A3 domain residue Glu1829 contributes to A2 subunit retention in factor VIIIa

BACKGROUND

Factor VIII (FVIII) is activated by thrombin to the labile FVIIIa, a heterotrimer of A1, A2 and A3C1C2 subunits, which serves as a cofactor for FIXa. A primary reason for the instability of FVIIIa is the tendency for the A2 subunit to dissociate from FVIIIa leading to an inactive cofactor and consequent loss of FXase activity.

OBJECTIVE

Based on our finding of low-specific activity and a fast decay rate for a FVIII point mutation of Glu1829 to Ala (E1829A), we examined whether residue Glu1829 in the A3 subunit is important for A2 subunit retention.

RESULTS

The rate of activity decay of E1829A was approximately fourteen fold faster than wild-type (wt) FVIIIa and this rate was reduced in the presence of added A2 subunit. Specific activity values for E1829A measured by one-stage and two-stage assays were approximately 14% and approximately 11%, respectively, compared with wt FVIII. Binding affinity for the A1 subunit to E1829A-A3C1C2 was comparable to wt A3C1C2 (K(d) = 20.1 +/- 3.4 nM for E1829A, 15.3 +/- 3.7 nM for wt), whereas A2 subunit affinity for the A1/A3C1C2 dimer forms was reduced by approximately 3.6-fold as a result of the mutation (K(d) = 526 +/- 107 nM for E1829A, 144 +/- 21 nM for wt).

CONCLUSION

As modeling data suggest that Glu1829 is located at the A2-A3 domain interface these results are consistent with Glu1829 contributing to the interactions involved with A2 subunit retention in FVIIIa.

The role of prostaglandins in liver ischemia-reperfusion injury

Ischemia reperfusion (IR) of the liver is a multifactorial process that, at least in part, is responsible for the morbidity associated with major liver surgery under occlusion of the portal triad with the Pringle maneuver, total vascular exclusion or after liver transplantation. Surgeons are confronted with IR injury (IRI) more often than they anticipate. Although the human body has its own defense system, understanding the pathophysiology of IRI is essential for the surgeon in preventing and/or treating the reperfusion injury in common clinical practice. Several endogenous mechanisms exist to overcome IRI and a large number of pharmacological agents have also been found to confer protection against ischemic injury in the liver. They either blocked the injurious pathways directly or they subjected the liver to preconditioning. Prostaglandins (PGs) are a group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase (COX) pathway. They are short-lived, hormone-like chemicals that regulate cellular activities on a moment-to-moment basis and are produced in most tissues of the body, although the liver has emerged as the major organ participating in the synthesis, degradation and elimination of arachidonate products of systemic origin. PGs are released through the prostaglandin transporter on the cell's plasma membrane. During the last decade intensive work on the cytoprotective effects of PGs on livers suffering from IRI have been well documented. Prostaglandins confer their protective effects on IR-injured livers mainly by inhibiting the generation of reactive oxygen species, preventing leukocyte migration, reducing the synthesis or production of membrane degradation products, improving hepatic insulin and lipid metabolism, and regulating the production of inflammatory cytokines and cell adhesion molecules. Production of PGs have been found essential also soon after partial hepatectomy for hepatocyte proliferation.

Significance of fluorodeoxyglucose PET imaging in the diagnosis of malignancies in patients with biliary stricture

AIM

This study was performed to evaluate the significance of positron emission tomography using fluorodeoxyglucose (FDG-PET) in diagnosing malignancy in patients with biliary stricture by comparing the sensitivity and specificity of FDG-PET with those of CT scans and cytological examination of the bile.

METHODS

Thirty patients who underwent FDG-PET for differential diagnosis of the disease causing biliary stricture were included in this study. The sites of the strictures were as follows: in the intrahepatic bile duct in five patients, in the peripheral extrahepatic bile duct in 17 patients, and in the distal extrahepatic bile duct in eight patients. The sensitivity and specificity (%) of FDG-PET in diagnosing malignancies were evaluated and compared with those of CT scans and cytological examination using obtained bile. Final diagnoses were based on surgical or biopsy findings. Data was collected and analysed in a retrospective fashion.

