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Fish-borne pathogens such as A. hydrophila and F. aquidurense are the most resistant strains in pisciculture farming. Removing the aforementioned pathogens without antibiotics presents a formidable challenge. To overcome this problem, silver nanoparticles (AgNPs) are synthesized using silver nitrate, water medium, and as an AzadirachtaIndica leaf extract via the green synthesis route. X-ray diffraction (XRD) pattern results authenticate the synthesized material is the face-centered cubic structure of silver. The optical absorption edge of the synthesized product was found at the wavelength of 440 nm from the UV-visible spectra, which is confirmed to relate to the Surface Plasmon Resonance peaks of silver particles. In addition, the optical band gap value of the synthesized Ag sample is measured to be 2.81 eV from the obtained optical absorption spectra. EDX spectrum of the synthesized product also supports confirming the silver particle formation. The FT-IR spectra of the neem extract and silver nanoparticles showed their characteristic functional groups, respectively. The presence of bands between 1000 cm-1 to 500 cm-1 indicates to the formation of silver particles. Spherical particles appeared in the synthesized Ag using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The particle size of Ag NPs was measured as 40 nm and 62 ± 10 nm by TEM and Dynamic Light Scattering (DLS). The zeta potential was also measured as -12 mV showing the synthesized sample's stable nature. Using the DPPH assay, synthesized AgNPs were taken along with the various concentrations of ascorbic acid (20, 40, 60, 80, and 100 µg/mL) to examine the free radical scavenging activity (RSA). RSA value is higher (84 ± 2 %) for synthesized AgNPs at higher concentration (100 µg/mL) than 21 ± 2 % at low concentration (100 µg/mL). The antimicrobial efficacy of the AgNPs against A. hydrophila and F. aquidurense was performed through the agar diffusion method and its results showed the inhibitory zones of the F.aquidurense and A. hydrophila were measured as 25 ± 3 mm, and 28 ± 4 mm respectively. The synthesized Ag particles showed excellent antimicrobial and antioxidant properties confirmed by antimicrobial and DPPH experiments. It implies that the green synthesized silver nanoparticles could be a good alternative for antibiotics in aquaculture farms. The exposure of low concentrations of silver nanoparticles to zebrafish and brine shrimp does not affect the viability and morphology. The exposure of silver nanoparticles in the fisheries in optimized concentration and time could control the fish-borne pathogens without antibiotics.
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Tecnología Química Verde , Nanopartículas del Metal , Pruebas de Sensibilidad Microbiana , Extractos Vegetales , Plata , Difracción de Rayos X , Plata/farmacología , Plata/química , Nanopartículas del Metal/química , Animales , Extractos Vegetales/farmacología , Extractos Vegetales/química , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Hojas de la Planta/química , Azadirachta/química , Espectroscopía Infrarroja por Transformada de Fourier , Antioxidantes/farmacología , Antioxidantes/química , Aeromonas hydrophila/efectos de los fármacos , Microscopía Electrónica de Transmisión , Antiinfecciosos/farmacología , Antiinfecciosos/química , Tamaño de la Partícula , Microscopía Electrónica de Rastreo , Peces , Nitrato de Plata/farmacología , Nitrato de Plata/química , Compuestos de Bifenilo , Enfermedades de los Peces/tratamiento farmacológico , Enfermedades de los Peces/microbiología , PicratosRESUMEN
STATEMENT OF PROBLEM: Quaternary ammonium (QA)-based monomers such as dimethyl-hexadecyl-methacryloxyethyl-ammonium iodide (DHMAI) and 2-dimethyl-2-dodecyl-1-methacryloxyethyl ammonium iodine (DDMAI) have been investigated as copolymerizable monomers to impart antimicrobial activity to dental restorative and prosthetic materials. However, the biocompatibility of these antimicrobial monomers needs to be investigated in vivo before their clinical use. PURPOSE: The purpose of this study was to assess the in vivo biocompatibility of polymethyl methacrylate (PMMA) heat-polymerizing denture base resin copolymerized with varying concentrations of DHMAI and DDMAI. MATERIAL AND METHODS: The toxicity and genotoxicity of the antimicrobial