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At least 667 records · Page 37Linked to original sources

PubMed2002

Radiosurgical treatment of cavernous sinus meningiomas: experience with 122 treated patients.

OBJECTIVE: To evaluate the efficacy of gamma knife (GK) radiosurgery, in terms of neurological improvement and tumor growth control (TGC), for a large series of patients with cavernous sinus meningiomas. METHODS: Between February 1993 and January 2002, 156 patients with cavernous sinus meningiomas (35 male and 121 female patients; mean age, 56.1 yr) were treated with GK radiosurgery in our department. GK radiosurgery was used as a first-choice treatment for 75 of 156 patients and as postoperative adjuvant therapy for 81 of 156 patients (all with Grade I meningiomas). Eligibility criteria for radiosurgery were as follows: symptomatic meningiomas and/or documented tumor progression on magnetic resonance imaging scans, conditions of high operative risk, patient refusal of microsurgery or reoperation, tumor volume of <20 cm(3), and location no less than 2 mm from the optic pathways. RESULTS: Follow-up data for at least 12 months were available for 122 patients (median follow-up period, 48.9 mo). Clinical conditions were improved or stable for 118 of 122 patients (97%). Neurological recovery was observed for 78.5% of patients treated with GK radiosurgery alone and for 60.5% of patients treated with adjuvant therapy (P < 0.05). Adequate TGC was documented for 119 of 122 tumors (97.5%), with shrinkage/disappearance in 75 of 122 cases (61.5%) and no variation in volume in 44 of 122 cases (36%); the overall actuarial progression-free survival rate at 5 years was 96.5%. Tumor size regression was observed for 80% of patients with follow-up periods of more than 30 months, compared with 43.5% of patients with follow-up periods of less than 30 months (P < 0.0002). Radiosurgical sequelae were transient in 4 of 122 cases (3.0%) and permanent in 1 case (1%). CONCLUSION: For the follow-up periods in our series (median, >4 yr), GK radiosurgery seems to be both safe (permanent morbidity rate, 1%) and effective (97% neurological improvement/stability, 97.5% overall TGC, and 96.5% actuarial TGC at 5 yr). GK radiosurgery might be considered a first-choice treatment for selected patients with cavernous sinus meningiomas.

Adult↗

PubMed2004

Occipital hypometabolism demonstrated by positron emission tomography after temporal lobectomy for refractory epilepsy.

BACKGROUND: Epilepsy surgery involves well-planned discrete injury to the brain and may create visual deficits. This study seeks to evaluate the indirect effects of temporal lobectomy on brain metabolism by correlating visual field defects and glucose metabolism in the visual cortex of patients before and after undergoing epilepsy surgery. METHODS: A retrospective survey of 11 patients who had undergone temporal lobectomy for refractory epilepsy in a single institution from 1986 to 1989, and who had pre-lobectomy and post-lobectomy visual field examinations and F-18 2-fluorodeoxyglucose positron emission tomography (FDG-PET) as part of a standard comprehensive epilepsy surgery evaluation. The PET images were analyzed to provide a correlation with the visual field defects that developed after the temporal lobectomy. RESULTS: Occipital hypometabolism in the absence of structural lesions of the occipital lobe was noted in seven patients with contralateral visual field defects and in one of four patients without a visual field defect. FDG-PET studies in three patients repeated for as long as 20 months after lobectomy showed no significant change in the occipital hypometabolism pattern. CONCLUSIONS: Although the occipital cortex was not directly injured during temporal lobectomy, the resulting hypometabolism correlates with the clinical findings of visual field defects. The hypometabolism may be due to deafferentation after interruption of the optic pathways and appears to be persistent.

Adult↗

PubMedDate not supplied

Cyclophosphamide for the treatment of progressive low-grade astrocytoma: a Pediatric Oncology Group phase II Study.

