S. Oya

Effect of fibrin glue on postlaminectomy scar formation

SummaryAn experimental study in rats has been carried out with the aim of studying the scar formation over the spinal dura in the presence of fibrin glue. Although the main action of fibrin glue is the enhancement of wound healing by increasing the fibrous tissue, our present data suggest that this re-absorbable biomaterial diminishes the epidural scar formation, at least the first two weeks after laminectomy. This finding leads us to consider the use of fibrin glue over spinal duramater when it is likely that reoperation may become necessary in a short period of time after a laminectomy.

Intratumoural injection of autologous lymphocytes plus human lymphoblastoid interferon for the treatment of glioblastoma.

SummaryPreliminary experience with a clinical trial of immunotherapy for glioblastoma, by means of intratumoural injection of autologous lymphocytes (AL) mixed with low doses of human lymphoblastoid interferon (HLI) is presented.In two of twelve patients, a transient reduction of tumoural volume was obtained. Morphological studies showed that injected lymphocytes remain within the tumour, and suggest tumoural lysis due to activity of natural killer (NK) cells.Clinically no significant prolongation of survival time could be achieved and, as in other series, patients with additional radiation therapy survived longer. But the morphological findings suggest that immunotherapy carrying NK-cells to contact with tumoural cells might be useful in some patients with glioblastoma. Actually no explanation can be given why only two of our cases responded positively. Regarding the otherwise poor prognosis it seems justified to continue these studies.

Experimental induction of primitive neuro-ectodermal tumours in rats : a re-appraisement of the ENU-model of neurocarcinogenesis

SummaryA series of 122 experimental brain tumours, induced in the Wistar rat by means of prenatal exposition to ethyl-nitrosourea, were studied with histological, immunohistochemical and ultrastructural techniques. Although with conventional histological techniques, most of the induced tumours showed morphological features suggesting their classification as malignant schwannomas or oligodendroglioma-like neoplasms, their study by means of immunohistochemistry and electron microscopy suggested that they are, in fact, primitive neuroectodermal tumours, with a tendency toward neuronal differentiation. This finding obliges us to re-appraise the ethyl-nitrosourea model of neurocarcinogenesis and to consider its possible usefulness for the experimental study of therapeutic approaches with potential applications in human neuro-ectodermal neoplasms.

Expression and significance of vascular permeability factor in tumour infiltrating lymphocytes of brain metastases.

Summary Background. Recently, vasogenic edema has been related to the expression of vascular permeability factor (VPF) by tumour cells in brain metastases. On the other hand, expression of VPF has been reported in inflammatory cells. Keeping in mind the current presence of tumour-infiltrating lymphocytes (TIL) in brain metastases, our objective is to study the expression and significance of VPF in TIL-cells from specimens of brain metastases. Method. Tumour samples from 16 brain metastases associated with peritumoural edema were immunohistochemically studied for demonstration of VPF. The degree of VPF-expression by tumour cells and TIL was determined, and correlated with the degree of peritumoural edema. Findings. Our present results show that, independently of the VPF-positivity expressed by the tumour cells, VPF-expression is a constant finding in TIL-cells of brain metastases, and correlated with the amount of peritumoural edema. Interpretation. Our present findings suggest a role for TIL-cells in the development of vasogenic edema associated with brain metastases.

Imbalance between apostain expression and proliferative index can predict survival in primary glioblastoma.

