History and future perspectives of adipose tissue macrophage biology

Macrophages contribute to adipose tissue homeostasis; however, they are also thought to be responsible for insulin resistance in obesity. Macrophages, which were oversimplified in past methodologies, have become rather difficult to understand comprehensively as recent developments in research methodology have revealed their diversity. This review highlights recent studies on adipose tissue macrophages, identifies controversial issues that need to be resolved and proposes a scenario for further development of adipose tissue macrophage biology.

Characterization of Diabetic Striatopathy With Repeated Follow-Up Using Multiple Imaging Studies

Diabetic striatopathy is a rare condition with a prevalence of less than one in 100,000. Herein, we report a case of diabetic striatopathy exacerbated by hyperglycemia and hypoglycemia, with repeated follow-up with multiple imaging studies. This case suggested that putamen neuronal loss and dysfunction, gliosis, and ischemia are associated with diabetic striatopathy pathophysiology. In addition, striatal hyperintensity on T1-weighted MRI images was more pronounced after symptom remission when evaluated several times over a short period. Therefore, clinicians should be aware that even if MRI findings are normal in the very early stages of the onset of diabetic striatopathy, repeating MRIs at intervals may reveal typical findings.

Isoxanthohumol improves obesity and glucose metabolism via inhibiting intestinal lipid absorption with a bloom of Akkermansia muciniphila in mice

OBJECTIVE

Polyphenols have health-promoting effects, such as improving insulin resistance. Isoxanthohumol (IX), a prenylated flavonoid found in beer hops, has been suggested to reduce obesity and insulin resistance; however, the mechanism remains unknown.

METHODS

High-fat diet-fed mice were administered IX. We analyzed glucose metabolism, gene expression profiles and histology of liver, epididymal adipose tissue and colon. Lipase activity, fecal lipid profiles and plasma metabolomic analysis were assessed. Fecal 16s rRNA sequencing was obtained and selected bacterial species were used for in vitro studies. Fecal microbiota transplantation and monocolonization were conducted to antibiotic-treated or germ-free (GF) mice.

RESULTS

The administration of IX lowered weight gain, decreased steatohepatitis and improved glucose metabolism. Mechanistically, IX inhibited pancreatic lipase activity and lipid absorption by decreasing the expression of the fatty acid transporter CD36 in the small intestine, which was confirmed by increased lipid excretion in feces. IX administration increased markers of intestinal barrier function, including thickening the mucin layer and increasing caludin-1, a tight-junction related protein in the colon. In contrast, the effects of IX were nullified by antibiotics. As revealed using 16S rRNA sequencing, the microbial community structure changed with a significant increase in the abundance of Akkermansia muciniphila in the IX-treated group. An anaerobic chamber study showed that IX selectively promoted the growth of A. muciniphila while exhibiting antimicrobial activity against some Bacteroides and Clostridium species. To further explore the direct effect of A. muciniphila on lipid and glucose metabolism, we monocolonized either A. muciniphila or Bacteroides thetaiotaomicron to GF mice. A. muciniphila monocolonization decreased CD36 expression in the jejunum and improved glucose metabolism, with decreased levels of multiple classes of fatty acids determined using plasma metabolomic analysis.

CONCLUSIONS

Our study demonstrated that IX prevents obesity and enhances glucose metabolism by inhibiting dietary fat absorption. This mechanism is linked to suppressing pancreatic lipase activity and shifts in microbial composition, notably an increase in A. muciniphila. These highlight new treatment strategies for preventing metabolic syndrome by boosting the gut microbiota with food components.

Heterogeneity of adipose tissue-resident macrophages-beyond M1/M2 paradigm

Adipose tissue-resident macrophages (ATMs) are reported to be important for maintaining adipose tissue remodeling and homeostasis. ATMs were classified for the first time in 2007 into the M1 and M2 types. This theory suggests that in the non-obese adipose tissue, the anti-inflammatory, alternatively activated macrophages (AAMs) predominate, and regulate tissue homeostasis, remodeling, and insulin sensitivity. On the other hand, classically activated M1-type macrophages increase rapidly in obesity, secrete inflammatory cytokines, such as TNFα and IL-6, and induce insulin resistance. In recent years, experimental findings that cannot be explained by this theory have been clarified one after another and the theory is being reconsidered. In this review, based on recent findings, we summarize reports on the novel metabolic regulatory functions of ATMs beyond the M1/M2 paradigm.

