Evaluation of the ARKRAY AUTION Eleven reflectometer in detecting microalbuminuria with AUTION Screen test strips and proteinuria with AUTION Sticks 10PA strips.

OBJECTIVE: Albumin/creatinine and protein/creatinine ratios were measured with the ARKRAY AUTION Eleven reflectometer using AUTION Screen and AUTION Sticks 10PA strips, respectively, against quantitative Siemens Advia reference procedures from 368 patient urines, as an evaluation of their applicability for use in points-of-care and small laboratories. MATERIAL AND METHODS: Direct reflectance measurements were utilized to estimate imprecision, as well as to suggest reclassification of ordinal scale categories into normoalbuminuria, microalbuminuria and macroalbuminuria groups (3.4 g/mol and 34 g/mol cut-off limits, corresponding to 30 mg/g and 300 mg/g creatinine in conventional units). RESULTS: Analytically, ordinal scale albumin/creatinine ratios agreed in 86% of cases with those obtained from Advia measurements, resulting in a kappa coefficient of 0.79. Protein/creatinine ratios of the AUTION Sticks 10PA strip were classified into three groups at limits of 11.3 g/mol and 56.6 g/mol (100 mg/g and 500 mg/g in conventional units), with an agreement of 77% and a kappa coefficient of 0.65 against Advia procedures. To optimize clinical outcomes, cut-off reflectances of ordinal scale categories of AUTION Eleven were adjusted. The clinical specificity of detecting an increased albumin/creatinine ratio was then increased from 81% to 95%, with clinical sensitivity kept at 88% at the 3.4 g/mol limit of the reference procedure. Clinical specificity of the albuminuria field alone (at a clinical sensitivity of 88%) was only 73%. Adjustments to cut-off reflectances of the reported categories for protein/creatinine ratios increased clinical specificity from 54% to 94%, while losing clinical sensitivity from 97% to 89% only, with an improved concordance of 83% and a kappa coefficient of 0.75 against Advia measurements. The combination to creatinine measurements improved clinical specificity compared to 50% by the protein field alone. In economic terms, it is estimated that population screening for microalbuminuria using the AUTION Eleven reflectometer is cheaper than by quantitative albumin/creatinine measurements alone, based on the incidence of end-stage renal disease of 90 patients/million/year at the Northern Ostrobothnia Hospital District.

Expression cloning of a novel estrogenic mouse 17 beta-hydroxysteroid dehydrogenase/17-ketosteroid reductase (m17HSD7), previously described as a prolactin receptor-associated protein (PRAP) in rat.

17 beta-Hydroxysteroid dehydrogenases/17-ketosteroid reductases (17HSDs) modulate the biological activity of certain estrogens and androgens by catalyzing reductase or dehydrogenase reactions between 17-keto- and 17 beta-hydroxysteroids. In the present study, we demonstrate expression cloning of a novel type of 17HSD, chronologically named 17HSD type 7, from the HC11 cell line derived from mouse mammary gland. The cloned cDNA, 1.7 kb in size, encodes a protein of 334 amino acids with a calculated molecular mass of 37,317 Da. The primary structure contains segments characteristic of enzymes belonging to the short-chain dehydrogenase/reductase superfamily. Strikingly, mouse 17HSD type 7 (m17HSD7) shows 89% identity with a recently cloned rat protein called PRL receptor-associated protein (PRAP). The function of PRAP has not yet been demonstrated. The enzymatic characteristics of m17HSD7 and RT-PCR-cloned rat PRAP (rPRAP) were analyzed in cultured HEK-293 cells, where both of the enzymes efficiently catalyzed conversion of estrone (E1) to estradiol (E2). With other substrates tested no detectable 17HSD or 20 alpha-hydroxysteroid dehydrogenase activities were found. Kinetic parameters for m17HSD7 further indicate that E1 is a preferred substrate for this enzyme. Relative catalytic efficiencies (Vmax/K(m) values) for E1 and E2 are 244 and 48, respectively. As it is the case with rPRAP, m17HSD7 is most abundantly expressed in the ovaries of pregnant animals. Further studies show that the rat enzyme is primarily expressed in the middle and second half of pregnancy, in parallel with E2 secretion from the corpus luteum. The mRNA for m17HSD7 is also apparent in the placenta, and a slight signal for m17HSD7 is found in the ovaries of adult nonpregnant mice, in the mammary gland, liver, kidney, and testis. Altogether, because of their similar primary structures, enzymatic characteristics, and the tissue distribution of m17HSD7 and rPRAP, we suggest that rPRAP is rat 17HSD type 7. Furthermore, the results indicate that 17HSD7 is an enzyme of E2 biosynthesis, which is predominantly expressed in the corpus luteum of the pregnant animal.

