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Biomedical subjects

Joseph Levy

Publications and source records attributed to Joseph Levy.

At least 19 recordsLinked to original sources
PubMed2006

Lycopene and other carotenoids inhibit estrogenic activity of 17beta-estradiol and genistein in cancer cells.

Epidemiological evidence suggests that carotenoids prevent several types of cancer, including mammary and endometrial cancers. On the other hand, such studies have also shown that estrogens are the most important risk factors for these cancer types. Genistein, the phytoestrogen mainly found in soy, also shows significant estrogenic activity when tested at concentrations found in human blood. The aim of this study was to determine whether carotenoids inhibit signaling of steroidal estrogen and phytoestrogen which could explain their cancer preventive activity. Similar to the known effect of 17beta-estradiol (E(2)), treatment of breast (T47D and MCF-7) and endometrial (ECC-1) cancer cells with phytoestrogens induced cell proliferation, cell-cycle progression and transactivation of the estrogen response element (ERE). However, each of the tested carotenoids (lycopene, phytoene, phytofluene, and beta-carotene) inhibited cancer cell proliferation induced by either E(2) or genistein. The inhibition of cell growth by lycopene was accompanied by slow down of cell-cycle progression from G1 to S phase. Moreover, the carotenoids inhibited estrogen-induced transactivation of ERE that was mediated by both estrogen receptors (ERs) ERalpha and ERbeta. The possibility that this inhibition results from competition of carotenoid-activated transcription systems on a limited pool of shared coactivators with the ERE transcription system was tested. Although cotransfection of breast and endometrial cancer cells with four different coactivators (SRC-1, SRC-2, SRC-3, and DRIP) strongly stimulated ERE reporter gene activity, it did not oppose the inhibitory effect of carotenoids. These results suggest that dietary carotenoids inhibit estrogen signaling of both 17beta-estradiol and genistein, and attenuate their deleterious effect in hormone-dependent malignancies.

Breast Neoplasms↗
PubMed2006

Isolation of Dialister pneumosintes isolated from a bacteremia of vaginal origin.

In this report, we review one case of bacteremia infection due to Dialister pneumosintes. The patient was admitted in post-partum with vaginosis and suppurative thrombosis of the ovarian veina. D. pneumosintes was isolated in pure culture from the three blood culture flasks. Identification of this bacterium was difficult and requires the amplification and partial sequencing of the 16S rRNA gene. The patients had favorable outcome after antibiotic treatment.

Adult↗
PubMed2006

Cooperative antitumor effects of vitamin D3 derivatives and rosemary preparations in a mouse model of myeloid leukemia.

1alpha,25-dihydroxyvitamin D(3) (1,25D(3)) is a powerful differentiation agent, which has potential for treatment of myeloid leukemias and other types of cancer, but the calcemia produced by pharmacologically active doses precludes the use of this agent in the clinic. We have shown that carnosic acid, the major rosemary polyphenol, enhances the differentiating and antiproliferative effects of low concentrations of 1,25D(3) in human myeloid leukemia cell lines (HL60, U937). Here we translated these findings to in vivo conditions using a syngeneic mouse leukemia tumor model. To this end, we first demonstrated that as in HL60 cells, differentiation of WEHI-3B D(-) murine myelomonocytic leukemia cells induced by 1 nM 1,25D(3) or its low-calcemic analog, 1,25-dihydroxy-16-ene-5,6-trans-cholecalciferol (Ro25-4020), can be synergistically potentiated by carnosic acid (10 microM) or the carnosic acid-rich ethanolic extract of rosemary leaves. This effect was accompanied by cell cycle arrest in G0 + G1 phase and a marked inhibition of cell growth. In the in vivo studies, i.p. injections of 2 microg Ro25-4020 in Balb/c mice bearing WEHI-3B D(-) tumors produced a significant delay in tumor appearance and reduction in tumor size, without significant toxicity. Another analog, 1,25-dihydroxy-16,23Z-diene-20-epi-26,27-hexafluoro-19-nor-cholecalciferol (Ro26-3884) administered at the same dose was less effective than Ro25-4020 and profoundly toxic. Importantly, combined treatment with 1% dry rosemary extract (mixed with food) and 1 microg Ro25-4020 resulted in a strong cooperative antitumor effect, without inducing hypercalcemia. These results indicate for the first time that a plant polyphenolic preparation and a vitamin D derivative can cooperate not only in inducing leukemia cell differentiation in vitro, but also in the antileukemic activity in vivo. These data may suggest novel protocols for chemoprevention or differentiation therapy of myeloid leukemia.

