Serum keratan sulphate as a cartilage metabolic marker in horses: the effect of exercise

Keratan sulphate (KS) concentration in sera from resting horses and horses training daily on a racetrack was measured by an inhibition enzyme-linked immunosorbent assay (ELISA) using anti-equine KS antibody 1/14/16H9. For the in-training horses, serum KS concentrations in 2-year-old-horses was significantly higher than 3- or 4-year-old-horses. A higher concentration of serum KS was found in the in-training group than in the long-term resting group in 2-year-old-horses. Serum KS concentration increased remarkably immediately after training in healthy horses, and at 1, 5, 9 and 24 h after training remained at similar levels to the pre-training concentration. The results suggest that serum KS concentration could represent the situation of joint loading, induced by daily racetrack training, affecting the metabolic activities in joint cartilage.

Development of an intelligent laboratory information system for community health promotion center

This study aimed to develop an Intelligent Laboratory Information System (ILIS) for the community health promotion center in Kwachun city to help process an increasing number of laboratory test data in an efficient manner, and to support the clinical decision-making of public health doctors. A sample of 170 cases was used for validation of the system. Overall, the system correctly predicted 92.5% of the cases. This paper also analyzed the economic feasibility of the ILIS based on the Information Economics approach. The results showed that the ILIS not only helps screen more people by increasing the capacity of a health promotion center, but also brings in more revenue to the center.

Regulation of the abundance of renal sodium transporters and channels by vasopressin

Vasopressin plays a role in both salt and water balance in the kidney. Classic studies, utilizing isolated perfused tubules, have revealed that vasopressin increases sodium reabsorption in the kidney thick ascending limb and the collecting duct. Furthermore, the activity of several sodium transport proteins expressed in these segments, such as the bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2) and the epithelial sodium channel (ENaC), have been shown to be directly increased by vasopressin. Increased protein abundance might be one means through which sodium transporter and channel activity is enhanced. We have used immunoblotting and immunohistochemistry in order to investigate the regulation of abundance of the major sodium transporters and channels expressed along the renal tubule in response to vasopressin. Chronic (7-day) studies were performed in which vasopressin levels were elevated either endogenously by water restriction of Sprague-Dawley rats or exogenously through infusion of the vasopressin V2-receptor-selective agonist, dDAVP (1-deamino-8d-arginine-vasopressin), to Brattleboro rats. We found a significant increase in protein abundance for NKCC2 and the beta- and gamma-subunits of ENaC with either water restriction or dDAVP infusion. The alpha-subunit of Na-K-ATPase was increased by water restriction, but not by dDAVP infusion, and alpha-ENaC and the thiazide-sensitive cotransporter (NCC) were increased by dDAVP infusion but not by water restriction. Acute (60-min) in vivo exposure to dDAVP led to an increase in both beta- and gamma-ENaC abundance in kidney cortex homogenates, displaying the rapid nature of some of these changes. Overall these increases in sodium transporter and channel abundances likely contribute to both the antidiuretic and antinatriuretic actions of vasopressin.

Clinical significance of the fractional excretion of anions in metabolic acidosis

The fractional excretion of anions has been proposed as a new index for the differential diagnosis of metabolic acidosis, identifying the properties of the conjugate base by examining the renal handling of the anion. Here, we investigated clinical significance of the fractional excretion of anions in pathophysiologic diagnosis of metabolic acidosis by measuring urine ammonium (NH4+) excretion, the ratio of A plasma anion gap/delta plasma HCO3- concentration (deltaAG/deltaHCO3-), and fractional excretion of anions in three different groups of metabolic acidosis: acid overproduction (8 patients with lactic acidosis, 8 with diabetic ketoacidosis, 3 with hippuric acidosis following glue sniffing), acid underexcretion (10 patients with chronic renal failure) and normal controls (10 normal volunteers who underwent 3-day NH4Cl loading). As expected, urine NH4+ excretion was higher in overproduction acidosis than in acid-loaded normal controls (88.1 +/- 12.3 vs. 54.0 +/- 3.7 mmol/day, p < 0.05), and it was lower in chronic renal failure than in acid-loaded normal controls (12.8 +/- 1.7 vs. 54.0 +/- 3.7 mmol/day, p < 0.05). The fractional excretion of anions had no difference between overproduction acidosis and chronic renal failure (41.2 +/- 42.8% vs. 41.0 +/- 8.1%). However, the fractional excretion of anions showed significant differences between the subgroups in acid overproduction (lactic acidosis, 4.7 +/- 0.3%; diabetic ketoacidosis, 45.8 +/- 3.1%; hippuric acidosis, 126.0 +/- 14.4%; p < 0.05). The ratio of plasma deltaAG/deltaHCO3- also exhibited significant differences between the subgroups in acid overproduction (lactic acidosis, 1.5 +/- 0.1; diabetic ketoacidosis, 1.0 +/- 0.1; hippuric acidosis, 0.3 +/- 0.1; p < 0.05). There was an inverse linear correlation between the fractional excretion of anions and the ratio of plasma deltaAG/deltaHCO3- (r2 =-0.89, p < 0.05). In conclusion, determination of the fractional excretion of anions may provide a useful clue to the differential diagnosis of metabolic acidosis caused by acid overproduction.

Life without a cell membrane: regeneration of protoplasts from disintegrated cells of the marine green alga Bryopsis plumosa

When the multi-nucleate giant cells of the green alga Bryopsis plumosa (Huds.) Ag. are injured, the protoplasm is extruded from the cells and can generate spontaneously numerous new cells. The cell organelles aggregate rapidly in seawater and become covered with a gelatinous envelope within 15 minutes. A lipid cell membrane is formed inside the envelope within 9 to 12 hours and about 15% of the original cell membrane is recycled to make the membrane of new protoplasts. Cytochemical studies using Nile Red and various enzymes revealed that the primary envelope is initially composed of polysaccharides, and then transformed into a polysaccharide-lipid complex. Fluorescein diacetate staining showed that the primary envelope has some characteristics of a cell membrane including semi-permeability and selective transport of materials. The aggregation of cell organelles appears to be mediated by two kinds of materials, one present in vacuolar sap and the other on the surface of the cell organelles. About a thousand new cells were generated from a single disintegrated branch and 40% of them eventually developed into mature plants.

