Development of microsatellite markers for the Japanese endemic conifer Thuja standishii and transfer to other East Asian species.

OBJECTIVE: Design polymorphic microsatellite loci that will be useful for studies of the genetic diversity, gene-flow and reproduction in the Japanese endemic conifer Thuja standishii and test the transferability of these loci to the two other East Asian species, T. sutchuenensis and T. koraiensis. RESULTS: Fifteen loci were developed which displayed 3 to 21 alleles per locus (average = 9.2) among 97 samples from three populations of T. standishii. Observed heterozygosity for all samples varied between 0.33 and 0.75 (average = 0.54) while expected heterozygosity values were higher with an average over the 15 loci of 0.62 (0.37-0.91). Low multi-locus probability of identity values (< 0.00002) indicate that these markers will be effective for identifying individuals derived from clonal reproduction. All 15 loci amplified in 13 samples of T. sutchuenensis, the sister species of T. standishii, with 1 to 11 alleles per locus (average = 4.33) while 13 loci amplified in four samples of the more distantly related T. koraiensis with 1 to 5 alleles per locus (average = 2.15).

Unmyelinated fibers in human spinal ventral roots: C4 to S2.

STUDY DESIGN: Histological examination of human spinal ventral roots. OBJECTIVES: To determine the proportion of unmyelinated fibers in human ventral roots from the 4th cervical (C4) to 2nd sacral (S2) segment, and to evaluate differences in the proportions of unmyelinated fibers between the cervical, thoracic, lumbar and sacral segments, and between autonomic and other segments. SETTING: University Teaching Hospital, Busan, Korea. METHODS: Eight embalmed adult human cadavers (six males and two females; mean age 56.3 years) were collected. The ventral root samples were obtained by transverse cuts of the ventral roots within 1 cm proximal to the medial portion of the dorsal root ganglion from the C4 to S2 segment. The number of unmyelinated and myelinated fibers was counted in four fields, and the mean number of unmyelinated fibers was calculated. The percentage of unmyelinated fibers was calculated from the ratio of unmyelinated fibers to total fibers (myelinated fibers+unmyelinated fibers). RESULTS: The mean percentages of unmyelinated axons in cervical (C4-C8), thoracic (T1-T12), lumbar (L1-L5) and sacral (S1-S2) ventral roots were 16.3, 21.4, 17.8 and 20.7%, respectively. The percentage of unmyelinated fibers in thoracic ventral roots was higher than that for other segments (P<0.001). There was no significant difference in proportions of unmyelinated fibers between the sympathetic segments (T11-L2), parasympathetic segments (S2) and the other segments (C4-T10 and L3-S1) (P=0.1784). CONCLUSIONS: Approximately 20% of human spinal ventral root fibers were unmyelinated. The proportion of unmyelinated fibers was highest in the thoracic segments.

Quantitation of niflumic acid in human plasma by high-performance liquid chromatography with ultraviolet absorbance detection and its application to a bioequivalence study of talniflumate tablets.

A rapid and simple HPLC method with UV detection (288 nm) was developed and validated for quantitation of niflumic acid in human plasma, the active metabolite of talniflumate. After precipitation with 100% methanol containing the internal standard, indomethacin, the analysis of the niflumic acid level in the plasma samples was carried out using a reverse phase C18 CAPCELL PAK (5 microm, 4.6 mm x 250 mm) column. The chromatographic separation was accomplished with an isocratic mobile phase consisting of a mixture of 0.1M sodium acetate in water and acetonitrile (37:63, v/v), adjusted to pH 6.4. This HPLC method was validated by examining its precision and accuracy for inter- and intra-day runs in a linear concentration range of 0.02-5.00 microg/mL. Stability of niflumic acid in plasma was excellent, with no evidence of degradation during sample processing (autosampler) and 30 days storage in a freezer. This validated method was successfully applied to the bioequivalence study of talniflunate in healthy volunteers.

Spontaneous N incorporation onto a Si(100) surface.

Initial nitridation of the Si(100) surface is investigated using photoemission, ion-scattering and ab initio calculations. After dissociation of NO or NH3, nitrogen atoms are found to spontaneously form a stable, highly coordinated N[triple bond]Si(3) species even at room temperature. The majority of the N species is incorporated into the subsurface Si layers occupying an interstitial site, whose atomic structure and unique bonding mechanism is clarified through ab initio calculations. This unusual adsorption behavior elucidates the atomistic mechanism of initial silicon nitride formation on the surface and has important implication on the N-rich layer formation at the SiO(x)N(y)/Si interface.

Metabolism in the artificially reared rat pup: effect of an atypical rat milk substitute.

A substitute for rat milk [Messer et al., 1969 (1)] has been evaluated as a nutrient source to artificially feed rat pups from 4 days after birth. The rat milk substitute has a normal fat concentration, suboptimal protein concentration and a high carbohydrate concentration when compared to natural rat milk. Rat pups artificially reared on the mild substitute by intermittent infusion via miniaturized intragastric cannulae have: 1) atypical ketone body metabolism: lower than normal concentration and turnover of D-(--)-3-hydroxybutyrate in blood and less than normal amounts of D-(--)-3-hydroxybutyrate used for respiration, 2) atypical carbohydrate metabolism: higher than normal insulin and galactose concentrations in blood and a greater than normal amount of glucose used for respiration, and 3) atypical amino acid levels: the concentrations of several amino acids in blood were 60% or less than normal, and the concentration of taurine in plasma was negligible. We observed frequent head tremors, hyperreactivity to handling and about a 20% incidence of cataracts in rat pups reared on the milk substitute. We conclude this rat milk substitute is not suitable as a nutrient source for the developing rat pup.

Arginine requirements in immature dogs.

Labrador Retriever puppies (3 kg) were fed L-amino acid (L-AA) diets, containing the equivalent of 14% protein, to determine dietary argnine requirements for optimal growth and maintenance of normal intermediary metabolism. Growth and food consumption were depressed by decreasing the dietary arginine concentration. Urinary citrate and orotate increased with decreasing dietary arginine. Elevated blood orotate, urea and NH4+-N were detected in arginine deficient dogs. More than 0.56% arginine was required to support optimum growth and prevent abnormal loss of urinary metabolites. The effect of dietary nitrogen concentration (14, 21, or 28% L-AA) on arginine requirements was examined in immature Beagles. All arginine deficient dogs and dogs fed the 28% L-AA with arginine showed signs of emesis, excessive salivation and muscle tremors. Hyperammonemia and hyperglycemia were observed 2 hours after force feeding an L-AA diet devoid of arginine. Only hyperammonemia was observed in the Labrador Retrievers fed the same diet but incorporated into a 2% agar gel. Dietary nitrogen concentration or dietary arginine content dit not significantly influence glucose tolerance response to oral glucose loading. These data show that dietary arginine is required in the immature dog and that the requirement is influenced by dietary nitrogen concentration.