Refractory gastrointestinal bleeding treated with thyroid hormone replacement

Although bleeding diathesis has been associated with hypothyroidism, refractory gastrointestinal bleeding has not been previously described in association with hypothyroidism. We report a patient who presented with refractory gastrointestinal bleeding over an 8-week period. Extensive work-up demonstrated small intestinal vascular malformations as the source of bleeding. Despite endoscopic therapy and hormonal therapy, bleeding continued and required transfusion of 54 units of packed red blood cells. Surgical therapy was offered to the patient but was declined. Ultimately, correction of the patient's underlying hypothyroidism resulted in cessation of gastrointestinal bleeding, and no further blood transfusion was necessary. To date, the patient has remained euthyroid without further gastrointestinal bleeding for 30 months.

Involvement of mitogen-activated protein kinase in cyclic adenosine 3',5'-monophosphate-induced hormone gene expression in rat pituitary GH(3) cells

We examined whether mitogen-activated protein (MAP) kinase was activated by stimulation of the cAMP pathway and whether MAP kinase activation was involved in synthesis of PRL and GH in GH(3) cells. Treatment of the cells with a cAMP analog, 8-(4-chlorophenylthio)cAMP (CPT-cAMP), activated MAP kinase and increased PRL at both the protein and messenger RNA levels. The protein and messenger RNA of GH were decreased by the treatment. We constructed the luciferase reporter genes after the promoters of PRL and GH and found the activation of both promoters by the CPT-cAMP treatment. We confirmed that overexpression of the catalytic subunit of cAMP-dependent protein kinase had essentially the same effects on MAP kinase activation and synthesis of PRL and GH as the CPT-cAMP treatment. Furthermore, treatment of the cells with pituitary adenylate cyclase-activating polypeptide 27 activated MAP kinase. The activation of PRL promoter by CPT-cAMP and pituitary adenylate cyclase-activating polypeptide 27 was abolished by pretreatment with PD098059 and H89. Although the increase in PRL and GH secretion by CPT-cAMP was inhibited by H89, PD098059 had no effect on secretion. These results suggest that cAMP-induced MAP kinase activation is essential for PRL gene expression, but not for secretion of PRL and GH.

Activation of calcium/calmodulin-dependent protein kinase IV in long term potentiation in the rat hippocampal CA1 region

The importance of well characterized calcium/calmodulin-dependent protein kinase (CaMK) II in hippocampal long term potentiation (LTP) is widely well established; however, several CaMKs other than CaMKII are not yet clearly characterized and understood. Here we report the activation of CaMKIV, which is phosphorylated by CaMK kinase and localized predominantly in neuronal nuclei, and its functional role as a cyclic AMP-responsive element-binding protein (CREB) kinase in high frequency stimulation (HFS)-induced LTP in the rat hippocampal CA1 region. CaMKIV was transiently activated in neuronal nuclei after HFS, and the activation returned to the basal level within 30 min. Phosphorylation of CREB, which is a CaMKIV substrate, and expression of c-Fos protein, which is regulated by CREB, increased during LTP. This increase was inhibited mainly by CaMK inhibitors and also by an inhibitor for mitogen-activated protein kinase cascade, although to a lesser extent. Our results suggest that CaMKIV functions as a CREB kinase and controls CREB-regulated gene expression during HFS-induced LTP in the rat hippocampal CA1 region.

Increased intracranial pressure in a porcine model of fulminant hepatic failure using amatoxin and endotoxin

BACKGROUND/AIMS

The purpose of this study was to develop a clinically relevant porcine model of fulminant hepatic failure (FHF) by means of administration of amatoxin and endotoxin.

METHODS

Pigs were intraportally administered only saline in group 1 (n = 3), 1 microg/kg of lipopolysaccharide (LPS) in group 2 (n = 4), 0.1 mg/kg of alpha-amanitin in group 3 (n = 5), and amanitin plus LPS in group 4 (n = 9).

RESULTS

All the pigs in groups 1 and 2 survived with minimal changes in liver function tests. In contrast to the 60% mortality in group 3, all the pigs in group 4 died within 96 h, with a significant increase in aspartate transaminase at 24 h (9,757 +/- 2,167 IU/I). In addition, they demonstrated severe metabolic disorders, such as serum lactate accumulation, hypoglycemia, coagulopathy, plasma amino acid imbalance, and hyperammonemia. The intracranial pressure significantly increased to 17.8 +/- 2.5 mmHg immediately before death. Reversal of FHF in these pigs following orthotopic liver transplantation confirmed that the toxicity is liver-specific and that the graft liver is unaffected.

