Decrease in serum levels of thyroid hormone in patients with coronary heart disease

The aim of this study was to evaluate the relationship between subclinical hypothyroidism and/or autoimmune thyroid disease and coronary heart disease (CHD). Ninety seven patients diagnosed as having CHD by a coronary angiography (CHD group) and 103 healthy subjects matched for age, sex and body mass index (control group) were included in the study. Thyroid function, thyroid autoantibodies and serum lipid concentrations were measured in the CHD and control groups. The CHD group exhibited significantly decreased serum free T3 (FT3) and free T4 (FT4) levels, and significantly increased serum TSH levels as compared with the control group, indicating a significant decrease in thyroid function in the CHD patients. Serum high density lipoprotein cholesterol (HDL-C) levels were significantly decreased in the CHD group. The incidence of subclinical hypothyroidism and thyroid autoantibodies was similar in both two groups. These observations were also true of women even after those who had diabetes mellitus (DM), hypertension (HT) and a smoking habit were excluded. This was not the case, however, in men without DM, HT, or a smoking habit. Patients with CHD had significantly lower serum levels of HDL-C than the control subjects, regardless of gender (P < 0.01). In the group with CHD, there was no difference between the serum lipid levels in patients with subclinical hypothyroidism and those with normal thyroid function. Female patients with CHD had significantly lower serum levels of thyroid hormone and HDL-C, but their subclinical hypothyroidism or thyroid autoimmunity did not seem to be related to the development of CHD.

[The role of nicotinic receptor in memory impairment: a study using event-related potentials and midlatency responses]

To evaluate the efficacy of chronic nicotine administration in dementia, electrical field distributions of event-related potentials (ERPs) and midlatency response (MLR) were recorded and were analyzed in terms of time and space. The study was carried out on 22 normal individuals and 17 patients with dementia (vascular dementia, Alzheimer disease and Parkinson disease). Nicotine was delivered transdermally from a nicotine patch (22.5 to 52 mg/day) for 2 or 4 weeks. Dementing patients showed abnormal ERPs in latency, amplitude and electrical field on the scalp. Decreased amplitude and electrical field abnormality of P1 in MLR was also seen in some patients with dementia. These abnormal ERPs and MLR of the patients improved after administration of nicotine especially in P300 latency of ERPs and P1 amplitude of MLR. These data suggest that nicotine administration might be useful as a cognitive enhancer in memory impairment.

Regional and cellular expression of the Machado-Joseph disease gene in brains of normal and affected individuals

Machado-Joseph disease (MJD) is an autosomal dominant disorder characterized pathologically by spinocerebellar degeneration. Recently, an expansion of CAG repeat in a gene located at the chromosome 14q32.1 was found to be responsible for the disease. Here, we investigated in situ the expression of the MJD gene (MJD1) in the central nervous systems of normal and affected individuals and in rat brains. This gene was expressed in all regions of rat and human normal brains with certain regional variations. MJD1 was transcribed preferentially in neurons, although low levels of MJD1 mRNA were also observed in glial cells. Neurons susceptible to degeneration in MJD expressed MJD1 but not selectively. In the affected brains, the MJD1 mRNA distribution and amount in all the areas examined were similar in patients and controls. In addition, the cellular MJD1 mRNA level correlated neither with clinical severity nor expanded length. Our study showed that the expression levels of trinucleotide repeats in MJD patients and normal controls did not differ, indicating that the pathogenesis of MJD may involve direct toxicity to vulnerable subsets and/or region-specific cofactors of MJD proteins.

Scleroderma-polymyositis overlap syndrome associated with anti-Ku antibody and rimmed vacuole formation

Scleroderma-polymyositis overlap syndrome is strongly associated with certain autoantibodies, such as anti-PM-Scl antibody and anti-Ku antibody. We describe a case of scleroderma-polymyositis overlap syndrome associated with anti-Ku antibody, which revealed rimmed vacuole formation in addition to intranuclear and intracytoplasmic filamentous inclusions in muscle biopsy specimens.

A comparison of the hypotensive and hypoglycaemic actions of an angiotensin converting enzyme inhibitor, an AT1a antagonist and troglitazone

OBJECTIVE

To define the relationship between changes in insulin sensitivity and attenuation of hypertension.

