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Biomedical subjects

O B Boyko

Publications and source records attributed to O B Boyko.

At least 37 records · Page 2Linked to original sources
PubMed1994

Prognostic significance of Ki-67 proliferation index in supratentorial fibrillary astrocytic neoplasms.

Histological grading of fibrillary astrocytic neoplasms has proved to be a valuable prognostic tool, but potentially could benefit from more objective data, such as estimates of proliferative rate. The authors have investigated the prognostic utility of quantitative Ki-67 immunoreactivity in a prospective survival analysis of 36 adult patients with astrocytoma, anaplastic astrocytoma, or glioblastoma multiforme diagnosed between 1987 and 1992. A digital image analyzer was used to assay proliferation indices (PIs) in surgical biopsy specimens obtained at first diagnosis (32 of 36) or at a second biopsy of histologically unchanged high-grade disease (4 of 36). A Ki-67 PI of > or = 7.5% was associated with higher histological grade and poorer survival, and the Ki-67 PI was more significantly related to survival (P < 0.001) than histological grade as determined by a modified Ringertz grading system (P = 0.002). Survival analysis within histological grades suggested that astrocytoma patients with PI > or = 3% may be at increased risk for shorter survival than those with PI < 3%.

Adult↗
PubMed1994

MR diagnosis of Creutzfeldt-Jakob disease: significance of high signal intensity of the basal ganglia.

OBJECTIVE: Creutzfeldt-Jakob disease is a rare dementing illness that usually affects older adults. Currently, neuroradiologic examinations play a minor role in the diagnosis of Creutzfeldt-Jakob disease. Several single case reports have noted a distinctive finding of hyperintense signal abnormalities in the basal ganglia on T2-weighted MR images of patients with Creutzfeldt-Jakob disease. In order to assess the diagnostic utility of this finding, we studied the imaging features of four patients with Creutzfeldt-Jakob disease in whom this MR finding was present. MATERIALS AND METHODS: Two neuroradiologists retrospectively reviewed the MR images of four patients who had pathologically proved Creutzfeldt-Jakob disease and signal abnormalities in the basal ganglia on T2-weighted MR images. The patients' clinical findings were also analyzed. RESULTS: The four patients had MR examinations between 6 months and 1 year after the onset of symptoms. In all four cases, the hyperintense signal abnormalities in the basal ganglia on T2-weighted images were diffuse and bilaterally symmetric. The T1-weighted images were normal. A CT scan was obtained on a single patient and was normal. CONCLUSION: Although a lack of signal abnormality in the basal ganglia on MR imaging cannot be used to rule out a diagnosis of Creutzfeldt-Jakob disease, our experience and review of published reports suggest that in the proper clinical setting, bilaterally symmetric, diffuse hyperintense abnormalities in the basal ganglia on T2-weighted images may be a specific sign of Creutzfeldt-Jakob disease.

Adult↗
PubMed1994

Utility of postmortem magnetic resonance imaging in clinical neuropathology.

Over 200 brains were examined by postmortem magnetic resonance imaging to determine the utility of this imaging procedure as an adjunct to the standard postmortem examination of the brain and spinal cord. One unembalmed cadaver was also studied using a conventional 1.5-tesla (T) field-strength unit, and three formalin-fixed sections of the hippocampus were imaged using a high field-strength (7.0-T) prototype imaging system. The postmortem magnetic resonance images proved to be an invaluable aid that complemented the standard pathologic examination of the brain and spinal cord. The compelling advantages of this postmortem radiographic procedure included the three-dimensional aspects of the images; the ability to detect mineral (ie, iron) deposits; small focal lesions such as hemorrhages or infarcts; and the ability to evaluate the extent of cerebral edema. For the same reasons, as well as its archival potential for documenting the topographic distribution of pathologic processes, this technique has great promise for forensic cases. High field-strength (7.0-T) imaging brought the resolution of magnetic resonance to the microscopic level and reaffirmed the potential value of magnetic resonance imaging for diagnostic and investigative studies in which both the histologic and fine radiologic features of lesions are of interest.

Autopsy↗
PubMed1993

Chemotherapy for pilocytic astrocytomas.

