Biomedical subjects

O Kelemen

Publications and source records attributed to O Kelemen.

14 recordsLinked to original sources

PubMed2004

Patients with schizophreniform disorder use verbal descriptions for the representation of visual categories.

BACKGROUND: Neuropsychological impairment is a common finding in schizophrenia. However, a significant proportion of patients are not impaired in conventional neuropsychological tests. In this study, we investigated whether remitted patients with schizophreniform disorder exhibited dysfunctions in specific cognitive tasks. METHOD: Twenty remitted, highly functioning patients with schizophreniform disorder and 20 control subjects participated in the study. In addition to background neuropsychological evaluation (WAIS-R IQ, Wisconsin Card Sorting Test (WCST), Trail Making B, Rey Osterrieth Complex Figure), subjects received a category learning task. The categories consisted of geometric shapes systematically changing in shape and size. Training included the sequential presentation of category members (visual learning) and verbal description of categories. RESULTS: The patients with schizophreniform disorder had normal IQ, executive functions/psychomotor speed (WCST and Trail Making B) and visual memory (Rey-Osterrieth Complex Figure). In contrast, they displayed impaired categorization performances after visual learning. The performance of the patients improved markedly after verbal description of categories. Verbal knowledge about categories positively correlated with categorization performance in the patients, but not in the controls. CONCLUSIONS: Category learning functions, which include decision-making under uncertainty and feature integration, are impaired in patients with schizophreniform disorder who display normal executive functions and visual memory. These patients may use verbal knowledge as a compensatory strategy in visual tasks.

Adult↗

PubMed2004

No evidence for impaired 'theory of mind' in unaffected first-degree relatives of schizophrenia patients.

OBJECTIVE: The aim of this study was to investigate the possibility that 'theory of mind' (ToM) impairments are associated with schizophrenia liability. METHOD: Forty healthy control subjects and 79 first-degree biological relatives of schizophrenia patients (32 siblings and 47 parents) received the Eyes Test, during which subjects are asked to choose the word best describes the mental state of a person whose eyes are depicted on a photograph. RESULTS: The affected relatives (n = 14) performed worse on the Eyes Test compared with the controls (P = 0.0001), whereas the unaffected relatives (n = 65) showed intact performances (P = 0.4). The Eyes Test values did not correlate with age and IQ. There was no significant difference between male and female participants. CONCLUSION: ToM deficits, as measured by the Eyes Test, are not associated with schizophrenia liability.

Adult↗

PubMed2001

Intact prototype learning in schizophrenia.

In this study, we examined executive functions and visual prototype learning in patients with schizophrenia (n=22) and matched healthy control subjects (n=20). The patients demonstrated marked perseveration in the Wisconsin Card Sorting Test (WCST), whereas they successfully learned prototypes of dot-pattern category exemplars. These findings are against the hypothesis of a pure generalized cognitive dysfunction in schizophrenia, providing preliminary evidence for intact neocortical mechanisms related to perceptual classification functions.

Adult↗

PubMed2001

Remitted schizophrenia-spectrum patients with spared working memory show information processing abnormalities.

Working memory and information processing abnormalities are often reported in schizophrenia. The aim of this study was to examine visual backward masking (BM) functions in remitted schizophrenia-spectrum patients with spared working memory functions. Seventy-two patients with DSM-IV schizophrenia-spectrum disorders were screened using the Wisconsin Card Sorting Test (WCST) and the digit span forward/backward tasks. Patients with spared WCST and digit span performances were selected and administered a spatial working memory test and two BM procedures (target identification and location). The schizophrenia-spectrum group with spared WCST and digit span performances included individuals with schizophreniform disorder (N=11), schizophrenia (N=2), and schizoaffective disorder (N=2). These patients were clinically remitted and demonstrated spared IQ, normal spatial working memory, and relatively high psychosocial functioning. However, there was a significant impairment in the BM procedure, most prominently in the target location task and at short interstimulus intervals. These results suggest that the BM dysfunction is a trait marker of schizophrenia-spectrum disorders and may be present in the absence of working memory abnormalities.

Adult↗

PubMed2001

Are Alzheimer's disease patients able to learn visual prototypes?

Recently, controversial results emerged regarding visual prototype learning in Alzheimer's disease (AD). The aim of this study was to elucidate this issue in a larger population of AD patients. The AD patients (N=72) and age-matched healthy control subjects (N=25) learned to recognize and to categorize visual dot patterns. In comparison with the control subjects, the AD patients as a group showed dysfunctions in the recognition task, whereas categorization was relatively spared in their case. Recognition was impaired in patients with mild AD (Mini-Mental score: 18-23) and moderate AD (Mini-Mental score<18), whereas categorization was impaired only in patients with moderate AD. These results suggest that while the medio-temporal/diencephalic explicit memory system is markedly affected even in early AD, the sensory neocortical areas mediating implicit category learning display a sufficient degree of functional capacity until later stages of the disease.

Aged↗

PubMed2001

Different trait markers for schizophrenia and bipolar disorder: a neurocognitive approach.

