Molecular cloning and expression of the rat homologue of presenilin-1

The rat homologue of the presenilin-1 (PS-1) gene, which is responsible for early-onset familial Alzheimer's disease linked to chromosome 14, was cloned and sequenced. The predicted amino acid sequence showed quite high homology among rat, mouse, and human PS-1. Especially, the amino acid sequences of the putative transmembrane domains were highly conserved among the three species. The expression ĺevel of the PS-1 gene increased during brain development and the number of transcripts of the PS-1 gene changed during brain development. We found one transcript of the PS-1 gene in embryonic day 12 (E12)-E15 rat brain and two transcripts in E18-adult rat brain. Therefore, PS-1 may play a role in neurogenesis.

Assessment of posterior aortic wall motion using echocardiogram in patients with atrial fibrillation

BACKGROUND AND HYPOTHESIS

Noninvasive evaluation of left ventricular (LV) diastolic function was performed on 12 patients with atrial fibrillation (AF) using posterior aortic wall echocardiogram and a parameter for determining the optimal heart rate in patients with chronic atrial fibrillation was considered.

METHODS

Subjects were divided into two groups; one with no underlying cardiac disease (AF only group; n = 7) and the other with dilated cardiomyopathy (DCM group; n = 5). Left atrial emptying index (LAEI) obtained from the posterior aortic wall echocardiogram was used as the parameter of LV diastolic function, and R-R interval-LAEI relation and minimum R-R interval showing LAEI = 1.0 were investigated and compared between the two groups.

RESULTS

There was a good correlation between R-R interval and LAEI until LAEI of 1.0 was obtained in all patients. Slope of the regression line was significantly steeper in the AF only group than in the DCM group, and minimum R-R interval showing LAEI = 1.0 was significantly shorter in the AF only group.

CONCLUSION

Assessment of R-R interval-LAEI relation was useful for the noninvasive evaluation of LV diastolic function, and this parameter could be used for clinical application to determine the optimal heart rate in atrial fibrillation.

Sensory control mechanisms of the uropod equilibrium reflex during walking in the crayfish Procambarus clarkii

The temporal characteristics of statocyst and leg proprioceptive inputs to the uropod motor system were investigated in crayfish using behavioural and electromyographic analyses to elucidate their functional roles in the control of the uropod steering response under natural conditions. When the animal, which was suspended in the air without a footboard, was actively extending its abdomen, prolonged stimulation of the statocysts by body rolling elicited a maintained asymmetrical configuration of the bilateral uropods. Prolonged stimulation of the walking legs by footboard tilting with the animal body held in the upright position elicited a transient uropod response. When the treadmill was tilted while the animal was walking on it in the upright position, the uropods showed the same transient response. However, when the animal body was rolled, together with the treadmill, while the animal was walking on it, the uropods showed a transient response which was reversed in direction compared with that observed during body rolling without a footboard. This transient response was abolished by the removal of the statoliths. The results show that the statocysts and leg proprioceptors exert sustained and transient control effects, respectively, on the uropod motor system during walking. It is also suggested that the uropod response to body rolling during walking is controlled primarily by leg proprioceptor signals which result from statocyst-induced changes in the leg position.

Association between alcoholism and the dopamine D4 receptor gene

A point mutation in the aldehyde dehydrogenase 2 gene (ALDH2(2) allele) is considered to be a genetic deterrent for alcoholism; however, 80 of 655 Japanese alcoholics had the mutant allele. Genotype factors that might increase susceptibility by overriding the deterrent showed a higher frequency of a five repeat allele of the dopamine D4 receptor 48 bp repeat polymorphism in alcoholics with ALDH2(2) than in 100 other alcoholics and 144 controls. Alcoholics with the five repeat allele also abused other drugs more often. These data suggest the involvement of the dopamine system in the development of alcoholism and other addictive behaviour.

A 13-Mer peptide of a brain injury-derived protein supports neuronal survival and rescues neurons from injury caused by glutamate

Neuronal survival is mediated by several kinds of proteins. Among these, neurotrophic factors play important roles in the nervous system by supporting neuronal activity and survival. It has been suggested recently that certain factors promote neuronal survival in the case of brain injury. To examine this possibility, we purified a novel neurotrophic factor from Gelfoam that was implanted at the site of injury caused in neonatal rats. During amino acid sequence analysis, we found that a fragmental peptide of this neurotrophic protein consisting of 13 amino acids showed neurotrophic activity. This 13-mer peptide promoted survival of septal cholinergic and mesencephalic dopaminergic neurons in culture and rescued hippocampal neurons from injury caused by glutamate in culture. This peptide rescued neurons from cell death caused by glutamate, even when added 4.5 h after glutamate exposure.

