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Biomedical subjects

K Nagy

Publications and source records attributed to K Nagy.

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

On the useful role of OH&z.rad; free radicals in differentiation of cultured human fibroblasts.

The working hypothesis assuming that oxygen free radicals cannot be considered only as harmful by-products of the oxidative metabolism has been experimentally tested. Human fibroblasts were grown in culture from the following five types of tissues: (1) normal orbital fat; (2) orbital fat of patients with endocrine ophtalmopathy (EOP); (3) normal orbital muscle; (4) orbital muscle of EOP patients; (5) skin. These fibroblasts (second to 12th passages) were treated for 2x72 h with the Fenton reactants: ADP-Fe(2+)-complex (0.1 mM for iron) and H(2)O(2) (0.055 mM), final concentrations. This treatment caused a slowing down of the cell proliferation, induced various morphological signs of differentiation, and significantly increased (40-150%) the total superoxide dismutase (SOD) and catalase (CAT) activities of the fibroblasts. Authors suggest that the increased expression of these enzymes may play a general role in the cell differentiation mechanisms, meaning that the generation of oxygen free radicals is an essential, useful factor even during the early phases of development, and may not be taken only as a harmful process during aging.

Journal Article↗
PubMed2000

Inhibition of microflora associated with oral malignancy.

Changes in the microflora on oral carcinoma surfaces may lead to both local and systemic infections, which may complicate the morbidity of the patient suffering from oral malignant neoplasms. Thus, anticancer therapy, irradiation, chemotherapy or surgery impairs the defence mechanism of the oral mucosa and is accompanied by proliferation of the mucosal biofilm with overgrowth of yeast and bacteria. This study investigates the inhibition of the biofilm present on the surface of oral squamous cell carcinomas. Biofilm samples were obtained from the central surface (1 cm2) of each lesion in 10 patients (eight male, two female; mean age: 47.6 years; SD +/- 7.6) before any antibiotherapy or tumour treatment. Patients were randomly divided into two groups and were rinsed with Meridol mouthrinse (amine fluoride) or placebo (saline solution) for 7 days. Samples were repeatedly taken from the same site after rinsing. Samples were transported in pre-reduced brain heart infusion broth and cultured within 1 h of removal, using aerobic and anaerobic complete and selective media. Total aerobic and anaerobic counts were determined and isolated bacteria were identified. The median counts of colony forming units (CFU/ml) after rinsing with Meridol were significantly lower for both aerobes and anaerobes than before rinsing with Meridol. (For aerobes before rinsing: 1.35 x 10(6), after rinsing: 7.55 x 10(5); p = 0.025; for anaerobes before rinsing: 1.39 x 10(6), after rinsing: 7.15 x 10(5); p = 0.011. Rinsing with placebo: no significant difference was found. Aerobe median counts before rinsing: 1.17 x 10(6), after rinsing: 1.03 x 10(5), and for anaerobes: before rinsing 1.75 x 10(6), after rinsing: 1.51 x 10(6); p > 0.05 [Wilcoxon test].) It was concluded that 7-days (three times a day) Meridol rinsing significantly reduced the surface biofilm of oral carcinoma compared to rinsing with placebo. Clinical examination indicated no irritation of the mucosa. The mouthrinse was well tolerated by the patients, who commented on a reduction in burning sensation and bad breath. Besides routine oral hygiene, rinsing itself could reduce patient morbidity. The findings of the present study indicate that in addition to any other oral focus, the lesion itself, when ulcerated, should receive direct antimicrobial treatment so as to reduce patient morbidity and enhance quality of life.

Adult↗
PubMed2000

Hyperthermic resuscitation is safe and effective after hemorrhagic shock in dogs.