Abietanes↗
PubMed2006

Lycopene inhibition of IGF-induced cancer cell growth depends on the level of cyclin D1.

BACKGROUND: Insulin-like growth factors (IGFs) play an important role in normal and cancerous cell proliferation. Moreover, in recent studies IGF-I has been implicated as a major cancer risk factor. The tomato carotenoid lycopene and all-trans retinoic acid (atRA) have been shown to inhibit growth factor-induced proliferation of different types of cancer cells. This action is associated with inhibition of cell cycle progression in G0/G1 phase. Cyclin D1 acts as a growth factor sensor in G1 phase and is overexpressed in many breast cancer tumors. We have previously demonstrated that slowdown of serum-stimulated cell cycle progression from G1 to S phase by lycopene correlates with reduction in cyclin D1 levels, suggesting that the expression of this protein is a main target for lycopene's action. AIM OF THE STUDY: To determine whether the reported reduction in cyclin D1 level is the key mechanism for lycopene and atRA inhibitory action on IGF-I-induced cell cycle progression. RESULTS: Human breast (MCF-7) and endometrial (ECC-1) cancer cells were synchronized in G0/G1 phase by serum deprivation followed by stimulation with IGF-I. Cell treatment with lycopene and atRA inhibited IGF-I-stimulated cell cycle progression from G1 to S phase and decreased retinoblastoma protein (pRb) phosphorylation. These events were associated with a reduction in cyclin D1 and p21(CIP1/WAF1) level, but not that of p27(KIP1). To test the hypothesis that the decrease in cyclin D1 has a major role in the inhibitory effects of lycopene and atRA, we examined the ability of these two agents to suppress cell cycle progression in MCF-7.7D1.13 cells which are capable of expressing cyclin D1 under the control of the Zn-inducible metallothionein promoter. Our results showed that ectopic expression of cyclin D1 can overcome cell cycle inhibition caused by lycopene and atRA. CONCLUSIONS: Our findings suggest that attenuation of cyclin Dl levels by lycopene and atRA is an important mechanism for the reduction of the mitogenic action of IGF-I.

Antineoplastic Agents↗
PubMed2005

A randomized, double-blind trial of Lactobacillus GG versus placebo in addition to standard maintenance therapy for children with Crohn's disease.

Probiotics are widely used by patients with Crohn's disease (CD) in an attempt to improve their health, but few controlled studies have been done to evaluate the efficacy of these therapies. We conducted a randomized, placebo-controlled trial of the probiotic Lactobacillus rhamnosus strain GG (LGG) to see if the addition of LGG to standard therapy prolonged remission in children with CD. Concomitant medications allowed in the study included aminosalicylates, 6-mercaptopurine, azathioprine, and low-dose alternate day corticosteroids. Seventy-five children (age range, 5-21 yr) with CD in remission were randomized to either LGG (n=39) or placebo (n=36) and followed for up to 2 years. The median time to relapse was 9.8 months in the LGG group and 11.0 months in the placebo group (P=0.24); 31% (12/39) of patients in the LGG group developed a relapse compared with 6/36 (17%) of the placebo group (P=0.18). The LGG was well tolerated, with a side effect profile comparable with placebo. This study suggests that LGG does not prolong time to relapse in children with CD when given as an adjunct to standard therapy.

Adolescent↗
PubMed2005

Presentation of pediatric celiac disease in the United States: prominent effect of breastfeeding.

Childhood celiac disease (CD) is considered rare in the United States. Consequently there are few data concerning its clinical presentation. A validated questionnaire was distributed to families of children with CD. One hundred forty-one children with biopsy-proven CD were included in the study. We found significant differences in the clinical spectrum of children based on their infant feeding history. Exclusively breastfed children were significantly less likely to report failure to thrive (69% vs 88%, p<0.05) and short stature (37% vs 62%, p<0.05), and had a higher rate of "atypical'' symptoms (p<0.01). Breastfeeding alters the presentation and contributes to atypical presentations of CD and diagnostic delay. Pediatricians need to be aware of the diverse manifestations of celiac disease to reduce diagnostic delay.

