Anti-müllerian hormone in early human development

Anti-müllerian hormone (AMH) is a glycoprotein produced by immature Sertoli cells and responsible for the regression of müllerian ducts in male fetuses. The ontogeny of the hormone in early human development was investigated. While no detectable AMH could be found in female fetal serum, in males, the mean +/- S.E.M. AMH serum concentration was 40.5 +/- 3.9 ng/ml from 19 to 30 weeks (n = 13), and 28.4 +/- 6.1 ng/ml from 30 weeks to term (n = 9). The latter value is significantly different from the mean AMH concentration in serum from boys aged 2 months to 2 years (43.1 +/- 3.7), suggesting that AMH production is sluggish during the perinatal period. The serum AMH concentration of a 46,XX male fetus was in the normal range for males. Using in situ hybridization, AMH transcripts were detected in the testicular tissue of all fetuses from 8 weeks onwards, but not in fetal ovaries nor in the yet undifferentiated gonadal tissue of a 7-week-old fetus bearing male-determining DNA sequences. Together, these data indicate that AMH is a reliable marker for the presence of functional testicular tissue and, as such, may be helpful for the diagnosis of fetal sex, particularly in the presence of sex chromosome abnormalities.

Supplementary growth hormone treatment of women with poor ovarian response to exogenous gonadotrophins: changes in serum and follicular fluid insulin-like growth factor-1 (IGF-1) and IGF binding protein-3 (IGFBP-3)

The effects of supplementary growth hormone (GH) treatment upon insulin-like growth factor-1 (IGF-1), IGF binding protein-3 (IGFBP-3) concentrations in serum and ovarian follicular fluid were investigated in women undergoing buserelin human menopausal gonadotrophin (HMG) ovulation induction for in-vitro fertilization. Women (n = 40), aged 24-39 (mean 35 years), who showed poor ovarian responses to HMG, were recruited and randomly divided into two groups. Each patient received two cycles of ovulation induction, one with GH (12 IU/day x 12 days/HMG/buserelin) and another with placebo/HMG. Serum IGF-1 increased substantially during the GH treatment and remained significantly higher than the control 2 days after the last GH injection. Serum IGFBP-3 fell steadily during the placebo/HMG treatment and to a nadir on the day of oocyte retrieval (P < 0.05 compared to serum before any treatment). In contrast, IGFBP-3 was increased (P < 0.01) during the GH administration and returned to the control level 2 days after GH injection. Serum oestradiol concentrations on the eighth day of HMG and the day of human chorionic gonadotrophin (HCG) were not significantly different between the two groups. Serum IGF-1 was highly correlated with IGFBP-3 before any treatment (r = 0.433, P < 0.001). This correlation disappeared after buserelin, placebo/HMG treatment in the control group, but it was maintained during GH/HMG treatment (r = 0.343, P = 0.04). Follicular fluid concentrations of GH and IGF-1, not IGFBP-3 or oestradiol, were significantly elevated in the GH-treated women.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of human plasma growth inhibitory activity on serum-free mouse embryo cells

Serum-free mouse embryo (SFME) cells are a cell line derived in medium in which serum is replaced with growth factors and other supplements. These cells display unusual properties: a) they do not lose proliferative potential or show gross chromosomal aberration upon extended culture, b) they depend on epidermal growth factor (EGF) for survival, and c) they are reversibly growth inhibited by plasma and serum. Transfection of SFME cells with oncogenes (ras, neu, SV40 T antigen) results in cells that grow in serum-supplemented medium and no longer require EGF for survival. The growth inhibitory activity of human plasma on SFME cells was investigated. The activity was present in delipidated plasma and was not dialyzable against 1 M acetic acid. The activity precipitated in 33% methanol, bound to concanavalin A-agarose and was retarded by Sephadex G-50 in 200 mM acetic acid. A fifty- to one-hundred-fold purification was achieved, although most of the differential inhibition of untransformed vs. transformed cells was lost in the course of the purification.

Effect of growth hormone treatment on hormonal parameters, body composition and strength in athletes

The effect of recombinant GH on strength, body composition and endocrine parameters in power athletes was investigated in a controlled study. Twenty-two healthy, non-obese males (age 23.4 +/- 0.5 years; ideal body weight 122 +/- 3.1%, body fat 10.1 +/- 1.0%; mean +/- SEM) were included. Probands were assigned in a double-blind manner to either GH treatment (0.09U (kg BW)-1 day-1 sc) or placebo for a period of six weeks. To exclude concurrent treatment with androgenic-anabolic steroids urine specimens were tested at regular intervals for these substances. Serum was assayed for GH, IGF-I, IGF-binding proteins, insulin and thyroxine before the onset of the study and at two-weekly intervals thereafter. Maximal voluntary strength of the biceps and quadriceps muscles was measured on a strength training apparatus. Fat mass and lean body mass were derived from measurements of skinfolds at ten sites with a caliper. For final evaluation only data of those 8 and 10 subjects in the two groups who completed the study were analyzed. GH, IGF-I and IGF-binding protein were in the normal range before therapy and increased significantly in the GH-treated group. Fasting insulin concentrations increased insignificantly and thyroxine levels decreased significantly in the GH-treated probands. There was no effect of GH treatment on maximal strength during concentric contraction of the biceps and quadriceps muscles. Body weight and body fat were not changed significantly during treatment. We conclude that the anabolic, lipolytic effect of GH therapy in adults depends on the degree of fat mass and GH deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

High circulating leukaemia inhibitory factor (LIF) in patients with giant cell arteritis: independent regulation of LIF and IL-6 under corticosteroid therapy

