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Biomedical subjects

J C Grotta

Publications and source records attributed to J C Grotta.

At least 109 records · Page 6Linked to original sources
PubMed1989

Prediction of carotid stenosis progression by lipid and hematologic measurements.

We followed 19 men and 19 women with asymptomatic carotid stenosis up to 30 months to determine whether hematologic or lipid abnormalities could identify those individuals developing progressing carotid atherosclerosis (defined as an increase in mean percent stenosis greater than or equal to 19% or an increase in a single region of greater than or equal to 23%) on B-mode carotid ultrasonography performed at 2- to 6-month intervals. Our patients demonstrated increased beta-thromboglobulin, platelet factor 4, and fibrinogen compared with age-matched controls. Eight patients developed progression of carotid stenosis, and this group had higher baseline low-density lipoprotein (LDL) and fibrinogen than the 30 nonprogressing patients. Multiple regression analyses of age, sex, smoking, coronary artery disease, peripheral vascular disease, diabetes, hypertension, and baseline high-density lipoprotein (HDL), HDL2, HDL3, LDL, beta-thromboglobulin, platelet factor 4, and fibrinogen identified coronary artery disease and elevated LDL and fibrinogen as the only independent variables significantly associated with the progressing group. We conclude that, in patients with carotid atherosclerosis, a combination of coronary artery disease and elevated LDL and fibrinogen will predict with 88% accuracy whether the patient will have progressing carotid stenosis.

Aged↗
PubMed1988

Regional depletion of adenosine triphosphate, phosphocreatine, and glucose in ischemic hippocampus.

The selective vulnerability of pyramidal neurons in the CA1 hippocampal region in ischemic rat brain may be preceded by regional alterations of energy metabolism during early reperfusion. We measured ATP, phosphocreatine (PCr), and glucose in paramedian and lateral CA1 and in an area showing little postischemic cell loss, CA2. ATP levels in paramedian CA1 were depressed immediately after 30 min of ischemia (P less than or equal to 0.02) and remained abnormal after 2 hr of reperfusion (P less than or equal to 0.05). PCr was reduced substantially in both subdivisions of CA1 immediately after ischemia (P less than or equal to 0.04) but returned to normal levels after 2 hr. Glucose levels were depressed in paramedian CA1 and CA2 after ischemia (P less than or equal to 0.02) but corrected with reperfusion. We determined approximately P, the sum of ATP and PCr, in separate experiments investigating regional differences in consumption of high-energy phosphate metabolites during complete ischemia. The approximately P levels of rats subjected to 30 min of reversible ischemia followed by 2 hr of reperfusion showed a different pattern of regional differences from those seen in sham-ischemic animals (P less than or equal to 0.01), indicating a persistent depression of metabolic rate in CA1 during reperfusion. We conclude that regional depletion of high-energy phosphates and alteration of metabolic rate may contribute to the selective vulnerability of the CA1 region during brain ischemia.

Adenosine Triphosphate↗
PubMed1988

Efficacy and mechanism of action of a calcium channel blocker after global cerebral ischemia in rats.

Dihydropyridine calcium channel blockers such as nicardipine are under evaluation for treating acute cerebral ischemia because they may increase cerebral blood flow by causing vasodilation and because they may be cytoprotective in part by limiting production of arachidonic acid metabolites. We demonstrated in a previous study that nicardipine improves postischemic neuronal function, as measured by somatosensory evoked potentials, without reducing the extent of light-microscopic CA-1 hippocampal histologic damage. To characterize further the effect of nicardipine on global ischemic injury, we administered the drug beginning 24 hours before 30 minutes of four-vessel ischemia in Wistar rats. We then measured hippocampal ATP, phosphocreatine, and glucose contents immediately and 2 hours after ischemia, and measured learning ability (working and reference errors) on an eight-arm radial maze beginning 30 days after ischemia. To gain insight into the possible mechanism of action, we measured production of arachidonic acid metabolites (eicosanoids: TXB2 and 6-keto-PGF1 alpha) and hemispheric and hippocampal cerebral blood flow by the [14C]butanol indicator fractionation technique immediately and 2 hours after ischemia. Nicardipine was associated with fewer working errors (p less than 0.02) but no difference in reference errors. The drug had no effect on energy metabolites, cerebral blood flow, or eicosanoids immediately after ischemia, but ATP, phosphocreatine, and cerebral blood flow all returned to normal levels significantly more rapidly during reperfusion in treated rats. Nicardipine improves behavioral, electrophysiologic, and mitochondrial function after ischemia without preventing cellular damage and improves postischemic reperfusion. The drug's positive effect appears to occur during reperfusion.

Adenosine Triphosphate↗
PubMed1988

Post-stroke management concerns and outcomes.

In the United States alone, there are 1.7 million stroke survivors at any given time, 75% between the age of 55 and 84 years, thereby posing a formidable rehabilitation task. In order to reduce short-term mortality from strokes, management should focus on improved pre-stroke status of high-risk patients and on improved recognition and therapy of medical complications of stroke during the first 3 weeks. Long-term recovery from stroke can be facilitated by skilled rehabilitation and augmented by treatment of depression and other emotional problems. Newer experimental therapies instituted during the first hours after stroke may also prove to accelerate recovery over the first 3 months after stroke.

