Embolization of tumor cells is rare in patients with systemic cancer and cerebral large vessel occlusion.

BACKGROUND AND PURPOSE: Stroke is a dreaded complication in patients with cancer. Besides paraneoplastic coagulopathy, chemotherapy, radiotherapy and tumor-directed invasive procedures, circulating cancer cells may contribute to thrombus formation and embolic stroke. However, the incidence of tumor cells within the blood clots of cancer patients with stroke is unknown and the role of circulating tumor cells in the formation of cerebrovascular thrombi remains unclear. METHODS: All patients who had undergone cerebrovascular thrombectomy at the University Hospital Zurich between 2014 and 2017 were screened for history of cancer. Clinical information was retrieved from the local stroke registry and the electronic charts and thrombi underwent a thorough histopathological re-review. RESULTS: Thirty-two of 182 patients (18%) with thrombectomy had a history of cancer. The majority of patients had advanced stage cancer. However, even after extensive histopathological re-review, only one specimen revealed tumor cells in the thrombus: a 75-year-old patient with acute occlusion of the middle cerebral artery who had been diagnosed with non-small-cell lung cancer 8.1 months prior to stroke. CONCLUSIONS: The presence of cancer cells in clots from cerebrovascular thrombectomy, indicative of a direct involvement of circulating tumor cells in the causation of stroke, is rare.

Bevacizumab may improve quality of life, but not overall survival in glioblastoma: an epidemiological study.

Background: The vascular endothelial growth factor antibody bevacizumab (Avastin®), received approval for the treatment of recurrent glioblastoma in many countries including the USA and Switzerland, but not the European Union, in 2009. Here, we explored the hypothesis that the approval of bevacizumab improved outcome with glioblastoma on a population level. Patients and methods: The prognostic significance of epidemiological, molecular genetic, and clinical data including treatment for glioblastoma patients diagnosed from 2010 to 2014 in the Canton of Zurich, Switzerland, was retrospectively analyzed using log-rank test and Cox proportional hazards models. Data were compared with data for the years 2005-2009. Results: In total, 310 glioblastoma patients were identified in the years 2010-2014. Median overall survival was 13.5 months for patients with known isocitrate dehydrogenase (IDH) wild-type (wt) (IDH1R132H-non-mutant) tumors (N = 248), compared with 11.3 months for IDH wt patients (P = 0.761) before (2005-2009). In the IDH wt cohort, bevacizumab use at any time increased from 19% in 2005-2009 to 49% in 2010-2014. Multivariate analysis did not identify bevacizumab exposure at any time to be associated with survival. Yet, upon the second-line treatment, baseline doses of corticosteroids were reduced by more than half in 83% of patients on bevacizumab compared with 48% of the patients treated with bevacizumab-free regimens (P = 0.007). Conclusion: This epidemiological study of a small, but clinically well-annotated patient cohort fails to support the assumption that the strong increase of bevacizumab use since 2010 improved survival in glioblastoma although clinical benefit associated with decreased steroid use may have been achieved.

Bevacizumab plus hypofractionated radiotherapy versus radiotherapy alone in elderly patients with glioblastoma: the randomized, open-label, phase II ARTE trial.

Background: The addition of bevacizumab to temozolomide-based chemoradiotherapy (TMZ/RT â†’ TMZ) did not prolong overall survival (OS) in patients with newly diagnosed glioblastoma in phase III trials. Elderly and frail patients are underrepresented in clinical trials, but early reports suggested preferential benefit in this population. Patients and methods: ARTE was a 2 : 1 randomized, multi-center, open-label, non-comparative phase II trial of hypofractionated RT (40 Gy in 15 fractions) with bevacizumab (10 mg/kg×14 days) (arm A, N = 50) or without bevacizumab (arm B, N = 25) in patients with newly diagnosed glioblastoma aged ≥65 years. The primary objective was to obtain evidence for prolongation of median OS by the addition of bevacizumab to RT. Response was assessed by RANO criteria. Quality of life (QoL) was monitored by the EORTC QLQ-C30/BN20 modules. Exploratory studies included molecular subtyping by 450k whole methylome and gene expression analyses. Results: Median PFS was longer in arm A than in arm B (7.6 and 4.8 months, P = 0.003), but OS was similar (12.1 and 12.2 months, P = 0.77). Clinical deterioration was delayed and more patients came off steroids in arm A. Prolonged PFS in arm A was confined to tumors with the receptor tyrosine kinase (RTK) I methylation subtype (HR 0.25, P = 0.014) and proneural gene expression (HR 0.29, P = 0.025). In a Cox model of OS controlling for established prognostic factors, associations with more favorable outcome were identified for age <70 years (HR 0.52, P = 0.018) and Karnofsky performance score 90%-100% (HR 0.51, P = 0.026). Including molecular subtypes into that model identified an association of the RTK II gene methylation subtype with inferior OS (HR 1.73, P = 0.076). Conclusion: Efficacy outcomes and exploratory analyses of ARTE do not support the hypothesis that the addition of bevacizumab to RT generally prolongs survival in elderly glioblastoma patients. Molecular biomarkers may identify patients with preferential benefit from bevacizumab. Clinical trial registration number: NCT01443676.

