Estimation of activity of pharmakopeal disinfectants and antiseptics against Gram-negative and Gram-positive bacteria isolated from clinical specimens, drugs and environment

The MIC of nine different disinfectants and antiseptics were determined for the Gram-negative and Gram-positive bacteria. Strains originated from clinical specimens, drugs and environment. A sensitivity was determined against chlorhexidinum digluconate (Gram-negative: 0,625-80 mg/L, Gram-positive: 0,3-10 mg/L), benzalconium chloride (Gram-negative: 2,5-1280 mg/L, Gram-positive: 1,25-20 mg/L), salicilic acid (Gram-negative and Gram-positive: 400-1600 mg/L), benzoic acid (Gram-negative: 800-1600 mg/L, Gram-positive: 400-1 600 mg/L), boric acid (Gram-negative: 800-12 800 mg/L, Gram-positive: 1 600-6400 mg/L), chloramine B (Gram-negative: 1600-6400 mg/L, Gram-positive:800- 6400 mg/L), jodine (Gram-negative: 200-1600 mg/L, Gram-positive: 200-1600 mg/L), etacridine lactate (Gram-negative: 40 do > 20480 mg/L, Gram-positive: 40-1280 mg/L) and resorcine (Gram-negative: 1600-6400 mg/L, Gram-positive: 800-6400 mg/L). Diversified values of MIC for different strains were obtained, especially in the case of benzalconium chloride, etacridine lactate, chlorhexidinum digluconate, boric acid and iodine. Strains isolated from environment were usually more susceptible to examined compounds than clinical strains. The biggest diversification of sensitivity was observed among strains originated from drugs where besides sensitive appeared strains characterizing by very high MIC values of some substances, eg. boric acid.     

A new species of the genus Haba Semenov, 1954 (Hymenoptera: Chrysididae) from Iran,with a key to species

Haba persica Strumia & Fallahzadeh sp. n. (Hymenoptera: Chrysididae: Elampini), from mountains in southwestern Iran, is described and illustrated.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:9D537878-6215-4874-8970-7F7DE8F57422     

Evaluation of five elements in lenses and aqueous humour of experimental rabbits after induced opacity

We evaluated the presence of Ca, Na, K, Cu and Zn in the lenses and aqueous humour of rabbits treated with an Nd:YAG laser to induce opacity of the crystalline. The mean concentrations of the elements found in control lenses were: Ca: 15.8+/-5.2 mg/kg; Na: 1.2+/-0.6 g/kg; K: 10.3+/-3.3 g/kg; Cu: 0.19+/-0.06 mg/kg; Zn: 20.6+/-3.0 mg/kg. With the exception of K and Zn, the values found in the lenses of treated eyes (Ca: 135+/-24 mg/kg; Na: 4.3+/-1.5 g/kg; K: 10.1 +/- 3.2 g/kg; Cu: 0.47+/-0.17 mg/kg; Zn: 21.8+/-4.2 mg/kg) were significantly higher than in the controls. On the other hand, the concentrations found in the aqueous humour of treated eyes (Ca: 21.7+/-4.5 mg/l; Na: 0.66+/-0.21 g/l; K: 0.29+/-0.10 g/l; Cu: 0.035+/-0.009 mg/l; Zn: 0.079+/-0.01 mg/l) were significantly lower than those of the controls. The greatest difference was observed for Na (-68.6%) and Cu (-52.7%), followed by Ca and Zn (-35.0% and -35.2%, respectively). A positive correlation was found between Ca and Na in treated lenses (r2 = 0.9226, p < 0.0001) whereas inverse correlations were found for both Ca (r2 = 0.9788, p<0.0001) and Na (r2 = 0.9491, p<0.0001) between the concentrations found in the lenses and in the aqueous humour of treated eyes.     

