Changes in hepatitis C virus quasispecies and density populations in patients before and after interferon therapy

Some chronic hepatitis C patients show sustained response to interferon (IFN) therapy despite viremia. This condition seems to be related to the density populations of hepatitis C virus (HCV) [Kanto et al. (1995): J Med Virol 46:230-237]. To investigate further the relationship between alanine aminotransferase (ALT) levels after IFN therapy and the HCV density populations, we undertook differential flotation centrifugation of HCV and single strand conformation polymorphism targeted the hypervariable region (HVR) of E2 glycoprotein, which seems to be related to the density populations. Sera were obtained serially from 12 patients who had undergone IFN therapy (six sustained responders with viremia, six nonresponders). During the follow-up after interferon therapy, the HVR heterogeneities changed in 9 of the 12 patients. The remaining three patients whose heterogeneities did not changed persistently showed normal ALT. The changes in HVR heterogeneities were less pronounced in the sustained responders with viremia than in nonresponders; however, their density populations were prominently high in both responders. In two cases, changes in HVR heterogeneities and increase in low-density virion were observed before the hepatitis flare-up. These data indicate that HVR quasispecies show more relation to ALT levels after IFN therapy than HCV density populations and that the changes in the HVR sequences and HCV density populations may be associated with ALT elevation in some patients.

Gene therapy against an experimental glioma using adeno-associated virus vectors

The efficacy of gene therapy for glioma was examined using adeno-associated virus (AAV)-based vectors to deliver genes to experimental tumors in mice. Stereotactic injection of 2 x 10(5) U-251SP human glioma cells into the brains of nude mice produced tumors of 19.06 +/- 1.79 mm2 17 days after injection. Employing a high titer preparation of AAV vector containing the gene for beta-galactosidase (AAV-lacZ), dose-dependent transduction of U-251SP cells was seen in vitro. When 1.6 x 10(10) AAV-lacZ particles were directly injected into tumors in vivo, 30-40% of the cells along the needle track expressed beta-galactosidase. Transduction of U-251SP cells in vitro with an AAV vector containing a bicistronic gene encoding both herpes simplex thymidine kinase and human interleukin-2 (AAV-tk-IRES-IL2) rendered them sensitive to the cytocidal effects of ganciclovir (GCV) and IL-2 was produced in a dose-dependent manner. Cocultures of AAV-tk-IRES-IL2 transduced cells and nontransduced cells proved highly sensitive to GCV indicating the contribution of the bystander effect. Stereotactic delivery of 6 x 10(10) AAV-tk-IRES-IL2 particles into day 7 tumors in nude mice followed by administration of GCV for 6 days, resulted in a 35-fold reduction in the mean volume of tumors compared with controls. Normal brains did not suffer from any toxic effect of the administration of AAV-tk-IRES-IL2 and GCV. These results indicate that high titer AAV vector treatment may be safe and effective for in vivo gene therapy of human brain tumors.

[Teaching experience of laparoscopic cholecystectomy: a report from Beijing]

I arrived at Beijing on August 13, 1995, having been appointed to a tutor for laparoscopic cholecystectomy (LSC) in the Sino-Japanese Friendship Hospital therein by the Japan International Cooperation Agency. This hospital was inaugurated in 1984 and accommodates up to 1,300 in patients. In the history of surgery, nevertheless, the laparoscopic method is revolutionary in that many doctors share the operative field, make judgments, and perform procedures, all of which are open to observers. These features, however, attest the Chinese philosophy of the surgeons and the Asian idea to respect the elderly in the traditional Chinese clinic. We therefore attempted to create a team for endoscopic surgery by junior surgeons and sought cooperation to anesthesiologists and nurses in the operating room. On August 21, 1995. I attended the first operation as an endoscopist teaching the mini-laparotomy method at the placement of a trocar. Even in the introductory period of LSC, we had to treat patients immediately after gallstone attack. Thus I detailed the precautions at dissecting the triangle of Calot. We found the EndoflexTM retractor of great use in those patients with severe adhesion. While paying respect for their dignity, we told the necessity of teamwork where one has to give way sometimes for the establishment of this new type of operative style. A total of eight patients underwent LSC by the time I left China on September 10, 1995. We wish that this seed of laparoscopic surgery would proliferate in this young hospital located, however, in the capital of a country with eternal history.

