Disrupted intrinsic connectivity of the periaqueductal gray in patients with functional dyspepsia: A resting-state fMRI study

BACKGROUND

Functional dyspepsia (FD) is a common functional gastrointestinal disorder. Accumulating evidence suggests the crucial role of central nervous system in the development and maintenance of FD. In particular, periaqueductal gray (PAG) has demonstrated an important role in modulation of pain and emotion, which may be related to FD. However, the study of the PAG in FD is still limited. This study aimed to assess intrinsic connectivity of the PAG in FD patients.

METHODS

Resting-state functional magnetic imaging (fMRI) data were collected from 66 FD patients and 42 healthy controls (HCs). Functional connectivity analysis was performed to investigate the PAG connectivity pattern differences between the patients and HCs. We then examined the relationships between functional connectivity within the PAG networks and FD symptoms.

KEY RESULTS

Compared to HCs, patients had increased PAG connectivity with the insula, and decreased PAG connectivity with the orbitofrontal cortex (OFC), dorsolateral prefrontal cortex (dlPFC) and hippocampus/parahippocampus (HIPP/paraHIPP). There were positive correlations between disease duration and PAG connectivity with the putamen and supplementary motor area (SMA), and positive correlations between symptom severity and PAG connectivity with the insula. FD patients with high level of anxiety and depression had altered PAG connectivity with the anterior cingulate cortex (ACC), precuneus, dlPFC and caudate, compared to other patients.

CONCLUSIONS & INFERENCES

These findings indicate that abnormal intrinsic network of the PAG might be associated with abnormality of pain processing and disruption of emotion processing in FD patients. Our study further complements neuroimaging findings about FD.

Spatial summation of the short-term plasticity of a pair of organic heterogeneous junctions

Short-term plasticity of a pair of organic heterogeneous junctions could be linearly summed from those of the two sources.

LncRNA H19 is overexpressed in glioma tissue, is negatively associated with patient survival, and promotes tumor growth through its derivative miR-675

OBJECTIVE

Glioma is one of the most common and invasive tumors of the central nervous system. Long non-coding (lnc) RNAs are involved in many cancers, but their function and mechanism in glioma remain largely unknown. We wished to delineate the role of lncRNA H19 and its derivative miR-675 in this tumor.

PATIENTS AND METHODS

Using qPCR, we compared expression of lncRNA H19 in 35 specimens of glioma vs control tissue, and in two glioma cell lines U251 and U87 vs Normal Human Astrocyte (NHA) cells. Cell proliferation was evaluated after shRNA silencing of lncRNA H19 in glioma cell lines. The role of miR-675 was tested using antagomir and the mimic.

RESULTS

LncRNA H19 was overexpressed in glioma tissue and cell lines. In tissue, higher expression levels were observed in more advanced stages of the tumor. Furthermore, lncRNA H19 was negatively associated with patient survival time. In cell culture experiments, silencing of lncRNA H19 diminished proliferation of glioma cell lines. These effects of lncRNA H19 appeared to be intermediated by miR-675. The latter was overexpressed in glioma tissue and was negatively associated with patient survival. Supporting the involvement of miR-675, its antagomir decreased proliferation of glioma cell lines, whereas its mimic increased proliferation of NHA cells.

CONCLUSIONS

LncRNA H19 is overexpressed in glioma tissue, and is positively associated with the tumor grade and negatively associated with patient survival. In cell culture studies, lncRNA H19 promotes glioma cell proliferation. These tumor-promoting effects of lncRNA H19 appear to be mediated by miR-675.

The Theoretical Construction of a Classification of Clinical Somatic Symptoms in Psychosomatic Medicine Theory

Objective

This article adopts the perspective of psychosomatic medicine to present and test a theoretical model of the classification of clinical somatic symptoms. The theoretical model consists of four dimensions: emotional somatic symptoms, biological somatic symptoms, imaginative somatic symptoms, and cognitive somatic symptoms.

Method

A clinical somatic symptom classification scale was developed according to the theoretical model. A total of 542 participants completed the clinical somatic symptoms classification scale. The data were analyzed using exploratory and confirmatory factor analyses.

Results

The results confirmed the theoretical model. The analyses found that the proposed theoretical structure of the scale was good, as indicated by factor loadings and fit indices, and that the scale had good reliability and construct validity.

