Accumulating evidence indicates that various neurotrophic factors (NTFs) exist and function in the brain. In the mature mammalian brain, NTF expression is exclusively restricted to neurons. However, astrocytes activated by various cytokines, including fibroblast growth factor and interleukin-1β, produce a significant amount of nerve growth factor (NGF) in vitro. Furthermore, non-NGF type NTF expression in astrocytes is also activated by the cytokines. The cytokines also enhance both release of ciliary neurotrophic factor from and expression of high-molecular weight basic fibroblast growth factor (FGF) in astrocytes. In the early phase following brain injury, cytokine-activated astrocytes rescue the damaged neurons via NTFs and other biologically active molecules.
Mice and other small animals are often used in experimental studies on central nervous disorders. If the intrathecal administration of certain sub-stances is required in such experiments, the substances are usually adminis-tered by cisternal puncture under general anesthesia. In work on metabolic aspects of diseases, however, general anesthesia is disadvantageous since it influences cerebral metabolic conditions.The present authors thus developed a technique for intrathecal adminis-tration by lumbar puncture in the mouse under local anesthesia. Although it may appear that correct positioning of a mouse could be difficult under local anesthesia, the authors were able to ensure a satisfactory posture by pulling the bilateral ears and tail gently in the craniocaudal direction. In order to puncture the mid-point of the spinous processes accurately in the mouse, we observed the spinous processes directly through a lumbosacral incision in the skin.In order to test the reliability of our technique, trypan blue and 5% glucose were administered to mice intrathecally.Based on macroautograms obtained at 30 min after intrathecal admin-istration of 25 μl of trypan blue, the intrathecal injection of trypan blue by our technique was judged to be successful in 95% of the twenty mice.Twenty-five μl of 5% glucose was administered intrathecally to mice and the intracerebral water content was estimated at 10, 20, 30, 40, 50, 60min after the administration following decapitation.No marked change in intracerebral water content was observed at 10min after the intrathecal administration, but at 20min a significant rise in water content was found (p<0.05). The water content tended to decrease there-after and at 30min it dropped to the pre-administration level.It is considered therefore that the intrathecally administered glucose affected the intracerebral water content in some definite way, thereby demon-strating the reliability of our method.Compared to cisternal puncture, the present technique for lumbar punc-ture offers several advantages.1) It can be carried out under lacal anesthesia.2) Practically, it is a simpler procedure than cisternal puncture.3) It is reliable, giving a high success rate of over 95%.
A multicenter cooperative study was conducted to investigate factors influencing posttraumatic epilepsy (PTE) and to evaluate the prophylactic effect of anticonvulsants. A retrospective study of 102 PTE patients revealed the following typical clinical features: occurrence in young males, traffic accidents, contusion and/or cerebral hematoma. The latent period after the injury was longer in children. The percentage of EEG paroxysmal activity gradually increased as the generalized abnormality diminished. A retrospective-prospective study of 1998 patients who suffered a head injury between 1984 and 1988 was conducted till 1994. During the follow-up period, 62 patients (3.1%) developed PTE. The drop-out cases were excluded, and the 154 cases followed at least two years were analyzed. Statistical analysis of differences between patients with and without PTE suggested following factors: young, immediate early epilepsy (within 24 hours after injury; IMEE) and early epilepsy (within one week after injury). The risk with the highest relative risk rate was early epilepsy. Multiple regression analysis revealed that three factors, IMEE, early epilepsy and young age, contributed to the prediction of PTE. There was no significant difference in the percentage of patients having PTE in the group treated with anticonvulsants and the untreated group. Anticonvulsant treatment after head injury was unlikely to have a prophylactic effect on the development of PTE.
For the past three years (from April 1968 to March 1971) We have treated 90 cases of the intracranial berry aneurysms (81 patients).at Kitano Hospital, Osaka, and discussed the symptomatology, diagnostic method and surgical technique too.1) We have had 22 aneurysms located at the junction between the carotid artery and the posterior communicating artery (ICPC-aneurysm).12 cases out of 22 aneurysms developed paresis of the unilateral oculomotorius nerve.7 cases out of the above 12 cases combined with hemiparesis.There were also 2 cases of abducens paresis out of 22 ICPC-aneurysms.We have concluded the pathogenesis of oculomotorius paresis as the result of direct compression of the same nerve by the aneurysm.On the contrary, the abducens paresis might be the result of indirect compres sion of the abducens nerve in the cavernous sinus.2) We have had 28 aneurysms of the anterior communicating artery in which 6 cases revealed negative findings of aneurysm by the initial angiographic examination.3) As far as the surgical technique to the anterior communicating artery aneurysm is concern, there were several merit and dismerit between French's and Kempe's methods.We have concluded the surgical procedures to the aneurysm should be decided from the anatomical situation of it.
THE ATTACHMENT OF a thin silastic sheet combined with the use of Sugita's fenestrated aneurysm clip was developed for the emergency repair of vascular perforation during surgery. The sheet is flexible and tailored in the operating room, corresponds to the vascular curve, and is semitransparent, allowing observation of the area of perforation. The device can be applied under severe bleeding conditions without temporary clipping. It may be useful as an emergency tool for vascular repair in the operating room.
When a sitting operation is performed, early detection and prevention of air embolism are important. Air flow into the right heart system was monitored by a real-time two-dimensional echocardiograph in combination with a video-recorder. The heart was observed from the apical four chamber view by a ditector placed under the xiphisternum and directed towards the base of heart. The echocardiography showed two types of air flow; one was the single-bubble type in which several bubbles flowed from the right atrium to the right ventricle, and the other was the stormy-bubble type in which a great number of air bubbles flowed en masse. The single-bubble type was observed during surgery involving the skin, muscle, or bone, and the air flow in this type could be interrupted by electrocoagulation, bone wax, etc. The stormy-bubble type was noted during surgery involving the muscle or dura mater. The air flow from the dura mater was most frequently observed. Retroflexion of the dura mater and then electrocoagulation would be required to prevent the air flow from the cut end of the dura mater. If electrocoagulation does not control the air flow from the cut end of the muscle, massive muscle suture by thick threads could prevent the air flow. Air flow into the right heart system in a sitting operation was more frequent than has previously been believed, and a small amount of air flow was noted even during minor surgery. Therefore, application of. a sitting operation should be carefully undertaken. Ultrasonic tomographic monitoring of the heart was useful in the early detection of air embolism because of its non-invasive technique and its high sensitivity.
