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Biomedical subjects

E Alexander

Publications and source records attributed to E Alexander.

At least 163 records · Page 9Linked to original sources
PubMed1990

Presumed choroidal metastasis of Merkel cell carcinoma.

Merkel cell carcinoma is a rare skin tumor of neural crest origin and is part of the amine precursor uptake and decarboxylase system. It typically occurs on the face of elderly people. Distant metastasis is almost uniformly fatal. Choroidal metastasis, to our knowledge, has not been described. We report a patient with Merkel cell carcinoma who had a synchronous solid choroidal tumor and a biopsy-proven brain metastasis. Our 56-year-old patient presented with a rapidly growing, violaceous preauricular skin tumor. Computed tomography of the head disclosed incidental brain and choroidal tumors. Light and electron microscopy of biopsy specimens of both the skin and the brain lesions showed Merkel cell carcinoma. Ophthalmoscopy, fluorescein angiography, and A and B echography revealed a solid choroidal mass. The brain and skin tumors responded well to irradiation. A radioactive episcleral plaque was applied subsequently to the choroidal tumor. All tumors regressed, and the patient was doing well 28 months later. To our knowledge this is the first case of presumed choroidal metastasis of Merkel cell carcinoma.

Biopsy↗
PubMed1989

The MRL +/+ mouse: a new model of tubular aggregates which are gender- and age-related.

Congenic mice of the MRL +/+ substrain provide an animal model for study of tubular aggregates in skeletal muscle. Tubular aggregates appear limited only to males of the MRL +/+ strain and are not found in other strains, including MRL +/-, MRL lpr/lpr, BXSB/MpJ, BALB/c, SJL/J, AJ, or C3H HEJ. This strain-specific occurrence, and the gradually increasing abundance of tubular aggregates after 6 months of age until virtually all type II myofibers are affected by 2 years, implies that both genetic and developmental factors are necessary for the occurrence of tubular aggregates. These two factors are not sufficient, however, since hormonal alteration by male castration nearly completely prevents the expression of tubular aggregates. Parallels are drawn with how expression of tubular aggregates is limited largely to males in diverse acquired and hereditary human neuromuscular disorders.

Animals↗
PubMed1989

The acute onset of nausea and vomiting following stereotactic radiosurgery: correlation with total dose to area postrema.

From 1986 to 1988, 44 patients have been treated for tumors or vascular lesions with stereotactic radiosurgery using a modified standard linear accelerator. In seven patients, nausea and vomiting occurred within 6 hours after the completion of radiosurgery. One of these patients with nausea and occasional vomiting pretreatment had exacerbation several hours after treatment, in spite of droperidol and prochlorperazine prophylaxis. Nausea and vomiting in the other six patients was self-limited and was completely resolved by 12 hours from onset. None of these six patients suffered from nausea and vomiting before treatment. This was directly correlated with the total dose to the vomiting center in the floor of the fourth ventricle (area postrema). The median dose to the vomiting center in the seven patients was 618 cGy (range 275-1257). The final patient in the series received 1088 cGy to the area postrema after droperidol and dexamethasone prophylaxis without developing nausea or vomiting. In the remaining 36 patients who received from less than 5 to 184 cGy to area postrema, nausea and vomiting did not occur. We recommend that patients treated with large fractions of radiation by radiosurgery in this area be premedicated appropriately.

Brain Neoplasms↗
PubMed1989

Euthanasia.

Explore the source record for details and available documents.

Attitude of Health Personnel↗
PubMed1989

Merkel cell carcinoma. Long term survival in a patient with proven brain metastasis and presumed choroid metastasis.

Merkel cell carcinoma (Trabecular carcinoma) is a rare malignant tumor of the skin. Because these tumors tend to spread locally via the lymphatic system, very few papers have dealt with the treatment of distant metastasis. Systemic disease is uncommon and usually fatal. In this paper, we report a case of Merkel cell carcinoma with proven brain metastasis and a solid choroidal tumor. The patient responded well to radiation and chemotherapy and is alive and neurologically intact three years after diagnosis. All previous patients with metastatic Merkel cell carcinoma to the brain died within two months of the diagnosis. We use this case to discuss possible routes of metastatic dissemination and to review the treatment options in patients with distant metastatic disease. To our knowledge, this is the first reported case of presumed choroidal metastasis of Merkel cell carcinoma and the longest documented survival in a patient with brain involvement.

Brain Neoplasms↗
PubMed1989

Stereotactic radiosurgery for intracranial arteriovenous malformations using a standard linear accelerator.

We have previously described the development of a technique which utilizes a standard linear accelerator to provide stereotactic, limited field radiation. The radiation is delivered using a modified and carefully calibrated 6 MV linear accelerator. Precise target localization and patient immobilization is achieved using a Brown-Roberts-Wells (BRW) stereotactic head frame which is in place during angiography, CT scanning, and treatment. Seventeen arteriovenous malformations (AVMs) have been treated in 16 patients from February 1986 to July 1988. Single doses of 1500-2500 cGy were delivered using multiple non-coplanar arcs with small, sharp edged x-ray beams to lesions less than 2.7 cm in greatest diameter. The dose distribution from this technique has a very rapid dropoff of dose beyond the target volume. Doses were prescribed at the periphery of the AVMs, typically to the 80-90% isodose line. Eleven of 16 patients have been followed by repeat angiography at least 1 year following treatment. Five of 11 have had complete obliteration of their AVM in 1 year and an additional three patients have achieved complete obliteration by 24 months. There have been no incidences of rebleeding or serious complications in any patient. We conclude that stereotactic radiosurgery using a standard linear accelerator is an effective and safe technique in the treatment of intracranial AVMs and the results compare favorably to the more expensive and elaborate systems that are currently available for stereotactic treatments.

Adolescent↗
PubMed1989

Histiocytosis X of the hypothalamus.

An 18-year-old woman presented with visual disturbance and endocrine dysfunction (diabetes insipidus, delayed puberty, hypothyroidism, hypoadrenalism, and hyperprolactinemia). Computed tomography and enhanced cisternography showed a single hypothalamic mass, which proved at biopsy to be histiocytosis X. Further studies showed the disease to be restricted to the hypothalamus. The patient was treated with hormonal replacement therapy, but her visual acuity continued to worsen. Visual acuity improved after low-dose irradiation of the pituitary fossa and hypothalamus, which also led to disappearance of the mass. This case shows that localized hypothalamic histiocytosis X can be diagnosed and treated successfully before other systems become involved.

Adolescent↗
PubMed1989

Kluver-Bucy syndrome following recovery from transtentorial herniation.

Kluver-Bucy syndrome is an uncommon constellation of behavioral abnormalities resulting from bilateral temporal lobe damage. The syndrome is rare in humans. In this paper we present a patient who developed the Kluver-Bucy syndrome following recovery from an intracerebral haemorrhage and transtentorial herniation.

Adult↗