Immunotherapeutic effects of chitin in comparison with chitosan against Leishmania major infection

Chitin and chitosan microparticles (MPs) are important immune system stimulators. The aim of this study was to evaluate the protective effects of these compounds in comparison with each other against Leishmania infection in BALB/c mice infected with Leishmania major (L. major).Female BALB/c mice were injected subcutaneously with 2 × 10⁵ promastigotes. Chitin and/or chitosan MPs (< 40 μm) were subcutaneously injected in the BALB/c mice with two-day intervals until two weeks. Mice in all groups were sacrificed at 12 weeks post-infection. Enumeration of viable parasites was performed using limiting dilution assay. Furthermore, the animals (5 mice/group) were sacrificed two weeks post-infection. The lymph node cells were isolated and the effects of the chitinous MPs on the proliferation and production of cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) were determined. The mean sizes of lesions were significantly smaller in chitin (0.6 ± 0.12 mm) and chitosan treated groups (1.2 ± 0.8 mm) than in the control group (6.2 ± 1.7 mm) (P < 0.05). The parasite load in the lymph nodes of the treated mice was significantly lower than that in the lymph nodes of controls (1.31 × 10⁶ vs 8.24 × 10⁷ parasite/lymph node [P = 0.032] and 7.49 × 10⁶ vs 8.24 × 10⁷ parasite/lymph node [P = 0.05] for chitin and chitosan MPs treatment, respectively). We found that chitinous MPs induced cell proliferation and that chitin but not chitosan increased TNF-α and IL-10 production. Chitin appears that it has more effect than chitosan against leishmaniasis. The current study revealed that chitinous MPs had significant activity against L. major and could be considered as new therapeutic modality in leishmaniasis.     

Bioconversion of phenylpyruvic acid to l-phenylalanine by mixed-gel immobilization of Escherichia coli EP8-10

A mixed-gel of κ-carrageenan and gelatin was used in l-phenylalanine production. The mixed-gel, containing 87.5% κ-carrageenan and 12.5% gelatin [the total gel concentration was 4 wt%], showed the best performance and was selected for further study with Escherichia coli EP8-10. The optimum pH and temperature were 8.5 and 37 °C, respectively. The effects of trehalose and Mg²⁺ were studied in the mixed-gel immobilization. Their optimum concentrations were 5 × 10^?2 and 2 × 10^?3 mol/L, respectively. Under the optimal conditions, 98.3% of the phenylpyruvic acid (PPA) was converted to l-phenylalanine. The activity recovery of the transaminase enzyme in the mixed-gel immobilization was higher than that in single κ-carrageenan immobilization, which was 93.6%. The total PPA conversion rate was over 80% in all 15 batches, suggesting great sustainability in the mixed-gel immobilization. The maximum reaction rate (r_max) was calculated to be 4.75 × 10^?2 mol/(L g h).     

Magnetic properties of six-coordinated high-spin cobalt(II) complexes: Theoretical background and its application

In this contribution we study and analyse the influence of the different parameters involved in the magnetic susceptibility of six-coordinated high-spin Co(II) complexes. We propose an empirical expression to fit the magnetic susceptibility of polycrystalline samples of mononuclear Co(II) complexes with an axial distortion, the variable parameters being Δ (axial distortion), α (orbital reduction factor) and λ (spin–orbit coupling). This expression avoids solving the 12 × 12 matrix associated to the distortion of the ⁴T_1g term. In order to take into account the magnetic coupling (J) in the polynuclear Co(II) complexes, a perturbational approach is proposed to describe their magnetic susceptibility in the whole temperature range (2–300 K) as a function of J, Δ, α and λ. This approach is valid in the limit of the weak magnetic coupling as compared to the spin–orbit coupling, |J/λ| < 0.1. The model allows the treatment of each cobalt(II) ion in axial symmetry as an effective spin S_eff = 1/2. That causes a drastic reduction of the matrix size of the polynuclear compounds from 12ⁿ × 12ⁿ to 2ⁿ × 2ⁿ, n being the number of Co(II) ions in the complex. The main advantage of the model is to make possible the fit of the magnetic susceptibility data of those polynuclear Co(II) complexes whose high nuclearity involved intractable matrices.     

