Biomedical subjects
Publications and source records attributed to J R Rich.
The synthesis of a versatile L-rhamnose monosaccharide synthon is described. This synthon is used in the synthesis of a disaccharide containing the rare sugar, 6-deoxy-L-glucose, linked to the 3-C-hydroxymethyl group of methyl 2,3-O-isopropylidene 3-C-(hydroxymethyl)-beta-D-erythrofuranoside.
In this study we examined 37 subjects with a diagnosis of intractable frontal lobe epilepsy (FLE) based on non-invasive pre-surgical evaluation. Twenty-six underwent chronic intracranial ictal recordings (CIR) with video monitoring; 20 of these went on to surgical resection. Eleven underwent surgery without CIR. Retrospectively, we determined that 19 had pure FLE, 12 had frontal plus extrafrontal epileptogenic zones, and six others did not have FLE. We analysed the whole group and individual categories to evaluate the determinants of surgical outcome. Sixty percent of the pure frontal group is seizure free with all having > or = 75% reduction. The frontal-plus group had only 10% seizure free with 70% having > or = 75% reduction. Being in the pure frontal group was associated with better outcomes than the 'frontal-plus' group (P < 0.05; chi-square). Subjects with FSIQ > or = 85, focal pathologies and 18FDG-PET scans which were normal or had focal abnormalities (P < or = 0.05, all, chi-square) were more likely to have excellent outcomes. MRI abnormalities, surface EEG, and location and size of resection were not predictive of surgical outcomes. Rasmussen's encephalitis, incomplete surgical strategies and bilateral foci were apparent in those with poor outcomes, and surgical size predicted post-operative deficits (chi-square; P < 0.001). We conclude that careful, hypothesis-driven implants and operating procedures can result in good surgical outcomes for frontal lobe epilepsy subjects even when lesions are not apparent on routine neuroimaging.
BACKGROUND: The popularity of subdural electrodes for the presurgical evaluation of patients with intractable seizures is increasing. However, few reports have prospectively dealt with their efficacy and safety. METHODS: We conducted a 5-year prospective study of patients evaluated by the California Comprehensive Epilepsy Program, who subsequently underwent subdural electrode implantation at one of two institutions. Efficacy was examined by ultimate outcome with regards to postsurgery resection seizure frequency. Fifty-five patients underwent 58 implant procedures and postresection outcomes were available in 47 patients. Safety was defined by the incidence of expected and unexpected complications, and neuropathologic examination of tissue specimens. RESULTS: The most common expected adverse effects during implant were fever < or = 102 degrees (41%), cerebrospinal fluid leakage (19%), headache (15%), and nausea (4%). There were no infections. Unexpected adverse events included fever > 102 degrees F (5%), migraine (5%), iatrogenic electrode dysfunction (5%), and temporalis muscle fibrosis (5%). The incidence of pathologic findings suggestive of foreign body reaction was 10%. There were no permanent sequelae. Surgical outcomes were excellent in all (> or = 75% seizure reduction) with 50% seizure free regardless of the focus. CONCLUSIONS: Subdural electrodes are a safe, easy, and efficacious tool for evaluating seizure foci prior to resective surgery. They should no longer be considered investigational devices.
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Dynorphin A(1-17), an opioid peptide that is normally present in the hippocampal mossy fiber system, was localized immunocytochemically in the hippocampal formation of control autopsy and temporal lobe epilepsy (TLE) specimens. In control tissue, dynorphin-like immunoreactive (Dyn-IR) structures were confined to the mossy fiber path and were most highly concentrated in the polymorph (hilar) region of the dentate gyrus. Very few Dyn-IR structures were present in the molecular and granule cell layers of the dentate gyrus. In contrast, in all TLE specimens, Dyn-IR elements were present in these layers. The extent of aberrant staining varied among the TLE specimens, and 2 major patterns were observed. The first was a relatively wide band of reaction product in the inner one-third to one-fourth of the molecular layer (8 cases), and the second was a more limited distribution of immunoreactive fibers and presumptive terminals in the granule cell and immediately adjacent supragranular regions (2 cases). The extent of aberrant Dyn-IR structures appeared to be related to the amount of cell loss in the polymorph and CA3 fields and to dispersion of the granule cell somata. Specimens processed with the Timm's sulfide silver method for heavy metals provided independent evidence for the distribution of mossy fibers. In both control and TLE specimens, the patterns of labeling were virtually identical to those of dynorphin localization. These findings suggest that sprouting of mossy fibers or their axon collaterals has occurred in hippocampal epilepsy and that the reorganized fibers contain at least one of the neuropeptides that are normally present in this system. Such fibers could form recurrent excitatory circuits and contribute to synchronous firing and epileptiform activity, as suggested in studies of experimental models of epilepsy.
Sera from patients with various types of central nervous system tumors display antibodies reactive in serologic assays with cells and extracts derived from human brain neoplasms. Soluble antigens extracted and purified from surgical specimens of human meningiomas (MSA) were used to test for precipitating antibodies in sera from patients with various histologic types of brain tumors, non-neural solid tumors and from normal donors. Blind studies by immunodiffusion (ID) showed that 63% (15/24) of meningioma patients, 53% (9/17) of glioma patients and 17% (5/29) of patients with various other brain neoplasms had antibodies that reacted with two of three meningioma-associated antigens. Sera from normal donors and patients with non-neural solid neoplasms reacted to a limited extent (7/118) with another of these tumor-associated antigens. Cross-reaction and absorption studies revealed that the three meningioma-associated antigens were detecting different antibodies. None of the antigens was related to HLA antigens or to the human non-neurotropic viruses used in our assays.
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