Cause of Death↗
PubMed1987

Brain extraction of a calcium channel blocker.

Dihydropyridine calcium channel blockers may be effective treatment for acute cerebral ischemia, but the uptake of these drugs into the brain is unknown. A 0.2-ml bolus of [14C]nicardipine hydrochloride and [3H]water was injected into the common carotid arteries of 7 normal and 7 ischemic rats. The corrected first-pass extraction of nicardipine, compared to water, was calculated to be 30.7% into the hemispheres and 42.3% into the hippocampi. The uptake was greater into the ischemic hemispheres (p less than 0.001). These data suggest that dihydropyridines are available to binding sites and calcium channels in neurons.

Animals↗
PubMed1987

Metastatic renal cell carcinoma simulating glomus jugulare tumor.

A 59-year-old man presented with jugular foramen syndrome caused by a mass with roentgenographic and histologic features highly suggestive of a glomus jugulare tumor. However, electron microscopic examination of the surgical specimen revealed features diagnostic of a previously unsuspected renal cell carcinoma. Because primary tumors of the glomus jugulare and metastatic renal cell carcinoma may present with the same clinical and roentgenographic findings and look similar histologically, careful electron microscopic examination of the tumor and urologic screening should be performed in suspected cases of glomus jugulare tumors.

Carcinoma, Renal Cell↗
PubMed1985

Does platelet antiaggregant therapy lessen the severity of stroke?

Data from the Aspirin in Transient Ischemic Attack (AITIA) study, an ongoing study of two platelet antiaggregant drugs, and other published therapeutic trials were reviewed to determine whether the severity of stroke is reduced in patients taking platelet antiaggregants. Data from three of four studies suggest that strokes in treated patients are less severe than those in untreated patients. Further studies evaluating platelet antiaggregant therapy should include assessment of the severity as well as the incidence of stroke.

Aspirin↗
PubMed1984

The significance of carotid stenosis or ulceration.

Data from the medical treatment group of the Aspirin in TIA study were reviewed, and prospective analysis of patients with asymptomatic bruits was performed to see whether carotid stenosis (0 to 49% or 50 to 99%) or ulceration produced an increased risk of ipsilateral TIA or infarct. In symptomatic arteries, greater than 50% stenosis without ulceration implied a higher risk of subsequent symptoms. Ulceration was associated with an increased risk only in nonstenotic vessels. Lesion anatomy was not related to outcome in asymptomatic arteries, and the incidence of cerebral infarct was low. Factors other than anatomy must play a large role in determining subsequent risk.

Angiography↗
PubMed1983

Chiasmal syndrome in sarcoidosis.

Four patients had involvement of the anterior visual pathway by sarcoidosis. In two cases recognition of the systemic disease was delayed because only visual symptoms were present. Three cases had evidence of hypothalamic-pituitary axis dysfunction, with histologically proved granulomatous infiltration of this region. The chiasmal syndrome in sarcoidosis is characterized by a pattern of blindness in one eye, atrophy of the optic discs, and temporal visual field loss in the contralateral eye with variable degrees of pituitary dysfunction. The condition is medically treatable and simulates the clinical and even the roentgenographic appearance of a pituitary tumor.

Adult↗
PubMed1981

Positron imaging in ischemic stroke disease using compounds labeled with oxygen 15. Initial results of clinicophysiologic correlations.

Initial results in over 50 patients with stroke suggest that positron images made during continuous inhalation of carbon dioxide labeled with oxygen 15 and molecular oxygen labeled with oxygen 15 provide data on tissue function that may be relevant to acute stroke management. Five cases illustrate the following findings: 15O-activity patterns observed in areas of ischemic injury or infarction are what one would expect if the 15O distributions represented physiologic functions, such as cerebral blood flow and metabolism. Areas of abnormal 15O activity correlate with the clinical or computed tomographic (CT) localization of the deficit. In studies performed acutely, changes in 15O distributions anticipate alterations in CT scans and may be predictive of outcome. Data related to oxygen metabolism correlate better with tissue viability than do those reflecting cerebral blood flow.

Aged↗
PubMed1981

Carotid artery disease following external cervical irradiation.

A retrospective study of 910 patients surviving at least five years after cervical irradiation for Hodgkin's disease, non-Hodgkin's lymphoma, or primary head an neck neoplasms showed the incidence of stroke following cervical irradiation was 63 of 910 patients (6.3%) during a mean period of observation of nine years. This represents a trend toward an increased risk for this population observed over the same period of time (p = 0.39). A prospective study of 118 similar patients currently living five years after cervical radiotherapy was performed to determine the incidence of carotid artery disease occurring as a consequence of neck irradiation. Abnormal carotid phonangiograms (CPA) were found in 25% of the patients and abnormal oculoplethysmographs (OPG) were found in 17%. These studies represent significant carotid lesions that are not expected in such a population. It is concluded that the carotid stenoses demonstrated are most likely a consequence of prior irradiation. Patients that are five-year survivors of cervical irradiation should have noninvasive vascular laboratory studies performed as part of their routine follow-up examinations in order to detect these carotid lesions while they are occult.

Adolescent↗