[A report of surgical treatment for atherosclerotic aneurysm in the aortic arch associated with type III acute aortic dissection]

A 75-year-old man was admitted to our hospital because of severe chest pain. A chest CT scan demonstrated an atherosclerotic true aneurysm measuring 50 mm in diameter located just distal to the aortic arch as well as a DeBakey type III dissection. Although the patient received medical therapy, the size of the true aortic aneurysm increased to 71 mm and the false lumen of the descending aorta was also enlarged after three weeks. At 11 weeks after admission, the aortic arch and the proximal portion of the descending aorta were replaced with a 32 mm Hemashield graft using moderate hypothermic selective cerebral perfusion. The postoperative course was uneventful, and there were no neurological complications. Coexistence of atherosclerotic true aneurysm and acute aortic dissection appears to increase the risk of aortic rupture, early surgical treatment should be considered.

[Molecular analysis of the estrogen receptor (ER) gene in association with ER negativity in breast cancer]

DNA from ninety-eight primary breast cancer biopsies has been examined for loss of heterozygosity (LOH). Thirteen of seventy-two informative cases (18.1%) were positive for LOH, which correlated with age at operation but not with ER status. This result suggests that LOH of the ER gene does not have an important role in the lack of ER function in breast cancer tissues. Thirteen breast cancers with ER negative/progesterone receptor (PgR) positive were screened for mutation analysis of the ER gene using single strand conformational polymorphism (SSCP). We found 2 polymorphisms in codon 10 (C to G) codon 325 (C to T), although neither germline nor somatic mutation was detected. Since the sequence variant of codon 325 tends to be more frequently seen in ER negative/PgR negative breast cancer patients than non-cancer control patients, it is suggested that this polymorphism was related to negativity and function of ER in breast cancer tissues.

Effects of calcium in continuous cardioplegia on myocardial protection

The effects of calcium (Ca) on a hyperkalemic cardioplegic solution for continuous cardioplegia were examined in an isolated perfused working rat heart model. The coronary arteries were perfused with a modified Krebs-Henseleit bicarbonate buffer (K-H) solution, containing various concentrations of Ca (0.1, 0.6, 1.2, and 2.5 mmol/l) and a high concentration of potassium (20 mmol/l), for 180 min, after which cardiac arrest was induced at 37 degrees C for 180 min. Cardiac function and creatine kinase (CK) were measured. In the control group, K-H solution was infused in place of the cardioplegic solution, and cardiac arrest was not induced. No significant differences were observed between the groups infused with the K-H solution containing Ca concentrations of 0.6, 1.2, and 2.5 mmol/l in the percent recovery of aortic flow (82.1 +/- 2.9%, 80.6 +/- 2.0%, and 71.5 +/- 3.7% (mean +/- SEM) respectively) or in the recovery of other indices of cardiac function, or in CK leakage. There were also no significant differences in the recovery of cardiac function and CK leakage between these groups and the control group. In the Ca 0.1 mmol/l group, however, the characteristic Ca paradox was observed. These findings suggest that if the Ca concentration in a cardioplegic solution is higher than 0.6 mmol/l during continuous cardioplegia, excellent cardioprotective effects will be achieved.

Cardiorespiratory function as assessed by exercise testing in patients with non-insulin-dependent diabetes mellitus

Exercise testing was used to examine 19 cardiorespiratory diabetes mellitus patients, aged 32-68 years (body mass index, 27.8 +/- 4.8 kg/m2), and 16 healthy volunteers, aged 23-57 years (body mass index, 22.7 +/- kg/m2). A graded cycling exercise test was done, monitoring gas exchange, ventilation and heart rate. Values were significantly higher in the non-insulin-dependent diabetes mellitus (NIDDM) patients than in the controls for fasting blood glucose (P < 0.01), glycosylated haemoglobin (P < 0.01), body weight (P < 0.05) and body mass index (P < 0.05). The exercise testing produced values that were significantly lower in the patients with NIDDM than in the controls for percentage oxygen uptake (P < 0.05), maximum load (P < 0.05), maximum metabolic equivalent (P < 0.01) and maximum oxygen uptake per unit body weight (P < 0.01). Ventilatory capacity and forced expiratory volume at 1 sec did not differ significantly in the two groups. These results suggest that general fitness is diminished due to reduced cardiorespiratory function in patients with NIDDM.

