Shozo Ishii

Electron microscopic study of the blood-brain-barrier in brain swelling

I t is often observed that the brain increases in volume secondary to many pathological processes; e.g. head injury, brain tumor, vascular accidents, endogenous and exogenous intoxications etc. The resultant pathological changes in the brain have been called brain swelling by some, brain edema by others**. As yet, there has been no unanimity of opinion regarding the fundamental pathological alteration. Brain swelling has also been produced experimentally by directing noxious lesions to the cerebral vessels or the brain tissue itseff 6, but the method employed or resultant pathological changes sometimes differ fundamentally from those active in the clinically observed cases. I t soon becomes apparent that the experimental 10roduction of brain swelling which shows far-reaching static and dynamic similarities to the clinical cases is not an easy task. Light microscopy, because of its inherent limitation of resolution, fails to reveal the fine and delicate alterations in nervous tissue which is undergoing the changes manifes~ in brain swelling. I t appears, therefore, that one must have two conditions satisfied in order to properly study brain swelling in the experimental animals; (1) a method of producing brain swelling which is constant in its effects, which acts upon both the cerebral tissue and cerebral vessels, and which closely resembles mechanisms active in producing brain swelling in man; (2) a proper method which permits the study of the ultra-structural components of the tissue and cells concerned with the least artefacts. We believe that a variant of the method of producing brain swelling first introduced by Ist t~ et al. 15 satisfies the first pre-requisite, and that the electron microscope satisfies the second. I t must be borne in mind that our method offers only one way of approach in the problem, and that it makes no at tempt at the physico-chemicM study of brain swelling, a question which is of paramount importance.

Ontogenic studies on the rat brain capillaries in relation to the human brain tumor vessels

SummaryOne of the major morphological disparities of brain capillaries between newborn or young and adult rats might be reflected in the aspect of development of the basement membrane. The basement membrane in young animals is clearly evident to be poorly developed up to 15 days of age, and then better developed to possess some similarity to that in adult animals. In addition, it also should be emphasized that slightly distended extracellular space is evident in the nervous tissue of newborn animals.Although in malignant astrocytoma some small blood vessels do not possess any perivascular space around them, others evidently have narrow or relatively wide perivascular spaces where some fibrils of mesodermal origin and fibrocytes can be clearly seen. Also, in some astrocytomas, wide extracellular space is distributed extensively all over the tumor tissue.However, in this context the immaturity of endothelial and glial cells in both young animals and brain tumors should be duly considered.The permeability of the brain capillaries in both young animals and brain tumors has been very well known to be higher than that of the adult brain tissue. However, the higher permeability has another significance, from the morphological point of view, in young animals than it has in brain tumors.ZusammenfassungEiner der hervorstechendsten morphologischen Unterschiede zwischen den Hirncapillaren neugeborener und junger oder erwachsener Ratten kommt in der Entwicklung der Basalmembran zum Ausdruck. Bei jungen Tieren bis zu einem Alter von 15 Tagen ist die Basalmembran wenig ausgebildet, mit fortschreitendem Alter der Tiere tritt die Ähnlichkeit mit der Basalmembran von erwachsenen Tieren ausgeprägter in Erscheinung. Außerdem ist zu betonen, daß im Nervengewebe neugeborener Tiere etwas erweiterte extracelluläre Räume zu beobachten sind.Im maligen Astrocytom gibt es kleine Blutgefäße, die keine perivasculären Räume besitzen, andere dagegen haben deutliche engere oder verhältnismäßig weite perivasculäre Räume, in denen mesodermale Fibrillen und Fibrocyten zu finden sind. In manchen Astrocytomen sind im gesamten Tumorgewebe weite extracelluläre Räume vorhanden.Allerdings müßte hier die Unreife der Endothelzellen und der Gliazellen bei jungen Tieren wie auch bei Hirntumoren in Rechnung gestellt werden.Es ist bekannt, daß sowohl bei jungen Tieren wie auch bei Hirntumoren die Permeabilität der Hirncapillaren höher ist als bei erwachsenen Tieren. Vom morphologischen Standpunkt jedoch bestehen in den Voraussetzungen der erhöhten Permeabilität bei jungen Tieren einerseits und bei Hirntumoren andererseits deutliche Unterschiede.

Cavernous hemangioma with bone formation in a child: case report.

A 13-year-old girl suffering from seizures who was found to have hemangioma calcificans in the frontal lobe was surgically treated. The favorable postoperative course of our patient as well as reported cases suggest early excision of the lesion if it is located in an accessible area. Histological examination confirmed ossification with marrow in the lesion. The literature regarding ossification in the brain is discussed briefly.

Calcified cerebellopontine angle hematoma mimicking recurrent acoustic neurinoma

The authors describe a case of calcified, organized hematoma in the cerebellopontine angle which developed 20 years after subtotal removal of an acoustic neurinoma, presenting as a recurrence of acoustic neurinoma on computed tomography. It points out the difficulty in differentiating a recurrent tumor from an organized hematoma in this particular case because of neuroradiological similarity and masked clinical symptoms by the long-standing neurological deficits after the original surgery. MRI scanning would have been helpful in this circumstances.

Analysis of Factors Contributing to Cerebrovascular Autoregulation

It is generally accepted that acute brain swelling develops under a variety of pathological conditions and is primarily due to augmentation of cerebrovascular volume. This should be differentiated from cerebral edema in the classical sense, which developes more gradually around the damaged cerebral tissue.

EXPERIMENTAL STIJDY ON POSSIBILITY OF THE FUNCTIONAL RESTORATION AFTER ANASTOMOSIS BETWEEN A SPINAL NERVE AND THE VAGAL NERVE

In 1828 Florence first reported that it was possible for the central cut end of one spinal nerve to accomplish a functional union with the peripheral cut end of another nerve, both severed and each different in its innervating area. Later, in 1898 Langley showed that this union could also be accomplished between the somatic and the autonomic nerves. Following this, a number of similar experiments were carried out by Navra t i l , Jackson (hypoglossal nerve-recurrent laryngeal nerve), Hors ley (accessory nerve-recurrent laryngeal nerve), M iskaoski (cervical sympathetic nerve-recurrent laryngeal nerve), Budge t t & Snodgress, Mimura (vagus-cervical syinpathetics) and Nnkamura (vagus-spinal nerve). In particular, Lnngl ey and Anderson 11904) advanced the knowledge in this line by an extensive experiment. However, in all but few of these experimental works series, striated muscles (skeletal muscles, diaphragm, thyroarytenoid muscle, etc.) were chosen as the effect organ regarding the peripheral piece of the anastomosed nerves. Thus, criteria for the functional union or failure in union between the anastomosed nerves have been established by examining whether the striated muscle did really contract by electrical stimulation of the proximal piece of the anastomosis or not. However, only a few experiments have been made concerning the response in the muscles innervated by the autonomic nerves, e. g. those of the stomach or the intestine or the heart. Such were the experiments of Rawa and Calugareana in which the anastomosis was effected between the hypoglossal and the vagal nerve. H e r e , several months after the operation the hypoglossal nerve was electrically stimulated and a decrease in pulse rate was found resulting