Efficacy of oral magnesium administration on decreased exercise tolerance in a state of chronic sleep deprivation

We have previously reported that chronic sleep deprivation causes a deficiency of intracellular magnesium (Mg) and decreased exercise tolerance. The aim of this study was to clarify whether oral administration of Mg could be effective in restoring the exercise tolerance that is decreased by chronic sleep deprivation. A bicycle ergometer cardiopulmonary exercise test was performed by 16 healthy volunteers (mean age 21.9 years). They were divided into 2 groups: 8 received doses of 100 mg of Mg orally per day for 1 month (Mg group) and the remaining 8 received no Mg and served as the control group. The study conditions were designed as follows: (1) the usual state (good sleep); and (2) the sleep-deprived state (sleeping time up to 60% less than the usual state for 1 month). The ratio of intracellular Mg content of the sleep-deprived state to the usual sleep state was significantly higher in the Mg group (p<0.05) than the untreated control group. There was no difference between the sleep-deprived state and the usual state with regard to anaerobic threshold and peak oxygen uptake in the Mg group, whereas both of these decreased in the sleep-deprived state in the control group. These results indicate that decreased exercise tolerance observed in the sleep-deprived state could be improved by oral Mg administration.

Oxidative stress and mitochondrial damage precedes gastric mucosal cell death induced by ethanol administration

Although it has been speculated that active oxidants and mitochondrial membrane damages play roles in ethanol-induced gastric mucosal damages, its detail remains unknown. The present study was designed to investigate whether ethanol induces oxidative stress and mitochondrial permeability transition (MPT) before cell death of gastric mucosal cells. Rat gastric mucosal cells (RGM-1) were kept in serum-free Dulbecco's modified Eagle's medium before addition of various concentrations of ethanol. Nuclear morphological aftemations and membrane barrier dysfunction of RGM-1 cells were assessed by staining with Hoechst 33342 and propidium iodide, respectively. To assess the contribution of oxygen-derived free radicals and intracellular glutathione, scavenger of hydrogen peroxide and the hydroxyl radical, N,N-dimethylthiourea, glutathione precursor, N-acetyl-L-cysteine, and an inhibitor of alcohol dehydrogenase, 4-methylpyrazole were added before treatment with ethanol. To investigate MPT, calcein and tetramethylrhodamine methyl ester were loaded before addition of ethanol, and the changes of fluorescence intensity were monitored using a laser scanning confocal microscope. Ethanol (>5% v/v) dose-dependently increased the number of propidium iodide-positive cells, suggesting a diminished barrier function of cell membrane. After addition of ethanol, mitochondria were filled quickly with calcein indicating MPT, which was accompanied by mitochondrial depolarization, as shown by loss of tetramethylrodamine methyl ester before cell death. Ethanol-induced cell death was significantly attenuated by simultaneous incubation with either N,N-dimethylthiourea or N-acetyl-L-cysteine, suggesting the importance of intracellular redox states in inducing cellular damage, whereas such change was not attenuated by 4-methylpyrazole. Present results suggest that ethanol treatment induces intracellular oxidative stress and produces MPT and mitochondrial depolarization, which are preceding cell death in gastric mucosal cells. Intracellular antioxidants, such as glutathione, may have a significant protective action against ethanol in gastric mucosal cells.

[Application of hammerhead ribozyme targeting telomerase molecule for cancer therapy]

Because telomerase is expressed in most cancer cells, but not in most normal somatic cells, telomerase is a promising target molecule of human cancer therapy. To reduce telomerase activity in cancer cells, a hammerhead ribozyme is a choice. The RNA component of telomerase (hTR) is an essential molecule for telomerase, therefore hammerhead ribozyme against it can directly interfere with the telomerase activity. The expression level of hEST2, a catalytic subunit of telomerase correlates well to telomerase activity. Hammerhead ribozyme against hEST2 mRNA, therefore, will reduce telomerase activity by breaking its transcript down. Although hammerhead ribozyme can be designed to target any particular three-base sequences; it is still difficult to predict its efficiency in vivo. Application of hammerhead ribozyme targeting hTR is discussed.

