Evaluation of the MB/BacT mycobacterium detection system for susceptibility testing of Mycobacterium tuberculosis

The MB/BacT mycobacterium detection system was evaluated for its performance in the susceptibility testing of Mycobacterium tuberculosis. Eighty-three M. tuberculosis isolates were processed. Results for all isoniazid-, rifampin- and streptomycin-susceptible, isoniazid-resistant, and rifampin-resistant M. tuberculosis isolates with the MB/BacT system agreed 100% with those obtained by the agar proportion method. The agreements between the two methods for streptomycin- and ethambutol-resistant isolates were 96.4 and 90.4%, respectively. The susceptibility test results were obtained in 7 days, on average. These data demonstrate that the MB/BacT system is an accurate, nonradiometric method for rapid susceptibility testing of M. tuberculosis.

The Drosophila fl(2)d gene, required for female-specific splicing of Sxl and tra pre-mRNAs, encodes a novel nuclear protein with a HQ-rich domain

The Drosophila gene female-lethal(2)d [fl(2)d] interacts genetically with the master regulatory gene for sex determination, Sex-lethal. Both genes are required for the activation of female-specific patterns of alternative splicing on transformer and Sex-lethal pre-mRNAs. We have used P-element-mediated mutagenesis to identify the fl(2)d gene. The fl(2)d transcription unit generates two alternatively spliced mRNAs that can encode two protein isoforms differing at their amino terminus. The larger isoform contains a domain rich in histidine and glutamine but has no significant homology to proteins in databases. Several lines of evidence indicate that this protein is responsible for fl(2)d function. First, the P-element insertion that inactivates fl(2)d interrupts this ORF. Second, amino acid changes within this ORF have been identified in fl(2)d mutants, and the nature of the changes correlates with the severity of the mutations. Third, all of the phenotypes associated with fl(2)d mutations can be rescued by expression of this cDNA in transgenic flies. Fl(2)d protein can be detected in extracts from Drosophila cell lines, embryos, larvae, and adult animals, without apparent differences between sexes, as well as in adult ovaries. Consistent with a possible function in posttranscriptional regulation, Fl(2)d protein has nuclear localization and is enriched in nuclear extracts.

Acoustic analysis after radiotherapy in T1 vocal cord carcinoma: a new approach to the analysis of voice quality

PURPOSE

The study of acoustic voice parameters (fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio) in extended vowel production, oral reading of a standard paragraph, spontaneous speech and a song in irradiated patients for Tis-T1 vocal cord carcinoma.

METHODS AND MATERIALS

Eighteen male patients irradiated for Tis-T1 vocal cord carcinoma and a control group of 31 nonirradiated subjects of the same age were included in a study of acoustic voice analysis. The control group had been rigorously selected for voice quality and the irradiated group had previous history of smoking in two-thirds of the cases and a vocal cord biopsy. Radiotherapy patients were treated with a 6MV Linac receiving a total dose of 66 Gy, 2 Gy/day, with median treatment areas of 28 cm(2). Acoustic voice analysis was performed 1 year after radiotherapy, the voice of patients in extended vowel production, oral reading of a standard paragraph, spontaneous speech, and in a song was tape registered and analyzed by a Kay Elemetric's Computerized Speech Lab (model CSL# 4300). Fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio were obtained in each case. Mann Whitney analysis was used for statistical tests.

RESULTS

The irradiated group presented higher values of fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio. Mann-Whitney analysis showed significant differences for fundamental frequency and jitter in vowel production, oral reading, spontaneous speech, and song. Shimmer only showed differences in vowel production and harmonics-to-noise ratio in oral reading and song.

CONCLUSIONS

In our study only fundamental frequency and jitter showed significant increased values to the control group in all the acoustic situations. Sustained vowel production showed the worst values of the acoustic parameters in comparison with the other acoustic situations. This study seems to suggest that more work should be done in this field.

