Development of enzymo-immunoassays (EIA) for macrophage colony-stimulating factor (M-CSF) and leukaemia inhibitory factor (LIF) by using the same capture and signal generating polyclonal antibody

Specific high titre polyclonal antibodies rapidly obtained by intralymphnode immunization of rabbits with recombinant M-CSF and LIF (< 60 micrograms/animal) have been used to develop specific, accurate and sensitive EIAs. The same batch of purified anti-M-CSF or anti-LIF Igs has been used for the coating of 96-well plates (capture antibody) and for the quantitative detection of the bound cytokine molecules (soluble biotinylated Igs). The sensitivity (M-CSF: 10 IU/ml, LIF: 20 pg/ml), accuracy (intra-assay-CV: 8.2 to 12.8% for M-CSF; 0 to 19.9% for LIF) and reproducibility (inter-assay-CV: 7.9 to 13.6% for M-CSF; 4.9 to 17.5% for LIF) are equivalent to those for previously published RIAs or EIAs. These assays are highly specific since 11 other cytokines (Epo: 3 IU/ml; G-CSF: 100 IU/ml; CNTF, OSM, SCF, IL-1 beta, IL-2, IL-3, IL-6, IL-11, IL-13: 5 ng/ml) tested in both EIAs were not detectable. Finally, the M-CSF and LIF concentrations measured in various biological fluids were found to be similar to those measured by us and others with different assays. In conclusion, the methodology used for M-CSF and LIF EIAs presented in this work represents a valuable approach for most cytokines, particularly when they are still available in reduced amounts.

Purification and characterisation of swine serum proteinase which hydrolyses epidermal inhibitory pentapeptide

In this paper we describe the purification to molecular homogeneity of the enzyme that cleaves the synthetic epidermal mitosis-inhibiting pentapeptide (pyroGlu-Glu-Asp-Ser-Gly; EPP) from swine serum. Biochemical characterisation of the enzyme shows a glycoprotein with apparent molecular mass of 200 kDa. The Km and Kcat values for EPP hydrolysis are 0.624 mM and 694 s-1, respectively. Use of proteinase inhibitors shows the enzyme's metalloendopeptidase character. Moreover, captopril and lisinopril prevent the cleavage of EPP. The N-terminal amino-acid sequence of the purified protein corresponds to the N-terminal amino-acid sequence of swine kidney angiotensin-converting enzyme, a dipeptidyl carboxypeptidase (EC 3.4.15.1).

Release of leukemia inhibitory factor in primate sepsis. Analysis of the role of TNF-alpha

Leukemia inhibitory factor (LIF), a pleiotropic cytokine with many biologic effects overlapping with those of IL-6, has been implicated in the pathogenesis of sepsis. We here analyzed the kinetics of LIF in 13 baboons challenged with a lethal (n=6) or sublethal (n=7) dose of Escherichia coli. In addition, to assess the role of TNF-alpha in the induction of LIF in vivo, seven baboons were studied that had either received a bolus injection of recombinant human TNF-alpha (100 micrograms/kg, n=3), or to whom 15 mg/kg of an anti-TNF mAB before lethal E. coli challenge was administered (n=4). LIF levels increased 2 h after E coli challenge, and reached maximum values at 4 and 8 h after a sublethal (4.4 +/- 1.6 ng/ml) or lethal (40.9 +/- 3.8 ng/ml) dose, respectively. TNF-alpha injection induced a modest rise in LIF concentrations, peaking after 6 h (228 +/- 46 pg/ml). Circulating LIF correlated with plasma levels of IL-6, both after E. coli challenge (Spearman Rank coefficient of correlation (r) = 0.849, p<0.001), as well as upon TNF-alpha injection (r=0.863, p<0.001). Moreover, the E. coli-induced release of either cytokine was reduced 6- to 10-fold after pretreatment with anti-TNF mAb, except in one nonsurviving animal, which exhibited a progressive increase of LIF and IL-6 levels despite the absence of TNF immunoreactivity. These results show that TNF-alpha is an intermediate factor in concerted release of LIF and IL-6 in vivo, and indicate that the enhanced elaboration of these cytokines may predict disease outcome in severe sepsis.

Antimüllerian hormone as a serum marker of granulosa cell tumorsof the ovary: comparative study with serum alpha-inhibin and estradiol

OBJECTIVE

Our purpose was to evaluate serum antimüllerian hormone as a marker for granulosa cell tumors.

STUDY DESIGN

Serum antimüllerian hormone concentrations were determined in 16 patients with an adult-type granulosa cell tumor; in female patients with ovarian adenocarcinoma, benign ovarian cysts, or extraovarian cancers; and in normal premenopausal and postmenopausal women. Serum antimüllerian hormone, alpha-inhibin, and estradiol levels were compared in 10 patients with a granulosa cell tumor during 6 to 47 months of follow-up.

RESULTS

Serum antimüllerian hormone was undetectable in normal postmenopausal women and was <5 micrograms/L in premenopausal women. Normal serum levels were found in patients with ovarian cancers or cysts or with extraovarian cancers. Levels were between 6.8 and 117.9 microg/L in eight of nine patients with a progressive granulosa cell tumor. In the remaining case antimüllerian hormone, alpha-inhibin and estradiol concentrations were normal. Serum antimüllerian hormone and alpha-inhibin levels became elevated at least 11 months before the recurrence was clinically detectable. During clinical remission serum antimullerian hormone, beta-inhibin, and estradiol were normal in most cases.

CONCLUSION

Serum antimüllerian hormone is a sensitive, specific, reliable marker of adult-type granulosa cell tumors and is useful to evaluate the efficacy of treatment and to detect recurrences early.

Mullerian inhibiting substance in humans: normal levels from infancy to adulthood

Mullerian-inhibiting substance (MIS) is a gonadal hormone synthesized by Sertoli cells of the testis and granulosa cells of the ovary. To facilitate the use of MIS for the evaluation of intersex disorders and as a tumor marker in women with MIS-expressing ovarian tumors, we measured MIS in 600 serum samples from males and females. These data show that mean MIS values for males rise rapidly during the first year of life and are highest during late infancy, then gradually decline until puberty. In contrast, MIS values in females are lowest at birth and exhibit a minimal increase throughout the prepubertal years. Whereas MIS is uniformly measurable in all prepubertal boys studied, it is undetectable in most prepubertal female subjects. These data reveal an easily discernible sexually dimorphic pattern of expression and confirm that MIS can be used as a testis-specific marker during infancy and early childhood. MIS values that are above the upper limits for females are discriminatory for the presence of testicular tissue or ovarian tumor, and those below the lower limits for males are consistent with dysgenetic or absent testes or the presence of ovarian tissue. These data will enable normal and abnormal levels of MIS to be differentiated with higher precision and will facilitate the use of MIS in the management of gonadal disorders.

Acute angiotensin-converting enzyme inhibition increases the plasma level of the natural stem cell regulator N-acetyl-seryl-aspartyl-lysyl-proline

Angiotensin I-converting enzyme (ACE) has two homologous active NH2- and COOH-terminal domains and displays activity toward a broad range of substrates. The tetrapeptide N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) has been shown to be hydrolyzed in vitro by ACE and to be a preferential substrate for its NH2-terminal active site. This peptide is a regulatory factor of hematopoiesis which reversibly stem cells and normal early progenitors into S-phase. We found that a single oral dose of 50 mg of the ACE inhibitor, captopril, when administered to eight healthy subjects in a double-blind, crossover, placebo-controlled study, massively increased the plasma level of Ac-SDKP. ACE inhibition by captopril induced a 90-99% inhibition of in vitro [3H]Ac-SDKP hydrolysis and a long-lasting 5.5-fold (range: 4-8.5-fold) increase in the plasma levels of Ac-SDKP. These results demonstrate that Ac-SDKP is the first natural peptide hydrolyzed by the NH2-terminal domain of ACE not only in vitro but also in vivo, confirming that both catalytic sites of ACE are physiologically active. Our data suggest that ACE may also be implicated in the process of hematopoietic stem cell regulation, by permanently degrading this natural circulating inhibitor of cell entry into S-phase.

