Increased fibrovascular invasion of subcutaneous polyvinyl alcohol sponges in SPARC-null mice

The expression of SPARC (secreted protein acidic and rich in cysteine/osteonectin/BM-40) is elevated in endothelial cells participating in angiogenesis in vitro and in vivo. SPARC acts on endothelial cells to elicit changes in cell shape and to inhibit cell cycle progression. In addition, SPARC binds to and diminishes the mitotic activity of vascular endothelial growth factor. To determine the effect(s) of SPARC on angiogenic responses in vivo, we implanted polyvinyl alcohol sponges subcutaneously into wild-type and SPARC-null mice. On days 12 and 20 following implantation, SPARC-null mice showed increased cellular invasion of the sponges in comparison to wild-type mice. Areas of the sponge with the highest cell density exhibited the highest numbers of vascular profiles in both wild-type and SPARC-null animals. The endothelial component of the vessels was substantiated by immunoreactivity with three different markers specific for endothelial cells. Although sponges from SPARC-null relative to wild-type mice were populated by significantly more cells and blood vessels, an increase in the ratio of vascular to nonvascular cells was not apparent. No differences in the percentage of proliferating cells within the sponge were detected between wild-type and SPARC-null sections. However, elevated levels of vascular endothelial growth factor were associated with sponges from SPARC-null versus wild-type mice. An increase in vascular endothelial growth factor production was also observed in SPARC-null primary dermal fibroblasts relative to those of wild-type cells. In conclusion, we have shown that the fibrovascular invasion of polyvinyl alcohol sponges is enhanced in mice lacking SPARC, and we propose that increased levels of vascular endothelial growth factor account, at least in part, for this response.     

Development of a parent-report computer-adaptive test to assess physical functioning in children with cerebral palsy I: lower-extremity and mobility skills

The objective of this project was to develop computer-adaptive tests (CATs) using parent reports of physical function in children and adolescents with cerebral palsy (CP). The specific aims of this study were to (1) examine the psychometric properties of an item bank of lower-extremity and mobility skills for children with CP; (2) evaluate a CAT using this item bank; (3) examine the concurrent validity of the CAT with the Pediatric Outcomes Data Collection Instrument (PODCI) and the Functional Assessment Questionnaire (FAQ); and (4) establish the discriminant validity of simulated CATs with Gross Motor Function Classification System (GMFCS) levels and CP type (diplegia, hemiplegia, or quadriplegia). Parents ( n =190) of children and adolescents with spastic diplegic (48%), hemiplegic (22%), or quadriplegic (30%) CP consisting of 108 males and 82 females with a mean age of 10 years 7 months (SD 4y 1mo, range 2–21y) and in GMFCS levels I to V participated in item pool calibration and completed the PODCI and FAQ. Confirmatory factor analyses supported a unidimensional model for the 45 basic lower-extremity and mobility items. Simulated CATs of 5, 10, and 15 items demonstrated excellent accuracy (intraclass correlation coefficients [ICCs] >0.91) with the full item bank and had high correlations with PODCI transfers and mobility (ICC = 0.86) and FAQ scores (ICC = 0.77). All CATs discriminated among GMFCS levels and CP type. The lower-extremity and mobility skills item bank and simulated CATs demonstrated excellent performance over a wide span of ages and severity levels.     

THERMAL PERTURBATION SPECTROPHOTOMETRY OF LULIBERIN AND MODEL HIS-TRP PEPTIDES

Thermal perturbation (TP) spectra of luliberin were measured at pH 5–8, and compared with the model chromophores N-Ac-Tyr-NH₂, N-Ac-Trp-NH₂, t-Boc-His-Trp-NH₂, H-His-Trp-OH, Ac-His-Trp-OH, tryptophan and cyclo- [His-Trp] (all l -isomers). Between pH 5 and neutrality, the major TP extremum of the Trp³ residue of luliberin increases by about 50%. A similar effect is seen for luliberin acetylated on Tyr⁵. The effect with luliberin is attributed to the protonation of the His² residue. One proposed explanation is that the protonated imidazole orients water around the nearby indole in a different way than does unprotonated imidazole. The Tyr⁵ residue of luliberin behaves like N-Ac-Tyr-NH₂, and is considered to be well exposed to solvent. The TP spectra of N-Ac-Trp-NH₂, t-Boc-His-Trp-NH₂, Ac-His-Trp-OH, and cyclo-[His-Trp] are pH-independent from pH 5 to 8. The TP spectrum of H-His-Trp-NH₂ has a bell-shaped pH dependence, rising from normal at pH 3.5 to above normal at pH 6, and returning to normal at pH 8. Luliberin and model peptides show that fluorescence and TP spectra of His-Trp sequences can respond differently to pH.     

INACTIVATION OF CEREBELLAR NITRIC OXIDE SYNTHASE BY ETHANOL IN VITRO

The N-methyl-D-aspartate receptor/nitric oxide synthase (NOS)/guanylatecyclase pathway, which plays a crucial role in synaptic plasticityin the brain, is modulated by ethanol. We studied the effectof ethanol in vitro on NOS in rat cerebellum and showed thatethanol (25–200 mM) inactivated NOS in a dose-dependentmanner. This inactivation was prevented by the biopterin cofactortetrahydrobiopterin (BH⁴) as well as by L-arginine, a NOS substrate,but not by NADPH. These results suggest that ethanol reducesNOS activity by modulating the conformation of the enzyme andthereby its stability, probably by interacting with the bindingsites of BH⁴ and/or of L-arginine. Our data also suggest thatinactivation of NOS may contribute to the decrease in the cGMPlevel, and thus may play a role in the pharmacological actionsof ethanol in vivo.     

Dental care habits and knowledge of oral health in insulin-dependent diabetics

Abstract – The aim of this study was to investigate dental care habits and knowledge of oral health in age- and sex-matched adult long and short duration insulin-dependent diabetics and non-diabetics. Ninety-four long and 86 short duration diabetics and 86 non-diabetics, aged 20–70 years, participated in the study. All subjects answered a questionnaire with 38 questions about dental visits, attitudes to and knowledge of dental diseases, toothcleaning, dietary and smoking habits, and oral sensations. Among the diabetics there was a rather large group that did not visit a dentist annually. The diabetics also required more emergency dental care and were not as willing as the non-diabetics to spend time and money on their teeth. The compliance with dietary advice was poor among the diabetics. Oral discomfort such as prickling and burning sensations, metallic and bad taste was rare in both diabetics and non-diabetics. In the diabetics, however, a feeling of mouth dryness was common.