Summary.Summary. Background: Cell proliferation and cell death are opposing processes in tumour growth, with tumour progression reflecting the balance between proliferating and apoptotic cells. The purpose of the present study is to verify the hypothesis that an imbalance between apoptosis and proliferation can predict survival in patients with primary glioblastoma. Methods: After the immunohistochemical study of Apostain and MIB-1 expression, the index of apoptosis (AI), the index of proliferation (PI), and the ratio AI/PI was recorded for each tumour specimen, in a series of 32 primary glioblastomas. Studies of correlation between AI and PI, between AI and survival, between PI and survival, and between the ratio AI/PI and survival, were performed using the Spearman rank correlation test. Furthermore, a comparative study of survival was performed for subgroups of patients with ratio AI/PI greater or lesser than 1, using the log rank test. Findings: In the present series, values of AI and PI showed a wide distribution, with a mean±SD of 8.16±7.2, and of 12.69±21.1, respectively. The values for the ratio AI/PI ranged between 0.01 and 6.03 (mean±SD: 1.44±1.60). Statistical study failed to obtain correlation between AI and PI. Survival of patients not correlated with AI neither with PI. The ratio between AI and PI did not correlate with survival either. Nevertheless, when survival for the subgroups of patients showing a ratio AI/PI greater or lesser than 1 was compared, a significant difference was found (p: 0.02). Survival ranged between 50 and 81 weeks (mean of 58.5±11.05 weeks) for the 12 cases showing a ratio AI/PI greater than 1, and it ranged between 8 and 85 weeks (mean: 38.20±25.37 weeks) for the 20 cases showing a ratio AI/PI lesser than 1. Interpretation: Our present results suggest that a clear imbalance between cell proliferation and apoptosis can predict outcome in patients operated on for a primary glioblastoma.

Precocious puberty and hypothalamic hamartoma. Report on a new case with ultrastructural data.

SummaryA new case of hypothalamic hamartoma associated with precocious puberty is presented. After reviewing the literature, 23 other cases appeared. The ultrastructural study of the present case revealed common features with other hamartomatous lesions of the central nervous system and with the gangliogliomas. The data suggest that these lesions are morphologically organized in a very similar manner despite their very different growing potential.

Delayed transplantation of foetal cerebral tissue into injured spinal cord of adult rats

SummaryDelayed transplantation of foetal cerebral tissue into injured spinal cord of adult rats was performed for the purpose of evaluating the usefulness of the procedure for reconstructing the spinal cord and providing motor recovery. Transplanted tissue showed a survival rate greater than 80% and integration with the host tissue. Nerve fibers of the host surrounded the transplanted tissue, penetrating it. Foetal cerebral neurons matured into recipient spinal cord, but they were not organized in layers. The experience obtained suggests that delayed transplantation of foetal cerebral tissue into contused spinal cord is useful in morphological spinal cord reconstruction. Nevertheless, at least during the first two months after transplantation, clinical assessment of motor recovery showed no differences between transplanted and nontransplanted rats.

Gangliosides modulate the growth rate and cell phenotype of a murine primitive neuro-ectodermal tumour

SummaryIntratumoural administration of gangliosides (GSD) into a murine primitive neuro-ectodermal tumour, growing in the epicranial subcutaneous tissue of syngenic rats, results in a decrease in the tumour growth rate and causes a more differentiated phenotype of tumour cell, with immunohistochemical expression of neuronal markers. These findings suggest that the potential usefulness of intralesional administration of GSD for the control of tumours of primitive neuro-epithelial character could be considered.

Tissue damage after chronic cerebellar stimulation in man

SummaryTwo spastic patients undergoing chronic cerebellar stimulation are studied. Biopsies taken after three months of stimulation showed various tissue changes when compared with those taken at the moment of electrode implantation. The most important alterations in the cerebellar cortex were adhesions round the electrodes, with a scarring reaction, gliosis, and loss of Purkinje cells. These findings resemble those described in various experimental reports of chronic cerebellar stimulation.

Long-term morphology of the alumina cream experimental epileptogenic focus

SummaryA morphological study of an experimental epileptogenic focus in the cat, eighteen months after intracerebral injection of alumina cream, is presented.The most significant histological findings were cortical atrophy and reactive gliosis enclosing the implanted particles. Subpial sclerosis and evidence of ischaemic neuronal lesions were also found.These findings confirm a close morphological relation between the alumina cream experimental focus obtained after a certain period of evolution and the human epileptogenic focus.