Glutamine Supplementation as an Anticancer Strategy: A Potential Therapeutic Alternative to the Convention

Glutamine, a multifaceted nonessential/conditionally essential amino acid integral to cellular metabolism and immune function, holds pivotal importance in the landscape of cancer therapy. This review delves into the intricate dynamics surrounding both glutamine antagonism strategies and glutamine supplementation within the context of cancer treatment, emphasizing the critical role of glutamine metabolism in cancer progression and therapy. Glutamine antagonism, aiming to disrupt tumor growth by targeting critical metabolic pathways, is challenged by the adaptive nature of cancer cells and the complex metabolic microenvironment, potentially compromising its therapeutic efficacy. In contrast, glutamine supplementation supports immune function, improves gut integrity, alleviates treatment-related toxicities, and improves patient well-being. Moreover, recent studies highlighted its contributions to epigenetic regulation within cancer cells and its potential to bolster anti-cancer immune functions. However, glutamine implementation necessitates careful consideration of potential interactions with ongoing treatment regimens and the delicate equilibrium between supporting normal cellular function and promoting tumorigenesis. By critically assessing the implications of both glutamine antagonism strategies and glutamine supplementation, this review aims to offer comprehensive insights into potential therapeutic strategies targeting glutamine metabolism for effective cancer management.

Supraphysiological glutamine as a means of depleting intracellular amino acids to enhance pancreatic cancer chemosensitivity

Limited efficacy of systemic therapy for pancreatic ductal adenocarcinoma (PDAC) patients contributes to high mortality. Cancer cells develop strategies to secure nutrients in nutrient-deprived conditions and chemotherapy treatment. Despite the dependency of PDAC on glutamine (Gln) for growth and survival, strategies designed to suppress Gln metabolism have limited effects. Here, we demonstrated that supraphysiological concentrations of glutamine (SPG) could produce paradoxical responses leading to tumor growth inhibition alone and in combination with chemotherapy. Integrated metabolic and transcriptomic analysis revealed that the growth inhibitory effect of SPG was the result of a decrease in intracellular amino acid and nucleotide pools. Mechanistically, disruption of the sodium gradient, plasma membrane depolarization, and competitive inhibition of amino acid transport mediated amino acid deprivation. Among standard chemotherapies given to PDAC patients, gemcitabine treatment resulted in a significant enrichment of amino acid and nucleoside pools, exposing a metabolic vulnerability to SPG-induced metabolic alterations. Further analysis highlighted a superior anticancer effect of D-glutamine, a non-metabolizable enantiomer of the L-glutamine, by suppressing both amino acid uptake and glutaminolysis, in gemcitabine-treated preclinical models with no apparent toxicity. Our study suggests supraphysiological glutamine could be a means of inhibiting amino acid uptake and nucleotide biosynthesis, potentiating gemcitabine sensitivity in PDAC.

NFYA promotes malignant behavior of triple-negative breast cancer in mice through the regulation of lipid metabolism

Two splicing variants exist in NFYA that exhibit high expression in many human tumour types. The balance in their expression correlates with prognosis in breast cancer, but functional differences remain unclear. Here, we demonstrate that NFYAv1, a long-form variant, upregulates the transcription of essential lipogenic enzymes ACACA and FASN to enhance the malignant behavior of triple-negative breast cancer (TNBC). Loss of the NFYAv1-lipogenesis axis strongly suppresses malignant behavior in vitro and in vivo, indicating that the NFYAv1-lipogenesis axis is essential for TNBC malignant behavior and that the axis might be a potential therapeutic target for TNBC. Furthermore, mice deficient in lipogenic enzymes, such as Acly, Acaca, and Fasn, exhibit embryonic lethality; however, Nfyav1-deficient mice exhibited no apparent developmental abnormalities. Our results indicate that the NFYAv1-lipogenesis axis has tumour-promoting effects and that NFYAv1 may be a safe therapeutic target for TNBC.

Plasma Metabolomics Predicts Chemotherapy Response in Advanced Pancreatic Cancer

Pancreatic cancer (PC) is one of the deadliest cancers. Developing biomarkers for chemotherapeutic response prediction is crucial for improving the dismal prognosis of advanced-PC patients (pts). To evaluate the potential of plasma metabolites as predictors of the response to chemotherapy for PC patients, we analyzed plasma metabolites using high-performance liquid chromatography-mass spectrometry from 31 cachectic, advanced-PC subjects enrolled into the PANCAX-1 (NCT02400398) prospective trial to receive a jejunal tube peptide-based diet for 12 weeks and who were planned for palliative chemotherapy. Overall, there were statistically significant differences in the levels of intermediates of multiple metabolic pathways in pts with a partial response (PR)/stable disease (SD) vs. progressive disease (PD) to chemotherapy. When stratified by the chemotherapy regimen, PD after 5-fluorouracil-based chemotherapy (e.g., FOLFIRINOX) was associated with decreased levels of amino acids (AAs). For gemcitabine-based chemotherapy (e.g., gemcitabine/nab-paclitaxel), PD was associated with increased levels of intermediates of glycolysis, the TCA cycle, nucleoside synthesis, and bile acid metabolism. These results demonstrate the feasibility of plasma metabolomics in a prospective cohort of advanced-PC patients for assessing the effect of enteral feeding as their primary source of nutrition. Metabolic signatures unique to FOLFIRINOX or gemcitabine/nab-paclitaxel may be predictive of a patient's response and warrant further study.

Combination L-Glutamine with Gemcitabine and Nab-Paclitaxel in Treatment-Naïve Advanced Pancreatic Cancer: The Phase I GlutaPanc Study Protocol

Advanced pancreatic cancer is underscored by progressive therapeutic resistance and a dismal 5-year survival rate of 3%. Preclinical data demonstrated glutamine supplementation, not deprivation, elicited antitumor effects against pancreatic ductal adenocarcinoma (PDAC) alone and in combination with gemcitabine in a dose-dependent manner. The GlutaPanc phase I trial is a single-arm, open-label clinical trial investigating the safety of combination L-glutamine, gemcitabine, and nab-paclitaxel in subjects (n = 16) with untreated, locally advanced unresectable or metastatic pancreatic cancer. Following a 7-day lead-in phase with L-glutamine, the dose-finding phase via Bayesian design begins with treatment cycles lasting 28 days until disease progression, intolerance, or withdrawal. The primary objective is to establish the recommended phase II dose (RP2D) of combination L-glutamine, gemcitabine, and nab-paclitaxel. Secondary objectives include safety of the combination across all dose levels and preliminary evidence of antitumor activity. Exploratory objectives include evaluating changes in plasma metabolites across multiple time points and changes in the stool microbiome pre and post L-glutamine supplementation. If this phase I clinical trial demonstrates the feasibility of L-glutamine in combination with nab-paclitaxel and gemcitabine, we would advance the development of this combination as a first-line systemic option in subjects with metastatic pancreatic cancer, a high-risk subgroup desperately in need of additional therapies.

