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DNA sequence data are generally interpreted as favouring Kimura's neutral theory but not without dissent and often with a great deal of controversy with respect to molecular clocks, DNA polymorphism, adaptive evolution, and gene genealogy. Although the theory serves as a guiding principle, many issues concerning mutation, recombination, and selection remain unsettled. Of particular importance is the need for more knowledge about the function and structure of molecules.

The amounts of three adenylyl cyclase (AC) subtypes in membranes from brain obtained post-mortem from patients with dementia of Alzheimer type (DAT) and controls were studied by Western blotting using polyclonal antibodies. AC subtypes were characterized by preabsorption by complementary peptides, species difference, tissue distribution and by using AC-VI-transfected cells. Immunoreactivities of AC-I and AC-II subtypes, which are predominant in brain tissue were decreased 40.5% (p < 0.02) and 52.0% (p < 0.02), respectively in DAT compared with controls. No significant difference in immunoreactivity of AC-V/VI subtypes distributed in various other tissues was observed. Our results are the first to indicate that reduced levels of brain-specific AC subtypes occur in DAT.

We had a case of psychiatric evidence who was homeless and exhibited severe abulia and autism on detention for assault and battery. It was thought that his past history of chronic methamphetamine abuse and his familial history played some part in his showing such symptoms. His mother was alcohol dependent. He was an ACOA (adult child of alcoholics), which might have led to his chronic abuse of methamphetamine. On the other hand, it is well-known fact that the amotivational syndrome induced by marijuana abuse is typified by a diminution of ambition, productivity, and motivation. However, it has been contended that amotivational syndrome is induced not only by marijuana but also by amphetamine and its analogs, cocaine and volatile solvents. Since we positively support this view, we diagnosed the case as amotivational syndrome after long-term methamphetamine abuse. This was also a rare criminal case of amotivational state without hallucinations and delusions after methamphetamine abuse. We suggested that the crime committed in this case was closely related to crime induced by economic problems in residual states of schizophrenic offenders. This could be a case of both ACOA and methamphetamine dependence. There were unresolved alcohol- and drug-related problems in this case. Therefore, careful early intervention in a crisis, cooperation with the authorities and the institutions concerned, and comprehensive rehabilitation should be employed to resolve such alcohol- and drug-related problems.

The effects of repeated administration of ceruletide (100 micrograms/kg/perday, i.p. for 3 days) on perioral movements and the striatal dopamine receptor adenylate cyclase system were examined in rats chronically treated with fluphenazine enanthate (FPZ) (25 mg/kg i.m. every 3 weeks for 30 weeks) and sesame oil-treated (control) rats. After the tenth injection of fluphenazine, the rats started to display five types of perioral movements (teeth chattering, chewing, tongue protrusion, mouth opening and perioral tremors). Moreover, increases in SCH23390 binding and spiperone binding to striatal membranes, were found in the FPZ-treated rats. Furthermore, dopamine receptor-coupled adenylate cyclase activity was potentiated in striatal membranes. High amplitude EMG discharges (8-10 Hz), recorded from the masseter in the FPZ-treated rats occurred concurrently with perioral tremors. Repeated ceruletide (CLT) injections abolished perioral movements, and reversed both the elevated SCH23390 binding and the dopamine stimulated adenylate cyclase (AC) activity to the control level. The effect of CLT on perioral movements, D1 receptors and dopamine-stimulated AC activity continued for 6 days after the final CLT injection. These findings suggest that systemically administered CLT affects the D1 receptor adenylate cyclase system and that an increase of the D1 receptor mechanism may play an important role in the pathogenesis of tardive dyskinesia.

Dementia has been defined generally as an acquired persistent impairment of intellectual function caused by organic brain diseases. The rapidly increasing incidence of dementias has been claimed on the basis of epidemic studies in Japan as well as in Western developed countries. These observations are justified by the facts that most dementias are found in people over the age of 65 years, and that the elderly population is increasing rapidly resulting in both absolute numbers and percentage of the population. In Japan, it is estimated that 1.5 million of demented persons are present. The purpose of this paper is to describe clinical manifestations and morphological alterations of aged and demented individuals, diagnostic process to differential diagnosis to provide knowledgeable approach to management, and adequate care of the demented individuals. In aged brain, there are a variety of morphological changes. Some of these are usually observed in aged brains; atrophy of the brains, loss of neurons, accumulations of lipofuscin. Others observed in pathologically aged brains, or accelerated aging brains are Alzheimer's neurofibrillary tangles, senile plaques, and granulovacuolar degeneration. Psychiatric manifestations associated with aging and dementing diseases are described. It should be realized that clinical manifestations of the demented reflect primarily the topography of the organic lesions in the brain, and functional alterations, and are influenced by psychological and socio-environmental factors.

