Reinvestigation of the virulence of Rhodococcus equi isolates from patients with and without AIDS.

Rhodococcus equi emerged as a zoonotic pathogen of human immunodeficiency virus-infected patients over the last three decades. Two virulence plasmid types of R. equi, pVAPA and pVAPB associated with equine and porcine isolates, have been recognized, and more recently, pVAPN, a novel host-associated virulence plasmid in R. equi, was found in bovine and caprine isolates. We reinvestigated 39 previously reported isolates of R. equi from patients with and without acquired immunodeficiency syndrome (AIDS) by detecting vapA, vapB and vapN using PCR and plasmid profiling. After excluding one isolate that could not be cultured from frozen storage, eight isolates carried a virulence plasmid encoding vapA (pVAPA), 10 carried a virulence plasmid encoding vapB (pVAPB), seven carried a virulence plasmid encoding vapN (pVAPN) and 13 were negative for those genes. Of the 29 isolates from patients with AIDS, 7, 10 and 5 harboured pVAPA, pVAPB and pVAPN respectively. Among nine isolates from patients without AIDS, one and two harboured pVAPA and pVAPN respectively. This study demonstrated that pVAPN-positive R. equi existed in human isolates before 1994 and reaffirmed that equine-associated pVAPA-positive, porcine-associated pVAPB-positive and bovine- or caprine-associated pVAPN-positive R. equi are widely spread globally. Because domestic animals might be major sources of human infection, further research is needed to reveal the prevalence of pVAPN-positive R. equi infection in cattle and goats.

Skin cancer prevention: a possible role of 1,25dihydroxyvitamin D3 and its analogs.

We previously reported that the natural hormone 1,25dihydroxyvitamin D3 (1,25(OH)(2)D(3)) protects human skin cells from ultraviolet radiation (UVR)-induced apoptosis. UVR-induced pre-mutagenic cyclobutane pyrimidine dimers are diminished in number from 0.5h after cessation of UVR in all skin cell types, by treatment with three different Vitamin D compounds: by 1,25(OH)(2)D(3), by the rapid acting, low calcemic analog, 1alpha,25(OH)(2)lumisterol(3) (JN) and by the low calcemic but transcriptionally active hybrid analog 1alpha-hydroxymethyl-16-ene-24,24-difluoro-25-hydroxy-26,27-bis-homovitamin D3 QW-1624F2-2 (QW), which may explain the enhanced cell survival. The rapid response antagonist analog 1beta,25(OH)(2)D(3) (HL) abolished the photoprotective effects of 1,25(OH)(2)D(3) whilst a genomic antagonist, (23S)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9647), had no effect. UVR increased p53 expression in human skin cells, whilst concurrent treatment with 1,25(OH)(2)D(3) further enhanced this effect several fold, at 3 and 6h after UVR. Combined with previously reported lower nitrite levels with 1,25(OH)(2)D(3), this increased p53 expression may favor DNA repair over apoptosis. We now report that topical application of 1,25(OH)(2)D(3) or QW also suppressed solar simulated UV (SSUVR-induced pyrimidine dimers in the epidermis of irradiated hairless Skh:HR1 mice, measured 24h after irradiation. Furthermore, UVR-induced immunosuppression in the mice was markedly reduced by topical application of either 1,25(OH)(2)D(3) or QW. These preliminary results show, for the first time, a protective effect of Vitamin D compounds against DNA photodamage in vivo.

Interstitial pneumonia possibly due to a novel anticancer drug, TS-1: first case report.

A newly approved oral fluoropyrimidine, TS-1, is a dihydropyrimide dehydrogenase (DPD)-inhibiting fluoropyrimidine (DIF) drug. We describe a case of interstitial pneumonia probably caused by TS-1. A peripheral blood lymphocytes stimulating test (DLST) with TS-1 demonstrated a substantial positive reaction. So far only three cases of TS-1-induced interstitial pneumonia have been reported but the relationship between interstitial pneumonia and TS-1 was demonstrated only in this case. Considering that interstitial pneumonia has also been reported with 5-FU, it is necessary in the future to clarify which component of this drug is directly related to interstitial pneumonia.

Different molecular mechanisms of vitamin D(3) receptor antagonists.