Expression of mouse 17beta-hydroxysteroid dehydrogenase/17-ketosteroid reductase type 7 in the ovary, uterus, and placenta: localization from implantation to late pregnancy.

Rodent 17beta-hydroxysteroid dehydrogenase/17-ketosteroid reductase type 7 (17HSD/KSR7) catalyzes the conversion of estrone (E1) to estradiol (E2) and is abundantly expressed in the ovaries of pregnant animals in particular. In the present work we demonstrate cell-specific expression of 17HSD/KSR7 in the ovaries, uteri, and placentas of pregnant and nonpregnant mice using in situ hybridization. The results show that mouse 17HSD/KSR7 (m17HSD/KSR7) messenger RNA is distinctly and exclusively expressed in a proportion of corpora lutea (CLs). During pregnancy, expression of m17HSD/KSR7 is most abundant around embryonic day 14.5 (E14.5), when the ovaries are filled with CLs expressing 17HSD/KSR7. In the uterus, m17HSD/KSR7 is first detected on E5.5, when expression surrounds the implantation site on the antimesometrial side. As gestation progresses, m17HSD/KSR7 is expressed in the decidua capsularis on E8 and E9.5, disappearing thereafter from the antimesometrial decidua. On E9 onward, m17HSD/KSR7 messenger RNA expression takes place at the junctional zone of the developing placenta. On E12.5 and E14.5, m17HSD/KSR7 is abundantly expressed in the spongiotrophoblasts, where expression gradually declines toward parturition. In conclusion, m17HSD/KSR7 expression in the CL is related to the life span of the CL. Moreover, spatial and temporal expression of m17HSD/KSR7 in the uterus suggests that locally produced E2 plays a role in implantation and/or decidualization. Finally, the results indicate that mouse placenta is capable of converting E1 to E2 in situ, and that the synthesized E2 may be effective in a paracrine, autocrine, and/or intracrine manner and be involved in placentation.

Rat 17 beta-hydroxysteroid dehydrogenase type 1: primary structure and regulation of enzyme expression in rat ovary by diethylstilbestrol and gonadotropins in vivo.

17 beta-Hydroxysteroid dehydrogenase (17HSD) catalyzes the reversible conversion of estrone into estradiol. The complementary DNA (cDNA) coding for rat 17HSD type 1 was cloned from a commercial rat ovarian cDNA library, using human 17HSD type 1 cDNA as a probe. The nucleotide sequence extends for 1160 basepairs (bp), including 1035 bp of open reading frame, a stop codon, and 125 bp of 3'-untranslated sequence. The cDNA encodes a protein of 344 amino acids, with a calculated molecular mass of 36,967 daltons. The overall amino acid identity and similarity between rat and human 17HSD type 1 enzymes are 68% and 80%, respectively. Immunohistochemistry and in situ and Northern hybridizations were used to study regulation of the enzyme in rat ovary in vivo. Enzyme expression was detected in granulosa cells only, whereas no expression was observed in stromal or thecal cells. The enzyme was almost undetectable in ovaries from immature hypophysectomized rats. After 2-day treatment with recombinant FSH (recFSH), an induction of 17HSD type 1 expression was observed in granulosa cells of growing antral follicles. During 5 days of diethylstilbestrol (DES) treatment, a time-dependent increase in developing follicles was observed, showing strong expression of 17HSD type 1 in granulosa cells. Treatment with recFSH for 2 days in DES-primed animals resulted in down-regulation of ovarian enzyme expression. This reduction of enzyme expression was associated with luteinization of the follicles. hCG treatment of recFSH- or DES- plus recFSH-primed animals further induced luteinization, resulting in strong down-regulation of 17HSD type 1 expression. The enzyme was not detected in corpora lutea. The data show that 17HSD type 1 expression in rat ovary is regulated by gonadotropins and estrogens. The results suggest that expression of 17HSD type 1 and that of cytochrome P450 aromatase are regulated by distinct mechanisms, and 17HSD type 1 may be down-regulated earlier than P450 aromatase during luteinization, limiting estradiol biosynthesis in luteinizing granulosa cells in rat ovary.