RESULTS

Malignant diseases were diagnosed in 21 patients, as follows: cholangiocarcinoma including Klatskin tumour in 10 patients, gallbladder cancer in eight, duodenal and ampulla cancer in two, and pancreatic cancer in one. In diagnosing malignancy in patients with biliary stricture, overall sensitivity and specificity were 85.7 (18/21) and 55.6 (5/9), respectively, for CT, 64.7 (11/17) and 100 (7/7), respectively, for cytological examination of the bile, and 90.5 (19/21) and 77.8 (7/9), respectively, for FDG-PET.

CONCLUSIONS

In diagnosing malignant diseases in patients with biliary stricture, FDG-PET was superior to CT examination in both sensitivity and specificity, and superior to cytological examination of the bile in sensitivity. However, in patients with inflammatory disease, such as primary sclerosing cholangitis and cholecystitis, false positive rates were found. Therefore, a multidisciplinary diagnostic approach using FDG-PET in conjunction with conventional modalities seems essential to a precise differential diagnosis.

Analysis of prognostic factors after surgery for stage III and IV gallbladder cancer

AIM

Survival and prognostic factors were analysed in patients who had undergone surgical resection with curative intention with the aim of identifying groups of patient with stage III and IV gallbladder cancer on the TNM classification who might benefit from surgery.

METHODS

Thirty-seven patients with advanced gallbladder cancer were studied, the cumulative survival rate for each group was calculated for each pTNM factor.

RESULTS

The 5-year survival rates in the stage III patients were 83.3%, while those for the stage IVA patients were 46.2%, and those for the stage IVB patients 16.7%.

CONCLUSIONS

In patients with invasion of adjacent organs, including the liver and gastrointestinal tract, and rated as pT3 or pT4, extended surgery excising the invaded tissue may be justified. In patients with pN2 lymph-node metastasis, even without adjacent organ invasion, radical surgery may not achieve a good outcome.

Emergent Treatment of Acute Embolic Superior Mesenteric Ischemia with Combination of Thrombolysis and Angioplasty: Report of Two Cases

We successfully revascularized the acutely occluded superior mesenteric artery (SMA), caused by a thromboembolus, with a combination of thrombolysis and percutaneous transluminal angioplasty (PTA) in 2 patients. Considerable percent luminal reduction (>90%) was still observed after thrombolysis in both patients. Subsequent adjunctive balloon angioplasty produced sufficient luminal diameter of the SMA (<20% luminal reduction). No serious acute procedural complication occurred. The time from onset to partial reperfusion by thrombolysis was approximately 4.5 and 5.5 hours. Approximately 1 week after the combination therapy, colonoscopy and a small bowel radiocontrast series showed localized mucosal ischemia with mild erosions and ulcerations in the terminal ileum and ascending colon in 1 patient. Subsequent bowel resection was required but the resection was short (<20 cm). The other patient's bowel condition was good and did not require any surgical treatment. The present cases suggest that combination therapy is useful for achieving rapid and sufficient revascularization of acute proximal thromboembolic SMA occlusion, and prevents the considerably broad bowel necrosis that requires surgical bowel resection, resulting in short bowel syndrome.

Interleukin-10 Suppresses Proliferation and Remodeling of Extracellular Matrix of Cultured Human Skin Fibroblasts

When we previously examined the participation of local expression of interleukin-10 (IL-10) and tumor necrosis factor-alpha (TNFalpha) in wound healing of an intestinal anastomosis under septic conditions in mice, we found that IL-10 and TNFalpha expressions were markedly enhanced around the anastomosis and that wound healing was impaired in this animal model. The purpose of the present study was to investigate the combined effect of IL-10 on proliferation and remodeling of the extracellular matrix (ECM) of cultured human skin fibroblasts. Human skin fibroblasts were cultured for 48 h with IL-10 and/or TNFalpha at various concentrations, then the proliferation rates were determined using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The concentration of transforming growth factor-beta1 (TGFbeta1) in cell culture supernatants was measured by enzyme-linked immunosorbent assay, and type I collagen protein and matrix metalloproteinase-I (MMP-I) were detected by indirect immunofluorescence in cultured cells incubated for 48 h with 10 ng/ml of IL-10 and/or 10 ng/ml of TNFalpha. IL-10 itself had no effect on fibroblast proliferation, but reduced TNFalpha-induced fibroblast proliferation. The concentration of TGFbeta1 in cell culture supernatants was significantly lower in the presence of TNFalpha and IL-10 than in the presence of TNFalpha alone. Immunolabeling of fibroblasts for type I collagen protein was decreased in cells incubated with IL-10 and/or TNFalpha compared to controls. MMP-I immunolabeling was increased in cells incubated with IL-10, IL-10 and TNFalpha compared to control and cells incubated with TNFalpha. It is suggested that IL-10 is an inhibitory factor for the remodeling of the ECM during wound healing.

