[Efficacy analysis of letrozole combined with gonadotropin-releasing hormone antagonists in patients with high risk of ovarian hyperstimulation syndrome undergoing total embryo freezing].

Objective: To investigate the clinical efficacy of letrozole combined with gonadotropin-releasing hormone antagonists (GnRH-ant) in patients at high risk of ovarian hyperstimulation syndrome (OHSS) who underwent total embryo freezing after oocyte retrieval. Methods: A retrospective analysis was conducted on 348 female patients who underwent in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) at the Reproductive and Genetic Hospital of the First Affiliated Hospital of Zhengzhou University between January and July 2023. Due to their high risk of OHSS, these patients canceled fresh embryo transfer and opted for total embryo freezing. Based on patients' preferences, those who received GnRH-ant and letrozole after oocyte retrieval were categorized as the intervention group (164 cases), while those who did not receive these medications were categorized as the control group (184 cases). The first luteal phase after oocyte retrieval, OHSS grading, ovarian volume, and estradiol (E2) levels were evaluated in both groups. A multivariate logistic regression model was used to analyze factors related to moderate-to-severe OHSS among patients at high risk of OHSS who underwent total embryo freezing after oocyte retrieval. Results: The age of the intervention and control groups was (29.3±3.8) and (29.4±4.1) years, respectively (P=0.821). The duration of the first luteal phase post-oocyte retrieval was shorter in the intervention group [(7.16±1.39) days] compared to that in the control group [(13.88±2.11) days] (P<0.001). The incidences of mild, moderate, and severe OHSS in the intervention group were 75.0% (123 cases), 23.8% (39 cases), and 1.2% (2 cases), respectively, whereas in the control group they were 12.5% (23 cases), 60.9% (112 cases), and 26.6% (49 cases) (P<0.001). E2 levels on the 2nd and 6th days after oocyte retrieval [M(Q1,Q3)] in the intervention group were 1 520.0 (1 213.8, 1 884.8) and 108.5 (45.6, 218.0) ng/L, respectively, which were statistically significantly lower than those in the control group [1 666.0 (508.8, 1 702.0) ng/L] and [1 761.0 (826.0, 2 546.5) ng/L] (P<0.001). The abdominal cavity effusion in the intervention group [M(Q1,Q3)] were 19.5 (0, 30) and 0 mm, statistically significantly less than those in the control group [46.0 (0, 61.0) mm] and [54.5 (0, 69.5) mm] (P<0.001). On the 6th day after oocyte retrieval, the bilateral ovarian volumes in the intervention group were smaller than those in the control group (P<0.001). Multivariate logistic regression analysis indicated that no combined treatment with letrozole and GnRH-ant was a risk factor of moderate to severe OHSS. The risk of developing moderate to severe OHSS in the control group was 35.312 times higher than that in the intervention group (OR=35.312, 95%CI: 17.488-71.300). Conclusions: The administration of letrozole combined with GnRH-ant post-oocyte retrieval in patients at high risk of OHSS can prevent the occurrence of moderate-to-severe OHSS, shorten the first luteal phase, accelerate the reduction of serum E2 levels, and promote the recovery of ovarian volume and absorption of abdominal fluid.

Measurements of Normalized Differential Cross Sections of Inclusive η Production in e

Using data samples collected with the BESIII detector operating at the BEPCII storage ring, the cross section of the inclusive process e^{+}e^{-}→η+X, normalized by the total cross section of e^{+}e^{-}→hadrons, is measured at eight center-of-mass energy points from 2.0000 to 3.6710 GeV. These are the first measurements with momentum dependence in this energy region. Our measurement shows a significant discrepancy compared to the existing fragmentation functions. To address this discrepancy, a new QCD analysis is performed at the next-to-next-to-leading order with hadron mass corrections and higher twist effects, which can explain both the established high-energy data and our measurements reasonably well.

First Study of Antihyperon-Nucleon Scattering Λ[over ¯]p→Λ[over ¯]p and Measurement of Λp→Λp Cross Section.