Age Distribution↗
PubMed2005

Carotenoids activate the antioxidant response element transcription system.

Epidemiologic studies have found an inverse association between consumption of tomato products and the risk of certain types of cancers. However, the mechanisms underlying this relationship are not completely understood. One mechanism that has been suggested is induction of phase II detoxification enzymes. Expression of phase II enzymes is regulated by the antioxidant response element (ARE) and the transcription factor Nrf2 (nuclear factor E2-related factor 2). In this study, we determined the role of this transcription system in the induction of phase II enzymes by carotenoids. We found that in transiently transfected cancer cells, lycopene transactivated the expression of reporter genes fused with ARE sequences. Other carotenoids such as phytoene, phytofluene, beta-carotene, and astaxanthin had a much smaller effect. An increase in protein as well as mRNA levels of the phase II enzymes NAD(P)H:quinone oxidoreductase and gamma-glutamylcysteine synthetase was observed in nontransfected cells after carotenoid treatment. Ethanolic extract of lycopene containing unidentified hydrophilic derivatives of the carotenoid activated ARE with similar potency to lycopene. The potency of the carotenoids in ARE activation did not correlate with their effect on intracellular reactive oxygen species and reduced glutathione level, which may indicate that ARE activation is not solely related to their antioxidant activity. Nrf2, which is found predominantly in the cytoplasm of control cells, translocated to the nucleus after carotenoid treatment. Interestingly, part of the translocated Nrf2 colocalized with the promyelocytic leukemia protein in the promyelocytic leukemia nuclear bodies. The increase in phase II enzymes was abolished by a dominant-negative Nrf2, suggesting that carotenoid induction of these proteins depends on a functional Nrf2 and the ARE transcription system.

Antioxidants↗
PubMed2004

Carotenoids and transcription.

The possible involvement of several transcription systems in the anticancer activity of carotenoids is the focus of this review. Carotenoids modulate the basic mechanisms of cell proliferation, growth factor signaling, gap junctional intercellular communication, and produce changes in the expression of many proteins participating in these processes. The changes in the expression of multiple proteins suggest that the initial effect of carotenoids involves modulation of transcription. We and others have found evidence for the role of several transcription systems, such as the retinoid receptors, activator protein-1 (AP-1), peroxisome proliferator-activated receptors (PPAR), xenobiotic receptors and the antioxidant response element (ARE), in the anticancer activity of carotenoids. The observed modulation of a network of transcription systems may provide the molecular basis for the synergistic anticancer effects of the combinations of various carotenoids together with other dietary and pharmacologic compounds.

Animals↗
PubMed2004

A pilot study of tacrolimus and mycophenolate mofetil graft-versus-host disease prophylaxis in childhood and adolescent allogeneic stem cell transplant recipients.

