Hisao Oguchi

A Study of Chronic Pancreatitis by Serial Endoscopic Pancreatography

The pancreatic duct system was studied with repeated endoscopic retrograde pancreatography in 31 patients with chronic pancreatitis, 32 patients with suspected chronic pancreatitis, and 16 controls without pancreatic disease. In chronic alcoholic pancreatitis the pancreatograms showed marked changes during the initial examination with progression even after abstinence or reduction of drinking. In the alcoholics with suspected chronic pancreatitis, progressive lesions in branch ducts with almost intact main ducts were recognized. In contrast, no remarkable alterations on serial pancreatograms were observed in nonalcoholic cases with definite or suspected chronic pancreatitis. These results suggest that pancreatic duct lesions play an important role in the development and progression of chronic alcoholic pancreatitis in contrast to chronic nonalcoholic pancreatitis.

Elevated serum levels of Dupan-2 in pancreatic cancer patients negative for Lewis blood group phenotype.

CA19-9, a serum marker for pancreatic cancer, gives false-negative results in patients who are negative for the Lewis blood group phenotype. To determine whether other markers may compensate for this drawback, serum levels of CA50, Span-1, sialyl SSEA-1 and Dupan-2 were assayed and compared with those of CA19-9 in 207 normal subjects and in 200 patients with pancreatic carcinoma whose Lewis blood group phenotypes were confirmed. In normal subjects with the Lewis negative phenotype, the serum levels of CA50 and Span-1, as well as CA19-9, were significantly low, whereas those of sialyl SSEA-1 were independent of the Lewis blood group phenotype. Serum levels of Dupan-2 were significantly higher in normal subjects with the Le (a-b-) phenotype as compared with those with Le(a-b+). The sensitivity for pancreatic carcinoma was 81% for CA19-9, 84% for CA50, 82% for Span-1, 51% for sialyl SSEA-1 and 63% for Dupan-2. Among the 39 CA19-9 negative patients, 13 were determined as being Lewis negative by the serum dot-ELISA technique. Although the positive rates were essentially comparable when each marker was combined with CA19-9, a highly elevated serum level of Dupan-2, which strongly suggested the presence of malignancy, was most frequently encountered in 39 patients who were not diagnosed by CA19-9 assay, especially those with Lewis negative blood groups. With regard to the three other markers, we found few patients with a highly elevated serum level in either the Lewis-negative or -positive groups. We conclude that Dupan-2 tended to be elevated in patients with pancreatic cancer who were negative for the Lewis blood group phenotype.

Comparative study of CA242 and CA19-9 for the diagnosis of pancreatic cancer.

A comparative study of a new tumour marker, CA242, and CA19-9 was conducted with special reference to their diagnostic usefulness in pancreatic cancer. CA242 showed sensitivity similar to that of CA19-9 for overall cases and early cases (stage I tumour) of pancreatic cancer. For other malignancies, the positive rates of CA242 were lower than those of CA19-9 except for colorectal cancer. An important characteristics of CA242 was that it was only slightly and infrequently elevated in the sera of patients with benign diseases such as chronic pancreatitis, chronic hepatitis and liver cirrhosis. This characteristic was more apparent in the patients with benign obstructive jaundice, indicating that the serum level of this marker was scarcely affected by cholestasis. Using cut-off levels corresponding to a 90% specificity, the clinical results obtained with CA242 in the diagnosis of pancreatic cancer were similar to those obtained with CA19-9, except that CA19-9 was falsely negative in some patients with early-stage pancreatic cancer. These findings suggest the usefulness of this marker for screening pancreatic cancer in patients on their first hospital visit. However, CA242 was found to be influenced by the Lewis blood group system. This unfavourable result is attributed to the C241 catcher antibody of this assay system, which has almost the same epitope specificity as the C50 and the NS19-9 monoclonal antibodies. In conclusion, CA242 is superior to CA19-9 in diagnosing pancreatic cancer by virtue of its higher specificity.

Ultrastructural study of the glomerular slit diaphragm in fresh unfixed kidneys by a quick-freezing method

SummaryIn normal kidneys fixed by perfusion with tannic acid and glutaraldehyde, glomerular slit diaphragms have been reported to consist of highly ordered and isoporous substructures with a zipper-like configuration. We have re-evaluated the ultrastructure of fixed or unfixed glomeruli using quick-freezing and deep-etching (QF-DE) and freeze-substitution (QF-FS) methods. In the fixed slit diaphragms, zipper-like substructures were often observed by the QF-DE method. In contrast, in fresh unfixed glomeruli the slit diaphragms mainly consisted of non-porous substructures. The slit diaphragms were more widely opened in the fixed glomeruli, as examined by the QF-FS method. These results suggest that the foot processes shrink during tissue preparation by conventional methods with chemical fixatives, and that the broadening of slit diaphragms and zipper-like substructures are formed by the pulling apart of adjacent foot processes due to shrinkage.