Using (10.087±0.044)×10^{9} J/ψ events collected with the BESIII detector at the BEPCII storage ring, the processes Λp→Λp and Λ[over ¯]p→Λ[over ¯]p are studied, where the Λ/Λ[over ¯] baryons are produced in the process J/ψ→ΛΛ[over ¯] and the protons are the hydrogen nuclei in the cooling oil of the beam pipe. Clear signals are observed for the two reactions. The cross sections in -0.9≤cosθ_{Λ/Λ[over ¯]}≤0.9 are measured to be σ(Λp→Λp)=(12.2±1.6_{stat}±1.1_{syst}) and σ(Λ[over ¯]p→Λ[over ¯]p)=(17.5±2.1_{stat}±1.6_{syst}) mb at the Λ/Λ[over ¯] momentum of 1.074 GeV/c within a range of ±0.017 GeV/c, where the θ_{Λ/Λ[over ¯]} are the scattering angles of the Λ/Λ[over ¯] in the Λp/Λ[over ¯]p rest frames. Furthermore, the differential cross sections of the two reactions are also measured, where there is a slight tendency of forward scattering for Λp→Λp, and a strong forward peak for Λ[over ¯]p→Λ[over ¯]p. We present an approach to extract the total elastic cross sections by extrapolation. The study of Λ[over ¯]p→Λ[over ¯]p represents the first study of antihyperon-nucleon scattering, and these new measurements will serve as important inputs for the theoretical understanding of the (anti)hyperon-nucleon interaction.

A pulsar in a binary with a compact object in the mass gap between neutron stars and black holes.

Some compact objects observed in gravitational wave events have masses in the gap between known neutron stars (NSs) and black holes (BHs). The nature of these mass gap objects is unknown, as is the formation of their host binary systems. We report pulsar timing observations made with the Karoo Array Telescope (MeerKAT) of PSR J0514-4002E, an eccentric binary millisecond pulsar in the globular cluster NGC 1851. We found a total binary mass of 3.887 ± 0.004 solar masses (M⊙), and multiwavelength observations show that the pulsar's binary companion is also a compact object. The companion's mass (2.09 to 2.71 M⊙, 95% confidence interval) is in the mass gap, indicating either a very massive NS or a low-mass BH. We propose that the companion formed in a merger between two earlier NSs.

Observation of a Vector Charmoniumlike State at 4.7 GeV/c

Using data samples with an integrated luminosity of 5.85 fb^{-1} collected at center-of-mass energies from 4.61 to 4.95 GeV with the BESIII detector operating at the BEPCII storage ring, we measure the cross section for the process e^{+}e^{-}→K^{+}K^{-}J/ψ. A new resonance with a mass of M=4708_{-15}^{+17}±21 MeV/c^{2} and a width of Γ=126_{-23}^{+27}±30 MeV is observed in the energy-dependent line shape of the e^{+}e^{-}→K^{+}K^{-}J/ψ cross section with a significance over 5σ. The K^{+}J/ψ system is also investigated to search for charged charmoniumlike states, but no significant Z_{cs}^{+} states are observed. Upper limits on the Born cross sections for e^{+}e^{-}→K^{-}Z_{cs}(3985)^{+}/K^{-}Z_{cs}(4000)^{+}+c.c. with Z_{cs}(3985)^{±}/Z_{cs}(4000)^{±}→K^{±}J/ψ are reported at 90% confidence levels. The ratio of branching fractions {[B(Z_{cs}(3985)^{+}→K^{+}J/ψ)]/B[Z_{cs}(3985)^{+}→(D[over ¯]^{0}D_{s}^{*+}+D[over ¯]^{*0}D_{s}^{+})]} is measured to be less than 0.03 at 90% confidence level.

[Analysis of the efficacy and influencing factors of sodium channel blockers in the treatment of focal epilepsy in infants under 6 months of age].