A case of psychosis accompanied with variable symptoms induced by chronic volatile solvent inhalation is reported in this study. The patient was a 27-year-old male who had abused volatile solvents for 15 years, and was sent to the hospital because of a tonic-clonic seizure. Severe psychomotor excitement was observed on the first day and the 7th day after admission. After 10 days of admission, we observed visual transformation and hyperthermia, which suggested acute toxic symptoms due to a volatile solvent. Furthermore, symptoms such as incoherence, delusions of persecution, and catalepsy were also observed in this case. There have been few reports of multiple neurological and mental symptoms appearing in cases of volatile solvent psychosis. Although we sometimes experience cases of solvent abuse with acute mental symptoms and recurrent excitement after sedation, such symptoms are not always observed because of flashback in the strict sense. Therefore, careful early treatment should be employed to prevent 'secondary excitement'.

Platelet GTP binding protein (G protein) in 25 alcoholics with a first-degree alcoholic relative (family history positive alcoholic; FHP), in 25 alcoholics without alcoholic relatives (family history negative alcoholic; FHN) and in 25 controls without alcoholic relatives was investigated to determine whether this protein is a trait marker for alcoholism. The alcoholic subjects met DSM III-R criteria for alcohol dependence and had been abstinent from alcohol for at least one year. Lowered platelet guanine nucleotide (GppNHp)-stimulated adenylyl cyclase (AC) activity and reduced sensitivity of AC to ethanol were recognized in FHP but not in FHN. Remarkable reduction in ethanol enhancement of functional photoaffinity GTP (azidoanilido GTP; AAGTP) binding to Gs alpha and Gi alpha in platelet membrane was observed in FHP but not in FHN. A quantitative reduction in Gs alpha and GsH alpha (high molecular weight Gs alpha) levels as assessed by immunoblotting was seen in platelet membrane from FHP but not from FHN. These results indicate that the characteristic of platelet G protein may be used as a trait marker for alcoholism.

Recent advances in Alzheimer's disease (AD) research were briefly reviewed. AD is the most common cause of progressive intellectual decline in the aged in the Western world and also in Japan. The AD-affected brain is characterized by numerous amyloid plaques, neurofibrillary tangles, and neuronal losses. The amyloid deposition is considered to be more important because it appears first, and is followed by NFTs. The amyloid is composed of amyloid beta peptide (Abeta), a 40 approximately 42 amino acid fragment of the large membrane protein, amyloid precursor protein (APP). Abeta is cleaved by the proteolytic enzymes, beta, and gamma secretase. Considerable effort has been directed to identify these enzymes, and to find the intracellular compartments where Abeta is generated. The lysosome, or related acidic compartment is one of the candidates. The N and C terminis of the Abeta is known to vary slightly. Biochemical and immunopathological studies implicate that Abeta42 is more important than Abeta40 in the pathogenesis of AD. On the other hand, many missense mutations in APP gene and other genes, e.g. S182, and STM 2 have been identified in familial AD. Neuropathologically, AD is regarded as cerebral Abeta amyloidosis. The AD amyloid is composed of many proteins other than Abeta, designated as amyloid associated proteins. These proteins may play important roles in amyloid formation, since Abeta itself is soluble. Transgenic mice and chloroquine myopathy rat are available as animal models for AD. Elucidation of the roles of these missense mutations, and amyloid associated proteins in the cascade of AD, may provide a breakthrough to therapeutics for AD.

Changes in gamma-aminobutyric acidA (GABAA) receptor function and their relation to cross-tolerance to ethanol (EtOH) were studied in diazepam (DZP)-dependent rats. Physical dependence on DZP was induced in male Fischer rats by using the drug-admixed food method. The 38Cl- influx into cerebral cortical synaptoneurosomes induced by 10 microM GABA in DZP-withdrawn rats was significantly increased, compared with control and DZP-tolerant rats. Although enhancement of GABA-dependent 38Cl- influx by the addition of EtOH and flunitrazepam (FZ) was recognized in the control, there was no such effect of EtOH or FZ in the DZP-tolerant animals. On the other hand, GABA-dependent 38Cl- influx was enhanced by FZ in the withdrawn group. The addition of picrotoxin and bicuculline inhibited GABA-dependent 38Cl- influx in each group. The stimulatory effect of FZ on GABA-dependent 38Cl- influx was inhibited by the addition of Ro 15-1788 in the control group. However, such an inhibitory effect was not observed in the withdrawn group. The antagonistic effect of Ro 15-4513 on EtOH stimulation of GABA-dependent 38Cl- influx observed in the control was not recognized in the withdrawn group. In a [3H]FZ assay of binding to benzodiazepine (BZ) receptors, Bmax values were significantly increased in DZP-withdrawn animals, but decreased in the DZP-tolerant group, compared with the control. When [3H]muscimol binding was examined, the Kd of high-affinity sites of the GABAA receptor in withdrawn rats was significantly lower than in the control. In low-affinity binding sites, the values of Kd and Bmax were significantly decreased, compared with those in the control. The present study indicates that GABAergic transmission involving the regulation of GABA-dependent chloride channels is altered in DZP-dependent rats. Alterations of the GABAA/BZ/chloride channel complex function may be related to the cross-tolerance between BZ and EtOH.

