Angiogenesis and immunity: a bidirectional link potentially relevant for the monitoring of antiangiogenic therapy and the development of novel therapeutic combination with immunotherapy.

The immune system regulates angiogenesis in cancer with both pro- and antiangiogenic activities. The induction of angiogenesis is mediated by tumor-associated macrophages and myeloid-derived suppressor cells (MDSC) which produce proinflammatory cytokines, endothelial growth factors (VEGF, bFGF…), and protease (MMP9) implicated in neoangiogenesis. Some cytokines (IL-6, IL-17…) activated Stat3 which also led to the production of VEGF and bFGF. In contrast, other cytokines (IFN, IL-12, IL-21, and IL-27) display an antiangiogenic activity. Recently, it has been shown that some antiangiogenic molecules alleviates immunosuppression associated with cancer by decreasing immunosuppressive cells (MDSC, regulatory T cells), immunosuppressive cytokines (IL-10, TGFß), and inhibitory molecules on T cells (PD-1). Some of these broad effects may result from the ability of some antiangiogenic molecules, especially cytokines to inhibit the Stat3 transcription factor. The association often observed between angiogenesis and immunosuppression may be related to hypoxia which induces both neoangiogenesis via activation of HIF-1 and VEGF and favors the intratumor recruitment and differentiation of regulatory T cells and MDSC. Preliminary studies suggest that modulation of immune markers (intratumoral MDSC and IL-8, peripheral regulatory T cells…) may predict clinical response to antiangiogenic therapy. In preclinical models, a synergy has been observed between antiangiogenic molecules and immunotherapy which may be explained by an improvement of immune status in tumor-bearing mice after antiangiogenic therapy. In preclinical models, antiangiogenic molecules promoted intratumor trafficking of effector cells, enhance endogenous anti-tumor response, and synergyzed with immunotherapy protocols to cure established murine tumors. All these results warrant the development of clinical trials combining antiangiogenic drugs and immunotherapy.

Interactions between morpholinyl anthracyclines and DNA. The crystal structure of a morpholino doxorubicin bound to d(CGTACG).

Anthracycline antibiotics daunomycin and adriamycin are among the most widely used in cancer chemotherapy and DNA is believed to be the primary target of their biological action. The crystal structure of a morpholino derivative of adriamycin bound to the DNA hexamer d(CGTACG) has been determined at 1.5 A resolution. The complex crystallizes in space group P1 with unit cell dimensions a = 18.01 A, b = 18.83 A, c = 27.65 A, alpha = 92.6 degrees, beta = 100.5 degrees, gamma = 94.9 degrees and there are two drug molecules bound per duplex. Morpholino derivatives differ greatly from their parent compounds in their biological and pharmacological properties. Structural comparison of this complex with the series of previously reported anthracycline-DNA complexes offers an opportunity for studying relationships between structure and function. The anthracycline chromophore intercalates at the CpG step and DNA distortions from a B-type conformation are similar to those observed in the other DNA-anthracycline complexes. Interactions between drug and DNA show no differences at the intercalation site, while in the minor groove they are significantly affected by the presence of the bulky morpholinyl moiety on the anthracycline amino sugar. The binding site involves four base-pairs and the absence of a positive charge on the amino sugar appears to influence the hydration pattern on both grooves. The two halves of the duplex are symmetrically related by a non-crystallographic 2-fold axis but they are not equivalent. In one half, one magnesium cluster bridges both drug and DNA, further stabilizing the complex.

Retroviral-mediated gene transfer of a mutant H-ras gene into normal human bone marrow alters myeloid cell proliferation and differentiation.

