Normal pressure hydrocephalus in diabetic patients with recurrent episodes of hypoglycemic coma

The pathophysiology of brain damage induced by severe hypoglycemia is still unknown. We experienced a case with type 1 diabetes and recurrent severe hypoglycemic coma who showed a central brain atrophy and an abnormal cerebrospinal fluid flow, suggesting normal pressure hydrocephalus. Following this case, the CSF flow was studied using 111In-DTPA cisternography in six consecutive diabetic patients admitted for repeated episodes of hypoglycemic coma. All the patients showed the central brain atrophy on computed tomography and four of them (67%) had the ventricular reflux, with delayed clearance of 111In-DTPA. Two patients with abnormal CSF flow showed cognitive dysfunction by WAIS or WAIS-R. In contrast, none of five randomly selected diabetic patients, without hypoglycemic coma showed abnormal CSF flow. Our results suggest the presence of normal pressure hydrocephalus in diabetic patients with recurrent hypoglycemic coma. It may associate with the cognitive dysfunction.

Ruptured retroperitoneal mucinous cystadenocarcinoma with synchronous gastric carcinoma and a long postoperative survival: case report

We describe an 86-year-old woman with a long survival following surgey for a massive retroperitoneal mucinous cystadenocarcinoma and a synchronous gastric carcinoma. Computed tomography showed a huge tumor with septation and calcification. Upper gastrointestinal radiography showed the additional gastric lesion. At operation, the 23 x 20 x 12-cm retroperitoneal tumor had ruptured. Tumor resection and distal gastrectomy including regional lymph nodes were performed. Mucinous peritoneal implants were removed as completely as possible. Histologically, the mucinous tumor showed limited invasion, whereas the poorly differentiated gastric adenocarcinoma showed no serosal invasion. Among 18 retroperitoneal mucinous cystadenocarcinomas reported in the English literature since 1965, only ours was associated with gastric carcinoma. Despite peritoneal implants, our patient has survived for 6 years without clinical recurrence. As at other sites, retroperitoneal mucinous cystadenocarcinoma often grows slowly. Total removal, even after peritoneal dissemination, can result in long survival.

[Clinical evaluation of acute and chronic pulmonary thromboembolism using intravascular ultrasound and angioscopy]

Pulmonary artery thrombi and parietal lesions were observed in 13 patients (mean age 58 +/- 18 years) with acute pulmonary thromboembolism (n = 4) and chronic pulmonary thromboembolism (n = 9) using intravascular ultrasound and angioscopy at the time of right heart catheterization. Patients with acute pulmonary thromboembolism without underlying disease mainly had non-echogenic intraluminal mass, and good pulsatile vessel without intimal thickening. Angioscopy directly showed red thrombi with white fibrin coating, and no parietal lesions. Patients with chronic pulmonary thromboembolism could be classified into 3 groups: 1) Poor extensibility of the vessel wall and intimal thickening with non-echogenic thrombi on intravascular ultrasound, and relatively fresh parietal thrombi consisting of a mixture of red blood cell and fibrin, and spider web-like fibrin net on angioscopy (6 patients). 2) Crescent parietal thrombi and wall irregularity on intravascular ultrasound, and probably organized thrombi with a mixture of red and white surface on angioscopy (one patient). 3) Marked and echogenic intimal thickening and poor extensibility on intravascular ultrasound, and intimal surface irregularities and yellowish changes on angioscopy (one patient). All patients suffering acute deterioration in the chronic phase belonged to groups 1) or 2). Intravascular ultrasound and angioscopy are useful for characterizing the thrombi and related pulmonary artery lesions in patients with pulmonary thromboembolism. The pulmonary artery intima and thrombus differ between acute and chronic pulmonary thromboembolism.

Suppression of sodium-dependent glucose uptake by captopril improves high-glucose-induced morphological and functional changes of cultured bovine retinal pericytes

The effects of captopril on glucose uptake, as well as morphological and functional changes of retinal pericytes, in a high-glucose medium were examined. Retinal pericytes were incubated in medium with 5 and 30 mM glucose and 30 mM glucose with 10(-6) to 10(-3) M captopril. Captopril decreased the cellular uptakes of d-glucose and alpha-methyl glucoside in the presence, but not in the absence, of sodium. The cellular size and contents of glucose, sorbitol, and fructose were increased in 30 mM glucose concomitant with the decreased thymidine, cellular DNA content, and ratios in glucose to sorbitol and to fructose, compared with those in 5 mM glucose. These changes observed in 30 mM glucose were reversed by 10(-4) M captopril. These data suggest that the suppression of d-glucose uptake through a sodium-coupled glucose transporter by captopril may attenuate the swelling and loss of pericytes observed in the early stage of diabetic retinopathy.