monomers (DHMAI 5 µg/mL and DDMAI 20 µg/mL) at 1 to 100 µg/mL concentrations were investigated against zebrafish embryos (Danio rerio, n=10) using a zebrafish embryotoxicity test (ZET) or fish embryotoxicity test (FET) and comet assay, respectively. Further, DHMAI 5 µg/mL and DDMAI 20 µg/mL were incorporated into a conventional PMMA denture base system and a similar test was done on specimens of modified PMMA resin. For the evaluation of in vivo biocompatibility, modified PMMA specimens were subcutaneously implanted into Wistar rats (n=6) and biochemical, hematological, and histopathological parameters were investigated. Results were analyzed and compared using ANOVA and the Tukey post hoc test (α=.05). RESULTS: Toxicity and genotoxicity studies using zebrafish embryos revealed that the incorporation of monomer to PMMA did not increase the toxicity, as confirmed by post-hour fertilization. Modified PMMA did not affect the hematological parameters, such as red blood cell (RBC) and white blood cell (WBC) except for the platelet count, which was significantly increased (P<.001), and the biochemical parameter, such as total protein (TP), blood urea nitrogen (BUN), serum glutamic-oxaloacetic transaminase (SGOT), triglyceride (TG), creatinine (Crea), total cholesterol, and serum glutamic pyruvic transaminase (SGPT), except for high-density lipoprotein (HDL) cholesterol, which was significantly decreased (P<.01). Histopathologically, no changes were observed in the sections of the liver, kidney, spleen, and subcutaneous tissues in the modified PMMA implanted rats. Additionally, no significant variation was found in the expression of immunohistochemical marker tumor necrosis factor alpha (TNF-α), confirming the noninflammatory response exerted by the modified PMMA on experimental rats. CONCLUSIONS: Zebrafish embryos treated with modified PMMA specimens demonstrated favorable biological properties and did not exhibit significant cytotoxicity and genotoxicity. Subcutaneously implanted modified PMMA did not cause any major hematological, biochemical, and histopathological alterations in Wistar albino rats, thus confirming the biocompatibility of PMMA heat-polymerizing denture base resin incorporated with DHMAI and DDMAI for dental applications.
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Materiales Biocompatibles , Bases para Dentadura , Polimerizacion , Polimetil Metacrilato , Pez Cebra , Polimetil Metacrilato/toxicidad , Polimetil Metacrilato/química , Animales , Ensayo de Materiales , Antiinfecciosos/farmacología , Ratas , Compuestos de Amonio Cuaternario/toxicidad , Materiales Dentales/toxicidad , Ratas WistarRESUMEN
In the last few decades, the broad scope of nanomedicine has played an important role in the global healthcare industry. Biological acquisition methods to obtain nanoparticles (NPs) offer a low-cost, non-toxic, and environmentally friendly approach. This review shows recent data about several methods for procuring nanoparticles and an exhaustive elucidation of biological agents such as plants, algae, bacteria, fungi, actinomycete, and yeast. When compared to the physical, chemical, and biological approaches for obtaining nanoparticles, the biological approach has significant advantages such as non-toxicity and environmental friendliness, which support their significant use in therapeutic applications. The bio-mediated, procured nanoparticles not only help researchers but also manipulate particles to provide health and safety. In addition, we examined the significant biomedical applications of nanoparticles, such as antibacterial, antifungal, antiviral, anti-inflammatory, antidiabetic, antioxidant, and other medical applications. This review highlights the findings of current research on the bio-mediated acquisition of novel NPs and scrutinizes the various methods proposed to describe them. The bio-mediated synthesis of NPs from plant extracts has several advantages, including bioavailability, environmental friendliness, and low cost. Researchers have sequenced the analysis of the biochemical mechanisms and enzyme reactions of bio-mediated acquisition as well as the determination of the bioactive compounds mediated by nanoparticle acquisition. This review is primarily concerned with collating research from researchers from a variety of disciplines that frequently provides new clarifications to serious problems.