Leukaemia inhibitory factor (LIF) is a cytokine which possesses a wide range of biological activities including, like IL-6, the capacity to stimulate acute phase protein (APP) synthesis. We have developed a sensitive and specific ELISA for human LIF, and tested the circulating cytokine levels in various disease states, some of which are associated with inflammation. LIF was detected in 11/20 sera from patients with giant cell arteritis (GCA), a vasculitis syndrome affecting particularly the temporal artery, characterized by panarteritis with inflammatory cell infiltration. LIF levels were considerably elevated in some patients who also displayed elevated levels of IL-6 and C-reactive protein (CRP); however, no correlation was observed between the levels of circulating LIF and levels of IL-6 or CRP. Furthermore, LIF levels were not affected by corticosteroid therapy, whereas IL-6 and CRP decreased rapidly, as clinical symptoms resolved. A putative role for LIF in the persistence of histological lesions is discussed. This is the first report of the presence of circulating LIF in sera. These results are in agreement with the complexity of induced inflammatory cytokines and corticoid regulation of APP synthesis observed in vitro and in vivo.

Mullerian inhibiting substance: a gonadal hormone with multiple functions

Mullerian inhibiting substance (MIS) is the gonadal hormone that causes regression of the Mullerian ducts, the anlagen of the female internal reproductive structures, during male embryogenesis. MIS is a member of the large transforming growth factor-beta (TGF beta) multigene family of glycoproteins that are involved in the regulation of growth and differentiation. The proteins in this gene family are all produced as dimeric precursors and undergo posttranslational processing for activation, requiring cleavage and dissociation to release bioactive C-terminal fragments. Similarly, the 140 kilodalton (kDa) disulfide-linked homodimer of MIS is proteolytically cleaved to generate its active C-terminal fragments. The sexually dimorphic expression of MIS in Sertoli cells of the testis and granulosa cells of the ovary is critical for normal differentiation of the internal reproductive tract structures. A number of extra-Mullerian functions such as control of germ cell maturation and gonadal morphogenesis, induction of the abdominal phase of testicular descent, suppression of lung maturation, and growth inhibition of transformed cells have also been proposed for this growth-inhibitory hormone and will be discussed. This article will summarize the current understanding of the biology and multiple functions of MIS including its activation, regulation, and mechanism of action and discuss areas of interest in ongoing research.

Müllerian inhibiting substance in the diagnosis and management of intersex and gonadal abnormalities

Müllerian inhibiting substance (MIS), a gonadal hormone important in sexual differentiation, is high (10 to 70 ng/mL) in human male serum postnatally for several years before declining during the peripubertal period, but is undetectable in female serum until the onset of puberty. The sexually dimorphic secretion of MIS suggested possibilities for its use in several clinical settings. Thirty-one patients with intersex and gonadal anomalies from 17 institutions were therefore evaluated between 1989 and 1992 with an MIS enzyme-linked immunosorbent assay (ELISA). Serum MIS levels correlated with the presence of testicular tissue in two patients with suspected anorchia, five patients with male pseudohermaphroditism, and eight other intersex patients with undescended testes, dysgenetic gonads, or ovotestes. In these latter patients, serial MIS values were also helpful to confirm complete removal of gonadal tissue postoperatively. MIS may be a more sensitive marker for the presence of testicular tissue than serum testosterone levels, both before and after the neonatal androgen surge, and, consequently, may obviate the need for human chorionic gonadotropin stimulation in the evaluation of certain intersex disorders. In values were useful in differentiating the underlying etiology of the disorder. Four patients with undetectable levels have presumptive MIS gene mutations, while 7 others with MIS values of 2 to 45 ng/mL may have bioinactive hormone of MIS receptor defects. Finally, two young girls with ovarian granulosa cell tumors had elevated MIS values that fell from 18 to 2 ng/mL and from 6.5 to 1 ng/mL during postoperative follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum levels of mullerian inhibiting substance in boys throughout puberty and in the first two years of life

Serum levels of Mullerian inhibiting substance (MIS) have been measured in 91 boys throughout normal pubertal development. MIS levels fell sharply after pubertal stage 1 and were mostly undetectable at pubertal stage 6. The relationship between MIS concentration and pubertal stage was similar when compared with age. Seven patients with precocious puberty and 12 with delayed puberty were also investigated and found to have MIS levels consistent with their degree of pubertal development. Precocious puberty was associated with MIS levels that were abnormally low for age, while delayed puberty resulted in persistence of high MIS levels. Serum MIS levels were also measured in 29 boys less than 2 yr of age undergoing minor surgery. High levels were found throughout this time period, which is consistent with previous reports. MIS levels appear to be inversely related to levels of gonadotropins, steroids, and inhibin, which fall in the first 2 yr of life and rise throughout puberty.

The persistent müllerian duct syndrome: a rare cause of cryptorchidism

The persistent Müllerian duct syndrome is characterized by the retention of Müllerian derivatives in patients otherwise normally virilized. Clinically, the persistence of uterus and tubes leads either to cryptorchidism or inguinal hernia, depending on whether or not the Müllerian derivatives can be mobilized during testicular descent. The condition is usually discovered at surgery, however preoperative sonography could allow the diagnosis to be made preoperatively. The molecular basis of the persistent Müllerian duct syndrome is heterogeneous, and is reflected by wide variations in the serum concentration of anti-Müllerian hormone. Some cases are apparently due to end-organ resistance, and are associated with normal serum levels of the hormone. Others, characterized by absent or low hormone concentrations, can be explained by mutations of the gene coding for anti-Müllerian hormone, which are distributed along the whole length of the coding region.