Uncommon case of brain metastasis in a patient with a history of heavy smoking.

Primary sarcomas of the aorta are extremely uncommon. Depending on histomorphology and immunohistochemical pattern, intimal sarcomas can show angiosarcomatous differentiation. Here, we describe the case of a 60-year-old woman with a primary intimal sarcoma of the aortic arch and signs of cerebral metastatic disease as the initial manifestation. After the patient experienced the onset of severe headaches, ataxia, and left-sided weakness, magnetic resonance imaging showed several brain lesions. Histologic assessment of a brain biopsy specimen revealed a malignant tumour composed of large pleomorphic cells that were positive for pancytokeratin and CD10. Radiation to the brain did not significantly improve the patient's symptoms, and cranial computed tomography (ct) imaging revealed several metastases, indicating lack of response. Because of the patient's smoking history, the presence of central nervous system and skeletal metastases on combined positron-emission tomography and ct imaging, and the focal pan-cytokeratin positivity of the tumour, carcinoma of the lung was favoured as the primary tumour. Despite chemotherapy with cisplatin and etoposide, the patient's neurologic symptoms and general condition deteriorated rapidly, and she died within a few days. At autopsy, an undifferentiated intimal sarcoma of the aortic arch was diagnosed. The primary tumour in the aorta consisted of large pleomorphic cells. Immunohistochemical analysis of the aortic tumour and brain metastases demonstrated diffuse positivity for vimentin and p53 and focal S-100 staining. In summary, we report a challenging case of advanced intimal sarcoma of the aortic arch with brain and bone metastases at initial presentation. Our report demonstrates the difficulties in diagnosing and treating this disease, and the need for multicentre studies to accrue more patients for investigations of optimal therapy.

Mouse tumor model for neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder characterized by increased incidence of benign and malignant tumors of neural crest origin. Mutations that activate the protooncogene ras, such as loss of Nf1, cooperate with inactivating mutations at the p53 tumor suppressor gene during malignant transformation. One hundred percent of mice harboring null Nf1 and p53 alleles in cis synergize to develop soft tissue sarcomas between 3 and 7 months of age. These sarcomas exhibit loss of heterozygosity at both gene loci and express phenotypic traits characteristic of neural crest derivatives and human NF1 malignancies.

Occult leptomeningeal large cell medulloblastoma in an adult.

OBJECTIVE AND IMPORTANCE: Large cell medulloblastoma is an uncommon malignancy of childhood that often pursues an aggressive clinical course. We report the first case of this entity in an adult that proved to be an unsuspected primary leptomeningeal tumor. CLINICAL PRESENTATION: A 30-year-old man complained of worsening neck pain over the course of 3 months. Neck pain increased a few days prior to admission and a cervical spine CT revealed tonsillar herniation. Cervical spine MRI performed the day prior to admission confirmed the diagnosis of Chiari I malformation and C3-4 disk herniation without spinal cord compression. On the day of admission, the patient became unresponsive and resuscitative measures were unsuccessful. Postmortem examination of the brain was notable for necrotic cerebellar tonsils, but demonstrated no evidence of an intraparenchymal mass lesion. Microscopic examination of the cerebellum revealed discohesive neoplastic cells, which showed characteristic dot-like immunoreactivity for synaptophysin, diagnostic of large cell medulloblastoma within the subarachnoid space. CONCLUSIONS: Our experience with this unique case illustrates the challenges of diagnosing a primary leptomeningeal neoplasm. This case also underscores the importance of maintaining a high degree of suspicion for leptomeningeal neoplasms in patients who present with imaging studies suspicious for Chiari I malformation.

