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M Julkunen

Publications and source records attributed to M Julkunen.

At least 19 recordsLinked to original sources
PubMed2001

The structure of parasite component communities in brackish water fishes of the northeastern Baltic Sea.

We used nestedness analysis to seek non-random patterns in the structure of component communities of metazoan parasites collected from 31 sympatric fish species from the northeastern Bothnian Bay, the most oligohaline area of the Baltic Sea. Only 8 marine parasite species were found among the 63 species recorded, although some marine fish species reproduce in the bay and others occasionally visit the area. Marine parasite species can utilize both freshwater and marine fish species as intermediate or final hosts, and marine fish can harbour freshwater parasite species. This exchange of parasite species between marine and freshwater fish has probably resulted from ecological factors acting over short time scales rather than from evolutionary processes acting over longer time; the key factor probably being the immediate presence of suitable intermediate and definitive hosts. Marine fish were expected to harbour species-poor parasite communities consisting mainly of generalists acquired from the sympatric freshwater fish species, which would result in a nested pattern among the different component communities. However, an anti-nested pattern was found in the component communities of metazoan parasites of fishes from the Bothnian Bay. A likely explanation for the observed pattern is that there are specialist parasite species, the majority of which are cestodes, in some of the freshwater fish species which otherwise have depauperate parasite communities.

Animals↗
PubMed1996

Normal human ovary and ovarian tumors express glycodelin, a glycoprotein with immunosuppressive and contraceptive properties.

Glycodelin is a glycoprotein with potent immunosuppressive and contraceptive activities. It reacts with antibodies against placental protein 14, or progesterone-associated endometrial protein, and has a unique carbohydrate structure. Previous nomenclature is misleading, because glycodelin is neither synthesized in the placenta nor is it endometrium specific. No ovarian synthesis of glycodelin has been demonstrated. We present evidence for glycodelin synthesis in the human ovary and ovarian tumors. In follicular phase, immunoperoxidase staining of microwave-treated tissue sections employing affinity-purified polyclonal antibodies localized glycodelin to areas of stromal cell condensation in ovarian cortex, theca interna, and the granulosa. In luteal phase, cortical stroma was negative or only weakly positive, whereas glycodelin was present in theca interna of the corpus luteum and luteinized granulosa cells and also in corpus albicans and Leydig cells of the ovarian hilus. In situ hybridization gave negative results for glycodelin mRNA in normal ovary, whereas in ovarian tumors strong expression of both the glycodelin mRNA and the protein were found in benign and malignant serous cystadenomas, mucinous ovarian tumors being negative. We conclude that glycodelin is synthesized in human ovarian tumors, and its occurrence in normal human ovary may represent either synthesis or a site of glycodelin action.

Adult↗
PubMed1995

Habitual abortion is accompanied by low serum levels of placental protein 14 in the luteal phase of the fertile cycle.

OBJECTIVE: To study serum levels of placental protein 14 (PP14) in relation to endometrial function in women with a history of habitual abortion. DESIGN: Prospective study. SETTING: Departments I and II of Obstetrics and Gynecology, University Central Hospital of Helsinki, Helsinki, Finland. PATIENTS: Fifty patients (26 primary and 24 secondary habitual aborters) and 38 controls without a history of abortion studied during a regular cycle. RESULTS: Habitual aborters as a whole or when subgrouped into those with normal cycles (n = 40) or with a luteal phase defect (LPD; n = 10) and control women demonstrated a distinct increase in PP14 levels from late follicular to late luteal phases. In the luteal phase, serum PP14 levels were lower in the patients than in the controls (27.2 +/- 3.1 versus 48.5 +/- 10.1 micrograms/L), but the differences in PP14 levels between habitual aborters with or without LPD was not significant (16.3 +/- 4.3 versus 29.9 +/- 3.7 micrograms/L). CONCLUSIONS: Habitual aborters exhibit lower serum PP14 levels in the late luteal phase compared with normal fertile women.

Abortion, Habitual↗
PubMed1994

Serum placental protein 14 concentrations are similar in the first trimester pregnancies of women after pituitary down-regulation with a gonadotrophin-releasing hormone agonist and normal cycles with frozen embryo transfers.

