Case Report: MYH9-related disease caused by Ala44Pro mutation in a child with a previous diagnosis of chronic immune thrombocytopenia.

MYH9-related disease, a rare autosomal dominant platelet disorder characterized by thrombocytopenia, giant platelets, and leukocyte inclusion bodies, may mimic immune thrombocytopenia in children unless suspected and carefully excluded. Here, we present a case involving a three-year-old girl with mild bleeding symptoms since infancy, previously diagnosed with chronic immune thrombocytopenia. The patient exhibited isolated thrombocytopenia and lacked any family history of thrombocytopenia, hearing impairment, or renal failure. Examination of peripheral blood smears via light microscopy revealed significant platelet macrocytosis with giant platelets and basophilic Döhle-like bodies in the neutrophils. Subsequent sequencing analysis of MYH9 gene identified a p.Ala44Pro mutation. Throughout a six-year follow-up period, the patient's condition remained stable. Our report underscores the significance of identifying leukocyte inclusion bodies in peripheral blood smears and considering MYH9-related diseases, even in instances of chronic macrothrombocytopenia devoid of familial history or non-hematological manifestations.

All-trans retinoic acid induces lipophagy through the activation of the AMPK-Beclin1 signaling pathway and reduces Rubicon expression in adipocytes.

Lipophagy is defined as a lipolysis pathway that degrades lipid droplet (LD) via autophagy. All-trans retinoic acid (atRA), a metabolite of vitamin A, stimulates lipolysis through hormone-sensitive lipase and ß-oxidation. However, the regulation of lipolysis by atRA-induced autophagy in adipocytes remains unclear. In this study, we investigated the effect of atRA on autophagy in epididymal fat of mice and the molecular mechanisms of autophagy in 3T3-L1 adipocytes. Western blotting showed that atRA decreased the expression of p62, a cargo receptor for autophagic degradation, and increased the expression of the lipidated LC3B (LC3B-II), an autophagy marker, in epididymal fat. Next, we confirmed that atRA increased autophagic flux in differentiated 3T3-L1 cells using the GFP-LC3-RFP-LC3ΔG probe. Immunofluorescent staining revealed that the colocalization of LC3B with perilipin increased in differentiated 3T3-L1 cells treated with atRA. The knockdown of Atg5, an essential gene in autophagy induction, partly suppressed the atRA-induced release of non-esterified fatty acid (NEFA) from LDs in differentiated 3T3-L1 cells. atRA time-dependently elicited the phosphorylation of AMPK and Beclin1, autophagy-inducing factors, in mature 3T3-L1 adipocytes. Inversely, atRA decreased the protein expression of Rubicon, an autophagy repressor, in differentiated 3T3-L1 cells and epididymal fat. Interestingly, the expression of ALDH1A1, atRA-synthesizing enzymes, increased in epididymal fat with decreased protein expression of Rubicon in aged mice. These results suggest that atRA may partially induce lipolysis through lipophagy by activating the AMPK-Beclin1 signaling pathway in the adipocytes and increased atRA levels may contribute to decreased Rubicon expression in the epididymal fat of aged mice. (248/250 words).

Elevated luminal inorganic phosphate suppresses intestinal Zn absorption in 5/6 nephrectomized rats.

Zinc (Zn) is an essential trace element in various biological processes. Chronic kidney disease (CKD) often leads to hypozincemia, resulting in further progression of CKD. In CKD, intestinal Zn absorption, the main regulator of systemic Zn metabolism, is often impaired; however, the mechanism underlying Zn malabsorption remains unclear. Here, we evaluated intestinal Zn absorption capacity in a rat model of CKD induced by 5/6 nephrectomy (5/6 Nx). Rats were given Zn and the incremental area under the plasma Zn concentration-time curve (iAUC) was measured as well as the expression of ZIP4, an intestinal Zn transporter. We found that 5/6 Nx rats showed lower iAUC than sham-operated rats, but expression of ZIP4 protein was upregulated. We therefore focused on other Zn absorption regulators to explore the mechanism by which Zn absorption was substantially decreased. Because some phosphate compounds inhibit Zn absorption by coprecipitation and hyperphosphatemia is a common symptom in advanced CKD, we measured inorganic phosphate (Pi) levels. Pi was elevated in not only serum but also the intestinal lumen of 5/6 Nx rats. Furthermore, intestinal intraluminal Pi administration decreased the iAUC in a dose-dependent manner in normal rats. In vitro, increased Pi concentration decreased Zn solubility under physiological conditions. Furthermore, dietary Pi restriction ameliorated hypozincemia in 5/6 Nx rats. We conclude that hyperphosphatemia or excess Pi intake is a factor in Zn malabsorption and hypozincemia in CKD. Appropriate management of hyperphosphatemia will be useful for prevention and treatment of hypozincemia in patients with CKD.NEW & NOTEWORTHY We demonstrated that elevated intestinal luminal Pi concentration can suppress intestinal Zn absorption activity without decreasing the expression of the associated Zn transporter. Increased intestinal luminal Pi led to the formation of an insoluble complex with Zn while dietary Pi restriction or administration of a Pi binder ameliorated hypozincemia in chronic kidney disease model rats. Therefore, modulation of dietary Pi by Pi restriction or a Pi binder might be useful for the treatment of hypozincemia and hyperphosphatemia.

