Sperm count in Swedish clinical stage I testicular cancer patients following adjuvant treatment

BACKGROUND

Little is known regarding sperm production following adjuvant treatment in testicular cancer (TC) clinical stage I (CS I) patients.

PATIENTS AND METHODS

A total of 182 TC patients aged 18-50 years were prospectively included during 2001-2006 at any given time within 5 years of orchiectomy. Semen samples were delivered postorchiectomy but before further treatment, 6, 12, 24, 36 and 60 months (T0-T60) after completed therapy. Total sperm number (TSN) and sperm concentration (SC) were used as measurements of testicular function. Four groups according to treatment modality were identified; Radiotherapy; To a total dose of 25.2 Gy to the infradiaphragmal paraaortic and ipsilateral iliac lymph nodes (RT, N = 70), one cycle of adjuvant BEP (bleomycin, etoposide, cisplatin, 5 day regimen) (BEP, N = 62), one cycle of adjuvant carboplatin AUC 7 (Carbo, N = 22), and patients managed by surveillance (SURV, N = 28).

RESULTS

In the cross-sectional analysis, a significant but transient drop in mean TSN and mean SC (T0-T60) was seen at T6 after radiotherapy. Apart from a significant increase in mean SC at T12 compared with baseline, no significant differences were observed in the other treatment groups. In 119 patients delivering 3 or more samples, values in TSN and SC were rather stable over time. Azoospermic patients (N = 11) were observed in most treatment groups except for in the BEP group. During follow-up, one azoospermic patient belonging to the Carbo group became normospermic.

CONCLUSIONS

No clinically significant long-term effect on TSN or SC associated with adjuvant treatment in TC CSI patients was found. However, as patients may have low sperm counts before orchiectomy as well as after adjuvant treatment, we offer sperm banking before orchiectomy as assisted reproductive measures may be necessary regardless of treatment given.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Tryptophan Metabolism Along the Kynurenine Pathway Downstream of Toll-like Receptor Stimulation in Peripheral Monocytes

Tryptophan degradation along the kynurenine pathway is of central importance for the immune function. Toll-like receptors (TLRs), representing the first line of immune defence against pathogens, are expressed in various cell types. The most abundant expression is found on monocytes, macrophages and dendritic cells. The aim of this study was to investigate whether stimulation with different TLR ligands induces the kynurenine pathway in human peripheral monocytes. Cell supernatants were analysed using a liquid chromatography/mass spectrometry to measure kynurenine, kynurenic acid (KYNA), quinolinic acid (QUIN) and tryptophan. Stimulation of TLR-2, TLR-3, TLR-4, TLR-7/8 and TLR-9 was found to induce the production of kynurenine, but only stimulation of TLR-3 increased levels of further downstream metabolites, such as KYNA and QUIN. Stimulation of TLR-1, TLR-5 and TLR-6 did not induce the kynurenine pathway. Taken together, this study provides novel evidence demonstrating that TLR activation induces a pattern of downstream tryptophan degradation along the kynurenine pathway in monocytes. The results of this study may implicate that TLRs can be used as new drug targets for the regulation of aberrant tryptophan metabolism along this pathway, a potential therapeutic strategy that may be of importance in several disorders.

Repeated LPS Injection Induces Distinct Changes in the Kynurenine Pathway in Mice

The immune system has been recognized as a potential contributor to psychiatric disorders. In animals, lipopolysaccharide (LPS) is used to induce inflammation and behaviors analogous to some of the symptoms in these disorders. Recent data indicate that the kynurenine pathway contributes to LPS-induced aberrant behaviors. However, data are inconclusive regarding optimal LPS dose and treatment strategy. Here, we therefore aimed to evaluate the effects of single versus repeated administration of LPS on the kynurenine pathway. Adult C57BL6 mice were given 0.83 mg/kg LPS as a single or a repeated injection (LPS + LPS) and sacrificed after 24, 48, 72, or 120 h. Mice receiving LPS + LPS had significantly elevated brain kynurenine levels at 24 and 48 h, and elevated serum kynurenine at 24, 48 and 72 h. Brain kynurenic acid and quinolinic acid were significantly increased at 24 and 48 h in mice receiving LPS + LPS, whereas serum kynurenic acid levels were significantly decreased at 24 h. The increase of brain kynurenic acid by LPS + LPS was likely unrelated to the higher total dose as a separate group of mice receiving 1.66 mg/kg LPS as single injection 24 h prior to sacrifice did not show increased brain kynurenic acid. Serum quinolinic acid levels were not affected by LPS + LPS compared to vehicle. Animals given repeated injections of LPS showed a more robust induction of the kynurenine pathway in contrast to animals receiving a single injection. These results may be valuable in light of data showing the importance of the kynurenine pathway in psychiatric disorders.