Fatty Acid Signaling Impacts Prostate Cancer Lineage Plasticity in an Autocrine and Paracrine Manner

Prostate cancer (PCa) affects an estimated 250,000 men every year and causes 34,000 deaths annually. A high-fat diet and obesity are associated with PCa progression and mortality. This study's premise was the novel observation of crosstalk between PCa epithelia and cancer-associated fibroblasts (CAF) in response to palmitate-mediated lineage plasticity. We found that cholesterol activated canonical Hedgehog (Hh) signaling by increasing cilium Gli activity in PCa cells, while palmitate activated Hh independent of Gli. Exogenous palmitate activated SOX2, a known mediator of lineage plasticity, in PCa cells cocultured with CAF. Stroma-derived Wnt5a was upregulated in CAF while cocultured with PCa cells and treated with palmitate. Wnt5a knockdown in CAF inhibited Hh and SOX2 expression in PCa cells from cocultures. These findings supported our proposed mechanism of a high-fat diet promoting Hh signaling-mediated transformation within the tumor microenvironment. SOX2 and Wnt5a expression were limited by the CD36 neutralizing antibody. Mice xenografted with PCa epithelia and CAF tumors were fed a high-fat diet, leading to elevated SOX2 expression and lineage plasticity reprogramming compared to mice fed an isocaloric rodent diet. CD36 inhibition with enzalutamide elevated apoptosis by TUNEL, but limited proliferation and SOX2 expression compared to enzalutamide alone. This study revealed a mechanism for a high-fat diet to affect prostate cancer progression. We found that saturated fat induced lineage plasticity reprogramming of PCa by interaction with CAF through Wnt5a and Hh signaling.

Gut microbiome and pancreatic cancer cachexia: An evolving relationship

Nearly 80% of patients with pancreatic ductal adenocarcinoma (PDAC) develop cachexia along their disease course. Cachexia is characterized by progressive weight loss, muscle wasting, and systemic inflammation and has been linked to poorer outcomes and impairments in quality of life. Management of PDAC cachexia has historically involved a multidisciplinary effort comprised of nutritional support, pancreatic enzyme replacement therapy, and/or pharmacologic interventions. Despite current interventions to mitigate PDAC cachexia, a significant proportion of patients continue to die from complications associated with cachexia underscoring the need for novel insights and treatments for this syndrome. We highlight the feasibility and effectiveness of a recent enteral feeding prospective trial at our institution to improve cachexia outcomes in patients with advanced PDAC. Additionally, we were among the first to characterize the stool microbiome composition in patients with advanced PDAC receiving enteral feeding for the treatment of cachexia. Novel insights into the relationship between enteral nutritional support, cachexia, and the gut microbiome are presented. These promising results are discussed in the context of a potential ability to modulate the stool microbiome as a new interventional strategy to mitigate PDAC cachexia.

Metabolomics in advanced pancreatic cancer (PC) patients (pts) achieving weight stability on enteral feeding for cachexia

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Background: We previously showed that enteral feeding was associated with weight stability and compositional changes in the gut microbiome with increased abundance of the gram-negative genera Veillonella over time. Here, we evaluated the potential of plasma metabolites as predictors of weight stability and high Veillonella abundance in enteral fed pts. Methods: The PANCAX-1 (NCT02400398) prospective trial enrolled 31 cachectic advanced PC pts to receive jejunal tube peptide-based diet for 12 weeks (wks) who were planned for standard chemotherapy. In preplanned exploratory analyses, serial blood samples were collected over 12 wks of enteral feeding. Up to 219 plasma metabolites were analyzed by mass spectrometry and high-performance liquid chromatography. Analytes were compared by relative area under the curve (AUC) and differences evaluated by two-sample t-tests. Pts were stratified by weight stable (WS, defined as weight change < 0.1 kg/baseline BMI-unit over 12 wks of enteral feeding) vs. weight unstable (WU) and high (HV) vs. low Veillonella (LV) abundance (defined by dichotomizing at the mean relative abundance in WS pts). Results: Of 31 cachectic pts enrolled into PANCAX-1, a total of 55 blood samples were collected from 28 pts for plasma metabolomics. Out of 16 evaluable pts, 62.5% receiving enteral feeding met the primary endpoint of weight stability at 12 wks. Plasma metabolomics in 10 pts showed that WU pts (n = 4) had significantly decreased levels of essential amino acids (AAs, L-histidine, L-phenylalanine) and non-essential AAs (L-citrulline, L-tyrosine, all p < 0.05) than WS pts (n = 6) at the end of 12 wks of enteral feeding. In 7 WS pts with complete serial sets of blood samples available, enteral feeding over 12 wks was associated with increases in markers of muscle mass (creatinine) but decreases in nucleotide precursors (all p < 0.05) compared to baseline. Comparison of baseline metabolites between 6 WS pts with HV and 4 WU pts with LV showed that HV was associated with increases in the nucleotide dCDP and essential AA L-isoleucine but decreased TCA cycle metabolite alpha-ketoglutarate (all p < 0.05). Decreases in lactic acid was observed at 12 wks of enteral feeding in HV pts when compared to baseline (p < 0.05). Conclusions: Our findings are hypothesis-generating in that metabolites unique to weight stability and Veillonella abundance may inform future studies of anti-cachexia therapies involving enteral feeding or microbial modulation.

Plasma metabolomics to predict chemotherapy (CTX) response in advanced pancreatic cancer (PC) patients (pts) on enteral feeding for cachexia

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Background: We evaluated the potential of plasma metabolites as predictors of response to CTX in a prospective cohort of pts who received enteral feeding for cachexia and advanced PC. Methods: The PANCAX-1 (NCT02400398) prospective trial enrolled 31 cachectic advanced PC pts to receive jejunal tube peptide-based diet for 12 weeks (wks) who were planned for palliative CTX. Out of 16 evaluable pts, 62.5% receiving enteral feeding met the primary endpoint of weight stability at 12 wks. As part of an exploratory analysis of the PANCAX-1 trial, serial blood samples were collected at 3 predefined timepoints over 12 wks of enteral feeding. Up to 219 plasma metabolites were analyzed by mass spectrometry and high-performance liquid chromatography. Analytes were compared by relative area under the curve (AUC) and differences evaluated by two-sample t-tests. The mean AUC was used in pts with metabolites measured from > 1 timepoint of collection. Pts were stratified by stable disease (SD), partial response (PR), or progressive disease (PD) as best overall response to standard CTX. Results: Of 31 pts with advanced PC prospectively enrolled for enteral feeding, there were 55 blood samples collected from 28 pts available for plasma metabolomics. 20/28 (71%) pts received first-line CTX, the majority of whom (90%) received gemcitabine-based CTX. There were 2 PRs (7%) and 10 with SD (36%) as best response to CTX. Overall, there were statistically significant differences in levels of intermediates involved in multiple metabolic pathways including glycolysis, the tricarboxylic acid (TCA) cycle, fatty acid synthesis, and nucleoside synthesis in pts with PR/SD vs. PD to CTX (all p < 0.05). When stratified by CTX regimen, PD to 5-fluorouracil-based CTX (e.g., FOLFIRINOX) was associated with decreased levels of essential amino acids (AAs, L-leucine, L-methionine, L-tryptophan) and non-essential AAs (L-arginine, L-serine, L-tyrosine, all p < 0.05). For gemcitabine-based CTX (e.g., gemcitabine/nab-paclitaxel), PD was associated with increased levels of intermediates of glycolysis (pyruvate), TCA cycle (L-glutamate), nucleoside synthesis (xanthine), and bile acid metabolism (taurocholic acid, all p < 0.05). Conclusions: We are the first to demonstrate the feasibility of plasma metabolomics in a prospective cohort of advanced PC pts on enteral feeding as their primary source of nutrition. Metabolic signatures unique to FOLFIRINOX or gemcitabine/nab-paclitaxel may be predictive of response and warrant further study.

