摘要:

&NA;The failure of most available treatment modalities to improve the survival time and the quality of survival in patients with gliomas calls for the intense biological analysis of glial neoplasia. The untimely activation of cellular proto‐oncogenes is often related to the process of neoplasia. Several protein growth factors as well as their cellular receptors have been identified as products of proto‐oncogenes. Furthermore, these growth factors have been identified as glial mitogens in normal glial cell cultures as well as in tumors. The analysis of growth factor biology gains additional weight by the demonstration of autocrine growth factor secretion by tumor cells. The role of epidermal growth factor (EGF) and its receptor system in glial cell proliferation and differentiation is presented, with the speculation that the EGF receptor system may integrate the biological actions of many different factors, of which EGF itself may be least important. The literature on platelet‐derived growth factor and insulin‐like growth factors is reviewed, and the biology of fibroblast growth factor is presented in perspective with such phenomena as neovascularization and cell‐matrix interactions. (Neurosurgery25:681‐694, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;Although hemangioblastomas are regarded as benign neoplasms, they may recur in up to 25% of cases. The clinico‐pathological correlates of this more aggressive behavior have not been identified. Among 26 patients with hemangioblastomas who had been evaluated and treated at the Massachusetts General Hospital between 1974 and 1986, 7 (27%) developed recurrences after surgical extirpation. Recurrence was correlated with younger age, that is <30 years at the time of diagnosis (P< 0.01), von Hippel‐Lindau syndrome (P< 0.001), and the presence of multicentric tumors of the central nervous system at initial diagnosis (P< 0.005). Histopathologically, recurring hemangioblastomas had lower frequencies of cyst formation (P= 0.10) and lower proportions of lipid‐laden stromal cells (P< 0.05). The findings suggest that a particular constellation of clinical and pathological features can be used to predict the likelihood of recurrence of a hemangioblastoma, and therefore to identify patients in need of long‐term follow‐up or, possibly, adjunctive therapy. (Neurosurgery25:695‐698, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;The cases of 18 patients operated on for hemangioblastoma of the spinal cord were reviewed. There were 11 men and 7 women. (M:F = 1.6:1) and in 15 patients, the onset of spinal symptoms was before the age of 40 years. There were 19 intradural and 2 extradural tumors. The tumor was accompanied by a cyst in 9 patients (50%). There were 6 cases of Lindau's disease, including 3 cases of multiple spinal tumors. Symptoms improved postoperatively in 13 patients, were unchanged in 2, and were aggravated in 3. At the present time, magnetic resonance imaging with gadolinium‐diethylene‐triamine‐pentaacetic acid (Gd‐DTPA) enhancement is the most useful tool for precise localization of the tumor and differentiation of any accompanying cyst. (Neurosurgery25:699‐708, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;Using KHT tumor in a mouse metastatic tumor model. we examined the effect of intracerebral and/or intraperitoneal injections ofCorynebacterium parvumon the growth of metastatic brain tumor and the development of an inflammatory response in the central nervous system (CNS).C. parvumgiven intraperitoneally had no effect on the development and growth of CNS tumor, but did prolong the survival of mice by inhibiting the growth of systemic metastatic tumor, which was the cause of death in our tumor model. Mice that received intracerebral injections ofC. parvumexhibited significantly decreased growth of metastatic brain tumor, as compared with mice that received intracerebral injections of saline, whether or not they had receivedC. parvumintraperitoneally. In addition, the brains of mice that receivedC. parvumintracerebrally exhibited an inflammatory response that was minimal or absent in the brains of control mice. Our results suggest that if immunotherapeutic agents can be delivered to the CNS and cause an inflammatory response. they can be effective against CNS metastases. (Neurosurgery25:709‐714, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;The application of a monoclonal antibody to bromodeoxyuridine (BUdR) provides a rapid, reproducible, nontoxic, immunohistochemical method to measure cellular kinetics of intracerebral tumor angiogenesis. The rabbit brain tumor model of angiogenesis consists of tumor and endothelial cell populations with high proliferative rates that demonstrate the close interdependence between microvascular and neoplastic growths as well as topographic gradients, heterogeneity, and regional microdomains of cell proliferation. The labeling index (LI) of endothelial cells was 25.8% at the tumor periphery, compared to 1.7% in the tumor center (P< 0.001). Concomitant with an increased turnover of neoplastic cells at the tumor periphery, LI was 26.6% with a LI of 7.7% in the center (P< 0.01). Furthermore, labeled tumor cells tended to be organized around proliferating capillaries, with less DNA synthesis farther from the nearest blood vessel. The established normal microvessels of the brain, e.g., in the opposite tumor‐free hemisphere, were mitotically inactive with a LI of <0.001%. Quantitation of vascular cytokinetics should be useful in further studies of the pathophysiology of brain tumor angiogenesis and the development of pharmacological approaches directed toward the microvasculature. (Neurosurgery25:715‐719, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;Treatment of gliomas remains disappointing in spite of a great number of experimental biological data and of randomized therapeutic studies. This could be partly explained by the inefficiency of our conventional methods to assess the regional metabolism of these tumors. The use of positron emission tomography (PET) brings encouraging possibilities in this field. We report our preliminary experience of measuring regional cerebral methionine uptake with PET after intravenous injection of [11C]l‐methionine. Twenty‐two patients with histologically confirmed gliomas were studied. An ECAT II positron emission tomograph was used for scanning. The position of the plane was chosen to include a major section of the tumor in the reconstructed brain slice. The protocol required a two‐step examination: 1) after injection of 15 to 25 mCi of [11C]l‐methionine, 12 scans were performed over a period of 46 minutes; and 2) 18 hours later, regional cerebral blood volume was measured in the same slice after intravenous injection of 2 to 4 mCi of68GaCl3. The