Objective: To analyze the efficacy and safety of the sodium channel blockers (SCB) antiseizure medication in the treatment of focal epilepsy in infants under 6 months of age. Methods: This was a case series study. Infants with focal epilepsy with onset within 6 months of age and treated with SCB attending the Department of Neurology of Beijing Children's Hospital from June 2016 to April 2022 were collected. The clinical data, auxiliary examinations, SCB application, efficacy, adverse reactions, and prognosis were analyzed retrospectively. Patients were grouped according to type of seizure and epileptic syndrome, age of onset and etiology. Chi square test and Fisher exact test were used to analyze the differences between groups statistically. Results: A total of 118 infants were enrolled, 65 males and 53 females, with an age of epilepsy onset of 56 (4, 114) days. Developmental and epileptic encephalopathy was diagnosed in 60 infants, 39 had self-limited neonatal and (or) infantile epilepsy, and 19 had non-syndromic focal epilepsy. Application of SCB: 106 used oxcarbazepine, 2 used lacosamide, 9 switched from oxcarbazepine to lacosamide or a combination of 2 SCB, and 1 used oxcarbazepine, lacosamide, and lamotrigine successively; oxcarbazepine was the first choice in 46 cases. The age at which SCB was applied was 103 (53, 144) days. The children were followed up for 6 months to 6 years. SCB was effective in 89 cases (75.4%), including 70 cases (59.3%) who achieved seizure freedom. The seizure-free rate was higher in the focal epilepsy only group than in the group with other seizure types (64.4% (65/101) vs. 4/17, χ²=9.99, P<0.05). The responder and seizure-free rates were all higher in the group with the onset age of >3-6 months than the group >1-3 months (84.4% (38/45) vs. 62.5% (20/32), 73.3% (33/45) vs. 46.9% (15/32), χ²=4.85 and 5.58, both P<0.05). With the exception of variants in the PRRT2 gene, those with variants in sodium or potassium channels had higher responder and seizure-free rates than those with variants in other genes(86.2% (25/29) vs. 45.5% (10/22), 62.1% (18/29) vs. 22.7% (5/22), χ²=9.65 and 7.82,both P<0.05). The most common adverse event was transient hyponatremia, which happened in 66 cases (55.9%). There were 9 cases of rash, which subsided in 6 cases after discontinuing oxcarbazepine and switching to lacosamide, and 7 cases of electrocardiogram abnormalities, which improved after withdrawing oxcarbazepine and changing to lacosamide in 1 case. Conclusion: SCB are effective and tolerable in the treatment of focal epilepsy in infants under 6 months of age, with better efficacy in patients with genetic variants of the sodium or potassium channel, focal seizures only, and seizure onset >3-6 months of age.

Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions.

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510 GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510 GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02

[Clinical characteristics and short-term prognosis of 22 cases with SARS-CoV-2 infection associated acute encephalopathy].

Objective: To investigate the clinical features and short-term prognosis of patients with SARS-CoV-2 infection associated acute encephalopathy (AE). Methods: Retrospective cohort study. The clinical data, radiological features and short-term follow-up of 22 cases diagnosed with SARS-CoV-2 infection associated AE in the Department of Neurology, Beijing Children's Hospital from December 2022 to January 2023 were retrospectively analyzed. The patients were divided into cytokine storm group, excitotoxic brain damage group and unclassified encephalopathy group according to the the clinicopathological features and the imaging features. The clinical characteristics of each group were analyzed descriptively. Patients were divided into good prognosis group (≤2 scores) and poor prognosis group (>2 scores) based on the modified Rankin scale (mRS) score of the last follow-up. Fisher exact test or Mann-Whitney U test was used to compare the two groups. Results: A total of 22 cases (12 females, 10 males) were included. The age of onset was 3.3 (1.7, 8.6) years. There were 11 cases (50%) with abnormal medical history, and 4 cases with abnormal family history. All the enrolled patients had fever as the initial clinical symptom, and 21 cases (95%) developed neurological symptoms within 24 hours after fever. The onset of neurological symptoms included convulsions (17 cases) and disturbance of consciousness (5 cases). There were 22 cases of encephalopathy, 20 cases of convulsions, 14 cases of speech disorders, 8 cases of involuntary movements and 3 cases of ataxia during the course of the disease. Clinical classification included 3 cases in the cytokine storm group, all with acute necrotizing encephalopathy (ANE); 9 cases in the excitotoxicity group, 8 cases with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and 1 case with hemiconvulsion-hemiplegia syndrome; and 10 cases of unclassified encephalopathy. Laboratory studies revealed elevated glutathione transaminase in 9 cases, elevated glutamic alanine transaminase in 4 cases, elevated blood glucose in 3 cases, and elevated D-dimer in 3 cases. Serum ferritin was elevated in 3 of 5 cases, serum and cerebrospinal fluid (CSF) neurofilament light chain protein was elevated in 5 of 9 cases, serum cytokines were elevated in 7 of 18 cases, and CSF cytokines were elevated in 7 of 8 cases. Cranial imaging abnormalities were noted in 18 cases, including bilateral symmetric lesions in 3 ANE cases and "bright tree appearance" in 8 AESD cases. All 22 cases received symptomatic treatment and immunotherapy (intravenous immunoglobulin or glucocorticosteroids), and 1 ANE patient received tocilizumab. The follow-up time was 50 (43, 53) d, and 10 patients had a good prognosis and 12 patients had a poor prognosis. No statistically significant differences were found between the two groups in terms of epidemiology, clinical manifestations, biochemical indices, and duration of illness to initiate immunotherapy (all P>0.05). Conclusions: SARS-CoV-2 infection is also a major cause of AE. AESD and ANE are the common AE syndromes. Therefore, it is crucial to identify AE patients with fever, convulsions, and impaired consciousness, and apply aggressive therapy as early as possible.