Two structurally different antagonists of the nuclear hormone 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)], the 25-carboxylic ester ZK159222 and the 26,23-lactone TEI-9647, have recently been described. In this study, the molecular mechanisms and the efficacy of both antagonists were compared. ZK159222 showed similar potency and sensitivity to 1alpha,25(OH)(2)D(3) in ligand-dependent gel shift assays using the vitamin D receptor (VDR), the retinoid X receptor, and specific DNA binding sites, whereas TEI-9647 displayed reduced potency and >10-fold lower sensitivity in this assay system. Limited protease digestion and gel shift clipping assays showed that the two antagonists stabilized individual patterns of VDR conformations. Both antagonists prevented the interaction of the VDR with coactivator proteins, as demonstrated by GST-pull-down and supershift assays; like the natural hormone, however, they were able to induce a dissociation of corepressor proteins. Interestingly, ZK159222 demonstrated functional antagonism in reporter gene assays both in HeLa and MCF-7 cells, whereas TEI-9647 functioned as a less sensitive antagonist only in MCF-7 cells. In conclusion, the two 1alpha,25(OH)(2)D(3) analogs act in part via different molecular mechanisms, which allows us to speculate that ZK159222 is a more complete antagonist and TEI-9647 a more selective antagonist.

Bafilomycin A(1) inhibits rhinovirus infection in human airway epithelium: effects on endosome and ICAM-1.

To examine the effects of bafilomycin A(1), a blocker of vacuolar H(+)-ATPase, on rhinovirus (RV) infection in the airway epithelium, primary cultures of human tracheal epithelial cells were infected with RV14. Viral infection was confirmed by showing that viral RNA in the infected cells and the viral titers in the supernatants of infected cells increased with time. RV14 infection upregulated the production of cytokines and mRNA of intercellular adhesion molecule (ICAM)-1 in epithelial cells. Bafilomycin A(1) reduced the viral titers of RV14 and inhibited the production of cytokines and ICAM-1 before and after RV14 infection. Bafilomycin A(1) reduced susceptibility of epithelial cells to RV14 infection. RV14 increased activated nuclear factor-kappaB in the cells, and bafilomycin A(1) reduced the activated nuclear factor-kappaB. Bafilomycin A(1) decreased the number of acidic endosomes in the epithelial cells. These results suggest that bafilomycin A(1) may inhibit infection by RV14 by not only blocking RV RNA entry into the endosomes but also reducing ICAM-1 expression in the epithelial cells. Bafilomycin A(1) may therefore modulate airway inflammation after RV infection.

Acid exposure stimulates the adherence of Streptococcus pneumoniae to cultured human airway epithelial cells: effects on platelet-activating factor receptor expression.

To examine the effects of acid exposure on the adherence of Streptococcus pneumoniae to cultured human tracheal epithelial cells, cells were exposed to acid at various pH levels, and various concentrations of S. pneumoniae were added to the culture medium. The number of S. pneumoniae adhering to cultured human tracheal epithelial cells increased after acid exposure. Y-24180, a specific inhibitor of the receptor for the platelet-activating factor (PAF) and PAF itself decreased the number of S. pneumoniae adhering to cultured human tracheal epithelial cells after acid exposure. Acid exposure increased the activation of transcription factor nuclear factor (NF)-kappa B and the expression of protein and messenger RNA (mRNA) of the PAF receptor. The pyrrolidine derivative of dithiocarbamate (PDTC), an inhibitor of NF-kappa B, also decreased the number of S. pneumoniae adhering to the cultured human tracheal epithelial cells after acid exposure. Acid exposure increased the content of interleukin (IL)-1 alpha and IL-1 beta in the culture supernatants, but monoclonal antibodies to IL-1 alpha and IL-1 beta failed to inhibit the increased number of S. pneumoniae adhering to cultured human tracheal epithelial cells after acid exposure. These findings suggest that acid exposure stimulates the adherence of S. pneumoniae to the airway epithelial cells via increases in PAF receptors. Increases in PAF receptor expression may be, in part, mediated via activation of transcription factors and subsequent PAF receptor mRNA expression by acid exposure. Increased adherence of S. pneumoniae may be one of the reasons why pneumonia develops after gastric juice aspiration.

A case of partial carnitine palmitoyltransferase deficiency in a patient undergoing chronic hemodialysis.

