Highest Number Of Positive Reactions Research Articles

Evaluation of the effectiveness of ultrafast urease tests in the diagnosis of Helicobacter pylori-associated gastritis in children

Background: Helicobacter pylori (H. pylori) is one of the main causes of gastritis, peptic ulcer and stomach cancer. Ultrafast urease tests (UUT) make it possible to simplify patient management by notifying the result after 5 minutes and entering it into the protocol of endoscopic conclusion. There is no data on the accuracy of UUT in the pediatric population. Aim of the study: to identify the accuracy of UUT in comparison with histological examination in children. Methods: a single-center retrospective study of children (4-18 years old) who underwent esophagogastroduodenoscopy with biopsy of the gastric antrum mucosa for H.pylori UUT, followed by histological examination. The reaction time stated by the manufacturers was estimated to be no more than 5 minutes for a positive result. Histology was the “gold” standard. Results: 211 patients were examined (boys n=103, 48.8%; girls n=108, 51.2%) average age 11.7 years (±3.5, 4-18 years). H.pylori infection was detected in 31 out of 211 patients. There was a significantly higher number of positive reactions of both UUT’s in the age group of children from 11 to 18 years old compared with the group of children from 4 to 10 years old. The sensitivity of AMA RUT Pro UUT was 18.7%, specificity 93.8%, negative and positive predictive value 82% and 42%, respectively, accuracy 79%. The sensitivity of the BioHit UFT300 UFUT was 40%, specificity 96.5%, negative and positive predictive value 92% and 60%, respectively, accuracy 90%. Conclusion: our data demonstrate the low sensitivity of ultrafast urease tests in children when using a single fragment of tissue from the gastric antrum in the five-minute reaction time allotted by manufacturers to a negative result. Perhaps sensitivity indicators can be improved by placing several fragments of the mucous membrane of the body and the antrum of the stomach on one test, which is a direction for future research.

The occurrence of Leptospira spp. serogroup Pomona infections in wild boars

Leptospirosis is a worldwide zoonosis caused by different pathogenic serovars of the genus Leptospira, with very complex aetiology and epidemiology. Recent publications suggest that wild boar (Sus scrofa) has an important role in the epizootiology of leptospirosis, representing a potential source of infection. Wild boar populations in urban environments are increasing, posing not only agricultural and ecosystem concerns, but also a public health concern. The aim of this study was to assess the prevalence, temporal patterns and risk factors of Pomona infection in wild boars from areas with pronounced human activity. A total of 159 wild boar serum samples were collected within a health monitoring project in Medvednica Nature Park over a period of six hunting seasons (2012–2016; 2018) and 25.2% samples tested positive. Seropositivity against seven different serogroups was observed, with the highest number of positive reactions to the serogroup Pomona. Annual variation in Pomona reactivity was also detected, and positive reactions were five times more common in females than in males. In most of studies, adults had a higher seroprevalence than younger categories; however, in this study,seroprevalence against Pomona was higher in piglets and subadults. The results indicate that wild boar has the potential of maintaining serovars from the serogroup Pomona in certain natural foci. Due to the expansion of wild boar populations and their intrusion into urban areas, they should be considered a potentially important source of infection for humans and domestic animals.

Seroprevalence of pathogenic Leptospira serovars in hunting dog in Bosnia and Herzegovina

Leptospirosis is an acute, subacute and chronical contagious disease of animals and humans. Causative agents of this disease belong to the genus Leptospira, family Leptospiraca. As a disease of wild animals, leptospirosis is widespread through Europe. Certain wild animals (rodents, fox and wild boars) are important reservoirs and highly probable vectors for the spread of infection into domestic animals and humans. During the hunting season, hunting dogs are often in direct or indirect contact with wild animals that could be carriers of this disease, and the possibility of appearance and spreading within this cohort of dogs is very high. The main reasons for this study on the prevalence of Leptospirosis in Bosnia and Herzegovina are the regular contact between hunting dogs and wild animals (carriers), and the lack of dataaboutLeptospirosisinhuntingdogs.In total, 175 serum samples from 15 towns of Bosnia and Herzegovina were tested. Twelve serovars of L. interrogans were used in the microscopic agglutination test. Presence of antibodies of four serovars was confirmed. Prevalence of seropositive dogs was 15.4% (27/175). Most positive dogs had a reaction to the Pomona serovar 51.8% (n=14), while the prevalence of the Sejroe serovar was 33.3%, Icterohaemorrhagiae serovar 11.1% and Bratislava serovar 3.7%. The highest number of positive reactions 55.5% (n=15) was with serum dilution of 1:200. This study showed that most infections in dogs were caused by serovars that are currently not included in commercial vaccines. One of the most efficient preventive measure could be vaccination with the serovars most often found in wild animals, as they appear to be the most common source of the infection.

