Search PubMed⌕ Search

Biomedical subjects

M G Hadfield

Publications and source records attributed to M G Hadfield.

67 records · Page 4Linked to original sources

Cocaine. Selective regional effects on central monoamines.

Cocaine HCl (0, 10, or 50 mg/kg) was injected into adult male ICR mice ip. Thirty minutes later, the brains were removed, and nine regions were isolated: olfactory bulbs, olfactory tubercles, prefrontal cortex, septum, striatum, amygdala, hypothalamus, hippocampus, and thalamus. Using high-performance liquid chromatography, concentrations of norepinephrine, dopamine, serotonin, and their major metabolites and the metabolite/neurotransmitter ratios were determined as an indicator of utilization. Serotonergic systems responded most dramatically. 5HIAA/5-HT decreases were seen in all the brain regions, except the septum, hippocampus, and olfactory bulbs. In most instances, the alterations were dose-dependent. The most profound changes were seen in the amygdala, prefrontal cortex, hypothalamus, and thalamus. For noradrenergic systems, significant responses were seen only in the amygdala, prefrontal cortex, and hypothalamus, but then only at the lower dose. The dopaminergic responses were more complex and not always dose-dependent. The DOPAC/DA ratio was decreased only in the amygdala and striatum at the lower dose, and the olfactory tubercles at the higher dose. It was increased in the septum. The HVA/DA ratios were decreased in the amygdala, prefrontal cortex, and hypothalamus, but only at the lower dose (like MHPG/NE). The 3MT/DA ratio was decreased in the thalamus at the lower dose and in the olfactory tubercles at the higher dose, whereas it was increased in the prefrontal cortex at the lower dose. The HVA and DOPAC routes of degradation were both utilized only by the amygdala. Thus, cocaine produced its most comprehensive effects in this nucleus, as well as the greatest absolute percentage changes for all three of the monoamine systems studied.

3,4-Dihydroxyphenylacetic Acid↗

Ewing's family of tumors involving structures related to the central nervous system: a review.

This review consolidates information gleaned from several case reports and larger series on Ewing's sarcoma family of tumors (EFT) involving structures related to and found in the central nervous system (CNS). These tumors involve the skull, the spinal column, adjacent soft tissues, the meninges, and the brain. We have separated the cases by skull region and spinal column level, and we discuss the attendant differences in prognosis following treatment by neurosurgery, radiation, and chemotherapy. Light and electron microscopic features can be used to differentiate EFT from other small round blue cell tumors that involve the CNS (central primitive neuroectodermal tumor, lymphoma, etc.). Recent molecular and genetic findings in EFT provide new diagnostic methods. We conclude that EFT involving the CNS and adjacent structures is not so rare as previously stated and that the prognosis is more favorable, as a rule, than for the more common examples arising in the long bones and pelvis.

Adolescent↗

Herpesvirus type 1 serum antibodies and brain tumors in humans.

Sixty-five patients underwent craniotomy for brain tumors; of these 35 had glioblastoma multiforme (GM). The GM cases, as a group, showed significantly higher serum titers for herpesvirus type 1 (HSV-1) neutralizing antibodies (NT) than the non-glioblastoma cases. Both the GM group and the pituitary adenoma group had high levels of HSV-1 serum antibodies with the enzyme-linked immunosorbent assay (ELISA). These data, combined with other evidence, lead us to speculate that HSV-1 infections may be associated with certain brain tumors in humans. However, coincidental causes for these elevated HSV-1 titers must be ruled out.

Adenoma↗

Neuro-Behçet's disease.

We are reporting a case of Behçet's disease without vasculitis, but with acute neutrophilic inflammation which involved the brain and other organs. The patient exhibited waxing and waning neurological deficits which were unresponsive to treatment. The neuroradiologic findings simulated those of multiple sclerosis. The neuropathological examination revealed an acute, focal, though disseminated encephalitis involving the frontal lobe, internal capsule, basal ganglia, cerebellum, and brain stem. The acute inflammation consisted of a neutrophilic and eosinophilic infiltration of the perivascular spaces and parenchyma without evidence of vasculitis, fibrinoid necrosis, or thrombosis. Cultures and special stains for microbial organisms were negative. Ultrastructural examination revealed no viral structures or other microorganisms. In situ hybridization for Epstein-Barr virus (EBV), herpes simplex virus type I (HSVI), and cytomegalovirus (CMV) was negative. In this case, the lack of inflammation in the vessel walls points out that the necrotizing lesions in neuro-Behçet's disease need not be the result of vasculitis and superimposed thrombosis, but may occur as a result of primary, acute neutrophilic inflammation.

Adult↗

Extrapontine myelinolysis of the basal ganglia without central pontine myelinolysis.

Since the first descriptions of central pontine myelinolysis (CPM) were put forth it has become evident that myelinolysis may not be exclusively restricted to the pons. In many cases myelinolysis may share other brain regions, while in still others the pons may not be affected at all, as in the present case of pure basal ganglia myelinolysis. Regardless of geographic location, too rapid correction of hyponatremia has been invoked as the triggering mechanism which leads to both CPM and extrapontine myelinolysis (EPM). This case of EPM is that of a 61-year-old male who suffered spinal cord compression and quadriplegia due to the breakdown of a double cervical fusion at C4-5/C5-6 for herniated discs. One month later, following vomiting and poor food intake, a low serum Na+ of 101 mmol/l developed and was corrected to 128 mmol/l in 37 h (and from 104 mmol/l to 121 mmol/l in 15 h). Altered mental status ensued and a T2 weighted MRI showed symmetrical, bilateral high intensity foci in the basal ganglia 3 weeks before death. Histologically there were bilateral, circumscribed, spheroidal areas of demyelination involving the striatal fibers which course through the putamina. The pons was spared. This case illustrates that extrapontine, basal ganglia myelinolysis may occur in the absence of CPM or alternate areas of myelinolysis. We discuss other cases of EPM, with and without CPM, to define the brain regions involved. MRI is uncovering many new cases of EPM and CPM. This permits one to follow the evolution of the myelinolytic lesions and to correlate their progression or regression with treatment modalities and the neurological findings.

Basal Ganglia Diseases↗

Neuro-Behçet's disease.

We are reporting a case of Bechçet's disease without vasculitis but with acute neutrophilic inflammation which involved the brain and other organs. The patient exhibited waxing and waning neurological deficits which were unresponsive to treatment. The neuroradiologic findings simulated those of multiple sclerosis. The neuropathological examination revealed an acute, focal, though disseminated encephalitis involving the frontal lobe, internal capsule, basal ganglia, cerebellum, and brainstem. The acute inflammation consisted of a neutrophilic and eosinophilic infiltration of the perivascular spaces and parenchyma without evidence of vasculitis, fibrinoid necrosis, or thrombosis. Cultures and special stains for microbial organisms were negative. Ultrastructural examination revealed no viral structures or other microorganisms. In situ hybridization for Epstein-Barr virus (EBV), herpes simplex virus type I (HSV-I), and cytomegalovirus (CMV) was negative. In this case, the lack of inflammation in the vessel walls points out that the necrotizing lesions in neuro-Bechçet's disease need not be the result of vasculitis and superimposed thrombosis, but may occur as a result of primary, acute neutrophilic inflammation.

Acute Disease↗