123I-IMP SPECT (SPECT) has been widely used in clinical neuropsychiatry for establishing the clinical diagnosis, and evaluating the course of the disease. However, little is known about the significance of alterations in SPECT. In this paper, we present comparative study between alterations in SPECT and neuropathological findings in the case of Alzheimer's disease (AD). The patient, a 59-year-old female, began to show memory disturbance and the left hemisphere disturbances, non-fluent aphasia, but right hemisphere disturbances, constructional apraxia, visuo-spatial dysfunctions were not notable at the early stage. The neuroimaging also revealed left-side dominant cerebral atrophy in MRI and left-side dominant hypoactive regions in SPECT (especially in parietal lobe). Memory disturbance and non-fluent aphasia gradually progressed after admission. Then, mirror phenomenon and Bálint's syndrome appeared at the age of 63 years. In the advanced stage, hypoactive regions in SPECT were expanded into temporal and frontal areas. The laterality observed at the early stage became unremarkable. The patient died from heart failure at 64 years. Pathological diagnosis was AD. Eleven ROI (region of interests) were determined on each hemisphere in transverse SPECT image. We calculated ROI% (each ROI count/ROI count at central cerebellum). Neuronal cell count (NCC) and amyloid beta protein deposited areas (BDA) were estimated using 3 serial sections stained with Nissl's method and immunostained for amyloid using monoclonal antibody raised against synthetic A beta, mcAb 90/12. Digitized images based on photographs were analyzed with NIH-image 1.45. NCC decreased in number in frontal, temporal, and parietal lobes. Significant asymmetrical reduction of NCC (lt. < rt.) was observed in orbital, superior temporal and angular gyri (p < 0.01). BDA in superior parietal lobule, superior temporal gyrus and superior, middle, inferior frontal gyri were larger than those in precentral gyrus and visual cortex. Asymmetry of BDA (lt. > rt.) was significant in middle temporal gyrus (p < 0.01). ROI% at the early stage was correlated with corresponding NCC (r = 0.49, p < 0.05) and BDA (r = -0.55, p < 0.01), but at the advanced stage was not significantly correlated with corresponding NCC (r = 0.26) and BDA (r = -0.20). It is evident that SPECT shows good correlation with clinical features and pathological alterations during the course of AD. Our observations imply that the changes in SPECT usually precede the appearance of the clinical symptoms. SPECT is very sensitive in detecting the functional decline in certain regions of the CNS. In the case of AD, the hypoactive regions in SPECT at the early stage may indicate functional decline of the neuronal cells, and at the advanced stage, these may indicate the degree of pathological changes, especially neuronal loss and amyloid beta protein deposition.

Alteration in the function of the GABAA receptor complex and its relation to changes in withdrawal signs in diazepam (DZP)-dependent rats were studied. Physical dependence on DZP was induced in male F344 rats by using the drug-admixed food method. After cessation of treatment, withdrawal signs such as spontaneous convulsions were observed and withdrawal scores were maximal at 39 approximately 45 hr after the DZP withdrawal. Furthermore, these withdrawal signs almost disappeared by 159 approximately 168 hr after the DZP withdrawal. GABA-stimulated 36Cl- influx into cerebral cortical membrane vesicles was significantly decreased in rats 0 hr after DZP withdrawal and significantly increased in rats 42 hr after DZP withdrawal compared with control rats Flunitrazepam (FZ)-induced potentiation and an antagonistic effect of Ro 15-1788 on GABA-stimulated 36Cl- influx were observed in control rats. No FZ-potentiated GABA-stimulated 36Cl- influx was observed in rats 0 hr after DZP withdrawal: however, such an effect of FZ was recognized in rats 42 hr and 162 hr after DZP withdrawal. No antagonistic effect of Ro15-1788 on the FZ-induced stimulation was recognized in rats 0 hr and 42 hr after DZP withdrawal but was recognized at 162 hr after DZP treatment, although it was not significant. In a [3H]FZ assay of binding to benzodiazepine (BZ) receptors. Bmax values were significantly decreased in rats 0 hr after DZP withdrawal, but increased at 42 hr after DZP withdrawal, compared with control rats Bmax had almost returned to the control level at 162 hr after DZP treatment rats. In conclusion, these results indicate that functional changes in the GABAA/BZ receptor/CI- channel complex, i.e. increased sensitivity in GABAA receptors and impairment in the functional coupling between BZ receptors and GABAA receptors, may possibly be involved in the biochemical mechanism of the severe withdrawal symptoms appearing after chronic treatment with DZP.

'Closing-in' symptom is defined as a tendency to close-in on the model while performing constructive tasks. This unique symptom is one of the constructional apraxia often observed in Alzheimer's disease (AD), which is considered to be involved in visuospatial dysfunctions. However, little is known about the nature of the symptom and pathophysiology underlying the symptom. In this study, we examined drawing behavior, eye movements of AD (n = 19), multi-infarct dementia (n = 8) and age matched healthy subjects (n = 10). 1) In AD, contrary to age matched healthy subjects, the patients drew slowly with apparent difficulty and drawing behavior was disorganized. The copied figures were incomplete and often fragmented. The spatial relationships of the parts were lost each other during copying a Necker's cube. 2) The characteristic eye movements were observed in AD patients with apraxia, and closing-in symptom. These were consisted of gaze apraxia, and disorders of visual attention appeared similar to Bàlint's syndrome. 3) The eye movements of the AD patients with closing-in symptoms were classified into wandering of fixation, locking of fixation, and mixed types. The 'closing-in' symptoms in copied figures were classified into three types, overlap, adherent, and near types. Then, the wandering type was seen both in near and adherent types, whereas the fixation type was only found in the overlap type. 4) SPECTs showed reduced RI activities in the parieto-occipital and in the frontal regions of AD patients with apraxia and closing-in symptoms. Our results suggest that AD patients may have a difficulty to create abstract space from concrete space. This may also imply regression to a primitive undifferentiated stage where gnostic and practic behavior is not differentiated in terms of space appreciation.

