Exosomal miR206 Secreted From Growing Muscle Promotes Angiogenic Response in Endothelial Cells

BACKGROUND

Resistance exercise is beneficial in patients with lower extremity arterial disease. Muscle-derived exosomes contain many types of signaling molecules, including microRNAs (miRNAs). Here, we tested the hypothesis that exosomal miRNAs secreted by growing muscles promote an angiogenic response in endothelial cells (ECs).Methods and Results: Skeletal muscle-specific conditional Akt1 transgenic (Akt1-TG) mice, in which skeletal muscle growth can be induced were used as a model of resistance training. Remarkable skeletal muscle growth was observed in mice 2 weeks after gene activation. The protein amount in exosomes secreted by growing muscles did not differ between Akt1-TG and control mice. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway frequency analysis of 4,665 target genes, identified using an miRNA array miRNAs, revealed a significant increase in Akt and its downstream signaling pathway genes. Among the upregulated miRNAs, miR1, miR133, and miR206 were significantly upregulated in the serum of Akt1-TG mice. miR206 was also increased in insulin-like growth factor (IGF)-1-stimulated hypertrophied myotubes. Exogenous supplementation of exosomal miR206 to human umbilical vein ECs promoted angiogenesis, as assessed using the spheroid assay, and increased the expression of angiogenesis-related transcripts.

CONCLUSIONS

Exosomal miR206 is upregulated in the blood of Akt1-TG mice and in IGF-stimulated cultured myotubes. Exogenous supplementation of miR206 promoted an angiogenic response in ECs. Our data suggest that miR206 secreted from growing muscles acts on ECs and promotes angiogenesis.

Quantification of pulmonary perfusion using LSIM-CT correlates with pulmonary hemodynamics in patients with CTEPD

Background

Lung subtraction iodine mapping (LSIM)-CT is a clinically useful technique that can visualize pulmonary mal-perfusion in patients with chronic thromboembolic pulmonary disease (CTEPD). However, little is known about the associations of LSIM images with hemodynamic parameters of patients with CTEPD. This study investigates a parameter of LSIM images associated with mean pulmonary arterial pressure (mPAP) and validates the association between pulmonary vascular resistance, right atrial pressure, cardiac index, and exercise capacity in patients with CTEPD.

Methods

This single-center, prospective, observational study involved 30 patients diagnosed with CTEPD using lung perfusion scintigraphy. To examine the correlation of decreased pulmonary perfusion area (DPA) with mPAP, areas with 0-10, 0-15, 0-20, and 0-30 HU in lung subtraction images were adopted in statistical analysis. The DPA to total lung volume ratio (DPA ratio, %) was calculated as the ratio of each DPA volume to the total lung volume. To assess the correlation between DPA ratios of 0-10, 0-15, 0-20, and 0-30 HU and mPAP, Spearman's rank correlation coefficient was used.

Results

The DPA ratio of 0-10 HU had the most preferable correlation with mPAP than DPA ratios of 0-15, 0-20, and 0-30 HU (ρ = 0.440, P = 0.015). The DPA ratio of 0-10 HU significantly correlates with pulmonary vascular resistance (ρ = 0.445, P = 0.015). The receiver operating characteristic curve analysis indicated that the best cutoff value of the DPA ratio of 0-10 HU for the prediction of an mPAP of ≥30 mmHg was 8.5% (AUC, 0.773; 95% CI, 0.572-0.974; sensitivity, 83.3%; specificity, 75.0%). Multivariate linear regression analysis, which was adjusted for the main pulmonary arterial to ascending aortic diameter ratio and right ventricular to left ventricular diameter ratio, indicated that the DPA ratio of 0-10 HU was independently and significantly associated with mPAP (B = 89.7; 95% CI, 46.3-133.1, P < 0.001).

Conclusion

The DPA ratio calculated using LSIM-CT is possibly useful for estimating the hemodynamic status in patients with CTEPD.

