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G Kovács

Publications and source records attributed to G Kovács.

At least 19 recordsLinked to original sources
PubMed2003

Metastatic tumors of the orbit: a retrospective study.

PURPOSE: To present the clinical features and facts on prognosis, therapy and diagnostics of orbital metastases treated in the Orbital Center Kiel. METHODS: We reviewed the records of 20 patients with orbital metastases (ca. 2% of all orbital patients seen in a 10-year period). RESULTS: The mean age at first manifestation of orbital symptoms was 64 years. On average, 64 months was the period of time between the onset of the primary disease and orbital manifestation. The sites of the primary tumors were breast (8), choroid (2), prostate (2), gastrointestinal tract (3), lung (2), urinary bladder (1), Schmincke tumor of the throat (1) and unknown origin (1). Eleven patients were female, 9 male. The main primary symptoms consisted of lid swelling (11), red eye (9), diplopia (10), and proptosis (7). Although the majority (16/20) were treated by chemotherapy, radiotherapy or surgery, 19 patients died after a mean survival time of 14.7 months. CONCLUSION: Orbital metastases remain an unfavorable prognostic factor, but the diagnosis and treatment are still important in order to prevent loss of vision and improve the patient's quality of life. As previous studies have shown, the overall survival rate is still as limited as nearly half a century ago.

Adult↗
PubMed2003

Effects of surface cues on macaque inferior temporal cortical responses.

Humans are able to recognize objects when surface details, such as colour, texture and luminance gradients, are not available. By systematically eliminating colour, texture, shading, contrast and inner contours from given objects, we tested whether certain shape-selective inferior temporal cortex (IT) neurons of awake rhesus monkeys remain selective for these objects as the surface information is reduced. In psychophysical experiments, we established that the rhesus monkey can identify the shape of a coloured object largely independently of its surface characteristics and, to a lesser degree, of its inner contours. Shape selectivity of the neurons does not change when texture and shading are concealed. The responsiveness of the neurons is also affected by the removal of these surface attributes. The IT neurons were found to respond highly similarly to objects brighter or darker than their background. Selectivity for shape is preserved when the contrast is reversed. Deletion of the inner contours, outlining the main parts of the objects, did not affect the responses and selectivity of the IT neurons. These findings indicate that the IT can contribute to the invariant perception of objects having different surface details.

Animals↗
PubMed2002

Effects of glucagon and insulin on plasma glucose, triglyceride, and triglyceride-rich lipoprotein concentrations in laying hens fed diets containing different types of fats.

The influence of dietary fat supplementations differing in the ratio of n-6 to n-3 polyunsaturated fatty acids (PUFA) on the effects of glucagon and insulin on plasma glucose, triglyceride (TG), and TG-rich lipoprotein concentrations was investigated in laying hens. Birds were fed either a low-fat control diet (LF) or diets supplemented with 4% pumpkin seed oil (PO; rich in n-6 PUFA) or 4% cod liver oil (CO; rich in n-3 PUFA). After 4 wk feeding of the experimental diets, hens were implanted with wing vein catheters and injected with porcine glucagon (20 microg/kg BW) and porcine insulin (0.5 IU/kg BW), 2 to 5 h after oviposition. Plasma glucose, TG, and TG-rich lipoprotein concentrations were determined from 10 min pre-injection to 60 min post-injection. PO diet resulted in a prolonged plasma glucose response to glucagon administration and altered hypoglycemic response to insulin. However, CO diet did not influence plasma glucose response to either glucagon or insulin administration compared to LF diet. The effects of glucagon and insulin on plasma TG and TG-rich lipoproteins were similar for all diets regardless of the amount or type of fat. The results suggest that feeding dietary fats with high n-6 to n-3 PUFA ratio alters the glucagon and insulin sensitivity of plasma glucose in laying hens. Fats rich in n-3 PUFA seem to have no influence on the plasma glucose response to glucagon and insulin.

Animals↗
PubMed2002

A combined electrophysiological and behavioural study for the assessment of activity-dependent changes in mice.

Activity-dependent adaptive changes in the nervous system involve structural and functional changes in the cortical circuitry. In this work the cortical function was studied by repeated recording of the somatosensory and motor potentials evoked by whisker deflections after altered sensory-motor experience in adult mice. The latencies of motor and somatosensory evoked potentials were found to shorten, while their amplitudes decreased, after a behavioural challenge involving the vibrissal apparatus. Sensory deprivation achieved by whisker trimming resulted in a partial reversal of the changes observed after increased activity. The derived parameters imply that cortical information processing speeds up as a result of experience, while decreased activity has the opposite effect. The methods used throughout the experiment were minimally invasive, and thus proved to be sufficient for the long-term follow-up of cortical functions.