To investigate the effects of mutant ras expression on the growth and differentiation of normal human bone marrow, we used retrovirus-mediated gene transfer. A retrovirus (HR-1) containing a mutant ras gene (H12-ras) in addition to the selectable neo gene was transferred by cocultivation of a packaging cell line with long-term cultures of normal human bone marrow. Controls were established by cocultivating aliquots of the same bone marrow with a retrovirus (VSN-2) containing only neo. The efficiency of gene transfer, as determined by the percentage of G418-resistant colony-forming units-granulocyte/macrophage (CFU-GM) immediately after termination of cocultivation, was similar: 8 +/- 4% with HR-1 and 5 +/- 3% with VSN-2. After a further week in long-term culture, there was an increase in the number and percentage of G418-resistant CFU-GM in both the HR-1-infected and VSN-2-infected marrows. Thereafter, the numbers of G418-resistant CFU-GM declined, becoming undetectable at 4 weeks. The time course of the production of G418-resistant colonies was not significantly different in HR-1- and VSN-2-infected marrows, indicating that H12-ras did not alter the proliferation of normal CFU-GM. However, the total cellularity of HR-1-infected marrow cultures was significantly greater than that of VSN-2-infected marrow cultures. This was due to increased cellular proliferation of HR-1-infected cultured cells, since differential counts showed a significant increase in myeloid blast cells together with a slight reduction in mature myeloid cells in HR-1-infected marrow compared to baseline and to VSN-2-infected marrow. No leukemic blast cell colonies were grown from HR-1-infected marrows or control marrows, and HR-1 infection did not confer serum independence. These data show successful retroviral infection of normal bone marrow progenitor cells and suggest that expression of mutant H12-ras in such cells results in enhanced proliferation of early myeloid cells at the expense of differentiation.

31P NMR study of daunorubicin-d(CGTACG) complex in solution. Evidence of the intercalation sites.

The interaction of daunorubicin with the self-complementary DNA fragment d(CGTACG) was studied by 31P NMR spectroscopy. The individual phosphates have been assigned for the nucleotide and the complex and signals from bound and free species in slow exchange at 19 degrees C were detected. In solution, the hexanucleotide binds two molecules of daunorubicin, which intercalate in the d(CG) sequence at both ends of the helix. Evidence for local deformations of the backbone at the sites of C5pG6, C1pG2 and G2pT3 phosphates is given. The binding constants for the stepwise equilibrium and the rate of dissociation of the intercalated duplex were also determined.

Lack of stereospecificity of some cellular and viral enzymes involved in the synthesis of deoxyribonucleotides and DNA: molecular basis for the antiviral activity of unnatural L-beta-nucleosides.

Among enzymes involved in the synthesis of nucleotides and DNA, some exceptions have recently been found to the universal rule that enzymes act only on one enantiomer of a chiral substrate and that only one of the enantiomeric forms of chiral molecules may bind effectively at the catalytic site, displaying biological activity. The exceptions include: herpes virus thymidine kinases, cellular deoxycytidine kinase and deoxynucloside mono- and diphosphate kinases, cellular and viral DNA polymerases, such as DNA polymerase alpha, terminal transferase and HIV-1 reverse transcriptase. The ability of these enzymes to utilize unnatural L-beta-nucleosides or -nucleotides as substrate may be exploited from chemotherapeutic point of view.

L-thymidine is phosphorylated by herpes simplex virus type 1 thymidine kinase and inhibits viral growth.

We have demonstrated that herpes simplex 1 (HSV1) thymidine kinase (TK) shows no stereospecificity for D- and L-beta-nucleosides. In vitro, L enantiomers are not recognized by human TK, but function as specific substrates for the viral enzyme in the order: L-thymidine (L-T) >> 2'-deoxy-L-guanosine (L-dG) > 2'-deoxy-L-uridine (L-dU) > 2'-deoxy-L-cytidine (L-dC) > 2'-deoxy- L-adenosine (L-dA). HSV1 TK phosphorylates both thymidine enantiomers to their corresponding monophosphates with identical efficiency and the Ki of L-T (2 microM) is almost identical to the Km for the natural substrate D-T (2.8 microM). The L enantiomer reduces the incorporation of exogenous [3H]T into cellular DNA in HeLa TK-/HSV1 TK+ but not in wild-type HeLa cells, without affecting RNA, protein synthesis, cell growth, and viability. L-T markedly reduces HSV1 multiplication in HeLa cells. Our observations could lead to the development of a novel class of antiviral drugs characterized by low toxicity.

