Comparison of bone mineral content among Japanese, Koreans, and Taiwanese assessed by dual-photon absorptiometry

Throughout the world the diagnosis and management of osteoporosis currently involves the measurement of bone mineral content. There are, however, no studies comparing bone mineral content among Asian people. This cross-sectional study was designed to quantify spine and femur bone mineral density (BMD) in Japanese and compare BMD among Asian people (Japanese, Koreans, and Taiwanese) using the same model dual-photon system (Norland Model 2600). Following a peak BMD in the third and fourth decades, the Japanese BMD values of the lumbar spine and femoral neck showed a clear decrease (annual loss of 0.99 and 0.74%, respectively) with age in females. On the other hand, Japanese BMD values were stable in males until the fifth decade. There was some decrease in BMD with age after the fifth decade, which was much less obvious than that in females. An age-dependent loss of BMD was clearly observed in Japanese and Korean but not in Taiwanese females. Korean males seemed to have a clearer age-dependent loss of BMD compared to Japanese males. Our findings indicate that differences may exist in the BMD of Asian people and that in addition to the quantitative determination of individual BMD, dual-photon absorptiometry may be useful for the comparison of BMD among different ethnic and cultural groups.

Role of sympathovagal interaction in diurnal variation of QT interval

To elucidate the role of sympathovagal interaction in diurnal variation of QT interval, 24-hour ambulatory electrocardiographic recordings from 56 subjects (23 control subjects, 18 patients with atherosclerotic coronary artery disease, and 15 patients with diabetes mellitus) were studied. The QT interval at a heart rate of 60 beats/min (QT60) was determined for each of the day and night periods by regression analysis. Sympathetic and parasympathetic activities were assessed by spectral analysis of heart rate variability and represented by the low- and high-frequency components, respectively. The proportion of high-frequency component to the sum of low- and high-frequency components was used as an index of sympathovagal balance. The relative increase in QT60 at night (delta QT60 [%]) was larger in control subjects (4.2 +/- 2.1%) than in patients with coronary artery disease (2.2 +/- 1.8%; p less than 0.01) and diabetes mellitus (-1.5 +/- 4.0%; p less than 0.001). When the data from the 3 subject groups were pooled and analyzed, delta QT60 was correlated with the change in the sympathovagal balance (r = 0.554; p less than 0.001). Low-frequency component in the day alone was also related with delta QT60 (r = 0.554; p less than 0.001), but the ratio or difference of the high-frequency component value between day and night was not. These results indicate that although change in sympathovagal balance was responsible for the diurnal variation in QT interval, the enhanced sympathetic activity in the day was a major determinant of this phenomenon.

[Coronary artery bypass grafting using retrograde continuous cold blood cardioplegia]

Coronary artery bypass grafting was performed in 166 patients with severe coronary artery disease using retrograde continuous cold blood cardioplegia (RC-CBCP) during the last 3 years and 8 months. In this study, myocardial protection was assessed from the aspect of enzymatic analyses and clinical results of these patients. Six hospital deaths were not related to the myocardial protection. Even in the groups of patients with medically refractory unstable angina, multiple occlusion of the coronary artery, low cardiac function and left main trunk lesion, RC-CBCP provided excellent protection of the myocardium and satisfactory results of operation as well as in each control group. Consequently we conclude that RC-CBCP affords safer and more effective myocardial protection in patients with severe coronary artery disease.

Left ventricular performance in patients with thermal injury or multiple trauma: a clinical study with echocardiography

