Procedural memory in patients with mild Alzheimer's disease

Motor, perceptual, and cognitive skill learning abilities of mild Alzheimer's disease (AD) patients were compared to sex-, age-, and education-matched controls. We excluded patients who were unable to perform each skill learning task with a predetermined criterion. In those who completed the task, skill learning was as good as in normal controls. On the cognitive and perceptual skill learnings, some of the AD patients, whose cognitive but not declarative memory functions were more severely impaired than in those who completed the whole session, failed to complete the task, while all patients could complete the motor task. These results support that view that patients with mild AD can acquire motor, perceptual, and cognitive skills and that the neural system subserving procedural skill is not related to the neural systems for declarative memory.

The disturbances of object vision and spatial vision in Alzheimer's disease

Thirty-one patients with mild-to-moderate Alzheimer's disease (AD) underwent a test battery of complex visual tasks. We assessed the scores using a principal-factor analysis to elucidate the underlying deficits. There were three independent factors: The first factor included the tasks of identifying and comparing forms of visual stimuli. The second factor consisted of digit span and digit symbol tasks, and the third factor consisted of a specified visual counting task. We considered these three factors as representing the dysfunctions of object recognition, general attention and spatial recognition, respectively. These results underline the disturbances of the two visual systems, object vision and spatial vision, in early-AD patients.

Postoperative tetany in patients with Graves' disease: a risk factor analysis

OBJECTIVE

There is little information regarding the clinical risk factors for postoperative tetany in patients with Graves' disease. We analysed the risk factors responsible for postoperative tetany by univariate and multivariate analysis in thyroidectomized patients with Graves' disease, and we discuss the mechanisms of hypocalcaemia and tetany after surgery.

PATIENTS

The subjects were 1742 consecutive patients with Graves' disease who underwent subtotal thyroidectomy between 1992 and 1994.

RESULTS

Univariate analysis of 15 possible risk factors demonstrated that 10 were significant: sex, required operation time, blood loss, preoperative serum calcium level, estimated weight of thyroid remnant, size of goitre, amount of excised thyroid tissue, serum alkaline phosphatase concentration, age at operation and TSH-binding inhibitory immunoglobin (TBII). In multivariate analysis in female patients, the risk factors were: preoperative lower serum calcium level, younger age, higher serum alkaline phosphatase concentration, larger size of goitre and higher value of TBII, in order of decreasing probability of significance.

CONCLUSION

These results, combined with previous observations in which a significant decline in serum parathyroid hormone level was found in patients with Graves' disease who suffered postoperative tetany, suggests that postoperative tetany may occur during the period of bone restoration due to antithyroid drug therapy and be due to continuation of a calcium flux bone concomitant with transient hypoparathyroidism induced by surgery. Calcium supplements during preoperative period and/or after surgery may be appropriate for patients who are anticipated to develop postoperative tetany based on these risk factors.

[Study of workload and cervicobrachial disorder among sign language interpreters]

We conducted a nationwide questionnaire study on the workload and health conditions of professional sign language interpreters to investigate the relationship between occupational cervicobrachial disorders (OCD) and the sign language workload. The number of valid respondents was 542 (92.3%), 85.8% of them females. They were employed by the national or local governments or organizations for the disabled. The complaint rates of subjective symptoms involving the neck, shoulders, arms, fingers, eyes and ears, being equal or higher than the rates reported for cashiers, telephone operators and nursery school teachers when OCD occurred frequently. As the workload of sign language increased, the number of complaints of symptoms in the cervicobrachial region, which also includes fingers, increased as well. Occupational safety and health management for preventing OCD should be carried out immediately for sign language interpreters.

C-type natriuretic peptide suppresses arginine-vasopressin secretion from dissociated magnocellular neurons in newborn rat supraoptic nucleus

Central administration of C-type natriuretic peptide (CNP) affects various neuroendocrine systems. In the present study, we examined whether CNP acts directly on arginine-vasopressin (AVP) secretion from rat supraoptic nucleus (SON) neurons, using acute dissociated cell preparations. CNP inhibited the basal secretion of AVP in a dose-dependent manner (10(-11)-10(-6) M). A- type natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) also suppressed the basal secretion of AVP, however, the effects were two-orders of magnitude less potent than CNP. CNP also suppressed All-induced AVP secretion, however, the inhibitory effect of CNP was less than that of ANP or BNP. These findings suggest that CNP inhibits the basal secretion of AVP through natriuretic peptide receptor (NPR)-B and has a role in the body water and electrolyte homeostasis in the central nervous system.