A 71-year-old male undergoing hemodialysis for chronic renal failure presented with proximal muscle weakness. He had normal levels of serum creatine phosphokinase. The results of nerve conduction velocity studies and a needle-exploration electromyogram were normal. Ultrasonography revealed adenomatous enlargement of the parathyroid glands, and he had marked elevation of the serum parathormone level. The level of serum free carnitine before hemodialysis was significantly lower than normal, while the acyl/free ratio was high. However, the muscle carnitine content was within the normal range. Interestingly, partial inactivation of carnitine palmitoyltransferase activity in the muscle was observed in association with the elevation of the serum parathormone level. Uremic myopathy in this case may be caused not only by abnormal carnitine metabolism but could also be attributable to the partial carnitine palmitoyltransferase deficiency associated with secondary hyperparathyroidism.

Relation between exhaled carbon monoxide levels and clinical severity of asthma.

Carbon monoxide (CO) can be detected in exhaled air and is increased in asthmatic patients not treated with corticosteroids. However, it is uncertain whether exhaled CO is related to severity of asthma. To study whether exhaled CO is related to severity of asthma in clinical courses, exhaled CO concentrations were measured on a CO monitor by vital capacity manoeuvre in 20 mild asthmatics treated with inhaled beta2-agonists alone, 20 moderate asthmatics treated with inhaled corticosteroids, and 15 stable asthmatics treated with high dose inhaled corticosteroids and oral corticosteroids once a month over 1 years. Exhaled CO concentrations were also measured in 16 unstable severe asthmatics who visited the hospital every 7 or 14 days for treatment with high dose inhaled corticosteroids and oral corticosteroids. The mean values of exhaled CO in severe asthma over 1 year were 6.7 +/- 9.5 p.p.m. (n = 31, mean +/- SD) and significantly higher than those of non-smoking control subjects (1.2 +/- 0.9 p.p.m., n = 20, P < 0.01). Exhaled CO concentrations in unstable severe asthmatics were significantly higher than those in stable severe asthmatics. However, exhaled CO concentrations in mild and moderate asthmatics did not differ significantly from those in non-smoking control subjects (P > 0.20). There was a significant relationship between the exhaled CO concentrations and forced expiratory volume in one second in all asthmatic patients. These findings suggest that exhaled CO concentrations may relate to the severity of asthma and measurements of exhaled CO concentrations may be a useful means of monitoring airway inflammation in asthma.

[Propofol pharmacokinetics in a patient with TSH producing pituitary adenoma].

We investigated propofol pharmacokinetics in a patient with secondary hyperthyroidism caused by thyroid stimulating hormone (TSH) producing pituitary adenoma. Laboratory data indicated thyrotoxic state with elevated TSH, FT3 and FT4 levels. General anesthesia was maintained with a doubled propofol infusion rate (8-10 mg.kg-1.hr-1) compared to our standard procedure. During 370 min of infusion, propofol concentrations in arterial blood were kept within optimal ranges (2-4 micrograms.ml-1). Although the clearance of propofol was high (2.8 l.min-1) because of the thyrotoxic state, the patient showed delayed recovery from anesthesia. The half-life of blood propofol after the termination of infusion exceeded 30 minutes (normal: 10-15 minutes). We conclude that the delayed recovery was due to the accumulation of propofol in the adipose tissue during long-term infusion in spite of the increased propofol clearance.

Malignant pleural mesothelioma produces functional granulocyte-colony stimulating factor.

We report a patient with diffuse malignant pleural mesothelioma showing marked elevation of neutrophils. The level of serum granulocyte-colony stimulating factor (G-CSF) was elevated (138 pg/mL; normal range, < 20 pg/mL). The patient died 6 weeks after disease progression had been noted, and immunohistochemistry using a specific monoclonal antibody against recombinant G-CSF at autopsy demonstrated that the malignant mesothelioma cells actually produced G-CSF. Only three cases of malignant pleural mesothelioma, including the current patient, have been reported to produce G-CSF. We demonstrated an elevated serum level of G-CSF and G-CSF-bearing tumor cells by immunochemistry.

Systematic studies on synthesis, structural elucidation, and biological evaluation of A-ring diastereomers of 2-methyl-1alpha,25-dihydroxyvitamin D(3) and 20-epi-2-methyl-1alpha,25-dihydroxyvitamin D(3).