Clinical and economic impact of a pharmacist-intervention to promote sequential intravenous to oral clindamycin conversion

A multicentre, prospective, controlled study compared the clinical efficacy, safety and economic impact of a pharmacist intervention to promote sequential intravenous to oral clindamycin conversion. A total of 473 patients receiving intravenous clindamycin for at least 72 hours were included in the study. Two groups were established: an intervention group (204 patients) in which an informative sheet recommending the sequential treatment was provided, and a control group (269 patients). Clindamycin was prescribed for respiratory infections in 38.9% and for prophylaxis in surgery in 25.4% of the patients (71% were contaminated surgery). No difference between groups regarding sex, infection severity, health status or clinical progress was observed. Both the step-down treatments after 72 hours of intravenous clindamycin and the change to the oral route later on, were significantly increased with the intervention (p < 0.001, p < 0.001 respectively). No significant differences between both groups were found in the number of patients with adverse effects associated with the i.v. therapy, although the incidence tended to be lower in the intervention group (49/204 intervention versus 85/269 control, p = 0.07). Compliance with the recommended clindamycin dosing regimen was significantly higher in the intervention group, in which 1.3 days reduction of intravenous therapy provided an average cost savings of PTA5246 (95% CI 2556-7935) per treatment. A higher reduction of 1.7 days was achieved in those patients candidates for switch therapy on the third day of intravenous clindamycin. A sequential program with clindamycin may provide a cost-effective alternative to conventional therapy and the introduction of an information sheet is a cost-effective strategy to promote it.

New Natural Hosts of Tomato spotted wilt virus

Tomato spotted wilt virus (TSWV) has caused epidemics in recent years in many crops throughout the Mediterranean Region. Tomato, pepper, and lettuce are the crops most affected in Spain. To determine the reservoir hosts for the virus in the area, 210 samples from 95 species of plants were collected and tested for TSWV by double-antibody sandwich enzyme-linked immunosorbent assay with commercial antisera (Loewe Biochemica, Germany: BR-01, serogroup I or TSWV-L). Twenty-one species tested positive, and among them were thirteen newly identified hosts for TSWV (1). Weed species were among the 13 new hosts and included Diplotaxis erucoides (L.) DC., Beta maritima L., Phragmites communis Trin., Malva sylvestris L., Sonchus arvensis L., Sorghum halepense L., Panicum repens L., Atriplex patula L., Coronopus squamatus (Forssk.) Ascherson, Cuscuta sp., Xanthium spinosum L., Suaeda vera J.F., and Ecballium elaterium (L.) A. Rich. Most of these plants were asymptomatic hosts, but the Sonchus sp. showed typical symptoms of TSWV, such as yellows, bronzing, ring spots, necrosis, curling of young leaves, and growth reduction. D. erucoides, B. maritima, M. sylvestris, X. spinosum, and E. elaterium showed chlorosis and growth reduction. Reference: (1) C. Jorda et al. 1998. Anexo no. 3. Pages 381-386 in: The Health of Tomato Crops. Phytoma-España S. L., Valencia, Spain.

[Subdural empyema due to Mycoplasma hominis following epidural anesthesia]

INTRODUCTION

In the literature there are sporadic reports of spinal epidural abscesses after epidural anaesthesia (Staphylococcus aureus in 82%), whilst subdural empyemas are more often related to ear and sinus conditions.

CLINICAL CASE

A 32 year old woman with a clinical history of migraine and symmetrical frontal atrophy on a previous cerebral CT scan, after Caesarean section under epidural anaesthesia, presented with orthostatic headache two days later. On the fourth day it had become constant and she had a high temperature which was considered to be caused by infection of the surgical wound. Neurological examination was found to be normal, the CT scan was inconclusive and the CSF showed a lymphocytic pleocytosis without consumption of glucose. In view of her worsening clinical condition on the ninth day, in the absence of a cutaneous focus and on suspicion of a para-meningeal infective focus, lumbar MR was done and found to be normal, and cerebral MR which showed images compatible with a right fronto-parietal subdural empyema. After a parietal craniotomy and culture of the surgical specimen, colonies of Mycoplasma hominis were grown, similar to those grown from the exudates of the abdomical surgical wound. Treatment was started with ciprofloxacine.