CONCLUSIONS

This porcine model of FHF induced by a combination of amanitin and LPS will be of much use in the development of new therapies for human FHF.

Quantitative evaluation of selenium contained in tea by high performance liquid chromatography

For determination of selenium (Se) in biological materials, an improved method based on high performance liquid chromatographic determination of the fluorophore formed by reaction of selenite with 2,3-diaminonapththalene was developed. The concentration detection limits were 0.5 ng/g in dried materials and 0.03 ng/mL in fluid materials. In quadruplicate assays of 11 biological reference materials using the proposed method, measured Se concentrations were not significantly different from their certified values. Thus, the proposed method is reliable and suitable for the determination of trace levels of Se in foods. Using the proposed method, Se concentrations in various kinds of tea were determined to assess the contribution of tea to daily Se intake in the Japanese population. Se concentration in the leaves of general black, green and oolong tea obtained in local retail stores was 33 +/- 19 ng/g (n=440). The leaves of a particular Chinese green tea sold under the name "high Se tea" were found to contain 455 +/- 184 ng/g (n= 14) of Se. While the percentage of Se extractable by infusion was less than 5% for the general teas, that in the high Se tea was more than 20%. These results indicated that intake of tea does not contribute to daily Se intake in the Japanese population. However, since infusions from high Se tea contained over 5 ng/mL of Se, consumption of over 1 L/d of tea derived from such high Se teas may increase the daily Se intake by close to 10%.

Amyloid beta protein activates PKC-delta and induces translocation of myristoylated alanine-rich C kinase substrate (MARCKS) in microglia

The increased accumulation of activated microglia containing amyloid beta protein (Abeta) around senile plaques is a common pathological feature in subjects with Alzheimer's disease (AD). Much less is known, however, of intracellular signal transduction pathways for microglial activation in response to Abeta. We investigated intracellular signaling in response to Abeta stimulation in primary cultured rat microglia. We found that the kinase activity of PKC-delta but not that of PKC-alpha or -epsilon is increased by stimulation of microglia with Abeta, with a striking tyrosine phosphorylation of PKC-delta. In microglia stimulated with Abeta, tyrosine phosphorylation of PKC-delta was evident at the membrane fraction without an overt translocation of PKC-delta. PKC-delta co-immunoprecipitated with MARCKS from microglia stimulated with Abeta. Abeta induced translocation of MARCKS from the membrane fraction to the cytosolic fraction. Immunocytochemical analysis revealed that phosphorylated MARCKS accumulated in the cytoplasm, particularly at the perinuclear region in microglia treated with Abeta. Taken together with our previous observations that Abeta-induced phosphorylation of MARCKS and chemotaxis of microglia are inhibited by either tyrosine kinase or PKC inhibitors, our results provide evidence that Abeta induces phosphorylation and translocation of MARCKS through the tyrosine kinase-PKC-delta signaling pathway in microglia.

Comparison of 99Tcm-MIBI with 201Tl chloride SPET in patients with malignant brain tumours

The purpose of this study was to evaluate the usefulness of 99Tcm-MIBI accumulation for the differentiation of histological diagnosis of malignant brain tumours in comparison with the findings obtained using 201Tl chloride. A total of 25 patients with malignant brain tumours were investigated. The histological categories of tumours included glioblastoma multiforme (n = 5), anaplastic astrocytoma (n = 4), malignant lymphoma (n = 5), and metastatic tumour (n = 11). Simultaneous dual single photon emission tomography (SPET) images with 99Tcm-MIBI and 201Tl were acquired 15 min (early) and 2 h (delayed) after injection, and the early ratio, delayed ratio and retention index were measured. The new indices 201Tl/99Tcm-MIBI ratios and 201Tl/99Tcm-MIBI retention index were also calculated. With respect to the histological type, a higher retention index using 99Tcm-MIBI was noted in glioblastoma multiforme compared with metastatic tumour. Higher values of both ratios using 201Tl were noted in glioblastoma multiforme compared to metastatic tumour. The value of the delayed ratio obtained using 201Tl was higher in glioblastoma multiforme than in anaplastic astrocytoma, and the value was also higher in malignant lymphoma than in metastatic tumour. The 201Tl/99Tcm-MIBI early ratio of glioblastoma multiforme was significantly higher than that of metastatic brain tumour. The 201Tl/99Tcm-MIBI retention index of malignant lymphoma was significantly higher than that of glioblastoma multiforme. In the histological type of tumour, 99Tcm-MIBI is not superior to 201Tl, but the combined indices using 201Tl/99Tcm-MIBI may add new information about differential diagnosis.