Regulation of AQP6 mRNA and protein expression in rats in response to altered acid-base or water balance

In the rat, aquaporin-6 (AQP6) is mainly localized in intercalated cells (ICs) in collecting ducts, where it is exclusively associated with intracellular vesicles. In this study, we examined whether AQP6 protein and mRNA expression were regulated in the inner medulla or inner stripe of the outer medulla. Rats treated with dietary alkali or acid load for 7 days with a fixed daily water intake revealed appropriate changes in urine pH but unchanged urine output. AQP6 protein and mRNA abundance were increased in alkali-loaded rats (187 +/- 18 and 151 +/- 17% of control, respectively), whereas no changes were observed in acid-loaded rats. Immunohistochemistry revealed increased IC AQP6 labeling in alkali-loaded rats but not in acid-loaded rats. In contrast, administration of NH(4)Cl in the drinking water for 2 wk (free access to water) revealed a significant increase in AQP6 protein abundance (194 +/- 9% of control), but this was associated with increased water intake. Combined, this suggests that AQP6 expression was not affected by acid loading per se but rather was in response to changes in water intake. Consistent with this, water loading for 48 h was associated with increased AQP6 protein abundance, compared with thirsted rats. Moreover, rats with lithium-induced nephrogenic diabetes insipidus had a threefold increase in both AQP6 protein and mRNA expression. Overall, these results suggest that AQP6 expression in collecting duct ICs is regulated by altered acid/alkali load or water balance. Thus AQP6 may contribute to maintenance of acid-base homeostasis and water balance.

Expression and action of neurotropin-3 and nerve growth factor in embryonic and early postnatal rat testis development

The current study examines the expression and potential actions of neurotropin-3 (NT3), nerve growth factor (NGF), and their receptors during morphological sex determination (seminiferous cord formation) and perinatal rat testis development. The expression of neurotropins and their receptors was analyzed with immunohistochemistry. Cellular localization of neurotropin ligand and receptor proteins changed during embryonic testis development. Neurotropin-3 was localized to Sertoli cells at Embryonic Day 14 (E14), was present in gonocytes at Postnatal Day 0 (P0), and after birth became localized to the interstitium and Sertoli cells (P3-P5). The expression of trk C (the high affinity receptor for NT3) was localized to mesonephric ducts and cells surrounding the cords (E14-E18). In addition, Sertoli cells and preperitubular cells surrounding the cords at E14 also stained for trk C. Neurotropin-3 was expressed in gonocytes and Sertoli cells at P0-P5. Nerve growth factor was detected in Sertoli cells at E14, was clearly in Sertoli and interstitial cells at E16 and E18, and in Sertoli, germ, and interstitial cells from P0-P5. The expression of trk A (the high affinity receptor for NGF) was located in Sertoli and interstitial cells at E16-P5. To determine the actions of neurotropins during embryonic and perinatal testis development, experiments were conducted on E13 and P0 testis. Antisense oligonucleotide experiments with NT3 were used on E13 testis organ cultures to determine effects on seminiferous cord formation. Cord formation was inhibited in 40% of the organ cultures treated with the antisense NT3 oligonucleotides, while no inhibition was observed with sense oligonucleotides. In P0 testis cultures, both NT3 and NGF alone and in combination stimulated thymidine incorporation into DNA. Therefore, the neurotropins are involved in embryonic morphological events (cord formation; NT3) and in growth of the perinatal testis (P0; NT3 and NGF). To define further the growth effects of neurotropins on testis development, expression of transforming growth factor alpha and beta (TGF alpha and TGF beta) were examined in response to neurotropins. The P0 testis cultures were treated with neurotropins, and expression of mRNA for TGF alpha and TGF beta was analyzed utilizing a quantitative reverse transcription-polymerase chain reaction assay. Nerve growth factor and NT3 alone or in combination inhibited expression of mRNA for TGF alpha while NT3 increased mRNA expression of epidermal growth factor receptor. The combination treatment of neurotropins inhibited expression of TGF beta 1 and increase expression of TGF beta 3. In summary, observations suggest that NT3, NGF, trk A, and trk C are localized to cells critical to seminiferous cord formation and appear to be important regulators of morphological sex determination. In addition to these morphological effects, both NT3 and NGF stimulate P0 testis growth and may elicit their action through altering the expression of locally produced growth factors such as TGF alpha and TGF beta. Taken together these results suggest that neurotropins are regulators of paracrine cell-cell interactions that result in morphological sex determination and perinatal testis growth.

Evaluation of renal tubular functions in convalescent phase of hemorrhagic fever with renal syndrome

To evaluate renal tubular functions and to investigate the causative factors of urinary-concentrating defects in the late stage of hemorrhagic fever with renal syndrome (HFRS), 11 HFRS patients in the convalescent phase were studied and compared with 8 acute renal failure (ARF) patients in convalescence (disease controls) and 9 healthy adults preparing for kidney donation (normal controls, NC). Minimal urine osmolality induced by water loading was higher (p < 0.05) in HFRS (89.5 +/- 22.1 mosm/kg) and ARF patients (84.8 +/- 14.7 mosm/ kg) than in NC (47.8 +/- 4.6 mosm/kg), but the solute-free water clearance of HFRS patients (9.0 +/- 1.3%), measured at maximal diuresis, was not different from that of ARF patients (6.7 +/- 1.2%) or NC (10.5 +/- 1.4%). After 12-hour water deprivation + vasopressin stimulation, HFRS had lower urine osmolality (433.7 +/- 31.1 versus 850.0 +/- 35.1 mosm/kg; p < 0.05), urine-to-plasma osmolality ratio (1.47 +/- 0.11 versus 2.91 +/- 0.11; p < 0.05), and solute-free water reabsorption (0.53 +/- 0.07 versus 0.91 +/- 0.12%; p < 0.05) than NC. As compared with ARF patients (1.09 +/- 0.16%) or NC (1.49 +/- 0.16%), HFRS patients (0.43 +/- 0.20%) had lower solute-free water reabsorption measured at maximal antidiuresis induced by water deprivation + vasopressin stimulation + hypertonic saline infusion (p < 0.05). In HFRS, the plasma vasopressin level and plasma vasopressin/osmolality ratio increased from 3.9 +/- 0.8 to 6.1 +/- 1.1 pg/ml and from 0.013 +/- 0.003 to 0.020 +/- 0.004 pg/ml/mosm/kg after 12-hour water deprivation, respectively (p < 0.01). However, neither basal nor stimulated values of the plasma vasopressin level or plasma vasopressin/osmolality ratio was different among the 3 groups. HFRS patients were not different from ARF patients or NC in lithium clearance, urinary-acidifying capacity, and fractional excretions of sodium, potassium and bicarbonate. We conclude that in the convalescent phase of HFRS, the urinary-acidifying ability is not disturbed, the urinary-diluting defect is mild, and the urinary-concentrating capacity is obviously impaired. This study suggests that the most important factor contributing to the urinary-concentrating defect in HFRS is the reduced collecting duct responsiveness to vasopressin.