Congenital ependymoblastoma arising in the sacrococcygeal soft tissue: a case study.

Ependymoblastomas are distinct embryonal tumors of the central nervous system reported only rarely in the literature. Most examples arise in young children under the age of 2 years, in the supratentorial compartment, and may or may not be related to the ventricular system. We report the case of a one-day-old infant who presented with a 6.4 x 5.6 x 3.5 cm ruptured buttock mass. Ultrasound demonstrated a solid mass at the base of the spine that displaced the bladder anteriorly with resultant hydronephrosis. Magnetic resonance images confirmed the presence of a solid mass surrounding the lower sacrum with an internal component partially encircling and deviating the rectum. Histopathological evaluation confirmed the diagnosis of ependymoblastoma. Of note, immunohistochemical analysis revealed diffuse staining with vimentin and patchy expression of synaptophysin, glial fibrillary acidic protein, neurofilament proteins, neuron-specific enolase, CD99 and nestin. On the 42nd day of life, chemotherapy was initiated with a modified Children's Oncology Group (COG) AGCT-01P1 (cyclophosphamide, cisplatin, 70% etoposide, no bleomycin) regimen. The authors describe their experience and review the literature, emphasizing that ependymoblastomas should be considered in the differential diagnosis of sacral masses in the newborn.

Rare primary CNS anaplastic large cell lymphoma in an immunocompetent adult: a clinical-pathologic case report and review case of the literature.

OBJECTIVE AND IMPORTANCE: Isolated anaplastic large cell lymphoma (ALCL) presenting in the primary central nervous system is distinctly uncommon. The authors describe a case that clinically and radiographically simulated a primary glial neoplasm. CLINICAL PRESENTATION: A 39-year-old immunocompetent male presented with seizures and a rapidly enlarging right occipital/parietal lesion. Magnetic resonance images demonstrated a right occipitoparietal lesion, hypodense on T1WI, with patchy contrast enhancement with gadolinium and significant white matter edema pattern on T2WI along with mass effect and midline shift. INTERVENTION: The patient underwent a frameless stereotactic assisted needle biopsy. There appeared to be a clear demarcation between white matter and tumor with no obvious necrosis. Biopsy showed a proliferation of single cells and poorly cohesive groups of cells with large, pleomorphic nuclei, many containing prominent nucleoli, and a moderate amount of cytoplasm. Immunohistochemical staining revealed CD-30 and ALK-positivity typical of ALCL, a rare form of T-cell lymphoma. An extensive workup revealed neither systemic disease nor evidence of immunocompromise. CONCLUSION: Reported in less than 20 patients, primary ALCL in an immunocompetent patient is rarely found intracranially; however, its ability to mimic glial neoplasms as well as other pathologies underlines its importance.

The aryl hydrocarbon receptor links integrin signaling to the TGF-ß pathway.

Glioblastoma is the most common and aggressive form of intrinsic brain tumor. Transforming growth factor (TGF)-ß represents a central mediator of the malignant phenotype of these tumors by promoting invasiveness and angiogenesis, maintaining tumor cell stemness and inducing profound immunosuppression. Integrins, which are highly expressed in glioma cells, interact with the TGF-ß pathway. Furthermore, a link has been described between activity of the transcription factor aryl hydrocarbon receptor (AhR) and TGF-ß expression. Here we demonstrate that integrin inhibition, using αv, ß3 or ß5 neutralizing antibodies, RNA interference-mediated integrin gene silencing or pharmacological inhibition by the cyclic RGD peptide EMD 121974 (cilengitide) or the non-peptidic molecule GLPG0187, inhibits AhR activity. These effects are independent of cell detachment or cell density. While AhR mRNA expression was not affected by integrin inhibition, AhR total and nuclear protein levels were reduced, suggesting that integrin inhibition-mediated regulation of AhR may occur at a post-transcriptional level. AhR-null astrocytes, AhR-null hepatocytes or glioblastoma cells with a transiently silenced AhR gene showed reduced sensitivity to integrin inhibition-mediated alterations in TGF-ß signaling, indicating that AhR mediates integrin control of the TGF-ß pathway. Accordingly, there was a significant correlation of αv integrin levels with nuclear AhR and pSmad2 levels as determined by immunohistochemistry in human glioblastoma in vivo. In summary, this study identifies a signaling network comprising integrins, AhR and TGF-ß and validates integrin inhibition as a promising strategy not only to inhibit angiogenesis, but also to block AhR- and TGF-ß-controlled features of malignancy in human glioblastoma.