A study of malabsorption in pancreatic cancer

The type, incidence, and severity of malabsorption in patients with pancreatic cancer were investigated. The following absorption tests were performed; pancreatic function diagnostant (PFD) test, measurement of serum carotene levels, and 5 g D-xylose absorption test. Rates of abnormality in the tests were 75.7% of 37, 54.2% of 48, and 54% of 50 patients with pancreatic cancer, respectively. In particular, a marked decrease of values in the xylose absorption test was characteristic and more often recognized in patients with carcinoma of the pancreas with occlusion of the superior mesenteric vein. The presence of malabsorption (disturbed transport through the portal vein), in addition to maldigestion of nutrients, is suggested to induce severe malnutrition in patients with pancreatic cancer.

Antithrombotic effect of topically applied 3-oxa-methano-prostaglandin I1 in the microcirculation and antiplatelet functions of its active form

The antithrombotic effect of topical application of the 3-oxa-methano-prostaglandin (PG) I1 analog, SM-10902 in the microcirculation and in vitro antiplatelet functions of its active form SM-10906 were estimated in comparison with PGI2 and PGE1. In rat platelets, SM-10906 evoked accumulation of intracellular cyclic adenosine 3',5'-monophosphate, and exhibited antiaggregatory and disaggregatory activities, which were all enhanced by the phosphodiesterase inhibitor theophylline. Additionally, SM-10906 was shown to inhibit platelet adhesion to collagen in human platelet-rich plasma. PGI2 and PGE1 also showed in vitro antiplatelet effects in the order of PGI2 > SM-10906 > or = PGE1. SM-10902 exhibited a dose-dependent anti-thrombotic effect in the guinea pig mesenteric arteriole by a topical application, and this activity might be exerted by the antiplatelet functions of SM-10906. Although SM-10906, PGI2 and PGE1 also showed the antithrombotic effects, SM-10902 was the most potent. In conclusion, the present studies indicate that an external topical preparation of SM-10902 may be useful for the therapy of peripheral circulatory insufficiency.

Absorption of tea catechins into rat portal vein

Following the oral administration of tea catechins, (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate, respectively, to rats, the presence of these catechins in the portal blood was examined. It was confirmed by HPLC and mass spectrometry analysis that each of the administered catechins was present in the blood. These results clearly indicate that four predominant catechins in fresh tea leaves are absorbed, at least in part, into the rat portal vein.

Scavenging effects of tea catechins and their derivatives on 1,1-diphenyl-2-picrylhydrazyl radical

The scavenging effects of tea catechins and their epimerized, acylated, and glucostylated derivatives on 1,1-diphenyl-2-picrythydrazyl (DPPH) radical were evaluated by electron spin resonance spectrometry. Tea catechins and their epimers were shown to have 50% radical scavenging ability in the concentration range of 1 to 3 microM. No significant differences were observed between the scavenging activities of tea catechins and their epimers, and, hence, the scavenging effects of catechins are not dependent on their sterical structure. The relationship between scavenging ability and the structure of tea catechins was also examined with acylated and glucosylated catechin derivatives. It is suggested that the galloyl moiety attached to flavan-3-ol at 3 position has a strong scavenging ability on the DPPH radical as well as the ortho-trihydroxyl group in the B ring, which elevates the radical scavenging efficiency above that of the ortho-dihydroxyl group; as has been recognized in other flavonoids such as flavones. The results obtained from the reactivity of tea catechins with the DPPH radical at different pHs suggest not only that the ortho-trihydroxyl group and the galloyl moiety contribute to maintaining the DPPH radical scavenging ability more effectively in a wide range of conditions from acidic to alkaline, but also that the radical scavenging efficiency of the ortho-dihydroxyls in the B ring is limited in neutral to alkaline regions. The difference between the scavenging abilities of the trihydroxyls (probably in the galloyl moiety) and the dihydroxyls can be explained in terms of redox potentials. It is concluded that the ortho-trihydroxyl group in the B ring and the galloyl moiety at 3 position of flavan-3-ol skeleton are the most important structural features for displaying an excellent scavenging ability on the DPPH radical.