All possible A-ring diastereomers of 2-methyl-1alpha,25-dihydroxyvitamin D(3) (2) and 20-epi-2-methyl-1alpha,25-dihydroxyvitamin D(3) (3) were synthesized by palladium-catalyzed coupling reaction of A-ring 'enyne' synthons with CD-ring portions. The A-ring synthons were rationally synthesized via a novel and practical route, starting with methyl (R)-(+)- and (S)-(-)-3-hydroxy-2-methyl-propionate, in good yields. X-ray crystallographic analysis of 2alpha-methyl-1alpha,25-dihydroxyvitamin D(3) (2b) and conformational analysis of the A-ring of 2alpha-methyl-(2b) and 2beta-methyl-1alpha,25-dihydroxyvitamin D(3) (2f) were carried out, and the results are described. All A-ring diastereomers (2 and 3), thus synthesized, were biologically evaluated both in vitro and in vivo. The biologic potency was highly dependent on the stereochemistry of the A-ring substituents. In particular, 2b showed 4-fold higher vitamin D receptor [VDR] binding activity than the natural hormone, and its 20-epimer (3b) exhibited exceptionally high activity, 12-fold more potent in VDR binding, 7-fold in calcium mobilization, and 590-fold in induction of human promyelocytic leukemia (HL-60) cell differentiation as compared with the natural hormone. Further, the 20-epi-2beta-Me-1beta, 3alpha(OH)(2) isomer (3g) had significant biologic potencies compared to the natural hormone despite having 1beta-OH configuration. The transcriptional activities on human osteocalcin gene promoter, including VDRE in transfected mammalian cells, were also evaluated. Finally, there was a clear contrast between the effects of the 2-methyl group on the HL-60 cell differentiation- and apoptosis-inducing activities of 2 and 3.

Metabolism of 1alpha,25-dihydroxyvitamin D(3) in human promyelocytic leukemia (HL-60) cells: in vitro biological activities of the natural metabolites of 1alpha,25-dihydroxyvitamin D(3) produced in HL-60 cells.

The secosteroid hormone, 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)], induces differentiation of the human promyelocytic leukemia (HL-60) cells into monocytes/macrophages. At present, the metabolic pathways of 1alpha,25(OH)(2)D(3) and the biologic activity of its various natural intermediary metabolites in HL-60 cells are not fully understood. 1alpha,25(OH)(2)D(3) is metabolized in its target tissues via modifications of both the side chain and the A-ring. The C-24 oxidation pathway, the main side chain modification pathway initiated by hydroxylation at C-24 leads to the formation of the end product, calcitroic acid. The C-23 and C-26 oxidation pathways, the minor side chain modification pathways initiated by hydroxylations at C-23 and C-26 respectively together lead to the formation of the end product, 1alpha,25(OH)(2)D(3)-lactone. The C-3 epimerization pathway, the newly discovered A-ring modification pathway is initiated by epimerization of the hydroxyl group at C-3 to form 1alpha,25-dihydroxy-3-epi-vitamin-D(3). We performed the present study first to examine in detail the metabolism of 1alpha,25(OH)(2)D(3) in HL-60 cells and then to assess the ability of the various natural intermediary metabolites of 1alpha,25(OH)(2)D(3) in inducing differentiation and in inhibiting clonal growth of HL-60 cells. We incubated HL-60 cells with [1beta-(3)H] 1alpha,25(OH)(2)D(3) and demonstrated that these cells metabolize 1alpha,25(OH)(2)D(3) mainly via the C-24 oxidation pathway and to a lesser extent via the C-23 oxidation pathway, but not via the C-3-epimerization pathway. Three of the natural intermediary metabolites of 1alpha,25(OH)(2)D(3) derived via the C-24 oxidation pathway namely, 1alpha,24(R),25-trihydroxyvitamin D(3), 1alpha,25-dihydroxy-24-oxovitamin D(3) and 1alpha,23(S),25-trihydroxy-24-oxovitamin D(3) [1alpha,23(S),25(OH)(3)-24-oxo-D(3)] were almost as potent as 1alpha,25(OH)(2)D(3) in terms of their ability to differentiate HL-60 cells into monocytes/macrophages. We then selected 1alpha,23(S),25(OH)(3)-24-oxo-D(3) which has the least calcemic activity among all the three aforementioned natural intermediary metabolites of 1alpha,25(OH)(2)D(3) to examine further its effects on these cells. Our results indicated that 1alpha,23(S),25(OH)(3)-24-oxo-D(3) was also equipotent to its parent in inhibiting clonal growth of HL-60 cells and in inducing expression of CD11b protein. In summary, we report that 1alpha,25(OH)(2)D(3) is metabolized in HL-60 cells into several intermediary metabolites derived via both the C-24 and C-23 oxidation pathways but not via the C-3 epimerization pathway. Some of the intermediary metabolites derived via the C-24 oxidation pathway are found to be almost equipotent to 1alpha,25(OH)(2)D(3) in modulating growth and differentiation of HL-60 cells. In a previous study, the same metabolites when compared to 1alpha,25(OH)(2)D(3) were found to be less calcemic. Thus, the findings of our study suggest that some of the natural metabolites of 1alpha,25(OH)(2)D(3) may be responsible for the final expression of the noncalcemic actions that are presently being attributed to their parent, 1alpha,25(OH)(2)D(3).