The E/e' ratio on echocardiography as an independent predictor of the improvement of left ventricular contraction in patients with heart failure with reduced ejection fraction

OBJECTIVE

Clinical feature of heart failure with improved ejection fraction (HFimpEF) remains to be fully elucidated. The present study investigated the association of clinical and echocardiographic parameters with the subsequent improvement of left ventricular ejection fraction (LVEF) in heart failure with reduced ejection fraction (HFrEF).

METHODS

From outpatients with a history of hospitalized for heart failure, 128 subjects diagnosed as HFrEF (LVEF <40%) on heart failure hospitalization were enrolled and longitudinally surveyed. During follow-up periods more than 1 year, 58 and 42 patients were identified as HFimpEF (improved LVEF to ≥40% and its increase of ≥10 points) and persistent HFrEF, respectively.

RESULTS

There was no difference in age or sex between the two groups with HFimpEF and persistent HFrEF. The rate of ischemic heart disease was lower and that of tachyarrhythmia was higher in the HFimpEF group than in the persistent HFrEF group. At baseline (i.e., on heart failure hospitalization), LVEF did not differ between the two groups, but left ventricular systolic and diastolic diameters were already smaller and the ratio of early diastolic transmitral velocity to early diastolic tissue velocity (E/e') was lower in the HFimpEF group. A multiple logistic regression analysis revealed that lower baseline E/e' was a significant determinant of HFimpEF, independently of confounding factors such as ischemic heart disease, tachyarrhythmia, and baseline left ventricular dimension.

CONCLUSION

Our findings indicate that the lower ratio of E/e' in the acute phase of heart failure onset is an independent predictor of the subsequent improvement of LVEF in HFrEF patients.

Angioscopic Ulcerated Plaques in the Femoropopliteal Artery Associated with Impaired Infrapopliteal Runoff

PURPOSE

To determine the correlation between upstream atherosclerosis in the femoropopliteal arteries, assessed using angioscopy, and impaired infrapopliteal runoff.

MATERIALS AND METHODS

Thirty-one patients with peripheral arterial disease who underwent endovascular therapy and angioscopy were prospectively included. Yellow plaque color scores were semiquantitatively determined as 0, 1, 2, or 3. Irregular plaques with rough surfaces, similar to gastric ulcers, were defined as ulcerated plaques (UPs). Angioscopic data were correlated with angiographic runoff scores (ARS).

RESULTS

UPs were detected in 74.2% of enrolled diseased legs using angioscopy. Mural thrombi were more commonly observed in the femoropopliteal artery in patients with UPs than in those without UPs (91.3% vs 37.5%, respectively; P = .006) and were frequently found on the UPs (21/23 patients with UPs). Univariate and multivariate linear regression analyses revealed that the presence of UPs was positively and independently associated with a poor ARS and that oral anticoagulant use was independently associated with a preferable ARS (standardized β = 0.462, P = .004 and standardized β = -0.411, P = .009, respectively, in the multivariate analysis).

CONCLUSIONS

UPs, associated with mural thrombi and diagnosed by angioscopic examination, were demonstrated to be one of the factors associated with poor infrapopliteal runoff.

Estimation of the Long-Term Dimensional Stability Performance of Hydrocarbon Blown Rigid Polyurethane Foams for Insulation—A Novel Approach

For years, HCs with zero ODP and low GWP have been used as alternative B.A. (blowing agents) in the appliance industries. The improvement of insulation performance and lowering costs are significant factors in the development of R-PU (rigid polyurethane) foams especially blown with HCs. The development of R-PU foam with a lower density for cost effectiveness is progressing at present. Positive experiences as to the long-term dimensional stability of pentane blown R-PU foam accelerated this movement. The most important factor in the development of R-PU foam with a lower density is long-term dimensional stability. In this report, we propose a novel long-term dimensional stability test and its appropriateness is discussed. The influence of formulation and the boiling point (B.P.) of B.A. on long-term dimensional stability have also been studied. The use of a blowing agent mixture of cyclopentane and iso- or n-pentane with a lower B.P. allowed the achievement of density savings. The understanding of the relation between the formulation and long-term dimensional stability is an important issue for the development of R-PU foam.