Cardiomyocytes disrupt pyrimidine biosynthesis in nonmyocytes to regulate heart repair

Various populations of cells are recruited to the heart after cardiac injury, but little is known about whether cardiomyocytes directly regulate heart repair. Using a murine model of ischemic cardiac injury, we demonstrate that cardiomyocytes play a pivotal role in heart repair by regulating nucleotide metabolism and fates of nonmyocytes. Cardiac injury induced the expression of the ectonucleotidase ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), which hydrolyzes extracellular ATP to form AMP. In response to AMP, cardiomyocytes released adenine and specific ribonucleosides that disrupted pyrimidine biosynthesis at the orotidine monophosphate (OMP) synthesis step and induced genotoxic stress and p53-mediated cell death of cycling nonmyocytes. As nonmyocytes are critical for heart repair, we showed that rescue of pyrimidine biosynthesis by administration of uridine or by genetic targeting of the ENPP1/AMP pathway enhanced repair after cardiac injury. We identified ENPP1 inhibitors using small molecule screening and showed that systemic administration of an ENPP1 inhibitor after heart injury rescued pyrimidine biosynthesis in nonmyocyte cells and augmented cardiac repair and postinfarct heart function. These observations demonstrate that the cardiac muscle cell regulates pyrimidine metabolism in nonmuscle cells by releasing adenine and specific nucleosides after heart injury and provide insight into how intercellular regulation of pyrimidine biosynthesis can be targeted and monitored for augmenting tissue repair.

Peripubertal high-fat diet promotes c-Myc stabilization in mammary gland epithelium

Dietary fat consumption during accelerated stages of mammary gland development, such as peripubertal maturation or pregnancy, is known to increase the risk for breast cancer. However, the underlying molecular mechanisms are not fully understood. Here we examined the gene expression profile of mouse mammary epithelial cells (MMECs) on exposure to a high-fat diet (HFD) or control diet (CD). Trp53^-/- female mice were fed with the experimental diets for 5 weeks during the peripubertal period (3-8 weeks of age). The treatment showed no significant difference in body weight between the HFD-fed mice and CD-fed mice. However, gene set enrichment analysis predicted a significant enrichment of c-Myc target genes in animals fed HFD. Furthermore, we detected enhanced activity and stabilization of c-Myc protein in MMECs exposed to a HFD. This was accompanied by augmented c-Myc phosphorylation at S62 with a concomitant increase in ERK phosphorylation. Moreover, MMECs derived from HFD-fed Trp53^-/- mouse showed increased colony- and sphere-forming potential that was dependent on c-Myc. Further, oleic acid, a major fatty acid constituent of the HFD, and TAK-875, an agonist to G protein-coupled receptor 40 (a receptor for oleic acid), enhanced c-Myc stabilization and MMEC proliferation. Overall, our data indicate that HFD influences MMECs by stabilizing an oncoprotein, pointing to a novel mechanism underlying dietary fat-mediated mammary carcinogenesis.

CBMT-43. INTEGRATED LIPIDOMIC AND MOLECULAR ANALYSIS REVEALS A SUBSET OF GLIOBLASTOMA VULNERABLE TO FERROPTOSIS

Cancers, including the universally lethal glioblastoma (GBM), have reprogrammed lipid metabolism to fuel tumor growth. However, the molecular alterations responsible for aberrant lipid metabolism, and the potential for identifying new therapeutic opportunities are not fully understood. To systematically investigate the GBM lipidome, we performed integrated transcriptomic, genomic and shotgun lipidomic analysis of a library of molecularly diverse patient-derived GBM cells (n=30). Using this comprehensive approach, we discovered two GBM sub-groups defined by their combined molecular and lipidomic profile. Polyunsaturated fatty acids (PUFAs) were among the most significant lipids that distinguished these two groups of GBM tumors. Intriguingly, this lipid metabolic phenotype was associated with heightened sensitivity to ferroptosis – a newly discovered form of regulated cell death. As PUFA oxidation is a critical feature of ferroptosis, our findings suggest a novel association between specific molecular signatures of GBM, lipid metabolism and ferroptosis. This relationship may present a new therapeutic opportunity to target ferroptosis in a molecularly-defined subset of GBMs.

Retinoblastoma Inactivation Induces a Protumoral Microenvironment via Enhanced CCL2 Secretion

Cancer cell-intrinsic properties caused by oncogenic mutations have been well characterized; however, how specific oncogenes and tumor suppressors impact the tumor microenvironment (TME) is not well understood. Here, we present a novel non-cell-autonomous function of the retinoblastoma (RB) tumor suppressor in controlling the TME. RB inactivation stimulated tumor growth and neoangiogenesis in a syngeneic and orthotropic murine soft-tissue sarcoma model, which was associated with recruitment of tumor-associated macrophages (TAM) and immunosuppressive cells such as Gr1⁺CD11b⁺ myeloid-derived suppressor cells (MDSC) or Foxp3⁺ regulatory T cells (Treg). Gene expression profiling and analysis of genetically engineered mouse models revealed that RB inactivation increased secretion of the chemoattractant CCL2. Furthermore, activation of the CCL2-CCR2 axis in the TME promoted tumor angiogenesis and recruitment of TAMs and MDSCs into the TME in several tumor types including sarcoma and breast cancer. Loss of RB increased fatty acid oxidation (FAO) by activating AMP-activated protein kinase that led to inactivation of acetyl-CoA carboxylase, which suppresses FAO. This promoted mitochondrial superoxide production and JNK activation, which enhanced CCL2 expression. These findings indicate that the CCL2-CCR2 axis could be an effective therapeutic target in RB-deficient tumors. SIGNIFICANCE: These findings demonstrate the cell-nonautonomous role of the tumor suppressor retinoblastoma in the tumor microenvironment, linking retinoblastoma loss to immunosuppression.

Involvement of Prokineticin 2-expressing Neutrophil Infiltration in 5-Fluorouracil-induced Aggravation of Breast Cancer Metastasis to Lung

Adjuvant chemotherapy is used for human breast cancer patients, even after curative surgery of primary tumor, to prevent tumor recurrence primarily as a form of metastasis. However, anticancer drugs can accelerate metastasis in several mouse metastasis models. Hence, we examined the effects of postsurgical administration with 5-fluorouracil (5-FU), doxorubicin, and cyclophosphamide, on lung metastasis process, which developed after the resection of the primary tumor arising from the orthotopic injection of a mouse triple-negative breast cancer cell line, 4T1. Only 5-FU markedly increased the numbers and sizes of lung metastasis foci, with enhanced tumor cell proliferation and angiogenesis as evidenced by increases in Ki67-positive cell numbers and CD31-positive areas, respectively. 5-FU-mediated augmented lung metastasis was associated with increases in intrapulmonary neutrophil numbers and expression of neutrophilic chemokines, Cxcl1 and Cxcl2 in tumor cells, with few effects on intrapulmonary T-cell or macrophage numbers. 5-FU enhanced Cxcl1 and Cxcl2 expression in 4T1 cells in a NFκB-dependent manner. Moreover, the administration of a neutrophil-depleting antibody or a Cxcr2 antagonist, SB225002, significantly attenuated 5-FU-mediated enhanced lung metastasis with depressed neutrophil infiltration. Furthermore, infiltrating neutrophils and 4T1 cells abundantly expressed prokineticin-2 (Prok2) and its receptor, Prokr1, respectively. Finally, the administration of 5-FU after the resection of the primary tumor failed to augment lung metastasis in the mice receiving Prokr1-deleted 4T1 cells. Collectively, 5-FU can enhance lung metastasis by inducing tumor cells to produce Cxcl1 and Cxcl2, which induced the migration of neutrophils expressing Prok2 with a capacity to enhance 4T1 cell proliferation. Mol Cancer Ther; 17(7); 1515-25. ©2018 AACR.

