Caloric restriction leads to druggable LSD1-dependent cancer stem cells expansion

Caloric Restriction (CR) has established anti-cancer effects, but its clinical relevance and molecular mechanism remain largely undefined. Here, we investigate CR's impact on several mouse models of Acute Myeloid Leukemias, including Acute Promyelocytic Leukemia, a subtype strongly affected by obesity. After an initial marked anti-tumor effect, lethal disease invariably re-emerges. Initially, CR leads to cell-cycle restriction, apoptosis, and inhibition of TOR and insulin/IGF1 signaling. The relapse, instead, is associated with the non-genetic selection of Leukemia Initiating Cells and the downregulation of double-stranded RNA (dsRNA) sensing and Interferon (IFN) signaling genes. The CR-induced adaptive phenotype is highly sensitive to pharmacological or genetic ablation of LSD1, a lysine demethylase regulating both stem cells and dsRNA/ IFN signaling. CR + LSD1 inhibition leads to the re-activation of dsRNA/IFN signaling, massive RNASEL-dependent apoptosis, and complete leukemia eradication in ~90% of mice. Importantly, CR-LSD1 interaction can be modeled in vivo and in vitro by combining LSD1 ablation with pharmacological inhibitors of insulin/IGF1 or dual PI3K/MEK blockade. Mechanistically, insulin/IGF1 inhibition sensitizes blasts to LSD1-induced death by inhibiting the anti-apoptotic factor CFLAR. CR and LSD1 inhibition also synergize in patient-derived AML and triple-negative breast cancer xenografts. Our data provide a rationale for epi-metabolic pharmacologic combinations across multiple tumors.

Aberrant activation of p53/p66Shc-mInsc axis increases asymmetric divisions and attenuates proliferation of aged mammary stem cells

Aging is accompanied by the progressive decline in tissue regenerative capacity and functions of resident stem cells (SCs). Underlying mechanisms, however, remain unclear. Here we show that, during chronological aging, self-renewing mitoses of mammary SCs (MaSCs) are preferentially asymmetric and that their progeny divides less frequently, leading to decreased number of MaSCs and reduced regenerative potential. Underlying mechanisms are investigated in the p66Shc-/- mouse, which exhibits several features of delayed aging, including reduced involution of the mammary gland (MG). p66Shc is a mitochondrial redox sensor that activates a specific p53 transcriptional program, in which the aging-associated p44 isoform of p53 plays a pivotal role. We report here that aged p66Shc-/- MaSCs show increased symmetric divisions, increased proliferation and increased regenerative potential, to an extent reminiscent of young wild-type (WT) MaSCs. Mechanistically, we demonstrate that p66Shc, together with p53: (i) accumulates in the aged MG, (ii) sustains expression of the cell polarity determinant mInscuteable and, concomitantly, (iii) down-regulates critical cell cycle genes (e.g.,: Cdk1 and Cyclin A). Accordingly, overexpression of p53/p44 increases asymmetric divisions and decreases proliferation of young WT MaSCs in a p66Shc-dependent manner and overexpression of mInsc restores WT-like levels of asymmetric divisions in aged p66Shc-/- MaSCs. Notably, deletion of p66Shc has negligible effects in young MaSCs and MG development. These results demonstrate that MG aging is due to aberrant activation of p66Shc, which induces p53/p44 signaling, leading to failure of symmetric divisions, decreased proliferation and reduced regenerative potential of MaSCs.

Utility of ultrasound assessment in management of pregnancies with preterm prelabor rupture of membranes

OBJECTIVES

To evaluate the utility of ultrasound markers in the management of pregnancies complicated by preterm prelabor rupture of membranes (PPROM) between 23 + 0 and 33 + 6 weeks' gestation, and to assess the ability of ultrasound markers to predict adverse neonatal outcomes.

METHODS

This was a retrospective cohort study of all patients with PPROM between 23 + 0 and 33 + 6 weeks' gestation and latency period (PPROM to delivery) > 48 h, who delivered before 34 weeks' gestation at a tertiary referral center between 2005 and 2017. All patients underwent a non-stress test daily and an ultrasound scan twice a week for assessment of amniotic fluid volume, biophysical profile (BPP) and umbilical artery (UA) pulsatility index (PI). In patients with suspected fetal growth restriction, fetal middle cerebral artery (MCA)-PI was also assessed and the cerebroplacental ratio (CPR) calculated. The last ultrasound examination performed prior to delivery was analyzed. We compared the characteristics and outcomes between women who were delivered owing to clinical suspicion of chorioamnionitis and those who were not delivered for this indication. The primary objective was to evaluate the utility of ultrasound in the management of patients with PPROM. The secondary objective was to assess the diagnostic performance of ultrasound markers (BPP score < 6, oligohydramnios, UA-PI > 95^th percentile, MCA-PI < 5^th percentile, CPR < 5^th percentile) for the prediction of composite adverse neonatal outcome, which was defined as the presence of one or more of: perinatal death, respiratory distress syndrome, periventricular leukomalacia, intraventricular hemorrhage Grade 3 or 4, necrotizing enterocolitis, hypoxic ischemic encephalopathy, neonatal sepsis or neonatal seizures.

RESULTS

A total of 504 women were included in the study, comprising 120 with suspected chorioamnionitis and 384 without. Women with suspected chorioamnionitis, compared with those without, were less likely to be nulliparous (34.2% vs 45.3%; P = 0.03) and more likely to have fever (50.8% vs 2.6%; P < 0.001) and be delivered by Cesarean section (69.2% vs 42.4%; P < 0.001), mainly owing to a history of previous Cesarean section (18.3% vs 9.1%; P = 0.005) and to having non-reassuring fetal heart rate tracings (32.5% vs 14.6%; P < 0.001). No significant differences were found between the two groups with regard to the median amniotic fluid volume, overall BPP score, BPP score < 6, MCA-PI or CPR. Median UA-PI was slightly higher in the suspected-chorioamnionitis group, yet the incidence of UA-PI > 95^th percentile was similar between the two groups. There was a higher incidence of composite adverse neonatal outcome in the group with suspected chorioamnionitis than in the group without (78.3% vs 64.3%, respectively; P = 0.004). However, on logistic regression analysis, none of the ultrasound markers evaluated was found to be associated with chorioamnionitis or composite adverse neonatal outcome, and they all had a poor diagnostic performance for the prediction of chorioamnionitis and composite adverse neonatal outcome.