Depletion of CD206+ M2-like macrophages induces fibro-adipogenic progenitors activation and muscle regeneration

Muscle regeneration requires the coordination of muscle stem cells, mesenchymal fibro-adipogenic progenitors (FAPs), and macrophages. How macrophages regulate the paracrine secretion of FAPs during the recovery process remains elusive. Herein, we systemically investigated the communication between CD206⁺ M2-like macrophages and FAPs during the recovery process using a transgenic mouse model. Depletion of CD206⁺ M2-like macrophages or deletion of CD206⁺ M2-like macrophages-specific TGF-β1 gene induces myogenesis and muscle regeneration. We show that depletion of CD206⁺ M2-like macrophages activates FAPs and activated FAPs secrete follistatin, a promyogenic factor, thereby boosting the recovery process. Conversely, deletion of the FAP-specific follistatin gene results in impaired muscle stem cell function, enhanced fibrosis, and delayed muscle regeneration. Mechanistically, CD206⁺ M2-like macrophages inhibit the secretion of FAP-derived follistatin via TGF-β signaling. Here we show that CD206⁺ M2-like macrophages constitute a microenvironment for FAPs and may regulate the myogenic potential of muscle stem/satellite cells.

Astaxanthin, a Marine Carotenoid, Maintains the Tolerance and Integrity of Adipose Tissue and Contributes to Its Healthy Functions

Recently, obesity-induced insulin resistance, type 2 diabetes, and cardiovascular disease have become major social problems. We have previously shown that Astaxanthin (AX), which is a natural antioxidant, significantly ameliorates obesity-induced glucose intolerance and insulin resistance. It is well known that AX is a strong lipophilic antioxidant and has been shown to be beneficial for acute inflammation. However, the actual effects of AX on chronic inflammation in adipose tissue (AT) remain unclear. To observe the effects of AX on AT functions in obese mice, we fed six-week-old male C57BL/6J on high-fat-diet (HFD) supplemented with or without 0.02% of AX for 24 weeks. We determined the effect of AX at 10 and 24 weeks of HFD with or without AX on various parameters including insulin sensitivity, glucose tolerance, inflammation, and mitochondrial function in AT. We found that AX significantly reduced oxidative stress and macrophage infiltration into AT, as well as maintaining healthy AT function. Furthermore, AX prevented pathological AT remodeling probably caused by hypoxia in AT. Collectively, AX treatment exerted anti-inflammatory effects via its antioxidant activity in AT, maintained the vascular structure of AT and preserved the stem cells and progenitor's niche, and enhanced anti-inflammatory hypoxia induction factor-2α-dominant hypoxic response. Through these mechanisms of action, it prevented the pathological remodeling of AT and maintained its integrity.

Fate of adipocyte progenitors during adipogenesis in mice fed a high-fat diet

Objective

Expansion of adipose tissue during obesity through the recruitment of newly generated adipocytes (hyperplasia) is metabolically healthy, whereas that through the enlargement of pre-existing adipocytes (hypertrophy) leads to metabolic complications. Accumulating evidence from genetic fate mapping studies suggests that in animal models receiving a high-fat diet (HFD), only adipocyte progenitors (APs) in gonadal white adipose tissue (gWAT) have proliferative potential. However, the proliferative potential and differentiating capacity of APs in the inguinal WAT (iWAT) of male mice remains controversial. The objective of this study was to investigate the proliferative and adipogenic potential of APs in the iWAT of HFD-fed male mice.

Methods

We generated PDGFRα-GFP-Cre-ER^T2/tdTomato (KI/td) mice and traced PDGFRα-positive APs in male mice fed HFD for 8 weeks. We performed a comprehensive phenotypic analysis, including the histology, immunohistochemistry, flow cytometry, and gene expression analysis, of KI/td mice fed HFD.

Results

Contrary to the findings of others, we found an increased number of newly generated tdTomato⁺ adipocytes in the iWAT of male mice, which was smaller than that observed in the gWAT. We found that in male mice, the iWAT has more proliferating tdTomato⁺ APs than the gWAT. We also found that tdTomato⁺ APs showed a higher expression of Dpp4 and Pi16 than tdTomato⁻ APs, and the expression of these genes was significantly higher in the iWAT than in the gWAT of mice fed HFD for 8 weeks. Collectively, our results reveal that HFD feeding induces the proliferation of tdTomato⁺ APs in the iWAT of male mice.

Conclusion

In male mice, compared with gWAT, iWAT undergoes hyperplasia in response to 8 weeks of HFD feeding through the recruitment of newly generated adipocytes due to an abundance of APs with a high potential for proliferation and differentiation.

