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The lifetime of the τ lepton is measured using the process e+ e- → τ+ τ- , where both τ leptons decay to 3πν(τ). The result for the mean lifetime, based on 711  fb(-1) of data collected with the Belle detector at the ϒ(4S) resonance and 60  MeV below, is τ=(290.17±0.53(stat)±0.33(syst))×10(-15)  s. The first measurement of the lifetime difference between τ+ and τ- is performed. The upper limit on the relative lifetime difference between positive and negative τ leptons is |Δτ|/τ<7.0×10(-3) at 90% C.L.

We report the observation of two narrow structures in the mass spectra of the π(±)Υ(nS) (n=1, 2, 3) and π(±)h(b)(mP) (m=1, 2) pairs that are produced in association with a single charged pion in Υ(5S) decays. The measured masses and widths of the two structures averaged over the five final states are M(1)=(10,607.2±2.0)  MeV/c2, Γ(1)=(18.4±2.4)  MeV, and M(2)=(10,652.2±1.5)  MeV/c2, Γ(2)=(11.5±2.2)  MeV. The results are obtained with a 121.4  fb(-1) data sample collected with the Belle detector in the vicinity of the Υ(5S) resonance at the KEKB asymmetric-energy e+ e- collider.

Since brain damage in closed head injury of acceleration-deceleration type depends on the site of impact and on the course of the traumatising force, a reconstruction of these was attempted using CT. The study included 45 standard CT studies of adults with closed acceleration-deceleration head injuries. We selected 32 patients exclusively on the basis of CT findings of soft tissue contusion, skull fractures and cerebral contusions (coup and/or contrecoup, as well as other parenchymal lesions), while in the remaining 13 patients clinical findings were also used. On CT, the axial section of the skull was divided into 12 sections imitating the clock-face, to permit computerised graphic presentation of the direction of the traumatising force. Analysis of cerebral contusions on different CT studies in each case allowed location of "dominant coup" and "dominant contrecoup" lesions to be determined. The site of impact and the course of the traumatising force were reconstructed and graphically presented on the basis of these findings, supplemented with data on soft tissue contusions (present in 71% of cases), skull fractures (in 36%) and sometimes on other brain lesions. Comparison of the computerised graphic presentation of the site of impact and direction of the traumatic force and the location of lesions revealed a high correlation between them. In 80% of cases, the site of impact could be visualised only by CT. The acceleration force acted along the longer axis of the head (centroaxial or semioblique) in 87% and along the shorter axis in 13% of cases. Multiple lesions were found in 87% of cases. The lesions were most frequent in the frontal (51%) and temporal (26%) lobes. CT was very useful for reconstruction of the site of impact and of the course of the traumatising force in acceleration head injury. Data obtained by this procedure may have far-reaching prognostic and forensic implications.

Introduction: The delivery of radiofrequency (RF) energy through conventional catheter electrodes is often associated with coagulation necrosis at the tissue-electrode interface, with resultant impedance rise and limited lesion size. This study was performed to examine the effects of catheter tip cooling during RF delivery, to test the hypothesis that such cooling would decrease the likelihood if impedance rise and allow the creation of larger endomyocardial lesions., Methods and Results: The experiments were performed in eight open chest, anesthetized sheep. RF lesions were created within both ventricular chambers of each animal through a catheter tip that could be cooled with a saline perfusate. Assignment of cooled versus noncooled RF delivery to either ventricle was alternated from one animal to the next. In each set of experiments, lesion volumes relative to the mode of RF delivery were compared. The mean power delivered via the cooled electrode (22.04 +/- 4.51 W) was significantly higher than that delivered via the noncooled electrode (6.10 +/- 2.47 W; P < 0.001). The mean duration of RF delivery was 42.7 +/- 11.2 sec for noncooled lesions versus 49.2 +/- 6.8 sec for cooled lesions (P < 0.01). Mean lesion volume was 436.07 +/- 177.00 mm3 for noncooled RF delivery versus 1247.78 +/- 520.51 mm3 for cooled RF delivery (P < 0.001). This significantly larger lesion size with cooled RF delivery was associated with no instance of impedance rise in 27 attempts versus 11 impedance rises in 28 attempts with noncooled RF (P < 0.001)., Conclusions: Delivery of RF energy through a cooled catheter tip allows the creation of larger endomyocardial lesions by limiting the occurrence of impedance rise despite the delivery of greater energy. These observations suggest that, under certain conditions, resistive tissue heating at a distance from the site of current delivery may play an important role in RF ablation therapy.

