Antihyperlipidemic potential of dietary supplementation with carnosine in high-fat diet-fed rats.

OBJECTIVE: The aim of this study was to investigate the hypolipidemic effects of carnosine and a commercial carnosine supplement on lipid status, liver and kidney function, and inflammation associated with dyslipidemia in rats with high-fat diet-induced hyperlipidemia. MATERIALS AND METHODS: The study was conducted on adult male Wistar rats, divided into control and experimental groups. Animals were kept in standard laboratory conditions and according to groups were treated with saline, carnosine, carnosine dietary supplement, simvastatin, and their combinations. All substances were prepared fresh every day and used by oral gavage. RESULTS: Treatment with a carnosine-based supplement significantly improved total and LDL cholesterol levels in serum, especially in the combination with simvastatin as a conventional drug in dyslipidemia treatment. The effect of carnosine on the metabolism of triglycerides was not as evident as in the case of cholesterol. Nevertheless, the values of the atherogenic index showed that the combinations of carnosine and carnosine supplement with simvastatin were the most effective in lowering this comprehensive lipid index. Dietary carnosine supplementation resulted also in anti-inflammatory effects, as demonstrated by immunohistochemical analyses. Besides, the good safety profile of carnosine in terms of its effect on liver and kidney functions was also confirmed. CONCLUSIONS: The use of carnosine supplements in preventing and/or treatment of metabolic disorders requires further investigations into the mechanisms of action and potential interactions with conventional therapy.

Impact of winter savory extract (Satureja montana L.) on biochemical parameters in serum and oxidative status of liver with application of the principal component analysis in extraction solvent selection.

OBJECTIVE: Satureja montana L. is traditionally used as spice and for treatment various diseases. Many studies have shown antioxidative effect of Satureja species. Our thorough study in an animal model was performed through measurement of biochemical parameters in the serum, histology analysis and determination of oxidative status of the liver, coupled with investigation of extraction solvent selection using principal component analysis (PCA). MATERIALS AND METHODS: Winter savory dry extract (500 mg/kg) dispersion and saline solution were given to Wistar rats for 7 days after exposure to oxidative stress using toxic doses of paracetamol (600 mg/kg). Rats were sacrificed, after which a complete autopsy was performed, the blood obtained was used to determine biochemical parameters, and the liver was sliced for histological analysis and determination of oxidative stress enzymes. RESULTS: Indicators of hepatic and kidney functions, as well as the concentration of oxidative stress enzymes, were statistically significantly lower in animals treated with Satureja montana L. extract compared to the paracetamol group alone before the toxic dose of paracetamol. Liver enzymes were unaltered by pre-treatment with the extract, but the level of lipid peroxidase was decreased, and the level of catalase, glutathione reductase and superoxide dismutase increased proving in vivo antioxidant effect. In addition, the number of inflammatory cells is decreased coupled with activity of CYP2E1 enzymes proving hepatoprotective effect. CONCLUSIONS: Satureja montana L. extract in our research has shown hepatoprotective, anti-inflammatory and antioxidative effect. PCA analyses indicated that extraction mediums have a great impact on the antioxidative effect.

DNA replication forks pause at silent origins near the HML locus in budding yeast.

