Comment on "Berry phase correction to electron density of states in solids".
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Comment↗
Biomedical subjects
Z Horváth
Publications and source records attributed to Z Horváth.
Three-year results of the first educational and early detection program for testicular cancer in Hungary.
OBJECTIVE: To determine whether a testicular self-examination-based early-detection program may help in the early diagnosis of testicular cancer. METHODS: Advertisements were placed in the media describing the early signs of testicular cancer, the risk factors, the correct method of self-examination and the importance of early detection. Between April 1995 and April 1998, 5,056 men underwent physical and ultrasound examination of the testicles, and in case of suspicious findings tumor markers were checked. RESULTS: Testicular tumors were found in 1.28% of the men with symptoms. No tumors were found in men without symptoms or in men with pain, sensitivity to palpation, or complaints unrelated to the testicle. Of those with a palpable lump or swollen testicle, 4.5 and 3.9% were found to have a tumor. In total, 28 testicular cancers (15 seminomas and 13 nonseminomas) in 26 volunteers and 4 benign tumors were detected. The occurrence of cancer was most frequent in the age group of 15--40 years (1.6%). CONCLUSION: The rate of cancer detection and the detected seminoma rate in the program are not sufficient to justify a widespread early detection program for testicular cancer (examination of men who reveal testicular abnormalities by self-examination) despite the increased tumor incidence. Early diagnosis should be based on an educational program for the population at risk, the training of staff engaged in the health care of the young, and the use of early ultrasound examination in men with palpable lumps and swollen testicles, especially in young men.
Adolescent↗
Complete removal of colloid cyst via CT-guided stereotactic biportal neuroendoscopy.
Four patients harbouring a colloid cyst of the 3rd ventricle were operated on endoscopically. With the "classical" monoportal technique, through a precoronal burr hole only partial removal could be achieved in the first case. As the crucial point of the procedure is the safe dissection of the cyst from the thela chorioidea and from the internal cerebral veins, adequate control of the posterior rim of the foramen of Monro and the roof of the 3rd ventricle is mandatory. Accordingly in other three cases a CT-guided biportal endoscopic technique was applied, which permitted radical removal of the entire cyst with maximum safety. CT-guidance is essential for optimal planning after careful study of the individual anatomy. In this way the rigid scopes are moved exclusively along their own axes throughout the procedure, the resulting brain damage thereby being minimal. With regard to all circumstances of the procedure, the use of flexible endoscopes appears to be inappropriate and biportal endoscopy offers itself as the method of choice.
Adult↗
Fungal colonization of the esophagus in alcoholic liver disease.
OBJECTIVES: Little is known about the fungal colonization of the esophagus. Since alcoholic liver disease (ALD) patients are prone to fungal esophagitis, we have investigated the esophageal fungal colonization of this patient group. METHODS: One hundred consecutive ALD patients were enrolled in this prospective study. 22 patients with dyspeptic symptoms acted as controls. After taking an oropharyngeal swab, patients underwent an upper gastrointestinal endoscopy and surface material was obtained from the esophagus for direct smears and culture. RESULTS: In the ALD group pseudohyphae were found in 21.5% and yeast forms in 6.4% of the direct smears. The culture was positive in 40.8% of the ALD patients, the isolated strains were: 30 C. albicans, 2 C. kefyr, 2 C. krusei, 1 C. zeylanoides and in 3 cases the species could not be identified. 41.9% of ALD patients and 13.6% of control patients (p = 0.013) had fungi in their esophagus. Significantly more ALD patients had fungal esophagitis than in the control group (19.3% vs. 0%, p = 0.021), the rate of fungal colonization was also higher, but the difference was not significant (22.5% vs. 13.6%). A significantly higher rate of fungal esophagitis and esophageal colonization was found in patients with fungi in their oropharyngeal swabs (p = 0.00001). CONCLUSIONS: Fungal colonization of the esophagus is frequent in ALD patients. Its presence might have clinical significance in the case of liver transplantation.
Adult↗
Biportal endoscopic removal of a primary intraventricular hematoma: case report.