[Clinical features of 6 children with uridine-responsive developmental epileptic encephalopathy 50 caused by CAD gene variants].

Objective: To analyze the clinical features of children with uridine responsive developmental epileptic encephalopathy 50 (DEE50) caused by CAD gene variants. Methods: A retrospective study was conducted on 6 patients diagnosed with uridine-responsive DEE50 caused by CAD gene variants at Beijing Children's Hospital and Peking University First Hospital from 2018 to 2022. The epileptic seizures, anemia, peripheral blood smear, cranial magnetic resonance imaging (MRI), visual evoked potential (VEP), genotype features and the therapeutic effect of uridine were descriptively analyzed. Results: A total of 6 patients, including 3 boys and 3 girls, aged 3.5(3.2,5.8) years, were enrolled in this study. All patients presented with refractory epilepsy, anemia with anisopoikilocytosis and global developmental delay with regression. The age of epilepsy onset was 8.5 (7.5, 11.0) months, and focal seizures were the most common seizure type (6 cases). Anemia ranged from mild to severe. Four patients had peripheral blood smears prior to uridine administration, showing erythrocytes of variable size and abnormal morphology, and normalized at 6 (2, 8) months after uridine supplementation. Two patients suffered from strabismus, 3 patients had VEP examinations, indicating of suspicious optic nerve involvement, and normal fundus examinations. VEP was re-examined at 1 and 3 months after uridine supplementation, suggesting significant improvement or normalization. Cranial MRI were performed at 5 patients, demonstrating cerebral and cerebellar atrophy. They had cranial MRI re-examined after uridine treatment with a duration of 1.1 (1.0, 1.8) years, indicating significant improvement in brain atrophy. All patients received uridine orally at a dose of 100 mg/(kg·d), the age at initiation of uridine treatment was 1.0 (0.8, 2.5) years, and the duration of treatment was 2.4 (2.2, 3.0) years. Immediate cession of seizures was observed within days to a week after uridine supplementation. Four patients received uridine monotherapy and were seizure free for 7 months, 2.4 years, 2.4 years and 3.0 years respectively. One patient achieved seizure free for 3.0 years after uridine supplementation and had discontinued uridine for 1.5 years. Two patients were supplemented with uridine combined with 1 to 2 anti-seizure medications and had a reduced seizure frequency of 1 to 3 times per year, and they had achieved seizure free for 8 months and 1.4 years respectively. Conclusions: The clinical manifestations of DEE50 caused by CAD gene variants present a triad of refractory epilepsy, anemia with anisopoikilocytosis, and psychomotor retardation with regression, accompanied by suspected optic nerve involvement, all of which respond to uridine treatment. Prompt diagnosis and immediate uridine supplementation could lead to significant clinical improvement.

[Clinical analysis of 4 acute ischemic stroke children treated with endovascular thrombectomy].

Objective: To assess the feasibility of endovascular thrombectomy (EVT) for the treatment of acute ischemic stroke (AIS) in children. Methods: Clinical data and follow-up information of 4 AIS children who received EVT in the Department of Intervention & Hemangioma at the Children's Hospital of the Capital Institute of Pediatrics from December 2020 to June 2021 were collected retrospectively. The vascular recanalization after EVT was assessed by the modified thrombolysis in cerebral infarction (mTICI) score. Efficacy outcomes were assessed with initial and postprocedural Pediatric National Institutes of Health Stroke Scale (PedNIHSS) score, and the modified Rankin scale (mRS) score at 3 and 6 months after treatment. Safety assessments included perioperative complications and intracranial hemorrhage post-treatment. Results: A total of 5 EVT treatment were performed on 4 children with AIS, of whom 3 were male. The age of onset was 4.6, 13.8, 7.8, 8.0, 8.9 years, respectively. The time from symptom onset to initiation of EVT was 19.0, 25.0, 22.0, 4.0, 16.5 hours, respectively and all patients achieved successful recanalization of the vessel after EVT (mTICI≥2b). The PedNIHSS score was 39, 14, 25, 39, 24 before treatment and decreased to 8, 1, 12, 39, 5 at discharge. All the procedures were performed with no perioperative complications. Only 1 patient with congenital heart disease had a recurrent AIS with malignant brain oedema and brain hernia. Although the occluded vessels were successfully recanalized,the symptoms were not improved and this patient died after treatment abandonment. The other 3 patients achieved good recovery at 6 months postoperatively. The mRS score of 3 patients was 3, 1, 2 at 3 months after EVT and decreased to 2, 1, 1 at 6 months. Conclusion: EVT treatment may be feasible and safe for pediatric AIS due to large vessel occlusion even when the treatment was initiated 6 hours post stroke, but children with heart disease may have a dismal prognosis.