METHODS

We investigated whether troglitazone (CS-045, an insulin sensitizer) has an antihypertensive effect in fructose (FRU)-fed Wistar rats with insulin resistance and simultaneously compared its hypotensive efficacy with those of alacepril (ALA, an angiotensin converting enzyme inhibitor) and TCV-116 (an AT1a receptor antagonist). Male rats aged 8 weeks were divided into five groups: controls fed normal chow, a FRU group fed FRU-rich (55%) chow, a FRU plus ALA group fed 30 mg/kg ALA per day, a FRU plus TCV-116 group fed 1 mg/kg TCV-116 per day and a FRU plus CS-045 group fed 70 mg/kg CS-045 per day). After 8 weeks, the body weight and systolic blood pressure were recorded and glucose tolerance was determined by glucose loading (2 g/kg, intraperitoneally) and a steady-state plasma glucose (SSPG) method. The plasma membrane glucose transporter 4 content in gastrocneumius muscle was determined by Western blot analysis.

RESULTS

FRU increased blood pressure from 125 mmHg in controls to 141 mmHg (P < 0.01). ALA and TCV-116 administration decreased blood pressure to 111 and 107 mmHg, respectively (P < 0.01). CS-045 administration lowered blood pressure significantly to 121 mmHg. Area under the curve levels for plasma insulin during glucose loading increased from 1.7 in controls to 3.6 ng/ml x h in FRU-fed rats, but were lowered by the three drugs. SSPG levels increased from 12.5 in controls to 18.3 mmol/l in FRU-fed rats (P < 0.01), but were decreased by ALA and TCV-116 administration (P < 0.01). CS-045 administration also lowered SSPG levels to 15.3 mmol/l (P < 0.05). FRU-feeding induced a 1.24-fold increase in plasma membrane glucose transporter 4, which was not affected by ALA and TCV-116 administration, but was augmented 1.82-fold by CS-045 administration. Furthermore, the increased triglyceride level after FRU was diminished both by ALA and by CS-045 administration.

CONCLUSION

These results suggest that, in the insulin-resistant state, troglitazone, an angiotensin converting enzyme inhibitor and an AT1a receptor antagonist show comparable hypotensive and hypoglycaemic effects.

[The impaired glucose tolerance in the pathogenesis of dyslipidemia]

It is well known that hyperlipidemia is often present in patient with impaired glucose tolerance, obesity and/or hypertension. All of these are risk factors for coronary artery disease (CAD). The coexistence of these risk factors markedly increase the likelihood of CAD. Recently, it has been reported that the impaired glucose tolerance and insulin resistence are associated with the increased proinsulin, which is linked to the risk of CAD. We review that the impaired glucose tolerance is an important factor causing dyslipidemia. The characteristic of dyslipidemia associated with the impaired glucose tolerance include hypertriglyceridemia, high level of VLDL and low level of HDL cholesterol. They also associate with accumulation of remnant lipoproteins and appearance of small dense LDL. In addition, we pointed out that the increased number of risk factors is associated with elevated insulin and proinsulin level.

[A case of Dyke-Davidoff-Masson syndrome with total hemiatrophy]

We reported a 39-year-old man with Dyke-Davidoff-Masson syndrome presenting with total hemiatrophy. The patient had a muscle defect in the left occipital lesion at birth and left hemiatrophy including the face in his infancy. The present illness consists of atrophy of the left face, trunk and extremities, a muscle defect accompanied with scleroderma of the left dorsal cervical lesion, bilateral pes cavus, cleft palate, left hemiparesis, including facial palsy and diminished superficial sensation of the left side of the body. Decrease in right cranial volume and slight elevation of the right temporal pyramid and the superior border of the orbit were seen on the X-ray study of the head. Atrophy of the right cerebrum and cerebral peduncle was seen on magnetic resonance imaging. These findings suggest that hemiatrophy of the brain was responsible for total hemiatrophy of the body in this patient. The etiology of cerebral hemiatrophy is not known. There is only a report of Dyke-Davidoff-Masson syndrome accompanied with total hemiatrophy.

LDL apheresis reduces the susceptibility of LDL to in vitro oxidation in a diabetic patient with hemodialysis treatment

OBJECTIVE

We studied whether LDL apheresis would alter the susceptibility of LDL to in vitro oxidative modification induced by copper ion in a diabetic patient undergoing hemodialysis treatment.

RESEARCH DESIGN AND METHODS

Isolated LDL was dialyzed against phosphate-buffered saline and resuspended at a concentration of 0.3 mg cholesterol mass/ml buffer LDL oxidation was then initiated by addition of 1.66 mumol/l CuSO4, and the formation of conjugated dienes was continuously monitored spectrophotometrically at 234 nm.