PURPOSE: Results of a phase II trial of cyclophosphamide (CPM) for children with progressive low-grade astrocytoma are reported. PATIENTS AND METHODS: Fifteen patients with a median age of 39 months (range, 2 to 71) were included in this study. The tumors of 11 children were located in the optic pathway, hypothalamus, or thalamus. Four courses of intravenous CPM 1.2 g/m2 were administered every 3 weeks during the upfront window portion of this protocol. Subsequently, chemotherapy was to continue with CPM, vincristine, and carboplatin for 2 years. RESULTS: By study design, the first 14 patients were centrally reviewed after completion of the initial 4 CPM courses. Toxicity was primarily hematologic. One patients had a complete response, 8 had stable disease, and 5 had progressive disease (PD). The excessive number of children with PD prompted study closure. CONCLUSION: CPM as used in this protocol showed insufficient activity against astrocytoma to justify further patient accrual.

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

Inherited susceptibility for pediatric cancer.

The percentage of childhood cancers that are caused by a clearly inherited predisposition varies significantly from only a few percent to more than 50% with individual tumor types. Recent advances in genetic testing and studies of cohorts of cancer patients have demonstrated the likelihood of identifying a cancer susceptibility mutation for numerous childhood cancers. Inherited predisposition to cancer is frequently the result of dominant constitutional mutations in tumor suppressor genes, which can be inherited from an affected parent or occur de novo during gametogenesis. In this article, we review the childhood malignancies that are associated with at least a 10% likelihood of being caused by a genetic susceptibility to cancer and therefore warrant consideration for a genetic evaluation; these malignancies include retinoblastoma, adrenocortical carcinoma, atypical teratoid and malignant rhabdoid tumors, optic pathway tumors, juvenile myelomonocytic leukemia, malignant peripheral nerve sheath tumors, vestibular schwannomas, endolymphatic sac tumors, hemangioblastomas, medullary thyroid cancer, pheochromocytomas, and paragangliomas. Children with other malignancies may also warrant genetic evaluation if there is the co-occurrence of malignancy and two or more congenital anomalies, or malignancy and a significant family history of related cancers. We also review the importance of the correct genetic diagnosis in order to ensure appropriate treatment and ongoing cancer surveillance for the child with cancer and closely related family members (e.g., parents and siblings).

Child↗

PubMed2005

Ocular manifestations of multiple sclerosis.

PURPOSE OF REVIEW: Multiple sclerosis is an autoimmune demyelinating disorder of the nervous system that is commonly manifested by visual system involvement and that may initially present with ophthalmologic symptoms. This paper reviews recent findings regarding the ocular manifestations in multiple sclerosis. RECENT FINDINGS: Manifestations of multiple sclerosis in the eye include both the afferent and efferent visual pathways. Optic neuritis, the most common ocular manifestation of multiple sclerosis, may be the initial clinical disease manifestation. Recent long-term follow-up data show that most patients with demyelinating optic neuritis have an excellent prognosis for recovery of central visual acuity. Evidence is emerging, however, for significant and broad reduction in both contrast sensitivity and color perception in multiple sclerosis patients despite near-normal visual acuities. Ocular motor deficits in multiple sclerosis include internuclear ophthalmoplegia and nystagmus, resulting in diplopia, oscillopsia, blurred visual, loss of stereopsis, and reading fatigue. Multiple sclerosis also may be associated with ocular inflammatory diseases, in particular pars planitis and retinal periphlebitis. SUMMARY: Ocular findings may be initial manifestations of multiple sclerosis and may predict additional demyelinating events. Recognizing these syndromes and signs will help clinicians to properly evaluate the patient, formulate an appropriate differential diagnosis, be able to discuss the prognosis with the patient, and help develop an effective therapeutic plan.

Eye Diseases↗

PubMed2004

Genodermatoses 2003-2004.

