PEG modified liposomes containing CRX-601 adjuvant in combination with methylglycol chitosan enhance the murine sublingual immune response to influenza vaccination.

The mucosa is the primary point of entry for pathogens making it an important vaccination site to produce a protective mucosal immune response. While the sublingual (SL) mucosa presents several barriers to vaccine penetration, its unique anatomy and physiology makes it one of the best options for mucosal vaccination. Efficient and directed delivery of adjuvants and antigens to appropriate immune mediators in the SL tissue will aid in development of effective SL vaccines against infectious diseases. Herein we demonstrate a robust immune response against influenza antigens co-delivered sublingually with engineered liposomes carrying the synthetic Toll-like receptor-4 agonist, CRX-601. Liposome modification with PEG copolymers (Pluronics), phospholipid-PEG conjugates and chitosan were evaluated for their ability to generate an immune response in a SL murine influenza vaccine model. Phospholipid-PEG conjugates were more effective than Pluronic copolymers in generating stable, surface neutral liposomes. SL vaccination with surface modified liposomes carrying CRX-601 adjuvant generated significant improvements in flu-specific responses compared with unmodified liposomes. Furthermore, the coating of modified liposomes with methylglycol chitosan produced the most effective flu-specific immune response. These results demonstrate efficient SL vaccine delivery utilizing a combination of a muco-adhesive and surface neutral liposomes to achieve a robust mucosal and systemic immune response.

Hemodynamic and metabolic effects of rapid correction of hypophosphatemia in patients with septic shock.

STUDY OBJECTIVE: To examine the hemodynamic and metabolic short-term effects of hypophosphatemia correction in patients with septic shock receiving catecholamine therapy. DESIGN: Prospective, single cohort study. SETTING: ICU, university hospital. PATIENTS: Ten patients with septic shock and hypophosphatemia below 2 mg/dL. INTERVENTIONS: Infusion of glucose-1-phosphate solution (20 mmol of elemental phosphorus) for 60 min. MEASUREMENTS AND RESULTS: Hemodynamic, oxygen-derived, acid-base, and electrolyte parameters before and immediately after phosphate infusion. Left ventricular stroke work index increased significantly (22%) from a mean low value of 24 +/- 10 g/m2 without changes in filling pressures. Systolic arterial pressure improved by 12%. Arterial pH improved slightly but significantly. Ionized calcium level slightly decreased within the normal range values. Other parameters remained unchanged. CONCLUSIONS: Severe hypophosphatemia may be considered as a superimposed cause of myocardial depression, inadequate peripheral vasodilatation, and acidosis in septic shock. A rapid correction of hypophosphatemia is well tolerated and may have both myocardial and vascular beneficial effects. The magnitude of the response, however, is variable and unpredictable on the basis of serum phosphorus levels.

Enteral supplementation of phosphate does not prevent hypophosphatemia during refeeding of cachectic patients.

Hypophosphatemia due to parenteral nutrition has been described frequently. It was attributed to the lack of phosphorus content in parenteral nutrition solutions. With modern parenteral nutrition regimens containing phosphorus, this problem has been virtually eliminated. Enteral nutrition solutions contain adequate phosphate for patients with normal phosphate stores. Hypophosphatemia has therefore rarely been reported in enteral nutrition. We describe two patients with protein-energy malnutrition who developed severe hypophosphatemia during tube feeding with phosphorus-containing formula diets. Chronic alcoholism and vitamin D deficiency due to malabsorption because of Crohn's disease were additional risk factors in these two patients. Patients with depleted phosphate stores and high metabolic demand have a higher daily requirement for phosphorus than is available in routine isotonic enteral formulas. This case report emphasizes the importance of monitoring serum phosphate concentration daily during the first week of refeeding.

Evaluation of 99Tcm-labelled alpha-D-glucose 1-phosphate aerosols for SPECT ventilation lung imaging.