PMA-induced reduction in invasiveness is associated with hyperphosphorylation of MARCKS and talin in invasive bladder cancer cells

Protein kinase C (PKC) plays a critical role in signal transduction for a variety of cell activation processes. Enhanced PKC activity is often found in cancer cells that show marked invasive and/or metastatic potential. Thus, a specific PKC inhibitor may serve as a tool to reduce invasive or metastatic potential of cancer cells. We show here that phorbol 12-myristate 13-acetate (PMA), a PKC activator, also reduces invasiveness of EJ invasive transitional carcinoma cells. PMA-induced reduction in invasiveness was parallel with inhibition of cell motility. PMA neither induced E-cadherin expression nor augmented cell-matrix adhesion of EJ cells. PMA caused retraction of microspikes from the rim of the cells and consequently rounding of the cellular rim, and the disappearance of microfilaments from the cytoplasm. PMA at 10(-7) M, at which concentration the motility of EJ cells was completely inhibited, down-regulated PKC activity over 5 hr after transient translocation of PKC activity to the membrane fraction. At the same time, PMA induced hyperphosphorylation of MARCKS and talin. During the process of cell movement, actin-binding proteins are in a cycle of phosphorylation and dephosphorylation. Once this cycle is interrupted, cells can no longer maintain the dynamics of cytoskeletal structure. We suggest that retention of the hyperphosphorylated state of MARCKS and talin is responsible for the mechanism(s) by which PMA produces inhibitory activity against invasiveness of EJ cells.

Value of glutathione S-transferase pi and the oncogene products c-Jun, c-Fos, c-H-Ras, and c-Myc as a prognostic indicator in endometrial carcinomas

OBJECTIVE

To examine the relationship between the expressions of glutathione S-transferase pi (GST-pi) and four oncogene products, c-Jun, c-Fos, c-H-Ras, and c-Myc, and clinicopathological prognostic factors and patients' prognosis in endometrial carcinomas, and to assess their prognostic value in endometrial carcinomas.

METHODS

Specimens of endometrial carcinoma obtained from 63 patients were investigated immunohistochemically using respective specific antibodies.

RESULTS

The overall positive rates in 63 carcinoma specimens were 34.9% for GST-pi, 44.4% for c-Jun, 34.9% for c-Fos, 47.6% for c-H-Ras, and 54.0% for c-Myc. Multivariate analysis revealed that GST-pi expression correlated independently with paraaortic lymph node (PAN) metastasis, and c-Jun expression was independently related to pelvic lymph node (PLN) and PAN metastasis. The prognosis of patients with a GST-pi-positive tumor was significantly poorer than that of those with a GST-pi-negative tumor (P < 0.05). The patients with c-Jun-positive tumor also had a significantly worse prognosis than those with c-Jun-negative tumor (P < 0.05). No significant relationship between the expressions of the remaining three oncogene products, c-Fos, c-H-Ras, and c-Myc, and the examined prognostic factors and clinical outcome was apparent.

CONCLUSION

These results suggest that the expressions of GST-pi and c-Jun may reflect the metastatic potential of endometrial carcinomas and that their expressions of endometrial carcinoma may be useful as a prognostic indicator for predictive testing.

Telomerase activity in the female reproductive tract and neoplasms

OBJECTIVE

To study a possible utility of telomerase determination for cancer diagnosis.

METHODS

In a total of 227 tissue samples comprising 114 normal tissues of the reproductive age, 10 fallopian tubes of the postmenopausal age, and 103 neoplastic tissues from female reproductive tracts, telomerase activity was determined. Using densitometrical analysis, telomerase activity was compared between carcinoma tissues and normal counterparts.

RESULTS

A total of 97.3% (71/73) of cancer samples comprising ovarian carcinoma, endometrial carcinoma, and epidermoid carcinoma of the cervix and 89.5% (77/86) of the epithelia of the reproductive-aged uterus and fallopian tube showed telomerase activity. The epithelia of the fallopian tube of reproductive age showed significantly higher frequency of positivity (16/18) than the postmenopausal epithelia of the tube (3/10). No difference in telomerase activity was found between endometrial carcinomas and normal proliferative endometria. A significantly higher activity was found in ovarian epithelial carcinoma and epidermoid carcinoma of the cervix than in normal counterparts, although 92% (11/12) of the normal exocervix and 30% (3/10) of the normal ovary showed telomerase activity.

