Requirement of Zn to demonstrate HCO3-stimulated ATPase activity of rat small intestinal brush border.

The existence of a membrane-bound HCO3-stimulated ATPase in intestinal mucosa is controversial. A crude brush border fraction of rat small intestinal homogenates contained HCO3-ATPase activity which was inhibited by preincubation with 3 mM EDTA. Alkaline phosphatase activity of this preparation was also inhibited in a parallel, time-dependent fashion by preincubation with EDTA. When 5 mM ZnSO4 accompanied 3 mM EDTA in the preincubation mix, preservation of both enzyme activities occurred, demonstrating a requirement of Zn for the activity of both these phosphatases. These studies support the earlier contention that HCO3-ATPase and alkaline phosphatase activities may be different properties of the same enzyme, and raise the possibility that the ATPase could play a role in intestinal ion transport. The failure to identify a membrane-bound HCO3-ATPase by other workers could be due to the exposure of EDTA which occurred in their tissue preparation

The Changing Role Of Technology at the Elementary School Level

The world we live in has become heavily influenced by technology. Elementary education is no exception. In today’s classrooms, there are a multitude of technological programs and resources used by teachers and students. This capstone examines the changing role of technology at the elementary school level. Through the use of literature review, online research, and interviews with multiple elementary teachers in Santa Cruz County, results findings reveal the effects on teaching and learning at the elementary school level. There are many positive outcomes as well as some of concern for this transition. This new technology comes with a learning curve that will require schools to provide more resources for teachers, including training and technological assistance. With the right tools and trainings, technology can be a very powerful tool when used in moderation in the classroom

GFR increases before renal mass or ODC activity increase in rats fed high protein diets

GFR increases before renal mass or ODC activity increase in rats fed high protein diets. Consumption of a high protein diet causes renal hypertrophy and increased glomerular filtration rate (GFR). To determine the relationship between increases in GFR, renal ornithine decarboxylase activity (ODC), arginase activity, and renal growth, dietary protein intake was increased from 8.5% to 40% in 50 male Sprague-Dawley rats (HP). Forty-one rats remained on 8.5% protein as time controls (LP). Eight to 17 animals were killed daily for measurement of kidney weight (kidney wt), ODC and arginase activities, total kidney protein and DNA content. GFR increased within the first 24 hours after the increase in dietary protein and reached a maximum within 48hrs. ODC increased from 9.7 ± 0.8 U/g to a peak of 170 ± 35 U/g at 48 hours, decreasing to a stable value of 28.6 ± 8.0 U/g at 72 hours and 25.4 ± 5.1 U/g at 168 hours, a value significantly greater than that at time zero. Arginase activity did not change. Kidney wt as percent body weight (body wt) increased after the initial increase in both GFR and in ODC activity. The peak in ODC activity corresponded with the maximum increase in GFR and preceded the increase in renal mass. After GFR stabilized, ODC activity decreased to a plateau and renal growth relative to body wt ceased. The increase in kidney weight was accompanied by a parallel increase in total kidney protein. Kidney protein/ kidney DNA ratio increased significantly by 96 hours, indicating that renal hypertrophy had occurred. The sequence of these events suggests that increasing GFR may trigger the rise in ODC activity

Production of functional proteins: balance of shear stress and gravity

A method for the production of functional proteins including hormones by renal cells in a three dimensional culturing process responsive to shear stress uses a rotating wall vessel. Natural mixture of renal cells expresses the enzyme 1-.alpha.-hydroxylase which can be used to generate the active form of vitamin D: 1,25-diOH vitamin D.sub.3. The fibroblast cultures and co-culture of renal cortical cells express the gene for erythropoietin and secrete erythropoietin into the culture supernatant. Other shear stress response genes are also modulated by shear stress, such as toxin receptors megalin and cubulin (gp280). Also provided is a method of treating an in-need individual with the functional proteins produced in a three dimensional co-culture process responsive to shear stress using a rotating wall vessel

The effect of frequent hemodialysis on nutrition and body composition: frequent Hemodialysis Network Trial.

We investigated the effects of frequency of hemodialysis on nutritional status by analyzing the data in the Frequent Hemodialysis Network Trial. We compared changes in albumin, body weight, and composition among 245 patients randomized to six or three times per week in-center hemodialysis (Daily Trial) and 87 patients randomized to six times per week nocturnal or three times per week conventional hemodialysis, performed largely at home (Nocturnal Trial). In the Daily Trial, there were no significant differences between groups in changes in serum albumin or the equilibrated protein catabolic rate by 12 months. There was a significant relative decrease in predialysis body weight of 1.5 ± 0.2 kg in the six times per week group at 1 month, but this significantly rebounded by 1.3 ± 0.5 kg over the remaining 11 months. Extracellular water (ECW) decreased in the six times per week compared with the three per week hemodialysis group. There were no significant between-group differences in phase angle, intracellular water, or body cell mass (BCM). In the Nocturnal Trial, there were no significant between-group differences in any study parameter. Any gain in 'dry' body weight corresponded to increased adiposity rather than muscle mass but was not statistically significant. Thus, frequent in-center hemodialysis reduced ECW but did not increase serum albumin or BCM while frequent nocturnal hemodialysis yielded no net effect on parameters of nutritional status or body composition

Inflammation and premature aging in advanced chronic kidney disease

Systemic inflammation in end-stage renal disease (ESRD) is an established risk factor for mortality and a catalyst for other complications which are related to a premature aging phenotype, including muscle wasting, vascular calcification and other forms of premature vascular disease, depression, osteoporosis and frailty. Uremic inflammation is also mechanistically related to mechanisms involved in the aging process, such as telomere shortening, mitochondrial dysfunction, and altered nutrient sensing, which can have direct effect on cellular and tissue function. In addition to uremia-specific causes such as abnormalities in the phosphate- Klotho axis, there are remarkable similarities between the pathophysiology of uremic inflammation and so-called "inflammaging" in the general population. Potentially relevant, but still somewhat unexplored in this respect are abnormal or misplaced protein structures as well as abnormalities in tissue homeostasis, which evoke danger signals through damage associated molecular patters (DAMPS) as well as the senescence associated secretory phenotype (SASP). Systemic inflammation, in combination with the loss of kidney function, can impair the resilience of the body to external and internal stressors by reduced functional and structural tissue reserve, and by impairing normal organ crosstalk, thus providing an explanation for the greatly increased risk of homeostatic breakdown in this population. In this review, the relation between uremic inflammation and a premature aging phenotype, as well as potential causes and consequences are discussed