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Biomedical subjects

Y Shoji

Publications and source records attributed to Y Shoji.

At least 91 records · Page 5Linked to original sources
PubMed1996

Use of transrectal ultrasonography to select type of surgery for villous tumors in the lower two thirds of the rectum.

OBJECTIVE: To determine the accuracy of transrectal ultrasonographic (TRUS) staging of rectal villous tumors when used to select a surgical procedure. DESIGN: Case series. SETTING: College hospital, Hyogo, Japan. PATIENTS: From 1988 to 1995, 24 patients were treated for villous tumors after diagnosis by TRUS, and were followed up for 0.5 to 7.5 years. MAIN OUTCOME MEASURES: Ultrasonographic tumor stage (u-T), pathologic tumor stage (p-T), biopsy findings, and surgical procedures were studied. RESULTS: Overall, 71% of the tumors were accurately staged by TRUS. However, 4 u-T1 and 3 u-T2 tumors were overstaged, with pathological examination showing 2 adenomas and 5 p-Tis tumors. Three of these 7 patients were overtreated surgically. The results of a biopsy predicted adenoma in 2 of the u-T1 tumors and 2 of the u-T2 tumors that were overstaged by TRUS. Pathological examination revealed that an enlarged lymphoid follicle in the mucosa had deformed the thin muscle layer of the rectal wall and abolished its continuity on TRUS imaging. The weakness of TRUS would seem to be in the accuracy of p-Tis staging. CONCLUSIONS: Transrectal ultrasonography had the advantage of predicting malignant infiltration in rectal villous tumors. The surgeon should know the limitations of TRUS diagnosis to select the most appropriate operation for each patient.

Adenocarcinoma↗
PubMed1996

Role of reactive oxygen intermediates in lipopolysaccharide-mediated hepatic injury in the rat.

Because reactive oxygen intermediates derived from xanthine oxidase may have an important role in the pathophysiology of lipopolysaccharide-mediated tissue injury, we studied hydrogen peroxide generation using 3-amino-1,2,4-triazole inactivation of hepatic catalase and the ratio of xanthine oxidase to xanthine dehydrogenase activity in rat livers after in vivo lipopolysaccharide administration. We also studied the effect of tungsten, a potent inhibitor of xanthine oxidase, on the toxicity of lipopolysaccharide. There was increased hydrogen peroxide production and enhanced proteolytic conversion from xanthine dehydrogenase to xanthine oxidase in rat livers after lipopolysaccharide administration. Feeding rats a tungsten-rich diet for 4 weeks greatly diminished hepatic xanthine oxidase activity and lessened the rise in intracellular hydrogen peroxide production after lipopolysaccharide treatment. Liver damage, as assessed by the serum transaminase levels and mortality, was also ameliorated by the tungsten-rich diet. These findings suggest that hydrogen peroxide derived from xanthine oxidase contributes to the development of systemic toxicity and liver damage after lipopolysaccharide administration.

Adenosine↗
PubMed1996

Implantation of human colorectal carcinoma cells in the liver studied by in vivo fluorescence videomicroscopy.

In vivo fluorescence videomicroscopy (IVFM) was used to analyse the behavior of weakly and highly metastatic human colorectal carcinoma (CRC) cells during implantation in the liver. A highly metastatic human CRC cell line, CX-1, and a weakly metastatic line, Clone A, were double-labeled with rhodamine B isothiocyanate-dextran (Rd-Dx) to locate cells and with calcein AM to assess cell metabolic activity in an experimental metastasis model. Double-labeled CRC cells (2.0 x 10(6)) were injected into the spleens of groups of nude mice and the livers observed by IVFM over the next 72 h. CRC cells were implanted within 30 s after injection into either portal venules or the proximal third of hepatic sinusoids. Approximately 0.5% of CRC cells traversed the liver through portal-central venous shunts and implanted in the lung. The number of CX-1 cells in the liver was similar to that of Clone A cells during the first 12 h. However, more CX-1 cells than Clone A cells remained in the liver at 4 h and were in groups of 8-12 cells whereas only a few, single Clone A cells were detected in the liver at 72 h. Not all Clone A cells are committed to die within 4 h of implantation because cells harvested 4 h after hepatic implantation proliferated normally in vitro when removed from the hepatic microenvironment. Since the stress of mechanical deformation during implantation may cause differences in cell survival, CX-1 and Clone A cells were passed through filters with 8 microM pores in vitro at 10-15 cm of water pressure to recreate the trauma of hepatic implantation. Approximately 50% of both CX-1 and Clone A cells were lysed. Furthermore, both CRC lines remained metabolically active when co-cultivated with liver cells for at least 24 h in vitro. Thus, the difference in metastatic potential between the two CRC lines may reside in their response to the combination of mechanical implantation and subsequent growth in the liver parenchyma.