Increase of urocortin-like immunoreactivity in the rat supraoptic nucleus after dehydration but not food deprivation

The effects of dehydration and food deprivation on urocortin-like immunoreactivity (Ucn-IR) in the rat supraoptic nucleus (SON) and the paraventricular nucleus (PVN) were examined by immunohistochemistry. Water deprivation for 48 h caused a significant increase in the number of Ucn-IR neurons in the SON, compared with control. Ucn-IR fibers and varicosities in the SON and the internal zone of the median eminence (ME) were increased, but a few and faint Ucn-IR neurons and fibers were observed in the PVN. On the other hand, food deprivation for 48 h caused a significant decrease in the number of Ucn-IR neurons in the SON, compared with control. Ucn-IR fibers and varicosities in the SON and the ME were fewer than those in controls. Ucn-IR neurons and fibers in the PVN were not detected after food deprivation. These results suggest that Ucn in the SON may be involved in the central regulation of water balance and nutrient homeostasis.

Increase of urocortin-like immunoreactivity in the rat hypothalamo-neurohypophysial system after salt loading and hypophysectomy

The effect of chronic salt loading on urocortin-like immunoreactivity (Ucn-IR) was investigated in the rat hypothalamo-neurohypophysial system. In control rats a few Ucn-IR neurons were observed scattered throughout the supraoptic nucleus (SON) and few in the paraventricular nucleus (PVN). A small number of Ucn-IR fibers were observed scattered in the median eminence (ME) and the posterior pituitary. However, after 5 days of chronic administration of 2% saline, a marked increase in the number of Ucn-IR perikarya and fibers was observed in the PVN and the SON. Additionally, Ucn-IR varicosities and fibers were found in the internal zone of the ME and in the posterior pituitary. To confirm the findings and examine the possible involvement of anterior pituitary function in synthesis of Ucn, surgical hypophysectomized rats were used. Five days after hypophysectomy, a marked increase in Ucn-IR was observed in the PVN, the SON, and both the internal and the external zone of the ME. These results suggest that Ucn in the hypothalamo-neurohypophysial system may be involved in the regulation of salt balance, and possibly in the stimulation of ACTH release from the anterior pituitary.

Parathyroid hormone-related peptide-(1-34) [PTHrP-(1-34)] induces vasopressin release from the rat supraoptic nucleus in vitro through a novel receptor distinct from a type I or type II PTH/PTHrP receptor

PTH and PTH-related peptide (PTHrP) bind to a type I PTH/PTHrP receptor expressed in bone and kidney or a type II receptor in nonclassical target tissue with equal affinity and similar bioactivities. PTHrP is abundant in the central nervous system, but its physiological role remains unknown. Herein, we examined the role of PTHrP-(1-34) on arginine vasopressin (AVP) release from the rat supraoptic nucleus (SON). Application of PTHrP-(1-34) to SON slices caused an increase in AVP release in a concentration-dependent manner. Neither PTHrP-(7-34) nor PTH-(1-34) had any effect on AVP release from the SON. PTHrP-(1-34)-induced AVP release was antagonized by a large excess of PTHrP-(7-34) and by H89, an inhibitor of cAMP-dependent protein kinase (A kinase), but not by PTH-(1-34) or PTH-(13-34). PTHrP-(1-34), but not PTH-(1-34), also dose-dependently increased the levels of cAMP in the SON. 125I-Labeled PTHrP-(1-34) bound specifically to crude membranes isolated from the SON. Scatchard analysis showed a single class of binding sites for PTHrP-(1-34) with a Kd of 36.4 nM and a maximum binding capacity of 3.94 pmol/mg protein. No specific binding for 125I-labeled PTH-(1-34) was noted. The binding of 125I-labeled PTHrP-(1-34) was displaced by unlabeled PTHrP-(1-34) and unlabeled PTHrP-(7-34), but not by unlabeled PTH-(1-34). These findings suggest that PTHrP-(1-34), but not PTH-(1-34), causes the release of AVP from the SON through a novel receptor distinct from type I or II PTH/PTHrP receptors.