Long-term regulation of renal Na-dependent cotransporters and ENaC: response to altered acid-base intake

Increased systemic acid intake is associated with an increase in apical Na/H exchange in the renal proximal tubule mediated by the type 3 Na/H exchanger (NHE3). Because NHE3 mediates both proton secretion and Na absorption, increased NHE3 activity could inappropriately perturb Na balance unless there are compensatory changes in Na handling. In this study, we use semiquantitative immunoblotting of rat kidneys to investigate whether acid loading is associated with compensatory decreases in the abundance of renal tubule Na transporters other than NHE3. Long-term (i.e., 7-day) acid loading with NH(4)Cl produced large decreases in the abundances of the thiazide-sensitive Na-Cl cotransporter (TSC/NCC) of the distal convoluted tubule and both the beta- and gamma-subunits of the amiloride-sensitive epithelial Na channel (ENaC) of the collecting duct. In addition, the renal cortical abundance of the proximal type 2 Na-dependent phosphate transporter (NaPi-2) was markedly decreased. In contrast, abundances of the bumetanide-sensitive Na-K-2Cl cotransporter of the thick ascending limb and the alpha-subunit of ENaC were unchanged. A similar profile of changes was seen with short-term (16-h) acid loading. Long-term (7-day) base loading with NaHCO(3) resulted in the opposite pattern of response with marked increases in the abundances of the beta- and gamma-subunits of ENaC and NaPi-2. These adaptations may play critical roles in the maintenance in Na balance when changes in acid-base balance occur.

Identification of four novel mutations in five unrelated Korean families with Fabry disease

Fabry disease is a X-linked recessively inherited metabolic disorder, which results from the deficient activity of the lysosomal hydrolase alpha-galactosidase A leading to the systemic deposition of glycosphingolipids with terminal alpha-galactosyl moieties. Single-strand conformation polymorphism (SSCP) analysis was performed, followed by DNA sequencing of PCR amplified exons of the human alpha-galactosidase A gene in 5 unrelated Korean patients with classic Fabry disease. Five different mutations were identified; two nonsense mutations (Y86X and R342X), one missense mutation (D266N), and two small deletions (296del2 and 802del4). Except for R342X mutation, four were novel mutations (Y86X, D266N, 296del2, 802del4). A T to G transversion at nucleotide position 5157 in exon 2 caused a tyrosine-to-stop substitution at codon 86. A G to A transition at position 10287 in exon 5 substituted an asparagine for an aspartate at codon 266. Mutation 296del2 in exon 2 resulted in a frame shift with a stop signal at the 22th codon downstream from the mutation, whereas mutation 802del4 resulted in a stop codon at the site of 4 bp deletion. In addition, the 802del4 was found to be a de novo mutation. This is the first report on mutation analysis of the human alpha-galactosidase A gene in Korean patients with Fabry disease.

Vasopressin-mediated regulation of epithelial sodium channel abundance in rat kidney

Sodium transport is increased by vasopressin in the cortical collecting ducts of rats and rabbits. Here we investigate, by quantitative immunoblotting, the effects of vasopressin on abundances of the epithelial sodium channel (ENaC) subunits (alpha, beta, and gamma) in rat kidney. Seven-day infusion of 1-deamino-[8-D-arginine]-vasopressin (dDAVP) to Brattleboro rats markedly increased whole kidney abundances of beta- and gamma-ENaC (to 238% and 288% of vehicle, respectively), whereas alpha-ENaC was more modestly, yet significantly, increased (to 142% of vehicle). Similarly, 7-day water restriction in Sprague-Dawley rats resulted in significantly increased abundances of beta- and gamma- but no significant change in alpha-ENaC. Acute administration of dDAVP (2 nmol) to Brattleboro rats resulted in modest, but significant, increases in abundance for all ENaC subunits, within 1 h. In conclusion, all three subunits of ENaC are upregulated by vasopressin with temporal and regional differences. These changes are too slow to play a major role in the short-term action of vasopressin to stimulate sodium reabsorption in the collecting duct. Long-term increases in ENaC abundance should add to the short-term regulatory mechanisms (undefined in this study) to enhance sodium transport in the renal collecting duct.

Renal expression of two 'thyroid-specific' genes: thyrotropin receptor and thyroglobulin

Numerous renal abnormalities accompany thyroid disease, most of which have been ascribed to the effects of thyroid hormone on renal metabolism. In the present report, we investigate the renal expression of the nominally thyroid-specific proteins, thyroid-stimulating hormone (TSH) receptor (TSHR) and thyroglobulin (Tg), as potential links between renal and thyroid function. The expression of TSHR has been identified in several extrathyroidal tissues, but its presence in the kidney remains controversial. We have used reverse-transcriptase polymerase chain reaction and DNA sequencing to demonstrate the presence of TSHR transcript in human and mouse kidney, in a primary culture of human kidney, and in a green monkey kidney epithelioid cell line. Furthermore, human kidney cells responded to TSH with a 2.5- fold increase in intracellular cyclic adenosine monophosphate, suggesting the presence of functional TSHR protein. Comparison of renal expression of TSHR in a bovine growth hormone transgenic mouse model of progressive glomerulosclerosis with control mice suggested increased TSHR transcript in the renal cortex of transgenic animals. TSHR transcript was also detected in mouse mesangial cells in vitro which responded to TSH with significant increases in the formation of three-dimensional hillhocks. Polymerase chain reaction also confirmed the presence of Tg transcript in human and mouse kidneys and in mouse mesangial cells, but no effect of either TSH or cyclic adenosine monophosphate on Tg transcript levels could be discerned. Immunofluorescent staining with a monoclonal anti-Tg antibody identified positive staining in the cytoplasm of mesangial cells. These data suggest that the kidney is capable of expressing the thyroid-specific genes, TSHR and Tg, which could conceivably mediate effects of thyroid disease in the kidney.