The purpose of the present investigation was to evaluate 99Tcm-labelled alpha-D-glucose 1-phosphate (GP) aerosols for single photon emission computed tomographic (SPECT) ventilation lung imaging in comparison to 99Tcm-diethylenetriaminepentaacetate (DTPA) aerosols. Ten normal nonsmoking male volunteers (aged 20-30 years) were included in this study after obtaining their informed consent. 99Tcm-GP, 30 mCi, in 2 ml was placed in the nebulizer (Venticis II) and inhalation continued for 5 min of normal breathing with oxygen flowing through. In 10 subjects dynamic images were obtained from the posterior position for 90 min with 45 frames on a 64 x 64 matrix by the use of a gamma camera. At the end of the dynamic study planar images of the lung (anterior, posterior and laterals) were recorded. Decay corrected clearance curves and kep values were obtained by the pulmonary epithelial programme and T1/2 values were calculated. The same procedure was followed by the use of 99Tcm-DTPA in the same subjects 2 weeks later. SPECT studies of the lung were performed in five subjects after inhalation of 99Tcm-GP aerosols. Clearance curves were monoexponential. The difference in T1/2 values between the right and left lungs was statistically insignificant (P > 0.10). The mean T1/2 values were 316.5 +/- 44.7 and 80.8 +/- 13.4 min for 99Tcm-GP and 99Tcm-DTPA, respectively. The difference was significant (P < 0.0005). On scintigraphic images 99Tcm-GP showed high alveolar deposition and low adhesion to major airways like 99Tcm-DTPA. However, it is preferred to 99Tcm-DTPA for SPECT studies because of its prolonged pulmonary clearance.

Glycero- vs glucose-phosphate in parenteral nutrition of premature infants: a comparative in vitro evaluation of calcium/phosphorus compatibility.

In total parenteral nutrition (TPN) of premature infants, glycero- and glucose-phosphate have been recommended, and clinically used, because of their considerable compatibility with calcium. However, a systematic comparative in vitro assessment of the therapeutic potential and safety of these substances has not yet been provided. We investigated the stability of TPN solutions containing calcium-gluconate and glycero- or glucose-phosphate in high concentrations. Evaluation was performed by visual inspection, absorptiometry, light microscopy, measurement of pH, and determination of calcium concentration before and after microfiltration. Even under circumstances promoting precipitation of calcium and phosphate--such as body temperature, relatively high pH, and concentrations of calcium and phosphorus exceeding those necessary to provide intrauterine accretion rates, all but one of the examined TPN admixtures remained stable. Our data suggest that the use of glycero-phosphate, and particularly glucose-phosphate, together with calcium-gluconate, is an uncomplicated and safe procedure to administer simultaneously high amounts of calcium and phosphorus in TPN of premature infants.

[The role of glucose-1-phosphate in total parenteral nutrition protocols]. / Aporte de glucosa-1-fosfato en nutrición parenteral total protocolizada.

The results of a clinical study to evaluate the use of glucose-1-phosphate for phosphate supplementation to a group of 8 surgical patients receiving standardized total parenteral nutrition are presented. Average phosphate (p + 0.001), calcium (NS) and magnesium (NS) plasma concentrations increased during total parenteral nutrition. Positive average daily balances were obtained: 8.1 + 14.8, 4.5 + 4.3 and 1.8 + 3.3 mmol/day for phosphate, calcium and magnesium respectively. These findings support the hypothesis of higher bioavailability of glucose-1-phosphate with respect to inorganic phosphate. On the other hand, hyperphosphatemia was a frequent situation (45.8%); this fact suggests the need for reviewing phosphate daily requirements when supplied in the form of glucose-1-phosphate.

[The effect of osteopenia prevention in very small premature infants on hormonal parameters of calcium metabolism and bone mineralization]. / Der Einfluss der Osteopenie-Prophylaxe bei sehr kleinen Frühgeborenen auf die hormonellen Parameter des Calciumstoffwechsels sowie die Skelettmineralisation.

