Effect of diazoxide on a cat with insulinoma.

Case summary: The patient was a castrated male American Shorthair cat, approximately 14 years old, weighing 3.4 kg. The patient had chronic kidney disease (CKD) (International Renal Interest Society stages 3-4) as an underlying disease. The cat was examined at a hospital for intermittent lethargy and seizures. Hypoglycaemia was repeatedly observed, and the insulin level was 1.78 ng/ml (reference interval 0.27-0.69) when the blood glucose was 49 mg/dl. Although the cat was tentatively diagnosed with insulinoma, surgery was not recommended because of the severe CKD. Although frequent feeding and prednisolone treatment were initially attempted, blood glucose decreased to 24-42 mg/dl. Diazoxide was additionally prescribed at a dose of 5.2 mg/kg q12h. The cat's clinical signs improved, and the blood glucose was in the range of 75-103 mg/dl during the first 2 months. It was maintained at >50 mg/dl until the patient died of renal failure 161 days after the start of diazoxide treatment. With regard to adverse events, vomiting once every 2-3 days without weight loss and non-regenerative anaemia were observed, which might have been at least partially caused by diazoxide treatment. An insulinoma was definitively diagnosed via pathological autopsy. Relevance and novel information: This is the first reported case of long-term treatment with diazoxide in a cat with insulinoma. Since it was effective in situations where conventional therapies were unsuccessful, diazoxide could be useful as a new therapeutic option for cats with insulinoma. Since adverse events, such as progression of vomiting frequency and non-regenerative anaemia, were observed, careful monitoring was required during administration.

Association of Isolated Hypothyroxinemia and Subclinical Hypothyroidism With Birthweight: A Cohort Study in Japan.

Context: Isolated hypothyroxinemia (low maternal free thyroxine [FT4] in the absence of thyroid-stimulating hormone [TSH] elevation) and subclinical hypothyroidism (high TSH in the absence of FT4 elevation) during early pregnancy are common. However, there are limited data regarding pregnancy outcomes, particularly their association with birthweight. Objective: We assessed the association between isolated hypothyroxinemia and subclinical hypothyroidism during the first trimester and birthweight. Methods: Analyses were conducted using a database of pregnant women (n = 1105; median age, 35 years) who delivered at the National Center for Child Health and Development, a tertiary hospital in Tokyo. The primary outcomes included the rates of small for gestational age (SGA), large for gestational age (LGA), and low birth weight. Results: Of the 1105 pregnant women, 981 were classified into the euthyroidism group, 25 into the isolated hypothyroxinemia group, and 26 into the subclinical hypothyroidism group during the first trimester. The prevalence of SGA was significantly higher in isolated hypothyroxinemia and subclinical hypothyroidism groups than the euthyroidism group (28.0% and 19.2%, respectively, vs 5.7%; P < .01). The odds ratio with 95% CI for SGA was 12.51 (4.41-35.53) for isolated hypothyroxinemia and 4.44 (1.57-12.56) for subclinical hypothyroidism in a multivariable adjustment model. Isolated hypothyroxinemia and subclinical hypothyroidism were not significantly associated with LGA and low birth weight. Conclusion: Pregnant women with isolated hypothyroxinemia and subclinical hypothyroidism in the first trimester have an increased likelihood of SGA. Screening and careful perinatal checkups for isolated hypothyroxinemia and subclinical hypothyroidism may help identify pregnant women at high risk for SGA.

Dasatinib attenuates airway inflammation of asthma exacerbation in mice induced by house dust mites and dsRNA.

Asthma exacerbation is a significant clinical problem that causes resistance to corticosteroid therapy and elevated hospitalization risk. Src family kinases (SFKs) contribute to various steps of the immune response, such as airway inflammation in viral or bacterial infections and allergic asthma. Therefore, we determined the effects of dasatinib (DAS), a typical Src inhibitor, on a murine asthma exacerbation model induced by house dust mites (HDM) and synthetic analog of double-stranded RNA, poly(I:C). A/J mice were sensitized to intrapreneurial HDM twice every seven days and challenged with intranasal HDM once every second day for a total of six exposures, and/or exposed to poly(I:C) twice daily for three consecutive days. Drug treatments were performed twice daily for three days, starting one day after the last HDM challenge or 2 h before each poly(I:C) exposure. DAS improved poly(I:C)-induced acute inflammation dose-dependently. Both DAS and fluticasone propionate (FP) attenuated HDM-induced allergic airway inflammation. However, in HDM and poly(I:C) induced-asthma exacerbated mice, DAS significantly improved inflammatory cells in bronchoalveolar lavage fluid and histological changes in the lungs, whereas FP did not. Therefore, SFKs are important targets for controlling severe asthma refractory to conventional therapies.

