Identification of isoflavones in the roots of Pueraria lobata

The isoflavones of the roots of Pueraria lobata (Willd.) Ohwi (Puerariae Radix) were investigated by high-performance liquid chromatography (HPLC) coupled to photodiode array (PDA) and to mass spectroscopy (MS) using atmospheric pressure chemical ionization (APCI) or electrospray ionization (ESI) in combination with collision-activated decomposition (CAD) (HPLC-APCI-CAD-MS or ESI-CAD-MS) for identification of glycosides and HPLC-APCI-CAD-MS for identification of aglycones. The major glycosides are derived from daidzein ( 9) and most are 8- C-glycosides. 3'-Hydroxypuerarin-4'- O-deoxyhexoside ( 2B) and 3'-methoxy-6''- O- D-xylosylpuerarin ( 6) were identified as new constituents. MS data were obtained for puerarin-4'- O- D-glucoside ( 1), 3'-hydroxypuerarin ( 2A), puerarin ( 3), 3'-methoxypuerarin ( 4), 6''- O- D-xylosylpuerarin ( 5), daidzin ( 7) and 3'-methoxydaidzin ( 8), which were previously characterized by NMR analysis. Isoflavones identified in Puerariae Radix comprise 3'-methoxydaidzein ( 10), genistein ( 12), daidzein-7- O-methyl ether ( 13A), 3'-methoxydaidzein-7- O-methyl ether or 3'-methoxyformononetin ( 13B) and biochanin A ( 15), while previous characterization of daidzein ( 9) and formononetin ( 14) was substantiated by MS data. The structure of compound 11 could not be established by MS techniques. The estrogenic activity was mainly located in the aglycone fraction.

Parathyroid hormone-related protein in patients with primary breast cancer and eucalcemia

Parathyroid hormone-related protein (PTHrP) is a causative factor of humoral hypercalcemia in breast cancer and other malignancies. We studied circulating PTHrP levels with three different immunoassays directed against different parts of the PTHrP molecule in 48 patients with breast cancer and eucalcemia. The methods used were: (a) a RIA with antibodies directed toward the midregion (63-78); (b) an immunofluorometric assay with two antibodies against 1-34 and 38-67; and (c) an immunoradiometric assay with antibodies against 1-40 and 1-72. Although most patients had PTHrP levels indistinguishable from normal when measured by all three methods, four patients had increased serum levels in the IFMA. PTHrP was detected by immunohistochemistry in tumors from nearly all patients. One patient with elevated PTHrP in plasma measured by IFMA showed intense staining of tumor by immunohistochemistry; the tumor was histologically graded as III (severe) and was the largest of all tumors in this patient group. The IFMA can identify increased serum PTHrP in some patients with breast cancer who are not hypercalcemic. This assay may be especially useful in screening patients for this tumor during a relative early phase of the disease.

Quantification of parathyroid hormone-related protein mRNA by competitive PCR and time-resolved lanthanide fluorometry

Using dissociation and enhancement time-resolved lanthanide fluorometry, we have developed a quantitative competitive (QC)-PCR for measuring parathyroid hormone-related protein (PTHrP) mRNA after reverse transcription. A cloned PTHrP cDNA target was also modified by deletion of 10 bp and insertion of 21 bp in the midregion of the fragment and cloned for use as a competitor (i.e., internal standard). Two primers spanning 362 bp of target and 373 bp of competitor were designed and one of the primers was biotinylated. Two oligonucleotide probes, one recognizing the target and the other hybridizing to the competitor, were labeled with Eu chelate. Two equal aliquots of PCR products were assayed with each probe separately in streptavidin-coated wells. After 35 PCR cycles, the competitor signal decreased exponentially (y = e(3.74 - 0.624x); r2 = 0.965) and the target signal increased exponentially (y = e(1.14 + 0.497x); r2 = 0.984) when 1000 copies/tube of the competitor and 0-100,000 copies/tube of the target DNA were added. Log-transformed data for the ratio of target to competitor signals (y) and the copies of the target DNA added (x) were used for plotting the linear calibration curve (y = 2.79 + 2.76x; r2 = 0.976). This QC-PCR enables analysis of multiple samples simultaneously and can be used to study PTHrP gene expression in malignancy and physiology.