CONCLUSIONS

Commonly used ultrasound markers in pregnancies complicated by PPROM were similar between women delivered for suspected chorioamnionitis and those delivered for other indications, and performed poorly in predicting composite adverse neonatal outcome. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Acute and chronic antiparkinsonian effects of the novel nociceptin/orphanin FQ receptor antagonist NiK-21273 in comparison with SB-612111

BACKGROUND AND PURPOSE

Nociceptin/orphanin FQ (N/OFQ) peptide (NOP) receptor antagonists have been proposed as a novel therapeutic approach to Parkinson's disease. Main limitations of previous studies were the use of structurally similar compounds and the evaluation of their acute effects only. We report here on the acute and long-term antiparkinsonian effects of the novel compound 2-[3-[4-(2-chloro-6-fluoro-phenyl)-piperidin-1-ylmethyl]-2-(morpholine-4-carbonyl)-indol-1-yl]-acetamide (NiK-21273) in comparison with the potent and selective NOP receptor antagonist SB-612111.

EXPERIMENTAL APPROACH

Basic pharmacological properties of NiK-21273 were studied in cell lines and isolated tissues (mouse and rat vas deferens). Antiparkinsonian effects were studied in reserpinized mice and 6-hydroxydopamine hemilesioned rats under both acute and chronic administration protocols.

KEY RESULTS

In vitro, NiK-21273 behaved as a potent (pA(2) 7.7) and selective NOP receptor antagonist. In vivo, it reduced hypokinesia in reserpinized mice at 0.1 and 1 but not 10 mg·kg(-1), whereas SB-612111 (0.01-1 mg·kg(-1)) provided a dose-dependent antiparkinsonian effect. NiK-21273 ameliorated motor performance in 6-hydroxydopamine hemilesioned rats at 0.5 and 5 but not 15 mg·kg(-1). SB-612111 replicated these effects in the 0.01-1 mg·kg(-1) range without loss of efficacy. Both antagonists synergized with L-DOPA at subthreshold doses. Chronic administration of NiK-21273 provided delayed improvement in baseline activity at 0.5 and 1.5 mg·kg(-1), although tolerance to the higher dose was observed. Conversely, SB-612111 (1 mg·kg(-1)) maintained its effects over time without modifying baseline activity.

CONCLUSIONS AND IMPLICATIONS

NOP receptor antagonists provide motor benefit in parkinsonism models although the 'therapeutic' window and long-term effects may vary between compounds.

Cellular heterogeneity during embryonic stem cell differentiation to epiblast stem cells is revealed by the ShcD/RaLP adaptor protein

The Shc family of adaptor proteins are crucial mediators of a plethora of receptors such as the tyrosine kinase receptors, cytokine receptors, and integrins that drive signaling pathways governing proliferation, differentiation, and migration. Here, we report the role of the newly identified family member, ShcD/RaLP, whose expression in vitro and in vivo suggests a function in embryonic stem cell (ESC) to epiblast stem cells (EpiSCs) transition. The transition from the naïve (ESC) to the primed (EpiSC) pluripotent state is the initial important step for ESCs to commit to differentiation and the mechanisms underlying this process are still largely unknown. Using a novel approach to simultaneously assess pluripotency, apoptosis, and proliferation by multiparameter flow cytometry, we show that ESC to EpiSC transition is a process involving a tight coordination between the modulation of the Oct4 expression, cell cycle progression, and cell death. We also describe, by high-content immunofluorescence analysis and time-lapse microscopy, the emergence of cells expressing caudal-related homeobox 2 (Cdx2) transcription factor during ESC to EpiSC transition. The use of the ShcD knockout ESCs allowed the unmasking of this process as they presented deregulated Oct4 modulation and an enrichment in Oct4-negative Cdx2-positive cells with increased MAPK/extracellular-regulated kinases 1/2 activation, within the differentiating population. Collectively, our data reveal ShcD as an important modulator in the switch of key pathway(s) involved in determining EpiSC identity.

Approach in glucocorticoid-induced osteoporosis prevention: results from the Italian multicenter observational EGEO study

Glucocorticoid-induced osteoporosis (GIO) is the most frequent cause of secondary osteoporosis. GIO is linked to glucocorticoids (GC) daily assumption with maximum effect within first months of treatment and decreasing to basal levels as the therapy is discontinued. In Italy, primary prevention of GIO is suggested when GC therapy (prednisone >5 mg/day or equivalent) is taken for longer than 3 months. Lazio GISMO (Italian Group for Study and Diagnosis of Bone Metabolism Diseases) group organized the GC and Osteoporosis Epidemiology study (EGEO) to evaluate physician's approach in preventing GIO. The study involved 19 osteoporosis centers. Patients taking long-term GC therapy were recruited and information collected: medical history and anthropometric data, GC therapy, primary disease, physician's specialty, osteopororosis screening, and pharmacological intervention. The study included 1334 patients. Mean age was 63 ± 13 yr; 243 (18%) patients had a history of falls from standing position in the previous 12 months, 78 (35%) vertebral fractures, 91 (41%) fractures other than vertebral, 27 (12%) femoral fractures, and 27 (12%) multiple sites fractures. The molecules of GC more often prescribed were prednisone and 6-metil prednisolone. One thousand and forty patients (78%) were taking GC for more than 6 months. GC therapy was prescribed more frequently by rheumatologists (62%). Antiosteoporotic drugs for GIO prevention were prescribed in 431 patients (32%). Among the patients, only 27% (360) received calcium and vitamin D supplements, and 39% (319) treated by rheumatologists received anti-resorptive drugs. In conclusion, our data show that in Italy, as already described elsewhere, only a small subpopulation of GC-treated patients was supported by an anti-osteoporotic therapy, indicating the need to further stimulate awareness of both patients and specialists, prescribing GC therapy, to an appropriate and prompt GIO prevention.

Comparison of HE4, CA125 and ROMA algorithm in women with a pelvic mass: correlation with pathological outcome

OBJECTIVE

The quality of first surgery is one of the most important prognostic factors in ovarian cancer patients. Pre-surgical distinction of benign and malignant pelvic mass plays a critical role in ovarian cancer management and survival. The aim of this study was to evaluate the clinical performance of ROMA algorithm and of CA125 and HE4 in the triage of patients with a pelvic mass undergoing surgery, in order to discriminate benign from malignant disease.

METHODS

Three hundred and forty-nine pre- and post-menopausal women, aged 18 years or older undergoing surgery because of a pelvic mass were enrolled: serum concentrations of CA125 and HE4 were determined and ROMA was calculated for each sample.

RESULTS

Median serum CA125 and HE4 levels were higher in patients with EOC compared to subjects with benign disease (p<0.0001). The resultant accuracy (using Receiver Operating Characteristics, ROC Area) values for HE4, CA125 and ROMA showed a good performance ranging from 89.8% for CA125 in pre-menopausal patients to 93.3% for ROMA in post-menopausal patients: AUC for ROMA resulted significantly higher in comparison to CA125 alone (93.3% vs 90.3%, p=0.0018) in post menopausal patients. A sub-analysis considering the 40 patients with endometrioid disease showed the highest accuracy of HE4 in these patients.