Left ventricular (LV) contractile and diastolic performance was evaluated in patients with thermal injury or multiple trauma using precordial and transesophageal echocardiography. Thirty-nine patients were divided into four groups: group B1 (within 24 hours after thermal injury); group B2 (from 24 to 72 hours after thermal injury); group M (multiple trauma); and a control group (outpatients). Left ventricular contractile indices, including ejection fraction, mean velocity of circumferential fiber shortening, and the ratio of systolic blood pressure to LV end-systolic dimension, were not impaired in any of the experimental groups. The ratio of LV filling volume during rapid filling to stroke volume, obtained from M-mode echocardiography as an index of LV distensibility, was significantly decreased in groups B1 (44.5% +/- 8.8%) and B2 (46.8% +/- 8.5%) compared with controls (61.9% +/- 7.4%) (p less than 0.05). The ratio of the peak velocity in the atrial contraction phase to that in the rapid filling phase, obtained using pulsed Doppler echocardiography, also showed significant impairment of LV distensibility in groups B1 (1.08 +/- 0.12) and B2 (1.09 +/- 0.07) compared with controls (0.71 +/- 0.12) (p less than 0.01). Group M showed no significant impairment of these diastolic indices. A profound depression of LV diastolic function thus occurs following thermal injury but not following multiple trauma.

[Clinical and hemodynamic sequelae of mitral prostheses evaluated by Doppler echocardiography]

To determine the relative superiority of a prosthesis in the mitral position, in vivo hemodynamics were examined by Doppler echocardiography, and the results were compared with other types of mechanical mitral valves including 63 Björk-Shiley convexo-concave (BS) values, 30 Duromedics (DM) valves, and 58 Medtronic Hall (MH) valves. For this comparison, the following indices were evaluated: peak velocity of mitral flow (PV), mitral valve orifice area (MVA), mitral valvular regurgitation, New York Heart Association (NYHA) classification, pulmonary capillary wedge pressure (PC), cardiac index (CI) and valve-related complications. On Doppler echocardiograms, PV ranged from 1.2 to 2.0 m/sec with a mean of 1.6 m/sec. There was no evident relationship between the PV and the valve size in each type of prosthesis, and no significant difference in the PVs among the valves. The mean MVA was 2.6 cm2 (25 mm DM, 25 mm MH), which was regarded satisfactory from a clinical standpoint. MVA increased with the increase in the valve size in all types of valves, and of all sizes, MVA was larger in the DM and MH groups than in the BS group. Similarly, the incidence of valvular regurgitation was relatively low in all groups, and the degree of regurgitation proved to be grade II or less in all cases. As for the clinical results, clinical symptoms (NYHA) and hemodynamic states (PC, CI) improved postoperatively, with the differences among the types of prosthetic valves being insignificant. The incidences of thromboembolism, valvular thrombosis, valve failure and prosthetic endocarditis were relatively low in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)

A biphasic effect of noradrenaline on renin release from rat juxtaglomerular cells in vitro is mediated by alpha 1- and beta-adrenoceptors

The direct effect of noradrenaline on renin release from juxtaglomerular (JG) cells in vitro were investigated in a dynamic superfusion system of dispersed rat renal cortical cells. At low concentrations (1-100 nmol/l), noradrenaline stimulated renin release in a dose-dependent manner, while at higher concentrations (0.1-1 mmol/l) it inhibited renin release. The stimulatory effect of 0.1 mumol noradrenaline/l was completely blocked by a beta-adrenoceptor antagonist, propranolol (0.1 mumol/l). When applied at concentrations of 1 mumol/l or 10 mumol/l, noradrenaline had no consistent effect on renin release, although 10 mumol noradrenaline/l had an inhibitory effect in the presence of propranolol (0.1 mumol/l). The inhibitory effect of noradrenaline (0.1 mmol/l) was converted to a stimulatory effect by the addition of an alpha 1-adrenoceptor antagonist (bunazosin, 1 mumol/l), but was not altered by the addition of an alpha 2-adrenoceptor antagonist (yohimbine, 1 mumol/l). These results indicate that low concentrations of noradrenaline directly stimulate renin release from JG cells by the activation of beta-adrenoceptors, while high concentrations of noradrenaline inhibit renin release by the activation of alpha 1-adrenoceptors. Accordingly, a dynamic balance may exist between beta-adrenergic stimulation and alpha 1-adrenergic depression of renin release.