Previous immunohistochemical studies from this laboratory demonstrated that monoclonal antibodies raised against various regions of amyloid precursor protein (APP) (i.e., N-terminus, amyloid beta protein (A beta), and C-terminus) strongly labeled vacuoles in chloroquine-induced myopathy-affected muscle in rats. In this study, we used antibodies end specific for the A beta 40 and A beta 42 species, and a monoclonal antibody to A beta 1-9 which reacts with APP and A beta. Most vacuoles clearly reacted with anti-A beta 1-9, while about half reacted with anti-A beta 42, and only a few reacted with anti-A beta 40. These results demonstrate that vacuoles in chloroquine-induced myopathy-affected muscle contain cleaved A beta, and that distribution of the two major A beta species is similar to what is observed in A beta deposition in Alzheimer's disease (AD)-affected brain. This provides further evidence that chloroquine-induced myopathy in rats provides a suitable model to understand APP processing into A beta, and the role of APP in terms of the pathogenesis of AD.

Chloroquine, a potent lysosomotropic agent, induces myopathy in experimental animals similar to rimmed vacuole (RV) myopathy in humans. The abnormal accumulation of amyloid beta protein (A beta), which is the invariable pathological alterations in the brains affected by Alzheimer's disease (AD), has been demonstrated in denervated soleus muscle fibers in chloroquine-induced myopathy in rats. In AD affected brains, a variety of additional proteins are associated with the extracellular deposition of A beta, which leads to the intracellular accumulation of neurofibrillary tangles and finally to neuronal death. In this study, we demonstrate that amyloid-associated proteins, alpha 1-antichymotrypsin, apolipoprotein E, SP-40,40 and ubiquitin co-localize with A beta in vacuolated muscle fibers in chloroquine-induced myopathy. There are striking similarities in immunopathology between experimental RV myopathy and AD. Chloroquine-induced myopathy in rats provides a suitable model not only to obtain insight into the basic mechanisms underlying RV formation in muscle, but also to understand amyloid precursor protein processing into A beta, and the role of amyloid-associated proteins in terms of the pathogenesis of AD.

We have developed maximum likelihood (ML) methods for comparisons of nucleotide sequences from unlinked genomic regions. In the case of a single species, the ML method primarily estimates the effective population size (Ne) under both constant size and abrupt expansion conditions. In the case of two or three species, the ML method simultaneously estimates the species divergence time and the effective size of ancestral populations. This allows us to trace the evolutionary history of the human population over the past several million years (my). Available sequences at human autosomal loci indicate Ne = 10,000 in the Late Pleistocene, a figure concordant with the results obtained from mitochondrial DNA sequence and allele-frequency data analysis, and there is no indication of population expansion. The ML analysis of two species shows that humans diverged from chimpanzees 4.6 my ago and that the human and chimpanzee clade diverged from the gorilla 7.2 my ago. Furthermore, the effective population size of humans more than 4.6 my ago is nearly 10 times larger than Ne of modern humans. The effective population size in the human lineage does not seem to have remained constant over the past several million years. The ML model for three species predicts slightly different, but consistent results to those obtained by the two-species analysis.

We studied the differences in alterations of GABAAergic receptor function between pentobarbital (PB)-dependent female Lewis (LEW) and Wistar-Kyoto (WKY) rats. The 36Cl- influx induced by 10 microM GABA in the PB-dependent WKY was significantly lower than that in the control, while there was no significant 36Cl- influx change in both PB-dependent and control LEW. The additions of PB, flunitrazepam (FZ) and ethanol (EtOH) enhanced the GABA-dependent 36Cl- influx in control rats of both strains. However, the enhancements of 36Cl- influx by PB, FZ, EtOH were not recognized in PB-dependent WKY. On the other hand, the enhancement of GABA-dependent 36Cl- influx was observed only with the addition of PB in PB-dependent LEW. The additions of bicuculline (BIC) and picrotoxin (PIC) inhibited GABA-dependent 36Cl- influx in control rats of both strains. However, inhibition of 36Cl- influx by BIC and PIC was not recognized in the PB-dependent WKY. These results suggest that physical dependence on PB in WKY may cause greater functional alterations of the GABA/benzodiazepine receptor complex than those in LEW, and that these changes in this receptor complex may relate to the difference in the development of physical dependence on PB between the two strains.

Radon concentration in ground water increased for several months before the 1995 southern Hyogo Prefecture (Kobe) earthquake on 17 January 1995. From late October 1994, the beginning of the observation, to the end of December 1994, radon concentration increased about fourfold. On 8 January, 9 days before the earthquake, the radon concentration reached a peak of more than 10 times that at the beginning of the observation, before starting to decrease. These radon changes are likely to be precursory phenomena of the disastrous earthquake.

