Construction and biological characterization of an infectious molecular clone of HIV type 1GB8

Here we report the construction, sequencing, and repair of a molecular clone of HIV-1GB8, a virus representative of HIV-1 subtype B strains circulating in the UK. The phenotype of virus produced by the clone matches that of the parental virus. The molecular clone will be used in the production of attenuated virus stocks for chemical inactivation to allow development of faccines based on killed whole virus preparations.     

Toward the pharmacogenomics of cystic fibrosis--an update

Cystic fibrosis (CF) is the most common autosomal recessive disorder in Caucasians, with a frequency of approximately 1 in 3000 live births. The mutated gene is a defective chloride channel in epithelial cells, named cystic fibrosis transmembrane conductance regulator (CFTR). Several different protocols for the scanning of the entire gene have aided molecular diagnosis and improved our understanding of the disorder's pathophysiology, but also showed the disease's complexity. Therefore, CF phenotype remains difficult to predict from CFTR mutation data alone: several studies have suggested that additional genes could modulate its clinical outcome. Gene replacement therapy is still far from being used in patients with CF, mostly due to the difficulties with targeting the appropriate cells. In this review, we summarize recent advances, both in the pharmacological and gene therapy field, aimed for the treatment of the disease.     

The marine toxin dinophysistoxin-2 induces differential apoptotic death of rat cerebellar neurons and astrocytes.

Diarrhetic shellfish poisoning (DSP) toxins of algal origin are frequent contaminants of coastal waters and seafood. The potential risk for human health due to the continuous presence of these toxins in food has not been clearly established. We have used cerebellar primary cultures to investigate the effects of the DSP toxin dinophysistoxin-2 (DTX-2) on central nervous system neurons and glial cells. Exposure to DTX-2 produced neurotoxicity at concentrations starting at 2.5 nM, characterized first by disintegration of neurites and later by cell death. DTX-2-induced neurodegeneration required long exposures (at least 20 h), involved DNA fragmentation and condensation and fragmentation of chromatin, typical hallmarks of apoptosis, and required the synthesis of new proteins. The concentration that reduced by 50% the maximum neuronal survival after 24 h exposure to DTX-2 (EC50(24)) was approximately 8 nM. Morphology and viability of glial cells remained unaffected up to at least 15 nM DTX-2. Higher concentrations of the toxin caused strong shrinkage of glial cell bodies and retraction of processes, and a significant reduction of glial cell viability. Glial toxicity by DTX-2 involved typical apoptotic condensation and fragmentation of chromatin. Compared to neurons, the effect on glial cells was a much shorter process, and extensive glial degeneration and death occurred after 7 h exposure to DTX-2 (EC50(7) approximately 50 nM; EC50(24) approximately 30 nM). Although further experiments are needed to confirm these toxic actions in vivo, our in vitro data suggest that chronic exposure to amounts of DSP toxins below the current safety regulatory limits may represent a risk for human health that should be taken into consideration.     

Assessment and risk classification protocol for patients in emergency units

Objective

to develop, validate the contents and verify the reliability of a risk classification protocol for an Emergency Unit.

Method

the content validation was developed in a University Hospital in a country town located in the state of Sao Paulo and was carried out in two stages: the first with the individual assessment of specialists and the second with the meeting between the researchers and the specialists. The use of the protocol followed a specific guide. Concerning reliability, the concordance or equivalent method among observers was used.

Results

the protocol developed showed to have content validity and, after the suggested changes were made, there were excellent results concerning reliability.

Conclusion

the assistance flow chart was shown to be easy to use, and facilitate the search for the complaint in each assistance priority.     

Dermal exposure assessment of polycyclic aromatic hydrocarbons: in vitro percutaneous penetration from lubricating oil

Objectives: Percutaneous penetration of polycyclic aromatic hydrocarbons (PAHs) is affected by various factors connected to exposure conditions. The nature of the matrix, such as that of oil, can strongly affect their percutaneous penetration. Risk assessment should consider these effects. We examined the effect of matrix on percutaneous penetration of PAHs, particularly that of lubricating oil. Methods: The test apparatus consisted of an in vitro static diffusion cell system using full-thickness monkey (Cercopithecus aetiops) skin as the membrane and saline solution with gentamycin sulfate and 4% bovine serum albumin as receptor fluid. Chemical analysis of PAHs in the samples obtained from cells was carried out by inverse-phase HPCL, and the results were read by spectrofluorimetry. Results: Comparing the penetration of 13 PAHs from a lubricating oil and from acetone solution with artificial sweat resulted in a significantly slower passage from the oil matrix for acenaphthene, anthracene, phenanthrene, fluoranthene, naphthalene, pyrene, fluorene (Mann-Whitney U test, P < 0.05). No significant differences in the passage were found for chrysene because, in the test with oil, its concentration was very often below the detection limit. For benzo[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene it was possible to demonstrate a passage through the skin only when compounds were applied in acetone solution with artificial sweat. Conclusions: The results of the study suggest the necessity of dermal penetration data relevant for risk assessment, obtained under experimental conditions similar to the real exposure conditions. Received: 7 January 1999 / Accepted: 10 July 1999     

Pharmacokinetic evaluation of meropenem and imipenem in critically ill patients with sepsis