Conclusions

Based on the interpretation of the clinical symptoms of psychosomatic medicine, the treatment of chronic non-infectious diseases includes at least three dimensions: the first is the etiological treatment, the second is the pathophysiological and pathopsychological dimension, and the third is symptomatic treatment. The unified psychosomatic point of view and diverse clinical thinking modes are aimed at identifying different classes of somatic symptoms and important prerequisites for the treatment of these symptoms. We registered the study with the Chinese Clinical Trial Registry and it was approved by the West China Hospital, Sichuan University ethics committee. Trial registration: The registration number is ChiCTR-OCS-14004632 (time: 2014-05-12).

[The contrast analysis of endoscopic thyroidectomy by complete areola approach and conventional open thyroidectomy]

Objective:To compare the clinical efficacy between the endoscopic thyroidectomy by complete areola approach and the conventional open thyroidectomy.Method:One hundred and twenty-one cases of endoscopic thyroidectomy by complete areola approach or conventional open thyroidectomy patients were reviewed retrospectively, whose operation time, median blood lose, volume of postoperative drainage, incision scar formation rate and patient satisfaction were observed and compared.Result:There were obvious advantages in the median blood lose, volume of postoperative drainage, incision scar formation rate and patient satisfaction in the group of endoscopic thyroidectomy by complete areola approach comparing conventional open thyroidectomy. The difference was statistically significant（P <0.05）.Conclusion:The method of endoscopic thyroidectomy by complete areola approach is obviously better , which has many advantages, such as Less bleeding, less volume of wound drainage and small skin incision scar. The patients were satisfied with the treatment.It is worthy of clinical application.

Life events, anxiety, social support, personality, and alexithymia in female patients with chronic pain: A path analysis

INTRODUCTION

This study sought to identify a model that explains the relationship between psychosocial factors and chronic pain in female patients, and to explore all of these constructs in a single study and provide a more holistic examination of the overall psychosocial factors that female patients with chronic pain encounter.

METHODS

Female patients with chronic pain (n = 147), aged 20-65 (M = 34.9 years, SD = 11.25), from an outpatient pain clinic completed a cross-sectional self-report questionnaire on anxiety, life events, personality, social support, and alexithymia. Data were analyzed by means of path analysis.

RESULTS

The direct effect of anxiety on female patients with chronic pain was greatest among all the paths. Personality and alexithymia led to chronic pain in female patients only indirectly, mediated by life events. The personality factors of neuroticism and extraversion were associated positively with social support, which had an indirect effect on the influence of life events on chronic pain. However, alexithymia was associated negatively with social support, which had an indirect effect on the influence of life events on chronic pain.

DISCUSSION

Our findings provide evidence that life events are a mediator in the relationship between personality, social support, alexithymia, and chronic pain in female patients.

Socs1 and Socs3 degrades Traf6 via polyubiquitination in LPS-induced acute necrotizing pancreatitis

Mechanisms involved in inflammatory development during acute pancreatitis (AP) are largely vague, especially in the transformation of acute edematous pancreatitis (AEP) into acute necrotizing pancreatitis (ANP). This current study aims to investigate the functions of Traf6 in different AP models in vitro and in vivo, and to identify the possible regulatory mechanism in the progression of inflammation from mild to severe. Our data revealed that the level of Traf6 expression was significantly increased in the mild AP induced by caerulein, and the upregulation of Traf6 played a protective role in acinar cells against caerulein-induced apoptosis. In contrast, only Traf6 protein but not mRNA was downregulated in the severe ANP induced by combination treatment of caerulein and LPS. Mechanistic studies showed that LPS upregulated the levels of Socs1 and Socs3 expressions in acinar cells, Socs1 and Socs3 interacted Traf6 directly and degraded Traf6 protein via polyubiquitination, thereby counteracted the protective function of Traf6. In vivo study further showed that combination treatment of caerulein and LPS failed to induce an ANP model in the TLR4 knockout mice, and the level of Traf6 expression in the pancreatic tissues remained the same as that from the acute edematous pancreatitis (AEP) mouse. Taken together, our study reveals that Traf6 functioned as a protective factor in the progression of AP, and LPS-induced Socs1 and Socs3 exacerbate mild AP to severe AP, which provides evidence for developing a new therapeutic target to combat AP.