Demonstration of insulin resistance in coronary artery disease documented with angiography

OBJECTIVE

To evaluate the relation between insulin resistance and coronary atherosclerosis, insulin sensitivity in lean nondiabetic, normotensive subjects with and without obstructive coronary artery disease (CAD). The correlation between insulin resistance and degree of coronary stenosis was also investigated.

RESEARCH DESIGN AND METHODS

Four groups were studied: 1) nine subjects with normal glucose tolerance (NGT) without CAD, 2) 10 subjects with NGT with CAD, 3) nine subjects with impaired glucose tolerance (IGT) without CAD, and 4) 10 subjects with IGT with CAD. Insulin sensitivity was determined by the steady-state plasma glucose (SSPG) method using Sandostatin. Coronary angiography was performed in all study subjects, and the severity of coronary artery atherosclerosis was quantified in a modified Gensini score.

RESULTS

The SSPG (millimoles per liter) levels were significantly higher in the patients with CAD compared with control subjects (control vs. patient group: 4.8 +/- 0.5 vs. 7.9 +/- 0.9 with NGT, P < 0.05; 5.6 +/- 0.5 vs. 11.1 +/- 0.8 with IGT, P < 0.001), indicating the presence of insulin resistance in patients with CAD. The coronary atherosclerosis score (CAS) was significantly and positively correlated with SSPG (r = 0.74, P < 0.05) and 2-h insulin area (r = 0.78, P < 0.01) in NGT subjects with CAD. On the other hand, the percentage fall of plasma free fatty acid (0-30 min) during an insulin sensitivity test was significantly decreased in the subjects with CAD and was inversely correlated with the CAS (r = -0.43, P < 0.05), especially in NGT subjects with CAD.

CONCLUSIONS

These data suggest that in patients with CAD, insulin-mediated glucose metabolism is significantly impaired, and a significant correlation was noted between insulin resistance and severity of CAD. Therefore, the hyperinsulinemia often observed in patients with CAD is attributable to the compensatory mechanism of the beta-cell to the inadequate action of insulin for glucose metabolism. Hyperinsulinemia in the presence of insulin resistance aggravates dyslipidemia and may stimulate the atheromatous process by an as-yet-unknown mechanism.

Endothelin-1 partially inhibits ATP-sensitive K+ current in guinea pig ventricular cells

To clarify the pathophysiological significance of endothelin (ET) in the ischemic myocardium, we examined the effect of endothelin-1 (ET-1) on the ATP-sensitive K+ current (IK.ATP) and compared it with that of ET-3 in guinea pig ventricular cells using conventional microelectrode and patch clamp techniques. In isolated guinea pig papillary muscles, ET-1 (30 nM) markedly increased developed tension (DT), with little influence on action potential duration (APD), whereas ET-3 at the same concentration failed to affect DT or APD. Both nicorandil (1 mM) and cromakalim (30 microM) markedly shortened APD and decreased DT in papillary muscles. ET-1, but not ET-3, partially reversed the nicorandil-induced decreases in APD and DT in a concentration-dependent manner. ET-1 also attenuated the cromakalim-induced decreases in APD and DT. In single ventricular myocytes, both nicorandil and cromakalim increased a steady-state outward current, which was sensitive to 1 microM glibenclamide, suggesting that these drugs activate IK.ATP. ET-1 (30 nM) significantly inhibited the IK.ATP, whereas ET-3 failed to affect it. The ET-1 induced inhibition of IK.ATP was abolished by BQ-485 (100 nM), an ETA receptor-selective antagonist. Neither the protein kinase C (PKC) inhibitor staurosporine (20 nM) nor the calmodulin antagonist W-7 (50 microM) affected the inhibitory action of ET-1 on the nicorandil-induced IK.ATP. In pertussis toxin (PTX)-treated cells, the inhibitory action of ET-1 on IK.ATP was augmented rather than attenuated. These results suggest that ET-1 partially inhibits the IK.ATP through the activation of ETA receptors, although the precise intracellular mechanism remains to be clarified. Because activation of the ATP-sensitive K+ channels is considered to protect the ischemic myocardium, the partial inhibition of IK.ATP by ET-1 may lead to the aggravation of myocardial injury, potentially due to an increase in transmembrane Ca2+ influx.

