present results demonstrated that ligature-induced periodontitis increases local NO production and that MEG treatment protects against the associated extravasation and bone destruction. Based on the present data, we propose that enhanced formation of NO and peroxynitrite plays a significant role in the pathogenesis of periodontitis.

Animals↗
PubMed1998

[Restoration of root canal treated teeth using carbon fiber posts].

The restoration of root canal treated teeth--because of the significant loss of tooth structure--is often achieved with post and core. However, post may generate stresses which lead to vertical root fracture and loss of the tooth. Since post design, material used and the post space preparation has significant influence on vertical fracture prevalence, broad investigation is in progress to find out the optimum procedure. During the last decade new prefabricated passive posts were introduced for postendodontic restorations. In order to collect information clinical trials have been performed on the reconstruction of root canal treated teeth using carbon fibe posts (COMPOSIPOST, RTD, France; C-POST, Bisco, USA). Adhesive technique was applied to cement posts in the root canal and for composite core reconstruction. The physical properties of carbon fiber posts and the composite core are very close to those of dentin. Post application is simple, does not require special skill and for the patients means minimum hazard. The position of the posts was controlled by radiography. During the 24 months observation period no failure was registered in patients treated (n = 55). Hence, we attribute our good results to the homogeneous reconstruction of the teeth. This procedure seems to be a good alternative to traditional cast metal dowel/cores or metal prefabricated posts.

Anti-Infective Agents, Local↗
PubMed1998

[Clinical study of tooth-to-implant supported fixed partial dentures].

The lack of the periodontal ligaments around the implants results an ankylotic fixation. The mobility of the osseointegrated implants is only one tenth of the mobility of the natural teeth. To connect a natural tooth and an implant as abutments in a fixed restoration is a special problem in the dentistry. The aim of this study was to examine whether connecting of implants and natural teeth has any disadvantages for the abutment either implant or natural tooth. Furthermore we wanted to know if an overloading of the opposing tooth could occur because of the stiffness of the implant-bone connection. 21 partially edentulous patients, who were treated with implant supported bridges using the DenTi implant system which includes screw-shaped, commercially pure titanium implants, were examined. Plaque, calculus, gingival index, probing depth and bleeding on probing were recorded around the implants and the teeth. Mobility, sound on percussion were examined as well. In this study no disadvantageous effect of connecting teeth to implants as abutments by fixed partial dentures was found. There was no sign of a harmful effect of the implant to the opposing teeth either. The tooth-to-implant bridges function in their biological environment without affecting it adversely.

Adult↗
PubMed1997

[Analytic evaluation of Clorox household bleach from the viewpoint of its value in the use in endodontics].

The purpose of this study was to determine the impurities and the concentrations of the main components (e. g. the total chlorine, the sodium hypochlorite, the sodium chloride, the sodium hydroxide, the sodium chlorate, the sodium content) of Clorox house-hold bleach available in Hungary. We also determined the available chlorine of clorox sample. Our examinations showed that the concentrations of impurities examined are far from those affecting adversely the human health.

Chlorine↗
PubMed1997

[Recommendation of the introduction of salt fluoridation for caries prevention in Hungary].

The aim of the paper is to review the four decades' long history of salt fluoridation, and to report on experiments and activities in Hungary in the course of the last three decades, aiming the country-wide introduction of domestic salt fluoridation. Salt fluoridation, as a caries preventive method was first introduced in Switzerland, in 1955, later caries-reducing effects were studied in Columbia, Spain and Hungary. The results of the clinical experiments of K. Tóth performed in Szeged, Hungary, showed after 17 years a caries reduction of about 66%. These results contributed significantly to the introduction of salt fluoridation in several (France, Costa Rica, Jamaica, Germany) countries. Leaders of Hungarian dentistry tried to introduce salt fluoridation since 1972, but due to the antifluoride lobby, and organisational difficulties, the authorization was delayed. However, in the last three years in the course of several discussions and debates within the top-commissions, a positive statement was issued recently by the Hungarian Academy of Sciences on the support for the country-wide introduction of domestic salt fluoridation at earliest possible convenience.

Adolescent↗
PubMed1996

[Does tonsillectomy cause any change in long-term course of IgA nephropathy?].