Genetic Analysis of Dilated Cardiomyopathy. HLA and immunoglobulin genes may confer susceptibility

To identify genetic factors in the immune system which control the susceptibility to dilated cardiomyopathy (DCM), HLA class II DNA typing was performed in 61 Japanese patients, using PCR/SSO probe analyses. The frequencies of HLA-DQB1*0503 (15% vs 5%; RR = 3.06, chi 2 = 7.19) and DQB1*0604 (21% vs 10%; RR = 2.41, chi 2 = 6.20) were significantly increased and that of HLA-DQB1*0502 (RR = 1.74) was slightly increased in the DCM patients. The frequency of DQB1*0303 (16% vs 31%; RR = 0.44, chi 2 = 5.16) was significantly decreased in the patients. The increased HLA-DQB1 alleles have a histidine residue in common at the 30th codon for the HLA-DQ beta chain. Among the genetic markers studied by Southern blot analyses, IGLV (immunoglobulin lambda light chain, pV3.3) showed a strong association with DCM, i.e. A2/A2 genotype was found in 37.7% of patients whereas it was observed in only 18.9% of the control subjects (RR = 2.6, chi 2 = 7.77). The frequency of this genotype was higher in patients under age 45 years at the time of diagnosis (45.5%, RR = 3.6, chi 2 = 10.02). These results suggest that HLA and immunoglobulin genes are closely linked to susceptibility to DCM.

Islet amyloid polypeptide (IAPP) gene analysis in a Japanese diabetic with marked islet amyloid deposition

Islet amyloid polypeptide (IAPP) is a major constituent of pancreatic amyloid deposits in many patients with non-insulin-dependent diabetes mellitus (NIDDM). We analyzed the IAPP gene in a Japanese diabetic with marked islet amyloid deposition. Pancreatic specimens were obtained from an 87-year-old NIDDM patient who had had diabetes for 37 years. All islets (100/100) in his pancreas had IAPP-positive amyloid deposition, and 70% of the area of the islet was replaced by amyloid. We amplified the coding regions as well as the upstream region of the IAPP gene by polymerase chain reaction (PCR). The products of PCR were sequenced, and the sequences of the coding regions were identical to the Caucasian ones. However, the nucleotides of two positions of 5'-upstream and one position of intron 2 were different from the Caucasian data: the upstream region of the IAPP gene in the patient had cytosine substituted for thymine at -259, and had two alleles including cytosine and adenine at -229, respectively. The nucleotide of position 539, that is guanine, was deleted. A possible difference in the IAPP promoting region between the Japanese and Caucasian population was suggested.

Effect of elevated extracellular calcium on the proliferation of osteoblastic MC3T3-E1 cells:its direct and indirect effects via monocytes

There has been evidence that elevated calcium concentration at the resorptive site of the bone directly regulates osteoclast function. In the present study, in order to clarify the role of elevated calcium concentration at the resorptive site in the regulation of osteoblast function, not only direct but also indirect effect via human monocytes of the increase in extracellular calcium (Cae) on the proliferation of osteoblastic MC3T3-E1 cells have been investigated in serum-free condition. The increase in Cae enormously stimulated osteoblast proliferation at the concentration of 3 to 20 mM. When human monocytes were cultured at the elevated Cae concentration, monocyte-conditioned medium-induced stimulation of osteoblast proliferation was significantly amplified. Present data demonstrate that elevated Cae has pronounced stimulatory effect on osteoblast proliferation not only directly but also indirectly via monocytes. Calcium released from bone matrix at the resorptive sites might be linked to the coupling of osteoclast and osteoblast functions.

Antioxidant defenses of cultured gastric cells against oxygen metabolites: role of GSH redox cycle and endogenous catalase