Gene structure and chromosome localization of the G gamma c subunit of human cone G-protein (GNGT2)

Phototransduction in the vertebrate rod and cone photoreceptors is regulated by structurally homologous and yet distinct groups of signaling proteins. We have previously identified in bovine retinas a cone-specific G-protein gamma subunit (G gamma c, previously named G gamma b), which may play a key role in coupling the cone visual pigment to phosphodiesterase (O. C. Ong et al., 1995, J. Biol. Chem. 270:8495-8500). We report here the characterization of human G gamma c and its gene structure. Human G gamma c subunit shares a high degree of sequence identity with the corresponding bovine G gamma c isoform (85%) and human rod G gamma 1 (63%). The protein is specifically localized in cones, as indicated by immunohistochemical staining using anti-G gamma c antibodies. Nucleotide sequence analysis of the G gamma c gene (GNGT2) reveals a structure consisting of three exons and two introns, with the intron splice sites similar to that of the rod G gamma 1 gene (GNGT1). By using fluorescence in situ hybridization, we have further localized the human GNGT2 gene to chromosome 17q21. The elucidation of the G gamma c gene structure would facilitate the identification of genetic defects associated with cone degeneration.

Effect of acute endurance and strength exercise on circulating calcium-regulating hormones and bone markers in young healthy males

Physical activity plays a role in the maintenance of the skeleton but the mechanical, metabolic and hormonal mechanisms involved are largely unknown. The influence of acute endurance and strength exercise on circulating levels of calcitonin, parathyroid hormone (PTH), PTH-related peptide (PTHrP), osteocalcin, carboxyterminal cross-linked telopeptide of type I collagen (ICTP) and ionized calcium (Ca2+) was therefore evaluated. Eight healthy young males performed three exercise bouts on separate occasions: endurance exercise, i.e. cycling on a cycle ergometer for 45 min at 55% of Vo2max (E55%) and 15 min at 85% of Vo2max (E85%) and strength exercise at 85% of three repetitions maximum using a leg-press device (STR). Control experiments included the same subjects with the same time schedule but without exercise. Blood samples were taken before, immediately after exercise and during the recovery period. Hormones and bone markers were measured by use of various immunoassays. There was no obvious influence on calcitonin and PTHrP levels, whereas PTH was increased after strength exercise. ICTP and osteocalcin levels correlated positively at all times and showed regular variations. In comparison with the controls, ICTP levels showed a more pronounced decrease following physical activity whereas osteocalcin followed the same pattern as the controls except for after prolonged endurance exercise when a decrease was abolished. In conclusion, an increase in PTH after strength exercise and a pronounced decrease in ICTP after all exercise together with a relative increase in osteocalcin after prolonged endurance exercise might reflect some mechanisms involved in the positive effect of physical activity on bone mass.

Parathyroid hormone-related protein in neonatal and reproductive goats determined by a sensitive time-resolved immunofluorometric assay

OBJECTIVE

High concentrations of parathyroid hormone-related protein (PTHrP) have been found in goat milk but it is not known whether it can enter the circulation of the neonate. In this study we have developed a sensitive two-site lanthanide immunofluorometric assay (IFMA) using dissociation and enhancement time-resolved fluorometry to address this question.

METHOD

Affinity-purified anti-PTHrP 38-67 raised in rabbit was biotinylated and immobilized in streptavidin-coated microtitration wells as a 'capture' antibody. As a signal, affinity-purified anti-PTHrP 1-34, raised in sheep, was labeled with an europium chelate. A sensitivity of 0.3 pmol/l was achieved. PTHrP levels were determined in the plasma of eleven neonatal, seven parturient and six non-pregnant, non-lactating goats as well as in goat milk.