Diet Therapy Using a Small Rice Bowl among Japanese Men with Diabetes: A Randomized Controlled Trial.

Background: This study aimed to investigate the effectiveness at 1 and 3 months of using a smaller rice bowl for diet therapy among Japanese men with type 2 diabetes. Methods: A parallel-group randomized controlled trial was conducted at a medical clinic in Japan. The participants were men with type 2 diabetes mellitus, aged 20-80 years, with glycosylated hemoglobin <8.5%, and who ate rice one or more times per day at home. The intervention group (36 men) received a small rice bowl from which to eat the usual diet therapy, and the control group (38 men) received only the usual diet therapy. Results: The changes in weight and body mass index among the intervention group at 1 month were significantly higher than those in the control group. There were no significant differences between the two groups at 3 months. Conclusion: The effects of using a small rice bowl were minor and short-term.

Impact of actual waiting time and perceived waiting time on treatment satisfaction in patients receiving outpatient diabetes care.

AIMS: We investigated the impact of actual waiting time and perceived waiting time on treatment satisfaction in patients with diabetes receiving outpatient care. METHODS: Three hundred and thirty-six outpatients diagnosed with diabetes mellitus or impaired glucose tolerance were selected and the time they spent in reception, blood collection, consultation, and accounting were recorded to measure the time they spent waiting in the hospital (actual waiting time). Simultaneously, we conducted a questionnaire survey that included questions on their perceptions of the waiting time (perceived waiting time) and satisfaction with treatment (DTSQ). RESULTS: No significant relationship was found between actual waiting time and DTSQ score, although associations were observed with perceived waiting time. The patients who felt the overall waiting time was long scored 23.0, those who felt it was short scored 26.0, and those who felt it was very short scored 34.0, with those who felt the waiting time was long having a significantly lower score (p = 0.004, p < 0.001, respectively) and those who felt it was short having a significantly lower score than those who felt it was very short (p = 0.008). In addition, more patients who felt the waiting time was long expressed dissatisfaction with the responses of doctors and staff than those who felt the waiting time was short. CONCLUSIONS: These results suggest that in addition to reducing actual waiting times, shortening perceived waiting times by improving the responses of medical staff could help to increase patient satisfaction.

Correction to: Impact of actual waiting time and perceived waiting time on treatment satisfaction in patients receiving outpatient diabetes care.

[This corrects the article DOI: 10.1007/s13340-020-00486-y.].

Effects of proprotein convertase subtilisin/kexin type 9 and nilotinib plasma concentrations on nilotinib-induced hypercholesterolaemia in patients with chronic myeloid leukaemia.

WHAT IS KNOWN AND OBJECTIVE: The purpose of this study was to investigate the relationships among nilotinib plasma trough concentration (C0 ), low-density lipoprotein (LDL) cholesterol, and PCSK9 plasma concentration in 31 patients with chronic myeloid leukaemia. METHODS: Plasma concentrations of nilotinib and PCSK9 were measured by high-performance liquid chromatography and enzyme-linked immunosorbent assays, respectively. RESULTS AND DISCUSSION: LDL cholesterol concentrations at 1 month after nilotinib treatment were significantly increased compared with those before therapy. The mean C0 (±SD) of nilotinib at 1, 2, and 3 months after nilotinib treatment were 645 ± 516, 902 ± 623, and 951 ± 1088 ng/mL, respectively. Mean PCSK9 concentrations at 3 months after nilotinib treatment were significantly higher than those at the start of therapy (320 vs 257 ng/mL, respectively, P = .019). When the change rate in the PCSK9 concentration induced by nilotinib was classified with a cut-off value of +40%, the change rate in LDL cholesterol in patients with a change rate in PCSK9 of ≥40% was significantly higher than that in patients with a PCSK9 change rate of <40% (67.1% vs 38.0%, P = .043); however, there were no differences in mean nilotinib C0 . WHAT IS NEW AND CONCLUSION: Nilotinib may lead to hypercholesterolaemia by increasing plasma concentrations of PCSK9 after indirect inhibition of mammalian target of rapamycin (mTOR) complex 1. In addition, certain patients seem to have high sensitivity for nilotinib in a signalling cascade of the PI3K/Akt/mTOR pathway, despite low plasma concentrations of nilotinib. Consequently, nilotinib-induced hypercholesterolaemia could not be predicted based on the plasma concentration of nilotinib.