[Analysis of clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion].

Objective: To investigate the clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion. Methods: The patients (n=10) with 16p11.2 microdeletion found in children with epilepsy treated in Beijing Children's Hospital Affiliated to Capital Medical University from January 2018 to January 2021 were collected. The clinical manifestations, gene variations and prognosis were analyzed retrospectively. Results: A total of 10 children's data were collected, including 5 male and 5 female. The onset age of epilepsy was 4.5 (4.1,5.0) months. Regarding the seizure types, 7 cases had focal seizures with secondary generalization, 2 cases had generalized seizures, and 1 case had tonic seizures and spasms. Nine cases had cluster seizure attacks and 3 cases had status epilepticus. Seven cases had focal or multifocal epileptiform discharges in interictal electroencephalogram (EEG), 3 cases had borderline or normal EEG. Brain magnetic resonance imaging showed polymicrogyria in 1 case, paraventricular leukomalacia in 1 case, delayed myelination of white matter in 3 cases, and no obvious abnormalities in the other 5 cases. The patients were followed up for 0.5-3.5 years, with 1-3 kinds of antiepileptic drugs taken orally. The case with polymicrogyria still had seizures, however the other 9 cases had seizures controlled. The age of the last seizure attack was 8 (6, 12) months. There were 6 cases with mental and motor developmental delay before epilepsy onset. During the follow-up, 7 cases were retarded to varying degrees, while 3 cases had normal development. Regarding the genetic detection methods, 7 cases underwent whole exome sequencing, 2 cases underwent whole genome copy number variation detection, and 1 case underwent whole genome sequencing. The length of the 16p11.2 deletion in 10 cases ranged from 525 to 951 kb, and all contained the PRRT2 gene intact. Six cases were de novo variants, 1 case was inherited from the mother who had a history of convulsions in early childhood, and the source of variant was not verified in 3 cases, none of whose parents had relevant phenotype. Conclusions: The epilepsy associated with 16p11.2 microdeletion is mainly induced by the heterozygous deletion of PRRT2 gene in this region, however the phenotype is usually severe, and often combined with developmental and epileptic encephalopathy. Detection of copy number variation should be emphasized in children whose etiology is considered genetic but second-generation sequencing result is negative.

Chondroitin Sulfate Enhances Proliferation and Migration via Inducing ß-Catenin and Intracellular ROS as Well as Suppressing Metalloproteinases through Akt/NF-κB Pathway Inhibition in Human Chondrocytes.

BACKGROUND: Chondroitin sulfate (CS) is found in humans' cartilage, bone, cornea, skin, and arterial wall. It consists of the foundation substance in the extracellular matrix (ECM) of connective tissue. The oral supplement form of CS is clinically used in treating osteoarthritis (OA). METHODS: Cell migration was observed by the transwell assay. The EMT, Akt/IKK/IκB pathways, TIMPs, collagen and MMPs in cell lysate were determined by Western blotting. The expression of MMP activity was determined by gelatin zymography. The production of reactive oxygen species (ROS) was determined by using a fluorescence spectrophotometer. RESULTS: In the current report, we demonstrated that CS can increase the cell proliferation and migration of chon-001 chondrocytes. Treatment with CS induced the epithelial-mesenchymal transition and increased the expression of type II collagen and TIMP-1/TIMP2 and inhibited the expressions and activities of metalloproteinase-9 (MMP-9) and metalloproteinase-2 (MMP-2). The phosphorylation of Akt, IκB kinase (IKK), IκB and p65 was decreased by CS. CS treatment resulted in ß-catenin production and XAV939, a ß-catenin inhibitor, and inhibited the cell proliferation by CS treatment. In addition, also significantly induced intracellular ROS generation. Treatment with antioxidant propyl gallate blocked cell migration induced by CS. CONCLUSION: We demonstrated that CS induced cell proliferation and migration of chondrocytes by inducing ß-catenin and enhancing ROS production. Moreover, our studies demonstrated that CS can increase the activity of chondrocytes and help patients with osteoarthritis to restore cartilage function.