Reduction of plasma aldosterone and arterial stiffness in obese pre- and stage1 hypertensive subjects after aerobic exercise

Obesity-related hypertension is associated with increased activity of the renin-angiotensin-aldosterone system (RAAS), increasing arterial stiffness. Aerobic exercise decreases pulse wave velocity (PWV), therefore a treatment option for hypertension and obesity. Assess RAAS activity and PWV before and after 4 weeks of aerobic training in unmedicated, pre-to-stage-1 hypertensives. Ten obese subjects (52±3.2 years, body mass index=33.5±1.4) performed 30 min of aerobic exercise on a treadmill 3 days per week at 65% of peak oxygen consumption (VO2peak). Descriptive characteristics, systolic and diastolic blood pressure (SBP and DBP), PWV, and a blood draw was performed at baseline, following the 4-week control and training interventions. No differences in descriptive characteristics during the control period were observed, however, a significant decrease in plasma aldosterone (ALDO) (255.4±75 to 215.8±66 pg ml(-1), P=0.001), SBP (140±12 to 136±10.4 mm Hg; P=0.02), DBP (89±4.2 to 85±6.3 mm Hg; P=0.03) and central PWV (11.2±0.6 to 9.8±0.8 m s(-1); P=0.04) was shown pre-to-post exercise training. Four weeks of moderate-intensity aerobic training in obese, hypertensives decreases plasma ALDO independently of body weight and is significantly correlated to decreases in PWV reductions.

Close linkage between the albumin and Gc loci in the horse

Evidence for close linkage between the structural loci for albumin and Gc protein in the horse was presented. A recombination frequency (c) of 0.009 +/- 0.006 (95% confidence limits: 0.001 less than c less than 0.032) was estimated. These results were based on a study of a large sire family comprising 223 offspring from informative matings. No evidence of linkage disequilibrium was observed in one horse population studied.

Genetic polymorphism and close linkage of two alpha 1-protease inhibitors in horse serum

Two-dimensional electrophoretic analysis of horse serum proteins was done by a first-dimension separation in agarose gel (pH 5.4) followed by a second-dimension separation in horizontal polyacrylamide gel (pH 9.0). This method resulted in improved and reproducible separation of many alpha-globulins. Two groups of alpha 1-globulins, designated Pi1 and Pi2, were found to be protease inhibitors. Preliminary studies indicated that Pi1 and Pi2 proteins differed from each other in molecular weight and in protease inhibiting spectra. Extensive polymorphism was observed for both these proteins. Family data supported the hypothesis that Pi1 and Pi2 types were controlled by autosomal codominant alleles. For both Pi1 and Pi2 systems, most of the homozygous types showed two fractions each while the heterozygous types had 4 fractions. Six Pi1 and five Pi2 alleles were observed in two breeds of Swedish horses. Complete genetic linkage was observed for Pi1 and Pi2 loci as no recombinant type was observed in 40 informative matings studied.

Genetic linkage between the loci for phosphohexose isomerase (PHI) and a serum protein (Xk) in horses

Genetic linkage between the equine loci for phosphohexose isomerase (PHI) and serum Xk protein was demonstrated by means of segregation data from three sire families. The recombination frequency was estimated from pooled data to be 0.23 +/- 0.02; a significant heterogeneity between sires for estimates of the recombination frequency was observed. No indication of linkage was detected between Xk and 14 other blood marker loci. Linkage between the Xk locus and the locus for soluble malic enzyme (ME1) has recently been reported in horses. An equine linkage group designated LG IV comprising the three loci ME1, PHI, and Xk has thus been established. The possibility that the linkage between PHI and Xk is homologous to the linkage between the loci for PHI and a serum postalbumin (PO-2) in pigs was discussed.

Two-dimensional electrophoresis of horse serum proteins: genetic polymorphism of ceruloplasmin and two other serum proteins

Two-dimensional agarose gel (pH 8.6)-horizontal polyacrylamide gel (pH 9.0) electrophoresis of horse serum proteins revealed genetic polymorphism of ceruloplasmin (Cp) and two unidentified serum proteins tentatively designated serum protein 1 (SP1) and serum protein 2 (SP2). Family data were consistent with the hypothesis that the observed Cp and SP1 phenotypes were each controlled by two codominant, autosomal alleles. The three common SP2 phenotypes were shown to be controlled by two codominant, autosomal alleles. Population data and limited family data indicated the occurrence of two additional SP2 alleles. Altogether more than 600 horses representing 13 different breeds were typed for Cp, SP1 and SP2, and allele frequency estimates were calculated. SP2 was highly polymorphic in all breeds studied whereas SP1 and Cp showed quite low degrees of polymorphism. SP1 polymorphism was observed in seven breeds while Cp polymorphism was observed only in the Icelandic toelter horse breed.

Genetic polymorphism of horse serum protein 3 (SP3)

Two-dimensional agarose gel (pH 8.6)-horizontal polyacrylamide gel (pH 9.0) electrophoresis of horse serum samples, followed by general protein staining, revealed genetic polymorphism of an unidentified protein tentatively designated serum protein 3 (SP3). The SP3 fractions appeared distinctly when a 14% concentration of acrylamide was used in the separation gels. The 2-D mobilities of SP3 fractions were quite similar to that of albumin. Family data were consistent with the hypothesis that the observed SP3 phenotypes were controlled by four co-dominant, autosomal alleles (D, F, I, S). Evidence was provided that the F allele can be further divided into two alleles (F1 and F2); the mobilities of F1 and F2 variants were very similar. Each of the SP3 alleles gave rise to one fraction and each of the heterozygous types showed two fractions. More than 600 horses representing five different breeds (Swedish Trotter, North-Swedish Trotter, Thoroughbred, Arab and Polish Tarpan) were typed for SP3, and allele frequency estimates were calculated. SP3 was highly polymorphic in all breeds studied.

