Peritoneal washing cytology combined with immunocytochemical staining and detecting mutant K-ras in pancreatic cancer: comparison of the sensitivity and availability of various methods

Peritoneal metastases are the second most common site of involvement, following the liver, in pancreatic cancer. Thus, we performed peritoneal washing cytology at laparotomy to diagnose accurately the intraperitoneal spread of carcinoma cells to determine the appropriate therapy. Peritoneal washings were collected at laparotomy from 20 Japanese pancreatic carcinoma patients at Nagoya University Hospital between April 1993 and December 1994. From centrifuged deposits, we examined the cytology by three methods as follows. The first method was conventional cytology, including May-Grünwald and Giemsa, Papanicolaou, periodic acid-Schiff, and Alcian blue. The second method was immunocytochemical staining, using antibodies to carbohydrate antigen (CA19-9) and carcinoembryonic antigen. After extracting DNA from the remaining pellet, we studied the last method, detecting K-ras point mutation, by two-step polymerase chain reaction and restriction fragment length polymorphism analysis. In two cases, peritoneal metastases were macroscopically recognized, and the results of all three methods were positive. In the two other cases, where peritoneal dissemination was not macroscopically recognized, the judgments of conventional cytological study and detecting K-ras point mutation were negative. However, a few malignant cells were found by the immunocytochemical staining method. Judging from their clinical course, the positively stained cells were suggestive of malignancy. At present, the immunocytochemical staining method is the most sensitive of these three methods in peritoneal washing cytology. However, preserving DNA is suitable for repeated examination, and a modified method can be applied. If the sensitivity increases, the method of detecting K-ras has the potential to become the standard for peritoneal washing cytology in pancreatic cancer.

[Diagnosis of local recurrence of colorectal cancer, using PET and immunoscintigraphy by means of 131I or 111In anti-CEA monoclonal antibody]

The accurate and early diagnosis of the tumor in the point of the size, the location, the depth of invasion of other organs or the stages of the recurrent cancer became much more important than before, not only for the selection of the treatment method but also for the decision of the quality of the operation for preserving the function as much as possible for the quality of the life of the patient. The usefulness of positron emission tomography (PET) and immunoscintigraphy by means of 131I or 111In anti-CEA onoclonal antibody for the diagnosis of the recurrent colorectal cancer had been confirmed in clinical use of colorectal cancers. No adverse effect of this monoclonal anti-body of the mouse was seen in this studies. The differential absorption ratio (DAR) was useful indicator in PET-imaging to differentiate the true tumor tissue from the scar tissue or granulation-tissue around the tumor. Even though the imaging, structure of PET is inferior to those of CT or MRI, the imaging of PET reflects the biological character of tumor, itself and makes the more accurate diagnosis possibly by combined use with regular CT and MRI.

Peritoneal dissemination is inhibited by treatment with antibodies against CD44H, beta(1) integrin, and carcinostatic agents in NUGC-4 human gastric cancer cells

Peritoneal dissemination frequently occurs after surgery in patients with gastric cancer. The presence of peritoneal metastasis after surgery affects the prognosis, therefore, a way must be found to effectively prevent the development of peritoneal dissemination. Very little is known about the biochemical processes involved in the initial attachment of gastric cancer cells to peritoneal mesothelial cells. We conducted in vitro and in vivo studies to assess the role of adhesion molecules and TGF-beta 1 in this process, using 4 gastric cancer cell lines. NUGC-4 cells, which disseminate early after inoculation into the abdominal cavity of nude mice, predominantly expressed CD44H and beta(1) integrin. We found that NUGC-4 cells adhered to monolayers of mesothelial cells more firmly than other cell lines. Adhesion of NUGC-4 cells to mesothelial cells was partially inhibited by antibodies against CD44H or the beta(1) subunit of integrin, and was completely blocked by a combination of these 2 antibodies. Treatment with ligands for CD44H and beta(1) integrin also inhibited this adhesion. In the NUGC-4 cell culture medium, larger amounts of transforming growth factor beta 1(TGF-beta 1) was detected in proportion to the increase in cancer cells than in the other cell lines. TGF-beta 1 increased the expression of CD44H in NUGC-4 cells and in mesothelial cells, and augmented the adhesion and implantation of NUGC-4 cells to mesothelial cells accompanied by accumulation of extracellular matrix (ECM) components. Carcinostatic agents decreased the expression of CD44H but increased the expression of E-cadherin in NUGC-4 cells. Treatment with carcinostatic agents and antibodies against CD44H and beta(1) integrin inhibited the dissemination of NUGC-4 cells in the peritoneal cavity of nude mice, and prolonged their survival time. These findings suggest that CD44H and integrins mediate in the initial attachment of gastric cancer cells to mesothelial cells, and TGF-beta 1 participates in the promotion of the disease. It is possible that a treatment strategy that interferes with CD44H or integrins function and increases the functions of E-cadherin immediately after surgery may result in the decreased intra-abdominal spread of gastric cancer.