Dynamics of experimental production of Thelohanellus hovorkai (Myxozoa: Myxosporea) in fish and oligochaete alternate hosts

The dynamics of development and production of Thelohanellus hovorkai (Myxozoa) were examined to investigate factors inducing haemorrhagic thelohanellosis in carp, Cyprinus carpio L. Fresh actinospores of T. hovorkai were harvested from the oligochaete alternate host, Branchiura sowerbyi, and used for infection experiments with myxosporean-free carp. Visualization of actinospores by fluorescent labelling revealed that sporoplasms penetrated the gill filaments of carp immersed in an actinospore suspension as early as 30 min post-exposure (PE). Plasmodia of T. hovorkai developed in the connective tissues of various organs and matured 3-5 weeks PE; dispersion of myxospores from degenerate plasmodia occurred 5-7 weeks PE. Challenges with a high dose of actinospores (4.5 x 10(6) spores per fish) resulted in the onset of disease, which was more easily achieved by the oral intubation of actinospores than by immersion in an actinospore suspension. Actinosporean-free B. sowerbyi were exposed to different densities of myxospores (10(4)-10(6) spores per oligochaete) and subsequently reared at different temperatures (15, 20, 25 degrees C). At 20 and 25 degrees C, actinospore releases were first detected 40-43 days PE, with multiple peaks of release (max. 7 x 10(5) actinospores day(-1)) during the next 60 days. We concluded that the developmental cycle of T. hovorkai was completed within 3-5 months at 20-25 degrees C, and that the ingestion of large numbers of actinospores orally, possibly by feeding on infected oligochaetes, resulted in a disease condition in carp.

Lactoferricin derived from milk protein lactoferrin

Lactoferricin (LFcin) was initially identified as an antimicrobial peptide derived by pepsin digestion of lactoferrin (LF), a multifunctional innate-defense protein in milk. Various synthetic analogs of LFcin have also been reported. LFcin inhibits a diverse range of microorganisms such as gram-negative bacteria, gram-positive bacteria, yeast, filamentous fungi, and parasitic protozoa, including some antibiotic-resistant pathogens. LFcin kills target organisms by membrane perturbation and acts synergistically with some antimicrobial agents. LFcin exhibits numerous biological activities in common with those of LF. Whereas LFcin suppresses the activation of innate immunity by microbial components such as lipopolysaccharide (LPS) and CpG DNA, the peptide itself activates immunity. Administration of LFcin analogs has been shown to protect the host via direct antimicrobial activity and immunostimulatory effects in several infection models of mice. Here we present a comprehensive review of investigations of LFcin and related peptides.

99mTc galactosyl human serum albumin liver dynamic SPET for pre-operative assessment of hepatectomy in relation to percutaneous transhepatic portal embolization