BACKGROUND: The aim of this study was to assess visual information processing and cognitive functions in unaffected siblings of patients with schizophrenia, bipolar disorder and control subjects with a negative family history. METHODS: The siblings of patients with schizophrenia (N = 25), bipolar disorder (N = 20) and the controls subjects (N = 20) were matched for age, education, IQ, and psychosocial functioning, as indexed by the Global Assessment of Functioning scale. Visual information processing was measured using two visual backward masking (VBM) tests (target location and target identification). The evaluation of higher cognitive functions included spatial and verbal working memory, Wisconsin Card Sorting Test, letter fluency, short/long delay verbal recall and recognition. RESULTS: The relatives of schizophrenia patients were impaired in the VBM procedure, more pronouncedly at short interstimulus intervals (14, 28, 42 ms) and in the target location task. Marked dysfunctions were also found in the spatial working memory task and in the long delay verbal recall test. In contrast, the siblings of patients with bipolar disorder exhibited spared performances with the exception of a deficit in the long delay recall task. CONCLUSIONS: Dysfunctions of sensory-perceptual analysis (VBM) and working memory for spatial information distinguished the siblings of schizophrenia patients from the siblings of individuals with bipolar disorder. Verbal recall deficit was present in both groups, suggesting a common impairment of the fronto-hippocampal system.

Adult↗

PubMed2000

Schizophrenics know more than they can tell: probabilistic classification learning in schizophrenia.

BACKGROUND: Previous studies have demonstrated impaired explicit and preserved implicit memory functions in schizophrenia. However, it is less clear whether schizophrenics can learn complex information (e.g. probabilistic stimulus response associations) with or without access for conscious recollection. In this study we applied a classification learning task to assess explicit and implicit processes concurrently. METHODS: Two test procedures were administered to 40 schizophrenic subjects and 20 healthy volunteers: a probabilistic classification learning (PCL) task to evaluate implicit memory functions; and a category cue recognition test to investigate the explicit memory system. The PCL task included feedback guided category learning of geometrical shapes. These shapes were called category cues, predicting class membership with certain probabilities. The gradual increase of categorization performance during the feedback learning was a potentially implicit process, whereas the subsequent recognition of category cues required explicit memory functions. RESULTS: The schizophrenic patients improved their categorization performance to a similar extent to the controls, but they failed to recognize the category cues. Memory performances were independent of the positive and negative symptoms. CONCLUSIONS: Patients with schizophrenia were able to establish representations of complex categories, but these remained unconscious. This is consistent with earlier reports, suggesting damaged explicit and spared implicit memory in schizophrenia.

Adult↗

PubMed1999

Laparoscopic cholecystectomy in acute cholecystitis.

The authors retrospective analyze the role of golden standard laparoscopic cholecystectomy for the treatment of acute cholecystitis. They make a comparison between the results of 50 early cholecystectomy and 44 "a froid" cholecystectomy (operation was postponed until 6 weeks after acute cholecystitis had healed). From January 1997 to December 1998 536 laparoscopic cholecystectomies were performed. In 491 cases (91.6%) laparoscopic, and in 45 cases (8.4%) traditional (opening) method was indicated. Converted cholecystectomies were in 36 cases (7.3%). Agreeing to the literature they can determine the optimal timing of the operation in 72 hours from the onset of acute cholecystitis [2, 4]. In this group (first group) there were 50 cases, with 14 conversions (28%). In the second group (postponed, so called "a froid" phase) there were 44 patients. From this group was the intraoperative diagnosis serious acute-subacute cholecystitis in 24 cases (54.54%) causing complicated laparoscopic cholecystectomy and resulting in 11 conversions (11/44: 25%). The causes of the higher rate of conversion were the grave inflammation and slow dissection of central formation. There were no serious complication and mortality in both groups. It was diagnosed bile leak (two cases) which ceased spontaneously, one haematoma in abdominal layers, and one trocar's hernia. The authors have recommended the laparoscopic cholecystectomy for early diagnose acute cholecystitis in order to prevent the complications and reduce the sick-leave. Supporting their viewpoint the most important clinical end economical facts are: the recurrence of inflammation forced urgent surgery and caused more complication in the course of "a froid" phase there were scrutable anatomical situation the patients recovered in a shorter time.

Acute Disease↗

PubMed1999

The laparoscopic technique for bilateral inguinal hernias.

From March 1994 to March 1999 359 laparoscopic hernioplasties have been performed on 295 patients. In 349 cases (97.2%) TAPP (transabdominal preperitoneal), in 10 cases (2.8%) TEP (total extraperitoneal) method was used for the treatment. In 64 cases (21.7%) bilateral hernias were operated using TAPP-method only. There were 15 hidden hernias and 14 recurrences on the contralateral side in this group. The hernial ring was covered with two smaller meshes or one bigger. There were no intraoperative complications. In 21 cases (32.8%) subcutaneous emphysema and in 3 cases (4.6%) sero-haematoma was developed. The emphysemas were solved spontaneously in 2-3 hours after the surgery. One haematoma was needed punction. The patients were discharged from the hospital on the second or third postoperative day. The authors found that the bilateral laparoscopic hernioplasty much more favourable for the patients.