Humoral and cellular factors inhibit phosphate-induced vascular calcification during the growth period.

Hyperphosphatemia is an independent and non-classical risk factor of cardiovascular disease and mortality in patients with chronic kidney disease (CKD). Increased levels of extracellular inorganic phosphate (Pi) are known to directly induce vascular calcification, but the detailed underlying mechanism has not been clarified. Although serum Pi levels during the growth period are as high as those observed in hyperphosphatemia in adult CKD, vascular calcification does not usually occur during growth. Here, we have examined whether the defence system against Pi-induced vascular calcification can exist during the growth period using mice model. We found that calcification propensity of young serum (aged 3 weeks) was significantly lower than that of adult serum (10 months), possibly due to high fetuin-A levels. In addition, when the aorta was cultured in high Pi medium in vitro, obvious calcification was observed in the adult aorta but not in the young aorta. Furthermore, culture in high Pi medium increased the mRNA level of tissue-nonspecific alkaline phosphatase (TNAP), which degrades pyrophosphate, only in the adult aorta. Collectively, our findings indicate that the aorta in growing mouse may be resistant to Pi-induced vascular calcification via a mechanism in which high serum fetuin-A levels and suppressed TNAP expression.

All-trans retinoic acid changes muscle fiber type via increasing GADD34 dependent on MAPK signal.

All-trans retinoic acid (ATRA) increases the sensitivity to unfolded protein response in differentiating leukemic blasts. The downstream transcriptional factor of PERK, a major arm of unfolded protein response, regulates muscle differentiation. However, the role of growth arrest and DNA damage-inducible protein 34 (GADD34), one of the downstream factors of PERK, and the effects of ATRA on GADD34 expression in muscle remain unclear. In this study, we identified ATRA increased the GADD34 expression independent of the PERK signal in the gastrocnemius muscle of mice. ATRA up-regulated GADD34 expression through the transcriptional activation of GADD34 gene via inhibiting the interaction of homeobox Six1 and transcription co-repressor TLE3 with the MEF3-binding site on the GADD34 gene promoter in skeletal muscle. ATRA also inhibited the interaction of TTP, which induces mRNA degradation, with AU-rich element on GADD34 mRNA via p-38 MAPK, resulting in the instability of GADD34 mRNA. Overexpressed GADD34 in C2C12 cells changes the type of myosin heavy chain in myotubes. These results suggest ATRA increases GADD34 expression via transcriptional and post-transcriptional regulation, which changes muscle fiber type.

Changes of cancer diagnosis disclosure to children in Japan in the last 20 years.

BACKGROUND: The practice of cancer diagnosis disclosure to children has been changed with the times. The regulations of clinical trials in the 2000s might change the practice in Japan. However, the perspective of this topic among children and adults has not been investigated in detail. METHODS: We studied changes in the practice of information sharing with children with cancer at pediatric cancer centers and the perspective of cancer diagnosis disclosure to children among school children, their parents and pediatric oncologists in the last 20 years by comparing the results of questionnaire surveys conducted in 1998, 2008 and 2018. RESULTS: This study revealed that the performing rate has increased with the times, but the institutions actively performing for children aged 7-9 years were 36.4% even in the 2018 survey. More than 70% of children wished diagnosis disclosure if they suffer from cancer in the series of surveys, while the ratio of parents who tell cancer diagnosis to their children hovered at 34.5 to 53.7% (p < 0.001 in all surveys). The ratio of pediatric oncologists having the policy to perform diagnosis disclosure proactively increased from 9.3 to 60.0%, while that of parents having the same policy stayed at 5.3% even in 2018. CONCLUSIONS: The performing rate of information sharing with children with cancer was significantly changed in the last 20 years. The opinion gaps were observed between parents and children and between parents and pediatric oncologists.

Change in children's perception of cancer in the last 10 years in Japan.