Splenic B-cell activation in lipopolysaccharide-non-responsive C3H/HeJ mice by lipopolysaccharide of Porphyromonas gingivalis

Porphyromonas gingivalis 381 lipopolysaccharide (LPS) definitely exhibited mitogenic activity in purified B-cells, separated from spleens of LPS-responsive C3H/HeN mice and LPS-non-responsive C3H/HeJ mice by using a magnetic cell sorting system. The mitogenic activity induced by P. gingivalis LPS was incompletely inhibited by polymyxin B. P. gingivalis LPS also induced a higher production of interleukin-6 (IL-6) in splenic B-cells of C3H/HeN mice as compared with Escherichia coli LPS. Furthermore, P. gingivalis LPS, but not E. coli LPS, induced definite IL-6 production in C3H/HeJ mice. P. gingivalis LPS increased tyrosine, serine/threonine phosphorylation of proteins with various major induced bands in splenic B-cells of both C3H/HeN and C3H/HeJ mice. Additionally, radioiodinated P. gingivalis LPS, similarly to E. coli LPS, bound to a 73-kDa protein on C3H/HeJ as well as C3H/HeN B-cells. Thus P. gingivalis LPS may activate B-cells of C3H/HeJ as well as C3H/HeN mice via the LPS-specific binding protein on the cells.

ASA physical status and age are not factors predicting morbidity, mortality, and survival after pancreatoduodenectomy

To evaluate the effects of age and physical status on postoperative complications, American Society of Anesthesiologists-Physical Status score (ASA score) and age were analyzed in patients undergoing pancreatoduodenectomy (PD). Medical records and follow-up results of 69 patients who had undergone PD from 1980 to 1993 at one institution were examined. Clinical variables affecting morbidity and mortality rates were analyzed, and compared between two-aged groups (> or = 70 years (n = 18) and < 70 (n = 51)). Univariate Cox regression analysis of 69 patients showed that ASA score and age were not significant factors affecting postoperative morbidity, mortality, and survival. The clinical variables including ASA score, gender, operative time, blood loss, stage, and location of carcinoma were similarly distributed between the two-aged groups. The mortality rate in patients less than 70 years of age was 5.9 per cent (3/51), whereas there was no mortality in patients more than 70 years of age. The morbidity, mortality, and cumulative survival rates were statistically similar in the two age groups. The results suggest that ASA-physical status and age are not limiting factors for PD and do not predict survival. The procedure is safe and worthwhile even in patients more than 70 years of age with the ASA score up to III.

Inferior vena caval thrombus associated with double neoplasms of the retroperitoneum and kidney: report of a case

We report herein the case of a patient we recently encountered who was found to have a giant retroperitoneal tumor coincident with tumor thrombus in the inferior vena cava (IVC). On the assumption that the origin was retroperitoneal, the two lesions were resected using an intracaval filter. However, histopathological examination of the specimens revealed neurilemoma for the retroperitoneal tumor and adenocarcinoma for the tumor thrombus. A right renal tumor was subsequently detected, which led to right nephrectomy being performed en bloc with part of the IVC using a venoarterial bypass. Microscopy revealed carcinoma of the Bellini duct, or collecting duct, which is an extremely rare tumor. Retrospectively, a lesion with soft tissue density was noted in the renal vein. Surgical management focused on the prevention of pulmonary embolism. We describe this case because of its extreme rarity and its significance from the viewpoint of diagnosis and therapeutic strategies.