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High-fat diet (HFD) increases proliferative APs in iWAT of male mice.

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HFD promotes the recruitment of smaller adipocytes in the iWAT of male mice.

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iWAT expands by recruiting newly-generated adipocytes (hyperplasia) in male mice.

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gWAT expands by enlargement of pre-existing adipocytes (hypertrophy) in male mice.

Generation and characterization of a Meflin-CreERT2 transgenic line for lineage tracing in white adipose tissue

Meflin (Islr) expression has gained attention as a marker for mesenchymal stem cells, but its function remains largely unexplored. Here, we report the generation of Meflin-CreER^T2 mice with CreER^T2 inserted under the Meflin gene promoter to label Meflin-expressing cells genetically, thereby enabling their lineages to be traced. We found that in adult mice, Meflin-expressing lineage cells were present in adipose tissue stroma and had differentiated into mature adipocytes. These cells constituted Crown-like structures in the adipose tissue of mice after high-fat diet loading. Cold stimulation led to the differentiation of Meflin-expressing lineage cells into beige adipocytes. Thus, the Meflin-CreER^T2 mouse line is a useful new tool for visualizing and tracking the lineage of Meflin-expressing cells.

Astaxanthin stimulates mitochondrial biogenesis in insulin resistant muscle via activation of AMPK pathway

BACKGROUND

Skeletal muscle is mainly responsible for insulin-stimulated glucose disposal. Dysfunction in skeletal muscle metabolism especially during obesity contributes to the insulin resistance. Astaxanthin (AX), a natural antioxidant, has been shown to ameliorate hepatic insulin resistance in obese mice. However, its effects in skeletal muscle are poorly understood. The current study aimed to investigate the molecular target of AX in ameliorating skeletal muscle insulin resistance.

METHODS

We fed 6-week-old male C57BL/6J mice with normal chow (NC) or NC supplemented with AX (NC+AX) and high-fat-diet (HFD) or HFD supplemented with AX for 24 weeks. We determined the effect of AX on various parameters including insulin sensitivity, glucose uptake, inflammation, kinase signaling, gene expression, and mitochondrial function in muscle. We also determined energy metabolism in intact C2C12 cells treated with AX using the Seahorse XFe96 Extracellular Flux Analyzer and assessed the effect of AX on mitochondrial oxidative phosphorylation and mitochondrial biogenesis.

RESULTS

AX-treated HFD mice showed improved metabolic status with significant reduction in blood glucose, serum total triglycerides, and cholesterol (p< 0.05). AX-treated HFD mice also showed improved glucose metabolism by enhancing glucose incorporation into peripheral target tissues, such as the skeletal muscle, rather than by suppressing gluconeogenesis in the liver as shown by hyperinsulinemic-euglycemic clamp study. AX activated AMPK in the skeletal muscle of the HFD mice and upregulated the expressions of transcriptional factors and coactivator, thereby inducing mitochondrial remodeling, including increased mitochondrial oxidative phosphorylation component and free fatty acid metabolism. We also assessed the effects of AX on mitochondrial biogenesis in the siRNA-mediated AMPK-depleted C2C12 cells and showed that the effect of AX was lost in the genetically AMPK-depleted C2C12 cells. Collectively, AX treatment (i) significantly ameliorated insulin resistance and glucose intolerance through regulation of AMPK activation in the muscle, (ii) stimulated mitochondrial biogenesis in the muscle, (iii) enhanced exercise tolerance and exercise-induced fatty acid metabolism, and (iv) exerted antiinflammatory effects via its antioxidant activity in adipose tissue.

CONCLUSIONS

We concluded that AX treatment stimulated mitochondrial biogenesis and significantly ameliorated insulin resistance through activation of AMPK pathway in the skeletal muscle.

Peripheral PD1-positive CD4 T-Lymphocyte Count Can Predict Progression-free Survival in Patients With Non-small Cell Lung Cancer Receiving Immune Checkpoint Inhibitor

BACKGROUND/AIM

Little information is available about the association between peripheral T-lymphocyte expression of programmed cell death protein 1 (PD1) and the efficacy of immune checkpoint inhibitor therapy in patients with non-small cell lung cancer (NSCLC). We analyzed the PD1 and cytotoxic T-lymphocyte associated protein 4 (CTLA4) expression in peripheral blood T-lymphocytes of patients with NSCLC receiving immune checkpoint inhibitor therapy.