Effects of ectopic overexpression of p21(WAF1/CIP1) on aneuploidy and the malignant phenotype of human brain tumor cells.

p21WAF1/CIP1 is a downstream effector of the p53 tumor suppressor gene and a universal cyclin-dependent kinase (CDK) inhibitor. To determine the ability of p21WAF1/CIP1 to function as a tumor suppressor, we constructed a replication-defective adenovirus vector containing p21WAF1/CIP1 (Adp21WAF1/CIP1) to effect ectopic overexpression in a p53-defective human astrocytoma cell line, U-373MG. We observed a marked decrease in CDC2 and CDK2 kinase activity associated with a corresponding decrease in the amount of CDC2 but not CDK2 protein; a decreased growth potential of Adp21WAF1/CIP1-infected cells demonstrated by diminished [3H]thymidine incorporation, increased cell doubling time and G1-arrested cell cycle; an association between Adp21WAF1/CIP1-infected cells and inhibition of aneuploid cell accumulation; and an alteration of the malignant phenotype of cells was evidenced by the loss of anchorage-independent growth in soft agar and the failure to induce tumorigenesis in both peripheral and intracerebral xenograft models, including the prevention of tumor formation Adp21WAF1/CIP1 infection 2 days post tumor cell implantation. Adp21WAF1/CIP1. Adp21WAF1/CIP1 appears to be a strong candidate for gene therapy studies based on these studies indicating that Adp21WAF1/CIP1 inhibits proliferation, tumorigenicity and aneuploidy in human brain tumor cells.

Relationship between radiation injury and Alzheimer-related neurodegenerative changes.

The relationship between radiation injury and other neurodegenerative changes such as the formation of neuritic or diffuse plaques and tangles have received little attention in the literature. In the current study, archival tissue was examined from 485 patients with the diagnosis of either a primary or metastatic brain tumor, who had received radiation therapy between the initial and subsequent pathological study (either surgical or autopsy). Of those cases, 20 were identified that also contained cerebral cortex in both specimens. Sections were stained with the modified Bielschowsky technique and immunohistochemical preparations for beta-amyloid. Contrary to previous reports, the present study did not identify neurodegenerative changes typical of Alzheimer's disease as a consequence of radiation therapy.

Chromogenic in situ hybridization accurately identifies EGFR amplification in small cell glioblastoma multiforme, a common subtype of primary GBM.

Primary glioblastoma multiforme (GBM) commonly overexpresses the epidermal growth factor receptor (EGFR) gene and its ligand-independent mutant, EGFRvIII. Amplification of the EGFR gene has been implicated in the pathogenesis of primary GBM, in particular the small cell phenotype, and this finding may contribute to its aggressive clinical behavior. Anti-EGFR clinical trials for GBM are being conducted, and it would be useful to identify a rapid technique to determine whether EGFR expression and the small cell phenotype are associated with a response to therapy. In the present study we examined 56 cases of GBM using chromogenic in situ hybridization (CISH). CISH analysis and morphology identified 22 small cell (SCGBM) and 22 non-small cell glioblastoma (NSCGBM), and 12 cases of a mixed phenotype. Fourteen cases of SCGBM (14/22) showed EGFR amplification, while only 5 NSCGBM (5/22) cases showed amplification. We have therefore used CISH as an efficient, economic and reliable means for routinely assessing EGFR amplification in GBM, including the small cell variant.

Alpha-synuclein expression in central nervous system tumors showing neuronal or mixed neuronal/glial differentiation.