[Effects of weight training on muscle strength and exercise capacity in patients after myocardial infarction]

The effect of combined aerobic and weight training on indexes of muscle strength and exercise capacity was investigated in 59 patients after myocardial infarction. Subjects were randomly assigned into three groups: group I performing combined aerobic and weight training (n = 22), group II performing ordinary aerobic training alone (n = 19) and group III not performing physical training (n = 18). Before and after the training, isokinetic knee extension strength was measured and cardiopulmonary exercise testing was performed. Physical training was prescribed for 8 weeks. Weight training of knee extensors was performed at 60% of 1 repetition maximum and aerobic training was prescribed at the heart rate of anaerobic threshold (AT) level. After 8 weeks, the increase of isokinetic knee extension strength was significantly greater in group I (26 +/- 14%) than group II (6 +/- 8%) and III (4 +/- 8%). Increases in peak VO2, exercise time, AT and peak O2 pulse were greater in groups I and II than group III. Furthermore, increase of exercise time was greater in group I (25 +/- 14%) than group II (16 +/- 9%). The rating of perceived exertion in submaximal exercise decreased significantly only for group I. In patients with myocardial infarction, combined aerobic and weight training is a more effective method for increasing muscle strength and exercise capacity than only ordinary aerobic training.

Responses of plasma adrenocortical steroids to low dose ACTH in normal subjects

OBJECTIVE

The standard ACTH test in clinical use employs a pharmacological dose of ACTH which assesses the maximum secretory capacity of the adrenal cortex. We have investigated the responses of plasma adrenocortical steroids including cortisol, aldosterone and dehydroepiandrosterone (DHEA) to physiological doses of ACTH (ACTH 1-24, tetracosactide, Cortrosyn) and determined the minimal dose which induces a response equivalent to that induced by a pharmacological dose of ACTH.

DESIGN

Rapid ACTH tests at various physiological (0-1, 0.5, 1 and 5 micrograms) and standard pharmacological (250 micrograms) intravenous doses.

SUBJECTS

Seven healthy normal volunteers.

MEASUREMENTS

Plasma cortisol, aldosterone and DHEA were measured. Peak value and the increment from basal value were used as indices of responses.

RESULTS

Each steroid responded to physiological doses of ACTH in a dose dependent manner. The minimum dose inducing an equivalent response to 250 micrograms ACTH was 0.5 micrograms for peak and incremental values in cortisol and DHEA, while that for aldosterone was 0.1 microgram. The time to peak for each steroid was delayed as the dose increased. Plasma aldosterone and DHEA peaked significantly earlier than plasma cortisol in 1-5 micrograms and 0.5-5-micrograms ACTH tests, respectively.

CONCLUSIONS

These results suggest that the sensitivity of secretion to physiological doses of ACTH in descending order is aldosterone > DHEA = cortisol. When peak and incremental values are used, sufficient doses of ACTH are 0.1 microgram for plasma aldosterone and 0.5 microgram for plasma cortisol and DHEA in the rapid ACTH test.

[Changes in plasma tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) by the interferon treatment for chronic hepatitis C]

To determine the effects of interferon (IFN) treatment for chronic hepatitis C on vascular endothelium, we measured the concentrations of tissue plasminogen activator (t-PA) and its inhibitor (PAI-1) in the plasma from patients before and after IFN treatment for 14 consecutive days. The plasma t-PA and PAI-1 levels were measured before and after treatment. The plasma t-PA level was significantly increased after IFN treatment (p < 0.01) but no significant difference in plasma PAI-1 level was observed before and after treatment. The ratio of t-PA/PAI-1 was significantly increased after IFN treatment (p < 0.05). These changes may be caused by the effect of IFN on endothelium, leading to an activation of the endothelium derived fibrinolysis factors. Increase in plasma t-PA concentration may induce hyperfibrinolysis which may be one of the causes of suborbital hemorrhage. Further study on the fibrinolysis pathway in the blood is necessary to elucidate the mechanisms of the many side effects observed during IFN treatment.

