Its principle formulation ingredients is also explicitly very wel

Its principle formulation ingredients is also explicitly very well described in Ayurvedic formulatory of India. 20 In addition, comparative organoleptic analysis ash value, macroscopic properties, 25Ayurvedic in-house formulation standardization and pharmacognostic characters of selleckchem Sitopaladi Churna 26 was

also established. However, to meet pharmaceutical demands, validation is needed for identification, purity, stability data and scientific based evidence about efficacy of Sitopaladi Churna formulations to produce results which are reliable, accurate and reproducible. UV-spectrophotometric fingerprint method developed has been developed for simultaneous estimation of phytochemical piperine from Sitopaladi Churna. 24 The method described in this paper was completely validated for estimation of eugenol from commercial this website ayurvedic formulation like Sitopaladi Churna and thus can be extended in routine quality control analysis to check batch to batch variation for drug approval. However, UV method reported, poses various issues like inadequate sensitivity and narrow dynamic linear range. Thus, this method proves very challenging to be reliable for quantitative and semi

quantitative analysis for separation of main active ingredients (markers compounds) present in Ayurvedic formulations. Due to strong UV absorbance involved in UV spectrophotometers, the preservatives, polymetric matrices, cross interference with other active components, detector saturation with polysorbate solutions are potential sources of interference in producing reliable data for direct spectrophotometric analysis. Hence, further research was needed to validate and produce reliable results which can be stretched to set quality specifications for composition and concentration of phytoconstituents tuclazepam in herbal medicines. We present completely new experimental analytical validated RP-HPLC method with properly selected Column like C18, mobile phase concentration (60:40) methanol: distilled water

and detector set at 215 nm for quantification of eugenol from Sitopaladi Churna with reliable and reproducible results. Therefore, with increasing emphasis on reliable product quality control requirements for drug formulation and standardization, proposed RP-HPLC method developed and validated in this paper can be successfully exploited for successfully quantifying even low sample concentrations of eugenol from Sitopaladi Churna. This method also confirms reliable separation and quantification of analytes of interest without interference from excipients, preservatives and dissolution media respectively ( Fig. 4E). Enteric bacterial species like Salmonella sp and S. aureus are a major infectious agents contributing to health problems like diarrhoeal infections in developing countries and are primarily responsible for mortality around 6 million children annually.

Demographics of those in Group A (n = 9) and Group B (n


Demographics of those in Group A (n = 9) and Group B (n

= 7) are summarised in Table 1. Five main themes were identified within focus group data from both Group A and B and are shown in Box 2. The themes and subthemes were consistent between groups and are presented in Box 2, with example statements from participants to illustrate the theme. Additional participant statements are provided in Appendix 1 to further justify the themes and subthemes (see the eAddenda for Apoptosis Compound Library Appendix 1). Value of pulmonary rehabilitation • education and knowledge Ongoing exercise • routine Professional support • confidence Peer social support • fellowship Health status Pulmonary rehabilitation was viewed as highly beneficial by participants, having experienced for themselves the positive impact of regular exercise on their daily lives. I got up those stairs without collapsing at this website the top and feeling so out of breath. That’s when

I realised … it was working, it was going to help me to get around more comfortably … so that encouraged me more to do the exercises. Education and knowledge: Improved knowledge and understanding of symptom management facilitated greater control over breathlessness. Enhanced understanding of the benefits of regular activity as part of disease management prompted increased participation. [I learnt] how to stand and get your breath back. I do that now if I get really breathless … I used to panic before and now I do that and it helps. Confidence to be active: Pulmonary rehabilitation reduced

fear and anxiety associated with exertional activity, enabling and motivating participants to do more than they would otherwise have done. The experience of exerting themselves in the pulmonary rehabilitation class without ill effect boosted their confidence – or self-efficacy – to be more active. Before I did pulmonary rehab, if I wanted to go out, I would think no … maybe I won’t go because I’m feeling a bit breathless today but [now] I don’t have to worry about going places that I want to go. Participants in both groups were keen to maintain their newfound level of ability and expressed a desire for continuation of pulmonary rehabilitation. Putting in a nutshell, this second is what we’re all talking about, we would like the classes to carry on. When regular exercise ceased, either through temporary inability to attend maintenance in Group A or following pulmonary rehabilitation in Group B, deterioration in physical ability and symptoms was commonly experienced. The confidence and motivation to be physically active initially gained during the course tended to diminish thereafter. I was forever getting on buses, but after four weeks going to pulmonary class, I was walking there! I would have put money on it that I wouldn’t have been able to do it … then after packing up, the buses looked attractive.

