Autosomal dominant parkinsonism associated with variable synuclein and tau pathology

Since the original 1995 report of a parkinsonian kindred, four individuals have been affected (mean age at onset, 65 years). All four had cardinal signs of Parkinson disease (PD) and good response to levodopa. Four autopsies showed neuronal loss and gliosis in the substantia nigra. Lewy bodies (LB) limited to brainstem nuclei were detected in one case, diffuse LB in the second, neurofibrillary tangles (NFT) without LB in the third, and neither NFT nor LB in the fourth. Genetic studies suggested linkage to the PARK8 locus on chromosome 12.

Neuropathology of two members of a German-American kindred (Family C) with late onset parkinsonism

We present genealogical and longitudinal clinical observations and autopsy findings of a previously reported kindred, Family C (German-American), with late-onset autosomal dominant parkinsonism with evidence for linkage on chromosome 2p13. The clinical phenotype includes the cardinal features of idiopathic Parkinson's disease. In addition, postural tremor and dementia are detected in some individuals. Two members of the kindred, one affected and one unaffected have recently come to autopsy. The unaffected family member was an 82-year-old woman whose brain showed only mild age-related pathology and no evidence of subclinical Lewy body disease. In contrast, the affected family member was an 83-year-old man whose brain had neuronal loss, gliosis and Lewy bodies in the substantia nigra and other monoaminergic brain stem nuclei, as well as the basal forebrain and amygdala. Lewy bodies and Lewy neurites had a distribution typical of cases of idiopathic Parkinson's disease. Thus, the clinical and pathological findings in this family with autosomal dominant parkinsonism are similar to those of sporadic Parkinson's disease.

Susceptibility to estrogen-induced mammary cancer segregates as an incompletely dominant phenotype in reciprocal crosses between the ACI and Copenhagen rat strains

Estrogens have been inextricably linked to the etiology of breast cancer. We have demonstrated that the female ACI rat exhibits a unique propensity to develop mammary cancers when treated continuously with physiological levels of 17 beta-estradiol (E2). The E2-induced mammary cancers are estrogen dependent and exhibit genomic instability. In contrast, the genetically related Copenhagen (COP) rat strain is relatively resistant to E2-induced mammary cancers. In this study we evaluated susceptibility to E2-induced mammary cancers in first filial (F(1)), second filial (F(2)), and backcross (BC) progeny generated from reciprocal intercrosses between the ACI and COP strains. F(1) progeny resembled the parental ACI strain with respect to incidence of E2-induced mammary cancers. However, latency was significantly prolonged in the F(1) populations. These data indicate that susceptibility behaves as an incompletely dominant phenotype in these crosses. Analysis of phenotypes exhibited by the F(1), F(2), and BC populations suggests that mammary cancer susceptibility is modified by one or two genetic loci in the reciprocal intercrosses between the ACI and COP strains. Susceptibility to E2-induced mammary cancers did not correlate with E2-induced pituitary growth in the genetically diverse F(2) and BC populations, suggesting that the genetic bases for susceptibility to E2-induced mammary cancers differ from those for E2-induced lactotroph hyperplasia.

Familial adenomatous polyposis and extracolonic cancer

Our purpose is to focus attention on the cancer family history, coupled with an understanding of the natural history and extracolonic tumor spectrum of familial adenomatous polyposis (FAP), through a family study. This family report provides an example of how colorectal cancer (CRC) can be prevented by knowledgeable gastroenterologists and colorectal surgeons who educate and compassionately counsel members of high-risk families so that their compliance with diagnostic screening and, ultimately, with protection through prophylactic colectomy, is achieved. A working pedigree of this extended family was constructed through interviews with the proband, followed by questionnaires sent to all primary and secondary relatives. Appropriately signed permission forms enabled us to secure pertinent medical and pathology records in order to ensure accuracy of historical information. Integral extracolonic tumors included medulloblastoma, papillary thyroid carcinoma, hepatoblastoma, and desmoid tumors. We conclude that, due in part to improved longevity as a result of being spared CRC, several family members have developed certain FAP integral extracolonic cancers.

Diet-gene interactions in estrogen-induced mammary carcinogenesis in the ACI rat

It is well accepted that hormonal, dietary and genetic factors each influence breast cancer risk. However, the underlying mechanisms and the extent to which these factors interact are largely unknown. We have demonstrated that the female ACI rat exhibits a unique genetically conferred propensity to develop mammary cancers when treated with physiological levels of 17beta-estradiol (E2). More recently, we have mapped to rat chromosome 5 a strong genetic modifier of susceptibility to E2-induced mammary cancers, termed estrogen-induced mammary cancer 1 (Emca1), and have identified potential Emca1 candidate genes. Because estrogens have been inextricably linked to the genesis of breast cancer in humans, the ACI rat model has the potential to reveal novel physiologically relevant insights into how the contributory actions of E2 are modified by specific dietary factors. In the present study, we have examined the ability of a 40% restriction of dietary energy consumption to inhibit E2-induced mammary carcinogenesis. The hypothesis tested was that energy restriction will inhibit mammary carcinogenesis even when circulating E2 remains elevated through administration of exogenous hormone. The data presented herein strongly suggest that energy restriction inhibits E2-induced mammary carcinogenesis in the ACI rat at least partly by retarding progression of atypical hyperplastic foci to carcinoma.

Postnatal developmental delay and supersensitivity to organophosphate in gene-targeted mice lacking acetylcholinesterase

Acetylcholinesterase (AChE; EC 3.1.1.7) is the primary terminator of nerve impulse transmission at cholinergic synapses and is believed to play an important role in neural development. Targeted deletion of four exons of the ACHE gene reduced AChE activity by half in heterozygous mutant mice and totally eliminated AChE activity in nullizygous animals. Butyrylcholinesterase (EC 3.1.1.8) activity was normal in AChE -/- mice. Although nullizygous mice were born alive and lived up to 21 days, physical development was delayed. The neuromuscular junction of 12-day-old nullizygous animals appeared normal in structure. Nullizygous mice were highly sensitive to the toxic effects of the organophosphate diisopropylfluorophosphate and to the butyrylcholinesterase-specific inhibitor bambuterol. These findings indicate that butyrylcholinesterase and possibly other enzymes are capable of compensating for some functions of AChE and that the inhibition of targets other than AChE by organophosphorus agents results in death.

