K.M.A. Welch
Henry Ford Hospital
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Featured researches published by K.M.A. Welch.
Journal of Cerebral Blood Flow and Metabolism | 1989
Michael Chopp; Robert A. Knight; Carl D. Tidwell; Joseph A. Helpern; Eileen Brown; K.M.A. Welch
The metabolic effects of graded whole body hypothermia on complete global cerebral ischemia and recirculation was investigated in the cat. Hypothermia was induced to one of three levels prior to ischemia; T = 26.8° ± 0.5° (n = 4), T = 32.1° ± 0.2°C (n = 5), and T = 34.6° ± 0.3°C (n = 6), and maintained constant throughout 16 min of ischemia and 1.5–2 h of recirculation. Intracellular cerebral pH and relative concentrations of high-energy phosphate metabolites were continuously monitored, using in vivo 31P nuclear magnetic resonance (NMR) spectroscopy. Except for the first 4 min of ischemia, no significant differences were detected in the response of adenylate intensities and intracellular pH to ischemia and recirculation between the hypothermic groups. The three hypothermic groups were then pooled into one group, and the data compared to previously published data from a normothermic group, T = 38.4° ± 0.6°C (n = 14), and a hyperthermic group, T = 40.6° ± 0.2°C (n = 9), subjected to the identical ischemic and NMR measurement protocols. The hypothermic animals exhibited a statistically significant reduction of cerebral intracellular acidosis, both during ischemia and recirculation, as well as a more rapid return of adenylate intensities during recirculation, compared to the normothermic or hyperthermic groups. The data thus suggest that mild hypothermia has an ameliorative affect on brain energy metabolism and intracellular pH under conditions of complete global cerebral ischemia and recirculation.
Ophthalmology | 1988
Steven R. Levine; John W. Crofts; G. Robert Lesser; John Floberg; K.M.A. Welch
The lupus anticoagulant is an acquired serum immunoglobulin that prolongs several coagulation parameters, most notably the partial thromboplastin time (PTT). Most commonly, this condition is found in association with systemic lupus erythematosus (SLE) but may be seen with other collagen-vascular diseases and in otherwise healthy individuals. Despite the laboratory tests suggesting impaired coagulation, clinically the lupus anticoagulant has been associated with thrombosis. The authors present five patients with the lupus anticoagulant who came to medical attention because of branch retinal artery occlusion, ischemic optic neuropathy, transient visual loss, transient diplopia, or vertebrobasilar insufficiency. Eleven previously reported patients with the lupus anticoagulant and disturbed vision are also reviewed with additional findings of retinal venous occlusive disease and homonymous visual field loss. The relationship of these findings to retinopathy in SLE is discussed. Patients with the lupus anticoagulant (with or without SLE) may develop disturbances in vision due to thrombosis from a hypercoagulable state. We recommended obtaining a PTT, VDRL, and the more sensitive anticardiolipin antibody in patients with unexplained visual symptoms.
Cephalalgia | 1984
K.M.A. Welch; Deborah Darnley; Robert Simkins
The epidemiological, clinical and basic science evidence for a role of estrogen in migraine is reviewed. The hypothesis is put forward that estrogen exerts its influence by modulating sympathetic control of the cerebral vasculature.
Cephalalgia | 1991
Giovanni D'Andrea; A.R. Cananzi; Rajiv Joseph; M Morra; F Zamberlan; F Ferro Milone; S. Grunfeld; K.M.A. Welch
Platelet levels of glutamic and aspartic acid and glycine were measured in patients with migraine with aura, migraine without aura, tension headache and cluster headache. High levels of these amino acids were found in patients with migraine with aura compared to normal subjects and other headache groups. During headache, glutamate levels further increased in migraine with aura patients. These findings may have relevance to the neurological symptoms of migraine with aura.
Cephalalgia | 1995
A.R. Cananzi; Giovanni D'Andrea; Francesco Perini; F. Zamberlan; K.M.A. Welch
We evaluated plasma and platelet glutamate and glutamine levels in migraine with and without aura during headache-free periods and compared the results with those of normal controls. The plasma and platelet levels of glutamine in migraine with and without aura were normal. Migraine without aura patients had higher glutamate levels in plasma, and normal platelet levels. In migraine with aura patients, glutamate levels were high in platelets, but not in plasma. This suggests different profiles of excitatory amino acid metabolism in migraine with and without aura.