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Nanopartículas del Metal , Nanopartículas , Nanopartículas del Metal/química , Plantas/química , Bacterias , Antibacterianos/química , Nanomedicina , Extractos Vegetales/químicaRESUMEN
Background The management of aggressive forms of periodontal disease has become an issue of concern due to the emergence of bacterial resistance. Nanoparticles (NPs) have emerged as a potential therapeutic agent with a multitude of biological functions. The green synthesis of these NPs is more eco-friendly than conventional methods. The present study aimed at the green synthesis of magnesium oxide nanoparticles using Bacopa monnieri (bMgO NPs) and its antibacterial, antioxidant, and cytotoxic analysis. Materials and methods Magnesium oxide NPs were green synthesized using B. monnieri extract using a wet chemical method. The resultant bMgO NPs were assessed for antibacterial activity against Staphylococcus aureus and Escherichia coli. Antioxidant activity was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and the hydrogen peroxide (H2O2) assay. Cytotoxicity was assessed using zebrafish viability on treatment with bMgO NPs. Results Compared to the antibiotic standard, the green synthesized bMgO NPs showed good antibacterial properties against S. aureus and E. coli. It also showed excellent antioxidant activity and biocompatibility. Conclusion The bMgO NPs have great potential as a local drug delivery agent and should be further explored for their antibacterial and antioxidant properties in vivo.
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Carrageenan is an emerging biopolymer for wound healing and regenerative applications. In this study, reduced graphene oxide (rGO) and hydroxyapatite (HAp) nano-composites infused carrageenan bioactive membrane was fabricated. Here, hydroxyapatite was synthesized from cuttlefish bone (CF-HAp) and its properties were compared with that of chemically synthesized HAp. Crystalline Ca5(PO4)3(OH) and Ca3(PO4)2) phases were obtained in cuttlefish bone derived HAp. Reduced graphene oxide was synthesized and composites were prepared with chemical HAp and CF-HAp. FT-IR spectral analysis showed the imprints of hydroxyapatite on the membrane and also nano-structured particles were evident through morphological estimations that confirm the distribution of nano-particles on the carrageenan membrane. Nano-particulates infused carrageenan membrane showed the maximum tensile strength, in which graphene incorporated carrageenan bioactive membrane showed highest stability of 15.26 MPa. The contact angle of chemical HAp infused carrageenan membrane (CAR-HAp) showed more hydrophilic in nature (48.63° ± 7.47°) compared to control (61.77° ± 1.28°). Bio-compatibility features enunciate the optimal compatibility of fabricated bioactive membrane with fibroblast cell line; simultaneously, CAR-rGO-CF-HAp showed tremendous wound healing behavior with zebrafish model. Hence, fabricated bioactive membrane with the infusion of rGO- hydroxyapatite derived from cuttlefish bone was found to be a versatile biopolymer membrane for wound healing application.
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Durapatita , Grafito , Animales , Durapatita/química , Grafito/química , Carragenina , Decapodiformes , Espectroscopía Infrarroja por Transformada de Fourier , Pez Cebra , BiopolímerosRESUMEN
Background Terminalia bellirica leaf extract was used as an herbal to get an aqueous extract of Tb-ZnO-TiO2 (zinc and titanium dioxide) nanoparticles composite, and this was subsequently subjected to an analysis of its antioxidant properties and possible antimicrobial activity against gram-negative and gram-positive bacteria. Employing the 2,2-Diphenyl-1-picrylhydrazyl and hydrogen peroxide assay techniques for antioxidant properties. In addition to their biocompatibility, rapid biodegradability, and low toxicity, herbal-based nanoparticles (Tb-ZnO-TiO2 NPs composite) synthesized by T. bellirica have drawn a lot of interest as promising options for administering drugs and effective antimicrobial applications. Materials and methods The form and dimensions of the dispersion of the synthesized nanoparticles were investigated through scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy, and UV-visible for particle characterization. Nanoparticles were analyzed for antimicrobial activity using the well diffusion method. Ascorbic acid and vitamin E were used as two separate controls for antioxidant assay with different concentrations, and also toxicity assay was done by using zebrafish embryos. Results Tb-ZnO-TiO2 NPs composite were obtained as a powder, the X-beam diffraction (XRD) result revealed a small quantity of impurities and revealed that the structure was spherical in nature. A unique absorption peak for Tb-ZnO-TiO2 NPs composite may be seen in UV-Vis spectroscopy which is in the region of 260 to 320 nm. The Tb-ZnO-TiO2 NPs composite antibacterial efficacy was evaluated and showed noted antibacterial activity and free radical scavenging activity with less toxicity. Conclusion The results demonstrated the Tb-ZnO-TiO2 NPs composite has strong antioxidant qualities and enormous antibacterial activity obtained from T. bellirica extract. Therefore, the Tb-ZnO-TiO2 NPs composite synthesized nanoparticles can be used in biomedical applications as an effective antioxidant and antibacterial reagent.
