Metastatic malignant melanoma.

Metastatic malignant melanoma is an incurable malignancy with extremely poor prognosis. Patients bearing this diagnosis face a median survival time of approximately 9 months with a probability of surviving 5 years after initial presentation at less than 5%. This is contrasted by the curative nature of surgical resection of early melanoma detected in the skin. To date, no systemic therapy has consistently and predictably impacted the overall survival of patients with metastatic melanoma. However, in recent years, a resurgence of innovative diagnostic and therapeutic developments have broadened our understanding of the natural history of melanoma and identified rational therapeutic targets/strategies that seem poised to significantly change the clinical outcomes in these patients. Herein we review the state-of-the-art in metastatic melanoma diagnostics and therapeutics with particular emphasis on multi-disciplinary clinical management.

Immune cells in the human choroid.

AIM: To characterise the leucocytes in human macular choroid with and without drusen, and in eyes with advanced age-related macular degeneration (AMD) with fibrovascular scarring (FVS). METHODS: Ten eyes from nine donors (range 55-91 years of age) were obtained from an eye bank within 38 h post mortem. Fixed macular biopsies were sectioned, stained immunochemically and examined for the presence of leucocyte antigens CD45, CD4, CD8, CD14 and CD83. RESULTS: Four eyes without drusen, four eyes with drusen and two eyes with FVS contained 23.9 (SD 6.2)%, 27.5 (7.2)%, and 19.3 (11.3)% CD45-positive cells, respectively. The corresponding percentages for CD4-positive cells were 5.4 (4.3), 8.9 (3.0) and 7.5 (8.1); for CD8-positive cells, 3.8 (0.7), 6.8 (2.2) and 6.3 (2.1); and for CD14-positive cells, 3.7 (3.7), 3.6 (1.6) and 2.6 (3.6), respectively. The authors found CD83-positive cells solely in one of the two FVS eyes examined that had the more severe form of scarring. CONCLUSION: Human choroid contains similar amounts of CD4-positive cells and monocytes irrespective of the presence of drusen, but CD8-positive cells are more abundant in macular choroid with drusen. The presence of haematopoietic cells in the macular choroid provides further evidence for the possible participation of inflammatory cells in pathogenesis of AMD.

Testing the safety of clinical-grade mature autologous myeloid DC in a phase I clinical immunotherapy trial of CML.

BACKGROUND: We conducted a phase I clinical immunotherapy trial of CML to evaluate the safety of a clinical-grade leukemic DC product standardized for purity and mature phenotype. METHODS: We injected autologous DC into patients in late chronic or accelerated phases of CML. The patients received mature CD83+ and bcr-abl+ DC prepared from CD14+ cells. Two cohorts of three patients received four injections each of 3 x 10(6) DC and 15 x 10(6) DC/injection, respectively. The first patient was studied before imatinib mesylate (IM) was available, four patients were treated concurrently with IM therapy and one did not tolerate the IM and was off the drug at the time of DC therapy. IM effects on WBC counts precluded DC preparation in numbers sufficient for further dose escalation. The first patient received DC s.c. and all subsequent patients received DC into a cervical lymph node under ultrasound guidance. RESULTS: DC injections were well tolerated. We observed no clinical responses. T cells drawn later in the course of therapy were more sensitive to stimulation by CML DC in vitro. DISCUSSION: The increase in T-cell sensitivity to CML-specific stimulation that accompanied active immunization by CML DC justifies further clinical studies, possibly with modifications such as an increased frequency and number of DC injections.

Clinical-grade manufacturing of DC from CD14+ precursors: experience from phase I clinical trials in CML and malignant melanoma.