Antagonistic Actions in Vivo of (23S)-25-Dehydro-1alpha-Hydroxyvitamin D(3-)26,23-Lactone on Calcium Metabolism Induced by 1alpha,25-Dihydroxyvitamin D(3).

The vitamin D analog, (23S)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9647), is an antagonist of the 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)] nuclear receptor (VDR)-mediated differentiation of human leukemia (HL-60) cells. To clarify whether TEI-9647 could function as an antagonist of 1alpha,25(OH)(2)D(3) in vivo, we investigated in vitamin D-deficient (-D) rats the effects of single doses of TEI-9647 on several parameters of calcium metabolism modulated by 1alpha,25(OH)(2)D(3). TEI-9647 (50 microgram/kg iv) acting alone slightly, but significantly, stimulated intestinal calcium transport (ICA) and bone calcium mobilization (BCM) only at 8 h, but not at 24 h. In contrast, TEI-9647 dose-dependently inhibited ICA and BCM stimulated by an iv dose of 0.25 microgram/kg 1alpha,25(OH)(2)D(3) after 24 h, but not after 8 h. With respect to serum PTH levels, the administration of either TEI-9647, 50 microgram/kg, or 1alpha,25(OH)(2)D(3), 0.25 microgram/kg, began to decrease the circulating levels by 4 h, which reached a nadir 24 h after administration. But, when TEI-9647 and 1alpha,25(OH)(2)D(3) were simultaneously administered to -D rats, the TEI-9647 dose-dependently reversed the inhibition of PTH secretion caused by 1alpha,25(OH)(2)D(3), 0.25 microgram/kg, at 8 and 24 h after the treatment. In separate experiments, the daily iv administration of 20 microgram/kg of TEI-9647 alone to +D rats for 2 weeks resulted in no significant changes in the prevailing serum Ca(2+) concentration. But doses of 1-20 microgram/kg of TEI-9647 in combination with 0.5 microgram/kg of 1alpha,25(OH)(2)D(3), for 2 weeks, dose-dependently and significantly suppressed the serum calcium concentration increase caused by the 1alpha,25(OH)(2)D(3). Collectively, these results show that TEI-9647 acting alone displays in vivo weak agonistic actions, but when administered in combination with 1alpha,25(OH)(2)D(3), is a potent antagonist of three genomic-mediated calcium metabolism parameters. We conclude that TEI-9647 can also function as an antagonist of 1alpha,25(OH)(2)D(3) in vivo in the rat.

Dietary sugar beet fiber ameliorates diarrhea as an acute gamma-radiation injury in rats.

Gamma radiation induces diarrhea as an acute injury. We have studied whether ingestion of sugar beet fiber influences radiation-induced diarrhea. Abdominal irradiation with gamma rays induced diarrhea in male Wistar/ST rats from 2 to 7 days after a single sublethal dose. The body weight of the irradiated rats was decreased temporarily at 4 days after irradiation regardless of the ingestion of sugar beet fiber. At day 8, it returned to almost the same level as that of unirradiated rats. A change in daily food intake resulted in a pattern similar to that for body weight. Dietary sugar beet fiber had little significant effect on the changes in body weight and daily food intake, and its ingestion significantly decreased gamma-ray-induced diarrhea. Changes in biochemical and histological parameters in intestinal mucosa (small intestine, cecum and colon) were not greatly influenced by the ingestion of sugar beet fiber through the periods of diarrhea. It was concluded that dietary sugar beet fiber ameliorated the diarrhea induced by abdominal irradiation. We suggest that the inhibitory effect of the ingestion of sugar beet fiber is due to its effects on the luminal environment, such as support for bacterial function in the luminal contents in the colon of animals that ingest sugar beet fiber.

