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P Blackwell

Publications and source records attributed to P Blackwell.

7 recordsLinked to original sources
PubMed1998

Absence of neurodegeneration and neural injury in the cerebral cortex in a sample of elderly patients with schizophrenia.

BACKGROUND: The cognitive and functional deterioration that is observed in many "poor-outcome" patients with schizophrenia suggests a neurodegenerative process extending into late life. Previous diagnostic studies have excluded known neurodegenerative diseases as explanations for this dementia. However, we hypothesized that relatively small accumulations of age- or disease-related neurodegenerative lesions occurring in an otherwise abnormal brain could result in deterioration in schizophrenia. METHODS: Postmortem studies were conducted using 23 prospectively accrued elderly persons with chronic schizophrenia for whom clinical ratings had been determined before death, 14 elderly control patients with no neuropsychiatric disease, and 10 control patients with Alzheimer disease. Immunohistochemistry and unbiased stereological counting methods were used to quantify common neurodegenerative lesions (ie, neurofibrillary tangles, amyloid plaques, and Lewy bodies) and cellular reactions to a variety of noxious stimuli (ubiquitinated dystrophic neurites, astrocytosis, and microglial infiltrates) in the ventromedial temporal lobe and the frontal and the calcarine (primary visual) cortices. RESULTS: No statistically significant differences were found between the patients with schizophrenia and the control patients without neuropsychiatric disease for the densities of any of the markers, while both groups exhibited fewer lesions than did the control group with Alzheimer disease. Correlation analyses in the schizophrenia sample failed to identify significant correlations between cognitive and psychiatric ratings and densities of any of the neuropathologic markers. CONCLUSIONS: No significant evidence of neurodegeneration or ongoing neural injury in the cerebral cortex was found in this sample of elderly persons with schizophrenia. Furthermore, the behavioral and cognitive deterioration observed in late life did not correlate with age-related degenerative phenomena.

Age Factors↗
PubMed1998

The importance of CD34+/CD33- cells in platelet engraftment after intensive therapy for cancer patients given peripheral blood stem cell rescue.

The study was designed to determine whether the number of CD34+/CD33- cells given at autologous peripheral blood stem cell (PBSC) rescue after intensive therapy for cancer was a better predictor of platelet engraftment than the total number of CD34+ cells infused. Comparison between the total number of CD34+ cells/kg infused with the number of CD34+/CD33- cells/kg infused showed that, generally, 2 x 10(6) total CD34+ cells contained 1.38 x 10(6) CD34+/CD33- cells. There was poor correlation between the number of CD34+/CD33- and CD34+/CD33+ cells in the graft (r = 0.332). Engraftment times for platelets and neutrophils were evaluated in 68 patients. There was no significant difference between the times for platelets to reach >25 x 10(9)/l or neutrophils to reach >0.5 x 10(9)/l among patients who received > or <2 x 10(6) total CD34+ cells or > or <1.38 x 10(6) CD34+/CD33- cells although the latter was consistently the better predictor. Platelet recovery to >50 x 10(9)/l and >100 x 10(9)/l was delayed significantly in patients who received <1.38 x 10(6) CD34+/CD33-/kg infused (P < 0.02 and P < 0.05, respectively). The number of CD34+/CD33- cells/kg infused was a stronger predictor of platelet recovery than the total number of CD34+ cells infused (P < 0.05 for platelets >50 or >100 x 10(9)/l). Although platelet recovery was delayed significantly in patients who had <4 x 10(4) granulocyte-macrophage colony-forming units (CFU-GM)/kg infused, the time delay between receipt of PBSCs and availability of the colony counts limits the use of this assay to patients who do not require stem cells to be given immediately. Our data suggest that the number of CD34+/CD33- cells given at PBSC rescue provide information about the quality of the graft necessary for long-term platelet engraftment. However, since the percentage of CD34+/CD33- cells shows considerable inter-patient variation, measurement of this cell population may be important in patients who experience poor stem cell mobilization or when a target dose of 2 x 10(6) total CD34+ cells/kg is not achieved.

Adolescent↗
PubMed1995

Prospective clinicopathologic studies of schizophrenia: accrual and assessment of patients.

OBJECTIVE: The purpose of this study was to characterize the neuropsychiatric profile of elderly patients with schizophrenia and establish a patient registry for prospective ante-mortem and post-mortem studies. METHOD: Medical records of all chronically institutionalized patients in eight state hospitals who were over the age of 65 and had a chart diagnosis of schizophrenia (N = 528) were reviewed. Of the potential subjects, 192 were excluded because of clinical histories inconsistent with a diagnosis of schizophrenia, 56 because of insufficient information to establish a psychiatric diagnosis, and 122 because of family members' refusal to give consent for autopsy in the event of death. To date, 81 of the remaining 158 patients have undergone neuropsychiatric evaluation with standard assessment instruments. RESULTS: Mini-Mental State scores of the 81 patients indicated severe dementia, and Functional Assessment Scale scores showed that patients required assistance with activities of daily living. All patients were rated as severely ill on the Brief Psychiatric Rating Scale. Ratings on the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms indicated a predominance of negative symptoms over positive. Of 30 patients who have died to date, research autopsies have been conducted on 26. CONCLUSIONS: Establishing a well characterized, prospective patient registry for clinicopathologic studies of schizophrenia is feasible but labor intensive. Diagnosis of schizophrenia with a high degree of confidence can be achieved by means of detailed chart review and assessment of current neuropsychiatric functioning with standard rating instruments. These data provide a basis for correlations of clinicopathologic factors.

Activities of Daily Living↗