Flow-cytometric cellular allergen stimulation test in latex allergy

BACKGROUND: The use of flow-cytometric basophil activation to different allergens has been recommended in recent years. In this study, we analyzed the diagnostic reliability of the flow-cytometric allergen stimulation test (FAST) after latex-specific stimulation in vitro. The diagnostic reliability of the technique was assessed as well as its correlation with other in vitro diagnostic parameters. METHODS: 43 patients allergic to latex with a positive history and skin test participated in the study. Thirty subjects (20 of them exposed to latex) with a negative history, skin tests and serum-specific IgE determination to latex were used as controls. In FAST the percentage of basophils that express CD63 as an activation marker after in vitro stimulation with allergen (latex) is determined by flow cytometry, following double labelling with the monoclonal antibodies anti-CD63-PE and anti-IgE FITC. RESULTS: Intraclass correlation coefficient in FAST with latex was 0.995 (p < 0.0001), which demonstrates the excellent reproducibility of this technique. Taking a cutoff point of 10% by means of ROC curves, FAST yields a sensitivity of 93% and a specificity of 100%. The FAST positive predictive value in latex allergy was 100% and the negative predictive value was 99.9%. We found a positive and significant correlation between FAST and specific IgE (CAP) with the histamine release test and specific sulphidoleukotriene production [cellular allergen stimulation test (CAST); p < 0.05]. CONCLUSIONS: FAST is a highly reliable technique (93% sensitivity and 100% specificity) in the in vitro diagnosis of IgE-mediated latex allergy.     

Synthesis and investigation of alpha-hydroxy-N,N-didesmethyltamoxifen as a proximate carcinogen in the metabolic activation of tamoxifen

Tamoxifen is an adjuvant chemotherapeutic agent for the treatment of breast cancer and a chemoprotective agent for breast cancer prevention. Despite being beneficial in regard to breast cancer, tamoxifen is known to increase the risk of endometrial cancer and thromboembolic events in women; in addition, it induces liver tumors in rats and endometrial tumors in rats and mice. Tamoxifen and its metabolite, N-desmethyltamoxifen, are metabolically activated to DNA binding electrophiles through alpha-hydroxylation, followed by O-esterification, primarily via sulfation. In the present study, we have investigated whether a second desmethylated metabolite of tamoxifen, N,N-didesmethyltamoxifen, is also involved in the metabolic activation of this antiestrogen to a genotoxic species. Alpha-hydroxy-N,N-didesmethyltamoxifen was synthesized, further activated by sulfation, and then reacted with DNA. After enzymatic hydrolysis to deoxynucleosides, HPLC analysis indicated the formation of one major DNA adduct, which was characterized as (E)-alpha-(deoxyguanosin-N(2)-yl)-N,N-didesmethyltamoxifen. Using (32)P-postlabeling, in combination with HPLC, the same adduct was detected in liver DNA from rats treated intraperitoneally with alpha-hydroxy-N,N-didesmethyltamoxifen. In contrast, only a low extent of adduct formation could be found in rats administered N,N-didesmethyltamoxifen. These data indicate that although alpha-hydroxy-N,N-didesmethyltamoxifen can be converted to a genotoxin in rat liver, this pathway is a minor one in the metabolic activation of tamoxifen.     

The Günther Tulip retrievable filter: prolonged temporary filtration by repositioning within the inferior vena cava

PURPOSE: To report experience with the retrievable Günther Tulip filter (GTF) as a means of temporary caval filtration for the prevention of pulmonary embolism (PE) with use of a technique that prolongs filter dwell time beyond 14 days. MATERIALS AND METHODS: Eighty-eight GTFs were implanted in 87 patients. The GTFs were placed with the intention of retrieval in all patients within 14 days after initial implantation. In 23 of the 87 patients (26%), there was a need to prolong temporary caval filtration beyond the recommended period of 14 days. This was successfully achieved with use of percutaneous techniques from the right internal jugular vein whereby the filter was repositioned to a different location within the inferior vena cava (IVC) before definitive device removal. RESULTS: Of 88 GTFs implanted in 87 patients, 70 were successfully retrieved and 18 were left in place permanently. Forty-seven filters in 46 patients were removed after initial implantation with no need for percutaneous repositioning within the IVC to prolong dwell time (mean dwell time, 13 days). In the 23 patients who required repositioning of 23 GTFs within the IVC to prolong temporary caval filtration, the mean dwell time was 34.8 days; the mean number of repositioning procedures was 1.5, the mean time between repositioning procedures was 13.8 days, and the mean fluoroscopy time was 4.4 minutes in patients in whom filter retrieval was attempted. One patient underwent placement and subsequent removal of the GTF twice for perioperative prophylaxis against PE on two separate occasions. No filters were misplaced in an unintended location or tilted (>15 degrees ) in relation to the main caval axis after deployment. In one patient, a GTF became permanently fixed in the IVC 16 days after initial implantation and could not be removed percutaneously. Nine patients had mild or moderate-sized cervical hematomas. One patient had recurrent asymptomatic PE 2 months after filter insertion. CONCLUSION: Dwell times of 14 days can be achieved in most patients before device removal. Prolongation of the dwell time beyond 14 days can be safely and easily achieved by performing percutaneous repositioning of the device within the IVC via a jugular approach.     