Decreased antipyrine clearance following endotoxin administration: in vivo evidence of the role of nitric oxide

Klebsiella pneumoniae endotoxin has been found to decrease hepatic P450-mediated drug-metabolizing enzyme activity in a time-dependent manner. In this study, we investigated the role of nitric oxide (NO) in the decrease in hepatic drug-metabolizing enzyme activity caused by endotoxin in vivo. We measured in vivo pharmacokinetic parameters of antipyrine in rats treated with endotoxin and/or a selective inhibitor of inducible NO synthase (iNOS), S-methylisothiourea. Intraperitoneal injection of endotoxin (1 mg/kg of body weight) dramatically decreased the systemic clearance of antipyrine, reflecting reduced hepatic drug-metabolizing enzyme activity, and significantly increased the level of nitrite and nitrate (NOx) in the plasma. S-Methylisothiourea (10 mg/kg) reversed this decreasing antipyrine clearance and reduced the level of NOx in plasma. Repeated injections of an NO donor, (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide (FK-409; 10 mg/kg), at a dose which maintained plasma NOx at the same levels as those caused by endotoxin injection, also decreased the systemic clearance of antipyrine. These findings suggest that the overproduction of NO observed in this animal model is at least partially responsible for the significant reduction in the hepatic drug-metabolizing enzyme activity that may happen in a gram-negative bacterial infection.

Lysophosphatidylcholine molecular species in low density lipoprotein and high density lipoprotein in alloxan-induced diabetic rats: effect of probucol

To elucidate the contribution of diabetic state toward the accumulation of lysophosphatidylcholine (LPC) in low density lipoprotein (LDL), the LPC molecular species in LDL and high density lipoprotein (HDL) obtained from alloxan-induced diabetic rats were determined by high performance liquid chromatography. The palmitoyl LPC (PLPC) per protein was increased in the LDL of diabetic rats (p < 0.05), whereas the stearoyl LPC (SLPC) decreased in both the LDL and HDL of diabetic rats (p < 0.001) in comparison to nondiabetic rats. After the dietary administration of probucol for 4 weeks, the concentrations of SLPC and PLPC in the LDL of diabetic rats and of SLPC in the LDL of nondiabetic rats all significantly decreased by probucol (all; p < 0.01), with a concomitant decrease of the plasma concentrations of total and HDL cholesterol, and phospholipid, compared with those without probucol. The level of TBARS per protein in LDL increased in diabetic rats, and decreased by probucol (p < 0.01). In conclusion, the oxidative stress is thought to be an important factor to accumulate LPC in LDL, although the paradoxical decrease of SLPC in diabetic LDL suggests a non-oxidative metabolism with a preference for the LPC molecular species. The reducing effect of probucol on LPC may not be solely attributed to its antioxidative effect.

Pyogenic infection of the pubic symphysis in a diabetic patient

A 51-year-old woman with diabetes mellitus had swelling in the inguinal area leading to discharge. Insulin, irrigation of the wound and intravenous antibiotics had no effect. Fistulography and a fistula-CT showed a fistula connecting to the pubis symphysis. After curettage of the pubic symphysis, the wound was closed.

Elevated production of salivary nitric oxide in oral mucosal diseases

Nitric oxide (NO) is known to play an important role in biological systems. In this study, we measured levels of NO in the saliva of 39 patients with oral mucosal diseases: 21 had oral lichen planus (OLP) and 18 had recurrent aphthous ulceration (RAU). NO was assayed using the Griess reagent, which measures nitrite (NO2), the byproduct of NO. NO2 was detected in all tested samples, and levels in the saliva of patients were significantly increased relative to those of healthy subjects. We also examined the effect of NO on fibroblasts, keratinocytes and NA cells (an epithelial cancer cell line) in vitro. S-nitroso-N-acetyl-DL-penicillamine (SNAP) and 3-morpholinosydnonimine (SIN-1) were used as NO donating reagents. The results revealed that cell viability was significantly reduced by NO derived from SNAP and SIN-1 in a dose-dependent manner. Although the role of salivary NO in normal physiology is as yet unknown, these findings suggest that excessive salivary NO plays a potential role in modifying oral mucosal diseases as a physiopathological regulator.