Characterization of lactase-conjugated magnetic nanoparticles

Conjugation of lactase to magnetic nanoparticles is of interest in biosensor and ingredient processing applications that require high enzyme concentration and catalyst separation from the reaction stream. However, little is known about the effects of these materials on the physicochemical attributes of conjugated lactase. Lactase (Aspergillus oryzae) was covalently attached by carbodiimide chemistry to carboxylic-acid functionalized magnetic particles having a hydrodynamic radius of 18 nm. The resulting enzyme–nanoparticle conjugates were characterized with regard to particle size, zeta potential, enzyme kinetics, temperature and pH stability, catalyst recovery, and secondary structure changes. Following attachment, the materials retained colloidal stability and individual particle characteristics with a zeta potential of ?33 mV compared to ?46 mV for the native particle. The conjugated enzyme showed no changes in secondary structure and exhibited significant catalytic activity with a catalytic efficiency of 2.8 × 10³ M^?1 s^?1 compared to 2.5 × 10³ M^?1 s^?1 for the native enzyme. Relative to the free enzyme, the conjugated enzyme was recovered for repeated use with 78% activity retained after five cycles. This work demonstrates that carboxylic-acid functionalized magnetic nanoparticles can be utilized as a means of producing a simple and effective conjugated-lactase system that achieves both particle and enzyme stability.     

The influence of light quality on akinete formation and germination in the toxic cyanobacterium Anabaena circinalis

Physiological control of akinete formation and subsequent germination is likely to be important in understanding and predicting how natural populations of cyanobacteria respond to their environment. While previous research has indicated nutrient limitation may be important in akinete formation new results presented here indicate that in the toxic and bloom-forming species Anabaena circinalis there was a profound effect of spectral quality. Under 40 μmol photons m^?2 s^?1 photosynthetically active irradiance (PAR) of predominately red irradiance akinete production was maximal at 2.1 × 10^?4 akinetes vegetative cell^?1 d^?1, some 3000 times greater than the 6.5 × 10^?8 akinetes vegetative cell^?1 d^?1 observed under equivalent PAR but predominately blue light. For cells grown under a range of predominantly red, white and green irradiance even short exposures to blue light reduced akinete formation rates by a factor of ten relative to controls, indicating that exposure to blue light inhibits akinete formation. Germination of akinetes was not influenced by the irradiance under which akinetes were formed: 88 ± 4.1% (mean ± 1 S.D.) of akinetes germinated with no evidence of an effect on germination success due to their production under predominately red, white or green irradiance (germination of akinetes produced under blue light was not tested). Spectral quality had a significant impact on both vegetative cell and germling growth rates. The results indicate a significant reduction in the cellular differentiation of A. circinalis vegetative cells into akinetes that is mediated by blue light. In an ecological context the production of akinetes will be greater in environments with less blue light; potentially including those with slower flow, more stratification, less vertical mixing and more turbidity. The resulting spatial pattern of akinete production is likely to influence the location of akinetes in sediments and the development of subsequent blooms from excysting germlings.     

Specific activity and viability of Nitrosomonas europaea during discontinuous and continuous fermentation

The energy conservation and number of viable cells of Nitrosomonas europaea fluctuate dramatically during cultivation. In discontinuous culture the specific activity (SA) reaches its maximum after 9 h with about 2700 nmol O₂ (mg protein)^?1 min^?1, where the highest number of viable N. europaea cells is detectable after 21 h with 2 × 10⁸ cell ml^?1. Afterwards, both SA and viable cell number immediately start to decrease. Accordingly, the exponential growth turns into a linear growth, whereby the number of viable cells permanently decreases. The exponential growth phase can be extended from about 21 to 38 h by increasing the concentration of CO₂ or trace elements. In continuous fermentation of N. europaea, SA of about 2500 nmol O₂ (mg protein)^?1 min^?1 and viable cell number of 2.5 × 10⁸ cell ml^?1 is detectable at dilution rates between 1 and 1.8 day^?1. At dilution rates below 1 day^?1, SA and number of viable cells are reduced. The minimal doubling time is 13 and 15 h during continuous and discontinuous fermentation, respectively. Consequently, cell production of N. europaea should be performed in continuous fermentation. When bacteria are grown in discontinuous systems, they should be harvested in the early exponential growth phase.     

