Occurrence Of Hypersensitivity Research Articles

Study on the interaction mechanism between Crocus sativus and Fusarium oxysporum based on dual RNA-seq.

The saffron phenylpropane synthesis pathway and Fusarium oxysporum cell wall-degrading enzymes play key roles in their early interactions. Saffron (Crocus sativus) is a highly important crop with diverse medicinal properties. F. oxysporum is a widely-distributed soil-borne fungus, causing the serious saffron rot disease. Currently, there is no effective management strategy to control this disease because of no resistant cultivars and limited information about the resistance and pathogenic mechanisms. In this study, we first characterized the infection process and physiological responses of saffron infected by F. oxysporum. The molecular mechanism of these infection interactions was revealed by dual RNA-seq analysis. On the 3rd day of infection, the hyphae completely entered, colonized and spread in the corm cells; while on the 6th day of infection, hyphae had appeared in the xylem cells, blocking these vessels. Transcriptome results indicate that within the host, phenylpropanoid metabolism, plant hormone signal transduction and plant pathogen interaction pathways were activated during infection. These pathways were conducive to the enhancement of cell wall, the occurrence of hypersensitivity, and the accumulation of various antibacterial proteins and phytoantitoxins. Meanwhile, in the fungus, many up-regulated genes were related to F. oxysporum cell wall degrading enzymes, toxin synthesis and pathogenicity gene, showing its strong pathogenicity. This study provides new ideas for the control of saffron corm rot, and also provides a theoretical basis for mining the key functional genes.

Pharmacotherapeutic study of efficacy, safety and prognostic analysis of anti snake venom serum in snake bite patients

Background: Snakebite is a common medical emergency especially in the rural areas. The effective measure to treat most of the manifestations of venomous snake bite is timely administration of anti-snake venom serum (ASVS). Problems associated with ASVS use are lack of evidence for optimal dose schedule and occurrence of hypersensitivity reactions.Methods: A retrospective review of snakebite cases was carried out from record section of a tertiary care teaching hospital from January 2011 to December 2011.Results: Out of total 202 snakebite patients admitted during the study period, age group of 21-30 years (mainly male victims) accounted for highest no. of snakebite cases (25.7%). The mean (±SD) dose of ASVS used was 124 (±112) mL. 11.8% patients had suffered from adverse drug reactions due to ASVS. 7.4% patients required mechanical ventilation. Overall mortality in our study was 9.4%. Mortality was higher (50%) where the time interval between the snakebite and initiation of treatment was >6 hours. Out of total 15 patients who required mechanical ventilation, n=10 (66.6%) patient died.Conclusions: In our study, mean dose of ASVS used was as per WHO guidelines. Less incidence of adverse drug reaction due to ASVS may be because of co-administration of corticosteroids and anti-histaminics. Delay in getting treatment with ASVS, neurotoxic envenomation and respiratory failure, were the risk factors associated with adverse prognosis due to snake bite in our set up.

Genome‐wide association study of nevirapine hypersensitivity in a malawian HIV‐infected population

The non-nucleoside reverse transcriptase inhibitor nevirapine is used in the treatment of HIV in many developing countries. Its use is associated with occurrence of hypersensitivity in 6-10% of patients. This hypersensitivity can manifest as a number of phenotypes which include the severe skin blistering reactions Stevens Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). The aim was to undertake a genome wide association study (GWAS) in order to identify genetic variants associated with predisposition to nevirapine-induced hypersensitivity. A total of 333 nevirapine-exposed (151 hypersensitive and 182 tolerant) , HIV-infected Malawian adults were genotyped for 826,551 genotyped SNPs using the Illumina HumanOmni1-Quad_v1 chip. A replication cohort of 62 hypersensitive and 59 tolerant patients from Malawi and Uganda was genotyped for 40 SNPs statistically significantly associated with a hypersensitive phenotype in the main cohort (p<5x10-5) using the Sequenom iPLEX platform or TaqMan allelic discrimination. Logistic regression analysis identified 40 statistically significant SNP signals associated with a nevirapine hypersensitivity phenotype. Only 1 SNP association signal (in the HLA-C locus, associated with SJS/TEN) was statistically significant in both our main discovery (=1.48x10-6) and enriched replication cohort (38 cases and 59 controls) (p=9.6x10-5). Meta-analysis determined the odds ratio as 5.17 (p=2.61x10-10). Data suggest this SNP to be a strong proxy for HLA-C*04:01 carriage (96% co-occurrence). We have confirmed that, in a sub-Saharan African population, HLA-C*04:01 carriage confers a significant risk for nevirapine-induced SJS_TEN though not to less severe hypersensitivity phenotypes. No other significant high penetrance genetic risk factors were identified.