OBJECTIVE: To show that resuscitation from hypothermic, hemorrhagic shock using 65 degrees C intravenous fluid results in a more rapid return to euthermia compared with 40 degrees C intravenous fluid, without significant endothelial or hemolytic injury. DESIGN: Fourteen anesthetized beagles (10-12 kg) were cooled to a core temperature of 30 degrees C and hemorrhaged to a mean arterial pressure of 40 to 45 mm Hg for 30 minutes. The animals were randomized to receive either 65 degrees C or 40 degrees C intravenous fluid through a specially designed catheter at a rate of 80% of their blood volume per hour until euthermic (37 degrees C) or for 2 hours. MATERIALS AND METHODS: Blood pressure, pulmonary artery pressure, heart rate, and core temperature were continuously monitored. Blood samples were collected at baseline, after hemorrhage, 2 hours of resuscitation, and at postmortem examination after 7 days of survival. Laboratory measurements included complete blood count, plasma-free hemoglobin, and osmotic fragility. Values were compared using the Student's paired or unpaired t test with p approximately 0.05 indicating significance. Postmortem examination included light microscopy of the proximal superior vena cava or right atrium. RESULTS: Animals receiving 65 degrees C intravenous fluid warmed 3.6 degrees C/hour, significantly faster than the 40 degrees C animals (1.9 degrees C/hour). There were no significant differences in plasma-free hemoglobin or osmotic fragility. Endothelial injuries were found in two animals in each group. These defects occurred along the path of catheter insertion and not at the infusion site. CONCLUSIONS: Central intravenous fluid at 65 degrees C is a more rapid means of treating hypothermia than standard 40 degrees C intravenous fluid. It is safe even in hypovolemic animals.

Animals↗
PubMed2000

Guidelines for the diagnosis and management of blunt aortic injury: an EAST Practice Management Guidelines Work Group.

In summary, BAI is a lethal result of severe blunt trauma. It should be considered in all patients who sustained injury by a deceleration or acceleration mechanism, especially in the face of physical or radiographic findings suggestive of mediastinal injury. Angiography remains the "gold standard" for diagnosis, although CT scanning is taking more of a role, especially for screening. Diagnosis should be followed by prompt surgical repair using some method of distal perfusion to minimize renal and spinal cord ischemia. If prompt repair is not feasible because of other injuries or comorbidities, medical control of blood pressure is warranted in the interim.

Angiography↗
PubMed2000

Diagnostic sensitivity of three tumour markers in non-small cell lung cancer: a pilot study.

BACKGROUND: Three tumour markers (CEA, CYFRA 21.1 and CA125) were evaluated for diagnostic sensitivity in newly diagnosed, untreated non-small cell lung cancer. METHODS: In the 24 patients studied, the tumours were classified histologically as 15 squamous cell carcinomas and 9 adenocarcinomas. In 19 cases, the disease was confined to the lung (M0); 5 cases presented with metastatic disease at the time of diagnosis (M1). RESULTS: CA125 displayed the best overall sensitivity (62%) and also when only localised disease was evaluated (63%). CA125 was the most sensitive marker for adenocarcinomas (89%), with values differing significantly with histological type (p < 0.005). CYFRA 21.1 was most sensitive in squamous cell carcinomas (53%); this was the only marker which was elevated in all cases involving metastatic disease, and exhibited a significant correlation with stage (p<0.02). CEA presented the poorest overall sensitivity (42%). The overall sensitivity of the three-tumour marker association was 79% and the best combination of two markers was CYFRA 21.1 + CA125 (75%). CONCLUSIONS: This pilot study allows recommendation of the associated use of these two markers as first choice of diagnostic aid in non-small cell lung cancer. Further measurements, including specificity studies in benign lung diseases, should be performed to confirm these results.

Journal Article↗
PubMed1999

The hydroxyl free radical reactions of ascorbyl palmitate as measured in various in vitro models.