Cytolysis of malignant glioma cells by lymphokine-activated killer cells combined with anti-CD3/antiglioma bifunctional antibody and tumor necrosis factor-alpha

With the aim of developing an effective immunotherapy for malignant glioma, glioma cells were incubated with tumor necrosis factor-alpha (TNF-alpha) to increase their susceptibility to lysis by lymphokine-activated killer (LAK) cells. Treatment with exogenous TNF-alpha induced the expression of intercellular adhesion molecule-1 (ICAM-1) on the surface of glioma cells. In addition, the cytolytic activity of LAK cells toward exogenous TNF-alpha treated glioma cells was significantly greater than LAK cell activity toward untreated glioma cells. This increase in cytolytic activity was blocked by anti-ICAM-1 monoclonal antibodies (MAb). Furthermore, co-treatment with a bifunctional antibody (BFA) composed of anti-CD3 (UCHT1) and antiglioma (G-22) antibodies synergistically increased the cytolytic activity of LAK cells towards TNF-alpha-treated glioma cells. These results indicate that a combination of exogenous TNF-alpha and anti-CD3/antiglioma BFA may provide an effective modified adoptive immunotherapy for patients with malignant glioma.

Effect of testosterone on carbonic anhydrase and MG(2+)-dependent HCO3-stimulated ATPase activities in rat kidney: comparison with estradiol effect

Effects of testosterone administration (TP; 1-3 mg/kg body weight, S.C., once daily for 7 days) on the cytosol carbonic anhydrase (CA) and tubular brush border Mg(2+)-dependent HCO3(-)-stimulated ATPase (Mg(2+)-HCO3(-)-ATPase) activities of normal and castrated male and female rat kidney were compared with estradiol (E2) effects. TP decreased kidney CA activity in a dose-dependent manner in all four animal conditions, and negative correlations were observed between cytosol CA activity and serum testosterone concentration. However, brush border Mg(2+)-HCO3(-)-ATPase activity was not affected by testosterone. Orchiectomy increased only CA activity and its value recovered to normal levels by 3 mg/kg TP replacement, whereas Mg(2+)-HCO3(-)-ATPase activity did not change. In the previous study, on the other hand, E2 administration activated both kidney enzymes in normal male rats and only Mg(2+)-HCO3(-)-ATPase in normal female rats. Testosterone and E2 conversely affected kidney CA activity in male rats. These facts suggest that the cytosol CA may control kidney functions on H+ and HCO3- metabolism under the balance of both sex hormones in the living body.

Nucleotide sequences of the hepatitis C virus core region in patients without anti-core antibody

Second-generation assays for detection of hepatitis C virus (HCV) infection that include reactivity of antibodies to core, NS3, NS4 are used because of their high sensitivity. Among these antibodies, anti-core antibody seems to be the most sensitive. However, there are some patients without anti-core antibodies, although HCV RNA is detectable by reverse transcription-polymerase chain reaction and branched DNA assay. The mechanism for the absence of anti-core antibody on its own is unclear. We therefore determined the nucleotide and deduced amino acid sequences of the core region obtained from two anti-core antibody-negative patients with HCV RNA (genotype 1b) and compared them with those of four anti-core antibody-positive patients and a previously reported sequence. Amino acids spanning 1-47, which seemed to exist in major B cell epitopes, were found to be completely conserved among these patients. Furthermore, the predictive binding motif to HLA DR4 (a.a 81-90) was completely conserved in both of the anti-core antibody-negative patients. There were various mutations in the residual amino acids spanning 49-108, but specific mutations could not be found in anti-core antibody-negative patients. These data indicate that the absence of anti-core antibody in two patients is not due to the presence of some formerly unknown viral variants, but due to a possible defect in the host's immune system.

Single oral dose of cisapride accelerates gastric antral emptying in healthy humans: an ultrasonographic study

An ultrasonographic study of ten healthy volunteers was carried out to evaluate the effect of cisapride on gastric antral emptying. More than 1 week after the measurement of the baseline emptying rate, cisapride was given at a single oral dose of 5 mg 30 minutes before intake of a balanced liquid test meal (5 ml/kg body weight). To determine the time to half emptying (T1/2), an exponential curve was extrapolated for the elimination phase of the gastroantral sagittal cross-sectional area plotted against time. The T1/2 was reduced by 18.5% after cisapride, from 62.6 +/- 4.3 to 51.0 +/- 4.4 min (P = 0.0284). We conclude that a single oral dose of 5 mg of cisapride significantly accelerates the gastric antral emptying rate in healthy humans.

