Search PubMed⌕ Search

Biomedical subjects

M Tominaga

Publications and source records attributed to M Tominaga.

At least 109 records · Page 6Linked to original sources
PubMed1999

Successful treatment of adult-onset Henoch-Schönlein purpura nephritis with high-dose immunoglobulins.

A 26-year-old woman was admitted for the evaluation of edema and massive proteinuria. She had a history of purpura of the lower extremities, abdominal pain and melena. Laboratory investigations showed hypoalbuminemia, hypercholesterolemia and proteinuria of over 10 g/day. Renal biopsy showed moderate proliferative glomerulonephritis with mesangial immunoglobulin A (IgA) deposition. She was diagnosed as having Henoch-Schonlein purpura nephritis. Oral prednisolone, dipyridamole and intravenous heparin treatment were not effective. Steroid pulse therapy induced a partial improvement of proteinuria to 2-3 g/day. High-dose intravenous immunoglobulin (i.v.-IG) treatment was introduced and a dramatic improvement of proteinuria was noted. I.v.-IG should be fully considered in patients with steroid-resistant Henoch-Schonlein purpura nephritis.

Adult↗
PubMed1999

Impaired glucose tolerance is a risk factor for cardiovascular disease, but not impaired fasting glucose. The Funagata Diabetes Study.

OBJECTIVE: To determine whether the new category of impaired fasting glucose (IFG) recently proposed by the Expert Committee of the American Diabetes Association is a risk factor for cardiovascular disease. RESEARCH DESIGN AND METHODS: Death certificates and residence transfer documents from the cohort population consisting of participants of the diabetes prevalence study in Funagata, Yamagata prefecture, Japan, 1990-1992, were analyzed up through the end of 1996. First, the cohort population was classified into three groups: normal glucose tolerance (NGT) (n = 2,016), impaired glucose tolerance (IGT) (n = 382), and diabetic (n = 253). Then the same population was reclassified into normal fasting glucose (NFG), IFG, and diabetic. The cumulative survival rates among the groups were compared using the classical life-table method, and age-adjusted analyses, the person-year method, and Cox's proportional hazard model were adopted. RESULTS: At the end of seven observed years, the cumulative survival rates from cardiovascular disease of IGT and diabetes were 0.962 and 0.954, respectively, both significantly lower than that of NGT (0.988). The Cox's proportional hazard model analysis showed that the hazard ratio of IGT to NGT on death from cardiovascular disease was 2.219 (95% CI 1.076-4.577). However, the cumulative survival rate of IFG from cardiovascular disease was 0.977, not significantly lower than that of NFG (0.985). The Cox's hazard ratio of IFG to NFG on death from cardiovascular disease was 1.136 (0.345-3.734), which was not significant either. CONCLUSIONS: IGT was a risk factor for cardiovascular disease, but IFG was not.

Aged↗
PubMed1999

Expression of CD40/CD40 ligand and Bcl-2 family proteins in labial salivary glands of patients with Sjögren's syndrome.

Lymphocytes infiltrating the salivary glands of patients with Sjögren's syndrome (SS) are activated and resist apoptosis. We determined the role of interactions between CD40 and CD40 ligand (CD40L) in these infiltrating lymphocytes on B-cell differentiation and expression of Bcl-2 family proteins. Ten human T-cell leukemia/lymphoma virus-I (HTLV-I)-seronegative and eight HTLV-I-seropositive SS patients were examined in the present study. Immunohistochemistry was performed to examine the expression of CD3, CD20, PCA-1, CD40, CD40L, Bcl-2, Bax, and Bcl-x on T and B lymphocytes infiltrating labial salivary glands of SS patients. We also examined the expression of CD40 and CD40L on peripheral blood lymphocytes of the same patients by using flow cytometry. CD40L was not expressed on peripheral blood lymphocytes of SS patients. Peripheral blood B cells but not T cells expressed CD40. In contrast, >50% of mononuclear cells, including T and B cells infiltrating the glands, expressed CD40. In addition, a clear expression of CD40L in both infiltrating T cells and B cells, and that of PCA-1, was also demonstrated. Surprisingly, the expression of Bcl-2 and Bcl-x was colocalized with that of CD40 determined by mirror section technique. Bcl-x was also abundantly expressed on infiltrating mononuclear cells, but, Bax expression was relatively less than that of Bcl-2 or Bcl-x. The expression of the above molecules was not different between HTLV-I-seronegative and HTLV-I-seropositive SS patients. Our results indicate that CD40/CD40L pathways could be augmented in salivary glands of SS patients, inducing B-cell differentiation to PCA-1 + plasma cells. Immunohistochemical analysis also suggests that signaling through CD40 by means of CD40L increases the expression of Bcl-2 as well as Bcl-x in infiltrating lymphocytes, providing the resistance against apoptosis. Our findings were commonly observed in SS patients irrespective of HTLV-I seropositivity.