We have devised an original predictive residual index (PRI) using 99mTc diethylenetriaminepentaacetic acid galactosyl human serum albumin (99mTc-GSA) liver dynamic SPET for the pre-operative assessment of hepatectomy, including the prediction of residual liver function before hepatectomy. The aim of this study was to evaluate the usefulness of the PRI by using 99mTc-GSA liver dynamic SPET before and after percutaneous transhepatic portal embolization (PTPE) to induce compensatory hypertrophy of the remnant lobe, and to compare the results with the prognosis after hepatectomy. The subjects included eight patients with cholangiocellular carcinoma, five with gallbladder cancer, four with hepatocellular carcinoma and three with metastatic liver cancer. 99mTc-GSA liver dynamic SPET was performed immediately before and 2 weeks after PTPE. Dynamic SPET with 35 continuous rotations was performed to obtain the k-value according to the accumulation curve in each voxel (0.54 cm x 0.54 cm x 1.08 cm) of the liver immediately after a bolus injection of 185 MBq 99mTc-GSA. Each rotation consisted of 180 degrees turn in 64 steps in a 64 x 64 matrix. The acquisition time of each rotation was 35 s. We devised an original PRI by combining the k-value with functional liver volume which were measured by liver dynamic SPET. Hepatectomy was performed following the second SPET. The correlation between the PRI and post-operative patient prognosis was investigated retrospectively. The functional liver volume of the remnant lobe and the PRI significantly increased after PTPE compared with respective values before PTPE (P<0.005 and P<0.0001, respectively). Regarding the relationship between the PRI and the clinical course following surgery, post-operative complications were observed in only two patients. The PRI values of these two patients were 0.323 and 0.394. When the PRI was above 0.400, no patient had symptoms of hepatic failure. The results of this study suggest that, when the PRI value is above 0.400, there is a low probability of hepatic failure after hepatectomy. We conclude that the PRI devised in this study is useful in the pre-operative assessment of hepatectomy after PTPE.

Bovine lactoferrin and lactoferricin derived from milk: production and applications

Bovine lactoferrin is produced on an industrial scale from cheese whey or skim milk. The safety of purified lactoferrin has been confirmed from the results of a reverse mutation test using bacteria, a 13-week oral repeated-dose toxicity study in rats, and clinical studies. In order to apply active lactoferrin to various products, a process for its pasteurization was developed. Subsequently, lactoferrin has been used in a wide variety of products since it was first added to infant formula in 1986. A pepsin hydrolysate of lactoferrin is also used in infant formula. This hydrolysate contains a potent antimicrobial peptide named lactoferricin that is derived from the lactoferrin molecule by pepsin digestion. Semilarge-scale purification of lactoferricin can be performed by hydrophobic interaction chromatography. Lactoferricin also exhibits several biological actions and appears to be the functional domain of lactoferrin. Recent studies have demonstrated that oral administration of lactoferrin or lactoferricin exerts a host-protective effect in various animals and in humans. The results of these studies strongly suggest that the effects of oral lactoferrin are mediated by modulation of the immune system. Further elucidation of the clinical efficacy and mechanism of action of lactoferrin will increase the value of lactoferrin-containing products.

Changes in arterial and portal perfusion in embolized and nonembolized hepatic lobes after portal vein embolization evaluated by helical computed tomography

We evaluated the changes in hepatic arterial and portal perfusion in nonembolized as well as in embolized lobes after portal venous branch embolization (PVE) with dynamic helical computed tomography (CT). Six patients with hepatic malignancies, who underwent PVE prior to a subsequent hepatectomy, were the subjects of this study. We performed CT examinations before PVE and 2 weeks after PVE to make a volumetric analysis. At the same time, we performed single-location dynamic sequences after the injection of a 50-ml bolus of contrast medium, and we then created time-density curves from circular regions of interest drawn over the aorta, parenchyma of the right and left lobe of the liver, and spleen. We calculated the arterial perfusion index (ml/min per ml of tissue) and the portal perfusion index by dividing the maximum rate of enhancement of the liver before and after the splenic peak by the peak aortic enhancement. We then calculated the arterial and portal flows (ml/min) from the perfusion index and values of CT volumetry. In the right lobe, where the portal flow was occluded, the arterial perfusion index and flow increased significantly after PVE. In contrast, the arterial perfusion index and flow both decreased in the left lobe after PVE in a reverse response to the increase in the portal perfusion index and flow. The total arterial flow of the liver thus seemed to slightly increase; however, the change was not significant. By performing PVE an increased arterial perfusion was induced in the embolized lobe, with a concomitant decrease in arterial perfusion in the nonembolized lobe.

Is preoperative portal vein embolization effective in improving prognosis after major hepatic resection in patients with advanced-stage hepatocellular carcinoma?

BACKGROUND

The impact of the use of preoperative portal vein embolization (PVE) on long-term survival after surgery was evaluated by retrospective analysis of prognostic factors in patients with advanced-stage hepatocellular carcinoma (HCC) who had undergone hepatic resection with or without PVE.