MicroRNA-140 mediates RB tumor suppressor function to control stem cell-like activity through interleukin-6

We established an in vitro cell culture system to determine novel activities of the retinoblastoma (Rb) protein during tumor progression. Rb depletion in p53-null mouse-derived soft tissue sarcoma cells induced a spherogenic phenotype. Cells retrieved from Rb-depleted spheres exhibited slower proliferation and less efficient BrdU incorporation, however, much higher spherogenic activity and aggressive behavior. We discovered six miRNAs, including mmu-miR-18a, -25, -29b, -140, -337, and -1839, whose expression levels correlated tightly with the Rb status and spherogenic activity. Among these, mmu-miR-140 appeared to be positively controlled by Rb and to antagonize the effect of Rb depletion on spherogenesis and tumorigenesis. Furthermore, among genes potentially targeted by mmu-miR-140, Il-6 was upregulated by Rb depletion and downregulated by mmu-mir-140 overexpression. Altogether, we demonstrate the possibility that mmu-mir-140 mediates the Rb function to downregulate Il-6 by targeting its 3′-untranslated region. Finally, we detected the same relationship among RB, hsa-miR-140 and IL-6 in a human breast cancer cell line MCF-7. Because IL-6 is a critical modulator of malignant features of cancer cells and the RB pathway is impaired in the majority of cancers, hsa-miR-140 might be a promising therapeutic tool that disrupts linkage between tumor suppressor inactivation and pro-inflammatory cytokine response.

Undifferentiated State Induced by Rb-p53 Double Inactivation in Mouse Thyroid Neuroendocrine Cells and Embryonic Fibroblasts

Retinoblastoma tumor suppressor protein (RB) is inactivated more frequently during tumor progression than during tumor initiation. However, its exact role in controlling the malignant features associated with tumor progression is poorly understood. We established in vivo and in vitro models to investigate the undifferentiated state induced by Rb inactivation. Rb heterozygous mice develop well-differentiated thyroid medullary carcinoma. We found that additional deletion of Trp53, without change in lineage, converted these Rb-deficient tumors to a poorly differentiated type associated with higher self-renewal activity. Freshly prepared mouse embryonic fibroblasts (MEFs) of Rb(-/-) ; Trp53(-/-) background formed stem cell-like spheres that expressed significant levels of embryonic genes despite of lacking the ability to form colonies on soft agar or tumors in immune-deficient mice. This suggested that Rb-p53 double inactivation resulted in an undifferentiated status but without carcinogenic conversion. We next established Rb(-/-) ; N-ras(-/-) MEFs that harbored a spontaneous carcinogenic mutation in Trp53. These cells (RN6), in an Rb-dependent manner, efficiently generated spheres that expressed very high levels of embryonic genes, and appeared to be carcinogenic. We then screened an FDA-approved drug library to search for agents that suppressed the spherogenic activity of RN6 cells. Data revealed that RN6 cells were sensitive to specific agents including ones those are effective against cancer stem cells. Taken together, all these findings suggest that the genetic interaction between Rb and p53 is a critical determinant of the undifferentiated state in normal and tumor cells.

An in vitro system to characterize prostate cancer progression identified signaling required for self-renewal

Mutations in RB and PTEN are linked to castration resistance and poor prognosis in prostate cancer. Identification of genes that are regulated by these tumor suppressors in a context that recapitulates cancer progression may be beneficial for discovering novel therapeutic targets. Although various genetically engineered mice thus far provided tumor models with various pathological stages, they are not ideal for detecting dynamic changes in gene transcription. Additionally, it is difficult to achieve an effect specific to tumor progression via gain of functions of these genes. In this study, we developed an in vitro model to help identify RB- and PTEN-loss signatures during the malignant progression of prostate cancers. Trp53^-/- ; Rb^f/f , Trp53^-/- ; Pten^f/f , and Trp53^-/- ; Rb^f/f ; Pten^f/f prostate epithelial cells were infected with AD-LacZ or AD-Cre. We found that deletion of Rb, Pten or both stimulated prostasphere formation and tumor development in immune-compromised mice. The GO analysis of genes affected by the deletion of Rb or Pten in Trp53^-/- prostate epithelial cells identified a number of genes encoding cytokines, chemokines and extracellular matrix remodeling factors, but only few genes related to cell cycle progression. Two genes (Il-6 and Lox) were further analyzed. Blockade of Il-6 signaling and depletion of Lox significantly attenuated prostasphere formation in 3D culture, and in the case of IL-6, strongly suppressed tumor growth in vivo. These findings suggest that our in vitro model may be instrumental in identifying novel therapeutic targets of prostate cancer progression, and further underscore IL-6 and LOX as promising therapeutic targets. © 2015 Wiley Periodicals, Inc.

[Cardiovascular surgery for patient with pulmonary dysfunction]

Pulmonary dysfunction is one of the major factors for postoperative pulmonary complication. Preoperative pulmonary function test reveals possible operative risk. Particularly, in the patient with stage Ⅲ and Ⅳ chronic obstructive pulmonary disease (COPD), open heart surgery with cardiopulmonary bypass is at higher risk of complication. In these patients, safe and reliable surgical procedures are required. Preoperatively, quitting smoking and incentive spirometry can reduce the risk of pulmonary complications. Furthermore, noninvasive positive pressure ventilation (NPPV) on the appropriate indication can help to improve the outcome in the patients with pulmonary dysfunction.

The inositol phosphatase SHIP2 negatively regulates insulin/IGF-I actions implicated in neuroprotection and memory function in mouse brain

Impairment of insulin and IGF-I signaling in the brain is one of the causes of dementia associated with diabetes mellitus and Alzheimer's disease. However, the precise pathological processes are largely unknown. In the present study, we found that SH2-containing inositol 5'-phosphatase 2 (SHIP2), a negative regulator of phosphatidylinositol 3,4,5-trisphosphate-mediated signals, is widely expressed in adult mouse brain. When a dominant-negative mutant of SHIP2 was expressed in cultured neurons, insulin signaling was augmented, indicating physiological significance of endogenous SHIP2 in neurons. Interestingly, SHIP2 mRNA and protein expression levels were significantly increased in the brain of type 2 diabetic db/db mice. To investigate the impact of increased expression of SHIP2 in the brain, we further employed transgenic mice overexpressing SHIP2 and found that increased amounts of SHIP2 induced the disruption of insulin/IGF-I signaling through Akt. Neuroprotective effects of insulin and IGF-I were significantly attenuated in cultured cerebellar granule neurons from SHIP2 transgenic mice. Consistently, terminal deoxynucleotide transferase-mediated dUTP nick end labeling assay demonstrated that the number of apoptosis-positive cells was increased in cerebral cortex of the transgenic mice at an elderly age. Furthermore, SHIP2 transgenic mice exhibited impaired memory performance in the Morris water maze, step-through passive avoidance, and novel-object-recognition tests. Importantly, inhibition of SHIP2 ameliorated the impairment of hippocampal synaptic plasticity and memory formation in db/db mice. These results suggest that SHIP2 is a potent negative regulator of insulin/IGF-I actions in the brain, and excess amounts of SHIP2 may be related, at least in part, to brain dysfunction in insulin resistance with type 2 diabetes.