Rat strain-specific actions of 17beta-estradiol in the mammary gland: correlation between estrogen-induced lobuloalveolar hyperplasia and susceptibility to estrogen-induced mammary cancers

The genetically related ACI and Copenhagen (COP) rat strains display diametrically opposed susceptibilities to mammary cancer development when treated chronically with 17beta-estradiol (E2). Here, we compare the actions of E2 on cell proliferation and lobuloalveolar development in the mammary glands of female ACI and COP rats. After 12 wk of E2 treatment, the mammary glands of ACI rats exhibited a significantly greater proliferative response to E2, compared with COP rats, as evidenced by quantification of S phase fraction and development of lobuloalveolar hyperplasia. Focal regions of atypical epithelial hyperplasia were observed in ACI, but not COP, rats. These strain differences were not because of differences in circulating E2, progesterone or, prolactin. Two-thirds of the induced mammary cancers in ACI rats exhibited aneuploidy. The E2-induced mammary cancers regressed when hormone treatment was discontinued, indicating that they were estrogen-dependent. Progesterone receptor was expressed by the great majority of epithelial cells within the E2-induced atypical hyperplastic foci and the mammary carcinomas, suggesting a link between these lesions. These data demonstrate a correlation between E2 action in the induction of mammary cell proliferation and atypical epithelial hyperplasia and genetically conferred susceptibility to E2-induced mammary cancers.

Predominance of brain tumors in an extended Li-Fraumeni (SBLA) kindred, including a case of Sturge-Weber syndrome

BACKGROUND

Li-Fraumeni syndrome (LFS) is characterized by a plethora of cancers, most prominent of which is carcinoma of the breast followed by sarcomas, brain tumors, leukemia, lymphoma, lung carcinoma, and adrenocortical carcinoma (therefore, also referred to by the acronym SBLA syndrome).

METHODS

The family reported herein was first described 2 decades ago. Now extensive follow-up has shown the predictable occurrence of these tumor types, in addition to an excess of brain tumors and the finding of Sturge-Weber syndrome (SWS) in an LFS-affected family member.

RESULTS

A possible new feature of the disorder, suggestive of SWS, was identified in a patient in the direct genetic lineage. This patient had a rhabdomyosarcoma of the eyelid at age 29 months and at age 14 years was diagnosed with lymphoblastic lymphoma/acute lymphoblastic leukemia. A remarkable excess of brain tumors was identified in this family through this current update. The p53 germ-line mutation was not identified in any affected member of this family.

CONCLUSIONS

To the authors' knowledge, this is the first example of SWS in the context of LFS. Brain tumors appear to be an important component of the tumor spectrum of LFS, as evidenced in this family.

Estrogen action in the regulation of cell proliferation, cell survival, and tumorigenesis in the rat anterior pituitary gland

Estrogens act as important regulators of cell proliferation, cell survival, and differentiation in a variety of organ systems and tissues and have been implicated in the etiology of a variety of malignant cancers and benign tumors. The anterior pituitary gland of the rat provides an excellent model for the study of estrogen action in the regulation of cell proliferation and survival. Estrogens stimulate proliferation of the prolactin (PRL)-producing lactotroph and enhance lactotroph survival. Through these actions on lactotroph proliferation and survival, estrogens induce or contribute to the development of PRL-producing pituitary tumors in several rat strains. Data from our laboratory and others indicate that estrogen-induced pituitary growth is rat strain specific and segregates as a quantitative genetic trait in crosses between different rat strains. The purpose of this review is to summarize current knowledge pertaining to estrogen action in the regulation of cell proliferation, cell survival, and tumorigenesis in the anterior pituitary gland of the rat species, Rattus norvegicus, and to illustrate the advantages of the rat pituitary gland as a model for elucidating the mechanisms through which estrogens regulate these processes.

Estrogen-induced pituitary tumor development in the ACI rat not inhibited by dietary energy restriction

We have demonstrated that a 40% restriction of dietary energy consumption virtually abolishes the development of prolactin (PRL)-producing pituitary tumors in Fischer 344 (F344) rats treated chronically with estrogen, apparently by inhibiting the ability of estrogen to enhance survival within a rapidly proliferating lactotroph population. The purpose of the study reported here was to determine whether energy restriction exerts a similar antitumorigenic action in another rat strain, August x Copenhagen-Irish (ACI), in which PRL-producing pituitary tumors develop in response to estrogen treatment. Ovariectomized female ACI rats were either allowed to consume a control diet ad libitum or were fed a modified diet that restricted energy consumption by 40% relative to the amount of energy consumed by animals fed the control diet. We also examined the ability of 17beta-estradiol (E2) administered for 20 wk via subcutaneous Silastic implants to induce development of PRL-producing pituitary tumors. Treatment with E2 increased pituitary weight as well as the pituitary weight-to-body weight ratio and induced gross hyperprolactinemia to the same extent in ACI rats fed either the control or the energy-restricted diet. Moreover, dietary energy restriction did not affect the ability of E2 to induce pituitary cell proliferation or inhibit apoptosis, as evidenced by quantification of two surrogate markers. These data provide compelling evidence that a 40% restriction of energy consumption does not inhibit the ability of E2 to induce pituitary tumor development in the ACI rat. In conjunction with our published studies of the F344 rat strain, the data presented herein indicate that the inhibitory effects of dietary energy restriction on estrogen-induced pituitary tumor development are rat-strain specific and suggest that sensitivity to specific antitumorigenic actions of energy restriction is strongly affected by genetic background.

Pediatric astrocytomas with monomorphous pilomyxoid features and a less favorable outcome

Among tumors classified as pilocytic astrocytoma (PA) in the Johns Hopkins Hospital Department of Pathology files, we identified 18 cases with a distinctive monomorphous pilomyxoid histological pattern and a higher recurrence rate than that of PA with classical histological features (classical PA). The majority of the tumors occurred in infants and young children and involved the hypothalamic/chiasmatic region. The tumors were histologically similar to PA, but they were more monomorphous and more myxoid. Rosenthal fibers were not seen and only 1 of 18 tumors had eosinophilic granular bodies. At the end of the follow-up period, 6 patients were dead and 12 were alive with evidence of disease. Progression free survival (PFS) at 1 year was 38.7%. In comparison, we identified a control group of 13 classical PAs in the same age range and location as the study group. In this group, PFS at 1 year was 69.2%, which was significantly better than that for pilomyxoid tumors (p = 0.04). There was no CSF dissemination or death due to tumor progression among patients with classical PA. Eight of these patients are alive with recurrent disease, and 4 have no evidence of disease. While the monomorphous pilomyxoid tumors have some resemblance to classical PA, our results suggest that the former is a more aggressive variant or a separate entity that needs to be recognized for prognostic purposes.