Aged↗
PubMed1999

Mechanisms of action of OPC-28326, a selective hindlimb vasodilator.

The unique cardiovascular profile of OPC-28326 [4-(N-methyl-2-phenylethylamino)-1-(3, 5-dimethyl-4-propionylaminobenzoyl)piperidine hydrochloride monohydrate] provides insight into basic mechanisms of this new drug as determined by experiments in dogs and rats. In anesthetized open-chest dogs, an i.v. administration of a low dose (0.3 and 1.0 microg/kg) of OPC-28326 selectively increased femoral artery blood flow with only minimal action on systemic blood pressure, heart rate and coronary, carotid, vertebral, renal, and mesenteric blood flows. Biochemical study suggests that OPC-28326 had no effect on phosphodiesterase-3 and -5. OPC-28326 dose-dependently inhibited phenylephrine-induced increases in blood pressure in spinally anesthetized dogs. The potency of OPC-28326 was, however, about 180 times lower than that of prazosin. Although binding studies have revealed an affinity of OPC-28326 to serotonin 5-HT(2) receptors, the drug is without effect, except at very high concentrations, on serotonin-induced contraction in an isolated canine femoral artery preparation. The potency of OPC-28326 on the increase in femoral artery blood flow was about 14 times higher than that of prazosin but was at about the same level as that obtained with yohimbine in canine autoperfused femoral artery preparations. In perfused rat hindlimb preparations, OPC-28326 inhibited the decrease in perfusion flow induced by brimonidine, a selective alpha(2)-adrenoceptor agonist. The potency of OPC-28326 was at least 10 times less than that of yohimbine. Taken together, the results show that at low doses, OPC-28326 selectively exerts a potent vasodilating effect on the femoral arterial bed, in part due to an alpha(2)-adrenoceptor-blocking activity.

Adrenergic Antagonists↗
PubMed1999

[Diagnostic criteria for diabetes mellitus].

In the last three years, new diagnostic criteria for diabetes mellitus have been proposed by the American Diabetes Association (ADA, 1997), the World Health Organization (WHO) consultation (1998), and the Japan Diabetes Society (JDS, 1999). The most important change from the previous WHO criteria (1985) to these criteria is a decrease in fasting plasma glucose level (FPG) from 140 mg/dl to 126 mg/dl, which defines diabetes mellitus. These criteria attach more importance to FPG than to plasma glucose levels 2 hours after 75 g glucose load (2 hPG). According to these criteria, for example, in one instance with FPG > or = 126 mg/dl, the diagnosis of diabetes mellitus is warranted, if the postprandial plasma glucose > or = 200 mg/dl or another FPG > or = 126 mg/dl were reconfirmed on a subsequent day. The ADA criteria did not recommend an oral glucose tolerance test (OGTT) for routine clinical use. These criteria has established a new category of impaired fasting glucose (IFG) (> or = 110 mg/dl and 126 < mg/dl), similar to impaired glucose tolerance (IGT) which is recognized by performing OGTT. We have reported from a cohort study that there was only one risk factor for IGF: worsening of metabolic derangement progressing to overt diabetes. With IGT, however, there are two risks: a risk for progression to diabetes, and a risk for development of cardiovascular disease. Therefore it seems that whether or not OGTT should be performed depends on the purpose: simply diagnosing for overt diabetes, or detecting risk factors for cardiovascular disease. The JDS criteria proposed the use of HbA1C as a supporting diagnostic tool, because JDS has achieved a fruitful standardization in Japan to a considerable extent. According to the JDS criteria, a diagnosis of diabetes mellitus can be made by an FPG > or = 126 mg/dl when HbA1C > or = 6.5% is confirmed. It is expected that these new criteria will promote further efforts against the increasing number of patients with diabetes mellitus.

Blood Glucose↗
PubMed1999

[Approach to examining hypercalcemia in the clinical laboratory].