Tonsillectomy seems to be a logical step in IgA nephropathy owing to the frequent tonsillitis before the beginning and the acute exacerbations of the disease. The usefulness of tonsillectomy is questionable because there are only few and short-term follow-up data after it. We followed up 35 kidney biopsy proven IgA nephropathy patients (25 men and 10 women) for an average of 12.2 yrs (range 7-32) after tonsillectomy. The values of endogenous creatinine clearance, serum creatinine, hematuria and proteinuria were compared at regular intervals during a follow-up with those obtained before tonsillectomy. We considered more than 12,000 data using 2 tailed t test. We found that proteinuria started to decrease significantly already 6 months after tonsillectomy (1.40 +/- 0.27 g/day before tonsillectomy vs 0.92 +/- 0.25 g/day after it, p < 0.05) and was significantly lower under follow-up. The tendency in microhematuria was similar (70.5 +/- 35.0 million RBC/12 hours before and 14.0 +/- 6.5 million RBC/12 hours 6 months after tonsillectomy, p < 0.0001). Furthermore, tonsillectomy stopped gross hematuria appearing in the acute exacerbation of the disease in more than two-thirds of patients. Creatinine clearance did not change in the first 2 years after tonsillectomy, however, from 2.5 years after it is significant slow and continual decrease started (117.0 +/- 9.8 ml/min before and 106.2 +/- 10.8 mil/min 2.5 yrs after tonsillectomy, p < 0.05). End-stage renal failure was detected only in 4 patients out of 35 after 10 years after tonsillectomy, in our non-tonsillectomised control group in 8 patients out of 40.

Adolescent↗
PubMed1996

Effects of streptozotocin-induced diabetes on neurogenic inflammation of gingivomucosal tissue in rat.

It has been suggested that the unmyelinated small diameter afferent nociceptive C-fibres are impaired in diabetes mellitus. We have recently demonstrated that these fibres are the prerequisite for neurogenic inflammation induced by mechanical or chemical irritations. These experiments were designed to characterize the neurogenic inflammatory responses of gingivomucosal tissue in the early phase of experimental induced diabetes mellitus in rat. Effect of dental ligature on the gingivomucosal (GM) vascular permeability was studied in control rats and in rats pretreated with streptozotocin at d 7 and 14 following streptozotocin administration. In separate groups of control and streptozotocin diabetic rats studies were also performed to investigate the effect of local capsaicin application on GM vascular permeability on d 14. Vascular permeability was assessed by means of Evans blue extravasation. The ligature placed around the mandibular left first molar caused a significant increase vascular permeability of GM tissue on the ipsilateral side on both d 7 and 14 after the ligation in control rats. In streptozotocin diabetic rats on d 7, there was also a significant elevation of Evans blue extravasation in the tissue tested on the ligature side. However, on d 14 the ligation failed to produce any changes in Evans blue extravasation on the ipsilateral side, i.e. no difference in GM vascular permeability could be recorded between the two sides in streptozotocin diabetic rats. Topical capsaicin administration produced significant Evans blue extravasation in GM tissue of control rats compared to that observed in diabetic rats on d 14 after streptozotocin treatment. Electron microscopic and light microscopic studies demonstrated fibre degeneration of the C neurones and less inflammatory cells in streptozotocin-induced diabetes in the gingivomucosal tissue. These findings appear to indicate that the inflammatory responses induced by mechanical (dental ligature) and/or chemical irritants (topical application of capsaicin) in the gingivomucosal tissue are altered in streptozotocin diabetic rats and this alteration is due to the diabetes-induced damage to the unmyelinated C fibres.

Administration, Topical↗
PubMed1995

Effect of substance P administration on vascular permeability in the rat oral mucosa and sublingual gland.

Neuropeptides, including substance P (SP) may play a role in neurogenic inflammation. Although SP-immunoreactive (SP-IR) axons are known to be present within the oral mucosa (OM) and salivary glands, the functional significance of SP in oral mucosa and sublingual salivary gland (SLG) is not fully understood. The present experiments were carried out to study the effects of SP infused into the left common carotid artery on vascular permeability in the OM and in the SLG of male rats. Vascular permeability was assessed on the basis of Evans Blue extravasation. Separate groups of animals received histamine (H1) receptor antagonist (chloropyramine, 10 mg kg-1 i.v.) or prostaglandin synthesis inhibitor (indomethacin, 4 mg kg-1 i.v.) prior to SP infusions. Infusion of SP in doses of 30 and 74 pmol min-1 increased the vascular permeability of OM by 162.3 +/- 16.3% (n = 8, p < 0.05) and 482.7 +/- 46.7% (n = 8, p < 0.001), respectively. SP in a dose of 15 pmol min-1 did not increase Evans Blue extravasation in OM (38.3 +/- 4.0 micrograms g-1, n = 8, compared to the control: 44.0 +/- 7.9 micrograms g-1, n = 8, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1995

[Effect of preventive fluoride treatment in childhood on dental conditions in adults].

The purpose of the study was to compare the dental health status of three groups of adults aged 18-47. In the first group belonged the population, that consumed in their childhood salt containing 250-350 mg fluoride per kg. The second group consisted of those who drank water with an optimal fluoride concentration (1 mg/kg). The individuals without fluoride prevention formed the third group. The results showed, that the consumption of fluoridated drinking water or salt in childhood has a life-long beneficial effect on the dental health of the adult population.

Adolescent↗