Stereopsis-processing regions in the human parieto-occipital cortex

We performed fMRI on the human parieto-occipital cortex in order to identify the neural processing regions of stereopsis. Visual stimulation for stereopsis was performed with a random-dot stereogram displayed in the image guides of a new binocular visual stimulation device that we developed. Interestingly, regions from the dorsal portion of the occipital lobe to the superior parietal lobule were activated by binocular disparity, while the inferior parietal lobule was not activated. Moreover, these regions were shown as dominant in the right hemisphere. Functional brain mapping revealed that the processing regions of stereopsis were dorsally located in parieto-occipital cortex, and that the superior parietal lobule is an important region for neural processing of human stereopsis.

Toxic shock syndrome after suction lipectomy

We present a case of toxic shock syndrome with necrotizing fasciitis after suction lipectomy. The patient underwent aesthetic suction lipectomy of the abdomen, buttocks, and thighs during an office procedure by a cosmetic surgeon. On postoperative day 2, the patient was referred to the emergency department of our hospital because of pain. On admission, the patient was in toxic shock. She required intensive medical treatment for about 1 month, along with psychiatric help to adapt after the illness. Although toxic shock syndrome is a rare postoperative complication, every plastic surgeon should be acquainted with it. A combination of early recognition, diagnosis, and aggressive supportive therapy is the only successful treatment.

[Diagnosis of magnetic resonance imaging (MRI) for blowout fracture--three advantages of MRI]

INTRODUCTION

Magnetic resonance imaging (MRI) gives a much more detailed picture of the soft tissue than computerized tomography (CT). In blowout fracture cases, it is very easy to observe the incarcerated orbital tissue.

SUBJECTS

We performed MRI in 19 blowout fracture cases.

RESULTS

After evaluating the images, we found three advantages of MRI. The first is that even small herniation of the orbital contents can easily be detected because the orbital fatty tissue contrasts well around the other tissues in MRI. The second is that the incarcerated tissues can be clearly differentiated because a clear contrast between the orbital fatty tissue and the extraocular muscle can be seen in MRI. The third is that the running images of the incarcerated muscle belly can be observed because any necessary directional slies can be taken in MRI.

CONCLUSION

These advantages are very important in the diagnosis of blowout fractures. MRI should be employed in blowout fracture cases in addition to CT.

Class specific influence of dietary Spirulina platensis on antibody production in mice

In the present study, we investigated antibody productions of IgA and other classes, such as IgE and IgG1, in mice as possible evidence of the protective effects of Spirulina toward food allergy and microbial infection. An increase of IgE antibody level in the serum was observed in the mice that were orally immunized with crude shrimp extract as an antigen (Ag group). The antibody level, however, was not further enhanced by treatment with Spirulina extract (SpHW). IgG1 antibody, on the other hand, which was increased by antigen administration, was further enhanced by Spirulina extract. It was noted that the IgA antibody level in the intestinal contents was significantly enhanced by treatment with Spirulina extract concurrently ingested with shrimp antigen, in comparison with that of the Ag group treated with shrimp antigen alone. An enhancement of IgA antibody production by Spirulina extract was also observed in culture supernatant of lymphoid cells, especially in the spleen and mesenteric lymph node from mice treated with Spirulina extract for 4 weeks before antigen stimulation. These results suggest that Spirulina may at least neither induce nor enhance allergic reaction such as food allergy dependent on an IgE antibody, and that when ingested both concurrently with antigen and before antigen stimulation, it may significantly enhance the IgA antibody level to protect against allergic reaction.