Compensatory cortical activation during performance of an attention task by patients with diffuse axonal injury: a functional magnetic resonance imaging study

OBJECTIVE

To determine how cortical compensation occurs in higher cognitive systems during the recovery phase of diffuse axonal injury (DAI).

DESIGN

12 right-handed patients with a magnetic resonance imaging (MRI) lesion pattern compatible with pure DAI were identified. Pure DAI was defined as finding of traumatic microbleeds on T2*-weighted gradient-echo images in the absence of otherwise traumatic or non-traumatic MRI abnormalities. 12 matched healthy controls were also enrolled. Functional magnetic resonance imaging (fMRI) was used to assess brain activation during a working memory test (Paced Visual Serial Attention Test (PVSAT)).

RESULTS

No significant group differences were observed in reaction times for the PVSAT. Although patients with pure DAI committed a few errors during the PVSAT, controls respond correctly to each probe. Controls showed activations in the left frontal gyrus, left parietal gyrus and right inferior parietal gyrus. Patients with pure DAI showed activations in the left inferior frontal gyrus, right inferior frontal gyrus and right middle frontal gyrus. Between-group analysis of the PVSAT task showed significantly greater activation of the right inferior frontal gyrus (BA 45) and right middle frontal gyrus (BA 9) in patient with pure DAI versus controls.

CONCLUSIONS

Patients with pure DAI require compensatory activation of the contralateral (right) prefrontal region to carry out activities similar to healthy controls. These findings provide further evidence for the adaptive capacity of neuronal systems and brain plasticity during the recovery stages of DAI.

Rehabilitation technique facilitates association cortices in hemiparetic patients: functional MRI study

We used fMRI to study brain activation with facilitative rehabilitation techniques (passive hand movements and visual feedback) in two patients with subcortical lesions. Two tasks were given in a sequence. The first task (trial 1) was repetitive hand grasping by the paretic hand at a rate of 0.5 Hz with the eyes closed. The second task (trial 2), the facilitative rehabilitation technique, included task 1 plus support by a trainer to move the paretic hand with the eyes open to get visual feedback of the movement. The data were analyzed by a subtractive method. When task 1 was subtracted from task 2, it was found that the bilateral visual cortex, contralateral premotor cortex and posterior parietal cortex were involved with the passive hand movement and visual feedback. These facilitative rehabilitation techniques may integrate networks between sensory information and motor commands, and lead to functional reorganization.

Prognostic factors of nosocomial pneumonia in general wards: a prospective multivariate analysis in Japan

To determine prognostic factors of nosocomial pneumonia in general wards, we performed prospective clinical study using multivariate statistical analysis. Eighty patients with nosocomial pneumonia in our units were enrolled in the study between December, 1996 and January 1998. Clinical setting and severity of pneumonia were evaluated, and laboratory data were collected at the occurrence of nosocomial pneumonia. Death due to nosocomial pneumonia occurred in 29 of 80 patients (mortality rate 36%). Univariate analysis showed the following factors associated with mortality: the presence of an ultimately or rapidly fatal underlying condition, prior antibiotics use, use of antacids, presence of 'high-risk' micro-organisms, sepsis, respiratory failure, multiple organ failure, bilateral chest X-ray infiltrates, a Simplified Acute Physiology Score (SAPS) index > or = 11, albumin < 3.0 g dl(-1), and lactate dehydrogenase (LDH) > or = 796 IUI(-1). Furthermore, multivariate analysis identified three factors significantly associated with mortality: the presence of an ultimately or rapidly fatal underlying condition [odds ratio (OR)=7.0; 95% confidence interval (CI)=1.2-41.1; P=0.03]; SAPS index > or = 11 (OR=7.6; 95% CI=1.1-51.9, P=0.04); LDH > or = 796 IUI(-1) (OR=28.2; 95% CI=2.0-406, P=0.01). Our study indicates that host factors and disease severity factors are important prognostic factors of nosocomial pneumonia in general wards.

Beta(3)-adrenoceptor agonists for the treatment of frequent urination and urinary incontinence: 2-[4-(2-[[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino]ethyl)phenoxy]-2-methylpropionic acid

In a search for novel analogues of beta(3)-adrenoceptor (AR) agonists relaxing the bladder for treatment of urinary dysfunction, 2-[4-(2-[[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino]ethyl)phenoxy]-2-methylpropionic acids (1a-e), into which a fibrate-like structure had been incorporated, were synthesised. Compound 1a was found to be a selective beta(3)-AR agonist in functional assays using the ferret detrusor (beta(3)-AR), rat uterus (beta(2)-AR), and rat atrium (beta(1)-AR); beta(3): EC(50)=7.8 nM, beta(2): IC(50)=7,300 nM, beta(1): EC(20)=23,000 nM. The introduction of a chlorine atom or methyl substituent at the ortho-position on the phenyl ring of 1a further improved beta(3)-AR selectivity. In an in vivo study, 1a lowered intrabladder pressure (ED(50)=31 microg/kg) in rats, without increasing heart rate, in keeping with the in vitro results. Consequently, it is proposed that 1a and its analogues (1b-e), possess beta(3)-AR agonistic activity in the absence of undesirable beta(1)- or beta(2)-AR mediated actions, and may be useful for clinical treatment and pharmacological studies.

Effect of cryopreservation period on rat tracheal allografts

BACKGROUND

The effect of cryopreservation on tracheal allogenicity is still unclear. Therefore, in this study, we assessed the effect of cryopreservation period on tracheal allografts in 62 rats.

METHODS

Each transplant consisted of a 3-ring segment of the trachea harvested from 8 Lewis rats, immersed in preservation solution, and cryopreserved and stored in a Bicell biofreezing vessel in a deep freezer at -80 degrees C. Six tracheal grafts without cryopreservation that underwent a heterotopically syngeneic transplantation into the omentum served as controls. Forty-eight tracheal segments were randomly assigned to 8 groups according to period of cryopreservation, which ranged from 0 to 12 months (0, 0.5 [2 weeks], 1, 2, 3, 6, 9 and 12 months). The cryopreserved grafts were then thawed and heterotopically implanted into the omentum of recipient Brown-Norway rats. After 28 days, the tracheal segments were then evaluated histologically.

RESULTS

All isografts in Group 1 were intact, whereas the allografts undergoing a particularly shorter period of cryopreservation showed a more stenotic lumen. Prolonged periods of cryopreservation tended to show decreasing tendencies of viability of chondrocytes, mononuclear cell infiltration and sub-epithelial thickness, whereas all allografts showed a uniformly denuded epithelium, irrespective of the length of cryopreservation.

CONCLUSIONS

A longer period of cryopreservation may help to maintain a better patency of tracheal allografts by preventing an allogeneic response. Reduced tracheal allogenicity may be associated with a decreased viability of chondrocytes by cryopreservation.