A patient with 2 different repeat expansion mutations.

BACKGROUND: Many inherited progressive encephalopathies have a poor outcome, and some are caused by repeat expansion mutations. How would the presence of 2 different expansion mutations affect the phenotype? OBJECTIVE: To describe a patient who has 2 distinct, rare genetic disorders: myotonic dystrophy (DM, OMIM 160900) and progressive myoclonus epilepsy of the Unverricht-Lundborg type (EPM1, OMIM 254800). Both conditions are caused by repeat expansion mutations. They affect the central nervous system causing mental retardation, but also produce a wide spectrum of disabilities in daily living. SETTING: Referral center. METHODS: Clinical description with accompanying photographs, electroencephalography and magnetic resonance imaging; DNA analysis of both of the mutations and chromosomal analysis with prometaphase spreads. RESULTS: The patient had clinical characteristics and findings of both myotonic dystrophy and progressive myoclonus epilepsy of the Unverricht-Lundborg type. Electroencephalographic recordings over a 3-year period showed typical findings for myoclonus epilepsy. The patient had no gross anomalies in brain magnetic resonance imaging. She had a normal karyotype, and both of the diagnoses were confirmed at the molecular level with the direct detection of the mutations. CONCLUSIONS: Despite having 2 different progressive inherited disorders affecting the central nervous system, the patient, at age 28 years, showed only mild mental retardation with very slow progression. However, clear deterioration in activities of daily living has taken place during last 3 years. Arch Neurol. 2000;57:1199-1203

Two brothers with macrocephaly, progressive cerebral atrophy and abnormal white matter, severe mental retardation, and Lennox-Gastaut spectrum type epilepsy: an inherited encephalopathy of childhood?

Two brothers with severe mental retardation of unknown origin were found to share several physical anomalies, including large round head, small concave nose, downslanted palpebral fissures, and gingival hyperplasia. In addition to relative macrocephaly, magnetic resonance imaging (MRI) showed severe cerebral atrophy, especially fronto-temporally. The brothers also had a thin corpus callosum and atrophic caudate nuclei. The reduced white matter showed patchy periventricular signal intensity changes. The lateral and third ventricles were large, but the fourth ventricle was of normal size. The boys had large cisterna magna, communicating widely with the fourth ventricle, but no vermian hypoplasia. Both boys had Lennox-Gastaut spectrum type epilepsy. No chromosomal anomalies were found, despite the suggestive clinical picture. Some of the clinical findings resembled fetal alcohol effects/fetal alcohol syndrome (FAE/FAS), which was also suggested by history. Current diagnostic criteria for FAE/FAS, however, excluded full-blown FAS in these cases and failed to explain the entire clinical picture in the boys. We argue that these boys had an unidentified inherited syndrome, possibly modified by fetal alcohol exposure.

Two 17beta-hydroxysteroid dehydrogenases (17HSDs) of estradiol biosynthesis: 17HSD type 1 and type 7.

Two 17beta-hydroxysteroid dehydrogenases (17HSDs), type 1 and type 7, are enzymes of estradiol biosynthesis, in addition to which rodent type 1 enzymes are also able to catalyze androgens. Both of the 17HSDs are abundantly expressed in ovaries, the type 1 enzyme in granulosa cells and type 7 in luteinized cells. The expression of 17HSD7, which has also been described as a prolactin receptor-associated protein (PRAP), is particularly up-regulated in corpus luteum during the second half of rodent pregnancy. A moderate or slight signal for mouse 17HSD7/PRAP mRNA has also been demonstrated in samples of placenta and mammary gland, for example. Human, but not rodent, 17HSD1 is expressed in placenta, breast epithelium and endometrium in addition to ovaries. A cell-specific enhancer, silencer and promoter in the hHSD17B1 gene participate in the regulation of type 1 enzyme expression. The enhancer consists of several subunits, including a retinoic acid response element, the silencer has a binding motif for GATA factors, and the proximal promoter contains adjacent and competing AP-2 and Sp binding sites.

Nonvacuolar myopathy in a large family with both late adult onset distal myopathy and severe proximal muscular dystrophy.