Changes in immunological parameters after combination adjuvant therapy with intravenous DTIC, ACNU, and VCR, and local injection of IFN-beta (DAV + IFN-beta therapy) into malignant melanoma

Combination adjuvant therapy with intravenous dimethyl triazeno imidazole carboxamide (DTIC), 1-[4-amino-2-methyl-5-pyrimidinyl]-methyl-3-[2-chloroethyl]-3-nitrosoure a hydrochloride (ACNU) and vincristine (VCR) and local injection of interferon-beta (IFN-beta) (DAV + IFN-beta therapy) has been widely applied to treat malignant melanoma, and its therapeutic effect is accepted in Japan. Natural killer (NK) activity, CD4+ and CD8+ T cell counts, CD4/CD8 ratio, and white blood cell counts were analyzed before and after DAV + IFN-beta therapy in order to validate its efficacy. After DAV + IFN-beta therapy, the CD4/CD8 ratio was elevated; however, numbers of both CD4+ and CD8+ T cells and NK activity were consecutively depressed. Peripheral lymphocytes were also decreased, possibly by myelosuppression due to the DAV therapy. The posttreatment suppression of NK activity appeared in spite of the administration of IFN-beta. It is suggested that a more effective adjuvant immunomodulator should be introduced to improve the therapeutic effect of the combination adjuvant chemotherapy in malignant melanoma.

Role of C5a-ase in group B streptococcal resistance to opsonophagocytic killing

Type III group B streptococci (GBS) can be subdivided into three subtypes, RDP III-1, III-2, and III-3, on the basis of numerical analysis of HindIII restriction endonuclease digestion patterns (HindIII RDP) with their chromosomal DNAs. In the present study, the effect of C5a on opsonophagocytic killing of a representative strain from each RDP type was investigated by using a novel optical method for determining opsonophagocytic killing, and the effect of C5a-ase treatment of C5a on opsonophagocytic killing was also investigated. Pre-stimulation of polymorphonuclear leukocytes (PMNs) with C5a significantly increased opsonophagocytic killing of all three strains. The increase in killing was abolished by pretreating the C5a with GBS that express C5a-ase, a treatment that also destroyed the chemoattractant activity of the C5a. The kinetics of killing of the RDP III-2 strain differed from those of the other two strains. The survival of the RDP III-2 bacteria continued to decline over the entire 60-min incubation of the opsonophagocytic assay when PMNs were prestimulated with C5a or with C5a that had been inactivated with GBS C5a-ase (dC5a). In contrast, killing of the RDP III-1 and III-3 strains almost ceased after 20 or 60 min when PMNs were prestimulated with dC5a or C5a, respectively. A difference in bacterial killing between the III-2 strain and the III-1 and III-3 strains therefore became increasingly apparent with prolonged incubation time. The percentage of bacteria surviving in the extracellular fluid was approximately the same as the percentages of bacteria surviving in both intracellular and extracellular locations when PMNs were prestimulated with either C5a or dC5a. These data imply that the majority of bacterial killing occurred following phagocytosis and suggest that the enhanced killing of GBS following prestimulation of PMNs with C5a resulted from increased ingestion of the bacteria.

[Localization and response characteristics of thalamic corneal units in the cat]

Units in the thalamus responsive to mechanical stimulation of the cornea (thalamic corneal units) were studied in urethane-chloralose anesthetized cats. Four different classes of corneal units were found in the nucleus ventralis posteromedialis (VPM) and intralaminar nuclei. They corresponded to 4 different classes of corneal units in the trigeminal subnucleus caudalis and adjacent bulbar lateral reticular formation reported by Nishida (1987). Low threshold corneal specific (LTCS) units, whose mechanical threshold was well below the pain threshold in patients with cataract, were located in the dorsolateral part of the VPM proper. High threshold corneal specific (HTCS) units and wide dynamic range (WDR) units, whose mechanical threshold was well above the pain threshold of the human cornea, were located in the shell region of caudal VPM. Each class of these three corneal units was incorporated in the somatotopic organization of low threshold mechanoreceptive, nociceptive specific, or WDR units having a cutaneous receptive field in the contralateral trigeminal nerve territory. Units having receptive fields in the head similar to those of subnucleus reticularis ventralis (SRV) units were found in the intralaminar nuclei. Their corneal mechanical thresholds were much the same as those of HTCS units and WDR units. These results supported the suggestion that both nonpainful sensation and pain can be evoked in the cornea.