The T/ebp null mouse: thyroid-specific enhancer-binding protein is essential for the organogenesis of the thyroid, lung, ventral forebrain, and pituitary

The thyroid-specific enhancer-binding protein (T/ebp) gene was disrupted by homologous recombination in embryonic stem cells to generate mice lacking T/EBP expression. Heterozygous animals developed normally, whereas mice homozygous for the disrupted gene were born dead and lacked the lung parenchyma. Instead, they had a rudimentary bronchial tree associated with an abnormal epithelium in their pleural cavities. Furthermore, the homozygous mice had no thyroid gland but had a normal parathyroid. In addition, extensive defects were found in the brain of the homozygous mice, especially in the ventral region of the forebrain. The entire pituitary, including the anterior, intermediate, and posterior pituitary, was also missing. In situ hybridization showed that the T/ebp gene is expressed in the normal thyroid, lung bronchial epithelium, and specific areas of the forebrain during early embryogenesis. These results establish that the expression of T/EBP, a transcription factor known to control thyroid-specific gene transcription, is also essential for organogenesis of the thyroid, lung, ventral forebrain, and pituitary.

Enhanced cellular proliferative activity and cell death in chronic thyroiditis and thyroid papillary carcinoma

For the analysis of cellular proliferative activity and cell death in thyroid diseases, the Ki-67 labeling index, bcl-2 protein expression and cell death of follicular epithelia by immunohistochemistry and in situ DNA nick-end labeling methods were evaluated in normal thyroid tissues as well as in surgical specimens from cases of Hashimoto's disease (16 cases), focal lymphocytic thyroiditis (13 cases), Graves' disease (15 cases), follicular adenoma (20 cases) and papillary carcinoma (43 cases). Cellular proliferative activity and cell death were both enhanced in cases of thyroiditis, including Hashimoto's disease and focal lymphocytic thyroiditis. Thyroids from patients with follicular adenoma and papillary carcinoma also showed increased cellular proliferative activity and cell death. In addition, predominant high cellularity and partial loss of bcl-2 protein expression in papillary carcinoma suggested that the overgrowth and dedifferentiation were associated with malignancy.

Interaction of class III antiarrhythmic drugs with muscarinic M2 and M3 receptors: radioligand binding and functional studies

We have recently reported that class III antiarrhythmic drugs inhibit the muscarinic acetylcholine (ACh) receptor-operated K+ current (IK,ACh) in guinea-pig atrial cells by different molecular mechanisms. The data obtained from the patch-clamp study suggest that D,L-sotalol inhibits IK,ACh by blocking the muscarinic receptors, whereas MS-551 inhibits the K+ current by blocking the muscarinic receptors and depressing the function of the K+ channel itself and/or the guanine nucleotide-binding protein (G protein). This study was undertaken to determine whether the class III antiarrhythmic drugs D,L-sotalol and MS-551 interact with the muscarinic receptors of cardiac and peripheral tissues. Both drugs inhibited concentration dependently the specific [3H]N-methylscopolamine ([3H]-NMS) binding to membrane preparations obtained from guinea-pig atria and submandibular glands. The competition curves of these drugs for [3H]-NMS binding to glandular membranes were monophasic, suggesting competition with [3H]-NMS at a single site. Although the competition curve of D,L-sotalol for [3H]-NMS binding to atrial membranes was monophasic, that of MS-551 was biphasic and showed high- and low-affinity states of binding. D,L-Sotalol showed slightly, but significantly, higher affinity for cardiac-type muscarinic receptors (M2) than for glandular-type muscarinic receptors (M3). The inhibition constant (Ki) for MS-551 in glandular membranes was also slightly greater than the high-affinity Ki value for the drug in atrial membranes. In guinea-pig left atria and ilea, D,L-sotalol shifted the concentration-response curves for the negative inotropic effect and the contracting effect of carbachol in a parallel manner. The slopes of Schild plot were not significantly different from unity, suggesting competitive antagonism, and the pA2 for D,L-sotalol in left atria was slightly greater than that in ilea. MS-551 also shifted the concentration response curve for the negative inotropic effect of carbachol in atrial preparations to a greater extent than that for the contracting effect in ileal preparations, although MS-551 failed to show a pure competitive antagonism. These results suggest that both D,L-sotalol and MS-551 interact with cardiac M2 and peripheral M3 receptors, and that at high concentrations they exert anticholinergic activity in cardiac and peripheral tissues.

