KN Group Research Articles

UJI AKTIVITAS JUS BUAH JAMBU BIJI BERDAGING MERAH (Psidium guajava L.) TERHADAP PENINGKATAN TROMBOSIT PADA MENCIT (Mus musculus L.) YANG DIINDUKSI KLORAMFENIKOL

Thrombocytopenia is the most common hemostatic disorder acquired in dogs and can be a life-threatening. Guava fruit and leaves extract are believed to improve thrombocyte counts. The purpose of this study was to prove that administration of guava juice could improve thrombocyte count in mice that have thrombocytopenia after induced by chloramphenicol. We were used 24 mice as samples divided into 4 groups : KS group (given aquades for 12 days), KN group (induced by chloramphenicol for 7 days, then aquades on next 5 days), group P1 (induced by chloramphenicol for 7 days then guava juice 5 g/ml concentration on 5 next day); and group P2 (induced by chloramphenicol for 7 days then guava juice 10 g/ml concentration on the next 5 days). Thrombocyte count was measured three times, before treatment (day 0), after chloramphenicol induction (day 7), and after guava juice (day 12). Data of thrombocyte count was analyzed using one way Anova and Post Hoc LSD test. The results showed that the guava juice (Psidium guajava L.) concentration of 5 g/ml and 10 g/ml had significant effect (p <0,05) to increase platelet numbers in mice after induced by chlorampenicol dose 30mg/30grBW.

UJI AKTIVITAS JUS BUAH JAMBU BIJI BERDAGING MERAH (Psidium guajava L.) TERHADAP PENINGKATAN TROMBOSIT PADA MENCIT (Mus musculus L.) YANG DIINDUKSI KLORAMFENIKOL

Thrombocytopenia is the most common hemostatic disorder acquired in dogs and can be a life-threatening. Guava fruit and leaves extract are believed to improve thrombocyte counts. The purpose of this study was to prove that administration of guava juice could improve thrombocyte count in mice that have thrombocytopenia after induced by chloramphenicol. We were used 24 mice as samples divided into 4 groups : KS group (given aquades for 12 days), KN group (induced by chloramphenicol for 7 days, then aquades on next 5 days), group P1 (induced by chloramphenicol for 7 days then guava juice 5 g/ml concentration on 5 next day); and group P2 (induced by chloramphenicol for 7 days then guava juice 10 g/ml concentration on the next 5 days). Thrombocyte count was measured three times, before treatment (day 0), after chloramphenicol induction (day 7), and after guava juice (day 12). Data of thrombocyte count was analyzed using one way Anova and Post Hoc LSD test. The results showed that the guava juice (Psidium guajava L.) concentration of 5 g/ml and 10 g/ml had significant effect (p <0,05) to increase platelet numbers in mice after induced by chlorampenicol dose 30mg/30grBW.

Lactobacillus plantarum IS-10506 activates intestinal stem cells in a rodent model.

This study investigated the probiotic effect of Lactobacillus plantarum IS-10506 in activating and regenerating leucine-rich repeat-containing G-protein-coupled receptor (Lgr)5- and B lymphoma Moloney murine leukaemia virus insertion region (Bmi)1-expressing intestinal stem cells in rodents following Escherichia coli serotype 055:B5 lipopolysaccharide (LPS) exposure. Male Sprague-Dawley rats (n=64) were randomised into control (KN), LPS (KL), probiotic + LPS (KL-Pr), and sequential probiotic + LPS + probiotic (KPR-7L) groups. Microencapsulated L. plantarum IS-10506 (2.86×1010 cfu/day) was administered via a gastric tube once daily for up to 7 days, and LPS (250 ng/kg body weight) was administered via a gastric tube on the first day of the experiment to all but the KN group. On day 3, 4, 6, and 7, four rats per group were sacrificed, and Lgr5, Bmi1, extracellular signal-regulated kinase (ERK), and β-catenin expression in the ileum was assessed by immunohistochemistry. LPS treatment reduced Lgr5 (P≤0.05) and Bmi1 (P=0.000) levels in intestinal epithelial cells, whereas probiotic treatment increased levels of Lgr5 (KPR-7L, P=0.008) and Bmi1 (KL-Pr, P=0.008; and KPR-7L, P=0.000). Lgr5 expression was upregulated in the KL-Pr group on day 3, 4, 6, and 7 (P=0.056). Additionally, ERK levels were elevated in Bmi1- and Lgr5-expressing cells in rats treated with probiotics (KL-Pr and KPR-7L), whereas β-catenin levels were increased in Lgr5-expressing cells from KPR-7L rats and in Bmi1-expressing cells from KL-Pr and KPR-7L rats on day 3 and 4. These results demonstrated that the probiotic L. plantarum IS-10506 activated intestinal stem cells to counter inflammation and might be useful for maintaining intestinal health, especially when used as a prophylactic agent.