UT-A2: a 55-kDa urea transporter in thin descending limb whose abundance is regulated by vasopressin

The renal urea transporter gene (UT-A) produces different transcripts in the inner medullary collecting ducts (UT-A1) and thin descending limbs of Henle's loop (UT-A2), coding for distinct proteins. Peptide-directed rabbit polyclonal antibodies were used to identify the UT-A2 protein in renal medulla of mouse and rat. In the inner stripe of outer medulla, an antibody directed to the COOH terminus of UT-A recognized a membrane protein of 55 kDa. The abundance of this 55-kDa protein was strongly increased in response to chronic infusion of the vasopressin analog 1-deamino-[8-D-arginine]vasopressin (DDAVP) in Brattleboro rats, consistent with previous evidence that UT-A2 mRNA abundance is markedly increased. Immunofluorescence labeling with the COOH-terminal antibody in Brattleboro rats revealed labeling in the lower portion of descending limbs from short-looped nephrons (in the aquaporin-1-negative portion of this segment). This UT-A labeling was increased in response to DDAVP. Increased labeling was also seen in descending limbs of long-looped nephrons in the base of the inner medulla. These results indicate that UT-A2 is expressed as a 55-kDa protein in portions of the thin descending limbs of Henle's loop and that the abundance of this protein is strongly upregulated by vasopressin.

Thickness-profile measurement of transparent thin-film layers by white-light scanning interferometry

White-light scanning interferometry is increasingly used for precision profile metrology of engineering surfaces, but its current applications are limited primarily to opaque surfaces with relatively simple optical reflection behavior. A new attempt is made to extend the interferometric method to the thickness-profile measurement of transparent thin-film layers. An extensive frequency-domain analysis of multiple reflection is performed to allow both the top and the bottom interfaces of a thin-film layer to be measured independently at the same time by the nonlinear least-squares technique. This rigorous approach provides not only point-by-point thickness probing but also complete volumetric film profiles digitized in three dimensions.

Aldosterone-mediated regulation of ENaC alpha, beta, and gamma subunit proteins in rat kidney

Aldosterone stimulates sodium transport in the renal collecting duct by activating the epithelial sodium channel (ENaC). To investigate the basis of this effect, we have developed a novel set of rabbit polyclonal antibodies to the 3 subunits of ENaC and have determined the abundance and distribution of ENaC subunits in the principal cells of the rat renal collecting duct. Elevated circulating aldosterone (due to either dietary NaCl restriction or aldosterone infusion) markedly increased the abundance of alphaENaC protein without increasing the abundance of the beta and gamma subunits. Thus, alphaENaC is selectively induced by aldosterone. In addition, immunofluorescence immunolocalization showed a striking redistribution in ENaC labeling to the apical region of the collecting duct principal cells. Finally, aldosterone induced a shift in molecular weight of gammaENaC from 85 kDa to 70 kDa, consistent with physiological proteolytic clipping of the extracellular loop as postulated previously. Thus, at the protein level, the response of ENaC to aldosterone stimulation is heterogenous, with both quantitative and qualitative changes that can explain observed increases in ENaC-mediated sodium transport.

Regulation of thick ascending limb ion transporter abundance in response to altered acid/base intake

Changes in ammonium excretion with acid/base perturbations are dependent on changes in medullary ammonium accumulation mediated by active NH4+ absorption by the medullary thick ascending limb. To investigate whether alterations in the abundance of medullary thick ascending limb ion transporters, namely the apical Na+/K+(NH4+)/2Cl- -cotransporter (BSC-1), the apical Na+/H+ -exchanger (NHE3), and the Na+/K+ -ATPase alpha1-subunit, may be responsible in part for altered medullary ammonium accumulation, semiquantitative immunoblotting studies were performed using homogenates from the inner stripe of the rat renal outer medulla. After 7 d of NH4Cl (7.2 mmol/220 g body wt per d) loading (associated with increased medullary ammonium accumulation), neither BSC-1 nor Na+/K+ -ATPase protein expression was altered, but NHE3 protein abundance was significantly increased. On the other hand, both BSC-1 and Na+/K+ -ATPase protein abundance was increased significantly in rats fed NaHCO3 (7.2 mmol/220 g body wt per d) for 7 d. Rats fed a high-NaCl diet (7.7 mEq Na+/220 g body wt per d) for 5 d also showed marked increases in both BSC-1 and Na+/K+ -ATPase expression. The expression level of NHE3 protein did not change with either NaHCO3 or high NaCl intake. None of these three transporters showed a significant difference in abundance between the groups fed equimolar (7.2 mmol/220 g body wt per d for 7 d) NaHCO3 or NaCl. It is concluded that outer medullary BSC-1 and Na+/K+ -ATPase alpha1-subunit protein abundance is increased by chronic Na+ loading but not by acid/base perturbations and that outer medullary NHE3 protein abundance is increased by chronic NH4Cl loading.