Hypoplastic acute leukemia: description of eight cases and search for hematopoietic inhibiting activity

Hypoplastic acute leukemia (HAL) is characterized by pancytopenia and by hypocellularity of the bone marrow. The marrow contains equal to or more than 30% myeloblasts. Absence of tissue infiltrates and/or tumor masses is mandatory. Eight patients are described here. They do not fit into the FAB classification for either acute nonlymphocytic leukemia (ANLL) or myelodysplastic syndrome (MDS), except for one patient who subsequently proved to have a chronic myelomonocytic leukemia (CMML). The median age is 65 years. Two patients, including the CMML patient, are alive, 22 and 6 months from diagnosis. Six patients have died. The median survival is 8 months. Normal bone marrow cells cultured either with HAL sera or with HAL peripheral blood mononuclear cells as feeders and exogenous GM-CSF yielded subnormal CFU-GM counts. This might indicate inhibitory activity of HAL serum and defective stimulatory activity of HAL peripheral blood mononuclear cells.

Variants of the anti-Müllerian hormone gene in a compound heterozygote with the persistent Müllerian duct syndrome and his family

The persistent Müllerian duct syndrome (PMDS) is a rare form of male pseudohermaphroditism, characterized by the persistence of Müllerian derivatives in otherwise normal males. Two mutations, present in the homozygous state, have been previously described in such patients. The present observation is the first example of compound heterozygosity in this condition. DNA was obtained from a 3-month-old patient with PMDS, in whom no serum anti-Müllerian hormone (AMH) could be detected by enzyme-linked immunosorbent assay. Sequencing of cloned polymerase chain reaction amplified fragments of the AMH gene revealed a 14-bp deletion in the second exon of the maternal allele; this deletion disrupted the open reading frame. It occurred at a site containing two 8-bp direct repeats flanking a 6-bp sequence and removed one whole repeat plus all of the intervening sequence. It may be the result of a slipped mispairing at the DNA replication fork. The paternal allele contains a stop mutation in the third exon. These two mutations, impairing both AMH alleles, are consistent with the occurrence of PMDS, and are shared with a phenotypically normal younger sister. In this family, various other mutations, devoid of physiological significance, suggest that the AMH gene is highly polymorphic.

Purification and partial characterization of two types of growth-inhibitory protein latently present in rabbit serum

Normal rabbit serum contained two kinds of growth-inhibitory protein, GI-I and GI-II, in latent forms. These latent inhibitors were activated by incubation at 37 degrees C for 12 h, and their activation was lowered by inhibitors for serine, cysteine and metalloproteinases. Both growth inhibitors were highly purified in active forms by successive column chromatographies. GI-I showed a major protein band with an Mr of 18,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, while GI-II showed a major protein band with an Mr of 36,000. GI-I and GI-II half-inhibited the growth of rat tumorigenic cell line (RSV-BRL) at concentrations of 0.5 ng/ml and 10 ng/ml, excess concentrations. Of the 15 cell lines tested, GI-I specifically inhibited the growth of rodent and lagomorph cells, whereas GI-II nonspecifically inhibited the growth of all cell lines tested. Specificities for cell type and malignancy were not observed with either inhibitor. These growth inhibitors were stable to a reducing reagent and proteinase inhibitors, but labile to urea, acid, organic solvents, trypsin, plasmin and heating at 95 degrees C for 5 min. These properties suggested that both growth inhibitors might be distinct from known growth-inhibitory factors.

HILDA/LIF urinary excretion during acute kidney rejection

Recently, a new lymphokine called HILDA (human interleukin for DA cells) has been described and cloned. This cytokine, initially described to be produced by alloreactive T lymphocyte clones grown from a rejected human kidney allograft, is identical to other factors termed D-factor, differentiation-inducing factor, differentiation inhibitory activity, hepatocyte-stimulating factor III, and leukemia inhibitory factor. HILDA/LIF induces various effects on neural, hemopoietic, embryonic cells as well as on bone remodeling and acute phase protein synthesis in hepatocyte. In this study we demonstrate the presence of HILDA/LIF in the urine but not in the serum of kidney graft recipients during acute rejection episodes, whereas this lymphokine was detectable neither in the serum nor in the urine of kidney transplanted patients with stable renal function. These data reinforce the notion of a possible role for this lymphokine in the inflammatory and/or the immune response.

The existence of activin A/erythroid differentiation factor and its inhibitor in human serum: comparison of normal and chronic renal failure sera

Activin A/EDF, initially found as a differentiation inducer of murine Friend erythroleukemia, also has a stimulatory effect on erythropoiesis in vitro and in vivo. Here we proved activin A/EDF activity in human serum. The activin A/EDF level in 18 normal human serum samples was measured by a specific bioassay and was found to be 8.3 +/- 4.6 ng/ml, indicating that there exists sufficient activity to affect erythropoiesis in normal serum. In contrast, activin A/EDF activity was reduced in the chronic renal failure patients and 23/26 serum samples examined showed levels below 1.2 ng/ml. Further analysis using HPLC revealed that chronic renal failure serum actually contained as much activin A/EDF as normal serum, and that the difference between normal and patient serum existed in the content of a specific inhibitor of activin A/EDF. This observation suggests the possibility that the inhibitor is participating in the regulation of activin A/EDF activity in vivo in chronic renal failure patients and also the possibility of activin A/EDF could be utilized in the therapy of the anemia of such patients.

