Synergy of the Tropical Earthworm Pontoscolex corethrurus and Oil Palm Bagasse in the Removal of Heavy Crude Oil

The tropical endogeic earthworm Pontoscolex corethrurus, a non-standard species used in ecotoxicity, has been found in crude oil-contaminated habitats. We estimated the removal of total hydrocarbons from heavy crude “Maya” oil on an artificially contaminated soil with a median lethal concentration of P. corethrurus and an addition of oil palm bagasse. P. corethrurus had a high survival rate, and the addition of oil palm bagasse led to a greater growth and an increase in abundance of bacteria and fungi. The activity of P. corethrurus and the nutritional quality of oil palm bagasse had a significant impact on the removal of a larger amount of petroleum hydrocarbons from contaminated soil. We concluded that the endogeic earthworm P. corethrurus and oil palm bagasse acted synergistically to achieve a more effective removal of total petroleum hydrocarbons from soil. These results show the potential for using P. corethrurus to remove, either directly or indirectly, crude oil from soil.

     

Procedural sedation in the acute care setting

Many patients require sedation during diagnostic or therapeutic procedures. Ideally, procedural sedation minimizes the patient's awareness and discomfort while maintaining the patient's safety. Appropriate monitoring by trained personnel is the key to successful procedural sedation. These techniques should be used only by health care professionals skilled in managing complications, including cardiorespiratory compromise. It is important to take a complete history and perform a thorough physical examination, paying special attention to the selection of pharmacologic agents. Common sedative agents include etomidate, ketamine, fentanyl, and midazolam. These have become the agents of choice for procedural sedation because of their ease of use, predictable action, and excellent safety profiles. All patients requiring procedural sedation should be monitored by qualified staff at the bedside until they have recovered to an age-appropriate baseline mental status and function.     

Interaction between grapefruit juice and praziquantel in humans

After a single oral dose of praziquantel with 250 ml of grapefruit juice, the area under the concentration-time curve and the maximum concentration in plasma of praziquantel (Cmax) were significantly increased (Cmax for water treatment, 637.71 +/- 128.5 ng/ml; and Cmax for grapefruit juice treatment, 1,037.65 +/- 305.7 ng/ml, P < 0.05). No statistically significant differences were found in the time to maximum concentration of drug in plasma or elimination half-life.     

In vitro characterization of some biopharmaceutical properties of praziquantel

In several studies of patients with neurocysticercosis under treatment with praziquantel (PZQ), the pharmacokinetic data were difficult to interpret probably because of the low solubility as well as its variable oral bioavailability. Because there is limited information available regarding the biopharmaceutical properties of PZQ, the aim of this work was to evaluate the absorption characteristics of the drug and its dissolution behaviour in simulated media. Additionally, its in vitro protein binding and displacement by highly bound drugs was evaluated. Permeability evaluation was carried out by using Caco-2 cells. Dissolution release profiles were evaluated using the USP apparatus and the following dissolution media: HCl containing 2mg of sodium laurylsulfate per milliliter, milk, FeSSIF and FaSSIF. Protein binding of PZQ was carried out by equilibrium dialysis. Results showed that praziquantel was absorbed by passive diffusion. The apparent permeability constant value was 4.4x10(-5) cm/s. Binding was not influenced by the addition of highly bound drugs. Dissolution from a tablet formulation showed that the rate of praziquantel was dependent on the components of the media. Although the simulated media could explain the influence of the lipids on praziquantel absorption, they were not able to forecast the influence of carbohydrates. Further refinements are required to explain the in vivo data.     

Assessment of the in‐vivo drug release from pellets film‐coated with a dispersion of high amylose starch and ethylcellulose for potential colon delivery