Alpha-synuclein (alpha-synuclein) is a member of a family of cytoplasmic proteins found predominantly and abundantly in the brain, and concentrated in pre-synaptic nerve terminals, near vesicles. We hypothesized that an antibody to alpha-synuclein could be a useful marker of neuronal differentiation in central nervous system (CNS) tumors. Twenty tumors known to have neuronal or mixed neuronal/glial differentiation ( 11 gangliogliomas, 2 anaplastic gangliogliomas, 5 gangliocytomas, and 2 ganglioneuroblastomas), 5 central neurocytomas, and 1 dysembryoplastic neuroepithelial tumor (DNET) were immunostained with a mouse monoclonal antibody raised against human alpha-synuclein. Intense cytoplasmic staining, in some instances extending into the perikarya, was seen in 6 of 11 gangliogliomas, 2 of 2 anaplastic gangliogliomas, and 2 of 2 ganglioneuroblastomas. Alpha-synuclein-positive cells were usually large in size, resembled dysmorphic neurons, and were variably immunoreactive for anti-neurofilament and/or anti-synaptophysin antibodies. In contrast, central neurocytomas, gangliocytomas, and the DNET were negative for cytoplasmic alpha-synuclein expression. Our findings indicate that alpha-synuclein is expressed within the neuronal component of mixed tumors of the CNS displaying more than 1 histophenotype, and/or showing different degrees of anaplasia. Based on currently available data, we conclude that cytoplasmic alpha-synuclein expression is a marker of maturing neurons in these tumors.

Glial tumors in the MNU rat model: induction of pure and mixed gliomas that do not require typical missense mutations of p53.

Gliomas were induced in adult male Sprague-Dawley rats by continuous exposure to 100 ppm of N-nitrosmethylurea (MNU) in drinking water. Latency periods for such tumors were 20 and 50 weeks following completion of exposure intervals of 20, 15, and 10 weeks, respectively. Based on histomorphology and the pattern of GFAP immunoreactivity, a large percentage of MNU-induced tumors (>40%) were anaplastic mixed gliomas, having both neoplastic astrocytic and oligodendroglial components. Typical oligodendrogliomas and astrocytomas also occurred less frequently. Unlike the majority of tumors induced by ethylnitrosourea (ENU), MNU yielded glial tumors that did not express synaptophysin. Anaplastic mixed gliomas and glioblastoma multiforme (GBMs) had no missense p53 mutations in the commonly mutated exons 4 through 8 and did not overexpress wild-type p53, suggesting that MNU-induced oncogenesis in rat brain tumors may not require inactivation/alteration of the p53 tumor suppressor gene. The K-ras gene was also analyzed and found to have no activating mutations in brain tumors. This model is suitable for studying genetic events leading to the majority of gliomas that apparently express functional p53.

Expression of telomerase RNA component correlates with the MIB-1 proliferation index in ependymomas.

Although there is general agreement that certain morphologic subtypes of ependymoma are benign, the biologic behavior of other ependymal neoplasms is poorly understood and not clearly related to conventional histopathologic criteria. The absence of universally accepted standards has prompted the search for more objective biologic markers. Telomerase is an RNA-containing enzyme associated with immortality in proliferating stem cells and many tumors. We investigated the proliferative activity of 26 ependymomas as determined by MIB-1 immunolabeling and compared the results with the in situ expression of human telomerase RNA (hTR) and WHO tumor grade. The study included 9 WHO grade I ependymomas (6 subependymomas and 3 myxopapillary ependymomas), 13 WHO grade II ependymomas, and 4 anaplastic (WHO grade III) ependymomas. The proliferation index (PI) and telomerase RNA expression were significantly increased in grade III ependymomas (p < 0.0001 for PI and p = 0.0015 for hTR). In these tumors, the PI and hTR expression were highly correlated (p = 0.0001). Of note, a single case designated grade II showed both increased proliferative activity and the highest hTR expression detected in this series of ependymal neoplasms. Our results suggest that the PI and hTR expression may be important biologic markers, independent of other histopathologic criteria of tumor grade. Future studies examining the correlation of MIB-1 cell kinetics and hTR expression with clinical parameters in selected ependymoma subtypes are needed to determine the prognostic relevance of these markers.

Human telomerase RNA expression and MIB-1 (Ki-67) proliferation index distinguish hemangioblastomas from metastatic renal cell carcinomas.