Chrysopa septempunctata (Neuroptera: Chrysopidae) Vitellogenin Functions Through Effects on Egg Production and Hatching

Vitellogenin (Vg) is a precursor of major egg storage protein, vitellin (Vt), and plays primary roles in reproduction of oviparous vertebrates and invertebrates. Chrysopa septempunctata Wesmael is an important and common predator of various insect pests. Here, we first cloned C. septempunctata Vg gene, CsVg. The complete CsVg cDNA was 5664 bp, which encodes an 1810-residues protein with a predicted molecular mass of 206.23 kDa. Expression profile revealed that CsVg mRNA first appeared on day 4 after emergence, maximally accumulated on day 10, and then declined gradually. RNAi mediated by injection of dsRNA depleted CsVg transcripts, significantly reduced egg-laying amount, and decreased egg hatching rate, suggesting that CsVg functions through effects on egg production and hatching in C. septempunctata.

Frequency-dependent learning achieved using semiconducting polymer/electrolyte composite cells

Frequency-dependent learning has been achieved using semiconducting polymer/electrolyte composite cells. The cells composed of polymer/electrolyte double layers realized the conventional spike-rate-dependent plasticity (SRDP) learning model. These cells responded to depression upon low-frequency stimulation and to potentiation upon high-frequency stimulation and presented long-term memory. The transition threshold θm from depression to potentiation varied depending on the previous stimulations. A nanostructure resembling a bio-synapse in its transport passages was demonstrated and a random channel model was proposed to describe the ionic kinetics at the polymer/electrolyte interface during and after stimulations with various frequencies, accounting for the observed SRDP.

The association and interaction analysis of hypertension and uric acid on cardiovascular autonomic neuropathy

BACKGROUND

The purpose of this study was to evaluate associations among hypertension (HTN) and uric acid (UA) with cardiovascular autonomic neuropathy (CAN), and to estimate the extent to which synergistic effects of HTN and UA affect the outcome in a Chinese population.

METHOD

We conducted a large-scale, population-based study to analyze the association and interaction of the two factors for CAN in a sample of 2092 Chinese people. Univariate and multiple linear regression (MLR) analysis were employed to detect these relationships. Interaction on an additive scale can be calculated by using the relative excess risk due to interaction (RERI), the proportion attributable to interaction (AP), and the synergy index (S).

RESULT

After adjusting for confounding factors, MLR showed that HTN was independently associated with CAN (P < 0.001). A significant interaction effect of UA and HTN on CAN was detected (P = 0.035; RETI = 1.483, 95 % CI 0.415-2.551; AP = 0.360, 95 % CI -0.043 to 0.76 and S = 1.908, 95 % CI 0.152-3.66).

CONCLUSION

Our findings suggest that HTN is independently and significantly associated with CAN and offer evidence to support the hypothesis that HTN and UA have interaction effects to influence the progression of CAN.

Influence of one-year neurologic outcome of treatment on newborns with moderate and severe hypoxic-ischemic encephalopathy by rhuEP0 combined with ganglioside (GM1)

OBJECTIVE

To observe the one-year neurologic prognostic outcome of newborns with moderate and severe hypoxic-ischemic encephalopathy (HIE) who received recombinant human erythropoietin (rhuEPO) combined with exogenous monosialotetrahexosylganglioside (GM1) treatment to provide new guidelines for clinical treatment.

PATIENTS AND METHODS

Seventy-six newborns with moderate and severe HIE were selected from February 2011 to February 2014 in our hospital. This study received the informed consent of our hospital's Ethics Committee and the newborns' guardians. The newborns were divided to an observation group (n = 34 cases) and a control group (n = 42 cases). All newborns underwent hypothermia and conventional treatment for their conditions. The control group received GMl treatment and observation group received rhuEPO combined with GMl treatment. The curative differences and neural behavior from these two groups were compared.

RESULTS

The excellent, efficient proportion and total effective rate of the newborns from the observation group were higher than the control group. The death rate, cerebral palsy and the invalid ratio of the newborns from the observation group were lower than that of the control group. Awareness, muscle tension, primitive reflex and increased intracranial pressure recovery time of the newborns in the observation group were less than those of the control group. The Neonatal Behavior Neurological Assessment (NBNA) score of both groups after the treatment of 7, 14 and 28 days were significantly higher and increased with time (p < 0.05). The MDI, PDI and DQ score of newborns from the two groups all increased after treatment of 3, 6 and 12 months than those of before, which increased with time (p < 0.05).

CONCLUSIONS

The rhuEPO + GMl treatment in newborns with HIE improves short-term clinical effects and long-term neurological symptoms.

Anatomically related gray and white matter alterations in the brains of functional dyspepsia patients

BACKGROUND

Previous studies summarized altered brain functional patterns in functional dyspepsia (FD) patients, but how the brain structural patterns are related to FD remains largely unclear. The objective of this study was to determine the brain structural characteristics in FD patients.

