Post-transcriptional regulation of plasminogen activator inhibitor-1 by intracellular iron in cultured human lung fibroblasts--interaction of an 81-kDa nuclear protein with the 3'-UTR

The proteinase inhibitor, type-1 plasminogen activator inhibitor (PAI-1), is a major regulator of the plasminogen activator system involved in plasmin formation and fibrinolysis. The present study explores the effects of intracellular iron on the expression of PAI-1 and associated cell-surface plasmin activity in human lung fibroblasts; and reports the presence of a novel iron-responsive protein. ELISA revealed a dose-dependent increase in PAI-1 antigen levels expressed in the conditioned medium of cells treated with deferoxamine, in the three cell lines studied. A concomitant increase in mRNA levels was also observed by Northern analyses. Presaturation with ferric citrate quenched the effect of deferoxamine. Experiments with transcription and translation inhibitors on TIG 3-20 cells demonstrated that intracellular iron modulated PAI-1 expression at the post-transcriptional level with the requirement of de-novo protein synthesis. Electrophoretic mobility shift assay and UV crosslinking assays revealed the presence of an approximately 81-kDa nuclear protein that interacted with the 3'-UTR of PAI-1 mRNA in an iron-sensitive manner. Finally, we demonstrated that the increased PAI-1 is functional in suppressing cell-surface plasmin activity, a process that can affect wound healing and tissue remodeling.

Clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease

BACKGROUND

No method for the clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease (sCJD) has been established except for pathologic examination.

OBJECTIVE

To identify a reliable marker for the clinical diagnosis of MM2-type sCJD.

METHODS

CSF, EEG, and neuroimaging studies were performed in eight patients with MM2-type sCJD confirmed by neuropathologic, genetic, and western blot analyses.

RESULTS

The eight cases were pathologically classified into the cortical (n = 2), thalamic (n = 5), and combined (corticothalamic) (n = 1) forms. The cortical form was characterized by late-onset, slowly progressive dementia, cortical hyperintensity signals on diffusion-weighted imaging (DWI) of brain, and elevated levels of CSF 14-3-3 protein. The thalamic form showed various neurologic manifestations including dementia, ataxia, and pyramidal and extrapyramidal signs with onset at various ages and relatively long disease duration. Characteristic EEG and MRI abnormalities were almost absent. However, all four patients examined with cerebral blood flow (CBF) study using SPECT showed reduction of the CBF in the thalamus as well as the cerebral cortex. The combined form had features of both the cortical and the thalamic forms, showing cortical hyperintensity signals on DWI and hypometabolism of the thalamus on [18F]2-fluoro-2-deoxy-d-glucose PET.

CONCLUSION

For the clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease, cortical hyperintensity signals on diffusion-weighted MRI are useful for the cortical form and thalamic hypoperfusion or hypometabolism on cerebral blood flow SPECT or [18F]2-fluoro-2-deoxy-d-glucose PET for the thalamic form.

Treatment strategy for Boerhaave's syndrome

Esophageal rupture is a potentially mortal condition. Rapid and correct diagnosis, and urgent surgical treatment with esophagectomy is indicated, but conservative and other surgical treatments have also been reported recently. The treatment strategies for esophageal rupture are discussed here, based on our experiences with four cases during the last 10 years. They were admitted urgently and each was treated by a different method. Three of them underwent emergency operations, one undergoing primary closure of the ruptured esophagus, another received a T-tube insertion from the ruptured site with omental flap, and the third an esophagogastrectomy. The fourth case was treated conservatively. All patients survived and were discharged 36-144 days post treatment. One of them was readmitted for debridement of necrotic rib. In conclusion, the prompt and accurate diagnosis of esophageal rupture is crucial for a subsequent successful treatment. Conservative treatment or operation including esophagectomy will be determined by the severity of the condition.