Impaction Force Influences Taper-Trunnion Stability in Total Hip Arthroplasty

BackgroundThis study investigated the influence of femoral head impaction force, number of head strikes, the energy sequence of head strikes, and head offset on the strength of the taper-trunnion junction. MethodsThirty titanium-alloy trunnions were mated with 36-mm zero-offset cobalt-chromium femoral heads of corresponding taper angle. A drop tower impacted the head with 2.5J or 8.25J, resulting in 6 kN or 14 kN impaction force, respectively, in a single strike or combinations of 6 kN + 14 kN or 14 kN + 14 kN. In addition, ten 36-mm heads with −5 and +5 offset were impacted with sequential 14 kN + 14 kN strikes. Heads were subsequently disassembled using a screw-driven mechanical testing frame, and peak distraction force was recorded. ResultsFemoral head pull-off force was 45% the strike force, and heads struck with a single 14 kN impact showed a pull-off force twice that of the 6 kN group. Two head strikes with the same force did not improve pull-off force for either 6 kN (P = .90) or 14 kN (P = .90). If the forces of the 2 impactions varied, but either impact measured 14 kN, a 51% higher pull-off force was found compared to impactions of either 6 kN or 6 kN + 6 kN. Femoral head offset did not significantly change the pull-off force among −5, 0, and +5 heads (P = .37). ConclusionFemoral head impaction force influenced femoral head trunnion-taper stability, whereas offset did not affect pull-off force. Multiple head strikes did not add additional stability, as long as a single strike achieved 14 kN force at the mallet-head impactor interface. Insufficient impaction force may lead to inadequate engagement of the trunnion-taper junction.

44 Inaccurate Hemoglobin S+C Estimates Prior to Emergent Red Blood Cell Exchange Procedures Lead to Overtransfusion

As a therapeutic treatment for sickle cell disease, red blood cell (RBC) exchange rapidly removes unwanted hemoglobin (Hgb) S and C and replaces it with donated RBC units containing mainly Hgb A. Determining how much blood to deliver to reach the targeted goal, however, requires laboratory testing for the current measure of abnormal hemoglobin. If results are unknown prior to the start of the procedure, especially in emergent situations, the level must be estimated. We investigated to what degree these estimates led to inappropriate overtransfusion or undertransfusion in our patient population. This was a retrospective, observational study from 2011 to 2016 of patients who had completed one or more RBC exchange procedures in the inpatient setting at a large academic medical center. The following information was obtained: history of disease, number of procedures received, emergent status of procedures, number of RBC units per procedure, goal Hgb S+C percentage, goal fraction of cells remaining (FCR), and Hgb S+C percentages measured pre- and postprocedure. Procedures that lacked any of the latter three pieces of information were not included in the analysis. Estimated preprocedural Hgb S+C percentage was calculated by dividing the Hgb S+C goal by the FCR. Overtransfusion and undertransfusion were determined by comparing the original FCR to an FCR calculated using the actual preprocedural and goal Hgb S+C percentages. During the study period, 378 RBC exchange procedures were assessed. Three primary groups of procedures were evaluated: emergent procedures with unknown preprocedural Hgb S+C percentage (E-U), nonemergent procedures with unknown preprocedural Hgb S+C percentage (NE-U), and procedures with known preprocedural Hgb S+C percentage (Kn). The percent difference between the estimated and actual preprocedural Hgb S+C levels was calculated for each procedure. The median difference (and range) for the E-U, NE-U, and Kn groups was 26.6% (–9.8%-270.4%), 1.6% (–33.5%-311.0%), and 1.3% (–19.5%-118.0%), respectively. The E-U group was significantly different from the other two groups (P < .0001), but the NE-U group was not different from the Kn group (P = .16). Undertransfusion occurred in 14% of procedures by a total of 38 RBC units, and overtransfusion in 39% of procedures by a total of 167 RBC units. Approximately 1/2 of the excess 167 units came from emergent procedures, despite comprising less than 20% of the total procedures. More than half of RBC exchange procedures (53%) resulted in the patient receiving an incorrect number of RBC units, mostly overtransfusion attributable to emergent procedures in which the lab results were still pending by the time the procedures began. These results suggest that a rapid turnaround time method should be available to measure abnormal hemoglobin levels prior to the start of RBC exchange.

