Tracing compartment exchange by NMR diffusometry: Water in lithium-exchanged low-silica X zeolites.

The two-region model for analyzing signal attenuation in pulsed field gradient (PFG) NMR diffusion studies with molecules in compartmented media implies that, on their trajectory, molecules get from one region (one type of compartment) into the other one with a constant (i.e. a time-invariant) probability. This pattern has proved to serve as a good approach for considering guest diffusion in beds of nanoporous host materials, with the two regions ("compartments") identified as the intra- and intercrystalline pore spaces. It is obvious, however, that the requirements of the application of the two-region model are not strictly fulfilled given the correlation between the covered diffusion path lengths in the intracrystalline pore space and the probability of molecular "escape" from the individual crystallites. On considering water diffusion in lithium-exchanged low-silica X zeolite, we are now assuming a different position since this type of material is known to offer "traps" in the trajectories of the water molecules. Now, on attributing the water molecules in the traps and outside of the traps to these two types of regions, we perfectly comply with the requirements of the two-region model. We do, moreover, benefit from the option of high-resolution measurements owing to the combination of magic angle spinning (MAS) with PFG NMR. Data analysis via the two-region model under inclusion of the influence of nuclear magnetic relaxation yields satisfactory agreement between experimental evidence and theoretical estimates. Limitations in accuracy are shown to result from the fact that mass transfer outside of the traps is too complicated for being adequately reflected by simple Fick's laws with but one diffusivity.

Pharmacokinetics of 125I-labeled insulin glargine (HOE 901) in healthy men: comparison with NPH insulin and the influence of different subcutaneous injection sites.

OBJECTIVE: To determine the subcutaneous absorption rates and the appearance in plasma of 3 formulations of the long-acting human insulin analog insulin glargine (HOE 901) differing only in zinc content (15, 30, and 80 microg/ml). RESEARCH DESIGN AND METHODS: We conducted 2 studies. Study 1 compared the subcutaneous abdominal injection of 0.15 U/kg of 125I-labeled insulin glargine[15], insulin glargine[80], NPH insulin, and placebo. In study 2, 0.2 U/kg of insulin glargine[30] was injected into the arm, leg, and abdominal regions. Both studies had a randomized crossover design; each enrolled 12 healthy men, aged 18-50 years. RESULTS: In study 1, the time in hours for 25% of the administered radioactivity to disappear after bolus subcutaneous injection (T75%) for NPH insulin indicated a significantly faster absorption rate compared with the 2 insulin glargine formulations (3.2 vs. 8.8 and 11.0 h, respectively P < 0.0001). Mean residual radioactivity with NPH insulin was also significantly lower at 24 h (21.9 vs. 43.8 and 52.2%, P < 0.0001). The calculated plasma exogenous insulin concentrations after NPH insulin were substantially higher than those with insulin glargine, reaching a peak within the first 6 h after administration before declining. Insulin glargine, however, did not exhibit a distinct peak. Weighted average plasma glucose concentration between 0 and 6 h was significantly lower after NPH compared with insulin glargine (P < 0.001). In study 2, there were no significant differences in the absorption characteristics of insulin glargine between the 3 injection sites (T75% = 11.9, 15.3, and 13.2 h for arm, leg, and abdomen, respectively) or in residual radioactivity at 24 h. CONCLUSIONS: Subcutaneous absorption of insulin glargine is delayed compared with NPH insulin. There is little or no difference in the absorption rate of insulin glargine between the main subcutaneous injection sites.

Molecular basis of feline beta-glucuronidase deficiency: an animal model of mucopolysaccharidosis VII.

A family of domestic cats was found that exhibited clinical and biochemical abnormalities consistent with mucopolysaccharidosis VII, an autosomal recessive lysosomal storage disorder caused by beta-glucuronidase deficiency. beta-Glucuronidase activity was undetectable in affected cat fibroblasts and restored by retroviral gene transfer of rat beta-glucuronidase cDNA. beta-Glucuronidase mRNA was normal in affected cat testis by Northern blot analysis. Normal feline beta-glucuronidase cDNA was cloned and characterized, and amplified from affected cat fibroblasts by reverse transcription coupled polymerase chain reaction. There was a G-to-A transition in the affected cat cDNA that predicted an E351K substitution, destroyed a BssSI site, and eliminated GUSB enzymatic activity in expression studies. Multiple species comparison and the crystal structure of human beta-glucuronidase indicated that E351 is a highly conserved residue most likely essential in maintenance of the enzyme's conformation. BssSI digestion of polymerase chain reaction products amplified from genomic DNA indicated that affected cats were homozygous and cats with half-normal beta-glucuronidase activity were heterozygous for the missense mutation. Carriers identified in this manner produced affected kittens in prospective breedings, and a feline MPS VII breeding colony has been established.

Literalism and hypnosis: hypnotic versus task-motivated subjects.

To extend previous literalism research with hypnotized and simulating subjects, we compared literalism rates of hypnotized, highly hypnotizable subjects (N = 12) with nonhypnotized, task-motivated subjects (N = 12) who were also highly hypnotizable. Six questions of the type used by Erickson (e.g., "Do you mind telling me your name?") constituted tests of literalism (scored if response is "Yes" or "No," either verbally or nonverbally). Whereas Erickson claimed that 97% of his "deep trance" subjects and 90% of his "medium trance" subjects exhibited literal responses, we found that 87.5% of hypnotized, high-hypnotizable subjects' responses were nonliteral. Hypnotized and task-motivated subjects did not differ in their literal responding to the individual questions or when their scores were summed across questions. No support was secured for Erickson's assertion that literalism is a cardinal feature of hypnosis.

Literalism as a marker of hypnotic "trance": disconfirming evidence.

The responses given by highly hypnotizable, hypnotic subjects and those of unhypnotizable subjects who simulated hypnosis to questions of the type, "Do you mind telling me your name?" and "Do you mind standing up?" were contrasted. The purpose was to examine Erickson's (1980) assertion that literalism (answering "yes" or "no" verbally or nonverbally without any cognitive elaboration) is a marker of hypnotic "trance." Simulators exhibited a greater rate of literalism than hypnotic "virtuosos" (i.e., extreme scorers on both group and individual hypnotizability measures). Hypnotized subjects and nonhypnotized subjects approached in the campus library responded comparably. Because less than a third of hypnotic virtuosos responded literally, our results strongly refuted Erickson's assertion that literalism is a cognitive feature of hypnosis.