Tacrolimus (FK506)/mycophenolate mofetil (MMF) has been demonstrated to be an effective salvage therapy for steroid-resistant chronic graft-versus-host disease (GVHD), but its effectiveness as prophylaxis for acute GVHD (aGVHD) is unknown. We investigated the safety and efficacy of FK506/MMF in preventing aGVHD and sparing the use of methotrexate and methylprednisolone in childhood and adolescent allogeneic stem cell transplant (AlloSCT) recipients. Thirty-four childhood and adolescent patients (median age, 7 years; range, 0.5-21 years; 24 males and 10 females) undergoing 37 AlloSCTs for malignant (n = 22) and nonmalignant (n = 12) disorders received FK506 (0.03 mg/kg/d by continuous intravenous infusion) and MMF (15 mg/kg per dose orally or intravenously twice daily). Stem cell sources included 22 umbilical cord blood donors (21 unrelated and 1 related), 6 related bone marrow donors, and 9 related peripheral blood donors. Malignant diagnoses included 7 acute lymphoblastic leukemias, 3 acute myeloid leukemias, 1 acute promyelocytic leukemia, 2 non-Hodgkin lymphomas, 4 Hodgkin diseases, 3 chronic myeloid leukemias, and 2 neuroblastomas; nonmalignant diagnoses included 2 beta-thalassemias, 1 sickle cell disease, 4 aplastic anemias, 1 Wiskott-Aldrich syndrome, 1 Hurler syndrome, 2 hemophagocytic lymphohistiocytoses, and 1 myelodysplastic syndrome. The probability of developing grade > or =II aGVHD was 45.4% +/- 9.7% (7 related bone marrow/related peripheral blood; 5 umbilical cord blood), and for chronic GVHD it was 38.1% +/- 19.7%. FK506/MMF was well tolerated. Three patients had grade III to IV neurotoxicity (disorientation and leukoencephalopathy); 4 patients developed grade III to IV nephrotoxicity (all received concomitant nephrotoxins). Patients who achieved target mycophenolic acid levels (1.0-3.5 microg/mL) before day +30 had a significantly reduced incidence of developing grade >/=II aGVHD (16.7% +/- 15.2% versus 100%; P <.02). These results suggest that FK506/MMF is well tolerated and may be a safe and effective methotrexate- and methylprednisolone-sparing alternative GVHD prophylaxis regimen after AlloSCT. Further pharmacokinetic and pharmacodynamic studies are ongoing in pediatric and adolescent AlloSCT recipients to define optimal MMF dosing.

Adolescent↗
PubMed2004

The effect of global brain ischemia in normal and diabetic animals: the influence of calcium channel blockers.

Diabetes with hypertension is characterized by increased cerebrovascular pathology and poorer outcomes following stroke. In this study we evaluated the effect of global brain ischemia on brain metabolic parameters in normal and diabetic rats treated with a dihydropyridine calcium antagonist, felodipine. Normal and diabetic rats were treated daily with felodipine (5 mg/kg) or saline. After 4 wk global ischemia was produced by occluding the carotid arteries for 1 h. In other groups the occlusion was removed and the animals were allowed to reperfuse for an additional 2 h. Following 1 h global ischemia, with or without reperfusion, the animals and controls were killed by decapitation. Cerebral water, lactate, ATP, and glutamate were measured. Glo-bal ischemia with or without reperfusion increased cerebral water and lactate, but decreased ATP. Treatment with felodipine decreased lactate, but increased water content. Ischemia in diabetics with or without reperfusion decreased water and lactate. Treated diabetics had higher ATP levels after reperfusion. Glutamate levels were increased in diabetics and were further increased by treatment. We conclude that the enhanced CNS damage following cerebral ischemia in diabetes is not correlated with ATP or lactate levels and may be mediated in part by increased glutamate. Calcium channel antagonist may augment this process.

Adenosine Triphosphate↗
PubMed2003

Carnosic acid potentiates the antioxidant and prodifferentiation effects of 1alpha,25-dihydroxyvitamin D3 in leukemia cells but does not promote elevation of basal levels of intracellular calcium.

Differentiation therapy of cancer remains an only partially attained goal. Agents currently under active investigation include derivatives of vitamin D, modeled on its physiological hormone form, 1alpha,25-dihydroxyvitamin D(3) (1,25D(3)), but the calcemic effects of these compounds preclude their use in the clinic. An approach that may obviate this problem is to combine 1,25D(3) or its derivatives with other agents that increase the antineoplastic effects of low, nontoxic concentrations of vitamin D compounds. We have recently used the plant-derived polyphenolic antioxidant, carnosic acid (CA), to demonstrate an increase in the differentiating action of 1,25D(3) on human leukemia cells under these conditions (M. Danilenko et al., JNCI, 93: 1224-1233, 2001). We now show that treatment of HL60-G cells with either CA or 1,25D(3) alone resulted in a decrease in the intracellular levels of reactive oxygen species. Furthermore, the combination of 10 micro M CA and a low concentration of 1,25D(3) (1 nM) produced an enhanced antioxidant effect, which correlated with the potentiation of monocytic differentiation. Other plant antioxidants tested (curcumin, silibinin, and the organoselenium antioxidant ebselen) also potentiated differentiation induced by 1,25D(3), although alone, they had only minor differentiating effects. Differentiation induced by CA/1,25D(3) combinations was associated with increased intracellular glutathione content, whereas buthionine sulfoxime decreased both differentiation and the cellular glutathione content. This combination also enhanced the activation of the Raf-mitogen-activated protein/extracellular signal-regulated kinase kinase-extracellular signal-regulated kinase mitogen-activated protein kinase module and increased the binding of the activator protein-1 (AP-1) transcription factor to its cognate DNA element in the promoter regions of vitamin D receptor gene, suggesting that the mechanism of potentiation is at least in part attributable to induction and activation of components of this mitogen-activated protein kinase pathway. Cell treatment with a high concentration of 1,25D(3) (100 nM) resulted in a substantial elevation of basal intracellular calcium concentration. In contrast, importantly for an eventual clinical application of these studies, the potentiating action of CA on differentiation induced by a low concentration of 1,25D(3) (1 nM) was not accompanied by an elevation of basal intracellular calcium concentration. These findings suggest that combinations of CA with derivatives of vitamin D should be evaluated for use in differentiation therapy of myeloid leukemias.