Primary intraventricular hematomas account for approximately 6% of all intracerebral hematomas. If the clot blocks cerebrospinal fluid (CSF) pathways, surgical intervention, which may be of different types, can be life-saving. In the case reported here, after careful preoperative planning the use of two rigid endoscopes permitted the removal of most of the intraventricular clot and restoration of CSF circulation by creation of a 3rd ventriculostomy within the same procedure and no later treatment was necessary. Repeated CT scans proved that only a small portion of the intraventricular clot remained in the ventricular system. The ventricular size normalised, and the patency of the artificial hole in the floor of the 3rd ventricle was demonstrated both by the rapidly improving clinical picture of the patient and by flow-sensitive MRI studies. For individuals who suffer primary intraventricular hemorrhage and later develop occlusive hydrocephalus, endoscopic removal of the clot and 3rd ventriculostomy might offer a more adequate treatment option than external ventricular drainage.
Adult↗
Peptidergic innervation of human cerebral blood vessels and saccular aneurysms.
Peptidergic innervation of the human cerebral vasculature has not yet been described in detail and its role in the maintenance of cerebral autoregulation still needs to be established. Similarly, few data exist on the innervation of vascular malformations. The aim of this study was to clarify the peptidergic innervation patterns of human cerebral arteries of various sizes, and, for the first time, that of saccular aneurysms. Light microscopic study of whole-mount preparations of human cerebral arteries and aneurysm sacs resected either during tumor removal or after neck-clipping were carried out by means of silver-intensified light microscopic immunocytochemistry visualizing neuropeptide-Y, calcitonin gene-related peptide and substance P immunoreactivity. Systematic morphological investigations confirmed the presence of longitudinal fiber bundles on the adventitia and a network-like deeper peptidergic system at the adventitia-media border, while in smaller pial and intraparenchymal vessels, only sparse longitudinal immunopositive axons could be detected. The innervation pattern was totally absent in the wall of saccular aneurysms with the complete disappearance of peptidergic nerve fibers in some areas. To the best of our knowledge neither the disappearance of this network on small pial and intraparenchymal vessels, nor the absence of an innervation pattern in saccular aneurysms have been described before. Nonhomogeneous peptidergic innervation of the human cerebral vascular tree might be one of the factors responsible for the distinct autoregulatory properties of the capacitance and resistance vessels. Malfunction of this vasoregulatory system might lead to the impairment of autoregulation during pathological conditions such as subarachnoid hemorrhage.
Cerebral Arteries↗
Transcranial Doppler-determined pulsatility index in the evaluation of endoscopic third ventriculostomy (preliminary data).
OBJECTIVE: Endoscopic 3rd ventriculostomy has become the method of choice in the management of occlusive hydrocephalus. The treatment is accompanied by significantly less peri-operative complications than the cerebrospinal fluid shunting procedures previously employed. Close surveillance of patients, however, is necessary to avoid the consequences of raised intracranial pressure that may develop in case of obstruction of the artificial outlet of the 3rd ventricle. The aim of this study was to confirm the value of transcranial Doppler-determined pulsatility index (PI) in the assessment of the patency of endoscopic 3rd ventriculostomy and to elucidate its usefulness in early postoperative recognition of increased intracranial pressure. METHODS: In twenty-two patients suffering from occlusive hydrocephalus, transcranial Doppler sonography (TCD) was performed before, immediately after, and five days after endoscopic fenestration of the floor of the 3rd ventricle. PI was defined with fast Fourier transformation. Mean PI values were determined in both middle cerebral arteries (MCA), over five cardiac cycles. RESULTS: In nineteen cases, PI values showed a significant decrease immediately as well as five days after the intervention as compared to the pre-operative values, and flow-sensitive MRI confirmed the patency of the fenestration in all cases. In one patient the operation failed to produce an effective diversion of cerebrospinal fluid as shown by flow-sensitive MRI, and the pulsatility index was unchanged. In two patients, a significant immediate postfenestration drop in PI was followed by a recurrence of PI to pre-operative levels without any clinical deterioration. CONCLUSIONS: Preliminary results suggest that the transcranial Doppler-determined pulsatility index is a useful non-invasive tool for the evaluation of the patency of the fenestration in the early follow-up of patients who underwent endoscopic third ventriculostomy.
Adolescent↗
Initial clinical experience with a combined pulsed holmium-neodymium-YAG laser in minimally invasive neurosurgery.