Chromosomal replicators in budding yeast contain an autonomously replicating sequence (ARS) that functions in a plasmid, but certain ARSs are silent as replication origins in their natural chromosomal context. In chromosome III, the HML ARS cluster (ARS302-ARS303-ARS320) and ARS301 flank the transcriptionally silent mating-type locus HML, and all of these ARSs are silent as replication origins. ARS301 and ARS302 function in transcriptional silencing mediated by the origin recognition complex (ORC) and a heterochromatin structure, while the functions of ARS303 and ARS320 are not known. In this work, we discovered replication fork pause sites at the HML ARS cluster and ARS301 by analyzing DNA replication intermediates from the chromosome via two-dimensional gel electrophoresis. The replication fork pause at the HML ARS cluster was independent of cis- and trans-acting mutations that abrogate transcriptional silencing at HML. Deletion of the HML ARS cluster led to loss of the pause site. Insertion of a single, heterologous ARS (ARS305) in place of the HML ARS cluster reconstituted the pause site, as did multiple copies of DNA elements (A and B1) that bind ORC. The orc2-1 mutation, known to alter replication timing at origins, did not detectably affect the pause but activated the silent origin at the HML ARS cluster in a minority of cells. Delaying the time of fork arrival at HML led to the elimination of the pause sites at the HML ARS cluster and at the copy of ARS305 inserted in place of the cluster. Loss of the pause sites was accompanied by activation of the silent origins in the majority of cells. Thus, replication fork movement near HML pauses at a silent origin which is competent for replication initiation but kept silent through Orc2p, a component of the replication initiator. Possible functions for replication fork pause sites in checkpoints, S-phase regulation, mating-type switching, and transcriptionally silent heterochromatin are discussed.

Identification and characterization of glucocorticoid receptors in B16 mouse melanoma cells.

OBJECTIVE: To gain better insight into the role of glucocorticoids as modulators of cell growth, as well as to investigate the presence and characteristics of glucocorticoid receptors (GR) in mouse melanoma cells. METHODS: In two different B16 mouse melanoma cell clones (B16/F10 and B16/C3) the role of synthetic glucocorticoids (triamcinolone acetonide, TA) as cell growth modulators was investigated. RESULTS: The inhibitory effect of TA on B16/F10 cell growth after 8 days in culture was observed. The same hormonal treatment applied on B16/C3 melanoma cells also provoked changes in the cell growth. Dot blot analysis, using monoclonal antirodent glucocorticoid receptor antibodies showed the presence of receptor protein in both cell clones. The analysis of glucocorticoid receptors in B16/F10 and B16/C3 cell cytosol by Scatchard assay and ion-exchange chromatography on DEAE-Sephadex A-50 minicolumn indicated that the changes in melanoma cell growth may be mediated by glucocorticoid receptors and may relieve changes in the GR itself. CONCLUSIONS: It was found that B16/C3 melanoma cells exhibited different growth pattern under TA treatment when compared to the results obtained with B16/F10 cells. Such differences may be mediated by glucocorticoid receptors.

Activation of silent replication origins at autonomously replicating sequence elements near the HML locus in budding yeast.

In the budding yeast, Saccharomyces cerevisiae, replicators can function outside the chromosome as autonomously replicating sequence (ARS) elements; however, within chromosome III, certain ARSs near the transcriptionally silent HML locus show no replication origin activity. Two of these ARSs comprise the transcriptional silencers E (ARS301) and I (ARS302). Another, ARS303, resides between HML and the CHA1 gene, and its function is not known. Here we further localized and characterized ARS303 and in the process discovered a new ARS, ARS320. Both ARS303 and ARS320 are competent as chromosomal replication origins since origin activity was seen when they were inserted at a different position in chromosome III. However, at their native locations, where the two ARSs are in a cluster with ARS302, the I silencer, no replication origin activity was detected regardless of yeast mating type, special growth conditions that induce the transcriptionally repressed CHA1 gene, trans-acting mutations that abrogate transcriptional silencing at HML (sir3, orc5), or cis-acting mutations that delete the E and I silencers containing ARS elements. These results suggest that, for the HML ARS cluster (ARS303, ARS320, and ARS302), inactivity of origins is independent of local transcriptional silencing, even though origins and silencers share key cis- and trans-acting components. Surprisingly, deletion of active replication origins located 25 kb (ORI305) and 59 kb (ORI306) away led to detection of replication origin function at the HML ARS cluster, as well as at ARS301, the E silencer. Thus, replication origin silencing at HML ARSs is mediated by active replication origins residing at long distances from HML in the chromosome. The distal active origins are known to fire early in S phase, and we propose that their inactivation delays replication fork arrival at HML, providing additional time for HML ARSs to fire as origins.

Molecular analysis of the rolling-circle replicating plasmid pA1 of Lactobacillus plantarum A112.