On an isomorphism lying behind the class number formula

Let p be an odd prime such that the Greenberg conjecture holds for the maximal real cyclotomic subfield K1 of Q[ζp]. Let An = (C(Kn))p be the p-part of the class group of Kn, the n-th field in the cyclotomic tower, and let En, Cn be the global and cyclotomic units of Kn, respectively. We prove that under this premise, there is some n0 such that for all m ≥ n0, the class number formula (Em/Cm)p = |Am| hides in fact an isomorphism of Λ[Gal(K1/Q)]-modules.

Approche p-adique de la conjecture de Greenberg pour les corps totalement réels

Let k be a totally real number field ant let k$\infty$ be its cyclotomic Zp-extension for a prime p\textgreater{}2. We give (Theorem 3.2) a sufficient condition of nullity of the Iwasawa invariants lambda, mu, when p totally splits in k, and we obtain important tables of quadratic fields and p for which we can conclude that lambda = mu=0.We show that the number of ambiguous p-classes of kn (nth stage in k$\infty$) is equal to the order of the torsion group T, of the Galois group of the maximal Abelian p-ramified pro-p-extension of k (Theorem 4.2), for all n \textgreater{}\textgreater{} e, where p^e is the exponent of U*/ adh(E) (in terms of local and global units of k). Then we establish analogs of Chevalley's formula using a family (Lambda\_i^n)\_{0$\le$i$\le$m\_n} of subgroups of k* containing E, in which any x is norm of an ideal of kn. This family is attached to the classical filtration of the p-class group of kn defining the algorithm of computation of its order in m\_n steps. From this, we prove (Theorem 6.1) that m\_n $\ge$ (lambda.n + mu.p^n + nu)/v\_p(T\_k) and that the condition m\_n = O(1) (i.e., lambda = mu=0) essentially depends on the P-adic valuations of the (x^(p-1)-1)/p, x in Lambda\_i^n, for P I p, so that Greenberg's conjecture is strongly related to "Fermat quotients" in k*. Heuristics and statistical analysis of these Fermat quotients (Sections 6, 7, 8) show that they follow natural probabilities, linked to T\_k whatever n, suggesting that lambda = mu=0 (Heuristics 7.1, 7.2, 7.3). This would imply that, for a proof of Greenberg's conjecture, some deep p-adic results (probably out of reach now), having some analogy with Leopoldt's conjecture, are necessary before referring to the sole algebraic Iwasawa theory.

Assessment of Head Displacement and Disassembly Force With Increasing Assembly Load at the Head/Trunnion Junction of a Total Hip Arthroplasty Prosthesis

BackgroundMost femoral components used now for total hip arthroplasty are modular, requiring a strong connection at assembly. The aim of this study was to assess the effect of assembly force on the strength of head-trunnion interface and to measure the initial displacement of the head on the trunnion with different assembly forces. MethodsThree assembly load levels were assessed (A: 2 kN, B: 4 kN, C: 6 kN) with 4 implants in each group. The stems were mounted in a custom rig and the respective assembly loads were applied to the head at a constant rate of 0.05 kN/s (ISO7260-10:2003). Load levels were recorded during assembly. Head displacement was measured with a laser sensor. The disassembly force was determined by a standard pull-off test. ResultsThe maximum head displacement on the trunnion was significantly different between the 2 kN group and the other 2 groups (4 kN, 6 kN, P = .029), but not between the 4 kN and 6 kN groups (P = .89). The disassembly forces between the 3 groups were significantly different (mean ± standard deviation, A: 1316 ± 223 kN; B: 2224 ± 151 kN; C: 3965 ± 344 kN; P = .007), with increasing assembly load leading to a higher pull-off force. For the 4 kN and 6 kN groups, a first peak of approximately 2.5 kN was observed on the load recordings during assembly before the required assembly load was eventually reached corresponding to sudden increase in head displacement to approximately 150 μm. ConclusionAn assembly force of 2 kN may be too low to overcome the frictional forces needed to engage the head and achieve maximum displacement on the trunnion and thus an assembly load of greater than 2.5 kN is recommended.