Mice lacking mitochondrial uncoupling protein are cold-sensitive but not obese

The mitochondrial uncoupling protein (UCP) in the mitochondrial inner membrane of mammalian brown adipose tissue generates heat by uncoupling oxidative phosphorylation. This process protects against cold and regulates energy balance. Manipulation of thermogenesis could be an effective strategy against obesity. Here we determine the role of UCP in the regulation of body mass by targeted inactivation of the gene encoding it. We find that UCP-deficient mice consume less oxygen after treatment with a beta3-adrenergic-receptor agonist and that they are sensitive to cold, indicating that their thermoregulation is defective. However, this deficiency caused neither hyperphagia nor obesity in mice fed on either a standard or a high-fat diet. We propose that the loss of UCP may be compensated by UCP2, a newly discovered homologue of UCP; this gene is ubiquitously expressed and is induced in the brown fat of UCP-deficient mice.

Examining the diagnostic utility of the Fuld cholinergic deficit profile on the Japanese WAIS-R

The diagnostic utility of the Fuld cholinergic deficit profile (Fuld, 1984) to dementia of the Alzheimer type (DAT) was evaluated on the Japanese version of the WAIS-R. Profiles were calculated for groups of subjects with DAT(n = 236), vascular dementia (n = 29), frontotemporal dementia (n = 22), and hydrocephalic dementia (n = 10). The frequency of positive profile occurrence for the subject groups was as follows: 23/236 for DAT (9.7%), 2/29 (6.9%) for vascular dementia, 2/22 (9.1%) for frontotemporal dementia, and 2/10 (20%) for hydrocephalic dementia. No significant difference in the frequency of positive profile occurrence was revealed across four types of dementia. We conclude from these findings that the Fuld profile lacks the diagnostic utility on the Japanese WAIS-R.

Cholestyramine loading test to assess hepatic reserve for bile acid synthesis in patients with chronic liver diseases

BACKGROUND & AIMS

Serum 7alpha-hydroxycholesterol level reflects hepatic bile acid synthesis in humans. The aim of this study was to examine the maximal bile acid synthesis in patients with chronic liver diseases.

METHODS

Cholestyramine (12 g/day) was administered for 3 days to patients with compensated liver cirrhosis (n = 7), patients with chronic hepatitis (n = 10), and control subjects (n = 9), and serum total 7alpha-hydroxycholesterol level was measured by gas-liquid chromatography-mass spectrometry.

RESULTS

A preliminary study showed that cholestyramine increased the serum value to the maximum by the third day. Before cholestyramine treatment, there were no significant differences in serum 7alpha-hydroxycholesterol levels among the groups. Three days of cholestyramine treatment increased the serum levels 5.71 +/- 2.90-fold in the controls, 3.25 +/- 0.85-fold in patients with chronic hepatitis, and 1.70 +/- 0.78-fold in cirrhotic patients. Cirrhotic patients had significantly lower serum 7alpha-hydroxycholesterol levels after the treatment compared with other groups. Serum 7alpha-hydroxycholesterol levels stimulated by cholestyramine significantly correlated with serum albumin levels and indocyanine green retention rate.

CONCLUSIONS

Three days of cholestyramine loading increased the bile acid synthesis to its maximal level. The cholestyramine test showed that patients with chronic hepatitis had enough hepatic reserve for bile acid synthesis; however, patients with compensated liver cirrhosis had significantly decreased capacity.