Adhesion of human gastric and pancreatic cancer cells to peritoneal mesothelial cells is mediated by CD44 and beta(1) integrin

Peritoneal dissemination is a common cause of the recurrence of gastric or pancreatic cancer after patients have undergone surgery. The presence of peritoneal metastasis after surgery affects the prognosis of patients with gastric or pancreatic cancer. Very little is known about the biochemical processes involved in the initial attachment of cancer cells to peritoneal mesothelial cells. We conducted in vitro and in vivo studies to assess the role of adhesion molecules in this process, using 5 cell lines derived from human gastric and pancreatic cancers. NUGC-4 and SW1990 cells, which disseminate earlier than the other 3 types of cancer cells after inoculation into the abdominal cavity of nude mice, express large amounts of CD44H. We found that NUGC-4 and SW1990 cells adhere to monolayers of mesothelial cells more firmly than the other cell lines, as shown by adhesion assays performed at 4 degrees C. The adhesion of NUGC-4 and SW1990 cells to mesothelial cells was partially inhibited by antibodies against CD44H or the beta(1) subunit of integrin, and they almost completely blocked adhesion when these 2 antibodies were used in combination in vitro. These 2 antibodies also inhibited the peritoneal metastasis of NUGC-4 and SW1990 cells and prolonged their mean survival time in vivo. These findings suggest that CD44H and beta(1) integrin play important roles in the initial attachment of gastric and pancreatic cancer cells to mesothelial cells. Our results suggest that changes in the expression of CD44H and beta(1) integrin in cancer cells is associated with their ability to adhere to peritoneal mesothelial cells, and thus with the peritoneal metastatic ability of gastric and pancreatic cancer cells. Therefore, the expression of CD44H and beta(1) integrin in gastric and pancreatic cancers could be used as prognostic indicators of peritoneal metastasis. It is possible that a treatment strategy that interferes with the functions of CD44H or beta(1) integrin may result in decreased intra-abdominal spread of cancer.

The association of metastasis with the expression of adhesion molecules in cell lines derived from human gastric cancer

Peritoneal dissemination and hepatic metastasis commonly occur after patients with gastric cancer have undergone surgery. The presence of metastasis after surgery is sure to affect the prognosis of patients with gastric cancer. We conducted in vitro and in vivo studies to assess the role of adhesion molecules in this process, using 2 cell lines derived from human gastric cancer. Although both cell lines expressed several adhesion molecules to varying degrees, NUGC-4 cells, which disseminated early after inoculation into the abdominal cavity of nude mice accompanied by the formation of bloody ascitic fluid, predominantly expressed CD44H. However, MKN74 cells, which demonstrated hematogenous metastasis in the liver after inoculation into the spleen of nude mice, strongly expressed the sialyl Lewis(x) antigen (s-Le(x)), but did not express CD44H at all. When the binding of both these cancer cells to human umbilical vein endothelial cells was examined it was found that MKN74 cells adhered more strongly than NUGC-4 cells. The adhesion of cancer cells to endothelial cells was inhibited by treatment with antibodies against s-Le(x) and E-selectin. In the liver metastasis model of nude mice, treatment with anti-s-Le(x) antibodies significantly inhibited the development of MKN74 cell liver metastasis, both in the number of tumor nodules and in liver weight. NUGC-4 cells adhered to monolayers of mesothelial cells more strongly than MKN74 cells. The adhesion of NUGC-4 cells to these cells was partially inhibited by antibodies either against CD44H or the beta 1 subunit of integrin, but was completely blocked by a combination of these 2 antibodies. These antibodies markedly inhibited the dissemination of NUGC-4 cells in the peritoneal cavity of nude mice, and prolonged their mean survival time. These findings suggest that s-Le(x) and E-selectin mediate the adhesion of gastric cancer cells to endothelial cells, and CD44H and beta 1 integrin play important roles in the initial attachment of gastric cancer cells to mesothelial cells. It is possible that compounds that interfere with the function of cell adhesion molecules may decrease the incidence of gastric cancer metastasis.

