Use of quantum dots in aqueous solution to detect blood fingermarks on non-porous surfaces.

A new and original reagent based on the use of highly fluorescent cadmium telluride (CdTe) quantum dots (QDs) in aqueous solution is proposed to detect weak fingermarks in blood on non-porous surfaces. To assess the efficiency of this approach, comparisons were performed with one of the most efficient blood reagents on non-porous surfaces, Acid Yellow 7 (AY7). To this end, four non-porous surfaces were studied, i.e. glass, transparent polypropylene, black polyethylene, and aluminium foil. To evaluate the sensitivity of both reagents, sets of depleted fingermarks were prepared, using the same finger, initially soaked with blood, which was then successively applied on the same surface without recharging it with blood or latent secretions. The successive marks were then cut in halves and the halves treated separately with each reagent. The results showed that QDs were equally efficient to AY7 on glass, polyethylene and polypropylene surfaces, and were superior to AY7 on aluminium. The use of QDs in new, sensitive and highly efficient latent and blood mark detection techniques appears highly promising. Health and safety issues related to the use of cadmium are also discussed. It is suggested that applying QDs in aqueous solution (and not as a dry dusting powder) considerably lowers the toxicity risks.

An iterative Multiscale Finite-Volume algorithm converging to the exact solution

The multiscale finite volume (MsFV) method has been developed to efficiently solve large heterogeneous problems (elliptic or parabolic); it is usually employed for pressure equations and delivers conservative flux fields to be used in transport problems. The method essentially relies on the hypothesis that the (fine-scale) problem can be reasonably described by a set of local solutions coupled by a conservative global (coarse-scale) problem. In most cases, the boundary conditions assigned for the local problems are satisfactory and the approximate conservative fluxes provided by the method are accurate. In numerically challenging cases, however, a more accurate localization is required to obtain a good approximation of the fine-scale solution. In this paper we develop a procedure to iteratively improve the boundary conditions of the local problems. The algorithm relies on the data structure of the MsFV method and employs a Krylov-subspace projection method to obtain an unconditionally stable scheme and accelerate convergence. Two variants are considered: in the first, only the MsFV operator is used; in the second, the MsFV operator is combined in a two-step method with an operator derived from the problem solved to construct the conservative flux field. The resulting iterative MsFV algorithms allow arbitrary reduction of the solution error without compromising the construction of a conservative flux field, which is guaranteed at any iteration. Since it converges to the exact solution, the method can be regarded as a linear solver. In this context, the schemes proposed here can be viewed as preconditioned versions of the Generalized Minimal Residual method (GMRES), with a very peculiar characteristic that the residual on the coarse grid is zero at any iteration (thus conservative fluxes can be obtained).

Effects of L-carnitine supplemented total parenteral nutrition on lipid and energy metabolism in postoperative stress.

During episodes of trauma carnitine-free total parenteral nutrition (TPN) may result in a reduction of the total body carnitine pool, leading to a diminished rate of fat oxidation. Sixteen patients undergoing esophagectomy were divided randomly in two equal isonitrogenous groups (0.2 g/kg.day). Both received TPN (35 kcal/kg.day; equally provided as long-chain triglycerides and glucose) over 11 days without (group A) and with (group B) L-carnitine supplementation (12 mg/kg.day = 75 mumol/kg.day). Compared with healthy controls, the total body carnitine pool prior to the operation was significantly reduced in both groups, suggesting a state of semistarvation and muscle wasting. In group A the plasma levels of total carnitine and its subfractions (free carnitine, short- and long-chain acylcarnitine) remained stable during the study whereas in group B the total plasma carnitine concentration rose mainly due to an increase in free carnitine. In group A the cumulative urinary carnitine losses were 11.5 +/- 2.6 mmol (= 15.5 +/- 3.1% of the estimated total body carnitine pool). In group B 3.1 +/- 1.9 mmol (= 11.1 +/- 7.6%) of the infused carnitine was retained in the immediate postoperative phase until day 6, but this amount was completely lost at completion of the study period. No significant differences in the respiratory quotient or in the plasma levels of triglycerides, free fatty acids, and ketone bodies were observed, between or within the groups, before the operation and after 11 days of treatment. It is concluded that the usefulness of carnitine supplementation during postoperative TPN was not apparent in the present patient material.