The -429 T/C and -374 T/A gene polymorphisms of the receptor of advanced glycation end products gene (RAGE) are not risk factors for coronary artery disease in Slovene population with type 2 diabetes

Receptor for advanced glycation end products (RAGE) plays a role in atherosclerosis in diabetics. There are two functional polymorphisms in the promoter of the RAGE gene (-429T/C and -374T/A). The aim of this study was to look for a relationship between the -429T/C and the -374T/A gene polymorphisms of the RAGE gene and the development of coronary artery disease (CAD) in the Slovene population with type 2 diabetes of duration longer than 10 years. One hundred and sixty-eight subjects with diabetes and CAD were compared to 241 diabetic subjects without CAD. The -429T/C and the -374T/A RAGE genotype distributions in patients with CAD (-429T/C: CC: 3%, TC: 31%, TT: 66.0%; -374T/A:AA: 7.7%, TA: 48.2%, TT: 44.1%) were not significantly different from those in patients without CAD (-429 T/C: CC: 1.7%, TC: 26.1%, TT: 72.2%; -374T/A: AA: 11.2%, TA: 43.2%, TT: 45.6%). Our study failed to demonstrate an association between either the -429T/C or the -374T/A gene polymorphism of the RAGE gene and CAD in the Slovene population with type 2 diabetes of duration longer than 10 years.     

Variance component tests of multivariate mediation effects under composite null hypotheses

Mediation effects of multiple mediators are determined by two associations: one between an exposure and mediators (‐) and the other between the mediators and an outcome conditional on the exposure (‐). The test for mediation effects is conducted under a composite null hypothesis, that is, either one of the ‐ and ‐ associations is zero or both are zeros. Without accounting for the composite null, the type 1 error rate within a study containing a large number of multimediator tests may be much less than the expected. We propose a novel test to address the issue. For each mediation test , , we examine the ‐ and ‐ associations using two separate variance component tests. Assuming a zero‐mean working distribution with a common variance for the element‐wise ‐ (and ‐) associations, score tests for the variance components are constructed. We transform the test statistics into two normally distributed statistics under the null. Using a recently developed result, we conduct hypothesis tests accounting for the composite null hypothesis by adjusting for the variances of the normally distributed statistics for the ‐ and ‐ associations. Advantages of the proposed test over other methods are illustrated in simulation studies and a data application where we analyze lung cancer data from The Cancer Genome Atlas to investigate the smoking effect on gene expression through DNA methylation in 15 114 genes.     

Endogenous phospholipids of swine liver: effect of fat deprivation on molecular species of phosphatidylcholine and phosphatidylethanolamine

Three 1-yr-old swine and two 2.5-wk-old swine were fed a fat-free diet for 1 month and 5 months, respectively. The hepatic phosphatidylcholine and phosphatidylethanolamine were fractionated by silver ion thin-layer chromatography. A distinctive feature of the chromatographic procedure was the development of the chromatograms at low temperatures: -10 degrees C for phosphatidylcholine and 4 degrees C for phosphatidylethanolamine. The chromatographic fractions were hydrolyzed with phospholipase A(2), and the fatty acids were characterized. Significant concentrations of odd-chain saturated and unsaturated fatty acids were found in the swine deprived of fat for 5 months. The major molecular species of phosphatidylcholine in both groups contained monoenoic fatty acids: 16:0/18:1(n - 9), 18:0/18:1(n - 9), and 18:1(n - 9)/18:1(n - 9). Their concentrations changed only slightly with the diet. The molecular species of phosphatidylethanolamine were more sensitive to dietary changes. In the swine deprived of fat for 1 month, about 50% of the molecular species of phosphatidylethanolamine contained tetraenoic fatty acids: 16:0/20:4(n - 6), 18:0/20:4(n - 6), and 18:1(n - 9)/20:4(n - 6). The phosphatidylethanolamine of animals deprived of fat for 5 months contained only 3% molecular species with tetraenoic acids, 18:0/20:4(n - 6), but 36% molecular species with trienoic acids: 18:0/20:3(n - 9), 18:1(n - 9)/20:3(n - 9), 18:0/19:3(n - 8), 16:0/20:3(n - 9), and 17:0/20:3(n - 9). Doubly unsaturated species, such as 18:1(n - 9)/18:1(n - 9), 18:1(n - 9)/20:3(n - 9), and 18:1(n - 9)/20:4(n - 6), were found in both groups of swine, although their total concentrations were higher in the group deprived of fat for a longer period.     

Visfatin: a putative biomarker for metabolic syndrome is not influenced by pioglitazone or simvastatin treatment in nondiabetic patients at cardiovascular risk -- results from the PIOSTAT study.