Analysis of regulation of T-cell responses by soluble inhibitory factors from the sera of patients with Hodgkin's disease

Soluble inhibitory factors (SIF) have been demonstrated in the sera of cancer patients, which interfere with the T-cell activation process. We have shown that the major contributory factor to the inhibitory effect of sera from patients with Hodgkin's disease (HD) could be the soluble form of Interleukin-2 receptors (sIL-2R). The parameters studied to show the presence of SIF include (i) inhibiton of mitogen-induced proliferation; (ii) status of high- and low-affinity IL-2R; and (iii) internalization of IL-2-IL-2R complex, by lymphocytes from healthy donors activated with mitogen in presence of HD sera. Parameters studied to show the inhibitory role of sIL2R include (i) quantitation of sIL-2R in HD sera; (ii) effect of high-sIL-2R-containing sera on mitogen-induced proliferation and detection of IL-2 in activated lymphocyte culture supernatants; (iii) effect of exogenous IL-2 supplementation; and (iv) abrogation of inhibitory activity of sIL-2R-containing sera after passing them through IL-2 affinity columns. Our results show that 6/23 HD sera tested had high inhibitory activity (greater than 50% inhibition of mitogen-induced proliferation). The SIF did not affect expression of high- and low-affinity IL-2 receptors, or internalization of the complex by activated lymphocytes. Ten of the 15 sera tested showed significantly high levels of sIL-2R. Pooled sera with high sIL-2R content inhibited mitogen-induced proliferation of normal lymphocytes with a concomitant reduction in IL-2 activity in the lymphocyte culture supernatants. When supplemented with exogenous IL-2, there was a partial recovery of the inhibitory effect. When sIL-2R containing serum pool was passed on IL-2 affinity columns, the inhibitory effect was reduced. The eluted "sIL-2R" adsorbed on the IL-2 column showed anti-proliferative effect.

Uremic inhibitors of erythropoiesis: a study during treatment with recombinant human erythropoietin

The effects of increasing amounts of uremic sera (US) on the growth of erythroid progenitor cells [burst-forming unit erythroid (BFU-E)] collected from peripheral blood of normal subjects were evaluated to assess the potential role of uremic inhibitors of erythropoiesis during a treatment with recombinant human erythropoietin (r-HuEpo). US were collected from 8 patients on regular dialysis with marked anemia (Hb 6 +/- 0.5 g%) before and after a treatment with high doses of r-HuEpo (from 300 to 525 U/kg/week). Standard cultures for BFU-E were performed in alpha-metylcellulose with fetal calf serum (FCS) and 4 U/ml of r-HuEpo (Cilag, Ortho). In successive cultures, US were added at increasing amounts to the standard culture in order to assess a possible inhibitory effect on BFU-E growth. Finally, in order to assess a possible lack of stimulatory factors, we partially substituted FCS with US. The addition of US collected either before or after therapy with r-HuEpo to the standard culture had no effect on the growth of BFU-E. Vice versa, the number of cultured BFU-E decreased when FCS was partially substituted with US collected before r-HuEpo. This effect was not evident when FCS was partially substituted with US collected after r-HuEpo. No significant differences were recorded in the tested sera collected before and after therapy considering erythropoietin levels and amino acid levels. We hypothesized that some other factors with erythropoietic stimulatory activity (burst-promoting activity?) may be deficient in uremic patients with marked anemia and can be induced during therapy with r-HuEpo.

Purification and properties of growth inhibitor from normal rabbit serum

It was previously found that rabbit serum contains a growth-inhibitory substance for a tumorigenic rat liver cell line RSV-BRL. In the present study, the growth inhibitor was purified from normal rabbit serum to show a homogeneous protein band with a molecular weight (Mr) of 56 k on SDS-polyacrylamide gel electrophoresis under non-reducing conditions. The purified growth inhibitor, tentatively named rabbit serum-derived growth inhibitor (RSGI), potently inhibited the growth of RSV-BRL and nine kinds of other cell lines including three human tumor cell lines at a concentration of 20 ng/ml or higher. The growth-inhibitory effect of RSGI was reversible and appeared to be cytostatic rather than cytotoxic. RSGI was stable to heating at 56 degrees C for 30 min or treatment with 0.1 M 2-mercaptoethanol, but labile to heating at 100 degrees C for 3 min or treatment with 1 M acetic acid (pH 2.3), 6 M urea, 50% (v/v) 1-propanol, or 0.1% (w/v) trypsin. These properties of RSGI suggested that it was different from type beta transforming growth factors, tumor necrosis factor-alpha, and other known growth-regulatory factors.

Biochemical analysis of a human humoral fibroblast inhibitory factor associated with impaired vascular prosthetic graft incorporation

A specific inhibitory factor was isolated from human serum of a patient who manifested impaired prosthetic graft tissue incorporation. The latter reaction was hypothesized to be related to inhibiting fibroblast proliferation by a specific humoral factor. The crude inhibitory serum was tested against a pool of normal human sera with different cell types in culture. Proliferation of human skin fibroblast and human smooth muscle cell cultures incubated in the presence of 50% inhibitory serum were inhibited up to 58% and 37%, respectively. Proliferation of bovine capillary endothelial cell cultures was stimulated under similar conditions. Isolation and purification of the inhibitory factor from crude serum were initiated by ammonium sulfate precipitation. The pellet was further fractionated by sepharose 6B gel filtration. The inhibitory activity was eluted from the column in a relatively purified form as indicated by gel electrophoresis of the inhibitory fractions, which demonstrated a specific band corresponding to the inhibitory protein, with an apparent relative molecular mass of 230 kDa. The inhibitory factor showed a high affinity to concanavalin A, indicating its nature as a glycoprotein not associated with albumin or immunoglobulin fractions of the serum.

Characterization of a novel erythropoiesis-inhibiting human protein

We have isolated an erythropoiesis-inhibiting protein, DIP (differentiation-inhibiting protein), from the blood of a 60-year-old woman suffering from pure red cell aplasia. This protein inhibits the growth and differentiation of normal human and murine BFU-E, but not CFU-E, cells as well as dimethyl sulfoxide-induced hemoglobin synthesis by Friend murine erythroleukemia cells. It appears that DIP primarily affects differentiation rather than proliferation, because it does not inhibit the proliferation of untreated Friend erythroleukemia cells. DIP seems to function like a recently described 45-kDa autocrine differentiation-inhibiting protein factor (ADIF) which is secreted by tsAEV-transformed chicken erythroleukemia cells. Both proteins selectively block the differentiation of normal human and murine BFU-E cells as well as the differentiation (but not the proliferation) of Friend murine erythroleukemia cells. However, the human DIP is not an autocrine product of the patient's bone marrow cells, nor does it affect chicken erythroid cells.