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[This corrects the article DOI: 10.7759/cureus.58701.].
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Background Calcium magnesium phosphate (CMP)-based whitlockite is a promising biomaterial for hemostasis and regenerative applications. Regenerative approaches aim to advance tissue repair and recovery in different clinical scenarios. Whitlockite is a biocompatible and biodegradable mineral that has garnered impressive consideration for its interesting properties, making it an appealing candidate for therapeutic applications. Aim This study aimed to evaluate the hemostatic behavior of synthesized whitlockite nanoparticles. Materials and methods Coprecipitation and hydrothermal methods were used to synthesize whitlockite nanoparticles. Calcium nitrate, magnesium nitrate, and diammonium hydrogen phosphate were used as precursors to prepare this material. Results Crystalline phases of whitlockite (Ca3Mg)3(PO4) and calcium magnesium phosphate Ca7Mg2P6O2 were observed through X-ray diffraction (XRD) patterns, along with relevant properties of the phosphate functional group detected through Raman spectra. This study explores the hemostatic adequacy of CMP-based whitlockite using different methodologies. The capacity of the materials to actuate platelet conglomeration and encourage clot arrangement is assessed using in vitro experiments. Moreover, this study investigates the regenerative potential of CMP-based whitlockite in tissue-building applications. Conclusion The structural and morphological parameters provide crucial insights into the proper formation of the material, and the hemoclot assessment aids in understanding its coagulation behavior. Future investigations and clinical trials will be instrumental in fully harnessing the potential of CMP-based whitlockite for advancing hemostasis and regenerative medicine.
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The present study aims to examine the characteristics of a composite material composed of glass/madar fibers and porcelain particles, which are reinforced with epoxy. A compression molding technique achieves the fabrication of this composite. A comprehensive characterization was conducted by employing a mixture of analytical techniques, including X-ray Diffraction (XRD), mechanical testing, Scanning Electron Microscopy (SEM), Dynamic Mechanical Analysis (DMA), and Thermogravimetric Analysis (TGA). The composition of the composite was determined using X-ray diffraction (XRD) analysis, which demonstrated the successful integration of porcelain fillers. The material exhibited notable mechanical properties, rendering it appropriate for utilization in structural applications. The utilization of SEM facilitated the examination of the microstructure of the composite material, thereby providing a deeper understanding of the interactions between the fibers and the matrix. DMA results revealed the glass/madar composite contained 4.2% higher viscoelastic properties when the addition of porcelain filler, thermal stability was improved up to the maximum temperature of 357 °C. This study provided significant insights into the properties of a hybrid epoxy composite consisting of glass/madar fibers reinforced porcelain particles.
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Aim This study aimed to evaluate the cytotoxicity of a novel compound, 4-hydroxycinnamic acid (4-HCA), with the help of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and zebrafish embryotoxicity. Materials and methods In this in vitro study, MTT fibroblast assays using dental pulp stem cells, which were cultured in Modified Eagle's Medium or Dulbecco's Modified Eagle Medium, and zebrafish cytotoxicity and embryotoxicity were done to evaluate the cytotoxicity of the novel compound 4-HCA. The data was analyzed by plotting cell number versus absorbance, allowing quantitation of changes in cell proliferation. Results 4-HCA (40 µl) showed acceptable levels of cell viability according to the American Society for Testing and Materials standards. Cell viability is reduced with increased exposure time and concentrations of 4-HCA. Similarly, the cytotoxicity assessment in zebrafish (Danio rerio) showed an acceptable range of toxicity levels in embryonic stages used to evaluate the mortality rate of zebrafish embryos. Conclusion Considering the constraints of this research, it can be deduced that hydroxycinnamic acid at a concentration of 40 µl was non-toxic. The findings from the MTT assay indicated a correlation between the concentration and the toxicity of the compound. Likewise, the zebrafish test demonstrated minimal toxicological effects.
