The long-term effects of pitavastatin on blood lipids and platelet activation markers in stroke patients: impact of the homocysteine level

To examine the impact of the plasma homocysteine level on the anti-atherosclerotic effects of pitavastatin treatment, we retrospectively examined 59 patients who had a history of stroke and had been prescribed pitavastatin for the treatment of dyslipidemia at the Neurology department of Toho University Ohashi Medical Center Hospital. The patients were classified into two groups according to their homocysteine levels. Carotid artery plaque progression was determined before and after pitavastatin treatment. Plasma levels of high-sensitivity C-reactive protein, platelet molecular markers, and von Willebrand factor were measured. Pitavastatin treatment had beneficial effects on the lipid profiles of these patients and slowed atherosclerosis progression. These effects were observed in both the high and low homocysteine groups. Proactive lipid intervention using pitavastatin may inhibit the progression of atherosclerosis and contribute to secondary prevention of stroke in high-risk patients. We conclude that this statin could inhibit progression at any stage of disease and should therefore be proactively administered to these patient groups, regardless of disease severity.

The Course of Incidental Intraorbital Cavernous Hemangioma in a Patient with Myasthenia Gravis Treated with Cyclosporine: A Case Report

A 69-year-old woman presented with generalized myasthenia gravis and a left orbital cavernous hemangioma (OCH), which elevated the optic nerve and displaced the external eye muscles. Cyclosporine treatment induced a gradual size reduction in the OCH, and consequently contributed to improved external ocular symptoms in combination with immunosuppressant effects.

[A case of Rh-incompatible transfusion in critical hemorrhage]

A 66-year-old man was injured in the traffic accident and showed the signs of hemorrhagic shock. His blood type was Rh negative O. As excessive bleeding was going on, we decided to transfuse 8 units of Rh-incompatible type O red blood cell (RBC) without performing cross match test according to the guideline for treatment of critical bleeding. Though we were aware of the risks of that treatment, no hemolytic reaction nor any other side effect was observed during and after the transfusion. Anti-Rh antibody was not developed either while Anti-Rh immunoglobulin was not given to him. His blood type has been proved to be Del type red blood cell. We conclude that transfusion of Rh-incompatible blood in patient with critical hemorrhage should be encouraged to save life.

Traumatic cerebral aneurysm associated with a contralateral traumatic carotid cavernous fistula. A case report

SUMMARY

This report documents the management of a traumatic carotid aneurysm (TCA) with a traumatic carotid-cavernous fistula (T-CCF) of the contralateral internal carotid artery (ICA) following a closed head injury. A 38-year-old man presented with severe traumatic subarachnoid hemorrhage and pneumocephalus due to a severe head injury. Four months after the accident, the patient presented with clinical symptoms of exophthalmos and retroorbital bruit. Cerebral angiography showed a TCA of the IC-PC region, which coexisted with a contralateral T-CCF. Both lesions were successfully managed with an endovascular treatment using coils to isolate a fistula from the ICA, and direct surgical trapping of the intracranial ICA to eliminate a TCA. Post-operative angiography revealed a good cross-flow through the anterior communicating artery from the contralateral ICA, which was completely obliterated by the T-CCF. No additional surgical or endovascular procedure for traumatic vascular injuries was required. The patient remained asymptomatic during the clinical follow-up period of 24 months. The goal of traumatic carotid injuries is the selective elimination of the vascular pathologic injury with asymptomatic state, using direct surgery and/or an endovascular treatment.

Demonstration of R factors from Pseudomonas aeruginosa

Sixty strains of Pseudomonas aeruginosa were selected from our clinical stock cultures and used as donors of drug resistance to examine the presence of R factors. They were highly resistant to one or more of six drugs including tetracycline (TC), chloramphenicol (CM), streptomycin (SM), sulfanilamide (SA), carbenicillin (CPC), and kanamycin (KM). Three FP(-), auxotrophic mutants of P. aeruginosa were used as recipients, which had been made resistant to either rifampin (RMP) or KM by in vitro mutation. Each donor was mated with each of the three recipients, and 45 strains were found to transfer their resistance to one or more recipients. A second series of conjugation experiments using 45 exconjugants as donors showed that 23 could transfer their resistance. We conclude that these strains carry R factors that are transmissible to one or more recipients. Eleven carried resistance to (TC.CM.SM.SA.CPC), nine to (TC.CM.SM.SA), one to (TC.CM.SA.CPC), one to (TC.CM.SA), and one to (SM). All of these R factors could not be transmitted to other species belonging to the family Enterobacteriaceae.

Modulation of human c-mpl gene expression by thrombopoietin through protein kinase C

The c-Mpl, thrombopoietin (TPO) receptor specificially controls megakaryocytic growth and differentiation. TPO increased the c-mpl promoter activity determined by a transient expression system using a vector containing the luciferase gene as a reporter in the human megakaryoblastic cell line CMK. The maximal promoter activity of c-mpl was obtained 24 hr after pretreatment with TPO for 3 hr and then declined with time. This increase was completely abolished by protein kinase C (PKC) inhibitors (GF109203, calphostin C and H7). Phorbol 12-myristate 13-acetate (PMA) treatment led to an increase in c-mpl promoter activity. These results demonstrate that the promoter activity of c-mpl is modulated by transcription through a PKC-dependent pathway.

Effect of gravity change on the production of thrombopoietic growth factors

It is reported that the stay in the space develops anemia, thrombocytopenia, and altered function and structure of red blood cell. The mechanism of these abnormalities was not clarified yet. The cloning of the thrombopoietin (TPO), followed by the analysis of TPO and c-mpl (its cellular receptor) knockout mice confirmed its role as the primary regulator of thrombopoiesis. TPO has been shown to stimulate both megakaryocyte colony growth from marrow progenitor cells and the maturation of immature megakaryocyte to form functional platelet. This process includes the massive cytoskeletal rearrangement, such as proplatelet formation and fragmentation of proplatelet. In this study we have focused on the production of thrombopoietic growth factors in mice those were exposed to gravity change by parabolic flight (PF).