We analyzed the complete mitochondrial DNA (mtDNA) sequences of three humans (African, European, and Japanese), three African apes (common and pygmy chimpanzees, and gorilla), and one orangutan in an attempt to estimate most accurately the substitution rates and divergence times of hominoid mtDNAs. Nonsynonymous substitutions and substitutions in RNA genes have accumulated with an approximately clock-like regularity. From these substitutions and under the assumption that the orangutan and African apes diverged 13 million years ago, we obtained a divergence time for humans and chimpanzees of 4.9 million years. This divergence time permitted calibration of the synonymous substitution rate (3.89 x 10(-8)/site per year). To obtain the substitution rate in the displacement (D)-loop region, we compared the three human mtDNAs and measured the relative abundance of substitutions in the D-loop region and at synonymous sites. The estimated substitution rate in the D-loop region was 7.00 x 10(-8)/site per year. Using both synonymous and D-loop substitutions, we inferred the age of the last common ancestor of the human mtDNAs as 143,000 +/- 18,000 years. The shallow ancestry of human mtDNAs, together with the observation that the African sequence is the most diverged among humans, strongly supports the recent African origin of modern humans, Homo sapiens sapiens.

Deposition of amyloid beta (A beta) is one of the pathological hallmarks of brains affected with Alzheimer's disease (AD). The accumulation of A beta have been observed in human myopathies with rimmed vacuoles (RVs) which might involve lysosomal function. Chloroquine, a potent lysosomotropic agent, induces muscle pathology in experimental animals similar to myopathy with RV. In this study, we demonstrate, for the first time, immunohistochemical evidence that A beta and cathepsin D, a lysosomal enzyme, accumulate in vacuolated rat soleus muscle due to chloroquine-induced myopathy. These data indicate that lysosomes are important in the metabolism of amyloid precursor protein to generate A beta. This experimental system seems to be useful not only to study basic mechanisms underlying RV myopathy but also to understand processing of amyloid precursor protein to A beta in AD.

The principal neuropathological feature of Alzheimer's disease is extracellular deposition of approximately 4-kDa proteinous fragment, designated as beta-amyloid peptides (beta/A4 peptides) derived by proteolytic cleavage from amyloid precursor protein (APP), a large cell-surface receptor-like protein. There has been evidence that APP is proteolytically degraded in the secretory and endosomal/lysosomal pathways. The pathway in which APP is cleaved to generate beta/A4 peptides is still not identified. To clarify the intracellular processing of APP into the generation of beta/A4 peptides, we detected and characterized potentially amyloidogenic or non-amyloidogenic fragments using newly established monoclonal and polyclonal antibodies in the cultured cells with or without leupeptin, potent lysosomal protease inhibitor of lysosome. APP fragments of 50 and 20 kDa containing full-length beta/A4 peptides were identified in the cultured cells. Immunoblot analysis, biochemical study for specific marker enzyme activity of the fractions obtained from subcellular fractionation, sucrose density gradient centrifugation indicated that the 50-kDa APP fragment was produced in the compartment closely related to endosomal/lysosomal system. Our data suggest that the endosomal/lysosomal pathway is involved in the processing and generation of beta/A4 peptides.

Long persistence of allelic lineages, prevalence of nonsynonymous over synonymous substitutions in the peptide-binding region (PBR), and deviation from neutrality of the expected gene identity parameter F all indicate indirectly that balancing selection is operating at functional major histocompatibility complex (MHC) loci. Direct demonstrations of the existence of balancing selection at MHC loci are, however, either lacking or not fully convincing. To define the conditions under which balancing selection could be demonstrated, we estimated its intensity from the mean number of nonsynonymous substitutions, KB, at the PBR and the mutation rate mu. We compared the five available methods for estimating KB by computer simulation and chose the most reliable ones for estimation of selection intensity. For the human MHC, the selection coefficients of the HLA-A, -B, -C, -DRB1, -DQB1, -DQA1, and -DPB1 loci are 0.015, 0.042, 0.0026, 0.019, 0.0085, 0.0028, and 0.0007, respectively. This low selection intensity places severe restrictions on the possibility of measuring selection directly in vertebrate populations.

In contrast to well-studied "classical" class I genes of the major histocompatibility complex (MHC), the biology of nonclassical class I genes remains largely unexamined. The mouse TL genes constitute one of the best defined systems among nonclassical class I genes in the T region of the MHC. To elucidate the function and the evolution of TL genes and their relationship to classical class I genes, seven TL DNA sequences, including one from a Japanese wild mouse, were examined and compared with those of several mouse and human classical class I genes. The TL genes differ from either classical class I genes or pseudogenes in the extent and pattern of nucleotide substitutions. Natural selection appears to have operated so as to preserve the function of TL, which might have been acquired in an early stage of its evolution. In a putative peptide-binding region encoded by TL genes, the rate of nonsynonymous (amino acid replacing) substitution is considerably lower than that of synonymous substitution. This conservation is completely opposite that in classical class I genes, in which the peptide-binding region has evolved to diversify amino acid sequences so as to recognize a variety of antigens. Thus, it is suggested that the function of TL antigens is distinct from that of classical class I antigens and is related to the recognition of a relatively restricted repertoire of antigens and their presentation to T-cell receptors.