RESULTS

The circulating PTHrP levels (mean +/- S.D.) were significantly increased at day 1 (6.1 +/- 1.7 pmol/l: P < 0.01) and day 3 (3.5 +/- 0.6 pmol/l: P < 0.05) after birth in the male kids (n = 8) bottle-fed with milk from the dams, compared with before (2.2 +/- 0.7 pmol/l) and 30 min after (2.0 +/- 0.6 pmol/l) the first feeding and 14 days (2.4 +/- 0.8 pmol/l) later. In the female kids (n = 3) fed with formula there was no such increase and the concentrations remained between 1.6-1.9 pmol/l. In the parturient goats the mean +/- S.D. PTHrP levels before, during and after parturition were 2.9 +/- 1.7, 4.2 +/- 2.4 and 3.7 +/- 2.2 pmol/l respectively (n = 7) which demonstrated that plasma PTHrP was higher during and after parturition in comparison with before (P < 0.05). The levels in non-pregnant, non-lactating goats were 3.3 +/- 1.5 pmol/l (n = 6). PTHrP levels in goat milk were in the nanomolar range and were highest in the colostrum.

CONCLUSIONS

A significant increase of plasma PTHrP was observed in goat kids fed with milk from their dams and this increase was not found in kids fed with formula. Plasma PTHrP was also increased during parturition.

Postsurgical intraperitoneal exposure to glove powders modulates inflammatory and immune-related cytokine production

The objective of the present study was to determine whether intraperitoneal exposure to glove powders modulates the inflammatory and immune responses by altering the influx of inflammatory and immune cells and peritoneal fluid cytokines and thus the outcome of surgically induced peritoneal wound healing. Peritoneal wall injuries were made by scraping the tissue until bleeding occurred in 360 mice. One of the following fluids was then introduced into the peritoneal cavity: phosphate-buffered saline solution, phosphate-buffered saline solution containing glove powders (Biosorb and Keoflo, 100 microg/ml), Hydrocote (Hydrogel film, Biogel 100 microg/ml), latex proteins (1 mg/ml), or lipopolysaccharides (12.5 microg/ml). At intervals of 1 to 28 days after injury, 10 mice per treatment per day and 10 uninjured mice were killed, peritoneal fluids were collected to determine the cytokine levels, the rate of fibrous adhesions formed at the site of injuries was graded, and peritoneal walls with attached fibrous adhesions were removed to determine the degree of inflammatory and immune cell infiltration into the wound. The results indicated that, with the exception of interferon-gamma, the peritoneal fluid levels of transforming growth factor-beta1, tumor necrosis factor-alpha, interleukin-1beta, and granulocyte-macrophage-colony stimulating factor in the phosphate-buffered saline solution-treated injured group significantly increased, reaching maximum between days 4 and 7 (p < 0.05) compared with the uninjured group and returned to uninjured values by day 14 after injury. The level of transforming growth factor-beta1 was higher in glove powders and Hydrocote-treated groups than in latex, lipo-saccharides, or phosphate-buffered saline solution-treated groups until day 14 after surgery (p < 0.05). The levels of tumor necrosis factor-alpha and interleukin-1beta increased in all treatment groups during the first week after injury compared with uninjured controls, with the exception of Hydrocote. The number of T helper/inducers (CD4), total leukocytes (CD11a), B lymphocytes (CD45R), granulocytes (Gr-1), and mononuclear phagocytes (Mac-3) in the wound increased during the first week after peritoneal wounding with no significant difference between treated and untreated groups. The rate of adhesion formation was not significantly altered in treated compared with untreated groups. These data suggest that a mechanism which mediates glove powder-induced peritoneal inflammatory and immune reactions in the postsurgical setting involves augmentation of cytokine production without influencing the influx of inflammatory and immune cells or adhesion formation.

Two-site immunofluorometric assay of intact salmon calcitonin with improved sensitivity

We recently developed a two-site immunofluorometric assay (IFMA) of salmon calcitonin (SCT) by DELFIA (dissociation enhancement lanthanide fluoroimmunoassay) technique using the same polyclonal antibodies both for "catching" the antigen and for signaling. In the present study we used a monoclonal antibody to SCT 1-11 as the capture antibody. This antibody was biotinylated before use in streptavidin-coated microtitration plates. The polyclonal antibody labeled with Eu chelate was used as a signaling marker. This combination of antibodies resulted in an assay that was three to four times more sensitive than the previous IFMA, with a detection limit of 0.3 pmol/L serum. Intact SCT 1-32 was detected by the assay (recoveries 94-96%), but not the fragments SCT 1-11 and SCT 10-32 or human calcitonin. Dilutions of plasma samples containing SCT were parallel to the calibration curve of SCT 1-32. Pharmacokinetic studies of SCT, 100 IU administered intramuscularly to 10 men, indicated peak serum concentrations of 32-128 pmol/L within 10-20 min with apparent half-life of 56+/-18 min (mean+/-SD). This new assay will allow study of the pharmacokinetics of new calcitonin preparations that do not require injection.