CONCLUSIONS

Most epithelia of the female reproductive tract maintain telomerase activity during the reproductive age. Therefore, the detection of malignancies by telomerase determination may be feasible in ovarian carcinoma and epidermoid carcinoma of the cervix, but requires accurate quantification of telomerase activity.

Telomerase activity in the human endometrium throughout the menstrual cycle

In a total of 41 endometrial tissue samples, the relationship between telomerase activity and proliferating cell nuclear antigen (PCNA) labelling index was studied. In samples of endometrium from the proliferative phase of the menstrual cycle, telomerase activity was found in 15 out of 17 cases (88%). Two samples from the early proliferative phase showed negative telomerase activity and a low PCNA labelling index. However, three out of 16 samples of early secretory phase endometrium showed telomerase activity and a PCNA labelling index. In mid- to late secretory phase endometrium, in menopausal endometrium and in decidualized endometrium induced by progesterone neither telomerase activity nor PCNA labelling was found. These results suggest that telomerase activity of the endometrium may be correlated with the proliferative potential of the epithelial cells and that its activity may be regulated by oestrogen.

A case of concurrent uterine cervical adenocarcinoma and renal-cell carcinoma, and subsequent vaginal metastasis from the renal-cell carcinoma

We report a case of concurrent uterine cervical adenocarcinoma and renal-cell carcinoma and a subsequent vaginal metastasis from the renal-cell carcinoma. The renal-cell carcinoma, which was located in the upper pole of the right kidney, was detected incidentally by preoperative CT scanning. We simultaneously performed in a timely manner radical hysterectomy, pelvic and paraaortic lymphadenectomies, and a right nephrectomy. Subsequently, however, the patient suffered from vaginal metastasis arising from the renal-cell carcinoma. As a result of this case, we emphasize the importance of making a thorough preoperative assessment prior to performance any definitive surgery for a gynecologic malignancy.

Lymphoma arising in mucosa-associated lymphoid tissue of the duodenal bulb

We report a case of low-grade B-cell lymphoma of the duodenal bulb arising from mucosa-associated lymphoid tissue. A barium swallow and an endoscopic examination showed multiple elevated, irregularly contoured lesions limited to the duodenal bulb. Endoscopic biopsy specimens were highly suggestive of non-Hodgkin's lymphoma. The resected specimen showed a gyriform mucosal elevation measuring 3 x 2cm in extent, with multiple small polypoid elevations scattered around it. Histologically, the small lymphocytes constituting the tumor infiltrated the duodenal mucosa and submucosa. The neoplastic centrocyte-like cells tended to grow around reactive lymphoid follicles and to invade epithelial structures, forming characteristic lymphoepithelial lesions. Monoclonal proliferation of the lymphoid tissue was demonstrated by the polymerase chain reaction method. The histologic appearance and the demonstration of monoclonality fulfilled the criteria for malignant lymphoma arising from mucosa-associated lymphoid tissue, which is extremely rare in the duodenum.

Dihydroheptaprenyl and dihydrodecaprenyl monophosphates induce apoptosis mediated by activation of caspase-3-like protease

Dolichyl phosphate, an essential carrier lipid in the biosynthesis of N-linked glycoprotein, has been found to induce apoptosis in rat glioma C6 cells and human monoblastic leukemia U937 cells. In the present study, dolichyl phosphate and structurally related compounds were examined regarding their apoptosis-inducing activities in U937 cells. Dihydroheptaprenyl and dihydrodecaprenyl phosphates, of which isoprene units are shorter than that of dolichyl phosphate, induced apoptosis in U937 cells. This phenomenon occurred in a dose- and time-dependent manner, as seen with dolichyl phosphate-induced apoptosis. Derivatives of the same isoprene units of dolichyl phosphate, such as dolichol, dolichal or dolichoic acid, did not induce DNA fragmentation. Farnesyl phosphate and geranylgeranyl phosphate also failed to induce apoptosis. During apoptosis, the caspase family of cysteine proteases play important roles. We observed that apoptosis induced by dihydroprenyl phosphate was mediated by caspase-3-like (CPP32-like) activation but not by caspase-1-like (ICE-like) activation. This caspase-3-like activation was inhibited by a specific inhibitor of caspase-3, DEVD-CHO, but not by an caspase-1 inhibitor YVAD-CHO. We interpret these results to mean that dihydroprenyl phosphates with more than seven isoprene units have apoptosis-inducing activity and that their signal is mediated by caspase-3-like activation.

