Determination of free and total homocysteine in human plasma by high-performance liquid chromatography with fluorescence detection

A simple, sensitive and precise method for the determination of both free and total homocysteine in human plasma is presented. The total homocysteine in plasma consists of free homocysteine (i.e. reduced plus oxidized homocysteine in the non-protein fraction of plasma) and protein-bound homocysteine. The thiol compounds in plasma, which are reduced or liberated from plasma proteins with tri-n-butylphosphine, are derivatized with a thiol-specific fluorogenic reagent, ammonium 7-fluorobenzo-2-oxa-1,3-diazole-4-sulphonate. The derivatives are separated by reversed-phase high-performance liquid chromatography. The concentrations (mean +/- S.D.) of free and total homocysteine in plasma from 35 normal subjects were 1.94 +/- 0.46 and 6.18 +/- 1.19 nmol/ml, respectively.

Rapid killing of human neutrophils by the potent activator phorbol 12-myristate 13-acetate (PMA) accompanied by changes different from typical apoptosis or necrosis

To elucidate the relationship between activation of neutrophils and their subsequent death, the effect of phorbol 12-myristate 13-acetate (PMA), a potent activator of neutrophils, was examined. PMA-treated neutrophils showed morphological changes quite different from those of typical apoptosis or necrosis. After fusion of the lobate nucleus, nuclear contents of chromatin uniformly decreased in compactness and soon after the nuclear envelope was broken. Even at this stage, cytoplasmic organelles did not undergo degeneration. Membrane permeability began increasing at 3 h of incubation with PMA, subsequent to nuclear change. Conventional agarose gel electrophoresis and pulsed field gel electrophoresis of DNA from PMA-treated neutrophils revealed no DNA degradation products smaller than 300 kbp. PKC inhibitors, staurosporine and H-7, prevented cytotoxicity by PMA. Furthermore, antioxidants, thiourea, dimethylthiourea, pyrrolidinethiocarbamate, and N-acetyl-L-cysteine, but not superoxide dismutase, were also active in preventing PMA cytotoxicity, suggesting that cell suicide resulting from PMA treatment is due to oxygen radicals, especially the hydroxyl radical. A certain population of neutrophils phagocytosing opsonized zymosan also showed changes similar to those observed in PMA-treated cells.

The diagnosis of mild emphysema. Correlation of computed tomography and pathology scores

Early and accurate diagnosis of emphysema is said to be invaluable for identification of clinically silent and mild emphysema. Recently, computed tomography (CT) has been much advocated for its efficacy in detailed diagnosis of emphysema, and the results have been compared with the pathology grade of emphysema in resected lung specimens. To assess the ability of high resolution CT scan in detecting and grading mild emphysema, we correlated the high resolution CT scan with the pathology grade of emphysema and the destructive index (DI) of lung specimens from 42 patients undergoing thoracotomy for a solitary pulmonary nodule. The high resolution CT scan and the cut surface of the lung, corresponding exactly to the same plane of the CT scan image, were assessed using the picture-grading system of Thurlbeck and coworkers on a scale of zero to 100. The CT scores for all patients ranged from 12 to 57, with a mean +/- SD of 22.1 +/- 9.6 using 1-mm collimation (n = 35), and from 7 to 46 with a mean +/- SD of 16.5 +/- 8.3 using 5-mm collimation (n = 33). The pathology scores ranged from 10 to 57, with a mean +/- SD of 23.2 +/- 9.8 (n = 42). The DI ranged from 15.4 to 67.1, with a mean +/- SD of 31.4 +/- 10.8 (n = 42). The CT scores using 1-mm and 5-mm collimation correlated significantly with the pathology scores (r = 0.68 and 0.76, respectively, p less than 0.001), and with the DI (r = 0.62 and 0.74, respectively, p less than 0.001). The pathology scores correlated significantly with the DI (r = 0.72, p less than 0.001). We therefore concluded that high resolution CT can help to identify the presence and grading of mild emphysema.