Causes of rectal incontinence after sphincter-preserving operations for rectal cancer

PURPOSE

Low anterior resection (LAR) is the treatment of choice for middle and high rectal tumors. Even though the rectal sphincter is preserved, some patients show a postoperative loss of rectal continence that may be recovered during follow-up. The purpose of this study was to collect clinical and manometric data before and after LAR to find possible explanations for incontinence.

METHODS

Seventeen continent patients with rectal tumors located 10 cm above the anal verge were selected. Manometry was performed before and three months after surgery and when stable frequency of bowel movement was achieved (mean, 7 months).

RESULTS

Immediately after the operations, 14 of 17 patients showed a certain degree of incontinence but recovered during follow-up; at the end of the study, only two patients reported minor soiling. Resting and squeeze pressures were moderately reduced after surgery and increased during the following six months without regaining preoperative levels. Rectoanal inhibitory reflex was present in 94.4 percent of patients before the operations and in 25 percent of them after surgery, but it was not associated with incontinence. Rectal sensation was significantly reduced, and its recovery was well correlated with decrease in the frequency of bowel movements.

CONCLUSIONS

After LAR, there is a reduction in rectal pressures, suggesting damage to sphincter muscle fibers or innervation. There is also a reduction in rectal sensation related to loss in reservoir capacity, all of which may contribute to incontinence.

Adhesion molecules involved in pleural dissemination of esophageal cancer cells

Pleural dissemination is a common cause of recurrence after surgery of patients with esophageal cancer. Very little is known about the biochemical processes involved in the initial attachment of cancer cells to pleural mesothelial cells. The authors conducted in vitro and in vivo studies to assess the role of adhesion molecules in this process, using 2 cell lines derived from human esophageal cancer. TE-1 cells, which pronouncedly express CD44H, adhered to the monolayers of mesothelial cells more firmly than T.Tn cells. On the other hand, the adhesion of TE-I cells to mesothelial cells was markedly inhibited by antibodies to CD44H or the beta(1) integrin subunit, and more strongly blocked by using a combination of the two antibodies. These antibodies inhibited the dissemination of TE-1 cells in the pleural cavity of nude mice. The findings suggest that CD44 and integrin play important roles in the initial attachment of esophageal cancer cells to mesothelial cells.

Transient hepatofugal portal blood flow after hepatectomy in a patient with cirrhosis: report of a case

We report herein the case of a 60-year-old man who developed hepatic failure with simultaneous transient hepatofugal portal blood flow after undergoing hepatectomy for hepatocellular carcinoma accompanied by cirrhosis with a splenorenal shunt. The transient hepatofugal portal blood flow was detected by color Doppler ultrasonography. Following this case report, the possibility of a relationship between hepatofugal portal blood flow, portal-systemic shunts, and postoperative hepatic failure is discussed.

[Neoadjuvant chemotherapy in high-grade advanced gastric cancer with protracted infusional 5-fluorouracil and consecutive low-dose cisplatin]

Twenty-one evaluable patients with primary gastric cancer/local invasion, liver metastasis and peritoneal metastasis were entered in a pilot study of neoadjuvant chemotherapy that used continuous 24-hour infusion 5-FU, 330 mg/m2/day plus low dose CDDP, 6 mg/m2 daily by bolus infusion d1-5. This regimen was repeated for 4 weeks. The overall response rate was 52%, including one complete and ten partial responses. The response rate of differentiated adenocarcinomas was significantly higher than that of poorly differentiated adenocarcinomas. In 15 patients (71%), gastrectomy and lymphadenectomy could be done after this regimen. chemotherapy-induced downstaging from the initial clinical stage was pathologically found in 5 patients who underwent gastrectomy. Toxicity was primarily hematologic. Leukopenia and thrombocytopenia of grade 3 or 4 occurred in 19% and 14% of patients, respectively. The patients were able to take meals during therapy and preserved good quality of life. Median survival time was 11 months for the cancers with liver metastasis and five of the 8 locally advanced cancers are alive 11 months after the therapy. This therapy was effective for patients with high-grade advanced gastric cancer.

