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Biomedical subjects

D R Gress

Publications and source records attributed to D R Gress.

29 records · Page 2Linked to original sources
PubMed1997

The safety and efficacy of cyclosporine A in the prevention of vasospasm in patients with Fisher grade 3 subarachnoid hemorrhages: a pilot study.

OBJECTIVE: To evaluate the safety and any potential effect of cyclosporine A (CycA) in preventing cerebral vasospasm. METHODS: Nine patients with Fisher Grade 3 subarachnoid hemorrhages were studied. After a loading dose of 7.5 mg/kg of CycA was administered every 12 hours for two doses, enteral treatment with CycA was started within 72 hours of the onset of the subarachnoid hemorrhage. Whole blood CycA levels were titrated to maintain levels of 50 to 400 ng/kg. Transcranial doppler ultrasonography was performed daily. Middle cerebral artery velocities were used to assess the degree of vasospasm. Angiography was performed to confirm the vasospasm in symptomatic patients, or it was performed if transcranial doppler ultrasonograms were unobtainable. Patients were treated with a standard pharmacological regimen of nimodipine. Induced hypertension, hemodilution, and hypervolemia were instituted at the discretion of the neurosurgical team. Intra-arterial papaverine was infused into the vasospastic vessels of three recalcitrant patients. Outcome was assessed at 6 months with the Glasgow Outcome Scale. RESULTS: All the patients displayed evidence of vessel narrowing, which was disclosed by transcranial doppler ultrasonography or angiography. Five patients developed ischemic deficits, two were treated with intra-arterial papaverine, and three died of complications secondary to vasospasm. No significant hepatic, renal, or infectious complication developed as a result of the administration of CycA. CONCLUSIONS: CycA proved safe to use but failed to prevent the development of cerebral vasospasm or delayed ischemic deficits in patients considered at high risk.

Adolescent↗
PubMed1994

Stroke. Revolution in therapy.

Stroke remains the third leading cause of death in this country, although recent advances in both clinical and basic science research have revolutionized the concept of stroke. Studies of primary and secondary stroke prevention have now documented the means to prevent thousands of cases of stroke each year. Three distinct strategies are evolving for intervention in the acute stroke process. Evidence is clear that ischemia leads to a toxic accumulation of intracellular calcium, in part mediated by excitatory neurotransmitters such as glutamate. Glutamate antagonists have shown clear benefit in experimental stroke models, and early clinical trials are underway. Acute revascularization to restore perfusion is also feasible and may minimize the extent of infarction. Studies of fibrinolytic agents are promising, with randomized clinical studies being done. While reperfusion is desired, it may be associated with additional neuronal injury. The development of anaerobic metabolism followed by reperfusion and aerobic conditions favors oxidation and free-radical formation. This mechanism of injury can be decreased by agents known to scavenge free radicals, and clinical trials are also testing this. This revolution in the understanding of ischemia, as well as the outpouring of new pharmacologic agents, is making stroke a true neurologic emergency requiring immediate intervention.

Animals↗
PubMed1993

Effect of low-intensity warfarin anticoagulation on level of activity of the hemostatic system in patients with atrial fibrillation. BAATAF Investigators.

BACKGROUND AND PURPOSE: The Boston Area Anticoagulation Trial for Atrial Fibrillation (BAATAF) demonstrated that low-intensity warfarin anticoagulation can, with safety, sharply reduce the rate of stroke in patients with nonvalvular atrial fibrillation. The beneficial effect of warfarin was presumably related to a decrease in clot formation in the cardiac atria and subsequent embolization. METHODS: To assess the effect of warfarin therapy on in vivo clotting in patients in the BAATAF, we measured the plasma level of prothrombin activation fragment F1+2. One sample was obtained from 125 patients from the BAATAF; 62 were taking warfarin and 63 were not taking warfarin (control group). RESULTS: The warfarin group had a 71% lower mean F1+2 level than the control group (mean F1+2 of 1.57 nmol/L in the control group compared with a mean of 0.46 nmol/L in the warfarin group; P < .001). F1+2 levels were higher in older subjects but were consistently lower in the warfarin group at all ages. Fifty-two percent of patients in the control group were taking chronic aspirin therapy at the time their F1+2 level was measured. Control patients taking aspirin had F1+2 levels very similar to control patients not taking aspirin (mean of 1.52 nmol/L for control patients on aspirin compared with 1.64 nmol/L for control patients off aspirin; P > .1). CONCLUSIONS: We conclude that prothrombin activation was significantly suppressed in vivo by warfarin but not aspirin among patients in the BAATAF. These findings correlate with the marked reduction in ischemic stroke noted among patients in the warfarin treatment group observed in the BAATAF.

Aged↗
PubMed1992

The effect of aspirin on the risk of stroke in patients with nonrheumatic atrial fibrillation: The BAATAF Study.

