A comparative proteome analysis of hippocampal tissue from schizophrenic and Alzheimer's disease individuals

The proteins expressed by a genome have been termed the proteome. Comparative proteome analysis of brain tissue offers a novel means to identify biologically significant gene products that underlie psychopathology. In this study we collected post mortem hippocampal tissue from the brains of seven schizophrenic, seven Alzheimer's disease (AD) and seven control individuals. Hippocampal proteomes were visualised by two-dimensional gel electrophoresis of homogenised tissue. A mean of 549 (s.d. 35) proteins were successfully matched between each disease group and the control group. In comparison with the control hippocampal proteome, eight proteins in the schizophrenic hippocampal proteome were found to be decreased and eight increased in concentration, whereas, in the AD hippocampal proteome, 35 proteins were decreased and 73 were increased in concentration (P<0.05). One protein, which was decreased in concentration in both diseases, was characterised as diazepam binding inhibitor (DBI) by N-terminal sequence analysis. DBI can regulate the action of the GABA(A) receptor. Protein changes involved 6% of the assessed AD hippocampal proteome, whereas, in schizophrenia protein changes involved less than 1% of the assessed hippocampal proteome. We conclude that schizophrenia has a subtle neuropathological presentation and comparative proteome analysis is a viable means by which to investigate diseases of the brain at the molecular level.     

The effect of ultra-high molecular weight polyethylene wear debris on MG63 osteosarcoma cells in vitro

BACKGROUND: Focal osteolysis due to ultra-high molecular weight polyethylene wear debris involves effects on both bone resorption and bone formation. METHODS: The response of MG63 osteoblast-like osteosarcoma cells to ultra-high molecular weight polyethylene wear debris isolated by enzymatic digestion of granulomatous tissue obtained from the sites of failed total hip arthroplasties was examined. Scanning electron microscopy, particle-size analysis, and Fourier transform infrared spectroscopy were used to characterize the number, morphology, size distribution, and chemical composition of the particles. Cell response was assessed by adding particles at varying dilutions to confluent cultures and measuring changes in cell proliferation (number of cells and [3H]-thymidine incorporation), osteoblast function (alkaline-phosphatase-specific activity and osteocalcin production), matrix production (collagen production and proteoglycan sulfation), and local cytokine production (prostaglandin-E2 production). RESULTS: The mean size of the particles was 0.60 micrometer, and 95 percent of the particles had a size of less than 1.5 micrometers. The number of particles per gram of tissue ranged from 1.39 to 3.38x10(9). Three of the four batches of particles were endotoxin-free. Exposure of the cells to particles of wear debris significantly increased the number of cells (p<0.05) and the [3H]-thymidine incorporation (p<0.05) in a dose-dependent manner. In contrast, the addition of particles decreased alkaline-phosphatase-specific activity and osteocalcin production. Collagen production and proteoglycan sulfation were also decreased, while prostaglandin-E2 synthesis was increased by the addition of particles. CONCLUSIONS: Ultra-high molecular weight polyethylene particles isolated from human tissue stimulated osteoblast proliferation and prostaglandin-E2 production and inhibited cell differentiation and matrix production. These results indicate that particles of wear debris inhibit cell functions associated with bone formation and that osteoblasts may produce factors in response to wear debris that influence neighboring cells, such as osteoclasts and macrophages. CLINICAL RELEVANCE: Particles of wear debris, especially ultra-high molecular weight polyethylene, have been implicated in the loosening of implants and the development of osteolysis. The present study shows that particles of ultra-high molecular weight polyethylene isolated from human tissue inhibit osteoblast functions associated with bone formation. In addition, particles of wear debris induced osteoblasts to secrete factors capable of influencing neighboring cells, such as osteoclasts and macrophages. These results suggest that osteoblasts may play a role in the cascade of events leading to granuloma formation, osteolysis, and failure of orthopaedic implants.     

Identification of bacterial pathogens in patients with endophthalmitis by 16S ribosomal DNA typing

PURPOSE: To determine whether sequence analysis of 16S ribosomal DNA (rDNA) can be used to detect bacterial pathogens in patients with postoperative endophthalmitis. METHODS: In 10 eyes of 10 patients, vitreous specimens were collected for culture and rDNA typing. Variable segments of each ribosomal DNA specimen were amplified by polymerase chain reaction (PCR), sequenced, and aligned by BLAST, a computer alignment program, against sequences in GenBank at the National Institutes of Health. RESULTS: Specimens were available from five eyes with bacterial endophthalmitis diagnosed by Gram stain or culture. Amplified 16s rDNA sequences from the eyes of three patients were identical to microbiologic results. Polymerase chain reaction results were negative in two cases in which unusual organisms were detected. All five control specimens from patients with nonbacterial endophthalmitis or uveitis were PCR negative. Approximately 48 to 72 hours are required under ideal conditions for final species identification with this ribosomal typing technique. CONCLUSIONS: 16S rDNA typing shows potential as a relatively rapid technique for identifying bacteria in vitreous samples.     