Vasopressin increases Na-K-2Cl cotransporter expression in thick ascending limb of Henle's loop

To investigate whether the enhancement of thick ascending limb (TAL) NaCl transport in response to long-term increases in circulating vasopressin concentration is associated with increased expression levels of the apical Na-K-2Cl cotransporter in the rat TAL, we have carried out immunoblotting and immunofluorescence studies using affinity-purified, peptide-directed antibodies. Semiquantitative immunoblotting studies demonstrated a marked increase (193% of controls) in Na-K-2Cl cotransporter band density in response to restriction of water intake to 15 ml/day for 7 days. In contrast, the expression levels of two other apical proteins of the TAL (the type 3 Na/H exchanger and Tamm-Horsfall protein) were unchanged in the outer medulla. A 7-day subcutaneous infusion of the V2 receptor-selective vasopressin analog, 1-desamino-[8-D-arginine]vasopressin (DDAVP), to Brattleboro rats also markedly increased Na-K-2Cl cotransporter expression in the outer medulla (183% of controls). Immunofluorescence localization in outer medullary tissue sections confirmed the increase in Na-K-2Cl cotransporter expression in response to DDAVP. We conclude that vasopressin strongly upregulates the expression of the Na-K-2Cl cotransporter of the TAL and that it is likely to play an important role in the long-term regulation of the countercurrent multiplication system.

The thiazide-sensitive Na-Cl cotransporter is an aldosterone-induced protein

Although the collecting duct is regarded as the primary site at which mineralocorticoids regulate renal sodium transport in the kidney, recent evidence points to the distal convoluted tubule as a possible site of mineralocorticoid action. To investigate whether mineralocorticoids regulate the expression of the thiazide-sensitive Na-Cl cotransporter (TSC), the chief apical sodium entry pathway of distal convoluted tubule cells, we prepared an affinity-purified, peptide-directed antibody to TSC. On immunoblots, the antibody recognized a prominent 165-kDa band in membrane fractions from the renal cortex but not from the renal medulla. Immunofluorescence immunocytochemistry showed TSC labeling only in distal convoluted tubule cells. Semiquantitative immunoblotting studies demonstrated a large increase in TSC expression in the renal cortex of rats on a low-NaCl diet (207 +/- 21% of control diet). Immunofluorescence localization in tissue sections confirmed the strong increase in TSC expression. Treatment of rats for 10 days with a continuous subcutaneous infusion of aldosterone also increased TSC expression (380 +/- 58% of controls). Furthermore, 7-day treatment of rats with an orally administered mineralocorticoid, fludrocortisone, increased TSC expression (656 +/- 114% of controls). We conclude that the distal convoluted tubule is an important site of action of the mineralocorticoid aldosterone, which strongly up-regulates the expression of TSC.

Molecular and clinical characterization of Korean patients with congenital lipoid adrenal hyperplasia

Congenital lipoid adrenal hyperplasia (CLAH) is a rare autosomal recessive disorder of steroid biosynthesis, caused by a molecular defect in the steroidogenic acute regulatory protein (StAR). Patients with CLAH usually manifest severe salt wasting, hypovolemia, enlargement of the adrenal glands and complete female external genitalia irrespective of the gonadal sex. CLAH seems to be more common in Koreans and Japanese than in other ethnic populations, with a preponderance of the mutation of a glutamine to a stop codon at the 258th amino acid residue (Q258X) in the StAR gene. Clinical findings of five unrelated Korean patients with CLAH and their molecular defects in the StAR gene are described, and the gene frequency of the Q258X mutation in the Korean population is investigated. All patients developed hypovolemic shock due to severe salt wasting in the first three months after birth. All were hyperpigmented, and three of five phenotypic females were genetic males. The basal ACTH level was extremely high in all patients with the minimal concentrations of all adrenal and gonadal steroids. The Q258X mutation was identified in 9 out of 10 alleles, indicating that the genetic defect in the StAR gene of Korean patients with CLAH is highly homogeneous probably due to a founder effect. The carrier frequency of the Q258X mutation in the normal Korean population has been estimated as approximately 1 in 250 with the allele frequency of 1 in 500. However, the confidence limits of the gene frequency for the mutant allele are wide (0.5 to 8.0 among 1,000 alleles). This implies that the carrier frequency could be lower, down to 1/1,000, or higher, up to 16/1,000.

Metabolic acidosis and urinary acidification defect during the course of hemorrhagic fever with renal syndrome

To evaluate urinary acidification defect and its contribution to metabolic acidosis (MA) during hemorrhagic fever with renal syndrome (HFRS), we serially analyzed acid-base balance and urinary acidification indices in 10 HFRS patients. Data of the patients were compared with those of 8 normal volunteers (NC). MA was observed in 6 of 8 patients in the oliguric phase, 5 of 7 in the early diuretic phase, 8 of 10 in the late diuretic phase and 2 of 9 in the convalescent phase. HFRS patients with MA had a higher plasma anion gap in the oliguric and early diuretic phases than NC and a higher plasma Cl/Na ratio in the late diuretic phase than NC. As compared with acid-loaded NC, HFRS patients had a higher urine pH in the oliguric, early diuretic and late diuretic phases, a higher urine anion gap (UAG) in the oliguric and early diuretic phases and a lower urinary NH4+ excretory rate in the oliguric, early diuretic and late diuretic phases. Overt distal acidification defect was observed in 6 of 8 patients in the oliguric phase, 3 of 7 in the early diuretic phase, 5 of 10 in the late diuretic phase and none of 9 in the convalescent phase. None of the convalescent patients had latent acidification defect. In conclusion, urinary acidification defect is marked in the oliguric and diuretic phases of severe HFRS and may play a role in the development of a high anion gap (AG) metabolic acidosis in the earlier phase and hyperchloremic MA in the later phase, but rapidly recovers in the convalescent phase.

Genotoxicity study of bojungchisup-tang, an oriental herbal decoction-in vitro chromosome aberration assay in Chinese hamster lung cells and in vivo supravital-staining micronucleus assay with mouse peripheral reticulocytes