Cephalalgia | 1990
Sandra Nagel-Leiby; K.M.A. Welch; Giovanni D'Andrea; S. Grunfeld; Eileen Brown
Plasma norepinephrine and dopamine and event-related slow potentials were measured at menses and ovulation in migraine with and without aura relative to normal subjects. The results indicated that at menses, but not ovulation, plasma dopamine was increased and norepinephrine was decreased relative to normal. This catecholamine imbalance was greater in migraine without aura than in migraine with aura. Conversely, event-related slow potentials measured over the posterior cortex at ovulation but not at the menses was altered relative to normal. Early epoch negativity was reduced in migraine with aura, whereas late epoch negativity was reduced in migraine without aura. The results suggested that (a) migraine without aura may involve dynamic shifts in the function of both norepinephrine and dopamine responsive neurons; (b) pathophysiology of migraine with aura is less dependent on catecholamine imbalance (norepinephrine alone affected); (c) these pathophysiological mechanisms are most prevalent in or restricted to posterior cortical regions but may be modulated by brainstem mechanisms.
Stroke | 1987
Michael Chopp; S Frinak; D R Walton; M B Smith; K.M.A. Welch
In vivo 31P nuclear magnetic resonance spectroscopy was used to monitor the time course of intracellular pH in cat cerebral cortex subjected to global cerebral ischemia under control and hyperglycemic pretreatment conditions. Transient (16 minutes) global cerebral ischemia was induced in 14 cats using an inflatable cervical cuff combined with systemic arterial hypotension. Six cats were pretreated with infusion of 1.5 g/kg glucose prior to ischemia. Relative concentrations of high-energy phosphate metabolites and intracellular pH were continuously monitored before, during, and for 2 hours after cerebral reperfusion. During ischemia, intracellular pH fell to the same level and followed a similar time course in both groups. However, during initial reperfusion in the hyperglycemic group, there was a severe further decline (p less than 0.003) in intracellular pH. We suggest that the increased neurologic deficit and mortality found in hyperglycemic animals subjected to cerebral ischemia may be attributed to this transient severe tissue acidosis.
Cephalalgia | 1987
Steven R. Levine; Rajiv Joseph; Giovanni D'Andrea; K.M.A. Welch
Lupus anticoagulants (LA) are antiphospholipid serum immunoglobulins generally associated with autoimmune conditions, especially systemic lupus erythematosus (SLE). They have recently been linked to thrombotic events, including stroke. A possible association of migraine with LA is now forwarded with the presentation of two cases and a literature review. Our two patients, both in their forties, had migrainous phenomena without SLE or thrombotic events. Eight other cases were found in the literature, suggesting more than a chance association. Relevance to migraine pathophysiology is discussed and may come from the ability of the LA to alter prostaglandins and platelet activity and to interact with neuronal phospholipids. Further, larger studies are needed to support this association.
Magnetic Resonance in Medicine | 1999
Peter B. Barker; Edward J. Butterworth; Michael D. Boska; Jay Nelson; K.M.A. Welch
Multislice, two‐dimensional phosphorus 31 spectroscopic imaging (SI) of human brain was performed in 15 normal volunteers on a 3‐Tesla magnetic resonance system. Images of free magnesium concentrations and pH as well as phosphoesters, inorganic phosphate, phosphocreatine, and adenosine triphosphate (ATP), were calculated from the SI data. By using the equations of Golding and Golding (Magn. Reson. Med. 1995;33:467–474), average [Mg2+] for all brain regions studied was 0.42 ± 0.05 mM, whereas average brain pH was found to be 7.07 ± 0.03, with no significant regional variations. Phosphorus metabolite concentrations (relative to ATP, assumed to be 3.0 mM/kg wet weight) were 5.39 ± 1.88, 1.30 ± 0.39, 5.97 ± 3.17, and 4.33 ± 1.45 mM/kg wet weight for phosphomonoesters, inorganic phosphate, phosphodiesters, and phosphocreatine (PCr), respectively. These values are in good general agreement with those reported previously. Typical signal‐to‐noise ratios of 15:1 were obtained for PCr in spectra from nominal 31.5 cc voxel sizes with a 34‐min scan time. Limits on spatial resolution and the likely error of the magnesium and pH values are discussed. Magn Reson Med 41:400–406, 1999.
Cephalalgia | 1990
Sandra Nagel-Leiby; K.M.A. Welch; S. Grunfeld; Giovanni D'Andrea
Radioimmunoassays were used to measure interictal levels of ovarian steroids (oestradiol, total oestrogens and progesterone) in migraine patients at the onset of menses and coincident with the luteinizing hormone surge preceding ovulation. Results of these verified bio-chemically-contrasting points of the ovarian cycle were used to compare 13 migraine patients without aura and 6 migraine patients with aura with 17 non-migraine women. No group differences were found for physiological basal levels of ovarian steroids measured at menses. Preceding ovulation elevation in oestradiol levels relative to normal was found in migraine patients with aura but not in migraine patients without aura. These results suggest that a variation in oestradiol levels is an important factor in the different clinical expressions of migraine.