Animals↗
PubMed1996

Defecographic assessment after colonic J pouch-anal anastomosis.

Colonic J pouch anal anastomosis is widely employed after rectal resection. In the 36 patients who participated in our retrospective study, although postoperative continence was retained/maintained in each individual, a survey questionnaire indicated some difficulties in neoanorectal function. Therefore, defecography was performed in 20 of these patients. Patients experiencing soiling were found to have an increased ano-pouch angle and pelvic floor descent. Loss of sensation and incomplete evacuation were also associated with an abnormally large pelvic floor descent. However, stool frequency, urgency, and the need for medication showed no correlation with any of the defecography parameters. These findings thus suggested that the puborectal muscle and the levator ani muscle played an important role in postoperative function. Defecography was also found to provide a dynamic assessment of the postoperative state of colonanal reconstruction.

Aged↗
PubMed1996

Modification of the stapled functional end-to-end anastomosis for ileostomy closure.

The use of stapling devices simplifies ileostomy closure; however, the original functional end-to-end anastomotic technique creates intersecting staple lines, generally causing disruption of the anastomosis at the intersections. Therefore, we modified the stapling technique to prevent the two staple lines from crossing. After the everted ileostomy spout is turned back, a stapled side-to-side anastomosis is made. Everting traction sutures are then placed around the ileostomy orifice prior to closure with a linear stapler, thus ensuring that this staple line does not cross the V-shaped staple line of the intestinal anastomosis. This modified technique was employed in the treatment of 20 patients, none of whom developed any signs of anastomotic leakage or intestinal obstruction.

Anastomosis, Surgical↗
PubMed1996

Preoperative detection of distal intramural spread of lower rectal carcinoma using transrectal ultrasonography.

PURPOSE: Usefulness of transrectal ultrasonography (TRUS) for detecting distal intramural spread of rectal carcinoma was investigated. METHODS: Thirty-seven patients with advanced rectal carcinoma, who had not received preoperative adjuvant therapy, underwent TRUS before surgery. Distal intramural spread was evaluated by TRUS and by pathologic examination of resected specimens. RESULTS: Distal intramural spread was found in 7 of 37 patients (19 percent) by pathologic examination. Presence or absence of distal intramural spread was correctly diagnosed by TRUS in 86 percent of the 37 patients. Misdiagnosis by TRUS mainly occurred when distal intramural spread was 5 mm. Tumor penetration of muscularis propria, lymph node involvement, and a higher histologic grade of malignancy showed a significant relationship with the presence of distal intramural spread. CONCLUSION: TRUS was useful for detecting distal intramural spread > 5 mm in patients with lower rectal carcinoma and may be helpful for selecting appropriate surgery.

Adenocarcinoma↗
PubMed1996

Clinico-physiological results after sphincter-saving resection for rectal carcinoma.

In this study, we evaluated the postoperative functional results after resection of rectal carcinoma. A questionnaire and anal manometry were used to evaluate the severity of the symptoms. The patients were divided into the three groups of anterior resection (AR, 38 patients), low anterior resection (LAR, 34 patients) and stapled colo-anal anastomosis (SCA, 20 patients). Manometric examination and questionnaire evaluation were performed 1, 3, 6, and 12 months after the operation. The SCA group showed by far the poorest outcome in terms of soiling and urgency at 12 months. Anal sensation was recovered by 12 months in each group. Incomplete evacuation was frequently observed in the SCA and LAR groups. Each anal manometric parameter recovered in the AR group, but the maximum tolerable volume of the neorectum did not recover in either the SCA or LAR group. The threshold volume of the SCA group was lower than those in the other two groups. The reservoir function of the neorectum, which is composed of the colorectal muscle layer and nervous components, plays a role in maintenance of bowel function.

Adult↗
PubMed1996

Extracardiac conduit composed of gutter-shaped prosthesis and pedicled pericardial valved patch for pulmonary trunk reconstruction.

