Efficacy and safety of intrathecal pemetrexed for TKI-failed leptomeningeal metastases from EGFR+ NSCLC: an expanded, single-arm, phase II clinical trial

BACKGROUND

This study aimed to evaluate the efficacy and safety of intrathecal pemetrexed (IP) for treating patients with leptomeningeal metastases (LM) from non-small-cell lung cancer (NSCLC) who progressed from epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) treatment in an expanded, prospective, single-arm, phase II clinical study (ChiCTR1800016615).

PATIENTS AND METHODS

Patients with confirmed NSCLC-LM who progressed from TKI received IP (50 mg, day 1/day 5 for 1 week, then every 3 weeks for four cycles, and then once monthly) until disease progression or intolerance. Objectives were to assess overall survival (OS), response rate, and safety. Measurable lesions were assessed by investigator according to RECIST version 1.1. LM were assessed according to the Response Assessment in Neuro-Oncology (RANO) criteria.

RESULTS

The study included 132 patients; 68% were female and median age was 52 years (31-74 years). The median OS was 12 months (95% confidence interval 10.4-13.6 months), RANO-assessed response rate was 80.3% (106/132), and the most common adverse event was myelosuppression (n = 42; 31.8%), which reversed after symptomatic treatment. The results of subgroup analysis showed that absence of brain parenchymal metastasis, good Eastern Cooperative Oncology Group score, good response to IP treatment, negative cytology after treatment, and patients without neck/back pain/difficult defecation had longer survival. Gender, age, previous intrathecal methotrexate/cytarabine, and whole-brain radiotherapy had no significant influence on OS.

CONCLUSIONS

This study further showed that IP is an effective and safe treatment method for the EGFR-TKI-failed NSCLC-LM, and should be recommended for these patients in clinical practice and guidelines.

A space-confined strategy towards stable α/β-Bi2O3 heterojunction anode for high-energy aqueous battery

It is very necessary to design a high-capacity and stable Bi2O3 anode for nickel-bismuth (Ni//Bi) batteries. In this work, a stable α- and β- phase Bi2O3 heterojunction nanocomposite (α/β - Bi2O3) was successfully prepared via a simple "space-confined" strategy and it was used as a superior anode for nickel-bismuth (Ni//Bi) battery. The α/β-Bi2O3 obtained by using MCM-41 as a space-confined template possesses a stable structure and enhanced charge transfer capability. Such superior traits vest the designed α/β-Bi2O3 electrode with high specific capacity (235 mAh g-1 at 1 A g-1), extraordinary rate performance (137 mAh g-1 at 40 A g-1, and ∼58% capacity retention vs 1 A g-1), and excellent cyclic durability (75% capacity retention after 5000 cycles). Such performances are far superior to that of mono-phase α-Bi2O3 and β-Bi2O3 electrodes. Furthermore, an excellent Ni//Bi battery with outstanding energy density (∼155 Wh kg-1) and long cycle life was assembled using the obtained α/β-Bi2O3 electrode and a NiC2O4 electrode as anode and cathode, respectively (NiC2O4//α/β-Bi2O3). This work opens a new alternative strategy for the rational design of efficient electrodes for reliable aqueous rechargeable batteries.

An Innovative Bi12 SiO20 Multistage Cubic Nanospheres Cathode for High-Performance Bi//Zn Battery

Alkaline Bi//Zn batteries with superb safety, low cost, and high power density are promising candidates for large-scale electrical energy storage. However, their developments are severely limited by the Bi-based cathode as the unsatisfying capacity and cycle life. Herein, an innovative multistage cubic nanospheres Bi₁₂ SiO₂₀ (MCS-Bi₁₂ SiO₂₀ ) is successfully synthesized by a simple calcination method, which shows excellent energy storage performances of superior specific capacity (294 mAh g^-1 at 0.5 A g^-1 ) and outstanding rate capability (134 mAh g^-1 at 12 A g^-1 ). When coupled with Zn anode a superior MCS-Bi₁₂ SiO₂₀ //Zn is fabricated, which delivers a high energy density of 247.5 Wh kg^-1 at the power density of 375 W kg^-1 . Additionally, the MCS-Bi₁₂ SiO₂₀ //Zn battery shows excellent cycle life, which reserves more than 100 % of its original capacity after 5000 cycles. Such performance is higher than previously reported Bi//Zn battery and most other Zn batteries. This is the first example of using Bi₁₂ SiO₂₀ as cathode for RAZBs, which may provide highly promising material towards better Bi//Zn battery.

Synthesis, Crystal Structure, and Nonlinear Optical Property of an Anhydrous Sulfate KTb(SO4)2

A new alkali metal-rare earth metal anhydrous sulfate, KTb(SO₄)₂ (KTSO), was synthesized by a hydrothermal method. It crystallized in the non-centrosymmetric (NCS) orthorhombic space group P2₁2₁2₁ with cell parameters a = 5.43950(10), b = 8.8579(3), c = 13.3962(4), Z = 2. Its structure is composed of [KO₁₁], [TbO₈], and [SO₄] groups, which are interconnected to constitute a one-dimensional (1D) chain, and then further linked to construct a three-dimensional (3D) network structure through [SO₄] units. The results of the powder frequency doubling test show that KTb(SO₄)₂ has a phase-matching second-order nonlinear optical effect of 0.3 times that of KH₂PO₄ (KDP). The measured birefringence of the crystal (0.01) agrees well with the calculated value (0.019). Meanwhile, its infrared and ultraviolet spectrum and thermal properties were studied, respectively. Its optical properties and band gap structure are studied by theoretical calculation. This work provides a NCS structure of anhydrous sulfates and offers guidance for further exploration of new anhydrous sulfates.

Syntheses, structure and properties of a new series of organic-inorganic Hg-based halides: adjusting halogens resulted in huge performance mutations

Three new organic-inorganic hybrid perovskite (OIHP) halides, [N(CH3)4]HgCl0.63Br2.37 (I), [N(CH3)4]HgBrI2 (II) and [N(CH3)4]HgCl0.45I2.55 (III), were synthesized by a hydrothermal reaction. They feature different crystal structures, in which both II and III are isomorphic and contain a one-dimensional chain with organic cation [N(CH3)4]+ interspersed in the space, whereas II has a similar one-dimensional chain but significantly different spatial arrangement due to the enhanced hydrogen bond interaction. The experimental results show that the divergent second-order nonlinear optical (NLO) effect from Br(Cl) to I and the arrangement of anion groups change dramatically from the presence of hydrogen bonds to the absence of hydrogen bonds, leading to a sharply increased NLO response of II and III (18 and 25 times that of I) compared with that of I. Moreover, the phase matching ability disappeared and the band gap decreased significantly. Meanwhile, a high temperature phase transition was observed in II and III, which is rare in common OIHPs. All these results indicate that the regulation of halogen bonds plays a crucial role in the structural and property mutations of OIHP halides.