Recent randomized trials have consistently demonstrated the marked efficacy of warfarin in reducing the risk of stroke caused by nonrheumatic atrial fibrillation. These trials have provided conflicting evidence on the effect of aspirin. We report the aspirin analysis from the BAATAF study, a trial in which control patients could choose to take aspirin. There we two strokes in 446 person-years with warfarin (annual rate of 0.45%); eight strokes in 206 person-years with aspirin, most at 325 mg per day (annual rate of 3.9%); and five strokes in 271 person-years among patients taking neither aspirin nor warfarin (annual rate of 1.8%). Simultaneously controlling for the other significant determinants of stroke in the BAATAF study (age, mitral annular calcification, and clinical heart disease), the relative rates (95% confidence interval) of stroke were: (1) warfarin/aspirin = 0.135 (0.029 to 0.64); (2) aspirin/(no aspirin and no warfarin) = 1.95 (0.64 to 5.97); and (3) warfarin/(no aspirin and no warfarin) = 0.263 (0.051 to 1.36). Our "treatment received" analysis argues that warfarin is strikingly more effective than aspirin in preventing stroke in nonrheumatic atrial fibrillation.

Aged↗
PubMed1991

Stroke prevention in nonvalvular atrial fibrillation: a review of prospective randomized trials.

Patients with atrial fibrillation are at risk for cerebral embolism; however, the roles of chronic anticoagulation or antiplatelet therapy for stroke prevention in patients with nonvalvular atrial fibrillation have been controversial. Recently, the results of three large prospective randomized trials that examined the risks and benefits of warfarin or aspirin for stroke prophylaxis in patients with nonvalvular atrial fibrillation were reported. All three studies revealed a reduction in the stroke rate for patients treated with warfarin and a small incidence of major bleeding. One of the studies also reported a reduced stroke rate in aspirin-treated patients. The reduction of thromboembolic events associated with chronic warfarin therapy appears to outweigh the risks of significant bleeding for most patients with nonvalvular atrial fibrillation. Aspirin may offer an alternative for subgroups of patients who are at low risk for stroke or those who are not good candidates for anticoagulation.

Anticoagulants↗
PubMed1987

Rapid response to acyclovir in herpes zoster-associated encephalitis.

A previously healthy patient became acutely encephalopathic, with complete disorientation and amnesia, several days after the onset of thoracic herpes zoster. She had transiently abnormal electroencephalographic results, abnormalities on radionuclide brain scanning, and cerebrospinal fluid pleocytosis. There was no evidence of a toxic/metabolic encephalopathy except for a mildly elevated ammonia level. Intravenously administered acyclovir (30 mg/kg per day) induced a dramatic response, with complete resolution of the encephalopathy within 72 hours and normalization of the electroencephalographic results. The scant clinical experience with the successful use of acyclovir in the treatment of herpes zoster-associated encephalitis is reviewed.

Acyclovir↗
PubMed1985

A case of agnogenic myeloid metaplasia evolving into acute myelogenous leukemia associated with the development of trisomy 11 in bone marrow cells.

An 83-year-old woman who had a 5-year history of agnogenic myeloid metaplasia and a previous normal marrow cell karyotype presented with acute myelogenous leukemia (AML) associated with the development of trisomy 11 in 100% of cultured marrow cells. Isolated trisomy 11 in marrow cells has been reported previously in five cases of AML, suggesting that trisomy 11 is a nonrandom chromosomal aberration associated with AML.

Aged↗
PubMedDate not supplied

Subclavian arteritis and pseudoaneurysm formation secondary to stent infection.

Technically uncomplicated percutaneous angioplasty and stent placement of a left subclavian artery stenosis was performed in a 56-year-old man for treatment of subclavian steal syndrome and vertebrobasilar insufficiency. Six days later the patient was readmitted with Staphylococcus aureus bacteremia and stigmata of septic emboli isolated to the ipsilateral hand. Nine days later he had computed tomography (CT) evidence of a contrast-enhancing phlegmon surrounding the stent. Despite clinical improvement and resolution of bacteremia on intravenous antibiotic therapy, the phlegmon progressed, and at day 21 a pseudoaneurysm was angiographically confirmed. The patient underwent surgical removal of the stented arterial segment and successful autogenous arterial reconstruction. The possible contributory factors leading to stent infection were prolonged right femoral artery access and an infected left arm venous access. Although the role of prophylactic antibiotics remains to be defined, it may be important in cases where the vascular access sheath remains in place for a prolonged period of time.

Aneurysm, False↗
PubMedDate not supplied

MR diffusion imaging of cerebral infarction in humans.

PURPOSE: MR diffusion imaging was performed to investigate changes in water diffusion in patients with cerebral infarction. METHODS: Diffusion maps of the apparent diffusion coefficient (ADC) were created to show local water mobility in the brain tissue in 15 patients. These ADC maps were compared with conventional T2-weighted images. RESULTS: Distinct subregions with different water diffusions were detected, even when the infarcted area appeared homogeneous on a T2-weighted image. The results also show that stroke lesions of the same age can have very different water diffusions. A trend towards an increasing diffusion coefficient in a lesion during the first several days following an acute event was observed in a group of patients imaged at multiple timepoints. CONCLUSION: The measurement of diffusion coefficients in vivo now offers an opportunity for greater understanding of the biophysical changes that occur during the evolution of infarction in humans.

Adult↗