Primary sclerosing cholangitis successfully treated by resection of the confluence of the hepatic duct

Primary sclerosing cholangitis (PSC) is a cholestatic disease characterized by chronic inflammatory fibrosis of the extra- and intrahepatic bile ducts. Although the prognosis of patients with PSC was believed to be poor, some patients have not experienced the expected rapid clinical progression. A 51-year-old man with PSC was initially hospitalized for jaundice. Laboratory data showed low levels of the complement components C3, C4, and CH50. Percutaneous transhepatic biliary drainage was performed. Cholangiography revealed complete obstruction of the common bile duct below the confluence of the cystic duct. The confluence of the hepatic duct was resected and it was reconstructed by hepaticojejunostomy for palliation of the obstructive jaundice. Increased thickness of the walls of the common bile duct, right hepatic bile duct, and gallbladder was observed. Histopathological examination of the resected specimen revealed periductal fibrosis, with an onion-skin-like appearance. The patient is currently doing well, approximately 7 years after the surgery, without any signs of PSC recurrence. In this extraordinary patient, the laboratory data for C3, C4, and CH50 showed a complete return to normal levels. The positive results in this patient suggest that resection of the confluence of the hepatic duct may be an effective surgical treatment for noncirrhotic PSC patients who have dominant extrahepatic strictures.

Effect of gravity change on thrombopoiesis in mice

It is reported that the stay in the space develops anemia, thrombocytopenia, and altered function and structure of red blood cell. The mechanism of these abnormalities was not clarified yet. Therefore, it is necessary to elucidate the mechanism of the effect of the gravity change on the thrombocytopoiesis, which plays the important role for the hemostasis, using animal models. The cloning of thrombopoietin (TPO), followed by the analysis of TPO and c-mpl (its cellular receptor) knockout mice confirmed its role as the primary regulator of thrombopoiesis. TPO has been shown to stimulate both megakaryocyte colony growth from marrow progenitor cells and the maturation of immature megakaryocyte to form functional platelet. This process includes the massive cytoskeletal rearrangement, such as proplatelet formation and fragmentation of proplatelet. In this study we have focused on the thrombopoiesis in mice those were exposed to gravity change by parabolic flight (PF).

Current status of bacterial contamination of autologous blood for transfusion

Autologous transfusion, although not without risk, does decrease the risk of transmitted diseases via homologous transfusion. However, strict quality control is required for autologous transfusion. In Japan, a recent enactment requires that written informed consent be obtained prior to blood transfusion, which therefore requires that clinicians provide sufficient explanation of the risks involved with this procedure. To the best of our knowledge, this is the first study to comprehensively evaluate the manner in which the safety of autologous blood transfusion can be compromised by bacterial contamination. For a 24-month period, between April 1996 and March 1998, bacterial contamination of all kinds of autologous blood samples was tested by sampling the culture immediately prior to transfusion. Subculturing, identification and susceptibility testing of the isolates were performed. From the 287 units of all kinds of autologous blood transfused, 18 were culture positive (6.3%). Positive blood cultures were obtained in two of the 59 units (3.4%) of autologous transfusion donated preoperatively (ATDP) that was infused intraoperatively, in three of the 117 units (2.6%) of hemodilution/autologous transfusion (HAT) and in three of the 81 (3.7%) of ATDP infused postoperatively. There was a high percentage (33.3%) of positive blood cultures in the cases of intraoperative blood salvage (IOBS). The total rate of positive blood cultures was 6.3% including IOBS and 3.1% excluding IOBS. The most common microorganism isolated from autologous blood was coagulase-negative Staphylococci in 12 of 18 culture-positive units (66.7%). Alpha Streptococcus uiridans was isolated in 2 units (11%) and Staphylococcus aureus was isolated in 1 unit (5.5%). However, none of the patients who received the culture-positive autotransfusion blood showed clinical signs or laboratory findings of bacteremia. Safe ATDP is threatened by bacterial contamination that can be introduced by numerous sources, such as the donors' blood, the skin at the site of venipuncture, the environment and the phlebotomist's finger. In the cases of IOBS, protection against bacterial contamination at the surgical site is crucial. Here we discuss the relevance of our findings to the efforts to minimize the risks of contamination associated with autologous blood transfusion; risks that must be communicated to the patient in the process of informed consent. Continued research is required to identify the safest method of autologous blood transfusion.

Endovascular Management of Intradural Berry Aneurysms. Review of 203 Consecutive Patients Managed between 1993 and 1998 Morphological and Clinical Results at Mid-Term Follow-up

SUMMARY

Endovascular management of intracranial arterial aneurysms (AA) is well described and performed by many teams. The aim of this work is to review a series of consecutive cases treated in our institution and to compare to the data available in the literature. 225 AA were seen in Bicêtre between 1993 and 1998 in 203 patients. 201 of them (in 180 patients) were treated by our group. The endovascular treatment, its indications, results and complications have been reviewed and studied. The clinical follow-up of the patients has been evaluated. A female dominance was noted (64.5%) with a mean age of patients of 44.3 years. 65.6% of patients were treated in the acute phase after intracranial haemorrhage, 72% of them being Hunt and Hess grade 1 or 2. Most of these AA (73.6%) were located in the anterior circulation. In 86.1% of cases the AA was smaller than 10 mm. 85.6% of the AA needed only one session of endovascular therapy. No mortality occurred in the group of unruptured AA. Overall management mortality was 11% in ruptured AA (3.5% in HH1-2, 30.3% in HH3-5).Technical or transient complications occured in 11.6% of cases, but permanent morbidity was seen in 3.1% of cases. Control angiograms were performed 3 months and one year after therapy. In doubtful cases a control at 6 months was also performed. 100% occlusion rate was noted in 60.8% of cases; 22.8% of AA were occluded between 90-99%, and 13.3% between 80-90%. Only 3.1% of AA had an occlusion rate of less than 80%. One patient with a ruptured basilar tip AA which was partially coiled regrew and rebled three months after. The patient declined the recommended complementary surgery. Clinical follow up of patients with ruptured AA treated by embolisation shows satisfactory results with 8.5% of GOS 1-2, 3.4% of GOS 3-4, and 11% of GOS 5 (mortality). Overpacking of the AA may not be necessary to protect patients from (re)bleeds over time. The related technical risks and increased costs of dense overpacking do not seem justified. Secondary thrombosis of the ruptured AA after coiling is more often seen than coil compaction. Analysis of the AA architecture and recognition of false aneurysms are mandatory in order to obtain good clinico-morphological logical results.

Successful resection of a liver metastasis from gastric leiomyoblastoma: report of a case

A 20-year-old woman was referred to our hospital for detailed investigation of a gastric submucosal tumor. A leiomyoma was preoperatively diagnosed and laparoscopic-assisted enucleation was performed. The resected tumor was 4 x 3 x 1.5 cm in size and postoperative histological examination identified it as a gastric leiomyoblastoma. Therefore, a secondary resection in the form of a distal gastrectomy was carried out. No tumor cells were found in the gastric specimen or in the lymph nodes; however, 5 months after the operation, an abdominal computed tomography scan revealed a recurrence in the liver, and she was readmitted for further examinations. The lesion was diagnosed as a single liver metastasis from the gastric leiomyoblastoma and successfully resected. The histopathological findings of the liver tumor resembled those of the primary gastric tumor. Her postoperative course was uneventful and she has been well, without any evidence of recurrence, to date. Only 12 other cases of leiomyoblastoma of the stomach with liver metastasis have been reported in Japan, all of which were associated with a very poor prognosis. Therefore, patients with this unusual disease entity should be carefully followed up after resection of the primary tumor.