Changes in PCSK9 and LDL cholesterol concentrations by everolimus treatment and their effects on polymorphisms in PCSK9 and mTORC1.

BACKGROUND: The purpose of this study was to evaluate the effects of concentrations of proprotein convertase subtilisin/kexin type 9 (PCSK9) and low-density lipoprotein (LDL) cholesterol by the mammalian target of rapamycin (mTOR) inhibitor everolimus and their effects on genetic polymorphisms in the PCSK9 and mTORC1 genes in 53 renal transplant recipients. METHODS: Prior to and on day 15 after everolimus administration, the concentrations of everolimus in blood and PCSK9 and LDL cholesterol in plasma were evaluated. Additionally, mTORC1 (rs2536T>C and rs2295080T>G) and PCSK9 (rs505151G>A, rs562556G>A, and rs11593680C>T) polymorphisms were analyzed. RESULTS: Mean PCSK9 plasma concentrations on day 15 after everolimus treatment were significantly higher than those before treatment (295 versus 214 ng/mL, respectively; p = 0.004). Significant correlations between the area under the blood concentration-time curves (AUC)0-12 on day 15 of everolimus treatment and the change rate in PCSK9 concentrations were found (r = 0.316, p = 0.021). However, there were no significant correlations between the change rate in PCSK9 and LDL cholesterol concentrations. The change rate in PCSK9 concentrations by everolimus treatment was significantly greater in patients with the mTORC1 rs2295080G allele than the T/T genotype (p = 0.006); however, there were no significant differences between PCSK9 rs505151G>A and rs11583680C>T genotypes. In multivariate analyses, patients with mTORC1 rs2295080G (p = 0.010), higher everolimus AUC0-12 (p = 0.006), and female sex (p = 0.029) showed higher change rates of PCSK9 following everolimus therapy. CONCLUSIONS: Administration of everolimus significantly elevated plasma PCSK9 concentrations, potentially causing everolimus-induced hyperlipidemia.

Quantitative Evaluation of Drug Resistance Profile of Cells Expressing Wild-Type or Genetic Polymorphic Variants of the Human ABC Transporter ABCC4.

Broad-spectrum resistance in cancer cells is often caused by the overexpression of ABC transporters; which varies across individuals because of genetic single-nucleotide polymorphisms (SNPs). In the present study; we focused on human ABCC4 and established cells expressing the wild-type (WT) or SNP variants of human ABCC4 using the Flp-In™ system (Invitrogen, Life Technologies Corp, Carlsbad, CA, USA) based on Flp recombinase-mediated transfection to quantitatively evaluate the effects of nonsynonymous SNPs on the drug resistance profiles of cells. The mRNA levels of the cells expressing each ABCC4 variant were comparable. 3-(4,5-Dimethyl-2-thiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay clearly indicated that the EC50 values of azathioprine against cells expressing ABCC4 (WT) were 1.4-1.7-fold higher than those against cells expressing SNP variants of ABCC4 (M184K; N297S; K304N or E757K). EC50 values of 6-mercaptopurine or 7-Ethyl-10-hydroxy-camptothecin (SN-38) against cells expressing ABCC4 (WT) were also 1.4-2.0- or 1.9-fold higher than those against cells expressing the SNP variants of ABCC4 (K304N or E757K) or (K304N; P403L or E757K); respectively. These results indicate that the effects of nonsynonymous SNPs on the drug resistance profiles of cells expressing ABCC4 can be quantitatively evaluated using the Flp-In™ system.

The effects of gestational transient thyrotoxicosis on the perinatal outcomes: a case-control study.