METHODS

The portal embolization group (Group P) consisted of 26 patients who had undergone major hepatectomy (more extensive than right hepatectomy) with PVE, and the nonembolized group (Group N) consisted of 43 patients who had undergone major hepatectomy without PVE. All patients were diagnosed with advanced HCC graded as Stage III or IV according to the International Union Against Cancer TNM classification system. Patient survival rates, recurrence rates, and recurrence sites after surgery in the two groups were evaluated and compared.

RESULTS

The 1-year, 3-year, and 5-year cumulative disease specific survival rates in patients with TNM Stage III HCC, respectively, were 96.0%, 64.4%, and 52.7% in Group N and 92.9%, 57.1%, and 45.7% in Group P, whereas the corresponding values in patients with Stage IV HCC were 53.5%, 40.1%, and 26.8% in Group N and 63.5%, 50.8%, and 19.1% in Group P. There were no statistically significant differences in survival rates between Group P and Group N. Multivariate analysis showed that PVE was not a significant prognostic factor. The 1-year, 3-year, and 5-year cumulative recurrence rates for patients with both stages of disease combined were 44.1%, 80.2%, and 86.8% in Group N, respectively, and 39.9%, 72.2%, and 72.2% in Group P, respectively, with no statistically significant differences between the two groups. To date, 35 patients in Group N and 16 patients in Group P have had tumor recurrences in the liver remnant; of these, 27 patients in Group N and 12 patients in Group P had multiple recurrence foci in the liver remnant. No significant difference was seen between the two groups; however, 10 of 16 patients in Group P (62.5%) had remote organ metastasis in addition to recurrence in the liver remnant compared with only 6 of 35 patients in Group N (17.1%): This difference was significant statistically (P = 0.012).

CONCLUSIONS

PVE during major hepatic resection neither improves nor worsens long-term prognosis but allows resection in a patient group that, otherwise, is considered as unresectable. Remote metastasis involving the lung, bone, or stomach was seen more frequently postoperatively in Group P compared with Group N, raising a possibly important issue regarding the use of this approach for the treatment of patients with hepatic malignancies, especially HCC.

Is preoperative portal vein embolization effective in improving prognosis after major hepatic resection in patients with advanced-stage hepatocellular carcinoma?

BACKGROUND

The impact of the use of preoperative portal vein embolization (PVE) on long-term survival after surgery was evaluated by retrospective analysis of prognostic factors in patients with advanced-stage hepatocellular carcinoma (HCC) who had undergone hepatic resection with or without PVE.

METHODS

The portal embolization group (Group P) consisted of 26 patients who had undergone major hepatectomy (more extensive than right hepatectomy) with PVE, and the nonembolized group (Group N) consisted of 43 patients who had undergone major hepatectomy without PVE. All patients were diagnosed with advanced HCC graded as Stage III or IV according to the International Union Against Cancer TNM classification system. Patient survival rates, recurrence rates, and recurrence sites after surgery in the two groups were evaluated and compared.

RESULTS

The 1-year, 3-year, and 5-year cumulative disease specific survival rates in patients with TNM Stage III HCC, respectively, were 96.0%, 64.4%, and 52.7% in Group N and 92.9%, 57.1%, and 45.7% in Group P, whereas the corresponding values in patients with Stage IV HCC were 53.5%, 40.1%, and 26.8% in Group N and 63.5%, 50.8%, and 19.1% in Group P. There were no statistically significant differences in survival rates between Group P and Group N. Multivariate analysis showed that PVE was not a significant prognostic factor. The 1-year, 3-year, and 5-year cumulative recurrence rates for patients with both stages of disease combined were 44.1%, 80.2%, and 86.8% in Group N, respectively, and 39.9%, 72.2%, and 72.2% in Group P, respectively, with no statistically significant differences between the two groups. To date, 35 patients in Group N and 16 patients in Group P have had tumor recurrences in the liver remnant; of these, 27 patients in Group N and 12 patients in Group P had multiple recurrence foci in the liver remnant. No significant difference was seen between the two groups; however, 10 of 16 patients in Group P (62.5%) had remote organ metastasis in addition to recurrence in the liver remnant compared with only 6 of 35 patients in Group N (17.1%): This difference was significant statistically (P = 0.012).