Genome-wide identification, characterization, and expression analysis of the dehydrin gene family in Asian pear (Pyrus pyrifolia)

Dehydrins (DHNs) are a complex family of plant proteins that play an important role in protection of higher plant cells from dehydration and desiccation damage during environmental stresses, such as drought, high salinity, and low temperature. However, information on DHN genes of Asian pear (Pyrus pyrifolia), an economically important fruit crop grown in temperate regions in East Asia, e.g., China and Japan, is limited. To gain insights into this gene family in pear and to elucidate their roles in floral buds under low-temperature conditions, we performed a genome-wide identification, characterization, and expression analysis of DHN genes. Seven PpDHN genes were identified. Sequence alignment analysis of all putative proteins from these genes showed that all of the proteins contained a typical K-domain. These genes were categorized into SKn, YnSKn, YKn, and Kn groups based on gene characterization and phylogenetic relationships. Hierarchical cluster analyses showed that in non-stressed pear, PpDHN genes were expressed in all vegetative tissues except young leaves and shoot tips, in which PpDHN1, PpDHN2, and PpDHN4 were not expressed. Transcript levels of four PpDHN genes increased significantly in floral buds in response to low-temperature treatment, which indicated that they play important roles during stress adaptation. This study provides evidence that the family of pear DHN genes may function in tissue development and stress responses. The data will be valuable for further studies of the functions of DHN genes under different stress conditions in pear.

On the class numbers of the fields of the [formula omitted]-torsion points of certain elliptic curves over [formula omitted

Let E be an elliptic curve over Q with prime conductor p. For each positive integer n we put Kn:=Q(E[pn]). The aim of this paper is to estimate the order of the p-Sylow group of the ideal class group of Kn. We give a lower bound in terms of the Mordell–Weil rank of E(Q). As an application of our result, we give an example such that p2n divides the class number of the field Kn in the case of p=5077 for each positive integer n.

Improvement of Large Animal Model for Studying Osteoporosis

Abstract The aim of the study was to determine the impact of steroidal medications on the structure and mechanical properties of supporting tissues of sheep under experimentally-induced osteoporosis. A total of 21 sheep were used, divided into three groups: a negative control (KN) (n = 3), a positive control (KP) (n = 3) with ovariectomy, and a steroidal group (KS) (n = 15) with ovariectomy and glucocorticosteroids. All animals were kept on a low protein and mineral diet and had limited physical activity and access to sunlight. Quantitative computed tomography was the examination method. The declines in the examined parameter values in the KS group were more than three times higher than in the KN group. The study suggests that a glucocorticosteroidal therapy accelerates and intensifies processes taking place in the course of osteoporosis. The combination of glucocorticosteroids with ovariectomy, a restrictive diet, limited physical activity, and no access to sunlight leads to a decrease in radiological bone density.

Renal lymph circulation blockage alters the epithelial cell phenotype and tubular integrity: role of distinct regulation of BMP7 and TGF-β/Smads signaling pathway

To investigate the effect of lymph circulation blockage on the alteration of renal epithelial cell phenotype and the tubular integrity, as well as the underlying mechanisms. Wistar rats received left renal lymph ligation and right renal nephrectomy (KL group) or right renal nephrectomy without lymph ligation (KN group) and then were killed on day 14, day 28 and day 56. The urine, blood and kidney tissue were collected for the analysis of protein and gene expressions and morphological changes. The urine albumin and serum creatinine (Cr) in KL group were significantly increased compared with KN group. Masson and PAS staining indicated the epithelial cell degeneration, necrosis, sublethal loss and atrophy in KL rats, but not in KN group. Interestingly, from the atrophic tubules, some epithelial cells exhibited polarity changes with hypertrophy contrasting to the normal epithelial morphology of KN group throughout the experiment. By EM, ligated kidneys showed irregularly wrinkled basement membranes and epithelial cell swelling. Some intertubular areas of the KL kidney were expanded with fibrotic matrix and fibroblast-like cells. In line with these morphological changes, the fibroblast cell markers of FSP1 and α-SMA were markedly increased in contrast to the remarkable reduction in epithelial cell marker E-cadherin and tight junction protein ZO-1. Moreover, the TGF-β1/Smad2/3 signaling pathway was significantly activated in KL rats in contrast to a robust downregulation of BMP7/Smad5 signaling. Disturbance of renal lymphatic circulation resulted in the epithelial cell phenotypic alteration and impaired tubular integrity possibly via distinct regulation of TGFβ1/Smads and BMP7/Smad5 signaling pathway.