Hemangioblastomas are low-grade, capillary rich neoplasms of the cerebellum and spinal cord that can occur sporadically or in the setting of Von Hippel-Lindau syndrome. The present study analyzed the utility of proliferation potential in differentiating hemangioblastoma from RCC metastatic to the central nervous system using a MIB-1 (Ki-67) labeling index and assessment of expression of the RNA component of telomerase. Immunohistochemical analysis for epithelial membrane antigen (EMA) and MIB-1 was performed on paraffin-embedded sections of 27 hemangioblastomas and 5 RCC metastatic to the central nervous system. All but one hemangioblastoma demonstrated low or negative MIB-1 immunoreactivity, while 4 of 5 RCC metastases had moderate or high labeling indices. Telomerase RNA expression was assessed in 10 hemangioblastomas and in all 5 metastatic RCC by in Situ hybridization. All 10 hemangioblastomas demonstrated a lack of expression of telomerase RNA, while all 5 metastatic RCCs showed moderate to strong expression. Our results suggest that the MIB-1 labeling index is useful in differentiating hemangioblastoma from metastatic RCC and assessment of telomerase expression can also provide novel information on the difference in growth potential of these tumors.

Chronic hypotensive effects of verapamil in angiotensin hypertension are steroid independent.

This study was designed to examine the mechanisms that contribute to the chronic hypotensive effects of verapamil during angiotensin II-induced hypertension. Hypertension was induced in five dogs by continuous intravenous infusion of angiotensin II (5 ng/kg/min) for 17 days. On the sixth day of angiotensin II infusion when daily sodium balance was achieved, mean arterial pressure (control, 92 +/- 4 mm Hg), plasma aldosterone concentration (control, 5.2 +/- 0.9 ng/dl), and renal resistance (control, 0.28 +/- 0.01 mm Hg/ml/min) were increased 37 +/- 8 mm Hg, 13.6 +/- 5.0 ng/dl, and 0.20 +/- 0.05 mm Hg/ml/min, respectively. At this time there were no significant changes in glomerular filtration rate, effective renal plasma flow, net sodium and water balance, or extracellular fluid volume. Subsequently, when verapamil was infused (at 2 micrograms/kg/min) simultaneously with angiotensin II (days 7-13), there was a net loss of 55 +/- 10 meq sodium, a 7.0 +/- 0.7% fall in extracellular fluid volume, and approximately a 70% reduction in the chronic effects of angiotensin II on mean arterial pressure and renal resistance; in contrast, verapamil failed to attenuate the long-term aldosterone response to angiotensin II. Further, although glomerular filtration rate and effective renal plasma flow tended to increase during verapamil administration, there were no consistent chronic long-term changes in these renal indexes. In comparison with these responses in hypertensive dogs, when verapamil was infused for 7 days before the induction of angiotensin II hypertension, there were no significant changes in any measurements except mean arterial pressure, which fell 11 +/- 1 mm Hg. Thus, these data fail to support the hypothesis that the chronic stimulatory actions of angiotensin II on aldosterone secretion are dependent on a sustained increase in transmembranal calcium influx. Moreover, these data indicate that the pronounced long-term hypotensive effects of verapamil in angiotensin II hypertension are due to impairment of the direct renal actions of angiotensin II rather than the indirect sodium-retaining effects that are mediated via aldosterone secretion.

Characterization of initiated cells in N-methylnitrosourea-induced carcinogenesis of the CNS in the adult rat.

