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Biomedical subjects

V Jay

Publications and source records attributed to V Jay.

At least 109 records · Page 6Linked to original sources
PubMed1994

Pediatric malignant glioma with tubuloreticular inclusions and MYCN amplification. Report of a case with immunohistochemical, ultrastructural, flow cytometric, karyotypic, and Southern blot analysis.

BACKGROUND: The authors described unusual pathologic features in a left frontal lobe malignant glioma in a 31/2-year-old boy. The pathology was similar in the initial excision and two subsequent recurrences at 9 and 11 months and at autopsy, when extensive subarachnoid spread was noted. METHODS: The tumor was studied by conventional histology, immunohistochemistry, flow cytometry, transmission electron microscopy (TEM), immune electron microscopy (IEM), and cytogenetic and Southern blot analysis. RESULTS: The tumor revealed two different histologic patterns. One component showed large cells with eosinophilic cytoplasm, vesicular nuclei with prominent nucleoli, eosinophilic perinuclear inclusions, and immunoreactivity for glial fibrillary acidic protein (GFAP) and vimentin. The other component consisted of undifferentiated cells with hyperchromatic nuclei and scanty cytoplasm. By TEM, the perinuclear aggregates were composed of tubuloreticular inclusions, which were also observed in endothelial cells within the tumor vasculature. By IEM, the intermediate filaments in the tumor cell cytoplasm were decorated with GFAP. Flow cytometric results revealed a marked increase in the S-phase (48%), whereas cytogenetic analysis of short-term cultures showed an abnormal karyotype containing marker chromosomes and double minutes. In the second resection, additional karyotypic abnormalities were noted, including 1p- and several additional markers. The first and second resections showed MYCN amplification by Southern Blot analysis in the 60- to 80-fold range. CONCLUSIONS: This tumor presents unique histologic, ultrastructural, and cytogenetic findings as well as MYCN amplification that is notable for a pediatric malignant glioma. Tubuloreticular inclusions were a prominent feature in this tumor, which again is unique for a glioma.

Blotting, Southern↗
PubMed1994

A case of unilateral congenitally enlarged extraocular muscles.

BACKGROUND: Enlargement of extraocular muscles is an uncommon finding in children. Little has been written in the literature about possible causes. METHODS: The authors present the clinical findings of a young girl who had unilateral congenitally enlarged extraocular muscles at 8 months of age. She underwent computed tomography (CT) and magnetic resonance imaging (MRI) scans, systemic assessment, and extraocular muscle biopsy to determine a cause for the enlarged muscles. RESULTS: The patient had a unilateral left esotropia and hypotropia at birth that was nonprogressive. High-resolution CT and MRI scans showed enlargement of the left inferior rectus, lateral rectus, and medial rectus muscles. Strabismus surgery undertaken at 2 years of age showed that the affected muscles were restricted on forced duction testing but were macroscopically normal in appearance. A biopsy specimen of the left lateral rectus muscle was processed for histologic, histochemical, and electron microscopic studies, but no abnormal pathologic findings were found. CONCLUSION: This patient's constellation of findings appears to be unique: it does not follow any previously reported pattern of disorders of extraocular muscle enlargement.

Biopsy↗
PubMed1994

Capnocytophaga keratitis. A clinicopathologic study of three patients, including electron microscopic observations.

BACKGROUND: Histopathologic studies of this unusual keratitis caused by Capnocytophaga species have not been reported previously. METHODS: The authors report the light microscopic and ultrastructural findings of three patients with a distinctive necrotizing keratitis caused by an anaerobic gram-negative bacillus. In three patients, ages 19, 81, and 91 years, a necrotizing stromal keratitis developed; two of these patients had a previous penetrating keratoplasty for pseudophakic bullous keratopathy. The first patient did not have ocular surgery previously and was treated initially for presumed Acanthamoeba keratitis. RESULTS: By light microscopy, all three keratectomy specimens were strikingly similar and showed a necrotizing and/or suppurative stromal keratitis displaying myriad slender, fusiform, gram-negative bacilli located anterior to Descemet's membrane and extending into the deep corneal stroma, assuming a "picket fence" appearance. Cultures of the cornea in case 1 grew Capnocytophaga ochracea. For the remaining two patients, a diagnosis presumptively was made based on characteristic histopathologic features. Results of electron microscopic examination showed numerous bacilli that were mostly extracellular; occasional organisms were phagocytosed by macrophages. CONCLUSION: The histopathologic features of Capnocytophaga keratitis are unique; therefore, a presumptive diagnosis can be made based on the morphology and location of the bacilli in the keratectomy specimens. To the authors' knowledge, this is the first study describing the typical histopathologic and electron microscopic findings of Capnocytophaga keratitis.