18, 19 and 25 Results indicated that the incubation of macrophage

18, 19 and 25 Results indicated that the incubation of macrophages with compounds 5 and 4 resulted in a highly significant increase (P < 0.05) in the cells proliferation at the highest tested dose and that this dose-dependent increase started from the lower tested dose and reached 1.63- and 1.42- fold of the control, respectively, at the highest tested dose, indicating immunomodulatory activity. 11 Treatment of macrophages with the extract and compound 11 showed a non-significant

increase (P > 0.05) in the macrophage proliferation at any of the tested dose ( Fig. 3). Results of the anti-inflammatory activity of the Epigenetics Compound Library cost tested samples (80% MeOH leaf extract, compounds 4, 5 and 11), evaluated by Griess assay showed inhibitory effect on NO generation in the supernatant of lipopolysaccharide (LPS) – stimulated RAW 264.7 macrophage cells as the following order: compound 4 > 5> extract >11 as indicated from the inhibition percentages: 68.19%, 52.95%, 20.33%, and 15.22%, respectively, where quercetin-3-O-arabinoglucoside (compound 4) was the most effective inhibitor of LPS-induced ATR inhibition NO generation (P < 0.01), implying enhanced anti-inflammatory activity 26 ( Fig. 4). Results showed that the tested

samples revealed an inhibitory effect on TNF-α secretion to a variable extent, as the following order: compound 4 > 5 >extract > 11 as indicated from

the inhibition percentages: 70.82%, 29.88%, 13.13%, and 6.14%, respectively, (P < 0.01), where quercetin-3-O-arabinoglucoside (compound 4) was the most effective inhibitor indicating anti-inflammatory activity 15 ( Fig. 5). Results Liothyronine Sodium indicated that the treatment of Hep-G2, MCF-7 and HCT-116 cells with the different tested samples was safe and possessed a non cytotoxic effect against different cell types with IC50 values >50 μg/ml,8 except for compound 11, which was cytotoxic only against HCT-116 cells, as indicated in the dose response curve (Fig. 6) and the low IC50 value of 27.67 μg/ml. The 80% MeOH leaf extract, was evaluated for antibacterial activity using Ciprofloxacin, broad spectrum antibiotic as a positive control and 80% methanol solvent as a negative control, results showed that the leaf extract had significant effect against S. aurous, S. pyogenes, E. coli, P. aeruginosa, K. pneumonia and P. mirabilis with inhibition zone Ø values of 18, 20, 15, 20, 15 and 17 mm, respectively. Moreover it inhibits the growth of K. pneumonia strain which is a sensitive strain resistant to Ciprofloxacin antibiotic. In conclusion, the methanol leaf extract of R.

There were 1545 participants (5 3%) with a reduced eGFR (50–59 9 

There were 1545 participants (5.3%) with a reduced eGFR (50–59.9 ml/min/1.73 m2: n = 1416, 45–49.9 ml/min/1.73 m2: n = 118, < 45 ml/min/1.73 m2: n = 11). The reduced eGFR group was associated with an older

age and higher risk Adriamycin cell line profile of traditional cardiovascular risk factors. During a mean follow-up period of 9.3 years (271,383 person-years), 43.9% of the cohort (12,818 participants) developed hypertension. The number of incident hypertension cases determined by the use of antihypertensive drugs was 2.2% (292 participants) of all incident hypertension cases. The cumulative incidence of hypertension was higher in the positive proteinuria group than in the negative proteinuria group in a Kaplan–Meier analysis (negative: 43.6%; trace: 54.2%; ≥ 1 +: 61.0% in 10 years; log-rank test, p < 0.001) (Fig. 1A). Similarly, the cumulative incidence of hypertension was higher in the reduced eGFR group than

