Apolipoprotein E4 in schizophrenia: a study of one hundred sixteen cases with concomitant neuropathological examination.
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Biomedical subjects
Publications and source records attributed to M Davidson.
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To assess the empirical basis for add-on augmentation treatments in schizophrenia, this study examined the experimental design components of pharmacologic augmentation trials in schizophrenia and compared them to conventional requirements. A search covering a 5-year period (1988-1992) identified 13 double-blind, placebo-controlled, parallel, add-on neuroleptic augmentation drug trials. The mean number of subjects per trial was 34.5, and the mean number of outcome measures examined was 25.0. The probability for a significant finding by chance was 63%. Mean effect size required to achieve conventional statistical power was 1.6. Mean statistical power (for effect sizes of .5-1.0) was .1-.4. The mean number of subjects actually required for power of .80 was 58-216. The majority of the 13 trials included too few patients and employed too many outcome measures to conclusively prove or disprove therapeutic efficacy. Conclusions drawn from such trials with less than 40-100 subjects or more than one hypothesis must remain tentative at best.
This double-blind study to evaluate long-term efficacy and safety of atorvastatin was performed in 31 community- and university-based research centers in the USA to directly compare a new 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor (reductase inhibitor) to an accepted drug of this class in patients with moderate hypercholesterolemia. Participants remained on a cholesterol-lowering diet throughout the study. One thousand forty-nine patients were randomized to receive atorvastatin 10 mg, lovastatin 20 mg, or placebo. At 16 weeks the placebo group was randomized to either atorvastatin or lovastatin treatment. At 22 weeks, patients who had not met low-density lipoprotein (LDL) cholesterol target levels doubled the dose of reductase inhibitor. Efficacy evaluation was mean percent change from baseline in LDL cholesterol, triglycerides, total cholesterol, high-density-lipoprotein cholesterol, and apolipoprotein B (apoB). Safety profiles as determined by change from baseline in laboratory evaluations, ophthalmologic parameters, and reporting of adverse events were similar for the 2 reductase inhibitors. After 52 weeks, the atorvastatin group maintained a significantly greater reduction in LDL cholesterol (-37% vs -29%), triglyceride (-16% vs -8%), total cholesterol (-27% vs -21%), and apoB (-30% vs -22%) (p <0.05). More patients receiving atorvastatin achieved LDL cholesterol target levels than did lovastatin patients (78% vs 63%, respectively), particularly those with coronary heart disease (37% vs 11%, respectively). Atorvastatin is highly effective and well tolerated in patients with primary hypercholesterolemia with no increased risk of adverse events.
In mitogenic signaling pathways, Shc participates in the growth factor activation of Ras by interacting with activated receptors and/or the Grb-2.Sos complex. Using several experimental approaches we demonstrate that Shc, through its SH2 domain, forms a complex with the cytoplasmic domain of cadherin, a transmembrane protein involved in the Ca2+-dependent regulation of cell-cell adhesion. This interaction is demonstrated in a yeast two-hybrid assay, by co-precipitation from mammalian cells, and by direct biochemical analysis in vitro. The Shc-cadherin association is phosphotyrosine-dependent and is abrogated by addition of epidermal growth factor to A-431 cells maintained in Ca2+-free medium, a condition that promotes changes in cell shape. Shc may therefore participate in the control of cell-cell adhesion as well as mitogenic signaling through Ras.
The possible etiological role of human papillomavirus (HPV) in esophageal carcinogenesis was evaluated in Alaska Natives in whom the incidence of esophageal cancer is 1.3 and 3.8 times higher than in US Caucasian men and women, respectively. Fixed paraffin-embedded esophageal tissues from 32 cases of squamous-cell carcinoma (SCC) and 3 cases of adenocarcinoma (AC) diagnosed between 1957 and 1988 were analyzed by polymerase chain reaction (PCR) and in situ hybridization for HPV DNA sequences. Detection of the human beta-globin gene by PCR was used as a control for sufficiency of DNA and its potential for amplification in the tissue samples. Twenty-five of the tumor tissues were considered adequate for PCR analyses; HPV DNA was detected in 10 of 22 SCCs and was not found in 3 ACs. Seven of the 10 HPV-positive tissues contained sequences from the E6 gene of HPV type 16. Koilocytosis, an epithelial change consistent with HPV infection, was found in 80% of the esophageal squamous-cell tumors with HPV DNA and in 75% of those without HPV DNA. The detection of amplifiable cellular DNA was related to recentness of diagnosis; however, the detection of HPV DNA within amplifiable specimens was not related to recentness of diagnosis. A 413-bp sequence from the L1 open reading frame of HPV 16 from esophageal tissue of 2 patients was identical to sequences previously identified in cervical cells from other Alaska Natives. Our results provide molecular evidence of HPV infection, especially type 16, in archival esophageal cancer tissues from 45% of those patients whose specimens contain adequate DNA for PCR analysis.