Adult↗
PubMed1994

Fiber-type differentiation by myosin immunohistochemistry on paraffin-embedded skeletal muscle. A useful adjunct to fiber typing by the adenosine triphosphatase reaction.

The myofibrillar adenosine triphosphatase reaction has been traditionally used to delineate fiber types in skeletal muscle biopsy specimens. At a pH of 9.4, the type 2 fibers are stained and the type 1 fibers remain unstained, thus permitting a clear distinction between the two fiber types and allowing morphometric assessments of fiber size, fiber diameter, and fiber ratios. However, this histochemical reaction requires frozen muscle tissue and is not feasible in situations when only paraffin-embedded tissue is available. We describe a useful alternative to determine fiber types in skeletal muscle specimens by myosin histochemistry on formalin- or Bouin-fixed, paraffin-embedded tissue. Our experience with over 300 muscle samples from both surgical and autopsy specimens indicates that myosin immunohistochemistry also provides accurate assessments of fiber types, fiber sizes, and fiber ratios. The most significant advantage of this method is its applicability to nonfrozen material, thus permitting fiber-type distinction in situations when frozen tissue is unavailable and facilitating retrospective analysis on archival material.

Humans↗
PubMed1994

Development of anaplastic changes in low-grade astrocytomas of childhood.

The authors present their experience with six children who developed anaplastic astrocytomas after receiving treatment for low-grade astrocytomas. Five children were from a series of 55 children with optic chiasmatic-hypothalamic gliomas who have been studied since 1976. The sixth child initially had a low-grade astrocytoma of the thalamus. The mean age of the children at initial presentation was 5.3 years. Five children were treated with surgery and radiation therapy; one child with a chiasmatic-hypothalamic glioma received radiation therapy alone. The amount of external radiation therapy used in all children was 50-52.5 Gy delivered in standard fractionations over approximately 6 weeks to include the volume of the original tumor plus a margin of 2 cm. The time to anaplastic transformation varied between 2 and 10 years (mean, 6.4 years). At tumor recurrence, the children had seizures or symptoms and signs of raised intracranial pressure. The location of the second tumor in all patients was either at the primary site or within the field of radiation therapy. Five of the six children underwent a second craniotomy and subtotal resection of their malignant gliomas. One child had positive cerebrospinal fluid cytology and multiple intraspinal metastatic tumor nodules detected by magnetic resonance imaging. On histopathological examination, four children had anaplastic astrocytoma, and two had glioblastoma multiforme. Four of the six children have died of their anaplastic astrocytomas (mean time from diagnosis of anaplastic astrocytoma to death, 10 months). Two children underwent chemotherapy and spinal irradiation for their anaplastic astrocytomas, and are currently alive and undergoing treatment. The possible mechanisms by which anaplastic tumors have developed in children treated previously for low-grade astrocytomas is discussed. The data suggest that radiation therapy may have played an integral role in the genesis of anaplastic astrocytomas in these children.

Astrocytoma↗
PubMed1993

An unusual patient with the neonatal Marfan phenotype and mitochondrial complex I deficiency.

We report the case of a 16-month-old male with the neonatal appearance of Marfan syndrome (NMS), with dolichocephaly, a long midface, deep-set eyes, arachnodactyly, dislocated lenses and carciovascular abnormalities. The presence of persistent lactic acidosis led to studies which disclosed mitochondrial complex I deficiency. We speculate that this unusual association may be due to the combination of an inherited mutation affecting complex I activity along with a de novo mutation disrupting the corresponding locus and an adjacent NMS locus on the homologous autosome. The possibility that the phenotype observed in this patient is directly due to the mitochondrial defect cannot be excluded.

Electron Transport Complex I↗
PubMed1993

Neuronal heterotopia with capillary penetration of neurons and cortical dysplasia in a patient with complex partial seizures. Case report.

Unusual pathological findings were encountered in a temporal lobectomy specimen from a 9-year-old boy with intractable complex partial seizures. Magnetic resonance imaging revealed an enlarged left temporal lobe, with diffuse high signal intensity over the cortex and poor gray-white differentiation on T2-weighted imaging; single-photon emission computerized tomography showed decreased blood flow. Active epileptiform discharges were identified in the left temporal lobe with focal slow waves and generalized epileptiform paroxysms. Pathologically, the cortex revealed changes of focal cortical dysplasia with extensive disorganization of neuronal morphology, layering, and orientation as well as focal polymicrogyria. The cortical-white matter junction was indistinct with extensive neuronal heterotopias in the white matter. Large pale balloon cells akin to those seen in tuberous sclerosis were found scattered within the cortex and white matter. The most striking finding was that of a heterotopic nodule in the white matter, which revealed abnormal neurons with penetration of cell bodies by capillaries. Ultrastructurally, there were no degenerative changes in these neurons, and this unusual phenomenon is attributed to a developmental disturbance affecting neuronal, glial, and vascular elements.