Enhancement of antibody production in mice by dietary Spirulina platensis

Mice fed a Spirulina platensis diet showed increased numbers of splenic antibody-producing cells in the primary immune response to sheep red blood cells (SRBC). However, immunoglobulin G (IgG)-antibody production in the secondary immune response was hardly affected. The percentage of phagocytic cells in peritoneal macrophages from the mice fed S. platensis diet, as well as the proliferation of spleen cells by either concanavalin A (Con A) or phytohemagglutinin (PHA) was significantly increased. Addition of a hot-water extract of S. platensis (SHW) to an in vitro culture of spleen cells markedly increased proliferation of these cells, whereas culture of thymus cells was scarcely affected. The Spirulina extract also significantly enhanced interleukin-1 (IL-1) production from peritoneal macrophages. Addition to the in vitro spleen cell culture of SHW as well as the supernatant of macrophages stimulated with SHW resulted in enhancement of antibody production, that is, an increase of the number of PFC. These results suggest that Spirulina enhances the immune response, particularly the primary response, by stimulating macrophage functions, phagocytosis, and IL-1 production.

Detection of interleukin-1 activity in human bladder cancer cell lines

Detection of interleukin (IL)-1 activity was studied in two human bladder cancer cell lines, T24 and EJ1, and one rat bladder carcinoma cell line, 804G. Significantly high proliferation of mouse thymocytes in the assay of IL-1 activity was observed in the conditioned medium (CM) of T24 cells, indicating that the cells released IL-1-like activity. Enzyme-linked immunosorbent assay (ELISA) and Northern blot analysis showed the presence of both IL-1 alpha and IL-1 beta in the CM of T24 cells and expression of mRNAs of both cytokines in the cells. Interleukin-1 activity in EJ1 cells, which produced a little activity, was induced by E. coli lipopolysaccharide (LPS) while it was not induced in T24 by either LPS or other test substances. Conditioned medium of T24 increased proliferation of both T24 and EJ1 in cell-growth assay. Further investigation of the mode of action and role of cytokines, especially those from tumor cells themselves, is necessary in relation to BCG or photodynamic therapy.

Myelodysplastic syndrome associated with relapsing polychondritis: unusual transformation from refractory anemia to chronic myelomonocytic leukemia

The authors report an unusual case of myelodysplastic syndrome (MDS) associated with relapsing polychondritis (RP), which developed at almost the same time as MDS. The initial diagnosis was MDS, refractory anemia (RA) subtype, according to the FAB classification. Symptoms of RP were apparently controlled by oral administration of prednisolone (PSL), although MDS was not. Within 1 month after the diagnosis, monocytosis and thrombocytopenia without excess of blasts became prominent and transformation from RA to chronic myelomonocytic leukemia (CMML) was recognized. Combination chemotherapy including daunorubicin (DNR) and cytosine arabinoside (ara-c) did not subdue the progressive monocytosis and thrombocytopenia. Finally, the patient died of pulmonary hemorrhage 3 months after the onset of the disease. The prognosis of MDS may be poorly influenced by association with RP.

[Volume measurement of the horizontal extraocular muscles using magnetic resonance imaging]

The volume of the horizontal extraocular muscles of 11 normal adults and three patients with ophthalmoplegia was measured using magnetic resonance imaging (MRI). The MRI examinations were carried out with a Signa Advantage, 1.5 tesla superconductive magnetic system manufactured by General Electric. This method employs the spin echo technique with a 3.0 mm gapless slice, a 350 ms. repetition time, and a 17.0 ms. echo time. The MRI films were projected and magnified on Kent paper using an overhead projector. Then the shapes of the horizontal extraocular muscles were traced. The volume of the muscles was measured as the total weight of Kent papers which were cut out from muscle shapes in all the slices. The average volume of the normal medial and lateral rectus muscles was 690 +/- 87 mm3 and 734 +/- 77 mm3, respectively. Two cases with peripheral nerve palsy showed typical atrophy of the paretic muscles. A case with orbital myositis showed typical hypertrophy of the inflamed muscles. This measurement may prove useful in the analysis and evaluation of extraocular muscles, especially in ophthalmoplegia.