CONCLUSION

We consider that following epidural anaesthesia the patient developed hypotension of the CSF with a secondary subdural hematoma or hygroma and this became infected by hematogenous spread of Mycoplasma hominis.

[Usefulness of spect with 99mTc-tetrofosmin and stimulus with dipyridamole in patients with left bundle branch block of His]

BACKGROUND

In patients with left bundle branch block, the 201Tl scintigraphic studies show high sensitivity, but with low specificity, in the diagnosis of coronary artery disease.

OBJECTIVE

[corrected] To assess the value of 99mTc-tetrofosmin Single Photon Emission Computed Tomography (SPECT) and dipyridamole administration in patients with left bundle branch block.

METHODS

22 patients with angina and left bundle branch block were retrospectively studied by cardiac catheterization and Tc-Tf after dipyridamole administration (0,142 mg/kg/min. i.v.) and at rest.

RESULTS

The mean number of territories with perfusion defects was 1.5+/-1.0, and the average number of diseased vessels in the coronariographic study was 1.6+/-1.3 (r = 0.77, p<0.001). Sensitivity, specificity, positive predictive value, negative predictive value, total predictive value and Kappa index in the diagnosis of multivessel disease were 92%, 90%, 92%, 90%, 91% and 0.82, respectively. In the diagnosis of anterior descending artery disease, these values were 83%, 70%, 77%, 78%, 77%, and 0.54, respectively.

CONCLUSION

In patients with angina and left bundle branch block, SPECT with Tc-Tf-dipyridamole is of great value in the study of coronary artery disease extension. Sensitivity and specificity for the diagnosis of anterior descending artery disease were similar to that shown in series with thallium-dipyridamole.

Abdominal insufflation does not cause hematogenous spread of colon cancer

BACKGROUND AND PURPOSE

Previous investigators have suggested that port-site recurrences are possibly a result of abdominal insufflation, forcing viable cancer cells into the circulation to metastasize and thrive in areas of trauma. Using a syngeneic animal cancer model, we tested the hypothesis that pneumoperitoneum increases the incidence of wound metastasis by a blood-borne mechanism.

METHODS

Male BD IX rats (N = 150) were injected intraperitoneally with 2 x 10(5) viable syngeneic 1,2-dimethylhydralazine-induced colon cancer cells (DHD-K12). Animals were divided into three groups: A (abdominal insufflation with 3-cm incision on the back into muscle remote from the peritoneum); B (3-cm back incision alone); and C (control group with 3-cm midline abdominal incision). Three weeks after surgery, the animals were euthanized and autopsied.

RESULTS

In the two groups with back wounds, the incidence of cancer growth at the incision was zero, as demonstrated grossly and by histologic sample (A: 0/47, B: 0/43). In contrast, the autopsied control group had a 42% incidence of metastasis to the wound (25/59). There seemed to be no difference in the distribution of intra-abdominal disease between those rats that underwent insufflation and those that did not.

CONCLUSION

It is unlikely that pneumoperitoneum promotes hematogenous wound implantation of free intraperitoneal cancer cells.

Blood strontium concentration related to the length of the agonal period in seawater drowning cases

The levels of ventricular blood strontium (Sr) from 70 seawater drowning victims were compared with their diagnosis of drowning based mainly on certain criteria selected from their autopsy report. From this comparison, intervals of either the difference of Sr concentration between the left and the right ventricle blood (LVSr-RVSr) or the Sr concentration in the left ventricle blood (LVSr), appear to be related to different time-lapses of the agonal period of drowning. In the aim to diagnose drownings, intervals of both LVSr-RVSr and LVSr were proposed to characterize three different agonal periods in seawater drowning cases: instantaneous death (ID), fast vital-submersion drowning (FVSD) and common vital-submersion drowning (CVSD).