PURPOSE OF REVIEW: Many genodermatoses have been linked in recent years to their respective genes. The underlying biology and integrative nature of these genes with other genes and organ systems is beginning to be understood. This paper reviews recent advances in neurocutaneous disorders, ectodermal dysplasias, and the phenomenon of revertant gene mosaicism. RECENT FINDINGS: In neurofibromatosis type 1, molecular assays are being developed to distinguish malignant from benign and premalignant lesions. Clinical mutation analysis for the NF1 gene has been problematic; a sensitive new assay using automated comparative sequence analysis may be helpful. Revision of clinical care guidelines is ongoing. New data for the prospective management of optic pathway gliomas is reviewed. The two genes that underlie tuberous sclerosis complex, tuberin and hamartin, lie at the center of an important signal transduction pathway with significant implications for pharmacologic treatment. Issues in genetic counseling for this highly variable disease are updated. Extensive progress has been made in understanding the basis of several forms of ectodermal dysplasia. Disorders caused by mutations in p63 and the connexin and NF-kappaB gene families will be reviewed. Finally, phenotypic in vivo amelioration of genodermatoses via revertant gene mosaicism will be discussed as a possible mechanism to be exploited in directed therapeutic approaches. SUMMARY: This paper reviews recent developments in the molecular and biologic bases of neurofibromatosis type 1, tuberous sclerosis, and ectodermal disorders related to p63 and the connexin and NF-kappaB gene families. The concept of revertant gene mosaicism is also discussed as a potential model for gene therapy.

Adolescent↗

PubMed2005

Spindle cell oncocytoma of the adenohypophysis: report of two recurrent cases.

The recently described "spindle cell oncocytoma of the adenohypophysis" is a very rare and often misdiagnosed entity. A benign biologic behavior has been suggested based on the absence of recurrences with a median follow-up of 3 years. Herein, we present 2 cases of recurrent spindle cell oncocytomas. One patient is a 71-year-old woman (case no. 1) and the other a 76-year-old man (case no. 2). Recently, both underwent transsphenoidal reexploration for recurrent "pituitary adenoma." Patient no. 1 had initial surgery 11 years ago with a recurrence after 3 years that was initially stable. Ultimately, a partial resection was performed after compression of optic pathways by the tumor, and approximately 1 year later, re-resection was carried out. Patient no. 2 had initial surgery 10 years ago with recurrence and resection after 3 years. He recently presented with a large mass that involved the pituitary fossa and base of the skull, with extension into the nasopharynx and nasal cavity. The primary and recurrent lesions of both cases showed similar architecture with interlacing fascicles of spindle cells that alternated with areas of epithelioid-like cells that exhibited eosinophilic, granular cytoplasm. Neoplastic cells were positive for vimentin, S-100 protein, and epithelial membrane antigen, and negative for glial fibrillary acidic protein, chromogranin, and pituitary hormones. Increased mitotic activity was noted in 1 lesion (case no. 2), although both cases had high Ki-67 indices (18% and 20%, respectively). The ultrastructural features of both cases were characteristic with intracytoplasmic accumulations of large mitochondria. The histopathologic features of these lesions are consistent with spindle cell oncocytoma of the adenohypophysis. In summary, we are reporting 2 cases of recurrent spindle cell oncocytoma of adenohypophysis with longer follow-up than previously published cases, suggesting the possibility of a more aggressive behavior than has been initially considered.

Adenoma, Oxyphilic↗

PubMedDate not supplied

Further studies of the central nervous system in canine giant axonal neuropathy.

The CNS of three further cases of canine giant axonal neuropathy (GAN) were examined. The axonal swellings were present in the distal portions of the spinal long tracts and their terminations in the cerebellar vermis; in the distal optic pathways; the nuclei of the habenulo-interpeduncular tract; certain thalamic relay nuclei and the cerebral cortex. The swellings were present both paranodally and internodally with the myelin sheath being attenuated or even absent. Excessive numbers of disordered 10 nm neurofilaments were the main constituent although mitochondria, membranous bodies, glycogen bodies and amorphous electron dense material also accumulated, particularly in the fasciculus gracilis. The neurotubules tended to form small subaxolemmal or intra-axonal islands. Complex interdigitations of oligodendroglia and axolemma were found in the affected areas. A small number of fibres in the rostral fasciculus gracilis showed marked proliferation of the smooth endoplasmic reticulum which may represent abortive attempts at regeneration. A small proportion of astrocytic processes were markedly enlarged with excessive whorling of the glial filaments. The accumulation of these various organelles in the non-terminal axon in the absence of mechanical obstruction suggests a defect in axoplasmic transport which may result from an energy failure as suggested in toxic neuropathies. The significance and pathogenesis of the glial filamentous changes and those reported in other cells in human GAN is at present uncertain.

