Mn-SOD 47 CC genotype in combination with high tea consumption may prevent complications in Tunisian type-2 diabetes.

Reactive oxygen species metabolizing enzymes may play an important role in the prevention of type-2 diabetes (T2D) complications. We analyzed the association between Cu/Zn-SOD +35 A/C, Mn-SOD T47C, and CAT -21 A/T gene polymorphisms and complications, in combination with tea consumption in Tunisian T2D. A sample of 366 T2D subjects was enrolled in this study. All participants were asked about tea consumption and frequency. Anthropometric, clinical, and routine biochemical characteristics were obtained from subjects' updated medical records. Malondialdehyde, as an early marker of lipid peroxidation, was measured in plasma samples. Urinary polyphenol derivatives (UPDs), as a marker of polyphenols intake, were assessed by the Folin-Ciocalteu assay. SODs and CAT genotypes were determined by conventional restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) methods. From all subjects, the results showed that in high tea consumers (>3 cups/day), the frequency of the Mn-SOD 47 CC genotype was significantly higher in T2D without complications compared with T2D with complications (P = 0.03; OR = 0.284; 95%CI = 0.086-0.939). However, no significant associations were observed with Cu/Zn-SOD +35 A/C or CAT -21 A/T genes polymorphisms. Additionally, the evaluation of UPDs showed that individuals carrying the Mn-SOD 47 CC genotype and consuming more than three cups of tea per day present significantly higher UPDs (P = 0.038). In conclusion, the Mn-SOD 47 C variant in combination with high tea consumption may provide protection against complications in T2D.

Experimental evidence of twin fast metastable H(2(2)S) atoms from dissociation of cold H2 induced by electrons.

We report the direct detection of two metastable H(2^{2}S) atoms coming from the dissociation of a single cold H(2) molecule, in coincidence measurements. The molecular dissociation was induced by electron impact in order to avoid limitations by the selection rules governing radiative transitions. Two detectors, placed close to the collision center, measure the neutral metastable H(2(2)S) through a localized quenching process, which mixes the H(2^{2}S) state with the H(2^{2}P), leading to a Lyman-α detection. Our data show the accomplishment of a coincidence measurement which proves for the first time the existence of the H(2(2)S)-H(2(2)S) dissociation channel.

Low density lipoproteins extracted from hen egg yolk by an easy method: cryoprotective effect on frozen-thawed bull semen.

Hen egg yolk is widely used as a cryoprotective agent in semen freezing extenders in order to protect the spermatozoa against cold shock. The protective action of yolk is largely presumed to be due to low density lipoproteins (LDL). In recent years, arguments concerning the presence of cryoprotective antagonists in egg yolk, have reinforced interest in the use of only the LDL extracted from egg yolk in the extenders. However, current methods of LDL purification do not support the use of LDL in commercial extenders because they offer a poor recovery rate. Consequently, we have developed an easy method to extract LDL from egg yolk. Several concentrations of purified LDL (between 2.5 and 20%, w/v) were tested in freezing extenders for bull semen, and compared with commercial extenders. Our extraction method reached 97% purity and about 67% yield, and is easily reproducible on an industrial scale. Analysis of sperm motility showed that the motility and characteristics of spermatozoa movement were improved with LDL in the extender, as compared to a commercial extender containing egg yolk. The optimum LDL concentration in the extender was 8%. In conclusion, we propose that an extender containing LDL extracted from egg yolk could be used as cryoprotective media with a better efficiency than present commercial extenders.

Effects of glutamine, proline, histidine and betaine on post-thaw motility of stallion spermatozoa.

The supplementation of the freezing diluent with 3 amino acids (glutamine, proline and histidine) and 1 amino acid-related compound (betaine) in preserving stallion spermatozoa diluted in INRA82 extender containing 2.5% (v/v) glycerol and 2% (v/v) egg yolk (control extender) during freezing and thawing was studied at 0, 40, 80, 120 and 160 mM in 20 split ejaculates (10 stallions x 2 ejaculates; Experiment 1). Glutamine and proline were studied at 0, 10, 20, 30, 40, 50, 60, 70 and 80 mM in 20 split ejaculates (10 stallions x 2 ejaculates; Experiment 2). In each experiment, spermatozoa were evaluated after thawing by computer automated sperm analyzer. The percentage of motile spermatozoa (faster than 30 microns/sec) was assessed. In addition, the velocity of the average path (VAP), the straight line velocity (VSL), the curvilinear velocity (VCL) and the amplitude of the lateral head displacement (ALH) were also measured. In Experiment 1, only glutamine (40 mM) significantly improved sperm motility (56.0% +/- 3.0 vs 49.7% +/- 1.6; P < 0.05) compared with the control extender, while velocities were unaffected at concentrations of 40 to 120 mM. However, at 160 mM, a significant decrease in motility and velocity was observed for all amino acids. In Experiment 2, motility in glutamine (range 41.1% +/- 3.8%; 42.4% +/- 3.6) and proline (43.0% +/- 3.7; 45.6% +/- 3.8) extenders compared with the control (34.7% +/- 1.6) was improved significantly (P < 0.05). Sperm velocity was improved at concentrations higher than 40 mM glutamine and 50 mM proline.