Acentric Organic-Inorganic Hybrid Halide [N(CH3)4]2HgBr2I2 Featuring an Isolated [HgBr2I2]2- Tetrahedron and Second-Order Nonlinearity

A new hybrid compound [N(CH₃)₄]₂HgBr₂I₂, obtained by a hydrothermal reaction, crystallized in the noncentrosymmetric space group P2₁2₁2₁. Its structure contains an isolated asymmetric [HgBr₂I₂]^2- tetrahedron with net polarization, connected by hydrogen bonds to form pseudo-one-dimensional chain structures. Moreover, its optical band gap, nonlinear optical (NLO) property, fluorescence property, and thermal property were characterized in detail. A rare high-temperature phase transition was observed in the compound. In addition, theoretical calculations were performed to elaborate the relation between electronic state, band structure, and their nonlinear optical response. These results indicate that [N(CH₃)₄]₂HgBr₂I₂ is a new potential candidate for future photoelectronic applications in fluorescence and nonlinear optics.

MiR-130a regulating the biological function of colon cancer by targeting inhibition of PTEN

OBJECTIVE

To investigate the expression of miR-130a in human colon cancer patients and its specific mechanism of regulating the biological function of colon cancer cells.

PATIENTS AND METHODS

Cancer tissues, paracancerous tissues, and serum samples of 40 colon cancer patients who underwent surgery in The Second Affiliated Hospital of Qiqihar Medical University from May 2018 to March 2019 were collected, and 40 healthy volunteers who received physical examination in The Second Affiliated Hospital of Qiqihar Medical University were collected. Real Time-quantitative Polymerase Chain Reaction (qRT-PCR) was used to detect the expression of miR-130a. Human colon cancer cell was divided into miR-130a mimic group, miR-130a inhibitor group, mimic NC (negative control), and inhibitor NC group. QRT-PCR was used to detect the expression of miR-130a, and MTT assay, colony formation assay, cell scratch assay, transwell assay were performed to detect cell viability, proliferation, migration, and invasion ability.

RESULTS

Compared with adjacent tissues, the expression of miR-130a was significantly increased in colon cancer tissues (p=0.0125); the expression of miR-130a in transfected miR-130a mimic group was higher than that in NC group, but the expression in transfected miR-130a inhibitor group was significantly lower than that in NC group; overexpression of miR-130a significantly increased cell viability, proliferation, migration, and invasion of colon cancer cells, while knockdown of miR-130a significantly inhibited colon cancer cell biological activity; target prediction, qRT-PCR, and Western blot assays showed that miR-130a participated in the development and progression of colon cancer by targeting inhibition of PTEN expression.

CONCLUSIONS

The expression of miR-130a in serum and cancer tissues of colon cancer patients is significantly increased, and it can regulate the biological function of colon cancer cells by inhibiting the expression of target gene PTEN. Knockdown of miR-130a may be used as a new clinical treatment for colon cancer.

Nonlinear organic–inorganic halide hybrids containing unprecedented linear [MIX2]− coordination units and quasi-two-dimensional lone pairs

A first example of monovalent-metal-based hybrid halides [N(CH₃)₄]MCl₂ (M = Ga⁺, In⁺) with zero-dimensional configuration containing unprecedented linear [GaCl₂]/[InCl₂] units have been designed and synthesized.

Boosting Zn-Ion Energy Storage Capability of Hierarchically Porous Carbon by Promoting Chemical Adsorption

The construction of advanced Zn-ion hybrid supercapacitors (ZHSCs) with high energy density is promising but still challenging, especially at high current densities. In this work, a high-energy and ultrastable aqueous ZHSC is demonstrated by introducing N dopants into a hierarchically porous carbon cathode for the purpose of enhancing its chemical adsorption of Zn ions. Experimental results and theoretical simulations reveal that N doping not only significantly facilitates the chemical adsorption process of Zn ions, but also greatly increases its conductivity, surface wettability, and active sites. Consequently, the as-fabricated aqueous ZHSC based on this N-doped porous carbon cathode displays an exceptionally high energy density of 107.3 Wh kg^-1 at a high current density of 4.2 A g^-1 , a superb power density of 24.9 kW kg^-1 , and an ultralong-term lifespan (99.7% retention after 20 000 cycles), substantially superior to state-of-the-art ZHSCs. Particularly, such a cathode also leads to a quasi-solid-state device with satisfactory energy storage performance, delivering a remarkable energy density of 91.8 Wh kg^-1 . The boosted energy storage strategy by tuning the chemical adsorption capability is also applicable to other carbon materials.

Structural and defect engineering of cobaltosic oxide nanoarchitectures as an ultrahigh energy density and super durable cathode for Zn-based batteries

Ordered mesoporous and oxygen-vacancy are demonstrated to significantly improve the electrochemical performance of Co₃O₄. Capitalizing on the optimized M-Co₃O_4–x cathode, the ZBB exhibits ultrahigh energy density and extraordinary cycling stability.

The key challenges of aqueous Zn-based batteries (ZBBs) are their unsatisfactory energy density and poor lifespan, mainly arising from the low capacity and irreversibility of the cathode materials. Herein, a three-dimensional (3D) ordered mesoporous nanoarchitecture cobaltosic oxide (M-Co₃O₄) with rich oxygen vacancies (M-Co₃O_4–x) is reported as a new promising advanced cathode material for rechargeable ZBBs. The experimental results and DFT calculations reveal that the energy storage capacity is significantly enhanced by the synergistic effect of mesopores and oxygen vacancies. Benefiting from the merits of a substantially fast ion diffusion channel, high electrical conductivity, large active surface area, strong OH^– adsorption capacity and stable structure, the fabricated M-Co₃O_4–x//Zn battery delivers a remarkable capacity of 384 mA h g^–1 at 1.0 A g^–1 which even rises up to 420 mA h g^–1 after cycling activation with an ultrahigh energy density of 722.4 W h kg^–1 (based on the weights of the cathode active material), which outperforms most of the previously reported aqueous ZBBs. More impressively, the M-Co₃O_4–x//Zn battery exhibits extraordinary cycling stability, both at 1 A g^–1 and 10 A g^–1 without any decay of capacity after 6000 and 60 000 cycles, respectively, and such high cycling stability is reported for the first time in ZBBs. The ultrahigh energy and superlong lifespan of aqueous ZBBs could make it satisfy some practical energy demands.