Gonadotropin-releasing hormone (GnRH) and GnRH receptor gene expression in human myometrium and leiomyomata and the direct action of GnRH analogs on myometrial smooth muscle cells and interaction with ovarian steroids in vitro

The objective of the present study was to determine whether GnRH and GnRH receptor are expressed in myometrium and leiomyomata, and if GnRH analogs alone or in the presence of ovarian steroids can modulate the rate of DNA synthesis, proliferation, and transforming growth factor-beta 1 (TGF beta 1) production in myometrial smooth muscle cells in vitro. Reverse transcription-PCR revealed that leiomyomata, unaffected myometrium, and isolated myometrial smooth muscle cells express GnRH and GnRH receptor messenger ribonucleic acid. Furthermore, in a dose-dependent manner, GnRH agonist (leuprolide acetate) inhibited, but GnRH antagonist [D-pGlu1,D-Phe2,D-Trp3.6] (GnRH-Ant1) stimulated, the rate of [3H]thymidine incorporation into myometrial smooth muscle cells (P < 0.05), whereas GnRH-Ant2 (Ac-D-P-Cl-Phe1.2,D-Trp3,D-Arg6,D-Ala10) had no effect. 17 beta-Estradiol (E2) medroxyprogesterone acetate (MPA), and E2 plus MPA (1 micromol/L) stimulated the rate of DNA synthesis by smooth muscle cells (P < 0.05), which was inhibited by GnRH analogs used at 5 micromol/L (P < 0.05). GnRH analogs had no significant effect on myometrial smooth muscle cell proliferation, with the exception of GnRH-Ant1; however, they inhibited the stimulatory action of E2, MPA, and E2 plus MPA in a time-dependent manner (P < 0.05). These cells also synthesized and released approximately 1.32 +/- 0.02 ng/mL total (active plus latent) TGF beta 1, of which 0.73 +/- 0.02 ng/mL was in an active form. E2, MPA, E2 plus MPA, and GnRH analog treatments resulted in an increase in total TGF beta 1 production, whereas GnRH agonist and GnRH-Ant2, but not GnRH-An1, inhibited active TGF beta 1 (P < 0.05). GnRH analogs also inhibited the action of E2 plus MPA on total and active TGF beta 1 production, whereas GnRH-Ant1 further stimulated E2, MPA, or E2 plus MPA action on active TGF beta 1 production (P < 0.05). The data demonstrate for the first time that GnRH and GnRH receptor messenger ribonucleic acid are expressed in myometrium, leiomyomata, and myometrial smooth muscle cells. The local expression of GnRH and receptor along with the direct action of GnRH analogs on the smooth muscle cell DNA synthesis and TGF beta 1 production suggest an autocrine/paracrine role for GnRH in these tissues, a mechanism that may be involved in leiomyomata regression in women receiving GnRH agonist therapy.

Suppression of transforming growth factor-beta (TGF beta) and TGF beta receptor messenger ribonucleic acid and protein expression in leiomyomata in women receiving gonadotropin-releasing hormone agonist therapy