Biodegradation of Tapis blended crude oil in marine sediment by a consortium of symbiotic bacteria

Biodegradation rate and the high molecular weight hydrocarbons are among the important concerns for bioremediation of crude oil. Inoculation of a non-oil-degrading bacterium as supplementary bacteria increased oil biodegradation from 57.1% to 63.0% after 10 days of incubation. Both the oil-degrading bacteria and the non-oil-degrading bacteria were isolated from Malaysian marine environment. Based on the 16S rDNA sequences, the oil-degrading bacteria was identified as Pseudomonas pseudoalcaligenes (99% similarity) while the non-oil-degrading bacterium was Erythrobacter citreus (99% similarity). E. citreus does not grow on crude oil enriched medium under present experimental condition but it withstands 5000 mg kg^?1 Tapis blended crude oil in sediment. Under optimal condition, the oil-degrading bacterium; P. pseudoalcaligenes, alone utilized 583.3 ± 3.8 mg kg^?1 (57.1%) at the rate of 3.97 × 10^?10 mg kg^?1 cell^?1 day^?1 Tapis blended crude oil from 1000 mg kg^?1 oil-contaminated sediment. Inoculation of E. citreus as the supplementary bacteria to P. pseudoalcaligenes enhanced biodegradation. The bacterial consortium degraded 675.8 ± 18.5 mg kg^?1 (63.0%) Tapis blended crude oil from the 1000 mg kg^?1 oil-contaminated sediment. Biodegradation rate of the bacterial consortium increased significantly to 4.59 × 10^?10 mg kg^?1 cell^?1 day^?1 (p = 0.02). Improvement of the oil degradation by the bacterial consortium was due to the synergetic reaction among the bacterial inoculants. There are two implications: (1) E. citreus may have a role in removing self-growth-inhibiting compounds of P. pseudoalcaligens. (2) P. pseudoalcaligenes degraded Tapis blended crude oil while E. citreus competes for the partially degraded hydrocarbons by P. pseudoalcaligenes. P. pseudoalcaligenes forced to breakdown more hydrocarbons to sustain its metabolic requirement. The bacterial consortium degraded 78.7% of (C₁₂–C₃₄) total aliphatic hydrocarbons (TAHs) and 74.1% of the 16 USEPA prioritized polycyclic aromatic hydrocarbons.     

A stable immobilized d-psicose 3-epimerase for the production of d-psicose in the presence of borate

Maximal activity of the immobilized d-psicose 3-epimerase from Agrobacterium tumefaciens on Duolite A568 beads was achieved at pH 9.0 and 55 °C with borate, and at pH 8.5 and 50 °C without borate. The half-lives of the immobilized enzyme at 50 °C with and without borate were increased 4.2- and 128-fold compared to that of the free enzyme without borate, respectively. The immobilized enzyme with borate produced 441 g l^?1 psicose from 700 g l^?1 fructose at pH 9.0 and 55 °C, whereas 193 g l^?1 psicose was produced without borate at pH 8.5 and 50 °C after 120 min in a batch reaction. The immobilized enzyme in a packed-bed bioreactor without borate was produced continuously 325 g l^?1 psicose from 500 g l^?1 fructose at a dilution rate of 1.62 h^?1 over a 236 h period with productivity of 527 g l^?1 h^?1 while that without borate produced 146 g l^?1 psicose at 4.15 h^?1 over a 384-h period with productivity of 606 g l^?1 h^?1. The operational half-lives of the enzyme with and without borate in the bioreactor were 601 and 645 h, respectively. In the present study, psicose was produced stably with high productivity using the immobilized d-psicose 3-epimerase in the presence of borate.     

Inulin hydrolysis and citric acid production from inulin using the surface-engineered Yarrowia lipolytica displaying inulinase

The INU1 gene encoding exo-inulinase cloned from Kluyveromyces marxianus CBS 6556 was ligated into the surface display plasmid and expressed in the cells of the marine-derived yeast Yarrowia lipolytica which can produce citric acid. The expressed inulinase was immobilized on the yeast cells. The activity of the immobilized inulinase with 6 × His tag was found to be 22.6 U mg^?1 of cell dry weight after cell growth for 96 h. The optimal pH and temperature of the displayed inulinase were 4.5 and 50 °C, respectively and the inulinase was stable in the pH range of 3–8 and in the temperature range of 0–50 °C. During the inulin hydrolysis, the optimal inulin concentration was 12.0% and the optimal amount of added inulinase was 181.6 U g^?1 of inulin. Under such conditions, over 77.9% of inulin was hydrolyzed within 10 h and the hydrolysate contained main monosaccharides and disaccharides, and minor trisaccharides. During the citric acid production in the flask level, the recombinant yeast could produce 77.9 g L^?1 citric acid and 5.3 g L^?1 iso-citric acid from inulin while 68.9 g L^?1 of citric acid and 4.1 g L^?1 iso-citric acid in the fermented medium were attained within 312 h of the 2-L fermentation, respectively.     