Intravenous tissue plasminogen activator for acute ischemic stroke in patients with renal dysfunction.

OBJECTIVE: This study used the Taiwan Stroke Registry data to evaluate the efficacy and safety of intravenous tissue plasminogen activator (tPA) in treating acute ischemic stroke in patients with renal dysfunction. DESIGN: We identified 3525 ischemic stroke patients and classified them into two groups according to the estimated glomerular filtration rate (eGFR) at the emergency department: ≥60, and <60 ml/min/1.73 m2 or on dialysis and by the propensity score from August 2006 to May 2015. The odds ratio of poor functional outcome (modified Rankin Scale ≥2) was calculated for patients with tPA treatment (N = 705), compared to those without tPA treatment (N = 2820), by eGFR levels, at 1, 3 and 6 months after ischemic stroke. We also evaluated the risks of intracerebral hemorrhage, upper gastrointestinal bleeding, mortality, between the two groups by eGFR levels. RESULTS: Among patients with eGFR levels of <60 ml/min/1.73 m2, tPA therapy reduced the odds ratio of poor functional outcome to 0.60 (95% confidence interval = 0.42-0.87) at 6 months after ischemic stroke. The tPA therapy was not associated with increased overall risk of upper gastrointestinal bleeding, but with increased risk of intracerebral hemorrhage. The low eGFR was not a significant risk factor of intracerebral hemorrhage among ischemic stroke patients receiving tPA treatment. CONCLUSIONS: tPA for acute ischemic stroke could improve functional outcomes without increasing the risks of upper gastrointestinal bleeding for patients with or without renal dysfunction. The low eGFR was not a significant risk factor for intracerebral hemorrhage among patients receiving tPA treatment.

Protein kinase C signalling involved in prothoracicotropic hormone-stimulated prothoracic glands in the silkworm, Bombyx mori.

In the present study, the participation of protein kinase C (PKC) signalling in prothoracicotropic hormone (PTTH)-stimulated ecdysteroidogenesis in Bombyx prothoracic glands (PGs) is demonstrated and characterized. PTTH stimulated phosphorylation of a 37-kDa protein in Bombyx PGs both in vitro and in vivo, as recognized by a PKC substrate antibody. Treatment with either A23187 or thapsigargin also stimulated this 37-kDa protein phosphorylation. PTTH-stimulated phosphorylation of the 37-kDa protein was markedly attenuated in the absence of Ca2+ . The phospholipase C (PLC) inhibitor, U73122, greatly inhibited PTTH-stimulated phosphorylation of this protein, indicating the involvement of Ca2+ and PLC. A mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor (U0126), a phosphoinositide 3-kinase (PI3K) inhibitor (LY294002) and a chemical activator of adenosine 5'-monophosphate-activated protein kinase (AMPK) (5-aminoimidazole-4-carboxamide-1-ß-d-ribofuranoside) did not affect PTTH-stimulated phosphorylation of the 37-kDa protein, implying that ERK and PI3K/AMPK are not the upstream signalling pathways for PKC-dependent protein phosphorylation. The mitochondrial oxidative phosphorylation inhibitors (the uncoupler carbonyl cyanide p-trifluoromethoxyphenylhydrazone and diphenylene iodonium) inhibited PTTH-stimulated phosphorylation of the 37-kDa protein, indicating its redox regulation. Treatment with PKC inhibitors (either calphostin C, chelerythrine C or rottlerin) reduced PTTH-stimulated phosphorylation of the 37-kDa protein. PTTH-stimulated ecdysteroidogenesis was also inhibited by treatment with rottlerin, thus further confirming participation of PKC-dependent phosphorylation in PTTH signalling. From these results, we demonstrated that redox-regulated PTTH-stimulated PKC signalling is involved in ecdysteroid secretion in Bombyx PGs.