PATIENTS AND METHODS

Patients with NSCLC who were scheduled to receive treatment with immune checkpoint inhibitors were prospectively enrolled in this study between November 2017 and November 2018. Peripheral blood samples were obtained within 1 week before or after the initiation of treatment with an immune checkpoint inhibitor.

RESULTS

Flow cytometry was conducted in 19 patients. Patients were treated with nivolumab, pembrolizumab, or atezolizumab. The group with a high percentage of PD1⁺CD4⁺ T-lymphocytes relative to the total CD4⁺ T-lymphocyte count had a longer progression-free survival [median=6.0 (95% confidence intervaI=0.5-not estimated) months] than the group with a low percentage of PD1⁺CD4⁺ T-lymphocytes [median=1.1 (95% confidence intervaI=0.4-5.0) months; p=0.034, log-rank test]. However, no significant associations were detected with the percentages of CTLA4⁺CD4⁺, PD1⁺CD8⁺ or CTLA4⁺CD8⁺ T-lymphocytes in the peripheral blood.

CONCLUSION

A high percentage of peripheral CD4⁺PD1⁺ T-lymphocytes was associated with a longer progression-free survival in patients receiving treatment with an immune checkpoint inhibitor. The systemic immune system may have an influence on the efficacy of immune checkpoint inhibitor therapy in patients with NSCLC.

Macrophage-specific hypoxia-inducible factor-1α deletion suppresses the development of liver tumors in high-fat diet-fed obese and diabetic mice

AIMS/INTRODUCTION

Chronic inflammation of the liver is often observed with obesity or type 2 diabetes. In these pathological conditions, the immunological cells, such as macrophages, play important roles in the development or growth of liver cancer. Recently, it was reported that hypoxia-inducible factor-1α (HIF-1α) is a key molecule for the acquisition of inflammatory M1 polarity of macrophages. In the present study, we examined the effects of altered macrophage polarity on obesity- and diabetes-associated liver cancer using macrophage-specific HIF-1α knockout (KO) mice.

MATERIALS AND METHODS

To induce liver cancer in the mice, diethylnitrosamine, a chemical carcinogen, was used. Both KO mice and wild-type littermates were fed either a high-fat diet (HFD) or normal chow. They were mainly analyzed 6 months after HFD feeding.

RESULTS

Development of liver cancer after HFD feeding was 45% less in KO mice than in wild-type littermates mice. Phosphorylation of extracellular signal-regulated kinase 2 was also lower in the liver of KO mice. Those effects of HIF-1α deletion in macrophages were not observed in normal chow-fed mice. Furthermore, the size of liver tumors did not differ between KO and wild-type littermates mice, even those on a HFD. These results suggest that the activation of macrophage HIF-1α by HFD is involved not in the growth, but in the development of liver cancer with the enhanced oncogenic extracellular signal-regulated kinase 2 signaling in hepatocytes.

CONCLUSIONS

The activation of macrophage HIF-1α might play important roles in the development of liver cancer associated with diet-induced obesity and diabetes.

Linkage of CD8+ T cell exhaustion with high-fat diet-induced tumourigenesis

Obesity increases the risk of cancer. Increased levels of hormones (such as oestrogen, insulin, insulin-like growth factor, and leptin), free fatty acid-induced production of reactive oxygen species, an altered intestinal microbiome and chronic inflammation are known to be associated with an increased cancer risk in obese subjects. However, the mechanism underlying the connection between obesity and cancer development remains elusive. Here, we show that a high-fat diet (HFD) promotes tumour initiation/progression and induces a phenotypic switch from PD-1⁻ CD8⁺non-exhausted T cells to PD-1⁺ CD8⁺exhausted T cells in a murine breast cancer model. While PD-1⁻ CD8⁺non-exhausted T cells predominated in the mammary glands of normal diet (ND)-fed mice, PD-1⁺ CD8⁺exhausted T cells accumulated in the developing tumours of HFD-fed mice. Gene expression profiles indicated that PD-1⁺ CD8⁺ T cells expressed higher levels of the tumour-trophic gene Opn and lower levels of the cytotoxic genes Ifng and Gzmb than did PD-1⁻ CD8⁺ T cells. Our study provides a possible mechanistic linkage between obesity and cancer.