Previous studies suggest that, in pregnancies after in-vitro fertilization (IVF) and embryo transfer following pituitary down-regulation with a gonadotrophin-releasing hormone analogue (buserelin) and ovulation induction with human gonadotrophins, the serum placental protein 14 (PP14) concentration is lower than in normally conceived pregnancies. We studied serum PP14 concentrations in two groups of women: (i) in 17 infertile women whose pregnancy followed IVF and embryo transfer using buserelin (long protocol) and human menopausal gonadotrophin for ovulation induction; (ii) in 15 women whose pregnancy followed transfer of frozen-thawed embryos. Similar PP14 concentrations were found in both groups on days 9-10, 14-15 and 70-77 after human chorionic gonadotrophin administration (buserelin, IVF/embryo transfer) or spontaneous luteinizing hormone surge (frozen-thawed embryo transfer). Our results show that PP14 secretion is not compromised by pituitary down-regulation with buserelin in infertile women with functional ovaries.

Buserelin↗
PubMed1993

Tri-iodothyronine and cycloheximide enhance insulin-like growth factor-binding protein-1 gene expression in human hepatoma cells.

The growth-regulating actions of IGFs are modulated by their binding proteins (IGFBPs). The serum concentration of IGFBP-1 is down-regulated by insulin, and in-vitro studies have demonstrated that IGFBP-1 secretion from various tissues and cells can be stimulated by theophylline, forskolin, oestrogen and progesterone. We have studied the effects and mechanisms of thyroid hormone action on IGFBP-1 gene expression and secretion by human hepatoma cells in vitro. Tri-iodothyronine dose-dependently enhanced IGFBP-1 secretion in serum-free HepG2 cell cultures after 24-48 h of exposure, as measured by a specific immunofluorometric assay. This was accompanied by an increase (+ 50%) in the amount of IGFBP-1 mRNA, which could be prevented by cycloheximide, a protein synthesis inhibitor. Cycloheximide transiently enhanced (+ 200%) the accumulation of IGFBP-1 mRNA at 3-12 h of incubation, when no effect of tri-iodothyronine was observed. It is concluded that thyroid hormone stimulates IGFBP-1 secretion slowly by enhancing IGFBP-1 gene expression by a protein mediator. The acute stimulation of IGFBP-1 gene transcription by cycloheximide associates this gene with a number of growth-related genes encoding growth- and tumour-associated peptides.

Carrier Proteins↗
PubMed1993

Localization of progesterone-associated endometrial protein mRNA by in-situ hybridization in human pregnancy decidua, endometriosis and borderline endometrioid adenoma.

Progesterone-associated endometrial protein (PAEP) has been isolated from human decidualized endometrium. In-situ hybridization histochemistry was employed to determine the cellular localization of PAEP mRNA in decidua during pregnancy. PAEP mRNA was found to be expressed in the glandular epithelium of decidua spongiosa throughout pregnancy. Substantial variations in the amount of PAEP mRNA during the course of pregnancy were observed, and it was most abundant at the end of the first trimester. We also found that the PAEP gene was expressed in endometriosis and in a borderline endometrioid adenoma. As in decidual tissues, PAEP mRNA in endometriosis was abundant in the glandular compartment.

Adenoma↗
PubMed1992

Expression of insulin-like growth factor binding protein-1 mRNA in human fetal kidney.

Expression of insulin-like growth factor binding protein-1 (IGFBP-1) messenger RNA (mRNA) was studied in tissues of human fetuses from 15 to 23 weeks of gestation. Northern blot analysis revealed IGFBP-1 mRNA in the fetal liver and kidney but not in other fetal tissues, including the brain, heart, lung, skeletal muscle and spleen. Studies by in situ hybridization histochemistry showed that, in all fetal kidneys tested, the IGFBP-1 mRNA was localized preferentially to the epithelial cells of the collecting ducts, as well as to the cells of developing glomeruli and in the subcapsular nephrogenic mesenchyme. Less intense labeling for IGFBP-1 mRNA was seen in the connective tissue stroma of the medullary pyramids. A weak signal was detected in the mature glomeruli, and in the cells of the medullary mesenchyme and capsular connective tissue. IGFBP-1 protein was detected by immunoperoxidase staining mostly around small blood vessels but not in the respective endothelium. The protein was also present in many epithelial cells of the collecting ducts and in stromal connective tissue. These results show that the predominant sites of IGFBP-1 transcription in the developing kidney are those with most active differentiation.

Antibodies, Monoclonal↗
PubMed1992

Endometrial proteins: a reappraisal.