Gastric mucous epithelial cells may represent a first line of defense against reactive oxygen species that are generated within the gastric lumen. However, little is known about their defenses against oxidant species. This study examined the importance of the glutathione (GSH) redox cycle and of endogenous catalase as antioxidant defenses in cultured gastric mucous cells. Cultured rat gastric mucous cells were exposed to H2O2 generated by glucose oxidase acting on glucose or to nascent H2O2 for 5 h. Cytotoxicity was quantified by measuring 51Cr release from prelabeled cells. The effects of inhibition of the GSH redox cycle and of endogenous catalase were examined. Glucose oxidase caused a dose-dependent increase of 51Cr release. Similarly, nascent H2O2 damaged the cells dose dependently. Pretreatment with 1,3-bis(chloroethyl)-1-nitrourea (inhibitor of GSH reductase) dose dependently increased glucose oxidase-induced 51Cr release. Preincubation with buthionine sulfoximine (inhibitor of gamma-glutamyl-cysteine synthetase), which lowered intracellular GSH content, enhanced glucose oxidase-induced damage in a dose-dependent manner. Pretreatment with diethyl maleate, which covalently binds GSH as catalyzed by GSH transferase, also enhanced the sensitivity to lysis by glucose oxidase. However, inhibition of endogenous catalase activity by 3-amino-1,2,4-triazole did not significantly alter glucose oxidase- or nascent H2O2-induced 51Cr release. These results suggest that the GSH redox cycle rather than endogenous catalase plays a critical role in intracellular antioxidant defense in cultured gastric mucous cells.

[Results of Kock pouch construction fully utilizing an auto-suture instrument]

From March 1987 to the end of February 1991, we performed Koch pouch construction as a urinary diversion on 20 patients who had undergone radical cystectomy due to bladder cancer. The operation was done according to the method of Skinner et al. We fully utilized an auto-suture instrument to ensure safe and stable suturing of the ileum and to shorten the operating time. It was of great concern that the staples placed at several portions might cause stone formation or aggravate infection. However, stone formation was observed only in one patient (5%) at the tip of a nipple valve in which a staple became the nucleus of the stone. Staples are usually not regarded as an obstacle as they are usually covered by the mucous membrane. In all patients, the maximum capacity of the pouch was more than 500 ml, intra-pouch pressure was kept low even when the pouch was inflated up to the maximum capacity, and reflux of urine into the upper urinary tract was not observed. As for complications, there was a slight degree of obstructive uropathy in 4 patients (20%), difficulty in catheter insertion was noted in 3 patients (15%), and stress incontinence-like urinary leakage was present in one patient when the capacity exceeded 500 ml. However, there were no complications which necessitated reoperation. In terms of blood chemistry, although there was a tendency towards a slight increase in BUN or hyperchloremia, no specific treatment was necessary as far as the kidney function was normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Caroli's disease: scintigraphic and radiographic findings

Caroli's disease is a rare congenital anomaly of the liver. Since new diagnostic techniques for the evaluation of hepatic disease have been introduced, the number of reported cases of Caroli's disease has been gradually increasing. This report describes the case of a 13 year old girl with nausea, vomiting, fever and hepatomegaly. The diagnosis of Caroli's disease was established by ultrasonography and CT scan. The complications and management are discussed. The important points in management are to relieve symptoms and to conduct regular examinations by ultrasonography for the early detection of hepatobiliary carcinoma.

Effect of dietary protein restriction on proteinuria in non-insulin-dependent diabetic patients with nephropathy

To determine the effectiveness of dietary protein restriction on proteinuria in patients with non-insulin dependent diabetes (NIDDM), 14 diabetic patients with overt nephropathy were placed on either a low protein diet (N = 7) or conventional protein diet (N = 7) for one month. After the study period, daily urinary protein excretion rates decreased significantly, from 3.2 +/- 0.4 to 1.9 +/- 0.4 g/day, and serum albumin levels increased from 3.3 +/- 0.2 to 3.7 +/- 0.5 g/dl only in the low protein diet group, without any significant changes in either serum creatinine levels or creatinine clearance. These findings suggest that dietary protein restriction has a beneficial role in the treatment of NIDDM patients with overt nephropathy.