Beta-adrenergic receptor-G protein-adenylyl cyclase signal transduction in the failing heart

The beta-adrenergic receptor signal transduction pathway is critical for rapid adjustments to increased cardiovascular demand (e.g., during exercise). In the face of chronic stimulation of this pathway, as occurs in the pathogenesis of heart failure, beta-adrenergic receptor stimulation may become maladaptive. Under these conditions, elevation of circulating catecholamines and depletion of cardiac tissue stores of norepinephrine occur in the failing heart, resulting in desensitization. Whether or not stimulation or inhibition of the beta-adrenergic receptor signaling pathway is beneficial in heart failure is controversial. One approach to address this question is to specifically overexpress a component of the beta-adrenergic receptor signaling pathway in a transgenic mouse heart. We have characterized young and old adult mice with overexpressed cardiac G(s alpha) which couples the beta-adrenergic receptor to adenylyl cyclase. In younger animals, beta-adrenergic receptor stimulation results in an augmented heart rate and cardiac contractility. Over the life of the animal, however, a picture of cardiomyopathy develops. The result is a dilated heart with a large amount of fibrosis and myocyte hypertrophy, degeneration atrophy, and apoptosis. Conversely, chronic beta-adrenergic receptor blockade prevents the development of cardiomyopathy. These experiments support the point of view that chronic beta-adrenergic stimulation during the development of heart failure is deleterious and that protecting the heart with chronic beta-adrenergic receptor blockade is salutary, conceptually consistent with results of recent clinical trials examining the effects of beta-adrenergic receptor blockers in patients with heart failure.

Smt3, a SUMO-1 homolog, is conjugated to Cdc3, a component of septin rings at the mother-bud neck in budding yeast

SMT3 of Saccharomyces cerevisiae is an essential gene encoding a ubiquitin-like protein similar to mammalian SUMO-1. When a tagged Smt3 or human SUMO-1 was expressed from GAL1 promoter, either gene rescued the lethality of the smt3 disruptant. By indirect-immunofluorescent microscopy, the HA-tagged Smt3 was detected mostly in nuclei and also at the mother-bud neck just like septin fibers. Indeed immunoprecipitation experiments revealed that Cdc3, one of septin components, was modified with Smt3. Furthermore, the protein level of the Cdc3-Smt3 conjugate was reduced and the septin rings disappeared in a ubc9-1 mutant at a restrictive temperature, where the Smt3 conjugation system should be defective. Thus, we conclude that Smt3 was conjugated to Cdc3 in septin rings localized at the mother-bud neck. Around the time of cytokinesis the Cdc3-Smt3 conjugate disappeared. We discuss the biological significance of this Smt3 conjugation to a septin component.

In vivo and in vitro positive interference by cefpirome in measurement of serum creatinine by the Jaffe method

We report the case of an 81-year-old female patient with diverticulitis of the colon, whose symptoms were relieved by intravenous administration of cefpirome. However, her serum creatinine levels were falsely increased by the Jaffe method when serum samples were drawn after intravenous administration of cefpirome. The serum creatinine level in the same sample was within the normal range by the enzymatic method in the automated analyzer. In vitro experiment demonstrated dose-dependent positive interference of the creatinine level with cefpirome. These results indicate that we should be aware of the positive interfering effect of cefpirome when we measure serum creatinine by the Jaffe method, and that the enzymatic method should be widely used to measure serum creatinine levels to eliminate false reactions due to certain chemicals.

A profile analysis of personality disorders: beyond multiple diagnoses

The authors applied cluster analysis and multidimensional scaling to the analyses of 59 patients with personality pathology. Cluster analysis yielded eight typologies of patients: detached, anankastic, phobic, dramatic, erratic, emotional, milder emotional, and masochistic negativistic. Multidimensional scaling identified the dimensions of classifying patients: anxious rumination versus behavioural acting out, overall severity of personality pathology, and assertiveness versus withdrawal. Considering the distinction between personality disorder (dysfunctional personality) and abnormal personality (extreme personality), the following changes in current classification system are proposed: use of a hierarchy and exclusion criteria in a categorical-type model or use of a personality profile in a dimensional-trait model, in either case, with a dimensional rating for severity of psychopathology to define personality 'disorder'.