Effect of smoking on the prevalence of albuminuria in Japanese men with non-insulin-dependent diabetes mellitus

Smoking is a risk factor for diabetic nephropathy in patients with IDDM and potentially those with NIDDM. We investigated the relationship between renal involvement and cigarette smoking in 148 men with NIDDM. The presence of renal involvement was assessed by determining the overnight urinary albumin/creatinine ratio (mg/g, ACR). The patients were divided into three groups, normo-, micro-, and macroalbuminuria, based on the ACR (< 30, 30-300, and 300 < or = mg/g, respectively). The incidence of micro-/macroalbuminuria in 81 smokers was significantly higher than that in 21 ex-smokers (stopped smoking at least 10 years prior to the study) or 40 non-smokers (53.1, 33.3, and 20.0%, respectively). The prevalence of smoking in the groups of patients with normo-, micro-, and macroalbuminuria were 45, 73, and 76%, respectively. The relative risk (odds ratio) for the prevalence of micro-/macroalbuminuria associated with smoking was 4.5 (95% CI, 1.9-11.6, P < 0.001) in smokers and was 2.0 (not significant) in ex-smokers. Our results indicate that stricter counselling about the importance of quitting smoking will be necessary in patients with NIDDM to protect against the development of diabetic nephropathy.

Strain differences in sensitivity to the promoting effect of sodium L-ascorbate in a two-stage rat urinary bladder carcinogenesis model

Rat strain differences in sensitivity to the promoting effect of sodium L-ascorbate (SA) on the development of urinary bladder tumors were investigated. In experiment 1, WS/Shi (WS), ODS/Shiod/od (ODS), and LEW/Crj (LEW) rats were initiated with 0.05% N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) in their drinking water and subsequently given basal Oriental MF diet (M) with or without a 5% SA supplement. In LEW rats the SA treatment increased the induction of neoplastic lesions in the urinary bladder, whereas WS and ODS animals proved unresponsive to its promoting effects. In experiment 2, WS and F344 rats were maintained on two kinds of commercial basal diets, M and CLEA CA-1 (C), during administration of SA, since dietary factors can influence promoting effects. Feeding M during the promotion period in F344 rats yielded significantly more neoplastic lesions than feeding C, but in WS rats no such dietary influence was apparent. In experiment 3, strain differences in biosynthesis of alpha-2u-globulin (alpha 1a-g) were assessed because both alpha 2a-g in the urine and administration of sodium salts of organic acids such as SA have been reported to be involved in tumor promotion. Immunohistochemical analysis of renal tubules and Western blotting analysis of urine revealed the presence of alpha 2a-g in all three strains examined. These data suggest that differences in susceptibility to promotion are due to genetic factors rather than dietary factors and the ability to synthesize alpha 2a-g.

[Japanese version of the Neuropsychiatric Inventory--a scoring system for neuropsychiatric disturbance in dementia patients]

BACKGROUND AND PURPOSE

Neuropsychiatric disturbances are common and burdensome symptoms of dementias. Assessment and measurement of neuropsychiatric disturbances are indispensable to the management of patients with dementia and for clinical research. No standardized instruments have been developed for these purposes in Japan. The Neuropsychiatric Inventory (NPI), developed by Cummings et al., is a standardized, validated, and reliable tool to assess a wide range of neuropsychiatric derangements in patients with dementia, and has been used in clinical studies in North America. In this study, we prepared a Japanese version of the NPI and tested its reliability and usefulness in dementia patients.

SUBJECTS AND METHODS

The subjects were 174 patients with dementia, including Alzheimer's disease (140), frontotemporal dementia (12), vascular dementia (19), and normal pressure hydrocephalus (3), whose diagnosis was made on the basis of the results of extensive examinations including MRI and PET/SPECT of the brain and appropriate clinical diagnostic criteria for each disorder. The subjects consisted of 133 women and 41 men; their mean age was 72.6 +/- 7.7 years (S.D.; range: 49 to 88) years. An examiner (neurologist) used the NPI to interview a caregiver familiar with the patient's everyday behavior. In 24 randomly selected patients interview was repeated by another examiner (psychiatrist) one month later, and test-retest reliability was evaluated. The Clinical Dementia Rating (CDR), the Mini-Mental State Examination (MMSE), and the Alzheimer's Disease Assessment Scale (ADAS) were used to assess the severity of the dementia and cognitive impairment.

