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Biomedical subjects

J F Llena

Publications and source records attributed to J F Llena.

At least 19 recordsLinked to original sources
PubMed1998

Solitary primary CNS lymphoma: long term survival following total resection.

Primary non-Hodgkin's CNS lymphoma is rare, constituting 0.3-1.5% of all intracranial neoplasms in patients without AIDS. In the past 10 years the incidence has tripled in this population. The role of surgery is commonly limited to obtaining adequate tissue for diagnosis. This has precluded the evaluation of total surgical resection for a surgically accessible solitary lesion. We have encountered a 36-year-old healthy white male with primary CNS lymphoma who is HIV-negative and who has survived over five years disease free after total surgical resection of his lymphoma.

Adult↗
PubMed1998

Rhabdoid transformation of tumor cells in meningiomas: a histologic indication of increased proliferative activity: report of four cases.

Four cases of meningeal tumors in adults (ages ranging from 28 to 84 years) are presented. All had the typical gross appearance of meningiomas at operation. In three tumors, areas of meningothelial or fibroblastic meningiomas showed transition to cell groups of the rhabdoid type. In the fourth case only rhabdoid cells were encountered, possibly representing a total "take-over" of a meningioma by rhabdoid elements. In the three cases with mixed pattern, the rhabdoid cells showed more anaplasia and atypism than the conventional meningiomatous elements. In case 3 this was expressed by very high MIB-1 positivity in the rhabdoid cells and absence of same in the fibroblastic meningiomatous elements. These cases (the first three with certainty, the fourth with a strong likelihood) indicate that the phenotypic changes to cells with "rhabdoid" morphology may involve meningiomas and that such change is associated with aggressive biologic and clinical behavior of the tumors showing this type of alteration.

Adult↗
PubMed1998

Paraganglioma of the filum terminale: case report and literature review.

A rare case of a paraganglioma of the filum terminale is reported. The patient presented with headache and papilledema. Magnetic resonance imaging demonstrated enlarged ventricles of the brain and a well-demarcated intradural spine tumor. After resection of the tumor, the papilledema and headaches resolved, and the ventricles returned to normal size. Pathologic examination revealed a paraganglioma of the filum terminale. We present this rare case and review the literature of spinal paragangliomas as well as the association of spinal tumors with hydrocephalus.

Adult↗
PubMed1997

A histopathological study of craniopharyngioma with special reference to its stroma and surrounding tissue.

The numerous pathology reports on craniopharyngioma describe the classical features of squamous epithelium and keratin. Relatively little attention has been paid to its stroma and the surrounding tissue. We focused our observation on these two areas in a retrospective study of craniopharyngiomas in 36 operative cases and 5 autopsy cases. The tumor interdigitated with the brain and pituitary gland. At the interface, the brain was markedly gliotic with Rosenthal fibers simulating pilocytic astrocytoma. The tumor stroma had reactive changes and commonly showed cyst formation and calcification.

Adolescent↗
PubMed1997

Epithelial differentiation in intraspinal meningiomas.

To investigate the epithelial features of intraspinal meningiomas, 25 intraspinal meningiomas and 25 intracranial meningiomas were examined for the presence of pseudopsammoma bodies with hematoxylin-eosin and periodic acid-Schiff staining. In addition, we investigated the expression of keratin and epithelial membrane antigen (EMA) by immunohistochemical methods. Pseudopsammoma bodies were found in 3 of 25 cases of intracranial meningiomas (12%), but no definitive pseudopsammoma bodies were observed the intraspinal meningiomas. Three cases (12%) of intraspinal meningiomas and 9 cases (36%) of intracranial meningiomas, including 3 cases with pseudopsammoma bodies, were immunoreactive for keratin. All 25 (100%) intracranial meningiomas and 20 of 25 (84%) intraspinal meningiomas were reactive for EMA. In the intraspinal meningiomas, 4 of 25 cases (16%) showed no reactivity for EMA. These findings suggest that the origin of certain cell components of meningiomas may be different according to the site of the tumor or that the nature of meningioma may be modified by the local environment.

Aged↗
PubMed1997

Glioma of the tongue.

A case of glioma of the tongue that was treated successfully by simple excision and repair is presented. It may represent neural tissue that remains in the occipital somites that differentiate into the tongue muscles. Histologically, it consists of sheets of glial tissue. The literature is reviewed, and the case is discussed.