Preoperative embolization of gastric arteries for esophageal cancer

BACKGROUND

We developed a novel treatment of preoperative embolization therapy in an attempt to prevent anastomotic leakage after esophageal resection. We report the results of this new treatment.

METHODS

Preoperative embolization therapy (PET) was performed in 24 cases of esophageal carcinoma. The femoral artery was punctured, and celiac angiography was performed. The left gastric artery and splenic artery underwent embolization. The right gastric artery then underwent embolization at a site beyond the second or third branch to the gastric wall. With a laser flow meter the stomach tissue blood flow was measured before and after construction of the gastric tube, and the change in blood flow was compared.

RESULTS

The average decrease in gastric blood flow was 23% in patients with PET and 65% in patients without PET. Twenty-one (88%) of 24 cases maintained more than 50% tissue blood flow in patients with PET and in 1 (8%) of 12 in patients without PET (p < 0.001 by t test). No serious complications occurred.

CONCLUSIONS

Preoperative embolization therapy is a safe and uncomplicated technique, and tissue blood flow in the stomach was better preserved. This new technique is expected to reduce the frequency of anastomotic leakage after esophageal operation.

Detection of ras gene mutations in perioperative peripheral blood with pancreatic adenocarcinoma

Surgeons wish to know of any correlation between an operation and the incidence of metastasis. In perioperative periods, pancreatic cancer cells were identified by detecting mutant K-ras gene by two-step PCR and RFLP analysis in blood samples taken from peripheral blood. In no case was K-ras point mutation detected in blood before operation, although the mutant hand was observed in all cases at the time the lesion was resected. Surprisingly, in five of ten cases, positive bands were identified just after laparotomy, before we had reached the primary lesion. In almost all cases, mutant K-ras was detected until the fourteenth postoperative day. These findings suggest that cancer cells exist in the circulation, and have a potential for hematogenous metastasis during the perioperative period. In conclusion, surgical stress causes hematogenous dissemination of pancreatic cancer cells, and surgeons should employ the appropriate anti-metastasis therapy in the perioperative period.

Pathogenesis of hepatocellular carcinoma: a review from the viewpoint of molecular analysis

Chronic liver inflammation and hepatic regeneration by infection with hepatitis B (HBV) or C virus (HBC) seem to be important risk factors for hepatocellular carcinoma (HCC). Regarding the hepatocarcinogenesis of HBV DNA integration, it has been variously hypothesized that mechanisms such as the alteration of host chromosomal DNA and transcriptional trans-acting activity of the X gene are activated. On the other hand, integration of HCV virus into chromosomal DNA has not been reported. It is suggested that HCV could replicate more efficiently in noncancerous than in cancerous tissues. Therefore, it might affect some oncogenes or cause an inactivation of tumor suppressor genes in the early stage of HCC. Genetic alterations such as a point mutation and loss of heterozygosity are considered to be late events occurring after tumorigenesis. Regeneration of liver cells through chronic hepatitis increases the incidence of genetic alterations in hepatic cells and/or HCCs in both HBV- and HCV-infected patients.

Surgical treatment for the recurrence of colorectal cancer

We report the results of a retrospective study conducted on patients who developed recurrence following surgery for colorectal cancer, and present a practical plan to improve the survival rates. Of 974 patients who underwent surgery for colorectal cancer in our hospital during the 20 years between 1974 and 1993, 152 developed recurrence, as local recurrence in 70 (7.2%), as liver metastasis in 47 (4.8%), and as pulmonary metastasis in 35 (3.6%). The number of patients who underwent reoperation or curative resection was 54 (77.1%) and 13 (24.1%), respectively, of those with local recurrence, 16 (34.0%) and 6 (37.5%) of those with liver metastasis, and 6 (17.1%) and 6 (100.0%) of those with pulmonary metastasis. The 3- and 5-year survival rates were 13.4% and 8.9%, respectively, after reoperation for local recurrence, 14.4% and 0%, after reoperation for liver metastasis, and 53.3% and 53.3% after reoperation for pulmonary metastasis. Although evaluation was difficult owing to the small number of patients with lung metastasis, resection of a pulmonary lesion resulted in a good outcome. Furthermore, a significant difference in 3- and 5-year survival rates was observed between patients who underwent reoperation and those who underwent conservative treatment, for whom the survival rates were 0% and 0% following local recurrence, 4.6% and 0% following liver metastasis, and 0% and 0% following lung metastasis, at 3 and 5 years, respectively. These findings indicate that aggressive surgery for recurrence may result in a better outcome.