Isolation and characterization of three inhibitors of thymidine incorporation into bovine fetal liver cells

During the isolation and purification of erythroid cell-stimulating factors from fetal tissues and blood, we found that they were almost invariably contaminated with substances that inhibited thymidine incorporation into erythroid cells of fetal bovine liver. We have isolated and partially sequenced three of these inhibitory factors. The first one was a 46-kDa heparin-binding protein from fetal bovine serum with 80% sequence identity with human apolipoprotein H (apo H). Although human apo H had no inhibitory activity on thymidine incorporation, the bovine apo H-like protein inhibited thymidine incorporation with an ID50 of 36 nM. It probably belongs to a group of heparin-binding apolipoproteins such as apo B and E, which have been reported to inhibit hematopoietic cells. The second inhibitor isolated from fetal bovine serum was clearly cytotoxic at a concentration of 1 nM. This 11-kDa peptide seems to be structurally related to the anaphylatoxins. The third inhibitor was isolated from human fetal intestine. The amino-terminal sequence of this protein was nearly identical to the amino-terminal sequence of human phospholipase A2 isolated from pancreas or lung. Bovine liver erythroid cell membranes are particularly sensitive to phospholipases. Since the synthesis and secretion of phospholipase A2 has been reported to be under the control of interleukin-1 or tumor necrosis factor in different cells, it is possible that this enzyme may be secreted locally and play an important role in tissue remodeling during injury or fetal development.

Serum levels of Mullerian inhibiting substance in boys with cryptorchidism

Serum levels of Mullerian inhibiting substance (MIS) were measured in boys with cryptorchidism (n = 104) and paired, age-matched controls (n = 104) using an enzyme immunoassay. Control MIS levels were high during the first year of life with a peak level at 4 to 12 months, subsequently diminishing with age. MIS levels in patients with undescended testes also declined with age, although a surge was not found in the first year. Mean MIS concentration of cryptorchid boys was significantly lower than controls (P less than .001). There was a significant reduction of the mean MIS level in children with bilateral cryptorchidism compared with those with unilateral undescended testis (P less than .05). These differences might support the hypothesis that MIS initiates transabdominal testicular descent. However, because most undescended testes are probably the result of anatomical or functional abnormalities during transinguinal testicular descent, differences in MIS levels more likely result from secondary testicular degeneration. In the future, MIS immunoassay should play an important role in the investigation of gonadal function in boys with various genital disorders, including cryptorchidism.

Serum inhibition of proliferation of serum-free mouse embryo cells

Serum-free mouse embryo (SFME) cells, derived in medium supplemented with insulin, transferrin, high density lipoprotein, epidermal growth factor, and fibronectin, do not undergo crisis, maintain a predominantly diploid karyotype with no detectable chromosomal abnormalities for well over 100 population doublings in vitro, and are growth inhibited by concentrations of serum that are growth-stimulatory for most cell lines in culture. Serum inhibition of SFME cell proliferation was reversible and was not prevented by addition of the supplements of the serum-free medium, even when added repeatedly during the culture period. The serum effect on SFME cell proliferation could be detected after incubation in serum-containing medium for as little as 8 h. SFME cells in serum-containing medium were arrested in the G1 phase of the cell cycle with a greatly reduced rate of incorporation of precursors into DNA and thymidine kinase activity, while a reduction in rate of incorporation of amino acids into protein was not observed. SFME cultures maintained for extended periods in serum-containing medium underwent a crisis-like period followed by the appearance of variant cells capable of growing in serum-supplemented medium. These cells exhibited abnormal karyotype and were resistant to several inhibitors of proliferation active on the parent SFME cell type.

The so-called interleukin-2 inhibitory activity of human serum is largely cytotoxic to mouse cells

No specific interleukin-2 (IL-2) inhibitor has ever been demonstrated in human, mouse, or any other animal serum. Native mouse serum contains activities which completely inhibit IL-2-dependent and IL-2-independent in vitro proliferation of cells of different animal species by a non-cytotoxic mechanism. The decisive inhibitory component of mouse serum has a molecular weight of about 80,000, is heat-labile and has not been found in other animal sera. Also, native human serum completely suppresses the proliferation of various mouse cell types, predominantly by a cytotoxic effect caused by natural IgM antibodies and complement. Heat-inactivated human serum is no longer cytotoxic to mouse cells, and inhibits the proliferation of mouse cells much less than native serum. There is thus no evidence for a specific IL-2 inhibitor in mouse, human or other serum.

[Characterization of tumor cell growth inhibitor present in rabbit serum]

Growth inhibitors present in various kinds of sera were surveyed using the rat liver epithelial cell line BRL and its tumorigenic transformant RSV-BRL as indicator cells. This survey revealed that normal rabbit serum contained two types of growth inhibitors: one (GI-A) was more growth-inhibitory on RSV-BRL than BRL, whereas the other (GI-B) vice versa. GI-A was purified 3,000-fold to show a major protein band with Mr 70k on SDS-PAGE. It was an acid-and heat-labile protein and potently inhibited the growth of three kinds of transformed cell lines and two human carcinoma cell lines, but hardly that of non-transformed cell lines, at a dose of 0.5-1.0 micrograms/ml. On the other hand, GI-B was an acid- and heat-stable protein with Mr 25k and was considered to belong to the TGF-beta family.

