Heteropentanuclear {Ru(II)Cu(II)4} Kuratowski Complexes Assembled from a Ruthenium(II) Precursor Complex to Study Competing Exchange Interactions in M(II)(ta)2 Networks [ta(-) = 1,2,3-Triazolate].

We report a directed two-step synthesis toward pentanuclear Kuratowski complexes. First, six 5,6-dimethylbenzo[1,2,3]triazole ligands (Me2btaH) are coordinated to a single Ru(II) ion, providing a topologically ideal template for the addition of further metal ions. The synthesis and crystal structures of [RuCu4X4(Me2bta)6] [X = acetylacetonate (acac) and tris(3,5-dimethyl-1-pyrazolyl)borate (Tp*)] are described. Both represent new members of the family of so-called Kuratowski (K3,3) complexes. The coordination units feature triazolato-bridged metal-centered {MM4} tetrahedra, which are known for frustrated magnetic interactions in both complexes and metal-organic frameworks. The novel Ru(II)-centered complexes were synthesized in order to investigate the influence of the presence or absence of a paramagnetic central metal ion in the Kuratowski complex. Superconducting quantum interference device and electron spin resonance measurements demonstrate that small deviations in bond lengths and valence angles can lead to the formation of pairs of magnetic exchange-coupled Cu(II) ions. Which Cu(II) ions pair up can be predicted in Jahn-Teller active compounds by the overlap of the respective orbitals. These data are compared with those gleaned for M(II)(ta)2 (ta = 1,2,3-triazolate) lattices, in which structurally similar {MM4} tetrahedra constitute the secondary building units.

Lanthanide Coordination Polymers and MOFs based on the Dicyanodihydridoborate Anion.

New lanthanide cyanoborates were synthesized from anhydrous lanthanide chlorides and the acid H[BH2 (CN)2 ] in either acetonitrile or pyridine. Reactions in acetonitrile lead to three-dimensional, anionic metal-organic frameworks (MOFs) 3 ∞ [Ln2 {BH2 (CN)2 }9 ]⋅[Ln(CH3 CN)9 ] (Ln=Ce, Eu, Tb) which incorporate complex cations [Ln(CH3 CN)9 ]3+ in the pores of the framework for charge compensation. In contrast, the reactions in pyridine result in the formation of one-dimensional coordination polymers 1 ∞ [H(py)2 ][LnCl2 {BH2 (CN)2 }2 (py)2 ]⋅0.5 py (Ln=Ce, Pr, py=pyridine) with [H(py)2 ]+ as counter ions for the anionic strand structure. The products show intense photoluminescence, for Ce3+ based on 5d-4f transitions in the blue spectral region, whereas the Eu3+ and Tb3+ compounds exhibit characteristic photoluminescence based on 4f-4f transitions of the respective lanthanide ions. The observed photoluminescence is mainly attributed to a direct excitation of the lanthanide ions and sensitization of the lanthanide ions by the [BH2 (CN)2 ]- anions. These results mark the utilized borate anions as versatile building block for new coordination compounds.

Effects of total parental nutrition (TPN) during high-dose interleukin-2 treatment for metastatic cancer.

Patients treated with high doses of interleukin-2 (IL-2) develop profound anorexia, malaise, loss of energy, mucositis, nausea, and vomiting, which may contribute to poor nutrition. We hypothesized that total parenteral nutrition (TPN) administration would ameliorate these changes and could improve fluid and electrolyte balance. A retrospective analysis of protein and energy intake was performed in 21 sequential patients who received a normal diet (controls) and 16 subsequent patients who received TPN during IL-2 treatment. The effect of TPN on laboratory abnormalities induced by IL-2 was also evaluated. Within 24 h of starting IL-2, mean energy intake declined to 2.5-2.8 kcal/kg in controls in contrast to the energy intake of 25-29 kcal/kg in patients receiving TPN. Protein nutrition was affected in a similar fashion, with a markedly lower protein intake in controls (0.08-0.12 g/kg) than in the TPN group (1.02-1.10 g/kg). TPN improved serum calcium and potassium concentrations, particularly during spontaneous diuresis after completion of IL-2 treatment. Unexpectedly, TPN decreased the frequency and severity of cholestatic jaundice caused by IL-2. Patients receiving TPN had an increased propensity for hyperglycemia and hypophosphatemia. High-dose intravenous bolus IL-2 therapy resulted in a markedly negative nutritional balance in control patients. A brief period of TPN during IL-2 treatment was well tolerated and corrected calorie and protein malnutrition. TPN administration also improved control of serum electrolytes. TPN did not adversely affect tumor progression or patient survival.

Age, genetic, and nongenetic factors influencing variation in serum sex steroids and zonal volumes of the prostate and benign prostatic hyperplasia in twins.