in the preserved eGFR group (≥ 60 ml/min/1.73 m2: 43.4%; 50–59.9 ml/min/1.73 m2: 52.9%; < 50 ml/min/1.73 m2: 62.8% in 10 years; log-rank test, p < 0.001) (Fig. 1B). The median duration since test of proteinuria/reduced eGFR was 5 (2–10) years, and that of reduced eGFR 5 (2–10) years. The association between the two positive proteinuria categories (trace and ≥ 1 +) and incident hypertension remained significant even after adjusting for age (Table 2). Further adjustment for other potential confounders attenuated the associations; however, the association for proteinuria ≥ 1 + remained significant, even in model 5, which second included eGFR (adjusted HR 1.19 [95% CI, 1.06 to 1.34], p < 0.001). Notably, when we compared positive vs. negative proteinuria, the adjusted HR was statistically significant, even in model 5 (1.14 [95% CI, 1.03 to 1.26], p < 0.001). On the other hand, the association between a reduced eGFR (≥ 60 ml/min/1.73 m2) and incident hypertension was more substantially attenuated by the adjustment for age. However, a significant association was observed for an eGFR of < 50 ml/min/1.73 m2 only

(vs. ≥ 60 ml/min/1.73 m2) after further adjustment (1.29 [95% CI, 1.03 to 1.61] in model 5, p < 0.001). We did not observe any significant associations between a reduced eGFR (< 60 ml/min/1.73 m2) and incident hypertension in models 3–5 (HR 1.02 [0.95–1.10] in model 3). We further evaluated the association between positive proteinuria (vs. negative proteinuria) and incident hypertension in several subgroup analyses divided by the following parameters: baseline BP, age, BMI, diabetes mellitus, dyslipidemia, current smoking and current alcohol intake. Positive associations between positive proteinuria and incident hypertension were observed in several of the subgroups tested, with few significant interactions. Of importance, the HR was significant among individuals with an optimal BP at baseline (< 120/80 mm Hg) (adjusted HR 1.31 [95% CI, 1.10 to 1.

RPE cells produce and secrete their own complement inhibitors, su

RPE cells produce and secrete their own complement inhibitors, such as complement factor H, complement factor I, membrane cofactor protein, vitronectin, and clusterin.11, 42, 43, 44, 45 and 46 The production of these complement inhibitors is upregulated in patients with AMD.42 Selleck Bcl-2 inhibitor Furthermore, vitronectin and membrane cofactor protein are upregulated in the RPE cells that flank or overlie drusen.11 and 42 This production of complement inhibitors by ocular tissues, like the RPE cell, plays an important role not only in protecting the eye against complement-mediated damage but also in maintaining the immune-privileged state of the eye.47 Disturbance of the aforementioned factors

that induce and sustain chronic local inflammation at the level of the RPE–Bruch membrane interface, and those that attenuate it, can explain the association of a decreased reflectivity of the overlying RPE and concomitant photoreceptor layer with drusen regression. A loss of RPE cells will result in a decreased generation of extracellular debris that makes up a druse, whereas macrophage recruitment

and the upregulation of complement inhibitors by RPE cells flanking the druse will start a process of druse volume regression. It is this process of drusen remodeling that points to a high biochemical activity and suggests that future treatments targeting these biochemical processes in an early stage of the disease may have a significant role in prophylactic and therapeutic interventions in basal laminar drusen. The Paclitaxel supplier finding that drusen progression and drusen regression occurred in all the study eyes within a very short period may have implications for clinical studies on patients with basal laminar drusen. Because number and size of drusen are important for disease staging, longitudinal changes in drusen morphology can be a potential all source of misclassification and needs attention in epidemiologic studies investigating the natural history of basal laminar drusen as well in clinical trials evaluating the efficacy of possible therapies. Our study has some limitations. First

of all, the limited number of eyes restricts the general use of our data. However, because drusen remodeling was observed in all study eyes, those changes are very likely to occur commonly in eyes with basal laminar drusen. Secondly, slight variations of SD-OCT scan positions during follow-up visits cannot be excluded. However, eye movements were automatically registered and corrected for “eye tracking,” resulting in high repeatability and reproducibility of the SD-OCT scans; therefore, small shifts of only a few microns could have influenced the appearance of these very small drusen in basal laminar drusen.29 and 32 On the other hand, it is unlikely that random shifts may lead to nonrandom, continuous changes during the study period.