OBJECTIVE: The aim of the study was to analyze the effect of pioglitazone (PIO) and simvastatin (SIMVA) on adiponectin and visfatin concentrations in nondiabetic patients with metabolic syndrome and increased risk for cardiovascular complications in a prospective randomized clinical trial. RESEARCH DESIGN AND METHODS: One-hundred twenty-five nondiabetic patients with increased cardiovascular risk [78 females, 47 males, age (mean+/-STD:58.6+/-7.8years, BMI:30.8+/-4.2(kg/m2] were included after randomization to PIO+lacebo, SIMVA+placebo, or PIO+SIMVA treatment for 3 months. At baseline and endpoint, measurements of HbA1c, glucose, insulin, LDL cholesterol, adiponectin and visfatin were performed. Insulin resistance was assessed by means of the HOMAIR-score. RESULTS: Improvement in the HOMAIR-score was observed with PIO and the combination, but not with SIMVA alone, which was accompanied by an increase in adiponectin with PIO treatment groups, but a decrease with SIMVA alone (baseline/endpoint: PIO: 14.0+/-8.2 mg/l/ 27.6+/- 14.5 mg/l, p<0.05; PIO+SIMVA: 11.7+/-10.0 mg/l/26.7+/-15.7 mg/l, p<0.05; SIMVA: 15.5+/-12.7 mg/l/ 11.6+/-7.0 mg/l, p<0.05). No change could be observed in the visfatin concentrations (PIO: 47.6+/-14.5 ng/ml/48.0+/-11.6 ng/ml, PIO+SIMVA: 45.1+/-10.9 ng/ml/47.9+/-10.1 ng/ml, SIMVA: 49.2+/- 13.4 ng/ml/52.1+/-16.7 ng/ml, n. s. in all cases). CONCLUSIONS: Insulin resistance and/or cardiovascular risk indicators were not associated with visfatin levels. Regulation of visfatin secretion occurs through biochemical pathways independent from those influenced by pioglitazone or simvastatin.     

Biophysical analysis of the dynamics of calmodulin interactions with neurogranin and Ca2+/calmodulin‐dependent kinase II

Calmodulin (CaM) functions depend on interactions with CaM‐binding proteins, regulated by . Induced structural changes influence the affinity, kinetics, and specificities of the interactions. The dynamics of CaM interactions with neurogranin (Ng) and the CaM‐binding region of /calmodulin‐dependent kinase II (CaMKII_290−309) have been studied using biophysical methods. These proteins have opposite dependencies for CaM binding. Surface plasmon resonance biosensor analysis confirmed that and CaM interact very rapidly, and with moderate affinity ( ). Calmodulin‐CaMKII_290−309 interactions were only detected in the presence of , exhibiting fast kinetics and nanomolar affinity ( ). The CaM–Ng interaction had higher affinity under ‐depleted ( and k ₋₁ = 1.6 × 10⁻¹s⁻¹) than ‐saturated conditions ( ). The IQ motif of Ng (Ng₂₇₋₅₀) had similar affinity for CaM as Ng under ‐saturated conditions ( ), but no interaction was seen under ‐depleted conditions. Microscale thermophoresis using fluorescently labeled CaM confirmed the surface plasmon resonance results qualitatively, but estimated lower affinities for the Ng ( ) and CaMKII_290−309( ) interactions. Although CaMKII_290−309 showed expected interaction characteristics, they may be different for full‐length CaMKII. The data for full‐length Ng, but not Ng₂₇₋₅₀, agree with the current model on Ng regulation of /CaM signaling.     

Circulating miRs-183-5p, -206-3p and -381-3p may serve as novel biomarkers for 4,4’-methylene diphenyl diisocyanate exposure

Background: Occupational exposure to the most widely used diisocyanate, 4,4’-methylene diphenyl diisocyanate (MDI), is a cause of occupational asthma (OA). Early recognition of MDI exposure and sensitization is essential for the prevention of MDI-OA.

Objective: Identify circulating microRNAs (miRs) as novel biomarkers for early detection of MDI exposure and prevention of MDI-OA.

Materials and methods: Female BALB/c mice were exposed to one of three exposure regimens: dermal exposure to 1% MDI in acetone; nose-only exposure to 4580?±?1497?μg/m³ MDI-aerosol for 60?minutes; or MDI dermal exposure/sensitization followed by MDI-aerosol inhalation challenge. Blood was collected and miRCURY? miRs qPCR Profiling Service was used to profile circulate miRs from dermally exposed mice. Candidate miRs were identified and verified from mice exposed to three MDI-exposure regimens by TaqMan^® miR assays.