Dynamics of blood cytokine concentrations in patients with bacteremic infections

Cytokines play a major role in the pathophysiology of sepsis and septic shock. Using enzyme immunoassays the acute serum levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), granulocyte-colony stimulating factor (G-CSF), interleukin-8 (IL-8), and leukemia inhibitory factor (LIF) were investigated in 90 patients with positive blood cultures and clinical signs of infection. In 27 patients samples were obtained on admission, after 1, 4, 12, 18, and 24 h, and then daily. The acute serum levels of IL-6, TNF-alpha, G-CSF, and IL-8 were significantly higher among patients with severe sepsis. Patients with Gram-negative infection had significantly higher levels of TNF-alpha on admission than did patients with Gram-positive infections (p = 0.0008). The levels of IL-6, G-CSF and, to some extent, TNF-alpha decreased rapidly in survivors within the first 24 h of admission to hospital and institution of treatment. LIF was detected in 8/90 in both survivors and nonsurvivors.

Complement depletion during haemofiltration with polyacrilonitrile membranes

BACKGROUND

Polyacrylonitrile (PAN, AN69) dialysis membranes have been shown to improve the outcome of critically ill patients. Factor D is an essential enzyme of the alternative pathway of complement and is increased during renal failure. On the other hand the contact of blood with biomaterials activates the complement cascade through the alternative pathway. PAN filters adsorb factor D which looses its enzymatic activity whilst bound to the membrane [1]; the complement alternative pathway function of serum exposed to PAN filters is greatly diminished and restored after addition of purified factor D [1]. The aim of our study was to measure the time course of factor D adsorption and its blood concentration during CVVH in critically ill patients with acute renal failure.

METHODS

We studied seven critically ill patients with ARF before, during and after continuous veno-venous haemofiltration (CVVH) with AN69.

RESULTS

There was a rapid decrease of factor D levels to 62(+/-6%) of the pre-CVVH value during the first 2 h, which continued to 51(+/-7.3%) after 12 h; at 24 h there was a slight rise to 62 +/- 12%. Sequential use of Polyacrylonitrile (AN69) filters lowered factor D levels below the normal plasma concentration in three patients, thus producing a state of factor D depletion.

CONCLUSION

The significant reduction of factor D levels during CVVH with PAN filters suggests that frequent changes of PAN filters may reduce alternative pathway function by lowering factor D levels. CVVH (as opposed to intermittent dialysis) with PAN membranes may further improve the outcome of critically ill patients.

IGFBP-3 is a poor parameter for assessment of clinical activity in acromegaly

OBJECTIVE

Elevated serum IGF-I and IGF binding protein-3 (IGFBP-3) levels have been found in patients with active acromegaly. We have studied the relative diagnostic merits of measurements of IGFBP-3 compared with IGF-I as a parameter of disease activity in these patients.

DESIGN/PATIENTS

Thirty untreated patients with acromegaly were compared with 30 healthy adults.

MEASUREMENTS

Twenty-four-hour sampling for serum GH in patients with acromegaly, serum IGF-I and IGFBP-3.

RESULTS

Mean IGF-I levels were 22.0 nmol/l (range 6.5-38.4) in the healthy adults and 118.7 nmol/l (range 67.7-206.0) in patients with acromegaly. Mean IGFBP-3 levels were 3.5 mg/l (range 2.1-4.8) in controls and 5.4 mg/l (range 4.2-6.6) in patients with acromegaly. Mean IGF-I/IGFBP-3 ratios were 6.5 nmol/mg (range 1.9-14.5) in the healthy adults and 22.0 nmol/mg (range 14.3-32.7) in patients with acromegaly. There was a considerable overlap for IGFBP-3 levels but not for IGF-I levels, between normals and acromegalics. The IGF-I/IGFBP-3 ratio also showed overlap between normals and acromegalics. There was a significant correlation between the mean 24-hour GH and IGFBP-3 levels (P = 0.036) and between the IGF-I and IGFBP-3 levels (P < 0.002) in acromegaly. In patients with acromegaly, the IGFBP-3 levels showed a decrement, but the IGF-I/IGFBP-3 ratio did not change significantly with age.

CONCLUSIONS

IGFBP-2 has no additional discriminatory value over IGF-1 measurements for the assessment of clinical activity in acromegaly. In acromegaly, IGFBP-3 decreases with increasing age. In acromegaly, IGFBP-3 levels significantly correlate with mean 24-hour GH levels and IGF-I levels.

Disturbed anabolic hormonal patterns in burned patients: the relation to glucagon

OBJECTIVE

Complex changes in the anabolic regulators of metabolism occur after major injury. We have studied the time course for IGF-I and IGFBP-1 after burn injury and their relations to circulating levels of other anabolic and catabolic hormones. The hormonal patterns during the onset of sepsis were also investigated.

PATIENTS

Eight patients (age 36 (6) years, mean (SEM)) with major burn injury (burn area 42 (6) %) were studied. The first 2 days since the burn were used for rehydration therapy (rehydration period), after which a complete total parenteral nutrition (TPN) period was initiated. Seven positive blood cultures, during the study period. Six of the eight survived.

MEASUREMENTS

The hormonal changes determined in the morning during the first 7 days after the burn and from day 22 to 24 were investigated. The superimposed effects of sepsis were studied by normalizing all data to the day of positive blood cultures and clinical onset of sepsis.

RESULTS

On admission, plasma levels of glucagon, IGFBP-1 and GH were elevated while levels of IGF-I were low. During the first week after the burn, morning levels of glucagon and insulin increased while levels of GH and IGF-I decreased. GH levels were still elevated compared to healthy subjects. Despite the increase in insulin levels, IGFBP-1 remained elevated. Three weeks after the burn injury, IGF-I levels were increased but still markedly below normal, while IGFBP-1 levels remained unchanged. Persistent elevations of insulin levels were combined with reductions in glucagon levels. Admission levels of IGFBP-1 correlated to nitrogen loss (negative nitrogen balance) during the first 24 hours after the burn (r = 0.84, P < 0.05). A correlation between negative nitrogen balance and glucagon levels was found during early catabolic period in the rehydration period (i.e. days 2-3, r = 0.84, P < 0.01). The relative change in IGFBP-1 levels in the rehydration period correlated to changes in glucagon levels (days 2-3 vs admission, r = 0.85, P < 0.05). The insulin/glucagon molar ratio correlated to the IGF-I/IGFBP-1 ratio during both the rehydration period (days 2-3, r = 0.77, P < 0.05) and the third week after the burn (r = 0.77, P < 0.05). During the most catabolic phase in the first week after the burn (TPN period) there was an inverse relation between IGF-I and IGFBP-I and glucagon (r = 0.83, P < 0.05). During the less catabolic third week after the burn, an inverse correlation was found between IGF-I and glucagon (r = -0.83, P < 0.05). Sepsis, superimposed upon the burn trauma, was associated with transient elevations in IGFBP-1 and reductions in insulin despite elevated levels of glucose and a further 50% increase in nitrogen losses.

CONCLUSIONS

The present findings show that marked changes is important anabolic regulating factors occur after major burn injury. Uncoupling of the GH-IGF-I axis, and the attenuation of the inhibitory effects of insulin on IGFBP-1, both contribute to the reduction in IGF-I levels and bioavailability, factors which may play an important role in post injury metabolism. Furthermore, these data suggest that the catabolic hormones (catecholamines, cortisol and glucagon), primarily glucagon seem to be involved in the modulation of IGF-I and IGFBP-1 levels following burn injury.