The toxicity evaluation of oriental herbal drugs is of great concern at present. Bojungchisuptang (BCST, in Korean), a decocted medicine of oriental herbal mixture, is now well used in clinic at oriental hospitals for the treatment of edema of several diseases in practice. However, the toxicity of the oriental herbal decocted medicines such as genetic toxicity is not well defined until now. In this respect, to clarify the genetic toxicity of BCST, in vitro chromosome aberration assay with Chinese hamster lung (CHL) fibroblasts and in vivo supravital micronucleus assay with mouse peripheral reticulocytes were performed in this study. In the chromosome aberration assay, we used 5,000 micrograms/ml BCST as maximum concentration because no remarkable cytotoxicity in CHL cells was observed both in the presence and absence of S-9 metabolic activation system. No statistical significant differences of chromosome aberrations were observed in CHL cells treated with 5,000, 2,500 and 1,250 micrograms/ml BCST for 6 hour both in the presence and absence of S-9 metabolic activation. However, very weak positive result (6.5-8.0% aberration) of BCST was obtained in the absence of S-9 metabolic activation system at 5,000 micrograms/ml BCST when treated for 24 hour, i.e. 1.5 normal cell cycle time. And also, in vivo clastogenicity of BCST was studied by acridine orange-supravital staining micronucleus assay using mouse peripheral reticulocytes. We used 2,000 mg/kg as the highest oral dose in this micronucleus assay because no acute oral toxicity of BCST was observed in mice. The optimum induction time of micronucleated reticulocytes (MNRETs) was determined as 36 hours after oral administration of 2,000 mg/kg BCST. No significant differences of MNRETs between control and BCST treatment groups were observed in vivo micronucleus assay. From these results, BCST revealed very weak positive result in chromosome aberration assay in vitro with CHL cells and no clastogenicity in micronucleus assay in vivo.

Absence of H(+)-ATPase in the intercalated cells of renal tissues in classic distal renal tubular acidosis

Proton-secretory defect is thought to be a major pathophysiologic mechanism leading to classic distal renal tubular acidosis (dRTA). However, there have been only two case reports demonstrating the absence of proton pump in renal tissues of the patients with Sjögren's syndrome. This study presents two cases of classic dRTA in which the absence of intact H(+)-ATPase was shown in their renal biopsy tissues by immunohistochemistry using a rabbit polyclonal antibody against the 70 kDa catalytic subunit of H(+)-ATPase from bovine brain clathrin-coated vesicles; one of the cases is diagnosed as subclinical Sjögren's syndrome and the other is idiopathic dRTA. A normal human kidney (NC) and the renal biopsy tissues from a patient with chronic tubulointerstitial nephritus whose proton secretory capacity was intact (DC) were compared as controls. The first patient, a 26-year-old woman, presented with quadriparesis. Her serologic tests revealed positive autoantibodies (ANA, SSA; SSB & RF), and a lower lip biopsy confirmed the diagnosis of Sjögren's syndrome. The second patient, a 43-year-old woman, who initially presented with a pathologic fracture of both femoral necks was referred for an evaluation for hypokalemia by the Department of Orthopedic Surgery. Her renal ultrasonography showed medullary calcification, and no autoantibodies were positive. Serum electrolytes and blood gas analyses of the two patients indicated severe hypokalemia and metabolic acidosis, and proton secretory defects were shown by a failure to lower the urine pH during marked acidemia induced by NH4Cl loading and an abnormally low urine-blood pCO2 difference during bicarbonate administration. While stainings with the anti-H(+)-ATPase antibody in NC and DC were strongly positive in intercalated cells in the connecting tubules and collecting ducts, the tissues from both patients with dRTA were devoid of any anti-H(+)-ATPase staining in the intercalated cells. These results support that the pathophysiologic basis of impaired H+ secretion in idiopathic classic dRTA as well as Sjögren's syndrome is the absence of intact H(+)-ATPase pumps in the intercalated cells.

Prenatal molecular evaluation of six fetuses in four unrelated Korean families with ornithine transcarbamylase deficiency

Ornithine transcarbamylase (OTC) deficiency, an X-linked inborn error of the urea cycle, leads to the accumulation of ammonia, causing neurologic deficits. Clinical management for the patients with OTC deficiency is frustrating and requires a burdensome medical regimen, since they may have impairment and recurrent episodes of hyperammonemia in spite of intensive care. Therefore, prenatal diagnosis of the affected fetus is important in genetic counselling for the family at high risk. In this study, mutations in the OTC gene of three obligate heterozygotes and a proband have been identified in four unrelated families: R141Q, R320X, H214Y, M205T. Each mutation altered restriction recognition sites; TaqI for R141Q, NlaIII for M205T, RsaI for H214Y, BclI for R320X. Based on their molecular defects, prenatal diagnoses of 6 fetuses including one set of fraternal twins were successfully made at the ninth to eleventh week of gestation by polymerase chain reaction (PCR)-restriction digestion using genomic DNA from chorionic villus sampling (CVS). We predicted the outcome of all fetuses prenatally. Among six, four were females and two were males, which were determined by PCR amplification of the sex determining region of the Y chromosome (SRY) gene. Each carried a wild type allele for the corresponding mutant allele. They were also tested postnatally for the mutations to be unaffected.

Observation of Q-spoiling ef fects on the resonance modes from a noncircularly deformed liquid jet

Spectral changes in fluorescence and lasing spectra were observed from a noncircularly deformed ink-doped ethanol jet, which was induced by a lateral gas flow. The distortion parameter was determined from the analysis of diffraction patterns to be as much as ~10%. Q -spoiling effects were clearly observed in the appearance of high- Q (~10(7)) modes in fluorescence and their disappearance in lasing. From the behavior of resonance modes, we concluded that the effective Q does not decrease so rapidly as predicted by the relation obtained from the ray-optics model. We also found that the signals leak out, with a wide angular spreading, mainly from near the boundary of the major axis, even for a large distortion parameter.

A comparison of the effects of testicular maturation and aging on the stage-specific expression of CP-2/cathepsin L messenger ribonucleic acid by Sertoli cells of the Brown Norway rat

We have examined the effects of maturation and aging on expression of cyclic protein-2 (CP-2)/cathepsin L mRNA by rat Sertoli cells. During maturation (25-68 days of age) there was a significant, 7.6-fold increase in CP-2/cathepsin L mRNA. There was a significant, 2.9-fold increase in SGP-2 mRNA during the same period. In situ hybridization analysis demonstrated that stage-specific expression of CP-2/cathepsin L mRNA developed between 30 and 35 days. By 64 days of age, this transcript was only detectable in Sertoli cells within stage VI-VII tubules. Northern blot analysis of 23-mo-old testes revealed statistically significant decreases in total testis contents of CP-2/cathepsin L and SGP-2 mRNAs (4- and 3-fold, respectively) in testes that lacked germ cells but not in aged testes with a full complement of germ cells. In situ hybridization analysis revealed high amounts of CP-2/cathepsin L mRNA in all aged tubules that were losing germ cells via apoptosis, regardless of the stage of the cycle. Immunocytochemical analysis demonstrated that in these aged, regressing tubules, CP-2/cathepsin L protein became concentrated in dying or dead germ cells.