Partial depletion of CD206-positive M2-like macrophages induces proliferation of beige progenitors and enhances browning after cold stimulation

Beige adipocytes are an inducible form of thermogenic adipocytes that become interspersed within white adipose tissue (WAT) depots in response to cold exposure. Previous studies have shown that type 2 cytokines and M2 macrophages induce cold-induced browning in inguinal WAT (ingWAT) by producing catecholamines. Exactly how the conditional and partial depletion of CD206+ M2-like macrophages regulates the cold-induced browning of ingWAT, however, remains unknown. We examined the role of CD206+ M2-like macrophages in the cold-induced browning of WAT using genetically engineered CD206DTR mice, in which CD206+ M2-like macrophages were conditionally depleted. The partial depletion of CD206+ M2-like enhanced UCP1 expression in ingWAT, as shown by immunostaining, and also upregulated the expression of Ucp1 and other browning-related marker genes in ingWAT after cold exposure. A flow cytometry analysis showed that the partial depletion of CD206+ M2-like macrophages caused an increase in the number of beige progenitors in ingWAT in response to cold. Thus, we concluded that CD206+ M2-like macrophages inhibit the proliferation of beige progenitors and that the partial depletion of CD206+ M2-like macrophages releases this inhibition, thereby enhancing browning and insulin sensitivity.

Sirt1 activator induces proangiogenic genes in preadipocytes to rescue insulin resistance in diet-induced obese mice

Sirt1 plays an important role in regulating glucose and lipid metabolism in obese animal models. Impaired adipose tissue angiogenesis in the obese state decreases adipogenesis and thereby contributes to glucose intolerance and lipid metabolism. However, the mechanism by which Sirt1 activation affects obesity-associated impairments in angiogenesis in the adipose tissue is not fully understood. Here, we show that SRT1720 treatment induces angiogenic genes in cultured 3T3-L1 preadipocytes and ex vivo preadipocytes. siRNA-mediated knockdown of Sirt1 in 3T3-L1 preadipocytes downregulated angiogenic genes in the preadipocytes. SRT1720 treatment upregulated metabolically favorable genes and reduced inflammatory gene expressions in the adipose tissue of diet-induced obese (DIO) mice. Collectively, these findings suggest a novel role of SRT1720-induced Sirt1 activation in the induction of angiogenic genes in preadipocytes, thereby reducing inflammation and fibrosis in white adipose tissue (WAT) and promoting insulin sensitivity.

CD206+ M2-like macrophages regulate systemic glucose metabolism by inhibiting proliferation of adipocyte progenitors

Adipose tissue resident macrophages have important roles in the maintenance of tissue homeostasis and regulate insulin sensitivity for example by secreting pro-inflammatory or anti-inflammatory cytokines. Here, we show that M2-like macrophages in adipose tissue regulate systemic glucose homeostasis by inhibiting adipocyte progenitor proliferation via the CD206/TGFβ signaling pathway. We show that adipose tissue CD206⁺ cells are primarily M2-like macrophages, and ablation of CD206⁺ M2-like macrophages improves systemic insulin sensitivity, which was associated with an increased number of smaller adipocytes. Mice genetically engineered to have reduced numbers of CD206⁺ M2-like macrophages show a down-regulation of TGFβ signaling in adipose tissue, together with up-regulated proliferation and differentiation of adipocyte progenitors. Our findings indicate that CD206⁺ M2-like macrophages in adipose tissues create a microenvironment that inhibits growth and differentiation of adipocyte progenitors and, thereby, control adiposity and systemic insulin sensitivity.Adipose tissue contains macrophages that can influence both local and systemic metabolism via the secretion of cytokines. Here, Nawaz et al. report that M2-like macrophages, present in adipose tissue, create a microenvironment that inhibits proliferation of adipocyte progenitors due to the secretion of TGF-β1.

HIF-1α in Myeloid Cells Promotes Adipose Tissue Remodeling Toward Insulin Resistance

