Association between catechol O-methyltransferase genotype and violence in schizophrenia and schizoaffective disorder

An 18-month-old dog was examined because of ascites of 1 month's duration. Typical causes of ascites, including hepatic failure, heart failure, and protein-losing enteropathy, were ruled out. The dog's history included being hit by a car 6 months earlier, and the caudal vena cava had an S shape on thoracic radiographs. In addition, the abdominal fluid had a high protein concentration and low cellular content. These findings were all consistent with a diagnosis of postsinusoidal hypertension secondary to obstruction of hepatic venous outflow (Budd-Chiari-like syndrome). During exploratory thoracotomy, the pericardium appeared to have been torn from the heart and was partially wrapped around the caudal vena cava, causing a constriction. The pericardium was removed and the dog recovered without any further complications. Blunt trauma has been previously reported to cause kinking of the caudal vena cava and Budd-Chiari-like syndrome in dogs; but in these dogs, clinical signs of ascites developed a few days to several weeks after the traumatic incident. It appears that, depending on the cause of the hepatic venous outflow obstruction, onset of Budd-Chiari-like syndrome may be delayed for months.     

High and low activity alleles of catechol-O-methyltransferase gene: ethnic difference and possible association with Parkinson's disease

Catechol-O-methyltransferase (COMT) is an enzyme that inactivates catecholamines such as adrenaline, noradrenaline, dopamine, and levodopa. Recently an amino acid change (Val-108-Met) of the COMT protein was found to determine high and low activity alleles of the COMT gene. We genotyped 109 Japanese patients with Parkinson's disease (PD) and 153 controls by using polymerase chain reaction (PCR) amplification and digestion by the restriction enzyme NlaIII. The frequency of low activity allele in the controls was 0.29, which was significantly different from that reported in Caucasians (0.50). When comparison was made between patients with PD and controls, homozygosity for the low activity allele was significantly more common among the patients than among the controls (P = 0.017; odds ratio, 2.8, 95% CI 1.2-6.5), suggesting that homozygosity for the low activity allele may increase susceptibility to PD.     

No association between the K variant of the butyrylcholinesterase gene and pathologically confirmed Alzheimer's disease

The polymorphic K variant of the butyrylcholinesterase ( BCHE-K ) gene recently has been demonstrated to have an elevated frequency in Alzheimer's disease (AD) patients carrying the epsilon4 allele of the apolipoprotein (APO E) gene when compared with a control population. We therefore genotyped a large series of pathologically confirmed AD patients and controls to confirm this association. We found no change in the frequency of this genetic variant, either in the AD group as a whole or in early- or late-onset patients when compared with age-matched controls. Stratification of these groups with reference to the APO E epsilon4 allele also showed no difference between AD and control groups. To determine if a biological effect were present, we also looked at senile plaque and neurofibrillary tangle densities in the frontal, temporal, parietal and occipital cortices in AD patients either carrying or not carrying a copy of the K variant. We found no difference in plaque or tangle load between these two groups in either the total, late-onset or early-onset AD subjects. Stratification of the total AD group in terms of APO E epsilon4 allele possession, and further comparison of plaque and tangle load between carriers and non-carriers of BCHE-K still failed to disclose a relationship between BCHE-K and AD. We conclude that in the population studied here there is no association between BCHE-K and AD, or that if such a relationship exists it is precluded by another, as yet unknown factor.     

Ultraviolet resonance Raman study of drug binding in dihydrofolate reductase, gyrase, and catechol O-methyltransferase

This paper presents a study of the use of ultraviolet resonance Raman (UVRR) spectroscopic methods as a means of elucidating aspects of drug-protein interactions. Some of the RR vibrational bands of the aromatic amino acids tyrosine and tryptophan are sensitive to the microenvironment, and the use of UV excitation radiation allows selective enhancement of the spectral features of the aromatic amino acids, enabling observation specifically of their change in microenvironment upon drug binding. The three drug-protein systems investigated in this study are dihydrofolate reductase with its inhibitor trimethoprim, gyrase with novobiocin, and catechol O-methyltransferase with dinitrocatechol. It is demonstrated that UVRR spectroscopy has adequate sensitivity to be a useful means of detecting drug-protein interactions in those systems for which the electronic absorption of the aromatic amino acids changes because of hydrogen bonding and/or possible dipole-dipole and dipole-polarizability interactions with the ligand.     