CONCLUSIONS

Data presented confirm the accuracy of HE4 and of the ROMA algorithm in the distinction of ovarian carcinoma from benign disease, with a trend towards better performance for ROMA than for CA125 alone, statistically significant in postmenopausal patients.

Differential cytogenomics and miRNA signature of the Acute Myeloid Leukaemia Kasumi-1 cell line CD34+38- compartment

The t(8;21) Acute Myeloid Leukaemia (AML) Kasumi-1 cell line with N822K KIT mutation, is a model system for leukemogenesis. As AML initiating cells reside in the CD34(+)CD38(-) fraction, we addressed the refined cytogenomic characterization and miRNA expression of Kasumi-1 cell line and its FACS-sorted subpopulations focussing on this compartment. By conventional cytogenetics, Spectral-Karyotyping and array-CGH the cytogenomic profile of Kasumi-1 cells evidenced only subtle regions differentially represented in CD34(+)CD38(-) cells. Expression profiling by a miRNA platform showed a set of miRNA differentially expressed in paired subpopulations and the signature of miR-584 and miR-182 upregulation in the CD34(+)CD38(-) fraction.

Biological and molecular heterogeneity of breast cancers correlates with their cancer stem cell content

Pathways that govern stem cell (SC) function are often subverted in cancer. Here, we report the isolation to near purity of human normal mammary SCs (hNMSCs), from cultured mammospheres, on the basis of their ability to retain the lipophilic dye PKH26 as a consequence of their quiescent nature. PKH26-positive cells possess all the characteristics of hNMSCs. The transcriptional profile of PKH26-positive cells (hNMSC signature) was able to predict biological and molecular features of breast cancers. By using markers of the hNMSC signature, we prospectively isolated SCs from the normal gland and from breast tumors. Poorly differentiated (G3) cancers displayed higher content of prospectively isolated cancer SCs (CSCs) than did well-differentiated (G1) cancers. By comparing G3 and G1 tumors in xenotransplantation experiments, we directly demonstrated that G3s are enriched in CSCs. Our data support the notion that the heterogeneous phenotypical and molecular traits of human breast cancers are a function of their CSC content.

Recurrent syncope in elderly patients and tilt test table outcome: the role of comorbidities

Syncope is a common disorder that can lead to serious consequences in the elderly. Tilt-test is a safe, useful specific tool to investigate recurrent syncope also in the elderly. Comorbidities and medication use, widely present in elderly patients, affecting the hemodynamic response, can influence the tilt-test outcome. The aim of this study was to evaluate the influence of these confounding factors on tilt-test results in elderly patients with recurrent syncope. We included in this study a consecutive group of 87 patients>75 years (82.1+/-4.3 years) with unexplained syncope. They underwent passive upright tilt-test. Heart rate an blood pressure were recorded using non-invasive devices. The patients were classified according to the modified Vasovagal Syncope International Study (VASIS). Comorbidities were measured with the geriatric index of comorbidities (GIC), which is a composite score taking into account both the number of diseases and their severity as measured by Greenfield's IDS. The tilt-test was positive in 22 patients. There were no significant differences in clinical characteristics, and medication use between the tilt-test negative and positive patients, except for the GIC score (1.12+/-0.5 vs. 2.42+/-0.48; p=0.001) and for a reduced number of medications in the former group (5.7+/-3.1 vs. 8.2+/-2.4; p=0.001). This study suggests that comorbidities and the number of medications could influence tilt test outcome.

The tumor suppressor p53 regulates polarity of self-renewing divisions in mammary stem cells

Stem-like cells may be integral to the development and maintenance of human cancers. Direct proof is still lacking, mainly because of our poor understanding of the biological differences between normal and cancer stem cells (SCs). Using the ErbB2 transgenic model of breast cancer, we found that self-renewing divisions of cancer SCs are more frequent than their normal counterparts, unlimited and symmetric, thus contributing to increasing numbers of SCs in tumoral tissues. SCs with targeted mutation of the tumor suppressor p53 possess the same self-renewal properties as cancer SCs, and their number increases progressively in the p53 null premalignant mammary gland. Pharmacological reactivation of p53 correlates with restoration of asymmetric divisions in cancer SCs and tumor growth reduction, without significant effects on additional cancer cells. These data demonstrate that p53 regulates polarity of cell division in mammary SCs and suggest that loss of p53 favors symmetric divisions of cancer SCs, contributing to tumor growth.

Role for histone deacetylase 1 in human tumor cell proliferation

Posttranslational modifications of core histones are central to the regulation of gene expression. Histone deacetylases (HDACs) repress transcription by deacetylating histones, and class I HDACs have a crucial role in mouse, Xenopus laevis, zebra fish, and Caenorhabditis elegans development. The role of individual class I HDACs in tumor cell proliferation was investigated using RNA interference-mediated protein knockdown. We show here that in the absence of HDAC1 cells can arrest either at the G(1) phase of the cell cycle or at the G(2)/M transition, resulting in the loss of mitotic cells, cell growth inhibition, and an increase in the percentage of apoptotic cells. On the contrary, HDAC2 knockdown showed no effect on cell proliferation unless we concurrently knocked down HDAC1. Using gene expression profiling analysis, we found that inactivation of HDAC1 affected the transcription of specific target genes involved in proliferation and apoptosis. Furthermore, HDAC2 downregulation did not cause significant changes compared to control cells, while inactivation of HDAC1, HDAC1 plus HDAC2, or HDAC3 resulted in more distinct clusters. Loss of these HDACs might impair cell cycle progression by affecting not only the transcription of specific target genes but also other biological processes. Our data support the idea that a drug targeting specific HDACs could be highly beneficial in the treatment of cancer.

Recruitment of the histone methyltransferase SUV39H1 and its role in the oncogenic properties of the leukemia-associated PML-retinoic acid receptor fusion protein

Leukemia-associated fusion proteins establish aberrant transcriptional programs, which result in the block of hematopoietic differentiation, a prominent feature of the leukemic phenotype. The dissection of the mechanisms of deregulated transcription by leukemia fusion proteins is therefore critical for the design of tailored antileukemic strategies, aimed at reestablishing the differentiation program of leukemic cells. The acute promyelocytic leukemia (APL)-associated fusion protein PML-retinoic acid receptor (RAR) behaves as an aberrant transcriptional repressor, due to its ability to induce chromatin modifications (histone deacetylation and DNA methylation) and silencing of PML-RAR target genes. Here, we indicate that the ultimate result of PML-RAR action is to impose a heterochromatin-like structure on its target genes, thereby establishing a permanent transcriptional silencing. This effect is mediated by the previously described association of PML-RAR with chromatin-modifying enzymes (histone deacetylases and DNA methyltransferases) and by recruitment of the histone methyltransferase SUV39H1, responsible for trimethylation of lysine 9 of histone H3.