Association of chronic lymphocytic thyroiditis and thyroid papillary carcinoma. A study of surgical cases among Japanese, and white and African Americans

BACKGROUND

An association between lymphocytic thyroiditis and thyroid papillary carcinoma is still controversial. To determine a definite statistical relation, a histopathologic study was performed on tissues from in three races, because there is a racial and age-related difference in the susceptibility to thyroiditis.

METHODS

The prevalence and severity of thyroiditis combined with adenomatous goiter, follicular adenoma, or papillary carcinoma was defined by examination of surgically resected materials from Japanese (626 patients), and white and African Americans (330 and 90 patients, respectively).

RESULTS

The prevalence of lymphocytic infiltrates, which are indicative of autoimmune thyroiditis, was significantly higher in patients with papillary carcinoma than in patients with adenomatous goiter or follicular adenoma among Japanese females (63.0%) and males (50.0%), white females (76.0%), and African American females (46.2%). Lymphocyte infiltration into the follicular adenoma or papillary carcinoma correlated with the severity of combined thyroiditis.

CONCLUSION

An association between chronic lymphocytic thyroiditis and papillary carcinoma was confirmed in the Japanese, and white and African American populations. The possibility of autoimmune thyroiditis as a predisposing factor for papillary thyroid carcinoma, is suggested.

[Analysis of 4 cases of intralobar pulmonary sequestration]

Four cases with pulmonary sequestration treated in Tottori university hospital between January 1993 and December 1994 were reported. Case 1 was a 63-year-old male who had lung tumor without inflammatory findings. Differential diagnosis from lung cancer was needed, and aortography showed a aberrant artery from descending aorta. Pulmonary partial resection and division of aberrant artery were performed. Case 2 was a 71-year-old female who diagnosed pulmonary sequestration in other hospital 10 years ago. Tumor shadow did not progress compared with the old X-ray film. Because tumor size was remarkably diminished by aspiration of cystic tumor, conservative follow up was continued. Both case 3 and 4 were a 20-year-old man and 16-year-old female who had typical findings of pulmonary sequestration with inflammation and easily detection of aberrant artery by CT or aortography. Resection of sequestrated lung and division of aberrant arteries were performed in both cases. Pulmonary sequestration was the disease which should be always kept in our mind in differential diagnosis from various lung disease.

Premedication with famotidine augments core hypothermia during general anesthesia

BACKGROUND

Animal studies have provided considerable evidence to support a role of histamine in the central nervous system in thermoregulation, and premedication with a histamine H2 receptor antagonist before general anesthesia is used to reduce the risk of acid aspiration. The authors investigated whether premedication with famotidine had an effect on thermoregulation during general anesthesia.

METHODS

In a randomized, placebo-controlled study, 30 ASA physical status 1 or 2 patients, scheduled for open abdominal surgery, were given either placebo or 40 mg oral famotidine 3 h before induction of anesthesia. Epidural buprenorphine (4 micrograms/kg) was injected, and anesthesia was maintained with 0.4-0.6% isoflurane and 66% nitrous oxide in oxygen. The tympanic membrane temperature was measured to assess core temperature, and forearm-fingertip and calf-toe skin-surface temperature gradients were used to assess peripheral vasoconstriction. Tympanic membrane temperature triggering initial vasoconstriction (a skin temperature gradient of 0 degree C) identified the vasoconstriction threshold.

RESULTS

Tympanic membrane temperature during surgery in the patients premedicated with famotidine was significantly less than those in the patients without famotidine. Famotidine significantly reduced the thermoregulatory threshold for vasoconstriction in the leg (35.0 +/- 0.5 degree C, P < 0.05), compared to that in the placebo group (36.4 +/- 0.6 degree C) Once triggered, thermoregulatory vasoconstriction produced a core-temperature plateau and no further hypothermia was observed for the duration of the study. Neither mean arterial pressure nor heart rate were significantly different between the two groups.

CONCLUSIONS

Premedication with famotidine augments intraoperative hypothermia. The mechanism appears to be inhibition of centrally mediated thermoregulatory control.