Removal of mixtures of acetaldehyde and propionaldehyde from waste gas in packed column with immobilized activated sludge gel beads

The removal of mixed acetaldehyde and propionaldehyde as a model of the binary contaminants in waste gas was studied in the packed column containing the immobilized activated sludge gel beads together with the hollow plastic balls developed for the removal of a single aldehyde in the previous work. The rate of each aldehyde biodegradation by the gel beads in the aldehydes mixture was expressed by the Michaelis-Menten type rate equation with an inhibitory term due to the other coexistent aldehyde. The kinetic parameters involved were found to be the same as those determined previously for biodegradation of a single aldehyde. A model for prediction of removal of each aldehyde in the packed column was developed assuming that each aldehyde dissolved in the aqueous phase within the gel bead was biodegraded according to the above rate equation with no mass transfer effect. The packed column was stable and efficient for removal of the binary aldehydes mixture with a very low pressure drop for gas flow due to a reduced gel beads bed compaction by the hollow plastic balls. Removal of each aldehyde decreased with increasing the inlet aldehyde concentrations since each biodegradation rate itself approached asymptotically the maximum one with increase in each aldehyde concentration. The observed removals for each aldehyde in the aldehydes mixture agreed well with those calculated from the design equations developed. The contact efficiency of gel beads with the waste gas stream was estimated to be the same value of 0.24 as in the previous work, supporting that the efficiency was specific to the geometrical and physical properties of the packed column used.

Inhibition of cell growth and spreading by stomach cancer-associated protein-tyrosine phosphatase-1 (SAP-1) through dephosphorylation of p130cas

SAP-1 (stomach cancer-associated protein-tyrosine phosphatase-1) is a transmembrane-type protein-tyrosine phosphatase that is abundant in the brain and certain cancer cell lines. With the use of a "substrate-trapping" approach, p130(cas), a major focal adhesion-associated phosphotyrosyl protein, has now been identified as a likely physiological substrate of SAP-1. Expression of recombinant SAP-1 induced the dephosphorylation of p130(cas) as well as that of two other components of the integrin-signaling pathway (focal adhesion kinase and p62(dok)) in intact cells. In contrast, expression of a substrate-trapping mutant of SAP-1 induced the hyperphosphorylation of these proteins, indicating a dominant negative effect of this mutant. Overexpression of SAP-1 induced disruption of the actin-based cytoskeleton as well as inhibited various cellular responses promoted by integrin-mediated cell adhesion, including cell spreading on fibronectin, growth factor-induced activation of extracellular signal-regulated kinase 2, and colony formation. Finally, the enzymatic activity of SAP-1, measured with an immunocomplex phosphatase assay, was substantially increased by cell-cell adhesion. These results suggest that SAP-1, by mediating the dephosphorylation of focal adhesion-associated substrates, negatively regulates integrin-promoted signaling processes and, thus, may contribute to contact inhibition of cell growth and motility.

Evaluation of histopathological differentiation in lung adenocarcinoma patients using 201Tl-chloride and 99Tcm-MIBI SPET

The purpose of this prospective study was to evaluate the relationship between thallium-201 chloride (201Tl) and technetium-99m hexakis 2-methoxyisobutylisonitrile (99Tcm-MIBI) accumulation and histopathological differentiation in primary lung adenocarcinoma. A total of 43 patients with primary lung adenocarcinoma were investigated. The patients were divided into well differentiated (n = 17), moderately differentiated (n = 14) and poorly differentiated (n = 12) carcinoma groups. Simultaneous dual single photon emission tomography (SPET) images with 201Tl and 99Tcm-MIBI were acquired 15 min (early) and 2 h (delayed) after injection. Using a region of interest technique, the tumour-to-normal lung ratio was calculated for both early (early ratio) and delayed (delayed ratio) images. The retention index was calculated using the formula delayed ratio/early ratio. Uptake of the radionuclides was compared with the classification of tumour differentiation grading. The mean (+/- SD) values of the early ratio, delayed ratio and retention index using 201Tl were 2.19+/-0.72, 2.28+/-0.71 and 1.06+/-0.16, respectively, in the well differentiated group, 2.38+/-0.83, 2.48+/-0.84 and 1.08+/-0.23, respectively, in the moderately differentiated group, and 2.87+/-0.75, 3.60+/-1.51 and 1.22+/-0.21, respectively, in the poorly differentiated group. Both the ratios and the retention index using 201Tl were significantly lower in the well differentiated group than in the poorly differentiated group. The delayed ratio using 201Tl in the moderately differentiated group was also significantly lower than that in the poorly differentiated group. There were no significant differences in either ratio or the retention index among the three groups using 99Tcm-MIBI. 201Tl SPET is superior to 99Tcm-MIBI SPET for the grading of histopathological differentiation of primary lung adenocarcinoma.