The expression and cellular distribution of transforming growth factor-1 (TGF beta 1) through TGF beta 3 and TGF beta type I-III receptor messenger ribonucleic acid (mRNA) and protein were analyzed in leiomyomata from patients receiving GnRH agonist (GnRHa; leuprolide acetate) compared to those in untreated controls. Standard reverse transcription-PCR revealed that the unaffected myometrium and leiomyomata from leuprolide-treated and untreated patients express TGF beta 1-3 and TGF beta type I-III receptor mRNA. The myometrial and leiomyomata smooth muscle cells were the primary site of TGF beta 1-3 and TGF beta type I and II receptor mRNA and protein expression, as determined by in situ hybridization and immunohistochemical localization. These observations indicate that leiomyomata express a higher of level of TGF beta and TGF beta receptor mRNA and protein than unaffected myometrium during the secretory phase of the menstrual cycle, and women who received leuprolide acetate therapy had a substantially lower level of expression than untreated controls. Furthermore, competition-based quantitative reverse transcription-PCR using synthetic internal standards revealed that leiomyomata express a significantly higher number (copies per cell) of TGF beta type II receptor mRNA, followed by TGF beta 1, TGF beta type I receptor, TGF beta 2, and TGF beta 3 (P < 0.05). However, there was a significant decrease in the levels (copies per cell) of TGF beta 1, TGF beta 3, and TGF beta type I and type II receptor mRNA expression in leiomyomata from leuprolide-treated compared to untreated patients (P < 0.05). The data provide further evidence that leiomyomata express mRNA and protein for all components of the TGF beta system, and GnRHa therapy results in down-regulation of their expression. More specifically, these data suggest that TGF beta 1 and TGF beta 3 may play a more important role in leiomyomata growth than TGF beta 2, which leads us to propose that lowering TGF beta and receptor expression may have a direct effect on leiomyomata regression.

Interleukin-10 inhibits tumor metastasis through an NK cell-dependent mechanism

Interleukin-10 (IL-10) is a recently described pleiotropic cytokine secreted mainly by type 2 helper T cells. Previous studies have shown that IL-10 suppresses cytokine expression by natural killer (NK) and type 1 T cells, thus down-regulating cell-mediated immunity and stimulating humoral responses. We here report that injected IL-10 protein is an efficient inhibitor of tumor metastasis in experimental (B16-F10) and spontaneous (M27 and Lox human melanoma) metastasis models in vivo at doses that do not have toxic effects on normal or cancer cells. Histological characterization after IL-10 treatment confirmed the absence of CD8+ and CD4+ T cells and macrophages at the sites of tumor growth, but abundant NK cells were localized at these sites. This unexpected finding was confirmed by showing that IL-10 inhibits most B16-F10 and Lox metastases in mice deficient in T or B cells (SCID and nu/nu mice), but not in those deficient in NK cells (beige mice or NK cell-depleted mice). However, IL-10 downregulation of pro-inflammatory cytokine production and/or recruitment of additional effector cells may also be involved in the anti-tumor effect at higher local concentrations of IL-10, since transfected B16 tumor cells expressing high amounts of IL-10 were rejected by normal, nu/nu, or SCID mice at the primary tumor stage, and there was still a 33% inhibition of tumor metastasis in beige mice.

Exercise capacity in heart failure patients: relative importance of heart and skeletal muscle

The knee extensor and the whole-body exercise capacities were measured in 11 chronic heart failure (CHF) patients and 11 healthy age- and sex-matched controls, and were related to ejection fraction and to biochemical and histochemical markers of the musculature. The CHF patients had a 39% lower maximal oxygen uptake measured on an ergometer cycle than the healthy controls (1.54 +/- 0.57 vs. 2.51 +/- 0.70 1 min-1, P < 0.001). The low exercise capacity was markedly related to the ejection fraction (r = 0.77, P < 0.001). The maximal strength of m. quadriceps femoris was 15% lower in the CHF patients than in the controls (P < 0.05). The cross-sectional area (CSA) of m. quadriceps femoris explained 55% (r = 0.74, P < 0.001) of the difference in strength between both groups. The endurance capacity of m. quadriceps femoris was 30% lower in CHF patients than in controls, partly as a result of the 25% lower capillary density (P < 0.05) and the 27% lower aerobic enzyme capacity (P < 0.05), as estimated by the citrate synthase activity, in the CHF patients. The citrate synthase activity correlated with the maximal oxygen uptake (r = 0.61, P < 0.05). Moreover, the ejection fraction, together with the CSA of m. quadriceps femoris, explained 75% (r = 0.86%, P < 0.01) of the difference in maximal oxygen uptake between CHF patients and controls. These results demonstrate that CHF patients have both a lower local and a lower whole-body work capacity than healthy controls. This is a function of a smaller leg muscle mass and a lower capillary density and mitochondrial enzyme capacity in the CHF patients; however, a lowered pump capacity of the heart is the factor which limits the exercise capacity the most.