Monoclonal antibody against the fusion junction of a deletion-mutant epidermal growth factor receptor

A mouse monoclonal antibody (IgG2b), 3C10, was produced against the truncated epidermal growth factor receptor (EGFR), encoded by the (type III) in-frame deletion mutation of 801 nucleotides of EGFR affecting the external domain, known to be expressed in some human glioblastoma. As this mutation newly generates a glycine residue at the fusion point, a 14 amino acid peptide around the fusion junction including this glycine was chemically synthesised and used for immunisation of (B6 x DBA/2) F1 mice. Flow cytometric analysis showed 3C10 antibody staining of a mouse NIH/3T3 transfectant (ERM5) with the type III EGFR deletion-mutant gene, but not one with wild-type EGFR. The antibody immunoprecipitated the truncated EGFR protein with a molecular mass of approximately 140 kDa from ERM5 cells. Immunostaining of glioblastomas revealed binding in the case with the type III EGFR mutation, the five other specimens without the mutation being negative despite overexpression of EGFR in some cases.

Tumor necrosis factor-alpha gene transfer augments anti-Fas antibody-mediated apoptosis in human glioma cells

To effectively induce apoptosis in human glioma cells, we tried to transfer the tumor necrosis factor (TNF)-alpha gene into glioma cells to produce TNF-alpha locally in these cells. The stable transfectants of three glioma cells (U251-SP, U251-MG, and T98G) were resistant to exogenous TNF-alpha, but their cell surface expression of the Fas antigen was dramatically enhanced by about 10 to 100-fold as compared with untransfected glioma cells exposed to exogenous TNF-alpha. The Fas antigen is a transmembrane cytokine receptor protein of the nerve growth factor/TNF receptor superfamily. Although the untransfected glioma cells tested were resistant to anti-Fas antibody-mediated apoptosis, the TNF-alpha gene-transfected glioma cells exhibited high susceptibility to anti-Fas antibody-mediated apoptosis. Thus, TNF-alpha gene transfer combined with anti-Fas antibodies may be useful for the treatment of malignant glioma.

Computed tomographic findings of Bellini duct carcinoma of the kidney

OBJECTIVE

To analyze CT findings of Bellini duct carcinoma, a rare variant of renal cell carcinoma.

MATERIALS AND METHODS

The CT findings of five cases of Bellini duct carcinoma were reviewed and the findings were recorded.

RESULTS

In all cases the affected kidneys maintained the normal outer contours. In four cases the renal masses protruded into the central sinuses. Contrast enhancement was minimal in four cases.

CONCLUSION

Bellini duct carcinoma should be suspected in cases with these CT findings.

Suppression of CD44 expression decreases migration and invasion of human glioma cells

We have reported high expression of CD44H in human glioma cells. To investigate the role of CD44H in the invasion of human glioma, we established a CD44-anti-sense-gene-expression glioma cell line named U-251A1. The expression of CD44H in the G-418-selected U-251A1 cells was reduced to 20% of that in the parental U-251SP cells, as determined by flow-cytometry analysis. We first examined the migratory responses of U-251A1 cells in vitro by time-lapse video-microscopic sparse cell-migration assay on hyaluronic acid or on chondroitin 6 sulfate. U-251A1 cells did not show significant differences in motility on any substrate, while U-251SP and other CD44H-positive cells showed dose-dependent increase of migration specifically on hyaluronic acid. To examine the physiologic function of CD44H in gliomas in vivo, U-251A1 and its control cells, U-251S1, which retain CD44-sense-expression vector, were injected stereotactically into the brains of nude mice. U-251A1 cells were localised in the region of the injection site, with relatively well demarcated borders between tumour and brain tissue, while the control cells demonstrated a cell-infiltration pattern. Our data suggest that CD44H may be required for infiltration of glioma cells through its interaction with hyaluronic acid, a major component of the brain extracellular matrix.