Drainage for acute pancreatitis

In severe acute pancreatitis, the drainage of activated pancreatic enzymes, infectious substances and necrotic tissue from the abdominal cavity is critical, especially after the operation. We use Faycon drainage tubes together with multi-use feeding tubes. Just after the operation, normal saline is added through the feeding tube and the Faycon drainage tube is suctioned continuously. Irrigation is necessary for more than two weeks.

Measurements of cortical cellular pH by intracranial tonometer in severe head injury

OBJECTIVE

To evaluate the cortical cellular damage in acute severe head injury, we measured the cortical cellular pH by using an intracranial tonometer made in our institution.

DESIGN

Prospective, 3.5-yr data collection.

SETTING

University hospital trauma intensive care unit.

PATIENTS

Severely head-injured patients (n = 29) with Glasgow Coma Scale score <8.

INTERVENTION

Routine emergency neurologic procedure.

MEASUREMENTS AND MAIN RESULTS

We made 98 measurements of cortical cellular pH by intracranial tonometer in 29 severely head-injured patients in the acute phase. Each patient's intracranial pressure was recorded, and in 16 patients, the saturation of jugular venous oxygen was monitored. The outcome at 6 months after injury was significantly better in patients having a cortical cellular pH of >7.2 than those with <7.2. The cerebral perfusion pressure and cortical cellular pH correlated significantly (p < .0001).

CONCLUSIONS

Our study suggests the usefulness of measurement of cortical cellular pH by intracranial tonometer for evaluating the severity of focal anaerobic cerebral metabolism and predicting patient prognosis.

HIV infection of megakaryocytic cell lines

Thrombocytopenia is a common hematologic disorder in HIV infection and occurs in both asymptomatic and AIDS patients. An autoimmune mechanism has been postulated for the platelet destruction associated with some forms of thrombocytopenia. However, recent studies revealed that megakaryocytes are susceptible to HIV infection and suggested the possibility that HIV can directly impair the platelet production from megakaryocytes. This study was designed to characterize the HIV receptor expression in megakaryocytic cells and the responsiveness to HIV infection. Four different megakaryocytic cell lines at different stages of differentiation were established from the peripheral blood of different individuals with hematologic malignancies. CMK and CMY cells (differentiated cell lines) expressed CD4, but CMS and CTS cells (poorly differentiated cell lines) did not. The HIV coreceptor CXCR4 was also expressed in CMY and CMK cells. HIV-1 (HTLV-IIIB) replicated in CMY cells persistently but not in other three cell lines. CMY cells as well as CMK cells were also susceptible to the lytic infection of HIV-2 (LAV2). Pretreatment of the CMY cells with anti-CD4 antibody inhibited the infection by both HIV-1 and HIV-2. Our results indicate that mature megakaryocytic cells express CD4 along with HIV coreceptors and are susceptible to HIV infection.

Change of liver function in hypertrophying lobe of rabbit liver after portal branch ligation

Preoperative portal embolization (PE) is useful for the prevention of postoperative liver failure after extended hepatectomy. However, clinical evaluation of liver function in the hypertrophying lobe after PE has not been studied. Here we report functional changes in the hypertrophying lobe using a 80% portal-branch-ligation rabbit model. Liver function was evaluated by the expression of liver-specific genes detected by Northern blot analysis and plasma disappearance rate of indocyanine green (ICG). The weight of the unligated lobe after portal ligation increased about twofold on the 7th postoperative day (POD) and about threefold on the 14th POD. The mRNA levels of the liver-specific genes (albumin, aldolase B, and tyrosine aminotransferase) in the unligated lobe decreased to about 50% on the 1st POD and returned to the preoperative levels on the 7-14th POD. In contrast, the expression of histone H2B mRNA increased on the 3rd-7th POD. The plasma disappearance rate of ICG (K-ICG) in the rabbit that has only the unligated lobe did not significantly change during the first 7 days, but then improved and recovered to 80% of that in the rabbit that has whole liver on the 14th POD. These results indicate that liver function of the hypertrophying lobe after portal branch ligation does not increase during the first 7 days despite an increase in liver weight. This finding suggests that the compensatory hypertrophying liver is enlarging without functional augmentation in the early period after PE.

The role of skeletal muscle and liver on lactate metabolism during hypoxia in rats

PURPOSE

This study was planned to investigate whether the skeletal muscle and liver produce or consume lactate under hypoxic conditions.

METHODS

Wister rats were anesthetized and mechanically ventilated. Microdialysis probes were inserted into the rat skeletal muscle and liver, and arterial cannulation was performed. Hypoxia was induced for 30 min by the inhalation of 10% oxygen in nitrogen. Interstitial lactate concentrations in the skeletal muscle and liver were measured using an in vivo microdialysis method before, during, and after hypoxic hypoxia. The blood lactate concentration, mean arterial blood pressure, and blood gas were also measured.

RESULTS

Before hypoxia, there was no significant difference among the blood lactate concentration and interstitial lactate concentrations of the skeletal muscle and liver. During hypoxia, arterial oxygen tension decreased to 34.2 +/- 1.3 mmHg, and the lactate concentrations in these tissues increased significantly in comparison to the control values. However, the lactate concentrations in the skeletal muscle and liver interstitium were significantly lower than that in the blood, with the peak lactate concentration in the skeletal muscle interstitium being only one-third of that in the blood. After correction of hypoxia, the blood lactate concentration decreased to levels comparable to the skeletal muscle and liver interstitial lactate concentrations.

CONCLUSION

It is suggested that the skeletal muscle as well as the liver may consume lactate under hypoxic hypoxia.