Reduced subendocardial ryanodine receptors and consequent effects on cardiac function in conscious dogs with left ventricular hypertrophy

The goal of this study was to examine the transmural distribution of ryanodine receptors in left ventricular (LV) hypertrophy (LVH) and its in vivo consequences. Dogs were chronically instrumented with an LV pressure gauge, ultrasonic crystals for measurement of LV internal diameter and wall thickness, and a left circumflex coronary blood flow velocity transducer. Severe LVH was induced by chronic banding of the aorta (12+/-1 months), which resulted in a 78% increase in LV/body weight. When ryanodine was infused directly into the circumflex coronary artery, it did not affect LV global function or systemic hemodynamics; however, it reduced LV wall thickening and delayed relaxation in the posterior wall in control dogs but was relatively ineffective in dogs with LVH. In LV sarcolemmal preparations, [3H]ryanodine ligand binding revealed a subendocardial/subepicardial gradient in normal dogs. In LVH there was a 45% decrease in ryanodine receptor binding and a loss in the natural subendocardial/subepicardial gradient, which roughly correlated inversely with the extent of LVH and directly with regional wall motion. Both mRNA and Western analyses revealed similar findings, with a reduction of the transmural mRNA levels and a loss in the natural gradient between subendocardial and subepicardial layers in LVH. Thus, ryanodine receptor message and binding in LVH is reduced preferentially in the subendocardium with consequent attenuation of the action of ryanodine in vivo. The selectively altered ryanodine regulation subendocardially in LVH could reconcile some of the controversy in this field and may play a role in mediating decompensation from stable LVH.

Impaired force-frequency relations in patients with hypertensive left ventricular hypertrophy. A possible physiological marker of the transition from physiological to pathological hypertrophy

BACKGROUND

The extent to which force-frequency and relaxation-frequency relations (FFR and RFR, respectively) and exercise-induced adrenergic stimulation affect myocardial inotropic and lusitropic reserves has not been established in patients with left ventricular (LV) hypertrophy (LVH).

METHODS AND RESULTS

We calculated the maximum first derivative of LV pressure (LV dP/dtmax) and the LV pressure half-time (T1/2) during pacing, exercise, and isoproterenol infusion in 17 patients with hypertensive LVH and 9 control subjects to investigate the influence of increases in heart rate (HR) and adrenergic stimulation on inotropic and lusitropic reserves. Group A consisted of 10 LVH patients who showed a progressive increase in the HR-LV dP/dtmax relation. Group B consisted of 7 LVH patients in whom the HR-dP/dtmax relation at physiological pacing rates was biphasic. The LV mass index was larger and the LV ejection fraction was smaller in group B than in group A (244+/-72 g/m2 versus 172+/-22 g/m2 and 55+/-18% versus 72+/-6%, respectively; both P<0.05). The increase in LV dP/dtmax was greater during exercise than pacing alone for similar increases in HR in all groups (P<0.05) (group A, 111+/-22% versus 25+/-14%; group B, 105+/-35% versus 14+/-10%; control, 111+/-24% versus 25+/-12%). T1/2 was shorter (P<0.05) during exercise than with pacing alone in all groups (group A, 41+/-6% versus 11+/-3%; group B, 38+/-9% versus 14+/-4%; control, 44+/-6% versus 12+/-5%). Isoproterenol infusion caused similar increases in LV dP/dtmax and similar decreases in T1/2 in all groups.

CONCLUSIONS

The FFR was biphasic in patients with severe LVH irrespective of LV function but was preserved in patients with less severe LVH and control subjects. Importantly, the RFR and adrenergic control of both inotropic and lusitropic reserves were well preserved in all LVH patients. A biphasic FFR at physiological pacing rates may be one of the earliest markers of the transition from physiological adaptation to the pathological process in LVH patients.

Lysophosphatidylcholine molecular species in low density lipoprotein of type 2 diabetes

To reveal the importance of lysoposphatidylcholine (LPC) in patients with Type 2 diabetes (DM), LPC in low density lipoprotein (LDL) was determined by high performance liquid chromatography in 38 patients with Type 2 DM and 31 age and sex-matched non-diabetic controls. Stearoyl LPC (SLPC) and palmitoyl LPC (PLPC) were detected in LDL. The contents of both LPCs per gram protein in LDL were increased in diabetic patients compared with the non-diabetics (1.99+/-0.94mg SLPC and 3.02+/-1.81 mg PLPC vs 1.47+/-0.57 mg SLPC and 2.30+/-0.83 mg PLPC, mean +/- SD, p < 0.01 and p < 0.05, respectively). PLPC showed a weak correlation with the levels of fasting plasma glucose (FPG) and HbA1c (r=0.27 and r=0.33, p < 0.05 and p < 0.01, respectively). The diabetic patients with macroangiopathy showed higher levels of PLPC per gram protein compared to those without macroangiopathy (4.60+/-2.61 mg vs 2.53+/1.15 mg, respectively, p < 0.05). The LPC molecular species may participate in the atherogenicity of LDL in patients with Type 2 diabetes.