SD-3212, a new class I and IV antiarrhythmic drug: a potent inhibitor of the muscarinic acetylcholine-receptor-operated potassium current in guinea-pig atrial cells

1. By use of patch-clamp techniques, the effects of SD-3212, a novel antiarrhythmic drug, on the calcium current (Ica), the sodium current (INa) and the muscarinic acetylcholine-receptor-operated potassium current (IK.ACh) were examined and compared with those of bepridil in guinea-pig single atrial cells. 2. SD-3212 inhibited ICa and INa in a concentration-dependent manner. The IC50 values of SD-3212 for inhibition of ICa and INa were 1.29 microM and 3.92 microM, respectively. The steady state inactivation curves of ICa and INa were shifted in the hyperpolarizing direction in the presence of 1 microM SD-3212. Similar inhibition of ICa and INa was also observed with bepridil. The IC50 values of bepridil for depression of ICa and INa were 1.55 microM and 4.43 microM, respectively. 3. The muscarinic acetylcholine-receptor-operated potassium current (IK.ACh) was activated by the extracellular application of 1 microM carbachol in the GTP-loaded cells or by the intracellular loading of GTP gamma S, a nonhydrolysable GTP analogue. SD-3212 potently inhibited the carbachol- and GTP gamma S-induced IK.ACh and the IC50 values were 0.38 microM and 0.20 microM, respectively. These IC50 values were very close and about 10 times lower than those for inhibiting ICa and INa. Bepridil also suppressed the carbachol- and GTP gamma S-induced IK.ACh with the IC50 values of 0.69 microM and 0.84 microM, respectively. 4. In guinea-pig atrial cells stimulated at 0.2 Hz, carbachol at a concentration of 1 microM markedly shortened action potential duration. Both SD-3212 (0.1-1 microM) and bepridil (1-10 microM) reversed the action potential shortening in a concentration-dependent manner. The antagonizing effect of SD-3212 on the carbachol-induced action potential shortening was more potent than that of bepridil. 5. These results suggest that SD-3212 inhibits IK.ACh by depressing the function of the potassium channel itself and/or associated GTP-binding proteins. SD-3212 is a unique antiarrhythmic drug, which potently inhibits IK.Ach in addition to its class I and IV effects. SD-3212 and bepridil may be useful for the termination and prevention of vagally-induced atrial flutter and fibrillation.

[Hearing results after anterior tympanotomy in cholesteatoma surgery]

Between 1987 and 1993, 71 ears of attic type cholesteatoma and 20 ears of adhesive type were operated on using the intact canal wall technique combined with anterior tympanotomy. Pre- and postoperative pure tone hearing after the surgery were analyzed, especially to determine whether anterior tympanotomy is harmful to the inner ear. Mean values of 500, 1000 and 2000Hz of air conduction threshold immediately, before and about 1 year after the operation were compared. In attic cholesteatoma, type 1, type 3, and type 4 of ossiculoplasty revealed significant improvement of 8.4dB, 9.3dB, and 8.0dB respectively. In adhesive cholesteatoma, results obtained were 8.4dB, 0.8dB, and -3.0dB. Differences between pre- and postoperative bone conduction threshold at 4000Hz were 1.5dB in type 1, 1.3dB in type 3, and 5.0dB in type 4 in attic cholesteatoma. Those in adhesive cholesteatoma were -2.5dB, -0.2dB, and -10.0dB respectively. From the results obtained, we concluded that (1) our results were satisfactory with regards to hearing ability following all types of ossiculoplasty in attic cholesteatoma and in type 1 in adhesive cholesteatoma, (2) anterior tympanotomy itself is not a harmful procedure to the inner ear in both types of cholesteatoma, (3) an increase in bone threshold in adhesive cholesteatoma is due to the surgical procedure at the stapes and/or the oval window.