Late adult onset distal myopathies usually show vacuolar degeneration as a characteristic feature in muscle pathology. In this study vacuolar degeneration was not present in 12 patients with late adult onset distal myopathy. All patients were members of a large kindred, with 26 patients showing this new form of distal leg myopathy. Additionally, a severely disabling proximal muscular dystrophy appeared in eight other members of the large consanguineous kindred. Muscle biopsies were obtained from clinically affected muscles, and from clinically unaffected muscles in patients with distal myopathy. For comparison specimens from various muscles of patients with severe proximal dystrophy were also studied. Histopathological changes correlating to muscular dystrophy were extensive in all muscles studied in patients with proximal dystrophy, and in tibial anterior muscles in patients with distal myopathy. Mild myopathic changes, mainly increased internal nuclei in muscle fibers, were detected in clinically unaffected muscles in the distal myopathy. The spectrum of findings is compatible with the hypothesis of previous clinical and genetic studies, indicating that the severe proximal dystrophy could be a homozygous manifestation of the dominantly inherited gene of the distal tibial muscle dystrophy.

A microsatellite polymorphism in the von Willebrand factor gene: comparison of allele frequencies in different population samples and evaluation for forensic medicine.

The allele frequencies at the tetranucleotide repeat (TCTA) vWA locus in the vWF gene were determined in the general Finnish population, in a population representing an internal isolate of Finland, in the Vologda-Russian population, and in US Black population samples. The allele and genotype frequencies from these population samples were compared with each other and with those reported from Spanish and British population samples. Statistically significant differences were demonstrated between most of the different groups (Finns vs. Vologda-Russians, Finns vs. US Blacks, Finns vs. Spanish, Vologda-Russians vs. US Blacks, Vologda-Russians vs. Spanish, US Blacks vs. Spanish and US Blacks vs. British Caucasians), but not between the two Caucasoid population samples from Finland and Great Britain, nor between or within the subpopulation samples from Finland and those from Vologda-Russia. In addition, the vWA marker was evaluated and demonstrated to be reliable for forensic purposes and paternity testing.

Genetic effects on human cognition: lessons from the study of mental retardation syndromes.

The molecular basis of human cognition is still poorly understood, but recent advances in finding genetic mutations that result in cognitive impairment may provide insights into the neurobiology of cognitive function. Here we review the progress that has been made so far and assess what has been learnt from this work on the relation between genes and cognitive processes. We review evidence that the pathway from genetic lesion to cognitive impairment can be dissected, that some genetic effects on cognition are relatively direct and we argue that the study of mental retardation syndromes is giving us new clues about the biological bases of cognition.

Linkage analyses in tibial muscular dystrophy.

Tibial muscular dystrophy (TMD) is a recently described muscular disease first discovered in a highly consanguineous family in Finland. The pedigree also included patients whose symptoms resembled another phenotype, classical limb-girdle muscular dystrophy. Extensive linkage analysis was carried out in this complex pedigree using 157 highly polymorphic DNA markers. Because of the presence of two phenotypes, several inheritance models were used in linkage analysis studies to allow for the possibility of intrafamilial heterogeneity. The results summarize information from over 10,000 genotypings and exclude several known loci for muscular dystrophies. The findings suggest that TMD may be caused by a mutation in a previously unknown locus for muscular dystrophy.

Molecular cloning of mouse 17 beta-hydroxysteroid dehydrogenase type 1 and characterization of enzyme activity.

The biological activity of certain estrogens and androgens is modulated by enzymes called 17 beta-hydroxysteroid dehydrogenases (17 beta-HSDs), which catalyze the interconversion between less active 17-oxosteroid and more active 17 beta-hydroxysteroid forms. In the present report, we describe cloning of mouse 17 beta-HSD type-1 cDNA from an ovarian library generated from 4,4'-(1,2-diethyl-1,2-ethenediyl)bisphenol-(diethylstilbestrol)-tr eated mice, and characterization of the corresponding enzyme. The open reading frame of the mouse 17 beta-HSD type-1 cDNA encodes a peptide of 344 amino acid residues with a predicted molecular mass of 36785 Da. The mouse 17 beta-HSD type-1 enzyme shares 63% and 93% overall identity with human and rat 17 beta-HSD type-1 enzymes, respectively, and the most striking differences between the mouse and human type-1 enzymes are between the amino acid residues 197 and 230 and in the carboxy terminus of the enzymes. Similarly to the human 17 beta-HSD type-1 enzyme, the mouse type-1 enzyme primarily catalyzes reductive reactions from 17-oxo forms to 17 beta-hydroxy forms in intact cultured cells, but unlike the human type-1 enzyme, the mouse enzyme does not prefer phenolic over neutral substrates. Thus, mouse 17 beta-HSD type 1 catalyzes reduction of androst-4-ene-3,17-dione (androstenedione) to 17 beta-hydroxyandrost-4-en-3-one (testosterone) as efficiently as 3 beta-hydroxyestra-1,3,5(10)-trien-17-one (estrone) to estra-1,3,5(10)-triene-3 beta, 17 beta-diol (estradiol). 17 beta-HSD type 1 is predominantly expressed in mouse ovaries, in which it is located in granulosa cells.