Learning from other people's fear: amygdala-based social reference learning in social anxiety disorder

BACKGROUND

Social anxiety disorder involves fear of social objects or situations. Social referencing may play an important role in the acquisition of this fear and could be a key determinant in future biomarkers and treatment pathways. However, the neural underpinnings mediating such learning in social anxiety are unknown. Using event-related functional magnetic resonance imaging, we examined social reference learning in social anxiety disorder. Specifically, would patients with the disorder show increased amygdala activity during social reference learning, and further, following social reference learning, show particularly increased response to objects associated with other people's negative reactions?

METHOD

A total of 32 unmedicated patients with social anxiety disorder and 22 age-, intelligence quotient- and gender-matched healthy individuals responded to objects that had become associated with others' fearful, angry, happy or neutral reactions.

RESULTS

During the social reference learning phase, a significant group × social context interaction revealed that, relative to the comparison group, the social anxiety group showed a significantly greater response in the amygdala, as well as rostral, dorsomedial and lateral frontal and parietal cortices during the social, relative to non-social, referencing trials. In addition, during the object test phase, relative to the comparison group, the social anxiety group showed increased bilateral amygdala activation to objects associated with others' fearful reactions, and a trend towards decreased amygdala activation to objects associated with others' happy and neutral reactions.

CONCLUSIONS

These results suggest perturbed observational learning in social anxiety disorder. In addition, they further implicate the amygdala and dorsomedial prefrontal cortex in the disorder, and underscore their importance in future biomarker developments.

Implementation hurdles of an interactive, integrated, point-of-care computerised decision support system for hospital antibiotic prescription

Antimicrobial stewardship is used to combat antimicrobial resistance. In Singapore, a tertiary hospital has integrated a computerised decision support system, called Antibiotic Resistance Utilisation and Surveillance-Control (ARUSC), into the electronic inpatient prescribing system. ARUSC is launched either by the physician to seek guidance for an infectious disease condition or via auto-trigger when restricted antibiotics are prescribed. This paper describes the implementation of ARUSC over three phases from 1 May 2011 to 30 April 2013, compared factors between ARUSC launches via auto-trigger and for guidance, examined factors associated with acceptance of ARUSC recommendations, and assessed user acceptability. During the study period, a monthly average of 9072 antibiotic prescriptions was made, of which 2370 (26.1%) involved ARUSC launches. Launches via auto-trigger comprised 48.1% of ARUSC launches. In phase 1, 23% of ARUSC launches were completed. This rose to 38% in phase 2, then 87% in phase 3, as escapes from the ARUSC programme were sequentially disabled. Amongst completed launches for guidance, 89% of ARUSC recommendations were accepted versus 40% amongst completed launches via auto-trigger. Amongst ARUSC launches for guidance, being from a medical department [adjusted odds ratio (aOR)=1.20, 95% confidence interval (CI) 1.04-1.37] and ARUSC launch during on-call (aOR=1.81, 95% CI 1.61-2.05) were independently associated with acceptance of ARUSC recommendations. Junior physicians found ARUSC useful. Senior physicians found ARUSC reliable but admitted to having preferences for antibiotics that may conflict with ARUSC. Hospital-wide implementation of ARUSC encountered hurdles from physicians. With modifications, the completion rate improved.

Non-Linear Optical Polymers for Active Optical Devices

Second order non-linear optical (NLO) polymers have been the focus of intense research effort in recent years [1]. This effort is justified by the potential value of these materials in a range of attractive optical signal processing applications with lower device costs and enhanced device performance.

Effect of a tight necktie on intraocular pressure

AIM

To evaluate the effect of a tight necktie on intraocular pressure (IOP) measurement using Goldmann applanation tonometry.

METHODS

40 eyes of 20 normal subjects and 20 open angle glaucoma patients (all male) were enrolled. IOP was measured with an open shirt collar, 3 minutes after placing a tight necktie, and 3 minutes after loosening it. All measurements were made by the same examiner.

RESULTS

Mean IOP in normal subjects increased by 2.6 (SD 3.9) mm Hg (p=0.008, paired t test; range -3 to +14 mm Hg) and in glaucoma patients by 1.0 (1.8) mm Hg (p=0.02, paired t test; range -2 to +4.5 mm Hg). In normal subjects, IOP in 12 eyes was increased by >/=2 mm Hg and in seven eyes by >/=4 mm Hg. In glaucoma patients, IOP in six eyes was increased by >/=2 mm Hg and in two eyes by >/=4 mm Hg.

CONCLUSION

A tight necktie increases IOP in both normal subjects and glaucoma patients and could affect the diagnosis and management of glaucoma.

Umbilical threonine uptake during maternal threonine infusion in sheep

OBJECTIVE

The infusion into the maternal circulation of amino acid solutions failed to increase umbilical threonine (THR) uptake above normal even when THR was present in the infusate at a relatively high concentration. The purpose of the present study was to determine whether umbilical THR uptake can be increased by infusing a THR solution that does not contain any other amino acids.

STUDY DESIGN

Five pregnant sheep (130+/-1.0 days after conception) were infused for 2h with a threonine solution (4.4+/-0.2 micromol.kg(-1).min(-1)). Plasma amino acids, glucose and lactate, hematocrit, blood O(2) content in maternal arterial, uterine venous, umbilical arterial and venous blood were measured. Uterine and umbilical blood flows were measured before and during the infusion and were used to calculate uterine and umbilical uptakes. Maternal and foetal plasma insulin and glucagon concentrations were also measured.

RESULTS

The THR infusion increased maternal plasma THR (904 vs 236 microM, P< 0.001), foetal plasma THR (539 vs 334 microM, P< 0.01), and both uterine (20.4 vs 4.7 micromol.min(-1).kg(-1)(fetalweight), P< 0.05) and umbilical (8.6 vs 3.8 micromol.min(-1).kg(-1)(fetalweight), P< 0.001) THR uptakes. The uterine-umbilical THR uptake difference increased significantly (11.8 vs 0.9 micromol.min(-1).kg(-1)(fetalweight), P< 0.05). There were significant (P< 0.001) decreases in the foetal arterial plasma concentrations of tyrosine and the branched chain amino acids, as well as in isoleucine umbilical uptake (P< 0.05). There was a significant increase in maternal plasma glucagon (P< 0.01).