Various biophysical features of the laser beam have already been utilized in clinical neurosurgery. However, the application of this therapeutic modality has by no means been overexploited. The history of laser application in neurosurgery has shown that there is no universal laser system capable of performing all surgical tasks in a suitable manner. The best results in traditional neurosurgery were achieved with instruments combining various wavelengths, such as the CO2 and neodymium-YAG lasers. A pulsed holmium-YAG and neodymium-YAG (Ho:YAG and Nd:YAG) combined laser have been recently developed to meet the special requirements of minimally invasive neurosurgery. The system consists of a compact double-crystal single-head solid-state laser system generating 2 different wavelengths (Ho:YAG 2.08 microns and Nd:YAG 1.05 microns), selected for their capabilities of efficient coagulation and ablation. The two wavelengths are coupled into a common flexible optical fiber, which allows endoscopic application. The wavelengths can act simultaneously or separately without any interchange of the instruments. The system was employed first for experimental and subsequently for clinical purposes, primarily for endoscopic operations. In this work the initial clinical experience is reported. The excellent haemostatic properties of the Nd:YAG laser and the ablative properties of the Ho:YAG laser were confirmed. It was concluded that simultaneous application of the two laser modalities within one flexible fiber offers new perspectives in tissue handling in endoscopic neurosurgery and as in open microsurgery.
Adult↗
[Investigation of polysaccharides of Echinops species. Medicinal plant polysaccharides I].
Polysaccharides isolated from Echinops sphaerocephalus, Echinops ruthenicus, Echinops exaltatus, Echinops commutatus and Echinops orientalis (Asteraceae family) were investigated to study their qualitative and quantitative relations. The extracts of these studied plants have been used in traditional Chinese medicine as drugs with anti-inflammatory effect and anti-tumor promoting action in the osseous system [1]. We suppose that these biological effects are related to the polysaccharides especially to the acidic ones. The plant material was successively extracted with boiling water and six fractions were collected. The yield was 40-45%. The uronic acid content of these fractions, measured by the Bitter method, was relatively high 15-35% (Table I.). In case of Echinops sphaerocephalus different parts of the plant were investigated. The root and the stem are useful from a practical point of view because of the high uronic acid content. Some fractions, which seemed to be interesting on the basis of the measured uronic acid content, were dialyzed then concentrated, lyophilized and their uronic acid, protein and carbohydrate contents were determinated (Table III). The Echinops orientalis root fraction 6. was separated by ion-exchange chromatography. The monosaccharide composition of the neutral and the acidic fractions was measured by gas chromatography (Table IV).
Anti-Inflammatory Agents, Non-Steroidal↗
Biportal endoscopic management of third ventricle tumors in patients with occlusive hydrocephalus: technical note.
OBJECTIVE: To present the feasibility and advantages of the biportal endoscopic management of posterior third ventricle tumors. As a result of recent developments in neuroendoscopy, classical third ventriculostomy has become a standard single burr hole procedure and a real alternative to shunting in the treatment of occlusive hydrocephalus. In patients with third ventricle tumors occluding the aqueduct, the acute development of hydrocephalus may often precede debilitating focal symptoms and signs. Forty percent of those tumors are radiosensitive, rendering craniotomy unnecessary. The goal of primary management is the alleviation of raised intracranial pressure and determination of the histological nature of the tumor. Cerebrospinal fluid shunting and the performance of a computed tomography- or magnetic resonance imaging-guided biopsy are generally suggested as the methods of choice. METHODS: Three patients with posterior third ventricle tumors and acute hydrocephalus were treated in one session by computed tomography-guided endoscopic third ventriculostomy and endoscopic tumor biopsy was performed by means of two rigid ventriculoscopes. RESULTS: Ventriculostomy was performed in three patients, and tumor biopsy was performed in two patients. The maximum 40-minute operation did not involve mortality or morbidity. Histological findings were established in all patients. In two patients with malignant infiltrative tumors, postoperative radiotherapy was used; in one patient with a small cavernoma, no further measures were taken. At the 6-month follow-up, flow-sensitive magnetic resonance imaging confirmed ventriculostomy patency in all patients. CONCLUSION: The biportal endoscopic approach allowed independent visual control of both procedures, safe passages of the ventriculoscopes via the narrow foramen of Monro, and facile control of the intracranial pressure in the ventricles via the available four irrigation channels during the performance of tumor biopsy and fenestration of the floor of the third ventricle. In selected patients with infiltrating posterior third ventricle tumors, this procedure and postoperative radiotherapy may be an alternative to direct surgery or to shunting and performance of image-guided biopsy.
Aged↗
Form factors of the sausage model obtained with bootstrap fusion from sine-Gordon theory.
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Journal Article↗
Comparison of single-dose and 7-day fluconazole treatment of fungal esophagitis in alcoholic liver disease.