Sex-specific fetal lung development and müllerian inhibiting substance

Male neonates develop respiratory distress syndrome (RDS) with a greater incidence and mortality than do female neonates; the cause of this male disadvantage remains obscure. Male fetuses are exposed to higher levels of androgens and Müllerian inhibiting substance (MIS). Androgens have been shown to inhibit fetal lung maturation, and recent evidence in vitro indicates that MIS, a Sertoli cell-derived glycoprotein made early in ontogeny of the testis, may also inhibit lung development. To study whether this fetal regressor might inhibit maturation of the fetal lung in vivo, we injected human recombinant MIS (rMIS) into fetal rats, measured serum levels of rMIS using an enzyme-linked immunosorbent assay, and analyzed fetal lung tissue histologically and for protein, glycogen, DNA, and disaturated phosphatidylcholine content. Peak serum levels of recombinant MIS were measured at 6 h, with an apparent elimination half-life of 3 h, and without leakage into adjacent littermates injected with vehicle alone. Female fetal rat lung tissue exposed to recombinant MIS (10(-9) M, 10(-8) M) revealed depressed disaturated phosphatidylcholine content both 48 and 72 h after injection compared with female vehicle-injected littermates. Male lungs of the same gestational age appeared inhibited at a higher (10(-8) M) rMIS dose. These inhibitory effects observed in vivo confirm those previously seen in vitro and suggest that MIS, as well as androgens, may play a causative or important ancillary role in the sexual dimorphism that characterizes the neonatal respiratory distress syndrome.

An enzyme linked immunoassay for anti-müllerian hormone: a new tool for the evaluation of testicular function in infants and children

Anti-Müllerian hormone (AMH), also called Müllerian-inhibiting substance or factor was measured by an interspecific enzyme-linked immunoassay in the serum of 218 normal children and adults of both sexes and in 110 boys with various developmental disorders. AMH levels were high [81.67 ng/ml +/- 7.44(SEM)] in normal males under 2 yr of age, fell progressively in older boys and, decreased sharply at puberty. Serum AMH was not detectable in adults or in females at any age, with very rare exceptions. AMH serum concentrations were significantly decreased in infants with disorders of sex differentiation, particularly testicular dysgenesis, and increased in patients with delayed puberty. In contrast, levels were not significantly affected by either cryptorchidism or chorionic gonadotropin stimulation. AMH shows promise as a marker of testicular function in infancy.

An immunoassay to detect human müllerian inhibiting substance in males and females during normal development

An enzyme-linked immunosorbent assay has been developed to measure human Müllerian inhibiting substance (MIS) in biological fluids. The enzyme-linked immunosorbent assay is specific for MIS, with a sensitivity in human serum to 0.5 ng/ml and does not recognize transforming growth factor-beta 1 or -beta 2, LH, or FSH. It similarly fails to recognize other proteins secreted from the cell type into which the MIS gene was cloned. MIS was detected in the serum of normal newborns, infants, children, and adults. In males the serum level of MIS is 10-70 ng/mL at birth. The level increases slightly after birth, and then decreases to a basal level of 2-5 ng/mL after the first 10 yr of life. Newborn male urine contains minimal amounts of MIS (0.5 ng/mL). In females MIS is barely detectable in serum at birth, but rises to the basal level equal to that seen in males after 10 yr of age. Similar basal levels of MIS were found in adult ovarian follicular fluid. MIS levels were high in the serum of a female patient with a sex cord tumor (3200 ng/mL), but fell to 100 ng/mL after multiple excisional operations. In addition, a serum MIS level of 20 ng/mL was detected in a patient with an ovarian granulosa cell tumor. A sensitive assay for MIS could be useful in the diagnosis of patients with congenital abnormalities of sexual development and patients with Sertoli cell and/or other MIS-producing neoplasms. Other applications may also be recognized as the biology of MIS in both males and females is further elucidated.

Serum levels of müllerian inhibiting substance in boys from birth to 18 years, as determined by enzyme immunoassay

An enzyme immunoassay was set up with the aim of determining the serum levels of Müllerian inhibiting substance (MIS) during childhood. A monoclonal antibody against purified bovine MIS was combined with a polyclonal antibody against recombinant human MIS to make a sandwich assay. This assay detected MIS in human serum within the following criteria. Ninety-eight boys, aged between birth and 18 yr, who had been admitted to the Royal Children's Hospital, were included. MIS levels were measured in samples taken for biochemical screening of unrelated disorders. MIS was detected in the serum up to 16 yr of age, but was low beyond 12 yr and undetectable at 18 yr. High MIS levels were found at 4-12 months, consistent with MIS having an important function at this time. Germ cells undergo an important transformation from gonocytes to spermatogonia at the same time as the MIS levels peak, suggesting a possible function for MIS.

Partial purification of a serum fraction from fasted pigs that inhibits proliferation of cultured myogenic cells

Sera from pigs fasted as little as 24 h appears to contain a factor(s) that inhibits proliferation of myogenic cells in culture. An inhibitor of myogenic cell proliferation has been partially purified from this sera by using a combination of gel filtration and immunoaffinity chromatography. The inhibitory activity elutes from a Sephacryl S-300 column at a Kav (elution minus void volume divided by total minus void column volume) between .41 and .59. Proteins banding at 76 and 67 kilodaltons appear to predominate on sodium dodecyl sulfate polyacrylamide gels of this fraction. Small quantities of each of these proteins were electrophoretically purified and used to elicit production of anti-76 and anti-67 immunoglobulin G in rabbits. These antibodies were used to prepare anti-76 and anti-67 column was particularly useful in isolating the inhibitor because it removed mitogens that made detection of the inhibitory activity difficult. The partially purified inhibitor inhibits proliferation of L6 myogenic cells in a concentration-dependent manner. On sodium dodecyl sulfate polyacrylamide gels, the predominant proteins in the inhibitor fraction band at approximately 63 and 61 kilodaltons. Inhibitors of myogenic cell proliferation may play an important role in balancing the effects of positive growth factors.

