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Biomedical subjects

J Epps

Publications and source records attributed to J Epps.

9 recordsLinked to original sources
PubMed1997

Subarachnoid hemorrhage in the African-American population: a cooperative study.

The clinical outcome of patients following subarachnoid hemorrhage is complicated by delayed cerebral ischemia and contributing factors such as hypertension. To observe the impact of hypertension and delayed cerebral ischemia on the outcome of a predominantly African-American cohort following subarachnoid hemorrhage, both retrospective (n = 42) and prospective (n = 21) studies were conducted. In the total pool (n = 63), the mean age was 49.7 years (range: 17 to 80) with a preponderance of female patients (70%). Aneurysm formation was significant in the region of the posterior communicating artery. Of the patients reviewed, 73.8% had preexisting hypertension and 45.9% developed delayed cerebral ischemia. Approximately 89% of the patients who suffered from delayed cerebral ischemia had hypertension. Results failed to display any significant beneficial association between the use of the calcium channel blocker nimodipine and delayed cerebral ischemia. Use of the antifibrinolytic drug aminocaproic acid demonstrated a worse patient outcome. It is not recommended that aminocaproic acid be used in this population. Subsequently, due to the proportional occurrence of delayed cerebral ischemia in hypertensive patients following subarachnoid hemorrhage, it is suggested that prophylactic surgical management of unruptured intracranial aneurysms be considered in hypertensive patients. Further study is needed to discern the association between hypertension, delayed cerebral ischemia, and stroke in patients following subarachnoid hemorrhage.

Aminocaproates↗
PubMed1991

Transfusion practice in central Virginia.

Increasing concern about the safety of transfusions and a desire to balance blood supply and blood needs stimulated a regional blood center to study the utilization of blood, rather than simply looking at distribution. A comprehensive survey of transfusion use, including packed red cells (RBCs), fresh-frozen plasma (FFP), and platelets (PLTs), was conducted in 12 Central Virginia hospitals. The medical records of 2579 transfused patients showed that the principal diagnoses in 23 percent of patients involved diseases of the circulatory system and those in 16 percent involved neoplasms, as classified under the diagnosis-related groups. Sixty-six percent (n = 1691) of patients had some type of surgery, with surgical patients overall using 1.9 times as many units of blood (RBCs, FFP, and PLTs) as nonsurgical patients. Mean patient age was 61 years, and the male:female ratio was 48:52 percent. This descriptive analysis of regional blood utilization has facilitated planning for local blood needs, provided indicators for areas of largest blood use, and given this region and others baseline data for future comparison.

Adolescent↗
PubMed1980

Chronic cerebellar stimulation in the modulation of behavior.

From March 1976 until March 1979, 28 patients with disabling emotional symptoms were studied in the Psychiatry and Neurosurgery Departments at Tulane University, and pre-selected for cerebellar electrode implantation and subsequent cerebellar stimulation. This series include 12 patients with different types of schizophrenia; 7 epileptic patients with Grand Mal and/or psychomotor attacks, and concomitant psychiatric symptoms; 5 patients with intractable depression; and 4 patients with miscellaneous psychiatric symptoms. Follow-up results are graded as excellent, good, fair and poor. The authors conclude that significant improvement were observed in many patients, and the results, although preliminary and incomplete, are encouraging.

Cerebellum↗
PubMed1976

Multipotentiality of Schwann cells in cross-anastomosed and grafted myelinated and unmyelinated nerves: quantitative microscopy and radioautography.

Cross-anastomoses and autogenous grafts of unmyelinated and myelinated nerves were examined by electron microscopy and radioautography to determine if Schwann cells are multipotential with regard to their capacity to produce myelin or to assume the configuration seen in unmyelinated fibres. Two groups of adult white mice were studied. (A) In one group, the myelinated phrenic nerve and the unmyelinated cervical sympathetic trunk (CST) were cross-anastomosed in the neck. From 2 to 6 months after anastomosis, previously unmyelinated distal stumps contained many myelinated fibres while phrenic nerves joined to proximal CSTs became largely unmyelinated. Radioautography of distal stumps indicated that proliferation of Schwann cells occurred mainly in the first few days after anastomosis but was also present to a similar extent in isolated stumps. (B) In other mice, CSTs were grafted to the myelinated sural nerves in the leg. One month later, the unmyelinated CSTs became myelinated and there was no radioautographic indication of Schwann cell migration from the sural nerve stump to the CST grafts. Thus, Schwann cell proliferation in distal stumps is an early local response independent of axonal influence. At later stages, axons from the proximal stumps cause indigenous Schwann cells in distal stumps from the previously unmyelinated nerves to produce myelin while Schwann cells from the previously unmyelinated nerves to produce myelin while Schwann cells from the previously myelinated nerves become associated with unmyelinated fibres. Consequently, the regenerated distal nerve resembled the proximal stump. It is suggested that this change is possible because Schwann cells which divide after nerve injury reacquire the developmental multipotentiality which permits them to respond to aoxonal influences.

Animals↗
PubMedDate not supplied

Improving credibility of instructions in the balanced placebo design: a misattribution manipulation.

Research using the balanced placebo design seeks to differentiate the physiological and psychological effects of drinking alcohol. Questions regarding the validity of the design center about experimenter instructions, particularly in the antiplacebo cell at higher blood alcohol content (BAC) levels. This study tested the plausibility of two misattribution strategies designed to reduce the conflict between experimenter instructions and internal cues of drunkenness. Forty-two participants (BAC = .055) were told that they received no alcohol, with internal cues of drunkenness said to be produced by a (sham) second drug, a (placebo) tachistoscopic display, or no misattribution given. The placebo drug group reported less alcohol intoxication without reporting less physical impairment than the control or tachistoscopic groups. Doubt of instructions was expressed more frequently in the control group than in the placebo drug group. Mean time to first reported doubt of experimenter instructions was longer for the placebo drug group. A manipulation check designed to account for demand effects indicated that instituting the pharmacologic misattribution increased the success of the manipulation over the control group. Providing a credible attribution for internal symptoms of drunkenness makes experimenter's instructions more credible, improving the validity of the antiplacebo cell of the balanced placebo design.

Adult↗