Production of hematopoietic regulatory factors in cultures of adult and fetal mouse organs: measurement by specific bioassays

Factor-specific cell line bioassays were used to monitor the production in vitro by adult and fetal mouse organs of GM-CSF, G-CSF, M-CSF, Multi-CSF (IL-3), IL-6 and leukemia inhibitory factor (LIF). No tissue was observed to produce Multi-CSF. Highest producers of the other regulators were lung, muscle, thymus, heart and bone shaft and all tissues producing detectable growth factors produced all five with the same rank order of activity. Adult tissues produced more GM-CSF than G-CSF and less M-CSF than either, no differences being observed between male, female and pregnant female tissues. In contrast, the pregnant uterus produced high levels of M-CSF as did the fetal membranes and tissues with only low GM-CSF and no G-CSF production. Pre-irradiation did not alter the pattern of regulator production by adult tissues. The intravenous injection of endotoxin elevated serum levels of GM-CSF, G-CSF, M-CSF and IL-6 but the dominant rise was in G-CSF levels. The data indicating that multiple organs produce the regulators monitored in a common rank order suggest some overall linkage in their production with major differences between adult and fetal tissues.

LPS-induced release of EGF, GM-CSF, GRO alpha, LIF, MIP-1 alpha and PDGF-AB in PBMC from persons with high or low levels of HDL lipoprotein

We have examined basal and lipopolysaccharide (LPS)-induced release of epidermal growth factor (EGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), growth-regulated peptide alpha (GRO alpha), leukaemia inhibitory factor (LIF), macrophage inflammatory protein-1a (MIP-1 alpha) and platelet-derived growth factor-AB (PDGF-AB) in peripheral blood mononuclear cells (PBMC) from 20 persons with either high (n = 10) or low (n = 10) levels of high-density lipoprotein (HDL). PBMC were incubated with 100 ng LPS/ml for up to 160 h, and showed a significantly higher release of the chemokines GRO alpha (P = 0.04) and MIP-1 alpha (P < 0.01) in persons with high HDL, whereas levels of GM-CSF were similar. Levels of EGF, LIF and PDGF-AB were always low, and remained unaltered during 160 h of incubation. These findings indicate that PBMC from persons with high or low levels of HDL have different functional properties, of importance in cell recruitment and activation.

Reversal of immunosuppression of lymphocyte proliferation caused by sera from persons with AIDS

Sera from persons with AIDS contain inhibitors of lymphocyte proliferation. Inhibitory activity can be detected before the development of AIDS in humans. There appear to be at least three distinct suppressive moieties, one of which is prostaglandin E2. We and others had previously shown that serum samples from subjects with AIDS contained antibody to the cell line HUT 102B2. We attempted to remove this antibody and to determine if that action would also remove the inhibitory activity present in human immunodeficiency virus-positive sera. We incubated sera from subjects with AIDS with HUT 102B2 cells and tested the resultant supernatants for inhibition of cell proliferation. We found that this procedure significantly reversed inhibition by serum. Other cells and cell lines were similarly tested, but only HUT 102B2 cells absorbed the inhibitory product(s). However, we determined that secretory material from another cell line, MLA 144, also reversed inhibition. The physical characteristics of the supernatant were investigated. Thus, two procedures and likely separate products, possibly cytokines, reverse immunosuppression by sera from persons with AIDS.

Role of hyperbilirubinemia in the impairment of osteoblast proliferation associated with cholestatic jaundice

Because the osteoporosis occurring in chronic cholestatic liver disease (CCLD) is associated with decreased bone formation and is reversible by liver transplantation, substances retained in plasma during cholestasis may impair osteoblast function. This hypothesis was tested using a new bioassay that measures plasma mitogenic activity (PMA) for normal human osteoblast-like (hOB) cells. In 29 jaundiced patients, mean PMA was 56.4% (P < 0.001) of that in 29 age- and sex-matched normal subjects, and the decrease in PMA was similar in the 14 with CCLD and the 15 with other causes of jaundice. Bile acids and bilirubin are the two major groups of products retained during cholestasis. The common conjugated bile acids and bilirubin were added to normal human plasma in concentrations simulating those found in patients with CCLD. Various bile salts had no effect on PMA whereas unconjugated bilirubin decreased PMA in a dose-dependent fashion (r = -0.98, P < 0.0001) without affecting cell viability. Relatively selective removal of bilirubin from the plasma by photobleaching normalized the decreased PMA in five jaundiced patients but produced no apparent change in five normal subjects. These data support the hypothesis that hyperbilirubinemia or possibly other photolabile substances impair osteoblast proliferative capacity and thus may play a major role in the pathogenesis of the osteoporosis associated with CCLD.

Long-term effects of insulin-like growth factor (IGF)-I treatment on serum IGFs and IGF binding proteins in adolescent patients with growth hormone receptor deficiency

OBJECTIVE

The aim of this investigation was to study the effect of relatively high dose IGF-I therapy given for several months, on serum levels of IGF-I, IGF-II and IGFBP-3, and on IGF-I pharmacokinetics in patients with growth hormone insensitivity due to GH receptor dysfunction.

DESIGN AND PATIENTS

Two adolescent subjects from Ecuador were treated with recombinant IGF-I at a dosage of 120 micrograms/kg s.c. twice daily, in combination with a GnRH analogue for 8 months.

MEASUREMENTS

Serum was sampled at baseline and at 3-8 months, for determination of IGF-I, IGF-II and IGFBP-3 by radioimmunoassay, and for evaluation of IGFBPs and IGFBP-3 protease activity by Western ligand blot and protease assay, respectively.

RESULTS

Peak serum IGF-I levels ranged from 272 to 492 micrograms/l. Mean serum IGF-II levels were decreased concurrently with the increase in IGF-I. Serum IGFBP-3 levels failed to rise with prolonged IGF-I treatment. There was no apparent change in the half-life of IGF-I during the treatment period.

CONCLUSIONS

IGF-I administration does not increase serum levels of IGFBP-3 or significantly alter IGF-I pharmacokinetics.

Effect of sodium selenite on growth, insulin-like growth factor-binding proteins and insulin-like growth factor-I in rats

Selenium is an essential trace element although at higher doses it is also known to be a toxic agent causing a wide range of symptoms including growth retardation. In order to investigate the effect of sodium selenite on growth, insulin-like growth factor-binding proteins (IGFBPs) and insulin-like growth factor-I (IGF-I), 30 male Wistar rats were randomized into three groups. Group A was treated with sodium selenite in the drinking water (3.3 mg selenium/l). Group B was ad libitum fed with free access to standard fodder and tap water and group C was pair fed relative to the selenium-treated rats. Serum IGF-I and IGFBPs were determined on days 0, 14 and at the end of the study on day 35. Selenium-treated rats had significantly lower body weights compared with group B rats on day 9 and group C rats on day 14 (P < 0.05). Tibia length was measured at the end of the study and no difference was observed between groups B and C (3.77 +/- 0.04 cm vs 3.60 +/- 0.02 cm); however, selenium-treated rats had significantly shorter tibia lengths (3.46 +/- 0.03 cm) compared with rats in groups B (P < 0.001) and C (P < 0.05). Selenium treatment induced a significant reduction in circulating IGF-I by the end of the study compared with ad libitum and pair fed rats (P < 0.05). Serum subjected to Western ligand blots showed four distinct IGFBP bands with apparent relative molecular weights of 38-47 kDa (doublet) (IGFBP-3), 30 kDa (IGFBP-1 and/or IGFBP-2) and 24 kDa (IGFBP-4).(ABSTRACT TRUNCATED AT 250 WORDS)

Leukemia inhibitory factor protects against experimental lethal Escherichia coli septic shock in mice

Leukemia inhibitory factor (LIF) has recently been associated with septic shock in humans. In this study we sought to determine, in mice, the role of LIF in septic shock. During sublethal endotoxemia, serum LIF levels, as determined by radio-receptor competition assay, peaked at 2 h and were low (3 ng/ml), whereas in lethal Escherichia coli septic shock serum LIF levels rose progressively (> 30 ng/ml) in the premorbid phase coincident with the development of tissue injury. Single i.v. injections of high doses (up to 50 micrograms per mouse) of recombinant murine LIF had no obvious acute detrimental effects, whereas continued i.p. administration (30 micrograms per mouse per day) for 3-4 days induced a fatal catabolic state without evidence of preceding hemodynamic collapse or shock. Simultaneous or subsequent administration of high doses of LIF had no effect on mortality from sublethal and lethal E. coli septic shock, whereas prior administration conferred significant protection against lethality (P << 0.001 by log-rank test), an effect that was dose and interval dependent. This protective effect resembled endotoxin tolerance and was characterized by suppression of E. coli-induced serum tumor necrosis factor concentration (P < 0.05), reduction in the number of viable bacteria (P < 0.05), and prevention of sepsis-induced tissue injury. These observations suggest that systemic LIF production is part of the host response to both endotoxin and sepsis-induced tissue injury.