Association between indoor exposure to semi-volatile organic compounds and building-related symptoms among the occupants of residential dwellings

The aim of this study was to evaluate the levels of semi-volatile compounds (SVOCs) in residential detached houses in Sapporo, Japan, and whether exposure to these SVOCs was associated with the development of building-related symptoms named 'sick house syndrome' (SHS). The definition of SHS is fundamentally the same as that of the sick building syndrome (SBS). The presence of symptoms of SHS was evaluated using a validated self-administered questionnaire. Surveys and samplings of air and house dust in 41 dwellings were performed from October 2006 to January 2007, and 134 occupants responded to questionnaires. Samples were analyzed to quantify the concentrations of eight plasticizers, eleven phosphate triester flame retardants, two alkyl phenols used as anti-oxidants, and one organochlorine synergist called s-421, by gas chromatography-mass spectrometry and gas chromatography-flame photometry. The compounds frequently detected were di-n-butylphthalate, di(2-ethylhexyl)phthalate (DEHP), and dibutylhydroxytoluene in air, and DEHP and tris(2-butoxyethyl)phosphate (TBEP) in dust. Tributylphosphate was strongly and directly associated with mucosal symptoms of SHS; s-421 was also directly associated with mucosal symptoms of SHS. On the contrary, some chemicals such as diethylphthalate and TBEP were inversely associated with SHS. In future studies, we plan to assess these associations in a larger population.

PRACTICAL IMPLICATIONS

This study suggests that it may be possible to reduce building-related symptoms by altering exposure to certain SVOCs, such as tributylphosphate commonly found in ceiling and wall coverings and s-421 used as a synergist for pyrethroids. The association between SHS and s-421 suggested that use of pyrethroid insecticides could elicit symptoms of SHS. However, further studies are necessary to test the associations observed in the present study and to examine whether the SVOCs associated with symptoms are causative agents or simply surrogates for some other factor that is causing the symptoms.

Phosphorus flame retardants in indoor dust and their relation to asthma and allergies of inhabitants

Organophosphate esters are used as additives in flame retardants and plasticizers, and they are ubiquitous in the indoor environment. Phosphorus flame retardants (PFRs) are present in residential dust, but few epidemiological studies have assessed their impact on human health. We measured the levels of 11 PFRs in indoor floor dust and multi-surface dust in 182 single-family dwellings in Japan. We evaluated their correlations with asthma and allergies of the inhabitants. Tris(2-butoxyethyl) phosphate was detected in all samples (median value: 580 μg/g in floor dust, 111 μg/g in multi-surface dust). Tris(2-chloro-iso-propyl) phosphate (TCIPP) was detected at 8.69 μg/g in floor dust and 25.8 μg/g in multi-surface dust. After adjustment for potential confounders, significant associations were found between the prevalence of atopic dermatitis and the presence of TCIPP and tris(1,3-dichloro-2-propyl) phosphate in floor dust [per log10 -unit, odds ratio (OR): 2.43 and 1.84, respectively]. Tributyl phosphate was significantly associated with the prevalence of asthma (OR: 2.85 in floor dust, 5.34 in multi-surface dust) and allergic rhinitis (OR: 2.55 in multi-surface dust). PFR levels in Japan were high compared with values reported previously for Europe, Asia-Pacific, and the USA. Higher levels of PFRs in house dust were related to the inhabitants' health status.

Plasma sulfhydryl-containing amino acids in patients with cerebral infarction and in hypertensive subjects

It has been postulated that an accumulation of a sulfhydryl-containing amino acid, homocysteine in plasma may induce arteriosclerosis. In order to explore a possible contribution of homocysteine to the development of cerebral infarction in middle-aged and elderly patients, plasma sulfhydryl-containing amino acid profiles of 45 patients with cerebral infarction (CI) were compared with those of 45 normotensive and 45 hypertensive controls, and 20 patients with cerebral bleeding (CB), of similar ages and sex. The concentrations of both free and total homocysteine in plasma were highest in patients with CI among the 4 groups, while plasma free and total cysteinylglycine levels were similar. Although both free and total cysteine levels were also higher in patients with CI than in normotensive controls, the total homocysteine/total cysteine ratio was highest in patients with CI among the four groups. The hypertensive controls had higher plasma free and total concentrations than normotensive controls, but the levels did not differ between the 21 normotensive and 24 hypertensive CI patients. Our results suggest that high levels of plasma homocysteine in conjunction with hypertension could be one of the risk factors for arteriosclerotic CI.