Child, Preschool↗
PubMed1996

Ganglion cyst of the odontoid process. Case report and review of the literature.

STUDY DESIGN: This case report illustrates that although it is rare, a ganglion cyst can occur intraosseously in the odontoid process. OBJECTIVES: The tissue diagnosis was established by surgical resection of the cyst membrane and evacuation of the cyst content. The patient tolerated the procedure well, and the hospital course was uneventful. SUMMARY OF BACKGROUND DATA: Synovial cyst of the spine is uncommon and is usually found in the lumbar region. Its occurrence in the cervical spine is rare, and no cases in the odontoid process, to the authors' knowledge, have been reported. METHODS: This patient was evaluated initially for neck pain, which led to radiographic studies depicting the lesion. It raised the suspicion of metastatic neoplastic process, although the search for primary source proved to be negative. A biopsy was indicated. RESULTS: Surgical findings consisted of mucoid material field cavity lined by a thin membrane. The cyst was excised, and pathologic evaluation confirmed the diagnosis of synovial cyst. CONCLUSION: The correct radiographic diagnosis of this patient was not made because of lack of experience with such lesions in this location. The authors hope that this case report helps raise the awareness of clinicians in considering this diagnosis when facing similar radiographic presentation.

Aged↗
PubMed1996

Expression of vascular endothelial growth factor in pediatric and adult cerebral arteriovenous malformations: an immunocytochemical study.

Children and adults may differ with respect to their cerebral vasculature in both normal and pathological states. The authors have identified four pediatric patients in whom a cerebral arteriovenous malformation (AVM) recurred after surgery for removal of the AVM and in whom a normal postoperative angiogram had been obtained. This phenomenon has not been observed in adults. The propensity to regrow a cerebral AVM may reflect a less mature cerebral vasculature and a disregulated angiogenic process. Recently, attention has focused on vascular endothelial growth factor (VEGF) as a possible general mediator of angiogenesis in development and neoplasia. A retrospective immunocytochemical analysis of VEGF expression in AVM tissue was conducted to test the hypothesis that VEGF expression may be found in association with the regrowth of AVMs. The results demonstrate a high degree of astrocytic VEGF expression in four (100%) of four specimens from the initial operation in the children with recurrent AVMs as compared to one (14%) of seven nonrecurrent AVMs in the pediatric and two (25%) of eight adult specimens. All of the specimens from the first operation of the recurrent group demonstrate a clear association of cellular immunoreactivity to the abnormal blood vessels, a relationship that was not observed in the specimens from the nonrecurrent groups. These observations indicate that a humoral mechanism mediated by VEGF may play a role in AVM recurrence.

Adult↗
PubMed1996

Pathology of cerebral metastases.

Important pathologic features of cerebral metastases include the route of spread of tumor cells to the brain, differences among metastases based on location in dura mater, leptomeninges, and brain parenchyma, differences based on primary tumor site, both known and unknown, the means of spread of metastases within the brain, and the brain's reactions to metastases. Immunohistochemistry and electron microscopy are increasingly used in the pathologic evaluation of cerebral metastasis.

Brain Neoplasms↗
PubMed1996

Mesenchymal chondrosarcoma in anterior skull base: case report.

We report the case of a 16-year-old boy who presented with mesenchymal chondrosarcoma involving the ethmoid sinus, right orbit, nasal cavity, and anterior cranial fossa. The tumor was totally resected by craniofacial surgery; the patient's postoperative course was uneventful. Microscopically, the tumor was composed of highly cellular undifferentiated small cells, alternating with zones of cartilaginous tissues. Mesenchymal chondrosarcoma is a rare, aggressive variant of chondrosarcoma, which might be encountered more frequently due to the advances in neuroimaging and surgical procedures.

Adolescent↗
PubMed1994

Altered synaptophysin-immunoreactive pattern in human olivary hypertrophy.

We examined the inferior olivary nucleus from four cases of olivary hypertrophy and six control cases immunohistochemically with an anti-synaptophysin (SYP) antibody. Our study revealed the altered SYP-immunoreactive pattern in the hypertrophied olives, consisting of an increased number of SYP-immunoreactive dots on neuronal cell bodies in spite of its decreased immunoreactivity in the neuropil. Because SYP is a marker protein for presynaptic vesicles, presynaptic terminals in the inferior olivary nucleus seem to change their distribution during the course of olivary hypertrophy.