Fructanolytic and saccharolytic enzymes of Treponema zioleckii strain kT

Enzymes in the newly described rumen bacterium, Treponema zioleckii strain kT, capable of digesting Timothy grass fructan, inulin, and sucrose were identified and characterized. Two specific endolevanases and one non-specific β-fructofuranosidase were found in a cell-free extract. The molecular weight of the endolevanases were estimated to be 60 and 36 kDa, whereas that of β-fructofuranosidase, 87 kDa. The former of the specific enzymes was associated with the outer membrane, while the latter and the non-specific β-fructofuranosidase, with the periplasm or cytosol. The K_m and V_max for Timothy grass fructan degradation by endolevanase were 0.27% and 15.75 μM fructose equivalents × mg protein^?1 × min^?1, those for sucrose and inulin digestion by β-fructofuranosidase were 1.35 × 10^?3 M and 1.73 μM hexoses × mg protein^?1 × min^?1 and 1.77% and 1.83 μM hexoses × mg protein^?1 × min^?1, respectively.     

Increased whole blood manganese concentrations observed in children with iron deficiency anaemia

A prospective observational study was carried out at Alder Hey Children's Hospital, Liverpool, England, UK on children aged 1–6 years attending the pathology department for routine blood tests (n = 225). Whole blood manganese concentrations were measured plus the following markers of iron status; haemoglobin, MCV, MCH, RBC count, ferritin, transferrin saturation and soluble transferrin receptors. Multiple regression analysis was performed, with blood manganese as the dependent variable and factors of iron status, age and gender as independent variables. A strong relationship between blood manganese and iron deficiency was demonstrated (adjusted R² = 34.3%, p < 0.001) and the primary contributing factors to this relationship were haematological indices and soluble transferrin receptors. Subjects were categorised according to iron status using serum ferritin, transferrin saturation and haemoglobin indices. Children with iron deficiency anaemia had higher median blood manganese concentrations (16.4 μg/L, range 11.7–42.4, n = 20) than children with iron sufficiency (11 μg/L, range 5.9–20.9, n = 59, p < 0.001). This suggests that children with iron deficiency anaemia may be at risk from manganese toxicity (whole blood manganese >20 μg/L), and that this may lead to neurological problems. Treatment of iron deficiency in children is important both to improve iron status and to reduce the risk of manganese toxicity.     

Iron containing keratinolytic metallo-protease produced by Chryseobacterium gleum

Chryseobacterium gleum exhibited complete dissolution of whole chicken-feathers (10 g l^?1, pH 8) after 72 h at 30 °C through synthesis of keratinolytic protease when inoculated at 1% (v/v). This enzyme was purified to 67-fold with yield of 2.25% having a specific activity of 1670 U mg^?1 and ～36 kDa Mw. MALDI-TOF MS of this keratinase showed some similarity with the keratinase peptides of Bacillus subtilis (BOFXJ2). The keratinase action was inhibited by EDTA, iodoacetamide and metal ions like mercury, copper and zinc (1 mM each), while it was enhanced by iron and calcium. Keratinase showed presence of 3 mM of Fe M^?1 as tested by atomic absorption spectroscopy and addition of Fe in its apoenzyme retained about 79% of original residual feather degradation activity which portrayed it to be metalloprotease. Purified keratinase revealed significant degradation (85%) of feather concentrate (20 g l^?1) to 3.9 μM ml^?1 of free amino groups in 24 h at an initial pH of 8.0, 30 °C and 120 rpm shaking. This keratinase activity can be controlled precisely by presence of chemical or metal ions which could be of use in biotechnology industry while the culture can be used in poultry waste management.     

High-rate denitrifying sulfide removal process in expanded granular sludge bed reactor

An expanded granular sludge bed (EGSB) reactor was adopted to incubate bio-granules that could simultaneously convert 4.8 kg-S m^?3 d^?1 of sulfide in 97% efficiency; 2.6 kg-N m^?3 d^?1 of nitrate in 92% efficiency; and 2.7 kg-C m^?3 d^?1 acetate in 95% efficiency. Mass balance calculation of sulfur, nitrogen, and carbon over the EGSB reactor confirmed the performance results. This noted reactor performance is much higher than those reported in literature. Stoichiometric relation suggests that the nitrate was reduced to nitrite via autotrophic denitrification pathway, then the formed nitrite was converted via heterotrophic denitrification pathway to N₂.     