Streptococcal glycoprotein-induced tumour cell growth inhibition involves the modulation of a pertussis toxin-sensitive G protein

We studied the mechanism of anti-tumour action of sulphydryl glycoprotein (SAGP) purified from an extract of Streptococcus pyogenes in vitro. SAGP rapidly inhibited the incorporation of nucleic acid precursors into murine fibrosarcoma (Meth A) cells before it inhibited the cell growth. SAGP-induced cell growth inhibition was diminished by incubating the cells with pertussis toxin (IAP), whereas the SAGP activity was augmented by incubating the cells with cholera toxin (CTX). Meth A cells exposed to SAGP underwent an increase in labelling of the alpha-subunit of an inhibitory guanine nucleotide-binding (Gi) protein in a subsequent IAP-catalysed [32P]ADP ribosylation of the cell membrane fraction. Gi alpha labelling was not increased either in the membrane from the Meth A cells exposed to heat-inactivated SAGP or in the membrane from L929 cells exposed to SAGP, in which growth was also unaffected. By contrast, SAGP caused no alteration in labelling the alpha-subunit of stimulatory guanine nucleotide-binding (Gs) protein in a subsequent CTX-catalysed ADP ribosylation of membrane fractions of Meth A and L929 cells. The amount of intracellular cAMP was decreased slightly in Meth A cells incubated with SAGP. Although the precise roles of Gs protein and adenylate cyclase in the cell growth inhibition induced by SAGP are not clear, these findings suggested that the modulation of Gi protein is involved in such SAGP-induced cellular events as the inhibition of nucleic acid synthesis and cell growth inhibition.

A case of extragonadal germ cell tumor with elevated postchemotherapy HCG successfully treated by resection of a solitary metastasis and chronic oral etoposide

We report a 39 year-old man with disseminated extragonadal germ cell tumor (GCT), whose serum level of human chorionic gonadotropin (HCG) increased again after platinum-based combination chemotherapy, high-dose chemotherapy with autologous bone marrow rescue and radical adjunctive surgery. The increase in the HCG level was progressive in spite of multiple chemotherapy, and after a while, a coin lesion in the right lung was identified by chest roentgenography. The pulmonary lesion was refractory to additional chemotherapy. After a systemic survey to confirm that the lesion was solitary, video-assisted thoracoscopic wedge resection of the right lower lobe was performed. Because the resected tumor included viable tumor cells and the serum HCG level remained slightly high one month after the operation, oral low-dose etoposide was begun. In a short time, the level of the serum tumor marker decreased and remained normal during the subsequent 7 months of therapy and thereafter. The patient remains in complete remission 13 months after completion of the final therapy and 3 years after the initial diagnosis. Even if the level of a serum tumor marker is high, salvage resection can be a promising therapeutic option for operable tumors that are refractory to chemotherapy. The usefulness of chronic oral etoposide for patients with GCT should be examined by further clinical trials.

New approach for the treatment of medulloblastoma by transfection with glial fibrillary acidic protein gene

Glial fibrillary acidic protein (GFAP) is one of the intermediate filaments found in mature normal astrocytes and differentiated glioma cells. It seems to be able to stabilize the cytoskeleton of the astrocyte and may play a role in maintaining astrocyte cell shape, in association with other cytoskeletal components such as microfilaments and microtubles. However, its tissue-specificity remains unclear. To clarify the effect of GFAP expression in brain tumour cells, transfer of the GFAP gene into the human medulloblastoma cell line, DAOY-1 (which does not express GFAP) was carried out using liposomes. Upon transfection, we observed the alterations in the characteristics of GFAP transfected cells. Cell growth, morphology and sensitivity to anticancer drugs were compared between GFAP gene transfected DAOY-1 and control DAOY-1 cells. Growth inhibition and increase of sensitivity to anticancer drugs were observed with GFAP expression in GFAP gene-transfected DAOY-1 cells. However, no morphological changes were noted.