The investigation of hypercalcemia is carried out routinely in our laboratory to detect primary hyperparathyroidism (PHPT). In a retrospective study, seven patients with PHPT and fifty-one patients with non-parathyroid hypercalcemia (NPHC) were chosen in a particular year. To obtain a screening index for PHPT, discriminant analysis, using a stepwise variable select method, was applied to eight biochemical parameters in these patients. A discriminant function (F1) was derived from three biochemical parameters and then another discriminant function (F2) was also derived from three biochemical parameters in the F1-positive patients. In combination of these two functions (F1 and F2), the final sensitivity was 100% and specificity was 98% in diagnosing PHPT. This screening method was tested prospectively in fifty-six consecutive specimens of hypercalcemia (PHPT 4, NPHC 52) over the following six months. The result was also satisfactory with a sensitivity of 100% and specificity of 98%. It was proven that our screening method using discriminant functions (F1 and F2) was very useful for diagnosing patients with PHPT from the survey of hypercalcemia. Among these patients with hypercalcemia, the high ratio (54%) of those with malignancy was remarkable. This interesting result required us to investigate potential hypercalcemia, since the serum calcium concentration was masked by a lower level of serum albumin, which was frequently seen in these malignant patients. As the next step, we tried to adjust the serum calcium concentration based on the serum albumin concentration. A formula for adjusting the calcium concentration was derived from a linear structural relationship between calcium and albumin in 6,821 specimens within a +/- 2.5 second principal component score in 7,021 consecutive specimens in whom both calcium and albumin were measured in a particular year; Adjusted Calcium = Calcium - Albumin + 4. After adjustment using this formula, the calcium concentrations were elevated above the upper limit of the reference interval in 320 of 5,203 specimens (6%) within the reference interval and elevated to the reference interval in 1,390 of 1,579 specimens (88%) below a lower limit of reference interval. A prospective study was performed over the following three months. Fifty patients with hypercalcemia were screened using this formula. It was a surprise that thirty-one patients (62%) showed abnormal values after adjustment. These results suggest that calcium adjustment is necessary for interpreting the calcium concentration of patients with a reduced albumin concentration such as patients with malignancy.

Adult↗
PubMed1998

Regional pharmacokinetics of doxorubicin following hepatic arterial and portal venous administration: evaluation with hepatic venous isolation and charcoal hemoperfusion.

We evaluated the regional pharmacokinetics of doxorubicin after hepatic arterial infusion (HAI) and portal venous infusion (PVI) using a novel system for hepatic venous isolation and charcoal hemoperfusion (HVI-CHP). The HVI-CHP system was used to determine directly the doxorubicin plasma concentration in the hepatic vein and the hepatic venous flow rate, and simultaneously, to eliminate hepatic re-entry of the drug. Beagles received doxorubicin (1 mg/kg) through either the hepatic artery (HAI group, n = 6) or the portal vein (PVI group, n = 6). In both groups, hepatic venous blood was completely isolated and directed to the CHP filter. The filtered blood was returned through the left jugular vein. During HVI-CHP, the hepatic venous flow rate was monitored and plasma doxorubicin concentrations were serially measured in prefilter (= hepatic venous), postfilter, and systemic blood. The hepatic tissue uptake of doxorubicin was determined based on the blood flow rate and doxorubicin level in the hepatic vein. The hepatic extraction ratio of doxorubicin was defined as the percentage hepatic tissue uptake to the amount of drug administered. During drug infusion, similarly in either group, HVI-CHP produced a 66-87% reduction of the postfilter doxorubicin level as compared with the prefilter level. The prefilter drug level was significantly lower in HAI group than in PVI group (P < 0.01). Thus, the area under the time concentration curve for the prefilter drug level in the HAI group (6.90+/-0.96 microg min/ml) was significantly lower than that in the PVI group (18.10+/-2.90 microg min/ml, P < 0.01). Conversely, the hepatic extraction ratio in the HAI group (84.6+/-2.9%) was significantly higher than that in the PVI group (58.1+/-3.4%, P < 0.01). We conclude that in the beagle, doxorubicin is more effectively extracted by the liver when administered via the hepatic artery than when administered via the portal vein. These results indicate that HAI of doxorubicin is superior to PVI in terms of reduction of systemic drug exposure and systemic toxicity.

Animals↗
PubMed1998

Expression of the Na+/Ca2+ exchanger emerges in hepatic stellate cells after activation in association with liver fibrosis.