[Influence of aging upon changes in symptoms and cardiac size associated with surgical repair of atrial septal defect in adults]

To elucidate the influence of aging upon the improvement of symptoms and cardiac size associated with surgical repair of atrial septal defect, clinical symptoms, cardiothoracic ratio and hemodynamic variables in older patients (group A; age at operation > or = 50 years old, n = 11) were compared with those in younger patients (group B; age at operation < 50 years old, n = 8). There were no differences in hemodynamic variables, i.e., peak systolic pulmonary pressure, pulmonary to systolic flow ratio (Qp/Qs), pulmonary to systolic vascular resistance ratio (Rp/Rs) and left to right shunt ratio between the two groups. Symptomatic benefits occurred in all patients, although 3 patients in group A who had atrial fibrillation preoperatively still displayed symptoms such as exertional dyspnea. The postoperative (after 3 months) cardiothoracic ratio improved in all patients except for 3 patients in group A who were operated at over 60 years of age. Although there was no significant difference in preoperative cardiothoracic ratio between the two groups, the postoperative cardiothoracic ratio in group B was significantly smaller than that in group A. These results indicate that operative closure of atrial septal defect is recommended for all patients aged 50 years old or older, but early improvement of symptoms and cardiomegaly in older patients is lower than that in younger patients.

[Epidemiological study of tsutsugamushi disease in Gunma prefecture. A special field study and serotype]

An epidemiologically investigated of invasion of Rickettsia tsutsugamushi, inhabitant of mites and serum sample from patients with Tsutsugamushi disease in Gunma prefecture from 1984 to 1994 was made. Our data clearly indicated that Rickettsia tsutsugamushi was not located but widely spreaded throughout the Prefecture. Mites on rodents, were classified into 4 genus and 12 species and about 15% of them were Leptotrombidium pallidum and Leptotrombidium scuttellare, well known virulent vectors. The highest incidence rate of this disease was observed in the northwest area of the Prefecture from October to December, while a smaller number of patients occurred in other areas and in other months. About fifty percent of the serum samples from the patients were positive to the Karp strain. These results suggest that the major cause of this disease is the Karp strain and the disease could occur potentially in various areas of the Prefecture.

[Glomerular lesion in patients with type II mixed cryoglobulinemia having antibodies to hepatitis C virus]

We report here two cases of mixed cryoglobulinemia showing renal involvement associated with hepatitis C virus (HCV) infection. The subjects were 62- and 63-year-old males. Both patients presented with purpura on the legs, which was diagnosed as allergic vasculitis by skin biopsy. Case 1 followed a clinical course of progressive nephrotic syndrome with mild hematuria. He also had diabetes mellitus and hypertension. In contrast, case 2 showed only mild hematuria without proteinuria at the time of the renal biopsy. Both cases had immunological disarrangements, such as severe hypocomplimentemia and seropositive rheumatic factor. Recently, it was reported that patients with type II mixed cryoglobulinemia had HCV seropositivity, and revealed membranoproliferative glomerulonephritis. These facts strongly suggested that renal lesions are the result of direct damage mediated by cryoglobulinemia and an activated complement pathway through an immune complex mechanism related to HCV.

[Appearance of antibacterial activity of oxacillin against methicillin resistant Staphylococcus aureus (MRSA) in the presence of catechin]

We previously reported that tea catechin shows bactericidal activity against various bacteria including methicillin resistant Staphylococcus aureus (MRSA) and that bactericidal catechin damages the lipid bilayer of bacterial cell membranes. Here we describe that oxacillin (MPIPC) shows antibacterial activity against MRSA in the presence of catechin below MIC. Twenty clinical isolates of MRSA were examined by a cup method. In the absence of catechin, MPIPC even at a concentration of 40 micrograms/ml did not show antibacterial activity against all isolates of MRSA. However, when catechin below MIC (25-100 micrograms/ml) was mixed with the agar medium, MPIPC (5-12.5 micrograms/ml) showed antibacterial activity against all MRSA isolates. By counting the numbers of viable bacteria in a broth culture, only MPIPC (5 micrograms/ml) or catechin (100 micrograms/ml) showed similar growth curves to the control. But addition of both MPIPC and catechin reduced the number of viable bacteria to 1/100-1/10000 after 24 hours of cultures. Besides MPIPC, in the presence of catechin below MIC methicillin (12.5 micrograms/ml), aminobenzylpenicillin (32 micrograms/ml), tetracycline (2.5 micrograms/ml), and chloramphenicol (12.5 micrograms/ml) showed antibacterial activities against multiple drug resistant MRSA to antibiotics mentioned above. These findings suggest a possible use of catechin in the treatment of MRSA infection.