RESULTS

The duration of the lag phase of LDL obtained after LDL apheresis was markedly longer than that of LDL obtained before LDL apheresis. The propagation rate and the maximum conjugated diene formation of LDL oxidation were not changed after LDL apheresis.

CONCLUSIONS

A LDL subfraction that was susceptible to oxidation was removed by LDL apheresis, resulting in reduction of susceptibility of LDL to in vitro oxidation remaining in plasma. LDL apheresis may be of clinical importance for preventing atherosclerotic disease in diabetic patients undergoing hemodialysis.

Thyroid involvement by malignant histiocytosis of Langerhans' cell type

Involvement of the thyroid gland by Langerhans' cell histiocytosis is quite rare. We describe the case of a 58-year-old man referred for treatment of a progressively enlarging goitre. The trachea was severely stenotic and adjacent structures such as the left carotid vein and the thyroid cartilage were also involved. Central diabetes insipidus and severe combined immunodeficiency were associated. Although fine needle aspiration biopsy of the thyroid was initially interpreted as papillary carcinoma, anaplastic thyroid cancer was suspected. Treatment with prednisolone, doxorubicin and irradiation controlled the tracheal compression. A diagnosis of thyroid Langerhans' cell histiocytosis was finally made on the basis of the presence of Birbeck granules and CD1a and CD4 antigen in the thyroid tumour cells. Furthermore, positive staining for CD68 and lysozyme suggested that the tumour cells may have had the character of phagocytic cells in addition to their dendritic cell nature. This is the first case of thyroid involvement by malignant histiocytosis of Langerhans' cell type with unusual phagocytic markers.

An upstream activating sequence containing curved DNA involved in activation of the Clostridium perfringens plc promoter

The plc gene, which encodes phospholipase C (alpha-toxin) of Clostridium perfringens, possesses three poly(A) tracts forming an intrinsically curved DNA region immediately upstream of the promoter. The in vivo transcriptional activity of the plasmid-borne plc gene was stimulated by this curved-DNA-containing sequence, depending on its proper linear and rotational orientation. The in vitro transcriptional activity of the plc gene was also stimulated by the upstream sequence. In addition, the stimulatory effect of the sequence and the degree of DNA bending were greater at lower temperature, as was demonstrated by both in vitro and in vivo transcription assays, and a gel-mobility assay, respectively. A similar temperature effect was also observed with the chromosomal plc gene. These observations suggest that the upstream DNA curvature per se stimulates the initiation of transcription of the plc gene, possibly through direct contact with RNA polymerase.

Influence of mosaicism on sexing of human preembryos detected by the polymerase chain reaction

PURPOSE

Preimplantation sex determination using a single cell by the polymerase chain reaction (PCR) was investigated to elucidate the influence of mosaicism.

METHODS

The SRY and ZFX genes were coamplified as target sequences for the Y and X chromosomes, respectively. The sensitivity of the single and nested PCR method was examined initially followed by amplification of single amniocytes by the nested PCR. Then the sex of single blastomeres at the three- and nine-cell stages was determined by the nested PCR.

RESULTS

The nested PCR was 10(4)-fold more sensitive than the single PCR. Sex determination was possible in 97.5% (117/120) of the blastomeres tested. However, the correspondence rate for all blastomeres within a single embryo was only 60% (12/20 embryos). Among the remaining embryos for which sexing of all blastomeres was not consistent, only one blastomere showed findings indicating the presence of mosaicism (or pseudomosaicism).

CONCLUSIONS

At least two blastomeres need to be assessed when determining the sex of an embryo in order to avoid misdiagnosis due to mosaicism (or pseudomosaicism).

Genome mapping of Clostridium perfringens strains with I-CeuI shows many virulence genes to be plasmid-borne

The intron-encoded endonuclease I-CeuI from Chlamydomonas eugametos was shown to cleave the circular chromosomes of all Clostridium perfringens strains examined at single sites in the rRNA operons, thereby generating ten fragments suitable for the rapid mapping of virulence genes by pulsed-field gel electrophoresis (PFGE). This method easily distinguishes between plasmid and chromosomal localisations, as I-CeuI only cuts chromosomal DNA. Using this approach, the genes for three of the four typing toxins, beta, epsilon, and tau, in addition to the enterotoxin and lambda-toxin genes, were shown to be plasmid-borne. In a minority of strains, associated with food poisoning, where the enterotoxin toxin gene was located on the chromosome, genes for two of the minor toxins, theta and mu, were missing.