To differentiate monocytes into immature DCs 250 U/ml granulocyte

To differentiate monocytes into immature DCs 250 U/ml granulocyte macrophage-colony stimulating factor (GM-CSF) and 100 U/ml IL-4 (Invitrogen) was IOX1 clinical trial added. Medium was refreshed after 3 days. DC were incubated for 48 h at 37 °C in RPMI 1640 containing 500 U/ml GM-CSF with OVA (highest

concentration 5 μg/ml), either free or encapsulated into liposomes with and without PAM or CpG (highest concentration 10 μg/ml), keeping the lipid:OVA:TLR ligand ratio 50:2:1 (w/w). OVA, OVA liposomes and mixtures of OVA with PAM or OVA with CpG were used as controls and LPS (100 ng/ml, Invivogen) was added as a positive control. Cells were washed 3 times with PBS containing 1% (w/v) bovine serum albumin and 2% (v/v) FCS and incubated for 30 min with a mixture of 20× diluted anti-HLADR-FITC, anti-CD83-PE and anti-CD86-APC (Becton Dickinson) in the dark at 4 °C. Cells were washed and the expression of MHCII, CD83 and CD86 was quantified using flow cytometry (FACSCanto II, Becton Dickinson) relative to LPS, assuming 100% maturation for LPS-treated DC. Live cells were gated based on forward and side scatter. Groups of 8 mice were immunised with the OVA-loaded liposomes with and without PAM or CpG by ID injection into the abdominal skin as described

previously [30]. Besides the liposomes, solutions of OVA or OVA with PAM or CpG in PBS were injected and subcutaneous (SC) injection of OVA served as a control. The mice were vaccinated twice with three weeks intervals

with a dose of 5 μg learn more OVA and 10 μg PAM or CpG in a total volume of 30 μl. To maintain this either ratio between antigen and immune potentiator, liposomes used for the immunisation study were not filtered to remove free antigen and TLR ligand. Blood samples were collected from the tail vein 1 day before each immunisation. Three weeks after the last vaccination the mice were sacrificed. Just before euthanasia total blood was collected from the femoral artery. Afterwards the spleens were removed. Blood samples were collected in MiniCollect® tubes (Greiner Bio-one, Alphen a/d Rijn, The Netherlands) till clot formation and centrifuged 10 min at 10,000 × g to obtain cell-free sera. The sera were stored at −80 °C until further use. OVA specific antibodies (IgG, IgG1 and IgG2a) in the sera were determined by sandwich ELISA as described previously [30]. Briefly, plates were coated overnight with 100 ng OVA/well. After blocking, two-fold serial dilutions of sera from individual mice were applied to the plates. HRP-conjugated antibodies against IgG, IgG1 or IgG2a were added and detected by TMB. Antibody titres were expressed as the reciprocal of the sample dilution that corresponds to half of the maximum absorbance at 450 nm of a complete s-shaped absorbance-log dilution curve.

Using Hypurity C18 column poor chromatography

Using Hypurity C18 column poor chromatography click here was observed. Good response was observed with waters Atlantis, HILIC, 50 × 2.1 mm, 3 μm, was selected as the analytical column connected with Guard column Waters Atlantis, HILIC, 10 × 2.1 mm, 3 μm. It gave satisfactory peak shapes for both Acamprosate and Acamprosate

D12. Flow rate of 0.25 mL/min without splitter was utilized and reduced the run time to 3.0 min. Both Drug and IS were eluted with shorter time at 2.1 min. For an LC-MS/MS analysis, utilization of stable isotope-labeled or suitable analog drugs as an internal standard proves helpful when a significant matrix effect is possible. In our case, Acamprosate D12 was found to be best for the present purpose. The column temperature was adjusted to 40 °C. Injection volume of 20 μL sample is adjusted for better ionization and chromatography. During extraction stage different extraction procedures like PPT (protein precipitation), LLE (liquid–liquid extraction), and SPE (solid phase extraction). We found ion suppression effect in protein precipitation method for drug and internal standard. Further, we tried with SPE and LLE. Out of all, we observed that SPE is suitable for extraction LGK-974 nmr of drug and IS. Autosampler wash is optimized as 80% methanol. Several compounds were investigated to find a suitable IS, and finally Acamprosate D12 found the most

appropriate internal standard for the present purpose. There was no significant effect of IS on analyte recovery, sensitivity Linifanib (ABT-869) or ion suppression. High recovery and selectivity was observed in the solid phase extraction method. These optimized detection parameters, chromatographic conditions and extraction procedure resulted in reduced analysis time with accurate and precise detection of Acamprosate in human plasma. A thorough and complete method validation of Acamprosate in human plasma was done following USFDA guidelines.13 The method was validated for selectivity, sensitivity, matrix effect, linearity,