Genetic bases of estrogen-induced pituitary growth in an intercross between the ACI and Copenhagen rat strains: dominant mendelian inheritance of the ACI phenotype

Estrogens stimulate cell proliferation in a variety of tissues and are widely believed to be contributing factors in the etiology of certain cancer types in humans. The molecular mechanisms through which estrogens regulate cell proliferation are currently unknown. Estrogens stimulate proliferation of the PRL-producing lactotroph of the rat anterior pituitary gland and induce development of PRL-producing pituitary tumors in several inbred rat strains. Therefore, the lactotroph provides a well defined model for identifying the mechanisms through which estrogens regulate cell proliferation and/or survival. Data from our laboratory and others indicate that the relative sensitivity to the pituitary growth-promoting actions of estrogens is highly strain specific. This allows genetics-based approaches to be used to address the molecular mechanisms through which estrogens stimulate lactotroph proliferation and induce pituitary tumor development. In the present study we have examined the ability of diethylstilbestrol (DES) to induce pituitary growth in the genetically related AxC-Irish (ACI) and Copenhagen (COP) strains and their derived F1, F2, and backcross progeny. The data presented herein indicate that the anterior pituitary gland of the ACI strain displays approximately a 2-fold greater growth response to administered DES than does the pituitary gland of the COP strain. The average pituitary weight in male ACI rats was increased from 9.2 +/- 0.2 mg (mean +/- SD in untreated rats to 63.7 +/- 12.6 mg in rats treated with DES for 12 weeks, whereas in male COP rats, DES increased pituitary weight from 12.7 +/- 0.9 to 38.1 +/- 8.2 mg. The ACI phenotype was inherited in the F1, F2, and backcross progeny of an ACI x COP intercross as a dominant genetic trait, and the approximately 30 mg of additional pituitary growth displayed by the DES-treated ACI rat, relative to that of the treated COP rat, appeared to result from the actions of a single locus. Moreover, in F1 progeny from an ACI x Brown Norway intercross, the ACI phenotype was inherited as a dominant or incompletely dominant genetic trait. These data, when compared with findings of previous studies using the Fischer 344 rat strain, provide the first indication that distinct genetic pathways contribute to regulation of estrogen-induced pituitary growth and induction of PRL-producing pituitary tumors in the ACI and F344 rat strains.

Malignant supratentorial ganglioglioma (ganglion cell-giant cell glioblastoma): a case report and review of the literature

BACKGROUND

From both epidemiologic and pathologic viewpoints, gangliogliomas exhibiting components of giant cell glioblastomas are extraordinary neoplasms. We report herein the case of a 6-year-old girl who presented initially with a World Health Organization grade IV anaplastic ganglioglioma (a mixed ganglion cell tumor-giant cell glioblastoma). Despite aggressive management, the patient died of disease in a relatively short period.

METHODS

Formalin-fixed, paraffin-embedded tissue blocks were sectioned at 5 microm for histochemical and immunohistochemical analyses. Hematoxylin-eosin-stained sections and immunohistochemically stained sections from the primary and secondary resections were reviewed. Reactivity for glial fibrillary acidic protein, neurofilament protein, synaptophysin, and Ki67 nuclear antigen was evaluated.

RESULTS

Histologically, 2 distinct cell populations were noted on both the primary and secondary resections. The primary resection revealed a neoplasm having a predominant glial component consistent with a glioblastoma. Interspersed were dysmorphic ganglion cells supporting a diagnosis of ganglioglioma. The second resection (following therapy) demonstrated a much more prominent dysmorphic ganglion cell component and a subdued glial component.

CONCLUSION

Although immunohistochemical analysis clearly distinguished the 2 tumor cell populations, the identification of Nissl substance in neurons proved to be equally helpful. Although other cases of grade III gangliogliomas and rare cases of grade IV gangliogliomas have been reported, the present case is exceptional in that, to our knowledge, it is the only report of a patient who presented initially with a composite grade IV ganglioglioma and who was clinically followed up to the time of death. This case allows direct comparison between the histologic findings in a giant cell glioblastoma and a ganglioglioma and documents the aggressive biologic behavior of this complex neoplasm.

Modulation of estrogen action in the rat pituitary and mammary glands by dietary energy consumption

We are investigating the mechanisms through which estrogens induce development of prolactin (PRL)-producing pituitary tumors and mammary carcinomas in rats and how these mechanisms are affected by dietary energy consumption. The hypothesis under examination is that dietary energy restriction inhibits tumorigenesis in estrogen-responsive tissues by altering cellular responsiveness to estrogenic hormones. In the Fischer 344 (F344) rat strain, a 40% restriction of energy consumption virtually abolishes development of estrogen-induced pituitary tumors. Inhibition of pituitary tumorigenesis in the F344 strain by energy restriction results from modulation of estrogen regulation of cell survival, not cell proliferation. In contrast, energy restriction has no inhibitory effect on estrogen-induced pituitary tumor development in the ACI rat strain. However, energy restriction markedly inhibits induction of mammary carcinomas in female ACI rats treated with 17beta-estradiol. Data presented herein indicate that dietary energy restriction modulates the responsiveness of specific cell populations to estrogenic hormones and thereby inhibits estrogen-induced tumorigenesis in a manner specific to both rat strain and tissue.

Dietary energy restriction abolishes development of prolactin-producing pituitary tumors in Fischer 344 rats treated with 17beta-estradiol

Reduction in energy consumption is known to inhibit development of a variety of spontaneous, carcinogen-induced, and hormone-dependent cancers, but the mechanism or mechanisms by which this occurs remain unknown. We hypothesize that energy consumption may modulate development of estrogen-dependent neoplasms by altering the manner in which target cells respond to estrogens. To test this hypothesis, ovariectomized female Fischer 344 rats were fed diets that allowed consumption of different amounts of energy, and the ability of 17beta-estradiol (E2), administered for 10 wk from subcutaneous Silastic implants, to promote development of prolactin-producing pituitary tumors was examined. A 40% restriction of energy consumption virtually abolished the ability of E2 to promote development of pituitary tumors and associated hyperprolactinemia. A 25% restriction of energy consumption appeared to slightly inhibit E2-induced pituitary growth and hyperprolactinemia, but the observed degree of inhibition was not statistically significant. Interestingly, dietary energy restriction did not inhibit induction by E2 of pituitary cell proliferation and lactotroph hyperplasia. Furthermore, E2 treatment inhibited expression of testosterone-repressed prostate message-2 mRNA, a cellular marker of apoptosis, and this inhibitory effect of E2 was blocked by 40% energy restriction. These data suggest that dietary energy restriction virtually abolished E2-induced development of prolactin-producing pituitary tumors, not by blocking the ability of E2 to induce cell proliferation but rather by blocking the ability of E2 to enhance cell survival. This study and the accompanying paper provide the first indication that dietary energy consumption may modulate estrogen action at the level of the target cell.