The OH(*) free radical scavenging properties of ascorbyl palmitate (AP), water-solubilized in the presence of a surfactant (Brij 35), were tested in various systems: (1) The inhibition of polymerization of bovine serum albumin by OH(*) free radicals generated by the Fenton reaction indicated AP exerts a considerable protective effect against polymerization by scavenging the OH(*) free radicals. (2) ESR spin trapping comparisons of DMPO with AP were conducted. Using the Fenton reaction as a source of OH(*) free radicals, AP was 1 order of magnitude faster in scavenging these radicals than DMPO. (3) Oxidative modification of BSA by (60)Co-gamma irradiation of 80 krad, results in a strong increase in protein carbonyl content. AP inhibits carbonyl formation very efficiently, indicating that AP may be utilized as a biological OH(*) free radical scavenger in human therapy.

Animals↗
PubMed1999

[Level of HHV-6A antibodies in symptomless HIV infection as well as in the course of AIDS].

HHV-6A in vitro augments expression of CD4 molecules on the surface of immune cells, facilitates HIV replication and cell death in dual infections. It is hardly known whether these processes take place in vivo; does HHV-6A enhance HIV infection and AIDS progression? To study HHV-6A fresh infections and reactivation, IgM, IgG and low avidity IgG were quantitated in the serum samples of patients with asymptomatic HIV infection, early and terminal AIDS, that of their HIV seronegative homo- or bisexual partners and healthy adults (altogether 65 persons). Indirect immunofluorescent assay on JJHAN cells infected with HHV-6A U1102 was used. It was found that as compared to controls, the mean level of IgM in the sexual partners of HIV infected subjects raised 30-fold, that of IgG increased 10-fold, and 80% of persons had low avidity IgG indicating fresh HHV-6A infection. These suggest that they are frequently infected through sexual intercourse. As compared to healthy adults, mean titre of IgM to HHV-6A remained 10-fold increased in each group of patients with HIV infection. The IgG level was 6-fold increased in asymptomatic HIV infected subjects, 4-fold in early and 5-fold in terminal AIDS patients. More than one quarter of AIDS patients had low avidity IgG to HHV-6A. As compared to slow progressors of AIDS, the IgG level continuously increased in progressor persons. These suggest that HHV-6A maintains a chronic persistent infection in a significant number of HIV infected subjects.

Acquired Immunodeficiency Syndrome↗
PubMed1999

C1q autoantibodies in HIV infection: correlation to elevated levels of autoantibodies against 60-kDa heat-shock proteins.

Antibodies to solid phase C1q (C1qAb) were determined in 295 serum samples from 132 HIV-infected subjects and in sera from 140 HIV-seronegative healthy individuals as control. An ELISA method applied for the determination of C1qAb in other diseases was used. In part of these sera, other autoantibodies (antibodies reacting with 60-kDa human heat shock protein (hsp60) or mycobacterial hsp65; IgA and IgG class antibodies against the Fab and F(ab')2 moieties of IgG) as well as complement-mediated antibody-dependent enhancement/neutralization (C'-ADE) were also determined. Increased amount of C1qAb was found in HIV-infected subjects as compared with HIV-seronegative controls (P = 0.0138). In 17 of 132 (13.0%) seropositive individuals but only in 7/140 (5.0%) samples from the controls, the amount of C1qAb exceeded the upper limit (95th percentile) of the normal values (P = 0.031). The amount of C1qAb significantly decreased during a follow-up period of 65 months. C1qAb levels were found to strongly correlate to hsp60/65 autoantibodies but did not correlate or only weakly correlated to the amount of anti-Fab or anti-F(ab')2 autoantibodies measured in the same serum samples. Anti-C1q antibodies recognized the solid phase hsp60/65. Three predicted epitope regions of M. paratuberculosis hsp65 were able to bind efficiently C1q antibodies. An inverse correlation was found between C1qAb and C'-ADE, neutralization was more frequent in the sera with detectable C1qAb, whereas sera without C1qAb more likely enhanced HIV infection in vitro.