Animals↗

PubMedDate not supplied

Progressive axonopathy: an inherited neuropathy of boxer dogs. 2. The nature and distribution of the pathological changes.

This report describes the neuropathology of progressive axonopathy (PA), an autosomal recessive inherited neuropathy of Boxer dogs, which affects CNS and PNS. The nerve roots contain numerous myelin bubbles and proximal paranodal axonal swellings containing vesicles, vesiculo-tubular profiles and disorganized neurofilaments. The myelin sheath overlying such swellings is often attenuated. As the disease develops there are progressive changes in the myelin sheath with thinning at paranodal and internodal locations, loss of myelin from lengths of axon and the formation of short internodes with disproportionately thin sheaths. The abnormalities show a very definite selectivity for nerve roots and proximal nerves. Conversely, the frequency of degeneration and regeneration is greater distally except in the cervical ventral roots which contain numerous regenerating clusters. In the CNS numerous axonal spheroids are found in the lateral and ventral columns of the spinal cord and in various brain stem nuclei, particularly the superior olives, accessory cuneate nuclei and lateral lemniscus and its nucleus. Axonal degeneration which occurs mainly in the cord shows no obvious tract or proximal/distal selectivity. The optic pathways are also involved, predominantly adjacent to the chiasma. The autonomic nervous system is affected and distal limb muscles show varying, but usually minor, degrees of neurogenic atrophy. The condition, which has no obvious direct parallel in human or veterinary medicine, shows gross disturbances of axon-glial inter-relationships in both CNS and PNS.

Animals↗

PubMed1985

Aland eye disease: no albino misrouting.

Electrophysiological studies showed that a patient with Aland eye disease had no misrouting of the optic pathways which is always found in all forms of albinism as a consequence of the retino-geniculate anomaly. Also the spontaneous and optokinetic nystagmus did not resemble that of the large majority of human albinos. The marked asymmetry found in this patient seems to be typical for humans with a defective development of foveal binocular vision. These findings are in agreement with clinical, nystagmographic and EM findings that Aland eye disease is distinct from the Nettleship-Falls type of X-linked ocular albinism. Furthermore, Aland eye disease is different from X-chromosomal congenital stationary night blindness with myopia by the fact that the scotopic functions are only moderately affected and there is no restriction of the peripheral photopic visual fields. In addition, there is latent nystagmus of extraocular type that appears also in female carriers. There is no ophthalmoplegia, there is a progression of the myopia and the dyschromatopsia is of secondary type.

Adult↗

PubMed1993

The development of retinal ganglion cell decussation patterns in postnatal pigmented and albino ferrets.

The decussation patterns of retinal ganglion cells in postnatal pigmented and albino ferrets were examined by using retrograde axonal tracers. Following unilateral injections into the optic pathway of newborn pigmented ferrets, approximately 13,000 cells were labelled in the ipsilateral retina. The majority (11,500) of these were located in temporal retina. Postnatally, the numbers of cells projecting ipsilaterally from temporal retina fell by 49%. High rates of loss were observed in both the smaller uncrossed projection from nasal retina (92%) and also in the crossed projection from temporal retina (84%). After injections on the day of birth, a decussation line was not obvious in the crossed projection: > or = 14,000 labelled cells were found in temporal retina. Double tracer studies showed that very few of these cells had axons which projected bilaterally. The numbers of ipsilaterally projecting cells labelled in neonatal albino ferrets was dramatically reduced. Only approximately 2500 were labelled in temporal retina following injections at birth. As in pigmented ferrets, about half of these cells subsequently died. The reduced uncrossed projection in albino neonates was associated with an increase in the crossed projection from temporal retina, in which approximately 21,000 cells were labelled following injections at birth. These results suggest that differential postnatal ganglion cell death establishes the adult decussation pattern in the contralateral retinal projection but merely refines the pattern already established in the uncrossed projection. Postnatal ganglion cell death plays no significant role in generating the abnormal projections found in albino ferrets.