BACKGROUND: Cytoarchitectural and neurochemical studies demonstrate disorganization in the cerebral cortex in schizophrenia, which perhaps underlies the severe behavioral disturbances of the disease. This neuronal disarray should be accompanied by synaptic abnormalities. As such, presynaptic proteins have proved valuable indexes of synaptic density and their concentrations have correlated markedly with synaptic loss. Our study sought to determine whether abnormalities exist in the concentrations of presynaptic proteins in the postmortem cerebral cortex of subjects with schizophrenia. METHODS: Presynaptic protein immunoreactivities were assessed in 4 different cerebrocortical regions derived from 16 elderly controls, 19 elderly subjects with schizophrenia, and 24 subjects with Alzheimer's disease. Tissues were assayed with the monoclonal antibodies EP10 and SP4, which recognize synaptophysin, and the monoclonal antibodies SP6 and SP14, which detect syntaxin and synaptosomal-associated protein-25-kd immunoreactivities, respectively. RESULTS: In subjects with schizophrenia relative to controls, presynaptic proteins were increased in the cingulate cortex, but were unchanged in the temporal, frontal, and parietal cortices. In contrast, when cases with Alzheimer's disease were compared with controls, presynaptic proteins were decreased in the frontal, temporal, and parietal samples. CONCLUSIONS: These findings reveal changes in the synaptic organization of the cingulate cortex in schizophrenia relative to other areas examined. These changes are distinct from the deficits in presynaptic proteins observed in Alzheimer's disease.
BACKGROUND: The identification of novel subtypes of the dopamine receptors has renewed interest in the involvement of dopaminergic mechanisms in schizophrenia. We determined the expression of transcripts encoding the dopamine receptors in the brains of schizophrenic patients. METHODS: The levels of the messenger RNA molecules encoding the 5 dopamine receptors were quantified in postmortem brain samples from 16 schizophrenic patients and 9 control subjects. Samples from multiple regions of the prefrontal cortex, primary visual cortex, and striatum were subjected to in situ hybridization followed by quantitative image analysis. RESULTS: Expression of dopamine receptor transcripts did not differ between schizophrenic patients and controls in striatum or visual cortex. Dramatic decreases of dopamine receptor transcripts were found in the prefrontal cortex, but these changes were restricted to the D3 and D4 receptors, and localized to Brodmann area 11 (orbitofrontal cortex). CONCLUSIONS: Cortical dopaminergic neurotransmission may be disrupted in schizophrenia at the level of receptor expression. There appears to be a focal abnormality of D3 and D4 messenger RNA expression in the prefrontal cortex, with down-regulation of both, consistent with prefrontal cortical hypodopaminergia in schizophrenia.
OBJECTIVE: This study examined the clinical characteristics of elderly inpatients associated with retention in a large state hospital during a period of rapid reduction in the inpatient census. DESIGN: During the first year of the study all inpatients age 65 or greater were individually evaluated. Patients remaining in the hospital during the second year were reevaluated and followed for an additional year. Separate statistical analysis of the data allowed for replication of findings. SETTING: The study was conducted at Pilgrim Psychiatric Center, the largest state hospital in New York State. PARTICIPANTS: The entire inpatient population over the age of 65 were included in the study (N = 806). The average age of the sample was 76 years and 70% were assigned a lifetime research diagnosis of schizophrenia. The majority of patients were hospitalized for long periods (mean = 33.9 years) and had significant cognitive impairment. MAIN OUTCOME MEASURES: Cognitive functioning was assessed on the Clinical Dementia Rating Scale. Severity of psychiatric symptoms was evaluated on the PANSS. Occurrence of dangerous behavior and medical and psychiatric treatment were obtained from the patients' medical histories. MAIN RESULTS: The findings, replicated across assessments, were that patients retained had more severe symptoms of excitement, hostility and impulsive behavior than those discharged, while uncooperativeness, delusions, grandiosity and suspiciousness were also more severe in those retained than those discharged. CONCLUSIONS: Elderly patients who are very difficult to place are so characterized because of behavior disorders that are difficult to manage rather than psychotic symptoms, cognitive impairment or medical disorders.