Experimental study on the bilirubin metabolism after major hepatectomy: alterations in the proportions of bile bilirubin subfractions

Bilirubin metabolism after major hepatectomy was investigated experimentally using rats. After a 70% and an 80% hepatectomy, proportions of bilirubin diglucuronide (BDG) decreased, and reversely, those of bilirubin monoglucuronide (BMG) increased. These changes were even more remarkable after an 80% hepatectomy. Parallel to the decrease in the proportions of BDG, the concentrations of uridine diphosphoglucuronic acid (UDP-GA) in the remnant liver decreased, and there was a significant correlation between the changes in BDG and UDP-GA. Although UDP-glucuronyltransferase (UDP-GT) activity and energy charge of the remnant liver also decreased after surgery, these decreases were mild and returned to the control level earlier than BDG. And there was no significant correlation between the changes in BDG and those in UDP-GT activity and energy charge. In this study, the decrease of the proportions of BDG in the bile juice was long term after partial hepatectomy and the period of the decrease became longer according to the augmentation of the volume of the hepatectomized liver. We clarified that the process of the UDP-GA production was inhibited after hepatectomy and the decrease of the proportions of BDG was derived from a deficiency of substrate of the glucuronidation, UDP-GA.

Results of surgical treatments and prognostic factors for hepatic hilar bile duct cancer

Results of surgical treatments for 57 patients who underwent resection for hepatic hilar bile duct cancer between 1984 and 1997 were studied. Bile duct resection was performed in eight patients, and combined resection of bile duct and liver was performed in 49 patients, of whom vascular reconstruction was added in 15 patients and pancreatoduodenectomy (PD) in six patients. All the operations of bile duct resection that were not combined with hepatectomy were non-curative. In the patients who underwent combined resection of the bile duct with liver, outcomes of the patients with well-differentiated adenocarcinoma were better than those with other lower-grade tumors. The factors related to the degree of tumor extension, such as serosal invasion, lymph node metastasis, lymphatic vessel invasion, perineural invasion, venous vessel invasion, and vascular involvement, were other factors which significantly influenced the survival. Curative resection yielded significantly better results than non-curative resection. Of all these variables, good tumor differentiation and vascular involvement were recognized as important prognostic factors by multivariate analysis. Most of the postoperative deaths were encountered in patients who underwent additional operations to hepatectomy, such as vascular reconstruction or PD. Improvement of surgical techniques and perioperative care has yielded better outcomes of vascular reconstruction. However, the application of hepatopancreatoduodenectomy should be limited due to poor outcomes of widespread bile duct cancer of which the histological grade is usually low. Whereas prognosis of bile duct cancer involving the hepatic hilus is mainly determined by the biologic characteristics of the tumor, surgeons should consider the fact that most patients die of local recurrence regardless of the biologic character of the tumor when curative resection is not performed.

Altered biliary bilirubin profile in patients with persistent hyperbilirubinaemia after hepatic resection: analysis of bile bilirubin subfractions by high-performance liquid chromatography

Subfractions of bilirubin in bile, obtained via biliary drainage tubes from 23 patients who had undergone radical surgery for bile duct cancer, were analysed by high-performance liquid chromatography for 14 days after surgery. Five principal conjugated bilirubins were resolved: bilirubin diglucuronide (BDG); bilirubin monoglucuronide monoglucoside (BGG); bilirubin monoglucuronide monoxyloside (BGX); and two isomers of bilirubin monoglucuronide. After surgery, depression in concentration of BDG and elevation of BGG and BGX were found. These alterations were of higher magnitude in patients who had undergone hepatectomy, and especially prolonged in patients with hyperbilirubinaemia. These results suggest that the alteration in proportions of bilirubin conjugates might be a cause of hyperbilirubinaemia after hepatectomy.

Binding and regulation of thrombopoietin to human megakaryocytes

Thrombopoietin (TPO, c-Mpl ligand) is considered to play an important role in the regulation of megakaryocytopoiesis and platelet production by activating the cytokine receptor c-Mpl. We have examined the binding of 125I-TPO to the human megakaryocytic cell line, CMK, and to primary human megakaryocytes. Scatchard analysis of TPO binding to its cognate receptor in megakaryocytic cells suggested the existence of a single class of c-Mpl receptors. CMK cells exhibited 1223 receptors per cell with a dissociation constant (Kd) of Kd = 223 pM, whereas primary human megakaryocytes exhibited 12140 receptors per cell and a dissociation constant of Kd = 749 pM. The pretreatment of CMK cells and primary bone marrow megakaryocytes with TPO resulted in a decreased binding of TPO to the c-Mpl receptors. This down-regulation was observed within 3 h and was not inhibited by cycloheximide. Phorbol ester, an activator of protein kinase C, also inhibited TPO binding to the c-Mpl receptors by reducing the number of these receptors. The pretreatment of CMK cells with IL-3, IL-6 and DMSO, all of which induced the differentiation of CMK cells, did not affect the binding of TPO to the c-Mpl receptors. These results suggest an additional mechanism, where protein kinase C may help to regulate the binding of TPO to these cells.

Establishment of a new human megakaryoblastic cell line, CMY, with chromosome 17p abnormalities

A new megakaryoblastic cell line CMY was established from a Down's syndrome patient suffering from acute megakaryoblastic leukemia. The karyotypes of CMY showed deletion of chromosome 17 or the translocation of 17p, whereas the blasts of the patient did not reveal these abnormalities of chromosome 17 by conventional karyotype analysis. Blasts of the patient failed to respond to chemotherapy and complete remission could not be attained. The abnormalities of 17p became progressively predominant in the patient. These results suggest that the blasts of a minor clone which had the abnormalities of chromosome 17p might have existed in the patient from the beginning and CMY was established from the minor clone. Investigation of p53 gene by PCR-SSCP analysis revealed that blasts of the patient showed normal patterns, while CMY showed an abnormally migrating band in exon 5 alone. This result suggests that another novel oncogenic factor(s) besides p53 might be present on chromosome 17p and other tumor suppresser genes need to be studied.

Therapeutic efficacy of BO-3482, a novel dithiocarbamate carbapenem, in mice infected with methicillin-resistant Staphylococcus aureus

The in vivo activity of BO-3482, which has a dithiocarbamate chain at the C-2 position of 1beta-methyl-carbapenem, was compared with those of vancomycin and imipenem in murine models of septicemia and thigh infection with methicillin-resistant Staphylococcus aureus (MRSA). Because BO-3482 was more susceptible than imipenem to renal dehydropeptidase I in a kinetic study of hydrolysis by this renal enzyme, the therapeutic efficacy of BO-3482 was determined during coadministration with cilastatin. In the septicemia models, which involved two homogeneous MRSA strains and one heterogeneous MRSA strain, the 50% effective doses were, respectively, 4.80, 6.06, and 0.46 mg/kg of body weight for BO-3482; 5.56, 2.15, and 1.79 mg/kg for vancomycin; and >200, >200, and 15.9 mg/kg for imipenem. BO-3482 was also as effective as vancomycin in an MRSA septicemia model with mice with cyclophosphamide-induced immunosuppression. In the thigh infection model with a homogeneous MRSA strain, the bacterial counts in tissues treated with BO-3482-cilastatin were significantly reduced in a dose-dependent manner compared with the counts in those treated with vancomycin and imipenem-cilastatin (P < 0.001). These results indicate that BO-3482-cilastatin is as effective as vancomycin in murine systemic infections and is more bactericidal than vancomycin in local-tissue infections. The potent in vivo activity of BO-3482-cilastatin against such MRSA infections can be ascribed to the good in vitro anti-MRSA activity and improved pharmacokinetics in mice when BO-3482 is combined with cilastatin and to the bactericidal nature of the carbapenem.