[Use of the CD-ROM "Tox-Didact" for teaching of toxicology and pharmacology]

Tox-Didact is a multimedia teaching software package for initial training, continuing training and self-learning of toxicology and pharmacology. This software covers a large part of toxicology in its acute and chronic pathology using several approaches: drugs (salicylics, paracetamol, lithium ...); toxins (lead, methanol, carbon monoxide ...); drug addiction and doping (cocaine, heroin, LSD, amphetamines ...); systemic targets (kidneys, skin, liver ...). Tox-Didact is currently composed of 39 modules in validation, each tackling the diagnosis, biological surveillance, treatment, prevention and documentation of a real clinical case. Each module is organized around four types of questions, requiring a choice either (drug, symptom, formula ...) or an open response. Each validated answer is analysed by software which then comments on or corrects it. The essential points which characterize this software are: its multidisciplinarity (toxicology, pharmacology, semiology ...), its reliability (validated by experts), its simplicity of use. It is modular and offers an interactive teaching approach. The objective is to create a portable multimedia tool operational with all computer systems (IBM PC, Macintosh). This program is sustained by the Région des Pays de la Loire and by the Multimedia Resource Office of the French Ministry of National Education.

Polystachynes A-E, five cis-neo-clerodane diterpenoids from Salvia polystachya

From the aerial parts of Salvia polystachya five new neo-clerodane diterpenoids, polystachynes A-E, have been isolated. The structures were established by spectroscopic methods, including the X-ray analysis of polystachynes C and D. The known clerodanes salvifaricin, linearolactone and dehydrokerlin were also isolated.

Line-based, reduced memory, wavelet image compression

This paper addresses the problem of low memory wavelet image compression. While wavelet or subband coding of images has been shown to be superior to more traditional transform coding techniques, little attention has been paid until recently to the important issue of whether both the wavelet transforms and the subsequent coding can be implemented in low memory without significant loss in performance. We present a complete system to perform low memory wavelet image coding. Our approach is "line-based" in that the images are read line by line and only the minimum required number of lines is kept in memory. There are two main contributions of our work. First, we introduce a line-based approach for the implementation of the wavelet transform, which yields the same results as a "normal" implementation, but where, unlike prior work, we address memory issues arising from the need to synchronize encoder and decoder. Second, we propose a novel context-based encoder which requires no global information and stores only a local set of wavelet coefficients. This low memory coder achieves performance comparable to state of the art coders at a fraction of their memory utilization.

Economic evaluation of Viaflex with vial adapter in a unit-dose drug distribution system

The cost of parenteral admixtures has an important impact on the hospital budget. Recently, a Viaflex with vial adapter (named 'minibag plus' in some countries) has been commercialized in order to facilitate parenteral admixture preparation. In the present study a preparation using Viaflex with a vial adapter has been economically compared with a preparation with a traditional Viaflex (without adapter) in a centralized unit or in nursing wards in a unit-dose drug distribution system. A cost-analysis was conducted from the hospital point of view. Direct costs were considered: these included supplies and human resources. Differences in the whole process between the two types of Viaflex were analysed. The process included: purchasing, reception, storage, medical order record, preparation in the Pharmacy Service (PS), delivery from the PS to the nursing unit, preparation by the nurse, return of unused material to the PS. Human resource costs were estimated by time counting and multiplying by the average salary. To estimate wasted material, drug and supplies delivered from the PS and returned to the PS were counted during 26 days. With the new Viaflex costs are reduced by 30% in comparison with drug dilution using the traditional Viaflex in a centralized unit of the PS, and by 13.4% in comparison with preparation with the traditional Viaflex in the nursing ward. In addition it can be estimated that contamination risk with the new Viaflex is lower than preparation in the nursing ward with the traditional Viaflex. Therefore, owing to its lower cost we recommend the use of Viaflex with vial adapter for drug dilution for those vials that are compatible with the system.