CONCLUSIONS

PVE during major hepatic resection neither improves nor worsens long-term prognosis but allows resection in a patient group that, otherwise, is considered as unresectable. Remote metastasis involving the lung, bone, or stomach was seen more frequently postoperatively in Group P compared with Group N, raising a possibly important issue regarding the use of this approach for the treatment of patients with hepatic malignancies, especially HCC.

Nutritional therapy of chronic hepatitis by whey protein (non-heated)

In an open study the clinical efficacy of milk serum (whey) protein (Immunocal; cysteine content: 7.6-fold higher than that of casein) isolated from fresh milk and purified without heating was evaluated in 25 patients with chronic hepatitis B or C. Immunocal (12 g as protein) food (mousse) was given twice a day, in the morning and evening, for 12 weeks (test period). Casein (12 g as protein) food (mousse) was similarly given for two weeks prior to the start of the supplement with Immunocal food (induction period) and for four weeks after the end of the supplement with Immunocal food (follow-up period). Serum alanine aminotransferase (ALT) activity was reduced, and plasma glutathione (GSH) levels increased in six and five of eight patients with chronic hepatitis B, respectively, 12 weeks after the start of the supplement with Immunocal food. Serum lipid peroxide levels significantly decreased, and interleukin (IL)-2 levels and natural killer (NK) activity significantly increased. However, there were no significant Immunocal-related changes in 17 patients with chronic hepatitis C. These findings suggest that the long-term supplement with Immunocal alone may be effective for improving liver dysfunctions in patients with chronic hepatitis B.

Is preoperative portal vein embolization effective in improving prognosis after major hepatic resection in patients with advanced-stage hepatocellular carcinoma?

BACKGROUND

The impact of the use of preoperative portal vein embolization (PVE) on long-term survival after surgery was evaluated by retrospective analysis of prognostic factors in patients with advanced-stage hepatocellular carcinoma (HCC) who had undergone hepatic resection with or without PVE.

METHODS

The portal embolization group (Group P) consisted of 26 patients who had undergone major hepatectomy (more extensive than right hepatectomy) with PVE, and the nonembolized group (Group N) consisted of 43 patients who had undergone major hepatectomy without PVE. All patients were diagnosed with advanced HCC graded as Stage III or IV according to the International Union Against Cancer TNM classification system. Patient survival rates, recurrence rates, and recurrence sites after surgery in the two groups were evaluated and compared.

RESULTS

The 1-year, 3-year, and 5-year cumulative disease specific survival rates in patients with TNM Stage III HCC, respectively, were 96.0%, 64.4%, and 52.7% in Group N and 92.9%, 57.1%, and 45.7% in Group P, whereas the corresponding values in patients with Stage IV HCC were 53.5%, 40.1%, and 26.8% in Group N and 63.5%, 50.8%, and 19.1% in Group P. There were no statistically significant differences in survival rates between Group P and Group N. Multivariate analysis showed that PVE was not a significant prognostic factor. The 1-year, 3-year, and 5-year cumulative recurrence rates for patients with both stages of disease combined were 44.1%, 80.2%, and 86.8% in Group N, respectively, and 39.9%, 72.2%, and 72.2% in Group P, respectively, with no statistically significant differences between the two groups. To date, 35 patients in Group N and 16 patients in Group P have had tumor recurrences in the liver remnant; of these, 27 patients in Group N and 12 patients in Group P had multiple recurrence foci in the liver remnant. No significant difference was seen between the two groups; however, 10 of 16 patients in Group P (62.5%) had remote organ metastasis in addition to recurrence in the liver remnant compared with only 6 of 35 patients in Group N (17.1%): This difference was significant statistically (P = 0.012).

CONCLUSIONS

PVE during major hepatic resection neither improves nor worsens long-term prognosis but allows resection in a patient group that, otherwise, is considered as unresectable. Remote metastasis involving the lung, bone, or stomach was seen more frequently postoperatively in Group P compared with Group N, raising a possibly important issue regarding the use of this approach for the treatment of patients with hepatic malignancies, especially HCC.

Helicobacter pylori alters n-6 fatty acid metabolism and prostaglandin E2 synthesis in rat gastric mucosal cells

BACKGROUND AND AIMS

Little is known about whether Helicobacter pylori infection alters fatty acid metabolism in gastric mucosal cells. By using cultured rat gastric mucosal cells (RGM-1), we investigated the effect of H. pylori broth culture filtrates on this point. Furthermore, our study aimed to find out whether n-6 long chain polyunsaturated fatty acids from linoleic acid are formed in RGM-1 cells.