CONCLUSION

A maternal THR infusion that causes a 3.8-fold increase in maternal plasma THR concentration above normal, with no significant increase in the concentration of other amino acids, leads to a 2.3-fold increase in umbilical THR uptake. This contrasts with the absence of a significant increase in umbilical THR uptake when THR was infused as part of an amino acid mixture in previous studies. The evidence supports the hypothesis that, in vivo, THR flux from placenta to foetus is mediated by a saturable, rate limiting transport system which is subject to inhibition by other neutral amino acids.

Effects of branched-chain amino acids on placental amino acid transfer and insulin and glucagon release in the ovine fetus

OBJECTIVE

Competition for placental amino acid transporters can affect the fetal supply of amino acids. Specifically, the branched-chain amino acids-isoleucine, leucine, and valine-may inhibit the transfer of other amino acids. This study was undertaken to determine the effect of branched-chain amino acids on the umbilical uptake of amino acids.

STUDY DESIGN

Six late-gestation ewes were infused sequentially for 2 hours with 3 different mixtures of amino acids: (1) one that was comparable to commercial parenteral nutrition preparations, (2) the same solution without branched-chain amino acids, and (3) branched-chain amino acids alone. Maternal and fetal blood samples were collected simultaneously for the determination of uterine and umbilical uptake values of amino acids, and for concentrations of arterial insulin, glucagon, glucose, and lactate before (control) and during (experimental) infusion.

RESULTS

Umbilical uptake of branched-chain amino acids increased significantly when they were present in the infusates. The fetal uptake of several other amino acids could be increased by increasing their maternal concentrations. Inhibition of umbilical uptake by branched-chain amino acids could be shown for threonine and methionine. The infusion of branched-chain amino acids alone did not affect maternal and fetal insulin or glucagon concentrations.

CONCLUSIONS

In late-gestation sheep, an increase in maternal plasma concentration of branched-chain amino acids led to increased branched-chain amino acid umbilical uptake, but branched-chain amino acids can also inhibit the transport of some amino acids to the fetus. Changes in fetal plasma concentration and uptake of branched-chain amino acid appear to have no significant effect on fetal insulin or glucagon.

Broussochalcone A, a potent antioxidant and effective suppressor of inducible nitric oxide synthase in lipopolysaccharide-activated macrophages

The antioxidant properties of broussochalcone A (BCA) and its effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophages were investigated in this study. BCA, isolated from Broussonetia papyrifera Vent., inhibited iron-induced lipid peroxidation in rat brain homogenate in a concentration-dependent manner with an IC(50) of 0.63 +/- 0.03 microM. It was as potent as butylated hydroxytoluene, a common antioxidant used for food preservation. In a diphenyl-2-picrylhydrazyl assay system, the radical-scavenging activity of BCA seemed to be more potent than that of alpha-tocopherol, its IC(0.200) being 7.6 +/- 0.8 microM. BCA could directly scavenge superoxide anion and hydroxyl radicals. These results indicated that BCA was a powerful antioxidant with versatile free radical-scavenging activity. On the other hand, we found that BCA suppressed NO production concentration-dependently, with an IC(50) of 11.3 microM in LPS-activated macrophages. This effect was not the consequence of a direct inhibitory action on the enzyme activity of inducible NO synthase (iNOS). Our results indicated that BCA exerts potent inhibitory effects on NO production, apparently mediated by its suppression of IkappaBalpha phosphorylation, IkappaBalpha degradation, nuclear factor-kappa B activation, and iNOS expression. Therefore, we conclude that the antioxidant activities of BCA and its inhibition of IkappaBalpha degradation and iNOS protein expression may have therapeutic potential, given that excessive free radicals and NO production have been associated with various inflammatory diseases.

An in vivo study of ovine placental transport of essential amino acids

Under normal physiological conditions, essential amino acids (EA) are transported from mother to fetus at different rates. The mechanisms underlying these differences include the expression of several amino acid transport systems in the placenta and the regulation of EA concentrations in maternal and fetal plasma. To study the relation of EA transplacental flux to maternal plasma concentration, isotopes of EA were injected into the circulation of pregnant ewes. Measurements of concentration and molar enrichment in maternal and fetal plasma and of umbilical plasma flow were used to calculate the ratio of transplacental pulse flux to maternal concentration (clearance) for each EA. Five EA (Met, Phe, Leu, Ile, and Val) had relatively high and similar clearances and were followed, in order of decreasing clearance, by Trp, Thr, His, and Lys. The five high-clearance EA showed strong correlation (r(2) = 0.98) between the pulse flux and maternal concentration. The study suggests that five of the nine EA have similar affinity for a rate-limiting placental transport system that mediates rapid flux from mother to fetus, and that differences in transport rates within this group of EA are determined primarily by differences in maternal plasma concentration.

Net amino acid flux across the fetal liver and placenta during spontaneous ovine parturition

The uptake and/or release of amino acids across the fetal liver and the placenta were studied in 8 pregnant sheep during the 5 days preceding delivery of the lamb. During spontaneous parturition, there was a significant decrease in fetal hepatic glutamine uptake, in fetal hepatic glutamate release and in placental glutamate uptake. The fetal plasma concentrations of glutamate, leucine, isoleucine, valine, phenylalanine, serine and tyrosine also decreased significantly in the 5 days preceding delivery. There was no significant net output of glucose from the fetal liver nor any change in net lactate uptake by the liver. During this same time period there was a significant increase in the fetal plasma cortisol concentration and a decrease in progesterone output by the pregnant uterus. The results are compared to the previously reported amino acid changes during dexamethasone-induced parturition.