Diagonal forms and zero-sum (mod 2) bipartite Ramsey numbers

Let G be a subgraph of a complete bipartite graph Kn,n. Let N(G) be a 0-1 incidence matrix with edges of Kn,n against images of G under the automorphism group of Kn,n. A diagonal form of N(G) is found for every G, and the question as to whether the row space of N(G) over Zp contains the vector of all 1's is settled. This implies a new proof of Caro and Yuster's results on zero-sum bipartite Ramsey numbers, and provides necessary and sufficient conditions for the existence of a signed bipartite graph design.

Kinetin inhibits apoptosis of aging spleen cells induced by D-galactose in rats.

Kinetin (Kn) is a cytokinin growth factor that exerts several anti-aging and antioxidant effects on cells and organs. To investigate the mechanism underlying apoptotic events in aging cells induced by D-galactose (D-gal), we examined the effect of Kn delivered via nuchal subcutaneous injection on D-gal-induced aging and apoptosis in rats. Our results showed that interleukin (IL)-2 levels and mitochondrial membrane potential (ΔΨm) were decreased by Kn in aging rats while IL-6 production and apoptosis increased. In addition, the expression of anti-apoptotic Bcl-2 was low while that of Bax was high in the aging group. After treated with Kn, compared with aging group, there showed obvious difference in Kn group with elevated IL-2, proliferation index, Bcl-2, ΔΨm and decreased IL-6 and Bax in splenic lymphocyte. Based on these results, we concluded that Kn can effectively protect the rat spleen from aging, apoptosis, and atrophy.

Automorphisms of the graph of free splittings

We prove that every simplicial automorphism of the free splitting graph of a free group Fn is induced by an outer automorphism of Fn for n ≥ 3. In this note we consider the graph Gn of free splittings of the free group Fn of rank n ≥ 3. Loosely speaking, Gn is the graph whose vertices are non-trivial free splittings of Fn up to conjugacy, and where two vertices are adjacent if they are represented by free splittings admitting a common refinement. The group Out(Fn) of outer automorphisms of Fn acts simplicially on Gn. Denoting by Aut(Gn) the group of simplicial automorphisms of the free splitting graph, we prove: Theorem 1. The natural map Out(Fn)→ Aut(Gn) is an isomorphism for n ≥ 3. We briefly sketch the proof of Theorem 1. We identify Gn with the 1skeleton of the sphere complex Sn and observe that every automorphism of Gn extends uniquely to an automorphism of Sn. It is due to Hatcher [4] that the sphere complex contains an embedded copy of the spine Kn of Culler-Vogtmann space. We prove that the latter is invariant under Aut(Sn), and that the restriction homomorphism Aut(Sn) → Aut(Kn) is injective. The claim of Theorem 1 then follows from a result of Bridson-Vogtmann [1] which asserts that Out(Fn) is the full automorphism group of Kn. Before concluding this introduction we would like to point out that recently Martino and Francaviglia [9] have proved that Out(Fn) is also the full isometry group of Culler-Vogtmann space when the latter is endowed with the Lipschitz metric. While one could claim that Theorem 1 is the analogue of Ivanov’s theorem on the isometries of the curve complex [6], the result of Martino and Francaviglia is the analogue of Royden’s theorem on the isometries of Teichmuller space [10]. The first author was partially supported by M.E.C. grant MTM2006/14688 and NUI Galway’s Millennium Research Fund; the second author was partially supported by NSF grant DMS-0706878 and Alfred P. Sloan Foundation.

Cyclicity of the unramified Iwasawa module

For a number field k and a prime number p, let k∞ be the cyclotomic Zp-extension of k with finite layers kn. We study the finiteness of the Galois group X∞ over k∞ of the maximal abelian unramified p-extension of k∞ when it is assumed to be cyclic. We then focus our attention to the case where p = 2 and k is a real quadratic field and give the rank of the 2-primary part of the class group of kn. As a consequence, we determine the complete list of real quadratic number fields for which X∞ is cyclic non trivial. We then apply these results to the study of Greenberg’s conjecture for infinite families of real quadratic fields thus generalizing previous results obtained by Ozaki and Taya.