Results: Up/down-regulation patterns of circulating mmu-miRs-183-5p, -206-3p and -381-3p were identified and verified. Circulating mmu-miR-183-5p was upregulated whereas mmu-miRs-206-3p and -381-3p were downregulated in mice exposed via all three MDI exposure regimens.

Discussion and conclusion: Upregulation of circulating miR-183-5p along with downregulation of circulating miRs-206-3p and -381-3p may serve as putative biomarkers of MDI exposure and may be considered as potential candidates for validation in exposed human worker populations.     

New species and new records of Apataniidae (Insecta: Trichoptera) from east central China

Three new species of Apataniidae from China, Apatania protracta sp. n., Apatidelia paramartynovi sp. n., and Moropsyche dawuensis sp. n. are described and illustrated. We also report Apatania semicircularis Leng and Yang, 1998 for the first time from Hubei Province.

Apatania protracta: http://zoobank.org/urn:zoobank.org:pub:8317EB90-9316-4F7B-94C6-65938A6F2873

Apatidelia paramartynovi: http://zoobank.org/urn:zoobank.org:pub:8741CE6F-B339-4842-BD8C-04BE8B21A222

Moropsyche dawuensis: http://zoobank.org/urn:zoobank.org:pub:B5CB815D-59B5-401F-9308-9EE24A9BBAF7     

Contemporary effective population and metapopulation size (Ne and meta‐Ne): comparison among three salmonids inhabiting a fragmented system and differing in gene flow and its asymmetries

We estimated local and metapopulation effective sizes ( and meta‐) for three coexisting salmonid species (Salmo salar, Salvelinus fontinalis, Salvelinus alpinus) inhabiting a freshwater system comprising seven interconnected lakes. First, we hypothesized that might be inversely related to within‐species population divergence as reported in an earlier study (i.e., F_ST: S. salar> S. fontinalis> S. alpinus). Using the approximate Bayesian computation method implemented in ONeSAMP, we found significant differences in () between species, consistent with a hierarchy of adult population sizes (). Using another method based on a measure of linkage disequilibrium (LDNE: ), we found more finite values for S. salar than for the other two salmonids, in line with the results above that indicate that S. salar exhibits the lowest among the three species. Considering subpopulations as open to migration (i.e., removing putative immigrants) led to only marginal and non‐significant changes in , suggesting that migration may be at equilibrium between genetically similar sources. Second, we hypothesized that meta‐ might be significantly smaller than the sum of local s (null model) if gene flow is asymmetric, varies among subpopulations, and is driven by common landscape features such as waterfalls. One ‘bottom‐up’ or numerical approach that explicitly incorporates variable and asymmetric migration rates showed this very pattern, while a number of analytical models provided meta‐ estimates that were not significantly different from the null model or from each other. Our study of three species inhabiting a shared environment highlights the importance and utility of differentiating species‐specific and landscape effects, not only on dispersal but also in the demography of wild populations as assessed through local s and meta‐s and their relevance in ecology, evolution and conservation.     

E2F1 and p53 are dispensable, whereas p21(Waf1/Cip1) cooperates with Rb to restrict endoreduplication and apoptosis during skeletal myogenesis

We describe temporal and genetic analyses of partially rescued Rb mutant fetuses, mgRb:Rb-/-, that survive to birth and reveal specific defects in skeletal muscle differentiation. We show that in the absence of Rb, these fetuses exhibit increased apoptosis, bona fide endoreduplication, and incomplete differentiation throughout terminal myogenesis. These defects were further augmented in composite mutant fetuses, mgRb:Rb-/-:p21-/-, lacking both Rb and the cyclin-dependent kinase inhibitor p21(Waf1/Cip1). Although E2F1 and p53 mediate ectopic DNA synthesis and cell death in several tissues in Rb mutant embryos, both endoreduplication and apoptosis persisted in mgRb:Rb-/-:E2F1-/- and mgRb:Rb-/-:p53-/- compound mutant muscles. Thus, combined inactivation of Rb and p21(Waf1/Cip1) augments endoreduplication and apoptosis, whereas E2F1 and p53 are dispensable during aberrant myogenesis in Rb-deficient fetuses.     