Common allergens causing Naso bronchial allergy in patients attending a tertiary care centre in South India

Introduction: Patients who seek medical care because of the symptoms of naso bronchial allergies are increasing. The distribution of allergens and its effect on the population differs in different parts of India. For the management and effective treatment of allergen induced respiratory illnesses, it is very important to find out the specific allergens responsible. To determine the common allergens causing naso-bronchial allergy in atopic patients. Materials and Methods: Atopic patients who attended a tertiary care centre as outpatients for an year with symptoms of naso-bronchial allergy for more than a year who were not responding to regular medications were selected for the study after taking a detailed history. An intradermal allergy test was done in the volar aspect of the patients arm and forearm with antigens of the common allergens prevalent in south India. Results: Out of 51patients tested by 39 allergens, 47 persons turned positive for at least one antigen. Among pollen antigens, Acacia species showed highest number of positive reactions. Among dust, house dust and wheat dust showed higher positivity. Among antigens of animal origin, house fly was highest and among fungal origin, Aspergillus fumigatius showed high positivity. Conclusion: The commonest antigen identified was that of house dust followed by house fly.

Susceptibility among breeds of sheep experimentally infected with Leptospira interrogans Pomona serogroup

Leptospirosis is a disease that negatively affects the productive and reproductive indices of ruminants. Sheep are considered highly resistant to infection, although susceptibility may vary among breeds. Thus, the aim of the present study was to analyze the susceptibility between sheep breeds to the experimental infection by leptospires of the Pomona serogroup. Pomona serogroup, Kennewicki serovar strain (1 × 107 bacteria) was inoculated via the conjunctival route in 12 sheep divided into two groups, one comprising Santa Inês ewes and the other comprising crossbred sheep. In each group, five ewes were challenged with the bacterial strain and one was used as control. All sheep were monitored for 60 days, during which blood samples were collected for serological diagnosis and urine and vaginal fluid samples for molecular and microbiological analyses. Finally, as ewes were submitted to euthanasia and necropsy, some tissues of interest were collected for microbiological, molecular, and histopathological diagnoses. The groups were compared regarding the number of positive reactions according to diagnostic tests. All sheep in each group presented antibodies to Leptospira in all serological analyses, except animals of the control group. However the Santa Inês sheep presented higher concentration and duration of the titers, and their positive reactions were detected earlier than those in crossbred sheep. The antibody titers in group A (median 200, geometric mean 317.48) were significantly different from the group B (median 800, geometric mean 918.96) at D60 post-infection (P = 0,032). The Santa Inês sheep presented a higher number of positive reactions than did the crossbred sheep in the molecular diagnostic tests. According to the molecular diagnosis, the Santa Inês sheep presented more reactions (urine and vaginal fluid) compared to crossbred ewes, but there was no predominance in the detection of leptospiral DNA when comparing urine and vaginal fluid results, nor even between the number of positive kidneys and uterus. The Santa Inês sheep presented a higher number of positive bacteriological cultures. No sheep in either group presented alterations in anatomopathological and histopathological findings. Pure-bred sheep may be more susceptible than crossbred sheep to infection by Leptospira sp. Our findings emphasize the importance of the genital tract as a site of extraurinary infection and indicate the possibility of venereal transmission in the species.