Bradykinin may not be involved in improvement of insulin resistance by angiotensin converting enzyme inhibitor

We have previously demonstrated that captopril ameliorates glucose intolerance by partially preventing the reduction in postprandial skeletal muscle blood flow. The present study was designed to clarify the mechanism by which ACE inhibitors affect glucose metabolism in fructose (FRU)-fed Wistar rats with hypertension, glucose intolerance and hyperinsulinemia. Eight-week-old male rats (n = 51) were divided into six groups. Controls were given a normal chow, while fructose-rich (55%) chow was administered to the remainder for eight weeks. The different groups were administered alacepril (ALA, 30 mg/kg/day) with or without a continuous infusion of Hoe 140, a kinin B2 receptor antagonist (150 micrograms/kg/day), Hoe 140 alone or TCV-116 (1 mg/kg/day), an angiotensin II receptor antagonist, alone. After measuring the body weight and systolic blood pressure (BP), steady-state plasma glucose (SSPG) levels were determined. FRU significantly increased BP from 141 mmHg in controls to 156 mmHg. ALA with or without Hoe 140 decreased BP to 124 mmHg or 117 mmHg, respectively, but Hoe 140 alone did not affect BP. TCV-116 also decreased BP to 116 mmHg. The SSPG levels increased from 7.58 mM in controls to 8.98 mM in FRU-fed rats. This was lowered with both ALA and TCV-116. Hoe 140 alone, however, did not affect SSPG levels. Hoe 140 did not show any effects on ALA-induced improvement of SSPG. These results suggest that the improvement in glucose tolerance observed with ACE inhibitors is not due to the kinins, and angiotensin II receptor antagonists also improve insulin sensitivity.

Genetic analysis of the sam mutations, which induce sexual development with no requirement for nutritional starvation in fission yeast

The cAMP pathway and the Ras pathway are the two major pathways to sexual development in the fission yeast Schizosaccharomyces pombe. To understand the cAMP pathway or the related pathway, we analyzed mutants that display a phenotype similar to cyr1-, that is, hyper-sporulation. Nine mutants termed sam (sporulation abnormal mutant), which are highly inclined to sexual development despite the presence of nitrogen sources, were partially characterized. Cyclic AMP was detected in all nine sam mutant cells, and over-expression of the adenylyl cyclase gene (cyr1) failed to suppress the hyper-sporulation phenotype of these sam mutants, suggesting that none of the sam mutants were likely to be allelic to cyr1. Epistatic tests of sam mutants showed that they were divided into two dominant and seven recessive mutants. Dominants were able to make spores in sam/sam+ heterodiploid cells upon abundant nutrients. Both two dominant mutants bypassed the inability to make spores in ras1 deficient diploid cells, suppressed the deficiency to execute sporulation in byr2 deficient diploid cells, but failed to suppress the byr1 deficiency. Two dominant mutations seem not to occur within the byr2 gene.

[Tactile extinction following the cerebral sinus thrombosis. A study using event-related potentials]

We reported a 46-year-old woman in whom cerebral sinus thrombosis manifested itself in headache and weakness while she was on an oral estrogen preparation. The neurological examinations revealed monoparesis of the right upper extremity, hyperactive right deep tendon reflex and disturbance of the joint sense, stereognostic sense, two-point discrimination and skin writing sense in the right upper extremity, in addition to tactile extinction. Brain CT showed empty triangle sign. MRI revealed infarction near the left postcentral gyrus and thrombosis of right sigmoid sinus. In the MRA study, there was low signal intensity in the posterior portion of the superior sagittal sinus and right transverse sinus. Short latency SEP in upper extremity showed that the central conduction time was normal, while the amplitude of wave components after N20 was reduced on the right side. Both palms were given bilateral or unilateral pressure stimuli. When event-related potentials (ERP) were evoked, using bilateral stimuli as a rare target, and left unilateral stimuli as a non-target, the P 300 latency was prolonged to 450 msec but was restored to normal with the improvement of tactile extinction. These results seem to suggest that the tactile extinction is ascribable to a disturbance of recognition at the higher brain function level and that ERP can be a useful objective yardstick in the evaluation of extinction phenomenon.

