Ingestion of the anti‐bacterial agent,gemifloxacin mesylate,leads to increased gst activity and peroxidation products in hemolymph of Galleria mellonella l. (lepidoptera: pyralidae)

Gemifloxacin mesylate (GEM) is a synthetic, fourth‐generation fluoroquinolone antibacterial antibiotic that has a broad spectrum of activity against bacteria. GEM inhibits DNA synthesis by inhibiting DNA gyrase and topoisomerase IV activities. Recent research into insect nutrition and mass‐rearing programs, in which antibiotics are incorporated into the culture media to maintain diet quality, raised a question of whether clinical antibiotics influence the health or biological performance of the insects that ingest these compounds. Because some antibiotics are pro‐oxidant compounds, we addressed the question with experiments designed to assess the effects of GEM (mesylate salt) on oxidative stress indicators, using Galleria mellonella larvae. The insects were reared from first‐instar larvae to adulthood on artificial diets amended with GEM at 0.001, 0.01, 0.1, or 1.0%. Feeding on the 1% diets led to significantly increased hemolymph contents of the lipid peroxidation product, malondialdehyde and protein oxidation products, protein carbonyl. All GEM concentrations led to increased hemolymph glutathione S‐transferase activity. We inferred that although it was not directly lethal to G. mellonella larvae, dietary exposure to GEM exerts measurable oxidative damage, possibly on insects generally. Long‐term, multigenerational effects remain unknown.     

Effects of Bacillus thuringiensis kurstaki on Malpighian tubule cells of Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) larvae

In this study effects of Bacillus thuringiensis kurstaki (Btk) on Malpighian tubule cells of Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) larvae was investigated by electron microscopy. 3 mg/l Btk was given with food. After Btk administration, the Malpighian tubule cells were investigated and compared with a control group. 3 and 6 hrs after Btk administration swelling in Malpighian tubule cells was observed. Swelling of mitochondria and separation of their cristae was seen after 12 hrs. After 24 hrs dissolution of the basal cytoplasm, swelling and vacuolization of all mitochondria, partial dissolution of the nucleoplasm, and swelling and separation ofmicrovilli was documented. A membrane-body in the nucleus was seen after 48 hrs. The nucleoplasm was completely dissolved after 72 hrs and after 96 hrs large vacuoles appeared in the cytoplasm and shortening of microvilli was observed.     

Enhanced kinetics of genetically engineered Burkholderia cepacia: the role of vgb in the hypoxic metabolism of 2-CBA

Application of Vitreoscilla hemoglobin (VHb) technology to 2-CBA degradation by Burkholderia cepacia strain DNT under hypoxic conditions was studied in continuous culture chemostats. Dechlorination abilities of both recombinant (VHb gene (vgb) containing) and untransformed cells were investigated at various dilution rates to ensure complete degradation of 2-CBA. As the dilution rate increased from 0.025 to 0.25 h(-1), the ratios of chloride release to degraded 2-CBA concentration decreased from 0.95 to 0.72 and from 0.89 to 0.39 for recombinant and untransformed cells, respectively. A nonstoichiometric relationship between chloride release and 2-CBA degradation was more pronounced for untransformed cells. Recombinant cell densities were 0.1-0.2. g L(-1) greater than untransformed cell densities for a range of dilution rates. As the dilution rate increased, the oxygen uptake rate (OUR) and the substrate utilization rate (SUR) decreased for both strains. The OUR/SUR ratio increased as the dilution rate increased for both strains but was much higher for the recombinant strain compared to untransformed cells. The specific 2-CBA degradation rate of recombinant cells was greater than that of untransformed cells (1.17 vs. 0.46 mg CBA (mg) day(-1), and half-saturation constants for recombinant cells were lower than those of untransformed cells (0.18 and 0.32 mg CBA L(-1), respectively). The pseudo-first-order degradation constants, k(1CBA) and k(1ACE), were higher for recombinant cells (6.5 L (mg cells)(-1) day(-1) and 95.6 L (mg cells)(-1) day(-1), respectively) than those of untransformed cells (1.44 L (mg cells)(-1) day(-1) and 73.7 L (mg cells)(-1) day(-1), respectively).     

Examination of metal mobilization from a gunshot by scanning acoustic microscopy,scanning electron microscopy,energy-dispersive X-ray spectroscopy,and inductively coupled plasma optical emission spectroscopy: a case report

Background

Projectile foreign bodies are known to cause chronic heavy metal toxicity due to the release of metal into the bloodstream. However, the local effect around the metallic object has not been investigated and the main goal of our study is to examine the influence of the object in close proximity of the object.