Antagonistic action of novel 1alpha,25-dihydroxyvitamin D(3)-26, 23-lactone analogs on 25-hydroxyvitamin-D(3)-24-hydroxylase gene expression induced by 1alpha,25-dihydroxy-vitamin D(3) in human promyelocytic leukemia (HL-60) cells.

We have demonstrated that 1alpha,25-dihydroxyvitamin D(3)-26, 23-lactone analogs, (23S)- and (23R)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9647, TEI-9648, respectively), inhibit HL-60 cell differentiation induced by 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)], but not differentiation caused by all-trans retinoic acid (D. Miura et al., 1999, J. Biol. Chem. 274, 16392). To assess whether the antagonistic actions of TEI-9647 and TEI-9648 in HL-60 cells are related to 1alpha,25(OH)(2)D(3) breakdown, we investigated their effects on catabolism of 1alpha,25(OH)(2)D(3). In HL-60 cells, the C-24 but not the C-23 side-chain oxidation pathway of 1alpha,25(OH)(2)D(3) has been reported. Here we demonstrate that 1alpha,25(OH)(2)D(3) was metabolized both to 24,25,26,27-tetranor-1alpha,23-(OH)(2)D(3) and 1alpha,25(OH)(2)D(3)-26,23-lactone; thus HL-60 cells constitutively possess both the 24- and the 23-hydroxylases. Metabolism of 1alpha, 25(OH)(2)D(3) was strongly suppressed by 10(-7) M TEI-9647 or 10(-6) M TEI-9648. 1alpha,25(OH)(2)D(3) alone slightly induced 24-hydroxylase gene expression by 8 h with full enhancement by 24-48 h; this induction was inhibited by 10(-6) M TEI-9647 and 10(-6) M TEI-9648 (86.2 and 31.9%, respectively) 24 h after treatment. However, analogs of TEI-9647 and TEI-9648 without the 25-dehydro functionality induced 24-hydroxylase gene expression. These results indicate that TEI-9647 and TEI-9648 clearly mediate their stereoselective antagonistic actions independent of their actions to block the catabolism of 1alpha,25(OH)(2)D(3). Therefore, TEI-9647 and TEI-9648 appear to be the first antagonists specific for the nuclear 1alpha,25(OH)(2)D(3) receptor-mediated genomic actions of 1alpha,25(OH)(2)D(3) in HL-60 cells.

Dietary sugar beet fiber prevents the increase in aberrant crypt foci induced by gamma-irradiation in the colorectum of rats treated with an immunosuppressant.

We demonstrated recently that gamma-irradiation can induce aberrant crypt foci (ACF) in the rat colorectum. The aim of this study was to evaluate the effect of dietary sugar beet fiber (SBF) on the distribution of the CD8(+) intraepithelial lymphocyte (IEL) in the colorectum and on the number of gamma-irradiation-induced ACF of rats administered anti-asialo GM1 (alpha AGM1) as an immunosuppressant. Wistar/ST rats fed a fiber-free diet or the diet supplemented with SBF (100 g/kg diet) were administrated alpha AGM1 or normal rabbit serum as a control during the initiation period with gamma-irradiation. At 5 and 9 wk after the first irradiation, ACF and total aberrant crypts (AC) per area in the colorectum were counted. The numbers of ACF (P = 0.0010) and AC (P = 0.0635) per unit area were lower in the SBF-fed group than in the rats fed the fiber-free diet. alpha AGM1 administration significantly raised the number of ACF (P = 0.0001) and AC (P = 0.0006) per area in the colorectum. Moreover, alpha AGM1 administration during the initiation period reduced the number of CD8(+) IEL per 100 cells in the epithelial layer (P = 0.0001) of the colon. These results demonstrate that reduction of the number of CD8(+) IEL per 100 cells in the epithelial layer as a result of alpha AGM1 administration promotes the formation of irradiation-induced ACF in the colorectum. The number of CD8(+) IEL per 100 cells in epithelial layer was lower in the group fed the fiber-free diet than in the SBF-fed group (P = 0.0522). These results indicated that the ingestion of dietary SBF suppressed gamma-irradiation-induced ACF formation through the immune surveillance in the colorectal mucosa.