Effect of dexamethasone on fetal hepatic glutamine-glutamate exchange

Intravenous infusion of dexamethasone (Dex) in the fetal lamb causes a two- to threefold increase in plasma glutamine and other glucogenic amino acids and a decrease of plasma glutamate to approximately one-third of normal. To explore the underlying mechanisms, hepatic amino acid uptake and conversion of L-[1-(13)C]glutamine to L-[1-(13)C]glutamate and (13)CO(2) were measured in six sheep fetuses before and in the last 2 h of a 26-h Dex infusion. Dex decreased hepatic glutamine and alanine uptakes (P < 0.01) and hepatic glutamate output (P < 0.001). Hepatic outputs of the glutamate (R(Glu,Gln)) and CO(2) formed from plasma glutamine decreased to 21 (P < 0.001) and 53% (P = 0.009) of control, respectively. R(Glu,Gln), expressed as a fraction of both outputs, decreased (P < 0.001) from 0.36 +/- 0.02 to 0.18 +/- 0.04. Hepatic glucose output remained virtually zero throughout the experiment. We conclude that Dex decreases fetal hepatic glutamate output by increasing the routing of glutamate carbon into the citric acid cycle and by decreasing the hepatic uptake of glucogenic amino acids.

Predictors of operative risk for coronary bypass operations in patients with left ventricular dysfunction

OBJECTIVES

The prevalence of ventricular dysfunction in patients undergoing coronary operations, as well as the prevalence of other risk factors in these patients, has been increasing. We identified the predictors of mortality and morbidity in patients with ventricular dysfunction to permit more accurate evaluation of risk and to direct future strategies to improve outcomes.

METHODS

Demographic, intraoperative, and outcome data were collected prospectively on 20,614 patients undergoing isolated coronary operations at our institution from 1982-1997. Multivariable regression analyses were used to identify the independent predictors of mortality and low-output syndrome.

RESULTS

Moderate ventricular dysfunction (ejection fraction, 20%-40%) was noted in 4107 (19.9%) patients, and severe dysfunction (ejection fraction, <20%) was noted in 680 (3.3%) patients. Patients with worse ventricular function had an increasing prevalence of other risk factors with time. Mortality decreased between the 1982-1986 and 1987-1991 cohorts but did not decrease further. Low-output syndrome was less common in the 1992-1997 cohort than in previous years. The predictors of mortality were ventricular dysfunction, age, reoperation, year of operation, urgency, female sex, and left main stenosis. Low-output syndrome was predicted by ventricular dysfunction, reoperation, year of operation, female sex, urgency, extensive coronary disease, age, left main stenosis, and symptom class.

CONCLUSIONS

Despite the increasing prevalence and risk profile of patients with ventricular dysfunction, mortality rates and incidence of low-output syndrome declined with time. Patients with severe dysfunction were at greatest risk when facing reoperation or urgent operation. Earlier intervention and more aggressive preoperative optimization may improve outcomes in these high-risk patients.

Contribution of branched-chain amino acids to uteroplacental ammonia production in sheep

The uteroplacental tissues are a principal site of ammonia production for the conceptus. The goal of this study was to examine the effect of the composition of maternal amino acid (AA) infusate on uteroplacental ammonia production. Seven pregnant ewes (126 +/- 1. 4 days gestation) were infused through the maternal femoral vein (duration 3.5 h, rate 240 ml per hour) with three solutions of AAs. The first infusate was comparable to commercial parenteral nutrition preparations, the second infusate contained the same solution without branched-chain AAs (BCAAs), and the third infusate contained only BCAAs. Blood samples were simultaneously collected from the maternal artery, uterine vein, fetal artery, and umbilical vein to determine plasma AA concentrations and whole blood ammonia concentrations, before (control) and 2 h after (experimental) the start of infusion. Uterine and umbilical blood flows were measured using the ethanol steady-state diffusion method. Results showed that fetal arterial and venous ammonia concentrations increased significantly after infusions with all AAs or only BCAAs, but not without BCAAs. Uteroplacental ammonia production increased in response to each of the three infusates. However, this increase was much greater when the BCAAs were present in infusates. We conclude that there is a significant contribution of BCAAs to the uteroplacental ammonia production. Maternal AA infusions containing BCAAs can result in increased fetal blood ammonia concentrations.

Umbilical amino acid uptake at increasing maternal amino acid concentrations: effect of a maternal amino acid infusate

OBJECTIVE

Our purpose was to establish whether, in normal human pregnancies, the maternal intravenous infusion of amino acids can increase fetal amino acid uptake and amino acid concentrations.

STUDY DESIGN

Twenty-six normal pregnancies were studied at the time of cesarean delivery (38-40 weeks' gestation). In 10 cases an amino acid formulation (Freamine 8.5% III, Baxter) was infused into a maternal vein before cesarean delivery. Maternal blood samples were obtained during the course of the study. Umbilical venous and arterial samples were obtained from the clamped segment of the cord. There were no differences between the 2 groups for fetal and placental weights and for fetal oxygenation and acid-base balance.

RESULTS

Maternal amino acid concentrations increased significantly in the group receiving infusions. Significant increases in umbilical venous concentrations were observed for most amino acids, except for histidine and threonine. The amino acid umbilical arteriovenous differences per mole of oxygen (AA/O(2) ratio) increased significantly for leucine, isoleucine, valine, methionine, phenylalanine, arginine, glycine, serine, alanine, and proline. There were no significant increases for lysine, histidine, and threonine.

CONCLUSION

An increase in maternal concentrations leads to an increase in the delivery of most amino acids to the fetus.

Fetal supply of amino acids and amino nitrogen after maternal infusion of amino acids in pregnant sheep

OBJECTIVE

The objective of the study was to determine whether a prolonged maternal infusion of amino acids would increase the umbilical uptake of amino acids and uteroplacental ammonia production.

STUDY DESIGN

Six pregnant sheep (134.5 2.3 days after conception) were infused for 12 hours overnight with an amino acid solution. Uterine and umbilical blood flows were measured with the ethanol steady-state diffusion technique before (control) and during (experimental) infusion. Plasma amino acid and whole-blood ammonia concentrations were measured.

RESULTS

After infusion, despite an increase in maternal arterial amino acid concentration, umbilical uptakes increased significantly only for branched-chain amino acids. Fetal ammonia concentrations and uteroplacental ammonia production increased moderately. Fetal nitrogen supply did not increase. Uterine nitrogen uptake represented 36% of the maternal nitrogen intake in the control period and 14% in the experimental period.

CONCLUSION

Prolonged maternal infusion of an amino acid solution was a relatively ineffective method of increasing fetal amino acid supply.