Expression of MRP and mdr1 in human gastrointestinal cancer cell lines: a correlation with resistance against doxorubicin

The mRNA expression of mdr1 and MRP, each of which codes for a transport protein belonging to ATP-binding cassette superfamily and are reported to be responsible for multidrug resistance phenotype, were semi-quantified by RT-PCR in a panel of gastrointestinal cancer cell lines. Although the expression of MRP was predominant in esophageal cancer cell lines, expression of either or both of the genes was detected in all the cell lines tested. Expression of these two genes added together correlated significantly with chemosensitivity against doxorubicin, implicating that expression of both genes should be evaluated in the future analysis of multidrug resistance phenotype. The ID50 values for pirarubicin, although generally lower than the values for doxorubicin, correlated well with the latter, suggesting that the similar phenotype as that for doxorubicin might be responsible for drug resistance against this semisynthetic anthracycline glycoside.

Loss of H19 imprinting in esophageal cancer

Recent articles have reported that loss of imprinting (LOI) of the endogenous gene H19 was frequently found in lung cancer and chorio-carcinoma, common adulthood cancers. Consequently, we examined the status of genomic imprinting of H19 in 29 esophageal and 48 colorectal cancer specimens, and studied its relation to the expression of H19. Of 12 esophageal cancer specimens heterozygous for the RsaI polymorphism, 6 (50%) exhibited LOI of H19, but none of the 18 colorectal cancer specimens heterozygous for the RsaI polymorphism exhibited LOI of H19. The present study suggests that LOI of H19 may play an important role in the pathogenesis of esophageal cancer. Moreover, H19 expression was frequently abundant in both cancers, and all six esophageal cancers carried LOI with overexpressed H19. Therefore, this overexpression of H19 seems to be an important phenomenon for the development of esophageal and colorectal cancer cells.

Efficient adenovirus-mediated gene transfer into human cancer cell lines derived from digestive tract

The efficiency of gene transfer into human cancer cells from digestive tract was evaluated using a replication-deficient recombinant adenovirus (Ad) vector harboring a lacZ gene of E. coli as a reporter gene (AxCALacZ). Average percent X-gal staining of esophageal cancer cell lines was 46%, that of gastric cancer cell lines 82% and that of colon cancer cell lines 70% at 3 days after Ad vector infection. X-gal staining in vitro continued 2 months after infection. By the direct injection of adenovirus vector to the tumors in nude mice, a certain percentage of tumor cells was stained by the X-gal. Colon26 cell line infected with AxCALacZ was implanted in BALB/c mice immunized with AxCALacZ, and tumor growth was suppressed. We presume this was due to anti-adenoviral immunity.

Seasonal variation in blood pressure in normotensive women studied by home measurements

1. The factors influencing the seasonal variation in blood pressure measured at home in normotensive women were examined. 2. Sixteen female subjects (56.3 +/- 7.9 years old, mean +/- SD) measured their blood pressure and pulse rate at home each morning for more than 20 times per month for at least 1.5 years. Blood pressure and body weight were also determined in the office once or twice a month in that period. Monthly means of outdoor and indoor temperatures and daytime length were obtained from the Meteorological Observatory. The single cosinor method was used to evaluate circannual rhythm. 3. We observed a biphasic seasonal variation in self-recorded blood pressure measured at home, environmental temperature and daytime length but found no apparent seasonal variation in body weight and blood pressure measured in the office. The lowest levels of systolic and diastolic blood pressure measured at home were observed in July. The longest daytime length was recorded in June, while the highest outdoor temperature and indoor temperature were recorded in August, indicating that the longest daytime length preceded and the highest environmental temperature lagged behind the lowest level of blood pressure. The shortest daytime length is in December. The lowest outdoor and indoor temperature were observed in January, while the highest levels of self-recorded systolic blood pressure and diastolic blood pressure were in January and December, respectively. Half-amplitudes of self-recorded systolic and diastolic blood pressure were 2.6 +/- 1.0 mmHg and 2.0 +/- 0.8 mmHg, respectively. 4. These findings indicate the importance of a seasonal effect, i.e. daytime length and the environmental temperature, on the blood pressure of individuals.

