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Biomedical subjects

V Jay

Publications and source records attributed to V Jay.

At least 73 records · Page 4Linked to original sources
PubMed1998

The effects of postoperative continuous passive motion on peripheral nerve repair and regeneration. An experimental investigation in rabbits.

The effects of continuous passive motion (CPM) on nerve regeneration following nerve repair were investigated. In 26 rabbits, the medial popliteal nerve was transected and microsurgically repaired. Half of the animals were treated with cast immobilization and the rest with 70 degrees arc CPM. Both treatments were discontinued on day 14. After sacrifice on day 100, no animal showed separation at the suture line. Mean nerve conduction velocity was slightly slower in the CPM than in the immobilization group. Mean fibre density was also slightly less in the CPM group but the difference was not significant. Mean fibre diameters, fibre diameter distributions, and soleus-muscle wet weights were similar in the two groups.

Action Potentials↗
PubMed1998

Severe classical congenital muscular dystrophy and merosin expression.

It has been suggested that patients with autosomal recessive merosin deficient congenital muscular dystrophy (CMD), as opposed to the merosin positive cases form a homogeneous subgroup of a clinically more severe form of CMD. We examined merosin expression in muscle biopsies from five children with the severe classical form of CMD. Merosin deficiency was found only in 1 patient, a 6-year-old female, with abnormal brain myelination. However, her initial biopsy did not reveal the classical picture of dystrophy. The four merosin positive cases exhibited severe muscle weakness but their brain imagings were normal. There were no familial cases, except for the mother of 1 patient who had a milder form of the disease, suggesting an autosomal dominant mode of inheritance. In contrast to previous reports, the merosin deficient CMD cases were rare in our group. Furthermore, merosin positive cases were also associated with severe phenotype suggesting that a severe phenotype is not exclusive to merosin deficient cases. Finally, the absence of merosin in a neonate with hypotonia and weakness can be helpful in making a definitive diagnosis of CMD, even though the dystrophic process may not be evident yet and histology may be non-specific.

Child↗
PubMed1998

Focal plaque of demyelination mimicking cerebral tumor in a pediatric patient.

Focal, demyelinating lesions of the cerebrum mimicking brain tumors are a rare phenomenon, and even rarer in a pediatric population. We document the case of a 14-year-old female whose clinical, radiological and operative findings were strongly suggestive of glioma. However, histopathology revealed a demyelinating process. This case is significant as the lesion could not be distinguished from a glioma at any time in the presentation. At 41 months follow-up, the patient remains stable without further evidence of demyelination in other areas of the brain. Such a case suggests a cautious note for the pediatrician when presented with a similar patient and illustrates the importance of consideration of a demyelinating lesion in the differential diagnosis of a mass lesion in a pediatric population.

Adolescent↗
PubMed1998

Congenital cytoplasmic body myopathy with survival motor neuron gene deletion or Werdnig-Hoffmann disease.

A 5-week-old boy became rigid and developed cardiac arrest after receiving succinylcholine. He was resuscitated and ventilated but died at 5 months. Muscle biopsy demonstrated no neurogenic features and numerous cytoplasmic bodies, suggesting the possibility of congenital myopathy with cytoplasmic bodies. However, molecular analysis revealed a homozygous deletion of exons 7 and 8 of the survival motor neuron (SMN) gene, suggesting that the patient had Werdnig-Hoffmann disease. We recommend that every patient with congenital cytoplasmic body myopathy be tested for SMN gene deletion.

Biopsy↗
PubMed1997

Experimental autoimmune uveitis in HLA-B27 transgenic mice.

The major histocompatibility complex (MHC) gene, HLA-B27 is strongly associated with auto-immune uveitis and spondyloarthropathies in humans. Experimental mouse models of autoimmune uveitis involve systemic immunization with the retinal autoantigen interphotoreceptor retinoid binding protein (IRBP). To assess possible roles of HLA-B27 in autoimmune uveitis, as well as to investigate a possible new animal model of human uveitis, inbred strains of C57BL/6 and C57BL/6 possessing the human HLA-B27 or HLA-A2 transgene were immunized with IRBP emulsified in complete Freund's adjuvant (CFA). Dilated eye examinations were performed to assess the timing and clinical course of any ensuing uveitis. Mice were sacrificed 3 to 4 weeks postinjection and the eyes submitted for histopathologic analysis. CFA alone did not produce any clinical uveitis. Fifty percent of eyes from the background C57BL/6 strain developed uveitis as early as 10 days postinjection. Of the eyes demonstrating uveitis, an average clinical score of 2.5 was present. Pathologically, a moderate scleritis and anterior uveitis was present. Fifty percent of A2 transgenic eyes developed uveitis as early as 14 days postinjection with an average clinical score of 2.0. Pathologically, a mild vitritis was present. Uveitis developed in only 20% of B27 transgenic mice and reached a peak on day 28. The average EAU score in diseased animals was 4.5. A dense retinitis and panuveitis was associated with severe vitritis. We conclude that the presence of the B27 gene is associated with a decreased incidence and slower rate of onset of EAU following immunization with IRBP; however, EAU may be more severe in the HLA-B27 expressing animals who do develop disease.