Mouse lactoferrin gene. Promoter-specific regulation by EGF and cDNA cloning of the EGF-response-element binding protein

Expression of the lactoferrin gene in a variety of tissues is regulated differentially. We have previously demonstrated that the lactoferrin gene is regulated by estrogen and mitogen in mouse uterus. The mouse lactoferrin gene responded to forskolin, cAMP, TPA and EGF stimulation via two adjacent enhancer elements, the CRE and EGFRE and collectively referred to as the Mitogen Response Unit (MRU). We found that CRE is responsible for forskolin, cAMP and TPA whereas EGFRE is for EGF stimulation. We examined the minimal promoter and enhancer elements of the mouse lactoferrin gene that are required for EGF induced transcriptional activation. We found that the CRE and noncanonical TATA box (ATAAA) are the minimal promoter elements for basal activity of the CAT reporter construct, whereas, the EGFRE is needed for an additional activity induced by EGF in transiently transfected human endometrial carcinoma RL95-2 cells (RL95-2). The EGFRE, however, did not function in heterologous promoters (SV 40 and TK). Therefore, EGF-stimulated lactoferrin gene activity is promoter specific in RL95-2 cells. Mutation made at either elements or insertion of extra nucleotides between the two elements, severely affected EGF-stimulated activity. Nuclear protein prepared from RL95-2 cells protected the EGFRE, CRE and noncanonical TATA from DNAase I digestion in a footprinting analysis. Nuclear protein which interacted with the CRE were previously identified as API and CREB. In this study, we isolated a cDNA clone from an RL95-2 expression library that encodes the EGFRE binding protein. Partial sequence of the cDNA clone revealed 100% nucleotide identity with a GC-box binding protein, BTEB2. Protein-protein interaction among the transcription factors could fine-tune the mouse lactoferrin expression in various tissues.

Uptake and transport by the ovine placenta of neutral nonmetabolizable amino acids with different transport system affinities

Placental uptake and transport of three nonmetabolizable amino acids with different reactivities for transport systems were studied in sheep under normal physiologic conditions. Methylaminoisobutyric acid (MeAIB), which has specific affinity for the sodium-dependent A system transporters, demonstrated placental concentrative uptake from the uterine and the umbilical circulations, but virtually no transport from mother to fetus. By contrast, aminoisobutyric acid (AIB) and aminocyclopentane-1-carboxylic acid (ACP), which have affinity for both sodium-dependent and sodium-independent transporters, demonstrated both concentrative uptake and transport from mother to fetus. ACP transport rate to the fetus was approximately twice the AIB transport rate. It is concluded that a neutral amino acid which interacts almost exclusively with the weakly reversible system A transporters may be transported rapidly into the placenta and may attain high concentrations within this organ but cannot escape from placenta to fetus down its own concentration gradient because the exit route is controlled by reversible amino acid transporters at the fetal surface of the placenta. Conversely, high affinity for reversible Na-independent transporters may be a necessary condition for the rapid transport of an amino acid from placenta to fetus.

A mutational analysis of binding interactions in an antigen-antibody protein-protein complex

Alanine scanning mutagenesis, double mutant cycles, and X-ray crystallography were used to characterize the interface between the anti-hen egg white lysozyme (HEL) antibody D1.3 and HEL. Twelve out of the 13 nonglycine contact residues on HEL, as determined by the high-resolution crystal structure of the D1.3-HEL complex, were individually truncated to alanine. Only four positions showed a DeltaDeltaG (DeltaGmutant - DeltaGwild-type) of greater than 1.0 kcal/mol, with HEL residue Gln121 proving the most critical for binding (DeltaDeltaG = 2.9 kcal/mol). These residues form a contiguous patch at the periphery of the epitope recognized by D1.3. To understand how potentially disruptive mutations in the antigen are accommodated in the D1.3-HEL interface, we determined the crystal structure to 1.5 A resolution of the complex between D1.3 and HEL mutant Asp18 --> Ala. This mutation results in a DeltaDeltaG of only 0.3 kcal/mol, despite the loss of a hydrogen bond and seven van der Waals contacts to the Asp18 side chain. The crystal structure reveals that three additional water molecules are stably incorporated in the antigen-antibody interface at the site of the mutation. These waters help fill the cavity created by the mutation and form part of a rearranged solvent network linking the two proteins. To further dissect the energetics of specific interactions in the D1.3-HEL interface, double mutant cycles were carried out to measure the coupling of 14 amino acid pairs, 10 of which are in direct contact in the crystal structure. The highest coupling energies, 2.7 and 2.0 kcal/mol, were measured between HEL residue Gln121 and D1.3 residues VLTrp92 and VLTyr32, respectively. The interaction between Gln121 and VLTrp92 consists of three van der Waals contacts, while the interaction of Gln121 with VLTyr32 is mediated by a hydrogen bond. Surprisingly, however, most cycles between interface residues in direct contact in the crystal structure showed no significant coupling. In particular, a number of hydrogen-bonded residue pairs were found to make no net contribution to complex stabilization. We attribute these results to accessibility of the mutation sites to water, such that the mutated residues exchange their interaction with each other to interact with water. This implies that the strength of the protein-protein hydrogen bonds in these particular cases is comparable to that of the protein-water hydrogen bonds they replace. Thus, the simple fact that two residues are in direct contact in a protein-protein interface cannot be taken as evidence that there necessarily exists a productive interaction between them. Rather, the majority of such contacts may be energetically neutral, as in the D1.3-HEL complex.

Production and utilization of amino acids by ovine placenta in vivo

Uterine and umbilical uptakes of plasma amino acids were measured simultaneously in eighteen singleton pregnant ewes at 130 +/- 1 days gestation for the purpose of establishing which amino acids are produced or used by the uteroplacenta under normal physiological conditions and at what rates. The branched-chain amino acids (BCAA) had uterine uptakes significantly greater than umbilical uptakes. Net uteroplacental BCAA utilization was 8.0 +/- 2.5 mumol.kg fetus-1.min-1 (P < 0.005) and represented 42% of the total BCAA utilization by fetus plus uteroplacenta. There was placental uptake of fetal glutamate (4.2 +/- 0.3 mumol.kg fetus-1.min-1, P < 0.001) and no uterine uptake of maternal glutamate. Umbilical uptake of glutamine was approximately 61% greater than uterine uptake, thus demonstrating net uteroplacental glutamine production of 2.2 +/- 0.9 mumol.kg fetus-1.min-1 (P < 0.021). In conjunction with other evidence, these data indicate rapid placental metabolism of glutamate, which is in part supplied by the fetus and in part produced locally via BCAA transamination. Most of the glutamate is oxidized, and some is used to synthesize glutamine, which is delivered to the fetus. There was net uteroplacental utilization of maternal serine and umbilical uptake of glycine produced by the placenta. Maternal serine utilization and glycine umbilical uptake were virtually equal (3.14 +/- 0.50 vs. 3.10 +/- 0.46 mumol.kg fetus-1.min-1). This evidence supports the conclusion that the ovine placenta converts large quantities of maternal serine into fetal glycine.