Induction of polyploidization in the human erythroleukemia cell line (HEL) by protein kinase inhibitor (K252a) and the phorbol-ester TPA

Endomitosis (polyploidization) is a distinctive feature of megakaryocyte differentiation. We examined this mechanism in an erythromegakaryocytic cell line, HEL, using a protein kinase inhibitor K252a or a phorbol-ester TPA. HEL cells treated with K252a showed a marked increase in the proportion of CD41 positive cells and polyploid cells as well as in cellular size and nuclear size. TPA showed similar results but induced multi-nucleation instead of enlargement of nuclear size. K252a added at the G1/S boundary phase did not inhibit the first and second round DNA synthesis, but inhibited cell division. K252a did not inhibit the expression of genes involved in mitosis such as cyclin B, cdc25B and cdc2, in the first round S phase. However, the cyclin B associated Cdc2 kinase activity needed for mitosis during the G2/M phase was reduced by K252a. TPA delayed DNA synthesis and expression of these genes, and suppressed Cdc2 kinase activity in the second round G2/M phase. These results suggest that the polyploidization induced by K252a results from inhibiting mitosis possibly caused by suppression of Cdc2 kinase activity. TPA may induce the multi-nucleation through a different mechanism.

Measurement of nitric oxide in the rat cerebral cortex during hypercapnoea

Changes in nitric oxide (NO) concentration and cerebral blood flow (CBF) in the parietal cortex during hypercapnoea were investigated in anaesthetized rats, using a NO-selective electrode and laser Doppler flowmetry. When hypercapnoea was induced by inhalation of 5% CO2 for 10 min, both the NO concentration and CBF increased. After administration of 7-nitroindazole, a neuronal NO synthase (nNOS) inhibitor, both the basal NO and CBF decreased, and responses to hypercapnoea were also significantly suppressed by 70.1% and 73.2%, respectively, compared with the control state. These results suggest that NO derived from nNOS is involved not only in maintaining resting cerebral circulation but also in regulating CBF response during hypercapnoea.

In vitro and in vivo evaluation of BO-2727 against imipenem- and/or meropenem-resistant Pseudomonas aeruginosa

The in vitro and in vivo activity of BO-2727, a carbapenem antibiotic, against resistant clinical isolates of Pseudomonas aeruginosa was studied. The geometric mean MICs against three groups of clinical isolates resistant to imipenem, meropenem and both carbapenems were 4.28, 4.08 and 5.44 micrograms/ml, respectively. BO-2727 also inhibited multiply antibiotic resistant isolates and laboratory mutants including a nalB-type mutant, which showed resistance to antibiotics such as imipenem, meropenem, ceftazidime, and/or ciprofloxacin, at less than 1.56 micrograms/ml. Overall, BO-2727 was 4-fold more active than biapenem, meropenem, panipenem and imipenem with an MIC90 of less than 6.25 micrograms/ml. The presence of basic amino acids in minimal medium less affected the antipseudomonal activity to a minimal extent, suggesting that BO-2727 has diverse penetration routes through the outer membrane other than OprD channel, which facilitates the diffusion of basic amino acids and carbapenems. The in vitro activity of BO-2727 reflected well in its therapeutic efficacy in experimental systemic infection in mice. These results suggest a possibility for the development of antipseudomonal carbapenems having activity against imipenem- and/or meropenem-resistant P. aeruginosa as well as a broad spectrum encompassing Gram-positive and -negative bacteria.

A novel human leukaemic cell line, CTS, has a t(6;11) chromosomal translocation and characteristics of pluripotent stem cells

A novel human leukaemic cell line, designated CTS, was established from the peripheral blood of a 13-year-old girl suffering from acute myeloblastic leukaemia (AML) in relapse. CTS cells expressed CD7, CD13, CD33, CD34 and HLA-DR antigens, and showed ultrastructural myeloperoxidase activity. In addition, CTS cells showed DNA rearrangements of the immunoglobulin heavy chain gene and the light kappa chain gene, and deletions of the T-cell receptor delta 1 gene. Cytogenetic analysis revealed a human female diploid karyotype with a t(6;11)(q27;q23) chromosomal translocation. Molecular studies demonstrated a DNA rearrangement of the MLL gene, the expression of a truncated 11.0 kb MLL mRNA and the detection of the MLL/AF-6 fusion transcript in CTS cells. To our knowledge, this cell line is the first report of a human leukaemic cell line with a t(6;11) chromosomal translocation. CTS cells showed no significant proliferative response to the cytokines, IL-2, IL-3, IL-6, IL-11, GM-CSF, G-CSF, EPO, SCF, but were induced to differentiate to the T-cell, B-cell, erythroid or megakaryocytic lineage in the presence of particular cytokines. This CTS cell line may provide a useful tool in the study of the oncogenesis of mixed lineage leukaemia with 11q23 abnormalities and for the analysis of growth and differentiation of pluripotent stem cells.

The effect of methylprednisolone on myocardial beta-adrenergic receptors and cardiovascular function in shock patients

The effect of methylprednisolone on the myocardial beta-adrenergic receptors after long term ( > 72 h) catecholamine infusion was studied. In 56 patients with pulmonary arterial catheter, 10 mg/kg of methylprednisolone was given as an intravenous bolus. Significant increases could be seen in cardiac output and blood pressure in patients who were simultaneously treated with vasopressors like dopamine and/or dobutamine. In patients who were on dopamine infusion higher than 10 micrograms/kg/min methylprednisolone there was an increase in the systemic vascular resistance. Patients who were not on vasopressors but received methylprednisolone, had no similar changes in hemodynamic parameters. In an in vitro analysis of tissue from the myocardium in 12/56 patients who succumbed and in four additional patients who expired after multiple trauma, a beta-adrenergic receptor assay was performed. It was found that the long term infusion of catecholamines decreased the receptor number and the methylprednisolone abolished or caused the decrease to be less pronounced. In this study we could not control the selection of the patients; a randomized study needs to be conducted in the future.

