Development of Dermestes tessellatocollis Motschulsky under different constant temperatures and its implication in forensic entomology.

Dermestidae generally appears on dry corpses and carcasses, especially if mummified or skeletonized. They are forensically important insect species for estimating longer postmortem intervals (PMI). As they develop, Dermestidae larvae undergo multiple larval ecdyses; however, a lack of guidelines for determining the larval instar limits their forensic application. Herein, we explored how temperature impacts the development of Dermestes tessellatocollis Motschulsky, 1860 (Coleoptera: Dermestidae). At seven constant temperatures (16, 19, 22, 25, 28, 31, and 34 °C), the developmental time from egg to adult was 163.87 ± 9.19, 103.56 ± 3.02, 63.59 ± 2.88, 51.49 ± 2.74, 47.86 ± 3.01, 44.62 ± 4.65, and 41.80 ± 4.87 days respectively. Four morphological indexes, including head capsule width, pronotum width, mesonotum width, and body length, were taken in vivo at regular intervals to identify methods for larval instar determination in D. tessellatocollis. The acquired morphological data were used to simulate fitted curves and equations depicting the relationship between the four morphological indexes and instars. From the validation experiment, we could hardly determine a specific instar based on the morphological indexes. The combination of morphometric data (head capsule, pronotum, and mesonotum width) generated the classification accuracy at 100%, 87.5%, 85%, and 93% for the 1st, 2nd/3rd, 4th/5th, and 6th/7th instars, respectively. Nevertheless, the accuracy was unsatisfactory for application in forensic casework. This study provides fundamental development data for adopting D. tessellatocollis in minimum postmortem interval (PMImin) estimations; however, further studies are needed to improve the classification accuracy for the larval instar determination.

Effects of sublethal phoxim exposure and lower food intake on nutrient metabolism in the midguts of Bombyx mori.

Silkworm (Bombyx mori) is an economically important insect. However, the survival of silkworms has been significantly affected by the assault of chemical pesticides on mulberry trees through aerial application and water currents. Phoxim is a broad-spectrum organophosphorus insecticide widely used in China. Currently, very little is known about the non-neuronal effects of sublethal exposure to phoxim. The purpose of this study was to investigate the non-neuronal effects of sublethal phoxim exposure in the silkworm midgut, with a focus on nutrient metabolism. After phoxim treatment, lipase activity in the silkworm was shown to be up-regulated at 24 h before a decreasing trend was seen. Meanwhile, α-amylase activity showed the opposite trend. The expression levels of mitochondrial respiratory chain-related genes were all up-regulated at 24 h before falling continuously. To ensure that the effects of phoxim on nutrient metabolism were not simply a consequence of a decrease in mulberry consumption, the silkworms were treated with a reduced-food diet before the digestive enzyme activities and the transcription levels of mitochondrial respiratory chain-related genes were analyzed. Our results showed that the patterns in the reduced-diet and phoxim-exposed silkworm were markedly different, suggesting the alterations in the phoxim-exposed silkworm cannot readily be explained by nutrient deprivation.

Estimating the age of Lucilia illustris during the intrapuparial period using two approaches: Morphological changes and differential gene expression.

Lucilia illustris (Meigen, 1826) (Diptera: Calliphoridae) is a cosmopolitan species of fly that has forensic and medical significance. However, there is no relevant study regarding the determination of the age of this species during the intrapuparial period. In this study, we investigated the changes in both morphology and differential gene expression during intrapuparial development, with an aim to estimate the age of L. illustris during the intrapuparial stage. The overall intrapuparial morphological changes of L. illustris were divided into 12 substages. Structures such as the compound eyes, mouthparts, antennae, thorax, legs, wings, and abdomen, each capable of indicating age during the intrapuparial stage, were observed in detail, and the developmental progression of each of these structures was divided into six to eight stages. We recorded the time range over which each substage or structure appeared. The differential expression of the three genes 15_2, actin, and tbp previously identified for predicting the timing of intrapuparial development was measured during L. illustris metamorphosis. The expression of these genes was quantified by real-time PCR, and the results revealed that these genes can be used to estimate the age of L. illustris during the intrapuparial period, as they exhibit regular changes and temperature dependence. This study provides an important basis for estimating the minimum postmortem interval (PMImin) in forensic entomology according to changes in intrapuparial development and differential gene expression. Furthermore, combination of the two approaches can generate a more precise PMImin than either approach alone.

Mitochondrial division inhibitor 1 (Mdivi-1) offers neuroprotection through diminishing cell death and improving functional outcome in a mouse model of traumatic brain injury.

Mitochondria dysfunction, an enormous potential crisis, has attracted increasing attention. Disturbed regulation of mitochondrial dynamics, the balance of mitochondrial fusion and fission, has been implicated in neurodegenerative diseases, such as Parkinson׳s disease and cerebral ischemia/reperfusion. However the role of mitochondrial dynamics in traumatic brain injury (TBI) has not been illuminated. The aim of the present study was to investigate the role of Mdivi-1, a small molecule inhibitor of a key mitochondrial fission protein dynamin-related protein 1 (Drp1), in TBI-induced cell death and functional outcome deficits. Protein expression of Drp1 was first investigated. Outcome parameters consist of motor test, Morris water maze, brain edema and lesion volume. Cell death was detected by propidium iodide (PI) labeling, and mitochondrial morphology was assessed using transmission electron microscopy. In addition, the expression of apoptosis-related proteins cytochrome c (cyt-c) and caspase-3 was investigated. Our findings showed that up-regulation of Drp1 expression started at 1h post-TBI and peaked at 24 h, but inhibition of Drp1 by Mdivi-1 significantly alleviated TBI-induced behavioral deficits and brain edema, reduced morphological change of mitochondria, and decreased TBI-induced cell death together with lesion volume. Moreover, treatment with Mdivi-1 remarkably inhibited TBI-induced the release of cyt-c from mitochondria to cytoplasm, and activation of caspase-3 at 24 h after TBI. Taken together, these data imply that inhibition of Drp1 may help attenuate TBI-induced functional outcome and cell death through maintaining normal mitochondrial morphology and inhibiting activation of apoptosis.