OBJECTIVE: To evaluate and compare the pharmacokinetic profiles of imipenem and meropenem in a population of critically ill patients with sepsis to find possible differences that may help in selecting the most appropriate drug and/or dosage in order to optimise empiric antimicrobial therapy. PATIENTS AND METHODS: This was a single-centre, randomised, nonblind study of the pharmacokinetics of both intravenous imipenem 1g and meropenem 1g in 20 patients admitted to an intensive care unit with sepsis in whom antimicrobial therapy was indicated on clinical grounds. Patients were divided into two groups: group I received intravenous imipenem 1g plus cilastatin 1g, and group II received intravenous meropenem 1g over 30 minutes. Peripheral blood samples were collected at 0, 0.5 (end of infusion), 0.75, 1, 1.5, 2, 3, 4, 6 and 8 hours after the first dose and were centrifuged for 10 minutes at 4 masculineC. Urine samples were collected during the 8 hours after antimicrobial administration at 2-hour intervals: 0-2, 2-4, 4-6 and 6-8 hours. The total volume of urine was recorded; the serum and urine samples were immediately frozen and stored at -80 masculineC until assayed. Pharmacokinetic analysis was carried out through computerised programs using the least-square regression method and a two-compartment open model. Statistical differences were evaluated by means of one-way ANOVA. RESULTS: The following pharmacokinetic differences between the two drugs were observed: the imipenem mean peak serum concentration was significantly higher than for meropenem (90.1 +/- 50.9 vs 46.6 +/- 14.6 mg/L, p < 0.01); the area under the serum concentration-time curve was significantly higher for imipenem than for meropenem (216.5 +/- 86.3 vs 99.5 +/- 23.9 mg . h/L, p < 0.01), while the mean volume of distribution and mean total clearance were significantly higher for meropenem than for imipenem (25 +/- 4.1 vs 17.4 +/- 4.5L, p < 0.01 and 191 +/- 52.2 vs 116.4 +/- 42.3 mL/min, p < 0.01, respectively). CONCLUSION: The more favourable pharmacokinetic profile of imipenem compared with meropenem in critically ill patients with sepsis might balance the possibly greater potency demonstrated in vitro for meropenem against Gram-negative strains. Hence, the clinical efficacy of the two carbapenems depends mostly on their correct dosage.     

Developing Toxicity Scores for Embryotoxicity Tests on Elutriates with the Sea Urchin Paracentrotus lividus, the Oyster Crassostrea gigas, and the Mussel Mytilus galloprovincialis

Bioassays are routinely employed for sediment quality assessment. In order to be able to effectively use Bioassays responses in regulatory and management frameworks, toxicity scores, which rank toxicity data in defined classes that are continuous and difficult to interpret, should be reliable and suitable tools to support decisions about the presence or absence of toxicity in tested samples and on how toxic a sample is. A statistical approach is needed to define thresholds for toxicity scores. The Minimum Significance Difference (MSD) criterion allowed the evaluation of toxicity thresholds for each test-matrix and organism pair, based on large sets of experimental data. The MSD values were normalized with respect to the control, ranked in ascending order, and the 90th percentile was identified; the Toxicity Threshold (TT) was calculated by subtracting the 90th percentile from 100 and the Toxicity Limit (TL) was estimated as the percentage of control response multiplied by TT. Taking into account sample responses normalized with respect to control (S), when S > TL, the sample is considered nontoxic; when S 相似文献   

Guidelines for health surveillance of health care workers exposed to biological risks set up by the Italian Society for Occupational Health and Industrial Hygiene: application in health facilities of the Regional Health Administration--District No. 7, Ancona

BACKGROUND: Evidence Based Medicine and the need to achieve better management of health budgets call for verification and, if necessary, revision of the criteria used in Occupational Health, in order to ensure appropriate measures as regards protection of health at the workplace. In December 2003, the Marche Region initiated a process of reform of the regional health service, which will be completed in two years, and will provide a new regional health organization that will improve the quality and appropriateness of health services available to the population. The reform also involves the Occupational Health Services responsible for prevention activities for 20,000 health care workers employed in regional public health facilities. The need was strongly felt to set up a network that would meet the health needs of health care workers, by adopting a common language among occupational health physicians, by eliminating reported criticism, which is due not only to lack of communication between different structures and profiles, but also to the different methods of approach, evaluation and management of occupational risks. OBJECTIVES AND METHODS: From a historical point of view, the health sector has the biggest as regards prevention of biological risk. Therefore, with a view to harmonizing actions and approach among occupational health physicians in the evaluation of this risk, the publication by the Italian Society for Occupational of Health and Industrial Hygiene of Guidelines for health surveillance of health care workers exposed to biological risks, produced by the working group under the leadership of Prof. Lorenzo Alessio, was considered to offer an interesting opportunity to verify the reproducibility of methods and the quality of results, as applied to health facilities under the Regional Health Administration in Ancona (District No. 7). RESULTS AND CONCLUSION: The Guidelines fully confirmed the need to plan activities, starting from analysis of epidemiological and occupational data, thus assuring good results both in terms of efficacy and efficiency of the health surveillance programme used. This method also assures a high level of appropriateness of medical measures as regards the "safety" target, at the same time avoiding waste and poor management of human and economic resources, which were till now caused by differences in methods used in assessment of biological risk.     

Excitatory amino acid signal transduction in cerebellar cell cultures

In primary cultures of cerebellar granule cells excitatory amino acid recognition sites are coupled with the stimulation of inositol phospholipid (PI) hydrolysis, cGMP formation and 45Ca2+ uptake. Mg2+, 2-amino-5-phosphonovalerate (APV) and phencyclidine (PCP) potently inhibit signal transduction in response to N-methyl-D-aspartate (NMDA), glutamate (GLU) and aspartate (ASP). Activation by quisqualate (QUIS) is transduced selectively into stimulation of PI hydrolysis and this response is not sensitive to inhibition by Mg2+, APV and PCP. Activation by kainate (KA) is transduced into potent stimulation of cGMP formation and 45Ca2+ uptake. Transduction of KA signal is not affected by Mg2+ and is relatively insensitive to PCP and APV.