Anulus fibrosus in bulging intervertebral disks

In this investigation the association of radial tears of the anulus fibrosus and bulging of the intervertebral disk was studied. An index of disk bulging was measured in sagittal anatomic sections in 149 lumbar disks from 31 cadavers. The indexes of disk bulging were correlated with stages of disk development and the presence of an annular tear. The largest disk-bulging indexes were always associated with radial tears of the anulus. Eighty-four percent of the disks with radial tears had disk-bulging indexes greater than 2.5 mm. Most normal adult disks had an index of less than 2.5 mm. The results challenge the concept that the anulus fibrosus is intact in bulging disks, although ruptured in herniated disks.     

New x-ray tube performance in computed tomography by introducing the rotating envelope tube technology

The future demands of computed tomography imaging regarding the x-ray source can be summarized with higher scan power, shorter rotation times, shorter cool down times and smaller focal spots. We report on a new tube technology satisfying all these demands by making use of a novel cooling principle on one hand and of a novel beam control system on the other hand. Nowadays tubes use a rotating anode disk mainly cooled via radiation. The Straton x-ray tube is the first tube available for clinical routine utilizing convective cooling exclusively. It is demonstrated that this cooling principle makes large heat storage capacities of the anode disk obsolete. The unprecedented cooling rate of 4.8 MHU/min eliminates the need for waiting times due to anode cooling in clinical workflow. Moreover, an electronic beam deflection system for focal spot position and size control opens the door to advanced applications. The physical backgrounds are discussed and the technical realization is presented. From this discussion the superior suitability of this tube to withstand g-forces well above 20 g created by fast rotating gantries will become evident. Experience from a large clinical trial is reported and possible ways for future developments are discussed.     

痛

黑暗!黑暗!!黑暗!!!这样的世界看不到半点光明。孤独的舞者终究还是孤独地倒下,然后又孤独地消失。黑暗呀,为什么老是缠绕着我?一声“妈妈”划破了天际,却也突不出黑暗的包围。谁来应我一声呀,妈妈,你在哪里呀?我的心在不停地挣扎,告诉自己:“不怕,不怕。”可这是在黑暗里呀,周     

Increase of food intake induced by glucagon in the rat

The effect of intraperitoneal administration of saline, glucose (25 mg/100 g b.w.), insulin (0.025 U/100 g b.w.) and glucagon (50 micrograms/kg b.w.) on glycemia, liver glycogen concentration and food intake was studied on 104 male adult Wistar rats. When saline was injected the amount of food ingested was similar to that expected at the metabolic moment selected for the tests. Glucose administration did not reduce food intake but both insulin and glucagon provoked a threefold increase during the 60 minutes ensuing the injection. The overall ingestion of food during the 24 hours after the injection of the hormones was significantly higher (about 10%) than the control values during the preceding or the succeeding 24 hours. A hyperphagic, rather than a hypophagic effect of glucagon administration is possibly related to the small dose used in the experiments. The mechanisms involved in the increase of food intake due to glucagon are discussed in terms of acceleration of the metabolic reactions that normally prevent large drops of glycemia as glucose utilization proceeds during the inter-meal periods and that in physiological conditions build up until the need for food arises.     

Functional analysis of plasma fibronectin with special consideration of binding interferences

So far, soluble fibronectin has been quantitated mostly by immunological techniques. In this investigation we show that an immunological assay provides reliable results only with intact fibronectin. Fibronectin fragments resulting from proteolysis give rise to falsely raised values. We present four functional tests based on the sandwich (ELISA) technique on microtitre plates. These quantify fibronectin on the basis of its binding capacity to collagen, heparin, fibrin and carboxy-group-modified IgG with high sensitivity, specificity and precision. Analysis of the bioactivity spectrum of intact fibronectin is not disturbed by fibronectin fragments. Furthermore we demonstrate interferences, in particular between heparin and collagen in their mutual binding to fibronectin. This provides new indications of a "substrate activation" of fibronectin.     