Circulating monomer-like calcitonin in osteoporotic patients

Physiological concentrations of monomeric calcitonin can inhibit osteoclastic bone resorption in vitro. We therefore investigated the circulating molecular forms, including monomer-like calcitonin, and their concentrations in 9 men and 9 women with established osteoporosis. Calcitonin was immunoextracted from serum by the use of rabbit calcitonin antibodies coupled to Sepharose 4B. The lyophilized extracts were incubated with 6 M urea overnight and gel chromatographed in a fast protein liquid chromatography (FPLC) system; calcitonin was measured by radioimmunoassay in the fractions. FPLC disclosed immunoreactive calcitonin of three different molecular sizes in the patients. The two largest forms were approximately 30 and 10 kDa and one eluted at the same position as monomeric calcitonin (3.4 kDa). After extraction and FPLC we found slightly higher calcitonin concentrations in osteoporotic women than previously reported levels in age-matched healthy women. Male patients had higher levels than female patients. None of the osteoporotic patients lacked monomer-like calcitonin. There was no significant correlation between the extracted total or monomer-like calcitonin and bone mineral density of the femoral neck. It is concluded that the circulating calcitonin in both male and female patients comprises three different molecular forms and that there is no deficiency of the monomer-like form. The calcitonin levels in the female patients were slightly higher than in a previous control group.

Expression and selective cellular localization of granulocyte-macrophage colony-stimulating factor (GM-CSF) and GM-CSF alpha and beta receptor messenger ribonucleic acid and protein in human ovarian tissue

Reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemical observations revealed that human ovarian tissue expressed granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as GM-CSF alpha and beta receptor (R) mRNA and protein. The RT-PCR products revealed the predicted 286-, 546-, and 380-bp fragments for GM-CSF, GM-CSF alpha R, and GM-CSF beta R, respectively, which were further verified by restriction enzyme digestion analysis. In situ hybridization revealed that the theca interna of the large follicles and luteal cells are the exclusive site of GM-CSF mRNA expression. Furthermore, immunohistochemical studies using specific monoclonal antibodies indicated that the theca interna of the large follicles are the exclusive site of GM-CSF protein, whereas theca externa and to a lesser extent the granulosa cells are the major sites of GM-CSF alpha R and beta R proteins. Atretic follicles and follicular cysts showed very low or no detectable levels of GM-CSF and GM-CSF alpha R and beta R. In the luteal tissue, both the small and large luteal cells of early luteal (Days 14-19) and midluteal (Days 20-25) phase expressed GM-CSF mRNA and protein as well as GM-CSF alpha R and beta R proteins, and their immunostaining intensity was similar to that seen with theca cells. Luteal cells from late luteal phase (Days 26-28), corpus albicans, and ectopic pregnancy expressed a low level of GM-CSF, GM-CSF alpha R, and GM-CSF beta R mRNA and protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of recombinant extracellular domain of human interleukin-10 receptor

The extracellular region of the human interleukin-10 (hIL-10) receptor was expressed using a myeloma cell line and was purified to homogeneity by ligand-affinity chromatography. SDS-polyacrylamide gel electrophoresis analysis indicated that the soluble receptor is glycosylated and has an apparent molecular mass of 35,000-45,000. Under native conditions, soluble hIL-10 receptor was determined by gel filtration to be a monomeric protein. Soluble hIL-10 receptor was able to inhibit the binding of 125I-hIL-10 to the full-length receptor and was able to antagonize the effect of human IL-10 in cell proliferation and cytokine synthesis inhibition. The apparent dissociation constant (Kd) of soluble hIL-10 receptor was determined to be 563 +/- 59 pM, approximately 2- to 10-fold higher than that found on intact cells (Tan, J. C., Indelicato, S. R., Narula, S. K., Zavodny, P. J., and Chou, C.-C. (1993) J. Biol. Chem. 268, 21053-21059; Liu, Y., Wei, S. H.-Y., Ho, A. S.-Y., de Waal Malefyt, R., and Moore, K. W. (1994) J. Immunol. 152, 1821-1829). When hIL-10 binds soluble hIL-10 receptor in solution, a single complex was detected by gel filtration, and the complex was found to consist of two hIL-10 dimers and four soluble receptor monomers, suggesting that hIL-10 may induce a novel mode of oligomerization of the receptor upon binding.