Ontogeny of reproductive abnormalities induced by deregulation of anti-müllerian hormone expression in transgenic mice

Anti-müllerian hormone, normally responsible for the regression of müllerian ducts in male fetuses, induces stunting, germ cell loss, and seminiferous tubule formation in ovaries of bovine freemartin fetuses and of transgenic mice, which express the human anti müllerian hormone gene under the control of the metallothionein promoter. Because the latter have been studied only after birth, we undertook a detailed chronological study of their reproductive organs. Müllerian ducts of transgenic female fetuses regressed at the same time as those of normal or transgenic males. Maximal reduction of germ cell number occurred between 16 days postcoitus and birth, when most transgenic oocytes were still in the leptotene stage of the meiotic prophase, whereas normal oocytes had already reached the pachytene phase. Interference with progression of the meiotic prophase and germ cell loss in the fetal ovary are probably responsible for subsequent ovarian regression and retardation of follicle growth. Seminiferous tubule formation was not detectable prior to birth and occurred only rarely in postnatal ovaries. Aromatase activity of fetal transgenic ovaries was decreased, as well as serum concentration of testosterone in adult transgenic males, suggesting that high levels of anti-müllerian hormone may impair Leydig cell steroidogenesis.

[Changes in IGFBP-3 in relation to administration of rGH to deficient children]

Serum IGFBP3 levels were tested in 7 GHD children before the rGH therapy, at the end of the same therapy and 1, 2, 4, and 8 weeks later. The IGFBP3 concentration returned to the pre-therapy levels only 6 weeks after the end of the therapy.

Paediatric applications of anti-müllerian hormone research. 1992 Andrea Prader Lecture

Anti-müllerian hormone (AMH), a member of the transforming growth factor family also called müllerian-inhibiting substance or factor, is produced by immature Sertoli cells and, in much smaller amounts, by postnatal granulosa cells. Its paediatric applications are essentially diagnostic. Measurement of AMH concentration in serum by an enzyme-linked immunosorbent assay does not require prior gonadal stimulation and is useful to detect the presence of testicular tissue and assess its function before puberty. The assay can easily differentiate between bilateral cryptorchidism and anorchia and discriminates between non-adrenal female pseudohermaphroditism and true hermaphroditism, although in the latter condition, the serum AMH concentration is usually low because of testicular dysgenesis. After puberty, AMH becomes low or undetectable, due to down-regulation of AMH production by testosterone. This does not occur in androgen-insensitive patients. A rare form of male pseudohermaphroditism, the persistent müllerian duct syndrome, characterized by the persistence of a uterus and tubes in otherwise normally virilized males, is due to defects in genes coding for AMH or its receptor. Measurement of serum AMH concentration discriminates between the two aetiological forms of the syndrome.

Increased plasma levels of human interleukin for DA1.a cells/leukemia inhibitory factor in sepsis correlate with shock and poor prognosis

Animal study results have suggested a role in sepsis for human interleukin for DA1.a cells/leukemia inhibitory factor (HILDA/LIF). HILDA/LIF and interleukin-6 (IL-6) levels were prospectively studied by serial ELISAs in 34 septic patients. HILDA/LIF was detected in 11 of 34 patients at plasma levels of 100-37,000 pg/mL. Peak HILDA/LIF levels correlated with increased temperature and creatinine and IL-6 and with decreased arterial CO2 (P < .05). Multivariate analysis showed that shock and decreased arterial CO2 accounted for 75% of peak HILDA/LIF plasma variations (R2 = .753). Fatal outcome was most often associated with detectable HILDA/LIF (> 56 pg/mL) and peak IL-6 plasma levels > 850 pg/mL (sensitivity, 83%; specificity, 87%), but both (at respective levels of > 480 and > 850 pg/mL) were associated with fatal outcome. HILDA/LIF was detected in septic patients exhibiting shock, and its levels correlated with higher mortality and shorter survival.

Resistance of nitrogen metabolism to growth hormone treatment in the early phase after injury of patients with multiple injuries

OBJECTIVES AND DESIGN

Several studies have shown an anticatabolic effect of recombinant human growth hormone (rhGH) in surgical patients. We investigated, in a prospective, randomized, double blind, and placebo-controlled study, the effect of r-hGH on hormone and nitrogen metabolism in 14 patients with multiple injuries in the early phase of injury.

MATERIALS AND METHODS

All patients were treated in the intensive care unit, had mechanical ventilation, and were highly catabolic, with a mean daily nitrogen loss of 13.2 +/- 1.8 g. r-hGH was given subcutaneously (once a day, at 8 PM) in a dosage of 0.2 IU/kg.d for seven days, starting on the second day after injury.

RESULTS

Administration of r-hGH evoked a significant increase in plasma concentrations of GH, insulin-like growth factor-I (IGF-I), and insulin-like growth factor binding-protein-3 (IGFBP-3). No significant differences were found for either daily or cumulative nitrogen balances (-103.1 +/- 14 g for patients receiving r-hGH and -92.1 +/- 18.1 for those with placebo). r-hGH therapy did not affect skeletal muscle extracellular water, nor did it affect plasma or muscle concentrations of total free amino acids or glutamine. Plasma albumin, prealbumin, and retinol-binding protein concentrations were also unchanged by r-hGH therapy, as were the urinary excretion of potassium and urea.

CONCLUSIONS

We conclude that elevated plasma levels of GH, insulin, and IGF-I are unable to effect a protein anabolic drive in patients with multiple injuries during the early postinjury phase and assume that this r-hGH resistance to nitrogen metabolism takes place at the level distal to IGF-I.

One-year enzyme-linked immunosorbent assay follow-up of human interleukin for Da cells/leukemia inhibitory factor in blood and urine of 22 kidney transplant recipients

The cytokine human interleukin for Da cells/leukemia inhibitory factor (HILDA/LIF) exerts multiple biological effects in vitro. In mice, high circulating levels of HILDA/LIF induce a wide range of pathophysiological events, some of them closely involved with immunological and inflammatory responses. Using a sandwich ELISA recognizing the natural human HILDA/LIF molecule with a threshold of 50 pg/ml in urine and 150 pg/ml in plasma, we monitored the urine and plasma HILDA/LIF levels of 22 patients in their first year after a kidney transplant. HILDA/LIF urine excretion is increased during acute rejection, and infections also trigger heavy HILDA/LIF plasma concentrations or urine excretion. In addition, this study raises the question of HILDA/LIF involvement in post-kidney-transplant phenomena such as hypercalcemia, osteoporosis, or the reversal of anemia.

Circulating leukemia inhibitory factor levels correlate with disease severity in meningococcemia

Circulating concentrations of the proinflammatory cytokine leukemia inhibitory factor (LIF) were prospectively determined by radioreceptor competition assay (sensitivity, 1 ng/mL) in 33 subjects with meningococcemia. LIF was detected in the plasma of 13 subjects and was associated with development of septic shock (P < .01), disseminated intravascular coagulation (P < .05), multiorgan failure (P < .05), and death (P < .01). Plasma LIF concentrations were highest (1-1772 ng/mL) at hospital admission and became undetectable within 36 h, and the peak levels correlated inversely with systolic blood pressure (r, -.70, P < .001), peripheral blood leukocyte count (r, -.58, P < .01), and prodromal interval (r, -.60, P < .001). Plasma LIF concentrations > 400 ng/mL were present only in subjects with fatal fulminant infection. LIF concentrations in plasma collected within 12 h of hospital admission correlated with disease severity in patients with meningococcemia. It is likely that LIF participates in the host response to infection, and it may contribute to the pathogenesis of septic shock.