Between August 1991 and December 1992, CT was performed on 154 patients who had suffered missile head injury during the war in the Republic of Croatia. In 54% CT was performed 1-24 h after injury, and in 27% follow-up CT was also obtained. The wounds were penetrating, tangential or perforating (45%, 34% and 21%, respectively). Haemorrhage was the most frequent lesion in the brain (84%). Follow-up CT evolution of haemorrhage, oedema, cerebritis, abscess, secondary vascular lesions, necrosis, encephalomalacia and hydrocephalus. The most dynamic changes occurred 7-14 days after injury. In 14% of cases, deep cerebral lesions were found in the corpus callosum, septum pellucidum periventricular region and pons, although bone and shell fragments were in a different part of the brain parenchyma. Such lesions were found in penetrating injuries only. CT proved very useful for assessing the extent and type of lesions. Although different mechanisms of brain damage in missile head injury are known, here they are, to the best of our knowledge, shown for the first time by CT.

A method which enables analysis of DNA from archival paraffin embedded normal and malignant brain tissue is described. The demonstration of a 317-bp long beta-actin DNA sequence by the polymerase chain reaction (PCR) was used to identify which fixation procedure, deparaffinization time and DNA extraction procedure would give the best results. Tissue specimens 1-39 years old were included in the experiments. Specimens fixed in either 10% formalin, Carnoy's or AMeX fixative were found to be best suited for subsequent analysis by PCR. Paraformaldehyde and acetone compromised amplification efficiency, while Bouin's fixed tissue gave uniformly negative results. Regardless of fixative used, PCR reaction had to be run through at least 40 cycles. Prolonged deparaffinization time and phenol/chloroform extraction of DNA did not influence DNA quality as a template for PCR reaction. Formalin fixed brain tumours can be successfully used for DNA/PCR analysis even if they are up to 39 years old.

A 14-year old boy was admitted for signs of heart failure and scapuloperoneal muscle weakness. He fulfilled the clinical, functional and diagnostic criteria for dilated cardiomyopathy. There was also a moderate increase in pulmonary vascular resistance. The immunohistochemical examination of the heart muscle revealed a slightly positive phytohemagglutinin reaction and minimal IgM deposits without complement. The electron microscopy examination disclosed increased numbers of abnormal mitochondria disrupting the usual cell structure; the mitochondria were of various sizes with irregular and abnormal structure of the cristae. The scapuloperoneal spinal muscular atrophy was mild and diagnosed according to clinical and electromyographic findings. Light microscope examination of the skeletal muscle revealed hypotrophic fibers. This patient is presumed to have postinflammatory mitochondriopathy and is currently being managed on low-dose digitalis, diuretics and captopril.

Computed tomographic analysis of lesions of the corpus callosum in 13 patients with "inner cerebral trauma" showed significant congruence of linear translation of acceleration and the topographic distribution of such lesions. This congruence permits computed tomography to be used to reconstruct the course of linear translation and the site of the main blow, which can be important for forensic use. The findings of even a small lesion in the corpus callosum indicates the need for further investigation of other structures which are usually involved in inner cerebral trauma, such as the hippocampus and brain stem.

A group of 42 patients with closed head injuries of acceleration type is reported. All of them were treated at various departments of the General Hospital in Maribor. The aim of investigation was to find out the diagnostic possibilities of head and brain damages in closed head injuries of acceleration type by the method of computed tomography (CT) and making comparison with the clinical picture of each individual patient. The patients were not investigated at random but were grouped in accordance with the direction of traumatic force action. The CT analyses were performed according to characteristic patterns of traumatic brain disease. The circumstances of head injury were reliable guidelines for devoting more attention to some brain areas. The density of each lesion was examined, too. The investigation has shown that lesions of "inner cerebral trauma" pattern (ICT-Grcević 1965) are visible on CT at least as often as coup-contrecoup lesions or even more. Only in cases with latero-lateral direction of traumatizing force (control group) coup-contrecoup lesions were found more frequently. Deep cerebral lesions of the latero-lateral type of acceleration head trauma were never or seldom encountered.