Developmental exposure to diethylstilbestrol elicits demethylation of estrogen-responsive lactoferrin gene in mouse uterus

Alteration of DNA demethylation in five CpG sites (-547, -533, -475, -464, and -454) immediately upstream from the estrogen response element of lactoferrin promoter was determined in the uteri of immature (17-day-old) and mature (21- and 30-day-old) mice treated neonatally with DES. Only the CpG/-464 was found to be abnormally demethylated by diethylstilbestrol (DES) treatment in the mature uteri. This abnormal demethylation occurred in specific response to DES in neonatal mice, because DES injected into the 30-day-old mature mice did not demethylate CpG/-464. This site, however, remained methylated in the neonatally DES-treated/ovariectomized mice, indicating that this DES-elicited demethylation is under hormonal control. Thus, neonatal DES treatment appeared to imprint an abnormal, site-specific demethylation of CpG/-464, which requires ovarian hormones to occur in adult mice. Moreover, the demethylation was maintained in uterine tumors of the neonatally DES-treated mice. This mode of demethylation is reminiscent of uterine tumor formation, which also depends on both neonatal DES exposure and ovarian hormone stimulation in adulthood. Thus, neonatal DES treatment may induce tumor formation as well as demethylation through a common cellular process.

Promoter and species specific differential estrogen-mediated gene transcription in the uterus and cultured cells using structurally altered agonists

Certain types of estrogenic compounds have been shown to have tissue-specific actions. In addition, some tissues may exhibit differential gene regulation by agonists and antagonists. Our previous studies using structurally modified estrogenic molecules had indicated differential effects on specific estrogen responses, indicating that the activity of the estrogen receptor protein can be altered depending not only upon the structure of the bound ligand but also the regulated gene itself. The mechanism of differential induction, however, was not determined, and might involve altered binding to the estrogen response element (ERE), altered transcription, or post-transcriptional modification of gene products. Our previous studies indicated that differential induction by modified diethylstilbestrol (DES) agonists could not be accounted for by differences in ligand affinity for the estrogen receptor (ER) or differential binding of the ER to a consensus vitellogenin A2 (vit A2) ERE. To determine if this differential hormonal responsiveness was reflected at the level of transcription, we analyzed mouse uterine mRNA of several estrogen-responsive genes, including glucose-6-phosphate dehydrogenase (G6PD), ornithine decarboxylase (ODC) and lactoferrin, by Northern blot following injection with the modified agonists DES, indenestrol A (IA), indenestrol B (IB) and Z-pseudo DES (ZPD). All compounds induced the G6PD message, although IB and ZPD induced expression only transiently, while DES and IA maintained the message for 24 h. No difference in induction was seen for ODC message, which was induced equally by all the compounds. In contrast, lactoferrin, a highly estrogen-responsive gene, was induced only by DES and IA and not by the other agonists IB or ZPD, showing that the lactoferrin gene was differentially regulated by these compounds. To determine whether this difference was due to altered transcriptional activity, the mouse lactoferrin estrogen-responsive module (mERM) linked to a chloramphenicol acetyl transferase (CAT) reporter gene was tested in transfected cells. Using the mouse estrogen receptor in RL95 cells, DES and IA induced expression of CAT, but IB did not, confirming the differential response seen in vivo. To show whether this difference in transcription occurred because of altered binding to the lactoferrin ERE, which is not a perfect consensus ERE a gel shift assay was used to examine DNA binding of ER bound to the agonists. All ligands produced equivalent binding to the lactoferrin ERE suggesting that differential regulation was not a result of altered DNA binding. Taken together, these observations indicate that the differential induction of lactoferrin by these compounds occurs via altered activation of the transcriptional components unique to lactoferrin and is likely to involve altered interaction with co-activators. Surprisingly, unlike the mouse ER, the human estrogen receptor activated and induced expression of lactoferrin estrogen-responsive module-CAT with all the compounds. Mouse ER is also known to vary from the human ER in its activity with the triphenylethylene estrogen tamoxifen, which has agonist activity with the mouse ER but mixed antagonist/agonist activity with the human ER. The data show that human and mouse estrogen receptors are activated differently by this group of stilbestrol estrogen ligands when assayed on the lactoferrin response element, which is the first description of this type of gene and species specific difference. Lactoferrin gene regulation by estrogen receptor can be used as a model to study the mechanism of differential gene activation by different estrogen agonists and antagonists using a more physiological situation than commonly used with in vitro gene reporter systems.

Metabolic alterations in the fetal hepatic and umbilical circulations during glucocorticoid-induced parturition in sheep

Fetal hepatic amino acid metabolism has unique features in comparison to postnatal life. Thus, it seemed likely that this metabolism might be changed by the endocrine changes which precede birth. To explore the changes in placental and fetal carbohydrate and amino acid metabolism that occur during parturition, labor was induced in six ewes at 131 +/- 1 d gestation with a fetal infusion of dexamethasone. For purpose of chemical analysis, blood was withdrawn before and approximately 3 and 25 h from the start of the infusion from maternal arterial, uterine venous, umbilical venous, fetal arterial, and left hepatic venous catheters. Fetal oxygenation remained normal. At 25 h, both fetal and maternal arterial plasma glucose concentrations increased (p < 0.01 and p < 0.02, respectively) and umbilical glucose uptake decreased (p < 0.05). Fetal glutamate showed a significant reduction in its hepatic output (p < 0.05) with a concomitant reduction in fetal arterial plasma concentration (p < 0.05) and placental uptake (p < 0.01). Fetal plasma concentrations of several other amino acids were markedly increased. The reduction in placental glutamate uptake was temporally associated with a decline in progesterone release by the pregnant uterus. These data suggest the hypothesis that glutamate plays a role in integrating the complex changes in placental and fetal hepatic metabolism that occur during parturition.