RESULTS

The MMSE scores ranged from 5 to 29 (mean +/- SD = 19.0 +/- 4.8) and the ADAS scores ranged from 7 to 63 (24.3 +/- 10.9). The CDR score was 0.5 in 17 patients, 1 in 95 patients, 2 in 52 patients, and 3 in 10 patient. Test-retest reliability of each score was acceptably high, and the correlation coefficient for each score obtained by repeated assessments in this study was similar to the coefficient in the original report. Apathy was the most common behavior in the ten abnormal behavioral domains, and euphoria was the least common. The prevalence of abnormal findings was also comparable to the results in the original report. The total NPI scores and many of the NPI subscale scores were significantly correlated with both the severity of dementia and cognitive impairment.

CONCLUSIONS

This Japanese version of NPI, whose reliability and competency are comparable to those of the original version, is a reliable and useful tool for measuring neuropsychiatric disturbances in dementia patients.

[Magnetic resonance imaging of brainstem lesions in a case of neuro-Behçet disease]

We reported a 28-year-old man with multiple lesions in the brainstem which were clearly identified and followed up with MRI. He had been treated for Behçet uveitis using cyclosporine and colchicine during the past 5 years, and he acutely presented with fever and headache, followed left hemiparesis, dysarthria and dysphagia. MRI on admission revealed multiple lesions in the ventral pontine region which showed mixed-intensity on T1WI, high-intensity on T2WI and enhancement with Gd-DTPA. His clinical symptoms spontaneously and gradually improved, but more rapidly improved due to additional administration of corticosteroid. The lesions in the brainstem became smaller and finally rudimentary during two months after the onset of neurological symptoms.

Cholesterol and bile acid metabolism after selective portal vein ligation

AIM

To examine the regulatory effect of bile acid level on bile acid synthesis in the liver.

METHODS

The portal branch perfusing left lateral and median lobes of the liver was ligated in rats and the activities of hepatic microsomal cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme of bile acid synthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, and intrahepatic concentrations of cholesterol and bile acids were determined in the liver lobes deprived of and supplied with portal blood on Days 0, 1, 2, 4, and 7 after selective portal vein ligation (SPVL).

RESULTS

In the portal vein (PV)-ligated lobes, liver weight decreased, hepatic cholesterol concentration was unchanged, and microsomal cholesterol concentration increased after SPVL. In the PV-nonligated lobes, liver weight increased, hepatic cholesterol concentration increased, and microsomal cholesterol concentration was unchanged. There were no significant differences in the activities of HMG-CoA reductase and cholesterol 7 alpha-hydroxylase among the PV-ligated and PV-nonligated lobes and the sham-operated controls. Intrahepatic bile acid level increased significantly in the PV-nonligated lobes for 4 days after SPVL, whereas those were essentially constant in the PV-ligated and the sham-operated control liver. Despite significant changes in the concentrations of intrahepatic cholesterol and bile acid, no significant correlations were observed between these concentrations and the activities of cholesterol 7 alpha-hydroxylase.

CONCLUSIONS

SPVL causes atrophy and hypertrophy of the PV-ligated and nonligated liver lobes, respectively, without any significant changes in cholesterol and bile acid synthesis. Intrahepatic concentrations of bile acids and cholesterol have no regulatory effect on cholesterol 7 alpha-hydroxylase activity in the SPVL rat model.

Linkage map of Syrian hamster with restriction landmark genomic scanning

We have constructed the linkage map with precise genetic analysis of the Syrian hamster, Mesocricetus auratus, according to the restriction landmark genomic scanning (RLGS) spot mapping method. Although only 3.2-6.6% of the total RLGS spots between the two strains, ACN and BIO 14.6, showed genetic variance, 572 loci were found to be polymorphic. Out of 569 RLGS loci and 3 other loci, 531 were mapped with the backcross (ACN x BIO 14.6) F1 x BIO 14.6. The cumulative map was 1111.6 cM, indicating that the spots/loci are located throughout the genome at 1.94 cM intervals on average. Thus, RLGS provides us with a rapid tool to construct the genetic map of any species, even if it has less genetic variation.