In 23 very low birth weight infants the influence of mineral supplementation with 0.4 mmol calciumgluconate and 0.2 mmol glucose-1-phosphate/dl human milk on concentrations of 25-OH-D3, parathyroid hormone, calcitonine, calcium, phosphorus and activity of alkaline phosphatase was studied on days 3, 8, 28 and 56. On days 28 and 56 respectively, degree of bone mineralisation was classified. 8 preterm infants received supplementation before day 28, 7 infants after day 28, 8 infants had no supplementation. All preterm infants received beginning with day 7 vitamin D3 1000 IU/day. In all preterms mean concentrations of 25-OH-D3 were normal and increasing with age. Concentrations of parathyroid hormone and calcitonine were first of all increased and decreased with age, especially in supplemented infants. Light metabolic bone disease without fractures occurred in 4 infants of supplemented groups. Non-supplemented group contains 5 infants with severe metabolic bone disease without fractures. Results indicate intact metabolism and secretion of 25-OH-D3, parathyroid hormone and calcitonine. Decrease of calcitonine concentration in mineral supplemented preterms is a reference to a better mineral supply. Mineral supplementation is followed by an increase in bone mineralisation with prevention of severe metabolic bone disease.

Doseamento da atividade da glicose-6-fosfato desidrogenase em células in vitro / Evaluation of glucose-6-phosphate dehydrogenase activity in cells in vitro

A atividade de glicose-6-fosfato desidrogenase em células in vitro foi determinada através de método espectrofotométrico. Foi estabelecida a densidade populacional adequada e padronizaram-se as condiçöes para extraçäo da enzima e para o desenvolvimento da reaçäo

Metabolic fluxes between [14C]2-deoxy-D-glucose and [14C]2-deoxy-D-glucose-6-phosphate in brain in vivo.

The rates of the phosphorylation and dephosphorylation of 2-deoxyglucose were measured in rat brain in vivo using tracer kinetic techniques. The rate constant for each reaction was estimated from two separate experiments with different protocols for tracer administration. Tracer amounts of [1-14C]2-deoxyglucose (1 microCi) were injected through the internal carotid artery (intraarterial experiment), or through the atrium (intravenous experiment). Brains were sampled by freeze-blowing at various times after the injection. In the intraarterial experiment, the rate constant for the forward reaction from 2-deoxyglucose to 2-deoxyglucose phosphate was calculated by dividing the initial rate of 2-deoxyglucose phosphate production by the 2-deoxyglucose content in brain. The rate constant for the reverse reaction from 2-deoxyglucose phosphate to 2-deoxyglucose was calculated from the decay constant of 2-deoxyglucose phosphate. The rate constants estimated were 10.1 +/- 1.4%/min (SD) and 3.00 +/- 0.01%/min (SD), respectively, for the forward and reverse reactions. In the intravenous experiment, rate constants for both reactions were estimated by compartmental analysis. By fitting data to program SAAM-27, the rate constants for the forward and reverse reactions were estimated as 11.4 +/- 0.4%/min (SD) and 5.1 +/- 0.4%/min (SD), respectively. The rate constants determined were compared to those for the reactions between glucose and glucose-6-phosphate, estimated previously from labeled glucoses. It is concluded that the rate of glucose utilization measured by the 2-deoxyglucose method reflects the rate of the hexokinase reaction and not the rate of glucose utilization or brain energy utilization.

Cyclophosphamide-induced oncogenic transformation, chromosomal breakage, and sister chromatid exchange following microsomal activation.

Cyclophosphamide, an extensively used cancer chemotherapeutic agent, requires metabolic activation through a mixed-function oxygenase system. The capacity of this agent to produce oncogenic transformation and chromosomal damage, including increases in sister chromatid exchanges, was investigated in cell culture with or without an exogenous liver metabolic activation system. No oncogenic transformation or chromosomal aberrations were produced by cyclophosphamide in the absence of metabolic activation, whereas significant transformation, chromosomal breaks, and increases in sister chromatid exchanges were observed when the activation system was incorporated into the assays. The oncogenic transformation and chromosomal changes were completely eliminated by removing glucose 6-phosphate and nicotinamide adenine dinucleotide phosphate from the metabolic generating system. These studies emphasize the necessity to incorporate some activation procedure into short-term assays used for evaluating the mutagenic and/or oncogenic potential of various chemicals.