DETECTION OF ANTIBODIES AGAINST PARAMYXOVIRUSES IN TORTOISES

Sera from a total of 202 tortoises from six countries and nine species were tested for antibodies against four different reptilian paramyxoviruses (ferlaviruses, ferlaVs) by hemagglutination inhibition (HI) test. The viruses used were a tortoise PMV (tPMV) and three squamatid PMV isolates, each belonging to a different subgroup of ferlaV within the genus Ferlavirus. HI tests revealed that antibodies against ferlaVs occurred regularly in the tested samples (5.5%). One and a half percent of the tested samples have measurable antibody titers against the group A isolate, 3% had antibodies against the group B isolate, and 1% had antibodies against the group C isolate. The significantly highest number of positive reactions was detected against the tortoise isolate (5%). Most of the animals that tested positive for one of the snake isolates also tested positive in HI assays with the tortoise isolate. Of the samples from different origins, the sera from Great Britain showed the highest percentage of positive tested animals (10.3%, n = 39), followed by those from Spain (10%, n = 10), while none of the samples from Madagascar or Italy scored positive. Since in most cases animals from one country came from the same collection, this does not represent the real prevalence of ferlaV in tortoises in these countries but rather indicates that ferlaVs occur in a number of different countries and tortoise species.

Establishing aluminium contact allergy

Traditionally, contact allergy to aluminium has been established by patch testing with aluminium chloride hexahydrate in petrolatum at 2.0% and an empty Finn Chamber®. The aim of this study was to investigate different aluminium test preparations regarding an optimal compound and an optimal test concentration. Six different aluminium compounds and an empty Finn Chamber® were used to patch test 21 patients with aluminium contact allergy. Aluminium chloride hexahydrate in saline was used for intracutaneous injection of 19 patients. One test preparation, aluminium lactate 2.4%, was found to show significantly more positive patch test reactions than aluminium chloride hexahydrate 2.0% (p = 0.03). Aluminium chloride hexahydrate at 10.0% pet. gave the highest number of positive reactions to aluminium [14/21 (67%)]. No positive reactions were noted to an empty Finn Chamber®, and 3 of 19 (16%) patients reacted positively to the intradermal test. The results of this study indicate that patch testing with aluminium chloride hexahydrate 2.0%, with an empty Finn Chamber® and the intradermal test with the salt and doses used are insufficient methods to detect contact allergy to aluminium. Aluminium chloride hexahydrate at 10.0% gave the highest number of positive reactions to aluminium.

Allergen-specific IgE in Icelandic horses with insect bite hypersensitivity and healthy controls, assessed by FcɛR1α-based serology

Insect bite hypersensitivity (IBH) and atopy can both be causes of pruritus in horses and are associated with allergen-specific IgE to biting insects and environmental allergens respectively. Information with respect to differences in IgE levels in diseased and healthy animals is crucial in enabling an understanding of the clinical relevance of results of allergen-specific IgE tests. The aim of this study was (i) to evaluate and compare levels of allergen-specific IgE, using an ELISA method, in Icelandic horses, with and without IBH, from Iceland and Sweden respectively; (ii) to investigate patterns of allergen-specific IgE to insects, pollens, moulds and mites in those groups of horses; and (iii) to investigate the clinical significance of employing two different cut-off levels for the ELISA. The study compromised a total number of 99 horses from Iceland and Sweden, with and without IBH, divided in 5 groups. Sera from the horses were analysed blindly with the use of Allercept™, a non-competitive, solid-phase ELISA-test, designed to detect the presence of allergen-specific IgE in sera using the recombinant alpha chain of the high-affinity IgE receptor (FcɛR1α). The distribution of the ELISA values was shown for each insect, mould, mite and pollen allergen, in the different groups using 10th, 50th and 90th percentiles. The use of two cut-off levels, 150 EA and 300 EA, did not eliminate the false positives. Horses with IBH had a higher number of positive reactions, counting all the 29 allergens, than healthy controls and this was borderline significant ( P = 0.053). In this study it was shown that serological testing with an ELISA that uses the high-affinity IgE receptor (FcɛR1α) is presently not suitable as a tool for establishing a diagnosis of IBH or equine atopy. The importance of establishing a correct cut-off level for the ELISA for the different allergens is emphasised.

Sensitivity patterns to house dust mites and forage mites in atopic dogs: 150 cases.