Estrogen induction of prolactin-producing pituitary tumors in the Fischer 344 rat: modulation by dietary-energy but not protein consumption

Our laboratory is examining the hypothesis that diet may modulate the ability of estrogens to regulate cell proliferation and survival, either of which could affect development of neoplasms in estrogen-responsive tissues. In this study, we examined whether the amount of energy and protein consumed in the diet modulates the ability of the synthetic estrogen diethylstilbestrol (DES) to induce development of prolactin-producing pituitary tumors in two strains of rat, Fischer 344 (F344) and Holtzman, that differ in their propensity to develop pituitary tumors when treated with estrogens. Male F344 rats treated with DES for 8 wk developed pituitary tumors (defined as grossly enlarged pituitary masses that displayed diffuse lactotroph hyperplasia but lacked adenomatous foci). In contrast, male Holtzman rats displayed only a modest increase in pituitary weight in response to DES. Energy consumption but not protein consumption modulated DES-induced pituitary tumorigenesis in the male F344 rat. Relative to that observed in untreated animals, pituitary weights in F344 rats treated with DES increased 11.2- and 9.2-fold in animals fed either the control diet or an equicaloric high-protein diet, respectively, but only 3.5-fold in animals fed an energy-restricted diet. In contrast, neither the amount of energy nor protein consumed in the diet affected the modest pituitary growth response of male Holtzman rats to administered DES. Energy restriction had no apparent effect on pituitary cell proliferation, either basal or DES stimulated, in these rat strains. We concluded that dietary energy restriction inhibits the ability of administered DES to induce pituitary tumor development in the F344 rat by acting at a step after induction of pituitary cell proliferation.

Neuroleptic sensitivity to clozapine in dementia with Lewy bodies

Dementia with Lewy bodies (DLB) may be one of the most common causes of dementia. It should be of particular interest to psychiatrists because hallucinations are common presenting symptoms and because patients with DLB may be particularly sensitive to neuroleptics with respect to developing extrapyramidal symptoms. The authors describe 2 patients with DLB who were intolerant of clozapine, showing not extrapyramidal side effects, but an increase in confusion and behavioral symptoms.

Estrogen-induced tumorigenesis in the Copenhagen rat: disparate susceptibilities to development of prolactin-producing pituitary tumors and mammary carcinomas

The Copenhagen (COP) rat is unique among inbred rat strains in its high degree of resistance to spontaneously arising and induced mammary cancers. Hyperprolactinemia resulting from tumors of the anterior pituitary gland has been suggested to be the causative factor in the etiology of estrogen-induced mammary cancer in rats. Therefore, we have examined the ability of administered estrogens to induce development of PRL-producing pituitary tumors and mammary carcinomas in COP rats. Diethylstilbestrol (DES), administered to male COP rats for 12 weeks, beginning when the animals were 9 weeks of age, induced development of PRL-producing pituitary tumors, defined as grossly enlarged pituitary masses displaying lactotroph hyperplasia and associated hyperprolactinemia. When treated with 17beta-estradiol (E2), female COP rats developed pituitary tumors and hyperprolactinemia, but displayed a high degree of resistance to development of mammary carcinomas. These data indicate that E2-induced hyperprolactinemia is insufficient to induce development of mammary carcinomas in the female COP rat.

Inactivation of the FGF-4 gene in embryonic stem cells alters the growth and/or the survival of their early differentiated progeny

Previous studies have shown that early mouse embryos with both FGF-4 alleles inactivated are developmentally arrested shortly after implantation. To understand the roles of FGF-4 during early development, we prepared genetically engineered embryonic stem (ES) cells, which are unable to produce FGF-4. Specifically, we describe the isolation and characterization of ES cells with both FGF-4 alleles inactivated. The FGF-4-/- ES cells do not require FGF-4 to proliferate in vitro, and addition of FGF-4 to the medium has little or no effect on their growth. Thus, FGF-4 does not appear to act as an autocrine growth factor for cultured ES cells. We also demonstrate that FGF-4-/- ES cells, like their unmodified counterparts, are capable of forming highly complex tumors in syngeneic mice composed of a wide range of differentiated cells types, including neural tissue, glandular epithelium, and muscle. In addition, we demonstrate that the FGF-4-/- ES cells can differentiate in vitro after exposure to retinoic acid; however, the growth and/or survival of the differentiated cells is severely compromised. Importantly, addition of FGF-4 to the culture medium dramatically increases the number of differentiated cells derived from the FGF-4-/- ES cells, in particular cells with many of the properties of parietal extraembryonic endoderm. Finally, we demonstrate that there are differences in the RNA profiles expressed by the differentiated progeny formed in vitro from FGF-4-/- ES cells and FGF-4+/+ ES cells when they are cultured with FGF-4. Taken together, the studies described in this report indicate that certain lineages formed in vitro are affected by the inactivation of the FGF-4 gene, in particular specific cells that form during the initial stage of ES cell differentiation. Thus, ES cells with both FGF-4 alleles inactivated should shed light on the important roles of FGF-4 during the early stages of mammalian development and help determine why FGF-4-/- embryos die shortly after implantation.

Familial parkinsonism, dementia, and Lewy body disease: study of family G

Genetic influences are thought by many to play an important role in the cause of Parkinson's disease. We studied two closely intermarried families (Family G) whose ancestors immigrated to the United States from Russia. We investigated this family clinically, genealogically, and pathologically. Our pedigree contained 102 members spanning six generations, with 10 affected individuals and 1 affected spouse. Detailed telephone interviews were conducted with affected individuals, with their spouses, and with their at-risk siblings. Medical records of deceased and living affected patients were collected. Physical examinations were performed on 7 at-risk and 5 affected persons. Typical levodopa-responsive parkinsonism with bradykinesia, rigidity, resting tremor, and impaired postural reflexes was seen in 4 members, dementia was present in 3, and 3 had both dementia and parkinsonism. An autopsy completed on 1 individual, our index case, demonstrated Lewy bodies in the brainstem and neocortex and ubiquitin-positive neuritic degeneration in the CA2-3 region of the hippocampus, consistent with the limbic (transitional) form of Lewy body disease. This family is distinct both clinically and pathologically from several previously reported parkinsonian kindreds.