Activation of hepatic stellate (Ito) cells is a final common pathway of liver fibrosis. The findings presented in this paper indicate that expression of Na+/Ca2+ exchanger (NCX) emerges in rat hepatic stellate cells after activation in vitro during primary culture or in vivo in response to intoxication with CCl4. NCX mRNA became detectable by Northern blot analysis in cultured stellate cells on day 3, as was alpha-smooth muscle actin, an indicator not only of smooth muscle differentiation but also of stellate cell activation. Western blot analysis showed expression of the exchanger protein in the activated stellate cells. Functional expression of the exchanger, monitored by Ni2+-sensitive, verapamil-insensitive intracellular free Ca2+ increases in response to reduction of extracellular Na+ concentration, became sizable by using Fura-2 in stellate cells by 7 days in culture. Furthermore, increased expression of the exchanger mRNA was found predominantly in stellate cells freshly isolated from the CCl4 model rat of hepatic fibrosis. Thus, it is concluded that NCX expression is closely associated with activation of hepatic stellate cells in vitro and in vivo. Because, even at the whole liver level, increased expression of NCX mRNA became observable after induction of liver fibrosis, it is suggested that NCX expression serves a useful diagnostic marker of liver fibrosis or cirrhosis.

Actins↗
PubMed1998

Resection of pheochromocytoma under inferior vena caval isolation and extracorporeal charcoal hemoperfusion.

Resection of pheochromocytoma is associated with potential risks of hypertensive crises and serious arrhythmias due to massive release of catecholamines from the tumor. We report our surgical experience with complete inferior vena caval isolation and extracorporeal charcoal hemoperfusion (IVCI-CHP), which were performed to prevent systemic exposure to catecholamines during surgical manipulation. The IVCI-CHP significantly reduced the postfilter and systemic catecholamine levels compared with the prefilter levels (P<.01), indicating substantial catecholamine extraction (>90%) by the CHP filter. Reflecting the reduction of systemic exposure to catecholamines during IVCI-CHP, the patient's blood pressures were markedly stable. Our findings suggest that IVCI-CHP may be useful to minimize the risk of hypertensive crises during surgical manipulation of pheochromocytoma, by preventing systemic exposure to high levels of circulatory catecholamines.

Adrenal Gland Neoplasms↗
PubMed1998

Percutaneous isolated liver chemoperfusion for treatment of unresectable malignant liver tumors: technique, pharmacokinetics, clinical results.

We have developed a single-catheter technique for percutaneous isolated liver chemoperfusion (PILP) with hepatic venous isolation and charcoal hemoperfusion (HVI-CHP) for the treatment of malignant liver tumors. We report here the surgical technique, pharmacokinetics, and effectiveness of PILP in multiple advanced liver tumors. Twenty-eight patients with hepatocellular carcinoma (HCC) and 18 with metastatic liver tumors underwent a total of 61 PILPs with HVI-CHP. HVI-CHP was accomplished mainly by the single-catheter technique using a novel four-lumen, two-balloon catheter; it was used to isolate and capture total hepatic venous outflow and, at the same time, to direct the filtered blood to the right atrium. Under HVI-CHP, either doxorubicin 960-150 mg/m2) or cisplatin (150-200 mg/m2) was infused via the hepatic artery. The PILP was completed successfully in all 61 trials. Two of forty-six patients died early; one of necrotizing pancreatitis and the other of hepatic arterial thrombosis. Both deaths were related directly to the hepatic arterial catheter. Excluding these two deaths, the treatments were well tolerated. The major side effects were mild to moderate chemical hepatitis and reversible myelosuppression. Of the 27 evaluable HCC patients, 17 (63%) had an objective tumor response (5 complete and 12 partial responses). In 15 patients with colorectal hepatic metastases (CHM), 7 had a sharp decrease in serum carcinoembryonic antigen (CEA) levels (to < 50% of their pretreatment levels) after treatment. However, a single PILP had limited efficacy in terms of the durability of remission (< or = 6 months in most CHM patients, as assessed by CEA levels). These results indicate that PILP with HVI-CHP has high efficacy in most patients with multiple advanced liver tumors. In addition, the results suggest a role of multiple treatment courses of PILP in the induction of long-term remission, especially for patients responsive to the first treatment.

Antineoplastic Agents↗
PubMed1998

Ineffective use of a detachable snare for colonoscopic polypectomy of large polyps.