Brain Neoplasms↗
PubMed1993

Pathology of temporal lobectomy for refractory seizures in children. Review of 20 cases including some unique malformative lesions.

Significant pathological abnormalities were encountered in a series of 20 temporal lobectomies in children with intractable complex partial seizures. In particular, "dual pathology" (mesial temporal sclerosis with other lesions) was found rather than mesial temporal sclerosis as the only lesion. Unusual pathological findings included capillary penetration of neurons in a neuronal heterotopia in one patient, and foci of extensive cortical disorganization in some cases of mixed tumors and gangliogliomas. A high proportion of neuronal migration disorders was also seen with overlapping pathological features between cortical dysplasia and tuberous sclerosis. In this correlative clinical, radiological, electroencephalographic, and pathological study, some of the pathological lesions in children did not fit the classical categories of neoplasia and malformation and transitional forms were rarely encountered.

Adolescent↗
PubMed1993

Increased mitotic activity as a negative prognostic indicator in pleomorphic xanthoastrocytoma. Case report.

Pleomorphic xanthoastrocytoma is a recently characterized neoplasm with a favorable prognosis despite aggressive histological features. The authors report a case of pleomorphic xanthoastrocytoma that recurred 4 years after complete gross resection. The original tumor exhibited histological features characteristic of this neoplasm, but up to 4 mitoses/10 high-power fields were present focally. The recurrent tumor contained small foci of classical pleomorphic xanthoastrocytoma, but consisted predominantly of glioblastoma multiforme. Transitional zones contained nests of glial fibrillary acidic protein (GFAP)-immunopositive cells surrounded by delicate collagenous and reticulin-rich septa. Electron microscopy of the transitional zone showed continuous basal lamina investing cells containing bundles of intermediate filaments. These were GFAP-positive by immunogold electron microscopy, confirming the astrocytic nature of pleomorphic xanthoastrocytoma. This example illustrates the capacity of this tumor to evolve into glioblastoma. The indolent clinical behavior of most pleomorphic xanthoastrocytomas is evident from a literature review, which confirms the prolonged survival of many patients after onset of symptoms. Completeness of excision, subjectively assessed at surgery, did not influence the risk of recurrence or survival up to 10 years after initial resection. Postoperative radiotherapy did not improve survival, but may reduce the probability of recurrence; more studies are needed to corroborate this finding. The data compiled herein support the designation of pleomorphic xanthoastrocytoma as a distinct astrocytic neoplasm with a favorable prognosis. An increased mitotic rate has not previously been correlated with a worse outcome, and should not be used to exclude this diagnosis. However, anaplastic transformation of pleomorphic xanthoastrocytoma confers a much worse prognosis, and this case suggests that increased mitotic activity may be a negative prognostic indicator since it may herald subsequent anaplastic transformation.

Astrocytoma↗
PubMed1992

Inclusion body myositis with abundant ring fibers.

A 37-year-old male presenting with a 7-year history of leg weakness was found to have moderate weakness confined to the quadriceps and myopathic changes on electromyography. Serum creatine phosphokinase was 2130 units/liter. Biopsy of the quadriceps muscle revealed an inflammatory myopathy with cytoplasmic and nuclear filamentous inclusions characteristic of inclusion body myositis. An unusual finding was the large proportion of ring fibers along with severe atrophy and fibrosis. The pathogenesis of the ring fibers in this setting is discussed.

Adult↗
PubMed1992

"Reducing body"-like inclusions in skeletal muscle in childhood-onset acid maltase deficiency.

Unusual inclusions with some of the features of "reducing bodies" were encountered in the skeletal muscle biopsy of a 2.5-year-old boy with childhood-onset acid maltase deficiency. The biopsy revealed a vacuolar myopathy with lysosomal storage of glycogen and eosinophilic refractile inclusions in myofibers, which appeared dark blue with the menadione-nitroblue tetrazolium reaction. The significance of the association of inclusions with reducing properties in the setting of acid maltase deficiency is discussed.

Child, Preschool↗
PubMed1992

Prepontine cyst lined by respiratory epithelium with squamous metaplasia: immunohistochemical and ultrastructural study.

An 8.5-year-old female presented with multiple episodes of aseptic meningitis and was found to have a cystic lesion in the prepontine region. Microscopic examination revealed a respiratory-type epithelium with squamous metaplasia. Like its normal analogue in the respiratory tract, the epithelium of these intracranial cysts can undergo squamous metaplasia when chronically irritated. The ultrastructural and immunohistochemical characteristics of the transition from ciliated epithelium to squamous metaplasia are described.