METHODS

Rat gastric mucosal cells were incubated with 10, 20 and 40 microg/mL of linoleic acid or medium alone. Phosphatidylcholine content extracted from whole RGM-1 cells was quantitated by using a densitometer, and its fatty acid composition was analyzed by using gas chromatography. Prostaglandin E2 concentration in the culture medium was measured by using radioimmunoassay. The expression of cyclooxygenase (COX)-1 and COX-2 was examined by using reverse transcription-polymerase chain reaction. In addition, after incubation with [1-14C] linoleic acid, radioactivities of both linoleic acid and arachidonic acid components of the PC fraction were counted. The effects of H. pylori broth culture filtrates on PC content, its fatty acid composition and prostaglandin (PG)E2 synthesis were also assessed.

RESULTS

Linoleic acid addition caused an increase in the composition of arachidonic acid, as well as linoleic acid, and also in PGE2 concentration. Cyclo-oxygenase-2 expression was induced in RGM-1 cells by the addition of linoleic acid. In addition, [1-14C] linoleic acid added to the culture medium was converted to [1-14C] arachidonic acid in RGM-1 cells. Helicobacter pylori broth culture filtrates decreased linoleic acid composition and increased arachidonic acid composition. Moreover, after incubation with H. pylori broth culture filtrates, PGE2 concentrations were higher than that of the controls.

CONCLUSIONS

These findings suggest the presence of fatty acid elongase and Delta5- and Delta6-desaturases synthesize arachidonic acid from linoleic acid in RGM-1 cells. Thus, H. pylori infection may enhance PGE2 synthesis and accelerate n-6 fatty acid metabolism in gastric mucosal cells, which could make the gastric mucosal barrier more fragile.

Structural analysis of the sugar chains of human urinary thrombomodulin

The sugar chains of human urinary thrombomodulin were studied. N- and O-linked sugar chains were simultaneously liberated by hydrazinolysis followed by N-acetylation and were tagged with 2-aminopyridine. Then the structures of the N- and O-linked pyridylamino (PA-) sugar chains were analyzed by two-dimensional sugar mapping combined with exoglycosidase digestion. The major N-linked sugar chains of human urinary thrombomodulin were found to be monosialo- and disialofucosylbiantennary chains, while the major O-linked sugar chain was +/-Siaalpha2-3Galbeta1-3(+/-Siaalpha2-6)GalNAc. Thrombomodulin also contained the reported structure SO4-3GlcAbeta1-3Galbeta1-3(+/-Siaalpha2-6)Galbeta1-4Xyl [H. Wakabayashi, S. Natsuka, T. Mega, N. Otsuki, M. Isaji, M. Naotsuka, S. Koyama, T. Kanamori, K. Sakai, and S. Hase (1999) J. Biol. Chem. 274, 5436-5442]. In addition to these sugar chains, a single Glc was linked to Ser 287.

Increased concentrations of 14-3-3 epsilon, gamma and zeta isoforms in cerebrospinal fluid of AIDS patients with neuronal destruction

BACKGROUND

14-3-3 proteins are major evolutionarily conserved cytosolic proteins that regulate signal transduction, apoptosis and neurotransmitter synthesis. Five homologous 14-3-3 isoforms, beta, gamma, zeta, epsilon and eta, are reported in mammalian neurones. To elucidate the diagnostic value of 14-3-3 in cerebrospinal fluid (CSF), a highly specific antibody against each isoform and studies on the isoform patterns in patients with neuronal destruction are needed.

METHODS

In this study, we raised isoform-specific antibodies against 14-3-3 proteins and established a semiquantitative method of identification of each isoform by Western immunoblotting.

RESULTS

We found that three isoforms, 14-3-3 epsilon, gamma and zeta, appeared in the CSF of HIV patients with AIDS dementia complex or cytomegalovirus encephalitis, but not in AIDS patients without neurological symptoms or the non-HIV patients examined. The isoform patterns in AIDS patients were different from those reported in Creutzfeldt-Jakob disease and herpes simplex encephalitis, suggesting that the isoform patterns may facilitate the differential diagnosis. A high frequency of 14-3-3 in CSF was observed in seriously ill AIDS patients, particularly those with CD4 levels of less than 20 mm(3).