BACKGROUND: We evaluated a clinical-grade protocol for the manufacture of mature DC from CD14 + precursors derived from normal donors and patients suffering from CML and stage IV malignant melanoma. We manufactured six products for CML patients and five for melanoma patients and administered them as vaccines in phase I clinical trials. METHODS: We isolated CD 14+ cells from apheresis products by immunomagnetic separation and incubated them in X-VIVO 15' medium supplemented with human AB serum, GM-CSF and IL-4 for 7 days, and with additional tumor necrosis factor (TNF)-a, IL-lIf, IL-6 and prostaglandin E2 for 3 days. Some cells were electroporated and transfected with mRNA isolated from melanoma tissue. DC were characterized by flow cytometry for the expression of CD83, CD86 andCD14. RESULTS: CD14+ cells constituted 14.4+/-6.2% (mean + SD) of nucleated cells in apheresis products and 98.3+/- 3.6% of isolated cells. Normal DC and CML DC were 77.4+/-7.3% CD83+ and 93.5+/- 7.0% CD86+. Corresponding values for electroporated DC from melanoma patients were 66.1 + 7.2% and 94.1 + 7.8%. The yield of CD83+ DC from isolated CD14+ cells was 18.1 + 7.2% for normal and CML patients and 9.8 + 3.7% for melanoma patients. DC viability was 92.7 + 5.8%; after cryopreservation and thawing it was 77+/-13.5%. DISCUSSION: Our method yielded viable and mature DC free of bacteria and mycoplasma. This robust and reproducible method provides cells of consistent phenotype and viability. Cryopreservation in single-dose aliquots allows multiple DC vaccine doses to be manufactured from a single apheresis product.

Can there be a meaningful participation of Croat expatriates in Croatian science?

The author discusses the possible role for Croat expatriate scientific community in Croatian science. He argues that proper leadership could engage Croatian expatriate scientific community in supporting the foundation of a multidisciplinary science institute in Split, Croatia. The institute could play a key role in regional economic development focused on health, energy, and environment. Establishment and maintenance of a program of such magnitude requires a diminished and more flexible role of the government and introduction of the private sector in a government-private partnership. Development of necessary attitudes and economic base will take time.

Engineering dendritic cell grafts for clinical trials in cellular immunotherapy of cancer: example of chronic myelogenous leukemia.

Dendritic cells are pivotal regulators of immune reactivity and immune tolerance. The observation that dendritic cells can recruit naive T-cells has invigorated cancer immunology and stimulated clinical trials of dendritic cells in immunotherapy. However, variables inherent in preparation and use of dendritic cell grafts remain to be tested. Here we discuss the role of ex vivo dendritic cell processing for in vivo antigen presentation in clinical trials. As an example of the complexity in a clinical trial of dendritic cell vaccines, we present our ongoing trial in immunotherapy of chronic myelogenous leukemia.

Maturation of human dendritic cells as sulfasalazine target.

AIM: Sulfasalazine, a nonsteroidal anti-inflammatory drug, is effective in treating some autoimmune diseases, but its mechanism of action is unclear. To determine whether dendritic cells could be a possible target of the drug, we studied the effects of sulfasalazine and its metabolites, aminosalicylate and sulfapyridine, on in vitro maturation (terminal differentiation) of human myeloid dendritic cells. METHODS: We prepared immature dendritic cells by incubating CD14-positive cells in the presence of granulocyte- macrophage colony-stimulating factor and interleukin (IL)-4. The cells were matured by addition of tumor necrosis factor (TNF)-a, IL-1 beta, and prostaglandin E2 in the presence of sulfasalazine or its metabolites -- aminosalicylate and sulfapyridine, or their combinations. We quantified the effect of drugs on the dendritic cell characteristics, such as stimulation of autologous and allogeneic pan-T cell proliferation, surface marker phenotype, IL-12 p40 subunit secretion, and activation of nuclear transcription factor (NF)-kappa B. RESULTS: Dendritic cells treated with sulfasalazine (1.25 micromol/L or 2.5 micromol/L) could not stimulate T cells (p<0.028, two-sided paired t-test). In distinction to drug-free maturing dendritic cells, 2.5 micromol/L sulfasalazine upregulated the levels of CD14 and CD68 and downregulated the levels of CD40, CD80, and CD83 (for all CD markers, p<0.03 for difference between measurements in the absence and the presence of sulfasalazine). From concentration-dependent changes in CD83 expression, we found an apparent ID50 >>1.5 micromol/L sulfasalazine. The apparent ID50 value for aminosalicylate-inhibited maturation was 4 micromol/L. Sulfapyridine had no effect. At 1.25 micromol/L, sulfasalazine largely inhibited NF-kB activation in dendritic cells. CONCLUSION: Maturing human dendritic cells are hundred-fold more sensitive to sulfasalazine than T cells and NK cells and the most sensitive human cells described so far. Thus, dendritic cell maturation is an important target of sulfasalazine. Because of the role of dendritic cells in (auto)immunity, inhibition of their maturation might provide a target for further optimization of sulfasalazine therapy.