METHODS

Optimized voxel-based morphometry and tract-based spatial statistics were employed to investigate the changes in gray matter (GM) and white matter (WM) respectively in 34 FD patients with postprandial distress syndrome and 33 healthy controls based on T1-weighted and diffusion-weighted imaging. The Pearson's correlation evaluated the link among GM alterations, WM abnormalities, and clinical variables in FD patients. The optimal brain structural parameters for identifying FD were explored using the receiver operating characteristic curve.

KEY RESULTS

Compared to controls, FD patients exhibited a decrease in GM density (GMD) in the right posterior insula/temporal superior cortex (marked as pINS), right inferior frontal cortex (IFC), and left middle cingulate cortex, and an increase in fractional anisotropy (FA) in the posterior limb of the internal capsule, posterior thalamic radiation, and external capsule (EC). Interestingly, the GMD in the pINS was significantly associated with GMD in the IFC and FA in the EC. Moreover, the EC adjacent to the pINS provided the best performance for distinguishing FD patients from controls.

CONCLUSIONS & INFERENCES

Our results showed pINS-related structural abnormalities in FD patients, indicating that GM and WM parameters were not affected independently. These findings would lay the foundation for probing an efficient target in the brain for treating FD.

Clinical risk model assessment for cardiovascular autonomic dysfunction in the general Chinese population

BACKGROUND

The aim of this study was to evaluate the prevalence of cardiovascular autonomic (CA) dysfunction in the general Chinese population (instead of focusing on only patients with diabetes) and to develop a clinical risk model for the disease.

METHODS AND MATERIALS

We evaluated CA dysfunction prevalence in a dataset based on a population sample consisting of 2,092 individuals. Clinical risk models were derived from exploratory sets using multiple logistic regression analysis. The performance of the clinical risk models was tested in the validation sets.

RESULTS

CA dysfunction prevalence was 18.50% in the general Chinese population, while the prevalence was 24.14% in individuals aged ≥60 years. Its prevalence was 31.17, 24.69, and 21.26% in patients with diabetes, and hypertensive, and metabolic syndrome populations, respectively. Finally, we developed clinical risk models involving seven risk factors. The mean area under the receiver-operating curve was 0.758 (95% CI 0.724-0.793) for these models. The mean sensitivity and specificity of the clinical risk models was 75.0 and 66.2%, respectively.

CONCLUSION

CA dysfunction prevalence was high in the general Chinese population, and its prevalence was more frequent in individuals with diabetes, and hypertensive, and metabolic syndrome. Clinical risk models with a high value for predicting CA dysfunction were developed. CA dysfunction has become a major public health problem in China that requires strategies aimed at the prevention and treatment of the disease.

A single-centre, open-label, prospective study of an initially short-term intensified dosing regimen of enteric-coated mycophenolate sodium with reduced cyclosporine A exposure in Chinese live-donor kidney transplant recipients

AIMS

The nephrotoxicity of cyclosporine A (CsA) accounts for dysfunction of kidney allografts in the clinic. Short-term intensified dosing using enteric-coated mycophenolate sodium (EC-MPS) may facilitate CsA sparing after kidney transplantation without compromising safety.

METHODS

In a 12-month, single-centre open-label prospective trial, 180 de novo live-donor kidney transplant recipients at low-immunological risk were randomised to a low-dose cyclosporine group which received a low dose of cyclosporine, short-term intensified EC-MPS dosing (2160 mg/day to week 6, 1440 mg/day thereafter) and corticosteroids or a standard-dose cyclosporine group which received a standard dose of cyclosporine, standard EC-MPS dosing (1440 mg/day) and corticosteroids. The primary end-point [treatment failure including biopsy-proven acute rejection (BPAR), graft loss, death], secondary end-point and adverse events were monitored.

RESULTS

The primary end-point (treatment failure) occurred in 13.3% (12/90) of the low-dose cyclosporine group and 16.7% (15/90) of the standard-dose cyclosporine group (p = 0.53) (difference -3.4%, 95% confidence interval -11.7% to 7.5%, based on a noninferiority margin of 20%). BPAR occurred in 11.1% and 13.3% of patients in the low-dose cyclosporine group and standard-dose cyclosporine group, respectively (p = 0.65). The estimated glomerular filtration rate, as calculated by the Cockcroft-Gault formula, was similar at 12 months after transplantation (low-dose cyclosporine group 63 ± 19 ml/min/1.73 m(2) and standard-dose cyclosporine group 59 ± 15 ml/min/1.73 m(2) ; p = 0.43). The levels of serum creatinine and occurrence of adverse events between the two groups were not statistically different.