Simplified method for cryopreservation of islets using hydroxyethyl starch and dimethyl sulfoxide as cryoprotectants

Cryopreservation is an ideal method for long-term storage of human islets. Dimethyl sulfoxide (DMSO) has been used as an intracellular cryoprotectant. However, because of its toxicity, DMSO has to be added stepwise and diluted stepwise with sucrose. We combined hydroxyethyl starch (HES) as an extracellular cryoprotectant with DMSO to simplify the freeze-thawing procedure. Islets were isolated from the pancreas of beagle dogs by an automated digestion method and Ficoll purification. After overnight culture, the islets were cryogeneically stored using cooling by a programmed freezing system. After 4-week storage in liquid nitrogen, the container was rapidly thawed in a 37 degrees C water bath. The function of the islets was assessed upon static incubation immediately after thawing, showing a recovery rate of 71.16% +/- 20.14% and a stimulation index of 1.80 +/- 0.78. In conclusion use of HES allowed a decrease in DMSO concentration and simplified the freeze-thawing procedure for islets.

Long-term follow-up study of gastric adenoma/dysplasia

BACKGROUND AND STUDY AIMS

The natural course of gastric adenoma/dysplasia, regarded as a precancerous lesion, is still uncertain.

PATIENTS AND METHODS

From 1976 to 2000, 48 lesions in 43 patients (37 men, six women; mean age 59 years) were diagnosed as having gastric adenoma/dysplasia based on their first biopsies. These lesions were followed for a median of 4.7 years (mean 6 years, range 3-18 years) to evaluate the risk of progression to invasive carcinoma. Retrospectively, histological diagnoses of the biopsy and resected specimens were reclassified according to the Vienna classification of gastrointestinal epithelial neoplasia, and macroscopic changes were evaluated.

RESULTS

The diagnosis at first biopsy of the 48 lesions was low-grade adenoma/dysplasia (LGD; category 3) in 38 cases and high-grade adenoma/dysplasia (HGD; category 4) in 10 cases. Ninety-seven percent of the LGD (category 3) lesions (37 of 38) showed no histological changes during the follow-up period; the remaining lesion progressed to noninvasive carcinoma (category 4). Macroscopically, 84 % (32 of 38) of the LGD lesions (category 3) showed no remarkable changes in size, while 11 % (four of 38) shrank and 5 % (two of 38) grew larger. Nine of the 10 HGD lesions (category 4) remained histologically unchanged, while the other progressed to intramucosal carcinoma (category 5). Macroscopically, four of the 10 HGD lesions (category 4) (40 %) showed no remarkable changes in size, while the remaining six (60 %) grew larger.

CONCLUSIONS

LGD lesions (category 3) have a quite low risk of progressing to HGD or noninvasive carcinoma (category 4), and were never observed to progress to invasive carcinoma (category 5). HGD lesions (category 4) occasionally progressed to intramucosal carcinoma (category 5), with no instance of invasion into the submucosa or beyond.

The effects of pitch tilt on postrotatory nystagmus in cats

When the head is tilted away from the upright position immediately after termination of earth-vertical axis (EVA) head rotation at a constant velocity, the rotation axis of postrotatory nystagmus (PRN) is gradually directed toward gravity (spatial reorientation). During roll tilt, the extent of the axis shift varies among species. In cats, the reorientation is limited to about 30-45 degrees of head tilt. In the present study, we examined features of PRN during pitch tilt in cats. The animals were rotated about EVA at a constant velocity of 100 degrees /s for 120 s. Within 2 s after stopping EVA rotation, the animals were tilted toward the pitch plane by as much as +/-90 degrees (nose-down or nose-up) in steps of 15 degrees. Eye movements were measured with 3D magnetic search coils. The angle of the PRN plane and its slow phase eye velocity (SPV) were measured. The duration of PRN decreased as pitch tilt increased regardless of whether the direction was nose-up or nose-down. The mean time constant of SPV was significantly longer for nose-up than for nose-down. PRN maintained its horizontal orientation without any vertical drift during pitch tilt, but there was little reorientation toward gravity. That is, no significant torsional component of SPV emerged to reorient the eyes according to gravity. Our results indicate that spatial reorientation depends on head orientation. For the PRN responses after pitch tilts in cats, the interactions of semicircular canal and otolith inputs in the central vestibular system might be vestigial.

Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome in Nagano, Japan: clinical, radiological, and cytokine studies of 13 patients

OBJECTIVE

Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) has so far been reported almost exclusively from the USA and Europe. We carried out this study to define the clinical characteristics of this syndrome in Japanese patients.

METHODS

Prospectively, we identified 13 Japanese patients with RS3PE (5 men and 8 women, age 72.7 +/- 11.8 years (mean +/- SD)) without underlying neoplasm. Their clinical features were summarized, pertinent laboratory data including serum/synovial interleukin-6 (IL-6) concentrations were obtained, and extensive radiologic studies using magnetic resonance imaging and 67gallium-citrate (67Ga) whole body scintigram were performed.

RESULTS

All patients suffered from proximal arthralgia/myalgia in addition to typical distal symptoms of RS3PE, and all experienced systemic symptoms such as fever, malaise, and weight loss. In laboratory examinations, anemia and elevated inflammatory markers were often remarkable. Magnetic resonance imaging showed severe tenosynovitis of the hands. 67Ga-scintigram revealed radioisotope accumulation in both proximal and distal joints of the extremities. IL-6 activity was markedly elevated both in the serum (mean 82.4 +/- 62.1 (SD) pg/ml, normal range 0.157-2.94) and in the synovial fluid (mean 3350 +/- 633 (SD) pg/ml).

CONCLUSION

Compared with cases reported previously from the USA/Europe, Japanese patients with RS3PE are characterized by more prominent systemic symptoms/signs associated with marked inflammatory responses including elevated IL-6 activity. All patients had proximal as well as distal synovitis which could be demonstrated by 67Ga-scintigram. These clinical features were very similar to those of polymyalgia rheumatica, suggesting that RS3PE and polymyalgia rheumatica are closely related disorders which may have a common pathogenesis.

Cooperative induction of 15-lipoxygenase in rheumatoid synovial cells by IL-4 and proinflammatory cytokines

OBJECTIVE

To clarify the role of interleukin-4 (IL-4) in the expression of 15-lipoxygenase (15-LOX), whose metabolities are known to suppress the inflammatory reaction, in freshly prepared rheumatoid synovial cells.

METHODS

Adherent synovial cells were prepared by enzymatic digestion of synovia obtained from patients with rheumatoid arthritis (RA). Protein expression of 15-LOX was determined by Western blot analysis. The messenger RNAs of 15-LOX were determined by reverse transcription and the polymerase chain reaction (RT-PCR).

RESULTS

Freshly prepared rheumatoid synovial cells did not express 15-LOX at either the mRNA or protein levels. IL-4 induced the protein expression of 15-LOX after 24 hours of culture. Although interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha), major inflammatory cytokines in rheumatoid synovia, did not induce the expression of 15-LOX, IL-4 and these inflammatory cytokines synergistically enhanced the protein expression of 15-LOX. The synergistic effect was also observed at the level of mRNA.

CONCLUSIONS

We demonstrate that IL-4 cooperated with the inflammatory cytokines IL-1 alpha and TNF alpha to enhance the expression of 15-LOX in rheumatoid synovial cells. Since 15-LOX metabolites have potent anti-inflammatory actions, our data suggest that IL-4 might downregulate rheumatoid inflammation via the induction of 15-LOX and its metabolites.

Resting T cells negatively regulate osteoclast generation from peripheral blood monocytes