BACKGROUND: Although pilocytic astrocytomas (PA) generally are considered benign, a subset of patients with PA have disease progression despite standard treatment with surgery and radiation therapy. The authors report their experience with chemotherapy in this patient group. METHODS: The authors treated 11 patients (4 males and 7 females; median age at diagnosis, 8 years) with pathologically confirmed PA with chemotherapy. In eight patients, tumor progression or recurrence despite prior surgery and radiation therapy led to chemotherapy treatment. In three children younger than 5 years, chemotherapy was given in lieu of radiation therapy immediately after diagnosis (in one patient) or at the time of disease progression after surgery (in two patients). The authors used ten different chemotherapy regimens to treat the 11 patients. RESULTS: Chemotherapy produced clinical and radiographic improvement (R/R) in four (36%) patients, clinical stabilization and radiographic improvement (SD/R) in 1 (9%), clinical and radiographic stabilization (SD/SD) in 3 (27%), and was associated with clinical and radiographic progression (PD/PD) in 3 (27%). Three of the five patients with radiographic improvement had a greater than 75% reduction of maximal cross-sectional tumor area. Hematologic toxicity resulted in dose reductions in 43 of 110 (39%) total courses of chemotherapy. There were three hospitals admissions for fever and neutropenia and one chemotherapy-related death. CONCLUSIONS: The authors conclude that chemotherapy may benefit those with progressive inoperable PA. Chemotherapy may delay the need for radiation therapy in young patients with unresectable PA requiring treatment. PA may be a chemosensitive primary brain tumor.

Adolescent↗
PubMed1993

Multiple fraction-per-day radiotherapy for patients with brain stem tumors.

Brain stem tumors are among the most resistant brain tumors to therapy. The majority progress within 18 months of diagnosis and treatment. Multiple-fraction-per-day (MFD) radiotherapy would theoretically allow higher total doses of radiotherapy to be delivered in order to improve local tumor control without increasing neurotoxicity secondary to treatment. Seventeen patients with brain stem tumors were evaluated and treated at Duke University Medical Center (DUMC) from 1985 to 1991 with a MFD regimen. Six patients were accrued to Pediatric Oncology Group (POG) Protocol 8495 and were not included in this analysis, leaving eleven patients for review. Local fields were treated with fraction sizes of 110 or 117 cGy twice daily. There were 3 patients who received a total of 60.5-68.2 Gy and 8 who received 70.2-71.5 Gy. Initial and follow-up CT and/or MRI studies were available for review on all but one patient. All patients had progression of disease and have died. Median time to tumor progression was 5.8 months. Median overall survival was 11.2 months. There was no significant influence upon time to tumor progression or survival by total radiation dose received. Patients were classified by imaging group per the criteria of Stroink et al. based on review of their pre-treatment CT or MRI scans. One patient had no initial films available, 2 were in Group II (no contrast was given to separate A or B), 3 in IIA, 4 in IIB, and 1 in III. Autopsy in 3 patients failed to demonstrate histologic evidence of injury attributable to radiotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Neuroanatomical substrates of depression in the elderly.

The etiology of depression in the elderly is poorly understood. In this study, magnetic resonance imaging was used to evaluate the role of subcortical structures in the pathophysiology of depression in the elderly. Elderly depressed patients were found to have smaller caudate nuclei, smaller putaminal complexes and in increased frequency of subcortical hyperintensities compared with normal, healthy controls. These findings were more pronounced in patients with late-onset depression. Based on these findings, the authors discuss the role of the basal ganglia in the pathophysiology of depression in the elderly.

Age Factors↗
PubMed1993

Hypercortisolemia and hippocampal changes in depression.

Hypercortisolemia is a frequently observed abnormality in patients with major depression. It has been hypothesized that the hippocampus, as a major feedback site for glucocorticoids, is involved in the pathophysiology of hypercortisolemia. Some have in fact posited that the hippocampus is marked by diminished size in depressed patients with hypercortisolemia. We tested this hypothesis by examining the relationship between hippocampal volume, assessed with magnetic resonance imaging, and hypercortisolemia using the dexamethasone suppression test (DST) in a group of 19 depressed patients. No differences in hippocampal volume were observed between patients and control subjects (n = 30). Within the patient group, DST suppressors did not differ from DST nonsuppressors in hippocampal volume. However, a relationship between hippocampal volume and 11 p.m. cortisol concentration was observed after covariance adjustment for age and sex. Furthermore, significant negative correlations were observed between hippocampal volume and both age of depressive onset and number of hospitalizations. The results of this study therefore provide limited support for the hypothesis regarding an essential role of the hippocampus in the neuroendocrine elevation of glucocorticoids in depression.