Alcohol and aldehyde dehydrogenase polymorphisms and the risk for alcoholism

OBJECTIVE

The authors studied a large number of Japanese alcoholic patients and comparison subjects to establish the genotype frequencies of alcohol dehydrogenase-2 (ADH2) and mitochondrial aldehyde dehydrogenase (ALDH2) and to quantify the relative risk for alcoholism from the results.

METHOD

The subjects were 655 alcoholic patients and 461 comparison subjects. ADH2 and ALDH2 were genotyped by the combination of polymerase chain reaction and hybridization methods.

RESULTS

Active ALDH2 and usual ADH2 were significantly more frequent in the alcoholic patients. Inactive ALDH2 was not always associated with a low risk of alcoholism, and active ALDH2 was not always associated with high risk. In individuals with heterozygous inactive ALDH2 and usual ADH2, the odds ratio for alcoholism was high.

CONCLUSIONS

The risk for alcoholism in Japanese has been accurately estimated on the basis of the genotype frequencies of ADH2 and ALDH2. Many Japanese may be protected from alcoholism by inactive ALDH2 and by higher frequencies of atypical ADH2.

[Effects of 5-fluorouracil in shrinking residual gastric cancer: a case report]

The patient was a 79-year-old man who underwent extensive gastrectomy and Billroth-II reconstruction for gastric ulcer in 1974. He complained of heartburn in November, 1992, and endoscopy for the residual stomach revealed IIb + IIa-like lesion mainly in the posterior wall of the anastomosed site, which was diagnosed as well differentiated adenocarcinoma. As the patient refused to be operated, 150 mg/day of 5-FU was administered. For 4 months before he decided to undergo operation, 12.9 g of 5-FU was administered in total. After rehospitalization, endoscopy of the residual stomach showed shrinkage of the lesion, and biopsy revealed no malignant findings. The pathological examination after total resection of the residual stomach showed atypism, but no evidence to support malignancy. He has continued to be well without sign of recurrence for 1 year since the operation. The administration of 5-FU is widely used as preoperative adjuvant chemotherapy. This case it is rare for 5-FU to cause the disappearance or falling off of malignant cells.

A case of unique communication between blind-ending ectopic ureter and ipsilateral hemi-hematocolpometra in uterus didelphys

Uterus didelphys with double vagina and hemi-vaginal atresia is a rare syndrome of congenital anomalies. A 17-year-old girl had a right blind-ending ectopic ureter, the proximal end of which communicated with the ipsilateral uterine cervix of uterus didelphys. The patient presented with vaginal urinary incontinence after incision of the vaginal wall for right hemi-hematocolpometra. Following various examinations, the ipsilateral kidney was found to be absent. The ectopic ureter and communicating duct were resected, and the fistula was closed. The genesis of malformation of the female genitalia and urinary tract resulting in such a unique communication is discussed. The importance of preoperative meticulous examinations, including cysto-genitography, pelvic magnetic resonance imaging and panendoscopy with the patient under anesthesia, is emphasized.

Association of structural polymorphism of the dopamine D2 receptor gene and alcoholism

To examine the possible association between three recently identified structural polymorphisms of the dopamine D2 receptor (DRD2) gene and alcoholism, we compared allele frequencies of these polymorphisms in 280 Japanese alcoholics and 289 normal controls. The results revealed that only one of three variants identified in white individuals existed in the alcoholic and control Japanese. The frequency of the Cys311 variant allele was significantly higher in alcoholics (.063) than in controls (.029). All of the subjects with the variant allele were heterozygous Ser311/Cys311. Patients with Cys311 allele had less severe symptoms of alcoholism than did those with homozygous Ser311, especially symptoms related to loss of control over drinking. The coprevalence of other psychiatric disorders including schizophrenia did not differ between the two patient groups. These results suggest that the D2/Cys311 variant is associated with some type of alcoholism in Japanese.