Genetic polymorphism of the vitamin D binding protein and another post-albumin protein in horse serum

Horizontal polyacrylamide gel electrophoreses, on 10% separation gel, of horse serum revealed polymorphism of the vitamin D binding protein (Gc protein) and another post-albumin protein (Pa). Family data supported the hypothesis that Gc and Pa types were controlled by autosomal codominant alleles. For both Gc and Pa proteins, the homozygous types showed a single fraction while the heterozygous type had two fractions. Pa types were found to be identical to the post-albumin types reported earlier by starch gel electrophoresis. Two Gc alleles, GcF and GcS, and three Pa alleles, Pa D, Pa F and Pa S, were observed in samples from Swedish (four breeds), Lipizzaner and Arab horses. The frequency of the more common allele at the two loci, i.e. GcF and PaF, ranged from 0.72-0.93 and from 0.58-0.99, respectively, in the different breeds studied. Plasma samples showed an extra protein fraction near the GcS fraction and thus were found unsuitable for Gc typing.

Association between serum esterase (Es) type and starting proportion in Swedish Trotters: further observations

A study was carried out to attempt to explain the basis of the association between the Es locus and starting proportion in Swedish Trotters which had been observed previously. The effect of Es genotype on starting proportion has diminished among horses born in the late 1970s. There are indications that the incidence of leg lesions varies between Es genotypes. If this is true, it is possible that the decreasing effect of the Es locus on starting proportion is due to the environmental changes which have been made at race tracks in the early 1980s to reduce the strain on the legs of the trotters.

Cloning of highly polymorphic microsatellites in the horse

We have isolated equine microsatellites by screening a genomic library with (TG)n and (TC)n probes. TG microsatellites were found to be more abundant than TC repeats, with an estimated frequency of one per 100,000bp. Sequence analysis of eight TG-positive clones revealed varying structures of the repeat regions; perfect stretches of TG repeats, imperfect stretches of TG repeats and compound regions of TG and TC repeats. Five loci were analysed by PCR and showed extensive polymorphism; three to seven alleles and heterozygosities of 0.40-0.76 were observed when screening 20-30 unrelated individuals. The high degree of polymorphism, their abundance and the possibility of automating the typing procedure make these loci ideal for standardized paternity testing in the horse. Furthermore, we demonstrate that single hairs can be used as starting material for the PCR analysis.

Comparative linkage mapping of the Grey coat colour gene in horses

Grey horses are born coloured, turn progressively grey and often develop melanomas late in life. Grey shows an autosomal dominant inheritance and the locus has previously been mapped to horse chromosome 25 (ECA25), around the TXN gene. We have now developed eight new single nucleotide polymorphisms (SNPs) associated with genes on ECA25 using information on the linear order of genes on human chromosome 9q, as well as the human and mouse coding sequences. These SNPs were mapped in relation to the Grey locus using more than 300 progeny from matings between two Swedish Warmblood grey stallions and non-grey mares. Grey was firmly assigned to an interval with flanking markers NANS and ABCA1. This corresponds to a region of approximately 6.9 Mb on human chromosome 9q. Furthermore, no recombination was observed between Grey, TGFBR1 and TMEFF1, the last two being 1.4 Mb apart in human. There are no obvious candidate genes in this region and none of the genes has been associated with pigmentation disorders or melanoma development, suggesting that the grey phenotype is caused by a mutation in a novel gene.

Regulation of pituitary corticotropin releasing factor type-1 receptor mRNA binding proteins by modulation of the hypothalamic-pituitary-adrenal axis

Long-term adrenalectomy (ADX) is associated with marked down-regulation of pituitary corticotropin releasing factor type-1 receptors (CRF-R1) but normal CRF-R1 mRNA levels, suggesting that regulation of receptor levels occurs at post-transcriptional sites. We have reported that adrenal cytosolic proteins, which bind to cis elements in the 5' leader sequence (5'LS) of the rat angiotensin II type 1a receptor (AT(1a)R) mRNA, participate in the regulation of AT(1a)R density by inhibiting AT(1a)R mRNA translation. In this study, we examined anterior pituitary cytosolic proteins that form RNA protein complexes (RPC) with the 5'LS of the CRF-R1 and the AT(1a)R. Competition studies and ultraviolet-crosslinking analysis suggest that formation of CRF-R1 and AT(1a)R 5'LS RPC require at least some proteins that are common to both receptor mRNAs. Pituitaries isolated from male Sprague-Dawley rats six days after ADX showed significant (P < 0.05) increases of 2.9-fold in CRF-R1 5'LS RNA binding protein (BP) activity compared to pituitaries from sham-operated rats; this effect of ADX was prevented by glucocorticoid replacement. By contrast, no differences in the number of pituitary AT(1a)R binding sites or pituitary AT(1a)R 5'LS BP activity were observed between sham and ADX rats, indicating that the effect of ADX on RPC formation was specific for CRF-R1 mRNA. Addition of pituitary cytosolic extracts inhibited in vitro translation of CRF-R1 mRNA by 79% under conditions that had no significant effects on the translation of a control mRNA. The data suggest that CRF-R1 translation is regulated by modulation of the HPA axis through pituitary cytosolic proteins binding to the CRF-R1 5'LS.