[Epidemiological study of osteoporosis]

An epidemiological investigation of osteoporosis was carried out in a community in which fishing is the primary industry, and correlations were investigated between the bone mass and various risk factors for osteoporosis and biochemical findings. In 852, who could be examined directly, of the 3541 males and females aged 40 years or above living in Nansei Town, Watarai District, Mie Prefecture, the age, sex, height, body weight, years after menopause, married or unmarried, area of residence, daily activity, and intakes of milk, fish, and alcohol were studied by direct oral inquiry, and the serum calcium, inorganic phosphorus, alkaline phosphatase, and total protein were measured. The subjects were divided into a decreased bone mass group who showed grade I or more advanced loss in bone mass and a normal bone mass group who showed no or only slight loss in bone mass on the basis of microdensitometry (MD). Eighty-two subjects (9.6%) were classified as the decreased bone mass group. Items that showed a close correlation with sigma GS/D, which is an index of bone density, were age, years after menopause, serum alkaline phosphatase level, height, and body weight in females, age and serum alkaline phosphatase level in males. In the decreased bone mass group, 79 of the 82 subjects were females. Significant differences were observed between the decreased bone mass group and the normal bone mass group in age, years after menopause, serum alkaline phosphatase level, height, and body weight. From these results, a high age, being a female, low height, and a low body weight were found to be factors correlated with osteoporosis. Also, the bone mass was correlated with the serum alkaline phosphatase level and years after menopause.

[A synchronous double cancer of esophagus and stomach treated with 5-fluorouracil and consecutive low-dose cisplatin]

We report a case of double cancer of esophagus and stomach treated with 5-fluorouracil and consecutive low-dose cisplatin. The patient was a 58-year-old man with liver cirrhosis. Using upper gastrointestinal fiberscopy, a superficial depressed lesion (O-IIc) in the middle thoracic part of the esophagus and Borrmann 2 type lesion in the fundus of the stomach were also detected. Microscopic examination of the biopsy specimen revealed moderately differentiated squamous cell carcinoma and adenocarcinoma. But laparotomy could not be done due to impaired liver function (KICG 0.051, ICGR15 45.2%). The patient was treated for 28 days with continuous 24 hour infusion 5-FU, 250 mg/body/day plus low dose CD-DP, 10 mg/body daily by bolus infusion d1-5, 8-12, 15-19, 22-26. One month after the chemotherapy, both the gastric cancer and the esophageal cancer were remarkably reduced (diagnosis: PR), and showed no malignancy in the histology. There was no change in the histological findings of the esophageal lesion at 31 months after the chemotherapy. This therapy is effective for patients with gastric cancer and esophageal cancer.

[General pharmacological study of iodixanol, a new non-ionic isotonic contrast medium]

The general pharmacological study of iodixanol, a non-ionic isotonic contrast medium, was conducted. 1) Iodixanol administered intravenously over a dose range of 320 to 3,200 mgI/kg had little or no effect on the general behavior, spontaneous locomotor activity, hexobarbital sleeping time, pain response, electroshock- or pentylenetetrazol-induced convulsion (mouse), EEG or body temperature (rabbit), gastrointestinal propulsion (mouse) or skeletal muscle contraction (rabbit). Iodixanol had no specific interaction with acetylcholine, histamine, serotonin, nicotin, BaCl2 (ileum), methacholine (trachea), isoprenaline (atrium) or oxytocin (pregnant uterus), nor had any effect on spontaneous contractility (atrium and uterus), or transmural electrostimulation-induced contractility (vas deferens) at concentrations of < or = 3.2 x 10(-3) gI/ml in vitro. Iodixanol had no effect on the cardiovascular system of dog, except that it increased femoral blood flow and respiratory rate at doses of > or = 1,000 mgI/kg. Iodixanol at 3,200 mgI/kg i.v. reduced urine output with a decrease in Na+ and Cl- excretion, whereas at 320 mgI/kg i.v., it slightly increased urine output (rat). 2) Injections of iodixanol into the cerebroventricular (0.96, 9.6 mgI/mouse and 3.2, 32 mgI/rat), left ventricular (1,920, 6,400 mgI/dog) or coronary artery (640, 1,920 mgI/dog) had no conspicuous effect on the central nervous system or the cardiovascular system, respectively. There was no marked difference among iodixanol, iohexol and iopamidol in this respect. Vascular pain during injection into the femoral artery (300-320 mgI/guinea pig) appeared to be less intense with iodixanol, compared with the other contrast media iohexol and iopamidol. These results suggest that intravenous injection of iodixanol is relatively free from pharmacological activity, and effects of iodixanol on the central nervous system (intracerebroventricular injection) and cardiovascular system (intra-left ventricular and -coronary injections) are comparable to those of iohexol and iopamidol. Furthermore, intra-femoral injection of iodixanol has less of a tendency to produce vascular pain than those of iohexol and iopamidol.