Maturation of dendritic cells infected by recombinant adenovirus can be delayed without impact on transgene expression.

Adenovirus-mediated gene transfer to dendritic cells is highly efficient and often used, but the relationship among cell maturation, viral infection and expression of a transferred gene remains unclear. To study this relationship, we introduced a recombinant replication-defective adenovirus encoding the gene for green fluorescent protein to normal human immature myeloid dendritic cells. We induced maturation by the addition of TNF-alpha, IL-1beta, IL-6 and prostaglandin E2 to the medium and assessed cell maturity by the levels of the secreted p40 subunit of IL-12 and of membrane-bound CD83. We quantified the efficiency of gene expression by GFP fluorescence and analyzed the data by a mixed-model analysis of variance; the model explained more than 97% of the effects. CD83 expression and p40 secretion depended solely on incubation time and maturation medium. The cells cultured in the absence of maturation medium remained immature and maintained the ability to respond to the later addition of the maturation irrespective of adenovirus infection and transferred gene expression. This expression was independent of cell maturation. In comparison with mature cells, the transferred gene was expressed in immature dendritic cells with a lag compatible with the less effective initial step (infection and/or gene transfer) in the absence of the maturation medium rather than less effective later GFP synthesis. Expression of CD83 and p40 were unaffected by adenovirus infection and transferred gene expression. Thus, immature dendritic cells infected with recombinant adenoviruses can be matured when desired after transferred gene expression.

Transgenic interleukin 2 secreted by CML dendritic cells stimulates autologous T(H)1 T cells.

BACKGROUND: We investigated if dendritic cells (DC), derived from patients suffering from chronic myeloid leukemia (CML) could be modified by recombinant replication-defective adenoviruses to express functional interleukin 2 (IL-2). Such modification might confer onto antigen-presenting cells the ability to stimulate expansion of effector cells. METHODS: To quantify the infection efficiency of CML dendritic cells (CML-DC) by recombinant adenovirus, we measured the expression of green fluorescent protein (GFP) gene contained in the virus. In CML-DC infected with an adenovirus containing the IL-2 gene, we evaluated their ability to secrete IL-2 and stimulate proliferation of autologous T cells. RESULTS: Uninfected CML-DC and normal DC secreted similar amounts of IL-12 and stimulated similarly efficient autologous mixed leukocyte reaction. Immature CML-DC infected by an adenovirus containing the gene for IL-2 secreted large amounts of IL-2 and stimulated proliferation of autologous T cells more efficiently than the corresponding CML-DC alone. High levels of interferon eta, but not of IL-4, in cell culture supernates indicated that the proliferating cells were T(H)1. Infected mature CML-DC were more effective than infected immature CML-DC, showing that T cell stimulation by mature DC and by IL-2 was additive. DISCUSSION: CML-DC can be modified genetically and functionally by recombinant replication-defective adenoviruses, providing new possibilities for clinical trials in dendritic cell-based immunotherapy.

Maturation of human monocyte-derived dendritic cells studied by microarray hybridization.

We compared the transcript profiles of human myeloid immature dendritic (IDC) cells and mature dendritic cells (MDC) by hybridization of cell-derived cDNA to DNA probes immobilized on microarrays. The microarrays contained probes for 4110 known genes. We report maturation-dependent changes in transcription of clusters of differentiation, cytokines, cytokine receptors, chemokines, chemokine receptors, neuropeptides, adhesion molecules, and other genes. We identified 1124 transcripts expressed in IDC and 1556 transcripts expressed in MDC. Maturation increased the levels of 291 transcripts twofold or more and reduced the levels of 78 transcripts to one-half or less than in IDC. We identified a concerted maturation-stage-dependent transcription of the variable chains of the members of the gamma-chain-cytokine receptor family IL-4R, IL-7R, and IL-15R. Also, we found the reversal of the ratio of transcripts for galectin-3 and galectin-9 upon maturation. We identified maturation-dependent changes in the levels of transcripts for numerous genes encoding proteins previously undetected in dendritic cells such as indoleamine 2,3-deoxygenase, Epstein-Barr virus induced protein 3 and kinesin-2. Moreover, MDC transcribed and translated insulin like growth factor-1 receptor, transforming growth factor alpha, and neuropeptide Y.