DNA cleavage and 8-hydroxydeoxyguanosine formation caused by tamoxifen derivatives in vitro

DNA damage caused by tamoxifen and its derivatives was examined by estimating the conversion of supercoiled pUC18 plasmid DNA to linear form by means of agarose gel electrophoresis. N-Desmethyltamoxifen induced DNA cleavage and its effect was enhanced by the addition of reducing agents such as dithiothreitol, NADPH and 2-mercaptoethanol. 4-Hydroxytamoxifen itself had little effect, but the cleavage was slightly enhanced by the addition of reducing agents. DNA damage was higher with alpha-hydroxytoremifene than with alpha-hydroxytamoxifen, which had a prominent effect only at high concentration. The cleavage by alpha-hydroxy derivatives were not enhanced by reducing agents. No damage was induced by tamoxifen, toremifene, 3-hydroxytamoxifen or N-desmethyltoremifene. The DNA cleavage by N-desmethyltamoxifen was inhibited by the addition of EDTA, mannitol, sodium azide, methionine, catalase and superoxide dismutase. The formation of 8-hydroxy-2'-deoxyguanosine was also examined with calf thymus DNA in vitro. A slight increase of its level was found with 4-hydroxytamoxifen in the presence of dithiothreitol and also with N-desmethyltamoxifen in the presence of NADPH, but alpha-hydroxytoremifene and alpha-hydroxytamoxifen were ineffective. These experimental data suggest that among metabolites of tamoxifen, N-desmethyltamoxifen and probably also 4-hydroxytamoxifen cause oxidative DNA damage in which redox cycling is involved. The DNA damage by alpha-hydroxytoremifene appears to involve a different mechanism from that by N-desmethyltamoxifen. Tamoxifen and toremifene are possibly metabolized to the forms contributing to DNA damage.

[High-resolution CT findings in cytomegalovirus pneumonitis after bone marrow transplantation]

In order to explore the high-resolution CT (HRCT) findings of cytomegalovirus (CMV) pneumonitis after bone marrow transplantation, we retrospectively reviewed the HRCT findings in nine patients with CMV pneumonitis cytologically proven by bronchoalveolar lavege. In 67% of cases, HRCT showed ground-glass attenuation. Consolidation and bronchial wall thickening were demonstrated in 33%, pleural effusion in 22%, and micro centrilobular nodules, bronchiectasis, and reticulation in 11%, respectively. Lymphadenopathy and masses were not seen. The areas of ground-glass attenuation were distributed bilaterally in all cases, diffusely in 67%, centrilobularly in 50%, and panlobularly in 50%. Subpleural lung regions were spared in 83%. The areas of consolidation were bilateral in 67%, nonsegmental in 67%, and involved the lower lobe in all cases. A total of 25 follow-up HRCT were performed in six patients. Small centrilobular ground-glass opacities disappeared after treatment in one patient. Micro centrilobular nodules vanished after treatment in one patient. Small centrilobular ground-glass opacities developed into consolidation and resolved after treatment in one patient. In one patient, diffuse ground-glass opacities progressed to consolidation, and the patient died due to respiratory failure. No abnormal findings were observed in two patients. It may be considered that in the early phase of CMV pneumonitis HRCT shows small or micro centrilobular ground-glass opacities and nodules and that in the advanced phase these lesions progress to dense alveolar opacities as CMV infection advances, although a variety of HRCT appearances is observed in the course of CMV pneumonitis.