Alpha-adrenoceptor-mediated pressor responses in pithed rats fed diets with different calcium contents

Results of many clinical and experimental studies indicate an inverse relationship between dietary calcium and the prevalence of hypertension. Our study was designed to evaluate the alterations in arterial blood pressure and the changes in alpha-adrenoceptor-mediated vascular reactivity in normotensive Sprague-Dawley and spontaneously hypertensive rats (SHR) fed from weaning (3 weeks of life) three diets: normal calcium (Ca 1%), low calcium (Ca 0.1%), and high calcium (Ca 2.5%). The systolic and the diastolic arterial blood pressures were measured weekly by the tail cuff method. The plasma calcium levels in the animals were also measured regularly by colourimetric methods, and the alpha-adrenoceptor-mediated vascular reactivity was evaluated by measuring the pressor responses to alpha-adrenoceptor agonists in pithed rats. These determinations were carried out at the end of the feeding periods (9 weeks of life in Sprague-Dawley rats and 20 weeks of life in SHR) and also at the moments when maximal differences in arterial blood pressure were observed between the conscious animals fed the normal calcium diet and those fed the other two diets. Dietary calcium deficiency increased arterial blood pressure in both strains but calcium supplements were effective to lower this only in hypertensive animals. The plasma calcium levels were altered in both strains when calcium administration was not normal. The low-calcium diet did not modify the pressor responses to either the alpha(1)-adrenoceptor agonist, methoxamine, or the alpha(2)-adrenoceptor agonist, B-HT 920 (5-allyl-2-amino-5,6,7, 8-tetrahydro-4H-thiazolo-(4,5-D)-acepin-dihydrochloride, talixepole), in the normotensive and the hypertensive rats. On the contrary, the high-calcium diet caused a definite decrease in alpha(1)- and alpha(2)-adrenoceptor-mediated vascular reactivity in both strains. The changes in the alpha-adrenoceptor-mediated vasoconstrictor responses were observed in pithed 9-week old Sprague-Dawley rats and in pithed 20-week old SHR, but none were observed in pithed 15-week old SHR, although at this age maximal differences in arterial blood pressure between the animals fed the high- and the normal calcium diet were observed. The results of this study suggest that the mechanisms implicated in the effects of dietary calcium supplements on arterial blood pressure are clearly different from the mechanisms, which bring about changes in arterial blood pressure when the diet is deficient in calcium. The results of this study also show that calcium administration causes variations in alpha-adrenoceptor-mediated vascular reactivity, but this is probably not the only mechanism implicated in the calcium effect on arterial blood pressure.

[Scintigraphy diagnosis of renovascular hypertension in renal transplanted patients]

Captopril renography (CR) has been shown to be a useful technique in the diagnosis of renovascular hypertension (RVH). This disease is a significant complication of the kidney transplanted patient so that early diagnosis would be extremely useful to preserve renal function and prevent graft loss. This work evaluates the role of CR, together with arteriography and doppler-ultrasound, in the diagnosis of RVH.

MATERIALS

A total of 19 transplanted patients with clinical suspicion of RVH underwent an isotopic study, a doppler-ultrasound study and an arteriography. Scintigraphy was performed 1 hour after a 50 mg dose of captopril, with oral hydration and i.v. administration of approximately 111 MBq of 99mTc-MAG3 and 20 mg of furosemide. If abnormal, a subsequent renography in baseline conditions was performed for comparison.

RESULTS

Overall, 11 patients had renovascular hypertension. Sensitivity and specificity of CR were 91% and 80% respectively, 100% and 60% for US and 91% and 100% for arteriography. The CR yielded one false positive result and 2 false negatives cases: one with 50% stenosis and one polar artery stenosis. Six patients were successfully dilated or operated.

CONCLUSION

CR seems to be a reliable diagnostic tool for the diagnosis of renovascular hypertension in kidney transplanted patients.