Zoledronate-activated Vγ9γδ T cell-based immunotherapy is feasible and restores the impairment of γδ T cells in patients with solid tumors

Gamma/delta (γδ) T cells play a role in innate immunity and exhibit cytotoxicity toward a large range of tumor types. Recent studies have shown that aminobisphosphonates may be applied to a culture in which a large number of γδ T cells are proliferated ex vivo. We carried out a clinical study of 25 patients with various solid tumors to determine further the safety, immunologic effect and feasibility of zoledronate-activated Vγ9γδ T cell-based immunotherapy. No severe toxicity was observed. In the cells used for the first treatment, the total cell number, frequency and number of CD3⁺ Vγ9⁺ γδ T cells were 409 ± 284 × 10⁷ cells, 56 ± 33% and 255 ± 242 × 10⁷ cells, respectively. Aminobisphosphonate therapy or chemotherapy resulted in the suppression of CD3⁺ Vγ9⁺ γδ T-cell proliferation. The numbers of CD3⁺ T cells, CD3⁺ Vγ9⁺ γδ T cells and CD27^? CD45RA^? Vγ9⁺ subsets in peripheral blood were significantly lower in patients than in healthy subjects (P <y 0.05). From such an impaired immunologic condition, the numbers and frequencies of CD3⁺ Vγ9⁺ γδ T cells and CD27^? CD45RA^? subsets significantly increased in patients treated with this immunotherapy. Zoledronate-activated Vγ9γδ T cell-based immunotherapy that restores the number of Vγ9γδ T cells in cancer patients may provide another mode of adoptive immunotherapy.     

Knee flexor strength and bicep femoris electromyographical activity is lower in previously strained hamstrings

The aim of this study was to determine if athletes with a history of hamstring strain injury display lower levels of surface EMG (sEMG) activity and median power frequency in the previously injured hamstring muscle during maximal voluntary contractions. Recreational athletes were recruited, 13 with a history of unilateral hamstring strain injury and 15 without prior injury. All athletes undertook isokinetic dynamometry testing of the knee flexors and sEMG assessment of the biceps femoris long head (BF) and medial hamstrings (MHs) during concentric and eccentric contractions at ±180 and ±60° s^?1. The knee flexors on the previously injured limb were weaker at all contraction speeds compared to the uninjured limb (+180° s^?1 p = 0.0036; +60° s^?1 p = 0.0013; ?60° s^?1 p = 0.0007; ?180° s^?1 p = 0.0007) whilst sEMG activity was only lower in the BF during eccentric contractions (?60° s^?1 p = 0.0025; ?180° s^?1 p = 0.0003). There were no between limb differences in MH sEMG activity or median power frequency from either BF or MH in the injured group. The uninjured group showed no between limb differences in any of the tested variables. Secondary analysis comparing the between limb difference in the injured and the uninjured groups, confirmed that previously injured hamstrings were mostly weaker (+180° s^?1 p = 0.2208; +60° s^?1 p = 0.0379; ?60° ^?1 p = 0.0312; ?180° s^?1 p = 0.0110) and that deficits in sEMG were confined to the BF during eccentric contractions (?60° s^?1 p = 0.0542; ?180° s^?1 p = 0.0473). Previously injured hamstrings were weaker and BF sEMG activity was lower than the contralateral uninjured hamstring. This has implications for hamstring strain injury prevention and rehabilitation which should consider altered neural function following hamstring strain injury.     

Structure and magnetic properties of a trinuclear nickel(II) complex with benzenetricarboxylate bridge

Novel trinuclear Ni(II) complex [Ni₃(pmdien)₃(btc)(H₂O)₃](ClO₄)₃ · 4H₂O, 1 where pmdien = N,N,N′,N′,N″-pentamethyldiethylenetriamine, H₃btc = 1,3,5-benzenetricarboxylic (trimesic) acid, has been prepared and structurally characterized. Three nickel atoms are bridged by btc trianion and their coordination sphere is completed by three N atoms of pmdien and O atom of the water molecule. The three nickel(II) magnetic centers are equivalent and their coordination spheres are completed to deformed octahedrons. Magnetic susceptibility was measured over the temperature range 1.8–300 K and zJ′ = ?0.19 cm^?1, D = 3.79 cm^?1, g = 2.18 parameters were calculated.     