Adult↗
PubMed1993

In vivo quantitation of basal ganglia and thalamic degenerative changes in two temporal lobectomy patients with affective disorder.

The authors examined the brain magnetic resonance imaging scans of two epilepsy patients who had temporal lobectomies, one on the right and one on the left, with postoperative symptoms of affective disorders. Degenerative changes of ipsilateral thalamus and putamen after surgery, with coincident affective disorder, were noted. The authors discuss a possible relationship between postlobectomy degeneration and depression.

Adult↗
PubMed1993

Diminished subcortical nuclei volumes in Parkinson's disease by MR imaging.

Parkinson's disease (PD) is associated with changes in the substantia nigra, which communicates with subcortical nuclei. This study investigates subcortical nuclei volume in PD in vivo by magnetic resonance (MR) imaging. Caudate, putaminal, and thalamic nuclei were measured on axial MR images using a point counting method and systematic sampling. PD patients (n = 21) had significantly smaller subcortical nuclei than age- and sex-matched controls (p < 0.001) and depressed patients (p < 0.01). The decline in PD was not correlated with age, sex, or cortical volume. Depressed patients had significantly smaller caudate and putaminal nuclei than controls (p < 0.05 and 0.01, respectively) but thalamic nuclei were not significantly different. Caudate, putaminal, and thalamic nuclei volumes of controls were significantly negatively correlated with age (r = -0.58, p < 0.01; r = -0.77, p < 0.001; r = -0.57, p < 0.01, respectively). Depressed subjects demonstrated a negative trend. Volumetric measurements by MR imaging may be a useful in investigating the role of the basal ganglia in neurological disorders.

Caudate Nucleus↗
PubMed1992

Magnetic resonance imaging of the caudate nuclei in depression. Preliminary observations.

A role of the caudate nucleus in depression has been suggested from relevant clinical conditions, such as patients with Huntington's disease or caudate infarcts, as well as animal studies. Correlations of caudate nucleus disease with depressive symptoms have been limited to autopsy studies and cases of gross pathological disorder, such as large infarcts. We used serial axial high-field magnetic resonance images and an unbiased stereological technique to estimate the volumes of the caudate nuclei in 50 patients who met DSM-III criteria for major depression (23 men, 48.3 +/- 17 years old) in comparison with 50 age- and gender-matched normal controls free of major neurological and psychiatric disorders. Depressed patients had smaller caudate nucleus volumes (5.2 +/- 1.6 cm3) compared with controls (6.2 +/- 1.7 cm3). Right and left caudate nucleus volumes were smaller in depressed patients compared with controls. Age was negatively correlated with caudate nucleus volumes in depressed patients as well as in controls. Caudate nucleus volumes in depressed patients were inversely correlated with the bicaudate and bifrontal indices. These results may be the first demonstration of diminished caudate nucleus volumes in depression and suggest a role for the caudate nucleus in the pathogenesis of major depression.

Age Factors↗
PubMed1992

In vivo assessment of pituitary volume with magnetic resonance imaging and systematic stereology: relationship to dexamethasone suppression test results in patients.

The relationship between dexamethasone suppression test (DST) results and in vivo pituitary volume was studied in 24 psychiatric inpatients. The principles of systematic stereology were used to measure pituitary volume from 3-mm contiguous sagittal spin-echo magnetic resonance (MR) images of the brain. There was no correlation between pituitary volume and 3 p.m. or 10 p.m. postdexamethasone (post-DEX) plasma cortisol concentrations. However, when multiple regression analysis was performed to relate pituitary volume to gender, age, and post-DEX plasma cortisol concentrations, there was a significant relationship between pituitary volume and age, gender, and 10 p.m. post-DEX cortisol plasma concentration. This is the first study to demonstrate a method that directly measures, rather than estimates, in vivo pituitary volume. Furthermore, it suggests that activation of the hypothalamic-pituitary-adrenal axis in psychiatric patients, as manifested by elevated post-DEX cortisol concentrations, may influence pituitary volume.