Inhibitor of granulocyte-macrophage colony formation in plasma of mice rendered aplastic by allogeneic lymph node cells

Sublethally irradiated CBA/J mice injected with lymph node cells (LNC) of C3H/He mice exhibit aplastic anemia within 3 weeks. Aplastic anemia plasma (AAP) from these mice was found to inhibit granulocyte-macrophage colony (GM-CFU) formation. This inhibitory action was not strain specific and was not generated in donor:host combination involving other strains. AAP also inhibited the formation of colonies derived from leukemic cell lines. Though this activity inhibited GM-CFU, it did not affect erythroid colony formation. Two experiments were performed to examine the mechanism of inhibition. Superoptimal concentrations of recombinant mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) did not reverse AAP-induced inhibition of colony formation. Bone marrow cells preincubated with AAP for 24 h and washed were unchanged in their ability to form GM-CFU colonies. Thus, the inhibitory activity acted neither as a competitive nor a cytotoxic agent. Interferons and certain prostaglandins, known to inhibit colony formation, were not found in active concentrations in AAP. The inhibitory activity of AAP was heat stable, nondialyzable, inextractable with chloroform, precipitable with 50% ammonium sulfate, and had a molecular weight of 100,000 daltons. In contrast, control plasma from mice given only sublethal irradiation and injected with saline had significantly less inhibitory activity, which was not heat stable and was extractable with chloroform. Thus, LNC in certain host mouse strains generate a plasma activity that can inhibit the formation of normal and leukemic GM-CFU colonies.

Growth-inhibitory protein present in rabbit serum, which is more effective on tumorigenic rat liver epithelial cells than on non-tumorigenic ones: its species, and mode of existence

We have previously reported that in culture, rabbit serum inhibits the growth of the epithelial cell line from Buffalo rat liver (BRL) lower than that of the tumorigenic one transformed by Rous sarcoma virus (RSV-BRL). Here, the serum was fractionated by several different methods. The findings are: 1) the growth inhibitor present (GI) existed as large complexes with non-inhibitory proteins; 2) the complexes were dissociated by 1 M NaCl plus 6 M urea; 3) the dissociated GI did not pass through membrane filter with Mr cutoff 10k; 4) it was stable in 8.5 M urea and 1 M acetic acid (pH 2.5), but labile against either dithiothreitol and trypsin; 5) it was separable into two species with pI 7.5 and 9.5; 6) both species were more effective on RSV-BRL than on BRL.

Selective inhibition of erythropoiesis by sera from patients with chronic renal failure

The pathogenesis of anemia in patients with chronic renal failure was studied by analyzing the effect of uremic sera on the in vitro colony growth of erythroid (CFU-E) and granulocyte-macrophage (CFU-GM) progenitor cells. Uremic sera from 20 of 30 patients inhibited erythroid colony growth below 70% of control even when cultured with normal human bone marrow of the same blood type. On the other hand, only one of the sera inhibited colony growth of CFU-GM as compared with normal sera. On Sephadex G-15 gel filtration, the CFU-E-inhibiting activity appeared in two different fractions: the void volume peak and the delayed eluant before the second peak. The inhibiting activity in the former fraction was noted only in uremic sera. The results of this study suggest the existence of a serum inhibitor(s) of erythropoiesis with a relative molecular mass of more than 1500 Da which are virtually impossible to dialyze by conventional membranes.

Growth inhibitors in serum, platelets, and normal and malignant tissues

The non-malignant epithelial cell line from Buffalo rat liver (BRL) and its malignant transformant obtained by Rous sarcoma virus infection (RSV-BRL) were used as the indicators. A survey was made in animals for growth inhibitors which could inhibit the growth of BRL, but not the growth of RSV-BRL in culture, under the consideration that the loss of the sensitivity to such inhibitors might be the most dominant cause for acquisition of tumorigenicity. From human platelets, a growth inhibitor was extracted with acid-ethanol and prepared to a homogeneous purity, separated from the major TGF-beta activity, which stimulated the anchorage-independent growth of NRK cells in the presence of EGF. The purified inhibitor (Mr 25-27k; pI 8.7-9.1) showed 50% inhibition on the growth of BRL at 20 pg/ml (0.7 pM), but hardly influenced the growth of RSV-BRL. Its inhibition was specific to epithelial cell lines, thus called epithelial growth inhibitor (EGI). It consisted of two subunits with practically identical Mr, which were cross-linked with disulfide bonds. Its sequence of N-terminal 10 amino acids was consistent with that of TGF-beta. In rats, serum contained a growth inhibitor with Mm 220k. The inhibitor, when treated with high concentrations of urea or guanidine-HCl, liberated an active component with Mr 30k and pI 5.2. When the growth inhibitor with Mm 220k was treated with ethanol-acetone or 1 M acetic acid, its activity increased more than 10-fold. Growth inhibitors were extracted with acid-ethanol from various tissues of rats. The activities of the extracts to inhibit the growth of BRL cells were high in spleen, lung and tumors with relatively high mitotic activities, but low in muscle, heart and brain. Acid-ethanol extract from BRL cells showed growth inhibitory activity toward BRL cells themselves significantly higher than that from RSV-BRL cells. The serum-free media conditioned with BRL and RSV-BRL cells showed a little growth inhibitory activity toward BRL cells. On treatment with acetic acid, their activities increased significantly, comparable for both types of cells. The media thus activated inhibited the growth of BRL cells, but not that of RSV-BRL cells. All the growth inhibitors described above including human platelet inhibitor, whether present in extracts or purified, resembled one another in stability against acid, heat and reducing reagents.