New method to detect histone acetylation levels by flow cytometry

BACKGROUND

Reversible histone acetylation affects chromatin structural organization, thus regulating gene expression and other nuclear events. Levels of histone acetylation are tightly modulated in normal cells, and alterations of their regulating mechanisms have been shown to be involved in tumorigenesis.

METHODS

We developed a new flow cytometric technique for detection of histone acetylation, based on a specific monoclonal antibody that recognizes acetylated histone tails. Bivariate analysis for histone acetylation levels and DNA were performed to study modulation of chromatin organization during the cell cycle and after induction of histone hyperacetylation by the histone deacetylase (HDAC) inhibitor trichostatin A (TSA). Histone acetylation and transcription levels were monitored during differentiation induced by retinoic acid alone or in combination with TSA. Blood samples from patients were analyzed with the described protocol to monitor the effects of HDAC inhibitors in vivo and validate the developed protocol for clinical usage.

RESULTS

Flow cytometric detection of acetylation status can successfully detect modifications induced by HDAC inhibitor treatment in vivo as demonstrated by analysis of various blood samples from patients treated with valproic acid. Changes in acetylation levels during the cell cycle demonstrated a reproducible increase in histone acetylation during the replication phase that was subsequently decreased at the G2M entrance, thus paralleling the behavior of DNA replication and transcriptional activity.

CONCLUSIONS

Multiparameter analysis of histone acetylation and expression of molecular markers, DNA ploidy, and/or cell cycle kinetics can provide a quick and statistically reliable tool for the diagnosis and evaluation of treatment efficacy in clinical trials using HDAC inhibitors.

Inhibitors of histone deacetylases induce tumor-selective apoptosis through activation of the death receptor pathway

Histone deacetylases (HDACs) regulate transcription and specific cellular functions, such as tumor suppression by p53, and are frequently altered in cancer. Inhibitors of HDACs (HDACIs) possess antitumor activity and are well tolerated, supporting the idea that their use might develop as a specific strategy for cancer treatment. The molecular basis for their selective antitumor activity is, however, unknown. We investigated the effects of HDACIs on leukemias expressing the PML-RAR or AML1-ETO oncoproteins, known to initiate leukemogenesis through deregulation of HDACs. Here we report that: (i) HDACIs induce apoptosis of leukemic blasts, although oncogene expression is not sufficient to confer HDACI sensitivity to normal cells; (ii) apoptosis is p53 independent and depends, both in vitro and in vivo, upon activation of the death receptor pathway (TRAIL and Fas signaling pathways); (iii) TRAIL, DR5, FasL and Fas are upregulated by HDACIs in the leukemic cells, but not in normal hematopoietic progenitors. These results show that sensitivity to HDACIs in leukemias is a property of the fully transformed phenotype and depends on activation of a specific death pathway.

Impairment of p53 acetylation, stability and function by an oncogenic transcription factor

Mutations of p53 are remarkably rare in acute promyelocytic leukemias (APLs). Here, we demonstrate that the APL-associated fusion proteins PML-RAR and PLZF-RAR directly inhibit p53, allowing leukemic blasts to evade p53-dependent cancer surveillance pathways. PML-RAR causes deacetylation and degradation of p53, resulting in repression of p53 transcriptional activity, and protection from p53-dependent responses to genotoxic stress. These phenomena are dependent on the expression of wild-type PML, acting as a bridge between p53 and PML-RAR. Recruitment of histone deacetylase (HDAC) to p53 and inhibition of p53 activity were abrogated by conditions that either inactivate HDACs or trigger HDAC release from the fusion protein, implicating recruitment of HDAC by PML-RAR as the mechanism underlying p53 inhibition.

HOME CARE PREVENTS COGNITIVE AND FUNCTIONAL DECLINE IN FRAIL ELDERLY

Today home health care (HHC) programs have been developed in numerous Western countries, in order to answer the questions regarding the care of frail elderly suffering from polypathologies and, therefore, being at high risk of disability. The HHC program of the Israelite Hospital of Rome has been planned as a complementary model, and not as a substitute of hospitalization, being able to offer flexible services, suitable for each elderly patient. The present study has established that taking care of old patients in their home allows us to prevent the deterioration of cognitive performance and functional impairments,as measured by the mini mental state examination (MMSE), the scales of activity of daily living (ADL), and the instrumental activity of daily living (IADL), respectively. We found considerable improvements also in the mood disorders during HHC, as measured by the geriatric depression scale (GDS). All psychometric tests were administered at the beginning of home care and after almost 1 year. Moreover, we formulated some questions regarding the quality of the offered services, and the answers revealed great satisfaction of both the patients and their caregivers.

Kit regulatory elements required for expression in developing hematopoietic and germ cell lineages

The Kit (White) gene encodes the transmembrane receptor of stem cell factor/Kit ligand (KL) and is essential for the normal development/maintenance of pluripotent primordial germ cells (PGCs), hematopoietic stem cells (HSCs), melanoblasts, and some of their descendants. The molecular basis for the transcriptional regulation of Kit during development of these important cell types is unknown. We investigated Kit regulation in hematopoietic cells and PGCs. We identified 6 DNase I hypersensitive sites (HS1-HS6) within the promoter and first intron of the mouse Kit gene and developed mouse lines expressing transgenic green fluorescent protein (GFP) under the control of these regulatory elements. A construct driven by the Kit promoter and including all 6 HS sites is highly expressed during mouse development in Kit+ cells including PGCs and hematopoietic progenitors (erythroid blast-forming units and mixed colony-forming units). In contrast, the Kit promoter alone (comprising HS1) is sufficient to drive low-level GFP expression in PGCs, but unable to function in hematopoietic cells. Hematopoietic expression further requires the addition of the intronproximal HS2 fragment; HS2 also greatly potentiates the activity in PGCs. Thus, HS2 acts as an enhancer integrating transcriptional signals common to 2 developmentally unrelated stem cell/progenitor lineages. Optimal hematopoietic expression further requires HS3-HS6.