[Serum levels of HCV-RNA determined by branched DNA (bDNA) probe assay in chronic hepatitis C: method and clinical significance on interferon (IFN) therapy]

Recently serum levels of HCV RNA (s-HCV RNA) in chronic hepatitis C has been regarded as one of an important indicator for the activity of disease and outcome of IFN therapy. Quantitative analysis by competitive RT-PCR, however, requires special skills and is too expensive for clinical use. We attempted to determine serial sample of s-HCV RNA and genotypes in 117 cases treated with IFN using bDNA probe assay which has lately been developed by Chiron corporation. Cases with complete response to IFN therapy showed 62% (49/79) in lower than 10(6) levels, 27% (8/30) in 10(6)-10(7) and only 5% (2/41) in higher than 10(7). Genotype III, IV had higher response than type II on the same level of s-HCV RNA. These data indicates that determination of s-HCV levels by bDNA assay may be useful for prediction of the outcome of IFN therapy and making adequate schedule of the therapy in each cases.

[Histological evaluation of the liver and response to interferon in chronic hepatitis C]

Liver histology was compared in patients with chronic hepatitis C to clarify the difference between responders and non-responders to interferon therapy. We have treated 50 patients with chronic hepatitis C by natural IFN-alpha 6.0 MU/day for 2 weeks, daily, followed by intermittent therapy for 3-6 months. The overall effect of IFN was a complete response (CR) in 16 (32%), transient response (TR) in 14 (28%), and no response (NR) in 20 (40%). According to the pre-treatment liver histology, CR had a lower total numerical scores than TR and NR. Histological difference between CR and TR appeared to be the degree of portal inflammation and piecemeal necrosis, though NR showed an increase in portal fibrosis compared of CR and also TR. Response to IFN may depend on the degree of liver fibrosis rather than other histological factors. To assess the degree of liver fibrosis is thought to be important for the prediction of the efficacy of IFN therapy.

[Lack of association between alcoholism and alleles in the delta-aminolevulinic acid dehydratase (ALAD) gene]

delta-Aminolevulinic acid dehydratase (ALAD) is the second enzyme in the heme biosynthetic pathway and catalyzes two molecules of delta-aminolevulinate (ALA), which is a potent agonist for GABA autoreceptors. ALAD has two common alleles and thus consists of three distinct isozymes, designated 1-1, 1-2, and 2-2. It has been shown recently that ALAD1 allele is associated with alcoholic liver injury. This association was ascribed to possible differences among isozymes in sensitivity to oxidized glutathione (GSSG), and this sensitivity is increased in erythrocytes of alcoholic patients. In the present study we measured erythrocyte ALAD activity from subjects with different ALAD genotype and found ALAD-1 is most sensitive to GSSG. We then investigated allele frequencies of ALAD in alcoholics (n = 126) and healthy controls (n = 115). For the control group, the frequencies were 0.94 (ALAD1) and 0.06 (ALAD2) and for the overall alcoholic group, 0.91 (ALAD1) and 0.09 (ALAD2). There were no significant differences in allele frequencies at the ALAD locus between the two groups. Subtyping the alcoholics according to the presence or absence of delirium tremens, hallucinosis, withdrawal seizure or liver cirrhosis failed to show statistically significant differences in the allele frequencies. We conclude that our data do not support the evidence of an allelic association between the ALAD1 and alcoholism.

[A study on preventive measures for redrinking in alcoholics]

We conducted a questionnaire survey on reasons or situations that lead alcoholics to start drinking alcohol, and measures to overcome the craving for alcohol. The subjects were 187 alcoholics (mean age; 53.9 +/- 9.9) who were outpatients of Kurihama National Hospital or the members of "Danshu-kai" (Japan Sobriety Association). Their mean abstinent period at the time of this survey was 43.6 months. To examine the relationship between various factors such as demographic backgrounds, reasons to start drinking, and measures to overcome craving and the length of abstinent periods, the subjects were divided into two groups in terms of abstinent periods; long-term group (24 months or more of abstinence, 88 cases) and short-term group (less than 24 months of abstinence, 99 cases). As reasons for taking the last drink, "psychological problems" showed the highest percentage (20.3%), followed by starting drink without any reason (17.7%). Measures used most frequently to overcome craving were "thinking about their own lives" (34.8%), "contacting self-help groups" (22.5%), and "thinking about self-help groups" (20.9%). Interestingly, non-alcoholic beverages were often used to overcome craving; coffee or tea and non-alcoholic soda were most frequently used in the long-term group, and coffee or tea and milk in the short-term group. The results of this study suggest that there is no particular situation or reason of significance that specifically induces the craving for alcohol in alcoholics. They took various measures to overcome craving. From the viewpoint of managing craving, this study reconfirmed the significant importance of self-help groups for sustaining long-term abstinence.