Purification and properties of epithelial growth inhibitor (EGI) from human platelets: its separation from type beta transforming growth factor (TGF-beta)

We previously reported that sera from various kinds of animals contain a protein(s) capable of inhibiting the growth of the non-malignant epithelial cell line derived from Buffalo rat liver (BRL). In the present study, a similar epithelial cell-specific growth inhibitor (EGI) was purified to homogeneity from an acid-ethanol extract of human platelets. During purification, EGI was separated from the major component of type beta transforming growth factor (TGF-beta), which can stimulate the colony formation of the non-malignant fibroblastic cell line derived from rat kidney (NRK) in soft agar in the presence of epidermal growth factor (EGF). The purified EGI had an Mr of 27,000, and was composed of two subunits identical in Mr. It significantly inhibited the growth in monolayer cultures of three non-malignant epithelial cell lines, BRL, MDCK (from Madin-Darby canine kidney) and BSC-1 (from African green monkey kidney), at doses lower than 40 pg/ml in medium containing 10% fetal calf serum. Its inhibitory activity was stable against heating at 90 degrees C for 3 min, but not against treatment with 50 mM dithiothreitol. In addition, TGF-beta was also partially purified from the same extract. The purified TGF-beta did not show any inhibitory activity toward the growth of BRL, MDCK, BSC-1, or NRK.

Two types of growth inhibitor in rat platelets for primary cultured rat hepatocytes

Rat platelets contain two types of growth inhibitor of adult rat hepatocytes in primary culture. One, named platelet derived growth inhibitor (PDGI)-alpha, is a heat- and acid-labile protein with a molecular weight of over 200 KD that is not released on thrombin treatment. The other, named PDGI-beta, is a heat- and acid-stable factor with a molecular weight of 24 KD that is released by thrombin. Both PDGI-alpha and -beta were inactivated by treatment with dithiothreitol. They both caused dose-dependent inhibition of DNA synthesis stimulated by insulin plus epidermal growth factor. These inhibitions were closely correlated with marked decrease in the labeling index. Neither PDGI-alpha nor -beta had a cytotoxic effect as judged by phase-contrast microscopic examination of the cells nor inhibition of protein synthesis. The properties of PDGI-beta suggest that it may be identical with transforming growth factor-beta. These results indicate that rat platelets contain not only a growth factor (HGF), but also growth inhibitors that affect adult rat hepatocytes.

[Nature of the chalone fraction of erythrocyte extracts]

The chalone fraction of erythrocyte extracts is immunologically identical to albumin and not identical to hemoglobin. It differs from albumin and hemoglobin in biological properties and electrophoretic mobility. The immune antichalone serum permits evaluating erythropoiesis in posttransfusion polycythemia and acute blood loss.

Aplastic anemia occurring as amegakaryocytic thrombocytopenia with and without an inhibitor of granulopoiesis

Two patients with aplastic anemia evolving from cellular bone marrows with severely diminished megakaryocytes are reported. During this evolution a plasma inhibitor of in vitro granulocyte-macrophage colony formation was demonstrated associated with non-A, non-B hepatitis in one patient. The second patient had abnormal liver function that corrected after the delivery of a normal newborn but there was persistence of pancytopenia without evidence of a plasma inhibitor.

Dual functions of DNA synthesis inhibitory peptide in fetal calf serum

A novel factor in fetal calf serum was found which showed the dual inhibitory effects on DNA synthesis of murine lymphocytes and some species of bacteria. The factor was purified by gel filtration, ion exchange and thin-layer chromatography and characterized to be a 1 kDa basic peptide. In addition, this factor is not nonspecific to inhibitors, thymidine or polyamines. The modes of action and the spectrum of target cells were analyzed and its biological significance is discussed.

Characterization of a growth-inhibiting protein present in rat serum that exerts a differential effect on in vitro growth of nonmalignant rat liver cells when compared with Rous sarcoma virus-transformed rat liver cells

We have previously reported the transformation by Rous sarcoma virus of a cloned epithelial cell line (BRL) established from Buffalo rat liver by H. Coon. The nontransformed (BRL) and transformed (RSV-BRL) cells grew at comparable rates in culture, whereas only the transformed cells were tumorigenic in vivo. We report here on the existence in rat and mouse sera of a growth inhibitor for the nontransformed BRL cells. The transformed BRL cells (RSV-BRL) were insensitive to this inhibitor. The inhibitory activity was not prominent in sera from other species of animals tested except for rabbit; this serum inhibited the growth of RSV-BRL cells more strongly than that of BRL cells. The growth inhibitor was partially purified from rat serum. It is a protein free of lipid and has a molecular weight of about 220 000. The inhibitor could be separated into three components of pI 4.6, 5.2 (major) and 5.6 by isoelectric electrophoresis.

Response of malignant mammary cell lines to a growth inhibitor partially purified from plasma-derived human serum

The specificity and mode of action of a growth inhibitory factor (GIF) isolated from human plasma-derived serum (PDS) was examined with cell lines established from malignant and nonmalignant human tissues. The mammary cell line, MCF-7, was used in previous work to monitor purification of GIF from serum. The current study showed that, of 9 mammary cell lines, 5 (MDA-MB-415, BT-474, MCF-7, T47D, ZR-75) were inhibited by GIF partially purified from a single serum source. The degree of cell line sensitivity to DEAE-purified GIF was directly related to the amount of inhibition observed with unfractionated PDS. The growth of cells established from other malignancies (lung, colon, melanoma, cervix) and normal diploid fibroblasts was not inhibited. MCF-7 cell growth inhibition was fully reversible following 3 days incubation in GIF but was not reversible after 5 days. Inhibition represented a cytostatic effect. Among the macromolecular synthetic events assayed, DNA and RNA remained unaffected by GIF whereas protein synthesis per cell was markedly elevated. Fluorescence-activated cell sorter analysis of treated and control populations showed no differences in G1, S-, and G2 phase distributions.