precision and accuracy, recovery, dilution integrity, reinjection reproducibility and stability. There is no interference observed for Acamprosate and Acamprosate D12 at their retention time in blank plasma (Fig. 4) and LOQ (Fig. 5). These interferences are within the acceptance criteria for all six lots of blank samples. The LLOQ for Acamprosate was 1.00 ng/mL. The intra-run, inter-run precision and accuracy of the LLOQ plasma samples containing Acamprosate was 3.56 and 102.00% and 2.0 and 102.21%, respectively. All the values obtained below 1.00 ng/mL for Acamprosate were excluded from statistical analysis as they were below the LLOQ values validated for Acamprosate. The CV % of ion suppression/enhancement in the signal was found to be 1.0% at MQC level for Acamprosate indicating that the matrix effect on the ionization of analyte is within the acceptable range under these conditions.

The stressors, choice of their

concentration and preparat

The stressors, choice of their

concentration and preparation of samples were based selleck kinase inhibitor on guidelines in the publication.12 As the drug was insoluble in water, it was dissolved in a mixture of acetonitrile and water in a ratio of 50:50 (v/v) to a final concentration of 2 mg/ml. The stock was diluted 50:50 (v/v) with the stressor (e.g. HCl, NaOH, H2O2 and water etc.). Hydrolytic decomposition of the drug was carried out in 0.2 N HCl and 0.2 N NaOH at 80 °C for 24 h and in water, refluxing at 80 °C for 4 days. The oxidative study was carried out in 30% (v/v) H2O2 at room temperature for 9 h. For thermal stress testing, the drug was sealed in glass vials and placed in a thermostatic block at 50 °C for 21 days. Photolytic studies on the drug in the solution state were carried out in 0.01 N HCl, water, and 0.01 N NaOH by exposing it for 14 days to a combination of Fluorescent and UV light in a photostability chamber at 1.2 million lx and 200 W/m2, respectively. Parallel set was kept in dark for 14 days. Photolytic studies in the solid state were performed by exposing a thin layer of the drug to light under similar condition as that of solution state. The stressed samples of acid and alkali hydrolysis were neutralized with NaOH

and HCl, respectively to obtain 500 μg/ml solutions. Neutral hydrolysis, thermal and photolytic samples were diluted with mobile phase to obtain 500 μg/ml solutions. The oxidative stress sample was diluted with mobile phase composed of methanol and ammonium formate buffer (pH 4.0; 0.01 M) GDC-0973 cell line (50:50, v/v) to obtain 100 μg/ml solution. All the prepared samples were passed through 0.45 μm membrane filter before HPLC and LC–MS analysis. The stressed solutions, in which sufficient amounts of products were formed, were combined in equal proportions

to prepare a mixture containing all degradation products in one solution. This mixture was subjected initially to LC–PDA and further to LC–MS analyses for characterization of degradation products. During the optimization Bay 11-7085 process, preliminary studies were carried out on Hypersil Gold C-18 column (4.6 × 250 mm, 5 μm) using water: methanol (90:10, v/v) as a mobile phase. Initial separation studies were carried out on samples of different stress conditions individually and later on resolution of drug and degradation products was studied in a mixture of those stressed samples, where different degradation products were observed. The peaks corresponding to degradation products did not resolve completely and tailing was noticed. To get acceptable separation between the drug and its degradation products, ammonium formate buffer (0.01 M) was used instead of water. The pH of the buffer, flow rate and composition of the mobile phase were systematically varied to optimize the method.