Midmolecular parathyroid hormone-related peptide in serum during pregnancy, lactation and in umbilical cord blood

Indications of an important physiological role of parathyroid hormone-related peptide (PTHrP) for fetal calcium homeostasis, maternal-fetal calcium transport and reproduction have accumulated over recent years. The PTHrP concentrations were measured by an earlier developed midregion radio-immunoassay in serum from lactating healthy females and umbilical cord blood and compared with levels in age-matched non-pregnant or lactating females. The PTHrP concentrations could be measured in all samples after silica cartridge C18 extraction of 10-12 ml of serum. The concentrations were significantly higher during lactation (mean +/- SD: 0.72 +/- 0.14 pmol/l, N = 22) and in umbilical cord blood (0.85 +/- 0.18 pmol/l, N = 12) compared with healthy age-matched women (0.48 +/- 0.09 pmol/l, N = 10, p < 0.001). The molecular forms of PTHrP were also studied in an age-matched control group, in pregnant women and in umbilical cord blood by gel chromatography in a fast protein liquid chromatography system of Sep-Pak-extracted pooled serum. In all three groups we found heterogeneity of the molecular forms with two predominant peaks. The smallest fragment had a molecular weight of 4-6 kD while the largest form appeared as a high-molecular-weight molecule. In conclusion, the concentrations of midmolecule PTHrP fragments in serum are elevated during lactation and in umbilical cord blood. Because the midregion of PTHrP has unique actions, our results indicate that PTHrP may play an important physiological role for the mother and for the maternal-fetal calcium transport.

Serum calcitonin forms and concentrations in young and elderly healthy females

To further investigate the role of calcitonin (CT) in normal physiology we studied circulating forms and the secretion after "calcium clamp" in young and elderly healthy females. Heterogeneity of CT in serum was disclosed after immunoextraction, fast protein liquid chromatography, and radioimmunoassay in young (27 +/- 3 years; mean +/- SD, n = 6) and elderly females (69 +/- 6 years, n = 11). Three distinct molecular forms appeared with approximate mol wt of 30, 10, and 3-4 kDa. All young women studied had considerable amounts of circulating monomer-like CT whereas several elderly had undetectable or low levels. The influence of age on basal and calcium stimulated, immunoextracted CT in serum was also studied in young (26 +/- 4 years; mean +/- SD, n = 13) and elderly (63 +/- 6 years; n = 12) healthy females. The calcium stimulation was carried out by means of the standardized calcium clamp method, where calcium was kept on a presettled level at 1.45 mmol/liter (+/- 2%) for 60 minutes. CT was immunoextracted from serum in all series of experiments with a polyclonal antiserum directed against the mid- and carboxyterminal region of the CT molecule, and the amount of extracted CT was determined by radioimmunoassay using another polyclonal antiserum against the carboxyterminal portion. After calcium infusion, the increase in CT was significantly higher in young women than in elderly (P < 0.05). At basal conditions, the CT levels were not significantly different but slightly higher in young than in elderly females. In conclusion, several elderly women lack monomer-like calcitonin in serum in contrast to young women.(ABSTRACT TRUNCATED AT 250 WORDS)

Sensitive time-resolved fluoroimmunoassay of salmon calcitonin

A two-site assay was developed by use of the "dissociation and enhancement lanthanide fluoroimmunoassay" (DELFIA) technique for determination of salmon calcitonin (SCT) in serum after administration to osteoporotic patients. Polyclonal antibodies were produced in rabbits immunized with SCT coupled to ovalbumin. After affinity purification, the antibodies were used both as immobilized capture antibodies and as Eu-chelate-labeled signal antibodies. A sensitive assay with a detection limit of 1.1 pmol/L was achieved, and no cross-reaction with human calcitonin was observed. The intra- and interassay CVs were < 12% (n = 10) and < 15% (n = 4), respectively. Analytical recovery of SCT added to serum was 91% +/- 3% (mean +/- SD, n = 4). SCT was measurable in all the samples from eight osteoporotic patients after subcutaneous SCT administration. We conclude that this new sensitive and specific two-site DELFIA can reliably measure SCT in serum.