Role of platelet-activating factor in hepatectomy with Pringle's maneuver

BACKGROUND

Interruption of hepatic inflow is commonly used to reduce blood loss during extensive liver resection, but may cause liver dysfunction. The present study investigated the effects of platelet-activating factor (PAF) antagonist E5880 on total liver warm ischemia and 70% hepatectomy.

METHODS

Rabbits were used in this study and were divided into four groups: group 1, those treated with only 70% hepatectomy; group 2, those treated with only 20 min Pringle's maneuver; group 3, those treated with both Pringle's maneuver and 70% hepatectomy without pretreatment; and group 4, those pretreated with PAF antagonist E5880 (0.3 mg/kg) followed by Pringle's maneuver and 70% hepatectomy. The remnant liver function was then evaluated after reperfusion.

RESULTS

Seven-day survival rates in both groups 1 and 2 were 100%. E5880 treatment significantly increased 7-day survival rate (group 4: 38% vs group 3: 0%, P < 0.05) after a combination of Pringle's maneuver and 70% hepatectomy. The elevations of serum liver enzymes (GOT, GPT, mGOT, and LDH) were significantly inhibited in group 4 at 1 and 4 h after reperfusion. Portal venous pressure and the energy charge of liver were also significantly improved in group 4, compared with those in group 3. Endothelin-1 levels of arterial and portal venous blood progressively increased after reperfusion; however, there were no significant differences between the two groups. Leukocyte infiltration into the liver was significantly inhibited in group 4.

CONCLUSION

E5880 pretreatment has protective effects on liver function after 70% hepatectomy with Pringle's maneuver in rabbits.

Activation of Akt/protein kinase B contributes to induction of ischemic tolerance in the CA1 subfield of gerbil hippocampus

Apoptosis plays an important role in delayed neuronal cell death after cerebral ischemia. Activation of Akt/protein kinase B has been recently reported to prevent apoptosis in several cell types. In this article the authors examine whether induction of ischemic tolerance resulting from a sublethal ischemic insult requires Akt activation. Sublethal ischemia gradually and persistently stimulated phosphorylation of Akt-Ser-473 in the hippocampal CA1 region after reperfusion. After lethal ischemia, phosphorylation of Akt-Ser-473 showed no obvious decrease in preconditioned gerbils but a marked decrease in nonconditioned gerbils. Changes in Akt-Ser-473 phosphorylation were correlated with changes in Akt activities, as measured by an in vitro kinase assay. Intracerebral ventricular infusion of wortmannin before preconditioning blocked both the increase in Akt-Ser-473 phosphorylation in a dose-dependent manner and the neuroprotective action of preconditioning. These results suggest that Akt activation is induced by a sublethal ischemic insult in gerbil hippocampus and contributes to neuroprotective ischemic tolerance in CA1 pyramidal neurons.

Involvement of calcium-calmodulin protein kinase but not mitogen-activated protein kinase in light-induced phase delays and Per gene expression in the suprachiasmatic nucleus of the hamster

It is known that Ca(2+)-dependent phosphorylation of cAMP response element binding protein (CREB) and the rapid induction of mPer1 and mPer2, mouse period genes in the suprachiasmatic nucleus (SCN) are associated with light-induced phase shifting. The CREB/CRE transcriptional pathway has been shown to be activated by calcium/calmodulin dependent kinase II (CaMKII) and mitogen-activated protein kinase (MAPK); however, there is a lack of evidence concerning whether the activation of CaMKII and/or MAPK elicited by photic stimuli are associated with the change in Per gene expression and behavioral phase shifting. In this experiment, we found there was an inhibitory effect by KN93, CaMKII inhibitor, on hamster Per1 and Per2 expression in the SCN and on phase delays in wheel running rhythm induced by light pulses. PD98059 and U0126, MAPK kinase inhibitors, however, affected neither light-induced Per1 and Per2 expression nor behavioral phase delays, even though PD98059 attenuated the light-induced phosphorylation of MAPK in the SCN. The present findings demonstrate that the light-induced activation of CaMKII plays an important role in the induction of Per1 and Per2 mRNA in the hamster SCN as well as phase shifting. These results suggest that gated induction of Per1 and/or Per2 genes through CaMKII-CREB/CRE accompanied with photic stimuli may be a critical step in phase shifting.