Estrogenic effect on the expression of estrogen receptor, COUP-TF, and lactoferrin mRNA in developing mouse tissues

We have previously demonstrated that lactoferrin (LF) is a major estrogen-inducible protein in the mouse uterus. The increase of LF mRNA after estrogen treatment (> 300 fold) is the result of a complex interplay among transcription factors acting on the estrogen response element (ERE) of the LF gene. Two transcription factors-the estrogen receptor (ER) and the chicken ovalbumin upstream promoter transcription factor (COUP-TF)-play opposing roles in the estrogen responsiveness of the LF gene promoter-reporter constructs in transiently transfected human endometrial carcinoma cells. The ratio of ER/COUP-TF in the transfected cells appears to be critical for estrogen-stimulated LF gene promoter activity (Liu et al, 1993). In the current study, ER and COUP-TF mRNA levels are examined and related to LF mRNA expression in various mouse tissues, including the developing uterus with/without estrogen stimulation. Results show that LF mRNA and protein are expressed in various tissues during development, but the potent synthetic estrogen, diethylstilbestrol (DES), does not increase LF mRNA expression in nonreproductive tissues such as liver, spleen, and lung. In contrast, in developing neonatal reproductive tract tissues, DES increases LF mRNA and protein expression as previously reported in immature and mature uterine tissues. DES, however, did not affect ER and COUP-TF expression in developing uterine tissues. Although the uterus has a high ratio of ER/COUP-TF as compared to other tissues examined, COUP-TF may not be the only regulator for LF gene expression in this particular tissue since COUP-TF remains constant during development and following DES treatment. These data point to the complexity of differential expression of LF gene in estrogen responsive and nonresponsive tissues during development.

Promoter-specific activation of mouse lactoferrin gene by epidermal growth factor involves two adjacent regulatory elements

The mouse lactoferrin gene responded to forskolin, 12-O-tetradecanoyl phorbol-13-acetate, and epidermal growth factor (EGF) stimulation via two adjacent enhancer elements, the cAMP response element (CRE) and EGF response element (EGFRE), collectively referred to as the mitogen response unit. In this report, we examined the minimal promoter and enhancer elements of the mouse lactoferrin gene that are required for EGF-induced transcriptional activation. We found that the CRE and noncanonical TATA box (ATAAA) are the minimal promoter elements for basal activity of the chloramphenicol acetyltransferase (CAT) reporter construct whereas the EGFRE is needed for an additional activity induced by EGF in transiently transfected human endometrial carcinoma RL95-2 cells (RL95-2). The EGFRE, however, did not function in heterologous promoters [SV 40 and thymidine kinase (TK)]. Therefore, EGF-stimulated lactoferrin gene activity is promoter specific in RL95-2 cells. In transiently transfected cells, EGF and forskolin showed synergistic effects on the CAT reporter that contained both response elements. Mutation made at either element or insertion of extra nucleotides between the two elements severely affected EGF-stimulated activity. Nuclear protein prepared from RL95-2 cells formed three complexes (A, B, and C) with the oligonucleotides containing both EGFRE and CRE in electrophoretic mobility shift assay. A new complex (E) was detected with the nuclear protein of EGF-treated cells. By oligonucleotide competition experiments, we demonstrated that the complex E was generated by protein bound to CRE. EGF-induced binding activity could be abolished by calf intestinal alkaline phosphatase but not by the protein synthesis inhibitor, cycloheximide. Therefore, binding of a preexisting phosphoprotein to the CRE region could be one of the requirements for EGF-induced mouse lactoferrin gene promoter activity.

Evidence for intracellular partitioning of serine and glycine metabolism in Chinese hamster ovary cells

Serine hydroxymethyltransferase (SHMT) is the primary enzyme in the interconversion of serine and glycine. The roles of mitochondrial and cytosolic SHMT in the interconversion of serine and glycine were determined in two Chinese hamster ovary (CHO) cell lines that both contain cytosolic SHMT but either have (CHOm+) or lacK (CHOm-) mitochondrial SHMT. Mitochondrial SHMT activity was significantly reduced in CHOm- (0.24 +/- 0.11 nmol/min per mg of mitochondrial protein) compared with CHOm+ (3.21 +/- 0.66 nmol/min per mg of mitochondrial protein; P = 0.02) cells, whereas cytosolic SHMT activity was similar in CHOm- and CHOm+ cells (1.09 +/- 0.31 and 1.53 +/- 0.12 nmol/min per mg of cytosolic protein respectively; P = 0.57). In CHOm+ and CHOm- cells, the relative flux of glycine to serine measured with either [1-13C]- or [2-13C]-glycine was similar (CHOm-: 538 +/- 82 nmol/24 per mg of DNA; CHOm+: 616 +/- 88 nmol/24 h per mg of DNA; P = 0.42). In contrast, the relative flux of serine to glycine measured with [1-13C]serine was low in CHOm- cells (80 +/- 28 nmol/24 h per mg of DNA) compared with CHOm+ cells (3080 +/- 320 nmol/24 h per mg of DNA; P = 0.0001). The rate of glycine production determined by [1-(13)C]glycine dilution was lower in CHOm- (1200 +/- 200 nmol/24 h per mg of DNA) than CHOm+ (10200 +/- 1800 nmol/24 h per mg of DNA; P = 0.03) cells, whereas glycine utilization was similar in the two cell lines. Serine production was similar in the two cell lines but serine utilization was lower in CHOm- (3800 +/- 1200 mu mol/24 h per mg of DNA) than CHOm+ (6600 +/- 1000 nmol/24 h per mg of DNA; P = 0.0002) cells. Increasing the serine concentration in the medium resulted in an increase in glycine production in CHOm+ but not in CHOm- cells. Intracellular studies with [1-13C]serine confirm the findings of decreased glycine production from serine. In CHO cells there is partitioning of intracellular serine and glycine metabolism. Our data support the hypothesis that mitochondrial SHMT is the primary pathway for serine into glycine interconversion.

Mouse lactoferrin gene: a marker for estrogen and epidermal growth factor

Lactoferrin mRNA in the 21-day-old mouse uterus can be increased several hundredfold by estrogen. The physiological role of lactoferrin in mouse uterus is unclear; however, it can be a useful marker for the estrogen action in the uterus. The structural organization and the chromosome location of the lactoferrin gene are similar to members of the transferrin gene family. At the 5' flanking region of the lactoferrin gene, we have characterized two modules that respond to estrogen and growth factor stimulation. Each module is composed of either overlapping or multiple transcription factor-binding elements. The well-characterized estrogen and growth factor response modules in the mouse lactoferrin gene could serve as the foundation to understand the intricate molecular mechanisms of estrogen action and its relationship to growth factors.