Apolipoprotein E and B alleles in Parkinson's patients

Parkinson's patients were genotyped for the apolipoprotein E alleles as well as polymorphisms at the apolipoprotein B loci to determine whether they were at risk for late onset Alzheimer's disease or coronary disease. The Parkinson's patients were at no greater risk for either disease than were the control spouses. The frequency for the APOE4 allele was 11% compared with the spouses, 10%. Interestingly, 20% of the patients had the 2/3 genotype which may have a protective effect from late onset Alzheimer's disease.     

No association between the 20210 G/A prothrombin gene mutation and premature coronary artery disease

The 20210 G/A prothrombin gene mutation is associated with an increased risk of venous thrombosis but whether there is an association of the mutation with premature coronary artery disease and acute myocardial infarction remains unclear. To further assess the role of the G/A genotype as a risk factor for arterial vascular disease, we performed a case-control study of 644 patients aged less than 50 years with angiographically proven coronary artery disease, 402 of whom had myocardial infarction, and 679 unrelated healthy control subjects aged less than 50 years, randomly selected from the electoral roll. The prevalence of the G/A genotype was 2.5% in patients with coronary artery disease, and 3.2% in control subjects (odds ratio 0.8; 95% confidence interval 0.35 to 1.83). The mutation was not more frequent among patients with a history of myocardial infarction (2.2%, odds ratio 0.7; 95% confidence interval 0.27 to 2.05), and there was no evidence of an interaction between the prothrombin mutation and conventional cardiovascular disease risk factors. There was no association between genotype and extent of angiographic coronary artery disease (p=0.73). We conclude that the 20210 G/A prothrombin gene mutation is not a major risk factor for premature coronary artery disease in our predominantly Caucasian Australian population.     

Mutation, sequence analysis, and association studies of alpha-synuclein in Parkinson's disease

A mutation within the alpha-synuclein gene on human chromosome 4 has been reported to segregate with PD in an Italian family. We screened a sample of familial cases of PD for mutation in the alpha-synuclein gene. None of the familial cases of PD carried a mutation within the alpha-synuclein gene, and no association was detected between PD and alleles of a dinucleotide repeat marker within the alpha-synuclein gene. We conclude that variation within the alpha-synuclein gene does not play a significant role in the risk for PD in our sample.     

Neuropsychological and psychiatric differences between Alzheimer's disease and Parkinson's disease with dementia

OBJECTIVE: To examine neuropsychological and neuropsychiatric differences between patients with probable Alzheimer's disease and patients with Parkinson's disease and dementia. METHODS: Thirty three patients with probable Alzheimer's disease and 33 patients with Parkinson's disease and dementia were matched for age, sex, and mini mental state examination scores and given a battery of neuropsychological and neuropsychiatric tests. RESULTS: Patients with Parkinson's disease with dementia had a significantly higher prevalence of major depression than patients with Alzheimer's disease; patients with Alzheimer's disease showed more severe anosognosia and disinhibition than patients with Parkinson's disease. Whereas no significant between group differences were found on tests of memory and language, demented patients with Parkinson's disease had a significantly greater impairment on a test of visual reasoning than patients with Alzheimer's disease. CONCLUSION: There were significant psychiatric differences between patients with Alzheimer's disease and demented patients with Parkinson's disease, but neuropsychological differences were restricted to a single cognitive domain.     

No evidence for systemic oxidant stress in Parkinson's or Alzheimer's disease

Oxidant stress secondary to dopamine metabolism has been proposed as a pathogenic factor in the development of Parkinson's disease. Biochemical abnormalities extending beyond the central nervous system have been identified in patients with this condition. Previous investigators have found abnormally elevated concentrations of the lipid peroxidation product, malondialdehyde, in the plasma and serum of patients with Parkinson's disease. We attempted to replicate these findings but controlled for other factors that could influence malondialdehyde levels. We detected no significant elevations in mean serum malondialdehyde concentrations in either levodopa-treated or untreated patients with Parkinson's disease, compared to normal controls; similarly, no elevation was found in a group of patients with dementia of Alzheimer's type. On the other hand, a group of subjects with diabetes mellitus but no neurodegenerative disease had significantly elevated mean serum malondialdehyde levels, consistent with previous studies of diabetic patients. Autoxidation is one of the two major routes by which dopamine and dopa metabolism may generate oxygen free radicals. We analyzed the autoxidation product of dopa, 5-S-cysteinyl-dopa, in the plasma of these same groups of patients with neurodegenerative disease and normal controls; no significant differences were identified. Serum concentrations of two other antioxidant substances, alpha-tocopherol and uric acid, were also statistically similar in these groups. In conclusion, analysis of several blood products relevant to oxidant stress, including malondialdehyde, 5-S-cysteinyl-dopa, alpha-tocopherol, and uric acid, failed to distinguish patients with Parkinson's disease or dementia of Alzheimer's type from controls.     