Molecular characterization and mutational screening of the PRKAG3 gene in the horse

The PRKAG3 gene encodes a muscle-specific isoform of the regulatory gamma subunit of AMP-activated protein kinase (AMPK). A major part of the coding PRKAG3 sequence was isolated from horse muscle cDNA using reverse-transcriptase (RT)-PCR analysis. Horse-specific primers were used to amplify genomic fragments containing 12 exons. Comparative sequence analysis of horse, pig, mouse, human, Fugu, and zebrafish was performed to establish the exon/intron organization of horse PRKAG3 and to study the homology among different isoforms of AMPK gamma genes in vertebrates. The results showed conclusively that the three different isoforms (gamma1, gamma2, and gamma3) were established already in bony fishes. Seven single nucleotide polymorphisms (SNPs), five causing amino acid substitutions, were identified in a screening across horse breeds with widely different phenotypes as regards muscle development and intended performance. The screening of a major part of the PRKAG3 coding sequence in a small case/control material of horses affected with polysaccharide storage myopathy did not reveal any mutation that was exclusively associated with this muscle storage disease. The breed comparison revealed several potentially interesting SNPs. One of these (Pro258Leu) occurs at a residue that is highly conserved among AMPK gamma genes. In an SNP screening, the variant allele was only found in horse breeds that can be classified as heavy (Belgian) or moderately heavy (North Swedish Trotter, Fjord, and Swedish Warmblood) but not in light horse breeds selected for speed or racing performance (Standardbred, Thoroughbred, and Quarter horse) or in ponies (Icelandic horses and Shetland pony). The results will facilitate future studies of the possible functional significance of PRKAG3 polymorphisms in horses.

The second generation of the International Equine Gene Mapping Workshop half-sibling linkage map

A low-density, male-based linkage map was constructed as one of the objectives of the International Equine Gene Mapping Workshop. Here we report the second generation map based on testing 503 half-sibling offspring from 13 sire families for 344 informative markers using the CRIMAP program. The multipoint linkage analysis localized 310 markers (90%) with 257 markers being linearly ordered. The map included 34 linkage groups representing all 31 autosomes and spanning 2262 cM with an average interval between loci of 10.1 cM. This map is a milestone in that it is the first map with linkage groups assigned to each of the 31 automosomes and a single linkage group to all but three chromosomes.

Combined angiotensin converting enzyme inhibition and angiotensin AT(1) receptor blockade up-regulates myocardial AT(2) receptors in remodeled myocardium post-infarction

OBJECTIVES

In an ovine model of left ventricular (LV) remodeling after transmural anteroapical myocardial infarction (MI), we have previously demonstrated that the combination of angiotensin converting enzyme (ACE) inhibition and AT(1) receptor blockade is more effective at limiting LV remodeling than either therapy alone. We hypothesized that the beneficial effect of combined therapy is due in part to upregulation of AT(2) receptor levels.

METHODS

Two days after transmural anteroapical MI by coronary ligation, 16 sheep were randomized to losartan (50 mg/day), ramipril (10 mg/day), ramipril+losartan (combined therapy), or no therapy. At 8 weeks after MI, radioligand receptor assay were deployed with homogenates from regional LV tissues.

RESULTS

We found that AT receptors in normal sheep myocardium are predominantly of the AT(2) receptor subtype. Binding studies of remodeled myocardium 8 weeks later showed that the apparent maximum binding (B(max)) was increased from 23 to 48 fmol/mg protein only in animals with combined therapy. The AT(2)/AT(1) proportion was increased significantly in animals with combined therapy compared to infarcted controls (18.0 vs. 5.17).

CONCLUSIONS

These results indicate that AT(2) receptor expression increased significantly during LV remodeling with combined therapy but not with either therapy alone. In combination with prior work demonstrating the effectiveness of combined therapy in limiting LV remodeling, this study is consistent with the hypothesis that AT(2) receptors play a cardioprotective role in LV remodeling after MI.

Mapping of 13 horse genes by fluorescence in-situ hybridization (FISH) and somatic cell hybrid analysis

We report fluorescence in-situ hybridization (FISH) and somatic cell hybrid mapping data for 13 different horse genes (ANP, CD2, CLU, CRISP3, CYP17, FGG, IL1RN, IL10, MMP13, PRM1, PTGS2, TNFA and TP53). Primers for PCR amplification of intronic or untranslated regions were designed from horse-specific DNA or mRNA sequences in GenBank. Two different horse bacterial artificial chromosome (BAC) libraries were screened with PCR for clones containing these 13 Type I loci, nine of which were found in the libraries. BAC clones were used as probes in dual colour FISH to confirm their precise chromosomal origin. The remaining four genes were mapped in a somatic cell hybrid panel. All chromosomal assignments except one were in agreement with human-horse ZOO-FISH data and revealed new and more detailed information on the equine comparative map. CLU was mapped by synteny to ECA2 while human-horse ZOO-FISH data predicted that CLU would be located on ECA9. The assignment of IL1RN permitted analysis of gene order conservation between HSA2 and ECA15, which identified that an event of inversion had occurred during the evolution of these two homologous chromosomes.