Exploring potential induction of grapevine (Vitis spp.) root phenolic compounds by ring nematodes,Mesocriconema xenoplax

This paper explored the fixed point results for the mappings satisfying generalized weak contractive conditions in a complete partially ordered b-metric space. These contractions are some variations of the work done by the authors (Mituku et al. in BMC Res Notes 13:537. https://doi.org/10.1186/s13104-020-05354-1 , 2020; Seshagiri et al. in BMC Res Notes 13:451. https://doi.org/10.1186/s13104-020-05273-1 , 2020, BMC Res Notes 14:390. https://doi.org/10.1186/s13104-021-05801-7 , 2021, BMC Res Notes 14:263. https://doi.org/10.1186/s13104-021-05649-x , 2021) in the same context. To validate the results a few examples are provided. The aim of this work is to prove some fixed point results of the self mappings in ordered b-metric space satisfying variant generalized weak contraction conditions. These results generalize some known results in the provided literature.     

Plant complex type free N-glycans occur in tomato xylem sap

Free N-glycans (FNGs) are ubiquitous in growing plants. Further, acidic peptide:N-glycanase is believed to be involved in the production of plant complex-type FNGs (PCT-FNGs) during the degradation of dysfunctional glycoproteins. However, the distribution of PCT-FNGs in growing plants has not been analyzed. Here, we report the occurrence of PCT-FNGs in the xylem sap of the stem of the tomato plant.

Abbreviations: RP-HPLC: reversed-phase HPLC; SF-HPLC: size-fractionation HPLC; PA-: pyridylamino; PCT: plant complex type; Hex: hexose; HexNAc: N-acetylhexosamine; Pen: pentose; Deoxyhex: deoxyhexose; Man: D-mannose; GlcNAc: N-acetyl-D-glucosamine; Xyl: D-xylose; Fuc: L-fucose; Le^a: Lewis a (Galβ1-3(Fucα1-4)GlcNAc); PCT: plant complex type; M3FX: Manα1-6(Manα1-3)(Xylβ1-2)Manβ1-4GlcNAcβ1-4(Fucα1-3)GlcNAc-PA; GN2M3FX: GlcNAcβ1-2Manα1-6(GlcNAcβ1-2Manα1-3)(Xylβ1-2)Manβ1-4GlcNAcβ1-4(Fucα1-3)GlcNAc-PA; (Le^a)1GN1M3FX: Galβ1-3(Fucα1-4)GlcNAc1-2 Manα1-6(GlcNAcβ1-2Manα1-3)(Xylβ1-2)Manβ1-4GlcNAcβ1-4(Fucα1-3)GlcNAc-PA or GlcNAc1-2Manα1-6(Galβ1-3(Fucα1-4)GlcNAc1-2Manα1-3)(Xylβ1-2)Manβ1-4GlcNAcβ1-4(Fucα1-3)GlcNAc-PA.     

MATERNAL INHERITANCE AND ITS EFFECT ON ADAPTIVE EVOLUTION: A QUANTITATIVE GENETIC ANALYSIS OF MATERNAL EFFECTS IN A NATURAL PLANT POPULATION

A mother can influence a trait in her offspring both by the genes she transmits (Mendelian inheritance) and by maternal attributes that directly affect that trait in her offspring (maternal inheritance). Maternal inheritance can alter the direction, rate, and duration of adaptive evolution from standard Mendelian models and its impact on adaptive evolution is virtually unexplored in natural populations. In a hierarchical quantitative genetic analysis to determine the magnitude and structure of maternal inheritance in the winter annual plant, Collinsia verna, I consider three potential models of inheritance. These range from a standard Mendelian model estimating only direct (i.e., Mendelian) additive and environmental variance components to a maternal inheritance model estimating six additive and environmental variance components: direct additive and environmental variances; maternal additive and environmental variances; and the direct-maternal additive () and environmental covariances. The structure of maternal inheritance differs among the 10 traits considered at four stages in the life cycle. Early in the life cycle, seed weight and embryo weight display substantial , a negative , and a positive . Subsequently, cotyledon diameter displays and of roughly the same magnitude and negative . For fall rosettes, leaf number and length are best described by a Mendelian model. In the spring, leaf length displays maternal inheritance with significant and and a negative . All maternally inherited traits show significant negative . Predicted response to selection under maternal inheritance depends on and as well as . Negative results in predicted responses in the opposite direction to selection for seed weight and embryo weight and predicted responses near zero for all subsequent maternally inherited traits. Maternal inheritance persists through the life cycle of this annual plant for a number of size-related traits and will alter the direction and rate of evolutionary response in this population.     