Percutaneous treatment of superior vena cava syndrome using metallic stents

The purpose of this study was to evaluate the results of treatment of superior vena cava syndrome (SVCS) in patients with benign and malignant disease using expandable metallic stent. From January 1995 to April 2000, 87 expandable stents were implanted in 82 patients (59 men, 23 women; mean age 57.8 years, age range 39–79 years) for the treatment of SVCS. The SVCS was defined as symptomatic bilateral obstruction of venous drainage from head, neck and upper extremities. In 68 patients SVCS was due to malignant neoplasia, and in 14 cases it was due to benign aetiology. All patients were treated with expandable stent. We implanted 81 Wallstent prostheses and 6 Palmaz stents. Adjuvant thrombolysis was applied in 12 patients who required fibrinolysis. After recanalization, the stent was implanted in all cases in SVC (infra- or supra-azygos vein). All patients were treated with heparin of low molecular weight (HBPM) during 6 months. Patency was analyzed according to clinical symptoms and Doppler US or venograms exploration. Technical success was observed in all cases. Clinical success was reached in 78 of 82 patients (95.1%) (absence of symptoms in 2 or 3 days). Four patients suffered immediate thrombosis which required fibrinolitic treatment with a new prosthesis placement in 1 case. The follow-up for the malignant process was of 7.1 months (range 1–39 months) and in benign cases was 31.2 months (range 11–61 months). Sixty-two (91.1%) patients with malignancy died without SVCS symptomatology. All the patients with benign pathology are alive. Clinical primary patency in malignant cases was 87% with assisted patency of 96.2%. Endovascular therapy using metallic stent and thrombolysis is a successful method to treat SVCS due to benign or malignant aetiology. Electronic Publication     

Two cases of severe sepsis successfully treated with activated protein C

A 64-year-old man and a 52-year-old woman in shock with multiple organ failure and worsening of sepsis related organ failure assessment SOFA scores in the early days of care were treated with recombinant human activated protein C (rhAPC). In the woman sepsis was associated with reversible heart failure, with decreased ejection fraction, biventricular dilatation, and a sharp increase of troponin I, observations that have been linked to a higher rate of multiorgan failure and higher mortality. The man began to improve after 24 hours and the woman after 48 hours of rhAPC treatment, with both continuing to improve after withdrawal of treatment. Severe sepsis remains a therapeutic challenge. Among the many treatments based on the physiopathology of the disease, so far only rhAPC seems to improve outcome and reduce mortality.     

Basophil activation test in the diagnosis of allergy to medicines

In this paper we study the reliability of the basophil activation test (BAT) in the "in-vitro" diagnosis of allergy to betalactams and to metamizol, and the sensitivity and specificity of the technique are analyzed. To this end, we studied 58 patients allergic to betalactam antibiotics with a positive cutaneous test facing any derivative of penicillin and 30 healthy controls who tolerated betalactams, and 26 patients allergic to metamizol with an immediate reaction and 30 healthy controls who tolerated the medicine. Sensitivity to BAT in allergy to betalactams was 52.8%, and specificity was 92.6%. For metamizol, sensitivity was 42.3% and specificity was 100%. The positive predictive value of BAT in allergy to betalactams was 18.9% and the negative predictive value was 98.4%. For metamizol, the positive predictive value of the technique was 100% and the negative predictive value was 99.4%. The joint use of BAT and CAP (specific IgE) makes it possible to diagnose some 65% of patients allergic to betalactams. The combined use of cutaneous tests and BAT in allergy to metamizol detects 70% of the cases. BAT is a useful, non-invasive technique in the "in-vitro" diagnosis of allergy to betalactams and metamizol.     

Medicinal plants from the Yanesha (Peru): Evaluation of the leishmanicidal and antimalarial activity of selected extracts

Aim of the study

Ninety-four ethanolic extracts of plants used medicinally by the Yanesha, an Amazonian Peruvian ethnic group, for affections related to leishmaniasis and malaria were screened in vitro against Leishmania amazonensis amastigotes and against a Plasmodium falciparum chloroquine resistant strain.

Materials and methods

The viability of Leishmania amazonensis amastigote stages was assessed by the reduction of tetrazolium salt (MTT) while the impact on Plasmodium falciparum was determined by measuring the incorporation of radio-labelled hypoxanthine.

Results and conclusions

Six plant species displayed good activity against Plasmodium falciparum chloroquine resistant strain (IC₅₀ < 10 μg/ml): a Monimiaceae, Siparuna aspera (Ruiz & Pavon), A. DC., two Zingiberaceae, Renealmia thyrsoidea (Ruiz & Pavon) Poepp. & Endl. and Renealmia alpinia (Rottb.), two Piperaceae (Piper aduncum L. and Piper sp.) and the leaves of Jacaranda copaia (Aubl.) D. Don (Bignoniaceae).Eight species displayed interesting leishmanicidal activities (IC₅₀ < 10 μg/ml): Carica papaya L. (Caricaceae), Piper dennisii Trel (Piperaceae), Hedychium coronarium J. König (Zingiberaceae), Cestrum racemosum Ruiz & Pav. (Solanaceae), Renealmia alpinia (Rottb.) Zingiberaceae, Lantana sp. (Verbenaceae), Hyptis lacustris A. St.-Hil. ex Benth. (Lamiaceae) and Calea montana Klat. (Asteraceae). Most of them are used against skin affections by Yanesha people.Results are discussed herein, according to the traditional use of the plants and compared with data obtained from the literature.