Antigens, Bacterial↗
PubMed1999

Antibodies against human heat-shock protein (hsp) 60 and mycobacterial hsp65 differ in their antigen specificity and complement-activating ability.

Although complement activation appears to have an important role both in the early and late phases of atherosclerosis, the exact mechanism of the initiation of this activation is still unknown. Since injuries of the endothelial cells are known to result in increased stress-protein expression we tested the complement-activating ability of recombinant human 60 kDa heat-shock protein (hsp60). Human hsp60 was found to activate the complement system in normal human serum in a dose-dependent manner. Activation took place through the classical pathway. The lack of complement activation in agammaglobulinemic serum indicates that the classical pathway is triggered by anti-hsp60 antibodies. Hsp60 activated complement in the sera of 74 patients with coronary heart disease as well, and a strong positive correlation (r = 0.459, P < 0.0001) was found between the extent of complement activation and the level of anti-hsp60 IgG antibodies but there was no correlation to the level of anti-hsp65 IgG antibodies. Further distinction between anti-hsp60 and anti-hsp65 antibodies was obtained from competitive ELISA experiments: binding of anti-hsp60 antibodies to hsp60-coated plates was inhibited only by recombinant hsp60 and vice versa. Our present findings indicate that anti-hsp60 and anti-hsp65 antibodies are distinct, showing only partial cross-reactivity. Since complement activation plays an important role in the development of atherosclerosis and the levels of complement-activating anti-hsp60 antibodies are elevated in atherosclerosis-related diseases, our present findings may have important pathological implications.

Adult↗
PubMed1999

Evisceration after abdominal stab wounds: is laparotomy required?

OBJECTIVES: To determine the incidence of intra-abdominal injury requiring laparotomy after an abdominal stab wound with evisceration. To identify clinical signs that increase the likelihood of an intra-abdominal injury in the presence of such a wound. METHODS: Information was collected prospectively over an 8-year period on all patients who presented to our urban level I trauma center with an abdominal stab wound and evisceration. This information included which organ eviscerated, presence of other indications for laparotomy, organs injured, and postoperative complications. All comparisons used the Fisher's exact chi2. RESULTS: A total of 81 patients were admitted with evisceration after an abdominal stab wound. Sixty-one patients (75%) had eviscerated omentum, 18 patients (22%) had eviscerated small bowel, and 2 patients (2%) had eviscerated colon. Sixty-two patients (76%) had evisceration as the sole indication for laparotomy, the remaining 19 patients (24%) had another indication such as hypotension or peritonitis. Overall, 63 patients (78%) had an intra-abdominal injury that required repair. This was true regardless of organ eviscerated (omentum = 77% vs. viscus = 80%, not significant) or clinical presentation (no other indication = 76% vs. another indication = 84%, not significant). CONCLUSION: The majority of patients who present with an evisceration after a stab wound to the abdomen require a laparotomy. This is true regardless of what has eviscerated or the presence of other clinical indications to operate. Evisceration should continue to prompt operative intervention.

Abdominal Injuries↗
PubMed1999

A proposed consent process in studies that use an exception to informed consent.