BACKGROUND: Colonoscopic polypectomy of large polyps may be associated with complications such as bleeding. Use of a detachable snare may reduce the risk of bleeding. We describe several instances in which the use of such a device proved to be ineffective. METHODS: A detachable snare was used for colonoscopic polypectomy of large polyps in 18 patients (20 polyps), also applied at the residual stalk after conventional polypectomy in 5 patients (5 polyps), and evaluated retrospectively. RESULTS: Sixteen of the 20 polyps were pedunculated, and 4 were semi-pedunculated. In 3 of the 4 semi-pedunculated lesions, the loop slipped off after polypectomy because the lesions were cut close to the site of encirclement. Bleeding occurred in 4 cases because of transection by the loop of a thin stalk (4 mm) before polypectomy (1), slipping of the loop in a semi-pedunculated lesion (1), or insufficient tightening of the loop (2). After conventional polypectomy, we could not effectively snare the residual stalk because of flattening in 3 of the 5 lesions. CONCLUSIONS: Use of the detachable snare for polypectomy of thin stalked or semi-pedunculated lesions may result in technical failure of this technique. The stalk should be fully encircled with the snare before polypectomy. The detachable snare is difficult to apply at the residual stalk after conventional polypectomy.

Aged↗
PubMed1998

Impaired vagus nerve-mediated control of insulin secretion in Wistar fatty rats.

It has been reported that hyperglycemia in the portal venous blood suppresses afferent activity of the hepatic branch of the vagus nerve, which in turn accelerates efferent activity of the pancreatic branch of the vagus nerve to stimulate insulin secretion. The present study examined this neural control mechanism in genetically obese diabetic male Wistar fatty (fa/fa) rats. Adult (aged 12 to 14 weeks) Wistar fatty rats were obese, hyperinsulinemic, and hyperglycemic. Young (aged 5 to 6 weeks) Wistar fatty rats were slightly obese and hyperinsulinemic, but were euglycemic compared with the lean littermates. In both adult and young lean littermates, the plasma insulin response after an intragastric glucose load (1 g/kg) was diminished by intracerebroventricular (i.c.v.) atropine methylbromide (methylatropine 10 nmol) pretreatment, and a transient increase in plasma insulin was observed after selective hepatic vagotomy, as reported in normal rats. In contrast, in both adult and young Wistar fatty rats, the plasma insulin response after an intragastric glucose load was not diminished by i.c.v. methylatropine pretreatment, and plasma insulin decreased slightly after selective hepatic vagotomy. Further, afferent discharges of the hepatic vagal branch decreased and efferent discharges of the celiac/pancreatic vagal branch increased when 10 mg glucose was infused into the portal vein in the 9-week-old lean littermates, as reported in normal rats. In 7-week-old Wistar fatty rats, afferent discharges of the hepatic vagal branch decreased but efferent discharges of the celiac/pancreatic vagal branch did not increase after intraportal glucose infusion. It is concluded that the vagus nerve-mediated regulation of insulin secretion is impaired from an early stage of life in Wistar fatty rats. Efferent discharges of the vagus nerve to the pancreas seem not to be suppressed by afferent discharges from the hepatic vagus branch, which may lead to insufficient insulin secretion in response to nutrient ingestion followed by a delayed peak. These abnormalities may thus lead to the insulin resistance and fasting hyperinsulinemia that characterize the Wistar fatty rat model.

Animals↗
PubMed1998

Effect of adrenomedullin on ion transport and muscle contraction in rat distal colon.

We have investigated the effects of adrenomedullin (AM) on mucosal ion transport using the Ussing method and smooth muscle contraction using the Magnus method in rat. Our results indicate that AM increases Isc (short-circuit current) for Cl- secretion (100 nM:170.0 +/- 41.2%, 1 microM:193.8 +/- 45.5%, 100% Isc:28.2 +/- 3.1 microA/cm2) with an initial small decrease of Isc, inhibiting Na+ absorption. Tetrodotoxin (TTX) inhibits the Isc response elicited by AM (86%). In addition, AM relaxes potassium-induced contraction (10 nM:11.1 +/- 8.51%, 100 nM:33.4 +/- 12.7%, 100% contraction: 1.8 +/- 0.22 g), and TTX inhibits the response elicited by AM (90%). We conclude that AM modulates water and ion transport as well as bowel movement, mainly through the colonic nervous system.

Adrenomedullin↗
PubMed1998

The cloned capsaicin receptor integrates multiple pain-producing stimuli.