Coordinate regulation of canine glomeruli and adrenal angiotensin receptors by dietary sodium manipulation

BACKGROUND

This study evaluated the effects of dietary sodium manipulation in dogs on the regulation of canine angiotensin receptors (cAT1 and cAT2) in the kidney and adrenal.

METHODS

Isolated glomeruli and membranes from renal medulla and the adrenal gland were used in radioligand binding assays from two groups of dogs: dogs maintained on low-sodium diet for two weeks followed by a high-sodium diet for two weeks (H), and dogs were maintained on the reverse schedule (L).

RESULTS

Analysis of the binding data showed that dietary sodium manipulation had no significant effects on cAT1 and cAT2 receptor binding affinities in glomeruli, renal medulla, and adrenal tissues. In contrast, dietary sodium loading induced a marked increase in cAT1 receptor expression in both the glomeruli and adrenal compared with receptor expression in salt-restricted animals [H/L ratio: glomeruli (1.5), renal medulla (1.1), adrenal (1.6)] that inversely correlated with the activity of the plasma renin angiotensin system. Conversely, adrenal cAT2 receptor expression was regulated in an inverse manner in the H and L animal groups [H/L ratio: 0.7].

CONCLUSIONS

This study demonstrates that renal glomerular and adrenal AT1 receptors in the dog are coordinately down-regulated by dietary sodium restriction compared with sodium loading, which is distinctly different from the reciprocal regulation observed for rat AT1 receptors in these tissues. Collectively, these data suggest that postreceptor events in dogs are determinants of the aldosterone response observed during sodium restriction. These findings have important implications for the regulation of the renin-angiotensin system in humans, and suggest that coordinate regulation of AT1 receptors in the adrenal and glomeruli represent a negative feedback mechanism that when functioning normally prevents fluctuations of arterial blood pressure and development of arterial hypertension in response to changes in dietary sodium.

Physical anchorage and orientation of equine linkage groups by FISH mapping BAC clones containing microsatellite markers

A horse bacterial artificial chromosome (BAC) library was screened for 19 microsatellite markers from unassigned or non-oriented linkage groups. Clones containing 11 (AHT20, EB2E8, HMS45, LEX005, LEX014, LEX023, LEX044, TKY111, UCDEQ425, UCDEQ464 and VIASH21) of these were found, which were from eight different linkage groups. The BAC clones were used as probes in dual colour FISH to identify their precise chromosomal origin. The microsatellite markers are located on nine different horse chromosomes, four of which (ECA6, ECA25, ECA27 and ECA28) had no previously in situ assigned markers.

Widespread origins of domestic horse lineages

Domestication entails control of wild species and is generally regarded as a complex process confined to a restricted area and culture. Previous DNA sequence analyses of several domestic species have suggested only a limited number of origination events. We analyzed mitochondrial DNA (mtDNA) control region sequences of 191 domestic horses and found a high diversity of matrilines. Sequence analysis of equids from archaeological sites and late Pleistocene deposits showed that this diversity was not due to an accelerated mutation rate or an ancient domestication event. Consequently, high mtDNA sequence diversity of horses implies an unprecedented and widespread integration of matrilines and an extensive utilization and taming of wild horses. However, genetic variation at nuclear markers is partitioned among horse breeds and may reflect sex-biased dispersal and breeding.

Analysis of Cytosolic Proteins that Bind to the 5' Leader Sequence of the Angiotensin AT1 Receptor by RNA Electromobility Shift Assay

Electromobility shift assays (EMSAs) provide a way to study proteinnucleic acid interactions. This method is based on the observation that the electrophoretic mobility of nucleic acids through polyacrylamide gels is retarded when bound to proteins. The mobility of nucleic acid-protein complexes are thus "shifted" with respect to the free nucleic acids. Typically, the nucleic acids are labeled with (32)P. Once the nucleic acid-protein complexes are separated from free radiolabeled nucleic acids, the electrophoresis is terminated and the gel dried. The radiolabeled nucleic acids in their free and complexed forms are visualized and quantified by phosphor autoradiography or by X-ray autoradiography. DNA-binding proteins are commonly identified by EMSA. EMSA also works well for studying purified RNA-binding proteins (1-3) and this technique is currently being developed for identifying unknown RNA-binding proteins.