On computed tomography (CT) layers through the tumor the quality of picture depends upon the tumoral tissue structure, i.e., upon its histological appearance. In the formation of this histological appearance to a greater or lesser extent a series of various elements are involved, which are responsible for the density on CT scan, e.g., blood vessels, fatty tissue, calcium, connective tissue, collagen, etc. For some tumors the most important characteristic is specific organization of tissues in the volume, which can be clearly seen on high-quality CT scan. Possible limitations are due to technical capabilities of a CT apparatus. In our study we have obtained the most valuable results by analyzing the quality of picture of neurinomas on the so-called native CT scans, and by evaluating the way in which the picture of the tumoral tissue changed by opacification after an intravenous injection of contrast medium. Our study included 23 intracranial neurinomas. Twenty of them were neurinomas of the statoacoustic nerve, 1 of the orbit, 1 of the Gasser's gaglion and 1 was in the parasagittal region. For each particular tumor on histological specimens Antoni A and Antoni B types of tissue were semiquantitatively identified. In our study we have chosen only those cases for which we had a plenty of tumoral tissue suitable for semiserial analysis. The results of the histological analysis were compared with the results of the CT assessment of the tumoral tissue. Larger necrotic areas and cystic formations within tumoral tissue, which we could not analyze on our histological specimens, were excluded from the evaluation of CT scans of these tumors. Our results indicate a positive correlation between the histological appearance of neurinomas and their CT scans. This correlation between the histological properties of the tumoral tissue and the CT scan was almost 100% in those cases in which one histological type of neurinomas significantly prevailed. The prevalence of one type of neurinoma tissue was found in 74% of cases. In almost 61% of neurinomas in the histological appearance Antoni A type of tissue prevailed, what was clearly seen on CT in the form of hyperdense areas of the tumor. Antoni B type of tissue was histologically found in about 13% of neurinomas. These tumors had a marked hypodense picture of the tumoral tissue. The rest of neurinomas had mixed types of tissue. In this group of tumors we could not use the CT findings as an indicator in preoperative analysis of histopathological tissue characteristics.

Subdural hematoma (SDH) develops as a result of bleeding in the subdural space. According to nowadays accepted division, three groups of subdural hematomas can be differentiated: acute, subacute and chronic. The time elapsed from the moment of the occurrence of the hematoma to the moment when it was diagnosed is the main factor for determining the stage of SDH. However, for the above-mentioned types of SDH, this time differs depending on the author reporting it. Subdural hematoma is most often diagnosed by means of computerized tomography (CT). This method is safe and reliable, giving the exact diagnosis in more than 90% of cases. According to the basic principle of the concept of "living pathology", the knowledge of histological appearance of an investigated lesion is essential for the diagnostic interpretation of this lesion in neuroimaging methods. Very few authors studied the histological picture of subdural hematoma. The only structure which was histologically examined in details was the subdural neomembrane. Studies correlating histological picture of SDH and its appearance on CT scans have not been carried out until now. In this work such a correlation was made, and some regularities connecting these two methods were pointed out. Hyperdense picture of SDH on CT scans represents a hematoma containing almost only erythrocytes and erythrocyte-fibrin component being formed. Hypodense picture of SDH on CT scans represents a hematoma containing fibrin and inflammatory cells. Hematomas of mixed density on CT scan in all cases contained a neomembrane. Obvious histological differences between the mentioned types of subdural hematoma have led to the conclusion that chronic subdural hematoma is not the last stage of an "old" acute SDH. Chronic and acute subdural hematomas are different entities, considering their etiopathogenetic and clinical picture, and especially their CT and histopathological appearances.

A case of endotheliomatous type of meningioma arising from the falx and dura of the left anterior cranial fossa is reported. Numerous Rosenthal fibres were observed in the gliotic tissue around the meningioma. Authors present a brief data about the nature and occurrence of Rosenthal fibres. The occurrence of the pilocytic astrocytes and Rosenthal fibres in the gliotic tissue around slow-growing falx meningioma is an additional evidence for a peculiar type of changes in astrocytes of the long-standing gliosis of piloid type.