PURPOSE: To study the effects of gestational transient thyrotoxicosis (GTT) on pregnancy outcomes. METHODS: This case-control study retrospectively analyzed 7976 women with singleton pregnancies whose thyroid function was measured before 16 weeks of gestation and who delivered at ≥22 weeks of pregnancy. GTT was defined as hyperthyroidism (free thyroxine [FT4] level: ≥95th percentile) in the early pregnancy, which normalized in mid-pregnancy without thyroid-stimulating hormone receptor antibodies. Using data extracted from electronic records, we examined the association between GTT and the pregnancy outcomes (preterm delivery, gestational age at delivery, pregnancy induced hypertension (PIH), preeclampsia, placental abruption, caesarian section, birth weight, low birth weight, Apgar score, cord pH, stillbirth at gestational week ≥22, and neonatal death). We classified the cases into quartiles according to their FT4 values during the early pregnancy and investigated the association with the gestational age at delivery. RESULTS: Two hundred and eight cases of GTT and 6317 cases with normal thyroid assessments were reviewed. GTT was associated with hyperemesis gravidarum, but not with stillbirth, preterm delivery, PIH, preeclampsia, placental abruption, or low birth weight. The gestation period was shorter in patients with GTT than in those with a normal thyroid function (38.69 ± 1.79 vs. 39.07 ± 1.64 weeks, p < 0.01). Higher FT4 levels during the early pregnancy were associated with earlier delivery (p = 0.02). CONCLUSIONS: GTT was associated with a lower gestational age at delivery but not with adverse pregnancy outcomes. There was a negative correlation between the FT4 values in the early pregnancy and the gestational period.

Knockdown of gene expression by antisense morpholino oligos in preimplantation mouse embryos cultured in vitro.

Knockdown of gene expression by antisense morpholino oligos (MOs) is a simple and effective method for analyzing the roles of genes in mammalian cells. Here, we demonstrate the efficient delivery of MOs by Endo-Porter (EP), a special transfection reagent for MOs, into preimplantation mouse embryos cultured in vitro. A fluorescein-labeled control MO was applied for monitoring the incorporation of MOs into developing 2-cell embryos in the presence of varying amounts of EP and bovine serum albumin. In optimized conditions, fluorescence was detected in 2-cell embryos within a 3-h incubation period. In order to analyze the validity of the optimized conditions, an antisense Oct4 MO was applied for knockdown of the synthesis of OCT4 protein in developing embryos from the 2-cell stage. In blastocysts, the antisense Oct4 MO induced a decrease in the amount in OCT4 protein to less than half. An almost complete absence of OCT4-positive cells and nearly complete disappearance of the inner cell mass in the outgrowths of blastocysts were also noted. These phenotypes corresponded with those of Oct4-deficient mouse embryos. Overall, we suggest that the delivery of MOs using EP is useful for the knockdown of gene expression in preimplantation mouse embryos cultured in vitro.

Partial inhibition of differentiation associated with elevated protein levels of pluripotency factors in mouse embryonic stem cells expressing exogenous EGAM1N homeoprotein.

We previously reported that transcripts encoding the homeoprotein EGAM1N are expressed in preimplantation mouse embryos and embryonic stem (ES) cells, and the exogenous expression of EGAM1N inhibits the differentiation of ES cells. In order to clarify the relationship between the inhibition of differentiation and EGAM1N, we generated mouse MG1.19 ES cells stably expressing EGAM1N. Control transfectants with an empty vector formed relatively flattened cell colonies similar to those observed in parental MG1.19 cells. In contrast, Egam1n transfectants formed tightly aggregated cell colonies with increased localization of CDH1 at cell-to-cell interfaces. The protein levels of pluripotency factors, including TBX3 and SOX2, were also increased. The expression of Tbx3 transcripts was induced, although the level of Sox2 transcripts was almost unchanged. The expression of EGAM1N resulted in no obvious changes in the expression of genes encoding receptors, protein kinases, transcription factors, and their encoded proteins involved in the LIF-STAT3 signaling pathway. Alkaline phosphatase activity, a marker for the undifferentiated state, in Egam1n transfectants was exhibited in a clonal proliferation assay. When differentiation of Egam1n transfectants was induced, progression was prevented with increases in transcript levels of Pou5f1, Sox2, Nanog, Klf4, Tbx3, and their encoded proteins. However, Egam1n transfectants formed relatively flattened-cell layers as observed in the control, indicating that the expression of EGAM1N could not maintain LIF-independent self-renewal of ES cells. Overall, we suggest that expression of EGAM1N could inhibit differentiation, at least in part, by elevating the protein levels of pluripotency factors in MG1.19 ES cells.

Changes in serum iodine concentration, urinary iodine excretion and thyroid function after hysterosalpingography using an oil-soluble iodinated contrast medium (lipiodol).