Diminished facial expression despite the existence of pleasant emotional experience in schizophrenia

In order to investigate the relationship between pleasant emotional experience and facial expression (i.e., laughter), mood before and after watching comic film clips, self-rated pleasant emotional experience for each film clip and electromyographic activities of facial muscles involved in laughter while watching film clips were measured for 25 patients with schizophrenia and 20 normal controls. Patients with schizophrenia who showed a significant correlation between self-rated emotional experience and major zygomatic activity were equivalent to normal controls in self-rated emotional experience and in mood after film clips; they had a significant increase in mood scores related with pleasure. Although these patients were thought to have sufficient pleasant emotional experience, they showed significantly low major zygomatic activity as compared to normal controls. It is suggested that these patients have a disturbance in the process of emotional expression rather than emotional experience.

Stimulation of intestinal glucoreceptors in rats increases pancreatic islet blood flow through vagal mechanisms

The aim of the study was to evaluate whether intestinal glucoreceptors participate in the regulation of pancreatic islet blood flow. For this purpose, anesthetized rats were infused (0.1 ml/min for 3 min) with saline, glucose, or 3-O-methylglucose directly into the duodenum. The glucose (1 mg/kg body wt) infusion rate was chosen to prevent any effects on systemic or intraportal blood glucose concentrations. Intraduodenal infusion of D-glucose increased both serum insulin concentration and islet blood flow, whereas the osmotic control substance 3-O-methylglucose had no such effects. A bilateral abdominal vagotomy performed before the infusions totally abolished both the insulin and blood flow response to glucose infusion. The absence of an increased islet blood flow in response to glucose infusion in the denervated, transplanted pancreas was a further indication of the crucial importance of the regulation of islet blood flow by the vagus nerves. It is concluded that intestinal glucoreceptors participate in the mediation of glucose-induced islet blood flow increase.

Effect of gemfibrozil on serum levels of prostacyclin and precursor fatty acids in hyperlipidemic patients with Type 2 diabetes

Lipid-lowering fibrate drugs are known to affect the synthesis of fatty acids, which may alter the prostacyclin synthesis in diabetic patients. Therefore, the serum levels of precursor fatty acids and 6-keto-prostaglandin F1alpha (6-keto PGF1alpha) were determined in ten hyperlipidemic patients with Type 2 diabetes before and after administration of gemfibrozil (900 mg/day) for 3 months, in comparison with the results in seven non-diabetic hyperlipidemic patients. Gemfibrozil significantly reduced the serum concentration of dihomo-7-linolenic acid, total cholesterol and triglycerides, but did not affect the serum levels of arachidonic acid and 6-keto PGF1alpha in diabetic and non-diabetic patients. Thus, gemfibrozil did not affect the synthesis of prostacyclin in spite of the reduction of precursor fatty acids in diabetic and non-diabetic patients.

Central histaminergic neurons regulate rabbit tracheal tension through the cervical sympathetic nerve

We previously showed that stimulation of the posterior hypothalamus decreases tracheal tension and involves central histaminergic neurons. In the present study, we reveal that central histaminergic neurons project to the rostral ventrolateral medulla and affect cervical sympathetic nervous activity in rabbits. Administration of histamine into the fourth ventricle increased cervical sympathetic nervous activity and decreased tracheal tension. These effects were inhibited by administration of a histamine H receptor antagonist, pyrilamine, into the fourth ventricle. Unilateral injection of DL-homocysteic acid into the tuberomammillary nucleus increased cervical sympathetic nervous activity, an effect was antagonized by bilateral injection of pyrilamine into the rostral ventrolateral medulla. The pulse correlogram between the stimulation pulse applied to the tuberomammillary nucleus and the cervical sympathetic nerve activity showed a mode at 150 to 200 ms, which was reduced by pyrilamine administration into the fourth ventricle. Fibers anterogradely labeled by Phaseolus vulgaris leucoagglutinin (PHA-L) injected into the tuberomammillary nucleus were distributed in the A1, A2, C1, and C2 areas which are determined by tyrosine hydroxylase-immunohistochemistry. PHA-L positive neurons were in close contact with tyrosine hydroxylase-immunoreactive neurons in these four areas. Cell bodies in the tuberomammillary nucleus retrogradely labeled with fluorogold from the rostral ventrolateral medulla were immunoreactive with histamine. These results suggest that an excitatory efferent pathway projects from the tuberomammillary nucleus to the cervical sympathetic nerve and that the histaminergic neurons of this pathway influence tracheal tension through the rostral ventrolateral medulla.