CONCLUSION

These findings suggested that 14-3-3 proteins were released from destroyed neural cells and are useful real-time markers of the rate and amount of neural cell destruction in these patients.

Biological activity of a fruit vegetable, "Anastasia green", a species of sweet pepper

Russian green sweet pepper (Anastasia Green) was successively extracted with hexane, acetone, methanol and 70% methanol and the extracts were further separated into a total of twenty fractions by silica gel or ODS column chromatographies. The biological activities of these extracts and fractions were compared. The extracts and fractions showed higher cytotoxic activity against two human oral tumor cell lines than against normal human gingival fibroblasts, suggesting their tumor-specific action. Several fractions [H3, H4, A4] reversed the multidrug resistant gene (MDR1) against L5178 mouse T-cell lymphoma more effectively than (+/-) verapamil (positive control). All extracts and fractions showed no anti-human immunodeficiency virus (HIV) nor anti-Helicobacter pylori activity. These data suggest the medicinal importance of an Anastasia Green extract.

Retrohepatic vena cava replacement of hepatic malignancies without using total hepatic vascular exclusion or extracorporeal bypass

Total hepatic vascular exclusion and venovenous bypass are frequently used surgical procedures when concomitant resection of the inferior vena cava is required during surgery of liver cancer involving the retrohepatic inferior vena cava close to the hepatic veins. However, the duration of total hepatic vascular exclusion is limited due to the risk of hepatic ischemia. Three patients presented with severely compressed inferior vena cava and/or hepatic veins due to liver cancer. The surgical procedure involved initial taping of the inferior vena cava just below the hepatic veins by extrahepatic division and taping of the hepatic veins. After taping the inferior vena cava, hepatectomy with caval resection was performed by simply clamping the retrohepatic inferior vena cava, without the need for total hepatic vascular exclusion or venovenous bypass. In all patients the retrohepatic inferior vena cava were safely replaced with a prosthetic graft under stable hemodynamics. Duration of the inferior vena cava clamping was 31, 66, 75 minutes, respectively. No graft-related complications occurred, but 2 of the 3 patients showed temporal renal dysfunction associated with renal congestion postoperatively. The surgical procedure described herein is effective for the treatment of retrohepatic inferior vena cava in some patients. However, when the case is complicated by chronic nephropathy or simultaneous nephrectomy is required, venovenous bypass should be performed.

Metal ion-independent association of factor VIII subunits and the roles of calcium and copper ions for cofactor activity and inter-subunit affinity

Factor VIII circulates as a divalent metal ion-dependent heterodimer comprised of a light chain (LC) and a heavy chain (HC). Reassociation of factor VIII subunits was assessed using fluorescence energy transfer where LC and HC were labeled with acrylodan (Ac; fluorescence donor) and fluorescein-5-maleimide (Fl; fluorescence acceptor), respectively. The reduction of donor fluorescence due to the acceptor was used as an indicator of binding. Subunits associated with high affinity (K(d) = 53.8 nM) in the absence of metal ion and presence of EDTA. However, this product showed no cofactor activity, as measured by a factor Xa generation assay. In the presence of 25 mM Ca(2+), no increase in the intersubunit affinity was observed (K(d) = 48.7 nM) but specific activity of the cofactor was approximately 30% that of native factor VIII. At saturating levels of Fl-HC relative to Ac-LC, donor fluorescence decreased to 79.3 and 73.5% of its original value in the absence and presence of Ca(2+), respectively. Thrombin cleaved the heterodimers that were associated in the absence or presence of Ca(2+) with similar efficiency, indicating that the lack of activity was not the result of a defect in activation. Cu(2+) (0.5 microM) increased the intersubunit affinity by approximately 100 fold (K(d) = 0.52 nM) and the specific activity to approximately 60% of native factor VIII. The former effect was independent of Ca(2+), whereas the latter effect required Ca(2+). These results indicate that the intersubunit association in factor VIII is primarily metal-ion independent while divalent metal ions serve specific roles. Ca(2+) appears essential to promote the active conformation of factor VIII while Cu(2+) primarily enhances the intersubunit affinity.