This study deals with the topographic distribution of traumatic lesions in the corpus callosum within the pattern of "inner cerebral trauma". Material for neuropathological investigations consisted of 49 brains of patients who suffered closed head injury of the acceleration type with linear translation of acceleration acting along the longer axis of the head. As a control, 5 brains were investigated in which the direction of linear translation was latero-lateral. The patients were divided into 4 groups according to reconstruction of the traumatic event and ascertaining of the direction of the linear translation of acceleration: (1) Medial blow (antero-posterior and postero-anterior), (2) Semioblique left blow (frontal left-occipital right and occipital right-frontal left), (3) Semioblique right blow (frontal right-occipital left and occipital left-frontal right), (4) Vertex-base direction. Fornix and septum pellucidum, as anatomically adjacent structures were also investigated. The results showed that the lesions in the corpus callosum were related to the pattern of "inner cerebral trauma" (ICT) (Grcević 1982), and the biomechanical conditions originally proposed by Lindenberg. These investigations, carried out on a representative material of 54 brains and by subserial histological analysis of the entire corpus callosum, produced a new evidence for our previous preliminary observations about the correlation of the shape and distribution of the periaxial lesions of the pattern of "inner cerebral trauma" and direction of the linear translation of accelerating forces. Our present investigations showed a striking congruence between the pattern of lesions within the corpus callosum in such type of cerebral trauma and the course of linear translation of acceleration. Furthermore, this study proved the importance of topographic interpretation of lesions in the corpus callosum in vivo i.e. by the CT and MRI examinations, because they may serve as a significant information for reconstruction of the biomechanical conditions of the injury which can be of importance for early therapeutical strategy and forensic interpretations of the accident. By using silver impregnation-techniques for histopathological study of the corpus callosum, we could confirm our previously expressed concept on "focalized" and not "diffuse" axonal injures in ICT (Grcević 1988). In this study corpus callosum served as a representative anatomical structure for axonal studies showing that axonal lesions strictly follow the pattern of tissue lesions with definite focal principle.

Autosomal dominant motor and sensory neuropathy with liability to pressure palsies was studied in three members of the same family. Only one of two monozygotic twin sisters was clinically affected. She developed unilateral peroneal palsy twenty minutes following local pressure. Electromyography revealed a weak intermediate innervation pattern with very rapid action potentials in the right anterior lower leg muscle. A 25-70 per cent reduction of motor and sensory conduction velocity was recorded in the clinically unaffected twin sister and in the father. The electrophysiological findings in the mother were normal. The sural nerve biopsy revealed "sausage-like" formations. The palsy persisted for two months and disappeared after eight weeks of fluocortolon treatment. It is possible that the myelin sheaths acted as antigen.

In this paper three cases with peculiar disease of the cerebellar cortex are presented. The disease is well known as L'hermitte-Duclos disease (LDD), but nowadays it is also called "dysplastic granulo-molecular hypertrophy of the cerebellar cortex" according to the modern theories of its etiology. Curious changes of the cerebellum in LDD are probably the result of a combination of delayed migration of Purkinje cells which occurs during the intrauterine period of cerebellar development, and of reactive hypertrophy of granular cells. Presented cases of L'hermitte-Duclos disease are, according to the literature, more or less typical by their clinical appearance and by their histological findings. Our electromicroscopical data support the findings of those authors who found only axodendritic sinapses on the hypertrophied ganglion cells, according to the idea that those cells are originally granular cells of the cerebellar cortex. CT scan of all our patients revealed parallel, worm-like, hyperdense formations in a hypodense process of the cerebellum. The same picture existed in some other described patients, but attention was paid to it. We consider this picture on the computed tomography to be characteristic, if not even patognomonic for the L'hermitte-Duclos disease, which gives us an entirely new scientific contribution in the process of the diagnosis of this peculiar disease.

A case of medullomyoblastoma, arising in the cerebellar vermis of a five-year-old boy, is presented. The light and electron microscopic features of the tumor are described and compared to other published cases. Within typical medulloblastoma areas light microscopy revealed signs of neuroblastic differentiation thus indicating its neuroepithelial origin. No signs of glial differentiation were found. Myogenic tumor component formed irregular, distinctly separated islands although some intermingling of two cell types was observed at the borders between the two zones. Within the myogenic tumor component, electron microscopy revealed rhabdomyoblastic elements in different stages of differentiation, frequently forming small groups encompassed by the same basement membrane. No indication of a common host cell for two cell lines was observed. No mesenchymal elements other than muscle, and no indication of possible teratoid origin of this tumor were observed. Considering histogenesis of muscle elements within this neuroepithelial tumor, the origin from multipotential neural-crest-derived ectomesenchymal cells seems the most appropriate one.