A conduit for reconstruction of the pulmonary trunk is presented. A Gelseal vascular prosthesis (Vascutek Ltd, Inchinnan, Scotland) was split longitudinally in two halves, and one half was used as a posterior wall of the conduit like a gutter. The anterior wall was constructed by a pedicled pericardial valved patch. Finally, the proximal anastomosis of the conduit was completed with a gusset cut from the Gelseal prosthesis. This conduit can be applied to patients who require the Rastelli procedure, and growth potential of the pedicled pericardial patch may be expected.

Blood Vessel Prosthesis↗
PubMed1996

5'-linked lipid-oligodeoxyridonucleotide derivatives as inhibitors of human immunodeficiency virus replication.

The covalent attachment of a phospholipid moiety, bound to the 5'-ends of phosphodiester and phosphorothioate oligonucleotides (L-ODNs and LS-ODNs), was achieved using H-phosphonate chemistry, and the lipid-oligonucleotides were assayed for the inhibition of virus replication in HIV-1 infected MT-4 cells. In the anti-HIV activity test, lipid-phosphorothioate oligonucleotides showed higher anti-HIV activities than non-lipid-phosphorothioate oligonucleotides, at the low concentration of 0.04 microM. LS-ODNs can inhibit HIV-1 reverse transcriptase activity through interactions with the enzyme. We found that the covalent attachment of a phospholipid group to the 5'-end of the phosphorothioate oligonucleotide enhances its nonsequence specific anti-HIV activity.

Base Sequence↗
PubMed1996

Changes of intraaortic balloon volume during pumping in a mock circulation system.

The effects of hemodynamic changes on intraaortic balloon (IAB) volumes were studied experimentally using a helium tachometer in a mock circulatory system. The IAB volume decreased with increases in the heart rate and mean aortic pressure, but the degree of reduction in the IAB volume was different among 4 commercially available IAB drivers. Improvements in IAB consoles are needed to compliment the progress made in percutaneous techniques for IAB insertion resulting in smaller balloons.

Arrhythmias, Cardiac↗
PubMed1996

Cellular uptake and biological effects of antisense oligodeoxynucleotide analogs targeted to herpes simplex virus.

In this study, we synthesized antisense oligodeoxynucleotides (ODNs) with phosphodiester, phosphorothioate (S-ODNs), or methylphosphonate linkages complementary to the splicing acceptor site of immediate-early pre-mRNA 5 of herpes simplex virus type 1 (HSV-1). The antiviral activity of each analog on cytopathic effect in cells infected with HSV-1 or HSV-2 was assessed and compared with the cellular uptake of the analog. We found that antisense S-ODNs showed the most potent antiherpetic activity, with 50% inhibitory concentrations of 5 microM for HSV-1 and 0.25 microM for HSV-2. The antiviral effect of antisense S-ODNs was stronger and longer acting than that of acyclovir. Cell association of S-ODNs was the highest and paralleled antiviral activity. Furthermore, some fluorescein isothiocyanate (FITC)-labeled S-ODNs were recognized in the nuclei in HSV-1 infected cells by confocal laser scanning microscopy. S-ODNs located in the nucleus could access the targeted mRNA, which might be responsible for the antiviral activities. Although our study also showed non-sequence-specific activity, which implies that multiple mechanisms are involved, S-ODNs are a promising novel anti-herpetic agent.

Animals↗
PubMed1996

Correlation of apoptosis with tumour cell differentiation, progression, and HPV infection in cervical carcinoma.

AIMS: To clarify the significance of apoptosis in the progression of uterine cervical neoplasias, including cervical intraepithelial neoplasia (CIN), microinvasive carcinoma (MIC), and invasive squamous cell carcinoma (ISCC) categories, in relation to cell proliferation and human papilloma virus (HPV) infection. METHODS: Forty six cases of CIN I/II, 75 of CIN III, 16 of MIC, and 44 of ISCC were examined using formalin fixed and paraffin wax embedded samples. The TdT mediated dUTP-biotin nick end labelling (TUNEL) method for detection of apoptotic cells was performed along with Ki-67 immunohistochemistry. Presence of HPV-DNA was confirmed by PCR-RFLP assay. RESULTS: Apoptotic labelling indices, calculated after counting positive nuclei among at least 2000 nuclei, showed significant positive correlation with histological malignant grading in CIN and tumour cell invasion into stroma. In contrast, similar Ki-67 labelling index values were found in CIN, MIC, and ISCC. Although HPV-DNA was detected in 35/46 CIN I/II (76.1%), 53/74CIN III (71.6%), 9/16 MIC (56.3%), and 36/44 ISCC (81.8%), there was no apparent relation with the apoptotic labelling indices. CONCLUSIONS: Apoptosis in cervical neoplasias may be closely related to tumour cell differentiation and progression. It also seems unlikely that HPV itself is directly related to pathways regulating apoptosis.