Epstein – Barr Virus-Associated Extranodal NK/T-Cell Lymphoma following Mosquito Bites in an Elderly Patient without Prior Hypersensitivity

We describe a 73-year-old woman who developed fever and inflammation with ulceration at the site of mosquito bites in the lower thigh. Soon she developed disseminated skin lesions characterized by redness, induration, and local heat. Some lesions showed necrosis and ulceration, including those located in the nasal cavity. She had no history of hypersensitivity to mosquito bites, and the serum IgE concentration was within the reference range. A skin biopsy specimen from the lower thigh adjoining the mosquito bites was diagnosed pathologically as showing extranodal NK/T cell lymphoma, nasal type. Southern analysis of the biopsy specimen showed an oligoclonal band representing Epstein-Barr virus (EBV) DNA. Bone marrow examination revealed infiltration by lymphoma cells and marked hemophagocytosis. The patient underwent three cycles of chemotherapy with carboplatin, etoposide, ifosfamide, and dexamethasone (DeVIC), but died of lymphoma progression during treatment. We speculate that, rather than an allergic reaction, this late-life occurrence of hypersensitivity to mosquito bites might represent lymphoproliferative disease induced by a direct action of mosquito salivary gland secretions on EBV- infected NK cells.

Effects of cyclosporin A and glucocorticosteroids on antigen-induced hypersensitivity to histamine in a guinea pig model of allergic rhinitis.

In an attempt to study the pathogenesis of mucosal hypersensitivity in allergic rhinitis, we investigated the suppressive effects of cyclosporin A (CyA) and glucocorticosteroids on ovalbumin (OA)-induced hypersensitivity to topical histamine challenge. Actively sensitized Dunkin-Hartley guinea pigs. OA and alum were applied to guinea pigs intraperitoneally 3 times at two-week intervals. After general sensitization, OA inhalation was performed every day for 6 days as topical sensitization. Before inhalation, treatment with CyA (50 mg/kg, p.o.), glucocorticosteroids (beclomethasone propionate (1.0 mg/kg, i.p.), fluticasone propionate (FP, 0.5 mg/kg, i.p.)) or vehicle were performed, and the sensitivity to histamine was measured before and after the inhalation. Moreover, in actively (general and topical) sensitized guinea pigs, FP (0.5 mg/kg, i.p.) was applied every day for 5 days and histamine sensitivity was evaluated before and after the application. We found that histamine sensitivity was significantly increased by nasal antigen challenge in this guinea pig model, and that the occurrence of histamine hypersensitivity was inhibited by the pretreatment with CyA and glucocorticosteroids. Although multiple administration of FP gradually reduced the histamine hypersensitivity according to the period of administration, it did not significantly alter the histamine hypersensitivity after the occurrence of hypersensitivity. It is concluded that CyA and glucocorticosteroids suppress antigen-induced histamine hypersensitivity in a guinea pig model of allergic rhinitis.

