Description of characteristics of humic substances from different waste materials

Humic acids (HAs) extracted from different organic wastes have been characterised by chemical methods. The chemical properties of HAs showed differences depending on the source from which they were obtained. The C content in HAs from organic wastes (41.1-63.2%) fluctuated around the C value in soil HA with the exception of composted bark and tobacco dust. Compared with soil HA, the N contents of HAs from sewage sludge and brewery sludge were found much higher than the others. E4:E6 ratios for HAs in organic wastes were generally greater than that for soil HA, which indicated a low degree of condensation and humification. The carboxyl and phenolic-OH group contents ranged 0.51-2.23 and 11.1-20.7 meq g(-1), respectively. High values of carboxyl and phenolic-OH contents indicated that these materials were still within early stages of humification.     

Histological and biochemical effects of cigarette smoke on lungs

In this study, rats were made to inhale cigarette smoke in a specifically prepared container for different periods. The lung tissue samples of the subjects were examined by light microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Malonaldehyde, one of the free oxygen radicals was determined in lungs and plasma. The catalase activity level of erythrocyte and arginase levels were determined. Three groups were formed. The rats in the Ist and IInd groups were made to inhale cigarette smoke for 30 and 60 minutes a day for a total period of 3 months. Control group, the rats in the IIIrd group (controls) were made to inhale clean air during the same periods. An increase in the number of macrophages was observed in the pulmonary tissue of the exposed groups. Especially in the group that inhaled the smoke for long periods, the number of macrophages and the inclusion bodies contained in them increased. These differences could easily be observed in TEM studies. In the light microscopy and SEM observations, it arouse attention that the alveolar macrophages occurred as sets and their activation increased. Depending on the length of the exposure to cigarette smoke, an increase in the number of macrophages was observed. Statistically significant increases were determined in the malonaldehyde levels of pulmonary tissue and plasma when compared to the control group. Besides significant increases were found in the catalase activity levels of erythrocytes in the experimental groups.     

A safer and relatively shorter method for Southern blot hybridization analysis

The study presented here describes a Southern blot hybridization technique which is performed in a shorter time and safer than the classical one. In this study DNA was isolated from a small amount of blood sample and the probe for hybridization was prepared with (35)S by polymerase chain reaction.     

Post‐translational modifications of transthyretin affect the triiodonine‐binding potential

Transthyretin (TTR) is a visceral protein, which facilitates the transport of thyroid hormones in blood and cerebrospinal fluid. The homotetrameric structure of TTR enables the simultaneous binding of two thyroid hormones per molecule. Each TTR subunit provides a single cysteine residue (Cys₁₀), which is frequently affected by oxidative post‐translational modifications. As Cys₁₀ is part of the thyroid hormone‐binding channel within the TTR molecule, PTM of Cys₁₀ may influence the binding of thyroid hormones. Therefore, we analysed the effects of Cys₁₀ modification with sulphonic acid, cysteine, cysteinylglycine and glutathione on binding of triiodothyronine (T3) by molecular modelling. Furthermore, we determined the PTM pattern of TTR in serum of patients with thyroid disease by immunoprecipitation and mass spectrometry to evaluate this association in vivo. The in silico assays demonstrated that oxidative PTM of TTR resulted in substantial reorganization of the intramolecular interactions and also affected the binding of T3 in a chemotype‐ and site‐specific manner with S‐glutathionylation as the most potent modulator of T3 binding. These findings were supported by the in vivo results, which indicated thyroid function‐specific patterns of TTR with a substantial decrease in S‐sulphonated, S‐cysteinylglycinated and S‐glutathionylated TTR in hypothyroid patients. In conclusion, this study provides evidence that oxidative modifications of Cys₁₀ seem to affect binding of T3 to TTR probably because of the introduction of a sterical hindrance and induction of conformational changes. As oxidative modifications can be dynamically regulated, this may represent a sensitive mechanism to adjust thyroid hormone availability.     

Increase in Candida parapsilosis Fungemia in Critical Care Units: A 6-Years Study

Objectives

We aimed to asses possible clinically significant differences between C. parapsilosis and other candida species candidemia receiving care in the intensive care unit (ICU) setting.