Apoptosis↗
PubMed1996

Effect of a nonpeptide vasopressin V1 antagonist (OPC-21268) on experimental accelerated focal glomerulosclerosis.

The effects of the nonpeptide orally effective vasopressin V1 receptor antagonist OPC-21268 were studied in progressive focal glomerulosclerosis (FGS) which developed in spontaneously hypercholesterolemic (SHC) rats with manifestations of hypercholesterolemia and proteinuria. Unilateral nephrectomy was performed at 7 weeks of age to accelerate spontaneous FGS. After nephrectomy, OPC-administered rats were fed chow containing 1% OPC-21268 for 9 weeks. Treatment with vasopressin V1 antagonist significantly reduced the rate of increase in the levels of triglyceride, systolic blood pressure, serum creatinine and BUN, and prevented a significant deterioration in creatinine clearance. Rats were sacrificed at 16 weeks of age. Histologically, the index of glomerular sclerosis in the OPC group showed a significant decrease compared to that in the control group (2.2 +/- 0.1 vs. 2.6 +/- 0.1, p < 0.01). Relative interstitial volume and glomerular volume in the OPC group showed a tendency to decrease compared to those in the control group. These results indicate that vasopressin plays an important role through V1 receptors in the development of glomerulosclerosis, and vasopressin V1 antagonist may prevent the progression of renal injury in glomerulosclerosis.

Animals↗
PubMed1996

[Acute aortic dissection with leg ischemia].

From January of 1987 to July of 1994, 83 patients with acute aortic dissection were treated at our institution. Of these, 7 patients (8%) sustained acute leg ischemia. Angiography showed that one patient had arterial occlusion at the abdominal aorta, three had occlusion at the right common iliac artery, and one had severe right common iliac artery stenosis. Four patients with acute type A dissection underwent emergency replacement of the aortic arch and/or ascending aorta. Three of them were discharged, but one patient died due to renal failure and multiple organ failure. In three patients with acute type B dissection, one with aortic rupture was successfully treated by replacement of the descending thoracic aorta; of the other two who received bypass operations for leg ischemia, one died due to myonephropathic metabolic syndrome and sepsis which were caused by a delay in surgery. In conclusion, emergency thoracic aortic repair should be performed in acute type A dissection with leg ischemia, whereas bypass operation for ischemic leg should be considered in patients of acute type B dissection with leg ischemia when they are not complicated with rupture or visceral ischemia.

Acute Disease↗
PubMed1996

Cellular uptake mechanism for oligonucleotides: involvement of endocytosis in the uptake of phosphodiester oligonucleotides by a human colorectal adenocarcinoma cell line, HCT-15.