Ribavirin conjugated with lactosaminated poly-L-lysine: selective delivery to the liver and increased antiviral activity in mice with viral hepatitis.

Ribavirin (RIBV) is a useful drug in the treatment of chronic type C hepatitis but displays a toxicity for red blood cells (RBC), which limits its dosage and necessitates withdrawal in some patients. Selective concentration of RIBV in liver should improve therapeutic results. Liver targeting can be achieved by coupling the drug to galactosyl-terminating peptides, which specifically enter hepatocytes. In the present work, we conjugated RIBV to lactosaminated poly-L-lysine (L-Poly(Lys)), a hepatotropic carrier enabling intramuscular (IM) administration of conjugates. The L-Poly(Lys)-RIBV conjugate had a heavy drug load (312-327 microg of RIBV in 1 mg of conjugate) and was very soluble in 0.9% NaCl (200 mg/mL). The conjugate was devoid of acute toxicity in mouse. When incubated with human or mouse blood, it did not release the drug. After IM administration to mice, the conjugate was selectively taken up by the liver, where the drug was released in a pharmacologically active form. This was demonstrated using mice infected with a strain of murine hepatitis virus (MHV) sensitive to RIBV. Coupled RIBV, IM injected, inhibited MHV replication in liver at a daily dose two to three times lower than that of the free drug. In mice IM injected with a conjugate tritiated in the RIBV moiety, the ratios between the levels of radioactivity in liver and RBC were two times higher than in animals injected with free tritiated RIBV. In conclusion, the present results support the possibility that the chemotherapeutic index of RIBV in chronic type C hepatitis can be increased by conjugation with L-Poly(Lys).

The "n-1" model for myelodysplastic syndromes.

Current models of leukaemogenesis tend to visualize this process as consisting of several discrete steps. Since myelodysplastic syndromes (MDS) are, almost by definition, pre-leukaemic disorders, we expect that bone marrow from patients with MDS must contain cells which are one step short of full leukaemic transformation: we designate these cells, for convenience, as "n-1". It should be possible therefore to obtain leukaemic transformation in vitro by introducing into n-1 cells a gene with an appropriate leukaemogenic mutation. We have found, by using as a model system the retrovirus VSN-2 (which carries the neomycin-phosphotransferase gene, neo, which confers resistance to the antibiotic G418), that human bone marrow cells can be successfully transfected in microcultures. Indeed, G418-resistant CFU-CM have been recovered from these cultures for a period of several weeks.

Inhibition of MDR1 gene expression by antimessenger oligonucleotides lowers multiple drug resistance.

The multiple drug resistance of neoplastic cells is mediated by overexpression of the human MDR1 gene, which encodes the transmembrane efflux pump P-glycoprotein. In both cell lines and human tumors the MDR phenotype closely correlates with MDR1 mRNA and P-glycoprotein levels. Reversion of the MDR phenotype was attempted in human colorectal adenocarcinoma doxorubicin (Dx)-resistant cells (Lo Vo/Dx) by long-term administration of an equimolecular mixture of three unmodified ODNs (18mer) targeted to adjacent binding sites of the MDR1 mRNA and carried by a synthetic cationic lipid (DOTAP). Three different experimental parameters were used to evaluate the antimessenger agent's effectiveness in comparison with a random sequence ODN: the level of cell resistance to Dx; the level of P-glycoprotein (determined by flow cytometry); the level of MDR1 mRNA (determined by quantitative RT-PCR). Experimental data indicate that the level of both the MDR1 mRNA and the P-glycoprotein is reduced by approximately 50% by treatment of Lo Vo/Dx cells with a 10 microM total concentration of the aODN mixture every 24 h for 15 days. In agreement with these findings, sensitivity to Dx of the antimessenger agent-treated Lo Vo/Dx cells was almost doubled in comparison with random sequence ODN-treated controls.