Optical vortices produced with a nonspiral phase plate

We present simple methods to produce optical vortices on the axis of beam propagation with nonspiral phase plates. We show that a phase plate that provides linear phase retardation on one half of a laser beam produces optical vortices, which is demonstrated experimentally by use of a thickness-varying glass platelet. We also demonstrate and explain that mixed dislocations of a bent edge dislocation transform into a pair of vortices with opposing topological charges.

Single-particle scattering effects on the resonance modes of microdroplets

Scattering patterns captured at two different directions from ink-doped ethanol droplets containing submicrometer-sized particles, which had been pumped by nanosecond pulses, were obtained simultaneously. By use of ray optics we interpreted the various scattering patterns of the lasing in droplets. The scattering image of one side and the spectral image of the opposite side were also detected simultaneously. We observed that particles scatter with similar output couplings among modes of the same order. We also found that a single particle could react to modes of different orders with different output couplings.

Effect of Ca2+ channel blockers, external Ca2+ and phospholipase A2 inhibitors on t-butylhydroperoxide-induced lipid peroxidation and toxicity in rat liver slices

OBJECTIVES

This study was undertaken to examine the effect of oxidant on lipid peroxidation and lethal cell injury in rat liver slices.

METHODS

t-Butylhydroperoxide (t-BHP) was employed as a model of an oxidant. The lipid peroxidation and lethal cell injury were estimated by measuring the formation of malondialdehyde (MDA) and lactate dehydrogenase (LDH) release, respectively.

RESULTS

t-BHP increased lipid peroxidation and LDH release in a dose-dependent manner over concentrations of 0.5-10 mM. t-BHP-induced lipid peroxidation was completely prevented by an antioxidant, N,N-diphenyl-p-phenylenediamine (DPPD), but LDH release was partially decreased. Both t-BHP-induced lipid peroxidation and LDH release were significantly protected by iron chelator, deferoxamine, sulfhydryl reducing agent, dithiothreitol and glutathione. Ca2+ channel blockers, verapamil, diltiazem and nifedipine exerted a significant protective effect against t-BHP-induced lipid peroxidation and LDH release. By contrast, addition of external Ca2+ chelator, ethylene glycol bis(b-aminoethyl ether)-N,N-tetraacetic acid (EGTA) did not alter t-BHP-induced lipid peroxidation, whereas t-BHP-induced lethal cell injury was significantly prevented. Phospholipase A2 (PLA2) inhibitors, mepacrine and butacaine produced a partial protective effect.

CONCLUSIONS

These results suggest that t-BHP induces cell injury by lipid peroxidation-dependent and -independent mechanisms which can be partially prevented by Ca2+ channel blockers and PLA2 inhibitors.

Lasing images from two merging ink-doped liquid droplets

Lasing images from two merging ink-doped ethanol droplets (size ~37 microm), which were generated by modulation techniques and pumped by nanosecond laser pulses, were photographed through a microscope. By measuring the size difference of two adjacent droplets from the spectral shifts of lasing peaks, we confirmed that mass transfer occurred in the breakup process of the liquid jet. We observed lasing images from merging droplets in a variety of patterns. Noteworthy among these is the lasing from snowman-shaped droplets that are conjectured to stem from coupled modes with orbits around both droplets.

Simple procedure for phase identification using convergent beam electron diffraction patterns

The use of the primitive cell volume and the zero order Laue zone (ZOLZ) pattern is proposed as a means to identify phases in a complex microstructure. A single convergent beam pattern, containing a higher order Laue zone ring, from a nanosized region is sufficient to calculate the primitive cell volume of the phase, while ZOLZ pattern is used to determine the zone axis of the crystal. A computer program is used to screen out possible phases on the basis of the value of measured cell volume. The indexing of the ZOLZ pattern follows in the program to find the zone axis of the identified phase. Combination of these two methods ensures accuracy and reliability of phase identification from a single CBED pattern. An example of the analysis is given from the rapidly solidified Al-Al3Ti system.

Effect of ethylene on postharvest quality of green beans

Green beans were stored at 0,5 and 20�C in air containing ethylene at concentrations in the range 0.005-10 �L/L. The quality of individual beans was scored at regular intervals and the time for each treatment unit to deteriorate to an unacceptable quality score was calculated. Reducing the ethylene concentration in the atmosphere was found to significantly extend the storage life at all temperatures. The maximum storage life achieved at an ethylene concentration of 0.005 �L/L was 29, 20 and 11 days at 0, 5 and 20�C, respectively. For each temperature, this was about twice the storage life of beans held in 0.1-1.0 �L/L ethylene. The amount of ethylene in the atmosphere around beans held in commercial markets was found to range from 0.17 to 1.17 �L/L suggesting that the useful marketing period of beans could be greatly extended by better control over ethylene accumulation.

Evaluation of urine acidification by urine anion gap and urine osmolal gap in chronic metabolic acidosis

To investigate the clinical significance of urine anion gap and urine osmolal gap as indirect markers of urine acidification in chronic metabolic acidosis, we evaluated urine ammonium (NH4+), net acid excretion (NAE), urine anion gap (Na(+) + K(+) - Cl-), and urine osmolal gap (urine osmolality - [2(Na(+) + K(+)) + urea]) in 24 patients with chronic renal failure (CRF), eight patients with classic distal renal tubular acidosis (dRTA), and eight NH4Cl-loaded normal controls (NCs). Urine NH4+ excretion was lower (P < 0.001) in the CRF (5.4 +/- 0.6 mmol/d) and dRTA (19.2 +/- 2.7 mmol/d) patients than in the NCs (52.6 +/- 3.7 mmol/d); NAE was also lower (P < 0.001) in the CRF (9.8 +/- 1.6 mmol/d) and dRTA (16.7 +/- 4.7 mmol/d) patients than in the NCs (79.4 +/- 4.7 mmol/d). Urine anion gap was higher (P < 0.001) in the CRF (24.7 +/- 2.2 mmol/L) and dRTA (36.7 +/- 7.7 mmol/L) patients than in the NCs (-16.2 +/- 5.5 mmol/L). Urine osmolal gap was lower (P < 0.05) in the dRTA patients (129.7 +/- 17.0 mmol/L) than in the NCs (319.7 +/- 58.4 mmol/L). When the data from all subjects were pooled, urine anion gap correlated inversely with urine NH4+ (r = -0.70, P < 0.001) and with NAE (r = -0.83, P < 0.001), and urine osmolal gap correlated positively with urine NH4+ (r = 0.69, P < 0.01) and with NAE (r = 0.71, P < 0.05). We conclude that impaired urine acidification in CRF and dRTA patients is associated with an increase in urine anion gap and a decrease in urine osmolal gap, and that both urine anion gap and urine osmolal gap correlate well with NAE as well as with urine NH4+.