Mechanisms for the formation of glycoxidation products in end-stage renal disease

BACKGROUND

Advanced glycation end products (AGEs) accumulate on tissue and plasma proteins in patients with renal failure far in excess of normal aging or diabetes. The aim of these studies was to elucidate the nature of the precursors and the pathways that lead to an accelerated formation of two structurally identified AGEs [pentosidine and Nepsilon(carboxymethyl)lysine (CML)] in the uremic milieu.

METHODS

Serum levels of the glycoxidation products, pentosidine and CML, were quantitated by high-performance liquid chromatography in uremic patients treated by dialysis. The formation of early glycation products (as furosine) and late glycoxidation products was modeled in uremic serum and in spent peritoneal dialysate.

RESULTS

Clinical factors that affect circulating levels of AGEs included dialysis clearance and dialyzer membrane pore size, but not the presence or absence of diabetes. Both pentosidine and CML form at an accelerated rate in serum from uremic patients. Chelating agents most effectively slow the formation in vitro. In uremic fluids, the primary mechanism of formation of pentosidine is through the Amadori pathway. The primary mechanism of formation of CML is through metal-chelated autoxidation of reducing sugars generating reactive carbonyl precursors. In uremic serum, the presence of an unidentified reactive low molecular weight precursor accelerates the formation of pentosidine.

CONCLUSIONS

The formation of the two glycoxidation products, pentosidine and CML, proceeds by different pathways and is enhanced by different precursors in the uremic milieu. The formation of both AGEs is markedly enhanced by metal-catalyzed reactions, evidence for the presence of increased metal-ion mediated oxidant stress in uremia.

Cognitive dysfunction associates with white matter hyperintensities and subcortical atrophy on magnetic resonance imaging of the elderly diabetes mellitus Japanese elderly diabetes intervention trial (J-EDIT)

BACKGROUND

Type 2 diabetes is associated with cognitive dysfunction and increases the risk of dementia in the elderly. The aim of this study was to explore, by means of magnetic resonance (MR) imaging, possible relationships among clinical profiles of diabetes, cognitive function, white matter hyperintensities (WMHs) and subcortical brain atrophy.

METHODS

Data were obtained from 95 nondemented type 2 diabetic participants aged 65 years or over, enrolled in an intervention trial for Japanese elderly diabetic patients. Cognitive function was measured with neuropsychiatric tests, including mini-mental state examination (MMSE), verbal memory, digit symbol substitution and Stroop tests. Hyperintensity was classified into periventricular, deep white matter, thalamic and basal ganglia. Four ventricle-to-brain ratios were used to measure subcortical atrophy. To identify clinical features of diabetes, indices of glycemic control, lipid metabolism, blood pressure and complications were examined. Canonical correlation analysis and regression analysis were used to assess correlation.

RESULTS

Scores for digit symbol substitution and MMSE negatively correlated with WMHs in the parietal lobe and hyperintensities in the thalamus, respectively. Lower scores for memory and digit symbol substitution showed positive association with enlarged subcortical atrophy adjacent to lateral ventricles. There was no association between clinical pictures of diabetic patients with cognitive dysfunction and of those with morphological changes in the brain.

CONCLUSIONS

Impaired cognitive domains of the speed of mental processes and memory were associated with WMHs and subcortical atrophy. Degenerative changes in the cerebral small vessels may constitute predictive factors for the rate of cognitive dysfunction in elderly diabetic patients.

Diabetes mellitus and geriatric syndromes

Diabetes mellitus is associated with an increased prevalence and incidence of geriatric syndrome: functional disabilities, depression, fall, urinary incontinence, malnutrition and cognitive impairment. Geriatric syndrome not only leads to frailty, loss of independence and low quality of life, but also becomes a major obstacle in the treatment and care of diabetic people. The risk factors or contributing factors of geriatric symptoms are micro- and macrovascular complications, age-rated comorbid disease and aging per se. Comprehensive geriatric assessment of geriatric syndrome, including basic activities of daily living, instrumental activities of daily living, gait and balance, visual acuity, the Mini-Mental State Examination, depression scores, history and risk of fall, urination and nutrition, should be performed as part of the care of elderly diabetic patients, in particular old-old patients. Because geriatric syndromes are multifactorial and share risk factors, diabetic people with any geriatric symptoms should be treated with a common concentric strategy, such as supervised exercise therapy including muscle-strengthening training, psychological support, social support for adherence, and good glycemic control with avoidance of hypoglycemia.