Repeated exposure to cationic immunoliposomes activates effective gene transfer to human glioma cells

The use of whole immunoglobulin G (IgG) and F(ab')2 of the G-22 monoclonal antibody associated with cationic liposomes (immunoliposomes) and the effect of repeated exposure were investigated for the transfection of the LacZ gene to various glioma cell lines. Immunoliposomes associated with either whole IgG or F(ab')2 monoclonal antibody caused an about 2-fold increase in beta-galactosidase activity compared with liposomes associated with no antibody in glioma cell lines expressing the CD44 antigen. beta-Galactosidase activity was further increased by about 2-fold by repeated exposure compared with single exposure. A glioma cell line not expressing the CD44 antigen showed no such increase in beta-galactosidase activity. These results indicate that repeated exposure of cationic immunoliposomes achieves a higher transfection efficiency and is a potentially effective method of gene therapy for patients with malignant glioma.

Atrophic changes of gastric mucosa are caused by Helicobacter pylori infection rather than aging: studies in asymptomatic Japanese adults

BACKGROUND

The current study was designed to evaluate the effect of aging and Helicobacter pylori infection on the gastric mucosa in asymptomatic Japanese adults.

MATERIALS AND METHODS

Eighty-five asymptomatic healthy adults were recruited from a health-screening center in Sapporo. All subjects underwent endoscopy and gastric biopsy, and serum was obtained for IgG antibodies to H. pylori, serum gastrin, and pepsinogen levels.

RESULTS

The prevalence of atrophic change of the gastric mucosa assessed by pathological findings increased with age (49% in the 30- to 39-year-old group compared to 89% in those 60 years and older, p < .001). The frequency of intestinal metaplasia also increased with age (38% in the 30- to 39-year-old group compared to 82% in those 60 years and older, p < .001). In contrast, the frequency of atrophic gastritis and intestinal metaplasia was extremely low in the H. pylori seronegative group regardless of age. Mean serum gastrin level in H. pylori-positive adults was significantly greater than in those who were H. pylori-negative (114.3 +/- 11.2 compared to 65.8 +/- 6.5 pg/ml, p < .03). The serum pepsinogen I-II ratio was significantly lower in those with H. pylori infection than in those without (3.1 compared to 6.6, p < .0001).

CONCLUSIONS

These results suggest that the chronological changes in the gastric mucosa in Japanese individuals are either entirely related to H. pylori infection or the process is greatly accelerated by H. pylori infection.

Endobronchial lipoma: a report of three cases

Although lipomas are common benign neoplasms of soft tissue, endobronchial lipoma is rare. We have treated three patients with endobronchial lipoma over the five years. In two of them lesions were located in segmental or subsegmental bronchi and produced no symptoms. There are very few such cases reported in the English medical literature. In the first case, pneumonectomy was performed because of destruction of the lung due to recurrent pneumonia. The second case had no symptoms and the tumor was located at the bifurcation of right B4a and B4b. A right middle lobectomy was performed, because the distal end of the tumor could not be visualized by fiberoptic bronchoscopy. In the third case, which was a case of lung cancer, an endobronchial lipoma was found during fiberoptic bronchoscopy, and was completely removed endoscopically. Due to their benign nature, endobronchial lipomas should be initially treated with endoscopic surgery or endoscopic laser vaporization. Nevertheless, if the tumor is large and dumbbell-shaped on tomography or CT, endoscopic procedures are not appropriate. Furthermore, if destructive pulmonary change due to the tumor is severe, the remaining peripheral lung will not recover after endoscopic procedures, even if they are removed successfully. When the biopsy specimen is too small to allow evaluation of the whole tumor, surgical resection should also be considered for definitive diagnosis.

Practical classification of the branching types of the biliary tree: an analysis of 1,094 consecutive direct cholangiograms

BACKGROUND

The structure of the biliary tree has been classified according to the relationship between the hepatic segmental ducts and the cystic duct. Because laparoscopic cholecystectomy demands precise knowledge of biliary anatomy, we propose a simplified classification of the bile ducts.