Albinism↗

PubMed1981

Impairment of protein synthesis in the retinal tissue in diabetic rabbits: secondary reduction of fast axonal transport.

Protein biosynthesis in the retina and fast axonal transport along the optic pathway were studied in rabbits in which diabetes had been experimentally induced. Retinal protein biosynthesis and axonal transport were significantly reduced in the diabetic rabbits, and the reduction was correlated to the severity of the diabetes. The "somal delay time' was only slightly elongated and the O/R ratio was fairly constant in the various levels of blood glucose; thus intrasomal protein movement seems to be less affected in diabetic rabbits. Velocity and the distribution pattern of axonally transported protein remained unaffected in the diabetic rabbits. These findings suggest that a disturbance in the metabolism in the cell body is the most important factor related to quantitative reduction of fast axonal transport in diabetic rabbits.

Animals↗

PubMed1996

Current trends in newly registered blindness in Denmark.

Current pattern of blindness (i.e. visual acuity < or = 6/60) in Denmark was studied based on 1585 application forms for new membership to the Danish Society of the Blind during 1993. Statistics on blindness are very sensitive to the definitions used. A change of blindness definition to visual acuity < 6/60 reduced the number of formally blind subjects with 32%, and by using the definition of WHO (visual acuity < 3/60) only 562 subjects (35%) would have been considered blind. The prevailing causes of blindness were age-related macular degeneration with 1132 cases (71.4%), followed by diabetic retinopathy 133 cases (8.4%), and glaucoma 80 cases (5.0%). Among the younger subjects (133 persons) aged 20-59 years diabetic retinopathy comprised 36% and lesions of the optic pathways 26%, while myopia and retinitis pigmentosa accounted for 5% each. The majority of the applicants (92%) were > or = 60 years old. In this group, age-related macular degeneration was the main cause of blindness in 78%. Figures from 1993 were compared with six similar studies on newly registered blindness from the last 35 years. The annual number of registrations was doubled during the last 25 years. The annual number of registered blind due to diabetic retinopathy fell during the 60's and 70's followed by a constant rate during the last decades. Glaucoma blindness fell with a factor two, and declined from a relative frequency of 15% among the causes of blindness to 5%. The impact of age related macular degeneration increased from 20% to 70% during the same period.

Adult↗

PubMed1987

Visual impairment in Danish children 1985.

In 1985 150 children aged 0-18 were reported to the Danish National Register for Visually Impaired Children. Cross tabulation of the ophthalmological diagnoses by site and type of affection was performed with respect to year of birth, aetiology, visual acuity and birth weight. Finally the relations between aetiology and the presence of additional handicaps are demonstrated. The 'incidence of notification' (IN) was calculated for each birth year as the number of notified children per 100,000 within each birth year group showing variations between 46 in the 1984 birth year group and 3 in the 1970 birth year group with a mean value of 14. The figures stress the impact of congenital and neonatal visual impairment. The significance of IN is discussed with respect to other concepts of incidence. It is concluded that the presented epidemiological method is useful as a tool of analysis in the planning of preventional strategies. From the tables the following main features may be highlighted: Nearly 90% of the blinding causes anatomically are located in the posterior segment of the eye, the optic pathways or in the brain. Isolated visual handicap was notified in 34% of the children, while another 48% presented central nervous system involvement. From an aetiological point of view it is noteworthy that no specific aetiology could be encircled in 38% of the material. In conclusion, it is proposed that future lines of ophthalmological work in the prevention of visual handicap in childhood should concentrate on a higher degree of specificity in diagnostic procedures and an intensified search for specific aetiologies in every single child with visual impairment.

Adolescent↗

PubMed1984

Form, function and intracortical projections of spiny neurones in the striate visual cortex of the cat.