Calcium and phosphorus balance in very low birth weight babies on total parenteral nutrition.

A balance study of Ca and P has been performed in 12 Very Low Birth Wt babies receiving prolonged Total Parenteral Nutrition. The mean intake of both minerals was 54.4 mg/kg/day (range 40-70). In order to avoid the formation and precipitation of CaP crystals in the solution, fructose-1,6-diphosphate was used as a source of P. 30 balance studies were performed between the seven and 63 day of life: they were always positive with a mean retention of 47.4 mg/kg/day of Ca and 48.1 mg/kg/day of P. For both minerals, 88% of the amount infused was retained: the correlation between intake and retention was linear and statistically significative (Ca:r = 0.9, p < 0.0001; P:r = 0.68, p < 0.0001). The post-natal and post-conceptional ages of the babies had no influence on Ca and P balance. The blood levels of Ca and P were poorly correlated to both intake and excretion, and were not as indicative of the mineral balance as the retention rates calculated on the basis of the 24 h urinary excretion of the minerals. A very useful test for clinical monitoring of Ca and P balance proved to be the Ca/creatinine and P/creatinine ratios measured on simple urine samples, which were strongly correlated to 24 h excretion. All infants developed radiological signs of mild osteopenia, but there was no case of acute metabolic derangement or rickets. Our data demonstrated that even in sick VLBW infants on TPN it is possible to achieve good retention rates of Ca and P, which are not different from those observed in well VLBW babies fed a 'standard' premature formula.

Prony-Householder method applied to 31P NMR signals: II. Study of conjugates of ara-AMP with lactosaminated albumin.

Conjugates of 9-beta-D-arabinofuranosyladenine 5'-monophosphate (ara-AMP) with lactosaminated albumin (L-SA), obtained by using two different coupling procedures, produce antibodies in rats and mice which display only a small cross-reactivity. 31P NMR signals from the two conjugates have been examined to clarify whether different lysine and histidine residues are involved in the two reaction pathways. The occurrence of different chemical shifts and linewidths between the two conjugates, as evidenced by processing the signals with the Prony-Householder method, indicates the formation of two different complexes.

Hyperhomocysteinemia in renal transplant patients: an independent factor of cardiovascular disease.

Hyperhomocysteinemia (Hcy) is an independent factor of cardiovascular disease, which is the main cause of morbidity and mortality both in uremic and kidney transplant patients. The aim of the study was to determine Hcy, plasminogen activator inhibitor (PAI-1) and lipoprotein (a) (Lp(a)) serum levels in 70 patients with a well functioning renal transplant. We also verified whether these levels were modified by a multivitamin therapy. The genetic polymorphism of the methylenetetrahydrofolate reductase (MTHFR) enzyme which plays a main role in Hcy metabolism, was studied as well. We found Hcy, PAI-1 and Lp(a) levels significantly elevated with respect to healthy control subjects. The thermolabile form of the MTHFR enzyme was linked to higher Hcy levels. After a short time on therapy with B6, B12 and folic acid vitamins, Hcy and PAI-1 decreased to normal levels. The authors conclude that high Hcy levels could be a relevant covariate for cardiovascular disease in transplant patients and they suggest that vitamin supplementation be recommended as a part of therapy.

[Immunocompetence of newborn calves: evaluation of the proliferative response of lymphocytes in vitro to 3 nonspecific mitogens (concanavalin A, phytohemagglutinin, pokeweed mitogen) during the 1st 3 months of life]. / Immunocompétence du veau nouveau-né: évaluation de la résponse lymphocytaire proliférative in vitro à trois mitogenès non spécifiques (concanavaline A, phytohémagglutinine, pokeweed mitogen) au cours des trois premiers mois de vie.