Objectives The aim of this study was to test the ability of a colon targeting system comprising pellets film‐coated with a dispersion of high amylose starch (Hylon VII) and ethylcellulose (Surelease) (1 : 2 w/w) to deliver a model drug (5‐aminosalicylic acid; 5‐ASA) in vivo into the colon of rabbits. An uncoated pellet formulation was used as a control. Methods Six New Zealand female rabbits, approximately 2 kg, were randomly divided into two groups. Pellet formulations containing 50 mg/kg of 5‐ASA were filled into hard gelatin capsules size 4, and were administered orally using a cannula. The rabbits were fasted for 12 h before, and throughout, the study but had free access to water. Blood samples were collected, through a catheter inserted into the marginal vein of the ear, at pre‐determined times and the plasma analysed by a validated HPLC method with fluorescence detection. Results Analysis of the 5‐ASA plasma levels following administration of the uncoated pellets showed a C_max of 2.38 ± 0.49 μg/ml at 2 h post administration confirming that this system released the drug at an unspecific site, most likely in the rabbits' stomach and proximal small intestine. On the other hand, the coated formulation showed a delayed drug absorption (C_max 0.22 ± 0.19 μg/ml and t_max of 8 h), suggesting that the coating is able to prevent drug release in the stomach and small intestine, but allowing drug release in the colon. The coated pellets were retrieved from the rabbits' faeces after the 24‐h study. They had a drug content of < 40%, suggesting that the film‐coating had been digested by the bacterial amylases of the colon and the drug was released specifically in the colon of the rabbits. Conclusions Results from this study showed that the proposed drug delivery system has the potential to deliver drugs specifically into the colon.     

Single dose pharmacokinetics of HEPP,a new anticonvulsant in normal healthy volunteers

The pharmacokinetics and the dose proportionality of a new anticonvulsant compound, HEPP (D ,L -3-hydroxy-3-ethyl-3-phenylpropionamide) was studied in healthy male volunteers as part of the pharmacological evaluation for new drugs. Study was performed administering doses of 250, 375, 500 and 625 mg of HEPP to six male volunteers. Blood and urine samples were collected for 72 h postdose and analysed by HPLC. Results showed that in man HEPP is rapidly absorbed from the gastrointestinal tract. T_max values were between 1.5 and 6.0 h. Plasma mean terminal half-life after the different doses ranged between 15.83 and 27.62 h with an overall harmonic mean value of 22.8. The mean AUC_0–∞ and C_max increased linearly with doses of 250, 375 and 500 mg but not with the dose of 625 mg. The amount of unchanged drug excreted in urine was between 3 and 6% of administered dose which shows an extensive metabolism of the drug. © 1998 John Wiley & Sons, Ltd.     

Commonly performed procedures in clinical research: a benchmark for payment

Slow or insufficient enrollment in clinical research and a high demand for research participants raises questions about the need for and use of incentives to participate, including payment. Much of the available literature on payment to research participants focuses on ethical concerns, and rarely addresses guidelines, benchmarks, or formulas to assist investigators to assign or evaluate appropriate payment for individuals who take part in clinical research trials and procedures. Using four years of data collected about the inconvenience units assigned by intramural investigators to selected clinical research procedures conducted at the National Institutes of Health (NIH) Clinical Center, this study provides payment benchmarks for commonly performed procedures. Results were obtained from data collected on 36,273 incidents of payment made for procedures to research participants from August 2004 to August 2008. Analysis of the inconvenience units value assigned to specific procedures suggests that despite a wide distribution and frequent outliers, a convergence in practice around the center of distribution for most procedures does exist. As one of the first published studies reporting data reflecting payment amount for specific clinical research procedures, these data can guide investigators and institutional review boards as they establish and review an appropriate amount of payment to offer research participants. Our data may be useful in promoting payment standards for procedures, thereby complementing proposals or guidelines that advise payment calculations according to time and procedures.     

Analysis of TPI gene promoter variation in three sub‐Saharan Africa population samples

Population samples from Angola, Mozambique, and S. Tomé e Príncipe were screened for the TPI gene promoter variants ‐5A→G, ‐8G→A and ‐24T→G. Three haplotypes were identified in the three populations: the haplotype ‐5A‐8G‐24T (average frequency 65.3%) and two less common haplotypes ‐5G‐8G‐24T (average frequency 24.7%) and ‐5G‐8A‐24T (average frequency 10.0%). A population sample from Central Portugal showed the haplotype ‐5A‐8G‐24T in 139 chromosomes and one subject heterozygous for haplotype ‐5G‐8A‐24G. The exact test of sample differentiation among three groups of malaria‐infected individuals classified according to the severity of the disease showed no significant differences. We confirmed TPI gene diversity in sub‐Saharan Africa, but we could not detect any association between TPI promoter variation and a malarial protective effect. Larger scale epidemiological studies are thus required to clarify this putative mechanism of natural host defense against this worldwide public health problem. Am. J. Hum. Biol., 2009. © 2008 Wiley‐Liss, Inc.