Animals↗
PubMed1997

Coexistence of hemimegalencephaly and chronic encephalitis. Detection of cytomegalovirus by the polymerase chain reaction.

We report the extraordinary association of hemimegalencephaly with chronic encephalitis and cytomegalovirus (CMV) positivity in a 5-month-old infant with intractable seizures and a left hemisphere resection. Microscopy revealed a severe neuronal migration disorder (NMD) with fusion of gyri, marked disarray of neuronal lamination, neuronal gigantism and extensive neuronal heterotopias. Also widespread were microglial nodules, gliosis and nodular calcifications and some foci of frank necrosis with calcification. Occasional perivascular and leptomentingeal lymphocytic infiltrates were present. No viral inclusions were identifiable. Polymerase chain reaction on multiple specimens showed unequivocal CMV positivity. In intrauterine CMV infection. NMDs such as polymicrogyria are well recognized, but the association of hemimegalencephaly with CMV infection has not previously been described. Our finding of chronic encephalitis with CMV positivity and hemimegalencephaly in the same patient raises questions about the role of CMV in the etiopathogenesis of the NMD.

Brain↗
PubMed1997

Intracranial and spinal metastases from a ganglioglioma with unusual cytogenetic abnormalities in a patient with complex partial seizures.

We describe an unusual clinical presentation of a ganglioglioma in a patient with complex partial seizures. The patient underwent a right temporal lobectomy with subtotal tumor resection at age 15 years, followed by a complete resection 1 year later. Follow-up MRI scan a year later documented recurrence and leptomeningeal dissemination. Another biopsy was performed. Pathological examination revealed similar histology in all three resections, with a ganglioglioma showing no evidence of anaplasia. The tumor exhibited a number of karyotypic abnormalities, notably, a paracentric inversion of chromosome 7. In summary, despite lacking anaplastic features by conventional histological criteria, this ganglioglioma showed an unsusual karyotype and demonstrated radiological evidence of widespread dissemination.

Adolescent↗
PubMed1997

Histological and ultrastructural analysis of six colloid cysts in children.

Although colloid cysts of the third ventricle are unusual in children, we have recently encountered six examples. Histologically they were lined by cuboidal, pseudostratified or columnar ciliated and mucous-secreting epithelial cells. Two cases showed small microcysts within the fibrovascular stroma surrounding the main cyst. The outermost layer consisted of a glial-ependymal envelope, in keeping with the postulated supraventricular origin of colloid cysts. Scanning electron microscopy showed 10-40% ciliated cells, and no ballooning of non-ciliated cells. Aspiration of cyst contents was performed in three patients, two of whom subsequently required surgical resection 4 months and 8 years after drainage, respectively. In adults colloid cysts may be asymptomatic, whereas in children they have not been documented as incidental findings at autopsy. Two of our six cases died, both before a diagnosis was established. A colloid cyst of the third ventricle must be included in the evaluation of acute neurological deterioration in children, in whom they are more frequently lethal.

Adolescent↗
PubMed1997

Ubiquitin-immunoreactive granular inclusions in neuronal migration disorders.

This report describes novel ubiquitin-immunoreactive inclusions in neurons in 3 out of 27 patients with neuronal migration disorders (NMDs). One patient was pathologically diagnosed as having cortical microdysgenesis, and the other two were consistent to have polymicrogyria. The inclusions were present in the perikaryon as compact granular structures, 0.5-2 microns in diameter. Since ubiquitin acts as a cellular scavenger and has a crucial role in selective protein degradation, the presence of ubiquitin-immunoreactive inclusions suggests that altered or abnormal proteins may accumulate in neurons in NMDs, although the nature of accumulated proteins remains unknown.

Adolescent↗
PubMed1997

Acute obstructive hydrocephalus and sudden death in children.