Cyclooxygenase-independent inhibition of dendritic cell maturation by aspirin.

When immature human myeloid dendritic cells were differentiated in vitro in the presence of aspirin, they were unable to stimulate T-cell proliferation. Aspirin and its major metabolite salicylate changed the surface marker phenotype of dendritic cells. The drugs particularly suppressed the levels of CD83 and the secreted p40 unit of interleukin-12 (IL-12), both markers of mature dendritic cells; 50% inhibitory concentration (IC50) values were 2.5 mM, a concentration more than 100 times greater than the concentration at mid-point inhibition (ID50) value for inhibition of prostaglandin synthesis. Concomitantly, the levels of CD14, a marker of monocytes/macrophages, increased above the levels found in immature dendritic cells. Cyclooxygenase inhibitors ketoprofen, indomethacin and NS-398 had no effect at concentrations more than a thousand-fold higher than their IC50 values. The effects were independent of the presence of prostaglandin E2 in the medium. Salicylates suppressed activation of the nuclear transcription factor kappaB, which regulates dendritic cell differentiation, but their effects on mature dendritic cells were negligible. Hence, aspirin inhibits dendritic cell function by inhibiting their terminal differentiation at concentrations achieved in the blood of patients chronically treated with high-dose aspirin.

Priming tissue-specific cellular immunity in a phase I trial of autologous dendritic cells for prostate cancer.

We attempted to induce therapeutic immunity against prostate-derived tissues in patients suffering from progressive hormone-refractory metastatic prostate carcinoma. Thirteen patients were treated with two infusions, 1 month apart, of autologous dendritic cells (APC8015) preexposed ex vivo to PA2024, a fusion protein consisting of human granulocyte/macrophage-colony stimulating factor (GM-CSF) and human prostatic acid phosphatase (PAP). The infusions were followed by three s.c. monthly doses of PA2024 without cells. Three groups of patients each received PA2024 at 0.3, 0.6, or 1.0 mg/injection. All Ps were two-sided. Treatment was well tolerated. After infusions of APC8015, patients experienced only mild (grade 1-2) short-lived fever and/or chills, myalgia, pain, and fatigue. One patient developed grade 3 fatigue. Four patients developed mild local reactions to s.c. PA2024. Twelve patients were evaluable for response to treatment. Circulating prostate-specific antigen levels dropped in three patients. T cells, drawn from patients after infusions of APC8015, but not before, could be stimulated in vitro by GM-CSF (P = 0.0004) and PAP (P = 0.0001), demonstrating broken immune tolerance against these two normal proteins. Injections of PA2024 did not influence the reactivity of T cells against PAP and GM-CSF. However, antibodies to GM-CSF and, to a much lesser extent, to PAP reached maximum titers only after two or even three injections of PA2024, showing that directly injected PA2024 was involved in stimulation of humoral immunity. Dendritic cells exposed to antigen ex vivo can induce antigen-specific cellular immunity in prostate cancer patients, warranting further studies of this mode of immunotherapy.

Joining together to combat poverty.

The International Poverty and Health Network (IPHN) was created in December 1997 following a series of conferences organized by the World Health Organization, with the aim of integrating health into plans to eradicate poverty. Around 1.3 billion people live on less than US$1 per day. Of the 4.4 billion people in developing countries nearly 60% lack access to sanitation, 30% do not have clean water, 20% have no health care, and 20% do not have enough dietary energy and protein. Even among rich nations there are gross socioeconomic inequalities. Many children are robbed of their physical and mental potential through poverty. Expressed in constant 1963 US dollars, an average Croatian family needed the annual income of US$894 to meet the poverty line in 1960 and US$9,027 in 1995. Accordingly, 9-25% of Croatian households were below the poverty line between 1960 and 1995. The increase in the poverty rate after 1991 was compounded by the war that destroyed almost a third of industrial capacity and infrastructure. Dissipation of the communist economy and inadequate privatization have contributed to the increase in unemployment rate, corruption, and other social ills. IPHN invited Croatian Medical Journal to publish this editorial to help push the issue of poverty up political and medical agendas on a global level. We argue that a factor contributing to the failure of most large-scale programs against poverty to date is the excessive emphasis on material and infrastructure assistance at the expense of spiritual, moral, and intellectual development.

Optimizing preparation of normal dendritic cells and bcr-abl+ mature dendritic cells derived from immunomagnetically purified CD14+ cells.