Effects of urinary transferrin and ornithine decarboxylase-inducing fraction on rat bladder carcinogenesis

Using heterotopically transplanted rat urinary bladder (HTB) system, we previously have shown that contact with urine enhanced bladder carcinogenesis initiated by carcinogen. In order to screen urine for promoter substances, several short term in vitro assays were developed and their results were correlated with the in vivo assay results. Chromatographically separated urine fractions were examined for the inability to induce ornithine decarboxylase (ODC), to enhance incorporation of [3H]thymidine in a bladder carcinoma cell line (804G) and to form colonies in soft agar by NRK-49F. Data from the ODC assay and soft agar colony formation correlated well with the results derived from chronic animal studies. Thus then two assays appear useful in further screening urine for promoter substance. Data furthermore indicate that ODC-inducing urine component(s) may play a primary role in the steps following initiation whereas transferrin, a mitogenic urine component, may play a secondary role.

Identification of epidermal growth factor as a component of the rat urinary bladder tumor-enhancing urinary fractions

Using the heterotopically transplanted rat urinary bladder, we have shown that normal rat urine has a potent tumor-enhancing effect on bladder carcinogenesis. In an attempt to isolate tumor-enhancing factor(s), urine was fractionated by Bio-Gel P-100 column chromatography and each eluate fraction was examined for inducibility of ornithine decarboxylase (ODC) in a target rat bladder carcinoma cell line, 804G. We have identified two ODC-inducible peaks, one located in a high molecular weight region designated as Fraction I (Fr. I) and the second in a low molecular weight region designated as Fraction II (Fr. II). Fr. I consisted of two principal elements, transferrin and a component which induced ODC. The present investigation was conducted to characterize the ODC-inducible activity in Fr. I and II. Chromatographic analysis of Fr. I by Sephacryl S-200 and Fr. II by Bio-Gel P-10 chromatography separated several ODC-inducible peaks. However, the major ODC inducibility was due to a high concentration (460 ng/mg Fr. I residue, approximate Mr 54,000, and 580 ng/mg Fr. II residue, approximate Mr 6,100) of epidermal growth factor (EGF) as determined by radioimmunoassay. Aliquots obtained from these peaks competed with mouse EGF for EGF receptors in A431 cells. Preincubation of Fr. I and II with rabbit anti-rat EGF IgG significantly reduced ODC inducibility. Transforming growth factor alpha activity as determined by radioimmunoassay was also demonstrated in both Fr. I (34 ng/mg) and Fr. II (9 ng/mg). The results of the present study together with our previous data indicate that the majority of the ODC-inducing activity in the tumor-enhancing urinary components Fr. I and Fr. II is due to EGF itself and EGF-related growth factors of high molecular weight and that Fr. I also contains transferrin.

Transferrin as a growth factor for rat bladder carcinoma cells in culture

Using the heterotopically transplanted rat urinary bladder system, we previously showed that normal urine has a tumor-enhancing effect on carcinogen-initiated urothelium. In an attempt to isolate a urinary growth-stimulating (tumor-enhancing) factor(s), urine was first fractionated by Bio-Gel P-100 column chromatography, and each fraction was tested for inducibility of ornithine decarboxylase (ODC) and growth-stimulatory activity in a target rat bladder carcinoma cell line, 804G. ODC inducibility was chosen as a marker for tumor-enhancing effect because it is a key characteristic of tumor promoters. There was a single peak demonstrating a strong growth-stimulatory activity as measured by [3H]thymidine incorporation. There were two ODC-inducible peaks, one located at a high molecular weight region and partly overlapped with the growth-stimulatory peak. The other was located at a lower molecular weight region. CM-Sephadex chromatography and subsequent high performance liquid chromatography successfully separated the high molecular weight-ODC activity from the growth-stimulatory activity. The latter component was found to contain transferrin (TF) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunodiffusion with anti-rat TF antibody and was designated as urinary transferrin fraction. The urinary TF fraction and authentic rat TF stimulated growth of several rat bladder carcinoma cells maintained in a serum-free as well as a serum-deficient medium. The response was proportional to the concentration of TF ranging from 0.2 to 5 microgram/ml. Preincubation of the urinary TF fraction or TF with an anti-rat TF significantly reduced their growth-stimulatory effects in 804G cells. The high molecular weight-ODC also stimulated cell growth but to a lesser extent. These results when combined with our previous observations suggest that TF and possibly also ODC-inducible substances may be important urinary components participating in the tumor promotion by urine.