Protective effects of kampo medicines and baicalin against intestinal toxicity of a new anticancer camptothecin derivative, irinotecan hydrochloride (CPT-11), in rats

In clinical use, irinotecan hydrochloride (CPT-11; 7-ethyl-10-[4-(piperidino)-1-piperidino]carbonyloxycamptothecin), a novel antitumor agent, causes a relatively high incidence of severe forms of diarrhea. We investigated whether baicalin, an inhibitor of beta-glucuronidase, which deconjugates the glucuronide of the active metabolite of CPT-11, SN-38 (7-ethyl-10-hydorxycamptothecin), and Japanese herbal medicines (Kampo medicines) which contain baicalin can ameliorate CPT-11-induced intestinal toxicity in rats. CPT-11 (60 mg/kg i.v. once daily for 4 consecutive days) induced intestinal toxicity characterized by diarrhea, loss of body weight, anorexia and disruption of intestinal epithelium. Treatment with baicalin (25 mg/kg p.o. twice daily) or Kampo medicines (TJ-14 and TJ-114; 1 g/kg p.o. twice daily) from the day before to 4 or 10 days after the start of CPT-11 administration resulted in significantly decreased weight loss, improved anorexia and delayed onset of diarrheal symptoms. Histological examination revealed that Kampo medicine-treated animals had less damage to the intestinal epithelium and that damage was repaired more rapidly than in control rats. These results suggest that the prophylactic use of Kampo medicines (TJ-14 and TJ-114) may be of value against CPT-11-induced intestinal toxicity.

Stretch-induced enhancement of contractions in uterine smooth muscle of rats

1. We studied the effect of servo-controlled stretch of smooth muscle strips from rat uterus on tension and intracellular Ca2+ concentration ([Ca2+]i, using fura-2 as an indicator) at 30 degrees C. 2. When quiescent uterine muscle strips were stretched at a ramp time of 0.5 s by multiples of 5% of the resting muscle length (L0) up to 40%, forty-two out of sixty muscle strips responded with a transient active contraction and a [Ca2+]i increase. The minimum excursion of stretch required for contraction was 26.3 +/- 7.5% of L0 (mean +/- S.D.). The peak response had an all-or-none property and was almost independent of the duration of stretch. 3. Stretches of 30 or 35% of L0 induced contraction in most cases when rapidly applied in 0.2-0.5 s, but slowly applied stretch (ramp duration of 5-10 s) rarely induced contraction. 4. The stretch-induced response was inhibited by the removal of extracellular Ca2+ or by the addition of 10 nM nicardipine. However, it was unaffected by 1 microM tetrodotoxin, 1 microM atropine or by 10 microM cyclopiazonic acid, an inhibitor of Ca2+-ATPase in intracellular Ca2+ stores. 5. When a stretch of 15-35% of L0 was applied during the relaxation phase of 10 nM oxytocin-induced rhythmic contractions, the first contraction after the stretch occurred earlier than that expected from the control rhythm. However, the frequency of the subsequent rhythm returned to almost the control level even during continued application of stretch, although the half-width of rhythmic contractions was increased during stretch. 6. The present study demonstrates that stretch of uterine muscle induces a transient contraction due to Ca2+ influx, which is myogenic and dependent on the excursion and velocity of stretch. The all-or-none property of the stretch-induced contractions suggests initiation of Ca2+ spikes. Furthermore, stretch modulates the oxytocin-induced rhythmic contractions.