Plasma homocysteine concentrations in Japanese patients with non-insulin-dependent diabetes mellitus: effect of parenteral methylcobalamin treatment

It has been postulated that the accumulation of homocysteine in plasma may induce arteriosclerosis. In order to explore the possible contribution of homocysteine to the occurrence of macroangiopathy in patients with non-insulin-dependent diabetes mellitus, the concentrations of total homocysteine in plasma were determined in 52 diabetic patients with clinical macroangiopathy, 84 diabetic patients without macroangiopathy, and 57 non-diabetic control subjects. The levels of total homocysteine in plasma were significantly higher in diabetic patients with macroangiopathy (10.8 +/- 3.8 nmol/ml) than in those without macroangiopathy (8.3 +/- 3.1 mmol/ml, P < 0.001) or non-diabetic subjects (7.5 +/- 2.1 nmol/ml, P < 0.001). Among all diabetic patients, multiple logistic regression analysis after adjustment for age, sex, and systolic blood pressure revealed that high levels of plasma homocysteine were significantly associated with the presence of diabetic macroangiopathy (P = 0.01). By an intramuscular injection of 1000 micrograms methylcobalamin daily for 3 weeks, the plasma levels of homocysteine in 10 diabetic patients were significantly decreased (14.7 +/- 7.5 vs. 10.2 +/- 6.0 nmol/ml, P < 0.01). Our results suggest that plasma homocysteine levels could be one of a number of independent risk factors for macroangiopathy in patients with diabetes mellitus and that they can be reduced by parenteral treatment with methylcobalamin.

Predicting macro- and microvascular complications in type 2 diabetes: the Japan Diabetes Complications Study/the Japanese Elderly Diabetes Intervention Trial risk engine

OBJECTIVE

To develop and validate a risk engine that calculates the risks of macro- and microvascular complications in type 2 diabetes.

RESEARCH DESIGN AND METHODS

We analyzed pooled data from two clinical trials on 1,748 Japanese type 2 diabetic patients without diabetes complications other than mild diabetic retinopathy with a median follow-up of 7.2 years. End points were coronary heart disease (CHD), stroke, noncardiovascular mortality, overt nephropathy defined by persistent proteinuria, and progression of retinopathy. We fit a multistate Cox regression model to derive an algorithm for prediction. The predictive accuracy of the calculated 5-year risks was cross-validated.

RESULTS

Sex, age, HbA1c, years after diagnosis, BMI, systolic blood pressure, non-HDL cholesterol, albumin-to-creatinine ratio, atrial fibrillation, current smoker, and leisure-time physical activity were risk factors for macro- and microvascular complications and were incorporated into the risk engine. The observed-to-predicted (O/P) ratios for each event were between 0.93 and 1.08, and Hosmer-Lemeshow tests showed no significant deviations between observed and predicted events. In contrast, the UK Prospective Diabetes Study (UKPDS) risk engine overestimated CHD risk (O/P ratios: 0.30 for CHD and 0.72 for stroke). C statistics in our Japanese patients were high for CHD, noncardiovascular mortality, and overt nephropathy (0.725, 0.696, and 0.767) but moderate for stroke and progression of retinopathy (0.636 and 0.614). By combining macro- and microvascular risks, the classification of low- and high-risk patients was improved by a net reclassification improvement of 5.7% (P = 0.02).

CONCLUSIONS

The risk engine accurately predicts macro- and microvascular complications and would provide helpful information in risk classification and health economic simulations.

Genotype-phenotype correlations in alternating hemiplegia of childhood

OBJECTIVE

Clinical severity of alternating hemiplegia of childhood (AHC) is extremely variable. To investigate genotype-phenotype correlations in AHC, we analyzed the clinical information and ATP1A3 mutations in patients with AHC.

METHODS

Thirty-five Japanese patients who were clinically diagnosed with AHC participated in this study. ATP1A3 mutations were analyzed using Sanger sequencing. Detailed clinical information was collected from family members of patients with AHC and clinicians responsible for their care.