Relationship between pharmacokinetic parameters of gentamicin and patient characteristics and/or clinical data in patients with solid organ tumours

Gentamicin monitoring and the selection of the initial dosage are generally based on the relationship between pharmacokinetic parameters of gentamicin (GPP) and patient characteristics and/or clinical data (PC). However, the number of studies about this relationship in cancer patients is limited. Therefore, the main objective of the present study was to evaluate the relationship between GPP and PC in cancer patients and to identify different subgroups within this group of patients with unique relationship models between GPP and PC. A total of 198 cancer patients were included in the study. Firstly, GPP were estimated by the Sawchuk and Zaske regression method. Then, a linear regression analysis was performed to investigate the relationship between GPP and PC, and lastly subgroups with unique models were identified by comparing their regression models. The results revealed that the variable which was the best predictor of the distribution volume of gentamicine was the dosing weight (DW = IBW + (ABW-IBW), ABW being the actual body weight and IBW the ideal body weight). Creatinine clearance (CLCR) measured by a 24-hour urine collection (CLCRu) was the best predictor of gentamicin clearance (CL). When this value is not available, the CLCR estimated by the formula of Crockcroft and Gault (C-G), can be used. When the C-G formula was used, unique models to predict CL from CLCR were identified for patients who were obese, patients who had received high-dose chemotherapy and, for subjects who had never developed aplasia following chemotherapy. Whichever the model used, the results showed that some variability in pharmacokinetic parameters of gentamicin was not explained by the models, especially in some groups of patients.

Stat3 participates in the metabotropic glutamate signaling pathway in Bergmann glial cells

Purkinje cells establish a glutamatergic synapse with the parallel fibers in the cerebellum. Bergmann glial cells surround this synapse. The transcription factor Stat3, highly expressed in cerebellum, is present in cultures of chick Bergmann glia. Treatment of these cells with L-glutamate induces the tyrosine-phosphorylation of Stat3. The maximal phosphorylation was observed after 15 min and by 30 min returned to basal levels. This effect correlated with Stat3 translocation to nucleus and the appearance of a retarded band in gel mobility shift assays. The effects observed with L-glutamate were mediated through metabotropic glutamate receptors. These results further support the notion that glial cells respond to L-glutamate through changes in the existing proteins and also in gene expression regulation.

Mycobacterium tuberculosis subsp. caprae subsp. nov.: a taxonomic study of a new member of the Mycobacterium tuberculosis complex isolated from goats in Spain

Isolates from the Mycobacterium tuberculosis complex cultured from caprine pathological tissue samples were biochemically and genetically characterized. The isolates were negative for nitrate reduction and niacin accumulation, they weakly hydrolysed Tween 80, were sensitive to pyrazinamide (50 micrograms ml-1) and were resistant to 1 and 2 micrograms tiophene-2-carboxylic acid hydrazide ml-1 but not to 5 or 10 micrograms tiophene-2-carboxylic acid hydrazide ml-1. Sequencing of the pncA gene revealed a polymorphism characteristic of M. tuberculosis, whereas oxyR, katG and gyrA sequences were characteristic of Mycobacterium bovis. The fingerprinting patterns obtained with IS6110, direct repeats and polymorphic G+C-rich sequence-associated RFLP and direct variable repeat-spacer oligonucelotide typing (spoligotyping) segregated these isolates from the other members of the complex. The results of this testing, together with the repeated association of this micro-organism with goats, suggest that a new member of this taxonomic complex not matching any of the classical species had been identified. This unusual mycobacterium may play a role in the epidemiology of animal and human tuberculosis in Spain. The name Mycobacterium tuberculosis subsp. caprae subsp. nov. is proposed for these isolates. The type strain of Mycobacterium tuberculosis subsp. caprae subsp. nov. is gM-1T (= CIP 105776T).