Cytogenetic analysis of a malignant triton tumor and a malignant peripheral nerve sheath tumor and a review of the literature

Cytogenetic analyses of malignant peripheral nerve sheath tumors (MPNST) and malignant triton tumors (MTT) are few to date. Two separate triton tumor specimens from one patient and a MPNST specimen from another patient, both with peripheral neurofibromatosis (NF-1, von Recklinghausen disease), showed complex near-triploid complements and partial deletion of the short arm of chromosome 1. Notably, a structural abnormality of chromosome 17 was detected in the MPNST, and loss of chromosome 22 was detected in the MTT. The genes for peripheral neurofibromatosis (NF-1) and central neurofibromatosis (NF-2) have been mapped to these two chromosomes respectively.

Mechanisms for the transendothelial migration of HIV-1-infected monocytes into brain

HIV-1 penetration of the brain is a pivotal event in the neuropathogenesis of AIDS-associated dementia. The establishment of productive viral replication or up-regulation of adhesion molecule expression on brain microvascular endothelial cells (BMVEC) could permit entry of HIV into the central nervous system. To investigate the contribution of both, we inoculated primary human BMVEC with high titer macrophage-tropic HIV-1 or cocultured them with virus-infected monocytes. In both instances, BMVEC failed to demonstrate productive viral replication. Cell to cell contact between monocytes and microvascular endothelium resulted in E-selectin expression on BMVEC. BMVEC. cocultured with LPS-activated HIV-infected monocytes expressed even higher levels of E-selectin and vascular cell adhesion molecule-1 (VCAM-1). Transwell assays supported a role of soluble factors, from virus-infected monocytes, for the induction of adhesion molecules on BMVEC. To verify the in vivo relevance of these findings, levels of adhesion molecules were compared with those of proinflammatory cytokines and HIV-1 gene products in brain tissue of AIDS patients with or without encephalitis and HIV-seronegative controls. E-Selectin, and to a lesser degree VCAM-1, paralleled the levels of HIV-1 gene products and proinflammatory cytokines in brain tissue of subjects with encephalitis. Most importantly, an association between macrophage infiltration and increased endothelial cell adhesion molecules was observed in encephalitic brains. Monocyte binding to encephalitic brain tissue was blocked with Abs to VCAM-1 and E-selectin. These data, taken together, suggest that HIV entry into brain is, in part, a consequence of the ability of virus-infected and immune-activated monocytes to induce adhesion molecules on brain endothelium.

Mechanisms for the transendothelial migration of HIV-1-infected monocytes into brain

HIV-1 penetration of the brain is a pivotal event in the neuropathogenesis of AIDS-associated dementia. The establishment of productive viral replication or up-regulation of adhesion molecule expression on brain microvascular endothelial cells (BMVEC) could permit entry of HIV into the central nervous system. To investigate the contribution of both, we inoculated primary human BMVEC with high titer macrophage-tropic HIV-1 or cocultured them with virus-infected monocytes. In both instances, BMVEC failed to demonstrate productive viral replication. Cell to cell contact between monocytes and microvascular endothelium resulted in E-selectin expression on BMVEC. BMVEC. cocultured with LPS-activated HIV-infected monocytes expressed even higher levels of E-selectin and vascular cell adhesion molecule-1 (VCAM-1). Transwell assays supported a role of soluble factors, from virus-infected monocytes, for the induction of adhesion molecules on BMVEC. To verify the in vivo relevance of these findings, levels of adhesion molecules were compared with those of proinflammatory cytokines and HIV-1 gene products in brain tissue of AIDS patients with or without encephalitis and HIV-seronegative controls. E-Selectin, and to a lesser degree VCAM-1, paralleled the levels of HIV-1 gene products and proinflammatory cytokines in brain tissue of subjects with encephalitis. Most importantly, an association between macrophage infiltration and increased endothelial cell adhesion molecules was observed in encephalitic brains. Monocyte binding to encephalitic brain tissue was blocked with Abs to VCAM-1 and E-selectin. These data, taken together, suggest that HIV entry into brain is, in part, a consequence of the ability of virus-infected and immune-activated monocytes to induce adhesion molecules on brain endothelium.

Utility of cerebral proton magnetic resonance spectroscopy in differential diagnosis of HIV-related dementia

Opportunistic infections often coexist with human immunodeficiency virus (HIV) infection in brain. Making the correct diagnosis is often difficult despite recent advances in neuroimaging techniques. 1H magnetic resonance spectroscopy (1H MRS) is an emerging non-invasive examination for diagnosis and monitoring of brain disorders. 1H MRS measures a variety of organic compounds using magnetism and radio waves. Biochemical aberrations in brain, not shown by conventional tests, may be demonstrated by 1H MRS testing. A patient coinfected with HIV and hepatitis B (HBV) presented with progressive dementia. Clinical, neuroradiological and cerebrospinal fluid (CSF) examinations failed to provide a diagnosis in support of either HIV-1-associated cognitive/motor complex or HBV-induced hepatic encephalopathy (HE), 1H MRS was used in an attempt to discriminate between these diagnoses. Spectroscopy demonstrated increased glutamine and normal N-acetyl aspartate (NAA) levels, metabolic changes consistent with HE. These findings were later confirmed pathologically. Proton magnetic resonance spectroscopy is a non-invasive test with utility for the differential diagnosis of HIV-associated dementia.

Antiserum against neuropeptide Y enhances the nicotine-mediated release of catecholamines from cultured rat adrenal chromaffin cells

A primary culture of chromaffin cells was prepared from adult rats and the stability of cell contents, NPY and catecholamines (CAs), during the culture was studied. The responsiveness of cultured chromaffin cells to NGF or secretagogues and the possible role of NPY on the CA secretion from cultured chromaffin cells were investigated. After plating of isolated cells, there was marked decrease in the cell content of CAs but a significant increase in the cell content of NPY. Though both NPY and CAs in the cultured cells were positively regulated by NGF, the results of this study seemed to suggest a differential regulation for NPY and CAs in the chromaffin cell. The cultured chromaffin cells secreted NPY and CAs in response to stimulation by nicotine. The nicotine stimulated secretion of CA was enhanced by the presence of IgG fraction, prepared from NPY antiserum, in the secretion medium. The results suggested that NPY was co-released with CAs from chromaffin cells and then acted as a modulator on CA secretion.