Adolescent↗

PubMed1999

Synchronically performed laparoscopic cholecystectomy and hernioplasty.

Cholecystectomies and hernioplasties are the two most frequently performed surgical interventions. The laparoscopic technique can be offered for the simultaneous treatment with both operating indications. The synchronical operation can give all the advantages of the minimally invasive technique. Authors had performed laparoscopic cholecystectomy with laparoscopic hernioplasty in five cases. Two inguinal and three postoperative hernias were reconstructed. The cholecystectomy was performed with a "three punction method", and the hernioplasty by using the same approach, completed by inserting a fourth assisting trocar as required. The hernial ring was covered with an intraperitoneally placed mesh, which was fixed by staplers (the so-called "IPOM-method": intraperitoneal on-lay mesh). There was no intra-, nor postoperative complication. The hernioplasty combined with laparoscopic cholecystectomy did not have effect on postoperative pain and nursing time. The return to the normal physical activity was short, similar to laparoscopic hernioplasty (in 1-2 weeks). Authors conclude that the simultaneous, synchronous laparoscopic cholecystectomy and hernioplasty is recommended and should be the method of choice because it is more advantageous for patients.

Adult↗

PubMed1998

Abstraction is impaired at the perceptual level in schizophrenic patients.

This study investigates category learning in schizophrenia in order to evaluate abstraction abilities at the perceptual level. The participants learned about two categories of geometric shapes. The category exemplars were presented successively. In the case of schizophrenic patients, longer exposure time and more stimulus presentations were used to counterbalance attention impairments. In spite of this, the perceptual category learning was significantly impaired in the patient group. In contrast, when the training procedure involved verbal category definition and not perceptual learning, the performance of schizophrenics was similar to that of the healthy controls. These findings suggest that the perceptual learning of categories, but not free classification judgements are impaired in schizophrenia, and that this impairment is not due to pure attentional disturbances.

Adult↗

PubMed1997

Transabdominal preperitoneal herniorraphy: technique and results.

As enthusiasm for laparoscopic surgery has grown, laparoscopic approaches to the groin hernia have evolved. The most widely accepted laparoscopic repair employs the placement of a large sheet of mesh in a preperitoneal position to cover potential hernia spaces. Between March 1994 and February 1997 160 inguinal and 3 femoral hernia were operated of an transabdominal preperitoneal (TAPP) polipropylen mesh. 131 patients were operated (128 males and 3 females, ranging in age from 19 to 82 years), 31 (23%) of them had bilateral hernias. Recurrent hernia was the indication in 52 (32%) cases. Average operating time for unilateral repair was 80 minutes and for bilateral repairs was 108 minutes. Postoperative complications included 7 (4.3%) cases of transient neuralgias, 20 (12%) cord/scrotal transient seromas-hematomas and 2 (1.2%) hydrocele. The 5 (3.1%) early recurrences were considered to be caused by technical inexperience and/or too small prosthetic patch. The laparoscopic hernioplasty has definitive advantage: minimal postoperative pain, short hospital stay (average postoperative time of hospitalization 3.1 days) and early restoration of full physical activity (in 1 to 2 weeks). The method should be considered as a potential "best option" in patients with recurrences and bilateral inguinofemoral hernias.

Abdomen↗

PubMed1997

The blood supporting of nipple-areolar (NAC) complex performing for mammaplasties.

In case of mammaplasties the blood support of the nipple-areolar complex is one of the most important. The authors give a comprehensive clinical summary of the operating technics which are suitable to correct mastoptosis and breast hypertrophy (or macromastia). After mentioning the anatomy, blood and nerve supply of breast, following the classifying of mastoptosis and breast hypertrophy. Summarizing of the historical development of operating methods, which resulting in modern solutions, and adding Hungarian-related data. The widely used mastopexies and reduction mammaplasties will be analyzed, with demonstration of transposition of NAC using different kind of dermo-glandular flaps, e.g.: Skoog-, Pitanguy-, McKissock-, Strömbeck-, Robbins-, Regnault- and other's method. After discussing the possible postoperative complications, authors underline the necessity of detailed analysis and exact planning in varied clinical cases for achieving wanted functional and aesthetic result. Attaching importance to have more perfect operating techniques.

Breast↗

PubMed1997

The cryovaricectomy (demonstration of a new method).

The operating technique of the primary varicosity has changed recently. The subcutaneous methods have been used nowdays. We give account of making 416 cases by cryovaricectomy, which is a quite new method. Using this technic we can remove the dilated venous branches during a 3-4 millimeters wide incision of skin and preserve the sufficient main vein. Summarizing of our advantageous experience: the cryovaricectomy is suitable for principles of minimally invasive surgery, and the operating time is much more briefer, the aesthetic results are best, the attendance far shorter and the postoperative complaints of patients much more fewer.

Collateral Circulation↗