Case presentation

A 36-year-old Caucasian woman with one metallic pellet close to her sciatic nerve due to a previous shotgun injury at the gluteal area presented with a diagnosis of recurrent lumbar disk herniation at L4–5 level. A physical examination confirmed chronic neuropathy and she underwent a two-stage surgery. The surgery included removal of the foreign body, followed by discectomy and fusion at the involved level. During the removal of the metallic foreign body, a tissue sample around the pellet and another tissue sample from a remote area were obtained. The samples were analyzed by scanning acoustic microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Lead, chromium, copper, cadmium, iron, manganese, selenium, and zinc elements in tissue, blood, and serum specimens were detected by inductively coupled plasma optical emission spectroscopy.

Conclusions

An acoustic impedance map of the tissue closer to the metallic body showed higher values indicating further accumulation of elements. Energy-dispersive X-ray spectroscopy results confirmed scanning acoustic microscopy results by measuring a higher concentration of elements closer to the metallic body. Scanning electron microscopy images showed that original structure was not disturbed far away; however, deformation of the structure existed in the tissue closer to the foreign body. Element analysis showed that element levels within blood and serum were more or less within acceptable ranges; on the other hand, element levels within the tissues showed pronounced differences indicating primarily lead intoxication in the proximity of the metallic body. We can state that residues of metallic foreign bodies of gunshot injuries cause chronic metal infiltration to the surrounding tissue and induce significant damage to nearby neural elements; this is supported by the results of scanning acoustic microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and inductively coupled plasma optical emission spectroscopy.

     

Unveiling the polarity of actin filaments by cryo-electron tomography

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A novel method to measure regional muscle blood flow continuously using NIRS kinetics information

Background

This article introduces a novel method to continuously monitor regional muscle blood flow by using Near Infrared Spectroscopy (NIRS). We demonstrate the feasibility of the new method in two ways: (1) by applying this new method of determining blood flow to experimental NIRS data during exercise and ischemia; and, (2) by simulating muscle oxygenation and blood flow values using these newly developed equations during recovery from exercise and ischemia.

Methods

Deoxy (Hb) and oxyhemoglobin (HbO₂), located in the blood ofthe skeletal muscle, carry two internal relationships between blood flow and oxygen consumption. One is a mass transfer principle and the other describes a relationship between oxygen consumption and Hb kinetics in a two-compartment model. To monitor blood flow continuously, we transfer these two relationships into two equations and calculate the blood flow with the differential information of HbO₂ and Hb. In addition, these equations are used to simulate the relationship between blood flow and reoxygenation kinetics after cuff ischemia and a light exercise. Nine healthy subjects volunteered for the cuff ischemia, light arm exercise and arm exercise with cuff ischemia for the experimental study.

Results

Analysis of experimental data of both cuff ischemia and light exercise using the new equations show greater blood flow (four to six times more than resting values) during recovery, agreeing with previous findings. Further, the simulation and experimental studies of cuff ischemia and light exercise agree with each other.

Conclusion

We demonstrate the accuracy of this new method by showing that the blood flow obtained from the method agrees with previous data as well as with simulated data. We conclude that this novel continuous blood flow monitoring method can provide blood flow information non-invasively with NIRS.

     

THE INFLUENCE OF DIETARY α‐SOLANINE ON THE WAXMOTH Galleria mellonella L

Plant allelochemicals are nonnutritional chemicals that interfere with the biology of herbivores. We posed the hypothesis that ingestion of a glycoalkaloid allelochemical, α‐solanine, impairs biological parameters of greater wax moths Galleria mellonella. To test this idea, we reared wax moths on artificial diets with 0.015, 0.15, or 1.5 mg/100 g diet of α‐solanine. Addition of α‐solanine to the diet affected survival of seventh‐instar larvae, pupae, and adults; and female fecundity and fertility. The diet containing the highest α‐solanine concentration led to decreased survivorship, fecundity, and fertility. The diets supplemented with α‐solanine led to increased malondialdehyde and protein carbonyl contents in midgut and fat body and the effect was dose‐dependent. Dietary α‐solanine led to increased midgut glutathione S‐transferase activity and to decreased fat body glutathione S‐transferase activitiy. We infer from these findings that α‐solanine influences life history parameters and antioxidative enzyme activities in the midgut and fat body of G. mellonella.     

Arsenic Concentrations in the Surface,Well, and Drinking Waters of the Hisarcik,Turkey, Area

Arsenic is one of the most important water pollutants because of its carcinogenicity. The association between arsenical poisoning and the development of internal malignancies and skin cancer is well known. The U.S. Environmental Protection Agency (USEPA) sets maximum contaminant level goals at zero for carcinogens. In this study are presented groundwater arsenic concentrations in the area of naturally rich boron sources of Turkey. Water samples were collected from the Hisarcik, Turkey, area, which has a large boron mine. An inductively coupled plasma/mass spectrometry method was used to analyze arsenic concentrations in water samples. The arsenic levels in water ranged from no detectable amounts to 3.00 mg As/L (mean: 0.46 ± 0.07SD). This mean As level exceeds by a factor of 10 the USEPA's current Maximum Contaminant Level of 0.05 mgAs/L. Some possible health problems associated with consumption of arsenic-contaminated water are discussed and public health interventions proposed.