Sodium-dependent glutamate transport in Müller glial cells: regulation by phorbol esters

The regulation of the Na(+)-dependent high affinity glutamate/aspartate transporter system expressed in cultured Müller glia cells from chick retina was studied. Treatment of the cells with the Ca(2+)/diacylglycerol dependent protein kinase C (PKC) activator, phorbol 12-tetradecanoil-13-acetate (TPA) produced a decrease in [(3)H]D-aspartate uptake which was reversed by staurosporine and partially by H7 [1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochoride], two PKC inhibitors. Long-term treatment with TPA resulted in a drastic decrease in the uptake activity, correlated with a substantial fall in the expression of the transporter protein. These findings suggest that PKC is involved in transport modulation at two different levels: phosphorylation and transporter expression in retinal Müller glial cells.

[A comparative study between different regimens for administering 2 doses of the Cuban anti-hepatitis B vaccine]

A controlled clinical trial, corresponding to stage 2, was conducted in a population of sound adult males aged 18-23 to evaluate the immunogenicity of 5 schedules of Cuban vaccine against hepatitis B (Heberbiovac-HB [correction of Cheberbiovac-HB]). 5 groups were studied: I (control group 0, 1 and 6 months), II (0 and 2 months), III (0 and 4 months), IV (0 and 6 months), and V (0 and 8 months). The results showed no significant differences as regards the percentage of seroprotection of any of the groups of 2 doses compared with the control of 3 doses. It is concluded that between the first and the second dose there may be a period of time from 2 to 6 months with no need to reinitiate the schedule. This information will serve as a basis for a population based study to determine which schedule is the best to be used.

Presence of a nitric oxide synthase inhibitor in the graft efflux during reperfusion in human liver transplantation

Involvement of the nitric oxide (NO) system in complications following human orthotopic liver transplants (OLT) has been reported, but the contribution of the graft to the modulation of the NO system during reperfusion in normal OLT has not been characterized. We have studied the contribution of the graft efflux to the modulation of the NO system in 20 consecutive OLT. We evaluated its effects on isolated vascular reactivity of the rabbit and on rat cultured macrophages stimulated with lipopolysaccharide (LPS). In none of the donor liver biopsies was expression of inducible NO synthase (iNOS) activity by Northern or Western blot analysis found. Graft efflux after the onset of liver reperfusion, but not pre-transplant patient plasma, reversibly inhibited the acetylcholine-induced relaxation of norepinephrine-contracted rabbit aortic rings. Moreover, graft efflux reversibly inhibited NO production in rat macrophages treated with LPS, as evidenced by both a decrease in nitrite plus nitrate formation and a decrease in the production of [14C]citrulline from [14C]arginine. Addition of a 10% dilution of graft efflux to cultured rat macrophages incubated with LPS increased iNOS mRNA levels, suggesting direct inhibition of the enzyme but not of its expression. These results cannot be ascribed to the depletion of arginine the iNOS substrate since they can be reproduced even in the presence of an excess (10 mM) of exogenously added arginine. No correlation was found between the iNOS inhibitory activity in each sample and the corresponding clinical parameters related to either the graft function after the OLT or the existence of post-reperfusion syndrome. Our results indicate the existence of a soluble factor in the graft efflux from human OLT that reversibly and unspecifically inhibits NOS activity. Its involvement in the physiology and/or pathology of human liver diseases deserves further study.

[Tox-Didact:CD-ROM for toxicology education. Value in hospital toxicology]

New teaching techniques should allow students more independence in their training, particularly in learning from problems and using clinical reasoning. We designed Tox-Didact, a modular multimedia educational software program, which is suitable for both students and professionals, regardless of their orientation (pharmacy or medicine) or level. Each module concerns four domains: diagnosis, biological monitoring, curative treatment and prevention. Tox-Didact is multidisciplinary, interactive, simple to use and reliable. Nineteen modules are now being prepared. In final form, Tox-Didact will cover all the acute and chronic pathologies of toxicology.