A micromethod technique was used to evaluate in vitro sensitivity of the peripheric bovine lymphocytes obtained from a newly born calf, up to 3 months of age to different non-specific mitogens: Phytohemagglutinin (PHA) Concanavaline A (Con A) and Pokeweed Mitogen (PWM). The results obtained show that the calf lymphocytes respond to the 3 mitogens by a considerable cellular proliferation. The blastogenic response was found at various levels during the first 3 months of life, and appeared to stabilize at levels similar to the adult bovine. Highly sensitive variations were noted in the lymphocyte reactivity, notably with PHA and Con A. These results seem to indicate the existence of periods of T cell immunodeficiency, not only during the first few days after birth, but throughout the first months of the calves' life. It may also be indicative of the interest of immunostimulant therapy during this period, which needs further investigation.

Growth hormone does not prevent catabolic side effects of dexamethasone in extremely low birth weight preterm infants with bronchopulmonary dysplasia--a pilot study.

Recombinant human growth hormone (rhGH) may reduce the catabolic side effects of steroid therapies on children and adults, but this has never been studied in preterm infants. We performed a pilot study on 5 extremely low birth weight preterm infants (gestational age 27 +/- 3 wks, birth weight 824 +/- 160 g) still on mechanical ventilation for bronchopulmonary dysplasia at the postnatal age of 35 +/- 9 days. All were treated for 7 days with dexamethasone (0.5 mg/kg/d i.v.) and subcutaneous rhGH at different doses: 0.1 (n = 1), 0.2 (n = 2) or 0.3 (n = 2) IU/kg/day. Nutrition was kept stable. After 7 days all subjects improved their respiratory condition but body weight remained the same and urinary urea nitrogen and C-peptide were significantly higher (p < 0.001). rhGH intake strongly related to urinary excretion of urea nitrogen (r = 0.78) and C-peptide (r = 0.88). Dexamethasone improves the pulmonary function of very preterm infants with bronchopulmonary dysplasia but induces growth arrest and catabolism which are not prevented, and may be worsened, by rhGH.

Serum Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) in growing preterm infants on enteral nutrition.

We analyzed the range of serum concentrations of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) and their inter-relationships with age and some parameters of nutritional and hormonal status in 46 growing preterm infants on enteral nutrition. 72 nutritional balances were performed, with a cross-sectional study design, at a mean age of 35.3 +/- 17.2 days, equivalent to a mean corrected age (gestational + postnatal age) of 36 +/- 2.3 weeks. Serum concentrations of IGF-I (mean 64 +/- 36 ng/ml) and IGFBP-3 (mean 1.15 +/- 0.53 mg/l) correlated significantly with each other (r = 0.46) and both correlated with body weight (r = 0.43 and 0.34), body length (r = 0.44 and 0.36) and serum concentrations of prealbumin, apolipoprotein A and cholesterol. IGF-I also correlated with urinary excretion of C-peptide (r = 0.32). There was a weak correlation between IGFBP-3 and postnatal age (r = 0.36) but no correlation between IGF-I and IGFBP-3 and correlated age or urinary excretion of growth hormone. In growing preterm infants, at least until 40 weeks of corrected age, serum concentrations of IGF-I and IGFBP-3 seem to be related principally to body weight, body length and nutritional factors, but not to growth hormone.

Acute esotropia from small thalamic hemorrhage.

A 74 year-old patient developed transient acute esotropia, upward gaze palsy and imbalance of standing and gait. Computed Tomography (CT) demonstrated a small left thalamic hemorrhage in the absence of midbrain lesions. The role of thalamic lesion in the genesis of monocular supranuclear palsy is discussed.

The "kangaroo-mother" method: evaluation of an alternative model for the care of low birth weight newborns in developing countries.