Expression patterns of Raf-1 suggest multiple roles in tooth development

Raf-1, the product of proto-oncogene c-raf-1, has key roles in the signal transduction pathways within the cell. The molecular mechanisms of tooth development in the mouse embryo are not known in detail. We examined the expression of Raf-1 during subsequent tooth development by immunohistochemical analysis. In mouse embryos at days 12.5 post-coitum (p.c.), Raf-1 was expressed in the dental invaginating epithelium. At p.c. 13.5 (bud stage), Raf-1 was also expressed in the epithelial cells of the enamel organ, but not in the mesenchyme of the dental papilla. We added anti-proliferating cell nuclear antigen (PCNA) antibody as a marker for proliferating cells at early stages of tooth development. At p.c. 12.5 and p.c. 13.5, the staining patterns were very similar to that for Raf-1. At p.c. 15.5 (cap stage), Raf-1 could not be detected. At p.c. 17.5 (bell stage), Raf-1 was expressed in both the odontoblastic and subodontoblastic cells of the dental papilla. However, Raf-1 was not found in the epithelial cells of the enamel organ. We also added anti-type I collagen antibody as a marker for odontoblasts differentiation. The staining pattern for type I collagen antibody as a marker for odontoblasts differentiation. The staining pattern for type I collagen in odontoblasts was almost the same as for Raf-1. The results suggest that Raf-1 may play some roles in both cell proliferation and differentiation at different stages of tooth germ development.

Enhanced phosphorylation of nuclear 21-kDa and 34-kDa proteins in hepatoma cell death induced by tumor-necrosis factor-alpha

The role of nuclear protein phosphorylation in intracellular signal transduction of tumor-necrosis factor-alpha (TNF-alpha) in the human hepatoma cell line PLC(PRF/5) was investigated. TNF-alpha, which displays cytolytic activity against PLC hepatoma cells, elevated the in vitro phosphorylation of two nuclear proteins (21 kDa and 34 kDa) 16 h after treatment. The cytotoxicity and enhanced nuclear protein phosphorylation by TNF-alpha treatment decreased in the presence of dexamethasone. Both the 21-kDa and 34-kDa proteins were extracted with 2.2 M NaCl from nuclear pellets and phosphorylated in kinase reaction mixtures containing a high concentration of salt. By phosphoamino acid analysis, the specificity of the nuclear kinase was found to be directed toward serine residues. The protein kinase inhibitors H7, staurosporine and herbimycin A, inhibited the phosphorylation of the 21-kDa and 34-kDa proteins in vitro, but calphostin C and heparin did not. The treatment of cells with 4 beta-phorbol 12-myristate 13-acetate or okadaic acid did not affect the in vitro phosphorylation of the two nuclear proteins. An anti-Fas antibody increased the phosphorylation of the 21-kDa and 34-kDa proteins in PLC cells. DNA fragmentation was observed in PLC cells treated with TNF-alpha and anti-Fas antibody after 24 h treatment. These data suggest an involvement of nuclear protein kinase in signal-transduction pathways of apoptotic cell damage triggered by TNF-alpha in PLC hepatoma cells.

Expression of multidrug resistant gene (mdr-1/P-glycoprotein) in a megakaryoblastic cell line, CMK, and its enhancement during megakaryocytic differentiation

Multidrug resistance is a severe clinical problem in the chemotherapy of malignant disease. Acute megakaryoblastic leukemia (AMKL) is a rare form of childhood leukemia, and is often resistant to many anti-cancer chemotherapeutic drugs. Here we report the expression of the mdr-1/P-glycoprotein in a cell line, CMK, established from a patient with AMKL. Expression of mdr-1 mRNA in CMK11-5 cells, a well differentiated subline, was higher than in CMK6 cells, a poorly differentiated subline. The level of P-glycoprotein was also higher in CMK11-5 cells. The cytokines interferon-gamma (IFN-gamma), GM-CSF and IL-3, which were shown to induce megakaryocytic differentiation of CMK cells, enhanced the expression of the mdr-1 mRNA and levels of P-glycoprotein. These results imply that differentiated megakaryocytic cells may have higher levels of the P-glycoprotein expression, suggesting a possible normal physiological function of P-glycoprotein in mature megakaryocytes.

Mechanism of enhanced antipseudomonal activity of BO-2727, a new injectable 1-beta-methyl carbapenem

The mechanism of the enhanced activity of BO-2727 against imipenem-resistant Pseudomonas aeruginosa was studied by using a set of four isogenic strains derived from beta-lactamase-deficient P. aeruginosa PAO4089 (blaJ blaP). Complementation of the blaJ and blaP mutations conferred greater resistance to biapenem, panipenem, and imipenem than to BO-2727 and meropenem, most notably in the outer membrane protein D2-deficient strain. The higher levels of resistance to biapenem, panipenem, and imipenem can be explained by the slow but significant hydrolysis by beta-lactamase, whereas the reduced levels of resistance to BO-2727 and meropenem would be attributable to their stability in the presence of high levels of beta-lactamase and the fact that they cause only low induction of beta-lactamase. It is also noted that the activity of BO-2727 against the beta-lactamase-deficient strain was less affected by the loss of the D2 porin than was that of meropenem, indicating that BO-2727 in comparison with meropenem can overcome an intrinsic resistance caused by the loss of D2. Moreover, comparative in vitro resistance studies have shown that BO-2727 and meropenem selected fewer resistant cells than other carbapenems. In conclusion, BO-2727 exhibited improved activity against imipenem-resistant P. aeruginosa, probably because of its ability to overcome loss of the D2 porin and beta-lactamase hydrolysis.

Corticosteroid effect on early beta-adrenergic down-regulation during circulatory shock: hemodynamic study and beta-adrenergic receptor assay

OBJECTIVES

The steroid effect on critically ill patients remains controversial. The aim of this study is to characterize the effect of methylprednisolone on the heart in a beta-adrenergically down-regulated condition.

DESIGN

A prospective hemodynamic study and retrospective receptor assay.

SETTING

Multidisciplinary ICU in a university hospital.

SUBJECTS

42 patients who required pulmonary arterial catheters and an additional 4 corpses who were available for study within 3 h of their deaths.

INTERVENTION

Intravenous methylprednisolone (10 mg/kg).