Animals↗
PubMed2002

Investigations on rhizoplane Actinobacteria communities of papyrus (Cyperus papyrus) from an Egyptian wetland.

Wetlands have important global ecological functions, which include carbon storage and water interception. Wetland contributes to the maintenance of regional and global biodiversity. Though many important wetland ecological functions are based on microbial metabolism, we have scanty knowledge on microbial diversity in wetlands. Plant rhizoplane habitats are considered to harbor highly diverse bacterial communities. Most of the floating mats on river Nile are dominated by papyrus (Cyperus papyrus). Papyrus root samples were collected from a floating mat at the "Gold Island" inside the Nile River at Cairo, Egypt in February 1996 and May 1997 in order to investigate the rhizoplane actinobacteria communities. The root-tip regions were cut off, repeatedly washed, macerated and plated. Using the plate-count technique with three actinobacteria media, an average of 2.1 x 10(4) CFUg-1 root actinobacteria were obtained. All actinobacteria colonies were isolated, purified and investigated by classical and molecular methods. In the papyrus rhizoplane Streptomyces anulatus, Micromonospora sp., Rhodococcus luteus, Verrucosispora gifhornensis and Aureobacterium liquefaciens dominated, moreover Actinoplanes utahensis, and Str. diastaticus were also present. The physiological traits of the members of dominant groups revealed that these bacteria might be active in the rhizoplane and can be present there is their vegetative forms.

Actinobacteria↗
PubMed2001

[High dosage brachytherapy and external irradiation of localized prostate carcinoma--results at the Kiel University Clinic].

To evaluate a new therapy protocol for local dose escalation by high dose rate (HDR) brachytherapy for survival, morbidity and prognostic variables in men with localized prostate cancer. The prospectively recorded files of 189 men aged in median 69 years with a mean follow-up of 6 years (12-143 months) receiving curatively intended combined high dose rate (HDR) 192-iridium-brachytherapy (BT) and external beam radiation (EBR) for locally confined prostate cancer were analyzed. Mean age was 68.2 (range 44-84 years). Hundred and twenty-seven patients had T1-2 tumors, and 62 patients had T3-tumors. The total planned dose applied by external beam radiation was 50 Gy in the pelvis, and 40 Gy in the prostate by in-field-dose modification. The HDR-brachytherapy was delivered in two fractions. The dose per fraction amounted 15 Gy. Mean survival was 6 years (range 12-143 months), 76.7% of the patients survived and 86.3% were disease-free. The biochemical non-evidence of disease rate (BNED) was 78%. Univariate survival analysis revealed that low stage (T1-2), low grade (G1-2), normal PSA status after radiation therapy, and no adjuvant hormonal treatment were associated with long survival. However, the stratification for adjuvant hormonal treatment was not according to random. In multivariate analyses PSA status was an independent prognostic factor. The six year results confirm that local dose escalation by HDR-brachytherapy and external beam radiation is curative in men with locally confined prostate cancer. The results are especially in high risk patients encouraging.

Aged↗
PubMed2001

[Treatment of acute necrotizing pancreatitis: a comparative study].

The authors compared the therapeutic results of acute necrotizing pancreatitis during two separate time periods involving 97 and 24 patients, respectively. In the group "A", the time period lasted between May 31, 1991 and December 31, 1997. This group consisted of 97 patients, who, in addition to undergoing intensive treatment and antibiotic prophylaxis, later underwent late necrectomy and closed peripancreatic drainage. Jejunal nutrition only occurred in a limited number of 52 patients (53.6%), and was mostly used after a second operation. The group "B" consisted of patients from the time period between January 1, 1999 and December 31, 1999, and consisted of 24 patients treated in each case with intensive treatment in addition to antibiotic prophylaxis, early nasojejunal nutrition, and if necessary CT-guided percutaneous peripancreatic drainage was used. In the case of surgical intervention necrectomy and closed peripancreatic rinsing drainage was used. In group "A", significantly more early operations were performed than in group "B" (31 patients, 32.0% vs. 2 patients, 8.3%). In group "A" the number of reoperations was also higher as a total of 91 (83.5%) were reoperated as compared to group "B" in which a total of 18 (75.0%) reoperations took place. In the group "B", mortality was also lower (12.5%), than in the "A" group (17.5%). The authors attribute the successful therapy to the early jejunal nutrition, CT-guided percutaneous peripancreatic drainage and to the introduction of prophylactic antibiotics.