Federal regulations allow an exception to informed consent when it is not feasible to obtain informed consent in certain emergency research circumstances. A multicenter, randomized, single-blinded, normal saline procedure-controlled efficacy trial of diaspirin cross-linked hemoglobin (DCLHb) in acute traumatic hemorrhagic shock was conducted. The study intended to include 850 of the most severely injured trauma patients with hemorrhage and persistent hypoperfusion as demonstrated by vital signs suggestive of vascular collapse or a base deficit that signified prolonged hypoperfusion. It was anticipated that some patients would be unable to provide informed consent, and that identification and availability of some patients' legally authorized representatives (LARs) would be unlikely within the therapeutic window of the intervention. Each participating institution therefore developed a process to implement exception to informed consent. Each hospital's proposed process was reviewed by the institutional review board, the sponsor, the FDA, and the study's data monitoring committee chair. The goal was the development of local implementation processes by which the best interests of patients and their families could be fulfilled using prospective informed consent, the exception to informed consent, and consent to continue in emergency research, as appropriate for each individual patient. This paper describes the proposed implementation method developed for Cook County Hospital. It includes several important features, 1) prospective informed consent by the patient, when feasible; 2) the ability of the patient to decline participation, even when deemed incompetent to provide prospective informed consent; 3) prospective consent by the family/LAR, when feasible; 4) the use of a scripted abbreviated consent by the patient family/ LAR in life-threatening situations when it is possible only to briefly discuss the research being conducted; 5) independent approval for the use of the consent exception by a second physician immediately prior to patient enrollment; 6) the repeated use of consent to continue (both for the family/LAR and by the patient) when an exception to consent has been utilized; and 7) ongoing review of the informed consent process on a case-by-case basis by the institution's scientific review committee. The authors believe this proposed informed consent process maximizes the communication between investigators, patients and their proxies, and the institution's scientific review committee. Multiple mechanisms exist that allow for consent to be provided or declined, both prior to and after enrollment in the research protocol. The ongoing immediate review of the process allows for process enhancements to be made as needed.

Aspirin↗
PubMed1999

[In vitro comparison of marginal adaptation of various filling materials. I. Effect of the filling material on marginal adaptation].

In a two-month in vitro experiment cervical marginal adaptation was examined in relation to the preparation, filling method and restorative material. Fifty Class II cavities were prepared in fifty extracted sound human premolar and molar teeth extending to the approximal cement-enamel junction. The cavities to receive composite restorations were bevelled at the vestibulo-occlusal and -approximal enamel margins, the other aspects of the cavity enamel and gingival margins at the cement-enamel junction being prepared conventionally. The cavities for amalgam were prepared and filled conventionally. The specimens were cycled in different buffer solutions and temperature, modelling possible variations in the oral environment and examined with SEM. The results were analysed using ANOVA. The best marginal adaptation among the composites was achieved with Charisma, Estilux Posterior, Durafil and Prisma AP. H at the bevelled enamel margins, the worst marginal fit was with Heliomolar and Polofil. It was concluded, that adhesive technique reduces, but does not eliminate marginal leakage.

Analysis of Variance↗
PubMed1999

[In vitro comparison of marginal adaptation of different filling materials. II. Effect of the site and method of preparation on the marginal adaptation].

In a two-month in vitro experiment we examined the marginal adaptation of ten dental materials. Fifty Class II restorations were prepared extending to the cemento-enamel junction. The cavities of the composite restorations were bevelled at the vestibulo-occlusal and -approximal enamel margins, on the other side enamel and gingival margins were prepared conventionally. The specimens were thermocycled and examined with SEM. The microleakage was measured at the vestibulo-occlusal and -approximal tooth-filling junction, where adhesive technique was used, and at the gingival, oroocclusal and -approximal margins, which were not bevelled before. The obviously most important conclusion of the study is, that in the case of deep Class II cavities the amalgam has a better adaptation at the gingival margin than the examined composite resins.

Dental Amalgam↗
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

[Endoscopic anatomy of the tympanic cavity].

Development of modern diagnostic procedure requires inframacroscopic description of tympanic cavity. This description has to suit the special requirements of diagnostic endoscopy, too. The authors made an attempt to describe clinical anatomy of the tympanic cavity. For endoscopic investigation transtympanic, transtubal and transmastoidal approaches were used, out of which the transmastoidal has the least clinical importance. Using the transtympanic approach, detailed anatomical description of the medial wall, the auditory ossicles and the stapedius muscle can be given. Using the transtubal approach, the epitympanic region, stapedius and tensor tympani muscle and two major nerves, chorda tympani and tympanic nerve can be also investigated. Using transmastoidal approach, auditory ossicles were seen, but it was possible to identify lateral part of epitympanic recess, as well.

Ear Diseases↗