Prostate cancer old problems and new approaches

Rates of prostate cancer (PCa) have increased so dramatically over the last decade that the age adjusted incidence rate for PCa is now greater than that any other cancer among men in the United States. This review, published as a three part series, provides a state-of-art assessment of the PCa problem in its divergent aspects.Part 1 covers epidemiology, incidence and progression. Several epidemiological studies have demostrated that first degree male relatives of men with PCa are at increased risk of developing the disease. Familial and genetic factors as well as medical, anthropometric, dietary, hormonal and occupational factors involved in PCa are discussed. Postmortem examination of the prostate in men without evidence of PCa documented a high frequency of adenocarcinoma. Latent disease occurred as early as the second decade of life. Although there is no significant difference in incidence between Caucasian and African-American males, high grade prostatic intraepithelial neoplasia (HGPIN) is higher in the latter group. While dietary fat, androgens and certain environmental factors may be determinants for PCa, the exact mechanism of tumorigenesis is still relatively unknown. The current thinking of the role of genomic instability, chromosomal alterations, tumor suppressor genes and the androgen receptor are explored.     

Muscarinic1 and 2 receptor mRNA in the human caudate-putamen: no change in m1 mRNA in schizophrenia

Studies using tissue obtained at autopsy suggest that changes in cholinergic neurons could be important in the pathology of schizophrenia.1-4 We have previously reported a decrease in [3H]pirenzepine binding5 and [3H]AF-DX 384 binding6 to caudate-putamen (CP) from subjects who had schizophrenia. Under the conditions chosen, [3H]pirenzepine would predominately bind to muscarinic1 (M1) and muscarinic4 (M4) receptors,7whereas [3H]AF-DX 384 would mainly bind to muscarinic2 (M2) and M4 receptors.8 Given the relative concentrations of M1, M2 and M4 receptors in the human CP and the magnitude of the decreases in radioligand binding in schizophrenia, our results most likely reflected a change in the density of M1 and M2 receptors in the CP from the schizophrenic subjects. In situ hybridisation has now been used to determine levels of m1 and m2 mRNA in CP from 14 schizophrenic and 16 control subjects previously used for radioligand binding. m2 mRNA in the CP from the schizophrenic and control subjects was below the sensitivity of in situhybridisation. There was no difference in the levels of m1 mRNA in CP from schizophrenic and control subjects (mean +/- SEM: 103 +/- 16 vs106 +/- 17 fmol [35S]oligonucleotide probe g-1estimated tissue equivalents, P = 0.91). In conclusion, data from our radioligand binding studies show decreases in [3H]pirenzepine binding that are likely to reflect a decrease in the density of M1 receptors in CP from schizophrenic subjects. Our data in this study show the absence of a concomitant change in mRNA coding for that receptor.     

Are Patients with Multiple Endocrine Neoplasia Type I Prone to Premature Death?

Multiple endocrine neoplasia type I (MEN-I) is an autosomal dominant disorder characterized by endocrinopathies involving the anterior pituitary gland, parathyroid glands, and pancreas. The long-term prognosis for patients affected with this disorder is uncertain. To better characterize this prognosis, we performed a retrospective review of all patients with MEN-I treated at a single institution during the period 1951–1997. A group of 233 patients served as the study population. Their records were analyzed for confirmation of diagnosis, treatments received, long-term survival, and cause of death. Altogether, 108 eight male patients (46%) and 125 female patients (54%) were identified. At the conclusion of the study, 164 (70%) were alive and 69 (30%) were deceased, with a median follow-up for patients alive at last contact of 13.4 years (range < 1 month to 54.3 years). The cause of death was reliably obtained in 60 patients. Of these patients, 17 (28%) died of causes related to MEN-I, most commonly metastatic islet cell tumors (10 patients). The remaining patients died of causes unrelated to MEN-I, most commonly coronary artery disease and nonendocrine malignancies (14% each). The overall 20-year survival of MEN-I patients was 64% (95% CI was 56–72%), and that of an age- and gender-matched upper Midwest population was 81% (p < 0.001). Patients with MEN-I appear to be at increased risk of premature death. Earlier diagnosis and treatment of potentially malignant pancreatic islet cell neoplasms may result in a decrease of this premature mortality.