Capsaicin, the main pungent ingredient in "hot" chili peppers, elicits buming pain by activating specific (vanilloid) receptors on sensory nerve endings. The cloned vanilloid receptor (VR1) is a cation channel that is also activated by noxious heat. Here, analysis of heat-evoked single channel currents in excised membrane patches suggests that heat gates VR1 directly. We also show that protons decrease the temperature threshold for VR1 activation such that even moderately acidic conditions (pH < or = 5.9) activate VR1 at room temperature. VR1 can therefore be viewed as a molecular integrator of chemical and physical stimuli that elicit pain. Immunocytochemical analysis indicates that the receptor is located in a neurochemically heterogeneous population of small diameter primary afferent fibers. A role for VR1 in injury-induced hypersensitivity at the level of the sensory neuron is presented.

Afferent Pathways↗
PubMed1998

Apoptosis in labial salivary glands from Sjögren's syndrome (SS) patients: comparison with human T lymphotropic virus-I (HTLV-I)-seronegative and -seropositive SS patients.

Apoptosis is a type of cell death that occurs during morphogenesis and development of the immune system. One of the mechanisms is mediated through the Fas and Fas ligand (FasL) pathway. To determine the possible involvement of Fas and its ligand in salivary gland destruction, we analysed the appearance of nuclei with DNA fragmentation by using nick end labelling (TUNEL) and the expression of Fas and FasL by immunohistochemistry in labial salivary glands. Furthermore, we compared the features of apoptosis in labial salivary glands between HTLV-I- and HTLV-I+ SS. When the frozen sections of 10 primary SS patients in the absence of anti-HTLV-I antibody were examined, several apoptotic cells were found in the acinar and ductal epithelial cells as well as infiltrated mononuclear cells. Both Fas and FasL were detected in the infiltrated mononuclear cells. Acinar epithelial cells, which are surrounded by FasL+ mononuclear cells, were also double-positive with Fas and FasL, although the expression of FasL was localized at their apical border, suggesting that apoptosis of mononuclear cells was achieved by activation-induced mechanisms through Fas/FasL pathways, and that of acinar epithelial cells was mediated by FasL derived from either acinar epithelial cells themselves or infiltrated mononuclear cells. Interestingly, Fas expression in ductal epithelial cells was localized around the lumen side of the ducts, indicating that FasL secreted from acinar epithelial cells may induce Fas-mediated apoptosis of ductal epithelial cells. We also studied the labial salivary glands from nine SS patients with anti-HTLV-I antibodies. There was no significant difference in the occurrence of apoptotic cells or in the expression of Fas and FasL between HTLV-I+ and HTLV-I- SS patients. It was of note that neither the expression of Fas and FasL nor the presence of apoptotic cells were determined in labial salivary glands from subjects without SS. These findings indicate that Fas-mediated apoptosis in salivary glands could be involved in the pathological manifestations of SS, irrespective of HTLV-I seropositivity.

Adult↗
PubMed1998

Efficacy of total colonoscopy with a transparent cap in comparison with colonoscopy without the cap.

BACKGROUND AND STUDY AIMS: In spite of scrupulous inspection during routine colonoscopy, small lesions behind the semilunar folds can be situated in blind spots, where they are easily overlooked. The aim of this study was to evaluate the efficacy of total colonoscopy with a transparent cap in identifying such lesions, in comparison with colonoscopy without the cap. PATIENTS AND METHODS: In 24 patients with colorectal polyps, tandem colonoscopic procedures were carried out on the same day in random order, first without a transparent cap and then with the cap (without-to-with), or first with the cap and then without the cap (with-to-without). The time required for intubation as far as the cecum, the number of polyps detected, and procedure-related complications were recorded. The frequencies of terminal ileal intubation and retroflexion within the rectum were also recorded. RESULTS: Total colonoscopy was carried out in all of the patients without any complications. Colonoscopy with a transparent cap ensured good visual fields during insertion and withdrawal of the colonoscope. There were no significant differences in the intubation time to the cecum or in the frequency of terminal ileal intubation between the two procedures. The miss rate for polyps was 15% in without-to-with tandem colonoscopies, and zero in with-to-without procedures (P = 0.0125). The diameter of all the missed polyps except for one lesion (8 mm) was less than 5 mm. Retroflexion within the rectum was more difficult using the colonoscope with the cap (P < 0.0001), and was successful in only one case using the cap. CONCLUSIONS: Total colonoscopy with a transparent cap allows inspection of the blind area of the colonic mucosa behind the semilunar folds, with good visual fields. This method is potentially useful for both screening and diagnostic purposes.

Adult↗