CONCLUSIONS

A regimen of early intensified EC-MPS dosing permits low-dose cyclosporine in live-donor kidney transplant patients at low-immunological risk without compromising efficacy at 12 months' follow-up.

Cerebral responses to puncturing at different acupoints for treating meal-related functional dyspepsia

BACKGROUND

To investigate the similarities and differences in cerebral responses to puncturing at different acupoints for treating meal-related functional dyspepsia (FD).

METHODS

Twenty right-handed FD patients were enrolled and randomized divided into two groups. Each patient received 20 sessions' electro-acupuncture treatment. The acupoints used in Group A were four acupoints on the Stomach Meridian, and the acupoints used in Group B were four acupoints on the Gallbladder Meridian. PET-CT scans were performed before and after acupuncture treatment to record the changes of cerebral glycometabolism.

KEY RESULTS

After treatment, the dyspepsia symptoms and the quality of life (QOL) of the patients in each group were significantly improved (p < 0.05) and there was insignificant difference in efficacy between the two groups (p > 0.05). In Group A, deactivation in brainstem, bilateral anterior cingulate cortex (ACC) and cerebellum, left superior medial frontal gyrus, orbital frontal cortex (OFC), and thalamus, etc., and activation in bilateral middle cingulate cortex (MCC), precuneus and lingual gyrus, etc. were observed. In Group B, deactivation in brainstem, bilateral thalamus, putamen, ACC, postterior cingulate cortex, hippocampus and cerebellum, etc., and activation in bilateral MCC, precuneus, left OFC, etc. were observed (p < 0.05, Family-wise error corrected).

CONCLUSIONS & INFERENCES

Different acupoints have similar clinical efficacy but relatively different cerebral responses. The influence on the sensory transduction regions (brainstem and thalamus) and visceral modulation regions might be the common mechanism of different acupoints treating for FD, and the modulation on some emotion/cognition-related areas (e.g., prefrontal cortex) is the potential difference between the different acupoints.

Characterization of Quinone Outside Inhibitor Fungicide Resistance in Cercospora sojina and Development of Diagnostic Tools for its Identification

Frogeye leaf spot of soybean, caused by the fungus Cercospora sojina, reduces soybean yields in most of the top-producing countries around the world. Control strategies for frogeye leaf spot can rely heavily on quinone outside inhibitor (QoI) fungicides. In 2010, QoI fungicide-resistant C. sojina isolates were identified in Tennessee for the first time. As the target of QoI fungicides, the cytochrome b gene present in fungal mitochondria has played a key role in the development of resistance to this fungicide class. The cytochrome b genes from three QoI-sensitive and three QoI-resistant C. sojina isolates were cloned and sequenced. The complete coding sequence of the cytochrome b gene was identified and found to encode 396 amino acids. The QoI-resistant C. sojina isolates contained the G143A mutation in the cytochrome b gene, a guanidine to cytosine transversion at the second position in codon 143 that causes an amino acid substitution of alanine for glycine. C. sojina-specific polymerase chain reaction primer sets and TaqMan probes were developed to efficiently discriminate QoI-resistant and -sensitive isolates. The molecular basis of QoI fungicide resistance in field isolates of C. sojina was identified as the G143A mutation, and specific molecular approaches were developed to discriminate and to track QoI-resistant and -sensitive isolates of C. sojina.

Regulation of mTOR Pathway in Exercise-induced Cardiac Hypertrophy

This study was designed to examine whether the mTOR signaling pathway would respond to long-term different intensity exercises and to observe the impact of exercise upon possible cardiac damage. Male Sprague Dawley rats were randomly divided into control group, moderate-intensity exercise group and high-intensity exercise group, and each exercise group had 4 observation time points (1-24 h). Exercise training lasted 8 weeks with a 2-day break for each week. Serum cTnI was measured by ELSIA and myocardium histology was assessed by HE and HBFP. The expressions of Akt, mTOR, p70(S6K) and their phosphorylated forms were determined by western-blot. Both exercises were effective at inducing cardiac hypertrophy, wherein magnitude increased with exercise intensity. The significantly high level of serum cTnI in the high-intensity group was accompanied by obvious myocellular abnormalities and ischemia in the myocardium. Significant activation of Akt, mTOR and p70(S6K) were observed in the moderate exercise group but not in the high-intensity exercise group. Results indicate that long-term high-intensity exercise training would induce cardiac hypertrophy accompanied by damage to the heart, entailing a risk of pathological changes. There might be a pivotal regulatory role of the mTOR signaling pathway on cardiac hypertrophy after long-term moderate exercise, but not after high-intensity exercise.