Brain Diseases↗
PubMed1992

Experimental verocytotoxemia in rabbits.

The clinicopathologic effects of intravenously administered purified verocytotoxin 1 (VT1; Shiga-like toxin 1) in 2-kg male rabbits was studied. The 50% lethal dose was 0.2 micrograms of protein per kg of body weight (2 x 10(4) 50% cytotoxic doses per kg). The clinical features included nonbloody diarrhea and a progressive flaccid paresis, usually culminating in death. The histopathology was characterized by edema and hemorrhage in the mucosa and submucosa of the cecum and edema, hemorrhage, and neuronal necrosis in the brain and gray matter of the spinal cord. Thrombotic microangiopathy, the characteristic histopathologic renal lesion in the hemolytic-uremic syndrome, was also found to be the underlying lesion in verocytotoxemic rabbits. To determine the specific distribution of VT1 in rabbit tissues, purified 125I-labelled VT1 was administered intravenously to 20 rabbits (both immunologically naive and VT1-immune rabbits). The highest specific uptake of 125I-VT1 was in the spinal cord, brain, cecum, colon, and small bowel in unimmunized animals but in the liver, spleen, and lungs in immune animals. Immunofluorescent staining of cecal and spinal cord tissues after intravenous administration of VT1 showed evidence of specific vascular endothelial cell binding of the toxin. The striking correlation of the central nervous system and gastrointestinal localization of 125I-VT1 with the sites of known histopathology is consistent with direct toxin-mediated injury to these tissues, initiated by the specific binding of VT1 to the vascular endothelium. We conclude that the vascular damage induced by VT1 in affected rabbit tissues is similar to that seen in the kidneys and other tissues in patients with verocytotoxin-producing Escherichia coli-associated hemolytic-uremic syndrome. This suggests that although the rabbit model fails to replicate human hemolytic-uremic syndrome, it is useful for studying the pathogenesis of the vascular lesions in verocytotoxin-producing E. coli-associated diseases.

Animals↗
PubMed1991

Idiopathic prolactin cell hyperplasia of the pituitary mimicking prolactin cell adenoma: a morphological study including immunocytochemistry, electron microscopy, and in situ hybridization.

Prolactin cell adenoma is the most frequently found lesion in surgically removed pituitaries of patients with hyperprolactinemia. However, in several instances, instead of prolactin cell adenoma, other lesions are encountered by morphological investigation. We report here the morphological findings in a patient with hyperprolactinemia who underwent transsphenoidal pituitary surgery for suspected prolactin cell adenoma. A morphological diagnosis of tumor could not be confirmed and massive diffuse prolactin cell hyperplasia was identified. The aim of this publication is to describe the lesion by histology, immunocytochemistry, electron microscopy, and in situ hybridization and to call attention to primary prolactin cell hyperplasia which can mimic prolactin cell adenoma.

Diagnosis, Differential↗
PubMed1991

Fulminant blastomycosis with blastomycotic infection of a cerebral glioma. Light microscopic and ultrastructural observations.

Except for isolated case reports, blastomycosis has not been identified as a significant problem in immunosuppressed patients. We describe an unusual case with blastomycotic infection of a cerebral glioma in a 56-year-old man who underwent radiotherapy for his tumor and died of fulminant blastomycotic pneumonia. This is believed to be the first reported case of Blastomyces dermatitidis infection of a cerebral glioma. The light microscopic and ultrastructural features of B. dermatitidis, the giant forms of which were encountered in our patient, are described, and thr role of immunosuppression due to steroid therapy in the pathogenesis of this fulminant infection are reviewed.

Blastomyces↗
PubMed1991

Transsphenoidal management of Rathke's cleft cysts. A clinicopathological review of 10 cases.

We report detailed data on 10 patients who underwent transsphenoidal microsurgical management of histopathologically confirmed Rathke's cleft cysts. Preoperatively, pituitary dysfunction was present in 90%, headaches in 80%, hyperprolactinemia in 70%, and visual interference in 40%. Computed tomography and magnetic resonance imaging had 90% and 100% sensitivity, respectively, in disclosing the lesion. The mean follow-up duration was 22 months. There was no mortality. The only morbidity was sustained diabetes insipidus in one case. Resolution or improvement in preoperative dysfunction occurred in the majority of patients: headaches in 100%, visual deficits in 75%, normalization of hyperprolactinemia in 83%, and reversal of panhypopituitarism in 33%. We conclude that Rathke's cleft cysts can be managed safely and effectively with transsphenoidal drainage and partial excision of the wall.

Adult↗