The insulin-like growth factor axis and collagen turnover during prednisolone treatment

Serum concentrations of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein 3 (IGFBP-3), the carboxyterminal propeptide of type I collagen (PICP), the carboxyterminal pyridinoline crosslinked telopeptide of type I collagen (ICTP), and the aminoterminal propeptide of type III procollagen (PIIINP) were studied in 10 prepubertal children with asthma (mean age 9.0 years). The children were treated with 2.5 and 5.0 mg/day prednisolone in a randomised double blind crossover trial with run in, treatment, and washout periods of two weeks. No statistically significant effects on serum concentrations of IGF-I and IGFBP-3 were found. Dose related reductions of PICP, ICTP, and PIIINP were observed: the mean (SEM) reduction in PICP was 33.4 (26.3) and 68.4 (20.6) micrograms/l, in ICTP 2.5 (0.5) and 2.9 (0.6) micrograms/l, and in PIIINP 2.1 (0.7) and 3.1 (1.8) micrograms/l during the 2.5 and 5.0 mg prednisolone periods respectively. Short term treatment with low daily doses of prednisolone is associated with suppression of serum markers of type I and III collagen turnover in children with asthma. Intermediate and long term effects remain to be studied.

[Persistent müllerian duct syndrome (males with uterus): a pediatric problem]

BACKGROUND

The persistent müllerian duct syndrome (PMDS) is characterized by the persistence of the uterus and Fallopian tubes in otherwise normally virilized boys. Its diagnosis is usually made during a surgical procedure for inguinal hernia or cryptorchidism. We report six recent cases of PMDS, in which we have studied anti-Müllerian hormone (AMH) serum levels.

CASE REPORTS AND METHODS

Six boys including three brothers were operated on for cryptorchidism or inguinal hernia. Surgical exploration showed persistence of the uterus and Fallopian tubes in patients having normal 46, XY karyotype and male gonads. The AMH serum levels were measured by Elisa and the AMH gene by single strand conformation polymorphism of PCR products.

RESULTS

The three brothers showed a mutation in the AMH gene which leads to the replacement of leucine by proline at position 70 and to a defect in AMH production. In two other patients, serum AMH values were normal, no mutation on the AMH gene was found, and end-organ insensitivity was suggested to explain the persistence of müllerian derivatives. In the last patient, although AMH serum levels were very low due to a progressive degeneration of testicular tissue, molecular analysis of the AMH gene suggested that end-organ resistance might be the cause of the persistence of müllerian ducts.

CONCLUSION

PMDS is not extremely rare. Many diagnostic mistakes are made which could be prevented by performing pelvic or inguinal ultrasonography before surgical treatment of bilateral cryptorchidism or irreducible inguinal hernia. Prognosis depends upon the integrity of the testicular tissue, sometimes compromised for yet unexplained reasons, and upon the successful correction of cryptorchidism, which is complicated by the close anatomical relationship between the vasa deferentia and the Müllerian derivatives.

Angiostatin: a novel angiogenesis inhibitor that mediates the suppression of metastases by a Lewis lung carcinoma

The phenomenon of inhibition of tumor growth by tumor mass has been repeatedly studied, but without elucidation of a satisfactory mechanism. In our animal model, a primary tumor inhibits its remote metastases. After tumor removal, metastases neovascularize and grow. When the primary tumor is present, metastatic growth is suppressed by a circulating angiogenesis inhibitor. Serum and urine from tumor-bearing mice, but not from controls, specifically inhibit endothelial cell proliferation. The activity copurifies with a 38 kDa plasminogen fragment that we have sequenced and named angiostatin. A corresponding fragment of human plasminogen has similar activity. Systemic administration of angiostatin, but not intact plasminogen, potently blocks neovascularization and growth of metastases. We here show that the inhibition of metastases by a primary mouse tumor is mediated, at least in part, by angiostatin.

Anti-müllerian hormone in children with androgen insensitivity

Anti-Müllerian hormone (AMH), also called Müllerian inhibiting substance or factor, is secreted in high amounts by the immature Sertoli cell; it is negatively regulated by testosterone at puberty. In the present study, we measured serum AMH in 20 patients with defects of androgen synthesis or action: 9 with complete androgen insensitivity syndrome, 9 with a partial form, 1 patient with 3 beta-hydroxysteroid dehydrogenase deficiency, and 1 with Leydig cell agenesis. AMH was also determined in 15 control patients with idiopathic male pseudohermaphroditism. The serum AMH concentration was elevated in all testosterone-insensitive or -deficient patients compared with control levels during the first year of life. From 1 yr of age to the onset of puberty, serum AMH levels in patients with androgen insensitivity returned to normal values, but after pubertal development began, AMH levels again rose to extremely high levels in the complete androgen insensitivity syndrome. These results suggest that AMH is negatively regulated by testosterone not only at puberty, but also during the postnatal period. An elevation of serum AMH appears to be an interesting marker of androgen resistance or defect of androgen production in sexually ambiguous male infants.

Disturbances in growth hormone secretion and action in adolescents with anorexia nervosa

Women in whom anorexia nervosa develops during adolescence have failure of linear growth associated with low levels of insulin-like growth factor I (IGF-1). To investigate the pathophysiology of growth retardation in adolescents with anorexia nervosa, we measured basal growth hormone (GH), growth hormone-binding protein (GHBP), IGF-1, and insulin-like growth factor binding protein-3 (IGFBP-3) in three groups of patients: (1) 28 recently hospitalized female adolescents with anorexia nervosa, (2) 23 of the same patients after partial weight restoration, and (3) 28 healthy control subjects matched for age, sex, and pubertal stage. Fasting GH levels in group 1 did not differ significantly from those in group 3. In contrast, serum GHBP (p < 0.001), IGF-1 (p < 0.001), and IGFBP-3 (p < 0.01) were significantly lower in group 1 than in group 3. Serum GHBP and IGFBP-3 levels were positively correlated with body mass index. Serum GHBP levels were low in patients in all five pubertal stages and even in those shown to have adequate GH secretion. In group 2 (after refeeding) the serum IGF-1 concentration increased significantly and GHBP and IGFBP-3 returned to normal. We conclude that patients with anorexia nervosa have diminished GH action resulting in decreased secretion of IGF-1. The positive correlation with body mass index and the reversibility with refeeding suggest that these changes are secondary to malnutrition. Altered GH function that occurs during the years of active growth can explain the growth retardation seen in anorexia nervosa.

[Antimullerian hormone in clinical human applications]

Anti-Müllerian hormone (AMH) is synthesized by immature Sertoli cells and by postnatal granulosa cells. Assay of serum AMH is useful in clinical situations to search for the presence of testicular tissue or to assess its functional value before puberty. At the time of puberty, serum levels of AMH decrease dramatically, a negative correlation has been demonstrated between AMH and testosterone serum levels. AMH assay is also useful in a rare form of male pseudohermaphroditism, characterized by the persistence of uterus and tubes in an otherwise normally virilized patient. AMH levels are undetectable or severely decreased in the case of a mutation of the AMH gene itself. In contrast, the concentration of serum AMH is normal if the syndrome is due to an insensitivity of AMH target organs.