The "kangaroo-mother" method, that is nursing babies by continuously keeping them wrapped at the mother's breasts, has been proposed as an "appropriate technology" for the care of low birth weight (LBW) newborns in developing countries. We evaluated the effectiveness of this method as an alternative hospital care model in the Special Care nursery of the Central Hospital of Mapto, Mozambique. One hundred LBW newborns (mean birth weight 1329 g, SD +/- 208 g) were consecutively admitted to the "kangaroo-mother" section of the unit at the mean postnatal age of 11.6 days. Ninety-five of them were discharged alive after a mean period of 16.3 days of "kangaroo" nursing. During this period they were exclusively breast fed and their mean weight gain was 12.8 g/day. Besides being very effective in improving survival, this method favored the development of early mother-infant relations, which are certainly very important for the long term well-being of the child.

Infiltrating cribriform carcinoma of the breast. A clinico-pathologic and immunohistochemical study of 5 cases.

Clinical and pathological features of five cases of infiltrating cribriform carcinoma (ICC) of the breast observed between 1990 and 1994 are reported. Using histological criteria by Page et al., three cases of pure ICC and two cases of mixed ICC were identified. In the mixed forms, the cribriform component made up about 80% of the neoplasm. After clinical follow-up, from one to five years long, no relapses, axillary lymph nodes or distant metastases were found, even in two cases with very large neoplasms (20 cm and 10 cm, respectively). This report confirms that this type of carcinoma has a very favorable prognosis, especially pure and mixed forms with a predominant cribriform component. Clinical and histological features make ICC a peculiar form of breast carcinoma.

[Cat retroviruses and human retroviruses: elements of comparison]. / Rétroviroses du chat et rétroviroses de l'homme: éléments de comparaison.

Following emotional head-lines of certain articles in the press, making believe that the cat could be susceptible to the AIDS virus, the authors present elements of comparison between principal feline retroviruses (the feline leucosis virus and the feline immunodeficiency virus) and the two human immunodeficiency viruses (HIV). The feline leucosis virus in differentiated from the human and the feline immunodeficiency viruses by its virological, pathological and epidemiological characteristics. Being close to the AIDS virus in the taxonomy of retroviruses, the feline immunodeficiency virus (FIV) presents a number of similarities with the HIV. Therefore, the FIV could give rise to interests in its use as a model in the study of AIDS. Whatever the factors of resemblances may be, there are no elements of present knowledge in favor of an inter-species contamination (cat-man); on the contrary, these viruses demonstrate a marked species specificity.

[Metabolic, hormonal and nutritional effects of long-term theophylline therapy in preterm infants: a case-control study]. / Effetti metabolici, ormonali e nutrizionali della terapia prolungata con teofillina nei nati pretermine: uno studio caso-controllo.

Theophylline is widely used in preterm newborns for the prevention of idiopathic apnoeas, but few controlled studies have evaluated its effects on the nutritional and hormonal status of the infant. For this reason we have studied the effect of long term theophylline administration on 16 laboratory parameters concerning the metabolism of proteins, glucose, lipids, hormones and the glomerular function (blood: hemoglobin, glucose, albumin, prealbumin, urea nitrogen, creatinine, cholesterol, triglycerides, apolipoproteins A-I and B-100, IGF-I, IGFBP-3; urine: urea nitrogen, creatinine, C-peptide, GH). A case-control study was performed on 18 healthy preterm infants who were receiving oral theophylline for the prevention of idiopathic apnoeas. The mean duration of therapy at the moment of the balance study was 31 days (SD 12, range 12-51), the mean daily dose was 4.2 mg/kg (SD 1.0), the plasma range of theophylline concentration was 5 to 15 mg/l. As controls, 18 healthy preterm infants of comparable post-conceptional age, body weight and calories/protein intake at the moment of the study, were selected if they had been never treated with theophylline. No statistically significant differences were found between the two groups for the growth velocity or any of the parameters studied. The only notable exception was hemoglobin, which was significantly lower in theophylline treated infants (mean values 10.5 vs 12.7 g/dl, p 0.005 at t test). In synthesis, long term theophylline treatment in preterm infants seems to be safe from the point of view of growth, glucose, protein and lipid metabolism, hormones and glomerular function, but further studies are needed on the effects of theophylline on neonatal erythropoiesis.