Adipose tissue hypoxia is an important feature of pathological adipose tissue expansion. Hypoxia-inducible factor-1α (HIF-1α) in adipocytes reportedly induces oxidative stress and fibrosis, rather than neoangiogenesis via vascular endothelial growth factor (VEGF)-A. We previously reported that macrophages in crown-like structures (CLSs) are both hypoxic and inflammatory. In the current study, we examined how macrophage HIF-1α is involved in high-fat diet (HFD)-induced inflammation, neovascularization, hypoxia, and insulin resistance using mice with myeloid cell-specific HIF-1α deletion that were fed an HFD. Myeloid cell-specific HIF-1α gene deletion protected against HFD-induced inflammation, CLS formation, poor vasculature development in the adipose tissue, and systemic insulin resistance. Despite a reduced expression of Vegfa in epididymal white adipose tissue (eWAT), the preadipocytes and endothelial cells of HIF-1α-deficient mice expressed higher levels of angiogenic factors, including Vegfa, Angpt1, Fgf1, and Fgf10 in accordance with preferable eWAT remodeling. Our in vitro study revealed that lipopolysaccharide-treated bone marrow-derived macrophages directly inhibited the expression of angiogenic factors in 3T3-L1 preadipocytes. Thus, macrophage HIF-1α is involved not only in the formation of CLSs, further enhancing the inflammatory responses, but also in the inhibition of neoangiogenesis in preadipocytes. We concluded that these two pathways contribute to the obesity-related physiology of pathological adipose tissue expansion, thus causing systemic insulin resistance.

Genetic diversity and the genetic structure of natural populations of Chamaecyparis obtusa: implications for management and conservation

We investigated 25 natural populations of Chamaecyparis obtusa using 51 cleaved amplified polymorphic sequence (CAPS) markers, which were developed using information on sequence-tagged sites (STS) in Cryptomeria japonica. Most CAPS markers have codominant expression patterns, and are suitable for population studies because of their robustness and convenience. We estimated various genetic diversity parameters, including average heterozygosity (H(e)) and allelic richness and found that the more peripheral populations tended to have lower genetic diversity than central populations, in agreement with a previous theoretical study. The overall genetic differentiation between populations was low, but statistically significant (G(ST)=0.039), and similar to the level reported in a previous allozyme study. We attempted to detect non-neutral loci associated with local adaptation to clarify the relationship between the fixation index (F(ST)) and H(e) values for each locus and found seven candidates non-neutral loci. Phylogenetic tree analysis of the populations and Bayesian clustering analysis revealed a pattern of gradually increasing isolation of populations with increasing geographical distance. Three populations had a high degree of linkage disequilibrium, which we attribute to severe bottlenecks due to human disturbance or competition with other species during their migration from refugia after the most recent glaciation. We concluded that the small populations in western Japan and in Kanto district are more important, from a conservation perspective, than the populations in central Japan, due to their genetic divergence, relatively small sizes and restricted areas.

Quasi-solid dye sensitised solar cells filled with ionic liquid—increase in efficiencies by specific interaction between conductive polymers and gelators

Photo-energy conversions for quasi-solid dye sensitised solar cells increased when gel electrolytes were combined with conductive polymers as counter electrodes and the conversion surpassed that for DSSCs equipped with conventional Pt counter electrodes.

Dosimetric predictors of radiation esophagitis in patients treated for non-small-cell lung cancer with carboplatin/paclitaxel/radiotherapy

PURPOSE

To establish dosimetric predictors of radiation esophagitis (RE) in patients treated with a combination of carboplatin, paclitaxel, and radiotherapy.

METHODS AND MATERIALS

Three-dimensional radiotherapy plans of 26 patients with non-small-cell lung cancer who received 50-60 Gy of radiotherapy concurrently with weekly administration of carboplatin (AUC 2) and paclitaxel (40-45 mg/m(2)) were reviewed in conjunction with RE. The factors analyzed included the following: percentages of organ volumes receiving >40 Gy (V40), >45 Gy (V45), >50 Gy (V50), and >55 Gy (V55); the length of esophagus (total circumference) treated with >40 Gy (LETT40), >45 Gy (LETT45), >50 Gy (LETT50), and >55 Gy (LETT55); the maximum dose in the esophagus (Dmax); and the mean dose in the esophagus (Dmean). Data were obtained on the basis of superposition algorithm.

RESULTS

All factors except Dmax showed statistical correlation with RE. Good correlations were shown between RE and LETT45 (rho = 0.714) and V45 (rho = 0.686).

CONCLUSIONS

LETT45 and V45 appear to be useful dosimetric predictors of RE. It is also suggested that Dmax does not predict RE.

Features of IgA nephropathy in preschool children

AIM

The aim of this study is to clarify the age-related characteristics of pediatric IgA nephropathy.

PATIENTS AND METHODS

Five cases in preschool children less than 6 years old were analyzed and compared to 38 cases in older children from 6 to 15 years old.

RESULTS

The group of younger children had higher incidences of gross hematuria, hypertension, proteinuria, and hypoproteinemia. Renal biopsy specimens in this group showed more intracapillary lesions including mesangial cell proliferation and endocapillary proliferation ofglomeruli, but less segmental lesions, global sclerosis, and interstitial changes.