Tissue factor antigen in senile plaques of Alzheimer's disease

Tissue factor (tissue thromboplastin) is the primary initiator of the extrinsic coagulation pathway, triggering a proteolytic cascade when exposed to circulating coagulation factors. In this study, the distribution of tissue factor was examined immunohistochemically in Alzheimer's disease (AD) and control brains. Tissue factor was expressed diffusely in the neocortex, but in AD there was enhanced immunoreactivity in senile plaques. Although tissue factor might potentially contribute to the formation of senile plaques, it could also accumulate in the plaques as a secondary response to other biochemical perturbations.

Retreatment of advanced esthesioneuroblastoma with high-activity I-125 endocurietherapy: a case report

A 67-year-old woman presented with an advanced esthesioneuroblastoma that recurred 2 years following external irradiation. She was successfully retreated with continuous low-dose rate interstitial irradiation from high-activity I-125 seeds implanted permanently into the tumor.

Intraventricular neurocytoma: a report of two cases

Intraventricular neurocytoma is a rare clinicopathological entity that has been recently recognized. Previous reports have not described the magnetic resonance imaging findings of this tumor. This paper describes two patients with neurocytoma in which serpiginous flow voids and isointensity with cortex were distinctive features on the magnetic resonance imaging scan. Immunohistochemical studies showed reactivity for neuron-specific enolase, Leu-7, and S-100 protein.

Dentatorubro-pallidoluysian atrophy of the myoclonus epilepsy type with posterior column degeneration

Dentatorubro-pallidoluysian atrophy (DRPLA) has a variable clinical presentation but the pathology is routinely confined to cerebellifugal and pallidofugal systems. We present a case of DRPLA of the myoclonus epilepsy type in which prominent posterior column degeneration was added to the pathological picture. This case illustrates the concept that the neurodegenerative diseases can be a continuum of both clinical and pathological presentations.

Pontine and extrapontine myelinolysis following liver transplantation. Relationship to serum sodium

The relationship between central pontine myelinolysis (CPM) and extrapontine myelinolysis (EPM) and serum sodium changes in the setting of orthotopic liver transplantation (OLT) is examined. Postmortem examination of 14 patients with end-stage liver disease who underwent liver transplantation revealed CPM in four, of which three also had EPM. A retrospective review of clinical and laboratory data was performed on all patients. There were marked perioperative rises (21-32 mEq/L) in the serum sodium concentration in all four patients who developed myelinolysis. In contrast, the largest increase in sodium in patients without demyelination was 16 mEq/L. We conclude that perioperative rises in the serum sodium concentration increase the risk of myelinolysis. CPM and EPM should be considered if the patient develops mental status changes or focal neurological deficits several days after OLT.

Lateral pontine and extrapontine myelinolysis associated with hypernatremia and hyperglycemia

Efforts to understand and prevent pontine and extrapontine myelinolysis have focused on the correction of hyponatremia, but controversy persists. We report a woman who presented in hyperosmolar diabetic coma with hypernatremia (169 mEq/l) and hyperglycemia (954 mg/dl). Plasma sodium rapidly increased to 188 mEq/l before gradually returning to normal. She remained obtunded and died 21 days later. Autopsy showed widespread, symmetrical demyelination involving the subcortical white matter, corpus callosum, anterior commissure, extreme, external, and internal capsules, fornix, thalamus, cerebellum, and lateral pons. The central pons and lateral geniculate nuclei were uninvolved. This case illustrates that lateral pontine and extrapontine myelinolysis can be associated with hypernatremia and hyperosmolality. In both hypo- and hypernatremic states, the significant event may be an increase in serum sodium or serum osmolality of sufficient rapidity and magnitude.

Survival of patients with glioblastoma multiforme treated by intraoperative high-activity cobalt 60 endocurietherapy

The authors report their initial treatment results in 49 patients with glioblastoma multiforme (GM) who received intraoperative endocurietherapy (ECT) with high-activity cobalt 60 (60Co) probe. Thirty poor prognosis (unresectable tumor) patients (Group I) with newly diagnosed GM were treated by either biopsy or subtotal excision, followed by 20.00-Gy single-fraction 60Co probe ECT, and 60.00-Gy external-beam radiation therapy (EXRT) (80.00 Gy total tumor dose). Nineteen patients (Group II) with recurrent, previously resected and externally irradiated GM were retreated with 20.00-Gy single-fraction 60Co probe ECT alone. The authors' initial experience with intraoperative ECT of GM is discussed.

Castleman's disease of the leptomeninges. Report of three cases

Castleman's disease is a rare, benign lymphoproliferative disorder that usually arises in lymph nodes, most commonly in the mediastinum. The authors report the clinical and pathological features of three patients with localized Castleman's disease of the leptomeninges. There were two women, aged 63 and 82 years, and one 25-year-old man. Two patients had progressive focal motor seizures of 3 and 24 months' duration, and the third patient presented acutely with generalized seizures. The clinical diagnosis was meningioma in each case, based on computerized tomography scans, cerebral arteriography, and the operative findings. All three lesions arose in the leptomeninges, compressed the underlying cerebral cortex, and infiltrated the overlying dura to a variable extent. Surgical excision of the tumor resulted in marked clinical improvement in all three patients. Histologically, two cases were classified as the hyaline-vascular type and one as the plasma cell type. Immunohistochemical stains of the latter case revealed a monoclonal population of mature plasma cells. Only a few scattered polyclonal plasma cells were seen in the other two cases. The authors conclude that Castleman's disease involving the leptomeninges is a rare disorder that may mimic meningioma clinically and radiographically.

Contrast-enhancing computed tomography ring in glioblastoma multiforme after intraoperative endocurietherapy

The significance of the contrast-enhancing ring seen on serial follow-up postirradiation computed tomograms (CT) of the brain was evaluated in a group of 41 patients with glioblastoma multiforme (GM) who were treated in a phase I/II study by means of intraoperative remote afterloading endocurietherapy (ECT) with a high activity cobalt 60 probe (20.00 Gy) in one high-dose rate fraction), and conventional fractionated external-beam (EXRT) radiotherapy (60.00 Gy in 30 fractions in 7.5 weeks). All received minimum total tumor doses of 80.00 Gy. After completion of treatment, all patients were followed with serial CT scans of the brain. Two to 6 months after treatment, 27 of 41 patients developed the similar thin-walled, regular, contrast-enhancing CT rings with low-density attenuation inside and outside the ring. Postmortem study in two of these patients revealed that the thin-walled, regular, contrast-enhancing ring represented a continuous capsule of dilated cerebral vessels with inner low-density attenuation corresponding to necrosis, and outer low-density attenuation corresponding to edema. The CT appearance of the thin-walled, regular, contrast-enhancing ring produced after high-dose rate intraoperative ECT and EXRT is distinctly different from the CT ring characteristic of untreated or recurrent GM. After high-dose rate intracranial ECT and EXRT, the appearance of a post-ECT contrast-enhancing CT ring should not be automatically interpreted as recurrent disease as previously reported after conventional fractionated EXRT.