Glial tumors may originate from the malignant transformation of multipotent glial progenitor cells, but tools to study malignant transformation leading to gliomas are limited by the lack of biological systems that represent early stages of this disease in adult animals. In order to characterize the initiated cells that give rise to gliomas, we have employed the N-methylnitrosourea (MNU) model for induction of brain tumors in adult rats (Rushing et al., 1998). Specifically, we have isolated and cultured transformed (premalignant) cells from normal-appearing brains of rats exposed to MNU for 10 weeks and from histologically abnormal brains of rats exposed to MNU for 15 weeks. We compared them with cells cultured from control animals under identical conditions. Cultured cells were classified according to their morphology, immunophenotype, karyotype, proliferation capacity, and tumorigenicity in athymic mice. Cultures from untreated normal rat brains grew as monolayers and had normal karyotypes (42 X,Y), epithelioid morphology, and slow proliferative capacity (doubling time > 120 h). In contrast, cultured cells from brains of MNU-exposed animals had karyotypes that ranged from normal to highly aneuploid. Aneuploid lines grew rapidly in multilayers (doubling time < 24 h), had differentiated astrocytic or oligodendroglial morphology and immunohistochemical staining profile, and yielded tumors in athymic mice. Initiated cells with minor chromosomal aberrations assumed mixed bipolar or tripolar morphologies in high density cultures, proliferated rapidly, but showed contact inhibition and failed to induce tumors when injected s.c. in athymic mice. In general, lines showing no evidence of chromosomal aberrations had the most epithelioid morphology, proliferated slowly (doubling time > 72 h), and retained strict contact growth inhibition. The presumed undifferentiated glial progenitor cells in culture from either control or MNU-treated rats variably expressed markers such as vimentin, nestin, and NG2 proteoglycan, and they weakly expressed the mature astrocytic or oligodendroglial markers glial fibrillary acidic protein or galactocerbroside, respectively. These cultures differentiated to bipolar-tripolar morphology with concomitant maturation to a GFAP+ or GalC+ phenotype upon exposure to secondary messengers such as dibutyryl-cyclic-AMP and/or growth factors such as basic fibrillary growth factor. Continuous stimulation with these messengers resulted in terminal differentiation and consequent death upon withdrawal of the stimulus. These results provide information that could lead to detailed characterization of initiated, premalignant cells in the adult brain and to a better understanding of glial carcinogenesis.

Tumors of pineal parenchymal cells: a correlation of histological features, including nucleolar organizer regions, with survival in 35 cases.

We studied 35 parenchymal neoplasms arising in the pineal gland, including 11 pineoblastomas, 21 pineocytomas, and three mixed pineocytoma-pineoblastomas. Pineoblastomas were most commonly found in children (mean age, 12.6 years). The median postsurgical length of survival for seven patients, including five with remote metastases, with fatal outcome was 24 months. The 21 pineocytomas were found in older individuals (mean age, 26.8 years). Four patients with pineocytoma died; two before surgery and two in the immediate postoperative period. The remaining 17 patients survived for intervals between 6 and 118 months after surgery. Two mixed pineocytoma-pineoblastomas were found in infants who died a few months after biopsy, whereas a third patient, an adult, was alive at 46 months after excision and irradiation. Both pineoblastoma and pineocytoma exhibited variable immunoreactivity to neurofilament proteins, synaptophysin, glial fibrillary acidic protein, S-100 protein, retinal-S antigen, and rhodopsin; the highest percentages of positive cells stained with synaptophysin. Three pineocytomas exhibited ganglionic differentiation and two of them also showed a glial component. Prognosis could not be correlated with the degree of divergent differentiation. Comparison of silver-stained nucleolar organizer region (AgNOR) counts between pineoblastomas and pineocytomas suggests that the former are more actively proliferative than the latter, with mixed pineocytoma-pineoblastoma showing intermediate activity. There was no correlation between AgNOR score and prognosis within the three tumor groups.

Precipitins to an aflatoxin-producing strain of Aspergillus flavus in patients with malignancy.

Serum samples from 121 patients in whom malignant disease had been diagnosed, were assayed for precipitins to fungal isolates from leukemia-associated environments. Control sera were from age-, sex-, and race-matched patients with no history of malignant disease. Sera from 36 (30%) malignancy patients and seven (6%) controls yielded a precipitin band to an aflatoxin-producing Aspergillus flavus isolate from a leukemia-associated house (x2 = 222, p less than 0.05%). No significant numbers of precipitins were obtained to either of the other fungal isolates from that and another such house. Although A. fumigatus has frequently been incriminated as a source of infection in patients with malignancy, only 9% of malignancy patients had a precipitin response to it, as did 1.6% of controls. Also, the presence of the precipitins to A. flavus was not connected with past radiation or immunosuppressive therapy. However, among patients with precipitins to A. fumigatus there was a higher death rate in the year following the study. Precipitins to A. flavus may be related to heavy environmental exposure possibly leading to aflatoxin exposure which may contribute to development of malignancy though immunosuppressive effects.