Comparative analysis of amphibian and mammalian angiotensin receptors

Amphibian angiotensin receptors (xAT receptors) share many similarities with mammalian type 1 angiotensin receptors (AT(1) receptors). Both xAT and AT(1) receptors belong to the super family of seven transmembrane spanning G protein-coupled receptors and share approximately 60% amino acid homology. Highly stable secondary structure in the 5' leader sequences and the presence of the mRNA destabilizing sequence (AUUUA) in the 3' untranslated region (3'UTR) of the xAT and AT(1) receptor mRNAs suggest similar mechanisms exist for regulating gene expression. Amphibian and mammalian AT receptors bind angiotensin with equivalent affinities but show marked differences in their affinities towards mammalian AT(1) receptor subtype selective non-peptide ligands. Both xAT and AT(1) receptors couple to G proteins and to the phospholipase C (PLC) signal transduction pathway. Mammalian AT(1) receptors play a key role in maintaining blood pressure and fluid homeostasis and there is considerable evidence that xAT receptors play a similarly important role in amphibians. This review focuses on the comparison of amphibian xAT receptors with mammalian AT(1) receptors in terms of their structure, pharmacology, signaling, and function.

Estradiol attenuates angiotensin-induced aldosterone secretion in ovariectomized rats

Estrogen replacement therapy significantly reduces the risk of cardiovascular disease in postmenopausal women. Previous studies indicate that estradiol (E2) decreases angiotensin II (AT) receptor density in the adrenal and pituitary in NaCl-loaded rats. We used an in vivo model that eliminates the potentially confounding influence of ACTH to determine whether the E2-induced decrease in adrenal AT receptor expression affects aldosterone responses to angiotensin II (Ang II). Female rats were ovariectomized, treated with oil (OVX) or E2 (OVX+E2; 10 microg, s.c.) for 14 days, and fed a NaCl-deficient diet for the last 7 days to maximize adrenal AT receptor expression and responsiveness. On days 12-14 rats were treated with dexamethasone (DEX; 25 microg, i.p., every 12 h) to suppress plasma ACTH. On day 14 aldosterone secretion was measured after a 30-min infusion of Ang II (330 ng/min). Ang II infusion increased the peak plasma aldosterone levels to a lesser degree in the OVX+E2 than in the OVX rats (OVX, 1870 +/- 290 pg/ml; OVX+E2, 1010 +/- 86 pg/ml; P < 0.05). Ang II-induced ACTH and aldosterone secretion was also studied in rats that were not treated with DEX. In the absence of DEX, the peak plasma aldosterone response was also significantly decreased (OVX, 5360 +/- 1200 pg/ml; OVX+E2, 2960 +/- 570 pg/ml; P < 0.05). However, E2 also reduced the plasma ACTH response to Ang II (P < 0.05; OVX, 220 +/- 29 pg/ml; OVX+E2, 160 +/- 20 pg/ml), suggesting that reduced pituitary ACTH responsiveness to Ang II contributes to the effect of E2 on Ang II-induced aldosterone secretion. Adrenal AT1 binding studies confirmed that E2 significantly reduces adrenal AT1 receptor expression in both the presence and absence of DEX in NaCl-deprived rats. These results indicate that E2-induced decreases in pituitary and adrenal AT1 receptor expression are associated with attenuated pituitary ACTH and adrenal aldosterone responses to Ang II and suggest that estrogen replacement therapy may modulate Ang II-stimulated aldosterone secretion as part of its well known cardioprotective actions.

Preterm infants with low immunoglobulin G levels have increased risk of neonatal sepsis but do not benefit from prophylactic immunoglobulin G

OBJECTIVE

In a prospective, randomized, placebo-controlled, multicenter study, we evaluated the prevention of neonatal infections with intravenous immunoglobulin G (IVIgG) prophylaxis for preterm infants (gestational age <33 weeks) with umbilical cord blood IgG levels < or =4 g/L.

STUDY DESIGN

Intravenous IgG or placebo (albumin), 1 g/kg body weight, was given on days 0, 3, 7, 14, and 21 to 81 infants with umbilical cord blood IgG levels < or =4 g/L: (1) IVIgG group, n = 40, mean (SD) gestational age 27.5 (2.2) weeks and birth weight 1.06 (0.39) kg; (2) placebo group, n = 41, mean (SD) gestational age 27.7 (2.5) weeks and birth weight 1.13 (0.38) kg. Infants with umbilical cord blood IgG levels >4 g/L (n = 238) served as a separate comparison group. Neonatal infections according to European Society of Pediatric Infectious Disease criteria were monitored until 28 days of life.

RESULTS

Infants with IgG levels < or =4 g/L at birth who received IVIgG had no significant reduction in infectious episodes or mortality rate when compared with those given placebo. However, infants with a serum concentration of IgG >4 g/L at birth had significantly fewer infectious episodes (culture-proven sepsis) than infants with low serum concentrations of IgG (< or =4 g/L) when compared at the same gestational ages (26 to 29 weeks, P <.003).

CONCLUSIONS

Prophylactic immunotherapy with IVIgG did not improve the immune competence in preterm infants with low serum IgG concentrations at birth. We speculate that a spontaneously high serum IgG concentration at birth reflects placenta function and is an indicator of a more mature immune system capable of protecting the preterm infant against severe neonatal infections.