This study investigated intradermal test reactions to extracts of six species of mites in 150 dogs with atopic dermatitis. At least one positive reaction was seen in 120 animals (80%). Dermatophagoides farinae attracted the highest number of positive reactions (108 dogs, 90% of dogs and 72% of atopic dogs showing positive reactions). Positive reactions to other mites were not uncommon, with many dogs testing positive for Dermatophagoides pteronyssinus (32% of dogs tested), Acarus siro (35%), Tyrophagus putrescentiae (30%), Glycyphagus domesticus (27%) and Lepidoglyphus destructor (23%). Sensitivity to D. farinae alone occurred commonly (57% of cases), but multiple sensitivities were seen frequently with the other mites. Cases of sensitivity to only one mite were also seen: D. pteronyssinus (five cases), T. putrescentiae (one case) and G. domesticus (one case). Further studies are needed to appreciate more clearly the precise role played by the different species of mite in canine atopic dermatitis.

Associated Positive Patch Test Reactions to Standard Contact Allergens

Background: Patch testing with a standard allergen series often yields positive reactions to more than 1 allergen in a patient. Objective: To identify all significantly associated pairs of positive reactions and to assess their relation to the strength of the reactions and to the irritative potential of the allergens. Methods: Based on the filed data of 57,822 patients, associations between positive reactions to 2 different allergens were quantified with odds ratios. Statistical methods included Fisher's exact test, the Bonferroni adjustment to account for the effect of multiple testing, and the Spearman rank correlation. Results: Out of the 32,779 patients with complete readings of 24 standard allergens, 7,501 had shown more than 1 positive reaction. Statistically significant associations were detected for 166 out of the 276 possible different combinations of 2 distinct positive reactions, including combinations that had not been identified before. Patients with a strong reaction or a positive reaction to an allergen with a high irritative potential tended to have additional positive reactions to further allergens more often than others, but the number of significant associations was not dependent on these parameters. Conclusion: There are more significant associations that have to be taken into account for patch testing than has been known so far. Although irritation can favor a higher number of positive reactions, significant associations of positive reactions to distinct allergens are probably caused by other mechanisms that require further analyses.

Atopy patch testing--a diagnostic tool?

Atopy patch testing--a diagnostic tool?

Canine atopic disease: the prevalence of positive intradermal skin tests at two sites in the north and south of Great Britain

Results of intradermal skin test responses to the same panel of 53 allergens were compared in 118 dogs with atopic disease presented at two geographical centres, Edinburgh (87 cases) and London (31 cases). The allergens most commonly positive at both centres were human dander and Dermatophagoides farinae, but positive tests to all of the allergens used occurred in at least one case. The mean number of allergens to which positive tests resulted in atopic dogs was 5.126 (Edinburgh) and 5.129 (London). The majority of animals were sensitive to allergens from more than one group. A significantly higher number of positive reactors to house dust allergen was observed at London than at Edinburgh ( P<0.05), while a significantly higher number of positive reactions to grass pollens was detected at Edinburgh than in London ( P<0.05). Sensitivity to Dermatophagoides pteronyssinus, in the absence of sensitivity to D. farinae, was uncommon and therefore both of these mite allergens should be incorporated in intradermal skin testing panels in Great Britain.

Study on Cross-Reactivity to the Para Group

In 80 patients, positive to at least one hapten of the para group (para-phenylenediamine, diaminodiphenylmethane, benzocaine, PPD mix), patch tests were carried out with freshly prepared solutions of para-phenylenediamine (PPD) and of 3 selected aromatic compounds related structurally to PPD (para-aminophenol, ortho-aminophenol, hydroquinone). The number of positive reactions correlated with the rate of decomposition of the substances as evaluated by high-pressure liquid chromatography. PPD, which was almost decomposed after 24 h, gave the highest number of positive reactions, followed by ortho-aminophenol and by para-aminophenol, while hydroquinone, which was oxidized to the extent of 35%, did not give any reactions. To evaluate if a different rate of oxidation can modify the patch test response, in the same patients and in 10 normal volunteers, tests were carried out with PPD solutions containing the oxidizing agent silver oxide (0.1%). By this procedure a significant increase in the number of positive responses was observed. The results suggest that the rate of decomposition and therefore the amount of quinone(s) generated, might be the key to eliciting patch test responses to oxidizable aromatic haptens.

Contact dermatitis in patients with leg ulcers. The prevalence of late positive reactions and evidence against systemic ampliative allergy.