We have studied the neuronal circuitry and structure-function relationships of single neurones in the striate visual cortex of the cat using a combination of electrophysiological and anatomical techniques. Glass micropipettes filled with horseradish peroxidase were used to record extracellularly from single neurones. After studying the receptive field properties, the afferent inputs of the neurones were studied by determining their latency of response to electrical stimulation at different positions along the optic pathway. Some cells were thus classified as receiving a mono- or polysynaptic input from afferents of the lateral geniculate nucleus (l.g.n.), via X- or Y-like retinal ganglion cells. Two striking correlations were found between dendritic morphology and receptive field type. All spiny stellate cells, and all star pyramidal cells in layer 4A, had receptive fields with spatially separate on and off subfields (S-type receptive fields). All the identified afferent input to these, the major cell types in layer 4, was monosynaptic from X- or Y-like afferents. Neurones receiving monosynaptic X- or Y-like input were not strictly segregated in layer 4 and the lower portion of layer 3. Nevertheless the X- and Y-like l.g.n. fibres did not converge on any of the single neurones so far studied. Monosynaptic input from the l.g.n. afferents was not restricted to cells lying within layers 4 and 6, the main termination zones of the l.g.n. afferents, but was also received by cells lying in layers 3 and 5. The projection pattern of cells receiving monosynaptic input differed widely, depending on the laminar location of the cell soma. This suggests the presence of a number of divergent paths within the striate cortex. Cells receiving indirect input from the l.g.n. afferents were located mainly within layers 2, 3 and 5. Most pyramidal cells in layer 3 had axons projecting out of the striate cortex, while many axons of the layer 5 pyramids did not. The layer 5 cells showed the most morphological variation of any layer, were the most difficult to activate by electrical stimulation, and contained some cells which responded with the longest latencies of any cells in the striate cortex. This suggests that they were several synapses distant from the l.g.n. input. The majority of cells in layers 2, 3, 4 and 6 had the same basic S-type receptive field structure. Only layer 5 contained a majority of cells with spatially overlapping on and off subfields (C- and B-type receptive fields).(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗

PubMedDate not supplied

Synergy effects between organic and inorganic UV filters in sunscreens.

The influence of the synergy effects between organic and inorganic UV filter substances on the sun protection factor (SPF) of topically applied sunscreen formulations is investigated. The medium is considered to have reflection, absorption, and scattering properties. The distribution of photons in this medium is investigated by Monte Carlo calculation. Typical optical parameters of the skin and substances are used to characterize the synergy effect. The results of the model calculation are checked by in vitro and in vivo measurements investigating the influence of different types of scattering microparticles on the absorption efficacy of topically applied formulations. It is found that the inorganic filter substances act as scattering microparticles in the upper skin layers. They increase the optical pathway of the photons in the topically applied absorbing formulation also localized there. In this way, more photons are absorbed, increasing the SPF. The results obtained are important for the optimization of the SPF of sunscreen formulation containing organic and inorganic UV-filter components.

Administration, Cutaneous↗

PubMed2001

astray, a zebrafish roundabout homolog required for retinal axon guidance.

As growing retinotectal axons navigate from the eye to the tectum, they sense guidance molecules distributed along the optic pathway. Mutations in the zebrafish astray gene severely disrupt retinal axon guidance, causing anterior-posterior pathfinding defects, excessive midline crossing, and defasciculation of the retinal projection. Eye transplantation experiments show that astray function is required in the eye. We identify astray as zebrafish robo2, a member of the Roundabout family of axon guidance receptors. Retinal ganglion cells express robo2 as they extend axons. Thus, robo2 is required for multiple axon guidance decisions during establishment of the vertebrate visual projection.

Alleles↗

PubMed2002

Familial neurofibromatosis microdeletion syndrome complicated by rhabdomyosarcoma.

Neurofibromatosis type 1 with dysmorphism and developmental delay is reported in a mother and two children. The son required treatment for a prostatic rhabdomyosarcoma. His sister has an optic pathway glioma. Fluorescence in situ hybridisation confirmed a submicroscopic deletion at 17q11.2. New evidence suggests an increased malignancy frequency in microdeletion cases.

Adult↗