OBJECTIVE: Reports of hypothyroidism after hysterosalpingography (HSG) using lipiodol are emerging. The present study was designed to investigate the changes in serum iodine concentration (SIC), urinary iodine concentration/creatinine excretion (UI/Cr), and thyroid function before and after HSG using lipiodol. METHODS: The prospective observation study included 22 infertile euthyroid women with no previous history of thyroid disease. All underwent HSG between April 2007 and August 2008 at our institution. We examined SIC, UI/Cr, and thyroid function before HSG, and at 4, 8, 12, and 24 weeks, and 9-12 months after HSG. RESULTS: The median value of SIC and UI/Cr peaked at 4 weeks after HSG and remained at significantly high levels at 8, 12, and 24 weeks post-HSG compared with pre-HSG. In sync with the increase of iodine, the mean level of TSH significantly increased at 4, 8, 12, and 24 weeks post-HSG compared with pre-HSG. After 24 weeks, differences in SIC, UI/Cr, and TSH levels before and after HSG became nonsignificant. The mean value of free triiodothyronine and free thyroxine showed no significant difference at any of the time points compared with pre-HSG. Three cases (13.6%) showed transient high TSH (>5 µIU/L) with normal thyroid hormones at 4 or 8 weeks after HSG. CONCLUSION: Thyroid monitoring should be conducted in the first 4-8 weeks after HSG using lipiodol and attention to thyroid dysfunction should be paid for up to 6 months after the procedure due to the possibility of excess iodine.

Photoresponsive stripe pattern in achiral azobenzene liquid crystals.

A periodic stripe pattern is found in the nematic phase close to the smectic phase of photoresponsive achiral liquid-crystalline compounds. The origin of the stripe patterns can be ascribed to an extremely large bent elastic constant K33 . In addition, we succeeded in controlling the pattern by the following two methods: 1) the stripe disappears by a trans-cis photoisomerization upon UV light irradiation and reappears upon light termination, and 2) the stripe pattern is stabilized over the whole nematic phase, at approximately 10 °C, by polymerization of the compounds.

Generation of aminoterminally truncated, stable types of bioactive bovine and porcine fibroblast growth factor 4 in Escherichia coli.

Fibroblast growth factor 4 (FGF4) is a crucial growth factor for the development of mammalian embryos. We previously produced hexahistidine-tagged, bovine and porcine FGF4 (Pro(32) to Leu(206) ) proteins without a secretory signal peptide at the aminoterminus in Escherichia coli. Here, we found that these were unstable; site-specific cleavage between Ser(54) and Leu(55) in both FGF4 derivatives was identified. In order to generate stable FGF4 derivatives and to investigate their biological activities, aminoterminally truncated and hexahistidine-tagged bovine and porcine FGF4 (Leu(55) to Leu(206) ) proteins, termed HisbFGF4L and HispFGF4L, respectively, were produced in E. coli. These FGF4 derivatives were sufficiently stable and exerted mitogenic activities in fibroblasts. Treatment with the FGF4 derivatives promoted the phosphorylation of ERK1/2, which are crucial kinases in the FGF signaling pathway. In the presence of PD173074, an FGF receptor inhibitor, the phosphorylation of ERK1/2 was inhibited and resulted in abolition of the growth-promoting activity of FGF4 derivatives. Taken together, we demonstrate that HisbFGF4L and HispFGF4L are capable of promoting the proliferation of bovine- and porcine-derived cells, respectively, via an authentic FGF signaling pathway. These FGF4 derivatives may be applicable for dissecting the roles of FGF4 during embryogenesis in cattle and pigs.

Comparison of efficacy and adverse effects between methimazole 15 mg+inorganic iodine 38 mg/day and methimazole 30 mg/day as initial therapy for Graves' disease patients with moderate to severe hyperthyroidism.