Stroke topography in diabetic and nondiabetic patients by magnetic resonance imaging

Stroke is more frequent in diabetic than in nondiabetic patients. We studied lesion topography in 61 stroke patients with diabetes mellitus and 77 without diabetes using magnetic resonance imaging. Location, number and size of infarcts were investigated. Prevalence of hypertension did not differ between diabetic and nondiabetic patients. In elderly subgroups (> or = 65 years), infratentorial infarcts > or = 5 mm in diameter were more frequent in diabetic than in nondiabetic patients (32 vs. 12%, P < 0.05), while supratentorial infarcts were not different (56 vs. 68%, ns). Asymptomatic hemorrhage combined with silent infarction was significantly less frequent in diabetic than in nondiabetic patients (5 vs. 22%, P < 0.05). In nondiabetic patients with significant stenosis in the carotid system, supratentorial infarction measuring > or = 15 mm was more frequent than in those without stenotic lesions, but the number of infarcts per patient irrespective of size was smaller when stenosis was present. On the other hand, the number of infarcts in diabetic patients was similar between those with and without carotid system stenosis. The present study demonstrated that infratentorial infarcts were more common in elderly diabetic patients, suggesting the vulnerability of vertebrobasilar circulation in diabetes.

Trimethadione metabolism by human liver cytochrome P450: evidence for the involvement of CYP2E1

1. Caucasian liver samples were used in this study. N-demethylation of trimethadione (TMO) to dimethadione (DMO) was monitored in the presence of chemical inhibitors of CYPs, such as fluconazole, quinidine, dimethyl-nitrosamine, acetaminophen, phenacetin, chlorzoxazone and mephenytoin. Trimethadione N-demethylation was selectively inhibited by dimethylnitrosamine and chlorzoxazone (> 50%) and weakly inhibited by tolbutamide (12%) and fluconazole (22%), whereas other inhibitors showed no effect. This result suggested that TMO metabolism to DMO is mainly mediated by CYP2E1 and marginally by CYP2C and CYP3A4. 2. Fifteen human livers were screened and interindividual variability of TMO N-demethylation activity was 3-fold. Chlorzoxazone 6-hydroxylation activity was also measured and both activities were significantly correlated (r=0.735, p < 0.01). 3. DMO production by human cDNA expressed CYP enzymes was observed mainly for CYP2E1 (10.8 nmol/tube), marginally for CYP2C8 (0.22 nmol/tube) and not detectable for other CYP enzymes. 4. These results indicate that TMO metabolism is primarily catalysed by CYP2E1 and that trimethadione would be a suitable selective probe drug for the estimation of human CYP2E1 activity in vivo.

New sensitive method for the detection of the A3243G mutation of human mitochondrial deoxyribonucleic acid in diabetes mellitus patients by ligation-mediated polymerase chain reaction

An adenine-to-guanine mutation at nucleotide position (np) 3243 in the mitochondrial tRNALeu(UUR) gene is closely associated with various clinical phenotypes of diabetes mellitus. Because the mutation creates a new restriction site for the restriction enzyme ApaI, the mutation is usually detected and quantified by ApaI cleavage of the PCR products including np 3243. The sensitivity of the conventional method is, however, 5-10% heteroplasmy. The percentage of heteroplasmy of the mutation is usually highest in the affected tissues and is much lower in peripheral blood cells, which are used most frequently for the analysis. The sensitivity of the conventional method, however, is not sufficient to detect the mutation from peripheral blood cells. Utilizing ligation-mediated polymerase chain reaction, we have developed a feasible and sensitive method to detect 0.01% heteroplasmy of the 3243 mutation in peripheral leukocytes.