Hyperbetalipoproteinemia with small low-density lipoprotein, a characteristic disorder of lipoprotein in essential hypertension

The purpose of the present study was to elucidate the characteristic lipoprotein disorder in essential hypertension. Twenty-six patients with essential hypertension (HT) but without diabetes mellitus or obesity and 24 healthy subjects (control) were recruited into this study. Lipoproteins of HT and controls were separated by ultracentrifugation to very-low-density lipoprotein (VLDL), intermediate density lipoprotein (IDL), low-density liproprotein (LDL), and (HDL) fractions. Cholesterol and triglycerides were determined with enzyme assay, and apoB were determined by highly sensitive latex agglutination (Kyowa-hakko Co. LD). There was no difference in age (mean +/- SE; HT, 63 +/- 2 versus control, 60 +/- 2 years) or body-mass index (22.7 +/- 0.4 versus 21.7 +/- 0.5 kg/m2) between HT and controls. Blood pressure in HT and controls was 158 +/- 2/87 +/- 12 mm Hg and 123 +/- 3/72 +/- 2 mm Hg, respectively. Cholesterol did not change significantly in plasma (192.1 +/- 7.0 versus 176.4 +/- 4.2 mg/dL), VLDL (15.2 +/- 2.4 versus 11.8 +/- 1.7 mg/dL), IDL (14.8 +/- 2.4 versus 10.7 +/- 1.6 mg/dL), LDL (93.7 +/- 4.6 versus 83.1 +/- 3.9 mg/dL), nor in HDL (51.9 +/- 2.7 versus 58.1 +/- 3.2 mg/dL). Triglycerides (TG) increased in plasma (120.0 +/- 10.0 versus 87.5 +/- 9.3 mg/dL, p < 0.05), although TG did not change in all subfractions. ApoB increased in plasma (105.5 +/- 5.1 versus 85.6 +/- 3.6 mg/dL, p < 0.01), IDL (9.0 +/- 1.3 versus 5.4 +/- 0.6 mg/dL, p < 0.05), and LDL (76.3 +/- 4.3 versus 59.4 +/- 3.7 mg/dL, p < 0.01) in HT compared with controls. The ratio of cholesterol to apoB in LDL decreased (1.27 +/- 0.06 versus 1.48 +/- 0.08, p < 0.05). In essential HT, number of apoB containing lipoproteins (IDL, LDL) increased. Low ratio of cholesterol to apoB was noted in LDL, indicating the presence of small, dense LDL. As cholesterol in LDL was normal, hyperbetalipoproteinemia is also a characteristic disorder of essential HT.

Insulin resistance associated with compensatory hyperinsulinemia as an independent risk factor for vasospastic angina

BACKGROUND

It is generally believed that coronary artery spasm plays an important role in the progression of obstructive coronary artery disease. Since insulin resistance together with hyperinsulinemia plays an important role in the pathogenesis of coronary atherosclerosis, we investigated the association of hyperinsulinemia and insulin resistance with vasospastic angina (VAP).

METHODS AND RESULTS

The study population consisted of 60 patients with VAP and 42 control subjects (62 subjects with normal glucose tolerance and 40 with impaired glucose tolerance). Insulin sensitivity was determined by the steady-state plasma glucose (SSPG) method for nondiabetic, normotensive, nonobese subjects (16 control subjects, 16 obstructive coronary artery disease patients, and 16 VAP patients). Compared with the control group, the 2-hour insulin area (area under the plasma insulin concentration-time curve) during a 75-g oral glucose tolerance test was significantly higher in both VAP groups with normal and impaired glucose tolerance. A high frequency of vasospastic angina was observed in subjects with clustered risk factors for insulin resistance syndrome, suggesting a close association of VAP with this syndrome. In stepwise discriminant analysis, the 2-hour insulin area was significantly associated with VAP independent of other risk factors. SSPG level in VAP was about twofold over control, indicating the presence of insulin resistance in patients with VAP. However, no differences were found between patients with VAP and obstructive coronary artery disease with respect to mean SSPG level.

CONCLUSIONS

SSPG level was significantly elevated in patients with VAP and obstructive coronary artery disease compared with control subjects. This indicates that hyperinsulinemia is secondary to insulin resistance, both of which are thought to play important roles as risk factors for VAP in the early atheromatous lesion and in the future development of occlusive lesions when chronically present.