Usefulness of chromosome 19 RFLP haplotypes in the diagnosis of myotonic dystrophy.

Three DNA probes (APOC2, PSC11, and LDR152) detecting RFLP polymorphisms were used to test the usefulness of the RFLP approach in myotonic dystrophy (MD) families from the isolated Finnish population. The informativeness of these polymorphisms did not differ from that reported in more mixed populations: in the 13 families of the study most of the 79 meiotic events studied were informative. One known recombinant is included in the study. The highest lod score obtained in the multilocus linkage analysis was z = 5.941 at recombination fraction theta = 0.02. The RFLP results significantly facilitated genetic counseling in problematic cases among the families studied. Although evidence could be found for linkage disequilibrium of the RFLP haplotypes formed in Finnish MD patients, our results do not exclude the possible existence of more than one ancient MD mutation in this population.

The DM mutation; diagnostic applications in the Finnish population.

A pair of marker loci, D19S63 and D19S51, which are tightly linked to the myotonic dystrophy (DM) locus, were used to evaluate diagnostic applicability in the Finnish population. Results were then compared to direct detection of the mutation. The D19S63 locus revealed a linkage disequilibrium, since in 16 DM families as many as 75% of DM chromosomes carried the same allele 3 for D19S63, and 25% carried allele 1. However, when the data for D19S51 and D19S63 were considered together as a haplotype, the statistical significance of this linkage disequilibrium was considerably reduced. As expected, the best method for reliable evaluation of the carrier risk was direct analysis of the mutation. Thirteen particularly difficult cases were resolved and in 46% of them the decision could be made only by direct visualization of the mutation. However, in a few cases where the size of the CTG-repeat expansion was close to the normal size range, linked markers proved to be useful to determine the affected chromosomes. Present findings indicate that analysis of the D19S63 locus coupled to direct demonstration of the mutation provides the basis for DNA diagnostics of DM in the Finnish population.

Comparison of the myotonic dystrophy associated CTG repeat in European and Japanese populations.

Gene amplification using polymerase chain reaction (PCR) was carried out on DNA samples from a total of 92 normal subjects and 52 subjects with myotonic dystrophy (DM) from European and Japanese populations, to determine the copy number of the CTG repeat associated with DM for each group. In the two populations, the number of repeats on normal chromosomes only were compared, as CTG copy number on DM chromosomes was difficult to determine by PCR alone. In this study, normal chromosomes were found which had as many as 35 copies of the repeat, which is larger than the normal range reported previously but still does not overlap with the repeat number associated with DM pathology, which is at least 50 copies. Using data from normal chromosomes from unrelated subjects, the frequencies of five, 11, and 13 copies of the CTG repeat were found to be significantly different between the two populations, with five and 11 copies more commonly seen in the European population and 13 copies in the Japanese population. This difference may be the result of natural divergence of the normal chromosomes between the population groups.

Linkage disequilibrium detected between dystrophia myotonica and APOC2 locus in the Finnish population.

Three polymorphic loci APOC2, CKMM and p134C were used to haplotype 15 Finnish dystrophia myotonica (DM) families representing about one third of all DM patients in this isolated population. Compound APOC2 and CKMM haplotypes reveal linkage disequilibrium: 90% of DM chromosomes co-occur with the haplotypes that occur in 31% of normal chromosomes only. The same disequilibrium is present when only polymorphisms occurring at the APOC2 locus are used. Surprisingly, no statistically significant linkage disequilibrium was discovered at the CKMM locus alone. Of the meiotic events, 84% were informative when both APO2 and CKMM loci were used. When studied selectively, 60% of meiotic events were informative at the APOC2 locus, whereas CKMM alone resulted in 65% meiotic informativeness. The distal marker p134C was found to have an unfortunately low information content in our population.