Fatigue characteristics of ultra high molecular weight polyethylene with different molecular weight for implant material

In order to investigate the effect of molecular weight on fatigue characteristics in the ultra high molecular weight polyethylene (UHMWPE), tension-tension fatigue tests of notched specimens were carried out in the present study. The effects of frequency and stress ratio on the fatigue characteristics were also investigated and fractography was discussed. The fatigue strength does not increase with increasing molecular weight. The fatigue strength might be influenced by the high degree of crystallinity in spite of the decreased tie molecule density in this study. Almost no effect of frequency on the number of cycles to failure can be observed. However, the higher the frequency, the higher the crack tip temperature. The effects of heat and strain rate on the fatigue strength must be considered in polymer materials. At a high stress ratio, the stress-number of cycles to failure (S-N) curves shift to high number cycles to failure side. Both stress amplitude and mean stress influence the fatigue life of UHMWPE.

Genetic polymorphisms of CC chemokine receptor 3 in Japanese and British asthmatics

Whole genome scan analyses have revealed that chromosomal region 3p21-24, which contains a gene cluster of CC chemokine receptors such as CCR3, is possibly linked to asthma. Because CCR3 ligands play a pivotal role in the selective recruitment and activation of inflammatory cells in the asthmatic airway, the authors examined whether there is any association between asthma and the CCR3 gene polymorphisms. Three polymorphisms were identified using the single stranded conformational polymorphism method in Japanese (Asian) and British (Caucasian) subjects; one silent mutation T51C and two missense mutations G824A and T971C. These polymorphisms were examined in 391 Japanese subjects (210 asthmatics and 181 nonasthmatic controls) and 234 British subjects (142 asthmatics and 92 nonasthmatic controls). Asthma diagnosis was based on episodic symptoms, documented wheeze, and the presence of reversible airflow limitation. CCR3 T51C demonstrated a significant association with the diagnosis of asthma in the British population (odds ratio 2.35, p<0.01), but not in the Japanese population. Multiple logistic regression analysis also showed that CCR3 T51C was associated with asthma (odds ratio 2.83, p < 0.02), independent of atopic phenotypes such as high levels of total or house dust mite-specific immunoglobulin-E in serum. In conclusion, a significant association between asthma and CCR3 T51C polymorphism localized on chromosome 3p21 was found.

SHPS-1 regulates integrin-mediated cytoskeletal reorganization and cell motility

The transmembrane glycoprotein SHPS-1 binds the protein tyrosine phosphatase SHP-2 and serves as its substrate. Although SHPS-1 has been implicated in growth factor- and cell adhesion-induced signaling, its biological role has remained unknown. Fibroblasts homozygous for expression of an SHPS-1 mutant lacking most of the cytoplasmic region of this protein exhibited increased formation of actin stress fibers and focal adhesions. They spread more quickly on fibronectin than did wild-type cells, but they were defective in subsequent polarized extension and migration. The extent of adhesion-induced activation of Rho, but not that of Rac, was also markedly reduced in the mutant cells. Activation of the Ras-extracellular signal-regulated kinase signaling pathway and of c-Jun N-terminal kinases by growth factors was either unaffected or enhanced in the mutant fibroblasts. These results demonstrate that SHPS-1 plays crucial roles in integrin-mediated cytoskeletal reorganization, cell motility and the regulation of Rho, and that it also negatively modulates growth factor-induced activation of mitogen-activated protein kinases.

A case of poorly differentiated hilar lung adenocarcinoma of an unidentified histological type

The patient was a 74-year-old man, a physician, whose chief complaint was an unproductive cough. The shadow of a mass was seen at the hilum of the left lung, and the mediastinal lymph nodes on both sides were swollen. No histological diagnosis was obtained even after bronchoscopy, including transbronchial needle aspiration biopsy, but large-cell carcinoma of the lung was diagnosed on the basis of ultrasound-guided biopsy of a shadow in the liver suspected of being a metastatic tumor (T2N3M1, Stage IV). Two courses of chemotherapy (CBCDA + VDS) failed to gain any improvement, and the pain resulting from recurrent bone metastases was managed mainly by the administration of the best supportive care. The patient was readmitted to the hospital after development of numbness in the right upper extremity followed by complication of pneumonia and heart failure, and he passed away. Autopsy revealed a primary hilar lung tumor with a histological diagnosis of poorly differentiated adenocarcinoma.