Aged↗
PubMed1994

Electron microscopy of the blood-brain barrier in disease.

The anatomical site of the blood-brain barrier (BBB) is at the capillary endothelium mainly, with some contribution from astrocytes. Electron microscopic observations of endothelial cells and perivascular astrocytes comprising the BBB in brain edema and other pathological conditions are reviewed in this article. The tight junctions of cerebral endothelial cells open under several conditions such as infusion of hyperosmolar solutions. Pinocytotic vesicles increase under various pathological conditions and fenestrae appear in blood vessels of certain brain tumors and several non-neoplastic lesions. Inflammatory cells penetrate between or through endothelial cells. In long standing lesions, endothelial cells containing various tubular structures such as Weibel-Palade bodies proliferate. Other alterations include surface infoldings of endothelial cells and fluid diffusion through damaged endothelium. Astrocytic alterations include abnormal junctions between astrocytic processes in certain gliomas. In vivo and in vitro studies suggest that astrocytes maintain or develop certain functions of BBB. As the BBB is disrupted, edema fluid infiltrates the brain parenchyma. Because the white matter consists of nerve fibers without demonstrable junctions, it invades between nerve fibers. In the gray matter, expansion of the fluid is limited by complicated anatomical structures. In myelinated nerve fibers, edema fluid accumulates in five separate compartments of extracellular space.

Animals↗
PubMed1994

Immunocytochemical studies on synaptophysin in the anterior horn of lower motor neuron disease.

This report concerns the study of synaptophysin (SP) expression in the anterior horn of three cases of lower motor neuron disease (L-MND). All patients studied had anterior horn cell degeneration without neuropathological evidence of corticospinal tract degeneration. Spinal cords from six patients with no neurological disease served as controls. Immunocytochemical techniques were used. The results show that in L-MND there is decreased SP immunoreactivity of the anterior horn neuropil, but preservation of immunoreactive dots around the cell body and proximal processes, and the presence of some residual neurons in the affected gray matter that are surrounded by a dense accumulation of immunoreaction products. These findings resemble those of classical amyotrophic lateral sclerosis (ALS), indicating similarities in the distribution patterns of presynaptic terminals in the anterior horn of L-MND and classical ALS.

Adult↗
PubMed1994

Cerebral malaria in mice: demonstration of cytoadherence of infected red blood cells and microrheologic correlates.

To understand the microcirculatory events during cerebral malaria, we have studied the lethal strain of rodent Plasmodia, Plasmodium yoelii 17XL, originally described by Yoeli and Hargreaves in 1974. The virulence of P. yoelii 17XL is caused by intravascular sequestration of infected red blood cells (IRBCs), especially in the brain vessels and capillaries. This mouse model resembles human P. falciparum infection more closely than P. berghei ANKA infection since it shows little, if any, inflammation of the brain. In vivo microcirculatory studies on cytoadherence of IRBCs were performed using the cremaster muscle preparation, which is an easily accessible vasculature for intravital observations. Ex vivo assay of cytoadherence was carried out in the artificially perfused mesocecum preparation of the rat. The results in either preparation demonstrated cytoadherence of IRBCs that was restricted to postcapillary venules. Furthermore, the in vivo measurements showed the prevalence of cytoadherence in small-diameter (< 40 microns) venules in accordance with the local wall shear rates. The parasitized animals demonstrated significantly reduced red blood cell velocities and wall shear rates in the small-diameter postcapillary venules of the cremaster. The relationship between cytoadherence and venular wall shear rates was also reflected in the inverse correlation between the number of adhered cells and the venular diameter in the ex vivo mesocecum preparation. In the ex vivo preparation, cytoadherence of IRBCs was accompanied by a higher peripheral resistance. Transmission electron microscopy of the cremaster muscle and brain tissues showed a tight association of IRBCs with the endothelium of small venules. These observations demonstrate that cytoadherence of P. yoelii 17XL-infected mouse red blood cells is very similar to that of P. falciparum-infected cells. Thus, this model should allow a detailed analysis of the molecular mechanisms involved in the generation of cerebral malaria by cytoadherence of the infected red blood cells to the vascular endothelium.

Animals↗
PubMed1993

Central nervous system pathology in pediatric AIDS.