Uterine factors influence reproduction at the macro-anatomy level, and the effects of hormonal steroids on endometrial morphology are well recognized in the histopathological diagnosis of dysfunctional bleeding and infertility. During the past decade, attention has been paid to endometrial protein synthesis and secretion with respect to endocrine stimuli and implantation, and to the paracrine/autocrine effects of endometrial peptide growth factors, their binding proteins and other factors. The emphasis of this presentation is on protein secretion of the secretory endometrium, in which progesterone plays a pivotal role. Insulin-like growth factors have receptors on the endometrium, and IGF-binding proteins, stimulated by progesterone, modulate the effects of IGFs locally. Also other protein products of the secretory endometrium have been reviewed in this communication, with special emphasis on studies of a progesterone-associated endometrial protein which has many names in the literature, such as PEP, PP14, alpha 2-PEG and AUP. Extensive studies are ongoing in many laboratories to elucidate the regulation, function, interplay at tissue and cellular levels, and clinical significance of these proteins.

Carrier Proteins↗
PubMed1992

Comparison of androgen regulation of ornithine decarboxylase and S-adenosylmethionine decarboxylase gene expression in rodent kidney and accessory sex organs.

Androgen regulation of ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC) activities and accumulation of the mRNAs encoding these two enzymes in rodent kidney and accessory sex organs were studied. The ODC mRNA concentration and enzyme activity were increased by androgens in kidney, prostate, and seminal vesicle of 3-day castrated mice and rats, whereas AdoMetDC mRNA and protein levels were androgen inducible only in rodent accessory sex organs. ODC and AdoMetDC mRNAs were regulated in prostate and seminal vesicles in a coordinate fashion, with the maximal levels reached within 24-48 h of steroid exposure. The extent of induction was similar for the two gene products, and ODC and AdoMetDC mRNA accumulation occurred primarily in epithelial cells of accessory sex organs, as shown by in situ hybridization studies. The murine ODC promoter contains an androgen-responsive element (ARE)-like sequence at about -910 nucleotides from the cap site; this element binds to androgen receptor in vitro, albeit with much lower affinity than some other AREs. In transient expression studies with CV-1 cells, an ODC promoter construct (pODCCAT) conferred androgen responsiveness upon the reporter gene. ODC mRNA accumulation is androgen regulated in epithelial cells of proximal tubules in both murine and rat kidney; however, different subtypes of the proximal tubular cells respond in the two species, as revealed by in situ hybridization studies. Expression of the ODC gene was induced more markedly and for a longer duration in the murine than in the rat kidney, but the initial response occurred faster in the rat kidney. The relatively slow kinetics of ODC mRNA accumulation in mouse kidney were not due to recruitment of new cells to respond; rather, in situ hybridization studies indicated that there was progressive accumulation of the mRNA in the responding cells. Collectively, these data indicate that the genes for two key enzymes in polyamine biosynthesis are not regulated in an identical fashion in different androgen target tissues, such as rodent kidney and accessory sex organs.

Adenosylmethionine Decarboxylase↗
PubMed1991

Molecular cloning of complementary DNAs for two human endometrial proteins and cellular localization of their messenger RNAs.

Insulin-like growth factor binding protein-1 (IGFBP-1) and a human beta-lactoglobulin homologue (beta LG/PP14) are two major secretory proteins of the human endometrium. The genes coding for these two proteins are expressed in separate types of the endometrial cells, with the IGFBP-1 gene being expressed in the stromal and the beta LG/PP14 gene in the glandular epithelial cells. Although the biological reasons for the presence and expression of IGFBP-1 and beta LG/PP14 in human endometrial cells remain to be elucidated, the fact that these gene products are expressed in different endometrial cell types provides a unique opportunity to employ them as markers in studies on epithelial-to-stromal cell communication in the endometrium. The primary structures of these proteins have been deduced from their cloned cDNAs. beta LG/PP14 is highly homologous to all known beta-lactoglobulins from various species. For example, horse beta-lactoglobulin I monomer exhibits a 53% protein sequence identity with beta LG/PP14; they have the same number of amino acid residues, and their three-dimensional structures are predicted to be similar. This latter conclusion is inferred from the fact that the four cysteinyl residues that are responsible for the formation of intramolecular bridges in beta-lactoglobulins are spatially conserved in beta LG/PP14. The human protein is encoded by a 900-base pair-long mRNA that is expressed in the glandular epithelial cells of the endometrium in a cyclic manner; in addition, it is found in the mucosal epithelial cells of the fallopian tubes. Several lines of circumstantial evidence suggest that the expression of the beta LG/PP14 gene is regulated by progesterone; however, whether this regulation is elicited by the progesterone receptor at the transcriptional level has not so far been demonstrated. The IGFBP-1 protein sequence contains 259 amino acid residues, with the propeptide possessing a 25-amino acid-long signal peptide. The NH2-terminal sequence of this and other IGFBPs is very cysteine-rich, suggesting the possibility that this domain is involved in the binding of IGF-I and IGF-II ligands. A PEST region, a sequence that is found in proteins with short intracellular half-lives, is included in the middle half of the IGFBP-1 polypeptide. Among the IGFBPs, IGFBP-1 appears to be the only one with a PEST sequence. The carboxy-terminal end of IGFBP-1 contains an Arg-Gly-Asp tripeptide that is also found in IGFBP-2 and may function as a cell attachment recognition signal in these proteins.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1990