100 patients with leg ulcers were patch tested against a standard battery of allergens. The readings were carried out daily from the 2nd to the 7th days. 55 patients showed positive reactions to one or more allergens. 32% of positive reactions developed for the first time after 48 h and 11% after 72 h. No single day or combination of two days gave 100% positive results. A single reading on the 4th day gave the highest number of positive reactions at 92%. The prevalence of positive patch tests was significantly higher in patients with surrounding eczema, and in patients with positive patch tests the ulcer duration was significantly longer than in those with negative patch tests. The total number of positive results in individuals increased linearly with the duration of the ulcer. Of allergens to which the ulcer was exposed, the occurrence of multiple sensitivity was significantly greater than predicted from the prevalence of individual sensitivities. However, there was no association between medicaments and metal sensitivity. This, together with the absence of an exponential rise in the number of allergens with the duration of ulcer, does not support the theory of systemic ampliative allergy.

Patch tests with fragrance materials and preservatives.

179 patients suspected of cosmetic allergy were patch tested with a series of 16 fragrance materials and 9 preservatives. In 67 patients (37.4%), 1 or more of these substances gave positive reactions. In the group of fragrance materials, the largest numbers of positive patch test reactions were seen to isoeugenol, oak moss, geraniol, alpha-amylcinnamic alcohol, and a mixture of alpha-amylcinnamic aldehyde and alpha-hexylcinnamic aldehyde. The fragrance mix in the ICDRG standard series detected nearly 80% of cases of contact allergy to fragrance materials other than its constituents. In the group of preservatives, Kathon CG and quaternium-15 scored the highest number of positive reactions. It is argued that the commonly used patch test concentrations of 2% for oak moss and geraniol may be too low to detect all cases of sensitization.

Effect of prolonged administration of small doses of LH-RH and LH-RH analogue [D-Ser (But) 6] Des Gly-NH 210 ethylamide on the release of LH and induction of ovulation in mid-anoestrous ewes

A natural process of LH release and induction of ovulation in anoestrous ewes was simulated by prolonged administration of small doses of LH-RH and its analogue [D-Ser(But) 6] Des Gly-NH 2 10 ethylamide. In the first series of experiments on 40 Merino ewes infusions of LH-RH were made into the maxillaris interna artery for 6 consecutive days for 6 h each day. Total doses of 24.0, 26.0, 28.0 and 32.0 μg per animal of varying and progressively increasing daily quantities of the hormone were administered in groups I, II, III and IV, respectively. In group V the animals were infused with a total dose of 28.0 μg LH-RH and injected additionally i.m. with 3.0 μg 17β-oestradiol on days 4 and 5 of the infusion of LH-RH. Ovulation did not occur earlier than days 4, 5 and 6 after the beginning of infusions. The highest number of positive reactions occurred in group IV ( 8 10 ) and in group V ( 7 8 animals). The pattern of LH peaks in general was correlated with the time of ovulations. The LH concentrations of the preovulatory peaks in experimental ewes were mostly lower than those in naturally ovulating animals. The corpora lutea were functional during the first 7 days after ovulation. In the second series of experiments on 26 Merino ewes the LH-RH analogue [D-Ser -(But) 6] Des Gly-NH 2 10 ethylamide was injected i.m. or i.a. for 6 consecutive days. Total doses of 15.5, 9.5 and 7.5 μg of the analogue per animal, administered at varying and progressively increasing daily doses in respective groups, induced several surges of LH in the same individuals for 2 or even 3 consecutive days. Corpora lutea and degenerating follicles in the form of cysts were found in the ovaries of animals of these groups. Very small daily doses ranging from 0.1 μg administered during the first 3 days, to 1.5 μg on day 5 of the treatment, released one surge of LH on day 5 of the treatment in all individuals with peaks ranging from 30.0 to 58.0 ng/ml and induction of ovulation with almost normal luteal function. On the basis of these experiments it is suggested that the evaluation of the effect of active substance (LH-RH or its analogue), its suitability and application of rightly chosen doses to induce the full physiological process of ovulation should be based not only on the release of LH and luteal function but also on tests of the ability of the released ovum to undergo fertilization and its further development.