The case of a chronic alcoholic patient with Wernicke's encephalopathy accompanied by passing blindness is reported and the alcoholic amblyopia is discussed in this study. The patient was a 39 year-old male who had been a heavy drinker for 13 years, and was habitually inebriated for the last one year. Disturbance of consciousness ataxia of gait, nystagmus and blindness were manifested on admission. Decreased level of serum vitamin B1 was also recognized at admission. The symptoms diminished from about a month after admission except for horizontal nystagmus. Since the patient had racket-like scotoma in his central visual field, his blindness was thought to be alcoholic amblyopia. Although alcohol dependence is associated with many physical disabilities, there are few reports about Wernicke's encephalopathy with alcoholic amblyopia. This case demonstrates the importance of careful physical examination for understanding alcohol-related disabilities and alcohol dependence.

In Alzheimer's disease higher brain function disorders such as geographical disorientation, visual agnosia and constructional disability are frequently observed in addition to the progressive memory loss. Visual information processing was studied through newly developed technology, vision analyzer, since visuospatial functions play an important role in the pathophysiology underlying these neuropsychiatric symptoms and dementia itself. We found characteristic findings as to eye movements of focus indicating visual cognitive disorders. Language or language functions, however, are considered to be essentially involved in visuospatial functions. We examined eye movements of patients suffering from Alzheimer's disease (15 cases), MID (5 cases), Parkinson's disease (5 cases) and 10 control subjects during constructional behavior under various conditions in terms of visual information processing. 1. Alzheimer's disease (n = 15): All patients showed constructional disabilities when copying geometrical figures. 1) Three dimensional drawing was possible following verbal instructions in 7 out of 15 patients. 2) Three dimensional drawing was successful when the model figure to be copied was covered in 4 out of these 7 patients. 3) Three dimensional drawing was possible following verbal instruction in a dark room, although they were not so accurate but better than those when copied in 4 out of 7 patients. 4) The analysis of eye movements revealed that typical eye movements were confirmed during copying geometric figures. The distribution of the gazing points of focus, and the average eye movement velocity distribution were also distinctive. But these disorganized eye movements in description of graphic figures following verbal instruction became more similar to those of healthy controls when compared to those in the copying graphic figures. 2. MID (n = 5), Parkinson disease (n = 5), healthy controls (n = 10): 1) No subject showed constructional disability when copying a graphic figure. They were also capable to describe a graphic figure both in the dark and following verbal instruction. 2) No remarkable change was observed in the distribution of the eye movement, or in the average eye movement velocity on these subjects. 3. These results indicate that in an early stage of the patients with Alzheimer's disease, primary or fundamental disorders seem to lay in the verification process of visual information, which results in the difficulties in categorization process of the visual objects. The categorization process is involved with language function, which was preserved in a certain period at an early stage of the disease.(ABSTRACT TRUNCATED AT 400 WORDS)

In this study, we examined the quantity and quality of G proteins in membrane preparations from cortical regions (frontal, parietal, temporal and occipital cortex) in post-mortem brains obtained from subjects with chronic alcoholism and controls matched with respect to age and post-mortem delay (PMDT). Immunoblot analysis showed that the level of GsH alpha (52 kDa) was significantly decreased in temporal cortical membranes from alcoholics compared with controls, while no differences were observed in the amount of any G protein in frontal, parietal and occipital regions. Additionally, ethanol enhanced photoaffinity guanine nucleotide binding to both G alpha and Gi/o alpha in human cortical membranes. The percentage of increase in ethanol-stimulated photoaffinity GTP labeling of Gs alpha and Gi/o alpha was decreased in alcoholic patients in all cortical regions. These observations indicated that subsensitivities to ethanol-induced stimulation in G protein may contribute to impaired trans-signaling in cortical membranes of chronic alcoholics.

The present study examined the in vitro effects of antidepressants on functional photoaffinity labeling of GTP binding protein. Saturation binding studies were performed by incubating membranes with increasing concentrations of [32P]-AAGTP, followed by UV irradiation and SDS-PAGE. The specifically bound isotherms for each of the G proteins studied showed characteristics of a one site model. Scatchard analysis revealed increases in the Bmax and Kd of AAGTP binding for each of the G proteins (especially stimulatory G proteins) with the addition of antidepressants such as amitriptyline, clomipramine, desipramine and mianserin but not with monoamine oxidase inhibitor, antipsychotics and axiolytics. These results suggested that drugs having antidepressive properties may directly affect G protein, especially Gs protein.