RESULTS

Gene analysis revealed 33 patients with de novo heterozygous missense mutations of ATP1A3: Glu815Lys in 12 cases (36%), Asp801Asn in 10 cases (30%), and other missense mutations in 11 cases. Clinical information was compared among the Glu815Lys, Asp801Asn, and other mutation groups. Statistical analysis revealed significant differences in the history of neonatal onset, gross motor level, status epilepticus, and respiratory paralysis in the Glu815Lys group compared with the other groups. In addition, 8 patients who did not receive flunarizine had severe motor deteriorations.

CONCLUSIONS

The Glu815Lys genotype appears to be associated with the most severe AHC phenotype. Although AHC is not generally seen as a progressive disorder, it should be considered a disorder that deteriorates abruptly or in a stepwise fashion, particularly in patients with the Glu815Lys mutation.

Muscle histopathology in spastic cerebral palsy

We studied the histopathology of spastic muscles in patients with spastic cerebral palsy using specimens obtained from the gastrocnemius muscles during orthopedic operations. Though there was no disease-specific abnormality, we found changes in fiber type distribution, i.e., type-1 fiber predominance and type-2B fiber deficiency. These changes were not found in the patient with brain infarction at age 1 year 5 months. Variation in fiber size, especially in type-1 fibers, was also detected in older patients and at the more severely affected sides. We speculated that the influence on the spinal motor unit from upper motor cortex might be applicable to the muscle histological findings and the time of the onset of the brain damage might be important.

Dietary sodium intake and incidence of diabetes complications in Japanese patients with type 2 diabetes: analysis of the Japan Diabetes Complications Study (JDCS)

CONTEXT

Many guidelines recommend that patients with type 2 diabetes should reduce their dietary sodium intake. However, the relationship between dietary sodium intake and incidence of diabetic complications in patients with type 2 diabetes has not been explored.

OBJECTIVE

Our objective was to investigate the relationship between dietary sodium intake and incidence of diabetes complications.

PARTICIPANTS

The study was of a nationwide cohort of patients with type 2 diabetes aged 40 to 70 years with hemoglobin A1c (HbA1c) ≥6.5%.

MAIN OUTCOME MEASURES

After excluding nonresponders to a dietary survey, 1588 patients were analyzed. Baseline dietary intake was assessed by the Food Frequency Questionnaire based on food groups. Primary outcomes were times to cardiovascular disease (CVD), overt nephropathy, diabetic retinopathy, and all-cause mortality.

RESULTS

Mean daily dietary sodium intake in quartiles ranged from 2.8 to 5.9 g. After adjustment for confounders, hazard ratios for CVD in patients in the second, third, and fourth quartiles of sodium intake compared with the first quartile were 1.70 (95% confidence interval, 0.98-2.94), 1.47 (0.82-2.62), and 2.07 (1.21-3.90), respectively (trend P < .01). In addition, among patients who had HbA1c ≥9.0%, the hazard ratio for CVD in patients in the top vs bottom quartile of sodium intake was dramatically elevated compared with patients with HbA1c <9.0% (1.16 [0.56-2.39] and 9.91 [2.66-36.87], interaction P < .01). Overt nephropathy, diabetic retinopathy, and all-cause mortality were not significantly associated with sodium intake.

CONCLUSIONS

Findings suggested that high dietary sodium intake is associated with elevated incidence of CVD in patients with type 2 diabetes and that there is a synergistic effect between HbA1c values and dietary sodium intake for the development of CVD.

Prevalence of frailty, cognitive impairment, and sarcopenia in outpatients with cardiometabolic disease in a frailty clinic

Background

Although frailty and cognitive impairment are critical risk factors for disability and mortality in the general population of older inhabitants, the prevalence and incidence of these factors in individuals treated in the specialty outpatient clinics are unknown.

Methods

We recently established a frailty clinic for comprehensive assessments of conditions such as frailty, sarcopenia, and cognition, and planned 3-year prospective observational study to identify the risk factors for progression of these aging-related statuses. To date, we recruited 323 patients who revealed symptoms suggestive of frailty mainly from a specialty outpatient clinic of cardiology and diabetes. Frailty status was diagnosed by the modified Cardiovascular Health Study (mCHS) criteria and some other scales. Cognitive function was assessed by Mini-Mental State Examination (MMSE), Japanese version of the Montreal Cognitive Assessment (MoCA-J), and some other modalities. Sarcopenia was defined by the criteria of the Asian Working Group for Sarcopenia (AWGS). In this report, we outlined our frailty clinic and analyzed the background characteristics of the subjects.