Sensitive time-resolved fluoroimmunoassay of salmon calcitonin

A two-site assay was developed by use of the "dissociation and enhancement lanthanide fluoroimmunoassay" (DELFIA) technique for determination of salmon calcitonin (SCT) in serum after administration to osteoporotic patients. Polyclonal antibodies were produced in rabbits immunized with SCT coupled to ovalbumin. After affinity purification, the antibodies were used both as immobilized capture antibodies and as Eu-chelate-labeled signal antibodies. A sensitive assay with a detection limit of 1.1 pmol/L was achieved, and no cross-reaction with human calcitonin was observed. The intra- and interassay CVs were &lt; 12% (n = 10) and &lt; 15% (n = 4), respectively. Analytical recovery of SCT added to serum was 91% +/- 3% (mean +/- SD, n = 4). SCT was measurable in all the samples from eight osteoporotic patients after subcutaneous SCT administration. We conclude that this new sensitive and specific two-site DELFIA can reliably measure SCT in serum.

Linkage of photoreceptor degeneration by apoptosis with inherited defect in phototransduction

PURPOSE

To investigate the developing retina of normal and rd/rd mice to establish if the inherited defect in the retinal degeneration (rd) gene, encoding the beta subunit of the cascade phosphodiesterase, is associated with rd photoreceptor degeneration by apoptosis.

METHODS

DNA content of developing normal and rd/rd retinas was measured spectrophotometrically and analyzed for differential loss during the course of photoreceptor degeneration. Degenerating rd photoreceptors were evaluated by electron microscopy for cytoplasmic features and chromosomal condensation. DNA fragmentation was analyzed by agarose gel electrophoresis at daily intervals during the developmental period in which rd/rd cell death occurs.

RESULTS

DNA loss from developing rd/rd retinas is maximal between 10 and 15 postnatal days. Photoreceptor cells die individually throughout the postnatal period of degeneration, with pycnotic nuclei dispersed among morphologically normal rd photoreceptors. DNA fragmentation into 200 base pair multiples occurs maximally in rd/rd retinas between 10 and 15 postnatal days.

CONCLUSION

Photoreceptor cell death in developing rd/rd retinas occurs by a mechanism that links a defect in the phototransduction cascade with a program for cell death, called apoptosis.

Increased EGF binding and EGFR mRNA expression in rat aorta with chronic administration of pressor angiotensin II

This study examines the changes in the mRNA expression of epidermal growth factor (EGF), EGF receptor (EGFR), platelet derived growth factor (PDGF-B), and transforming growth factor beta (TGF-beta 1) before and after sustained pressor infusion of angiotensin II (Ang II) for 4 weeks. A threefold increase occurred in the levels of EGFR mRNA (17,240 +/- 827 vs 6403 +/- 1372 units, P less than 0.01) and TGF-beta 1 mRNA (1644 +/- 584 vs 475 +/- 30 units, P less than 0.01) only in the aorta and not in the heart and kidney tissues. This increase in both of the above mRNA transcripts highly correlated (r = 0.96 and 0.92, P less than 0.01) with the elevation of blood pressure. The specific binding of 125I-labeled EGF to aortic membranes also increased (11,429 +/- 728 vs 8630 +/- 420 cpm/mg protein, P less than 0.05) with a parallel increase in the protein tyrosine kinase activity of the membranes indicating that the enhanced EGFR mRNA expression resulted in increased activity of a functional receptor. No significant changes were observed in either EGF mRNA or PDGF-B mRNA levels. These findings suggest that EGFR and TGF-beta 1 participate in the long-term progressive pressor response to Ang II and thus potentially in the progression and the maintenance of chronic hypertension.