Lactobacillus plantarum A112 has four different plasmids. Plus-origin-specific probes were used to determine that the smallest, cryptic plasmid, pA1 (2,820 bp), showed homology to the pE194 plasmid family. This subclass of plasmids uses the rolling-circle mode of replication. Subsequent analysis of plasmid pA1 demonstrated that it generates single-stranded DNA intermediates, and sequence analysis revealed that it contains three putative open reading frames (ORFs): ORF1, ORF2, and ORF3, which could encode proteins designated RepA (47 amino acids [aa]) and RepB (196 aa) and a protein of 103 aa, respectively. Two of these proteins, RepA (5.6 kDa) and RepB (26 kDa), were identified in in vitro transcription translation assays. The RepA protein contains a characteristic alpha-helix-turn-alpha-helix motif typical of DNA-binding proteins that act as DNA-binding repressors. The RepB protein shows a significant similarity with replication initiation proteins of the pE194 family of plasmids that use the rolling-circle mode of replication. Plasmid pA1 is able to replicate in Escherichia coli and Lactobacillus lactis subsp. lactis as well as in other L. plantarum strains.

Analysis of exopolysaccharide production by Lactobacillus casei CG11, isolated from cheese.

Exopolysaccharide-producing Lactobacillus casei CG11 was isolated from soft, white, homemade cheese. In basal minimal medium, it produces a neutral heteropolysaccharide consisting predominantly of glucose (about 75%) and rhamnose (about 15%). Plasmid curing experiments revealed that exopolysaccharide production by strain CG11 is linked to a plasmid approximately 30 kb in size.

Thermography in the detection and follow up of chondromalacia patellae.

Although diagnostic criteria for chondromalacia patellae exist, the disease is often accompanied by physical signs which are limited or non-diagnostic. Thermographic examination was performed in 157 patients with clinical diagnosis of chondromalacia patellae in 86 patients after surgical treatment for chondromalacia, and in 308 controls. Thermography can help the clinicians in establishing the diagnosis of chondromalacia patellae, but by itself is not sufficiently specific. The specificity of thermography was dependent on age, ranging from 90% for the 15-24 year age group to 65% for the 45-54 year age group. Sensitivity of the method was 68%. Thermography can disclose other knee disorders which imitate chondromalacia patellae.

Microbiologic transformation of progesterone by Curvularia clavata Jain.

Progesterone was transformed microbiologically by the fungal strain Curvularia clavata Jain. Progesterone (I) was added as substrate when the microorganism reached its exponential growth phase. Three substances were isolated after the fermentation: a non-steroidal substance, radicinin (II), which has been established to be a metabolic product of the fungus and acts as a phytotoxin, and two steroidal substances which resulted from fungal enzymatic action on the progesterone molecule. The structure of each microbial metabolite was elucidated by 1H-nuclear magnetic resonance, mass spectrometry, and infrared and UV analyses, and the yields were determined by high-pressure liquid chromatography. The progesterone metabolites were characterized as 7 alpha,14 alpha-dihydroxypregn-4-ene-3,20-dione (III) and 11 beta, 14 alpha-dihydroxypregn-4-ene-3,20-dione (IV). Evidence for the structure of these steroidal products came from derivatives resulting from acetylation and dehydration.

[The importance of thermography in the diagnosis of the cervico-brachial syndrome]. / Znacenje termografije u dijagnostici cervikobrahijalnog sindroma.

In 349 patients with clinical diagnosis of cervicobrachial syndrome thermographic examinations were made during 1987 and 1988. An hyperthermic zone over the cervical region or/and an hypothermic zone over the upper extremity were found in 143 of 203 women (70%) and 115 of 146 men (79%). Ther are great differences in frequencies of thermographic changes between employed and retired patients. In younger age thermographic changes are much lower. In 53% of male patients aged 30-39 there were no thermographic changes, but the same result was found in only 9% of male patients aged 50-59. Clinical diagnosis is not sufficiently relevant in assessment of thermographic changes in patients with cervicobrachial syndrome.