The minimal requirement of circulation for survival of undelayed and delayed flaps in rats

In an attempt to clarify the delay phenomenon, the regional blood flow was measured in 10 undelayed flaps and 65 delayed flaps in rats by the clearance method with the electrolytically generated hydrogen. The ultimate purpose of this study was to establish the minimal requirement of blood flow for flap survival. The dye distance and the survival length were also measured. Blood flow in the flap increased with the delay period. Elongation of the survival length and the dye distance corresponded well to the circulatory enhancement. The present findings support the theory that delay improves blood circulation. The distance from the base to the 0.04-ml flow point was found to be highly correlated with survival length in the delayed groups as well as in the undelayed group. Based on the results, the minimal requirement of circulation for flap survival was assumed to be approximately 0.04 ml/min per gram of tissue whether or not the flap was delayed.

The heterotopically transplanted rat urinary bladder as a model for detection of tumor-promoting urinary growth factor(s)

The heterotopically transplanted rat urinary bladder (HTB) was developed in our laboratory as a model to study the role of urine in urinary bladder carcinogenesis. With this model, normal urine was found to enhance urinary bladder carcinogenesis initiated by N-methyl-N-nitrosourea or N-butyl-N-(4-hydroxybutyl)nitrosamine. Two crude urinary components (Fractions I and II) were obtained by gel filtration chromatography; they stimulated ornithine decarboxylase (ODC) in a test bladder carcinoma cell line 804G, and promoted carcinogenesis in the HTB system. Fraction I was found to stimulate growth of 804G cells in vitro. Preliminary data indicate that Fraction I contains at least one, and possibly two heat-stable ODC-inducible and mitogenic components. Further characterization of these components is in progress. The HTB system has been demonstrated to be useful for other investigations; for example, alpha-difluoromethylornithine, an enzyme-activated irreversible inhibitor of ODC, when instilled repeatedly to the bladder lumen, inhibited tumorigenesis in HTBs.

The influence of phase shift in the light-dark cycle on humoral immune responses of mice to sheep red blood cells and polyvinylpyrrolidone

The influence of a phase shift in the light-dark cycle on humoral immune responses against sheep red blood cells (SRBC), a thymus-dependent antigen, and against polyvinylpyrrolidone (PVP), a thymus-independent antigen, was studied by using 180 BALB/c mice and 150 C3H/HeN mice. Significant suppression of the immune response to SRBC and the number of splenic plaque-forming cells (PFC) and hemagglutination (HA) titers was observed on days 5 and 6 after inversion of the light-dark cycle. On the other hand, the number of splenic PFC and HA titers in the blood against PVP were minimally suppressed by the phase shift in C3H/HeN mice, except for distortion of the rhythmicity. Corticosterone levels in the blood on days 5 and 6 after inversion were higher than those under a normal lighting regimen. The appearance of the high corticosterone level in the blood after the inversion almost concurred with the suppression of the immune response to SRBC. A decrease of the proportion of splenic T cells was also observed on day 6 after the inversion. These results show that a phase shift in the light-dark cycle provokes suppression of the immune response to SRBC, possibly through an increase of secretion of corticosterone after light-dark inversion, which induces a decrease of the proportion of T lymphocytes in the spleen.