Kidney angiotensin receptors and their role in renal pathophysiology

A considerable amount of data have implicated angiotensin receptors (AT receptors) in the development and maintenance of essential hypertension and renovascular hypertension as well as in progressive renal pathologies. Inhibition of angiotensin II (Ang II) action by blocking Ang II formation through angiotensin-converting enzyme (ACE) inhibitors, or by blocking AT1 receptors directly using subtype-selective nonpeptide antagonists, has been found to attenuate the proteinuria, microalbuminuria, glomerulosclerosis, and nephrosclerosis in a variety of experimental models and in clinical trials. This review will first broadly discuss AT receptor subtypes in terms of their structure, function, tissue distribution and signaling. Secondly, the mechanistic differences between ACE inhibition and AT1 receptor blockade will be examined because these pharmaceutical agents are widely used tools to investigate the role of AT receptors in renal disease. Lastly, experimental models of essential hypertension, renovascular hypertension and progressive renal disease will be presented, which include the Fawn-hooded rat, the stroke prone spontaneously hypertensive rat, renal mass ablation and the 2K1C and 1K1C animal models. The overall goal of this review is to critically evaluate the data regarding the role of AT receptors in the pathophysiology of renal disease.

Rat model for investigating ACTH-independent angiotensin-induced aldosterone secretion

Study of the acute effects of angiotensin II (Ang II) on aldosterone secretion has been hindered by the confounding influence of Ang II-induced adrenocorticotropic hormone (ACTH) secretion on aldosterone secretion, and by the fact that when laboratory rats are fed standard laboratory chows that are high in sodium, the adrenal is only minimally responsive to Ang II. In this study, we report the development of a model of Ang II-induced aldosterone secretion in NaCl-deprived, dexamethasone (DEX)-treated rats. This model allows the observation of (a) a high magnitude of Ang II-induced aldosterone secretion, (b) a return of plasma aldosterone levels to baseline after stimulation, and (c) aldosterone secretion without the potentially confounding influence of ACTH stimulation.

Vasopressin V2 receptor binding is down-regulated during renal escape from vasopressin-induced antidiuresis

This study evaluated whether renal escape from vasopressin-induced antidiuresis is associated with alterations of vasopressin V2 receptor binding in the kidney inner medulla. A radioligand binding assay was developed using a novel iodinated vasopressin V2 receptor antagonist to analyze vasopressin V2 receptor binding in kidney inner medullary tissue from three groups of rats: normal rats maintained on ad libitum water intake, rats treated with 1-deamino-[8-D-arginine]vasopressin (DDAVP), and rats treated with DDAVP that were also water loaded to induce renal escape from antidiuresis. Analysis of the binding data showed that DDAVP treatment reduced vasopressin V2 receptor binding to 72% of normal levels. Water loading induced a marked further down-regulation of vasopressin V2 receptor binding. This receptor down-regulation began by day 2 of water loading, which correlated with the initiation of renal vasopressin escape; by day 3 of water loading, vasopressin V2 receptor expression fell to 43% of DDAVP-treated levels. No differences in vasopressin V2 receptor binding affinities were found among the three groups. This study demonstrates that vasopressin V2 receptor binding capacity is down-regulated during renal escape from vasopressin-induced antidiuresis and suggests that both vasopressin-dependent mechanisms as well as vasopressin-independent mechanisms associated with water loading are involved in this receptor down-regulation.

The voiding pattern of healthy preterm neonates

PURPOSE

To elucidate further the maturation of voiding habits from gestation to infancy we investigated the free voiding pattern of healthy preterm neonates.

MATERIALS AND METHODS

We evaluated 11 male and 8 female healthy preterm newborns at a mean of 32 weeks after cessation of menstrual flow (postmenstrual age). Assessment was done in the neonatal ward using 4-hour voiding observation, a method described previously in studies of free voiding pattern of full-term newborns.

RESULTS

The voiding pattern of male and female preterm neonates was characterized by 1 void per hour and a mean voided volume of 53% of bladder capacity with 58% frequency of interrupted voiding. Residual urine was increased but varied during observation (mean 11% bladder capacity) and was 0 after at least 1 void during 4 hours in 14 of the 19 subjects. Two-thirds of all voiding occurred during sleep, whereas a third of the newborns showed signs of arousal with a mean awake time of only 17 minutes.

CONCLUSIONS

The voiding pattern of preterm versus full-term subjects is characterized by an increased number of interrupted voidings, further indicating that these voidings represent immature behavior of detrusor-sphincter coordination. Also, the high number of voidings during sleep suggest a more immature pattern for preterm newborns.

Estrogen regulates angiotensin AT1 receptor expression via cytosolic proteins that bind to the 5' leader sequence of the receptor mRNA

Two of the most highly recognized factors implicated in the pathogenesis of hypertension, atherosclerosis, congestive heart failure and associated cardiovascular disease are the renin angiotensin system (RAS) and estrogen. A major effect of estrogen results from its influence on the RAS. Beta-estradiol (E2) replacement in ovariectomized (OVX) rats significantly decreased type 1 angiotensin (AT1) receptor expression in the pituitary and adrenal, whereas it significantly increased receptor expression in the uterus when compared to OVX controls. Additional evidence demonstrated an important influence of estrogen on a recently discovered post-transcriptional mechanism for regulating expression of the AT1 receptor. This mechanism consists of cytosolic RNA binding proteins (BPs) that recognize the 5' leader sequence (5'LS) of the receptor mRNA. The activities of these 5'LS BPs were modulated by estrogen in an inverse manner to AT1 receptor regulation. Moreover, in vitro translation assays in wheat germ lysates suggested that the 5'LS BPs inhibited AT1 receptor translation. Our data therefore indicate that hormonal regulation of AT1 receptors involves modulation of 5'LS BPs by estrogen. These findings may in part account for the observed protective effects of estrogen on cardiovascular disease.