Results

Most patients reported hypertension (78%), diabetes mellitus (57%), or dyslipidemia (63%), and cardiovascular disease and probable heart failure also had a higher prevalence. The prevalence of frailty diagnosed according to the mCHS criteria, cognitive impairment defined by MMSE (≤27) and MoCA-J (≤25), and of AWGS-defined sarcopenia were 24, 41, and 84, and 31%, respectively. The prevalence of frailty and cognitive impairment increased with aging, whereas the increase in sarcopenia prevalence plateaued after the age of 80 years. No significant differences were observed in the prevalence of frailty, cognitive impairment, and sarcopenia between the groups with and without diabetes mellitus, hypertension, or dyslipidemia with a few exceptions, presumably due to the high-risk subjects who had multiple cardiovascular comorbidities. A majority of the frail and sarcopenic patients revealed cognitive impairment, whereas the frequency of suspected dementia among these patients were both approximately 20%.

Conclusions

We found a high prevalence of frailty, cognitive impairment, and sarcopenia in patients with cardiometabolic disease in our frailty clinic. Comprehensive assessment of the high-risk patients could be useful to identify the risk factors for progression of frailty and cognitive decline.

Long-term multiple risk factor interventions in Japanese elderly diabetic patients: the Japanese Elderly Diabetes Intervention Trial--study design, baseline characteristics and effects of intervention

AIM

To evaluate long-term, multiple risk factor intervention on physical, psychological and mental prognosis, and development of complications and cardiovascular disease in elderly type 2 diabetes patients.

METHODS

Our randomized, controlled, multicenter, prospective intervention trial included 1173 elderly type 2 diabetes patients who were enrolled from 39 Japanese institutions and randomized to an intensive or conservative treatment group. Glycemic control, dyslipidemia, hypertension, obesity, diabetic complications and atherosclerotic disease were measured annually. Instrumental activity of daily living, cognitive impairment, depressive symptoms and diabetes burden were assessed at baseline and 3 years.

RESULTS

There was no significant difference in clinical or cognitive parameters at baseline between the two groups. The prevalence of low activities of daily living, depressive symptoms and cognitive impairment was 13%, 28% and 4%, respectively, and was similar in the two groups. A small, but significant difference in HbA1c between the two groups was observed at 1 year after the start of intervention (7.9% vs 8.1%, P < 0.05), although this significant difference was not observed after the second year. With the exception of coronary revascularization, there was no significant difference in fatal or non-fatal events between the two groups. Composite events were also similar in the two groups.

CONCLUSIONS

This study showed no significant differences in fatal or non-fatal events between intensive and conventional treatment. The present study might clarify whether treatment of risk factors influences function and quality of life in elderly diabetic patients.

Examination of Practicability of Communication Robot-Assisted Activity Program for Elderly People

We have developed a Robot Assisted Activity (RAA) program for recreational use in health care facilities for elderly people. The RAA program has been evaluated in such a facility to assess its usefulness. The program applies a standard classroom model, starting with homeroom and including lessons in the Japanese language, music, gymnastics, arithmetic, and other subjects. At the end of the program, there is a graduation ceremony. We use a video camera to record each scene. Each behavior and utterance of the participants is then analyzed. In addition, immediately upon completion of the RAA program, specialists conduct a Focus Group Interview (FGI) in which they collect comments, opinions, and requests from the participants. Ten elderly people participate in the program, two men and eight women (81.0±3.7 years old). All are residents at a health care facility in Aichi Prefecture, Japan. TheMMSE (MiniMental State Examination) score indicating the level of dementia is 24.1±3.0 points. Two participants are judged to be in a moderate stage of cognitive decline (21 points or less), six are in a mild stage (22-26 points), and the remaining two are normal. On the Geriatric Depression Scale (GDS), in which a score of 13.3±4.2 points indicates a state of depression, seven participants are judged to be depressive (11 points or more). The results of our study show that all participants have a favorable impression of the robot and nearly all have a positive opinion of the RAA program. This suggests that the program can be used for emotional and recreational therapy at health care facilities for the elderly. However, in spite of the overall success of the RAA program, we seldom observe interaction between participants and the robot.