Differences in virus receptor for type I and type II feline infectious peritonitis virus

Feline infectious peritonitis viruses (FIPVs) are classified into type I and type II serogroups. Here, we report that feline aminopeptidase N (APN), a cell-surface metalloprotease on the intestinal, lung and kidney epithelial cells, is a receptor for type II FIPV but not for type I FIPV. A monoclonal antibody (MAb) R-G-4, which blocks infection of Felis catus whole fetus (fcwf-4) cells by type II FIPV, was obtained by immunizing mice with fcwf-4 cells which are highly susceptible to FIPV. This MAb also blocked infection of fcwf-4 cells by type II feline enteric coronavirus (FECV), canine coronavirus (CCV), and transmissible gastroenteritis virus (TGEV). On the other hand, it did not block infection by type I FIPVs. MAb R-G-4 recognized a polypeptide of relative molecular mass 120-130 kDa in feline intestinal brush-border membrane (BBM) proteins. The polypeptide possessed aminopeptidase activity, and the first 15 N-terminal amino acid sequence was identical to that of the feline APN. Feline intestinal BBM proteins and the polypeptide reacted with MAb R-G-4 (feline APN) inhibited the infectivity of type II FIPV, type II FECV, CCV and TGEV to fcwf-4 cells, but did not inhibit the infectivity of type I FIPVs.

Surgical stress inhibits the growth of fibroblasts through the elevation of plasma catecholamine and cortisol concentrations

To investigate the influence of surgical stress on fibroblast proliferation, serum samples were collected from 12 patients within 1 week after they had undergone gastrointestinal surgery, and the effect of these samples on the growth of fibroblasts from neonatal mice were evaluated by an in vitro assay. In addition, the course of the postoperative plasma levels of the stress-induced hormones, adrenaline, noradrenaline, and cortisol, and the direct effects of these substances on the proliferation of fibroblasts, were also analyzed. The sera collected from patients on the 1st, 3rd, and 7th postoperative day had a significant antiproliferative effect on the growth of fibroblasts. The evaluation of the levels of plasma catecholamines (adrenaline and noradrenaline) and cortisol revealed elevated postoperative concentrations of these substances in three patients, and the peaks were seen on the 1st or 3rd postoperative day. Furthermore, the growth of cultured fibroblasts was inhibited when each of these substances was added to the medium at a concentration comparable to the level found in the postoperative sera. These results suggest that adrenaline, noradrenaline, and cortisol may thus be among the circulating fibroblast growth inhibitors in postoperative patients and that surgical stress affects the formation of granulation in an inhibitory manner through the elevation of these stress-induced substances.

[Circadian chemotherapy in cancer patients]

Continuous infusion of 5-FU at night was performed for four patients: three had liver metastasis (one with gastric cancer and two with rectal cancer) and one had local recurrence of rectal cancer. The chemotherapy schedule was 400 mg/m2/day 5-FU intraarterial or intravenous infusion from 6:00 p.m. to 6:00 a.m. for five days repeated every 3 weeks. There were one complete response, two partial responses and one with no change. It is expected that the chemotherapy of 5-FU at night will result in a high efficacy and lower toxicity.

A possible immunosuppressant, cycloprodigiosin hydrochloride, obtained from Pseudoalteromonas denitrificans

Cycloprodigiosin hydrochloride (cPrG.HCl), a member of the prodigiosin family, is a red pigment obtained from the marine bacterium Pseudoalteromonas denitrificans. cPrG.HCl markedly suppressed 3H-thymidine incorporation by concanavalin A stimulated murine splenocytes but had little effect on lipopolysaccharide dependent 3H-thymidine incorporation, indicating that cPrG.HCl acts as a selective inhibitor of T cell proliferation in the same way as other members of the prodigiosin family. cPrG.HCl inhibited the proliferation of the PMA stimulated Jurkat cells through an apoptotic process. Intriguingly, cPrG.HCl inhibited the H+ translocation by vacuolar type ATPase in chromaffin granule membranes without any effect on either its ATPase activity nor on the membrane conductance of phospholipid bilayers, suggesting that cPrG.HCl selectively uncouples H+ translocation from the ATPase reaction rather than acting as a non-specific ionophore. Since crystalline cPrG.HCl is highly stable, it raises the possibility of its therapeutic use as an immunosuppressant.