Alpha-glucosidase deficiency and basilar artery aneurysm: report of a sibship

Glycogen deposition in vascular smooth muscle has been demonstrated previously in alpha-glucosidase deficiency but has not been clinically significant. Three sons of healthy, nonconsanguineous parents developed progressive proximal muscular weakness secondary to alpha-glucosidase deficiency. Each patient developed a fusiform basilar artery aneurysm, which was complicated by fatal rupture in two patients and a cerebellar infarction in the third. Postmortem examination demonstrated severe vacuolation of skeletal muscle, liver, and vascular smooth muscle with accumulation of periodic acid-Schiff-positive, diastase-sensitive material. In the surviving brother, similar glycogen deposition was demonstrated in the smooth muscle of the superficial temporal artery. Basilar artery aneurysm formation in this sibship may be a consequence of alpha-glucosidase deficiency.

Distribution of type VI collagen in human gliomas: comparison with fibronectin and glioma-mesenchymal matrix glycoprotein

The distribution of type VI collagen was examined immunohistochemically in normal tissues and in 24 human gliomas and six medulloblastomas. Its localization in the neoplasms was compared with that of fibronectin and glioma-mesenchymal extracellular matrix (GMEM) glycoprotein. In normal non-neural tissues type VI collagen was demonstrated in the interstitial connective tissue and in some basement membranes. In normal brain it was localized to the vasculature, leptomeninges, and pial-glial membrane. In neoplasms type VI collagen and fibronectin codistributed in the vasculature and stromal connective tissue. The GMEM glycoprotein, as identified by monoclonal antibody (MAb) 81C6, and a related glioma-mesenchymal matrix antigen identified by MAb 2A6, were expressed not only in the tumor vasculature and connective tissue, but also within the tumor parenchyma in association with glioma cells. The staining intensity was variable in 20 malignant gliomas and weak to absent in two pilocytic astrocytomas and six medulloblastomas. An oligodendroglioma and ependymoma both expressed the 2A6 epitope, but staining with MAb 81C6 was weak to absent. The antigens identified by MAb 81C6 and MAb 2A6 represent the only recognized extracellular matrix components, other than proteoglycans, that are associated with glioma cells in vivo. As prominent constituents of the pericellular matrix, they may be involved in recognized matrix functions such as the modulation of cell adhesion and migration.

Juvenile polysaccharidosis with cardioskeletal myopathy

Polysaccharidoses with ultrastructural features reminiscent of glycogenosis type IV, but without enzymatic correlation, have been observed in several adolescent and adult patients. Little is known of the clinical, pathologic, or biochemical nature of these disorders. We describe a patient with ultrastructural characteristics consistent with glycogenosis type IV, but with normal brancher enzyme activity in dermal fibroblasts and cardiac muscle. During life and at autopsy, electron microscopy revealed amylopectin-like polysaccharide deposits present in a wide variety of tissues. The polysaccharidosis of our patient and similar patients may be a variant of glycogenosis type IV with a yet to be defined enzymatic defect.

Spinal metastases from pituitary hemangiopericytic meningioma

A rare, previously irradiated, recurrent malignant angioblastic meningioma of the pituitary, hemangiopericytic type, was locally controlled by a new endocurietherapy technique that allows delivery of very high (10,000 cGy), sharply localized irradiation. Rather than succumbing to the local tumor recurrence, as would otherwise be expected, the patient developed distant spinal metastases several years later.

Metameric capillary hemangioma producing complete myelographic block in an infant. Case report

A variety of lesions of ectodermal, mesodermal, (rarely) endodermal, or mixed-cell layer origin involve the region of the conus medullaris. Some of these abnormalities produce cord tethering and others, such as lipoma, frequently present as masses. In the present case, an infant was discovered to have a lesion most closely resembling a capillary hemangioma involving the skin of the midline and right buttock, the deep soft tissues of the right buttock, the dura, and the conus medullaris. The origin of this congenital spinal tumor from primitive mesoderm is proposed in light of its metameric pattern of distribution.

Cerebellar hemangioblastoma with prominent stromal astrocytosis: diagnostic and histogenetic considerations

A cerebellar hemangioblastoma with atypical radiologic and morphologic features is reported. On computed tomography this tumor presented as a single ring-enhancing mass in the right cerebellar hemisphere without adjacent cyst formation. It was radiologically indistinguishable from an abscess or malignant neoplasm. Postmortem examination demonstrated a circumscribed, cystic neoplasm arising in the pia at the base of a sulcus. Microscopically, the tumor contained a prominent astrocytic component that mimicked the appearance of a highly vascular astrocytoma. Hemangioblastomas with this degree of astrocytosis are unusual. They must be distinguished pathologically from both cystic astrocytoma and mixed hemangioblastoma-glioma (angioglioma).

Hypothalamic hamartoma: a report of 2 cases

Two patients with hypothalamic hamartoma presented with isosexual precocious puberty. LHRH challenge showed a pubertal LH response in both cases. Serum FSH responses to LHRH were pubertal in case 1, but prepubertal for case 2. Computed tomography revealed isodense noncontrast-enhancing retrosellar mass lesions in both cases. The tumors were composed of mature neurons and neuroglial tissue. Electron microscopy of the lesions failed to demonstrate dense core (neurosecretory) granules in either case. Subtotal removal of the harmartomas resulted in decreased LH responsiveness to LHRH in both cases. Serum FSH responsiveness to LHRH was not significantly suppressed postoperatively in case 1, and FSH responsiveness to LHRH in case 2 showed exaggerated levels, more typical of very young prepubertal girls. Postoperative magnetic resonance imaging (MRI) scans of both patients are also presented.

Expression of glial fibrillary acidic protein in human glioma cell lines as detected by molecular hybridization

The expression of glial fibrillary acidic protein (GFAP) in continuous glioma and non-glioma cell lines was evaluated by molecular hybridization and immunocytochemistry. RNA transcripts from the GFAP gene were detected in two of six cell lines by Northern blot analysis of cellular RNAs using a cloned mouse GFAP cDNA probe. The probe recognized a single GFAP RNA species of 2.7 kilobases under high-stringency washing conditions. The presence of GFAP transcripts as determined by molecular hybridization corresponded to the immunocytochemical detection of GFAP using two different monoclonal antibodies to this protein. These data indicate that GFAP expression in human cells can be detected by molecular hybridization using a murine GFAP cDNA probe, illustrating the high degree of inter-species conservation of GFAP. Molecular hybridization represents a reliable and sensitive method for the detection of GFAP expression in vitro, which can be used in conjunction with or as an alternative to immunocytochemistry.