A variant of adenomatous goiter with characteristic histology and possible hereditary thyroglobulin abnormality

A variant type of adenomatous goiter was identified in 24 of 2160 patients with adenomatous goiter who underwent thyroidectomy. The characteristics of the thyroid gland in these 24 patients included large goiter, small follicles, scant colloid, and columnar follicular cells containing yellow-green granules on hematoxylin-eosin staining. The thyroid gland was slightly orange-red, and electron microscopic examination showed abundant lysosomes with colloid droplets. When comparing the features of this group with those of 24 patients with common adenomatous goiter, the incidence of familial predisposition to thyroid diseases in the former group was higher. The age at the time of detection of goiter was lower, i.e. 17 +/- 15 vs. 44 +/- 17 yr (P < 0.001, variant type vs. common type), the serum total T4 concentrations were lower (84 +/- 21 vs. 103 +/- 18 nmol/L; P < 0.01), and the serum TSH concentrations were higher (2.4 +/- 2.1 vs. 1.0 +/- 0.9 mU/L; P < 0.01). Thyroid radioiodine uptake was remarkably increased (49 +/- 22 vs. 16 +/- 9%; P < 0.001), and lower levels of serum thyroglobulin were noted (33 +/- 51 vs. 484 +/- 603 micrograms/L; P < 0.01). The thyroglobulin content was low in the thyroid gland studied. The data suggest that the etiology of this variant type of goiter is a hereditary abnormality in thyroglobulin synthesis, and this type of goiter may be distinguished from common adenomatous goiter by the characteristic morphology of the thyroid gland in addition to clinical findings.

Wide reconstruction of the anterior cranial base with bipedicled galeopericranial flap

BACKGROUND

Reconstruction of facial bone fractures complicated by frontal sinus destruction must seal off the cranial cavity from the upper respiratory tract to avoid ascending infections of the intracranial contents.

METHODS

We used a bipedicled galeopericranial flap for reconstruction of the extradural and subcutaneous spaces of the frontal region, which were infected with methicillin-resistant Staphylococcus aureus (MRSA) following unsuccessful coverage of the anterior cranial base with an anteriorly based pericranial flap.

RESULTS

The patient healed uneventfully without infection.

CONCLUSION

Because a bipedicled galeopericranial flap has abundant blood supply, it can be used to cover a wide segment of the anterior cranial base. This is the first report of the application of a bipedicled galeopericranial flap for wide reconstruction of the anterior cranial base.

Analysis of the phospholipase C gene of Clostridium perfringens KZ1340 isolated from Antarctic soil

Clostridium perfringens KZ1340 isolated from Antarctic soil was first classified as Clostridium plagarum and later as a lecithinase-negative variant of C. perfringens. Although the strain produced no detectable lecithinase (phospholipase C, PLC) activity in the culture supernatant, it was shown by Southern blot hybridization to possess a PLC-encoding gene (plc). To determine the cause of the PLC deficiency, we cloned and sequenced the plc gene from KZ1340. The deduced amino acid sequence consists of 398 amino acid residues, coinciding with those of the plc genes previously determined. Tyrosine was substituted for histidine at amino acid position 148, which is thought to bind a zinc ion essential for PLC activity. Northern blot analysis revealed that KZ1340 expressed the plc gene at an extremely low level. Furthermore, the plc gene cloned from C. perfringens strain 13 into a plasmid was expressed weakly in KZ1340, compared to that in strain 13. This indicates that the former strain represses plc gene expression in trans. When a phylogenetic tree of plc genes was constructed, the KZ1340 plc gene formed a monophyletic branch along with those of various other C. perfringens strains, supporting the classification of the strain as a variant of C. perfringens.

A higher proinsulin response to glucose loading predicts deteriorating fasting plasma glucose and worsening to diabetes in subjects with impaired glucose tolerance

To evaluate the clinical significance of proinsulin determination, we measured glucose, insulin, C-peptide and proinsulin during 75-g oral glucose loading in 59 patients. In a 2.5-year follow-up study of 37 subjects with impaired glucose tolerance (IGT) at the initial test, 11 patients changed from IGT to a normal state and 5 patients showed worsening to overt Type 2 diabetes with elevation of fasting plasma glucose; 21 patients remained unchanged. Although our data showed that both fasting (IGT: p = 0.4523) and 120-min plasma glucose (IGT: p = 0.8168) values at the initial test were not significantly correlated with increased fasting plasma glucose levels in a 2.5-year follow-up study, subjects with a higher 120-min proinsulin response to glucose during the initial OGTT showed a significant correlation (IGT: p < 0.0001) with increased fasting plasma glucose levels after follow-up period and developed Type 2 diabetes. The present findings suggest that the proinsulin response to glucose loading might be a useful indicator for predicting worsening to diabetes in subjects with impaired glucose tolerance.