STUDY DESIGN

A consecutive series of 1,094 direct cholangiograms were analyzed and the letters A, P, R, L, and C were designated for the right anterior, right posterior, right, left, and cystic ducts, respectively. The arborizing patterns of the hepatic bile ducts were classified into either the bifurcation of the right and left ducts (RL); triple confluence of the right anterior, right posterior, and left ducts (APL); separate branching of A and P in the duodenohepatic direction; or discrete branching of P and A (P-AL) where branches A and P were in reverse of A-PL. Cystic duct anomaly was added in parentheses.

RESULTS

The classified ducts had the following distribution: RL, 67.7 percent; APL, 17.7 percent; A-PL, 8.0 percent; and P-AL, 6.0 percent. Cystic duct anomalies occurred in 1.6 percent of all the cases and were in frequent association with the P-AL pattern. The most common type was P-AL (P-C) seen in 0.5 percent of cases, where the cystic duct merged into the lower branching P.

CONCLUSIONS

Our practical classification of the biliary tree anatomy may contribute to the practice of biliary surgery.

Blood gas analysis of placental and uterine blood during cesarean delivery

OBJECTIVE

To measure blood gases in uterine venous blood and maternal and fetal blood from the placenta, and to characterize gas exchange in the intervillous space.

METHODS

Blood gas measurements were performed immediately after collecting placental and uterine blood from the subchorial and marginal lakes, from the chorionic vein and artery in the placenta in utero, and from the uterine vein during 12 cesarean deliveries.

RESULTS

The mean oxygen pressure (PO2) values of the chorionic vein and subchorial lake were 28.7 +/- 6.0 and 29.9 +/- 7.5 mmHg, respectively, with a difference of 1.2 mmHg. The individual data for PO2 of the chorionic vein exceeded those of the subchorial lake in five subjects and were almost equal in two of the 12 subjects. The mean values of carbon dioxide pressure (PCO2) and bicarbonate were greater in the chorionic vein than in the subchorial lake, but the mean pH values were the same in the two groups. The mean values of blood gas analysis were not different between subchorial and marginal lakes with similar blood composition. The mean PO2 of the uterine vein in ten subjects was 45.9 mmHg, significantly higher than that of the subchorial lake.

CONCLUSIONS

The human placenta may be defined as a multivillous model with a high degree of oxygen transfer. Arteriovenous anastomoses are suspected in the pregnant uterus beyond 37 weeks' gestation. Subchorial and marginal lakes contain similar admixed blood, which circulates and performs gas exchange.

[Antitumor effect of intra-arterial tumor necrosis factor-alpha in rats with transplanted intracerebral glioma and its evaluation by MRI]

Recombinant human TNF-alpha was administrated intra-arterially to rats with transplanted intracerebral glioma. 1 x 10(6) of T9 rat glioma cells were transplanted into Fisher 344 rat brain stereotaxically and 1000 units of TNF-alpha was administrated at a rate of 100 microl/min. via an internal carotid artery 1 or 3 weeks after the transplantation. The effects of TNF-alpha were evaluated by MRI and histopathological examinations. Neurological symptoms, i.e. hemiparesis, appeared after 9.0 +/- 0.63 days and all rats died of tumor overloading 14.5 +/- 0.84 days after the transplantation. Single injection of TNF-alpha on 7th day after the transplantation induced regression of the tumor size in one of six rats. The tumors were detected 3 days after transplantation by MRI and they were revealed as low/iso intensity mass in T1WI, iso/high intensity in T2WI, and were enhanced by Gd-DTPA heterogeneously. On 7/14 days after the transplantation, the tumor grew approximately 7/10 mm in diameter. The single 1000 units of TNF-alpha were administrated via an internal carotid artery. 3 days after the administration of TNF-alpha, regression of the tumor size was seen in one of six rats and decrease of peritumoral edema was seen in three. These effects of TNF-alpha were, however, transient and they were not demonstrated on day 7. Single injection of TNF-alpha was not effective for large tumors more than 10 mm in diameter seen 14 days after the transplantation. These data suggest that intra-arterial TNF-alpha should be administrated at an early stage of the tumor growth and several injections are needed to cause regression in the size of the gliomas.