tumoral region of interest was determined as being the area of maximum activity. For each patient we calculated the ratio, R, between the activity in this tumor region of interest and the activity in the contralateral healthy symmetric region of interest which was used as an “internal standard” for the same patient. We correlated the ratio R with the histological grading. In 22 patients, mean values of R were calculated for each tumor: Grade II (n = 5): R = 1.04 ± 0.27; Grade III (n = 5): R = 1.68 ± 0.22; and Grade IV (n = 12): R= 2.33 ± 0.86. Correlations between hypermetabolism and grading are highly significant for Grades II/III (P= 0.0045) and II/IV (P= 0.00019), but not for Grades II/IV (P= 0.3141). We assessed the effects of radiotherapy: in 3 glioblastomas studied before and after radiotherapy, a significant decrease of R was observed: from 2.84 ± 1.43 to 1.35 ± 0.05. In one Grade II glioma, there was no change. Last, we assessed the early effects of intra‐arterial chemotherapy: 8 patients were studied before and after the first course of treatment with an intracarotid injection of 1,3‐bis‐(2‐chloroethyl)‐l‐nitrosourea (BCNU). Early modifications of R were correlated with clinical evolution after completion of treatment (intracarotid BCNU every 6 weeks). Despite a patient in whom a dramatic decrease of R was followed by a long survival with normalization of the computed tomographic scan, no significant correlation could be displayed between modifications in R and the length of survival. This approach will have to be developed in future studies. (Neurosurgery25:720‐728, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;To determine the efficacy of early jejunal hyperalimentation as nutritional support in the head‐injured patient, 32 head‐injured patients with Glasgow Coma Scale scores less than 10 were studied for the first 7 days after injury. The experimental (E) group had nasojejunal feeding tubes placed fluoroscopically. Within 36 hours of injury, they received nutritional support equal to their measured resting energy expenditure. The control (C) group was fed gastrically when bowel sounds returned. There were no significant differences (P> 0.05) in age, Glasgow Coma Scale score, type of neurological injury, or associated injuries between the two groups. The mean resting energy expenditure, serum albumin, glucose, lymphocyte count, body weight, and total nitrogen loss were nearly identical for both groups. With the jejunal feedings, daily caloric (E = 2102 kcal versus C = 1100 kcal) and nitrogen intake (E = 11.1 g versus C = 5.6 g) and daily nitrogen balance (E = ‐4.3 g versus C = ‐11,8 g) improved. The incidence of bacterial infections (E = 3 versus C = 14) and days of intensive care unit hospitalization (E = 6 versus C = 10) were significantly reduced (P< .05). Headinjured patients will tolerate early jejunal hyperalimentation despite the presence of a clinically silent abdomen, and the cost and complications of total parenteral nutrition are avoided. The increased caloric and nitrogen intake and improved nitrogen retention markedly reduced infections and days of stay in the intensive care unit. (Neurosurgery25:729‐735, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;A right‐sided subarachnoid hemorrhage (SAH) was created in 12 monkeys. Only the right (clot‐side) cerebral arteries developed angiographic vasospasm (VSP), which was maximal 7 days after SAH. Eight animals were killed at this time and the remainder at 14 days. At the time of killing the middle cerebral arteries (MCAs) were harvested, and four normal, left (non‐clot‐side) MCAs were vasoconstricted in vitro with prostaglandin F2… All MCAs were studied with scanning and transmission electron microscopy. Right MCAs in maximal VSP 7 days from SAH were undistinguishable on scanning electron microscopy from normal arteries vasoconstricted in vitro: both groups demonstrated a mean 57% reduction in vessel caliber and a 5‐fold increase in vessel wall thickness compared to normal, nonvasoconstricted left MCAs. On transmission electron microscopy, however, arteries in SAH‐induced VSP showed degenerative changes in the tunica intima and media. These changes were still evident at 14 days. despite considerable resolution of VSP. These findings, as well as those from other pathological studies of animal and human cerebral arteries in VSP, suggest that the arterial narrowing and vessel wall thickening seen within several weeks of SAH is due primarily to medial contraction, but unlike simple vasoconstruction, is associated with degenerative ultrastructural changes in the endothelium and vascular smooth muscle cells which may denote a temporarily irreversible state. (Neurosurgery25:736‐746, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;The effects of mannitol on the cerebral microcirculation were studied using isolated perfused intracerebral (parenchymal) arterioles in rats. After vessels developed spontaneous tone, increasing concentrations of mannitol were applied extraluminally. Mannitol induced vasodilation in a dose‐dependent manner. In an initial series of vessels, a 2% mannitol solution produced a maximal increase of vessel diameter of 35.8 ± 2.2% (mean ± SEM: n = 5). The degree of vasodilation was comparable to that produced by a sucrose solution of nearly equal osmolarity, suggesting that mannitol produced nonspecific vasodilation by increasing osmolarity. Organ bath solution pH was varied to 6.8 and 7.6 from the control pH of 7.3 in order to examine the effects of mannitol on vessels with different degrees of vessel tone. The mannitol dose‐response curves in these vessels were parallel to each other, indicating that vasodilating effects of mannitol are essentially constant irrespective of the initial tone state of the vessel. In a second series of experiments, the effects of intraluminally applied mannitol on intracerebral arterioles were examined and compared to cxtraluminal application. Intraluminal application of 2% mannitol solutions produced a 42.6 ± 2.0% (n = 5) increase in vessel diameter, which was not significantly different from that produced by extraluminal application (42.5 ± 2.9%; n = 5;P= 0.89). Our results indicate that the direct action of mannitol on vascular smooth muscle in intracerebral arterioles is vasodilation. Our data do not necessarily conflict with the autoregulatory vasoconstriction theory for mannitol action because a relatively small osmolarity change after the intravenous infusion of mannitol in the usual dosage (1 g/kg) would be expected to have a modest effect on vascular diameter when compared with the autoregulatory vasoconstriction induced by decreased blood viscosity after mannitol infusion. (Neurosurgery25:747‐752, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