Lipopolysaccharide or whole bacteria block the conversion of inflammatory monocytes into dendritic cells in vivo

Monocytes can develop into dendritic cells (DCs) that migrate to lymph nodes (LNs) and present antigens to T cells. However, we find that this differentiation is blocked when monocytes accumulate subcutaneously in response to bacteria or lipopolysaccharide (LPS). The inhibition of DC differentiation is mediated by the bacteria and in conjunction with inflammatory cells recruited at the site of injection. Inhibition of migratory DC development was reversed in Toll-like receptor (TLR)4-mutated mice when LPS, but not whole bacteria, was injected, suggesting that TLR4 is one but not the only mediator of the inhibition. The block imposed by bacteria was partly relieved by the absence of interleukin (IL)-12 p40, but not by individual absence of several cytokines involved in DC differentiation or in inflammation, i.e., IL-6, IL-10, IL-12 p35, and interferon γ. Consistent with the inability of monocytes to yield migrating DCs, and the finding that other DCs had limited access to particulate or bacterial antigens, these antigens were weakly presented to T cells in the draining LN. These results illustrate that bacteria-associated signals can have a negative regulatory role on adaptive immunity and that local innate responses for containment of infectious bacteria can at least initially supersede development of adaptive responses.

PML-RAR induces promyelocytic leukemias with high efficiency following retroviral gene transfer into purified murine hematopoietic progenitors

Acute promyelocytic leukemia (APL) is associated with chromosomal translocations resulting in fusion proteins of the retinoic acid receptor (RAR). Here, we report a novel murine model system for APL, based on the transduction of purified murine hematopoietic progenitors (lin(-)) using high-titer retroviral vectors encoding promyelocytic leukemia-RAR (PML-RAR), and the green fluorescent protein (GFP) as a marker. PML-RAR-expressing lin(-) cells were impaired in their ability to undergo terminal myeloid differentiation and showed increased proliferative potential in vitro. Inoculation of transduced lin(-) cells into syngeneic, irradiated mice resulted in the development of retinoic acid-sensitive promyelocytic leukemias at high frequency (> 80%) and short latency (approximately 4 months). Morphologic and immunophenotypic analysis revealed no gross abnormalities of the preleukemic bone marrows. However, hematopoietic progenitors from PML-RAR preleukemic mice showed a severe impairment in their ability to undergo myeloid differentiation in vitro. This result, together with the monoclonality or oligoclonality of the leukemic blasts, supports a "multiple-hit" model, where the fusion protein causes a "preleukemic" phase, and leukemia occurs after additional genetic lesions. This model system faithfully reproduces the main characteristics of human APL and represents a versatile tool for the in vitro and in vivo study of mechanisms of leukemogenesis and the design of protocols for differentiation treatment.

In vitro and in vivo hematopoietic potential of human stem cells residing in muscle tissue

OBJECTIVE

We studied the in vitro and in vivo hematopoietic potential of human stem cells residing in muscle tissue collected from adults with head and neck cancer.

MATERIALS AND METHODS

Adherent muscle cells were cultured in F12 medium with 10% fetal bovine serum and transplanted into immunodeficient mice.

RESULTS

On day 12 we obtained a median of 500,000 adherent cells per gram muscle sample. Thy-1, endoglin, HER2/neu, and P1H12 were expressed in the majority of cells. CD34, VEGFR2, c-kit, VCAM-1, and CXCR4 were expressed in 0.5-1.5%, 1-5%, 1-15%, 9-15%, and 30% of cells, respectively. Immunodeficient mice transplanted with fresh muscle cells or less than 500,000 cultured cells showed little or no human engraftment. In mice transplanted with more than 500,000 cultured cells, up to 14% human CD45(+) hematopoietic cells (including myeloid and lymphoid subsets) were detected by flow cytometry. Engraftment was confirmed by polymerase chain reaction, Southern blotting, and DNA sequencing. Liver, muscle, and spleen evaluated for human DNA were positive in the majority of mice showing hematopoietic engraftment in the bone marrow. In vivo hematopoietic engraftment potential was maintained in cultured CD45(-) muscle cells transduced with the green fluorescence protein gene.

CONCLUSIONS

Human stem cells residing in muscle tissue can generate multilineage hematopoiesis in immunodeficient mice. Surprisingly, this hematopoietic potential increased in cultured versus fresh cells from muscle tissue.

Placental transport of leucine, phenylalanine, glycine, and proline in intrauterine growth-restricted pregnancies

L-[1-13C]Leucine, [1-13C]glycine, L-[1-13C]phenylalanine, and L-[1-13C]proline were infused as a bolus into the maternal circulation of seven appropriate for gestational age at 30.3 +/- 3.0 wk and 7 intrauterine growth-restricted pregnancies at 26.5 +/- 1.0 wk gestation to investigate placental transport in vivo. Umbilical venous samples were obtained at the time of in utero fetal blood sampling at 450 +/- 74 sec from the bolus injection. In normal pregnancies the fetal/maternal (F/M) enrichment ratios for leucine (0.76 +/- 0.06) and phenylalanine (0.77 +/- 0.06) were higher (P < 0.01) than the F/M ratios for glycine (0.18 +/- 0.04) and proline (0.22 +/- 0.02). This suggests that these two essential amino acids rapidly cross the placenta in vivo. Compared with the essentials, both glycine and proline had significantly lower F/M enrichment ratios, which were not different from each other. The results support the hypothesis that amino acids with high affinity for exchange transporters cross the placenta most rapidly. In intrauterine growth-restricted pregnancies, the F/M enrichment ratio was significantly lower (P < 0.01) for L-[1-13C]leucine (0.76 +/- 0.06 vs. 0.48 +/- 0.07) and for L-[1-13C]phenylalanine (0.77 +/- 0.06 vs. 0.46 +/- 0.07) compared with appropriate for gestational age pregnancies reflecting impaired transplacental flux. The F/M enrichment ratio did not differ for [1-13C]glycine (0.18 +/- 0.04 vs. 0.17 +/- 0.03), and L-[1-13C]proline (0.22 +/- 0.02 vs. 0.18 +/- 0.04).

A new synthetic approach to 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-benzimidazol-2-one(J-113397), the first non-peptide ORL-1 receptor antagonist

An efficient approach to 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-benzimidazol-2-one (J-113397) 1, the first non-peptide ORL-1 receptor antagonist described in literature, is outlined. After construction of the piperidine framework through Dieckmann cyclization of the Michael adduct 8 of cyclooctylmethylamine to methyl acrylate, condensation with o-phenylendiamine produced the beta-enamino ester 2, which has been conveniently used to construct the benzimidazolone substituent at C-4. Catalytic hydrogenation of intermediate 11 followed by base-promoted cis--trans isomerization of the key compound 12 led to the formation of ester 13, which was converted to the racemic title compound by LiAlH(4) reduction. The pure enantiomers were obtained by chiral preparative HPLC separation using a derivatized cellulose-based stationary phase.