Recurrent ovarian sex cord tumor with annular tubules: tumor marker and chemotherapy experience

Recurrent sex cord tumor with annular tubules is an unusual ovarian cancer. The authors report a patient with recurrent disease that was ultimately followed with multiple tumor markers. During this period the patient was treated only with chemotherapy. Her regimen consisted of a combination of etoposide, bleomycin, and cisplatin. The tumor markers that were followed were CA-125, CEA, inhibin, and Müllerian-inhibiting substance (MIS). There was no elevation of the CA-125 or CEA, but inhibin and MIS proved to be effective markers. Serum inhibin and MIS correlated perfectly with her documented disease status and was brought into the normal range when the patient was disease-free. This disease-free status was proven by surgical reexploration. This report is the first documented complete response in this rare malignancy treated by chemotherapy alone with distant metastatic spread. It also gives strong linkage of inhibin and MIS as good markers in this particularly rare malignancy.

Glyoxalase system in clinical diabetes mellitus and correlation with diabetic complications

1. The metabolism of methylglyoxal by the glyoxalase system may be linked to the development of diabetic complications. The glyoxalase system was characterized in blood samples from patients with insulin-dependent diabetes mellitus (n = 43), patients with non-insulin-dependent diabetes mellitus (n = 107) and 21 normal healthy control subjects. 2. The concentrations of glyoxalase metabolites, methylglyoxal, S-D-lactoylglutathione and D-lactate, were increased in diabetic patients, relative to normal control subjects: methylglyoxal [median, range (n) pmol/g], insulin-dependent patients, 470.7, 85.6-1044.3 (42), P < 0.001, non-insulin-dependent patients, 286.8, 54.7-2370 (105), P < 0.001, control subjects, 79.8, 25.3-892.9 (21); S-D-lactoylglutathione [mean +/- SD (n)pmol/10(6) erythrocytes], combined diabetic patients, 3.37 +/- 0.85 (24), control subjects 4.76 +/- 1.95 (8) P < 0.05; D-lactate [mean +/- SD or median, range (n)nmol/g], insulin dependent patients, median 18.3, 5.7-57.4 (42), P < 0.001, non-insulin-dependent patients, 20.0 +/- 8.9, 2.6-48.4 (105), P < 0.001, control subjects 9.7 +/- 4.3, 1.8-19.7 (21). The reduced glutathione concentrations in blood samples from the insulin-dependent and non-insulin-dependent diabetic patient groups were not different from the control group values (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of a polyclonal antiserum to rat growth hormone on circulating insulin-like growth factor (IGF)-I and IGF-binding protein concentrations and the growth of muscle and bone

A polyclonal antiserum to rat GH (anti-rGH) injected into rats for 3 or 8 weeks markedly reduced the weight, total protein and RNA content of muscles of the hind limb. These effects were prevented when bovine GH (bGH) was administered simultaneously. In a second experiment, the effects of 8 weeks of treatment with anti-rGH on the growth of the whole body, muscle and bone were investigated. Body weights of rats were decreased by 58% by treatment with anti-rGH; muscle weights were reduced by slightly more than the decrease in body weight (by 64%, 65% and 61% respectively for plantaris, soleus and gastrocnemius). The weight of the tibia was decreased by 54%, its length was decreased by 23%, cortical width and overall width were reduced by 26% and 18% respectively, suggesting a possible role for GH in osteoclastic activity. Serum total insulin-like growth factor-I (IGF-I) concentrations were decreased by 80-90% in both experiments by anti-rGH; these changes were prevented in the first experiment by concurrent treatment with anti-rGH and bGH. The serum IGF-binding protein-3 (IGFBP-3) concentration was also decreased by anti-rGH in experiment 1 (by 86%); the response of the 28-32 kDa IGFBPs was smaller (-35%), and was restored to control values by simultaneous injection of bGH. Western immunoblotting using an antiserum to IGFBP-2 showed that there was a marked decrease from neonatal to adult stages which was independent of anti-rGH treatment. This clearly demonstrated a dissociation of the reciprocal relationship supposed to exist between IGFBPs-2 and -3. The 24 kDa IGFBP-4 was unaffected by anti-rGH but replacement therapy with bGH doubled its concentration. Although the effects on body and muscle weight were prevented when rats were given anti-rGH and bGH simultaneously, the possibility of mediation by other hormones cannot be precluded.

Decreased ternary complex formation and predominance of a 29 kDa IGFBP-3 fragment in human fetal serum

Insulin-like growth factor-I (IGF-I) has been proposed to be important in the endocrine control of fetal growth in humans, although serum IGF-I concentrations are 10-fold lower than during rapid pubertal growth. However, the bioavailability of IGF-I in fetal serum may be increased by changes in the specific IGF binding proteins (IGFBPs). We have recently suggested that the bioavailability of circulating IGF-I is increased in the human fetus due to the molar excess of IGF-I plus IGF-II relative to IGFBP-3 as well as the increased concentrations of IGFBP-2, which does not form a long-lived ternary complex. We have presently studied ternary complex formation between IGF, IGFBP-3, and acid labile subunit (ALS) to further assess if IGF-I bioavailability is increased in human fetal serum. In 19-35 week gestation fetal sera, a markedly decreased formation of the ternary complex was demonstrated by the general absence of IGFBP-3 (detected by Western immunoblotting) in the approximately 130-150 kDa ternary complex after neutral size chromatography. The predominant form of IGFBP-3 in fetal serum was a 29 kDa fragment, which, following deglycosylation by Endoglycosidase-F, was demonstrated to consist of a approximately 20 kDa protein core. Despite the predominance of the 29 kDa IGFBP-3 fragment, we have previously demonstrated that the IGFBP-3 protease activity is not increased in fetal serum, in contrast to pregnancy or non-insulin dependent diabetes mellitus (NIDDM) sera.(ABSTRACT TRUNCATED AT 250 WORDS)

Humoral inhibitor of rat hepatocyte DNA synthesis from patients with fulminant liver failure

Sera and ultrafiltrates (relative molecular mass < 10,000 Da) from patients with fulminant liver failure inhibit hepatocyte DNA synthesis in vivo. In this study the effects of ultrafiltrates from pooled sera from fulminant liver failure patients in the United Kingdom and plasma ultrafiltrates from fulminant liver failure patients in Japan have been investigated in primary cultured rat hepatocytes, with incubation for up to 72 hr. Both types of ultrafiltrate inhibited the incorporation of [3H]thymidine into acid-precipitable material and reduced the cell labeling index as determined on autoradiography in hepatocytes stimulated by epidermal growth factor and insulin compared with normal sera/plasma ultrafiltrates. The inhibitory effects observed were dose dependent, reversible when the fulminant liver failure ultrafiltrate was removed and were not associated with increased release of lactate dehydrogenase or suppression of protein synthesis as assessed on the basis of the incorporation of [3H]leucine. The effects appeared to be specific for hepatocytes; in preliminary experiments DNA synthesis was not inhibited in cultured fibroblasts (NIH 3T3 cells). These experiments are further evidence of the presence of an inhibitory factor of relative molecular mass less than 10,000 Da in the blood of patients with fulminant liver failure.

Acquired amegakaryocytic thrombocytopenic purpura with humoral inhibitory factor for megakaryocyte colony formation

A 67-year-old man with thrombocytopenia, and amegakaryocytic but otherwise normal bone marrow, was evaluated. Antibody against thrombocytes was negative and the half-life of thrombocytes was normal. In vitro clonal culture of the patient's bone marrow cells yielded no megakaryocyte colony with normal granulocyte-macrophage and erythroid colony formation. Megakaryocyte colony formation of the control bone marrow cells was significantly suppressed by the addition of the patient's serum to the culture, suggesting the existence of humoral inhibitory factor(s) for megakaryocyte colony formation. Therapeutic trials with plasma exchange, cyclosporine, prednisolone, and cyclosporine plus prednisolone were all unsuccessful, but serious bleeding has been absent.

Pharmacokinetics and metabolic effects of growth hormone injected subcutaneously in growth hormone deficient patients: thigh versus abdomen

OBJECTIVE

The absorption of insulin following subcutaneous (s.c.) injection is faster in the abdomen than the thigh. We therefore studied the effect of changing the site of injection on the absorption and metabolic effects of human growth hormone.