Galacto-oligosaccharides and bowel function

Background: Menopause induces various metabolic disorders due to the rapid decrease of the ovarian hormone estrogen. It is involved in increased risk of obesity, diabetes, dyslipidemia, and osteoporosis. The pigmented giant embryo cultivar is a promising food product for menopause-induced metabolic disorders. Objective: The effects of non-germinated and germinated Keunnunjami, a new blackish purple pigmented rice with a giant embryo, on glucose and bone metabolisms in ovariectomized rats were investigated. Design: The animals were fed with normal control diet (NC group) or control diet supplemented with either non-germinated Keunnunjami (KN group) or germinated Keunnunjami (GKN group) powder for 8 weeks. Results: The blood glucose and plasma insulin levels, adipokine concentrations, hepatic glucose-regulating enzyme activities, and bone resorption biomarker levels significantly decreased in KN and GKN groups compared to those of the control animals. Discussion: These findings illustrate that GKN group showed greater hypoglycemic activity and lower bone resorption than KN group, suggesting that germination could further improve the physiological property of Keunnunjami. Conclusion: Germinated Keunnunjami may have therapeutic potential against hyperglycemia and bone turnover imbalance caused by menopause.

Automorphisms of Coxeter groups of type K n

A Coxeter system (W, S) is said to be of type Kn if the associated Coxeter graph ΓS is complete on n vertices and has only odd edge labels. If W satisfies either of: (1) n = 3; (2) W is rigid; then the automorphism group of W is generated by the inner automorphisms of W and any automorphisms induced by ΓS. Indeed, Aut(W) is the semidirect product of Inn(W) and the group of diagram automorphisms, and furthermore W is strongly rigid. We also show that if W is a Coxeter group of type Kn then W has exactly one conjugacy class of involutions and hence Aut(W) = Spec(W).

Can Mesenchymal Stem Cells Survive Under Normal Impaction Force in Revision Total Hip Replacements?

Impaction allograft as a scaffold for bone-forming cells is a tissue-engineering approach for filling bone defects that are commonly encountered during revision total joint replacement (THR). The purpose of this in vitro study is to assess the viability of mesenchymal stem cells (MSC) grown on allograft following impaction using forces similar to those measured during revision total hip replacements. Impaction forces of 0, 3, 6, and 9 kN were used representing normal and high impact. The results showed that the viability in the 3 and 6 kN groups was not significantly reduced compared with that of the 0 kN group, while the survival of the MSCs was significantly reduced after 9 kN impaction force. This study suggests that the addition of MSCs to the allograft scaffold will survive normal impaction force in revision THR.

Hyperkalemia in very low birthweight infants: incidence and associated factors

The present study evaluated the incidence of hyperkalemia in premature babies born at the Hospital de Clínicas de Porto Alegre (birthweight <or= 1250 grams and gestational age <or= 32 weeks) during the first 72 hours of life in a one year period. The incidence of hyperkalemia was of 38.5% (potassium levels >or=6 mEq/l) and 15.4% with potassium levels subject to cardiac arrhythmia (>or= 6.7 mEq/l). The population was divided into two groups: group KN with potassium < 6 mEq/l (n=16) and group KE with potassium >or= 6 mEq/l (n=10). The hydroelectrolyte management and maintenance of neutral thermal environment was the same for both groups. Neither group received potassium in the first 36 hours of life. The KE group presented higher potassium levels during all the study. The mean birthweights of the groups were similar (KN = 963 gr; KE = 987 gr). The KN group presented a mean gestational age (29.3 weeks x 30.8 weeks) and Apgar Score in the first minute of life (3.18 x 5.7) significantly lower (p = 0.004 and p = 0,015 respectively) than the KE group. There were no significant differences between both groups in relation to the intraventricular hemorrhage, acidosis, hialine membrane disease, insulin level, glycemia, glycemia/insulin index, glomerular filtration rate, diurese, urinary potassium level, fractional sodium excretion, fractional potassium excretion and aldosterone tubular index. The level of aldosterone was significantly higher in the KE group (p = 0.029) within 24 hours of life (212.8 ng/dl x 110.2 ng/dl). It is suggested that none of the studied factors is responsible for the non-oliguric hyperkalemia of the very low birthweight newborn infant, stressing, however, that the serum potassium level must be carefully controlled in those infants.