This study investigated alterations in the receptor adenylyl cyclase system in the brain and platelets of alcoholics through the study of GTP binding (G) protein, which has a key role in the system, in the membranes of the post-mortem brain and platelets. Quantitative examination of G protein by immunoblotting showed that GsH alpha in the temporal cortex of the post-mortem alcoholic brain was significantly decreased with controls. Moreover, the extent of ethanol enhancement of functional photoaffinity GTP(azidoanilido GTP) labeling to Gs alpha and Gi alpha was decreased in all cortical regions (frontal, temporal, parietal, occipital cortex) from alcoholics. In the platelet membrane, a quantitative reduction in GsH alpha and GsL alpha levels as assessed by immunoblotting was seen in family history positive (FHP) alcoholics. A reduction in ethanol enhancement of AAGTP labeling to Gs alpha and Gi alpha was also observed in the FHP group. These alterations of G protein were not found in the platelets from family history negative (FHN) alcoholics. The dysfunctions of Gs protein occurring in platelet membranes of the FHP group are likely to parallel those that occur in the alcoholic brain. These results suggest that disturbances of G protein-mediated signal transduction may be involved in the pathophysiology of alcoholics and that platelet G protein may be used as a trait marker of alcoholics.

To find the residual effects of long term exposure to mercury vapour, neurobehavioural tests were given to ex-mercury miners about 18 years after the end of mercury exposure. Seventy six male ex-mercury miners who had been exposed to high concentrations of mercury vapour (over 1.0 mg/m3) and with a history of mercury intoxication were compared with controls matched for age (within 3 years), sex, and education. Although the extent of the workers' symptoms caused by mercury poisoning, termed erethismus merculialis, decreased considerably after the end of exposure, matched paired comparison showed that performances of motor coordination, simple reaction time, and short term memory had deteriorated significantly in the exposed group. Multiple linear regression analysis of exposure variables with neurological examination measures showed positive correlations between poorer neurological performance and variables related to mercury exposure. Thus the duration of exposure correlated with poorer performance of hand-eye coordination, tapping, and a colour card reading test. Job categories classified by exposure to mercury also had a significant negative correlation with these performances. The period of years after the end of exposure had a significant correlation with better performance of reaction time and digit span. On the other hand, the history of intoxication itself had no significant correlation with any of the current neurobehavioural performances. These results suggest that there are slight but persistent effects on neurobehavioural function, especially on motor coordination, among mercury miners even more than 10 years after the end of exposure.

The present study was designed to provide further information regarding the effect of ethanol on the function of inhibitory GTP-binding (Gi) protein. To eliminate the Gs function in the regulation of adenylyl cyclase, cerebral cortex membranes from Wistar or Fischer 344 rats were pretreated at pH 4.5 ("low pH"), whereupon Gpp(NH)p-dependent inhibition of forskolin-stimulated adenylyl cyclase was examined. In the membranes from Wistar rats, ethanol (100 or 250 mM) resulted in left-shifted Gpp(NH)p inhibition curves and reduced IC50 values for Gpp(NH)p in an ethanol dose-dependent manner. In contrast, ethanol exhibited no effect on the Gpp(NH)p-dependent inhibition of the enzyme or on IC50 values for Gpp(NH)p in the membranes from Fischer 344 rats. These results are consistent with the idea that ethanol, in vitro, enhances the Gi function in the cerebral cortex of Wistar rats, and that ethanol's effect on Gi protein in the cerebral cortex is different in Wistar and Fischer 344 rats.

Available genetic data reveals that the human population is more variable than the chimpanzee population at the protein level, whereas the opposite is the case at the DNA level. The lower level of silent polymorphism in the human population suggests that its long-term breeding size is smaller than the chimpanzee's. The neutral theory suggests that natural selection has been relaxed in the human population under the improved environment. The possibility that the relaxation began with the emergence of Homo sapiens is examined, because it is known that H. habilis underwent for the first time dramatic changes in brain size, way of life, and culture, and that the childhood of H. erectus was already twice as long as that of chimpanzee. The relaxation hypothesis predicts that, relative to chimpanzee, some 20% of deleterious mutations became harmless under the changed environment throughout the Pleistocene. More extensive study of genetic variation in non-human primates is necessary not only to confirm the hypothesis, but also to better understand the human genome itself.

A formula for the effective population size for the finite island model of subdivided populations is derived. The formula indicates that the effective size can be substantially greater than the actual number of individuals in the entire population when the migration rate among subpopulations is small. It is shown that the mean nucleotide diversity, coalescence time, and heterozygosity for genes sampled from the entire population can be predicted fairly well from the theory for randomly mating populations if the effective population size for the finite island model is used.

Qualitative and quantitative alterations of G proteins in membrane preparations from parietal and temporal cortex regions in post-mortem brains obtained from alcoholics and controls matched with respect to age and post-mortem delay were investigated by Western-blotting with polyclonal antibodies against specific G protein subunits and functional photoaffinity GTP binding. Quantitative immunoblotting showed that only Gs alpha (52 kDa species) in temporal cortex was significantly decreased (30%, P < 0.05) in alcoholics compared with controls. Moreover, ethanol-stimulated photoaffinity GTP labeling of Gs alpha and Gi/o alpha was decreased in alcoholics in both cortex regions. These results suggest that disturbances of G protein-mediated signal transduction may be involved in the pathophysiology of alcoholics.