Effect of heavy-ion on frequency selectivity of semiconducting polymer/electrolyte heterojunction

Long-term bidirectional frequency selectivity has been achieved in MEH-PPV/PEO–Nd³⁺cells, which suggests spike-rate-dependent plasticity learning protocol. It depends on pulse shape due to variation of ionic type.

A recombined fusion protein SP5.2/tTF induce thrombosis in tumor blood vessel

Tumor vascular targeting is one of the most promising strategies in tumor therapy. Here we used E.coli to express a recombinant SP5.2/tTF fusion protein, which, as a tumor vascular targeting agent, consists of SP5.2 (a peptide selectively binding and targeting VEGFR-1 on tumor endothelial cells) and truncated tissue factor (tTF)and aimed to explore its anti-tumor activities.The SP5.2/tTF expression construct was synthesized by polymerase chain reaction (PCR) and recombined into plasmid pET22b(+). The fusion gene was verified by restriction mapping and sequencing. SP5.2/tTF was expressed in E. coli and then purified on a nickel-affinity chromatography column. The purified product was detected by SDS-PAGE. The pro-coagulant activity and binding of SP5.2/tTF to human umbilical vein endothelial cells (HUVECs) were monitored by FX activation analysis and fluorescent scanning confocal microscopy, respectively. The effect of SP5.2/tTF on tumor growth was analyzed in BALB/c mice bearing sarcoma 180 (S180) tumor. The tissue localization of SP5.2/tTF and its effect on tumor vessel thrombosis were observed by in vivo fluorescence imaging and histological studies, respectively. The fusion gene was successfully cloned into pET22b(+). SP5.2/tTF was abundantly expressed in bacterial cells and efficiently purified by nickel-affinity chromatography. Functional studies showed that the protein retained both the coagulation activity of tTF and the binding capacity of SP5.2 to HUVECs. In tumor xenograft studies, SP5.2/tTF selectively targeted the tumor, induced thrombosis, and led to retardation and even regression of tumor growth (growth inhibition ratio = 70%, P< 0.05). The recombinant fusion protein SP5.2/tTF inhibited tumor growth by selectively inducing thrombosis in tumor blood vessels.

Human genetics of diabetic retinopathy

There is evidence demonstrating that genetic factors contribute to the risk of diabetic retinopathy (DR). Genetics variants, structural variants (copy number variation, CNV) and epigenetic changes play important roles in the development of DR. Genetic linkage and association studies have uncovered a number of genetic loci and common genetic variants susceptibility to DR. CNV and interactions of gene by environment have also been detected by association analysis. Apart from nucleus genome, mitochondrial DNA plays critical roles in regulation of development of DR. Epigenetic studies have indicated epigenetic changes in chromatin affecting gene transcription in response to environmental stimuli, which provided a large body of evidence of regulating development of diabetes mellitus. Identification of genetic variants and epigenetic changes contributed to risk or protection of DR will benefit uncovering the complex mechanism underlying DR. This review focused on the current knowledge of the genetic and epigenetic basis of DR.

The influence of nutritional history on the functional response of Geocoris pallidipennis to its prey, Myzus persicae

Insect artificial diets are the foundation for mass production of insect predators. Whether there is an influence of long-term rearing with artificial diet on the control ability of predators should be considered. Here, we focused on the effect of nutritional history on the functional response of Geocoris pallidipennis to Myzus persicae. The influence of nutritional history (artificial diet versus natural prey, M. persicae) on the functional response of third to fifth instar nymphs and female G. pallidipennis was examined in the laboratory. The results showed that the functional response curve of both the nymphs and the adult female of G. pallidipennis to M. persicae reflected similar trends on both nutritional histories and confirmed the type II response. Adult female G. pallidipennis reared on either M. persicae or artificial diet produced a significantly better performance than the juvenile stages tested. We estimated that adult female G. pallidipennis can consume 141.6 (artificial diet) or 131.6 (M. persicae) aphids per day, respectively. This indicated that G. pallidipennis reared on both artificial diet and M. persicae displayed high rates of predation.