The aim of the study was to assess the effectiveness of a single-dose fluconazole treatment of fungal esophagitis in patients with alcoholic liver disease. Twenty-two alcoholic liver disease patients with fungal esophagitis were randomly assigned to receive either a single-dose of 150 mg fluconazole or a 7-day treatment of daily 50 mg fluconazole. Control esophagoscopy was performed in both groups on days 9-11. Direct smears and cultures on Sabouraud's medium were performed at both endoscopies. Patients' sera were tested for Candida antigens and for antibodies against Candida albicans on days 1, 8 and 15. Twenty patients (18 C. albicans, 1 C. tropicalis, 1 C. pseudotropicalis) completed the study, there were two drop-outs from the single-dose group. Antibodies against C. albicans were found in four cases, Candida antigens in five. There were no significant differences in the treatment outcome between the two groups, clinical cure was recorded in eight out of nine patients in the single-dose group and nine out of eleven patients in the 7-day group, mycological eradication in four out of nine, and in three out of eleven, respectively. Single-dose fluconazole treatment seems to be an effective therapy of fungal esophagitis in alcoholic liver disease patients.
Adult↗
Structural impairment of hippocampal neurons following a single epileptic afterdischarge.
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Animals↗
Free field representation for the O(3) nonlinear sigma model and bootstrap fusion.
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Journal Article↗
Genetic threshold hypothesis of neocortical spike-and-wave discharges in the rat: an animal model of petit mal epilepsy.
Neocortical high-voltage spike-and-wave discharges (HVS) in the rat are an animal model of petit mal epilepsy. Genetic analysis of total duration of HVS (s/12 hr) in reciprocal F1 and F2 hybrids of F344 and BN rats indicated that the phenotypic variability of HVS cannot be explained by a simple, monogenic Mendelian model. Biometrical analysis suggested the presence of additive, dominance, and sex-linked-epistatic effects, buffering maternal influence, and heterosis. High correlation was observed between average duration (s/episode) and frequency of occurrence of spike-and-wave episodes (n/12 hr) in parental and segregating generations, indicating that common genes affect both duration and frequency of the spike-and-wave pattern. We propose that both genetic and developmental-environmental factors control an underlying quantitative variable, which, above a certain threshold level, precipitates HVS discharges. These findings, together with the recent availability of rat DNA markers for total genome mapping, pave the way to the identification of genes that control the susceptibility of the brain to spike-and-wave discharges.
Action Potentials↗
Short-term and long-term changes in the postischemic hippocampus.
We have demonstrated a far more widespread and selective ischemic cell damage than previously thought. In area CA3, a distinct subpopulation of interneurons, characterized by their spiny dendrites and their calretinin content, was selectively vulnerable in the absence of any other CA3 involvement. In the dentate hilus, four different types of spiny cells were consistently damaged. The common denominator in these two cell groups is the presence of spines on their dendrites and hence the greater density of mossy fiber innervation they receive. A common mechanism of cell death may be the presence of non-NMDA receptor subtypes that are highly permeable to calcium. We speculate that they may constitute an important control mechanism in the CA3 region and the hilus, and impairment of this mechanism may be causal to delayed neuronal death in CA1. We have also shown that neuronal degeneration does not end after delayed cell death of CA1 pyramidal cells. Our results suggest that there is progressive degeneration throughout the life of the animal and degeneration of additional cell populations (e.g. CA1 interneurons and CA3 pyramidal cells) may also occur secondary to the insult.
Animals↗
[Cavernous angioma of the central nervous system].
The developmental and morphological characteristics, clinical course, diagnostic and therapeutic possibilities of cavernous angiomas of the central nervous system are summarized on the basis of the literature. The clinical courses of 27 patients with cavernous angiomas are presented. The surgical treatment of cavernous angiomas has had a good outcome when the indications and microsurgical principles were adhered to. Special attention should be paid to cavernous angiomas located near or inside the ventricles because of the danger they may cause.
Adult↗
An immediate morphopathologic response of a subpopulation of astrocytes to electroshock: "dark" astrocytes.
Varying numbers of astrocytes lining the subarachnoid and Virchow-Robin's spaces become stainable by a special silver method in brain sections of rats subjected to a single electroshock of "suitable" parameters immediately before being sacrificed by perfusion fixation. This type of argyrophilia is considered to be induced by some electrically caused morphological damage, since the affected astrocytes are dramatically shrunken and hyperchromatic at both light- and electron-microscopic levels. Based on several points of morphopathologic similarity between the electroshock-damaged astrocytes and "dark" cells of various tissues, especially electroshock-induced "dark" neurons, it is supposed that their nature is also similar ("dark" astrocytes).
Animals↗