Children with AIDS frequently have neurological manifestations due to complications of immunodeficiency or intrinsic effects of human immunodeficiency virus type 1 (HIV-1) on the central nervous system (CNS). The most common neurological disorders not directly related to HIV-1 infection include cerebrovascular disease and lymphoma. Global anoxic-ischemic and necrotizing encephalopathies are frequent, while CNS hemorrhages and arteriopathies are less frequent. Opportunistic CNS infections are uncommon, limited predominantly to monilial and cytomegaloviral encephalitides. Only a few cases of CNS toxoplasmosis have been reported in children. CNS lymphomas often occur in the setting of systemic polymorphous, polyclonal B-cell proliferations that have been associated with Epstein-Barr virus infection. Intrinsic effects of HIV-1 on the CNS include microcephaly, diffuse gliosis, basal ganglia mineralization, HIV encephalitis, and corticospinal tract degeneration. Although viral antigens can be detected in microglia and multinucleated cells in HIV encephalitis, most of the CNS effects of HIV-1 infection cannot be attributed to detectable levels of viral antigen, suggesting that the pediatric CNS is unusually susceptible to low-level HIV-1 infection or to systemic effects of HIV-1 infection, possibly mediated by soluble factors, including the inflammatory cytokines, interleukin-1 beta, and tumor necrosis factor-alpha, which have been shown to be increased in serum and cerebrospinal fluid of children with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Cerebral infection complicating systemic aspergillosis in acute leukemia: clinical and radiographic presentation.

Cerebral fungal infection is becoming an increasingly recognized entity in immunocompromised patients on post-mortem examination. In order to determine the frequency of clinically significant cerebral fungal infection and define its clinical characteristics in a cohort of immunocompromised patients at high risk of fungal infection, the records of 118 patients with acute leukemia were examined for 57 clinical and laboratory features. The characteristics of 26 patients with systemic aspergillosis and acute leukemia were compared to 92 patients with acute leukemia in a control group. Eight of 118 patients (7%) had cerebral infection (seven Aspergillus, on Candida). Patients with systemic aspergillosis were more likely than patients in the control group to have focal neurologic findings (p = 0.02), confusion (p = 0.04), and abnormal computerized tomography (CT) of the brain characterized by single or multiple, enhancing or non-enhancing hypodense lesions (p = 0.02). Patients with systemic aspergillosis were more likely to die in complete remission than patients in the control group (p = 0.003); three of six patients with aspergillosis who died in remission expired as a consequence of cerebral infection. Cerebral infection complicated systemic Aspergillus infection in seven of 26 patients (27%), versus one of 16 patients with systemic Candida infection (6%) (p = NS). The authors conclude, therefore, that systemic aspergillosis complicating acute leukemia is more likely to be associated with confusion, focal neurologic findings, and abnormal CT scan of the brain, and that these findings suggest the presence of cerebral infection. In addition, cerebral infection commonly complicates the course of systemic aspergillosis, and is a significant cause of morbidity and mortality in patients with acute leukemia. A high index of suspicion is needed to insure early diagnosis and appropriate therapy, particularly in those who achieve remission of their leukemia.

Aspergillosis↗
PubMed1992

Ultrastructural and immunohistochemical studies on ballooned cortical neurons in Creutzfeldt-Jakob disease: expression of alpha B-crystallin, ubiquitin and stress-response protein 27.

This report concerns ultrastructural and immunohistochemical studies on ballooned neurons of ten patients with Creutzfeldt-Jakob disease (CJD). While abundant ballooned neurons and severe white matter degeneration was seen in six Japanese cases, only occasional ballooned neurons and no white matter degeneration was observed in four cases from the files of Montefiore Medical Center. Ultrastructurally, the ballooned neurons contained granule-coated fibrils of 25 to 40 nm in width and 10-nm neurofilaments. The immunohistochemical studies revealed that most ballooned neurons expressed alpha B-crystallin, with deposits of reaction products observed in the cytoplasm. A similar intracellular staining pattern was also seen with the antibody to phosphorylated neurofilament proteins (pNFP). Although the proportion of stained ballooned neurons was less, a positive reaction was also observed with antibodies against ubiquitin, stress-response protein 27 (srp 27) and synaptophysin, but not with an antibody to srp 72. Our findings suggest that expression of pNFP and synaptophysin by ballooned neurons may reflect axonal impairment and that the presence of alpha B-crystallin, srp 27 and ubiquitin may be related to the degenerative processes that neurons undergo in CJD.

Aged↗