Determination of methamphetamine and its metabolite amphetamine in biological fluids from 11 fatal cases

Gas chromatography with flame ionization detector (FID) along with mass spectrometry (GC/MS) were used for the screening and quantification of methamphetamine (MA) and its major metabolite, amphetamine (AM), in blood and urine in eleven fatal cases in which MA abuse was suspected. Postmortem blood MA varied from 0.5–30.2 μg/ml, while AM levels ranged from none detected (6 of 11 cases) to 4.8 μg/ml. Additionally, distribution studies were performed in three of these cases in which tissue samples were available for evaluation. Liver contained the highest concentration of MA among the tissue samples. In eight of the eleven cases, when no other direct cause of death was evident (i.e. 3 cases of traumatic death), either no blood AM was found or the ratio of MA/AM was 3.4 or greater. These data are consistent with acute MA use followed by death due to acute drug intoxication or by the occurrence of hypersensitivity and reverse tolerance seen in cases of chronic drug abuse.

Hypersensitivity to antimuscarinic agents following brief exposure to Soman and Sarin.

Behavioral responses to atropine in rats exposed to the potent anticholinesterase agents Soman and Sarin were studied. Atropine itself produced limb-shakes and certain stereotyped activities, in a dose-dependent manner. The neurotoxicity elicited by Soman and Sarin was antagonized by atropine, while at the same time the responses induced by the latter were attenuated. In contrast, where rats were challenged with atropine 6-72 h after giving single doses of Soman or Sarin, the limb-shake myoclonus was markedly enhanced. The atropine-induced stereotypies were not, however, significantly affected, except for an increase seen at 24 h after Sarin treatment. Repeated treatment with Soman for 3 wk also led to similar supersensitivity of atropine-induced responses. The peripheral muscarinic receptor antagonist, methylatropine, produced no such hyperactivity on its own or at any time after anticholinesterase exposure. The rapid occurrence of hypersensitivity to antimuscarinic compounds following exposure to these anticholinesterases, therefore, suggests the need for observation of subjects who are poisoned with such agents and treated with antimuscarinics, for adverse reactions such as myoclonus during the critically sensitive period, especially if repeated antimuscarinic therapy is carried out.

The effects of light and a photosynthetic inhibitor on the expression of the Lr20 gene for resistance to leaf rust in wheat

A possible relationship between photosynthetic activity and the occurrence of hypersensitivity was explored. Most of these experiments exploited the temperature-sensitivity of the Lr20 gene which is expressed at 20 °C but not at 30 °C. Colonies of avirulent rust were thereby grown at 30 °C before transfer to 20 °C where necrosis and limitation of fungal growth occurred under normal conditions. Necrosis was largely prevented in leaves held under coloured cellophanes which filtered out photosynthetically active wavelengths of light. Necrosis was also prevented by application of 3-(3,4-dichlorophenyl)-l,l-dimethylurea (DCMU). Despite the prevention of necrosis by DCMU, the avirulent rust grew very litde in the presence of the Lr20 gene. These results suggested that photosynthesis is involved in processes leading to necrosis in this system and showed that necrosis is not essential for expression of resistance to rust growth.

Therapy of Bacterial Endocarditis in Penicillin-Hypersensitive Patients

THE PRESENT methods of treatment of subacute bacterial endocarditis due to α- or γ-streptococci in penicillin-hypersensitive patients are the following: penicillin given cautiously in the hope that the history is in error or that there will not be a repeat occurrence of hypersensitivity; cortisone or one of its derivatives given concurrently with penicillin; desensitization to penicillin; ristocetin or cephalothin given instead of penicillin. 1-4 The two cases detailed below suggest that therapy with the combination of lincomycin and streptomycin is another method of therapy for use in penicillinhypersensitive patients who have endocarditis due to α- or γ-streptococci. 5-6 Report of Cases Case 1. —The patient was a 55-year-old white man admitted to Mount Sinai Hospital on Dec 20, 1965, because of chills and fever of one month's duration. He had been known to have rheumatic heart disease with mitral insufficiency since 1953 and had been taking digitalis since 1955. Pertinent