MEASUREMENTS AND RESULTS

We pursued a hemodynamic study following a glucocorticoid administration. In patients who had undergone a long term (> 72 h) catecholamine treatment, the cardiac index increased. In patients who had undergone a short term (1-72 h) catecholamine treatment and in patients with no record of catecholamine administration, the cardiac index showed no remarkable change. Among the corpses, who died soon after their arrival, and the patients, who later died in the ward and were available for further study, we measured beta-adrenergic receptor density in the left ventricular myocardium. It was found that receptor density was decreased after long term catecholamine treatment. Methylprednisolone, on the other hand increased the receptor density.

CONCLUSION

Methylprednisolone improved the cardiac index, intriguingly, in patients with long term catecholamine treatment in circulatory shock. Myocardial beta-adrenergic receptor also increased in number after the administration of methylprednisolone. However, the hemodynamic improvement caused by methylprednisolone was not observed in patients without beta-adrenergic down-regulation.

Changes in muscle and liver lactate concentrations after endotoxin infusion in rats

The interstitial lactate concentration in rat skeletal muscle and liver was measured using a microdialysis method during the early stage of endotoxemia and during lactic acid infusion. The lactate concentration in the muscle and liver interstitium never exceeded the blood lactate concentration throughout the 180 min period after endotoxin administration. The present findings also showed that the muscle and liver interstitial lactate concentration gradually increased in endotoxin-infused animals compared to that in lactic-acid infused animals, although the blood lactate concentration in lactic acid-infused animals was the same as that in endotoxin-infused animals. These findings suggest that the skeletal muscle and liver may consume lactate in an endotoxemic condition. However, the capacity of lactate consumption in the skeletal muscle might gradually decrease after endotoxin administration, although that in liver might be well preserved.

[Continuous intracarotid infusion of mannitol in severe head injury]

The clinical significance of continuous intracarotid infusion of a small dose of mannitol (ICI of mannitol) was discussed. Eighteen patients suffering from severe head injury with Glasgow coma scale (GCS) less than 6 were treated by ICI of mannitol for the improvement of raised intracranial pressure (ICP). In all of these 18 cases, conventional venous administration of mannitol could not be carried out, because of the unstable vital signs due to hypovolemic shock such as multiple trauma or disturbance of serum sodium and potassium levels. This method requires that a 20% mannitol solution be directly and continuously administered to the bilateral common carotid artery. The ICP 6 hours after the beginning of ICI of mannitol was significantly lower than the ICP just before the treatment. The total amount of excretion of the sodium and potassium through the urine every hour decreased significantly after this method was used. It was also noticed that this method was very suitable for stabilizing the vital signs in cases which had unstable vital signs such as hypovolemic shock. These findings suggested that ICI of mannitol has an advantage over the conventional venous administration of mannitol in cases which had to have correction of serum electrolyte or which had unstable vital signs.

Human papillomavirus type 13 and pygmy chimpanzee papillomavirus type 1: comparison of the genome organizations

Human papillomavirus type 13(HPV-13) is associated with oral focal epithelial hyperplasia (FEH) in humans. A recent epidemic of a FEH-like disease in a pygmy chimpanzee (Pan paniscus) colony allowed us to clone a novel papillomavirus genome. To assess the homology between HPV-13 and the pygmy chimpanzee papillomavirus type 1 (PCPV-1), the complete nucleotide sequences of both FEH-related viruses were determined. In both viruses, all eight major open reading frames were located on one strand and the genomic organization was similar to that of other mucosal papillomaviruses. The genomes of PCPV-1 and HPV-13 showed extensive overall sequence homology (85%). They could be classified, using phylogenetic analysis, together with HPV types 6, 11, 43, and 44 in a group associated with benign orogenital lesions. These data indicate that two phylogenetically related papillomaviruses can elicit similar pathology in different primate host species, reflecting viral genomic similarities.

The induction of IL-6 and gelatinase B by IL-1 in mouse cell lines transformed with bovine papillomavirus: decreased production in tumorigenic cells

Six cell lines, that were cloned from murine C127 cells infected by bovine papillomavirus type 1 (BPV1), were found to differ in the degree of transformation in vitro and of tumorigenicity in vivo. In these cell lines the degree of tumorigenicity was inversely correlated with IL-6 induction by IL-1 beta. Whereas the parental C127 cell line produced 15-30 U/ml of IL-6 spontaneously, none of the transformed cell lines produced significant levels of IL-6 constitutively. On induction by human IL-1 beta the parental C127 cell line produced up to 300 U/ml of IL-6, whereas the fully transformed ID14 cell line failed to produce any. The less transformed cell lines produced lower yields of IL-1 beta-induced IL-6, dependent on their degrees of transformation and tumorigenicity. Gelatinase B (96 kDa), a matrix metalloproteinase inducible by IL-1 beta, was dose-dependently regulated in the parental C127 cell line and in the weakly transformed cell line Tlc. These data suggest that transformation processes by BPV1 generally impair IL-1-regulated gene transcription. This impairment seems not to be located at the IL-1 beta receptor level, since in all the cell lines studied the numbers and affinities of the IL-1 beta binding sites were found to be comparable. This impairment seems not to be mediated by transformation-induced inactivation of the protein kinase C pathway since phorbol 12-myristate 13-acetate (PMA) induced IL-6 production equally well in all C127 cell-derived clones. It is suggested that BPV1 transformation can change the expression of host genes that might play a functional role in tumor immune surveillance and tumorigenicity in vivo.

[Amnesic effect of oral midazolam as premedication in children]

We evaluated the sedative and amnesic effects of oral midazolam as premedication in children. Sixteen children, aged 4-12 yr, undergoing elective minor surgery were divided into 2 groups. One group received midazolam 0.5 mg.kg-1 with atropine 0.03 mg.kg-1 orally. The other control group received only atropine 0.03 mg.kg-1. There was no significant difference in the sedative scale at induction between the 2 groups. Doll-recall was used to assess the amnesic effects. In the midazolam group, 75% of the children forgot dolls they had seen on entering the operating room. Midazolam produced significant anterograde amnesia but no retrograde amnesia. This result suggests that children who received midazolam as premedication forget unpleasant memories at induction and their postoperative emotional responses are least influenced by their memories. We conclude that oral midazolam 0.5 mg.kg-1 is an effective preanesthetic medication in children.