Discovery of novel N-phenylglycine derivatives as potent and selective beta(3)-adrenoceptor agonists for the treatment of frequent urination and urinary incontinence

With a novel assay using isolated ferret detrusor to estimate beta(3)-adrenoceptor agonistic activity, we found that a series of glycine derivatives of ritodrine, a beta(2)-adrenoceptor agonist, are potent beta(3)-adrenoceptor agonists, with excellent selectivity versus beta(1) and beta(2) subtypes. Substitution of halogens in the phenyl ring increased potency and selectivity for the beta(3)-adrenoceptor, and this was dependent upon the position of the halogens. The chlorine-substituted derivatives 3f-i exhibited potent beta(3)-adrenoceptor-mediated relaxation of ferret detrusor (EC(50) = 0.93, 11, 14, and 160 nM) and higher potency at beta(3)-adrenoceptors than at beta(1) or beta(2). The intravenous administration of 3h significantly reduced the urinary bladder pressure in anesthetized male rats (ED(50) = 48 microg/kg) without cardiovascular side effects. This article is the first report of structure-activity relationships (SAR) concerning beta(3)-adrenoceptor agonists as agents for the treatment of urinary frequency and incontinence.

Feasibility of cryopreserved tracheal xenotransplants with the use of short-course immunosuppression

OBJECTIVE

We evaluated the feasibility of discordant xenotransplantation of the cryopreserved trachea with intermittent immunosuppression to help solve the shortage of donor tracheas.

METHODS

Two experiments were performed with heterotopic transplantation models in 14 guinea pigs and 85 rats. So that the minimal dose of FK506 for viable fresh xenografts could be determined, FK506 was given in escalating doses (0, 1.5, 2.5, and 3.5 mg/kg) for recipient animals after xenogeneic transplantation. With the goal of obtaining a long-term survival of the xenografts, the effect of cryopreservation on xenografts was assessed and thereafter different cycles of immunosuppression every third week were evaluated in fresh or cryopreserved xenografts in the second experiment.

RESULTS

An FK506 dosage of more than 2.5 mg/kg per day was much more effective than smaller dosages, as demonstrated by morphologic assessment. A higher dosage of FK506 potentially delayed the rejection of xenografts and can thus maintain tracheal xenograft viability for less than 4 weeks in rat recipients. In experiment 2, the cryopreserved xenografts showed less histologic viability than fresh xenografts but greater patency of the lumen. The patency of cryopreserved xenografts was favorably maintained for a longer period than that of fresh xenografts with either the same number or more cycles of immunosuppression.

CONCLUSIONS

We conclude that the synergistic effect of cryopreservation and adequate intermittent immunosuppression may enable tracheal xenografts to remain viable over longer periods.

Visual symptoms in epilepsy and migraine: localization and patterns

PURPOSE

To clarify differences in the localization of visual symptom patterns in epilepsy and migraine, we analyzed patient-generated illustrations of visual symptoms.

METHODS

Patients were asked to draw their visual symptoms from memory using marker pens of 12 colors. All patients illustrated their symptoms on a template sheet representing the binocular visual field. We analyzed a total of 67 illustrations from 54 patients aged 6-40 years: 28 with epilepsy, 23 with migraine, and 3 with migraine-epilepsy syndrome.

RESULTS

With respect to positive visual manifestations, those of epileptic patients were predominantly centrally localized (20 of 24, 83%), whereas those of migraine patients were predominantly peripherally localized (10 of 13, 77%) (p < 0.0001). With respect to negative visual symptoms, those in epilepsy were commonly diffuse (10 of 14, 71%) compared with those in migraine, which were peripheral (9 of 12, 75%) (p < 0.05).

CONCLUSIONS

Results of this study suggest that the localization of visual symptoms differs between epilepsy and migraine.

Limit of warm ischemia time before cryopreservation in rat tracheal isografts

BACKGROUND

The viability of cadaveric tracheal grafts undergoing cryopreservation is still unclear. We evaluated the limit of warm ischemia time before cryopreservation in rat tracheal isografts.

METHODS

Each isograft was harvested from donor rats 0 to 48 hours (0, 6, 12, 18, 24, and 48 hours) after circulatory arrest, immersed in the preservative solution, and stored in a deep freezer until reaching -80 degrees C and then was kept in liquid nitrogen for 3 months. Heterotopic transplantation into the omentum was performed after the isografts were thawed. Graft morphology 3 months after transplantation was assessed.

RESULTS

The stepwise increase of warm ischemia time significantly reduced graft survival. A prolonged period of warm ischemia had a degenerative effect on both the epithelium and cartilage. The morphology of the epithelium and cartilage in isografts undergoing warm ischemia for less than 18 hours was better preserved, whereas it deteriorated in isografts undergoing warm ischemia for more than 24 hours.

CONCLUSIONS

We thus conclude that the permissible period of warm ischemia before 3-month cryopreservation to maintain tracheal isograft viability is 18 hours in rats.

A syndrome of inappropriate secretion of antidiuretic hormone associated with pleuritis caused by OK-432

We here report a case presenting with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) after having been treated for pleurodesis with OK-432, which is a lyophilized preparation of an attenuated strain of Streptococcus pyogenes. The patient, who had undergone a subtotal esophagectomy 4 years previously, was referred to our department after the diagnosis of a metastatic lung tumor. A right lower lobectomy of the lung was performed, and prolonged air leakage from a pulmonary fistula thereafter developed because of the dissection of severe pleural adhesion. OK-432 (5 klinische einheiten) was administered to the pleural cavity 3 times. On the 13th postoperative day, the patient began to complain of general fatigue and nausea. SIADH was diagnosed based on laboratory findings such as hyponatremia, serum hypo-osmolality and a high excretion of sodium in the urine. A restriction of the fluid intake with a sodium supplement resulted in the return to a normal serum level within 2 weeks. We therefore concluded that the intrapleural instillation of OK-432 had apparently caused SIADH in this case, because no other causes could be found.

[Recurrent tongue biting due to hypnic myoclonia in infancy]

We report a 15-month-old female infant who had recurrent tongue biting due to hypnic myoclonia. She began to bite her tongue and bleed when she was 9 months old. The tongue biting was accompanied by generalized myoclonus and was seen only during drowsiness. On admission at 15 months of age, she was observed by video-EEG monitoring. There were hypnic jerks with powerful closure of the mouth and severe screaming, but no accompanying evidence of epileptic discharges. The tongue biting with hypnic myoclonia disappeared spontaneously at 22 months of age, and was considered to be an age-dependent phenomenon related to the maturation of the brain and to the development of oral functions.

Short-course immunosuppression using FK506 for rat tracheal allografts

BACKGROUND

A minimizing immunosuppression after a tracheal allotransplantation is desirable.

METHODS

We examined the usefulness of a short-course of immunosuppression after tracheal allotransplantation in rat. Each transplant consisting of a 5-ring segment was heterotopically implanted into the omentum. Four animals underwent a syngeneic transplantation and thus served as controls (Group A). Thirty animals underwent an allogeneic transplantation and were randomly classified into 4 groups as follows: No immunosuppression (Group B, n=6), treatment with 0.5 mg/kg of Tacrolims (FK506) (Group C, n=8), 1.0 mg/kg of FK506 (Group D, n=8), and 1.5 mg/kg of FK506 (Group E, n=8). Different doses of FK506 were administered intramuscularly for only three consecutive days after heterotopic tracheal allotransplantation. The serum levels of FK506 were then investigated 3, 7, 14, 21, and 28 days after transplantation in groups C, D, and E. All rats were killed 28 days after transplantation and then the implanted tracheae were harvested, and evaluated histologically.

