Biomedical subjects
B Horten
Publications and source records attributed to B Horten.
Urothelial injury from ethylenediaminetetraacetic acid used as an irrigant in the urinary tract.
Although solutions containing disodium ethylenediaminetetraacetic acid (EDTA) will dissolve calcium oxalate stones in vitro, the safety of such solutions as urinary tract irrigants is questionable. These studies were designed to assess the degree of urothelial damage produced by the mildest EDTA formulation which has been reported to be effective. Rabbit bladders were irrigated antegrade via a ureterotomy for 20 hours and then removed for histological examination. A 0.03 M solution of disodium EDTA at pH 7.5 produced considerably more urothelial injury than did an otherwise identical solution of calcium EDTA (p = 0.006). The bladders from the latter group were undistinguishable from those irrigated with saline. As prior saturation of EDTA with calcium completely eliminated the tissue injury, these studies indicate that the same calcium chelating property which makes this chemical effective also makes it toxic. There was enough tissue damage from the relatively mild formulation used to suggest no EDTA solution yet formulated is safe for clinical use.
Rheumatoid nodule of the temporal bone.
A 69-year-old woman with severe rheumatoid arthritis presented with a history of chronic otitis and a facial nerve paralysis. She was found to have a rheumatoid nodule involving the mastoid and mesotympanum. This is believed to be the first reported case of a rheumatoid nodule involving the temporal bone.
Progressive multifocal leukoencephalopathy: a burnt-out case.
A patient with Hodgkin's disease developed progressive multifocal leukoencephalopathy (PML), documented by brain biopsy to be associated with JC virus infection. His disease progressed over several months, resulting in severe neurological deficit, but then stabilized with little or no further clinical progression during the remaining year of his life. Histopathological evaluation of the brain at autopsy supported the clinical impression that brain infection was arrested. Whereas the brain biopsy exhibited the histological features of active PML including giant bizarre astrocytes, at postmortem examination brain lesions appeared inactive, with regression of astrocytic changes and elimination of oligodendroglial inclusions. Similarly, JC virus antigen, present in the brain biopsy, was not detected in the autopsied brain. This case provides further evidence that PML is not invariably fatal and that clinical and cytological remission can occur.
Neuroblastoma, tuberous sclerosis, and subependymal giant cell astrocytoma.
A patient with Stage III paratesticular neuroblastoma diagnosed in infancy was treated with radiotherapy and chemotherapy. Typical depigmented "ash leaf" skin lesions of tuberous sclerosis appeared during early childhood. At 7 years of age he underwent craniotomy for a subependymal giant cell astrocytoma. The occurrence of neuroblastoma, tuberous sclerosis, and astrocytoma is unique, and supports the suggested relationship between neural crest tumors and hamartoma syndromes.
Supratentorial recurrences in medulloblastoma.
Four children with medulloblastoma had massive supratentorial recurrences in the region of the cribriform plate after adequate craniospinal irradiation. The pathogenesis of these recurrences is probably related to underdosage to this region by shielding of the eyes. This hypothesis was corroborated by autopsy findings in two other patients in whom subfrontal implants were histologically different from recurrences elsewhere. Two possible solutions to avoid this problem in the future are suggested.
Multifocal varicella-zoster virus leukoencephalitis temporally remote from herpes zoster.
Two patients with cancer, one with Hodgkin's disease and the other with a granulosa cell tumor of the ovary, developed a progressive, eventually fatal infection of the central nervous system exhibiting multifocal symptoms and signs. Pathologically, gross abnormalities of the brain resembled those in progressive multifocal leukoencephalopathy (PML), with discrete and confluent plaque-like lesions concentrated in the white matter, particularly along the gray-white junction. Microscopically, pathological changes differed distinctly from those associated with PML; in addition to confluent foci of white matter injury characterized by early demyelination and subsequent necrosis, prominent Cowdry type A eosinophilic intranuclear inclusions were noted in oligodendrocytes, astrocytes, and neurons. By electron microscopy, intranuclear spherical particles consistent in size and appearance with herpesvirus nucleocapsids were found within the lesions. Immunoperoxidase studies detected varicella-zoster virus (VZV) antigens in infected cells, implicating this virus as the responsible agent despite a lapse of many months between the cutaneous herpes zoster and onset of cerebral symptoms in both patients.
Progressive white matter destruction following irradiation of an extracranial neoplasm.
Although numerous "cures# have been reported following surgical extirpation of symptomatic foci of cerebral radiation nerosis, delayed progressive white matter destruction and neurological deterioration may occur in some patients who survive for prolonged periods after operation. The postoperative appearance on CT scans of hypodensity within heavily irradiated white matter structures at a distance from the initial radionecrotic focus or operative site suggests continuing radiation-induced tissue injury and a poor prognosis. Anticipated survival as well as administered radiation dose must be taken into account when "safe# radiation thresholds are calculated.
Leukoencephalopathy following high-dose iv methotrexate chemotherapy with leucovorin rescue.
Seven patients with bone or soft tissue sarcomas but without metastatic CNS disease developed a chronic leukoencephalopathy after high-dose (8000-15,000 mg/m2) iv methotrexate (MTX) chemotherapy with leucovorin (LV) rescue. Approximately 12 MTX-LV treatments were administered over a 3-7 month period. None of the patients had cranial irradiation. The syndrome usually began several months after the initiation of chemotherapy with subtle personality changes followed by a progressive dementia, focal seizures, pseudobulbar palsy, spastic quadriparesis, and stupor. Computerized tomographic scans revealed diffuse white matter hypodensity in five patients and atropic changes in five patients. Serum MTX concentrations were elevated in four of six patients prior to several MTX-LV treatments, suggesting that MTX persisted in tissues for a long time. Abnormally high levels of MTX were detected in the cerebrospinal fluid of all four patients several days after an MTX-LV treatment, at a time when their encephalopathy was most severe. Pathologic brain material was obtained from three patients and revealed a spectrum of abnormalities. The syndrome observed in our patients clinically resembles the one described in children with acute lymphatic leukemia who received cranial irradiation and large cumulative amounts of low-dose (12-20 mg/m2) systemic MTX without LV.
Primary neuroblastoma of the cauda equina.
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Meningeal gliomatosis: a review of twelve cases.
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Neuroblastoma metastatic to the leptomeninges.
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