Adult↗
PubMed2001

Event-related potentials from a visual categorization task.

Investigation of the neural bases of human perceptual categorization is a continuously growing territory of visual sciences. Recently, several papers appeared on the cortical bases of human categorization performance, using functional brain imaging techniques such as positron emission tomography (PET) or functional magnetic resonance imaging (fMRI). However, the cheaper commercially available laboratory tests are not always the best methods to study multiple aspects of visual categorization. In this study, we describe the electrophysiological correlates of natural scene categorization in humans. The subject's task was to decide whether briefly presented natural scenes contained animal or non-animal items. Analysis of event-related potentials (ERPs) recorded during the categorization task, revealed more negative potentials for non-animal stimuli (NAS) in the time windows of 150-250 ms (N1) and 350-500 ms (N2), and more positive potentials for animal stimuli (AS) in the time window of 250-350 ms (P2). Our work provides an inexpensive noninvasive method to study both early perceptual and late phases of semantic information processing by recording ERPs during the categorization of natural scenes.

Evoked Potentials, Visual↗
PubMed2001

Schineria larvae gen. nov., sp. nov., isolated from the 1st and 2nd larval stages of Wohlfahrtia magnifica (Diptera: Sarcophagidae).

Four bacterial strains were isolated from the fly larvae of an obligate parasitic fly, Wohlfahrtia magnifica (Diptera: Sarcophagidae). These isolates were characterized by a polyphasic approach and represent a new lineage of gamma-Proteobacteria as their closest relative is Xylella fastidiosa (87.1% 16S rDNA similarity). The four strains are identical at the 16S rDNA level, the level of similarity between them, based on DNA-DNA hybridization, is high (97.8-102.5%) and they are similar in their physiological and biochemical characteristics, although they differ in their utilization of different sole carbon sources. All produce chitinase. They are obligately aerobic: no growth is detected under anaerobic conditions, even in the presence of NO3- as terminal electron acceptor. Their predominant respiratory quinone is Q-8. The G+C content of their DNA is 42 mol%. Their cell membrane contains phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and two unknown polar lipids. Their main fatty acids are C18:1, C16:0 and C14:0. To accommodate these bacteria, a new genus, Schineria gen. nov., with the type species Schineria larvae sp. nov., is proposed.

Animals↗
PubMed2001

Phylogeny of six naviculoid diatoms based on 18S rDNA sequences.

18S rDNA sequences of six Naviculaceae species [Amphora montana, Gomphonema parvulum, Eolimna minima (syn. Navicula minima), Eolimna subminuscula (syn. Navicula subminuscula), Navicula veneta and Phaeodactylum tricornutum] were determined in order to assess the monophyly of this important group of diatoms, to date not included in 18S rDNA databases, and also that of the recently described genus Eolimna. Phylogenetic trees were constructed using other known diatom 18S rDNA sequences, and best tree topologies obtained were tested against alternative trees for their reliability. The analyses do not reject the monophyly of Naviculaceae and strongly support the separation of the genus Eolimna from Navicula sensu lato. The two species of Eolimna, however, do not appear to be each other's closest relatives among the species investigated: rather, E. subminuscula shows affinities to A. montana, and E. minima to P. tricornutum. A. montana, a species which it has been proposed should be transferred into a separate taxon from the other five species, was found to have grouped well within them in all analyses.

Base Sequence↗
PubMed2001

[Treatment results of childhood Hodgkin's lymphoma in Hungary]

Lymphomas are the third most frequent malignancies in childhood. The Hungarian Pediatric Oncology Group was founded in 1971, and since then the same chemotherapeutic protocols have been used in the whole country. In this study we analyzed the data of childhood Hodgkin's lymphoma in Hungary in the last 11 years (1988-1998). We also compared our results with the international (German) data. The incidence of Hodgkin's lymphoma (0-15 years) was 7.1/1,000,000 child/year (the same for non-Hodgkin's lymphoma was 7.5/1,000,000/year); 5.5% of all pediatric malignancies in Hungary). The patients were treated according to the German DAL-HD-82 and 90 protocols. The therapy consisted of 2-6 cytostatic blocks, depending on the stage, followed by involved field irradiation. The overall survival was 94.7+/-2.0% at 5 years and 91.9+/-2.7% at 10 years. These results are very similar to the German data: 94% at 5 years and 93% at 10 years. The good results are due to the well organised network and the uniformed treatment. The results may be ameliorated by using autologous bone marrow transplantation.

Journal Article↗
PubMed2000

Percutaneous video choledochoscopic treatment of retained biliary stones via dilated T-tube tract.