Parenteral is more efficient than mucosal immunization to induce regression of human papillomavirus-associated genital tumors.

Cervical cancer is a public health concern as it represents the second cause of cancer death in women worldwide. High-risk human papillomaviruses (HPV) are the etiologic agents, and HPV E6 and/or E7 oncogene-specific therapeutic vaccines are under development to treat HPV-related lesions in women. Whether the use of mucosal routes of immunization may be preferable for inducing cell-mediated immune responses able to eradicate genital tumors is still debated because of the uniqueness of the female genital mucosa (GM) and the limited experimentation. Here, we compared the protective activity resulting from immunization of mice via intranasal (i.n.), intravaginal (IVAG) or subcutaneous (s.c.) routes with an adjuvanted HPV type 16 E7 polypeptide vaccine. Our data show that s.c. and i.n. immunizations elicited similar frequencies and avidity of TetE71CD81 and E7-specific Interferon-gamma-secreting cells in the GM, whereas slightly lower immune responses were induced by IVAG immunization. In a novel orthotopic murine model, both s.c. and i.n. immunizations allowed for complete long-term protection against genital E7-expressing tumor challenge. However, only s.c. immunization induced complete regression of already established genital tumors. This suggests that the higher E7-specific systemic response observed after s.c. immunization may contribute to the regression of growing genital tumors, whereas local immune responses may be sufficient to impede genital challenges. Thus, our data show that for an efficiently adjuvanted protein-based vaccine, parenteral vaccination route is superior to mucosal vaccination route for inducing regression of established genital tumors in a murine model of HPV-associated genital cancer.

Enteral versus parenteral nutrition: comparison of energy metabolism in lean and moderately obese women.

Continuous respiratory-exchange measurements were performed on ten moderately obese and ten lean young women for 1 h before, 3 h during, and 3 h after either parenteral (IV) or intragastric (IG) administration of a nutrient mixture infused at twice the postabsorptive, resting energy expenditure (REE). REE rose significantly from 0.98 +/- 0.02 to 1.13 +/- 0.03 kcal/min (IV) and from 0.99 +/- 0.02 to 1.13 +/- 0.02 kcal/min (IG) in the lean group; from 1.10 +/- 0.02 to 1.27 +/- 0.03 kcal/min (IV) and from 1.11 +/- 0.02 to 1.29 +/- 0.03 (IG) in the obese group. These increases resulted in similar nutrient-induced thermogenesis of 10.0 +/- 0.7% (IV) and 9.3 +/- 0.9% (IG) in the lean group; of 9.2 +/- 0.7% (IV) and 10.1 +/- 0.8% (IG) in the obese. Nutrient utilization was comparable in both groups and in both routes of administration, although the response time to IG feeding was delayed. These results showed no significant difference in both the thermogenic response and nutrient utilization between moderately obese and control groups using acute IV or IG feeding.

Vitamin C requirements in parenteral nutrition.

Some biochemical functions of vitamin C make it an essential component of parenteral nutrition (PN) and an important therapeutic supplement in other acute conditions. Ascorbic acid is a strong aqueous antioxidant and is a cofactor for several enzymes. The average body pool of vitamin C is 1.5 g, of which 3%-4% (40-60 mg) is used daily. Steady state is maintained with 60 mg/d in nonsmokers and 140 mg/d in smokers. Shocked surgical, trauma, and septic patients have a drastic reduction of circulating plasma ascorbate concentrations. These low concentrations require 3-g doses/d to restore normal plasma ascorbate concentrations, questioning the recommended PN dose of 100 mg/d. Determination of intravenous requirements is usually based on plasma concentrations, which are altered during the inflammatory response. There is no clear indicator of deficiency: serum or plasma ascorbate concentrations <0.3 mg/dL (20 micromol/L) indicates inadequate vitamin C status. On the basis of available pharmacokinetic data the 100 mg/d dose for patients receiving home PN and 200 mg/d for stable adult patients receiving PN are adequate, but requirements have been shown to be higher in perioperative, trauma, burn, and critically ill patients, paralleling oxidative stress. One recommendation cannot fit all categories of patients. Large vitamin C supplements may be considered in severe critical illness, major trauma, and burns because of increased requirements resulting from oxidative stress and wound healing. Future research should distinguish therapeutic use of high-dose ascorbic acid antioxidant therapy from nutritional PN requirements.