Correlations between bone mineral density and circulating bone metabolic markers in diabetic patients.

Diabetic osteopenia, a known chronic complication of diabetes, has been demonstrated with alterations in the calcium-vitamin D endocrine system. In order to investigate the relationship between the decrease of bone density and the altered mineral metabolism in non-insulin-dependent diabetes mellitus (NIDDM), 104 male clinical-proven NIDDM patients were studied. All patients were examined on metacarpal bone mineral density (m-BMD) by means of computed X-ray densitometry (CXD) methods. The values of the Z-score of m-BMD were significantly lower than those of age-matched controls (P<0.01). There was a positive correlation between m-BMD and serum calcium levels (P<0.01), but a negative correlation was conversely observed between m-BMD and serum intact parathyroid hormone (PTH) (P<0.01), indicating that the negative calcium balance under diabetic conditions could cause the decrease of m-BMD in NIDDM. Interestingly, since a significantly positive correlation was found between circulating levels of calcium and parathyroid hormone-related peptide (PTHrP) (P<0.05) but not PTH, it seems likely that PTHrP plays a more compensatory role on the maintenance of calcium homeostasis than PTH under diabetic conditions. Based on these observations, the CXD method would be useful in measuring the mineral density of cortical bone, and would also be beneficial to investigate underlying pathogenetic mechanism of diabetic osteopenia.

Simultaneous inhibition of renal phospholipase A(2) and glutathione synthesis by manoalide and DL-buthionine sulfoximine induces acute tubular dysfunction in rats.

We have previously demonstrated that gentamicin-induced acute renal failure is mediated by the consumption of renal glutathione (GSH) and accumulation of oxidized phospholipids in tubular epithelial cells as a result of inhibition of phospholipase A(2) (PLA(2)) activity. Based on these results, we tested the hypothesis that the simultaneous inhibition of PLA(2) and GSH synthesis induces acute renal failure similar in characteristics to gentamicin-induced acute renal failure. Male Sprague-Dawley rats kept under standard laboratory conditions were administered 3 mmol/kg of DL-buthionine sulfoximine (BSO; gamma-glutamylcysteine synthetase inhibitor) and 30 microg/kg of manoalide (PLA(2) inhibitor), following which significant elevations in serum creatinine and urinary lysosomal enzyme levels (elevation of N-acetyl-beta-D-glucosaminidase activity) were observed. The renal tissue GSH content was reduced in the group that received both BSO and manoalide as compared with the group that received manoalide alone. The renal tissue GSH content was also reduced in the group that received BSO alone. The renal tissue concentration of 2-thiobarbituric-acid-reactive substances increased rapidly, followed by an increase in renal tissue total phospholipid concentration in the group that received both BSO and manoalide. In contrast, the activity of PLA(2) in renal tissue decreased in the group that received both BSO and manoalide as compared with the groups that received BSO alone or physiological saline. In conclusion, concomitant administration of BSO and manoalide induces renal tubular damage and acute renal failure in rats, similar in characteristics to gentamicin-induced nephrotoxicity, whereas administration of BSO or manoalide alone did not. These results suggest that both inhibition of PLA(2) and GSH depletion are necessary for the induction of acute renal failure.

Effects of dexamethasone on rhinovirus infection in cultured human tracheal epithelial cells.

To examine the effects of glucocorticoid on rhinovirus (RV) infection, primary cultures of human tracheal epithelial cells were infected with either RV2 or RV14. Viral infection was confirmed by demonstrating that viral RNA in infected cells and viral titers of supernatants and lysates from infected cells increased with time. RV14 infection upregulated the expression of mRNA and protein of intercellular adhesion molecule-1 (ICAM-1), the major RV receptor, on epithelial cells, and it increased the production of interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor-alpha in supernatants. Dexamethasone reduced the viral titers of supernatants and cell lysates, viral RNA of infected cells, and susceptibility of RV14 infection in association with inhibition of cytokine production and ICAM-1 induction. In contrast to RV14 infection, dexamethasone did not alter RV2 infection, a minor group of RVs. These results suggest that dexamethasone may inhibit RV14 infection by reducing the surface expression of ICAM-1 in cultured human tracheal epithelial cells. Glucocorticoid may modulate airway inflammation via reducing the production of proinflammatory cytokines and ICAM-1 induced by rhinovirus infection.