CONCLUSION

IgA nephritis in preschool children demonstrated more symptoms of acute onset and less chronic renal injury.

[Psychiatric studies of chemotherapy and chemotherapy-induced nausea and vomiting of patients with lung or thymic cancer]

Psychiatric studies were made on 26 inoperable patients with lung cancer or thymic cancer to exam the possible correlation of chemotherapy and chemotherapy-induced nausea and vomiting. All patients were informed of their disease and how to undergo the therapy. Psychiatric tests of CMI (Cornell Medical, Index), MAS (Manifest Anxiety Scale), SDS (Self-Rating Depression Scale) and QOL questionnaire were performed just before the chemotherapy. SDS and QOL questionnaire were also done after chemotherapy. The patients were given chemotherapy including CDDP (80 mg/m2) and anti-emetic agents of 30 mg of azasetron, 750 mg of methylprednisolone and 1,800 mg of domperidone. The patients showing neurosis, anxiety or depression had significantly high nausea scores, so we concluded that psychiatric support was needed to improve these patients' QOL in chemotherapy.

[Two patients with mediastinal parathyroid cysts]

We encountered two patients with mediastinal parathyroid cysts. Patients 1 was a 44-year-old man with no complaints who had an abnormal shadow on a roentgenogram of the chest. An iperation was performed because a computed tomogram and a magnetic resonance image showed a cyst in the upper right part of the mediastinum, which was suspected to be a mediastinal thyroid cyst. Patient 2 was a 77-year-old woman with no complaints who had an abnormal shadow on a roentgenogram of the chest. Therapeutic thoracoscopy was performed because a mediastinal cyst was suspected based on the results of computed tomography and magnetic resonance image. Both patients had thin-walled that they were mediastinal parathyroid cysts. Mediastinal parathyroid cysts are very rare. We searched the medical literature but found previously published reports of only 39 cases.

[A case of UIP with autoimmune hemolytic anemia]

A 70-year-old male was admitted because of cough and sputum. Chest X-ray showed bilateral interstitial shadows, and usual interstitial pneumonitis was diagnosed by TBLB and BAL. He was followed without medication. The dyspnea increased and the abnormal shadow spread on chest X-ray. Autoimmune hemolytic anemia was newly diagnosed because the RBC count was 195 x 10(4)/mm3, Hb was 8.6 g/dl, and direct Coombs test and warm antibody were positive. In this case, there appears to be a relationship between deterioration of interstitial pneumonia and the on-set of autoimmune hemolytic anemia.

Studies of a key protein in the mechanism of the excitation-contraction coupling process of frog skeletal muscle, using phenylglyoxal

The excitation-contraction (E-C) coupling process in single twitch fibres from frog toe muscle was inhibited selectively by phenylglyoxal (PGO), a specific guanidyl modifying reagent. A new protein (31.5 kDa), which has PGO-binding ability and seems to play a key role in the E-C coupling process, was solubilized from transverse tubule membrane-junctional sarcoplasmic reticulum complexes (TTM-JSR) of frog skeletal muscles, using 14C-PGO. The monoclonal antibody against this protein applied extracellularly inhibited the E-C coupling process of the single fibres. This protein appears to constitute the very first step of input for E-C coupling. It is considered to behave as an indispensable part of an 'electrometer' to measure membrane potentials. Therefore, the name 'electrometrin' is suggested for the new protein.

Solubilization, physiological role, and localization of a key protein (31.5 kD) to excitation-contraction coupling process of frog skeletal muscle cells, using phenylglyoxal

A new phenylglyoxal-binding protein (31.5 kD) was solubilized from frog skeletal muscle. The monoclonal AB against the 31.5 kD protein inhibited extracellularly E-C coupling process of single-muscle fibers.

Physiological role and localization of the new ouabain receptor protein (31.5 kD) from cat cardiac muscles, using the monoclonal AB against the protein

Role and localization of the new ouabain receptor protein (31.5 kD) were studied by using its monoclonal AB. The protein may be a key protein in the E-C coupling process in the cat cardiac muscle.

Improvement of severe heart failure with corticosteroid therapy in a patient with myocardial sarcoidosis

A patient presented with severe heart failure due to myocardial sarcoidosis. Sarcoidosis was diagnosed by biopsy of the skin and uptake of gallium-67 in the heart. We treated the patient with corticosteroids and succeeded in improving her condition. We assume that this was a rare case in which severe heart failure improved following with steroid therapy.