[The hemodynamics during hemodilution and its influence on the liver functions after hepatectomy for hepatocellular carcinoma with liver cirrhosis]

The hemodynamics during hemodilution occurred after hepatectomy for hepatocellular carcinoma with liver cirrhosis and its influences on the liver functions were studied. The hematocrit value gradually decreased about 10% until the 4th postoperative day owing to hemodilution after hepatectomy. While anemia progressed, cardiac index inversely increased. Under such a condition, oxygen consumption was maintained so that acidosis did not develop. Arterial blood ketone body ratio was also kept within a normal range except for a case whose hematocrit value decreased to 17.1%. Although the escaped hepatic enzymes such as GOT and GPT increased in the serum after hepatectomy, hemodilution was not responsible for their increase. While total bilirubin increased in the severe hemodiluted group, the increase was not due to hemodilution but caused by blood transfusion. The protein synthesis of the liver measured by rapid turnover protein levels in plasma was depressed after surgery, and this depression prolonged to the 14th postoperative day in the group whose hematocrit value decreased below 20%. These results suggest that it is better to keep hemodynamics without blood transfusion unless the hematocrit value decrease below 20%, and also better to maintain the hematocrit above 20% for liver regeneration after hepatectomy.

A papillomavirus related to HPV type 13 in oral focal epithelial hyperplasia in the pygmy chimpanzee

An epizootic of focal epithelial hyperplasia (FEH) or Morbus Heck in a pygmy chimpanzee (Pan paniscus) colony is described. Papovavirus-like particles were observed in the nuclei of epithelial cells. Analysis of the DNA of the lesions revealed an episomal papillomavirus-specific band with a molecular size of approximately 8,000 bp. In situ hybridization under high stringency conditions showed cross-hybridization between the chimpanzee papillomavirus DNA and human papillomavirus (HPV) type 13. The latter virus is uniquely associated with oral disease in man. This is the first demonstration of the association of a HPV 13-related pygmy chimpanzee papillomavirus (PCPV) and oral epithelial hyperplasia in a nonhuman primate.

Human papillomavirus type 6 and 11 E4 gene products in condyloma acuminata

The human papillomavirus type 6 (HPV-6) E4 gene was expressed in Escherichia coli as a fusion protein with E. coli beta-galactosidase (E4-beta-Gal), and rabbit antibody against the E4-beta-Gal was prepared. By Western blotting with this antibody, we detected E4 gene products in six out of 18 condyloma acuminata specimens. In four specimens (C-1, C-13, C-14 and C-19), the E4 protein was found as a 10K/11K doublet, but in other specimens (C-8 and C-23), only the 11K protein was detected. By Southern blot analysis, it was found that C-13 harboured HPV-6 DNA but that C-1 and C-8 harboured HPV-11 DNA, indicating that the E4 proteins of HPV-6 and -11 have cross-reactive antigenicity. After incubation at 37 degrees C of the C-23 tissue specimen, the 10K protein was clearly detected. These results suggest that the 10K protein may be derived from the 11K protein by a modification such as proteolytic cleavage before and/or after specimens were taken.

Interleukin 6, a possible autocrine growth and differentiation factor for the human megakaryocytic cell line, CMK

CMK is a human cell line derived from a megakaryoblastic leukaemia. It has characteristics of the megakaryocytic lineage, such as the presence of platelet peroxidase, membrane glycoproteins (GP)Ib and GPIIb/IIIa, alpha-granules, and demarcation membranes. The cell line proliferates autonomously in serum-containing medium. Here we report that the cell line expresses the gene for IL-6 and releases small quantities of the cytokine into the medium. Addition of exogenous IL-6 to cultures seeded into medium was found to promote growth of the cells. Conversely, addition of a neutralizing anti-IL-6 antibody inhibited cell growth. These data support the notion that autocrine IL-6 is one of the factors accounting for autonomous growth of the cell line.

Structure and expression of an integrated human papillomavirus type 16 genome amplified in a cervical carcinoma cell line

A cellular sequence containing the integrated human papillomavirus type 16 genome in a cervical carcinoma cell line QG-U was cloned and analysed. The transcriptionally active viral genome disrupted at the E2 and L2 open reading frames was amplified with its flanking sequences.

Growth and differentiation of a human megakaryoblastic cell line, CMK

Recently, a human megakaryoblastic cell line, CMK, was established from the peripheral blood of a megakaryoblastic leukemia patient with Down syndrome. Using this cell line, we studied the proliferation and differentiation of megakaryocytic cells in the presence of highly purified human hematopoietic factors and phorbol 12-myristate-13-acetate (PMA). In a methylcellulose culture system, interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) facilitated colony formation by CMK cells in a dose-dependent manner. The maximum stimulating doses of these factors were 10 and 200 U/mL, respectively. These concentrations were comparable to those that stimulate activity in normal hematopoietic cells. In contrast, granulocyte-colony stimulating factor (G-CSF), macrophage-colony stimulating factor (M-CSF), and erythropoietin (EPO) had no effects on the colony formation of CMK cells. In a liquid culture system, 20% of the CMK cells expressed glycoprotein IIb/IIIa (GPIIb/IIIa) antigen without hematopoietic factors, whereas 40% of the cells expressed GPIIb/IIIa with the addition of IL-3 and GM-CSF. EPO also slightly enhanced expression of GPIIb/IIIa. On the other hand, PMA inhibited growth of CMK cells and induced most of them to express the GPIIb/IIIa antigen. Furthermore, PMA induced CMK cells to produce growth activity toward new inocula of CMK cells. This growth factor (GF) contained colony-stimulating activity (CSA) in normal bone marrow (BM) cells. The activity was believed to be attributable mainly to GM-CSF, since 64% of this activity was neutralized by anti-GM-CSF antibodies and a transcript of GM-CSF was detected in mRNA from PMA-treated CMK cells by Northern blot analysis. These observations suggest that GM-CSF, as well as IL-3, should play an important role in megakaryocytopoiesis.

[Experimental studies on influences of intermittent hemihepatic vascular occlusion]

The influences of intermittent hemihepatic vascular occlusion in rats were investigated. The restoration of tissue energy level during 10 min of reperfusion after more than 40 min of occlusion was significantly lower than after occlusion within 30 min. over 40 min of occlusion which resulted in a significant increase of tissue free fatty acids during occlusion showed marked decrease of total adenine nucleotides (TAN) in the liver and marked increase of serum TAN in the hepatic vein after reperfusion. It was presumed that these findings were caused by wash-out of adenine-nucleotides from liver cell to the hepatic vein after reperfusion correlated with degradation of cell membrane. Thus, less than 30 min of occlusion was safe in hemihepatic vascular occlusion. Three times intermittent occlusion--repeats of 30 min of occlusion and 10 min of reperfusion--resulted in a same tissue energy level as once 40 min of occlusion. Furthermore, there was no difference in serum ornithine carbamoyltransferase, tissue oxygen consumption and ICG test during 48 hrs after reperfusion between three times intermittent occlusion and once 40 min of occlusion. These findings indicated that repetition of short time occlusion was useful in order to safely prolong total ischemic time in hemihepatic vascular occlusion.