A procedure for Poitou jackass sperm cryopreservation.

We have tried to establish sperm banking for the endangered Poitou donkeys. No successful cryopreservation technique had been described for spermatozoa of this species; our preliminary work indicated that a particular medium and procedure may be effective for cryopreservation of Poitou jackass spermatozoa as evaluated by sperm motility, membrane integrity and pregnancy rate after AI with frozen-thawed semen. We found that glutamine at 80 mM and 10% (v/v) quail egg yolk in a basal medium containing 4% (v/v) glycerol (T2-94 medium) improved the post-thaw total and progressive motility and velocity assessed with the automated analyzer ATS-M. The T2-94 medium also preserved the sperm nuclear, acrosom, and plasma membrane integrity as assessed with the acridine orange method, fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA) lectin procedure, and hypo-osmotic swelling test, respectively. Semen frozen-thawed in T2-94 medium as used to artificially inseminate. 13 Poitou jennies from the beginning of estrus to ovulation during 4 cycles at a rate of one AI per day. Heigh pregnancies and 3 foals were obtained, but only when the glycerol was removed from sperm before AI. We conclude that the cryopreservation of Poitou jackass semen for sperm banking may succeed by using the T2-94 medium and removing the glycerol post-thaw, but before AI.

Quail egg yolk: a novel cryoprotectant for the freeze preservation of Poitou jackass sperm.

For many years, attempts have been made to establish a sperm bank for the Poitou jackass population which is threatened with extinction. Unfortunately, no cryopreservation technique has ever been described for spermatozoa of this species. In an attempt to find a suitable technique, we studied the relative effectiveness of chicken egg yolk and quail egg yolk in preserving the motility and characteristics of movement of Poitou jackass spermatozoa during the freezing-thawing process. Semen was diluted to 60 x 10(6) sperm/ml in a preservation medium containing 4% (v/v) glycerol with 0, 2, 5, 10, 15, or 20% (v/v) of chicken or quail egg yolk. The chemical composition of these two eggs was compared. Effects were assessed using an automated analyzer which measured curvilinear velocity (VCL), straight line velocity (VSL), and the velocity of the average path. Linearity was defined as VSL/VCL x 100. The amplitude of the lateral head displacement was also measured. It was found that after the freeze-thaw process, quail egg yolk improved the percentages of motile and progressively undulating spermatozoa and the movement characteristics compared with chicken egg yolk. The optimal concentration of quail egg yolk was 10%. The general composition of the two types of egg yolk were similar, but quail egg yolk contained significantly more phosphatidylcholine, less phosphatidylethanolamine, and a smaller ratio of polyunsaturated to saturated fatty acids than chicken egg yolk. The improvement of motility for frozen-thawed Poitou jackass spermatozoa using frozen-thawed quail egg yolk compared to chicken egg yolk may be due to the differences in composition of the two yolks.

Improvement of motility of post-thaw Poitou jackass sperm using glutamine.

The relative effectiveness of L-glutamine in preserving motility and movement characteristics of Poitou jackass spermatozoa diluted at 60 x 10(6) sperm/ml in INRA 82 medium modified by 4 % (v/v) glycerol and 2 % (v/v) quail's egg yolk during the cooling and freezing-thawing process was studied. After cooling to 4 degrees C, glutamine at 80, 120 or 240 mM did not improve the percentages of motile and progressively undulating spermatozoa or the movement characteristics (VCL = curvilinear velocity, VSL = straight line velocity, VAP = velocity of the average path, LIN = VSL/VCL x 100, ALH = amplitude of the lateral head displacement, BCF = beat cross frequency) assessed by the automated analyzer ATSM. However, after the FT process, 80 mM glutamine significantly improved motility, the percentage of progressively undulating spermatozoa and all the movement characteristics analyzed. The presence of glutamine at 80 mM in a glycerol-FT medium thus improves the motility of Poitou jackass spermatozoa during the freezing-thawing process. The presence of glutamine at 80 mM was not sufficient to offset the need to use glycerol in the freezing-thawing medium. This could indicate that glutamine has a mechanism of cryoprotection for Poitou jackass spermatozoa that is independant of glycerol.