Adult↗
PubMed1992

Posterior fossa abnormalities in major depression: a controlled magnetic resonance imaging study.

High-field magnetic resonance (MR) images were used to study posterior fossa morphology in 27 patients with major depression and 36 normal control subjects. Depressed patients demonstrated smaller brain stem and cerebellar vermis than controls. These differences were highly significant for the anterior cerebellar vermis and medulla. There was also a striking age-related decline in midbrain size in depressed patients as well as in controls. Our results are consistent with several lines of evidence implicating a role for the cerebellar vermis in affective disorders and, in addition, provide the first MR documentation of the differential effects of aging on posterior fossa morphology in normal subjects compared with patients with major depression.

Adult↗
PubMed1991

Magnetic resonance findings in patients with early-onset Alzheimer's disease.

The magnetic resonance scans of 22 patients with early-onset Alzheimer's disease (AD) were compared to 16 age-matched neurologically normal controls for the presence of white matter subcortical hyperintensities (SCH) and periventricular hyperintensities (PVH). Patients with AD were significantly more likely to have evidence of PVH (p less than 0.01) than age-matched controls. There was no significant difference between the two groups in either the frequency of SCH or the size of the largest lesion. Within the AD group, there was no difference demonstrated in the location of the SCH, either in the anterior-posterior plane or between the two hemispheres. Patients with AD more frequently demonstrated ventriculomegaly (p less than 0.001) and sulcal widening (p less than 0.05) compared with controls. This study suggests that the SCH seen in early-onset AD patients on MRI are related more to the aging process than to the AD process and that the increased frequency of PVH may have a relationship to the disease process.

Aged↗
PubMed1991

Platelet [3H]-imipramine binding and leukoencephalopathy in geriatric depression.

We examined the relationship between platelet [3H]-imipramine binding and leukoencephalopathy as assessed by 1.5 Tesla Magnetic Resonance Imaging (MRI) in 21 elderly depressed patients who satisfied DSM-III criteria for major depression. Both drug-free platelet [3H]-imipramine binding and brain MRI studies were obtained during the same episode of depression. Our findings show a significant inverse relationship between frequency of subcortical hyperintensity (SCH) and the number (Bmax) of platelet [3H]-imipramine binding sites. Patients with Bmax less than 850 fmol/mg protein had significantly larger SCH compared with patients with a higher Bmax. These data provide further support to the potential use of platelet [3H]-imipramine binding studies and brain MR imaging as diagnostic adjuncts in geriatric depression and suggest, moreover, that these two biological markers may be linked in geriatric patients with depression.

Aged↗
PubMed1991

Pituitary abnormalities in eating disorders: further evidence from MRI studies.

1. The frequent occurrence of hypothalamo-pituitary dysfunction in patients with eating disorders as well as prior reports that nutritional and endocrine status influence pituitary morphology, led us to hypothesize that pituitary size and shape may be altered in patients with eating disorders. 2. Magnetic resonance imaging (MRI) does not use ionizing radiation and is currently one of the most feasible modalities available to study the pituitary gland in vivo. Using MRI, we have previously reported in a preliminary study that female patients with eating disorders had significantly smaller pituitary glands than controls. In addition MRI excluded any pituitary mass lesions. 3. In this report, we confirm our previous MRI findings and provide further evidence of pituitary abnormalities in an expanded sample of eating disorder patients. Preliminary data on pituitary volume estimates from MRI scans are provided for a subset of patients and controls.

Adolescent↗
PubMed1991

A magnetic resonance imaging study of putamen nuclei in major depression.

The basal ganglia are recognized as putative mediators of certain cognitive and behavioral symptoms of major depression. Moreover, patients with basal ganglia lesions have repeatedly exhibited significant affective symptomatology, including apathy, depressive mood, and psychosis. Using high resolution, axial T2 intermediate magnetic resonance images, and a systematic sampling stereologic method, we assessed putamen nuclei volumes in 41 patients with major depression (DSM-III) and 44 healthy volunteer controls of similar age. Depressed patients had significantly smaller putamen nuclei compared with controls. Age was negatively correlated with putamen size in both groups. These results are the first demonstration of diminished putamen volumes in depression and further support a role for basal ganglia structures in the etiopathogenesis of depression.

Adult↗