Selective δ opioid receptor agonists for inflammatory and neuropathic pain

In the last decade a number of selective and potent non-peptidic agents became available to explore the usefulness of the delta-opioid receptor in modulation of pain of different origins. As a continuing effort in this field, potent and selective delta-opioid agonists based on the pyrrolomorphinan framework have been designed, synthesised and characterised biologically in our laboratories. In animal models, a selected compound of interest, SB 235863, has proved the concept that selective delta-opioid agonists may have great potential as pain relief agents in inflammatory and neuropathic pain conditions. Importantly, such a compound was free of the unwanted side effects usually associated with narcotic analgesics such as morphine.

Ecteinascidin-743 (ET-743), a natural marine compound, with a unique mechanism of action

The mode of action of Ecteinascidin-743 (ET-743), a marine tetrahydroisoquinoline alkaloid isolated from Ecteinascidia turbinata, which has shown very potent antitumour activity in preclinical systems and encouraging results in Phase I clinical trials was investigated at a cellular level. Both SW620 and LoVo human intestinal carcinoma cell lines exposed for 1 h to ET-743 progress through S phase more slowly than control cells and then accumulate in the G2M phase. The sensitivity to ET-743 of G1 synchronised cells was much higher than that of cells synchronised in S phase and even higher than that of cells synchronised in G2M. ET-743 concentrations up to four times higher than the IC(50) value caused no detectable DNA breaks or DNA-protein cross-links as assessed by alkaline elution techniques. ET-743 induced a significant increase in p53 levels in cell lines expressing wild-type (wt) (p53). However, the p53 status does not appear to be related to the ET-743 cytotoxic activity as demonstrated by comparing the drug sensitivity in p53 (-/-) or (+/+) mouse embryo fibroblasts and in A2780 ovarian cancer cells or the A2780/CX3 sub-line transfected with a dominant-negative mutant TP53. The cytotoxic potency of ET-743 was comparatively evaluated in CHO cell lines proficient or deficient in nucleotide excision repair (NER), and it was found that ET-743 was approximately 7-8 times less active in ERCC3/XPB and ERCC1-deficient cells than control cells. The findings that G1 phase cells are hypersensitive and that NER-deficient cells are resistant to ET-743 indicate that the mode of action of ET-743 is unique and different from that of other DNA-interacting drugs.

Pharmacological profiles of selective non-peptidic delta opioid receptor ligands

Several non-peptidic opioids have been synthesized recently as part of a program to develop selective delta receptor agonists. In this study, the affinities of a set of compounds for cloned delta and mu opioid receptors expressed in HEK 293 cell lines were determined by competition analysis of [3H]bremazocine binding to membrane preparations. All compounds studied exhibited high affinity and selectivity, with apparent dissociation constants in the range of 0.6-1.7 nM for the delta opioid receptor and 240-1165 nM for the mu opioid receptor. We next sought to determine which domain of the delta receptor was critical for mediating the highly selective binding by analysis of ligand affinities for mu/delta receptor chimeras. Receptor binding profiles suggested that a critical site of receptor/ligand interaction was located between transmembrane domain 5 (TM5) and TM7 of the delta receptor. Substitution of tryptophan 284, located at the extracellular surface of TM6, with lysine, which is found at the equivalent position in the mu opioid receptor, led to a spectrum of effects on affinities, depending on the ligand tested. Affinities of SB 219825 and SB 222941 were particularly sensitive to the substitution, displaying a 50-fold and 70-fold decrease in affinity, respectively. Activities of the delta receptor-selective agonists were tested in two functional assays. Brief exposure of HEK 293 cells expressing delta opioid receptors with selective ligands induced phosphorylation of MAP kinase, although the non-peptidic ligands were less efficacious than the enkephalin derivative DADL (Tyr-D-Ala-Gly-Phe-D-Leu). Similarly, chronic exposure of HEK 293 cells expressing delta opioid receptors with selective, non-peptidic ligands, with the exception of SB 206848, caused receptor down-regulation, however, the SB compounds were less efficacious than DADL.

Isolation and characterization of an IGROV-1 human ovarian cancer cell line made resistant to Ecteinascidin-743 (ET-743)

By exposing Igrov-1 human ovarian cancer cells to increasing concentrations of Ecteinascidin-743 (ET-743), either for a short or prolonged time, we obtained sublines resistant to ET-743 which overexpress Pgp. The most resistant clone (Igrov-1/25 ET) was evaluated for biological and pharmacological characterizations. The increased Pgp levels of Igrov-1/25 ET were not due to amplification of the mdr-1 gene but to increased mRNA levels. No increase in other multidrug resistance-related proteins such as MRP or LRP was observed in Igrov-1/25 ET. The IC50 values of ET-743 against Igrov-1/25 ET was approximately 50 times higher than the parental cell line. Resistance was not reversed while maintaining the cell line in drug-free medium for at least 24 months. Igrov-1/25 ET was cross-resistant to Doxorubicin and VP16 while it was equally sensitive to L-PAM, MNNG, CPT and only marginally less sensitive to Cis-DDP and Oxaliplatin compared to the parental cell line. Igrov-1/25 ET exposed to Doxorubicin retained this drug much less, mainly because of a more efficient drug efflux. The cyclosporine analogue SDZ PSC-833 reversed the resistance of Igrov-1/25 ET to ET-743, without any enhancement of the drug activity against the parental Igrov-1 cell line. Igrov-1/25 ET exhibits typical features of cell lines overexpressing the mdr-1 gene and can be a potentially useful tool in selecting ET-743 non-cross-resistant analogues as well as to investigate methods to counteract resistance to this drug.

The impact of malnutrition on the quality of life in the elderly

Malnutrition is a frequent condition, both widely represented in geriatric population and underestimated in diagnostic and therapeutic work-up, and is known to affect health status and life expectancy of elderly people. The unexpected weight loss is a pathological condition, recently classified in three different ways (sarcopenia, wasting and cachexia) according to criteria of nutritional intake, functional abilities and age-related body composition modifications, that is caused by social psychological and medical factors. In this review, the authors highlight the ways that, through malnutrition, could lead to an impairment of quality of life in elderly people. Notwithstanding the great impreciseness and confusion that surrounds the term 'quality of life', the authors focus their attention on the correlation existing with the recently occurring changes to patients' health status and life-style, analysing the relationship with frailty, failure to thrive and homeostatic balance failure syndrome. With the latter term, the authors introduce a pathological condition widely represented in the late stages of malnutrition that often evolves in multiple organ failure and lastly in the death.