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The current research is concerned with the synthesis of magnesium oxide (MgO) nanoparticles (NPs) from Abrus precatorius L. bark extract via the green chemistry method. The synthesized MgO NPs was confirmed by using several characterization methods like XRD, FTIR, SEM, TEM, and UV-visible analysis. The synthesized MgO NPs displayed a small particle size along with a specific surface area. Abrus precatorius bark synthesized MgO NPs with a higher ratio of dye degradation, and antioxidant activity showed a higher percentage of free radical scavenging in synthesized MgO NPs. Zebrafish embryos were used as a model organism to assess the toxicity of the obtained MgO nanoparticles, and the results concluded that the MgO NPs were nontoxic. In addition, the anticancer properties of MgO nanoparticles were analyzed by using a human melanoma cancer cell line (A375) via MTT, XTT, NRU, and LDH assessment. MgO NPs treated a human melanoma cancer cell line and resulted in apoptosis and necrosis based on the concentration, which was confirmed through a genotoxicity assay. Moreover, the molecular mechanisms in necrosis and apoptosis were conferred to depict the association of magnesium oxide nanoparticles with the human melanoma cancer cell line. The current study on MgO NPs showed a broad-scope understanding of the use of these nanoparticles as a medicinal drug for melanoma cancer via its physiological mechanism and also a novel route to obtain MgO NPs by using the green chemistry method.
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Exopolysaccharides (EPS) are produced by probiotic bacteria Lactiplantibacillus plantarum PRK7 and L. plantarum PRK11. The structure of EPS-7 and EPS-11 was characterized by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), gas chromatography-mass spectroscopy (GCMS), and thermogravimetric analysis (TGA). Further, in in vitro studies antioxidant, emulsion, and antibiofilm activity were investigated. The FTIR spectrum confirmed the presence of polysaccharides in EPS-7 and EPS-11, with absorbance at 1654.93 and 1655.33 cm-1, respectively. H1 NMR further confirmed the presence of glucose, galactose, xylose, and mannose. Sugar derivatives in EPS-7 and EPS-11 were further confirmed with GCMS. The SEM analysis revealed that EPS-7 had a weblike structure and EPS-11 had a smooth porous layer. The result of the TGA revealed that EPS-7 and EPS-11 had greater thermal stability at 319.1 and 300.1 °C, respectively. Furthermore, EPS-7 and EPS-11 showed a good percentage of free radical scavenging in DPPH (89.77 % and 93.1 %), ABTS (57.65 % and 58.63 %), hydroxyl radical scavenging (44.46 % and 40.308 %), and reducing power assay. The emulsion activity was confirmed with edible oils such as coconut oil, sesame oil, almond oil, castor oil, and neem oil. The highest emulsion activity for EPS-7 and EPS-11 was found with coconut and castor oil. In addition, the antibiofilm activity against pathogens revealed that EPS can prevent biofilm formation. Thus, it was found that EPS-7 and EPS-11 possess good structural characteristics and their biological activity makes them ideal for applications in the food and pharmaceutical industry.
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Antioxidantes , Polisacáridos Bacterianos , Antioxidantes/farmacología , Antioxidantes/química , Polisacáridos Bacterianos/farmacología , Polisacáridos Bacterianos/química , Emulsiones , Espectroscopía Infrarroja por Transformada de Fourier , BiopelículasRESUMEN
The present work reveals zinc oxide nanorods (ZnO NRs) obtained via green synthesis approach utilizing phytochemicals present in the Leea asiatica plant. The synthesized ZnO NRs was confirmed by various characterization methods like X-ray diffraction, FTIR, SEM-EDX, UV-vis, TEM and Raman spectra analysis. The obtained nanorods show less particle size with a distinctive high surface area. The photodegradation activity of obtained ZnO NRs shows 81.3 % of dye degradation at high concentration whereas 42.9 % in low concentration and also antioxidant test shows a better result for free radical scavenging. To understand the safety of the ZnO NRs zebrafish embryos was utilized as a model and found to be less toxic after assessment. Furthermore, to understand the anticancer activity of ZnO NRs it was assessed against breast cancer cell line through MTT, XTT, NRU, and LDH assay. The ZnO NRs exposed against breast cancer cell line (MCF-7) had resulted in necrosis and apoptosis which was further confirmed by genotoxicity assay. Also, the molecular mechanisms behind the necrosis and apoptosis are also discussed to show the involvement of ZnO NRs towards breast cancer cells (MCF-7). The present study on ZnO NRs gives a wide spectrum understanding of using ZnO NRs as a potential drug for human breast cancer by showing its physiological pathways as well as a novel way to synthesize ZnO NRs using Leea asiatica plant extract.