BACKGROUND: Methimazole (MMI) is usually used at an initial dose of 30 mg/day for severe Graves' disease (GD) hyperthyroidism, but adverse effects are more frequent at this dose than at MMI 15 mg/day. OBJECTIVES: We designed a regimen to address the lack of a primary therapeutic effect of the MMI 15 mg/day by combining it with inorganic iodine at 38.2 mg/day. Our aim was to compare the two regimens (MMI 15 mg+inorganic iodine at 38.2 mg/day (M15+I) vs. MMI 30 mg/day (M30)) in terms of therapeutic effect, adverse effects, and remission rate. DESIGN AND PATIENTS: In a prospective study, 310 patients with untreated GD (serum free thyroxine (fT4) ≥5 ng/dL) were assigned to one of the two regimens. Potassium iodide was discontinued in the M15+I group as soon as the serum fT4 level was within the reference range (0.8-1.6 ng/dL). RESULTS: Percentages of patients achieving an fT4 level within reference range in ≤30, ≤60, or 90 days on the study treatment regimens were 45.3%, 73.9%, and 82.0% respectively for the M15+I group, and 24.8%, 63.1%, and 75.2% respectively for the M30 group. Hence, the proportions of patients achieving this goal in ≤30 or ≤60 days were significantly larger in the M15+I group. Adverse effects that required discontinuation of MMI were more frequent in the M30-treated than in the M15+I-treated group (14.8% vs. 7.5%; p=0.0387). The remission rates in the M15+I and M30 groups were 19.9% and 14.8%-higher in the former, but the difference did not reach statistical significance. CONCLUSION: The results of this study raise the possibility that M15+I is superior to M30 as a primary treatment for moderate to severe hyperthyroidism caused by GD.

Attentional capture by completely task-irrelevant faces.

The present study investigated whether faces capture attention regardless of attentional set. The presentation of a face as a distractor during a visual search has been shown to impair performance relative to when the face was absent, implying that faces automatically attract attention. If attentional control is contingent on the observer's current goal, faces should not capture attention when they are irrelevant to the observer's attentional set. Previous studies demonstrating face-induced attentional capture used faces that were relevant to the task. Thus, a task in which faces were completely irrelevant to the observer's set was created. Participants identified a target letter among heterogeneously colored non-targets while ignoring a peripheral facial image that appeared as a brief distractor. No face-specific capture was observed when the target-distractor stimulus onset asynchrony (SOA) was long (Experiment 1). When the SOA was shortened, attentional capture by irrelevant faces was observed (Experiment 2). Experiment 3 extended this finding to all conditions, regardless of the attractiveness of faces. No such capture effect was found in Experiment 4 with inverted-face distractors. These results indicate that completely task-irrelevant faces break through top-down attentional set given a brief distractor-target SOA.

Increased expression of the histamine H4 receptor following differentiation and mediation of the H4 receptor on interleukin-8 mRNA expression in HaCaT keratinocytes.

Recent in vivo studies have demonstrated involvement of the histamine H4 receptor in pruritus and skin inflammation. We previously reported that an H4 receptor antagonist attenuated scratching behaviour and improved skin lesions in an experimental model of atopic dermatitis. We also reported the expression of the H4 receptor in human epidermal tissues. In this study, we investigated the expression of H4 receptor mRNA and the function of the receptor in a culture system that mimics in vivo inflammation on the HaCaT human keratinocyte cell line. Increased expression of the H4 receptor was observed in HaCaT cells following differentiation. Treatment of HaCaT cells with histamine and TNFα enhanced the mRNA expression of interleukin (IL)-8. These increases in expression were significantly inhibited by the H4 receptor antagonist JNJ7777120. Our results indicate that IL-8 mRNA expression might be enhanced by histamine and TNFα via H4 receptor stimulation in keratinocytes.

Identification of site-specific degradation in bacterially expressed human fibroblast growth factor 4 and generation of an aminoterminally truncated, stable form.

Fibroblast growth factor 4 (FGF4) is considered as a crucial gene for tumorigenesis in humans and the development of mammalian embryos. The secreted, mature form of human FGF4 is thought to be comprised of 175 amino acid residues (proline(32) to leucine(206), Pro(32)-Leu(206)). Here, we found that bacterially expressed, 6× histidine (His)-tagged human FGF4 (Pro(32)-Leu(206)) protein, referred to as HishFGF4, was unstable such as in phosphate-buffered saline. In these conditions, site-specific cleavage, including between Ser(54) and Leu(55), in HishFGF4 was identified. In order to generate stable human FGF4 derivatives, a 6× His-tagged human FGF4 (Leu(55)-Leu(206)), termed HishFGF4L, was expressed in Escherichia coli. HishFGF4L could be purified from the supernatant of cell lysates by heparin column chromatography. In phosphate-buffered saline, HishFGF4L was considered as sufficiently stable. HishFGF4L exerted significant mitogenic activities in mouse embryonic fibroblast Balb/c 3T3 cells. In the presence of PD173074, an FGF receptor inhibitor, the growth-stimulating activity of HishFGF4L disappeared. Taken together, we suggest that HishFGF4L is capable of promoting cell growth via an authentic FGF signaling pathway. Our study provides a simple method for the production of a bioactive human FGF4 derivative in E. coli.