Synthesis and NMR characterization of a novel class of thienomorphinans

[formula: see text] Synthesis of four novel thieno derivatives 4-7 featuring the codeine skeletal backbone is reported. Characterization by 1H and 13C NMR is also discussed, along with binding profile for opioid receptors.

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.

Mode of action of thiocoraline, a natural marine compound with anti-tumour activity

Thiocoraline, a new anticancer agent derived from the marine actinomycete Micromonospora marina, was found to induce profound perturbations of the cell cycle. On both LoVo and SW620 human colon cancer cell lines, thiocoraline caused an arrest in G1 phase of the cell cycle and a decrease in the rate of S phase progression towards G2/M phases, as assessed by using bromodeoxyuridine/DNA biparametric flow cytometric analysis. Thiocoraline does not inhibit DNA-topoisomerase II enzymes in vitro, nor does it induce DNA breakage in cells exposed to effective drug concentrations. The cell cycle effects observed after exposure to thiocoraline appear related to the inhibition of DNA replication. By using a primer extension assay it was found that thiocoraline inhibited DNA elongation by DNA polymerase alpha at concentrations that inhibited cell cycle progression and clonogenicity. These studies indicate that the new anticancer drug thiocoraline probably acts by inhibiting DNA polymerase alpha activity.

Cell cycle perturbations and apoptosis induced by isohomohalichondrin B (IHB), a natural marine compound

Isohomohalichondrin B (IHB), a novel marine compound with anti-tumoral activity, extracted from the Lissodendorix sponge, inhibits GTP binding to tubulin, preventing microtubule assembly. Cell cycle perturbations and apoptosis induced by IHB were investigated on selected human cancer cell lines by using flow cytometric and biochemical techniques. Monoparameter flow cytometric analysis showed that 1 h IHB exposure caused a delayed progression through S-phase, a dramatic block in G2M phase of the cell cycle and the appearance of tetraploid cell population in LoVo, LoVo/DX, MOLT-4 and K562 cells. At 24 h after IHB exposure, the majority of cells blocked in G2M were in prophase as assessed by morphological analysis and by the fact that they expressed high levels of cyclin A/cdc2 and cyclin B1/cdc2. At 48 h, all cells were tetraploid as assessed by biparameter cyclin A/DNA and cyclin B1/DNA content analysis. Apoptotic death was detected in both leukaemic MOLT-4 and K562 cells, which express wild-type and mutated p53 respectively, when the cells were blocked in mitotic prophase. In conclusion, IHB is a novel potent anti-tumour drug that causes delayed S-phase progression, mitotic block, tetraploidy and apoptosis in cancer cell lines.

Heart rate and blood pressure variability in obese normotensive subjects

OBJECTIVE

To assess autonomic modulation of cardiovascular activity in massively obese subjects.

DESIGN

Cross-sectional clinical study.

SUBJECTS

43 age-matched normotensive subjects: 15 moderately obese (body mass index (BMI) < 40); 14 massively obese (BMI > 40) and 14 nonobese controls (BMI < 26).

MEASUREMENTS

Using power spectral analysis, heart rate and arterial pressure variability were determined at rest and after sympathetic stress (tilt). Two spectral components were analysed: a low-frequency (LF) component at around 0.1 Hz, predominantly reflecting sympathetic modulation and a high-frequency (HF) component at around 0.26 Hz, reflecting parasympathetic modulation.

RESULTS

Spectral data for heart rate showed that the massively obese subjects had lower LF [mean +/- s.e.m.] normalized units (NUs) at rest (35.1 +/- 0.9) and after tilt (56.1 +/- 2.1), than the moderately obese subjects (LF NUs at rest 53.9 +/- 4.2, P < 0.001; LF NUs tilt: 66.8 +/- 5.6, P < 0.001) and nonobese control subjects (LF NUs at rest, 56.6 +/- 3.0, P < 0.001); (LF NUs tilt: 81.7 +/- 1.7, P < 0.001). Data for systolic arterial pressure variability measured at rest exhibited the inverse pattern, the massively obese group having higher mean LF values (LF mm Hg2 rest: 15.0 +/- 1.4; LF mm Hg2 tilt: 15.7 +/- 1.5) than the moderately obese group (LF mm Hg2 rest 3.2 +/- 0.7, P < 0.001; LF mm Hg2 tilt: 7.2 +/- 2.0, P < 0.001) and than the nonobese control subjects (LF mm Hg2 rest 3.5 +/- 0.5, LF mm Hg2 tilt 8.5 +/- 0.8, P < 0.001). Regression detected a significant association between BMI and LF of systolic pressure (beta = 0.364; P = 0.0007), In LF of heart rate (beta = -5.555; P = 0.00001) and very low frequency (VLF) of diastolic pressure (beta = -3.305; P = 0.0020).

CONCLUSION

Obesity seems to increase sympathetic modulation of arterial pressure, but diminishes modulation of heart rate. Because our obese subjects had high plasma noradrenaline levels, their low LF power of heart rate could reflect diminished adrenoceptor responsiveness.

Hyperinsulinaemia, regional adipose tissue distribution and left ventricular mass in normotensive, elderly, obese subjects

Obesity is a metabolic condition, related to abnormalities of the glyco-insulinaemic metabolism, and plays a substantial role in the development of cardiovascular disease. The aim of this study was to establish a correlation among left ventricular mass, evaluated echocardiographically according to Penn Convention criteria, blood pressure, evaluated by ambulatory blood pressure monitoring, anthropometric indices for evaluation of body mass index and waist to hip ratio circumference, regional adipose tissue distribution, evaluated by ultrasound measurements of visceral adipose tissue, and insulin resistance, evaluated by hyperinsulinaemia by oral glucose tolerance test. We selected two groups of elderly male subjects well matched for age (68.5 +/- 6.4 years): 29 obese and 20 lean, with a body mass index, respectively, of 34.6 +/- 2.9 and 23.4 +/- 2.3. Statistical analysis was carried out by Student's t-test and linear regression analysis. In spite of the fact that statistical analysis showed a higher, though not statistically significant, systolic and diastolic mean blood pressure in the lean subjects, we found an increased left ventricular mass in obese subjects (P < 0.0001). The area under the insulin curve was higher in obese than in lean subjects (P < 0.0001) while the area under the glucose curve was not significantly different in the two groups. Furthermore, linear regression analysis showed that in obese subjects left ventricular mass was strictly correlated with visceral adipose tissue (r = 0.607; P < 0.0001) and hyperinsulinaemia (r = 0.615; P < 0.0001). In conclusion, our data suggest that centripetal adipose tissue distribution and hyperinsulinaemia, independent of blood pressure values, are closely correlated with left ventricular mass.