RESULTS

All animals survived for the protocol period. The graft morphology of Group E was significantly better than that of groups B, C, and D regarding both macro- and microscopy, and also showed the same findings as that of Group A, except for low-grade mononuclear cell infiltration. Only in Group E, the FK506 blood level was maintained at over 0.5 ng/ml, which is the lowest detectable limit in this assay, until 21 days after transplantation.

CONCLUSIONS

We thus conclude that 1.5 mg/kg of FK506 which was administered for only three consecutive days after surgery may be used to maintain the morphology of tracheal allografts in rats for 28 days after transplantation.

A novel mutation of KCNQ3 (c.925T-->C) in a Japanese family with benign familial neonatal convulsions

At present, only one mutation of KCNQ3, a KCNQ potassium channel gene, has been identified as a cause of benign familial neonatal convulsions type 2 (BFNC2). We found a T to C substitution (c.925T-C) on one allele of affected individuals in a Japanese family with BFNC but not on 200 alleles from healthy subjects. c.925T-->C replaced Trp309, a conserved residue within the P-loop of the KCNQ potassium channel family that holds the channel pore open, with an Arg (W309R). We report c.925T-->C as the second mutation of KCNQ3 responsible for BFNC2.

Combined effects of inhaled nitric oxide and positive end-expiratory pressure during mechanical ventilation in acute respiratory distress syndrome

We studied the combined effects of inhaled nitric oxide (INO) and positive end expiratory pressure (PEEP) during mechanical ventilation in patients with acute respiratory distress syndrome (ARDS). Eleven patients received 0 and 4 parts per million of INO in random order for 30 min at PEEP levels of 0, 5, and 10 cm H2O. Respiratory and cardiovascular parameters were measured. The addition of INO and PEEP significantly improved arterial oxygenation (p < 0.005 and p < 0.0001, respectively). The combined effect of INO and PEEP on arterial oxygenation was remarkable during 10 cm H2O PEEP. There was synergistic effect on arterial oxygenation by combining INO and 10 cm H2O PEEP. The present study showed that the combination of INO and 10 cm H2O PEEP enhanced arterial oxygenation in patients with ARDS.

Chronic expanding hematoma in the chest

We report the successful surgical treatment of chronic expanding hematoma in the chest. Four patients who had previously undergone artificial pneumothorax, thoracoplasty or tumor extirpation more than 30 years earlier recently became aware of a slowly growing mass. Chronic expanding hematoma which developed into very large masses over a long period of time were thus successfully resected. These patients are now all in good health with no recurrence after the operation. It is important to monitor such patients' laboratory data for hemostasis including the platelet cell counts, the % prothrombin time and the D-dimer, both before and immediately after operation, and the intraoperative bleeding volume.

[Case report of muscle cramp versus focal epilepsy]

We report here a boy suffering from muscle cramps in the right upper extremity. At 32 days of age, he developed purulent meningitis followed by paresis of the right upper extremity. From infancy he had intermittent episodes myoclonus-like involving the right hand. Since he also had true epileptic seizures with loss of consciousness, ocular deviation, and vomiting at 6 and 8 years of age, he was treated with anti-epileptic drugs as therapy for focal motor seizures. At 6 years of age, these episodes increased in frequency. The cramps spread from the right hand to involve the entire upper extremity with pain. At the age of 10, he was referred to Hirosaki University Hospital and was admitted. Using closed circuit television with continuous EEG and EMG monitoring we observed during his episodes repeated EMG abnormalities consisting of continuous discharges of polyphasic motor unit potentials, but no epileptic EEG discharges. We diagnosed these episodes as muscle cramp. His muscle cramps were controlled by medication with muscle relaxants and Chinese medicines. This case illustrates that the differential diagnosis between muscle cramps and epileptic seizures is important for proper treatment.

Maximal period of cryopreservation with the Bicell biofreezing vessel for rat tracheal isografts

OBJECTIVE

The maximal period of cryopreservation for the trachea is still unsolved. We assessed the maximal period of cryopreservation using the Bicell biofreezing vessel as an easy and cheap slow-freezing instrument for viable tracheal grafts in 95 rats.

METHODS

Each isograft was harvested from 17 donor rats, immersed in the preservative solution, and stored in a Bicell device in a deep freezer at -80 degrees C. The tracheal isografts were then randomly assigned to 9 groups according to cryopreservation periods ranging from 0 to 12 months. Included in the 9 groups were 2 subgroups (n = 6 per subgroup) that were observed immediately after being thawed and 1 month after heterotopic transplantation into the omentum after being thawed. Four subgroups (n = 6 per subgroup) were added according to the cryopreservation period for 1, 3, 6, and 12 months to evaluate the graft morphology 3 months after being thawed and transplanted heterotopically.

RESULTS

A prolonged period of cryopreservation had a degenerative effect on both the epithelium and cartilage. One month after transplantation, degeneration was more pronounced in the cartilage than in the epithelium, as characterized by the viable chondrocyte ratio and the epithelial score of isografts undergoing cryopreservation for more than 9 months. Three months after transplantation, the morphology of the epithelium and cartilage in isografts undergoing cryopreservation for less than 3 months was better preserved, whereas the morphology of both deteriorated in isografts undergoing cryopreservation for more than 6 months.

CONCLUSIONS

We conclude that the permissible period of cryopreservation to maintain tracheal isograft viability in this simple system using a Bicell biofreezing vessel is 3 months.

Results of surgical treatment of lung cancer in octogenarians

The treatment of potentially resectable lung cancer in octogenarians has become a frequent clinical problem, due to the increasing number of elderly people maintaining an active daily life. In the present study, we reviewed the clinical records of patients to evaluate the results of the surgical treatment of lung cancer in octogenarians. From 1992 to 1995, 18 patients aged 80 years or older (octogenarians) with primary lung cancer underwent surgical resections including: three (16.7%) sleeve lobectomies, nine (50.0%) lobectomies, one (5.5%) segmentectomy, and five (27.8%) partial resections. The postoperative complication rate was 50% in octogenarians; however, no fatal complications were observed. The 5-year survival rate was 42.6%, which was similar to that obtained in younger patients. Based on our findings, the surgical treatment of lung cancer can thus be performed in selected octogenarians without increasing either morbidity or mortality, while also obtaining long-term survival.

Therapeutic effect of erythromycin on influenza virus-induced lung injury in mice

Erythromycin (EM) is an antibiotic with potent antiinflammatory effects that is used for treating chronic lower respiratory tract infections. It has been shown that free radicals, such as the superoxide anion and nitric oxide (NO), are pathogenic molecules in viral disease. Much attention has been given to a critical role of NO in the pathologic events of various inflammatory diseases. In the present study, we evaluated the effects of EM on influenza-virus-induced pneumonia in mice infected with a lethal dose of influenza virus A/Kumamoto/Y5/67 (H2N2). The administration of EM at a dose of 3.3 mg/kg/d (intraperitoneally, from Days 1 to 6 after infection), significantly improved the survival rate of mice infected with influenza virus, and the survival rate of the virus-infected mice at Day 20 after infection increased in a dose-dependent fashion with EM administered to the animals, from 14% among controls to 42% among animals given EM at 1.0 mg/kg/d and 57% among those given EM at 3.3 mg/kg/d. The induction of interferon-gamma (IFN-gamma) in the mouse lung was inhibited by EM treatment on Day 6 after infection. Simultaneously, the number of inflammatory cells recovered in lung lavage fluid 6 d after virus infection was significantly reduced by the treatment with EM. The EM treatment resulted in a dose-dependent decrease in the level of nitrite/nitrate (metabolites of NO) in the serum and the NO synthase (NOS)-inducting potential in the lungs of the virus-infected mice. These results indicate that EM may have substantial therapeutic value for various acute inflammatory disorders such as influenza-virus-induced pneumonia, by inhibiting inflammatory-cell responses and suppressing NO overproduction in the lung.