There is accumulating evidence that T cells may be involved in osteoclastogenesis in a variety of murine systems. However, the precise role of human T cells in the regulation of osteoclast generation is still unclear. To address this issue, we investigated the effect of resting peripheral T cells on receptor activator of NF-kappaB ligand (RANKL)-induced osteoclast generation from human peripheral monocytes. Although osteoclasts were not generated in the culture of human peripheral blood mononuclear cells (PBMC) in the presence of RANKL and macrophage colony-stimulating factor (M-CSF), the addition of cyclosporine A (CsA), a potent inhibitor of T-cell function, resulted in the formation of an increasing number of lacunae resorption on dentine, suggesting T cells may inhibit osteoclast formation. In a coculture of T cells and monocytes, which were isolated from PBMC, T cells inhibited the osteoclast generation from monocytes, as determined by tartrate-resistant acid phosphatase (TRAP) staining and a pit assay using dentine. This inhibition of osteoclast generation by T cells was also observed in a culture of the parathyroid hormone-stimulated SaOS4/3 osteoblast cell line and monocytes. The culture in Transwell plates revealed that the cell-to-cell interaction was not required for the inhibition, suggesting that T-cell cytokines may be responsible for the inhibition. Among inhibitory T-cell cytokines on osteoclastogenesis, granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-gamma (IFN-gamma) were actively produced by CD4 T cells but not CD8 T cells in the coculture of T cells with monocytes, and the neutralizing antibodies to these cytokines partially rescued the T-cell-induced inhibition of osteoclast formation. Although CsA did not affect RANKL-induced osteoclast generation in the culture of monocytes alone, it completely rescued the T-cell-induced inhibition of osteoclast formation and strongly inhibited the production of GM-CSF and IFN-gamma. Thus, we demonstrate that resting T cells negatively regulate the osteoclast generation via production of GM-CSF and IFN-gamma by CD4 T cells and that CsA stimulates the osteoclast generation through the inhibition of the production of these cytokines. These findings provide new insight into therapeutic strategies for immunosuppression-induced bone loss in transplant and other diseases.

Early gastric carcinomas in the cardiac region: diagnosis with double-contrast x-ray studies

BACKGROUND

The ratio of early to advanced gastric carcinomas in the cardiac region is significantly low. It is necessary to establish methods of early diagnosis of gastric carcinomas in the cardiac region.

METHODS

Twenty cases (21 lesions) of early gastric carcinomas in the cardiac region were resected between 1997 and 2001. We studied the macroscopic characteristics of the specimens, films of double-contrast upper gastrointestinal studies before operations, and the detectabilities of findings in each projection.

RESULTS

Four of 21 early gastric carcinomas in the cardiac region were on the anterior wall, 10 were on the lesser curvature, and seven were on the posterior wall. In seven of 21 lesions the carcinomas were not detected in the resected specimens macroscopically; in five, the area of carcinoma was not clearly traced in the resected specimens; and in nine, the area of carcinomas was clearly traced. In the morphologic study, 16 (76.2%), two (9.5%), two (9.5%), and one (4.8%) of the 21 lesions showed the superficial depressed type (IIc), superficial elevated type (IIa), superficial elevated and superficial depressed type (IIa + IIc), flat and superficial depressed type (IIb + IIc), respectively. Mucosal reddening was seen in 11, and mucosal discoloration was seen in one; change of color was not seen in the remaining nine lesions. Twenty lesions were diagnosed as differentiated adenocarcinomas, and one lesion was diagnosed as undifferentiated adenocarcinoma. Radiologically, early gastric carcinomas in the cardiac region had the following features: localized shallow barium deposits, localized abnormal barium coating, and niche and radiolucent lesions. Four (100%) of four lesions on the anterior wall, 10 (100%) of 10 lesions on the lesser curvature, and seven (100%) of seven lesions on the posterior wall were detected in the half-standing, prone, right anterior, oblique projection. Seven (100%) of seven lesions on the posterior wall and 10 (100%) of 10 lesions on the lesser curvature were detected in the half-standing, supine, left anterior, oblique projection.

CONCLUSION

Even though most early gastric carcinomas in the cardiac region demonstrate few macroscopic findings, the half-standing, prone, right anterior, oblique projection and the half-standing, supine, left anterior, oblique projection are useful in the double-contrast studies.

Establishment of feeder-independent cloned caprine trophoblast cell line which expresses placental lactogen and interferon tau