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Nanotubos , Óxido de Zinc , Animales , Antioxidantes/farmacología , Humanos , Hojas de la Planta , Pez CebraRESUMEN
INTRODUCTION: Systemic lupus erythematosus (SLE) is an unpredictable autoimmune systemic disorder that often involves the kidney. In this study, we aimed to assess the clinical characteristics, pathological findings, and therapeutic response of children presenting with lupus nephritis (LN). METHODS: We retrospectively studied 50 children with SLE admitted to the pediatric nephrology departments of four teaching hospitals in Baghdad between December 2009 and December 2011. RESULTS: The female to male ratio was 5:3. The median age was 11 years with a range of 5 -17 years. The commonest presenting features were weight loss (92%), fever (90%), edema (88%), arthritis (70%), hair loss (70%) and malar rash (60%). Examination revealed hepatosplenomegaly/lymphadenopathy in 20% of patients. Anti-dsDNA was positive in 92% of patients. Pathological examination revealed LN class I in 4%, class II (10%), class III (8%), class IV (74%) and class V (4%). All patients in class I, II and III achieved full remission after treatment with prednisolone. Thirty-one patients in class IV and V received induction treatment with cyclophosphamide followed by maintenance with cyclophosphamide (16 patients), mycophenolatemofetil (13 patients) or azathioprine (2 patients). Twenty-four of those patients achieved remission, four patients developed chronic kidney disease and three patients died. Five patients in class IV/V were treated with mycophenolate mofetil and three of them achieved remission, whilst three patients were treated with azathioprine and all of them achieved remission. CONCLUSION: Diffuse proliferative glomerulonephritis (class IV) was the most common pattern of LN encountered in our study.
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Lupus Eritematoso Sistémico/diagnóstico , Adolescente , Niño , Manejo de la Enfermedad , Femenino , Humanos , Irak , Riñón/patología , Masculino , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
The trimolter mutants of Bombyx mori have four instead of five larval instars of normal tetramolters. Here, we show that the tetramolter was induced in the recessive trimolter European No.7 mutant (rt-E7) by application of either the juvenile hormone analog (JHA) or 20-hydroxyecdysone (20E). However, treatments with JHA or 20E did not change the number of larval instars of the dominant trimolter Si Chuan mutant (DT-SC). Krüppel-homolog 1 (Kr-h1) is an early JH-response gene that mediates the anti-metamorphic action of JH. In the wing disc of tetramolter B. mori, Kr-h1 RNAs decreased shortly after ecdysis to the fifth instar, while pupal specifier gene, Broad Complex Z1 (BR-Z1) RNAs slightly increased and coincided with the onset of metamorphic competence of wing discs. Analysis of the developmental profile of Kr-h1 in the wing disc of rt-E7 showed that its transcript slightly increased from 12 to 24 h and gradually decreased between 24 and 72 h in the fourth (last) larval instar, while Kr-h1 mRNA decreased rapidly between 12 and 72 h in DT-SC. In addition, the expression of BR-Z1 in DT-SC during the early fourth (last) larval instar is relatively higher than that in rt-E7. These results indicated that the occurrence of pupal commitment of the wing disc in DT-SC was much earlier than that in rt-E7. In the early fourth larval instar of rt-E7, feeding on 20E or treatments with exogenous JHA caused up-regulation of Kr-h1, suppressed premature induction of BR-Z1, and then induced an additional larval instar. By contrast, in DT-SC mutant, since pupal commitment immediately occurred after third ecdysis, precocious metamorphosis was not successfully rescued. The results suggest that Kr-h1 and BR-Z1 involved in the prevention of precocious metamorphosis in recessive trimolter mutants by application of 20E and JHA. The result indicated that Kr-h1 and BR-Z1 expression reflected larval-pupal transition of the recessive trimolter of B. mori.