Evidence for active acetylcholine metabolism in human amniotic epithelial cells: applicable to intracerebral allografting for neurologic disease

Human amniotic epithelial (HAE) cells have been used for allotransplantation in patients with lysosomal storage disease due to lack of expression of HLA antigens. Previously, we have reported the expression of differentiation markers for both neural stem cells, and neuron and glial cells. In the present study, we investigated the presence of choline acetyltransferase (ChAT) and acetylcholine (ACh) in HAE cells using different experimental approaches. Cultured HAE cells showed strong immunoreactivity against ChAT antibody. ChAT activity in primary cells was 24.9 +/- 8.5 pmol/mg protein/h. Using HPLC with electrochemical detection, ACh was detected in both cell incubation media and cell pellets indicating that these cells synthesize and release ACh in a time-dependent manner. Additional confirmation of this hypothesis was gained from the data obtained from RT-PCR and Western blot analyses which revealed the expression of ChAT mRNA and ChAT protein, respectively, in HAE cells. Results of the present study suggest that HAE cells can possibly be applied for intracerebral allografting to treat neurologic diseases in which cholinergic neurons are damaged.

Structure and expression of carp mitogen-activated protein kinases homologous to mammalian JNK/SAPK

Two distinct stress-activated protein kinase (JNKa and b) cDNAs were isolated from a carp ovary cDNA library. These cDNAs contained a full-length open reading frame encoding 427 amino acid residues with a predicted mass of 48.6 kDa. The deduced amino acid sequences of JNKa and b were 95.8% identical, with 18 residues replaced, and showed a high degree of sequence similarity to mammalian JNK/SAPK subgroup including the common dual phosphorylation motif of TPY. By Northern blot analysis, the carp JNKs were found to be abundant in the brain and ovary. Detailed study by RT-PCR assay revealed ubiquitous expression of JNKb, although expression of JNKa was specific to the brain and ovary. The high level expression of both JNKa and b in the ovary implies that JNKs play an important role in egg maturation or ectogenetic early development.

Mucosal interleukin-8 is involved in neutrophil migration and binding to extracellular matrix in inflammatory bowel disease

OBJECTIVES

In this study, our purpose was to determine whether locally generated interleukin-8 (IL-8) is involved in neutrophil migration and binding to extracellular matrix, using the colonic mucosal specimens obtained from patients with inflammatory bowel disease (IBD).

METHODS

Levels of IL-8 secreted in the organ cultures were measured by enzyme-linked immunosorbent assay. Chemotactic activity and binding capacity of neutrophils were induced by the organ culture supernatants.

RESULTS

Significantly higher levels of IL-8 were secreted in patients with IBD, and its elevation was more prominent in patients with active ulcerative colitis. The organ culture supernatants induced higher chemotactic activity and binding capacity of neutrophils in patients with IBD, especially in those with active ulcerative colitis, compared with controls. These effects were inhibited significantly when the supernatants were submitted to preincubation with neutralizing anti-IL-8 antibody.

CONCLUSIONS

Increased mucosal generation of IL-8 may attract neutrophils from the circulation into the inflammatory site and induce binding of neutrophils in the interstitial tissue, contributing to accumulation and activation of neutrophils in the affected mucosa with IBD.

CPP32 activation during dolichyl phosphate-induced apoptosis in U937 leukemia cells

Treatment of U937 cells with dolichyl phosphate led to an increase in the activity of the ICE family protease CPP32, accompanied with cleavage of pre-CPP32 to generate p17. Peptide inhibitors YVAD-cmk and Z-Asp-CH2-DCB (specific to ICE) and DEVD-CHO (specific to CPP32) blocked the dolichyl phosphate-induced apoptosis. The dolichyl phosphate-induced increase of CPP32 activity was inhibited by adenylate cyclase inhibitors, SQ 22536 and 2',5'-dideoxyadenosine. Dolichyl phosphate caused a transient increase of intracellular cAMP concentration. The results suggest that modulation of cAMP synthesis due to the stimulation of adenylate cyclase by dolichyl phosphate plays a critical role in CPP32 activation and apoptosis.

Introduction of p21(Waf1/Cip1) gene into a carcinoma cell line of the uterine cervix with inactivated p53

In carcinomas of the uterine cervix of which p53 is frequently inactivated by papilloma viruses, gene transfer of p21, effector of p53, is an alternative tool to suppress cell growth. We introduced the p21 gene into HeLa cells. The transfectant with p21 showed a significant growth retardation by blockage of G1 to S transfer of the cell cycle. This cell line showed significantly reduced anchorage-independent growth as well as attenuated telomerase activity. These data suggest that gene transfer of p21 is an effective tool to lead carcinoma cells with inactivated p53 into less malignant phenotype.