Protective effect of vitamin E supplementation on increased thermal stability of collagen in diabetic rats

SummaryProducts similar to non-enzymatic glycation end products are known to arise from the interactions between proteins and lipid peroxides in vitro. In this study, we assessed the effect of vitamin E, which possibly modifies lipid peroxide, on advanced glycation end products or similar products in vivo by measuring the fluorescence and thermal rupture time of tail tendon collagen in streptozotocin-induced diabetic rats. The diabetic rats and non-diabetic rats were fed a vitamin E supplemented diet, and a control diet starting 3 days after the streptozotocin injection. After the 4-week treatment, the serum lipid peroxide levels expressed as thiobarbituric acid reactants in the diabetic rats on control diet (15.9 ± 2.6 μmol/l [SEM]) were significantly (p <0.05) higher than in the non-diabetic rats (7.9 ± 1.3 μmol/l on control diet and 3.3 ± 0.4 μmol/l on supplemented diet), but the levels in the diabetic rats on supplemented diet (7.9 + 2.3 μmol/l) were reduced to the normal levels. No significant differences were found in serum glucose and glycated haemoglobin levels within the diabetic rats on control and supplemented diets. Both the fluorescence and thermal rupture time of collagen were significantly (p <0.05) increased in the diabetic rats on both diets compared with those in the corresponding non-diabetic rats. Although there was no significant difference in the collagen-linked fluorescence within the diabetic rats on control and supplemented diets, the thermal rupture time was significantly (p <0.01) shortened with supplemented diet (10.8 ± 0.7 min on supplemented diet vs 15.0 ± 0.7 min on control diet). The effect of vitamin E on the thermal rupture time was not observed in non-diabetic rats (6.6 ± 0.5 min on supplemented diet vs 6.2 ± 0.5 min on control diet). These results indicate that the formation of advanced glycation end products or similar products seen in hyperglycaemia can be partially inhibited by vitamin E supplementation by lowering lipid peroxide levels or oxidative stress. This study is thought to be the first to show vitamin E as an anti-oxidant agent limiting the formation of advanced glycation end products or similar products in vivo.

Epitope analysis of SPan-1 and DUPAN-2 using synthesized glycoconjugates sialyllact-N-fucopentaose II and sialyllact-N-tetraose

Epitope analysis of Span-1 and DUPAN-2 was compared with that of CA19-9 using the synthesized glycoconjugate sialyllacto-N-fucopentaose II (SLF11, sialyl-Lewisc) and its precursor, sialyllact-N-tetraose (LSTa, sialyl-Lewis”), conjugated to human serum albumin. The CA19-9 and DUPAN-2 assay systems specifically recognized SLF II and LSTa, respectively. The Span-1 assay system recognized both SLF IIIand LSTa, although the reactivity with the former was far stronger than that with the latter. These results were, in general, compatible with those obtained from assaying these markers in the sera of two pancreatic cancer patients with definite Lewis-negative phenotype and in the sera of 39 CA19-9-negative pancreatic cancer patients. In conclusion, DUPAN-2 is the precursor of CA19-9 and is accumulated in the sera of pancreatic cancer patients with Lewis-negative phenotype and Span-1 has an advantage over CA19-9 in the diagnosis of patients with Lewis-negative phenotype, although both markers have almost the same sensitivity for this malignancy.

Stiffening of connective tissue in elderly diabetic patients : relevance to diabetic nephropathy and oxidative stress

SummaryLimited joint mobility seen in diabetes mellitus is thought to be the result of stiffening of periarticular connective tissue, which is presumably derived from increased crosslinking of collagen related to advanced glycation end products. In this study the extent of the stiffening of connective tissue was measured by the passive extension angle of the metacarpophalangeal joints in 205 elderly diabetic patients. Association with diabetic nephropathy, with which advanced glycation end products have recently been demonstrated to increase, and metabolic abnormalities were also considered. The angle of the metacarpophalangeal joints was significantly correlated with age (r=−0.24, p<0.01), and was significantly smaller in men than in women (p<0.01). The angle demonstrated a decrease in association with diabetic retinopathy and nephropathy, and only the association with nephropathy was significant (p<0.05). The angle was weakly, but significantly, correlated with serum thiobarbituric acid reactants as a measure of lipid peroxides (r=−0.15, p<0.05), triglyceride (r=−0.20, p<0.01) and HDL cholesterol (r=0.19, p<0.01), but not with blood glucose (r=0.02), HbA1c (r=0.06) or duration of diabetes (r=−0.05). In addition, the angle in 14 non-diabetic patients on haemodialysis was significantly (p<0.05) smaller than that in age- and sexmatched normal subjects. Thus, it was indicated that the stiffening of connective tissue was associated with diabetic nephropathy, serum lipid peroxide and dyslipidaemia. Stiffening of connective tissue seems to be more affected by oxidative stress than non-enzymatic glycation per se. Factors contributing to the stiffening of connective tissue, such as male sex, ageing, serum lipid peroxide, high triglyceride and low HDL cholesterol resemble those associated with arteriosclerosis.