Effects of calcitonin gene-related peptide on membrane currents in mammalian cardiac myocytes

We examined the effects of calcitonin gene-related peptide (CGRP) on the membrane currents of single atrial and ventricular cells of guinea pig heart. The tight-seal whole-cell voltage-clamp technique was used. In atrial cells, like isoproterenol, CGRP increased the L-type Ca channel current (ICa.L) in a concentration-dependent manner. Human CGRP-(8-37), a putative CGRP receptor antagonist, completely abolished the CGRP-induced increase of ICa.L. Although the effects of CGRP were similar to those of isoproterenol, propranolol, a beta-adrenergic receptor antagonist, did not affect the CGRP-induced increase of ICa.L. After ICa.L had been maximally activated by isoproterenol (2 microM) or intracellular cyclic adenosine 5'-monophosphate (100 microM), CGRP failed to increase ICa.L. Acetylcholine antagonized the effects of CGRP on ICa.L. Unlike the effects on atrial cells, CGRP had no significant effects on the membrane currents of ventricular myocytes. These results indicate that CGRP increases ICa.L via adenylate cyclase activation by binding to specific membrane receptors in cardiac atrial myocytes. Furthermore, CGRP receptors are expressed in atrial cells but probably not in ventricular cells.

[Clinical studies on 3 pairs of monozygotic twin sisters affected by Graves' disease]

Clinical studies were undertaken of three pairs of monozygotic twin sisters affected by Graves' disease. The evidence that the twins were monozygotic was established by similarity in physical appearance, identical blood-group antigens and identical HLA types. All pairs were female, and the evidence of Graves' disease in both members of the pair was observed in 2 out of 3 pairs. In the remaining pair the disease started in the elder sister, but the younger sister still remained in euthyroidism in spite of the presence of diffuse goiter. The disease occurred in the second decade in all the patients, and the interval between the occurrence of the disease in twin sisters was 1 to 4 years. No common specific type of HLA was found among all three pairs, but DR4 was common in two pairs of twin sisters showing positive MCHA test. Serum TRAb was positive in 2 pairs of twin sisters but negative in the remaining one. However, it became positive in the elder sister of the latter pair during the antithyroid treatment. The effect of antithyroid drug treatment was found to be similar in each of the twin sisters, and the serum TRAb moved almost in parallel with serum FT4 level. These results indicate that a genetic factor may be of great importance in the aetiology of Graves' disease, and there was a strong preponderance for it to occur in women and the second decade was the peak age for its occurrence. The common specific type of HLA for all Graves' patients was not found in this study. A strong relationship was observed between Grave's disease and TRAb.

Growth-dependent alterations of intracellular Ca(2+)-handling mechanisms of vascular smooth muscle cells. PDGF negatively regulates functional expression of voltage-dependent, IP3-mediated, and CA(2+)-induced Ca2+ release channels

To examine the alterations of intracellular Ca2+ ([Ca2+]i)-handling mechanisms in cultured vascular smooth muscle cells (VSMCs) of rat aorta (Shin et al Circ Res 1991;69:551-556), we stimulated VSMCs by extracellular high K+, caffeine, and angiotensin II and evaluated Ca2+ influx through voltage-dependent Ca2+ channels, Ca(2+)-induced Ca2+ release, and inositol trisphosphate-dependent Ca2+ release from internal stores. Percentage of VSMCs responding to each stimulant (responder ratio) and degree of [Ca2+]i increase in the responding cells were analyzed by a two-dimensional fura-2 imaging system. The responder ratios to the three stimulants were high (70-90%) in the quiescent phase (days 1-2), although some cells selectively responded to one or two of the stimulants. Responder ratios prominently decreased to approximately 20% in the proliferating phase (days 2.5-3). In the subconfluent (days 3.5-4) and postconfluent (days 5-6) phases, the responder ratio to high K+ and angiotensin II recovered to the same level as during the quiescent phase, whereas that to caffeine remained low (approximately 10-20%). In responding cells, the degree of [Ca2+]i increase by caffeine and angiotensin II was stable (approximately 100%) during culturing, whereas that to high K+ was small (approximately 30-40%) in the quiescent and proliferating phases and rapidly increased threefold in the subconfluent and postconfluent phases. Furthermore, arrest of cell growth in serum-free medium prevented the reduction of responder ratios in the proliferating phase and restored the decreased ratio of the caffeine responder. Acceleration of VSMC proliferation by platelet-derived growth factor decreased the ratios in all phases. These results imply that 1) the functional expressions of [Ca2+]i-handling mechanisms in response to these vasoactive stimuli are influenced by cell growth and cytodifferentiation of VSMCs or platelet-derived growth factor and 2) they are regulated independently from each other.