A unique downregulation of h2-calponin gene expression in Down syndrome: a possible attenuation mechanism for fetal survival by methylation at the CpG island in the trisomic chromosome 21

To understand the effect of trisomic chromosome 21 on the cause of Down syndrome (DS), DNA methylation in the CpG island, which regulates the expression of adjacent genes, was investigated with the DNAs of chromosome 21 isolated from DS patients and their parents. A methylation-sensitive enzyme, BssHII, was used to digest DNAs of chromosome 21, and the resulting DNA fragments were subjected to RLGS (restriction landmark genomic scanning). Surprisingly, the CpG island of the h2-calponin gene was shown to be specifically methylated by comparative studies with RLGS and Southern blot analysis. In association with this methylation, h2-calponin gene expression was attenuated to the normal level, although other genes in the DS region of chromosome 21 were expressed dose dependently at 1.5 times the normal level. These results and the high miscarriage rate associated with trisomy 21 embryos imply that the altered in vivo methylation that attenuates downstream gene expression, which is otherwise lethal, permits the generation of DS neonates. The h2-calponin gene detected by the RLGS procedure may be one such gene that is attenuated.

Alteration of white matter MR signal intensity in frontotemporal dementia

PURPOSE

To determine the diagnostic potential of MR imaging to show white matter involvement in frontotemporal dementia.

METHODS

We evaluated MR signal intensity in cerebral white matter by visually inspecting and by quantitatively measuring signal intensity on MR images in 22 patients with frontotemporal dementia. The findings were compared with those in 22 age- and sex-matched patients who had had Alzheimer disease for the same length of time and with 16 age- and sex-matched healthy control subjects.

RESULTS

Patients with frontotemporal dementia had a significant increase in white matter signal intensity in the frontal and/or temporal lobes on T2- and proton density-weighted images. Visual inspection of regular proton density-weighted images and measurements made on the T2- and proton density-weighted images were sensitive to changes in white matter signal.

CONCLUSION

Increased MR signal intensity in the frontotemporal white matter on T2- and proton density-weighted MR images is a useful diagnostic sign of frontotemporal dementia and distinguishes this condition from Alzheimer disease.

Clinical significance of bcl-2 gene expression in human breast cancer tissues

The expression of estrogen receptor (ER) and bcl-2 (Bcl-2), an apoptosis protective oncogene, in normal and cancerous breast duct epithelia was immunohistochemically examined in fresh frozen tumor tissues from 142 Japanese breast cancer patients. The clinico-pathological characteristics and the disease free survival of the patients were analyzed. The expression of both the proteins was also observed in intraductal components of breast cancer. Although less than 1% of normal duct epithelia expressed ER, Bcl-2 was diffusely expressed. The expression of both these proteins in breast cancer significantly correlated with each other. Their expression significantly correlated negatively with tumor size but not with lymph node status. The papillo-tubular sub-type of invasive ductal carcinoma expressed Bcl-2 significantly more frequently than the solid-tubular sub-type. Patients with Bcl-2 expressing tumors survived without recurrence significantly more than those with tumors exhibiting reduced expression. Papillary-cribriform type intraductal components expressed both those proteins more often than the solid-comedo type.

Premorbid brain size as a determinant of reserve capacity against intellectual decline in Alzheimer's disease

OBJECTIVE

Both the magnitude of brain atrophy and premorbid brain size determine the volume of the brain affected by Alzheimer's disease. To examine the possibility that premorbid brain volume is a determinant of cognitive reserve in patients with Alzheimer's disease, the relation between diffuse brain atrophy and cognitive decline and the impact of premorbid brain size on cognitive decline were studied in patients with Alzheimer's disease.

METHOD

By measuring whole brain volume and intracranial volume in 60 patients with probable Alzheimer's disease, mild to moderate in severity, with the use of high-resolution magnetic resonance imaging and image processing, the authors studied the impact of premorbid brain volume and magnitude of diffuse brain atrophy on cognitive functions. On the basis of the normative brain-calvarium relationship derived from data an 28 healthy adults and the total intracranial volume measure of each patient, the magnitude of brain atrophy and premorbid brain volume were estimated.

RESULTS

After control for the effects of age, sex, and education as confounding factors, it was found that the Alzheimer's disease patients' intelligence was correlated both positively with premorbid brain volume and negatively with magnitude of brain atrophy, while impairments in language and memory were correlated with magnitude of brain atrophy but not with premorbid brain volume.

CONCLUSIONS

These findings partially support the hypothesis that premorbid brain volume is a determinant of reserves against intellectual decline in Alzheimer's disease.