A group of 110 patients (68 male and 42 female) with cerebral metastases, treated at the Institute of Clinical Oncology and Radiotherapy, Zagreb University School of Medicine, during the period 1978-1984, were included in the study. Most patients were aged 50-60 years. Out of 110 patients, 52 were treated by radiotherapy and 58 by radiotherapy plus chemotherapy. Metastases from the bronchus carcinoma, breast carcinoma, melanoma and gastrointestinal carcinoma were present in 59%, 21.8% and 4.6% of patients, respectively. In 1.8% metastases from hypernephroma and in 3.6% from other malignant tumors were observed. In 4.6% cases, the origin of metastases could not be identified. Fifty-two out of 110 patients were treated by radiotherapy alone. They received 3000 cGy in 8-10 fractions, to the whole brain, with two parallel opposed fields. Fifty-eight out of 110 patients treated with radiotherapy and chemotherapy were given the same radiotherapeutic treatment. Chemotherapeutically, they were treated with BCNU and CCNU with or without Vincristin in standard doses. In the group of 52 patients treated by radiotherapy alone the median survival was six months (1-16 months), i.e. the same as in the group treated by both radiotherapy and chemotherapy (1-26 months).

A case of neuro-cutaneous melanoma, in the course of which a bifocal melanoma of the cerebral hemisphere had developed, was used as a natural model for the study of the relation between tumorous and non-tumorous elements. The need is pointed out for the definition of such a cutaneous-meningeal syndrome before the development of a neoplasm. As tumours develop from the cells defining leptomeningeal melanosis, the possibility of a neuroradiological diagnosis of this process is accentuated, primarily by a minute examination of the sites characteristic of the disease. A premorbid detection of all such cases is imperative in order to introduce an early anti-tumour treatment.

The authors present a case of herpes-simplex encephalitis in a 58-year-old woman. The disease had a biphasic course and lasted 87 days. The clinical picture, laboratory data and the pathologic-anatomical changes of the disease are discussed. The authors also emphasize the importance of the encephalitic process in the brain stem, which can make the clinical picture even more complicated because of the appearance of respiratory disturbances.

Since the first report of a defibrillation attempt with an intracardiac catheter electrode nearly 30 years ago, investigators have developed implantable electrode systems consisting of metal disks, endocardial catheters, and epicardial patches. These early efforts demonstrated the feasibility of low-energy reversion of ventricular tachyarrhythmias, and also provided some insight into the mechanisms of fibrillation and defibrillation. This review describes the evolution of implantable defibrillator electrode systems. Early investigators attempted defibrillation with submuscularly implanted metal disks or a disk electrode paired with an endocardial catheter electrode. Electrode design emphasis turned to transvenous catheter systems with electrodes placed in the right ventricle and right atrium. A more successful configuration placed the proximal electrode in the superior vena cava. In an effort to ensure proper placement of the distal electrode in humans, the catheter was replaced with an epicardial patch. More recently, a combination of electrodes and multiple pulses has substantially reduced the energy required to defibrillate. Effective electrode systems that can convert lethal arrhythmias with a minimum of energy will aid in making implantable cardioverters and defibrillators the therapy of choice in patients at high risk of sudden coronary death.

The authors present results of histological and electron-microscopical investigations of muscular tissue obtained by biopsy from a 20-year-old man, who showed typical features of Marfan's syndrome associated with slowly progressive muscular weakness. The muscle showed a peculiar combination of centronuclear myopathy with hypotrophy of type I fibres and the so called "fingerprint myopathy". The combination of such myopathic phenomena with Marfan's syndrome presents a unique and hitherto undescribed condition.

The authors report on 79 cases of primary brain sarcomas, correlating clinical and pathoanatomical data. In the material analyzed the group of gliosarcomas prevailed, while the smallest group were rhabdomyosarcomas. In some groups the topic predilection did not show any specific characteristics, except that there were more gliosarcomas occurring in the parietal lobe. The symptoms lasted 1-3 months before operation.