Pharmacokinetics of Temocapril and Enalapril in Patients with Various Degrees of Renal Insufficiency

SummaryTemocapril is a novel ACE inhibitor that is cleared via dual excretion routes in humans. Borderline or mildly hypertensive patients with normal renal function [group 1, creatinine clearance (CLcr) >70 ml/min (4.2 L/h), n = 12], moderate renal impairment [group 2, CLcr 30 to 70 ml/min (1.8 to 4.2 L/h), n = 12] or severe renal impairment [group 3, CLcr <30 ml/min (1.8 L/h), n = 12] received a single oral dose of either temocapril 1mg (n = 6, each group) or enalapril 5mg (n = 6, each group).These 2 drugs gave similar values for the area under the plasma concentration-time curve (AUC) of the active diacids. The maximum plasma concentration of enalapril diacid was increased 2- and 6-fold in moderate and severe renal impairment, respectively, whereas that of temocapril diacid was not altered. The AUC of enalapril diacid increased 13-fold at CLcr values <30 ml/min, but that of temocapril diacid increased only 2-fold.The duration of plasma ACE inhibition due to enalapril was greatly prolonged by the impairment of renal function, whereas that due to temocapril was affected very little. Urinary recovery of temocapril diacid was decreased markedly in patients with severe renal dysfunction, most probably because the diacid was excreted through the biliary route. On the other hand, urinary recovery of enalapril diacid remained fairly high even in patients with severe renal impairment, because of extremely high plasma diacid concentrations resulting from the lack of biliary excretion. These observations suggest that temocapril is beneficial in the treatment of hypertension in patients with severely impaired renal function.

The Role of Oxygen Free Radicals in Experimental Acute Pancreatitis in the Rat

SummaryIn order to elucidate the role of oxygen-derived free radicals in acute pancreatitis, scavengers and an inhibitor of production of these free radicals were administered to rats with experimentally-induced acute pancreatitis. Acute reflux pancreatitis was produced by the occlusion of the common bile duct (OCD). Catalase and superoxide dismutase (SOD) were used as scavengers, and allopurinol was used as an inhibitor of production of free radicals. Six h after surgery, serum amylase, lipase, and thiobarbituric acid (TBA) reactant levels were elevated significantly, and histological changes in the pancreas, consisting of edema, inflammatory cell infiltration, and necrosis, partially around the intralobular and interlobular ducts, developed in the control rats receiving no agent. However, serum lipase and amylase levels in the rats given each agent were significantly lower (p<0.05) than in the controls. The histological changes in the pancreas were less marked in agent-treated rats than in untreated rats. These results suggest that oxygen-derived free radicals participate in the development of acute pancreatitis.

Prospective follow-up study of hepatitis C virus infection in patients undergoing maintenance haemodialysis: comparison among haemodialysis units.

A prospective follow‐up study on hepatitis C virus (HCV) infection was conducted in seven haemodialysis units from April 1990 to March 1995. A total of 634 patients were undergoing maintenance haemodialysis in the seven units. Of those, 302 patients participated in the follow‐up study; 179 were initially HCV antibody negative and 123 were initially positive. Nine of the 179 initially negative patients became positive for HCV antibody during the follow‐up period. In accordance with the appearance of HCV antibody, indicating new infection of HCV, all nine of these patients were diagnosed with HCV viraemia. As no other routes were apparent, HCV infection in all nine patients was likely due to nosocomial transmission. Prevalence of HCV antibody at the start of follow up was significantly higher (P < 0.001) in haemodialysis units A‐C (37.9%) than in haemodialysis units D‐G (17.0%). Incidence of new HCV infection was significantly higher (P= 0.005) in the former units (2.2% per year) than in the latter (0.2% per year). Ten of the 123 patients who were initially positive for the HCV antibody exhibited a loss of reactivity during the follow‐up period; of these 10 patients, nine were negative for HCV‐RNA from the start of the study. In conclusion, the incidence of new HCV infection seen in patients undergoing haemodialysis suggests that their risk of acquiring HCV infection is directly related to the prevalence of HCV antibody positive patients being treated in the units.