Severe cognitive impairment has been reported in large numbers of geriatric chronic schizophrenic patients in the US, with this impairment also being related to severe negative symptoms and adaptive deficits. It is not clear if this impairment is related to the particular environment of the American state hospitals and would not generalize to other countries. In this study, a sample composed of geriatric (age > 70) chronic schizophrenic patients in London, who were assessed by the Team for Assessment of Psychiatric Services (TAPS) (N = 137), and a group of geriatric chronic schizophrenic patients in a New York psychiatric center (N = 86) were compared for the severity of cognitive impairment and on measures of adaptive functioning. Patients received essentially identical Mini-Mental State Examination (MMSE) scores, but differed on 3/4 measures of adaptive functioning. The correlations among all four aspects of adaptive deficit and MMSE scores were very similar in the two samples, suggesting that cognitive deficits and their relationship with adaptive impairments are relatively invariant across different psychiatric systems of care, while adaptive functioning deficits are more variable and possibly more influenced by environmental factors. These data add to previous results suggesting that cognitive impairment is a common feature in poor outcome geriatric patients with schizophrenia.
Systemic injection of kainic acid (KA) results in characteristic behaviors and programmed cell death in some regions of the rat brain. We used KA followed by recovery at 4 degrees C to restrict damage to limbic structures and compared patterns of immediate early gene (IEG) expression and associated DNA binding activity in these damaged areas with that in spared brain regions. Male Wistar rats were injected with KA (12 mg/kg, i.p.) and kept at 4 degrees C for 5 h. This treatment reduced the severity of behaviors and restricted damage (observed by Nissl staining) to the CA1 and CA3 regions of the hippocampus and an area including the entorhinal cortex. DNA laddering, characteristic of apoptosis, was first evident in the hippocampus and the entorhinal cortex 18 and 22 h after KA, respectively. The pattern of IEG mRNA induction fell into three classes: IEGs that were induced in both damaged and spared areas (c-fos, fos B, jun B, and egr-1), IEGs that were induced specifically in the damaged areas (fra-2 and c-jun), and an IEG that was significantly induced by saline injection and/or the cold treatment (jun D). The pattern of immunoreactivity closely followed that of mRNA expression. Binding to the AP-1 and EGR DNA consensus sequences increased in all three regions studied. This study describes a unique modification of the animal model of KA-induced neurotoxicity which may prove a useful tool for dissecting the molecular cascade that ultimately results in programmed cell death.
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Geriatric chronic psychiatric inpatients often remain in a chronic psychiatric hospital because of serious deficits in adaptive life functions. Because the additional complications and adaptive changes associated with aging have not been considered in previous scales, the Social-Adaptive Functioning Evaluation (SAFE) was developed. The items in the scale measure social-interpersonal, instrumental, and life skills functioning and are designed to be rated by observation, caregiver contact, and interaction with the subject if possible. Interrater and test-retest reliability were examined (n = 60) and convergent and discriminant validity were rated against other relevant measures (n = 50) in separate studies, with all being found adequate. The factor structure of the scale was examined with exploratory factor analysis, revealing a three-factor structure. Finally, predictive validity was examined in a preliminary study of 140 patients, 45 of whom were discharged after the assessment. The results indicate that patients who remained hospitalized could be discriminated from those who were sent to nursing homes or community care on the basis of certain SAFE items and subscales. These results support the use of this instrument in later studies of geriatric psychiatric patients.