14-3-3 Binding to Cyclin Y contributes to cyclin Y/CDK14 association

Cyclin Y is a highly conserved cyclin among eumetazoans, yet its function and regulation are poorly understood. To search for Cyclin Y-interacting proteins, we screened a yeast two-hybrid library using human Cyclin Y （CCNY） as a bait and identified the following interactors： CDK14 and four members of the 14-3-3 family （ε,β,η,τ）. The interaction between CCNY and 14-3-3 proteins was confirmed both in vitro and in vivo. The results showed that Ser-100 and Ser-326 residues in CCNY were crucial for 14-3-3 binding. Interestingly, binding of CCNY to 14-3-3 significantly enhanced the association between CCNY and CDK14. Our findings may add a new layer of regulation of CCNY binding to its kinase partner.     

Papillonema danieli gen. et sp.n. and Papillonema clavatum (Gerlach, 1957) comb.n. (Nematoda,Desmodoridae) from the Ceriops mangrove sediments of Gazi Bay,Kenya

A new genus, Papillonema gen.n., is erected to accomodate the two species P. danieli gen. et sp. n. and P. clavatum (Gerlach, 1957) comb.n. from intertidal sediments of a tropical mangrove. Papillonema gen.n. is characterized by prominent papilliform labial sensillae, an elongate muscular terminal bulb (up to 60% of pharyngeal length), and three precloacal supplements. Comments are given on the use of the terms head capsule, head region, and cervical setae.Abbreviations a: body length divided by maximum body diameter - abd: anal body diameter - amph %: diameter of the amphid as a percentage of the corresponding head diameter - aw: amphidial width - b: body length divided by pharyngeal length - bdcs: body diameter at level of the cephalic setae - bdnr: body diameter at level of nerve ring - c: body length divided by tail length - cs: length of cephalic setae - da: distance from anterior to anus - dcs: distance from anterior edge to cephalic setae - dnr: distance from anterior edge to nerve ring - dv: distance from anterior to vulva - gub: length of the gubernaculum - hw: head width - L: body length - Isp: length of sperm cells - mbd: maximum body diameter - mbd ph: body diameter at level of pharynx - ph: pharyngeal length - spic: length of spicules measured along the arc - t: tail length - tmr: length of non-annulated tail end - V: position of vulva as a percentage of the total body length from anterior - wsp: width of sperm cells     

Effect of chronic salt loading on renal Na-K-ATPase activity in the rat

The effect of chronic salt loading in rats fed regular chow diet on renal Na-K-ATPase was studied. The high salt intake was associated with increased filtered load of sodium (control: 126 +/- 3.9 mueq/min, salt loaded: 146 +/- 2.5, mueq/min, P less than 0.001), increased net reabsorption of sodium (control: 125.3 +/- 3.9 mueq/min, salt load: 134.8 +/- 2.4 mueq/min, P less than 0.05), increased urinary excretion of potassium (control: 2.4 +/- 0.09 mueq/min/min; salt loaded: 3.0 +/- 0.1 mueq/min, P less than 0.001) and increase in single kidney weight (control: 0.798 +/- 0.010 g, salt loaded: 0.937 +/- 0.015 g, P less than 0.001). The above mentioned changes were associated with significant increase in renal microsomal and whole homogenate medullary Na-K-ATPase activity in the salt loaded group (microsomes: control 74.1 +/- 4.9 mumole Pi/mg prot/hr, salt loaded 112.7 +/- 6.0 mumole Pi/mg prot/hr, P less than 0.001; whole homogenate: control 22.7 +/- 1.0 mumole Pi/mg prot/hr, salt load 29.4 +/- 1.6 mumole Pi/mg prot/hr, P less than 0.005), while cortical and papillary Na-K-ATPase activity remained unchanged. Taken together, these results show that increased filtered and reabsorbed load of sodium, which follows high salt intake, is associated with an increased renal Na-K-ATPase activity. The preferential rise in medullary enzymatic activity may be interpreted as suggesting that these changes may stem from increased delivery and reabsorption of sodium in the ascending limb of Henle's loop.