The goal of this work was to optimize dendritic cell (DC) preparations obtained from patients suffering from chronic myeloid leukemia (CML) and compare them with DC prepared from normal CD14+ mononuclear cells (MNC). We studied normal DC and bcr-abl+ leukemic DC (CML-DC) yields, expression of membrane molecules, differentiation status, and ability to stimulate T cells. We isolated DC precursors from PBMC by CD14-specific immunoadsorption and cultured them for 7 days in GM-CSF and IL-4, followed by a 3-day incubation to fully differentiate the cells. We evaluated cultures of CML-DC using RPMI 1640 medium supplemented with FBS and X-VIVO 15 medium containing human AB serum. In contrast to cells matured in RPMI 1640, virtually all cells incubated in X-VIVO 15 expressed CD83, a marker of mature DC. CML-DC and normal DC were indistinguishable in expression of CD83, resulting in the highest percentage reported so far. The yields of normal DC and CML-DC from CD14+ cells were indistinguishable. The percentage of bcr-abl+ cells in PBMC varied among patients between 65% and 97% and the final CML-DC preparations were >98% bcr-abl+ the highest purity of bcr-abl+ cells to date. Normal DC and CML-DC were equally effective in stimulating proliferation of allogeneic and autologous T cells. These techniques provide highly enriched, mature, functional CML-DC.

Dexamethasone inhibits dendritic cell maturation by redirecting differentiation of a subset of cells.

To investigate how corticosteroids affect differentiation of human dendritic cells (DC) in a defined inflammatory environment, we incubated immature DC with dexamethasone in the presence of tumor necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta), and prostaglandin E2. Dexamethasone inhibited differentiation into mature DC, as indicated by the reduced expression of antigen-presenting molecules, costimulatory and adhesion molecules, a marker of mature DC, and IL-12. Dexamethasone increased expression of CD14, CD36, and CD68, molecules characteristic of monocytes/macrophages and induced CD14+CD83- cells, a subset distinct both from immature DC and mature DC. The effects were concentration-dependent, with ID50 values between 2 and 30 nM dexamethasone. Unlike T and B cells, in DC dexamethasone induced no apoptosis, although it suppressed activated nuclear transcription factor NF-kappaB. Dexamethasone reduced the ability of DC to stimulate proliferation of allogeneic T cells in proportion to the level of CD14+CD83- cells in the population. CD83+ cells, isolated from dexamethasone-treated populations, retained the synthesis of IL-12 and the ability to stimulate proliferation of allogeneic T cells. Our data demonstrate that the dominant effect of the drug was redirecting differentiation of a subset of cells despite the presence of inflammatory cytokines. The observed ID50 values indicate that inhibition of DC differentiation might contribute significantly to in vivo immunosuppression by chronic administration of corticosteroids.

Differences in metabolism of 5-fluorouracil and 5-fluorouridine and regulation by glucosamine in human colon cancer multicell tumor spheroids.

Glucosamine (GlcN) modulates fluoropyrimidine metabolism and enhances cytotoxicity of 5-fluorouridine (FUrd), but not of 5-fluorouracil (FUra), in human tumor models. To elucidate the underlying metabolic differences between FUra and FUrd, by the use of 19F and 31P NMR spectroscopy we studied these drugs in multicell tumor spheroids (MTS) formed by human colon carcinoma cells HT-29. This experimental system allowed detailed kinetic measurements of anabolic intracellular phosphates and fluorophosphates over periods of up to 2 days. Time-dependent NMR data were reduced and interpreted by the use of nonlinear compartmental models which yielded numerical values for the empirical rate constants characterizing mass transfer among the compartments. An analysis of these rate constants indicated qualitative and quantitative differences in the metabolism of FUra and FUrd and in the effects of GlcN on these drugs. The enhanced generation of FUDP-hexoses was a predicted effect of GlcN, but inhibited formation of fluorouridine diphosphates and fluorouridine triphosphates in FUra-treated MTS, and the magnitude of stimulation of fluoropyrimidine incorporation into macromolecules in FUrd-treated MTS were not predicted.

Recombinant human thrombopoietin in combination with granulocyte colony-stimulating factor enhances mobilization of peripheral blood progenitor cells, increases peripheral blood platelet concentration, and accelerates hematopoietic recovery following high-dose chemotherapy.