Because the divergence of many allelic lineages at the major histocompatibility complex (MHC) loci predates species divergence, standard methods of calculating synonymous substitution rates are not applicable to this system. We used three alternative methods of rate estimation: one based on the minimum number of substitutions (Dm), another on the nucleotide difference (Dxy), and the third on the net nucleotide difference (Dn). We applied these methods to the protein-encoding sequences of primate MHC class I (A, B, and C) and class II (DRB1) genes. To determine the reliability of the different estimates, we carried out computer simulation. The distribution of the estimates based on Dxy or Dn is generally much broader than that based on Dm. More importantly, the Dm-based method nearly always has the highest probability of recovering true rates, provided that Dm is not smaller than 5. Because of its desirable statistical properties, we used the Dm-based method to estimate the rate of synonymous substitutions. The rate is 1.37 +/- 0.61 for A, 1.84 +/- 0.40 for B, 3.87 +/- 1.05 for C, and 1.18 +/- 0.36 for DRB1 loci, always per site per 10(9) years. Hence despite the extraordinary polymorphism, the mutation rate at the primate MHC loci is no higher than that of other loci.

In order to determine if there are any residual effects of long-term exposure to mercury vapor, neurobehavioral tests were given to ex-mercury miners about 18 years after the cessation of mercury exposure. Seventy-six male ex-mercury miners who had been exposed to relatively high concentrations of mercury vapor (over 1.0 mg/m3) and with a past history of mercury intoxication were compared to age (+/- 3 years)-, sex-, and years of education-matched controls. Although the extent of the workers' symptoms caused by mercury poisoning, termed erethismus merculialis, markedly decreased after the cessation of exposure, the prevalence of neurological symptoms (such as hand tremors, headaches, and slurred speech) and symptoms of senility (such as low-back pain, loss of sexual desire) in the ex-miners was significantly higher than those in the controls. Matched-pair analysis showed that performances of motor coordination, Simple reaction time, and Short-term memory in the ex-miners were significantly deteriorated compared to those of controls. There are slight but persistent effects on neurobehavioral function, especially on motor coordination function, among mercury miners more than 10 years after the cessation of exposure.

Focusing on the synonymous substitution rate, we carried out detailed sequence analyses of hominoid mitochondrial (mt) DNAs of ca. 5-kb length. Owing to the outnumbered transitions and strong biases in the base compositions, synonymous substitutions in mtDNA reach rapidly a rather low saturation level. The extent of the compositional biases differs from gene to gene. Such changes in base compositions, even if small, can bring about considerable variation in observed synonymous differences and may result in the region-dependent estimate of the synonymous substitution rate. We demonstrate that such a region dependency is due to a failure to take proper account of heterogeneous compositional biases from gene to gene but that the actual synonymous substitution rate is rather uniform. The synonymous substitution rate thus estimated is 2.37 +/- 0.11 x 10(-8) per site per year and comparable to the overall rate for the noncoding region. On the other hand, the rate of nonsynonymous substitutions differs considerably from gene to gene, as expected under the neutral theory of molecular evolution. The lowest rate is 0.8 x 10(-9) per site per year for COI and the highest rate is 4.5 x 10(-9) for ATPase 8, the degree of functional constraints (measured by the ratio of the nonsynonymous to the synonymous substitution rate) being 0.03 and 0.19, respectively. Transfer RNA (tRNA) genes also show variability in the base contents and thus in the nucleotide differences. The average rate for 11 tRNAs contained in the 5-kb region is 3.9 x 10(-9) per site per year. The nucleotide substitutions in the genome suggest that the transition rate is about 17 times faster than the transversion rate.

The effect of ethanol "in vitro" on GTP-binding protein in postmortem human brain cortex membranes was analyzed using by photoaffinity hydrolysis resistant GTP analog (azidoanilido GTP, AAGTP). AAGTP identified stimulatory GTP binding protein [Gs alpha (42 KDa)] and inhibitory GTP binding protein [Gi alpha (40 KDa)] in human brain cortex membranes. Ethanol augmented the amount of AAGTP binding to both Gs alpha and Gi alpha in human temporal and parietal cortex membranes. These results show that ethanol "in vitro" elevates not only Gs functions but also Gi functions in postmortem human brain cortex.

The neural activities of the parietal association cortex were studied in humans through the use of a 37-channel SQUID magnetometer system. The magnetic field responses were recorded in the parietal association cortex following visual stimulation with LED light. Main responses peaking at about 120, 170 and 220 msec after LED onset were observed. The estimated current dipole sources of the magnetic field responses at latencies of 160-190 and 210-270 msec were revealed to be located in the intraparietal sulcus. A change in the magnetic field responses with the eye position was found in the amplitude.

Brain adenylate cyclase (AC) activity in the alcohol-preferring AA (Alko Alcohol) and alcohol-avoiding ANA (Alko, Non-Alcohol) rats was examined. Both basal and Gpp(NH) p-stimulated AC activities were higher in the cerebral cortex of the ANA rats than in the AA rats. Isoproterenol-stimulated AC activity tended to increase in the cerebral cortex of the ANA rats compared to the AA rats. Basal AC activity in the striatum of the AA rats was higher than that in the ANA rats, however, striatal Gpp(NH)p-stimulated AC activity was not different between the two rats lines. In the mesolimbic and cerebellum, there was no difference in AC activity between the rat lines. These results suggest that the noradrenergic function in the cerebral cortex has an important role in the regulation of alcohol intake.