&NA;We examined vascular reactivity to various vasoconstrictors and dilators, and the changes in calcium‐calmodulin levels in canine basilar arteries after subarachnoid hemorrhage (SAH). Contractile responses to noradrenaline, serotonin, and potassium chloride were markedly attenuated at 48 hours (P< 0.05), and further attenuated at 7 and 14 days after SAH (P< 0.01). Dilation responses to calcium antagonist were maintained at 48 hours after SAH, but were markedly reduced at 7 and 14 days after SAH (P< 0.05). Transmission electron micrographs of the basilar artery showed contraction of the media between 48 hours and 7 days and degeneration of smooth muscle cells over the 7 days after SAH. Electron microscopic cytochemical examination for calcium showed that intracellular deposits of calcium pyroantimonate increased in smooth muscle cells of basilar arteries at 1 hour after the first intracisternal injection of blood (early spasm), but decreased in smooth muscle cells at 48 hours after SAH (at the beginning of delayed vasospasm). They decreased further in the vessels 7 days after SAH. The calmodulin contents in the basilar arteries were decreased slightly at 6 hours, and significantly (P< 0.05) at 48 hours after SAH, as determined by radioimmunoassay and phosphodiesterase assay. Therefore, it is considered that delayed vasospasm is not simply an active contraction of the vessels, but a functional or structural derangement of contractile elements of smooth muscle cells after 48 hours after SAH. (Neurosurgery25:753‐761, 1989)

ISSN:0148-396X    

出版商:OVID    

年代:1989

数据来源: OVID