Pathologic analysis of primary brain tumors

Diffuse astrocytomas of the cerebrum, cerebellum, brain stem, and spinal cord are classified into three groups according to the degree of tumor anaplasia. These groups are the astrocytoma, anaplastic astrocytoma, and glioblastoma multiforme. Juvenile pilocytic astrocytomas have a better prognosis and are clinically and biologically distinct from the diffuse, fibrillary astrocytomas. The prognosis of astrocytomas depends not only on histologic characteristics, but also age of the patient, location of the tumor, and extent of surgical resection. The pattern of invasion into surrounding brain distinguishes gliomas from metastatic carcinomas and sarcomas. Topographic correlations have shown that malignant gliomas may invade the brain for distances of up to several centimeters from the enhancing rim seen on CT scan. However, the junction between glioblastoma and adjacent brain may also be fairly abrupt, with a peripheral margin of less than 1 mm. Recurrent glioblastomas are more widely invasive and often extend into areas that appear normal on CT scan. The optimal site for tumor biopsy corresponds to areas of contrast enhancement. Primitive neuroepithelial tumors are malignant neoplasms with a poor prognosis. They tend to recur locally and metastasize throughout the neuraxis via the CSF. It remains controversial whether these tumors should be classified as a single entity with the potential for differentiation along different cell lines, or whether the categories of neuroblastoma, spongioblastoma, ependymoblastoma, pineoblastoma, and medulloblastoma should be retained as specific entities. The medulloblastoma is the most common of these neoplasms, its clinicopathologic features are well characterized, and the current 5-year survivals of 50 to 60 per cent are better than for other "primitive" neoplasms. Glial fibrillary acidic protein is a specific marker for immature, reactive, and neoplastic astrocytes and ependymal cells. Although the absence of GFAP in a neoplasm does not exclude an astrocytic origin, the presence of GFAP indicates astrocytic or ependymal differentiation. This has important diagnostic applications. The expression of GFAP is used to distinguish astrocytic neoplasms from epithelial or mesenchymal tumors that may on occasion mimic a glioma. The detection of GFAP is also useful in the investigation of tumor histogenesis and differentiation both in vivo and in vitro. Although meningiomas exhibit a wide variety of histologic patterns, most tumors exhibit similar biologic and clinical behavior regardless of the histologic subtype.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunolocalization of monoclonal antibody-defined extracellular matrix antigens in human brain tumors

The extracellular matrix is involved in many aspects of tumor cell biology, including tumor invasion and metastasis. 2A6 and 81C6 are murine monoclonal antibodies that identify glioma-mesenchymal extracellular matrix antigens. The 81C6 antigen is a high molecular weight glycoprotein composed of Mr 230,000 subunits. The expression of 2A6 antigen, 81C6 glycoprotein, fibronectin (FN), and laminin (LN) was examined immunohistochemically in ten malignant gliomas (MG) and four medulloblastomas (MBT). 2A6 and 81C6 were expressed in similar patterns by the neoplastic neuroepithelial cells in 9/10 MG and 1/4 MBT. The staining was typically diffuse and amorphous, without visualization of distinct cell bodies or processes. Less frequently, antigen was detected within tumor cell cytoplasm. In most tumors the staining was greatest in the perivascular regions. In two MG, 2A6 and 81C6 were expressed only by a subpopulation of neoplastic cells. Although intense staining was also associated with hyperplastic vascular and mesenchymal cells, many small and medium size blood vessels stained weakly or not at all. In contrast, FN and LN were expressed uniformly and intensely in the tumor vasculature, but were not expressed by neoplastic neuroepithelial cells. The 2A6 antigen and 81C6 glycoprotein are immunohistochemically distinct from FN and LN. These monoclonal antibody-defined antigens are heterogeneously expressed by neoplastic neuroepithelial cells and hyperplastic vascular-mesenchymal elements in MG and MBT. The 2A6 and 81C6 monoclonal antibodies will be useful reagents in the investigation of the extracellular matrix of malignant neuroepithelial neoplasms.

Antigenic heterogeneity of human anaplastic gliomas and glioma-derived cell lines defined by monoclonal antibodies

The antigenic heterogeneity of human neuroectodermal tumors defined by both murine and human monoclonal antibodies (MAs) is reported; no patterns of reactivity defining degree of anaplasia, in vitro morphology, or immunogen used were apparent. We investigated the reactivity of 20 distinct murine MAs defining markers of glioma-associated or predominantly lymphoid distribution for 13 human glioma-derived (HGL) cell lines and frozen sections of 19 human glioblastoma multiforme (GBM) and six astrocytomas (AST). Methods included radioimmunoassay, immunofluorescence, immunohistochemistry, and absorption analysis. Two markers, HLA-A,B and human Thy-1, exhibited no deviation; all HGL cell lines tested bound high levels of specific MA. Individual HGL cell line reactivity with the MA panel ranged from 30 to 70%. HGL cell lines (7/13) which reacted with greater than or equal to 50% of the antiglioma MAs had the highest (30-70%) positive reactivity rates with the anti-lymphoid marker MA panel; complex antigenicity in one system correlated with multiple antigens in the other. Within the anti-lymphoid marker MA panel, subpopulations of 4/13 HGL cell lines were clearly positive for the HLA-DR (Ia) antigens; another 3/13 HGL cell lines were strongly positive for common acute lymphocytic leukemia antigen (CALLA). With the exception of Thymocyte 1 antigen (Thy-1), reactivity for early and mature T-cell markers was infrequent and sporadic. Lymphoid marker expression by HGL cell lines is highly heterogeneous, ranging from few (Thy-1 and HLA-A,B) to complex expression of Ia, T-cell, and lymphoid tumor markers. GBM and AST tissues were antigenically less complex; for each of 6/8 anti-glioma MA, 70-100% of GBM and 66-100% of AST were positive. Two MAs were highly reactive (7/10, 8/9) with GBM sections and minimally so (1/6) with AST. Antigenic expression in gliomas is complex and heterogeneous; however, clear differences in lymphoid marker expression, the identification of widely and rarely expressed glioma-associated antigens, and the potential of immunologic differentiation between GBM and AST by large panels of MAs will serve to reduce the complexity and may be of potential diagnostic or prognostic significance.