BACKGROUND: Retained biliary stones is a common clinical problem in patients after surgery for complicated gallstone disease. When postoperative endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy are unsuccessful, several percutaneous procedures for stone removal can be applied as alternatives to relaparotomy. These procedures are performed either under fluoroscopic control or with the use of choledochoscopy, but it is also possible to combine these methods. METHODS: Since 1994, we have used the percutaneous video choledochoscopic technique for the removal of difficult retained biliary stones via dilated T-tube tract in 17 patients, applying the technique of percutaneous stone extraction used in urology. While waiting for the T-tube tract to mature and after the removal of the T-tube, the dilatation of its tract was 26-30 Fr. Stone removal was carried out using a flexible video choledochoscope and a rigid renoscope under fluoroscopic control, with the aid of Dormia baskets, rigid forceps, and high-pressure irrigation. RESULTS: We performed 23 operative procedures, and the clearance of the biliary ducts was successful in all cases. There were no major complications or deaths. CONCLUSION: Percutaneous video choledochoscopic-assisted removal of large retained biliary stones via the T-tube tract is a highly effective and safe procedure. Its advantages over other procedures include the ability to visualize the stones and noncalculous filling defects; it also guarantees that the stones can be removed under visual video endoscopic control. It has no problems related to tract or stone size.

Adult↗
PubMed2000

[Results of limb-saving surgery and prognostic factors in patients with osteosarcoma].

Ninety six patients with high-grade osteosarcoma of the extremities were treated between 1986 and 1997 in the authors institution. They were divided into three groups: in group I, all of 75 patients with non-metastatic OS received intensive chemotherapy and underwent surgery. In group II, 9 patients already had metastases at the time of referral. In group III, 12 patients received chemotherapy in delayed or suboptimal form. In group I, local recurrences occurred in 7 per cent (3 patients), metastases in 20 per cent of the patients with limb-saving, whereas these numbers were 3 per cent and 38 per cent in the amputation group. The 5-year disease free survival (DFS) was 72% v 69% in the limb-saving and amputation group, respectively. In groups II and III, 5-year DFS was extremely poor, 10 and 20% only. With univariate analysis, factors having a positive influence on the survival were: tumor volume < 60 cm3, wide or radical surgical margin, distal location of osteosarcoma, cartilagineous ground substance less than 20% and response to chemotherapy. The last 4 variables maintained their significance in the multivariate Cox model as well. Age > 30 showed indirect negative influence on the final outcome (enhanced intolerability to the drugs and less co-operability of the patients etc.). This data confirm the competence of the limb-saving surgery at certain indications beside the amputation.

Adolescent↗
PubMed2000

Laparoscopic unroofing of retroperitoneal lymphoceles after bilateral retroperitoneal lymphadenectomy for testicular cancer.

BACKGROUND: Symptomatic lymphoceles after retroperitoneal lymphadenectomy for testicular cancer are a rare complication that can be managed by either a computed tomography (CT)-guided subcutaneous aspiration or surgery. One surgical method of choice is laparoscopic unroofing. METHODS: One case of two retroperitoneal lymphoceles managed by laparoscopy is presented. After successful creation of pneumoperitoneum, first trocar insertion, and lysis of adhesions, the two lymphoceles were unroofed, and specimens from the wall and fluid were taken. RESULTS: Laparoscopic surgery was uneventful, and the patient returned to activity and work within 14 days after the operation. No pathologic signs of malignancy were discovered during biopsy and cytology investigations. At the 1-month follow-up assessment, CT scan demonstrated the regression, and 1 year later the total absence of the lymphoceles. CONCLUSIONS: After retroperitoneal lymphadenectomy for testicular cancer, clinical suspicion should remain high to detect and properly treat symptomatic lymphoceles. Large retroperitoneal lymphoceles can be treated effectively by unroofing under the safe direct vision of the laparoscope.

Adult↗
PubMed2000

Coding of spatial co-ordinates on neurones of the feline visual association cortex.

The receptive field properties of 131 visual neurons lying along the anterior ectosylvian sulcus were studied with extracellular recordings in barbiturate-anaesthetized, immobilised, artificially ventilated cats. A stationary visual noise pattern was presented in an area of 24x32 degrees, in which an 8x8 degrees portion moved randomly at a speed of 10 deg/s. A definite best area characterized by maximal firing rate was found, from where the firing rate declined monotonously towards the periphery of the receptive field. The best area locations were distributed in a 40x40 degrees region around the area centralis. These results seem to verify a rather robust capacity in AEV neurones for stimulus localization, in spite of their immense receptive fields.

Analysis of Variance↗