Methods

The study included 118 adult patients diagnosed as candidemia after admission to the ICU of a university hospital between January 2004 and December 2009. Data about demographic characteristics, underlying diseases, and risk factors for ICU-related candidemia were collected.

Results

During the study period, 118 patients with candidemia were identified among 2,853 patients admitted into the ICU. Candidemia was seen in 41.4 cases per 1,000 ICU admissions. The overall incidence of candidemia in ICU patients during the study period was 2.09 per 1,000 hospital admissions. Of the isolates, 18.6% were C. albicans and 81.4% were C. non-albicans. The species most frequently isolated was C. parapsilosis (66.1%, 78/118). The distribution of other Candida spp. was as follows: 15 had C. tropicalis (12.7%) and 3 had C. glabrata (2.5%). By Statistical analysis, when patients with candidemia who had C. parapsilosis were compared with other Candida spp., the following factors were found to be significantly associated with C. parapsilosis fungemia; intravascular catheters (p = 0.008), malignity (p = 0.049) and age (p = 0.039). Relationship was found between C. tropicalis and hematologic malignancies (p = 0.001).

Conclusions

When infections with a high mortality such as candidemia is suspected in critically ill patients, it is important to know local risk factors and epidemiological distributions of causative agents in selection of empirical and effective antifungal treatment.     

Ultrastructural Changes in the Kidney of Rats with Acute Exposure to Cadmium and Effects of Exogenous Metallothionein

Ultrastructural changes in the kidneys of rats after acute cadmium exposure and the effects of exogenous metallothionein (MT) were studied by transmission electron microscopy. Thirty-six adult Wistar rats were divided into three groups. Cadmium chloride (CdCl₂) (3.5 mg/kg/day) was injected subcutaneously in the first group. In the second group, 30 μmol/kg MT was administered in addition to CdCl₂. Control rats received 0.5 ml subcutaneous saline solution. Four rats from each group were killed on days 1, 3, 5, and 7 after administration of the compounds. Kidney tissues were taken and fixed in 2.5% glutaraldehyde solution for electron microscopic observations. Tissue damage in kidney increased as time passed since the administration of CdCl₂ in the first group. Degeneration in the proximal and distal tubules was observed. Increased apoptosis was seen in the proximal tubules epithelium, especially on day 7. Peritubular capillaries became dilated, there was degeneration of the endothelial cells, and the amount of intertubular collagen fibers was increased. On day 1, irregular microvilli in the proximal tubules, deepening of the basal striations, and myelin figures; on day 3, multiple vesicular mitochondria and regions of edema around tubules; on days 5 and 7, increased apoptotic cell in the proximal tubules and widened rough endoplasmic reticulum of the endothelial cells of glomerular capillaries were observed. We observed that the structural alterations that increased depending on the day of Cd administration decreased after exogenous MT administration, the dilation of the peritubular capillaries persisted, and there were degenerated proximal tubules. It was established that cadmium chloride was toxic for kidney cortex and caused structural damage. Exogenous MT partly prevents CdCl₂-induced damage.     

Purification,biochemical characterization and gene sequencing of a thermostable raw starch digesting α-amylase from Geobacillus thermoleovorans subsp. stromboliensis subsp. nov.

This study reports the purification and biochemical characterization of a raw starch-digesting α-amylase from Geobacillus thermoleovorans subsp. stromboliensis subsp. nov. (strain Pizzo^T). The molecular weight was estimated to be 58 kDa by SDS–PAGE. The enzyme was highly active over a wide range of pH from 4.0–10.0. The optimum temperature of the enzyme was 70°C. It showed extreme thermostability in the presence of Ca²⁺, retaining 50% of its initial activity after 90 h at 70°C. The enzyme efficiently hydrolyzed 20% (w/v) of raw starches, concentration normally used in starch industries. The α-amylase showed an high stability in presence of many organic solvents. In particular the residual activity was of 73% in presence of 15% (v/v) ethyl alcohol, which corresponds to ethanol yield in yeast fermentation process. By analyzing its complete amyA gene sequence (1,542 bp), the enzyme was proposed to be a new α-amylase.