Lineage-specific growth factors mobilize peripheral blood progenitor cells (PBPC) and accelerate hematopoietic recovery after high-dose chemotherapy. Recombinant human thrombopoietin (rhTPO) may further increase the progenitor-cell content and regenerating potential of PBPC products. We evaluated the safety and activity of rhTPO as a PBPC mobilizer in combination with granulocyte colony-stimulating factor (G-CSF) in 29 breast cancer patients treated with high-dose chemotherapy followed by PBPC reinfusion. Initially, patients received escalating single doses of rhTPO intravenously (IV) at 0.6, 1.2, or 2.4 micrograms/kg, on day 1. Subsequent patients received rhTPO 0.6 or 0.3 micrograms/kg on days -3, -1, and 1, or 0.6 micrograms/kg on days -1 and 1. G-CSF, 5 micrograms/kg IV or subcutaneously (SC) twice daily, was started on day 3 and continued through aphereses. Twenty comparable, concurrently and identically treated patients (who were eligible and would have been treated on protocol but for the lack of study opening) mobilized with G-CSF alone served as comparisons. CD34(+) cell yields were substantially higher with the first apheresis following rhTPO and G-CSF versus G-CSF alone: 4.1 x 10(6)/kg (range, 1.3 to 17.6) versus 0.8 x 10(6)/ kg (range, 0.3 to 4.2), P =.0003. The targeted minimum yield of 3 x 10(6) CD34(+) cells/kg was procured following a single apheresis procedure in 61% of the rhTPO and G-CSF-mobilized group versus 10% of G-CSF-mobilized patients (P =.001). In rhTPO and G-CSF mobilized patients, granulocyte (day 8 v 9, P =.0001) and platelet recovery (day 9 v 10, P =.07) were accelerated, and fewer erythrocyte (3 v 4, P =.02) and platelet (4 v 5, P =.02) transfusions were needed compared with G-CSF-mobilized patients. Peripheral blood platelet counts, following rhTPO and G-CSF, were increased by greater than 100% and the platelet content of PBPC products by 60% to 110% on the first and second days of aphereses (P <.0001) with the greatest effect seen with repeated dosing of rhTPO at 0.6 microgram/kg. rhTPO is safe and well tolerated as a mobilizing agent before PBPC collection. Mobilization with rhTPO and G-CSF, in comparison to a comparable, nonrandomized G-CSF-mobilized group of patients, decreases the number of apheresis procedures required, may accelerate hematopoietic recovery, and may reduce the number of transfusions required following high-dose chemotherapy for breast cancer.

High efficiency adenovirus-mediated gene transfer to human dendritic cells.

The interest in the use of human dendritic cells in cancer immunotherapy calls for efficient ex vivo methods of dendritic cell education. To extend the range of methods available, we generated phenotypically characteristic dendritic cells from peripheral blood monocytes incubated with granulocyte-macrophage colony-stimulating factor and interleukin-4 and infected them with an adenovirus containing a humanized version of green fluorescent protein as a marker of gene expression. The levels of expressed protein were high, but they were further increased in combination with cationic liposomes. In comparison to transfection efficiency of the homologous expression plasmid, adenovirus-mediated gene transfer was substantially more efficient. With the aid of liposome-mediated infection, gene transfer into CD83+ dendritic cells was highly effective, resulting in more than 90% of the cells expressing the transgene.

Nitrogen-15 NMR chemical shifts in oligopeptides coordinated to cobalt(III).

Dipeptide, tripeptide, and tetrapeptide complexes with cobalt(III) ions were studied as model compounds for evaluation of 15N NMR chemical shifts induced in proteins upon binding transition metal ions. Coordination of oligopeptides to cobalt(III) resulted in large negative 15N NMR shifts for amine nitrogens (-76 to -32 ppm) and deprotonated amide nitrogens (-47 to -10). Coordination-induced shifts were affected by the nature of moiety at the trans position; the shifts were always larger with a carboxylato oxygen than with an amine nitrogen in the trans position. Thus, coordination-induced 15N NMR shifts provided direct and specific information on the stereochemistry of peptide coordination. Two new complexes, [Co(Gly-gly-gly-glyH(-3))(NH3)2] and Ba[Co(Gly-L-hisH(-2))(NO2)3], were synthesized and their structure was determined by NMR spectroscopy.