The influence of phase shift in the light-dark cycle on humoral immune responses of mice to sheep red blood cells and polyvinylpyrrolidone

The influence of a phase shift in the light-dark cycle on humoral immune responses against sheep red blood cells (SRBC), a thymus-dependent antigen, and against polyvinylpyrrolidone (PVP), a thymus-independent antigen, was studied by using 180 BALB/c mice and 150 C3H/HeN mice. Significant suppression of the immune response to SRBC and the number of splenic plaque-forming cells (PFC) and hemagglutination (HA) titers was observed on days 5 and 6 after inversion of the light-dark cycle. On the other hand, the number of splenic PFC and HA titers in the blood against PVP were minimally suppressed by the phase shift in C3H/HeN mice, except for distortion of the rhythmicity. Corticosterone levels in the blood on days 5 and 6 after inversion were higher than those under a normal lighting regimen. The appearance of the high corticosterone level in the blood after the inversion almost concurred with the suppression of the immune response to SRBC. A decrease of the proportion of splenic T cells was also observed on day 6 after the inversion. These results show that a phase shift in the light-dark cycle provokes suppression of the immune response to SRBC, possibly through an increase of secretion of corticosterone after light-dark inversion, which induces a decrease of the proportion of T lymphocytes in the spleen.

Different effects of prostaglandin E1, E2 and D2 on pancreatic somatostatin release

The effects of PGE1, PGE2 and PGD2 on somatostatin, insulin and glucagon secretions were investigated at various glucose concentrations using the isolated perfused rat pancreas. At glucose concentrations varying from 0 to 16.7 mM, PGE1 and PGE2 enhanced somatostatin release in a glucose dose-dependent manner. PGE1 did not significantly stimulate insulin secretion at glucose concentrations of 4.4 mM or less, but did at glucose concentrations of 8.8 mM or more, PGE2 augmented insulin release at 4.4 and 16.7 mM glucose, but not in the absence of glucose. Glucagon release was induced by PGE1 and PGE2 in a biphasic pattern with the maximal response in the absence of glucose. Like PGE1 and PGE2, PGD2 stimulated insulin and glucagon release in a glucose-related fashion. PGD2, however, was not capable of stimulating somatostatin release at various glucose concentrations even in the presence of 16.7 mM glucose. In conclusion, PGE1, PGE2, and PGD2 increase insulin and glucagon secretion in a glucose-dependent manner. PGE1 and PGE2 also stimulate somatostatin release, but PGD2 has no effect on somatostatin secretion at the doses studied.

The effects of stannous chloride on the humoral immune response of mice

The effects of stannous chloride (SnCl2) on primary and secondary immune responses to sheep red blood cells (SRBCs) were examined in mice. I.p. administration of 167 mumol/kg/day of SnCl2 for 3 consecutive days suppressed the number of splenic indirect plaque-forming cells (PFCs) in the primary response and the hemagglutination (HA) and hemolytic reaction (HR) titers of non-2-mercaptoethanol(2-ME)-treated sera in both the primary and secondary immune response. However, tin affected neither the indirect PFC response nor the antibody titers of the 2-ME-treated sera after the secondary immunization, which was performed on day 6 following the primary immunization. These results suggest that the subacute administration of tin suppresses part of the immune response in which IgM antibody production plays an important role, and that the production of IgG in the secondary immune response is little affected, while the IgG production in the primary response is suppressed or delayed.

The effects of the light-dark cycle on humoral and cell-mediated immune responses of mice

When groups of Balb/c mice were immunized with SRBC, a thymus-dependent antigen, at a time interval of 4 h, the number of PFC in the spleen 4 days after immunization exhibited a marked circadian rhythm with an acrophase at -129 degrees (p less than 0.01), while the hemagglutination titers against SRBC also showed a circadian variation with an acrophase at -121 degrees (p less than 0.01). However, the immune response in C3H/HeN mice against PVP, a thymus-independent antigen, especially serum antibody HA titers, did not show a significant circadian rhythm, and the amplitude of the variation was less than that found in Balb/c mice immunized with SRBC. The cell-mediated immune response, contact hypersensitivity to PC, in mice had a marked circadian rhythm with the timing of the challenge of the antigen (acrophase at -129 degrees). From these data it is suggested that the thymus or thymus-derived lymphocytes may play an important role in the circadian rhythm in both humoral and cell-mediated immune responses.