Abietanes↗
PubMed2003

Modulation of transcriptional activity by antioxidant carotenoids.

It is widely accepted that diet changes are a powerful means to prevent cancer. The possible involvement of transcriptional activity in the anticancer activity of carotenoids will be the focus of this review. Carotenoids function as potent antioxidants, and this is clearly a major mechanism of their action. In addition carotenoids action involves interference in several pathways related to cancer cell proliferation and includes changes in the expression of many proteins participating in these processes such as connexins, phase II enzymes, cyclins, cyclin-dependent kinases and their inhibitors. These changes in protein expression suggest that the initial effect involves modulation of transcription by ligand-activated nuclear receptors or by other transcription factors. It is feasible to suggest that carotenoids and their oxidized derivatives interact with a network of transcription systems that are activated by different ligands at low affinity and specificity and that this activation leads to the synergistic inhibition of cell growth.

Animals↗
PubMed2002

Use of electrogastrography in children.

Electrogastrography (EGG), the measurement of gastric pacemeaker activity by means of surface electrodes, provides a noninvasive technique to detect and quantify the characteristics of the gastric slow wave. With a predominant frequency of three cycles per minute, the activity of the specialized cells responsible for this pacing, the interstitial cells of Cajal, is crucial in providing the underlying electrophysiologic changes that enable coordinated smooth muscle contraction and synchronized peristalsis. Advances in electronics and software to define frequency distribution, stability of the signal, postprandial changes, and other parameters have contributed to more widespread interest in EGG and its application to the investigation of functional gastrointestinal disturbances. Definition of pediatric norms and postnatal changes in the EGG of premature infants has provided the foundation for further studies investigating correlative changes with such important functions as gastric emptying and motility. The EGG remains a promising diagnostic tool. Future studies will help define its usefulness in identifying abnormal functions of the interstitial cells of Cajal.

Child↗
PubMed2002

Protective nutrients.

Recognition that specific nutrients can be beneficial when consumed in amounts above the accepted daily requirements has provided a major impetus for the critical examination of dietary approaches with single or multiple nutrient supplements chosen to modulate the inflammatory response, enhance immune function, or improve the blood-gut barrier. Patients suffering the effects of hypercatabolism caused by surgery, cancer, or extensive burns are prime candidates for immunonutrition, as the intervention has come to be known, as are immunosuppressed patients with the human immunodeficiency virus or other overwhelming infections. This review focuses on key nutrients used in clinical trials for which a body of information on the mode of action and metabolic pathways is available. The topics covered include the amino acids, glutamine and arginine; omega-3 fatty acids, eicosapentaenoic acid and docosahexanoic acid; vitamin A; and zinc. Lastly, we address the area of pre- and probiotics and how "friendly" microorganisms are being incorporated into therapeutic regimens aimed at sustaining health. The use of immunonutrition requires judicious consideration of the potential undesirable effects of certain additives in clinical settings where enhanced immune responsiveness can translate into tissue damage and altered mucosal defenses.

Journal Article↗
PubMed2002

Tyrosinemia I, a model for human diseases mediated by 2-oxoacid-utilizing dioxygenases: hepatotoxin suppression by NTBC does not normalize hepatic collagen metabolism.