BACKGROUND: We have observed that hereditary and environmental factors have a substantial influence on the plasma content of sex steroids in normal male twins and in men of families with prostatic disease. METHODS: The contribution of genetic and nongenetic familial factors on the variation of plasma sex steroid concentrations and of the volume of zones of the prostate measured by transrectal ultrasound (TRUS) has now been investigated in pairs of male monozygotic (MZ) and dizygotic (DZ) twin pairs between age 25-75 years. Bioelectric impedance permitted quantitation of body fat, lean body mass, and water. Morphometrics and testicular volume were also determined. RESULTS: The intraclass correlation (rI) was > 0.40 for the variation of the total volume (TV), the transition zone (TZ), the peripheral zone (PZ), and the ratio of TZ/PZ in both MZ and DZ twins, and heredity affected 22% of the variation of the PZ and TZ and 30% of the ratio of TZ/PZ. None of the TV and environmental factors influenced the remainder of the variation. Heredity accounted for 25% or more of the variation of dihydrotestosterone (DHT), and the ratios of DHT/testosterone (T), estradiol (E2)/T, androstanediol glucuronide, sex hormone-binding globulin (SHBG)-bound T, T/SHBG, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and dehydroepiandrosterone sulfate (DHEA-S). In MZ twin pairs the variation of the volumes of the prostate became greater with age. In contrast, the variation of the sex hormone concentrations did not show greater variation with age. Heredity also affected > 30% of the variation for waist measurement, weight, body fat, body mass, water and lean body mass, body mass/fat, and testicular size. CONCLUSIONS: Our results indicated that both MZ and DZ twin pairs had zonal prostate volumes more like their twin pair than like unrelated twins. However, nongenetic factors exerted stronger influences than genetic factors on zonal volumes of the prostate. In contrast, hereditary factors had stronger influences on determining the variation of many sex hormones and morphometric characteristics than did nongenetic factors.

Randomized trial of immune-enhancing enteral nutrition in burn patients.

BACKGROUND: "Immune-enhancing" diets (IEDs) are aimed at improving outcomes in patients suffering trauma and infection. This study was conducted to evaluate a popular IED in patients suffering burn injury. METHODS: Fifty burned patients were randomized to receive either Impact (Sandoz Nutrition, Minneapolis, Minn), an IED enhanced with omega-3 fatty acids, arginine, and RNA, or Replete (Clintec, Deerfield, Ill), our standard high-protein diet. Feedings were begun within 48 hours of injury, and continued until patients supported themselves with oral intake. RESULTS: Forty-nine patients completed the study. The two feeding groups did not differ with respect to age, burn size, incidence of inhalation injury, or the quantity of calories and protein received. There were no differences between groups in mortality, length of hospitalization, hospital charges, days of ventilator support, or incidence of complications. Patients with inhalation injuries required more ventilatory support, and had longer lengths of hospitalization and higher costs. CONCLUSIONS: Administration of an IED has no clear advantages over the use of less expensive high-protein enteral nutrition in burn patients.

Evidence for sex steroid inhibition of lipoprotein lipase in men: comparison of abdominal and femoral adipose tissue.

Plasma estradiol has been suggested to suppress adipose tissue lipoprotein lipase (LPL) activity in women. The present study explores the regulation of LPL by sex steroids in sedentary obese men (N = 24) at their usual weight. Femoral adipose tissue LPL activity, eluted with serum and heparin or extracted with detergent, showed significant inverse correlations with plasma levels of testosterone, bioavailable testosterone, dihydrotestosterone, and estradiol. Both measures of femoral LPL activity were also correlated with the weight change occurring despite efforts to maintain a constant weight. Abdominal LPL activity showed significant but weaker inverse correlations with bioavailable testosterone only. Multivariate analysis of potential predictors for eluted femoral LPL activity showed that plasma testosterone, dihydrotestosterone, and estradiol were interdependent, whereas the rate of weight change was an independent variable. In the regression equation, only bioavailable testosterone and weight change were retained, explaining 63% of the variability (R = .79, P = .0002). These results suggest that sex steroids suppress adipose tissue LPL activity in men, and more so in the thigh than in the abdomen, thereby possibly contributing to a central fat accumulation. The data are compatible with a model from male animals suggesting that testosterone effects on adipose tissue LPL are mediated by estradiol formed locally.

Nitric oxide synthesis in patients with advanced HIV infection.

The discovery that humans produce nitric oxide and that this molecule plays an important role in cell communication, host resistance to infection, and perhaps in host defence to neoplastic disease, has created much interest in further research on its function in the body. A cytokine-inducible high output L-arginine/nitric oxide pathway was recently detected in patients with advanced malignancy treated with IL-2. The production of nitric oxide was thus examined in patients with advanced HIV infection and in intensive care unit control patients. Extrinsic nitrate and nitrite consumption were carefully controlled in the diet or through the use of total parenteral nutrition. Seven of eight HIV+ patients were placed into positive nitrogen balance. Nitric oxide synthesis was found to be within the normal human range. In contrast, nitric oxide synthesis in extremely ill intensive care unit patients was low normal to depressed.