A feeder-independent cloned trophoblast cell line, HTS-1, was established from a mature placenta of Shiba goat (Capra hircus). During the growth phase, single HTS-1 cells exhibited ruffled membranes or lamellipodia often accompanied by elongated cell shape, indicating highly motile nature of the cells. At or near confluence, HTS-1 cells formed monolayers with few sign of cellular overlapping. Binucleate cells were found at a high frequency especially in the peripheral regions of monolayers. In small colonies and the monolayers, majority of HTS-1 cells assumed polygonally shaped cobble-stone like morphology characteristic to epithelial cells, although considerable variations in cellular morphology were observed despite of repeated cloning. Time-lapse video recordings of HTS-1 cells during culture revealed that not only the small colonies but also the monolayers near or at confluence were remarkably motile, often causing extreme elongation of the cells within them. The extremely plastic nature of HTS-1 cells in vitro is likely to be the reflection of the extraordinary capacity of caprine trophoblast cells to be stretched to extreme thinness in vivo as shown by electron microscopy. HTS-1 cells cultured on matrigel are highly invasive, and express MT1-MMP which, in the mouse, has been known to be expressed at the invasive edge of trophoblast both in vitro and in vivo. HTS-1 cells express placental lactogen (PL) and interferon-tau (IFNtau), as confirmed by immunocytochemistry, Western blotting and RT-PCR analysis. Both PL and IFNtau expression in the cells appeared to be down-regulated by cell-cell contact. In the medium conditioned by HTS-1 cells, the presence of secretory form of PL and IFNtau was confirmed by Western blotting. The HTS-1 cell line will serve as a useful in vitro model for the analysis of the molecular and/or cellular mechanisms underlying synepitheliochorial placentation in bovidae animals.

A histopathological and lectin-histochemical study of the lining epithelium in postoperative maxillary cysts

OBJECTIVE

Histopathological and lectin-histochemical characteristics were studied in the lining epithelium of postoperative maxillary cysts (POMC).

MATERIALS AND METHODS

Histological (HE, PAS, AB), immunohistochemical (CD3 and L26) and lectin (wheat germ agglutinin, WGA; Ulex europaeus agglutinin I, UEA-I; concanavalin A, ConA) stainings were performed in the 360 POMC specimens. The number of goblet cells and inflammatory cells was counted and statistically analyzed.

RESULTS

The lining epithelium was classified into three types based on histopathological characteristics; pseudostratified ciliated epithelium (pSCE), transitional epithelium (TE) and stratified squamous epithelium (SSE). Local infiltration of inflammatory cells into the cyst wall was associated with an increased number of goblet cells in the lining epithelium. The observed association between the infiltration of inflammatory cells and an increase in the number of goblet cells was statistically significant in groups with lining pSCE and TE. Glycoconjugate histochemical analysis revealed that the surfaces of the lining epithelium with squamous metaplasia showed an increased degree of staining reactivity with UEA-I, whereas the staining reactivity with ConA was reduced. Goblet cells were able to be stained with WGA and UEA-I, but showed extremely low reactivity with ConA.

CONCLUSION

Changes in the glycoconjugate expression of the metaplastic lining epithelium and goblet cell development play an important role in the local defense mechanisms against inflammatory factors in POMC.

Up-regulation of the urokinase-type plasminogen activator receptor by monocyte chemotactic proteins

The urokinase-type plasminogen activator receptor (uPAR) is a multifunctional molecule involved in migration and adhesion of leukocytes to sites of inflammation. Based on our hypothesis that a chemoattractant can stimulate uPAR expression by its target cell, thereby promoting cell migration, we employed three chemokines [monocyte chemotactic protein (MCP)-1, MCP-2 and MCP-3] as chemoattractants, and examined their effect on uPAR expression in a human monocyte-like cell line, U937. Northern blot analysis demonstrated that all three chemokines tested increased the level of uPAR mRNA in time-dependent and dose-dependent manners. Among them, MCP-3 exhibited the most potent effect. Scatchard analysis showed that incubation with MCP-3 (1 x 10(-8) mol/l) for 16 h resulted in a significant increase in the number of uPAR from (6.8 +/- 0.3) x 10(3) to (10.3 +/- 1.6) x 10(3)/cell, and in a slight increase in the equilibrium dissociation constant, K(d). The effect of anti-uPAR antibodies on MCP-3-induced U937 cell migration across an endothelial cell monolayer and a type I collagen layer was assessed by means of the modified Boyden chamber assay. Although MCP-3 caused a three-fold increase in migration, incubation with an antibody to uPAR markedly abrogated the induced cell migration. These results support our hypothesis and suggest that up-regulation of uPAR in target cells might be an important and common feature of chemoattractants.