Adjustments and Leak Detection of the Adjustable Silicone Gastric Band (ASGB) and Lap-Band™ Adjustable Gastric Band (LAGB) System

Background: The detection of a leakage in the system of the adjustable silicone gastric band (ASGB) may be difficult. Gastrografin injection into the port should be avoided because it acts like a glue and blocks the system. Methods: A syringe containing saline and a syringe containing Thallium-201 chloride is connected to the 4-way stopcock which is connected to the needle. The needle is pushed into the port. The position is confirmed by injection and aspiration of saline. 2 ml of TL-201 chloride (74 MBp) is injected to locate the leakage in the system with planar images with a gamma camera (Elscint SP 6), 30 min, 2, 3, and 24 h after injection. Results: The original ASGB was provided with an injection reservoir which, in our series, was found to be leaking in four cases (3%). Conclusions: Our technique for adjustments and leak detection appears to be simple and effective. Band-related problems such as reservoir leak should disappear with improvement of the material.     

Effects of (S)-ketamine on striatal dopamine: a [11C]raclopride PET study of a model psychosis in humans

Administration of the N-methyl-D-aspartate (NMDA) antagonist S-ketamine in normals produces a psychosis-like syndrome including several positive and negative symptoms of schizophrenic disorders (Abi-Saab WM, D'Souza DC, Moghaddam B, Krystal JH. The NMDA antagonist model for schizophrenia: promise and pitfalls. Pharmacopsychiatry 1998;31:104-109). Given the clinical efficacy of dopamine (DA) D2 receptor antagonists in the treatment of positive symptoms, it is conceivable that S-ketamine-induced psychotic symptoms are partially due to a secondary activation of dopaminergic systems. To date, animal and human studies of the effects of NMDA antagonists on striatal DA levels have been inconsistent. The present study used positron emission tomography (PET) to determine whether a psychotomimetic dose of S-ketamine decreases the in vivo binding of [11C]raclopride to striatal DA D2 receptors in humans (n = 8). S-ketamine elicited a psychosis-like syndrome, including alterations in mood, cognitive disturbances, hallucinations and ego-disorders. S-ketamine decreased [11C]raclopride binding potential (BP) significantly in the ventral striatum (-17.5%) followed by the caudate nucleus (-14.3%) and putamen (-13.6%), indicating an increase in striatal DA concentration. The change in raclopride BP in the ventral striatum correlated with heightened mood ranging from euphoria to grandiosity. These results provide evidence that the glutamatergic NMDA receptor may contribute to psychotic symptom formation via modulation of the DA system.     

Early stage nasopharyngeal carcinoma: radiotherapy dose and time factors in tumor control

OBJECTIVE: To evaluate radiotherapy dose and length of treatment in the control of early stage nasopharyngeal carcinoma (NPC) treated with a combination of external radiotherapy and brachytherapy, MATERIALS & METHODS: We reviewed the records of 133 patients with early stage nasopharyngeal carcinoma (stage I or II, AJC/UICC staging system) who received definitive radiotherapy in Chang Gung Memorial Hospital from 1979 to 1991. The median follow-up time was 7.1 years with a minimum of 2 years. All patients were treated with megavoltage external radiotherapy to the nasopharynx area (63-72 Gy) followed by high dose rate intracavitary brachytherapy (5-16.5 Gy in one to three fractions, spaced 1-2 weeks apart). The median total dose and time of irradiation was 75 Gy (69.8-81.4 Gy) and 11.6 weeks (7.8-20 weeks) respectively. Survival analysis was used to examine the effect of several variables on prognosis. RESULTS: The 5-year rates were 86.4% for local control, 84.7% for disease free survival, 88.5% for actuarial survival and 84.2% for overall survival. The treatment group (combination of time and dose of irradiation) was the most important prognostic factor according to Cox's proportional hazard model. Patients receiving radiation at a total dose of < or = 75 Gy completed in < 12 weeks showed the best prognosis. CONCLUSION: Treatment time and total treatment dose are both important factors in treating early stage NPC. Decreasing the total radiation time to < 12 weeks and not exceeding a radiation dose of 75 Gy gave the best results.      

Mood state and brain electric activity in ecstasy users

Resting EEG during open and closed eyes and subsequent mood ratings were obtained from 15 Ecstasy users and 14 Ecstasy-naive controls. Absolute spectral power on the scalp, and the three-dimensional, intracerebral distribution of neuroelectric activity using low resolution brain electromagnetic tomography (LORETA) were computed. LORETA revealed global increases of theta, alpha 1 and beta 2/3 power during eyes open in Ecstasy users, and spectral analyses revealed a right-posterior increase of alpha 2 power (confirmed by LORETA) and increased beta band activity during open eyes. Ecstasy users had higher levels of state depressiveness, emotional excitability and a trend-level increase in state anxiety. The observed differences may be related to regular exposure to Ecstasy or other illicit drugs, or may be pre-existing.