STUDY OBJECTIVE: Sudden death from obstructive hydrocephalus related to intracranial neoplasms has rarely been reported in the pediatric literature. We sought to review the presenting signs and symptoms of acute hydrocephalus resulting from intracranial mass lesions to guide clinicians in the early identification of these potentially reversible lesions. METHODS: All cases of sudden unexpected death attributable to obstructive hydrocephalus that occurred from 1990 through 1994 at the Hospital for Sick Children, Toronto, were retrospectively reviewed. RESULTS: During the study period, seven children, ages 10 months to 15 years, died unexpectedly with acute obstructive hydrocephalus. Six children were apparently normal, and none had any known neurologic disease. All patients had a previously undiagnosed intracranial tumor located at a critical site for CSF flow: colloid cyst(n = 2), astrocytoma (n = 2), ependymoma (n = 2), suspected lymphoma (n = 1). Presenting features included vomiting in all cases, vomiting for longer than 2 weeks in three, headache in four, and lethargy in three. Five patients were misdiagnosed with viral illnesses, including three with presumed gastroenteritis who received intravenous rehydration therapy Focal gastrointestinal signs were absent. CONCLUSION: This case series highlights a life-threatening but misleading presentation of intracranial tumors. The diagnosis of gastroenteritis should be made cautiously when headache and vomiting occur in the absence of focal intestinal complaints. A history of vomiting exceeding a few days' duration warrants further investigation. Persistent lethargy should be considered a neurologic rather than a nonspecific clinical sign. Heightened awareness of this neurosurgical emergency may lead to swift intervention and potential reversibility with diversion of CSF.

Brain Neoplasms↗
PubMed1997

Giant cells in cortical tubers in tuberous sclerosis showing synaptophysin-immunoreactive halos.

We describe a characteristic pattern of immunoreactivity for synaptophysin in tuberous sclerosis. We analyzed cortical tubers from surgical specimens taken from six patients with tuberous sclerosis, which were obtained by surgical resections for the treatment of intractable seizures. The cortical tubers were characterized by blurred lamination of the cerebral cortex, hypercellularity, and gliotic changes. Neuropil in the cortex of cortical tubers showed reduced immunoreactivity for synaptophysin in all patients. 'Giant cells' were investigated in the cortex and white matter regions of cortical tubers. Some 'giant cells' had neuronal characteristics such as Nissl substance, a centrally placed chromatin-marginated nucleus, prominent nucleolus, positive immunoreactivity for microtubule-associated protein 2, and negative immunoreactivity for glial fibrillary acidic protein. Other 'giant cells' were indeterminate in cell type because they lacked Nissl bodies, distinct nucleolus, consistent immunoreactivity for microtubule-associated protein 2 and glial fibrillary acidic protein. Almost all 'neuronal giant cells' and some of the 'indeterminate giant cells' in the white matter showed intense immunoreactivity for synaptophysin: cell borders were surrounded by an intense immunoreactive halo. In conclusion, these immunohistochemical patterns for synaptophysin assist in characterizing these abnormal cells in the cortical tubers of patients with tuberous sclerosis.

Cerebral Cortex↗
PubMed1997

Positive epileptiform discharges in children with neuronal migration disorders.

Most epileptiform abnormalities show a negative polarity on EEG. Focal positive spike waves have rarely been identified in seizure disorders and are generally associated with physiological and neurological impairment. Results of EEG, computed tomography, MRI, and pathologic studies of 15 children with focal neuronal migration disorders who underwent surgery for refractory localization-related epilepsy were compared to examine the association between positive discharges and other findings. Subjects were studied both ictally and interictally by scalp EEG with the International 10-20 system and zygomatic or sphenoidal electrodes, and video EEG telemetry. The 5 children with positive discharges were significantly more likely to develop hemiparesis during the preoperative period (P < or = .025). Correlations were observed between positive discharges and lesions apparent on MRI situated around the rolandic fissure (P < or = .025). Children with positive discharges had a significantly less favorable outcome after surgical treatment (P < or = .025). Positive epilepti-form discharges in children with neuronal migration disorders may signal a more dysfunctional cortex leading to a focal neurological deficit or a more extended lesion than is detected on MRI. This would explain the less favorable outcome of seizures after surgery, since the epileptogenic areas and neuronal migration lesions cannot be completely resected.

Brain↗
PubMed1997

Evidence of abnormal differentiation in giant cells of tuberous sclerosis.

To characterize the giant cells in tuberous sclerosis, we examined immunoreactivity for nestin, vimentin, microtubule-associated protein 1B (MAP1B), MAP2, neurofilament, and glial fibrillary acidic protein (GFAP) in cortical tubers detected in brain specimens from 6 patients with tuberous sclerosis who had undergone surgical resection for treatment of intractable epilepsy. Giant cells with a neuronal appearance, "neuron-like giant cells," had a round centrally-placed nucleus with a single, prominent nucleolus, and Nissl substance was commonly present in cortex. These neuron-like giant cells demonstrated consistently strong immunoreactivity for neurofilament and MAP1B and occasional immunopositivity for nestin and vimentin and were rarely positive for GFAP. "Indeterminate giant cells," characterized by abundant cytoplasm, an absence of Nissl substance, and one or more eccentric nuclei, demonstrated consistent immunoreactivity for nestin, vimentin, and MAP1B and were rarely positive for neurofilament, but more than half displayed immunoreactivity for GFAP. These observations suggest that the indeterminate giant cells exhibit limited neuronal and inconsistent astroglial characteristics, implying aberrant cellular differentiation in tuberous sclerosis.

