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This article reports that in Duchenne muscular dystrophy the earliest detectable abnormality in the muscle cell is breakdown of the plasma membrane. There is eventual loss of the muscle fibres with replacement by fat and connective tissue. Phospholipids are important components of cell membranes and have been the subject of numerous biochemical studies in both muscle and erythrocytes in muscular dystrophy. Because of the potential significance of an abnormality of lipids in relation to membrane structure and function, a careful study of lipids, especially phospholipids, was undertaken in normal and dystrophic muscle.

Pulse nanosecond fluorescence anisotropy decay has been used to study the mobility of tryptophan residues within fungal lipase from Humicola lanuginosa. The decay of emission anisotropy of protein in native, inhibited and mutated form has been investigated in buffered water and 50% v/v glycerol solutions. The rotational motions of the lipase were analyzed in terms of two different kinetic models. It was found that the fluorescence emission anisotropy decay can best be desribed with two rotational correlation times: 0.63 and 5.45 ns in water and 0.98 and 10.70 ns and in 50% v/v glycerol solution. Using the same experimental conditions the decay of inhibited and mutated H. lanuginosa lipase showed a similar biexponential character. These results are interpreted in terms of local or segmental motion arising from a mass of about 1083 daltons which corresponds to the ‘lid’-helix fragment of the enzyme. [ABSTRACT FROM AUTHOR]

Tartrate-resistant acid phosphatase (TRACP) and carbonic anhydrase II (CA II) are key enzymes responsible for osteoclastic bone resorption. In this study, we proposed that estrogen loss in postmenopausal osteoporosis may enhance gene expression of TRACP and CA II, and subsequently increase osteoclastic bone resorption. We have, therefore, used the ovariectomized rat model of postmenopausal bone loss to investigate changes at the gene transcriptional level in osteoclastic bone-resorbing enzymes in ovariectomized (OVX) rats, sham ovariectomized (S-OVX) rats, and estrogen-treated ovariectomized (E-OVX) rats. We have demonstrated for the first time that ovariectomy in rats enhances gene expression of TRACP, and CA II. The mRNA levels in OVX were approximately three- and four-fold higher, respectively, than those in S-OVX. Enhancement was observed 1 week after ovariectomy and transcripts remain high during the experimental period of 8 weeks. Administration of 17 beta-estradiol to OVX (E-OVX) reduced gene expression of these osteoclastic bone-resorbing enzymes 18 hours after injection. It appeared that the suppression of the osteoclastic bone-resorbing enzymes by 17 beta-estradiol was most effective during the first 1-2 weeks but the degree of suppression was reduced at 8 weeks after ovariectomy. In conclusion, our results suggest that estrogen prevents bone loss by reducing the mRNA levels of osteoclastic bone-resorbing enzymes in bone tissue. [ABSTRACT FROM AUTHOR]

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Nowadays, scientists from all over the world are focused on environmental issues connected with the greenhouse gases. The carbon dioxide is one of those gases. Therefore, researches are carried out to limit the emission or utilization the already ones. The aim of laboratory research was to find additives and admixtures resistant to CO2 presence and at the same time, able to modify rheological parameters of fresh cement slurry, as it is desirable during cementing of the wellbore. Moreover, research included the effect of newly synthesized polymers on the cement parameters. Laboratory research included filtration of the cement slurry, rheological parameters – Yield point, mechanical properties of hardened cement slurry obtained from hydraulic press and photographs of changes in mineralogical structure of cement from the electron microscope. The research was divided into two parts. The first one was based on the cement mixtures with commonly used superplastifier (SPL). In the second one, the SPL was replaced with newly synthesized polymer.

While drilling through clay rocks using water-based mud, number of challenges need to be faced in view of hydration and swelling of this type of rock. Those phenomena consist in the fact, that clay mineral grows in volume due to water contact. In order to limit hydration phenomenon, for clay rocks drilling are used drilling muds with addition of chemical agents called hydration inhibitors. The article describes studies, which resulted in development of new formula of drilling mud with addition of a new short-chained amino polymer developed in Drilling, Oil and Gas Faculty AGH-UST Krakow. For the developed mud, tests of technological parameters were conducted according to API RP 13B-1 as well as specialist examinations: linear swelling of Miocene shale and clay rock disintegration. Studies also consists of syntheses of polyampholyte and short-chained cationic polymer. Based on performed studies, it was found that studied mud is characterized by good and easy to regulate technological parameters as well as effective inhibition of hydration, swelling and disintegration of clay rocks.