Six new DPB1 alleles were identified by PCR-SSOP methodologies in the course of a retrospective study of the role of HLA matching in the outcome of unrelated donor bone marrow transplantation. Sequencing confirmed that five of these alleles (DPB1*5901, *6801, *7101, *7201, and *7301) represent novel combinations of previously described sequence motifs in the variable regions of DPB1; the sixth (DPB1*7001) appears to result from a novel point mutation. These data support previous observations which suggest that multiple mechanisms, including segmental exchange and mutation, appear to be responsible for generating sequence diversity at the DPB1 locus. The extremely low discrepancy rate of 0.1% between the two laboratories which typed the samples, and the ability to predict the new sequences from probe hybridization patterns, indicate that SSOP is an accurate and efficient method for studying polymorphism at DPB1.
Sequence-specific oligonucleotide probe hybridization (PCR/SSOP), which is now routinely used in HLA laboratories to type for alleles of the class II loci, can also detect the presence of previously unknown alleles. In the course of clinical typing for DRB1, we identified two samples with probe hybridization patterns appropriate for DRB1*1313, a previously submitted sequence that had been withdrawn. Direct sequencing showed that the two individuals carried an allele with an exon 2 sequence identical to that previously submitted for DRB1*1313.
OBJECTIVE: This study used a cross-sectional design to examine the frequency of occurrence and severity of 10 different signs of thought disorder in schizophrenic patients across the lifespan. METHOD: Schizophrenic patients, who ranged in age from 19 to 96 years (N = 392), were examined with the Scale for Assessment of Thought, Language, and Communication. The cognitive functioning of the geriatric patients (patients over the age of 64, N = 120) was also assessed. RESULTS: Poverty of speech was more common and more severe in geriatric patients, while four different signs of thought disorder that reflect disconnected speech were less common and less severe in geriatric patients. Analysis of covariance found that the lower severity of disconnection thought disorders in the older patients was not attributable to differences in the amount of speech produced. CONCLUSIONS: Aspects of disconnected speech were less severe in older patients, while the severity and frequency of poverty of speech were greater. These findings suggest that the two previously identified separate dimensions of communication disorder in schizophrenia vary differently with age and possibly in their cognitive and biological underpinnings.
This study examined age-related differences and correlates of deficits on phonological and category fluency tasks performed by schizophrenic patients. Equal numbers (n = 41) of geriatric (age > 64) and nongeriatric chronically hospitalized schizophrenic patients were examined with tests of phonological and category fluency, verbal learning and delayed recall, confrontation naming, and reading, as well as overall estimates of cognitive impairment. Both types of fluency tests were performed very poorly by both groups. Age-related differences were found to be statistically significant. In both groups, category fluency impairments were correlated with deficits in naming, while phonological fluency deficits were best predicted by memory impairments. These data suggest that category fluency impairments are part of a general profile of impaired semantic functioning, whereas phonological fluency deficits may be induced by alterations in information processing capacity.
BACKGROUND: Affective disorders typically have a better outcome than schizophrenia, although recent evidence suggests that some patients with affective disorder have a relatively poor outcome, with cognitive impairments and persistent symptomatology. METHOD: Fifty chronically hospitalised geriatric patients with mood disorders (major depression or bipolar disorder) were compared on the clinical symptoms and aspects of cognitive impairment with 308 geriatric schizophrenic patients who were hospitalised at the same institution. The two samples did not differ in current age or in premorbid education level, but the affective patients had a later age of onset and more females in the sample. RESULTS: There were no overall differences in cognitive functioning between the groups, although the clinical symptom profiles resembled those seen in better outcome patients. CONCLUSIONS: Cognitive impairment is present in poor-outcome patients with affective disorders as well as schizophrenia, suggesting that cognitive impairments predict poor outcome across psychiatric disorders and not just in schizophrenia.
Field trials were conducted in late April to early May of 1995 and 1996 in central Israel to assess the potential for controlling rabies in red foxes (Vulpes vulpes) and golden jackals (Canis aureus) by using vaccine-laden baits. Of the bait types which were field tested, polymer fish meal baits were selected as the most suitable for both species. Fish meal baits containing tetracycline hydrochloride, an oral biomarker, were distributed by four-wheel-drive vehicle at a density of approximately 30 baits/km2 in two test areas of 35 km2. Of the animals which were trapped and euthanized seven to ten days after treatment, 65% of foxes and 56% of jackals gave positive results when tested for the biomarker. These results indicate the potential effectiveness of oral rabies vaccination of these species in Israel and possibly elsewhere in the Middle East, where rabies is a problem in wild canids.