Metformin decreases blood pressure and obesity in OLETF rats via improvement of insulin resistance

To determine whether improvement of insulin resistance decreases blood pressure as well as obesity, metformin (100 mg/kg/d) or vehicle was administered for 20 weeks to 12-week-old male Otsuka Long-Evans Tokushima Fatty (OLETF) rats (n = 10 each), a newly developed animal model of non-insulin-dependent diabetes mellitus (NIDDM) with mild obesity, hyperinsulinemia, and hypertriglyceridemia. Oral administration of metformin ameliorated glucose intolerance and attenuated the insulin response to glucose loading (2 g/kg, i.p.), as evidenced by a decrease in the area under the curve for glucose and insulin at 24 weeks by 19% and 37%, respectively. At 21 weeks, systolic blood pressure was significantly lower in the metformin group than in controls (130 +/- 1.9 vs. 143 +/- 2.7 mmHg, p < 0.01), despite no difference in body weight. Subsequently, blood pressure tended to be slightly but insignificantly lower in the metformin group, and body weight was significantly lower in the metformin group (532 +/- 9.8 vs. 587 +/- 10.3 g at 31 weeks, p < 0.01). Metformin treatment also lowered the level of serum triglycerides (9.4 +/- 0.6 vs. 13.2 +/- 0.5 mmol/l, p < 0.01) and the plasma norepinephrine concentration (4,222 +/- 373 vs. 7,548 +/- 1,058 pg/ml, p < 0.01). These results suggest that metformin-induced improvement of insulin resistance in obese rats with NIDDM may lower blood pressure, as well as decrease sympathetic activity and reduce body weight.

Pure autonomic failure with motor neuron disease: report of a clinical study and postmortem examination of a patient

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Electric field distribution of event-related potentials in stroke patients

Electrical field distributions of event-related potentials (ERP's) were recorded during an auditory "oddball paradigm" and were analyzed in terms of time and space. Fourteen normal subjects and 14 chronic patients were cerebral thrombosis were studied. For the components N1 and P3 of the ERP's to target stimuli, reference-independent measures (latency, global field power, location of maximal or minimal potential, and location of centroids) were determined. Stroke patients displayed P3 abnormalities in latency, amplitude, and electrical field on the scalp. In addition, N1 electrical fields were also abnormal. These ERP abnormalities correlated significantly with the extent of mental function impairment in the stroke patients, and they improved after administration of a cerebral metabolic enhancer (Nefiracetam: DM-9384). The ERP's seemed to be sensitive in indicating the effects of the drug. These data suggest that time-course analysis of the spatial distribution of the ERP electrical field might be useful for evaluation of the extent of mental function impairment and the efficacy of drugs.

Elevated erythrocyte sodium-lithium counter-transport in hypertensive patients with non-insulin-dependent diabetes mellitus

Increased erythrocyte (RBC) sodium-lithium (Na-Li) counter transport (CT) has been reported to be a genetic marker for essential hypertension (EHT). In addition, increased RBC Na-Li CT has been demonstrated in insulin-dependent diabetic (IDDM) patients with nephropathy, indicating that a predisposition to hypertension may cause renal damage and impaired renal function. Therefore, the present study was designed to determine RBC Na-Li CT in subjects with essential hypertension (EHT) and non-insulin-dependent diabetics (NIDDM) with or without hypertension (NIDDMHT or NIDDMNT), using the method of Canessa et al. with a slight modification by flame photometry and expressed as nmol Li/5 x 10(6) RBC/h. Na-Li CT in patients with EHT (0.159 +/- 0.051 (S.D.), n = 26) or NIDDMHT (0.168 +/0 0.083, n = 42) was higher than that in NIDDMNT patients (0.127 +/- 0.059, n = 27, P < 0.05). Among the NIDDMHT patients, those with clinical nephropathy had the same levels of Na-Li CT as those without nephropathy. When the NIDDM patients were divided into two groups with or without insulin treatment, the Na-Li CT in hypertensives was higher than that in normotensives, irrespective of whether or not they were on insulin therapy. Addition of insulin to RBCs in vitro did not augment the Na-Li CT activity. These results suggest that an increase of Na-Li CT may not be due to the stimulatory effect of endogenous or exogenous insulin, and reflect a genetic predisposition for hypertension, and hence diabetic nephropathy, not only in IDDM but also NIDDM patients.