DESIGN AND MEASUREMENTS

In a cross-over study human GH (Norditropin) was injected s.c. in the thigh or abdomen in random order. Ultrasonography of the thigh and abdomen was performed in order to evaluate the thickness of the s.c. tissue. After each treatment period (4 weeks), serum profiles of GH, IGF-I, IGF binding proteins 1 and 3 (IGFBP-1 and IGFBP-3), glucose, insulin, non-esterified fatty acids (NEFA), glycerol, 3-hydroxybutyrate, alanine, lactate and glucagon were measured for 37 hours after GH injection (3 IU/m2 at 1900 hour).

PATIENTS

Nine GH deficient patients (five males, four females).

RESULTS

The mean (+/- SEM) thickness of the s.c. tissue (mm) was higher on the abdominal site (9.35 +/- 1.38 (thigh), and 22.61 +/- 2.19 (abdomen), P < 0.001). Mean (+/- SEM) integrated levels (area under the curves (AUC) divided by time) of GH (mU/l) were identical: 5.54 +/- 0.70 (thigh) versus 5.48 +/- 0.64 (abdomen) (P = 0.91). AUC (mU/l) for the initial 6 hours were, however, significantly different (14.10 +/- 3.76 (thigh) and 19.02 +/- 3.18 (abdomen), P = 0.02). Maximal serum concentration (Cmax) (mU/l) 23.18 +/- 3.86 (thigh) and 29.66 +/- 4.78 (abdomen) (P = 0.19) was achieved faster (Tmax) following injection in the abdomen. Tmax (hours) was 5.89 +/- 0.41 (thigh) and 4.26 +/- 0.49 (abdomen) (P < 0.002). Mean IGF-I levels (microgram/l) were unaffected by GH injection sites (355 +/- 60 (thigh) and 365 +/- 63 (abdomen), P = 0.61). Mean IGFBP-3 levels (microgram/l) were significantly different (2100 +/- 143 (thigh), and 2350 +/- 176 (abdomen), P = 0.05). Mean levels of IGFBP-1, insulin, glucose, lipid intermediates, metabolites and glucagon were not significantly different.

CONCLUSIONS

Human GH was absorbed faster when injected s.c. in the abdomen as compared with the thigh, despite the thicker s.c. tissue on the abdomen. Apart from higher IGFBP-3 levels after s.c. injections in the abdomen, similar metabolic effects of GH were obtained with the two injection sites.

Regulation of insulin-like growth factor-I and binding protein-3 expression in oMtla-oGH transgenic mice

Growth hormone (GH)-transgenic mice provide a model for studying hormonal regulation of gene products responsible for efficient lean growth. Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (BP-3) are two products involved in mediating the growth promoting actions of GH. Mice carrying the ovine metallothionein la-ovine growth hormone (oMtla-oGH) transgene were used to study GH regulation of IGF-I and BP-3 expression because these mice do not exhibit elevated basal oGH levels without transgene stimulation by exogenous zinc. C57B1/6XCBA mice with (transgenic = TG) and without control = C) the oMtla-oGH transgene were activated (+ Zn) or inactivated (-Zn) by the addition or removal of 25 mM zinc sulfate in the drinking water. Plasma IGF-I and BP-3 levels were determined by radioimmunoassay and western ligand blotting, respectively. Hepatic IGF-I and BP-3 mRNA levels were determined by slot-blot analysis. TG+Zn mice had higher plasma IGF-I (p < 0.05) and hepatic IGF-I mRNA (p < 0.05) levels as compared to TG-Zn, C+Zn and C-Zn mice. Plasma IGF-I and hepatic IGF-I mRNA levels in TG-Zn mice were not different from C+Zn and C-Zn mice. Removal of Zn decreased hepatic IGF-I mRNA levels to C levels in TG mice. Plasma BP-3 and hepatic BP-3 mRNA levels in TG+Zn mice were increased (p < 0.05) as compared to TG-Zn, C-Zn and C+Zn. Plasma BP-3 and hepatic BP-3 mRNA levels did not differ between TG-Zn, C-Zn and C+Zn mice. Expression of the transgene also increased the level of plasma BP-3 during pregnancy as compared to that observed for pregnant C mice. We conclude that oGH regulates IGF-I and BP-3 expression in the oMtla-oGH transgenic mouse model system.

Molecular genetics of the persistent müllerian duct syndrome: a study of 19 families

A rare form of familial male pseudohermaphroditism, the persistent Müllerian duct syndrome (PMDS) is characterized by persistence of uterus and Fallopian tubes in 46,XY phenotypic males and is ascribed to defects in the synthesis or action of anti-Müllerian hormone (AMH). Biologically, PMDS is heterogeneous: in some cases, bioactive AMH is normally expressed by testicular tissue while, in others, no AMH is produced, suggesting the possibility of an AMH gene mutation, several of which have already been described. Molecular analysis of the AMH gene has now been performed in 21 additional patients and their families. In 6 patients, with normal serum concentration of AMH, the AMH gene was normal or contained only polymorphisms and silent mutations, supporting the hypothesis that the condition is due to end-organ resistance. Nine novel mutations were discovered in the remaining subjects, with low or undetectable levels of serum AMH. These mutations, when present in homozygotes or compound heterozygotes, were associated with the PMDS phenotype, the same mutation never being observed in two different families. The three first exons of the AMH gene appear particularly mutation-prone, although they are less GC rich than the 2 last ones and code for the N-terminal part of the AMH protein, which is not in itself essential to bioactivity.

Anti-müllerian hormone and testosterone serum levels are inversely during normal and precocious pubertal development

Anti-Müllerian hormone (AMH), also called Müllerian inhibiting substance or factor, is produced by Sertoli cells from fetal life until puberty. In the present study, AMH, testosterone (T), LH, and FSH were measured by immunochemical methods in the serum of 50 boys with normal or delayed pubertal development, 4 patients with suspected androgen insensitivity, and 11 patients with either central (CPP) or gonadotropin-independent (GIPP) precocious puberty to investigate the hormonal regulatory mechanisms of AMH secretion at puberty. An inverse relationship between AMH and T levels was demonstrated. In boys with normal or delayed puberty with T concentrations below 6.7 nmol/L, AMH values were elevated (mean +/- SEM, 22.4 +/- 3.1 micrograms/L) and widely dispersed. In subjects with T levels over 6.7 nmol/L, AMH levels were uniformly low (3.4 +/- 0.5 micrograms/L), except in patients with suspected androgen insensitivity. No significant relationship was found between AMH and gonadotropin levels. Similar results were obtained in patients with either CPP or GIPP. Longitudinal studies were performed on four boys with CPP and two with GIPP before and after treatment. At the time of diagnosis, the T concentration was high, and AMH levels were usually low in CPP and GIPP patients alike. When appropriate treatment was initiated, the T concentration was normalized within 2-4 weeks, but restoration of prepubertal AMH levels required several months. Mature Sertoli cells were observed in testicular biopsies performed in three patients with untreated GIPP. Our results suggest that gonadotropins are not directly implicated in repression of AMH synthesis at puberty, but, rather, that the decrease in AMH production is the consequence of an androgen-mediated, long term, reversible chain of events leading to morphological and functional maturation of the Sertoli cells. Thus, the fall in serum AMH levels appears to be an excellent marker of Sertoli cell pubertal development.