Characterization of cyclin B1 expression in human cancer cell lines by a new three-parameter BrdUrd/cyclin B1/DNA analysis

Flow cytometric cyclin expression/DNA content analysis, now commonly used, provides useful information on the mechanisms regulating cell cycle progression. However, this biparametric analysis does not make a clear-cut distinction between G1 and S-early or between S-late and G2M phase cells. This paper proposes a new three-parameter flow cytometric method with which to determine cyclin B1 levels in single cells in different cell cycle phases by coupling bromodeoxyuridine (BrdUrd) immunodetection and DNA content. DNA denaturation by HCl did not alter the level of cyclin B1. Differences in cyclin B1 expression were observed in seven human cancer cell lines of different origin. The percentage of cyclin B1-positive cells and the cyclin B1 content per cell indicated different patterns. In some cases cyclin B1 accumulation preceded the G2M checkpoint, at which its content usually started to rise. Using available easily reproducible techniques, this flow cytometric approach gives details of intracellular variability in cyclin expression.

Association between the activity of the system A amino acid transporter in the microvillous plasma membrane of the human placenta and severity of fetal compromise in intrauterine growth restriction

Primarily, our objectives were to compare system A amino acid transporter activity in the microvillous plasma membrane (MVM) of placentas from normally grown (appropriate for gestational age, AGA) and intrauterine growth-restricted (IUGR) fetuses delivered during the third trimester, as a whole and in relation to the severity of IUGR. Ten AGA and 16 IUGR pregnancies were studied at the time of elective cesarean section performed between 28 and 40 wk of gestation. Severity of IUGR pregnancies was assessed primarily by Doppler velocimetry and fetal heart rate monitoring. Placental MVM vesicles were prepared, and system A activity in these was measured. The transporter activity was significantly lower in IUGR compared with AGA pregnancies. Within the IUGR group system A activity was only significantly lower, compared with AGA, in cases that presented with a reduction in umbilical blood flow. We conclude that placental MVM system A activity is lower in IUGR compared with AGA pregnancies delivered during the third trimester. System A activity is related to the severity of IUGR.

Discovery of a novel class of substituted pyrrolooctahydroisoquinolines as potent and selective delta opioid agonists, based on an extension of the message-address concept

This paper describes the design and synthesis of compounds belonging to a novel class of substituted pyrrolooctahydroisoquinolines which are potent and selective delta opioid agonists. Molecular modeling studies performed on known, selective delta ligands such as (+)-3 and the potent delta agonists SNC 80 led to the identification of the carboxamido moiety of the latter as a putative nonaromatic delta address. Insertion of this moiety onto the octahydroisoquinoline opioid message resulted in (+/-)-5b, a potent and selective delta ligand. The active enantiomer, (-)-5b, displayed nanomolar affinity for the delta receptor (Ki = 0.9 nM) with good mu/delta and kappa/delta binding selectivity ratios (140 and 1480, respectively). In addition, (-)-5b behaved as a full delta agonist in the mouse vas deferens bioassay having an IC50 = 25 nM and being antagonised in the presence of 30 nM naltrindole (NTI). These studies, based on the message-address concept, indicated that the nonaromatic (N,N-diethylamino)carbonyl moiety is a viable alternative to the classical benzene ring as a delta opioid address. Preliminary in vivo studies showed that (+/-)-5b produced a dose-related antinociception in the mouse abdominal constriction test after intracerebroventricular administration (ED50 = 1.6 micrograms/mouse).

Power spectral analysis of heart rate variability in obese subjects: evidence of decreased cardiac sympathetic responsiveness

OBJECTIVE

To investigate changes in sympathetic nervous system function in obesity.

DESIGN

Cross-sectional clinical study.

SUBJECTS

18 middle-aged obese patients (43-55 years, BMI > 33 kg/m2) and 26 age- and sex-matched normal-weight controls (44-56 years, BMI < 26 kg/m2).

MEASUREMENTS

Post-synaptic sympathetic response studied by power spectral analysis of heart rate variability at rest and during sympathetic stimulus obtained through passive head-up tilt. Spectral analysis comprised two frequency domain components: high-frequency power (HF), reflecting parasympathetic activity and low-frequency power (LF), in particular the LF: HF ratio, reflecting sympathetic function. Pre-synaptic sympatho-adrenal function was assessed by measurement of 8.00 am plasma noradrenaline.

RESULTS

Obese patients had significantly lower spectral indexes of sympathetic response and higher spectral markers of parasympathetic activity than nonobese subjects both at rest (25.9 +/- 3.5 vs 38.6 +/- 1.7 LF NUs, P < 0.001) and after tilt (0.98 +/- 0.40 vs 2.30 +/- 0.39 LF: HF, P < 0.05; 62.7 +/- 6.9 vs 41.1 +/- 4.9 HF NUs, P < 0.05). By contrast, the obese subjects had higher noradrenaline levels (289.32 +/- 27.40 vs 159.80 +/- 19.20 pg/ml, P < 0.001). No relation was found between these neuroautonomic indexes and body mass index.

CONCLUSION

Obese subjects seem to have increased pre-synaptic sympatho-adrenal function but a depressed end-organ cardiovascular response.

Maternal concentrations and fetal-maternal concentration differences of plasma amino acids in normal and intrauterine growth-restricted pregnancies

OBJECTIVES

Our purpose was to determine whether maternal amino acid concentration changes during gestation in pregnancies with intrauterine growth restriction as in normal pregnancies and to verify whether these changes are related to changes in fetal-maternal differences.

STUDY DESIGN

Amino acid concentrations were measured in 5 nonpregnant women, in 11 second-trimester and 10 third-trimester pregnant women with appropriate-for-gestational-age fetuses, and in 23 pregnant women with intrauterine growth restriction. Umbilical venous amino acids were measured at the time of fetal blood sampling. The severity of intrauterine growth restriction was assessed by Doppler velocimetry and fetal heart rate and by evaluation of oxygenation and acid-base balance.

RESULTS

In normal pregnant women the maternal concentration of most amino acids was significantly lower in both the second and third trimesters compared with nonpregnant women. In intrauterine growth restriction the maternal concentrations of most essential amino acids were significantly higher than in appropriate-for-gestational-age pregnancies. This observation, coupled with lower fetal amino acid concentrations in intrauterine growth restriction, leads to significantly lower fetal-maternal differences.

CONCLUSIONS

Normal pregnant women have a significant decrease in amino acid concentrations compared with nonpregnant women, whereas in intrauterine growth restriction maternal amino acids are reduced less, Significantly lower fetal-maternal concentration differences are present in intrauterine growth restriction, independent of the degree of severity.