OBJECTIVES: Medical treatment of tyrosinemia I relies on the herbicide NTBC [Orfadin 2-(2-nitro-4-trifluoromethylbenzoyl)-cyclohexane-1,3-dione], an inhibitor of plant and mammalian 2-oxoacid-utilizing dioxygenases with a collective catalytic cycle ('HAG' mechanism). We hypothesize that NTBC-treated tyrosinemia I is a human model for the pathogenic role of two major enzymes in this class, 4-hydroxyphenylpyruvate dioxygenase (4-HPPD; EC 1.13.11.27) and prolyl 4-hydroxylase (P4-H; E.C. 1.14.11.2), essential for tyrosine and collagen metabolism, respectively. METHODS: In a patient with established tyrosinemia I, we monitored the in vivo activities of 4-HPPD and P4-H via five biomarkers before and during NTBC medication. Hypothesis testing at the molecular level was performed by computational modeling of NTBC binding to the crystal structure-derived active site of 4-HPPD, and then relating these findings to our experimental results and to known P4-H data. RESULTS: NTBC rapidly normalized the biomarkers for 4-HPPD activity. However, those for P4-H activity remained uniformly elevated after one hundred days on NTBC, the PIIINP biomarker even increasing above its grossly abnormal, initial level. This selective enzyme inhibition despite a collective catalytic cycle is attributed to the conformation of NTBC, which only fits the active site of 4-HPPD, as confirmed by its crystal structure. CONCLUSIONS: Normalization of hepatic collagen formation, highly desirable in all fibrotic liver diseases, is not achieved by NTBC in tyrosinemia I. By establishing the molecular cause for this failure, our results also establish a rational approach to identify inhibitors that achieve that goal, either by joint 4-HPPD / P-4H inhibition, or by inhibition of only P-4H.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed2002

Cobalamin C disease presenting as hemolytic-uremic syndrome in the neonatal period.

Anew case of cobalamin C disease associated with hemolytic-uremic syndrome (HUS) in the neonatal period is described. A 28-day-old boy presented with failure to thrive, hypotonia, pancytopenia, and features of HUS (microangiopathic hemolytic anemia, thrombocytopenia, and renal failure). The possibility of the diagnosis of an underlying vitamin B12 disorder was prompted by evidence of megaloblastic changes on the peripheral smear and by finding in the literature a suggested association of neonatal HUS with this cobalamin-related metabolic disorder. Amino acid analysis showed elevated homocysteine levels in the plasma and increased levels of both homocysteine and methyl malonic acid in the urine. Diagnosis of cobalamin C disease was confirmed by complementation studies using skin fibroblasts. Therapy included parenteral hydroxocobalamin, carnitine, and leucovorin calcium (folinic acid). Cobalamin C disease should be considered in the diagnosis of patients presenting with HUS in infancy who have unexplained megaloblastosis, pancytopenia, neurologic impairment, and failure to thrive. Early diagnosis and institution of therapy may be effective in improving survival and quality of life.

Diagnosis, Differential↗
PubMed2002

The endocrine system in diabetes mellitus.

The pathophysiology of diabetes mellitus is complex and not fully understood. However, it emerges as an abnormal metabolic condition associated with a systemic damage to the vascular bed. Cumulative evidence also reveals that the endocrine system is not intact in patients with diabetes mellitus. It is not clear whether the changes observed in the endocrine system represent a primary defect or reflect the effects of the impaired insulin action and abnormal carbohydrate and lipid metabolism on the hormonal milieu. Review of the literature reveals that the function of the entire endocrine system including the functions of hormones from the hypothalamus, pituitary, adrenal, thyroid, parathyroid, the vitamin D system, the gonads, and the endocrine function of the adipose tissue, is impaired. Good metabolic control and insulin treatment may reverse some of these abnormalities. It remains unanswered as to what extent these changes in the endocrine system contribute to the vascular pathologies observed in individuals affected by diabetes mellitus and whether part of the abnormalities observed in the endocrine system reflect a basic cellular defect in the diabetic syndrome.

Diabetes Mellitus, Type 1↗