Identification of new mutations in the ornithine transcarbamylase (OTC) gene in Korean families

Ornithine transcarbamylase (OTC) deficiency, an X-linked inborn error of the urea cycle, is known to be heterogeneous genetically as well as phenotypically. Molecular defects of Korean patients with OTC deficiency have not been reported. To investigate molecular lesions resulting in OTC deficiency, the OTC genes of unrelated symptomatic or asymptomatic female heterozygotes were amplified exon by exon and analysed by direct sequencing of double-stranded DNA. Three new mutations, two missense and one nonsense, were detected: (1) a C-to-T transition in codon 44 in exon 2 replacing a threonine by an isoleucine (T44I) was found in a late-onset symptomatic female patient but not in her asymptomatic mother; (2) a C-to-T transition in codon 214 creating a new RsaI recognition site in exon 6 and substituting tyrosine for histidine (H214Y) was identified in an asymptomatic female carrier whose son developed acute neonatal onset of OTC deficiency; (3) a C-to-T transition in codon 320 (arginine) abolishing a TaqI recognition site and creating a new BclI site in exon 9 with generation of a stop codon (R320X) leading to premature termination in the enzyme. This nonsense mutation was found in a symptomatic female patient and her asymptomatic mother whose son died of OTC deficiency during the neonatal period. In addition, we found a G-to-A transition in codon 141 in exon 5 causing substitution of glutamine for arginine (R141Q) in a female obligate heterozygote whose previous three sons succumbed to acute neonatal-onset OTC deficiency. This missense mutation has been described previously and is known to eliminate a TaqI recognition site in exon 5.

Intracellular signal transduction of PBAN action in lepidopteran insects: inhibition of sex pheromone production by compactin, an HMG CoA reductase inhibitor

Pheromone biosynthesis activating neuropeptide (PBAN) regulates sex pheromone production in the pheromone glands of many species of female moths. In order to probe the biochemical steps as well as underlying mechanisms regulated by PBAN, we have tested the effect of chemicals on sex pheromone production by using an in vitro assay. Among the chemicals we tested here, compactin, a specific 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor, clearly inhibited the pheromone biosynthesis in the silkworm, Bombyx mori, and the common cutworm, Spodoptera litura. Since the activation of HMG CoA reductase occurs by dephosphorylation mediated by a specific phosphatase and the biochemical step regulated by PBAN in bombykol biosynthesis is similar to the one catalyzed by HMG-CoA reductase in cholesterol biosynthesis, the present results support the idea that phosphoprotein phosphatase has a significant role to regulate bombykol production in the intracellular transduction of PBAN action in B. mori.

Intracellular transduction in the regulation of pheromone biosynthesis of the silkworm, Bombyx mori: suggested involvement of calmodulin and phosphoprotein phosphatase

We have tested the effects of chemicals on bombykol production in vitro in the silkworm, Bombyx mori, to probe the biochemical steps as well as underlying mechanisms regulated by PBAN. These results suggest the involvement of calmodulin and phosphoprotein phosphatase in the intracellular signal transduction of PBAN action.

Efficient radially polarized laser beam generation with a double interferometer

Conversion of a linearly polarized CO(2) laser beam into a radially polarized beam is demonstrated with a novel double-interferometer system. The first Mach-Zehnder interferometer converts the linearly polarized input beam into two beams with sin(2) θ and cos(2) θ intensity profiles, where θ is the azimuthal angle. This is accomplished by using two spiral-phase-delay plates with opposite handedness in the two legs of the interferometer to impart a one-wave phase delay azimuthally across the face of the beams. After these beams are interfered with, the resulting beams are sent directly into the second Mach-Zehnder interferometer, where the polarization direction of one beam is rotated by 90°. The beams are then recombined at the output of the second interferometer with a polarization-sensitive beam splitter to generate a radially polarized beam. The output beam is ≈92% radially polarized and contains ≈85% of the input power. This system will be used in upcoming laser particle acceleration experiments.

Intestinal neurofibromatosis in von Recklinghausen's disease: presenting as chronic anemia due to recurrent intestinal hemorrhage

Neurofibromatosis (von Recklinghausen's disease) is a neuroectodermal disorder characterized by pigmentary changes of the skin (café-au-lait spots), cutaneous and visceral tumors (neurofibromas) and systemic abnormalities. The involvement of gastrointestinal tract in neurofibromatosis is not common. The most common symptoms, refer able to lesions in the gut, are hematemesis, melena and abdominal pain. We experienced a case of intestinal neurofibroma in von Recklinghausen's disease. The patient was a 39 year-old female who had suffered from chronic iron deficiency anemia and recurrent gastrointestinal hemorrhage due to two neurofibromas of jejunum for 3 years, which was diagnosed by superior mesenteric and ileal arteriogram and 99mTc pertechnetate-labelled RBC scan, and treated by segmental resection of jejunum with end to end anastomosis.

Reduction of the blocking effect in block-coded images using a model of early human vision

We propose a method, based on lowpass and bandpass components of Granrath's early human vision model, which reduces the blocking effect in block-coded images. The method consists of a lowpass filtering stage to smooth out the blocking effect and a contrast-enhancement stage to increase contrast in the restored image. Experimental results of the method show better performance than that of conventional methods for reducing blocking effects.