Removal of iron,arsenic and coliform bacteria from water by novel constructed soil filter system

The present paper presents results of the study in removal of iron, arsenic and total coliform from drinking water using single-pass constructed soil filter (CSF). Results indicated that arsenic levels ranged from 0.5 to less than 10 μg l^?1 levels; iron from 5 to less than 0.3 mg l^?1 and coliform from 10^?5 to less than 5 CFU/100 ml. The results revealed very high removal efficiency, i.e., over 99% and water quality as per WHO standard.     

Subcellular fractionation of Cu exposed oysters,Crassostrea virginica,and Cu accumulation from a biologically incorporated Cu rich oyster diet in Fundulus heteroclitus in fresh and sea water

In order to examine the effect of salinity on Cu accumulation from a naturally incorporated diet, oysters (Crassostrea virginica) were exposed in sea water for 96 days to four waterborne [Cu]: 2.9 ± 0.7 (control), 4.3 ± 0.6, 5.4 ± 0.5, and 10.7 ± 1.0 µg L^? 1. After 96 days, the control whole body [Cu] increased from 2.1 ± 0.5 to 9.1 ± 1.1 µg g^? 1 w.w. and the highest [Cu] was 163.4 ± 27.1 µg g^? 1 w.w. in the oysters. Despite large differences in tissue [Cu], there was no effect on the fraction of trophically available metal in the oyster suggesting that trophic transfer will correlate well with tissue [Cu]. The control and highest [Cu] oysters became diet for killifish (Fundulus heteroclitus) in fresh and seawater for 40 days. The two diets contained 84.7 ± 5.1 and 850.5 ± 8.8 µg Cu g^? 1 d.w. Fish were fed a combined diet of oyster and a pellet supplement (20.5 ± 1.0 µg Cu g^? 1 d.w.) both at 5% body mass day^? 1. In killifish, Cu increased ~ 7% in gills and 100% in intestines after 6 weeks of exposure to the high Cu diet. No other tissues accumulated Cu above control levels. An 11-fold difference free Cu²⁺ concentrations was predicted in intestinal fluid between fresh and sea water, but there was no corresponding effect of salinity on intestinal Cu accumulation suggesting that Cu is not accumulated as the free ion.     

The inhibitory effect of curcumin on voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells

We investigated the effects of curcumin, the principal active compound of turmeric, on voltage-dependent K⁺ (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells using the voltage-clamp technique. Curcumin reduced the Kv current in a dose-dependent manner with an apparent K_d value of 1.07 ± 0.03 μM. Although curcumin did not alter the kinetics of Kv current activation, it predominantly accelerated the decay rate of channel inactivation. The association and dissociation rate constants of curcumin were 1.35 ± 0.05 μM^?1 s^?1 and 1.47 ± 0.17 s^?1, respectively. Curcumin did not alter the steady-state activation or inactivation curves. Application of train pulses (1 or 2 Hz) increased curcumin-induced blockade of the Kv current, and the recovery time constant also increased in the presence of curcumin suggesting, that the inhibitory action of Kv currents by curcumin was use-dependent. From these results, we concluded that curcumin inhibited vascular Kv current in a state-, time-, and use-dependent manner.     

A first-principles bottom-up study of the magnetic interaction mechanism in the bulk ferromagnet p-O2N-C6F4-CNSSN

The crystals of the p-nitro perfluorophenyl dithiadiazolyl radical have been shown to present bulk ferromagnetism below 1.32 K. Using our first-principles bottom-up methodology, the mechanism of the magnetic interactions in these crystals has been studied to gain a rigorous quantitative understanding of such bulk ferromagnetism. The p-O₂N-C₆F₄-CNSSN crystal is found to present only two non-negligible interactions (J(d1) = 0.83 cm^?1 and J(d3) = 0.07 cm^?1). The dominant interaction J(d1) generates a three-dimensional (3D) magnetic topology that can be described as a distorted diamond-like arrangement. Using the appropriate minimal magnetic model to describe this topology, the magnetic susceptibility and heat capacity curves were computed. A good agreement is found between the computed and experimental magnetic susceptibility data. Furthermore, the critical temperature obtained from the heat capacity curve (0.6 K) agrees well with the experimental one. A comparison of the magnetic data for p-O₂N-C₆F₄-CNSSN and four nitronyl nitroxide bulk ferromagnets indicates that the critical temperature not only depends on the size of the largest J interactions, but also on the corresponding magnetic topology.