Direct visualization of supercoiled DNA molecules in solution.

The shape of supercoiled DNA molecules in solution is directly visualized by cryo-electron microscopy of vitrified samples. We observe that: (i) supercoiled DNA molecules in solution adopt an interwound rather than a toroidal form, (ii) the diameter of the interwound superhelix changes from about 12 nm to 4 nm upon addition of magnesium salt to the solution and (iii) the partition of the linking deficit between twist and writhe can be quantitatively determined for individual molecules.

The development of a stable oral solution of captopril for paediatric patients

Study objectives: Many major drugs are not available in paediatric form. The aim of this study was to develop a stable liquid solution of captopril for oral paediatric use allowing individualised dosage and easy administration to newborn and young patients. Methods: A specific HPLC-UV method was developed. In a pilot study, a number of formulations described in the literature as affording one-month stability were examined. In the proper long-term study, the formulation that gave the best results was then prepared in large batches and its stability monitored for two years at 5°C and room temperature, and for one year at 40°C. Results: Most formulations described in the literature were found wanting in our pilot study. A simple solution of the drug (1 mg/mL) in purified water (European Pharmacopeia) containing 0.1% disodium edetate (EDTA-Na) as preservative proved chemically and microbiologically stable at 5°C and room temperature for two years. Conclusion: The proposed in-house formulation fulfils stringent criteria of purity and stability and is fully acceptable for oral administration to newborn and young patients.

Parenteral nutrition in the intensive care unit: cautious use improves outcome.

Critical illness is characterised by nutritional and metabolic disorders, resulting in increased muscle catabolism, fat-free mass loss, and hyperglycaemia. The objective of the nutritional support is to limit fat-free mass loss, which has negative consequences on clinical outcome and recovery. Early enteral nutrition is recommended by current guidelines as the first choice feeding route in ICU patients. However, enteral nutrition alone is frequently associated with insufficient coverage of the energy requirements, and subsequently energy deficit is correlated to worsened clinical outcome. Controlled trials have demonstrated that, in case of failure or contraindications to full enteral nutrition, parenteral nutrition administration on top of insufficient enteral nutrition within the first four days after admission could improve the clinical outcome, and may attenuate fat-free mass loss. Parenteral nutrition is cautious if all-in-one solutions are used, glycaemia controlled, and overnutrition avoided. Conversely, the systematic use of parenteral nutrition in the ICU patients without clear indication is not recommended during the first 48 hours. Specific methods, such as thigh ultra-sound imaging, 3rd lumbar vertebra-targeted computerised tomography and bioimpedance electrical analysis, may be helpful in the future to monitor fat-free mass during the ICU stay. Clinical studies are warranted to demonstrate whether an optimal nutritional management during the ICU stay promotes muscle mass and function, the recovery after critical illness and reduces the overall costs.

Nutrition parentérale compé- mentaire de la nutrition entérale aux soins intensifs: une association logique [Supplemental parenteral nutrition for intensive care patients: a logical combination with enteral nutrition]

Undernutrition is a widespread problem in the intensive care and is associated with a worse clinical outcome. Enteral nutrition is the recommended nutritional support in ICU patients. However, enteral nutrition is frequently insufficient to cover protein-energy needs. The initiation of supplemental parenteral nutrition, when enteral nutrition is insufficient, could optimize the nutritional therapy. Such a combination could allow reducing morbidity, length of stay and recovery, as well as improving quality of life and health care costs. Prospective studies are currently underway to test this hypothesis.