We used a 20-mer antisense oligonucleotide against human MDR1 mRNA to study the mechanism of uptake of oligonucleotides by a human colorectal adenocarcinoma cell line, HCT-15.5'-end-32P-labeled oligonucleotides were mainly used. The uptake of phosphodiester oligonucleotides (D-oligo) by HCT-15 cells increased with time, but the uptake of phosphorothioate oligonucleotides (S-oligo) showed minimal increases with time. HeLa cells showed a 4-fold greater D-oligo uptake than did HCT-15 cells, and other cell lines exhibited a 25-fold lower uptake than did HCT-15 cells. On the other hand, S-oligo uptake varied only severalfold among the cell lines used. Doligo up-take consisted of a saturable component (Michaelis constant K(m) = 0.16 microM and maximal uptake rate Vmax = 4.8 pmol/min/mg for HCT-15 cells and K(m) = 0.21 microM and Vmax = 35.6 pmol/min/mg for HeLa cells), i.e., the difference between the cell types was mainly in Vmax. The uptake of labeled D-oligo was inhibited by unlabeled S-oligo at a much lower concentration (Ki = 0.01 microM) than by unlabeled D-oligo (K(m) = 0.16 microM), although the uptake rate of D-oligo was greater than that of S-oligo. The D-oligo uptake was highly temperature dependent. Of the sulfhydryl-modifying reagents (p-chloromercuriphenyl-sulfonic acid and p-chloromercuribenzoic acid), only p-chloromercuribenzoic acid inhibited D-oligo uptake, suggesting the involvement of a protein whose sulfhydryl residues inside the cell are critical for D-oligo uptake. Chloroquine and monensin, which are known to alter the intracellular fate of ligands and receptors, did not affect D-oligo uptake, but phenylarsine oxide, an inhibitor of internalization processes, inhibited uptake significantly. Down-regulation and recovery of D-oligo uptake induced by excess unlabeled D-oligo pretreatment occurred, but this was only partial. Studies with a digitonin equilibrium method and confocal microscopy indicated that intracellular localization of D-oligo was mainly in a vesicular compartment. More stable 3'-end-32P-labeled oligonucleotides were also used, to compare their uptake characteristics with those of the 5'-end-labeled oligonucleotides. The uptake characteristics for the two labels were similar in terms of saturability, greater D-oligo uptake, compared with S-oligo, and the inhibitory effect of p-chloromercuribenzoic acid; however, the stable 3'-end label showed greater uptake than the 5'-end label. Our findings suggest that D-oligo uptake by HCT-15 cells is mediated by endocytosis involving binding sites on the plasma membrane.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1995

The possible role of bcl-2 expression in the progression of tumors of the uterine cervix.

BACKGROUND: A close link between human papillomavirus (HPV) and the development of uterine cervical neoplasias has been proposed. However, other cofactors also are required for malignant transformation. METHODS: Forty-six cervical intraepithelial neoplasias (CIN) I/II, 75 CIN III, and 60 invasive squamous cell carcinomas (ISCC) were investigated by immunohistochemical staining for bcl-2 protein (bcl-2), bax protein (Bax), estrogen receptor (ER), and progesterone receptor (PR). The presence of HPV-DNA was examined using the polymerase chain reaction assay. RESULTS: bcl-2 immunoreactivity was found in 17 of 46 (37%) CIN I/II, 48 of 75 (64%) CIN III, and 12 of 60 (20%) ISCC, the positivity in CIN III being significantly higher than in CIN I/II or ISCC (P < 0.004, P = 0.0001). The bcl-2 immunostaining pattern could be subdivided into two groups, basal type and diffuse type, with the incidence of the latter being clearly increased, in line with tumor progression. In the Bax or HPV-DNA positive groups, bcl-2 positive cases in CIN I/II were in the minority, whereas in CIN III they constituted the majority. In ISCC, bcl-2 positive was significantly lower than negative cases, not being associated with Bax and HPV-DNA. Estrogen receptor and PR immunoreactivity were rare. CONCLUSIONS: These results indicate that bcl-2 may play an important role in a relatively early stage of cervical tumorigenesis, in association with Bax expression and HPV infection.

Carcinoma, Squamous Cell↗
PubMed1995

Experiences with the linear cutter technique for performing Roux-en-Y anastomosis following total gastrectomy.

The use of stapling devices for performing gastro-intestinal anastomosis has recently gained wide acceptance. In fact, since 1991, we have been using linear cutter devices for performing the Roux-en-Y anastomosis, transection of the duodenum, and closure of the jejunal stump (except following esophagojejunostomy), and are no longer employing hand-sewn procedures. In this report, the linear cutter technique used after total gastrectomy is described and the differences in anastomotic leakage, morbidity, operating time, and reconstruction time are evaluated in comparison with those following hand-sewn anastomoses. A total of 22 patients undergoing total gastrectomy within a 2-year period were randomized into two groups of 11, to have reconstruction performed by either a stapled or hand-sewn Roux-en-Y anastomosis. One patient from the stapled group died of acute myocardial infarction 6 days after the operation. Anastomotic leakages from the esophagojejunostomy region occurred in 18% of the patients in the stapled group, but fortunately no leakage was apparent from the Y-anastomosis when the linear cutter technique was used. The most obvious significance was the short mean reconstruction time in the stapled group of 19.1 +/- 3.56 min (P < 0.01) being 31 min shorter than that of the hand-sewn group (n = 11). Thus, we proposed that the linear cutter technique is a safe technique for performing anastomosis following total gastrectomy, which would significantly reduce the reconstruction time.

Adenocarcinoma↗