BACKGROUND: Social awareness of cancer can be changed with cancer education and proper distribution of cancer information. This study addressed the current situation and historical changes to children's perception of cancer. METHODS: Questionnaire surveys were conducted among healthy school children aged 10-15 years in 2008 and 2018. Knowledge of cancer was surveyed and compared with that of asthma, tuberculosis, and measles. The children were asked about their health information resources. RESULTS: The numbers of participants and collection rates were 438 and 63.9% in 2008, and 320 and 44.7% in 2018. Children's perception of cancer changed significantly in the last decade. The proportion of respondents answering "cancer affects children" changed from 78.3 to 89.5% (P = 0.0001), "cancer is preventable" from 42.0 to 49.7% (P = 0.0425), and "cancer is curable," from 52.4 to 66.0% (P = 0.0003). Significantly more junior high school students answered that cancer is preventable than elementary school children in 2018 (55.9 vs 42.7%, P = 0.0028). The major resources of information on health were television, parents, and books. The proportion of children choosing the Internet significantly increased from 15.3 to 47.8% (P < 0.0001). Significantly more junior high school students selected television and the Internet than elementary school children (94.5 vs 86.9%, P = 0.0202 for television; 57.1 vs 37.9%, P = 0.0007 for the Internet). CONCLUSIONS: The proportion of children correctly perceiving cancer information had increased in the last decade. Junior high school students better understood the information. The Internet is of increasing importance as an information resource for school children.

Close interaction with bone marrow mesenchymal stromal cells induces the development of cancer stem cell-like immunophenotype in B cell precursor acute lymphoblastic leukemia cells.

Minimal residual disease of leukemia may reside in the bone marrow (BM) microenvironment and escape the effects of chemotherapeutic agents. This study investigated interactions between B cell precursor (BCP)-acute lymphoblastic leukemia (ALL) cells and BM mesenchymal stromal cells (BM-MSCs) in vitro. Five BCP-ALL cell lines established from pediatric patients and primary samples from a BCP-ALL patient were examined by flow cytometry and immunocytochemistry for expression of specific cell surface markers and cell adhesion proteins. The cell lines developed chemoresistance to commonly used anti-leukemic agents through adhesion to MSC-TERT cells in long-term culture. The change in chemosensitivity after adhering to BM-MSCs was associated with the expression of CD34, CD133, P-glycoprotein and BCRP/ABCG2, and downregulation of CD38. Similar phenotypic changes were observed in primary samples obtained by marrow aspiration or biopsy from a BCP-ALL patient. BM-MSC-adhering leukemia cells also showed deceleration of cell proliferation and expressed proteins in the Cadherin and Integrin pathways. These results suggest that BCP-ALL cells residing in the BM microenvironment may acquire chemoresistance by altering their phenotype to resemble that of cancer stem cells. Our results indicate that cell adhesion could be potentially targeted to improve the chemosensitivity of residual BCP-ALL cells in the BM microenvironment.

Chronic polyarthritis as the first manifestation of childhood systemic polyarteritis nodosa.

Arthritis has been reported as an acute pattern, generally evanescent with oligoarthritis, mostly affecting knees and ankles in childhood systemic polyarteritis nodosa. However, chronic polyarthritis with morning stiffness mimicking juvenile idiopathic arthritis has not been reported. We describe the case of a 4-year old girl who had additive and chronic polyarthritis with edema, tenderness, pain on motion and morning stiffness for 2 months. After 45 days, she also presented painful subcutaneous nodules and erythematous-violaceous lesions in the extensor region of upper and lower limbs. She was admitted to university hospital due to high fever, malaise, myalgia, anorexia, loss of weight (1kg), painful skin lesions and severe functional disability. She was bedridden by chronic polyarthritis with limitation on motion. Systolic and diastolic blood pressures were greater than 95th percentile for height. Urine protein/creatinine ratio was 0.39g/day, and immunological tests were negative. Anti-streptolysin O was 1,687UI/mL. Skin biopsy revealed necrotizing vasculitis in medium- and small-sized vessels compatible with polyarteritis nodosa. Therefore, we had the diagnosis of systemic polyarteritis nodosa. Prednisone 2mg/kg/day was administered with complete resolution of skin lesions and arthritis, and improvement of proteinuria (0.26g/day) after 15 days. The diagnosis of childhood systemic polyarteritis nodosa should be considered for patients with chronic polyarthritis associated to cutaneous vasculitis triggered by streptococcal infection. RESUMO Na poliarterite nodosa sistêmica pediátrica, a artrite caracteriza-se pelo padrão agudo, geralmente evanescente, com oligoartrite, e afeta principalmente joelhos e tornozelos. No entanto, a poliartrite crônica com rigidez matinal e simulando artrite idiopática juvenil ainda não foi relatada. Descrevemos o caso de uma menina de 4 anos que apresentou poliartrite crônica aditiva com edema, dor à palpação e movimento, e rigidez matinal por 2 meses. Após 45 dias, também apresentou nódulos subcutâneos dolorosos e lesões eritêmato-violáceas na região extensora dos membros superiores e inferiores. Foi internada no hospital universitário por conta de febre alta, mal-estar, mialgia, anorexia, perda de peso (1kg), lesões de pele muito dolorosas e incapacidade funcional grave. Estava restrita ao leito devido à poliartrite crônica com limitação do movimento. Pressões sistólica e diastólica foram maiores que percentil 95 para altura. Relação proteína/creatinina urinária estava 0,39g/dia, e os testes imunológicos foram negativos. Antiestreptolisina O era 1.687UI/mL. A biópsia de pele revelou vasculite necrosante de vasos de pequeno e médio calibre, compatível com poliarterite nodosa. Portanto, foi realizado o diagnóstico de poliarterite nodosa sistêmica. Foi administrada prednisona 2mg/kg/dia com resolução completa das lesões de pele e da artrite, além de melhora da proteinúria (0,26g/dia) após 15 dias. O diagnóstico de poliarterite nodosa sistêmica pediátrica deve ser considerado em pacientes com poliartrite crônica associado a lesões cutâneas vasculíticas, sendo a infecção estreptocócica um importante fator desencadeante.