Identification by hybridization histochemistry of human endometrial cells expressing mRNAs encoding a uterine beta-lactoglobulin homologue and insulin-like growth factor-binding protein-1.

A beta-lactoglobulin homologue (beta LG/PP14) and insulin-like growth factor-binding protein-1 (IGFBP-1) are two major secretory proteins of the human endometrium. In the present study, we have shown that beta LG/PP14 mRNA is expressed in the endometrium in a cyclic manner, being hardly detectable in midcycle and most abundant during the late secretory phase. IGFBP-1 mRNA is also expressed in endometrium, but in amounts smaller than those encoding beta LG/PP14 and with maximal accumulation earlier in the secretory phase. The expression of these two mRNAs occurs in different cell types of the endometrium, as revealed by in situ hybridization techniques using single-stranded RNA probes. The glandular epithelial cells accumulate beta LG/PP14 mRNA during the late secretory phase of the cycle, whereas only the stromal cells of the late secretory endometrium express IGFBP-1 mRNA. In contrast to the endometrium, the two mRNAs are present at very low abundance in the fallopian tubes where they are expressed in the epithelial cells of the mucosa.

Carrier Proteins↗
PubMed1989

Purification and characterization of endometrial protein PP14 from mid-trimester amniotic fluid.

Two methods are described for the purification of placental protein 14 from human mid-trimester amniotic fluid. The first includes gel filtration, anion exchange chromatography, and reversed-phase high performance liquid chromatography. The second method employs octyl-Sepharose chromatography instead of high performance liquid chromatography, and it also includes an anti-hCG adsorption step in order to remove the remaining traces of hCG from the purified PP14. In the first method, 362 micrograms of PP14 was recovered from 26 ml amniotic fluid with a final recovery of 25%. In the second method, 745 micrograms of PP14 was recovered from 200 ml amniotic fluid with a final recovery of 9.8%. As a result of either method sodium dodecyl sulfate polyacrylamide gel electrophoresis of purified protein showed one band at 28 kDa. Polyclonal antibodies against placental PP14 reacted with this band in immunoblot analysis and radioimmunoassay. A single N-terminal amino acid sequence of M D I P Q T K Q D L E L P K L A G T W H S M A was obtained for the isolated protein. This sequence is identical to that previously reported for human placental PP14. Due to its high PP14 concentration amniotic fluid serves as an excellent starting material for purification of this protein.

Amino Acid Sequence↗
PubMed1989

The gene encoding human low-molecular weight insulin-like growth-factor binding protein (IGF-BP25): regional localization to 7p12-p13 and description of a DNA polymorphism.

The low-molecular weight insulin-like growth-factor binding protein (IGF-BP25) is synthesized by human liver, secretory endometrium and decidua, and is also present in human serum. It binds insulin-like growth factors IGF-I and IGF-II with high affinity, and is proposed to act as a paracrine regulator of cell growth. In situ hybridization studies with a cDNA encompassing the entire protein coding region of IGF-BP25 localized the gene to bands p12-p13 on chromosome 7. Southern blot analysis with the enzyme BglII revealed a common restriction fragment length polymorphism: the presence of the polymorphic BglII site results in the formation of two fragments 4.6 kb and 1.6 kb in size whereas its absence produces a single 6.2 kb fragment. The frequencies of the two alleles were 0.73 and 0.27, respectively. IGF-BP25 constitutes a useful genetic marker for the proximal short arm of chromosome 7.

Blotting, Southern↗