This is accomplished by increasing the concentration of acetylcho

This is accomplished by increasing the concentration of acetylcholine through reversible inhibition of its hydrolysis by acetylcholinesterase. The recommended

initial dose of donepezil is 5 mg taken once daily. Donepezil is well absorbed with a relative oral bioavailability of 100% and reaches peak plasma concentrations (Cmax) approximately 3–4 h Cabozantinib purchase after dose administration. In humans, donepezil is metabolized mainly by the hepatic cytochrome P-450 2D6 and 3A4 isozymes. 2 Elimination of donepezil from the blood is characterized by a dose independent elimination half-life of about 70 h. 3 and 4 Because plasma donepezil concentrations are related linearly to acetylcholinesterase inhibition, 5 plasma donepezil concentration is a useful tool to predict donepezil efficacy. In the literature, methods have been reported for the quantification of donepezil in biological fluids. Methods are reported for the quantification of donepezil from biological

matrix using high-performance liquid chromatography (HPLC) equipped with an ultraviolet detector,2 and 3 fluorescence detector4 and mass spectrometric1, 6 and 7 detector. Methods are also reported for the quantification of enantiomers of donepezil from human plasma.8, 9 and 10 Other methods are reported with estimation of donepezil in plasma by capillary electrophoresis,11 hydrophilic interaction chromatography-tandem mass spectrometry,12 direct measurement,13 automated most extraction.14 The HPLC methods used to determine donepezil in human plasma are insensitive because

of the lower limit of quantification (LOQ of >1.0 ng/ml). Some of the click here reported methods1, 4, 6, 10, 13 and 14 utilized analogue internal standards like diphenhydramine, lidocaine, pindolol, loratadine, escitalopram, etc. and are validated with different calibration curve ranges for the estimation of donepezil from rat plasma, human plasma and other biological fluids. Usage of labelled internal standards is recommended during the estimation of compounds from the biological matrices to minimize the matrix effects associated with the mass spectrometric detection. Bioequivalence and/or pharmacokinetic studies become an integral part of generic drug applications and a simple, sensitive, reproducible validated bioanalytical method should be used for the quantification of intended analyte. Bioequivalence studies for the donepezil needs to be performed with the dosage of 10 mg and 23 mg tablets to support the generic abbreviated new drug applications. For the pharmacokinetic and bioequivalence studies, quantification of donepezil was sufficient and quantification of its metabolites shall not be required. During the bioequivalence studies, appropriate lower limit of quantification needs to be used to appropriately characterize the concentration profile including the elimination phase.

For this BLASTP, is opened from the DEG home page and the probabl

For this BLASTP, is opened from the DEG home page and the probable selleck chemical proteins were isolated from the above step are entered in the FASTA format as the query sequence with the default parameters. All the genes having similarity with Mycoplasma genitalium were selected. The selected genes were then subjected to BLASTP again with the human genome. This is necessary to remove any protein present in common to human and bacteria proteome because as targeting that very

protein may have adverse effect on humans. This may be side-effects such as some allergic reactions or toxic effects. In the study, all the virulent genes were extracted from the Virulent Factor Database which was 21 in number.17 and 18 To predict new virulent genes the available microarray data was retrieved from Stanford Microarray Database. These

genes were subjected to clustering which helped in identifying many more genes that co-expressed along with the virulent genes that were isolated from VFDB. According to the cluster theory all the co-expressed genes are grouped in same cluster. Clustering resulted in the formation of 450 clusters out of which 21 clusters were selected in which already known virulent Selleck Entinostat genes were found. Some genes were found in more than one cluster from which we can infer that a large number of genes are being expressed at the same time as the corresponding gene might have one of the vital roles in the survival of bacteria. To identify the paralogous genes, above genes were subjected to BLAST2. Since gene duplication is a rare phenomenon, none such gene was identified for S. pneumoniae. Target proteins should be essential to the concerned pathogenic bacteria, i.e., any disruption in the functioning of those Oxalosuccinic acid genes will lead to bacterial death. To identify the essential proteins, all the proteins were subjected to BLASTP against DEG. The proteins that were showing a hit of more than 90 and e-value taken as 0.1 was selected as essential genes. Only 50 were able to fulfill this requirement. Fewer hits depicted that only few proteins of the genes that co-expressed along with the virulent factor reported are essential for the survival

of the bacteria. As we know that the host of S. pneumoniae is human so it is essential to check the hits of the same with the Homo sapiens and Escherichia coli (gut flora). The proteins similar to host proteome are to be checked for the prevention of further dead ends. In case of any similarity, it can hamper the hosts’ survival (because if the drug developed against any gene present in bacteria shows similarity to host then it can disturb the normal functioning of the host genome). The reason of similarity is the horizontal and vertical gene transfer during the course of evolution. Proteins showing sequence similarity with any human protein may lead to drug reactions with the host that can be responsible for toxic effects.