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Biomedical subjects

D W Giang

Publications and source records attributed to D W Giang.

12 recordsLinked to original sources
PubMed1996

Conditioning of cyclophosphamide-induced leukopenia in humans.

This study evaluated whether decrements in peripheral leukocyte counts induced by cyclophosphamide can be conditioned in humans. Ten subjects being treated for multiple sclerosis received four intravenous treatments with cyclophosphamide (unconditioned stimulus) paired with a conditioned stimulus. Subjects received conditioned stimulus plus 10 mg of cyclophosphamide during one of the next two treatments in a double-blind manner. Eight of 10 subjects (P = 0.044) displayed decreased peripheral leukocyte counts following conditioned stimulus. This change may have resulted from classical conditioning processes.

Adult↗
PubMed1994

Clinical diagnosis of multiple sclerosis. The impact of magnetic resonance imaging and ancillary testing. Rochester-Toronto Magnetic Resonance Study Group.

OBJECTIVE: Magnetic resonance imaging, computed tomography, cerebrospinal fluid analysis, and evoked potential testing are used to assist in the diagnosis of patients suspected to have multiple sclerosis (MS). The impact of these tests on a clinician's diagnosis of patients suspected to have MS has not been studied systematically. DESIGN: Clinicians made a diagnosis of each patient following clinical evaluation, again after reviewing the results of magnetic resonance imaging, and finally after reviewing information from other laboratory testing. These diagnoses were compared with the criterion standard of a masked "gold standard" panel reviewing all information after a mean follow-up of 0.9 year. SETTING: The General Neurology Clinic and Multiple Sclerosis Clinic of the University of Rochester (NY). PATIENTS: A consecutive sample of 62 patients diagnosed as having either possible or probable MS following clinical evaluation. MAIN OUTCOME MEASURE: Changes in diagnostic certainty of clinicians following incremental presentation of new laboratory data and the accuracy of such diagnoses. RESULTS: Clinicians used magnetic resonance imaging findings to diagnose definite MS or to eliminate MS from diagnostic consideration in 44% of cases. In these cases, further laboratory testing did not alter clinicians' decisions. In the remaining 56% of cases, in which magnetic resonance imaging did not lead to a diagnosis of definite MS or eliminate MS from diagnostic consideration, further laboratory testing led to such diagnoses in an additional 13% of cases. Gold standard diagnoses were in agreement with the clinician's assessments. CONCLUSIONS: Magnetic resonance imaging aids in the evaluation of patients suspected to have MS; other subsequent studies (computed tomography, cerebrospinal fluid analysis, and evoked potential testing) have less impact. After all studies are performed, about half of such patients still have a tentative diagnosis.

Adult↗
PubMed1992

Multiple sclerosis masquerading as a mass lesion.

Six patients presenting with new neurological deficits underwent magnetic resonance imaging (MRI) that displayed mass lesions leading to diagnoses of tumor or abscess. Biopsy revealed demyelinating lesions.

Adolescent↗
PubMed1991

Abnormal vitamin B12 metabolism in human immunodeficiency virus infection. Association with neurological dysfunction.

An increased prevalence of vitamin B12 deficiency has been reported in patients infected by the human immunodeficiency virus (HIV). We report an unexpectedly high prevalence (20%) of such abnormal vitamin B12 metabolism in a population of HIV-infected patients referred for neurological evaluation. This abnormality was associated with both peripheral neuropathy and myelopathy. A majority of those treated with cyanocobalamin had a therapeutic response. Selected neuropathological results suggest a relationship between vitamin B12 deficiency and vacuolar myelopathy. Vitamin B12 deficiency may be a frequent and treatable cause of neurological dysfunction in patients with HIV infection.

HIV Infections↗
PubMed1989

Transient global amnesia associated with cerebral angiography performed with use of iopamidol.

Transient global amnesia has been associated with cerebral angiography performed with use of ionic agents. Nonionic contrast agents are associated with fewer complications, but complications do occur. The authors describe two patients who developed transient global amnesia after they underwent cerebral angiography with iopamidol. The precise pathophysiologic mechanism remains unclear, but the syndrome is by definition self-limited.

Adult↗
PubMed1988

Vertebrobasilar dolichoectasia: assessment using MR.

We evaluated six patients with vertebrobasilar dolichoectasia (VBD) comparing clinical presentation with magnetic resonance (MR) and computed tomography (CT) imaging. MR diagnosed the condition as well as CT in all cases, but proved superior to CT in delineating the anatomical relationship of the vessels to the neural structures. MR proved especially useful in cases of VBD-associated hydrocephalus and posterior fossa masses. A coexisting tumor was diagnosed by MR in one case.

Aged↗
PubMedDate not supplied

Lorazepam versus diazepam for the treatment of status epilepticus.

A retrospective study was performed to compare intravenous lorazepam and intravenous diazepam in the treatment of status epilepticus. Forty-five episodes of status epilepticus in children between the ages of 2 weeks and 18 years were reviewed. Lorazepam and diazepam proved similar in efficacy of seizure control and incidence of adverse effects. The dose of lorazepam required to control status epilepticus ranged from 0.03 to 0.22 mg/kg with a mean of 0.11 mg/kg (S.D. = 0.05 mg/kg). Among children treated with lorazepam, only children younger than 2 years of age had respiratory depression which required intubation.

Adolescent↗
PubMedDate not supplied

The accuracy of magnetic resonance imaging in patients with suspected multiple sclerosis. The Rochester-Toronto Magnetic Resonance Imaging Study Group.

OBJECTIVE: To design and implement a methodologically rigorous study to examine the accuracy of magnetic resonance imaging (MRI) in a patient population clinically suspected of having multiple sclerosis (MS). DESIGN AND SETTING: Three hundred three patients, who were referred to two university medical centers because of the suspicion of MS, underwent MRI of the head and double-dose, contrast-enhanced computed tomography (CT) of the head. The images were read by two observers individually and without knowledge of the clinical course or final diagnosis. Patients were followed up for at least 6 months and reevaluated clinically with subsequent neurological examination. Final diagnosis (MS or not MS) was made by a panel of neurologists on the basis of the clinical findings at presentation, those that developed during follow-up, and other diagnostic tests. The results of the imaging procedures were excluded to avoid incorporation bias. Diagnostic accuracy was assessed using receiver-operating characteristic analysis and likelihood ratios. RESULTS: Magnetic resonance imaging of the head was considerably more accurate than CT in diagnosing MS. The area under the receiver-operating characteristic curve for MS was 0.82 (compared with 0.52 for CT) indicating that MRI was a good but not definitively accurate test for MS. A "definite MS" reading on an MRI of the head was specific for MS (likelihood ratio, 24.9) and essentially established the diagnosis, especially in patients clinically designated as "probable MS" before testing. However, MRI of the head was negative for MS in 25% and equivocal in 40% of the patients considered to have MS by the diagnostic review committee (sensitivity, 58%). CONCLUSIONS: Magnetic resonance imaging of the head provided assistance in the diagnosis of MS when lesions were visualized. Its ability far exceeded imaging with double-contrast CT. The sensitivity and, therefore, the predictive value of a negative MRI result for MS were, however, not sufficiently high for a normal MRI to be used to conclusively exclude the diagnosis of MS.

Adolescent↗