Cell Differentiation↗
PubMed1997

Management and outcomes of posterior fossa subdural hematomas in neonates.

OBJECTIVE: To review and analyze a contemporary series of 15 neonates who were treated for posterior fossa subdural hematomas (PFSDHs) during the era of computed tomography and magnetic resonance imaging. METHODS: A retrospective chart review identified all neonates with PFSDHs for whom neurosurgical consultations were obtained for treatment planning. RESULTS: There were nine male and six female patients. The mean gestational age was 39 weeks. Nine of the 15 mothers of the patients were primiparous. Instrument-assisted delivery (forceps and/or vacuum extractor) was undertaken for seven patients. The mean birth weight of the infants was 3165 g (range, 2160-3930 g). The mean 5-minute Apgar score was 7.5. Symptoms of PFSDH developed within the first 24 hours of life in 13 neonates. The predominant symptoms and signs were failure to thrive, irritability, seizures, apnea, and bradycardia. Lumbar punctures to rule out central nervous system sepsis were performed in six neonates. Hemograms revealed that six neonates were anemic with low hemoglobins, five had low platelets, and four had abnormal prothrombin and/or partial thromboplastin times at the time of diagnosis. Computed tomography established the diagnosis of PFSDH in all cases. Magnetic resonance imaging was performed for two neonates. The median time to diagnosis by imaging studies was 10 hours after birth. Surgical evacuation of the PFSDHs was performed in eight neonates. Seven neonates were followed conservatively with serial imaging studies. There was no mortality in either treatment group. Follow-up ranged from 2 to 10 years, with a mean of 4.5 years. Functional outcome assessment revealed that seven neonates were neurodevelopmentally normal, three were mildly delayed, two were moderately delayed, and three were profoundly delayed. In addition to traumatic causes of the PFSDHs, three neonates were observed to have coagulation disturbances at birth and one was observed at follow-up to have a posterior fossa medulloblastoma that had bled at birth. CONCLUSION: PFSDHs are rare but important lesions to diagnose early in the neonatal period. Surgery can be life-saving when performed in a timely manner for signs and symptoms of brain stem dysfunction. A search for an underlying cause predisposing to a PFSDH may, on occasion, reveal a coagulation disturbance or a neoplasm that will require additional therapeutic considerations.

Birth Injuries↗
PubMed1996

Oligodendrocytes in the adult rat spinal cord undergo radiation-induced apoptosis.

Mitotic-linked death is generally regarded as the mode of radiation-induced cell death, particularly in late-responding normal tissues, such as those found in the central nervous system. We have recently reported evidence for radiation-induced apoptosis in the central nervous system using the adult rat spinal cord model. Glial cells, but not neurons or vascular endothelial cells, appeared to undergo apoptosis within 24 h of irradiation. To further characterize the apoptotic process and the type of glial cells involved, a 2-cm segment of the adult rat cervical spinal cord was irradiated with single doses of 1-30 Gy and processed for detailed histological examination at 0, 4, 8, 12, 16, and 24 h after irradiation. Apoptosis was assessed using standard morphological features under the light and electron microscopes and an in situ end labeling assay. A dose response for radiation-induced apoptosis was observed over a dose range of 1-30 Gy, with the peak response at 8 h after irradiation. At 8 h after a 22-Gy irradiation, 96.1% of the apoptotic cells showed positive immunohistochemical staining with Leu-7, a specific marker for oligodendrocytes; only 4.4% of apoptotic cells were positive for Ricinus communis agglutinin-1 (a marker for microglia), and none were positive for glial fibrillary acidic protein (a marker for astrocytes). A significant decrease in the total glial cell density was observed at 24 h after irradiation with 22 (11%) or 30 Gy (14%) but not with 8 Gy. This was due primarily to a decrease in the oligodendroglial density (24%, 22 Gy, P < 0.001; 19%, 30 Gy, P = 0.001), because no decrease in the astroglial population was observed. The duration of apoptosis was estimated to be approximately 1 h. We conclude that there is a depletion of the oligodendroglial population in the adult rat spinal cord within 24 h after irradiation and that the mode of this radiation-induced cell death is apoptosis.

Animals↗
PubMed1996

Terminal deletion of the long arm of chromosome 3 [46,XX,del(3)(q27-->qter)].

We report on a terminal deletion of the long arm of chromosome 3 [46,XX,del(3)(q27-->qter)] in a female newborn infant who died 45 hours after delivery and had multiple congenital abnormalities including bilateral anophthalmia, congenital heart disease, and abnormal genitalia. The findings are compared to those of four previously reported cases with terminal del (3q).

Abnormalities, Multiple↗