[Small sized non-small cell lung cancer in advanced stage]

Eighteen cases of non-small cell, small sized advanced lung cancer, out of 362 operated cases for 6 years excluding 7 cases of small cell lung cancer, 60 of preoperative treated and 27 of inoperable cases, were discussed. A small sized tumor was defined as a tumor within 8,000 mm3 in its volume, calculated by multipling three lengths measured on the resected specimens. There were fourteen cases with stage 3 and 4 (A), and four cases with N1 disease (B). In group A, three cases of twelve with N2 diseases showed the tiny skipping lesion in the mediastinum with negative regional nodes. Remaining two had a lesion of dissemination and pulmonary metastasis. In group B, they showed unusual way of N1 spread, in which two of them with left upper lobectomy had metastatic lymph nodes on the non-bearing lobe, the lower lobe, and other two cases took regional lymph nodes metastasis without invasive growth of the main tumor. Predominant histologic type was adenocarcinoma, but the subtype and the differentiation of it were not specific. The level of CEA was low below 5 ng/dl in most of them except three cases, in which it suggested massive positive nodes and pulmonary metastasis. Seven patients died of the disease in two years. Remainders are alive, 4 with and 7 free from the tumor with the longest period of 3 years and a half. N2 diseases of small sized tumor were found in the cases with the volume of 3 cm3 and more at almost same ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Hematoma of the interatrial septum associated with complete atrioventricular block

A 70-year-old man who had been treated for tongue cancer began to suffer from repeated syncopal attacks. His electrocardiogram indicated complete atrioventricular block. A permanent pacemaker was implanted. He was well for about 2 years after which time he developed dyspnea, suffered from general fatigue, and then suddenly died. A postmortem examination revealed a hematoma approximately 4 x 4. cm in size in the interatrial septum, connected to a noncoronary sinus and rupture of the noncoronary leaflet, which compressed the tricuspid and aortic valves. This hematoma might have been related to the conduction disturbance caused by destructive compression on the conduction system, and his death by the rupture of the noncoronary leaflet.

Time lag between pulmonary congestion and pulmonary edema in dogs

The time course of pulmonary congestion and pulmonary edema was examined using a gravimetric method in 19 open-chest anesthetized dogs. Balloon catheters in the left atrium (LA) were inflated to elevate LA pressure more than 25 mmHg. The dogs were divided into 4 groups (G) according to the duration of the elevated LA pressure: G.1 (n = 6) as control; G.2 (n = 4) for 15 minutes; G.3 (n = 4) for 30 minutes; and G.4 (n = 5) for 60 minutes. Although no significant increase of extravascular lung water content (an indicator of pulmonary edema) was observed in G.2 (4.97 +/- 0.85 g/kg) and G.3 (4.46 +/- 0.96) compared with G.1 (4.02 +/- 0.88), a significant increase was observed in G.4 (6.81 +/- 1.21, p less than 0.05). Residual pulmonary blood content (an indicator of pulmonary congestion) was significantly increased in G.2, 3 and 4 compared with G.1. By light and electron microscopes, pulmonary congestion was revealed in G.2, whereas interstitial pulmonary edema was demonstrated only in G.4. Thus, it was concluded that pulmonary congestion occurred within 15 minutes, but pulmonary edema occurred 30 to 60 minutes after left atrial pressure was elevated more than 25 mmHg. This time lag may be an important factor in explaining the discrepancy between the elevated left atrial pressure and the clinical manifestation of pulmonary edema.

Mixed connective tissue disease with fatal pulmonary hypertension and a review of literature

The paper presents an autopsy case of mixed connective tissue disease (MCTD) with pulmonary hypertension (PH) and a review of literature. A 33-year-old woman with Raynaud's phenomenon and dyspnea of one year duration was diagnosed as having MCTD on the basis of a higher titer (1:163,840) of serum antibodies to the ribonucleoprotein (RNP). Cardiac catheterization showed complicating PH, confirmed an autopsy by the findings of concentric intimal cellular proliferation and typical plexiform lesions in the small arteries and arterioles of the lung, suggesting primary PH. Fatal PH with MCTD has been reported only 6 cases in literature including our case. All were young females, with histopathological findings consistent with plexogenic pulmonary arteriopathy in 5 cases and with recurrent pulmonary thromboembolism in the other. The aetiology of PH is still unknown, but it may be due to vasoconstriction evoked by the hyper-reactivity of the vessels.