Comparison of milk protein allele frequencies in Nordic cattle breeds

Allele frequencies at four milk protein loci were studied in five modern and 17 old Nordic cattle breeds in order to reveal variants that are characteristic for these populations. The B allele of CSN3, which has been associated with improved manufacturing properties of milk, showed significantly lower frequencies in modern production breeds than in old breeds of interest for conservation purposes. Characteristic frequencies of CSN1S1 (C), CSN2 (A2) and CSN3 (B) were found in Icelandic cattle, Swedish Mountain cattle, Northern Finncattle and Western Fjord cattle, which indicate a common origin of these populations. Further comparisons of allele frequencies in old Nordic breeds suggest sorting of these breeds into two groups with a northern and southern geographic location.

Close association between sequence polymorphism in the KIT gene and the roan coat color in horses

The roan coat color in horses is controlled by a dominant allele that is lethal in the homozygous condition. Phenotypic similarities to some pigmentation disorders in human and mouse, combined with comparative mapping data, identified KIT, encoding the mast cell growth factor receptor, as a major candidate gene for the roan locus (Rn). Rn has previously been mapped to equine linkage group (LG) II. In this study, LGII was expanded with KIT and PDGFRA (platelet-derived growth factor receptor alpha) by use of RFLP and linkage analysis. Moreover, highly significant linkage disequilibrium between Rn and a KIT TaqI RFLP, representing a synonymous substitution in exon 19, was revealed. There was a strong KIT-Rn association in most breeds. Almost the complete KIT-encoding sequence was determined by sequence analysis of RT-PCR products. Comparison of horse KIT cDNA sequences, representing three different alleles (two different rn and one Rn), revealed five sequence polymorphisms and several mRNA splice variants, but none of these proved to be specifically associated with Rn. An insertion of a partial (79 bp) LINE1-element between exons 1 and 2, leading to a frameshift, represented about 30% of KIT transcripts in the Belgian roan horse used for the sequence analysis. However, an association between this L1 splice insertion and the roan phenotype was not verified when testing additional unrelated roan and non-roan horses from different breeds. The study strengthens the hypothesis that the roan coat color is controlled by KIT, but further analyses are needed to reveal the causative mutation(s).

Temporal changes in genetic variation of north European cattle breeds

Temporal changes in genetic variation within and between 13 North European cattle breeds were evaluated using erythrocyte antigen systems and transferrin protein as genetic markers. Current data on allele frequency distributions of markers in large commercial and smaller endangered native cattle breeds were compared to data published during 1956 to 1975. Intrabreed genetic variation was quantified by conventional parameters (e.g. heterozygosity, average number of alleles per locus) and migration by the effective migration rate. The neighbour-joining dendrogram of relationships between old and present cattle populations was constructed using Nei's standard genetic distance. Variance effective population size was estimated from changes in allele frequencies over time. Comparison of old and new data indicated some significant changes in allele frequencies. In six of the breeds, a few low-frequency alleles in the old data were absent in the present samples. Heterozygosity remained stable in most breeds. The harmonic means for variance effective population size ranged between 30 and 257. Current results indicate that despite marked declines in total population sizes, North European native cattle breeds have retained a reasonably high genetic diversity. However, their genes contribute less than previously to genetic variation of Nordic production breeds. Commercial breeds do not appear to have a larger effective population size than native breeds. The present effective population sizes imply that Nordic breeds could have lost from 1 to 11% of their heterozygosity over a 20-40-year period.

Transgenic expression of IFN-alpha in the central nervous system of mice protects against lethal neurotropic viral infection but induces inflammation and neurodegeneration

Type I IFNs, which include IFN-alpha, appear to have complex and broad-ranging actions in the central nervous system (CNS) that may result in protection or injury. To better understand these issues, we generated transgenic mice that produce IFN-alpha1 chronically from astrocytes. These glial fibrillary acidic protein-IFN-alpha transgenic mice developed a progressive inflammatory encephalopathy, with marked calcium mineralization, meninoencephalitis, gliosis, and neurodegeneration. Many features of this murine encephalopathy resembled those found in certain human encephalopathies of unknown etiology; these diseases, exemplified by Aicardi-Goutières syndrome and some viral encephalopathies, show increased intrathecal production of IFN-alpha. Our data suggest that IFN-alpha overproduction may be the primary factor initiating these human diseases. Following intracerebral infection with lymphocytic choriomeningitis virus, glial fibrillary acidic protein-IFN-alpha mice had significantly increased survival rates associated with markedly reduced virus titers and immune pathology in the brain but normal peripheral CTL responses. Therefore, the production of IFN-alpha in the CNS can be a two-edged sword that on the one hand confers protection against a lethal viral infection but on the other causes significant injury to the brain. These transgenic mice provide a novel animal model in which to further evaluate the mechanisms that underlie the diverse actions of type I IFNs in the intact CNS.