No association between c-myc amplification and TP53 mutation in sarcoma tumorigenesis

Accuracy of dose delivery at low monitor unit setting is studied for a dual photon energy linear accelerator. Dose delivered per MU is found to be constant for both the photon beams for MU settings above 30. For lower MUs there is definite deviation from the calibrated value and the error is found to be increasing as fewer MUs are set for dose delivery. This dose/MU ratio at low MU setting is found to be dose-rate dependent, showing an increasing trend with pulse repetition frequency (PRF). Also, the dosimetric ratio is observed to be mode dependent; its value for an 18 MV beam is almost double that observed in the case of a 6 MV beam at very low MU setting. The magnitude of this error should be determined for each energy so that appropriate corrections can be applied if very low MUs are to be used.     

No primary association between LMP2 polymorphisms and extraspinal manifestations in spondyloarthropathies

We present a case of multifocal tuberculosis of contralateral costo-transverse joints. Even in countries where tuberculosis is common, extrapulmonary multifocal infection is uncommon. Furthermore, a bilateral, symmetric distribution is distinctly unusual. The index of suspicion for tuberculosis should increase when the patient is from a country where tuberculosis is endemic or when a history of AIDS is present.     

No association between the low density lipoprotein receptor-related protein (LRP) gene and late-onset Alzheimer's disease in a community-based sample

It is now commonly known that possession of the epsilon4 allele of the apolipoprotein E (APOE) gene confers an increased risk for both familial and sporadic Alzheimer's disease (AD), in a dose-dependent way. Other genes that may play a role in AD, either through independent association with the disease or through modification of the existing APOE risk, have been reported with conflicting results. One such gene, the low density lipoprotein receptor-related protein (LRP) gene, was recently reported by two groups to be associated with AD, although the groups identified different risk-conferring alleles. Both studies were based on clinic-derived AD populations (one American, one French), and both reported only marginally significant results. We have genotyped a community-based AD and control population at this LRP polymorphism and find no association between the variants at that polymorphism and the occurrence of AD. Further, despite the biochemical relationship between LRP and the ApoE protein, we find no significant statistical interaction between the alleles at these loci.     

Genetics of Parkinson's disease

For the past 40 years, research into Parkinson's disease (PD) has been predominantly the province of epidemiologists interested in pursuing the connection between the disease and environmental factors such as viral infection or neurotoxins. Hereditary influences were actually discounted because of a high monozygotic twin discordance rate found in studies that were later shown to be inadequate and inconclusive. There has recently been a resurgence of interest in investigating hereditary factors in PD when it became more and more apparent that a positive family history was a major risk factor for the disease. Meanwhile, it also became increasingly apparent from neuropathological studies that the common, idiopathic form of Parkinson's disease had, in fact, a pathological correlate, i.e., the existence of Lewy bodies, an eosinophilic cytoplasmic inclusion body, distributed diffusely throughout the substantia nigra, hypothalamus, hippocampus, autonomic ganglia and olfactory tracts. Although candidate gene approaches to linkage in PD families have not been rewarding, a genome wide scan mapped PD to 4q21-23 in one large family with PD with diffuse Lewy bodies, where a candidate gene, alpha-synuclein, resides. This gene encodes a presynaptic protein of which a peptide fragment is known to be a constituent of Alzheimer's disease plaques. The identification of a missense mutation in the alpha-synuclein gene in four independent PD families suggests that at least some fraction of familial PD with diffuse Lewy bodies is the result of an abnormal protein that interferes with normal protein degradation leading to the development of inclusions and ultimately neuronal cell death. There may be common pathogenetic mechanisms involved in alpha-synuclein mutations in PD and beta-amyloid and presenilin gene mutations in Alzheimer's disease.