Effects of octreotide on insulin-like growth factor I and metabolic indices in growth hormone-treated growth hormone-deficient patients

Animals studies have demonstrated that in addition to inhibiting growth hormone (GH) secretion octreotide inhibits in a direct manner hepatic or peripheral insulin-like growth factor I (IGF-I) generation. To test this hypothesis in humans we studied ten GH-deficient patients with frequent blood sampling during 38 h on two occasions. Regular GH therapy was discontinued 72 h prior to each study period. At the start of each study a subcutaneous (sc) injection of GH (3 IU/m2) was given (at 18.00 h). In a single-blinded crossover design, patients received a continuous sc infusion of either octreotide (200 micrograms/24 h) or placebo (saline). The pharmacokinetics of GH were similar on the two occasions. The area under the curve +/- SEM of serum GH was 142.5 +/- 53.6 micrograms.l-1 x h-1 (octreotide) and 144.8 +/- 41.8 micrograms.l-1 x h-1 (placebo), (p = 0.73); Cmax (microgram/l) was 12.5 +/- 1.47 (octreotide) and 12.8 +/- 1.42 (placebo) (p = 0.83), and Tmax (h) was 6.1 +/- 0.97 (octreotide) and 5.2 +/- 0.65 (placebo) (p = 0.49). Growth hormone administration was associated with an increase in serum IGF-I (microgram/l), which was identical during the two studies, from 85.3 +/- 19.4 to 174.25 +/- 30.3 for octreotide and from 97.0 +/- 26.4 to 158.8 +/- 28.2 for placebo. Mean IGF-I levels (microgram/l) were 138.2 +/- 25.1 (octreotide) and 134.5 +/- 28.6 (placebo) (p = 0.78). Similarly, the increase in IGF binding protein 3 (IGFBP-3) levels was identical. Mean IGFBP-3 levels (microgram/l) were 2303 +/- 323 (octreotide) and 2200 +/- 361 (placebo) (p = 0.25).(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of isolated growth hormone deficiency type IA due to GH-I gene deletion with recombinant human insulin-like growth factor I

Biosynthetic insulin-like growth factor I (IGF-I) was administered subcutaneously twice a day for one year to a patient with isolated growth hormone deficiency (IGHD) type IA with high titres of anti-GH antibody (up to 1:1,000,000). During IGF-I therapy he showed good linear growth without any side effects, such as hypoglycemia and anti-IGF-I antibody formation. Administration of IGF-I to IGHD type IA with poor response to GH therapy appears to have a beneficial effect on growth.

Insulin-like growth-factor binding protein (IGFBP) serum levels and hepatic IGFBP-2 and -3 mRNA expression in diabetic and insulin-treated swine (Sus scrofa)

1. Diabetes had no significant effect on IGFBP-3 message and serum levels however, subsequent insulin treatment caused more than a two-fold increase in both hepatic IGFBP-3 mRNA and serum levels above controls (P < 0.05). 2. The induction of diabetes in pigs significantly increased the steady state levels of IGFBP-2 mRNA in the liver of young swine (P < 0.05). 3. Both liver message and serum IGFBP-2 were reduced to control levels with insulin therapy. 4. We report here that in addition to its affects on IGFBP-2, insulin is involved in the regulation of IGFBP-3 expression.

Evaluation of plasma insulin-like growth factor-binding protein-3 as a potential predictor of preeclampsia

OBJECTIVE

Elevated growth factor activity in women with preeclampsia is caused by an acid- and heat-labile protein complex with a native molecular mass of 150,000. The major plasma insulin-like growth factor-binding protein-3 has identical molecular characteristics. We hypothesized that increased endothelial cell release or decreased proteolytic degradation of insulin-like growth factor-binding protein-3 in preeclampsia would result in higher circulating levels of insulin-like growth factors and hence in increased mitogenic activity.

STUDY DESIGN

Plasma insulin-like growth factor-binding protein-3 concentrations were determined by iodine-125 insulin-like growth factor-II radioligand blots of nonreducing gels in 16 normal and 16 preeclamptic patients collected from a prospective, case-control study. Enzyme-linked immunosorbent assays also were performed with a specific anti-insulin-like growth factor-binding protein-3 antiserum.

RESULTS

Insulin-like growth factor-binding protein-3 concentrations were not different between women with normal versus preeclamptic pregnancies (p = 0.23). Enzyme-linked immunosorbent assays confirmed these results in a subset of patients.

CONCLUSIONS

The findings indicate that insulin-like growth factor-binding protein-3 concentrations do not account for the elevated mitogenic activity observed in plasma from women with preeclampsia and are not a useful screening test for preeclampsia risk.

Insulin-like growth factor binding protein-3 protease activity in the urine of children with chronic renal failure

The insulin-like growth factors, IGF-1 and IGF-II, are polypeptides that potentiate cellular growth. In addition to binding to specific cell surface receptors, the IGFs bind with high affinity to a family of proteins, the insulin-like growth factor binding proteins (IGFBPs). Serum and urine IGFBP patterns are altered in individuals with chronic renal failure (CRF). We recently reported that the urinary IGFBP pattern of CRF patients is unique for increased insulin-like growth factor binding protein-1 (U-IGFBP-1) levels. In this study, we used western ligand blotting (WLB), western immunoblotting (WIB), and radioimmunoassay (RIA) to further evaluate serum and urine IGFBP profiles of children with CRF (n = 14). Five patients with CRF displayed decreased serum IGFBP-3 profiles by WLB. Serum IGFBP-3 WIB profiles were remarkable for 30- and 20-kDa fragments of IGFBP-3 not seen in control serum. Serum IGFBP-3 levels, as determined by RIA, were slightly elevated. Serum levels of IGFBP-2 also were increased, although not at a level reaching statistical significance. WLB of CRF urine revealed a large increase in U-IGFBP-1 and a complete absence of urinary IGFBP-3. Recent studies of serum from pregnant women and seminal plasma have demonstrated a similar absence of intact IGFBP-3, due to the presence of a specific IGFBP-3 protease. To evaluate whether an IGFBP-3 protease accounts for the absence of intact U-IGFBP-3 in children with CRF, urine and serum samples from individuals with CRF and controls were tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Production of interleukin 6, leukemia inhibitory factor and granulocyte-macrophage colony stimulating factor by peripheral blood mononuclear cells in Fanconi's anemia

The aim of this study was to test the in vitro cytokine production by peripheral blood mononuclear cells (PBMCs) in patients with Fanconi's anemia (FA). Phytohemagglutinin (PHA)-stimulated PBMCs from 21 patients with FA were studied for their ability to produce interleukin 6 (IL-6), leukemia inhibitory factor (LIF) and granulocyte-macrophage colony stimulating factor (GM-CSF). Enzymatic immunoassay (EIA) was used for both IL-6 and LIF, while GM-CSF was evaluated in a highly sensitive biological assay provided by GM-CSF-dependent M-07e cells. A significant decrease of IL-6 was detected in 9 out of 11 FA patients compared with five normal donors, while similar amounts of LIF were produced from 21 FA patients and 21 healthy subjects. A drastic increase of active GM-CSF was documented in PHA-stimulated PBMC-conditioned medium in all 18 FA patients tested. Since IL-6 and GM-CSF play an important role in maintaining basal hemopoiesis, our results suggest that an abnormal cytokine network may be involved in the pathogenesis of FA pancytopenia.

Pregnancy associated increase in differentiation-stimulating factor (D-factor)/leukemia inhibitory factor (LIF)-binding substance(s) in mouse serum

Differentiation-stimulating factor (D-factor)/leukemia inhibitory factor (LIF) is known to have multiple biological activities besides induction of differentiation of mouse myeloid leukemia M1 cells. Little is known about how its activities are regulated in vivo, but it has been suggested to play a regulatory role in the mechanisms involved in development of mice. In this study, we found that a single class of D-factor-binding substance is present in normal mouse serum and that it increases transiently in the late stage of pregnancy. It inhibits the induction of differentiation of mouse myeloid leukemic M1 cells by D-factor by blocking the binding of this factor to the cells. It is a heat-labile protein with an apparent molecular weight of 130,000-150,000. The binding of 125I-D-factor to the substance is specific since it was inhibited by excess unlabeled D-factor, but not by interleukin 6 or interferon gamma. The dissociation constant of the binding substance for mouse D-factor in normal mouse serum is 6.6-9.4 nM. In the late stage of pregnancy, the amount of the D-factor-binding substance in the serum apparently increases about 30-fold. These results suggest that the D-factor-binding substance regulates the activity of D-factor during embryonic development of mice.