Chronic hypoxia in pregnancy affected vascular tone of renal interlobar arteries in the offspring.

Hypoxia during pregnancy could affect development of fetuses as well as cardiovascular systems in the offspring. This study was the first to demonstrate the influence and related mechanisms of prenatal hypoxia (PH) on renal interlobar arteries (RIA) in the 5-month-old male rat offspring. Following chronic hypoxia during pregnancy, phenylephrine induced significantly higher pressor responses and greater vasoconstrictions in the offspring. Nitric oxide mediated vessel relaxation was altered in the RIA. Phenylephrine-stimulated free intracellular calcium was significantly higher in the RIA of the PH group. The activity and expression of L-type calcium channel (Cav1.2), not T-type calcium channel (Cav3.2), was up-regulated. The whole-cell currents of calcium channels and the currents of Cav1.2 were increased compared with the control. In addition, the whole-cell K(+) currents were decreased in the offspring exposed to prenatal hypoxia. Activity of large-conductance Ca(2+)-activated K(+) channels and the expression of MaxiKα was decreased in the PH group. The results provide new information regarding the influence of prenatal hypoxia on the development of the renal vascular system, and possible underlying cellular and ion channel mechanisms involved.

Prenatal exposure to hypoxia induced Beclin 1 signaling-mediated renal autophagy and altered renal development in rat fetuses.

AIMS: Hypoxia has adverse effects on renal development. This study was the first to test hypoxia-induced renal autophagy in rat fetuses. METHODS: Pregnant rats were exposed to hypoxia or normoxia during pregnancy and fetal kidneys were collected at gestation day 21. RESULTS: Fetal kidney weight and ratio of kidney-body weight were reduced. Histological analysis showed enlargement in Bowman space and wider space between interstitia in the kidneys of fetus exposed to hypoxia. Fetal renal B-cell lymphoma 2 (BCL-2) was decreased accompanied with higher 2'-deoxyuridine 5'-triphosphate nick end-labeling staining and unchanged soluble FAS in the hypoxia group. Hypoxia increased autophagic structures, including autophagosomes and autolysosomes, in fetal kidneys and increased renal APG5L. There was an increase in renal LC3-II, Beclin 1, p-S6, hypoxia inducible factor 1α (HIF-1a), and ratio of LC3-II-LC3-I and a decrease in P62, protein kinase B (AKT), and phosphorylated AKT in the hypoxia group. Both renal mammalian target of rapamycin (mTOR) and Beclin 1 signaling were upregulated. CONCLUSION: Hypoxia-affected fetal renal development was associated with renal apoptosis and Beclin 1 signaling-mediated autophagy.

High-salt diets during pregnancy affected fetal and offspring renal renin-angiotensin system.

Intrauterine environments are related to fetal renal development and postnatal health. Influence of salty diets during pregnancy on renal functions and renin-angiotensin system (RAS) was determined in the ovine fetuses and offspring. Pregnant ewes were fed high-salt diet (HSD) or normal-salt diet (NSD) for 2 months during middle-to-late gestation. Fetal renal functions, plasma hormones, and mRNA and protein expressions of the key elements of renal RAS were measured in the fetuses and offspring. Fetal renal excretion of sodium was increased while urine volume decreased in the HSD group. Fetal blood urea nitrogen was increased, while kidney weight:body weight ratio decreased in the HSD group. The altered ratio was also observed in the offspring aged 15 and 90 days. Maternal and fetal plasma antidiuretic hormone was elevated without changes in plasma renin activity and Ang I levels, while plasma Ang II was decreased. The key elements of local renal RAS, including angiotensinogen, angiotensin converting enzyme (ACE), ACE2, AT1, and AT2 receptor expression in both mRNA and protein, except renin, were altered following maternal high salt intake. The results suggest that high intake of salt during pregnancy affected fetal renal development associated with an altered expression of the renal key elements of RAS, some alterations of fetal origins remained after birth as possible risks in developing renal or cardiovascular diseases.

[Genetic polymorphism of two STR loci D2S1399 and D5S2500 in Eastern Chinese Han population].

OBJECTIVE: To obtain the genetic polymorphism data of two STR loci D2S1399 and D5S2500 in Eastern Chinese Han population. METHODS: Blood samples or buccal swabs of unrelated Han individuals living in eastern China were analyzed using PCR-nature polyacrylamide gel electrophoresis-sliver staining method. RESULTS: 11 alleles of D2S1399 and 9 alleles of D5S2500 were observed in the samples respectively, the observed heterozygosity (Ho) values, the discrimination power (DP) values and the power of exclusion (PE) values of D2S1399 and D5S2500 is 0.745 and 0.807, 0.958 and 0.917, 0.554 and 0.643, respectively. CONCLUSION: The result showed that D2S1399 and D5S2500 were highly informative loci and suitable for forensic application.