Effectiveness of fructose-modified chitosan as a scaffold for hepatocyte attachment

Free amino groups of chitosan, a substance which has previously been shown to be a good scaffold for hepatocyte attachment, were covalently modified with fructose. The modification significantly increased the number of cells that could be attached on the surface of chitosan gel. Rat hepatocytes cultivated on fructose-chitosan behaved similarly to those on unmodified chitosan, i.e., they retained the spherical shape they have in vivo, and released much less lactate dehydrogenase than cells attached on a collagen-coated surface. The modification with fructose did not alter the important characteristics of chitosan for hepatocyte culture: liver-specific functions such as urea synthesis and drug metabolism were stably maintained for 5 d in the hepatocytes cultured on fructose-chitosan. In sharp contrast, hepatocytes attached on a collagen-coated surface underwent a severe morphological change, from spherical to flat, and lost almost all their lidocaine-removal activity within 5d. A very thin fructose-chitosan layer was also applied onto the collagen-coated surfaces of polystyrene plates and a dextran microcarrier by crosslinking free amino groups in the chitosan and collagen with glutaraldehyde to fix the thin layer. Hepatocytes on the fructose-chitosan-coated surface retained their spherical shape, masking the cell-flattening effect of the collagen layer. Perfusion culture was then carried out using a hollow-fiber cartridge in which hepatocytes attached on fructose-chitosan-coated microcarriers were suspended in the extracapillary space: the liver-specific functions were stably maintained during 4d of the culture. A fructose-chitosan-coated surface thus appears to be a very promising scaffold for hepatocyte attachment which can be used in cellular biological studies of liver functions, especially in relation to cytochrome P450, as well as in bioartificial liver support systems.

Chronic expanding hematoma in the chest

We herein report the successful surgical treatment of 2 cases of chronic expanding hematoma in the chest. The first patient, who had undergone thoracoplasty 42 years earlier due to tuberculosis, became aware of a slowly growing mass protruding in the lateral thoracic wall. The second patient, who had tuberculous pleurisy 36 years earlier, was referred to our department because of a slowly expanding intrathoracic mass revealed by a roentgenogram. The tumors, which were encapsulated chronic hematomas, were both surgically resected. These cases are rare because of the development of a very large mass after undergoing treatment for tuberculosis more than 30 years previously.

Effects of granulocyte and granulocyte-macrophage colony-stimulating factors in a neutropenic murine model of trichosporonosis

We produced disseminated trichosporonosis in a neutropenic murine model with Trichosporon asahii, which was identified by DNA relatedness analysis. We then assessed the efficacy of granulocyte colony-stimulating factor (G-CSF) (30 to 100 microg/kg of body weight per day) and granulocyte-macrophage colony-stimulating factor (GM-CSF) (0.8 to 2 microg/kg x day). The administration of G-CSF either before or after infection improved the survival rate from less than 25% up to 100% (P < 0.05). The effects of G-CSF on organ clearance and histological examinations were most remarkable in the lungs. The levels of tumor necrosis factor alpha (TNF-alpha) in bronchoalveolar lavage fluid (BALF) of neutropenic and G-CSF-pretreated mice were 60 +/- 6 ng/ml and 18 +/- 6 pg/ml, respectively, at 24 h after infection. Immunohistologically, alveolar macrophages proved to be the main source of TNF-alpha in BALF. GM-CSF increased neutrophil counts less significantly than did G-CSF and increased the lethality (P < 0.05) with a high level of TNF-alpha in BALF. Expecting to inhibit TNF-alpha, we administered anti-TNF-alpha intraperitoneally at the dose completely inhibiting TNF-alpha in plasma (2 x 10(4) U), but the TNF-alpha level in BALF and the lethality increased. Though the number of neutrophils at the early stage of infection appeared to be the most critical, the results suggest that other host defense mechanisms, such as TNF-alpha overproduction in the lungs, have an important role in the prognosis of trichosporonosis.

Congenital familial myopathy with type 2 fiber hypoplasia and type 1 fiber predominance

A 12-month-old girl with delayed developmental milestones, due to muscle hypotonia and weakness from early infancy, exhibited type 2 fiber hypoplasia. A muscle biopsy specimen disclosed type 1 fiber predominance and type 2B fiber deficiency compatible with congenital myopathy. During the following 4 years, she continued to have mild muscle weakness, but no mental retardation. Her mother had similar symptoms from early infancy with minimal progression. Although type 2 fiber hypoplasia is a non-specific finding in various diseases, it may be a specific finding in a limited number of patients with hereditary congenital non-progressive myopathy.

Effects of pulmonary surfactant on macrophage migration: suppression of chemokinesis by surfactant phospholipid and enhancement of chemotaxis by surfactant protein

We fractionated the bronchoalveolar lavage fluid (BALF) from normal rabbit lungs into several fractions by high speed centrifugation and ethanol-ether extraction. Random migration, chemokinesis and chemotaxis of freshly harvested alveolar macrophages (AM), 24 h cultured AM, and peritoneal exudate cells (PEC) were assayed in vitro using a modified, under agarose method and a blind well chemotactic chamber method. Freshly harvested AM demonstrated little random migration compared with PEC. However, when freshly harvested AM were pre-incubated in surfactant free medium for 24 h, the cells showed the same rate of migration as PEC. The increased migration of the 24 h cultured AM was partially suppressed by the presence of all BALF fractions containing high proportions of phospholipid. The inhibition by Fr-L (a fraction enriched in phospholipids) was reversed by normal serum, but not by heat-inactivated serum, cholesterol, synthetic dipalmitoyl phosphatidyl choline, or indomethacin. Fr-L markedly suppressed macrophage chemokinesis but did not affect on macrophage chemotaxis. Alternatively, Fr-P, a delipidated preparation of surfactant consisting mainly of protein, had no effect on macrophage chemokinesis but increased the chemotaxis of PEC to zymosan-activated serum. We conclude that surfactant phospholipid suppresses AM migration, while surfactant protein increases macrophage chemotaxis.

Superoxide scavenging activity of erythromycin-iron complex

We evaluated superoxide (O2-.) scavenging activity of erythromycin (EM) and of EM-iron complex by means of electron spin resonance spectroscopy, luminol-dependent chemiluminescence assay, and cytochrome c reduction assay. The EM-iron complex was produced by mixing EM with equal molar iron chloride and was stable in neutral buffer. The EM-iron complex reduced the amount of O2-. produced by xanthine oxidase/hypoxanthine without inhibiting the enzyme activity. It also reduced the amount of O2-. release from phorbor ester-stimulated human neutrophils and alveolar macrophages. EM alone showed few such effects. The scavenging activity of the complex was equal to that of L-ascorbic acid. These results in vitro suggest a possibility that the O2-.-scavenging effect of EM-iron complex contributes to the anti-inflammatory action of EM used in treating chronic inflammatory lung disease independent of its antimicrobial activity.