Chronic polyarthritis as the first manifestation of childhood systemic polyarteritis nodosa / Poliartrite crônica como primeira manifestação de poliarterite nodosa sistêmica pediátrica

ABSTRACT Arthritis has been reported as an acute pattern, generally evanescent with oligoarthritis, mostly affecting knees and ankles in childhood systemic polyarteritis nodosa. However, chronic polyarthritis with morning stiffness mimicking juvenile idiopathic arthritis has not been reported. We describe the case of a 4-year old girl who had additive and chronic polyarthritis with edema, tenderness, pain on motion and morning stiffness for 2 months. After 45 days, she also presented painful subcutaneous nodules and erythematous-violaceous lesions in the extensor region of upper and lower limbs. She was admitted to university hospital due to high fever, malaise, myalgia, anorexia, loss of weight (1kg), painful skin lesions and severe functional disability. She was bedridden by chronic polyarthritis with limitation on motion. Systolic and diastolic blood pressures were greater than 95th percentile for height. Urine protein/creatinine ratio was 0.39g/day, and immunological tests were negative. Anti-streptolysin O was 1,687UI/mL. Skin biopsy revealed necrotizing vasculitis in medium- and small-sized vessels compatible with polyarteritis nodosa. Therefore, we had the diagnosis of systemic polyarteritis nodosa. Prednisone 2mg/kg/day was administered with complete resolution of skin lesions and arthritis, and improvement of proteinuria (0.26g/day) after 15 days. The diagnosis of childhood systemic polyarteritis nodosa should be considered for patients with chronic polyarthritis associated to cutaneous vasculitis triggered by streptococcal infection.

RESUMO Na poliarterite nodosa sistêmica pediátrica, a artrite caracteriza-se pelo padrão agudo, geralmente evanescente, com oligoartrite, e afeta principalmente joelhos e tornozelos. No entanto, a poliartrite crônica com rigidez matinal e simulando artrite idiopática juvenil ainda não foi relatada. Descrevemos o caso de uma menina de 4 anos que apresentou poliartrite crônica aditiva com edema, dor à palpação e movimento, e rigidez matinal por 2 meses. Após 45 dias, também apresentou nódulos subcutâneos dolorosos e lesões eritêmato-violáceas na região extensora dos membros superiores e inferiores. Foi internada no hospital universitário por conta de febre alta, mal-estar, mialgia, anorexia, perda de peso (1kg), lesões de pele muito dolorosas e incapacidade funcional grave. Estava restrita ao leito devido à poliartrite crônica com limitação do movimento. Pressões sistólica e diastólica foram maiores que percentil 95 para altura. Relação proteína/creatinina urinária estava 0,39g/dia, e os testes imunológicos foram negativos. Antiestreptolisina O era 1.687UI/mL. A biópsia de pele revelou vasculite necrosante de vasos de pequeno e médio calibre, compatível com poliarterite nodosa. Portanto, foi realizado o diagnóstico de poliarterite nodosa sistêmica. Foi administrada prednisona 2mg/kg/dia com resolução completa das lesões de pele e da artrite, além de melhora da proteinúria (0,26g/dia) após 15 dias. O diagnóstico de poliarterite nodosa sistêmica pediátrica deve ser considerado em pacientes com poliartrite crônica associado a lesões cutâneas vasculíticas, sendo a infecção estreptocócica um importante fator desencadeante.

Haptic interface protocol for FEM-based deformable model and effects on fineness of force feedback and perceived hardness.

The remote haptic collaboration system between operating and assistant surgeons causes both shift and step delays of force feedback, and then makes users feel coarse reaction forces and different hardness of the object. In this study, we propose a haptic interface protocol for finite-element-method based deformable objects, in order to achieve a high update rate of force calculation. The method exports the necessary information for calculation of reaction forces from the simulation loop to the haptic loop. The experimental results indicated that the proposed method improved the fineness of force feedback and subjective hardness significantly.