Diabetes mellitus and white matter hyperintensity

White matter hyperintensity (WMH) is a brain lesion detected as a high-intensity area in magnetic resonance imaging T2 and fluid-attenuated inversion recovery images, and it has been suggested that WMH reflects damage to small vessels in periventricular and subcortical areas. Although WMH has been linked to the incidence of stroke, more recently it has been clarified that WMH is also associated with progression of cognitive decline and functional disability, which are components of so-called geriatric syndrome. In addition to hypertension, which is the classical risk factor for WMH, evidence has been accumulating to suggest that diabetes mellitus could also be associated with WMH progression, and some studies have shown that WMH severity is correlated with cognitive decline in patients with diabetes. The factors that accelerate WMH formation in elderly patients with diabetes remain poorly defined. It is considered that insulin resistance is an exacerbating factor, but the effects of hypertension, dyslipidemia or other vascular risk factors have yet be clarified, and further studies are required.

Successful control with bromide of two patients with malignant migrating partial seizures in infancy

A 3-month-old male and a 4-month-old female infant with intractable seizures were diagnosed as having malignant migrating partial seizures in infancy (MMPSI) with developmental arrest on the basis of characteristics of symptoms, clinical courses and EEGs. We treated these two patients with potassium bromide (80 mg/kg) after conventional antiepileptic drugs failed to adequately control the seizures. The potassium bromide therapy resulted in complete control of seizures in one patient, and more than 95% reduction in seizure frequency in the other.

Risk factors associated with falls in elderly patients with type 2 diabetes

AIMS

This study investigated risk factors of falls in elderly patients with type 2 diabetes mellitus.

METHODS

A total of 211 patients aged ≧60years (168 diabetic patients and 43 non-diabetic control subjects) were studied. Factors associated with falls in the past year were retrospectively examined using multiple logistic regression analysis.

RESULTS

The prevalence of patients who had a history of falls in the past year was twice as high as in diabetic patients compared in control subjects (36.9% vs. 18.6%, P<0.05). When diabetic patients were exclusively analyzed, the presence of any level of hypoglycemia and the Timed Up and Go test (TUG) scores correlated with patients' falls. The presence of hypoglycemia (OR 3.62, 95% CI: 1.242-10.534, P=0.018), cognitive impairment (OR 3.63, 95% CI: 1.227-10.727, P=0.020), and high Fall Risk Index scores (OR 1.2, 95% CI: 1.010-1.425, P=0.039) was independently correlated with the presence of multiple falls. When the diabetic patients were divided into three groups according to the frequency of hypoglycemia episodes, the prevalence of falls increased as the frequency of hypoglycemia increased.

CONCLUSION

Hypoglycemia was a risk factor of falls in elderly type 2 diabetic patients.

Improved method for mutagenicity testing of gaseous compounds by using a gas sampling bag

A simple and safety gas exposure method was developed using a gas sampling bag as an exposure vessel and a preparation vessel of diluted gas. The gas exposure conditions such as amount of S9 in the plate, volume of gas for the plate, amount of top agar, exposure period and exposure temperature were examined by mutagenicity testing of 1,3-butadiene using the gas sampling bag. Mutagenicity tests of 14 compounds and 1,3-butadiene on S. typhimurium TA98, TA100, TA1535 and TA1537, and E. coli WP2 uvrA were also examined by the developed gas exposure method. 1,3-Butadiene, propyne (methyl acetylene), monochlorodifluoromethane, ethylchloride, diborane and silane were mutagenic. 1-Butene, 2-butene, 2-methylpropene, methyl vinyl ether, trichlorofluoromethane, dichlorodifluoromethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, 1,1-difluoroethane and phosphine were not mutagenic on S. typhimurium TA98, TA100, TA1535 and TA1537, and E. coli WP2 uvrA with or without metabolic activation. These results were compatible with a previous report, and this developed method has the advantage that it can be tested easily and safely for combustible and self-combustible substances such as 1,3-butadiene and silane.